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 #define pr_fmt(fmt) "IPv4: " fmt
  69
  70 #include <linux/err.h>
  71 #include <linux/errno.h>
  72 #include <linux/types.h>
  73 #include <linux/socket.h>
  74 #include <linux/in.h>
  75 #include <linux/kernel.h>
  76 #include <linux/module.h>
  77 #include <linux/sched.h>
  78 #include <linux/timer.h>
  79 #include <linux/string.h>
  80 #include <linux/sockios.h>
  81 #include <linux/net.h>
  82 #include <linux/capability.h>
  83 #include <linux/fcntl.h>
  84 #include <linux/mm.h>
  85 #include <linux/interrupt.h>
  86 #include <linux/stat.h>
  87 #include <linux/init.h>
  88 #include <linux/poll.h>
  89 #include <linux/netfilter_ipv4.h>
  90 #include <linux/random.h>
  91 #include <linux/slab.h>
  92
  93 #include <asm/uaccess.h>
  94
  95 #include <linux/inet.h>
  96 #include <linux/igmp.h>
  97 #include <linux/inetdevice.h>
  98 #include <linux/netdevice.h>
  99 #include <net/checksum.h>
 100 #include <net/ip.h>
 101 #include <net/protocol.h>
 102 #include <net/arp.h>
 103 #include <net/route.h>
 104 #include <net/ip_fib.h>
 105 #include <net/inet_connection_sock.h>
 106 #include <net/tcp.h>
 107 #include <net/udp.h>
 108 #include <net/udplite.h>
 109 #include <net/ping.h>
 110 #include <linux/skbuff.h>
 111 #include <net/sock.h>
 112 #include <net/raw.h>
 113 #include <net/icmp.h>
 114 #include <net/ipip.h>
 115 #include <net/inet_common.h>
 116 #include <net/xfrm.h>
 117 #include <net/net_namespace.h>
 118 #ifdef CONFIG_IP_MROUTE
 119 #include <linux/mroute.h>
 120 #endif
 121
 122
 123 /* The inetsw table contains everything that inet_create needs to
 124  * build a new socket.
 125  */
 126 static struct list_head inetsw[SOCK_MAX];
 127 static DEFINE_SPINLOCK(inetsw_lock);
 128
 129 struct ipv4_config ipv4_config;
 130 EXPORT_SYMBOL(ipv4_config);
 131
 132 /* New destruction routine */
 133
 134 void inet_sock_destruct(struct sock *sk)
 135 {
 136         struct inet_sock *inet = inet_sk(sk);
 137
 138         __skb_queue_purge(&sk->sk_receive_queue);
 139         __skb_queue_purge(&sk->sk_error_queue);
 140
 141         sk_mem_reclaim(sk);
 142
 143         if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
 144                 pr_err("Attempt to release TCP socket in state %d %p\n",
 145                        sk->sk_state, sk);
 146                 return;
 147         }
 148         if (!sock_flag(sk, SOCK_DEAD)) {
 149                 pr_err("Attempt to release alive inet socket %p\n", sk);
 150                 return;
 151         }
 152
 153         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
 154         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
 155         WARN_ON(sk->sk_wmem_queued);
 156         WARN_ON(sk->sk_forward_alloc);
 157
 158         kfree(rcu_dereference_protected(inet->inet_opt, 1));
 159         dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
 160         sk_refcnt_debug_dec(sk);
 161 }
 162 EXPORT_SYMBOL(inet_sock_destruct);
 163
 164 /*
 165  *      The routines beyond this point handle the behaviour of an AF_INET
 166  *      socket object. Mostly it punts to the subprotocols of IP to do
 167  *      the work.
 168  */
 169
 170 /*
 171  *      Automatically bind an unbound socket.
 172  */
 173
 174 static int inet_autobind(struct sock *sk)
 175 {
 176         struct inet_sock *inet;
 177         /* We may need to bind the socket. */
 178         lock_sock(sk);
 179         inet = inet_sk(sk);
 180         if (!inet->inet_num) {
 181                 if (sk->sk_prot->get_port(sk, 0)) {
 182                         release_sock(sk);
 183                         return -EAGAIN;
 184                 }
 185                 inet->inet_sport = htons(inet->inet_num);
 186         }
 187         release_sock(sk);
 188         return 0;
 189 }
 190
 191 /*
 192  *      Move a socket into listening state.
 193  */
 194 int inet_listen(struct socket *sock, int backlog)
 195 {
 196         struct sock *sk = sock->sk;
 197         unsigned char old_state;
 198         int err;
 199
 200         lock_sock(sk);
 201
 202         err = -EINVAL;
 203         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
 204                 goto out;
 205
 206         old_state = sk->sk_state;
 207         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 208                 goto out;
 209
 210         /* Really, if the socket is already in listen state
 211          * we can only allow the backlog to be adjusted.
 212          */
 213         if (old_state != TCP_LISTEN) {
 214                 err = inet_csk_listen_start(sk, backlog);
 215                 if (err)
 216                         goto out;
 217         }
 218         sk->sk_max_ack_backlog = backlog;
 219         err = 0;
 220
 221 out:
 222         release_sock(sk);
 223         return err;
 224 }
 225 EXPORT_SYMBOL(inet_listen);
 226
 227 u32 inet_ehash_secret __read_mostly;
 228 EXPORT_SYMBOL(inet_ehash_secret);
 229
 230 /*
 231  * inet_ehash_secret must be set exactly once
 232  */
 233 void build_ehash_secret(void)
 234 {
 235         u32 rnd;
 236
 237         do {
 238                 get_random_bytes(&rnd, sizeof(rnd));
 239         } while (rnd == 0);
 240
 241         cmpxchg(&inet_ehash_secret, 0, rnd);
 242 }
 243 EXPORT_SYMBOL(build_ehash_secret);
 244
 245 static inline int inet_netns_ok(struct net *net, int protocol)
 246 {
 247         int hash;
 248         const struct net_protocol *ipprot;
 249
 250         if (net_eq(net, &init_net))
 251                 return 1;
 252
 253         hash = protocol & (MAX_INET_PROTOS - 1);
 254         ipprot = rcu_dereference(inet_protos[hash]);
 255
 256         if (ipprot == NULL)
 257                 /* raw IP is OK */
 258                 return 1;
 259         return ipprot->netns_ok;
 260 }
 261
 262 /*
 263  *      Create an inet socket.
 264  */
 265
 266 static int inet_create(struct net *net, struct socket *sock, int protocol,
 267                        int kern)
 268 {
 269         struct sock *sk;
 270         struct inet_protosw *answer;
 271         struct inet_sock *inet;
 272         struct proto *answer_prot;
 273         unsigned char answer_flags;
 274         char answer_no_check;
 275         int try_loading_module = 0;
 276         int err;
 277
 278         if (unlikely(!inet_ehash_secret))
 279                 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
 280                         build_ehash_secret();
 281
 282         sock->state = SS_UNCONNECTED;
 283
 284         /* Look for the requested type/protocol pair. */
 285 lookup_protocol:
 286         err = -ESOCKTNOSUPPORT;
 287         rcu_read_lock();
 288         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 289
 290                 err = 0;
 291                 /* Check the non-wild match. */
 292                 if (protocol == answer->protocol) {
 293                         if (protocol != IPPROTO_IP)
 294                                 break;
 295                 } else {
 296                         /* Check for the two wild cases. */
 297                         if (IPPROTO_IP == protocol) {
 298                                 protocol = answer->protocol;
 299                                 break;
 300                         }
 301                         if (IPPROTO_IP == answer->protocol)
 302                                 break;
 303                 }
 304                 err = -EPROTONOSUPPORT;
 305         }
 306
 307         if (unlikely(err)) {
 308                 if (try_loading_module < 2) {
 309                         rcu_read_unlock();
 310                         /*
 311                          * Be more specific, e.g. net-pf-2-proto-132-type-1
 312                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 313                          */
 314                         if (++try_loading_module == 1)
 315                                 request_module("net-pf-%d-proto-%d-type-%d",
 316                                                PF_INET, protocol, sock->type);
 317                         /*
 318                          * Fall back to generic, e.g. net-pf-2-proto-132
 319                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 320                          */
 321                         else
 322                                 request_module("net-pf-%d-proto-%d",
 323                                                PF_INET, protocol);
 324                         goto lookup_protocol;
 325                 } else
 326                         goto out_rcu_unlock;
 327         }
 328
 329         err = -EPERM;
 330         if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
 331                 goto out_rcu_unlock;
 332
 333         err = -EAFNOSUPPORT;
 334         if (!inet_netns_ok(net, protocol))
 335                 goto out_rcu_unlock;
 336
 337         sock->ops = answer->ops;
 338         answer_prot = answer->prot;
 339         answer_no_check = answer->no_check;
 340         answer_flags = answer->flags;
 341         rcu_read_unlock();
 342
 343         WARN_ON(answer_prot->slab == NULL);
 344
 345         err = -ENOBUFS;
 346         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
 347         if (sk == NULL)
 348                 goto out;
 349
 350         err = 0;
 351         sk->sk_no_check = answer_no_check;
 352         if (INET_PROTOSW_REUSE & answer_flags)
 353                 sk->sk_reuse = SK_CAN_REUSE;
 354
 355         inet = inet_sk(sk);
 356         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 357
 358         inet->nodefrag = 0;
 359
 360         if (SOCK_RAW == sock->type) {
 361                 inet->inet_num = protocol;
 362                 if (IPPROTO_RAW == protocol)
 363                         inet->hdrincl = 1;
 364         }
 365
 366         if (ipv4_config.no_pmtu_disc)
 367                 inet->pmtudisc = IP_PMTUDISC_DONT;
 368         else
 369                 inet->pmtudisc = IP_PMTUDISC_WANT;
 370
 371         inet->inet_id = 0;
 372
 373         sock_init_data(sock, sk);
 374
 375         sk->sk_destruct    = inet_sock_destruct;
 376         sk->sk_protocol    = protocol;
 377         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 378
 379         inet->uc_ttl    = -1;
 380         inet->mc_loop   = 1;
 381         inet->mc_ttl    = 1;
 382         inet->mc_all    = 1;
 383         inet->mc_index  = 0;
 384         inet->mc_list   = NULL;
 385         inet->rcv_tos   = 0;
 386
 387         sk_refcnt_debug_inc(sk);
 388
 389         if (inet->inet_num) {
 390                 /* It assumes that any protocol which allows
 391                  * the user to assign a number at socket
 392                  * creation time automatically
 393                  * shares.
 394                  */
 395                 inet->inet_sport = htons(inet->inet_num);
 396                 /* Add to protocol hash chains. */
 397                 sk->sk_prot->hash(sk);
 398         }
 399
 400         if (sk->sk_prot->init) {
 401                 err = sk->sk_prot->init(sk);
 402                 if (err)
 403                         sk_common_release(sk);
 404         }
 405 out:
 406         return err;
 407 out_rcu_unlock:
 408         rcu_read_unlock();
 409         goto out;
 410 }
 411
 412
 413 /*
 414  *      The peer socket should always be NULL (or else). When we call this
 415  *      function we are destroying the object and from then on nobody
 416  *      should refer to it.
 417  */
 418 int inet_release(struct socket *sock)
 419 {
 420         struct sock *sk = sock->sk;
 421
 422         if (sk) {
 423                 long timeout;
 424
 425                 sock_rps_reset_flow(sk);
 426
 427                 /* Applications forget to leave groups before exiting */
 428                 ip_mc_drop_socket(sk);
 429
 430                 /* If linger is set, we don't return until the close
 431                  * is complete.  Otherwise we return immediately. The
 432                  * actually closing is done the same either way.
 433                  *
 434                  * If the close is due to the process exiting, we never
 435                  * linger..
 436                  */
 437                 timeout = 0;
 438                 if (sock_flag(sk, SOCK_LINGER) &&
 439                     !(current->flags & PF_EXITING))
 440                         timeout = sk->sk_lingertime;
 441                 sock->sk = NULL;
 442                 sk->sk_prot->close(sk, timeout);
 443         }
 444         return 0;
 445 }
 446 EXPORT_SYMBOL(inet_release);
 447
 448 /* It is off by default, see below. */
 449 int sysctl_ip_nonlocal_bind __read_mostly;
 450 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
 451
 452 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 453 {
 454         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 455         struct sock *sk = sock->sk;
 456         struct inet_sock *inet = inet_sk(sk);
 457         unsigned short snum;
 458         int chk_addr_ret;
 459         int err;
 460
 461         /* If the socket has its own bind function then use it. (RAW) */
 462         if (sk->sk_prot->bind) {
 463                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
 464                 goto out;
 465         }
 466         err = -EINVAL;
 467         if (addr_len < sizeof(struct sockaddr_in))
 468                 goto out;
 469
 470         if (addr->sin_family != AF_INET) {
 471                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
 472                  * only if s_addr is INADDR_ANY.
 473                  */
 474                 err = -EAFNOSUPPORT;
 475                 if (addr->sin_family != AF_UNSPEC ||
 476                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
 477                         goto out;
 478         }
 479
 480         chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
 481
 482         /* Not specified by any standard per-se, however it breaks too
 483          * many applications when removed.  It is unfortunate since
 484          * allowing applications to make a non-local bind solves
 485          * several problems with systems using dynamic addressing.
 486          * (ie. your servers still start up even if your ISDN link
 487          *  is temporarily down)
 488          */
 489         err = -EADDRNOTAVAIL;
 490         if (!sysctl_ip_nonlocal_bind &&
 491             !(inet->freebind || inet->transparent) &&
 492             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
 493             chk_addr_ret != RTN_LOCAL &&
 494             chk_addr_ret != RTN_MULTICAST &&
 495             chk_addr_ret != RTN_BROADCAST)
 496                 goto out;
 497
 498         snum = ntohs(addr->sin_port);
 499         err = -EACCES;
 500         if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
 501                 goto out;
 502
 503         /*      We keep a pair of addresses. rcv_saddr is the one
 504          *      used by hash lookups, and saddr is used for transmit.
 505          *
 506          *      In the BSD API these are the same except where it
 507          *      would be illegal to use them (multicast/broadcast) in
 508          *      which case the sending device address is used.
 509          */
 510         lock_sock(sk);
 511
 512         /* Check these errors (active socket, double bind). */
 513         err = -EINVAL;
 514         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
 515                 goto out_release_sock;
 516
 517         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
 518         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 519                 inet->inet_saddr = 0;  /* Use device */
 520
 521         /* Make sure we are allowed to bind here. */
 522         if (sk->sk_prot->get_port(sk, snum)) {
 523                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
 524                 err = -EADDRINUSE;
 525                 goto out_release_sock;
 526         }
 527
 528         if (inet->inet_rcv_saddr)
 529                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 530         if (snum)
 531                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 532         inet->inet_sport = htons(inet->inet_num);
 533         inet->inet_daddr = 0;
 534         inet->inet_dport = 0;
 535         sk_dst_reset(sk);
 536         err = 0;
 537 out_release_sock:
 538         release_sock(sk);
 539 out:
 540         return err;
 541 }
 542 EXPORT_SYMBOL(inet_bind);
 543
 544 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 545                        int addr_len, int flags)
 546 {
 547         struct sock *sk = sock->sk;
 548
 549         if (addr_len < sizeof(uaddr->sa_family))
 550                 return -EINVAL;
 551         if (uaddr->sa_family == AF_UNSPEC)
 552                 return sk->sk_prot->disconnect(sk, flags);
 553
 554         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
 555                 return -EAGAIN;
 556         return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
 557 }
 558 EXPORT_SYMBOL(inet_dgram_connect);
 559
 560 static long inet_wait_for_connect(struct sock *sk, long timeo)
 561 {
 562         DEFINE_WAIT(wait);
 563
 564         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 565
 566         /* Basic assumption: if someone sets sk->sk_err, he _must_
 567          * change state of the socket from TCP_SYN_*.
 568          * Connect() does not allow to get error notifications
 569          * without closing the socket.
 570          */
 571         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 572                 release_sock(sk);
 573                 timeo = schedule_timeout(timeo);
 574                 lock_sock(sk);
 575                 if (signal_pending(current) || !timeo)
 576                         break;
 577                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 578         }
 579         finish_wait(sk_sleep(sk), &wait);
 580         return timeo;
 581 }
 582
 583 /*
 584  *      Connect to a remote host. There is regrettably still a little
 585  *      TCP 'magic' in here.
 586  */
 587 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 588                         int addr_len, int flags)
 589 {
 590         struct sock *sk = sock->sk;
 591         int err;
 592         long timeo;
 593
 594         if (addr_len < sizeof(uaddr->sa_family))
 595                 return -EINVAL;
 596
 597         lock_sock(sk);
 598
 599         if (uaddr->sa_family == AF_UNSPEC) {
 600                 err = sk->sk_prot->disconnect(sk, flags);
 601                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 602                 goto out;
 603         }
 604
 605         switch (sock->state) {
 606         default:
 607                 err = -EINVAL;
 608                 goto out;
 609         case SS_CONNECTED:
 610                 err = -EISCONN;
 611                 goto out;
 612         case SS_CONNECTING:
 613                 err = -EALREADY;
 614                 /* Fall out of switch with err, set for this state */
 615                 break;
 616         case SS_UNCONNECTED:
 617                 err = -EISCONN;
 618                 if (sk->sk_state != TCP_CLOSE)
 619                         goto out;
 620
 621                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
 622                 if (err < 0)
 623                         goto out;
 624
 625                 sock->state = SS_CONNECTING;
 626
 627                 /* Just entered SS_CONNECTING state; the only
 628                  * difference is that return value in non-blocking
 629                  * case is EINPROGRESS, rather than EALREADY.
 630                  */
 631                 err = -EINPROGRESS;
 632                 break;
 633         }
 634
 635         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 636
 637         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 638                 /* Error code is set above */
 639                 if (!timeo || !inet_wait_for_connect(sk, timeo))
 640                         goto out;
 641
 642                 err = sock_intr_errno(timeo);
 643                 if (signal_pending(current))
 644                         goto out;
 645         }
 646
 647         /* Connection was closed by RST, timeout, ICMP error
 648          * or another process disconnected us.
 649          */
 650         if (sk->sk_state == TCP_CLOSE)
 651                 goto sock_error;
 652
 653         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 654          * and error was received after socket entered established state.
 655          * Hence, it is handled normally after connect() return successfully.
 656          */
 657
 658         sock->state = SS_CONNECTED;
 659         err = 0;
 660 out:
 661         release_sock(sk);
 662         return err;
 663
 664 sock_error:
 665         err = sock_error(sk) ? : -ECONNABORTED;
 666         sock->state = SS_UNCONNECTED;
 667         if (sk->sk_prot->disconnect(sk, flags))
 668                 sock->state = SS_DISCONNECTING;
 669         goto out;
 670 }
 671 EXPORT_SYMBOL(inet_stream_connect);
 672
 673 /*
 674  *      Accept a pending connection. The TCP layer now gives BSD semantics.
 675  */
 676
 677 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
 678 {
 679         struct sock *sk1 = sock->sk;
 680         int err = -EINVAL;
 681         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
 682
 683         if (!sk2)
 684                 goto do_err;
 685
 686         lock_sock(sk2);
 687
 688         sock_rps_record_flow(sk2);
 689         WARN_ON(!((1 << sk2->sk_state) &
 690                   (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 691
 692         sock_graft(sk2, newsock);
 693
 694         newsock->state = SS_CONNECTED;
 695         err = 0;
 696         release_sock(sk2);
 697 do_err:
 698         return err;
 699 }
 700 EXPORT_SYMBOL(inet_accept);
 701
 702
 703 /*
 704  *      This does both peername and sockname.
 705  */
 706 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 707                         int *uaddr_len, int peer)
 708 {
 709         struct sock *sk         = sock->sk;
 710         struct inet_sock *inet  = inet_sk(sk);
 711         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 712
 713         sin->sin_family = AF_INET;
 714         if (peer) {
 715                 if (!inet->inet_dport ||
 716                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 717                      peer == 1))
 718                         return -ENOTCONN;
 719                 sin->sin_port = inet->inet_dport;
 720                 sin->sin_addr.s_addr = inet->inet_daddr;
 721         } else {
 722                 __be32 addr = inet->inet_rcv_saddr;
 723                 if (!addr)
 724                         addr = inet->inet_saddr;
 725                 sin->sin_port = inet->inet_sport;
 726                 sin->sin_addr.s_addr = addr;
 727         }
 728         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 729         *uaddr_len = sizeof(*sin);
 730         return 0;
 731 }
 732 EXPORT_SYMBOL(inet_getname);
 733
 734 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 735                  size_t size)
 736 {
 737         struct sock *sk = sock->sk;
 738
 739         sock_rps_record_flow(sk);
 740
 741         /* We may need to bind the socket. */
 742         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 743             inet_autobind(sk))
 744                 return -EAGAIN;
 745
 746         return sk->sk_prot->sendmsg(iocb, sk, msg, size);
 747 }
 748 EXPORT_SYMBOL(inet_sendmsg);
 749
 750 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 751                       size_t size, int flags)
 752 {
 753         struct sock *sk = sock->sk;
 754
 755         sock_rps_record_flow(sk);
 756
 757         /* We may need to bind the socket. */
 758         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 759             inet_autobind(sk))
 760                 return -EAGAIN;
 761
 762         if (sk->sk_prot->sendpage)
 763                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
 764         return sock_no_sendpage(sock, page, offset, size, flags);
 765 }
 766 EXPORT_SYMBOL(inet_sendpage);
 767
 768 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 769                  size_t size, int flags)
 770 {
 771         struct sock *sk = sock->sk;
 772         int addr_len = 0;
 773         int err;
 774
 775         sock_rps_record_flow(sk);
 776
 777         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
 778                                    flags & ~MSG_DONTWAIT, &addr_len);
 779         if (err >= 0)
 780                 msg->msg_namelen = addr_len;
 781         return err;
 782 }
 783 EXPORT_SYMBOL(inet_recvmsg);
 784
 785 int inet_shutdown(struct socket *sock, int how)
 786 {
 787         struct sock *sk = sock->sk;
 788         int err = 0;
 789
 790         /* This should really check to make sure
 791          * the socket is a TCP socket. (WHY AC...)
 792          */
 793         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 794                        1->2 bit 2 snds.
 795                        2->3 */
 796         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 797                 return -EINVAL;
 798
 799         lock_sock(sk);
 800         if (sock->state == SS_CONNECTING) {
 801                 if ((1 << sk->sk_state) &
 802                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 803                         sock->state = SS_DISCONNECTING;
 804                 else
 805                         sock->state = SS_CONNECTED;
 806         }
 807
 808         switch (sk->sk_state) {
 809         case TCP_CLOSE:
 810                 err = -ENOTCONN;
 811                 /* Hack to wake up other listeners, who can poll for
 812                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
 813         default:
 814                 sk->sk_shutdown |= how;
 815                 if (sk->sk_prot->shutdown)
 816                         sk->sk_prot->shutdown(sk, how);
 817                 break;
 818
 819         /* Remaining two branches are temporary solution for missing
 820          * close() in multithreaded environment. It is _not_ a good idea,
 821          * but we have no choice until close() is repaired at VFS level.
 822          */
 823         case TCP_LISTEN:
 824                 if (!(how & RCV_SHUTDOWN))
 825                         break;
 826                 /* Fall through */
 827         case TCP_SYN_SENT:
 828                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 829                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 830                 break;
 831         }
 832
 833         /* Wake up anyone sleeping in poll. */
 834         sk->sk_state_change(sk);
 835         release_sock(sk);
 836         return err;
 837 }
 838 EXPORT_SYMBOL(inet_shutdown);
 839
 840 /*
 841  *      ioctl() calls you can issue on an INET socket. Most of these are
 842  *      device configuration and stuff and very rarely used. Some ioctls
 843  *      pass on to the socket itself.
 844  *
 845  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 846  *      loads the devconfigure module does its configuring and unloads it.
 847  *      There's a good 20K of config code hanging around the kernel.
 848  */
 849
 850 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 851 {
 852         struct sock *sk = sock->sk;
 853         int err = 0;
 854         struct net *net = sock_net(sk);
 855
 856         switch (cmd) {
 857         case SIOCGSTAMP:
 858                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
 859                 break;
 860         case SIOCGSTAMPNS:
 861                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
 862                 break;
 863         case SIOCADDRT:
 864         case SIOCDELRT:
 865         case SIOCRTMSG:
 866                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
 867                 break;
 868         case SIOCDARP:
 869         case SIOCGARP:
 870         case SIOCSARP:
 871                 err = arp_ioctl(net, cmd, (void __user *)arg);
 872                 break;
 873         case SIOCGIFADDR:
 874         case SIOCSIFADDR:
 875         case SIOCGIFBRDADDR:
 876         case SIOCSIFBRDADDR:
 877         case SIOCGIFNETMASK:
 878         case SIOCSIFNETMASK:
 879         case SIOCGIFDSTADDR:
 880         case SIOCSIFDSTADDR:
 881         case SIOCSIFPFLAGS:
 882         case SIOCGIFPFLAGS:
 883         case SIOCSIFFLAGS:
 884                 err = devinet_ioctl(net, cmd, (void __user *)arg);
 885                 break;
 886         default:
 887                 if (sk->sk_prot->ioctl)
 888                         err = sk->sk_prot->ioctl(sk, cmd, arg);
 889                 else
 890                         err = -ENOIOCTLCMD;
 891                 break;
 892         }
 893         return err;
 894 }
 895 EXPORT_SYMBOL(inet_ioctl);
 896
 897 #ifdef CONFIG_COMPAT
 898 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 899 {
 900         struct sock *sk = sock->sk;
 901         int err = -ENOIOCTLCMD;
 902
 903         if (sk->sk_prot->compat_ioctl)
 904                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
 905
 906         return err;
 907 }
 908 #endif
 909
 910 const struct proto_ops inet_stream_ops = {
 911         .family            = PF_INET,
 912         .owner             = THIS_MODULE,
 913         .release           = inet_release,
 914         .bind              = inet_bind,
 915         .connect           = inet_stream_connect,
 916         .socketpair        = sock_no_socketpair,
 917         .accept            = inet_accept,
 918         .getname           = inet_getname,
 919         .poll              = tcp_poll,
 920         .ioctl             = inet_ioctl,
 921         .listen            = inet_listen,
 922         .shutdown          = inet_shutdown,
 923         .setsockopt        = sock_common_setsockopt,
 924         .getsockopt        = sock_common_getsockopt,
 925         .sendmsg           = inet_sendmsg,
 926         .recvmsg           = inet_recvmsg,
 927         .mmap              = sock_no_mmap,
 928         .sendpage          = inet_sendpage,
 929         .splice_read       = tcp_splice_read,
 930 #ifdef CONFIG_COMPAT
 931         .compat_setsockopt = compat_sock_common_setsockopt,
 932         .compat_getsockopt = compat_sock_common_getsockopt,
 933         .compat_ioctl      = inet_compat_ioctl,
 934 #endif
 935 };
 936 EXPORT_SYMBOL(inet_stream_ops);
 937
 938 const struct proto_ops inet_dgram_ops = {
 939         .family            = PF_INET,
 940         .owner             = THIS_MODULE,
 941         .release           = inet_release,
 942         .bind              = inet_bind,
 943         .connect           = inet_dgram_connect,
 944         .socketpair        = sock_no_socketpair,
 945         .accept            = sock_no_accept,
 946         .getname           = inet_getname,
 947         .poll              = udp_poll,
 948         .ioctl             = inet_ioctl,
 949         .listen            = sock_no_listen,
 950         .shutdown          = inet_shutdown,
 951         .setsockopt        = sock_common_setsockopt,
 952         .getsockopt        = sock_common_getsockopt,
 953         .sendmsg           = inet_sendmsg,
 954         .recvmsg           = inet_recvmsg,
 955         .mmap              = sock_no_mmap,
 956         .sendpage          = inet_sendpage,
 957 #ifdef CONFIG_COMPAT
 958         .compat_setsockopt = compat_sock_common_setsockopt,
 959         .compat_getsockopt = compat_sock_common_getsockopt,
 960         .compat_ioctl      = inet_compat_ioctl,
 961 #endif
 962 };
 963 EXPORT_SYMBOL(inet_dgram_ops);
 964
 965 /*
 966  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
 967  * udp_poll
 968  */
 969 static const struct proto_ops inet_sockraw_ops = {
 970         .family            = PF_INET,
 971         .owner             = THIS_MODULE,
 972         .release           = inet_release,
 973         .bind              = inet_bind,
 974         .connect           = inet_dgram_connect,
 975         .socketpair        = sock_no_socketpair,
 976         .accept            = sock_no_accept,
 977         .getname           = inet_getname,
 978         .poll              = datagram_poll,
 979         .ioctl             = inet_ioctl,
 980         .listen            = sock_no_listen,
 981         .shutdown          = inet_shutdown,
 982         .setsockopt        = sock_common_setsockopt,
 983         .getsockopt        = sock_common_getsockopt,
 984         .sendmsg           = inet_sendmsg,
 985         .recvmsg           = inet_recvmsg,
 986         .mmap              = sock_no_mmap,
 987         .sendpage          = inet_sendpage,
 988 #ifdef CONFIG_COMPAT
 989         .compat_setsockopt = compat_sock_common_setsockopt,
 990         .compat_getsockopt = compat_sock_common_getsockopt,
 991         .compat_ioctl      = inet_compat_ioctl,
 992 #endif
 993 };
 994
 995 static const struct net_proto_family inet_family_ops = {
 996         .family = PF_INET,
 997         .create = inet_create,
 998         .owner  = THIS_MODULE,
 999 };
1000
1001 /* Upon startup we insert all the elements in inetsw_array[] into
1002  * the linked list inetsw.
1003  */
1004 static struct inet_protosw inetsw_array[] =
1005 {
1006         {
1007                 .type =       SOCK_STREAM,
1008                 .protocol =   IPPROTO_TCP,
1009                 .prot =       &tcp_prot,
1010                 .ops =        &inet_stream_ops,
1011                 .no_check =   0,
1012                 .flags =      INET_PROTOSW_PERMANENT |
1013                               INET_PROTOSW_ICSK,
1014         },
1015
1016         {
1017                 .type =       SOCK_DGRAM,
1018                 .protocol =   IPPROTO_UDP,
1019                 .prot =       &udp_prot,
1020                 .ops =        &inet_dgram_ops,
1021                 .no_check =   UDP_CSUM_DEFAULT,
1022                 .flags =      INET_PROTOSW_PERMANENT,
1023        },
1024
1025        {
1026                 .type =       SOCK_DGRAM,
1027                 .protocol =   IPPROTO_ICMP,
1028                 .prot =       &ping_prot,
1029                 .ops =        &inet_dgram_ops,
1030                 .no_check =   UDP_CSUM_DEFAULT,
1031                 .flags =      INET_PROTOSW_REUSE,
1032        },
1033
1034        {
1035                .type =       SOCK_RAW,
1036                .protocol =   IPPROTO_IP,        /* wild card */
1037                .prot =       &raw_prot,
1038                .ops =        &inet_sockraw_ops,
1039                .no_check =   UDP_CSUM_DEFAULT,
1040                .flags =      INET_PROTOSW_REUSE,
1041        }
1042 };
1043
1044 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1045
1046 void inet_register_protosw(struct inet_protosw *p)
1047 {
1048         struct list_head *lh;
1049         struct inet_protosw *answer;
1050         int protocol = p->protocol;
1051         struct list_head *last_perm;
1052
1053         spin_lock_bh(&inetsw_lock);
1054
1055         if (p->type >= SOCK_MAX)
1056                 goto out_illegal;
1057
1058         /* If we are trying to override a permanent protocol, bail. */
1059         answer = NULL;
1060         last_perm = &inetsw[p->type];
1061         list_for_each(lh, &inetsw[p->type]) {
1062                 answer = list_entry(lh, struct inet_protosw, list);
1063
1064                 /* Check only the non-wild match. */
1065                 if (INET_PROTOSW_PERMANENT & answer->flags) {
1066                         if (protocol == answer->protocol)
1067                                 break;
1068                         last_perm = lh;
1069                 }
1070
1071                 answer = NULL;
1072         }
1073         if (answer)
1074                 goto out_permanent;
1075
1076         /* Add the new entry after the last permanent entry if any, so that
1077          * the new entry does not override a permanent entry when matched with
1078          * a wild-card protocol. But it is allowed to override any existing
1079          * non-permanent entry.  This means that when we remove this entry, the
1080          * system automatically returns to the old behavior.
1081          */
1082         list_add_rcu(&p->list, last_perm);
1083 out:
1084         spin_unlock_bh(&inetsw_lock);
1085
1086         return;
1087
1088 out_permanent:
1089         pr_err("Attempt to override permanent protocol %d\n", protocol);
1090         goto out;
1091
1092 out_illegal:
1093         pr_err("Ignoring attempt to register invalid socket type %d\n",
1094                p->type);
1095         goto out;
1096 }
1097 EXPORT_SYMBOL(inet_register_protosw);
1098
1099 void inet_unregister_protosw(struct inet_protosw *p)
1100 {
1101         if (INET_PROTOSW_PERMANENT & p->flags) {
1102                 pr_err("Attempt to unregister permanent protocol %d\n",
1103                        p->protocol);
1104         } else {
1105                 spin_lock_bh(&inetsw_lock);
1106                 list_del_rcu(&p->list);
1107                 spin_unlock_bh(&inetsw_lock);
1108
1109                 synchronize_net();
1110         }
1111 }
1112 EXPORT_SYMBOL(inet_unregister_protosw);
1113
1114 /*
1115  *      Shall we try to damage output packets if routing dev changes?
1116  */
1117
1118 int sysctl_ip_dynaddr __read_mostly;
1119
1120 static int inet_sk_reselect_saddr(struct sock *sk)
1121 {
1122         struct inet_sock *inet = inet_sk(sk);
1123         __be32 old_saddr = inet->inet_saddr;
1124         __be32 daddr = inet->inet_daddr;
1125         struct flowi4 *fl4;
1126         struct rtable *rt;
1127         __be32 new_saddr;
1128         struct ip_options_rcu *inet_opt;
1129
1130         inet_opt = rcu_dereference_protected(inet->inet_opt,
1131                                              sock_owned_by_user(sk));
1132         if (inet_opt && inet_opt->opt.srr)
1133                 daddr = inet_opt->opt.faddr;
1134
1135         /* Query new route. */
1136         fl4 = &inet->cork.fl.u.ip4;
1137         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1138                               sk->sk_bound_dev_if, sk->sk_protocol,
1139                               inet->inet_sport, inet->inet_dport, sk, false);
1140         if (IS_ERR(rt))
1141                 return PTR_ERR(rt);
1142
1143         sk_setup_caps(sk, &rt->dst);
1144
1145         new_saddr = fl4->saddr;
1146
1147         if (new_saddr == old_saddr)
1148                 return 0;
1149
1150         if (sysctl_ip_dynaddr > 1) {
1151                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1152                         __func__, &old_saddr, &new_saddr);
1153         }
1154
1155         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1156
1157         /*
1158          * XXX The only one ugly spot where we need to
1159          * XXX really change the sockets identity after
1160          * XXX it has entered the hashes. -DaveM
1161          *
1162          * Besides that, it does not check for connection
1163          * uniqueness. Wait for troubles.
1164          */
1165         __sk_prot_rehash(sk);
1166         return 0;
1167 }
1168
1169 int inet_sk_rebuild_header(struct sock *sk)
1170 {
1171         struct inet_sock *inet = inet_sk(sk);
1172         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1173         __be32 daddr;
1174         struct ip_options_rcu *inet_opt;
1175         struct flowi4 *fl4;
1176         int err;
1177
1178         /* Route is OK, nothing to do. */
1179         if (rt)
1180                 return 0;
1181
1182         /* Reroute. */
1183         rcu_read_lock();
1184         inet_opt = rcu_dereference(inet->inet_opt);
1185         daddr = inet->inet_daddr;
1186         if (inet_opt && inet_opt->opt.srr)
1187                 daddr = inet_opt->opt.faddr;
1188         rcu_read_unlock();
1189         fl4 = &inet->cork.fl.u.ip4;
1190         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1191                                    inet->inet_dport, inet->inet_sport,
1192                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1193                                    sk->sk_bound_dev_if);
1194         if (!IS_ERR(rt)) {
1195                 err = 0;
1196                 sk_setup_caps(sk, &rt->dst);
1197         } else {
1198                 err = PTR_ERR(rt);
1199
1200                 /* Routing failed... */
1201                 sk->sk_route_caps = 0;
1202                 /*
1203                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1204                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1205                  */
1206                 if (!sysctl_ip_dynaddr ||
1207                     sk->sk_state != TCP_SYN_SENT ||
1208                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1209                     (err = inet_sk_reselect_saddr(sk)) != 0)
1210                         sk->sk_err_soft = -err;
1211         }
1212
1213         return err;
1214 }
1215 EXPORT_SYMBOL(inet_sk_rebuild_header);
1216
1217 static int inet_gso_send_check(struct sk_buff *skb)
1218 {
1219         const struct iphdr *iph;
1220         const struct net_protocol *ops;
1221         int proto;
1222         int ihl;
1223         int err = -EINVAL;
1224
1225         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1226                 goto out;
1227
1228         iph = ip_hdr(skb);
1229         ihl = iph->ihl * 4;
1230         if (ihl < sizeof(*iph))
1231                 goto out;
1232
1233         if (unlikely(!pskb_may_pull(skb, ihl)))
1234                 goto out;
1235
1236         __skb_pull(skb, ihl);
1237         skb_reset_transport_header(skb);
1238         iph = ip_hdr(skb);
1239         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1240         err = -EPROTONOSUPPORT;
1241
1242         rcu_read_lock();
1243         ops = rcu_dereference(inet_protos[proto]);
1244         if (likely(ops && ops->gso_send_check))
1245                 err = ops->gso_send_check(skb);
1246         rcu_read_unlock();
1247
1248 out:
1249         return err;
1250 }
1251
1252 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1253         netdev_features_t features)
1254 {
1255         struct sk_buff *segs = ERR_PTR(-EINVAL);
1256         struct iphdr *iph;
1257         const struct net_protocol *ops;
1258         int proto;
1259         int ihl;
1260         int id;
1261         unsigned int offset = 0;
1262
1263         if (!(features & NETIF_F_V4_CSUM))
1264                 features &= ~NETIF_F_SG;
1265
1266         if (unlikely(skb_shinfo(skb)->gso_type &
1267                      ~(SKB_GSO_TCPV4 |
1268                        SKB_GSO_UDP |
1269                        SKB_GSO_DODGY |
1270                        SKB_GSO_TCP_ECN |
1271                        0)))
1272                 goto out;
1273
1274         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1275                 goto out;
1276
1277         iph = ip_hdr(skb);
1278         ihl = iph->ihl * 4;
1279         if (ihl < sizeof(*iph))
1280                 goto out;
1281
1282         if (unlikely(!pskb_may_pull(skb, ihl)))
1283                 goto out;
1284
1285         __skb_pull(skb, ihl);
1286         skb_reset_transport_header(skb);
1287         iph = ip_hdr(skb);
1288         id = ntohs(iph->id);
1289         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1290         segs = ERR_PTR(-EPROTONOSUPPORT);
1291
1292         rcu_read_lock();
1293         ops = rcu_dereference(inet_protos[proto]);
1294         if (likely(ops && ops->gso_segment))
1295                 segs = ops->gso_segment(skb, features);
1296         rcu_read_unlock();
1297
1298         if (!segs || IS_ERR(segs))
1299                 goto out;
1300
1301         skb = segs;
1302         do {
1303                 iph = ip_hdr(skb);
1304                 if (proto == IPPROTO_UDP) {
1305                         iph->id = htons(id);
1306                         iph->frag_off = htons(offset >> 3);
1307                         if (skb->next != NULL)
1308                                 iph->frag_off |= htons(IP_MF);
1309                         offset += (skb->len - skb->mac_len - iph->ihl * 4);
1310                 } else
1311                         iph->id = htons(id++);
1312                 iph->tot_len = htons(skb->len - skb->mac_len);
1313                 iph->check = 0;
1314                 iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1315         } while ((skb = skb->next));
1316
1317 out:
1318         return segs;
1319 }
1320
1321 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1322                                          struct sk_buff *skb)
1323 {
1324         const struct net_protocol *ops;
1325         struct sk_buff **pp = NULL;
1326         struct sk_buff *p;
1327         const struct iphdr *iph;
1328         unsigned int hlen;
1329         unsigned int off;
1330         unsigned int id;
1331         int flush = 1;
1332         int proto;
1333
1334         off = skb_gro_offset(skb);
1335         hlen = off + sizeof(*iph);
1336         iph = skb_gro_header_fast(skb, off);
1337         if (skb_gro_header_hard(skb, hlen)) {
1338                 iph = skb_gro_header_slow(skb, hlen, off);
1339                 if (unlikely(!iph))
1340                         goto out;
1341         }
1342
1343         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1344
1345         rcu_read_lock();
1346         ops = rcu_dereference(inet_protos[proto]);
1347         if (!ops || !ops->gro_receive)
1348                 goto out_unlock;
1349
1350         if (*(u8 *)iph != 0x45)
1351                 goto out_unlock;
1352
1353         if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1354                 goto out_unlock;
1355
1356         id = ntohl(*(__be32 *)&iph->id);
1357         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1358         id >>= 16;
1359
1360         for (p = *head; p; p = p->next) {
1361                 struct iphdr *iph2;
1362
1363                 if (!NAPI_GRO_CB(p)->same_flow)
1364                         continue;
1365
1366                 iph2 = ip_hdr(p);
1367
1368                 if ((iph->protocol ^ iph2->protocol) |
1369                     (iph->tos ^ iph2->tos) |
1370                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1371                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1372                         NAPI_GRO_CB(p)->same_flow = 0;
1373                         continue;
1374                 }
1375
1376                 /* All fields must match except length and checksum. */
1377                 NAPI_GRO_CB(p)->flush |=
1378                         (iph->ttl ^ iph2->ttl) |
1379                         ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1380
1381                 NAPI_GRO_CB(p)->flush |= flush;
1382         }
1383
1384         NAPI_GRO_CB(skb)->flush |= flush;
1385         skb_gro_pull(skb, sizeof(*iph));
1386         skb_set_transport_header(skb, skb_gro_offset(skb));
1387
1388         pp = ops->gro_receive(head, skb);
1389
1390 out_unlock:
1391         rcu_read_unlock();
1392
1393 out:
1394         NAPI_GRO_CB(skb)->flush |= flush;
1395
1396         return pp;
1397 }
1398
1399 static int inet_gro_complete(struct sk_buff *skb)
1400 {
1401         const struct net_protocol *ops;
1402         struct iphdr *iph = ip_hdr(skb);
1403         int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1404         int err = -ENOSYS;
1405         __be16 newlen = htons(skb->len - skb_network_offset(skb));
1406
1407         csum_replace2(&iph->check, iph->tot_len, newlen);
1408         iph->tot_len = newlen;
1409
1410         rcu_read_lock();
1411         ops = rcu_dereference(inet_protos[proto]);
1412         if (WARN_ON(!ops || !ops->gro_complete))
1413                 goto out_unlock;
1414
1415         err = ops->gro_complete(skb);
1416
1417 out_unlock:
1418         rcu_read_unlock();
1419
1420         return err;
1421 }
1422
1423 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1424                          unsigned short type, unsigned char protocol,
1425                          struct net *net)
1426 {
1427         struct socket *sock;
1428         int rc = sock_create_kern(family, type, protocol, &sock);
1429
1430         if (rc == 0) {
1431                 *sk = sock->sk;
1432                 (*sk)->sk_allocation = GFP_ATOMIC;
1433                 /*
1434                  * Unhash it so that IP input processing does not even see it,
1435                  * we do not wish this socket to see incoming packets.
1436                  */
1437                 (*sk)->sk_prot->unhash(*sk);
1438
1439                 sk_change_net(*sk, net);
1440         }
1441         return rc;
1442 }
1443 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1444
1445 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1446 {
1447         unsigned long res = 0;
1448         int i, j;
1449
1450         for_each_possible_cpu(i) {
1451                 for (j = 0; j < SNMP_ARRAY_SZ; j++)
1452                         res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1453         }
1454         return res;
1455 }
1456 EXPORT_SYMBOL_GPL(snmp_fold_field);
1457
1458 #if BITS_PER_LONG==32
1459
1460 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1461 {
1462         u64 res = 0;
1463         int cpu;
1464
1465         for_each_possible_cpu(cpu) {
1466                 void *bhptr;
1467                 struct u64_stats_sync *syncp;
1468                 u64 v;
1469                 unsigned int start;
1470
1471                 bhptr = per_cpu_ptr(mib[0], cpu);
1472                 syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1473                 do {
1474                         start = u64_stats_fetch_begin_bh(syncp);
1475                         v = *(((u64 *) bhptr) + offt);
1476                 } while (u64_stats_fetch_retry_bh(syncp, start));
1477
1478                 res += v;
1479         }
1480         return res;
1481 }
1482 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1483 #endif
1484
1485 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1486 {
1487         BUG_ON(ptr == NULL);
1488         ptr[0] = __alloc_percpu(mibsize, align);
1489         if (!ptr[0])
1490                 return -ENOMEM;
1491 #if SNMP_ARRAY_SZ == 2
1492         ptr[1] = __alloc_percpu(mibsize, align);
1493         if (!ptr[1]) {
1494                 free_percpu(ptr[0]);
1495                 ptr[0] = NULL;
1496                 return -ENOMEM;
1497         }
1498 #endif
1499         return 0;
1500 }
1501 EXPORT_SYMBOL_GPL(snmp_mib_init);
1502
1503 void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
1504 {
1505         int i;
1506
1507         BUG_ON(ptr == NULL);
1508         for (i = 0; i < SNMP_ARRAY_SZ; i++) {
1509                 free_percpu(ptr[i]);
1510                 ptr[i] = NULL;
1511         }
1512 }
1513 EXPORT_SYMBOL_GPL(snmp_mib_free);
1514
1515 #ifdef CONFIG_IP_MULTICAST
1516 static const struct net_protocol igmp_protocol = {
1517         .handler =      igmp_rcv,
1518         .netns_ok =     1,
1519 };
1520 #endif
1521
1522 static const struct net_protocol tcp_protocol = {
1523         .handler =      tcp_v4_rcv,
1524         .err_handler =  tcp_v4_err,
1525         .gso_send_check = tcp_v4_gso_send_check,
1526         .gso_segment =  tcp_tso_segment,
1527         .gro_receive =  tcp4_gro_receive,
1528         .gro_complete = tcp4_gro_complete,
1529         .no_policy =    1,
1530         .netns_ok =     1,
1531 };
1532
1533 static const struct net_protocol udp_protocol = {
1534         .handler =      udp_rcv,
1535         .err_handler =  udp_err,
1536         .gso_send_check = udp4_ufo_send_check,
1537         .gso_segment = udp4_ufo_fragment,
1538         .no_policy =    1,
1539         .netns_ok =     1,
1540 };
1541
1542 static const struct net_protocol icmp_protocol = {
1543         .handler =      icmp_rcv,
1544         .err_handler =  ping_err,
1545         .no_policy =    1,
1546         .netns_ok =     1,
1547 };
1548
1549 static __net_init int ipv4_mib_init_net(struct net *net)
1550 {
1551         if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1552                           sizeof(struct tcp_mib),
1553                           __alignof__(struct tcp_mib)) < 0)
1554                 goto err_tcp_mib;
1555         if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1556                           sizeof(struct ipstats_mib),
1557                           __alignof__(struct ipstats_mib)) < 0)
1558                 goto err_ip_mib;
1559         if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1560                           sizeof(struct linux_mib),
1561                           __alignof__(struct linux_mib)) < 0)
1562                 goto err_net_mib;
1563         if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1564                           sizeof(struct udp_mib),
1565                           __alignof__(struct udp_mib)) < 0)
1566                 goto err_udp_mib;
1567         if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1568                           sizeof(struct udp_mib),
1569                           __alignof__(struct udp_mib)) < 0)
1570                 goto err_udplite_mib;
1571         if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1572                           sizeof(struct icmp_mib),
1573                           __alignof__(struct icmp_mib)) < 0)
1574                 goto err_icmp_mib;
1575         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1576                                               GFP_KERNEL);
1577         if (!net->mib.icmpmsg_statistics)
1578                 goto err_icmpmsg_mib;
1579
1580         tcp_mib_init(net);
1581         return 0;
1582
1583 err_icmpmsg_mib:
1584         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1585 err_icmp_mib:
1586         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1587 err_udplite_mib:
1588         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1589 err_udp_mib:
1590         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1591 err_net_mib:
1592         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1593 err_ip_mib:
1594         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1595 err_tcp_mib:
1596         return -ENOMEM;
1597 }
1598
1599 static __net_exit void ipv4_mib_exit_net(struct net *net)
1600 {
1601         kfree(net->mib.icmpmsg_statistics);
1602         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1603         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1604         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1605         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1606         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1607         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1608 }
1609
1610 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1611         .init = ipv4_mib_init_net,
1612         .exit = ipv4_mib_exit_net,
1613 };
1614
1615 static int __init init_ipv4_mibs(void)
1616 {
1617         return register_pernet_subsys(&ipv4_mib_ops);
1618 }
1619
1620 static int ipv4_proc_init(void);
1621
1622 /*
1623  *      IP protocol layer initialiser
1624  */
1625
1626 static struct packet_type ip_packet_type __read_mostly = {
1627         .type = cpu_to_be16(ETH_P_IP),
1628         .func = ip_rcv,
1629         .gso_send_check = inet_gso_send_check,
1630         .gso_segment = inet_gso_segment,
1631         .gro_receive = inet_gro_receive,
1632         .gro_complete = inet_gro_complete,
1633 };
1634
1635 static int __init inet_init(void)
1636 {
1637         struct sk_buff *dummy_skb;
1638         struct inet_protosw *q;
1639         struct list_head *r;
1640         int rc = -EINVAL;
1641
1642         BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1643
1644         sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1645         if (!sysctl_local_reserved_ports)
1646                 goto out;
1647
1648         rc = proto_register(&tcp_prot, 1);
1649         if (rc)
1650                 goto out_free_reserved_ports;
1651
1652         rc = proto_register(&udp_prot, 1);
1653         if (rc)
1654                 goto out_unregister_tcp_proto;
1655
1656         rc = proto_register(&raw_prot, 1);
1657         if (rc)
1658                 goto out_unregister_udp_proto;
1659
1660         rc = proto_register(&ping_prot, 1);
1661         if (rc)
1662                 goto out_unregister_raw_proto;
1663
1664         /*
1665          *      Tell SOCKET that we are alive...
1666          */
1667
1668         (void)sock_register(&inet_family_ops);
1669
1670 #ifdef CONFIG_SYSCTL
1671         ip_static_sysctl_init();
1672 #endif
1673
1674         tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
1675
1676         /*
1677          *      Add all the base protocols.
1678          */
1679
1680         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1681                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1682         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1683                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1684         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1685                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1686 #ifdef CONFIG_IP_MULTICAST
1687         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1688                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1689 #endif
1690
1691         /* Register the socket-side information for inet_create. */
1692         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1693                 INIT_LIST_HEAD(r);
1694
1695         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1696                 inet_register_protosw(q);
1697
1698         /*
1699          *      Set the ARP module up
1700          */
1701
1702         arp_init();
1703
1704         /*
1705          *      Set the IP module up
1706          */
1707
1708         ip_init();
1709
1710         tcp_v4_init();
1711
1712         /* Setup TCP slab cache for open requests. */
1713         tcp_init();
1714
1715         /* Setup UDP memory threshold */
1716         udp_init();
1717
1718         /* Add UDP-Lite (RFC 3828) */
1719         udplite4_register();
1720
1721         ping_init();
1722
1723         /*
1724          *      Set the ICMP layer up
1725          */
1726
1727         if (icmp_init() < 0)
1728                 panic("Failed to create the ICMP control socket.\n");
1729
1730         /*
1731          *      Initialise the multicast router
1732          */
1733 #if defined(CONFIG_IP_MROUTE)
1734         if (ip_mr_init())
1735                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1736 #endif
1737         /*
1738          *      Initialise per-cpu ipv4 mibs
1739          */
1740
1741         if (init_ipv4_mibs())
1742                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1743
1744         ipv4_proc_init();
1745
1746         ipfrag_init();
1747
1748         dev_add_pack(&ip_packet_type);
1749
1750         rc = 0;
1751 out:
1752         return rc;
1753 out_unregister_raw_proto:
1754         proto_unregister(&raw_prot);
1755 out_unregister_udp_proto:
1756         proto_unregister(&udp_prot);
1757 out_unregister_tcp_proto:
1758         proto_unregister(&tcp_prot);
1759 out_free_reserved_ports:
1760         kfree(sysctl_local_reserved_ports);
1761         goto out;
1762 }
1763
1764 fs_initcall(inet_init);
1765
1766 /* ------------------------------------------------------------------------ */
1767
1768 #ifdef CONFIG_PROC_FS
1769 static int __init ipv4_proc_init(void)
1770 {
1771         int rc = 0;
1772
1773         if (raw_proc_init())
1774                 goto out_raw;
1775         if (tcp4_proc_init())
1776                 goto out_tcp;
1777         if (udp4_proc_init())
1778                 goto out_udp;
1779         if (ping_proc_init())
1780                 goto out_ping;
1781         if (ip_misc_proc_init())
1782                 goto out_misc;
1783 out:
1784         return rc;
1785 out_misc:
1786         ping_proc_exit();
1787 out_ping:
1788         udp4_proc_exit();
1789 out_udp:
1790         tcp4_proc_exit();
1791 out_tcp:
1792         raw_proc_exit();
1793 out_raw:
1794         rc = -ENOMEM;
1795         goto out;
1796 }
1797
1798 #else /* CONFIG_PROC_FS */
1799 static int __init ipv4_proc_init(void)
1800 {
1801         return 0;
1802 }
1803 #endif /* CONFIG_PROC_FS */
1804
1805 MODULE_ALIAS_NETPROTO(PF_INET);
1806