net/sctp/ipv6.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2002, 2004
   3  * Copyright (c) 2001 Nokia, Inc.
   4  * Copyright (c) 2001 La Monte H.P. Yarroll
   5  * Copyright (c) 2002-2003 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * This SCTP implementation is free software;
  12  * you can redistribute it and/or modify it under the terms of
  13  * the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This SCTP implementation is distributed in the hope that it
  18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19  *                 ************************
  20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21  * See the GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with GNU CC; see the file COPYING.  If not, see
  25  * <http://www.gnu.org/licenses/>.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <[email protected]>
  30  *
  31  * Written or modified by:
  32  *    Le Yanqun             <[email protected]>
  33  *    Hui Huang             <[email protected]>
  34  *    La Monte H.P. Yarroll <[email protected]>
  35  *    Sridhar Samudrala     <[email protected]>
  36  *    Jon Grimm             <[email protected]>
  37  *    Ardelle Fan           <[email protected]>
  38  *
  39  * Based on:
  40  *      linux/net/ipv6/tcp_ipv6.c
  41  */
  42
  43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  44
  45 #include <linux/module.h>
  46 #include <linux/errno.h>
  47 #include <linux/types.h>
  48 #include <linux/socket.h>
  49 #include <linux/sockios.h>
  50 #include <linux/net.h>
  51 #include <linux/in.h>
  52 #include <linux/in6.h>
  53 #include <linux/netdevice.h>
  54 #include <linux/init.h>
  55 #include <linux/ipsec.h>
  56 #include <linux/slab.h>
  57
  58 #include <linux/ipv6.h>
  59 #include <linux/icmpv6.h>
  60 #include <linux/random.h>
  61 #include <linux/seq_file.h>
  62
  63 #include <net/protocol.h>
  64 #include <net/ndisc.h>
  65 #include <net/ip.h>
  66 #include <net/ipv6.h>
  67 #include <net/transp_v6.h>
  68 #include <net/addrconf.h>
  69 #include <net/ip6_route.h>
  70 #include <net/inet_common.h>
  71 #include <net/inet_ecn.h>
  72 #include <net/sctp/sctp.h>
  73
  74 #include <linux/uaccess.h>
  75
  76 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  77                                          union sctp_addr *s2);
  78 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  79                               __be16 port);
  80 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  81                             const union sctp_addr *addr2);
  82
  83 /* Event handler for inet6 address addition/deletion events.
  84  * The sctp_local_addr_list needs to be protocted by a spin lock since
  85  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  86  * time and thus corrupt the list.
  87  * The reader side is protected with RCU.
  88  */
  89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  90                                 void *ptr)
  91 {
  92         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  93         struct sctp_sockaddr_entry *addr = NULL;
  94         struct sctp_sockaddr_entry *temp;
  95         struct net *net = dev_net(ifa->idev->dev);
  96         int found = 0;
  97
  98         switch (ev) {
  99         case NETDEV_UP:
 100                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 101                 if (addr) {
 102                         addr->a.v6.sin6_family = AF_INET6;
 103                         addr->a.v6.sin6_port = 0;
 104                         addr->a.v6.sin6_addr = ifa->addr;
 105                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 106                         addr->valid = 1;
 107                         spin_lock_bh(&net->sctp.local_addr_lock);
 108                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 109                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 110                         spin_unlock_bh(&net->sctp.local_addr_lock);
 111                 }
 112                 break;
 113         case NETDEV_DOWN:
 114                 spin_lock_bh(&net->sctp.local_addr_lock);
 115                 list_for_each_entry_safe(addr, temp,
 116                                         &net->sctp.local_addr_list, list) {
 117                         if (addr->a.sa.sa_family == AF_INET6 &&
 118                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 119                                                 &ifa->addr)) {
 120                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 121                                 found = 1;
 122                                 addr->valid = 0;
 123                                 list_del_rcu(&addr->list);
 124                                 break;
 125                         }
 126                 }
 127                 spin_unlock_bh(&net->sctp.local_addr_lock);
 128                 if (found)
 129                         kfree_rcu(addr, rcu);
 130                 break;
 131         }
 132
 133         return NOTIFY_DONE;
 134 }
 135
 136 static struct notifier_block sctp_inet6addr_notifier = {
 137         .notifier_call = sctp_inet6addr_event,
 138 };
 139
 140 /* ICMP error handler. */
 141 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 142                         u8 type, u8 code, int offset, __be32 info)
 143 {
 144         struct inet6_dev *idev;
 145         struct sock *sk;
 146         struct sctp_association *asoc;
 147         struct sctp_transport *transport;
 148         struct ipv6_pinfo *np;
 149         __u16 saveip, savesctp;
 150         int err;
 151         struct net *net = dev_net(skb->dev);
 152
 153         idev = in6_dev_get(skb->dev);
 154
 155         /* Fix up skb to look at the embedded net header. */
 156         saveip   = skb->network_header;
 157         savesctp = skb->transport_header;
 158         skb_reset_network_header(skb);
 159         skb_set_transport_header(skb, offset);
 160         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 161         /* Put back, the original pointers. */
 162         skb->network_header   = saveip;
 163         skb->transport_header = savesctp;
 164         if (!sk) {
 165                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
 166                 goto out;
 167         }
 168
 169         /* Warning:  The sock lock is held.  Remember to call
 170          * sctp_err_finish!
 171          */
 172
 173         switch (type) {
 174         case ICMPV6_PKT_TOOBIG:
 175                 if (ip6_sk_accept_pmtu(sk))
 176                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 177                 goto out_unlock;
 178         case ICMPV6_PARAMPROB:
 179                 if (ICMPV6_UNK_NEXTHDR == code) {
 180                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 181                         goto out_unlock;
 182                 }
 183                 break;
 184         case NDISC_REDIRECT:
 185                 sctp_icmp_redirect(sk, transport, skb);
 186                 goto out_unlock;
 187         default:
 188                 break;
 189         }
 190
 191         np = inet6_sk(sk);
 192         icmpv6_err_convert(type, code, &err);
 193         if (!sock_owned_by_user(sk) && np->recverr) {
 194                 sk->sk_err = err;
 195                 sk->sk_error_report(sk);
 196         } else {  /* Only an error on timeout */
 197                 sk->sk_err_soft = err;
 198         }
 199
 200 out_unlock:
 201         sctp_err_finish(sk, transport);
 202 out:
 203         if (likely(idev != NULL))
 204                 in6_dev_put(idev);
 205 }
 206
 207 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 208 {
 209         struct sock *sk = skb->sk;
 210         struct ipv6_pinfo *np = inet6_sk(sk);
 211         struct flowi6 *fl6 = &transport->fl.u.ip6;
 212         int res;
 213
 214         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 215                  skb->len, &fl6->saddr, &fl6->daddr);
 216
 217         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 218
 219         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 220                 skb->ignore_df = 1;
 221
 222         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 223
 224         rcu_read_lock();
 225         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
 226                        np->tclass);
 227         rcu_read_unlock();
 228         return res;
 229 }
 230
 231 /* Returns the dst cache entry for the given source and destination ip
 232  * addresses.
 233  */
 234 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 235                             struct flowi *fl, struct sock *sk)
 236 {
 237         struct sctp_association *asoc = t->asoc;
 238         struct dst_entry *dst = NULL;
 239         struct flowi6 *fl6 = &fl->u.ip6;
 240         struct sctp_bind_addr *bp;
 241         struct ipv6_pinfo *np = inet6_sk(sk);
 242         struct sctp_sockaddr_entry *laddr;
 243         union sctp_addr *daddr = &t->ipaddr;
 244         union sctp_addr dst_saddr;
 245         struct in6_addr *final_p, final;
 246         enum sctp_scope scope;
 247         __u8 matchlen = 0;
 248
 249         memset(fl6, 0, sizeof(struct flowi6));
 250         fl6->daddr = daddr->v6.sin6_addr;
 251         fl6->fl6_dport = daddr->v6.sin6_port;
 252         fl6->flowi6_proto = IPPROTO_SCTP;
 253         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 254                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 255         else if (asoc)
 256                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 257
 258         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 259
 260         if (asoc)
 261                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 262
 263         if (saddr) {
 264                 fl6->saddr = saddr->v6.sin6_addr;
 265                 fl6->fl6_sport = saddr->v6.sin6_port;
 266
 267                 pr_debug("src=%pI6 - ", &fl6->saddr);
 268         }
 269
 270         rcu_read_lock();
 271         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 272         rcu_read_unlock();
 273
 274         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 275         if (!asoc || saddr)
 276                 goto out;
 277
 278         bp = &asoc->base.bind_addr;
 279         scope = sctp_scope(daddr);
 280         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 281          * to see if we can use it.
 282          */
 283         if (!IS_ERR(dst)) {
 284                 /* Walk through the bind address list and look for a bind
 285                  * address that matches the source address of the returned dst.
 286                  */
 287                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 288                 rcu_read_lock();
 289                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 290                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 291                             (laddr->state != SCTP_ADDR_SRC &&
 292                              !asoc->src_out_of_asoc_ok))
 293                                 continue;
 294
 295                         /* Do not compare against v4 addrs */
 296                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 297                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 298                                 rcu_read_unlock();
 299                                 goto out;
 300                         }
 301                 }
 302                 rcu_read_unlock();
 303                 /* None of the bound addresses match the source address of the
 304                  * dst. So release it.
 305                  */
 306                 dst_release(dst);
 307                 dst = NULL;
 308         }
 309
 310         /* Walk through the bind address list and try to get the
 311          * best source address for a given destination.
 312          */
 313         rcu_read_lock();
 314         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 315                 struct dst_entry *bdst;
 316                 __u8 bmatchlen;
 317
 318                 if (!laddr->valid ||
 319                     laddr->state != SCTP_ADDR_SRC ||
 320                     laddr->a.sa.sa_family != AF_INET6 ||
 321                     scope > sctp_scope(&laddr->a))
 322                         continue;
 323
 324                 fl6->saddr = laddr->a.v6.sin6_addr;
 325                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 326                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 327                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 328
 329                 if (IS_ERR(bdst))
 330                         continue;
 331
 332                 if (ipv6_chk_addr(dev_net(bdst->dev),
 333                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 334                         if (!IS_ERR_OR_NULL(dst))
 335                                 dst_release(dst);
 336                         dst = bdst;
 337                         break;
 338                 }
 339
 340                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 341                 if (matchlen > bmatchlen) {
 342                         dst_release(bdst);
 343                         continue;
 344                 }
 345
 346                 if (!IS_ERR_OR_NULL(dst))
 347                         dst_release(dst);
 348                 dst = bdst;
 349                 matchlen = bmatchlen;
 350         }
 351         rcu_read_unlock();
 352
 353 out:
 354         if (!IS_ERR_OR_NULL(dst)) {
 355                 struct rt6_info *rt;
 356
 357                 rt = (struct rt6_info *)dst;
 358                 t->dst = dst;
 359                 t->dst_cookie = rt6_get_cookie(rt);
 360                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 361                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 362                          &fl6->saddr);
 363         } else {
 364                 t->dst = NULL;
 365
 366                 pr_debug("no route\n");
 367         }
 368 }
 369
 370 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 371  * addresses.
 372  */
 373 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 374                                          union sctp_addr *s2)
 375 {
 376         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 377 }
 378
 379 /* Fills in the source address(saddr) based on the destination address(daddr)
 380  * and asoc's bind address list.
 381  */
 382 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 383                               struct sctp_transport *t,
 384                               struct flowi *fl)
 385 {
 386         struct flowi6 *fl6 = &fl->u.ip6;
 387         union sctp_addr *saddr = &t->saddr;
 388
 389         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 390
 391         if (t->dst) {
 392                 saddr->v6.sin6_family = AF_INET6;
 393                 saddr->v6.sin6_addr = fl6->saddr;
 394         }
 395 }
 396
 397 /* Make a copy of all potential local addresses. */
 398 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 399                                   struct net_device *dev)
 400 {
 401         struct inet6_dev *in6_dev;
 402         struct inet6_ifaddr *ifp;
 403         struct sctp_sockaddr_entry *addr;
 404
 405         rcu_read_lock();
 406         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 407                 rcu_read_unlock();
 408                 return;
 409         }
 410
 411         read_lock_bh(&in6_dev->lock);
 412         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 413                 /* Add the address to the local list.  */
 414                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 415                 if (addr) {
 416                         addr->a.v6.sin6_family = AF_INET6;
 417                         addr->a.v6.sin6_port = 0;
 418                         addr->a.v6.sin6_addr = ifp->addr;
 419                         addr->a.v6.sin6_scope_id = dev->ifindex;
 420                         addr->valid = 1;
 421                         INIT_LIST_HEAD(&addr->list);
 422                         list_add_tail(&addr->list, addrlist);
 423                 }
 424         }
 425
 426         read_unlock_bh(&in6_dev->lock);
 427         rcu_read_unlock();
 428 }
 429
 430 /* Copy over any ip options */
 431 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
 432 {
 433         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 434         struct ipv6_txoptions *opt;
 435
 436         newnp = inet6_sk(newsk);
 437
 438         rcu_read_lock();
 439         opt = rcu_dereference(np->opt);
 440         if (opt) {
 441                 opt = ipv6_dup_options(newsk, opt);
 442                 if (!opt)
 443                         pr_err("%s: Failed to copy ip options\n", __func__);
 444         }
 445         RCU_INIT_POINTER(newnp->opt, opt);
 446         rcu_read_unlock();
 447 }
 448
 449 /* Account for the IP options */
 450 static int sctp_v6_ip_options_len(struct sock *sk)
 451 {
 452         struct ipv6_pinfo *np = inet6_sk(sk);
 453         struct ipv6_txoptions *opt;
 454         int len = 0;
 455
 456         rcu_read_lock();
 457         opt = rcu_dereference(np->opt);
 458         if (opt)
 459                 len = opt->opt_flen + opt->opt_nflen;
 460
 461         rcu_read_unlock();
 462         return len;
 463 }
 464
 465 /* Initialize a sockaddr_storage from in incoming skb. */
 466 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 467                              int is_saddr)
 468 {
 469         /* Always called on head skb, so this is safe */
 470         struct sctphdr *sh = sctp_hdr(skb);
 471         struct sockaddr_in6 *sa = &addr->v6;
 472
 473         addr->v6.sin6_family = AF_INET6;
 474         addr->v6.sin6_flowinfo = 0; /* FIXME */
 475         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 476
 477         if (is_saddr) {
 478                 sa->sin6_port = sh->source;
 479                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 480         } else {
 481                 sa->sin6_port = sh->dest;
 482                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 483         }
 484 }
 485
 486 /* Initialize an sctp_addr from a socket. */
 487 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 488 {
 489         addr->v6.sin6_family = AF_INET6;
 490         addr->v6.sin6_port = 0;
 491         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 492 }
 493
 494 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 495 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 496 {
 497         if (addr->sa.sa_family == AF_INET) {
 498                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 499                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 500                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 501                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 502                         addr->v4.sin_addr.s_addr;
 503         } else {
 504                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 505         }
 506 }
 507
 508 /* Initialize sk->sk_daddr from sctp_addr. */
 509 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 510 {
 511         if (addr->sa.sa_family == AF_INET) {
 512                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 513                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 514                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 515                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 516         } else {
 517                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 518         }
 519 }
 520
 521 /* Initialize a sctp_addr from an address parameter. */
 522 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 523                                     union sctp_addr_param *param,
 524                                     __be16 port, int iif)
 525 {
 526         addr->v6.sin6_family = AF_INET6;
 527         addr->v6.sin6_port = port;
 528         addr->v6.sin6_flowinfo = 0; /* BUG */
 529         addr->v6.sin6_addr = param->v6.addr;
 530         addr->v6.sin6_scope_id = iif;
 531 }
 532
 533 /* Initialize an address parameter from a sctp_addr and return the length
 534  * of the address parameter.
 535  */
 536 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 537                                  union sctp_addr_param *param)
 538 {
 539         int length = sizeof(struct sctp_ipv6addr_param);
 540
 541         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 542         param->v6.param_hdr.length = htons(length);
 543         param->v6.addr = addr->v6.sin6_addr;
 544
 545         return length;
 546 }
 547
 548 /* Initialize a sctp_addr from struct in6_addr. */
 549 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 550                               __be16 port)
 551 {
 552         addr->sa.sa_family = AF_INET6;
 553         addr->v6.sin6_port = port;
 554         addr->v6.sin6_flowinfo = 0;
 555         addr->v6.sin6_addr = *saddr;
 556         addr->v6.sin6_scope_id = 0;
 557 }
 558
 559 /* Compare addresses exactly.
 560  * v4-mapped-v6 is also in consideration.
 561  */
 562 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 563                             const union sctp_addr *addr2)
 564 {
 565         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 566                 if (addr1->sa.sa_family == AF_INET &&
 567                     addr2->sa.sa_family == AF_INET6 &&
 568                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 569                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 570                             addr2->v6.sin6_addr.s6_addr32[3] ==
 571                             addr1->v4.sin_addr.s_addr)
 572                                 return 1;
 573                 }
 574                 if (addr2->sa.sa_family == AF_INET &&
 575                     addr1->sa.sa_family == AF_INET6 &&
 576                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 577                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 578                             addr1->v6.sin6_addr.s6_addr32[3] ==
 579                             addr2->v4.sin_addr.s_addr)
 580                                 return 1;
 581                 }
 582                 return 0;
 583         }
 584         if (addr1->v6.sin6_port != addr2->v6.sin6_port)
 585                 return 0;
 586         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 587                 return 0;
 588         /* If this is a linklocal address, compare the scope_id. */
 589         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 590                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 591                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 592                         return 0;
 593                 }
 594         }
 595
 596         return 1;
 597 }
 598
 599 /* Initialize addr struct to INADDR_ANY. */
 600 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 601 {
 602         memset(addr, 0x00, sizeof(union sctp_addr));
 603         addr->v6.sin6_family = AF_INET6;
 604         addr->v6.sin6_port = port;
 605 }
 606
 607 /* Is this a wildcard address? */
 608 static int sctp_v6_is_any(const union sctp_addr *addr)
 609 {
 610         return ipv6_addr_any(&addr->v6.sin6_addr);
 611 }
 612
 613 /* Should this be available for binding?   */
 614 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 615 {
 616         int type;
 617         struct net *net = sock_net(&sp->inet.sk);
 618         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 619
 620         type = ipv6_addr_type(in6);
 621         if (IPV6_ADDR_ANY == type)
 622                 return 1;
 623         if (type == IPV6_ADDR_MAPPED) {
 624                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 625                         return 0;
 626                 sctp_v6_map_v4(addr);
 627                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 628         }
 629         if (!(type & IPV6_ADDR_UNICAST))
 630                 return 0;
 631
 632         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 633                 ipv6_chk_addr(net, in6, NULL, 0);
 634 }
 635
 636 /* This function checks if the address is a valid address to be used for
 637  * SCTP.
 638  *
 639  * Output:
 640  * Return 0 - If the address is a non-unicast or an illegal address.
 641  * Return 1 - If the address is a unicast.
 642  */
 643 static int sctp_v6_addr_valid(union sctp_addr *addr,
 644                               struct sctp_sock *sp,
 645                               const struct sk_buff *skb)
 646 {
 647         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 648
 649         /* Support v4-mapped-v6 address. */
 650         if (ret == IPV6_ADDR_MAPPED) {
 651                 /* Note: This routine is used in input, so v4-mapped-v6
 652                  * are disallowed here when there is no sctp_sock.
 653                  */
 654                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 655                         return 0;
 656                 sctp_v6_map_v4(addr);
 657                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 658         }
 659
 660         /* Is this a non-unicast address */
 661         if (!(ret & IPV6_ADDR_UNICAST))
 662                 return 0;
 663
 664         return 1;
 665 }
 666
 667 /* What is the scope of 'addr'?  */
 668 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 669 {
 670         enum sctp_scope retval;
 671         int v6scope;
 672
 673         /* The IPv6 scope is really a set of bit fields.
 674          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 675          */
 676
 677         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 678         switch (v6scope) {
 679         case IFA_HOST:
 680                 retval = SCTP_SCOPE_LOOPBACK;
 681                 break;
 682         case IFA_LINK:
 683                 retval = SCTP_SCOPE_LINK;
 684                 break;
 685         case IFA_SITE:
 686                 retval = SCTP_SCOPE_PRIVATE;
 687                 break;
 688         default:
 689                 retval = SCTP_SCOPE_GLOBAL;
 690                 break;
 691         }
 692
 693         return retval;
 694 }
 695
 696 /* Create and initialize a new sk for the socket to be returned by accept(). */
 697 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 698                                              struct sctp_association *asoc,
 699                                              bool kern)
 700 {
 701         struct sock *newsk;
 702         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 703         struct sctp6_sock *newsctp6sk;
 704
 705         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 706         if (!newsk)
 707                 goto out;
 708
 709         sock_init_data(NULL, newsk);
 710
 711         sctp_copy_sock(newsk, sk, asoc);
 712         sock_reset_flag(sk, SOCK_ZAPPED);
 713
 714         newsctp6sk = (struct sctp6_sock *)newsk;
 715         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 716
 717         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 718
 719         newnp = inet6_sk(newsk);
 720
 721         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 722         newnp->ipv6_mc_list = NULL;
 723         newnp->ipv6_ac_list = NULL;
 724         newnp->ipv6_fl_list = NULL;
 725
 726         sctp_v6_copy_ip_options(sk, newsk);
 727
 728         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 729          * and getpeername().
 730          */
 731         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 732
 733         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 734
 735         sk_refcnt_debug_inc(newsk);
 736
 737         if (newsk->sk_prot->init(newsk)) {
 738                 sk_common_release(newsk);
 739                 newsk = NULL;
 740         }
 741
 742 out:
 743         return newsk;
 744 }
 745
 746 /* Format a sockaddr for return to user space. This makes sure the return is
 747  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 748  */
 749 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 750 {
 751         if (sp->v4mapped) {
 752                 if (addr->sa.sa_family == AF_INET)
 753                         sctp_v4_map_v6(addr);
 754         } else {
 755                 if (addr->sa.sa_family == AF_INET6 &&
 756                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 757                         sctp_v6_map_v4(addr);
 758         }
 759
 760         if (addr->sa.sa_family == AF_INET) {
 761                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 762                 return sizeof(struct sockaddr_in);
 763         }
 764         return sizeof(struct sockaddr_in6);
 765 }
 766
 767 /* Where did this skb come from?  */
 768 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 769 {
 770         return IP6CB(skb)->iif;
 771 }
 772
 773 /* Was this packet marked by Explicit Congestion Notification? */
 774 static int sctp_v6_is_ce(const struct sk_buff *skb)
 775 {
 776         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 777 }
 778
 779 /* Dump the v6 addr to the seq file. */
 780 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 781 {
 782         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 783 }
 784
 785 static void sctp_v6_ecn_capable(struct sock *sk)
 786 {
 787         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 788 }
 789
 790 /* Initialize a PF_INET msgname from a ulpevent. */
 791 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 792                                      char *msgname, int *addrlen)
 793 {
 794         union sctp_addr *addr;
 795         struct sctp_association *asoc;
 796         union sctp_addr *paddr;
 797
 798         if (!msgname)
 799                 return;
 800
 801         addr = (union sctp_addr *)msgname;
 802         asoc = event->asoc;
 803         paddr = &asoc->peer.primary_addr;
 804
 805         if (paddr->sa.sa_family == AF_INET) {
 806                 addr->v4.sin_family = AF_INET;
 807                 addr->v4.sin_port = htons(asoc->peer.port);
 808                 addr->v4.sin_addr = paddr->v4.sin_addr;
 809         } else {
 810                 addr->v6.sin6_family = AF_INET6;
 811                 addr->v6.sin6_flowinfo = 0;
 812                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 813                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 814                 else
 815                         addr->v6.sin6_scope_id = 0;
 816                 addr->v6.sin6_port = htons(asoc->peer.port);
 817                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 818         }
 819
 820         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 821 }
 822
 823 /* Initialize a msg_name from an inbound skb. */
 824 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 825                                    int *addr_len)
 826 {
 827         union sctp_addr *addr;
 828         struct sctphdr *sh;
 829
 830         if (!msgname)
 831                 return;
 832
 833         addr = (union sctp_addr *)msgname;
 834         sh = sctp_hdr(skb);
 835
 836         if (ip_hdr(skb)->version == 4) {
 837                 addr->v4.sin_family = AF_INET;
 838                 addr->v4.sin_port = sh->source;
 839                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 840         } else {
 841                 addr->v6.sin6_family = AF_INET6;
 842                 addr->v6.sin6_flowinfo = 0;
 843                 addr->v6.sin6_port = sh->source;
 844                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 845                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 846                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 847                 else
 848                         addr->v6.sin6_scope_id = 0;
 849         }
 850
 851         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 852 }
 853
 854 /* Do we support this AF? */
 855 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 856 {
 857         switch (family) {
 858         case AF_INET6:
 859                 return 1;
 860         /* v4-mapped-v6 addresses */
 861         case AF_INET:
 862                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 863                         return 1;
 864                 /* fallthru */
 865         default:
 866                 return 0;
 867         }
 868 }
 869
 870 /* Address matching with wildcards allowed.  This extra level
 871  * of indirection lets us choose whether a PF_INET6 should
 872  * disallow any v4 addresses if we so choose.
 873  */
 874 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 875                                const union sctp_addr *addr2,
 876                                struct sctp_sock *opt)
 877 {
 878         struct sctp_af *af1, *af2;
 879         struct sock *sk = sctp_opt2sk(opt);
 880
 881         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 882         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 883
 884         if (!af1 || !af2)
 885                 return 0;
 886
 887         /* If the socket is IPv6 only, v4 addrs will not match */
 888         if (__ipv6_only_sock(sk) && af1 != af2)
 889                 return 0;
 890
 891         /* Today, wildcard AF_INET/AF_INET6. */
 892         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 893                 return 1;
 894
 895         if (addr1->sa.sa_family != addr2->sa.sa_family)
 896                 return 0;
 897
 898         return af1->cmp_addr(addr1, addr2);
 899 }
 900
 901 /* Verify that the provided sockaddr looks bindable.   Common verification,
 902  * has already been taken care of.
 903  */
 904 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 905 {
 906         struct sctp_af *af;
 907
 908         /* ASSERT: address family has already been verified. */
 909         if (addr->sa.sa_family != AF_INET6)
 910                 af = sctp_get_af_specific(addr->sa.sa_family);
 911         else {
 912                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 913                 struct net_device *dev;
 914
 915                 if (type & IPV6_ADDR_LINKLOCAL) {
 916                         struct net *net;
 917                         if (!addr->v6.sin6_scope_id)
 918                                 return 0;
 919                         net = sock_net(&opt->inet.sk);
 920                         rcu_read_lock();
 921                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 922                         if (!dev || !(opt->inet.freebind ||
 923                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 924                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 925                                                     dev, 0))) {
 926                                 rcu_read_unlock();
 927                                 return 0;
 928                         }
 929                         rcu_read_unlock();
 930                 }
 931
 932                 af = opt->pf->af;
 933         }
 934         return af->available(addr, opt);
 935 }
 936
 937 /* Verify that the provided sockaddr looks sendable.   Common verification,
 938  * has already been taken care of.
 939  */
 940 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 941 {
 942         struct sctp_af *af = NULL;
 943
 944         /* ASSERT: address family has already been verified. */
 945         if (addr->sa.sa_family != AF_INET6)
 946                 af = sctp_get_af_specific(addr->sa.sa_family);
 947         else {
 948                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 949                 struct net_device *dev;
 950
 951                 if (type & IPV6_ADDR_LINKLOCAL) {
 952                         if (!addr->v6.sin6_scope_id)
 953                                 return 0;
 954                         rcu_read_lock();
 955                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 956                                                    addr->v6.sin6_scope_id);
 957                         rcu_read_unlock();
 958                         if (!dev)
 959                                 return 0;
 960                 }
 961                 af = opt->pf->af;
 962         }
 963
 964         return af != NULL;
 965 }
 966
 967 /* Fill in Supported Address Type information for INIT and INIT-ACK
 968  * chunks.   Note: In the future, we may want to look at sock options
 969  * to determine whether a PF_INET6 socket really wants to have IPV4
 970  * addresses.
 971  * Returns number of addresses supported.
 972  */
 973 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 974                                       __be16 *types)
 975 {
 976         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 977         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 978                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 979                 return 2;
 980         }
 981         return 1;
 982 }
 983
 984 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 985 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 986                         int peer)
 987 {
 988         int rc;
 989
 990         rc = inet6_getname(sock, uaddr, peer);
 991
 992         if (rc < 0)
 993                 return rc;
 994
 995         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 996                                           (union sctp_addr *)uaddr);
 997
 998         return rc;
 999 }
1000
1001 static const struct proto_ops inet6_seqpacket_ops = {
1002         .family            = PF_INET6,
1003         .owner             = THIS_MODULE,
1004         .release           = inet6_release,
1005         .bind              = inet6_bind,
1006         .connect           = inet_dgram_connect,
1007         .socketpair        = sock_no_socketpair,
1008         .accept            = inet_accept,
1009         .getname           = sctp_getname,
1010         .poll              = sctp_poll,
1011         .ioctl             = inet6_ioctl,
1012         .listen            = sctp_inet_listen,
1013         .shutdown          = inet_shutdown,
1014         .setsockopt        = sock_common_setsockopt,
1015         .getsockopt        = sock_common_getsockopt,
1016         .sendmsg           = inet_sendmsg,
1017         .recvmsg           = inet_recvmsg,
1018         .mmap              = sock_no_mmap,
1019 #ifdef CONFIG_COMPAT
1020         .compat_setsockopt = compat_sock_common_setsockopt,
1021         .compat_getsockopt = compat_sock_common_getsockopt,
1022 #endif
1023 };
1024
1025 static struct inet_protosw sctpv6_seqpacket_protosw = {
1026         .type          = SOCK_SEQPACKET,
1027         .protocol      = IPPROTO_SCTP,
1028         .prot          = &sctpv6_prot,
1029         .ops           = &inet6_seqpacket_ops,
1030         .flags         = SCTP_PROTOSW_FLAG
1031 };
1032 static struct inet_protosw sctpv6_stream_protosw = {
1033         .type          = SOCK_STREAM,
1034         .protocol      = IPPROTO_SCTP,
1035         .prot          = &sctpv6_prot,
1036         .ops           = &inet6_seqpacket_ops,
1037         .flags         = SCTP_PROTOSW_FLAG,
1038 };
1039
1040 static int sctp6_rcv(struct sk_buff *skb)
1041 {
1042         return sctp_rcv(skb) ? -1 : 0;
1043 }
1044
1045 static const struct inet6_protocol sctpv6_protocol = {
1046         .handler      = sctp6_rcv,
1047         .err_handler  = sctp_v6_err,
1048         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1049 };
1050
1051 static struct sctp_af sctp_af_inet6 = {
1052         .sa_family         = AF_INET6,
1053         .sctp_xmit         = sctp_v6_xmit,
1054         .setsockopt        = ipv6_setsockopt,
1055         .getsockopt        = ipv6_getsockopt,
1056         .get_dst           = sctp_v6_get_dst,
1057         .get_saddr         = sctp_v6_get_saddr,
1058         .copy_addrlist     = sctp_v6_copy_addrlist,
1059         .from_skb          = sctp_v6_from_skb,
1060         .from_sk           = sctp_v6_from_sk,
1061         .from_addr_param   = sctp_v6_from_addr_param,
1062         .to_addr_param     = sctp_v6_to_addr_param,
1063         .cmp_addr          = sctp_v6_cmp_addr,
1064         .scope             = sctp_v6_scope,
1065         .addr_valid        = sctp_v6_addr_valid,
1066         .inaddr_any        = sctp_v6_inaddr_any,
1067         .is_any            = sctp_v6_is_any,
1068         .available         = sctp_v6_available,
1069         .skb_iif           = sctp_v6_skb_iif,
1070         .is_ce             = sctp_v6_is_ce,
1071         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1072         .ecn_capable       = sctp_v6_ecn_capable,
1073         .net_header_len    = sizeof(struct ipv6hdr),
1074         .sockaddr_len      = sizeof(struct sockaddr_in6),
1075         .ip_options_len    = sctp_v6_ip_options_len,
1076 #ifdef CONFIG_COMPAT
1077         .compat_setsockopt = compat_ipv6_setsockopt,
1078         .compat_getsockopt = compat_ipv6_getsockopt,
1079 #endif
1080 };
1081
1082 static struct sctp_pf sctp_pf_inet6 = {
1083         .event_msgname = sctp_inet6_event_msgname,
1084         .skb_msgname   = sctp_inet6_skb_msgname,
1085         .af_supported  = sctp_inet6_af_supported,
1086         .cmp_addr      = sctp_inet6_cmp_addr,
1087         .bind_verify   = sctp_inet6_bind_verify,
1088         .send_verify   = sctp_inet6_send_verify,
1089         .supported_addrs = sctp_inet6_supported_addrs,
1090         .create_accept_sk = sctp_v6_create_accept_sk,
1091         .addr_to_user  = sctp_v6_addr_to_user,
1092         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1093         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1094         .copy_ip_options = sctp_v6_copy_ip_options,
1095         .af            = &sctp_af_inet6,
1096 };
1097
1098 /* Initialize IPv6 support and register with socket layer.  */
1099 void sctp_v6_pf_init(void)
1100 {
1101         /* Register the SCTP specific PF_INET6 functions. */
1102         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1103
1104         /* Register the SCTP specific AF_INET6 functions. */
1105         sctp_register_af(&sctp_af_inet6);
1106 }
1107
1108 void sctp_v6_pf_exit(void)
1109 {
1110         list_del(&sctp_af_inet6.list);
1111 }
1112
1113 /* Initialize IPv6 support and register with socket layer.  */
1114 int sctp_v6_protosw_init(void)
1115 {
1116         int rc;
1117
1118         rc = proto_register(&sctpv6_prot, 1);
1119         if (rc)
1120                 return rc;
1121
1122         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1123         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1124         inet6_register_protosw(&sctpv6_stream_protosw);
1125
1126         return 0;
1127 }
1128
1129 void sctp_v6_protosw_exit(void)
1130 {
1131         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1132         inet6_unregister_protosw(&sctpv6_stream_protosw);
1133         proto_unregister(&sctpv6_prot);
1134 }
1135
1136
1137 /* Register with inet6 layer. */
1138 int sctp_v6_add_protocol(void)
1139 {
1140         /* Register notifier for inet6 address additions/deletions. */
1141         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1142
1143         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1144                 return -EAGAIN;
1145
1146         return 0;
1147 }
1148
1149 /* Unregister with inet6 layer. */
1150 void sctp_v6_del_protocol(void)
1151 {
1152         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1153         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1154 }