1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Implementation of the Transmission Control Protocol(TCP). 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Mark Evans, <evansmp@uhura.aston.ac.uk> 11 * Corey Minyard <wf-rch!minyard@relay.EU.net> 12 * Florian La Roche, <flla@stud.uni-sb.de> 13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> 14 * Linus Torvalds, <torvalds@cs.helsinki.fi> 15 * Alan Cox, <gw4pts@gw4pts.ampr.org> 16 * Matthew Dillon, <dillon@apollo.west.oic.com> 17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 18 * Jorge Cwik, <jorge@laser.satlink.net> 19 * 20 * Fixes: 21 * Alan Cox : Numerous verify_area() calls 22 * Alan Cox : Set the ACK bit on a reset 23 * Alan Cox : Stopped it crashing if it closed while 24 * sk->inuse=1 and was trying to connect 25 * (tcp_err()). 26 * Alan Cox : All icmp error handling was broken 27 * pointers passed where wrong and the 28 * socket was looked up backwards. Nobody 29 * tested any icmp error code obviously. 30 * Alan Cox : tcp_err() now handled properly. It 31 * wakes people on errors. poll 32 * behaves and the icmp error race 33 * has gone by moving it into sock.c 34 * Alan Cox : tcp_send_reset() fixed to work for 35 * everything not just packets for 36 * unknown sockets. 37 * Alan Cox : tcp option processing. 38 * Alan Cox : Reset tweaked (still not 100%) [Had 39 * syn rule wrong] 40 * Herp Rosmanith : More reset fixes 41 * Alan Cox : No longer acks invalid rst frames. 42 * Acking any kind of RST is right out. 43 * Alan Cox : Sets an ignore me flag on an rst 44 * receive otherwise odd bits of prattle 45 * escape still 46 * Alan Cox : Fixed another acking RST frame bug. 47 * Should stop LAN workplace lockups. 48 * Alan Cox : Some tidyups using the new skb list 49 * facilities 50 * Alan Cox : sk->keepopen now seems to work 51 * Alan Cox : Pulls options out correctly on accepts 52 * Alan Cox : Fixed assorted sk->rqueue->next errors 53 * Alan Cox : PSH doesn't end a TCP read. Switched a 54 * bit to skb ops. 55 * Alan Cox : Tidied tcp_data to avoid a potential 56 * nasty. 57 * Alan Cox : Added some better commenting, as the 58 * tcp is hard to follow 59 * Alan Cox : Removed incorrect check for 20 * psh 60 * Michael O'Reilly : ack < copied bug fix. 61 * Johannes Stille : Misc tcp fixes (not all in yet). 62 * Alan Cox : FIN with no memory -> CRASH 63 * Alan Cox : Added socket option proto entries. 64 * Also added awareness of them to accept. 65 * Alan Cox : Added TCP options (SOL_TCP) 66 * Alan Cox : Switched wakeup calls to callbacks, 67 * so the kernel can layer network 68 * sockets. 69 * Alan Cox : Use ip_tos/ip_ttl settings. 70 * Alan Cox : Handle FIN (more) properly (we hope). 71 * Alan Cox : RST frames sent on unsynchronised 72 * state ack error. 73 * Alan Cox : Put in missing check for SYN bit. 74 * Alan Cox : Added tcp_select_window() aka NET2E 75 * window non shrink trick. 76 * Alan Cox : Added a couple of small NET2E timer 77 * fixes 78 * Charles Hedrick : TCP fixes 79 * Toomas Tamm : TCP window fixes 80 * Alan Cox : Small URG fix to rlogin ^C ack fight 81 * Charles Hedrick : Rewrote most of it to actually work 82 * Linus : Rewrote tcp_read() and URG handling 83 * completely 84 * Gerhard Koerting: Fixed some missing timer handling 85 * Matthew Dillon : Reworked TCP machine states as per RFC 86 * Gerhard Koerting: PC/TCP workarounds 87 * Adam Caldwell : Assorted timer/timing errors 88 * Matthew Dillon : Fixed another RST bug 89 * Alan Cox : Move to kernel side addressing changes. 90 * Alan Cox : Beginning work on TCP fastpathing 91 * (not yet usable) 92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine. 93 * Alan Cox : TCP fast path debugging 94 * Alan Cox : Window clamping 95 * Michael Riepe : Bug in tcp_check() 96 * Matt Dillon : More TCP improvements and RST bug fixes 97 * Matt Dillon : Yet more small nasties remove from the 98 * TCP code (Be very nice to this man if 99 * tcp finally works 100%) 8) 100 * Alan Cox : BSD accept semantics. 101 * Alan Cox : Reset on closedown bug. 102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto(). 103 * Michael Pall : Handle poll() after URG properly in 104 * all cases. 105 * Michael Pall : Undo the last fix in tcp_read_urg() 106 * (multi URG PUSH broke rlogin). 107 * Michael Pall : Fix the multi URG PUSH problem in 108 * tcp_readable(), poll() after URG 109 * works now. 110 * Michael Pall : recv(...,MSG_OOB) never blocks in the 111 * BSD api. 112 * Alan Cox : Changed the semantics of sk->socket to 113 * fix a race and a signal problem with 114 * accept() and async I/O. 115 * Alan Cox : Relaxed the rules on tcp_sendto(). 116 * Yury Shevchuk : Really fixed accept() blocking problem. 117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for 118 * clients/servers which listen in on 119 * fixed ports. 120 * Alan Cox : Cleaned the above up and shrank it to 121 * a sensible code size. 122 * Alan Cox : Self connect lockup fix. 123 * Alan Cox : No connect to multicast. 124 * Ross Biro : Close unaccepted children on master 125 * socket close. 126 * Alan Cox : Reset tracing code. 127 * Alan Cox : Spurious resets on shutdown. 128 * Alan Cox : Giant 15 minute/60 second timer error 129 * Alan Cox : Small whoops in polling before an 130 * accept. 131 * Alan Cox : Kept the state trace facility since 132 * it's handy for debugging. 133 * Alan Cox : More reset handler fixes. 134 * Alan Cox : Started rewriting the code based on 135 * the RFC's for other useful protocol 136 * references see: Comer, KA9Q NOS, and 137 * for a reference on the difference 138 * between specifications and how BSD 139 * works see the 4.4lite source. 140 * A.N.Kuznetsov : Don't time wait on completion of tidy 141 * close. 142 * Linus Torvalds : Fin/Shutdown & copied_seq changes. 143 * Linus Torvalds : Fixed BSD port reuse to work first syn 144 * Alan Cox : Reimplemented timers as per the RFC 145 * and using multiple timers for sanity. 146 * Alan Cox : Small bug fixes, and a lot of new 147 * comments. 148 * Alan Cox : Fixed dual reader crash by locking 149 * the buffers (much like datagram.c) 150 * Alan Cox : Fixed stuck sockets in probe. A probe 151 * now gets fed up of retrying without 152 * (even a no space) answer. 153 * Alan Cox : Extracted closing code better 154 * Alan Cox : Fixed the closing state machine to 155 * resemble the RFC. 156 * Alan Cox : More 'per spec' fixes. 157 * Jorge Cwik : Even faster checksumming. 158 * Alan Cox : tcp_data() doesn't ack illegal PSH 159 * only frames. At least one pc tcp stack 160 * generates them. 161 * Alan Cox : Cache last socket. 162 * Alan Cox : Per route irtt. 163 * Matt Day : poll()->select() match BSD precisely on error 164 * Alan Cox : New buffers 165 * Marc Tamsky : Various sk->prot->retransmits and 166 * sk->retransmits misupdating fixed. 167 * Fixed tcp_write_timeout: stuck close, 168 * and TCP syn retries gets used now. 169 * Mark Yarvis : In tcp_read_wakeup(), don't send an 170 * ack if state is TCP_CLOSED. 171 * Alan Cox : Look up device on a retransmit - routes may 172 * change. Doesn't yet cope with MSS shrink right 173 * but it's a start! 174 * Marc Tamsky : Closing in closing fixes. 175 * Mike Shaver : RFC1122 verifications. 176 * Alan Cox : rcv_saddr errors. 177 * Alan Cox : Block double connect(). 178 * Alan Cox : Small hooks for enSKIP. 179 * Alexey Kuznetsov: Path MTU discovery. 180 * Alan Cox : Support soft errors. 181 * Alan Cox : Fix MTU discovery pathological case 182 * when the remote claims no mtu! 183 * Marc Tamsky : TCP_CLOSE fix. 184 * Colin (G3TNE) : Send a reset on syn ack replies in 185 * window but wrong (fixes NT lpd problems) 186 * Pedro Roque : Better TCP window handling, delayed ack. 187 * Joerg Reuter : No modification of locked buffers in 188 * tcp_do_retransmit() 189 * Eric Schenk : Changed receiver side silly window 190 * avoidance algorithm to BSD style 191 * algorithm. This doubles throughput 192 * against machines running Solaris, 193 * and seems to result in general 194 * improvement. 195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD 196 * Willy Konynenberg : Transparent proxying support. 197 * Mike McLagan : Routing by source 198 * Keith Owens : Do proper merging with partial SKB's in 199 * tcp_do_sendmsg to avoid burstiness. 200 * Eric Schenk : Fix fast close down bug with 201 * shutdown() followed by close(). 202 * Andi Kleen : Make poll agree with SIGIO 203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and 204 * lingertime == 0 (RFC 793 ABORT Call) 205 * Hirokazu Takahashi : Use copy_from_user() instead of 206 * csum_and_copy_from_user() if possible. 207 * 208 * This program is free software; you can redistribute it and/or 209 * modify it under the terms of the GNU General Public License 210 * as published by the Free Software Foundation; either version 211 * 2 of the License, or(at your option) any later version. 212 * 213 * Description of States: 214 * 215 * TCP_SYN_SENT sent a connection request, waiting for ack 216 * 217 * TCP_SYN_RECV received a connection request, sent ack, 218 * waiting for final ack in three-way handshake. 219 * 220 * TCP_ESTABLISHED connection established 221 * 222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete 223 * transmission of remaining buffered data 224 * 225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote 226 * to shutdown 227 * 228 * TCP_CLOSING both sides have shutdown but we still have 229 * data we have to finish sending 230 * 231 * TCP_TIME_WAIT timeout to catch resent junk before entering 232 * closed, can only be entered from FIN_WAIT2 233 * or CLOSING. Required because the other end 234 * may not have gotten our last ACK causing it 235 * to retransmit the data packet (which we ignore) 236 * 237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for 238 * us to finish writing our data and to shutdown 239 * (we have to close() to move on to LAST_ACK) 240 * 241 * TCP_LAST_ACK out side has shutdown after remote has 242 * shutdown. There may still be data in our 243 * buffer that we have to finish sending 244 * 245 * TCP_CLOSE socket is finished 246 */ 247 248 #define pr_fmt(fmt) "TCP: " fmt 249 250 #include <linux/kernel.h> 251 #include <linux/module.h> 252 #include <linux/types.h> 253 #include <linux/fcntl.h> 254 #include <linux/poll.h> 255 #include <linux/init.h> 256 #include <linux/fs.h> 257 #include <linux/skbuff.h> 258 #include <linux/scatterlist.h> 259 #include <linux/splice.h> 260 #include <linux/net.h> 261 #include <linux/socket.h> 262 #include <linux/random.h> 263 #include <linux/bootmem.h> 264 #include <linux/highmem.h> 265 #include <linux/swap.h> 266 #include <linux/cache.h> 267 #include <linux/err.h> 268 #include <linux/crypto.h> 269 #include <linux/time.h> 270 #include <linux/slab.h> 271 272 #include <net/icmp.h> 273 #include <net/tcp.h> 274 #include <net/xfrm.h> 275 #include <net/ip.h> 276 #include <net/netdma.h> 277 #include <net/sock.h> 278 279 #include <asm/uaccess.h> 280 #include <asm/ioctls.h> 281 282 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; 283 284 struct percpu_counter tcp_orphan_count; 285 EXPORT_SYMBOL_GPL(tcp_orphan_count); 286 287 int sysctl_tcp_wmem[3] __read_mostly; 288 int sysctl_tcp_rmem[3] __read_mostly; 289 290 EXPORT_SYMBOL(sysctl_tcp_rmem); 291 EXPORT_SYMBOL(sysctl_tcp_wmem); 292 293 atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ 294 EXPORT_SYMBOL(tcp_memory_allocated); 295 296 /* 297 * Current number of TCP sockets. 298 */ 299 struct percpu_counter tcp_sockets_allocated; 300 EXPORT_SYMBOL(tcp_sockets_allocated); 301 302 /* 303 * TCP splice context 304 */ 305 struct tcp_splice_state { 306 struct pipe_inode_info *pipe; 307 size_t len; 308 unsigned int flags; 309 }; 310 311 /* 312 * Pressure flag: try to collapse. 313 * Technical note: it is used by multiple contexts non atomically. 314 * All the __sk_mem_schedule() is of this nature: accounting 315 * is strict, actions are advisory and have some latency. 316 */ 317 int tcp_memory_pressure __read_mostly; 318 EXPORT_SYMBOL(tcp_memory_pressure); 319 320 void tcp_enter_memory_pressure(struct sock *sk) 321 { 322 if (!tcp_memory_pressure) { 323 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); 324 tcp_memory_pressure = 1; 325 } 326 } 327 EXPORT_SYMBOL(tcp_enter_memory_pressure); 328 329 /* Convert seconds to retransmits based on initial and max timeout */ 330 static u8 secs_to_retrans(int seconds, int timeout, int rto_max) 331 { 332 u8 res = 0; 333 334 if (seconds > 0) { 335 int period = timeout; 336 337 res = 1; 338 while (seconds > period && res < 255) { 339 res++; 340 timeout <<= 1; 341 if (timeout > rto_max) 342 timeout = rto_max; 343 period += timeout; 344 } 345 } 346 return res; 347 } 348 349 /* Convert retransmits to seconds based on initial and max timeout */ 350 static int retrans_to_secs(u8 retrans, int timeout, int rto_max) 351 { 352 int period = 0; 353 354 if (retrans > 0) { 355 period = timeout; 356 while (--retrans) { 357 timeout <<= 1; 358 if (timeout > rto_max) 359 timeout = rto_max; 360 period += timeout; 361 } 362 } 363 return period; 364 } 365 366 /* 367 * Wait for a TCP event. 368 * 369 * Note that we don't need to lock the socket, as the upper poll layers 370 * take care of normal races (between the test and the event) and we don't 371 * go look at any of the socket buffers directly. 372 */ 373 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 374 { 375 unsigned int mask; 376 struct sock *sk = sock->sk; 377 const struct tcp_sock *tp = tcp_sk(sk); 378 379 sock_poll_wait(file, sk_sleep(sk), wait); 380 if (sk->sk_state == TCP_LISTEN) 381 return inet_csk_listen_poll(sk); 382 383 /* Socket is not locked. We are protected from async events 384 * by poll logic and correct handling of state changes 385 * made by other threads is impossible in any case. 386 */ 387 388 mask = 0; 389 390 /* 391 * POLLHUP is certainly not done right. But poll() doesn't 392 * have a notion of HUP in just one direction, and for a 393 * socket the read side is more interesting. 394 * 395 * Some poll() documentation says that POLLHUP is incompatible 396 * with the POLLOUT/POLLWR flags, so somebody should check this 397 * all. But careful, it tends to be safer to return too many 398 * bits than too few, and you can easily break real applications 399 * if you don't tell them that something has hung up! 400 * 401 * Check-me. 402 * 403 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and 404 * our fs/select.c). It means that after we received EOF, 405 * poll always returns immediately, making impossible poll() on write() 406 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP 407 * if and only if shutdown has been made in both directions. 408 * Actually, it is interesting to look how Solaris and DUX 409 * solve this dilemma. I would prefer, if POLLHUP were maskable, 410 * then we could set it on SND_SHUTDOWN. BTW examples given 411 * in Stevens' books assume exactly this behaviour, it explains 412 * why POLLHUP is incompatible with POLLOUT. --ANK 413 * 414 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 415 * blocking on fresh not-connected or disconnected socket. --ANK 416 */ 417 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) 418 mask |= POLLHUP; 419 if (sk->sk_shutdown & RCV_SHUTDOWN) 420 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 421 422 /* Connected? */ 423 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { 424 int target = sock_rcvlowat(sk, 0, INT_MAX); 425 426 if (tp->urg_seq == tp->copied_seq && 427 !sock_flag(sk, SOCK_URGINLINE) && 428 tp->urg_data) 429 target++; 430 431 /* Potential race condition. If read of tp below will 432 * escape above sk->sk_state, we can be illegally awaken 433 * in SYN_* states. */ 434 if (tp->rcv_nxt - tp->copied_seq >= target) 435 mask |= POLLIN | POLLRDNORM; 436 437 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 438 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 439 mask |= POLLOUT | POLLWRNORM; 440 } else { /* send SIGIO later */ 441 set_bit(SOCK_ASYNC_NOSPACE, 442 &sk->sk_socket->flags); 443 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 444 445 /* Race breaker. If space is freed after 446 * wspace test but before the flags are set, 447 * IO signal will be lost. 448 */ 449 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) 450 mask |= POLLOUT | POLLWRNORM; 451 } 452 } else 453 mask |= POLLOUT | POLLWRNORM; 454 455 if (tp->urg_data & TCP_URG_VALID) 456 mask |= POLLPRI; 457 } 458 /* This barrier is coupled with smp_wmb() in tcp_reset() */ 459 smp_rmb(); 460 if (sk->sk_err) 461 mask |= POLLERR; 462 463 return mask; 464 } 465 EXPORT_SYMBOL(tcp_poll); 466 467 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 468 { 469 struct tcp_sock *tp = tcp_sk(sk); 470 int answ; 471 472 switch (cmd) { 473 case SIOCINQ: 474 if (sk->sk_state == TCP_LISTEN) 475 return -EINVAL; 476 477 lock_sock(sk); 478 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 479 answ = 0; 480 else if (sock_flag(sk, SOCK_URGINLINE) || 481 !tp->urg_data || 482 before(tp->urg_seq, tp->copied_seq) || 483 !before(tp->urg_seq, tp->rcv_nxt)) { 484 struct sk_buff *skb; 485 486 answ = tp->rcv_nxt - tp->copied_seq; 487 488 /* Subtract 1, if FIN is in queue. */ 489 skb = skb_peek_tail(&sk->sk_receive_queue); 490 if (answ && skb) 491 answ -= tcp_hdr(skb)->fin; 492 } else 493 answ = tp->urg_seq - tp->copied_seq; 494 release_sock(sk); 495 break; 496 case SIOCATMARK: 497 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 498 break; 499 case SIOCOUTQ: 500 if (sk->sk_state == TCP_LISTEN) 501 return -EINVAL; 502 503 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 504 answ = 0; 505 else 506 answ = tp->write_seq - tp->snd_una; 507 break; 508 case SIOCOUTQNSD: 509 if (sk->sk_state == TCP_LISTEN) 510 return -EINVAL; 511 512 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 513 answ = 0; 514 else 515 answ = tp->write_seq - tp->snd_nxt; 516 break; 517 default: 518 return -ENOIOCTLCMD; 519 } 520 521 return put_user(answ, (int __user *)arg); 522 } 523 EXPORT_SYMBOL(tcp_ioctl); 524 525 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 526 { 527 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; 528 tp->pushed_seq = tp->write_seq; 529 } 530 531 static inline int forced_push(const struct tcp_sock *tp) 532 { 533 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 534 } 535 536 static inline void skb_entail(struct sock *sk, struct sk_buff *skb) 537 { 538 struct tcp_sock *tp = tcp_sk(sk); 539 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 540 541 skb->csum = 0; 542 tcb->seq = tcb->end_seq = tp->write_seq; 543 tcb->tcp_flags = TCPHDR_ACK; 544 tcb->sacked = 0; 545 skb_header_release(skb); 546 tcp_add_write_queue_tail(sk, skb); 547 sk->sk_wmem_queued += skb->truesize; 548 sk_mem_charge(sk, skb->truesize); 549 if (tp->nonagle & TCP_NAGLE_PUSH) 550 tp->nonagle &= ~TCP_NAGLE_PUSH; 551 } 552 553 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) 554 { 555 if (flags & MSG_OOB) 556 tp->snd_up = tp->write_seq; 557 } 558 559 static inline void tcp_push(struct sock *sk, int flags, int mss_now, 560 int nonagle) 561 { 562 if (tcp_send_head(sk)) { 563 struct tcp_sock *tp = tcp_sk(sk); 564 565 if (!(flags & MSG_MORE) || forced_push(tp)) 566 tcp_mark_push(tp, tcp_write_queue_tail(sk)); 567 568 tcp_mark_urg(tp, flags); 569 __tcp_push_pending_frames(sk, mss_now, 570 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); 571 } 572 } 573 574 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 575 unsigned int offset, size_t len) 576 { 577 struct tcp_splice_state *tss = rd_desc->arg.data; 578 int ret; 579 580 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len), 581 tss->flags); 582 if (ret > 0) 583 rd_desc->count -= ret; 584 return ret; 585 } 586 587 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 588 { 589 /* Store TCP splice context information in read_descriptor_t. */ 590 read_descriptor_t rd_desc = { 591 .arg.data = tss, 592 .count = tss->len, 593 }; 594 595 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 596 } 597 598 /** 599 * tcp_splice_read - splice data from TCP socket to a pipe 600 * @sock: socket to splice from 601 * @ppos: position (not valid) 602 * @pipe: pipe to splice to 603 * @len: number of bytes to splice 604 * @flags: splice modifier flags 605 * 606 * Description: 607 * Will read pages from given socket and fill them into a pipe. 608 * 609 **/ 610 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 611 struct pipe_inode_info *pipe, size_t len, 612 unsigned int flags) 613 { 614 struct sock *sk = sock->sk; 615 struct tcp_splice_state tss = { 616 .pipe = pipe, 617 .len = len, 618 .flags = flags, 619 }; 620 long timeo; 621 ssize_t spliced; 622 int ret; 623 624 sock_rps_record_flow(sk); 625 /* 626 * We can't seek on a socket input 627 */ 628 if (unlikely(*ppos)) 629 return -ESPIPE; 630 631 ret = spliced = 0; 632 633 lock_sock(sk); 634 635 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); 636 while (tss.len) { 637 ret = __tcp_splice_read(sk, &tss); 638 if (ret < 0) 639 break; 640 else if (!ret) { 641 if (spliced) 642 break; 643 if (sock_flag(sk, SOCK_DONE)) 644 break; 645 if (sk->sk_err) { 646 ret = sock_error(sk); 647 break; 648 } 649 if (sk->sk_shutdown & RCV_SHUTDOWN) 650 break; 651 if (sk->sk_state == TCP_CLOSE) { 652 /* 653 * This occurs when user tries to read 654 * from never connected socket. 655 */ 656 if (!sock_flag(sk, SOCK_DONE)) 657 ret = -ENOTCONN; 658 break; 659 } 660 if (!timeo) { 661 ret = -EAGAIN; 662 break; 663 } 664 sk_wait_data(sk, &timeo); 665 if (signal_pending(current)) { 666 ret = sock_intr_errno(timeo); 667 break; 668 } 669 continue; 670 } 671 tss.len -= ret; 672 spliced += ret; 673 674 if (!timeo) 675 break; 676 release_sock(sk); 677 lock_sock(sk); 678 679 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 680 (sk->sk_shutdown & RCV_SHUTDOWN) || 681 signal_pending(current)) 682 break; 683 } 684 685 release_sock(sk); 686 687 if (spliced) 688 return spliced; 689 690 return ret; 691 } 692 EXPORT_SYMBOL(tcp_splice_read); 693 694 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) 695 { 696 struct sk_buff *skb; 697 698 /* The TCP header must be at least 32-bit aligned. */ 699 size = ALIGN(size, 4); 700 701 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 702 if (skb) { 703 if (sk_wmem_schedule(sk, skb->truesize)) { 704 skb_reserve(skb, sk->sk_prot->max_header); 705 /* 706 * Make sure that we have exactly size bytes 707 * available to the caller, no more, no less. 708 */ 709 skb->avail_size = size; 710 return skb; 711 } 712 __kfree_skb(skb); 713 } else { 714 sk->sk_prot->enter_memory_pressure(sk); 715 sk_stream_moderate_sndbuf(sk); 716 } 717 return NULL; 718 } 719 720 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, 721 int large_allowed) 722 { 723 struct tcp_sock *tp = tcp_sk(sk); 724 u32 xmit_size_goal, old_size_goal; 725 726 xmit_size_goal = mss_now; 727 728 if (large_allowed && sk_can_gso(sk)) { 729 xmit_size_goal = ((sk->sk_gso_max_size - 1) - 730 inet_csk(sk)->icsk_af_ops->net_header_len - 731 inet_csk(sk)->icsk_ext_hdr_len - 732 tp->tcp_header_len); 733 734 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal); 735 736 /* We try hard to avoid divides here */ 737 old_size_goal = tp->xmit_size_goal_segs * mss_now; 738 739 if (likely(old_size_goal <= xmit_size_goal && 740 old_size_goal + mss_now > xmit_size_goal)) { 741 xmit_size_goal = old_size_goal; 742 } else { 743 tp->xmit_size_goal_segs = xmit_size_goal / mss_now; 744 xmit_size_goal = tp->xmit_size_goal_segs * mss_now; 745 } 746 } 747 748 return max(xmit_size_goal, mss_now); 749 } 750 751 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) 752 { 753 int mss_now; 754 755 mss_now = tcp_current_mss(sk); 756 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); 757 758 return mss_now; 759 } 760 761 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, 762 size_t psize, int flags) 763 { 764 struct tcp_sock *tp = tcp_sk(sk); 765 int mss_now, size_goal; 766 int err; 767 ssize_t copied; 768 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 769 770 /* Wait for a connection to finish. */ 771 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 772 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 773 goto out_err; 774 775 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 776 777 mss_now = tcp_send_mss(sk, &size_goal, flags); 778 copied = 0; 779 780 err = -EPIPE; 781 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 782 goto out_err; 783 784 while (psize > 0) { 785 struct sk_buff *skb = tcp_write_queue_tail(sk); 786 struct page *page = pages[poffset / PAGE_SIZE]; 787 int copy, i, can_coalesce; 788 int offset = poffset % PAGE_SIZE; 789 int size = min_t(size_t, psize, PAGE_SIZE - offset); 790 791 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { 792 new_segment: 793 if (!sk_stream_memory_free(sk)) 794 goto wait_for_sndbuf; 795 796 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); 797 if (!skb) 798 goto wait_for_memory; 799 800 skb_entail(sk, skb); 801 copy = size_goal; 802 } 803 804 if (copy > size) 805 copy = size; 806 807 i = skb_shinfo(skb)->nr_frags; 808 can_coalesce = skb_can_coalesce(skb, i, page, offset); 809 if (!can_coalesce && i >= MAX_SKB_FRAGS) { 810 tcp_mark_push(tp, skb); 811 goto new_segment; 812 } 813 if (!sk_wmem_schedule(sk, copy)) 814 goto wait_for_memory; 815 816 if (can_coalesce) { 817 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 818 } else { 819 get_page(page); 820 skb_fill_page_desc(skb, i, page, offset, copy); 821 } 822 823 skb->len += copy; 824 skb->data_len += copy; 825 skb->truesize += copy; 826 sk->sk_wmem_queued += copy; 827 sk_mem_charge(sk, copy); 828 skb->ip_summed = CHECKSUM_PARTIAL; 829 tp->write_seq += copy; 830 TCP_SKB_CB(skb)->end_seq += copy; 831 skb_shinfo(skb)->gso_segs = 0; 832 833 if (!copied) 834 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 835 836 copied += copy; 837 poffset += copy; 838 if (!(psize -= copy)) 839 goto out; 840 841 if (skb->len < size_goal || (flags & MSG_OOB)) 842 continue; 843 844 if (forced_push(tp)) { 845 tcp_mark_push(tp, skb); 846 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 847 } else if (skb == tcp_send_head(sk)) 848 tcp_push_one(sk, mss_now); 849 continue; 850 851 wait_for_sndbuf: 852 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 853 wait_for_memory: 854 if (copied) 855 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 856 857 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 858 goto do_error; 859 860 mss_now = tcp_send_mss(sk, &size_goal, flags); 861 } 862 863 out: 864 if (copied && !(flags & MSG_SENDPAGE_NOTLAST)) 865 tcp_push(sk, flags, mss_now, tp->nonagle); 866 return copied; 867 868 do_error: 869 if (copied) 870 goto out; 871 out_err: 872 return sk_stream_error(sk, flags, err); 873 } 874 875 int tcp_sendpage(struct sock *sk, struct page *page, int offset, 876 size_t size, int flags) 877 { 878 ssize_t res; 879 880 if (!(sk->sk_route_caps & NETIF_F_SG) || 881 !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) 882 return sock_no_sendpage(sk->sk_socket, page, offset, size, 883 flags); 884 885 lock_sock(sk); 886 res = do_tcp_sendpages(sk, &page, offset, size, flags); 887 release_sock(sk); 888 return res; 889 } 890 EXPORT_SYMBOL(tcp_sendpage); 891 892 static inline int select_size(const struct sock *sk, bool sg) 893 { 894 const struct tcp_sock *tp = tcp_sk(sk); 895 int tmp = tp->mss_cache; 896 897 if (sg) { 898 if (sk_can_gso(sk)) { 899 /* Small frames wont use a full page: 900 * Payload will immediately follow tcp header. 901 */ 902 tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER); 903 } else { 904 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); 905 906 if (tmp >= pgbreak && 907 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) 908 tmp = pgbreak; 909 } 910 } 911 912 return tmp; 913 } 914 915 int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 916 size_t size) 917 { 918 struct iovec *iov; 919 struct tcp_sock *tp = tcp_sk(sk); 920 struct sk_buff *skb; 921 int iovlen, flags, err, copied; 922 int mss_now, size_goal; 923 bool sg; 924 long timeo; 925 926 lock_sock(sk); 927 928 flags = msg->msg_flags; 929 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 930 931 /* Wait for a connection to finish. */ 932 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 933 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 934 goto out_err; 935 936 /* This should be in poll */ 937 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 938 939 mss_now = tcp_send_mss(sk, &size_goal, flags); 940 941 /* Ok commence sending. */ 942 iovlen = msg->msg_iovlen; 943 iov = msg->msg_iov; 944 copied = 0; 945 946 err = -EPIPE; 947 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 948 goto out_err; 949 950 sg = !!(sk->sk_route_caps & NETIF_F_SG); 951 952 while (--iovlen >= 0) { 953 size_t seglen = iov->iov_len; 954 unsigned char __user *from = iov->iov_base; 955 956 iov++; 957 958 while (seglen > 0) { 959 int copy = 0; 960 int max = size_goal; 961 962 skb = tcp_write_queue_tail(sk); 963 if (tcp_send_head(sk)) { 964 if (skb->ip_summed == CHECKSUM_NONE) 965 max = mss_now; 966 copy = max - skb->len; 967 } 968 969 if (copy <= 0) { 970 new_segment: 971 /* Allocate new segment. If the interface is SG, 972 * allocate skb fitting to single page. 973 */ 974 if (!sk_stream_memory_free(sk)) 975 goto wait_for_sndbuf; 976 977 skb = sk_stream_alloc_skb(sk, 978 select_size(sk, sg), 979 sk->sk_allocation); 980 if (!skb) 981 goto wait_for_memory; 982 983 /* 984 * Check whether we can use HW checksum. 985 */ 986 if (sk->sk_route_caps & NETIF_F_ALL_CSUM) 987 skb->ip_summed = CHECKSUM_PARTIAL; 988 989 skb_entail(sk, skb); 990 copy = size_goal; 991 max = size_goal; 992 } 993 994 /* Try to append data to the end of skb. */ 995 if (copy > seglen) 996 copy = seglen; 997 998 /* Where to copy to? */ 999 if (skb_availroom(skb) > 0) { 1000 /* We have some space in skb head. Superb! */ 1001 copy = min_t(int, copy, skb_availroom(skb)); 1002 err = skb_add_data_nocache(sk, skb, from, copy); 1003 if (err) 1004 goto do_fault; 1005 } else { 1006 int merge = 0; 1007 int i = skb_shinfo(skb)->nr_frags; 1008 struct page *page = sk->sk_sndmsg_page; 1009 int off; 1010 1011 if (page && page_count(page) == 1) 1012 sk->sk_sndmsg_off = 0; 1013 1014 off = sk->sk_sndmsg_off; 1015 1016 if (skb_can_coalesce(skb, i, page, off) && 1017 off != PAGE_SIZE) { 1018 /* We can extend the last page 1019 * fragment. */ 1020 merge = 1; 1021 } else if (i == MAX_SKB_FRAGS || !sg) { 1022 /* Need to add new fragment and cannot 1023 * do this because interface is non-SG, 1024 * or because all the page slots are 1025 * busy. */ 1026 tcp_mark_push(tp, skb); 1027 goto new_segment; 1028 } else if (page) { 1029 if (off == PAGE_SIZE) { 1030 put_page(page); 1031 sk->sk_sndmsg_page = page = NULL; 1032 off = 0; 1033 } 1034 } else 1035 off = 0; 1036 1037 if (copy > PAGE_SIZE - off) 1038 copy = PAGE_SIZE - off; 1039 1040 if (!sk_wmem_schedule(sk, copy)) 1041 goto wait_for_memory; 1042 1043 if (!page) { 1044 /* Allocate new cache page. */ 1045 if (!(page = sk_stream_alloc_page(sk))) 1046 goto wait_for_memory; 1047 } 1048 1049 /* Time to copy data. We are close to 1050 * the end! */ 1051 err = skb_copy_to_page_nocache(sk, from, skb, 1052 page, off, copy); 1053 if (err) { 1054 /* If this page was new, give it to the 1055 * socket so it does not get leaked. 1056 */ 1057 if (!sk->sk_sndmsg_page) { 1058 sk->sk_sndmsg_page = page; 1059 sk->sk_sndmsg_off = 0; 1060 } 1061 goto do_error; 1062 } 1063 1064 /* Update the skb. */ 1065 if (merge) { 1066 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1067 } else { 1068 skb_fill_page_desc(skb, i, page, off, copy); 1069 if (sk->sk_sndmsg_page) { 1070 get_page(page); 1071 } else if (off + copy < PAGE_SIZE) { 1072 get_page(page); 1073 sk->sk_sndmsg_page = page; 1074 } 1075 } 1076 1077 sk->sk_sndmsg_off = off + copy; 1078 } 1079 1080 if (!copied) 1081 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 1082 1083 tp->write_seq += copy; 1084 TCP_SKB_CB(skb)->end_seq += copy; 1085 skb_shinfo(skb)->gso_segs = 0; 1086 1087 from += copy; 1088 copied += copy; 1089 if ((seglen -= copy) == 0 && iovlen == 0) 1090 goto out; 1091 1092 if (skb->len < max || (flags & MSG_OOB)) 1093 continue; 1094 1095 if (forced_push(tp)) { 1096 tcp_mark_push(tp, skb); 1097 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1098 } else if (skb == tcp_send_head(sk)) 1099 tcp_push_one(sk, mss_now); 1100 continue; 1101 1102 wait_for_sndbuf: 1103 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1104 wait_for_memory: 1105 if (copied) 1106 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 1107 1108 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 1109 goto do_error; 1110 1111 mss_now = tcp_send_mss(sk, &size_goal, flags); 1112 } 1113 } 1114 1115 out: 1116 if (copied) 1117 tcp_push(sk, flags, mss_now, tp->nonagle); 1118 release_sock(sk); 1119 return copied; 1120 1121 do_fault: 1122 if (!skb->len) { 1123 tcp_unlink_write_queue(skb, sk); 1124 /* It is the one place in all of TCP, except connection 1125 * reset, where we can be unlinking the send_head. 1126 */ 1127 tcp_check_send_head(sk, skb); 1128 sk_wmem_free_skb(sk, skb); 1129 } 1130 1131 do_error: 1132 if (copied) 1133 goto out; 1134 out_err: 1135 err = sk_stream_error(sk, flags, err); 1136 release_sock(sk); 1137 return err; 1138 } 1139 EXPORT_SYMBOL(tcp_sendmsg); 1140 1141 /* 1142 * Handle reading urgent data. BSD has very simple semantics for 1143 * this, no blocking and very strange errors 8) 1144 */ 1145 1146 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) 1147 { 1148 struct tcp_sock *tp = tcp_sk(sk); 1149 1150 /* No URG data to read. */ 1151 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1152 tp->urg_data == TCP_URG_READ) 1153 return -EINVAL; /* Yes this is right ! */ 1154 1155 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1156 return -ENOTCONN; 1157 1158 if (tp->urg_data & TCP_URG_VALID) { 1159 int err = 0; 1160 char c = tp->urg_data; 1161 1162 if (!(flags & MSG_PEEK)) 1163 tp->urg_data = TCP_URG_READ; 1164 1165 /* Read urgent data. */ 1166 msg->msg_flags |= MSG_OOB; 1167 1168 if (len > 0) { 1169 if (!(flags & MSG_TRUNC)) 1170 err = memcpy_toiovec(msg->msg_iov, &c, 1); 1171 len = 1; 1172 } else 1173 msg->msg_flags |= MSG_TRUNC; 1174 1175 return err ? -EFAULT : len; 1176 } 1177 1178 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1179 return 0; 1180 1181 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1182 * the available implementations agree in this case: 1183 * this call should never block, independent of the 1184 * blocking state of the socket. 1185 * Mike <pall@rz.uni-karlsruhe.de> 1186 */ 1187 return -EAGAIN; 1188 } 1189 1190 /* Clean up the receive buffer for full frames taken by the user, 1191 * then send an ACK if necessary. COPIED is the number of bytes 1192 * tcp_recvmsg has given to the user so far, it speeds up the 1193 * calculation of whether or not we must ACK for the sake of 1194 * a window update. 1195 */ 1196 void tcp_cleanup_rbuf(struct sock *sk, int copied) 1197 { 1198 struct tcp_sock *tp = tcp_sk(sk); 1199 int time_to_ack = 0; 1200 1201 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1202 1203 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), 1204 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", 1205 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); 1206 1207 if (inet_csk_ack_scheduled(sk)) { 1208 const struct inet_connection_sock *icsk = inet_csk(sk); 1209 /* Delayed ACKs frequently hit locked sockets during bulk 1210 * receive. */ 1211 if (icsk->icsk_ack.blocked || 1212 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1213 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1214 /* 1215 * If this read emptied read buffer, we send ACK, if 1216 * connection is not bidirectional, user drained 1217 * receive buffer and there was a small segment 1218 * in queue. 1219 */ 1220 (copied > 0 && 1221 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1222 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1223 !icsk->icsk_ack.pingpong)) && 1224 !atomic_read(&sk->sk_rmem_alloc))) 1225 time_to_ack = 1; 1226 } 1227 1228 /* We send an ACK if we can now advertise a non-zero window 1229 * which has been raised "significantly". 1230 * 1231 * Even if window raised up to infinity, do not send window open ACK 1232 * in states, where we will not receive more. It is useless. 1233 */ 1234 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1235 __u32 rcv_window_now = tcp_receive_window(tp); 1236 1237 /* Optimize, __tcp_select_window() is not cheap. */ 1238 if (2*rcv_window_now <= tp->window_clamp) { 1239 __u32 new_window = __tcp_select_window(sk); 1240 1241 /* Send ACK now, if this read freed lots of space 1242 * in our buffer. Certainly, new_window is new window. 1243 * We can advertise it now, if it is not less than current one. 1244 * "Lots" means "at least twice" here. 1245 */ 1246 if (new_window && new_window >= 2 * rcv_window_now) 1247 time_to_ack = 1; 1248 } 1249 } 1250 if (time_to_ack) 1251 tcp_send_ack(sk); 1252 } 1253 1254 static void tcp_prequeue_process(struct sock *sk) 1255 { 1256 struct sk_buff *skb; 1257 struct tcp_sock *tp = tcp_sk(sk); 1258 1259 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); 1260 1261 /* RX process wants to run with disabled BHs, though it is not 1262 * necessary */ 1263 local_bh_disable(); 1264 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) 1265 sk_backlog_rcv(sk, skb); 1266 local_bh_enable(); 1267 1268 /* Clear memory counter. */ 1269 tp->ucopy.memory = 0; 1270 } 1271 1272 #ifdef CONFIG_NET_DMA 1273 static void tcp_service_net_dma(struct sock *sk, bool wait) 1274 { 1275 dma_cookie_t done, used; 1276 dma_cookie_t last_issued; 1277 struct tcp_sock *tp = tcp_sk(sk); 1278 1279 if (!tp->ucopy.dma_chan) 1280 return; 1281 1282 last_issued = tp->ucopy.dma_cookie; 1283 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1284 1285 do { 1286 if (dma_async_memcpy_complete(tp->ucopy.dma_chan, 1287 last_issued, &done, 1288 &used) == DMA_SUCCESS) { 1289 /* Safe to free early-copied skbs now */ 1290 __skb_queue_purge(&sk->sk_async_wait_queue); 1291 break; 1292 } else { 1293 struct sk_buff *skb; 1294 while ((skb = skb_peek(&sk->sk_async_wait_queue)) && 1295 (dma_async_is_complete(skb->dma_cookie, done, 1296 used) == DMA_SUCCESS)) { 1297 __skb_dequeue(&sk->sk_async_wait_queue); 1298 kfree_skb(skb); 1299 } 1300 } 1301 } while (wait); 1302 } 1303 #endif 1304 1305 static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1306 { 1307 struct sk_buff *skb; 1308 u32 offset; 1309 1310 skb_queue_walk(&sk->sk_receive_queue, skb) { 1311 offset = seq - TCP_SKB_CB(skb)->seq; 1312 if (tcp_hdr(skb)->syn) 1313 offset--; 1314 if (offset < skb->len || tcp_hdr(skb)->fin) { 1315 *off = offset; 1316 return skb; 1317 } 1318 } 1319 return NULL; 1320 } 1321 1322 /* 1323 * This routine provides an alternative to tcp_recvmsg() for routines 1324 * that would like to handle copying from skbuffs directly in 'sendfile' 1325 * fashion. 1326 * Note: 1327 * - It is assumed that the socket was locked by the caller. 1328 * - The routine does not block. 1329 * - At present, there is no support for reading OOB data 1330 * or for 'peeking' the socket using this routine 1331 * (although both would be easy to implement). 1332 */ 1333 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1334 sk_read_actor_t recv_actor) 1335 { 1336 struct sk_buff *skb; 1337 struct tcp_sock *tp = tcp_sk(sk); 1338 u32 seq = tp->copied_seq; 1339 u32 offset; 1340 int copied = 0; 1341 1342 if (sk->sk_state == TCP_LISTEN) 1343 return -ENOTCONN; 1344 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1345 if (offset < skb->len) { 1346 int used; 1347 size_t len; 1348 1349 len = skb->len - offset; 1350 /* Stop reading if we hit a patch of urgent data */ 1351 if (tp->urg_data) { 1352 u32 urg_offset = tp->urg_seq - seq; 1353 if (urg_offset < len) 1354 len = urg_offset; 1355 if (!len) 1356 break; 1357 } 1358 used = recv_actor(desc, skb, offset, len); 1359 if (used < 0) { 1360 if (!copied) 1361 copied = used; 1362 break; 1363 } else if (used <= len) { 1364 seq += used; 1365 copied += used; 1366 offset += used; 1367 } 1368 /* 1369 * If recv_actor drops the lock (e.g. TCP splice 1370 * receive) the skb pointer might be invalid when 1371 * getting here: tcp_collapse might have deleted it 1372 * while aggregating skbs from the socket queue. 1373 */ 1374 skb = tcp_recv_skb(sk, seq-1, &offset); 1375 if (!skb || (offset+1 != skb->len)) 1376 break; 1377 } 1378 if (tcp_hdr(skb)->fin) { 1379 sk_eat_skb(sk, skb, 0); 1380 ++seq; 1381 break; 1382 } 1383 sk_eat_skb(sk, skb, 0); 1384 if (!desc->count) 1385 break; 1386 tp->copied_seq = seq; 1387 } 1388 tp->copied_seq = seq; 1389 1390 tcp_rcv_space_adjust(sk); 1391 1392 /* Clean up data we have read: This will do ACK frames. */ 1393 if (copied > 0) 1394 tcp_cleanup_rbuf(sk, copied); 1395 return copied; 1396 } 1397 EXPORT_SYMBOL(tcp_read_sock); 1398 1399 /* 1400 * This routine copies from a sock struct into the user buffer. 1401 * 1402 * Technical note: in 2.3 we work on _locked_ socket, so that 1403 * tricks with *seq access order and skb->users are not required. 1404 * Probably, code can be easily improved even more. 1405 */ 1406 1407 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1408 size_t len, int nonblock, int flags, int *addr_len) 1409 { 1410 struct tcp_sock *tp = tcp_sk(sk); 1411 int copied = 0; 1412 u32 peek_seq; 1413 u32 *seq; 1414 unsigned long used; 1415 int err; 1416 int target; /* Read at least this many bytes */ 1417 long timeo; 1418 struct task_struct *user_recv = NULL; 1419 int copied_early = 0; 1420 struct sk_buff *skb; 1421 u32 urg_hole = 0; 1422 1423 lock_sock(sk); 1424 1425 err = -ENOTCONN; 1426 if (sk->sk_state == TCP_LISTEN) 1427 goto out; 1428 1429 timeo = sock_rcvtimeo(sk, nonblock); 1430 1431 /* Urgent data needs to be handled specially. */ 1432 if (flags & MSG_OOB) 1433 goto recv_urg; 1434 1435 seq = &tp->copied_seq; 1436 if (flags & MSG_PEEK) { 1437 peek_seq = tp->copied_seq; 1438 seq = &peek_seq; 1439 } 1440 1441 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1442 1443 #ifdef CONFIG_NET_DMA 1444 tp->ucopy.dma_chan = NULL; 1445 preempt_disable(); 1446 skb = skb_peek_tail(&sk->sk_receive_queue); 1447 { 1448 int available = 0; 1449 1450 if (skb) 1451 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); 1452 if ((available < target) && 1453 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && 1454 !sysctl_tcp_low_latency && 1455 net_dma_find_channel()) { 1456 preempt_enable_no_resched(); 1457 tp->ucopy.pinned_list = 1458 dma_pin_iovec_pages(msg->msg_iov, len); 1459 } else { 1460 preempt_enable_no_resched(); 1461 } 1462 } 1463 #endif 1464 1465 do { 1466 u32 offset; 1467 1468 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1469 if (tp->urg_data && tp->urg_seq == *seq) { 1470 if (copied) 1471 break; 1472 if (signal_pending(current)) { 1473 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1474 break; 1475 } 1476 } 1477 1478 /* Next get a buffer. */ 1479 1480 skb_queue_walk(&sk->sk_receive_queue, skb) { 1481 /* Now that we have two receive queues this 1482 * shouldn't happen. 1483 */ 1484 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 1485 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n", 1486 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 1487 flags)) 1488 break; 1489 1490 offset = *seq - TCP_SKB_CB(skb)->seq; 1491 if (tcp_hdr(skb)->syn) 1492 offset--; 1493 if (offset < skb->len) 1494 goto found_ok_skb; 1495 if (tcp_hdr(skb)->fin) 1496 goto found_fin_ok; 1497 WARN(!(flags & MSG_PEEK), 1498 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n", 1499 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); 1500 } 1501 1502 /* Well, if we have backlog, try to process it now yet. */ 1503 1504 if (copied >= target && !sk->sk_backlog.tail) 1505 break; 1506 1507 if (copied) { 1508 if (sk->sk_err || 1509 sk->sk_state == TCP_CLOSE || 1510 (sk->sk_shutdown & RCV_SHUTDOWN) || 1511 !timeo || 1512 signal_pending(current)) 1513 break; 1514 } else { 1515 if (sock_flag(sk, SOCK_DONE)) 1516 break; 1517 1518 if (sk->sk_err) { 1519 copied = sock_error(sk); 1520 break; 1521 } 1522 1523 if (sk->sk_shutdown & RCV_SHUTDOWN) 1524 break; 1525 1526 if (sk->sk_state == TCP_CLOSE) { 1527 if (!sock_flag(sk, SOCK_DONE)) { 1528 /* This occurs when user tries to read 1529 * from never connected socket. 1530 */ 1531 copied = -ENOTCONN; 1532 break; 1533 } 1534 break; 1535 } 1536 1537 if (!timeo) { 1538 copied = -EAGAIN; 1539 break; 1540 } 1541 1542 if (signal_pending(current)) { 1543 copied = sock_intr_errno(timeo); 1544 break; 1545 } 1546 } 1547 1548 tcp_cleanup_rbuf(sk, copied); 1549 1550 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { 1551 /* Install new reader */ 1552 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { 1553 user_recv = current; 1554 tp->ucopy.task = user_recv; 1555 tp->ucopy.iov = msg->msg_iov; 1556 } 1557 1558 tp->ucopy.len = len; 1559 1560 WARN_ON(tp->copied_seq != tp->rcv_nxt && 1561 !(flags & (MSG_PEEK | MSG_TRUNC))); 1562 1563 /* Ugly... If prequeue is not empty, we have to 1564 * process it before releasing socket, otherwise 1565 * order will be broken at second iteration. 1566 * More elegant solution is required!!! 1567 * 1568 * Look: we have the following (pseudo)queues: 1569 * 1570 * 1. packets in flight 1571 * 2. backlog 1572 * 3. prequeue 1573 * 4. receive_queue 1574 * 1575 * Each queue can be processed only if the next ones 1576 * are empty. At this point we have empty receive_queue. 1577 * But prequeue _can_ be not empty after 2nd iteration, 1578 * when we jumped to start of loop because backlog 1579 * processing added something to receive_queue. 1580 * We cannot release_sock(), because backlog contains 1581 * packets arrived _after_ prequeued ones. 1582 * 1583 * Shortly, algorithm is clear --- to process all 1584 * the queues in order. We could make it more directly, 1585 * requeueing packets from backlog to prequeue, if 1586 * is not empty. It is more elegant, but eats cycles, 1587 * unfortunately. 1588 */ 1589 if (!skb_queue_empty(&tp->ucopy.prequeue)) 1590 goto do_prequeue; 1591 1592 /* __ Set realtime policy in scheduler __ */ 1593 } 1594 1595 #ifdef CONFIG_NET_DMA 1596 if (tp->ucopy.dma_chan) 1597 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1598 #endif 1599 if (copied >= target) { 1600 /* Do not sleep, just process backlog. */ 1601 release_sock(sk); 1602 lock_sock(sk); 1603 } else 1604 sk_wait_data(sk, &timeo); 1605 1606 #ifdef CONFIG_NET_DMA 1607 tcp_service_net_dma(sk, false); /* Don't block */ 1608 tp->ucopy.wakeup = 0; 1609 #endif 1610 1611 if (user_recv) { 1612 int chunk; 1613 1614 /* __ Restore normal policy in scheduler __ */ 1615 1616 if ((chunk = len - tp->ucopy.len) != 0) { 1617 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); 1618 len -= chunk; 1619 copied += chunk; 1620 } 1621 1622 if (tp->rcv_nxt == tp->copied_seq && 1623 !skb_queue_empty(&tp->ucopy.prequeue)) { 1624 do_prequeue: 1625 tcp_prequeue_process(sk); 1626 1627 if ((chunk = len - tp->ucopy.len) != 0) { 1628 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1629 len -= chunk; 1630 copied += chunk; 1631 } 1632 } 1633 } 1634 if ((flags & MSG_PEEK) && 1635 (peek_seq - copied - urg_hole != tp->copied_seq)) { 1636 if (net_ratelimit()) 1637 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n", 1638 current->comm, task_pid_nr(current)); 1639 peek_seq = tp->copied_seq; 1640 } 1641 continue; 1642 1643 found_ok_skb: 1644 /* Ok so how much can we use? */ 1645 used = skb->len - offset; 1646 if (len < used) 1647 used = len; 1648 1649 /* Do we have urgent data here? */ 1650 if (tp->urg_data) { 1651 u32 urg_offset = tp->urg_seq - *seq; 1652 if (urg_offset < used) { 1653 if (!urg_offset) { 1654 if (!sock_flag(sk, SOCK_URGINLINE)) { 1655 ++*seq; 1656 urg_hole++; 1657 offset++; 1658 used--; 1659 if (!used) 1660 goto skip_copy; 1661 } 1662 } else 1663 used = urg_offset; 1664 } 1665 } 1666 1667 if (!(flags & MSG_TRUNC)) { 1668 #ifdef CONFIG_NET_DMA 1669 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1670 tp->ucopy.dma_chan = net_dma_find_channel(); 1671 1672 if (tp->ucopy.dma_chan) { 1673 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( 1674 tp->ucopy.dma_chan, skb, offset, 1675 msg->msg_iov, used, 1676 tp->ucopy.pinned_list); 1677 1678 if (tp->ucopy.dma_cookie < 0) { 1679 1680 pr_alert("%s: dma_cookie < 0\n", 1681 __func__); 1682 1683 /* Exception. Bailout! */ 1684 if (!copied) 1685 copied = -EFAULT; 1686 break; 1687 } 1688 1689 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1690 1691 if ((offset + used) == skb->len) 1692 copied_early = 1; 1693 1694 } else 1695 #endif 1696 { 1697 err = skb_copy_datagram_iovec(skb, offset, 1698 msg->msg_iov, used); 1699 if (err) { 1700 /* Exception. Bailout! */ 1701 if (!copied) 1702 copied = -EFAULT; 1703 break; 1704 } 1705 } 1706 } 1707 1708 *seq += used; 1709 copied += used; 1710 len -= used; 1711 1712 tcp_rcv_space_adjust(sk); 1713 1714 skip_copy: 1715 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1716 tp->urg_data = 0; 1717 tcp_fast_path_check(sk); 1718 } 1719 if (used + offset < skb->len) 1720 continue; 1721 1722 if (tcp_hdr(skb)->fin) 1723 goto found_fin_ok; 1724 if (!(flags & MSG_PEEK)) { 1725 sk_eat_skb(sk, skb, copied_early); 1726 copied_early = 0; 1727 } 1728 continue; 1729 1730 found_fin_ok: 1731 /* Process the FIN. */ 1732 ++*seq; 1733 if (!(flags & MSG_PEEK)) { 1734 sk_eat_skb(sk, skb, copied_early); 1735 copied_early = 0; 1736 } 1737 break; 1738 } while (len > 0); 1739 1740 if (user_recv) { 1741 if (!skb_queue_empty(&tp->ucopy.prequeue)) { 1742 int chunk; 1743 1744 tp->ucopy.len = copied > 0 ? len : 0; 1745 1746 tcp_prequeue_process(sk); 1747 1748 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { 1749 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1750 len -= chunk; 1751 copied += chunk; 1752 } 1753 } 1754 1755 tp->ucopy.task = NULL; 1756 tp->ucopy.len = 0; 1757 } 1758 1759 #ifdef CONFIG_NET_DMA 1760 tcp_service_net_dma(sk, true); /* Wait for queue to drain */ 1761 tp->ucopy.dma_chan = NULL; 1762 1763 if (tp->ucopy.pinned_list) { 1764 dma_unpin_iovec_pages(tp->ucopy.pinned_list); 1765 tp->ucopy.pinned_list = NULL; 1766 } 1767 #endif 1768 1769 /* According to UNIX98, msg_name/msg_namelen are ignored 1770 * on connected socket. I was just happy when found this 8) --ANK 1771 */ 1772 1773 /* Clean up data we have read: This will do ACK frames. */ 1774 tcp_cleanup_rbuf(sk, copied); 1775 1776 release_sock(sk); 1777 return copied; 1778 1779 out: 1780 release_sock(sk); 1781 return err; 1782 1783 recv_urg: 1784 err = tcp_recv_urg(sk, msg, len, flags); 1785 goto out; 1786 } 1787 EXPORT_SYMBOL(tcp_recvmsg); 1788 1789 void tcp_set_state(struct sock *sk, int state) 1790 { 1791 int oldstate = sk->sk_state; 1792 1793 switch (state) { 1794 case TCP_ESTABLISHED: 1795 if (oldstate != TCP_ESTABLISHED) 1796 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1797 break; 1798 1799 case TCP_CLOSE: 1800 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 1801 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 1802 1803 sk->sk_prot->unhash(sk); 1804 if (inet_csk(sk)->icsk_bind_hash && 1805 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1806 inet_put_port(sk); 1807 /* fall through */ 1808 default: 1809 if (oldstate == TCP_ESTABLISHED) 1810 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1811 } 1812 1813 /* Change state AFTER socket is unhashed to avoid closed 1814 * socket sitting in hash tables. 1815 */ 1816 sk->sk_state = state; 1817 1818 #ifdef STATE_TRACE 1819 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); 1820 #endif 1821 } 1822 EXPORT_SYMBOL_GPL(tcp_set_state); 1823 1824 /* 1825 * State processing on a close. This implements the state shift for 1826 * sending our FIN frame. Note that we only send a FIN for some 1827 * states. A shutdown() may have already sent the FIN, or we may be 1828 * closed. 1829 */ 1830 1831 static const unsigned char new_state[16] = { 1832 /* current state: new state: action: */ 1833 /* (Invalid) */ TCP_CLOSE, 1834 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1835 /* TCP_SYN_SENT */ TCP_CLOSE, 1836 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1837 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, 1838 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, 1839 /* TCP_TIME_WAIT */ TCP_CLOSE, 1840 /* TCP_CLOSE */ TCP_CLOSE, 1841 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, 1842 /* TCP_LAST_ACK */ TCP_LAST_ACK, 1843 /* TCP_LISTEN */ TCP_CLOSE, 1844 /* TCP_CLOSING */ TCP_CLOSING, 1845 }; 1846 1847 static int tcp_close_state(struct sock *sk) 1848 { 1849 int next = (int)new_state[sk->sk_state]; 1850 int ns = next & TCP_STATE_MASK; 1851 1852 tcp_set_state(sk, ns); 1853 1854 return next & TCP_ACTION_FIN; 1855 } 1856 1857 /* 1858 * Shutdown the sending side of a connection. Much like close except 1859 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 1860 */ 1861 1862 void tcp_shutdown(struct sock *sk, int how) 1863 { 1864 /* We need to grab some memory, and put together a FIN, 1865 * and then put it into the queue to be sent. 1866 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 1867 */ 1868 if (!(how & SEND_SHUTDOWN)) 1869 return; 1870 1871 /* If we've already sent a FIN, or it's a closed state, skip this. */ 1872 if ((1 << sk->sk_state) & 1873 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 1874 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 1875 /* Clear out any half completed packets. FIN if needed. */ 1876 if (tcp_close_state(sk)) 1877 tcp_send_fin(sk); 1878 } 1879 } 1880 EXPORT_SYMBOL(tcp_shutdown); 1881 1882 bool tcp_check_oom(struct sock *sk, int shift) 1883 { 1884 bool too_many_orphans, out_of_socket_memory; 1885 1886 too_many_orphans = tcp_too_many_orphans(sk, shift); 1887 out_of_socket_memory = tcp_out_of_memory(sk); 1888 1889 if (too_many_orphans && net_ratelimit()) 1890 pr_info("too many orphaned sockets\n"); 1891 if (out_of_socket_memory && net_ratelimit()) 1892 pr_info("out of memory -- consider tuning tcp_mem\n"); 1893 return too_many_orphans || out_of_socket_memory; 1894 } 1895 1896 void tcp_close(struct sock *sk, long timeout) 1897 { 1898 struct sk_buff *skb; 1899 int data_was_unread = 0; 1900 int state; 1901 1902 lock_sock(sk); 1903 sk->sk_shutdown = SHUTDOWN_MASK; 1904 1905 if (sk->sk_state == TCP_LISTEN) { 1906 tcp_set_state(sk, TCP_CLOSE); 1907 1908 /* Special case. */ 1909 inet_csk_listen_stop(sk); 1910 1911 goto adjudge_to_death; 1912 } 1913 1914 /* We need to flush the recv. buffs. We do this only on the 1915 * descriptor close, not protocol-sourced closes, because the 1916 * reader process may not have drained the data yet! 1917 */ 1918 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1919 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - 1920 tcp_hdr(skb)->fin; 1921 data_was_unread += len; 1922 __kfree_skb(skb); 1923 } 1924 1925 sk_mem_reclaim(sk); 1926 1927 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ 1928 if (sk->sk_state == TCP_CLOSE) 1929 goto adjudge_to_death; 1930 1931 /* As outlined in RFC 2525, section 2.17, we send a RST here because 1932 * data was lost. To witness the awful effects of the old behavior of 1933 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 1934 * GET in an FTP client, suspend the process, wait for the client to 1935 * advertise a zero window, then kill -9 the FTP client, wheee... 1936 * Note: timeout is always zero in such a case. 1937 */ 1938 if (data_was_unread) { 1939 /* Unread data was tossed, zap the connection. */ 1940 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 1941 tcp_set_state(sk, TCP_CLOSE); 1942 tcp_send_active_reset(sk, sk->sk_allocation); 1943 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1944 /* Check zero linger _after_ checking for unread data. */ 1945 sk->sk_prot->disconnect(sk, 0); 1946 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 1947 } else if (tcp_close_state(sk)) { 1948 /* We FIN if the application ate all the data before 1949 * zapping the connection. 1950 */ 1951 1952 /* RED-PEN. Formally speaking, we have broken TCP state 1953 * machine. State transitions: 1954 * 1955 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 1956 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 1957 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 1958 * 1959 * are legal only when FIN has been sent (i.e. in window), 1960 * rather than queued out of window. Purists blame. 1961 * 1962 * F.e. "RFC state" is ESTABLISHED, 1963 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 1964 * 1965 * The visible declinations are that sometimes 1966 * we enter time-wait state, when it is not required really 1967 * (harmless), do not send active resets, when they are 1968 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 1969 * they look as CLOSING or LAST_ACK for Linux) 1970 * Probably, I missed some more holelets. 1971 * --ANK 1972 */ 1973 tcp_send_fin(sk); 1974 } 1975 1976 sk_stream_wait_close(sk, timeout); 1977 1978 adjudge_to_death: 1979 state = sk->sk_state; 1980 sock_hold(sk); 1981 sock_orphan(sk); 1982 1983 /* It is the last release_sock in its life. It will remove backlog. */ 1984 release_sock(sk); 1985 1986 1987 /* Now socket is owned by kernel and we acquire BH lock 1988 to finish close. No need to check for user refs. 1989 */ 1990 local_bh_disable(); 1991 bh_lock_sock(sk); 1992 WARN_ON(sock_owned_by_user(sk)); 1993 1994 percpu_counter_inc(sk->sk_prot->orphan_count); 1995 1996 /* Have we already been destroyed by a softirq or backlog? */ 1997 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 1998 goto out; 1999 2000 /* This is a (useful) BSD violating of the RFC. There is a 2001 * problem with TCP as specified in that the other end could 2002 * keep a socket open forever with no application left this end. 2003 * We use a 3 minute timeout (about the same as BSD) then kill 2004 * our end. If they send after that then tough - BUT: long enough 2005 * that we won't make the old 4*rto = almost no time - whoops 2006 * reset mistake. 2007 * 2008 * Nope, it was not mistake. It is really desired behaviour 2009 * f.e. on http servers, when such sockets are useless, but 2010 * consume significant resources. Let's do it with special 2011 * linger2 option. --ANK 2012 */ 2013 2014 if (sk->sk_state == TCP_FIN_WAIT2) { 2015 struct tcp_sock *tp = tcp_sk(sk); 2016 if (tp->linger2 < 0) { 2017 tcp_set_state(sk, TCP_CLOSE); 2018 tcp_send_active_reset(sk, GFP_ATOMIC); 2019 NET_INC_STATS_BH(sock_net(sk), 2020 LINUX_MIB_TCPABORTONLINGER); 2021 } else { 2022 const int tmo = tcp_fin_time(sk); 2023 2024 if (tmo > TCP_TIMEWAIT_LEN) { 2025 inet_csk_reset_keepalive_timer(sk, 2026 tmo - TCP_TIMEWAIT_LEN); 2027 } else { 2028 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 2029 goto out; 2030 } 2031 } 2032 } 2033 if (sk->sk_state != TCP_CLOSE) { 2034 sk_mem_reclaim(sk); 2035 if (tcp_check_oom(sk, 0)) { 2036 tcp_set_state(sk, TCP_CLOSE); 2037 tcp_send_active_reset(sk, GFP_ATOMIC); 2038 NET_INC_STATS_BH(sock_net(sk), 2039 LINUX_MIB_TCPABORTONMEMORY); 2040 } 2041 } 2042 2043 if (sk->sk_state == TCP_CLOSE) 2044 inet_csk_destroy_sock(sk); 2045 /* Otherwise, socket is reprieved until protocol close. */ 2046 2047 out: 2048 bh_unlock_sock(sk); 2049 local_bh_enable(); 2050 sock_put(sk); 2051 } 2052 EXPORT_SYMBOL(tcp_close); 2053 2054 /* These states need RST on ABORT according to RFC793 */ 2055 2056 static inline int tcp_need_reset(int state) 2057 { 2058 return (1 << state) & 2059 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2060 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2061 } 2062 2063 int tcp_disconnect(struct sock *sk, int flags) 2064 { 2065 struct inet_sock *inet = inet_sk(sk); 2066 struct inet_connection_sock *icsk = inet_csk(sk); 2067 struct tcp_sock *tp = tcp_sk(sk); 2068 int err = 0; 2069 int old_state = sk->sk_state; 2070 2071 if (old_state != TCP_CLOSE) 2072 tcp_set_state(sk, TCP_CLOSE); 2073 2074 /* ABORT function of RFC793 */ 2075 if (old_state == TCP_LISTEN) { 2076 inet_csk_listen_stop(sk); 2077 } else if (tcp_need_reset(old_state) || 2078 (tp->snd_nxt != tp->write_seq && 2079 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2080 /* The last check adjusts for discrepancy of Linux wrt. RFC 2081 * states 2082 */ 2083 tcp_send_active_reset(sk, gfp_any()); 2084 sk->sk_err = ECONNRESET; 2085 } else if (old_state == TCP_SYN_SENT) 2086 sk->sk_err = ECONNRESET; 2087 2088 tcp_clear_xmit_timers(sk); 2089 __skb_queue_purge(&sk->sk_receive_queue); 2090 tcp_write_queue_purge(sk); 2091 __skb_queue_purge(&tp->out_of_order_queue); 2092 #ifdef CONFIG_NET_DMA 2093 __skb_queue_purge(&sk->sk_async_wait_queue); 2094 #endif 2095 2096 inet->inet_dport = 0; 2097 2098 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2099 inet_reset_saddr(sk); 2100 2101 sk->sk_shutdown = 0; 2102 sock_reset_flag(sk, SOCK_DONE); 2103 tp->srtt = 0; 2104 if ((tp->write_seq += tp->max_window + 2) == 0) 2105 tp->write_seq = 1; 2106 icsk->icsk_backoff = 0; 2107 tp->snd_cwnd = 2; 2108 icsk->icsk_probes_out = 0; 2109 tp->packets_out = 0; 2110 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2111 tp->snd_cwnd_cnt = 0; 2112 tp->bytes_acked = 0; 2113 tp->window_clamp = 0; 2114 tcp_set_ca_state(sk, TCP_CA_Open); 2115 tcp_clear_retrans(tp); 2116 inet_csk_delack_init(sk); 2117 tcp_init_send_head(sk); 2118 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2119 __sk_dst_reset(sk); 2120 2121 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2122 2123 sk->sk_error_report(sk); 2124 return err; 2125 } 2126 EXPORT_SYMBOL(tcp_disconnect); 2127 2128 /* 2129 * Socket option code for TCP. 2130 */ 2131 static int do_tcp_setsockopt(struct sock *sk, int level, 2132 int optname, char __user *optval, unsigned int optlen) 2133 { 2134 struct tcp_sock *tp = tcp_sk(sk); 2135 struct inet_connection_sock *icsk = inet_csk(sk); 2136 int val; 2137 int err = 0; 2138 2139 /* These are data/string values, all the others are ints */ 2140 switch (optname) { 2141 case TCP_CONGESTION: { 2142 char name[TCP_CA_NAME_MAX]; 2143 2144 if (optlen < 1) 2145 return -EINVAL; 2146 2147 val = strncpy_from_user(name, optval, 2148 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2149 if (val < 0) 2150 return -EFAULT; 2151 name[val] = 0; 2152 2153 lock_sock(sk); 2154 err = tcp_set_congestion_control(sk, name); 2155 release_sock(sk); 2156 return err; 2157 } 2158 case TCP_COOKIE_TRANSACTIONS: { 2159 struct tcp_cookie_transactions ctd; 2160 struct tcp_cookie_values *cvp = NULL; 2161 2162 if (sizeof(ctd) > optlen) 2163 return -EINVAL; 2164 if (copy_from_user(&ctd, optval, sizeof(ctd))) 2165 return -EFAULT; 2166 2167 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) || 2168 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED) 2169 return -EINVAL; 2170 2171 if (ctd.tcpct_cookie_desired == 0) { 2172 /* default to global value */ 2173 } else if ((0x1 & ctd.tcpct_cookie_desired) || 2174 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX || 2175 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) { 2176 return -EINVAL; 2177 } 2178 2179 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) { 2180 /* Supercedes all other values */ 2181 lock_sock(sk); 2182 if (tp->cookie_values != NULL) { 2183 kref_put(&tp->cookie_values->kref, 2184 tcp_cookie_values_release); 2185 tp->cookie_values = NULL; 2186 } 2187 tp->rx_opt.cookie_in_always = 0; /* false */ 2188 tp->rx_opt.cookie_out_never = 1; /* true */ 2189 release_sock(sk); 2190 return err; 2191 } 2192 2193 /* Allocate ancillary memory before locking. 2194 */ 2195 if (ctd.tcpct_used > 0 || 2196 (tp->cookie_values == NULL && 2197 (sysctl_tcp_cookie_size > 0 || 2198 ctd.tcpct_cookie_desired > 0 || 2199 ctd.tcpct_s_data_desired > 0))) { 2200 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used, 2201 GFP_KERNEL); 2202 if (cvp == NULL) 2203 return -ENOMEM; 2204 2205 kref_init(&cvp->kref); 2206 } 2207 lock_sock(sk); 2208 tp->rx_opt.cookie_in_always = 2209 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags); 2210 tp->rx_opt.cookie_out_never = 0; /* false */ 2211 2212 if (tp->cookie_values != NULL) { 2213 if (cvp != NULL) { 2214 /* Changed values are recorded by a changed 2215 * pointer, ensuring the cookie will differ, 2216 * without separately hashing each value later. 2217 */ 2218 kref_put(&tp->cookie_values->kref, 2219 tcp_cookie_values_release); 2220 } else { 2221 cvp = tp->cookie_values; 2222 } 2223 } 2224 2225 if (cvp != NULL) { 2226 cvp->cookie_desired = ctd.tcpct_cookie_desired; 2227 2228 if (ctd.tcpct_used > 0) { 2229 memcpy(cvp->s_data_payload, ctd.tcpct_value, 2230 ctd.tcpct_used); 2231 cvp->s_data_desired = ctd.tcpct_used; 2232 cvp->s_data_constant = 1; /* true */ 2233 } else { 2234 /* No constant payload data. */ 2235 cvp->s_data_desired = ctd.tcpct_s_data_desired; 2236 cvp->s_data_constant = 0; /* false */ 2237 } 2238 2239 tp->cookie_values = cvp; 2240 } 2241 release_sock(sk); 2242 return err; 2243 } 2244 default: 2245 /* fallthru */ 2246 break; 2247 } 2248 2249 if (optlen < sizeof(int)) 2250 return -EINVAL; 2251 2252 if (get_user(val, (int __user *)optval)) 2253 return -EFAULT; 2254 2255 lock_sock(sk); 2256 2257 switch (optname) { 2258 case TCP_MAXSEG: 2259 /* Values greater than interface MTU won't take effect. However 2260 * at the point when this call is done we typically don't yet 2261 * know which interface is going to be used */ 2262 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) { 2263 err = -EINVAL; 2264 break; 2265 } 2266 tp->rx_opt.user_mss = val; 2267 break; 2268 2269 case TCP_NODELAY: 2270 if (val) { 2271 /* TCP_NODELAY is weaker than TCP_CORK, so that 2272 * this option on corked socket is remembered, but 2273 * it is not activated until cork is cleared. 2274 * 2275 * However, when TCP_NODELAY is set we make 2276 * an explicit push, which overrides even TCP_CORK 2277 * for currently queued segments. 2278 */ 2279 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2280 tcp_push_pending_frames(sk); 2281 } else { 2282 tp->nonagle &= ~TCP_NAGLE_OFF; 2283 } 2284 break; 2285 2286 case TCP_THIN_LINEAR_TIMEOUTS: 2287 if (val < 0 || val > 1) 2288 err = -EINVAL; 2289 else 2290 tp->thin_lto = val; 2291 break; 2292 2293 case TCP_THIN_DUPACK: 2294 if (val < 0 || val > 1) 2295 err = -EINVAL; 2296 else 2297 tp->thin_dupack = val; 2298 break; 2299 2300 case TCP_CORK: 2301 /* When set indicates to always queue non-full frames. 2302 * Later the user clears this option and we transmit 2303 * any pending partial frames in the queue. This is 2304 * meant to be used alongside sendfile() to get properly 2305 * filled frames when the user (for example) must write 2306 * out headers with a write() call first and then use 2307 * sendfile to send out the data parts. 2308 * 2309 * TCP_CORK can be set together with TCP_NODELAY and it is 2310 * stronger than TCP_NODELAY. 2311 */ 2312 if (val) { 2313 tp->nonagle |= TCP_NAGLE_CORK; 2314 } else { 2315 tp->nonagle &= ~TCP_NAGLE_CORK; 2316 if (tp->nonagle&TCP_NAGLE_OFF) 2317 tp->nonagle |= TCP_NAGLE_PUSH; 2318 tcp_push_pending_frames(sk); 2319 } 2320 break; 2321 2322 case TCP_KEEPIDLE: 2323 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2324 err = -EINVAL; 2325 else { 2326 tp->keepalive_time = val * HZ; 2327 if (sock_flag(sk, SOCK_KEEPOPEN) && 2328 !((1 << sk->sk_state) & 2329 (TCPF_CLOSE | TCPF_LISTEN))) { 2330 u32 elapsed = keepalive_time_elapsed(tp); 2331 if (tp->keepalive_time > elapsed) 2332 elapsed = tp->keepalive_time - elapsed; 2333 else 2334 elapsed = 0; 2335 inet_csk_reset_keepalive_timer(sk, elapsed); 2336 } 2337 } 2338 break; 2339 case TCP_KEEPINTVL: 2340 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2341 err = -EINVAL; 2342 else 2343 tp->keepalive_intvl = val * HZ; 2344 break; 2345 case TCP_KEEPCNT: 2346 if (val < 1 || val > MAX_TCP_KEEPCNT) 2347 err = -EINVAL; 2348 else 2349 tp->keepalive_probes = val; 2350 break; 2351 case TCP_SYNCNT: 2352 if (val < 1 || val > MAX_TCP_SYNCNT) 2353 err = -EINVAL; 2354 else 2355 icsk->icsk_syn_retries = val; 2356 break; 2357 2358 case TCP_LINGER2: 2359 if (val < 0) 2360 tp->linger2 = -1; 2361 else if (val > sysctl_tcp_fin_timeout / HZ) 2362 tp->linger2 = 0; 2363 else 2364 tp->linger2 = val * HZ; 2365 break; 2366 2367 case TCP_DEFER_ACCEPT: 2368 /* Translate value in seconds to number of retransmits */ 2369 icsk->icsk_accept_queue.rskq_defer_accept = 2370 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2371 TCP_RTO_MAX / HZ); 2372 break; 2373 2374 case TCP_WINDOW_CLAMP: 2375 if (!val) { 2376 if (sk->sk_state != TCP_CLOSE) { 2377 err = -EINVAL; 2378 break; 2379 } 2380 tp->window_clamp = 0; 2381 } else 2382 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2383 SOCK_MIN_RCVBUF / 2 : val; 2384 break; 2385 2386 case TCP_QUICKACK: 2387 if (!val) { 2388 icsk->icsk_ack.pingpong = 1; 2389 } else { 2390 icsk->icsk_ack.pingpong = 0; 2391 if ((1 << sk->sk_state) & 2392 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2393 inet_csk_ack_scheduled(sk)) { 2394 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2395 tcp_cleanup_rbuf(sk, 1); 2396 if (!(val & 1)) 2397 icsk->icsk_ack.pingpong = 1; 2398 } 2399 } 2400 break; 2401 2402 #ifdef CONFIG_TCP_MD5SIG 2403 case TCP_MD5SIG: 2404 /* Read the IP->Key mappings from userspace */ 2405 err = tp->af_specific->md5_parse(sk, optval, optlen); 2406 break; 2407 #endif 2408 case TCP_USER_TIMEOUT: 2409 /* Cap the max timeout in ms TCP will retry/retrans 2410 * before giving up and aborting (ETIMEDOUT) a connection. 2411 */ 2412 icsk->icsk_user_timeout = msecs_to_jiffies(val); 2413 break; 2414 default: 2415 err = -ENOPROTOOPT; 2416 break; 2417 } 2418 2419 release_sock(sk); 2420 return err; 2421 } 2422 2423 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2424 unsigned int optlen) 2425 { 2426 const struct inet_connection_sock *icsk = inet_csk(sk); 2427 2428 if (level != SOL_TCP) 2429 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2430 optval, optlen); 2431 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2432 } 2433 EXPORT_SYMBOL(tcp_setsockopt); 2434 2435 #ifdef CONFIG_COMPAT 2436 int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2437 char __user *optval, unsigned int optlen) 2438 { 2439 if (level != SOL_TCP) 2440 return inet_csk_compat_setsockopt(sk, level, optname, 2441 optval, optlen); 2442 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2443 } 2444 EXPORT_SYMBOL(compat_tcp_setsockopt); 2445 #endif 2446 2447 /* Return information about state of tcp endpoint in API format. */ 2448 void tcp_get_info(const struct sock *sk, struct tcp_info *info) 2449 { 2450 const struct tcp_sock *tp = tcp_sk(sk); 2451 const struct inet_connection_sock *icsk = inet_csk(sk); 2452 u32 now = tcp_time_stamp; 2453 2454 memset(info, 0, sizeof(*info)); 2455 2456 info->tcpi_state = sk->sk_state; 2457 info->tcpi_ca_state = icsk->icsk_ca_state; 2458 info->tcpi_retransmits = icsk->icsk_retransmits; 2459 info->tcpi_probes = icsk->icsk_probes_out; 2460 info->tcpi_backoff = icsk->icsk_backoff; 2461 2462 if (tp->rx_opt.tstamp_ok) 2463 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2464 if (tcp_is_sack(tp)) 2465 info->tcpi_options |= TCPI_OPT_SACK; 2466 if (tp->rx_opt.wscale_ok) { 2467 info->tcpi_options |= TCPI_OPT_WSCALE; 2468 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2469 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2470 } 2471 2472 if (tp->ecn_flags & TCP_ECN_OK) 2473 info->tcpi_options |= TCPI_OPT_ECN; 2474 if (tp->ecn_flags & TCP_ECN_SEEN) 2475 info->tcpi_options |= TCPI_OPT_ECN_SEEN; 2476 2477 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2478 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2479 info->tcpi_snd_mss = tp->mss_cache; 2480 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2481 2482 if (sk->sk_state == TCP_LISTEN) { 2483 info->tcpi_unacked = sk->sk_ack_backlog; 2484 info->tcpi_sacked = sk->sk_max_ack_backlog; 2485 } else { 2486 info->tcpi_unacked = tp->packets_out; 2487 info->tcpi_sacked = tp->sacked_out; 2488 } 2489 info->tcpi_lost = tp->lost_out; 2490 info->tcpi_retrans = tp->retrans_out; 2491 info->tcpi_fackets = tp->fackets_out; 2492 2493 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2494 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2495 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2496 2497 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2498 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2499 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3; 2500 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2; 2501 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2502 info->tcpi_snd_cwnd = tp->snd_cwnd; 2503 info->tcpi_advmss = tp->advmss; 2504 info->tcpi_reordering = tp->reordering; 2505 2506 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; 2507 info->tcpi_rcv_space = tp->rcvq_space.space; 2508 2509 info->tcpi_total_retrans = tp->total_retrans; 2510 } 2511 EXPORT_SYMBOL_GPL(tcp_get_info); 2512 2513 static int do_tcp_getsockopt(struct sock *sk, int level, 2514 int optname, char __user *optval, int __user *optlen) 2515 { 2516 struct inet_connection_sock *icsk = inet_csk(sk); 2517 struct tcp_sock *tp = tcp_sk(sk); 2518 int val, len; 2519 2520 if (get_user(len, optlen)) 2521 return -EFAULT; 2522 2523 len = min_t(unsigned int, len, sizeof(int)); 2524 2525 if (len < 0) 2526 return -EINVAL; 2527 2528 switch (optname) { 2529 case TCP_MAXSEG: 2530 val = tp->mss_cache; 2531 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2532 val = tp->rx_opt.user_mss; 2533 break; 2534 case TCP_NODELAY: 2535 val = !!(tp->nonagle&TCP_NAGLE_OFF); 2536 break; 2537 case TCP_CORK: 2538 val = !!(tp->nonagle&TCP_NAGLE_CORK); 2539 break; 2540 case TCP_KEEPIDLE: 2541 val = keepalive_time_when(tp) / HZ; 2542 break; 2543 case TCP_KEEPINTVL: 2544 val = keepalive_intvl_when(tp) / HZ; 2545 break; 2546 case TCP_KEEPCNT: 2547 val = keepalive_probes(tp); 2548 break; 2549 case TCP_SYNCNT: 2550 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 2551 break; 2552 case TCP_LINGER2: 2553 val = tp->linger2; 2554 if (val >= 0) 2555 val = (val ? : sysctl_tcp_fin_timeout) / HZ; 2556 break; 2557 case TCP_DEFER_ACCEPT: 2558 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 2559 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 2560 break; 2561 case TCP_WINDOW_CLAMP: 2562 val = tp->window_clamp; 2563 break; 2564 case TCP_INFO: { 2565 struct tcp_info info; 2566 2567 if (get_user(len, optlen)) 2568 return -EFAULT; 2569 2570 tcp_get_info(sk, &info); 2571 2572 len = min_t(unsigned int, len, sizeof(info)); 2573 if (put_user(len, optlen)) 2574 return -EFAULT; 2575 if (copy_to_user(optval, &info, len)) 2576 return -EFAULT; 2577 return 0; 2578 } 2579 case TCP_QUICKACK: 2580 val = !icsk->icsk_ack.pingpong; 2581 break; 2582 2583 case TCP_CONGESTION: 2584 if (get_user(len, optlen)) 2585 return -EFAULT; 2586 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 2587 if (put_user(len, optlen)) 2588 return -EFAULT; 2589 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 2590 return -EFAULT; 2591 return 0; 2592 2593 case TCP_COOKIE_TRANSACTIONS: { 2594 struct tcp_cookie_transactions ctd; 2595 struct tcp_cookie_values *cvp = tp->cookie_values; 2596 2597 if (get_user(len, optlen)) 2598 return -EFAULT; 2599 if (len < sizeof(ctd)) 2600 return -EINVAL; 2601 2602 memset(&ctd, 0, sizeof(ctd)); 2603 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ? 2604 TCP_COOKIE_IN_ALWAYS : 0) 2605 | (tp->rx_opt.cookie_out_never ? 2606 TCP_COOKIE_OUT_NEVER : 0); 2607 2608 if (cvp != NULL) { 2609 ctd.tcpct_flags |= (cvp->s_data_in ? 2610 TCP_S_DATA_IN : 0) 2611 | (cvp->s_data_out ? 2612 TCP_S_DATA_OUT : 0); 2613 2614 ctd.tcpct_cookie_desired = cvp->cookie_desired; 2615 ctd.tcpct_s_data_desired = cvp->s_data_desired; 2616 2617 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0], 2618 cvp->cookie_pair_size); 2619 ctd.tcpct_used = cvp->cookie_pair_size; 2620 } 2621 2622 if (put_user(sizeof(ctd), optlen)) 2623 return -EFAULT; 2624 if (copy_to_user(optval, &ctd, sizeof(ctd))) 2625 return -EFAULT; 2626 return 0; 2627 } 2628 case TCP_THIN_LINEAR_TIMEOUTS: 2629 val = tp->thin_lto; 2630 break; 2631 case TCP_THIN_DUPACK: 2632 val = tp->thin_dupack; 2633 break; 2634 2635 case TCP_USER_TIMEOUT: 2636 val = jiffies_to_msecs(icsk->icsk_user_timeout); 2637 break; 2638 default: 2639 return -ENOPROTOOPT; 2640 } 2641 2642 if (put_user(len, optlen)) 2643 return -EFAULT; 2644 if (copy_to_user(optval, &val, len)) 2645 return -EFAULT; 2646 return 0; 2647 } 2648 2649 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 2650 int __user *optlen) 2651 { 2652 struct inet_connection_sock *icsk = inet_csk(sk); 2653 2654 if (level != SOL_TCP) 2655 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 2656 optval, optlen); 2657 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2658 } 2659 EXPORT_SYMBOL(tcp_getsockopt); 2660 2661 #ifdef CONFIG_COMPAT 2662 int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 2663 char __user *optval, int __user *optlen) 2664 { 2665 if (level != SOL_TCP) 2666 return inet_csk_compat_getsockopt(sk, level, optname, 2667 optval, optlen); 2668 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2669 } 2670 EXPORT_SYMBOL(compat_tcp_getsockopt); 2671 #endif 2672 2673 struct sk_buff *tcp_tso_segment(struct sk_buff *skb, 2674 netdev_features_t features) 2675 { 2676 struct sk_buff *segs = ERR_PTR(-EINVAL); 2677 struct tcphdr *th; 2678 unsigned thlen; 2679 unsigned int seq; 2680 __be32 delta; 2681 unsigned int oldlen; 2682 unsigned int mss; 2683 2684 if (!pskb_may_pull(skb, sizeof(*th))) 2685 goto out; 2686 2687 th = tcp_hdr(skb); 2688 thlen = th->doff * 4; 2689 if (thlen < sizeof(*th)) 2690 goto out; 2691 2692 if (!pskb_may_pull(skb, thlen)) 2693 goto out; 2694 2695 oldlen = (u16)~skb->len; 2696 __skb_pull(skb, thlen); 2697 2698 mss = skb_shinfo(skb)->gso_size; 2699 if (unlikely(skb->len <= mss)) 2700 goto out; 2701 2702 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2703 /* Packet is from an untrusted source, reset gso_segs. */ 2704 int type = skb_shinfo(skb)->gso_type; 2705 2706 if (unlikely(type & 2707 ~(SKB_GSO_TCPV4 | 2708 SKB_GSO_DODGY | 2709 SKB_GSO_TCP_ECN | 2710 SKB_GSO_TCPV6 | 2711 0) || 2712 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))) 2713 goto out; 2714 2715 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2716 2717 segs = NULL; 2718 goto out; 2719 } 2720 2721 segs = skb_segment(skb, features); 2722 if (IS_ERR(segs)) 2723 goto out; 2724 2725 delta = htonl(oldlen + (thlen + mss)); 2726 2727 skb = segs; 2728 th = tcp_hdr(skb); 2729 seq = ntohl(th->seq); 2730 2731 do { 2732 th->fin = th->psh = 0; 2733 2734 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2735 (__force u32)delta)); 2736 if (skb->ip_summed != CHECKSUM_PARTIAL) 2737 th->check = 2738 csum_fold(csum_partial(skb_transport_header(skb), 2739 thlen, skb->csum)); 2740 2741 seq += mss; 2742 skb = skb->next; 2743 th = tcp_hdr(skb); 2744 2745 th->seq = htonl(seq); 2746 th->cwr = 0; 2747 } while (skb->next); 2748 2749 delta = htonl(oldlen + (skb->tail - skb->transport_header) + 2750 skb->data_len); 2751 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2752 (__force u32)delta)); 2753 if (skb->ip_summed != CHECKSUM_PARTIAL) 2754 th->check = csum_fold(csum_partial(skb_transport_header(skb), 2755 thlen, skb->csum)); 2756 2757 out: 2758 return segs; 2759 } 2760 EXPORT_SYMBOL(tcp_tso_segment); 2761 2762 struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) 2763 { 2764 struct sk_buff **pp = NULL; 2765 struct sk_buff *p; 2766 struct tcphdr *th; 2767 struct tcphdr *th2; 2768 unsigned int len; 2769 unsigned int thlen; 2770 __be32 flags; 2771 unsigned int mss = 1; 2772 unsigned int hlen; 2773 unsigned int off; 2774 int flush = 1; 2775 int i; 2776 2777 off = skb_gro_offset(skb); 2778 hlen = off + sizeof(*th); 2779 th = skb_gro_header_fast(skb, off); 2780 if (skb_gro_header_hard(skb, hlen)) { 2781 th = skb_gro_header_slow(skb, hlen, off); 2782 if (unlikely(!th)) 2783 goto out; 2784 } 2785 2786 thlen = th->doff * 4; 2787 if (thlen < sizeof(*th)) 2788 goto out; 2789 2790 hlen = off + thlen; 2791 if (skb_gro_header_hard(skb, hlen)) { 2792 th = skb_gro_header_slow(skb, hlen, off); 2793 if (unlikely(!th)) 2794 goto out; 2795 } 2796 2797 skb_gro_pull(skb, thlen); 2798 2799 len = skb_gro_len(skb); 2800 flags = tcp_flag_word(th); 2801 2802 for (; (p = *head); head = &p->next) { 2803 if (!NAPI_GRO_CB(p)->same_flow) 2804 continue; 2805 2806 th2 = tcp_hdr(p); 2807 2808 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) { 2809 NAPI_GRO_CB(p)->same_flow = 0; 2810 continue; 2811 } 2812 2813 goto found; 2814 } 2815 2816 goto out_check_final; 2817 2818 found: 2819 flush = NAPI_GRO_CB(p)->flush; 2820 flush |= (__force int)(flags & TCP_FLAG_CWR); 2821 flush |= (__force int)((flags ^ tcp_flag_word(th2)) & 2822 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH)); 2823 flush |= (__force int)(th->ack_seq ^ th2->ack_seq); 2824 for (i = sizeof(*th); i < thlen; i += 4) 2825 flush |= *(u32 *)((u8 *)th + i) ^ 2826 *(u32 *)((u8 *)th2 + i); 2827 2828 mss = skb_shinfo(p)->gso_size; 2829 2830 flush |= (len - 1) >= mss; 2831 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); 2832 2833 if (flush || skb_gro_receive(head, skb)) { 2834 mss = 1; 2835 goto out_check_final; 2836 } 2837 2838 p = *head; 2839 th2 = tcp_hdr(p); 2840 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); 2841 2842 out_check_final: 2843 flush = len < mss; 2844 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH | 2845 TCP_FLAG_RST | TCP_FLAG_SYN | 2846 TCP_FLAG_FIN)); 2847 2848 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush)) 2849 pp = head; 2850 2851 out: 2852 NAPI_GRO_CB(skb)->flush |= flush; 2853 2854 return pp; 2855 } 2856 EXPORT_SYMBOL(tcp_gro_receive); 2857 2858 int tcp_gro_complete(struct sk_buff *skb) 2859 { 2860 struct tcphdr *th = tcp_hdr(skb); 2861 2862 skb->csum_start = skb_transport_header(skb) - skb->head; 2863 skb->csum_offset = offsetof(struct tcphdr, check); 2864 skb->ip_summed = CHECKSUM_PARTIAL; 2865 2866 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 2867 2868 if (th->cwr) 2869 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 2870 2871 return 0; 2872 } 2873 EXPORT_SYMBOL(tcp_gro_complete); 2874 2875 #ifdef CONFIG_TCP_MD5SIG 2876 static unsigned long tcp_md5sig_users; 2877 static struct tcp_md5sig_pool __percpu *tcp_md5sig_pool; 2878 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock); 2879 2880 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu *pool) 2881 { 2882 int cpu; 2883 2884 for_each_possible_cpu(cpu) { 2885 struct tcp_md5sig_pool *p = per_cpu_ptr(pool, cpu); 2886 2887 if (p->md5_desc.tfm) 2888 crypto_free_hash(p->md5_desc.tfm); 2889 } 2890 free_percpu(pool); 2891 } 2892 2893 void tcp_free_md5sig_pool(void) 2894 { 2895 struct tcp_md5sig_pool __percpu *pool = NULL; 2896 2897 spin_lock_bh(&tcp_md5sig_pool_lock); 2898 if (--tcp_md5sig_users == 0) { 2899 pool = tcp_md5sig_pool; 2900 tcp_md5sig_pool = NULL; 2901 } 2902 spin_unlock_bh(&tcp_md5sig_pool_lock); 2903 if (pool) 2904 __tcp_free_md5sig_pool(pool); 2905 } 2906 EXPORT_SYMBOL(tcp_free_md5sig_pool); 2907 2908 static struct tcp_md5sig_pool __percpu * 2909 __tcp_alloc_md5sig_pool(struct sock *sk) 2910 { 2911 int cpu; 2912 struct tcp_md5sig_pool __percpu *pool; 2913 2914 pool = alloc_percpu(struct tcp_md5sig_pool); 2915 if (!pool) 2916 return NULL; 2917 2918 for_each_possible_cpu(cpu) { 2919 struct crypto_hash *hash; 2920 2921 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 2922 if (!hash || IS_ERR(hash)) 2923 goto out_free; 2924 2925 per_cpu_ptr(pool, cpu)->md5_desc.tfm = hash; 2926 } 2927 return pool; 2928 out_free: 2929 __tcp_free_md5sig_pool(pool); 2930 return NULL; 2931 } 2932 2933 struct tcp_md5sig_pool __percpu *tcp_alloc_md5sig_pool(struct sock *sk) 2934 { 2935 struct tcp_md5sig_pool __percpu *pool; 2936 int alloc = 0; 2937 2938 retry: 2939 spin_lock_bh(&tcp_md5sig_pool_lock); 2940 pool = tcp_md5sig_pool; 2941 if (tcp_md5sig_users++ == 0) { 2942 alloc = 1; 2943 spin_unlock_bh(&tcp_md5sig_pool_lock); 2944 } else if (!pool) { 2945 tcp_md5sig_users--; 2946 spin_unlock_bh(&tcp_md5sig_pool_lock); 2947 cpu_relax(); 2948 goto retry; 2949 } else 2950 spin_unlock_bh(&tcp_md5sig_pool_lock); 2951 2952 if (alloc) { 2953 /* we cannot hold spinlock here because this may sleep. */ 2954 struct tcp_md5sig_pool __percpu *p; 2955 2956 p = __tcp_alloc_md5sig_pool(sk); 2957 spin_lock_bh(&tcp_md5sig_pool_lock); 2958 if (!p) { 2959 tcp_md5sig_users--; 2960 spin_unlock_bh(&tcp_md5sig_pool_lock); 2961 return NULL; 2962 } 2963 pool = tcp_md5sig_pool; 2964 if (pool) { 2965 /* oops, it has already been assigned. */ 2966 spin_unlock_bh(&tcp_md5sig_pool_lock); 2967 __tcp_free_md5sig_pool(p); 2968 } else { 2969 tcp_md5sig_pool = pool = p; 2970 spin_unlock_bh(&tcp_md5sig_pool_lock); 2971 } 2972 } 2973 return pool; 2974 } 2975 EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 2976 2977 2978 /** 2979 * tcp_get_md5sig_pool - get md5sig_pool for this user 2980 * 2981 * We use percpu structure, so if we succeed, we exit with preemption 2982 * and BH disabled, to make sure another thread or softirq handling 2983 * wont try to get same context. 2984 */ 2985 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) 2986 { 2987 struct tcp_md5sig_pool __percpu *p; 2988 2989 local_bh_disable(); 2990 2991 spin_lock(&tcp_md5sig_pool_lock); 2992 p = tcp_md5sig_pool; 2993 if (p) 2994 tcp_md5sig_users++; 2995 spin_unlock(&tcp_md5sig_pool_lock); 2996 2997 if (p) 2998 return this_cpu_ptr(p); 2999 3000 local_bh_enable(); 3001 return NULL; 3002 } 3003 EXPORT_SYMBOL(tcp_get_md5sig_pool); 3004 3005 void tcp_put_md5sig_pool(void) 3006 { 3007 local_bh_enable(); 3008 tcp_free_md5sig_pool(); 3009 } 3010 EXPORT_SYMBOL(tcp_put_md5sig_pool); 3011 3012 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, 3013 const struct tcphdr *th) 3014 { 3015 struct scatterlist sg; 3016 struct tcphdr hdr; 3017 int err; 3018 3019 /* We are not allowed to change tcphdr, make a local copy */ 3020 memcpy(&hdr, th, sizeof(hdr)); 3021 hdr.check = 0; 3022 3023 /* options aren't included in the hash */ 3024 sg_init_one(&sg, &hdr, sizeof(hdr)); 3025 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr)); 3026 return err; 3027 } 3028 EXPORT_SYMBOL(tcp_md5_hash_header); 3029 3030 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 3031 const struct sk_buff *skb, unsigned int header_len) 3032 { 3033 struct scatterlist sg; 3034 const struct tcphdr *tp = tcp_hdr(skb); 3035 struct hash_desc *desc = &hp->md5_desc; 3036 unsigned i; 3037 const unsigned head_data_len = skb_headlen(skb) > header_len ? 3038 skb_headlen(skb) - header_len : 0; 3039 const struct skb_shared_info *shi = skb_shinfo(skb); 3040 struct sk_buff *frag_iter; 3041 3042 sg_init_table(&sg, 1); 3043 3044 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 3045 if (crypto_hash_update(desc, &sg, head_data_len)) 3046 return 1; 3047 3048 for (i = 0; i < shi->nr_frags; ++i) { 3049 const struct skb_frag_struct *f = &shi->frags[i]; 3050 struct page *page = skb_frag_page(f); 3051 sg_set_page(&sg, page, skb_frag_size(f), f->page_offset); 3052 if (crypto_hash_update(desc, &sg, skb_frag_size(f))) 3053 return 1; 3054 } 3055 3056 skb_walk_frags(skb, frag_iter) 3057 if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) 3058 return 1; 3059 3060 return 0; 3061 } 3062 EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3063 3064 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) 3065 { 3066 struct scatterlist sg; 3067 3068 sg_init_one(&sg, key->key, key->keylen); 3069 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); 3070 } 3071 EXPORT_SYMBOL(tcp_md5_hash_key); 3072 3073 #endif 3074 3075 /** 3076 * Each Responder maintains up to two secret values concurrently for 3077 * efficient secret rollover. Each secret value has 4 states: 3078 * 3079 * Generating. (tcp_secret_generating != tcp_secret_primary) 3080 * Generates new Responder-Cookies, but not yet used for primary 3081 * verification. This is a short-term state, typically lasting only 3082 * one round trip time (RTT). 3083 * 3084 * Primary. (tcp_secret_generating == tcp_secret_primary) 3085 * Used both for generation and primary verification. 3086 * 3087 * Retiring. (tcp_secret_retiring != tcp_secret_secondary) 3088 * Used for verification, until the first failure that can be 3089 * verified by the newer Generating secret. At that time, this 3090 * cookie's state is changed to Secondary, and the Generating 3091 * cookie's state is changed to Primary. This is a short-term state, 3092 * typically lasting only one round trip time (RTT). 3093 * 3094 * Secondary. (tcp_secret_retiring == tcp_secret_secondary) 3095 * Used for secondary verification, after primary verification 3096 * failures. This state lasts no more than twice the Maximum Segment 3097 * Lifetime (2MSL). Then, the secret is discarded. 3098 */ 3099 struct tcp_cookie_secret { 3100 /* The secret is divided into two parts. The digest part is the 3101 * equivalent of previously hashing a secret and saving the state, 3102 * and serves as an initialization vector (IV). The message part 3103 * serves as the trailing secret. 3104 */ 3105 u32 secrets[COOKIE_WORKSPACE_WORDS]; 3106 unsigned long expires; 3107 }; 3108 3109 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL) 3110 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2) 3111 #define TCP_SECRET_LIFE (HZ * 600) 3112 3113 static struct tcp_cookie_secret tcp_secret_one; 3114 static struct tcp_cookie_secret tcp_secret_two; 3115 3116 /* Essentially a circular list, without dynamic allocation. */ 3117 static struct tcp_cookie_secret *tcp_secret_generating; 3118 static struct tcp_cookie_secret *tcp_secret_primary; 3119 static struct tcp_cookie_secret *tcp_secret_retiring; 3120 static struct tcp_cookie_secret *tcp_secret_secondary; 3121 3122 static DEFINE_SPINLOCK(tcp_secret_locker); 3123 3124 /* Select a pseudo-random word in the cookie workspace. 3125 */ 3126 static inline u32 tcp_cookie_work(const u32 *ws, const int n) 3127 { 3128 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])]; 3129 } 3130 3131 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed. 3132 * Called in softirq context. 3133 * Returns: 0 for success. 3134 */ 3135 int tcp_cookie_generator(u32 *bakery) 3136 { 3137 unsigned long jiffy = jiffies; 3138 3139 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) { 3140 spin_lock_bh(&tcp_secret_locker); 3141 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) { 3142 /* refreshed by another */ 3143 memcpy(bakery, 3144 &tcp_secret_generating->secrets[0], 3145 COOKIE_WORKSPACE_WORDS); 3146 } else { 3147 /* still needs refreshing */ 3148 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS); 3149 3150 /* The first time, paranoia assumes that the 3151 * randomization function isn't as strong. But, 3152 * this secret initialization is delayed until 3153 * the last possible moment (packet arrival). 3154 * Although that time is observable, it is 3155 * unpredictably variable. Mash in the most 3156 * volatile clock bits available, and expire the 3157 * secret extra quickly. 3158 */ 3159 if (unlikely(tcp_secret_primary->expires == 3160 tcp_secret_secondary->expires)) { 3161 struct timespec tv; 3162 3163 getnstimeofday(&tv); 3164 bakery[COOKIE_DIGEST_WORDS+0] ^= 3165 (u32)tv.tv_nsec; 3166 3167 tcp_secret_secondary->expires = jiffy 3168 + TCP_SECRET_1MSL 3169 + (0x0f & tcp_cookie_work(bakery, 0)); 3170 } else { 3171 tcp_secret_secondary->expires = jiffy 3172 + TCP_SECRET_LIFE 3173 + (0xff & tcp_cookie_work(bakery, 1)); 3174 tcp_secret_primary->expires = jiffy 3175 + TCP_SECRET_2MSL 3176 + (0x1f & tcp_cookie_work(bakery, 2)); 3177 } 3178 memcpy(&tcp_secret_secondary->secrets[0], 3179 bakery, COOKIE_WORKSPACE_WORDS); 3180 3181 rcu_assign_pointer(tcp_secret_generating, 3182 tcp_secret_secondary); 3183 rcu_assign_pointer(tcp_secret_retiring, 3184 tcp_secret_primary); 3185 /* 3186 * Neither call_rcu() nor synchronize_rcu() needed. 3187 * Retiring data is not freed. It is replaced after 3188 * further (locked) pointer updates, and a quiet time 3189 * (minimum 1MSL, maximum LIFE - 2MSL). 3190 */ 3191 } 3192 spin_unlock_bh(&tcp_secret_locker); 3193 } else { 3194 rcu_read_lock_bh(); 3195 memcpy(bakery, 3196 &rcu_dereference(tcp_secret_generating)->secrets[0], 3197 COOKIE_WORKSPACE_WORDS); 3198 rcu_read_unlock_bh(); 3199 } 3200 return 0; 3201 } 3202 EXPORT_SYMBOL(tcp_cookie_generator); 3203 3204 void tcp_done(struct sock *sk) 3205 { 3206 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3207 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3208 3209 tcp_set_state(sk, TCP_CLOSE); 3210 tcp_clear_xmit_timers(sk); 3211 3212 sk->sk_shutdown = SHUTDOWN_MASK; 3213 3214 if (!sock_flag(sk, SOCK_DEAD)) 3215 sk->sk_state_change(sk); 3216 else 3217 inet_csk_destroy_sock(sk); 3218 } 3219 EXPORT_SYMBOL_GPL(tcp_done); 3220 3221 extern struct tcp_congestion_ops tcp_reno; 3222 3223 static __initdata unsigned long thash_entries; 3224 static int __init set_thash_entries(char *str) 3225 { 3226 if (!str) 3227 return 0; 3228 thash_entries = simple_strtoul(str, &str, 0); 3229 return 1; 3230 } 3231 __setup("thash_entries=", set_thash_entries); 3232 3233 void tcp_init_mem(struct net *net) 3234 { 3235 unsigned long limit = nr_free_buffer_pages() / 8; 3236 limit = max(limit, 128UL); 3237 net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3; 3238 net->ipv4.sysctl_tcp_mem[1] = limit; 3239 net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2; 3240 } 3241 3242 void __init tcp_init(void) 3243 { 3244 struct sk_buff *skb = NULL; 3245 unsigned long limit; 3246 int max_rshare, max_wshare, cnt; 3247 unsigned int i; 3248 unsigned long jiffy = jiffies; 3249 3250 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); 3251 3252 percpu_counter_init(&tcp_sockets_allocated, 0); 3253 percpu_counter_init(&tcp_orphan_count, 0); 3254 tcp_hashinfo.bind_bucket_cachep = 3255 kmem_cache_create("tcp_bind_bucket", 3256 sizeof(struct inet_bind_bucket), 0, 3257 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3258 3259 /* Size and allocate the main established and bind bucket 3260 * hash tables. 3261 * 3262 * The methodology is similar to that of the buffer cache. 3263 */ 3264 tcp_hashinfo.ehash = 3265 alloc_large_system_hash("TCP established", 3266 sizeof(struct inet_ehash_bucket), 3267 thash_entries, 3268 (totalram_pages >= 128 * 1024) ? 3269 13 : 15, 3270 0, 3271 NULL, 3272 &tcp_hashinfo.ehash_mask, 3273 thash_entries ? 0 : 512 * 1024); 3274 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) { 3275 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3276 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i); 3277 } 3278 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3279 panic("TCP: failed to alloc ehash_locks"); 3280 tcp_hashinfo.bhash = 3281 alloc_large_system_hash("TCP bind", 3282 sizeof(struct inet_bind_hashbucket), 3283 tcp_hashinfo.ehash_mask + 1, 3284 (totalram_pages >= 128 * 1024) ? 3285 13 : 15, 3286 0, 3287 &tcp_hashinfo.bhash_size, 3288 NULL, 3289 64 * 1024); 3290 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; 3291 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3292 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3293 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3294 } 3295 3296 3297 cnt = tcp_hashinfo.ehash_mask + 1; 3298 3299 tcp_death_row.sysctl_max_tw_buckets = cnt / 2; 3300 sysctl_tcp_max_orphans = cnt / 2; 3301 sysctl_max_syn_backlog = max(128, cnt / 256); 3302 3303 tcp_init_mem(&init_net); 3304 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3305 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); 3306 max_wshare = min(4UL*1024*1024, limit); 3307 max_rshare = min(6UL*1024*1024, limit); 3308 3309 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3310 sysctl_tcp_wmem[1] = 16*1024; 3311 sysctl_tcp_wmem[2] = max(64*1024, max_wshare); 3312 3313 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3314 sysctl_tcp_rmem[1] = 87380; 3315 sysctl_tcp_rmem[2] = max(87380, max_rshare); 3316 3317 pr_info("Hash tables configured (established %u bind %u)\n", 3318 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3319 3320 tcp_register_congestion_control(&tcp_reno); 3321 3322 memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets)); 3323 memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets)); 3324 tcp_secret_one.expires = jiffy; /* past due */ 3325 tcp_secret_two.expires = jiffy; /* past due */ 3326 tcp_secret_generating = &tcp_secret_one; 3327 tcp_secret_primary = &tcp_secret_one; 3328 tcp_secret_retiring = &tcp_secret_two; 3329 tcp_secret_secondary = &tcp_secret_two; 3330 } 3331