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/tcp.h>
 104 #include <net/udp.h>
 105 #include <net/udplite.h>
 106 #include <net/ping.h>
 107 #include <linux/skbuff.h>
 108 #include <net/sock.h>
 109 #include <net/raw.h>
 110 #include <net/icmp.h>
 111 #include <net/inet_common.h>
 112 #include <net/ip_tunnels.h>
 113 #include <net/xfrm.h>
 114 #include <net/net_namespace.h>
 115 #include <net/secure_seq.h>
 116 #ifdef CONFIG_IP_MROUTE
 117 #include <linux/mroute.h>
 118 #endif
 119 #include <net/l3mdev.h>
 120 #include <net/compat.h>
 121
 122 #include <trace/events/sock.h>
 123
 124 /* The inetsw table contains everything that inet_create needs to
 125  * build a new socket.
 126  */
 127 static struct list_head inetsw[SOCK_MAX];
 128 static DEFINE_SPINLOCK(inetsw_lock);
 129
 130 /* New destruction routine */
 131
 132 void inet_sock_destruct(struct sock *sk)
 133 {
 134         struct inet_sock *inet = inet_sk(sk);
 135
 136         __skb_queue_purge(&sk->sk_receive_queue);
 137         __skb_queue_purge(&sk->sk_error_queue);
 138
 139         sk_mem_reclaim_final(sk);
 140
 141         if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
 142                 pr_err("Attempt to release TCP socket in state %d %p\n",
 143                        sk->sk_state, sk);
 144                 return;
 145         }
 146         if (!sock_flag(sk, SOCK_DEAD)) {
 147                 pr_err("Attempt to release alive inet socket %p\n", sk);
 148                 return;
 149         }
 150
 151         WARN_ON_ONCE(atomic_read(&sk->sk_rmem_alloc));
 152         WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc));
 153         WARN_ON_ONCE(sk->sk_wmem_queued);
 154         WARN_ON_ONCE(sk_forward_alloc_get(sk));
 155
 156         kfree(rcu_dereference_protected(inet->inet_opt, 1));
 157         dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
 158         dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
 159 }
 160 EXPORT_SYMBOL(inet_sock_destruct);
 161
 162 /*
 163  *      The routines beyond this point handle the behaviour of an AF_INET
 164  *      socket object. Mostly it punts to the subprotocols of IP to do
 165  *      the work.
 166  */
 167
 168 /*
 169  *      Automatically bind an unbound socket.
 170  */
 171
 172 static int inet_autobind(struct sock *sk)
 173 {
 174         struct inet_sock *inet;
 175         /* We may need to bind the socket. */
 176         lock_sock(sk);
 177         inet = inet_sk(sk);
 178         if (!inet->inet_num) {
 179                 if (sk->sk_prot->get_port(sk, 0)) {
 180                         release_sock(sk);
 181                         return -EAGAIN;
 182                 }
 183                 inet->inet_sport = htons(inet->inet_num);
 184         }
 185         release_sock(sk);
 186         return 0;
 187 }
 188
 189 /*
 190  *      Move a socket into listening state.
 191  */
 192 int inet_listen(struct socket *sock, int backlog)
 193 {
 194         struct sock *sk = sock->sk;
 195         unsigned char old_state;
 196         int err, tcp_fastopen;
 197
 198         lock_sock(sk);
 199
 200         err = -EINVAL;
 201         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
 202                 goto out;
 203
 204         old_state = sk->sk_state;
 205         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 206                 goto out;
 207
 208         WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
 209         /* Really, if the socket is already in listen state
 210          * we can only allow the backlog to be adjusted.
 211          */
 212         if (old_state != TCP_LISTEN) {
 213                 /* Enable TFO w/o requiring TCP_FASTOPEN socket option.
 214                  * Note that only TCP sockets (SOCK_STREAM) will reach here.
 215                  * Also fastopen backlog may already been set via the option
 216                  * because the socket was in TCP_LISTEN state previously but
 217                  * was shutdown() rather than close().
 218                  */
 219                 tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
 220                 if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
 221                     (tcp_fastopen & TFO_SERVER_ENABLE) &&
 222                     !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
 223                         fastopen_queue_tune(sk, backlog);
 224                         tcp_fastopen_init_key_once(sock_net(sk));
 225                 }
 226
 227                 err = inet_csk_listen_start(sk);
 228                 if (err)
 229                         goto out;
 230                 tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
 231         }
 232         err = 0;
 233
 234 out:
 235         release_sock(sk);
 236         return err;
 237 }
 238 EXPORT_SYMBOL(inet_listen);
 239
 240 /*
 241  *      Create an inet socket.
 242  */
 243
 244 static int inet_create(struct net *net, struct socket *sock, int protocol,
 245                        int kern)
 246 {
 247         struct sock *sk;
 248         struct inet_protosw *answer;
 249         struct inet_sock *inet;
 250         struct proto *answer_prot;
 251         unsigned char answer_flags;
 252         int try_loading_module = 0;
 253         int err;
 254
 255         if (protocol < 0 || protocol >= IPPROTO_MAX)
 256                 return -EINVAL;
 257
 258         sock->state = SS_UNCONNECTED;
 259
 260         /* Look for the requested type/protocol pair. */
 261 lookup_protocol:
 262         err = -ESOCKTNOSUPPORT;
 263         rcu_read_lock();
 264         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 265
 266                 err = 0;
 267                 /* Check the non-wild match. */
 268                 if (protocol == answer->protocol) {
 269                         if (protocol != IPPROTO_IP)
 270                                 break;
 271                 } else {
 272                         /* Check for the two wild cases. */
 273                         if (IPPROTO_IP == protocol) {
 274                                 protocol = answer->protocol;
 275                                 break;
 276                         }
 277                         if (IPPROTO_IP == answer->protocol)
 278                                 break;
 279                 }
 280                 err = -EPROTONOSUPPORT;
 281         }
 282
 283         if (unlikely(err)) {
 284                 if (try_loading_module < 2) {
 285                         rcu_read_unlock();
 286                         /*
 287                          * Be more specific, e.g. net-pf-2-proto-132-type-1
 288                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 289                          */
 290                         if (++try_loading_module == 1)
 291                                 request_module("net-pf-%d-proto-%d-type-%d",
 292                                                PF_INET, protocol, sock->type);
 293                         /*
 294                          * Fall back to generic, e.g. net-pf-2-proto-132
 295                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 296                          */
 297                         else
 298                                 request_module("net-pf-%d-proto-%d",
 299                                                PF_INET, protocol);
 300                         goto lookup_protocol;
 301                 } else
 302                         goto out_rcu_unlock;
 303         }
 304
 305         err = -EPERM;
 306         if (sock->type == SOCK_RAW && !kern &&
 307             !ns_capable(net->user_ns, CAP_NET_RAW))
 308                 goto out_rcu_unlock;
 309
 310         sock->ops = answer->ops;
 311         answer_prot = answer->prot;
 312         answer_flags = answer->flags;
 313         rcu_read_unlock();
 314
 315         WARN_ON(!answer_prot->slab);
 316
 317         err = -ENOMEM;
 318         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
 319         if (!sk)
 320                 goto out;
 321
 322         err = 0;
 323         if (INET_PROTOSW_REUSE & answer_flags)
 324                 sk->sk_reuse = SK_CAN_REUSE;
 325
 326         inet = inet_sk(sk);
 327         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 328
 329         inet->nodefrag = 0;
 330
 331         if (SOCK_RAW == sock->type) {
 332                 inet->inet_num = protocol;
 333                 if (IPPROTO_RAW == protocol)
 334                         inet->hdrincl = 1;
 335         }
 336
 337         if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
 338                 inet->pmtudisc = IP_PMTUDISC_DONT;
 339         else
 340                 inet->pmtudisc = IP_PMTUDISC_WANT;
 341
 342         inet->inet_id = 0;
 343
 344         sock_init_data(sock, sk);
 345
 346         sk->sk_destruct    = inet_sock_destruct;
 347         sk->sk_protocol    = protocol;
 348         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 349         sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
 350
 351         inet->uc_ttl    = -1;
 352         inet->mc_loop   = 1;
 353         inet->mc_ttl    = 1;
 354         inet->mc_all    = 1;
 355         inet->mc_index  = 0;
 356         inet->mc_list   = NULL;
 357         inet->rcv_tos   = 0;
 358
 359         if (inet->inet_num) {
 360                 /* It assumes that any protocol which allows
 361                  * the user to assign a number at socket
 362                  * creation time automatically
 363                  * shares.
 364                  */
 365                 inet->inet_sport = htons(inet->inet_num);
 366                 /* Add to protocol hash chains. */
 367                 err = sk->sk_prot->hash(sk);
 368                 if (err) {
 369                         sk_common_release(sk);
 370                         goto out;
 371                 }
 372         }
 373
 374         if (sk->sk_prot->init) {
 375                 err = sk->sk_prot->init(sk);
 376                 if (err) {
 377                         sk_common_release(sk);
 378                         goto out;
 379                 }
 380         }
 381
 382         if (!kern) {
 383                 err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
 384                 if (err) {
 385                         sk_common_release(sk);
 386                         goto out;
 387                 }
 388         }
 389 out:
 390         return err;
 391 out_rcu_unlock:
 392         rcu_read_unlock();
 393         goto out;
 394 }
 395
 396
 397 /*
 398  *      The peer socket should always be NULL (or else). When we call this
 399  *      function we are destroying the object and from then on nobody
 400  *      should refer to it.
 401  */
 402 int inet_release(struct socket *sock)
 403 {
 404         struct sock *sk = sock->sk;
 405
 406         if (sk) {
 407                 long timeout;
 408
 409                 if (!sk->sk_kern_sock)
 410                         BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
 411
 412                 /* Applications forget to leave groups before exiting */
 413                 ip_mc_drop_socket(sk);
 414
 415                 /* If linger is set, we don't return until the close
 416                  * is complete.  Otherwise we return immediately. The
 417                  * actually closing is done the same either way.
 418                  *
 419                  * If the close is due to the process exiting, we never
 420                  * linger..
 421                  */
 422                 timeout = 0;
 423                 if (sock_flag(sk, SOCK_LINGER) &&
 424                     !(current->flags & PF_EXITING))
 425                         timeout = sk->sk_lingertime;
 426                 sk->sk_prot->close(sk, timeout);
 427                 sock->sk = NULL;
 428         }
 429         return 0;
 430 }
 431 EXPORT_SYMBOL(inet_release);
 432
 433 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 434 {
 435         struct sock *sk = sock->sk;
 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 EXPORT_SYMBOL(inet_bind);
 457
 458 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
 459                 u32 flags)
 460 {
 461         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 462         struct inet_sock *inet = inet_sk(sk);
 463         struct net *net = sock_net(sk);
 464         unsigned short snum;
 465         int chk_addr_ret;
 466         u32 tb_id = RT_TABLE_LOCAL;
 467         int err;
 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         tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
 480         chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
 481
 482         /* Not specified by any standard per-se, however it breaks too
 483          * many applications when removed.  It is unfortunate since
 484          * allowing applications to make a non-local bind solves
 485          * several problems with systems using dynamic addressing.
 486          * (ie. your servers still start up even if your ISDN link
 487          *  is temporarily down)
 488          */
 489         err = -EADDRNOTAVAIL;
 490         if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,
 491                                          chk_addr_ret))
 492                 goto out;
 493
 494         snum = ntohs(addr->sin_port);
 495         err = -EACCES;
 496         if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
 497             snum && inet_port_requires_bind_service(net, snum) &&
 498             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
 499                 goto out;
 500
 501         /*      We keep a pair of addresses. rcv_saddr is the one
 502          *      used by hash lookups, and saddr is used for transmit.
 503          *
 504          *      In the BSD API these are the same except where it
 505          *      would be illegal to use them (multicast/broadcast) in
 506          *      which case the sending device address is used.
 507          */
 508         if (flags & BIND_WITH_LOCK)
 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 (snum || !(inet->bind_address_no_port ||
 522                       (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
 523                 err = sk->sk_prot->get_port(sk, snum);
 524                 if (err) {
 525                         inet->inet_saddr = inet->inet_rcv_saddr = 0;
 526                         goto out_release_sock;
 527                 }
 528                 if (!(flags & BIND_FROM_BPF)) {
 529                         err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
 530                         if (err) {
 531                                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
 532                                 if (sk->sk_prot->put_port)
 533                                         sk->sk_prot->put_port(sk);
 534                                 goto out_release_sock;
 535                         }
 536                 }
 537         }
 538
 539         if (inet->inet_rcv_saddr)
 540                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 541         if (snum)
 542                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 543         inet->inet_sport = htons(inet->inet_num);
 544         inet->inet_daddr = 0;
 545         inet->inet_dport = 0;
 546         sk_dst_reset(sk);
 547         err = 0;
 548 out_release_sock:
 549         if (flags & BIND_WITH_LOCK)
 550                 release_sock(sk);
 551 out:
 552         return err;
 553 }
 554
 555 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 556                        int addr_len, int flags)
 557 {
 558         struct sock *sk = sock->sk;
 559         const struct proto *prot;
 560         int err;
 561
 562         if (addr_len < sizeof(uaddr->sa_family))
 563                 return -EINVAL;
 564
 565         /* IPV6_ADDRFORM can change sk->sk_prot under us. */
 566         prot = READ_ONCE(sk->sk_prot);
 567
 568         if (uaddr->sa_family == AF_UNSPEC)
 569                 return prot->disconnect(sk, flags);
 570
 571         if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
 572                 err = prot->pre_connect(sk, uaddr, addr_len);
 573                 if (err)
 574                         return err;
 575         }
 576
 577         if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
 578                 return -EAGAIN;
 579         return prot->connect(sk, uaddr, addr_len);
 580 }
 581 EXPORT_SYMBOL(inet_dgram_connect);
 582
 583 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
 584 {
 585         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 586
 587         add_wait_queue(sk_sleep(sk), &wait);
 588         sk->sk_write_pending += writebias;
 589         sk->sk_wait_pending++;
 590
 591         /* Basic assumption: if someone sets sk->sk_err, he _must_
 592          * change state of the socket from TCP_SYN_*.
 593          * Connect() does not allow to get error notifications
 594          * without closing the socket.
 595          */
 596         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 597                 release_sock(sk);
 598                 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
 599                 lock_sock(sk);
 600                 if (signal_pending(current) || !timeo)
 601                         break;
 602         }
 603         remove_wait_queue(sk_sleep(sk), &wait);
 604         sk->sk_write_pending -= writebias;
 605         sk->sk_wait_pending--;
 606         return timeo;
 607 }
 608
 609 /*
 610  *      Connect to a remote host. There is regrettably still a little
 611  *      TCP 'magic' in here.
 612  */
 613 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 614                           int addr_len, int flags, int is_sendmsg)
 615 {
 616         struct sock *sk = sock->sk;
 617         int err;
 618         long timeo;
 619
 620         /*
 621          * uaddr can be NULL and addr_len can be 0 if:
 622          * sk is a TCP fastopen active socket and
 623          * TCP_FASTOPEN_CONNECT sockopt is set and
 624          * we already have a valid cookie for this socket.
 625          * In this case, user can call write() after connect().
 626          * write() will invoke tcp_sendmsg_fastopen() which calls
 627          * __inet_stream_connect().
 628          */
 629         if (uaddr) {
 630                 if (addr_len < sizeof(uaddr->sa_family))
 631                         return -EINVAL;
 632
 633                 if (uaddr->sa_family == AF_UNSPEC) {
 634                         err = sk->sk_prot->disconnect(sk, flags);
 635                         sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 636                         goto out;
 637                 }
 638         }
 639
 640         switch (sock->state) {
 641         default:
 642                 err = -EINVAL;
 643                 goto out;
 644         case SS_CONNECTED:
 645                 err = -EISCONN;
 646                 goto out;
 647         case SS_CONNECTING:
 648                 if (inet_sk(sk)->defer_connect)
 649                         err = is_sendmsg ? -EINPROGRESS : -EISCONN;
 650                 else
 651                         err = -EALREADY;
 652                 /* Fall out of switch with err, set for this state */
 653                 break;
 654         case SS_UNCONNECTED:
 655                 err = -EISCONN;
 656                 if (sk->sk_state != TCP_CLOSE)
 657                         goto out;
 658
 659                 if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
 660                         err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
 661                         if (err)
 662                                 goto out;
 663                 }
 664
 665                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
 666                 if (err < 0)
 667                         goto out;
 668
 669                 sock->state = SS_CONNECTING;
 670
 671                 if (!err && inet_sk(sk)->defer_connect)
 672                         goto out;
 673
 674                 /* Just entered SS_CONNECTING state; the only
 675                  * difference is that return value in non-blocking
 676                  * case is EINPROGRESS, rather than EALREADY.
 677                  */
 678                 err = -EINPROGRESS;
 679                 break;
 680         }
 681
 682         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 683
 684         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 685                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
 686                                 tcp_sk(sk)->fastopen_req &&
 687                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
 688
 689                 /* Error code is set above */
 690                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
 691                         goto out;
 692
 693                 err = sock_intr_errno(timeo);
 694                 if (signal_pending(current))
 695                         goto out;
 696         }
 697
 698         /* Connection was closed by RST, timeout, ICMP error
 699          * or another process disconnected us.
 700          */
 701         if (sk->sk_state == TCP_CLOSE)
 702                 goto sock_error;
 703
 704         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 705          * and error was received after socket entered established state.
 706          * Hence, it is handled normally after connect() return successfully.
 707          */
 708
 709         sock->state = SS_CONNECTED;
 710         err = 0;
 711 out:
 712         return err;
 713
 714 sock_error:
 715         err = sock_error(sk) ? : -ECONNABORTED;
 716         sock->state = SS_UNCONNECTED;
 717         if (sk->sk_prot->disconnect(sk, flags))
 718                 sock->state = SS_DISCONNECTING;
 719         goto out;
 720 }
 721 EXPORT_SYMBOL(__inet_stream_connect);
 722
 723 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 724                         int addr_len, int flags)
 725 {
 726         int err;
 727
 728         lock_sock(sock->sk);
 729         err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
 730         release_sock(sock->sk);
 731         return err;
 732 }
 733 EXPORT_SYMBOL(inet_stream_connect);
 734
 735 void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
 736 {
 737         sock_rps_record_flow(newsk);
 738         WARN_ON(!((1 << newsk->sk_state) &
 739                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
 740                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 741
 742         if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
 743                 set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
 744         sock_graft(newsk, newsock);
 745
 746         newsock->state = SS_CONNECTED;
 747 }
 748
 749 /*
 750  *      Accept a pending connection. The TCP layer now gives BSD semantics.
 751  */
 752
 753 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
 754                 bool kern)
 755 {
 756         struct sock *sk1 = sock->sk, *sk2;
 757         int err = -EINVAL;
 758
 759         /* IPV6_ADDRFORM can change sk->sk_prot under us. */
 760         sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
 761         if (!sk2)
 762                 return err;
 763
 764         lock_sock(sk2);
 765         __inet_accept(sock, newsock, sk2);
 766         release_sock(sk2);
 767         return 0;
 768 }
 769 EXPORT_SYMBOL(inet_accept);
 770
 771 /*
 772  *      This does both peername and sockname.
 773  */
 774 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 775                  int peer)
 776 {
 777         struct sock *sk         = sock->sk;
 778         struct inet_sock *inet  = inet_sk(sk);
 779         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 780
 781         sin->sin_family = AF_INET;
 782         lock_sock(sk);
 783         if (peer) {
 784                 if (!inet->inet_dport ||
 785                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 786                      peer == 1)) {
 787                         release_sock(sk);
 788                         return -ENOTCONN;
 789                 }
 790                 sin->sin_port = inet->inet_dport;
 791                 sin->sin_addr.s_addr = inet->inet_daddr;
 792                 BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
 793                                        CGROUP_INET4_GETPEERNAME);
 794         } else {
 795                 __be32 addr = inet->inet_rcv_saddr;
 796                 if (!addr)
 797                         addr = inet->inet_saddr;
 798                 sin->sin_port = inet->inet_sport;
 799                 sin->sin_addr.s_addr = addr;
 800                 BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
 801                                        CGROUP_INET4_GETSOCKNAME);
 802         }
 803         release_sock(sk);
 804         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 805         return sizeof(*sin);
 806 }
 807 EXPORT_SYMBOL(inet_getname);
 808
 809 int inet_send_prepare(struct sock *sk)
 810 {
 811         sock_rps_record_flow(sk);
 812
 813         /* We may need to bind the socket. */
 814         if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
 815             inet_autobind(sk))
 816                 return -EAGAIN;
 817
 818         return 0;
 819 }
 820 EXPORT_SYMBOL_GPL(inet_send_prepare);
 821
 822 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 823 {
 824         struct sock *sk = sock->sk;
 825
 826         if (unlikely(inet_send_prepare(sk)))
 827                 return -EAGAIN;
 828
 829         return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
 830                                sk, msg, size);
 831 }
 832 EXPORT_SYMBOL(inet_sendmsg);
 833
 834 void inet_splice_eof(struct socket *sock)
 835 {
 836         const struct proto *prot;
 837         struct sock *sk = sock->sk;
 838
 839         if (unlikely(inet_send_prepare(sk)))
 840                 return;
 841
 842         /* IPV6_ADDRFORM can change sk->sk_prot under us. */
 843         prot = READ_ONCE(sk->sk_prot);
 844         if (prot->splice_eof)
 845                 prot->splice_eof(sock);
 846 }
 847 EXPORT_SYMBOL_GPL(inet_splice_eof);
 848
 849 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 850                       size_t size, int flags)
 851 {
 852         struct sock *sk = sock->sk;
 853         const struct proto *prot;
 854
 855         if (unlikely(inet_send_prepare(sk)))
 856                 return -EAGAIN;
 857
 858         /* IPV6_ADDRFORM can change sk->sk_prot under us. */
 859         prot = READ_ONCE(sk->sk_prot);
 860         if (prot->sendpage)
 861                 return prot->sendpage(sk, page, offset, size, flags);
 862         return sock_no_sendpage(sock, page, offset, size, flags);
 863 }
 864 EXPORT_SYMBOL(inet_sendpage);
 865
 866 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
 867                                           size_t, int, int *));
 868 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 869                  int flags)
 870 {
 871         struct sock *sk = sock->sk;
 872         int addr_len = 0;
 873         int err;
 874
 875         if (likely(!(flags & MSG_ERRQUEUE)))
 876                 sock_rps_record_flow(sk);
 877
 878         err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
 879                               sk, msg, size, flags, &addr_len);
 880         if (err >= 0)
 881                 msg->msg_namelen = addr_len;
 882         return err;
 883 }
 884 EXPORT_SYMBOL(inet_recvmsg);
 885
 886 int inet_shutdown(struct socket *sock, int how)
 887 {
 888         struct sock *sk = sock->sk;
 889         int err = 0;
 890
 891         /* This should really check to make sure
 892          * the socket is a TCP socket. (WHY AC...)
 893          */
 894         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 895                        1->2 bit 2 snds.
 896                        2->3 */
 897         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 898                 return -EINVAL;
 899
 900         lock_sock(sk);
 901         if (sock->state == SS_CONNECTING) {
 902                 if ((1 << sk->sk_state) &
 903                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 904                         sock->state = SS_DISCONNECTING;
 905                 else
 906                         sock->state = SS_CONNECTED;
 907         }
 908
 909         switch (sk->sk_state) {
 910         case TCP_CLOSE:
 911                 err = -ENOTCONN;
 912                 /* Hack to wake up other listeners, who can poll for
 913                    EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
 914                 fallthrough;
 915         default:
 916                 WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
 917                 if (sk->sk_prot->shutdown)
 918                         sk->sk_prot->shutdown(sk, how);
 919                 break;
 920
 921         /* Remaining two branches are temporary solution for missing
 922          * close() in multithreaded environment. It is _not_ a good idea,
 923          * but we have no choice until close() is repaired at VFS level.
 924          */
 925         case TCP_LISTEN:
 926                 if (!(how & RCV_SHUTDOWN))
 927                         break;
 928                 fallthrough;
 929         case TCP_SYN_SENT:
 930                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 931                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 932                 break;
 933         }
 934
 935         /* Wake up anyone sleeping in poll. */
 936         sk->sk_state_change(sk);
 937         release_sock(sk);
 938         return err;
 939 }
 940 EXPORT_SYMBOL(inet_shutdown);
 941
 942 /*
 943  *      ioctl() calls you can issue on an INET socket. Most of these are
 944  *      device configuration and stuff and very rarely used. Some ioctls
 945  *      pass on to the socket itself.
 946  *
 947  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 948  *      loads the devconfigure module does its configuring and unloads it.
 949  *      There's a good 20K of config code hanging around the kernel.
 950  */
 951
 952 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 953 {
 954         struct sock *sk = sock->sk;
 955         int err = 0;
 956         struct net *net = sock_net(sk);
 957         void __user *p = (void __user *)arg;
 958         struct ifreq ifr;
 959         struct rtentry rt;
 960
 961         switch (cmd) {
 962         case SIOCADDRT:
 963         case SIOCDELRT:
 964                 if (copy_from_user(&rt, p, sizeof(struct rtentry)))
 965                         return -EFAULT;
 966                 err = ip_rt_ioctl(net, cmd, &rt);
 967                 break;
 968         case SIOCRTMSG:
 969                 err = -EINVAL;
 970                 break;
 971         case SIOCDARP:
 972         case SIOCGARP:
 973         case SIOCSARP:
 974                 err = arp_ioctl(net, cmd, (void __user *)arg);
 975                 break;
 976         case SIOCGIFADDR:
 977         case SIOCGIFBRDADDR:
 978         case SIOCGIFNETMASK:
 979         case SIOCGIFDSTADDR:
 980         case SIOCGIFPFLAGS:
 981                 if (get_user_ifreq(&ifr, NULL, p))
 982                         return -EFAULT;
 983                 err = devinet_ioctl(net, cmd, &ifr);
 984                 if (!err && put_user_ifreq(&ifr, p))
 985                         err = -EFAULT;
 986                 break;
 987
 988         case SIOCSIFADDR:
 989         case SIOCSIFBRDADDR:
 990         case SIOCSIFNETMASK:
 991         case SIOCSIFDSTADDR:
 992         case SIOCSIFPFLAGS:
 993         case SIOCSIFFLAGS:
 994                 if (get_user_ifreq(&ifr, NULL, p))
 995                         return -EFAULT;
 996                 err = devinet_ioctl(net, cmd, &ifr);
 997                 break;
 998         default:
 999                 if (sk->sk_prot->ioctl)
1000                         err = sk->sk_prot->ioctl(sk, cmd, arg);
1001                 else
1002                         err = -ENOIOCTLCMD;
1003                 break;
1004         }
1005         return err;
1006 }
1007 EXPORT_SYMBOL(inet_ioctl);
1008
1009 #ifdef CONFIG_COMPAT
1010 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1011                 struct compat_rtentry __user *ur)
1012 {
1013         compat_uptr_t rtdev;
1014         struct rtentry rt;
1015
1016         if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1017                         3 * sizeof(struct sockaddr)) ||
1018             get_user(rt.rt_flags, &ur->rt_flags) ||
1019             get_user(rt.rt_metric, &ur->rt_metric) ||
1020             get_user(rt.rt_mtu, &ur->rt_mtu) ||
1021             get_user(rt.rt_window, &ur->rt_window) ||
1022             get_user(rt.rt_irtt, &ur->rt_irtt) ||
1023             get_user(rtdev, &ur->rt_dev))
1024                 return -EFAULT;
1025
1026         rt.rt_dev = compat_ptr(rtdev);
1027         return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1028 }
1029
1030 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1031 {
1032         void __user *argp = compat_ptr(arg);
1033         struct sock *sk = sock->sk;
1034
1035         switch (cmd) {
1036         case SIOCADDRT:
1037         case SIOCDELRT:
1038                 return inet_compat_routing_ioctl(sk, cmd, argp);
1039         default:
1040                 if (!sk->sk_prot->compat_ioctl)
1041                         return -ENOIOCTLCMD;
1042                 return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1043         }
1044 }
1045 #endif /* CONFIG_COMPAT */
1046
1047 const struct proto_ops inet_stream_ops = {
1048         .family            = PF_INET,
1049         .owner             = THIS_MODULE,
1050         .release           = inet_release,
1051         .bind              = inet_bind,
1052         .connect           = inet_stream_connect,
1053         .socketpair        = sock_no_socketpair,
1054         .accept            = inet_accept,
1055         .getname           = inet_getname,
1056         .poll              = tcp_poll,
1057         .ioctl             = inet_ioctl,
1058         .gettstamp         = sock_gettstamp,
1059         .listen            = inet_listen,
1060         .shutdown          = inet_shutdown,
1061         .setsockopt        = sock_common_setsockopt,
1062         .getsockopt        = sock_common_getsockopt,
1063         .sendmsg           = inet_sendmsg,
1064         .recvmsg           = inet_recvmsg,
1065 #ifdef CONFIG_MMU
1066         .mmap              = tcp_mmap,
1067 #endif
1068         .splice_eof        = inet_splice_eof,
1069         .sendpage          = inet_sendpage,
1070         .splice_read       = tcp_splice_read,
1071         .read_sock         = tcp_read_sock,
1072         .read_skb          = tcp_read_skb,
1073         .sendmsg_locked    = tcp_sendmsg_locked,
1074         .sendpage_locked   = tcp_sendpage_locked,
1075         .peek_len          = tcp_peek_len,
1076 #ifdef CONFIG_COMPAT
1077         .compat_ioctl      = inet_compat_ioctl,
1078 #endif
1079         .set_rcvlowat      = tcp_set_rcvlowat,
1080 };
1081 EXPORT_SYMBOL(inet_stream_ops);
1082
1083 const struct proto_ops inet_dgram_ops = {
1084         .family            = PF_INET,
1085         .owner             = THIS_MODULE,
1086         .release           = inet_release,
1087         .bind              = inet_bind,
1088         .connect           = inet_dgram_connect,
1089         .socketpair        = sock_no_socketpair,
1090         .accept            = sock_no_accept,
1091         .getname           = inet_getname,
1092         .poll              = udp_poll,
1093         .ioctl             = inet_ioctl,
1094         .gettstamp         = sock_gettstamp,
1095         .listen            = sock_no_listen,
1096         .shutdown          = inet_shutdown,
1097         .setsockopt        = sock_common_setsockopt,
1098         .getsockopt        = sock_common_getsockopt,
1099         .sendmsg           = inet_sendmsg,
1100         .read_skb          = udp_read_skb,
1101         .recvmsg           = inet_recvmsg,
1102         .mmap              = sock_no_mmap,
1103         .splice_eof        = inet_splice_eof,
1104         .sendpage          = inet_sendpage,
1105         .set_peek_off      = sk_set_peek_off,
1106 #ifdef CONFIG_COMPAT
1107         .compat_ioctl      = inet_compat_ioctl,
1108 #endif
1109 };
1110 EXPORT_SYMBOL(inet_dgram_ops);
1111
1112 /*
1113  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1114  * udp_poll
1115  */
1116 static const struct proto_ops inet_sockraw_ops = {
1117         .family            = PF_INET,
1118         .owner             = THIS_MODULE,
1119         .release           = inet_release,
1120         .bind              = inet_bind,
1121         .connect           = inet_dgram_connect,
1122         .socketpair        = sock_no_socketpair,
1123         .accept            = sock_no_accept,
1124         .getname           = inet_getname,
1125         .poll              = datagram_poll,
1126         .ioctl             = inet_ioctl,
1127         .gettstamp         = sock_gettstamp,
1128         .listen            = sock_no_listen,
1129         .shutdown          = inet_shutdown,
1130         .setsockopt        = sock_common_setsockopt,
1131         .getsockopt        = sock_common_getsockopt,
1132         .sendmsg           = inet_sendmsg,
1133         .recvmsg           = inet_recvmsg,
1134         .mmap              = sock_no_mmap,
1135         .splice_eof        = inet_splice_eof,
1136         .sendpage          = inet_sendpage,
1137 #ifdef CONFIG_COMPAT
1138         .compat_ioctl      = inet_compat_ioctl,
1139 #endif
1140 };
1141
1142 static const struct net_proto_family inet_family_ops = {
1143         .family = PF_INET,
1144         .create = inet_create,
1145         .owner  = THIS_MODULE,
1146 };
1147
1148 /* Upon startup we insert all the elements in inetsw_array[] into
1149  * the linked list inetsw.
1150  */
1151 static struct inet_protosw inetsw_array[] =
1152 {
1153         {
1154                 .type =       SOCK_STREAM,
1155                 .protocol =   IPPROTO_TCP,
1156                 .prot =       &tcp_prot,
1157                 .ops =        &inet_stream_ops,
1158                 .flags =      INET_PROTOSW_PERMANENT |
1159                               INET_PROTOSW_ICSK,
1160         },
1161
1162         {
1163                 .type =       SOCK_DGRAM,
1164                 .protocol =   IPPROTO_UDP,
1165                 .prot =       &udp_prot,
1166                 .ops =        &inet_dgram_ops,
1167                 .flags =      INET_PROTOSW_PERMANENT,
1168        },
1169
1170        {
1171                 .type =       SOCK_DGRAM,
1172                 .protocol =   IPPROTO_ICMP,
1173                 .prot =       &ping_prot,
1174                 .ops =        &inet_sockraw_ops,
1175                 .flags =      INET_PROTOSW_REUSE,
1176        },
1177
1178        {
1179                .type =       SOCK_RAW,
1180                .protocol =   IPPROTO_IP,        /* wild card */
1181                .prot =       &raw_prot,
1182                .ops =        &inet_sockraw_ops,
1183                .flags =      INET_PROTOSW_REUSE,
1184        }
1185 };
1186
1187 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1188
1189 void inet_register_protosw(struct inet_protosw *p)
1190 {
1191         struct list_head *lh;
1192         struct inet_protosw *answer;
1193         int protocol = p->protocol;
1194         struct list_head *last_perm;
1195
1196         spin_lock_bh(&inetsw_lock);
1197
1198         if (p->type >= SOCK_MAX)
1199                 goto out_illegal;
1200
1201         /* If we are trying to override a permanent protocol, bail. */
1202         last_perm = &inetsw[p->type];
1203         list_for_each(lh, &inetsw[p->type]) {
1204                 answer = list_entry(lh, struct inet_protosw, list);
1205                 /* Check only the non-wild match. */
1206                 if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1207                         break;
1208                 if (protocol == answer->protocol)
1209                         goto out_permanent;
1210                 last_perm = lh;
1211         }
1212
1213         /* Add the new entry after the last permanent entry if any, so that
1214          * the new entry does not override a permanent entry when matched with
1215          * a wild-card protocol. But it is allowed to override any existing
1216          * non-permanent entry.  This means that when we remove this entry, the
1217          * system automatically returns to the old behavior.
1218          */
1219         list_add_rcu(&p->list, last_perm);
1220 out:
1221         spin_unlock_bh(&inetsw_lock);
1222
1223         return;
1224
1225 out_permanent:
1226         pr_err("Attempt to override permanent protocol %d\n", protocol);
1227         goto out;
1228
1229 out_illegal:
1230         pr_err("Ignoring attempt to register invalid socket type %d\n",
1231                p->type);
1232         goto out;
1233 }
1234 EXPORT_SYMBOL(inet_register_protosw);
1235
1236 void inet_unregister_protosw(struct inet_protosw *p)
1237 {
1238         if (INET_PROTOSW_PERMANENT & p->flags) {
1239                 pr_err("Attempt to unregister permanent protocol %d\n",
1240                        p->protocol);
1241         } else {
1242                 spin_lock_bh(&inetsw_lock);
1243                 list_del_rcu(&p->list);
1244                 spin_unlock_bh(&inetsw_lock);
1245
1246                 synchronize_net();
1247         }
1248 }
1249 EXPORT_SYMBOL(inet_unregister_protosw);
1250
1251 static int inet_sk_reselect_saddr(struct sock *sk)
1252 {
1253         struct inet_sock *inet = inet_sk(sk);
1254         __be32 old_saddr = inet->inet_saddr;
1255         __be32 daddr = inet->inet_daddr;
1256         struct flowi4 *fl4;
1257         struct rtable *rt;
1258         __be32 new_saddr;
1259         struct ip_options_rcu *inet_opt;
1260         int err;
1261
1262         inet_opt = rcu_dereference_protected(inet->inet_opt,
1263                                              lockdep_sock_is_held(sk));
1264         if (inet_opt && inet_opt->opt.srr)
1265                 daddr = inet_opt->opt.faddr;
1266
1267         /* Query new route. */
1268         fl4 = &inet->cork.fl.u.ip4;
1269         rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1270                               sk->sk_protocol, inet->inet_sport,
1271                               inet->inet_dport, sk);
1272         if (IS_ERR(rt))
1273                 return PTR_ERR(rt);
1274
1275         new_saddr = fl4->saddr;
1276
1277         if (new_saddr == old_saddr) {
1278                 sk_setup_caps(sk, &rt->dst);
1279                 return 0;
1280         }
1281
1282         err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1283         if (err) {
1284                 ip_rt_put(rt);
1285                 return err;
1286         }
1287
1288         sk_setup_caps(sk, &rt->dst);
1289
1290         if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1291                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1292                         __func__, &old_saddr, &new_saddr);
1293         }
1294
1295         /*
1296          * XXX The only one ugly spot where we need to
1297          * XXX really change the sockets identity after
1298          * XXX it has entered the hashes. -DaveM
1299          *
1300          * Besides that, it does not check for connection
1301          * uniqueness. Wait for troubles.
1302          */
1303         return __sk_prot_rehash(sk);
1304 }
1305
1306 int inet_sk_rebuild_header(struct sock *sk)
1307 {
1308         struct inet_sock *inet = inet_sk(sk);
1309         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1310         __be32 daddr;
1311         struct ip_options_rcu *inet_opt;
1312         struct flowi4 *fl4;
1313         int err;
1314
1315         /* Route is OK, nothing to do. */
1316         if (rt)
1317                 return 0;
1318
1319         /* Reroute. */
1320         rcu_read_lock();
1321         inet_opt = rcu_dereference(inet->inet_opt);
1322         daddr = inet->inet_daddr;
1323         if (inet_opt && inet_opt->opt.srr)
1324                 daddr = inet_opt->opt.faddr;
1325         rcu_read_unlock();
1326         fl4 = &inet->cork.fl.u.ip4;
1327         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1328                                    inet->inet_dport, inet->inet_sport,
1329                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1330                                    sk->sk_bound_dev_if);
1331         if (!IS_ERR(rt)) {
1332                 err = 0;
1333                 sk_setup_caps(sk, &rt->dst);
1334         } else {
1335                 err = PTR_ERR(rt);
1336
1337                 /* Routing failed... */
1338                 sk->sk_route_caps = 0;
1339                 /*
1340                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1341                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1342                  */
1343                 if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1344                     sk->sk_state != TCP_SYN_SENT ||
1345                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1346                     (err = inet_sk_reselect_saddr(sk)) != 0)
1347                         WRITE_ONCE(sk->sk_err_soft, -err);
1348         }
1349
1350         return err;
1351 }
1352 EXPORT_SYMBOL(inet_sk_rebuild_header);
1353
1354 void inet_sk_set_state(struct sock *sk, int state)
1355 {
1356         trace_inet_sock_set_state(sk, sk->sk_state, state);
1357         sk->sk_state = state;
1358 }
1359 EXPORT_SYMBOL(inet_sk_set_state);
1360
1361 void inet_sk_state_store(struct sock *sk, int newstate)
1362 {
1363         trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1364         smp_store_release(&sk->sk_state, newstate);
1365 }
1366
1367 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1368                                  netdev_features_t features)
1369 {
1370         bool udpfrag = false, fixedid = false, gso_partial, encap;
1371         struct sk_buff *segs = ERR_PTR(-EINVAL);
1372         const struct net_offload *ops;
1373         unsigned int offset = 0;
1374         struct iphdr *iph;
1375         int proto, tot_len;
1376         int nhoff;
1377         int ihl;
1378         int id;
1379
1380         skb_reset_network_header(skb);
1381         nhoff = skb_network_header(skb) - skb_mac_header(skb);
1382         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1383                 goto out;
1384
1385         iph = ip_hdr(skb);
1386         ihl = iph->ihl * 4;
1387         if (ihl < sizeof(*iph))
1388                 goto out;
1389
1390         id = ntohs(iph->id);
1391         proto = iph->protocol;
1392
1393         /* Warning: after this point, iph might be no longer valid */
1394         if (unlikely(!pskb_may_pull(skb, ihl)))
1395                 goto out;
1396         __skb_pull(skb, ihl);
1397
1398         encap = SKB_GSO_CB(skb)->encap_level > 0;
1399         if (encap)
1400                 features &= skb->dev->hw_enc_features;
1401         SKB_GSO_CB(skb)->encap_level += ihl;
1402
1403         skb_reset_transport_header(skb);
1404
1405         segs = ERR_PTR(-EPROTONOSUPPORT);
1406
1407         if (!skb->encapsulation || encap) {
1408                 udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1409                 fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1410
1411                 /* fixed ID is invalid if DF bit is not set */
1412                 if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1413                         goto out;
1414         }
1415
1416         ops = rcu_dereference(inet_offloads[proto]);
1417         if (likely(ops && ops->callbacks.gso_segment)) {
1418                 segs = ops->callbacks.gso_segment(skb, features);
1419                 if (!segs)
1420                         skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1421         }
1422
1423         if (IS_ERR_OR_NULL(segs))
1424                 goto out;
1425
1426         gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1427
1428         skb = segs;
1429         do {
1430                 iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1431                 if (udpfrag) {
1432                         iph->frag_off = htons(offset >> 3);
1433                         if (skb->next)
1434                                 iph->frag_off |= htons(IP_MF);
1435                         offset += skb->len - nhoff - ihl;
1436                         tot_len = skb->len - nhoff;
1437                 } else if (skb_is_gso(skb)) {
1438                         if (!fixedid) {
1439                                 iph->id = htons(id);
1440                                 id += skb_shinfo(skb)->gso_segs;
1441                         }
1442
1443                         if (gso_partial)
1444                                 tot_len = skb_shinfo(skb)->gso_size +
1445                                           SKB_GSO_CB(skb)->data_offset +
1446                                           skb->head - (unsigned char *)iph;
1447                         else
1448                                 tot_len = skb->len - nhoff;
1449                 } else {
1450                         if (!fixedid)
1451                                 iph->id = htons(id++);
1452                         tot_len = skb->len - nhoff;
1453                 }
1454                 iph->tot_len = htons(tot_len);
1455                 ip_send_check(iph);
1456                 if (encap)
1457                         skb_reset_inner_headers(skb);
1458                 skb->network_header = (u8 *)iph - skb->head;
1459                 skb_reset_mac_len(skb);
1460         } while ((skb = skb->next));
1461
1462 out:
1463         return segs;
1464 }
1465
1466 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1467                                         netdev_features_t features)
1468 {
1469         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1470                 return ERR_PTR(-EINVAL);
1471
1472         return inet_gso_segment(skb, features);
1473 }
1474
1475 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1476 {
1477         const struct net_offload *ops;
1478         struct sk_buff *pp = NULL;
1479         const struct iphdr *iph;
1480         struct sk_buff *p;
1481         unsigned int hlen;
1482         unsigned int off;
1483         unsigned int id;
1484         int flush = 1;
1485         int proto;
1486
1487         off = skb_gro_offset(skb);
1488         hlen = off + sizeof(*iph);
1489         iph = skb_gro_header(skb, hlen, off);
1490         if (unlikely(!iph))
1491                 goto out;
1492
1493         proto = iph->protocol;
1494
1495         ops = rcu_dereference(inet_offloads[proto]);
1496         if (!ops || !ops->callbacks.gro_receive)
1497                 goto out;
1498
1499         if (*(u8 *)iph != 0x45)
1500                 goto out;
1501
1502         if (ip_is_fragment(iph))
1503                 goto out;
1504
1505         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1506                 goto out;
1507
1508         NAPI_GRO_CB(skb)->proto = proto;
1509         id = ntohl(*(__be32 *)&iph->id);
1510         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1511         id >>= 16;
1512
1513         list_for_each_entry(p, head, list) {
1514                 struct iphdr *iph2;
1515                 u16 flush_id;
1516
1517                 if (!NAPI_GRO_CB(p)->same_flow)
1518                         continue;
1519
1520                 iph2 = (struct iphdr *)(p->data + off);
1521                 /* The above works because, with the exception of the top
1522                  * (inner most) layer, we only aggregate pkts with the same
1523                  * hdr length so all the hdrs we'll need to verify will start
1524                  * at the same offset.
1525                  */
1526                 if ((iph->protocol ^ iph2->protocol) |
1527                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1528                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1529                         NAPI_GRO_CB(p)->same_flow = 0;
1530                         continue;
1531                 }
1532
1533                 /* All fields must match except length and checksum. */
1534                 NAPI_GRO_CB(p)->flush |=
1535                         (iph->ttl ^ iph2->ttl) |
1536                         (iph->tos ^ iph2->tos) |
1537                         ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1538
1539                 NAPI_GRO_CB(p)->flush |= flush;
1540
1541                 /* We need to store of the IP ID check to be included later
1542                  * when we can verify that this packet does in fact belong
1543                  * to a given flow.
1544                  */
1545                 flush_id = (u16)(id - ntohs(iph2->id));
1546
1547                 /* This bit of code makes it much easier for us to identify
1548                  * the cases where we are doing atomic vs non-atomic IP ID
1549                  * checks.  Specifically an atomic check can return IP ID
1550                  * values 0 - 0xFFFF, while a non-atomic check can only
1551                  * return 0 or 0xFFFF.
1552                  */
1553                 if (!NAPI_GRO_CB(p)->is_atomic ||
1554                     !(iph->frag_off & htons(IP_DF))) {
1555                         flush_id ^= NAPI_GRO_CB(p)->count;
1556                         flush_id = flush_id ? 0xFFFF : 0;
1557                 }
1558
1559                 /* If the previous IP ID value was based on an atomic
1560                  * datagram we can overwrite the value and ignore it.
1561                  */
1562                 if (NAPI_GRO_CB(skb)->is_atomic)
1563                         NAPI_GRO_CB(p)->flush_id = flush_id;
1564                 else
1565                         NAPI_GRO_CB(p)->flush_id |= flush_id;
1566         }
1567
1568         NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1569         NAPI_GRO_CB(skb)->flush |= flush;
1570         skb_set_network_header(skb, off);
1571         /* The above will be needed by the transport layer if there is one
1572          * immediately following this IP hdr.
1573          */
1574
1575         /* Note : No need to call skb_gro_postpull_rcsum() here,
1576          * as we already checked checksum over ipv4 header was 0
1577          */
1578         skb_gro_pull(skb, sizeof(*iph));
1579         skb_set_transport_header(skb, skb_gro_offset(skb));
1580
1581         pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1582                                        ops->callbacks.gro_receive, head, skb);
1583
1584 out:
1585         skb_gro_flush_final(skb, pp, flush);
1586
1587         return pp;
1588 }
1589
1590 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1591                                         struct sk_buff *skb)
1592 {
1593         if (NAPI_GRO_CB(skb)->encap_mark) {
1594                 NAPI_GRO_CB(skb)->flush = 1;
1595                 return NULL;
1596         }
1597
1598         NAPI_GRO_CB(skb)->encap_mark = 1;
1599
1600         return inet_gro_receive(head, skb);
1601 }
1602
1603 #define SECONDS_PER_DAY 86400
1604
1605 /* inet_current_timestamp - Return IP network timestamp
1606  *
1607  * Return milliseconds since midnight in network byte order.
1608  */
1609 __be32 inet_current_timestamp(void)
1610 {
1611         u32 secs;
1612         u32 msecs;
1613         struct timespec64 ts;
1614
1615         ktime_get_real_ts64(&ts);
1616
1617         /* Get secs since midnight. */
1618         (void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1619         /* Convert to msecs. */
1620         msecs = secs * MSEC_PER_SEC;
1621         /* Convert nsec to msec. */
1622         msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1623
1624         /* Convert to network byte order. */
1625         return htonl(msecs);
1626 }
1627 EXPORT_SYMBOL(inet_current_timestamp);
1628
1629 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1630 {
1631         if (sk->sk_family == AF_INET)
1632                 return ip_recv_error(sk, msg, len, addr_len);
1633 #if IS_ENABLED(CONFIG_IPV6)
1634         if (sk->sk_family == AF_INET6)
1635                 return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1636 #endif
1637         return -EINVAL;
1638 }
1639
1640 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1641 {
1642         struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1643         const struct net_offload *ops;
1644         __be16 totlen = iph->tot_len;
1645         int proto = iph->protocol;
1646         int err = -ENOSYS;
1647
1648         if (skb->encapsulation) {
1649                 skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1650                 skb_set_inner_network_header(skb, nhoff);
1651         }
1652
1653         iph_set_totlen(iph, skb->len - nhoff);
1654         csum_replace2(&iph->check, totlen, iph->tot_len);
1655
1656         ops = rcu_dereference(inet_offloads[proto]);
1657         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1658                 goto out;
1659
1660         /* Only need to add sizeof(*iph) to get to the next hdr below
1661          * because any hdr with option will have been flushed in
1662          * inet_gro_receive().
1663          */
1664         err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1665                               tcp4_gro_complete, udp4_gro_complete,
1666                               skb, nhoff + sizeof(*iph));
1667
1668 out:
1669         return err;
1670 }
1671
1672 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1673 {
1674         skb->encapsulation = 1;
1675         skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1676         return inet_gro_complete(skb, nhoff);
1677 }
1678
1679 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1680                          unsigned short type, unsigned char protocol,
1681                          struct net *net)
1682 {
1683         struct socket *sock;
1684         int rc = sock_create_kern(net, family, type, protocol, &sock);
1685
1686         if (rc == 0) {
1687                 *sk = sock->sk;
1688                 (*sk)->sk_allocation = GFP_ATOMIC;
1689                 (*sk)->sk_use_task_frag = false;
1690                 /*
1691                  * Unhash it so that IP input processing does not even see it,
1692                  * we do not wish this socket to see incoming packets.
1693                  */
1694                 (*sk)->sk_prot->unhash(*sk);
1695         }
1696         return rc;
1697 }
1698 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1699
1700 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1701 {
1702         unsigned long res = 0;
1703         int i;
1704
1705         for_each_possible_cpu(i)
1706                 res += snmp_get_cpu_field(mib, i, offt);
1707         return res;
1708 }
1709 EXPORT_SYMBOL_GPL(snmp_fold_field);
1710
1711 #if BITS_PER_LONG==32
1712
1713 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1714                          size_t syncp_offset)
1715 {
1716         void *bhptr;
1717         struct u64_stats_sync *syncp;
1718         u64 v;
1719         unsigned int start;
1720
1721         bhptr = per_cpu_ptr(mib, cpu);
1722         syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1723         do {
1724                 start = u64_stats_fetch_begin(syncp);
1725                 v = *(((u64 *)bhptr) + offt);
1726         } while (u64_stats_fetch_retry(syncp, start));
1727
1728         return v;
1729 }
1730 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1731
1732 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1733 {
1734         u64 res = 0;
1735         int cpu;
1736
1737         for_each_possible_cpu(cpu) {
1738                 res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1739         }
1740         return res;
1741 }
1742 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1743 #endif
1744
1745 #ifdef CONFIG_IP_MULTICAST
1746 static const struct net_protocol igmp_protocol = {
1747         .handler =      igmp_rcv,
1748 };
1749 #endif
1750
1751 static const struct net_protocol tcp_protocol = {
1752         .handler        =       tcp_v4_rcv,
1753         .err_handler    =       tcp_v4_err,
1754         .no_policy      =       1,
1755         .icmp_strict_tag_validation = 1,
1756 };
1757
1758 static const struct net_protocol udp_protocol = {
1759         .handler =      udp_rcv,
1760         .err_handler =  udp_err,
1761         .no_policy =    1,
1762 };
1763
1764 static const struct net_protocol icmp_protocol = {
1765         .handler =      icmp_rcv,
1766         .err_handler =  icmp_err,
1767         .no_policy =    1,
1768 };
1769
1770 static __net_init int ipv4_mib_init_net(struct net *net)
1771 {
1772         int i;
1773
1774         net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1775         if (!net->mib.tcp_statistics)
1776                 goto err_tcp_mib;
1777         net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1778         if (!net->mib.ip_statistics)
1779                 goto err_ip_mib;
1780
1781         for_each_possible_cpu(i) {
1782                 struct ipstats_mib *af_inet_stats;
1783                 af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1784                 u64_stats_init(&af_inet_stats->syncp);
1785         }
1786
1787         net->mib.net_statistics = alloc_percpu(struct linux_mib);
1788         if (!net->mib.net_statistics)
1789                 goto err_net_mib;
1790         net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1791         if (!net->mib.udp_statistics)
1792                 goto err_udp_mib;
1793         net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1794         if (!net->mib.udplite_statistics)
1795                 goto err_udplite_mib;
1796         net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1797         if (!net->mib.icmp_statistics)
1798                 goto err_icmp_mib;
1799         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1800                                               GFP_KERNEL);
1801         if (!net->mib.icmpmsg_statistics)
1802                 goto err_icmpmsg_mib;
1803
1804         tcp_mib_init(net);
1805         return 0;
1806
1807 err_icmpmsg_mib:
1808         free_percpu(net->mib.icmp_statistics);
1809 err_icmp_mib:
1810         free_percpu(net->mib.udplite_statistics);
1811 err_udplite_mib:
1812         free_percpu(net->mib.udp_statistics);
1813 err_udp_mib:
1814         free_percpu(net->mib.net_statistics);
1815 err_net_mib:
1816         free_percpu(net->mib.ip_statistics);
1817 err_ip_mib:
1818         free_percpu(net->mib.tcp_statistics);
1819 err_tcp_mib:
1820         return -ENOMEM;
1821 }
1822
1823 static __net_exit void ipv4_mib_exit_net(struct net *net)
1824 {
1825         kfree(net->mib.icmpmsg_statistics);
1826         free_percpu(net->mib.icmp_statistics);
1827         free_percpu(net->mib.udplite_statistics);
1828         free_percpu(net->mib.udp_statistics);
1829         free_percpu(net->mib.net_statistics);
1830         free_percpu(net->mib.ip_statistics);
1831         free_percpu(net->mib.tcp_statistics);
1832 #ifdef CONFIG_MPTCP
1833         /* allocated on demand, see mptcp_init_sock() */
1834         free_percpu(net->mib.mptcp_statistics);
1835 #endif
1836 }
1837
1838 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1839         .init = ipv4_mib_init_net,
1840         .exit = ipv4_mib_exit_net,
1841 };
1842
1843 static int __init init_ipv4_mibs(void)
1844 {
1845         return register_pernet_subsys(&ipv4_mib_ops);
1846 }
1847
1848 static __net_init int inet_init_net(struct net *net)
1849 {
1850         /*
1851          * Set defaults for local port range
1852          */
1853         seqlock_init(&net->ipv4.ip_local_ports.lock);
1854         net->ipv4.ip_local_ports.range[0] =  32768;
1855         net->ipv4.ip_local_ports.range[1] =  60999;
1856
1857         seqlock_init(&net->ipv4.ping_group_range.lock);
1858         /*
1859          * Sane defaults - nobody may create ping sockets.
1860          * Boot scripts should set this to distro-specific group.
1861          */
1862         net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1863         net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1864
1865         /* Default values for sysctl-controlled parameters.
1866          * We set them here, in case sysctl is not compiled.
1867          */
1868         net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1869         net->ipv4.sysctl_ip_fwd_update_priority = 1;
1870         net->ipv4.sysctl_ip_dynaddr = 0;
1871         net->ipv4.sysctl_ip_early_demux = 1;
1872         net->ipv4.sysctl_udp_early_demux = 1;
1873         net->ipv4.sysctl_tcp_early_demux = 1;
1874         net->ipv4.sysctl_nexthop_compat_mode = 1;
1875 #ifdef CONFIG_SYSCTL
1876         net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1877 #endif
1878
1879         /* Some igmp sysctl, whose values are always used */
1880         net->ipv4.sysctl_igmp_max_memberships = 20;
1881         net->ipv4.sysctl_igmp_max_msf = 10;
1882         /* IGMP reports for link-local multicast groups are enabled by default */
1883         net->ipv4.sysctl_igmp_llm_reports = 1;
1884         net->ipv4.sysctl_igmp_qrv = 2;
1885
1886         net->ipv4.sysctl_fib_notify_on_flag_change = 0;
1887
1888         return 0;
1889 }
1890
1891 static __net_initdata struct pernet_operations af_inet_ops = {
1892         .init = inet_init_net,
1893 };
1894
1895 static int __init init_inet_pernet_ops(void)
1896 {
1897         return register_pernet_subsys(&af_inet_ops);
1898 }
1899
1900 static int ipv4_proc_init(void);
1901
1902 /*
1903  *      IP protocol layer initialiser
1904  */
1905
1906 static struct packet_offload ip_packet_offload __read_mostly = {
1907         .type = cpu_to_be16(ETH_P_IP),
1908         .callbacks = {
1909                 .gso_segment = inet_gso_segment,
1910                 .gro_receive = inet_gro_receive,
1911                 .gro_complete = inet_gro_complete,
1912         },
1913 };
1914
1915 static const struct net_offload ipip_offload = {
1916         .callbacks = {
1917                 .gso_segment    = ipip_gso_segment,
1918                 .gro_receive    = ipip_gro_receive,
1919                 .gro_complete   = ipip_gro_complete,
1920         },
1921 };
1922
1923 static int __init ipip_offload_init(void)
1924 {
1925         return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1926 }
1927
1928 static int __init ipv4_offload_init(void)
1929 {
1930         /*
1931          * Add offloads
1932          */
1933         if (udpv4_offload_init() < 0)
1934                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1935         if (tcpv4_offload_init() < 0)
1936                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1937         if (ipip_offload_init() < 0)
1938                 pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1939
1940         dev_add_offload(&ip_packet_offload);
1941         return 0;
1942 }
1943
1944 fs_initcall(ipv4_offload_init);
1945
1946 static struct packet_type ip_packet_type __read_mostly = {
1947         .type = cpu_to_be16(ETH_P_IP),
1948         .func = ip_rcv,
1949         .list_func = ip_list_rcv,
1950 };
1951
1952 static int __init inet_init(void)
1953 {
1954         struct inet_protosw *q;
1955         struct list_head *r;
1956         int rc;
1957
1958         sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1959
1960         raw_hashinfo_init(&raw_v4_hashinfo);
1961
1962         rc = proto_register(&tcp_prot, 1);
1963         if (rc)
1964                 goto out;
1965
1966         rc = proto_register(&udp_prot, 1);
1967         if (rc)
1968                 goto out_unregister_tcp_proto;
1969
1970         rc = proto_register(&raw_prot, 1);
1971         if (rc)
1972                 goto out_unregister_udp_proto;
1973
1974         rc = proto_register(&ping_prot, 1);
1975         if (rc)
1976                 goto out_unregister_raw_proto;
1977
1978         /*
1979          *      Tell SOCKET that we are alive...
1980          */
1981
1982         (void)sock_register(&inet_family_ops);
1983
1984 #ifdef CONFIG_SYSCTL
1985         ip_static_sysctl_init();
1986 #endif
1987
1988         /*
1989          *      Add all the base protocols.
1990          */
1991
1992         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1993                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1994         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1995                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1996         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1997                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1998 #ifdef CONFIG_IP_MULTICAST
1999         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
2000                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
2001 #endif
2002
2003         /* Register the socket-side information for inet_create. */
2004         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
2005                 INIT_LIST_HEAD(r);
2006
2007         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
2008                 inet_register_protosw(q);
2009
2010         /*
2011          *      Set the ARP module up
2012          */
2013
2014         arp_init();
2015
2016         /*
2017          *      Set the IP module up
2018          */
2019
2020         ip_init();
2021
2022         /* Initialise per-cpu ipv4 mibs */
2023         if (init_ipv4_mibs())
2024                 panic("%s: Cannot init ipv4 mibs\n", __func__);
2025
2026         /* Setup TCP slab cache for open requests. */
2027         tcp_init();
2028
2029         /* Setup UDP memory threshold */
2030         udp_init();
2031
2032         /* Add UDP-Lite (RFC 3828) */
2033         udplite4_register();
2034
2035         raw_init();
2036
2037         ping_init();
2038
2039         /*
2040          *      Set the ICMP layer up
2041          */
2042
2043         if (icmp_init() < 0)
2044                 panic("Failed to create the ICMP control socket.\n");
2045
2046         /*
2047          *      Initialise the multicast router
2048          */
2049 #if defined(CONFIG_IP_MROUTE)
2050         if (ip_mr_init())
2051                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2052 #endif
2053
2054         if (init_inet_pernet_ops())
2055                 pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2056
2057         ipv4_proc_init();
2058
2059         ipfrag_init();
2060
2061         dev_add_pack(&ip_packet_type);
2062
2063         ip_tunnel_core_init();
2064
2065         rc = 0;
2066 out:
2067         return rc;
2068 out_unregister_raw_proto:
2069         proto_unregister(&raw_prot);
2070 out_unregister_udp_proto:
2071         proto_unregister(&udp_prot);
2072 out_unregister_tcp_proto:
2073         proto_unregister(&tcp_prot);
2074         goto out;
2075 }
2076
2077 fs_initcall(inet_init);
2078
2079 /* ------------------------------------------------------------------------ */
2080
2081 #ifdef CONFIG_PROC_FS
2082 static int __init ipv4_proc_init(void)
2083 {
2084         int rc = 0;
2085
2086         if (raw_proc_init())
2087                 goto out_raw;
2088         if (tcp4_proc_init())
2089                 goto out_tcp;
2090         if (udp4_proc_init())
2091                 goto out_udp;
2092         if (ping_proc_init())
2093                 goto out_ping;
2094         if (ip_misc_proc_init())
2095                 goto out_misc;
2096 out:
2097         return rc;
2098 out_misc:
2099         ping_proc_exit();
2100 out_ping:
2101         udp4_proc_exit();
2102 out_udp:
2103         tcp4_proc_exit();
2104 out_tcp:
2105         raw_proc_exit();
2106 out_raw:
2107         rc = -ENOMEM;
2108         goto out;
2109 }
2110
2111 #else /* CONFIG_PROC_FS */
2112 static int __init ipv4_proc_init(void)
2113 {
2114         return 0;
2115 }
2116 #endif /* CONFIG_PROC_FS */