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 * Version: $Id: tcp.c,v 1.216 2002/02/01 22:01:04 davem Exp $ 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Mark Evans, <evansmp@uhura.aston.ac.uk> 13 * Corey Minyard <wf-rch!minyard@relay.EU.net> 14 * Florian La Roche, <flla@stud.uni-sb.de> 15 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> 16 * Linus Torvalds, <torvalds@cs.helsinki.fi> 17 * Alan Cox, <gw4pts@gw4pts.ampr.org> 18 * Matthew Dillon, <dillon@apollo.west.oic.com> 19 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 20 * Jorge Cwik, <jorge@laser.satlink.net> 21 * 22 * Fixes: 23 * Alan Cox : Numerous verify_area() calls 24 * Alan Cox : Set the ACK bit on a reset 25 * Alan Cox : Stopped it crashing if it closed while 26 * sk->inuse=1 and was trying to connect 27 * (tcp_err()). 28 * Alan Cox : All icmp error handling was broken 29 * pointers passed where wrong and the 30 * socket was looked up backwards. Nobody 31 * tested any icmp error code obviously. 32 * Alan Cox : tcp_err() now handled properly. It 33 * wakes people on errors. poll 34 * behaves and the icmp error race 35 * has gone by moving it into sock.c 36 * Alan Cox : tcp_send_reset() fixed to work for 37 * everything not just packets for 38 * unknown sockets. 39 * Alan Cox : tcp option processing. 40 * Alan Cox : Reset tweaked (still not 100%) [Had 41 * syn rule wrong] 42 * Herp Rosmanith : More reset fixes 43 * Alan Cox : No longer acks invalid rst frames. 44 * Acking any kind of RST is right out. 45 * Alan Cox : Sets an ignore me flag on an rst 46 * receive otherwise odd bits of prattle 47 * escape still 48 * Alan Cox : Fixed another acking RST frame bug. 49 * Should stop LAN workplace lockups. 50 * Alan Cox : Some tidyups using the new skb list 51 * facilities 52 * Alan Cox : sk->keepopen now seems to work 53 * Alan Cox : Pulls options out correctly on accepts 54 * Alan Cox : Fixed assorted sk->rqueue->next errors 55 * Alan Cox : PSH doesn't end a TCP read. Switched a 56 * bit to skb ops. 57 * Alan Cox : Tidied tcp_data to avoid a potential 58 * nasty. 59 * Alan Cox : Added some better commenting, as the 60 * tcp is hard to follow 61 * Alan Cox : Removed incorrect check for 20 * psh 62 * Michael O'Reilly : ack < copied bug fix. 63 * Johannes Stille : Misc tcp fixes (not all in yet). 64 * Alan Cox : FIN with no memory -> CRASH 65 * Alan Cox : Added socket option proto entries. 66 * Also added awareness of them to accept. 67 * Alan Cox : Added TCP options (SOL_TCP) 68 * Alan Cox : Switched wakeup calls to callbacks, 69 * so the kernel can layer network 70 * sockets. 71 * Alan Cox : Use ip_tos/ip_ttl settings. 72 * Alan Cox : Handle FIN (more) properly (we hope). 73 * Alan Cox : RST frames sent on unsynchronised 74 * state ack error. 75 * Alan Cox : Put in missing check for SYN bit. 76 * Alan Cox : Added tcp_select_window() aka NET2E 77 * window non shrink trick. 78 * Alan Cox : Added a couple of small NET2E timer 79 * fixes 80 * Charles Hedrick : TCP fixes 81 * Toomas Tamm : TCP window fixes 82 * Alan Cox : Small URG fix to rlogin ^C ack fight 83 * Charles Hedrick : Rewrote most of it to actually work 84 * Linus : Rewrote tcp_read() and URG handling 85 * completely 86 * Gerhard Koerting: Fixed some missing timer handling 87 * Matthew Dillon : Reworked TCP machine states as per RFC 88 * Gerhard Koerting: PC/TCP workarounds 89 * Adam Caldwell : Assorted timer/timing errors 90 * Matthew Dillon : Fixed another RST bug 91 * Alan Cox : Move to kernel side addressing changes. 92 * Alan Cox : Beginning work on TCP fastpathing 93 * (not yet usable) 94 * Arnt Gulbrandsen: Turbocharged tcp_check() routine. 95 * Alan Cox : TCP fast path debugging 96 * Alan Cox : Window clamping 97 * Michael Riepe : Bug in tcp_check() 98 * Matt Dillon : More TCP improvements and RST bug fixes 99 * Matt Dillon : Yet more small nasties remove from the 100 * TCP code (Be very nice to this man if 101 * tcp finally works 100%) 8) 102 * Alan Cox : BSD accept semantics. 103 * Alan Cox : Reset on closedown bug. 104 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto(). 105 * Michael Pall : Handle poll() after URG properly in 106 * all cases. 107 * Michael Pall : Undo the last fix in tcp_read_urg() 108 * (multi URG PUSH broke rlogin). 109 * Michael Pall : Fix the multi URG PUSH problem in 110 * tcp_readable(), poll() after URG 111 * works now. 112 * Michael Pall : recv(...,MSG_OOB) never blocks in the 113 * BSD api. 114 * Alan Cox : Changed the semantics of sk->socket to 115 * fix a race and a signal problem with 116 * accept() and async I/O. 117 * Alan Cox : Relaxed the rules on tcp_sendto(). 118 * Yury Shevchuk : Really fixed accept() blocking problem. 119 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for 120 * clients/servers which listen in on 121 * fixed ports. 122 * Alan Cox : Cleaned the above up and shrank it to 123 * a sensible code size. 124 * Alan Cox : Self connect lockup fix. 125 * Alan Cox : No connect to multicast. 126 * Ross Biro : Close unaccepted children on master 127 * socket close. 128 * Alan Cox : Reset tracing code. 129 * Alan Cox : Spurious resets on shutdown. 130 * Alan Cox : Giant 15 minute/60 second timer error 131 * Alan Cox : Small whoops in polling before an 132 * accept. 133 * Alan Cox : Kept the state trace facility since 134 * it's handy for debugging. 135 * Alan Cox : More reset handler fixes. 136 * Alan Cox : Started rewriting the code based on 137 * the RFC's for other useful protocol 138 * references see: Comer, KA9Q NOS, and 139 * for a reference on the difference 140 * between specifications and how BSD 141 * works see the 4.4lite source. 142 * A.N.Kuznetsov : Don't time wait on completion of tidy 143 * close. 144 * Linus Torvalds : Fin/Shutdown & copied_seq changes. 145 * Linus Torvalds : Fixed BSD port reuse to work first syn 146 * Alan Cox : Reimplemented timers as per the RFC 147 * and using multiple timers for sanity. 148 * Alan Cox : Small bug fixes, and a lot of new 149 * comments. 150 * Alan Cox : Fixed dual reader crash by locking 151 * the buffers (much like datagram.c) 152 * Alan Cox : Fixed stuck sockets in probe. A probe 153 * now gets fed up of retrying without 154 * (even a no space) answer. 155 * Alan Cox : Extracted closing code better 156 * Alan Cox : Fixed the closing state machine to 157 * resemble the RFC. 158 * Alan Cox : More 'per spec' fixes. 159 * Jorge Cwik : Even faster checksumming. 160 * Alan Cox : tcp_data() doesn't ack illegal PSH 161 * only frames. At least one pc tcp stack 162 * generates them. 163 * Alan Cox : Cache last socket. 164 * Alan Cox : Per route irtt. 165 * Matt Day : poll()->select() match BSD precisely on error 166 * Alan Cox : New buffers 167 * Marc Tamsky : Various sk->prot->retransmits and 168 * sk->retransmits misupdating fixed. 169 * Fixed tcp_write_timeout: stuck close, 170 * and TCP syn retries gets used now. 171 * Mark Yarvis : In tcp_read_wakeup(), don't send an 172 * ack if state is TCP_CLOSED. 173 * Alan Cox : Look up device on a retransmit - routes may 174 * change. Doesn't yet cope with MSS shrink right 175 * but it's a start! 176 * Marc Tamsky : Closing in closing fixes. 177 * Mike Shaver : RFC1122 verifications. 178 * Alan Cox : rcv_saddr errors. 179 * Alan Cox : Block double connect(). 180 * Alan Cox : Small hooks for enSKIP. 181 * Alexey Kuznetsov: Path MTU discovery. 182 * Alan Cox : Support soft errors. 183 * Alan Cox : Fix MTU discovery pathological case 184 * when the remote claims no mtu! 185 * Marc Tamsky : TCP_CLOSE fix. 186 * Colin (G3TNE) : Send a reset on syn ack replies in 187 * window but wrong (fixes NT lpd problems) 188 * Pedro Roque : Better TCP window handling, delayed ack. 189 * Joerg Reuter : No modification of locked buffers in 190 * tcp_do_retransmit() 191 * Eric Schenk : Changed receiver side silly window 192 * avoidance algorithm to BSD style 193 * algorithm. This doubles throughput 194 * against machines running Solaris, 195 * and seems to result in general 196 * improvement. 197 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD 198 * Willy Konynenberg : Transparent proxying support. 199 * Mike McLagan : Routing by source 200 * Keith Owens : Do proper merging with partial SKB's in 201 * tcp_do_sendmsg to avoid burstiness. 202 * Eric Schenk : Fix fast close down bug with 203 * shutdown() followed by close(). 204 * Andi Kleen : Make poll agree with SIGIO 205 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and 206 * lingertime == 0 (RFC 793 ABORT Call) 207 * Hirokazu Takahashi : Use copy_from_user() instead of 208 * csum_and_copy_from_user() if possible. 209 * 210 * This program is free software; you can redistribute it and/or 211 * modify it under the terms of the GNU General Public License 212 * as published by the Free Software Foundation; either version 213 * 2 of the License, or(at your option) any later version. 214 * 215 * Description of States: 216 * 217 * TCP_SYN_SENT sent a connection request, waiting for ack 218 * 219 * TCP_SYN_RECV received a connection request, sent ack, 220 * waiting for final ack in three-way handshake. 221 * 222 * TCP_ESTABLISHED connection established 223 * 224 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete 225 * transmission of remaining buffered data 226 * 227 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote 228 * to shutdown 229 * 230 * TCP_CLOSING both sides have shutdown but we still have 231 * data we have to finish sending 232 * 233 * TCP_TIME_WAIT timeout to catch resent junk before entering 234 * closed, can only be entered from FIN_WAIT2 235 * or CLOSING. Required because the other end 236 * may not have gotten our last ACK causing it 237 * to retransmit the data packet (which we ignore) 238 * 239 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for 240 * us to finish writing our data and to shutdown 241 * (we have to close() to move on to LAST_ACK) 242 * 243 * TCP_LAST_ACK out side has shutdown after remote has 244 * shutdown. There may still be data in our 245 * buffer that we have to finish sending 246 * 247 * TCP_CLOSE socket is finished 248 */ 249 250 #include <linux/kernel.h> 251 #include <linux/module.h> 252 #include <linux/types.h> 253 #include <linux/fcntl.h> 254 #include <linux/poll.h> 255 #include <linux/init.h> 256 #include <linux/fs.h> 257 #include <linux/skbuff.h> 258 #include <linux/splice.h> 259 #include <linux/net.h> 260 #include <linux/socket.h> 261 #include <linux/random.h> 262 #include <linux/bootmem.h> 263 #include <linux/cache.h> 264 #include <linux/err.h> 265 #include <linux/crypto.h> 266 267 #include <net/icmp.h> 268 #include <net/tcp.h> 269 #include <net/xfrm.h> 270 #include <net/ip.h> 271 #include <net/netdma.h> 272 #include <net/sock.h> 273 274 #include <asm/uaccess.h> 275 #include <asm/ioctls.h> 276 277 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; 278 279 DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics) __read_mostly; 280 281 atomic_t tcp_orphan_count = ATOMIC_INIT(0); 282 283 EXPORT_SYMBOL_GPL(tcp_orphan_count); 284 285 int sysctl_tcp_mem[3] __read_mostly; 286 int sysctl_tcp_wmem[3] __read_mostly; 287 int sysctl_tcp_rmem[3] __read_mostly; 288 289 EXPORT_SYMBOL(sysctl_tcp_mem); 290 EXPORT_SYMBOL(sysctl_tcp_rmem); 291 EXPORT_SYMBOL(sysctl_tcp_wmem); 292 293 atomic_t tcp_memory_allocated; /* Current allocated memory. */ 294 atomic_t tcp_sockets_allocated; /* Current number of TCP sockets. */ 295 296 EXPORT_SYMBOL(tcp_memory_allocated); 297 EXPORT_SYMBOL(tcp_sockets_allocated); 298 299 /* 300 * TCP splice context 301 */ 302 struct tcp_splice_state { 303 struct pipe_inode_info *pipe; 304 size_t len; 305 unsigned int flags; 306 }; 307 308 /* 309 * Pressure flag: try to collapse. 310 * Technical note: it is used by multiple contexts non atomically. 311 * All the __sk_mem_schedule() is of this nature: accounting 312 * is strict, actions are advisory and have some latency. 313 */ 314 int tcp_memory_pressure __read_mostly; 315 316 EXPORT_SYMBOL(tcp_memory_pressure); 317 318 void tcp_enter_memory_pressure(void) 319 { 320 if (!tcp_memory_pressure) { 321 NET_INC_STATS(LINUX_MIB_TCPMEMORYPRESSURES); 322 tcp_memory_pressure = 1; 323 } 324 } 325 326 EXPORT_SYMBOL(tcp_enter_memory_pressure); 327 328 /* 329 * Wait for a TCP event. 330 * 331 * Note that we don't need to lock the socket, as the upper poll layers 332 * take care of normal races (between the test and the event) and we don't 333 * go look at any of the socket buffers directly. 334 */ 335 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 336 { 337 unsigned int mask; 338 struct sock *sk = sock->sk; 339 struct tcp_sock *tp = tcp_sk(sk); 340 341 poll_wait(file, sk->sk_sleep, wait); 342 if (sk->sk_state == TCP_LISTEN) 343 return inet_csk_listen_poll(sk); 344 345 /* Socket is not locked. We are protected from async events 346 by poll logic and correct handling of state changes 347 made by another threads is impossible in any case. 348 */ 349 350 mask = 0; 351 if (sk->sk_err) 352 mask = POLLERR; 353 354 /* 355 * POLLHUP is certainly not done right. But poll() doesn't 356 * have a notion of HUP in just one direction, and for a 357 * socket the read side is more interesting. 358 * 359 * Some poll() documentation says that POLLHUP is incompatible 360 * with the POLLOUT/POLLWR flags, so somebody should check this 361 * all. But careful, it tends to be safer to return too many 362 * bits than too few, and you can easily break real applications 363 * if you don't tell them that something has hung up! 364 * 365 * Check-me. 366 * 367 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and 368 * our fs/select.c). It means that after we received EOF, 369 * poll always returns immediately, making impossible poll() on write() 370 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP 371 * if and only if shutdown has been made in both directions. 372 * Actually, it is interesting to look how Solaris and DUX 373 * solve this dilemma. I would prefer, if PULLHUP were maskable, 374 * then we could set it on SND_SHUTDOWN. BTW examples given 375 * in Stevens' books assume exactly this behaviour, it explains 376 * why PULLHUP is incompatible with POLLOUT. --ANK 377 * 378 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 379 * blocking on fresh not-connected or disconnected socket. --ANK 380 */ 381 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) 382 mask |= POLLHUP; 383 if (sk->sk_shutdown & RCV_SHUTDOWN) 384 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 385 386 /* Connected? */ 387 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { 388 /* Potential race condition. If read of tp below will 389 * escape above sk->sk_state, we can be illegally awaken 390 * in SYN_* states. */ 391 if ((tp->rcv_nxt != tp->copied_seq) && 392 (tp->urg_seq != tp->copied_seq || 393 tp->rcv_nxt != tp->copied_seq + 1 || 394 sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data)) 395 mask |= POLLIN | POLLRDNORM; 396 397 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 398 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 399 mask |= POLLOUT | POLLWRNORM; 400 } else { /* send SIGIO later */ 401 set_bit(SOCK_ASYNC_NOSPACE, 402 &sk->sk_socket->flags); 403 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 404 405 /* Race breaker. If space is freed after 406 * wspace test but before the flags are set, 407 * IO signal will be lost. 408 */ 409 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) 410 mask |= POLLOUT | POLLWRNORM; 411 } 412 } 413 414 if (tp->urg_data & TCP_URG_VALID) 415 mask |= POLLPRI; 416 } 417 return mask; 418 } 419 420 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 421 { 422 struct tcp_sock *tp = tcp_sk(sk); 423 int answ; 424 425 switch (cmd) { 426 case SIOCINQ: 427 if (sk->sk_state == TCP_LISTEN) 428 return -EINVAL; 429 430 lock_sock(sk); 431 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 432 answ = 0; 433 else if (sock_flag(sk, SOCK_URGINLINE) || 434 !tp->urg_data || 435 before(tp->urg_seq, tp->copied_seq) || 436 !before(tp->urg_seq, tp->rcv_nxt)) { 437 answ = tp->rcv_nxt - tp->copied_seq; 438 439 /* Subtract 1, if FIN is in queue. */ 440 if (answ && !skb_queue_empty(&sk->sk_receive_queue)) 441 answ -= 442 tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin; 443 } else 444 answ = tp->urg_seq - tp->copied_seq; 445 release_sock(sk); 446 break; 447 case SIOCATMARK: 448 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 449 break; 450 case SIOCOUTQ: 451 if (sk->sk_state == TCP_LISTEN) 452 return -EINVAL; 453 454 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 455 answ = 0; 456 else 457 answ = tp->write_seq - tp->snd_una; 458 break; 459 default: 460 return -ENOIOCTLCMD; 461 } 462 463 return put_user(answ, (int __user *)arg); 464 } 465 466 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 467 { 468 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH; 469 tp->pushed_seq = tp->write_seq; 470 } 471 472 static inline int forced_push(struct tcp_sock *tp) 473 { 474 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 475 } 476 477 static inline void skb_entail(struct sock *sk, struct sk_buff *skb) 478 { 479 struct tcp_sock *tp = tcp_sk(sk); 480 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 481 482 skb->csum = 0; 483 tcb->seq = tcb->end_seq = tp->write_seq; 484 tcb->flags = TCPCB_FLAG_ACK; 485 tcb->sacked = 0; 486 skb_header_release(skb); 487 tcp_add_write_queue_tail(sk, skb); 488 sk->sk_wmem_queued += skb->truesize; 489 sk_mem_charge(sk, skb->truesize); 490 if (tp->nonagle & TCP_NAGLE_PUSH) 491 tp->nonagle &= ~TCP_NAGLE_PUSH; 492 } 493 494 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags, 495 struct sk_buff *skb) 496 { 497 if (flags & MSG_OOB) { 498 tp->urg_mode = 1; 499 tp->snd_up = tp->write_seq; 500 } 501 } 502 503 static inline void tcp_push(struct sock *sk, int flags, int mss_now, 504 int nonagle) 505 { 506 struct tcp_sock *tp = tcp_sk(sk); 507 508 if (tcp_send_head(sk)) { 509 struct sk_buff *skb = tcp_write_queue_tail(sk); 510 if (!(flags & MSG_MORE) || forced_push(tp)) 511 tcp_mark_push(tp, skb); 512 tcp_mark_urg(tp, flags, skb); 513 __tcp_push_pending_frames(sk, mss_now, 514 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); 515 } 516 } 517 518 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 519 unsigned int offset, size_t len) 520 { 521 struct tcp_splice_state *tss = rd_desc->arg.data; 522 523 return skb_splice_bits(skb, offset, tss->pipe, tss->len, tss->flags); 524 } 525 526 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 527 { 528 /* Store TCP splice context information in read_descriptor_t. */ 529 read_descriptor_t rd_desc = { 530 .arg.data = tss, 531 }; 532 533 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 534 } 535 536 /** 537 * tcp_splice_read - splice data from TCP socket to a pipe 538 * @sock: socket to splice from 539 * @ppos: position (not valid) 540 * @pipe: pipe to splice to 541 * @len: number of bytes to splice 542 * @flags: splice modifier flags 543 * 544 * Description: 545 * Will read pages from given socket and fill them into a pipe. 546 * 547 **/ 548 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 549 struct pipe_inode_info *pipe, size_t len, 550 unsigned int flags) 551 { 552 struct sock *sk = sock->sk; 553 struct tcp_splice_state tss = { 554 .pipe = pipe, 555 .len = len, 556 .flags = flags, 557 }; 558 long timeo; 559 ssize_t spliced; 560 int ret; 561 562 /* 563 * We can't seek on a socket input 564 */ 565 if (unlikely(*ppos)) 566 return -ESPIPE; 567 568 ret = spliced = 0; 569 570 lock_sock(sk); 571 572 timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK); 573 while (tss.len) { 574 ret = __tcp_splice_read(sk, &tss); 575 if (ret < 0) 576 break; 577 else if (!ret) { 578 if (spliced) 579 break; 580 if (flags & SPLICE_F_NONBLOCK) { 581 ret = -EAGAIN; 582 break; 583 } 584 if (sock_flag(sk, SOCK_DONE)) 585 break; 586 if (sk->sk_err) { 587 ret = sock_error(sk); 588 break; 589 } 590 if (sk->sk_shutdown & RCV_SHUTDOWN) 591 break; 592 if (sk->sk_state == TCP_CLOSE) { 593 /* 594 * This occurs when user tries to read 595 * from never connected socket. 596 */ 597 if (!sock_flag(sk, SOCK_DONE)) 598 ret = -ENOTCONN; 599 break; 600 } 601 if (!timeo) { 602 ret = -EAGAIN; 603 break; 604 } 605 sk_wait_data(sk, &timeo); 606 if (signal_pending(current)) { 607 ret = sock_intr_errno(timeo); 608 break; 609 } 610 continue; 611 } 612 tss.len -= ret; 613 spliced += ret; 614 615 release_sock(sk); 616 lock_sock(sk); 617 618 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 619 (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo || 620 signal_pending(current)) 621 break; 622 } 623 624 release_sock(sk); 625 626 if (spliced) 627 return spliced; 628 629 return ret; 630 } 631 632 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) 633 { 634 struct sk_buff *skb; 635 636 /* The TCP header must be at least 32-bit aligned. */ 637 size = ALIGN(size, 4); 638 639 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 640 if (skb) { 641 if (sk_wmem_schedule(sk, skb->truesize)) { 642 /* 643 * Make sure that we have exactly size bytes 644 * available to the caller, no more, no less. 645 */ 646 skb_reserve(skb, skb_tailroom(skb) - size); 647 return skb; 648 } 649 __kfree_skb(skb); 650 } else { 651 sk->sk_prot->enter_memory_pressure(); 652 sk_stream_moderate_sndbuf(sk); 653 } 654 return NULL; 655 } 656 657 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, 658 size_t psize, int flags) 659 { 660 struct tcp_sock *tp = tcp_sk(sk); 661 int mss_now, size_goal; 662 int err; 663 ssize_t copied; 664 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 665 666 /* Wait for a connection to finish. */ 667 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 668 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 669 goto out_err; 670 671 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 672 673 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); 674 size_goal = tp->xmit_size_goal; 675 copied = 0; 676 677 err = -EPIPE; 678 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 679 goto do_error; 680 681 while (psize > 0) { 682 struct sk_buff *skb = tcp_write_queue_tail(sk); 683 struct page *page = pages[poffset / PAGE_SIZE]; 684 int copy, i, can_coalesce; 685 int offset = poffset % PAGE_SIZE; 686 int size = min_t(size_t, psize, PAGE_SIZE - offset); 687 688 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { 689 new_segment: 690 if (!sk_stream_memory_free(sk)) 691 goto wait_for_sndbuf; 692 693 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); 694 if (!skb) 695 goto wait_for_memory; 696 697 skb_entail(sk, skb); 698 copy = size_goal; 699 } 700 701 if (copy > size) 702 copy = size; 703 704 i = skb_shinfo(skb)->nr_frags; 705 can_coalesce = skb_can_coalesce(skb, i, page, offset); 706 if (!can_coalesce && i >= MAX_SKB_FRAGS) { 707 tcp_mark_push(tp, skb); 708 goto new_segment; 709 } 710 if (!sk_wmem_schedule(sk, copy)) 711 goto wait_for_memory; 712 713 if (can_coalesce) { 714 skb_shinfo(skb)->frags[i - 1].size += copy; 715 } else { 716 get_page(page); 717 skb_fill_page_desc(skb, i, page, offset, copy); 718 } 719 720 skb->len += copy; 721 skb->data_len += copy; 722 skb->truesize += copy; 723 sk->sk_wmem_queued += copy; 724 sk_mem_charge(sk, copy); 725 skb->ip_summed = CHECKSUM_PARTIAL; 726 tp->write_seq += copy; 727 TCP_SKB_CB(skb)->end_seq += copy; 728 skb_shinfo(skb)->gso_segs = 0; 729 730 if (!copied) 731 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 732 733 copied += copy; 734 poffset += copy; 735 if (!(psize -= copy)) 736 goto out; 737 738 if (skb->len < size_goal || (flags & MSG_OOB)) 739 continue; 740 741 if (forced_push(tp)) { 742 tcp_mark_push(tp, skb); 743 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 744 } else if (skb == tcp_send_head(sk)) 745 tcp_push_one(sk, mss_now); 746 continue; 747 748 wait_for_sndbuf: 749 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 750 wait_for_memory: 751 if (copied) 752 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 753 754 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 755 goto do_error; 756 757 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); 758 size_goal = tp->xmit_size_goal; 759 } 760 761 out: 762 if (copied) 763 tcp_push(sk, flags, mss_now, tp->nonagle); 764 return copied; 765 766 do_error: 767 if (copied) 768 goto out; 769 out_err: 770 return sk_stream_error(sk, flags, err); 771 } 772 773 ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, 774 size_t size, int flags) 775 { 776 ssize_t res; 777 struct sock *sk = sock->sk; 778 779 if (!(sk->sk_route_caps & NETIF_F_SG) || 780 !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) 781 return sock_no_sendpage(sock, page, offset, size, flags); 782 783 lock_sock(sk); 784 TCP_CHECK_TIMER(sk); 785 res = do_tcp_sendpages(sk, &page, offset, size, flags); 786 TCP_CHECK_TIMER(sk); 787 release_sock(sk); 788 return res; 789 } 790 791 #define TCP_PAGE(sk) (sk->sk_sndmsg_page) 792 #define TCP_OFF(sk) (sk->sk_sndmsg_off) 793 794 static inline int select_size(struct sock *sk) 795 { 796 struct tcp_sock *tp = tcp_sk(sk); 797 int tmp = tp->mss_cache; 798 799 if (sk->sk_route_caps & NETIF_F_SG) { 800 if (sk_can_gso(sk)) 801 tmp = 0; 802 else { 803 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); 804 805 if (tmp >= pgbreak && 806 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) 807 tmp = pgbreak; 808 } 809 } 810 811 return tmp; 812 } 813 814 int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, 815 size_t size) 816 { 817 struct sock *sk = sock->sk; 818 struct iovec *iov; 819 struct tcp_sock *tp = tcp_sk(sk); 820 struct sk_buff *skb; 821 int iovlen, flags; 822 int mss_now, size_goal; 823 int err, copied; 824 long timeo; 825 826 lock_sock(sk); 827 TCP_CHECK_TIMER(sk); 828 829 flags = msg->msg_flags; 830 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 831 832 /* Wait for a connection to finish. */ 833 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 834 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 835 goto out_err; 836 837 /* This should be in poll */ 838 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 839 840 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); 841 size_goal = tp->xmit_size_goal; 842 843 /* Ok commence sending. */ 844 iovlen = msg->msg_iovlen; 845 iov = msg->msg_iov; 846 copied = 0; 847 848 err = -EPIPE; 849 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 850 goto do_error; 851 852 while (--iovlen >= 0) { 853 int seglen = iov->iov_len; 854 unsigned char __user *from = iov->iov_base; 855 856 iov++; 857 858 while (seglen > 0) { 859 int copy; 860 861 skb = tcp_write_queue_tail(sk); 862 863 if (!tcp_send_head(sk) || 864 (copy = size_goal - skb->len) <= 0) { 865 866 new_segment: 867 /* Allocate new segment. If the interface is SG, 868 * allocate skb fitting to single page. 869 */ 870 if (!sk_stream_memory_free(sk)) 871 goto wait_for_sndbuf; 872 873 skb = sk_stream_alloc_skb(sk, select_size(sk), 874 sk->sk_allocation); 875 if (!skb) 876 goto wait_for_memory; 877 878 /* 879 * Check whether we can use HW checksum. 880 */ 881 if (sk->sk_route_caps & NETIF_F_ALL_CSUM) 882 skb->ip_summed = CHECKSUM_PARTIAL; 883 884 skb_entail(sk, skb); 885 copy = size_goal; 886 } 887 888 /* Try to append data to the end of skb. */ 889 if (copy > seglen) 890 copy = seglen; 891 892 /* Where to copy to? */ 893 if (skb_tailroom(skb) > 0) { 894 /* We have some space in skb head. Superb! */ 895 if (copy > skb_tailroom(skb)) 896 copy = skb_tailroom(skb); 897 if ((err = skb_add_data(skb, from, copy)) != 0) 898 goto do_fault; 899 } else { 900 int merge = 0; 901 int i = skb_shinfo(skb)->nr_frags; 902 struct page *page = TCP_PAGE(sk); 903 int off = TCP_OFF(sk); 904 905 if (skb_can_coalesce(skb, i, page, off) && 906 off != PAGE_SIZE) { 907 /* We can extend the last page 908 * fragment. */ 909 merge = 1; 910 } else if (i == MAX_SKB_FRAGS || 911 (!i && 912 !(sk->sk_route_caps & NETIF_F_SG))) { 913 /* Need to add new fragment and cannot 914 * do this because interface is non-SG, 915 * or because all the page slots are 916 * busy. */ 917 tcp_mark_push(tp, skb); 918 goto new_segment; 919 } else if (page) { 920 if (off == PAGE_SIZE) { 921 put_page(page); 922 TCP_PAGE(sk) = page = NULL; 923 off = 0; 924 } 925 } else 926 off = 0; 927 928 if (copy > PAGE_SIZE - off) 929 copy = PAGE_SIZE - off; 930 931 if (!sk_wmem_schedule(sk, copy)) 932 goto wait_for_memory; 933 934 if (!page) { 935 /* Allocate new cache page. */ 936 if (!(page = sk_stream_alloc_page(sk))) 937 goto wait_for_memory; 938 } 939 940 /* Time to copy data. We are close to 941 * the end! */ 942 err = skb_copy_to_page(sk, from, skb, page, 943 off, copy); 944 if (err) { 945 /* If this page was new, give it to the 946 * socket so it does not get leaked. 947 */ 948 if (!TCP_PAGE(sk)) { 949 TCP_PAGE(sk) = page; 950 TCP_OFF(sk) = 0; 951 } 952 goto do_error; 953 } 954 955 /* Update the skb. */ 956 if (merge) { 957 skb_shinfo(skb)->frags[i - 1].size += 958 copy; 959 } else { 960 skb_fill_page_desc(skb, i, page, off, copy); 961 if (TCP_PAGE(sk)) { 962 get_page(page); 963 } else if (off + copy < PAGE_SIZE) { 964 get_page(page); 965 TCP_PAGE(sk) = page; 966 } 967 } 968 969 TCP_OFF(sk) = off + copy; 970 } 971 972 if (!copied) 973 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 974 975 tp->write_seq += copy; 976 TCP_SKB_CB(skb)->end_seq += copy; 977 skb_shinfo(skb)->gso_segs = 0; 978 979 from += copy; 980 copied += copy; 981 if ((seglen -= copy) == 0 && iovlen == 0) 982 goto out; 983 984 if (skb->len < size_goal || (flags & MSG_OOB)) 985 continue; 986 987 if (forced_push(tp)) { 988 tcp_mark_push(tp, skb); 989 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 990 } else if (skb == tcp_send_head(sk)) 991 tcp_push_one(sk, mss_now); 992 continue; 993 994 wait_for_sndbuf: 995 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 996 wait_for_memory: 997 if (copied) 998 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 999 1000 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 1001 goto do_error; 1002 1003 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); 1004 size_goal = tp->xmit_size_goal; 1005 } 1006 } 1007 1008 out: 1009 if (copied) 1010 tcp_push(sk, flags, mss_now, tp->nonagle); 1011 TCP_CHECK_TIMER(sk); 1012 release_sock(sk); 1013 return copied; 1014 1015 do_fault: 1016 if (!skb->len) { 1017 tcp_unlink_write_queue(skb, sk); 1018 /* It is the one place in all of TCP, except connection 1019 * reset, where we can be unlinking the send_head. 1020 */ 1021 tcp_check_send_head(sk, skb); 1022 sk_wmem_free_skb(sk, skb); 1023 } 1024 1025 do_error: 1026 if (copied) 1027 goto out; 1028 out_err: 1029 err = sk_stream_error(sk, flags, err); 1030 TCP_CHECK_TIMER(sk); 1031 release_sock(sk); 1032 return err; 1033 } 1034 1035 /* 1036 * Handle reading urgent data. BSD has very simple semantics for 1037 * this, no blocking and very strange errors 8) 1038 */ 1039 1040 static int tcp_recv_urg(struct sock *sk, long timeo, 1041 struct msghdr *msg, int len, int flags, 1042 int *addr_len) 1043 { 1044 struct tcp_sock *tp = tcp_sk(sk); 1045 1046 /* No URG data to read. */ 1047 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1048 tp->urg_data == TCP_URG_READ) 1049 return -EINVAL; /* Yes this is right ! */ 1050 1051 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1052 return -ENOTCONN; 1053 1054 if (tp->urg_data & TCP_URG_VALID) { 1055 int err = 0; 1056 char c = tp->urg_data; 1057 1058 if (!(flags & MSG_PEEK)) 1059 tp->urg_data = TCP_URG_READ; 1060 1061 /* Read urgent data. */ 1062 msg->msg_flags |= MSG_OOB; 1063 1064 if (len > 0) { 1065 if (!(flags & MSG_TRUNC)) 1066 err = memcpy_toiovec(msg->msg_iov, &c, 1); 1067 len = 1; 1068 } else 1069 msg->msg_flags |= MSG_TRUNC; 1070 1071 return err ? -EFAULT : len; 1072 } 1073 1074 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1075 return 0; 1076 1077 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1078 * the available implementations agree in this case: 1079 * this call should never block, independent of the 1080 * blocking state of the socket. 1081 * Mike <pall@rz.uni-karlsruhe.de> 1082 */ 1083 return -EAGAIN; 1084 } 1085 1086 /* Clean up the receive buffer for full frames taken by the user, 1087 * then send an ACK if necessary. COPIED is the number of bytes 1088 * tcp_recvmsg has given to the user so far, it speeds up the 1089 * calculation of whether or not we must ACK for the sake of 1090 * a window update. 1091 */ 1092 void tcp_cleanup_rbuf(struct sock *sk, int copied) 1093 { 1094 struct tcp_sock *tp = tcp_sk(sk); 1095 int time_to_ack = 0; 1096 1097 #if TCP_DEBUG 1098 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1099 1100 BUG_TRAP(!skb || before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq)); 1101 #endif 1102 1103 if (inet_csk_ack_scheduled(sk)) { 1104 const struct inet_connection_sock *icsk = inet_csk(sk); 1105 /* Delayed ACKs frequently hit locked sockets during bulk 1106 * receive. */ 1107 if (icsk->icsk_ack.blocked || 1108 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1109 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1110 /* 1111 * If this read emptied read buffer, we send ACK, if 1112 * connection is not bidirectional, user drained 1113 * receive buffer and there was a small segment 1114 * in queue. 1115 */ 1116 (copied > 0 && 1117 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1118 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1119 !icsk->icsk_ack.pingpong)) && 1120 !atomic_read(&sk->sk_rmem_alloc))) 1121 time_to_ack = 1; 1122 } 1123 1124 /* We send an ACK if we can now advertise a non-zero window 1125 * which has been raised "significantly". 1126 * 1127 * Even if window raised up to infinity, do not send window open ACK 1128 * in states, where we will not receive more. It is useless. 1129 */ 1130 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1131 __u32 rcv_window_now = tcp_receive_window(tp); 1132 1133 /* Optimize, __tcp_select_window() is not cheap. */ 1134 if (2*rcv_window_now <= tp->window_clamp) { 1135 __u32 new_window = __tcp_select_window(sk); 1136 1137 /* Send ACK now, if this read freed lots of space 1138 * in our buffer. Certainly, new_window is new window. 1139 * We can advertise it now, if it is not less than current one. 1140 * "Lots" means "at least twice" here. 1141 */ 1142 if (new_window && new_window >= 2 * rcv_window_now) 1143 time_to_ack = 1; 1144 } 1145 } 1146 if (time_to_ack) 1147 tcp_send_ack(sk); 1148 } 1149 1150 static void tcp_prequeue_process(struct sock *sk) 1151 { 1152 struct sk_buff *skb; 1153 struct tcp_sock *tp = tcp_sk(sk); 1154 1155 NET_INC_STATS_USER(LINUX_MIB_TCPPREQUEUED); 1156 1157 /* RX process wants to run with disabled BHs, though it is not 1158 * necessary */ 1159 local_bh_disable(); 1160 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) 1161 sk->sk_backlog_rcv(sk, skb); 1162 local_bh_enable(); 1163 1164 /* Clear memory counter. */ 1165 tp->ucopy.memory = 0; 1166 } 1167 1168 static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1169 { 1170 struct sk_buff *skb; 1171 u32 offset; 1172 1173 skb_queue_walk(&sk->sk_receive_queue, skb) { 1174 offset = seq - TCP_SKB_CB(skb)->seq; 1175 if (tcp_hdr(skb)->syn) 1176 offset--; 1177 if (offset < skb->len || tcp_hdr(skb)->fin) { 1178 *off = offset; 1179 return skb; 1180 } 1181 } 1182 return NULL; 1183 } 1184 1185 /* 1186 * This routine provides an alternative to tcp_recvmsg() for routines 1187 * that would like to handle copying from skbuffs directly in 'sendfile' 1188 * fashion. 1189 * Note: 1190 * - It is assumed that the socket was locked by the caller. 1191 * - The routine does not block. 1192 * - At present, there is no support for reading OOB data 1193 * or for 'peeking' the socket using this routine 1194 * (although both would be easy to implement). 1195 */ 1196 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1197 sk_read_actor_t recv_actor) 1198 { 1199 struct sk_buff *skb; 1200 struct tcp_sock *tp = tcp_sk(sk); 1201 u32 seq = tp->copied_seq; 1202 u32 offset; 1203 int copied = 0; 1204 1205 if (sk->sk_state == TCP_LISTEN) 1206 return -ENOTCONN; 1207 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1208 if (offset < skb->len) { 1209 size_t used, len; 1210 1211 len = skb->len - offset; 1212 /* Stop reading if we hit a patch of urgent data */ 1213 if (tp->urg_data) { 1214 u32 urg_offset = tp->urg_seq - seq; 1215 if (urg_offset < len) 1216 len = urg_offset; 1217 if (!len) 1218 break; 1219 } 1220 used = recv_actor(desc, skb, offset, len); 1221 if (used < 0) { 1222 if (!copied) 1223 copied = used; 1224 break; 1225 } else if (used <= len) { 1226 seq += used; 1227 copied += used; 1228 offset += used; 1229 } 1230 if (offset != skb->len) 1231 break; 1232 } 1233 if (tcp_hdr(skb)->fin) { 1234 sk_eat_skb(sk, skb, 0); 1235 ++seq; 1236 break; 1237 } 1238 sk_eat_skb(sk, skb, 0); 1239 if (!desc->count) 1240 break; 1241 } 1242 tp->copied_seq = seq; 1243 1244 tcp_rcv_space_adjust(sk); 1245 1246 /* Clean up data we have read: This will do ACK frames. */ 1247 if (copied > 0) 1248 tcp_cleanup_rbuf(sk, copied); 1249 return copied; 1250 } 1251 1252 /* 1253 * This routine copies from a sock struct into the user buffer. 1254 * 1255 * Technical note: in 2.3 we work on _locked_ socket, so that 1256 * tricks with *seq access order and skb->users are not required. 1257 * Probably, code can be easily improved even more. 1258 */ 1259 1260 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1261 size_t len, int nonblock, int flags, int *addr_len) 1262 { 1263 struct tcp_sock *tp = tcp_sk(sk); 1264 int copied = 0; 1265 u32 peek_seq; 1266 u32 *seq; 1267 unsigned long used; 1268 int err; 1269 int target; /* Read at least this many bytes */ 1270 long timeo; 1271 struct task_struct *user_recv = NULL; 1272 int copied_early = 0; 1273 struct sk_buff *skb; 1274 1275 lock_sock(sk); 1276 1277 TCP_CHECK_TIMER(sk); 1278 1279 err = -ENOTCONN; 1280 if (sk->sk_state == TCP_LISTEN) 1281 goto out; 1282 1283 timeo = sock_rcvtimeo(sk, nonblock); 1284 1285 /* Urgent data needs to be handled specially. */ 1286 if (flags & MSG_OOB) 1287 goto recv_urg; 1288 1289 seq = &tp->copied_seq; 1290 if (flags & MSG_PEEK) { 1291 peek_seq = tp->copied_seq; 1292 seq = &peek_seq; 1293 } 1294 1295 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1296 1297 #ifdef CONFIG_NET_DMA 1298 tp->ucopy.dma_chan = NULL; 1299 preempt_disable(); 1300 skb = skb_peek_tail(&sk->sk_receive_queue); 1301 { 1302 int available = 0; 1303 1304 if (skb) 1305 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); 1306 if ((available < target) && 1307 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && 1308 !sysctl_tcp_low_latency && 1309 __get_cpu_var(softnet_data).net_dma) { 1310 preempt_enable_no_resched(); 1311 tp->ucopy.pinned_list = 1312 dma_pin_iovec_pages(msg->msg_iov, len); 1313 } else { 1314 preempt_enable_no_resched(); 1315 } 1316 } 1317 #endif 1318 1319 do { 1320 u32 offset; 1321 1322 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1323 if (tp->urg_data && tp->urg_seq == *seq) { 1324 if (copied) 1325 break; 1326 if (signal_pending(current)) { 1327 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1328 break; 1329 } 1330 } 1331 1332 /* Next get a buffer. */ 1333 1334 skb = skb_peek(&sk->sk_receive_queue); 1335 do { 1336 if (!skb) 1337 break; 1338 1339 /* Now that we have two receive queues this 1340 * shouldn't happen. 1341 */ 1342 if (before(*seq, TCP_SKB_CB(skb)->seq)) { 1343 printk(KERN_INFO "recvmsg bug: copied %X " 1344 "seq %X\n", *seq, TCP_SKB_CB(skb)->seq); 1345 break; 1346 } 1347 offset = *seq - TCP_SKB_CB(skb)->seq; 1348 if (tcp_hdr(skb)->syn) 1349 offset--; 1350 if (offset < skb->len) 1351 goto found_ok_skb; 1352 if (tcp_hdr(skb)->fin) 1353 goto found_fin_ok; 1354 BUG_TRAP(flags & MSG_PEEK); 1355 skb = skb->next; 1356 } while (skb != (struct sk_buff *)&sk->sk_receive_queue); 1357 1358 /* Well, if we have backlog, try to process it now yet. */ 1359 1360 if (copied >= target && !sk->sk_backlog.tail) 1361 break; 1362 1363 if (copied) { 1364 if (sk->sk_err || 1365 sk->sk_state == TCP_CLOSE || 1366 (sk->sk_shutdown & RCV_SHUTDOWN) || 1367 !timeo || 1368 signal_pending(current) || 1369 (flags & MSG_PEEK)) 1370 break; 1371 } else { 1372 if (sock_flag(sk, SOCK_DONE)) 1373 break; 1374 1375 if (sk->sk_err) { 1376 copied = sock_error(sk); 1377 break; 1378 } 1379 1380 if (sk->sk_shutdown & RCV_SHUTDOWN) 1381 break; 1382 1383 if (sk->sk_state == TCP_CLOSE) { 1384 if (!sock_flag(sk, SOCK_DONE)) { 1385 /* This occurs when user tries to read 1386 * from never connected socket. 1387 */ 1388 copied = -ENOTCONN; 1389 break; 1390 } 1391 break; 1392 } 1393 1394 if (!timeo) { 1395 copied = -EAGAIN; 1396 break; 1397 } 1398 1399 if (signal_pending(current)) { 1400 copied = sock_intr_errno(timeo); 1401 break; 1402 } 1403 } 1404 1405 tcp_cleanup_rbuf(sk, copied); 1406 1407 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { 1408 /* Install new reader */ 1409 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { 1410 user_recv = current; 1411 tp->ucopy.task = user_recv; 1412 tp->ucopy.iov = msg->msg_iov; 1413 } 1414 1415 tp->ucopy.len = len; 1416 1417 BUG_TRAP(tp->copied_seq == tp->rcv_nxt || 1418 (flags & (MSG_PEEK | MSG_TRUNC))); 1419 1420 /* Ugly... If prequeue is not empty, we have to 1421 * process it before releasing socket, otherwise 1422 * order will be broken at second iteration. 1423 * More elegant solution is required!!! 1424 * 1425 * Look: we have the following (pseudo)queues: 1426 * 1427 * 1. packets in flight 1428 * 2. backlog 1429 * 3. prequeue 1430 * 4. receive_queue 1431 * 1432 * Each queue can be processed only if the next ones 1433 * are empty. At this point we have empty receive_queue. 1434 * But prequeue _can_ be not empty after 2nd iteration, 1435 * when we jumped to start of loop because backlog 1436 * processing added something to receive_queue. 1437 * We cannot release_sock(), because backlog contains 1438 * packets arrived _after_ prequeued ones. 1439 * 1440 * Shortly, algorithm is clear --- to process all 1441 * the queues in order. We could make it more directly, 1442 * requeueing packets from backlog to prequeue, if 1443 * is not empty. It is more elegant, but eats cycles, 1444 * unfortunately. 1445 */ 1446 if (!skb_queue_empty(&tp->ucopy.prequeue)) 1447 goto do_prequeue; 1448 1449 /* __ Set realtime policy in scheduler __ */ 1450 } 1451 1452 if (copied >= target) { 1453 /* Do not sleep, just process backlog. */ 1454 release_sock(sk); 1455 lock_sock(sk); 1456 } else 1457 sk_wait_data(sk, &timeo); 1458 1459 #ifdef CONFIG_NET_DMA 1460 tp->ucopy.wakeup = 0; 1461 #endif 1462 1463 if (user_recv) { 1464 int chunk; 1465 1466 /* __ Restore normal policy in scheduler __ */ 1467 1468 if ((chunk = len - tp->ucopy.len) != 0) { 1469 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); 1470 len -= chunk; 1471 copied += chunk; 1472 } 1473 1474 if (tp->rcv_nxt == tp->copied_seq && 1475 !skb_queue_empty(&tp->ucopy.prequeue)) { 1476 do_prequeue: 1477 tcp_prequeue_process(sk); 1478 1479 if ((chunk = len - tp->ucopy.len) != 0) { 1480 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1481 len -= chunk; 1482 copied += chunk; 1483 } 1484 } 1485 } 1486 if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) { 1487 if (net_ratelimit()) 1488 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n", 1489 current->comm, task_pid_nr(current)); 1490 peek_seq = tp->copied_seq; 1491 } 1492 continue; 1493 1494 found_ok_skb: 1495 /* Ok so how much can we use? */ 1496 used = skb->len - offset; 1497 if (len < used) 1498 used = len; 1499 1500 /* Do we have urgent data here? */ 1501 if (tp->urg_data) { 1502 u32 urg_offset = tp->urg_seq - *seq; 1503 if (urg_offset < used) { 1504 if (!urg_offset) { 1505 if (!sock_flag(sk, SOCK_URGINLINE)) { 1506 ++*seq; 1507 offset++; 1508 used--; 1509 if (!used) 1510 goto skip_copy; 1511 } 1512 } else 1513 used = urg_offset; 1514 } 1515 } 1516 1517 if (!(flags & MSG_TRUNC)) { 1518 #ifdef CONFIG_NET_DMA 1519 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1520 tp->ucopy.dma_chan = get_softnet_dma(); 1521 1522 if (tp->ucopy.dma_chan) { 1523 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( 1524 tp->ucopy.dma_chan, skb, offset, 1525 msg->msg_iov, used, 1526 tp->ucopy.pinned_list); 1527 1528 if (tp->ucopy.dma_cookie < 0) { 1529 1530 printk(KERN_ALERT "dma_cookie < 0\n"); 1531 1532 /* Exception. Bailout! */ 1533 if (!copied) 1534 copied = -EFAULT; 1535 break; 1536 } 1537 if ((offset + used) == skb->len) 1538 copied_early = 1; 1539 1540 } else 1541 #endif 1542 { 1543 err = skb_copy_datagram_iovec(skb, offset, 1544 msg->msg_iov, used); 1545 if (err) { 1546 /* Exception. Bailout! */ 1547 if (!copied) 1548 copied = -EFAULT; 1549 break; 1550 } 1551 } 1552 } 1553 1554 *seq += used; 1555 copied += used; 1556 len -= used; 1557 1558 tcp_rcv_space_adjust(sk); 1559 1560 skip_copy: 1561 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1562 tp->urg_data = 0; 1563 tcp_fast_path_check(sk); 1564 } 1565 if (used + offset < skb->len) 1566 continue; 1567 1568 if (tcp_hdr(skb)->fin) 1569 goto found_fin_ok; 1570 if (!(flags & MSG_PEEK)) { 1571 sk_eat_skb(sk, skb, copied_early); 1572 copied_early = 0; 1573 } 1574 continue; 1575 1576 found_fin_ok: 1577 /* Process the FIN. */ 1578 ++*seq; 1579 if (!(flags & MSG_PEEK)) { 1580 sk_eat_skb(sk, skb, copied_early); 1581 copied_early = 0; 1582 } 1583 break; 1584 } while (len > 0); 1585 1586 if (user_recv) { 1587 if (!skb_queue_empty(&tp->ucopy.prequeue)) { 1588 int chunk; 1589 1590 tp->ucopy.len = copied > 0 ? len : 0; 1591 1592 tcp_prequeue_process(sk); 1593 1594 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { 1595 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1596 len -= chunk; 1597 copied += chunk; 1598 } 1599 } 1600 1601 tp->ucopy.task = NULL; 1602 tp->ucopy.len = 0; 1603 } 1604 1605 #ifdef CONFIG_NET_DMA 1606 if (tp->ucopy.dma_chan) { 1607 dma_cookie_t done, used; 1608 1609 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1610 1611 while (dma_async_memcpy_complete(tp->ucopy.dma_chan, 1612 tp->ucopy.dma_cookie, &done, 1613 &used) == DMA_IN_PROGRESS) { 1614 /* do partial cleanup of sk_async_wait_queue */ 1615 while ((skb = skb_peek(&sk->sk_async_wait_queue)) && 1616 (dma_async_is_complete(skb->dma_cookie, done, 1617 used) == DMA_SUCCESS)) { 1618 __skb_dequeue(&sk->sk_async_wait_queue); 1619 kfree_skb(skb); 1620 } 1621 } 1622 1623 /* Safe to free early-copied skbs now */ 1624 __skb_queue_purge(&sk->sk_async_wait_queue); 1625 dma_chan_put(tp->ucopy.dma_chan); 1626 tp->ucopy.dma_chan = NULL; 1627 } 1628 if (tp->ucopy.pinned_list) { 1629 dma_unpin_iovec_pages(tp->ucopy.pinned_list); 1630 tp->ucopy.pinned_list = NULL; 1631 } 1632 #endif 1633 1634 /* According to UNIX98, msg_name/msg_namelen are ignored 1635 * on connected socket. I was just happy when found this 8) --ANK 1636 */ 1637 1638 /* Clean up data we have read: This will do ACK frames. */ 1639 tcp_cleanup_rbuf(sk, copied); 1640 1641 TCP_CHECK_TIMER(sk); 1642 release_sock(sk); 1643 return copied; 1644 1645 out: 1646 TCP_CHECK_TIMER(sk); 1647 release_sock(sk); 1648 return err; 1649 1650 recv_urg: 1651 err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len); 1652 goto out; 1653 } 1654 1655 void tcp_set_state(struct sock *sk, int state) 1656 { 1657 int oldstate = sk->sk_state; 1658 1659 switch (state) { 1660 case TCP_ESTABLISHED: 1661 if (oldstate != TCP_ESTABLISHED) 1662 TCP_INC_STATS(TCP_MIB_CURRESTAB); 1663 break; 1664 1665 case TCP_CLOSE: 1666 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 1667 TCP_INC_STATS(TCP_MIB_ESTABRESETS); 1668 1669 sk->sk_prot->unhash(sk); 1670 if (inet_csk(sk)->icsk_bind_hash && 1671 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1672 inet_put_port(sk); 1673 /* fall through */ 1674 default: 1675 if (oldstate==TCP_ESTABLISHED) 1676 TCP_DEC_STATS(TCP_MIB_CURRESTAB); 1677 } 1678 1679 /* Change state AFTER socket is unhashed to avoid closed 1680 * socket sitting in hash tables. 1681 */ 1682 sk->sk_state = state; 1683 1684 #ifdef STATE_TRACE 1685 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]); 1686 #endif 1687 } 1688 EXPORT_SYMBOL_GPL(tcp_set_state); 1689 1690 /* 1691 * State processing on a close. This implements the state shift for 1692 * sending our FIN frame. Note that we only send a FIN for some 1693 * states. A shutdown() may have already sent the FIN, or we may be 1694 * closed. 1695 */ 1696 1697 static const unsigned char new_state[16] = { 1698 /* current state: new state: action: */ 1699 /* (Invalid) */ TCP_CLOSE, 1700 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1701 /* TCP_SYN_SENT */ TCP_CLOSE, 1702 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1703 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, 1704 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, 1705 /* TCP_TIME_WAIT */ TCP_CLOSE, 1706 /* TCP_CLOSE */ TCP_CLOSE, 1707 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, 1708 /* TCP_LAST_ACK */ TCP_LAST_ACK, 1709 /* TCP_LISTEN */ TCP_CLOSE, 1710 /* TCP_CLOSING */ TCP_CLOSING, 1711 }; 1712 1713 static int tcp_close_state(struct sock *sk) 1714 { 1715 int next = (int)new_state[sk->sk_state]; 1716 int ns = next & TCP_STATE_MASK; 1717 1718 tcp_set_state(sk, ns); 1719 1720 return next & TCP_ACTION_FIN; 1721 } 1722 1723 /* 1724 * Shutdown the sending side of a connection. Much like close except 1725 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 1726 */ 1727 1728 void tcp_shutdown(struct sock *sk, int how) 1729 { 1730 /* We need to grab some memory, and put together a FIN, 1731 * and then put it into the queue to be sent. 1732 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 1733 */ 1734 if (!(how & SEND_SHUTDOWN)) 1735 return; 1736 1737 /* If we've already sent a FIN, or it's a closed state, skip this. */ 1738 if ((1 << sk->sk_state) & 1739 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 1740 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 1741 /* Clear out any half completed packets. FIN if needed. */ 1742 if (tcp_close_state(sk)) 1743 tcp_send_fin(sk); 1744 } 1745 } 1746 1747 void tcp_close(struct sock *sk, long timeout) 1748 { 1749 struct sk_buff *skb; 1750 int data_was_unread = 0; 1751 int state; 1752 1753 lock_sock(sk); 1754 sk->sk_shutdown = SHUTDOWN_MASK; 1755 1756 if (sk->sk_state == TCP_LISTEN) { 1757 tcp_set_state(sk, TCP_CLOSE); 1758 1759 /* Special case. */ 1760 inet_csk_listen_stop(sk); 1761 1762 goto adjudge_to_death; 1763 } 1764 1765 /* We need to flush the recv. buffs. We do this only on the 1766 * descriptor close, not protocol-sourced closes, because the 1767 * reader process may not have drained the data yet! 1768 */ 1769 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1770 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - 1771 tcp_hdr(skb)->fin; 1772 data_was_unread += len; 1773 __kfree_skb(skb); 1774 } 1775 1776 sk_mem_reclaim(sk); 1777 1778 /* As outlined in RFC 2525, section 2.17, we send a RST here because 1779 * data was lost. To witness the awful effects of the old behavior of 1780 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 1781 * GET in an FTP client, suspend the process, wait for the client to 1782 * advertise a zero window, then kill -9 the FTP client, wheee... 1783 * Note: timeout is always zero in such a case. 1784 */ 1785 if (data_was_unread) { 1786 /* Unread data was tossed, zap the connection. */ 1787 NET_INC_STATS_USER(LINUX_MIB_TCPABORTONCLOSE); 1788 tcp_set_state(sk, TCP_CLOSE); 1789 tcp_send_active_reset(sk, GFP_KERNEL); 1790 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1791 /* Check zero linger _after_ checking for unread data. */ 1792 sk->sk_prot->disconnect(sk, 0); 1793 NET_INC_STATS_USER(LINUX_MIB_TCPABORTONDATA); 1794 } else if (tcp_close_state(sk)) { 1795 /* We FIN if the application ate all the data before 1796 * zapping the connection. 1797 */ 1798 1799 /* RED-PEN. Formally speaking, we have broken TCP state 1800 * machine. State transitions: 1801 * 1802 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 1803 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 1804 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 1805 * 1806 * are legal only when FIN has been sent (i.e. in window), 1807 * rather than queued out of window. Purists blame. 1808 * 1809 * F.e. "RFC state" is ESTABLISHED, 1810 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 1811 * 1812 * The visible declinations are that sometimes 1813 * we enter time-wait state, when it is not required really 1814 * (harmless), do not send active resets, when they are 1815 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 1816 * they look as CLOSING or LAST_ACK for Linux) 1817 * Probably, I missed some more holelets. 1818 * --ANK 1819 */ 1820 tcp_send_fin(sk); 1821 } 1822 1823 sk_stream_wait_close(sk, timeout); 1824 1825 adjudge_to_death: 1826 state = sk->sk_state; 1827 sock_hold(sk); 1828 sock_orphan(sk); 1829 atomic_inc(sk->sk_prot->orphan_count); 1830 1831 /* It is the last release_sock in its life. It will remove backlog. */ 1832 release_sock(sk); 1833 1834 1835 /* Now socket is owned by kernel and we acquire BH lock 1836 to finish close. No need to check for user refs. 1837 */ 1838 local_bh_disable(); 1839 bh_lock_sock(sk); 1840 BUG_TRAP(!sock_owned_by_user(sk)); 1841 1842 /* Have we already been destroyed by a softirq or backlog? */ 1843 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 1844 goto out; 1845 1846 /* This is a (useful) BSD violating of the RFC. There is a 1847 * problem with TCP as specified in that the other end could 1848 * keep a socket open forever with no application left this end. 1849 * We use a 3 minute timeout (about the same as BSD) then kill 1850 * our end. If they send after that then tough - BUT: long enough 1851 * that we won't make the old 4*rto = almost no time - whoops 1852 * reset mistake. 1853 * 1854 * Nope, it was not mistake. It is really desired behaviour 1855 * f.e. on http servers, when such sockets are useless, but 1856 * consume significant resources. Let's do it with special 1857 * linger2 option. --ANK 1858 */ 1859 1860 if (sk->sk_state == TCP_FIN_WAIT2) { 1861 struct tcp_sock *tp = tcp_sk(sk); 1862 if (tp->linger2 < 0) { 1863 tcp_set_state(sk, TCP_CLOSE); 1864 tcp_send_active_reset(sk, GFP_ATOMIC); 1865 NET_INC_STATS_BH(LINUX_MIB_TCPABORTONLINGER); 1866 } else { 1867 const int tmo = tcp_fin_time(sk); 1868 1869 if (tmo > TCP_TIMEWAIT_LEN) { 1870 inet_csk_reset_keepalive_timer(sk, 1871 tmo - TCP_TIMEWAIT_LEN); 1872 } else { 1873 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 1874 goto out; 1875 } 1876 } 1877 } 1878 if (sk->sk_state != TCP_CLOSE) { 1879 sk_mem_reclaim(sk); 1880 if (tcp_too_many_orphans(sk, 1881 atomic_read(sk->sk_prot->orphan_count))) { 1882 if (net_ratelimit()) 1883 printk(KERN_INFO "TCP: too many of orphaned " 1884 "sockets\n"); 1885 tcp_set_state(sk, TCP_CLOSE); 1886 tcp_send_active_reset(sk, GFP_ATOMIC); 1887 NET_INC_STATS_BH(LINUX_MIB_TCPABORTONMEMORY); 1888 } 1889 } 1890 1891 if (sk->sk_state == TCP_CLOSE) 1892 inet_csk_destroy_sock(sk); 1893 /* Otherwise, socket is reprieved until protocol close. */ 1894 1895 out: 1896 bh_unlock_sock(sk); 1897 local_bh_enable(); 1898 sock_put(sk); 1899 } 1900 1901 /* These states need RST on ABORT according to RFC793 */ 1902 1903 static inline int tcp_need_reset(int state) 1904 { 1905 return (1 << state) & 1906 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 1907 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 1908 } 1909 1910 int tcp_disconnect(struct sock *sk, int flags) 1911 { 1912 struct inet_sock *inet = inet_sk(sk); 1913 struct inet_connection_sock *icsk = inet_csk(sk); 1914 struct tcp_sock *tp = tcp_sk(sk); 1915 int err = 0; 1916 int old_state = sk->sk_state; 1917 1918 if (old_state != TCP_CLOSE) 1919 tcp_set_state(sk, TCP_CLOSE); 1920 1921 /* ABORT function of RFC793 */ 1922 if (old_state == TCP_LISTEN) { 1923 inet_csk_listen_stop(sk); 1924 } else if (tcp_need_reset(old_state) || 1925 (tp->snd_nxt != tp->write_seq && 1926 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 1927 /* The last check adjusts for discrepancy of Linux wrt. RFC 1928 * states 1929 */ 1930 tcp_send_active_reset(sk, gfp_any()); 1931 sk->sk_err = ECONNRESET; 1932 } else if (old_state == TCP_SYN_SENT) 1933 sk->sk_err = ECONNRESET; 1934 1935 tcp_clear_xmit_timers(sk); 1936 __skb_queue_purge(&sk->sk_receive_queue); 1937 tcp_write_queue_purge(sk); 1938 __skb_queue_purge(&tp->out_of_order_queue); 1939 #ifdef CONFIG_NET_DMA 1940 __skb_queue_purge(&sk->sk_async_wait_queue); 1941 #endif 1942 1943 inet->dport = 0; 1944 1945 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1946 inet_reset_saddr(sk); 1947 1948 sk->sk_shutdown = 0; 1949 sock_reset_flag(sk, SOCK_DONE); 1950 tp->srtt = 0; 1951 if ((tp->write_seq += tp->max_window + 2) == 0) 1952 tp->write_seq = 1; 1953 icsk->icsk_backoff = 0; 1954 tp->snd_cwnd = 2; 1955 icsk->icsk_probes_out = 0; 1956 tp->packets_out = 0; 1957 tp->snd_ssthresh = 0x7fffffff; 1958 tp->snd_cwnd_cnt = 0; 1959 tp->bytes_acked = 0; 1960 tcp_set_ca_state(sk, TCP_CA_Open); 1961 tcp_clear_retrans(tp); 1962 inet_csk_delack_init(sk); 1963 tcp_init_send_head(sk); 1964 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 1965 __sk_dst_reset(sk); 1966 1967 BUG_TRAP(!inet->num || icsk->icsk_bind_hash); 1968 1969 sk->sk_error_report(sk); 1970 return err; 1971 } 1972 1973 /* 1974 * Socket option code for TCP. 1975 */ 1976 static int do_tcp_setsockopt(struct sock *sk, int level, 1977 int optname, char __user *optval, int optlen) 1978 { 1979 struct tcp_sock *tp = tcp_sk(sk); 1980 struct inet_connection_sock *icsk = inet_csk(sk); 1981 int val; 1982 int err = 0; 1983 1984 /* This is a string value all the others are int's */ 1985 if (optname == TCP_CONGESTION) { 1986 char name[TCP_CA_NAME_MAX]; 1987 1988 if (optlen < 1) 1989 return -EINVAL; 1990 1991 val = strncpy_from_user(name, optval, 1992 min(TCP_CA_NAME_MAX-1, optlen)); 1993 if (val < 0) 1994 return -EFAULT; 1995 name[val] = 0; 1996 1997 lock_sock(sk); 1998 err = tcp_set_congestion_control(sk, name); 1999 release_sock(sk); 2000 return err; 2001 } 2002 2003 if (optlen < sizeof(int)) 2004 return -EINVAL; 2005 2006 if (get_user(val, (int __user *)optval)) 2007 return -EFAULT; 2008 2009 lock_sock(sk); 2010 2011 switch (optname) { 2012 case TCP_MAXSEG: 2013 /* Values greater than interface MTU won't take effect. However 2014 * at the point when this call is done we typically don't yet 2015 * know which interface is going to be used */ 2016 if (val < 8 || val > MAX_TCP_WINDOW) { 2017 err = -EINVAL; 2018 break; 2019 } 2020 tp->rx_opt.user_mss = val; 2021 break; 2022 2023 case TCP_NODELAY: 2024 if (val) { 2025 /* TCP_NODELAY is weaker than TCP_CORK, so that 2026 * this option on corked socket is remembered, but 2027 * it is not activated until cork is cleared. 2028 * 2029 * However, when TCP_NODELAY is set we make 2030 * an explicit push, which overrides even TCP_CORK 2031 * for currently queued segments. 2032 */ 2033 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2034 tcp_push_pending_frames(sk); 2035 } else { 2036 tp->nonagle &= ~TCP_NAGLE_OFF; 2037 } 2038 break; 2039 2040 case TCP_CORK: 2041 /* When set indicates to always queue non-full frames. 2042 * Later the user clears this option and we transmit 2043 * any pending partial frames in the queue. This is 2044 * meant to be used alongside sendfile() to get properly 2045 * filled frames when the user (for example) must write 2046 * out headers with a write() call first and then use 2047 * sendfile to send out the data parts. 2048 * 2049 * TCP_CORK can be set together with TCP_NODELAY and it is 2050 * stronger than TCP_NODELAY. 2051 */ 2052 if (val) { 2053 tp->nonagle |= TCP_NAGLE_CORK; 2054 } else { 2055 tp->nonagle &= ~TCP_NAGLE_CORK; 2056 if (tp->nonagle&TCP_NAGLE_OFF) 2057 tp->nonagle |= TCP_NAGLE_PUSH; 2058 tcp_push_pending_frames(sk); 2059 } 2060 break; 2061 2062 case TCP_KEEPIDLE: 2063 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2064 err = -EINVAL; 2065 else { 2066 tp->keepalive_time = val * HZ; 2067 if (sock_flag(sk, SOCK_KEEPOPEN) && 2068 !((1 << sk->sk_state) & 2069 (TCPF_CLOSE | TCPF_LISTEN))) { 2070 __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp; 2071 if (tp->keepalive_time > elapsed) 2072 elapsed = tp->keepalive_time - elapsed; 2073 else 2074 elapsed = 0; 2075 inet_csk_reset_keepalive_timer(sk, elapsed); 2076 } 2077 } 2078 break; 2079 case TCP_KEEPINTVL: 2080 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2081 err = -EINVAL; 2082 else 2083 tp->keepalive_intvl = val * HZ; 2084 break; 2085 case TCP_KEEPCNT: 2086 if (val < 1 || val > MAX_TCP_KEEPCNT) 2087 err = -EINVAL; 2088 else 2089 tp->keepalive_probes = val; 2090 break; 2091 case TCP_SYNCNT: 2092 if (val < 1 || val > MAX_TCP_SYNCNT) 2093 err = -EINVAL; 2094 else 2095 icsk->icsk_syn_retries = val; 2096 break; 2097 2098 case TCP_LINGER2: 2099 if (val < 0) 2100 tp->linger2 = -1; 2101 else if (val > sysctl_tcp_fin_timeout / HZ) 2102 tp->linger2 = 0; 2103 else 2104 tp->linger2 = val * HZ; 2105 break; 2106 2107 case TCP_DEFER_ACCEPT: 2108 if (val < 0) { 2109 err = -EINVAL; 2110 } else { 2111 if (val > MAX_TCP_ACCEPT_DEFERRED) 2112 val = MAX_TCP_ACCEPT_DEFERRED; 2113 icsk->icsk_accept_queue.rskq_defer_accept = val; 2114 } 2115 break; 2116 2117 case TCP_WINDOW_CLAMP: 2118 if (!val) { 2119 if (sk->sk_state != TCP_CLOSE) { 2120 err = -EINVAL; 2121 break; 2122 } 2123 tp->window_clamp = 0; 2124 } else 2125 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2126 SOCK_MIN_RCVBUF / 2 : val; 2127 break; 2128 2129 case TCP_QUICKACK: 2130 if (!val) { 2131 icsk->icsk_ack.pingpong = 1; 2132 } else { 2133 icsk->icsk_ack.pingpong = 0; 2134 if ((1 << sk->sk_state) & 2135 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2136 inet_csk_ack_scheduled(sk)) { 2137 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2138 tcp_cleanup_rbuf(sk, 1); 2139 if (!(val & 1)) 2140 icsk->icsk_ack.pingpong = 1; 2141 } 2142 } 2143 break; 2144 2145 #ifdef CONFIG_TCP_MD5SIG 2146 case TCP_MD5SIG: 2147 /* Read the IP->Key mappings from userspace */ 2148 err = tp->af_specific->md5_parse(sk, optval, optlen); 2149 break; 2150 #endif 2151 2152 default: 2153 err = -ENOPROTOOPT; 2154 break; 2155 } 2156 2157 release_sock(sk); 2158 return err; 2159 } 2160 2161 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2162 int optlen) 2163 { 2164 struct inet_connection_sock *icsk = inet_csk(sk); 2165 2166 if (level != SOL_TCP) 2167 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2168 optval, optlen); 2169 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2170 } 2171 2172 #ifdef CONFIG_COMPAT 2173 int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2174 char __user *optval, int optlen) 2175 { 2176 if (level != SOL_TCP) 2177 return inet_csk_compat_setsockopt(sk, level, optname, 2178 optval, optlen); 2179 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2180 } 2181 2182 EXPORT_SYMBOL(compat_tcp_setsockopt); 2183 #endif 2184 2185 /* Return information about state of tcp endpoint in API format. */ 2186 void tcp_get_info(struct sock *sk, struct tcp_info *info) 2187 { 2188 struct tcp_sock *tp = tcp_sk(sk); 2189 const struct inet_connection_sock *icsk = inet_csk(sk); 2190 u32 now = tcp_time_stamp; 2191 2192 memset(info, 0, sizeof(*info)); 2193 2194 info->tcpi_state = sk->sk_state; 2195 info->tcpi_ca_state = icsk->icsk_ca_state; 2196 info->tcpi_retransmits = icsk->icsk_retransmits; 2197 info->tcpi_probes = icsk->icsk_probes_out; 2198 info->tcpi_backoff = icsk->icsk_backoff; 2199 2200 if (tp->rx_opt.tstamp_ok) 2201 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2202 if (tcp_is_sack(tp)) 2203 info->tcpi_options |= TCPI_OPT_SACK; 2204 if (tp->rx_opt.wscale_ok) { 2205 info->tcpi_options |= TCPI_OPT_WSCALE; 2206 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2207 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2208 } 2209 2210 if (tp->ecn_flags&TCP_ECN_OK) 2211 info->tcpi_options |= TCPI_OPT_ECN; 2212 2213 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2214 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2215 info->tcpi_snd_mss = tp->mss_cache; 2216 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2217 2218 if (sk->sk_state == TCP_LISTEN) { 2219 info->tcpi_unacked = sk->sk_ack_backlog; 2220 info->tcpi_sacked = sk->sk_max_ack_backlog; 2221 } else { 2222 info->tcpi_unacked = tp->packets_out; 2223 info->tcpi_sacked = tp->sacked_out; 2224 } 2225 info->tcpi_lost = tp->lost_out; 2226 info->tcpi_retrans = tp->retrans_out; 2227 info->tcpi_fackets = tp->fackets_out; 2228 2229 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2230 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2231 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2232 2233 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2234 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2235 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3; 2236 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2; 2237 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2238 info->tcpi_snd_cwnd = tp->snd_cwnd; 2239 info->tcpi_advmss = tp->advmss; 2240 info->tcpi_reordering = tp->reordering; 2241 2242 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; 2243 info->tcpi_rcv_space = tp->rcvq_space.space; 2244 2245 info->tcpi_total_retrans = tp->total_retrans; 2246 } 2247 2248 EXPORT_SYMBOL_GPL(tcp_get_info); 2249 2250 static int do_tcp_getsockopt(struct sock *sk, int level, 2251 int optname, char __user *optval, int __user *optlen) 2252 { 2253 struct inet_connection_sock *icsk = inet_csk(sk); 2254 struct tcp_sock *tp = tcp_sk(sk); 2255 int val, len; 2256 2257 if (get_user(len, optlen)) 2258 return -EFAULT; 2259 2260 len = min_t(unsigned int, len, sizeof(int)); 2261 2262 if (len < 0) 2263 return -EINVAL; 2264 2265 switch (optname) { 2266 case TCP_MAXSEG: 2267 val = tp->mss_cache; 2268 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2269 val = tp->rx_opt.user_mss; 2270 break; 2271 case TCP_NODELAY: 2272 val = !!(tp->nonagle&TCP_NAGLE_OFF); 2273 break; 2274 case TCP_CORK: 2275 val = !!(tp->nonagle&TCP_NAGLE_CORK); 2276 break; 2277 case TCP_KEEPIDLE: 2278 val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ; 2279 break; 2280 case TCP_KEEPINTVL: 2281 val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ; 2282 break; 2283 case TCP_KEEPCNT: 2284 val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; 2285 break; 2286 case TCP_SYNCNT: 2287 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 2288 break; 2289 case TCP_LINGER2: 2290 val = tp->linger2; 2291 if (val >= 0) 2292 val = (val ? : sysctl_tcp_fin_timeout) / HZ; 2293 break; 2294 case TCP_DEFER_ACCEPT: 2295 val = icsk->icsk_accept_queue.rskq_defer_accept; 2296 break; 2297 case TCP_WINDOW_CLAMP: 2298 val = tp->window_clamp; 2299 break; 2300 case TCP_INFO: { 2301 struct tcp_info info; 2302 2303 if (get_user(len, optlen)) 2304 return -EFAULT; 2305 2306 tcp_get_info(sk, &info); 2307 2308 len = min_t(unsigned int, len, sizeof(info)); 2309 if (put_user(len, optlen)) 2310 return -EFAULT; 2311 if (copy_to_user(optval, &info, len)) 2312 return -EFAULT; 2313 return 0; 2314 } 2315 case TCP_QUICKACK: 2316 val = !icsk->icsk_ack.pingpong; 2317 break; 2318 2319 case TCP_CONGESTION: 2320 if (get_user(len, optlen)) 2321 return -EFAULT; 2322 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 2323 if (put_user(len, optlen)) 2324 return -EFAULT; 2325 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 2326 return -EFAULT; 2327 return 0; 2328 default: 2329 return -ENOPROTOOPT; 2330 } 2331 2332 if (put_user(len, optlen)) 2333 return -EFAULT; 2334 if (copy_to_user(optval, &val, len)) 2335 return -EFAULT; 2336 return 0; 2337 } 2338 2339 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 2340 int __user *optlen) 2341 { 2342 struct inet_connection_sock *icsk = inet_csk(sk); 2343 2344 if (level != SOL_TCP) 2345 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 2346 optval, optlen); 2347 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2348 } 2349 2350 #ifdef CONFIG_COMPAT 2351 int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 2352 char __user *optval, int __user *optlen) 2353 { 2354 if (level != SOL_TCP) 2355 return inet_csk_compat_getsockopt(sk, level, optname, 2356 optval, optlen); 2357 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2358 } 2359 2360 EXPORT_SYMBOL(compat_tcp_getsockopt); 2361 #endif 2362 2363 struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features) 2364 { 2365 struct sk_buff *segs = ERR_PTR(-EINVAL); 2366 struct tcphdr *th; 2367 unsigned thlen; 2368 unsigned int seq; 2369 __be32 delta; 2370 unsigned int oldlen; 2371 unsigned int len; 2372 2373 if (!pskb_may_pull(skb, sizeof(*th))) 2374 goto out; 2375 2376 th = tcp_hdr(skb); 2377 thlen = th->doff * 4; 2378 if (thlen < sizeof(*th)) 2379 goto out; 2380 2381 if (!pskb_may_pull(skb, thlen)) 2382 goto out; 2383 2384 oldlen = (u16)~skb->len; 2385 __skb_pull(skb, thlen); 2386 2387 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2388 /* Packet is from an untrusted source, reset gso_segs. */ 2389 int type = skb_shinfo(skb)->gso_type; 2390 int mss; 2391 2392 if (unlikely(type & 2393 ~(SKB_GSO_TCPV4 | 2394 SKB_GSO_DODGY | 2395 SKB_GSO_TCP_ECN | 2396 SKB_GSO_TCPV6 | 2397 0) || 2398 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))) 2399 goto out; 2400 2401 mss = skb_shinfo(skb)->gso_size; 2402 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2403 2404 segs = NULL; 2405 goto out; 2406 } 2407 2408 segs = skb_segment(skb, features); 2409 if (IS_ERR(segs)) 2410 goto out; 2411 2412 len = skb_shinfo(skb)->gso_size; 2413 delta = htonl(oldlen + (thlen + len)); 2414 2415 skb = segs; 2416 th = tcp_hdr(skb); 2417 seq = ntohl(th->seq); 2418 2419 do { 2420 th->fin = th->psh = 0; 2421 2422 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2423 (__force u32)delta)); 2424 if (skb->ip_summed != CHECKSUM_PARTIAL) 2425 th->check = 2426 csum_fold(csum_partial(skb_transport_header(skb), 2427 thlen, skb->csum)); 2428 2429 seq += len; 2430 skb = skb->next; 2431 th = tcp_hdr(skb); 2432 2433 th->seq = htonl(seq); 2434 th->cwr = 0; 2435 } while (skb->next); 2436 2437 delta = htonl(oldlen + (skb->tail - skb->transport_header) + 2438 skb->data_len); 2439 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2440 (__force u32)delta)); 2441 if (skb->ip_summed != CHECKSUM_PARTIAL) 2442 th->check = csum_fold(csum_partial(skb_transport_header(skb), 2443 thlen, skb->csum)); 2444 2445 out: 2446 return segs; 2447 } 2448 EXPORT_SYMBOL(tcp_tso_segment); 2449 2450 #ifdef CONFIG_TCP_MD5SIG 2451 static unsigned long tcp_md5sig_users; 2452 static struct tcp_md5sig_pool **tcp_md5sig_pool; 2453 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock); 2454 2455 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool) 2456 { 2457 int cpu; 2458 for_each_possible_cpu(cpu) { 2459 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu); 2460 if (p) { 2461 if (p->md5_desc.tfm) 2462 crypto_free_hash(p->md5_desc.tfm); 2463 kfree(p); 2464 p = NULL; 2465 } 2466 } 2467 free_percpu(pool); 2468 } 2469 2470 void tcp_free_md5sig_pool(void) 2471 { 2472 struct tcp_md5sig_pool **pool = NULL; 2473 2474 spin_lock_bh(&tcp_md5sig_pool_lock); 2475 if (--tcp_md5sig_users == 0) { 2476 pool = tcp_md5sig_pool; 2477 tcp_md5sig_pool = NULL; 2478 } 2479 spin_unlock_bh(&tcp_md5sig_pool_lock); 2480 if (pool) 2481 __tcp_free_md5sig_pool(pool); 2482 } 2483 2484 EXPORT_SYMBOL(tcp_free_md5sig_pool); 2485 2486 static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void) 2487 { 2488 int cpu; 2489 struct tcp_md5sig_pool **pool; 2490 2491 pool = alloc_percpu(struct tcp_md5sig_pool *); 2492 if (!pool) 2493 return NULL; 2494 2495 for_each_possible_cpu(cpu) { 2496 struct tcp_md5sig_pool *p; 2497 struct crypto_hash *hash; 2498 2499 p = kzalloc(sizeof(*p), GFP_KERNEL); 2500 if (!p) 2501 goto out_free; 2502 *per_cpu_ptr(pool, cpu) = p; 2503 2504 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 2505 if (!hash || IS_ERR(hash)) 2506 goto out_free; 2507 2508 p->md5_desc.tfm = hash; 2509 } 2510 return pool; 2511 out_free: 2512 __tcp_free_md5sig_pool(pool); 2513 return NULL; 2514 } 2515 2516 struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void) 2517 { 2518 struct tcp_md5sig_pool **pool; 2519 int alloc = 0; 2520 2521 retry: 2522 spin_lock_bh(&tcp_md5sig_pool_lock); 2523 pool = tcp_md5sig_pool; 2524 if (tcp_md5sig_users++ == 0) { 2525 alloc = 1; 2526 spin_unlock_bh(&tcp_md5sig_pool_lock); 2527 } else if (!pool) { 2528 tcp_md5sig_users--; 2529 spin_unlock_bh(&tcp_md5sig_pool_lock); 2530 cpu_relax(); 2531 goto retry; 2532 } else 2533 spin_unlock_bh(&tcp_md5sig_pool_lock); 2534 2535 if (alloc) { 2536 /* we cannot hold spinlock here because this may sleep. */ 2537 struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool(); 2538 spin_lock_bh(&tcp_md5sig_pool_lock); 2539 if (!p) { 2540 tcp_md5sig_users--; 2541 spin_unlock_bh(&tcp_md5sig_pool_lock); 2542 return NULL; 2543 } 2544 pool = tcp_md5sig_pool; 2545 if (pool) { 2546 /* oops, it has already been assigned. */ 2547 spin_unlock_bh(&tcp_md5sig_pool_lock); 2548 __tcp_free_md5sig_pool(p); 2549 } else { 2550 tcp_md5sig_pool = pool = p; 2551 spin_unlock_bh(&tcp_md5sig_pool_lock); 2552 } 2553 } 2554 return pool; 2555 } 2556 2557 EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 2558 2559 struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu) 2560 { 2561 struct tcp_md5sig_pool **p; 2562 spin_lock_bh(&tcp_md5sig_pool_lock); 2563 p = tcp_md5sig_pool; 2564 if (p) 2565 tcp_md5sig_users++; 2566 spin_unlock_bh(&tcp_md5sig_pool_lock); 2567 return (p ? *per_cpu_ptr(p, cpu) : NULL); 2568 } 2569 2570 EXPORT_SYMBOL(__tcp_get_md5sig_pool); 2571 2572 void __tcp_put_md5sig_pool(void) 2573 { 2574 tcp_free_md5sig_pool(); 2575 } 2576 2577 EXPORT_SYMBOL(__tcp_put_md5sig_pool); 2578 #endif 2579 2580 void tcp_done(struct sock *sk) 2581 { 2582 if(sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 2583 TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS); 2584 2585 tcp_set_state(sk, TCP_CLOSE); 2586 tcp_clear_xmit_timers(sk); 2587 2588 sk->sk_shutdown = SHUTDOWN_MASK; 2589 2590 if (!sock_flag(sk, SOCK_DEAD)) 2591 sk->sk_state_change(sk); 2592 else 2593 inet_csk_destroy_sock(sk); 2594 } 2595 EXPORT_SYMBOL_GPL(tcp_done); 2596 2597 extern struct tcp_congestion_ops tcp_reno; 2598 2599 static __initdata unsigned long thash_entries; 2600 static int __init set_thash_entries(char *str) 2601 { 2602 if (!str) 2603 return 0; 2604 thash_entries = simple_strtoul(str, &str, 0); 2605 return 1; 2606 } 2607 __setup("thash_entries=", set_thash_entries); 2608 2609 void __init tcp_init(void) 2610 { 2611 struct sk_buff *skb = NULL; 2612 unsigned long limit; 2613 int order, i, max_share; 2614 2615 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); 2616 2617 tcp_hashinfo.bind_bucket_cachep = 2618 kmem_cache_create("tcp_bind_bucket", 2619 sizeof(struct inet_bind_bucket), 0, 2620 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2621 2622 /* Size and allocate the main established and bind bucket 2623 * hash tables. 2624 * 2625 * The methodology is similar to that of the buffer cache. 2626 */ 2627 tcp_hashinfo.ehash = 2628 alloc_large_system_hash("TCP established", 2629 sizeof(struct inet_ehash_bucket), 2630 thash_entries, 2631 (num_physpages >= 128 * 1024) ? 2632 13 : 15, 2633 0, 2634 &tcp_hashinfo.ehash_size, 2635 NULL, 2636 thash_entries ? 0 : 512 * 1024); 2637 tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size; 2638 for (i = 0; i < tcp_hashinfo.ehash_size; i++) { 2639 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].chain); 2640 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].twchain); 2641 } 2642 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 2643 panic("TCP: failed to alloc ehash_locks"); 2644 tcp_hashinfo.bhash = 2645 alloc_large_system_hash("TCP bind", 2646 sizeof(struct inet_bind_hashbucket), 2647 tcp_hashinfo.ehash_size, 2648 (num_physpages >= 128 * 1024) ? 2649 13 : 15, 2650 0, 2651 &tcp_hashinfo.bhash_size, 2652 NULL, 2653 64 * 1024); 2654 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size; 2655 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 2656 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 2657 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 2658 } 2659 2660 /* Try to be a bit smarter and adjust defaults depending 2661 * on available memory. 2662 */ 2663 for (order = 0; ((1 << order) << PAGE_SHIFT) < 2664 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket)); 2665 order++) 2666 ; 2667 if (order >= 4) { 2668 tcp_death_row.sysctl_max_tw_buckets = 180000; 2669 sysctl_tcp_max_orphans = 4096 << (order - 4); 2670 sysctl_max_syn_backlog = 1024; 2671 } else if (order < 3) { 2672 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order); 2673 sysctl_tcp_max_orphans >>= (3 - order); 2674 sysctl_max_syn_backlog = 128; 2675 } 2676 2677 /* Set the pressure threshold to be a fraction of global memory that 2678 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of 2679 * memory, with a floor of 128 pages. 2680 */ 2681 limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); 2682 limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); 2683 limit = max(limit, 128UL); 2684 sysctl_tcp_mem[0] = limit / 4 * 3; 2685 sysctl_tcp_mem[1] = limit; 2686 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; 2687 2688 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 2689 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7); 2690 max_share = min(4UL*1024*1024, limit); 2691 2692 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 2693 sysctl_tcp_wmem[1] = 16*1024; 2694 sysctl_tcp_wmem[2] = max(64*1024, max_share); 2695 2696 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 2697 sysctl_tcp_rmem[1] = 87380; 2698 sysctl_tcp_rmem[2] = max(87380, max_share); 2699 2700 printk(KERN_INFO "TCP: Hash tables configured " 2701 "(established %d bind %d)\n", 2702 tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size); 2703 2704 tcp_register_congestion_control(&tcp_reno); 2705 } 2706 2707 EXPORT_SYMBOL(tcp_close); 2708 EXPORT_SYMBOL(tcp_disconnect); 2709 EXPORT_SYMBOL(tcp_getsockopt); 2710 EXPORT_SYMBOL(tcp_ioctl); 2711 EXPORT_SYMBOL(tcp_poll); 2712 EXPORT_SYMBOL(tcp_read_sock); 2713 EXPORT_SYMBOL(tcp_recvmsg); 2714 EXPORT_SYMBOL(tcp_sendmsg); 2715 EXPORT_SYMBOL(tcp_splice_read); 2716 EXPORT_SYMBOL(tcp_sendpage); 2717 EXPORT_SYMBOL(tcp_setsockopt); 2718 EXPORT_SYMBOL(tcp_shutdown); 2719 EXPORT_SYMBOL(tcp_statistics); 2720