net/ipv4/af_inet.c

   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  * Authors:     Ross Biro
   9  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  10  *              Florian La Roche, <flla@stud.uni-sb.de>
  11  *              Alan Cox, <A.Cox@swansea.ac.uk>
  12  *
  13  * Changes (see also sock.c)
  14  *
  15  *              piggy,
  16  *              Karl Knutson    :       Socket protocol table
  17  *              A.N.Kuznetsov   :       Socket death error in accept().
  18  *              John Richardson :       Fix non blocking error in connect()
  19  *                                      so sockets that fail to connect
  20  *                                      don't return -EINPROGRESS.
  21  *              Alan Cox        :       Asynchronous I/O support
  22  *              Alan Cox        :       Keep correct socket pointer on sock
  23  *                                      structures
  24  *                                      when accept() ed
  25  *              Alan Cox        :       Semantics of SO_LINGER aren't state
  26  *                                      moved to close when you look carefully.
  27  *                                      With this fixed and the accept bug fixed
  28  *                                      some RPC stuff seems happier.
  29  *              Niibe Yutaka    :       4.4BSD style write async I/O
  30  *              Alan Cox,
  31  *              Tony Gale       :       Fixed reuse semantics.
  32  *              Alan Cox        :       bind() shouldn't abort existing but dead
  33  *                                      sockets. Stops FTP netin:.. I hope.
  34  *              Alan Cox        :       bind() works correctly for RAW sockets.
  35  *                                      Note that FreeBSD at least was broken
  36  *                                      in this respect so be careful with
  37  *                                      compatibility tests...
  38  *              Alan Cox        :       routing cache support
  39  *              Alan Cox        :       memzero the socket structure for
  40  *                                      compactness.
  41  *              Matt Day        :       nonblock connect error handler
  42  *              Alan Cox        :       Allow large numbers of pending sockets
  43  *                                      (eg for big web sites), but only if
  44  *                                      specifically application requested.
  45  *              Alan Cox        :       New buffering throughout IP. Used
  46  *                                      dumbly.
  47  *              Alan Cox        :       New buffering now used smartly.
  48  *              Alan Cox        :       BSD rather than common sense
  49  *                                      interpretation of listen.
  50  *              Germano Caronni :       Assorted small races.
  51  *              Alan Cox        :       sendmsg/recvmsg basic support.
  52  *              Alan Cox        :       Only sendmsg/recvmsg now supported.
  53  *              Alan Cox        :       Locked down bind (see security list).
  54  *              Alan Cox        :       Loosened bind a little.
  55  *              Mike McLagan    :       ADD/DEL DLCI Ioctls
  56  *      Willy Konynenberg       :       Transparent proxying support.
  57  *              David S. Miller :       New socket lookup architecture.
  58  *                                      Some other random speedups.
  59  *              Cyrus Durgin    :       Cleaned up file for kmod hacks.
  60  *              Andi Kleen      :       Fix inet_stream_connect TCP race.
  61  *
  62  *              This program is free software; you can redistribute it and/or
  63  *              modify it under the terms of the GNU General Public License
  64  *              as published by the Free Software Foundation; either version
  65  *              2 of the License, or (at your option) any later version.
  66  */
  67
  68 #include <linux/err.h>
  69 #include <linux/errno.h>
  70 #include <linux/types.h>
  71 #include <linux/socket.h>
  72 #include <linux/in.h>
  73 #include <linux/kernel.h>
  74 #include <linux/module.h>
  75 #include <linux/sched.h>
  76 #include <linux/timer.h>
  77 #include <linux/string.h>
  78 #include <linux/sockios.h>
  79 #include <linux/net.h>
  80 #include <linux/capability.h>
  81 #include <linux/fcntl.h>
  82 #include <linux/mm.h>
  83 #include <linux/interrupt.h>
  84 #include <linux/stat.h>
  85 #include <linux/init.h>
  86 #include <linux/poll.h>
  87 #include <linux/netfilter_ipv4.h>
  88 #include <linux/random.h>
  89 #include <linux/slab.h>
  90
  91 #include <asm/uaccess.h>
  92 #include <asm/system.h>
  93
  94 #include <linux/inet.h>
  95 #include <linux/igmp.h>
  96 #include <linux/inetdevice.h>
  97 #include <linux/netdevice.h>
  98 #include <net/checksum.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 <net/ping.h>
 109 #include <linux/skbuff.h>
 110 #include <net/sock.h>
 111 #include <net/raw.h>
 112 #include <net/icmp.h>
 113 #include <net/ipip.h>
 114 #include <net/inet_common.h>
 115 #include <net/xfrm.h>
 116 #include <net/net_namespace.h>
 117 #ifdef CONFIG_IP_MROUTE
 118 #include <linux/mroute.h>
 119 #endif
 120
 121
 122 /* The inetsw table contains everything that inet_create needs to
 123  * build a new socket.
 124  */
 125 static struct list_head inetsw[SOCK_MAX];
 126 static DEFINE_SPINLOCK(inetsw_lock);
 127
 128 struct ipv4_config ipv4_config;
 129 EXPORT_SYMBOL(ipv4_config);
 130
 131 /* New destruction routine */
 132
 133 void inet_sock_destruct(struct sock *sk)
 134 {
 135         struct inet_sock *inet = inet_sk(sk);
 136
 137         __skb_queue_purge(&sk->sk_receive_queue);
 138         __skb_queue_purge(&sk->sk_error_queue);
 139
 140         sk_mem_reclaim(sk);
 141
 142         if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
 143                 pr_err("Attempt to release TCP socket in state %d %p\n",
 144                        sk->sk_state, sk);
 145                 return;
 146         }
 147         if (!sock_flag(sk, SOCK_DEAD)) {
 148                 pr_err("Attempt to release alive inet socket %p\n", sk);
 149                 return;
 150         }
 151
 152         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
 153         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
 154         WARN_ON(sk->sk_wmem_queued);
 155         WARN_ON(sk->sk_forward_alloc);
 156
 157         kfree(rcu_dereference_protected(inet->inet_opt, 1));
 158         dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
 159         sk_refcnt_debug_dec(sk);
 160 }
 161 EXPORT_SYMBOL(inet_sock_destruct);
 162
 163 /*
 164  *      The routines beyond this point handle the behaviour of an AF_INET
 165  *      socket object. Mostly it punts to the subprotocols of IP to do
 166  *      the work.
 167  */
 168
 169 /*
 170  *      Automatically bind an unbound socket.
 171  */
 172
 173 static int inet_autobind(struct sock *sk)
 174 {
 175         struct inet_sock *inet;
 176         /* We may need to bind the socket. */
 177         lock_sock(sk);
 178         inet = inet_sk(sk);
 179         if (!inet->inet_num) {
 180                 if (sk->sk_prot->get_port(sk, 0)) {
 181                         release_sock(sk);
 182                         return -EAGAIN;
 183                 }
 184                 inet->inet_sport = htons(inet->inet_num);
 185         }
 186         release_sock(sk);
 187         return 0;
 188 }
 189
 190 /*
 191  *      Move a socket into listening state.
 192  */
 193 int inet_listen(struct socket *sock, int backlog)
 194 {
 195         struct sock *sk = sock->sk;
 196         unsigned char old_state;
 197         int err;
 198
 199         lock_sock(sk);
 200
 201         err = -EINVAL;
 202         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
 203                 goto out;
 204
 205         old_state = sk->sk_state;
 206         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 207                 goto out;
 208
 209         /* Really, if the socket is already in listen state
 210          * we can only allow the backlog to be adjusted.
 211          */
 212         if (old_state != TCP_LISTEN) {
 213                 err = inet_csk_listen_start(sk, backlog);
 214                 if (err)
 215                         goto out;
 216         }
 217         sk->sk_max_ack_backlog = backlog;
 218         err = 0;
 219
 220 out:
 221         release_sock(sk);
 222         return err;
 223 }
 224 EXPORT_SYMBOL(inet_listen);
 225
 226 u32 inet_ehash_secret __read_mostly;
 227 EXPORT_SYMBOL(inet_ehash_secret);
 228
 229 /*
 230  * inet_ehash_secret must be set exactly once
 231  */
 232 void build_ehash_secret(void)
 233 {
 234         u32 rnd;
 235
 236         do {
 237                 get_random_bytes(&rnd, sizeof(rnd));
 238         } while (rnd == 0);
 239
 240         cmpxchg(&inet_ehash_secret, 0, rnd);
 241 }
 242 EXPORT_SYMBOL(build_ehash_secret);
 243
 244 static inline int inet_netns_ok(struct net *net, int protocol)
 245 {
 246         int hash;
 247         const struct net_protocol *ipprot;
 248
 249         if (net_eq(net, &init_net))
 250                 return 1;
 251
 252         hash = protocol & (MAX_INET_PROTOS - 1);
 253         ipprot = rcu_dereference(inet_protos[hash]);
 254
 255         if (ipprot == NULL)
 256                 /* raw IP is OK */
 257                 return 1;
 258         return ipprot->netns_ok;
 259 }
 260
 261 /*
 262  *      Create an inet socket.
 263  */
 264
 265 static int inet_create(struct net *net, struct socket *sock, int protocol,
 266                        int kern)
 267 {
 268         struct sock *sk;
 269         struct inet_protosw *answer;
 270         struct inet_sock *inet;
 271         struct proto *answer_prot;
 272         unsigned char answer_flags;
 273         char answer_no_check;
 274         int try_loading_module = 0;
 275         int err;
 276
 277         if (unlikely(!inet_ehash_secret))
 278                 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
 279                         build_ehash_secret();
 280
 281         sock->state = SS_UNCONNECTED;
 282
 283         /* Look for the requested type/protocol pair. */
 284 lookup_protocol:
 285         err = -ESOCKTNOSUPPORT;
 286         rcu_read_lock();
 287         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 288
 289                 err = 0;
 290                 /* Check the non-wild match. */
 291                 if (protocol == answer->protocol) {
 292                         if (protocol != IPPROTO_IP)
 293                                 break;
 294                 } else {
 295                         /* Check for the two wild cases. */
 296                         if (IPPROTO_IP == protocol) {
 297                                 protocol = answer->protocol;
 298                                 break;
 299                         }
 300                         if (IPPROTO_IP == answer->protocol)
 301                                 break;
 302                 }
 303                 err = -EPROTONOSUPPORT;
 304         }
 305
 306         if (unlikely(err)) {
 307                 if (try_loading_module < 2) {
 308                         rcu_read_unlock();
 309                         /*
 310                          * Be more specific, e.g. net-pf-2-proto-132-type-1
 311                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 312                          */
 313                         if (++try_loading_module == 1)
 314                                 request_module("net-pf-%d-proto-%d-type-%d",
 315                                                PF_INET, protocol, sock->type);
 316                         /*
 317                          * Fall back to generic, e.g. net-pf-2-proto-132
 318                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 319                          */
 320                         else
 321                                 request_module("net-pf-%d-proto-%d",
 322                                                PF_INET, protocol);
 323                         goto lookup_protocol;
 324                 } else
 325                         goto out_rcu_unlock;
 326         }
 327
 328         err = -EPERM;
 329         if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
 330                 goto out_rcu_unlock;
 331
 332         err = -EAFNOSUPPORT;
 333         if (!inet_netns_ok(net, protocol))
 334                 goto out_rcu_unlock;
 335
 336         sock->ops = answer->ops;
 337         answer_prot = answer->prot;
 338         answer_no_check = answer->no_check;
 339         answer_flags = answer->flags;
 340         rcu_read_unlock();
 341
 342         WARN_ON(answer_prot->slab == NULL);
 343
 344         err = -ENOBUFS;
 345         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
 346         if (sk == NULL)
 347                 goto out;
 348
 349         err = 0;
 350         sk->sk_no_check = answer_no_check;
 351         if (INET_PROTOSW_REUSE & answer_flags)
 352                 sk->sk_reuse = 1;
 353
 354         inet = inet_sk(sk);
 355         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 356
 357         inet->nodefrag = 0;
 358
 359         if (SOCK_RAW == sock->type) {
 360                 inet->inet_num = protocol;
 361                 if (IPPROTO_RAW == protocol)
 362                         inet->hdrincl = 1;
 363         }
 364
 365         if (ipv4_config.no_pmtu_disc)
 366                 inet->pmtudisc = IP_PMTUDISC_DONT;
 367         else
 368                 inet->pmtudisc = IP_PMTUDISC_WANT;
 369
 370         inet->inet_id = 0;
 371
 372         sock_init_data(sock, sk);
 373
 374         sk->sk_destruct    = inet_sock_destruct;
 375         sk->sk_protocol    = protocol;
 376         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 377
 378         inet->uc_ttl    = -1;
 379         inet->mc_loop   = 1;
 380         inet->mc_ttl    = 1;
 381         inet->mc_all    = 1;
 382         inet->mc_index  = 0;
 383         inet->mc_list   = NULL;
 384
 385         sk_refcnt_debug_inc(sk);
 386
 387         if (inet->inet_num) {
 388                 /* It assumes that any protocol which allows
 389                  * the user to assign a number at socket
 390                  * creation time automatically
 391                  * shares.
 392                  */
 393                 inet->inet_sport = htons(inet->inet_num);
 394                 /* Add to protocol hash chains. */
 395                 sk->sk_prot->hash(sk);
 396         }
 397
 398         if (sk->sk_prot->init) {
 399                 err = sk->sk_prot->init(sk);
 400                 if (err)
 401                         sk_common_release(sk);
 402         }
 403 out:
 404         return err;
 405 out_rcu_unlock:
 406         rcu_read_unlock();
 407         goto out;
 408 }
 409
 410
 411 /*
 412  *      The peer socket should always be NULL (or else). When we call this
 413  *      function we are destroying the object and from then on nobody
 414  *      should refer to it.
 415  */
 416 int inet_release(struct socket *sock)
 417 {
 418         struct sock *sk = sock->sk;
 419
 420         if (sk) {
 421                 long timeout;
 422
 423                 sock_rps_reset_flow(sk);
 424
 425                 /* Applications forget to leave groups before exiting */
 426                 ip_mc_drop_socket(sk);
 427
 428                 /* If linger is set, we don't return until the close
 429                  * is complete.  Otherwise we return immediately. The
 430                  * actually closing is done the same either way.
 431                  *
 432                  * If the close is due to the process exiting, we never
 433                  * linger..
 434                  */
 435                 timeout = 0;
 436                 if (sock_flag(sk, SOCK_LINGER) &&
 437                     !(current->flags & PF_EXITING))
 438                         timeout = sk->sk_lingertime;
 439                 sock->sk = NULL;
 440                 sk->sk_prot->close(sk, timeout);
 441         }
 442         return 0;
 443 }
 444 EXPORT_SYMBOL(inet_release);
 445
 446 /* It is off by default, see below. */
 447 int sysctl_ip_nonlocal_bind __read_mostly;
 448 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
 449
 450 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 451 {
 452         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 453         struct sock *sk = sock->sk;
 454         struct inet_sock *inet = inet_sk(sk);
 455         unsigned short snum;
 456         int chk_addr_ret;
 457         int err;
 458
 459         /* If the socket has its own bind function then use it. (RAW) */
 460         if (sk->sk_prot->bind) {
 461                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
 462                 goto out;
 463         }
 464         err = -EINVAL;
 465         if (addr_len < sizeof(struct sockaddr_in))
 466                 goto out;
 467
 468         chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
 469
 470         /* Not specified by any standard per-se, however it breaks too
 471          * many applications when removed.  It is unfortunate since
 472          * allowing applications to make a non-local bind solves
 473          * several problems with systems using dynamic addressing.
 474          * (ie. your servers still start up even if your ISDN link
 475          *  is temporarily down)
 476          */
 477         err = -EADDRNOTAVAIL;
 478         if (!sysctl_ip_nonlocal_bind &&
 479             !(inet->freebind || inet->transparent) &&
 480             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
 481             chk_addr_ret != RTN_LOCAL &&
 482             chk_addr_ret != RTN_MULTICAST &&
 483             chk_addr_ret != RTN_BROADCAST)
 484                 goto out;
 485
 486         snum = ntohs(addr->sin_port);
 487         err = -EACCES;
 488         if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
 489                 goto out;
 490
 491         /*      We keep a pair of addresses. rcv_saddr is the one
 492          *      used by hash lookups, and saddr is used for transmit.
 493          *
 494          *      In the BSD API these are the same except where it
 495          *      would be illegal to use them (multicast/broadcast) in
 496          *      which case the sending device address is used.
 497          */
 498         lock_sock(sk);
 499
 500         /* Check these errors (active socket, double bind). */
 501         err = -EINVAL;
 502         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
 503                 goto out_release_sock;
 504
 505         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
 506         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 507                 inet->inet_saddr = 0;  /* Use device */
 508
 509         /* Make sure we are allowed to bind here. */
 510         if (sk->sk_prot->get_port(sk, snum)) {
 511                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
 512                 err = -EADDRINUSE;
 513                 goto out_release_sock;
 514         }
 515
 516         if (inet->inet_rcv_saddr)
 517                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 518         if (snum)
 519                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 520         inet->inet_sport = htons(inet->inet_num);
 521         inet->inet_daddr = 0;
 522         inet->inet_dport = 0;
 523         sk_dst_reset(sk);
 524         err = 0;
 525 out_release_sock:
 526         release_sock(sk);
 527 out:
 528         return err;
 529 }
 530 EXPORT_SYMBOL(inet_bind);
 531
 532 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
 533                        int addr_len, int flags)
 534 {
 535         struct sock *sk = sock->sk;
 536
 537         if (addr_len < sizeof(uaddr->sa_family))
 538                 return -EINVAL;
 539         if (uaddr->sa_family == AF_UNSPEC)
 540                 return sk->sk_prot->disconnect(sk, flags);
 541
 542         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
 543                 return -EAGAIN;
 544         return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
 545 }
 546 EXPORT_SYMBOL(inet_dgram_connect);
 547
 548 static long inet_wait_for_connect(struct sock *sk, long timeo)
 549 {
 550         DEFINE_WAIT(wait);
 551
 552         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 553
 554         /* Basic assumption: if someone sets sk->sk_err, he _must_
 555          * change state of the socket from TCP_SYN_*.
 556          * Connect() does not allow to get error notifications
 557          * without closing the socket.
 558          */
 559         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 560                 release_sock(sk);
 561                 timeo = schedule_timeout(timeo);
 562                 lock_sock(sk);
 563                 if (signal_pending(current) || !timeo)
 564                         break;
 565                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 566         }
 567         finish_wait(sk_sleep(sk), &wait);
 568         return timeo;
 569 }
 570
 571 /*
 572  *      Connect to a remote host. There is regrettably still a little
 573  *      TCP 'magic' in here.
 574  */
 575 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 576                         int addr_len, int flags)
 577 {
 578         struct sock *sk = sock->sk;
 579         int err;
 580         long timeo;
 581
 582         if (addr_len < sizeof(uaddr->sa_family))
 583                 return -EINVAL;
 584
 585         lock_sock(sk);
 586
 587         if (uaddr->sa_family == AF_UNSPEC) {
 588                 err = sk->sk_prot->disconnect(sk, flags);
 589                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 590                 goto out;
 591         }
 592
 593         switch (sock->state) {
 594         default:
 595                 err = -EINVAL;
 596                 goto out;
 597         case SS_CONNECTED:
 598                 err = -EISCONN;
 599                 goto out;
 600         case SS_CONNECTING:
 601                 err = -EALREADY;
 602                 /* Fall out of switch with err, set for this state */
 603                 break;
 604         case SS_UNCONNECTED:
 605                 err = -EISCONN;
 606                 if (sk->sk_state != TCP_CLOSE)
 607                         goto out;
 608
 609                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
 610                 if (err < 0)
 611                         goto out;
 612
 613                 sock->state = SS_CONNECTING;
 614
 615                 /* Just entered SS_CONNECTING state; the only
 616                  * difference is that return value in non-blocking
 617                  * case is EINPROGRESS, rather than EALREADY.
 618                  */
 619                 err = -EINPROGRESS;
 620                 break;
 621         }
 622
 623         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 624
 625         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 626                 /* Error code is set above */
 627                 if (!timeo || !inet_wait_for_connect(sk, timeo))
 628                         goto out;
 629
 630                 err = sock_intr_errno(timeo);
 631                 if (signal_pending(current))
 632                         goto out;
 633         }
 634
 635         /* Connection was closed by RST, timeout, ICMP error
 636          * or another process disconnected us.
 637          */
 638         if (sk->sk_state == TCP_CLOSE)
 639                 goto sock_error;
 640
 641         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 642          * and error was received after socket entered established state.
 643          * Hence, it is handled normally after connect() return successfully.
 644          */
 645
 646         sock->state = SS_CONNECTED;
 647         err = 0;
 648 out:
 649         release_sock(sk);
 650         return err;
 651
 652 sock_error:
 653         err = sock_error(sk) ? : -ECONNABORTED;
 654         sock->state = SS_UNCONNECTED;
 655         if (sk->sk_prot->disconnect(sk, flags))
 656                 sock->state = SS_DISCONNECTING;
 657         goto out;
 658 }
 659 EXPORT_SYMBOL(inet_stream_connect);
 660
 661 /*
 662  *      Accept a pending connection. The TCP layer now gives BSD semantics.
 663  */
 664
 665 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
 666 {
 667         struct sock *sk1 = sock->sk;
 668         int err = -EINVAL;
 669         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
 670
 671         if (!sk2)
 672                 goto do_err;
 673
 674         lock_sock(sk2);
 675
 676         WARN_ON(!((1 << sk2->sk_state) &
 677                   (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 678
 679         sock_graft(sk2, newsock);
 680
 681         newsock->state = SS_CONNECTED;
 682         err = 0;
 683         release_sock(sk2);
 684 do_err:
 685         return err;
 686 }
 687 EXPORT_SYMBOL(inet_accept);
 688
 689
 690 /*
 691  *      This does both peername and sockname.
 692  */
 693 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 694                         int *uaddr_len, int peer)
 695 {
 696         struct sock *sk         = sock->sk;
 697         struct inet_sock *inet  = inet_sk(sk);
 698         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 699
 700         sin->sin_family = AF_INET;
 701         if (peer) {
 702                 if (!inet->inet_dport ||
 703                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 704                      peer == 1))
 705                         return -ENOTCONN;
 706                 sin->sin_port = inet->inet_dport;
 707                 sin->sin_addr.s_addr = inet->inet_daddr;
 708         } else {
 709                 __be32 addr = inet->inet_rcv_saddr;
 710                 if (!addr)
 711                         addr = inet->inet_saddr;
 712                 sin->sin_port = inet->inet_sport;
 713                 sin->sin_addr.s_addr = addr;
 714         }
 715         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 716         *uaddr_len = sizeof(*sin);
 717         return 0;
 718 }
 719 EXPORT_SYMBOL(inet_getname);
 720
 721 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 722                  size_t size)
 723 {
 724         struct sock *sk = sock->sk;
 725
 726         sock_rps_record_flow(sk);
 727
 728         /* We may need to bind the socket. */
 729         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 730             inet_autobind(sk))
 731                 return -EAGAIN;
 732
 733         return sk->sk_prot->sendmsg(iocb, sk, msg, size);
 734 }
 735 EXPORT_SYMBOL(inet_sendmsg);
 736
 737 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 738                       size_t size, int flags)
 739 {
 740         struct sock *sk = sock->sk;
 741
 742         sock_rps_record_flow(sk);
 743
 744         /* We may need to bind the socket. */
 745         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 746             inet_autobind(sk))
 747                 return -EAGAIN;
 748
 749         if (sk->sk_prot->sendpage)
 750                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
 751         return sock_no_sendpage(sock, page, offset, size, flags);
 752 }
 753 EXPORT_SYMBOL(inet_sendpage);
 754
 755 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 756                  size_t size, int flags)
 757 {
 758         struct sock *sk = sock->sk;
 759         int addr_len = 0;
 760         int err;
 761
 762         sock_rps_record_flow(sk);
 763
 764         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
 765                                    flags & ~MSG_DONTWAIT, &addr_len);
 766         if (err >= 0)
 767                 msg->msg_namelen = addr_len;
 768         return err;
 769 }
 770 EXPORT_SYMBOL(inet_recvmsg);
 771
 772 int inet_shutdown(struct socket *sock, int how)
 773 {
 774         struct sock *sk = sock->sk;
 775         int err = 0;
 776
 777         /* This should really check to make sure
 778          * the socket is a TCP socket. (WHY AC...)
 779          */
 780         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 781                        1->2 bit 2 snds.
 782                        2->3 */
 783         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 784                 return -EINVAL;
 785
 786         lock_sock(sk);
 787         if (sock->state == SS_CONNECTING) {
 788                 if ((1 << sk->sk_state) &
 789                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 790                         sock->state = SS_DISCONNECTING;
 791                 else
 792                         sock->state = SS_CONNECTED;
 793         }
 794
 795         switch (sk->sk_state) {
 796         case TCP_CLOSE:
 797                 err = -ENOTCONN;
 798                 /* Hack to wake up other listeners, who can poll for
 799                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
 800         default:
 801                 sk->sk_shutdown |= how;
 802                 if (sk->sk_prot->shutdown)
 803                         sk->sk_prot->shutdown(sk, how);
 804                 break;
 805
 806         /* Remaining two branches are temporary solution for missing
 807          * close() in multithreaded environment. It is _not_ a good idea,
 808          * but we have no choice until close() is repaired at VFS level.
 809          */
 810         case TCP_LISTEN:
 811                 if (!(how & RCV_SHUTDOWN))
 812                         break;
 813                 /* Fall through */
 814         case TCP_SYN_SENT:
 815                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 816                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 817                 break;
 818         }
 819
 820         /* Wake up anyone sleeping in poll. */
 821         sk->sk_state_change(sk);
 822         release_sock(sk);
 823         return err;
 824 }
 825 EXPORT_SYMBOL(inet_shutdown);
 826
 827 /*
 828  *      ioctl() calls you can issue on an INET socket. Most of these are
 829  *      device configuration and stuff and very rarely used. Some ioctls
 830  *      pass on to the socket itself.
 831  *
 832  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 833  *      loads the devconfigure module does its configuring and unloads it.
 834  *      There's a good 20K of config code hanging around the kernel.
 835  */
 836
 837 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 838 {
 839         struct sock *sk = sock->sk;
 840         int err = 0;
 841         struct net *net = sock_net(sk);
 842
 843         switch (cmd) {
 844         case SIOCGSTAMP:
 845                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
 846                 break;
 847         case SIOCGSTAMPNS:
 848                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
 849                 break;
 850         case SIOCADDRT:
 851         case SIOCDELRT:
 852         case SIOCRTMSG:
 853                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
 854                 break;
 855         case SIOCDARP:
 856         case SIOCGARP:
 857         case SIOCSARP:
 858                 err = arp_ioctl(net, cmd, (void __user *)arg);
 859                 break;
 860         case SIOCGIFADDR:
 861         case SIOCSIFADDR:
 862         case SIOCGIFBRDADDR:
 863         case SIOCSIFBRDADDR:
 864         case SIOCGIFNETMASK:
 865         case SIOCSIFNETMASK:
 866         case SIOCGIFDSTADDR:
 867         case SIOCSIFDSTADDR:
 868         case SIOCSIFPFLAGS:
 869         case SIOCGIFPFLAGS:
 870         case SIOCSIFFLAGS:
 871                 err = devinet_ioctl(net, cmd, (void __user *)arg);
 872                 break;
 873         default:
 874                 if (sk->sk_prot->ioctl)
 875                         err = sk->sk_prot->ioctl(sk, cmd, arg);
 876                 else
 877                         err = -ENOIOCTLCMD;
 878                 break;
 879         }
 880         return err;
 881 }
 882 EXPORT_SYMBOL(inet_ioctl);
 883
 884 #ifdef CONFIG_COMPAT
 885 int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 886 {
 887         struct sock *sk = sock->sk;
 888         int err = -ENOIOCTLCMD;
 889
 890         if (sk->sk_prot->compat_ioctl)
 891                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
 892
 893         return err;
 894 }
 895 #endif
 896
 897 const struct proto_ops inet_stream_ops = {
 898         .family            = PF_INET,
 899         .owner             = THIS_MODULE,
 900         .release           = inet_release,
 901         .bind              = inet_bind,
 902         .connect           = inet_stream_connect,
 903         .socketpair        = sock_no_socketpair,
 904         .accept            = inet_accept,
 905         .getname           = inet_getname,
 906         .poll              = tcp_poll,
 907         .ioctl             = inet_ioctl,
 908         .listen            = inet_listen,
 909         .shutdown          = inet_shutdown,
 910         .setsockopt        = sock_common_setsockopt,
 911         .getsockopt        = sock_common_getsockopt,
 912         .sendmsg           = inet_sendmsg,
 913         .recvmsg           = inet_recvmsg,
 914         .mmap              = sock_no_mmap,
 915         .sendpage          = inet_sendpage,
 916         .splice_read       = tcp_splice_read,
 917 #ifdef CONFIG_COMPAT
 918         .compat_setsockopt = compat_sock_common_setsockopt,
 919         .compat_getsockopt = compat_sock_common_getsockopt,
 920         .compat_ioctl      = inet_compat_ioctl,
 921 #endif
 922 };
 923 EXPORT_SYMBOL(inet_stream_ops);
 924
 925 const struct proto_ops inet_dgram_ops = {
 926         .family            = PF_INET,
 927         .owner             = THIS_MODULE,
 928         .release           = inet_release,
 929         .bind              = inet_bind,
 930         .connect           = inet_dgram_connect,
 931         .socketpair        = sock_no_socketpair,
 932         .accept            = sock_no_accept,
 933         .getname           = inet_getname,
 934         .poll              = udp_poll,
 935         .ioctl             = inet_ioctl,
 936         .listen            = sock_no_listen,
 937         .shutdown          = inet_shutdown,
 938         .setsockopt        = sock_common_setsockopt,
 939         .getsockopt        = sock_common_getsockopt,
 940         .sendmsg           = inet_sendmsg,
 941         .recvmsg           = inet_recvmsg,
 942         .mmap              = sock_no_mmap,
 943         .sendpage          = inet_sendpage,
 944 #ifdef CONFIG_COMPAT
 945         .compat_setsockopt = compat_sock_common_setsockopt,
 946         .compat_getsockopt = compat_sock_common_getsockopt,
 947         .compat_ioctl      = inet_compat_ioctl,
 948 #endif
 949 };
 950 EXPORT_SYMBOL(inet_dgram_ops);
 951
 952 /*
 953  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
 954  * udp_poll
 955  */
 956 static const struct proto_ops inet_sockraw_ops = {
 957         .family            = PF_INET,
 958         .owner             = THIS_MODULE,
 959         .release           = inet_release,
 960         .bind              = inet_bind,
 961         .connect           = inet_dgram_connect,
 962         .socketpair        = sock_no_socketpair,
 963         .accept            = sock_no_accept,
 964         .getname           = inet_getname,
 965         .poll              = datagram_poll,
 966         .ioctl             = inet_ioctl,
 967         .listen            = sock_no_listen,
 968         .shutdown          = inet_shutdown,
 969         .setsockopt        = sock_common_setsockopt,
 970         .getsockopt        = sock_common_getsockopt,
 971         .sendmsg           = inet_sendmsg,
 972         .recvmsg           = inet_recvmsg,
 973         .mmap              = sock_no_mmap,
 974         .sendpage          = inet_sendpage,
 975 #ifdef CONFIG_COMPAT
 976         .compat_setsockopt = compat_sock_common_setsockopt,
 977         .compat_getsockopt = compat_sock_common_getsockopt,
 978         .compat_ioctl      = inet_compat_ioctl,
 979 #endif
 980 };
 981
 982 static const struct net_proto_family inet_family_ops = {
 983         .family = PF_INET,
 984         .create = inet_create,
 985         .owner  = THIS_MODULE,
 986 };
 987
 988 /* Upon startup we insert all the elements in inetsw_array[] into
 989  * the linked list inetsw.
 990  */
 991 static struct inet_protosw inetsw_array[] =
 992 {
 993         {
 994                 .type =       SOCK_STREAM,
 995                 .protocol =   IPPROTO_TCP,
 996                 .prot =       &tcp_prot,
 997                 .ops =        &inet_stream_ops,
 998                 .no_check =   0,
 999                 .flags =      INET_PROTOSW_PERMANENT |
1000                               INET_PROTOSW_ICSK,
1001         },
1002
1003         {
1004                 .type =       SOCK_DGRAM,
1005                 .protocol =   IPPROTO_UDP,
1006                 .prot =       &udp_prot,
1007                 .ops =        &inet_dgram_ops,
1008                 .no_check =   UDP_CSUM_DEFAULT,
1009                 .flags =      INET_PROTOSW_PERMANENT,
1010        },
1011
1012        {
1013                 .type =       SOCK_DGRAM,
1014                 .protocol =   IPPROTO_ICMP,
1015                 .prot =       &ping_prot,
1016                 .ops =        &inet_dgram_ops,
1017                 .no_check =   UDP_CSUM_DEFAULT,
1018                 .flags =      INET_PROTOSW_REUSE,
1019        },
1020
1021        {
1022                .type =       SOCK_RAW,
1023                .protocol =   IPPROTO_IP,        /* wild card */
1024                .prot =       &raw_prot,
1025                .ops =        &inet_sockraw_ops,
1026                .no_check =   UDP_CSUM_DEFAULT,
1027                .flags =      INET_PROTOSW_REUSE,
1028        }
1029 };
1030
1031 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1032
1033 void inet_register_protosw(struct inet_protosw *p)
1034 {
1035         struct list_head *lh;
1036         struct inet_protosw *answer;
1037         int protocol = p->protocol;
1038         struct list_head *last_perm;
1039
1040         spin_lock_bh(&inetsw_lock);
1041
1042         if (p->type >= SOCK_MAX)
1043                 goto out_illegal;
1044
1045         /* If we are trying to override a permanent protocol, bail. */
1046         answer = NULL;
1047         last_perm = &inetsw[p->type];
1048         list_for_each(lh, &inetsw[p->type]) {
1049                 answer = list_entry(lh, struct inet_protosw, list);
1050
1051                 /* Check only the non-wild match. */
1052                 if (INET_PROTOSW_PERMANENT & answer->flags) {
1053                         if (protocol == answer->protocol)
1054                                 break;
1055                         last_perm = lh;
1056                 }
1057
1058                 answer = NULL;
1059         }
1060         if (answer)
1061                 goto out_permanent;
1062
1063         /* Add the new entry after the last permanent entry if any, so that
1064          * the new entry does not override a permanent entry when matched with
1065          * a wild-card protocol. But it is allowed to override any existing
1066          * non-permanent entry.  This means that when we remove this entry, the
1067          * system automatically returns to the old behavior.
1068          */
1069         list_add_rcu(&p->list, last_perm);
1070 out:
1071         spin_unlock_bh(&inetsw_lock);
1072
1073         return;
1074
1075 out_permanent:
1076         printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1077                protocol);
1078         goto out;
1079
1080 out_illegal:
1081         printk(KERN_ERR
1082                "Ignoring attempt to register invalid socket type %d.\n",
1083                p->type);
1084         goto out;
1085 }
1086 EXPORT_SYMBOL(inet_register_protosw);
1087
1088 void inet_unregister_protosw(struct inet_protosw *p)
1089 {
1090         if (INET_PROTOSW_PERMANENT & p->flags) {
1091                 printk(KERN_ERR
1092                        "Attempt to unregister permanent protocol %d.\n",
1093                        p->protocol);
1094         } else {
1095                 spin_lock_bh(&inetsw_lock);
1096                 list_del_rcu(&p->list);
1097                 spin_unlock_bh(&inetsw_lock);
1098
1099                 synchronize_net();
1100         }
1101 }
1102 EXPORT_SYMBOL(inet_unregister_protosw);
1103
1104 /*
1105  *      Shall we try to damage output packets if routing dev changes?
1106  */
1107
1108 int sysctl_ip_dynaddr __read_mostly;
1109
1110 static int inet_sk_reselect_saddr(struct sock *sk)
1111 {
1112         struct inet_sock *inet = inet_sk(sk);
1113         __be32 old_saddr = inet->inet_saddr;
1114         __be32 daddr = inet->inet_daddr;
1115         struct flowi4 *fl4;
1116         struct rtable *rt;
1117         __be32 new_saddr;
1118         struct ip_options_rcu *inet_opt;
1119
1120         inet_opt = rcu_dereference_protected(inet->inet_opt,
1121                                              sock_owned_by_user(sk));
1122         if (inet_opt && inet_opt->opt.srr)
1123                 daddr = inet_opt->opt.faddr;
1124
1125         /* Query new route. */
1126         fl4 = &inet->cork.fl.u.ip4;
1127         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1128                               sk->sk_bound_dev_if, sk->sk_protocol,
1129                               inet->inet_sport, inet->inet_dport, sk, false);
1130         if (IS_ERR(rt))
1131                 return PTR_ERR(rt);
1132
1133         sk_setup_caps(sk, &rt->dst);
1134
1135         new_saddr = fl4->saddr;
1136
1137         if (new_saddr == old_saddr)
1138                 return 0;
1139
1140         if (sysctl_ip_dynaddr > 1) {
1141                 printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1142                        __func__, &old_saddr, &new_saddr);
1143         }
1144
1145         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1146
1147         /*
1148          * XXX The only one ugly spot where we need to
1149          * XXX really change the sockets identity after
1150          * XXX it has entered the hashes. -DaveM
1151          *
1152          * Besides that, it does not check for connection
1153          * uniqueness. Wait for troubles.
1154          */
1155         __sk_prot_rehash(sk);
1156         return 0;
1157 }
1158
1159 int inet_sk_rebuild_header(struct sock *sk)
1160 {
1161         struct inet_sock *inet = inet_sk(sk);
1162         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1163         __be32 daddr;
1164         struct ip_options_rcu *inet_opt;
1165         struct flowi4 *fl4;
1166         int err;
1167
1168         /* Route is OK, nothing to do. */
1169         if (rt)
1170                 return 0;
1171
1172         /* Reroute. */
1173         rcu_read_lock();
1174         inet_opt = rcu_dereference(inet->inet_opt);
1175         daddr = inet->inet_daddr;
1176         if (inet_opt && inet_opt->opt.srr)
1177                 daddr = inet_opt->opt.faddr;
1178         rcu_read_unlock();
1179         fl4 = &inet->cork.fl.u.ip4;
1180         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1181                                    inet->inet_dport, inet->inet_sport,
1182                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1183                                    sk->sk_bound_dev_if);
1184         if (!IS_ERR(rt)) {
1185                 err = 0;
1186                 sk_setup_caps(sk, &rt->dst);
1187         } else {
1188                 err = PTR_ERR(rt);
1189
1190                 /* Routing failed... */
1191                 sk->sk_route_caps = 0;
1192                 /*
1193                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1194                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1195                  */
1196                 if (!sysctl_ip_dynaddr ||
1197                     sk->sk_state != TCP_SYN_SENT ||
1198                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1199                     (err = inet_sk_reselect_saddr(sk)) != 0)
1200                         sk->sk_err_soft = -err;
1201         }
1202
1203         return err;
1204 }
1205 EXPORT_SYMBOL(inet_sk_rebuild_header);
1206
1207 static int inet_gso_send_check(struct sk_buff *skb)
1208 {
1209         const struct iphdr *iph;
1210         const struct net_protocol *ops;
1211         int proto;
1212         int ihl;
1213         int err = -EINVAL;
1214
1215         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1216                 goto out;
1217
1218         iph = ip_hdr(skb);
1219         ihl = iph->ihl * 4;
1220         if (ihl < sizeof(*iph))
1221                 goto out;
1222
1223         if (unlikely(!pskb_may_pull(skb, ihl)))
1224                 goto out;
1225
1226         __skb_pull(skb, ihl);
1227         skb_reset_transport_header(skb);
1228         iph = ip_hdr(skb);
1229         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1230         err = -EPROTONOSUPPORT;
1231
1232         rcu_read_lock();
1233         ops = rcu_dereference(inet_protos[proto]);
1234         if (likely(ops && ops->gso_send_check))
1235                 err = ops->gso_send_check(skb);
1236         rcu_read_unlock();
1237
1238 out:
1239         return err;
1240 }
1241
1242 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, u32 features)
1243 {
1244         struct sk_buff *segs = ERR_PTR(-EINVAL);
1245         struct iphdr *iph;
1246         const struct net_protocol *ops;
1247         int proto;
1248         int ihl;
1249         int id;
1250         unsigned int offset = 0;
1251
1252         if (!(features & NETIF_F_V4_CSUM))
1253                 features &= ~NETIF_F_SG;
1254
1255         if (unlikely(skb_shinfo(skb)->gso_type &
1256                      ~(SKB_GSO_TCPV4 |
1257                        SKB_GSO_UDP |
1258                        SKB_GSO_DODGY |
1259                        SKB_GSO_TCP_ECN |
1260                        0)))
1261                 goto out;
1262
1263         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1264                 goto out;
1265
1266         iph = ip_hdr(skb);
1267         ihl = iph->ihl * 4;
1268         if (ihl < sizeof(*iph))
1269                 goto out;
1270
1271         if (unlikely(!pskb_may_pull(skb, ihl)))
1272                 goto out;
1273
1274         __skb_pull(skb, ihl);
1275         skb_reset_transport_header(skb);
1276         iph = ip_hdr(skb);
1277         id = ntohs(iph->id);
1278         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1279         segs = ERR_PTR(-EPROTONOSUPPORT);
1280
1281         rcu_read_lock();
1282         ops = rcu_dereference(inet_protos[proto]);
1283         if (likely(ops && ops->gso_segment))
1284                 segs = ops->gso_segment(skb, features);
1285         rcu_read_unlock();
1286
1287         if (!segs || IS_ERR(segs))
1288                 goto out;
1289
1290         skb = segs;
1291         do {
1292                 iph = ip_hdr(skb);
1293                 if (proto == IPPROTO_UDP) {
1294                         iph->id = htons(id);
1295                         iph->frag_off = htons(offset >> 3);
1296                         if (skb->next != NULL)
1297                                 iph->frag_off |= htons(IP_MF);
1298                         offset += (skb->len - skb->mac_len - iph->ihl * 4);
1299                 } else
1300                         iph->id = htons(id++);
1301                 iph->tot_len = htons(skb->len - skb->mac_len);
1302                 iph->check = 0;
1303                 iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1304         } while ((skb = skb->next));
1305
1306 out:
1307         return segs;
1308 }
1309
1310 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1311                                          struct sk_buff *skb)
1312 {
1313         const struct net_protocol *ops;
1314         struct sk_buff **pp = NULL;
1315         struct sk_buff *p;
1316         const struct iphdr *iph;
1317         unsigned int hlen;
1318         unsigned int off;
1319         unsigned int id;
1320         int flush = 1;
1321         int proto;
1322
1323         off = skb_gro_offset(skb);
1324         hlen = off + sizeof(*iph);
1325         iph = skb_gro_header_fast(skb, off);
1326         if (skb_gro_header_hard(skb, hlen)) {
1327                 iph = skb_gro_header_slow(skb, hlen, off);
1328                 if (unlikely(!iph))
1329                         goto out;
1330         }
1331
1332         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1333
1334         rcu_read_lock();
1335         ops = rcu_dereference(inet_protos[proto]);
1336         if (!ops || !ops->gro_receive)
1337                 goto out_unlock;
1338
1339         if (*(u8 *)iph != 0x45)
1340                 goto out_unlock;
1341
1342         if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1343                 goto out_unlock;
1344
1345         id = ntohl(*(__be32 *)&iph->id);
1346         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1347         id >>= 16;
1348
1349         for (p = *head; p; p = p->next) {
1350                 struct iphdr *iph2;
1351
1352                 if (!NAPI_GRO_CB(p)->same_flow)
1353                         continue;
1354
1355                 iph2 = ip_hdr(p);
1356
1357                 if ((iph->protocol ^ iph2->protocol) |
1358                     (iph->tos ^ iph2->tos) |
1359                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1360                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1361                         NAPI_GRO_CB(p)->same_flow = 0;
1362                         continue;
1363                 }
1364
1365                 /* All fields must match except length and checksum. */
1366                 NAPI_GRO_CB(p)->flush |=
1367                         (iph->ttl ^ iph2->ttl) |
1368                         ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1369
1370                 NAPI_GRO_CB(p)->flush |= flush;
1371         }
1372
1373         NAPI_GRO_CB(skb)->flush |= flush;
1374         skb_gro_pull(skb, sizeof(*iph));
1375         skb_set_transport_header(skb, skb_gro_offset(skb));
1376
1377         pp = ops->gro_receive(head, skb);
1378
1379 out_unlock:
1380         rcu_read_unlock();
1381
1382 out:
1383         NAPI_GRO_CB(skb)->flush |= flush;
1384
1385         return pp;
1386 }
1387
1388 static int inet_gro_complete(struct sk_buff *skb)
1389 {
1390         const struct net_protocol *ops;
1391         struct iphdr *iph = ip_hdr(skb);
1392         int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1393         int err = -ENOSYS;
1394         __be16 newlen = htons(skb->len - skb_network_offset(skb));
1395
1396         csum_replace2(&iph->check, iph->tot_len, newlen);
1397         iph->tot_len = newlen;
1398
1399         rcu_read_lock();
1400         ops = rcu_dereference(inet_protos[proto]);
1401         if (WARN_ON(!ops || !ops->gro_complete))
1402                 goto out_unlock;
1403
1404         err = ops->gro_complete(skb);
1405
1406 out_unlock:
1407         rcu_read_unlock();
1408
1409         return err;
1410 }
1411
1412 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1413                          unsigned short type, unsigned char protocol,
1414                          struct net *net)
1415 {
1416         struct socket *sock;
1417         int rc = sock_create_kern(family, type, protocol, &sock);
1418
1419         if (rc == 0) {
1420                 *sk = sock->sk;
1421                 (*sk)->sk_allocation = GFP_ATOMIC;
1422                 /*
1423                  * Unhash it so that IP input processing does not even see it,
1424                  * we do not wish this socket to see incoming packets.
1425                  */
1426                 (*sk)->sk_prot->unhash(*sk);
1427
1428                 sk_change_net(*sk, net);
1429         }
1430         return rc;
1431 }
1432 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1433
1434 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1435 {
1436         unsigned long res = 0;
1437         int i;
1438
1439         for_each_possible_cpu(i) {
1440                 res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1441                 res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1442         }
1443         return res;
1444 }
1445 EXPORT_SYMBOL_GPL(snmp_fold_field);
1446
1447 #if BITS_PER_LONG==32
1448
1449 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1450 {
1451         u64 res = 0;
1452         int cpu;
1453
1454         for_each_possible_cpu(cpu) {
1455                 void *bhptr, *userptr;
1456                 struct u64_stats_sync *syncp;
1457                 u64 v_bh, v_user;
1458                 unsigned int start;
1459
1460                 /* first mib used by softirq context, we must use _bh() accessors */
1461                 bhptr = per_cpu_ptr(SNMP_STAT_BHPTR(mib), cpu);
1462                 syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1463                 do {
1464                         start = u64_stats_fetch_begin_bh(syncp);
1465                         v_bh = *(((u64 *) bhptr) + offt);
1466                 } while (u64_stats_fetch_retry_bh(syncp, start));
1467
1468                 /* second mib used in USER context */
1469                 userptr = per_cpu_ptr(SNMP_STAT_USRPTR(mib), cpu);
1470                 syncp = (struct u64_stats_sync *)(userptr + syncp_offset);
1471                 do {
1472                         start = u64_stats_fetch_begin(syncp);
1473                         v_user = *(((u64 *) userptr) + offt);
1474                 } while (u64_stats_fetch_retry(syncp, start));
1475
1476                 res += v_bh + v_user;
1477         }
1478         return res;
1479 }
1480 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1481 #endif
1482
1483 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1484 {
1485         BUG_ON(ptr == NULL);
1486         ptr[0] = __alloc_percpu(mibsize, align);
1487         if (!ptr[0])
1488                 goto err0;
1489         ptr[1] = __alloc_percpu(mibsize, align);
1490         if (!ptr[1])
1491                 goto err1;
1492         return 0;
1493 err1:
1494         free_percpu(ptr[0]);
1495         ptr[0] = NULL;
1496 err0:
1497         return -ENOMEM;
1498 }
1499 EXPORT_SYMBOL_GPL(snmp_mib_init);
1500
1501 void snmp_mib_free(void __percpu *ptr[2])
1502 {
1503         BUG_ON(ptr == NULL);
1504         free_percpu(ptr[0]);
1505         free_percpu(ptr[1]);
1506         ptr[0] = ptr[1] = NULL;
1507 }
1508 EXPORT_SYMBOL_GPL(snmp_mib_free);
1509
1510 #ifdef CONFIG_IP_MULTICAST
1511 static const struct net_protocol igmp_protocol = {
1512         .handler =      igmp_rcv,
1513         .netns_ok =     1,
1514 };
1515 #endif
1516
1517 static const struct net_protocol tcp_protocol = {
1518         .handler =      tcp_v4_rcv,
1519         .err_handler =  tcp_v4_err,
1520         .gso_send_check = tcp_v4_gso_send_check,
1521         .gso_segment =  tcp_tso_segment,
1522         .gro_receive =  tcp4_gro_receive,
1523         .gro_complete = tcp4_gro_complete,
1524         .no_policy =    1,
1525         .netns_ok =     1,
1526 };
1527
1528 static const struct net_protocol udp_protocol = {
1529         .handler =      udp_rcv,
1530         .err_handler =  udp_err,
1531         .gso_send_check = udp4_ufo_send_check,
1532         .gso_segment = udp4_ufo_fragment,
1533         .no_policy =    1,
1534         .netns_ok =     1,
1535 };
1536
1537 static const struct net_protocol icmp_protocol = {
1538         .handler =      icmp_rcv,
1539         .err_handler =  ping_err,
1540         .no_policy =    1,
1541         .netns_ok =     1,
1542 };
1543
1544 static __net_init int ipv4_mib_init_net(struct net *net)
1545 {
1546         if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1547                           sizeof(struct tcp_mib),
1548                           __alignof__(struct tcp_mib)) < 0)
1549                 goto err_tcp_mib;
1550         if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1551                           sizeof(struct ipstats_mib),
1552                           __alignof__(struct ipstats_mib)) < 0)
1553                 goto err_ip_mib;
1554         if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1555                           sizeof(struct linux_mib),
1556                           __alignof__(struct linux_mib)) < 0)
1557                 goto err_net_mib;
1558         if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1559                           sizeof(struct udp_mib),
1560                           __alignof__(struct udp_mib)) < 0)
1561                 goto err_udp_mib;
1562         if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1563                           sizeof(struct udp_mib),
1564                           __alignof__(struct udp_mib)) < 0)
1565                 goto err_udplite_mib;
1566         if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1567                           sizeof(struct icmp_mib),
1568                           __alignof__(struct icmp_mib)) < 0)
1569                 goto err_icmp_mib;
1570         if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
1571                           sizeof(struct icmpmsg_mib),
1572                           __alignof__(struct icmpmsg_mib)) < 0)
1573                 goto err_icmpmsg_mib;
1574
1575         tcp_mib_init(net);
1576         return 0;
1577
1578 err_icmpmsg_mib:
1579         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1580 err_icmp_mib:
1581         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1582 err_udplite_mib:
1583         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1584 err_udp_mib:
1585         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1586 err_net_mib:
1587         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1588 err_ip_mib:
1589         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1590 err_tcp_mib:
1591         return -ENOMEM;
1592 }
1593
1594 static __net_exit void ipv4_mib_exit_net(struct net *net)
1595 {
1596         snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
1597         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1598         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1599         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1600         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1601         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1602         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1603 }
1604
1605 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1606         .init = ipv4_mib_init_net,
1607         .exit = ipv4_mib_exit_net,
1608 };
1609
1610 static int __init init_ipv4_mibs(void)
1611 {
1612         return register_pernet_subsys(&ipv4_mib_ops);
1613 }
1614
1615 static int ipv4_proc_init(void);
1616
1617 /*
1618  *      IP protocol layer initialiser
1619  */
1620
1621 static struct packet_type ip_packet_type __read_mostly = {
1622         .type = cpu_to_be16(ETH_P_IP),
1623         .func = ip_rcv,
1624         .gso_send_check = inet_gso_send_check,
1625         .gso_segment = inet_gso_segment,
1626         .gro_receive = inet_gro_receive,
1627         .gro_complete = inet_gro_complete,
1628 };
1629
1630 static int __init inet_init(void)
1631 {
1632         struct sk_buff *dummy_skb;
1633         struct inet_protosw *q;
1634         struct list_head *r;
1635         int rc = -EINVAL;
1636
1637         BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1638
1639         sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1640         if (!sysctl_local_reserved_ports)
1641                 goto out;
1642
1643         rc = proto_register(&tcp_prot, 1);
1644         if (rc)
1645                 goto out_free_reserved_ports;
1646
1647         rc = proto_register(&udp_prot, 1);
1648         if (rc)
1649                 goto out_unregister_tcp_proto;
1650
1651         rc = proto_register(&raw_prot, 1);
1652         if (rc)
1653                 goto out_unregister_udp_proto;
1654
1655         rc = proto_register(&ping_prot, 1);
1656         if (rc)
1657                 goto out_unregister_raw_proto;
1658
1659         /*
1660          *      Tell SOCKET that we are alive...
1661          */
1662
1663         (void)sock_register(&inet_family_ops);
1664
1665 #ifdef CONFIG_SYSCTL
1666         ip_static_sysctl_init();
1667 #endif
1668
1669         /*
1670          *      Add all the base protocols.
1671          */
1672
1673         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1674                 printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1675         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1676                 printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1677         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1678                 printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1679 #ifdef CONFIG_IP_MULTICAST
1680         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1681                 printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1682 #endif
1683
1684         /* Register the socket-side information for inet_create. */
1685         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1686                 INIT_LIST_HEAD(r);
1687
1688         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1689                 inet_register_protosw(q);
1690
1691         /*
1692          *      Set the ARP module up
1693          */
1694
1695         arp_init();
1696
1697         /*
1698          *      Set the IP module up
1699          */
1700
1701         ip_init();
1702
1703         tcp_v4_init();
1704
1705         /* Setup TCP slab cache for open requests. */
1706         tcp_init();
1707
1708         /* Setup UDP memory threshold */
1709         udp_init();
1710
1711         /* Add UDP-Lite (RFC 3828) */
1712         udplite4_register();
1713
1714         ping_init();
1715
1716         /*
1717          *      Set the ICMP layer up
1718          */
1719
1720         if (icmp_init() < 0)
1721                 panic("Failed to create the ICMP control socket.\n");
1722
1723         /*
1724          *      Initialise the multicast router
1725          */
1726 #if defined(CONFIG_IP_MROUTE)
1727         if (ip_mr_init())
1728                 printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1729 #endif
1730         /*
1731          *      Initialise per-cpu ipv4 mibs
1732          */
1733
1734         if (init_ipv4_mibs())
1735                 printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1736
1737         ipv4_proc_init();
1738
1739         ipfrag_init();
1740
1741         dev_add_pack(&ip_packet_type);
1742
1743         rc = 0;
1744 out:
1745         return rc;
1746 out_unregister_raw_proto:
1747         proto_unregister(&raw_prot);
1748 out_unregister_udp_proto:
1749         proto_unregister(&udp_prot);
1750 out_unregister_tcp_proto:
1751         proto_unregister(&tcp_prot);
1752 out_free_reserved_ports:
1753         kfree(sysctl_local_reserved_ports);
1754         goto out;
1755 }
1756
1757 fs_initcall(inet_init);
1758
1759 /* ------------------------------------------------------------------------ */
1760
1761 #ifdef CONFIG_PROC_FS
1762 static int __init ipv4_proc_init(void)
1763 {
1764         int rc = 0;
1765
1766         if (raw_proc_init())
1767                 goto out_raw;
1768         if (tcp4_proc_init())
1769                 goto out_tcp;
1770         if (udp4_proc_init())
1771                 goto out_udp;
1772         if (ping_proc_init())
1773                 goto out_ping;
1774         if (ip_misc_proc_init())
1775                 goto out_misc;
1776 out:
1777         return rc;
1778 out_misc:
1779         ping_proc_exit();
1780 out_ping:
1781         udp4_proc_exit();
1782 out_udp:
1783         tcp4_proc_exit();
1784 out_tcp:
1785         raw_proc_exit();
1786 out_raw:
1787         rc = -ENOMEM;
1788         goto out;
1789 }
1790
1791 #else /* CONFIG_PROC_FS */
1792 static int __init ipv4_proc_init(void)
1793 {
1794         return 0;
1795 }
1796 #endif /* CONFIG_PROC_FS */
1797
1798 MODULE_ALIAS_NETPROTO(PF_INET);
1799