net/sctp/ipv6.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* SCTP kernel implementation
   3  * (C) Copyright IBM Corp. 2002, 2004
   4  * Copyright (c) 2001 Nokia, Inc.
   5  * Copyright (c) 2001 La Monte H.P. Yarroll
   6  * Copyright (c) 2002-2003 Intel Corp.
   7  *
   8  * This file is part of the SCTP kernel implementation
   9  *
  10  * SCTP over IPv6.
  11  *
  12  * Please send any bug reports or fixes you make to the
  13  * email address(es):
  14  *    lksctp developers <[email protected]>
  15  *
  16  * Written or modified by:
  17  *    Le Yanqun             <[email protected]>
  18  *    Hui Huang             <[email protected]>
  19  *    La Monte H.P. Yarroll <[email protected]>
  20  *    Sridhar Samudrala     <[email protected]>
  21  *    Jon Grimm             <[email protected]>
  22  *    Ardelle Fan           <[email protected]>
  23  *
  24  * Based on:
  25  *      linux/net/ipv6/tcp_ipv6.c
  26  */
  27
  28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  29
  30 #include <linux/module.h>
  31 #include <linux/errno.h>
  32 #include <linux/types.h>
  33 #include <linux/socket.h>
  34 #include <linux/sockios.h>
  35 #include <linux/net.h>
  36 #include <linux/in.h>
  37 #include <linux/in6.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/init.h>
  40 #include <linux/ipsec.h>
  41 #include <linux/slab.h>
  42
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46 #include <linux/seq_file.h>
  47
  48 #include <net/protocol.h>
  49 #include <net/ndisc.h>
  50 #include <net/ip.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/inet_common.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/sctp/sctp.h>
  58 #include <net/udp_tunnel.h>
  59
  60 #include <linux/uaccess.h>
  61
  62 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  63                                          union sctp_addr *s2);
  64 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  65                               __be16 port);
  66 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  67                             const union sctp_addr *addr2);
  68
  69 /* Event handler for inet6 address addition/deletion events.
  70  * The sctp_local_addr_list needs to be protocted by a spin lock since
  71  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  72  * time and thus corrupt the list.
  73  * The reader side is protected with RCU.
  74  */
  75 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  76                                 void *ptr)
  77 {
  78         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  79         struct sctp_sockaddr_entry *addr = NULL;
  80         struct sctp_sockaddr_entry *temp;
  81         struct net *net = dev_net(ifa->idev->dev);
  82         int found = 0;
  83
  84         switch (ev) {
  85         case NETDEV_UP:
  86                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
  87                 if (addr) {
  88                         addr->a.v6.sin6_family = AF_INET6;
  89                         addr->a.v6.sin6_addr = ifa->addr;
  90                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
  91                         addr->valid = 1;
  92                         spin_lock_bh(&net->sctp.local_addr_lock);
  93                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
  94                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
  95                         spin_unlock_bh(&net->sctp.local_addr_lock);
  96                 }
  97                 break;
  98         case NETDEV_DOWN:
  99                 spin_lock_bh(&net->sctp.local_addr_lock);
 100                 list_for_each_entry_safe(addr, temp,
 101                                         &net->sctp.local_addr_list, list) {
 102                         if (addr->a.sa.sa_family == AF_INET6 &&
 103                             ipv6_addr_equal(&addr->a.v6.sin6_addr,
 104                                             &ifa->addr) &&
 105                             addr->a.v6.sin6_scope_id == ifa->idev->dev->ifindex) {
 106                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 107                                 found = 1;
 108                                 addr->valid = 0;
 109                                 list_del_rcu(&addr->list);
 110                                 break;
 111                         }
 112                 }
 113                 spin_unlock_bh(&net->sctp.local_addr_lock);
 114                 if (found)
 115                         kfree_rcu(addr, rcu);
 116                 break;
 117         }
 118
 119         return NOTIFY_DONE;
 120 }
 121
 122 static struct notifier_block sctp_inet6addr_notifier = {
 123         .notifier_call = sctp_inet6addr_event,
 124 };
 125
 126 static void sctp_v6_err_handle(struct sctp_transport *t, struct sk_buff *skb,
 127                                __u8 type, __u8 code, __u32 info)
 128 {
 129         struct sctp_association *asoc = t->asoc;
 130         struct sock *sk = asoc->base.sk;
 131         int err = 0;
 132
 133         switch (type) {
 134         case ICMPV6_PKT_TOOBIG:
 135                 if (ip6_sk_accept_pmtu(sk))
 136                         sctp_icmp_frag_needed(sk, asoc, t, info);
 137                 return;
 138         case ICMPV6_PARAMPROB:
 139                 if (ICMPV6_UNK_NEXTHDR == code) {
 140                         sctp_icmp_proto_unreachable(sk, asoc, t);
 141                         return;
 142                 }
 143                 break;
 144         case NDISC_REDIRECT:
 145                 sctp_icmp_redirect(sk, t, skb);
 146                 return;
 147         default:
 148                 break;
 149         }
 150
 151         icmpv6_err_convert(type, code, &err);
 152         if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
 153                 sk->sk_err = err;
 154                 sk_error_report(sk);
 155         } else {
 156                 WRITE_ONCE(sk->sk_err_soft, err);
 157         }
 158 }
 159
 160 /* ICMP error handler. */
 161 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 162                        u8 type, u8 code, int offset, __be32 info)
 163 {
 164         struct net *net = dev_net(skb->dev);
 165         struct sctp_transport *transport;
 166         struct sctp_association *asoc;
 167         __u16 saveip, savesctp;
 168         struct sock *sk;
 169
 170         /* Fix up skb to look at the embedded net header. */
 171         saveip   = skb->network_header;
 172         savesctp = skb->transport_header;
 173         skb_reset_network_header(skb);
 174         skb_set_transport_header(skb, offset);
 175         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 176         /* Put back, the original pointers. */
 177         skb->network_header   = saveip;
 178         skb->transport_header = savesctp;
 179         if (!sk) {
 180                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 181                 return -ENOENT;
 182         }
 183
 184         sctp_v6_err_handle(transport, skb, type, code, ntohl(info));
 185         sctp_err_finish(sk, transport);
 186
 187         return 0;
 188 }
 189
 190 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb)
 191 {
 192         struct net *net = dev_net(skb->dev);
 193         struct sctp_association *asoc;
 194         struct sctp_transport *t;
 195         struct icmp6hdr *hdr;
 196         __u32 info = 0;
 197
 198         skb->transport_header += sizeof(struct udphdr);
 199         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t);
 200         if (!sk) {
 201                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 202                 return -ENOENT;
 203         }
 204
 205         skb->transport_header -= sizeof(struct udphdr);
 206         hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr));
 207         if (hdr->icmp6_type == NDISC_REDIRECT) {
 208                 /* can't be handled without outer ip6hdr known, leave it to udpv6_err */
 209                 sctp_err_finish(sk, t);
 210                 return 0;
 211         }
 212         if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG)
 213                 info = ntohl(hdr->icmp6_mtu);
 214         sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info);
 215
 216         sctp_err_finish(sk, t);
 217         return 1;
 218 }
 219
 220 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t)
 221 {
 222         struct dst_entry *dst = dst_clone(t->dst);
 223         struct flowi6 *fl6 = &t->fl.u.ip6;
 224         struct sock *sk = skb->sk;
 225         struct ipv6_pinfo *np = inet6_sk(sk);
 226         __u8 tclass = np->tclass;
 227         __be32 label;
 228
 229         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 230                  skb->len, &fl6->saddr, &fl6->daddr);
 231
 232         if (t->dscp & SCTP_DSCP_SET_MASK)
 233                 tclass = t->dscp & SCTP_DSCP_VAL_MASK;
 234
 235         if (INET_ECN_is_capable(tclass))
 236                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 237
 238         if (!(t->param_flags & SPP_PMTUD_ENABLE))
 239                 skb->ignore_df = 1;
 240
 241         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 242
 243         if (!t->encap_port || !sctp_sk(sk)->udp_port) {
 244                 int res;
 245
 246                 skb_dst_set(skb, dst);
 247                 rcu_read_lock();
 248                 res = ip6_xmit(sk, skb, fl6, sk->sk_mark,
 249                                rcu_dereference(np->opt),
 250                                tclass, READ_ONCE(sk->sk_priority));
 251                 rcu_read_unlock();
 252                 return res;
 253         }
 254
 255         if (skb_is_gso(skb))
 256                 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
 257
 258         skb->encapsulation = 1;
 259         skb_reset_inner_mac_header(skb);
 260         skb_reset_inner_transport_header(skb);
 261         skb_set_inner_ipproto(skb, IPPROTO_SCTP);
 262         label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6);
 263
 264         return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr,
 265                                     &fl6->daddr, tclass, ip6_dst_hoplimit(dst),
 266                                     label, sctp_sk(sk)->udp_port, t->encap_port, false);
 267 }
 268
 269 /* Returns the dst cache entry for the given source and destination ip
 270  * addresses.
 271  */
 272 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 273                             struct flowi *fl, struct sock *sk)
 274 {
 275         struct sctp_association *asoc = t->asoc;
 276         struct dst_entry *dst = NULL;
 277         struct flowi _fl;
 278         struct flowi6 *fl6 = &_fl.u.ip6;
 279         struct sctp_bind_addr *bp;
 280         struct ipv6_pinfo *np = inet6_sk(sk);
 281         struct sctp_sockaddr_entry *laddr;
 282         union sctp_addr *daddr = &t->ipaddr;
 283         union sctp_addr dst_saddr;
 284         struct in6_addr *final_p, final;
 285         enum sctp_scope scope;
 286         __u8 matchlen = 0;
 287
 288         memset(&_fl, 0, sizeof(_fl));
 289         fl6->daddr = daddr->v6.sin6_addr;
 290         fl6->fl6_dport = daddr->v6.sin6_port;
 291         fl6->flowi6_proto = IPPROTO_SCTP;
 292         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 293                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 294         else if (asoc)
 295                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 296         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
 297                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 298
 299         if (inet6_test_bit(SNDFLOW, sk) &&
 300             (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
 301                 struct ip6_flowlabel *flowlabel;
 302
 303                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
 304                 if (IS_ERR(flowlabel))
 305                         goto out;
 306                 fl6_sock_release(flowlabel);
 307         }
 308
 309         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 310
 311         if (asoc)
 312                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 313
 314         if (saddr) {
 315                 fl6->saddr = saddr->v6.sin6_addr;
 316                 if (!fl6->fl6_sport)
 317                         fl6->fl6_sport = saddr->v6.sin6_port;
 318
 319                 pr_debug("src=%pI6 - ", &fl6->saddr);
 320         }
 321
 322         rcu_read_lock();
 323         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 324         rcu_read_unlock();
 325
 326         dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 327         if (!asoc || saddr) {
 328                 t->dst = dst;
 329                 memcpy(fl, &_fl, sizeof(_fl));
 330                 goto out;
 331         }
 332
 333         bp = &asoc->base.bind_addr;
 334         scope = sctp_scope(daddr);
 335         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 336          * to see if we can use it.
 337          */
 338         if (!IS_ERR(dst)) {
 339                 /* Walk through the bind address list and look for a bind
 340                  * address that matches the source address of the returned dst.
 341                  */
 342                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 343                 rcu_read_lock();
 344                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 345                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 346                             (laddr->state != SCTP_ADDR_SRC &&
 347                              !asoc->src_out_of_asoc_ok))
 348                                 continue;
 349
 350                         /* Do not compare against v4 addrs */
 351                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 352                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 353                                 rcu_read_unlock();
 354                                 t->dst = dst;
 355                                 memcpy(fl, &_fl, sizeof(_fl));
 356                                 goto out;
 357                         }
 358                 }
 359                 rcu_read_unlock();
 360                 /* None of the bound addresses match the source address of the
 361                  * dst. So release it.
 362                  */
 363                 dst_release(dst);
 364                 dst = NULL;
 365         }
 366
 367         /* Walk through the bind address list and try to get the
 368          * best source address for a given destination.
 369          */
 370         rcu_read_lock();
 371         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 372                 struct dst_entry *bdst;
 373                 __u8 bmatchlen;
 374
 375                 if (!laddr->valid ||
 376                     laddr->state != SCTP_ADDR_SRC ||
 377                     laddr->a.sa.sa_family != AF_INET6 ||
 378                     scope > sctp_scope(&laddr->a))
 379                         continue;
 380
 381                 fl6->saddr = laddr->a.v6.sin6_addr;
 382                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 383                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 384                 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 385
 386                 if (IS_ERR(bdst))
 387                         continue;
 388
 389                 if (ipv6_chk_addr(dev_net(bdst->dev),
 390                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 391                         if (!IS_ERR_OR_NULL(dst))
 392                                 dst_release(dst);
 393                         dst = bdst;
 394                         t->dst = dst;
 395                         memcpy(fl, &_fl, sizeof(_fl));
 396                         break;
 397                 }
 398
 399                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 400                 if (matchlen > bmatchlen) {
 401                         dst_release(bdst);
 402                         continue;
 403                 }
 404
 405                 if (!IS_ERR_OR_NULL(dst))
 406                         dst_release(dst);
 407                 dst = bdst;
 408                 matchlen = bmatchlen;
 409                 t->dst = dst;
 410                 memcpy(fl, &_fl, sizeof(_fl));
 411         }
 412         rcu_read_unlock();
 413
 414 out:
 415         if (!IS_ERR_OR_NULL(dst)) {
 416                 struct rt6_info *rt;
 417
 418                 rt = (struct rt6_info *)dst;
 419                 t->dst_cookie = rt6_get_cookie(rt);
 420                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 421                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 422                          &fl->u.ip6.saddr);
 423         } else {
 424                 t->dst = NULL;
 425                 pr_debug("no route\n");
 426         }
 427 }
 428
 429 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 430  * addresses.
 431  */
 432 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 433                                          union sctp_addr *s2)
 434 {
 435         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 436 }
 437
 438 /* Fills in the source address(saddr) based on the destination address(daddr)
 439  * and asoc's bind address list.
 440  */
 441 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 442                               struct sctp_transport *t,
 443                               struct flowi *fl)
 444 {
 445         struct flowi6 *fl6 = &fl->u.ip6;
 446         union sctp_addr *saddr = &t->saddr;
 447
 448         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 449
 450         if (t->dst) {
 451                 saddr->v6.sin6_family = AF_INET6;
 452                 saddr->v6.sin6_addr = fl6->saddr;
 453         }
 454 }
 455
 456 /* Make a copy of all potential local addresses. */
 457 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 458                                   struct net_device *dev)
 459 {
 460         struct inet6_dev *in6_dev;
 461         struct inet6_ifaddr *ifp;
 462         struct sctp_sockaddr_entry *addr;
 463
 464         rcu_read_lock();
 465         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 466                 rcu_read_unlock();
 467                 return;
 468         }
 469
 470         read_lock_bh(&in6_dev->lock);
 471         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 472                 /* Add the address to the local list.  */
 473                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 474                 if (addr) {
 475                         addr->a.v6.sin6_family = AF_INET6;
 476                         addr->a.v6.sin6_addr = ifp->addr;
 477                         addr->a.v6.sin6_scope_id = dev->ifindex;
 478                         addr->valid = 1;
 479                         INIT_LIST_HEAD(&addr->list);
 480                         list_add_tail(&addr->list, addrlist);
 481                 }
 482         }
 483
 484         read_unlock_bh(&in6_dev->lock);
 485         rcu_read_unlock();
 486 }
 487
 488 /* Copy over any ip options */
 489 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
 490 {
 491         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 492         struct ipv6_txoptions *opt;
 493
 494         newnp = inet6_sk(newsk);
 495
 496         rcu_read_lock();
 497         opt = rcu_dereference(np->opt);
 498         if (opt) {
 499                 opt = ipv6_dup_options(newsk, opt);
 500                 if (!opt)
 501                         pr_err("%s: Failed to copy ip options\n", __func__);
 502         }
 503         RCU_INIT_POINTER(newnp->opt, opt);
 504         rcu_read_unlock();
 505 }
 506
 507 /* Account for the IP options */
 508 static int sctp_v6_ip_options_len(struct sock *sk)
 509 {
 510         struct ipv6_pinfo *np = inet6_sk(sk);
 511         struct ipv6_txoptions *opt;
 512         int len = 0;
 513
 514         rcu_read_lock();
 515         opt = rcu_dereference(np->opt);
 516         if (opt)
 517                 len = opt->opt_flen + opt->opt_nflen;
 518
 519         rcu_read_unlock();
 520         return len;
 521 }
 522
 523 /* Initialize a sockaddr_storage from in incoming skb. */
 524 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 525                              int is_saddr)
 526 {
 527         /* Always called on head skb, so this is safe */
 528         struct sctphdr *sh = sctp_hdr(skb);
 529         struct sockaddr_in6 *sa = &addr->v6;
 530
 531         addr->v6.sin6_family = AF_INET6;
 532         addr->v6.sin6_flowinfo = 0; /* FIXME */
 533         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 534
 535         if (is_saddr) {
 536                 sa->sin6_port = sh->source;
 537                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 538         } else {
 539                 sa->sin6_port = sh->dest;
 540                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 541         }
 542 }
 543
 544 /* Initialize an sctp_addr from a socket. */
 545 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 546 {
 547         addr->v6.sin6_family = AF_INET6;
 548         addr->v6.sin6_port = 0;
 549         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 550 }
 551
 552 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 553 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 554 {
 555         if (addr->sa.sa_family == AF_INET) {
 556                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 557                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 558                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 559                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 560                         addr->v4.sin_addr.s_addr;
 561         } else {
 562                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 563         }
 564 }
 565
 566 /* Initialize sk->sk_daddr from sctp_addr. */
 567 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 568 {
 569         if (addr->sa.sa_family == AF_INET) {
 570                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 571                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 572                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 573                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 574         } else {
 575                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 576         }
 577 }
 578
 579 /* Initialize a sctp_addr from an address parameter. */
 580 static bool sctp_v6_from_addr_param(union sctp_addr *addr,
 581                                     union sctp_addr_param *param,
 582                                     __be16 port, int iif)
 583 {
 584         if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
 585                 return false;
 586
 587         addr->v6.sin6_family = AF_INET6;
 588         addr->v6.sin6_port = port;
 589         addr->v6.sin6_flowinfo = 0; /* BUG */
 590         addr->v6.sin6_addr = param->v6.addr;
 591         addr->v6.sin6_scope_id = iif;
 592
 593         return true;
 594 }
 595
 596 /* Initialize an address parameter from a sctp_addr and return the length
 597  * of the address parameter.
 598  */
 599 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 600                                  union sctp_addr_param *param)
 601 {
 602         int length = sizeof(struct sctp_ipv6addr_param);
 603
 604         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 605         param->v6.param_hdr.length = htons(length);
 606         param->v6.addr = addr->v6.sin6_addr;
 607
 608         return length;
 609 }
 610
 611 /* Initialize a sctp_addr from struct in6_addr. */
 612 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 613                               __be16 port)
 614 {
 615         addr->sa.sa_family = AF_INET6;
 616         addr->v6.sin6_port = port;
 617         addr->v6.sin6_flowinfo = 0;
 618         addr->v6.sin6_addr = *saddr;
 619         addr->v6.sin6_scope_id = 0;
 620 }
 621
 622 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 623                               const union sctp_addr *addr2)
 624 {
 625         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 626                 if (addr1->sa.sa_family == AF_INET &&
 627                     addr2->sa.sa_family == AF_INET6 &&
 628                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 629                     addr2->v6.sin6_addr.s6_addr32[3] ==
 630                     addr1->v4.sin_addr.s_addr)
 631                         return 1;
 632
 633                 if (addr2->sa.sa_family == AF_INET &&
 634                     addr1->sa.sa_family == AF_INET6 &&
 635                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 636                     addr1->v6.sin6_addr.s6_addr32[3] ==
 637                     addr2->v4.sin_addr.s_addr)
 638                         return 1;
 639
 640                 return 0;
 641         }
 642
 643         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 644                 return 0;
 645
 646         /* If this is a linklocal address, compare the scope_id. */
 647         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 648             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 649             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 650                 return 0;
 651
 652         return 1;
 653 }
 654
 655 /* Compare addresses exactly.
 656  * v4-mapped-v6 is also in consideration.
 657  */
 658 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 659                             const union sctp_addr *addr2)
 660 {
 661         return __sctp_v6_cmp_addr(addr1, addr2) &&
 662                addr1->v6.sin6_port == addr2->v6.sin6_port;
 663 }
 664
 665 /* Initialize addr struct to INADDR_ANY. */
 666 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 667 {
 668         memset(addr, 0x00, sizeof(union sctp_addr));
 669         addr->v6.sin6_family = AF_INET6;
 670         addr->v6.sin6_port = port;
 671 }
 672
 673 /* Is this a wildcard address? */
 674 static int sctp_v6_is_any(const union sctp_addr *addr)
 675 {
 676         return ipv6_addr_any(&addr->v6.sin6_addr);
 677 }
 678
 679 /* Should this be available for binding?   */
 680 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 681 {
 682         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 683         struct sock *sk = &sp->inet.sk;
 684         struct net *net = sock_net(sk);
 685         struct net_device *dev = NULL;
 686         int type;
 687
 688         type = ipv6_addr_type(in6);
 689         if (IPV6_ADDR_ANY == type)
 690                 return 1;
 691         if (type == IPV6_ADDR_MAPPED) {
 692                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 693                         return 0;
 694                 sctp_v6_map_v4(addr);
 695                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 696         }
 697         if (!(type & IPV6_ADDR_UNICAST))
 698                 return 0;
 699
 700         if (sk->sk_bound_dev_if) {
 701                 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
 702                 if (!dev)
 703                         return 0;
 704         }
 705
 706         return ipv6_can_nonlocal_bind(net, &sp->inet) ||
 707                ipv6_chk_addr(net, in6, dev, 0);
 708 }
 709
 710 /* This function checks if the address is a valid address to be used for
 711  * SCTP.
 712  *
 713  * Output:
 714  * Return 0 - If the address is a non-unicast or an illegal address.
 715  * Return 1 - If the address is a unicast.
 716  */
 717 static int sctp_v6_addr_valid(union sctp_addr *addr,
 718                               struct sctp_sock *sp,
 719                               const struct sk_buff *skb)
 720 {
 721         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 722
 723         /* Support v4-mapped-v6 address. */
 724         if (ret == IPV6_ADDR_MAPPED) {
 725                 /* Note: This routine is used in input, so v4-mapped-v6
 726                  * are disallowed here when there is no sctp_sock.
 727                  */
 728                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 729                         return 0;
 730                 sctp_v6_map_v4(addr);
 731                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 732         }
 733
 734         /* Is this a non-unicast address */
 735         if (!(ret & IPV6_ADDR_UNICAST))
 736                 return 0;
 737
 738         return 1;
 739 }
 740
 741 /* What is the scope of 'addr'?  */
 742 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 743 {
 744         enum sctp_scope retval;
 745         int v6scope;
 746
 747         /* The IPv6 scope is really a set of bit fields.
 748          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 749          */
 750
 751         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 752         switch (v6scope) {
 753         case IFA_HOST:
 754                 retval = SCTP_SCOPE_LOOPBACK;
 755                 break;
 756         case IFA_LINK:
 757                 retval = SCTP_SCOPE_LINK;
 758                 break;
 759         case IFA_SITE:
 760                 retval = SCTP_SCOPE_PRIVATE;
 761                 break;
 762         default:
 763                 retval = SCTP_SCOPE_GLOBAL;
 764                 break;
 765         }
 766
 767         return retval;
 768 }
 769
 770 /* Create and initialize a new sk for the socket to be returned by accept(). */
 771 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 772                                              struct sctp_association *asoc,
 773                                              bool kern)
 774 {
 775         struct sock *newsk;
 776         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 777         struct sctp6_sock *newsctp6sk;
 778
 779         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 780         if (!newsk)
 781                 goto out;
 782
 783         sock_init_data(NULL, newsk);
 784
 785         sctp_copy_sock(newsk, sk, asoc);
 786         sock_reset_flag(sk, SOCK_ZAPPED);
 787
 788         newsctp6sk = (struct sctp6_sock *)newsk;
 789         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 790
 791         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 792
 793         newnp = inet6_sk(newsk);
 794
 795         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 796         newnp->ipv6_mc_list = NULL;
 797         newnp->ipv6_ac_list = NULL;
 798         newnp->ipv6_fl_list = NULL;
 799
 800         sctp_v6_copy_ip_options(sk, newsk);
 801
 802         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 803          * and getpeername().
 804          */
 805         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 806
 807         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 808
 809         if (newsk->sk_prot->init(newsk)) {
 810                 sk_common_release(newsk);
 811                 newsk = NULL;
 812         }
 813
 814 out:
 815         return newsk;
 816 }
 817
 818 /* Format a sockaddr for return to user space. This makes sure the return is
 819  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 820  */
 821 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 822 {
 823         if (sp->v4mapped) {
 824                 if (addr->sa.sa_family == AF_INET)
 825                         sctp_v4_map_v6(addr);
 826         } else {
 827                 if (addr->sa.sa_family == AF_INET6 &&
 828                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 829                         sctp_v6_map_v4(addr);
 830         }
 831
 832         if (addr->sa.sa_family == AF_INET) {
 833                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 834                 return sizeof(struct sockaddr_in);
 835         }
 836         return sizeof(struct sockaddr_in6);
 837 }
 838
 839 /* Where did this skb come from?  */
 840 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 841 {
 842         return inet6_iif(skb);
 843 }
 844
 845 static int sctp_v6_skb_sdif(const struct sk_buff *skb)
 846 {
 847         return inet6_sdif(skb);
 848 }
 849
 850 /* Was this packet marked by Explicit Congestion Notification? */
 851 static int sctp_v6_is_ce(const struct sk_buff *skb)
 852 {
 853         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 854 }
 855
 856 /* Dump the v6 addr to the seq file. */
 857 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 858 {
 859         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 860 }
 861
 862 static void sctp_v6_ecn_capable(struct sock *sk)
 863 {
 864         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 865 }
 866
 867 /* Initialize a PF_INET msgname from a ulpevent. */
 868 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 869                                      char *msgname, int *addrlen)
 870 {
 871         union sctp_addr *addr;
 872         struct sctp_association *asoc;
 873         union sctp_addr *paddr;
 874
 875         if (!msgname)
 876                 return;
 877
 878         addr = (union sctp_addr *)msgname;
 879         asoc = event->asoc;
 880         paddr = &asoc->peer.primary_addr;
 881
 882         if (paddr->sa.sa_family == AF_INET) {
 883                 addr->v4.sin_family = AF_INET;
 884                 addr->v4.sin_port = htons(asoc->peer.port);
 885                 addr->v4.sin_addr = paddr->v4.sin_addr;
 886         } else {
 887                 addr->v6.sin6_family = AF_INET6;
 888                 addr->v6.sin6_flowinfo = 0;
 889                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 890                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 891                 else
 892                         addr->v6.sin6_scope_id = 0;
 893                 addr->v6.sin6_port = htons(asoc->peer.port);
 894                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 895         }
 896
 897         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 898 }
 899
 900 /* Initialize a msg_name from an inbound skb. */
 901 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 902                                    int *addr_len)
 903 {
 904         union sctp_addr *addr;
 905         struct sctphdr *sh;
 906
 907         if (!msgname)
 908                 return;
 909
 910         addr = (union sctp_addr *)msgname;
 911         sh = sctp_hdr(skb);
 912
 913         if (ip_hdr(skb)->version == 4) {
 914                 addr->v4.sin_family = AF_INET;
 915                 addr->v4.sin_port = sh->source;
 916                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 917         } else {
 918                 addr->v6.sin6_family = AF_INET6;
 919                 addr->v6.sin6_flowinfo = 0;
 920                 addr->v6.sin6_port = sh->source;
 921                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 922                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 923                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 924                 else
 925                         addr->v6.sin6_scope_id = 0;
 926         }
 927
 928         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 929 }
 930
 931 /* Do we support this AF? */
 932 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 933 {
 934         switch (family) {
 935         case AF_INET6:
 936                 return 1;
 937         /* v4-mapped-v6 addresses */
 938         case AF_INET:
 939                 if (!ipv6_only_sock(sctp_opt2sk(sp)))
 940                         return 1;
 941                 fallthrough;
 942         default:
 943                 return 0;
 944         }
 945 }
 946
 947 /* Address matching with wildcards allowed.  This extra level
 948  * of indirection lets us choose whether a PF_INET6 should
 949  * disallow any v4 addresses if we so choose.
 950  */
 951 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 952                                const union sctp_addr *addr2,
 953                                struct sctp_sock *opt)
 954 {
 955         struct sock *sk = sctp_opt2sk(opt);
 956         struct sctp_af *af1, *af2;
 957
 958         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 959         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 960
 961         if (!af1 || !af2)
 962                 return 0;
 963
 964         /* If the socket is IPv6 only, v4 addrs will not match */
 965         if (ipv6_only_sock(sk) && af1 != af2)
 966                 return 0;
 967
 968         /* Today, wildcard AF_INET/AF_INET6. */
 969         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 970                 return 1;
 971
 972         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 973                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 974
 975         return __sctp_v6_cmp_addr(addr1, addr2);
 976 }
 977
 978 /* Verify that the provided sockaddr looks bindable.   Common verification,
 979  * has already been taken care of.
 980  */
 981 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 982 {
 983         struct sctp_af *af;
 984
 985         /* ASSERT: address family has already been verified. */
 986         if (addr->sa.sa_family != AF_INET6)
 987                 af = sctp_get_af_specific(addr->sa.sa_family);
 988         else {
 989                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 990                 struct net_device *dev;
 991
 992                 if (type & IPV6_ADDR_LINKLOCAL) {
 993                         struct net *net;
 994                         if (!addr->v6.sin6_scope_id)
 995                                 return 0;
 996                         net = sock_net(&opt->inet.sk);
 997                         rcu_read_lock();
 998                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 999                         if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) ||
1000                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
1001                                                     dev, 0))) {
1002                                 rcu_read_unlock();
1003                                 return 0;
1004                         }
1005                         rcu_read_unlock();
1006                 }
1007
1008                 af = opt->pf->af;
1009         }
1010         return af->available(addr, opt);
1011 }
1012
1013 /* Verify that the provided sockaddr looks sendable.   Common verification,
1014  * has already been taken care of.
1015  */
1016 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
1017 {
1018         struct sctp_af *af = NULL;
1019
1020         /* ASSERT: address family has already been verified. */
1021         if (addr->sa.sa_family != AF_INET6)
1022                 af = sctp_get_af_specific(addr->sa.sa_family);
1023         else {
1024                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
1025                 struct net_device *dev;
1026
1027                 if (type & IPV6_ADDR_LINKLOCAL) {
1028                         if (!addr->v6.sin6_scope_id)
1029                                 return 0;
1030                         rcu_read_lock();
1031                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
1032                                                    addr->v6.sin6_scope_id);
1033                         rcu_read_unlock();
1034                         if (!dev)
1035                                 return 0;
1036                 }
1037                 af = opt->pf->af;
1038         }
1039
1040         return af != NULL;
1041 }
1042
1043 /* Fill in Supported Address Type information for INIT and INIT-ACK
1044  * chunks.   Note: In the future, we may want to look at sock options
1045  * to determine whether a PF_INET6 socket really wants to have IPV4
1046  * addresses.
1047  * Returns number of addresses supported.
1048  */
1049 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
1050                                       __be16 *types)
1051 {
1052         types[0] = SCTP_PARAM_IPV6_ADDRESS;
1053         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1054                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
1055                 return 2;
1056         }
1057         return 1;
1058 }
1059
1060 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1061 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1062                         int peer)
1063 {
1064         int rc;
1065
1066         rc = inet6_getname(sock, uaddr, peer);
1067
1068         if (rc < 0)
1069                 return rc;
1070
1071         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1072                                           (union sctp_addr *)uaddr);
1073
1074         return rc;
1075 }
1076
1077 static const struct proto_ops inet6_seqpacket_ops = {
1078         .family            = PF_INET6,
1079         .owner             = THIS_MODULE,
1080         .release           = inet6_release,
1081         .bind              = inet6_bind,
1082         .connect           = sctp_inet_connect,
1083         .socketpair        = sock_no_socketpair,
1084         .accept            = inet_accept,
1085         .getname           = sctp_getname,
1086         .poll              = sctp_poll,
1087         .ioctl             = inet6_ioctl,
1088         .gettstamp         = sock_gettstamp,
1089         .listen            = sctp_inet_listen,
1090         .shutdown          = inet_shutdown,
1091         .setsockopt        = sock_common_setsockopt,
1092         .getsockopt        = sock_common_getsockopt,
1093         .sendmsg           = inet_sendmsg,
1094         .recvmsg           = inet_recvmsg,
1095         .mmap              = sock_no_mmap,
1096 #ifdef CONFIG_COMPAT
1097         .compat_ioctl      = inet6_compat_ioctl,
1098 #endif
1099 };
1100
1101 static struct inet_protosw sctpv6_seqpacket_protosw = {
1102         .type          = SOCK_SEQPACKET,
1103         .protocol      = IPPROTO_SCTP,
1104         .prot          = &sctpv6_prot,
1105         .ops           = &inet6_seqpacket_ops,
1106         .flags         = SCTP_PROTOSW_FLAG
1107 };
1108 static struct inet_protosw sctpv6_stream_protosw = {
1109         .type          = SOCK_STREAM,
1110         .protocol      = IPPROTO_SCTP,
1111         .prot          = &sctpv6_prot,
1112         .ops           = &inet6_seqpacket_ops,
1113         .flags         = SCTP_PROTOSW_FLAG,
1114 };
1115
1116 static int sctp6_rcv(struct sk_buff *skb)
1117 {
1118         SCTP_INPUT_CB(skb)->encap_port = 0;
1119         return sctp_rcv(skb) ? -1 : 0;
1120 }
1121
1122 static const struct inet6_protocol sctpv6_protocol = {
1123         .handler      = sctp6_rcv,
1124         .err_handler  = sctp_v6_err,
1125         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1126 };
1127
1128 static struct sctp_af sctp_af_inet6 = {
1129         .sa_family         = AF_INET6,
1130         .sctp_xmit         = sctp_v6_xmit,
1131         .setsockopt        = ipv6_setsockopt,
1132         .getsockopt        = ipv6_getsockopt,
1133         .get_dst           = sctp_v6_get_dst,
1134         .get_saddr         = sctp_v6_get_saddr,
1135         .copy_addrlist     = sctp_v6_copy_addrlist,
1136         .from_skb          = sctp_v6_from_skb,
1137         .from_sk           = sctp_v6_from_sk,
1138         .from_addr_param   = sctp_v6_from_addr_param,
1139         .to_addr_param     = sctp_v6_to_addr_param,
1140         .cmp_addr          = sctp_v6_cmp_addr,
1141         .scope             = sctp_v6_scope,
1142         .addr_valid        = sctp_v6_addr_valid,
1143         .inaddr_any        = sctp_v6_inaddr_any,
1144         .is_any            = sctp_v6_is_any,
1145         .available         = sctp_v6_available,
1146         .skb_iif           = sctp_v6_skb_iif,
1147         .skb_sdif          = sctp_v6_skb_sdif,
1148         .is_ce             = sctp_v6_is_ce,
1149         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1150         .ecn_capable       = sctp_v6_ecn_capable,
1151         .net_header_len    = sizeof(struct ipv6hdr),
1152         .sockaddr_len      = sizeof(struct sockaddr_in6),
1153         .ip_options_len    = sctp_v6_ip_options_len,
1154 };
1155
1156 static struct sctp_pf sctp_pf_inet6 = {
1157         .event_msgname = sctp_inet6_event_msgname,
1158         .skb_msgname   = sctp_inet6_skb_msgname,
1159         .af_supported  = sctp_inet6_af_supported,
1160         .cmp_addr      = sctp_inet6_cmp_addr,
1161         .bind_verify   = sctp_inet6_bind_verify,
1162         .send_verify   = sctp_inet6_send_verify,
1163         .supported_addrs = sctp_inet6_supported_addrs,
1164         .create_accept_sk = sctp_v6_create_accept_sk,
1165         .addr_to_user  = sctp_v6_addr_to_user,
1166         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1167         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1168         .copy_ip_options = sctp_v6_copy_ip_options,
1169         .af            = &sctp_af_inet6,
1170 };
1171
1172 /* Initialize IPv6 support and register with socket layer.  */
1173 void sctp_v6_pf_init(void)
1174 {
1175         /* Register the SCTP specific PF_INET6 functions. */
1176         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1177
1178         /* Register the SCTP specific AF_INET6 functions. */
1179         sctp_register_af(&sctp_af_inet6);
1180 }
1181
1182 void sctp_v6_pf_exit(void)
1183 {
1184         list_del(&sctp_af_inet6.list);
1185 }
1186
1187 /* Initialize IPv6 support and register with socket layer.  */
1188 int sctp_v6_protosw_init(void)
1189 {
1190         int rc;
1191
1192         rc = proto_register(&sctpv6_prot, 1);
1193         if (rc)
1194                 return rc;
1195
1196         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1197         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1198         inet6_register_protosw(&sctpv6_stream_protosw);
1199
1200         return 0;
1201 }
1202
1203 void sctp_v6_protosw_exit(void)
1204 {
1205         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1206         inet6_unregister_protosw(&sctpv6_stream_protosw);
1207         proto_unregister(&sctpv6_prot);
1208 }
1209
1210
1211 /* Register with inet6 layer. */
1212 int sctp_v6_add_protocol(void)
1213 {
1214         /* Register notifier for inet6 address additions/deletions. */
1215         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1216
1217         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1218                 return -EAGAIN;
1219
1220         return 0;
1221 }
1222
1223 /* Unregister with inet6 layer. */
1224 void sctp_v6_del_protocol(void)
1225 {
1226         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1227         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1228 }