Pileus Git - ~andy/linux/blob - 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 static inline int inet_netns_ok(struct net *net, __u8 protocol)
 267 {
 268         const struct net_protocol *ipprot;
 269
 270         if (net_eq(net, &init_net))
 271                 return 1;
 272
 273         ipprot = rcu_dereference(inet_protos[protocol]);
 274         if (ipprot == NULL) {
 275                 /* raw IP is OK */
 276                 return 1;
 277         }
 278         return ipprot->netns_ok;
 279 }
 280
 281 /*
 282  *      Create an inet socket.
 283  */
 284
 285 static int inet_create(struct net *net, struct socket *sock, int protocol,
 286                        int kern)
 287 {
 288         struct sock *sk;
 289         struct inet_protosw *answer;
 290         struct inet_sock *inet;
 291         struct proto *answer_prot;
 292         unsigned char answer_flags;
 293         char answer_no_check;
 294         int try_loading_module = 0;
 295         int err;
 296
 297         if (unlikely(!inet_ehash_secret))
 298                 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
 299                         build_ehash_secret();
 300
 301         sock->state = SS_UNCONNECTED;
 302
 303         /* Look for the requested type/protocol pair. */
 304 lookup_protocol:
 305         err = -ESOCKTNOSUPPORT;
 306         rcu_read_lock();
 307         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 308
 309                 err = 0;
 310                 /* Check the non-wild match. */
 311                 if (protocol == answer->protocol) {
 312                         if (protocol != IPPROTO_IP)
 313                                 break;
 314                 } else {
 315                         /* Check for the two wild cases. */
 316                         if (IPPROTO_IP == protocol) {
 317                                 protocol = answer->protocol;
 318                                 break;
 319                         }
 320                         if (IPPROTO_IP == answer->protocol)
 321                                 break;
 322                 }
 323                 err = -EPROTONOSUPPORT;
 324         }
 325
 326         if (unlikely(err)) {
 327                 if (try_loading_module < 2) {
 328                         rcu_read_unlock();
 329                         /*
 330                          * Be more specific, e.g. net-pf-2-proto-132-type-1
 331                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 332                          */
 333                         if (++try_loading_module == 1)
 334                                 request_module("net-pf-%d-proto-%d-type-%d",
 335                                                PF_INET, protocol, sock->type);
 336                         /*
 337                          * Fall back to generic, e.g. net-pf-2-proto-132
 338                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 339                          */
 340                         else
 341                                 request_module("net-pf-%d-proto-%d",
 342                                                PF_INET, protocol);
 343                         goto lookup_protocol;
 344                 } else
 345                         goto out_rcu_unlock;
 346         }
 347
 348         err = -EPERM;
 349         if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
 350                 goto out_rcu_unlock;
 351
 352         err = -EAFNOSUPPORT;
 353         if (!inet_netns_ok(net, protocol))
 354                 goto out_rcu_unlock;
 355
 356         sock->ops = answer->ops;
 357         answer_prot = answer->prot;
 358         answer_no_check = answer->no_check;
 359         answer_flags = answer->flags;
 360         rcu_read_unlock();
 361
 362         WARN_ON(answer_prot->slab == NULL);
 363
 364         err = -ENOBUFS;
 365         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
 366         if (sk == NULL)
 367                 goto out;
 368
 369         err = 0;
 370         sk->sk_no_check = answer_no_check;
 371         if (INET_PROTOSW_REUSE & answer_flags)
 372                 sk->sk_reuse = SK_CAN_REUSE;
 373
 374         inet = inet_sk(sk);
 375         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 376
 377         inet->nodefrag = 0;
 378
 379         if (SOCK_RAW == sock->type) {
 380                 inet->inet_num = protocol;
 381                 if (IPPROTO_RAW == protocol)
 382                         inet->hdrincl = 1;
 383         }
 384
 385         if (ipv4_config.no_pmtu_disc)
 386                 inet->pmtudisc = IP_PMTUDISC_DONT;
 387         else
 388                 inet->pmtudisc = IP_PMTUDISC_WANT;
 389
 390         inet->inet_id = 0;
 391
 392         sock_init_data(sock, sk);
 393
 394         sk->sk_destruct    = inet_sock_destruct;
 395         sk->sk_protocol    = protocol;
 396         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 397
 398         inet->uc_ttl    = -1;
 399         inet->mc_loop   = 1;
 400         inet->mc_ttl    = 1;
 401         inet->mc_all    = 1;
 402         inet->mc_index  = 0;
 403         inet->mc_list   = NULL;
 404         inet->rcv_tos   = 0;
 405
 406         sk_refcnt_debug_inc(sk);
 407
 408         if (inet->inet_num) {
 409                 /* It assumes that any protocol which allows
 410                  * the user to assign a number at socket
 411                  * creation time automatically
 412                  * shares.
 413                  */
 414                 inet->inet_sport = htons(inet->inet_num);
 415                 /* Add to protocol hash chains. */
 416                 sk->sk_prot->hash(sk);
 417         }
 418
 419         if (sk->sk_prot->init) {
 420                 err = sk->sk_prot->init(sk);
 421                 if (err)
 422                         sk_common_release(sk);
 423         }
 424 out:
 425         return err;
 426 out_rcu_unlock:
 427         rcu_read_unlock();
 428         goto out;
 429 }
 430
 431
 432 /*
 433  *      The peer socket should always be NULL (or else). When we call this
 434  *      function we are destroying the object and from then on nobody
 435  *      should refer to it.
 436  */
 437 int inet_release(struct socket *sock)
 438 {
 439         struct sock *sk = sock->sk;
 440
 441         if (sk) {
 442                 long timeout;
 443
 444                 sock_rps_reset_flow(sk);
 445
 446                 /* Applications forget to leave groups before exiting */
 447                 ip_mc_drop_socket(sk);
 448
 449                 /* If linger is set, we don't return until the close
 450                  * is complete.  Otherwise we return immediately. The
 451                  * actually closing is done the same either way.
 452                  *
 453                  * If the close is due to the process exiting, we never
 454                  * linger..
 455                  */
 456                 timeout = 0;
 457                 if (sock_flag(sk, SOCK_LINGER) &&
 458                     !(current->flags & PF_EXITING))
 459                         timeout = sk->sk_lingertime;
 460                 sock->sk = NULL;
 461                 sk->sk_prot->close(sk, timeout);
 462         }
 463         return 0;
 464 }
 465 EXPORT_SYMBOL(inet_release);
 466
 467 /* It is off by default, see below. */
 468 int sysctl_ip_nonlocal_bind __read_mostly;
 469 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
 470
 471 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 472 {
 473         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 474         struct sock *sk = sock->sk;
 475         struct inet_sock *inet = inet_sk(sk);
 476         unsigned short snum;
 477         int chk_addr_ret;
 478         int err;
 479
 480         /* If the socket has its own bind function then use it. (RAW) */
 481         if (sk->sk_prot->bind) {
 482                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
 483                 goto out;
 484         }
 485         err = -EINVAL;
 486         if (addr_len < sizeof(struct sockaddr_in))
 487                 goto out;
 488
 489         if (addr->sin_family != AF_INET) {
 490                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
 491                  * only if s_addr is INADDR_ANY.
 492                  */
 493                 err = -EAFNOSUPPORT;
 494                 if (addr->sin_family != AF_UNSPEC ||
 495                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
 496                         goto out;
 497         }
 498
 499         chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
 500
 501         /* Not specified by any standard per-se, however it breaks too
 502          * many applications when removed.  It is unfortunate since
 503          * allowing applications to make a non-local bind solves
 504          * several problems with systems using dynamic addressing.
 505          * (ie. your servers still start up even if your ISDN link
 506          *  is temporarily down)
 507          */
 508         err = -EADDRNOTAVAIL;
 509         if (!sysctl_ip_nonlocal_bind &&
 510             !(inet->freebind || inet->transparent) &&
 511             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
 512             chk_addr_ret != RTN_LOCAL &&
 513             chk_addr_ret != RTN_MULTICAST &&
 514             chk_addr_ret != RTN_BROADCAST)
 515                 goto out;
 516
 517         snum = ntohs(addr->sin_port);
 518         err = -EACCES;
 519         if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
 520                 goto out;
 521
 522         /*      We keep a pair of addresses. rcv_saddr is the one
 523          *      used by hash lookups, and saddr is used for transmit.
 524          *
 525          *      In the BSD API these are the same except where it
 526          *      would be illegal to use them (multicast/broadcast) in
 527          *      which case the sending device address is used.
 528          */
 529         lock_sock(sk);
 530
 531         /* Check these errors (active socket, double bind). */
 532         err = -EINVAL;
 533         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
 534                 goto out_release_sock;
 535
 536         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
 537         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 538                 inet->inet_saddr = 0;  /* Use device */
 539
 540         /* Make sure we are allowed to bind here. */
 541         if (sk->sk_prot->get_port(sk, snum)) {
 542                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
 543                 err = -EADDRINUSE;
 544                 goto out_release_sock;
 545         }
 546
 547         if (inet->inet_rcv_saddr)
 548                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 549         if (snum)
 550                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 551         inet->inet_sport = htons(inet->inet_num);
 552         inet->inet_daddr = 0;
 553         inet->inet_dport = 0;
 554         sk_dst_reset(sk);
 555         err = 0;
 556 out_release_sock:
 557         release_sock(sk);
 558 out:
 559         return err;
 560 }
 561 EXPORT_SYMBOL(inet_bind);
 562
 563 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 564                        int addr_len, int flags)
 565 {
 566         struct sock *sk = sock->sk;
 567
 568         if (addr_len < sizeof(uaddr->sa_family))
 569                 return -EINVAL;
 570         if (uaddr->sa_family == AF_UNSPEC)
 571                 return sk->sk_prot->disconnect(sk, flags);
 572
 573         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
 574                 return -EAGAIN;
 575         return sk->sk_prot->connect(sk, uaddr, addr_len);
 576 }
 577 EXPORT_SYMBOL(inet_dgram_connect);
 578
 579 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
 580 {
 581         DEFINE_WAIT(wait);
 582
 583         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 584         sk->sk_write_pending += writebias;
 585
 586         /* Basic assumption: if someone sets sk->sk_err, he _must_
 587          * change state of the socket from TCP_SYN_*.
 588          * Connect() does not allow to get error notifications
 589          * without closing the socket.
 590          */
 591         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 592                 release_sock(sk);
 593                 timeo = schedule_timeout(timeo);
 594                 lock_sock(sk);
 595                 if (signal_pending(current) || !timeo)
 596                         break;
 597                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 598         }
 599         finish_wait(sk_sleep(sk), &wait);
 600         sk->sk_write_pending -= writebias;
 601         return timeo;
 602 }
 603
 604 /*
 605  *      Connect to a remote host. There is regrettably still a little
 606  *      TCP 'magic' in here.
 607  */
 608 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 609                           int addr_len, int flags)
 610 {
 611         struct sock *sk = sock->sk;
 612         int err;
 613         long timeo;
 614
 615         if (addr_len < sizeof(uaddr->sa_family))
 616                 return -EINVAL;
 617
 618         if (uaddr->sa_family == AF_UNSPEC) {
 619                 err = sk->sk_prot->disconnect(sk, flags);
 620                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 621                 goto out;
 622         }
 623
 624         switch (sock->state) {
 625         default:
 626                 err = -EINVAL;
 627                 goto out;
 628         case SS_CONNECTED:
 629                 err = -EISCONN;
 630                 goto out;
 631         case SS_CONNECTING:
 632                 err = -EALREADY;
 633                 /* Fall out of switch with err, set for this state */
 634                 break;
 635         case SS_UNCONNECTED:
 636                 err = -EISCONN;
 637                 if (sk->sk_state != TCP_CLOSE)
 638                         goto out;
 639
 640                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
 641                 if (err < 0)
 642                         goto out;
 643
 644                 sock->state = SS_CONNECTING;
 645
 646                 /* Just entered SS_CONNECTING state; the only
 647                  * difference is that return value in non-blocking
 648                  * case is EINPROGRESS, rather than EALREADY.
 649                  */
 650                 err = -EINPROGRESS;
 651                 break;
 652         }
 653
 654         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 655
 656         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 657                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
 658                                 tcp_sk(sk)->fastopen_req &&
 659                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
 660
 661                 /* Error code is set above */
 662                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
 663                         goto out;
 664
 665                 err = sock_intr_errno(timeo);
 666                 if (signal_pending(current))
 667                         goto out;
 668         }
 669
 670         /* Connection was closed by RST, timeout, ICMP error
 671          * or another process disconnected us.
 672          */
 673         if (sk->sk_state == TCP_CLOSE)
 674                 goto sock_error;
 675
 676         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 677          * and error was received after socket entered established state.
 678          * Hence, it is handled normally after connect() return successfully.
 679          */
 680
 681         sock->state = SS_CONNECTED;
 682         err = 0;
 683 out:
 684         return err;
 685
 686 sock_error:
 687         err = sock_error(sk) ? : -ECONNABORTED;
 688         sock->state = SS_UNCONNECTED;
 689         if (sk->sk_prot->disconnect(sk, flags))
 690                 sock->state = SS_DISCONNECTING;
 691         goto out;
 692 }
 693 EXPORT_SYMBOL(__inet_stream_connect);
 694
 695 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 696                         int addr_len, int flags)
 697 {
 698         int err;
 699
 700         lock_sock(sock->sk);
 701         err = __inet_stream_connect(sock, uaddr, addr_len, flags);
 702         release_sock(sock->sk);
 703         return err;
 704 }
 705 EXPORT_SYMBOL(inet_stream_connect);
 706
 707 /*
 708  *      Accept a pending connection. The TCP layer now gives BSD semantics.
 709  */
 710
 711 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
 712 {
 713         struct sock *sk1 = sock->sk;
 714         int err = -EINVAL;
 715         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
 716
 717         if (!sk2)
 718                 goto do_err;
 719
 720         lock_sock(sk2);
 721
 722         sock_rps_record_flow(sk2);
 723         WARN_ON(!((1 << sk2->sk_state) &
 724                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
 725                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 726
 727         sock_graft(sk2, newsock);
 728
 729         newsock->state = SS_CONNECTED;
 730         err = 0;
 731         release_sock(sk2);
 732 do_err:
 733         return err;
 734 }
 735 EXPORT_SYMBOL(inet_accept);
 736
 737
 738 /*
 739  *      This does both peername and sockname.
 740  */
 741 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 742                         int *uaddr_len, int peer)
 743 {
 744         struct sock *sk         = sock->sk;
 745         struct inet_sock *inet  = inet_sk(sk);
 746         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 747
 748         sin->sin_family = AF_INET;
 749         if (peer) {
 750                 if (!inet->inet_dport ||
 751                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 752                      peer == 1))
 753                         return -ENOTCONN;
 754                 sin->sin_port = inet->inet_dport;
 755                 sin->sin_addr.s_addr = inet->inet_daddr;
 756         } else {
 757                 __be32 addr = inet->inet_rcv_saddr;
 758                 if (!addr)
 759                         addr = inet->inet_saddr;
 760                 sin->sin_port = inet->inet_sport;
 761                 sin->sin_addr.s_addr = addr;
 762         }
 763         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 764         *uaddr_len = sizeof(*sin);
 765         return 0;
 766 }
 767 EXPORT_SYMBOL(inet_getname);
 768
 769 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 770                  size_t size)
 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         return sk->sk_prot->sendmsg(iocb, sk, msg, size);
 782 }
 783 EXPORT_SYMBOL(inet_sendmsg);
 784
 785 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 786                       size_t size, int flags)
 787 {
 788         struct sock *sk = sock->sk;
 789
 790         sock_rps_record_flow(sk);
 791
 792         /* We may need to bind the socket. */
 793         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 794             inet_autobind(sk))
 795                 return -EAGAIN;
 796
 797         if (sk->sk_prot->sendpage)
 798                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
 799         return sock_no_sendpage(sock, page, offset, size, flags);
 800 }
 801 EXPORT_SYMBOL(inet_sendpage);
 802
 803 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 804                  size_t size, int flags)
 805 {
 806         struct sock *sk = sock->sk;
 807         int addr_len = 0;
 808         int err;
 809
 810         sock_rps_record_flow(sk);
 811
 812         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
 813                                    flags & ~MSG_DONTWAIT, &addr_len);
 814         if (err >= 0)
 815                 msg->msg_namelen = addr_len;
 816         return err;
 817 }
 818 EXPORT_SYMBOL(inet_recvmsg);
 819
 820 int inet_shutdown(struct socket *sock, int how)
 821 {
 822         struct sock *sk = sock->sk;
 823         int err = 0;
 824
 825         /* This should really check to make sure
 826          * the socket is a TCP socket. (WHY AC...)
 827          */
 828         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 829                        1->2 bit 2 snds.
 830                        2->3 */
 831         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 832                 return -EINVAL;
 833
 834         lock_sock(sk);
 835         if (sock->state == SS_CONNECTING) {
 836                 if ((1 << sk->sk_state) &
 837                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 838                         sock->state = SS_DISCONNECTING;
 839                 else
 840                         sock->state = SS_CONNECTED;
 841         }
 842
 843         switch (sk->sk_state) {
 844         case TCP_CLOSE:
 845                 err = -ENOTCONN;
 846                 /* Hack to wake up other listeners, who can poll for
 847                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
 848         default:
 849                 sk->sk_shutdown |= how;
 850                 if (sk->sk_prot->shutdown)
 851                         sk->sk_prot->shutdown(sk, how);
 852                 break;
 853
 854         /* Remaining two branches are temporary solution for missing
 855          * close() in multithreaded environment. It is _not_ a good idea,
 856          * but we have no choice until close() is repaired at VFS level.
 857          */
 858         case TCP_LISTEN:
 859                 if (!(how & RCV_SHUTDOWN))
 860                         break;
 861                 /* Fall through */
 862         case TCP_SYN_SENT:
 863                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 864                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 865                 break;
 866         }
 867
 868         /* Wake up anyone sleeping in poll. */
 869         sk->sk_state_change(sk);
 870         release_sock(sk);
 871         return err;
 872 }
 873 EXPORT_SYMBOL(inet_shutdown);
 874
 875 /*
 876  *      ioctl() calls you can issue on an INET socket. Most of these are
 877  *      device configuration and stuff and very rarely used. Some ioctls
 878  *      pass on to the socket itself.
 879  *
 880  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 881  *      loads the devconfigure module does its configuring and unloads it.
 882  *      There's a good 20K of config code hanging around the kernel.
 883  */
 884
 885 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 886 {
 887         struct sock *sk = sock->sk;
 888         int err = 0;
 889         struct net *net = sock_net(sk);
 890
 891         switch (cmd) {
 892         case SIOCGSTAMP:
 893                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
 894                 break;
 895         case SIOCGSTAMPNS:
 896                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
 897                 break;
 898         case SIOCADDRT:
 899         case SIOCDELRT:
 900         case SIOCRTMSG:
 901                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
 902                 break;
 903         case SIOCDARP:
 904         case SIOCGARP:
 905         case SIOCSARP:
 906                 err = arp_ioctl(net, cmd, (void __user *)arg);
 907                 break;
 908         case SIOCGIFADDR:
 909         case SIOCSIFADDR:
 910         case SIOCGIFBRDADDR:
 911         case SIOCSIFBRDADDR:
 912         case SIOCGIFNETMASK:
 913         case SIOCSIFNETMASK:
 914         case SIOCGIFDSTADDR:
 915         case SIOCSIFDSTADDR:
 916         case SIOCSIFPFLAGS:
 917         case SIOCGIFPFLAGS:
 918         case SIOCSIFFLAGS:
 919                 err = devinet_ioctl(net, cmd, (void __user *)arg);
 920                 break;
 921         default:
 922                 if (sk->sk_prot->ioctl)
 923                         err = sk->sk_prot->ioctl(sk, cmd, arg);
 924                 else
 925                         err = -ENOIOCTLCMD;
 926                 break;
 927         }
 928         return err;
 929 }
 930 EXPORT_SYMBOL(inet_ioctl);
 931
 932 #ifdef CONFIG_COMPAT
 933 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 934 {
 935         struct sock *sk = sock->sk;
 936         int err = -ENOIOCTLCMD;
 937
 938         if (sk->sk_prot->compat_ioctl)
 939                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
 940
 941         return err;
 942 }
 943 #endif
 944
 945 const struct proto_ops inet_stream_ops = {
 946         .family            = PF_INET,
 947         .owner             = THIS_MODULE,
 948         .release           = inet_release,
 949         .bind              = inet_bind,
 950         .connect           = inet_stream_connect,
 951         .socketpair        = sock_no_socketpair,
 952         .accept            = inet_accept,
 953         .getname           = inet_getname,
 954         .poll              = tcp_poll,
 955         .ioctl             = inet_ioctl,
 956         .listen            = inet_listen,
 957         .shutdown          = inet_shutdown,
 958         .setsockopt        = sock_common_setsockopt,
 959         .getsockopt        = sock_common_getsockopt,
 960         .sendmsg           = inet_sendmsg,
 961         .recvmsg           = inet_recvmsg,
 962         .mmap              = sock_no_mmap,
 963         .sendpage          = inet_sendpage,
 964         .splice_read       = tcp_splice_read,
 965 #ifdef CONFIG_COMPAT
 966         .compat_setsockopt = compat_sock_common_setsockopt,
 967         .compat_getsockopt = compat_sock_common_getsockopt,
 968         .compat_ioctl      = inet_compat_ioctl,
 969 #endif
 970 };
 971 EXPORT_SYMBOL(inet_stream_ops);
 972
 973 const struct proto_ops inet_dgram_ops = {
 974         .family            = PF_INET,
 975         .owner             = THIS_MODULE,
 976         .release           = inet_release,
 977         .bind              = inet_bind,
 978         .connect           = inet_dgram_connect,
 979         .socketpair        = sock_no_socketpair,
 980         .accept            = sock_no_accept,
 981         .getname           = inet_getname,
 982         .poll              = udp_poll,
 983         .ioctl             = inet_ioctl,
 984         .listen            = sock_no_listen,
 985         .shutdown          = inet_shutdown,
 986         .setsockopt        = sock_common_setsockopt,
 987         .getsockopt        = sock_common_getsockopt,
 988         .sendmsg           = inet_sendmsg,
 989         .recvmsg           = inet_recvmsg,
 990         .mmap              = sock_no_mmap,
 991         .sendpage          = inet_sendpage,
 992 #ifdef CONFIG_COMPAT
 993         .compat_setsockopt = compat_sock_common_setsockopt,
 994         .compat_getsockopt = compat_sock_common_getsockopt,
 995         .compat_ioctl      = inet_compat_ioctl,
 996 #endif
 997 };
 998 EXPORT_SYMBOL(inet_dgram_ops);
 999
1000 /*
1001  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1002  * udp_poll
1003  */
1004 static const struct proto_ops inet_sockraw_ops = {
1005         .family            = PF_INET,
1006         .owner             = THIS_MODULE,
1007         .release           = inet_release,
1008         .bind              = inet_bind,
1009         .connect           = inet_dgram_connect,
1010         .socketpair        = sock_no_socketpair,
1011         .accept            = sock_no_accept,
1012         .getname           = inet_getname,
1013         .poll              = datagram_poll,
1014         .ioctl             = inet_ioctl,
1015         .listen            = sock_no_listen,
1016         .shutdown          = inet_shutdown,
1017         .setsockopt        = sock_common_setsockopt,
1018         .getsockopt        = sock_common_getsockopt,
1019         .sendmsg           = inet_sendmsg,
1020         .recvmsg           = inet_recvmsg,
1021         .mmap              = sock_no_mmap,
1022         .sendpage          = inet_sendpage,
1023 #ifdef CONFIG_COMPAT
1024         .compat_setsockopt = compat_sock_common_setsockopt,
1025         .compat_getsockopt = compat_sock_common_getsockopt,
1026         .compat_ioctl      = inet_compat_ioctl,
1027 #endif
1028 };
1029
1030 static const struct net_proto_family inet_family_ops = {
1031         .family = PF_INET,
1032         .create = inet_create,
1033         .owner  = THIS_MODULE,
1034 };
1035
1036 /* Upon startup we insert all the elements in inetsw_array[] into
1037  * the linked list inetsw.
1038  */
1039 static struct inet_protosw inetsw_array[] =
1040 {
1041         {
1042                 .type =       SOCK_STREAM,
1043                 .protocol =   IPPROTO_TCP,
1044                 .prot =       &tcp_prot,
1045                 .ops =        &inet_stream_ops,
1046                 .no_check =   0,
1047                 .flags =      INET_PROTOSW_PERMANENT |
1048                               INET_PROTOSW_ICSK,
1049         },
1050
1051         {
1052                 .type =       SOCK_DGRAM,
1053                 .protocol =   IPPROTO_UDP,
1054                 .prot =       &udp_prot,
1055                 .ops =        &inet_dgram_ops,
1056                 .no_check =   UDP_CSUM_DEFAULT,
1057                 .flags =      INET_PROTOSW_PERMANENT,
1058        },
1059
1060        {
1061                 .type =       SOCK_DGRAM,
1062                 .protocol =   IPPROTO_ICMP,
1063                 .prot =       &ping_prot,
1064                 .ops =        &inet_dgram_ops,
1065                 .no_check =   UDP_CSUM_DEFAULT,
1066                 .flags =      INET_PROTOSW_REUSE,
1067        },
1068
1069        {
1070                .type =       SOCK_RAW,
1071                .protocol =   IPPROTO_IP,        /* wild card */
1072                .prot =       &raw_prot,
1073                .ops =        &inet_sockraw_ops,
1074                .no_check =   UDP_CSUM_DEFAULT,
1075                .flags =      INET_PROTOSW_REUSE,
1076        }
1077 };
1078
1079 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1080
1081 void inet_register_protosw(struct inet_protosw *p)
1082 {
1083         struct list_head *lh;
1084         struct inet_protosw *answer;
1085         int protocol = p->protocol;
1086         struct list_head *last_perm;
1087
1088         spin_lock_bh(&inetsw_lock);
1089
1090         if (p->type >= SOCK_MAX)
1091                 goto out_illegal;
1092
1093         /* If we are trying to override a permanent protocol, bail. */
1094         answer = NULL;
1095         last_perm = &inetsw[p->type];
1096         list_for_each(lh, &inetsw[p->type]) {
1097                 answer = list_entry(lh, struct inet_protosw, list);
1098
1099                 /* Check only the non-wild match. */
1100                 if (INET_PROTOSW_PERMANENT & answer->flags) {
1101                         if (protocol == answer->protocol)
1102                                 break;
1103                         last_perm = lh;
1104                 }
1105
1106                 answer = NULL;
1107         }
1108         if (answer)
1109                 goto out_permanent;
1110
1111         /* Add the new entry after the last permanent entry if any, so that
1112          * the new entry does not override a permanent entry when matched with
1113          * a wild-card protocol. But it is allowed to override any existing
1114          * non-permanent entry.  This means that when we remove this entry, the
1115          * system automatically returns to the old behavior.
1116          */
1117         list_add_rcu(&p->list, last_perm);
1118 out:
1119         spin_unlock_bh(&inetsw_lock);
1120
1121         return;
1122
1123 out_permanent:
1124         pr_err("Attempt to override permanent protocol %d\n", protocol);
1125         goto out;
1126
1127 out_illegal:
1128         pr_err("Ignoring attempt to register invalid socket type %d\n",
1129                p->type);
1130         goto out;
1131 }
1132 EXPORT_SYMBOL(inet_register_protosw);
1133
1134 void inet_unregister_protosw(struct inet_protosw *p)
1135 {
1136         if (INET_PROTOSW_PERMANENT & p->flags) {
1137                 pr_err("Attempt to unregister permanent protocol %d\n",
1138                        p->protocol);
1139         } else {
1140                 spin_lock_bh(&inetsw_lock);
1141                 list_del_rcu(&p->list);
1142                 spin_unlock_bh(&inetsw_lock);
1143
1144                 synchronize_net();
1145         }
1146 }
1147 EXPORT_SYMBOL(inet_unregister_protosw);
1148
1149 /*
1150  *      Shall we try to damage output packets if routing dev changes?
1151  */
1152
1153 int sysctl_ip_dynaddr __read_mostly;
1154
1155 static int inet_sk_reselect_saddr(struct sock *sk)
1156 {
1157         struct inet_sock *inet = inet_sk(sk);
1158         __be32 old_saddr = inet->inet_saddr;
1159         __be32 daddr = inet->inet_daddr;
1160         struct flowi4 *fl4;
1161         struct rtable *rt;
1162         __be32 new_saddr;
1163         struct ip_options_rcu *inet_opt;
1164
1165         inet_opt = rcu_dereference_protected(inet->inet_opt,
1166                                              sock_owned_by_user(sk));
1167         if (inet_opt && inet_opt->opt.srr)
1168                 daddr = inet_opt->opt.faddr;
1169
1170         /* Query new route. */
1171         fl4 = &inet->cork.fl.u.ip4;
1172         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1173                               sk->sk_bound_dev_if, sk->sk_protocol,
1174                               inet->inet_sport, inet->inet_dport, sk, false);
1175         if (IS_ERR(rt))
1176                 return PTR_ERR(rt);
1177
1178         sk_setup_caps(sk, &rt->dst);
1179
1180         new_saddr = fl4->saddr;
1181
1182         if (new_saddr == old_saddr)
1183                 return 0;
1184
1185         if (sysctl_ip_dynaddr > 1) {
1186                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1187                         __func__, &old_saddr, &new_saddr);
1188         }
1189
1190         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1191
1192         /*
1193          * XXX The only one ugly spot where we need to
1194          * XXX really change the sockets identity after
1195          * XXX it has entered the hashes. -DaveM
1196          *
1197          * Besides that, it does not check for connection
1198          * uniqueness. Wait for troubles.
1199          */
1200         __sk_prot_rehash(sk);
1201         return 0;
1202 }
1203
1204 int inet_sk_rebuild_header(struct sock *sk)
1205 {
1206         struct inet_sock *inet = inet_sk(sk);
1207         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1208         __be32 daddr;
1209         struct ip_options_rcu *inet_opt;
1210         struct flowi4 *fl4;
1211         int err;
1212
1213         /* Route is OK, nothing to do. */
1214         if (rt)
1215                 return 0;
1216
1217         /* Reroute. */
1218         rcu_read_lock();
1219         inet_opt = rcu_dereference(inet->inet_opt);
1220         daddr = inet->inet_daddr;
1221         if (inet_opt && inet_opt->opt.srr)
1222                 daddr = inet_opt->opt.faddr;
1223         rcu_read_unlock();
1224         fl4 = &inet->cork.fl.u.ip4;
1225         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1226                                    inet->inet_dport, inet->inet_sport,
1227                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1228                                    sk->sk_bound_dev_if);
1229         if (!IS_ERR(rt)) {
1230                 err = 0;
1231                 sk_setup_caps(sk, &rt->dst);
1232         } else {
1233                 err = PTR_ERR(rt);
1234
1235                 /* Routing failed... */
1236                 sk->sk_route_caps = 0;
1237                 /*
1238                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1239                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1240                  */
1241                 if (!sysctl_ip_dynaddr ||
1242                     sk->sk_state != TCP_SYN_SENT ||
1243                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1244                     (err = inet_sk_reselect_saddr(sk)) != 0)
1245                         sk->sk_err_soft = -err;
1246         }
1247
1248         return err;
1249 }
1250 EXPORT_SYMBOL(inet_sk_rebuild_header);
1251
1252 static int inet_gso_send_check(struct sk_buff *skb)
1253 {
1254         const struct net_protocol *ops;
1255         const struct iphdr *iph;
1256         int proto;
1257         int ihl;
1258         int err = -EINVAL;
1259
1260         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1261                 goto out;
1262
1263         iph = ip_hdr(skb);
1264         ihl = iph->ihl * 4;
1265         if (ihl < sizeof(*iph))
1266                 goto out;
1267
1268         if (unlikely(!pskb_may_pull(skb, ihl)))
1269                 goto out;
1270
1271         __skb_pull(skb, ihl);
1272         skb_reset_transport_header(skb);
1273         iph = ip_hdr(skb);
1274         proto = iph->protocol;
1275         err = -EPROTONOSUPPORT;
1276
1277         rcu_read_lock();
1278         ops = rcu_dereference(inet_protos[proto]);
1279         if (likely(ops && ops->gso_send_check))
1280                 err = ops->gso_send_check(skb);
1281         rcu_read_unlock();
1282
1283 out:
1284         return err;
1285 }
1286
1287 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1288         netdev_features_t features)
1289 {
1290         struct sk_buff *segs = ERR_PTR(-EINVAL);
1291         const struct net_protocol *ops;
1292         struct iphdr *iph;
1293         int proto;
1294         int ihl;
1295         int id;
1296         unsigned int offset = 0;
1297
1298         if (!(features & NETIF_F_V4_CSUM))
1299                 features &= ~NETIF_F_SG;
1300
1301         if (unlikely(skb_shinfo(skb)->gso_type &
1302                      ~(SKB_GSO_TCPV4 |
1303                        SKB_GSO_UDP |
1304                        SKB_GSO_DODGY |
1305                        SKB_GSO_TCP_ECN |
1306                        0)))
1307                 goto out;
1308
1309         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1310                 goto out;
1311
1312         iph = ip_hdr(skb);
1313         ihl = iph->ihl * 4;
1314         if (ihl < sizeof(*iph))
1315                 goto out;
1316
1317         if (unlikely(!pskb_may_pull(skb, ihl)))
1318                 goto out;
1319
1320         __skb_pull(skb, ihl);
1321         skb_reset_transport_header(skb);
1322         iph = ip_hdr(skb);
1323         id = ntohs(iph->id);
1324         proto = iph->protocol;
1325         segs = ERR_PTR(-EPROTONOSUPPORT);
1326
1327         rcu_read_lock();
1328         ops = rcu_dereference(inet_protos[proto]);
1329         if (likely(ops && ops->gso_segment))
1330                 segs = ops->gso_segment(skb, features);
1331         rcu_read_unlock();
1332
1333         if (!segs || IS_ERR(segs))
1334                 goto out;
1335
1336         skb = segs;
1337         do {
1338                 iph = ip_hdr(skb);
1339                 if (proto == IPPROTO_UDP) {
1340                         iph->id = htons(id);
1341                         iph->frag_off = htons(offset >> 3);
1342                         if (skb->next != NULL)
1343                                 iph->frag_off |= htons(IP_MF);
1344                         offset += (skb->len - skb->mac_len - iph->ihl * 4);
1345                 } else
1346                         iph->id = htons(id++);
1347                 iph->tot_len = htons(skb->len - skb->mac_len);
1348                 iph->check = 0;
1349                 iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1350         } while ((skb = skb->next));
1351
1352 out:
1353         return segs;
1354 }
1355
1356 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1357                                          struct sk_buff *skb)
1358 {
1359         const struct net_protocol *ops;
1360         struct sk_buff **pp = NULL;
1361         struct sk_buff *p;
1362         const struct iphdr *iph;
1363         unsigned int hlen;
1364         unsigned int off;
1365         unsigned int id;
1366         int flush = 1;
1367         int proto;
1368
1369         off = skb_gro_offset(skb);
1370         hlen = off + sizeof(*iph);
1371         iph = skb_gro_header_fast(skb, off);
1372         if (skb_gro_header_hard(skb, hlen)) {
1373                 iph = skb_gro_header_slow(skb, hlen, off);
1374                 if (unlikely(!iph))
1375                         goto out;
1376         }
1377
1378         proto = iph->protocol;
1379
1380         rcu_read_lock();
1381         ops = rcu_dereference(inet_protos[proto]);
1382         if (!ops || !ops->gro_receive)
1383                 goto out_unlock;
1384
1385         if (*(u8 *)iph != 0x45)
1386                 goto out_unlock;
1387
1388         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1389                 goto out_unlock;
1390
1391         id = ntohl(*(__be32 *)&iph->id);
1392         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1393         id >>= 16;
1394
1395         for (p = *head; p; p = p->next) {
1396                 struct iphdr *iph2;
1397
1398                 if (!NAPI_GRO_CB(p)->same_flow)
1399                         continue;
1400
1401                 iph2 = ip_hdr(p);
1402
1403                 if ((iph->protocol ^ iph2->protocol) |
1404                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1405                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1406                         NAPI_GRO_CB(p)->same_flow = 0;
1407                         continue;
1408                 }
1409
1410                 /* All fields must match except length and checksum. */
1411                 NAPI_GRO_CB(p)->flush |=
1412                         (iph->ttl ^ iph2->ttl) |
1413                         (iph->tos ^ iph2->tos) |
1414                         ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1415
1416                 NAPI_GRO_CB(p)->flush |= flush;
1417         }
1418
1419         NAPI_GRO_CB(skb)->flush |= flush;
1420         skb_gro_pull(skb, sizeof(*iph));
1421         skb_set_transport_header(skb, skb_gro_offset(skb));
1422
1423         pp = ops->gro_receive(head, skb);
1424
1425 out_unlock:
1426         rcu_read_unlock();
1427
1428 out:
1429         NAPI_GRO_CB(skb)->flush |= flush;
1430
1431         return pp;
1432 }
1433
1434 static int inet_gro_complete(struct sk_buff *skb)
1435 {
1436         __be16 newlen = htons(skb->len - skb_network_offset(skb));
1437         struct iphdr *iph = ip_hdr(skb);
1438         const struct net_protocol *ops;
1439         int proto = iph->protocol;
1440         int err = -ENOSYS;
1441
1442         csum_replace2(&iph->check, iph->tot_len, newlen);
1443         iph->tot_len = newlen;
1444
1445         rcu_read_lock();
1446         ops = rcu_dereference(inet_protos[proto]);
1447         if (WARN_ON(!ops || !ops->gro_complete))
1448                 goto out_unlock;
1449
1450         err = ops->gro_complete(skb);
1451
1452 out_unlock:
1453         rcu_read_unlock();
1454
1455         return err;
1456 }
1457
1458 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1459                          unsigned short type, unsigned char protocol,
1460                          struct net *net)
1461 {
1462         struct socket *sock;
1463         int rc = sock_create_kern(family, type, protocol, &sock);
1464
1465         if (rc == 0) {
1466                 *sk = sock->sk;
1467                 (*sk)->sk_allocation = GFP_ATOMIC;
1468                 /*
1469                  * Unhash it so that IP input processing does not even see it,
1470                  * we do not wish this socket to see incoming packets.
1471                  */
1472                 (*sk)->sk_prot->unhash(*sk);
1473
1474                 sk_change_net(*sk, net);
1475         }
1476         return rc;
1477 }
1478 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1479
1480 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1481 {
1482         unsigned long res = 0;
1483         int i, j;
1484
1485         for_each_possible_cpu(i) {
1486                 for (j = 0; j < SNMP_ARRAY_SZ; j++)
1487                         res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1488         }
1489         return res;
1490 }
1491 EXPORT_SYMBOL_GPL(snmp_fold_field);
1492
1493 #if BITS_PER_LONG==32
1494
1495 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1496 {
1497         u64 res = 0;
1498         int cpu;
1499
1500         for_each_possible_cpu(cpu) {
1501                 void *bhptr;
1502                 struct u64_stats_sync *syncp;
1503                 u64 v;
1504                 unsigned int start;
1505
1506                 bhptr = per_cpu_ptr(mib[0], cpu);
1507                 syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1508                 do {
1509                         start = u64_stats_fetch_begin_bh(syncp);
1510                         v = *(((u64 *) bhptr) + offt);
1511                 } while (u64_stats_fetch_retry_bh(syncp, start));
1512
1513                 res += v;
1514         }
1515         return res;
1516 }
1517 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1518 #endif
1519
1520 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1521 {
1522         BUG_ON(ptr == NULL);
1523         ptr[0] = __alloc_percpu(mibsize, align);
1524         if (!ptr[0])
1525                 return -ENOMEM;
1526 #if SNMP_ARRAY_SZ == 2
1527         ptr[1] = __alloc_percpu(mibsize, align);
1528         if (!ptr[1]) {
1529                 free_percpu(ptr[0]);
1530                 ptr[0] = NULL;
1531                 return -ENOMEM;
1532         }
1533 #endif
1534         return 0;
1535 }
1536 EXPORT_SYMBOL_GPL(snmp_mib_init);
1537
1538 void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
1539 {
1540         int i;
1541
1542         BUG_ON(ptr == NULL);
1543         for (i = 0; i < SNMP_ARRAY_SZ; i++) {
1544                 free_percpu(ptr[i]);
1545                 ptr[i] = NULL;
1546         }
1547 }
1548 EXPORT_SYMBOL_GPL(snmp_mib_free);
1549
1550 #ifdef CONFIG_IP_MULTICAST
1551 static const struct net_protocol igmp_protocol = {
1552         .handler =      igmp_rcv,
1553         .netns_ok =     1,
1554 };
1555 #endif
1556
1557 static const struct net_protocol tcp_protocol = {
1558         .early_demux    =       tcp_v4_early_demux,
1559         .handler        =       tcp_v4_rcv,
1560         .err_handler    =       tcp_v4_err,
1561         .gso_send_check =       tcp_v4_gso_send_check,
1562         .gso_segment    =       tcp_tso_segment,
1563         .gro_receive    =       tcp4_gro_receive,
1564         .gro_complete   =       tcp4_gro_complete,
1565         .no_policy      =       1,
1566         .netns_ok       =       1,
1567 };
1568
1569 static const struct net_protocol udp_protocol = {
1570         .handler =      udp_rcv,
1571         .err_handler =  udp_err,
1572         .gso_send_check = udp4_ufo_send_check,
1573         .gso_segment = udp4_ufo_fragment,
1574         .no_policy =    1,
1575         .netns_ok =     1,
1576 };
1577
1578 static const struct net_protocol icmp_protocol = {
1579         .handler =      icmp_rcv,
1580         .err_handler =  ping_err,
1581         .no_policy =    1,
1582         .netns_ok =     1,
1583 };
1584
1585 static __net_init int ipv4_mib_init_net(struct net *net)
1586 {
1587         if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1588                           sizeof(struct tcp_mib),
1589                           __alignof__(struct tcp_mib)) < 0)
1590                 goto err_tcp_mib;
1591         if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1592                           sizeof(struct ipstats_mib),
1593                           __alignof__(struct ipstats_mib)) < 0)
1594                 goto err_ip_mib;
1595         if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1596                           sizeof(struct linux_mib),
1597                           __alignof__(struct linux_mib)) < 0)
1598                 goto err_net_mib;
1599         if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1600                           sizeof(struct udp_mib),
1601                           __alignof__(struct udp_mib)) < 0)
1602                 goto err_udp_mib;
1603         if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1604                           sizeof(struct udp_mib),
1605                           __alignof__(struct udp_mib)) < 0)
1606                 goto err_udplite_mib;
1607         if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1608                           sizeof(struct icmp_mib),
1609                           __alignof__(struct icmp_mib)) < 0)
1610                 goto err_icmp_mib;
1611         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1612                                               GFP_KERNEL);
1613         if (!net->mib.icmpmsg_statistics)
1614                 goto err_icmpmsg_mib;
1615
1616         tcp_mib_init(net);
1617         return 0;
1618
1619 err_icmpmsg_mib:
1620         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1621 err_icmp_mib:
1622         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1623 err_udplite_mib:
1624         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1625 err_udp_mib:
1626         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1627 err_net_mib:
1628         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1629 err_ip_mib:
1630         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1631 err_tcp_mib:
1632         return -ENOMEM;
1633 }
1634
1635 static __net_exit void ipv4_mib_exit_net(struct net *net)
1636 {
1637         kfree(net->mib.icmpmsg_statistics);
1638         snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1639         snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1640         snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1641         snmp_mib_free((void __percpu **)net->mib.net_statistics);
1642         snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1643         snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1644 }
1645
1646 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1647         .init = ipv4_mib_init_net,
1648         .exit = ipv4_mib_exit_net,
1649 };
1650
1651 static int __init init_ipv4_mibs(void)
1652 {
1653         return register_pernet_subsys(&ipv4_mib_ops);
1654 }
1655
1656 static int ipv4_proc_init(void);
1657
1658 /*
1659  *      IP protocol layer initialiser
1660  */
1661
1662 static struct packet_type ip_packet_type __read_mostly = {
1663         .type = cpu_to_be16(ETH_P_IP),
1664         .func = ip_rcv,
1665         .gso_send_check = inet_gso_send_check,
1666         .gso_segment = inet_gso_segment,
1667         .gro_receive = inet_gro_receive,
1668         .gro_complete = inet_gro_complete,
1669 };
1670
1671 static int __init inet_init(void)
1672 {
1673         struct sk_buff *dummy_skb;
1674         struct inet_protosw *q;
1675         struct list_head *r;
1676         int rc = -EINVAL;
1677
1678         BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1679
1680         sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1681         if (!sysctl_local_reserved_ports)
1682                 goto out;
1683
1684         rc = proto_register(&tcp_prot, 1);
1685         if (rc)
1686                 goto out_free_reserved_ports;
1687
1688         rc = proto_register(&udp_prot, 1);
1689         if (rc)
1690                 goto out_unregister_tcp_proto;
1691
1692         rc = proto_register(&raw_prot, 1);
1693         if (rc)
1694                 goto out_unregister_udp_proto;
1695
1696         rc = proto_register(&ping_prot, 1);
1697         if (rc)
1698                 goto out_unregister_raw_proto;
1699
1700         /*
1701          *      Tell SOCKET that we are alive...
1702          */
1703
1704         (void)sock_register(&inet_family_ops);
1705
1706 #ifdef CONFIG_SYSCTL
1707         ip_static_sysctl_init();
1708 #endif
1709
1710         tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
1711
1712         /*
1713          *      Add all the base protocols.
1714          */
1715
1716         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1717                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1718         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1719                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1720         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1721                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1722 #ifdef CONFIG_IP_MULTICAST
1723         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1724                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1725 #endif
1726
1727         /* Register the socket-side information for inet_create. */
1728         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1729                 INIT_LIST_HEAD(r);
1730
1731         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1732                 inet_register_protosw(q);
1733
1734         /*
1735          *      Set the ARP module up
1736          */
1737
1738         arp_init();
1739
1740         /*
1741          *      Set the IP module up
1742          */
1743
1744         ip_init();
1745
1746         tcp_v4_init();
1747
1748         /* Setup TCP slab cache for open requests. */
1749         tcp_init();
1750
1751         /* Setup UDP memory threshold */
1752         udp_init();
1753
1754         /* Add UDP-Lite (RFC 3828) */
1755         udplite4_register();
1756
1757         ping_init();
1758
1759         /*
1760          *      Set the ICMP layer up
1761          */
1762
1763         if (icmp_init() < 0)
1764                 panic("Failed to create the ICMP control socket.\n");
1765
1766         /*
1767          *      Initialise the multicast router
1768          */
1769 #if defined(CONFIG_IP_MROUTE)
1770         if (ip_mr_init())
1771                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1772 #endif
1773         /*
1774          *      Initialise per-cpu ipv4 mibs
1775          */
1776
1777         if (init_ipv4_mibs())
1778                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1779
1780         ipv4_proc_init();
1781
1782         ipfrag_init();
1783
1784         dev_add_pack(&ip_packet_type);
1785
1786         rc = 0;
1787 out:
1788         return rc;
1789 out_unregister_raw_proto:
1790         proto_unregister(&raw_prot);
1791 out_unregister_udp_proto:
1792         proto_unregister(&udp_prot);
1793 out_unregister_tcp_proto:
1794         proto_unregister(&tcp_prot);
1795 out_free_reserved_ports:
1796         kfree(sysctl_local_reserved_ports);
1797         goto out;
1798 }
1799
1800 fs_initcall(inet_init);
1801
1802 /* ------------------------------------------------------------------------ */
1803
1804 #ifdef CONFIG_PROC_FS
1805 static int __init ipv4_proc_init(void)
1806 {
1807         int rc = 0;
1808
1809         if (raw_proc_init())
1810                 goto out_raw;
1811         if (tcp4_proc_init())
1812                 goto out_tcp;
1813         if (udp4_proc_init())
1814                 goto out_udp;
1815         if (ping_proc_init())
1816                 goto out_ping;
1817         if (ip_misc_proc_init())
1818                 goto out_misc;
1819 out:
1820         return rc;
1821 out_misc:
1822         ping_proc_exit();
1823 out_ping:
1824         udp4_proc_exit();
1825 out_udp:
1826         tcp4_proc_exit();
1827 out_tcp:
1828         raw_proc_exit();
1829 out_raw:
1830         rc = -ENOMEM;
1831         goto out;
1832 }
1833
1834 #else /* CONFIG_PROC_FS */
1835 static int __init ipv4_proc_init(void)
1836 {
1837         return 0;
1838 }
1839 #endif /* CONFIG_PROC_FS */
1840
1841 MODULE_ALIAS_NETPROTO(PF_INET);
1842