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 <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    Le Yanqun             <yanqun.le@nokia.com>
  33  *    Hui Huang             <hui.huang@nokia.com>
  34  *    La Monte H.P. Yarroll <piggy@acm.org>
  35  *    Sridhar Samudrala     <sri@us.ibm.com>
  36  *    Jon Grimm             <jgrimm@us.ibm.com>
  37  *    Ardelle Fan           <ardelle.fan@intel.com>
  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_flowinfo = 0;
 105                         addr->a.v6.sin6_addr = ifa->addr;
 106                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 107                         addr->valid = 1;
 108                         spin_lock_bh(&net->sctp.local_addr_lock);
 109                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 110                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 111                         spin_unlock_bh(&net->sctp.local_addr_lock);
 112                 }
 113                 break;
 114         case NETDEV_DOWN:
 115                 spin_lock_bh(&net->sctp.local_addr_lock);
 116                 list_for_each_entry_safe(addr, temp,
 117                                         &net->sctp.local_addr_list, list) {
 118                         if (addr->a.sa.sa_family == AF_INET6 &&
 119                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 120                                                 &ifa->addr)) {
 121                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 122                                 found = 1;
 123                                 addr->valid = 0;
 124                                 list_del_rcu(&addr->list);
 125                                 break;
 126                         }
 127                 }
 128                 spin_unlock_bh(&net->sctp.local_addr_lock);
 129                 if (found)
 130                         kfree_rcu(addr, rcu);
 131                 break;
 132         }
 133
 134         return NOTIFY_DONE;
 135 }
 136
 137 static struct notifier_block sctp_inet6addr_notifier = {
 138         .notifier_call = sctp_inet6addr_event,
 139 };
 140
 141 /* ICMP error handler. */
 142 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 143                         u8 type, u8 code, int offset, __be32 info)
 144 {
 145         struct inet6_dev *idev;
 146         struct sock *sk;
 147         struct sctp_association *asoc;
 148         struct sctp_transport *transport;
 149         struct ipv6_pinfo *np;
 150         __u16 saveip, savesctp;
 151         int err;
 152         struct net *net = dev_net(skb->dev);
 153
 154         idev = in6_dev_get(skb->dev);
 155
 156         /* Fix up skb to look at the embedded net header. */
 157         saveip   = skb->network_header;
 158         savesctp = skb->transport_header;
 159         skb_reset_network_header(skb);
 160         skb_set_transport_header(skb, offset);
 161         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 162         /* Put back, the original pointers. */
 163         skb->network_header   = saveip;
 164         skb->transport_header = savesctp;
 165         if (!sk) {
 166                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
 167                 goto out;
 168         }
 169
 170         /* Warning:  The sock lock is held.  Remember to call
 171          * sctp_err_finish!
 172          */
 173
 174         switch (type) {
 175         case ICMPV6_PKT_TOOBIG:
 176                 if (ip6_sk_accept_pmtu(sk))
 177                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 178                 goto out_unlock;
 179         case ICMPV6_PARAMPROB:
 180                 if (ICMPV6_UNK_NEXTHDR == code) {
 181                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 182                         goto out_unlock;
 183                 }
 184                 break;
 185         case NDISC_REDIRECT:
 186                 sctp_icmp_redirect(sk, transport, skb);
 187                 goto out_unlock;
 188         default:
 189                 break;
 190         }
 191
 192         np = inet6_sk(sk);
 193         icmpv6_err_convert(type, code, &err);
 194         if (!sock_owned_by_user(sk) && np->recverr) {
 195                 sk->sk_err = err;
 196                 sk->sk_error_report(sk);
 197         } else {  /* Only an error on timeout */
 198                 sk->sk_err_soft = err;
 199         }
 200
 201 out_unlock:
 202         sctp_err_finish(sk, transport);
 203 out:
 204         if (likely(idev != NULL))
 205                 in6_dev_put(idev);
 206 }
 207
 208 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 209 {
 210         struct sock *sk = skb->sk;
 211         struct ipv6_pinfo *np = inet6_sk(sk);
 212         struct flowi6 *fl6 = &transport->fl.u.ip6;
 213         __u8 tclass = np->tclass;
 214         int res;
 215
 216         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 217                  skb->len, &fl6->saddr, &fl6->daddr);
 218
 219         if (transport->dscp & SCTP_DSCP_SET_MASK)
 220                 tclass = transport->dscp & SCTP_DSCP_VAL_MASK;
 221
 222         if (INET_ECN_is_capable(tclass))
 223                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 224
 225         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 226                 skb->ignore_df = 1;
 227
 228         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 229
 230         rcu_read_lock();
 231         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
 232                        tclass);
 233         rcu_read_unlock();
 234         return res;
 235 }
 236
 237 /* Returns the dst cache entry for the given source and destination ip
 238  * addresses.
 239  */
 240 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 241                             struct flowi *fl, struct sock *sk)
 242 {
 243         struct sctp_association *asoc = t->asoc;
 244         struct dst_entry *dst = NULL;
 245         struct flowi6 *fl6 = &fl->u.ip6;
 246         struct sctp_bind_addr *bp;
 247         struct ipv6_pinfo *np = inet6_sk(sk);
 248         struct sctp_sockaddr_entry *laddr;
 249         union sctp_addr *daddr = &t->ipaddr;
 250         union sctp_addr dst_saddr;
 251         struct in6_addr *final_p, final;
 252         enum sctp_scope scope;
 253         __u8 matchlen = 0;
 254
 255         memset(fl6, 0, sizeof(struct flowi6));
 256         fl6->daddr = daddr->v6.sin6_addr;
 257         fl6->fl6_dport = daddr->v6.sin6_port;
 258         fl6->flowi6_proto = IPPROTO_SCTP;
 259         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 260                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 261         else if (asoc)
 262                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 263         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
 264                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 265
 266         if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
 267                 struct ip6_flowlabel *flowlabel;
 268
 269                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
 270                 if (!flowlabel)
 271                         goto out;
 272                 fl6_sock_release(flowlabel);
 273         }
 274
 275         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 276
 277         if (asoc)
 278                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 279
 280         if (saddr) {
 281                 fl6->saddr = saddr->v6.sin6_addr;
 282                 fl6->fl6_sport = saddr->v6.sin6_port;
 283
 284                 pr_debug("src=%pI6 - ", &fl6->saddr);
 285         }
 286
 287         rcu_read_lock();
 288         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 289         rcu_read_unlock();
 290
 291         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 292         if (!asoc || saddr)
 293                 goto out;
 294
 295         bp = &asoc->base.bind_addr;
 296         scope = sctp_scope(daddr);
 297         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 298          * to see if we can use it.
 299          */
 300         if (!IS_ERR(dst)) {
 301                 /* Walk through the bind address list and look for a bind
 302                  * address that matches the source address of the returned dst.
 303                  */
 304                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 305                 rcu_read_lock();
 306                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 307                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 308                             (laddr->state != SCTP_ADDR_SRC &&
 309                              !asoc->src_out_of_asoc_ok))
 310                                 continue;
 311
 312                         /* Do not compare against v4 addrs */
 313                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 314                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 315                                 rcu_read_unlock();
 316                                 goto out;
 317                         }
 318                 }
 319                 rcu_read_unlock();
 320                 /* None of the bound addresses match the source address of the
 321                  * dst. So release it.
 322                  */
 323                 dst_release(dst);
 324                 dst = NULL;
 325         }
 326
 327         /* Walk through the bind address list and try to get the
 328          * best source address for a given destination.
 329          */
 330         rcu_read_lock();
 331         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 332                 struct dst_entry *bdst;
 333                 __u8 bmatchlen;
 334
 335                 if (!laddr->valid ||
 336                     laddr->state != SCTP_ADDR_SRC ||
 337                     laddr->a.sa.sa_family != AF_INET6 ||
 338                     scope > sctp_scope(&laddr->a))
 339                         continue;
 340
 341                 fl6->saddr = laddr->a.v6.sin6_addr;
 342                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 343                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 344                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 345
 346                 if (IS_ERR(bdst))
 347                         continue;
 348
 349                 if (ipv6_chk_addr(dev_net(bdst->dev),
 350                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 351                         if (!IS_ERR_OR_NULL(dst))
 352                                 dst_release(dst);
 353                         dst = bdst;
 354                         break;
 355                 }
 356
 357                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 358                 if (matchlen > bmatchlen) {
 359                         dst_release(bdst);
 360                         continue;
 361                 }
 362
 363                 if (!IS_ERR_OR_NULL(dst))
 364                         dst_release(dst);
 365                 dst = bdst;
 366                 matchlen = bmatchlen;
 367         }
 368         rcu_read_unlock();
 369
 370 out:
 371         if (!IS_ERR_OR_NULL(dst)) {
 372                 struct rt6_info *rt;
 373
 374                 rt = (struct rt6_info *)dst;
 375                 t->dst = dst;
 376                 t->dst_cookie = rt6_get_cookie(rt);
 377                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 378                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 379                          &fl6->saddr);
 380         } else {
 381                 t->dst = NULL;
 382
 383                 pr_debug("no route\n");
 384         }
 385 }
 386
 387 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 388  * addresses.
 389  */
 390 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 391                                          union sctp_addr *s2)
 392 {
 393         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 394 }
 395
 396 /* Fills in the source address(saddr) based on the destination address(daddr)
 397  * and asoc's bind address list.
 398  */
 399 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 400                               struct sctp_transport *t,
 401                               struct flowi *fl)
 402 {
 403         struct flowi6 *fl6 = &fl->u.ip6;
 404         union sctp_addr *saddr = &t->saddr;
 405
 406         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 407
 408         if (t->dst) {
 409                 saddr->v6.sin6_family = AF_INET6;
 410                 saddr->v6.sin6_addr = fl6->saddr;
 411         }
 412 }
 413
 414 /* Make a copy of all potential local addresses. */
 415 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 416                                   struct net_device *dev)
 417 {
 418         struct inet6_dev *in6_dev;
 419         struct inet6_ifaddr *ifp;
 420         struct sctp_sockaddr_entry *addr;
 421
 422         rcu_read_lock();
 423         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 424                 rcu_read_unlock();
 425                 return;
 426         }
 427
 428         read_lock_bh(&in6_dev->lock);
 429         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 430                 /* Add the address to the local list.  */
 431                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 432                 if (addr) {
 433                         addr->a.v6.sin6_family = AF_INET6;
 434                         addr->a.v6.sin6_port = 0;
 435                         addr->a.v6.sin6_addr = ifp->addr;
 436                         addr->a.v6.sin6_scope_id = dev->ifindex;
 437                         addr->valid = 1;
 438                         INIT_LIST_HEAD(&addr->list);
 439                         list_add_tail(&addr->list, addrlist);
 440                 }
 441         }
 442
 443         read_unlock_bh(&in6_dev->lock);
 444         rcu_read_unlock();
 445 }
 446
 447 /* Copy over any ip options */
 448 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
 449 {
 450         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 451         struct ipv6_txoptions *opt;
 452
 453         newnp = inet6_sk(newsk);
 454
 455         rcu_read_lock();
 456         opt = rcu_dereference(np->opt);
 457         if (opt) {
 458                 opt = ipv6_dup_options(newsk, opt);
 459                 if (!opt)
 460                         pr_err("%s: Failed to copy ip options\n", __func__);
 461         }
 462         RCU_INIT_POINTER(newnp->opt, opt);
 463         rcu_read_unlock();
 464 }
 465
 466 /* Account for the IP options */
 467 static int sctp_v6_ip_options_len(struct sock *sk)
 468 {
 469         struct ipv6_pinfo *np = inet6_sk(sk);
 470         struct ipv6_txoptions *opt;
 471         int len = 0;
 472
 473         rcu_read_lock();
 474         opt = rcu_dereference(np->opt);
 475         if (opt)
 476                 len = opt->opt_flen + opt->opt_nflen;
 477
 478         rcu_read_unlock();
 479         return len;
 480 }
 481
 482 /* Initialize a sockaddr_storage from in incoming skb. */
 483 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 484                              int is_saddr)
 485 {
 486         /* Always called on head skb, so this is safe */
 487         struct sctphdr *sh = sctp_hdr(skb);
 488         struct sockaddr_in6 *sa = &addr->v6;
 489
 490         addr->v6.sin6_family = AF_INET6;
 491         addr->v6.sin6_flowinfo = 0; /* FIXME */
 492         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 493
 494         if (is_saddr) {
 495                 sa->sin6_port = sh->source;
 496                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 497         } else {
 498                 sa->sin6_port = sh->dest;
 499                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 500         }
 501 }
 502
 503 /* Initialize an sctp_addr from a socket. */
 504 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 505 {
 506         addr->v6.sin6_family = AF_INET6;
 507         addr->v6.sin6_port = 0;
 508         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 509 }
 510
 511 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 512 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 513 {
 514         if (addr->sa.sa_family == AF_INET) {
 515                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 516                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 517                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 518                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 519                         addr->v4.sin_addr.s_addr;
 520         } else {
 521                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 522         }
 523 }
 524
 525 /* Initialize sk->sk_daddr from sctp_addr. */
 526 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 527 {
 528         if (addr->sa.sa_family == AF_INET) {
 529                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 530                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 531                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 532                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 533         } else {
 534                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 535         }
 536 }
 537
 538 /* Initialize a sctp_addr from an address parameter. */
 539 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 540                                     union sctp_addr_param *param,
 541                                     __be16 port, int iif)
 542 {
 543         addr->v6.sin6_family = AF_INET6;
 544         addr->v6.sin6_port = port;
 545         addr->v6.sin6_flowinfo = 0; /* BUG */
 546         addr->v6.sin6_addr = param->v6.addr;
 547         addr->v6.sin6_scope_id = iif;
 548 }
 549
 550 /* Initialize an address parameter from a sctp_addr and return the length
 551  * of the address parameter.
 552  */
 553 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 554                                  union sctp_addr_param *param)
 555 {
 556         int length = sizeof(struct sctp_ipv6addr_param);
 557
 558         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 559         param->v6.param_hdr.length = htons(length);
 560         param->v6.addr = addr->v6.sin6_addr;
 561
 562         return length;
 563 }
 564
 565 /* Initialize a sctp_addr from struct in6_addr. */
 566 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 567                               __be16 port)
 568 {
 569         addr->sa.sa_family = AF_INET6;
 570         addr->v6.sin6_port = port;
 571         addr->v6.sin6_flowinfo = 0;
 572         addr->v6.sin6_addr = *saddr;
 573         addr->v6.sin6_scope_id = 0;
 574 }
 575
 576 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 577                               const union sctp_addr *addr2)
 578 {
 579         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 580                 if (addr1->sa.sa_family == AF_INET &&
 581                     addr2->sa.sa_family == AF_INET6 &&
 582                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 583                     addr2->v6.sin6_addr.s6_addr32[3] ==
 584                     addr1->v4.sin_addr.s_addr)
 585                         return 1;
 586
 587                 if (addr2->sa.sa_family == AF_INET &&
 588                     addr1->sa.sa_family == AF_INET6 &&
 589                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 590                     addr1->v6.sin6_addr.s6_addr32[3] ==
 591                     addr2->v4.sin_addr.s_addr)
 592                         return 1;
 593
 594                 return 0;
 595         }
 596
 597         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 598                 return 0;
 599
 600         /* If this is a linklocal address, compare the scope_id. */
 601         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 602             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 603             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 604                 return 0;
 605
 606         return 1;
 607 }
 608
 609 /* Compare addresses exactly.
 610  * v4-mapped-v6 is also in consideration.
 611  */
 612 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 613                             const union sctp_addr *addr2)
 614 {
 615         return __sctp_v6_cmp_addr(addr1, addr2) &&
 616                addr1->v6.sin6_port == addr2->v6.sin6_port;
 617 }
 618
 619 /* Initialize addr struct to INADDR_ANY. */
 620 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 621 {
 622         memset(addr, 0x00, sizeof(union sctp_addr));
 623         addr->v6.sin6_family = AF_INET6;
 624         addr->v6.sin6_port = port;
 625 }
 626
 627 /* Is this a wildcard address? */
 628 static int sctp_v6_is_any(const union sctp_addr *addr)
 629 {
 630         return ipv6_addr_any(&addr->v6.sin6_addr);
 631 }
 632
 633 /* Should this be available for binding?   */
 634 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 635 {
 636         int type;
 637         struct net *net = sock_net(&sp->inet.sk);
 638         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 639
 640         type = ipv6_addr_type(in6);
 641         if (IPV6_ADDR_ANY == type)
 642                 return 1;
 643         if (type == IPV6_ADDR_MAPPED) {
 644                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 645                         return 0;
 646                 sctp_v6_map_v4(addr);
 647                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 648         }
 649         if (!(type & IPV6_ADDR_UNICAST))
 650                 return 0;
 651
 652         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 653                 ipv6_chk_addr(net, in6, NULL, 0);
 654 }
 655
 656 /* This function checks if the address is a valid address to be used for
 657  * SCTP.
 658  *
 659  * Output:
 660  * Return 0 - If the address is a non-unicast or an illegal address.
 661  * Return 1 - If the address is a unicast.
 662  */
 663 static int sctp_v6_addr_valid(union sctp_addr *addr,
 664                               struct sctp_sock *sp,
 665                               const struct sk_buff *skb)
 666 {
 667         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 668
 669         /* Support v4-mapped-v6 address. */
 670         if (ret == IPV6_ADDR_MAPPED) {
 671                 /* Note: This routine is used in input, so v4-mapped-v6
 672                  * are disallowed here when there is no sctp_sock.
 673                  */
 674                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 675                         return 0;
 676                 sctp_v6_map_v4(addr);
 677                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 678         }
 679
 680         /* Is this a non-unicast address */
 681         if (!(ret & IPV6_ADDR_UNICAST))
 682                 return 0;
 683
 684         return 1;
 685 }
 686
 687 /* What is the scope of 'addr'?  */
 688 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 689 {
 690         enum sctp_scope retval;
 691         int v6scope;
 692
 693         /* The IPv6 scope is really a set of bit fields.
 694          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 695          */
 696
 697         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 698         switch (v6scope) {
 699         case IFA_HOST:
 700                 retval = SCTP_SCOPE_LOOPBACK;
 701                 break;
 702         case IFA_LINK:
 703                 retval = SCTP_SCOPE_LINK;
 704                 break;
 705         case IFA_SITE:
 706                 retval = SCTP_SCOPE_PRIVATE;
 707                 break;
 708         default:
 709                 retval = SCTP_SCOPE_GLOBAL;
 710                 break;
 711         }
 712
 713         return retval;
 714 }
 715
 716 /* Create and initialize a new sk for the socket to be returned by accept(). */
 717 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 718                                              struct sctp_association *asoc,
 719                                              bool kern)
 720 {
 721         struct sock *newsk;
 722         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 723         struct sctp6_sock *newsctp6sk;
 724
 725         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 726         if (!newsk)
 727                 goto out;
 728
 729         sock_init_data(NULL, newsk);
 730
 731         sctp_copy_sock(newsk, sk, asoc);
 732         sock_reset_flag(sk, SOCK_ZAPPED);
 733
 734         newsctp6sk = (struct sctp6_sock *)newsk;
 735         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 736
 737         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 738
 739         newnp = inet6_sk(newsk);
 740
 741         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 742         newnp->ipv6_mc_list = NULL;
 743         newnp->ipv6_ac_list = NULL;
 744         newnp->ipv6_fl_list = NULL;
 745
 746         sctp_v6_copy_ip_options(sk, newsk);
 747
 748         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 749          * and getpeername().
 750          */
 751         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 752
 753         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 754
 755         sk_refcnt_debug_inc(newsk);
 756
 757         if (newsk->sk_prot->init(newsk)) {
 758                 sk_common_release(newsk);
 759                 newsk = NULL;
 760         }
 761
 762 out:
 763         return newsk;
 764 }
 765
 766 /* Format a sockaddr for return to user space. This makes sure the return is
 767  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 768  */
 769 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 770 {
 771         if (sp->v4mapped) {
 772                 if (addr->sa.sa_family == AF_INET)
 773                         sctp_v4_map_v6(addr);
 774         } else {
 775                 if (addr->sa.sa_family == AF_INET6 &&
 776                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 777                         sctp_v6_map_v4(addr);
 778         }
 779
 780         if (addr->sa.sa_family == AF_INET) {
 781                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 782                 return sizeof(struct sockaddr_in);
 783         }
 784         return sizeof(struct sockaddr_in6);
 785 }
 786
 787 /* Where did this skb come from?  */
 788 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 789 {
 790         return IP6CB(skb)->iif;
 791 }
 792
 793 /* Was this packet marked by Explicit Congestion Notification? */
 794 static int sctp_v6_is_ce(const struct sk_buff *skb)
 795 {
 796         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 797 }
 798
 799 /* Dump the v6 addr to the seq file. */
 800 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 801 {
 802         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 803 }
 804
 805 static void sctp_v6_ecn_capable(struct sock *sk)
 806 {
 807         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 808 }
 809
 810 /* Initialize a PF_INET msgname from a ulpevent. */
 811 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 812                                      char *msgname, int *addrlen)
 813 {
 814         union sctp_addr *addr;
 815         struct sctp_association *asoc;
 816         union sctp_addr *paddr;
 817
 818         if (!msgname)
 819                 return;
 820
 821         addr = (union sctp_addr *)msgname;
 822         asoc = event->asoc;
 823         paddr = &asoc->peer.primary_addr;
 824
 825         if (paddr->sa.sa_family == AF_INET) {
 826                 addr->v4.sin_family = AF_INET;
 827                 addr->v4.sin_port = htons(asoc->peer.port);
 828                 addr->v4.sin_addr = paddr->v4.sin_addr;
 829         } else {
 830                 addr->v6.sin6_family = AF_INET6;
 831                 addr->v6.sin6_flowinfo = 0;
 832                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 833                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 834                 else
 835                         addr->v6.sin6_scope_id = 0;
 836                 addr->v6.sin6_port = htons(asoc->peer.port);
 837                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 838         }
 839
 840         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 841 }
 842
 843 /* Initialize a msg_name from an inbound skb. */
 844 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 845                                    int *addr_len)
 846 {
 847         union sctp_addr *addr;
 848         struct sctphdr *sh;
 849
 850         if (!msgname)
 851                 return;
 852
 853         addr = (union sctp_addr *)msgname;
 854         sh = sctp_hdr(skb);
 855
 856         if (ip_hdr(skb)->version == 4) {
 857                 addr->v4.sin_family = AF_INET;
 858                 addr->v4.sin_port = sh->source;
 859                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 860         } else {
 861                 addr->v6.sin6_family = AF_INET6;
 862                 addr->v6.sin6_flowinfo = 0;
 863                 addr->v6.sin6_port = sh->source;
 864                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 865                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 866                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 867                 else
 868                         addr->v6.sin6_scope_id = 0;
 869         }
 870
 871         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 872 }
 873
 874 /* Do we support this AF? */
 875 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 876 {
 877         switch (family) {
 878         case AF_INET6:
 879                 return 1;
 880         /* v4-mapped-v6 addresses */
 881         case AF_INET:
 882                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 883                         return 1;
 884                 /* fallthru */
 885         default:
 886                 return 0;
 887         }
 888 }
 889
 890 /* Address matching with wildcards allowed.  This extra level
 891  * of indirection lets us choose whether a PF_INET6 should
 892  * disallow any v4 addresses if we so choose.
 893  */
 894 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 895                                const union sctp_addr *addr2,
 896                                struct sctp_sock *opt)
 897 {
 898         struct sock *sk = sctp_opt2sk(opt);
 899         struct sctp_af *af1, *af2;
 900
 901         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 902         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 903
 904         if (!af1 || !af2)
 905                 return 0;
 906
 907         /* If the socket is IPv6 only, v4 addrs will not match */
 908         if (__ipv6_only_sock(sk) && af1 != af2)
 909                 return 0;
 910
 911         /* Today, wildcard AF_INET/AF_INET6. */
 912         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 913                 return 1;
 914
 915         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 916                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 917
 918         return __sctp_v6_cmp_addr(addr1, addr2);
 919 }
 920
 921 /* Verify that the provided sockaddr looks bindable.   Common verification,
 922  * has already been taken care of.
 923  */
 924 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 925 {
 926         struct sctp_af *af;
 927
 928         /* ASSERT: address family has already been verified. */
 929         if (addr->sa.sa_family != AF_INET6)
 930                 af = sctp_get_af_specific(addr->sa.sa_family);
 931         else {
 932                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 933                 struct net_device *dev;
 934
 935                 if (type & IPV6_ADDR_LINKLOCAL) {
 936                         struct net *net;
 937                         if (!addr->v6.sin6_scope_id)
 938                                 return 0;
 939                         net = sock_net(&opt->inet.sk);
 940                         rcu_read_lock();
 941                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 942                         if (!dev || !(opt->inet.freebind ||
 943                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 944                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 945                                                     dev, 0))) {
 946                                 rcu_read_unlock();
 947                                 return 0;
 948                         }
 949                         rcu_read_unlock();
 950                 }
 951
 952                 af = opt->pf->af;
 953         }
 954         return af->available(addr, opt);
 955 }
 956
 957 /* Verify that the provided sockaddr looks sendable.   Common verification,
 958  * has already been taken care of.
 959  */
 960 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 961 {
 962         struct sctp_af *af = NULL;
 963
 964         /* ASSERT: address family has already been verified. */
 965         if (addr->sa.sa_family != AF_INET6)
 966                 af = sctp_get_af_specific(addr->sa.sa_family);
 967         else {
 968                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 969                 struct net_device *dev;
 970
 971                 if (type & IPV6_ADDR_LINKLOCAL) {
 972                         if (!addr->v6.sin6_scope_id)
 973                                 return 0;
 974                         rcu_read_lock();
 975                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 976                                                    addr->v6.sin6_scope_id);
 977                         rcu_read_unlock();
 978                         if (!dev)
 979                                 return 0;
 980                 }
 981                 af = opt->pf->af;
 982         }
 983
 984         return af != NULL;
 985 }
 986
 987 /* Fill in Supported Address Type information for INIT and INIT-ACK
 988  * chunks.   Note: In the future, we may want to look at sock options
 989  * to determine whether a PF_INET6 socket really wants to have IPV4
 990  * addresses.
 991  * Returns number of addresses supported.
 992  */
 993 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 994                                       __be16 *types)
 995 {
 996         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 997         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 998                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 999                 return 2;
1000         }
1001         return 1;
1002 }
1003
1004 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1005 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1006                         int peer)
1007 {
1008         int rc;
1009
1010         rc = inet6_getname(sock, uaddr, peer);
1011
1012         if (rc < 0)
1013                 return rc;
1014
1015         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1016                                           (union sctp_addr *)uaddr);
1017
1018         return rc;
1019 }
1020
1021 static const struct proto_ops inet6_seqpacket_ops = {
1022         .family            = PF_INET6,
1023         .owner             = THIS_MODULE,
1024         .release           = inet6_release,
1025         .bind              = inet6_bind,
1026         .connect           = sctp_inet_connect,
1027         .socketpair        = sock_no_socketpair,
1028         .accept            = inet_accept,
1029         .getname           = sctp_getname,
1030         .poll              = sctp_poll,
1031         .ioctl             = inet6_ioctl,
1032         .listen            = sctp_inet_listen,
1033         .shutdown          = inet_shutdown,
1034         .setsockopt        = sock_common_setsockopt,
1035         .getsockopt        = sock_common_getsockopt,
1036         .sendmsg           = inet_sendmsg,
1037         .recvmsg           = inet_recvmsg,
1038         .mmap              = sock_no_mmap,
1039 #ifdef CONFIG_COMPAT
1040         .compat_setsockopt = compat_sock_common_setsockopt,
1041         .compat_getsockopt = compat_sock_common_getsockopt,
1042 #endif
1043 };
1044
1045 static struct inet_protosw sctpv6_seqpacket_protosw = {
1046         .type          = SOCK_SEQPACKET,
1047         .protocol      = IPPROTO_SCTP,
1048         .prot          = &sctpv6_prot,
1049         .ops           = &inet6_seqpacket_ops,
1050         .flags         = SCTP_PROTOSW_FLAG
1051 };
1052 static struct inet_protosw sctpv6_stream_protosw = {
1053         .type          = SOCK_STREAM,
1054         .protocol      = IPPROTO_SCTP,
1055         .prot          = &sctpv6_prot,
1056         .ops           = &inet6_seqpacket_ops,
1057         .flags         = SCTP_PROTOSW_FLAG,
1058 };
1059
1060 static int sctp6_rcv(struct sk_buff *skb)
1061 {
1062         return sctp_rcv(skb) ? -1 : 0;
1063 }
1064
1065 static const struct inet6_protocol sctpv6_protocol = {
1066         .handler      = sctp6_rcv,
1067         .err_handler  = sctp_v6_err,
1068         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1069 };
1070
1071 static struct sctp_af sctp_af_inet6 = {
1072         .sa_family         = AF_INET6,
1073         .sctp_xmit         = sctp_v6_xmit,
1074         .setsockopt        = ipv6_setsockopt,
1075         .getsockopt        = ipv6_getsockopt,
1076         .get_dst           = sctp_v6_get_dst,
1077         .get_saddr         = sctp_v6_get_saddr,
1078         .copy_addrlist     = sctp_v6_copy_addrlist,
1079         .from_skb          = sctp_v6_from_skb,
1080         .from_sk           = sctp_v6_from_sk,
1081         .from_addr_param   = sctp_v6_from_addr_param,
1082         .to_addr_param     = sctp_v6_to_addr_param,
1083         .cmp_addr          = sctp_v6_cmp_addr,
1084         .scope             = sctp_v6_scope,
1085         .addr_valid        = sctp_v6_addr_valid,
1086         .inaddr_any        = sctp_v6_inaddr_any,
1087         .is_any            = sctp_v6_is_any,
1088         .available         = sctp_v6_available,
1089         .skb_iif           = sctp_v6_skb_iif,
1090         .is_ce             = sctp_v6_is_ce,
1091         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1092         .ecn_capable       = sctp_v6_ecn_capable,
1093         .net_header_len    = sizeof(struct ipv6hdr),
1094         .sockaddr_len      = sizeof(struct sockaddr_in6),
1095         .ip_options_len    = sctp_v6_ip_options_len,
1096 #ifdef CONFIG_COMPAT
1097         .compat_setsockopt = compat_ipv6_setsockopt,
1098         .compat_getsockopt = compat_ipv6_getsockopt,
1099 #endif
1100 };
1101
1102 static struct sctp_pf sctp_pf_inet6 = {
1103         .event_msgname = sctp_inet6_event_msgname,
1104         .skb_msgname   = sctp_inet6_skb_msgname,
1105         .af_supported  = sctp_inet6_af_supported,
1106         .cmp_addr      = sctp_inet6_cmp_addr,
1107         .bind_verify   = sctp_inet6_bind_verify,
1108         .send_verify   = sctp_inet6_send_verify,
1109         .supported_addrs = sctp_inet6_supported_addrs,
1110         .create_accept_sk = sctp_v6_create_accept_sk,
1111         .addr_to_user  = sctp_v6_addr_to_user,
1112         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1113         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1114         .copy_ip_options = sctp_v6_copy_ip_options,
1115         .af            = &sctp_af_inet6,
1116 };
1117
1118 /* Initialize IPv6 support and register with socket layer.  */
1119 void sctp_v6_pf_init(void)
1120 {
1121         /* Register the SCTP specific PF_INET6 functions. */
1122         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1123
1124         /* Register the SCTP specific AF_INET6 functions. */
1125         sctp_register_af(&sctp_af_inet6);
1126 }
1127
1128 void sctp_v6_pf_exit(void)
1129 {
1130         list_del(&sctp_af_inet6.list);
1131 }
1132
1133 /* Initialize IPv6 support and register with socket layer.  */
1134 int sctp_v6_protosw_init(void)
1135 {
1136         int rc;
1137
1138         rc = proto_register(&sctpv6_prot, 1);
1139         if (rc)
1140                 return rc;
1141
1142         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1143         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1144         inet6_register_protosw(&sctpv6_stream_protosw);
1145
1146         return 0;
1147 }
1148
1149 void sctp_v6_protosw_exit(void)
1150 {
1151         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1152         inet6_unregister_protosw(&sctpv6_stream_protosw);
1153         proto_unregister(&sctpv6_prot);
1154 }
1155
1156
1157 /* Register with inet6 layer. */
1158 int sctp_v6_add_protocol(void)
1159 {
1160         /* Register notifier for inet6 address additions/deletions. */
1161         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1162
1163         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1164                 return -EAGAIN;
1165
1166         return 0;
1167 }
1168
1169 /* Unregister with inet6 layer. */
1170 void sctp_v6_del_protocol(void)
1171 {
1172         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1173         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1174 }