tcp.c revision f67b45999205164958de4ec0658d51fa4bee066d
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> 267 268#include <net/icmp.h> 269#include <net/tcp.h> 270#include <net/xfrm.h> 271#include <net/ip.h> 272#include <net/netdma.h> 273#include <net/sock.h> 274 275#include <asm/uaccess.h> 276#include <asm/ioctls.h> 277 278int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; 279 280struct percpu_counter tcp_orphan_count; 281EXPORT_SYMBOL_GPL(tcp_orphan_count); 282 283int sysctl_tcp_mem[3] __read_mostly; 284int sysctl_tcp_wmem[3] __read_mostly; 285int sysctl_tcp_rmem[3] __read_mostly; 286 287EXPORT_SYMBOL(sysctl_tcp_mem); 288EXPORT_SYMBOL(sysctl_tcp_rmem); 289EXPORT_SYMBOL(sysctl_tcp_wmem); 290 291atomic_t tcp_memory_allocated; /* Current allocated memory. */ 292EXPORT_SYMBOL(tcp_memory_allocated); 293 294/* 295 * Current number of TCP sockets. 296 */ 297struct percpu_counter tcp_sockets_allocated; 298EXPORT_SYMBOL(tcp_sockets_allocated); 299 300/* 301 * TCP splice context 302 */ 303struct tcp_splice_state { 304 struct pipe_inode_info *pipe; 305 size_t len; 306 unsigned int flags; 307}; 308 309/* 310 * Pressure flag: try to collapse. 311 * Technical note: it is used by multiple contexts non atomically. 312 * All the __sk_mem_schedule() is of this nature: accounting 313 * is strict, actions are advisory and have some latency. 314 */ 315int tcp_memory_pressure __read_mostly; 316 317EXPORT_SYMBOL(tcp_memory_pressure); 318 319void tcp_enter_memory_pressure(struct sock *sk) 320{ 321 if (!tcp_memory_pressure) { 322 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); 323 tcp_memory_pressure = 1; 324 } 325} 326 327EXPORT_SYMBOL(tcp_enter_memory_pressure); 328 329/* 330 * Wait for a TCP event. 331 * 332 * Note that we don't need to lock the socket, as the upper poll layers 333 * take care of normal races (between the test and the event) and we don't 334 * go look at any of the socket buffers directly. 335 */ 336unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 337{ 338 unsigned int mask; 339 struct sock *sk = sock->sk; 340 struct tcp_sock *tp = tcp_sk(sk); 341 342 poll_wait(file, sk->sk_sleep, wait); 343 if (sk->sk_state == TCP_LISTEN) 344 return inet_csk_listen_poll(sk); 345 346 /* Socket is not locked. We are protected from async events 347 * by poll logic and correct handling of state changes 348 * made by other threads is impossible in any case. 349 */ 350 351 mask = 0; 352 if (sk->sk_err) 353 mask = POLLERR; 354 355 /* 356 * POLLHUP is certainly not done right. But poll() doesn't 357 * have a notion of HUP in just one direction, and for a 358 * socket the read side is more interesting. 359 * 360 * Some poll() documentation says that POLLHUP is incompatible 361 * with the POLLOUT/POLLWR flags, so somebody should check this 362 * all. But careful, it tends to be safer to return too many 363 * bits than too few, and you can easily break real applications 364 * if you don't tell them that something has hung up! 365 * 366 * Check-me. 367 * 368 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and 369 * our fs/select.c). It means that after we received EOF, 370 * poll always returns immediately, making impossible poll() on write() 371 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP 372 * if and only if shutdown has been made in both directions. 373 * Actually, it is interesting to look how Solaris and DUX 374 * solve this dilemma. I would prefer, if POLLHUP were maskable, 375 * then we could set it on SND_SHUTDOWN. BTW examples given 376 * in Stevens' books assume exactly this behaviour, it explains 377 * why POLLHUP is incompatible with POLLOUT. --ANK 378 * 379 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 380 * blocking on fresh not-connected or disconnected socket. --ANK 381 */ 382 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) 383 mask |= POLLHUP; 384 if (sk->sk_shutdown & RCV_SHUTDOWN) 385 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 386 387 /* Connected? */ 388 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { 389 int target = sock_rcvlowat(sk, 0, INT_MAX); 390 391 if (tp->urg_seq == tp->copied_seq && 392 !sock_flag(sk, SOCK_URGINLINE) && 393 tp->urg_data) 394 target--; 395 396 /* Potential race condition. If read of tp below will 397 * escape above sk->sk_state, we can be illegally awaken 398 * in SYN_* states. */ 399 if (tp->rcv_nxt - tp->copied_seq >= target) 400 mask |= POLLIN | POLLRDNORM; 401 402 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 403 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 404 mask |= POLLOUT | POLLWRNORM; 405 } else { /* send SIGIO later */ 406 set_bit(SOCK_ASYNC_NOSPACE, 407 &sk->sk_socket->flags); 408 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 409 410 /* Race breaker. If space is freed after 411 * wspace test but before the flags are set, 412 * IO signal will be lost. 413 */ 414 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) 415 mask |= POLLOUT | POLLWRNORM; 416 } 417 } 418 419 if (tp->urg_data & TCP_URG_VALID) 420 mask |= POLLPRI; 421 } 422 return mask; 423} 424 425int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 426{ 427 struct tcp_sock *tp = tcp_sk(sk); 428 int answ; 429 430 switch (cmd) { 431 case SIOCINQ: 432 if (sk->sk_state == TCP_LISTEN) 433 return -EINVAL; 434 435 lock_sock(sk); 436 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 437 answ = 0; 438 else if (sock_flag(sk, SOCK_URGINLINE) || 439 !tp->urg_data || 440 before(tp->urg_seq, tp->copied_seq) || 441 !before(tp->urg_seq, tp->rcv_nxt)) { 442 answ = tp->rcv_nxt - tp->copied_seq; 443 444 /* Subtract 1, if FIN is in queue. */ 445 if (answ && !skb_queue_empty(&sk->sk_receive_queue)) 446 answ -= 447 tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin; 448 } else 449 answ = tp->urg_seq - tp->copied_seq; 450 release_sock(sk); 451 break; 452 case SIOCATMARK: 453 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 454 break; 455 case SIOCOUTQ: 456 if (sk->sk_state == TCP_LISTEN) 457 return -EINVAL; 458 459 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 460 answ = 0; 461 else 462 answ = tp->write_seq - tp->snd_una; 463 break; 464 default: 465 return -ENOIOCTLCMD; 466 } 467 468 return put_user(answ, (int __user *)arg); 469} 470 471static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 472{ 473 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH; 474 tp->pushed_seq = tp->write_seq; 475} 476 477static inline int forced_push(struct tcp_sock *tp) 478{ 479 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 480} 481 482static inline void skb_entail(struct sock *sk, struct sk_buff *skb) 483{ 484 struct tcp_sock *tp = tcp_sk(sk); 485 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 486 487 skb->csum = 0; 488 tcb->seq = tcb->end_seq = tp->write_seq; 489 tcb->flags = TCPCB_FLAG_ACK; 490 tcb->sacked = 0; 491 skb_header_release(skb); 492 tcp_add_write_queue_tail(sk, skb); 493 sk->sk_wmem_queued += skb->truesize; 494 sk_mem_charge(sk, skb->truesize); 495 if (tp->nonagle & TCP_NAGLE_PUSH) 496 tp->nonagle &= ~TCP_NAGLE_PUSH; 497} 498 499static inline void tcp_mark_urg(struct tcp_sock *tp, int flags, 500 struct sk_buff *skb) 501{ 502 if (flags & MSG_OOB) 503 tp->snd_up = tp->write_seq; 504} 505 506static inline void tcp_push(struct sock *sk, int flags, int mss_now, 507 int nonagle) 508{ 509 struct tcp_sock *tp = tcp_sk(sk); 510 511 if (tcp_send_head(sk)) { 512 struct sk_buff *skb = tcp_write_queue_tail(sk); 513 if (!(flags & MSG_MORE) || forced_push(tp)) 514 tcp_mark_push(tp, skb); 515 tcp_mark_urg(tp, flags, skb); 516 __tcp_push_pending_frames(sk, mss_now, 517 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); 518 } 519} 520 521static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 522 unsigned int offset, size_t len) 523{ 524 struct tcp_splice_state *tss = rd_desc->arg.data; 525 526 return skb_splice_bits(skb, offset, tss->pipe, tss->len, tss->flags); 527} 528 529static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 530{ 531 /* Store TCP splice context information in read_descriptor_t. */ 532 read_descriptor_t rd_desc = { 533 .arg.data = tss, 534 }; 535 536 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 537} 538 539/** 540 * tcp_splice_read - splice data from TCP socket to a pipe 541 * @sock: socket to splice from 542 * @ppos: position (not valid) 543 * @pipe: pipe to splice to 544 * @len: number of bytes to splice 545 * @flags: splice modifier flags 546 * 547 * Description: 548 * Will read pages from given socket and fill them into a pipe. 549 * 550 **/ 551ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 552 struct pipe_inode_info *pipe, size_t len, 553 unsigned int flags) 554{ 555 struct sock *sk = sock->sk; 556 struct tcp_splice_state tss = { 557 .pipe = pipe, 558 .len = len, 559 .flags = flags, 560 }; 561 long timeo; 562 ssize_t spliced; 563 int ret; 564 565 /* 566 * We can't seek on a socket input 567 */ 568 if (unlikely(*ppos)) 569 return -ESPIPE; 570 571 ret = spliced = 0; 572 573 lock_sock(sk); 574 575 timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK); 576 while (tss.len) { 577 ret = __tcp_splice_read(sk, &tss); 578 if (ret < 0) 579 break; 580 else if (!ret) { 581 if (spliced) 582 break; 583 if (flags & SPLICE_F_NONBLOCK) { 584 ret = -EAGAIN; 585 break; 586 } 587 if (sock_flag(sk, SOCK_DONE)) 588 break; 589 if (sk->sk_err) { 590 ret = sock_error(sk); 591 break; 592 } 593 if (sk->sk_shutdown & RCV_SHUTDOWN) 594 break; 595 if (sk->sk_state == TCP_CLOSE) { 596 /* 597 * This occurs when user tries to read 598 * from never connected socket. 599 */ 600 if (!sock_flag(sk, SOCK_DONE)) 601 ret = -ENOTCONN; 602 break; 603 } 604 if (!timeo) { 605 ret = -EAGAIN; 606 break; 607 } 608 sk_wait_data(sk, &timeo); 609 if (signal_pending(current)) { 610 ret = sock_intr_errno(timeo); 611 break; 612 } 613 continue; 614 } 615 tss.len -= ret; 616 spliced += ret; 617 618 release_sock(sk); 619 lock_sock(sk); 620 621 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 622 (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo || 623 signal_pending(current)) 624 break; 625 } 626 627 release_sock(sk); 628 629 if (spliced) 630 return spliced; 631 632 return ret; 633} 634 635struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) 636{ 637 struct sk_buff *skb; 638 639 /* The TCP header must be at least 32-bit aligned. */ 640 size = ALIGN(size, 4); 641 642 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 643 if (skb) { 644 if (sk_wmem_schedule(sk, skb->truesize)) { 645 /* 646 * Make sure that we have exactly size bytes 647 * available to the caller, no more, no less. 648 */ 649 skb_reserve(skb, skb_tailroom(skb) - size); 650 return skb; 651 } 652 __kfree_skb(skb); 653 } else { 654 sk->sk_prot->enter_memory_pressure(sk); 655 sk_stream_moderate_sndbuf(sk); 656 } 657 return NULL; 658} 659 660static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, 661 size_t psize, int flags) 662{ 663 struct tcp_sock *tp = tcp_sk(sk); 664 int mss_now, size_goal; 665 int err; 666 ssize_t copied; 667 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 668 669 /* Wait for a connection to finish. */ 670 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 671 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 672 goto out_err; 673 674 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 675 676 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); 677 size_goal = tp->xmit_size_goal; 678 copied = 0; 679 680 err = -EPIPE; 681 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 682 goto do_error; 683 684 while (psize > 0) { 685 struct sk_buff *skb = tcp_write_queue_tail(sk); 686 struct page *page = pages[poffset / PAGE_SIZE]; 687 int copy, i, can_coalesce; 688 int offset = poffset % PAGE_SIZE; 689 int size = min_t(size_t, psize, PAGE_SIZE - offset); 690 691 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { 692new_segment: 693 if (!sk_stream_memory_free(sk)) 694 goto wait_for_sndbuf; 695 696 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); 697 if (!skb) 698 goto wait_for_memory; 699 700 skb_entail(sk, skb); 701 copy = size_goal; 702 } 703 704 if (copy > size) 705 copy = size; 706 707 i = skb_shinfo(skb)->nr_frags; 708 can_coalesce = skb_can_coalesce(skb, i, page, offset); 709 if (!can_coalesce && i >= MAX_SKB_FRAGS) { 710 tcp_mark_push(tp, skb); 711 goto new_segment; 712 } 713 if (!sk_wmem_schedule(sk, copy)) 714 goto wait_for_memory; 715 716 if (can_coalesce) { 717 skb_shinfo(skb)->frags[i - 1].size += copy; 718 } else { 719 get_page(page); 720 skb_fill_page_desc(skb, i, page, offset, copy); 721 } 722 723 skb->len += copy; 724 skb->data_len += copy; 725 skb->truesize += copy; 726 sk->sk_wmem_queued += copy; 727 sk_mem_charge(sk, copy); 728 skb->ip_summed = CHECKSUM_PARTIAL; 729 tp->write_seq += copy; 730 TCP_SKB_CB(skb)->end_seq += copy; 731 skb_shinfo(skb)->gso_segs = 0; 732 733 if (!copied) 734 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 735 736 copied += copy; 737 poffset += copy; 738 if (!(psize -= copy)) 739 goto out; 740 741 if (skb->len < size_goal || (flags & MSG_OOB)) 742 continue; 743 744 if (forced_push(tp)) { 745 tcp_mark_push(tp, skb); 746 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 747 } else if (skb == tcp_send_head(sk)) 748 tcp_push_one(sk, mss_now); 749 continue; 750 751wait_for_sndbuf: 752 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 753wait_for_memory: 754 if (copied) 755 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 756 757 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 758 goto do_error; 759 760 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); 761 size_goal = tp->xmit_size_goal; 762 } 763 764out: 765 if (copied) 766 tcp_push(sk, flags, mss_now, tp->nonagle); 767 return copied; 768 769do_error: 770 if (copied) 771 goto out; 772out_err: 773 return sk_stream_error(sk, flags, err); 774} 775 776ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, 777 size_t size, int flags) 778{ 779 ssize_t res; 780 struct sock *sk = sock->sk; 781 782 if (!(sk->sk_route_caps & NETIF_F_SG) || 783 !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) 784 return sock_no_sendpage(sock, page, offset, size, flags); 785 786 lock_sock(sk); 787 TCP_CHECK_TIMER(sk); 788 res = do_tcp_sendpages(sk, &page, offset, size, flags); 789 TCP_CHECK_TIMER(sk); 790 release_sock(sk); 791 return res; 792} 793 794#define TCP_PAGE(sk) (sk->sk_sndmsg_page) 795#define TCP_OFF(sk) (sk->sk_sndmsg_off) 796 797static inline int select_size(struct sock *sk) 798{ 799 struct tcp_sock *tp = tcp_sk(sk); 800 int tmp = tp->mss_cache; 801 802 if (sk->sk_route_caps & NETIF_F_SG) { 803 if (sk_can_gso(sk)) 804 tmp = 0; 805 else { 806 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); 807 808 if (tmp >= pgbreak && 809 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) 810 tmp = pgbreak; 811 } 812 } 813 814 return tmp; 815} 816 817int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, 818 size_t size) 819{ 820 struct sock *sk = sock->sk; 821 struct iovec *iov; 822 struct tcp_sock *tp = tcp_sk(sk); 823 struct sk_buff *skb; 824 int iovlen, flags; 825 int mss_now, size_goal; 826 int err, copied; 827 long timeo; 828 829 lock_sock(sk); 830 TCP_CHECK_TIMER(sk); 831 832 flags = msg->msg_flags; 833 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 834 835 /* Wait for a connection to finish. */ 836 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 837 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 838 goto out_err; 839 840 /* This should be in poll */ 841 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 842 843 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); 844 size_goal = tp->xmit_size_goal; 845 846 /* Ok commence sending. */ 847 iovlen = msg->msg_iovlen; 848 iov = msg->msg_iov; 849 copied = 0; 850 851 err = -EPIPE; 852 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 853 goto do_error; 854 855 while (--iovlen >= 0) { 856 int seglen = iov->iov_len; 857 unsigned char __user *from = iov->iov_base; 858 859 iov++; 860 861 while (seglen > 0) { 862 int copy; 863 864 skb = tcp_write_queue_tail(sk); 865 866 if (!tcp_send_head(sk) || 867 (copy = size_goal - skb->len) <= 0) { 868 869new_segment: 870 /* Allocate new segment. If the interface is SG, 871 * allocate skb fitting to single page. 872 */ 873 if (!sk_stream_memory_free(sk)) 874 goto wait_for_sndbuf; 875 876 skb = sk_stream_alloc_skb(sk, select_size(sk), 877 sk->sk_allocation); 878 if (!skb) 879 goto wait_for_memory; 880 881 /* 882 * Check whether we can use HW checksum. 883 */ 884 if (sk->sk_route_caps & NETIF_F_ALL_CSUM) 885 skb->ip_summed = CHECKSUM_PARTIAL; 886 887 skb_entail(sk, skb); 888 copy = size_goal; 889 } 890 891 /* Try to append data to the end of skb. */ 892 if (copy > seglen) 893 copy = seglen; 894 895 /* Where to copy to? */ 896 if (skb_tailroom(skb) > 0) { 897 /* We have some space in skb head. Superb! */ 898 if (copy > skb_tailroom(skb)) 899 copy = skb_tailroom(skb); 900 if ((err = skb_add_data(skb, from, copy)) != 0) 901 goto do_fault; 902 } else { 903 int merge = 0; 904 int i = skb_shinfo(skb)->nr_frags; 905 struct page *page = TCP_PAGE(sk); 906 int off = TCP_OFF(sk); 907 908 if (skb_can_coalesce(skb, i, page, off) && 909 off != PAGE_SIZE) { 910 /* We can extend the last page 911 * fragment. */ 912 merge = 1; 913 } else if (i == MAX_SKB_FRAGS || 914 (!i && 915 !(sk->sk_route_caps & NETIF_F_SG))) { 916 /* Need to add new fragment and cannot 917 * do this because interface is non-SG, 918 * or because all the page slots are 919 * busy. */ 920 tcp_mark_push(tp, skb); 921 goto new_segment; 922 } else if (page) { 923 if (off == PAGE_SIZE) { 924 put_page(page); 925 TCP_PAGE(sk) = page = NULL; 926 off = 0; 927 } 928 } else 929 off = 0; 930 931 if (copy > PAGE_SIZE - off) 932 copy = PAGE_SIZE - off; 933 934 if (!sk_wmem_schedule(sk, copy)) 935 goto wait_for_memory; 936 937 if (!page) { 938 /* Allocate new cache page. */ 939 if (!(page = sk_stream_alloc_page(sk))) 940 goto wait_for_memory; 941 } 942 943 /* Time to copy data. We are close to 944 * the end! */ 945 err = skb_copy_to_page(sk, from, skb, page, 946 off, copy); 947 if (err) { 948 /* If this page was new, give it to the 949 * socket so it does not get leaked. 950 */ 951 if (!TCP_PAGE(sk)) { 952 TCP_PAGE(sk) = page; 953 TCP_OFF(sk) = 0; 954 } 955 goto do_error; 956 } 957 958 /* Update the skb. */ 959 if (merge) { 960 skb_shinfo(skb)->frags[i - 1].size += 961 copy; 962 } else { 963 skb_fill_page_desc(skb, i, page, off, copy); 964 if (TCP_PAGE(sk)) { 965 get_page(page); 966 } else if (off + copy < PAGE_SIZE) { 967 get_page(page); 968 TCP_PAGE(sk) = page; 969 } 970 } 971 972 TCP_OFF(sk) = off + copy; 973 } 974 975 if (!copied) 976 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 977 978 tp->write_seq += copy; 979 TCP_SKB_CB(skb)->end_seq += copy; 980 skb_shinfo(skb)->gso_segs = 0; 981 982 from += copy; 983 copied += copy; 984 if ((seglen -= copy) == 0 && iovlen == 0) 985 goto out; 986 987 if (skb->len < size_goal || (flags & MSG_OOB)) 988 continue; 989 990 if (forced_push(tp)) { 991 tcp_mark_push(tp, skb); 992 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 993 } else if (skb == tcp_send_head(sk)) 994 tcp_push_one(sk, mss_now); 995 continue; 996 997wait_for_sndbuf: 998 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 999wait_for_memory: 1000 if (copied) 1001 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 1002 1003 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 1004 goto do_error; 1005 1006 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); 1007 size_goal = tp->xmit_size_goal; 1008 } 1009 } 1010 1011out: 1012 if (copied) 1013 tcp_push(sk, flags, mss_now, tp->nonagle); 1014 TCP_CHECK_TIMER(sk); 1015 release_sock(sk); 1016 return copied; 1017 1018do_fault: 1019 if (!skb->len) { 1020 tcp_unlink_write_queue(skb, sk); 1021 /* It is the one place in all of TCP, except connection 1022 * reset, where we can be unlinking the send_head. 1023 */ 1024 tcp_check_send_head(sk, skb); 1025 sk_wmem_free_skb(sk, skb); 1026 } 1027 1028do_error: 1029 if (copied) 1030 goto out; 1031out_err: 1032 err = sk_stream_error(sk, flags, err); 1033 TCP_CHECK_TIMER(sk); 1034 release_sock(sk); 1035 return err; 1036} 1037 1038/* 1039 * Handle reading urgent data. BSD has very simple semantics for 1040 * this, no blocking and very strange errors 8) 1041 */ 1042 1043static int tcp_recv_urg(struct sock *sk, long timeo, 1044 struct msghdr *msg, int len, int flags, 1045 int *addr_len) 1046{ 1047 struct tcp_sock *tp = tcp_sk(sk); 1048 1049 /* No URG data to read. */ 1050 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1051 tp->urg_data == TCP_URG_READ) 1052 return -EINVAL; /* Yes this is right ! */ 1053 1054 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1055 return -ENOTCONN; 1056 1057 if (tp->urg_data & TCP_URG_VALID) { 1058 int err = 0; 1059 char c = tp->urg_data; 1060 1061 if (!(flags & MSG_PEEK)) 1062 tp->urg_data = TCP_URG_READ; 1063 1064 /* Read urgent data. */ 1065 msg->msg_flags |= MSG_OOB; 1066 1067 if (len > 0) { 1068 if (!(flags & MSG_TRUNC)) 1069 err = memcpy_toiovec(msg->msg_iov, &c, 1); 1070 len = 1; 1071 } else 1072 msg->msg_flags |= MSG_TRUNC; 1073 1074 return err ? -EFAULT : len; 1075 } 1076 1077 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1078 return 0; 1079 1080 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1081 * the available implementations agree in this case: 1082 * this call should never block, independent of the 1083 * blocking state of the socket. 1084 * Mike <pall@rz.uni-karlsruhe.de> 1085 */ 1086 return -EAGAIN; 1087} 1088 1089/* Clean up the receive buffer for full frames taken by the user, 1090 * then send an ACK if necessary. COPIED is the number of bytes 1091 * tcp_recvmsg has given to the user so far, it speeds up the 1092 * calculation of whether or not we must ACK for the sake of 1093 * a window update. 1094 */ 1095void tcp_cleanup_rbuf(struct sock *sk, int copied) 1096{ 1097 struct tcp_sock *tp = tcp_sk(sk); 1098 int time_to_ack = 0; 1099 1100#if TCP_DEBUG 1101 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1102 1103 WARN_ON(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq)); 1104#endif 1105 1106 if (inet_csk_ack_scheduled(sk)) { 1107 const struct inet_connection_sock *icsk = inet_csk(sk); 1108 /* Delayed ACKs frequently hit locked sockets during bulk 1109 * receive. */ 1110 if (icsk->icsk_ack.blocked || 1111 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1112 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1113 /* 1114 * If this read emptied read buffer, we send ACK, if 1115 * connection is not bidirectional, user drained 1116 * receive buffer and there was a small segment 1117 * in queue. 1118 */ 1119 (copied > 0 && 1120 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1121 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1122 !icsk->icsk_ack.pingpong)) && 1123 !atomic_read(&sk->sk_rmem_alloc))) 1124 time_to_ack = 1; 1125 } 1126 1127 /* We send an ACK if we can now advertise a non-zero window 1128 * which has been raised "significantly". 1129 * 1130 * Even if window raised up to infinity, do not send window open ACK 1131 * in states, where we will not receive more. It is useless. 1132 */ 1133 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1134 __u32 rcv_window_now = tcp_receive_window(tp); 1135 1136 /* Optimize, __tcp_select_window() is not cheap. */ 1137 if (2*rcv_window_now <= tp->window_clamp) { 1138 __u32 new_window = __tcp_select_window(sk); 1139 1140 /* Send ACK now, if this read freed lots of space 1141 * in our buffer. Certainly, new_window is new window. 1142 * We can advertise it now, if it is not less than current one. 1143 * "Lots" means "at least twice" here. 1144 */ 1145 if (new_window && new_window >= 2 * rcv_window_now) 1146 time_to_ack = 1; 1147 } 1148 } 1149 if (time_to_ack) 1150 tcp_send_ack(sk); 1151} 1152 1153static void tcp_prequeue_process(struct sock *sk) 1154{ 1155 struct sk_buff *skb; 1156 struct tcp_sock *tp = tcp_sk(sk); 1157 1158 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); 1159 1160 /* RX process wants to run with disabled BHs, though it is not 1161 * necessary */ 1162 local_bh_disable(); 1163 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) 1164 sk_backlog_rcv(sk, skb); 1165 local_bh_enable(); 1166 1167 /* Clear memory counter. */ 1168 tp->ucopy.memory = 0; 1169} 1170 1171static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1172{ 1173 struct sk_buff *skb; 1174 u32 offset; 1175 1176 skb_queue_walk(&sk->sk_receive_queue, skb) { 1177 offset = seq - TCP_SKB_CB(skb)->seq; 1178 if (tcp_hdr(skb)->syn) 1179 offset--; 1180 if (offset < skb->len || tcp_hdr(skb)->fin) { 1181 *off = offset; 1182 return skb; 1183 } 1184 } 1185 return NULL; 1186} 1187 1188/* 1189 * This routine provides an alternative to tcp_recvmsg() for routines 1190 * that would like to handle copying from skbuffs directly in 'sendfile' 1191 * fashion. 1192 * Note: 1193 * - It is assumed that the socket was locked by the caller. 1194 * - The routine does not block. 1195 * - At present, there is no support for reading OOB data 1196 * or for 'peeking' the socket using this routine 1197 * (although both would be easy to implement). 1198 */ 1199int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1200 sk_read_actor_t recv_actor) 1201{ 1202 struct sk_buff *skb; 1203 struct tcp_sock *tp = tcp_sk(sk); 1204 u32 seq = tp->copied_seq; 1205 u32 offset; 1206 int copied = 0; 1207 1208 if (sk->sk_state == TCP_LISTEN) 1209 return -ENOTCONN; 1210 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1211 if (offset < skb->len) { 1212 int used; 1213 size_t len; 1214 1215 len = skb->len - offset; 1216 /* Stop reading if we hit a patch of urgent data */ 1217 if (tp->urg_data) { 1218 u32 urg_offset = tp->urg_seq - seq; 1219 if (urg_offset < len) 1220 len = urg_offset; 1221 if (!len) 1222 break; 1223 } 1224 used = recv_actor(desc, skb, offset, len); 1225 if (used < 0) { 1226 if (!copied) 1227 copied = used; 1228 break; 1229 } else if (used <= len) { 1230 seq += used; 1231 copied += used; 1232 offset += used; 1233 } 1234 /* 1235 * If recv_actor drops the lock (e.g. TCP splice 1236 * receive) the skb pointer might be invalid when 1237 * getting here: tcp_collapse might have deleted it 1238 * while aggregating skbs from the socket queue. 1239 */ 1240 skb = tcp_recv_skb(sk, seq-1, &offset); 1241 if (!skb || (offset+1 != skb->len)) 1242 break; 1243 } 1244 if (tcp_hdr(skb)->fin) { 1245 sk_eat_skb(sk, skb, 0); 1246 ++seq; 1247 break; 1248 } 1249 sk_eat_skb(sk, skb, 0); 1250 if (!desc->count) 1251 break; 1252 } 1253 tp->copied_seq = seq; 1254 1255 tcp_rcv_space_adjust(sk); 1256 1257 /* Clean up data we have read: This will do ACK frames. */ 1258 if (copied > 0) 1259 tcp_cleanup_rbuf(sk, copied); 1260 return copied; 1261} 1262 1263/* 1264 * This routine copies from a sock struct into the user buffer. 1265 * 1266 * Technical note: in 2.3 we work on _locked_ socket, so that 1267 * tricks with *seq access order and skb->users are not required. 1268 * Probably, code can be easily improved even more. 1269 */ 1270 1271int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1272 size_t len, int nonblock, int flags, int *addr_len) 1273{ 1274 struct tcp_sock *tp = tcp_sk(sk); 1275 int copied = 0; 1276 u32 peek_seq; 1277 u32 *seq; 1278 unsigned long used; 1279 int err; 1280 int target; /* Read at least this many bytes */ 1281 long timeo; 1282 struct task_struct *user_recv = NULL; 1283 int copied_early = 0; 1284 struct sk_buff *skb; 1285 1286 lock_sock(sk); 1287 1288 TCP_CHECK_TIMER(sk); 1289 1290 err = -ENOTCONN; 1291 if (sk->sk_state == TCP_LISTEN) 1292 goto out; 1293 1294 timeo = sock_rcvtimeo(sk, nonblock); 1295 1296 /* Urgent data needs to be handled specially. */ 1297 if (flags & MSG_OOB) 1298 goto recv_urg; 1299 1300 seq = &tp->copied_seq; 1301 if (flags & MSG_PEEK) { 1302 peek_seq = tp->copied_seq; 1303 seq = &peek_seq; 1304 } 1305 1306 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1307 1308#ifdef CONFIG_NET_DMA 1309 tp->ucopy.dma_chan = NULL; 1310 preempt_disable(); 1311 skb = skb_peek_tail(&sk->sk_receive_queue); 1312 { 1313 int available = 0; 1314 1315 if (skb) 1316 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); 1317 if ((available < target) && 1318 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && 1319 !sysctl_tcp_low_latency && 1320 dma_find_channel(DMA_MEMCPY)) { 1321 preempt_enable_no_resched(); 1322 tp->ucopy.pinned_list = 1323 dma_pin_iovec_pages(msg->msg_iov, len); 1324 } else { 1325 preempt_enable_no_resched(); 1326 } 1327 } 1328#endif 1329 1330 do { 1331 u32 offset; 1332 1333 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1334 if (tp->urg_data && tp->urg_seq == *seq) { 1335 if (copied) 1336 break; 1337 if (signal_pending(current)) { 1338 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1339 break; 1340 } 1341 } 1342 1343 /* Next get a buffer. */ 1344 1345 skb = skb_peek(&sk->sk_receive_queue); 1346 do { 1347 if (!skb) 1348 break; 1349 1350 /* Now that we have two receive queues this 1351 * shouldn't happen. 1352 */ 1353 if (before(*seq, TCP_SKB_CB(skb)->seq)) { 1354 printk(KERN_INFO "recvmsg bug: copied %X " 1355 "seq %X\n", *seq, TCP_SKB_CB(skb)->seq); 1356 break; 1357 } 1358 offset = *seq - TCP_SKB_CB(skb)->seq; 1359 if (tcp_hdr(skb)->syn) 1360 offset--; 1361 if (offset < skb->len) 1362 goto found_ok_skb; 1363 if (tcp_hdr(skb)->fin) 1364 goto found_fin_ok; 1365 WARN_ON(!(flags & MSG_PEEK)); 1366 skb = skb->next; 1367 } while (skb != (struct sk_buff *)&sk->sk_receive_queue); 1368 1369 /* Well, if we have backlog, try to process it now yet. */ 1370 1371 if (copied >= target && !sk->sk_backlog.tail) 1372 break; 1373 1374 if (copied) { 1375 if (sk->sk_err || 1376 sk->sk_state == TCP_CLOSE || 1377 (sk->sk_shutdown & RCV_SHUTDOWN) || 1378 !timeo || 1379 signal_pending(current)) 1380 break; 1381 } else { 1382 if (sock_flag(sk, SOCK_DONE)) 1383 break; 1384 1385 if (sk->sk_err) { 1386 copied = sock_error(sk); 1387 break; 1388 } 1389 1390 if (sk->sk_shutdown & RCV_SHUTDOWN) 1391 break; 1392 1393 if (sk->sk_state == TCP_CLOSE) { 1394 if (!sock_flag(sk, SOCK_DONE)) { 1395 /* This occurs when user tries to read 1396 * from never connected socket. 1397 */ 1398 copied = -ENOTCONN; 1399 break; 1400 } 1401 break; 1402 } 1403 1404 if (!timeo) { 1405 copied = -EAGAIN; 1406 break; 1407 } 1408 1409 if (signal_pending(current)) { 1410 copied = sock_intr_errno(timeo); 1411 break; 1412 } 1413 } 1414 1415 tcp_cleanup_rbuf(sk, copied); 1416 1417 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { 1418 /* Install new reader */ 1419 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { 1420 user_recv = current; 1421 tp->ucopy.task = user_recv; 1422 tp->ucopy.iov = msg->msg_iov; 1423 } 1424 1425 tp->ucopy.len = len; 1426 1427 WARN_ON(tp->copied_seq != tp->rcv_nxt && 1428 !(flags & (MSG_PEEK | MSG_TRUNC))); 1429 1430 /* Ugly... If prequeue is not empty, we have to 1431 * process it before releasing socket, otherwise 1432 * order will be broken at second iteration. 1433 * More elegant solution is required!!! 1434 * 1435 * Look: we have the following (pseudo)queues: 1436 * 1437 * 1. packets in flight 1438 * 2. backlog 1439 * 3. prequeue 1440 * 4. receive_queue 1441 * 1442 * Each queue can be processed only if the next ones 1443 * are empty. At this point we have empty receive_queue. 1444 * But prequeue _can_ be not empty after 2nd iteration, 1445 * when we jumped to start of loop because backlog 1446 * processing added something to receive_queue. 1447 * We cannot release_sock(), because backlog contains 1448 * packets arrived _after_ prequeued ones. 1449 * 1450 * Shortly, algorithm is clear --- to process all 1451 * the queues in order. We could make it more directly, 1452 * requeueing packets from backlog to prequeue, if 1453 * is not empty. It is more elegant, but eats cycles, 1454 * unfortunately. 1455 */ 1456 if (!skb_queue_empty(&tp->ucopy.prequeue)) 1457 goto do_prequeue; 1458 1459 /* __ Set realtime policy in scheduler __ */ 1460 } 1461 1462 if (copied >= target) { 1463 /* Do not sleep, just process backlog. */ 1464 release_sock(sk); 1465 lock_sock(sk); 1466 } else 1467 sk_wait_data(sk, &timeo); 1468 1469#ifdef CONFIG_NET_DMA 1470 tp->ucopy.wakeup = 0; 1471#endif 1472 1473 if (user_recv) { 1474 int chunk; 1475 1476 /* __ Restore normal policy in scheduler __ */ 1477 1478 if ((chunk = len - tp->ucopy.len) != 0) { 1479 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); 1480 len -= chunk; 1481 copied += chunk; 1482 } 1483 1484 if (tp->rcv_nxt == tp->copied_seq && 1485 !skb_queue_empty(&tp->ucopy.prequeue)) { 1486do_prequeue: 1487 tcp_prequeue_process(sk); 1488 1489 if ((chunk = len - tp->ucopy.len) != 0) { 1490 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1491 len -= chunk; 1492 copied += chunk; 1493 } 1494 } 1495 } 1496 if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) { 1497 if (net_ratelimit()) 1498 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n", 1499 current->comm, task_pid_nr(current)); 1500 peek_seq = tp->copied_seq; 1501 } 1502 continue; 1503 1504 found_ok_skb: 1505 /* Ok so how much can we use? */ 1506 used = skb->len - offset; 1507 if (len < used) 1508 used = len; 1509 1510 /* Do we have urgent data here? */ 1511 if (tp->urg_data) { 1512 u32 urg_offset = tp->urg_seq - *seq; 1513 if (urg_offset < used) { 1514 if (!urg_offset) { 1515 if (!sock_flag(sk, SOCK_URGINLINE)) { 1516 ++*seq; 1517 offset++; 1518 used--; 1519 if (!used) 1520 goto skip_copy; 1521 } 1522 } else 1523 used = urg_offset; 1524 } 1525 } 1526 1527 if (!(flags & MSG_TRUNC)) { 1528#ifdef CONFIG_NET_DMA 1529 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1530 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); 1531 1532 if (tp->ucopy.dma_chan) { 1533 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( 1534 tp->ucopy.dma_chan, skb, offset, 1535 msg->msg_iov, used, 1536 tp->ucopy.pinned_list); 1537 1538 if (tp->ucopy.dma_cookie < 0) { 1539 1540 printk(KERN_ALERT "dma_cookie < 0\n"); 1541 1542 /* Exception. Bailout! */ 1543 if (!copied) 1544 copied = -EFAULT; 1545 break; 1546 } 1547 if ((offset + used) == skb->len) 1548 copied_early = 1; 1549 1550 } else 1551#endif 1552 { 1553 err = skb_copy_datagram_iovec(skb, offset, 1554 msg->msg_iov, used); 1555 if (err) { 1556 /* Exception. Bailout! */ 1557 if (!copied) 1558 copied = -EFAULT; 1559 break; 1560 } 1561 } 1562 } 1563 1564 *seq += used; 1565 copied += used; 1566 len -= used; 1567 1568 tcp_rcv_space_adjust(sk); 1569 1570skip_copy: 1571 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1572 tp->urg_data = 0; 1573 tcp_fast_path_check(sk); 1574 } 1575 if (used + offset < skb->len) 1576 continue; 1577 1578 if (tcp_hdr(skb)->fin) 1579 goto found_fin_ok; 1580 if (!(flags & MSG_PEEK)) { 1581 sk_eat_skb(sk, skb, copied_early); 1582 copied_early = 0; 1583 } 1584 continue; 1585 1586 found_fin_ok: 1587 /* Process the FIN. */ 1588 ++*seq; 1589 if (!(flags & MSG_PEEK)) { 1590 sk_eat_skb(sk, skb, copied_early); 1591 copied_early = 0; 1592 } 1593 break; 1594 } while (len > 0); 1595 1596 if (user_recv) { 1597 if (!skb_queue_empty(&tp->ucopy.prequeue)) { 1598 int chunk; 1599 1600 tp->ucopy.len = copied > 0 ? len : 0; 1601 1602 tcp_prequeue_process(sk); 1603 1604 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { 1605 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1606 len -= chunk; 1607 copied += chunk; 1608 } 1609 } 1610 1611 tp->ucopy.task = NULL; 1612 tp->ucopy.len = 0; 1613 } 1614 1615#ifdef CONFIG_NET_DMA 1616 if (tp->ucopy.dma_chan) { 1617 dma_cookie_t done, used; 1618 1619 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1620 1621 while (dma_async_memcpy_complete(tp->ucopy.dma_chan, 1622 tp->ucopy.dma_cookie, &done, 1623 &used) == DMA_IN_PROGRESS) { 1624 /* do partial cleanup of sk_async_wait_queue */ 1625 while ((skb = skb_peek(&sk->sk_async_wait_queue)) && 1626 (dma_async_is_complete(skb->dma_cookie, done, 1627 used) == DMA_SUCCESS)) { 1628 __skb_dequeue(&sk->sk_async_wait_queue); 1629 kfree_skb(skb); 1630 } 1631 } 1632 1633 /* Safe to free early-copied skbs now */ 1634 __skb_queue_purge(&sk->sk_async_wait_queue); 1635 tp->ucopy.dma_chan = NULL; 1636 } 1637 if (tp->ucopy.pinned_list) { 1638 dma_unpin_iovec_pages(tp->ucopy.pinned_list); 1639 tp->ucopy.pinned_list = NULL; 1640 } 1641#endif 1642 1643 /* According to UNIX98, msg_name/msg_namelen are ignored 1644 * on connected socket. I was just happy when found this 8) --ANK 1645 */ 1646 1647 /* Clean up data we have read: This will do ACK frames. */ 1648 tcp_cleanup_rbuf(sk, copied); 1649 1650 TCP_CHECK_TIMER(sk); 1651 release_sock(sk); 1652 return copied; 1653 1654out: 1655 TCP_CHECK_TIMER(sk); 1656 release_sock(sk); 1657 return err; 1658 1659recv_urg: 1660 err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len); 1661 goto out; 1662} 1663 1664void tcp_set_state(struct sock *sk, int state) 1665{ 1666 int oldstate = sk->sk_state; 1667 1668 switch (state) { 1669 case TCP_ESTABLISHED: 1670 if (oldstate != TCP_ESTABLISHED) 1671 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1672 break; 1673 1674 case TCP_CLOSE: 1675 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 1676 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 1677 1678 sk->sk_prot->unhash(sk); 1679 if (inet_csk(sk)->icsk_bind_hash && 1680 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1681 inet_put_port(sk); 1682 /* fall through */ 1683 default: 1684 if (oldstate == TCP_ESTABLISHED) 1685 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1686 } 1687 1688 /* Change state AFTER socket is unhashed to avoid closed 1689 * socket sitting in hash tables. 1690 */ 1691 sk->sk_state = state; 1692 1693#ifdef STATE_TRACE 1694 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); 1695#endif 1696} 1697EXPORT_SYMBOL_GPL(tcp_set_state); 1698 1699/* 1700 * State processing on a close. This implements the state shift for 1701 * sending our FIN frame. Note that we only send a FIN for some 1702 * states. A shutdown() may have already sent the FIN, or we may be 1703 * closed. 1704 */ 1705 1706static const unsigned char new_state[16] = { 1707 /* current state: new state: action: */ 1708 /* (Invalid) */ TCP_CLOSE, 1709 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1710 /* TCP_SYN_SENT */ TCP_CLOSE, 1711 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1712 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, 1713 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, 1714 /* TCP_TIME_WAIT */ TCP_CLOSE, 1715 /* TCP_CLOSE */ TCP_CLOSE, 1716 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, 1717 /* TCP_LAST_ACK */ TCP_LAST_ACK, 1718 /* TCP_LISTEN */ TCP_CLOSE, 1719 /* TCP_CLOSING */ TCP_CLOSING, 1720}; 1721 1722static int tcp_close_state(struct sock *sk) 1723{ 1724 int next = (int)new_state[sk->sk_state]; 1725 int ns = next & TCP_STATE_MASK; 1726 1727 tcp_set_state(sk, ns); 1728 1729 return next & TCP_ACTION_FIN; 1730} 1731 1732/* 1733 * Shutdown the sending side of a connection. Much like close except 1734 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 1735 */ 1736 1737void tcp_shutdown(struct sock *sk, int how) 1738{ 1739 /* We need to grab some memory, and put together a FIN, 1740 * and then put it into the queue to be sent. 1741 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 1742 */ 1743 if (!(how & SEND_SHUTDOWN)) 1744 return; 1745 1746 /* If we've already sent a FIN, or it's a closed state, skip this. */ 1747 if ((1 << sk->sk_state) & 1748 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 1749 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 1750 /* Clear out any half completed packets. FIN if needed. */ 1751 if (tcp_close_state(sk)) 1752 tcp_send_fin(sk); 1753 } 1754} 1755 1756void tcp_close(struct sock *sk, long timeout) 1757{ 1758 struct sk_buff *skb; 1759 int data_was_unread = 0; 1760 int state; 1761 1762 lock_sock(sk); 1763 sk->sk_shutdown = SHUTDOWN_MASK; 1764 1765 if (sk->sk_state == TCP_LISTEN) { 1766 tcp_set_state(sk, TCP_CLOSE); 1767 1768 /* Special case. */ 1769 inet_csk_listen_stop(sk); 1770 1771 goto adjudge_to_death; 1772 } 1773 1774 /* We need to flush the recv. buffs. We do this only on the 1775 * descriptor close, not protocol-sourced closes, because the 1776 * reader process may not have drained the data yet! 1777 */ 1778 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1779 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - 1780 tcp_hdr(skb)->fin; 1781 data_was_unread += len; 1782 __kfree_skb(skb); 1783 } 1784 1785 sk_mem_reclaim(sk); 1786 1787 /* As outlined in RFC 2525, section 2.17, we send a RST here because 1788 * data was lost. To witness the awful effects of the old behavior of 1789 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 1790 * GET in an FTP client, suspend the process, wait for the client to 1791 * advertise a zero window, then kill -9 the FTP client, wheee... 1792 * Note: timeout is always zero in such a case. 1793 */ 1794 if (data_was_unread) { 1795 /* Unread data was tossed, zap the connection. */ 1796 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 1797 tcp_set_state(sk, TCP_CLOSE); 1798 tcp_send_active_reset(sk, GFP_KERNEL); 1799 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1800 /* Check zero linger _after_ checking for unread data. */ 1801 sk->sk_prot->disconnect(sk, 0); 1802 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 1803 } else if (tcp_close_state(sk)) { 1804 /* We FIN if the application ate all the data before 1805 * zapping the connection. 1806 */ 1807 1808 /* RED-PEN. Formally speaking, we have broken TCP state 1809 * machine. State transitions: 1810 * 1811 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 1812 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 1813 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 1814 * 1815 * are legal only when FIN has been sent (i.e. in window), 1816 * rather than queued out of window. Purists blame. 1817 * 1818 * F.e. "RFC state" is ESTABLISHED, 1819 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 1820 * 1821 * The visible declinations are that sometimes 1822 * we enter time-wait state, when it is not required really 1823 * (harmless), do not send active resets, when they are 1824 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 1825 * they look as CLOSING or LAST_ACK for Linux) 1826 * Probably, I missed some more holelets. 1827 * --ANK 1828 */ 1829 tcp_send_fin(sk); 1830 } 1831 1832 sk_stream_wait_close(sk, timeout); 1833 1834adjudge_to_death: 1835 state = sk->sk_state; 1836 sock_hold(sk); 1837 sock_orphan(sk); 1838 1839 /* It is the last release_sock in its life. It will remove backlog. */ 1840 release_sock(sk); 1841 1842 1843 /* Now socket is owned by kernel and we acquire BH lock 1844 to finish close. No need to check for user refs. 1845 */ 1846 local_bh_disable(); 1847 bh_lock_sock(sk); 1848 WARN_ON(sock_owned_by_user(sk)); 1849 1850 percpu_counter_inc(sk->sk_prot->orphan_count); 1851 1852 /* Have we already been destroyed by a softirq or backlog? */ 1853 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 1854 goto out; 1855 1856 /* This is a (useful) BSD violating of the RFC. There is a 1857 * problem with TCP as specified in that the other end could 1858 * keep a socket open forever with no application left this end. 1859 * We use a 3 minute timeout (about the same as BSD) then kill 1860 * our end. If they send after that then tough - BUT: long enough 1861 * that we won't make the old 4*rto = almost no time - whoops 1862 * reset mistake. 1863 * 1864 * Nope, it was not mistake. It is really desired behaviour 1865 * f.e. on http servers, when such sockets are useless, but 1866 * consume significant resources. Let's do it with special 1867 * linger2 option. --ANK 1868 */ 1869 1870 if (sk->sk_state == TCP_FIN_WAIT2) { 1871 struct tcp_sock *tp = tcp_sk(sk); 1872 if (tp->linger2 < 0) { 1873 tcp_set_state(sk, TCP_CLOSE); 1874 tcp_send_active_reset(sk, GFP_ATOMIC); 1875 NET_INC_STATS_BH(sock_net(sk), 1876 LINUX_MIB_TCPABORTONLINGER); 1877 } else { 1878 const int tmo = tcp_fin_time(sk); 1879 1880 if (tmo > TCP_TIMEWAIT_LEN) { 1881 inet_csk_reset_keepalive_timer(sk, 1882 tmo - TCP_TIMEWAIT_LEN); 1883 } else { 1884 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 1885 goto out; 1886 } 1887 } 1888 } 1889 if (sk->sk_state != TCP_CLOSE) { 1890 int orphan_count = percpu_counter_read_positive( 1891 sk->sk_prot->orphan_count); 1892 1893 sk_mem_reclaim(sk); 1894 if (tcp_too_many_orphans(sk, orphan_count)) { 1895 if (net_ratelimit()) 1896 printk(KERN_INFO "TCP: too many of orphaned " 1897 "sockets\n"); 1898 tcp_set_state(sk, TCP_CLOSE); 1899 tcp_send_active_reset(sk, GFP_ATOMIC); 1900 NET_INC_STATS_BH(sock_net(sk), 1901 LINUX_MIB_TCPABORTONMEMORY); 1902 } 1903 } 1904 1905 if (sk->sk_state == TCP_CLOSE) 1906 inet_csk_destroy_sock(sk); 1907 /* Otherwise, socket is reprieved until protocol close. */ 1908 1909out: 1910 bh_unlock_sock(sk); 1911 local_bh_enable(); 1912 sock_put(sk); 1913} 1914 1915/* These states need RST on ABORT according to RFC793 */ 1916 1917static inline int tcp_need_reset(int state) 1918{ 1919 return (1 << state) & 1920 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 1921 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 1922} 1923 1924int tcp_disconnect(struct sock *sk, int flags) 1925{ 1926 struct inet_sock *inet = inet_sk(sk); 1927 struct inet_connection_sock *icsk = inet_csk(sk); 1928 struct tcp_sock *tp = tcp_sk(sk); 1929 int err = 0; 1930 int old_state = sk->sk_state; 1931 1932 if (old_state != TCP_CLOSE) 1933 tcp_set_state(sk, TCP_CLOSE); 1934 1935 /* ABORT function of RFC793 */ 1936 if (old_state == TCP_LISTEN) { 1937 inet_csk_listen_stop(sk); 1938 } else if (tcp_need_reset(old_state) || 1939 (tp->snd_nxt != tp->write_seq && 1940 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 1941 /* The last check adjusts for discrepancy of Linux wrt. RFC 1942 * states 1943 */ 1944 tcp_send_active_reset(sk, gfp_any()); 1945 sk->sk_err = ECONNRESET; 1946 } else if (old_state == TCP_SYN_SENT) 1947 sk->sk_err = ECONNRESET; 1948 1949 tcp_clear_xmit_timers(sk); 1950 __skb_queue_purge(&sk->sk_receive_queue); 1951 tcp_write_queue_purge(sk); 1952 __skb_queue_purge(&tp->out_of_order_queue); 1953#ifdef CONFIG_NET_DMA 1954 __skb_queue_purge(&sk->sk_async_wait_queue); 1955#endif 1956 1957 inet->dport = 0; 1958 1959 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1960 inet_reset_saddr(sk); 1961 1962 sk->sk_shutdown = 0; 1963 sock_reset_flag(sk, SOCK_DONE); 1964 tp->srtt = 0; 1965 if ((tp->write_seq += tp->max_window + 2) == 0) 1966 tp->write_seq = 1; 1967 icsk->icsk_backoff = 0; 1968 tp->snd_cwnd = 2; 1969 icsk->icsk_probes_out = 0; 1970 tp->packets_out = 0; 1971 tp->snd_ssthresh = 0x7fffffff; 1972 tp->snd_cwnd_cnt = 0; 1973 tp->bytes_acked = 0; 1974 tcp_set_ca_state(sk, TCP_CA_Open); 1975 tcp_clear_retrans(tp); 1976 inet_csk_delack_init(sk); 1977 tcp_init_send_head(sk); 1978 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 1979 __sk_dst_reset(sk); 1980 1981 WARN_ON(inet->num && !icsk->icsk_bind_hash); 1982 1983 sk->sk_error_report(sk); 1984 return err; 1985} 1986 1987/* 1988 * Socket option code for TCP. 1989 */ 1990static int do_tcp_setsockopt(struct sock *sk, int level, 1991 int optname, char __user *optval, int optlen) 1992{ 1993 struct tcp_sock *tp = tcp_sk(sk); 1994 struct inet_connection_sock *icsk = inet_csk(sk); 1995 int val; 1996 int err = 0; 1997 1998 /* This is a string value all the others are int's */ 1999 if (optname == TCP_CONGESTION) { 2000 char name[TCP_CA_NAME_MAX]; 2001 2002 if (optlen < 1) 2003 return -EINVAL; 2004 2005 val = strncpy_from_user(name, optval, 2006 min(TCP_CA_NAME_MAX-1, optlen)); 2007 if (val < 0) 2008 return -EFAULT; 2009 name[val] = 0; 2010 2011 lock_sock(sk); 2012 err = tcp_set_congestion_control(sk, name); 2013 release_sock(sk); 2014 return err; 2015 } 2016 2017 if (optlen < sizeof(int)) 2018 return -EINVAL; 2019 2020 if (get_user(val, (int __user *)optval)) 2021 return -EFAULT; 2022 2023 lock_sock(sk); 2024 2025 switch (optname) { 2026 case TCP_MAXSEG: 2027 /* Values greater than interface MTU won't take effect. However 2028 * at the point when this call is done we typically don't yet 2029 * know which interface is going to be used */ 2030 if (val < 8 || val > MAX_TCP_WINDOW) { 2031 err = -EINVAL; 2032 break; 2033 } 2034 tp->rx_opt.user_mss = val; 2035 break; 2036 2037 case TCP_NODELAY: 2038 if (val) { 2039 /* TCP_NODELAY is weaker than TCP_CORK, so that 2040 * this option on corked socket is remembered, but 2041 * it is not activated until cork is cleared. 2042 * 2043 * However, when TCP_NODELAY is set we make 2044 * an explicit push, which overrides even TCP_CORK 2045 * for currently queued segments. 2046 */ 2047 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2048 tcp_push_pending_frames(sk); 2049 } else { 2050 tp->nonagle &= ~TCP_NAGLE_OFF; 2051 } 2052 break; 2053 2054 case TCP_CORK: 2055 /* When set indicates to always queue non-full frames. 2056 * Later the user clears this option and we transmit 2057 * any pending partial frames in the queue. This is 2058 * meant to be used alongside sendfile() to get properly 2059 * filled frames when the user (for example) must write 2060 * out headers with a write() call first and then use 2061 * sendfile to send out the data parts. 2062 * 2063 * TCP_CORK can be set together with TCP_NODELAY and it is 2064 * stronger than TCP_NODELAY. 2065 */ 2066 if (val) { 2067 tp->nonagle |= TCP_NAGLE_CORK; 2068 } else { 2069 tp->nonagle &= ~TCP_NAGLE_CORK; 2070 if (tp->nonagle&TCP_NAGLE_OFF) 2071 tp->nonagle |= TCP_NAGLE_PUSH; 2072 tcp_push_pending_frames(sk); 2073 } 2074 break; 2075 2076 case TCP_KEEPIDLE: 2077 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2078 err = -EINVAL; 2079 else { 2080 tp->keepalive_time = val * HZ; 2081 if (sock_flag(sk, SOCK_KEEPOPEN) && 2082 !((1 << sk->sk_state) & 2083 (TCPF_CLOSE | TCPF_LISTEN))) { 2084 __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp; 2085 if (tp->keepalive_time > elapsed) 2086 elapsed = tp->keepalive_time - elapsed; 2087 else 2088 elapsed = 0; 2089 inet_csk_reset_keepalive_timer(sk, elapsed); 2090 } 2091 } 2092 break; 2093 case TCP_KEEPINTVL: 2094 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2095 err = -EINVAL; 2096 else 2097 tp->keepalive_intvl = val * HZ; 2098 break; 2099 case TCP_KEEPCNT: 2100 if (val < 1 || val > MAX_TCP_KEEPCNT) 2101 err = -EINVAL; 2102 else 2103 tp->keepalive_probes = val; 2104 break; 2105 case TCP_SYNCNT: 2106 if (val < 1 || val > MAX_TCP_SYNCNT) 2107 err = -EINVAL; 2108 else 2109 icsk->icsk_syn_retries = val; 2110 break; 2111 2112 case TCP_LINGER2: 2113 if (val < 0) 2114 tp->linger2 = -1; 2115 else if (val > sysctl_tcp_fin_timeout / HZ) 2116 tp->linger2 = 0; 2117 else 2118 tp->linger2 = val * HZ; 2119 break; 2120 2121 case TCP_DEFER_ACCEPT: 2122 icsk->icsk_accept_queue.rskq_defer_accept = 0; 2123 if (val > 0) { 2124 /* Translate value in seconds to number of 2125 * retransmits */ 2126 while (icsk->icsk_accept_queue.rskq_defer_accept < 32 && 2127 val > ((TCP_TIMEOUT_INIT / HZ) << 2128 icsk->icsk_accept_queue.rskq_defer_accept)) 2129 icsk->icsk_accept_queue.rskq_defer_accept++; 2130 icsk->icsk_accept_queue.rskq_defer_accept++; 2131 } 2132 break; 2133 2134 case TCP_WINDOW_CLAMP: 2135 if (!val) { 2136 if (sk->sk_state != TCP_CLOSE) { 2137 err = -EINVAL; 2138 break; 2139 } 2140 tp->window_clamp = 0; 2141 } else 2142 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2143 SOCK_MIN_RCVBUF / 2 : val; 2144 break; 2145 2146 case TCP_QUICKACK: 2147 if (!val) { 2148 icsk->icsk_ack.pingpong = 1; 2149 } else { 2150 icsk->icsk_ack.pingpong = 0; 2151 if ((1 << sk->sk_state) & 2152 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2153 inet_csk_ack_scheduled(sk)) { 2154 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2155 tcp_cleanup_rbuf(sk, 1); 2156 if (!(val & 1)) 2157 icsk->icsk_ack.pingpong = 1; 2158 } 2159 } 2160 break; 2161 2162#ifdef CONFIG_TCP_MD5SIG 2163 case TCP_MD5SIG: 2164 /* Read the IP->Key mappings from userspace */ 2165 err = tp->af_specific->md5_parse(sk, optval, optlen); 2166 break; 2167#endif 2168 2169 default: 2170 err = -ENOPROTOOPT; 2171 break; 2172 } 2173 2174 release_sock(sk); 2175 return err; 2176} 2177 2178int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2179 int optlen) 2180{ 2181 struct inet_connection_sock *icsk = inet_csk(sk); 2182 2183 if (level != SOL_TCP) 2184 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2185 optval, optlen); 2186 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2187} 2188 2189#ifdef CONFIG_COMPAT 2190int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2191 char __user *optval, int optlen) 2192{ 2193 if (level != SOL_TCP) 2194 return inet_csk_compat_setsockopt(sk, level, optname, 2195 optval, optlen); 2196 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2197} 2198 2199EXPORT_SYMBOL(compat_tcp_setsockopt); 2200#endif 2201 2202/* Return information about state of tcp endpoint in API format. */ 2203void tcp_get_info(struct sock *sk, struct tcp_info *info) 2204{ 2205 struct tcp_sock *tp = tcp_sk(sk); 2206 const struct inet_connection_sock *icsk = inet_csk(sk); 2207 u32 now = tcp_time_stamp; 2208 2209 memset(info, 0, sizeof(*info)); 2210 2211 info->tcpi_state = sk->sk_state; 2212 info->tcpi_ca_state = icsk->icsk_ca_state; 2213 info->tcpi_retransmits = icsk->icsk_retransmits; 2214 info->tcpi_probes = icsk->icsk_probes_out; 2215 info->tcpi_backoff = icsk->icsk_backoff; 2216 2217 if (tp->rx_opt.tstamp_ok) 2218 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2219 if (tcp_is_sack(tp)) 2220 info->tcpi_options |= TCPI_OPT_SACK; 2221 if (tp->rx_opt.wscale_ok) { 2222 info->tcpi_options |= TCPI_OPT_WSCALE; 2223 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2224 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2225 } 2226 2227 if (tp->ecn_flags&TCP_ECN_OK) 2228 info->tcpi_options |= TCPI_OPT_ECN; 2229 2230 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2231 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2232 info->tcpi_snd_mss = tp->mss_cache; 2233 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2234 2235 if (sk->sk_state == TCP_LISTEN) { 2236 info->tcpi_unacked = sk->sk_ack_backlog; 2237 info->tcpi_sacked = sk->sk_max_ack_backlog; 2238 } else { 2239 info->tcpi_unacked = tp->packets_out; 2240 info->tcpi_sacked = tp->sacked_out; 2241 } 2242 info->tcpi_lost = tp->lost_out; 2243 info->tcpi_retrans = tp->retrans_out; 2244 info->tcpi_fackets = tp->fackets_out; 2245 2246 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2247 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2248 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2249 2250 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2251 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2252 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3; 2253 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2; 2254 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2255 info->tcpi_snd_cwnd = tp->snd_cwnd; 2256 info->tcpi_advmss = tp->advmss; 2257 info->tcpi_reordering = tp->reordering; 2258 2259 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; 2260 info->tcpi_rcv_space = tp->rcvq_space.space; 2261 2262 info->tcpi_total_retrans = tp->total_retrans; 2263} 2264 2265EXPORT_SYMBOL_GPL(tcp_get_info); 2266 2267static int do_tcp_getsockopt(struct sock *sk, int level, 2268 int optname, char __user *optval, int __user *optlen) 2269{ 2270 struct inet_connection_sock *icsk = inet_csk(sk); 2271 struct tcp_sock *tp = tcp_sk(sk); 2272 int val, len; 2273 2274 if (get_user(len, optlen)) 2275 return -EFAULT; 2276 2277 len = min_t(unsigned int, len, sizeof(int)); 2278 2279 if (len < 0) 2280 return -EINVAL; 2281 2282 switch (optname) { 2283 case TCP_MAXSEG: 2284 val = tp->mss_cache; 2285 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2286 val = tp->rx_opt.user_mss; 2287 break; 2288 case TCP_NODELAY: 2289 val = !!(tp->nonagle&TCP_NAGLE_OFF); 2290 break; 2291 case TCP_CORK: 2292 val = !!(tp->nonagle&TCP_NAGLE_CORK); 2293 break; 2294 case TCP_KEEPIDLE: 2295 val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ; 2296 break; 2297 case TCP_KEEPINTVL: 2298 val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ; 2299 break; 2300 case TCP_KEEPCNT: 2301 val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; 2302 break; 2303 case TCP_SYNCNT: 2304 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 2305 break; 2306 case TCP_LINGER2: 2307 val = tp->linger2; 2308 if (val >= 0) 2309 val = (val ? : sysctl_tcp_fin_timeout) / HZ; 2310 break; 2311 case TCP_DEFER_ACCEPT: 2312 val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 : 2313 ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1)); 2314 break; 2315 case TCP_WINDOW_CLAMP: 2316 val = tp->window_clamp; 2317 break; 2318 case TCP_INFO: { 2319 struct tcp_info info; 2320 2321 if (get_user(len, optlen)) 2322 return -EFAULT; 2323 2324 tcp_get_info(sk, &info); 2325 2326 len = min_t(unsigned int, len, sizeof(info)); 2327 if (put_user(len, optlen)) 2328 return -EFAULT; 2329 if (copy_to_user(optval, &info, len)) 2330 return -EFAULT; 2331 return 0; 2332 } 2333 case TCP_QUICKACK: 2334 val = !icsk->icsk_ack.pingpong; 2335 break; 2336 2337 case TCP_CONGESTION: 2338 if (get_user(len, optlen)) 2339 return -EFAULT; 2340 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 2341 if (put_user(len, optlen)) 2342 return -EFAULT; 2343 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 2344 return -EFAULT; 2345 return 0; 2346 default: 2347 return -ENOPROTOOPT; 2348 } 2349 2350 if (put_user(len, optlen)) 2351 return -EFAULT; 2352 if (copy_to_user(optval, &val, len)) 2353 return -EFAULT; 2354 return 0; 2355} 2356 2357int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 2358 int __user *optlen) 2359{ 2360 struct inet_connection_sock *icsk = inet_csk(sk); 2361 2362 if (level != SOL_TCP) 2363 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 2364 optval, optlen); 2365 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2366} 2367 2368#ifdef CONFIG_COMPAT 2369int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 2370 char __user *optval, int __user *optlen) 2371{ 2372 if (level != SOL_TCP) 2373 return inet_csk_compat_getsockopt(sk, level, optname, 2374 optval, optlen); 2375 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2376} 2377 2378EXPORT_SYMBOL(compat_tcp_getsockopt); 2379#endif 2380 2381struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features) 2382{ 2383 struct sk_buff *segs = ERR_PTR(-EINVAL); 2384 struct tcphdr *th; 2385 unsigned thlen; 2386 unsigned int seq; 2387 __be32 delta; 2388 unsigned int oldlen; 2389 unsigned int len; 2390 2391 if (!pskb_may_pull(skb, sizeof(*th))) 2392 goto out; 2393 2394 th = tcp_hdr(skb); 2395 thlen = th->doff * 4; 2396 if (thlen < sizeof(*th)) 2397 goto out; 2398 2399 if (!pskb_may_pull(skb, thlen)) 2400 goto out; 2401 2402 oldlen = (u16)~skb->len; 2403 __skb_pull(skb, thlen); 2404 2405 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2406 /* Packet is from an untrusted source, reset gso_segs. */ 2407 int type = skb_shinfo(skb)->gso_type; 2408 int mss; 2409 2410 if (unlikely(type & 2411 ~(SKB_GSO_TCPV4 | 2412 SKB_GSO_DODGY | 2413 SKB_GSO_TCP_ECN | 2414 SKB_GSO_TCPV6 | 2415 0) || 2416 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))) 2417 goto out; 2418 2419 mss = skb_shinfo(skb)->gso_size; 2420 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2421 2422 segs = NULL; 2423 goto out; 2424 } 2425 2426 segs = skb_segment(skb, features); 2427 if (IS_ERR(segs)) 2428 goto out; 2429 2430 len = skb_shinfo(skb)->gso_size; 2431 delta = htonl(oldlen + (thlen + len)); 2432 2433 skb = segs; 2434 th = tcp_hdr(skb); 2435 seq = ntohl(th->seq); 2436 2437 do { 2438 th->fin = th->psh = 0; 2439 2440 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2441 (__force u32)delta)); 2442 if (skb->ip_summed != CHECKSUM_PARTIAL) 2443 th->check = 2444 csum_fold(csum_partial(skb_transport_header(skb), 2445 thlen, skb->csum)); 2446 2447 seq += len; 2448 skb = skb->next; 2449 th = tcp_hdr(skb); 2450 2451 th->seq = htonl(seq); 2452 th->cwr = 0; 2453 } while (skb->next); 2454 2455 delta = htonl(oldlen + (skb->tail - skb->transport_header) + 2456 skb->data_len); 2457 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2458 (__force u32)delta)); 2459 if (skb->ip_summed != CHECKSUM_PARTIAL) 2460 th->check = csum_fold(csum_partial(skb_transport_header(skb), 2461 thlen, skb->csum)); 2462 2463out: 2464 return segs; 2465} 2466EXPORT_SYMBOL(tcp_tso_segment); 2467 2468struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) 2469{ 2470 struct sk_buff **pp = NULL; 2471 struct sk_buff *p; 2472 struct tcphdr *th; 2473 struct tcphdr *th2; 2474 unsigned int thlen; 2475 unsigned int flags; 2476 unsigned int total; 2477 unsigned int mss = 1; 2478 int flush = 1; 2479 2480 if (!pskb_may_pull(skb, sizeof(*th))) 2481 goto out; 2482 2483 th = tcp_hdr(skb); 2484 thlen = th->doff * 4; 2485 if (thlen < sizeof(*th)) 2486 goto out; 2487 2488 if (!pskb_may_pull(skb, thlen)) 2489 goto out; 2490 2491 th = tcp_hdr(skb); 2492 __skb_pull(skb, thlen); 2493 2494 flags = tcp_flag_word(th); 2495 2496 for (; (p = *head); head = &p->next) { 2497 if (!NAPI_GRO_CB(p)->same_flow) 2498 continue; 2499 2500 th2 = tcp_hdr(p); 2501 2502 if (th->source != th2->source || th->dest != th2->dest) { 2503 NAPI_GRO_CB(p)->same_flow = 0; 2504 continue; 2505 } 2506 2507 goto found; 2508 } 2509 2510 goto out_check_final; 2511 2512found: 2513 flush = NAPI_GRO_CB(p)->flush; 2514 flush |= flags & TCP_FLAG_CWR; 2515 flush |= (flags ^ tcp_flag_word(th2)) & 2516 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH); 2517 flush |= th->ack_seq != th2->ack_seq || th->window != th2->window; 2518 flush |= memcmp(th + 1, th2 + 1, thlen - sizeof(*th)); 2519 2520 total = p->len; 2521 mss = total; 2522 if (skb_shinfo(p)->frag_list) 2523 mss = skb_shinfo(p)->frag_list->len; 2524 2525 flush |= skb->len > mss || skb->len <= 0; 2526 flush |= ntohl(th2->seq) + total != ntohl(th->seq); 2527 2528 if (flush || skb_gro_receive(head, skb)) { 2529 mss = 1; 2530 goto out_check_final; 2531 } 2532 2533 p = *head; 2534 th2 = tcp_hdr(p); 2535 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); 2536 2537out_check_final: 2538 flush = skb->len < mss; 2539 flush |= flags & (TCP_FLAG_URG | TCP_FLAG_PSH | TCP_FLAG_RST | 2540 TCP_FLAG_SYN | TCP_FLAG_FIN); 2541 2542 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush)) 2543 pp = head; 2544 2545out: 2546 NAPI_GRO_CB(skb)->flush |= flush; 2547 2548 return pp; 2549} 2550 2551int tcp_gro_complete(struct sk_buff *skb) 2552{ 2553 struct tcphdr *th = tcp_hdr(skb); 2554 2555 skb->csum_start = skb_transport_header(skb) - skb->head; 2556 skb->csum_offset = offsetof(struct tcphdr, check); 2557 skb->ip_summed = CHECKSUM_PARTIAL; 2558 2559 skb_shinfo(skb)->gso_size = skb_shinfo(skb)->frag_list->len; 2560 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 2561 2562 if (th->cwr) 2563 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 2564 2565 return 0; 2566} 2567 2568#ifdef CONFIG_TCP_MD5SIG 2569static unsigned long tcp_md5sig_users; 2570static struct tcp_md5sig_pool **tcp_md5sig_pool; 2571static DEFINE_SPINLOCK(tcp_md5sig_pool_lock); 2572 2573static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool) 2574{ 2575 int cpu; 2576 for_each_possible_cpu(cpu) { 2577 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu); 2578 if (p) { 2579 if (p->md5_desc.tfm) 2580 crypto_free_hash(p->md5_desc.tfm); 2581 kfree(p); 2582 p = NULL; 2583 } 2584 } 2585 free_percpu(pool); 2586} 2587 2588void tcp_free_md5sig_pool(void) 2589{ 2590 struct tcp_md5sig_pool **pool = NULL; 2591 2592 spin_lock_bh(&tcp_md5sig_pool_lock); 2593 if (--tcp_md5sig_users == 0) { 2594 pool = tcp_md5sig_pool; 2595 tcp_md5sig_pool = NULL; 2596 } 2597 spin_unlock_bh(&tcp_md5sig_pool_lock); 2598 if (pool) 2599 __tcp_free_md5sig_pool(pool); 2600} 2601 2602EXPORT_SYMBOL(tcp_free_md5sig_pool); 2603 2604static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void) 2605{ 2606 int cpu; 2607 struct tcp_md5sig_pool **pool; 2608 2609 pool = alloc_percpu(struct tcp_md5sig_pool *); 2610 if (!pool) 2611 return NULL; 2612 2613 for_each_possible_cpu(cpu) { 2614 struct tcp_md5sig_pool *p; 2615 struct crypto_hash *hash; 2616 2617 p = kzalloc(sizeof(*p), GFP_KERNEL); 2618 if (!p) 2619 goto out_free; 2620 *per_cpu_ptr(pool, cpu) = p; 2621 2622 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 2623 if (!hash || IS_ERR(hash)) 2624 goto out_free; 2625 2626 p->md5_desc.tfm = hash; 2627 } 2628 return pool; 2629out_free: 2630 __tcp_free_md5sig_pool(pool); 2631 return NULL; 2632} 2633 2634struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void) 2635{ 2636 struct tcp_md5sig_pool **pool; 2637 int alloc = 0; 2638 2639retry: 2640 spin_lock_bh(&tcp_md5sig_pool_lock); 2641 pool = tcp_md5sig_pool; 2642 if (tcp_md5sig_users++ == 0) { 2643 alloc = 1; 2644 spin_unlock_bh(&tcp_md5sig_pool_lock); 2645 } else if (!pool) { 2646 tcp_md5sig_users--; 2647 spin_unlock_bh(&tcp_md5sig_pool_lock); 2648 cpu_relax(); 2649 goto retry; 2650 } else 2651 spin_unlock_bh(&tcp_md5sig_pool_lock); 2652 2653 if (alloc) { 2654 /* we cannot hold spinlock here because this may sleep. */ 2655 struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool(); 2656 spin_lock_bh(&tcp_md5sig_pool_lock); 2657 if (!p) { 2658 tcp_md5sig_users--; 2659 spin_unlock_bh(&tcp_md5sig_pool_lock); 2660 return NULL; 2661 } 2662 pool = tcp_md5sig_pool; 2663 if (pool) { 2664 /* oops, it has already been assigned. */ 2665 spin_unlock_bh(&tcp_md5sig_pool_lock); 2666 __tcp_free_md5sig_pool(p); 2667 } else { 2668 tcp_md5sig_pool = pool = p; 2669 spin_unlock_bh(&tcp_md5sig_pool_lock); 2670 } 2671 } 2672 return pool; 2673} 2674 2675EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 2676 2677struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu) 2678{ 2679 struct tcp_md5sig_pool **p; 2680 spin_lock_bh(&tcp_md5sig_pool_lock); 2681 p = tcp_md5sig_pool; 2682 if (p) 2683 tcp_md5sig_users++; 2684 spin_unlock_bh(&tcp_md5sig_pool_lock); 2685 return (p ? *per_cpu_ptr(p, cpu) : NULL); 2686} 2687 2688EXPORT_SYMBOL(__tcp_get_md5sig_pool); 2689 2690void __tcp_put_md5sig_pool(void) 2691{ 2692 tcp_free_md5sig_pool(); 2693} 2694 2695EXPORT_SYMBOL(__tcp_put_md5sig_pool); 2696 2697int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, 2698 struct tcphdr *th) 2699{ 2700 struct scatterlist sg; 2701 int err; 2702 2703 __sum16 old_checksum = th->check; 2704 th->check = 0; 2705 /* options aren't included in the hash */ 2706 sg_init_one(&sg, th, sizeof(struct tcphdr)); 2707 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr)); 2708 th->check = old_checksum; 2709 return err; 2710} 2711 2712EXPORT_SYMBOL(tcp_md5_hash_header); 2713 2714int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 2715 struct sk_buff *skb, unsigned header_len) 2716{ 2717 struct scatterlist sg; 2718 const struct tcphdr *tp = tcp_hdr(skb); 2719 struct hash_desc *desc = &hp->md5_desc; 2720 unsigned i; 2721 const unsigned head_data_len = skb_headlen(skb) > header_len ? 2722 skb_headlen(skb) - header_len : 0; 2723 const struct skb_shared_info *shi = skb_shinfo(skb); 2724 2725 sg_init_table(&sg, 1); 2726 2727 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 2728 if (crypto_hash_update(desc, &sg, head_data_len)) 2729 return 1; 2730 2731 for (i = 0; i < shi->nr_frags; ++i) { 2732 const struct skb_frag_struct *f = &shi->frags[i]; 2733 sg_set_page(&sg, f->page, f->size, f->page_offset); 2734 if (crypto_hash_update(desc, &sg, f->size)) 2735 return 1; 2736 } 2737 2738 return 0; 2739} 2740 2741EXPORT_SYMBOL(tcp_md5_hash_skb_data); 2742 2743int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key) 2744{ 2745 struct scatterlist sg; 2746 2747 sg_init_one(&sg, key->key, key->keylen); 2748 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); 2749} 2750 2751EXPORT_SYMBOL(tcp_md5_hash_key); 2752 2753#endif 2754 2755void tcp_done(struct sock *sk) 2756{ 2757 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 2758 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 2759 2760 tcp_set_state(sk, TCP_CLOSE); 2761 tcp_clear_xmit_timers(sk); 2762 2763 sk->sk_shutdown = SHUTDOWN_MASK; 2764 2765 if (!sock_flag(sk, SOCK_DEAD)) 2766 sk->sk_state_change(sk); 2767 else 2768 inet_csk_destroy_sock(sk); 2769} 2770EXPORT_SYMBOL_GPL(tcp_done); 2771 2772extern struct tcp_congestion_ops tcp_reno; 2773 2774static __initdata unsigned long thash_entries; 2775static int __init set_thash_entries(char *str) 2776{ 2777 if (!str) 2778 return 0; 2779 thash_entries = simple_strtoul(str, &str, 0); 2780 return 1; 2781} 2782__setup("thash_entries=", set_thash_entries); 2783 2784void __init tcp_init(void) 2785{ 2786 struct sk_buff *skb = NULL; 2787 unsigned long nr_pages, limit; 2788 int order, i, max_share; 2789 2790 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); 2791 2792 percpu_counter_init(&tcp_sockets_allocated, 0); 2793 percpu_counter_init(&tcp_orphan_count, 0); 2794 tcp_hashinfo.bind_bucket_cachep = 2795 kmem_cache_create("tcp_bind_bucket", 2796 sizeof(struct inet_bind_bucket), 0, 2797 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2798 2799 /* Size and allocate the main established and bind bucket 2800 * hash tables. 2801 * 2802 * The methodology is similar to that of the buffer cache. 2803 */ 2804 tcp_hashinfo.ehash = 2805 alloc_large_system_hash("TCP established", 2806 sizeof(struct inet_ehash_bucket), 2807 thash_entries, 2808 (num_physpages >= 128 * 1024) ? 2809 13 : 15, 2810 0, 2811 &tcp_hashinfo.ehash_size, 2812 NULL, 2813 thash_entries ? 0 : 512 * 1024); 2814 tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size; 2815 for (i = 0; i < tcp_hashinfo.ehash_size; i++) { 2816 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 2817 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i); 2818 } 2819 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 2820 panic("TCP: failed to alloc ehash_locks"); 2821 tcp_hashinfo.bhash = 2822 alloc_large_system_hash("TCP bind", 2823 sizeof(struct inet_bind_hashbucket), 2824 tcp_hashinfo.ehash_size, 2825 (num_physpages >= 128 * 1024) ? 2826 13 : 15, 2827 0, 2828 &tcp_hashinfo.bhash_size, 2829 NULL, 2830 64 * 1024); 2831 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size; 2832 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 2833 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 2834 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 2835 } 2836 2837 /* Try to be a bit smarter and adjust defaults depending 2838 * on available memory. 2839 */ 2840 for (order = 0; ((1 << order) << PAGE_SHIFT) < 2841 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket)); 2842 order++) 2843 ; 2844 if (order >= 4) { 2845 tcp_death_row.sysctl_max_tw_buckets = 180000; 2846 sysctl_tcp_max_orphans = 4096 << (order - 4); 2847 sysctl_max_syn_backlog = 1024; 2848 } else if (order < 3) { 2849 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order); 2850 sysctl_tcp_max_orphans >>= (3 - order); 2851 sysctl_max_syn_backlog = 128; 2852 } 2853 2854 /* Set the pressure threshold to be a fraction of global memory that 2855 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of 2856 * memory, with a floor of 128 pages. 2857 */ 2858 nr_pages = totalram_pages - totalhigh_pages; 2859 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); 2860 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); 2861 limit = max(limit, 128UL); 2862 sysctl_tcp_mem[0] = limit / 4 * 3; 2863 sysctl_tcp_mem[1] = limit; 2864 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; 2865 2866 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 2867 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7); 2868 max_share = min(4UL*1024*1024, limit); 2869 2870 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 2871 sysctl_tcp_wmem[1] = 16*1024; 2872 sysctl_tcp_wmem[2] = max(64*1024, max_share); 2873 2874 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 2875 sysctl_tcp_rmem[1] = 87380; 2876 sysctl_tcp_rmem[2] = max(87380, max_share); 2877 2878 printk(KERN_INFO "TCP: Hash tables configured " 2879 "(established %d bind %d)\n", 2880 tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size); 2881 2882 tcp_register_congestion_control(&tcp_reno); 2883} 2884 2885EXPORT_SYMBOL(tcp_close); 2886EXPORT_SYMBOL(tcp_disconnect); 2887EXPORT_SYMBOL(tcp_getsockopt); 2888EXPORT_SYMBOL(tcp_ioctl); 2889EXPORT_SYMBOL(tcp_poll); 2890EXPORT_SYMBOL(tcp_read_sock); 2891EXPORT_SYMBOL(tcp_recvmsg); 2892EXPORT_SYMBOL(tcp_sendmsg); 2893EXPORT_SYMBOL(tcp_splice_read); 2894EXPORT_SYMBOL(tcp_sendpage); 2895EXPORT_SYMBOL(tcp_setsockopt); 2896EXPORT_SYMBOL(tcp_shutdown); 2897