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         dst_release(sk->sk_rx_dst);
 161         sk_refcnt_debug_dec(sk);
 162 }
 163 EXPORT_SYMBOL(inet_sock_destruct);
 164
 165 /*
 166  *      The routines beyond this point handle the behaviour of an AF_INET
 167  *      socket object. Mostly it punts to the subprotocols of IP to do
 168  *      the work.
 169  */
 170
 171 /*
 172  *      Automatically bind an unbound socket.
 173  */
 174
 175 static int inet_autobind(struct sock *sk)
 176 {
 177         struct inet_sock *inet;
 178         /* We may need to bind the socket. */
 179         lock_sock(sk);
 180         inet = inet_sk(sk);
 181         if (!inet->inet_num) {
 182                 if (sk->sk_prot->get_port(sk, 0)) {
 183                         release_sock(sk);
 184                         return -EAGAIN;
 185                 }
 186                 inet->inet_sport = htons(inet->inet_num);
 187         }
 188         release_sock(sk);
 189         return 0;
 190 }
 191
 192 /*
 193  *      Move a socket into listening state.
 194  */
 195 int inet_listen(struct socket *sock, int backlog)
 196 {
 197         struct sock *sk = sock->sk;
 198         unsigned char old_state;
 199         int err;
 200
 201         lock_sock(sk);
 202
 203         err = -EINVAL;
 204         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
 205                 goto out;
 206
 207         old_state = sk->sk_state;
 208         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 209                 goto out;
 210
 211         /* Really, if the socket is already in listen state
 212          * we can only allow the backlog to be adjusted.
 213          */
 214         if (old_state != TCP_LISTEN) {
 215                 /* Check special setups for testing purpose to enable TFO w/o
 216                  * requiring TCP_FASTOPEN sockopt.
 217                  * Note that only TCP sockets (SOCK_STREAM) will reach here.
 218                  * Also fastopenq may already been allocated because this
 219                  * socket was in TCP_LISTEN state previously but was
 220                  * shutdown() (rather than close()).
 221                  */
 222                 if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) != 0 &&
 223                     inet_csk(sk)->icsk_accept_queue.fastopenq == NULL) {
 224                         if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) != 0)
 225                                 err = fastopen_init_queue(sk, backlog);
 226                         else if ((sysctl_tcp_fastopen &
 227                                   TFO_SERVER_WO_SOCKOPT2) != 0)
 228                                 err = fastopen_init_queue(sk,
 229                                     ((uint)sysctl_tcp_fastopen) >> 16);
 230                         else
 231                                 err = 0;
 232                         if (err)
 233                                 goto out;
 234                 }
 235                 err = inet_csk_listen_start(sk, backlog);
 236                 if (err)
 237                         goto out;
 238         }
 239         sk->sk_max_ack_backlog = backlog;
 240         err = 0;
 241
 242 out:
 243         release_sock(sk);
 244         return err;
 245 }
 246 EXPORT_SYMBOL(inet_listen);
 247
 248 u32 inet_ehash_secret __read_mostly;
 249 EXPORT_SYMBOL(inet_ehash_secret);
 250
 251 /*
 252  * inet_ehash_secret must be set exactly once
 253  */
 254 void build_ehash_secret(void)
 255 {
 256         u32 rnd;
 257
 258         do {
 259                 get_random_bytes(&rnd, sizeof(rnd));
 260         } while (rnd == 0);
 261
 262         cmpxchg(&inet_ehash_secret, 0, rnd);
 263 }
 264 EXPORT_SYMBOL(build_ehash_secret);
 265
 266 /*
 267  *      Create an inet socket.
 268  */
 269
 270 static int inet_create(struct net *net, struct socket *sock, int protocol,
 271                        int kern)
 272 {
 273         struct sock *sk;
 274         struct inet_protosw *answer;
 275         struct inet_sock *inet;
 276         struct proto *answer_prot;
 277         unsigned char answer_flags;
 278         char answer_no_check;
 279         int try_loading_module = 0;
 280         int err;
 281
 282         if (unlikely(!inet_ehash_secret))
 283                 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
 284                         build_ehash_secret();
 285
 286         sock->state = SS_UNCONNECTED;
 287
 288         /* Look for the requested type/protocol pair. */
 289 lookup_protocol:
 290         err = -ESOCKTNOSUPPORT;
 291         rcu_read_lock();
 292         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 293
 294                 err = 0;
 295                 /* Check the non-wild match. */
 296                 if (protocol == answer->protocol) {
 297                         if (protocol != IPPROTO_IP)
 298                                 break;
 299                 } else {
 300                         /* Check for the two wild cases. */
 301                         if (IPPROTO_IP == protocol) {
 302                                 protocol = answer->protocol;
 303                                 break;
 304                         }
 305                         if (IPPROTO_IP == answer->protocol)
 306                                 break;
 307                 }
 308                 err = -EPROTONOSUPPORT;
 309         }
 310
 311         if (unlikely(err)) {
 312                 if (try_loading_module < 2) {
 313                         rcu_read_unlock();
 314                         /*
 315                          * Be more specific, e.g. net-pf-2-proto-132-type-1
 316                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 317                          */
 318                         if (++try_loading_module == 1)
 319                                 request_module("net-pf-%d-proto-%d-type-%d",
 320                                                PF_INET, protocol, sock->type);
 321                         /*
 322                          * Fall back to generic, e.g. net-pf-2-proto-132
 323                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 324                          */
 325                         else
 326                                 request_module("net-pf-%d-proto-%d",
 327                                                PF_INET, protocol);
 328                         goto lookup_protocol;
 329                 } else
 330                         goto out_rcu_unlock;
 331         }
 332
 333         err = -EPERM;
 334         if (sock->type == SOCK_RAW && !kern &&
 335             !ns_capable(net->user_ns, CAP_NET_RAW))
 336                 goto out_rcu_unlock;
 337
 338         sock->ops = answer->ops;
 339         answer_prot = answer->prot;
 340         answer_no_check = answer->no_check;
 341         answer_flags = answer->flags;
 342         rcu_read_unlock();
 343
 344         WARN_ON(answer_prot->slab == NULL);
 345
 346         err = -ENOBUFS;
 347         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
 348         if (sk == NULL)
 349                 goto out;
 350
 351         err = 0;
 352         sk->sk_no_check = answer_no_check;
 353         if (INET_PROTOSW_REUSE & answer_flags)
 354                 sk->sk_reuse = SK_CAN_REUSE;
 355
 356         inet = inet_sk(sk);
 357         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 358
 359         inet->nodefrag = 0;
 360
 361         if (SOCK_RAW == sock->type) {
 362                 inet->inet_num = protocol;
 363                 if (IPPROTO_RAW == protocol)
 364                         inet->hdrincl = 1;
 365         }
 366
 367         if (ipv4_config.no_pmtu_disc)
 368                 inet->pmtudisc = IP_PMTUDISC_DONT;
 369         else
 370                 inet->pmtudisc = IP_PMTUDISC_WANT;
 371
 372         inet->inet_id = 0;
 373
 374         sock_init_data(sock, sk);
 375
 376         sk->sk_destruct    = inet_sock_destruct;
 377         sk->sk_protocol    = protocol;
 378         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 379
 380         inet->uc_ttl    = -1;
 381         inet->mc_loop   = 1;
 382         inet->mc_ttl    = 1;
 383         inet->mc_all    = 1;
 384         inet->mc_index  = 0;
 385         inet->mc_list   = NULL;
 386         inet->rcv_tos   = 0;
 387
 388         sk_refcnt_debug_inc(sk);
 389
 390         if (inet->inet_num) {
 391                 /* It assumes that any protocol which allows
 392                  * the user to assign a number at socket
 393                  * creation time automatically
 394                  * shares.
 395                  */
 396                 inet->inet_sport = htons(inet->inet_num);
 397                 /* Add to protocol hash chains. */
 398                 sk->sk_prot->hash(sk);
 399         }
 400
 401         if (sk->sk_prot->init) {
 402                 err = sk->sk_prot->init(sk);
 403                 if (err)
 404                         sk_common_release(sk);
 405         }
 406 out:
 407         return err;
 408 out_rcu_unlock:
 409         rcu_read_unlock();
 410         goto out;
 411 }
 412
 413
 414 /*
 415  *      The peer socket should always be NULL (or else). When we call this
 416  *      function we are destroying the object and from then on nobody
 417  *      should refer to it.
 418  */
 419 int inet_release(struct socket *sock)
 420 {
 421         struct sock *sk = sock->sk;
 422
 423         if (sk) {
 424                 long timeout;
 425
 426                 sock_rps_reset_flow(sk);
 427
 428                 /* Applications forget to leave groups before exiting */
 429                 ip_mc_drop_socket(sk);
 430
 431                 /* If linger is set, we don't return until the close
 432                  * is complete.  Otherwise we return immediately. The
 433                  * actually closing is done the same either way.
 434                  *
 435                  * If the close is due to the process exiting, we never
 436                  * linger..
 437                  */
 438                 timeout = 0;
 439                 if (sock_flag(sk, SOCK_LINGER) &&
 440                     !(current->flags & PF_EXITING))
 441                         timeout = sk->sk_lingertime;
 442                 sock->sk = NULL;
 443                 sk->sk_prot->close(sk, timeout);
 444         }
 445         return 0;
 446 }
 447 EXPORT_SYMBOL(inet_release);
 448
 449 /* It is off by default, see below. */
 450 int sysctl_ip_nonlocal_bind __read_mostly;
 451 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
 452
 453 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 454 {
 455         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 456         struct sock *sk = sock->sk;
 457         struct inet_sock *inet = inet_sk(sk);
 458         struct net *net = sock_net(sk);
 459         unsigned short snum;
 460         int chk_addr_ret;
 461         int err;
 462
 463         /* If the socket has its own bind function then use it. (RAW) */
 464         if (sk->sk_prot->bind) {
 465                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
 466                 goto out;
 467         }
 468         err = -EINVAL;
 469         if (addr_len < sizeof(struct sockaddr_in))
 470                 goto out;
 471
 472         if (addr->sin_family != AF_INET) {
 473                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
 474                  * only if s_addr is INADDR_ANY.
 475                  */
 476                 err = -EAFNOSUPPORT;
 477                 if (addr->sin_family != AF_UNSPEC ||
 478                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
 479                         goto out;
 480         }
 481
 482         chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
 483
 484         /* Not specified by any standard per-se, however it breaks too
 485          * many applications when removed.  It is unfortunate since
 486          * allowing applications to make a non-local bind solves
 487          * several problems with systems using dynamic addressing.
 488          * (ie. your servers still start up even if your ISDN link
 489          *  is temporarily down)
 490          */
 491         err = -EADDRNOTAVAIL;
 492         if (!sysctl_ip_nonlocal_bind &&
 493             !(inet->freebind || inet->transparent) &&
 494             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
 495             chk_addr_ret != RTN_LOCAL &&
 496             chk_addr_ret != RTN_MULTICAST &&
 497             chk_addr_ret != RTN_BROADCAST)
 498                 goto out;
 499
 500         snum = ntohs(addr->sin_port);
 501         err = -EACCES;
 502         if (snum && snum < PROT_SOCK &&
 503             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
 504                 goto out;
 505
 506         /*      We keep a pair of addresses. rcv_saddr is the one
 507          *      used by hash lookups, and saddr is used for transmit.
 508          *
 509          *      In the BSD API these are the same except where it
 510          *      would be illegal to use them (multicast/broadcast) in
 511          *      which case the sending device address is used.
 512          */
 513         lock_sock(sk);
 514
 515         /* Check these errors (active socket, double bind). */
 516         err = -EINVAL;
 517         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
 518                 goto out_release_sock;
 519
 520         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
 521         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 522                 inet->inet_saddr = 0;  /* Use device */
 523
 524         /* Make sure we are allowed to bind here. */
 525         if (sk->sk_prot->get_port(sk, snum)) {
 526                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
 527                 err = -EADDRINUSE;
 528                 goto out_release_sock;
 529         }
 530
 531         if (inet->inet_rcv_saddr)
 532                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 533         if (snum)
 534                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 535         inet->inet_sport = htons(inet->inet_num);
 536         inet->inet_daddr = 0;
 537         inet->inet_dport = 0;
 538         sk_dst_reset(sk);
 539         err = 0;
 540 out_release_sock:
 541         release_sock(sk);
 542 out:
 543         return err;
 544 }
 545 EXPORT_SYMBOL(inet_bind);
 546
 547 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 548                        int addr_len, int flags)
 549 {
 550         struct sock *sk = sock->sk;
 551
 552         if (addr_len < sizeof(uaddr->sa_family))
 553                 return -EINVAL;
 554         if (uaddr->sa_family == AF_UNSPEC)
 555                 return sk->sk_prot->disconnect(sk, flags);
 556
 557         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
 558                 return -EAGAIN;
 559         return sk->sk_prot->connect(sk, uaddr, addr_len);
 560 }
 561 EXPORT_SYMBOL(inet_dgram_connect);
 562
 563 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
 564 {
 565         DEFINE_WAIT(wait);
 566
 567         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 568         sk->sk_write_pending += writebias;
 569
 570         /* Basic assumption: if someone sets sk->sk_err, he _must_
 571          * change state of the socket from TCP_SYN_*.
 572          * Connect() does not allow to get error notifications
 573          * without closing the socket.
 574          */
 575         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 576                 release_sock(sk);
 577                 timeo = schedule_timeout(timeo);
 578                 lock_sock(sk);
 579                 if (signal_pending(current) || !timeo)
 580                         break;
 581                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 582         }
 583         finish_wait(sk_sleep(sk), &wait);
 584         sk->sk_write_pending -= writebias;
 585         return timeo;
 586 }
 587
 588 /*
 589  *      Connect to a remote host. There is regrettably still a little
 590  *      TCP 'magic' in here.
 591  */
 592 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 593                           int addr_len, int flags)
 594 {
 595         struct sock *sk = sock->sk;
 596         int err;
 597         long timeo;
 598
 599         if (addr_len < sizeof(uaddr->sa_family))
 600                 return -EINVAL;
 601
 602         if (uaddr->sa_family == AF_UNSPEC) {
 603                 err = sk->sk_prot->disconnect(sk, flags);
 604                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 605                 goto out;
 606         }
 607
 608         switch (sock->state) {
 609         default:
 610                 err = -EINVAL;
 611                 goto out;
 612         case SS_CONNECTED:
 613                 err = -EISCONN;
 614                 goto out;
 615         case SS_CONNECTING:
 616                 err = -EALREADY;
 617                 /* Fall out of switch with err, set for this state */
 618                 break;
 619         case SS_UNCONNECTED:
 620                 err = -EISCONN;
 621                 if (sk->sk_state != TCP_CLOSE)
 622                         goto out;
 623
 624                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
 625                 if (err < 0)
 626                         goto out;
 627
 628                 sock->state = SS_CONNECTING;
 629
 630                 /* Just entered SS_CONNECTING state; the only
 631                  * difference is that return value in non-blocking
 632                  * case is EINPROGRESS, rather than EALREADY.
 633                  */
 634                 err = -EINPROGRESS;
 635                 break;
 636         }
 637
 638         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 639
 640         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 641                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
 642                                 tcp_sk(sk)->fastopen_req &&
 643                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
 644
 645                 /* Error code is set above */
 646                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
 647                         goto out;
 648
 649                 err = sock_intr_errno(timeo);
 650                 if (signal_pending(current))
 651                         goto out;
 652         }
 653
 654         /* Connection was closed by RST, timeout, ICMP error
 655          * or another process disconnected us.
 656          */
 657         if (sk->sk_state == TCP_CLOSE)
 658                 goto sock_error;
 659
 660         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 661          * and error was received after socket entered established state.
 662          * Hence, it is handled normally after connect() return successfully.
 663          */
 664
 665         sock->state = SS_CONNECTED;
 666         err = 0;
 667 out:
 668         return err;
 669
 670 sock_error:
 671         err = sock_error(sk) ? : -ECONNABORTED;
 672         sock->state = SS_UNCONNECTED;
 673         if (sk->sk_prot->disconnect(sk, flags))
 674                 sock->state = SS_DISCONNECTING;
 675         goto out;
 676 }
 677 EXPORT_SYMBOL(__inet_stream_connect);
 678
 679 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 680                         int addr_len, int flags)
 681 {
 682         int err;
 683
 684         lock_sock(sock->sk);
 685         err = __inet_stream_connect(sock, uaddr, addr_len, flags);
 686         release_sock(sock->sk);
 687         return err;
 688 }
 689 EXPORT_SYMBOL(inet_stream_connect);
 690
 691 /*
 692  *      Accept a pending connection. The TCP layer now gives BSD semantics.
 693  */
 694
 695 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
 696 {
 697         struct sock *sk1 = sock->sk;
 698         int err = -EINVAL;
 699         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
 700
 701         if (!sk2)
 702                 goto do_err;
 703
 704         lock_sock(sk2);
 705
 706         sock_rps_record_flow(sk2);
 707         WARN_ON(!((1 << sk2->sk_state) &
 708                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
 709                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 710
 711         sock_graft(sk2, newsock);
 712
 713         newsock->state = SS_CONNECTED;
 714         err = 0;
 715         release_sock(sk2);
 716 do_err:
 717         return err;
 718 }
 719 EXPORT_SYMBOL(inet_accept);
 720
 721
 722 /*
 723  *      This does both peername and sockname.
 724  */
 725 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 726                         int *uaddr_len, int peer)
 727 {
 728         struct sock *sk         = sock->sk;
 729         struct inet_sock *inet  = inet_sk(sk);
 730         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 731
 732         sin->sin_family = AF_INET;
 733         if (peer) {
 734                 if (!inet->inet_dport ||
 735                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 736                      peer == 1))
 737                         return -ENOTCONN;
 738                 sin->sin_port = inet->inet_dport;
 739                 sin->sin_addr.s_addr = inet->inet_daddr;
 740         } else {
 741                 __be32 addr = inet->inet_rcv_saddr;
 742                 if (!addr)
 743                         addr = inet->inet_saddr;
 744                 sin->sin_port = inet->inet_sport;
 745                 sin->sin_addr.s_addr = addr;
 746         }
 747         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 748         *uaddr_len = sizeof(*sin);
 749         return 0;
 750 }
 751 EXPORT_SYMBOL(inet_getname);
 752
 753 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 754                  size_t size)
 755 {
 756         struct sock *sk = sock->sk;
 757
 758         sock_rps_record_flow(sk);
 759
 760         /* We may need to bind the socket. */
 761         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 762             inet_autobind(sk))
 763                 return -EAGAIN;
 764
 765         return sk->sk_prot->sendmsg(iocb, sk, msg, size);
 766 }
 767 EXPORT_SYMBOL(inet_sendmsg);
 768
 769 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 770                       size_t size, int flags)
 771 {
 772         struct sock *sk = sock->sk;
 773
 774         sock_rps_record_flow(sk);
 775
 776         /* We may need to bind the socket. */
 777         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 778             inet_autobind(sk))
 779                 return -EAGAIN;
 780
 781         if (sk->sk_prot->sendpage)
 782                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
 783         return sock_no_sendpage(sock, page, offset, size, flags);
 784 }
 785 EXPORT_SYMBOL(inet_sendpage);
 786
 787 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 788                  size_t size, int flags)
 789 {
 790         struct sock *sk = sock->sk;
 791         int addr_len = 0;
 792         int err;
 793
 794         sock_rps_record_flow(sk);
 795
 796         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
 797                                    flags & ~MSG_DONTWAIT, &addr_len);
 798         if (err >= 0)
 799                 msg->msg_namelen = addr_len;
 800         return err;
 801 }
 802 EXPORT_SYMBOL(inet_recvmsg);
 803
 804 int inet_shutdown(struct socket *sock, int how)
 805 {
 806         struct sock *sk = sock->sk;
 807         int err = 0;
 808
 809         /* This should really check to make sure
 810          * the socket is a TCP socket. (WHY AC...)
 811          */
 812         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 813                        1->2 bit 2 snds.
 814                        2->3 */
 815         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 816                 return -EINVAL;
 817
 818         lock_sock(sk);
 819         if (sock->state == SS_CONNECTING) {
 820                 if ((1 << sk->sk_state) &
 821                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 822                         sock->state = SS_DISCONNECTING;
 823                 else
 824                         sock->state = SS_CONNECTED;
 825         }
 826
 827         switch (sk->sk_state) {
 828         case TCP_CLOSE:
 829                 err = -ENOTCONN;
 830                 /* Hack to wake up other listeners, who can poll for
 831                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
 832         default:
 833                 sk->sk_shutdown |= how;
 834                 if (sk->sk_prot->shutdown)
 835                         sk->sk_prot->shutdown(sk, how);
 836                 break;
 837
 838         /* Remaining two branches are temporary solution for missing
 839          * close() in multithreaded environment. It is _not_ a good idea,
 840          * but we have no choice until close() is repaired at VFS level.
 841          */
 842         case TCP_LISTEN:
 843                 if (!(how & RCV_SHUTDOWN))
 844                         break;
 845                 /* Fall through */
 846         case TCP_SYN_SENT:
 847                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 848                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 849                 break;
 850         }
 851
 852         /* Wake up anyone sleeping in poll. */
 853         sk->sk_state_change(sk);
 854         release_sock(sk);
 855         return err;
 856 }
 857 EXPORT_SYMBOL(inet_shutdown);
 858
 859 /*
 860  *      ioctl() calls you can issue on an INET socket. Most of these are
 861  *      device configuration and stuff and very rarely used. Some ioctls
 862  *      pass on to the socket itself.
 863  *
 864  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 865  *      loads the devconfigure module does its configuring and unloads it.
 866  *      There's a good 20K of config code hanging around the kernel.
 867  */
 868
 869 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 870 {
 871         struct sock *sk = sock->sk;
 872         int err = 0;
 873         struct net *net = sock_net(sk);
 874
 875         switch (cmd) {
 876         case SIOCGSTAMP:
 877                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
 878                 break;
 879         case SIOCGSTAMPNS:
 880                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
 881                 break;
 882         case SIOCADDRT:
 883         case SIOCDELRT:
 884         case SIOCRTMSG:
 885                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
 886                 break;
 887         case SIOCDARP:
 888         case SIOCGARP:
 889         case SIOCSARP:
 890                 err = arp_ioctl(net, cmd, (void __user *)arg);
 891                 break;
 892         case SIOCGIFADDR:
 893         case SIOCSIFADDR:
 894         case SIOCGIFBRDADDR:
 895         case SIOCSIFBRDADDR:
 896         case SIOCGIFNETMASK:
 897         case SIOCSIFNETMASK:
 898         case SIOCGIFDSTADDR:
 899         case SIOCSIFDSTADDR:
 900         case SIOCSIFPFLAGS:
 901         case SIOCGIFPFLAGS:
 902         case SIOCSIFFLAGS:
 903                 err = devinet_ioctl(net, cmd, (void __user *)arg);
 904                 break;
 905         default:
 906                 if (sk->sk_prot->ioctl)
 907                         err = sk->sk_prot->ioctl(sk, cmd, arg);
 908                 else
 909                         err = -ENOIOCTLCMD;
 910                 break;
 911         }
 912         return err;
 913 }
 914 EXPORT_SYMBOL(inet_ioctl);
 915
 916 #ifdef CONFIG_COMPAT
 917 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 918 {
 919         struct sock *sk = sock->sk;
 920         int err = -ENOIOCTLCMD;
 921
 922         if (sk->sk_prot->compat_ioctl)
 923                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
 924
 925         return err;
 926 }
 927 #endif
 928
 929 const struct proto_ops inet_stream_ops = {
 930         .family            = PF_INET,
 931         .owner             = THIS_MODULE,
 932         .release           = inet_release,
 933         .bind              = inet_bind,
 934         .connect           = inet_stream_connect,
 935         .socketpair        = sock_no_socketpair,
 936         .accept            = inet_accept,
 937         .getname           = inet_getname,
 938         .poll              = tcp_poll,
 939         .ioctl             = inet_ioctl,
 940         .listen            = inet_listen,
 941         .shutdown          = inet_shutdown,
 942         .setsockopt        = sock_common_setsockopt,
 943         .getsockopt        = sock_common_getsockopt,
 944         .sendmsg           = inet_sendmsg,
 945         .recvmsg           = inet_recvmsg,
 946         .mmap              = sock_no_mmap,
 947         .sendpage          = inet_sendpage,
 948         .splice_read       = tcp_splice_read,
 949 #ifdef CONFIG_COMPAT
 950         .compat_setsockopt = compat_sock_common_setsockopt,
 951         .compat_getsockopt = compat_sock_common_getsockopt,
 952         .compat_ioctl      = inet_compat_ioctl,
 953 #endif
 954 };
 955 EXPORT_SYMBOL(inet_stream_ops);
 956
 957 const struct proto_ops inet_dgram_ops = {
 958         .family            = PF_INET,
 959         .owner             = THIS_MODULE,
 960         .release           = inet_release,
 961         .bind              = inet_bind,
 962         .connect           = inet_dgram_connect,
 963         .socketpair        = sock_no_socketpair,
 964         .accept            = sock_no_accept,
 965         .getname           = inet_getname,
 966         .poll              = udp_poll,
 967         .ioctl             = inet_ioctl,
 968         .listen            = sock_no_listen,
 969         .shutdown          = inet_shutdown,
 970         .setsockopt        = sock_common_setsockopt,
 971         .getsockopt        = sock_common_getsockopt,
 972         .sendmsg           = inet_sendmsg,
 973         .recvmsg           = inet_recvmsg,
 974         .mmap              = sock_no_mmap,
 975         .sendpage          = inet_sendpage,
 976 #ifdef CONFIG_COMPAT
 977         .compat_setsockopt = compat_sock_common_setsockopt,
 978         .compat_getsockopt = compat_sock_common_getsockopt,
 979         .compat_ioctl      = inet_compat_ioctl,
 980 #endif
 981 };
 982 EXPORT_SYMBOL(inet_dgram_ops);
 983
 984 /*
 985  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
 986  * udp_poll
 987  */
 988 static const struct proto_ops inet_sockraw_ops = {
 989         .family            = PF_INET,
 990         .owner             = THIS_MODULE,
 991         .release           = inet_release,
 992         .bind              = inet_bind,
 993         .connect           = inet_dgram_connect,
 994         .socketpair        = sock_no_socketpair,
 995         .accept            = sock_no_accept,
 996         .getname           = inet_getname,
 997         .poll              = datagram_poll,
 998         .ioctl             = inet_ioctl,
 999         .listen            = sock_no_listen,
1000         .shutdown          = inet_shutdown,
1001         .setsockopt        = sock_common_setsockopt,
1002         .getsockopt        = sock_common_getsockopt,
1003         .sendmsg           = inet_sendmsg,
1004         .recvmsg           = inet_recvmsg,
1005         .mmap              = sock_no_mmap,
1006         .sendpage          = inet_sendpage,
1007 #ifdef CONFIG_COMPAT
1008         .compat_setsockopt = compat_sock_common_setsockopt,
1009         .compat_getsockopt = compat_sock_common_getsockopt,
1010         .compat_ioctl      = inet_compat_ioctl,
1011 #endif
1012 };
1013
1014 static const struct net_proto_family inet_family_ops = {
1015         .family = PF_INET,
1016         .create = inet_create,
1017         .owner  = THIS_MODULE,
1018 };
1019
1020 /* Upon startup we insert all the elements in inetsw_array[] into
1021  * the linked list inetsw.
1022  */
1023 static struct inet_protosw inetsw_array[] =
1024 {
1025         {
1026                 .type =       SOCK_STREAM,
1027                 .protocol =   IPPROTO_TCP,
1028                 .prot =       &tcp_prot,
1029                 .ops =        &inet_stream_ops,
1030                 .no_check =   0,
1031                 .flags =      INET_PROTOSW_PERMANENT |
1032                               INET_PROTOSW_ICSK,
1033         },
1034
1035         {
1036                 .type =       SOCK_DGRAM,
1037                 .protocol =   IPPROTO_UDP,
1038                 .prot =       &udp_prot,
1039                 .ops =        &inet_dgram_ops,
1040                 .no_check =   UDP_CSUM_DEFAULT,
1041                 .flags =      INET_PROTOSW_PERMANENT,
1042        },
1043
1044        {
1045                 .type =       SOCK_DGRAM,
1046                 .protocol =   IPPROTO_ICMP,
1047                 .prot =       &ping_prot,
1048                 .ops =        &inet_dgram_ops,
1049                 .no_check =   UDP_CSUM_DEFAULT,
1050                 .flags =      INET_PROTOSW_REUSE,
1051        },
1052
1053        {
1054                .type =       SOCK_RAW,
1055                .protocol =   IPPROTO_IP,        /* wild card */
1056                .prot =       &raw_prot,
1057                .ops =        &inet_sockraw_ops,
1058                .no_check =   UDP_CSUM_DEFAULT,
1059                .flags =      INET_PROTOSW_REUSE,
1060        }
1061 };
1062
1063 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1064
1065 void inet_register_protosw(struct inet_protosw *p)
1066 {
1067         struct list_head *lh;
1068         struct inet_protosw *answer;
1069         int protocol = p->protocol;
1070         struct list_head *last_perm;
1071
1072         spin_lock_bh(&inetsw_lock);
1073
1074         if (p->type >= SOCK_MAX)
1075                 goto out_illegal;
1076
1077         /* If we are trying to override a permanent protocol, bail. */
1078         answer = NULL;
1079         last_perm = &inetsw[p->type];
1080         list_for_each(lh, &inetsw[p->type]) {
1081                 answer = list_entry(lh, struct inet_protosw, list);
1082
1083                 /* Check only the non-wild match. */
1084                 if (INET_PROTOSW_PERMANENT & answer->flags) {
1085                         if (protocol == answer->protocol)
1086                                 break;
1087                         last_perm = lh;
1088                 }
1089
1090                 answer = NULL;
1091         }
1092         if (answer)
1093                 goto out_permanent;
1094
1095         /* Add the new entry after the last permanent entry if any, so that
1096          * the new entry does not override a permanent entry when matched with
1097          * a wild-card protocol. But it is allowed to override any existing
1098          * non-permanent entry.  This means that when we remove this entry, the
1099          * system automatically returns to the old behavior.
1100          */
1101         list_add_rcu(&p->list, last_perm);
1102 out:
1103         spin_unlock_bh(&inetsw_lock);
1104
1105         return;
1106
1107 out_permanent:
1108         pr_err("Attempt to override permanent protocol %d\n", protocol);
1109         goto out;
1110
1111 out_illegal:
1112         pr_err("Ignoring attempt to register invalid socket type %d\n",
1113                p->type);
1114         goto out;
1115 }
1116 EXPORT_SYMBOL(inet_register_protosw);
1117
1118 void inet_unregister_protosw(struct inet_protosw *p)
1119 {
1120         if (INET_PROTOSW_PERMANENT & p->flags) {
1121                 pr_err("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                 pr_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 net_offload *ops;
1239         const struct iphdr *iph;
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;
1259         err = -EPROTONOSUPPORT;
1260
1261         rcu_read_lock();
1262         ops = rcu_dereference(inet_offloads[proto]);
1263         if (likely(ops && ops->callbacks.gso_send_check))
1264                 err = ops->callbacks.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,
1272         netdev_features_t features)
1273 {
1274         struct sk_buff *segs = ERR_PTR(-EINVAL);
1275         const struct net_offload *ops;
1276         struct iphdr *iph;
1277         int proto;
1278         int ihl;
1279         int id;
1280         unsigned int offset = 0;
1281
1282         if (!(features & NETIF_F_V4_CSUM))
1283                 features &= ~NETIF_F_SG;
1284
1285         if (unlikely(skb_shinfo(skb)->gso_type &
1286                      ~(SKB_GSO_TCPV4 |
1287                        SKB_GSO_UDP |
1288                        SKB_GSO_DODGY |
1289                        SKB_GSO_TCP_ECN |
1290                        SKB_GSO_GRE |
1291                        0)))
1292                 goto out;
1293
1294         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1295                 goto out;
1296
1297         iph = ip_hdr(skb);
1298         ihl = iph->ihl * 4;
1299         if (ihl < sizeof(*iph))
1300                 goto out;
1301
1302         if (unlikely(!pskb_may_pull(skb, ihl)))
1303                 goto out;
1304
1305         __skb_pull(skb, ihl);
1306         skb_reset_transport_header(skb);
1307         iph = ip_hdr(skb);
1308         id = ntohs(iph->id);
1309         proto = iph->protocol;
1310         segs = ERR_PTR(-EPROTONOSUPPORT);
1311
1312         rcu_read_lock();
1313         ops = rcu_dereference(inet_offloads[proto]);
1314         if (likely(ops && ops->callbacks.gso_segment))
1315                 segs = ops->callbacks.gso_segment(skb, features);
1316         rcu_read_unlock();
1317
1318         if (IS_ERR_OR_NULL(segs))
1319                 goto out;
1320
1321         skb = segs;
1322         do {
1323                 iph = ip_hdr(skb);
1324                 if (proto == IPPROTO_UDP) {
1325                         iph->id = htons(id);
1326                         iph->frag_off = htons(offset >> 3);
1327                         if (skb->next != NULL)
1328                                 iph->frag_off |= htons(IP_MF);
1329                         offset += (skb->len - skb->mac_len - iph->ihl * 4);
1330                 } else
1331                         iph->id = htons(id++);
1332                 iph->tot_len = htons(skb->len - skb->mac_len);
1333                 iph->check = 0;
1334                 iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1335         } while ((skb = skb->next));
1336
1337 out:
1338         return segs;
1339 }
1340
1341 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1342                                          struct sk_buff *skb)
1343 {
1344         const struct net_offload *ops;
1345         struct sk_buff **pp = NULL;
1346         struct sk_buff *p;
1347         const struct iphdr *iph;
1348         unsigned int hlen;
1349         unsigned int off;
1350         unsigned int id;
1351         int flush = 1;
1352         int proto;
1353
1354         off = skb_gro_offset(skb);
1355         hlen = off + sizeof(*iph);
1356         iph = skb_gro_header_fast(skb, off);
1357         if (skb_gro_header_hard(skb, hlen)) {
1358                 iph = skb_gro_header_slow(skb, hlen, off);
1359                 if (unlikely(!iph))
1360                         goto out;
1361         }
1362
1363         proto = iph->protocol;
1364
1365         rcu_read_lock();
1366         ops = rcu_dereference(inet_offloads[proto]);
1367         if (!ops || !ops->callbacks.gro_receive)
1368                 goto out_unlock;
1369
1370         if (*(u8 *)iph != 0x45)
1371                 goto out_unlock;
1372
1373         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1374                 goto out_unlock;
1375
1376         id = ntohl(*(__be32 *)&iph->id);
1377         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1378         id >>= 16;
1379
1380         for (p = *head; p; p = p->next) {
1381                 struct iphdr *iph2;
1382
1383                 if (!NAPI_GRO_CB(p)->same_flow)
1384                         continue;
1385
1386                 iph2 = ip_hdr(p);
1387
1388                 if ((iph->protocol ^ iph2->protocol) |
1389                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1390                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1391                         NAPI_GRO_CB(p)->same_flow = 0;
1392                         continue;
1393                 }
1394
1395                 /* All fields must match except length and checksum. */
1396                 NAPI_GRO_CB(p)->flush |=
1397                         (iph->ttl ^ iph2->ttl) |
1398                         (iph->tos ^ iph2->tos) |
1399                         ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1400
1401                 NAPI_GRO_CB(p)->flush |= flush;
1402         }
1403
1404         NAPI_GRO_CB(skb)->flush |= flush;
1405         skb_gro_pull(skb, sizeof(*iph));
1406         skb_set_transport_header(skb, skb_gro_offset(skb));
1407
1408         pp = ops->callbacks.gro_receive(head, skb);
1409
1410 out_unlock:
1411         rcu_read_unlock();
1412
1413 out:
1414         NAPI_GRO_CB(skb)->flush |= flush;
1415
1416         return pp;
1417 }
1418
1419 static int inet_gro_complete(struct sk_buff *skb)
1420 {
1421         __be16 newlen = htons(skb->len - skb_network_offset(skb));
1422         struct iphdr *iph = ip_hdr(skb);
1423         const struct net_offload *ops;
1424         int proto = iph->protocol;
1425         int err = -ENOSYS;
1426
1427         csum_replace2(&iph->check, iph->tot_len, newlen);
1428         iph->tot_len = newlen;
1429
1430         rcu_read_lock();
1431         ops = rcu_dereference(inet_offloads[proto]);
1432         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1433                 goto out_unlock;
1434
1435         err = ops->callbacks.gro_complete(skb);
1436
1437 out_unlock:
1438         rcu_read_unlock();
1439
1440         return err;
1441 }
1442
1443 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1444                          unsigned short type, unsigned char protocol,
1445                          struct net *net)
1446 {
1447         struct socket *sock;
1448         int rc = sock_create_kern(family, type, protocol, &sock);
1449
1450         if (rc == 0) {
1451                 *sk = sock->sk;
1452                 (*sk)->sk_allocation = GFP_ATOMIC;
1453                 /*
1454                  * Unhash it so that IP input processing does not even see it,
1455                  * we do not wish this socket to see incoming packets.
1456                  */
1457                 (*sk)->sk_prot->unhash(*sk);
1458
1459                 sk_change_net(*sk, net);
1460         }
1461         return rc;
1462 }
1463 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1464
1465 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1466 {
1467         unsigned long res = 0;
1468         int i, j;
1469
1470         for_each_possible_cpu(i) {
1471                 for (j = 0; j < SNMP_ARRAY_SZ; j++)
1472                         res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1473         }
1474         return res;
1475 }
1476 EXPORT_SYMBOL_GPL(snmp_fold_field);
1477
1478 #if BITS_PER_LONG==32
1479
1480 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1481 {
1482         u64 res = 0;
1483         int cpu;
1484
1485         for_each_possible_cpu(cpu) {
1486                 void *bhptr;
1487                 struct u64_stats_sync *syncp;
1488                 u64 v;
1489                 unsigned int start;
1490
1491                 bhptr = per_cpu_ptr(mib[0], cpu);
1492                 syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1493                 do {
1494                         start = u64_stats_fetch_begin_bh(syncp);
1495                         v = *(((u64 *) bhptr) + offt);
1496                 } while (u64_stats_fetch_retry_bh(syncp, start));
1497
1498                 res += v;
1499         }
1500         return res;
1501 }
1502 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1503 #endif
1504
1505 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1506 {
1507         BUG_ON(ptr == NULL);
1508         ptr[0] = __alloc_percpu(mibsize, align);
1509         if (!ptr[0])
1510                 return -ENOMEM;
1511 #if SNMP_ARRAY_SZ == 2
1512         ptr[1] = __alloc_percpu(mibsize, align);
1513         if (!ptr[1]) {
1514                 free_percpu(ptr[0]);
1515                 ptr[0] = NULL;
1516                 return -ENOMEM;
1517         }
1518 #endif
1519         return 0;
1520 }
1521 EXPORT_SYMBOL_GPL(snmp_mib_init);
1522
1523 void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
1524 {
1525         int i;
1526
1527         BUG_ON(ptr == NULL);
1528         for (i = 0; i < SNMP_ARRAY_SZ; i++) {
1529                 free_percpu(ptr[i]);
1530                 ptr[i] = NULL;
1531         }
1532 }
1533 EXPORT_SYMBOL_GPL(snmp_mib_free);
1534
1535 #ifdef CONFIG_IP_MULTICAST
1536 static const struct net_protocol igmp_protocol = {
1537         .handler =      igmp_rcv,
1538         .netns_ok =     1,
1539 };
1540 #endif
1541
1542 static const struct net_protocol tcp_protocol = {
1543         .early_demux    =       tcp_v4_early_demux,
1544         .handler        =       tcp_v4_rcv,
1545         .err_handler    =       tcp_v4_err,
1546         .no_policy      =       1,
1547         .netns_ok       =       1,
1548 };
1549
1550 static const struct net_offload tcp_offload = {
1551         .callbacks = {
1552                 .gso_send_check =       tcp_v4_gso_send_check,
1553                 .gso_segment    =       tcp_tso_segment,
1554                 .gro_receive    =       tcp4_gro_receive,
1555                 .gro_complete   =       tcp4_gro_complete,
1556         },
1557 };
1558
1559 static const struct net_protocol udp_protocol = {
1560         .handler =      udp_rcv,
1561         .err_handler =  udp_err,
1562         .no_policy =    1,
1563         .netns_ok =     1,
1564 };
1565
1566 static const struct net_offload udp_offload = {
1567         .callbacks = {
1568                 .gso_send_check = udp4_ufo_send_check,
1569                 .gso_segment = udp4_ufo_fragment,
1570         },
1571 };
1572
1573 static const struct net_protocol icmp_protocol = {
1574         .handler =      icmp_rcv,
1575         .err_handler =  ping_err,
1576         .no_policy =    1,
1577         .netns_ok =     1,
1578 };
1579
1580 static __net_init int ipv4_mib_init_net(struct net *net)
1581 {
1582         if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1583                           sizeof(struct tcp_mib),
1584                           __alignof__(struct tcp_mib)) < 0)
1585                 goto err_tcp_mib;
1586         if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1587                           sizeof(struct ipstats_mib),
1588                           __alignof__(struct ipstats_mib)) < 0)
1589                 goto err_ip_mib;
1590         if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1591                           sizeof(struct linux_mib),
1592                           __alignof__(struct linux_mib)) < 0)
1593                 goto err_net_mib;
1594         if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1595                           sizeof(struct udp_mib),
1596                           __alignof__(struct udp_mib)) < 0)
1597                 goto err_udp_mib;
1598         if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1599                           sizeof(struct udp_mib),
1600                           __alignof__(struct udp_mib)) < 0)
1601                 goto err_udplite_mib;
1602         if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1603                           sizeof(struct icmp_mib),
1604                           __alignof__(struct icmp_mib)) < 0)
1605                 goto err_icmp_mib;
1606         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1607                                               GFP_KERNEL);
1608         if (!net->mib.icmpmsg_statistics)
1609                 goto err_icmpmsg_mib;
1610
1611         tcp_mib_init(net);
1612         return 0;
1613
1614 err_icmpmsg_mib:
1615         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1616 err_icmp_mib:
1617         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1618 err_udplite_mib:
1619         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1620 err_udp_mib:
1621         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1622 err_net_mib:
1623         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1624 err_ip_mib:
1625         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1626 err_tcp_mib:
1627         return -ENOMEM;
1628 }
1629
1630 static __net_exit void ipv4_mib_exit_net(struct net *net)
1631 {
1632         kfree(net->mib.icmpmsg_statistics);
1633         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1634         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1635         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1636         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1637         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1638         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1639 }
1640
1641 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1642         .init = ipv4_mib_init_net,
1643         .exit = ipv4_mib_exit_net,
1644 };
1645
1646 static int __init init_ipv4_mibs(void)
1647 {
1648         return register_pernet_subsys(&ipv4_mib_ops);
1649 }
1650
1651 static int ipv4_proc_init(void);
1652
1653 /*
1654  *      IP protocol layer initialiser
1655  */
1656
1657 static struct packet_offload ip_packet_offload __read_mostly = {
1658         .type = cpu_to_be16(ETH_P_IP),
1659         .callbacks = {
1660                 .gso_send_check = inet_gso_send_check,
1661                 .gso_segment = inet_gso_segment,
1662                 .gro_receive = inet_gro_receive,
1663                 .gro_complete = inet_gro_complete,
1664         },
1665 };
1666
1667 static int __init ipv4_offload_init(void)
1668 {
1669         /*
1670          * Add offloads
1671          */
1672         if (inet_add_offload(&udp_offload, IPPROTO_UDP) < 0)
1673                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1674         if (inet_add_offload(&tcp_offload, IPPROTO_TCP) < 0)
1675                 pr_crit("%s: Cannot add TCP protocol offlaod\n", __func__);
1676
1677         dev_add_offload(&ip_packet_offload);
1678         return 0;
1679 }
1680
1681 fs_initcall(ipv4_offload_init);
1682
1683 static struct packet_type ip_packet_type __read_mostly = {
1684         .type = cpu_to_be16(ETH_P_IP),
1685         .func = ip_rcv,
1686 };
1687
1688 static int __init inet_init(void)
1689 {
1690         struct inet_protosw *q;
1691         struct list_head *r;
1692         int rc = -EINVAL;
1693
1694         BUILD_BUG_ON(sizeof(struct inet_skb_parm) > FIELD_SIZEOF(struct sk_buff, cb));
1695
1696         sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1697         if (!sysctl_local_reserved_ports)
1698                 goto out;
1699
1700         rc = proto_register(&tcp_prot, 1);
1701         if (rc)
1702                 goto out_free_reserved_ports;
1703
1704         rc = proto_register(&udp_prot, 1);
1705         if (rc)
1706                 goto out_unregister_tcp_proto;
1707
1708         rc = proto_register(&raw_prot, 1);
1709         if (rc)
1710                 goto out_unregister_udp_proto;
1711
1712         rc = proto_register(&ping_prot, 1);
1713         if (rc)
1714                 goto out_unregister_raw_proto;
1715
1716         /*
1717          *      Tell SOCKET that we are alive...
1718          */
1719
1720         (void)sock_register(&inet_family_ops);
1721
1722 #ifdef CONFIG_SYSCTL
1723         ip_static_sysctl_init();
1724 #endif
1725
1726         tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
1727
1728         /*
1729          *      Add all the base protocols.
1730          */
1731
1732         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1733                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1734         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1735                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1736         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1737                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1738 #ifdef CONFIG_IP_MULTICAST
1739         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1740                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1741 #endif
1742
1743         /* Register the socket-side information for inet_create. */
1744         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1745                 INIT_LIST_HEAD(r);
1746
1747         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1748                 inet_register_protosw(q);
1749
1750         /*
1751          *      Set the ARP module up
1752          */
1753
1754         arp_init();
1755
1756         /*
1757          *      Set the IP module up
1758          */
1759
1760         ip_init();
1761
1762         tcp_v4_init();
1763
1764         /* Setup TCP slab cache for open requests. */
1765         tcp_init();
1766
1767         /* Setup UDP memory threshold */
1768         udp_init();
1769
1770         /* Add UDP-Lite (RFC 3828) */
1771         udplite4_register();
1772
1773         ping_init();
1774
1775         /*
1776          *      Set the ICMP layer up
1777          */
1778
1779         if (icmp_init() < 0)
1780                 panic("Failed to create the ICMP control socket.\n");
1781
1782         /*
1783          *      Initialise the multicast router
1784          */
1785 #if defined(CONFIG_IP_MROUTE)
1786         if (ip_mr_init())
1787                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1788 #endif
1789         /*
1790          *      Initialise per-cpu ipv4 mibs
1791          */
1792
1793         if (init_ipv4_mibs())
1794                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1795
1796         ipv4_proc_init();
1797
1798         ipfrag_init();
1799
1800         dev_add_pack(&ip_packet_type);
1801
1802         rc = 0;
1803 out:
1804         return rc;
1805 out_unregister_raw_proto:
1806         proto_unregister(&raw_prot);
1807 out_unregister_udp_proto:
1808         proto_unregister(&udp_prot);
1809 out_unregister_tcp_proto:
1810         proto_unregister(&tcp_prot);
1811 out_free_reserved_ports:
1812         kfree(sysctl_local_reserved_ports);
1813         goto out;
1814 }
1815
1816 fs_initcall(inet_init);
1817
1818 /* ------------------------------------------------------------------------ */
1819
1820 #ifdef CONFIG_PROC_FS
1821 static int __init ipv4_proc_init(void)
1822 {
1823         int rc = 0;
1824
1825         if (raw_proc_init())
1826                 goto out_raw;
1827         if (tcp4_proc_init())
1828                 goto out_tcp;
1829         if (udp4_proc_init())
1830                 goto out_udp;
1831         if (ping_proc_init())
1832                 goto out_ping;
1833         if (ip_misc_proc_init())
1834                 goto out_misc;
1835 out:
1836         return rc;
1837 out_misc:
1838         ping_proc_exit();
1839 out_ping:
1840         udp4_proc_exit();
1841 out_udp:
1842         tcp4_proc_exit();
1843 out_tcp:
1844         raw_proc_exit();
1845 out_raw:
1846         rc = -ENOMEM;
1847         goto out;
1848 }
1849
1850 #else /* CONFIG_PROC_FS */
1851 static int __init ipv4_proc_init(void)
1852 {
1853         return 0;
1854 }
1855 #endif /* CONFIG_PROC_FS */
1856
1857 MODULE_ALIAS_NETPROTO(PF_INET);
1858