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