net/ipv6/af_inet6.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      PF_INET6 socket protocol family
   4  *      Linux INET6 implementation
   5  *
   6  *      Authors:
   7  *      Pedro Roque             <roque@di.fc.ul.pt>
   8  *
   9  *      Adapted from linux/net/ipv4/af_inet.c
  10  *
  11  *      Fixes:
  12  *      piggy, Karl Knutson     :       Socket protocol table
  13  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  14  *      Arnaldo Melo            :       check proc_net_create return, cleanups
  15  */
  16
  17 #define pr_fmt(fmt) "IPv6: " fmt
  18
  19 #include <linux/module.h>
  20 #include <linux/capability.h>
  21 #include <linux/errno.h>
  22 #include <linux/types.h>
  23 #include <linux/socket.h>
  24 #include <linux/in.h>
  25 #include <linux/kernel.h>
  26 #include <linux/timer.h>
  27 #include <linux/string.h>
  28 #include <linux/sockios.h>
  29 #include <linux/net.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/mm.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/proc_fs.h>
  34 #include <linux/stat.h>
  35 #include <linux/init.h>
  36 #include <linux/slab.h>
  37
  38 #include <linux/inet.h>
  39 #include <linux/netdevice.h>
  40 #include <linux/icmpv6.h>
  41 #include <linux/netfilter_ipv6.h>
  42
  43 #include <net/ip.h>
  44 #include <net/ipv6.h>
  45 #include <net/udp.h>
  46 #include <net/udplite.h>
  47 #include <net/tcp.h>
  48 #include <net/ping.h>
  49 #include <net/protocol.h>
  50 #include <net/inet_common.h>
  51 #include <net/route.h>
  52 #include <net/transp_v6.h>
  53 #include <net/ip6_route.h>
  54 #include <net/addrconf.h>
  55 #include <net/ipv6_stubs.h>
  56 #include <net/ndisc.h>
  57 #ifdef CONFIG_IPV6_TUNNEL
  58 #include <net/ip6_tunnel.h>
  59 #endif
  60 #include <net/calipso.h>
  61 #include <net/seg6.h>
  62
  63 #include <linux/uaccess.h>
  64 #include <linux/mroute6.h>
  65
  66 #include "ip6_offload.h"
  67
  68 MODULE_AUTHOR("Cast of dozens");
  69 MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
  70 MODULE_LICENSE("GPL");
  71
  72 /* The inetsw6 table contains everything that inet6_create needs to
  73  * build a new socket.
  74  */
  75 static struct list_head inetsw6[SOCK_MAX];
  76 static DEFINE_SPINLOCK(inetsw6_lock);
  77
  78 struct ipv6_params ipv6_defaults = {
  79         .disable_ipv6 = 0,
  80         .autoconf = 1,
  81 };
  82
  83 static int disable_ipv6_mod;
  84
  85 module_param_named(disable, disable_ipv6_mod, int, 0444);
  86 MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional");
  87
  88 module_param_named(disable_ipv6, ipv6_defaults.disable_ipv6, int, 0444);
  89 MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces");
  90
  91 module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444);
  92 MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces");
  93
  94 bool ipv6_mod_enabled(void)
  95 {
  96         return disable_ipv6_mod == 0;
  97 }
  98 EXPORT_SYMBOL_GPL(ipv6_mod_enabled);
  99
 100 static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
 101 {
 102         const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo);
 103
 104         return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
 105 }
 106
 107 static int inet6_create(struct net *net, struct socket *sock, int protocol,
 108                         int kern)
 109 {
 110         struct inet_sock *inet;
 111         struct ipv6_pinfo *np;
 112         struct sock *sk;
 113         struct inet_protosw *answer;
 114         struct proto *answer_prot;
 115         unsigned char answer_flags;
 116         int try_loading_module = 0;
 117         int err;
 118
 119         if (protocol < 0 || protocol >= IPPROTO_MAX)
 120                 return -EINVAL;
 121
 122         /* Look for the requested type/protocol pair. */
 123 lookup_protocol:
 124         err = -ESOCKTNOSUPPORT;
 125         rcu_read_lock();
 126         list_for_each_entry_rcu(answer, &inetsw6[sock->type], list) {
 127
 128                 err = 0;
 129                 /* Check the non-wild match. */
 130                 if (protocol == answer->protocol) {
 131                         if (protocol != IPPROTO_IP)
 132                                 break;
 133                 } else {
 134                         /* Check for the two wild cases. */
 135                         if (IPPROTO_IP == protocol) {
 136                                 protocol = answer->protocol;
 137                                 break;
 138                         }
 139                         if (IPPROTO_IP == answer->protocol)
 140                                 break;
 141                 }
 142                 err = -EPROTONOSUPPORT;
 143         }
 144
 145         if (err) {
 146                 if (try_loading_module < 2) {
 147                         rcu_read_unlock();
 148                         /*
 149                          * Be more specific, e.g. net-pf-10-proto-132-type-1
 150                          * (net-pf-PF_INET6-proto-IPPROTO_SCTP-type-SOCK_STREAM)
 151                          */
 152                         if (++try_loading_module == 1)
 153                                 request_module("net-pf-%d-proto-%d-type-%d",
 154                                                 PF_INET6, protocol, sock->type);
 155                         /*
 156                          * Fall back to generic, e.g. net-pf-10-proto-132
 157                          * (net-pf-PF_INET6-proto-IPPROTO_SCTP)
 158                          */
 159                         else
 160                                 request_module("net-pf-%d-proto-%d",
 161                                                 PF_INET6, protocol);
 162                         goto lookup_protocol;
 163                 } else
 164                         goto out_rcu_unlock;
 165         }
 166
 167         err = -EPERM;
 168         if (sock->type == SOCK_RAW && !kern &&
 169             !ns_capable(net->user_ns, CAP_NET_RAW))
 170                 goto out_rcu_unlock;
 171
 172         sock->ops = answer->ops;
 173         answer_prot = answer->prot;
 174         answer_flags = answer->flags;
 175         rcu_read_unlock();
 176
 177         WARN_ON(!answer_prot->slab);
 178
 179         err = -ENOBUFS;
 180         sk = sk_alloc(net, PF_INET6, GFP_KERNEL, answer_prot, kern);
 181         if (!sk)
 182                 goto out;
 183
 184         sock_init_data(sock, sk);
 185
 186         err = 0;
 187         if (INET_PROTOSW_REUSE & answer_flags)
 188                 sk->sk_reuse = SK_CAN_REUSE;
 189
 190         inet = inet_sk(sk);
 191         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
 192
 193         if (SOCK_RAW == sock->type) {
 194                 inet->inet_num = protocol;
 195                 if (IPPROTO_RAW == protocol)
 196                         inet->hdrincl = 1;
 197         }
 198
 199         sk->sk_destruct         = inet_sock_destruct;
 200         sk->sk_family           = PF_INET6;
 201         sk->sk_protocol         = protocol;
 202
 203         sk->sk_backlog_rcv      = answer->prot->backlog_rcv;
 204
 205         inet_sk(sk)->pinet6 = np = inet6_sk_generic(sk);
 206         np->hop_limit   = -1;
 207         np->mcast_hops  = IPV6_DEFAULT_MCASTHOPS;
 208         np->mc_loop     = 1;
 209         np->mc_all      = 1;
 210         np->pmtudisc    = IPV6_PMTUDISC_WANT;
 211         np->repflow     = net->ipv6.sysctl.flowlabel_reflect;
 212         sk->sk_ipv6only = net->ipv6.sysctl.bindv6only;
 213
 214         /* Init the ipv4 part of the socket since we can have sockets
 215          * using v6 API for ipv4.
 216          */
 217         inet->uc_ttl    = -1;
 218
 219         inet->mc_loop   = 1;
 220         inet->mc_ttl    = 1;
 221         inet->mc_index  = 0;
 222         inet->mc_list   = NULL;
 223         inet->rcv_tos   = 0;
 224
 225         if (net->ipv4.sysctl_ip_no_pmtu_disc)
 226                 inet->pmtudisc = IP_PMTUDISC_DONT;
 227         else
 228                 inet->pmtudisc = IP_PMTUDISC_WANT;
 229         /*
 230          * Increment only the relevant sk_prot->socks debug field, this changes
 231          * the previous behaviour of incrementing both the equivalent to
 232          * answer->prot->socks (inet6_sock_nr) and inet_sock_nr.
 233          *
 234          * This allows better debug granularity as we'll know exactly how many
 235          * UDPv6, TCPv6, etc socks were allocated, not the sum of all IPv6
 236          * transport protocol socks. -acme
 237          */
 238         sk_refcnt_debug_inc(sk);
 239
 240         if (inet->inet_num) {
 241                 /* It assumes that any protocol which allows
 242                  * the user to assign a number at socket
 243                  * creation time automatically shares.
 244                  */
 245                 inet->inet_sport = htons(inet->inet_num);
 246                 err = sk->sk_prot->hash(sk);
 247                 if (err) {
 248                         sk_common_release(sk);
 249                         goto out;
 250                 }
 251         }
 252         if (sk->sk_prot->init) {
 253                 err = sk->sk_prot->init(sk);
 254                 if (err) {
 255                         sk_common_release(sk);
 256                         goto out;
 257                 }
 258         }
 259
 260         if (!kern) {
 261                 err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
 262                 if (err) {
 263                         sk_common_release(sk);
 264                         goto out;
 265                 }
 266         }
 267 out:
 268         return err;
 269 out_rcu_unlock:
 270         rcu_read_unlock();
 271         goto out;
 272 }
 273
 274 static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
 275                         bool force_bind_address_no_port, bool with_lock)
 276 {
 277         struct sockaddr_in6 *addr = (struct sockaddr_in6 *)uaddr;
 278         struct inet_sock *inet = inet_sk(sk);
 279         struct ipv6_pinfo *np = inet6_sk(sk);
 280         struct net *net = sock_net(sk);
 281         __be32 v4addr = 0;
 282         unsigned short snum;
 283         bool saved_ipv6only;
 284         int addr_type = 0;
 285         int err = 0;
 286
 287         if (addr->sin6_family != AF_INET6)
 288                 return -EAFNOSUPPORT;
 289
 290         addr_type = ipv6_addr_type(&addr->sin6_addr);
 291         if ((addr_type & IPV6_ADDR_MULTICAST) && sk->sk_type == SOCK_STREAM)
 292                 return -EINVAL;
 293
 294         snum = ntohs(addr->sin6_port);
 295         if (snum && snum < inet_prot_sock(net) &&
 296             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
 297                 return -EACCES;
 298
 299         if (with_lock)
 300                 lock_sock(sk);
 301
 302         /* Check these errors (active socket, double bind). */
 303         if (sk->sk_state != TCP_CLOSE || inet->inet_num) {
 304                 err = -EINVAL;
 305                 goto out;
 306         }
 307
 308         /* Check if the address belongs to the host. */
 309         if (addr_type == IPV6_ADDR_MAPPED) {
 310                 struct net_device *dev = NULL;
 311                 int chk_addr_ret;
 312
 313                 /* Binding to v4-mapped address on a v6-only socket
 314                  * makes no sense
 315                  */
 316                 if (sk->sk_ipv6only) {
 317                         err = -EINVAL;
 318                         goto out;
 319                 }
 320
 321                 rcu_read_lock();
 322                 if (sk->sk_bound_dev_if) {
 323                         dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
 324                         if (!dev) {
 325                                 err = -ENODEV;
 326                                 goto out_unlock;
 327                         }
 328                 }
 329
 330                 /* Reproduce AF_INET checks to make the bindings consistent */
 331                 v4addr = addr->sin6_addr.s6_addr32[3];
 332                 chk_addr_ret = inet_addr_type_dev_table(net, dev, v4addr);
 333                 rcu_read_unlock();
 334
 335                 if (!inet_can_nonlocal_bind(net, inet) &&
 336                     v4addr != htonl(INADDR_ANY) &&
 337                     chk_addr_ret != RTN_LOCAL &&
 338                     chk_addr_ret != RTN_MULTICAST &&
 339                     chk_addr_ret != RTN_BROADCAST) {
 340                         err = -EADDRNOTAVAIL;
 341                         goto out;
 342                 }
 343         } else {
 344                 if (addr_type != IPV6_ADDR_ANY) {
 345                         struct net_device *dev = NULL;
 346
 347                         rcu_read_lock();
 348                         if (__ipv6_addr_needs_scope_id(addr_type)) {
 349                                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 350                                     addr->sin6_scope_id) {
 351                                         /* Override any existing binding, if another one
 352                                          * is supplied by user.
 353                                          */
 354                                         sk->sk_bound_dev_if = addr->sin6_scope_id;
 355                                 }
 356
 357                                 /* Binding to link-local address requires an interface */
 358                                 if (!sk->sk_bound_dev_if) {
 359                                         err = -EINVAL;
 360                                         goto out_unlock;
 361                                 }
 362                         }
 363
 364                         if (sk->sk_bound_dev_if) {
 365                                 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
 366                                 if (!dev) {
 367                                         err = -ENODEV;
 368                                         goto out_unlock;
 369                                 }
 370                         }
 371
 372                         /* ipv4 addr of the socket is invalid.  Only the
 373                          * unspecified and mapped address have a v4 equivalent.
 374                          */
 375                         v4addr = LOOPBACK4_IPV6;
 376                         if (!(addr_type & IPV6_ADDR_MULTICAST)) {
 377                                 if (!ipv6_can_nonlocal_bind(net, inet) &&
 378                                     !ipv6_chk_addr(net, &addr->sin6_addr,
 379                                                    dev, 0)) {
 380                                         err = -EADDRNOTAVAIL;
 381                                         goto out_unlock;
 382                                 }
 383                         }
 384                         rcu_read_unlock();
 385                 }
 386         }
 387
 388         inet->inet_rcv_saddr = v4addr;
 389         inet->inet_saddr = v4addr;
 390
 391         sk->sk_v6_rcv_saddr = addr->sin6_addr;
 392
 393         if (!(addr_type & IPV6_ADDR_MULTICAST))
 394                 np->saddr = addr->sin6_addr;
 395
 396         saved_ipv6only = sk->sk_ipv6only;
 397         if (addr_type != IPV6_ADDR_ANY && addr_type != IPV6_ADDR_MAPPED)
 398                 sk->sk_ipv6only = 1;
 399
 400         /* Make sure we are allowed to bind here. */
 401         if (snum || !(inet->bind_address_no_port ||
 402                       force_bind_address_no_port)) {
 403                 if (sk->sk_prot->get_port(sk, snum)) {
 404                         sk->sk_ipv6only = saved_ipv6only;
 405                         inet_reset_saddr(sk);
 406                         err = -EADDRINUSE;
 407                         goto out;
 408                 }
 409                 err = BPF_CGROUP_RUN_PROG_INET6_POST_BIND(sk);
 410                 if (err) {
 411                         sk->sk_ipv6only = saved_ipv6only;
 412                         inet_reset_saddr(sk);
 413                         goto out;
 414                 }
 415         }
 416
 417         if (addr_type != IPV6_ADDR_ANY)
 418                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 419         if (snum)
 420                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 421         inet->inet_sport = htons(inet->inet_num);
 422         inet->inet_dport = 0;
 423         inet->inet_daddr = 0;
 424 out:
 425         if (with_lock)
 426                 release_sock(sk);
 427         return err;
 428 out_unlock:
 429         rcu_read_unlock();
 430         goto out;
 431 }
 432
 433 /* bind for INET6 API */
 434 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 435 {
 436         struct sock *sk = sock->sk;
 437         int err = 0;
 438
 439         /* If the socket has its own bind function then use it. */
 440         if (sk->sk_prot->bind)
 441                 return sk->sk_prot->bind(sk, uaddr, addr_len);
 442
 443         if (addr_len < SIN6_LEN_RFC2133)
 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_INET6_BIND(sk, uaddr);
 450         if (err)
 451                 return err;
 452
 453         return __inet6_bind(sk, uaddr, addr_len, false, true);
 454 }
 455 EXPORT_SYMBOL(inet6_bind);
 456
 457 int inet6_release(struct socket *sock)
 458 {
 459         struct sock *sk = sock->sk;
 460
 461         if (!sk)
 462                 return -EINVAL;
 463
 464         /* Free mc lists */
 465         ipv6_sock_mc_close(sk);
 466
 467         /* Free ac lists */
 468         ipv6_sock_ac_close(sk);
 469
 470         return inet_release(sock);
 471 }
 472 EXPORT_SYMBOL(inet6_release);
 473
 474 void inet6_destroy_sock(struct sock *sk)
 475 {
 476         struct ipv6_pinfo *np = inet6_sk(sk);
 477         struct sk_buff *skb;
 478         struct ipv6_txoptions *opt;
 479
 480         /* Release rx options */
 481
 482         skb = xchg(&np->pktoptions, NULL);
 483         kfree_skb(skb);
 484
 485         skb = xchg(&np->rxpmtu, NULL);
 486         kfree_skb(skb);
 487
 488         /* Free flowlabels */
 489         fl6_free_socklist(sk);
 490
 491         /* Free tx options */
 492
 493         opt = xchg((__force struct ipv6_txoptions **)&np->opt, NULL);
 494         if (opt) {
 495                 atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
 496                 txopt_put(opt);
 497         }
 498 }
 499 EXPORT_SYMBOL_GPL(inet6_destroy_sock);
 500
 501 /*
 502  *      This does both peername and sockname.
 503  */
 504
 505 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
 506                  int peer)
 507 {
 508         struct sockaddr_in6 *sin = (struct sockaddr_in6 *)uaddr;
 509         struct sock *sk = sock->sk;
 510         struct inet_sock *inet = inet_sk(sk);
 511         struct ipv6_pinfo *np = inet6_sk(sk);
 512
 513         sin->sin6_family = AF_INET6;
 514         sin->sin6_flowinfo = 0;
 515         sin->sin6_scope_id = 0;
 516         if (peer) {
 517                 if (!inet->inet_dport)
 518                         return -ENOTCONN;
 519                 if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
 520                     peer == 1)
 521                         return -ENOTCONN;
 522                 sin->sin6_port = inet->inet_dport;
 523                 sin->sin6_addr = sk->sk_v6_daddr;
 524                 if (np->sndflow)
 525                         sin->sin6_flowinfo = np->flow_label;
 526         } else {
 527                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 528                         sin->sin6_addr = np->saddr;
 529                 else
 530                         sin->sin6_addr = sk->sk_v6_rcv_saddr;
 531
 532                 sin->sin6_port = inet->inet_sport;
 533         }
 534         sin->sin6_scope_id = ipv6_iface_scope_id(&sin->sin6_addr,
 535                                                  sk->sk_bound_dev_if);
 536         return sizeof(*sin);
 537 }
 538 EXPORT_SYMBOL(inet6_getname);
 539
 540 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 541 {
 542         struct sock *sk = sock->sk;
 543         struct net *net = sock_net(sk);
 544
 545         switch (cmd) {
 546         case SIOCADDRT:
 547         case SIOCDELRT:
 548
 549                 return ipv6_route_ioctl(net, cmd, (void __user *)arg);
 550
 551         case SIOCSIFADDR:
 552                 return addrconf_add_ifaddr(net, (void __user *) arg);
 553         case SIOCDIFADDR:
 554                 return addrconf_del_ifaddr(net, (void __user *) arg);
 555         case SIOCSIFDSTADDR:
 556                 return addrconf_set_dstaddr(net, (void __user *) arg);
 557         default:
 558                 if (!sk->sk_prot->ioctl)
 559                         return -ENOIOCTLCMD;
 560                 return sk->sk_prot->ioctl(sk, cmd, arg);
 561         }
 562         /*NOTREACHED*/
 563         return 0;
 564 }
 565 EXPORT_SYMBOL(inet6_ioctl);
 566
 567 const struct proto_ops inet6_stream_ops = {
 568         .family            = PF_INET6,
 569         .owner             = THIS_MODULE,
 570         .release           = inet6_release,
 571         .bind              = inet6_bind,
 572         .connect           = inet_stream_connect,       /* ok           */
 573         .socketpair        = sock_no_socketpair,        /* a do nothing */
 574         .accept            = inet_accept,               /* ok           */
 575         .getname           = inet6_getname,
 576         .poll              = tcp_poll,                  /* ok           */
 577         .ioctl             = inet6_ioctl,               /* must change  */
 578         .gettstamp         = sock_gettstamp,
 579         .listen            = inet_listen,               /* ok           */
 580         .shutdown          = inet_shutdown,             /* ok           */
 581         .setsockopt        = sock_common_setsockopt,    /* ok           */
 582         .getsockopt        = sock_common_getsockopt,    /* ok           */
 583         .sendmsg           = inet_sendmsg,              /* ok           */
 584         .recvmsg           = inet_recvmsg,              /* ok           */
 585 #ifdef CONFIG_MMU
 586         .mmap              = tcp_mmap,
 587 #endif
 588         .sendpage          = inet_sendpage,
 589         .sendmsg_locked    = tcp_sendmsg_locked,
 590         .sendpage_locked   = tcp_sendpage_locked,
 591         .splice_read       = tcp_splice_read,
 592         .read_sock         = tcp_read_sock,
 593         .peek_len          = tcp_peek_len,
 594 #ifdef CONFIG_COMPAT
 595         .compat_setsockopt = compat_sock_common_setsockopt,
 596         .compat_getsockopt = compat_sock_common_getsockopt,
 597 #endif
 598         .set_rcvlowat      = tcp_set_rcvlowat,
 599 };
 600
 601 const struct proto_ops inet6_dgram_ops = {
 602         .family            = PF_INET6,
 603         .owner             = THIS_MODULE,
 604         .release           = inet6_release,
 605         .bind              = inet6_bind,
 606         .connect           = inet_dgram_connect,        /* ok           */
 607         .socketpair        = sock_no_socketpair,        /* a do nothing */
 608         .accept            = sock_no_accept,            /* a do nothing */
 609         .getname           = inet6_getname,
 610         .poll              = udp_poll,                  /* ok           */
 611         .ioctl             = inet6_ioctl,               /* must change  */
 612         .gettstamp         = sock_gettstamp,
 613         .listen            = sock_no_listen,            /* ok           */
 614         .shutdown          = inet_shutdown,             /* ok           */
 615         .setsockopt        = sock_common_setsockopt,    /* ok           */
 616         .getsockopt        = sock_common_getsockopt,    /* ok           */
 617         .sendmsg           = inet_sendmsg,              /* ok           */
 618         .recvmsg           = inet_recvmsg,              /* ok           */
 619         .mmap              = sock_no_mmap,
 620         .sendpage          = sock_no_sendpage,
 621         .set_peek_off      = sk_set_peek_off,
 622 #ifdef CONFIG_COMPAT
 623         .compat_setsockopt = compat_sock_common_setsockopt,
 624         .compat_getsockopt = compat_sock_common_getsockopt,
 625 #endif
 626 };
 627
 628 static const struct net_proto_family inet6_family_ops = {
 629         .family = PF_INET6,
 630         .create = inet6_create,
 631         .owner  = THIS_MODULE,
 632 };
 633
 634 int inet6_register_protosw(struct inet_protosw *p)
 635 {
 636         struct list_head *lh;
 637         struct inet_protosw *answer;
 638         struct list_head *last_perm;
 639         int protocol = p->protocol;
 640         int ret;
 641
 642         spin_lock_bh(&inetsw6_lock);
 643
 644         ret = -EINVAL;
 645         if (p->type >= SOCK_MAX)
 646                 goto out_illegal;
 647
 648         /* If we are trying to override a permanent protocol, bail. */
 649         answer = NULL;
 650         ret = -EPERM;
 651         last_perm = &inetsw6[p->type];
 652         list_for_each(lh, &inetsw6[p->type]) {
 653                 answer = list_entry(lh, struct inet_protosw, list);
 654
 655                 /* Check only the non-wild match. */
 656                 if (INET_PROTOSW_PERMANENT & answer->flags) {
 657                         if (protocol == answer->protocol)
 658                                 break;
 659                         last_perm = lh;
 660                 }
 661
 662                 answer = NULL;
 663         }
 664         if (answer)
 665                 goto out_permanent;
 666
 667         /* Add the new entry after the last permanent entry if any, so that
 668          * the new entry does not override a permanent entry when matched with
 669          * a wild-card protocol. But it is allowed to override any existing
 670          * non-permanent entry.  This means that when we remove this entry, the
 671          * system automatically returns to the old behavior.
 672          */
 673         list_add_rcu(&p->list, last_perm);
 674         ret = 0;
 675 out:
 676         spin_unlock_bh(&inetsw6_lock);
 677         return ret;
 678
 679 out_permanent:
 680         pr_err("Attempt to override permanent protocol %d\n", protocol);
 681         goto out;
 682
 683 out_illegal:
 684         pr_err("Ignoring attempt to register invalid socket type %d\n",
 685                p->type);
 686         goto out;
 687 }
 688 EXPORT_SYMBOL(inet6_register_protosw);
 689
 690 void
 691 inet6_unregister_protosw(struct inet_protosw *p)
 692 {
 693         if (INET_PROTOSW_PERMANENT & p->flags) {
 694                 pr_err("Attempt to unregister permanent protocol %d\n",
 695                        p->protocol);
 696         } else {
 697                 spin_lock_bh(&inetsw6_lock);
 698                 list_del_rcu(&p->list);
 699                 spin_unlock_bh(&inetsw6_lock);
 700
 701                 synchronize_net();
 702         }
 703 }
 704 EXPORT_SYMBOL(inet6_unregister_protosw);
 705
 706 int inet6_sk_rebuild_header(struct sock *sk)
 707 {
 708         struct ipv6_pinfo *np = inet6_sk(sk);
 709         struct dst_entry *dst;
 710
 711         dst = __sk_dst_check(sk, np->dst_cookie);
 712
 713         if (!dst) {
 714                 struct inet_sock *inet = inet_sk(sk);
 715                 struct in6_addr *final_p, final;
 716                 struct flowi6 fl6;
 717
 718                 memset(&fl6, 0, sizeof(fl6));
 719                 fl6.flowi6_proto = sk->sk_protocol;
 720                 fl6.daddr = sk->sk_v6_daddr;
 721                 fl6.saddr = np->saddr;
 722                 fl6.flowlabel = np->flow_label;
 723                 fl6.flowi6_oif = sk->sk_bound_dev_if;
 724                 fl6.flowi6_mark = sk->sk_mark;
 725                 fl6.fl6_dport = inet->inet_dport;
 726                 fl6.fl6_sport = inet->inet_sport;
 727                 fl6.flowi6_uid = sk->sk_uid;
 728                 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 729
 730                 rcu_read_lock();
 731                 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt),
 732                                          &final);
 733                 rcu_read_unlock();
 734
 735                 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 736                 if (IS_ERR(dst)) {
 737                         sk->sk_route_caps = 0;
 738                         sk->sk_err_soft = -PTR_ERR(dst);
 739                         return PTR_ERR(dst);
 740                 }
 741
 742                 ip6_dst_store(sk, dst, NULL, NULL);
 743         }
 744
 745         return 0;
 746 }
 747 EXPORT_SYMBOL_GPL(inet6_sk_rebuild_header);
 748
 749 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
 750                        const struct inet6_skb_parm *opt)
 751 {
 752         const struct ipv6_pinfo *np = inet6_sk(sk);
 753
 754         if (np->rxopt.all) {
 755                 if (((opt->flags & IP6SKB_HOPBYHOP) &&
 756                      (np->rxopt.bits.hopopts || np->rxopt.bits.ohopopts)) ||
 757                     (ip6_flowinfo((struct ipv6hdr *) skb_network_header(skb)) &&
 758                      np->rxopt.bits.rxflow) ||
 759                     (opt->srcrt && (np->rxopt.bits.srcrt ||
 760                      np->rxopt.bits.osrcrt)) ||
 761                     ((opt->dst1 || opt->dst0) &&
 762                      (np->rxopt.bits.dstopts || np->rxopt.bits.odstopts)))
 763                         return true;
 764         }
 765         return false;
 766 }
 767 EXPORT_SYMBOL_GPL(ipv6_opt_accepted);
 768
 769 static struct packet_type ipv6_packet_type __read_mostly = {
 770         .type = cpu_to_be16(ETH_P_IPV6),
 771         .func = ipv6_rcv,
 772         .list_func = ipv6_list_rcv,
 773 };
 774
 775 static int __init ipv6_packet_init(void)
 776 {
 777         dev_add_pack(&ipv6_packet_type);
 778         return 0;
 779 }
 780
 781 static void ipv6_packet_cleanup(void)
 782 {
 783         dev_remove_pack(&ipv6_packet_type);
 784 }
 785
 786 static int __net_init ipv6_init_mibs(struct net *net)
 787 {
 788         int i;
 789
 790         net->mib.udp_stats_in6 = alloc_percpu(struct udp_mib);
 791         if (!net->mib.udp_stats_in6)
 792                 return -ENOMEM;
 793         net->mib.udplite_stats_in6 = alloc_percpu(struct udp_mib);
 794         if (!net->mib.udplite_stats_in6)
 795                 goto err_udplite_mib;
 796         net->mib.ipv6_statistics = alloc_percpu(struct ipstats_mib);
 797         if (!net->mib.ipv6_statistics)
 798                 goto err_ip_mib;
 799
 800         for_each_possible_cpu(i) {
 801                 struct ipstats_mib *af_inet6_stats;
 802                 af_inet6_stats = per_cpu_ptr(net->mib.ipv6_statistics, i);
 803                 u64_stats_init(&af_inet6_stats->syncp);
 804         }
 805
 806
 807         net->mib.icmpv6_statistics = alloc_percpu(struct icmpv6_mib);
 808         if (!net->mib.icmpv6_statistics)
 809                 goto err_icmp_mib;
 810         net->mib.icmpv6msg_statistics = kzalloc(sizeof(struct icmpv6msg_mib),
 811                                                 GFP_KERNEL);
 812         if (!net->mib.icmpv6msg_statistics)
 813                 goto err_icmpmsg_mib;
 814         return 0;
 815
 816 err_icmpmsg_mib:
 817         free_percpu(net->mib.icmpv6_statistics);
 818 err_icmp_mib:
 819         free_percpu(net->mib.ipv6_statistics);
 820 err_ip_mib:
 821         free_percpu(net->mib.udplite_stats_in6);
 822 err_udplite_mib:
 823         free_percpu(net->mib.udp_stats_in6);
 824         return -ENOMEM;
 825 }
 826
 827 static void ipv6_cleanup_mibs(struct net *net)
 828 {
 829         free_percpu(net->mib.udp_stats_in6);
 830         free_percpu(net->mib.udplite_stats_in6);
 831         free_percpu(net->mib.ipv6_statistics);
 832         free_percpu(net->mib.icmpv6_statistics);
 833         kfree(net->mib.icmpv6msg_statistics);
 834 }
 835
 836 static int __net_init inet6_net_init(struct net *net)
 837 {
 838         int err = 0;
 839
 840         net->ipv6.sysctl.bindv6only = 0;
 841         net->ipv6.sysctl.icmpv6_time = 1*HZ;
 842         net->ipv6.sysctl.icmpv6_echo_ignore_all = 0;
 843         net->ipv6.sysctl.icmpv6_echo_ignore_multicast = 0;
 844         net->ipv6.sysctl.icmpv6_echo_ignore_anycast = 0;
 845
 846         /* By default, rate limit error messages.
 847          * Except for pmtu discovery, it would break it.
 848          * proc_do_large_bitmap needs pointer to the bitmap.
 849          */
 850         bitmap_set(net->ipv6.sysctl.icmpv6_ratemask, 0, ICMPV6_ERRMSG_MAX + 1);
 851         bitmap_clear(net->ipv6.sysctl.icmpv6_ratemask, ICMPV6_PKT_TOOBIG, 1);
 852         net->ipv6.sysctl.icmpv6_ratemask_ptr = net->ipv6.sysctl.icmpv6_ratemask;
 853
 854         net->ipv6.sysctl.flowlabel_consistency = 1;
 855         net->ipv6.sysctl.auto_flowlabels = IP6_DEFAULT_AUTO_FLOW_LABELS;
 856         net->ipv6.sysctl.idgen_retries = 3;
 857         net->ipv6.sysctl.idgen_delay = 1 * HZ;
 858         net->ipv6.sysctl.flowlabel_state_ranges = 0;
 859         net->ipv6.sysctl.max_dst_opts_cnt = IP6_DEFAULT_MAX_DST_OPTS_CNT;
 860         net->ipv6.sysctl.max_hbh_opts_cnt = IP6_DEFAULT_MAX_HBH_OPTS_CNT;
 861         net->ipv6.sysctl.max_dst_opts_len = IP6_DEFAULT_MAX_DST_OPTS_LEN;
 862         net->ipv6.sysctl.max_hbh_opts_len = IP6_DEFAULT_MAX_HBH_OPTS_LEN;
 863         atomic_set(&net->ipv6.fib6_sernum, 1);
 864
 865         err = ipv6_init_mibs(net);
 866         if (err)
 867                 return err;
 868 #ifdef CONFIG_PROC_FS
 869         err = udp6_proc_init(net);
 870         if (err)
 871                 goto out;
 872         err = tcp6_proc_init(net);
 873         if (err)
 874                 goto proc_tcp6_fail;
 875         err = ac6_proc_init(net);
 876         if (err)
 877                 goto proc_ac6_fail;
 878 #endif
 879         return err;
 880
 881 #ifdef CONFIG_PROC_FS
 882 proc_ac6_fail:
 883         tcp6_proc_exit(net);
 884 proc_tcp6_fail:
 885         udp6_proc_exit(net);
 886 out:
 887         ipv6_cleanup_mibs(net);
 888         return err;
 889 #endif
 890 }
 891
 892 static void __net_exit inet6_net_exit(struct net *net)
 893 {
 894 #ifdef CONFIG_PROC_FS
 895         udp6_proc_exit(net);
 896         tcp6_proc_exit(net);
 897         ac6_proc_exit(net);
 898 #endif
 899         ipv6_cleanup_mibs(net);
 900 }
 901
 902 static struct pernet_operations inet6_net_ops = {
 903         .init = inet6_net_init,
 904         .exit = inet6_net_exit,
 905 };
 906
 907 static int ipv6_route_input(struct sk_buff *skb)
 908 {
 909         ip6_route_input(skb);
 910         return skb_dst(skb)->error;
 911 }
 912
 913 static const struct ipv6_stub ipv6_stub_impl = {
 914         .ipv6_sock_mc_join = ipv6_sock_mc_join,
 915         .ipv6_sock_mc_drop = ipv6_sock_mc_drop,
 916         .ipv6_dst_lookup   = ip6_dst_lookup,
 917         .ipv6_route_input  = ipv6_route_input,
 918         .fib6_get_table    = fib6_get_table,
 919         .fib6_table_lookup = fib6_table_lookup,
 920         .fib6_lookup       = fib6_lookup,
 921         .fib6_select_path  = fib6_select_path,
 922         .ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
 923         .fib6_nh_init      = fib6_nh_init,
 924         .fib6_nh_release   = fib6_nh_release,
 925         .udpv6_encap_enable = udpv6_encap_enable,
 926         .ndisc_send_na = ndisc_send_na,
 927         .nd_tbl = &nd_tbl,
 928 };
 929
 930 static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {
 931         .inet6_bind = __inet6_bind,
 932         .udp6_lib_lookup = __udp6_lib_lookup,
 933 };
 934
 935 static int __init inet6_init(void)
 936 {
 937         struct list_head *r;
 938         int err = 0;
 939
 940         sock_skb_cb_check_size(sizeof(struct inet6_skb_parm));
 941
 942         /* Register the socket-side information for inet6_create.  */
 943         for (r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
 944                 INIT_LIST_HEAD(r);
 945
 946         if (disable_ipv6_mod) {
 947                 pr_info("Loaded, but administratively disabled, reboot required to enable\n");
 948                 goto out;
 949         }
 950
 951         err = proto_register(&tcpv6_prot, 1);
 952         if (err)
 953                 goto out;
 954
 955         err = proto_register(&udpv6_prot, 1);
 956         if (err)
 957                 goto out_unregister_tcp_proto;
 958
 959         err = proto_register(&udplitev6_prot, 1);
 960         if (err)
 961                 goto out_unregister_udp_proto;
 962
 963         err = proto_register(&rawv6_prot, 1);
 964         if (err)
 965                 goto out_unregister_udplite_proto;
 966
 967         err = proto_register(&pingv6_prot, 1);
 968         if (err)
 969                 goto out_unregister_raw_proto;
 970
 971         /* We MUST register RAW sockets before we create the ICMP6,
 972          * IGMP6, or NDISC control sockets.
 973          */
 974         err = rawv6_init();
 975         if (err)
 976                 goto out_unregister_ping_proto;
 977
 978         /* Register the family here so that the init calls below will
 979          * be able to create sockets. (?? is this dangerous ??)
 980          */
 981         err = sock_register(&inet6_family_ops);
 982         if (err)
 983                 goto out_sock_register_fail;
 984
 985         /*
 986          *      ipngwg API draft makes clear that the correct semantics
 987          *      for TCP and UDP is to consider one TCP and UDP instance
 988          *      in a host available by both INET and INET6 APIs and
 989          *      able to communicate via both network protocols.
 990          */
 991
 992         err = register_pernet_subsys(&inet6_net_ops);
 993         if (err)
 994                 goto register_pernet_fail;
 995         err = ip6_mr_init();
 996         if (err)
 997                 goto ipmr_fail;
 998         err = icmpv6_init();
 999         if (err)
1000                 goto icmp_fail;
1001         err = ndisc_init();
1002         if (err)
1003                 goto ndisc_fail;
1004         err = igmp6_init();
1005         if (err)
1006                 goto igmp_fail;
1007
1008         err = ipv6_netfilter_init();
1009         if (err)
1010                 goto netfilter_fail;
1011         /* Create /proc/foo6 entries. */
1012 #ifdef CONFIG_PROC_FS
1013         err = -ENOMEM;
1014         if (raw6_proc_init())
1015                 goto proc_raw6_fail;
1016         if (udplite6_proc_init())
1017                 goto proc_udplite6_fail;
1018         if (ipv6_misc_proc_init())
1019                 goto proc_misc6_fail;
1020         if (if6_proc_init())
1021                 goto proc_if6_fail;
1022 #endif
1023         err = ip6_route_init();
1024         if (err)
1025                 goto ip6_route_fail;
1026         err = ndisc_late_init();
1027         if (err)
1028                 goto ndisc_late_fail;
1029         err = ip6_flowlabel_init();
1030         if (err)
1031                 goto ip6_flowlabel_fail;
1032         err = ipv6_anycast_init();
1033         if (err)
1034                 goto ipv6_anycast_fail;
1035         err = addrconf_init();
1036         if (err)
1037                 goto addrconf_fail;
1038
1039         /* Init v6 extension headers. */
1040         err = ipv6_exthdrs_init();
1041         if (err)
1042                 goto ipv6_exthdrs_fail;
1043
1044         err = ipv6_frag_init();
1045         if (err)
1046                 goto ipv6_frag_fail;
1047
1048         /* Init v6 transport protocols. */
1049         err = udpv6_init();
1050         if (err)
1051                 goto udpv6_fail;
1052
1053         err = udplitev6_init();
1054         if (err)
1055                 goto udplitev6_fail;
1056
1057         err = udpv6_offload_init();
1058         if (err)
1059                 goto udpv6_offload_fail;
1060
1061         err = tcpv6_init();
1062         if (err)
1063                 goto tcpv6_fail;
1064
1065         err = ipv6_packet_init();
1066         if (err)
1067                 goto ipv6_packet_fail;
1068
1069         err = pingv6_init();
1070         if (err)
1071                 goto pingv6_fail;
1072
1073         err = calipso_init();
1074         if (err)
1075                 goto calipso_fail;
1076
1077         err = seg6_init();
1078         if (err)
1079                 goto seg6_fail;
1080
1081         err = igmp6_late_init();
1082         if (err)
1083                 goto igmp6_late_err;
1084
1085 #ifdef CONFIG_SYSCTL
1086         err = ipv6_sysctl_register();
1087         if (err)
1088                 goto sysctl_fail;
1089 #endif
1090
1091         /* ensure that ipv6 stubs are visible only after ipv6 is ready */
1092         wmb();
1093         ipv6_stub = &ipv6_stub_impl;
1094         ipv6_bpf_stub = &ipv6_bpf_stub_impl;
1095 out:
1096         return err;
1097
1098 #ifdef CONFIG_SYSCTL
1099 sysctl_fail:
1100         igmp6_late_cleanup();
1101 #endif
1102 igmp6_late_err:
1103         seg6_exit();
1104 seg6_fail:
1105         calipso_exit();
1106 calipso_fail:
1107         pingv6_exit();
1108 pingv6_fail:
1109         ipv6_packet_cleanup();
1110 ipv6_packet_fail:
1111         tcpv6_exit();
1112 tcpv6_fail:
1113         udpv6_offload_exit();
1114 udpv6_offload_fail:
1115         udplitev6_exit();
1116 udplitev6_fail:
1117         udpv6_exit();
1118 udpv6_fail:
1119         ipv6_frag_exit();
1120 ipv6_frag_fail:
1121         ipv6_exthdrs_exit();
1122 ipv6_exthdrs_fail:
1123         addrconf_cleanup();
1124 addrconf_fail:
1125         ipv6_anycast_cleanup();
1126 ipv6_anycast_fail:
1127         ip6_flowlabel_cleanup();
1128 ip6_flowlabel_fail:
1129         ndisc_late_cleanup();
1130 ndisc_late_fail:
1131         ip6_route_cleanup();
1132 ip6_route_fail:
1133 #ifdef CONFIG_PROC_FS
1134         if6_proc_exit();
1135 proc_if6_fail:
1136         ipv6_misc_proc_exit();
1137 proc_misc6_fail:
1138         udplite6_proc_exit();
1139 proc_udplite6_fail:
1140         raw6_proc_exit();
1141 proc_raw6_fail:
1142 #endif
1143         ipv6_netfilter_fini();
1144 netfilter_fail:
1145         igmp6_cleanup();
1146 igmp_fail:
1147         ndisc_cleanup();
1148 ndisc_fail:
1149         icmpv6_cleanup();
1150 icmp_fail:
1151         ip6_mr_cleanup();
1152 ipmr_fail:
1153         unregister_pernet_subsys(&inet6_net_ops);
1154 register_pernet_fail:
1155         sock_unregister(PF_INET6);
1156         rtnl_unregister_all(PF_INET6);
1157 out_sock_register_fail:
1158         rawv6_exit();
1159 out_unregister_ping_proto:
1160         proto_unregister(&pingv6_prot);
1161 out_unregister_raw_proto:
1162         proto_unregister(&rawv6_prot);
1163 out_unregister_udplite_proto:
1164         proto_unregister(&udplitev6_prot);
1165 out_unregister_udp_proto:
1166         proto_unregister(&udpv6_prot);
1167 out_unregister_tcp_proto:
1168         proto_unregister(&tcpv6_prot);
1169         goto out;
1170 }
1171 module_init(inet6_init);
1172
1173 MODULE_ALIAS_NETPROTO(PF_INET6);