1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Implementation of the Transmission Control Protocol(TCP). 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Mark Evans, <evansmp@uhura.aston.ac.uk> 11 * Corey Minyard <wf-rch!minyard@relay.EU.net> 12 * Florian La Roche, <flla@stud.uni-sb.de> 13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> 14 * Linus Torvalds, <torvalds@cs.helsinki.fi> 15 * Alan Cox, <gw4pts@gw4pts.ampr.org> 16 * Matthew Dillon, <dillon@apollo.west.oic.com> 17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 18 * Jorge Cwik, <jorge@laser.satlink.net> 19 * 20 * Fixes: 21 * Alan Cox : Numerous verify_area() calls 22 * Alan Cox : Set the ACK bit on a reset 23 * Alan Cox : Stopped it crashing if it closed while 24 * sk->inuse=1 and was trying to connect 25 * (tcp_err()). 26 * Alan Cox : All icmp error handling was broken 27 * pointers passed where wrong and the 28 * socket was looked up backwards. Nobody 29 * tested any icmp error code obviously. 30 * Alan Cox : tcp_err() now handled properly. It 31 * wakes people on errors. poll 32 * behaves and the icmp error race 33 * has gone by moving it into sock.c 34 * Alan Cox : tcp_send_reset() fixed to work for 35 * everything not just packets for 36 * unknown sockets. 37 * Alan Cox : tcp option processing. 38 * Alan Cox : Reset tweaked (still not 100%) [Had 39 * syn rule wrong] 40 * Herp Rosmanith : More reset fixes 41 * Alan Cox : No longer acks invalid rst frames. 42 * Acking any kind of RST is right out. 43 * Alan Cox : Sets an ignore me flag on an rst 44 * receive otherwise odd bits of prattle 45 * escape still 46 * Alan Cox : Fixed another acking RST frame bug. 47 * Should stop LAN workplace lockups. 48 * Alan Cox : Some tidyups using the new skb list 49 * facilities 50 * Alan Cox : sk->keepopen now seems to work 51 * Alan Cox : Pulls options out correctly on accepts 52 * Alan Cox : Fixed assorted sk->rqueue->next errors 53 * Alan Cox : PSH doesn't end a TCP read. Switched a 54 * bit to skb ops. 55 * Alan Cox : Tidied tcp_data to avoid a potential 56 * nasty. 57 * Alan Cox : Added some better commenting, as the 58 * tcp is hard to follow 59 * Alan Cox : Removed incorrect check for 20 * psh 60 * Michael O'Reilly : ack < copied bug fix. 61 * Johannes Stille : Misc tcp fixes (not all in yet). 62 * Alan Cox : FIN with no memory -> CRASH 63 * Alan Cox : Added socket option proto entries. 64 * Also added awareness of them to accept. 65 * Alan Cox : Added TCP options (SOL_TCP) 66 * Alan Cox : Switched wakeup calls to callbacks, 67 * so the kernel can layer network 68 * sockets. 69 * Alan Cox : Use ip_tos/ip_ttl settings. 70 * Alan Cox : Handle FIN (more) properly (we hope). 71 * Alan Cox : RST frames sent on unsynchronised 72 * state ack error. 73 * Alan Cox : Put in missing check for SYN bit. 74 * Alan Cox : Added tcp_select_window() aka NET2E 75 * window non shrink trick. 76 * Alan Cox : Added a couple of small NET2E timer 77 * fixes 78 * Charles Hedrick : TCP fixes 79 * Toomas Tamm : TCP window fixes 80 * Alan Cox : Small URG fix to rlogin ^C ack fight 81 * Charles Hedrick : Rewrote most of it to actually work 82 * Linus : Rewrote tcp_read() and URG handling 83 * completely 84 * Gerhard Koerting: Fixed some missing timer handling 85 * Matthew Dillon : Reworked TCP machine states as per RFC 86 * Gerhard Koerting: PC/TCP workarounds 87 * Adam Caldwell : Assorted timer/timing errors 88 * Matthew Dillon : Fixed another RST bug 89 * Alan Cox : Move to kernel side addressing changes. 90 * Alan Cox : Beginning work on TCP fastpathing 91 * (not yet usable) 92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine. 93 * Alan Cox : TCP fast path debugging 94 * Alan Cox : Window clamping 95 * Michael Riepe : Bug in tcp_check() 96 * Matt Dillon : More TCP improvements and RST bug fixes 97 * Matt Dillon : Yet more small nasties remove from the 98 * TCP code (Be very nice to this man if 99 * tcp finally works 100%) 8) 100 * Alan Cox : BSD accept semantics. 101 * Alan Cox : Reset on closedown bug. 102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto(). 103 * Michael Pall : Handle poll() after URG properly in 104 * all cases. 105 * Michael Pall : Undo the last fix in tcp_read_urg() 106 * (multi URG PUSH broke rlogin). 107 * Michael Pall : Fix the multi URG PUSH problem in 108 * tcp_readable(), poll() after URG 109 * works now. 110 * Michael Pall : recv(...,MSG_OOB) never blocks in the 111 * BSD api. 112 * Alan Cox : Changed the semantics of sk->socket to 113 * fix a race and a signal problem with 114 * accept() and async I/O. 115 * Alan Cox : Relaxed the rules on tcp_sendto(). 116 * Yury Shevchuk : Really fixed accept() blocking problem. 117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for 118 * clients/servers which listen in on 119 * fixed ports. 120 * Alan Cox : Cleaned the above up and shrank it to 121 * a sensible code size. 122 * Alan Cox : Self connect lockup fix. 123 * Alan Cox : No connect to multicast. 124 * Ross Biro : Close unaccepted children on master 125 * socket close. 126 * Alan Cox : Reset tracing code. 127 * Alan Cox : Spurious resets on shutdown. 128 * Alan Cox : Giant 15 minute/60 second timer error 129 * Alan Cox : Small whoops in polling before an 130 * accept. 131 * Alan Cox : Kept the state trace facility since 132 * it's handy for debugging. 133 * Alan Cox : More reset handler fixes. 134 * Alan Cox : Started rewriting the code based on 135 * the RFC's for other useful protocol 136 * references see: Comer, KA9Q NOS, and 137 * for a reference on the difference 138 * between specifications and how BSD 139 * works see the 4.4lite source. 140 * A.N.Kuznetsov : Don't time wait on completion of tidy 141 * close. 142 * Linus Torvalds : Fin/Shutdown & copied_seq changes. 143 * Linus Torvalds : Fixed BSD port reuse to work first syn 144 * Alan Cox : Reimplemented timers as per the RFC 145 * and using multiple timers for sanity. 146 * Alan Cox : Small bug fixes, and a lot of new 147 * comments. 148 * Alan Cox : Fixed dual reader crash by locking 149 * the buffers (much like datagram.c) 150 * Alan Cox : Fixed stuck sockets in probe. A probe 151 * now gets fed up of retrying without 152 * (even a no space) answer. 153 * Alan Cox : Extracted closing code better 154 * Alan Cox : Fixed the closing state machine to 155 * resemble the RFC. 156 * Alan Cox : More 'per spec' fixes. 157 * Jorge Cwik : Even faster checksumming. 158 * Alan Cox : tcp_data() doesn't ack illegal PSH 159 * only frames. At least one pc tcp stack 160 * generates them. 161 * Alan Cox : Cache last socket. 162 * Alan Cox : Per route irtt. 163 * Matt Day : poll()->select() match BSD precisely on error 164 * Alan Cox : New buffers 165 * Marc Tamsky : Various sk->prot->retransmits and 166 * sk->retransmits misupdating fixed. 167 * Fixed tcp_write_timeout: stuck close, 168 * and TCP syn retries gets used now. 169 * Mark Yarvis : In tcp_read_wakeup(), don't send an 170 * ack if state is TCP_CLOSED. 171 * Alan Cox : Look up device on a retransmit - routes may 172 * change. Doesn't yet cope with MSS shrink right 173 * but it's a start! 174 * Marc Tamsky : Closing in closing fixes. 175 * Mike Shaver : RFC1122 verifications. 176 * Alan Cox : rcv_saddr errors. 177 * Alan Cox : Block double connect(). 178 * Alan Cox : Small hooks for enSKIP. 179 * Alexey Kuznetsov: Path MTU discovery. 180 * Alan Cox : Support soft errors. 181 * Alan Cox : Fix MTU discovery pathological case 182 * when the remote claims no mtu! 183 * Marc Tamsky : TCP_CLOSE fix. 184 * Colin (G3TNE) : Send a reset on syn ack replies in 185 * window but wrong (fixes NT lpd problems) 186 * Pedro Roque : Better TCP window handling, delayed ack. 187 * Joerg Reuter : No modification of locked buffers in 188 * tcp_do_retransmit() 189 * Eric Schenk : Changed receiver side silly window 190 * avoidance algorithm to BSD style 191 * algorithm. This doubles throughput 192 * against machines running Solaris, 193 * and seems to result in general 194 * improvement. 195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD 196 * Willy Konynenberg : Transparent proxying support. 197 * Mike McLagan : Routing by source 198 * Keith Owens : Do proper merging with partial SKB's in 199 * tcp_do_sendmsg to avoid burstiness. 200 * Eric Schenk : Fix fast close down bug with 201 * shutdown() followed by close(). 202 * Andi Kleen : Make poll agree with SIGIO 203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and 204 * lingertime == 0 (RFC 793 ABORT Call) 205 * Hirokazu Takahashi : Use copy_from_user() instead of 206 * csum_and_copy_from_user() if possible. 207 * 208 * This program is free software; you can redistribute it and/or 209 * modify it under the terms of the GNU General Public License 210 * as published by the Free Software Foundation; either version 211 * 2 of the License, or(at your option) any later version. 212 * 213 * Description of States: 214 * 215 * TCP_SYN_SENT sent a connection request, waiting for ack 216 * 217 * TCP_SYN_RECV received a connection request, sent ack, 218 * waiting for final ack in three-way handshake. 219 * 220 * TCP_ESTABLISHED connection established 221 * 222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete 223 * transmission of remaining buffered data 224 * 225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote 226 * to shutdown 227 * 228 * TCP_CLOSING both sides have shutdown but we still have 229 * data we have to finish sending 230 * 231 * TCP_TIME_WAIT timeout to catch resent junk before entering 232 * closed, can only be entered from FIN_WAIT2 233 * or CLOSING. Required because the other end 234 * may not have gotten our last ACK causing it 235 * to retransmit the data packet (which we ignore) 236 * 237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for 238 * us to finish writing our data and to shutdown 239 * (we have to close() to move on to LAST_ACK) 240 * 241 * TCP_LAST_ACK out side has shutdown after remote has 242 * shutdown. There may still be data in our 243 * buffer that we have to finish sending 244 * 245 * TCP_CLOSE socket is finished 246 */ 247 248 #include <linux/kernel.h> 249 #include <linux/module.h> 250 #include <linux/types.h> 251 #include <linux/fcntl.h> 252 #include <linux/poll.h> 253 #include <linux/init.h> 254 #include <linux/fs.h> 255 #include <linux/skbuff.h> 256 #include <linux/scatterlist.h> 257 #include <linux/splice.h> 258 #include <linux/net.h> 259 #include <linux/socket.h> 260 #include <linux/random.h> 261 #include <linux/bootmem.h> 262 #include <linux/highmem.h> 263 #include <linux/swap.h> 264 #include <linux/cache.h> 265 #include <linux/err.h> 266 #include <linux/crypto.h> 267 #include <linux/time.h> 268 #include <linux/slab.h> 269 270 #include <net/icmp.h> 271 #include <net/tcp.h> 272 #include <net/xfrm.h> 273 #include <net/ip.h> 274 #include <net/netdma.h> 275 #include <net/sock.h> 276 277 #include <asm/uaccess.h> 278 #include <asm/ioctls.h> 279 280 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; 281 282 struct percpu_counter tcp_orphan_count; 283 EXPORT_SYMBOL_GPL(tcp_orphan_count); 284 285 int sysctl_tcp_mem[3] __read_mostly; 286 int sysctl_tcp_wmem[3] __read_mostly; 287 int sysctl_tcp_rmem[3] __read_mostly; 288 289 EXPORT_SYMBOL(sysctl_tcp_mem); 290 EXPORT_SYMBOL(sysctl_tcp_rmem); 291 EXPORT_SYMBOL(sysctl_tcp_wmem); 292 293 atomic_t tcp_memory_allocated; /* Current allocated memory. */ 294 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; 318 319 EXPORT_SYMBOL(tcp_memory_pressure); 320 321 void tcp_enter_memory_pressure(struct sock *sk) 322 { 323 if (!tcp_memory_pressure) { 324 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); 325 tcp_memory_pressure = 1; 326 } 327 } 328 329 EXPORT_SYMBOL(tcp_enter_memory_pressure); 330 331 /* Convert seconds to retransmits based on initial and max timeout */ 332 static u8 secs_to_retrans(int seconds, int timeout, int rto_max) 333 { 334 u8 res = 0; 335 336 if (seconds > 0) { 337 int period = timeout; 338 339 res = 1; 340 while (seconds > period && res < 255) { 341 res++; 342 timeout <<= 1; 343 if (timeout > rto_max) 344 timeout = rto_max; 345 period += timeout; 346 } 347 } 348 return res; 349 } 350 351 /* Convert retransmits to seconds based on initial and max timeout */ 352 static int retrans_to_secs(u8 retrans, int timeout, int rto_max) 353 { 354 int period = 0; 355 356 if (retrans > 0) { 357 period = timeout; 358 while (--retrans) { 359 timeout <<= 1; 360 if (timeout > rto_max) 361 timeout = rto_max; 362 period += timeout; 363 } 364 } 365 return period; 366 } 367 368 /* 369 * Wait for a TCP event. 370 * 371 * Note that we don't need to lock the socket, as the upper poll layers 372 * take care of normal races (between the test and the event) and we don't 373 * go look at any of the socket buffers directly. 374 */ 375 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 376 { 377 unsigned int mask; 378 struct sock *sk = sock->sk; 379 struct tcp_sock *tp = tcp_sk(sk); 380 381 sock_poll_wait(file, sk_sleep(sk), wait); 382 if (sk->sk_state == TCP_LISTEN) 383 return inet_csk_listen_poll(sk); 384 385 /* Socket is not locked. We are protected from async events 386 * by poll logic and correct handling of state changes 387 * made by other threads is impossible in any case. 388 */ 389 390 mask = 0; 391 if (sk->sk_err) 392 mask = POLLERR; 393 394 /* 395 * POLLHUP is certainly not done right. But poll() doesn't 396 * have a notion of HUP in just one direction, and for a 397 * socket the read side is more interesting. 398 * 399 * Some poll() documentation says that POLLHUP is incompatible 400 * with the POLLOUT/POLLWR flags, so somebody should check this 401 * all. But careful, it tends to be safer to return too many 402 * bits than too few, and you can easily break real applications 403 * if you don't tell them that something has hung up! 404 * 405 * Check-me. 406 * 407 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and 408 * our fs/select.c). It means that after we received EOF, 409 * poll always returns immediately, making impossible poll() on write() 410 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP 411 * if and only if shutdown has been made in both directions. 412 * Actually, it is interesting to look how Solaris and DUX 413 * solve this dilemma. I would prefer, if POLLHUP were maskable, 414 * then we could set it on SND_SHUTDOWN. BTW examples given 415 * in Stevens' books assume exactly this behaviour, it explains 416 * why POLLHUP is incompatible with POLLOUT. --ANK 417 * 418 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 419 * blocking on fresh not-connected or disconnected socket. --ANK 420 */ 421 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) 422 mask |= POLLHUP; 423 if (sk->sk_shutdown & RCV_SHUTDOWN) 424 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 425 426 /* Connected? */ 427 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { 428 int target = sock_rcvlowat(sk, 0, INT_MAX); 429 430 if (tp->urg_seq == tp->copied_seq && 431 !sock_flag(sk, SOCK_URGINLINE) && 432 tp->urg_data) 433 target++; 434 435 /* Potential race condition. If read of tp below will 436 * escape above sk->sk_state, we can be illegally awaken 437 * in SYN_* states. */ 438 if (tp->rcv_nxt - tp->copied_seq >= target) 439 mask |= POLLIN | POLLRDNORM; 440 441 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 442 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 443 mask |= POLLOUT | POLLWRNORM; 444 } else { /* send SIGIO later */ 445 set_bit(SOCK_ASYNC_NOSPACE, 446 &sk->sk_socket->flags); 447 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 448 449 /* Race breaker. If space is freed after 450 * wspace test but before the flags are set, 451 * IO signal will be lost. 452 */ 453 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) 454 mask |= POLLOUT | POLLWRNORM; 455 } 456 } 457 458 if (tp->urg_data & TCP_URG_VALID) 459 mask |= POLLPRI; 460 } 461 return mask; 462 } 463 464 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 465 { 466 struct tcp_sock *tp = tcp_sk(sk); 467 int answ; 468 469 switch (cmd) { 470 case SIOCINQ: 471 if (sk->sk_state == TCP_LISTEN) 472 return -EINVAL; 473 474 lock_sock(sk); 475 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 476 answ = 0; 477 else if (sock_flag(sk, SOCK_URGINLINE) || 478 !tp->urg_data || 479 before(tp->urg_seq, tp->copied_seq) || 480 !before(tp->urg_seq, tp->rcv_nxt)) { 481 struct sk_buff *skb; 482 483 answ = tp->rcv_nxt - tp->copied_seq; 484 485 /* Subtract 1, if FIN is in queue. */ 486 skb = skb_peek_tail(&sk->sk_receive_queue); 487 if (answ && skb) 488 answ -= tcp_hdr(skb)->fin; 489 } else 490 answ = tp->urg_seq - tp->copied_seq; 491 release_sock(sk); 492 break; 493 case SIOCATMARK: 494 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 495 break; 496 case SIOCOUTQ: 497 if (sk->sk_state == TCP_LISTEN) 498 return -EINVAL; 499 500 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 501 answ = 0; 502 else 503 answ = tp->write_seq - tp->snd_una; 504 break; 505 default: 506 return -ENOIOCTLCMD; 507 } 508 509 return put_user(answ, (int __user *)arg); 510 } 511 512 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 513 { 514 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH; 515 tp->pushed_seq = tp->write_seq; 516 } 517 518 static inline int forced_push(struct tcp_sock *tp) 519 { 520 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 521 } 522 523 static inline void skb_entail(struct sock *sk, struct sk_buff *skb) 524 { 525 struct tcp_sock *tp = tcp_sk(sk); 526 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 527 528 skb->csum = 0; 529 tcb->seq = tcb->end_seq = tp->write_seq; 530 tcb->flags = TCPCB_FLAG_ACK; 531 tcb->sacked = 0; 532 skb_header_release(skb); 533 tcp_add_write_queue_tail(sk, skb); 534 sk->sk_wmem_queued += skb->truesize; 535 sk_mem_charge(sk, skb->truesize); 536 if (tp->nonagle & TCP_NAGLE_PUSH) 537 tp->nonagle &= ~TCP_NAGLE_PUSH; 538 } 539 540 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) 541 { 542 if (flags & MSG_OOB) 543 tp->snd_up = tp->write_seq; 544 } 545 546 static inline void tcp_push(struct sock *sk, int flags, int mss_now, 547 int nonagle) 548 { 549 if (tcp_send_head(sk)) { 550 struct tcp_sock *tp = tcp_sk(sk); 551 552 if (!(flags & MSG_MORE) || forced_push(tp)) 553 tcp_mark_push(tp, tcp_write_queue_tail(sk)); 554 555 tcp_mark_urg(tp, flags); 556 __tcp_push_pending_frames(sk, mss_now, 557 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); 558 } 559 } 560 561 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 562 unsigned int offset, size_t len) 563 { 564 struct tcp_splice_state *tss = rd_desc->arg.data; 565 int ret; 566 567 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len), 568 tss->flags); 569 if (ret > 0) 570 rd_desc->count -= ret; 571 return ret; 572 } 573 574 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 575 { 576 /* Store TCP splice context information in read_descriptor_t. */ 577 read_descriptor_t rd_desc = { 578 .arg.data = tss, 579 .count = tss->len, 580 }; 581 582 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 583 } 584 585 /** 586 * tcp_splice_read - splice data from TCP socket to a pipe 587 * @sock: socket to splice from 588 * @ppos: position (not valid) 589 * @pipe: pipe to splice to 590 * @len: number of bytes to splice 591 * @flags: splice modifier flags 592 * 593 * Description: 594 * Will read pages from given socket and fill them into a pipe. 595 * 596 **/ 597 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 598 struct pipe_inode_info *pipe, size_t len, 599 unsigned int flags) 600 { 601 struct sock *sk = sock->sk; 602 struct tcp_splice_state tss = { 603 .pipe = pipe, 604 .len = len, 605 .flags = flags, 606 }; 607 long timeo; 608 ssize_t spliced; 609 int ret; 610 611 /* 612 * We can't seek on a socket input 613 */ 614 if (unlikely(*ppos)) 615 return -ESPIPE; 616 617 ret = spliced = 0; 618 619 lock_sock(sk); 620 621 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); 622 while (tss.len) { 623 ret = __tcp_splice_read(sk, &tss); 624 if (ret < 0) 625 break; 626 else if (!ret) { 627 if (spliced) 628 break; 629 if (sock_flag(sk, SOCK_DONE)) 630 break; 631 if (sk->sk_err) { 632 ret = sock_error(sk); 633 break; 634 } 635 if (sk->sk_shutdown & RCV_SHUTDOWN) 636 break; 637 if (sk->sk_state == TCP_CLOSE) { 638 /* 639 * This occurs when user tries to read 640 * from never connected socket. 641 */ 642 if (!sock_flag(sk, SOCK_DONE)) 643 ret = -ENOTCONN; 644 break; 645 } 646 if (!timeo) { 647 ret = -EAGAIN; 648 break; 649 } 650 sk_wait_data(sk, &timeo); 651 if (signal_pending(current)) { 652 ret = sock_intr_errno(timeo); 653 break; 654 } 655 continue; 656 } 657 tss.len -= ret; 658 spliced += ret; 659 660 if (!timeo) 661 break; 662 release_sock(sk); 663 lock_sock(sk); 664 665 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 666 (sk->sk_shutdown & RCV_SHUTDOWN) || 667 signal_pending(current)) 668 break; 669 } 670 671 release_sock(sk); 672 673 if (spliced) 674 return spliced; 675 676 return ret; 677 } 678 679 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) 680 { 681 struct sk_buff *skb; 682 683 /* The TCP header must be at least 32-bit aligned. */ 684 size = ALIGN(size, 4); 685 686 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 687 if (skb) { 688 if (sk_wmem_schedule(sk, skb->truesize)) { 689 /* 690 * Make sure that we have exactly size bytes 691 * available to the caller, no more, no less. 692 */ 693 skb_reserve(skb, skb_tailroom(skb) - size); 694 return skb; 695 } 696 __kfree_skb(skb); 697 } else { 698 sk->sk_prot->enter_memory_pressure(sk); 699 sk_stream_moderate_sndbuf(sk); 700 } 701 return NULL; 702 } 703 704 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, 705 int large_allowed) 706 { 707 struct tcp_sock *tp = tcp_sk(sk); 708 u32 xmit_size_goal, old_size_goal; 709 710 xmit_size_goal = mss_now; 711 712 if (large_allowed && sk_can_gso(sk)) { 713 xmit_size_goal = ((sk->sk_gso_max_size - 1) - 714 inet_csk(sk)->icsk_af_ops->net_header_len - 715 inet_csk(sk)->icsk_ext_hdr_len - 716 tp->tcp_header_len); 717 718 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal); 719 720 /* We try hard to avoid divides here */ 721 old_size_goal = tp->xmit_size_goal_segs * mss_now; 722 723 if (likely(old_size_goal <= xmit_size_goal && 724 old_size_goal + mss_now > xmit_size_goal)) { 725 xmit_size_goal = old_size_goal; 726 } else { 727 tp->xmit_size_goal_segs = xmit_size_goal / mss_now; 728 xmit_size_goal = tp->xmit_size_goal_segs * mss_now; 729 } 730 } 731 732 return max(xmit_size_goal, mss_now); 733 } 734 735 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) 736 { 737 int mss_now; 738 739 mss_now = tcp_current_mss(sk); 740 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); 741 742 return mss_now; 743 } 744 745 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, 746 size_t psize, int flags) 747 { 748 struct tcp_sock *tp = tcp_sk(sk); 749 int mss_now, size_goal; 750 int err; 751 ssize_t copied; 752 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 753 754 /* Wait for a connection to finish. */ 755 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 756 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 757 goto out_err; 758 759 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 760 761 mss_now = tcp_send_mss(sk, &size_goal, flags); 762 copied = 0; 763 764 err = -EPIPE; 765 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 766 goto out_err; 767 768 while (psize > 0) { 769 struct sk_buff *skb = tcp_write_queue_tail(sk); 770 struct page *page = pages[poffset / PAGE_SIZE]; 771 int copy, i, can_coalesce; 772 int offset = poffset % PAGE_SIZE; 773 int size = min_t(size_t, psize, PAGE_SIZE - offset); 774 775 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { 776 new_segment: 777 if (!sk_stream_memory_free(sk)) 778 goto wait_for_sndbuf; 779 780 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); 781 if (!skb) 782 goto wait_for_memory; 783 784 skb_entail(sk, skb); 785 copy = size_goal; 786 } 787 788 if (copy > size) 789 copy = size; 790 791 i = skb_shinfo(skb)->nr_frags; 792 can_coalesce = skb_can_coalesce(skb, i, page, offset); 793 if (!can_coalesce && i >= MAX_SKB_FRAGS) { 794 tcp_mark_push(tp, skb); 795 goto new_segment; 796 } 797 if (!sk_wmem_schedule(sk, copy)) 798 goto wait_for_memory; 799 800 if (can_coalesce) { 801 skb_shinfo(skb)->frags[i - 1].size += copy; 802 } else { 803 get_page(page); 804 skb_fill_page_desc(skb, i, page, offset, copy); 805 } 806 807 skb->len += copy; 808 skb->data_len += copy; 809 skb->truesize += copy; 810 sk->sk_wmem_queued += copy; 811 sk_mem_charge(sk, copy); 812 skb->ip_summed = CHECKSUM_PARTIAL; 813 tp->write_seq += copy; 814 TCP_SKB_CB(skb)->end_seq += copy; 815 skb_shinfo(skb)->gso_segs = 0; 816 817 if (!copied) 818 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 819 820 copied += copy; 821 poffset += copy; 822 if (!(psize -= copy)) 823 goto out; 824 825 if (skb->len < size_goal || (flags & MSG_OOB)) 826 continue; 827 828 if (forced_push(tp)) { 829 tcp_mark_push(tp, skb); 830 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 831 } else if (skb == tcp_send_head(sk)) 832 tcp_push_one(sk, mss_now); 833 continue; 834 835 wait_for_sndbuf: 836 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 837 wait_for_memory: 838 if (copied) 839 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 840 841 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 842 goto do_error; 843 844 mss_now = tcp_send_mss(sk, &size_goal, flags); 845 } 846 847 out: 848 if (copied) 849 tcp_push(sk, flags, mss_now, tp->nonagle); 850 return copied; 851 852 do_error: 853 if (copied) 854 goto out; 855 out_err: 856 return sk_stream_error(sk, flags, err); 857 } 858 859 ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, 860 size_t size, int flags) 861 { 862 ssize_t res; 863 struct sock *sk = sock->sk; 864 865 if (!(sk->sk_route_caps & NETIF_F_SG) || 866 !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) 867 return sock_no_sendpage(sock, page, offset, size, flags); 868 869 lock_sock(sk); 870 TCP_CHECK_TIMER(sk); 871 res = do_tcp_sendpages(sk, &page, offset, size, flags); 872 TCP_CHECK_TIMER(sk); 873 release_sock(sk); 874 return res; 875 } 876 877 #define TCP_PAGE(sk) (sk->sk_sndmsg_page) 878 #define TCP_OFF(sk) (sk->sk_sndmsg_off) 879 880 static inline int select_size(struct sock *sk, int sg) 881 { 882 struct tcp_sock *tp = tcp_sk(sk); 883 int tmp = tp->mss_cache; 884 885 if (sg) { 886 if (sk_can_gso(sk)) 887 tmp = 0; 888 else { 889 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); 890 891 if (tmp >= pgbreak && 892 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) 893 tmp = pgbreak; 894 } 895 } 896 897 return tmp; 898 } 899 900 int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, 901 size_t size) 902 { 903 struct sock *sk = sock->sk; 904 struct iovec *iov; 905 struct tcp_sock *tp = tcp_sk(sk); 906 struct sk_buff *skb; 907 int iovlen, flags; 908 int mss_now, size_goal; 909 int sg, err, copied; 910 long timeo; 911 912 lock_sock(sk); 913 TCP_CHECK_TIMER(sk); 914 915 flags = msg->msg_flags; 916 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 917 918 /* Wait for a connection to finish. */ 919 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 920 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 921 goto out_err; 922 923 /* This should be in poll */ 924 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 925 926 mss_now = tcp_send_mss(sk, &size_goal, flags); 927 928 /* Ok commence sending. */ 929 iovlen = msg->msg_iovlen; 930 iov = msg->msg_iov; 931 copied = 0; 932 933 err = -EPIPE; 934 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 935 goto out_err; 936 937 sg = sk->sk_route_caps & NETIF_F_SG; 938 939 while (--iovlen >= 0) { 940 int seglen = iov->iov_len; 941 unsigned char __user *from = iov->iov_base; 942 943 iov++; 944 945 while (seglen > 0) { 946 int copy = 0; 947 int max = size_goal; 948 949 skb = tcp_write_queue_tail(sk); 950 if (tcp_send_head(sk)) { 951 if (skb->ip_summed == CHECKSUM_NONE) 952 max = mss_now; 953 copy = max - skb->len; 954 } 955 956 if (copy <= 0) { 957 new_segment: 958 /* Allocate new segment. If the interface is SG, 959 * allocate skb fitting to single page. 960 */ 961 if (!sk_stream_memory_free(sk)) 962 goto wait_for_sndbuf; 963 964 skb = sk_stream_alloc_skb(sk, 965 select_size(sk, sg), 966 sk->sk_allocation); 967 if (!skb) 968 goto wait_for_memory; 969 970 /* 971 * Check whether we can use HW checksum. 972 */ 973 if (sk->sk_route_caps & NETIF_F_ALL_CSUM) 974 skb->ip_summed = CHECKSUM_PARTIAL; 975 976 skb_entail(sk, skb); 977 copy = size_goal; 978 max = size_goal; 979 } 980 981 /* Try to append data to the end of skb. */ 982 if (copy > seglen) 983 copy = seglen; 984 985 /* Where to copy to? */ 986 if (skb_tailroom(skb) > 0) { 987 /* We have some space in skb head. Superb! */ 988 if (copy > skb_tailroom(skb)) 989 copy = skb_tailroom(skb); 990 if ((err = skb_add_data(skb, from, copy)) != 0) 991 goto do_fault; 992 } else { 993 int merge = 0; 994 int i = skb_shinfo(skb)->nr_frags; 995 struct page *page = TCP_PAGE(sk); 996 int off = TCP_OFF(sk); 997 998 if (skb_can_coalesce(skb, i, page, off) && 999 off != PAGE_SIZE) { 1000 /* We can extend the last page 1001 * fragment. */ 1002 merge = 1; 1003 } else if (i == MAX_SKB_FRAGS || !sg) { 1004 /* Need to add new fragment and cannot 1005 * do this because interface is non-SG, 1006 * or because all the page slots are 1007 * busy. */ 1008 tcp_mark_push(tp, skb); 1009 goto new_segment; 1010 } else if (page) { 1011 if (off == PAGE_SIZE) { 1012 put_page(page); 1013 TCP_PAGE(sk) = page = NULL; 1014 off = 0; 1015 } 1016 } else 1017 off = 0; 1018 1019 if (copy > PAGE_SIZE - off) 1020 copy = PAGE_SIZE - off; 1021 1022 if (!sk_wmem_schedule(sk, copy)) 1023 goto wait_for_memory; 1024 1025 if (!page) { 1026 /* Allocate new cache page. */ 1027 if (!(page = sk_stream_alloc_page(sk))) 1028 goto wait_for_memory; 1029 } 1030 1031 /* Time to copy data. We are close to 1032 * the end! */ 1033 err = skb_copy_to_page(sk, from, skb, page, 1034 off, copy); 1035 if (err) { 1036 /* If this page was new, give it to the 1037 * socket so it does not get leaked. 1038 */ 1039 if (!TCP_PAGE(sk)) { 1040 TCP_PAGE(sk) = page; 1041 TCP_OFF(sk) = 0; 1042 } 1043 goto do_error; 1044 } 1045 1046 /* Update the skb. */ 1047 if (merge) { 1048 skb_shinfo(skb)->frags[i - 1].size += 1049 copy; 1050 } else { 1051 skb_fill_page_desc(skb, i, page, off, copy); 1052 if (TCP_PAGE(sk)) { 1053 get_page(page); 1054 } else if (off + copy < PAGE_SIZE) { 1055 get_page(page); 1056 TCP_PAGE(sk) = page; 1057 } 1058 } 1059 1060 TCP_OFF(sk) = off + copy; 1061 } 1062 1063 if (!copied) 1064 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 1065 1066 tp->write_seq += copy; 1067 TCP_SKB_CB(skb)->end_seq += copy; 1068 skb_shinfo(skb)->gso_segs = 0; 1069 1070 from += copy; 1071 copied += copy; 1072 if ((seglen -= copy) == 0 && iovlen == 0) 1073 goto out; 1074 1075 if (skb->len < max || (flags & MSG_OOB)) 1076 continue; 1077 1078 if (forced_push(tp)) { 1079 tcp_mark_push(tp, skb); 1080 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1081 } else if (skb == tcp_send_head(sk)) 1082 tcp_push_one(sk, mss_now); 1083 continue; 1084 1085 wait_for_sndbuf: 1086 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1087 wait_for_memory: 1088 if (copied) 1089 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 1090 1091 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 1092 goto do_error; 1093 1094 mss_now = tcp_send_mss(sk, &size_goal, flags); 1095 } 1096 } 1097 1098 out: 1099 if (copied) 1100 tcp_push(sk, flags, mss_now, tp->nonagle); 1101 TCP_CHECK_TIMER(sk); 1102 release_sock(sk); 1103 return copied; 1104 1105 do_fault: 1106 if (!skb->len) { 1107 tcp_unlink_write_queue(skb, sk); 1108 /* It is the one place in all of TCP, except connection 1109 * reset, where we can be unlinking the send_head. 1110 */ 1111 tcp_check_send_head(sk, skb); 1112 sk_wmem_free_skb(sk, skb); 1113 } 1114 1115 do_error: 1116 if (copied) 1117 goto out; 1118 out_err: 1119 err = sk_stream_error(sk, flags, err); 1120 TCP_CHECK_TIMER(sk); 1121 release_sock(sk); 1122 return err; 1123 } 1124 1125 /* 1126 * Handle reading urgent data. BSD has very simple semantics for 1127 * this, no blocking and very strange errors 8) 1128 */ 1129 1130 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) 1131 { 1132 struct tcp_sock *tp = tcp_sk(sk); 1133 1134 /* No URG data to read. */ 1135 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1136 tp->urg_data == TCP_URG_READ) 1137 return -EINVAL; /* Yes this is right ! */ 1138 1139 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1140 return -ENOTCONN; 1141 1142 if (tp->urg_data & TCP_URG_VALID) { 1143 int err = 0; 1144 char c = tp->urg_data; 1145 1146 if (!(flags & MSG_PEEK)) 1147 tp->urg_data = TCP_URG_READ; 1148 1149 /* Read urgent data. */ 1150 msg->msg_flags |= MSG_OOB; 1151 1152 if (len > 0) { 1153 if (!(flags & MSG_TRUNC)) 1154 err = memcpy_toiovec(msg->msg_iov, &c, 1); 1155 len = 1; 1156 } else 1157 msg->msg_flags |= MSG_TRUNC; 1158 1159 return err ? -EFAULT : len; 1160 } 1161 1162 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1163 return 0; 1164 1165 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1166 * the available implementations agree in this case: 1167 * this call should never block, independent of the 1168 * blocking state of the socket. 1169 * Mike <pall@rz.uni-karlsruhe.de> 1170 */ 1171 return -EAGAIN; 1172 } 1173 1174 /* Clean up the receive buffer for full frames taken by the user, 1175 * then send an ACK if necessary. COPIED is the number of bytes 1176 * tcp_recvmsg has given to the user so far, it speeds up the 1177 * calculation of whether or not we must ACK for the sake of 1178 * a window update. 1179 */ 1180 void tcp_cleanup_rbuf(struct sock *sk, int copied) 1181 { 1182 struct tcp_sock *tp = tcp_sk(sk); 1183 int time_to_ack = 0; 1184 1185 #if TCP_DEBUG 1186 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1187 1188 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), 1189 KERN_INFO "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", 1190 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); 1191 #endif 1192 1193 if (inet_csk_ack_scheduled(sk)) { 1194 const struct inet_connection_sock *icsk = inet_csk(sk); 1195 /* Delayed ACKs frequently hit locked sockets during bulk 1196 * receive. */ 1197 if (icsk->icsk_ack.blocked || 1198 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1199 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1200 /* 1201 * If this read emptied read buffer, we send ACK, if 1202 * connection is not bidirectional, user drained 1203 * receive buffer and there was a small segment 1204 * in queue. 1205 */ 1206 (copied > 0 && 1207 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1208 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1209 !icsk->icsk_ack.pingpong)) && 1210 !atomic_read(&sk->sk_rmem_alloc))) 1211 time_to_ack = 1; 1212 } 1213 1214 /* We send an ACK if we can now advertise a non-zero window 1215 * which has been raised "significantly". 1216 * 1217 * Even if window raised up to infinity, do not send window open ACK 1218 * in states, where we will not receive more. It is useless. 1219 */ 1220 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1221 __u32 rcv_window_now = tcp_receive_window(tp); 1222 1223 /* Optimize, __tcp_select_window() is not cheap. */ 1224 if (2*rcv_window_now <= tp->window_clamp) { 1225 __u32 new_window = __tcp_select_window(sk); 1226 1227 /* Send ACK now, if this read freed lots of space 1228 * in our buffer. Certainly, new_window is new window. 1229 * We can advertise it now, if it is not less than current one. 1230 * "Lots" means "at least twice" here. 1231 */ 1232 if (new_window && new_window >= 2 * rcv_window_now) 1233 time_to_ack = 1; 1234 } 1235 } 1236 if (time_to_ack) 1237 tcp_send_ack(sk); 1238 } 1239 1240 static void tcp_prequeue_process(struct sock *sk) 1241 { 1242 struct sk_buff *skb; 1243 struct tcp_sock *tp = tcp_sk(sk); 1244 1245 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); 1246 1247 /* RX process wants to run with disabled BHs, though it is not 1248 * necessary */ 1249 local_bh_disable(); 1250 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) 1251 sk_backlog_rcv(sk, skb); 1252 local_bh_enable(); 1253 1254 /* Clear memory counter. */ 1255 tp->ucopy.memory = 0; 1256 } 1257 1258 #ifdef CONFIG_NET_DMA 1259 static void tcp_service_net_dma(struct sock *sk, bool wait) 1260 { 1261 dma_cookie_t done, used; 1262 dma_cookie_t last_issued; 1263 struct tcp_sock *tp = tcp_sk(sk); 1264 1265 if (!tp->ucopy.dma_chan) 1266 return; 1267 1268 last_issued = tp->ucopy.dma_cookie; 1269 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1270 1271 do { 1272 if (dma_async_memcpy_complete(tp->ucopy.dma_chan, 1273 last_issued, &done, 1274 &used) == DMA_SUCCESS) { 1275 /* Safe to free early-copied skbs now */ 1276 __skb_queue_purge(&sk->sk_async_wait_queue); 1277 break; 1278 } else { 1279 struct sk_buff *skb; 1280 while ((skb = skb_peek(&sk->sk_async_wait_queue)) && 1281 (dma_async_is_complete(skb->dma_cookie, done, 1282 used) == DMA_SUCCESS)) { 1283 __skb_dequeue(&sk->sk_async_wait_queue); 1284 kfree_skb(skb); 1285 } 1286 } 1287 } while (wait); 1288 } 1289 #endif 1290 1291 static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1292 { 1293 struct sk_buff *skb; 1294 u32 offset; 1295 1296 skb_queue_walk(&sk->sk_receive_queue, skb) { 1297 offset = seq - TCP_SKB_CB(skb)->seq; 1298 if (tcp_hdr(skb)->syn) 1299 offset--; 1300 if (offset < skb->len || tcp_hdr(skb)->fin) { 1301 *off = offset; 1302 return skb; 1303 } 1304 } 1305 return NULL; 1306 } 1307 1308 /* 1309 * This routine provides an alternative to tcp_recvmsg() for routines 1310 * that would like to handle copying from skbuffs directly in 'sendfile' 1311 * fashion. 1312 * Note: 1313 * - It is assumed that the socket was locked by the caller. 1314 * - The routine does not block. 1315 * - At present, there is no support for reading OOB data 1316 * or for 'peeking' the socket using this routine 1317 * (although both would be easy to implement). 1318 */ 1319 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1320 sk_read_actor_t recv_actor) 1321 { 1322 struct sk_buff *skb; 1323 struct tcp_sock *tp = tcp_sk(sk); 1324 u32 seq = tp->copied_seq; 1325 u32 offset; 1326 int copied = 0; 1327 1328 if (sk->sk_state == TCP_LISTEN) 1329 return -ENOTCONN; 1330 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1331 if (offset < skb->len) { 1332 int used; 1333 size_t len; 1334 1335 len = skb->len - offset; 1336 /* Stop reading if we hit a patch of urgent data */ 1337 if (tp->urg_data) { 1338 u32 urg_offset = tp->urg_seq - seq; 1339 if (urg_offset < len) 1340 len = urg_offset; 1341 if (!len) 1342 break; 1343 } 1344 used = recv_actor(desc, skb, offset, len); 1345 if (used < 0) { 1346 if (!copied) 1347 copied = used; 1348 break; 1349 } else if (used <= len) { 1350 seq += used; 1351 copied += used; 1352 offset += used; 1353 } 1354 /* 1355 * If recv_actor drops the lock (e.g. TCP splice 1356 * receive) the skb pointer might be invalid when 1357 * getting here: tcp_collapse might have deleted it 1358 * while aggregating skbs from the socket queue. 1359 */ 1360 skb = tcp_recv_skb(sk, seq-1, &offset); 1361 if (!skb || (offset+1 != skb->len)) 1362 break; 1363 } 1364 if (tcp_hdr(skb)->fin) { 1365 sk_eat_skb(sk, skb, 0); 1366 ++seq; 1367 break; 1368 } 1369 sk_eat_skb(sk, skb, 0); 1370 if (!desc->count) 1371 break; 1372 tp->copied_seq = seq; 1373 } 1374 tp->copied_seq = seq; 1375 1376 tcp_rcv_space_adjust(sk); 1377 1378 /* Clean up data we have read: This will do ACK frames. */ 1379 if (copied > 0) 1380 tcp_cleanup_rbuf(sk, copied); 1381 return copied; 1382 } 1383 1384 /* 1385 * This routine copies from a sock struct into the user buffer. 1386 * 1387 * Technical note: in 2.3 we work on _locked_ socket, so that 1388 * tricks with *seq access order and skb->users are not required. 1389 * Probably, code can be easily improved even more. 1390 */ 1391 1392 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1393 size_t len, int nonblock, int flags, int *addr_len) 1394 { 1395 struct tcp_sock *tp = tcp_sk(sk); 1396 int copied = 0; 1397 u32 peek_seq; 1398 u32 *seq; 1399 unsigned long used; 1400 int err; 1401 int target; /* Read at least this many bytes */ 1402 long timeo; 1403 struct task_struct *user_recv = NULL; 1404 int copied_early = 0; 1405 struct sk_buff *skb; 1406 u32 urg_hole = 0; 1407 1408 lock_sock(sk); 1409 1410 TCP_CHECK_TIMER(sk); 1411 1412 err = -ENOTCONN; 1413 if (sk->sk_state == TCP_LISTEN) 1414 goto out; 1415 1416 timeo = sock_rcvtimeo(sk, nonblock); 1417 1418 /* Urgent data needs to be handled specially. */ 1419 if (flags & MSG_OOB) 1420 goto recv_urg; 1421 1422 seq = &tp->copied_seq; 1423 if (flags & MSG_PEEK) { 1424 peek_seq = tp->copied_seq; 1425 seq = &peek_seq; 1426 } 1427 1428 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1429 1430 #ifdef CONFIG_NET_DMA 1431 tp->ucopy.dma_chan = NULL; 1432 preempt_disable(); 1433 skb = skb_peek_tail(&sk->sk_receive_queue); 1434 { 1435 int available = 0; 1436 1437 if (skb) 1438 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); 1439 if ((available < target) && 1440 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && 1441 !sysctl_tcp_low_latency && 1442 dma_find_channel(DMA_MEMCPY)) { 1443 preempt_enable_no_resched(); 1444 tp->ucopy.pinned_list = 1445 dma_pin_iovec_pages(msg->msg_iov, len); 1446 } else { 1447 preempt_enable_no_resched(); 1448 } 1449 } 1450 #endif 1451 1452 do { 1453 u32 offset; 1454 1455 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1456 if (tp->urg_data && tp->urg_seq == *seq) { 1457 if (copied) 1458 break; 1459 if (signal_pending(current)) { 1460 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1461 break; 1462 } 1463 } 1464 1465 /* Next get a buffer. */ 1466 1467 skb_queue_walk(&sk->sk_receive_queue, skb) { 1468 /* Now that we have two receive queues this 1469 * shouldn't happen. 1470 */ 1471 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 1472 KERN_INFO "recvmsg bug: copied %X " 1473 "seq %X rcvnxt %X fl %X\n", *seq, 1474 TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 1475 flags)) 1476 break; 1477 1478 offset = *seq - TCP_SKB_CB(skb)->seq; 1479 if (tcp_hdr(skb)->syn) 1480 offset--; 1481 if (offset < skb->len) 1482 goto found_ok_skb; 1483 if (tcp_hdr(skb)->fin) 1484 goto found_fin_ok; 1485 WARN(!(flags & MSG_PEEK), KERN_INFO "recvmsg bug 2: " 1486 "copied %X seq %X rcvnxt %X fl %X\n", 1487 *seq, TCP_SKB_CB(skb)->seq, 1488 tp->rcv_nxt, flags); 1489 } 1490 1491 /* Well, if we have backlog, try to process it now yet. */ 1492 1493 if (copied >= target && !sk->sk_backlog.tail) 1494 break; 1495 1496 if (copied) { 1497 if (sk->sk_err || 1498 sk->sk_state == TCP_CLOSE || 1499 (sk->sk_shutdown & RCV_SHUTDOWN) || 1500 !timeo || 1501 signal_pending(current)) 1502 break; 1503 } else { 1504 if (sock_flag(sk, SOCK_DONE)) 1505 break; 1506 1507 if (sk->sk_err) { 1508 copied = sock_error(sk); 1509 break; 1510 } 1511 1512 if (sk->sk_shutdown & RCV_SHUTDOWN) 1513 break; 1514 1515 if (sk->sk_state == TCP_CLOSE) { 1516 if (!sock_flag(sk, SOCK_DONE)) { 1517 /* This occurs when user tries to read 1518 * from never connected socket. 1519 */ 1520 copied = -ENOTCONN; 1521 break; 1522 } 1523 break; 1524 } 1525 1526 if (!timeo) { 1527 copied = -EAGAIN; 1528 break; 1529 } 1530 1531 if (signal_pending(current)) { 1532 copied = sock_intr_errno(timeo); 1533 break; 1534 } 1535 } 1536 1537 tcp_cleanup_rbuf(sk, copied); 1538 1539 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { 1540 /* Install new reader */ 1541 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { 1542 user_recv = current; 1543 tp->ucopy.task = user_recv; 1544 tp->ucopy.iov = msg->msg_iov; 1545 } 1546 1547 tp->ucopy.len = len; 1548 1549 WARN_ON(tp->copied_seq != tp->rcv_nxt && 1550 !(flags & (MSG_PEEK | MSG_TRUNC))); 1551 1552 /* Ugly... If prequeue is not empty, we have to 1553 * process it before releasing socket, otherwise 1554 * order will be broken at second iteration. 1555 * More elegant solution is required!!! 1556 * 1557 * Look: we have the following (pseudo)queues: 1558 * 1559 * 1. packets in flight 1560 * 2. backlog 1561 * 3. prequeue 1562 * 4. receive_queue 1563 * 1564 * Each queue can be processed only if the next ones 1565 * are empty. At this point we have empty receive_queue. 1566 * But prequeue _can_ be not empty after 2nd iteration, 1567 * when we jumped to start of loop because backlog 1568 * processing added something to receive_queue. 1569 * We cannot release_sock(), because backlog contains 1570 * packets arrived _after_ prequeued ones. 1571 * 1572 * Shortly, algorithm is clear --- to process all 1573 * the queues in order. We could make it more directly, 1574 * requeueing packets from backlog to prequeue, if 1575 * is not empty. It is more elegant, but eats cycles, 1576 * unfortunately. 1577 */ 1578 if (!skb_queue_empty(&tp->ucopy.prequeue)) 1579 goto do_prequeue; 1580 1581 /* __ Set realtime policy in scheduler __ */ 1582 } 1583 1584 #ifdef CONFIG_NET_DMA 1585 if (tp->ucopy.dma_chan) 1586 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1587 #endif 1588 if (copied >= target) { 1589 /* Do not sleep, just process backlog. */ 1590 release_sock(sk); 1591 lock_sock(sk); 1592 } else 1593 sk_wait_data(sk, &timeo); 1594 1595 #ifdef CONFIG_NET_DMA 1596 tcp_service_net_dma(sk, false); /* Don't block */ 1597 tp->ucopy.wakeup = 0; 1598 #endif 1599 1600 if (user_recv) { 1601 int chunk; 1602 1603 /* __ Restore normal policy in scheduler __ */ 1604 1605 if ((chunk = len - tp->ucopy.len) != 0) { 1606 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); 1607 len -= chunk; 1608 copied += chunk; 1609 } 1610 1611 if (tp->rcv_nxt == tp->copied_seq && 1612 !skb_queue_empty(&tp->ucopy.prequeue)) { 1613 do_prequeue: 1614 tcp_prequeue_process(sk); 1615 1616 if ((chunk = len - tp->ucopy.len) != 0) { 1617 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1618 len -= chunk; 1619 copied += chunk; 1620 } 1621 } 1622 } 1623 if ((flags & MSG_PEEK) && 1624 (peek_seq - copied - urg_hole != tp->copied_seq)) { 1625 if (net_ratelimit()) 1626 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n", 1627 current->comm, task_pid_nr(current)); 1628 peek_seq = tp->copied_seq; 1629 } 1630 continue; 1631 1632 found_ok_skb: 1633 /* Ok so how much can we use? */ 1634 used = skb->len - offset; 1635 if (len < used) 1636 used = len; 1637 1638 /* Do we have urgent data here? */ 1639 if (tp->urg_data) { 1640 u32 urg_offset = tp->urg_seq - *seq; 1641 if (urg_offset < used) { 1642 if (!urg_offset) { 1643 if (!sock_flag(sk, SOCK_URGINLINE)) { 1644 ++*seq; 1645 urg_hole++; 1646 offset++; 1647 used--; 1648 if (!used) 1649 goto skip_copy; 1650 } 1651 } else 1652 used = urg_offset; 1653 } 1654 } 1655 1656 if (!(flags & MSG_TRUNC)) { 1657 #ifdef CONFIG_NET_DMA 1658 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1659 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); 1660 1661 if (tp->ucopy.dma_chan) { 1662 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( 1663 tp->ucopy.dma_chan, skb, offset, 1664 msg->msg_iov, used, 1665 tp->ucopy.pinned_list); 1666 1667 if (tp->ucopy.dma_cookie < 0) { 1668 1669 printk(KERN_ALERT "dma_cookie < 0\n"); 1670 1671 /* Exception. Bailout! */ 1672 if (!copied) 1673 copied = -EFAULT; 1674 break; 1675 } 1676 1677 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1678 1679 if ((offset + used) == skb->len) 1680 copied_early = 1; 1681 1682 } else 1683 #endif 1684 { 1685 err = skb_copy_datagram_iovec(skb, offset, 1686 msg->msg_iov, used); 1687 if (err) { 1688 /* Exception. Bailout! */ 1689 if (!copied) 1690 copied = -EFAULT; 1691 break; 1692 } 1693 } 1694 } 1695 1696 *seq += used; 1697 copied += used; 1698 len -= used; 1699 1700 tcp_rcv_space_adjust(sk); 1701 1702 skip_copy: 1703 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1704 tp->urg_data = 0; 1705 tcp_fast_path_check(sk); 1706 } 1707 if (used + offset < skb->len) 1708 continue; 1709 1710 if (tcp_hdr(skb)->fin) 1711 goto found_fin_ok; 1712 if (!(flags & MSG_PEEK)) { 1713 sk_eat_skb(sk, skb, copied_early); 1714 copied_early = 0; 1715 } 1716 continue; 1717 1718 found_fin_ok: 1719 /* Process the FIN. */ 1720 ++*seq; 1721 if (!(flags & MSG_PEEK)) { 1722 sk_eat_skb(sk, skb, copied_early); 1723 copied_early = 0; 1724 } 1725 break; 1726 } while (len > 0); 1727 1728 if (user_recv) { 1729 if (!skb_queue_empty(&tp->ucopy.prequeue)) { 1730 int chunk; 1731 1732 tp->ucopy.len = copied > 0 ? len : 0; 1733 1734 tcp_prequeue_process(sk); 1735 1736 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { 1737 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1738 len -= chunk; 1739 copied += chunk; 1740 } 1741 } 1742 1743 tp->ucopy.task = NULL; 1744 tp->ucopy.len = 0; 1745 } 1746 1747 #ifdef CONFIG_NET_DMA 1748 tcp_service_net_dma(sk, true); /* Wait for queue to drain */ 1749 tp->ucopy.dma_chan = NULL; 1750 1751 if (tp->ucopy.pinned_list) { 1752 dma_unpin_iovec_pages(tp->ucopy.pinned_list); 1753 tp->ucopy.pinned_list = NULL; 1754 } 1755 #endif 1756 1757 /* According to UNIX98, msg_name/msg_namelen are ignored 1758 * on connected socket. I was just happy when found this 8) --ANK 1759 */ 1760 1761 /* Clean up data we have read: This will do ACK frames. */ 1762 tcp_cleanup_rbuf(sk, copied); 1763 1764 TCP_CHECK_TIMER(sk); 1765 release_sock(sk); 1766 return copied; 1767 1768 out: 1769 TCP_CHECK_TIMER(sk); 1770 release_sock(sk); 1771 return err; 1772 1773 recv_urg: 1774 err = tcp_recv_urg(sk, msg, len, flags); 1775 goto out; 1776 } 1777 1778 void tcp_set_state(struct sock *sk, int state) 1779 { 1780 int oldstate = sk->sk_state; 1781 1782 switch (state) { 1783 case TCP_ESTABLISHED: 1784 if (oldstate != TCP_ESTABLISHED) 1785 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1786 break; 1787 1788 case TCP_CLOSE: 1789 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 1790 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 1791 1792 sk->sk_prot->unhash(sk); 1793 if (inet_csk(sk)->icsk_bind_hash && 1794 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1795 inet_put_port(sk); 1796 /* fall through */ 1797 default: 1798 if (oldstate == TCP_ESTABLISHED) 1799 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1800 } 1801 1802 /* Change state AFTER socket is unhashed to avoid closed 1803 * socket sitting in hash tables. 1804 */ 1805 sk->sk_state = state; 1806 1807 #ifdef STATE_TRACE 1808 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); 1809 #endif 1810 } 1811 EXPORT_SYMBOL_GPL(tcp_set_state); 1812 1813 /* 1814 * State processing on a close. This implements the state shift for 1815 * sending our FIN frame. Note that we only send a FIN for some 1816 * states. A shutdown() may have already sent the FIN, or we may be 1817 * closed. 1818 */ 1819 1820 static const unsigned char new_state[16] = { 1821 /* current state: new state: action: */ 1822 /* (Invalid) */ TCP_CLOSE, 1823 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1824 /* TCP_SYN_SENT */ TCP_CLOSE, 1825 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1826 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, 1827 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, 1828 /* TCP_TIME_WAIT */ TCP_CLOSE, 1829 /* TCP_CLOSE */ TCP_CLOSE, 1830 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, 1831 /* TCP_LAST_ACK */ TCP_LAST_ACK, 1832 /* TCP_LISTEN */ TCP_CLOSE, 1833 /* TCP_CLOSING */ TCP_CLOSING, 1834 }; 1835 1836 static int tcp_close_state(struct sock *sk) 1837 { 1838 int next = (int)new_state[sk->sk_state]; 1839 int ns = next & TCP_STATE_MASK; 1840 1841 tcp_set_state(sk, ns); 1842 1843 return next & TCP_ACTION_FIN; 1844 } 1845 1846 /* 1847 * Shutdown the sending side of a connection. Much like close except 1848 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 1849 */ 1850 1851 void tcp_shutdown(struct sock *sk, int how) 1852 { 1853 /* We need to grab some memory, and put together a FIN, 1854 * and then put it into the queue to be sent. 1855 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 1856 */ 1857 if (!(how & SEND_SHUTDOWN)) 1858 return; 1859 1860 /* If we've already sent a FIN, or it's a closed state, skip this. */ 1861 if ((1 << sk->sk_state) & 1862 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 1863 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 1864 /* Clear out any half completed packets. FIN if needed. */ 1865 if (tcp_close_state(sk)) 1866 tcp_send_fin(sk); 1867 } 1868 } 1869 1870 void tcp_close(struct sock *sk, long timeout) 1871 { 1872 struct sk_buff *skb; 1873 int data_was_unread = 0; 1874 int state; 1875 1876 lock_sock(sk); 1877 sk->sk_shutdown = SHUTDOWN_MASK; 1878 1879 if (sk->sk_state == TCP_LISTEN) { 1880 tcp_set_state(sk, TCP_CLOSE); 1881 1882 /* Special case. */ 1883 inet_csk_listen_stop(sk); 1884 1885 goto adjudge_to_death; 1886 } 1887 1888 /* We need to flush the recv. buffs. We do this only on the 1889 * descriptor close, not protocol-sourced closes, because the 1890 * reader process may not have drained the data yet! 1891 */ 1892 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1893 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - 1894 tcp_hdr(skb)->fin; 1895 data_was_unread += len; 1896 __kfree_skb(skb); 1897 } 1898 1899 sk_mem_reclaim(sk); 1900 1901 /* As outlined in RFC 2525, section 2.17, we send a RST here because 1902 * data was lost. To witness the awful effects of the old behavior of 1903 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 1904 * GET in an FTP client, suspend the process, wait for the client to 1905 * advertise a zero window, then kill -9 the FTP client, wheee... 1906 * Note: timeout is always zero in such a case. 1907 */ 1908 if (data_was_unread) { 1909 /* Unread data was tossed, zap the connection. */ 1910 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 1911 tcp_set_state(sk, TCP_CLOSE); 1912 tcp_send_active_reset(sk, sk->sk_allocation); 1913 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1914 /* Check zero linger _after_ checking for unread data. */ 1915 sk->sk_prot->disconnect(sk, 0); 1916 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 1917 } else if (tcp_close_state(sk)) { 1918 /* We FIN if the application ate all the data before 1919 * zapping the connection. 1920 */ 1921 1922 /* RED-PEN. Formally speaking, we have broken TCP state 1923 * machine. State transitions: 1924 * 1925 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 1926 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 1927 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 1928 * 1929 * are legal only when FIN has been sent (i.e. in window), 1930 * rather than queued out of window. Purists blame. 1931 * 1932 * F.e. "RFC state" is ESTABLISHED, 1933 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 1934 * 1935 * The visible declinations are that sometimes 1936 * we enter time-wait state, when it is not required really 1937 * (harmless), do not send active resets, when they are 1938 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 1939 * they look as CLOSING or LAST_ACK for Linux) 1940 * Probably, I missed some more holelets. 1941 * --ANK 1942 */ 1943 tcp_send_fin(sk); 1944 } 1945 1946 sk_stream_wait_close(sk, timeout); 1947 1948 adjudge_to_death: 1949 state = sk->sk_state; 1950 sock_hold(sk); 1951 sock_orphan(sk); 1952 1953 /* It is the last release_sock in its life. It will remove backlog. */ 1954 release_sock(sk); 1955 1956 1957 /* Now socket is owned by kernel and we acquire BH lock 1958 to finish close. No need to check for user refs. 1959 */ 1960 local_bh_disable(); 1961 bh_lock_sock(sk); 1962 WARN_ON(sock_owned_by_user(sk)); 1963 1964 percpu_counter_inc(sk->sk_prot->orphan_count); 1965 1966 /* Have we already been destroyed by a softirq or backlog? */ 1967 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 1968 goto out; 1969 1970 /* This is a (useful) BSD violating of the RFC. There is a 1971 * problem with TCP as specified in that the other end could 1972 * keep a socket open forever with no application left this end. 1973 * We use a 3 minute timeout (about the same as BSD) then kill 1974 * our end. If they send after that then tough - BUT: long enough 1975 * that we won't make the old 4*rto = almost no time - whoops 1976 * reset mistake. 1977 * 1978 * Nope, it was not mistake. It is really desired behaviour 1979 * f.e. on http servers, when such sockets are useless, but 1980 * consume significant resources. Let's do it with special 1981 * linger2 option. --ANK 1982 */ 1983 1984 if (sk->sk_state == TCP_FIN_WAIT2) { 1985 struct tcp_sock *tp = tcp_sk(sk); 1986 if (tp->linger2 < 0) { 1987 tcp_set_state(sk, TCP_CLOSE); 1988 tcp_send_active_reset(sk, GFP_ATOMIC); 1989 NET_INC_STATS_BH(sock_net(sk), 1990 LINUX_MIB_TCPABORTONLINGER); 1991 } else { 1992 const int tmo = tcp_fin_time(sk); 1993 1994 if (tmo > TCP_TIMEWAIT_LEN) { 1995 inet_csk_reset_keepalive_timer(sk, 1996 tmo - TCP_TIMEWAIT_LEN); 1997 } else { 1998 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 1999 goto out; 2000 } 2001 } 2002 } 2003 if (sk->sk_state != TCP_CLOSE) { 2004 int orphan_count = percpu_counter_read_positive( 2005 sk->sk_prot->orphan_count); 2006 2007 sk_mem_reclaim(sk); 2008 if (tcp_too_many_orphans(sk, orphan_count)) { 2009 if (net_ratelimit()) 2010 printk(KERN_INFO "TCP: too many of orphaned " 2011 "sockets\n"); 2012 tcp_set_state(sk, TCP_CLOSE); 2013 tcp_send_active_reset(sk, GFP_ATOMIC); 2014 NET_INC_STATS_BH(sock_net(sk), 2015 LINUX_MIB_TCPABORTONMEMORY); 2016 } 2017 } 2018 2019 if (sk->sk_state == TCP_CLOSE) 2020 inet_csk_destroy_sock(sk); 2021 /* Otherwise, socket is reprieved until protocol close. */ 2022 2023 out: 2024 bh_unlock_sock(sk); 2025 local_bh_enable(); 2026 sock_put(sk); 2027 } 2028 2029 /* These states need RST on ABORT according to RFC793 */ 2030 2031 static inline int tcp_need_reset(int state) 2032 { 2033 return (1 << state) & 2034 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2035 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2036 } 2037 2038 int tcp_disconnect(struct sock *sk, int flags) 2039 { 2040 struct inet_sock *inet = inet_sk(sk); 2041 struct inet_connection_sock *icsk = inet_csk(sk); 2042 struct tcp_sock *tp = tcp_sk(sk); 2043 int err = 0; 2044 int old_state = sk->sk_state; 2045 2046 if (old_state != TCP_CLOSE) 2047 tcp_set_state(sk, TCP_CLOSE); 2048 2049 /* ABORT function of RFC793 */ 2050 if (old_state == TCP_LISTEN) { 2051 inet_csk_listen_stop(sk); 2052 } else if (tcp_need_reset(old_state) || 2053 (tp->snd_nxt != tp->write_seq && 2054 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2055 /* The last check adjusts for discrepancy of Linux wrt. RFC 2056 * states 2057 */ 2058 tcp_send_active_reset(sk, gfp_any()); 2059 sk->sk_err = ECONNRESET; 2060 } else if (old_state == TCP_SYN_SENT) 2061 sk->sk_err = ECONNRESET; 2062 2063 tcp_clear_xmit_timers(sk); 2064 __skb_queue_purge(&sk->sk_receive_queue); 2065 tcp_write_queue_purge(sk); 2066 __skb_queue_purge(&tp->out_of_order_queue); 2067 #ifdef CONFIG_NET_DMA 2068 __skb_queue_purge(&sk->sk_async_wait_queue); 2069 #endif 2070 2071 inet->inet_dport = 0; 2072 2073 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2074 inet_reset_saddr(sk); 2075 2076 sk->sk_shutdown = 0; 2077 sock_reset_flag(sk, SOCK_DONE); 2078 tp->srtt = 0; 2079 if ((tp->write_seq += tp->max_window + 2) == 0) 2080 tp->write_seq = 1; 2081 icsk->icsk_backoff = 0; 2082 tp->snd_cwnd = 2; 2083 icsk->icsk_probes_out = 0; 2084 tp->packets_out = 0; 2085 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2086 tp->snd_cwnd_cnt = 0; 2087 tp->bytes_acked = 0; 2088 tp->window_clamp = 0; 2089 tcp_set_ca_state(sk, TCP_CA_Open); 2090 tcp_clear_retrans(tp); 2091 inet_csk_delack_init(sk); 2092 tcp_init_send_head(sk); 2093 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2094 __sk_dst_reset(sk); 2095 2096 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2097 2098 sk->sk_error_report(sk); 2099 return err; 2100 } 2101 2102 /* 2103 * Socket option code for TCP. 2104 */ 2105 static int do_tcp_setsockopt(struct sock *sk, int level, 2106 int optname, char __user *optval, unsigned int optlen) 2107 { 2108 struct tcp_sock *tp = tcp_sk(sk); 2109 struct inet_connection_sock *icsk = inet_csk(sk); 2110 int val; 2111 int err = 0; 2112 2113 /* These are data/string values, all the others are ints */ 2114 switch (optname) { 2115 case TCP_CONGESTION: { 2116 char name[TCP_CA_NAME_MAX]; 2117 2118 if (optlen < 1) 2119 return -EINVAL; 2120 2121 val = strncpy_from_user(name, optval, 2122 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2123 if (val < 0) 2124 return -EFAULT; 2125 name[val] = 0; 2126 2127 lock_sock(sk); 2128 err = tcp_set_congestion_control(sk, name); 2129 release_sock(sk); 2130 return err; 2131 } 2132 case TCP_COOKIE_TRANSACTIONS: { 2133 struct tcp_cookie_transactions ctd; 2134 struct tcp_cookie_values *cvp = NULL; 2135 2136 if (sizeof(ctd) > optlen) 2137 return -EINVAL; 2138 if (copy_from_user(&ctd, optval, sizeof(ctd))) 2139 return -EFAULT; 2140 2141 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) || 2142 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED) 2143 return -EINVAL; 2144 2145 if (ctd.tcpct_cookie_desired == 0) { 2146 /* default to global value */ 2147 } else if ((0x1 & ctd.tcpct_cookie_desired) || 2148 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX || 2149 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) { 2150 return -EINVAL; 2151 } 2152 2153 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) { 2154 /* Supercedes all other values */ 2155 lock_sock(sk); 2156 if (tp->cookie_values != NULL) { 2157 kref_put(&tp->cookie_values->kref, 2158 tcp_cookie_values_release); 2159 tp->cookie_values = NULL; 2160 } 2161 tp->rx_opt.cookie_in_always = 0; /* false */ 2162 tp->rx_opt.cookie_out_never = 1; /* true */ 2163 release_sock(sk); 2164 return err; 2165 } 2166 2167 /* Allocate ancillary memory before locking. 2168 */ 2169 if (ctd.tcpct_used > 0 || 2170 (tp->cookie_values == NULL && 2171 (sysctl_tcp_cookie_size > 0 || 2172 ctd.tcpct_cookie_desired > 0 || 2173 ctd.tcpct_s_data_desired > 0))) { 2174 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used, 2175 GFP_KERNEL); 2176 if (cvp == NULL) 2177 return -ENOMEM; 2178 } 2179 lock_sock(sk); 2180 tp->rx_opt.cookie_in_always = 2181 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags); 2182 tp->rx_opt.cookie_out_never = 0; /* false */ 2183 2184 if (tp->cookie_values != NULL) { 2185 if (cvp != NULL) { 2186 /* Changed values are recorded by a changed 2187 * pointer, ensuring the cookie will differ, 2188 * without separately hashing each value later. 2189 */ 2190 kref_put(&tp->cookie_values->kref, 2191 tcp_cookie_values_release); 2192 kref_init(&cvp->kref); 2193 tp->cookie_values = cvp; 2194 } else { 2195 cvp = tp->cookie_values; 2196 } 2197 } 2198 if (cvp != NULL) { 2199 cvp->cookie_desired = ctd.tcpct_cookie_desired; 2200 2201 if (ctd.tcpct_used > 0) { 2202 memcpy(cvp->s_data_payload, ctd.tcpct_value, 2203 ctd.tcpct_used); 2204 cvp->s_data_desired = ctd.tcpct_used; 2205 cvp->s_data_constant = 1; /* true */ 2206 } else { 2207 /* No constant payload data. */ 2208 cvp->s_data_desired = ctd.tcpct_s_data_desired; 2209 cvp->s_data_constant = 0; /* false */ 2210 } 2211 } 2212 release_sock(sk); 2213 return err; 2214 } 2215 default: 2216 /* fallthru */ 2217 break; 2218 } 2219 2220 if (optlen < sizeof(int)) 2221 return -EINVAL; 2222 2223 if (get_user(val, (int __user *)optval)) 2224 return -EFAULT; 2225 2226 lock_sock(sk); 2227 2228 switch (optname) { 2229 case TCP_MAXSEG: 2230 /* Values greater than interface MTU won't take effect. However 2231 * at the point when this call is done we typically don't yet 2232 * know which interface is going to be used */ 2233 if (val < 8 || val > MAX_TCP_WINDOW) { 2234 err = -EINVAL; 2235 break; 2236 } 2237 tp->rx_opt.user_mss = val; 2238 break; 2239 2240 case TCP_NODELAY: 2241 if (val) { 2242 /* TCP_NODELAY is weaker than TCP_CORK, so that 2243 * this option on corked socket is remembered, but 2244 * it is not activated until cork is cleared. 2245 * 2246 * However, when TCP_NODELAY is set we make 2247 * an explicit push, which overrides even TCP_CORK 2248 * for currently queued segments. 2249 */ 2250 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2251 tcp_push_pending_frames(sk); 2252 } else { 2253 tp->nonagle &= ~TCP_NAGLE_OFF; 2254 } 2255 break; 2256 2257 case TCP_THIN_LINEAR_TIMEOUTS: 2258 if (val < 0 || val > 1) 2259 err = -EINVAL; 2260 else 2261 tp->thin_lto = val; 2262 break; 2263 2264 case TCP_THIN_DUPACK: 2265 if (val < 0 || val > 1) 2266 err = -EINVAL; 2267 else 2268 tp->thin_dupack = val; 2269 break; 2270 2271 case TCP_CORK: 2272 /* When set indicates to always queue non-full frames. 2273 * Later the user clears this option and we transmit 2274 * any pending partial frames in the queue. This is 2275 * meant to be used alongside sendfile() to get properly 2276 * filled frames when the user (for example) must write 2277 * out headers with a write() call first and then use 2278 * sendfile to send out the data parts. 2279 * 2280 * TCP_CORK can be set together with TCP_NODELAY and it is 2281 * stronger than TCP_NODELAY. 2282 */ 2283 if (val) { 2284 tp->nonagle |= TCP_NAGLE_CORK; 2285 } else { 2286 tp->nonagle &= ~TCP_NAGLE_CORK; 2287 if (tp->nonagle&TCP_NAGLE_OFF) 2288 tp->nonagle |= TCP_NAGLE_PUSH; 2289 tcp_push_pending_frames(sk); 2290 } 2291 break; 2292 2293 case TCP_KEEPIDLE: 2294 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2295 err = -EINVAL; 2296 else { 2297 tp->keepalive_time = val * HZ; 2298 if (sock_flag(sk, SOCK_KEEPOPEN) && 2299 !((1 << sk->sk_state) & 2300 (TCPF_CLOSE | TCPF_LISTEN))) { 2301 u32 elapsed = keepalive_time_elapsed(tp); 2302 if (tp->keepalive_time > elapsed) 2303 elapsed = tp->keepalive_time - elapsed; 2304 else 2305 elapsed = 0; 2306 inet_csk_reset_keepalive_timer(sk, elapsed); 2307 } 2308 } 2309 break; 2310 case TCP_KEEPINTVL: 2311 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2312 err = -EINVAL; 2313 else 2314 tp->keepalive_intvl = val * HZ; 2315 break; 2316 case TCP_KEEPCNT: 2317 if (val < 1 || val > MAX_TCP_KEEPCNT) 2318 err = -EINVAL; 2319 else 2320 tp->keepalive_probes = val; 2321 break; 2322 case TCP_SYNCNT: 2323 if (val < 1 || val > MAX_TCP_SYNCNT) 2324 err = -EINVAL; 2325 else 2326 icsk->icsk_syn_retries = val; 2327 break; 2328 2329 case TCP_LINGER2: 2330 if (val < 0) 2331 tp->linger2 = -1; 2332 else if (val > sysctl_tcp_fin_timeout / HZ) 2333 tp->linger2 = 0; 2334 else 2335 tp->linger2 = val * HZ; 2336 break; 2337 2338 case TCP_DEFER_ACCEPT: 2339 /* Translate value in seconds to number of retransmits */ 2340 icsk->icsk_accept_queue.rskq_defer_accept = 2341 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2342 TCP_RTO_MAX / HZ); 2343 break; 2344 2345 case TCP_WINDOW_CLAMP: 2346 if (!val) { 2347 if (sk->sk_state != TCP_CLOSE) { 2348 err = -EINVAL; 2349 break; 2350 } 2351 tp->window_clamp = 0; 2352 } else 2353 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2354 SOCK_MIN_RCVBUF / 2 : val; 2355 break; 2356 2357 case TCP_QUICKACK: 2358 if (!val) { 2359 icsk->icsk_ack.pingpong = 1; 2360 } else { 2361 icsk->icsk_ack.pingpong = 0; 2362 if ((1 << sk->sk_state) & 2363 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2364 inet_csk_ack_scheduled(sk)) { 2365 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2366 tcp_cleanup_rbuf(sk, 1); 2367 if (!(val & 1)) 2368 icsk->icsk_ack.pingpong = 1; 2369 } 2370 } 2371 break; 2372 2373 #ifdef CONFIG_TCP_MD5SIG 2374 case TCP_MD5SIG: 2375 /* Read the IP->Key mappings from userspace */ 2376 err = tp->af_specific->md5_parse(sk, optval, optlen); 2377 break; 2378 #endif 2379 2380 default: 2381 err = -ENOPROTOOPT; 2382 break; 2383 } 2384 2385 release_sock(sk); 2386 return err; 2387 } 2388 2389 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2390 unsigned int optlen) 2391 { 2392 struct inet_connection_sock *icsk = inet_csk(sk); 2393 2394 if (level != SOL_TCP) 2395 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2396 optval, optlen); 2397 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2398 } 2399 2400 #ifdef CONFIG_COMPAT 2401 int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2402 char __user *optval, unsigned int optlen) 2403 { 2404 if (level != SOL_TCP) 2405 return inet_csk_compat_setsockopt(sk, level, optname, 2406 optval, optlen); 2407 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2408 } 2409 2410 EXPORT_SYMBOL(compat_tcp_setsockopt); 2411 #endif 2412 2413 /* Return information about state of tcp endpoint in API format. */ 2414 void tcp_get_info(struct sock *sk, struct tcp_info *info) 2415 { 2416 struct tcp_sock *tp = tcp_sk(sk); 2417 const struct inet_connection_sock *icsk = inet_csk(sk); 2418 u32 now = tcp_time_stamp; 2419 2420 memset(info, 0, sizeof(*info)); 2421 2422 info->tcpi_state = sk->sk_state; 2423 info->tcpi_ca_state = icsk->icsk_ca_state; 2424 info->tcpi_retransmits = icsk->icsk_retransmits; 2425 info->tcpi_probes = icsk->icsk_probes_out; 2426 info->tcpi_backoff = icsk->icsk_backoff; 2427 2428 if (tp->rx_opt.tstamp_ok) 2429 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2430 if (tcp_is_sack(tp)) 2431 info->tcpi_options |= TCPI_OPT_SACK; 2432 if (tp->rx_opt.wscale_ok) { 2433 info->tcpi_options |= TCPI_OPT_WSCALE; 2434 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2435 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2436 } 2437 2438 if (tp->ecn_flags&TCP_ECN_OK) 2439 info->tcpi_options |= TCPI_OPT_ECN; 2440 2441 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2442 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2443 info->tcpi_snd_mss = tp->mss_cache; 2444 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2445 2446 if (sk->sk_state == TCP_LISTEN) { 2447 info->tcpi_unacked = sk->sk_ack_backlog; 2448 info->tcpi_sacked = sk->sk_max_ack_backlog; 2449 } else { 2450 info->tcpi_unacked = tp->packets_out; 2451 info->tcpi_sacked = tp->sacked_out; 2452 } 2453 info->tcpi_lost = tp->lost_out; 2454 info->tcpi_retrans = tp->retrans_out; 2455 info->tcpi_fackets = tp->fackets_out; 2456 2457 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2458 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2459 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2460 2461 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2462 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2463 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3; 2464 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2; 2465 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2466 info->tcpi_snd_cwnd = tp->snd_cwnd; 2467 info->tcpi_advmss = tp->advmss; 2468 info->tcpi_reordering = tp->reordering; 2469 2470 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; 2471 info->tcpi_rcv_space = tp->rcvq_space.space; 2472 2473 info->tcpi_total_retrans = tp->total_retrans; 2474 } 2475 2476 EXPORT_SYMBOL_GPL(tcp_get_info); 2477 2478 static int do_tcp_getsockopt(struct sock *sk, int level, 2479 int optname, char __user *optval, int __user *optlen) 2480 { 2481 struct inet_connection_sock *icsk = inet_csk(sk); 2482 struct tcp_sock *tp = tcp_sk(sk); 2483 int val, len; 2484 2485 if (get_user(len, optlen)) 2486 return -EFAULT; 2487 2488 len = min_t(unsigned int, len, sizeof(int)); 2489 2490 if (len < 0) 2491 return -EINVAL; 2492 2493 switch (optname) { 2494 case TCP_MAXSEG: 2495 val = tp->mss_cache; 2496 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2497 val = tp->rx_opt.user_mss; 2498 break; 2499 case TCP_NODELAY: 2500 val = !!(tp->nonagle&TCP_NAGLE_OFF); 2501 break; 2502 case TCP_CORK: 2503 val = !!(tp->nonagle&TCP_NAGLE_CORK); 2504 break; 2505 case TCP_KEEPIDLE: 2506 val = keepalive_time_when(tp) / HZ; 2507 break; 2508 case TCP_KEEPINTVL: 2509 val = keepalive_intvl_when(tp) / HZ; 2510 break; 2511 case TCP_KEEPCNT: 2512 val = keepalive_probes(tp); 2513 break; 2514 case TCP_SYNCNT: 2515 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 2516 break; 2517 case TCP_LINGER2: 2518 val = tp->linger2; 2519 if (val >= 0) 2520 val = (val ? : sysctl_tcp_fin_timeout) / HZ; 2521 break; 2522 case TCP_DEFER_ACCEPT: 2523 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 2524 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 2525 break; 2526 case TCP_WINDOW_CLAMP: 2527 val = tp->window_clamp; 2528 break; 2529 case TCP_INFO: { 2530 struct tcp_info info; 2531 2532 if (get_user(len, optlen)) 2533 return -EFAULT; 2534 2535 tcp_get_info(sk, &info); 2536 2537 len = min_t(unsigned int, len, sizeof(info)); 2538 if (put_user(len, optlen)) 2539 return -EFAULT; 2540 if (copy_to_user(optval, &info, len)) 2541 return -EFAULT; 2542 return 0; 2543 } 2544 case TCP_QUICKACK: 2545 val = !icsk->icsk_ack.pingpong; 2546 break; 2547 2548 case TCP_CONGESTION: 2549 if (get_user(len, optlen)) 2550 return -EFAULT; 2551 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 2552 if (put_user(len, optlen)) 2553 return -EFAULT; 2554 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 2555 return -EFAULT; 2556 return 0; 2557 2558 case TCP_COOKIE_TRANSACTIONS: { 2559 struct tcp_cookie_transactions ctd; 2560 struct tcp_cookie_values *cvp = tp->cookie_values; 2561 2562 if (get_user(len, optlen)) 2563 return -EFAULT; 2564 if (len < sizeof(ctd)) 2565 return -EINVAL; 2566 2567 memset(&ctd, 0, sizeof(ctd)); 2568 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ? 2569 TCP_COOKIE_IN_ALWAYS : 0) 2570 | (tp->rx_opt.cookie_out_never ? 2571 TCP_COOKIE_OUT_NEVER : 0); 2572 2573 if (cvp != NULL) { 2574 ctd.tcpct_flags |= (cvp->s_data_in ? 2575 TCP_S_DATA_IN : 0) 2576 | (cvp->s_data_out ? 2577 TCP_S_DATA_OUT : 0); 2578 2579 ctd.tcpct_cookie_desired = cvp->cookie_desired; 2580 ctd.tcpct_s_data_desired = cvp->s_data_desired; 2581 2582 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0], 2583 cvp->cookie_pair_size); 2584 ctd.tcpct_used = cvp->cookie_pair_size; 2585 } 2586 2587 if (put_user(sizeof(ctd), optlen)) 2588 return -EFAULT; 2589 if (copy_to_user(optval, &ctd, sizeof(ctd))) 2590 return -EFAULT; 2591 return 0; 2592 } 2593 default: 2594 return -ENOPROTOOPT; 2595 } 2596 2597 if (put_user(len, optlen)) 2598 return -EFAULT; 2599 if (copy_to_user(optval, &val, len)) 2600 return -EFAULT; 2601 return 0; 2602 } 2603 2604 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 2605 int __user *optlen) 2606 { 2607 struct inet_connection_sock *icsk = inet_csk(sk); 2608 2609 if (level != SOL_TCP) 2610 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 2611 optval, optlen); 2612 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2613 } 2614 2615 #ifdef CONFIG_COMPAT 2616 int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 2617 char __user *optval, int __user *optlen) 2618 { 2619 if (level != SOL_TCP) 2620 return inet_csk_compat_getsockopt(sk, level, optname, 2621 optval, optlen); 2622 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2623 } 2624 2625 EXPORT_SYMBOL(compat_tcp_getsockopt); 2626 #endif 2627 2628 struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features) 2629 { 2630 struct sk_buff *segs = ERR_PTR(-EINVAL); 2631 struct tcphdr *th; 2632 unsigned thlen; 2633 unsigned int seq; 2634 __be32 delta; 2635 unsigned int oldlen; 2636 unsigned int mss; 2637 2638 if (!pskb_may_pull(skb, sizeof(*th))) 2639 goto out; 2640 2641 th = tcp_hdr(skb); 2642 thlen = th->doff * 4; 2643 if (thlen < sizeof(*th)) 2644 goto out; 2645 2646 if (!pskb_may_pull(skb, thlen)) 2647 goto out; 2648 2649 oldlen = (u16)~skb->len; 2650 __skb_pull(skb, thlen); 2651 2652 mss = skb_shinfo(skb)->gso_size; 2653 if (unlikely(skb->len <= mss)) 2654 goto out; 2655 2656 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2657 /* Packet is from an untrusted source, reset gso_segs. */ 2658 int type = skb_shinfo(skb)->gso_type; 2659 2660 if (unlikely(type & 2661 ~(SKB_GSO_TCPV4 | 2662 SKB_GSO_DODGY | 2663 SKB_GSO_TCP_ECN | 2664 SKB_GSO_TCPV6 | 2665 0) || 2666 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))) 2667 goto out; 2668 2669 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2670 2671 segs = NULL; 2672 goto out; 2673 } 2674 2675 segs = skb_segment(skb, features); 2676 if (IS_ERR(segs)) 2677 goto out; 2678 2679 delta = htonl(oldlen + (thlen + mss)); 2680 2681 skb = segs; 2682 th = tcp_hdr(skb); 2683 seq = ntohl(th->seq); 2684 2685 do { 2686 th->fin = th->psh = 0; 2687 2688 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2689 (__force u32)delta)); 2690 if (skb->ip_summed != CHECKSUM_PARTIAL) 2691 th->check = 2692 csum_fold(csum_partial(skb_transport_header(skb), 2693 thlen, skb->csum)); 2694 2695 seq += mss; 2696 skb = skb->next; 2697 th = tcp_hdr(skb); 2698 2699 th->seq = htonl(seq); 2700 th->cwr = 0; 2701 } while (skb->next); 2702 2703 delta = htonl(oldlen + (skb->tail - skb->transport_header) + 2704 skb->data_len); 2705 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2706 (__force u32)delta)); 2707 if (skb->ip_summed != CHECKSUM_PARTIAL) 2708 th->check = csum_fold(csum_partial(skb_transport_header(skb), 2709 thlen, skb->csum)); 2710 2711 out: 2712 return segs; 2713 } 2714 EXPORT_SYMBOL(tcp_tso_segment); 2715 2716 struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) 2717 { 2718 struct sk_buff **pp = NULL; 2719 struct sk_buff *p; 2720 struct tcphdr *th; 2721 struct tcphdr *th2; 2722 unsigned int len; 2723 unsigned int thlen; 2724 __be32 flags; 2725 unsigned int mss = 1; 2726 unsigned int hlen; 2727 unsigned int off; 2728 int flush = 1; 2729 int i; 2730 2731 off = skb_gro_offset(skb); 2732 hlen = off + sizeof(*th); 2733 th = skb_gro_header_fast(skb, off); 2734 if (skb_gro_header_hard(skb, hlen)) { 2735 th = skb_gro_header_slow(skb, hlen, off); 2736 if (unlikely(!th)) 2737 goto out; 2738 } 2739 2740 thlen = th->doff * 4; 2741 if (thlen < sizeof(*th)) 2742 goto out; 2743 2744 hlen = off + thlen; 2745 if (skb_gro_header_hard(skb, hlen)) { 2746 th = skb_gro_header_slow(skb, hlen, off); 2747 if (unlikely(!th)) 2748 goto out; 2749 } 2750 2751 skb_gro_pull(skb, thlen); 2752 2753 len = skb_gro_len(skb); 2754 flags = tcp_flag_word(th); 2755 2756 for (; (p = *head); head = &p->next) { 2757 if (!NAPI_GRO_CB(p)->same_flow) 2758 continue; 2759 2760 th2 = tcp_hdr(p); 2761 2762 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) { 2763 NAPI_GRO_CB(p)->same_flow = 0; 2764 continue; 2765 } 2766 2767 goto found; 2768 } 2769 2770 goto out_check_final; 2771 2772 found: 2773 flush = NAPI_GRO_CB(p)->flush; 2774 flush |= (__force int)(flags & TCP_FLAG_CWR); 2775 flush |= (__force int)((flags ^ tcp_flag_word(th2)) & 2776 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH)); 2777 flush |= (__force int)(th->ack_seq ^ th2->ack_seq); 2778 for (i = sizeof(*th); i < thlen; i += 4) 2779 flush |= *(u32 *)((u8 *)th + i) ^ 2780 *(u32 *)((u8 *)th2 + i); 2781 2782 mss = skb_shinfo(p)->gso_size; 2783 2784 flush |= (len - 1) >= mss; 2785 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); 2786 2787 if (flush || skb_gro_receive(head, skb)) { 2788 mss = 1; 2789 goto out_check_final; 2790 } 2791 2792 p = *head; 2793 th2 = tcp_hdr(p); 2794 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); 2795 2796 out_check_final: 2797 flush = len < mss; 2798 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH | 2799 TCP_FLAG_RST | TCP_FLAG_SYN | 2800 TCP_FLAG_FIN)); 2801 2802 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush)) 2803 pp = head; 2804 2805 out: 2806 NAPI_GRO_CB(skb)->flush |= flush; 2807 2808 return pp; 2809 } 2810 EXPORT_SYMBOL(tcp_gro_receive); 2811 2812 int tcp_gro_complete(struct sk_buff *skb) 2813 { 2814 struct tcphdr *th = tcp_hdr(skb); 2815 2816 skb->csum_start = skb_transport_header(skb) - skb->head; 2817 skb->csum_offset = offsetof(struct tcphdr, check); 2818 skb->ip_summed = CHECKSUM_PARTIAL; 2819 2820 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 2821 2822 if (th->cwr) 2823 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 2824 2825 return 0; 2826 } 2827 EXPORT_SYMBOL(tcp_gro_complete); 2828 2829 #ifdef CONFIG_TCP_MD5SIG 2830 static unsigned long tcp_md5sig_users; 2831 static struct tcp_md5sig_pool * __percpu *tcp_md5sig_pool; 2832 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock); 2833 2834 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool * __percpu *pool) 2835 { 2836 int cpu; 2837 for_each_possible_cpu(cpu) { 2838 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu); 2839 if (p) { 2840 if (p->md5_desc.tfm) 2841 crypto_free_hash(p->md5_desc.tfm); 2842 kfree(p); 2843 } 2844 } 2845 free_percpu(pool); 2846 } 2847 2848 void tcp_free_md5sig_pool(void) 2849 { 2850 struct tcp_md5sig_pool * __percpu *pool = NULL; 2851 2852 spin_lock_bh(&tcp_md5sig_pool_lock); 2853 if (--tcp_md5sig_users == 0) { 2854 pool = tcp_md5sig_pool; 2855 tcp_md5sig_pool = NULL; 2856 } 2857 spin_unlock_bh(&tcp_md5sig_pool_lock); 2858 if (pool) 2859 __tcp_free_md5sig_pool(pool); 2860 } 2861 2862 EXPORT_SYMBOL(tcp_free_md5sig_pool); 2863 2864 static struct tcp_md5sig_pool * __percpu * 2865 __tcp_alloc_md5sig_pool(struct sock *sk) 2866 { 2867 int cpu; 2868 struct tcp_md5sig_pool * __percpu *pool; 2869 2870 pool = alloc_percpu(struct tcp_md5sig_pool *); 2871 if (!pool) 2872 return NULL; 2873 2874 for_each_possible_cpu(cpu) { 2875 struct tcp_md5sig_pool *p; 2876 struct crypto_hash *hash; 2877 2878 p = kzalloc(sizeof(*p), sk->sk_allocation); 2879 if (!p) 2880 goto out_free; 2881 *per_cpu_ptr(pool, cpu) = p; 2882 2883 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 2884 if (!hash || IS_ERR(hash)) 2885 goto out_free; 2886 2887 p->md5_desc.tfm = hash; 2888 } 2889 return pool; 2890 out_free: 2891 __tcp_free_md5sig_pool(pool); 2892 return NULL; 2893 } 2894 2895 struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *sk) 2896 { 2897 struct tcp_md5sig_pool * __percpu *pool; 2898 int alloc = 0; 2899 2900 retry: 2901 spin_lock_bh(&tcp_md5sig_pool_lock); 2902 pool = tcp_md5sig_pool; 2903 if (tcp_md5sig_users++ == 0) { 2904 alloc = 1; 2905 spin_unlock_bh(&tcp_md5sig_pool_lock); 2906 } else if (!pool) { 2907 tcp_md5sig_users--; 2908 spin_unlock_bh(&tcp_md5sig_pool_lock); 2909 cpu_relax(); 2910 goto retry; 2911 } else 2912 spin_unlock_bh(&tcp_md5sig_pool_lock); 2913 2914 if (alloc) { 2915 /* we cannot hold spinlock here because this may sleep. */ 2916 struct tcp_md5sig_pool * __percpu *p; 2917 2918 p = __tcp_alloc_md5sig_pool(sk); 2919 spin_lock_bh(&tcp_md5sig_pool_lock); 2920 if (!p) { 2921 tcp_md5sig_users--; 2922 spin_unlock_bh(&tcp_md5sig_pool_lock); 2923 return NULL; 2924 } 2925 pool = tcp_md5sig_pool; 2926 if (pool) { 2927 /* oops, it has already been assigned. */ 2928 spin_unlock_bh(&tcp_md5sig_pool_lock); 2929 __tcp_free_md5sig_pool(p); 2930 } else { 2931 tcp_md5sig_pool = pool = p; 2932 spin_unlock_bh(&tcp_md5sig_pool_lock); 2933 } 2934 } 2935 return pool; 2936 } 2937 2938 EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 2939 2940 2941 /** 2942 * tcp_get_md5sig_pool - get md5sig_pool for this user 2943 * 2944 * We use percpu structure, so if we succeed, we exit with preemption 2945 * and BH disabled, to make sure another thread or softirq handling 2946 * wont try to get same context. 2947 */ 2948 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) 2949 { 2950 struct tcp_md5sig_pool * __percpu *p; 2951 2952 local_bh_disable(); 2953 2954 spin_lock(&tcp_md5sig_pool_lock); 2955 p = tcp_md5sig_pool; 2956 if (p) 2957 tcp_md5sig_users++; 2958 spin_unlock(&tcp_md5sig_pool_lock); 2959 2960 if (p) 2961 return *per_cpu_ptr(p, smp_processor_id()); 2962 2963 local_bh_enable(); 2964 return NULL; 2965 } 2966 EXPORT_SYMBOL(tcp_get_md5sig_pool); 2967 2968 void tcp_put_md5sig_pool(void) 2969 { 2970 local_bh_enable(); 2971 tcp_free_md5sig_pool(); 2972 } 2973 EXPORT_SYMBOL(tcp_put_md5sig_pool); 2974 2975 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, 2976 struct tcphdr *th) 2977 { 2978 struct scatterlist sg; 2979 int err; 2980 2981 __sum16 old_checksum = th->check; 2982 th->check = 0; 2983 /* options aren't included in the hash */ 2984 sg_init_one(&sg, th, sizeof(struct tcphdr)); 2985 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr)); 2986 th->check = old_checksum; 2987 return err; 2988 } 2989 2990 EXPORT_SYMBOL(tcp_md5_hash_header); 2991 2992 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 2993 struct sk_buff *skb, unsigned header_len) 2994 { 2995 struct scatterlist sg; 2996 const struct tcphdr *tp = tcp_hdr(skb); 2997 struct hash_desc *desc = &hp->md5_desc; 2998 unsigned i; 2999 const unsigned head_data_len = skb_headlen(skb) > header_len ? 3000 skb_headlen(skb) - header_len : 0; 3001 const struct skb_shared_info *shi = skb_shinfo(skb); 3002 3003 sg_init_table(&sg, 1); 3004 3005 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 3006 if (crypto_hash_update(desc, &sg, head_data_len)) 3007 return 1; 3008 3009 for (i = 0; i < shi->nr_frags; ++i) { 3010 const struct skb_frag_struct *f = &shi->frags[i]; 3011 sg_set_page(&sg, f->page, f->size, f->page_offset); 3012 if (crypto_hash_update(desc, &sg, f->size)) 3013 return 1; 3014 } 3015 3016 return 0; 3017 } 3018 3019 EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3020 3021 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key) 3022 { 3023 struct scatterlist sg; 3024 3025 sg_init_one(&sg, key->key, key->keylen); 3026 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); 3027 } 3028 3029 EXPORT_SYMBOL(tcp_md5_hash_key); 3030 3031 #endif 3032 3033 /** 3034 * Each Responder maintains up to two secret values concurrently for 3035 * efficient secret rollover. Each secret value has 4 states: 3036 * 3037 * Generating. (tcp_secret_generating != tcp_secret_primary) 3038 * Generates new Responder-Cookies, but not yet used for primary 3039 * verification. This is a short-term state, typically lasting only 3040 * one round trip time (RTT). 3041 * 3042 * Primary. (tcp_secret_generating == tcp_secret_primary) 3043 * Used both for generation and primary verification. 3044 * 3045 * Retiring. (tcp_secret_retiring != tcp_secret_secondary) 3046 * Used for verification, until the first failure that can be 3047 * verified by the newer Generating secret. At that time, this 3048 * cookie's state is changed to Secondary, and the Generating 3049 * cookie's state is changed to Primary. This is a short-term state, 3050 * typically lasting only one round trip time (RTT). 3051 * 3052 * Secondary. (tcp_secret_retiring == tcp_secret_secondary) 3053 * Used for secondary verification, after primary verification 3054 * failures. This state lasts no more than twice the Maximum Segment 3055 * Lifetime (2MSL). Then, the secret is discarded. 3056 */ 3057 struct tcp_cookie_secret { 3058 /* The secret is divided into two parts. The digest part is the 3059 * equivalent of previously hashing a secret and saving the state, 3060 * and serves as an initialization vector (IV). The message part 3061 * serves as the trailing secret. 3062 */ 3063 u32 secrets[COOKIE_WORKSPACE_WORDS]; 3064 unsigned long expires; 3065 }; 3066 3067 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL) 3068 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2) 3069 #define TCP_SECRET_LIFE (HZ * 600) 3070 3071 static struct tcp_cookie_secret tcp_secret_one; 3072 static struct tcp_cookie_secret tcp_secret_two; 3073 3074 /* Essentially a circular list, without dynamic allocation. */ 3075 static struct tcp_cookie_secret *tcp_secret_generating; 3076 static struct tcp_cookie_secret *tcp_secret_primary; 3077 static struct tcp_cookie_secret *tcp_secret_retiring; 3078 static struct tcp_cookie_secret *tcp_secret_secondary; 3079 3080 static DEFINE_SPINLOCK(tcp_secret_locker); 3081 3082 /* Select a pseudo-random word in the cookie workspace. 3083 */ 3084 static inline u32 tcp_cookie_work(const u32 *ws, const int n) 3085 { 3086 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])]; 3087 } 3088 3089 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed. 3090 * Called in softirq context. 3091 * Returns: 0 for success. 3092 */ 3093 int tcp_cookie_generator(u32 *bakery) 3094 { 3095 unsigned long jiffy = jiffies; 3096 3097 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) { 3098 spin_lock_bh(&tcp_secret_locker); 3099 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) { 3100 /* refreshed by another */ 3101 memcpy(bakery, 3102 &tcp_secret_generating->secrets[0], 3103 COOKIE_WORKSPACE_WORDS); 3104 } else { 3105 /* still needs refreshing */ 3106 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS); 3107 3108 /* The first time, paranoia assumes that the 3109 * randomization function isn't as strong. But, 3110 * this secret initialization is delayed until 3111 * the last possible moment (packet arrival). 3112 * Although that time is observable, it is 3113 * unpredictably variable. Mash in the most 3114 * volatile clock bits available, and expire the 3115 * secret extra quickly. 3116 */ 3117 if (unlikely(tcp_secret_primary->expires == 3118 tcp_secret_secondary->expires)) { 3119 struct timespec tv; 3120 3121 getnstimeofday(&tv); 3122 bakery[COOKIE_DIGEST_WORDS+0] ^= 3123 (u32)tv.tv_nsec; 3124 3125 tcp_secret_secondary->expires = jiffy 3126 + TCP_SECRET_1MSL 3127 + (0x0f & tcp_cookie_work(bakery, 0)); 3128 } else { 3129 tcp_secret_secondary->expires = jiffy 3130 + TCP_SECRET_LIFE 3131 + (0xff & tcp_cookie_work(bakery, 1)); 3132 tcp_secret_primary->expires = jiffy 3133 + TCP_SECRET_2MSL 3134 + (0x1f & tcp_cookie_work(bakery, 2)); 3135 } 3136 memcpy(&tcp_secret_secondary->secrets[0], 3137 bakery, COOKIE_WORKSPACE_WORDS); 3138 3139 rcu_assign_pointer(tcp_secret_generating, 3140 tcp_secret_secondary); 3141 rcu_assign_pointer(tcp_secret_retiring, 3142 tcp_secret_primary); 3143 /* 3144 * Neither call_rcu() nor synchronize_rcu() needed. 3145 * Retiring data is not freed. It is replaced after 3146 * further (locked) pointer updates, and a quiet time 3147 * (minimum 1MSL, maximum LIFE - 2MSL). 3148 */ 3149 } 3150 spin_unlock_bh(&tcp_secret_locker); 3151 } else { 3152 rcu_read_lock_bh(); 3153 memcpy(bakery, 3154 &rcu_dereference(tcp_secret_generating)->secrets[0], 3155 COOKIE_WORKSPACE_WORDS); 3156 rcu_read_unlock_bh(); 3157 } 3158 return 0; 3159 } 3160 EXPORT_SYMBOL(tcp_cookie_generator); 3161 3162 void tcp_done(struct sock *sk) 3163 { 3164 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3165 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3166 3167 tcp_set_state(sk, TCP_CLOSE); 3168 tcp_clear_xmit_timers(sk); 3169 3170 sk->sk_shutdown = SHUTDOWN_MASK; 3171 3172 if (!sock_flag(sk, SOCK_DEAD)) 3173 sk->sk_state_change(sk); 3174 else 3175 inet_csk_destroy_sock(sk); 3176 } 3177 EXPORT_SYMBOL_GPL(tcp_done); 3178 3179 extern struct tcp_congestion_ops tcp_reno; 3180 3181 static __initdata unsigned long thash_entries; 3182 static int __init set_thash_entries(char *str) 3183 { 3184 if (!str) 3185 return 0; 3186 thash_entries = simple_strtoul(str, &str, 0); 3187 return 1; 3188 } 3189 __setup("thash_entries=", set_thash_entries); 3190 3191 void __init tcp_init(void) 3192 { 3193 struct sk_buff *skb = NULL; 3194 unsigned long nr_pages, limit; 3195 int order, i, max_share; 3196 unsigned long jiffy = jiffies; 3197 3198 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); 3199 3200 percpu_counter_init(&tcp_sockets_allocated, 0); 3201 percpu_counter_init(&tcp_orphan_count, 0); 3202 tcp_hashinfo.bind_bucket_cachep = 3203 kmem_cache_create("tcp_bind_bucket", 3204 sizeof(struct inet_bind_bucket), 0, 3205 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3206 3207 /* Size and allocate the main established and bind bucket 3208 * hash tables. 3209 * 3210 * The methodology is similar to that of the buffer cache. 3211 */ 3212 tcp_hashinfo.ehash = 3213 alloc_large_system_hash("TCP established", 3214 sizeof(struct inet_ehash_bucket), 3215 thash_entries, 3216 (totalram_pages >= 128 * 1024) ? 3217 13 : 15, 3218 0, 3219 NULL, 3220 &tcp_hashinfo.ehash_mask, 3221 thash_entries ? 0 : 512 * 1024); 3222 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) { 3223 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3224 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i); 3225 } 3226 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3227 panic("TCP: failed to alloc ehash_locks"); 3228 tcp_hashinfo.bhash = 3229 alloc_large_system_hash("TCP bind", 3230 sizeof(struct inet_bind_hashbucket), 3231 tcp_hashinfo.ehash_mask + 1, 3232 (totalram_pages >= 128 * 1024) ? 3233 13 : 15, 3234 0, 3235 &tcp_hashinfo.bhash_size, 3236 NULL, 3237 64 * 1024); 3238 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size; 3239 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3240 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3241 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3242 } 3243 3244 /* Try to be a bit smarter and adjust defaults depending 3245 * on available memory. 3246 */ 3247 for (order = 0; ((1 << order) << PAGE_SHIFT) < 3248 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket)); 3249 order++) 3250 ; 3251 if (order >= 4) { 3252 tcp_death_row.sysctl_max_tw_buckets = 180000; 3253 sysctl_tcp_max_orphans = 4096 << (order - 4); 3254 sysctl_max_syn_backlog = 1024; 3255 } else if (order < 3) { 3256 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order); 3257 sysctl_tcp_max_orphans >>= (3 - order); 3258 sysctl_max_syn_backlog = 128; 3259 } 3260 3261 /* Set the pressure threshold to be a fraction of global memory that 3262 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of 3263 * memory, with a floor of 128 pages. 3264 */ 3265 nr_pages = totalram_pages - totalhigh_pages; 3266 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); 3267 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); 3268 limit = max(limit, 128UL); 3269 sysctl_tcp_mem[0] = limit / 4 * 3; 3270 sysctl_tcp_mem[1] = limit; 3271 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; 3272 3273 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3274 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7); 3275 max_share = min(4UL*1024*1024, limit); 3276 3277 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3278 sysctl_tcp_wmem[1] = 16*1024; 3279 sysctl_tcp_wmem[2] = max(64*1024, max_share); 3280 3281 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3282 sysctl_tcp_rmem[1] = 87380; 3283 sysctl_tcp_rmem[2] = max(87380, max_share); 3284 3285 printk(KERN_INFO "TCP: Hash tables configured " 3286 "(established %u bind %u)\n", 3287 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3288 3289 tcp_register_congestion_control(&tcp_reno); 3290 3291 memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets)); 3292 memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets)); 3293 tcp_secret_one.expires = jiffy; /* past due */ 3294 tcp_secret_two.expires = jiffy; /* past due */ 3295 tcp_secret_generating = &tcp_secret_one; 3296 tcp_secret_primary = &tcp_secret_one; 3297 tcp_secret_retiring = &tcp_secret_two; 3298 tcp_secret_secondary = &tcp_secret_two; 3299 } 3300 3301 EXPORT_SYMBOL(tcp_close); 3302 EXPORT_SYMBOL(tcp_disconnect); 3303 EXPORT_SYMBOL(tcp_getsockopt); 3304 EXPORT_SYMBOL(tcp_ioctl); 3305 EXPORT_SYMBOL(tcp_poll); 3306 EXPORT_SYMBOL(tcp_read_sock); 3307 EXPORT_SYMBOL(tcp_recvmsg); 3308 EXPORT_SYMBOL(tcp_sendmsg); 3309 EXPORT_SYMBOL(tcp_splice_read); 3310 EXPORT_SYMBOL(tcp_sendpage); 3311 EXPORT_SYMBOL(tcp_setsockopt); 3312 EXPORT_SYMBOL(tcp_shutdown); 3313