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