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 <linux-sctp@vger.kernel.org>
  15  *
  16  * Written or modified by:
  17  *    Le Yanqun             <yanqun.le@nokia.com>
  18  *    Hui Huang             <hui.huang@nokia.com>
  19  *    La Monte H.P. Yarroll <piggy@acm.org>
  20  *    Sridhar Samudrala     <sri@us.ibm.com>
  21  *    Jon Grimm             <jgrimm@us.ibm.com>
  22  *    Ardelle Fan           <ardelle.fan@intel.com>
  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                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 106                                 found = 1;
 107                                 addr->valid = 0;
 108                                 list_del_rcu(&addr->list);
 109                                 break;
 110                         }
 111                 }
 112                 spin_unlock_bh(&net->sctp.local_addr_lock);
 113                 if (found)
 114                         kfree_rcu(addr, rcu);
 115                 break;
 116         }
 117
 118         return NOTIFY_DONE;
 119 }
 120
 121 static struct notifier_block sctp_inet6addr_notifier = {
 122         .notifier_call = sctp_inet6addr_event,
 123 };
 124
 125 /* ICMP error handler. */
 126 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 127                         u8 type, u8 code, int offset, __be32 info)
 128 {
 129         struct inet6_dev *idev;
 130         struct sock *sk;
 131         struct sctp_association *asoc;
 132         struct sctp_transport *transport;
 133         struct ipv6_pinfo *np;
 134         __u16 saveip, savesctp;
 135         int err, ret = 0;
 136         struct net *net = dev_net(skb->dev);
 137
 138         idev = in6_dev_get(skb->dev);
 139
 140         /* Fix up skb to look at the embedded net header. */
 141         saveip   = skb->network_header;
 142         savesctp = skb->transport_header;
 143         skb_reset_network_header(skb);
 144         skb_set_transport_header(skb, offset);
 145         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 146         /* Put back, the original pointers. */
 147         skb->network_header   = saveip;
 148         skb->transport_header = savesctp;
 149         if (!sk) {
 150                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
 151                 ret = -ENOENT;
 152                 goto out;
 153         }
 154
 155         /* Warning:  The sock lock is held.  Remember to call
 156          * sctp_err_finish!
 157          */
 158
 159         switch (type) {
 160         case ICMPV6_PKT_TOOBIG:
 161                 if (ip6_sk_accept_pmtu(sk))
 162                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 163                 goto out_unlock;
 164         case ICMPV6_PARAMPROB:
 165                 if (ICMPV6_UNK_NEXTHDR == code) {
 166                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 167                         goto out_unlock;
 168                 }
 169                 break;
 170         case NDISC_REDIRECT:
 171                 sctp_icmp_redirect(sk, transport, skb);
 172                 goto out_unlock;
 173         default:
 174                 break;
 175         }
 176
 177         np = inet6_sk(sk);
 178         icmpv6_err_convert(type, code, &err);
 179         if (!sock_owned_by_user(sk) && np->recverr) {
 180                 sk->sk_err = err;
 181                 sk->sk_error_report(sk);
 182         } else {  /* Only an error on timeout */
 183                 sk->sk_err_soft = err;
 184         }
 185
 186 out_unlock:
 187         sctp_err_finish(sk, transport);
 188 out:
 189         if (likely(idev != NULL))
 190                 in6_dev_put(idev);
 191
 192         return ret;
 193 }
 194
 195 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t)
 196 {
 197         struct dst_entry *dst = dst_clone(t->dst);
 198         struct flowi6 *fl6 = &t->fl.u.ip6;
 199         struct sock *sk = skb->sk;
 200         struct ipv6_pinfo *np = inet6_sk(sk);
 201         __u8 tclass = np->tclass;
 202         __be32 label;
 203
 204         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 205                  skb->len, &fl6->saddr, &fl6->daddr);
 206
 207         if (t->dscp & SCTP_DSCP_SET_MASK)
 208                 tclass = t->dscp & SCTP_DSCP_VAL_MASK;
 209
 210         if (INET_ECN_is_capable(tclass))
 211                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 212
 213         if (!(t->param_flags & SPP_PMTUD_ENABLE))
 214                 skb->ignore_df = 1;
 215
 216         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 217
 218         if (!t->encap_port || !sctp_sk(sk)->udp_port) {
 219                 int res;
 220
 221                 skb_dst_set(skb, dst);
 222                 rcu_read_lock();
 223                 res = ip6_xmit(sk, skb, fl6, sk->sk_mark,
 224                                rcu_dereference(np->opt),
 225                                tclass, sk->sk_priority);
 226                 rcu_read_unlock();
 227                 return res;
 228         }
 229
 230         if (skb_is_gso(skb))
 231                 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
 232
 233         skb->encapsulation = 1;
 234         skb_reset_inner_mac_header(skb);
 235         skb_reset_inner_transport_header(skb);
 236         skb_set_inner_ipproto(skb, IPPROTO_SCTP);
 237         label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6);
 238
 239         return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr,
 240                                     &fl6->daddr, tclass, ip6_dst_hoplimit(dst),
 241                                     label, sctp_sk(sk)->udp_port, t->encap_port, false);
 242 }
 243
 244 /* Returns the dst cache entry for the given source and destination ip
 245  * addresses.
 246  */
 247 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 248                             struct flowi *fl, struct sock *sk)
 249 {
 250         struct sctp_association *asoc = t->asoc;
 251         struct dst_entry *dst = NULL;
 252         struct flowi _fl;
 253         struct flowi6 *fl6 = &_fl.u.ip6;
 254         struct sctp_bind_addr *bp;
 255         struct ipv6_pinfo *np = inet6_sk(sk);
 256         struct sctp_sockaddr_entry *laddr;
 257         union sctp_addr *daddr = &t->ipaddr;
 258         union sctp_addr dst_saddr;
 259         struct in6_addr *final_p, final;
 260         enum sctp_scope scope;
 261         __u8 matchlen = 0;
 262
 263         memset(&_fl, 0, sizeof(_fl));
 264         fl6->daddr = daddr->v6.sin6_addr;
 265         fl6->fl6_dport = daddr->v6.sin6_port;
 266         fl6->flowi6_proto = IPPROTO_SCTP;
 267         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 268                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 269         else if (asoc)
 270                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 271         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
 272                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 273
 274         if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
 275                 struct ip6_flowlabel *flowlabel;
 276
 277                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
 278                 if (IS_ERR(flowlabel))
 279                         goto out;
 280                 fl6_sock_release(flowlabel);
 281         }
 282
 283         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 284
 285         if (asoc)
 286                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 287
 288         if (saddr) {
 289                 fl6->saddr = saddr->v6.sin6_addr;
 290                 if (!fl6->fl6_sport)
 291                         fl6->fl6_sport = saddr->v6.sin6_port;
 292
 293                 pr_debug("src=%pI6 - ", &fl6->saddr);
 294         }
 295
 296         rcu_read_lock();
 297         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 298         rcu_read_unlock();
 299
 300         dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 301         if (!asoc || saddr) {
 302                 t->dst = dst;
 303                 memcpy(fl, &_fl, sizeof(_fl));
 304                 goto out;
 305         }
 306
 307         bp = &asoc->base.bind_addr;
 308         scope = sctp_scope(daddr);
 309         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 310          * to see if we can use it.
 311          */
 312         if (!IS_ERR(dst)) {
 313                 /* Walk through the bind address list and look for a bind
 314                  * address that matches the source address of the returned dst.
 315                  */
 316                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 317                 rcu_read_lock();
 318                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 319                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 320                             (laddr->state != SCTP_ADDR_SRC &&
 321                              !asoc->src_out_of_asoc_ok))
 322                                 continue;
 323
 324                         /* Do not compare against v4 addrs */
 325                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 326                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 327                                 rcu_read_unlock();
 328                                 t->dst = dst;
 329                                 memcpy(fl, &_fl, sizeof(_fl));
 330                                 goto out;
 331                         }
 332                 }
 333                 rcu_read_unlock();
 334                 /* None of the bound addresses match the source address of the
 335                  * dst. So release it.
 336                  */
 337                 dst_release(dst);
 338                 dst = NULL;
 339         }
 340
 341         /* Walk through the bind address list and try to get the
 342          * best source address for a given destination.
 343          */
 344         rcu_read_lock();
 345         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 346                 struct dst_entry *bdst;
 347                 __u8 bmatchlen;
 348
 349                 if (!laddr->valid ||
 350                     laddr->state != SCTP_ADDR_SRC ||
 351                     laddr->a.sa.sa_family != AF_INET6 ||
 352                     scope > sctp_scope(&laddr->a))
 353                         continue;
 354
 355                 fl6->saddr = laddr->a.v6.sin6_addr;
 356                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 357                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 358                 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 359
 360                 if (IS_ERR(bdst))
 361                         continue;
 362
 363                 if (ipv6_chk_addr(dev_net(bdst->dev),
 364                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 365                         if (!IS_ERR_OR_NULL(dst))
 366                                 dst_release(dst);
 367                         dst = bdst;
 368                         t->dst = dst;
 369                         memcpy(fl, &_fl, sizeof(_fl));
 370                         break;
 371                 }
 372
 373                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 374                 if (matchlen > bmatchlen) {
 375                         dst_release(bdst);
 376                         continue;
 377                 }
 378
 379                 if (!IS_ERR_OR_NULL(dst))
 380                         dst_release(dst);
 381                 dst = bdst;
 382                 matchlen = bmatchlen;
 383                 t->dst = dst;
 384                 memcpy(fl, &_fl, sizeof(_fl));
 385         }
 386         rcu_read_unlock();
 387
 388 out:
 389         if (!IS_ERR_OR_NULL(dst)) {
 390                 struct rt6_info *rt;
 391
 392                 rt = (struct rt6_info *)dst;
 393                 t->dst_cookie = rt6_get_cookie(rt);
 394                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 395                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 396                          &fl->u.ip6.saddr);
 397         } else {
 398                 t->dst = NULL;
 399                 pr_debug("no route\n");
 400         }
 401 }
 402
 403 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 404  * addresses.
 405  */
 406 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 407                                          union sctp_addr *s2)
 408 {
 409         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 410 }
 411
 412 /* Fills in the source address(saddr) based on the destination address(daddr)
 413  * and asoc's bind address list.
 414  */
 415 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 416                               struct sctp_transport *t,
 417                               struct flowi *fl)
 418 {
 419         struct flowi6 *fl6 = &fl->u.ip6;
 420         union sctp_addr *saddr = &t->saddr;
 421
 422         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 423
 424         if (t->dst) {
 425                 saddr->v6.sin6_family = AF_INET6;
 426                 saddr->v6.sin6_addr = fl6->saddr;
 427         }
 428 }
 429
 430 /* Make a copy of all potential local addresses. */
 431 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 432                                   struct net_device *dev)
 433 {
 434         struct inet6_dev *in6_dev;
 435         struct inet6_ifaddr *ifp;
 436         struct sctp_sockaddr_entry *addr;
 437
 438         rcu_read_lock();
 439         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 440                 rcu_read_unlock();
 441                 return;
 442         }
 443
 444         read_lock_bh(&in6_dev->lock);
 445         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 446                 /* Add the address to the local list.  */
 447                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 448                 if (addr) {
 449                         addr->a.v6.sin6_family = AF_INET6;
 450                         addr->a.v6.sin6_addr = ifp->addr;
 451                         addr->a.v6.sin6_scope_id = dev->ifindex;
 452                         addr->valid = 1;
 453                         INIT_LIST_HEAD(&addr->list);
 454                         list_add_tail(&addr->list, addrlist);
 455                 }
 456         }
 457
 458         read_unlock_bh(&in6_dev->lock);
 459         rcu_read_unlock();
 460 }
 461
 462 /* Copy over any ip options */
 463 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
 464 {
 465         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 466         struct ipv6_txoptions *opt;
 467
 468         newnp = inet6_sk(newsk);
 469
 470         rcu_read_lock();
 471         opt = rcu_dereference(np->opt);
 472         if (opt) {
 473                 opt = ipv6_dup_options(newsk, opt);
 474                 if (!opt)
 475                         pr_err("%s: Failed to copy ip options\n", __func__);
 476         }
 477         RCU_INIT_POINTER(newnp->opt, opt);
 478         rcu_read_unlock();
 479 }
 480
 481 /* Account for the IP options */
 482 static int sctp_v6_ip_options_len(struct sock *sk)
 483 {
 484         struct ipv6_pinfo *np = inet6_sk(sk);
 485         struct ipv6_txoptions *opt;
 486         int len = 0;
 487
 488         rcu_read_lock();
 489         opt = rcu_dereference(np->opt);
 490         if (opt)
 491                 len = opt->opt_flen + opt->opt_nflen;
 492
 493         rcu_read_unlock();
 494         return len;
 495 }
 496
 497 /* Initialize a sockaddr_storage from in incoming skb. */
 498 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 499                              int is_saddr)
 500 {
 501         /* Always called on head skb, so this is safe */
 502         struct sctphdr *sh = sctp_hdr(skb);
 503         struct sockaddr_in6 *sa = &addr->v6;
 504
 505         addr->v6.sin6_family = AF_INET6;
 506         addr->v6.sin6_flowinfo = 0; /* FIXME */
 507         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 508
 509         if (is_saddr) {
 510                 sa->sin6_port = sh->source;
 511                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 512         } else {
 513                 sa->sin6_port = sh->dest;
 514                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 515         }
 516 }
 517
 518 /* Initialize an sctp_addr from a socket. */
 519 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 520 {
 521         addr->v6.sin6_family = AF_INET6;
 522         addr->v6.sin6_port = 0;
 523         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 524 }
 525
 526 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 527 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 528 {
 529         if (addr->sa.sa_family == AF_INET) {
 530                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 531                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 532                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 533                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 534                         addr->v4.sin_addr.s_addr;
 535         } else {
 536                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 537         }
 538 }
 539
 540 /* Initialize sk->sk_daddr from sctp_addr. */
 541 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 542 {
 543         if (addr->sa.sa_family == AF_INET) {
 544                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 545                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 546                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 547                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 548         } else {
 549                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 550         }
 551 }
 552
 553 /* Initialize a sctp_addr from an address parameter. */
 554 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 555                                     union sctp_addr_param *param,
 556                                     __be16 port, int iif)
 557 {
 558         addr->v6.sin6_family = AF_INET6;
 559         addr->v6.sin6_port = port;
 560         addr->v6.sin6_flowinfo = 0; /* BUG */
 561         addr->v6.sin6_addr = param->v6.addr;
 562         addr->v6.sin6_scope_id = iif;
 563 }
 564
 565 /* Initialize an address parameter from a sctp_addr and return the length
 566  * of the address parameter.
 567  */
 568 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 569                                  union sctp_addr_param *param)
 570 {
 571         int length = sizeof(struct sctp_ipv6addr_param);
 572
 573         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 574         param->v6.param_hdr.length = htons(length);
 575         param->v6.addr = addr->v6.sin6_addr;
 576
 577         return length;
 578 }
 579
 580 /* Initialize a sctp_addr from struct in6_addr. */
 581 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 582                               __be16 port)
 583 {
 584         addr->sa.sa_family = AF_INET6;
 585         addr->v6.sin6_port = port;
 586         addr->v6.sin6_flowinfo = 0;
 587         addr->v6.sin6_addr = *saddr;
 588         addr->v6.sin6_scope_id = 0;
 589 }
 590
 591 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 592                               const union sctp_addr *addr2)
 593 {
 594         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 595                 if (addr1->sa.sa_family == AF_INET &&
 596                     addr2->sa.sa_family == AF_INET6 &&
 597                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 598                     addr2->v6.sin6_addr.s6_addr32[3] ==
 599                     addr1->v4.sin_addr.s_addr)
 600                         return 1;
 601
 602                 if (addr2->sa.sa_family == AF_INET &&
 603                     addr1->sa.sa_family == AF_INET6 &&
 604                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 605                     addr1->v6.sin6_addr.s6_addr32[3] ==
 606                     addr2->v4.sin_addr.s_addr)
 607                         return 1;
 608
 609                 return 0;
 610         }
 611
 612         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 613                 return 0;
 614
 615         /* If this is a linklocal address, compare the scope_id. */
 616         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 617             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 618             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 619                 return 0;
 620
 621         return 1;
 622 }
 623
 624 /* Compare addresses exactly.
 625  * v4-mapped-v6 is also in consideration.
 626  */
 627 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 628                             const union sctp_addr *addr2)
 629 {
 630         return __sctp_v6_cmp_addr(addr1, addr2) &&
 631                addr1->v6.sin6_port == addr2->v6.sin6_port;
 632 }
 633
 634 /* Initialize addr struct to INADDR_ANY. */
 635 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 636 {
 637         memset(addr, 0x00, sizeof(union sctp_addr));
 638         addr->v6.sin6_family = AF_INET6;
 639         addr->v6.sin6_port = port;
 640 }
 641
 642 /* Is this a wildcard address? */
 643 static int sctp_v6_is_any(const union sctp_addr *addr)
 644 {
 645         return ipv6_addr_any(&addr->v6.sin6_addr);
 646 }
 647
 648 /* Should this be available for binding?   */
 649 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 650 {
 651         int type;
 652         struct net *net = sock_net(&sp->inet.sk);
 653         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 654
 655         type = ipv6_addr_type(in6);
 656         if (IPV6_ADDR_ANY == type)
 657                 return 1;
 658         if (type == IPV6_ADDR_MAPPED) {
 659                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 660                         return 0;
 661                 sctp_v6_map_v4(addr);
 662                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 663         }
 664         if (!(type & IPV6_ADDR_UNICAST))
 665                 return 0;
 666
 667         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 668                 ipv6_chk_addr(net, in6, NULL, 0);
 669 }
 670
 671 /* This function checks if the address is a valid address to be used for
 672  * SCTP.
 673  *
 674  * Output:
 675  * Return 0 - If the address is a non-unicast or an illegal address.
 676  * Return 1 - If the address is a unicast.
 677  */
 678 static int sctp_v6_addr_valid(union sctp_addr *addr,
 679                               struct sctp_sock *sp,
 680                               const struct sk_buff *skb)
 681 {
 682         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 683
 684         /* Support v4-mapped-v6 address. */
 685         if (ret == IPV6_ADDR_MAPPED) {
 686                 /* Note: This routine is used in input, so v4-mapped-v6
 687                  * are disallowed here when there is no sctp_sock.
 688                  */
 689                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 690                         return 0;
 691                 sctp_v6_map_v4(addr);
 692                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 693         }
 694
 695         /* Is this a non-unicast address */
 696         if (!(ret & IPV6_ADDR_UNICAST))
 697                 return 0;
 698
 699         return 1;
 700 }
 701
 702 /* What is the scope of 'addr'?  */
 703 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 704 {
 705         enum sctp_scope retval;
 706         int v6scope;
 707
 708         /* The IPv6 scope is really a set of bit fields.
 709          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 710          */
 711
 712         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 713         switch (v6scope) {
 714         case IFA_HOST:
 715                 retval = SCTP_SCOPE_LOOPBACK;
 716                 break;
 717         case IFA_LINK:
 718                 retval = SCTP_SCOPE_LINK;
 719                 break;
 720         case IFA_SITE:
 721                 retval = SCTP_SCOPE_PRIVATE;
 722                 break;
 723         default:
 724                 retval = SCTP_SCOPE_GLOBAL;
 725                 break;
 726         }
 727
 728         return retval;
 729 }
 730
 731 /* Create and initialize a new sk for the socket to be returned by accept(). */
 732 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 733                                              struct sctp_association *asoc,
 734                                              bool kern)
 735 {
 736         struct sock *newsk;
 737         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 738         struct sctp6_sock *newsctp6sk;
 739
 740         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 741         if (!newsk)
 742                 goto out;
 743
 744         sock_init_data(NULL, newsk);
 745
 746         sctp_copy_sock(newsk, sk, asoc);
 747         sock_reset_flag(sk, SOCK_ZAPPED);
 748
 749         newsctp6sk = (struct sctp6_sock *)newsk;
 750         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 751
 752         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 753
 754         newnp = inet6_sk(newsk);
 755
 756         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 757         newnp->ipv6_mc_list = NULL;
 758         newnp->ipv6_ac_list = NULL;
 759         newnp->ipv6_fl_list = NULL;
 760
 761         sctp_v6_copy_ip_options(sk, newsk);
 762
 763         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 764          * and getpeername().
 765          */
 766         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 767
 768         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 769
 770         sk_refcnt_debug_inc(newsk);
 771
 772         if (newsk->sk_prot->init(newsk)) {
 773                 sk_common_release(newsk);
 774                 newsk = NULL;
 775         }
 776
 777 out:
 778         return newsk;
 779 }
 780
 781 /* Format a sockaddr for return to user space. This makes sure the return is
 782  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 783  */
 784 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 785 {
 786         if (sp->v4mapped) {
 787                 if (addr->sa.sa_family == AF_INET)
 788                         sctp_v4_map_v6(addr);
 789         } else {
 790                 if (addr->sa.sa_family == AF_INET6 &&
 791                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 792                         sctp_v6_map_v4(addr);
 793         }
 794
 795         if (addr->sa.sa_family == AF_INET) {
 796                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 797                 return sizeof(struct sockaddr_in);
 798         }
 799         return sizeof(struct sockaddr_in6);
 800 }
 801
 802 /* Where did this skb come from?  */
 803 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 804 {
 805         return IP6CB(skb)->iif;
 806 }
 807
 808 /* Was this packet marked by Explicit Congestion Notification? */
 809 static int sctp_v6_is_ce(const struct sk_buff *skb)
 810 {
 811         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 812 }
 813
 814 /* Dump the v6 addr to the seq file. */
 815 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 816 {
 817         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 818 }
 819
 820 static void sctp_v6_ecn_capable(struct sock *sk)
 821 {
 822         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 823 }
 824
 825 /* Initialize a PF_INET msgname from a ulpevent. */
 826 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 827                                      char *msgname, int *addrlen)
 828 {
 829         union sctp_addr *addr;
 830         struct sctp_association *asoc;
 831         union sctp_addr *paddr;
 832
 833         if (!msgname)
 834                 return;
 835
 836         addr = (union sctp_addr *)msgname;
 837         asoc = event->asoc;
 838         paddr = &asoc->peer.primary_addr;
 839
 840         if (paddr->sa.sa_family == AF_INET) {
 841                 addr->v4.sin_family = AF_INET;
 842                 addr->v4.sin_port = htons(asoc->peer.port);
 843                 addr->v4.sin_addr = paddr->v4.sin_addr;
 844         } else {
 845                 addr->v6.sin6_family = AF_INET6;
 846                 addr->v6.sin6_flowinfo = 0;
 847                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 848                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 849                 else
 850                         addr->v6.sin6_scope_id = 0;
 851                 addr->v6.sin6_port = htons(asoc->peer.port);
 852                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 853         }
 854
 855         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 856 }
 857
 858 /* Initialize a msg_name from an inbound skb. */
 859 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 860                                    int *addr_len)
 861 {
 862         union sctp_addr *addr;
 863         struct sctphdr *sh;
 864
 865         if (!msgname)
 866                 return;
 867
 868         addr = (union sctp_addr *)msgname;
 869         sh = sctp_hdr(skb);
 870
 871         if (ip_hdr(skb)->version == 4) {
 872                 addr->v4.sin_family = AF_INET;
 873                 addr->v4.sin_port = sh->source;
 874                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 875         } else {
 876                 addr->v6.sin6_family = AF_INET6;
 877                 addr->v6.sin6_flowinfo = 0;
 878                 addr->v6.sin6_port = sh->source;
 879                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 880                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 881                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 882                 else
 883                         addr->v6.sin6_scope_id = 0;
 884         }
 885
 886         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 887 }
 888
 889 /* Do we support this AF? */
 890 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 891 {
 892         switch (family) {
 893         case AF_INET6:
 894                 return 1;
 895         /* v4-mapped-v6 addresses */
 896         case AF_INET:
 897                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 898                         return 1;
 899                 fallthrough;
 900         default:
 901                 return 0;
 902         }
 903 }
 904
 905 /* Address matching with wildcards allowed.  This extra level
 906  * of indirection lets us choose whether a PF_INET6 should
 907  * disallow any v4 addresses if we so choose.
 908  */
 909 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 910                                const union sctp_addr *addr2,
 911                                struct sctp_sock *opt)
 912 {
 913         struct sock *sk = sctp_opt2sk(opt);
 914         struct sctp_af *af1, *af2;
 915
 916         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 917         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 918
 919         if (!af1 || !af2)
 920                 return 0;
 921
 922         /* If the socket is IPv6 only, v4 addrs will not match */
 923         if (__ipv6_only_sock(sk) && af1 != af2)
 924                 return 0;
 925
 926         /* Today, wildcard AF_INET/AF_INET6. */
 927         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 928                 return 1;
 929
 930         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 931                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 932
 933         return __sctp_v6_cmp_addr(addr1, addr2);
 934 }
 935
 936 /* Verify that the provided sockaddr looks bindable.   Common verification,
 937  * has already been taken care of.
 938  */
 939 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 940 {
 941         struct sctp_af *af;
 942
 943         /* ASSERT: address family has already been verified. */
 944         if (addr->sa.sa_family != AF_INET6)
 945                 af = sctp_get_af_specific(addr->sa.sa_family);
 946         else {
 947                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 948                 struct net_device *dev;
 949
 950                 if (type & IPV6_ADDR_LINKLOCAL) {
 951                         struct net *net;
 952                         if (!addr->v6.sin6_scope_id)
 953                                 return 0;
 954                         net = sock_net(&opt->inet.sk);
 955                         rcu_read_lock();
 956                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 957                         if (!dev || !(opt->inet.freebind ||
 958                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 959                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 960                                                     dev, 0))) {
 961                                 rcu_read_unlock();
 962                                 return 0;
 963                         }
 964                         rcu_read_unlock();
 965                 }
 966
 967                 af = opt->pf->af;
 968         }
 969         return af->available(addr, opt);
 970 }
 971
 972 /* Verify that the provided sockaddr looks sendable.   Common verification,
 973  * has already been taken care of.
 974  */
 975 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 976 {
 977         struct sctp_af *af = NULL;
 978
 979         /* ASSERT: address family has already been verified. */
 980         if (addr->sa.sa_family != AF_INET6)
 981                 af = sctp_get_af_specific(addr->sa.sa_family);
 982         else {
 983                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 984                 struct net_device *dev;
 985
 986                 if (type & IPV6_ADDR_LINKLOCAL) {
 987                         if (!addr->v6.sin6_scope_id)
 988                                 return 0;
 989                         rcu_read_lock();
 990                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 991                                                    addr->v6.sin6_scope_id);
 992                         rcu_read_unlock();
 993                         if (!dev)
 994                                 return 0;
 995                 }
 996                 af = opt->pf->af;
 997         }
 998
 999         return af != NULL;
1000 }
1001
1002 /* Fill in Supported Address Type information for INIT and INIT-ACK
1003  * chunks.   Note: In the future, we may want to look at sock options
1004  * to determine whether a PF_INET6 socket really wants to have IPV4
1005  * addresses.
1006  * Returns number of addresses supported.
1007  */
1008 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
1009                                       __be16 *types)
1010 {
1011         types[0] = SCTP_PARAM_IPV6_ADDRESS;
1012         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1013                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
1014                 return 2;
1015         }
1016         return 1;
1017 }
1018
1019 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1020 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1021                         int peer)
1022 {
1023         int rc;
1024
1025         rc = inet6_getname(sock, uaddr, peer);
1026
1027         if (rc < 0)
1028                 return rc;
1029
1030         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1031                                           (union sctp_addr *)uaddr);
1032
1033         return rc;
1034 }
1035
1036 static const struct proto_ops inet6_seqpacket_ops = {
1037         .family            = PF_INET6,
1038         .owner             = THIS_MODULE,
1039         .release           = inet6_release,
1040         .bind              = inet6_bind,
1041         .connect           = sctp_inet_connect,
1042         .socketpair        = sock_no_socketpair,
1043         .accept            = inet_accept,
1044         .getname           = sctp_getname,
1045         .poll              = sctp_poll,
1046         .ioctl             = inet6_ioctl,
1047         .gettstamp         = sock_gettstamp,
1048         .listen            = sctp_inet_listen,
1049         .shutdown          = inet_shutdown,
1050         .setsockopt        = sock_common_setsockopt,
1051         .getsockopt        = sock_common_getsockopt,
1052         .sendmsg           = inet_sendmsg,
1053         .recvmsg           = inet_recvmsg,
1054         .mmap              = sock_no_mmap,
1055 #ifdef CONFIG_COMPAT
1056         .compat_ioctl      = inet6_compat_ioctl,
1057 #endif
1058 };
1059
1060 static struct inet_protosw sctpv6_seqpacket_protosw = {
1061         .type          = SOCK_SEQPACKET,
1062         .protocol      = IPPROTO_SCTP,
1063         .prot          = &sctpv6_prot,
1064         .ops           = &inet6_seqpacket_ops,
1065         .flags         = SCTP_PROTOSW_FLAG
1066 };
1067 static struct inet_protosw sctpv6_stream_protosw = {
1068         .type          = SOCK_STREAM,
1069         .protocol      = IPPROTO_SCTP,
1070         .prot          = &sctpv6_prot,
1071         .ops           = &inet6_seqpacket_ops,
1072         .flags         = SCTP_PROTOSW_FLAG,
1073 };
1074
1075 static int sctp6_rcv(struct sk_buff *skb)
1076 {
1077         SCTP_INPUT_CB(skb)->encap_port = 0;
1078         return sctp_rcv(skb) ? -1 : 0;
1079 }
1080
1081 static const struct inet6_protocol sctpv6_protocol = {
1082         .handler      = sctp6_rcv,
1083         .err_handler  = sctp_v6_err,
1084         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1085 };
1086
1087 static struct sctp_af sctp_af_inet6 = {
1088         .sa_family         = AF_INET6,
1089         .sctp_xmit         = sctp_v6_xmit,
1090         .setsockopt        = ipv6_setsockopt,
1091         .getsockopt        = ipv6_getsockopt,
1092         .get_dst           = sctp_v6_get_dst,
1093         .get_saddr         = sctp_v6_get_saddr,
1094         .copy_addrlist     = sctp_v6_copy_addrlist,
1095         .from_skb          = sctp_v6_from_skb,
1096         .from_sk           = sctp_v6_from_sk,
1097         .from_addr_param   = sctp_v6_from_addr_param,
1098         .to_addr_param     = sctp_v6_to_addr_param,
1099         .cmp_addr          = sctp_v6_cmp_addr,
1100         .scope             = sctp_v6_scope,
1101         .addr_valid        = sctp_v6_addr_valid,
1102         .inaddr_any        = sctp_v6_inaddr_any,
1103         .is_any            = sctp_v6_is_any,
1104         .available         = sctp_v6_available,
1105         .skb_iif           = sctp_v6_skb_iif,
1106         .is_ce             = sctp_v6_is_ce,
1107         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1108         .ecn_capable       = sctp_v6_ecn_capable,
1109         .net_header_len    = sizeof(struct ipv6hdr),
1110         .sockaddr_len      = sizeof(struct sockaddr_in6),
1111         .ip_options_len    = sctp_v6_ip_options_len,
1112 };
1113
1114 static struct sctp_pf sctp_pf_inet6 = {
1115         .event_msgname = sctp_inet6_event_msgname,
1116         .skb_msgname   = sctp_inet6_skb_msgname,
1117         .af_supported  = sctp_inet6_af_supported,
1118         .cmp_addr      = sctp_inet6_cmp_addr,
1119         .bind_verify   = sctp_inet6_bind_verify,
1120         .send_verify   = sctp_inet6_send_verify,
1121         .supported_addrs = sctp_inet6_supported_addrs,
1122         .create_accept_sk = sctp_v6_create_accept_sk,
1123         .addr_to_user  = sctp_v6_addr_to_user,
1124         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1125         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1126         .copy_ip_options = sctp_v6_copy_ip_options,
1127         .af            = &sctp_af_inet6,
1128 };
1129
1130 /* Initialize IPv6 support and register with socket layer.  */
1131 void sctp_v6_pf_init(void)
1132 {
1133         /* Register the SCTP specific PF_INET6 functions. */
1134         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1135
1136         /* Register the SCTP specific AF_INET6 functions. */
1137         sctp_register_af(&sctp_af_inet6);
1138 }
1139
1140 void sctp_v6_pf_exit(void)
1141 {
1142         list_del(&sctp_af_inet6.list);
1143 }
1144
1145 /* Initialize IPv6 support and register with socket layer.  */
1146 int sctp_v6_protosw_init(void)
1147 {
1148         int rc;
1149
1150         rc = proto_register(&sctpv6_prot, 1);
1151         if (rc)
1152                 return rc;
1153
1154         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1155         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1156         inet6_register_protosw(&sctpv6_stream_protosw);
1157
1158         return 0;
1159 }
1160
1161 void sctp_v6_protosw_exit(void)
1162 {
1163         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1164         inet6_unregister_protosw(&sctpv6_stream_protosw);
1165         proto_unregister(&sctpv6_prot);
1166 }
1167
1168
1169 /* Register with inet6 layer. */
1170 int sctp_v6_add_protocol(void)
1171 {
1172         /* Register notifier for inet6 address additions/deletions. */
1173         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1174
1175         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1176                 return -EAGAIN;
1177
1178         return 0;
1179 }
1180
1181 /* Unregister with inet6 layer. */
1182 void sctp_v6_del_protocol(void)
1183 {
1184         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1185         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1186 }