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