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, write to
  25  * the Free Software Foundation, 59 Temple Place - Suite 330,
  26  * Boston, MA 02111-1307, USA.
  27  *
  28  * Please send any bug reports or fixes you make to the
  29  * email address(es):
  30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  31  *
  32  * Or submit a bug report through the following website:
  33  *    http://www.sf.net/projects/lksctp
  34  *
  35  * Written or modified by:
  36  *    Le Yanqun             <yanqun.le@nokia.com>
  37  *    Hui Huang             <hui.huang@nokia.com>
  38  *    La Monte H.P. Yarroll <piggy@acm.org>
  39  *    Sridhar Samudrala     <sri@us.ibm.com>
  40  *    Jon Grimm             <jgrimm@us.ibm.com>
  41  *    Ardelle Fan           <ardelle.fan@intel.com>
  42  *
  43  * Based on:
  44  *      linux/net/ipv6/tcp_ipv6.c
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  51
  52 #include <linux/module.h>
  53 #include <linux/errno.h>
  54 #include <linux/types.h>
  55 #include <linux/socket.h>
  56 #include <linux/sockios.h>
  57 #include <linux/net.h>
  58 #include <linux/in.h>
  59 #include <linux/in6.h>
  60 #include <linux/netdevice.h>
  61 #include <linux/init.h>
  62 #include <linux/ipsec.h>
  63 #include <linux/slab.h>
  64
  65 #include <linux/ipv6.h>
  66 #include <linux/icmpv6.h>
  67 #include <linux/random.h>
  68 #include <linux/seq_file.h>
  69
  70 #include <net/protocol.h>
  71 #include <net/ndisc.h>
  72 #include <net/ip.h>
  73 #include <net/ipv6.h>
  74 #include <net/transp_v6.h>
  75 #include <net/addrconf.h>
  76 #include <net/ip6_route.h>
  77 #include <net/inet_common.h>
  78 #include <net/inet_ecn.h>
  79 #include <net/sctp/sctp.h>
  80
  81 #include <asm/uaccess.h>
  82
  83 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  84                                          union sctp_addr *s2);
  85 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  86                               __be16 port);
  87 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  88                             const union sctp_addr *addr2);
  89
  90 /* Event handler for inet6 address addition/deletion events.
  91  * The sctp_local_addr_list needs to be protocted by a spin lock since
  92  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  93  * time and thus corrupt the list.
  94  * The reader side is protected with RCU.
  95  */
  96 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  97                                 void *ptr)
  98 {
  99         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
 100         struct sctp_sockaddr_entry *addr = NULL;
 101         struct sctp_sockaddr_entry *temp;
 102         int found = 0;
 103
 104         switch (ev) {
 105         case NETDEV_UP:
 106                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 107                 if (addr) {
 108                         addr->a.v6.sin6_family = AF_INET6;
 109                         addr->a.v6.sin6_port = 0;
 110                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifa->addr);
 111                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 112                         addr->valid = 1;
 113                         spin_lock_bh(&sctp_local_addr_lock);
 114                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
 115                         sctp_addr_wq_mgmt(addr, SCTP_ADDR_NEW);
 116                         spin_unlock_bh(&sctp_local_addr_lock);
 117                 }
 118                 break;
 119         case NETDEV_DOWN:
 120                 spin_lock_bh(&sctp_local_addr_lock);
 121                 list_for_each_entry_safe(addr, temp,
 122                                         &sctp_local_addr_list, list) {
 123                         if (addr->a.sa.sa_family == AF_INET6 &&
 124                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 125                                                 &ifa->addr)) {
 126                                 sctp_addr_wq_mgmt(addr, SCTP_ADDR_DEL);
 127                                 found = 1;
 128                                 addr->valid = 0;
 129                                 list_del_rcu(&addr->list);
 130                                 break;
 131                         }
 132                 }
 133                 spin_unlock_bh(&sctp_local_addr_lock);
 134                 if (found)
 135                         kfree_rcu(addr, rcu);
 136                 break;
 137         }
 138
 139         return NOTIFY_DONE;
 140 }
 141
 142 static struct notifier_block sctp_inet6addr_notifier = {
 143         .notifier_call = sctp_inet6addr_event,
 144 };
 145
 146 /* ICMP error handler. */
 147 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 148                              u8 type, u8 code, int offset, __be32 info)
 149 {
 150         struct inet6_dev *idev;
 151         struct sock *sk;
 152         struct sctp_association *asoc;
 153         struct sctp_transport *transport;
 154         struct ipv6_pinfo *np;
 155         sk_buff_data_t saveip, savesctp;
 156         int err;
 157
 158         idev = in6_dev_get(skb->dev);
 159
 160         /* Fix up skb to look at the embedded net header. */
 161         saveip   = skb->network_header;
 162         savesctp = skb->transport_header;
 163         skb_reset_network_header(skb);
 164         skb_set_transport_header(skb, offset);
 165         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 166         /* Put back, the original pointers. */
 167         skb->network_header   = saveip;
 168         skb->transport_header = savesctp;
 169         if (!sk) {
 170                 ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
 171                 goto out;
 172         }
 173
 174         /* Warning:  The sock lock is held.  Remember to call
 175          * sctp_err_finish!
 176          */
 177
 178         switch (type) {
 179         case ICMPV6_PKT_TOOBIG:
 180                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 181                 goto out_unlock;
 182         case ICMPV6_PARAMPROB:
 183                 if (ICMPV6_UNK_NEXTHDR == code) {
 184                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 185                         goto out_unlock;
 186                 }
 187                 break;
 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, asoc);
 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
 214         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 215                           __func__, skb, skb->len,
 216                           &fl6->saddr, &fl6->daddr);
 217
 218         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 219
 220         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 221                 skb->local_df = 1;
 222
 223         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 224
 225         return ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 226 }
 227
 228 /* Returns the dst cache entry for the given source and destination ip
 229  * addresses.
 230  */
 231 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 232                             struct flowi *fl, struct sock *sk)
 233 {
 234         struct sctp_association *asoc = t->asoc;
 235         struct dst_entry *dst = NULL;
 236         struct flowi6 *fl6 = &fl->u.ip6;
 237         struct sctp_bind_addr *bp;
 238         struct ipv6_pinfo *np = inet6_sk(sk);
 239         struct sctp_sockaddr_entry *laddr;
 240         union sctp_addr *baddr = NULL;
 241         union sctp_addr *daddr = &t->ipaddr;
 242         union sctp_addr dst_saddr;
 243         struct in6_addr *final_p, final;
 244         __u8 matchlen = 0;
 245         __u8 bmatchlen;
 246         sctp_scope_t scope;
 247
 248         memset(fl6, 0, sizeof(struct flowi6));
 249         ipv6_addr_copy(&fl6->daddr, &daddr->v6.sin6_addr);
 250         fl6->fl6_dport = daddr->v6.sin6_port;
 251         fl6->flowi6_proto = IPPROTO_SCTP;
 252         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 253                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 254
 255         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 256
 257         if (asoc)
 258                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 259
 260         if (saddr) {
 261                 ipv6_addr_copy(&fl6->saddr, &saddr->v6.sin6_addr);
 262                 fl6->fl6_sport = saddr->v6.sin6_port;
 263                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
 264         }
 265
 266         final_p = fl6_update_dst(fl6, np->opt, &final);
 267         dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
 268         if (!asoc || saddr)
 269                 goto out;
 270
 271         bp = &asoc->base.bind_addr;
 272         scope = sctp_scope(daddr);
 273         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 274          * to see if we can use it.
 275          */
 276         if (!IS_ERR(dst)) {
 277                 /* Walk through the bind address list and look for a bind
 278                  * address that matches the source address of the returned dst.
 279                  */
 280                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 281                 rcu_read_lock();
 282                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 283                         if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
 284                                 continue;
 285
 286                         /* Do not compare against v4 addrs */
 287                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 288                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 289                                 rcu_read_unlock();
 290                                 goto out;
 291                         }
 292                 }
 293                 rcu_read_unlock();
 294                 /* None of the bound addresses match the source address of the
 295                  * dst. So release it.
 296                  */
 297                 dst_release(dst);
 298                 dst = NULL;
 299         }
 300
 301         /* Walk through the bind address list and try to get the
 302          * best source address for a given destination.
 303          */
 304         rcu_read_lock();
 305         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 306                 if (!laddr->valid && laddr->state != SCTP_ADDR_SRC)
 307                         continue;
 308                 if ((laddr->a.sa.sa_family == AF_INET6) &&
 309                     (scope <= sctp_scope(&laddr->a))) {
 310                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 311                         if (!baddr || (matchlen < bmatchlen)) {
 312                                 baddr = &laddr->a;
 313                                 matchlen = bmatchlen;
 314                         }
 315                 }
 316         }
 317         if (baddr) {
 318                 ipv6_addr_copy(&fl6->saddr, &baddr->v6.sin6_addr);
 319                 fl6->fl6_sport = baddr->v6.sin6_port;
 320                 final_p = fl6_update_dst(fl6, np->opt, &final);
 321                 dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
 322         }
 323         rcu_read_unlock();
 324
 325 out:
 326         if (!IS_ERR(dst)) {
 327                 struct rt6_info *rt;
 328                 rt = (struct rt6_info *)dst;
 329                 t->dst = dst;
 330                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 331                         &rt->rt6i_dst.addr, &fl6->saddr);
 332         } else {
 333                 t->dst = NULL;
 334                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
 335         }
 336 }
 337
 338 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 339  * addresses.
 340  */
 341 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 342                                          union sctp_addr *s2)
 343 {
 344         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 345 }
 346
 347 /* Fills in the source address(saddr) based on the destination address(daddr)
 348  * and asoc's bind address list.
 349  */
 350 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 351                               struct sctp_transport *t,
 352                               struct flowi *fl)
 353 {
 354         struct flowi6 *fl6 = &fl->u.ip6;
 355         union sctp_addr *saddr = &t->saddr;
 356
 357         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 358
 359         if (t->dst) {
 360                 saddr->v6.sin6_family = AF_INET6;
 361                 ipv6_addr_copy(&saddr->v6.sin6_addr, &fl6->saddr);
 362         }
 363 }
 364
 365 /* Make a copy of all potential local addresses. */
 366 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 367                                   struct net_device *dev)
 368 {
 369         struct inet6_dev *in6_dev;
 370         struct inet6_ifaddr *ifp;
 371         struct sctp_sockaddr_entry *addr;
 372
 373         rcu_read_lock();
 374         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 375                 rcu_read_unlock();
 376                 return;
 377         }
 378
 379         read_lock_bh(&in6_dev->lock);
 380         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 381                 /* Add the address to the local list.  */
 382                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 383                 if (addr) {
 384                         addr->a.v6.sin6_family = AF_INET6;
 385                         addr->a.v6.sin6_port = 0;
 386                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifp->addr);
 387                         addr->a.v6.sin6_scope_id = dev->ifindex;
 388                         addr->valid = 1;
 389                         INIT_LIST_HEAD(&addr->list);
 390                         list_add_tail(&addr->list, addrlist);
 391                 }
 392         }
 393
 394         read_unlock_bh(&in6_dev->lock);
 395         rcu_read_unlock();
 396 }
 397
 398 /* Initialize a sockaddr_storage from in incoming skb. */
 399 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 400                              int is_saddr)
 401 {
 402         void *from;
 403         __be16 *port;
 404         struct sctphdr *sh;
 405
 406         port = &addr->v6.sin6_port;
 407         addr->v6.sin6_family = AF_INET6;
 408         addr->v6.sin6_flowinfo = 0; /* FIXME */
 409         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 410
 411         sh = sctp_hdr(skb);
 412         if (is_saddr) {
 413                 *port  = sh->source;
 414                 from = &ipv6_hdr(skb)->saddr;
 415         } else {
 416                 *port = sh->dest;
 417                 from = &ipv6_hdr(skb)->daddr;
 418         }
 419         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 420 }
 421
 422 /* Initialize an sctp_addr from a socket. */
 423 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 424 {
 425         addr->v6.sin6_family = AF_INET6;
 426         addr->v6.sin6_port = 0;
 427         ipv6_addr_copy(&addr->v6.sin6_addr, &inet6_sk(sk)->rcv_saddr);
 428 }
 429
 430 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 431 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 432 {
 433         if (addr->sa.sa_family == AF_INET) {
 434                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 435                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 436                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 437                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 438                         addr->v4.sin_addr.s_addr;
 439         } else {
 440                 ipv6_addr_copy(&inet6_sk(sk)->rcv_saddr, &addr->v6.sin6_addr);
 441         }
 442 }
 443
 444 /* Initialize sk->sk_daddr from sctp_addr. */
 445 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 446 {
 447         if (addr->sa.sa_family == AF_INET) {
 448                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 449                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 450                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 451                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 452         } else {
 453                 ipv6_addr_copy(&inet6_sk(sk)->daddr, &addr->v6.sin6_addr);
 454         }
 455 }
 456
 457 /* Initialize a sctp_addr from an address parameter. */
 458 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 459                                     union sctp_addr_param *param,
 460                                     __be16 port, int iif)
 461 {
 462         addr->v6.sin6_family = AF_INET6;
 463         addr->v6.sin6_port = port;
 464         addr->v6.sin6_flowinfo = 0; /* BUG */
 465         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 466         addr->v6.sin6_scope_id = iif;
 467 }
 468
 469 /* Initialize an address parameter from a sctp_addr and return the length
 470  * of the address parameter.
 471  */
 472 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 473                                  union sctp_addr_param *param)
 474 {
 475         int length = sizeof(sctp_ipv6addr_param_t);
 476
 477         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 478         param->v6.param_hdr.length = htons(length);
 479         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 480
 481         return length;
 482 }
 483
 484 /* Initialize a sctp_addr from struct in6_addr. */
 485 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 486                               __be16 port)
 487 {
 488         addr->sa.sa_family = AF_INET6;
 489         addr->v6.sin6_port = port;
 490         addr->v6.sin6_flowinfo = 0;
 491         ipv6_addr_copy(&addr->v6.sin6_addr, saddr);
 492         addr->v6.sin6_scope_id = 0;
 493 }
 494
 495 /* Compare addresses exactly.
 496  * v4-mapped-v6 is also in consideration.
 497  */
 498 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 499                             const union sctp_addr *addr2)
 500 {
 501         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 502                 if (addr1->sa.sa_family == AF_INET &&
 503                     addr2->sa.sa_family == AF_INET6 &&
 504                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 505                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 506                             addr2->v6.sin6_addr.s6_addr32[3] ==
 507                             addr1->v4.sin_addr.s_addr)
 508                                 return 1;
 509                 }
 510                 if (addr2->sa.sa_family == AF_INET &&
 511                     addr1->sa.sa_family == AF_INET6 &&
 512                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 513                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 514                             addr1->v6.sin6_addr.s6_addr32[3] ==
 515                             addr2->v4.sin_addr.s_addr)
 516                                 return 1;
 517                 }
 518                 return 0;
 519         }
 520         if (addr1->v6.sin6_port != addr2->v6.sin6_port)
 521                 return 0;
 522         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 523                 return 0;
 524         /* If this is a linklocal address, compare the scope_id. */
 525         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 526                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 527                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 528                         return 0;
 529                 }
 530         }
 531
 532         return 1;
 533 }
 534
 535 /* Initialize addr struct to INADDR_ANY. */
 536 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 537 {
 538         memset(addr, 0x00, sizeof(union sctp_addr));
 539         addr->v6.sin6_family = AF_INET6;
 540         addr->v6.sin6_port = port;
 541 }
 542
 543 /* Is this a wildcard address? */
 544 static int sctp_v6_is_any(const union sctp_addr *addr)
 545 {
 546         return ipv6_addr_any(&addr->v6.sin6_addr);
 547 }
 548
 549 /* Should this be available for binding?   */
 550 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 551 {
 552         int type;
 553         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 554
 555         type = ipv6_addr_type(in6);
 556         if (IPV6_ADDR_ANY == type)
 557                 return 1;
 558         if (type == IPV6_ADDR_MAPPED) {
 559                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 560                         return 0;
 561                 sctp_v6_map_v4(addr);
 562                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 563         }
 564         if (!(type & IPV6_ADDR_UNICAST))
 565                 return 0;
 566
 567         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 568 }
 569
 570 /* This function checks if the address is a valid address to be used for
 571  * SCTP.
 572  *
 573  * Output:
 574  * Return 0 - If the address is a non-unicast or an illegal address.
 575  * Return 1 - If the address is a unicast.
 576  */
 577 static int sctp_v6_addr_valid(union sctp_addr *addr,
 578                               struct sctp_sock *sp,
 579                               const struct sk_buff *skb)
 580 {
 581         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 582
 583         /* Support v4-mapped-v6 address. */
 584         if (ret == IPV6_ADDR_MAPPED) {
 585                 /* Note: This routine is used in input, so v4-mapped-v6
 586                  * are disallowed here when there is no sctp_sock.
 587                  */
 588                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 589                         return 0;
 590                 sctp_v6_map_v4(addr);
 591                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 592         }
 593
 594         /* Is this a non-unicast address */
 595         if (!(ret & IPV6_ADDR_UNICAST))
 596                 return 0;
 597
 598         return 1;
 599 }
 600
 601 /* What is the scope of 'addr'?  */
 602 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 603 {
 604         int v6scope;
 605         sctp_scope_t retval;
 606
 607         /* The IPv6 scope is really a set of bit fields.
 608          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 609          */
 610
 611         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 612         switch (v6scope) {
 613         case IFA_HOST:
 614                 retval = SCTP_SCOPE_LOOPBACK;
 615                 break;
 616         case IFA_LINK:
 617                 retval = SCTP_SCOPE_LINK;
 618                 break;
 619         case IFA_SITE:
 620                 retval = SCTP_SCOPE_PRIVATE;
 621                 break;
 622         default:
 623                 retval = SCTP_SCOPE_GLOBAL;
 624                 break;
 625         }
 626
 627         return retval;
 628 }
 629
 630 /* Create and initialize a new sk for the socket to be returned by accept(). */
 631 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 632                                              struct sctp_association *asoc)
 633 {
 634         struct sock *newsk;
 635         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 636         struct sctp6_sock *newsctp6sk;
 637         struct ipv6_txoptions *opt;
 638
 639         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 640         if (!newsk)
 641                 goto out;
 642
 643         sock_init_data(NULL, newsk);
 644
 645         sctp_copy_sock(newsk, sk, asoc);
 646         sock_reset_flag(sk, SOCK_ZAPPED);
 647
 648         newsctp6sk = (struct sctp6_sock *)newsk;
 649         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 650
 651         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 652
 653         newnp = inet6_sk(newsk);
 654
 655         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 656         newnp->ipv6_mc_list = NULL;
 657         newnp->ipv6_ac_list = NULL;
 658         newnp->ipv6_fl_list = NULL;
 659
 660         rcu_read_lock();
 661         opt = rcu_dereference(np->opt);
 662         if (opt)
 663                 opt = ipv6_dup_options(newsk, opt);
 664         RCU_INIT_POINTER(newnp->opt, opt);
 665         rcu_read_unlock();
 666
 667         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 668          * and getpeername().
 669          */
 670         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 671
 672         sk_refcnt_debug_inc(newsk);
 673
 674         if (newsk->sk_prot->init(newsk)) {
 675                 sk_common_release(newsk);
 676                 newsk = NULL;
 677         }
 678
 679 out:
 680         return newsk;
 681 }
 682
 683 /* Format a sockaddr for return to user space. This makes sure the return is
 684  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 685  */
 686 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 687 {
 688         if (sp->v4mapped) {
 689                 if (addr->sa.sa_family == AF_INET)
 690                         sctp_v4_map_v6(addr);
 691         } else {
 692                 if (addr->sa.sa_family == AF_INET6 &&
 693                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 694                         sctp_v6_map_v4(addr);
 695         }
 696
 697         if (addr->sa.sa_family == AF_INET)
 698                 return sizeof(struct sockaddr_in);
 699         return sizeof(struct sockaddr_in6);
 700 }
 701
 702 /* Where did this skb come from?  */
 703 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 704 {
 705         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 706         return opt->iif;
 707 }
 708
 709 /* Was this packet marked by Explicit Congestion Notification? */
 710 static int sctp_v6_is_ce(const struct sk_buff *skb)
 711 {
 712         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 713 }
 714
 715 /* Dump the v6 addr to the seq file. */
 716 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 717 {
 718         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 719 }
 720
 721 static void sctp_v6_ecn_capable(struct sock *sk)
 722 {
 723         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 724 }
 725
 726 /* Initialize a PF_INET msgname from a ulpevent. */
 727 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 728                                      char *msgname, int *addrlen)
 729 {
 730         union sctp_addr *addr;
 731         struct sctp_association *asoc;
 732         union sctp_addr *paddr;
 733
 734         if (!msgname)
 735                 return;
 736
 737         addr = (union sctp_addr *)msgname;
 738         asoc = event->asoc;
 739         paddr = &asoc->peer.primary_addr;
 740
 741         if (paddr->sa.sa_family == AF_INET) {
 742                 addr->v4.sin_family = AF_INET;
 743                 addr->v4.sin_port = htons(asoc->peer.port);
 744                 addr->v4.sin_addr = paddr->v4.sin_addr;
 745         } else {
 746                 addr->v6.sin6_family = AF_INET6;
 747                 addr->v6.sin6_flowinfo = 0;
 748                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 749                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 750                 else
 751                         addr->v6.sin6_scope_id = 0;
 752                 addr->v6.sin6_port = htons(asoc->peer.port);
 753                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 754         }
 755
 756         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 757 }
 758
 759 /* Initialize a msg_name from an inbound skb. */
 760 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 761                                    int *addr_len)
 762 {
 763         union sctp_addr *addr;
 764         struct sctphdr *sh;
 765
 766         if (!msgname)
 767                 return;
 768
 769         addr = (union sctp_addr *)msgname;
 770         sh = sctp_hdr(skb);
 771
 772         if (ip_hdr(skb)->version == 4) {
 773                 addr->v4.sin_family = AF_INET;
 774                 addr->v4.sin_port = sh->source;
 775                 addr->v4.sin_addr.s_addr =  ip_hdr(skb)->saddr;
 776         } else {
 777                 addr->v6.sin6_family = AF_INET6;
 778                 addr->v6.sin6_flowinfo = 0;
 779                 addr->v6.sin6_port = sh->source;
 780                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 781                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 782                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 783                         addr->v6.sin6_scope_id = ev->iif;
 784                 } else {
 785                         addr->v6.sin6_scope_id = 0;
 786                 }
 787         }
 788
 789         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 790 }
 791
 792 /* Do we support this AF? */
 793 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 794 {
 795         switch (family) {
 796         case AF_INET6:
 797                 return 1;
 798         /* v4-mapped-v6 addresses */
 799         case AF_INET:
 800                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 801                         return 1;
 802         default:
 803                 return 0;
 804         }
 805 }
 806
 807 /* Address matching with wildcards allowed.  This extra level
 808  * of indirection lets us choose whether a PF_INET6 should
 809  * disallow any v4 addresses if we so choose.
 810  */
 811 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 812                                const union sctp_addr *addr2,
 813                                struct sctp_sock *opt)
 814 {
 815         struct sctp_af *af1, *af2;
 816         struct sock *sk = sctp_opt2sk(opt);
 817
 818         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 819         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 820
 821         if (!af1 || !af2)
 822                 return 0;
 823
 824         /* If the socket is IPv6 only, v4 addrs will not match */
 825         if (__ipv6_only_sock(sk) && af1 != af2)
 826                 return 0;
 827
 828         /* Today, wildcard AF_INET/AF_INET6. */
 829         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 830                 return 1;
 831
 832         if (addr1->sa.sa_family != addr2->sa.sa_family)
 833                 return 0;
 834
 835         return af1->cmp_addr(addr1, addr2);
 836 }
 837
 838 /* Verify that the provided sockaddr looks bindable.   Common verification,
 839  * has already been taken care of.
 840  */
 841 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 842 {
 843         struct sctp_af *af;
 844
 845         /* ASSERT: address family has already been verified. */
 846         if (addr->sa.sa_family != AF_INET6)
 847                 af = sctp_get_af_specific(addr->sa.sa_family);
 848         else {
 849                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 850                 struct net_device *dev;
 851
 852                 if (type & IPV6_ADDR_LINKLOCAL) {
 853                         if (!addr->v6.sin6_scope_id)
 854                                 return 0;
 855                         rcu_read_lock();
 856                         dev = dev_get_by_index_rcu(&init_net,
 857                                                    addr->v6.sin6_scope_id);
 858                         if (!dev ||
 859                             !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 860                                            dev, 0)) {
 861                                 rcu_read_unlock();
 862                                 return 0;
 863                         }
 864                         rcu_read_unlock();
 865                 }
 866
 867                 af = opt->pf->af;
 868         }
 869         return af->available(addr, opt);
 870 }
 871
 872 /* Verify that the provided sockaddr looks sendable.   Common verification,
 873  * has already been taken care of.
 874  */
 875 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 876 {
 877         struct sctp_af *af = NULL;
 878
 879         /* ASSERT: address family has already been verified. */
 880         if (addr->sa.sa_family != AF_INET6)
 881                 af = sctp_get_af_specific(addr->sa.sa_family);
 882         else {
 883                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 884                 struct net_device *dev;
 885
 886                 if (type & IPV6_ADDR_LINKLOCAL) {
 887                         if (!addr->v6.sin6_scope_id)
 888                                 return 0;
 889                         rcu_read_lock();
 890                         dev = dev_get_by_index_rcu(&init_net,
 891                                                    addr->v6.sin6_scope_id);
 892                         rcu_read_unlock();
 893                         if (!dev)
 894                                 return 0;
 895                 }
 896                 af = opt->pf->af;
 897         }
 898
 899         return af != NULL;
 900 }
 901
 902 /* Fill in Supported Address Type information for INIT and INIT-ACK
 903  * chunks.   Note: In the future, we may want to look at sock options
 904  * to determine whether a PF_INET6 socket really wants to have IPV4
 905  * addresses.
 906  * Returns number of addresses supported.
 907  */
 908 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 909                                       __be16 *types)
 910 {
 911         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 912         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 913                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 914                 return 2;
 915         }
 916         return 1;
 917 }
 918
 919 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 920 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 921                         int *uaddr_len, int peer)
 922 {
 923         int rc;
 924
 925         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 926
 927         if (rc != 0)
 928                 return rc;
 929
 930         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 931                                           (union sctp_addr *)uaddr);
 932
 933         return rc;
 934 }
 935
 936 static const struct proto_ops inet6_seqpacket_ops = {
 937         .family            = PF_INET6,
 938         .owner             = THIS_MODULE,
 939         .release           = inet6_release,
 940         .bind              = inet6_bind,
 941         .connect           = inet_dgram_connect,
 942         .socketpair        = sock_no_socketpair,
 943         .accept            = inet_accept,
 944         .getname           = sctp_getname,
 945         .poll              = sctp_poll,
 946         .ioctl             = inet6_ioctl,
 947         .listen            = sctp_inet_listen,
 948         .shutdown          = inet_shutdown,
 949         .setsockopt        = sock_common_setsockopt,
 950         .getsockopt        = sock_common_getsockopt,
 951         .sendmsg           = inet_sendmsg,
 952         .recvmsg           = sock_common_recvmsg,
 953         .mmap              = sock_no_mmap,
 954 #ifdef CONFIG_COMPAT
 955         .compat_setsockopt = compat_sock_common_setsockopt,
 956         .compat_getsockopt = compat_sock_common_getsockopt,
 957 #endif
 958 };
 959
 960 static struct inet_protosw sctpv6_seqpacket_protosw = {
 961         .type          = SOCK_SEQPACKET,
 962         .protocol      = IPPROTO_SCTP,
 963         .prot          = &sctpv6_prot,
 964         .ops           = &inet6_seqpacket_ops,
 965         .no_check      = 0,
 966         .flags         = SCTP_PROTOSW_FLAG
 967 };
 968 static struct inet_protosw sctpv6_stream_protosw = {
 969         .type          = SOCK_STREAM,
 970         .protocol      = IPPROTO_SCTP,
 971         .prot          = &sctpv6_prot,
 972         .ops           = &inet6_seqpacket_ops,
 973         .no_check      = 0,
 974         .flags         = SCTP_PROTOSW_FLAG,
 975 };
 976
 977 static int sctp6_rcv(struct sk_buff *skb)
 978 {
 979         return sctp_rcv(skb) ? -1 : 0;
 980 }
 981
 982 static const struct inet6_protocol sctpv6_protocol = {
 983         .handler      = sctp6_rcv,
 984         .err_handler  = sctp_v6_err,
 985         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 986 };
 987
 988 static struct sctp_af sctp_af_inet6 = {
 989         .sa_family         = AF_INET6,
 990         .sctp_xmit         = sctp_v6_xmit,
 991         .setsockopt        = ipv6_setsockopt,
 992         .getsockopt        = ipv6_getsockopt,
 993         .get_dst           = sctp_v6_get_dst,
 994         .get_saddr         = sctp_v6_get_saddr,
 995         .copy_addrlist     = sctp_v6_copy_addrlist,
 996         .from_skb          = sctp_v6_from_skb,
 997         .from_sk           = sctp_v6_from_sk,
 998         .from_addr_param   = sctp_v6_from_addr_param,
 999         .to_addr_param     = sctp_v6_to_addr_param,
1000         .cmp_addr          = sctp_v6_cmp_addr,
1001         .scope             = sctp_v6_scope,
1002         .addr_valid        = sctp_v6_addr_valid,
1003         .inaddr_any        = sctp_v6_inaddr_any,
1004         .is_any            = sctp_v6_is_any,
1005         .available         = sctp_v6_available,
1006         .skb_iif           = sctp_v6_skb_iif,
1007         .is_ce             = sctp_v6_is_ce,
1008         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1009         .ecn_capable       = sctp_v6_ecn_capable,
1010         .net_header_len    = sizeof(struct ipv6hdr),
1011         .sockaddr_len      = sizeof(struct sockaddr_in6),
1012 #ifdef CONFIG_COMPAT
1013         .compat_setsockopt = compat_ipv6_setsockopt,
1014         .compat_getsockopt = compat_ipv6_getsockopt,
1015 #endif
1016 };
1017
1018 static struct sctp_pf sctp_pf_inet6 = {
1019         .event_msgname = sctp_inet6_event_msgname,
1020         .skb_msgname   = sctp_inet6_skb_msgname,
1021         .af_supported  = sctp_inet6_af_supported,
1022         .cmp_addr      = sctp_inet6_cmp_addr,
1023         .bind_verify   = sctp_inet6_bind_verify,
1024         .send_verify   = sctp_inet6_send_verify,
1025         .supported_addrs = sctp_inet6_supported_addrs,
1026         .create_accept_sk = sctp_v6_create_accept_sk,
1027         .addr_to_user  = sctp_v6_addr_to_user,
1028         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1029         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1030         .af            = &sctp_af_inet6,
1031 };
1032
1033 /* Initialize IPv6 support and register with socket layer.  */
1034 void sctp_v6_pf_init(void)
1035 {
1036         /* Register the SCTP specific PF_INET6 functions. */
1037         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1038
1039         /* Register the SCTP specific AF_INET6 functions. */
1040         sctp_register_af(&sctp_af_inet6);
1041 }
1042
1043 void sctp_v6_pf_exit(void)
1044 {
1045         list_del(&sctp_af_inet6.list);
1046 }
1047
1048 /* Initialize IPv6 support and register with socket layer.  */
1049 int sctp_v6_protosw_init(void)
1050 {
1051         int rc;
1052
1053         rc = proto_register(&sctpv6_prot, 1);
1054         if (rc)
1055                 return rc;
1056
1057         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1058         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1059         inet6_register_protosw(&sctpv6_stream_protosw);
1060
1061         return 0;
1062 }
1063
1064 void sctp_v6_protosw_exit(void)
1065 {
1066         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1067         inet6_unregister_protosw(&sctpv6_stream_protosw);
1068         proto_unregister(&sctpv6_prot);
1069 }
1070
1071
1072 /* Register with inet6 layer. */
1073 int sctp_v6_add_protocol(void)
1074 {
1075         /* Register notifier for inet6 address additions/deletions. */
1076         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1077
1078         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1079                 return -EAGAIN;
1080
1081         return 0;
1082 }
1083
1084 /* Unregister with inet6 layer. */
1085 void sctp_v6_del_protocol(void)
1086 {
1087         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1088         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1089 }