tcp.c revision 73852e8151b7d7a529fbe019ab6d2d0c02d8f3f2
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#include <linux/kernel.h> 249#include <linux/module.h> 250#include <linux/types.h> 251#include <linux/fcntl.h> 252#include <linux/poll.h> 253#include <linux/init.h> 254#include <linux/fs.h> 255#include <linux/skbuff.h> 256#include <linux/scatterlist.h> 257#include <linux/splice.h> 258#include <linux/net.h> 259#include <linux/socket.h> 260#include <linux/random.h> 261#include <linux/bootmem.h> 262#include <linux/highmem.h> 263#include <linux/swap.h> 264#include <linux/cache.h> 265#include <linux/err.h> 266#include <linux/crypto.h> 267#include <linux/time.h> 268 269#include <net/icmp.h> 270#include <net/tcp.h> 271#include <net/xfrm.h> 272#include <net/ip.h> 273#include <net/netdma.h> 274#include <net/sock.h> 275 276#include <asm/uaccess.h> 277#include <asm/ioctls.h> 278 279int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; 280 281struct percpu_counter tcp_orphan_count; 282EXPORT_SYMBOL_GPL(tcp_orphan_count); 283 284int sysctl_tcp_mem[3] __read_mostly; 285int sysctl_tcp_wmem[3] __read_mostly; 286int sysctl_tcp_rmem[3] __read_mostly; 287 288EXPORT_SYMBOL(sysctl_tcp_mem); 289EXPORT_SYMBOL(sysctl_tcp_rmem); 290EXPORT_SYMBOL(sysctl_tcp_wmem); 291 292atomic_t tcp_memory_allocated; /* Current allocated memory. */ 293EXPORT_SYMBOL(tcp_memory_allocated); 294 295/* 296 * Current number of TCP sockets. 297 */ 298struct percpu_counter tcp_sockets_allocated; 299EXPORT_SYMBOL(tcp_sockets_allocated); 300 301/* 302 * TCP splice context 303 */ 304struct tcp_splice_state { 305 struct pipe_inode_info *pipe; 306 size_t len; 307 unsigned int flags; 308}; 309 310/* 311 * Pressure flag: try to collapse. 312 * Technical note: it is used by multiple contexts non atomically. 313 * All the __sk_mem_schedule() is of this nature: accounting 314 * is strict, actions are advisory and have some latency. 315 */ 316int tcp_memory_pressure __read_mostly; 317 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} 327 328EXPORT_SYMBOL(tcp_enter_memory_pressure); 329 330/* Convert seconds to retransmits based on initial and max timeout */ 331static u8 secs_to_retrans(int seconds, int timeout, int rto_max) 332{ 333 u8 res = 0; 334 335 if (seconds > 0) { 336 int period = timeout; 337 338 res = 1; 339 while (seconds > period && res < 255) { 340 res++; 341 timeout <<= 1; 342 if (timeout > rto_max) 343 timeout = rto_max; 344 period += timeout; 345 } 346 } 347 return res; 348} 349 350/* Convert retransmits to seconds based on initial and max timeout */ 351static int retrans_to_secs(u8 retrans, int timeout, int rto_max) 352{ 353 int period = 0; 354 355 if (retrans > 0) { 356 period = timeout; 357 while (--retrans) { 358 timeout <<= 1; 359 if (timeout > rto_max) 360 timeout = rto_max; 361 period += timeout; 362 } 363 } 364 return period; 365} 366 367/* 368 * Wait for a TCP event. 369 * 370 * Note that we don't need to lock the socket, as the upper poll layers 371 * take care of normal races (between the test and the event) and we don't 372 * go look at any of the socket buffers directly. 373 */ 374unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 375{ 376 unsigned int mask; 377 struct sock *sk = sock->sk; 378 struct tcp_sock *tp = tcp_sk(sk); 379 380 sock_poll_wait(file, sk->sk_sleep, wait); 381 if (sk->sk_state == TCP_LISTEN) 382 return inet_csk_listen_poll(sk); 383 384 /* Socket is not locked. We are protected from async events 385 * by poll logic and correct handling of state changes 386 * made by other threads is impossible in any case. 387 */ 388 389 mask = 0; 390 if (sk->sk_err) 391 mask = POLLERR; 392 393 /* 394 * POLLHUP is certainly not done right. But poll() doesn't 395 * have a notion of HUP in just one direction, and for a 396 * socket the read side is more interesting. 397 * 398 * Some poll() documentation says that POLLHUP is incompatible 399 * with the POLLOUT/POLLWR flags, so somebody should check this 400 * all. But careful, it tends to be safer to return too many 401 * bits than too few, and you can easily break real applications 402 * if you don't tell them that something has hung up! 403 * 404 * Check-me. 405 * 406 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and 407 * our fs/select.c). It means that after we received EOF, 408 * poll always returns immediately, making impossible poll() on write() 409 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP 410 * if and only if shutdown has been made in both directions. 411 * Actually, it is interesting to look how Solaris and DUX 412 * solve this dilemma. I would prefer, if POLLHUP were maskable, 413 * then we could set it on SND_SHUTDOWN. BTW examples given 414 * in Stevens' books assume exactly this behaviour, it explains 415 * why POLLHUP is incompatible with POLLOUT. --ANK 416 * 417 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 418 * blocking on fresh not-connected or disconnected socket. --ANK 419 */ 420 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) 421 mask |= POLLHUP; 422 if (sk->sk_shutdown & RCV_SHUTDOWN) 423 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 424 425 /* Connected? */ 426 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { 427 int target = sock_rcvlowat(sk, 0, INT_MAX); 428 429 if (tp->urg_seq == tp->copied_seq && 430 !sock_flag(sk, SOCK_URGINLINE) && 431 tp->urg_data) 432 target++; 433 434 /* Potential race condition. If read of tp below will 435 * escape above sk->sk_state, we can be illegally awaken 436 * in SYN_* states. */ 437 if (tp->rcv_nxt - tp->copied_seq >= target) 438 mask |= POLLIN | POLLRDNORM; 439 440 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 441 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 442 mask |= POLLOUT | POLLWRNORM; 443 } else { /* send SIGIO later */ 444 set_bit(SOCK_ASYNC_NOSPACE, 445 &sk->sk_socket->flags); 446 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 447 448 /* Race breaker. If space is freed after 449 * wspace test but before the flags are set, 450 * IO signal will be lost. 451 */ 452 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) 453 mask |= POLLOUT | POLLWRNORM; 454 } 455 } 456 457 if (tp->urg_data & TCP_URG_VALID) 458 mask |= POLLPRI; 459 } 460 return mask; 461} 462 463int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 464{ 465 struct tcp_sock *tp = tcp_sk(sk); 466 int answ; 467 468 switch (cmd) { 469 case SIOCINQ: 470 if (sk->sk_state == TCP_LISTEN) 471 return -EINVAL; 472 473 lock_sock(sk); 474 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 475 answ = 0; 476 else if (sock_flag(sk, SOCK_URGINLINE) || 477 !tp->urg_data || 478 before(tp->urg_seq, tp->copied_seq) || 479 !before(tp->urg_seq, tp->rcv_nxt)) { 480 struct sk_buff *skb; 481 482 answ = tp->rcv_nxt - tp->copied_seq; 483 484 /* Subtract 1, if FIN is in queue. */ 485 skb = skb_peek_tail(&sk->sk_receive_queue); 486 if (answ && skb) 487 answ -= tcp_hdr(skb)->fin; 488 } else 489 answ = tp->urg_seq - tp->copied_seq; 490 release_sock(sk); 491 break; 492 case SIOCATMARK: 493 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 494 break; 495 case SIOCOUTQ: 496 if (sk->sk_state == TCP_LISTEN) 497 return -EINVAL; 498 499 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 500 answ = 0; 501 else 502 answ = tp->write_seq - tp->snd_una; 503 break; 504 default: 505 return -ENOIOCTLCMD; 506 } 507 508 return put_user(answ, (int __user *)arg); 509} 510 511static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 512{ 513 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH; 514 tp->pushed_seq = tp->write_seq; 515} 516 517static inline int forced_push(struct tcp_sock *tp) 518{ 519 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 520} 521 522static inline void skb_entail(struct sock *sk, struct sk_buff *skb) 523{ 524 struct tcp_sock *tp = tcp_sk(sk); 525 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 526 527 skb->csum = 0; 528 tcb->seq = tcb->end_seq = tp->write_seq; 529 tcb->flags = TCPCB_FLAG_ACK; 530 tcb->sacked = 0; 531 skb_header_release(skb); 532 tcp_add_write_queue_tail(sk, skb); 533 sk->sk_wmem_queued += skb->truesize; 534 sk_mem_charge(sk, skb->truesize); 535 if (tp->nonagle & TCP_NAGLE_PUSH) 536 tp->nonagle &= ~TCP_NAGLE_PUSH; 537} 538 539static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) 540{ 541 if (flags & MSG_OOB) 542 tp->snd_up = tp->write_seq; 543} 544 545static inline void tcp_push(struct sock *sk, int flags, int mss_now, 546 int nonagle) 547{ 548 if (tcp_send_head(sk)) { 549 struct tcp_sock *tp = tcp_sk(sk); 550 551 if (!(flags & MSG_MORE) || forced_push(tp)) 552 tcp_mark_push(tp, tcp_write_queue_tail(sk)); 553 554 tcp_mark_urg(tp, flags); 555 __tcp_push_pending_frames(sk, mss_now, 556 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); 557 } 558} 559 560static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 561 unsigned int offset, size_t len) 562{ 563 struct tcp_splice_state *tss = rd_desc->arg.data; 564 int ret; 565 566 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len), 567 tss->flags); 568 if (ret > 0) 569 rd_desc->count -= ret; 570 return ret; 571} 572 573static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 574{ 575 /* Store TCP splice context information in read_descriptor_t. */ 576 read_descriptor_t rd_desc = { 577 .arg.data = tss, 578 .count = tss->len, 579 }; 580 581 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 582} 583 584/** 585 * tcp_splice_read - splice data from TCP socket to a pipe 586 * @sock: socket to splice from 587 * @ppos: position (not valid) 588 * @pipe: pipe to splice to 589 * @len: number of bytes to splice 590 * @flags: splice modifier flags 591 * 592 * Description: 593 * Will read pages from given socket and fill them into a pipe. 594 * 595 **/ 596ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 597 struct pipe_inode_info *pipe, size_t len, 598 unsigned int flags) 599{ 600 struct sock *sk = sock->sk; 601 struct tcp_splice_state tss = { 602 .pipe = pipe, 603 .len = len, 604 .flags = flags, 605 }; 606 long timeo; 607 ssize_t spliced; 608 int ret; 609 610 /* 611 * We can't seek on a socket input 612 */ 613 if (unlikely(*ppos)) 614 return -ESPIPE; 615 616 ret = spliced = 0; 617 618 lock_sock(sk); 619 620 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); 621 while (tss.len) { 622 ret = __tcp_splice_read(sk, &tss); 623 if (ret < 0) 624 break; 625 else if (!ret) { 626 if (spliced) 627 break; 628 if (sock_flag(sk, SOCK_DONE)) 629 break; 630 if (sk->sk_err) { 631 ret = sock_error(sk); 632 break; 633 } 634 if (sk->sk_shutdown & RCV_SHUTDOWN) 635 break; 636 if (sk->sk_state == TCP_CLOSE) { 637 /* 638 * This occurs when user tries to read 639 * from never connected socket. 640 */ 641 if (!sock_flag(sk, SOCK_DONE)) 642 ret = -ENOTCONN; 643 break; 644 } 645 if (!timeo) { 646 ret = -EAGAIN; 647 break; 648 } 649 sk_wait_data(sk, &timeo); 650 if (signal_pending(current)) { 651 ret = sock_intr_errno(timeo); 652 break; 653 } 654 continue; 655 } 656 tss.len -= ret; 657 spliced += ret; 658 659 if (!timeo) 660 break; 661 release_sock(sk); 662 lock_sock(sk); 663 664 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 665 (sk->sk_shutdown & RCV_SHUTDOWN) || 666 signal_pending(current)) 667 break; 668 } 669 670 release_sock(sk); 671 672 if (spliced) 673 return spliced; 674 675 return ret; 676} 677 678struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) 679{ 680 struct sk_buff *skb; 681 682 /* The TCP header must be at least 32-bit aligned. */ 683 size = ALIGN(size, 4); 684 685 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 686 if (skb) { 687 if (sk_wmem_schedule(sk, skb->truesize)) { 688 /* 689 * Make sure that we have exactly size bytes 690 * available to the caller, no more, no less. 691 */ 692 skb_reserve(skb, skb_tailroom(skb) - size); 693 return skb; 694 } 695 __kfree_skb(skb); 696 } else { 697 sk->sk_prot->enter_memory_pressure(sk); 698 sk_stream_moderate_sndbuf(sk); 699 } 700 return NULL; 701} 702 703static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, 704 int large_allowed) 705{ 706 struct tcp_sock *tp = tcp_sk(sk); 707 u32 xmit_size_goal, old_size_goal; 708 709 xmit_size_goal = mss_now; 710 711 if (large_allowed && sk_can_gso(sk)) { 712 xmit_size_goal = ((sk->sk_gso_max_size - 1) - 713 inet_csk(sk)->icsk_af_ops->net_header_len - 714 inet_csk(sk)->icsk_ext_hdr_len - 715 tp->tcp_header_len); 716 717 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal); 718 719 /* We try hard to avoid divides here */ 720 old_size_goal = tp->xmit_size_goal_segs * mss_now; 721 722 if (likely(old_size_goal <= xmit_size_goal && 723 old_size_goal + mss_now > xmit_size_goal)) { 724 xmit_size_goal = old_size_goal; 725 } else { 726 tp->xmit_size_goal_segs = xmit_size_goal / mss_now; 727 xmit_size_goal = tp->xmit_size_goal_segs * mss_now; 728 } 729 } 730 731 return max(xmit_size_goal, mss_now); 732} 733 734static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) 735{ 736 int mss_now; 737 738 mss_now = tcp_current_mss(sk); 739 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); 740 741 return mss_now; 742} 743 744static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, 745 size_t psize, int flags) 746{ 747 struct tcp_sock *tp = tcp_sk(sk); 748 int mss_now, size_goal; 749 int err; 750 ssize_t copied; 751 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 752 753 /* Wait for a connection to finish. */ 754 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 755 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 756 goto out_err; 757 758 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 759 760 mss_now = tcp_send_mss(sk, &size_goal, flags); 761 copied = 0; 762 763 err = -EPIPE; 764 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 765 goto out_err; 766 767 while (psize > 0) { 768 struct sk_buff *skb = tcp_write_queue_tail(sk); 769 struct page *page = pages[poffset / PAGE_SIZE]; 770 int copy, i, can_coalesce; 771 int offset = poffset % PAGE_SIZE; 772 int size = min_t(size_t, psize, PAGE_SIZE - offset); 773 774 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { 775new_segment: 776 if (!sk_stream_memory_free(sk)) 777 goto wait_for_sndbuf; 778 779 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); 780 if (!skb) 781 goto wait_for_memory; 782 783 skb_entail(sk, skb); 784 copy = size_goal; 785 } 786 787 if (copy > size) 788 copy = size; 789 790 i = skb_shinfo(skb)->nr_frags; 791 can_coalesce = skb_can_coalesce(skb, i, page, offset); 792 if (!can_coalesce && i >= MAX_SKB_FRAGS) { 793 tcp_mark_push(tp, skb); 794 goto new_segment; 795 } 796 if (!sk_wmem_schedule(sk, copy)) 797 goto wait_for_memory; 798 799 if (can_coalesce) { 800 skb_shinfo(skb)->frags[i - 1].size += copy; 801 } else { 802 get_page(page); 803 skb_fill_page_desc(skb, i, page, offset, copy); 804 } 805 806 skb->len += copy; 807 skb->data_len += copy; 808 skb->truesize += copy; 809 sk->sk_wmem_queued += copy; 810 sk_mem_charge(sk, copy); 811 skb->ip_summed = CHECKSUM_PARTIAL; 812 tp->write_seq += copy; 813 TCP_SKB_CB(skb)->end_seq += copy; 814 skb_shinfo(skb)->gso_segs = 0; 815 816 if (!copied) 817 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 818 819 copied += copy; 820 poffset += copy; 821 if (!(psize -= copy)) 822 goto out; 823 824 if (skb->len < size_goal || (flags & MSG_OOB)) 825 continue; 826 827 if (forced_push(tp)) { 828 tcp_mark_push(tp, skb); 829 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 830 } else if (skb == tcp_send_head(sk)) 831 tcp_push_one(sk, mss_now); 832 continue; 833 834wait_for_sndbuf: 835 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 836wait_for_memory: 837 if (copied) 838 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 839 840 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 841 goto do_error; 842 843 mss_now = tcp_send_mss(sk, &size_goal, flags); 844 } 845 846out: 847 if (copied) 848 tcp_push(sk, flags, mss_now, tp->nonagle); 849 return copied; 850 851do_error: 852 if (copied) 853 goto out; 854out_err: 855 return sk_stream_error(sk, flags, err); 856} 857 858ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, 859 size_t size, int flags) 860{ 861 ssize_t res; 862 struct sock *sk = sock->sk; 863 864 if (!(sk->sk_route_caps & NETIF_F_SG) || 865 !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) 866 return sock_no_sendpage(sock, page, offset, size, flags); 867 868 lock_sock(sk); 869 TCP_CHECK_TIMER(sk); 870 res = do_tcp_sendpages(sk, &page, offset, size, flags); 871 TCP_CHECK_TIMER(sk); 872 release_sock(sk); 873 return res; 874} 875 876#define TCP_PAGE(sk) (sk->sk_sndmsg_page) 877#define TCP_OFF(sk) (sk->sk_sndmsg_off) 878 879static inline int select_size(struct sock *sk, int sg) 880{ 881 struct tcp_sock *tp = tcp_sk(sk); 882 int tmp = tp->mss_cache; 883 884 if (sg) { 885 if (sk_can_gso(sk)) 886 tmp = 0; 887 else { 888 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); 889 890 if (tmp >= pgbreak && 891 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) 892 tmp = pgbreak; 893 } 894 } 895 896 return tmp; 897} 898 899int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, 900 size_t size) 901{ 902 struct sock *sk = sock->sk; 903 struct iovec *iov; 904 struct tcp_sock *tp = tcp_sk(sk); 905 struct sk_buff *skb; 906 int iovlen, flags; 907 int mss_now, size_goal; 908 int sg, err, copied; 909 long timeo; 910 911 lock_sock(sk); 912 TCP_CHECK_TIMER(sk); 913 914 flags = msg->msg_flags; 915 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 916 917 /* Wait for a connection to finish. */ 918 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 919 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 920 goto out_err; 921 922 /* This should be in poll */ 923 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 924 925 mss_now = tcp_send_mss(sk, &size_goal, flags); 926 927 /* Ok commence sending. */ 928 iovlen = msg->msg_iovlen; 929 iov = msg->msg_iov; 930 copied = 0; 931 932 err = -EPIPE; 933 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 934 goto out_err; 935 936 sg = sk->sk_route_caps & NETIF_F_SG; 937 938 while (--iovlen >= 0) { 939 int seglen = iov->iov_len; 940 unsigned char __user *from = iov->iov_base; 941 942 iov++; 943 944 while (seglen > 0) { 945 int copy = 0; 946 int max = size_goal; 947 948 skb = tcp_write_queue_tail(sk); 949 if (tcp_send_head(sk)) { 950 if (skb->ip_summed == CHECKSUM_NONE) 951 max = mss_now; 952 copy = max - skb->len; 953 } 954 955 if (copy <= 0) { 956new_segment: 957 /* Allocate new segment. If the interface is SG, 958 * allocate skb fitting to single page. 959 */ 960 if (!sk_stream_memory_free(sk)) 961 goto wait_for_sndbuf; 962 963 skb = sk_stream_alloc_skb(sk, 964 select_size(sk, sg), 965 sk->sk_allocation); 966 if (!skb) 967 goto wait_for_memory; 968 969 /* 970 * Check whether we can use HW checksum. 971 */ 972 if (sk->sk_route_caps & NETIF_F_ALL_CSUM) 973 skb->ip_summed = CHECKSUM_PARTIAL; 974 975 skb_entail(sk, skb); 976 copy = size_goal; 977 max = size_goal; 978 } 979 980 /* Try to append data to the end of skb. */ 981 if (copy > seglen) 982 copy = seglen; 983 984 /* Where to copy to? */ 985 if (skb_tailroom(skb) > 0) { 986 /* We have some space in skb head. Superb! */ 987 if (copy > skb_tailroom(skb)) 988 copy = skb_tailroom(skb); 989 if ((err = skb_add_data(skb, from, copy)) != 0) 990 goto do_fault; 991 } else { 992 int merge = 0; 993 int i = skb_shinfo(skb)->nr_frags; 994 struct page *page = TCP_PAGE(sk); 995 int off = TCP_OFF(sk); 996 997 if (skb_can_coalesce(skb, i, page, off) && 998 off != PAGE_SIZE) { 999 /* We can extend the last page 1000 * fragment. */ 1001 merge = 1; 1002 } else if (i == MAX_SKB_FRAGS || !sg) { 1003 /* Need to add new fragment and cannot 1004 * do this because interface is non-SG, 1005 * or because all the page slots are 1006 * busy. */ 1007 tcp_mark_push(tp, skb); 1008 goto new_segment; 1009 } else if (page) { 1010 if (off == PAGE_SIZE) { 1011 put_page(page); 1012 TCP_PAGE(sk) = page = NULL; 1013 off = 0; 1014 } 1015 } else 1016 off = 0; 1017 1018 if (copy > PAGE_SIZE - off) 1019 copy = PAGE_SIZE - off; 1020 1021 if (!sk_wmem_schedule(sk, copy)) 1022 goto wait_for_memory; 1023 1024 if (!page) { 1025 /* Allocate new cache page. */ 1026 if (!(page = sk_stream_alloc_page(sk))) 1027 goto wait_for_memory; 1028 } 1029 1030 /* Time to copy data. We are close to 1031 * the end! */ 1032 err = skb_copy_to_page(sk, from, skb, page, 1033 off, copy); 1034 if (err) { 1035 /* If this page was new, give it to the 1036 * socket so it does not get leaked. 1037 */ 1038 if (!TCP_PAGE(sk)) { 1039 TCP_PAGE(sk) = page; 1040 TCP_OFF(sk) = 0; 1041 } 1042 goto do_error; 1043 } 1044 1045 /* Update the skb. */ 1046 if (merge) { 1047 skb_shinfo(skb)->frags[i - 1].size += 1048 copy; 1049 } else { 1050 skb_fill_page_desc(skb, i, page, off, copy); 1051 if (TCP_PAGE(sk)) { 1052 get_page(page); 1053 } else if (off + copy < PAGE_SIZE) { 1054 get_page(page); 1055 TCP_PAGE(sk) = page; 1056 } 1057 } 1058 1059 TCP_OFF(sk) = off + copy; 1060 } 1061 1062 if (!copied) 1063 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 1064 1065 tp->write_seq += copy; 1066 TCP_SKB_CB(skb)->end_seq += copy; 1067 skb_shinfo(skb)->gso_segs = 0; 1068 1069 from += copy; 1070 copied += copy; 1071 if ((seglen -= copy) == 0 && iovlen == 0) 1072 goto out; 1073 1074 if (skb->len < max || (flags & MSG_OOB)) 1075 continue; 1076 1077 if (forced_push(tp)) { 1078 tcp_mark_push(tp, skb); 1079 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1080 } else if (skb == tcp_send_head(sk)) 1081 tcp_push_one(sk, mss_now); 1082 continue; 1083 1084wait_for_sndbuf: 1085 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1086wait_for_memory: 1087 if (copied) 1088 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 1089 1090 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 1091 goto do_error; 1092 1093 mss_now = tcp_send_mss(sk, &size_goal, flags); 1094 } 1095 } 1096 1097out: 1098 if (copied) 1099 tcp_push(sk, flags, mss_now, tp->nonagle); 1100 TCP_CHECK_TIMER(sk); 1101 release_sock(sk); 1102 return copied; 1103 1104do_fault: 1105 if (!skb->len) { 1106 tcp_unlink_write_queue(skb, sk); 1107 /* It is the one place in all of TCP, except connection 1108 * reset, where we can be unlinking the send_head. 1109 */ 1110 tcp_check_send_head(sk, skb); 1111 sk_wmem_free_skb(sk, skb); 1112 } 1113 1114do_error: 1115 if (copied) 1116 goto out; 1117out_err: 1118 err = sk_stream_error(sk, flags, err); 1119 TCP_CHECK_TIMER(sk); 1120 release_sock(sk); 1121 return err; 1122} 1123 1124/* 1125 * Handle reading urgent data. BSD has very simple semantics for 1126 * this, no blocking and very strange errors 8) 1127 */ 1128 1129static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) 1130{ 1131 struct tcp_sock *tp = tcp_sk(sk); 1132 1133 /* No URG data to read. */ 1134 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1135 tp->urg_data == TCP_URG_READ) 1136 return -EINVAL; /* Yes this is right ! */ 1137 1138 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1139 return -ENOTCONN; 1140 1141 if (tp->urg_data & TCP_URG_VALID) { 1142 int err = 0; 1143 char c = tp->urg_data; 1144 1145 if (!(flags & MSG_PEEK)) 1146 tp->urg_data = TCP_URG_READ; 1147 1148 /* Read urgent data. */ 1149 msg->msg_flags |= MSG_OOB; 1150 1151 if (len > 0) { 1152 if (!(flags & MSG_TRUNC)) 1153 err = memcpy_toiovec(msg->msg_iov, &c, 1); 1154 len = 1; 1155 } else 1156 msg->msg_flags |= MSG_TRUNC; 1157 1158 return err ? -EFAULT : len; 1159 } 1160 1161 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1162 return 0; 1163 1164 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1165 * the available implementations agree in this case: 1166 * this call should never block, independent of the 1167 * blocking state of the socket. 1168 * Mike <pall@rz.uni-karlsruhe.de> 1169 */ 1170 return -EAGAIN; 1171} 1172 1173/* Clean up the receive buffer for full frames taken by the user, 1174 * then send an ACK if necessary. COPIED is the number of bytes 1175 * tcp_recvmsg has given to the user so far, it speeds up the 1176 * calculation of whether or not we must ACK for the sake of 1177 * a window update. 1178 */ 1179void tcp_cleanup_rbuf(struct sock *sk, int copied) 1180{ 1181 struct tcp_sock *tp = tcp_sk(sk); 1182 int time_to_ack = 0; 1183 1184#if TCP_DEBUG 1185 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1186 1187 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), 1188 KERN_INFO "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", 1189 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); 1190#endif 1191 1192 if (inet_csk_ack_scheduled(sk)) { 1193 const struct inet_connection_sock *icsk = inet_csk(sk); 1194 /* Delayed ACKs frequently hit locked sockets during bulk 1195 * receive. */ 1196 if (icsk->icsk_ack.blocked || 1197 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1198 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1199 /* 1200 * If this read emptied read buffer, we send ACK, if 1201 * connection is not bidirectional, user drained 1202 * receive buffer and there was a small segment 1203 * in queue. 1204 */ 1205 (copied > 0 && 1206 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1207 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1208 !icsk->icsk_ack.pingpong)) && 1209 !atomic_read(&sk->sk_rmem_alloc))) 1210 time_to_ack = 1; 1211 } 1212 1213 /* We send an ACK if we can now advertise a non-zero window 1214 * which has been raised "significantly". 1215 * 1216 * Even if window raised up to infinity, do not send window open ACK 1217 * in states, where we will not receive more. It is useless. 1218 */ 1219 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1220 __u32 rcv_window_now = tcp_receive_window(tp); 1221 1222 /* Optimize, __tcp_select_window() is not cheap. */ 1223 if (2*rcv_window_now <= tp->window_clamp) { 1224 __u32 new_window = __tcp_select_window(sk); 1225 1226 /* Send ACK now, if this read freed lots of space 1227 * in our buffer. Certainly, new_window is new window. 1228 * We can advertise it now, if it is not less than current one. 1229 * "Lots" means "at least twice" here. 1230 */ 1231 if (new_window && new_window >= 2 * rcv_window_now) 1232 time_to_ack = 1; 1233 } 1234 } 1235 if (time_to_ack) 1236 tcp_send_ack(sk); 1237} 1238 1239static void tcp_prequeue_process(struct sock *sk) 1240{ 1241 struct sk_buff *skb; 1242 struct tcp_sock *tp = tcp_sk(sk); 1243 1244 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); 1245 1246 /* RX process wants to run with disabled BHs, though it is not 1247 * necessary */ 1248 local_bh_disable(); 1249 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) 1250 sk_backlog_rcv(sk, skb); 1251 local_bh_enable(); 1252 1253 /* Clear memory counter. */ 1254 tp->ucopy.memory = 0; 1255} 1256 1257#ifdef CONFIG_NET_DMA 1258static void tcp_service_net_dma(struct sock *sk, bool wait) 1259{ 1260 dma_cookie_t done, used; 1261 dma_cookie_t last_issued; 1262 struct tcp_sock *tp = tcp_sk(sk); 1263 1264 if (!tp->ucopy.dma_chan) 1265 return; 1266 1267 last_issued = tp->ucopy.dma_cookie; 1268 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1269 1270 do { 1271 if (dma_async_memcpy_complete(tp->ucopy.dma_chan, 1272 last_issued, &done, 1273 &used) == DMA_SUCCESS) { 1274 /* Safe to free early-copied skbs now */ 1275 __skb_queue_purge(&sk->sk_async_wait_queue); 1276 break; 1277 } else { 1278 struct sk_buff *skb; 1279 while ((skb = skb_peek(&sk->sk_async_wait_queue)) && 1280 (dma_async_is_complete(skb->dma_cookie, done, 1281 used) == DMA_SUCCESS)) { 1282 __skb_dequeue(&sk->sk_async_wait_queue); 1283 kfree_skb(skb); 1284 } 1285 } 1286 } while (wait); 1287} 1288#endif 1289 1290static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1291{ 1292 struct sk_buff *skb; 1293 u32 offset; 1294 1295 skb_queue_walk(&sk->sk_receive_queue, skb) { 1296 offset = seq - TCP_SKB_CB(skb)->seq; 1297 if (tcp_hdr(skb)->syn) 1298 offset--; 1299 if (offset < skb->len || tcp_hdr(skb)->fin) { 1300 *off = offset; 1301 return skb; 1302 } 1303 } 1304 return NULL; 1305} 1306 1307/* 1308 * This routine provides an alternative to tcp_recvmsg() for routines 1309 * that would like to handle copying from skbuffs directly in 'sendfile' 1310 * fashion. 1311 * Note: 1312 * - It is assumed that the socket was locked by the caller. 1313 * - The routine does not block. 1314 * - At present, there is no support for reading OOB data 1315 * or for 'peeking' the socket using this routine 1316 * (although both would be easy to implement). 1317 */ 1318int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1319 sk_read_actor_t recv_actor) 1320{ 1321 struct sk_buff *skb; 1322 struct tcp_sock *tp = tcp_sk(sk); 1323 u32 seq = tp->copied_seq; 1324 u32 offset; 1325 int copied = 0; 1326 1327 if (sk->sk_state == TCP_LISTEN) 1328 return -ENOTCONN; 1329 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1330 if (offset < skb->len) { 1331 int used; 1332 size_t len; 1333 1334 len = skb->len - offset; 1335 /* Stop reading if we hit a patch of urgent data */ 1336 if (tp->urg_data) { 1337 u32 urg_offset = tp->urg_seq - seq; 1338 if (urg_offset < len) 1339 len = urg_offset; 1340 if (!len) 1341 break; 1342 } 1343 used = recv_actor(desc, skb, offset, len); 1344 if (used < 0) { 1345 if (!copied) 1346 copied = used; 1347 break; 1348 } else if (used <= len) { 1349 seq += used; 1350 copied += used; 1351 offset += used; 1352 } 1353 /* 1354 * If recv_actor drops the lock (e.g. TCP splice 1355 * receive) the skb pointer might be invalid when 1356 * getting here: tcp_collapse might have deleted it 1357 * while aggregating skbs from the socket queue. 1358 */ 1359 skb = tcp_recv_skb(sk, seq-1, &offset); 1360 if (!skb || (offset+1 != skb->len)) 1361 break; 1362 } 1363 if (tcp_hdr(skb)->fin) { 1364 sk_eat_skb(sk, skb, 0); 1365 ++seq; 1366 break; 1367 } 1368 sk_eat_skb(sk, skb, 0); 1369 if (!desc->count) 1370 break; 1371 } 1372 tp->copied_seq = seq; 1373 1374 tcp_rcv_space_adjust(sk); 1375 1376 /* Clean up data we have read: This will do ACK frames. */ 1377 if (copied > 0) 1378 tcp_cleanup_rbuf(sk, copied); 1379 return copied; 1380} 1381 1382/* 1383 * This routine copies from a sock struct into the user buffer. 1384 * 1385 * Technical note: in 2.3 we work on _locked_ socket, so that 1386 * tricks with *seq access order and skb->users are not required. 1387 * Probably, code can be easily improved even more. 1388 */ 1389 1390int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1391 size_t len, int nonblock, int flags, int *addr_len) 1392{ 1393 struct tcp_sock *tp = tcp_sk(sk); 1394 int copied = 0; 1395 u32 peek_seq; 1396 u32 *seq; 1397 unsigned long used; 1398 int err; 1399 int target; /* Read at least this many bytes */ 1400 long timeo; 1401 struct task_struct *user_recv = NULL; 1402 int copied_early = 0; 1403 struct sk_buff *skb; 1404 u32 urg_hole = 0; 1405 1406 lock_sock(sk); 1407 1408 TCP_CHECK_TIMER(sk); 1409 1410 err = -ENOTCONN; 1411 if (sk->sk_state == TCP_LISTEN) 1412 goto out; 1413 1414 timeo = sock_rcvtimeo(sk, nonblock); 1415 1416 /* Urgent data needs to be handled specially. */ 1417 if (flags & MSG_OOB) 1418 goto recv_urg; 1419 1420 seq = &tp->copied_seq; 1421 if (flags & MSG_PEEK) { 1422 peek_seq = tp->copied_seq; 1423 seq = &peek_seq; 1424 } 1425 1426 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1427 1428#ifdef CONFIG_NET_DMA 1429 tp->ucopy.dma_chan = NULL; 1430 preempt_disable(); 1431 skb = skb_peek_tail(&sk->sk_receive_queue); 1432 { 1433 int available = 0; 1434 1435 if (skb) 1436 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); 1437 if ((available < target) && 1438 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && 1439 !sysctl_tcp_low_latency && 1440 dma_find_channel(DMA_MEMCPY)) { 1441 preempt_enable_no_resched(); 1442 tp->ucopy.pinned_list = 1443 dma_pin_iovec_pages(msg->msg_iov, len); 1444 } else { 1445 preempt_enable_no_resched(); 1446 } 1447 } 1448#endif 1449 1450 do { 1451 u32 offset; 1452 1453 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1454 if (tp->urg_data && tp->urg_seq == *seq) { 1455 if (copied) 1456 break; 1457 if (signal_pending(current)) { 1458 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1459 break; 1460 } 1461 } 1462 1463 /* Next get a buffer. */ 1464 1465 skb_queue_walk(&sk->sk_receive_queue, skb) { 1466 /* Now that we have two receive queues this 1467 * shouldn't happen. 1468 */ 1469 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 1470 KERN_INFO "recvmsg bug: copied %X " 1471 "seq %X rcvnxt %X fl %X\n", *seq, 1472 TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 1473 flags)) 1474 break; 1475 1476 offset = *seq - TCP_SKB_CB(skb)->seq; 1477 if (tcp_hdr(skb)->syn) 1478 offset--; 1479 if (offset < skb->len) 1480 goto found_ok_skb; 1481 if (tcp_hdr(skb)->fin) 1482 goto found_fin_ok; 1483 WARN(!(flags & MSG_PEEK), KERN_INFO "recvmsg bug 2: " 1484 "copied %X seq %X rcvnxt %X fl %X\n", 1485 *seq, TCP_SKB_CB(skb)->seq, 1486 tp->rcv_nxt, flags); 1487 } 1488 1489 /* Well, if we have backlog, try to process it now yet. */ 1490 1491 if (copied >= target && !sk->sk_backlog.tail) 1492 break; 1493 1494 if (copied) { 1495 if (sk->sk_err || 1496 sk->sk_state == TCP_CLOSE || 1497 (sk->sk_shutdown & RCV_SHUTDOWN) || 1498 !timeo || 1499 signal_pending(current)) 1500 break; 1501 } else { 1502 if (sock_flag(sk, SOCK_DONE)) 1503 break; 1504 1505 if (sk->sk_err) { 1506 copied = sock_error(sk); 1507 break; 1508 } 1509 1510 if (sk->sk_shutdown & RCV_SHUTDOWN) 1511 break; 1512 1513 if (sk->sk_state == TCP_CLOSE) { 1514 if (!sock_flag(sk, SOCK_DONE)) { 1515 /* This occurs when user tries to read 1516 * from never connected socket. 1517 */ 1518 copied = -ENOTCONN; 1519 break; 1520 } 1521 break; 1522 } 1523 1524 if (!timeo) { 1525 copied = -EAGAIN; 1526 break; 1527 } 1528 1529 if (signal_pending(current)) { 1530 copied = sock_intr_errno(timeo); 1531 break; 1532 } 1533 } 1534 1535 tcp_cleanup_rbuf(sk, copied); 1536 1537 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { 1538 /* Install new reader */ 1539 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { 1540 user_recv = current; 1541 tp->ucopy.task = user_recv; 1542 tp->ucopy.iov = msg->msg_iov; 1543 } 1544 1545 tp->ucopy.len = len; 1546 1547 WARN_ON(tp->copied_seq != tp->rcv_nxt && 1548 !(flags & (MSG_PEEK | MSG_TRUNC))); 1549 1550 /* Ugly... If prequeue is not empty, we have to 1551 * process it before releasing socket, otherwise 1552 * order will be broken at second iteration. 1553 * More elegant solution is required!!! 1554 * 1555 * Look: we have the following (pseudo)queues: 1556 * 1557 * 1. packets in flight 1558 * 2. backlog 1559 * 3. prequeue 1560 * 4. receive_queue 1561 * 1562 * Each queue can be processed only if the next ones 1563 * are empty. At this point we have empty receive_queue. 1564 * But prequeue _can_ be not empty after 2nd iteration, 1565 * when we jumped to start of loop because backlog 1566 * processing added something to receive_queue. 1567 * We cannot release_sock(), because backlog contains 1568 * packets arrived _after_ prequeued ones. 1569 * 1570 * Shortly, algorithm is clear --- to process all 1571 * the queues in order. We could make it more directly, 1572 * requeueing packets from backlog to prequeue, if 1573 * is not empty. It is more elegant, but eats cycles, 1574 * unfortunately. 1575 */ 1576 if (!skb_queue_empty(&tp->ucopy.prequeue)) 1577 goto do_prequeue; 1578 1579 /* __ Set realtime policy in scheduler __ */ 1580 } 1581 1582#ifdef CONFIG_NET_DMA 1583 if (tp->ucopy.dma_chan) 1584 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1585#endif 1586 if (copied >= target) { 1587 /* Do not sleep, just process backlog. */ 1588 release_sock(sk); 1589 lock_sock(sk); 1590 } else 1591 sk_wait_data(sk, &timeo); 1592 1593#ifdef CONFIG_NET_DMA 1594 tcp_service_net_dma(sk, false); /* Don't block */ 1595 tp->ucopy.wakeup = 0; 1596#endif 1597 1598 if (user_recv) { 1599 int chunk; 1600 1601 /* __ Restore normal policy in scheduler __ */ 1602 1603 if ((chunk = len - tp->ucopy.len) != 0) { 1604 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); 1605 len -= chunk; 1606 copied += chunk; 1607 } 1608 1609 if (tp->rcv_nxt == tp->copied_seq && 1610 !skb_queue_empty(&tp->ucopy.prequeue)) { 1611do_prequeue: 1612 tcp_prequeue_process(sk); 1613 1614 if ((chunk = len - tp->ucopy.len) != 0) { 1615 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1616 len -= chunk; 1617 copied += chunk; 1618 } 1619 } 1620 } 1621 if ((flags & MSG_PEEK) && 1622 (peek_seq - copied - urg_hole != tp->copied_seq)) { 1623 if (net_ratelimit()) 1624 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n", 1625 current->comm, task_pid_nr(current)); 1626 peek_seq = tp->copied_seq; 1627 } 1628 continue; 1629 1630 found_ok_skb: 1631 /* Ok so how much can we use? */ 1632 used = skb->len - offset; 1633 if (len < used) 1634 used = len; 1635 1636 /* Do we have urgent data here? */ 1637 if (tp->urg_data) { 1638 u32 urg_offset = tp->urg_seq - *seq; 1639 if (urg_offset < used) { 1640 if (!urg_offset) { 1641 if (!sock_flag(sk, SOCK_URGINLINE)) { 1642 ++*seq; 1643 urg_hole++; 1644 offset++; 1645 used--; 1646 if (!used) 1647 goto skip_copy; 1648 } 1649 } else 1650 used = urg_offset; 1651 } 1652 } 1653 1654 if (!(flags & MSG_TRUNC)) { 1655#ifdef CONFIG_NET_DMA 1656 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1657 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); 1658 1659 if (tp->ucopy.dma_chan) { 1660 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( 1661 tp->ucopy.dma_chan, skb, offset, 1662 msg->msg_iov, used, 1663 tp->ucopy.pinned_list); 1664 1665 if (tp->ucopy.dma_cookie < 0) { 1666 1667 printk(KERN_ALERT "dma_cookie < 0\n"); 1668 1669 /* Exception. Bailout! */ 1670 if (!copied) 1671 copied = -EFAULT; 1672 break; 1673 } 1674 1675 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1676 1677 if ((offset + used) == skb->len) 1678 copied_early = 1; 1679 1680 } else 1681#endif 1682 { 1683 err = skb_copy_datagram_iovec(skb, offset, 1684 msg->msg_iov, used); 1685 if (err) { 1686 /* Exception. Bailout! */ 1687 if (!copied) 1688 copied = -EFAULT; 1689 break; 1690 } 1691 } 1692 } 1693 1694 *seq += used; 1695 copied += used; 1696 len -= used; 1697 1698 tcp_rcv_space_adjust(sk); 1699 1700skip_copy: 1701 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1702 tp->urg_data = 0; 1703 tcp_fast_path_check(sk); 1704 } 1705 if (used + offset < skb->len) 1706 continue; 1707 1708 if (tcp_hdr(skb)->fin) 1709 goto found_fin_ok; 1710 if (!(flags & MSG_PEEK)) { 1711 sk_eat_skb(sk, skb, copied_early); 1712 copied_early = 0; 1713 } 1714 continue; 1715 1716 found_fin_ok: 1717 /* Process the FIN. */ 1718 ++*seq; 1719 if (!(flags & MSG_PEEK)) { 1720 sk_eat_skb(sk, skb, copied_early); 1721 copied_early = 0; 1722 } 1723 break; 1724 } while (len > 0); 1725 1726 if (user_recv) { 1727 if (!skb_queue_empty(&tp->ucopy.prequeue)) { 1728 int chunk; 1729 1730 tp->ucopy.len = copied > 0 ? len : 0; 1731 1732 tcp_prequeue_process(sk); 1733 1734 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { 1735 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1736 len -= chunk; 1737 copied += chunk; 1738 } 1739 } 1740 1741 tp->ucopy.task = NULL; 1742 tp->ucopy.len = 0; 1743 } 1744 1745#ifdef CONFIG_NET_DMA 1746 tcp_service_net_dma(sk, true); /* Wait for queue to drain */ 1747 tp->ucopy.dma_chan = NULL; 1748 1749 if (tp->ucopy.pinned_list) { 1750 dma_unpin_iovec_pages(tp->ucopy.pinned_list); 1751 tp->ucopy.pinned_list = NULL; 1752 } 1753#endif 1754 1755 /* According to UNIX98, msg_name/msg_namelen are ignored 1756 * on connected socket. I was just happy when found this 8) --ANK 1757 */ 1758 1759 /* Clean up data we have read: This will do ACK frames. */ 1760 tcp_cleanup_rbuf(sk, copied); 1761 1762 TCP_CHECK_TIMER(sk); 1763 release_sock(sk); 1764 return copied; 1765 1766out: 1767 TCP_CHECK_TIMER(sk); 1768 release_sock(sk); 1769 return err; 1770 1771recv_urg: 1772 err = tcp_recv_urg(sk, msg, len, flags); 1773 goto out; 1774} 1775 1776void tcp_set_state(struct sock *sk, int state) 1777{ 1778 int oldstate = sk->sk_state; 1779 1780 switch (state) { 1781 case TCP_ESTABLISHED: 1782 if (oldstate != TCP_ESTABLISHED) 1783 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1784 break; 1785 1786 case TCP_CLOSE: 1787 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 1788 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 1789 1790 sk->sk_prot->unhash(sk); 1791 if (inet_csk(sk)->icsk_bind_hash && 1792 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1793 inet_put_port(sk); 1794 /* fall through */ 1795 default: 1796 if (oldstate == TCP_ESTABLISHED) 1797 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1798 } 1799 1800 /* Change state AFTER socket is unhashed to avoid closed 1801 * socket sitting in hash tables. 1802 */ 1803 sk->sk_state = state; 1804 1805#ifdef STATE_TRACE 1806 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); 1807#endif 1808} 1809EXPORT_SYMBOL_GPL(tcp_set_state); 1810 1811/* 1812 * State processing on a close. This implements the state shift for 1813 * sending our FIN frame. Note that we only send a FIN for some 1814 * states. A shutdown() may have already sent the FIN, or we may be 1815 * closed. 1816 */ 1817 1818static const unsigned char new_state[16] = { 1819 /* current state: new state: action: */ 1820 /* (Invalid) */ TCP_CLOSE, 1821 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1822 /* TCP_SYN_SENT */ TCP_CLOSE, 1823 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1824 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, 1825 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, 1826 /* TCP_TIME_WAIT */ TCP_CLOSE, 1827 /* TCP_CLOSE */ TCP_CLOSE, 1828 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, 1829 /* TCP_LAST_ACK */ TCP_LAST_ACK, 1830 /* TCP_LISTEN */ TCP_CLOSE, 1831 /* TCP_CLOSING */ TCP_CLOSING, 1832}; 1833 1834static int tcp_close_state(struct sock *sk) 1835{ 1836 int next = (int)new_state[sk->sk_state]; 1837 int ns = next & TCP_STATE_MASK; 1838 1839 tcp_set_state(sk, ns); 1840 1841 return next & TCP_ACTION_FIN; 1842} 1843 1844/* 1845 * Shutdown the sending side of a connection. Much like close except 1846 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 1847 */ 1848 1849void tcp_shutdown(struct sock *sk, int how) 1850{ 1851 /* We need to grab some memory, and put together a FIN, 1852 * and then put it into the queue to be sent. 1853 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 1854 */ 1855 if (!(how & SEND_SHUTDOWN)) 1856 return; 1857 1858 /* If we've already sent a FIN, or it's a closed state, skip this. */ 1859 if ((1 << sk->sk_state) & 1860 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 1861 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 1862 /* Clear out any half completed packets. FIN if needed. */ 1863 if (tcp_close_state(sk)) 1864 tcp_send_fin(sk); 1865 } 1866} 1867 1868void tcp_close(struct sock *sk, long timeout) 1869{ 1870 struct sk_buff *skb; 1871 int data_was_unread = 0; 1872 int state; 1873 1874 lock_sock(sk); 1875 sk->sk_shutdown = SHUTDOWN_MASK; 1876 1877 if (sk->sk_state == TCP_LISTEN) { 1878 tcp_set_state(sk, TCP_CLOSE); 1879 1880 /* Special case. */ 1881 inet_csk_listen_stop(sk); 1882 1883 goto adjudge_to_death; 1884 } 1885 1886 /* We need to flush the recv. buffs. We do this only on the 1887 * descriptor close, not protocol-sourced closes, because the 1888 * reader process may not have drained the data yet! 1889 */ 1890 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1891 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - 1892 tcp_hdr(skb)->fin; 1893 data_was_unread += len; 1894 __kfree_skb(skb); 1895 } 1896 1897 sk_mem_reclaim(sk); 1898 1899 /* As outlined in RFC 2525, section 2.17, we send a RST here because 1900 * data was lost. To witness the awful effects of the old behavior of 1901 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 1902 * GET in an FTP client, suspend the process, wait for the client to 1903 * advertise a zero window, then kill -9 the FTP client, wheee... 1904 * Note: timeout is always zero in such a case. 1905 */ 1906 if (data_was_unread) { 1907 /* Unread data was tossed, zap the connection. */ 1908 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 1909 tcp_set_state(sk, TCP_CLOSE); 1910 tcp_send_active_reset(sk, sk->sk_allocation); 1911 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1912 /* Check zero linger _after_ checking for unread data. */ 1913 sk->sk_prot->disconnect(sk, 0); 1914 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 1915 } else if (tcp_close_state(sk)) { 1916 /* We FIN if the application ate all the data before 1917 * zapping the connection. 1918 */ 1919 1920 /* RED-PEN. Formally speaking, we have broken TCP state 1921 * machine. State transitions: 1922 * 1923 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 1924 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 1925 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 1926 * 1927 * are legal only when FIN has been sent (i.e. in window), 1928 * rather than queued out of window. Purists blame. 1929 * 1930 * F.e. "RFC state" is ESTABLISHED, 1931 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 1932 * 1933 * The visible declinations are that sometimes 1934 * we enter time-wait state, when it is not required really 1935 * (harmless), do not send active resets, when they are 1936 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 1937 * they look as CLOSING or LAST_ACK for Linux) 1938 * Probably, I missed some more holelets. 1939 * --ANK 1940 */ 1941 tcp_send_fin(sk); 1942 } 1943 1944 sk_stream_wait_close(sk, timeout); 1945 1946adjudge_to_death: 1947 state = sk->sk_state; 1948 sock_hold(sk); 1949 sock_orphan(sk); 1950 1951 /* It is the last release_sock in its life. It will remove backlog. */ 1952 release_sock(sk); 1953 1954 1955 /* Now socket is owned by kernel and we acquire BH lock 1956 to finish close. No need to check for user refs. 1957 */ 1958 local_bh_disable(); 1959 bh_lock_sock(sk); 1960 WARN_ON(sock_owned_by_user(sk)); 1961 1962 percpu_counter_inc(sk->sk_prot->orphan_count); 1963 1964 /* Have we already been destroyed by a softirq or backlog? */ 1965 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 1966 goto out; 1967 1968 /* This is a (useful) BSD violating of the RFC. There is a 1969 * problem with TCP as specified in that the other end could 1970 * keep a socket open forever with no application left this end. 1971 * We use a 3 minute timeout (about the same as BSD) then kill 1972 * our end. If they send after that then tough - BUT: long enough 1973 * that we won't make the old 4*rto = almost no time - whoops 1974 * reset mistake. 1975 * 1976 * Nope, it was not mistake. It is really desired behaviour 1977 * f.e. on http servers, when such sockets are useless, but 1978 * consume significant resources. Let's do it with special 1979 * linger2 option. --ANK 1980 */ 1981 1982 if (sk->sk_state == TCP_FIN_WAIT2) { 1983 struct tcp_sock *tp = tcp_sk(sk); 1984 if (tp->linger2 < 0) { 1985 tcp_set_state(sk, TCP_CLOSE); 1986 tcp_send_active_reset(sk, GFP_ATOMIC); 1987 NET_INC_STATS_BH(sock_net(sk), 1988 LINUX_MIB_TCPABORTONLINGER); 1989 } else { 1990 const int tmo = tcp_fin_time(sk); 1991 1992 if (tmo > TCP_TIMEWAIT_LEN) { 1993 inet_csk_reset_keepalive_timer(sk, 1994 tmo - TCP_TIMEWAIT_LEN); 1995 } else { 1996 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 1997 goto out; 1998 } 1999 } 2000 } 2001 if (sk->sk_state != TCP_CLOSE) { 2002 int orphan_count = percpu_counter_read_positive( 2003 sk->sk_prot->orphan_count); 2004 2005 sk_mem_reclaim(sk); 2006 if (tcp_too_many_orphans(sk, orphan_count)) { 2007 if (net_ratelimit()) 2008 printk(KERN_INFO "TCP: too many of orphaned " 2009 "sockets\n"); 2010 tcp_set_state(sk, TCP_CLOSE); 2011 tcp_send_active_reset(sk, GFP_ATOMIC); 2012 NET_INC_STATS_BH(sock_net(sk), 2013 LINUX_MIB_TCPABORTONMEMORY); 2014 } 2015 } 2016 2017 if (sk->sk_state == TCP_CLOSE) 2018 inet_csk_destroy_sock(sk); 2019 /* Otherwise, socket is reprieved until protocol close. */ 2020 2021out: 2022 bh_unlock_sock(sk); 2023 local_bh_enable(); 2024 sock_put(sk); 2025} 2026 2027/* These states need RST on ABORT according to RFC793 */ 2028 2029static inline int tcp_need_reset(int state) 2030{ 2031 return (1 << state) & 2032 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2033 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2034} 2035 2036int tcp_disconnect(struct sock *sk, int flags) 2037{ 2038 struct inet_sock *inet = inet_sk(sk); 2039 struct inet_connection_sock *icsk = inet_csk(sk); 2040 struct tcp_sock *tp = tcp_sk(sk); 2041 int err = 0; 2042 int old_state = sk->sk_state; 2043 2044 if (old_state != TCP_CLOSE) 2045 tcp_set_state(sk, TCP_CLOSE); 2046 2047 /* ABORT function of RFC793 */ 2048 if (old_state == TCP_LISTEN) { 2049 inet_csk_listen_stop(sk); 2050 } else if (tcp_need_reset(old_state) || 2051 (tp->snd_nxt != tp->write_seq && 2052 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2053 /* The last check adjusts for discrepancy of Linux wrt. RFC 2054 * states 2055 */ 2056 tcp_send_active_reset(sk, gfp_any()); 2057 sk->sk_err = ECONNRESET; 2058 } else if (old_state == TCP_SYN_SENT) 2059 sk->sk_err = ECONNRESET; 2060 2061 tcp_clear_xmit_timers(sk); 2062 __skb_queue_purge(&sk->sk_receive_queue); 2063 tcp_write_queue_purge(sk); 2064 __skb_queue_purge(&tp->out_of_order_queue); 2065#ifdef CONFIG_NET_DMA 2066 __skb_queue_purge(&sk->sk_async_wait_queue); 2067#endif 2068 2069 inet->inet_dport = 0; 2070 2071 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2072 inet_reset_saddr(sk); 2073 2074 sk->sk_shutdown = 0; 2075 sock_reset_flag(sk, SOCK_DONE); 2076 tp->srtt = 0; 2077 if ((tp->write_seq += tp->max_window + 2) == 0) 2078 tp->write_seq = 1; 2079 icsk->icsk_backoff = 0; 2080 tp->snd_cwnd = 2; 2081 icsk->icsk_probes_out = 0; 2082 tp->packets_out = 0; 2083 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2084 tp->snd_cwnd_cnt = 0; 2085 tp->bytes_acked = 0; 2086 tp->window_clamp = 0; 2087 tcp_set_ca_state(sk, TCP_CA_Open); 2088 tcp_clear_retrans(tp); 2089 inet_csk_delack_init(sk); 2090 tcp_init_send_head(sk); 2091 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2092 __sk_dst_reset(sk); 2093 2094 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2095 2096 sk->sk_error_report(sk); 2097 return err; 2098} 2099 2100/* 2101 * Socket option code for TCP. 2102 */ 2103static int do_tcp_setsockopt(struct sock *sk, int level, 2104 int optname, char __user *optval, unsigned int optlen) 2105{ 2106 struct tcp_sock *tp = tcp_sk(sk); 2107 struct inet_connection_sock *icsk = inet_csk(sk); 2108 int val; 2109 int err = 0; 2110 2111 /* These are data/string values, all the others are ints */ 2112 switch (optname) { 2113 case TCP_CONGESTION: { 2114 char name[TCP_CA_NAME_MAX]; 2115 2116 if (optlen < 1) 2117 return -EINVAL; 2118 2119 val = strncpy_from_user(name, optval, 2120 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2121 if (val < 0) 2122 return -EFAULT; 2123 name[val] = 0; 2124 2125 lock_sock(sk); 2126 err = tcp_set_congestion_control(sk, name); 2127 release_sock(sk); 2128 return err; 2129 } 2130 case TCP_COOKIE_TRANSACTIONS: { 2131 struct tcp_cookie_transactions ctd; 2132 struct tcp_cookie_values *cvp = NULL; 2133 2134 if (sizeof(ctd) > optlen) 2135 return -EINVAL; 2136 if (copy_from_user(&ctd, optval, sizeof(ctd))) 2137 return -EFAULT; 2138 2139 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) || 2140 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED) 2141 return -EINVAL; 2142 2143 if (ctd.tcpct_cookie_desired == 0) { 2144 /* default to global value */ 2145 } else if ((0x1 & ctd.tcpct_cookie_desired) || 2146 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX || 2147 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) { 2148 return -EINVAL; 2149 } 2150 2151 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) { 2152 /* Supercedes all other values */ 2153 lock_sock(sk); 2154 if (tp->cookie_values != NULL) { 2155 kref_put(&tp->cookie_values->kref, 2156 tcp_cookie_values_release); 2157 tp->cookie_values = NULL; 2158 } 2159 tp->rx_opt.cookie_in_always = 0; /* false */ 2160 tp->rx_opt.cookie_out_never = 1; /* true */ 2161 release_sock(sk); 2162 return err; 2163 } 2164 2165 /* Allocate ancillary memory before locking. 2166 */ 2167 if (ctd.tcpct_used > 0 || 2168 (tp->cookie_values == NULL && 2169 (sysctl_tcp_cookie_size > 0 || 2170 ctd.tcpct_cookie_desired > 0 || 2171 ctd.tcpct_s_data_desired > 0))) { 2172 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used, 2173 GFP_KERNEL); 2174 if (cvp == NULL) 2175 return -ENOMEM; 2176 } 2177 lock_sock(sk); 2178 tp->rx_opt.cookie_in_always = 2179 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags); 2180 tp->rx_opt.cookie_out_never = 0; /* false */ 2181 2182 if (tp->cookie_values != NULL) { 2183 if (cvp != NULL) { 2184 /* Changed values are recorded by a changed 2185 * pointer, ensuring the cookie will differ, 2186 * without separately hashing each value later. 2187 */ 2188 kref_put(&tp->cookie_values->kref, 2189 tcp_cookie_values_release); 2190 kref_init(&cvp->kref); 2191 tp->cookie_values = cvp; 2192 } else { 2193 cvp = tp->cookie_values; 2194 } 2195 } 2196 if (cvp != NULL) { 2197 cvp->cookie_desired = ctd.tcpct_cookie_desired; 2198 2199 if (ctd.tcpct_used > 0) { 2200 memcpy(cvp->s_data_payload, ctd.tcpct_value, 2201 ctd.tcpct_used); 2202 cvp->s_data_desired = ctd.tcpct_used; 2203 cvp->s_data_constant = 1; /* true */ 2204 } else { 2205 /* No constant payload data. */ 2206 cvp->s_data_desired = ctd.tcpct_s_data_desired; 2207 cvp->s_data_constant = 0; /* false */ 2208 } 2209 } 2210 release_sock(sk); 2211 return err; 2212 } 2213 default: 2214 /* fallthru */ 2215 break; 2216 }; 2217 2218 if (optlen < sizeof(int)) 2219 return -EINVAL; 2220 2221 if (get_user(val, (int __user *)optval)) 2222 return -EFAULT; 2223 2224 lock_sock(sk); 2225 2226 switch (optname) { 2227 case TCP_MAXSEG: 2228 /* Values greater than interface MTU won't take effect. However 2229 * at the point when this call is done we typically don't yet 2230 * know which interface is going to be used */ 2231 if (val < 8 || val > MAX_TCP_WINDOW) { 2232 err = -EINVAL; 2233 break; 2234 } 2235 tp->rx_opt.user_mss = val; 2236 break; 2237 2238 case TCP_NODELAY: 2239 if (val) { 2240 /* TCP_NODELAY is weaker than TCP_CORK, so that 2241 * this option on corked socket is remembered, but 2242 * it is not activated until cork is cleared. 2243 * 2244 * However, when TCP_NODELAY is set we make 2245 * an explicit push, which overrides even TCP_CORK 2246 * for currently queued segments. 2247 */ 2248 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2249 tcp_push_pending_frames(sk); 2250 } else { 2251 tp->nonagle &= ~TCP_NAGLE_OFF; 2252 } 2253 break; 2254 2255 case TCP_THIN_LINEAR_TIMEOUTS: 2256 if (val < 0 || val > 1) 2257 err = -EINVAL; 2258 else 2259 tp->thin_lto = val; 2260 break; 2261 2262 case TCP_THIN_DUPACK: 2263 if (val < 0 || val > 1) 2264 err = -EINVAL; 2265 else 2266 tp->thin_dupack = val; 2267 break; 2268 2269 case TCP_CORK: 2270 /* When set indicates to always queue non-full frames. 2271 * Later the user clears this option and we transmit 2272 * any pending partial frames in the queue. This is 2273 * meant to be used alongside sendfile() to get properly 2274 * filled frames when the user (for example) must write 2275 * out headers with a write() call first and then use 2276 * sendfile to send out the data parts. 2277 * 2278 * TCP_CORK can be set together with TCP_NODELAY and it is 2279 * stronger than TCP_NODELAY. 2280 */ 2281 if (val) { 2282 tp->nonagle |= TCP_NAGLE_CORK; 2283 } else { 2284 tp->nonagle &= ~TCP_NAGLE_CORK; 2285 if (tp->nonagle&TCP_NAGLE_OFF) 2286 tp->nonagle |= TCP_NAGLE_PUSH; 2287 tcp_push_pending_frames(sk); 2288 } 2289 break; 2290 2291 case TCP_KEEPIDLE: 2292 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2293 err = -EINVAL; 2294 else { 2295 tp->keepalive_time = val * HZ; 2296 if (sock_flag(sk, SOCK_KEEPOPEN) && 2297 !((1 << sk->sk_state) & 2298 (TCPF_CLOSE | TCPF_LISTEN))) { 2299 __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp; 2300 if (tp->keepalive_time > elapsed) 2301 elapsed = tp->keepalive_time - elapsed; 2302 else 2303 elapsed = 0; 2304 inet_csk_reset_keepalive_timer(sk, elapsed); 2305 } 2306 } 2307 break; 2308 case TCP_KEEPINTVL: 2309 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2310 err = -EINVAL; 2311 else 2312 tp->keepalive_intvl = val * HZ; 2313 break; 2314 case TCP_KEEPCNT: 2315 if (val < 1 || val > MAX_TCP_KEEPCNT) 2316 err = -EINVAL; 2317 else 2318 tp->keepalive_probes = val; 2319 break; 2320 case TCP_SYNCNT: 2321 if (val < 1 || val > MAX_TCP_SYNCNT) 2322 err = -EINVAL; 2323 else 2324 icsk->icsk_syn_retries = val; 2325 break; 2326 2327 case TCP_LINGER2: 2328 if (val < 0) 2329 tp->linger2 = -1; 2330 else if (val > sysctl_tcp_fin_timeout / HZ) 2331 tp->linger2 = 0; 2332 else 2333 tp->linger2 = val * HZ; 2334 break; 2335 2336 case TCP_DEFER_ACCEPT: 2337 /* Translate value in seconds to number of retransmits */ 2338 icsk->icsk_accept_queue.rskq_defer_accept = 2339 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2340 TCP_RTO_MAX / HZ); 2341 break; 2342 2343 case TCP_WINDOW_CLAMP: 2344 if (!val) { 2345 if (sk->sk_state != TCP_CLOSE) { 2346 err = -EINVAL; 2347 break; 2348 } 2349 tp->window_clamp = 0; 2350 } else 2351 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2352 SOCK_MIN_RCVBUF / 2 : val; 2353 break; 2354 2355 case TCP_QUICKACK: 2356 if (!val) { 2357 icsk->icsk_ack.pingpong = 1; 2358 } else { 2359 icsk->icsk_ack.pingpong = 0; 2360 if ((1 << sk->sk_state) & 2361 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2362 inet_csk_ack_scheduled(sk)) { 2363 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2364 tcp_cleanup_rbuf(sk, 1); 2365 if (!(val & 1)) 2366 icsk->icsk_ack.pingpong = 1; 2367 } 2368 } 2369 break; 2370 2371#ifdef CONFIG_TCP_MD5SIG 2372 case TCP_MD5SIG: 2373 /* Read the IP->Key mappings from userspace */ 2374 err = tp->af_specific->md5_parse(sk, optval, optlen); 2375 break; 2376#endif 2377 2378 default: 2379 err = -ENOPROTOOPT; 2380 break; 2381 } 2382 2383 release_sock(sk); 2384 return err; 2385} 2386 2387int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2388 unsigned int optlen) 2389{ 2390 struct inet_connection_sock *icsk = inet_csk(sk); 2391 2392 if (level != SOL_TCP) 2393 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2394 optval, optlen); 2395 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2396} 2397 2398#ifdef CONFIG_COMPAT 2399int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2400 char __user *optval, unsigned int optlen) 2401{ 2402 if (level != SOL_TCP) 2403 return inet_csk_compat_setsockopt(sk, level, optname, 2404 optval, optlen); 2405 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2406} 2407 2408EXPORT_SYMBOL(compat_tcp_setsockopt); 2409#endif 2410 2411/* Return information about state of tcp endpoint in API format. */ 2412void tcp_get_info(struct sock *sk, struct tcp_info *info) 2413{ 2414 struct tcp_sock *tp = tcp_sk(sk); 2415 const struct inet_connection_sock *icsk = inet_csk(sk); 2416 u32 now = tcp_time_stamp; 2417 2418 memset(info, 0, sizeof(*info)); 2419 2420 info->tcpi_state = sk->sk_state; 2421 info->tcpi_ca_state = icsk->icsk_ca_state; 2422 info->tcpi_retransmits = icsk->icsk_retransmits; 2423 info->tcpi_probes = icsk->icsk_probes_out; 2424 info->tcpi_backoff = icsk->icsk_backoff; 2425 2426 if (tp->rx_opt.tstamp_ok) 2427 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2428 if (tcp_is_sack(tp)) 2429 info->tcpi_options |= TCPI_OPT_SACK; 2430 if (tp->rx_opt.wscale_ok) { 2431 info->tcpi_options |= TCPI_OPT_WSCALE; 2432 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2433 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2434 } 2435 2436 if (tp->ecn_flags&TCP_ECN_OK) 2437 info->tcpi_options |= TCPI_OPT_ECN; 2438 2439 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2440 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2441 info->tcpi_snd_mss = tp->mss_cache; 2442 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2443 2444 if (sk->sk_state == TCP_LISTEN) { 2445 info->tcpi_unacked = sk->sk_ack_backlog; 2446 info->tcpi_sacked = sk->sk_max_ack_backlog; 2447 } else { 2448 info->tcpi_unacked = tp->packets_out; 2449 info->tcpi_sacked = tp->sacked_out; 2450 } 2451 info->tcpi_lost = tp->lost_out; 2452 info->tcpi_retrans = tp->retrans_out; 2453 info->tcpi_fackets = tp->fackets_out; 2454 2455 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2456 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2457 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2458 2459 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2460 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2461 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3; 2462 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2; 2463 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2464 info->tcpi_snd_cwnd = tp->snd_cwnd; 2465 info->tcpi_advmss = tp->advmss; 2466 info->tcpi_reordering = tp->reordering; 2467 2468 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; 2469 info->tcpi_rcv_space = tp->rcvq_space.space; 2470 2471 info->tcpi_total_retrans = tp->total_retrans; 2472} 2473 2474EXPORT_SYMBOL_GPL(tcp_get_info); 2475 2476static int do_tcp_getsockopt(struct sock *sk, int level, 2477 int optname, char __user *optval, int __user *optlen) 2478{ 2479 struct inet_connection_sock *icsk = inet_csk(sk); 2480 struct tcp_sock *tp = tcp_sk(sk); 2481 int val, len; 2482 2483 if (get_user(len, optlen)) 2484 return -EFAULT; 2485 2486 len = min_t(unsigned int, len, sizeof(int)); 2487 2488 if (len < 0) 2489 return -EINVAL; 2490 2491 switch (optname) { 2492 case TCP_MAXSEG: 2493 val = tp->mss_cache; 2494 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2495 val = tp->rx_opt.user_mss; 2496 break; 2497 case TCP_NODELAY: 2498 val = !!(tp->nonagle&TCP_NAGLE_OFF); 2499 break; 2500 case TCP_CORK: 2501 val = !!(tp->nonagle&TCP_NAGLE_CORK); 2502 break; 2503 case TCP_KEEPIDLE: 2504 val = keepalive_time_when(tp) / HZ; 2505 break; 2506 case TCP_KEEPINTVL: 2507 val = keepalive_intvl_when(tp) / HZ; 2508 break; 2509 case TCP_KEEPCNT: 2510 val = keepalive_probes(tp); 2511 break; 2512 case TCP_SYNCNT: 2513 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 2514 break; 2515 case TCP_LINGER2: 2516 val = tp->linger2; 2517 if (val >= 0) 2518 val = (val ? : sysctl_tcp_fin_timeout) / HZ; 2519 break; 2520 case TCP_DEFER_ACCEPT: 2521 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 2522 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 2523 break; 2524 case TCP_WINDOW_CLAMP: 2525 val = tp->window_clamp; 2526 break; 2527 case TCP_INFO: { 2528 struct tcp_info info; 2529 2530 if (get_user(len, optlen)) 2531 return -EFAULT; 2532 2533 tcp_get_info(sk, &info); 2534 2535 len = min_t(unsigned int, len, sizeof(info)); 2536 if (put_user(len, optlen)) 2537 return -EFAULT; 2538 if (copy_to_user(optval, &info, len)) 2539 return -EFAULT; 2540 return 0; 2541 } 2542 case TCP_QUICKACK: 2543 val = !icsk->icsk_ack.pingpong; 2544 break; 2545 2546 case TCP_CONGESTION: 2547 if (get_user(len, optlen)) 2548 return -EFAULT; 2549 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 2550 if (put_user(len, optlen)) 2551 return -EFAULT; 2552 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 2553 return -EFAULT; 2554 return 0; 2555 2556 case TCP_COOKIE_TRANSACTIONS: { 2557 struct tcp_cookie_transactions ctd; 2558 struct tcp_cookie_values *cvp = tp->cookie_values; 2559 2560 if (get_user(len, optlen)) 2561 return -EFAULT; 2562 if (len < sizeof(ctd)) 2563 return -EINVAL; 2564 2565 memset(&ctd, 0, sizeof(ctd)); 2566 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ? 2567 TCP_COOKIE_IN_ALWAYS : 0) 2568 | (tp->rx_opt.cookie_out_never ? 2569 TCP_COOKIE_OUT_NEVER : 0); 2570 2571 if (cvp != NULL) { 2572 ctd.tcpct_flags |= (cvp->s_data_in ? 2573 TCP_S_DATA_IN : 0) 2574 | (cvp->s_data_out ? 2575 TCP_S_DATA_OUT : 0); 2576 2577 ctd.tcpct_cookie_desired = cvp->cookie_desired; 2578 ctd.tcpct_s_data_desired = cvp->s_data_desired; 2579 2580 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0], 2581 cvp->cookie_pair_size); 2582 ctd.tcpct_used = cvp->cookie_pair_size; 2583 } 2584 2585 if (put_user(sizeof(ctd), optlen)) 2586 return -EFAULT; 2587 if (copy_to_user(optval, &ctd, sizeof(ctd))) 2588 return -EFAULT; 2589 return 0; 2590 } 2591 default: 2592 return -ENOPROTOOPT; 2593 } 2594 2595 if (put_user(len, optlen)) 2596 return -EFAULT; 2597 if (copy_to_user(optval, &val, len)) 2598 return -EFAULT; 2599 return 0; 2600} 2601 2602int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 2603 int __user *optlen) 2604{ 2605 struct inet_connection_sock *icsk = inet_csk(sk); 2606 2607 if (level != SOL_TCP) 2608 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 2609 optval, optlen); 2610 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2611} 2612 2613#ifdef CONFIG_COMPAT 2614int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 2615 char __user *optval, int __user *optlen) 2616{ 2617 if (level != SOL_TCP) 2618 return inet_csk_compat_getsockopt(sk, level, optname, 2619 optval, optlen); 2620 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2621} 2622 2623EXPORT_SYMBOL(compat_tcp_getsockopt); 2624#endif 2625 2626struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features) 2627{ 2628 struct sk_buff *segs = ERR_PTR(-EINVAL); 2629 struct tcphdr *th; 2630 unsigned thlen; 2631 unsigned int seq; 2632 __be32 delta; 2633 unsigned int oldlen; 2634 unsigned int mss; 2635 2636 if (!pskb_may_pull(skb, sizeof(*th))) 2637 goto out; 2638 2639 th = tcp_hdr(skb); 2640 thlen = th->doff * 4; 2641 if (thlen < sizeof(*th)) 2642 goto out; 2643 2644 if (!pskb_may_pull(skb, thlen)) 2645 goto out; 2646 2647 oldlen = (u16)~skb->len; 2648 __skb_pull(skb, thlen); 2649 2650 mss = skb_shinfo(skb)->gso_size; 2651 if (unlikely(skb->len <= mss)) 2652 goto out; 2653 2654 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2655 /* Packet is from an untrusted source, reset gso_segs. */ 2656 int type = skb_shinfo(skb)->gso_type; 2657 2658 if (unlikely(type & 2659 ~(SKB_GSO_TCPV4 | 2660 SKB_GSO_DODGY | 2661 SKB_GSO_TCP_ECN | 2662 SKB_GSO_TCPV6 | 2663 0) || 2664 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))) 2665 goto out; 2666 2667 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2668 2669 segs = NULL; 2670 goto out; 2671 } 2672 2673 segs = skb_segment(skb, features); 2674 if (IS_ERR(segs)) 2675 goto out; 2676 2677 delta = htonl(oldlen + (thlen + mss)); 2678 2679 skb = segs; 2680 th = tcp_hdr(skb); 2681 seq = ntohl(th->seq); 2682 2683 do { 2684 th->fin = th->psh = 0; 2685 2686 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2687 (__force u32)delta)); 2688 if (skb->ip_summed != CHECKSUM_PARTIAL) 2689 th->check = 2690 csum_fold(csum_partial(skb_transport_header(skb), 2691 thlen, skb->csum)); 2692 2693 seq += mss; 2694 skb = skb->next; 2695 th = tcp_hdr(skb); 2696 2697 th->seq = htonl(seq); 2698 th->cwr = 0; 2699 } while (skb->next); 2700 2701 delta = htonl(oldlen + (skb->tail - skb->transport_header) + 2702 skb->data_len); 2703 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2704 (__force u32)delta)); 2705 if (skb->ip_summed != CHECKSUM_PARTIAL) 2706 th->check = csum_fold(csum_partial(skb_transport_header(skb), 2707 thlen, skb->csum)); 2708 2709out: 2710 return segs; 2711} 2712EXPORT_SYMBOL(tcp_tso_segment); 2713 2714struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) 2715{ 2716 struct sk_buff **pp = NULL; 2717 struct sk_buff *p; 2718 struct tcphdr *th; 2719 struct tcphdr *th2; 2720 unsigned int len; 2721 unsigned int thlen; 2722 unsigned int flags; 2723 unsigned int mss = 1; 2724 unsigned int hlen; 2725 unsigned int off; 2726 int flush = 1; 2727 int i; 2728 2729 off = skb_gro_offset(skb); 2730 hlen = off + sizeof(*th); 2731 th = skb_gro_header_fast(skb, off); 2732 if (skb_gro_header_hard(skb, hlen)) { 2733 th = skb_gro_header_slow(skb, hlen, off); 2734 if (unlikely(!th)) 2735 goto out; 2736 } 2737 2738 thlen = th->doff * 4; 2739 if (thlen < sizeof(*th)) 2740 goto out; 2741 2742 hlen = off + thlen; 2743 if (skb_gro_header_hard(skb, hlen)) { 2744 th = skb_gro_header_slow(skb, hlen, off); 2745 if (unlikely(!th)) 2746 goto out; 2747 } 2748 2749 skb_gro_pull(skb, thlen); 2750 2751 len = skb_gro_len(skb); 2752 flags = tcp_flag_word(th); 2753 2754 for (; (p = *head); head = &p->next) { 2755 if (!NAPI_GRO_CB(p)->same_flow) 2756 continue; 2757 2758 th2 = tcp_hdr(p); 2759 2760 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) { 2761 NAPI_GRO_CB(p)->same_flow = 0; 2762 continue; 2763 } 2764 2765 goto found; 2766 } 2767 2768 goto out_check_final; 2769 2770found: 2771 flush = NAPI_GRO_CB(p)->flush; 2772 flush |= flags & TCP_FLAG_CWR; 2773 flush |= (flags ^ tcp_flag_word(th2)) & 2774 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH); 2775 flush |= th->ack_seq ^ th2->ack_seq; 2776 for (i = sizeof(*th); i < thlen; i += 4) 2777 flush |= *(u32 *)((u8 *)th + i) ^ 2778 *(u32 *)((u8 *)th2 + i); 2779 2780 mss = skb_shinfo(p)->gso_size; 2781 2782 flush |= (len - 1) >= mss; 2783 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); 2784 2785 if (flush || skb_gro_receive(head, skb)) { 2786 mss = 1; 2787 goto out_check_final; 2788 } 2789 2790 p = *head; 2791 th2 = tcp_hdr(p); 2792 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); 2793 2794out_check_final: 2795 flush = len < mss; 2796 flush |= flags & (TCP_FLAG_URG | TCP_FLAG_PSH | TCP_FLAG_RST | 2797 TCP_FLAG_SYN | TCP_FLAG_FIN); 2798 2799 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush)) 2800 pp = head; 2801 2802out: 2803 NAPI_GRO_CB(skb)->flush |= flush; 2804 2805 return pp; 2806} 2807EXPORT_SYMBOL(tcp_gro_receive); 2808 2809int tcp_gro_complete(struct sk_buff *skb) 2810{ 2811 struct tcphdr *th = tcp_hdr(skb); 2812 2813 skb->csum_start = skb_transport_header(skb) - skb->head; 2814 skb->csum_offset = offsetof(struct tcphdr, check); 2815 skb->ip_summed = CHECKSUM_PARTIAL; 2816 2817 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 2818 2819 if (th->cwr) 2820 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 2821 2822 return 0; 2823} 2824EXPORT_SYMBOL(tcp_gro_complete); 2825 2826#ifdef CONFIG_TCP_MD5SIG 2827static unsigned long tcp_md5sig_users; 2828static struct tcp_md5sig_pool * __percpu *tcp_md5sig_pool; 2829static DEFINE_SPINLOCK(tcp_md5sig_pool_lock); 2830 2831static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool * __percpu *pool) 2832{ 2833 int cpu; 2834 for_each_possible_cpu(cpu) { 2835 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu); 2836 if (p) { 2837 if (p->md5_desc.tfm) 2838 crypto_free_hash(p->md5_desc.tfm); 2839 kfree(p); 2840 p = NULL; 2841 } 2842 } 2843 free_percpu(pool); 2844} 2845 2846void tcp_free_md5sig_pool(void) 2847{ 2848 struct tcp_md5sig_pool * __percpu *pool = NULL; 2849 2850 spin_lock_bh(&tcp_md5sig_pool_lock); 2851 if (--tcp_md5sig_users == 0) { 2852 pool = tcp_md5sig_pool; 2853 tcp_md5sig_pool = NULL; 2854 } 2855 spin_unlock_bh(&tcp_md5sig_pool_lock); 2856 if (pool) 2857 __tcp_free_md5sig_pool(pool); 2858} 2859 2860EXPORT_SYMBOL(tcp_free_md5sig_pool); 2861 2862static struct tcp_md5sig_pool * __percpu * 2863__tcp_alloc_md5sig_pool(struct sock *sk) 2864{ 2865 int cpu; 2866 struct tcp_md5sig_pool * __percpu *pool; 2867 2868 pool = alloc_percpu(struct tcp_md5sig_pool *); 2869 if (!pool) 2870 return NULL; 2871 2872 for_each_possible_cpu(cpu) { 2873 struct tcp_md5sig_pool *p; 2874 struct crypto_hash *hash; 2875 2876 p = kzalloc(sizeof(*p), sk->sk_allocation); 2877 if (!p) 2878 goto out_free; 2879 *per_cpu_ptr(pool, cpu) = p; 2880 2881 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 2882 if (!hash || IS_ERR(hash)) 2883 goto out_free; 2884 2885 p->md5_desc.tfm = hash; 2886 } 2887 return pool; 2888out_free: 2889 __tcp_free_md5sig_pool(pool); 2890 return NULL; 2891} 2892 2893struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *sk) 2894{ 2895 struct tcp_md5sig_pool * __percpu *pool; 2896 int alloc = 0; 2897 2898retry: 2899 spin_lock_bh(&tcp_md5sig_pool_lock); 2900 pool = tcp_md5sig_pool; 2901 if (tcp_md5sig_users++ == 0) { 2902 alloc = 1; 2903 spin_unlock_bh(&tcp_md5sig_pool_lock); 2904 } else if (!pool) { 2905 tcp_md5sig_users--; 2906 spin_unlock_bh(&tcp_md5sig_pool_lock); 2907 cpu_relax(); 2908 goto retry; 2909 } else 2910 spin_unlock_bh(&tcp_md5sig_pool_lock); 2911 2912 if (alloc) { 2913 /* we cannot hold spinlock here because this may sleep. */ 2914 struct tcp_md5sig_pool * __percpu *p; 2915 2916 p = __tcp_alloc_md5sig_pool(sk); 2917 spin_lock_bh(&tcp_md5sig_pool_lock); 2918 if (!p) { 2919 tcp_md5sig_users--; 2920 spin_unlock_bh(&tcp_md5sig_pool_lock); 2921 return NULL; 2922 } 2923 pool = tcp_md5sig_pool; 2924 if (pool) { 2925 /* oops, it has already been assigned. */ 2926 spin_unlock_bh(&tcp_md5sig_pool_lock); 2927 __tcp_free_md5sig_pool(p); 2928 } else { 2929 tcp_md5sig_pool = pool = p; 2930 spin_unlock_bh(&tcp_md5sig_pool_lock); 2931 } 2932 } 2933 return pool; 2934} 2935 2936EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 2937 2938struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu) 2939{ 2940 struct tcp_md5sig_pool * __percpu *p; 2941 spin_lock_bh(&tcp_md5sig_pool_lock); 2942 p = tcp_md5sig_pool; 2943 if (p) 2944 tcp_md5sig_users++; 2945 spin_unlock_bh(&tcp_md5sig_pool_lock); 2946 return (p ? *per_cpu_ptr(p, cpu) : NULL); 2947} 2948 2949EXPORT_SYMBOL(__tcp_get_md5sig_pool); 2950 2951void __tcp_put_md5sig_pool(void) 2952{ 2953 tcp_free_md5sig_pool(); 2954} 2955 2956EXPORT_SYMBOL(__tcp_put_md5sig_pool); 2957 2958int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, 2959 struct tcphdr *th) 2960{ 2961 struct scatterlist sg; 2962 int err; 2963 2964 __sum16 old_checksum = th->check; 2965 th->check = 0; 2966 /* options aren't included in the hash */ 2967 sg_init_one(&sg, th, sizeof(struct tcphdr)); 2968 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr)); 2969 th->check = old_checksum; 2970 return err; 2971} 2972 2973EXPORT_SYMBOL(tcp_md5_hash_header); 2974 2975int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 2976 struct sk_buff *skb, unsigned header_len) 2977{ 2978 struct scatterlist sg; 2979 const struct tcphdr *tp = tcp_hdr(skb); 2980 struct hash_desc *desc = &hp->md5_desc; 2981 unsigned i; 2982 const unsigned head_data_len = skb_headlen(skb) > header_len ? 2983 skb_headlen(skb) - header_len : 0; 2984 const struct skb_shared_info *shi = skb_shinfo(skb); 2985 2986 sg_init_table(&sg, 1); 2987 2988 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 2989 if (crypto_hash_update(desc, &sg, head_data_len)) 2990 return 1; 2991 2992 for (i = 0; i < shi->nr_frags; ++i) { 2993 const struct skb_frag_struct *f = &shi->frags[i]; 2994 sg_set_page(&sg, f->page, f->size, f->page_offset); 2995 if (crypto_hash_update(desc, &sg, f->size)) 2996 return 1; 2997 } 2998 2999 return 0; 3000} 3001 3002EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3003 3004int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key) 3005{ 3006 struct scatterlist sg; 3007 3008 sg_init_one(&sg, key->key, key->keylen); 3009 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); 3010} 3011 3012EXPORT_SYMBOL(tcp_md5_hash_key); 3013 3014#endif 3015 3016/** 3017 * Each Responder maintains up to two secret values concurrently for 3018 * efficient secret rollover. Each secret value has 4 states: 3019 * 3020 * Generating. (tcp_secret_generating != tcp_secret_primary) 3021 * Generates new Responder-Cookies, but not yet used for primary 3022 * verification. This is a short-term state, typically lasting only 3023 * one round trip time (RTT). 3024 * 3025 * Primary. (tcp_secret_generating == tcp_secret_primary) 3026 * Used both for generation and primary verification. 3027 * 3028 * Retiring. (tcp_secret_retiring != tcp_secret_secondary) 3029 * Used for verification, until the first failure that can be 3030 * verified by the newer Generating secret. At that time, this 3031 * cookie's state is changed to Secondary, and the Generating 3032 * cookie's state is changed to Primary. This is a short-term state, 3033 * typically lasting only one round trip time (RTT). 3034 * 3035 * Secondary. (tcp_secret_retiring == tcp_secret_secondary) 3036 * Used for secondary verification, after primary verification 3037 * failures. This state lasts no more than twice the Maximum Segment 3038 * Lifetime (2MSL). Then, the secret is discarded. 3039 */ 3040struct tcp_cookie_secret { 3041 /* The secret is divided into two parts. The digest part is the 3042 * equivalent of previously hashing a secret and saving the state, 3043 * and serves as an initialization vector (IV). The message part 3044 * serves as the trailing secret. 3045 */ 3046 u32 secrets[COOKIE_WORKSPACE_WORDS]; 3047 unsigned long expires; 3048}; 3049 3050#define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL) 3051#define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2) 3052#define TCP_SECRET_LIFE (HZ * 600) 3053 3054static struct tcp_cookie_secret tcp_secret_one; 3055static struct tcp_cookie_secret tcp_secret_two; 3056 3057/* Essentially a circular list, without dynamic allocation. */ 3058static struct tcp_cookie_secret *tcp_secret_generating; 3059static struct tcp_cookie_secret *tcp_secret_primary; 3060static struct tcp_cookie_secret *tcp_secret_retiring; 3061static struct tcp_cookie_secret *tcp_secret_secondary; 3062 3063static DEFINE_SPINLOCK(tcp_secret_locker); 3064 3065/* Select a pseudo-random word in the cookie workspace. 3066 */ 3067static inline u32 tcp_cookie_work(const u32 *ws, const int n) 3068{ 3069 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])]; 3070} 3071 3072/* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed. 3073 * Called in softirq context. 3074 * Returns: 0 for success. 3075 */ 3076int tcp_cookie_generator(u32 *bakery) 3077{ 3078 unsigned long jiffy = jiffies; 3079 3080 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) { 3081 spin_lock_bh(&tcp_secret_locker); 3082 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) { 3083 /* refreshed by another */ 3084 memcpy(bakery, 3085 &tcp_secret_generating->secrets[0], 3086 COOKIE_WORKSPACE_WORDS); 3087 } else { 3088 /* still needs refreshing */ 3089 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS); 3090 3091 /* The first time, paranoia assumes that the 3092 * randomization function isn't as strong. But, 3093 * this secret initialization is delayed until 3094 * the last possible moment (packet arrival). 3095 * Although that time is observable, it is 3096 * unpredictably variable. Mash in the most 3097 * volatile clock bits available, and expire the 3098 * secret extra quickly. 3099 */ 3100 if (unlikely(tcp_secret_primary->expires == 3101 tcp_secret_secondary->expires)) { 3102 struct timespec tv; 3103 3104 getnstimeofday(&tv); 3105 bakery[COOKIE_DIGEST_WORDS+0] ^= 3106 (u32)tv.tv_nsec; 3107 3108 tcp_secret_secondary->expires = jiffy 3109 + TCP_SECRET_1MSL 3110 + (0x0f & tcp_cookie_work(bakery, 0)); 3111 } else { 3112 tcp_secret_secondary->expires = jiffy 3113 + TCP_SECRET_LIFE 3114 + (0xff & tcp_cookie_work(bakery, 1)); 3115 tcp_secret_primary->expires = jiffy 3116 + TCP_SECRET_2MSL 3117 + (0x1f & tcp_cookie_work(bakery, 2)); 3118 } 3119 memcpy(&tcp_secret_secondary->secrets[0], 3120 bakery, COOKIE_WORKSPACE_WORDS); 3121 3122 rcu_assign_pointer(tcp_secret_generating, 3123 tcp_secret_secondary); 3124 rcu_assign_pointer(tcp_secret_retiring, 3125 tcp_secret_primary); 3126 /* 3127 * Neither call_rcu() nor synchronize_rcu() needed. 3128 * Retiring data is not freed. It is replaced after 3129 * further (locked) pointer updates, and a quiet time 3130 * (minimum 1MSL, maximum LIFE - 2MSL). 3131 */ 3132 } 3133 spin_unlock_bh(&tcp_secret_locker); 3134 } else { 3135 rcu_read_lock_bh(); 3136 memcpy(bakery, 3137 &rcu_dereference(tcp_secret_generating)->secrets[0], 3138 COOKIE_WORKSPACE_WORDS); 3139 rcu_read_unlock_bh(); 3140 } 3141 return 0; 3142} 3143EXPORT_SYMBOL(tcp_cookie_generator); 3144 3145void tcp_done(struct sock *sk) 3146{ 3147 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3148 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3149 3150 tcp_set_state(sk, TCP_CLOSE); 3151 tcp_clear_xmit_timers(sk); 3152 3153 sk->sk_shutdown = SHUTDOWN_MASK; 3154 3155 if (!sock_flag(sk, SOCK_DEAD)) 3156 sk->sk_state_change(sk); 3157 else 3158 inet_csk_destroy_sock(sk); 3159} 3160EXPORT_SYMBOL_GPL(tcp_done); 3161 3162extern struct tcp_congestion_ops tcp_reno; 3163 3164static __initdata unsigned long thash_entries; 3165static int __init set_thash_entries(char *str) 3166{ 3167 if (!str) 3168 return 0; 3169 thash_entries = simple_strtoul(str, &str, 0); 3170 return 1; 3171} 3172__setup("thash_entries=", set_thash_entries); 3173 3174void __init tcp_init(void) 3175{ 3176 struct sk_buff *skb = NULL; 3177 unsigned long nr_pages, limit; 3178 int order, i, max_share; 3179 unsigned long jiffy = jiffies; 3180 3181 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); 3182 3183 percpu_counter_init(&tcp_sockets_allocated, 0); 3184 percpu_counter_init(&tcp_orphan_count, 0); 3185 tcp_hashinfo.bind_bucket_cachep = 3186 kmem_cache_create("tcp_bind_bucket", 3187 sizeof(struct inet_bind_bucket), 0, 3188 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3189 3190 /* Size and allocate the main established and bind bucket 3191 * hash tables. 3192 * 3193 * The methodology is similar to that of the buffer cache. 3194 */ 3195 tcp_hashinfo.ehash = 3196 alloc_large_system_hash("TCP established", 3197 sizeof(struct inet_ehash_bucket), 3198 thash_entries, 3199 (totalram_pages >= 128 * 1024) ? 3200 13 : 15, 3201 0, 3202 NULL, 3203 &tcp_hashinfo.ehash_mask, 3204 thash_entries ? 0 : 512 * 1024); 3205 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) { 3206 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3207 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i); 3208 } 3209 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3210 panic("TCP: failed to alloc ehash_locks"); 3211 tcp_hashinfo.bhash = 3212 alloc_large_system_hash("TCP bind", 3213 sizeof(struct inet_bind_hashbucket), 3214 tcp_hashinfo.ehash_mask + 1, 3215 (totalram_pages >= 128 * 1024) ? 3216 13 : 15, 3217 0, 3218 &tcp_hashinfo.bhash_size, 3219 NULL, 3220 64 * 1024); 3221 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size; 3222 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3223 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3224 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3225 } 3226 3227 /* Try to be a bit smarter and adjust defaults depending 3228 * on available memory. 3229 */ 3230 for (order = 0; ((1 << order) << PAGE_SHIFT) < 3231 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket)); 3232 order++) 3233 ; 3234 if (order >= 4) { 3235 tcp_death_row.sysctl_max_tw_buckets = 180000; 3236 sysctl_tcp_max_orphans = 4096 << (order - 4); 3237 sysctl_max_syn_backlog = 1024; 3238 } else if (order < 3) { 3239 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order); 3240 sysctl_tcp_max_orphans >>= (3 - order); 3241 sysctl_max_syn_backlog = 128; 3242 } 3243 3244 /* Set the pressure threshold to be a fraction of global memory that 3245 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of 3246 * memory, with a floor of 128 pages. 3247 */ 3248 nr_pages = totalram_pages - totalhigh_pages; 3249 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); 3250 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); 3251 limit = max(limit, 128UL); 3252 sysctl_tcp_mem[0] = limit / 4 * 3; 3253 sysctl_tcp_mem[1] = limit; 3254 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; 3255 3256 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3257 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7); 3258 max_share = min(4UL*1024*1024, limit); 3259 3260 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3261 sysctl_tcp_wmem[1] = 16*1024; 3262 sysctl_tcp_wmem[2] = max(64*1024, max_share); 3263 3264 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3265 sysctl_tcp_rmem[1] = 87380; 3266 sysctl_tcp_rmem[2] = max(87380, max_share); 3267 3268 printk(KERN_INFO "TCP: Hash tables configured " 3269 "(established %u bind %u)\n", 3270 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3271 3272 tcp_register_congestion_control(&tcp_reno); 3273 3274 memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets)); 3275 memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets)); 3276 tcp_secret_one.expires = jiffy; /* past due */ 3277 tcp_secret_two.expires = jiffy; /* past due */ 3278 tcp_secret_generating = &tcp_secret_one; 3279 tcp_secret_primary = &tcp_secret_one; 3280 tcp_secret_retiring = &tcp_secret_two; 3281 tcp_secret_secondary = &tcp_secret_two; 3282} 3283 3284EXPORT_SYMBOL(tcp_close); 3285EXPORT_SYMBOL(tcp_disconnect); 3286EXPORT_SYMBOL(tcp_getsockopt); 3287EXPORT_SYMBOL(tcp_ioctl); 3288EXPORT_SYMBOL(tcp_poll); 3289EXPORT_SYMBOL(tcp_read_sock); 3290EXPORT_SYMBOL(tcp_recvmsg); 3291EXPORT_SYMBOL(tcp_sendmsg); 3292EXPORT_SYMBOL(tcp_splice_read); 3293EXPORT_SYMBOL(tcp_sendpage); 3294EXPORT_SYMBOL(tcp_setsockopt); 3295EXPORT_SYMBOL(tcp_shutdown); 3296