linux/net/ipv4/af_inet.c
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   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 */
 126static struct list_head inetsw[SOCK_MAX];
 127static DEFINE_SPINLOCK(inetsw_lock);
 128
 129struct ipv4_config ipv4_config;
 130EXPORT_SYMBOL(ipv4_config);
 131
 132/* New destruction routine */
 133
 134void 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}
 163EXPORT_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
 175static 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 */
 195int 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                err = inet_csk_listen_start(sk, backlog);
 216                if (err)
 217                        goto out;
 218        }
 219        sk->sk_max_ack_backlog = backlog;
 220        err = 0;
 221
 222out:
 223        release_sock(sk);
 224        return err;
 225}
 226EXPORT_SYMBOL(inet_listen);
 227
 228u32 inet_ehash_secret __read_mostly;
 229EXPORT_SYMBOL(inet_ehash_secret);
 230
 231/*
 232 * inet_ehash_secret must be set exactly once
 233 */
 234void build_ehash_secret(void)
 235{
 236        u32 rnd;
 237
 238        do {
 239                get_random_bytes(&rnd, sizeof(rnd));
 240        } while (rnd == 0);
 241
 242        cmpxchg(&inet_ehash_secret, 0, rnd);
 243}
 244EXPORT_SYMBOL(build_ehash_secret);
 245
 246static inline int inet_netns_ok(struct net *net, __u8 protocol)
 247{
 248        const struct net_protocol *ipprot;
 249
 250        if (net_eq(net, &init_net))
 251                return 1;
 252
 253        ipprot = rcu_dereference(inet_protos[protocol]);
 254        if (ipprot == NULL) {
 255                /* raw IP is OK */
 256                return 1;
 257        }
 258        return ipprot->netns_ok;
 259}
 260
 261/*
 262 *      Create an inet socket.
 263 */
 264
 265static int inet_create(struct net *net, struct socket *sock, int protocol,
 266                       int kern)
 267{
 268        struct sock *sk;
 269        struct inet_protosw *answer;
 270        struct inet_sock *inet;
 271        struct proto *answer_prot;
 272        unsigned char answer_flags;
 273        char answer_no_check;
 274        int try_loading_module = 0;
 275        int err;
 276
 277        if (unlikely(!inet_ehash_secret))
 278                if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
 279                        build_ehash_secret();
 280
 281        sock->state = SS_UNCONNECTED;
 282
 283        /* Look for the requested type/protocol pair. */
 284lookup_protocol:
 285        err = -ESOCKTNOSUPPORT;
 286        rcu_read_lock();
 287        list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 288
 289                err = 0;
 290                /* Check the non-wild match. */
 291                if (protocol == answer->protocol) {
 292                        if (protocol != IPPROTO_IP)
 293                                break;
 294                } else {
 295                        /* Check for the two wild cases. */
 296                        if (IPPROTO_IP == protocol) {
 297                                protocol = answer->protocol;
 298                                break;
 299                        }
 300                        if (IPPROTO_IP == answer->protocol)
 301                                break;
 302                }
 303                err = -EPROTONOSUPPORT;
 304        }
 305
 306        if (unlikely(err)) {
 307                if (try_loading_module < 2) {
 308                        rcu_read_unlock();
 309                        /*
 310                         * Be more specific, e.g. net-pf-2-proto-132-type-1
 311                         * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 312                         */
 313                        if (++try_loading_module == 1)
 314                                request_module("net-pf-%d-proto-%d-type-%d",
 315                                               PF_INET, protocol, sock->type);
 316                        /*
 317                         * Fall back to generic, e.g. net-pf-2-proto-132
 318                         * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 319                         */
 320                        else
 321                                request_module("net-pf-%d-proto-%d",
 322                                               PF_INET, protocol);
 323                        goto lookup_protocol;
 324                } else
 325                        goto out_rcu_unlock;
 326        }
 327
 328        err = -EPERM;
 329        if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
 330                goto out_rcu_unlock;
 331
 332        err = -EAFNOSUPPORT;
 333        if (!inet_netns_ok(net, protocol))
 334                goto out_rcu_unlock;
 335
 336        sock->ops = answer->ops;
 337        answer_prot = answer->prot;
 338        answer_no_check = answer->no_check;
 339        answer_flags = answer->flags;
 340        rcu_read_unlock();
 341
 342        WARN_ON(answer_prot->slab == NULL);
 343
 344        err = -ENOBUFS;
 345        sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
 346        if (sk == NULL)
 347                goto out;
 348
 349        err = 0;
 350        sk->sk_no_check = answer_no_check;
 351        if (INET_PROTOSW_REUSE & answer_flags)
 352                sk->sk_reuse = SK_CAN_REUSE;
 353
 354        inet = inet_sk(sk);
 355        inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 356
 357        inet->nodefrag = 0;
 358
 359        if (SOCK_RAW == sock->type) {
 360                inet->inet_num = protocol;
 361                if (IPPROTO_RAW == protocol)
 362                        inet->hdrincl = 1;
 363        }
 364
 365        if (ipv4_config.no_pmtu_disc)
 366                inet->pmtudisc = IP_PMTUDISC_DONT;
 367        else
 368                inet->pmtudisc = IP_PMTUDISC_WANT;
 369
 370        inet->inet_id = 0;
 371
 372        sock_init_data(sock, sk);
 373
 374        sk->sk_destruct    = inet_sock_destruct;
 375        sk->sk_protocol    = protocol;
 376        sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 377
 378        inet->uc_ttl    = -1;
 379        inet->mc_loop   = 1;
 380        inet->mc_ttl    = 1;
 381        inet->mc_all    = 1;
 382        inet->mc_index  = 0;
 383        inet->mc_list   = NULL;
 384        inet->rcv_tos   = 0;
 385
 386        sk_refcnt_debug_inc(sk);
 387
 388        if (inet->inet_num) {
 389                /* It assumes that any protocol which allows
 390                 * the user to assign a number at socket
 391                 * creation time automatically
 392                 * shares.
 393                 */
 394                inet->inet_sport = htons(inet->inet_num);
 395                /* Add to protocol hash chains. */
 396                sk->sk_prot->hash(sk);
 397        }
 398
 399        if (sk->sk_prot->init) {
 400                err = sk->sk_prot->init(sk);
 401                if (err)
 402                        sk_common_release(sk);
 403        }
 404out:
 405        return err;
 406out_rcu_unlock:
 407        rcu_read_unlock();
 408        goto out;
 409}
 410
 411
 412/*
 413 *      The peer socket should always be NULL (or else). When we call this
 414 *      function we are destroying the object and from then on nobody
 415 *      should refer to it.
 416 */
 417int inet_release(struct socket *sock)
 418{
 419        struct sock *sk = sock->sk;
 420
 421        if (sk) {
 422                long timeout;
 423
 424                sock_rps_reset_flow(sk);
 425
 426                /* Applications forget to leave groups before exiting */
 427                ip_mc_drop_socket(sk);
 428
 429                /* If linger is set, we don't return until the close
 430                 * is complete.  Otherwise we return immediately. The
 431                 * actually closing is done the same either way.
 432                 *
 433                 * If the close is due to the process exiting, we never
 434                 * linger..
 435                 */
 436                timeout = 0;
 437                if (sock_flag(sk, SOCK_LINGER) &&
 438                    !(current->flags & PF_EXITING))
 439                        timeout = sk->sk_lingertime;
 440                sock->sk = NULL;
 441                sk->sk_prot->close(sk, timeout);
 442        }
 443        return 0;
 444}
 445EXPORT_SYMBOL(inet_release);
 446
 447/* It is off by default, see below. */
 448int sysctl_ip_nonlocal_bind __read_mostly;
 449EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
 450
 451int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 452{
 453        struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 454        struct sock *sk = sock->sk;
 455        struct inet_sock *inet = inet_sk(sk);
 456        unsigned short snum;
 457        int chk_addr_ret;
 458        int err;
 459
 460        /* If the socket has its own bind function then use it. (RAW) */
 461        if (sk->sk_prot->bind) {
 462                err = sk->sk_prot->bind(sk, uaddr, addr_len);
 463                goto out;
 464        }
 465        err = -EINVAL;
 466        if (addr_len < sizeof(struct sockaddr_in))
 467                goto out;
 468
 469        if (addr->sin_family != AF_INET) {
 470                /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
 471                 * only if s_addr is INADDR_ANY.
 472                 */
 473                err = -EAFNOSUPPORT;
 474                if (addr->sin_family != AF_UNSPEC ||
 475                    addr->sin_addr.s_addr != htonl(INADDR_ANY))
 476                        goto out;
 477        }
 478
 479        chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
 480
 481        /* Not specified by any standard per-se, however it breaks too
 482         * many applications when removed.  It is unfortunate since
 483         * allowing applications to make a non-local bind solves
 484         * several problems with systems using dynamic addressing.
 485         * (ie. your servers still start up even if your ISDN link
 486         *  is temporarily down)
 487         */
 488        err = -EADDRNOTAVAIL;
 489        if (!sysctl_ip_nonlocal_bind &&
 490            !(inet->freebind || inet->transparent) &&
 491            addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
 492            chk_addr_ret != RTN_LOCAL &&
 493            chk_addr_ret != RTN_MULTICAST &&
 494            chk_addr_ret != RTN_BROADCAST)
 495                goto out;
 496
 497        snum = ntohs(addr->sin_port);
 498        err = -EACCES;
 499        if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
 500                goto out;
 501
 502        /*      We keep a pair of addresses. rcv_saddr is the one
 503         *      used by hash lookups, and saddr is used for transmit.
 504         *
 505         *      In the BSD API these are the same except where it
 506         *      would be illegal to use them (multicast/broadcast) in
 507         *      which case the sending device address is used.
 508         */
 509        lock_sock(sk);
 510
 511        /* Check these errors (active socket, double bind). */
 512        err = -EINVAL;
 513        if (sk->sk_state != TCP_CLOSE || inet->inet_num)
 514                goto out_release_sock;
 515
 516        inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
 517        if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 518                inet->inet_saddr = 0;  /* Use device */
 519
 520        /* Make sure we are allowed to bind here. */
 521        if (sk->sk_prot->get_port(sk, snum)) {
 522                inet->inet_saddr = inet->inet_rcv_saddr = 0;
 523                err = -EADDRINUSE;
 524                goto out_release_sock;
 525        }
 526
 527        if (inet->inet_rcv_saddr)
 528                sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 529        if (snum)
 530                sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 531        inet->inet_sport = htons(inet->inet_num);
 532        inet->inet_daddr = 0;
 533        inet->inet_dport = 0;
 534        sk_dst_reset(sk);
 535        err = 0;
 536out_release_sock:
 537        release_sock(sk);
 538out:
 539        return err;
 540}
 541EXPORT_SYMBOL(inet_bind);
 542
 543int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 544                       int addr_len, int flags)
 545{
 546        struct sock *sk = sock->sk;
 547
 548        if (addr_len < sizeof(uaddr->sa_family))
 549                return -EINVAL;
 550        if (uaddr->sa_family == AF_UNSPEC)
 551                return sk->sk_prot->disconnect(sk, flags);
 552
 553        if (!inet_sk(sk)->inet_num && inet_autobind(sk))
 554                return -EAGAIN;
 555        return sk->sk_prot->connect(sk, uaddr, addr_len);
 556}
 557EXPORT_SYMBOL(inet_dgram_connect);
 558
 559static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
 560{
 561        DEFINE_WAIT(wait);
 562
 563        prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 564        sk->sk_write_pending += writebias;
 565
 566        /* Basic assumption: if someone sets sk->sk_err, he _must_
 567         * change state of the socket from TCP_SYN_*.
 568         * Connect() does not allow to get error notifications
 569         * without closing the socket.
 570         */
 571        while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 572                release_sock(sk);
 573                timeo = schedule_timeout(timeo);
 574                lock_sock(sk);
 575                if (signal_pending(current) || !timeo)
 576                        break;
 577                prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 578        }
 579        finish_wait(sk_sleep(sk), &wait);
 580        sk->sk_write_pending -= writebias;
 581        return timeo;
 582}
 583
 584/*
 585 *      Connect to a remote host. There is regrettably still a little
 586 *      TCP 'magic' in here.
 587 */
 588int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 589                          int addr_len, int flags)
 590{
 591        struct sock *sk = sock->sk;
 592        int err;
 593        long timeo;
 594
 595        if (addr_len < sizeof(uaddr->sa_family))
 596                return -EINVAL;
 597
 598        if (uaddr->sa_family == AF_UNSPEC) {
 599                err = sk->sk_prot->disconnect(sk, flags);
 600                sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 601                goto out;
 602        }
 603
 604        switch (sock->state) {
 605        default:
 606                err = -EINVAL;
 607                goto out;
 608        case SS_CONNECTED:
 609                err = -EISCONN;
 610                goto out;
 611        case SS_CONNECTING:
 612                err = -EALREADY;
 613                /* Fall out of switch with err, set for this state */
 614                break;
 615        case SS_UNCONNECTED:
 616                err = -EISCONN;
 617                if (sk->sk_state != TCP_CLOSE)
 618                        goto out;
 619
 620                err = sk->sk_prot->connect(sk, uaddr, addr_len);
 621                if (err < 0)
 622                        goto out;
 623
 624                sock->state = SS_CONNECTING;
 625
 626                /* Just entered SS_CONNECTING state; the only
 627                 * difference is that return value in non-blocking
 628                 * case is EINPROGRESS, rather than EALREADY.
 629                 */
 630                err = -EINPROGRESS;
 631                break;
 632        }
 633
 634        timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 635
 636        if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 637                int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
 638                                tcp_sk(sk)->fastopen_req &&
 639                                tcp_sk(sk)->fastopen_req->data ? 1 : 0;
 640
 641                /* Error code is set above */
 642                if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
 643                        goto out;
 644
 645                err = sock_intr_errno(timeo);
 646                if (signal_pending(current))
 647                        goto out;
 648        }
 649
 650        /* Connection was closed by RST, timeout, ICMP error
 651         * or another process disconnected us.
 652         */
 653        if (sk->sk_state == TCP_CLOSE)
 654                goto sock_error;
 655
 656        /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 657         * and error was received after socket entered established state.
 658         * Hence, it is handled normally after connect() return successfully.
 659         */
 660
 661        sock->state = SS_CONNECTED;
 662        err = 0;
 663out:
 664        return err;
 665
 666sock_error:
 667        err = sock_error(sk) ? : -ECONNABORTED;
 668        sock->state = SS_UNCONNECTED;
 669        if (sk->sk_prot->disconnect(sk, flags))
 670                sock->state = SS_DISCONNECTING;
 671        goto out;
 672}
 673EXPORT_SYMBOL(__inet_stream_connect);
 674
 675int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 676                        int addr_len, int flags)
 677{
 678        int err;
 679
 680        lock_sock(sock->sk);
 681        err = __inet_stream_connect(sock, uaddr, addr_len, flags);
 682        release_sock(sock->sk);
 683        return err;
 684}
 685EXPORT_SYMBOL(inet_stream_connect);
 686
 687/*
 688 *      Accept a pending connection. The TCP layer now gives BSD semantics.
 689 */
 690
 691int inet_accept(struct socket *sock, struct socket *newsock, int flags)
 692{
 693        struct sock *sk1 = sock->sk;
 694        int err = -EINVAL;
 695        struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
 696
 697        if (!sk2)
 698                goto do_err;
 699
 700        lock_sock(sk2);
 701
 702        sock_rps_record_flow(sk2);
 703        WARN_ON(!((1 << sk2->sk_state) &
 704                  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 705
 706        sock_graft(sk2, newsock);
 707
 708        newsock->state = SS_CONNECTED;
 709        err = 0;
 710        release_sock(sk2);
 711do_err:
 712        return err;
 713}
 714EXPORT_SYMBOL(inet_accept);
 715
 716
 717/*
 718 *      This does both peername and sockname.
 719 */
 720int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 721                        int *uaddr_len, int peer)
 722{
 723        struct sock *sk         = sock->sk;
 724        struct inet_sock *inet  = inet_sk(sk);
 725        DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 726
 727        sin->sin_family = AF_INET;
 728        if (peer) {
 729                if (!inet->inet_dport ||
 730                    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 731                     peer == 1))
 732                        return -ENOTCONN;
 733                sin->sin_port = inet->inet_dport;
 734                sin->sin_addr.s_addr = inet->inet_daddr;
 735        } else {
 736                __be32 addr = inet->inet_rcv_saddr;
 737                if (!addr)
 738                        addr = inet->inet_saddr;
 739                sin->sin_port = inet->inet_sport;
 740                sin->sin_addr.s_addr = addr;
 741        }
 742        memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 743        *uaddr_len = sizeof(*sin);
 744        return 0;
 745}
 746EXPORT_SYMBOL(inet_getname);
 747
 748int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 749                 size_t size)
 750{
 751        struct sock *sk = sock->sk;
 752
 753        sock_rps_record_flow(sk);
 754
 755        /* We may need to bind the socket. */
 756        if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 757            inet_autobind(sk))
 758                return -EAGAIN;
 759
 760        return sk->sk_prot->sendmsg(iocb, sk, msg, size);
 761}
 762EXPORT_SYMBOL(inet_sendmsg);
 763
 764ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 765                      size_t size, int flags)
 766{
 767        struct sock *sk = sock->sk;
 768
 769        sock_rps_record_flow(sk);
 770
 771        /* We may need to bind the socket. */
 772        if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 773            inet_autobind(sk))
 774                return -EAGAIN;
 775
 776        if (sk->sk_prot->sendpage)
 777                return sk->sk_prot->sendpage(sk, page, offset, size, flags);
 778        return sock_no_sendpage(sock, page, offset, size, flags);
 779}
 780EXPORT_SYMBOL(inet_sendpage);
 781
 782int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 783                 size_t size, int flags)
 784{
 785        struct sock *sk = sock->sk;
 786        int addr_len = 0;
 787        int err;
 788
 789        sock_rps_record_flow(sk);
 790
 791        err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
 792                                   flags & ~MSG_DONTWAIT, &addr_len);
 793        if (err >= 0)
 794                msg->msg_namelen = addr_len;
 795        return err;
 796}
 797EXPORT_SYMBOL(inet_recvmsg);
 798
 799int inet_shutdown(struct socket *sock, int how)
 800{
 801        struct sock *sk = sock->sk;
 802        int err = 0;
 803
 804        /* This should really check to make sure
 805         * the socket is a TCP socket. (WHY AC...)
 806         */
 807        how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 808                       1->2 bit 2 snds.
 809                       2->3 */
 810        if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 811                return -EINVAL;
 812
 813        lock_sock(sk);
 814        if (sock->state == SS_CONNECTING) {
 815                if ((1 << sk->sk_state) &
 816                    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 817                        sock->state = SS_DISCONNECTING;
 818                else
 819                        sock->state = SS_CONNECTED;
 820        }
 821
 822        switch (sk->sk_state) {
 823        case TCP_CLOSE:
 824                err = -ENOTCONN;
 825                /* Hack to wake up other listeners, who can poll for
 826                   POLLHUP, even on eg. unconnected UDP sockets -- RR */
 827        default:
 828                sk->sk_shutdown |= how;
 829                if (sk->sk_prot->shutdown)
 830                        sk->sk_prot->shutdown(sk, how);
 831                break;
 832
 833        /* Remaining two branches are temporary solution for missing
 834         * close() in multithreaded environment. It is _not_ a good idea,
 835         * but we have no choice until close() is repaired at VFS level.
 836         */
 837        case TCP_LISTEN:
 838                if (!(how & RCV_SHUTDOWN))
 839                        break;
 840                /* Fall through */
 841        case TCP_SYN_SENT:
 842                err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 843                sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 844                break;
 845        }
 846
 847        /* Wake up anyone sleeping in poll. */
 848        sk->sk_state_change(sk);
 849        release_sock(sk);
 850        return err;
 851}
 852EXPORT_SYMBOL(inet_shutdown);
 853
 854/*
 855 *      ioctl() calls you can issue on an INET socket. Most of these are
 856 *      device configuration and stuff and very rarely used. Some ioctls
 857 *      pass on to the socket itself.
 858 *
 859 *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 860 *      loads the devconfigure module does its configuring and unloads it.
 861 *      There's a good 20K of config code hanging around the kernel.
 862 */
 863
 864int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 865{
 866        struct sock *sk = sock->sk;
 867        int err = 0;
 868        struct net *net = sock_net(sk);
 869
 870        switch (cmd) {
 871        case SIOCGSTAMP:
 872                err = sock_get_timestamp(sk, (struct timeval __user *)arg);
 873                break;
 874        case SIOCGSTAMPNS:
 875                err = sock_get_timestampns(sk, (struct timespec __user *)arg);
 876                break;
 877        case SIOCADDRT:
 878        case SIOCDELRT:
 879        case SIOCRTMSG:
 880                err = ip_rt_ioctl(net, cmd, (void __user *)arg);
 881                break;
 882        case SIOCDARP:
 883        case SIOCGARP:
 884        case SIOCSARP:
 885                err = arp_ioctl(net, cmd, (void __user *)arg);
 886                break;
 887        case SIOCGIFADDR:
 888        case SIOCSIFADDR:
 889        case SIOCGIFBRDADDR:
 890        case SIOCSIFBRDADDR:
 891        case SIOCGIFNETMASK:
 892        case SIOCSIFNETMASK:
 893        case SIOCGIFDSTADDR:
 894        case SIOCSIFDSTADDR:
 895        case SIOCSIFPFLAGS:
 896        case SIOCGIFPFLAGS:
 897        case SIOCSIFFLAGS:
 898                err = devinet_ioctl(net, cmd, (void __user *)arg);
 899                break;
 900        default:
 901                if (sk->sk_prot->ioctl)
 902                        err = sk->sk_prot->ioctl(sk, cmd, arg);
 903                else
 904                        err = -ENOIOCTLCMD;
 905                break;
 906        }
 907        return err;
 908}
 909EXPORT_SYMBOL(inet_ioctl);
 910
 911#ifdef CONFIG_COMPAT
 912static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 913{
 914        struct sock *sk = sock->sk;
 915        int err = -ENOIOCTLCMD;
 916
 917        if (sk->sk_prot->compat_ioctl)
 918                err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
 919
 920        return err;
 921}
 922#endif
 923
 924const struct proto_ops inet_stream_ops = {
 925        .family            = PF_INET,
 926        .owner             = THIS_MODULE,
 927        .release           = inet_release,
 928        .bind              = inet_bind,
 929        .connect           = inet_stream_connect,
 930        .socketpair        = sock_no_socketpair,
 931        .accept            = inet_accept,
 932        .getname           = inet_getname,
 933        .poll              = tcp_poll,
 934        .ioctl             = inet_ioctl,
 935        .listen            = inet_listen,
 936        .shutdown          = inet_shutdown,
 937        .setsockopt        = sock_common_setsockopt,
 938        .getsockopt        = sock_common_getsockopt,
 939        .sendmsg           = inet_sendmsg,
 940        .recvmsg           = inet_recvmsg,
 941        .mmap              = sock_no_mmap,
 942        .sendpage          = inet_sendpage,
 943        .splice_read       = tcp_splice_read,
 944#ifdef CONFIG_COMPAT
 945        .compat_setsockopt = compat_sock_common_setsockopt,
 946        .compat_getsockopt = compat_sock_common_getsockopt,
 947        .compat_ioctl      = inet_compat_ioctl,
 948#endif
 949};
 950EXPORT_SYMBOL(inet_stream_ops);
 951
 952const struct proto_ops inet_dgram_ops = {
 953        .family            = PF_INET,
 954        .owner             = THIS_MODULE,
 955        .release           = inet_release,
 956        .bind              = inet_bind,
 957        .connect           = inet_dgram_connect,
 958        .socketpair        = sock_no_socketpair,
 959        .accept            = sock_no_accept,
 960        .getname           = inet_getname,
 961        .poll              = udp_poll,
 962        .ioctl             = inet_ioctl,
 963        .listen            = sock_no_listen,
 964        .shutdown          = inet_shutdown,
 965        .setsockopt        = sock_common_setsockopt,
 966        .getsockopt        = sock_common_getsockopt,
 967        .sendmsg           = inet_sendmsg,
 968        .recvmsg           = inet_recvmsg,
 969        .mmap              = sock_no_mmap,
 970        .sendpage          = inet_sendpage,
 971#ifdef CONFIG_COMPAT
 972        .compat_setsockopt = compat_sock_common_setsockopt,
 973        .compat_getsockopt = compat_sock_common_getsockopt,
 974        .compat_ioctl      = inet_compat_ioctl,
 975#endif
 976};
 977EXPORT_SYMBOL(inet_dgram_ops);
 978
 979/*
 980 * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
 981 * udp_poll
 982 */
 983static const struct proto_ops inet_sockraw_ops = {
 984        .family            = PF_INET,
 985        .owner             = THIS_MODULE,
 986        .release           = inet_release,
 987        .bind              = inet_bind,
 988        .connect           = inet_dgram_connect,
 989        .socketpair        = sock_no_socketpair,
 990        .accept            = sock_no_accept,
 991        .getname           = inet_getname,
 992        .poll              = datagram_poll,
 993        .ioctl             = inet_ioctl,
 994        .listen            = sock_no_listen,
 995        .shutdown          = inet_shutdown,
 996        .setsockopt        = sock_common_setsockopt,
 997        .getsockopt        = sock_common_getsockopt,
 998        .sendmsg           = inet_sendmsg,
 999        .recvmsg           = inet_recvmsg,
1000        .mmap              = sock_no_mmap,
1001        .sendpage          = inet_sendpage,
1002#ifdef CONFIG_COMPAT
1003        .compat_setsockopt = compat_sock_common_setsockopt,
1004        .compat_getsockopt = compat_sock_common_getsockopt,
1005        .compat_ioctl      = inet_compat_ioctl,
1006#endif
1007};
1008
1009static const struct net_proto_family inet_family_ops = {
1010        .family = PF_INET,
1011        .create = inet_create,
1012        .owner  = THIS_MODULE,
1013};
1014
1015/* Upon startup we insert all the elements in inetsw_array[] into
1016 * the linked list inetsw.
1017 */
1018static struct inet_protosw inetsw_array[] =
1019{
1020        {
1021                .type =       SOCK_STREAM,
1022                .protocol =   IPPROTO_TCP,
1023                .prot =       &tcp_prot,
1024                .ops =        &inet_stream_ops,
1025                .no_check =   0,
1026                .flags =      INET_PROTOSW_PERMANENT |
1027                              INET_PROTOSW_ICSK,
1028        },
1029
1030        {
1031                .type =       SOCK_DGRAM,
1032                .protocol =   IPPROTO_UDP,
1033                .prot =       &udp_prot,
1034                .ops =        &inet_dgram_ops,
1035                .no_check =   UDP_CSUM_DEFAULT,
1036                .flags =      INET_PROTOSW_PERMANENT,
1037       },
1038
1039       {
1040                .type =       SOCK_DGRAM,
1041                .protocol =   IPPROTO_ICMP,
1042                .prot =       &ping_prot,
1043                .ops =        &inet_dgram_ops,
1044                .no_check =   UDP_CSUM_DEFAULT,
1045                .flags =      INET_PROTOSW_REUSE,
1046       },
1047
1048       {
1049               .type =       SOCK_RAW,
1050               .protocol =   IPPROTO_IP,        /* wild card */
1051               .prot =       &raw_prot,
1052               .ops =        &inet_sockraw_ops,
1053               .no_check =   UDP_CSUM_DEFAULT,
1054               .flags =      INET_PROTOSW_REUSE,
1055       }
1056};
1057
1058#define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1059
1060void inet_register_protosw(struct inet_protosw *p)
1061{
1062        struct list_head *lh;
1063        struct inet_protosw *answer;
1064        int protocol = p->protocol;
1065        struct list_head *last_perm;
1066
1067        spin_lock_bh(&inetsw_lock);
1068
1069        if (p->type >= SOCK_MAX)
1070                goto out_illegal;
1071
1072        /* If we are trying to override a permanent protocol, bail. */
1073        answer = NULL;
1074        last_perm = &inetsw[p->type];
1075        list_for_each(lh, &inetsw[p->type]) {
1076                answer = list_entry(lh, struct inet_protosw, list);
1077
1078                /* Check only the non-wild match. */
1079                if (INET_PROTOSW_PERMANENT & answer->flags) {
1080                        if (protocol == answer->protocol)
1081                                break;
1082                        last_perm = lh;
1083                }
1084
1085                answer = NULL;
1086        }
1087        if (answer)
1088                goto out_permanent;
1089
1090        /* Add the new entry after the last permanent entry if any, so that
1091         * the new entry does not override a permanent entry when matched with
1092         * a wild-card protocol. But it is allowed to override any existing
1093         * non-permanent entry.  This means that when we remove this entry, the
1094         * system automatically returns to the old behavior.
1095         */
1096        list_add_rcu(&p->list, last_perm);
1097out:
1098        spin_unlock_bh(&inetsw_lock);
1099
1100        return;
1101
1102out_permanent:
1103        pr_err("Attempt to override permanent protocol %d\n", protocol);
1104        goto out;
1105
1106out_illegal:
1107        pr_err("Ignoring attempt to register invalid socket type %d\n",
1108               p->type);
1109        goto out;
1110}
1111EXPORT_SYMBOL(inet_register_protosw);
1112
1113void inet_unregister_protosw(struct inet_protosw *p)
1114{
1115        if (INET_PROTOSW_PERMANENT & p->flags) {
1116                pr_err("Attempt to unregister permanent protocol %d\n",
1117                       p->protocol);
1118        } else {
1119                spin_lock_bh(&inetsw_lock);
1120                list_del_rcu(&p->list);
1121                spin_unlock_bh(&inetsw_lock);
1122
1123                synchronize_net();
1124        }
1125}
1126EXPORT_SYMBOL(inet_unregister_protosw);
1127
1128/*
1129 *      Shall we try to damage output packets if routing dev changes?
1130 */
1131
1132int sysctl_ip_dynaddr __read_mostly;
1133
1134static int inet_sk_reselect_saddr(struct sock *sk)
1135{
1136        struct inet_sock *inet = inet_sk(sk);
1137        __be32 old_saddr = inet->inet_saddr;
1138        __be32 daddr = inet->inet_daddr;
1139        struct flowi4 *fl4;
1140        struct rtable *rt;
1141        __be32 new_saddr;
1142        struct ip_options_rcu *inet_opt;
1143
1144        inet_opt = rcu_dereference_protected(inet->inet_opt,
1145                                             sock_owned_by_user(sk));
1146        if (inet_opt && inet_opt->opt.srr)
1147                daddr = inet_opt->opt.faddr;
1148
1149        /* Query new route. */
1150        fl4 = &inet->cork.fl.u.ip4;
1151        rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1152                              sk->sk_bound_dev_if, sk->sk_protocol,
1153                              inet->inet_sport, inet->inet_dport, sk, false);
1154        if (IS_ERR(rt))
1155                return PTR_ERR(rt);
1156
1157        sk_setup_caps(sk, &rt->dst);
1158
1159        new_saddr = fl4->saddr;
1160
1161        if (new_saddr == old_saddr)
1162                return 0;
1163
1164        if (sysctl_ip_dynaddr > 1) {
1165                pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1166                        __func__, &old_saddr, &new_saddr);
1167        }
1168
1169        inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1170
1171        /*
1172         * XXX The only one ugly spot where we need to
1173         * XXX really change the sockets identity after
1174         * XXX it has entered the hashes. -DaveM
1175         *
1176         * Besides that, it does not check for connection
1177         * uniqueness. Wait for troubles.
1178         */
1179        __sk_prot_rehash(sk);
1180        return 0;
1181}
1182
1183int inet_sk_rebuild_header(struct sock *sk)
1184{
1185        struct inet_sock *inet = inet_sk(sk);
1186        struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1187        __be32 daddr;
1188        struct ip_options_rcu *inet_opt;
1189        struct flowi4 *fl4;
1190        int err;
1191
1192        /* Route is OK, nothing to do. */
1193        if (rt)
1194                return 0;
1195
1196        /* Reroute. */
1197        rcu_read_lock();
1198        inet_opt = rcu_dereference(inet->inet_opt);
1199        daddr = inet->inet_daddr;
1200        if (inet_opt && inet_opt->opt.srr)
1201                daddr = inet_opt->opt.faddr;
1202        rcu_read_unlock();
1203        fl4 = &inet->cork.fl.u.ip4;
1204        rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1205                                   inet->inet_dport, inet->inet_sport,
1206                                   sk->sk_protocol, RT_CONN_FLAGS(sk),
1207                                   sk->sk_bound_dev_if);
1208        if (!IS_ERR(rt)) {
1209                err = 0;
1210                sk_setup_caps(sk, &rt->dst);
1211        } else {
1212                err = PTR_ERR(rt);
1213
1214                /* Routing failed... */
1215                sk->sk_route_caps = 0;
1216                /*
1217                 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1218                 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1219                 */
1220                if (!sysctl_ip_dynaddr ||
1221                    sk->sk_state != TCP_SYN_SENT ||
1222                    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1223                    (err = inet_sk_reselect_saddr(sk)) != 0)
1224                        sk->sk_err_soft = -err;
1225        }
1226
1227        return err;
1228}
1229EXPORT_SYMBOL(inet_sk_rebuild_header);
1230
1231static int inet_gso_send_check(struct sk_buff *skb)
1232{
1233        const struct net_protocol *ops;
1234        const struct iphdr *iph;
1235        int proto;
1236        int ihl;
1237        int err = -EINVAL;
1238
1239        if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1240                goto out;
1241
1242        iph = ip_hdr(skb);
1243        ihl = iph->ihl * 4;
1244        if (ihl < sizeof(*iph))
1245                goto out;
1246
1247        if (unlikely(!pskb_may_pull(skb, ihl)))
1248                goto out;
1249
1250        __skb_pull(skb, ihl);
1251        skb_reset_transport_header(skb);
1252        iph = ip_hdr(skb);
1253        proto = iph->protocol;
1254        err = -EPROTONOSUPPORT;
1255
1256        rcu_read_lock();
1257        ops = rcu_dereference(inet_protos[proto]);
1258        if (likely(ops && ops->gso_send_check))
1259                err = ops->gso_send_check(skb);
1260        rcu_read_unlock();
1261
1262out:
1263        return err;
1264}
1265
1266static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1267        netdev_features_t features)
1268{
1269        struct sk_buff *segs = ERR_PTR(-EINVAL);
1270        const struct net_protocol *ops;
1271        struct iphdr *iph;
1272        int proto;
1273        int ihl;
1274        int id;
1275        unsigned int offset = 0;
1276
1277        if (!(features & NETIF_F_V4_CSUM))
1278                features &= ~NETIF_F_SG;
1279
1280        if (unlikely(skb_shinfo(skb)->gso_type &
1281                     ~(SKB_GSO_TCPV4 |
1282                       SKB_GSO_UDP |
1283                       SKB_GSO_DODGY |
1284                       SKB_GSO_TCP_ECN |
1285                       0)))
1286                goto out;
1287
1288        if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1289                goto out;
1290
1291        iph = ip_hdr(skb);
1292        ihl = iph->ihl * 4;
1293        if (ihl < sizeof(*iph))
1294                goto out;
1295
1296        if (unlikely(!pskb_may_pull(skb, ihl)))
1297                goto out;
1298
1299        __skb_pull(skb, ihl);
1300        skb_reset_transport_header(skb);
1301        iph = ip_hdr(skb);
1302        id = ntohs(iph->id);
1303        proto = iph->protocol;
1304        segs = ERR_PTR(-EPROTONOSUPPORT);
1305
1306        rcu_read_lock();
1307        ops = rcu_dereference(inet_protos[proto]);
1308        if (likely(ops && ops->gso_segment))
1309                segs = ops->gso_segment(skb, features);
1310        rcu_read_unlock();
1311
1312        if (!segs || IS_ERR(segs))
1313                goto out;
1314
1315        skb = segs;
1316        do {
1317                iph = ip_hdr(skb);
1318                if (proto == IPPROTO_UDP) {
1319                        iph->id = htons(id);
1320                        iph->frag_off = htons(offset >> 3);
1321                        if (skb->next != NULL)
1322                                iph->frag_off |= htons(IP_MF);
1323                        offset += (skb->len - skb->mac_len - iph->ihl * 4);
1324                } else
1325                        iph->id = htons(id++);
1326                iph->tot_len = htons(skb->len - skb->mac_len);
1327                iph->check = 0;
1328                iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1329        } while ((skb = skb->next));
1330
1331out:
1332        return segs;
1333}
1334
1335static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1336                                         struct sk_buff *skb)
1337{
1338        const struct net_protocol *ops;
1339        struct sk_buff **pp = NULL;
1340        struct sk_buff *p;
1341        const struct iphdr *iph;
1342        unsigned int hlen;
1343        unsigned int off;
1344        unsigned int id;
1345        int flush = 1;
1346        int proto;
1347
1348        off = skb_gro_offset(skb);
1349        hlen = off + sizeof(*iph);
1350        iph = skb_gro_header_fast(skb, off);
1351        if (skb_gro_header_hard(skb, hlen)) {
1352                iph = skb_gro_header_slow(skb, hlen, off);
1353                if (unlikely(!iph))
1354                        goto out;
1355        }
1356
1357        proto = iph->protocol;
1358
1359        rcu_read_lock();
1360        ops = rcu_dereference(inet_protos[proto]);
1361        if (!ops || !ops->gro_receive)
1362                goto out_unlock;
1363
1364        if (*(u8 *)iph != 0x45)
1365                goto out_unlock;
1366
1367        if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1368                goto out_unlock;
1369
1370        id = ntohl(*(__be32 *)&iph->id);
1371        flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1372        id >>= 16;
1373
1374        for (p = *head; p; p = p->next) {
1375                struct iphdr *iph2;
1376
1377                if (!NAPI_GRO_CB(p)->same_flow)
1378                        continue;
1379
1380                iph2 = ip_hdr(p);
1381
1382                if ((iph->protocol ^ iph2->protocol) |
1383                    (iph->tos ^ iph2->tos) |
1384                    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1385                    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1386                        NAPI_GRO_CB(p)->same_flow = 0;
1387                        continue;
1388                }
1389
1390                /* All fields must match except length and checksum. */
1391                NAPI_GRO_CB(p)->flush |=
1392                        (iph->ttl ^ iph2->ttl) |
1393                        ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1394
1395                NAPI_GRO_CB(p)->flush |= flush;
1396        }
1397
1398        NAPI_GRO_CB(skb)->flush |= flush;
1399        skb_gro_pull(skb, sizeof(*iph));
1400        skb_set_transport_header(skb, skb_gro_offset(skb));
1401
1402        pp = ops->gro_receive(head, skb);
1403
1404out_unlock:
1405        rcu_read_unlock();
1406
1407out:
1408        NAPI_GRO_CB(skb)->flush |= flush;
1409
1410        return pp;
1411}
1412
1413static int inet_gro_complete(struct sk_buff *skb)
1414{
1415        __be16 newlen = htons(skb->len - skb_network_offset(skb));
1416        struct iphdr *iph = ip_hdr(skb);
1417        const struct net_protocol *ops;
1418        int proto = iph->protocol;
1419        int err = -ENOSYS;
1420
1421        csum_replace2(&iph->check, iph->tot_len, newlen);
1422        iph->tot_len = newlen;
1423
1424        rcu_read_lock();
1425        ops = rcu_dereference(inet_protos[proto]);
1426        if (WARN_ON(!ops || !ops->gro_complete))
1427                goto out_unlock;
1428
1429        err = ops->gro_complete(skb);
1430
1431out_unlock:
1432        rcu_read_unlock();
1433
1434        return err;
1435}
1436
1437int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1438                         unsigned short type, unsigned char protocol,
1439                         struct net *net)
1440{
1441        struct socket *sock;
1442        int rc = sock_create_kern(family, type, protocol, &sock);
1443
1444        if (rc == 0) {
1445                *sk = sock->sk;
1446                (*sk)->sk_allocation = GFP_ATOMIC;
1447                /*
1448                 * Unhash it so that IP input processing does not even see it,
1449                 * we do not wish this socket to see incoming packets.
1450                 */
1451                (*sk)->sk_prot->unhash(*sk);
1452
1453                sk_change_net(*sk, net);
1454        }
1455        return rc;
1456}
1457EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1458
1459unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1460{
1461        unsigned long res = 0;
1462        int i, j;
1463
1464        for_each_possible_cpu(i) {
1465                for (j = 0; j < SNMP_ARRAY_SZ; j++)
1466                        res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1467        }
1468        return res;
1469}
1470EXPORT_SYMBOL_GPL(snmp_fold_field);
1471
1472#if BITS_PER_LONG==32
1473
1474u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1475{
1476        u64 res = 0;
1477        int cpu;
1478
1479        for_each_possible_cpu(cpu) {
1480                void *bhptr;
1481                struct u64_stats_sync *syncp;
1482                u64 v;
1483                unsigned int start;
1484
1485                bhptr = per_cpu_ptr(mib[0], cpu);
1486                syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1487                do {
1488                        start = u64_stats_fetch_begin_bh(syncp);
1489                        v = *(((u64 *) bhptr) + offt);
1490                } while (u64_stats_fetch_retry_bh(syncp, start));
1491
1492                res += v;
1493        }
1494        return res;
1495}
1496EXPORT_SYMBOL_GPL(snmp_fold_field64);
1497#endif
1498
1499int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1500{
1501        BUG_ON(ptr == NULL);
1502        ptr[0] = __alloc_percpu(mibsize, align);
1503        if (!ptr[0])
1504                return -ENOMEM;
1505#if SNMP_ARRAY_SZ == 2
1506        ptr[1] = __alloc_percpu(mibsize, align);
1507        if (!ptr[1]) {
1508                free_percpu(ptr[0]);
1509                ptr[0] = NULL;
1510                return -ENOMEM;
1511        }
1512#endif
1513        return 0;
1514}
1515EXPORT_SYMBOL_GPL(snmp_mib_init);
1516
1517void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
1518{
1519        int i;
1520
1521        BUG_ON(ptr == NULL);
1522        for (i = 0; i < SNMP_ARRAY_SZ; i++) {
1523                free_percpu(ptr[i]);
1524                ptr[i] = NULL;
1525        }
1526}
1527EXPORT_SYMBOL_GPL(snmp_mib_free);
1528
1529#ifdef CONFIG_IP_MULTICAST
1530static const struct net_protocol igmp_protocol = {
1531        .handler =      igmp_rcv,
1532        .netns_ok =     1,
1533};
1534#endif
1535
1536static const struct net_protocol tcp_protocol = {
1537        .early_demux    =       tcp_v4_early_demux,
1538        .handler        =       tcp_v4_rcv,
1539        .err_handler    =       tcp_v4_err,
1540        .gso_send_check =       tcp_v4_gso_send_check,
1541        .gso_segment    =       tcp_tso_segment,
1542        .gro_receive    =       tcp4_gro_receive,
1543        .gro_complete   =       tcp4_gro_complete,
1544        .no_policy      =       1,
1545        .netns_ok       =       1,
1546};
1547
1548static const struct net_protocol udp_protocol = {
1549        .handler =      udp_rcv,
1550        .err_handler =  udp_err,
1551        .gso_send_check = udp4_ufo_send_check,
1552        .gso_segment = udp4_ufo_fragment,
1553        .no_policy =    1,
1554        .netns_ok =     1,
1555};
1556
1557static const struct net_protocol icmp_protocol = {
1558        .handler =      icmp_rcv,
1559        .err_handler =  ping_err,
1560        .no_policy =    1,
1561        .netns_ok =     1,
1562};
1563
1564static __net_init int ipv4_mib_init_net(struct net *net)
1565{
1566        if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1567                          sizeof(struct tcp_mib),
1568                          __alignof__(struct tcp_mib)) < 0)
1569                goto err_tcp_mib;
1570        if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1571                          sizeof(struct ipstats_mib),
1572                          __alignof__(struct ipstats_mib)) < 0)
1573                goto err_ip_mib;
1574        if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1575                          sizeof(struct linux_mib),
1576                          __alignof__(struct linux_mib)) < 0)
1577                goto err_net_mib;
1578        if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1579                          sizeof(struct udp_mib),
1580                          __alignof__(struct udp_mib)) < 0)
1581                goto err_udp_mib;
1582        if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1583                          sizeof(struct udp_mib),
1584                          __alignof__(struct udp_mib)) < 0)
1585                goto err_udplite_mib;
1586        if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1587                          sizeof(struct icmp_mib),
1588                          __alignof__(struct icmp_mib)) < 0)
1589                goto err_icmp_mib;
1590        net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1591                                              GFP_KERNEL);
1592        if (!net->mib.icmpmsg_statistics)
1593                goto err_icmpmsg_mib;
1594
1595        tcp_mib_init(net);
1596        return 0;
1597
1598err_icmpmsg_mib:
1599        snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1600err_icmp_mib:
1601        snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1602err_udplite_mib:
1603        snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1604err_udp_mib:
1605        snmp_mib_free((void __percpu **)net->mib.net_statistics);
1606err_net_mib:
1607        snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1608err_ip_mib:
1609        snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1610err_tcp_mib:
1611        return -ENOMEM;
1612}
1613
1614static __net_exit void ipv4_mib_exit_net(struct net *net)
1615{
1616        kfree(net->mib.icmpmsg_statistics);
1617        snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1618        snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1619        snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1620        snmp_mib_free((void __percpu **)net->mib.net_statistics);
1621        snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1622        snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1623}
1624
1625static __net_initdata struct pernet_operations ipv4_mib_ops = {
1626        .init = ipv4_mib_init_net,
1627        .exit = ipv4_mib_exit_net,
1628};
1629
1630static int __init init_ipv4_mibs(void)
1631{
1632        return register_pernet_subsys(&ipv4_mib_ops);
1633}
1634
1635static int ipv4_proc_init(void);
1636
1637/*
1638 *      IP protocol layer initialiser
1639 */
1640
1641static struct packet_type ip_packet_type __read_mostly = {
1642        .type = cpu_to_be16(ETH_P_IP),
1643        .func = ip_rcv,
1644        .gso_send_check = inet_gso_send_check,
1645        .gso_segment = inet_gso_segment,
1646        .gro_receive = inet_gro_receive,
1647        .gro_complete = inet_gro_complete,
1648};
1649
1650static int __init inet_init(void)
1651{
1652        struct sk_buff *dummy_skb;
1653        struct inet_protosw *q;
1654        struct list_head *r;
1655        int rc = -EINVAL;
1656
1657        BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1658
1659        sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1660        if (!sysctl_local_reserved_ports)
1661                goto out;
1662
1663        rc = proto_register(&tcp_prot, 1);
1664        if (rc)
1665                goto out_free_reserved_ports;
1666
1667        rc = proto_register(&udp_prot, 1);
1668        if (rc)
1669                goto out_unregister_tcp_proto;
1670
1671        rc = proto_register(&raw_prot, 1);
1672        if (rc)
1673                goto out_unregister_udp_proto;
1674
1675        rc = proto_register(&ping_prot, 1);
1676        if (rc)
1677                goto out_unregister_raw_proto;
1678
1679        /*
1680         *      Tell SOCKET that we are alive...
1681         */
1682
1683        (void)sock_register(&inet_family_ops);
1684
1685#ifdef CONFIG_SYSCTL
1686        ip_static_sysctl_init();
1687#endif
1688
1689        tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
1690
1691        /*
1692         *      Add all the base protocols.
1693         */
1694
1695        if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1696                pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1697        if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1698                pr_crit("%s: Cannot add UDP protocol\n", __func__);
1699        if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1700                pr_crit("%s: Cannot add TCP protocol\n", __func__);
1701#ifdef CONFIG_IP_MULTICAST
1702        if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1703                pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1704#endif
1705
1706        /* Register the socket-side information for inet_create. */
1707        for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1708                INIT_LIST_HEAD(r);
1709
1710        for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1711                inet_register_protosw(q);
1712
1713        /*
1714         *      Set the ARP module up
1715         */
1716
1717        arp_init();
1718
1719        /*
1720         *      Set the IP module up
1721         */
1722
1723        ip_init();
1724
1725        tcp_v4_init();
1726
1727        /* Setup TCP slab cache for open requests. */
1728        tcp_init();
1729
1730        /* Setup UDP memory threshold */
1731        udp_init();
1732
1733        /* Add UDP-Lite (RFC 3828) */
1734        udplite4_register();
1735
1736        ping_init();
1737
1738        /*
1739         *      Set the ICMP layer up
1740         */
1741
1742        if (icmp_init() < 0)
1743                panic("Failed to create the ICMP control socket.\n");
1744
1745        /*
1746         *      Initialise the multicast router
1747         */
1748#if defined(CONFIG_IP_MROUTE)
1749        if (ip_mr_init())
1750                pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1751#endif
1752        /*
1753         *      Initialise per-cpu ipv4 mibs
1754         */
1755
1756        if (init_ipv4_mibs())
1757                pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1758
1759        ipv4_proc_init();
1760
1761        ipfrag_init();
1762
1763        dev_add_pack(&ip_packet_type);
1764
1765        rc = 0;
1766out:
1767        return rc;
1768out_unregister_raw_proto:
1769        proto_unregister(&raw_prot);
1770out_unregister_udp_proto:
1771        proto_unregister(&udp_prot);
1772out_unregister_tcp_proto:
1773        proto_unregister(&tcp_prot);
1774out_free_reserved_ports:
1775        kfree(sysctl_local_reserved_ports);
1776        goto out;
1777}
1778
1779fs_initcall(inet_init);
1780
1781/* ------------------------------------------------------------------------ */
1782
1783#ifdef CONFIG_PROC_FS
1784static int __init ipv4_proc_init(void)
1785{
1786        int rc = 0;
1787
1788        if (raw_proc_init())
1789                goto out_raw;
1790        if (tcp4_proc_init())
1791                goto out_tcp;
1792        if (udp4_proc_init())
1793                goto out_udp;
1794        if (ping_proc_init())
1795                goto out_ping;
1796        if (ip_misc_proc_init())
1797                goto out_misc;
1798out:
1799        return rc;
1800out_misc:
1801        ping_proc_exit();
1802out_ping:
1803        udp4_proc_exit();
1804out_udp:
1805        tcp4_proc_exit();
1806out_tcp:
1807        raw_proc_exit();
1808out_raw:
1809        rc = -ENOMEM;
1810        goto out;
1811}
1812
1813#else /* CONFIG_PROC_FS */
1814static int __init ipv4_proc_init(void)
1815{
1816        return 0;
1817}
1818#endif /* CONFIG_PROC_FS */
1819
1820MODULE_ALIAS_NETPROTO(PF_INET);
1821
1822
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