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 #ifdef CONFIG_ANDROID_PARANOID_NETWORK
 122 #include <linux/android_aid.h>
 123
 124 static inline int current_has_network(void)
 125 {
 126         return in_egroup_p(AID_INET) || capable(CAP_NET_RAW);
 127 }
 128 #else
 129 static inline int current_has_network(void)
 130 {
 131         return 1;
 132 }
 133 #endif
 134
 135 /* The inetsw table contains everything that inet_create needs to
 136  * build a new socket.
 137  */
 138 static struct list_head inetsw[SOCK_MAX];
 139 static DEFINE_SPINLOCK(inetsw_lock);
 140
 141 struct ipv4_config ipv4_config;
 142 EXPORT_SYMBOL(ipv4_config);
 143
 144 /* New destruction routine */
 145
 146 void inet_sock_destruct(struct sock *sk)
 147 {
 148         struct inet_sock *inet = inet_sk(sk);
 149
 150         __skb_queue_purge(&sk->sk_receive_queue);
 151         __skb_queue_purge(&sk->sk_error_queue);
 152
 153         sk_mem_reclaim(sk);
 154
 155         if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
 156                 pr_err("Attempt to release TCP socket in state %d %p\n",
 157                        sk->sk_state, sk);
 158                 return;
 159         }
 160         if (!sock_flag(sk, SOCK_DEAD)) {
 161                 pr_err("Attempt to release alive inet socket %p\n", sk);
 162                 return;
 163         }
 164
 165         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
 166         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
 167         WARN_ON(sk->sk_wmem_queued);
 168         WARN_ON(sk->sk_forward_alloc);
 169
 170         kfree(rcu_dereference_protected(inet->inet_opt, 1));
 171         dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
 172         sk_refcnt_debug_dec(sk);
 173 }
 174 EXPORT_SYMBOL(inet_sock_destruct);
 175
 176 /*
 177  *      The routines beyond this point handle the behaviour of an AF_INET
 178  *      socket object. Mostly it punts to the subprotocols of IP to do
 179  *      the work.
 180  */
 181
 182 /*
 183  *      Automatically bind an unbound socket.
 184  */
 185
 186 static int inet_autobind(struct sock *sk)
 187 {
 188         struct inet_sock *inet;
 189         /* We may need to bind the socket. */
 190         lock_sock(sk);
 191         inet = inet_sk(sk);
 192         if (!inet->inet_num) {
 193                 if (sk->sk_prot->get_port(sk, 0)) {
 194                         release_sock(sk);
 195                         return -EAGAIN;
 196                 }
 197                 inet->inet_sport = htons(inet->inet_num);
 198         }
 199         release_sock(sk);
 200         return 0;
 201 }
 202
 203 /*
 204  *      Move a socket into listening state.
 205  */
 206 int inet_listen(struct socket *sock, int backlog)
 207 {
 208         struct sock *sk = sock->sk;
 209         unsigned char old_state;
 210         int err;
 211
 212         lock_sock(sk);
 213
 214         err = -EINVAL;
 215         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
 216                 goto out;
 217
 218         old_state = sk->sk_state;
 219         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 220                 goto out;
 221
 222         /* Really, if the socket is already in listen state
 223          * we can only allow the backlog to be adjusted.
 224          */
 225         if (old_state != TCP_LISTEN) {
 226                 err = inet_csk_listen_start(sk, backlog);
 227                 if (err)
 228                         goto out;
 229         }
 230         sk->sk_max_ack_backlog = backlog;
 231         err = 0;
 232
 233 out:
 234         release_sock(sk);
 235         return err;
 236 }
 237 EXPORT_SYMBOL(inet_listen);
 238
 239 u32 inet_ehash_secret __read_mostly;
 240 EXPORT_SYMBOL(inet_ehash_secret);
 241
 242 u32 ipv6_hash_secret __read_mostly;
 243 EXPORT_SYMBOL(ipv6_hash_secret);
 244
 245 /*
 246  * inet_ehash_secret must be set exactly once, and to a non nul value
 247  * ipv6_hash_secret must be set exactly once.
 248  */
 249 void build_ehash_secret(void)
 250 {
 251         u32 rnd;
 252
 253         do {
 254                 get_random_bytes(&rnd, sizeof(rnd));
 255         } while (rnd == 0);
 256
 257         if (cmpxchg(&inet_ehash_secret, 0, rnd) == 0)
 258                 get_random_bytes(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
 259 }
 260 EXPORT_SYMBOL(build_ehash_secret);
 261
 262 static inline int inet_netns_ok(struct net *net, int protocol)
 263 {
 264         int hash;
 265         const struct net_protocol *ipprot;
 266
 267         if (net_eq(net, &init_net))
 268                 return 1;
 269
 270         hash = protocol & (MAX_INET_PROTOS - 1);
 271         ipprot = rcu_dereference(inet_protos[hash]);
 272
 273         if (ipprot == NULL)
 274                 /* raw IP is OK */
 275                 return 1;
 276         return ipprot->netns_ok;
 277 }
 278
 279
 280 /*
 281  *      Create an inet socket.
 282  */
 283
 284 static int inet_create(struct net *net, struct socket *sock, int protocol,
 285                        int kern)
 286 {
 287         struct sock *sk;
 288         struct inet_protosw *answer;
 289         struct inet_sock *inet;
 290         struct proto *answer_prot;
 291         unsigned char answer_flags;
 292         char answer_no_check;
 293         int try_loading_module = 0;
 294         int err;
 295
 296         if (!current_has_network())
 297                 return -EACCES;
 298
 299         if (unlikely(!inet_ehash_secret))
 300                 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
 301                         build_ehash_secret();
 302
 303         sock->state = SS_UNCONNECTED;
 304
 305         /* Look for the requested type/protocol pair. */
 306 lookup_protocol:
 307         err = -ESOCKTNOSUPPORT;
 308         rcu_read_lock();
 309         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 310
 311                 err = 0;
 312                 /* Check the non-wild match. */
 313                 if (protocol == answer->protocol) {
 314                         if (protocol != IPPROTO_IP)
 315                                 break;
 316                 } else {
 317                         /* Check for the two wild cases. */
 318                         if (IPPROTO_IP == protocol) {
 319                                 protocol = answer->protocol;
 320                                 break;
 321                         }
 322                         if (IPPROTO_IP == answer->protocol)
 323                                 break;
 324                 }
 325                 err = -EPROTONOSUPPORT;
 326         }
 327
 328         if (unlikely(err)) {
 329                 if (try_loading_module < 2) {
 330                         rcu_read_unlock();
 331                         /*
 332                          * Be more specific, e.g. net-pf-2-proto-132-type-1
 333                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 334                          */
 335                         if (++try_loading_module == 1)
 336                                 request_module("net-pf-%d-proto-%d-type-%d",
 337                                                PF_INET, protocol, sock->type);
 338                         /*
 339                          * Fall back to generic, e.g. net-pf-2-proto-132
 340                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 341                          */
 342                         else
 343                                 request_module("net-pf-%d-proto-%d",
 344                                                PF_INET, protocol);
 345                         goto lookup_protocol;
 346                 } else
 347                         goto out_rcu_unlock;
 348         }
 349
 350         err = -EPERM;
 351         if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
 352                 goto out_rcu_unlock;
 353
 354         err = -EAFNOSUPPORT;
 355         if (!inet_netns_ok(net, protocol))
 356                 goto out_rcu_unlock;
 357
 358         sock->ops = answer->ops;
 359         answer_prot = answer->prot;
 360         answer_no_check = answer->no_check;
 361         answer_flags = answer->flags;
 362         rcu_read_unlock();
 363
 364         WARN_ON(answer_prot->slab == NULL);
 365
 366         err = -ENOBUFS;
 367         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
 368         if (sk == NULL)
 369                 goto out;
 370
 371         err = 0;
 372         sk->sk_no_check = answer_no_check;
 373         if (INET_PROTOSW_REUSE & answer_flags)
 374                 sk->sk_reuse = 1;
 375
 376         inet = inet_sk(sk);
 377         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 378
 379         inet->nodefrag = 0;
 380
 381         if (SOCK_RAW == sock->type) {
 382                 inet->inet_num = protocol;
 383                 if (IPPROTO_RAW == protocol)
 384                         inet->hdrincl = 1;
 385         }
 386
 387         if (ipv4_config.no_pmtu_disc)
 388                 inet->pmtudisc = IP_PMTUDISC_DONT;
 389         else
 390                 inet->pmtudisc = IP_PMTUDISC_WANT;
 391
 392         inet->inet_id = 0;
 393
 394         sock_init_data(sock, sk);
 395
 396         sk->sk_destruct    = inet_sock_destruct;
 397         sk->sk_protocol    = protocol;
 398         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 399
 400         inet->uc_ttl    = -1;
 401         inet->mc_loop   = 1;
 402         inet->mc_ttl    = 1;
 403         inet->mc_all    = 1;
 404         inet->mc_index  = 0;
 405         inet->mc_list   = NULL;
 406
 407         sk_refcnt_debug_inc(sk);
 408
 409         if (inet->inet_num) {
 410                 /* It assumes that any protocol which allows
 411                  * the user to assign a number at socket
 412                  * creation time automatically
 413                  * shares.
 414                  */
 415                 inet->inet_sport = htons(inet->inet_num);
 416                 /* Add to protocol hash chains. */
 417                 sk->sk_prot->hash(sk);
 418         }
 419
 420         if (sk->sk_prot->init) {
 421                 err = sk->sk_prot->init(sk);
 422                 if (err)
 423                         sk_common_release(sk);
 424         }
 425 out:
 426         return err;
 427 out_rcu_unlock:
 428         rcu_read_unlock();
 429         goto out;
 430 }
 431
 432
 433 /*
 434  *      The peer socket should always be NULL (or else). When we call this
 435  *      function we are destroying the object and from then on nobody
 436  *      should refer to it.
 437  */
 438 int inet_release(struct socket *sock)
 439 {
 440         struct sock *sk = sock->sk;
 441
 442         if (sk) {
 443                 long timeout;
 444
 445                 sock_rps_reset_flow(sk);
 446
 447                 /* Applications forget to leave groups before exiting */
 448                 ip_mc_drop_socket(sk);
 449
 450                 /* If linger is set, we don't return until the close
 451                  * is complete.  Otherwise we return immediately. The
 452                  * actually closing is done the same either way.
 453                  *
 454                  * If the close is due to the process exiting, we never
 455                  * linger..
 456                  */
 457                 timeout = 0;
 458                 if (sock_flag(sk, SOCK_LINGER) &&
 459                     !(current->flags & PF_EXITING))
 460                         timeout = sk->sk_lingertime;
 461                 sock->sk = NULL;
 462                 sk->sk_prot->close(sk, timeout);
 463         }
 464         return 0;
 465 }
 466 EXPORT_SYMBOL(inet_release);
 467
 468 /* It is off by default, see below. */
 469 int sysctl_ip_nonlocal_bind __read_mostly;
 470 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
 471
 472 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 473 {
 474         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 475         struct sock *sk = sock->sk;
 476         struct inet_sock *inet = inet_sk(sk);
 477         unsigned short snum;
 478         int chk_addr_ret;
 479         int err;
 480
 481         /* If the socket has its own bind function then use it. (RAW) */
 482         if (sk->sk_prot->bind) {
 483                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
 484                 goto out;
 485         }
 486         err = -EINVAL;
 487         if (addr_len < sizeof(struct sockaddr_in))
 488                 goto out;
 489
 490         if (addr->sin_family != AF_INET) {
 491                 err = -EAFNOSUPPORT;
 492                 goto out;
 493         }
 494
 495         chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
 496
 497         /* Not specified by any standard per-se, however it breaks too
 498          * many applications when removed.  It is unfortunate since
 499          * allowing applications to make a non-local bind solves
 500          * several problems with systems using dynamic addressing.
 501          * (ie. your servers still start up even if your ISDN link
 502          *  is temporarily down)
 503          */
 504         err = -EADDRNOTAVAIL;
 505         if (!sysctl_ip_nonlocal_bind &&
 506             !(inet->freebind || inet->transparent) &&
 507             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
 508             chk_addr_ret != RTN_LOCAL &&
 509             chk_addr_ret != RTN_MULTICAST &&
 510             chk_addr_ret != RTN_BROADCAST)
 511                 goto out;
 512
 513         snum = ntohs(addr->sin_port);
 514         err = -EACCES;
 515         if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
 516                 goto out;
 517
 518         /*      We keep a pair of addresses. rcv_saddr is the one
 519          *      used by hash lookups, and saddr is used for transmit.
 520          *
 521          *      In the BSD API these are the same except where it
 522          *      would be illegal to use them (multicast/broadcast) in
 523          *      which case the sending device address is used.
 524          */
 525         lock_sock(sk);
 526
 527         /* Check these errors (active socket, double bind). */
 528         err = -EINVAL;
 529         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
 530                 goto out_release_sock;
 531
 532         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
 533         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 534                 inet->inet_saddr = 0;  /* Use device */
 535
 536         /* Make sure we are allowed to bind here. */
 537         if (sk->sk_prot->get_port(sk, snum)) {
 538                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
 539                 err = -EADDRINUSE;
 540                 goto out_release_sock;
 541         }
 542
 543         if (inet->inet_rcv_saddr)
 544                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 545         if (snum)
 546                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 547         inet->inet_sport = htons(inet->inet_num);
 548         inet->inet_daddr = 0;
 549         inet->inet_dport = 0;
 550         sk_dst_reset(sk);
 551         err = 0;
 552 out_release_sock:
 553         release_sock(sk);
 554 out:
 555         return err;
 556 }
 557 EXPORT_SYMBOL(inet_bind);
 558
 559 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
 560                        int addr_len, int flags)
 561 {
 562         struct sock *sk = sock->sk;
 563
 564         if (addr_len < sizeof(uaddr->sa_family))
 565                 return -EINVAL;
 566         if (uaddr->sa_family == AF_UNSPEC)
 567                 return sk->sk_prot->disconnect(sk, flags);
 568
 569         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
 570                 return -EAGAIN;
 571         return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
 572 }
 573 EXPORT_SYMBOL(inet_dgram_connect);
 574
 575 static long inet_wait_for_connect(struct sock *sk, long timeo)
 576 {
 577         DEFINE_WAIT(wait);
 578
 579         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 580
 581         /* Basic assumption: if someone sets sk->sk_err, he _must_
 582          * change state of the socket from TCP_SYN_*.
 583          * Connect() does not allow to get error notifications
 584          * without closing the socket.
 585          */
 586         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 587                 release_sock(sk);
 588                 timeo = schedule_timeout(timeo);
 589                 lock_sock(sk);
 590                 if (signal_pending(current) || !timeo)
 591                         break;
 592                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 593         }
 594         finish_wait(sk_sleep(sk), &wait);
 595         return timeo;
 596 }
 597
 598 /*
 599  *      Connect to a remote host. There is regrettably still a little
 600  *      TCP 'magic' in here.
 601  */
 602 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 603                         int addr_len, int flags)
 604 {
 605         struct sock *sk = sock->sk;
 606         int err;
 607         long timeo;
 608
 609         if (addr_len < sizeof(uaddr->sa_family))
 610                 return -EINVAL;
 611
 612         lock_sock(sk);
 613
 614         if (uaddr->sa_family == AF_UNSPEC) {
 615                 err = sk->sk_prot->disconnect(sk, flags);
 616                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 617                 goto out;
 618         }
 619
 620         switch (sock->state) {
 621         default:
 622                 err = -EINVAL;
 623                 goto out;
 624         case SS_CONNECTED:
 625                 err = -EISCONN;
 626                 goto out;
 627         case SS_CONNECTING:
 628                 err = -EALREADY;
 629                 /* Fall out of switch with err, set for this state */
 630                 break;
 631         case SS_UNCONNECTED:
 632                 err = -EISCONN;
 633                 if (sk->sk_state != TCP_CLOSE)
 634                         goto out;
 635
 636                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
 637                 if (err < 0)
 638                         goto out;
 639
 640                 sock->state = SS_CONNECTING;
 641
 642                 /* Just entered SS_CONNECTING state; the only
 643                  * difference is that return value in non-blocking
 644                  * case is EINPROGRESS, rather than EALREADY.
 645                  */
 646                 err = -EINPROGRESS;
 647                 break;
 648         }
 649
 650         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 651
 652         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 653                 /* Error code is set above */
 654                 if (!timeo || !inet_wait_for_connect(sk, timeo))
 655                         goto out;
 656
 657                 err = sock_intr_errno(timeo);
 658                 if (signal_pending(current))
 659                         goto out;
 660         }
 661
 662         /* Connection was closed by RST, timeout, ICMP error
 663          * or another process disconnected us.
 664          */
 665         if (sk->sk_state == TCP_CLOSE)
 666                 goto sock_error;
 667
 668         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 669          * and error was received after socket entered established state.
 670          * Hence, it is handled normally after connect() return successfully.
 671          */
 672
 673         sock->state = SS_CONNECTED;
 674         err = 0;
 675 out:
 676         release_sock(sk);
 677         return err;
 678
 679 sock_error:
 680         err = sock_error(sk) ? : -ECONNABORTED;
 681         sock->state = SS_UNCONNECTED;
 682         if (sk->sk_prot->disconnect(sk, flags))
 683                 sock->state = SS_DISCONNECTING;
 684         goto out;
 685 }
 686 EXPORT_SYMBOL(inet_stream_connect);
 687
 688 /*
 689  *      Accept a pending connection. The TCP layer now gives BSD semantics.
 690  */
 691
 692 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
 693 {
 694         struct sock *sk1 = sock->sk;
 695         int err = -EINVAL;
 696         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
 697
 698         if (!sk2)
 699                 goto do_err;
 700
 701         lock_sock(sk2);
 702
 703         sock_rps_record_flow(sk2);
 704         WARN_ON(!((1 << sk2->sk_state) &
 705                   (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 706
 707         sock_graft(sk2, newsock);
 708
 709         newsock->state = SS_CONNECTED;
 710         err = 0;
 711         release_sock(sk2);
 712 do_err:
 713         return err;
 714 }
 715 EXPORT_SYMBOL(inet_accept);
 716
 717
 718 /*
 719  *      This does both peername and sockname.
 720  */
 721 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 722                         int *uaddr_len, int peer)
 723 {
 724         struct sock *sk         = sock->sk;
 725         struct inet_sock *inet  = inet_sk(sk);
 726         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 727
 728         sin->sin_family = AF_INET;
 729         if (peer) {
 730                 if (!inet->inet_dport ||
 731                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 732                      peer == 1))
 733                         return -ENOTCONN;
 734                 sin->sin_port = inet->inet_dport;
 735                 sin->sin_addr.s_addr = inet->inet_daddr;
 736         } else {
 737                 __be32 addr = inet->inet_rcv_saddr;
 738                 if (!addr)
 739                         addr = inet->inet_saddr;
 740                 sin->sin_port = inet->inet_sport;
 741                 sin->sin_addr.s_addr = addr;
 742         }
 743         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 744         *uaddr_len = sizeof(*sin);
 745         return 0;
 746 }
 747 EXPORT_SYMBOL(inet_getname);
 748
 749 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 750                  size_t size)
 751 {
 752         struct sock *sk = sock->sk;
 753
 754         sock_rps_record_flow(sk);
 755
 756         /* We may need to bind the socket. */
 757         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 758             inet_autobind(sk))
 759                 return -EAGAIN;
 760
 761         return sk->sk_prot->sendmsg(iocb, sk, msg, size);
 762 }
 763 EXPORT_SYMBOL(inet_sendmsg);
 764
 765 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 766                       size_t size, int flags)
 767 {
 768         struct sock *sk = sock->sk;
 769
 770         sock_rps_record_flow(sk);
 771
 772         /* We may need to bind the socket. */
 773         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 774             inet_autobind(sk))
 775                 return -EAGAIN;
 776
 777         if (sk->sk_prot->sendpage)
 778                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
 779         return sock_no_sendpage(sock, page, offset, size, flags);
 780 }
 781 EXPORT_SYMBOL(inet_sendpage);
 782
 783 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 784                  size_t size, int flags)
 785 {
 786         struct sock *sk = sock->sk;
 787         int addr_len = 0;
 788         int err;
 789
 790         sock_rps_record_flow(sk);
 791
 792         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
 793                                    flags & ~MSG_DONTWAIT, &addr_len);
 794         if (err >= 0)
 795                 msg->msg_namelen = addr_len;
 796         return err;
 797 }
 798 EXPORT_SYMBOL(inet_recvmsg);
 799
 800 int inet_shutdown(struct socket *sock, int how)
 801 {
 802         struct sock *sk = sock->sk;
 803         int err = 0;
 804
 805         /* This should really check to make sure
 806          * the socket is a TCP socket. (WHY AC...)
 807          */
 808         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 809                        1->2 bit 2 snds.
 810                        2->3 */
 811         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 812                 return -EINVAL;
 813
 814         lock_sock(sk);
 815         if (sock->state == SS_CONNECTING) {
 816                 if ((1 << sk->sk_state) &
 817                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 818                         sock->state = SS_DISCONNECTING;
 819                 else
 820                         sock->state = SS_CONNECTED;
 821         }
 822
 823         switch (sk->sk_state) {
 824         case TCP_CLOSE:
 825                 err = -ENOTCONN;
 826                 /* Hack to wake up other listeners, who can poll for
 827                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
 828         default:
 829                 sk->sk_shutdown |= how;
 830                 if (sk->sk_prot->shutdown)
 831                         sk->sk_prot->shutdown(sk, how);
 832                 break;
 833
 834         /* Remaining two branches are temporary solution for missing
 835          * close() in multithreaded environment. It is _not_ a good idea,
 836          * but we have no choice until close() is repaired at VFS level.
 837          */
 838         case TCP_LISTEN:
 839                 if (!(how & RCV_SHUTDOWN))
 840                         break;
 841                 /* Fall through */
 842         case TCP_SYN_SENT:
 843                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 844                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 845                 break;
 846         }
 847
 848         /* Wake up anyone sleeping in poll. */
 849         sk->sk_state_change(sk);
 850         release_sock(sk);
 851         return err;
 852 }
 853 EXPORT_SYMBOL(inet_shutdown);
 854
 855 /*
 856  *      ioctl() calls you can issue on an INET socket. Most of these are
 857  *      device configuration and stuff and very rarely used. Some ioctls
 858  *      pass on to the socket itself.
 859  *
 860  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 861  *      loads the devconfigure module does its configuring and unloads it.
 862  *      There's a good 20K of config code hanging around the kernel.
 863  */
 864
 865 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 866 {
 867         struct sock *sk = sock->sk;
 868         int err = 0;
 869         struct net *net = sock_net(sk);
 870
 871         switch (cmd) {
 872         case SIOCGSTAMP:
 873                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
 874                 break;
 875         case SIOCGSTAMPNS:
 876                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
 877                 break;
 878         case SIOCADDRT:
 879         case SIOCDELRT:
 880         case SIOCRTMSG:
 881                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
 882                 break;
 883         case SIOCDARP:
 884         case SIOCGARP:
 885         case SIOCSARP:
 886                 err = arp_ioctl(net, cmd, (void __user *)arg);
 887                 break;
 888         case SIOCGIFADDR:
 889         case SIOCSIFADDR:
 890         case SIOCGIFBRDADDR:
 891         case SIOCSIFBRDADDR:
 892         case SIOCGIFNETMASK:
 893         case SIOCSIFNETMASK:
 894         case SIOCGIFDSTADDR:
 895         case SIOCSIFDSTADDR:
 896         case SIOCSIFPFLAGS:
 897         case SIOCGIFPFLAGS:
 898         case SIOCSIFFLAGS:
 899         case SIOCKILLADDR:
 900                 err = devinet_ioctl(net, cmd, (void __user *)arg);
 901                 break;
 902         default:
 903                 if (sk->sk_prot->ioctl)
 904                         err = sk->sk_prot->ioctl(sk, cmd, arg);
 905                 else
 906                         err = -ENOIOCTLCMD;
 907                 break;
 908         }
 909         return err;
 910 }
 911 EXPORT_SYMBOL(inet_ioctl);
 912
 913 #ifdef CONFIG_COMPAT
 914 int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 915 {
 916         struct sock *sk = sock->sk;
 917         int err = -ENOIOCTLCMD;
 918
 919         if (sk->sk_prot->compat_ioctl)
 920                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
 921
 922         return err;
 923 }
 924 #endif
 925
 926 const struct proto_ops inet_stream_ops = {
 927         .family            = PF_INET,
 928         .owner             = THIS_MODULE,
 929         .release           = inet_release,
 930         .bind              = inet_bind,
 931         .connect           = inet_stream_connect,
 932         .socketpair        = sock_no_socketpair,
 933         .accept            = inet_accept,
 934         .getname           = inet_getname,
 935         .poll              = tcp_poll,
 936         .ioctl             = inet_ioctl,
 937         .listen            = inet_listen,
 938         .shutdown          = inet_shutdown,
 939         .setsockopt        = sock_common_setsockopt,
 940         .getsockopt        = sock_common_getsockopt,
 941         .sendmsg           = inet_sendmsg,
 942         .recvmsg           = inet_recvmsg,
 943         .mmap              = sock_no_mmap,
 944         .sendpage          = inet_sendpage,
 945         .splice_read       = tcp_splice_read,
 946 #ifdef CONFIG_COMPAT
 947         .compat_setsockopt = compat_sock_common_setsockopt,
 948         .compat_getsockopt = compat_sock_common_getsockopt,
 949         .compat_ioctl      = inet_compat_ioctl,
 950 #endif
 951 };
 952 EXPORT_SYMBOL(inet_stream_ops);
 953
 954 const struct proto_ops inet_dgram_ops = {
 955         .family            = PF_INET,
 956         .owner             = THIS_MODULE,
 957         .release           = inet_release,
 958         .bind              = inet_bind,
 959         .connect           = inet_dgram_connect,
 960         .socketpair        = sock_no_socketpair,
 961         .accept            = sock_no_accept,
 962         .getname           = inet_getname,
 963         .poll              = udp_poll,
 964         .ioctl             = inet_ioctl,
 965         .listen            = sock_no_listen,
 966         .shutdown          = inet_shutdown,
 967         .setsockopt        = sock_common_setsockopt,
 968         .getsockopt        = sock_common_getsockopt,
 969         .sendmsg           = inet_sendmsg,
 970         .recvmsg           = inet_recvmsg,
 971         .mmap              = sock_no_mmap,
 972         .sendpage          = inet_sendpage,
 973 #ifdef CONFIG_COMPAT
 974         .compat_setsockopt = compat_sock_common_setsockopt,
 975         .compat_getsockopt = compat_sock_common_getsockopt,
 976         .compat_ioctl      = inet_compat_ioctl,
 977 #endif
 978 };
 979 EXPORT_SYMBOL(inet_dgram_ops);
 980
 981 /*
 982  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
 983  * udp_poll
 984  */
 985 static const struct proto_ops inet_sockraw_ops = {
 986         .family            = PF_INET,
 987         .owner             = THIS_MODULE,
 988         .release           = inet_release,
 989         .bind              = inet_bind,
 990         .connect           = inet_dgram_connect,
 991         .socketpair        = sock_no_socketpair,
 992         .accept            = sock_no_accept,
 993         .getname           = inet_getname,
 994         .poll              = datagram_poll,
 995         .ioctl             = inet_ioctl,
 996         .listen            = sock_no_listen,
 997         .shutdown          = inet_shutdown,
 998         .setsockopt        = sock_common_setsockopt,
 999         .getsockopt        = sock_common_getsockopt,
1000         .sendmsg           = inet_sendmsg,
1001         .recvmsg           = inet_recvmsg,
1002         .mmap              = sock_no_mmap,
1003         .sendpage          = inet_sendpage,
1004 #ifdef CONFIG_COMPAT
1005         .compat_setsockopt = compat_sock_common_setsockopt,
1006         .compat_getsockopt = compat_sock_common_getsockopt,
1007         .compat_ioctl      = inet_compat_ioctl,
1008 #endif
1009 };
1010
1011 static const struct net_proto_family inet_family_ops = {
1012         .family = PF_INET,
1013         .create = inet_create,
1014         .owner  = THIS_MODULE,
1015 };
1016
1017 /* Upon startup we insert all the elements in inetsw_array[] into
1018  * the linked list inetsw.
1019  */
1020 static struct inet_protosw inetsw_array[] =
1021 {
1022         {
1023                 .type =       SOCK_STREAM,
1024                 .protocol =   IPPROTO_TCP,
1025                 .prot =       &tcp_prot,
1026                 .ops =        &inet_stream_ops,
1027                 .no_check =   0,
1028                 .flags =      INET_PROTOSW_PERMANENT |
1029                               INET_PROTOSW_ICSK,
1030         },
1031
1032         {
1033                 .type =       SOCK_DGRAM,
1034                 .protocol =   IPPROTO_UDP,
1035                 .prot =       &udp_prot,
1036                 .ops =        &inet_dgram_ops,
1037                 .no_check =   UDP_CSUM_DEFAULT,
1038                 .flags =      INET_PROTOSW_PERMANENT,
1039        },
1040
1041        {
1042                 .type =       SOCK_DGRAM,
1043                 .protocol =   IPPROTO_ICMP,
1044                 .prot =       &ping_prot,
1045                 .ops =        &inet_dgram_ops,
1046                 .no_check =   UDP_CSUM_DEFAULT,
1047                 .flags =      INET_PROTOSW_REUSE,
1048        },
1049
1050        {
1051                .type =       SOCK_RAW,
1052                .protocol =   IPPROTO_IP,        /* wild card */
1053                .prot =       &raw_prot,
1054                .ops =        &inet_sockraw_ops,
1055                .no_check =   UDP_CSUM_DEFAULT,
1056                .flags =      INET_PROTOSW_REUSE,
1057        }
1058 };
1059
1060 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1061
1062 void inet_register_protosw(struct inet_protosw *p)
1063 {
1064         struct list_head *lh;
1065         struct inet_protosw *answer;
1066         int protocol = p->protocol;
1067         struct list_head *last_perm;
1068
1069         spin_lock_bh(&inetsw_lock);
1070
1071         if (p->type >= SOCK_MAX)
1072                 goto out_illegal;
1073
1074         /* If we are trying to override a permanent protocol, bail. */
1075         answer = NULL;
1076         last_perm = &inetsw[p->type];
1077         list_for_each(lh, &inetsw[p->type]) {
1078                 answer = list_entry(lh, struct inet_protosw, list);
1079
1080                 /* Check only the non-wild match. */
1081                 if (INET_PROTOSW_PERMANENT & answer->flags) {
1082                         if (protocol == answer->protocol)
1083                                 break;
1084                         last_perm = lh;
1085                 }
1086
1087                 answer = NULL;
1088         }
1089         if (answer)
1090                 goto out_permanent;
1091
1092         /* Add the new entry after the last permanent entry if any, so that
1093          * the new entry does not override a permanent entry when matched with
1094          * a wild-card protocol. But it is allowed to override any existing
1095          * non-permanent entry.  This means that when we remove this entry, the
1096          * system automatically returns to the old behavior.
1097          */
1098         list_add_rcu(&p->list, last_perm);
1099 out:
1100         spin_unlock_bh(&inetsw_lock);
1101
1102         return;
1103
1104 out_permanent:
1105         printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1106                protocol);
1107         goto out;
1108
1109 out_illegal:
1110         printk(KERN_ERR
1111                "Ignoring attempt to register invalid socket type %d.\n",
1112                p->type);
1113         goto out;
1114 }
1115 EXPORT_SYMBOL(inet_register_protosw);
1116
1117 void inet_unregister_protosw(struct inet_protosw *p)
1118 {
1119         if (INET_PROTOSW_PERMANENT & p->flags) {
1120                 printk(KERN_ERR
1121                        "Attempt to unregister permanent protocol %d.\n",
1122                        p->protocol);
1123         } else {
1124                 spin_lock_bh(&inetsw_lock);
1125                 list_del_rcu(&p->list);
1126                 spin_unlock_bh(&inetsw_lock);
1127
1128                 synchronize_net();
1129         }
1130 }
1131 EXPORT_SYMBOL(inet_unregister_protosw);
1132
1133 /*
1134  *      Shall we try to damage output packets if routing dev changes?
1135  */
1136
1137 int sysctl_ip_dynaddr __read_mostly;
1138
1139 static int inet_sk_reselect_saddr(struct sock *sk)
1140 {
1141         struct inet_sock *inet = inet_sk(sk);
1142         __be32 old_saddr = inet->inet_saddr;
1143         __be32 daddr = inet->inet_daddr;
1144         struct flowi4 *fl4;
1145         struct rtable *rt;
1146         __be32 new_saddr;
1147         struct ip_options_rcu *inet_opt;
1148
1149         inet_opt = rcu_dereference_protected(inet->inet_opt,
1150                                              sock_owned_by_user(sk));
1151         if (inet_opt && inet_opt->opt.srr)
1152                 daddr = inet_opt->opt.faddr;
1153
1154         /* Query new route. */
1155         fl4 = &inet->cork.fl.u.ip4;
1156         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1157                               sk->sk_bound_dev_if, sk->sk_protocol,
1158                               inet->inet_sport, inet->inet_dport, sk, false);
1159         if (IS_ERR(rt))
1160                 return PTR_ERR(rt);
1161
1162         sk_setup_caps(sk, &rt->dst);
1163
1164         new_saddr = fl4->saddr;
1165
1166         if (new_saddr == old_saddr)
1167                 return 0;
1168
1169         if (sysctl_ip_dynaddr > 1) {
1170                 printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1171                        __func__, &old_saddr, &new_saddr);
1172         }
1173
1174         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1175
1176         /*
1177          * XXX The only one ugly spot where we need to
1178          * XXX really change the sockets identity after
1179          * XXX it has entered the hashes. -DaveM
1180          *
1181          * Besides that, it does not check for connection
1182          * uniqueness. Wait for troubles.
1183          */
1184         __sk_prot_rehash(sk);
1185         return 0;
1186 }
1187
1188 int inet_sk_rebuild_header(struct sock *sk)
1189 {
1190         struct inet_sock *inet = inet_sk(sk);
1191         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1192         __be32 daddr;
1193         struct ip_options_rcu *inet_opt;
1194         struct flowi4 *fl4;
1195         int err;
1196
1197         /* Route is OK, nothing to do. */
1198         if (rt)
1199                 return 0;
1200
1201         /* Reroute. */
1202         rcu_read_lock();
1203         inet_opt = rcu_dereference(inet->inet_opt);
1204         daddr = inet->inet_daddr;
1205         if (inet_opt && inet_opt->opt.srr)
1206                 daddr = inet_opt->opt.faddr;
1207         rcu_read_unlock();
1208         fl4 = &inet->cork.fl.u.ip4;
1209         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1210                                    inet->inet_dport, inet->inet_sport,
1211                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1212                                    sk->sk_bound_dev_if);
1213         if (!IS_ERR(rt)) {
1214                 err = 0;
1215                 sk_setup_caps(sk, &rt->dst);
1216         } else {
1217                 err = PTR_ERR(rt);
1218
1219                 /* Routing failed... */
1220                 sk->sk_route_caps = 0;
1221                 /*
1222                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1223                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1224                  */
1225                 if (!sysctl_ip_dynaddr ||
1226                     sk->sk_state != TCP_SYN_SENT ||
1227                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1228                     (err = inet_sk_reselect_saddr(sk)) != 0)
1229                         sk->sk_err_soft = -err;
1230         }
1231
1232         return err;
1233 }
1234 EXPORT_SYMBOL(inet_sk_rebuild_header);
1235
1236 static int inet_gso_send_check(struct sk_buff *skb)
1237 {
1238         const struct iphdr *iph;
1239         const struct net_protocol *ops;
1240         int proto;
1241         int ihl;
1242         int err = -EINVAL;
1243
1244         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1245                 goto out;
1246
1247         iph = ip_hdr(skb);
1248         ihl = iph->ihl * 4;
1249         if (ihl < sizeof(*iph))
1250                 goto out;
1251
1252         if (unlikely(!pskb_may_pull(skb, ihl)))
1253                 goto out;
1254
1255         __skb_pull(skb, ihl);
1256         skb_reset_transport_header(skb);
1257         iph = ip_hdr(skb);
1258         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1259         err = -EPROTONOSUPPORT;
1260
1261         rcu_read_lock();
1262         ops = rcu_dereference(inet_protos[proto]);
1263         if (likely(ops && ops->gso_send_check))
1264                 err = ops->gso_send_check(skb);
1265         rcu_read_unlock();
1266
1267 out:
1268         return err;
1269 }
1270
1271 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, u32 features)
1272 {
1273         struct sk_buff *segs = ERR_PTR(-EINVAL);
1274         struct iphdr *iph;
1275         const struct net_protocol *ops;
1276         int proto;
1277         int ihl;
1278         int id;
1279         unsigned int offset = 0;
1280
1281         if (!(features & NETIF_F_V4_CSUM))
1282                 features &= ~NETIF_F_SG;
1283
1284         if (unlikely(skb_shinfo(skb)->gso_type &
1285                      ~(SKB_GSO_TCPV4 |
1286                        SKB_GSO_UDP |
1287                        SKB_GSO_DODGY |
1288                        SKB_GSO_TCP_ECN |
1289                        0)))
1290                 goto out;
1291
1292         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1293                 goto out;
1294
1295         iph = ip_hdr(skb);
1296         ihl = iph->ihl * 4;
1297         if (ihl < sizeof(*iph))
1298                 goto out;
1299
1300         if (unlikely(!pskb_may_pull(skb, ihl)))
1301                 goto out;
1302
1303         __skb_pull(skb, ihl);
1304         skb_reset_transport_header(skb);
1305         iph = ip_hdr(skb);
1306         id = ntohs(iph->id);
1307         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1308         segs = ERR_PTR(-EPROTONOSUPPORT);
1309
1310         rcu_read_lock();
1311         ops = rcu_dereference(inet_protos[proto]);
1312         if (likely(ops && ops->gso_segment))
1313                 segs = ops->gso_segment(skb, features);
1314         rcu_read_unlock();
1315
1316         if (!segs || IS_ERR(segs))
1317                 goto out;
1318
1319         skb = segs;
1320         do {
1321                 iph = ip_hdr(skb);
1322                 if (proto == IPPROTO_UDP) {
1323                         iph->id = htons(id);
1324                         iph->frag_off = htons(offset >> 3);
1325                         if (skb->next != NULL)
1326                                 iph->frag_off |= htons(IP_MF);
1327                         offset += (skb->len - skb->mac_len - iph->ihl * 4);
1328                 } else
1329                         iph->id = htons(id++);
1330                 iph->tot_len = htons(skb->len - skb->mac_len);
1331                 iph->check = 0;
1332                 iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1333         } while ((skb = skb->next));
1334
1335 out:
1336         return segs;
1337 }
1338
1339 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1340                                          struct sk_buff *skb)
1341 {
1342         const struct net_protocol *ops;
1343         struct sk_buff **pp = NULL;
1344         struct sk_buff *p;
1345         const struct iphdr *iph;
1346         unsigned int hlen;
1347         unsigned int off;
1348         unsigned int id;
1349         int flush = 1;
1350         int proto;
1351
1352         off = skb_gro_offset(skb);
1353         hlen = off + sizeof(*iph);
1354         iph = skb_gro_header_fast(skb, off);
1355         if (skb_gro_header_hard(skb, hlen)) {
1356                 iph = skb_gro_header_slow(skb, hlen, off);
1357                 if (unlikely(!iph))
1358                         goto out;
1359         }
1360
1361         proto = iph->protocol & (MAX_INET_PROTOS - 1);
1362
1363         rcu_read_lock();
1364         ops = rcu_dereference(inet_protos[proto]);
1365         if (!ops || !ops->gro_receive)
1366                 goto out_unlock;
1367
1368         if (*(u8 *)iph != 0x45)
1369                 goto out_unlock;
1370
1371         if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1372                 goto out_unlock;
1373
1374         id = ntohl(*(__be32 *)&iph->id);
1375         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1376         id >>= 16;
1377
1378         for (p = *head; p; p = p->next) {
1379                 struct iphdr *iph2;
1380
1381                 if (!NAPI_GRO_CB(p)->same_flow)
1382                         continue;
1383
1384                 iph2 = ip_hdr(p);
1385
1386                 if ((iph->protocol ^ iph2->protocol) |
1387                     (iph->tos ^ iph2->tos) |
1388                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1389                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1390                         NAPI_GRO_CB(p)->same_flow = 0;
1391                         continue;
1392                 }
1393
1394                 /* All fields must match except length and checksum. */
1395                 NAPI_GRO_CB(p)->flush |=
1396                         (iph->ttl ^ iph2->ttl) |
1397                         ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1398
1399                 NAPI_GRO_CB(p)->flush |= flush;
1400         }
1401
1402         NAPI_GRO_CB(skb)->flush |= flush;
1403         skb_gro_pull(skb, sizeof(*iph));
1404         skb_set_transport_header(skb, skb_gro_offset(skb));
1405
1406         pp = ops->gro_receive(head, skb);
1407
1408 out_unlock:
1409         rcu_read_unlock();
1410
1411 out:
1412         NAPI_GRO_CB(skb)->flush |= flush;
1413
1414         return pp;
1415 }
1416
1417 static int inet_gro_complete(struct sk_buff *skb)
1418 {
1419         const struct net_protocol *ops;
1420         struct iphdr *iph = ip_hdr(skb);
1421         int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1422         int err = -ENOSYS;
1423         __be16 newlen = htons(skb->len - skb_network_offset(skb));
1424
1425         csum_replace2(&iph->check, iph->tot_len, newlen);
1426         iph->tot_len = newlen;
1427
1428         rcu_read_lock();
1429         ops = rcu_dereference(inet_protos[proto]);
1430         if (WARN_ON(!ops || !ops->gro_complete))
1431                 goto out_unlock;
1432
1433         err = ops->gro_complete(skb);
1434
1435 out_unlock:
1436         rcu_read_unlock();
1437
1438         return err;
1439 }
1440
1441 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1442                          unsigned short type, unsigned char protocol,
1443                          struct net *net)
1444 {
1445         struct socket *sock;
1446         int rc = sock_create_kern(family, type, protocol, &sock);
1447
1448         if (rc == 0) {
1449                 *sk = sock->sk;
1450                 (*sk)->sk_allocation = GFP_ATOMIC;
1451                 /*
1452                  * Unhash it so that IP input processing does not even see it,
1453                  * we do not wish this socket to see incoming packets.
1454                  */
1455                 (*sk)->sk_prot->unhash(*sk);
1456
1457                 sk_change_net(*sk, net);
1458         }
1459         return rc;
1460 }
1461 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1462
1463 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1464 {
1465         unsigned long res = 0;
1466         int i;
1467
1468         for_each_possible_cpu(i) {
1469                 res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1470                 res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1471         }
1472         return res;
1473 }
1474 EXPORT_SYMBOL_GPL(snmp_fold_field);
1475
1476 #if BITS_PER_LONG==32
1477
1478 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1479 {
1480         u64 res = 0;
1481         int cpu;
1482
1483         for_each_possible_cpu(cpu) {
1484                 void *bhptr, *userptr;
1485                 struct u64_stats_sync *syncp;
1486                 u64 v_bh, v_user;
1487                 unsigned int start;
1488
1489                 /* first mib used by softirq context, we must use _bh() accessors */
1490                 bhptr = per_cpu_ptr(SNMP_STAT_BHPTR(mib), cpu);
1491                 syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1492                 do {
1493                         start = u64_stats_fetch_begin_bh(syncp);
1494                         v_bh = *(((u64 *) bhptr) + offt);
1495                 } while (u64_stats_fetch_retry_bh(syncp, start));
1496
1497                 /* second mib used in USER context */
1498                 userptr = per_cpu_ptr(SNMP_STAT_USRPTR(mib), cpu);
1499                 syncp = (struct u64_stats_sync *)(userptr + syncp_offset);
1500                 do {
1501                         start = u64_stats_fetch_begin(syncp);
1502                         v_user = *(((u64 *) userptr) + offt);
1503                 } while (u64_stats_fetch_retry(syncp, start));
1504
1505                 res += v_bh + v_user;
1506         }
1507         return res;
1508 }
1509 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1510 #endif
1511
1512 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1513 {
1514         BUG_ON(ptr == NULL);
1515         ptr[0] = __alloc_percpu(mibsize, align);
1516         if (!ptr[0])
1517                 goto err0;
1518         ptr[1] = __alloc_percpu(mibsize, align);
1519         if (!ptr[1])
1520                 goto err1;
1521         return 0;
1522 err1:
1523         free_percpu(ptr[0]);
1524         ptr[0] = NULL;
1525 err0:
1526         return -ENOMEM;
1527 }
1528 EXPORT_SYMBOL_GPL(snmp_mib_init);
1529
1530 void snmp_mib_free(void __percpu *ptr[2])
1531 {
1532         BUG_ON(ptr == NULL);
1533         free_percpu(ptr[0]);
1534         free_percpu(ptr[1]);
1535         ptr[0] = ptr[1] = NULL;
1536 }
1537 EXPORT_SYMBOL_GPL(snmp_mib_free);
1538
1539 #ifdef CONFIG_IP_MULTICAST
1540 static const struct net_protocol igmp_protocol = {
1541         .handler =      igmp_rcv,
1542         .netns_ok =     1,
1543 };
1544 #endif
1545
1546 static const struct net_protocol tcp_protocol = {
1547         .handler =      tcp_v4_rcv,
1548         .err_handler =  tcp_v4_err,
1549         .gso_send_check = tcp_v4_gso_send_check,
1550         .gso_segment =  tcp_tso_segment,
1551         .gro_receive =  tcp4_gro_receive,
1552         .gro_complete = tcp4_gro_complete,
1553         .no_policy =    1,
1554         .netns_ok =     1,
1555 };
1556
1557 static const struct net_protocol udp_protocol = {
1558         .handler =      udp_rcv,
1559         .err_handler =  udp_err,
1560         .gso_send_check = udp4_ufo_send_check,
1561         .gso_segment = udp4_ufo_fragment,
1562         .no_policy =    1,
1563         .netns_ok =     1,
1564 };
1565
1566 static const struct net_protocol icmp_protocol = {
1567         .handler =      icmp_rcv,
1568         .err_handler =  ping_err,
1569         .no_policy =    1,
1570         .netns_ok =     1,
1571 };
1572
1573 static __net_init int ipv4_mib_init_net(struct net *net)
1574 {
1575         if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1576                           sizeof(struct tcp_mib),
1577                           __alignof__(struct tcp_mib)) < 0)
1578                 goto err_tcp_mib;
1579         if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1580                           sizeof(struct ipstats_mib),
1581                           __alignof__(struct ipstats_mib)) < 0)
1582                 goto err_ip_mib;
1583         if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1584                           sizeof(struct linux_mib),
1585                           __alignof__(struct linux_mib)) < 0)
1586                 goto err_net_mib;
1587         if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1588                           sizeof(struct udp_mib),
1589                           __alignof__(struct udp_mib)) < 0)
1590                 goto err_udp_mib;
1591         if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1592                           sizeof(struct udp_mib),
1593                           __alignof__(struct udp_mib)) < 0)
1594                 goto err_udplite_mib;
1595         if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1596                           sizeof(struct icmp_mib),
1597                           __alignof__(struct icmp_mib)) < 0)
1598                 goto err_icmp_mib;
1599         if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
1600                           sizeof(struct icmpmsg_mib),
1601                           __alignof__(struct icmpmsg_mib)) < 0)
1602                 goto err_icmpmsg_mib;
1603
1604         tcp_mib_init(net);
1605         return 0;
1606
1607 err_icmpmsg_mib:
1608         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1609 err_icmp_mib:
1610         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1611 err_udplite_mib:
1612         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1613 err_udp_mib:
1614         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1615 err_net_mib:
1616         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1617 err_ip_mib:
1618         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1619 err_tcp_mib:
1620         return -ENOMEM;
1621 }
1622
1623 static __net_exit void ipv4_mib_exit_net(struct net *net)
1624 {
1625         snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
1626         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1627         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1628         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1629         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1630         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1631         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1632 }
1633
1634 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1635         .init = ipv4_mib_init_net,
1636         .exit = ipv4_mib_exit_net,
1637 };
1638
1639 static int __init init_ipv4_mibs(void)
1640 {
1641         return register_pernet_subsys(&ipv4_mib_ops);
1642 }
1643
1644 static int ipv4_proc_init(void);
1645
1646 /*
1647  *      IP protocol layer initialiser
1648  */
1649
1650 static struct packet_type ip_packet_type __read_mostly = {
1651         .type = cpu_to_be16(ETH_P_IP),
1652         .func = ip_rcv,
1653         .gso_send_check = inet_gso_send_check,
1654         .gso_segment = inet_gso_segment,
1655         .gro_receive = inet_gro_receive,
1656         .gro_complete = inet_gro_complete,
1657 };
1658
1659 static int __init inet_init(void)
1660 {
1661         struct sk_buff *dummy_skb;
1662         struct inet_protosw *q;
1663         struct list_head *r;
1664         int rc = -EINVAL;
1665
1666         BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1667
1668         sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1669         if (!sysctl_local_reserved_ports)
1670                 goto out;
1671
1672         rc = proto_register(&tcp_prot, 1);
1673         if (rc)
1674                 goto out_free_reserved_ports;
1675
1676         rc = proto_register(&udp_prot, 1);
1677         if (rc)
1678                 goto out_unregister_tcp_proto;
1679
1680         rc = proto_register(&raw_prot, 1);
1681         if (rc)
1682                 goto out_unregister_udp_proto;
1683
1684         rc = proto_register(&ping_prot, 1);
1685         if (rc)
1686                 goto out_unregister_raw_proto;
1687
1688         /*
1689          *      Tell SOCKET that we are alive...
1690          */
1691
1692         (void)sock_register(&inet_family_ops);
1693
1694 #ifdef CONFIG_SYSCTL
1695         ip_static_sysctl_init();
1696 #endif
1697
1698         /*
1699          *      Add all the base protocols.
1700          */
1701
1702         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1703                 printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1704         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1705                 printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1706         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1707                 printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1708 #ifdef CONFIG_IP_MULTICAST
1709         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1710                 printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1711 #endif
1712
1713         /* Register the socket-side information for inet_create. */
1714         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1715                 INIT_LIST_HEAD(r);
1716
1717         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1718                 inet_register_protosw(q);
1719
1720         /*
1721          *      Set the ARP module up
1722          */
1723
1724         arp_init();
1725
1726         /*
1727          *      Set the IP module up
1728          */
1729
1730         ip_init();
1731
1732         tcp_v4_init();
1733
1734         /* Setup TCP slab cache for open requests. */
1735         tcp_init();
1736
1737         /* Setup UDP memory threshold */
1738         udp_init();
1739
1740         /* Add UDP-Lite (RFC 3828) */
1741         udplite4_register();
1742
1743         ping_init();
1744
1745         /*
1746          *      Set the ICMP layer up
1747          */
1748
1749         if (icmp_init() < 0)
1750                 panic("Failed to create the ICMP control socket.\n");
1751
1752         /*
1753          *      Initialise the multicast router
1754          */
1755 #if defined(CONFIG_IP_MROUTE)
1756         if (ip_mr_init())
1757                 printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1758 #endif
1759         /*
1760          *      Initialise per-cpu ipv4 mibs
1761          */
1762
1763         if (init_ipv4_mibs())
1764                 printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1765
1766         ipv4_proc_init();
1767
1768         ipfrag_init();
1769
1770         dev_add_pack(&ip_packet_type);
1771
1772         rc = 0;
1773 out:
1774         return rc;
1775 out_unregister_raw_proto:
1776         proto_unregister(&raw_prot);
1777 out_unregister_udp_proto:
1778         proto_unregister(&udp_prot);
1779 out_unregister_tcp_proto:
1780         proto_unregister(&tcp_prot);
1781 out_free_reserved_ports:
1782         kfree(sysctl_local_reserved_ports);
1783         goto out;
1784 }
1785
1786 fs_initcall(inet_init);
1787
1788 /* ------------------------------------------------------------------------ */
1789
1790 #ifdef CONFIG_PROC_FS
1791 static int __init ipv4_proc_init(void)
1792 {
1793         int rc = 0;
1794
1795         if (raw_proc_init())
1796                 goto out_raw;
1797         if (tcp4_proc_init())
1798                 goto out_tcp;
1799         if (udp4_proc_init())
1800                 goto out_udp;
1801         if (ping_proc_init())
1802                 goto out_ping;
1803         if (ip_misc_proc_init())
1804                 goto out_misc;
1805 out:
1806         return rc;
1807 out_misc:
1808         ping_proc_exit();
1809 out_ping:
1810         udp4_proc_exit();
1811 out_udp:
1812         tcp4_proc_exit();
1813 out_tcp:
1814         raw_proc_exit();
1815 out_raw:
1816         rc = -ENOMEM;
1817         goto out;
1818 }
1819
1820 #else /* CONFIG_PROC_FS */
1821 static int __init ipv4_proc_init(void)
1822 {
1823         return 0;
1824 }
1825 #endif /* CONFIG_PROC_FS */
1826
1827 MODULE_ALIAS_NETPROTO(PF_INET);
1828