net/ipv4/af_inet.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4  *              operating system.  INET is implemented using the  BSD Socket
   5  *              interface as the means of communication with the user level.
   6  *
   7  *              PF_INET protocol family socket handler.
   8  *
   9  * Authors:     Ross Biro
  10  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  11  *              Florian La Roche, <flla@stud.uni-sb.de>
  12  *              Alan Cox, <A.Cox@swansea.ac.uk>
  13  *
  14  * Changes (see also sock.c)
  15  *
  16  *              piggy,
  17  *              Karl Knutson    :       Socket protocol table
  18  *              A.N.Kuznetsov   :       Socket death error in accept().
  19  *              John Richardson :       Fix non blocking error in connect()
  20  *                                      so sockets that fail to connect
  21  *                                      don't return -EINPROGRESS.
  22  *              Alan Cox        :       Asynchronous I/O support
  23  *              Alan Cox        :       Keep correct socket pointer on sock
  24  *                                      structures
  25  *                                      when accept() ed
  26  *              Alan Cox        :       Semantics of SO_LINGER aren't state
  27  *                                      moved to close when you look carefully.
  28  *                                      With this fixed and the accept bug fixed
  29  *                                      some RPC stuff seems happier.
  30  *              Niibe Yutaka    :       4.4BSD style write async I/O
  31  *              Alan Cox,
  32  *              Tony Gale       :       Fixed reuse semantics.
  33  *              Alan Cox        :       bind() shouldn't abort existing but dead
  34  *                                      sockets. Stops FTP netin:.. I hope.
  35  *              Alan Cox        :       bind() works correctly for RAW sockets.
  36  *                                      Note that FreeBSD at least was broken
  37  *                                      in this respect so be careful with
  38  *                                      compatibility tests...
  39  *              Alan Cox        :       routing cache support
  40  *              Alan Cox        :       memzero the socket structure for
  41  *                                      compactness.
  42  *              Matt Day        :       nonblock connect error handler
  43  *              Alan Cox        :       Allow large numbers of pending sockets
  44  *                                      (eg for big web sites), but only if
  45  *                                      specifically application requested.
  46  *              Alan Cox        :       New buffering throughout IP. Used
  47  *                                      dumbly.
  48  *              Alan Cox        :       New buffering now used smartly.
  49  *              Alan Cox        :       BSD rather than common sense
  50  *                                      interpretation of listen.
  51  *              Germano Caronni :       Assorted small races.
  52  *              Alan Cox        :       sendmsg/recvmsg basic support.
  53  *              Alan Cox        :       Only sendmsg/recvmsg now supported.
  54  *              Alan Cox        :       Locked down bind (see security list).
  55  *              Alan Cox        :       Loosened bind a little.
  56  *              Mike McLagan    :       ADD/DEL DLCI Ioctls
  57  *      Willy Konynenberg       :       Transparent proxying support.
  58  *              David S. Miller :       New socket lookup architecture.
  59  *                                      Some other random speedups.
  60  *              Cyrus Durgin    :       Cleaned up file for kmod hacks.
  61  *              Andi Kleen      :       Fix inet_stream_connect TCP race.
  62  */
  63
  64 #define pr_fmt(fmt) "IPv4: " fmt
  65
  66 #include <linux/err.h>
  67 #include <linux/errno.h>
  68 #include <linux/types.h>
  69 #include <linux/socket.h>
  70 #include <linux/in.h>
  71 #include <linux/kernel.h>
  72 #include <linux/kmod.h>
  73 #include <linux/sched.h>
  74 #include <linux/timer.h>
  75 #include <linux/string.h>
  76 #include <linux/sockios.h>
  77 #include <linux/net.h>
  78 #include <linux/capability.h>
  79 #include <linux/fcntl.h>
  80 #include <linux/mm.h>
  81 #include <linux/interrupt.h>
  82 #include <linux/stat.h>
  83 #include <linux/init.h>
  84 #include <linux/poll.h>
  85 #include <linux/netfilter_ipv4.h>
  86 #include <linux/random.h>
  87 #include <linux/slab.h>
  88
  89 #include <linux/uaccess.h>
  90
  91 #include <linux/inet.h>
  92 #include <linux/igmp.h>
  93 #include <linux/inetdevice.h>
  94 #include <linux/netdevice.h>
  95 #include <net/checksum.h>
  96 #include <net/ip.h>
  97 #include <net/protocol.h>
  98 #include <net/arp.h>
  99 #include <net/route.h>
 100 #include <net/ip_fib.h>
 101 #include <net/inet_connection_sock.h>
 102 #include <net/gro.h>
 103 #include <net/gso.h>
 104 #include <net/tcp.h>
 105 #include <net/udp.h>
 106 #include <net/udplite.h>
 107 #include <net/ping.h>
 108 #include <linux/skbuff.h>
 109 #include <net/sock.h>
 110 #include <net/raw.h>
 111 #include <net/icmp.h>
 112 #include <net/inet_common.h>
 113 #include <net/ip_tunnels.h>
 114 #include <net/xfrm.h>
 115 #include <net/net_namespace.h>
 116 #include <net/secure_seq.h>
 117 #ifdef CONFIG_IP_MROUTE
 118 #include <linux/mroute.h>
 119 #endif
 120 #include <net/l3mdev.h>
 121 #include <net/compat.h>
 122
 123 #include <trace/events/sock.h>
 124
 125 /* The inetsw table contains everything that inet_create needs to
 126  * build a new socket.
 127  */
 128 static struct list_head inetsw[SOCK_MAX];
 129 static DEFINE_SPINLOCK(inetsw_lock);
 130
 131 /* New destruction routine */
 132
 133 void inet_sock_destruct(struct sock *sk)
 134 {
 135         struct inet_sock *inet = inet_sk(sk);
 136
 137         __skb_queue_purge(&sk->sk_receive_queue);
 138         __skb_queue_purge(&sk->sk_error_queue);
 139
 140         sk_mem_reclaim_final(sk);
 141
 142         if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
 143                 pr_err("Attempt to release TCP socket in state %d %p\n",
 144                        sk->sk_state, sk);
 145                 return;
 146         }
 147         if (!sock_flag(sk, SOCK_DEAD)) {
 148                 pr_err("Attempt to release alive inet socket %p\n", sk);
 149                 return;
 150         }
 151
 152         WARN_ON_ONCE(atomic_read(&sk->sk_rmem_alloc));
 153         WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc));
 154         WARN_ON_ONCE(sk->sk_wmem_queued);
 155         WARN_ON_ONCE(sk_forward_alloc_get(sk));
 156
 157         kfree(rcu_dereference_protected(inet->inet_opt, 1));
 158         dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
 159         dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
 160 }
 161 EXPORT_SYMBOL(inet_sock_destruct);
 162
 163 /*
 164  *      The routines beyond this point handle the behaviour of an AF_INET
 165  *      socket object. Mostly it punts to the subprotocols of IP to do
 166  *      the work.
 167  */
 168
 169 /*
 170  *      Automatically bind an unbound socket.
 171  */
 172
 173 static int inet_autobind(struct sock *sk)
 174 {
 175         struct inet_sock *inet;
 176         /* We may need to bind the socket. */
 177         lock_sock(sk);
 178         inet = inet_sk(sk);
 179         if (!inet->inet_num) {
 180                 if (sk->sk_prot->get_port(sk, 0)) {
 181                         release_sock(sk);
 182                         return -EAGAIN;
 183                 }
 184                 inet->inet_sport = htons(inet->inet_num);
 185         }
 186         release_sock(sk);
 187         return 0;
 188 }
 189
 190 /*
 191  *      Move a socket into listening state.
 192  */
 193 int inet_listen(struct socket *sock, int backlog)
 194 {
 195         struct sock *sk = sock->sk;
 196         unsigned char old_state;
 197         int err, tcp_fastopen;
 198
 199         lock_sock(sk);
 200
 201         err = -EINVAL;
 202         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
 203                 goto out;
 204
 205         old_state = sk->sk_state;
 206         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 207                 goto out;
 208
 209         WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
 210         /* Really, if the socket is already in listen state
 211          * we can only allow the backlog to be adjusted.
 212          */
 213         if (old_state != TCP_LISTEN) {
 214                 /* Enable TFO w/o requiring TCP_FASTOPEN socket option.
 215                  * Note that only TCP sockets (SOCK_STREAM) will reach here.
 216                  * Also fastopen backlog may already been set via the option
 217                  * because the socket was in TCP_LISTEN state previously but
 218                  * was shutdown() rather than close().
 219                  */
 220                 tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
 221                 if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
 222                     (tcp_fastopen & TFO_SERVER_ENABLE) &&
 223                     !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
 224                         fastopen_queue_tune(sk, backlog);
 225                         tcp_fastopen_init_key_once(sock_net(sk));
 226                 }
 227
 228                 err = inet_csk_listen_start(sk);
 229                 if (err)
 230                         goto out;
 231                 tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
 232         }
 233         err = 0;
 234
 235 out:
 236         release_sock(sk);
 237         return err;
 238 }
 239 EXPORT_SYMBOL(inet_listen);
 240
 241 /*
 242  *      Create an inet socket.
 243  */
 244
 245 static int inet_create(struct net *net, struct socket *sock, int protocol,
 246                        int kern)
 247 {
 248         struct sock *sk;
 249         struct inet_protosw *answer;
 250         struct inet_sock *inet;
 251         struct proto *answer_prot;
 252         unsigned char answer_flags;
 253         int try_loading_module = 0;
 254         int err;
 255
 256         if (protocol < 0 || protocol >= IPPROTO_MAX)
 257                 return -EINVAL;
 258
 259         sock->state = SS_UNCONNECTED;
 260
 261         /* Look for the requested type/protocol pair. */
 262 lookup_protocol:
 263         err = -ESOCKTNOSUPPORT;
 264         rcu_read_lock();
 265         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 266
 267                 err = 0;
 268                 /* Check the non-wild match. */
 269                 if (protocol == answer->protocol) {
 270                         if (protocol != IPPROTO_IP)
 271                                 break;
 272                 } else {
 273                         /* Check for the two wild cases. */
 274                         if (IPPROTO_IP == protocol) {
 275                                 protocol = answer->protocol;
 276                                 break;
 277                         }
 278                         if (IPPROTO_IP == answer->protocol)
 279                                 break;
 280                 }
 281                 err = -EPROTONOSUPPORT;
 282         }
 283
 284         if (unlikely(err)) {
 285                 if (try_loading_module < 2) {
 286                         rcu_read_unlock();
 287                         /*
 288                          * Be more specific, e.g. net-pf-2-proto-132-type-1
 289                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 290                          */
 291                         if (++try_loading_module == 1)
 292                                 request_module("net-pf-%d-proto-%d-type-%d",
 293                                                PF_INET, protocol, sock->type);
 294                         /*
 295                          * Fall back to generic, e.g. net-pf-2-proto-132
 296                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 297                          */
 298                         else
 299                                 request_module("net-pf-%d-proto-%d",
 300                                                PF_INET, protocol);
 301                         goto lookup_protocol;
 302                 } else
 303                         goto out_rcu_unlock;
 304         }
 305
 306         err = -EPERM;
 307         if (sock->type == SOCK_RAW && !kern &&
 308             !ns_capable(net->user_ns, CAP_NET_RAW))
 309                 goto out_rcu_unlock;
 310
 311         sock->ops = answer->ops;
 312         answer_prot = answer->prot;
 313         answer_flags = answer->flags;
 314         rcu_read_unlock();
 315
 316         WARN_ON(!answer_prot->slab);
 317
 318         err = -ENOMEM;
 319         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
 320         if (!sk)
 321                 goto out;
 322
 323         err = 0;
 324         if (INET_PROTOSW_REUSE & answer_flags)
 325                 sk->sk_reuse = SK_CAN_REUSE;
 326
 327         inet = inet_sk(sk);
 328         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 329
 330         inet->nodefrag = 0;
 331
 332         if (SOCK_RAW == sock->type) {
 333                 inet->inet_num = protocol;
 334                 if (IPPROTO_RAW == protocol)
 335                         inet->hdrincl = 1;
 336         }
 337
 338         if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
 339                 inet->pmtudisc = IP_PMTUDISC_DONT;
 340         else
 341                 inet->pmtudisc = IP_PMTUDISC_WANT;
 342
 343         inet->inet_id = 0;
 344
 345         sock_init_data(sock, sk);
 346
 347         sk->sk_destruct    = inet_sock_destruct;
 348         sk->sk_protocol    = protocol;
 349         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 350         sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
 351
 352         inet->uc_ttl    = -1;
 353         inet->mc_loop   = 1;
 354         inet->mc_ttl    = 1;
 355         inet->mc_all    = 1;
 356         inet->mc_index  = 0;
 357         inet->mc_list   = NULL;
 358         inet->rcv_tos   = 0;
 359
 360         if (inet->inet_num) {
 361                 /* It assumes that any protocol which allows
 362                  * the user to assign a number at socket
 363                  * creation time automatically
 364                  * shares.
 365                  */
 366                 inet->inet_sport = htons(inet->inet_num);
 367                 /* Add to protocol hash chains. */
 368                 err = sk->sk_prot->hash(sk);
 369                 if (err) {
 370                         sk_common_release(sk);
 371                         goto out;
 372                 }
 373         }
 374
 375         if (sk->sk_prot->init) {
 376                 err = sk->sk_prot->init(sk);
 377                 if (err) {
 378                         sk_common_release(sk);
 379                         goto out;
 380                 }
 381         }
 382
 383         if (!kern) {
 384                 err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
 385                 if (err) {
 386                         sk_common_release(sk);
 387                         goto out;
 388                 }
 389         }
 390 out:
 391         return err;
 392 out_rcu_unlock:
 393         rcu_read_unlock();
 394         goto out;
 395 }
 396
 397
 398 /*
 399  *      The peer socket should always be NULL (or else). When we call this
 400  *      function we are destroying the object and from then on nobody
 401  *      should refer to it.
 402  */
 403 int inet_release(struct socket *sock)
 404 {
 405         struct sock *sk = sock->sk;
 406
 407         if (sk) {
 408                 long timeout;
 409
 410                 if (!sk->sk_kern_sock)
 411                         BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
 412
 413                 /* Applications forget to leave groups before exiting */
 414                 ip_mc_drop_socket(sk);
 415
 416                 /* If linger is set, we don't return until the close
 417                  * is complete.  Otherwise we return immediately. The
 418                  * actually closing is done the same either way.
 419                  *
 420                  * If the close is due to the process exiting, we never
 421                  * linger..
 422                  */
 423                 timeout = 0;
 424                 if (sock_flag(sk, SOCK_LINGER) &&
 425                     !(current->flags & PF_EXITING))
 426                         timeout = sk->sk_lingertime;
 427                 sk->sk_prot->close(sk, timeout);
 428                 sock->sk = NULL;
 429         }
 430         return 0;
 431 }
 432 EXPORT_SYMBOL(inet_release);
 433
 434 int inet_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 435 {
 436         u32 flags = BIND_WITH_LOCK;
 437         int err;
 438
 439         /* If the socket has its own bind function then use it. (RAW) */
 440         if (sk->sk_prot->bind) {
 441                 return sk->sk_prot->bind(sk, uaddr, addr_len);
 442         }
 443         if (addr_len < sizeof(struct sockaddr_in))
 444                 return -EINVAL;
 445
 446         /* BPF prog is run before any checks are done so that if the prog
 447          * changes context in a wrong way it will be caught.
 448          */
 449         err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr,
 450                                                  CGROUP_INET4_BIND, &flags);
 451         if (err)
 452                 return err;
 453
 454         return __inet_bind(sk, uaddr, addr_len, flags);
 455 }
 456
 457 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 458 {
 459         return inet_bind_sk(sock->sk, uaddr, addr_len);
 460 }
 461 EXPORT_SYMBOL(inet_bind);
 462
 463 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
 464                 u32 flags)
 465 {
 466         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 467         struct inet_sock *inet = inet_sk(sk);
 468         struct net *net = sock_net(sk);
 469         unsigned short snum;
 470         int chk_addr_ret;
 471         u32 tb_id = RT_TABLE_LOCAL;
 472         int err;
 473
 474         if (addr->sin_family != AF_INET) {
 475                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
 476                  * only if s_addr is INADDR_ANY.
 477                  */
 478                 err = -EAFNOSUPPORT;
 479                 if (addr->sin_family != AF_UNSPEC ||
 480                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
 481                         goto out;
 482         }
 483
 484         tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
 485         chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
 486
 487         /* Not specified by any standard per-se, however it breaks too
 488          * many applications when removed.  It is unfortunate since
 489          * allowing applications to make a non-local bind solves
 490          * several problems with systems using dynamic addressing.
 491          * (ie. your servers still start up even if your ISDN link
 492          *  is temporarily down)
 493          */
 494         err = -EADDRNOTAVAIL;
 495         if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,
 496                                          chk_addr_ret))
 497                 goto out;
 498
 499         snum = ntohs(addr->sin_port);
 500         err = -EACCES;
 501         if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
 502             snum && inet_port_requires_bind_service(net, snum) &&
 503             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
 504                 goto out;
 505
 506         /*      We keep a pair of addresses. rcv_saddr is the one
 507          *      used by hash lookups, and saddr is used for transmit.
 508          *
 509          *      In the BSD API these are the same except where it
 510          *      would be illegal to use them (multicast/broadcast) in
 511          *      which case the sending device address is used.
 512          */
 513         if (flags & BIND_WITH_LOCK)
 514                 lock_sock(sk);
 515
 516         /* Check these errors (active socket, double bind). */
 517         err = -EINVAL;
 518         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
 519                 goto out_release_sock;
 520
 521         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
 522         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 523                 inet->inet_saddr = 0;  /* Use device */
 524
 525         /* Make sure we are allowed to bind here. */
 526         if (snum || !(inet->bind_address_no_port ||
 527                       (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
 528                 err = sk->sk_prot->get_port(sk, snum);
 529                 if (err) {
 530                         inet->inet_saddr = inet->inet_rcv_saddr = 0;
 531                         goto out_release_sock;
 532                 }
 533                 if (!(flags & BIND_FROM_BPF)) {
 534                         err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
 535                         if (err) {
 536                                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
 537                                 if (sk->sk_prot->put_port)
 538                                         sk->sk_prot->put_port(sk);
 539                                 goto out_release_sock;
 540                         }
 541                 }
 542         }
 543
 544         if (inet->inet_rcv_saddr)
 545                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 546         if (snum)
 547                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 548         inet->inet_sport = htons(inet->inet_num);
 549         inet->inet_daddr = 0;
 550         inet->inet_dport = 0;
 551         sk_dst_reset(sk);
 552         err = 0;
 553 out_release_sock:
 554         if (flags & BIND_WITH_LOCK)
 555                 release_sock(sk);
 556 out:
 557         return err;
 558 }
 559
 560 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 561                        int addr_len, int flags)
 562 {
 563         struct sock *sk = sock->sk;
 564         const struct proto *prot;
 565         int err;
 566
 567         if (addr_len < sizeof(uaddr->sa_family))
 568                 return -EINVAL;
 569
 570         /* IPV6_ADDRFORM can change sk->sk_prot under us. */
 571         prot = READ_ONCE(sk->sk_prot);
 572
 573         if (uaddr->sa_family == AF_UNSPEC)
 574                 return prot->disconnect(sk, flags);
 575
 576         if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
 577                 err = prot->pre_connect(sk, uaddr, addr_len);
 578                 if (err)
 579                         return err;
 580         }
 581
 582         if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
 583                 return -EAGAIN;
 584         return prot->connect(sk, uaddr, addr_len);
 585 }
 586 EXPORT_SYMBOL(inet_dgram_connect);
 587
 588 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
 589 {
 590         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 591
 592         add_wait_queue(sk_sleep(sk), &wait);
 593         sk->sk_write_pending += writebias;
 594         sk->sk_wait_pending++;
 595
 596         /* Basic assumption: if someone sets sk->sk_err, he _must_
 597          * change state of the socket from TCP_SYN_*.
 598          * Connect() does not allow to get error notifications
 599          * without closing the socket.
 600          */
 601         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 602                 release_sock(sk);
 603                 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
 604                 lock_sock(sk);
 605                 if (signal_pending(current) || !timeo)
 606                         break;
 607         }
 608         remove_wait_queue(sk_sleep(sk), &wait);
 609         sk->sk_write_pending -= writebias;
 610         sk->sk_wait_pending--;
 611         return timeo;
 612 }
 613
 614 /*
 615  *      Connect to a remote host. There is regrettably still a little
 616  *      TCP 'magic' in here.
 617  */
 618 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 619                           int addr_len, int flags, int is_sendmsg)
 620 {
 621         struct sock *sk = sock->sk;
 622         int err;
 623         long timeo;
 624
 625         /*
 626          * uaddr can be NULL and addr_len can be 0 if:
 627          * sk is a TCP fastopen active socket and
 628          * TCP_FASTOPEN_CONNECT sockopt is set and
 629          * we already have a valid cookie for this socket.
 630          * In this case, user can call write() after connect().
 631          * write() will invoke tcp_sendmsg_fastopen() which calls
 632          * __inet_stream_connect().
 633          */
 634         if (uaddr) {
 635                 if (addr_len < sizeof(uaddr->sa_family))
 636                         return -EINVAL;
 637
 638                 if (uaddr->sa_family == AF_UNSPEC) {
 639                         err = sk->sk_prot->disconnect(sk, flags);
 640                         sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 641                         goto out;
 642                 }
 643         }
 644
 645         switch (sock->state) {
 646         default:
 647                 err = -EINVAL;
 648                 goto out;
 649         case SS_CONNECTED:
 650                 err = -EISCONN;
 651                 goto out;
 652         case SS_CONNECTING:
 653                 if (inet_sk(sk)->defer_connect)
 654                         err = is_sendmsg ? -EINPROGRESS : -EISCONN;
 655                 else
 656                         err = -EALREADY;
 657                 /* Fall out of switch with err, set for this state */
 658                 break;
 659         case SS_UNCONNECTED:
 660                 err = -EISCONN;
 661                 if (sk->sk_state != TCP_CLOSE)
 662                         goto out;
 663
 664                 if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
 665                         err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
 666                         if (err)
 667                                 goto out;
 668                 }
 669
 670                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
 671                 if (err < 0)
 672                         goto out;
 673
 674                 sock->state = SS_CONNECTING;
 675
 676                 if (!err && inet_sk(sk)->defer_connect)
 677                         goto out;
 678
 679                 /* Just entered SS_CONNECTING state; the only
 680                  * difference is that return value in non-blocking
 681                  * case is EINPROGRESS, rather than EALREADY.
 682                  */
 683                 err = -EINPROGRESS;
 684                 break;
 685         }
 686
 687         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 688
 689         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 690                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
 691                                 tcp_sk(sk)->fastopen_req &&
 692                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
 693
 694                 /* Error code is set above */
 695                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
 696                         goto out;
 697
 698                 err = sock_intr_errno(timeo);
 699                 if (signal_pending(current))
 700                         goto out;
 701         }
 702
 703         /* Connection was closed by RST, timeout, ICMP error
 704          * or another process disconnected us.
 705          */
 706         if (sk->sk_state == TCP_CLOSE)
 707                 goto sock_error;
 708
 709         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 710          * and error was received after socket entered established state.
 711          * Hence, it is handled normally after connect() return successfully.
 712          */
 713
 714         sock->state = SS_CONNECTED;
 715         err = 0;
 716 out:
 717         return err;
 718
 719 sock_error:
 720         err = sock_error(sk) ? : -ECONNABORTED;
 721         sock->state = SS_UNCONNECTED;
 722         if (sk->sk_prot->disconnect(sk, flags))
 723                 sock->state = SS_DISCONNECTING;
 724         goto out;
 725 }
 726 EXPORT_SYMBOL(__inet_stream_connect);
 727
 728 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 729                         int addr_len, int flags)
 730 {
 731         int err;
 732
 733         lock_sock(sock->sk);
 734         err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
 735         release_sock(sock->sk);
 736         return err;
 737 }
 738 EXPORT_SYMBOL(inet_stream_connect);
 739
 740 void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
 741 {
 742         sock_rps_record_flow(newsk);
 743         WARN_ON(!((1 << newsk->sk_state) &
 744                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
 745                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 746
 747         if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
 748                 set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
 749         sock_graft(newsk, newsock);
 750
 751         newsock->state = SS_CONNECTED;
 752 }
 753
 754 /*
 755  *      Accept a pending connection. The TCP layer now gives BSD semantics.
 756  */
 757
 758 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
 759                 bool kern)
 760 {
 761         struct sock *sk1 = sock->sk, *sk2;
 762         int err = -EINVAL;
 763
 764         /* IPV6_ADDRFORM can change sk->sk_prot under us. */
 765         sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
 766         if (!sk2)
 767                 return err;
 768
 769         lock_sock(sk2);
 770         __inet_accept(sock, newsock, sk2);
 771         release_sock(sk2);
 772         return 0;
 773 }
 774 EXPORT_SYMBOL(inet_accept);
 775
 776 /*
 777  *      This does both peername and sockname.
 778  */
 779 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 780                  int peer)
 781 {
 782         struct sock *sk         = sock->sk;
 783         struct inet_sock *inet  = inet_sk(sk);
 784         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 785
 786         sin->sin_family = AF_INET;
 787         lock_sock(sk);
 788         if (peer) {
 789                 if (!inet->inet_dport ||
 790                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 791                      peer == 1)) {
 792                         release_sock(sk);
 793                         return -ENOTCONN;
 794                 }
 795                 sin->sin_port = inet->inet_dport;
 796                 sin->sin_addr.s_addr = inet->inet_daddr;
 797                 BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
 798                                        CGROUP_INET4_GETPEERNAME);
 799         } else {
 800                 __be32 addr = inet->inet_rcv_saddr;
 801                 if (!addr)
 802                         addr = inet->inet_saddr;
 803                 sin->sin_port = inet->inet_sport;
 804                 sin->sin_addr.s_addr = addr;
 805                 BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
 806                                        CGROUP_INET4_GETSOCKNAME);
 807         }
 808         release_sock(sk);
 809         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 810         return sizeof(*sin);
 811 }
 812 EXPORT_SYMBOL(inet_getname);
 813
 814 int inet_send_prepare(struct sock *sk)
 815 {
 816         sock_rps_record_flow(sk);
 817
 818         /* We may need to bind the socket. */
 819         if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
 820             inet_autobind(sk))
 821                 return -EAGAIN;
 822
 823         return 0;
 824 }
 825 EXPORT_SYMBOL_GPL(inet_send_prepare);
 826
 827 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 828 {
 829         struct sock *sk = sock->sk;
 830
 831         if (unlikely(inet_send_prepare(sk)))
 832                 return -EAGAIN;
 833
 834         return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
 835                                sk, msg, size);
 836 }
 837 EXPORT_SYMBOL(inet_sendmsg);
 838
 839 void inet_splice_eof(struct socket *sock)
 840 {
 841         const struct proto *prot;
 842         struct sock *sk = sock->sk;
 843
 844         if (unlikely(inet_send_prepare(sk)))
 845                 return;
 846
 847         /* IPV6_ADDRFORM can change sk->sk_prot under us. */
 848         prot = READ_ONCE(sk->sk_prot);
 849         if (prot->splice_eof)
 850                 prot->splice_eof(sock);
 851 }
 852 EXPORT_SYMBOL_GPL(inet_splice_eof);
 853
 854 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
 855                                           size_t, int, int *));
 856 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 857                  int flags)
 858 {
 859         struct sock *sk = sock->sk;
 860         int addr_len = 0;
 861         int err;
 862
 863         if (likely(!(flags & MSG_ERRQUEUE)))
 864                 sock_rps_record_flow(sk);
 865
 866         err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
 867                               sk, msg, size, flags, &addr_len);
 868         if (err >= 0)
 869                 msg->msg_namelen = addr_len;
 870         return err;
 871 }
 872 EXPORT_SYMBOL(inet_recvmsg);
 873
 874 int inet_shutdown(struct socket *sock, int how)
 875 {
 876         struct sock *sk = sock->sk;
 877         int err = 0;
 878
 879         /* This should really check to make sure
 880          * the socket is a TCP socket. (WHY AC...)
 881          */
 882         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 883                        1->2 bit 2 snds.
 884                        2->3 */
 885         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 886                 return -EINVAL;
 887
 888         lock_sock(sk);
 889         if (sock->state == SS_CONNECTING) {
 890                 if ((1 << sk->sk_state) &
 891                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 892                         sock->state = SS_DISCONNECTING;
 893                 else
 894                         sock->state = SS_CONNECTED;
 895         }
 896
 897         switch (sk->sk_state) {
 898         case TCP_CLOSE:
 899                 err = -ENOTCONN;
 900                 /* Hack to wake up other listeners, who can poll for
 901                    EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
 902                 fallthrough;
 903         default:
 904                 WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
 905                 if (sk->sk_prot->shutdown)
 906                         sk->sk_prot->shutdown(sk, how);
 907                 break;
 908
 909         /* Remaining two branches are temporary solution for missing
 910          * close() in multithreaded environment. It is _not_ a good idea,
 911          * but we have no choice until close() is repaired at VFS level.
 912          */
 913         case TCP_LISTEN:
 914                 if (!(how & RCV_SHUTDOWN))
 915                         break;
 916                 fallthrough;
 917         case TCP_SYN_SENT:
 918                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 919                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 920                 break;
 921         }
 922
 923         /* Wake up anyone sleeping in poll. */
 924         sk->sk_state_change(sk);
 925         release_sock(sk);
 926         return err;
 927 }
 928 EXPORT_SYMBOL(inet_shutdown);
 929
 930 /*
 931  *      ioctl() calls you can issue on an INET socket. Most of these are
 932  *      device configuration and stuff and very rarely used. Some ioctls
 933  *      pass on to the socket itself.
 934  *
 935  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 936  *      loads the devconfigure module does its configuring and unloads it.
 937  *      There's a good 20K of config code hanging around the kernel.
 938  */
 939
 940 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 941 {
 942         struct sock *sk = sock->sk;
 943         int err = 0;
 944         struct net *net = sock_net(sk);
 945         void __user *p = (void __user *)arg;
 946         struct ifreq ifr;
 947         struct rtentry rt;
 948
 949         switch (cmd) {
 950         case SIOCADDRT:
 951         case SIOCDELRT:
 952                 if (copy_from_user(&rt, p, sizeof(struct rtentry)))
 953                         return -EFAULT;
 954                 err = ip_rt_ioctl(net, cmd, &rt);
 955                 break;
 956         case SIOCRTMSG:
 957                 err = -EINVAL;
 958                 break;
 959         case SIOCDARP:
 960         case SIOCGARP:
 961         case SIOCSARP:
 962                 err = arp_ioctl(net, cmd, (void __user *)arg);
 963                 break;
 964         case SIOCGIFADDR:
 965         case SIOCGIFBRDADDR:
 966         case SIOCGIFNETMASK:
 967         case SIOCGIFDSTADDR:
 968         case SIOCGIFPFLAGS:
 969                 if (get_user_ifreq(&ifr, NULL, p))
 970                         return -EFAULT;
 971                 err = devinet_ioctl(net, cmd, &ifr);
 972                 if (!err && put_user_ifreq(&ifr, p))
 973                         err = -EFAULT;
 974                 break;
 975
 976         case SIOCSIFADDR:
 977         case SIOCSIFBRDADDR:
 978         case SIOCSIFNETMASK:
 979         case SIOCSIFDSTADDR:
 980         case SIOCSIFPFLAGS:
 981         case SIOCSIFFLAGS:
 982                 if (get_user_ifreq(&ifr, NULL, p))
 983                         return -EFAULT;
 984                 err = devinet_ioctl(net, cmd, &ifr);
 985                 break;
 986         default:
 987                 if (sk->sk_prot->ioctl)
 988                         err = sk_ioctl(sk, cmd, (void __user *)arg);
 989                 else
 990                         err = -ENOIOCTLCMD;
 991                 break;
 992         }
 993         return err;
 994 }
 995 EXPORT_SYMBOL(inet_ioctl);
 996
 997 #ifdef CONFIG_COMPAT
 998 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
 999                 struct compat_rtentry __user *ur)
1000 {
1001         compat_uptr_t rtdev;
1002         struct rtentry rt;
1003
1004         if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1005                         3 * sizeof(struct sockaddr)) ||
1006             get_user(rt.rt_flags, &ur->rt_flags) ||
1007             get_user(rt.rt_metric, &ur->rt_metric) ||
1008             get_user(rt.rt_mtu, &ur->rt_mtu) ||
1009             get_user(rt.rt_window, &ur->rt_window) ||
1010             get_user(rt.rt_irtt, &ur->rt_irtt) ||
1011             get_user(rtdev, &ur->rt_dev))
1012                 return -EFAULT;
1013
1014         rt.rt_dev = compat_ptr(rtdev);
1015         return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1016 }
1017
1018 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1019 {
1020         void __user *argp = compat_ptr(arg);
1021         struct sock *sk = sock->sk;
1022
1023         switch (cmd) {
1024         case SIOCADDRT:
1025         case SIOCDELRT:
1026                 return inet_compat_routing_ioctl(sk, cmd, argp);
1027         default:
1028                 if (!sk->sk_prot->compat_ioctl)
1029                         return -ENOIOCTLCMD;
1030                 return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1031         }
1032 }
1033 #endif /* CONFIG_COMPAT */
1034
1035 const struct proto_ops inet_stream_ops = {
1036         .family            = PF_INET,
1037         .owner             = THIS_MODULE,
1038         .release           = inet_release,
1039         .bind              = inet_bind,
1040         .connect           = inet_stream_connect,
1041         .socketpair        = sock_no_socketpair,
1042         .accept            = inet_accept,
1043         .getname           = inet_getname,
1044         .poll              = tcp_poll,
1045         .ioctl             = inet_ioctl,
1046         .gettstamp         = sock_gettstamp,
1047         .listen            = inet_listen,
1048         .shutdown          = inet_shutdown,
1049         .setsockopt        = sock_common_setsockopt,
1050         .getsockopt        = sock_common_getsockopt,
1051         .sendmsg           = inet_sendmsg,
1052         .recvmsg           = inet_recvmsg,
1053 #ifdef CONFIG_MMU
1054         .mmap              = tcp_mmap,
1055 #endif
1056         .splice_eof        = inet_splice_eof,
1057         .splice_read       = tcp_splice_read,
1058         .read_sock         = tcp_read_sock,
1059         .read_skb          = tcp_read_skb,
1060         .sendmsg_locked    = tcp_sendmsg_locked,
1061         .peek_len          = tcp_peek_len,
1062 #ifdef CONFIG_COMPAT
1063         .compat_ioctl      = inet_compat_ioctl,
1064 #endif
1065         .set_rcvlowat      = tcp_set_rcvlowat,
1066 };
1067 EXPORT_SYMBOL(inet_stream_ops);
1068
1069 const struct proto_ops inet_dgram_ops = {
1070         .family            = PF_INET,
1071         .owner             = THIS_MODULE,
1072         .release           = inet_release,
1073         .bind              = inet_bind,
1074         .connect           = inet_dgram_connect,
1075         .socketpair        = sock_no_socketpair,
1076         .accept            = sock_no_accept,
1077         .getname           = inet_getname,
1078         .poll              = udp_poll,
1079         .ioctl             = inet_ioctl,
1080         .gettstamp         = sock_gettstamp,
1081         .listen            = sock_no_listen,
1082         .shutdown          = inet_shutdown,
1083         .setsockopt        = sock_common_setsockopt,
1084         .getsockopt        = sock_common_getsockopt,
1085         .sendmsg           = inet_sendmsg,
1086         .read_skb          = udp_read_skb,
1087         .recvmsg           = inet_recvmsg,
1088         .mmap              = sock_no_mmap,
1089         .splice_eof        = inet_splice_eof,
1090         .set_peek_off      = sk_set_peek_off,
1091 #ifdef CONFIG_COMPAT
1092         .compat_ioctl      = inet_compat_ioctl,
1093 #endif
1094 };
1095 EXPORT_SYMBOL(inet_dgram_ops);
1096
1097 /*
1098  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1099  * udp_poll
1100  */
1101 static const struct proto_ops inet_sockraw_ops = {
1102         .family            = PF_INET,
1103         .owner             = THIS_MODULE,
1104         .release           = inet_release,
1105         .bind              = inet_bind,
1106         .connect           = inet_dgram_connect,
1107         .socketpair        = sock_no_socketpair,
1108         .accept            = sock_no_accept,
1109         .getname           = inet_getname,
1110         .poll              = datagram_poll,
1111         .ioctl             = inet_ioctl,
1112         .gettstamp         = sock_gettstamp,
1113         .listen            = sock_no_listen,
1114         .shutdown          = inet_shutdown,
1115         .setsockopt        = sock_common_setsockopt,
1116         .getsockopt        = sock_common_getsockopt,
1117         .sendmsg           = inet_sendmsg,
1118         .recvmsg           = inet_recvmsg,
1119         .mmap              = sock_no_mmap,
1120         .splice_eof        = inet_splice_eof,
1121 #ifdef CONFIG_COMPAT
1122         .compat_ioctl      = inet_compat_ioctl,
1123 #endif
1124 };
1125
1126 static const struct net_proto_family inet_family_ops = {
1127         .family = PF_INET,
1128         .create = inet_create,
1129         .owner  = THIS_MODULE,
1130 };
1131
1132 /* Upon startup we insert all the elements in inetsw_array[] into
1133  * the linked list inetsw.
1134  */
1135 static struct inet_protosw inetsw_array[] =
1136 {
1137         {
1138                 .type =       SOCK_STREAM,
1139                 .protocol =   IPPROTO_TCP,
1140                 .prot =       &tcp_prot,
1141                 .ops =        &inet_stream_ops,
1142                 .flags =      INET_PROTOSW_PERMANENT |
1143                               INET_PROTOSW_ICSK,
1144         },
1145
1146         {
1147                 .type =       SOCK_DGRAM,
1148                 .protocol =   IPPROTO_UDP,
1149                 .prot =       &udp_prot,
1150                 .ops =        &inet_dgram_ops,
1151                 .flags =      INET_PROTOSW_PERMANENT,
1152        },
1153
1154        {
1155                 .type =       SOCK_DGRAM,
1156                 .protocol =   IPPROTO_ICMP,
1157                 .prot =       &ping_prot,
1158                 .ops =        &inet_sockraw_ops,
1159                 .flags =      INET_PROTOSW_REUSE,
1160        },
1161
1162        {
1163                .type =       SOCK_RAW,
1164                .protocol =   IPPROTO_IP,        /* wild card */
1165                .prot =       &raw_prot,
1166                .ops =        &inet_sockraw_ops,
1167                .flags =      INET_PROTOSW_REUSE,
1168        }
1169 };
1170
1171 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1172
1173 void inet_register_protosw(struct inet_protosw *p)
1174 {
1175         struct list_head *lh;
1176         struct inet_protosw *answer;
1177         int protocol = p->protocol;
1178         struct list_head *last_perm;
1179
1180         spin_lock_bh(&inetsw_lock);
1181
1182         if (p->type >= SOCK_MAX)
1183                 goto out_illegal;
1184
1185         /* If we are trying to override a permanent protocol, bail. */
1186         last_perm = &inetsw[p->type];
1187         list_for_each(lh, &inetsw[p->type]) {
1188                 answer = list_entry(lh, struct inet_protosw, list);
1189                 /* Check only the non-wild match. */
1190                 if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1191                         break;
1192                 if (protocol == answer->protocol)
1193                         goto out_permanent;
1194                 last_perm = lh;
1195         }
1196
1197         /* Add the new entry after the last permanent entry if any, so that
1198          * the new entry does not override a permanent entry when matched with
1199          * a wild-card protocol. But it is allowed to override any existing
1200          * non-permanent entry.  This means that when we remove this entry, the
1201          * system automatically returns to the old behavior.
1202          */
1203         list_add_rcu(&p->list, last_perm);
1204 out:
1205         spin_unlock_bh(&inetsw_lock);
1206
1207         return;
1208
1209 out_permanent:
1210         pr_err("Attempt to override permanent protocol %d\n", protocol);
1211         goto out;
1212
1213 out_illegal:
1214         pr_err("Ignoring attempt to register invalid socket type %d\n",
1215                p->type);
1216         goto out;
1217 }
1218 EXPORT_SYMBOL(inet_register_protosw);
1219
1220 void inet_unregister_protosw(struct inet_protosw *p)
1221 {
1222         if (INET_PROTOSW_PERMANENT & p->flags) {
1223                 pr_err("Attempt to unregister permanent protocol %d\n",
1224                        p->protocol);
1225         } else {
1226                 spin_lock_bh(&inetsw_lock);
1227                 list_del_rcu(&p->list);
1228                 spin_unlock_bh(&inetsw_lock);
1229
1230                 synchronize_net();
1231         }
1232 }
1233 EXPORT_SYMBOL(inet_unregister_protosw);
1234
1235 static int inet_sk_reselect_saddr(struct sock *sk)
1236 {
1237         struct inet_sock *inet = inet_sk(sk);
1238         __be32 old_saddr = inet->inet_saddr;
1239         __be32 daddr = inet->inet_daddr;
1240         struct flowi4 *fl4;
1241         struct rtable *rt;
1242         __be32 new_saddr;
1243         struct ip_options_rcu *inet_opt;
1244         int err;
1245
1246         inet_opt = rcu_dereference_protected(inet->inet_opt,
1247                                              lockdep_sock_is_held(sk));
1248         if (inet_opt && inet_opt->opt.srr)
1249                 daddr = inet_opt->opt.faddr;
1250
1251         /* Query new route. */
1252         fl4 = &inet->cork.fl.u.ip4;
1253         rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1254                               sk->sk_protocol, inet->inet_sport,
1255                               inet->inet_dport, sk);
1256         if (IS_ERR(rt))
1257                 return PTR_ERR(rt);
1258
1259         new_saddr = fl4->saddr;
1260
1261         if (new_saddr == old_saddr) {
1262                 sk_setup_caps(sk, &rt->dst);
1263                 return 0;
1264         }
1265
1266         err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1267         if (err) {
1268                 ip_rt_put(rt);
1269                 return err;
1270         }
1271
1272         sk_setup_caps(sk, &rt->dst);
1273
1274         if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1275                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1276                         __func__, &old_saddr, &new_saddr);
1277         }
1278
1279         /*
1280          * XXX The only one ugly spot where we need to
1281          * XXX really change the sockets identity after
1282          * XXX it has entered the hashes. -DaveM
1283          *
1284          * Besides that, it does not check for connection
1285          * uniqueness. Wait for troubles.
1286          */
1287         return __sk_prot_rehash(sk);
1288 }
1289
1290 int inet_sk_rebuild_header(struct sock *sk)
1291 {
1292         struct inet_sock *inet = inet_sk(sk);
1293         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1294         __be32 daddr;
1295         struct ip_options_rcu *inet_opt;
1296         struct flowi4 *fl4;
1297         int err;
1298
1299         /* Route is OK, nothing to do. */
1300         if (rt)
1301                 return 0;
1302
1303         /* Reroute. */
1304         rcu_read_lock();
1305         inet_opt = rcu_dereference(inet->inet_opt);
1306         daddr = inet->inet_daddr;
1307         if (inet_opt && inet_opt->opt.srr)
1308                 daddr = inet_opt->opt.faddr;
1309         rcu_read_unlock();
1310         fl4 = &inet->cork.fl.u.ip4;
1311         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1312                                    inet->inet_dport, inet->inet_sport,
1313                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1314                                    sk->sk_bound_dev_if);
1315         if (!IS_ERR(rt)) {
1316                 err = 0;
1317                 sk_setup_caps(sk, &rt->dst);
1318         } else {
1319                 err = PTR_ERR(rt);
1320
1321                 /* Routing failed... */
1322                 sk->sk_route_caps = 0;
1323                 /*
1324                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1325                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1326                  */
1327                 if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1328                     sk->sk_state != TCP_SYN_SENT ||
1329                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1330                     (err = inet_sk_reselect_saddr(sk)) != 0)
1331                         WRITE_ONCE(sk->sk_err_soft, -err);
1332         }
1333
1334         return err;
1335 }
1336 EXPORT_SYMBOL(inet_sk_rebuild_header);
1337
1338 void inet_sk_set_state(struct sock *sk, int state)
1339 {
1340         trace_inet_sock_set_state(sk, sk->sk_state, state);
1341         sk->sk_state = state;
1342 }
1343 EXPORT_SYMBOL(inet_sk_set_state);
1344
1345 void inet_sk_state_store(struct sock *sk, int newstate)
1346 {
1347         trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1348         smp_store_release(&sk->sk_state, newstate);
1349 }
1350
1351 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1352                                  netdev_features_t features)
1353 {
1354         bool udpfrag = false, fixedid = false, gso_partial, encap;
1355         struct sk_buff *segs = ERR_PTR(-EINVAL);
1356         const struct net_offload *ops;
1357         unsigned int offset = 0;
1358         struct iphdr *iph;
1359         int proto, tot_len;
1360         int nhoff;
1361         int ihl;
1362         int id;
1363
1364         skb_reset_network_header(skb);
1365         nhoff = skb_network_header(skb) - skb_mac_header(skb);
1366         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1367                 goto out;
1368
1369         iph = ip_hdr(skb);
1370         ihl = iph->ihl * 4;
1371         if (ihl < sizeof(*iph))
1372                 goto out;
1373
1374         id = ntohs(iph->id);
1375         proto = iph->protocol;
1376
1377         /* Warning: after this point, iph might be no longer valid */
1378         if (unlikely(!pskb_may_pull(skb, ihl)))
1379                 goto out;
1380         __skb_pull(skb, ihl);
1381
1382         encap = SKB_GSO_CB(skb)->encap_level > 0;
1383         if (encap)
1384                 features &= skb->dev->hw_enc_features;
1385         SKB_GSO_CB(skb)->encap_level += ihl;
1386
1387         skb_reset_transport_header(skb);
1388
1389         segs = ERR_PTR(-EPROTONOSUPPORT);
1390
1391         if (!skb->encapsulation || encap) {
1392                 udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1393                 fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1394
1395                 /* fixed ID is invalid if DF bit is not set */
1396                 if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1397                         goto out;
1398         }
1399
1400         ops = rcu_dereference(inet_offloads[proto]);
1401         if (likely(ops && ops->callbacks.gso_segment)) {
1402                 segs = ops->callbacks.gso_segment(skb, features);
1403                 if (!segs)
1404                         skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1405         }
1406
1407         if (IS_ERR_OR_NULL(segs))
1408                 goto out;
1409
1410         gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1411
1412         skb = segs;
1413         do {
1414                 iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1415                 if (udpfrag) {
1416                         iph->frag_off = htons(offset >> 3);
1417                         if (skb->next)
1418                                 iph->frag_off |= htons(IP_MF);
1419                         offset += skb->len - nhoff - ihl;
1420                         tot_len = skb->len - nhoff;
1421                 } else if (skb_is_gso(skb)) {
1422                         if (!fixedid) {
1423                                 iph->id = htons(id);
1424                                 id += skb_shinfo(skb)->gso_segs;
1425                         }
1426
1427                         if (gso_partial)
1428                                 tot_len = skb_shinfo(skb)->gso_size +
1429                                           SKB_GSO_CB(skb)->data_offset +
1430                                           skb->head - (unsigned char *)iph;
1431                         else
1432                                 tot_len = skb->len - nhoff;
1433                 } else {
1434                         if (!fixedid)
1435                                 iph->id = htons(id++);
1436                         tot_len = skb->len - nhoff;
1437                 }
1438                 iph->tot_len = htons(tot_len);
1439                 ip_send_check(iph);
1440                 if (encap)
1441                         skb_reset_inner_headers(skb);
1442                 skb->network_header = (u8 *)iph - skb->head;
1443                 skb_reset_mac_len(skb);
1444         } while ((skb = skb->next));
1445
1446 out:
1447         return segs;
1448 }
1449
1450 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1451                                         netdev_features_t features)
1452 {
1453         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1454                 return ERR_PTR(-EINVAL);
1455
1456         return inet_gso_segment(skb, features);
1457 }
1458
1459 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1460 {
1461         const struct net_offload *ops;
1462         struct sk_buff *pp = NULL;
1463         const struct iphdr *iph;
1464         struct sk_buff *p;
1465         unsigned int hlen;
1466         unsigned int off;
1467         unsigned int id;
1468         int flush = 1;
1469         int proto;
1470
1471         off = skb_gro_offset(skb);
1472         hlen = off + sizeof(*iph);
1473         iph = skb_gro_header(skb, hlen, off);
1474         if (unlikely(!iph))
1475                 goto out;
1476
1477         proto = iph->protocol;
1478
1479         ops = rcu_dereference(inet_offloads[proto]);
1480         if (!ops || !ops->callbacks.gro_receive)
1481                 goto out;
1482
1483         if (*(u8 *)iph != 0x45)
1484                 goto out;
1485
1486         if (ip_is_fragment(iph))
1487                 goto out;
1488
1489         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1490                 goto out;
1491
1492         NAPI_GRO_CB(skb)->proto = proto;
1493         id = ntohl(*(__be32 *)&iph->id);
1494         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1495         id >>= 16;
1496
1497         list_for_each_entry(p, head, list) {
1498                 struct iphdr *iph2;
1499                 u16 flush_id;
1500
1501                 if (!NAPI_GRO_CB(p)->same_flow)
1502                         continue;
1503
1504                 iph2 = (struct iphdr *)(p->data + off);
1505                 /* The above works because, with the exception of the top
1506                  * (inner most) layer, we only aggregate pkts with the same
1507                  * hdr length so all the hdrs we'll need to verify will start
1508                  * at the same offset.
1509                  */
1510                 if ((iph->protocol ^ iph2->protocol) |
1511                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1512                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1513                         NAPI_GRO_CB(p)->same_flow = 0;
1514                         continue;
1515                 }
1516
1517                 /* All fields must match except length and checksum. */
1518                 NAPI_GRO_CB(p)->flush |=
1519                         (iph->ttl ^ iph2->ttl) |
1520                         (iph->tos ^ iph2->tos) |
1521                         ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1522
1523                 NAPI_GRO_CB(p)->flush |= flush;
1524
1525                 /* We need to store of the IP ID check to be included later
1526                  * when we can verify that this packet does in fact belong
1527                  * to a given flow.
1528                  */
1529                 flush_id = (u16)(id - ntohs(iph2->id));
1530
1531                 /* This bit of code makes it much easier for us to identify
1532                  * the cases where we are doing atomic vs non-atomic IP ID
1533                  * checks.  Specifically an atomic check can return IP ID
1534                  * values 0 - 0xFFFF, while a non-atomic check can only
1535                  * return 0 or 0xFFFF.
1536                  */
1537                 if (!NAPI_GRO_CB(p)->is_atomic ||
1538                     !(iph->frag_off & htons(IP_DF))) {
1539                         flush_id ^= NAPI_GRO_CB(p)->count;
1540                         flush_id = flush_id ? 0xFFFF : 0;
1541                 }
1542
1543                 /* If the previous IP ID value was based on an atomic
1544                  * datagram we can overwrite the value and ignore it.
1545                  */
1546                 if (NAPI_GRO_CB(skb)->is_atomic)
1547                         NAPI_GRO_CB(p)->flush_id = flush_id;
1548                 else
1549                         NAPI_GRO_CB(p)->flush_id |= flush_id;
1550         }
1551
1552         NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1553         NAPI_GRO_CB(skb)->flush |= flush;
1554         skb_set_network_header(skb, off);
1555         /* The above will be needed by the transport layer if there is one
1556          * immediately following this IP hdr.
1557          */
1558
1559         /* Note : No need to call skb_gro_postpull_rcsum() here,
1560          * as we already checked checksum over ipv4 header was 0
1561          */
1562         skb_gro_pull(skb, sizeof(*iph));
1563         skb_set_transport_header(skb, skb_gro_offset(skb));
1564
1565         pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1566                                        ops->callbacks.gro_receive, head, skb);
1567
1568 out:
1569         skb_gro_flush_final(skb, pp, flush);
1570
1571         return pp;
1572 }
1573
1574 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1575                                         struct sk_buff *skb)
1576 {
1577         if (NAPI_GRO_CB(skb)->encap_mark) {
1578                 NAPI_GRO_CB(skb)->flush = 1;
1579                 return NULL;
1580         }
1581
1582         NAPI_GRO_CB(skb)->encap_mark = 1;
1583
1584         return inet_gro_receive(head, skb);
1585 }
1586
1587 #define SECONDS_PER_DAY 86400
1588
1589 /* inet_current_timestamp - Return IP network timestamp
1590  *
1591  * Return milliseconds since midnight in network byte order.
1592  */
1593 __be32 inet_current_timestamp(void)
1594 {
1595         u32 secs;
1596         u32 msecs;
1597         struct timespec64 ts;
1598
1599         ktime_get_real_ts64(&ts);
1600
1601         /* Get secs since midnight. */
1602         (void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1603         /* Convert to msecs. */
1604         msecs = secs * MSEC_PER_SEC;
1605         /* Convert nsec to msec. */
1606         msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1607
1608         /* Convert to network byte order. */
1609         return htonl(msecs);
1610 }
1611 EXPORT_SYMBOL(inet_current_timestamp);
1612
1613 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1614 {
1615         if (sk->sk_family == AF_INET)
1616                 return ip_recv_error(sk, msg, len, addr_len);
1617 #if IS_ENABLED(CONFIG_IPV6)
1618         if (sk->sk_family == AF_INET6)
1619                 return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1620 #endif
1621         return -EINVAL;
1622 }
1623
1624 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1625 {
1626         struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1627         const struct net_offload *ops;
1628         __be16 totlen = iph->tot_len;
1629         int proto = iph->protocol;
1630         int err = -ENOSYS;
1631
1632         if (skb->encapsulation) {
1633                 skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1634                 skb_set_inner_network_header(skb, nhoff);
1635         }
1636
1637         iph_set_totlen(iph, skb->len - nhoff);
1638         csum_replace2(&iph->check, totlen, iph->tot_len);
1639
1640         ops = rcu_dereference(inet_offloads[proto]);
1641         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1642                 goto out;
1643
1644         /* Only need to add sizeof(*iph) to get to the next hdr below
1645          * because any hdr with option will have been flushed in
1646          * inet_gro_receive().
1647          */
1648         err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1649                               tcp4_gro_complete, udp4_gro_complete,
1650                               skb, nhoff + sizeof(*iph));
1651
1652 out:
1653         return err;
1654 }
1655
1656 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1657 {
1658         skb->encapsulation = 1;
1659         skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1660         return inet_gro_complete(skb, nhoff);
1661 }
1662
1663 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1664                          unsigned short type, unsigned char protocol,
1665                          struct net *net)
1666 {
1667         struct socket *sock;
1668         int rc = sock_create_kern(net, family, type, protocol, &sock);
1669
1670         if (rc == 0) {
1671                 *sk = sock->sk;
1672                 (*sk)->sk_allocation = GFP_ATOMIC;
1673                 (*sk)->sk_use_task_frag = false;
1674                 /*
1675                  * Unhash it so that IP input processing does not even see it,
1676                  * we do not wish this socket to see incoming packets.
1677                  */
1678                 (*sk)->sk_prot->unhash(*sk);
1679         }
1680         return rc;
1681 }
1682 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1683
1684 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1685 {
1686         unsigned long res = 0;
1687         int i;
1688
1689         for_each_possible_cpu(i)
1690                 res += snmp_get_cpu_field(mib, i, offt);
1691         return res;
1692 }
1693 EXPORT_SYMBOL_GPL(snmp_fold_field);
1694
1695 #if BITS_PER_LONG==32
1696
1697 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1698                          size_t syncp_offset)
1699 {
1700         void *bhptr;
1701         struct u64_stats_sync *syncp;
1702         u64 v;
1703         unsigned int start;
1704
1705         bhptr = per_cpu_ptr(mib, cpu);
1706         syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1707         do {
1708                 start = u64_stats_fetch_begin(syncp);
1709                 v = *(((u64 *)bhptr) + offt);
1710         } while (u64_stats_fetch_retry(syncp, start));
1711
1712         return v;
1713 }
1714 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1715
1716 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1717 {
1718         u64 res = 0;
1719         int cpu;
1720
1721         for_each_possible_cpu(cpu) {
1722                 res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1723         }
1724         return res;
1725 }
1726 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1727 #endif
1728
1729 #ifdef CONFIG_IP_MULTICAST
1730 static const struct net_protocol igmp_protocol = {
1731         .handler =      igmp_rcv,
1732 };
1733 #endif
1734
1735 static const struct net_protocol tcp_protocol = {
1736         .handler        =       tcp_v4_rcv,
1737         .err_handler    =       tcp_v4_err,
1738         .no_policy      =       1,
1739         .icmp_strict_tag_validation = 1,
1740 };
1741
1742 static const struct net_protocol udp_protocol = {
1743         .handler =      udp_rcv,
1744         .err_handler =  udp_err,
1745         .no_policy =    1,
1746 };
1747
1748 static const struct net_protocol icmp_protocol = {
1749         .handler =      icmp_rcv,
1750         .err_handler =  icmp_err,
1751         .no_policy =    1,
1752 };
1753
1754 static __net_init int ipv4_mib_init_net(struct net *net)
1755 {
1756         int i;
1757
1758         net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1759         if (!net->mib.tcp_statistics)
1760                 goto err_tcp_mib;
1761         net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1762         if (!net->mib.ip_statistics)
1763                 goto err_ip_mib;
1764
1765         for_each_possible_cpu(i) {
1766                 struct ipstats_mib *af_inet_stats;
1767                 af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1768                 u64_stats_init(&af_inet_stats->syncp);
1769         }
1770
1771         net->mib.net_statistics = alloc_percpu(struct linux_mib);
1772         if (!net->mib.net_statistics)
1773                 goto err_net_mib;
1774         net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1775         if (!net->mib.udp_statistics)
1776                 goto err_udp_mib;
1777         net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1778         if (!net->mib.udplite_statistics)
1779                 goto err_udplite_mib;
1780         net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1781         if (!net->mib.icmp_statistics)
1782                 goto err_icmp_mib;
1783         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1784                                               GFP_KERNEL);
1785         if (!net->mib.icmpmsg_statistics)
1786                 goto err_icmpmsg_mib;
1787
1788         tcp_mib_init(net);
1789         return 0;
1790
1791 err_icmpmsg_mib:
1792         free_percpu(net->mib.icmp_statistics);
1793 err_icmp_mib:
1794         free_percpu(net->mib.udplite_statistics);
1795 err_udplite_mib:
1796         free_percpu(net->mib.udp_statistics);
1797 err_udp_mib:
1798         free_percpu(net->mib.net_statistics);
1799 err_net_mib:
1800         free_percpu(net->mib.ip_statistics);
1801 err_ip_mib:
1802         free_percpu(net->mib.tcp_statistics);
1803 err_tcp_mib:
1804         return -ENOMEM;
1805 }
1806
1807 static __net_exit void ipv4_mib_exit_net(struct net *net)
1808 {
1809         kfree(net->mib.icmpmsg_statistics);
1810         free_percpu(net->mib.icmp_statistics);
1811         free_percpu(net->mib.udplite_statistics);
1812         free_percpu(net->mib.udp_statistics);
1813         free_percpu(net->mib.net_statistics);
1814         free_percpu(net->mib.ip_statistics);
1815         free_percpu(net->mib.tcp_statistics);
1816 #ifdef CONFIG_MPTCP
1817         /* allocated on demand, see mptcp_init_sock() */
1818         free_percpu(net->mib.mptcp_statistics);
1819 #endif
1820 }
1821
1822 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1823         .init = ipv4_mib_init_net,
1824         .exit = ipv4_mib_exit_net,
1825 };
1826
1827 static int __init init_ipv4_mibs(void)
1828 {
1829         return register_pernet_subsys(&ipv4_mib_ops);
1830 }
1831
1832 static __net_init int inet_init_net(struct net *net)
1833 {
1834         /*
1835          * Set defaults for local port range
1836          */
1837         seqlock_init(&net->ipv4.ip_local_ports.lock);
1838         net->ipv4.ip_local_ports.range[0] =  32768;
1839         net->ipv4.ip_local_ports.range[1] =  60999;
1840
1841         seqlock_init(&net->ipv4.ping_group_range.lock);
1842         /*
1843          * Sane defaults - nobody may create ping sockets.
1844          * Boot scripts should set this to distro-specific group.
1845          */
1846         net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1847         net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1848
1849         /* Default values for sysctl-controlled parameters.
1850          * We set them here, in case sysctl is not compiled.
1851          */
1852         net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1853         net->ipv4.sysctl_ip_fwd_update_priority = 1;
1854         net->ipv4.sysctl_ip_dynaddr = 0;
1855         net->ipv4.sysctl_ip_early_demux = 1;
1856         net->ipv4.sysctl_udp_early_demux = 1;
1857         net->ipv4.sysctl_tcp_early_demux = 1;
1858         net->ipv4.sysctl_nexthop_compat_mode = 1;
1859 #ifdef CONFIG_SYSCTL
1860         net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1861 #endif
1862
1863         /* Some igmp sysctl, whose values are always used */
1864         net->ipv4.sysctl_igmp_max_memberships = 20;
1865         net->ipv4.sysctl_igmp_max_msf = 10;
1866         /* IGMP reports for link-local multicast groups are enabled by default */
1867         net->ipv4.sysctl_igmp_llm_reports = 1;
1868         net->ipv4.sysctl_igmp_qrv = 2;
1869
1870         net->ipv4.sysctl_fib_notify_on_flag_change = 0;
1871
1872         return 0;
1873 }
1874
1875 static __net_initdata struct pernet_operations af_inet_ops = {
1876         .init = inet_init_net,
1877 };
1878
1879 static int __init init_inet_pernet_ops(void)
1880 {
1881         return register_pernet_subsys(&af_inet_ops);
1882 }
1883
1884 static int ipv4_proc_init(void);
1885
1886 /*
1887  *      IP protocol layer initialiser
1888  */
1889
1890 static struct packet_offload ip_packet_offload __read_mostly = {
1891         .type = cpu_to_be16(ETH_P_IP),
1892         .callbacks = {
1893                 .gso_segment = inet_gso_segment,
1894                 .gro_receive = inet_gro_receive,
1895                 .gro_complete = inet_gro_complete,
1896         },
1897 };
1898
1899 static const struct net_offload ipip_offload = {
1900         .callbacks = {
1901                 .gso_segment    = ipip_gso_segment,
1902                 .gro_receive    = ipip_gro_receive,
1903                 .gro_complete   = ipip_gro_complete,
1904         },
1905 };
1906
1907 static int __init ipip_offload_init(void)
1908 {
1909         return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1910 }
1911
1912 static int __init ipv4_offload_init(void)
1913 {
1914         /*
1915          * Add offloads
1916          */
1917         if (udpv4_offload_init() < 0)
1918                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1919         if (tcpv4_offload_init() < 0)
1920                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1921         if (ipip_offload_init() < 0)
1922                 pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1923
1924         dev_add_offload(&ip_packet_offload);
1925         return 0;
1926 }
1927
1928 fs_initcall(ipv4_offload_init);
1929
1930 static struct packet_type ip_packet_type __read_mostly = {
1931         .type = cpu_to_be16(ETH_P_IP),
1932         .func = ip_rcv,
1933         .list_func = ip_list_rcv,
1934 };
1935
1936 static int __init inet_init(void)
1937 {
1938         struct inet_protosw *q;
1939         struct list_head *r;
1940         int rc;
1941
1942         sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1943
1944         raw_hashinfo_init(&raw_v4_hashinfo);
1945
1946         rc = proto_register(&tcp_prot, 1);
1947         if (rc)
1948                 goto out;
1949
1950         rc = proto_register(&udp_prot, 1);
1951         if (rc)
1952                 goto out_unregister_tcp_proto;
1953
1954         rc = proto_register(&raw_prot, 1);
1955         if (rc)
1956                 goto out_unregister_udp_proto;
1957
1958         rc = proto_register(&ping_prot, 1);
1959         if (rc)
1960                 goto out_unregister_raw_proto;
1961
1962         /*
1963          *      Tell SOCKET that we are alive...
1964          */
1965
1966         (void)sock_register(&inet_family_ops);
1967
1968 #ifdef CONFIG_SYSCTL
1969         ip_static_sysctl_init();
1970 #endif
1971
1972         /*
1973          *      Add all the base protocols.
1974          */
1975
1976         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1977                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1978         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1979                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1980         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1981                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1982 #ifdef CONFIG_IP_MULTICAST
1983         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1984                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1985 #endif
1986
1987         /* Register the socket-side information for inet_create. */
1988         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1989                 INIT_LIST_HEAD(r);
1990
1991         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1992                 inet_register_protosw(q);
1993
1994         /*
1995          *      Set the ARP module up
1996          */
1997
1998         arp_init();
1999
2000         /*
2001          *      Set the IP module up
2002          */
2003
2004         ip_init();
2005
2006         /* Initialise per-cpu ipv4 mibs */
2007         if (init_ipv4_mibs())
2008                 panic("%s: Cannot init ipv4 mibs\n", __func__);
2009
2010         /* Setup TCP slab cache for open requests. */
2011         tcp_init();
2012
2013         /* Setup UDP memory threshold */
2014         udp_init();
2015
2016         /* Add UDP-Lite (RFC 3828) */
2017         udplite4_register();
2018
2019         raw_init();
2020
2021         ping_init();
2022
2023         /*
2024          *      Set the ICMP layer up
2025          */
2026
2027         if (icmp_init() < 0)
2028                 panic("Failed to create the ICMP control socket.\n");
2029
2030         /*
2031          *      Initialise the multicast router
2032          */
2033 #if defined(CONFIG_IP_MROUTE)
2034         if (ip_mr_init())
2035                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2036 #endif
2037
2038         if (init_inet_pernet_ops())
2039                 pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2040
2041         ipv4_proc_init();
2042
2043         ipfrag_init();
2044
2045         dev_add_pack(&ip_packet_type);
2046
2047         ip_tunnel_core_init();
2048
2049         rc = 0;
2050 out:
2051         return rc;
2052 out_unregister_raw_proto:
2053         proto_unregister(&raw_prot);
2054 out_unregister_udp_proto:
2055         proto_unregister(&udp_prot);
2056 out_unregister_tcp_proto:
2057         proto_unregister(&tcp_prot);
2058         goto out;
2059 }
2060
2061 fs_initcall(inet_init);
2062
2063 /* ------------------------------------------------------------------------ */
2064
2065 #ifdef CONFIG_PROC_FS
2066 static int __init ipv4_proc_init(void)
2067 {
2068         int rc = 0;
2069
2070         if (raw_proc_init())
2071                 goto out_raw;
2072         if (tcp4_proc_init())
2073                 goto out_tcp;
2074         if (udp4_proc_init())
2075                 goto out_udp;
2076         if (ping_proc_init())
2077                 goto out_ping;
2078         if (ip_misc_proc_init())
2079                 goto out_misc;
2080 out:
2081         return rc;
2082 out_misc:
2083         ping_proc_exit();
2084 out_ping:
2085         udp4_proc_exit();
2086 out_udp:
2087         tcp4_proc_exit();
2088 out_tcp:
2089         raw_proc_exit();
2090 out_raw:
2091         rc = -ENOMEM;
2092         goto out;
2093 }
2094
2095 #else /* CONFIG_PROC_FS */
2096 static int __init ipv4_proc_init(void)
2097 {
2098         return 0;
2099 }
2100 #endif /* CONFIG_PROC_FS */