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/config.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/fcntl.h> 83 #include <linux/mm.h> 84 #include <linux/interrupt.h> 85 #include <linux/stat.h> 86 #include <linux/init.h> 87 #include <linux/poll.h> 88 #include <linux/netfilter_ipv4.h> 89 90 #include <asm/uaccess.h> 91 #include <asm/system.h> 92 93 #include <linux/smp_lock.h> 94 #include <linux/inet.h> 95 #include <linux/igmp.h> 96 #include <linux/inetdevice.h> 97 #include <linux/netdevice.h> 98 #include <net/ip.h> 99 #include <net/protocol.h> 100 #include <net/arp.h> 101 #include <net/route.h> 102 #include <net/ip_fib.h> 103 #include <net/inet_connection_sock.h> 104 #include <net/tcp.h> 105 #include <net/udp.h> 106 #include <linux/skbuff.h> 107 #include <net/sock.h> 108 #include <net/raw.h> 109 #include <net/icmp.h> 110 #include <net/ipip.h> 111 #include <net/inet_common.h> 112 #include <net/xfrm.h> 113 #ifdef CONFIG_IP_MROUTE 114 #include <linux/mroute.h> 115 #endif 116 117 DEFINE_SNMP_STAT(struct linux_mib, net_statistics) __read_mostly; 118 119 extern void ip_mc_drop_socket(struct sock *sk); 120 121 /* The inetsw table contains everything that inet_create needs to 122 * build a new socket. 123 */ 124 static struct list_head inetsw[SOCK_MAX]; 125 static DEFINE_SPINLOCK(inetsw_lock); 126 127 /* New destruction routine */ 128 129 void inet_sock_destruct(struct sock *sk) 130 { 131 struct inet_sock *inet = inet_sk(sk); 132 133 __skb_queue_purge(&sk->sk_receive_queue); 134 __skb_queue_purge(&sk->sk_error_queue); 135 136 if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) { 137 printk("Attempt to release TCP socket in state %d %p\n", 138 sk->sk_state, sk); 139 return; 140 } 141 if (!sock_flag(sk, SOCK_DEAD)) { 142 printk("Attempt to release alive inet socket %p\n", sk); 143 return; 144 } 145 146 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); 147 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); 148 BUG_TRAP(!sk->sk_wmem_queued); 149 BUG_TRAP(!sk->sk_forward_alloc); 150 151 kfree(inet->opt); 152 dst_release(sk->sk_dst_cache); 153 sk_refcnt_debug_dec(sk); 154 } 155 156 /* 157 * The routines beyond this point handle the behaviour of an AF_INET 158 * socket object. Mostly it punts to the subprotocols of IP to do 159 * the work. 160 */ 161 162 /* 163 * Automatically bind an unbound socket. 164 */ 165 166 static int inet_autobind(struct sock *sk) 167 { 168 struct inet_sock *inet; 169 /* We may need to bind the socket. */ 170 lock_sock(sk); 171 inet = inet_sk(sk); 172 if (!inet->num) { 173 if (sk->sk_prot->get_port(sk, 0)) { 174 release_sock(sk); 175 return -EAGAIN; 176 } 177 inet->sport = htons(inet->num); 178 } 179 release_sock(sk); 180 return 0; 181 } 182 183 /* 184 * Move a socket into listening state. 185 */ 186 int inet_listen(struct socket *sock, int backlog) 187 { 188 struct sock *sk = sock->sk; 189 unsigned char old_state; 190 int err; 191 192 lock_sock(sk); 193 194 err = -EINVAL; 195 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM) 196 goto out; 197 198 old_state = sk->sk_state; 199 if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN))) 200 goto out; 201 202 /* Really, if the socket is already in listen state 203 * we can only allow the backlog to be adjusted. 204 */ 205 if (old_state != TCP_LISTEN) { 206 err = inet_csk_listen_start(sk, TCP_SYNQ_HSIZE); 207 if (err) 208 goto out; 209 } 210 sk->sk_max_ack_backlog = backlog; 211 err = 0; 212 213 out: 214 release_sock(sk); 215 return err; 216 } 217 218 /* 219 * Create an inet socket. 220 */ 221 222 static int inet_create(struct socket *sock, int protocol) 223 { 224 struct sock *sk; 225 struct list_head *p; 226 struct inet_protosw *answer; 227 struct inet_sock *inet; 228 struct proto *answer_prot; 229 unsigned char answer_flags; 230 char answer_no_check; 231 int try_loading_module = 0; 232 int err; 233 234 sock->state = SS_UNCONNECTED; 235 236 /* Look for the requested type/protocol pair. */ 237 answer = NULL; 238 lookup_protocol: 239 err = -ESOCKTNOSUPPORT; 240 rcu_read_lock(); 241 list_for_each_rcu(p, &inetsw[sock->type]) { 242 answer = list_entry(p, struct inet_protosw, list); 243 244 /* Check the non-wild match. */ 245 if (protocol == answer->protocol) { 246 if (protocol != IPPROTO_IP) 247 break; 248 } else { 249 /* Check for the two wild cases. */ 250 if (IPPROTO_IP == protocol) { 251 protocol = answer->protocol; 252 break; 253 } 254 if (IPPROTO_IP == answer->protocol) 255 break; 256 } 257 err = -EPROTONOSUPPORT; 258 answer = NULL; 259 } 260 261 if (unlikely(answer == NULL)) { 262 if (try_loading_module < 2) { 263 rcu_read_unlock(); 264 /* 265 * Be more specific, e.g. net-pf-2-proto-132-type-1 266 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM) 267 */ 268 if (++try_loading_module == 1) 269 request_module("net-pf-%d-proto-%d-type-%d", 270 PF_INET, protocol, sock->type); 271 /* 272 * Fall back to generic, e.g. net-pf-2-proto-132 273 * (net-pf-PF_INET-proto-IPPROTO_SCTP) 274 */ 275 else 276 request_module("net-pf-%d-proto-%d", 277 PF_INET, protocol); 278 goto lookup_protocol; 279 } else 280 goto out_rcu_unlock; 281 } 282 283 err = -EPERM; 284 if (answer->capability > 0 && !capable(answer->capability)) 285 goto out_rcu_unlock; 286 287 sock->ops = answer->ops; 288 answer_prot = answer->prot; 289 answer_no_check = answer->no_check; 290 answer_flags = answer->flags; 291 rcu_read_unlock(); 292 293 BUG_TRAP(answer_prot->slab != NULL); 294 295 err = -ENOBUFS; 296 sk = sk_alloc(PF_INET, GFP_KERNEL, answer_prot, 1); 297 if (sk == NULL) 298 goto out; 299 300 err = 0; 301 sk->sk_no_check = answer_no_check; 302 if (INET_PROTOSW_REUSE & answer_flags) 303 sk->sk_reuse = 1; 304 305 inet = inet_sk(sk); 306 inet->is_icsk = INET_PROTOSW_ICSK & answer_flags; 307 308 if (SOCK_RAW == sock->type) { 309 inet->num = protocol; 310 if (IPPROTO_RAW == protocol) 311 inet->hdrincl = 1; 312 } 313 314 if (ipv4_config.no_pmtu_disc) 315 inet->pmtudisc = IP_PMTUDISC_DONT; 316 else 317 inet->pmtudisc = IP_PMTUDISC_WANT; 318 319 inet->id = 0; 320 321 sock_init_data(sock, sk); 322 323 sk->sk_destruct = inet_sock_destruct; 324 sk->sk_family = PF_INET; 325 sk->sk_protocol = protocol; 326 sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv; 327 328 inet->uc_ttl = -1; 329 inet->mc_loop = 1; 330 inet->mc_ttl = 1; 331 inet->mc_index = 0; 332 inet->mc_list = NULL; 333 334 sk_refcnt_debug_inc(sk); 335 336 if (inet->num) { 337 /* It assumes that any protocol which allows 338 * the user to assign a number at socket 339 * creation time automatically 340 * shares. 341 */ 342 inet->sport = htons(inet->num); 343 /* Add to protocol hash chains. */ 344 sk->sk_prot->hash(sk); 345 } 346 347 if (sk->sk_prot->init) { 348 err = sk->sk_prot->init(sk); 349 if (err) 350 sk_common_release(sk); 351 } 352 out: 353 return err; 354 out_rcu_unlock: 355 rcu_read_unlock(); 356 goto out; 357 } 358 359 360 /* 361 * The peer socket should always be NULL (or else). When we call this 362 * function we are destroying the object and from then on nobody 363 * should refer to it. 364 */ 365 int inet_release(struct socket *sock) 366 { 367 struct sock *sk = sock->sk; 368 369 if (sk) { 370 long timeout; 371 372 /* Applications forget to leave groups before exiting */ 373 ip_mc_drop_socket(sk); 374 375 /* If linger is set, we don't return until the close 376 * is complete. Otherwise we return immediately. The 377 * actually closing is done the same either way. 378 * 379 * If the close is due to the process exiting, we never 380 * linger.. 381 */ 382 timeout = 0; 383 if (sock_flag(sk, SOCK_LINGER) && 384 !(current->flags & PF_EXITING)) 385 timeout = sk->sk_lingertime; 386 sock->sk = NULL; 387 sk->sk_prot->close(sk, timeout); 388 } 389 return 0; 390 } 391 392 /* It is off by default, see below. */ 393 int sysctl_ip_nonlocal_bind; 394 395 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 396 { 397 struct sockaddr_in *addr = (struct sockaddr_in *)uaddr; 398 struct sock *sk = sock->sk; 399 struct inet_sock *inet = inet_sk(sk); 400 unsigned short snum; 401 int chk_addr_ret; 402 int err; 403 404 /* If the socket has its own bind function then use it. (RAW) */ 405 if (sk->sk_prot->bind) { 406 err = sk->sk_prot->bind(sk, uaddr, addr_len); 407 goto out; 408 } 409 err = -EINVAL; 410 if (addr_len < sizeof(struct sockaddr_in)) 411 goto out; 412 413 chk_addr_ret = inet_addr_type(addr->sin_addr.s_addr); 414 415 /* Not specified by any standard per-se, however it breaks too 416 * many applications when removed. It is unfortunate since 417 * allowing applications to make a non-local bind solves 418 * several problems with systems using dynamic addressing. 419 * (ie. your servers still start up even if your ISDN link 420 * is temporarily down) 421 */ 422 err = -EADDRNOTAVAIL; 423 if (!sysctl_ip_nonlocal_bind && 424 !inet->freebind && 425 addr->sin_addr.s_addr != INADDR_ANY && 426 chk_addr_ret != RTN_LOCAL && 427 chk_addr_ret != RTN_MULTICAST && 428 chk_addr_ret != RTN_BROADCAST) 429 goto out; 430 431 snum = ntohs(addr->sin_port); 432 err = -EACCES; 433 if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE)) 434 goto out; 435 436 /* We keep a pair of addresses. rcv_saddr is the one 437 * used by hash lookups, and saddr is used for transmit. 438 * 439 * In the BSD API these are the same except where it 440 * would be illegal to use them (multicast/broadcast) in 441 * which case the sending device address is used. 442 */ 443 lock_sock(sk); 444 445 /* Check these errors (active socket, double bind). */ 446 err = -EINVAL; 447 if (sk->sk_state != TCP_CLOSE || inet->num) 448 goto out_release_sock; 449 450 inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr; 451 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) 452 inet->saddr = 0; /* Use device */ 453 454 /* Make sure we are allowed to bind here. */ 455 if (sk->sk_prot->get_port(sk, snum)) { 456 inet->saddr = inet->rcv_saddr = 0; 457 err = -EADDRINUSE; 458 goto out_release_sock; 459 } 460 461 if (inet->rcv_saddr) 462 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 463 if (snum) 464 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 465 inet->sport = htons(inet->num); 466 inet->daddr = 0; 467 inet->dport = 0; 468 sk_dst_reset(sk); 469 err = 0; 470 out_release_sock: 471 release_sock(sk); 472 out: 473 return err; 474 } 475 476 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr, 477 int addr_len, int flags) 478 { 479 struct sock *sk = sock->sk; 480 481 if (uaddr->sa_family == AF_UNSPEC) 482 return sk->sk_prot->disconnect(sk, flags); 483 484 if (!inet_sk(sk)->num && inet_autobind(sk)) 485 return -EAGAIN; 486 return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len); 487 } 488 489 static long inet_wait_for_connect(struct sock *sk, long timeo) 490 { 491 DEFINE_WAIT(wait); 492 493 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 494 495 /* Basic assumption: if someone sets sk->sk_err, he _must_ 496 * change state of the socket from TCP_SYN_*. 497 * Connect() does not allow to get error notifications 498 * without closing the socket. 499 */ 500 while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { 501 release_sock(sk); 502 timeo = schedule_timeout(timeo); 503 lock_sock(sk); 504 if (signal_pending(current) || !timeo) 505 break; 506 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 507 } 508 finish_wait(sk->sk_sleep, &wait); 509 return timeo; 510 } 511 512 /* 513 * Connect to a remote host. There is regrettably still a little 514 * TCP 'magic' in here. 515 */ 516 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, 517 int addr_len, int flags) 518 { 519 struct sock *sk = sock->sk; 520 int err; 521 long timeo; 522 523 lock_sock(sk); 524 525 if (uaddr->sa_family == AF_UNSPEC) { 526 err = sk->sk_prot->disconnect(sk, flags); 527 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; 528 goto out; 529 } 530 531 switch (sock->state) { 532 default: 533 err = -EINVAL; 534 goto out; 535 case SS_CONNECTED: 536 err = -EISCONN; 537 goto out; 538 case SS_CONNECTING: 539 err = -EALREADY; 540 /* Fall out of switch with err, set for this state */ 541 break; 542 case SS_UNCONNECTED: 543 err = -EISCONN; 544 if (sk->sk_state != TCP_CLOSE) 545 goto out; 546 547 err = sk->sk_prot->connect(sk, uaddr, addr_len); 548 if (err < 0) 549 goto out; 550 551 sock->state = SS_CONNECTING; 552 553 /* Just entered SS_CONNECTING state; the only 554 * difference is that return value in non-blocking 555 * case is EINPROGRESS, rather than EALREADY. 556 */ 557 err = -EINPROGRESS; 558 break; 559 } 560 561 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 562 563 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { 564 /* Error code is set above */ 565 if (!timeo || !inet_wait_for_connect(sk, timeo)) 566 goto out; 567 568 err = sock_intr_errno(timeo); 569 if (signal_pending(current)) 570 goto out; 571 } 572 573 /* Connection was closed by RST, timeout, ICMP error 574 * or another process disconnected us. 575 */ 576 if (sk->sk_state == TCP_CLOSE) 577 goto sock_error; 578 579 /* sk->sk_err may be not zero now, if RECVERR was ordered by user 580 * and error was received after socket entered established state. 581 * Hence, it is handled normally after connect() return successfully. 582 */ 583 584 sock->state = SS_CONNECTED; 585 err = 0; 586 out: 587 release_sock(sk); 588 return err; 589 590 sock_error: 591 err = sock_error(sk) ? : -ECONNABORTED; 592 sock->state = SS_UNCONNECTED; 593 if (sk->sk_prot->disconnect(sk, flags)) 594 sock->state = SS_DISCONNECTING; 595 goto out; 596 } 597 598 /* 599 * Accept a pending connection. The TCP layer now gives BSD semantics. 600 */ 601 602 int inet_accept(struct socket *sock, struct socket *newsock, int flags) 603 { 604 struct sock *sk1 = sock->sk; 605 int err = -EINVAL; 606 struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err); 607 608 if (!sk2) 609 goto do_err; 610 611 lock_sock(sk2); 612 613 BUG_TRAP((1 << sk2->sk_state) & 614 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)); 615 616 sock_graft(sk2, newsock); 617 618 newsock->state = SS_CONNECTED; 619 err = 0; 620 release_sock(sk2); 621 do_err: 622 return err; 623 } 624 625 626 /* 627 * This does both peername and sockname. 628 */ 629 int inet_getname(struct socket *sock, struct sockaddr *uaddr, 630 int *uaddr_len, int peer) 631 { 632 struct sock *sk = sock->sk; 633 struct inet_sock *inet = inet_sk(sk); 634 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; 635 636 sin->sin_family = AF_INET; 637 if (peer) { 638 if (!inet->dport || 639 (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) && 640 peer == 1)) 641 return -ENOTCONN; 642 sin->sin_port = inet->dport; 643 sin->sin_addr.s_addr = inet->daddr; 644 } else { 645 __u32 addr = inet->rcv_saddr; 646 if (!addr) 647 addr = inet->saddr; 648 sin->sin_port = inet->sport; 649 sin->sin_addr.s_addr = addr; 650 } 651 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 652 *uaddr_len = sizeof(*sin); 653 return 0; 654 } 655 656 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, 657 size_t size) 658 { 659 struct sock *sk = sock->sk; 660 661 /* We may need to bind the socket. */ 662 if (!inet_sk(sk)->num && inet_autobind(sk)) 663 return -EAGAIN; 664 665 return sk->sk_prot->sendmsg(iocb, sk, msg, size); 666 } 667 668 669 static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags) 670 { 671 struct sock *sk = sock->sk; 672 673 /* We may need to bind the socket. */ 674 if (!inet_sk(sk)->num && inet_autobind(sk)) 675 return -EAGAIN; 676 677 if (sk->sk_prot->sendpage) 678 return sk->sk_prot->sendpage(sk, page, offset, size, flags); 679 return sock_no_sendpage(sock, page, offset, size, flags); 680 } 681 682 683 int inet_shutdown(struct socket *sock, int how) 684 { 685 struct sock *sk = sock->sk; 686 int err = 0; 687 688 /* This should really check to make sure 689 * the socket is a TCP socket. (WHY AC...) 690 */ 691 how++; /* maps 0->1 has the advantage of making bit 1 rcvs and 692 1->2 bit 2 snds. 693 2->3 */ 694 if ((how & ~SHUTDOWN_MASK) || !how) /* MAXINT->0 */ 695 return -EINVAL; 696 697 lock_sock(sk); 698 if (sock->state == SS_CONNECTING) { 699 if ((1 << sk->sk_state) & 700 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)) 701 sock->state = SS_DISCONNECTING; 702 else 703 sock->state = SS_CONNECTED; 704 } 705 706 switch (sk->sk_state) { 707 case TCP_CLOSE: 708 err = -ENOTCONN; 709 /* Hack to wake up other listeners, who can poll for 710 POLLHUP, even on eg. unconnected UDP sockets -- RR */ 711 default: 712 sk->sk_shutdown |= how; 713 if (sk->sk_prot->shutdown) 714 sk->sk_prot->shutdown(sk, how); 715 break; 716 717 /* Remaining two branches are temporary solution for missing 718 * close() in multithreaded environment. It is _not_ a good idea, 719 * but we have no choice until close() is repaired at VFS level. 720 */ 721 case TCP_LISTEN: 722 if (!(how & RCV_SHUTDOWN)) 723 break; 724 /* Fall through */ 725 case TCP_SYN_SENT: 726 err = sk->sk_prot->disconnect(sk, O_NONBLOCK); 727 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; 728 break; 729 } 730 731 /* Wake up anyone sleeping in poll. */ 732 sk->sk_state_change(sk); 733 release_sock(sk); 734 return err; 735 } 736 737 /* 738 * ioctl() calls you can issue on an INET socket. Most of these are 739 * device configuration and stuff and very rarely used. Some ioctls 740 * pass on to the socket itself. 741 * 742 * NOTE: I like the idea of a module for the config stuff. ie ifconfig 743 * loads the devconfigure module does its configuring and unloads it. 744 * There's a good 20K of config code hanging around the kernel. 745 */ 746 747 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 748 { 749 struct sock *sk = sock->sk; 750 int err = 0; 751 752 switch (cmd) { 753 case SIOCGSTAMP: 754 err = sock_get_timestamp(sk, (struct timeval __user *)arg); 755 break; 756 case SIOCADDRT: 757 case SIOCDELRT: 758 case SIOCRTMSG: 759 err = ip_rt_ioctl(cmd, (void __user *)arg); 760 break; 761 case SIOCDARP: 762 case SIOCGARP: 763 case SIOCSARP: 764 err = arp_ioctl(cmd, (void __user *)arg); 765 break; 766 case SIOCGIFADDR: 767 case SIOCSIFADDR: 768 case SIOCGIFBRDADDR: 769 case SIOCSIFBRDADDR: 770 case SIOCGIFNETMASK: 771 case SIOCSIFNETMASK: 772 case SIOCGIFDSTADDR: 773 case SIOCSIFDSTADDR: 774 case SIOCSIFPFLAGS: 775 case SIOCGIFPFLAGS: 776 case SIOCSIFFLAGS: 777 err = devinet_ioctl(cmd, (void __user *)arg); 778 break; 779 default: 780 if (sk->sk_prot->ioctl) 781 err = sk->sk_prot->ioctl(sk, cmd, arg); 782 else 783 err = -ENOIOCTLCMD; 784 break; 785 } 786 return err; 787 } 788 789 const struct proto_ops inet_stream_ops = { 790 .family = PF_INET, 791 .owner = THIS_MODULE, 792 .release = inet_release, 793 .bind = inet_bind, 794 .connect = inet_stream_connect, 795 .socketpair = sock_no_socketpair, 796 .accept = inet_accept, 797 .getname = inet_getname, 798 .poll = tcp_poll, 799 .ioctl = inet_ioctl, 800 .listen = inet_listen, 801 .shutdown = inet_shutdown, 802 .setsockopt = sock_common_setsockopt, 803 .getsockopt = sock_common_getsockopt, 804 .sendmsg = inet_sendmsg, 805 .recvmsg = sock_common_recvmsg, 806 .mmap = sock_no_mmap, 807 .sendpage = tcp_sendpage 808 }; 809 810 const struct proto_ops inet_dgram_ops = { 811 .family = PF_INET, 812 .owner = THIS_MODULE, 813 .release = inet_release, 814 .bind = inet_bind, 815 .connect = inet_dgram_connect, 816 .socketpair = sock_no_socketpair, 817 .accept = sock_no_accept, 818 .getname = inet_getname, 819 .poll = udp_poll, 820 .ioctl = inet_ioctl, 821 .listen = sock_no_listen, 822 .shutdown = inet_shutdown, 823 .setsockopt = sock_common_setsockopt, 824 .getsockopt = sock_common_getsockopt, 825 .sendmsg = inet_sendmsg, 826 .recvmsg = sock_common_recvmsg, 827 .mmap = sock_no_mmap, 828 .sendpage = inet_sendpage, 829 }; 830 831 /* 832 * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without 833 * udp_poll 834 */ 835 static const struct proto_ops inet_sockraw_ops = { 836 .family = PF_INET, 837 .owner = THIS_MODULE, 838 .release = inet_release, 839 .bind = inet_bind, 840 .connect = inet_dgram_connect, 841 .socketpair = sock_no_socketpair, 842 .accept = sock_no_accept, 843 .getname = inet_getname, 844 .poll = datagram_poll, 845 .ioctl = inet_ioctl, 846 .listen = sock_no_listen, 847 .shutdown = inet_shutdown, 848 .setsockopt = sock_common_setsockopt, 849 .getsockopt = sock_common_getsockopt, 850 .sendmsg = inet_sendmsg, 851 .recvmsg = sock_common_recvmsg, 852 .mmap = sock_no_mmap, 853 .sendpage = inet_sendpage, 854 }; 855 856 static struct net_proto_family inet_family_ops = { 857 .family = PF_INET, 858 .create = inet_create, 859 .owner = THIS_MODULE, 860 }; 861 862 /* Upon startup we insert all the elements in inetsw_array[] into 863 * the linked list inetsw. 864 */ 865 static struct inet_protosw inetsw_array[] = 866 { 867 { 868 .type = SOCK_STREAM, 869 .protocol = IPPROTO_TCP, 870 .prot = &tcp_prot, 871 .ops = &inet_stream_ops, 872 .capability = -1, 873 .no_check = 0, 874 .flags = INET_PROTOSW_PERMANENT | 875 INET_PROTOSW_ICSK, 876 }, 877 878 { 879 .type = SOCK_DGRAM, 880 .protocol = IPPROTO_UDP, 881 .prot = &udp_prot, 882 .ops = &inet_dgram_ops, 883 .capability = -1, 884 .no_check = UDP_CSUM_DEFAULT, 885 .flags = INET_PROTOSW_PERMANENT, 886 }, 887 888 889 { 890 .type = SOCK_RAW, 891 .protocol = IPPROTO_IP, /* wild card */ 892 .prot = &raw_prot, 893 .ops = &inet_sockraw_ops, 894 .capability = CAP_NET_RAW, 895 .no_check = UDP_CSUM_DEFAULT, 896 .flags = INET_PROTOSW_REUSE, 897 } 898 }; 899 900 #define INETSW_ARRAY_LEN (sizeof(inetsw_array) / sizeof(struct inet_protosw)) 901 902 void inet_register_protosw(struct inet_protosw *p) 903 { 904 struct list_head *lh; 905 struct inet_protosw *answer; 906 int protocol = p->protocol; 907 struct list_head *last_perm; 908 909 spin_lock_bh(&inetsw_lock); 910 911 if (p->type >= SOCK_MAX) 912 goto out_illegal; 913 914 /* If we are trying to override a permanent protocol, bail. */ 915 answer = NULL; 916 last_perm = &inetsw[p->type]; 917 list_for_each(lh, &inetsw[p->type]) { 918 answer = list_entry(lh, struct inet_protosw, list); 919 920 /* Check only the non-wild match. */ 921 if (INET_PROTOSW_PERMANENT & answer->flags) { 922 if (protocol == answer->protocol) 923 break; 924 last_perm = lh; 925 } 926 927 answer = NULL; 928 } 929 if (answer) 930 goto out_permanent; 931 932 /* Add the new entry after the last permanent entry if any, so that 933 * the new entry does not override a permanent entry when matched with 934 * a wild-card protocol. But it is allowed to override any existing 935 * non-permanent entry. This means that when we remove this entry, the 936 * system automatically returns to the old behavior. 937 */ 938 list_add_rcu(&p->list, last_perm); 939 out: 940 spin_unlock_bh(&inetsw_lock); 941 942 synchronize_net(); 943 944 return; 945 946 out_permanent: 947 printk(KERN_ERR "Attempt to override permanent protocol %d.\n", 948 protocol); 949 goto out; 950 951 out_illegal: 952 printk(KERN_ERR 953 "Ignoring attempt to register invalid socket type %d.\n", 954 p->type); 955 goto out; 956 } 957 958 void inet_unregister_protosw(struct inet_protosw *p) 959 { 960 if (INET_PROTOSW_PERMANENT & p->flags) { 961 printk(KERN_ERR 962 "Attempt to unregister permanent protocol %d.\n", 963 p->protocol); 964 } else { 965 spin_lock_bh(&inetsw_lock); 966 list_del_rcu(&p->list); 967 spin_unlock_bh(&inetsw_lock); 968 969 synchronize_net(); 970 } 971 } 972 973 /* 974 * Shall we try to damage output packets if routing dev changes? 975 */ 976 977 int sysctl_ip_dynaddr; 978 979 static int inet_sk_reselect_saddr(struct sock *sk) 980 { 981 struct inet_sock *inet = inet_sk(sk); 982 int err; 983 struct rtable *rt; 984 __u32 old_saddr = inet->saddr; 985 __u32 new_saddr; 986 __u32 daddr = inet->daddr; 987 988 if (inet->opt && inet->opt->srr) 989 daddr = inet->opt->faddr; 990 991 /* Query new route. */ 992 err = ip_route_connect(&rt, daddr, 0, 993 RT_CONN_FLAGS(sk), 994 sk->sk_bound_dev_if, 995 sk->sk_protocol, 996 inet->sport, inet->dport, sk); 997 if (err) 998 return err; 999 1000 sk_setup_caps(sk, &rt->u.dst); 1001 1002 new_saddr = rt->rt_src; 1003 1004 if (new_saddr == old_saddr) 1005 return 0; 1006 1007 if (sysctl_ip_dynaddr > 1) { 1008 printk(KERN_INFO "%s(): shifting inet->" 1009 "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n", 1010 __FUNCTION__, 1011 NIPQUAD(old_saddr), 1012 NIPQUAD(new_saddr)); 1013 } 1014 1015 inet->saddr = inet->rcv_saddr = new_saddr; 1016 1017 /* 1018 * XXX The only one ugly spot where we need to 1019 * XXX really change the sockets identity after 1020 * XXX it has entered the hashes. -DaveM 1021 * 1022 * Besides that, it does not check for connection 1023 * uniqueness. Wait for troubles. 1024 */ 1025 __sk_prot_rehash(sk); 1026 return 0; 1027 } 1028 1029 int inet_sk_rebuild_header(struct sock *sk) 1030 { 1031 struct inet_sock *inet = inet_sk(sk); 1032 struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0); 1033 u32 daddr; 1034 int err; 1035 1036 /* Route is OK, nothing to do. */ 1037 if (rt) 1038 return 0; 1039 1040 /* Reroute. */ 1041 daddr = inet->daddr; 1042 if (inet->opt && inet->opt->srr) 1043 daddr = inet->opt->faddr; 1044 { 1045 struct flowi fl = { 1046 .oif = sk->sk_bound_dev_if, 1047 .nl_u = { 1048 .ip4_u = { 1049 .daddr = daddr, 1050 .saddr = inet->saddr, 1051 .tos = RT_CONN_FLAGS(sk), 1052 }, 1053 }, 1054 .proto = sk->sk_protocol, 1055 .uli_u = { 1056 .ports = { 1057 .sport = inet->sport, 1058 .dport = inet->dport, 1059 }, 1060 }, 1061 }; 1062 1063 err = ip_route_output_flow(&rt, &fl, sk, 0); 1064 } 1065 if (!err) 1066 sk_setup_caps(sk, &rt->u.dst); 1067 else { 1068 /* Routing failed... */ 1069 sk->sk_route_caps = 0; 1070 /* 1071 * Other protocols have to map its equivalent state to TCP_SYN_SENT. 1072 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme 1073 */ 1074 if (!sysctl_ip_dynaddr || 1075 sk->sk_state != TCP_SYN_SENT || 1076 (sk->sk_userlocks & SOCK_BINDADDR_LOCK) || 1077 (err = inet_sk_reselect_saddr(sk)) != 0) 1078 sk->sk_err_soft = -err; 1079 } 1080 1081 return err; 1082 } 1083 1084 EXPORT_SYMBOL(inet_sk_rebuild_header); 1085 1086 #ifdef CONFIG_IP_MULTICAST 1087 static struct net_protocol igmp_protocol = { 1088 .handler = igmp_rcv, 1089 }; 1090 #endif 1091 1092 static struct net_protocol tcp_protocol = { 1093 .handler = tcp_v4_rcv, 1094 .err_handler = tcp_v4_err, 1095 .no_policy = 1, 1096 }; 1097 1098 static struct net_protocol udp_protocol = { 1099 .handler = udp_rcv, 1100 .err_handler = udp_err, 1101 .no_policy = 1, 1102 }; 1103 1104 static struct net_protocol icmp_protocol = { 1105 .handler = icmp_rcv, 1106 }; 1107 1108 static int __init init_ipv4_mibs(void) 1109 { 1110 net_statistics[0] = alloc_percpu(struct linux_mib); 1111 net_statistics[1] = alloc_percpu(struct linux_mib); 1112 ip_statistics[0] = alloc_percpu(struct ipstats_mib); 1113 ip_statistics[1] = alloc_percpu(struct ipstats_mib); 1114 icmp_statistics[0] = alloc_percpu(struct icmp_mib); 1115 icmp_statistics[1] = alloc_percpu(struct icmp_mib); 1116 tcp_statistics[0] = alloc_percpu(struct tcp_mib); 1117 tcp_statistics[1] = alloc_percpu(struct tcp_mib); 1118 udp_statistics[0] = alloc_percpu(struct udp_mib); 1119 udp_statistics[1] = alloc_percpu(struct udp_mib); 1120 if (! 1121 (net_statistics[0] && net_statistics[1] && ip_statistics[0] 1122 && ip_statistics[1] && tcp_statistics[0] && tcp_statistics[1] 1123 && udp_statistics[0] && udp_statistics[1])) 1124 return -ENOMEM; 1125 1126 (void) tcp_mib_init(); 1127 1128 return 0; 1129 } 1130 1131 static int ipv4_proc_init(void); 1132 1133 /* 1134 * IP protocol layer initialiser 1135 */ 1136 1137 static struct packet_type ip_packet_type = { 1138 .type = __constant_htons(ETH_P_IP), 1139 .func = ip_rcv, 1140 }; 1141 1142 static int __init inet_init(void) 1143 { 1144 struct sk_buff *dummy_skb; 1145 struct inet_protosw *q; 1146 struct list_head *r; 1147 int rc = -EINVAL; 1148 1149 if (sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb)) { 1150 printk(KERN_CRIT "%s: panic\n", __FUNCTION__); 1151 goto out; 1152 } 1153 1154 rc = proto_register(&tcp_prot, 1); 1155 if (rc) 1156 goto out; 1157 1158 rc = proto_register(&udp_prot, 1); 1159 if (rc) 1160 goto out_unregister_tcp_proto; 1161 1162 rc = proto_register(&raw_prot, 1); 1163 if (rc) 1164 goto out_unregister_udp_proto; 1165 1166 /* 1167 * Tell SOCKET that we are alive... 1168 */ 1169 1170 (void)sock_register(&inet_family_ops); 1171 1172 /* 1173 * Add all the base protocols. 1174 */ 1175 1176 if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0) 1177 printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n"); 1178 if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0) 1179 printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n"); 1180 if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0) 1181 printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n"); 1182 #ifdef CONFIG_IP_MULTICAST 1183 if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0) 1184 printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n"); 1185 #endif 1186 1187 /* Register the socket-side information for inet_create. */ 1188 for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r) 1189 INIT_LIST_HEAD(r); 1190 1191 for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q) 1192 inet_register_protosw(q); 1193 1194 /* 1195 * Set the ARP module up 1196 */ 1197 1198 arp_init(); 1199 1200 /* 1201 * Set the IP module up 1202 */ 1203 1204 ip_init(); 1205 1206 tcp_v4_init(&inet_family_ops); 1207 1208 /* Setup TCP slab cache for open requests. */ 1209 tcp_init(); 1210 1211 1212 /* 1213 * Set the ICMP layer up 1214 */ 1215 1216 icmp_init(&inet_family_ops); 1217 1218 /* 1219 * Initialise the multicast router 1220 */ 1221 #if defined(CONFIG_IP_MROUTE) 1222 ip_mr_init(); 1223 #endif 1224 /* 1225 * Initialise per-cpu ipv4 mibs 1226 */ 1227 1228 if(init_ipv4_mibs()) 1229 printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n"); ; 1230 1231 ipv4_proc_init(); 1232 1233 ipfrag_init(); 1234 1235 dev_add_pack(&ip_packet_type); 1236 1237 rc = 0; 1238 out: 1239 return rc; 1240 out_unregister_tcp_proto: 1241 proto_unregister(&tcp_prot); 1242 out_unregister_udp_proto: 1243 proto_unregister(&udp_prot); 1244 goto out; 1245 } 1246 1247 module_init(inet_init); 1248 1249 /* ------------------------------------------------------------------------ */ 1250 1251 #ifdef CONFIG_PROC_FS 1252 static int __init ipv4_proc_init(void) 1253 { 1254 int rc = 0; 1255 1256 if (raw_proc_init()) 1257 goto out_raw; 1258 if (tcp4_proc_init()) 1259 goto out_tcp; 1260 if (udp4_proc_init()) 1261 goto out_udp; 1262 if (fib_proc_init()) 1263 goto out_fib; 1264 if (ip_misc_proc_init()) 1265 goto out_misc; 1266 out: 1267 return rc; 1268 out_misc: 1269 fib_proc_exit(); 1270 out_fib: 1271 udp4_proc_exit(); 1272 out_udp: 1273 tcp4_proc_exit(); 1274 out_tcp: 1275 raw_proc_exit(); 1276 out_raw: 1277 rc = -ENOMEM; 1278 goto out; 1279 } 1280 1281 #else /* CONFIG_PROC_FS */ 1282 static int __init ipv4_proc_init(void) 1283 { 1284 return 0; 1285 } 1286 #endif /* CONFIG_PROC_FS */ 1287 1288 MODULE_ALIAS_NETPROTO(PF_INET); 1289 1290 EXPORT_SYMBOL(inet_accept); 1291 EXPORT_SYMBOL(inet_bind); 1292 EXPORT_SYMBOL(inet_dgram_connect); 1293 EXPORT_SYMBOL(inet_dgram_ops); 1294 EXPORT_SYMBOL(inet_getname); 1295 EXPORT_SYMBOL(inet_ioctl); 1296 EXPORT_SYMBOL(inet_listen); 1297 EXPORT_SYMBOL(inet_register_protosw); 1298 EXPORT_SYMBOL(inet_release); 1299 EXPORT_SYMBOL(inet_sendmsg); 1300 EXPORT_SYMBOL(inet_shutdown); 1301 EXPORT_SYMBOL(inet_sock_destruct); 1302 EXPORT_SYMBOL(inet_stream_connect); 1303 EXPORT_SYMBOL(inet_stream_ops); 1304 EXPORT_SYMBOL(inet_unregister_protosw); 1305 EXPORT_SYMBOL(net_statistics); 1306 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind); 1307