net/ipv4/af

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
inet_sock_destruct
inet_autobind
inet_listen
inet_create
inet_release
inet_bind
__inet_bind
inet_dgram_connect
inet_wait_for_connect
__inet_stream_connect
inet_stream_connect
inet_accept
inet_getname
inet_send_prepare
inet_sendmsg
inet_sendpage
inet_recvmsg
inet_shutdown
inet_ioctl
inet_compat_ioctl
inet_register_protosw
inet_unregister_protosw
inet_sk_reselect_saddr
inet_sk_rebuild_header
inet_sk_set_state
inet_sk_state_store
inet_gso_segment
ipip_gso_segment
inet_gro_receive
ipip_gro_receive
inet_current_timestamp
inet_recv_error
inet_gro_complete
ipip_gro_complete
inet_ctl_sock_create
snmp_get_cpu_field
snmp_fold_field
snmp_get_cpu_field64
snmp_fold_field64
ipv4_mib_init_net
ipv4_mib_exit_net
init_ipv4_mibs
inet_init_net
init_inet_pernet_ops
ipip_offload_init
ipv4_offload_init
inet_init
ipv4_proc_init
ipv4_proc_init
   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/tcp.h>
 103 #include <net/udp.h>
 104 #include <net/udplite.h>
 105 #include <net/ping.h>
 106 #include <linux/skbuff.h>
 107 #include <net/sock.h>
 108 #include <net/raw.h>
 109 #include <net/icmp.h>
 110 #include <net/inet_common.h>
 111 #include <net/ip_tunnels.h>
 112 #include <net/xfrm.h>
 113 #include <net/net_namespace.h>
 114 #include <net/secure_seq.h>
 115 #ifdef CONFIG_IP_MROUTE
 116 #include <linux/mroute.h>
 117 #endif
 118 #include <net/l3mdev.h>
 119 
 120 #include <trace/events/sock.h>
 121 
 122 /* The inetsw table contains everything that inet_create needs to
 123  * build a new socket.
 124  */
 125 static struct list_head inetsw[SOCK_MAX];
 126 static DEFINE_SPINLOCK(inetsw_lock);
 127 
 128 /* New destruction routine */
 129 
 130 void inet_sock_destruct(struct sock *sk)
 131 {
 132         struct inet_sock *inet = inet_sk(sk);
 133 
 134         __skb_queue_purge(&sk->sk_receive_queue);
 135         if (sk->sk_rx_skb_cache) {
 136                 __kfree_skb(sk->sk_rx_skb_cache);
 137                 sk->sk_rx_skb_cache = NULL;
 138         }
 139         __skb_queue_purge(&sk->sk_error_queue);
 140 
 141         sk_mem_reclaim(sk);
 142 
 143         if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
 144                 pr_err("Attempt to release TCP socket in state %d %p\n",
 145                        sk->sk_state, sk);
 146                 return;
 147         }
 148         if (!sock_flag(sk, SOCK_DEAD)) {
 149                 pr_err("Attempt to release alive inet socket %p\n", sk);
 150                 return;
 151         }
 152 
 153         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
 154         WARN_ON(refcount_read(&sk->sk_wmem_alloc));
 155         WARN_ON(sk->sk_wmem_queued);
 156         WARN_ON(sk->sk_forward_alloc);
 157 
 158         kfree(rcu_dereference_protected(inet->inet_opt, 1));
 159         dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
 160         dst_release(sk->sk_rx_dst);
 161         sk_refcnt_debug_dec(sk);
 162 }
 163 EXPORT_SYMBOL(inet_sock_destruct);
 164 
 165 /*
 166  *      The routines beyond this point handle the behaviour of an AF_INET
 167  *      socket object. Mostly it punts to the subprotocols of IP to do
 168  *      the work.
 169  */
 170 
 171 /*
 172  *      Automatically bind an unbound socket.
 173  */
 174 
 175 static int inet_autobind(struct sock *sk)
 176 {
 177         struct inet_sock *inet;
 178         /* We may need to bind the socket. */
 179         lock_sock(sk);
 180         inet = inet_sk(sk);
 181         if (!inet->inet_num) {
 182                 if (sk->sk_prot->get_port(sk, 0)) {
 183                         release_sock(sk);
 184                         return -EAGAIN;
 185                 }
 186                 inet->inet_sport = htons(inet->inet_num);
 187         }
 188         release_sock(sk);
 189         return 0;
 190 }
 191 
 192 /*
 193  *      Move a socket into listening state.
 194  */
 195 int inet_listen(struct socket *sock, int backlog)
 196 {
 197         struct sock *sk = sock->sk;
 198         unsigned char old_state;
 199         int err, tcp_fastopen;
 200 
 201         lock_sock(sk);
 202 
 203         err = -EINVAL;
 204         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
 205                 goto out;
 206 
 207         old_state = sk->sk_state;
 208         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 209                 goto out;
 210 
 211         sk->sk_max_ack_backlog = backlog;
 212         /* Really, if the socket is already in listen state
 213          * we can only allow the backlog to be adjusted.
 214          */
 215         if (old_state != TCP_LISTEN) {
 216                 /* Enable TFO w/o requiring TCP_FASTOPEN socket option.
 217                  * Note that only TCP sockets (SOCK_STREAM) will reach here.
 218                  * Also fastopen backlog may already been set via the option
 219                  * because the socket was in TCP_LISTEN state previously but
 220                  * was shutdown() rather than close().
 221                  */
 222                 tcp_fastopen = sock_net(sk)->ipv4.sysctl_tcp_fastopen;
 223                 if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
 224                     (tcp_fastopen & TFO_SERVER_ENABLE) &&
 225                     !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
 226                         fastopen_queue_tune(sk, backlog);
 227                         tcp_fastopen_init_key_once(sock_net(sk));
 228                 }
 229 
 230                 err = inet_csk_listen_start(sk, backlog);
 231                 if (err)
 232                         goto out;
 233                 tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
 234         }
 235         err = 0;
 236 
 237 out:
 238         release_sock(sk);
 239         return err;
 240 }
 241 EXPORT_SYMBOL(inet_listen);
 242 
 243 /*
 244  *      Create an inet socket.
 245  */
 246 
 247 static int inet_create(struct net *net, struct socket *sock, int protocol,
 248                        int kern)
 249 {
 250         struct sock *sk;
 251         struct inet_protosw *answer;
 252         struct inet_sock *inet;
 253         struct proto *answer_prot;
 254         unsigned char answer_flags;
 255         int try_loading_module = 0;
 256         int err;
 257 
 258         if (protocol < 0 || protocol >= IPPROTO_MAX)
 259                 return -EINVAL;
 260 
 261         sock->state = SS_UNCONNECTED;
 262 
 263         /* Look for the requested type/protocol pair. */
 264 lookup_protocol:
 265         err = -ESOCKTNOSUPPORT;
 266         rcu_read_lock();
 267         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 268 
 269                 err = 0;
 270                 /* Check the non-wild match. */
 271                 if (protocol == answer->protocol) {
 272                         if (protocol != IPPROTO_IP)
 273                                 break;
 274                 } else {
 275                         /* Check for the two wild cases. */
 276                         if (IPPROTO_IP == protocol) {
 277                                 protocol = answer->protocol;
 278                                 break;
 279                         }
 280                         if (IPPROTO_IP == answer->protocol)
 281                                 break;
 282                 }
 283                 err = -EPROTONOSUPPORT;
 284         }
 285 
 286         if (unlikely(err)) {
 287                 if (try_loading_module < 2) {
 288                         rcu_read_unlock();
 289                         /*
 290                          * Be more specific, e.g. net-pf-2-proto-132-type-1
 291                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 292                          */
 293                         if (++try_loading_module == 1)
 294                                 request_module("net-pf-%d-proto-%d-type-%d",
 295                                                PF_INET, protocol, sock->type);
 296                         /*
 297                          * Fall back to generic, e.g. net-pf-2-proto-132
 298                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
 299                          */
 300                         else
 301                                 request_module("net-pf-%d-proto-%d",
 302                                                PF_INET, protocol);
 303                         goto lookup_protocol;
 304                 } else
 305                         goto out_rcu_unlock;
 306         }
 307 
 308         err = -EPERM;
 309         if (sock->type == SOCK_RAW && !kern &&
 310             !ns_capable(net->user_ns, CAP_NET_RAW))
 311                 goto out_rcu_unlock;
 312 
 313         sock->ops = answer->ops;
 314         answer_prot = answer->prot;
 315         answer_flags = answer->flags;
 316         rcu_read_unlock();
 317 
 318         WARN_ON(!answer_prot->slab);
 319 
 320         err = -ENOBUFS;
 321         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
 322         if (!sk)
 323                 goto out;
 324 
 325         err = 0;
 326         if (INET_PROTOSW_REUSE & answer_flags)
 327                 sk->sk_reuse = SK_CAN_REUSE;
 328 
 329         inet = inet_sk(sk);
 330         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 331 
 332         inet->nodefrag = 0;
 333 
 334         if (SOCK_RAW == sock->type) {
 335                 inet->inet_num = protocol;
 336                 if (IPPROTO_RAW == protocol)
 337                         inet->hdrincl = 1;
 338         }
 339 
 340         if (net->ipv4.sysctl_ip_no_pmtu_disc)
 341                 inet->pmtudisc = IP_PMTUDISC_DONT;
 342         else
 343                 inet->pmtudisc = IP_PMTUDISC_WANT;
 344 
 345         inet->inet_id = 0;
 346 
 347         sock_init_data(sock, sk);
 348 
 349         sk->sk_destruct    = inet_sock_destruct;
 350         sk->sk_protocol    = protocol;
 351         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 352 
 353         inet->uc_ttl    = -1;
 354         inet->mc_loop   = 1;
 355         inet->mc_ttl    = 1;
 356         inet->mc_all    = 1;
 357         inet->mc_index  = 0;
 358         inet->mc_list   = NULL;
 359         inet->rcv_tos   = 0;
 360 
 361         sk_refcnt_debug_inc(sk);
 362 
 363         if (inet->inet_num) {
 364                 /* It assumes that any protocol which allows
 365                  * the user to assign a number at socket
 366                  * creation time automatically
 367                  * shares.
 368                  */
 369                 inet->inet_sport = htons(inet->inet_num);
 370                 /* Add to protocol hash chains. */
 371                 err = sk->sk_prot->hash(sk);
 372                 if (err) {
 373                         sk_common_release(sk);
 374                         goto out;
 375                 }
 376         }
 377 
 378         if (sk->sk_prot->init) {
 379                 err = sk->sk_prot->init(sk);
 380                 if (err) {
 381                         sk_common_release(sk);
 382                         goto out;
 383                 }
 384         }
 385 
 386         if (!kern) {
 387                 err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
 388                 if (err) {
 389                         sk_common_release(sk);
 390                         goto out;
 391                 }
 392         }
 393 out:
 394         return err;
 395 out_rcu_unlock:
 396         rcu_read_unlock();
 397         goto out;
 398 }
 399 
 400 
 401 /*
 402  *      The peer socket should always be NULL (or else). When we call this
 403  *      function we are destroying the object and from then on nobody
 404  *      should refer to it.
 405  */
 406 int inet_release(struct socket *sock)
 407 {
 408         struct sock *sk = sock->sk;
 409 
 410         if (sk) {
 411                 long timeout;
 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(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 435 {
 436         struct sock *sk = sock->sk;
 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_INET4_BIND(sk, uaddr);
 450         if (err)
 451                 return err;
 452 
 453         return __inet_bind(sk, uaddr, addr_len, false, true);
 454 }
 455 EXPORT_SYMBOL(inet_bind);
 456 
 457 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
 458                 bool force_bind_address_no_port, bool with_lock)
 459 {
 460         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 461         struct inet_sock *inet = inet_sk(sk);
 462         struct net *net = sock_net(sk);
 463         unsigned short snum;
 464         int chk_addr_ret;
 465         u32 tb_id = RT_TABLE_LOCAL;
 466         int err;
 467 
 468         if (addr->sin_family != AF_INET) {
 469                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
 470                  * only if s_addr is INADDR_ANY.
 471                  */
 472                 err = -EAFNOSUPPORT;
 473                 if (addr->sin_family != AF_UNSPEC ||
 474                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
 475                         goto out;
 476         }
 477 
 478         tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
 479         chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
 480 
 481         /* Not specified by any standard per-se, however it breaks too
 482          * many applications when removed.  It is unfortunate since
 483          * allowing applications to make a non-local bind solves
 484          * several problems with systems using dynamic addressing.
 485          * (ie. your servers still start up even if your ISDN link
 486          *  is temporarily down)
 487          */
 488         err = -EADDRNOTAVAIL;
 489         if (!inet_can_nonlocal_bind(net, inet) &&
 490             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
 491             chk_addr_ret != RTN_LOCAL &&
 492             chk_addr_ret != RTN_MULTICAST &&
 493             chk_addr_ret != RTN_BROADCAST)
 494                 goto out;
 495 
 496         snum = ntohs(addr->sin_port);
 497         err = -EACCES;
 498         if (snum && snum < inet_prot_sock(net) &&
 499             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
 500                 goto out;
 501 
 502         /*      We keep a pair of addresses. rcv_saddr is the one
 503          *      used by hash lookups, and saddr is used for transmit.
 504          *
 505          *      In the BSD API these are the same except where it
 506          *      would be illegal to use them (multicast/broadcast) in
 507          *      which case the sending device address is used.
 508          */
 509         if (with_lock)
 510                 lock_sock(sk);
 511 
 512         /* Check these errors (active socket, double bind). */
 513         err = -EINVAL;
 514         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
 515                 goto out_release_sock;
 516 
 517         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
 518         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 519                 inet->inet_saddr = 0;  /* Use device */
 520 
 521         /* Make sure we are allowed to bind here. */
 522         if (snum || !(inet->bind_address_no_port ||
 523                       force_bind_address_no_port)) {
 524                 if (sk->sk_prot->get_port(sk, snum)) {
 525                         inet->inet_saddr = inet->inet_rcv_saddr = 0;
 526                         err = -EADDRINUSE;
 527                         goto out_release_sock;
 528                 }
 529                 err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
 530                 if (err) {
 531                         inet->inet_saddr = inet->inet_rcv_saddr = 0;
 532                         goto out_release_sock;
 533                 }
 534         }
 535 
 536         if (inet->inet_rcv_saddr)
 537                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 538         if (snum)
 539                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 540         inet->inet_sport = htons(inet->inet_num);
 541         inet->inet_daddr = 0;
 542         inet->inet_dport = 0;
 543         sk_dst_reset(sk);
 544         err = 0;
 545 out_release_sock:
 546         if (with_lock)
 547                 release_sock(sk);
 548 out:
 549         return err;
 550 }
 551 
 552 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 553                        int addr_len, int flags)
 554 {
 555         struct sock *sk = sock->sk;
 556         int err;
 557 
 558         if (addr_len < sizeof(uaddr->sa_family))
 559                 return -EINVAL;
 560         if (uaddr->sa_family == AF_UNSPEC)
 561                 return sk->sk_prot->disconnect(sk, flags);
 562 
 563         if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
 564                 err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
 565                 if (err)
 566                         return err;
 567         }
 568 
 569         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
 570                 return -EAGAIN;
 571         return sk->sk_prot->connect(sk, uaddr, addr_len);
 572 }
 573 EXPORT_SYMBOL(inet_dgram_connect);
 574 
 575 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
 576 {
 577         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 578 
 579         add_wait_queue(sk_sleep(sk), &wait);
 580         sk->sk_write_pending += writebias;
 581 
 582         /* Basic assumption: if someone sets sk->sk_err, he _must_
 583          * change state of the socket from TCP_SYN_*.
 584          * Connect() does not allow to get error notifications
 585          * without closing the socket.
 586          */
 587         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 588                 release_sock(sk);
 589                 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
 590                 lock_sock(sk);
 591                 if (signal_pending(current) || !timeo)
 592                         break;
 593         }
 594         remove_wait_queue(sk_sleep(sk), &wait);
 595         sk->sk_write_pending -= writebias;
 596         return timeo;
 597 }
 598 
 599 /*
 600  *      Connect to a remote host. There is regrettably still a little
 601  *      TCP 'magic' in here.
 602  */
 603 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 604                           int addr_len, int flags, int is_sendmsg)
 605 {
 606         struct sock *sk = sock->sk;
 607         int err;
 608         long timeo;
 609 
 610         /*
 611          * uaddr can be NULL and addr_len can be 0 if:
 612          * sk is a TCP fastopen active socket and
 613          * TCP_FASTOPEN_CONNECT sockopt is set and
 614          * we already have a valid cookie for this socket.
 615          * In this case, user can call write() after connect().
 616          * write() will invoke tcp_sendmsg_fastopen() which calls
 617          * __inet_stream_connect().
 618          */
 619         if (uaddr) {
 620                 if (addr_len < sizeof(uaddr->sa_family))
 621                         return -EINVAL;
 622 
 623                 if (uaddr->sa_family == AF_UNSPEC) {
 624                         err = sk->sk_prot->disconnect(sk, flags);
 625                         sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 626                         goto out;
 627                 }
 628         }
 629 
 630         switch (sock->state) {
 631         default:
 632                 err = -EINVAL;
 633                 goto out;
 634         case SS_CONNECTED:
 635                 err = -EISCONN;
 636                 goto out;
 637         case SS_CONNECTING:
 638                 if (inet_sk(sk)->defer_connect)
 639                         err = is_sendmsg ? -EINPROGRESS : -EISCONN;
 640                 else
 641                         err = -EALREADY;
 642                 /* Fall out of switch with err, set for this state */
 643                 break;
 644         case SS_UNCONNECTED:
 645                 err = -EISCONN;
 646                 if (sk->sk_state != TCP_CLOSE)
 647                         goto out;
 648 
 649                 if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
 650                         err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
 651                         if (err)
 652                                 goto out;
 653                 }
 654 
 655                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
 656                 if (err < 0)
 657                         goto out;
 658 
 659                 sock->state = SS_CONNECTING;
 660 
 661                 if (!err && inet_sk(sk)->defer_connect)
 662                         goto out;
 663 
 664                 /* Just entered SS_CONNECTING state; the only
 665                  * difference is that return value in non-blocking
 666                  * case is EINPROGRESS, rather than EALREADY.
 667                  */
 668                 err = -EINPROGRESS;
 669                 break;
 670         }
 671 
 672         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 673 
 674         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
 675                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
 676                                 tcp_sk(sk)->fastopen_req &&
 677                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
 678 
 679                 /* Error code is set above */
 680                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
 681                         goto out;
 682 
 683                 err = sock_intr_errno(timeo);
 684                 if (signal_pending(current))
 685                         goto out;
 686         }
 687 
 688         /* Connection was closed by RST, timeout, ICMP error
 689          * or another process disconnected us.
 690          */
 691         if (sk->sk_state == TCP_CLOSE)
 692                 goto sock_error;
 693 
 694         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
 695          * and error was received after socket entered established state.
 696          * Hence, it is handled normally after connect() return successfully.
 697          */
 698 
 699         sock->state = SS_CONNECTED;
 700         err = 0;
 701 out:
 702         return err;
 703 
 704 sock_error:
 705         err = sock_error(sk) ? : -ECONNABORTED;
 706         sock->state = SS_UNCONNECTED;
 707         if (sk->sk_prot->disconnect(sk, flags))
 708                 sock->state = SS_DISCONNECTING;
 709         goto out;
 710 }
 711 EXPORT_SYMBOL(__inet_stream_connect);
 712 
 713 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 714                         int addr_len, int flags)
 715 {
 716         int err;
 717 
 718         lock_sock(sock->sk);
 719         err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
 720         release_sock(sock->sk);
 721         return err;
 722 }
 723 EXPORT_SYMBOL(inet_stream_connect);
 724 
 725 /*
 726  *      Accept a pending connection. The TCP layer now gives BSD semantics.
 727  */
 728 
 729 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
 730                 bool kern)
 731 {
 732         struct sock *sk1 = sock->sk;
 733         int err = -EINVAL;
 734         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err, kern);
 735 
 736         if (!sk2)
 737                 goto do_err;
 738 
 739         lock_sock(sk2);
 740 
 741         sock_rps_record_flow(sk2);
 742         WARN_ON(!((1 << sk2->sk_state) &
 743                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
 744                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 745 
 746         sock_graft(sk2, newsock);
 747 
 748         newsock->state = SS_CONNECTED;
 749         err = 0;
 750         release_sock(sk2);
 751 do_err:
 752         return err;
 753 }
 754 EXPORT_SYMBOL(inet_accept);
 755 
 756 
 757 /*
 758  *      This does both peername and sockname.
 759  */
 760 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 761                         int peer)
 762 {
 763         struct sock *sk         = sock->sk;
 764         struct inet_sock *inet  = inet_sk(sk);
 765         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
 766 
 767         sin->sin_family = AF_INET;
 768         if (peer) {
 769                 if (!inet->inet_dport ||
 770                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 771                      peer == 1))
 772                         return -ENOTCONN;
 773                 sin->sin_port = inet->inet_dport;
 774                 sin->sin_addr.s_addr = inet->inet_daddr;
 775         } else {
 776                 __be32 addr = inet->inet_rcv_saddr;
 777                 if (!addr)
 778                         addr = inet->inet_saddr;
 779                 sin->sin_port = inet->inet_sport;
 780                 sin->sin_addr.s_addr = addr;
 781         }
 782         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 783         return sizeof(*sin);
 784 }
 785 EXPORT_SYMBOL(inet_getname);
 786 
 787 int inet_send_prepare(struct sock *sk)
 788 {
 789         sock_rps_record_flow(sk);
 790 
 791         /* We may need to bind the socket. */
 792         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 793             inet_autobind(sk))
 794                 return -EAGAIN;
 795 
 796         return 0;
 797 }
 798 EXPORT_SYMBOL_GPL(inet_send_prepare);
 799 
 800 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 801 {
 802         struct sock *sk = sock->sk;
 803 
 804         if (unlikely(inet_send_prepare(sk)))
 805                 return -EAGAIN;
 806 
 807         return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
 808                                sk, msg, size);
 809 }
 810 EXPORT_SYMBOL(inet_sendmsg);
 811 
 812 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 813                       size_t size, int flags)
 814 {
 815         struct sock *sk = sock->sk;
 816 
 817         if (unlikely(inet_send_prepare(sk)))
 818                 return -EAGAIN;
 819 
 820         if (sk->sk_prot->sendpage)
 821                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
 822         return sock_no_sendpage(sock, page, offset, size, flags);
 823 }
 824 EXPORT_SYMBOL(inet_sendpage);
 825 
 826 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
 827                                           size_t, int, int, int *));
 828 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 829                  int flags)
 830 {
 831         struct sock *sk = sock->sk;
 832         int addr_len = 0;
 833         int err;
 834 
 835         if (likely(!(flags & MSG_ERRQUEUE)))
 836                 sock_rps_record_flow(sk);
 837 
 838         err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
 839                               sk, msg, size, flags & MSG_DONTWAIT,
 840                               flags & ~MSG_DONTWAIT, &addr_len);
 841         if (err >= 0)
 842                 msg->msg_namelen = addr_len;
 843         return err;
 844 }
 845 EXPORT_SYMBOL(inet_recvmsg);
 846 
 847 int inet_shutdown(struct socket *sock, int how)
 848 {
 849         struct sock *sk = sock->sk;
 850         int err = 0;
 851 
 852         /* This should really check to make sure
 853          * the socket is a TCP socket. (WHY AC...)
 854          */
 855         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
 856                        1->2 bit 2 snds.
 857                        2->3 */
 858         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
 859                 return -EINVAL;
 860 
 861         lock_sock(sk);
 862         if (sock->state == SS_CONNECTING) {
 863                 if ((1 << sk->sk_state) &
 864                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
 865                         sock->state = SS_DISCONNECTING;
 866                 else
 867                         sock->state = SS_CONNECTED;
 868         }
 869 
 870         switch (sk->sk_state) {
 871         case TCP_CLOSE:
 872                 err = -ENOTCONN;
 873                 /* Hack to wake up other listeners, who can poll for
 874                    EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
 875                 /* fall through */
 876         default:
 877                 sk->sk_shutdown |= how;
 878                 if (sk->sk_prot->shutdown)
 879                         sk->sk_prot->shutdown(sk, how);
 880                 break;
 881 
 882         /* Remaining two branches are temporary solution for missing
 883          * close() in multithreaded environment. It is _not_ a good idea,
 884          * but we have no choice until close() is repaired at VFS level.
 885          */
 886         case TCP_LISTEN:
 887                 if (!(how & RCV_SHUTDOWN))
 888                         break;
 889                 /* fall through */
 890         case TCP_SYN_SENT:
 891                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 892                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
 893                 break;
 894         }
 895 
 896         /* Wake up anyone sleeping in poll. */
 897         sk->sk_state_change(sk);
 898         release_sock(sk);
 899         return err;
 900 }
 901 EXPORT_SYMBOL(inet_shutdown);
 902 
 903 /*
 904  *      ioctl() calls you can issue on an INET socket. Most of these are
 905  *      device configuration and stuff and very rarely used. Some ioctls
 906  *      pass on to the socket itself.
 907  *
 908  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
 909  *      loads the devconfigure module does its configuring and unloads it.
 910  *      There's a good 20K of config code hanging around the kernel.
 911  */
 912 
 913 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 914 {
 915         struct sock *sk = sock->sk;
 916         int err = 0;
 917         struct net *net = sock_net(sk);
 918         void __user *p = (void __user *)arg;
 919         struct ifreq ifr;
 920         struct rtentry rt;
 921 
 922         switch (cmd) {
 923         case SIOCADDRT:
 924         case SIOCDELRT:
 925                 if (copy_from_user(&rt, p, sizeof(struct rtentry)))
 926                         return -EFAULT;
 927                 err = ip_rt_ioctl(net, cmd, &rt);
 928                 break;
 929         case SIOCRTMSG:
 930                 err = -EINVAL;
 931                 break;
 932         case SIOCDARP:
 933         case SIOCGARP:
 934         case SIOCSARP:
 935                 err = arp_ioctl(net, cmd, (void __user *)arg);
 936                 break;
 937         case SIOCGIFADDR:
 938         case SIOCGIFBRDADDR:
 939         case SIOCGIFNETMASK:
 940         case SIOCGIFDSTADDR:
 941         case SIOCGIFPFLAGS:
 942                 if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
 943                         return -EFAULT;
 944                 err = devinet_ioctl(net, cmd, &ifr);
 945                 if (!err && copy_to_user(p, &ifr, sizeof(struct ifreq)))
 946                         err = -EFAULT;
 947                 break;
 948 
 949         case SIOCSIFADDR:
 950         case SIOCSIFBRDADDR:
 951         case SIOCSIFNETMASK:
 952         case SIOCSIFDSTADDR:
 953         case SIOCSIFPFLAGS:
 954         case SIOCSIFFLAGS:
 955                 if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
 956                         return -EFAULT;
 957                 err = devinet_ioctl(net, cmd, &ifr);
 958                 break;
 959         default:
 960                 if (sk->sk_prot->ioctl)
 961                         err = sk->sk_prot->ioctl(sk, cmd, arg);
 962                 else
 963                         err = -ENOIOCTLCMD;
 964                 break;
 965         }
 966         return err;
 967 }
 968 EXPORT_SYMBOL(inet_ioctl);
 969 
 970 #ifdef CONFIG_COMPAT
 971 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 972 {
 973         struct sock *sk = sock->sk;
 974         int err = -ENOIOCTLCMD;
 975 
 976         if (sk->sk_prot->compat_ioctl)
 977                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
 978 
 979         return err;
 980 }
 981 #endif
 982 
 983 const struct proto_ops inet_stream_ops = {
 984         .family            = PF_INET,
 985         .owner             = THIS_MODULE,
 986         .release           = inet_release,
 987         .bind              = inet_bind,
 988         .connect           = inet_stream_connect,
 989         .socketpair        = sock_no_socketpair,
 990         .accept            = inet_accept,
 991         .getname           = inet_getname,
 992         .poll              = tcp_poll,
 993         .ioctl             = inet_ioctl,
 994         .gettstamp         = sock_gettstamp,
 995         .listen            = inet_listen,
 996         .shutdown          = inet_shutdown,
 997         .setsockopt        = sock_common_setsockopt,
 998         .getsockopt        = sock_common_getsockopt,
 999         .sendmsg           = inet_sendmsg,
1000         .recvmsg           = inet_recvmsg,
1001 #ifdef CONFIG_MMU
1002         .mmap              = tcp_mmap,
1003 #endif
1004         .sendpage          = inet_sendpage,
1005         .splice_read       = tcp_splice_read,
1006         .read_sock         = tcp_read_sock,
1007         .sendmsg_locked    = tcp_sendmsg_locked,
1008         .sendpage_locked   = tcp_sendpage_locked,
1009         .peek_len          = tcp_peek_len,
1010 #ifdef CONFIG_COMPAT
1011         .compat_setsockopt = compat_sock_common_setsockopt,
1012         .compat_getsockopt = compat_sock_common_getsockopt,
1013         .compat_ioctl      = inet_compat_ioctl,
1014 #endif
1015         .set_rcvlowat      = tcp_set_rcvlowat,
1016 };
1017 EXPORT_SYMBOL(inet_stream_ops);
1018 
1019 const struct proto_ops inet_dgram_ops = {
1020         .family            = PF_INET,
1021         .owner             = THIS_MODULE,
1022         .release           = inet_release,
1023         .bind              = inet_bind,
1024         .connect           = inet_dgram_connect,
1025         .socketpair        = sock_no_socketpair,
1026         .accept            = sock_no_accept,
1027         .getname           = inet_getname,
1028         .poll              = udp_poll,
1029         .ioctl             = inet_ioctl,
1030         .gettstamp         = sock_gettstamp,
1031         .listen            = sock_no_listen,
1032         .shutdown          = inet_shutdown,
1033         .setsockopt        = sock_common_setsockopt,
1034         .getsockopt        = sock_common_getsockopt,
1035         .sendmsg           = inet_sendmsg,
1036         .recvmsg           = inet_recvmsg,
1037         .mmap              = sock_no_mmap,
1038         .sendpage          = inet_sendpage,
1039         .set_peek_off      = sk_set_peek_off,
1040 #ifdef CONFIG_COMPAT
1041         .compat_setsockopt = compat_sock_common_setsockopt,
1042         .compat_getsockopt = compat_sock_common_getsockopt,
1043         .compat_ioctl      = inet_compat_ioctl,
1044 #endif
1045 };
1046 EXPORT_SYMBOL(inet_dgram_ops);
1047 
1048 /*
1049  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1050  * udp_poll
1051  */
1052 static const struct proto_ops inet_sockraw_ops = {
1053         .family            = PF_INET,
1054         .owner             = THIS_MODULE,
1055         .release           = inet_release,
1056         .bind              = inet_bind,
1057         .connect           = inet_dgram_connect,
1058         .socketpair        = sock_no_socketpair,
1059         .accept            = sock_no_accept,
1060         .getname           = inet_getname,
1061         .poll              = datagram_poll,
1062         .ioctl             = inet_ioctl,
1063         .gettstamp         = sock_gettstamp,
1064         .listen            = sock_no_listen,
1065         .shutdown          = inet_shutdown,
1066         .setsockopt        = sock_common_setsockopt,
1067         .getsockopt        = sock_common_getsockopt,
1068         .sendmsg           = inet_sendmsg,
1069         .recvmsg           = inet_recvmsg,
1070         .mmap              = sock_no_mmap,
1071         .sendpage          = inet_sendpage,
1072 #ifdef CONFIG_COMPAT
1073         .compat_setsockopt = compat_sock_common_setsockopt,
1074         .compat_getsockopt = compat_sock_common_getsockopt,
1075         .compat_ioctl      = inet_compat_ioctl,
1076 #endif
1077 };
1078 
1079 static const struct net_proto_family inet_family_ops = {
1080         .family = PF_INET,
1081         .create = inet_create,
1082         .owner  = THIS_MODULE,
1083 };
1084 
1085 /* Upon startup we insert all the elements in inetsw_array[] into
1086  * the linked list inetsw.
1087  */
1088 static struct inet_protosw inetsw_array[] =
1089 {
1090         {
1091                 .type =       SOCK_STREAM,
1092                 .protocol =   IPPROTO_TCP,
1093                 .prot =       &tcp_prot,
1094                 .ops =        &inet_stream_ops,
1095                 .flags =      INET_PROTOSW_PERMANENT |
1096                               INET_PROTOSW_ICSK,
1097         },
1098 
1099         {
1100                 .type =       SOCK_DGRAM,
1101                 .protocol =   IPPROTO_UDP,
1102                 .prot =       &udp_prot,
1103                 .ops =        &inet_dgram_ops,
1104                 .flags =      INET_PROTOSW_PERMANENT,
1105        },
1106 
1107        {
1108                 .type =       SOCK_DGRAM,
1109                 .protocol =   IPPROTO_ICMP,
1110                 .prot =       &ping_prot,
1111                 .ops =        &inet_sockraw_ops,
1112                 .flags =      INET_PROTOSW_REUSE,
1113        },
1114 
1115        {
1116                .type =       SOCK_RAW,
1117                .protocol =   IPPROTO_IP,        /* wild card */
1118                .prot =       &raw_prot,
1119                .ops =        &inet_sockraw_ops,
1120                .flags =      INET_PROTOSW_REUSE,
1121        }
1122 };
1123 
1124 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1125 
1126 void inet_register_protosw(struct inet_protosw *p)
1127 {
1128         struct list_head *lh;
1129         struct inet_protosw *answer;
1130         int protocol = p->protocol;
1131         struct list_head *last_perm;
1132 
1133         spin_lock_bh(&inetsw_lock);
1134 
1135         if (p->type >= SOCK_MAX)
1136                 goto out_illegal;
1137 
1138         /* If we are trying to override a permanent protocol, bail. */
1139         last_perm = &inetsw[p->type];
1140         list_for_each(lh, &inetsw[p->type]) {
1141                 answer = list_entry(lh, struct inet_protosw, list);
1142                 /* Check only the non-wild match. */
1143                 if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1144                         break;
1145                 if (protocol == answer->protocol)
1146                         goto out_permanent;
1147                 last_perm = lh;
1148         }
1149 
1150         /* Add the new entry after the last permanent entry if any, so that
1151          * the new entry does not override a permanent entry when matched with
1152          * a wild-card protocol. But it is allowed to override any existing
1153          * non-permanent entry.  This means that when we remove this entry, the
1154          * system automatically returns to the old behavior.
1155          */
1156         list_add_rcu(&p->list, last_perm);
1157 out:
1158         spin_unlock_bh(&inetsw_lock);
1159 
1160         return;
1161 
1162 out_permanent:
1163         pr_err("Attempt to override permanent protocol %d\n", protocol);
1164         goto out;
1165 
1166 out_illegal:
1167         pr_err("Ignoring attempt to register invalid socket type %d\n",
1168                p->type);
1169         goto out;
1170 }
1171 EXPORT_SYMBOL(inet_register_protosw);
1172 
1173 void inet_unregister_protosw(struct inet_protosw *p)
1174 {
1175         if (INET_PROTOSW_PERMANENT & p->flags) {
1176                 pr_err("Attempt to unregister permanent protocol %d\n",
1177                        p->protocol);
1178         } else {
1179                 spin_lock_bh(&inetsw_lock);
1180                 list_del_rcu(&p->list);
1181                 spin_unlock_bh(&inetsw_lock);
1182 
1183                 synchronize_net();
1184         }
1185 }
1186 EXPORT_SYMBOL(inet_unregister_protosw);
1187 
1188 static int inet_sk_reselect_saddr(struct sock *sk)
1189 {
1190         struct inet_sock *inet = inet_sk(sk);
1191         __be32 old_saddr = inet->inet_saddr;
1192         __be32 daddr = inet->inet_daddr;
1193         struct flowi4 *fl4;
1194         struct rtable *rt;
1195         __be32 new_saddr;
1196         struct ip_options_rcu *inet_opt;
1197 
1198         inet_opt = rcu_dereference_protected(inet->inet_opt,
1199                                              lockdep_sock_is_held(sk));
1200         if (inet_opt && inet_opt->opt.srr)
1201                 daddr = inet_opt->opt.faddr;
1202 
1203         /* Query new route. */
1204         fl4 = &inet->cork.fl.u.ip4;
1205         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1206                               sk->sk_bound_dev_if, sk->sk_protocol,
1207                               inet->inet_sport, inet->inet_dport, sk);
1208         if (IS_ERR(rt))
1209                 return PTR_ERR(rt);
1210 
1211         sk_setup_caps(sk, &rt->dst);
1212 
1213         new_saddr = fl4->saddr;
1214 
1215         if (new_saddr == old_saddr)
1216                 return 0;
1217 
1218         if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) {
1219                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1220                         __func__, &old_saddr, &new_saddr);
1221         }
1222 
1223         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1224 
1225         /*
1226          * XXX The only one ugly spot where we need to
1227          * XXX really change the sockets identity after
1228          * XXX it has entered the hashes. -DaveM
1229          *
1230          * Besides that, it does not check for connection
1231          * uniqueness. Wait for troubles.
1232          */
1233         return __sk_prot_rehash(sk);
1234 }
1235 
1236 int inet_sk_rebuild_header(struct sock *sk)
1237 {
1238         struct inet_sock *inet = inet_sk(sk);
1239         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1240         __be32 daddr;
1241         struct ip_options_rcu *inet_opt;
1242         struct flowi4 *fl4;
1243         int err;
1244 
1245         /* Route is OK, nothing to do. */
1246         if (rt)
1247                 return 0;
1248 
1249         /* Reroute. */
1250         rcu_read_lock();
1251         inet_opt = rcu_dereference(inet->inet_opt);
1252         daddr = inet->inet_daddr;
1253         if (inet_opt && inet_opt->opt.srr)
1254                 daddr = inet_opt->opt.faddr;
1255         rcu_read_unlock();
1256         fl4 = &inet->cork.fl.u.ip4;
1257         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1258                                    inet->inet_dport, inet->inet_sport,
1259                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1260                                    sk->sk_bound_dev_if);
1261         if (!IS_ERR(rt)) {
1262                 err = 0;
1263                 sk_setup_caps(sk, &rt->dst);
1264         } else {
1265                 err = PTR_ERR(rt);
1266 
1267                 /* Routing failed... */
1268                 sk->sk_route_caps = 0;
1269                 /*
1270                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1271                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1272                  */
1273                 if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr ||
1274                     sk->sk_state != TCP_SYN_SENT ||
1275                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1276                     (err = inet_sk_reselect_saddr(sk)) != 0)
1277                         sk->sk_err_soft = -err;
1278         }
1279 
1280         return err;
1281 }
1282 EXPORT_SYMBOL(inet_sk_rebuild_header);
1283 
1284 void inet_sk_set_state(struct sock *sk, int state)
1285 {
1286         trace_inet_sock_set_state(sk, sk->sk_state, state);
1287         sk->sk_state = state;
1288 }
1289 EXPORT_SYMBOL(inet_sk_set_state);
1290 
1291 void inet_sk_state_store(struct sock *sk, int newstate)
1292 {
1293         trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1294         smp_store_release(&sk->sk_state, newstate);
1295 }
1296 
1297 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1298                                  netdev_features_t features)
1299 {
1300         bool udpfrag = false, fixedid = false, gso_partial, encap;
1301         struct sk_buff *segs = ERR_PTR(-EINVAL);
1302         const struct net_offload *ops;
1303         unsigned int offset = 0;
1304         struct iphdr *iph;
1305         int proto, tot_len;
1306         int nhoff;
1307         int ihl;
1308         int id;
1309 
1310         skb_reset_network_header(skb);
1311         nhoff = skb_network_header(skb) - skb_mac_header(skb);
1312         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1313                 goto out;
1314 
1315         iph = ip_hdr(skb);
1316         ihl = iph->ihl * 4;
1317         if (ihl < sizeof(*iph))
1318                 goto out;
1319 
1320         id = ntohs(iph->id);
1321         proto = iph->protocol;
1322 
1323         /* Warning: after this point, iph might be no longer valid */
1324         if (unlikely(!pskb_may_pull(skb, ihl)))
1325                 goto out;
1326         __skb_pull(skb, ihl);
1327 
1328         encap = SKB_GSO_CB(skb)->encap_level > 0;
1329         if (encap)
1330                 features &= skb->dev->hw_enc_features;
1331         SKB_GSO_CB(skb)->encap_level += ihl;
1332 
1333         skb_reset_transport_header(skb);
1334 
1335         segs = ERR_PTR(-EPROTONOSUPPORT);
1336 
1337         if (!skb->encapsulation || encap) {
1338                 udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1339                 fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1340 
1341                 /* fixed ID is invalid if DF bit is not set */
1342                 if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1343                         goto out;
1344         }
1345 
1346         ops = rcu_dereference(inet_offloads[proto]);
1347         if (likely(ops && ops->callbacks.gso_segment))
1348                 segs = ops->callbacks.gso_segment(skb, features);
1349 
1350         if (IS_ERR_OR_NULL(segs))
1351                 goto out;
1352 
1353         gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1354 
1355         skb = segs;
1356         do {
1357                 iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1358                 if (udpfrag) {
1359                         iph->frag_off = htons(offset >> 3);
1360                         if (skb->next)
1361                                 iph->frag_off |= htons(IP_MF);
1362                         offset += skb->len - nhoff - ihl;
1363                         tot_len = skb->len - nhoff;
1364                 } else if (skb_is_gso(skb)) {
1365                         if (!fixedid) {
1366                                 iph->id = htons(id);
1367                                 id += skb_shinfo(skb)->gso_segs;
1368                         }
1369 
1370                         if (gso_partial)
1371                                 tot_len = skb_shinfo(skb)->gso_size +
1372                                           SKB_GSO_CB(skb)->data_offset +
1373                                           skb->head - (unsigned char *)iph;
1374                         else
1375                                 tot_len = skb->len - nhoff;
1376                 } else {
1377                         if (!fixedid)
1378                                 iph->id = htons(id++);
1379                         tot_len = skb->len - nhoff;
1380                 }
1381                 iph->tot_len = htons(tot_len);
1382                 ip_send_check(iph);
1383                 if (encap)
1384                         skb_reset_inner_headers(skb);
1385                 skb->network_header = (u8 *)iph - skb->head;
1386                 skb_reset_mac_len(skb);
1387         } while ((skb = skb->next));
1388 
1389 out:
1390         return segs;
1391 }
1392 EXPORT_SYMBOL(inet_gso_segment);
1393 
1394 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1395                                         netdev_features_t features)
1396 {
1397         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1398                 return ERR_PTR(-EINVAL);
1399 
1400         return inet_gso_segment(skb, features);
1401 }
1402 
1403 INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *,
1404                                                            struct sk_buff *));
1405 INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
1406                                                            struct sk_buff *));
1407 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1408 {
1409         const struct net_offload *ops;
1410         struct sk_buff *pp = NULL;
1411         const struct iphdr *iph;
1412         struct sk_buff *p;
1413         unsigned int hlen;
1414         unsigned int off;
1415         unsigned int id;
1416         int flush = 1;
1417         int proto;
1418 
1419         off = skb_gro_offset(skb);
1420         hlen = off + sizeof(*iph);
1421         iph = skb_gro_header_fast(skb, off);
1422         if (skb_gro_header_hard(skb, hlen)) {
1423                 iph = skb_gro_header_slow(skb, hlen, off);
1424                 if (unlikely(!iph))
1425                         goto out;
1426         }
1427 
1428         proto = iph->protocol;
1429 
1430         rcu_read_lock();
1431         ops = rcu_dereference(inet_offloads[proto]);
1432         if (!ops || !ops->callbacks.gro_receive)
1433                 goto out_unlock;
1434 
1435         if (*(u8 *)iph != 0x45)
1436                 goto out_unlock;
1437 
1438         if (ip_is_fragment(iph))
1439                 goto out_unlock;
1440 
1441         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1442                 goto out_unlock;
1443 
1444         id = ntohl(*(__be32 *)&iph->id);
1445         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1446         id >>= 16;
1447 
1448         list_for_each_entry(p, head, list) {
1449                 struct iphdr *iph2;
1450                 u16 flush_id;
1451 
1452                 if (!NAPI_GRO_CB(p)->same_flow)
1453                         continue;
1454 
1455                 iph2 = (struct iphdr *)(p->data + off);
1456                 /* The above works because, with the exception of the top
1457                  * (inner most) layer, we only aggregate pkts with the same
1458                  * hdr length so all the hdrs we'll need to verify will start
1459                  * at the same offset.
1460                  */
1461                 if ((iph->protocol ^ iph2->protocol) |
1462                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1463                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1464                         NAPI_GRO_CB(p)->same_flow = 0;
1465                         continue;
1466                 }
1467 
1468                 /* All fields must match except length and checksum. */
1469                 NAPI_GRO_CB(p)->flush |=
1470                         (iph->ttl ^ iph2->ttl) |
1471                         (iph->tos ^ iph2->tos) |
1472                         ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1473 
1474                 NAPI_GRO_CB(p)->flush |= flush;
1475 
1476                 /* We need to store of the IP ID check to be included later
1477                  * when we can verify that this packet does in fact belong
1478                  * to a given flow.
1479                  */
1480                 flush_id = (u16)(id - ntohs(iph2->id));
1481 
1482                 /* This bit of code makes it much easier for us to identify
1483                  * the cases where we are doing atomic vs non-atomic IP ID
1484                  * checks.  Specifically an atomic check can return IP ID
1485                  * values 0 - 0xFFFF, while a non-atomic check can only
1486                  * return 0 or 0xFFFF.
1487                  */
1488                 if (!NAPI_GRO_CB(p)->is_atomic ||
1489                     !(iph->frag_off & htons(IP_DF))) {
1490                         flush_id ^= NAPI_GRO_CB(p)->count;
1491                         flush_id = flush_id ? 0xFFFF : 0;
1492                 }
1493 
1494                 /* If the previous IP ID value was based on an atomic
1495                  * datagram we can overwrite the value and ignore it.
1496                  */
1497                 if (NAPI_GRO_CB(skb)->is_atomic)
1498                         NAPI_GRO_CB(p)->flush_id = flush_id;
1499                 else
1500                         NAPI_GRO_CB(p)->flush_id |= flush_id;
1501         }
1502 
1503         NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1504         NAPI_GRO_CB(skb)->flush |= flush;
1505         skb_set_network_header(skb, off);
1506         /* The above will be needed by the transport layer if there is one
1507          * immediately following this IP hdr.
1508          */
1509 
1510         /* Note : No need to call skb_gro_postpull_rcsum() here,
1511          * as we already checked checksum over ipv4 header was 0
1512          */
1513         skb_gro_pull(skb, sizeof(*iph));
1514         skb_set_transport_header(skb, skb_gro_offset(skb));
1515 
1516         pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1517                                        ops->callbacks.gro_receive, head, skb);
1518 
1519 out_unlock:
1520         rcu_read_unlock();
1521 
1522 out:
1523         skb_gro_flush_final(skb, pp, flush);
1524 
1525         return pp;
1526 }
1527 EXPORT_SYMBOL(inet_gro_receive);
1528 
1529 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1530                                         struct sk_buff *skb)
1531 {
1532         if (NAPI_GRO_CB(skb)->encap_mark) {
1533                 NAPI_GRO_CB(skb)->flush = 1;
1534                 return NULL;
1535         }
1536 
1537         NAPI_GRO_CB(skb)->encap_mark = 1;
1538 
1539         return inet_gro_receive(head, skb);
1540 }
1541 
1542 #define SECONDS_PER_DAY 86400
1543 
1544 /* inet_current_timestamp - Return IP network timestamp
1545  *
1546  * Return milliseconds since midnight in network byte order.
1547  */
1548 __be32 inet_current_timestamp(void)
1549 {
1550         u32 secs;
1551         u32 msecs;
1552         struct timespec64 ts;
1553 
1554         ktime_get_real_ts64(&ts);
1555 
1556         /* Get secs since midnight. */
1557         (void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1558         /* Convert to msecs. */
1559         msecs = secs * MSEC_PER_SEC;
1560         /* Convert nsec to msec. */
1561         msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1562 
1563         /* Convert to network byte order. */
1564         return htonl(msecs);
1565 }
1566 EXPORT_SYMBOL(inet_current_timestamp);
1567 
1568 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1569 {
1570         if (sk->sk_family == AF_INET)
1571                 return ip_recv_error(sk, msg, len, addr_len);
1572 #if IS_ENABLED(CONFIG_IPV6)
1573         if (sk->sk_family == AF_INET6)
1574                 return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1575 #endif
1576         return -EINVAL;
1577 }
1578 
1579 INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *, int));
1580 INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
1581 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1582 {
1583         __be16 newlen = htons(skb->len - nhoff);
1584         struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1585         const struct net_offload *ops;
1586         int proto = iph->protocol;
1587         int err = -ENOSYS;
1588 
1589         if (skb->encapsulation) {
1590                 skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1591                 skb_set_inner_network_header(skb, nhoff);
1592         }
1593 
1594         csum_replace2(&iph->check, iph->tot_len, newlen);
1595         iph->tot_len = newlen;
1596 
1597         rcu_read_lock();
1598         ops = rcu_dereference(inet_offloads[proto]);
1599         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1600                 goto out_unlock;
1601 
1602         /* Only need to add sizeof(*iph) to get to the next hdr below
1603          * because any hdr with option will have been flushed in
1604          * inet_gro_receive().
1605          */
1606         err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1607                               tcp4_gro_complete, udp4_gro_complete,
1608                               skb, nhoff + sizeof(*iph));
1609 
1610 out_unlock:
1611         rcu_read_unlock();
1612 
1613         return err;
1614 }
1615 EXPORT_SYMBOL(inet_gro_complete);
1616 
1617 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1618 {
1619         skb->encapsulation = 1;
1620         skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1621         return inet_gro_complete(skb, nhoff);
1622 }
1623 
1624 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1625                          unsigned short type, unsigned char protocol,
1626                          struct net *net)
1627 {
1628         struct socket *sock;
1629         int rc = sock_create_kern(net, family, type, protocol, &sock);
1630 
1631         if (rc == 0) {
1632                 *sk = sock->sk;
1633                 (*sk)->sk_allocation = GFP_ATOMIC;
1634                 /*
1635                  * Unhash it so that IP input processing does not even see it,
1636                  * we do not wish this socket to see incoming packets.
1637                  */
1638                 (*sk)->sk_prot->unhash(*sk);
1639         }
1640         return rc;
1641 }
1642 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1643 
1644 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1645 {
1646         return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1647 }
1648 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1649 
1650 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1651 {
1652         unsigned long res = 0;
1653         int i;
1654 
1655         for_each_possible_cpu(i)
1656                 res += snmp_get_cpu_field(mib, i, offt);
1657         return res;
1658 }
1659 EXPORT_SYMBOL_GPL(snmp_fold_field);
1660 
1661 #if BITS_PER_LONG==32
1662 
1663 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1664                          size_t syncp_offset)
1665 {
1666         void *bhptr;
1667         struct u64_stats_sync *syncp;
1668         u64 v;
1669         unsigned int start;
1670 
1671         bhptr = per_cpu_ptr(mib, cpu);
1672         syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1673         do {
1674                 start = u64_stats_fetch_begin_irq(syncp);
1675                 v = *(((u64 *)bhptr) + offt);
1676         } while (u64_stats_fetch_retry_irq(syncp, start));
1677 
1678         return v;
1679 }
1680 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1681 
1682 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1683 {
1684         u64 res = 0;
1685         int cpu;
1686 
1687         for_each_possible_cpu(cpu) {
1688                 res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1689         }
1690         return res;
1691 }
1692 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1693 #endif
1694 
1695 #ifdef CONFIG_IP_MULTICAST
1696 static const struct net_protocol igmp_protocol = {
1697         .handler =      igmp_rcv,
1698         .netns_ok =     1,
1699 };
1700 #endif
1701 
1702 /* thinking of making this const? Don't.
1703  * early_demux can change based on sysctl.
1704  */
1705 static struct net_protocol tcp_protocol = {
1706         .early_demux    =       tcp_v4_early_demux,
1707         .early_demux_handler =  tcp_v4_early_demux,
1708         .handler        =       tcp_v4_rcv,
1709         .err_handler    =       tcp_v4_err,
1710         .no_policy      =       1,
1711         .netns_ok       =       1,
1712         .icmp_strict_tag_validation = 1,
1713 };
1714 
1715 /* thinking of making this const? Don't.
1716  * early_demux can change based on sysctl.
1717  */
1718 static struct net_protocol udp_protocol = {
1719         .early_demux =  udp_v4_early_demux,
1720         .early_demux_handler =  udp_v4_early_demux,
1721         .handler =      udp_rcv,
1722         .err_handler =  udp_err,
1723         .no_policy =    1,
1724         .netns_ok =     1,
1725 };
1726 
1727 static const struct net_protocol icmp_protocol = {
1728         .handler =      icmp_rcv,
1729         .err_handler =  icmp_err,
1730         .no_policy =    1,
1731         .netns_ok =     1,
1732 };
1733 
1734 static __net_init int ipv4_mib_init_net(struct net *net)
1735 {
1736         int i;
1737 
1738         net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1739         if (!net->mib.tcp_statistics)
1740                 goto err_tcp_mib;
1741         net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1742         if (!net->mib.ip_statistics)
1743                 goto err_ip_mib;
1744 
1745         for_each_possible_cpu(i) {
1746                 struct ipstats_mib *af_inet_stats;
1747                 af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1748                 u64_stats_init(&af_inet_stats->syncp);
1749         }
1750 
1751         net->mib.net_statistics = alloc_percpu(struct linux_mib);
1752         if (!net->mib.net_statistics)
1753                 goto err_net_mib;
1754         net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1755         if (!net->mib.udp_statistics)
1756                 goto err_udp_mib;
1757         net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1758         if (!net->mib.udplite_statistics)
1759                 goto err_udplite_mib;
1760         net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1761         if (!net->mib.icmp_statistics)
1762                 goto err_icmp_mib;
1763         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1764                                               GFP_KERNEL);
1765         if (!net->mib.icmpmsg_statistics)
1766                 goto err_icmpmsg_mib;
1767 
1768         tcp_mib_init(net);
1769         return 0;
1770 
1771 err_icmpmsg_mib:
1772         free_percpu(net->mib.icmp_statistics);
1773 err_icmp_mib:
1774         free_percpu(net->mib.udplite_statistics);
1775 err_udplite_mib:
1776         free_percpu(net->mib.udp_statistics);
1777 err_udp_mib:
1778         free_percpu(net->mib.net_statistics);
1779 err_net_mib:
1780         free_percpu(net->mib.ip_statistics);
1781 err_ip_mib:
1782         free_percpu(net->mib.tcp_statistics);
1783 err_tcp_mib:
1784         return -ENOMEM;
1785 }
1786 
1787 static __net_exit void ipv4_mib_exit_net(struct net *net)
1788 {
1789         kfree(net->mib.icmpmsg_statistics);
1790         free_percpu(net->mib.icmp_statistics);
1791         free_percpu(net->mib.udplite_statistics);
1792         free_percpu(net->mib.udp_statistics);
1793         free_percpu(net->mib.net_statistics);
1794         free_percpu(net->mib.ip_statistics);
1795         free_percpu(net->mib.tcp_statistics);
1796 }
1797 
1798 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1799         .init = ipv4_mib_init_net,
1800         .exit = ipv4_mib_exit_net,
1801 };
1802 
1803 static int __init init_ipv4_mibs(void)
1804 {
1805         return register_pernet_subsys(&ipv4_mib_ops);
1806 }
1807 
1808 static __net_init int inet_init_net(struct net *net)
1809 {
1810         /*
1811          * Set defaults for local port range
1812          */
1813         seqlock_init(&net->ipv4.ip_local_ports.lock);
1814         net->ipv4.ip_local_ports.range[0] =  32768;
1815         net->ipv4.ip_local_ports.range[1] =  60999;
1816 
1817         seqlock_init(&net->ipv4.ping_group_range.lock);
1818         /*
1819          * Sane defaults - nobody may create ping sockets.
1820          * Boot scripts should set this to distro-specific group.
1821          */
1822         net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1823         net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1824 
1825         /* Default values for sysctl-controlled parameters.
1826          * We set them here, in case sysctl is not compiled.
1827          */
1828         net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1829         net->ipv4.sysctl_ip_fwd_update_priority = 1;
1830         net->ipv4.sysctl_ip_dynaddr = 0;
1831         net->ipv4.sysctl_ip_early_demux = 1;
1832         net->ipv4.sysctl_udp_early_demux = 1;
1833         net->ipv4.sysctl_tcp_early_demux = 1;
1834 #ifdef CONFIG_SYSCTL
1835         net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1836 #endif
1837 
1838         /* Some igmp sysctl, whose values are always used */
1839         net->ipv4.sysctl_igmp_max_memberships = 20;
1840         net->ipv4.sysctl_igmp_max_msf = 10;
1841         /* IGMP reports for link-local multicast groups are enabled by default */
1842         net->ipv4.sysctl_igmp_llm_reports = 1;
1843         net->ipv4.sysctl_igmp_qrv = 2;
1844 
1845         return 0;
1846 }
1847 
1848 static __net_initdata struct pernet_operations af_inet_ops = {
1849         .init = inet_init_net,
1850 };
1851 
1852 static int __init init_inet_pernet_ops(void)
1853 {
1854         return register_pernet_subsys(&af_inet_ops);
1855 }
1856 
1857 static int ipv4_proc_init(void);
1858 
1859 /*
1860  *      IP protocol layer initialiser
1861  */
1862 
1863 static struct packet_offload ip_packet_offload __read_mostly = {
1864         .type = cpu_to_be16(ETH_P_IP),
1865         .callbacks = {
1866                 .gso_segment = inet_gso_segment,
1867                 .gro_receive = inet_gro_receive,
1868                 .gro_complete = inet_gro_complete,
1869         },
1870 };
1871 
1872 static const struct net_offload ipip_offload = {
1873         .callbacks = {
1874                 .gso_segment    = ipip_gso_segment,
1875                 .gro_receive    = ipip_gro_receive,
1876                 .gro_complete   = ipip_gro_complete,
1877         },
1878 };
1879 
1880 static int __init ipip_offload_init(void)
1881 {
1882         return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1883 }
1884 
1885 static int __init ipv4_offload_init(void)
1886 {
1887         /*
1888          * Add offloads
1889          */
1890         if (udpv4_offload_init() < 0)
1891                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1892         if (tcpv4_offload_init() < 0)
1893                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1894         if (ipip_offload_init() < 0)
1895                 pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1896 
1897         dev_add_offload(&ip_packet_offload);
1898         return 0;
1899 }
1900 
1901 fs_initcall(ipv4_offload_init);
1902 
1903 static struct packet_type ip_packet_type __read_mostly = {
1904         .type = cpu_to_be16(ETH_P_IP),
1905         .func = ip_rcv,
1906         .list_func = ip_list_rcv,
1907 };
1908 
1909 static int __init inet_init(void)
1910 {
1911         struct inet_protosw *q;
1912         struct list_head *r;
1913         int rc = -EINVAL;
1914 
1915         sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1916 
1917         rc = proto_register(&tcp_prot, 1);
1918         if (rc)
1919                 goto out;
1920 
1921         rc = proto_register(&udp_prot, 1);
1922         if (rc)
1923                 goto out_unregister_tcp_proto;
1924 
1925         rc = proto_register(&raw_prot, 1);
1926         if (rc)
1927                 goto out_unregister_udp_proto;
1928 
1929         rc = proto_register(&ping_prot, 1);
1930         if (rc)
1931                 goto out_unregister_raw_proto;
1932 
1933         /*
1934          *      Tell SOCKET that we are alive...
1935          */
1936 
1937         (void)sock_register(&inet_family_ops);
1938 
1939 #ifdef CONFIG_SYSCTL
1940         ip_static_sysctl_init();
1941 #endif
1942 
1943         /*
1944          *      Add all the base protocols.
1945          */
1946 
1947         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1948                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1949         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1950                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1951         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1952                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1953 #ifdef CONFIG_IP_MULTICAST
1954         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1955                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1956 #endif
1957 
1958         /* Register the socket-side information for inet_create. */
1959         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1960                 INIT_LIST_HEAD(r);
1961 
1962         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1963                 inet_register_protosw(q);
1964 
1965         /*
1966          *      Set the ARP module up
1967          */
1968 
1969         arp_init();
1970 
1971         /*
1972          *      Set the IP module up
1973          */
1974 
1975         ip_init();
1976 
1977         /* Setup TCP slab cache for open requests. */
1978         tcp_init();
1979 
1980         /* Setup UDP memory threshold */
1981         udp_init();
1982 
1983         /* Add UDP-Lite (RFC 3828) */
1984         udplite4_register();
1985 
1986         raw_init();
1987 
1988         ping_init();
1989 
1990         /*
1991          *      Set the ICMP layer up
1992          */
1993 
1994         if (icmp_init() < 0)
1995                 panic("Failed to create the ICMP control socket.\n");
1996 
1997         /*
1998          *      Initialise the multicast router
1999          */
2000 #if defined(CONFIG_IP_MROUTE)
2001         if (ip_mr_init())
2002                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2003 #endif
2004 
2005         if (init_inet_pernet_ops())
2006                 pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2007         /*
2008          *      Initialise per-cpu ipv4 mibs
2009          */
2010 
2011         if (init_ipv4_mibs())
2012                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
2013 
2014         ipv4_proc_init();
2015 
2016         ipfrag_init();
2017 
2018         dev_add_pack(&ip_packet_type);
2019 
2020         ip_tunnel_core_init();
2021 
2022         rc = 0;
2023 out:
2024         return rc;
2025 out_unregister_raw_proto:
2026         proto_unregister(&raw_prot);
2027 out_unregister_udp_proto:
2028         proto_unregister(&udp_prot);
2029 out_unregister_tcp_proto:
2030         proto_unregister(&tcp_prot);
2031         goto out;
2032 }
2033 
2034 fs_initcall(inet_init);
2035 
2036 /* ------------------------------------------------------------------------ */
2037 
2038 #ifdef CONFIG_PROC_FS
2039 static int __init ipv4_proc_init(void)
2040 {
2041         int rc = 0;
2042 
2043         if (raw_proc_init())
2044                 goto out_raw;
2045         if (tcp4_proc_init())
2046                 goto out_tcp;
2047         if (udp4_proc_init())
2048                 goto out_udp;
2049         if (ping_proc_init())
2050                 goto out_ping;
2051         if (ip_misc_proc_init())
2052                 goto out_misc;
2053 out:
2054         return rc;
2055 out_misc:
2056         ping_proc_exit();
2057 out_ping:
2058         udp4_proc_exit();
2059 out_udp:
2060         tcp4_proc_exit();
2061 out_tcp:
2062         raw_proc_exit();
2063 out_raw:
2064         rc = -ENOMEM;
2065         goto out;
2066 }
2067 
2068 #else /* CONFIG_PROC_FS */
2069 static int __init ipv4_proc_init(void)
2070 {
2071         return 0;
2072 }
2073 #endif /* CONFIG_PROC_FS */
/* [<][>][^][v][top][bottom][index][help] */
root/net/ipv4/af_inet.c

DEFINITIONS
