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 sock_rps_record_flow(sk); 612 /* 613 * We can't seek on a socket input 614 */ 615 if (unlikely(*ppos)) 616 return -ESPIPE; 617 618 ret = spliced = 0; 619 620 lock_sock(sk); 621 622 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); 623 while (tss.len) { 624 ret = __tcp_splice_read(sk, &tss); 625 if (ret < 0) 626 break; 627 else if (!ret) { 628 if (spliced) 629 break; 630 if (sock_flag(sk, SOCK_DONE)) 631 break; 632 if (sk->sk_err) { 633 ret = sock_error(sk); 634 break; 635 } 636 if (sk->sk_shutdown & RCV_SHUTDOWN) 637 break; 638 if (sk->sk_state == TCP_CLOSE) { 639 /* 640 * This occurs when user tries to read 641 * from never connected socket. 642 */ 643 if (!sock_flag(sk, SOCK_DONE)) 644 ret = -ENOTCONN; 645 break; 646 } 647 if (!timeo) { 648 ret = -EAGAIN; 649 break; 650 } 651 sk_wait_data(sk, &timeo); 652 if (signal_pending(current)) { 653 ret = sock_intr_errno(timeo); 654 break; 655 } 656 continue; 657 } 658 tss.len -= ret; 659 spliced += ret; 660 661 if (!timeo) 662 break; 663 release_sock(sk); 664 lock_sock(sk); 665 666 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 667 (sk->sk_shutdown & RCV_SHUTDOWN) || 668 signal_pending(current)) 669 break; 670 } 671 672 release_sock(sk); 673 674 if (spliced) 675 return spliced; 676 677 return ret; 678 } 679 680 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) 681 { 682 struct sk_buff *skb; 683 684 /* The TCP header must be at least 32-bit aligned. */ 685 size = ALIGN(size, 4); 686 687 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 688 if (skb) { 689 if (sk_wmem_schedule(sk, skb->truesize)) { 690 /* 691 * Make sure that we have exactly size bytes 692 * available to the caller, no more, no less. 693 */ 694 skb_reserve(skb, skb_tailroom(skb) - size); 695 return skb; 696 } 697 __kfree_skb(skb); 698 } else { 699 sk->sk_prot->enter_memory_pressure(sk); 700 sk_stream_moderate_sndbuf(sk); 701 } 702 return NULL; 703 } 704 705 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, 706 int large_allowed) 707 { 708 struct tcp_sock *tp = tcp_sk(sk); 709 u32 xmit_size_goal, old_size_goal; 710 711 xmit_size_goal = mss_now; 712 713 if (large_allowed && sk_can_gso(sk)) { 714 xmit_size_goal = ((sk->sk_gso_max_size - 1) - 715 inet_csk(sk)->icsk_af_ops->net_header_len - 716 inet_csk(sk)->icsk_ext_hdr_len - 717 tp->tcp_header_len); 718 719 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal); 720 721 /* We try hard to avoid divides here */ 722 old_size_goal = tp->xmit_size_goal_segs * mss_now; 723 724 if (likely(old_size_goal <= xmit_size_goal && 725 old_size_goal + mss_now > xmit_size_goal)) { 726 xmit_size_goal = old_size_goal; 727 } else { 728 tp->xmit_size_goal_segs = xmit_size_goal / mss_now; 729 xmit_size_goal = tp->xmit_size_goal_segs * mss_now; 730 } 731 } 732 733 return max(xmit_size_goal, mss_now); 734 } 735 736 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) 737 { 738 int mss_now; 739 740 mss_now = tcp_current_mss(sk); 741 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); 742 743 return mss_now; 744 } 745 746 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, 747 size_t psize, int flags) 748 { 749 struct tcp_sock *tp = tcp_sk(sk); 750 int mss_now, size_goal; 751 int err; 752 ssize_t copied; 753 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 754 755 /* Wait for a connection to finish. */ 756 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 757 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 758 goto out_err; 759 760 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 761 762 mss_now = tcp_send_mss(sk, &size_goal, flags); 763 copied = 0; 764 765 err = -EPIPE; 766 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 767 goto out_err; 768 769 while (psize > 0) { 770 struct sk_buff *skb = tcp_write_queue_tail(sk); 771 struct page *page = pages[poffset / PAGE_SIZE]; 772 int copy, i, can_coalesce; 773 int offset = poffset % PAGE_SIZE; 774 int size = min_t(size_t, psize, PAGE_SIZE - offset); 775 776 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { 777 new_segment: 778 if (!sk_stream_memory_free(sk)) 779 goto wait_for_sndbuf; 780 781 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); 782 if (!skb) 783 goto wait_for_memory; 784 785 skb_entail(sk, skb); 786 copy = size_goal; 787 } 788 789 if (copy > size) 790 copy = size; 791 792 i = skb_shinfo(skb)->nr_frags; 793 can_coalesce = skb_can_coalesce(skb, i, page, offset); 794 if (!can_coalesce && i >= MAX_SKB_FRAGS) { 795 tcp_mark_push(tp, skb); 796 goto new_segment; 797 } 798 if (!sk_wmem_schedule(sk, copy)) 799 goto wait_for_memory; 800 801 if (can_coalesce) { 802 skb_shinfo(skb)->frags[i - 1].size += copy; 803 } else { 804 get_page(page); 805 skb_fill_page_desc(skb, i, page, offset, copy); 806 } 807 808 skb->len += copy; 809 skb->data_len += copy; 810 skb->truesize += copy; 811 sk->sk_wmem_queued += copy; 812 sk_mem_charge(sk, copy); 813 skb->ip_summed = CHECKSUM_PARTIAL; 814 tp->write_seq += copy; 815 TCP_SKB_CB(skb)->end_seq += copy; 816 skb_shinfo(skb)->gso_segs = 0; 817 818 if (!copied) 819 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 820 821 copied += copy; 822 poffset += copy; 823 if (!(psize -= copy)) 824 goto out; 825 826 if (skb->len < size_goal || (flags & MSG_OOB)) 827 continue; 828 829 if (forced_push(tp)) { 830 tcp_mark_push(tp, skb); 831 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 832 } else if (skb == tcp_send_head(sk)) 833 tcp_push_one(sk, mss_now); 834 continue; 835 836 wait_for_sndbuf: 837 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 838 wait_for_memory: 839 if (copied) 840 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 841 842 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 843 goto do_error; 844 845 mss_now = tcp_send_mss(sk, &size_goal, flags); 846 } 847 848 out: 849 if (copied) 850 tcp_push(sk, flags, mss_now, tp->nonagle); 851 return copied; 852 853 do_error: 854 if (copied) 855 goto out; 856 out_err: 857 return sk_stream_error(sk, flags, err); 858 } 859 860 ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, 861 size_t size, int flags) 862 { 863 ssize_t res; 864 struct sock *sk = sock->sk; 865 866 if (!(sk->sk_route_caps & NETIF_F_SG) || 867 !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) 868 return sock_no_sendpage(sock, page, offset, size, flags); 869 870 lock_sock(sk); 871 TCP_CHECK_TIMER(sk); 872 res = do_tcp_sendpages(sk, &page, offset, size, flags); 873 TCP_CHECK_TIMER(sk); 874 release_sock(sk); 875 return res; 876 } 877 878 #define TCP_PAGE(sk) (sk->sk_sndmsg_page) 879 #define TCP_OFF(sk) (sk->sk_sndmsg_off) 880 881 static inline int select_size(struct sock *sk, int sg) 882 { 883 struct tcp_sock *tp = tcp_sk(sk); 884 int tmp = tp->mss_cache; 885 886 if (sg) { 887 if (sk_can_gso(sk)) 888 tmp = 0; 889 else { 890 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); 891 892 if (tmp >= pgbreak && 893 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) 894 tmp = pgbreak; 895 } 896 } 897 898 return tmp; 899 } 900 901 int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, 902 size_t size) 903 { 904 struct sock *sk = sock->sk; 905 struct iovec *iov; 906 struct tcp_sock *tp = tcp_sk(sk); 907 struct sk_buff *skb; 908 int iovlen, flags; 909 int mss_now, size_goal; 910 int sg, err, copied; 911 long timeo; 912 913 lock_sock(sk); 914 TCP_CHECK_TIMER(sk); 915 916 flags = msg->msg_flags; 917 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 918 919 /* Wait for a connection to finish. */ 920 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 921 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 922 goto out_err; 923 924 /* This should be in poll */ 925 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 926 927 mss_now = tcp_send_mss(sk, &size_goal, flags); 928 929 /* Ok commence sending. */ 930 iovlen = msg->msg_iovlen; 931 iov = msg->msg_iov; 932 copied = 0; 933 934 err = -EPIPE; 935 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 936 goto out_err; 937 938 sg = sk->sk_route_caps & NETIF_F_SG; 939 940 while (--iovlen >= 0) { 941 int seglen = iov->iov_len; 942 unsigned char __user *from = iov->iov_base; 943 944 iov++; 945 946 while (seglen > 0) { 947 int copy = 0; 948 int max = size_goal; 949 950 skb = tcp_write_queue_tail(sk); 951 if (tcp_send_head(sk)) { 952 if (skb->ip_summed == CHECKSUM_NONE) 953 max = mss_now; 954 copy = max - skb->len; 955 } 956 957 if (copy <= 0) { 958 new_segment: 959 /* Allocate new segment. If the interface is SG, 960 * allocate skb fitting to single page. 961 */ 962 if (!sk_stream_memory_free(sk)) 963 goto wait_for_sndbuf; 964 965 skb = sk_stream_alloc_skb(sk, 966 select_size(sk, sg), 967 sk->sk_allocation); 968 if (!skb) 969 goto wait_for_memory; 970 971 /* 972 * Check whether we can use HW checksum. 973 */ 974 if (sk->sk_route_caps & NETIF_F_ALL_CSUM) 975 skb->ip_summed = CHECKSUM_PARTIAL; 976 977 skb_entail(sk, skb); 978 copy = size_goal; 979 max = size_goal; 980 } 981 982 /* Try to append data to the end of skb. */ 983 if (copy > seglen) 984 copy = seglen; 985 986 /* Where to copy to? */ 987 if (skb_tailroom(skb) > 0) { 988 /* We have some space in skb head. Superb! */ 989 if (copy > skb_tailroom(skb)) 990 copy = skb_tailroom(skb); 991 if ((err = skb_add_data(skb, from, copy)) != 0) 992 goto do_fault; 993 } else { 994 int merge = 0; 995 int i = skb_shinfo(skb)->nr_frags; 996 struct page *page = TCP_PAGE(sk); 997 int off = TCP_OFF(sk); 998 999 if (skb_can_coalesce(skb, i, page, off) && 1000 off != PAGE_SIZE) { 1001 /* We can extend the last page 1002 * fragment. */ 1003 merge = 1; 1004 } else if (i == MAX_SKB_FRAGS || !sg) { 1005 /* Need to add new fragment and cannot 1006 * do this because interface is non-SG, 1007 * or because all the page slots are 1008 * busy. */ 1009 tcp_mark_push(tp, skb); 1010 goto new_segment; 1011 } else if (page) { 1012 if (off == PAGE_SIZE) { 1013 put_page(page); 1014 TCP_PAGE(sk) = page = NULL; 1015 off = 0; 1016 } 1017 } else 1018 off = 0; 1019 1020 if (copy > PAGE_SIZE - off) 1021 copy = PAGE_SIZE - off; 1022 1023 if (!sk_wmem_schedule(sk, copy)) 1024 goto wait_for_memory; 1025 1026 if (!page) { 1027 /* Allocate new cache page. */ 1028 if (!(page = sk_stream_alloc_page(sk))) 1029 goto wait_for_memory; 1030 } 1031 1032 /* Time to copy data. We are close to 1033 * the end! */ 1034 err = skb_copy_to_page(sk, from, skb, page, 1035 off, copy); 1036 if (err) { 1037 /* If this page was new, give it to the 1038 * socket so it does not get leaked. 1039 */ 1040 if (!TCP_PAGE(sk)) { 1041 TCP_PAGE(sk) = page; 1042 TCP_OFF(sk) = 0; 1043 } 1044 goto do_error; 1045 } 1046 1047 /* Update the skb. */ 1048 if (merge) { 1049 skb_shinfo(skb)->frags[i - 1].size += 1050 copy; 1051 } else { 1052 skb_fill_page_desc(skb, i, page, off, copy); 1053 if (TCP_PAGE(sk)) { 1054 get_page(page); 1055 } else if (off + copy < PAGE_SIZE) { 1056 get_page(page); 1057 TCP_PAGE(sk) = page; 1058 } 1059 } 1060 1061 TCP_OFF(sk) = off + copy; 1062 } 1063 1064 if (!copied) 1065 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; 1066 1067 tp->write_seq += copy; 1068 TCP_SKB_CB(skb)->end_seq += copy; 1069 skb_shinfo(skb)->gso_segs = 0; 1070 1071 from += copy; 1072 copied += copy; 1073 if ((seglen -= copy) == 0 && iovlen == 0) 1074 goto out; 1075 1076 if (skb->len < max || (flags & MSG_OOB)) 1077 continue; 1078 1079 if (forced_push(tp)) { 1080 tcp_mark_push(tp, skb); 1081 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1082 } else if (skb == tcp_send_head(sk)) 1083 tcp_push_one(sk, mss_now); 1084 continue; 1085 1086 wait_for_sndbuf: 1087 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1088 wait_for_memory: 1089 if (copied) 1090 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 1091 1092 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 1093 goto do_error; 1094 1095 mss_now = tcp_send_mss(sk, &size_goal, flags); 1096 } 1097 } 1098 1099 out: 1100 if (copied) 1101 tcp_push(sk, flags, mss_now, tp->nonagle); 1102 TCP_CHECK_TIMER(sk); 1103 release_sock(sk); 1104 return copied; 1105 1106 do_fault: 1107 if (!skb->len) { 1108 tcp_unlink_write_queue(skb, sk); 1109 /* It is the one place in all of TCP, except connection 1110 * reset, where we can be unlinking the send_head. 1111 */ 1112 tcp_check_send_head(sk, skb); 1113 sk_wmem_free_skb(sk, skb); 1114 } 1115 1116 do_error: 1117 if (copied) 1118 goto out; 1119 out_err: 1120 err = sk_stream_error(sk, flags, err); 1121 TCP_CHECK_TIMER(sk); 1122 release_sock(sk); 1123 return err; 1124 } 1125 1126 /* 1127 * Handle reading urgent data. BSD has very simple semantics for 1128 * this, no blocking and very strange errors 8) 1129 */ 1130 1131 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) 1132 { 1133 struct tcp_sock *tp = tcp_sk(sk); 1134 1135 /* No URG data to read. */ 1136 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1137 tp->urg_data == TCP_URG_READ) 1138 return -EINVAL; /* Yes this is right ! */ 1139 1140 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1141 return -ENOTCONN; 1142 1143 if (tp->urg_data & TCP_URG_VALID) { 1144 int err = 0; 1145 char c = tp->urg_data; 1146 1147 if (!(flags & MSG_PEEK)) 1148 tp->urg_data = TCP_URG_READ; 1149 1150 /* Read urgent data. */ 1151 msg->msg_flags |= MSG_OOB; 1152 1153 if (len > 0) { 1154 if (!(flags & MSG_TRUNC)) 1155 err = memcpy_toiovec(msg->msg_iov, &c, 1); 1156 len = 1; 1157 } else 1158 msg->msg_flags |= MSG_TRUNC; 1159 1160 return err ? -EFAULT : len; 1161 } 1162 1163 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1164 return 0; 1165 1166 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1167 * the available implementations agree in this case: 1168 * this call should never block, independent of the 1169 * blocking state of the socket. 1170 * Mike <pall@rz.uni-karlsruhe.de> 1171 */ 1172 return -EAGAIN; 1173 } 1174 1175 /* Clean up the receive buffer for full frames taken by the user, 1176 * then send an ACK if necessary. COPIED is the number of bytes 1177 * tcp_recvmsg has given to the user so far, it speeds up the 1178 * calculation of whether or not we must ACK for the sake of 1179 * a window update. 1180 */ 1181 void tcp_cleanup_rbuf(struct sock *sk, int copied) 1182 { 1183 struct tcp_sock *tp = tcp_sk(sk); 1184 int time_to_ack = 0; 1185 1186 #if TCP_DEBUG 1187 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1188 1189 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), 1190 KERN_INFO "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", 1191 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); 1192 #endif 1193 1194 if (inet_csk_ack_scheduled(sk)) { 1195 const struct inet_connection_sock *icsk = inet_csk(sk); 1196 /* Delayed ACKs frequently hit locked sockets during bulk 1197 * receive. */ 1198 if (icsk->icsk_ack.blocked || 1199 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1200 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1201 /* 1202 * If this read emptied read buffer, we send ACK, if 1203 * connection is not bidirectional, user drained 1204 * receive buffer and there was a small segment 1205 * in queue. 1206 */ 1207 (copied > 0 && 1208 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1209 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1210 !icsk->icsk_ack.pingpong)) && 1211 !atomic_read(&sk->sk_rmem_alloc))) 1212 time_to_ack = 1; 1213 } 1214 1215 /* We send an ACK if we can now advertise a non-zero window 1216 * which has been raised "significantly". 1217 * 1218 * Even if window raised up to infinity, do not send window open ACK 1219 * in states, where we will not receive more. It is useless. 1220 */ 1221 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1222 __u32 rcv_window_now = tcp_receive_window(tp); 1223 1224 /* Optimize, __tcp_select_window() is not cheap. */ 1225 if (2*rcv_window_now <= tp->window_clamp) { 1226 __u32 new_window = __tcp_select_window(sk); 1227 1228 /* Send ACK now, if this read freed lots of space 1229 * in our buffer. Certainly, new_window is new window. 1230 * We can advertise it now, if it is not less than current one. 1231 * "Lots" means "at least twice" here. 1232 */ 1233 if (new_window && new_window >= 2 * rcv_window_now) 1234 time_to_ack = 1; 1235 } 1236 } 1237 if (time_to_ack) 1238 tcp_send_ack(sk); 1239 } 1240 1241 static void tcp_prequeue_process(struct sock *sk) 1242 { 1243 struct sk_buff *skb; 1244 struct tcp_sock *tp = tcp_sk(sk); 1245 1246 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); 1247 1248 /* RX process wants to run with disabled BHs, though it is not 1249 * necessary */ 1250 local_bh_disable(); 1251 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) 1252 sk_backlog_rcv(sk, skb); 1253 local_bh_enable(); 1254 1255 /* Clear memory counter. */ 1256 tp->ucopy.memory = 0; 1257 } 1258 1259 #ifdef CONFIG_NET_DMA 1260 static void tcp_service_net_dma(struct sock *sk, bool wait) 1261 { 1262 dma_cookie_t done, used; 1263 dma_cookie_t last_issued; 1264 struct tcp_sock *tp = tcp_sk(sk); 1265 1266 if (!tp->ucopy.dma_chan) 1267 return; 1268 1269 last_issued = tp->ucopy.dma_cookie; 1270 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1271 1272 do { 1273 if (dma_async_memcpy_complete(tp->ucopy.dma_chan, 1274 last_issued, &done, 1275 &used) == DMA_SUCCESS) { 1276 /* Safe to free early-copied skbs now */ 1277 __skb_queue_purge(&sk->sk_async_wait_queue); 1278 break; 1279 } else { 1280 struct sk_buff *skb; 1281 while ((skb = skb_peek(&sk->sk_async_wait_queue)) && 1282 (dma_async_is_complete(skb->dma_cookie, done, 1283 used) == DMA_SUCCESS)) { 1284 __skb_dequeue(&sk->sk_async_wait_queue); 1285 kfree_skb(skb); 1286 } 1287 } 1288 } while (wait); 1289 } 1290 #endif 1291 1292 static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1293 { 1294 struct sk_buff *skb; 1295 u32 offset; 1296 1297 skb_queue_walk(&sk->sk_receive_queue, skb) { 1298 offset = seq - TCP_SKB_CB(skb)->seq; 1299 if (tcp_hdr(skb)->syn) 1300 offset--; 1301 if (offset < skb->len || tcp_hdr(skb)->fin) { 1302 *off = offset; 1303 return skb; 1304 } 1305 } 1306 return NULL; 1307 } 1308 1309 /* 1310 * This routine provides an alternative to tcp_recvmsg() for routines 1311 * that would like to handle copying from skbuffs directly in 'sendfile' 1312 * fashion. 1313 * Note: 1314 * - It is assumed that the socket was locked by the caller. 1315 * - The routine does not block. 1316 * - At present, there is no support for reading OOB data 1317 * or for 'peeking' the socket using this routine 1318 * (although both would be easy to implement). 1319 */ 1320 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1321 sk_read_actor_t recv_actor) 1322 { 1323 struct sk_buff *skb; 1324 struct tcp_sock *tp = tcp_sk(sk); 1325 u32 seq = tp->copied_seq; 1326 u32 offset; 1327 int copied = 0; 1328 1329 if (sk->sk_state == TCP_LISTEN) 1330 return -ENOTCONN; 1331 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1332 if (offset < skb->len) { 1333 int used; 1334 size_t len; 1335 1336 len = skb->len - offset; 1337 /* Stop reading if we hit a patch of urgent data */ 1338 if (tp->urg_data) { 1339 u32 urg_offset = tp->urg_seq - seq; 1340 if (urg_offset < len) 1341 len = urg_offset; 1342 if (!len) 1343 break; 1344 } 1345 used = recv_actor(desc, skb, offset, len); 1346 if (used < 0) { 1347 if (!copied) 1348 copied = used; 1349 break; 1350 } else if (used <= len) { 1351 seq += used; 1352 copied += used; 1353 offset += used; 1354 } 1355 /* 1356 * If recv_actor drops the lock (e.g. TCP splice 1357 * receive) the skb pointer might be invalid when 1358 * getting here: tcp_collapse might have deleted it 1359 * while aggregating skbs from the socket queue. 1360 */ 1361 skb = tcp_recv_skb(sk, seq-1, &offset); 1362 if (!skb || (offset+1 != skb->len)) 1363 break; 1364 } 1365 if (tcp_hdr(skb)->fin) { 1366 sk_eat_skb(sk, skb, 0); 1367 ++seq; 1368 break; 1369 } 1370 sk_eat_skb(sk, skb, 0); 1371 if (!desc->count) 1372 break; 1373 tp->copied_seq = seq; 1374 } 1375 tp->copied_seq = seq; 1376 1377 tcp_rcv_space_adjust(sk); 1378 1379 /* Clean up data we have read: This will do ACK frames. */ 1380 if (copied > 0) 1381 tcp_cleanup_rbuf(sk, copied); 1382 return copied; 1383 } 1384 1385 /* 1386 * This routine copies from a sock struct into the user buffer. 1387 * 1388 * Technical note: in 2.3 we work on _locked_ socket, so that 1389 * tricks with *seq access order and skb->users are not required. 1390 * Probably, code can be easily improved even more. 1391 */ 1392 1393 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1394 size_t len, int nonblock, int flags, int *addr_len) 1395 { 1396 struct tcp_sock *tp = tcp_sk(sk); 1397 int copied = 0; 1398 u32 peek_seq; 1399 u32 *seq; 1400 unsigned long used; 1401 int err; 1402 int target; /* Read at least this many bytes */ 1403 long timeo; 1404 struct task_struct *user_recv = NULL; 1405 int copied_early = 0; 1406 struct sk_buff *skb; 1407 u32 urg_hole = 0; 1408 1409 lock_sock(sk); 1410 1411 TCP_CHECK_TIMER(sk); 1412 1413 err = -ENOTCONN; 1414 if (sk->sk_state == TCP_LISTEN) 1415 goto out; 1416 1417 timeo = sock_rcvtimeo(sk, nonblock); 1418 1419 /* Urgent data needs to be handled specially. */ 1420 if (flags & MSG_OOB) 1421 goto recv_urg; 1422 1423 seq = &tp->copied_seq; 1424 if (flags & MSG_PEEK) { 1425 peek_seq = tp->copied_seq; 1426 seq = &peek_seq; 1427 } 1428 1429 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1430 1431 #ifdef CONFIG_NET_DMA 1432 tp->ucopy.dma_chan = NULL; 1433 preempt_disable(); 1434 skb = skb_peek_tail(&sk->sk_receive_queue); 1435 { 1436 int available = 0; 1437 1438 if (skb) 1439 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); 1440 if ((available < target) && 1441 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && 1442 !sysctl_tcp_low_latency && 1443 dma_find_channel(DMA_MEMCPY)) { 1444 preempt_enable_no_resched(); 1445 tp->ucopy.pinned_list = 1446 dma_pin_iovec_pages(msg->msg_iov, len); 1447 } else { 1448 preempt_enable_no_resched(); 1449 } 1450 } 1451 #endif 1452 1453 do { 1454 u32 offset; 1455 1456 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1457 if (tp->urg_data && tp->urg_seq == *seq) { 1458 if (copied) 1459 break; 1460 if (signal_pending(current)) { 1461 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1462 break; 1463 } 1464 } 1465 1466 /* Next get a buffer. */ 1467 1468 skb_queue_walk(&sk->sk_receive_queue, skb) { 1469 /* Now that we have two receive queues this 1470 * shouldn't happen. 1471 */ 1472 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 1473 KERN_INFO "recvmsg bug: copied %X " 1474 "seq %X rcvnxt %X fl %X\n", *seq, 1475 TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 1476 flags)) 1477 break; 1478 1479 offset = *seq - TCP_SKB_CB(skb)->seq; 1480 if (tcp_hdr(skb)->syn) 1481 offset--; 1482 if (offset < skb->len) 1483 goto found_ok_skb; 1484 if (tcp_hdr(skb)->fin) 1485 goto found_fin_ok; 1486 WARN(!(flags & MSG_PEEK), KERN_INFO "recvmsg bug 2: " 1487 "copied %X seq %X rcvnxt %X fl %X\n", 1488 *seq, TCP_SKB_CB(skb)->seq, 1489 tp->rcv_nxt, flags); 1490 } 1491 1492 /* Well, if we have backlog, try to process it now yet. */ 1493 1494 if (copied >= target && !sk->sk_backlog.tail) 1495 break; 1496 1497 if (copied) { 1498 if (sk->sk_err || 1499 sk->sk_state == TCP_CLOSE || 1500 (sk->sk_shutdown & RCV_SHUTDOWN) || 1501 !timeo || 1502 signal_pending(current)) 1503 break; 1504 } else { 1505 if (sock_flag(sk, SOCK_DONE)) 1506 break; 1507 1508 if (sk->sk_err) { 1509 copied = sock_error(sk); 1510 break; 1511 } 1512 1513 if (sk->sk_shutdown & RCV_SHUTDOWN) 1514 break; 1515 1516 if (sk->sk_state == TCP_CLOSE) { 1517 if (!sock_flag(sk, SOCK_DONE)) { 1518 /* This occurs when user tries to read 1519 * from never connected socket. 1520 */ 1521 copied = -ENOTCONN; 1522 break; 1523 } 1524 break; 1525 } 1526 1527 if (!timeo) { 1528 copied = -EAGAIN; 1529 break; 1530 } 1531 1532 if (signal_pending(current)) { 1533 copied = sock_intr_errno(timeo); 1534 break; 1535 } 1536 } 1537 1538 tcp_cleanup_rbuf(sk, copied); 1539 1540 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { 1541 /* Install new reader */ 1542 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { 1543 user_recv = current; 1544 tp->ucopy.task = user_recv; 1545 tp->ucopy.iov = msg->msg_iov; 1546 } 1547 1548 tp->ucopy.len = len; 1549 1550 WARN_ON(tp->copied_seq != tp->rcv_nxt && 1551 !(flags & (MSG_PEEK | MSG_TRUNC))); 1552 1553 /* Ugly... If prequeue is not empty, we have to 1554 * process it before releasing socket, otherwise 1555 * order will be broken at second iteration. 1556 * More elegant solution is required!!! 1557 * 1558 * Look: we have the following (pseudo)queues: 1559 * 1560 * 1. packets in flight 1561 * 2. backlog 1562 * 3. prequeue 1563 * 4. receive_queue 1564 * 1565 * Each queue can be processed only if the next ones 1566 * are empty. At this point we have empty receive_queue. 1567 * But prequeue _can_ be not empty after 2nd iteration, 1568 * when we jumped to start of loop because backlog 1569 * processing added something to receive_queue. 1570 * We cannot release_sock(), because backlog contains 1571 * packets arrived _after_ prequeued ones. 1572 * 1573 * Shortly, algorithm is clear --- to process all 1574 * the queues in order. We could make it more directly, 1575 * requeueing packets from backlog to prequeue, if 1576 * is not empty. It is more elegant, but eats cycles, 1577 * unfortunately. 1578 */ 1579 if (!skb_queue_empty(&tp->ucopy.prequeue)) 1580 goto do_prequeue; 1581 1582 /* __ Set realtime policy in scheduler __ */ 1583 } 1584 1585 #ifdef CONFIG_NET_DMA 1586 if (tp->ucopy.dma_chan) 1587 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1588 #endif 1589 if (copied >= target) { 1590 /* Do not sleep, just process backlog. */ 1591 release_sock(sk); 1592 lock_sock(sk); 1593 } else 1594 sk_wait_data(sk, &timeo); 1595 1596 #ifdef CONFIG_NET_DMA 1597 tcp_service_net_dma(sk, false); /* Don't block */ 1598 tp->ucopy.wakeup = 0; 1599 #endif 1600 1601 if (user_recv) { 1602 int chunk; 1603 1604 /* __ Restore normal policy in scheduler __ */ 1605 1606 if ((chunk = len - tp->ucopy.len) != 0) { 1607 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); 1608 len -= chunk; 1609 copied += chunk; 1610 } 1611 1612 if (tp->rcv_nxt == tp->copied_seq && 1613 !skb_queue_empty(&tp->ucopy.prequeue)) { 1614 do_prequeue: 1615 tcp_prequeue_process(sk); 1616 1617 if ((chunk = len - tp->ucopy.len) != 0) { 1618 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1619 len -= chunk; 1620 copied += chunk; 1621 } 1622 } 1623 } 1624 if ((flags & MSG_PEEK) && 1625 (peek_seq - copied - urg_hole != tp->copied_seq)) { 1626 if (net_ratelimit()) 1627 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n", 1628 current->comm, task_pid_nr(current)); 1629 peek_seq = tp->copied_seq; 1630 } 1631 continue; 1632 1633 found_ok_skb: 1634 /* Ok so how much can we use? */ 1635 used = skb->len - offset; 1636 if (len < used) 1637 used = len; 1638 1639 /* Do we have urgent data here? */ 1640 if (tp->urg_data) { 1641 u32 urg_offset = tp->urg_seq - *seq; 1642 if (urg_offset < used) { 1643 if (!urg_offset) { 1644 if (!sock_flag(sk, SOCK_URGINLINE)) { 1645 ++*seq; 1646 urg_hole++; 1647 offset++; 1648 used--; 1649 if (!used) 1650 goto skip_copy; 1651 } 1652 } else 1653 used = urg_offset; 1654 } 1655 } 1656 1657 if (!(flags & MSG_TRUNC)) { 1658 #ifdef CONFIG_NET_DMA 1659 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1660 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); 1661 1662 if (tp->ucopy.dma_chan) { 1663 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( 1664 tp->ucopy.dma_chan, skb, offset, 1665 msg->msg_iov, used, 1666 tp->ucopy.pinned_list); 1667 1668 if (tp->ucopy.dma_cookie < 0) { 1669 1670 printk(KERN_ALERT "dma_cookie < 0\n"); 1671 1672 /* Exception. Bailout! */ 1673 if (!copied) 1674 copied = -EFAULT; 1675 break; 1676 } 1677 1678 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1679 1680 if ((offset + used) == skb->len) 1681 copied_early = 1; 1682 1683 } else 1684 #endif 1685 { 1686 err = skb_copy_datagram_iovec(skb, offset, 1687 msg->msg_iov, used); 1688 if (err) { 1689 /* Exception. Bailout! */ 1690 if (!copied) 1691 copied = -EFAULT; 1692 break; 1693 } 1694 } 1695 } 1696 1697 *seq += used; 1698 copied += used; 1699 len -= used; 1700 1701 tcp_rcv_space_adjust(sk); 1702 1703 skip_copy: 1704 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1705 tp->urg_data = 0; 1706 tcp_fast_path_check(sk); 1707 } 1708 if (used + offset < skb->len) 1709 continue; 1710 1711 if (tcp_hdr(skb)->fin) 1712 goto found_fin_ok; 1713 if (!(flags & MSG_PEEK)) { 1714 sk_eat_skb(sk, skb, copied_early); 1715 copied_early = 0; 1716 } 1717 continue; 1718 1719 found_fin_ok: 1720 /* Process the FIN. */ 1721 ++*seq; 1722 if (!(flags & MSG_PEEK)) { 1723 sk_eat_skb(sk, skb, copied_early); 1724 copied_early = 0; 1725 } 1726 break; 1727 } while (len > 0); 1728 1729 if (user_recv) { 1730 if (!skb_queue_empty(&tp->ucopy.prequeue)) { 1731 int chunk; 1732 1733 tp->ucopy.len = copied > 0 ? len : 0; 1734 1735 tcp_prequeue_process(sk); 1736 1737 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { 1738 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1739 len -= chunk; 1740 copied += chunk; 1741 } 1742 } 1743 1744 tp->ucopy.task = NULL; 1745 tp->ucopy.len = 0; 1746 } 1747 1748 #ifdef CONFIG_NET_DMA 1749 tcp_service_net_dma(sk, true); /* Wait for queue to drain */ 1750 tp->ucopy.dma_chan = NULL; 1751 1752 if (tp->ucopy.pinned_list) { 1753 dma_unpin_iovec_pages(tp->ucopy.pinned_list); 1754 tp->ucopy.pinned_list = NULL; 1755 } 1756 #endif 1757 1758 /* According to UNIX98, msg_name/msg_namelen are ignored 1759 * on connected socket. I was just happy when found this 8) --ANK 1760 */ 1761 1762 /* Clean up data we have read: This will do ACK frames. */ 1763 tcp_cleanup_rbuf(sk, copied); 1764 1765 TCP_CHECK_TIMER(sk); 1766 release_sock(sk); 1767 return copied; 1768 1769 out: 1770 TCP_CHECK_TIMER(sk); 1771 release_sock(sk); 1772 return err; 1773 1774 recv_urg: 1775 err = tcp_recv_urg(sk, msg, len, flags); 1776 goto out; 1777 } 1778 1779 void tcp_set_state(struct sock *sk, int state) 1780 { 1781 int oldstate = sk->sk_state; 1782 1783 switch (state) { 1784 case TCP_ESTABLISHED: 1785 if (oldstate != TCP_ESTABLISHED) 1786 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1787 break; 1788 1789 case TCP_CLOSE: 1790 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 1791 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 1792 1793 sk->sk_prot->unhash(sk); 1794 if (inet_csk(sk)->icsk_bind_hash && 1795 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1796 inet_put_port(sk); 1797 /* fall through */ 1798 default: 1799 if (oldstate == TCP_ESTABLISHED) 1800 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1801 } 1802 1803 /* Change state AFTER socket is unhashed to avoid closed 1804 * socket sitting in hash tables. 1805 */ 1806 sk->sk_state = state; 1807 1808 #ifdef STATE_TRACE 1809 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); 1810 #endif 1811 } 1812 EXPORT_SYMBOL_GPL(tcp_set_state); 1813 1814 /* 1815 * State processing on a close. This implements the state shift for 1816 * sending our FIN frame. Note that we only send a FIN for some 1817 * states. A shutdown() may have already sent the FIN, or we may be 1818 * closed. 1819 */ 1820 1821 static const unsigned char new_state[16] = { 1822 /* current state: new state: action: */ 1823 /* (Invalid) */ TCP_CLOSE, 1824 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1825 /* TCP_SYN_SENT */ TCP_CLOSE, 1826 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1827 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, 1828 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, 1829 /* TCP_TIME_WAIT */ TCP_CLOSE, 1830 /* TCP_CLOSE */ TCP_CLOSE, 1831 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, 1832 /* TCP_LAST_ACK */ TCP_LAST_ACK, 1833 /* TCP_LISTEN */ TCP_CLOSE, 1834 /* TCP_CLOSING */ TCP_CLOSING, 1835 }; 1836 1837 static int tcp_close_state(struct sock *sk) 1838 { 1839 int next = (int)new_state[sk->sk_state]; 1840 int ns = next & TCP_STATE_MASK; 1841 1842 tcp_set_state(sk, ns); 1843 1844 return next & TCP_ACTION_FIN; 1845 } 1846 1847 /* 1848 * Shutdown the sending side of a connection. Much like close except 1849 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 1850 */ 1851 1852 void tcp_shutdown(struct sock *sk, int how) 1853 { 1854 /* We need to grab some memory, and put together a FIN, 1855 * and then put it into the queue to be sent. 1856 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 1857 */ 1858 if (!(how & SEND_SHUTDOWN)) 1859 return; 1860 1861 /* If we've already sent a FIN, or it's a closed state, skip this. */ 1862 if ((1 << sk->sk_state) & 1863 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 1864 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 1865 /* Clear out any half completed packets. FIN if needed. */ 1866 if (tcp_close_state(sk)) 1867 tcp_send_fin(sk); 1868 } 1869 } 1870 1871 void tcp_close(struct sock *sk, long timeout) 1872 { 1873 struct sk_buff *skb; 1874 int data_was_unread = 0; 1875 int state; 1876 1877 lock_sock(sk); 1878 sk->sk_shutdown = SHUTDOWN_MASK; 1879 1880 if (sk->sk_state == TCP_LISTEN) { 1881 tcp_set_state(sk, TCP_CLOSE); 1882 1883 /* Special case. */ 1884 inet_csk_listen_stop(sk); 1885 1886 goto adjudge_to_death; 1887 } 1888 1889 /* We need to flush the recv. buffs. We do this only on the 1890 * descriptor close, not protocol-sourced closes, because the 1891 * reader process may not have drained the data yet! 1892 */ 1893 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1894 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - 1895 tcp_hdr(skb)->fin; 1896 data_was_unread += len; 1897 __kfree_skb(skb); 1898 } 1899 1900 sk_mem_reclaim(sk); 1901 1902 /* As outlined in RFC 2525, section 2.17, we send a RST here because 1903 * data was lost. To witness the awful effects of the old behavior of 1904 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 1905 * GET in an FTP client, suspend the process, wait for the client to 1906 * advertise a zero window, then kill -9 the FTP client, wheee... 1907 * Note: timeout is always zero in such a case. 1908 */ 1909 if (data_was_unread) { 1910 /* Unread data was tossed, zap the connection. */ 1911 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 1912 tcp_set_state(sk, TCP_CLOSE); 1913 tcp_send_active_reset(sk, sk->sk_allocation); 1914 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1915 /* Check zero linger _after_ checking for unread data. */ 1916 sk->sk_prot->disconnect(sk, 0); 1917 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 1918 } else if (tcp_close_state(sk)) { 1919 /* We FIN if the application ate all the data before 1920 * zapping the connection. 1921 */ 1922 1923 /* RED-PEN. Formally speaking, we have broken TCP state 1924 * machine. State transitions: 1925 * 1926 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 1927 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 1928 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 1929 * 1930 * are legal only when FIN has been sent (i.e. in window), 1931 * rather than queued out of window. Purists blame. 1932 * 1933 * F.e. "RFC state" is ESTABLISHED, 1934 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 1935 * 1936 * The visible declinations are that sometimes 1937 * we enter time-wait state, when it is not required really 1938 * (harmless), do not send active resets, when they are 1939 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 1940 * they look as CLOSING or LAST_ACK for Linux) 1941 * Probably, I missed some more holelets. 1942 * --ANK 1943 */ 1944 tcp_send_fin(sk); 1945 } 1946 1947 sk_stream_wait_close(sk, timeout); 1948 1949 adjudge_to_death: 1950 state = sk->sk_state; 1951 sock_hold(sk); 1952 sock_orphan(sk); 1953 1954 /* It is the last release_sock in its life. It will remove backlog. */ 1955 release_sock(sk); 1956 1957 1958 /* Now socket is owned by kernel and we acquire BH lock 1959 to finish close. No need to check for user refs. 1960 */ 1961 local_bh_disable(); 1962 bh_lock_sock(sk); 1963 WARN_ON(sock_owned_by_user(sk)); 1964 1965 percpu_counter_inc(sk->sk_prot->orphan_count); 1966 1967 /* Have we already been destroyed by a softirq or backlog? */ 1968 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 1969 goto out; 1970 1971 /* This is a (useful) BSD violating of the RFC. There is a 1972 * problem with TCP as specified in that the other end could 1973 * keep a socket open forever with no application left this end. 1974 * We use a 3 minute timeout (about the same as BSD) then kill 1975 * our end. If they send after that then tough - BUT: long enough 1976 * that we won't make the old 4*rto = almost no time - whoops 1977 * reset mistake. 1978 * 1979 * Nope, it was not mistake. It is really desired behaviour 1980 * f.e. on http servers, when such sockets are useless, but 1981 * consume significant resources. Let's do it with special 1982 * linger2 option. --ANK 1983 */ 1984 1985 if (sk->sk_state == TCP_FIN_WAIT2) { 1986 struct tcp_sock *tp = tcp_sk(sk); 1987 if (tp->linger2 < 0) { 1988 tcp_set_state(sk, TCP_CLOSE); 1989 tcp_send_active_reset(sk, GFP_ATOMIC); 1990 NET_INC_STATS_BH(sock_net(sk), 1991 LINUX_MIB_TCPABORTONLINGER); 1992 } else { 1993 const int tmo = tcp_fin_time(sk); 1994 1995 if (tmo > TCP_TIMEWAIT_LEN) { 1996 inet_csk_reset_keepalive_timer(sk, 1997 tmo - TCP_TIMEWAIT_LEN); 1998 } else { 1999 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 2000 goto out; 2001 } 2002 } 2003 } 2004 if (sk->sk_state != TCP_CLOSE) { 2005 int orphan_count = percpu_counter_read_positive( 2006 sk->sk_prot->orphan_count); 2007 2008 sk_mem_reclaim(sk); 2009 if (tcp_too_many_orphans(sk, orphan_count)) { 2010 if (net_ratelimit()) 2011 printk(KERN_INFO "TCP: too many of orphaned " 2012 "sockets\n"); 2013 tcp_set_state(sk, TCP_CLOSE); 2014 tcp_send_active_reset(sk, GFP_ATOMIC); 2015 NET_INC_STATS_BH(sock_net(sk), 2016 LINUX_MIB_TCPABORTONMEMORY); 2017 } 2018 } 2019 2020 if (sk->sk_state == TCP_CLOSE) 2021 inet_csk_destroy_sock(sk); 2022 /* Otherwise, socket is reprieved until protocol close. */ 2023 2024 out: 2025 bh_unlock_sock(sk); 2026 local_bh_enable(); 2027 sock_put(sk); 2028 } 2029 2030 /* These states need RST on ABORT according to RFC793 */ 2031 2032 static inline int tcp_need_reset(int state) 2033 { 2034 return (1 << state) & 2035 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2036 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2037 } 2038 2039 int tcp_disconnect(struct sock *sk, int flags) 2040 { 2041 struct inet_sock *inet = inet_sk(sk); 2042 struct inet_connection_sock *icsk = inet_csk(sk); 2043 struct tcp_sock *tp = tcp_sk(sk); 2044 int err = 0; 2045 int old_state = sk->sk_state; 2046 2047 if (old_state != TCP_CLOSE) 2048 tcp_set_state(sk, TCP_CLOSE); 2049 2050 /* ABORT function of RFC793 */ 2051 if (old_state == TCP_LISTEN) { 2052 inet_csk_listen_stop(sk); 2053 } else if (tcp_need_reset(old_state) || 2054 (tp->snd_nxt != tp->write_seq && 2055 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2056 /* The last check adjusts for discrepancy of Linux wrt. RFC 2057 * states 2058 */ 2059 tcp_send_active_reset(sk, gfp_any()); 2060 sk->sk_err = ECONNRESET; 2061 } else if (old_state == TCP_SYN_SENT) 2062 sk->sk_err = ECONNRESET; 2063 2064 tcp_clear_xmit_timers(sk); 2065 __skb_queue_purge(&sk->sk_receive_queue); 2066 tcp_write_queue_purge(sk); 2067 __skb_queue_purge(&tp->out_of_order_queue); 2068 #ifdef CONFIG_NET_DMA 2069 __skb_queue_purge(&sk->sk_async_wait_queue); 2070 #endif 2071 2072 inet->inet_dport = 0; 2073 2074 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2075 inet_reset_saddr(sk); 2076 2077 sk->sk_shutdown = 0; 2078 sock_reset_flag(sk, SOCK_DONE); 2079 tp->srtt = 0; 2080 if ((tp->write_seq += tp->max_window + 2) == 0) 2081 tp->write_seq = 1; 2082 icsk->icsk_backoff = 0; 2083 tp->snd_cwnd = 2; 2084 icsk->icsk_probes_out = 0; 2085 tp->packets_out = 0; 2086 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2087 tp->snd_cwnd_cnt = 0; 2088 tp->bytes_acked = 0; 2089 tp->window_clamp = 0; 2090 tcp_set_ca_state(sk, TCP_CA_Open); 2091 tcp_clear_retrans(tp); 2092 inet_csk_delack_init(sk); 2093 tcp_init_send_head(sk); 2094 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2095 __sk_dst_reset(sk); 2096 2097 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2098 2099 sk->sk_error_report(sk); 2100 return err; 2101 } 2102 2103 /* 2104 * Socket option code for TCP. 2105 */ 2106 static int do_tcp_setsockopt(struct sock *sk, int level, 2107 int optname, char __user *optval, unsigned int optlen) 2108 { 2109 struct tcp_sock *tp = tcp_sk(sk); 2110 struct inet_connection_sock *icsk = inet_csk(sk); 2111 int val; 2112 int err = 0; 2113 2114 /* These are data/string values, all the others are ints */ 2115 switch (optname) { 2116 case TCP_CONGESTION: { 2117 char name[TCP_CA_NAME_MAX]; 2118 2119 if (optlen < 1) 2120 return -EINVAL; 2121 2122 val = strncpy_from_user(name, optval, 2123 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2124 if (val < 0) 2125 return -EFAULT; 2126 name[val] = 0; 2127 2128 lock_sock(sk); 2129 err = tcp_set_congestion_control(sk, name); 2130 release_sock(sk); 2131 return err; 2132 } 2133 case TCP_COOKIE_TRANSACTIONS: { 2134 struct tcp_cookie_transactions ctd; 2135 struct tcp_cookie_values *cvp = NULL; 2136 2137 if (sizeof(ctd) > optlen) 2138 return -EINVAL; 2139 if (copy_from_user(&ctd, optval, sizeof(ctd))) 2140 return -EFAULT; 2141 2142 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) || 2143 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED) 2144 return -EINVAL; 2145 2146 if (ctd.tcpct_cookie_desired == 0) { 2147 /* default to global value */ 2148 } else if ((0x1 & ctd.tcpct_cookie_desired) || 2149 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX || 2150 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) { 2151 return -EINVAL; 2152 } 2153 2154 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) { 2155 /* Supercedes all other values */ 2156 lock_sock(sk); 2157 if (tp->cookie_values != NULL) { 2158 kref_put(&tp->cookie_values->kref, 2159 tcp_cookie_values_release); 2160 tp->cookie_values = NULL; 2161 } 2162 tp->rx_opt.cookie_in_always = 0; /* false */ 2163 tp->rx_opt.cookie_out_never = 1; /* true */ 2164 release_sock(sk); 2165 return err; 2166 } 2167 2168 /* Allocate ancillary memory before locking. 2169 */ 2170 if (ctd.tcpct_used > 0 || 2171 (tp->cookie_values == NULL && 2172 (sysctl_tcp_cookie_size > 0 || 2173 ctd.tcpct_cookie_desired > 0 || 2174 ctd.tcpct_s_data_desired > 0))) { 2175 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used, 2176 GFP_KERNEL); 2177 if (cvp == NULL) 2178 return -ENOMEM; 2179 } 2180 lock_sock(sk); 2181 tp->rx_opt.cookie_in_always = 2182 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags); 2183 tp->rx_opt.cookie_out_never = 0; /* false */ 2184 2185 if (tp->cookie_values != NULL) { 2186 if (cvp != NULL) { 2187 /* Changed values are recorded by a changed 2188 * pointer, ensuring the cookie will differ, 2189 * without separately hashing each value later. 2190 */ 2191 kref_put(&tp->cookie_values->kref, 2192 tcp_cookie_values_release); 2193 kref_init(&cvp->kref); 2194 tp->cookie_values = cvp; 2195 } else { 2196 cvp = tp->cookie_values; 2197 } 2198 } 2199 if (cvp != NULL) { 2200 cvp->cookie_desired = ctd.tcpct_cookie_desired; 2201 2202 if (ctd.tcpct_used > 0) { 2203 memcpy(cvp->s_data_payload, ctd.tcpct_value, 2204 ctd.tcpct_used); 2205 cvp->s_data_desired = ctd.tcpct_used; 2206 cvp->s_data_constant = 1; /* true */ 2207 } else { 2208 /* No constant payload data. */ 2209 cvp->s_data_desired = ctd.tcpct_s_data_desired; 2210 cvp->s_data_constant = 0; /* false */ 2211 } 2212 } 2213 release_sock(sk); 2214 return err; 2215 } 2216 default: 2217 /* fallthru */ 2218 break; 2219 } 2220 2221 if (optlen < sizeof(int)) 2222 return -EINVAL; 2223 2224 if (get_user(val, (int __user *)optval)) 2225 return -EFAULT; 2226 2227 lock_sock(sk); 2228 2229 switch (optname) { 2230 case TCP_MAXSEG: 2231 /* Values greater than interface MTU won't take effect. However 2232 * at the point when this call is done we typically don't yet 2233 * know which interface is going to be used */ 2234 if (val < 8 || val > MAX_TCP_WINDOW) { 2235 err = -EINVAL; 2236 break; 2237 } 2238 tp->rx_opt.user_mss = val; 2239 break; 2240 2241 case TCP_NODELAY: 2242 if (val) { 2243 /* TCP_NODELAY is weaker than TCP_CORK, so that 2244 * this option on corked socket is remembered, but 2245 * it is not activated until cork is cleared. 2246 * 2247 * However, when TCP_NODELAY is set we make 2248 * an explicit push, which overrides even TCP_CORK 2249 * for currently queued segments. 2250 */ 2251 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2252 tcp_push_pending_frames(sk); 2253 } else { 2254 tp->nonagle &= ~TCP_NAGLE_OFF; 2255 } 2256 break; 2257 2258 case TCP_THIN_LINEAR_TIMEOUTS: 2259 if (val < 0 || val > 1) 2260 err = -EINVAL; 2261 else 2262 tp->thin_lto = val; 2263 break; 2264 2265 case TCP_THIN_DUPACK: 2266 if (val < 0 || val > 1) 2267 err = -EINVAL; 2268 else 2269 tp->thin_dupack = val; 2270 break; 2271 2272 case TCP_CORK: 2273 /* When set indicates to always queue non-full frames. 2274 * Later the user clears this option and we transmit 2275 * any pending partial frames in the queue. This is 2276 * meant to be used alongside sendfile() to get properly 2277 * filled frames when the user (for example) must write 2278 * out headers with a write() call first and then use 2279 * sendfile to send out the data parts. 2280 * 2281 * TCP_CORK can be set together with TCP_NODELAY and it is 2282 * stronger than TCP_NODELAY. 2283 */ 2284 if (val) { 2285 tp->nonagle |= TCP_NAGLE_CORK; 2286 } else { 2287 tp->nonagle &= ~TCP_NAGLE_CORK; 2288 if (tp->nonagle&TCP_NAGLE_OFF) 2289 tp->nonagle |= TCP_NAGLE_PUSH; 2290 tcp_push_pending_frames(sk); 2291 } 2292 break; 2293 2294 case TCP_KEEPIDLE: 2295 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2296 err = -EINVAL; 2297 else { 2298 tp->keepalive_time = val * HZ; 2299 if (sock_flag(sk, SOCK_KEEPOPEN) && 2300 !((1 << sk->sk_state) & 2301 (TCPF_CLOSE | TCPF_LISTEN))) { 2302 u32 elapsed = keepalive_time_elapsed(tp); 2303 if (tp->keepalive_time > elapsed) 2304 elapsed = tp->keepalive_time - elapsed; 2305 else 2306 elapsed = 0; 2307 inet_csk_reset_keepalive_timer(sk, elapsed); 2308 } 2309 } 2310 break; 2311 case TCP_KEEPINTVL: 2312 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2313 err = -EINVAL; 2314 else 2315 tp->keepalive_intvl = val * HZ; 2316 break; 2317 case TCP_KEEPCNT: 2318 if (val < 1 || val > MAX_TCP_KEEPCNT) 2319 err = -EINVAL; 2320 else 2321 tp->keepalive_probes = val; 2322 break; 2323 case TCP_SYNCNT: 2324 if (val < 1 || val > MAX_TCP_SYNCNT) 2325 err = -EINVAL; 2326 else 2327 icsk->icsk_syn_retries = val; 2328 break; 2329 2330 case TCP_LINGER2: 2331 if (val < 0) 2332 tp->linger2 = -1; 2333 else if (val > sysctl_tcp_fin_timeout / HZ) 2334 tp->linger2 = 0; 2335 else 2336 tp->linger2 = val * HZ; 2337 break; 2338 2339 case TCP_DEFER_ACCEPT: 2340 /* Translate value in seconds to number of retransmits */ 2341 icsk->icsk_accept_queue.rskq_defer_accept = 2342 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2343 TCP_RTO_MAX / HZ); 2344 break; 2345 2346 case TCP_WINDOW_CLAMP: 2347 if (!val) { 2348 if (sk->sk_state != TCP_CLOSE) { 2349 err = -EINVAL; 2350 break; 2351 } 2352 tp->window_clamp = 0; 2353 } else 2354 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2355 SOCK_MIN_RCVBUF / 2 : val; 2356 break; 2357 2358 case TCP_QUICKACK: 2359 if (!val) { 2360 icsk->icsk_ack.pingpong = 1; 2361 } else { 2362 icsk->icsk_ack.pingpong = 0; 2363 if ((1 << sk->sk_state) & 2364 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2365 inet_csk_ack_scheduled(sk)) { 2366 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2367 tcp_cleanup_rbuf(sk, 1); 2368 if (!(val & 1)) 2369 icsk->icsk_ack.pingpong = 1; 2370 } 2371 } 2372 break; 2373 2374 #ifdef CONFIG_TCP_MD5SIG 2375 case TCP_MD5SIG: 2376 /* Read the IP->Key mappings from userspace */ 2377 err = tp->af_specific->md5_parse(sk, optval, optlen); 2378 break; 2379 #endif 2380 2381 default: 2382 err = -ENOPROTOOPT; 2383 break; 2384 } 2385 2386 release_sock(sk); 2387 return err; 2388 } 2389 2390 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2391 unsigned int optlen) 2392 { 2393 struct inet_connection_sock *icsk = inet_csk(sk); 2394 2395 if (level != SOL_TCP) 2396 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2397 optval, optlen); 2398 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2399 } 2400 2401 #ifdef CONFIG_COMPAT 2402 int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2403 char __user *optval, unsigned int optlen) 2404 { 2405 if (level != SOL_TCP) 2406 return inet_csk_compat_setsockopt(sk, level, optname, 2407 optval, optlen); 2408 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2409 } 2410 2411 EXPORT_SYMBOL(compat_tcp_setsockopt); 2412 #endif 2413 2414 /* Return information about state of tcp endpoint in API format. */ 2415 void tcp_get_info(struct sock *sk, struct tcp_info *info) 2416 { 2417 struct tcp_sock *tp = tcp_sk(sk); 2418 const struct inet_connection_sock *icsk = inet_csk(sk); 2419 u32 now = tcp_time_stamp; 2420 2421 memset(info, 0, sizeof(*info)); 2422 2423 info->tcpi_state = sk->sk_state; 2424 info->tcpi_ca_state = icsk->icsk_ca_state; 2425 info->tcpi_retransmits = icsk->icsk_retransmits; 2426 info->tcpi_probes = icsk->icsk_probes_out; 2427 info->tcpi_backoff = icsk->icsk_backoff; 2428 2429 if (tp->rx_opt.tstamp_ok) 2430 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2431 if (tcp_is_sack(tp)) 2432 info->tcpi_options |= TCPI_OPT_SACK; 2433 if (tp->rx_opt.wscale_ok) { 2434 info->tcpi_options |= TCPI_OPT_WSCALE; 2435 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2436 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2437 } 2438 2439 if (tp->ecn_flags&TCP_ECN_OK) 2440 info->tcpi_options |= TCPI_OPT_ECN; 2441 2442 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2443 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2444 info->tcpi_snd_mss = tp->mss_cache; 2445 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2446 2447 if (sk->sk_state == TCP_LISTEN) { 2448 info->tcpi_unacked = sk->sk_ack_backlog; 2449 info->tcpi_sacked = sk->sk_max_ack_backlog; 2450 } else { 2451 info->tcpi_unacked = tp->packets_out; 2452 info->tcpi_sacked = tp->sacked_out; 2453 } 2454 info->tcpi_lost = tp->lost_out; 2455 info->tcpi_retrans = tp->retrans_out; 2456 info->tcpi_fackets = tp->fackets_out; 2457 2458 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2459 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2460 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2461 2462 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2463 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2464 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3; 2465 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2; 2466 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2467 info->tcpi_snd_cwnd = tp->snd_cwnd; 2468 info->tcpi_advmss = tp->advmss; 2469 info->tcpi_reordering = tp->reordering; 2470 2471 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; 2472 info->tcpi_rcv_space = tp->rcvq_space.space; 2473 2474 info->tcpi_total_retrans = tp->total_retrans; 2475 } 2476 2477 EXPORT_SYMBOL_GPL(tcp_get_info); 2478 2479 static int do_tcp_getsockopt(struct sock *sk, int level, 2480 int optname, char __user *optval, int __user *optlen) 2481 { 2482 struct inet_connection_sock *icsk = inet_csk(sk); 2483 struct tcp_sock *tp = tcp_sk(sk); 2484 int val, len; 2485 2486 if (get_user(len, optlen)) 2487 return -EFAULT; 2488 2489 len = min_t(unsigned int, len, sizeof(int)); 2490 2491 if (len < 0) 2492 return -EINVAL; 2493 2494 switch (optname) { 2495 case TCP_MAXSEG: 2496 val = tp->mss_cache; 2497 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2498 val = tp->rx_opt.user_mss; 2499 break; 2500 case TCP_NODELAY: 2501 val = !!(tp->nonagle&TCP_NAGLE_OFF); 2502 break; 2503 case TCP_CORK: 2504 val = !!(tp->nonagle&TCP_NAGLE_CORK); 2505 break; 2506 case TCP_KEEPIDLE: 2507 val = keepalive_time_when(tp) / HZ; 2508 break; 2509 case TCP_KEEPINTVL: 2510 val = keepalive_intvl_when(tp) / HZ; 2511 break; 2512 case TCP_KEEPCNT: 2513 val = keepalive_probes(tp); 2514 break; 2515 case TCP_SYNCNT: 2516 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 2517 break; 2518 case TCP_LINGER2: 2519 val = tp->linger2; 2520 if (val >= 0) 2521 val = (val ? : sysctl_tcp_fin_timeout) / HZ; 2522 break; 2523 case TCP_DEFER_ACCEPT: 2524 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 2525 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 2526 break; 2527 case TCP_WINDOW_CLAMP: 2528 val = tp->window_clamp; 2529 break; 2530 case TCP_INFO: { 2531 struct tcp_info info; 2532 2533 if (get_user(len, optlen)) 2534 return -EFAULT; 2535 2536 tcp_get_info(sk, &info); 2537 2538 len = min_t(unsigned int, len, sizeof(info)); 2539 if (put_user(len, optlen)) 2540 return -EFAULT; 2541 if (copy_to_user(optval, &info, len)) 2542 return -EFAULT; 2543 return 0; 2544 } 2545 case TCP_QUICKACK: 2546 val = !icsk->icsk_ack.pingpong; 2547 break; 2548 2549 case TCP_CONGESTION: 2550 if (get_user(len, optlen)) 2551 return -EFAULT; 2552 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 2553 if (put_user(len, optlen)) 2554 return -EFAULT; 2555 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 2556 return -EFAULT; 2557 return 0; 2558 2559 case TCP_COOKIE_TRANSACTIONS: { 2560 struct tcp_cookie_transactions ctd; 2561 struct tcp_cookie_values *cvp = tp->cookie_values; 2562 2563 if (get_user(len, optlen)) 2564 return -EFAULT; 2565 if (len < sizeof(ctd)) 2566 return -EINVAL; 2567 2568 memset(&ctd, 0, sizeof(ctd)); 2569 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ? 2570 TCP_COOKIE_IN_ALWAYS : 0) 2571 | (tp->rx_opt.cookie_out_never ? 2572 TCP_COOKIE_OUT_NEVER : 0); 2573 2574 if (cvp != NULL) { 2575 ctd.tcpct_flags |= (cvp->s_data_in ? 2576 TCP_S_DATA_IN : 0) 2577 | (cvp->s_data_out ? 2578 TCP_S_DATA_OUT : 0); 2579 2580 ctd.tcpct_cookie_desired = cvp->cookie_desired; 2581 ctd.tcpct_s_data_desired = cvp->s_data_desired; 2582 2583 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0], 2584 cvp->cookie_pair_size); 2585 ctd.tcpct_used = cvp->cookie_pair_size; 2586 } 2587 2588 if (put_user(sizeof(ctd), optlen)) 2589 return -EFAULT; 2590 if (copy_to_user(optval, &ctd, sizeof(ctd))) 2591 return -EFAULT; 2592 return 0; 2593 } 2594 default: 2595 return -ENOPROTOOPT; 2596 } 2597 2598 if (put_user(len, optlen)) 2599 return -EFAULT; 2600 if (copy_to_user(optval, &val, len)) 2601 return -EFAULT; 2602 return 0; 2603 } 2604 2605 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 2606 int __user *optlen) 2607 { 2608 struct inet_connection_sock *icsk = inet_csk(sk); 2609 2610 if (level != SOL_TCP) 2611 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 2612 optval, optlen); 2613 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2614 } 2615 2616 #ifdef CONFIG_COMPAT 2617 int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 2618 char __user *optval, int __user *optlen) 2619 { 2620 if (level != SOL_TCP) 2621 return inet_csk_compat_getsockopt(sk, level, optname, 2622 optval, optlen); 2623 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2624 } 2625 2626 EXPORT_SYMBOL(compat_tcp_getsockopt); 2627 #endif 2628 2629 struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features) 2630 { 2631 struct sk_buff *segs = ERR_PTR(-EINVAL); 2632 struct tcphdr *th; 2633 unsigned thlen; 2634 unsigned int seq; 2635 __be32 delta; 2636 unsigned int oldlen; 2637 unsigned int mss; 2638 2639 if (!pskb_may_pull(skb, sizeof(*th))) 2640 goto out; 2641 2642 th = tcp_hdr(skb); 2643 thlen = th->doff * 4; 2644 if (thlen < sizeof(*th)) 2645 goto out; 2646 2647 if (!pskb_may_pull(skb, thlen)) 2648 goto out; 2649 2650 oldlen = (u16)~skb->len; 2651 __skb_pull(skb, thlen); 2652 2653 mss = skb_shinfo(skb)->gso_size; 2654 if (unlikely(skb->len <= mss)) 2655 goto out; 2656 2657 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2658 /* Packet is from an untrusted source, reset gso_segs. */ 2659 int type = skb_shinfo(skb)->gso_type; 2660 2661 if (unlikely(type & 2662 ~(SKB_GSO_TCPV4 | 2663 SKB_GSO_DODGY | 2664 SKB_GSO_TCP_ECN | 2665 SKB_GSO_TCPV6 | 2666 0) || 2667 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))) 2668 goto out; 2669 2670 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2671 2672 segs = NULL; 2673 goto out; 2674 } 2675 2676 segs = skb_segment(skb, features); 2677 if (IS_ERR(segs)) 2678 goto out; 2679 2680 delta = htonl(oldlen + (thlen + mss)); 2681 2682 skb = segs; 2683 th = tcp_hdr(skb); 2684 seq = ntohl(th->seq); 2685 2686 do { 2687 th->fin = th->psh = 0; 2688 2689 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2690 (__force u32)delta)); 2691 if (skb->ip_summed != CHECKSUM_PARTIAL) 2692 th->check = 2693 csum_fold(csum_partial(skb_transport_header(skb), 2694 thlen, skb->csum)); 2695 2696 seq += mss; 2697 skb = skb->next; 2698 th = tcp_hdr(skb); 2699 2700 th->seq = htonl(seq); 2701 th->cwr = 0; 2702 } while (skb->next); 2703 2704 delta = htonl(oldlen + (skb->tail - skb->transport_header) + 2705 skb->data_len); 2706 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2707 (__force u32)delta)); 2708 if (skb->ip_summed != CHECKSUM_PARTIAL) 2709 th->check = csum_fold(csum_partial(skb_transport_header(skb), 2710 thlen, skb->csum)); 2711 2712 out: 2713 return segs; 2714 } 2715 EXPORT_SYMBOL(tcp_tso_segment); 2716 2717 struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) 2718 { 2719 struct sk_buff **pp = NULL; 2720 struct sk_buff *p; 2721 struct tcphdr *th; 2722 struct tcphdr *th2; 2723 unsigned int len; 2724 unsigned int thlen; 2725 __be32 flags; 2726 unsigned int mss = 1; 2727 unsigned int hlen; 2728 unsigned int off; 2729 int flush = 1; 2730 int i; 2731 2732 off = skb_gro_offset(skb); 2733 hlen = off + sizeof(*th); 2734 th = skb_gro_header_fast(skb, off); 2735 if (skb_gro_header_hard(skb, hlen)) { 2736 th = skb_gro_header_slow(skb, hlen, off); 2737 if (unlikely(!th)) 2738 goto out; 2739 } 2740 2741 thlen = th->doff * 4; 2742 if (thlen < sizeof(*th)) 2743 goto out; 2744 2745 hlen = off + thlen; 2746 if (skb_gro_header_hard(skb, hlen)) { 2747 th = skb_gro_header_slow(skb, hlen, off); 2748 if (unlikely(!th)) 2749 goto out; 2750 } 2751 2752 skb_gro_pull(skb, thlen); 2753 2754 len = skb_gro_len(skb); 2755 flags = tcp_flag_word(th); 2756 2757 for (; (p = *head); head = &p->next) { 2758 if (!NAPI_GRO_CB(p)->same_flow) 2759 continue; 2760 2761 th2 = tcp_hdr(p); 2762 2763 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) { 2764 NAPI_GRO_CB(p)->same_flow = 0; 2765 continue; 2766 } 2767 2768 goto found; 2769 } 2770 2771 goto out_check_final; 2772 2773 found: 2774 flush = NAPI_GRO_CB(p)->flush; 2775 flush |= (__force int)(flags & TCP_FLAG_CWR); 2776 flush |= (__force int)((flags ^ tcp_flag_word(th2)) & 2777 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH)); 2778 flush |= (__force int)(th->ack_seq ^ th2->ack_seq); 2779 for (i = sizeof(*th); i < thlen; i += 4) 2780 flush |= *(u32 *)((u8 *)th + i) ^ 2781 *(u32 *)((u8 *)th2 + i); 2782 2783 mss = skb_shinfo(p)->gso_size; 2784 2785 flush |= (len - 1) >= mss; 2786 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); 2787 2788 if (flush || skb_gro_receive(head, skb)) { 2789 mss = 1; 2790 goto out_check_final; 2791 } 2792 2793 p = *head; 2794 th2 = tcp_hdr(p); 2795 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); 2796 2797 out_check_final: 2798 flush = len < mss; 2799 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH | 2800 TCP_FLAG_RST | TCP_FLAG_SYN | 2801 TCP_FLAG_FIN)); 2802 2803 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush)) 2804 pp = head; 2805 2806 out: 2807 NAPI_GRO_CB(skb)->flush |= flush; 2808 2809 return pp; 2810 } 2811 EXPORT_SYMBOL(tcp_gro_receive); 2812 2813 int tcp_gro_complete(struct sk_buff *skb) 2814 { 2815 struct tcphdr *th = tcp_hdr(skb); 2816 2817 skb->csum_start = skb_transport_header(skb) - skb->head; 2818 skb->csum_offset = offsetof(struct tcphdr, check); 2819 skb->ip_summed = CHECKSUM_PARTIAL; 2820 2821 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 2822 2823 if (th->cwr) 2824 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 2825 2826 return 0; 2827 } 2828 EXPORT_SYMBOL(tcp_gro_complete); 2829 2830 #ifdef CONFIG_TCP_MD5SIG 2831 static unsigned long tcp_md5sig_users; 2832 static struct tcp_md5sig_pool * __percpu *tcp_md5sig_pool; 2833 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock); 2834 2835 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool * __percpu *pool) 2836 { 2837 int cpu; 2838 for_each_possible_cpu(cpu) { 2839 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu); 2840 if (p) { 2841 if (p->md5_desc.tfm) 2842 crypto_free_hash(p->md5_desc.tfm); 2843 kfree(p); 2844 } 2845 } 2846 free_percpu(pool); 2847 } 2848 2849 void tcp_free_md5sig_pool(void) 2850 { 2851 struct tcp_md5sig_pool * __percpu *pool = NULL; 2852 2853 spin_lock_bh(&tcp_md5sig_pool_lock); 2854 if (--tcp_md5sig_users == 0) { 2855 pool = tcp_md5sig_pool; 2856 tcp_md5sig_pool = NULL; 2857 } 2858 spin_unlock_bh(&tcp_md5sig_pool_lock); 2859 if (pool) 2860 __tcp_free_md5sig_pool(pool); 2861 } 2862 2863 EXPORT_SYMBOL(tcp_free_md5sig_pool); 2864 2865 static struct tcp_md5sig_pool * __percpu * 2866 __tcp_alloc_md5sig_pool(struct sock *sk) 2867 { 2868 int cpu; 2869 struct tcp_md5sig_pool * __percpu *pool; 2870 2871 pool = alloc_percpu(struct tcp_md5sig_pool *); 2872 if (!pool) 2873 return NULL; 2874 2875 for_each_possible_cpu(cpu) { 2876 struct tcp_md5sig_pool *p; 2877 struct crypto_hash *hash; 2878 2879 p = kzalloc(sizeof(*p), sk->sk_allocation); 2880 if (!p) 2881 goto out_free; 2882 *per_cpu_ptr(pool, cpu) = p; 2883 2884 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 2885 if (!hash || IS_ERR(hash)) 2886 goto out_free; 2887 2888 p->md5_desc.tfm = hash; 2889 } 2890 return pool; 2891 out_free: 2892 __tcp_free_md5sig_pool(pool); 2893 return NULL; 2894 } 2895 2896 struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *sk) 2897 { 2898 struct tcp_md5sig_pool * __percpu *pool; 2899 int alloc = 0; 2900 2901 retry: 2902 spin_lock_bh(&tcp_md5sig_pool_lock); 2903 pool = tcp_md5sig_pool; 2904 if (tcp_md5sig_users++ == 0) { 2905 alloc = 1; 2906 spin_unlock_bh(&tcp_md5sig_pool_lock); 2907 } else if (!pool) { 2908 tcp_md5sig_users--; 2909 spin_unlock_bh(&tcp_md5sig_pool_lock); 2910 cpu_relax(); 2911 goto retry; 2912 } else 2913 spin_unlock_bh(&tcp_md5sig_pool_lock); 2914 2915 if (alloc) { 2916 /* we cannot hold spinlock here because this may sleep. */ 2917 struct tcp_md5sig_pool * __percpu *p; 2918 2919 p = __tcp_alloc_md5sig_pool(sk); 2920 spin_lock_bh(&tcp_md5sig_pool_lock); 2921 if (!p) { 2922 tcp_md5sig_users--; 2923 spin_unlock_bh(&tcp_md5sig_pool_lock); 2924 return NULL; 2925 } 2926 pool = tcp_md5sig_pool; 2927 if (pool) { 2928 /* oops, it has already been assigned. */ 2929 spin_unlock_bh(&tcp_md5sig_pool_lock); 2930 __tcp_free_md5sig_pool(p); 2931 } else { 2932 tcp_md5sig_pool = pool = p; 2933 spin_unlock_bh(&tcp_md5sig_pool_lock); 2934 } 2935 } 2936 return pool; 2937 } 2938 2939 EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 2940 2941 2942 /** 2943 * tcp_get_md5sig_pool - get md5sig_pool for this user 2944 * 2945 * We use percpu structure, so if we succeed, we exit with preemption 2946 * and BH disabled, to make sure another thread or softirq handling 2947 * wont try to get same context. 2948 */ 2949 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) 2950 { 2951 struct tcp_md5sig_pool * __percpu *p; 2952 2953 local_bh_disable(); 2954 2955 spin_lock(&tcp_md5sig_pool_lock); 2956 p = tcp_md5sig_pool; 2957 if (p) 2958 tcp_md5sig_users++; 2959 spin_unlock(&tcp_md5sig_pool_lock); 2960 2961 if (p) 2962 return *per_cpu_ptr(p, smp_processor_id()); 2963 2964 local_bh_enable(); 2965 return NULL; 2966 } 2967 EXPORT_SYMBOL(tcp_get_md5sig_pool); 2968 2969 void tcp_put_md5sig_pool(void) 2970 { 2971 local_bh_enable(); 2972 tcp_free_md5sig_pool(); 2973 } 2974 EXPORT_SYMBOL(tcp_put_md5sig_pool); 2975 2976 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, 2977 struct tcphdr *th) 2978 { 2979 struct scatterlist sg; 2980 int err; 2981 2982 __sum16 old_checksum = th->check; 2983 th->check = 0; 2984 /* options aren't included in the hash */ 2985 sg_init_one(&sg, th, sizeof(struct tcphdr)); 2986 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr)); 2987 th->check = old_checksum; 2988 return err; 2989 } 2990 2991 EXPORT_SYMBOL(tcp_md5_hash_header); 2992 2993 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 2994 struct sk_buff *skb, unsigned header_len) 2995 { 2996 struct scatterlist sg; 2997 const struct tcphdr *tp = tcp_hdr(skb); 2998 struct hash_desc *desc = &hp->md5_desc; 2999 unsigned i; 3000 const unsigned head_data_len = skb_headlen(skb) > header_len ? 3001 skb_headlen(skb) - header_len : 0; 3002 const struct skb_shared_info *shi = skb_shinfo(skb); 3003 3004 sg_init_table(&sg, 1); 3005 3006 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 3007 if (crypto_hash_update(desc, &sg, head_data_len)) 3008 return 1; 3009 3010 for (i = 0; i < shi->nr_frags; ++i) { 3011 const struct skb_frag_struct *f = &shi->frags[i]; 3012 sg_set_page(&sg, f->page, f->size, f->page_offset); 3013 if (crypto_hash_update(desc, &sg, f->size)) 3014 return 1; 3015 } 3016 3017 return 0; 3018 } 3019 3020 EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3021 3022 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key) 3023 { 3024 struct scatterlist sg; 3025 3026 sg_init_one(&sg, key->key, key->keylen); 3027 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); 3028 } 3029 3030 EXPORT_SYMBOL(tcp_md5_hash_key); 3031 3032 #endif 3033 3034 /** 3035 * Each Responder maintains up to two secret values concurrently for 3036 * efficient secret rollover. Each secret value has 4 states: 3037 * 3038 * Generating. (tcp_secret_generating != tcp_secret_primary) 3039 * Generates new Responder-Cookies, but not yet used for primary 3040 * verification. This is a short-term state, typically lasting only 3041 * one round trip time (RTT). 3042 * 3043 * Primary. (tcp_secret_generating == tcp_secret_primary) 3044 * Used both for generation and primary verification. 3045 * 3046 * Retiring. (tcp_secret_retiring != tcp_secret_secondary) 3047 * Used for verification, until the first failure that can be 3048 * verified by the newer Generating secret. At that time, this 3049 * cookie's state is changed to Secondary, and the Generating 3050 * cookie's state is changed to Primary. This is a short-term state, 3051 * typically lasting only one round trip time (RTT). 3052 * 3053 * Secondary. (tcp_secret_retiring == tcp_secret_secondary) 3054 * Used for secondary verification, after primary verification 3055 * failures. This state lasts no more than twice the Maximum Segment 3056 * Lifetime (2MSL). Then, the secret is discarded. 3057 */ 3058 struct tcp_cookie_secret { 3059 /* The secret is divided into two parts. The digest part is the 3060 * equivalent of previously hashing a secret and saving the state, 3061 * and serves as an initialization vector (IV). The message part 3062 * serves as the trailing secret. 3063 */ 3064 u32 secrets[COOKIE_WORKSPACE_WORDS]; 3065 unsigned long expires; 3066 }; 3067 3068 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL) 3069 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2) 3070 #define TCP_SECRET_LIFE (HZ * 600) 3071 3072 static struct tcp_cookie_secret tcp_secret_one; 3073 static struct tcp_cookie_secret tcp_secret_two; 3074 3075 /* Essentially a circular list, without dynamic allocation. */ 3076 static struct tcp_cookie_secret *tcp_secret_generating; 3077 static struct tcp_cookie_secret *tcp_secret_primary; 3078 static struct tcp_cookie_secret *tcp_secret_retiring; 3079 static struct tcp_cookie_secret *tcp_secret_secondary; 3080 3081 static DEFINE_SPINLOCK(tcp_secret_locker); 3082 3083 /* Select a pseudo-random word in the cookie workspace. 3084 */ 3085 static inline u32 tcp_cookie_work(const u32 *ws, const int n) 3086 { 3087 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])]; 3088 } 3089 3090 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed. 3091 * Called in softirq context. 3092 * Returns: 0 for success. 3093 */ 3094 int tcp_cookie_generator(u32 *bakery) 3095 { 3096 unsigned long jiffy = jiffies; 3097 3098 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) { 3099 spin_lock_bh(&tcp_secret_locker); 3100 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) { 3101 /* refreshed by another */ 3102 memcpy(bakery, 3103 &tcp_secret_generating->secrets[0], 3104 COOKIE_WORKSPACE_WORDS); 3105 } else { 3106 /* still needs refreshing */ 3107 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS); 3108 3109 /* The first time, paranoia assumes that the 3110 * randomization function isn't as strong. But, 3111 * this secret initialization is delayed until 3112 * the last possible moment (packet arrival). 3113 * Although that time is observable, it is 3114 * unpredictably variable. Mash in the most 3115 * volatile clock bits available, and expire the 3116 * secret extra quickly. 3117 */ 3118 if (unlikely(tcp_secret_primary->expires == 3119 tcp_secret_secondary->expires)) { 3120 struct timespec tv; 3121 3122 getnstimeofday(&tv); 3123 bakery[COOKIE_DIGEST_WORDS+0] ^= 3124 (u32)tv.tv_nsec; 3125 3126 tcp_secret_secondary->expires = jiffy 3127 + TCP_SECRET_1MSL 3128 + (0x0f & tcp_cookie_work(bakery, 0)); 3129 } else { 3130 tcp_secret_secondary->expires = jiffy 3131 + TCP_SECRET_LIFE 3132 + (0xff & tcp_cookie_work(bakery, 1)); 3133 tcp_secret_primary->expires = jiffy 3134 + TCP_SECRET_2MSL 3135 + (0x1f & tcp_cookie_work(bakery, 2)); 3136 } 3137 memcpy(&tcp_secret_secondary->secrets[0], 3138 bakery, COOKIE_WORKSPACE_WORDS); 3139 3140 rcu_assign_pointer(tcp_secret_generating, 3141 tcp_secret_secondary); 3142 rcu_assign_pointer(tcp_secret_retiring, 3143 tcp_secret_primary); 3144 /* 3145 * Neither call_rcu() nor synchronize_rcu() needed. 3146 * Retiring data is not freed. It is replaced after 3147 * further (locked) pointer updates, and a quiet time 3148 * (minimum 1MSL, maximum LIFE - 2MSL). 3149 */ 3150 } 3151 spin_unlock_bh(&tcp_secret_locker); 3152 } else { 3153 rcu_read_lock_bh(); 3154 memcpy(bakery, 3155 &rcu_dereference(tcp_secret_generating)->secrets[0], 3156 COOKIE_WORKSPACE_WORDS); 3157 rcu_read_unlock_bh(); 3158 } 3159 return 0; 3160 } 3161 EXPORT_SYMBOL(tcp_cookie_generator); 3162 3163 void tcp_done(struct sock *sk) 3164 { 3165 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3166 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3167 3168 tcp_set_state(sk, TCP_CLOSE); 3169 tcp_clear_xmit_timers(sk); 3170 3171 sk->sk_shutdown = SHUTDOWN_MASK; 3172 3173 if (!sock_flag(sk, SOCK_DEAD)) 3174 sk->sk_state_change(sk); 3175 else 3176 inet_csk_destroy_sock(sk); 3177 } 3178 EXPORT_SYMBOL_GPL(tcp_done); 3179 3180 extern struct tcp_congestion_ops tcp_reno; 3181 3182 static __initdata unsigned long thash_entries; 3183 static int __init set_thash_entries(char *str) 3184 { 3185 if (!str) 3186 return 0; 3187 thash_entries = simple_strtoul(str, &str, 0); 3188 return 1; 3189 } 3190 __setup("thash_entries=", set_thash_entries); 3191 3192 void __init tcp_init(void) 3193 { 3194 struct sk_buff *skb = NULL; 3195 unsigned long nr_pages, limit; 3196 int order, i, max_share; 3197 unsigned long jiffy = jiffies; 3198 3199 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); 3200 3201 percpu_counter_init(&tcp_sockets_allocated, 0); 3202 percpu_counter_init(&tcp_orphan_count, 0); 3203 tcp_hashinfo.bind_bucket_cachep = 3204 kmem_cache_create("tcp_bind_bucket", 3205 sizeof(struct inet_bind_bucket), 0, 3206 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3207 3208 /* Size and allocate the main established and bind bucket 3209 * hash tables. 3210 * 3211 * The methodology is similar to that of the buffer cache. 3212 */ 3213 tcp_hashinfo.ehash = 3214 alloc_large_system_hash("TCP established", 3215 sizeof(struct inet_ehash_bucket), 3216 thash_entries, 3217 (totalram_pages >= 128 * 1024) ? 3218 13 : 15, 3219 0, 3220 NULL, 3221 &tcp_hashinfo.ehash_mask, 3222 thash_entries ? 0 : 512 * 1024); 3223 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) { 3224 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3225 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i); 3226 } 3227 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3228 panic("TCP: failed to alloc ehash_locks"); 3229 tcp_hashinfo.bhash = 3230 alloc_large_system_hash("TCP bind", 3231 sizeof(struct inet_bind_hashbucket), 3232 tcp_hashinfo.ehash_mask + 1, 3233 (totalram_pages >= 128 * 1024) ? 3234 13 : 15, 3235 0, 3236 &tcp_hashinfo.bhash_size, 3237 NULL, 3238 64 * 1024); 3239 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size; 3240 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3241 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3242 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3243 } 3244 3245 /* Try to be a bit smarter and adjust defaults depending 3246 * on available memory. 3247 */ 3248 for (order = 0; ((1 << order) << PAGE_SHIFT) < 3249 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket)); 3250 order++) 3251 ; 3252 if (order >= 4) { 3253 tcp_death_row.sysctl_max_tw_buckets = 180000; 3254 sysctl_tcp_max_orphans = 4096 << (order - 4); 3255 sysctl_max_syn_backlog = 1024; 3256 } else if (order < 3) { 3257 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order); 3258 sysctl_tcp_max_orphans >>= (3 - order); 3259 sysctl_max_syn_backlog = 128; 3260 } 3261 3262 /* Set the pressure threshold to be a fraction of global memory that 3263 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of 3264 * memory, with a floor of 128 pages. 3265 */ 3266 nr_pages = totalram_pages - totalhigh_pages; 3267 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); 3268 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); 3269 limit = max(limit, 128UL); 3270 sysctl_tcp_mem[0] = limit / 4 * 3; 3271 sysctl_tcp_mem[1] = limit; 3272 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; 3273 3274 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3275 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7); 3276 max_share = min(4UL*1024*1024, limit); 3277 3278 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3279 sysctl_tcp_wmem[1] = 16*1024; 3280 sysctl_tcp_wmem[2] = max(64*1024, max_share); 3281 3282 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3283 sysctl_tcp_rmem[1] = 87380; 3284 sysctl_tcp_rmem[2] = max(87380, max_share); 3285 3286 printk(KERN_INFO "TCP: Hash tables configured " 3287 "(established %u bind %u)\n", 3288 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3289 3290 tcp_register_congestion_control(&tcp_reno); 3291 3292 memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets)); 3293 memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets)); 3294 tcp_secret_one.expires = jiffy; /* past due */ 3295 tcp_secret_two.expires = jiffy; /* past due */ 3296 tcp_secret_generating = &tcp_secret_one; 3297 tcp_secret_primary = &tcp_secret_one; 3298 tcp_secret_retiring = &tcp_secret_two; 3299 tcp_secret_secondary = &tcp_secret_two; 3300 } 3301 3302 EXPORT_SYMBOL(tcp_close); 3303 EXPORT_SYMBOL(tcp_disconnect); 3304 EXPORT_SYMBOL(tcp_getsockopt); 3305 EXPORT_SYMBOL(tcp_ioctl); 3306 EXPORT_SYMBOL(tcp_poll); 3307 EXPORT_SYMBOL(tcp_read_sock); 3308 EXPORT_SYMBOL(tcp_recvmsg); 3309 EXPORT_SYMBOL(tcp_sendmsg); 3310 EXPORT_SYMBOL(tcp_splice_read); 3311 EXPORT_SYMBOL(tcp_sendpage); 3312 EXPORT_SYMBOL(tcp_setsockopt); 3313 EXPORT_SYMBOL(tcp_shutdown); 3314