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 * PF_INET protocol family socket handler. 7 * 8 * Version: $Id: af_inet.c,v 1.137 2002/02/01 22:01:03 davem Exp $ 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Florian La Roche, <flla@stud.uni-sb.de> 13 * Alan Cox, <A.Cox@swansea.ac.uk> 14 * 15 * Changes (see also sock.c) 16 * 17 * piggy, 18 * Karl Knutson : Socket protocol table 19 * A.N.Kuznetsov : Socket death error in accept(). 20 * John Richardson : Fix non blocking error in connect() 21 * so sockets that fail to connect 22 * don't return -EINPROGRESS. 23 * Alan Cox : Asynchronous I/O support 24 * Alan Cox : Keep correct socket pointer on sock 25 * structures 26 * when accept() ed 27 * Alan Cox : Semantics of SO_LINGER aren't state 28 * moved to close when you look carefully. 29 * With this fixed and the accept bug fixed 30 * some RPC stuff seems happier. 31 * Niibe Yutaka : 4.4BSD style write async I/O 32 * Alan Cox, 33 * Tony Gale : Fixed reuse semantics. 34 * Alan Cox : bind() shouldn't abort existing but dead 35 * sockets. Stops FTP netin:.. I hope. 36 * Alan Cox : bind() works correctly for RAW sockets. 37 * Note that FreeBSD at least was broken 38 * in this respect so be careful with 39 * compatibility tests... 40 * Alan Cox : routing cache support 41 * Alan Cox : memzero the socket structure for 42 * compactness. 43 * Matt Day : nonblock connect error handler 44 * Alan Cox : Allow large numbers of pending sockets 45 * (eg for big web sites), but only if 46 * specifically application requested. 47 * Alan Cox : New buffering throughout IP. Used 48 * dumbly. 49 * Alan Cox : New buffering now used smartly. 50 * Alan Cox : BSD rather than common sense 51 * interpretation of listen. 52 * Germano Caronni : Assorted small races. 53 * Alan Cox : sendmsg/recvmsg basic support. 54 * Alan Cox : Only sendmsg/recvmsg now supported. 55 * Alan Cox : Locked down bind (see security list). 56 * Alan Cox : Loosened bind a little. 57 * Mike McLagan : ADD/DEL DLCI Ioctls 58 * Willy Konynenberg : Transparent proxying support. 59 * David S. Miller : New socket lookup architecture. 60 * Some other random speedups. 61 * Cyrus Durgin : Cleaned up file for kmod hacks. 62 * Andi Kleen : Fix inet_stream_connect TCP race. 63 * 64 * This program is free software; you can redistribute it and/or 65 * modify it under the terms of the GNU General Public License 66 * as published by the Free Software Foundation; either version 67 * 2 of the License, or (at your option) any later version. 68 */ 69 70 #include <linux/err.h> 71 #include <linux/errno.h> 72 #include <linux/types.h> 73 #include <linux/socket.h> 74 #include <linux/in.h> 75 #include <linux/kernel.h> 76 #include <linux/module.h> 77 #include <linux/sched.h> 78 #include <linux/timer.h> 79 #include <linux/string.h> 80 #include <linux/sockios.h> 81 #include <linux/net.h> 82 #include <linux/capability.h> 83 #include <linux/fcntl.h> 84 #include <linux/mm.h> 85 #include <linux/interrupt.h> 86 #include <linux/stat.h> 87 #include <linux/init.h> 88 #include <linux/poll.h> 89 #include <linux/netfilter_ipv4.h> 90 91 #include <asm/uaccess.h> 92 #include <asm/system.h> 93 94 #include <linux/smp_lock.h> 95 #include <linux/inet.h> 96 #include <linux/igmp.h> 97 #include <linux/inetdevice.h> 98 #include <linux/netdevice.h> 99 #include <net/ip.h> 100 #include <net/protocol.h> 101 #include <net/arp.h> 102 #include <net/route.h> 103 #include <net/ip_fib.h> 104 #include <net/inet_connection_sock.h> 105 #include <net/tcp.h> 106 #include <net/udp.h> 107 #include <net/udplite.h> 108 #include <linux/skbuff.h> 109 #include <net/sock.h> 110 #include <net/raw.h> 111 #include <net/icmp.h> 112 #include <net/ipip.h> 113 #include <net/inet_common.h> 114 #include <net/xfrm.h> 115 #ifdef CONFIG_IP_MROUTE 116 #include <linux/mroute.h> 117 #endif 118 119 DEFINE_SNMP_STAT(struct linux_mib, net_statistics) __read_mostly; 120 121 extern void ip_mc_drop_socket(struct sock *sk); 122 123 /* The inetsw table contains everything that inet_create needs to 124 * build a new socket. 125 */ 126 static struct list_head inetsw[SOCK_MAX]; 127 static DEFINE_SPINLOCK(inetsw_lock); 128 129 /* New destruction routine */ 130 131 void inet_sock_destruct(struct sock *sk) 132 { 133 struct inet_sock *inet = inet_sk(sk); 134 135 __skb_queue_purge(&sk->sk_receive_queue); 136 __skb_queue_purge(&sk->sk_error_queue); 137 138 if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) { 139 printk("Attempt to release TCP socket in state %d %p\n", 140 sk->sk_state, sk); 141 return; 142 } 143 if (!sock_flag(sk, SOCK_DEAD)) { 144 printk("Attempt to release alive inet socket %p\n", sk); 145 return; 146 } 147 148 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); 149 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); 150 BUG_TRAP(!sk->sk_wmem_queued); 151 BUG_TRAP(!sk->sk_forward_alloc); 152 153 kfree(inet->opt); 154 dst_release(sk->sk_dst_cache); 155 sk_refcnt_debug_dec(sk); 156 } 157 158 /* 159 * The routines beyond this point handle the behaviour of an AF_INET 160 * socket object. Mostly it punts to the subprotocols of IP to do 161 * the work. 162 */ 163 164 /* 165 * Automatically bind an unbound socket. 166 */ 167 168 static int inet_autobind(struct sock *sk) 169 { 170 struct inet_sock *inet; 171 /* We may need to bind the socket. */ 172 lock_sock(sk); 173 inet = inet_sk(sk); 174 if (!inet->num) { 175 if (sk->sk_prot->get_port(sk, 0)) { 176 release_sock(sk); 177 return -EAGAIN; 178 } 179 inet->sport = htons(inet->num); 180 } 181 release_sock(sk); 182 return 0; 183 } 184 185 /* 186 * Move a socket into listening state. 187 */ 188 int inet_listen(struct socket *sock, int backlog) 189 { 190 struct sock *sk = sock->sk; 191 unsigned char old_state; 192 int err; 193 194 lock_sock(sk); 195 196 err = -EINVAL; 197 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM) 198 goto out; 199 200 old_state = sk->sk_state; 201 if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN))) 202 goto out; 203 204 /* Really, if the socket is already in listen state 205 * we can only allow the backlog to be adjusted. 206 */ 207 if (old_state != TCP_LISTEN) { 208 err = inet_csk_listen_start(sk, backlog); 209 if (err) 210 goto out; 211 } 212 sk->sk_max_ack_backlog = backlog; 213 err = 0; 214 215 out: 216 release_sock(sk); 217 return err; 218 } 219 220 /* 221 * Create an inet socket. 222 */ 223 224 static int inet_create(struct socket *sock, int protocol) 225 { 226 struct sock *sk; 227 struct list_head *p; 228 struct inet_protosw *answer; 229 struct inet_sock *inet; 230 struct proto *answer_prot; 231 unsigned char answer_flags; 232 char answer_no_check; 233 int try_loading_module = 0; 234 int err; 235 236 sock->state = SS_UNCONNECTED; 237 238 /* Look for the requested type/protocol pair. */ 239 answer = NULL; 240 lookup_protocol: 241 err = -ESOCKTNOSUPPORT; 242 rcu_read_lock(); 243 list_for_each_rcu(p, &inetsw[sock->type]) { 244 answer = list_entry(p, struct inet_protosw, list); 245 246 /* Check the non-wild match. */ 247 if (protocol == answer->protocol) { 248 if (protocol != IPPROTO_IP) 249 break; 250 } else { 251 /* Check for the two wild cases. */ 252 if (IPPROTO_IP == protocol) { 253 protocol = answer->protocol; 254 break; 255 } 256 if (IPPROTO_IP == answer->protocol) 257 break; 258 } 259 err = -EPROTONOSUPPORT; 260 answer = NULL; 261 } 262 263 if (unlikely(answer == NULL)) { 264 if (try_loading_module < 2) { 265 rcu_read_unlock(); 266 /* 267 * Be more specific, e.g. net-pf-2-proto-132-type-1 268 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM) 269 */ 270 if (++try_loading_module == 1) 271 request_module("net-pf-%d-proto-%d-type-%d", 272 PF_INET, protocol, sock->type); 273 /* 274 * Fall back to generic, e.g. net-pf-2-proto-132 275 * (net-pf-PF_INET-proto-IPPROTO_SCTP) 276 */ 277 else 278 request_module("net-pf-%d-proto-%d", 279 PF_INET, protocol); 280 goto lookup_protocol; 281 } else 282 goto out_rcu_unlock; 283 } 284 285 err = -EPERM; 286 if (answer->capability > 0 && !capable(answer->capability)) 287 goto out_rcu_unlock; 288 289 sock->ops = answer->ops; 290 answer_prot = answer->prot; 291 answer_no_check = answer->no_check; 292 answer_flags = answer->flags; 293 rcu_read_unlock(); 294 295 BUG_TRAP(answer_prot->slab != NULL); 296 297 err = -ENOBUFS; 298 sk = sk_alloc(PF_INET, GFP_KERNEL, answer_prot, 1); 299 if (sk == NULL) 300 goto out; 301 302 err = 0; 303 sk->sk_no_check = answer_no_check; 304 if (INET_PROTOSW_REUSE & answer_flags) 305 sk->sk_reuse = 1; 306 307 inet = inet_sk(sk); 308 inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0; 309 310 if (SOCK_RAW == sock->type) { 311 inet->num = protocol; 312 if (IPPROTO_RAW == protocol) 313 inet->hdrincl = 1; 314 } 315 316 if (ipv4_config.no_pmtu_disc) 317 inet->pmtudisc = IP_PMTUDISC_DONT; 318 else 319 inet->pmtudisc = IP_PMTUDISC_WANT; 320 321 inet->id = 0; 322 323 sock_init_data(sock, sk); 324 325 sk->sk_destruct = inet_sock_destruct; 326 sk->sk_family = PF_INET; 327 sk->sk_protocol = protocol; 328 sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv; 329 330 inet->uc_ttl = -1; 331 inet->mc_loop = 1; 332 inet->mc_ttl = 1; 333 inet->mc_index = 0; 334 inet->mc_list = NULL; 335 336 sk_refcnt_debug_inc(sk); 337 338 if (inet->num) { 339 /* It assumes that any protocol which allows 340 * the user to assign a number at socket 341 * creation time automatically 342 * shares. 343 */ 344 inet->sport = htons(inet->num); 345 /* Add to protocol hash chains. */ 346 sk->sk_prot->hash(sk); 347 } 348 349 if (sk->sk_prot->init) { 350 err = sk->sk_prot->init(sk); 351 if (err) 352 sk_common_release(sk); 353 } 354 out: 355 return err; 356 out_rcu_unlock: 357 rcu_read_unlock(); 358 goto out; 359 } 360 361 362 /* 363 * The peer socket should always be NULL (or else). When we call this 364 * function we are destroying the object and from then on nobody 365 * should refer to it. 366 */ 367 int inet_release(struct socket *sock) 368 { 369 struct sock *sk = sock->sk; 370 371 if (sk) { 372 long timeout; 373 374 /* Applications forget to leave groups before exiting */ 375 ip_mc_drop_socket(sk); 376 377 /* If linger is set, we don't return until the close 378 * is complete. Otherwise we return immediately. The 379 * actually closing is done the same either way. 380 * 381 * If the close is due to the process exiting, we never 382 * linger.. 383 */ 384 timeout = 0; 385 if (sock_flag(sk, SOCK_LINGER) && 386 !(current->flags & PF_EXITING)) 387 timeout = sk->sk_lingertime; 388 sock->sk = NULL; 389 sk->sk_prot->close(sk, timeout); 390 } 391 return 0; 392 } 393 394 /* It is off by default, see below. */ 395 int sysctl_ip_nonlocal_bind __read_mostly; 396 397 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 398 { 399 struct sockaddr_in *addr = (struct sockaddr_in *)uaddr; 400 struct sock *sk = sock->sk; 401 struct inet_sock *inet = inet_sk(sk); 402 unsigned short snum; 403 int chk_addr_ret; 404 int err; 405 406 /* If the socket has its own bind function then use it. (RAW) */ 407 if (sk->sk_prot->bind) { 408 err = sk->sk_prot->bind(sk, uaddr, addr_len); 409 goto out; 410 } 411 err = -EINVAL; 412 if (addr_len < sizeof(struct sockaddr_in)) 413 goto out; 414 415 chk_addr_ret = inet_addr_type(addr->sin_addr.s_addr); 416 417 /* Not specified by any standard per-se, however it breaks too 418 * many applications when removed. It is unfortunate since 419 * allowing applications to make a non-local bind solves 420 * several problems with systems using dynamic addressing. 421 * (ie. your servers still start up even if your ISDN link 422 * is temporarily down) 423 */ 424 err = -EADDRNOTAVAIL; 425 if (!sysctl_ip_nonlocal_bind && 426 !inet->freebind && 427 addr->sin_addr.s_addr != INADDR_ANY && 428 chk_addr_ret != RTN_LOCAL && 429 chk_addr_ret != RTN_MULTICAST && 430 chk_addr_ret != RTN_BROADCAST) 431 goto out; 432 433 snum = ntohs(addr->sin_port); 434 err = -EACCES; 435 if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE)) 436 goto out; 437 438 /* We keep a pair of addresses. rcv_saddr is the one 439 * used by hash lookups, and saddr is used for transmit. 440 * 441 * In the BSD API these are the same except where it 442 * would be illegal to use them (multicast/broadcast) in 443 * which case the sending device address is used. 444 */ 445 lock_sock(sk); 446 447 /* Check these errors (active socket, double bind). */ 448 err = -EINVAL; 449 if (sk->sk_state != TCP_CLOSE || inet->num) 450 goto out_release_sock; 451 452 inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr; 453 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) 454 inet->saddr = 0; /* Use device */ 455 456 /* Make sure we are allowed to bind here. */ 457 if (sk->sk_prot->get_port(sk, snum)) { 458 inet->saddr = inet->rcv_saddr = 0; 459 err = -EADDRINUSE; 460 goto out_release_sock; 461 } 462 463 if (inet->rcv_saddr) 464 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 465 if (snum) 466 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 467 inet->sport = htons(inet->num); 468 inet->daddr = 0; 469 inet->dport = 0; 470 sk_dst_reset(sk); 471 err = 0; 472 out_release_sock: 473 release_sock(sk); 474 out: 475 return err; 476 } 477 478 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr, 479 int addr_len, int flags) 480 { 481 struct sock *sk = sock->sk; 482 483 if (uaddr->sa_family == AF_UNSPEC) 484 return sk->sk_prot->disconnect(sk, flags); 485 486 if (!inet_sk(sk)->num && inet_autobind(sk)) 487 return -EAGAIN; 488 return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len); 489 } 490 491 static long inet_wait_for_connect(struct sock *sk, long timeo) 492 { 493 DEFINE_WAIT(wait); 494 495 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 496 497 /* Basic assumption: if someone sets sk->sk_err, he _must_ 498 * change state of the socket from TCP_SYN_*. 499 * Connect() does not allow to get error notifications 500 * without closing the socket. 501 */ 502 while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { 503 release_sock(sk); 504 timeo = schedule_timeout(timeo); 505 lock_sock(sk); 506 if (signal_pending(current) || !timeo) 507 break; 508 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 509 } 510 finish_wait(sk->sk_sleep, &wait); 511 return timeo; 512 } 513 514 /* 515 * Connect to a remote host. There is regrettably still a little 516 * TCP 'magic' in here. 517 */ 518 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, 519 int addr_len, int flags) 520 { 521 struct sock *sk = sock->sk; 522 int err; 523 long timeo; 524 525 lock_sock(sk); 526 527 if (uaddr->sa_family == AF_UNSPEC) { 528 err = sk->sk_prot->disconnect(sk, flags); 529 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; 530 goto out; 531 } 532 533 switch (sock->state) { 534 default: 535 err = -EINVAL; 536 goto out; 537 case SS_CONNECTED: 538 err = -EISCONN; 539 goto out; 540 case SS_CONNECTING: 541 err = -EALREADY; 542 /* Fall out of switch with err, set for this state */ 543 break; 544 case SS_UNCONNECTED: 545 err = -EISCONN; 546 if (sk->sk_state != TCP_CLOSE) 547 goto out; 548 549 err = sk->sk_prot->connect(sk, uaddr, addr_len); 550 if (err < 0) 551 goto out; 552 553 sock->state = SS_CONNECTING; 554 555 /* Just entered SS_CONNECTING state; the only 556 * difference is that return value in non-blocking 557 * case is EINPROGRESS, rather than EALREADY. 558 */ 559 err = -EINPROGRESS; 560 break; 561 } 562 563 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 564 565 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { 566 /* Error code is set above */ 567 if (!timeo || !inet_wait_for_connect(sk, timeo)) 568 goto out; 569 570 err = sock_intr_errno(timeo); 571 if (signal_pending(current)) 572 goto out; 573 } 574 575 /* Connection was closed by RST, timeout, ICMP error 576 * or another process disconnected us. 577 */ 578 if (sk->sk_state == TCP_CLOSE) 579 goto sock_error; 580 581 /* sk->sk_err may be not zero now, if RECVERR was ordered by user 582 * and error was received after socket entered established state. 583 * Hence, it is handled normally after connect() return successfully. 584 */ 585 586 sock->state = SS_CONNECTED; 587 err = 0; 588 out: 589 release_sock(sk); 590 return err; 591 592 sock_error: 593 err = sock_error(sk) ? : -ECONNABORTED; 594 sock->state = SS_UNCONNECTED; 595 if (sk->sk_prot->disconnect(sk, flags)) 596 sock->state = SS_DISCONNECTING; 597 goto out; 598 } 599 600 /* 601 * Accept a pending connection. The TCP layer now gives BSD semantics. 602 */ 603 604 int inet_accept(struct socket *sock, struct socket *newsock, int flags) 605 { 606 struct sock *sk1 = sock->sk; 607 int err = -EINVAL; 608 struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err); 609 610 if (!sk2) 611 goto do_err; 612 613 lock_sock(sk2); 614 615 BUG_TRAP((1 << sk2->sk_state) & 616 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)); 617 618 sock_graft(sk2, newsock); 619 620 newsock->state = SS_CONNECTED; 621 err = 0; 622 release_sock(sk2); 623 do_err: 624 return err; 625 } 626 627 628 /* 629 * This does both peername and sockname. 630 */ 631 int inet_getname(struct socket *sock, struct sockaddr *uaddr, 632 int *uaddr_len, int peer) 633 { 634 struct sock *sk = sock->sk; 635 struct inet_sock *inet = inet_sk(sk); 636 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; 637 638 sin->sin_family = AF_INET; 639 if (peer) { 640 if (!inet->dport || 641 (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) && 642 peer == 1)) 643 return -ENOTCONN; 644 sin->sin_port = inet->dport; 645 sin->sin_addr.s_addr = inet->daddr; 646 } else { 647 __be32 addr = inet->rcv_saddr; 648 if (!addr) 649 addr = inet->saddr; 650 sin->sin_port = inet->sport; 651 sin->sin_addr.s_addr = addr; 652 } 653 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 654 *uaddr_len = sizeof(*sin); 655 return 0; 656 } 657 658 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, 659 size_t size) 660 { 661 struct sock *sk = sock->sk; 662 663 /* We may need to bind the socket. */ 664 if (!inet_sk(sk)->num && inet_autobind(sk)) 665 return -EAGAIN; 666 667 return sk->sk_prot->sendmsg(iocb, sk, msg, size); 668 } 669 670 671 static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags) 672 { 673 struct sock *sk = sock->sk; 674 675 /* We may need to bind the socket. */ 676 if (!inet_sk(sk)->num && inet_autobind(sk)) 677 return -EAGAIN; 678 679 if (sk->sk_prot->sendpage) 680 return sk->sk_prot->sendpage(sk, page, offset, size, flags); 681 return sock_no_sendpage(sock, page, offset, size, flags); 682 } 683 684 685 int inet_shutdown(struct socket *sock, int how) 686 { 687 struct sock *sk = sock->sk; 688 int err = 0; 689 690 /* This should really check to make sure 691 * the socket is a TCP socket. (WHY AC...) 692 */ 693 how++; /* maps 0->1 has the advantage of making bit 1 rcvs and 694 1->2 bit 2 snds. 695 2->3 */ 696 if ((how & ~SHUTDOWN_MASK) || !how) /* MAXINT->0 */ 697 return -EINVAL; 698 699 lock_sock(sk); 700 if (sock->state == SS_CONNECTING) { 701 if ((1 << sk->sk_state) & 702 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)) 703 sock->state = SS_DISCONNECTING; 704 else 705 sock->state = SS_CONNECTED; 706 } 707 708 switch (sk->sk_state) { 709 case TCP_CLOSE: 710 err = -ENOTCONN; 711 /* Hack to wake up other listeners, who can poll for 712 POLLHUP, even on eg. unconnected UDP sockets -- RR */ 713 default: 714 sk->sk_shutdown |= how; 715 if (sk->sk_prot->shutdown) 716 sk->sk_prot->shutdown(sk, how); 717 break; 718 719 /* Remaining two branches are temporary solution for missing 720 * close() in multithreaded environment. It is _not_ a good idea, 721 * but we have no choice until close() is repaired at VFS level. 722 */ 723 case TCP_LISTEN: 724 if (!(how & RCV_SHUTDOWN)) 725 break; 726 /* Fall through */ 727 case TCP_SYN_SENT: 728 err = sk->sk_prot->disconnect(sk, O_NONBLOCK); 729 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; 730 break; 731 } 732 733 /* Wake up anyone sleeping in poll. */ 734 sk->sk_state_change(sk); 735 release_sock(sk); 736 return err; 737 } 738 739 /* 740 * ioctl() calls you can issue on an INET socket. Most of these are 741 * device configuration and stuff and very rarely used. Some ioctls 742 * pass on to the socket itself. 743 * 744 * NOTE: I like the idea of a module for the config stuff. ie ifconfig 745 * loads the devconfigure module does its configuring and unloads it. 746 * There's a good 20K of config code hanging around the kernel. 747 */ 748 749 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 750 { 751 struct sock *sk = sock->sk; 752 int err = 0; 753 754 switch (cmd) { 755 case SIOCGSTAMP: 756 err = sock_get_timestamp(sk, (struct timeval __user *)arg); 757 break; 758 case SIOCADDRT: 759 case SIOCDELRT: 760 case SIOCRTMSG: 761 err = ip_rt_ioctl(cmd, (void __user *)arg); 762 break; 763 case SIOCDARP: 764 case SIOCGARP: 765 case SIOCSARP: 766 err = arp_ioctl(cmd, (void __user *)arg); 767 break; 768 case SIOCGIFADDR: 769 case SIOCSIFADDR: 770 case SIOCGIFBRDADDR: 771 case SIOCSIFBRDADDR: 772 case SIOCGIFNETMASK: 773 case SIOCSIFNETMASK: 774 case SIOCGIFDSTADDR: 775 case SIOCSIFDSTADDR: 776 case SIOCSIFPFLAGS: 777 case SIOCGIFPFLAGS: 778 case SIOCSIFFLAGS: 779 err = devinet_ioctl(cmd, (void __user *)arg); 780 break; 781 default: 782 if (sk->sk_prot->ioctl) 783 err = sk->sk_prot->ioctl(sk, cmd, arg); 784 else 785 err = -ENOIOCTLCMD; 786 break; 787 } 788 return err; 789 } 790 791 const struct proto_ops inet_stream_ops = { 792 .family = PF_INET, 793 .owner = THIS_MODULE, 794 .release = inet_release, 795 .bind = inet_bind, 796 .connect = inet_stream_connect, 797 .socketpair = sock_no_socketpair, 798 .accept = inet_accept, 799 .getname = inet_getname, 800 .poll = tcp_poll, 801 .ioctl = inet_ioctl, 802 .listen = inet_listen, 803 .shutdown = inet_shutdown, 804 .setsockopt = sock_common_setsockopt, 805 .getsockopt = sock_common_getsockopt, 806 .sendmsg = inet_sendmsg, 807 .recvmsg = sock_common_recvmsg, 808 .mmap = sock_no_mmap, 809 .sendpage = tcp_sendpage, 810 #ifdef CONFIG_COMPAT 811 .compat_setsockopt = compat_sock_common_setsockopt, 812 .compat_getsockopt = compat_sock_common_getsockopt, 813 #endif 814 }; 815 816 const struct proto_ops inet_dgram_ops = { 817 .family = PF_INET, 818 .owner = THIS_MODULE, 819 .release = inet_release, 820 .bind = inet_bind, 821 .connect = inet_dgram_connect, 822 .socketpair = sock_no_socketpair, 823 .accept = sock_no_accept, 824 .getname = inet_getname, 825 .poll = udp_poll, 826 .ioctl = inet_ioctl, 827 .listen = sock_no_listen, 828 .shutdown = inet_shutdown, 829 .setsockopt = sock_common_setsockopt, 830 .getsockopt = sock_common_getsockopt, 831 .sendmsg = inet_sendmsg, 832 .recvmsg = sock_common_recvmsg, 833 .mmap = sock_no_mmap, 834 .sendpage = inet_sendpage, 835 #ifdef CONFIG_COMPAT 836 .compat_setsockopt = compat_sock_common_setsockopt, 837 .compat_getsockopt = compat_sock_common_getsockopt, 838 #endif 839 }; 840 841 /* 842 * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without 843 * udp_poll 844 */ 845 static const struct proto_ops inet_sockraw_ops = { 846 .family = PF_INET, 847 .owner = THIS_MODULE, 848 .release = inet_release, 849 .bind = inet_bind, 850 .connect = inet_dgram_connect, 851 .socketpair = sock_no_socketpair, 852 .accept = sock_no_accept, 853 .getname = inet_getname, 854 .poll = datagram_poll, 855 .ioctl = inet_ioctl, 856 .listen = sock_no_listen, 857 .shutdown = inet_shutdown, 858 .setsockopt = sock_common_setsockopt, 859 .getsockopt = sock_common_getsockopt, 860 .sendmsg = inet_sendmsg, 861 .recvmsg = sock_common_recvmsg, 862 .mmap = sock_no_mmap, 863 .sendpage = inet_sendpage, 864 #ifdef CONFIG_COMPAT 865 .compat_setsockopt = compat_sock_common_setsockopt, 866 .compat_getsockopt = compat_sock_common_getsockopt, 867 #endif 868 }; 869 870 static struct net_proto_family inet_family_ops = { 871 .family = PF_INET, 872 .create = inet_create, 873 .owner = THIS_MODULE, 874 }; 875 876 /* Upon startup we insert all the elements in inetsw_array[] into 877 * the linked list inetsw. 878 */ 879 static struct inet_protosw inetsw_array[] = 880 { 881 { 882 .type = SOCK_STREAM, 883 .protocol = IPPROTO_TCP, 884 .prot = &tcp_prot, 885 .ops = &inet_stream_ops, 886 .capability = -1, 887 .no_check = 0, 888 .flags = INET_PROTOSW_PERMANENT | 889 INET_PROTOSW_ICSK, 890 }, 891 892 { 893 .type = SOCK_DGRAM, 894 .protocol = IPPROTO_UDP, 895 .prot = &udp_prot, 896 .ops = &inet_dgram_ops, 897 .capability = -1, 898 .no_check = UDP_CSUM_DEFAULT, 899 .flags = INET_PROTOSW_PERMANENT, 900 }, 901 902 903 { 904 .type = SOCK_RAW, 905 .protocol = IPPROTO_IP, /* wild card */ 906 .prot = &raw_prot, 907 .ops = &inet_sockraw_ops, 908 .capability = CAP_NET_RAW, 909 .no_check = UDP_CSUM_DEFAULT, 910 .flags = INET_PROTOSW_REUSE, 911 } 912 }; 913 914 #define INETSW_ARRAY_LEN (sizeof(inetsw_array) / sizeof(struct inet_protosw)) 915 916 void inet_register_protosw(struct inet_protosw *p) 917 { 918 struct list_head *lh; 919 struct inet_protosw *answer; 920 int protocol = p->protocol; 921 struct list_head *last_perm; 922 923 spin_lock_bh(&inetsw_lock); 924 925 if (p->type >= SOCK_MAX) 926 goto out_illegal; 927 928 /* If we are trying to override a permanent protocol, bail. */ 929 answer = NULL; 930 last_perm = &inetsw[p->type]; 931 list_for_each(lh, &inetsw[p->type]) { 932 answer = list_entry(lh, struct inet_protosw, list); 933 934 /* Check only the non-wild match. */ 935 if (INET_PROTOSW_PERMANENT & answer->flags) { 936 if (protocol == answer->protocol) 937 break; 938 last_perm = lh; 939 } 940 941 answer = NULL; 942 } 943 if (answer) 944 goto out_permanent; 945 946 /* Add the new entry after the last permanent entry if any, so that 947 * the new entry does not override a permanent entry when matched with 948 * a wild-card protocol. But it is allowed to override any existing 949 * non-permanent entry. This means that when we remove this entry, the 950 * system automatically returns to the old behavior. 951 */ 952 list_add_rcu(&p->list, last_perm); 953 out: 954 spin_unlock_bh(&inetsw_lock); 955 956 synchronize_net(); 957 958 return; 959 960 out_permanent: 961 printk(KERN_ERR "Attempt to override permanent protocol %d.\n", 962 protocol); 963 goto out; 964 965 out_illegal: 966 printk(KERN_ERR 967 "Ignoring attempt to register invalid socket type %d.\n", 968 p->type); 969 goto out; 970 } 971 972 void inet_unregister_protosw(struct inet_protosw *p) 973 { 974 if (INET_PROTOSW_PERMANENT & p->flags) { 975 printk(KERN_ERR 976 "Attempt to unregister permanent protocol %d.\n", 977 p->protocol); 978 } else { 979 spin_lock_bh(&inetsw_lock); 980 list_del_rcu(&p->list); 981 spin_unlock_bh(&inetsw_lock); 982 983 synchronize_net(); 984 } 985 } 986 987 /* 988 * Shall we try to damage output packets if routing dev changes? 989 */ 990 991 int sysctl_ip_dynaddr __read_mostly; 992 993 static int inet_sk_reselect_saddr(struct sock *sk) 994 { 995 struct inet_sock *inet = inet_sk(sk); 996 int err; 997 struct rtable *rt; 998 __be32 old_saddr = inet->saddr; 999 __be32 new_saddr; 1000 __be32 daddr = inet->daddr; 1001 1002 if (inet->opt && inet->opt->srr) 1003 daddr = inet->opt->faddr; 1004 1005 /* Query new route. */ 1006 err = ip_route_connect(&rt, daddr, 0, 1007 RT_CONN_FLAGS(sk), 1008 sk->sk_bound_dev_if, 1009 sk->sk_protocol, 1010 inet->sport, inet->dport, sk, 0); 1011 if (err) 1012 return err; 1013 1014 sk_setup_caps(sk, &rt->u.dst); 1015 1016 new_saddr = rt->rt_src; 1017 1018 if (new_saddr == old_saddr) 1019 return 0; 1020 1021 if (sysctl_ip_dynaddr > 1) { 1022 printk(KERN_INFO "%s(): shifting inet->" 1023 "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n", 1024 __FUNCTION__, 1025 NIPQUAD(old_saddr), 1026 NIPQUAD(new_saddr)); 1027 } 1028 1029 inet->saddr = inet->rcv_saddr = new_saddr; 1030 1031 /* 1032 * XXX The only one ugly spot where we need to 1033 * XXX really change the sockets identity after 1034 * XXX it has entered the hashes. -DaveM 1035 * 1036 * Besides that, it does not check for connection 1037 * uniqueness. Wait for troubles. 1038 */ 1039 __sk_prot_rehash(sk); 1040 return 0; 1041 } 1042 1043 int inet_sk_rebuild_header(struct sock *sk) 1044 { 1045 struct inet_sock *inet = inet_sk(sk); 1046 struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0); 1047 __be32 daddr; 1048 int err; 1049 1050 /* Route is OK, nothing to do. */ 1051 if (rt) 1052 return 0; 1053 1054 /* Reroute. */ 1055 daddr = inet->daddr; 1056 if (inet->opt && inet->opt->srr) 1057 daddr = inet->opt->faddr; 1058 { 1059 struct flowi fl = { 1060 .oif = sk->sk_bound_dev_if, 1061 .nl_u = { 1062 .ip4_u = { 1063 .daddr = daddr, 1064 .saddr = inet->saddr, 1065 .tos = RT_CONN_FLAGS(sk), 1066 }, 1067 }, 1068 .proto = sk->sk_protocol, 1069 .uli_u = { 1070 .ports = { 1071 .sport = inet->sport, 1072 .dport = inet->dport, 1073 }, 1074 }, 1075 }; 1076 1077 security_sk_classify_flow(sk, &fl); 1078 err = ip_route_output_flow(&rt, &fl, sk, 0); 1079 } 1080 if (!err) 1081 sk_setup_caps(sk, &rt->u.dst); 1082 else { 1083 /* Routing failed... */ 1084 sk->sk_route_caps = 0; 1085 /* 1086 * Other protocols have to map its equivalent state to TCP_SYN_SENT. 1087 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme 1088 */ 1089 if (!sysctl_ip_dynaddr || 1090 sk->sk_state != TCP_SYN_SENT || 1091 (sk->sk_userlocks & SOCK_BINDADDR_LOCK) || 1092 (err = inet_sk_reselect_saddr(sk)) != 0) 1093 sk->sk_err_soft = -err; 1094 } 1095 1096 return err; 1097 } 1098 1099 EXPORT_SYMBOL(inet_sk_rebuild_header); 1100 1101 static int inet_gso_send_check(struct sk_buff *skb) 1102 { 1103 struct iphdr *iph; 1104 struct net_protocol *ops; 1105 int proto; 1106 int ihl; 1107 int err = -EINVAL; 1108 1109 if (unlikely(!pskb_may_pull(skb, sizeof(*iph)))) 1110 goto out; 1111 1112 iph = skb->nh.iph; 1113 ihl = iph->ihl * 4; 1114 if (ihl < sizeof(*iph)) 1115 goto out; 1116 1117 if (unlikely(!pskb_may_pull(skb, ihl))) 1118 goto out; 1119 1120 skb->h.raw = __skb_pull(skb, ihl); 1121 iph = skb->nh.iph; 1122 proto = iph->protocol & (MAX_INET_PROTOS - 1); 1123 err = -EPROTONOSUPPORT; 1124 1125 rcu_read_lock(); 1126 ops = rcu_dereference(inet_protos[proto]); 1127 if (likely(ops && ops->gso_send_check)) 1128 err = ops->gso_send_check(skb); 1129 rcu_read_unlock(); 1130 1131 out: 1132 return err; 1133 } 1134 1135 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features) 1136 { 1137 struct sk_buff *segs = ERR_PTR(-EINVAL); 1138 struct iphdr *iph; 1139 struct net_protocol *ops; 1140 int proto; 1141 int ihl; 1142 int id; 1143 1144 if (unlikely(skb_shinfo(skb)->gso_type & 1145 ~(SKB_GSO_TCPV4 | 1146 SKB_GSO_UDP | 1147 SKB_GSO_DODGY | 1148 SKB_GSO_TCP_ECN | 1149 0))) 1150 goto out; 1151 1152 if (unlikely(!pskb_may_pull(skb, sizeof(*iph)))) 1153 goto out; 1154 1155 iph = skb->nh.iph; 1156 ihl = iph->ihl * 4; 1157 if (ihl < sizeof(*iph)) 1158 goto out; 1159 1160 if (unlikely(!pskb_may_pull(skb, ihl))) 1161 goto out; 1162 1163 skb->h.raw = __skb_pull(skb, ihl); 1164 iph = skb->nh.iph; 1165 id = ntohs(iph->id); 1166 proto = iph->protocol & (MAX_INET_PROTOS - 1); 1167 segs = ERR_PTR(-EPROTONOSUPPORT); 1168 1169 rcu_read_lock(); 1170 ops = rcu_dereference(inet_protos[proto]); 1171 if (likely(ops && ops->gso_segment)) 1172 segs = ops->gso_segment(skb, features); 1173 rcu_read_unlock(); 1174 1175 if (!segs || unlikely(IS_ERR(segs))) 1176 goto out; 1177 1178 skb = segs; 1179 do { 1180 iph = skb->nh.iph; 1181 iph->id = htons(id++); 1182 iph->tot_len = htons(skb->len - skb->mac_len); 1183 iph->check = 0; 1184 iph->check = ip_fast_csum(skb->nh.raw, iph->ihl); 1185 } while ((skb = skb->next)); 1186 1187 out: 1188 return segs; 1189 } 1190 1191 #ifdef CONFIG_IP_MULTICAST 1192 static struct net_protocol igmp_protocol = { 1193 .handler = igmp_rcv, 1194 }; 1195 #endif 1196 1197 static struct net_protocol tcp_protocol = { 1198 .handler = tcp_v4_rcv, 1199 .err_handler = tcp_v4_err, 1200 .gso_send_check = tcp_v4_gso_send_check, 1201 .gso_segment = tcp_tso_segment, 1202 .no_policy = 1, 1203 }; 1204 1205 static struct net_protocol udp_protocol = { 1206 .handler = udp_rcv, 1207 .err_handler = udp_err, 1208 .no_policy = 1, 1209 }; 1210 1211 static struct net_protocol icmp_protocol = { 1212 .handler = icmp_rcv, 1213 }; 1214 1215 static int __init init_ipv4_mibs(void) 1216 { 1217 net_statistics[0] = alloc_percpu(struct linux_mib); 1218 net_statistics[1] = alloc_percpu(struct linux_mib); 1219 ip_statistics[0] = alloc_percpu(struct ipstats_mib); 1220 ip_statistics[1] = alloc_percpu(struct ipstats_mib); 1221 icmp_statistics[0] = alloc_percpu(struct icmp_mib); 1222 icmp_statistics[1] = alloc_percpu(struct icmp_mib); 1223 tcp_statistics[0] = alloc_percpu(struct tcp_mib); 1224 tcp_statistics[1] = alloc_percpu(struct tcp_mib); 1225 udp_statistics[0] = alloc_percpu(struct udp_mib); 1226 udp_statistics[1] = alloc_percpu(struct udp_mib); 1227 udplite_statistics[0] = alloc_percpu(struct udp_mib); 1228 udplite_statistics[1] = alloc_percpu(struct udp_mib); 1229 if (! 1230 (net_statistics[0] && net_statistics[1] && ip_statistics[0] 1231 && ip_statistics[1] && tcp_statistics[0] && tcp_statistics[1] 1232 && udp_statistics[0] && udp_statistics[1] 1233 && udplite_statistics[0] && udplite_statistics[1] ) ) 1234 return -ENOMEM; 1235 1236 (void) tcp_mib_init(); 1237 1238 return 0; 1239 } 1240 1241 static int ipv4_proc_init(void); 1242 1243 /* 1244 * IP protocol layer initialiser 1245 */ 1246 1247 static struct packet_type ip_packet_type = { 1248 .type = __constant_htons(ETH_P_IP), 1249 .func = ip_rcv, 1250 .gso_send_check = inet_gso_send_check, 1251 .gso_segment = inet_gso_segment, 1252 }; 1253 1254 static int __init inet_init(void) 1255 { 1256 struct sk_buff *dummy_skb; 1257 struct inet_protosw *q; 1258 struct list_head *r; 1259 int rc = -EINVAL; 1260 1261 BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb)); 1262 1263 rc = proto_register(&tcp_prot, 1); 1264 if (rc) 1265 goto out; 1266 1267 rc = proto_register(&udp_prot, 1); 1268 if (rc) 1269 goto out_unregister_tcp_proto; 1270 1271 rc = proto_register(&raw_prot, 1); 1272 if (rc) 1273 goto out_unregister_udp_proto; 1274 1275 /* 1276 * Tell SOCKET that we are alive... 1277 */ 1278 1279 (void)sock_register(&inet_family_ops); 1280 1281 /* 1282 * Add all the base protocols. 1283 */ 1284 1285 if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0) 1286 printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n"); 1287 if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0) 1288 printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n"); 1289 if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0) 1290 printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n"); 1291 #ifdef CONFIG_IP_MULTICAST 1292 if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0) 1293 printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n"); 1294 #endif 1295 1296 /* Register the socket-side information for inet_create. */ 1297 for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r) 1298 INIT_LIST_HEAD(r); 1299 1300 for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q) 1301 inet_register_protosw(q); 1302 1303 /* 1304 * Set the ARP module up 1305 */ 1306 1307 arp_init(); 1308 1309 /* 1310 * Set the IP module up 1311 */ 1312 1313 ip_init(); 1314 1315 tcp_v4_init(&inet_family_ops); 1316 1317 /* Setup TCP slab cache for open requests. */ 1318 tcp_init(); 1319 1320 /* Add UDP-Lite (RFC 3828) */ 1321 udplite4_register(); 1322 1323 /* 1324 * Set the ICMP layer up 1325 */ 1326 1327 icmp_init(&inet_family_ops); 1328 1329 /* 1330 * Initialise the multicast router 1331 */ 1332 #if defined(CONFIG_IP_MROUTE) 1333 ip_mr_init(); 1334 #endif 1335 /* 1336 * Initialise per-cpu ipv4 mibs 1337 */ 1338 1339 if(init_ipv4_mibs()) 1340 printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n"); ; 1341 1342 ipv4_proc_init(); 1343 1344 ipfrag_init(); 1345 1346 dev_add_pack(&ip_packet_type); 1347 1348 rc = 0; 1349 out: 1350 return rc; 1351 out_unregister_udp_proto: 1352 proto_unregister(&udp_prot); 1353 out_unregister_tcp_proto: 1354 proto_unregister(&tcp_prot); 1355 goto out; 1356 } 1357 1358 fs_initcall(inet_init); 1359 1360 /* ------------------------------------------------------------------------ */ 1361 1362 #ifdef CONFIG_PROC_FS 1363 static int __init ipv4_proc_init(void) 1364 { 1365 int rc = 0; 1366 1367 if (raw_proc_init()) 1368 goto out_raw; 1369 if (tcp4_proc_init()) 1370 goto out_tcp; 1371 if (udp4_proc_init()) 1372 goto out_udp; 1373 if (fib_proc_init()) 1374 goto out_fib; 1375 if (ip_misc_proc_init()) 1376 goto out_misc; 1377 out: 1378 return rc; 1379 out_misc: 1380 fib_proc_exit(); 1381 out_fib: 1382 udp4_proc_exit(); 1383 out_udp: 1384 tcp4_proc_exit(); 1385 out_tcp: 1386 raw_proc_exit(); 1387 out_raw: 1388 rc = -ENOMEM; 1389 goto out; 1390 } 1391 1392 #else /* CONFIG_PROC_FS */ 1393 static int __init ipv4_proc_init(void) 1394 { 1395 return 0; 1396 } 1397 #endif /* CONFIG_PROC_FS */ 1398 1399 MODULE_ALIAS_NETPROTO(PF_INET); 1400 1401 EXPORT_SYMBOL(inet_accept); 1402 EXPORT_SYMBOL(inet_bind); 1403 EXPORT_SYMBOL(inet_dgram_connect); 1404 EXPORT_SYMBOL(inet_dgram_ops); 1405 EXPORT_SYMBOL(inet_getname); 1406 EXPORT_SYMBOL(inet_ioctl); 1407 EXPORT_SYMBOL(inet_listen); 1408 EXPORT_SYMBOL(inet_register_protosw); 1409 EXPORT_SYMBOL(inet_release); 1410 EXPORT_SYMBOL(inet_sendmsg); 1411 EXPORT_SYMBOL(inet_shutdown); 1412 EXPORT_SYMBOL(inet_sock_destruct); 1413 EXPORT_SYMBOL(inet_stream_connect); 1414 EXPORT_SYMBOL(inet_stream_ops); 1415 EXPORT_SYMBOL(inet_unregister_protosw); 1416 EXPORT_SYMBOL(net_statistics); 1417 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind); 1418