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