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         struct net *net = dev_net(ifa->idev->dev);
 103         int found = 0;
 104
 105         switch (ev) {
 106         case NETDEV_UP:
 107                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 108                 if (addr) {
 109                         addr->a.v6.sin6_family = AF_INET6;
 110                         addr->a.v6.sin6_port = 0;
 111                         addr->a.v6.sin6_addr = ifa->addr;
 112                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 113                         addr->valid = 1;
 114                         spin_lock_bh(&net->sctp.local_addr_lock);
 115                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 116                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 117                         spin_unlock_bh(&net->sctp.local_addr_lock);
 118                 }
 119                 break;
 120         case NETDEV_DOWN:
 121                 spin_lock_bh(&net->sctp.local_addr_lock);
 122                 list_for_each_entry_safe(addr, temp,
 123                                         &net->sctp.local_addr_list, list) {
 124                         if (addr->a.sa.sa_family == AF_INET6 &&
 125                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 126                                                 &ifa->addr)) {
 127                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 128                                 found = 1;
 129                                 addr->valid = 0;
 130                                 list_del_rcu(&addr->list);
 131                                 break;
 132                         }
 133                 }
 134                 spin_unlock_bh(&net->sctp.local_addr_lock);
 135                 if (found)
 136                         kfree_rcu(addr, rcu);
 137                 break;
 138         }
 139
 140         return NOTIFY_DONE;
 141 }
 142
 143 static struct notifier_block sctp_inet6addr_notifier = {
 144         .notifier_call = sctp_inet6addr_event,
 145 };
 146
 147 /* ICMP error handler. */
 148 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 149                              u8 type, u8 code, int offset, __be32 info)
 150 {
 151         struct inet6_dev *idev;
 152         struct sock *sk;
 153         struct sctp_association *asoc;
 154         struct sctp_transport *transport;
 155         struct ipv6_pinfo *np;
 156         sk_buff_data_t saveip, savesctp;
 157         int err;
 158         struct net *net = dev_net(skb->dev);
 159
 160         idev = in6_dev_get(skb->dev);
 161
 162         /* Fix up skb to look at the embedded net header. */
 163         saveip   = skb->network_header;
 164         savesctp = skb->transport_header;
 165         skb_reset_network_header(skb);
 166         skb_set_transport_header(skb, offset);
 167         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 168         /* Put back, the original pointers. */
 169         skb->network_header   = saveip;
 170         skb->transport_header = savesctp;
 171         if (!sk) {
 172                 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_INERRORS);
 173                 goto out;
 174         }
 175
 176         /* Warning:  The sock lock is held.  Remember to call
 177          * sctp_err_finish!
 178          */
 179
 180         switch (type) {
 181         case ICMPV6_PKT_TOOBIG:
 182                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 183                 goto out_unlock;
 184         case ICMPV6_PARAMPROB:
 185                 if (ICMPV6_UNK_NEXTHDR == code) {
 186                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 187                         goto out_unlock;
 188                 }
 189                 break;
 190         case NDISC_REDIRECT:
 191                 sctp_icmp_redirect(sk, transport, skb);
 192                 break;
 193         default:
 194                 break;
 195         }
 196
 197         np = inet6_sk(sk);
 198         icmpv6_err_convert(type, code, &err);
 199         if (!sock_owned_by_user(sk) && np->recverr) {
 200                 sk->sk_err = err;
 201                 sk->sk_error_report(sk);
 202         } else {  /* Only an error on timeout */
 203                 sk->sk_err_soft = err;
 204         }
 205
 206 out_unlock:
 207         sctp_err_finish(sk, asoc);
 208 out:
 209         if (likely(idev != NULL))
 210                 in6_dev_put(idev);
 211 }
 212
 213 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 214 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 215 {
 216         struct sock *sk = skb->sk;
 217         struct ipv6_pinfo *np = inet6_sk(sk);
 218         struct flowi6 fl6;
 219
 220         memset(&fl6, 0, sizeof(fl6));
 221
 222         fl6.flowi6_proto = sk->sk_protocol;
 223
 224         /* Fill in the dest address from the route entry passed with the skb
 225          * and the source address from the transport.
 226          */
 227         fl6.daddr = transport->ipaddr.v6.sin6_addr;
 228         fl6.saddr = transport->saddr.v6.sin6_addr;
 229
 230         fl6.flowlabel = np->flow_label;
 231         IP6_ECN_flow_xmit(sk, fl6.flowlabel);
 232         if (ipv6_addr_type(&fl6.saddr) & IPV6_ADDR_LINKLOCAL)
 233                 fl6.flowi6_oif = transport->saddr.v6.sin6_scope_id;
 234         else
 235                 fl6.flowi6_oif = sk->sk_bound_dev_if;
 236
 237         if (np->opt && np->opt->srcrt) {
 238                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 239                 fl6.daddr = *rt0->addr;
 240         }
 241
 242         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 243                           __func__, skb, skb->len,
 244                           &fl6.saddr, &fl6.daddr);
 245
 246         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 247
 248         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 249                 skb->local_df = 1;
 250
 251         return ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 252 }
 253
 254 /* Returns the dst cache entry for the given source and destination ip
 255  * addresses.
 256  */
 257 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 258                             struct flowi *fl, struct sock *sk)
 259 {
 260         struct sctp_association *asoc = t->asoc;
 261         struct dst_entry *dst = NULL;
 262         struct flowi6 *fl6 = &fl->u.ip6;
 263         struct sctp_bind_addr *bp;
 264         struct sctp_sockaddr_entry *laddr;
 265         union sctp_addr *baddr = NULL;
 266         union sctp_addr *daddr = &t->ipaddr;
 267         union sctp_addr dst_saddr;
 268         __u8 matchlen = 0;
 269         __u8 bmatchlen;
 270         sctp_scope_t scope;
 271
 272         memset(fl6, 0, sizeof(struct flowi6));
 273         fl6->daddr = daddr->v6.sin6_addr;
 274         fl6->fl6_dport = daddr->v6.sin6_port;
 275         fl6->flowi6_proto = IPPROTO_SCTP;
 276         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 277                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 278
 279         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 280
 281         if (asoc)
 282                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 283
 284         if (saddr) {
 285                 fl6->saddr = saddr->v6.sin6_addr;
 286                 fl6->fl6_sport = saddr->v6.sin6_port;
 287                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
 288         }
 289
 290         dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 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_SRC))
 307                                 continue;
 308
 309                         /* Do not compare against v4 addrs */
 310                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 311                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 312                                 rcu_read_unlock();
 313                                 goto out;
 314                         }
 315                 }
 316                 rcu_read_unlock();
 317                 /* None of the bound addresses match the source address of the
 318                  * dst. So release it.
 319                  */
 320                 dst_release(dst);
 321                 dst = NULL;
 322         }
 323
 324         /* Walk through the bind address list and try to get the
 325          * best source address for a given destination.
 326          */
 327         rcu_read_lock();
 328         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 329                 if (!laddr->valid)
 330                         continue;
 331                 if ((laddr->state == SCTP_ADDR_SRC) &&
 332                     (laddr->a.sa.sa_family == AF_INET6) &&
 333                     (scope <= sctp_scope(&laddr->a))) {
 334                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 335                         if (!baddr || (matchlen < bmatchlen)) {
 336                                 baddr = &laddr->a;
 337                                 matchlen = bmatchlen;
 338                         }
 339                 }
 340         }
 341         rcu_read_unlock();
 342         if (baddr) {
 343                 fl6->saddr = baddr->v6.sin6_addr;
 344                 fl6->fl6_sport = baddr->v6.sin6_port;
 345                 dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 346         }
 347
 348 out:
 349         if (!IS_ERR_OR_NULL(dst)) {
 350                 struct rt6_info *rt;
 351                 rt = (struct rt6_info *)dst;
 352                 t->dst = dst;
 353                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 354                         &rt->rt6i_dst.addr, &fl6->saddr);
 355         } else {
 356                 t->dst = NULL;
 357                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
 358         }
 359 }
 360
 361 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 362  * addresses.
 363  */
 364 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 365                                          union sctp_addr *s2)
 366 {
 367         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 368 }
 369
 370 /* Fills in the source address(saddr) based on the destination address(daddr)
 371  * and asoc's bind address list.
 372  */
 373 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 374                               struct sctp_transport *t,
 375                               struct flowi *fl)
 376 {
 377         struct flowi6 *fl6 = &fl->u.ip6;
 378         union sctp_addr *saddr = &t->saddr;
 379
 380         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 381
 382         if (t->dst) {
 383                 saddr->v6.sin6_family = AF_INET6;
 384                 saddr->v6.sin6_addr = fl6->saddr;
 385         }
 386 }
 387
 388 /* Make a copy of all potential local addresses. */
 389 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 390                                   struct net_device *dev)
 391 {
 392         struct inet6_dev *in6_dev;
 393         struct inet6_ifaddr *ifp;
 394         struct sctp_sockaddr_entry *addr;
 395
 396         rcu_read_lock();
 397         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 398                 rcu_read_unlock();
 399                 return;
 400         }
 401
 402         read_lock_bh(&in6_dev->lock);
 403         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 404                 /* Add the address to the local list.  */
 405                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 406                 if (addr) {
 407                         addr->a.v6.sin6_family = AF_INET6;
 408                         addr->a.v6.sin6_port = 0;
 409                         addr->a.v6.sin6_addr = ifp->addr;
 410                         addr->a.v6.sin6_scope_id = dev->ifindex;
 411                         addr->valid = 1;
 412                         INIT_LIST_HEAD(&addr->list);
 413                         list_add_tail(&addr->list, addrlist);
 414                 }
 415         }
 416
 417         read_unlock_bh(&in6_dev->lock);
 418         rcu_read_unlock();
 419 }
 420
 421 /* Initialize a sockaddr_storage from in incoming skb. */
 422 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 423                              int is_saddr)
 424 {
 425         __be16 *port;
 426         struct sctphdr *sh;
 427
 428         port = &addr->v6.sin6_port;
 429         addr->v6.sin6_family = AF_INET6;
 430         addr->v6.sin6_flowinfo = 0; /* FIXME */
 431         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 432
 433         sh = sctp_hdr(skb);
 434         if (is_saddr) {
 435                 *port  = sh->source;
 436                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 437         } else {
 438                 *port = sh->dest;
 439                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 440         }
 441 }
 442
 443 /* Initialize an sctp_addr from a socket. */
 444 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 445 {
 446         addr->v6.sin6_family = AF_INET6;
 447         addr->v6.sin6_port = 0;
 448         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 449 }
 450
 451 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 452 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 453 {
 454         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 455                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 456                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 457                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 458                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 459                         addr->v4.sin_addr.s_addr;
 460         } else {
 461                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 462         }
 463 }
 464
 465 /* Initialize sk->sk_daddr from sctp_addr. */
 466 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 467 {
 468         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 469                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 470                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 471                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 472                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 473         } else {
 474                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 475         }
 476 }
 477
 478 /* Initialize a sctp_addr from an address parameter. */
 479 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 480                                     union sctp_addr_param *param,
 481                                     __be16 port, int iif)
 482 {
 483         addr->v6.sin6_family = AF_INET6;
 484         addr->v6.sin6_port = port;
 485         addr->v6.sin6_flowinfo = 0; /* BUG */
 486         addr->v6.sin6_addr = param->v6.addr;
 487         addr->v6.sin6_scope_id = iif;
 488 }
 489
 490 /* Initialize an address parameter from a sctp_addr and return the length
 491  * of the address parameter.
 492  */
 493 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 494                                  union sctp_addr_param *param)
 495 {
 496         int length = sizeof(sctp_ipv6addr_param_t);
 497
 498         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 499         param->v6.param_hdr.length = htons(length);
 500         param->v6.addr = addr->v6.sin6_addr;
 501
 502         return length;
 503 }
 504
 505 /* Initialize a sctp_addr from struct in6_addr. */
 506 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 507                               __be16 port)
 508 {
 509         addr->sa.sa_family = AF_INET6;
 510         addr->v6.sin6_port = port;
 511         addr->v6.sin6_addr = *saddr;
 512 }
 513
 514 /* Compare addresses exactly.
 515  * v4-mapped-v6 is also in consideration.
 516  */
 517 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 518                             const union sctp_addr *addr2)
 519 {
 520         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 521                 if (addr1->sa.sa_family == AF_INET &&
 522                     addr2->sa.sa_family == AF_INET6 &&
 523                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 524                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 525                             addr2->v6.sin6_addr.s6_addr32[3] ==
 526                             addr1->v4.sin_addr.s_addr)
 527                                 return 1;
 528                 }
 529                 if (addr2->sa.sa_family == AF_INET &&
 530                     addr1->sa.sa_family == AF_INET6 &&
 531                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 532                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 533                             addr1->v6.sin6_addr.s6_addr32[3] ==
 534                             addr2->v4.sin_addr.s_addr)
 535                                 return 1;
 536                 }
 537                 return 0;
 538         }
 539         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 540                 return 0;
 541         /* If this is a linklocal address, compare the scope_id. */
 542         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 543                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 544                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 545                         return 0;
 546                 }
 547         }
 548
 549         return 1;
 550 }
 551
 552 /* Initialize addr struct to INADDR_ANY. */
 553 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 554 {
 555         memset(addr, 0x00, sizeof(union sctp_addr));
 556         addr->v6.sin6_family = AF_INET6;
 557         addr->v6.sin6_port = port;
 558 }
 559
 560 /* Is this a wildcard address? */
 561 static int sctp_v6_is_any(const union sctp_addr *addr)
 562 {
 563         return ipv6_addr_any(&addr->v6.sin6_addr);
 564 }
 565
 566 /* Should this be available for binding?   */
 567 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 568 {
 569         int type;
 570         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 571
 572         type = ipv6_addr_type(in6);
 573         if (IPV6_ADDR_ANY == type)
 574                 return 1;
 575         if (type == IPV6_ADDR_MAPPED) {
 576                 if (sp && !sp->v4mapped)
 577                         return 0;
 578                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 579                         return 0;
 580                 sctp_v6_map_v4(addr);
 581                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 582         }
 583         if (!(type & IPV6_ADDR_UNICAST))
 584                 return 0;
 585
 586         return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
 587 }
 588
 589 /* This function checks if the address is a valid address to be used for
 590  * SCTP.
 591  *
 592  * Output:
 593  * Return 0 - If the address is a non-unicast or an illegal address.
 594  * Return 1 - If the address is a unicast.
 595  */
 596 static int sctp_v6_addr_valid(union sctp_addr *addr,
 597                               struct sctp_sock *sp,
 598                               const struct sk_buff *skb)
 599 {
 600         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 601
 602         /* Support v4-mapped-v6 address. */
 603         if (ret == IPV6_ADDR_MAPPED) {
 604                 /* Note: This routine is used in input, so v4-mapped-v6
 605                  * are disallowed here when there is no sctp_sock.
 606                  */
 607                 if (!sp || !sp->v4mapped)
 608                         return 0;
 609                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 610                         return 0;
 611                 sctp_v6_map_v4(addr);
 612                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 613         }
 614
 615         /* Is this a non-unicast address */
 616         if (!(ret & IPV6_ADDR_UNICAST))
 617                 return 0;
 618
 619         return 1;
 620 }
 621
 622 /* What is the scope of 'addr'?  */
 623 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 624 {
 625         int v6scope;
 626         sctp_scope_t retval;
 627
 628         /* The IPv6 scope is really a set of bit fields.
 629          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 630          */
 631
 632         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 633         switch (v6scope) {
 634         case IFA_HOST:
 635                 retval = SCTP_SCOPE_LOOPBACK;
 636                 break;
 637         case IFA_LINK:
 638                 retval = SCTP_SCOPE_LINK;
 639                 break;
 640         case IFA_SITE:
 641                 retval = SCTP_SCOPE_PRIVATE;
 642                 break;
 643         default:
 644                 retval = SCTP_SCOPE_GLOBAL;
 645                 break;
 646         }
 647
 648         return retval;
 649 }
 650
 651 /* Create and initialize a new sk for the socket to be returned by accept(). */
 652 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 653                                              struct sctp_association *asoc)
 654 {
 655         struct sock *newsk;
 656         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 657         struct sctp6_sock *newsctp6sk;
 658
 659         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 660         if (!newsk)
 661                 goto out;
 662
 663         sock_init_data(NULL, newsk);
 664
 665         sctp_copy_sock(newsk, sk, asoc);
 666         sock_reset_flag(sk, SOCK_ZAPPED);
 667
 668         newsctp6sk = (struct sctp6_sock *)newsk;
 669         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 670
 671         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 672
 673         newnp = inet6_sk(newsk);
 674
 675         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 676
 677         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 678          * and getpeername().
 679          */
 680         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 681
 682         sk_refcnt_debug_inc(newsk);
 683
 684         if (newsk->sk_prot->init(newsk)) {
 685                 sk_common_release(newsk);
 686                 newsk = NULL;
 687         }
 688
 689 out:
 690         return newsk;
 691 }
 692
 693 /* Map v4 address to mapped v6 address */
 694 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 695 {
 696         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 697                 sctp_v4_map_v6(addr);
 698 }
 699
 700 /* Where did this skb come from?  */
 701 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 702 {
 703         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 704         return opt->iif;
 705 }
 706
 707 /* Was this packet marked by Explicit Congestion Notification? */
 708 static int sctp_v6_is_ce(const struct sk_buff *skb)
 709 {
 710         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 711 }
 712
 713 /* Dump the v6 addr to the seq file. */
 714 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 715 {
 716         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 717 }
 718
 719 static void sctp_v6_ecn_capable(struct sock *sk)
 720 {
 721         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 722 }
 723
 724 /* Initialize a PF_INET6 socket msg_name. */
 725 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 726 {
 727         struct sockaddr_in6 *sin6;
 728
 729         sin6 = (struct sockaddr_in6 *)msgname;
 730         sin6->sin6_family = AF_INET6;
 731         sin6->sin6_flowinfo = 0;
 732         sin6->sin6_scope_id = 0; /*FIXME */
 733         *addr_len = sizeof(struct sockaddr_in6);
 734 }
 735
 736 /* Initialize a PF_INET msgname from a ulpevent. */
 737 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 738                                      char *msgname, int *addrlen)
 739 {
 740         struct sockaddr_in6 *sin6, *sin6from;
 741
 742         if (msgname) {
 743                 union sctp_addr *addr;
 744                 struct sctp_association *asoc;
 745
 746                 asoc = event->asoc;
 747                 sctp_inet6_msgname(msgname, addrlen);
 748                 sin6 = (struct sockaddr_in6 *)msgname;
 749                 sin6->sin6_port = htons(asoc->peer.port);
 750                 addr = &asoc->peer.primary_addr;
 751
 752                 /* Note: If we go to a common v6 format, this code
 753                  * will change.
 754                  */
 755
 756                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 757                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 758                     AF_INET == addr->sa.sa_family) {
 759                         sctp_v4_map_v6((union sctp_addr *)sin6);
 760                         sin6->sin6_addr.s6_addr32[3] =
 761                                 addr->v4.sin_addr.s_addr;
 762                         return;
 763                 }
 764
 765                 sin6from = &asoc->peer.primary_addr.v6;
 766                 sin6->sin6_addr = sin6from->sin6_addr;
 767                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 768                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 769         }
 770 }
 771
 772 /* Initialize a msg_name from an inbound skb. */
 773 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 774                                    int *addr_len)
 775 {
 776         struct sctphdr *sh;
 777         struct sockaddr_in6 *sin6;
 778
 779         if (msgname) {
 780                 sctp_inet6_msgname(msgname, addr_len);
 781                 sin6 = (struct sockaddr_in6 *)msgname;
 782                 sh = sctp_hdr(skb);
 783                 sin6->sin6_port = sh->source;
 784
 785                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 786                 if (sctp_sk(skb->sk)->v4mapped &&
 787                     ip_hdr(skb)->version == 4) {
 788                         sctp_v4_map_v6((union sctp_addr *)sin6);
 789                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 790                         return;
 791                 }
 792
 793                 /* Otherwise, just copy the v6 address. */
 794                 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 795                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 796                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 797                         sin6->sin6_scope_id = ev->iif;
 798                 }
 799         }
 800 }
 801
 802 /* Do we support this AF? */
 803 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 804 {
 805         switch (family) {
 806         case AF_INET6:
 807                 return 1;
 808         /* v4-mapped-v6 addresses */
 809         case AF_INET:
 810                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 811                         return 1;
 812         default:
 813                 return 0;
 814         }
 815 }
 816
 817 /* Address matching with wildcards allowed.  This extra level
 818  * of indirection lets us choose whether a PF_INET6 should
 819  * disallow any v4 addresses if we so choose.
 820  */
 821 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 822                                const union sctp_addr *addr2,
 823                                struct sctp_sock *opt)
 824 {
 825         struct sctp_af *af1, *af2;
 826         struct sock *sk = sctp_opt2sk(opt);
 827
 828         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 829         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 830
 831         if (!af1 || !af2)
 832                 return 0;
 833
 834         /* If the socket is IPv6 only, v4 addrs will not match */
 835         if (__ipv6_only_sock(sk) && af1 != af2)
 836                 return 0;
 837
 838         /* Today, wildcard AF_INET/AF_INET6. */
 839         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 840                 return 1;
 841
 842         if (addr1->sa.sa_family != addr2->sa.sa_family)
 843                 return 0;
 844
 845         return af1->cmp_addr(addr1, addr2);
 846 }
 847
 848 /* Verify that the provided sockaddr looks bindable.   Common verification,
 849  * has already been taken care of.
 850  */
 851 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 852 {
 853         struct sctp_af *af;
 854
 855         /* ASSERT: address family has already been verified. */
 856         if (addr->sa.sa_family != AF_INET6)
 857                 af = sctp_get_af_specific(addr->sa.sa_family);
 858         else {
 859                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 860                 struct net_device *dev;
 861
 862                 if (type & IPV6_ADDR_LINKLOCAL) {
 863                         struct net *net;
 864                         if (!addr->v6.sin6_scope_id)
 865                                 return 0;
 866                         net = sock_net(&opt->inet.sk);
 867                         rcu_read_lock();
 868                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 869                         if (!dev ||
 870                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 871                                 rcu_read_unlock();
 872                                 return 0;
 873                         }
 874                         rcu_read_unlock();
 875                 } else if (type == IPV6_ADDR_MAPPED) {
 876                         if (!opt->v4mapped)
 877                                 return 0;
 878                 }
 879
 880                 af = opt->pf->af;
 881         }
 882         return af->available(addr, opt);
 883 }
 884
 885 /* Verify that the provided sockaddr looks sendable.   Common verification,
 886  * has already been taken care of.
 887  */
 888 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 889 {
 890         struct sctp_af *af = NULL;
 891
 892         /* ASSERT: address family has already been verified. */
 893         if (addr->sa.sa_family != AF_INET6)
 894                 af = sctp_get_af_specific(addr->sa.sa_family);
 895         else {
 896                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 897                 struct net_device *dev;
 898
 899                 if (type & IPV6_ADDR_LINKLOCAL) {
 900                         if (!addr->v6.sin6_scope_id)
 901                                 return 0;
 902                         rcu_read_lock();
 903                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 904                                                    addr->v6.sin6_scope_id);
 905                         rcu_read_unlock();
 906                         if (!dev)
 907                                 return 0;
 908                 }
 909                 af = opt->pf->af;
 910         }
 911
 912         return af != NULL;
 913 }
 914
 915 /* Fill in Supported Address Type information for INIT and INIT-ACK
 916  * chunks.   Note: In the future, we may want to look at sock options
 917  * to determine whether a PF_INET6 socket really wants to have IPV4
 918  * addresses.
 919  * Returns number of addresses supported.
 920  */
 921 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 922                                       __be16 *types)
 923 {
 924         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 925         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 926                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 927                 return 2;
 928         }
 929         return 1;
 930 }
 931
 932 static const struct proto_ops inet6_seqpacket_ops = {
 933         .family            = PF_INET6,
 934         .owner             = THIS_MODULE,
 935         .release           = inet6_release,
 936         .bind              = inet6_bind,
 937         .connect           = inet_dgram_connect,
 938         .socketpair        = sock_no_socketpair,
 939         .accept            = inet_accept,
 940         .getname           = inet6_getname,
 941         .poll              = sctp_poll,
 942         .ioctl             = inet6_ioctl,
 943         .listen            = sctp_inet_listen,
 944         .shutdown          = inet_shutdown,
 945         .setsockopt        = sock_common_setsockopt,
 946         .getsockopt        = sock_common_getsockopt,
 947         .sendmsg           = inet_sendmsg,
 948         .recvmsg           = sock_common_recvmsg,
 949         .mmap              = sock_no_mmap,
 950 #ifdef CONFIG_COMPAT
 951         .compat_setsockopt = compat_sock_common_setsockopt,
 952         .compat_getsockopt = compat_sock_common_getsockopt,
 953 #endif
 954 };
 955
 956 static struct inet_protosw sctpv6_seqpacket_protosw = {
 957         .type          = SOCK_SEQPACKET,
 958         .protocol      = IPPROTO_SCTP,
 959         .prot          = &sctpv6_prot,
 960         .ops           = &inet6_seqpacket_ops,
 961         .no_check      = 0,
 962         .flags         = SCTP_PROTOSW_FLAG
 963 };
 964 static struct inet_protosw sctpv6_stream_protosw = {
 965         .type          = SOCK_STREAM,
 966         .protocol      = IPPROTO_SCTP,
 967         .prot          = &sctpv6_prot,
 968         .ops           = &inet6_seqpacket_ops,
 969         .no_check      = 0,
 970         .flags         = SCTP_PROTOSW_FLAG,
 971 };
 972
 973 static int sctp6_rcv(struct sk_buff *skb)
 974 {
 975         return sctp_rcv(skb) ? -1 : 0;
 976 }
 977
 978 static const struct inet6_protocol sctpv6_protocol = {
 979         .handler      = sctp6_rcv,
 980         .err_handler  = sctp_v6_err,
 981         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 982 };
 983
 984 static struct sctp_af sctp_af_inet6 = {
 985         .sa_family         = AF_INET6,
 986         .sctp_xmit         = sctp_v6_xmit,
 987         .setsockopt        = ipv6_setsockopt,
 988         .getsockopt        = ipv6_getsockopt,
 989         .get_dst           = sctp_v6_get_dst,
 990         .get_saddr         = sctp_v6_get_saddr,
 991         .copy_addrlist     = sctp_v6_copy_addrlist,
 992         .from_skb          = sctp_v6_from_skb,
 993         .from_sk           = sctp_v6_from_sk,
 994         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 995         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 996         .from_addr_param   = sctp_v6_from_addr_param,
 997         .to_addr_param     = sctp_v6_to_addr_param,
 998         .cmp_addr          = sctp_v6_cmp_addr,
 999         .scope             = sctp_v6_scope,
1000         .addr_valid        = sctp_v6_addr_valid,
1001         .inaddr_any        = sctp_v6_inaddr_any,
1002         .is_any            = sctp_v6_is_any,
1003         .available         = sctp_v6_available,
1004         .skb_iif           = sctp_v6_skb_iif,
1005         .is_ce             = sctp_v6_is_ce,
1006         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1007         .ecn_capable       = sctp_v6_ecn_capable,
1008         .net_header_len    = sizeof(struct ipv6hdr),
1009         .sockaddr_len      = sizeof(struct sockaddr_in6),
1010 #ifdef CONFIG_COMPAT
1011         .compat_setsockopt = compat_ipv6_setsockopt,
1012         .compat_getsockopt = compat_ipv6_getsockopt,
1013 #endif
1014 };
1015
1016 static struct sctp_pf sctp_pf_inet6 = {
1017         .event_msgname = sctp_inet6_event_msgname,
1018         .skb_msgname   = sctp_inet6_skb_msgname,
1019         .af_supported  = sctp_inet6_af_supported,
1020         .cmp_addr      = sctp_inet6_cmp_addr,
1021         .bind_verify   = sctp_inet6_bind_verify,
1022         .send_verify   = sctp_inet6_send_verify,
1023         .supported_addrs = sctp_inet6_supported_addrs,
1024         .create_accept_sk = sctp_v6_create_accept_sk,
1025         .addr_v4map    = sctp_v6_addr_v4map,
1026         .af            = &sctp_af_inet6,
1027 };
1028
1029 /* Initialize IPv6 support and register with socket layer.  */
1030 void sctp_v6_pf_init(void)
1031 {
1032         /* Register the SCTP specific PF_INET6 functions. */
1033         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1034
1035         /* Register the SCTP specific AF_INET6 functions. */
1036         sctp_register_af(&sctp_af_inet6);
1037 }
1038
1039 void sctp_v6_pf_exit(void)
1040 {
1041         list_del(&sctp_af_inet6.list);
1042 }
1043
1044 /* Initialize IPv6 support and register with socket layer.  */
1045 int sctp_v6_protosw_init(void)
1046 {
1047         int rc;
1048
1049         rc = proto_register(&sctpv6_prot, 1);
1050         if (rc)
1051                 return rc;
1052
1053         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1054         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1055         inet6_register_protosw(&sctpv6_stream_protosw);
1056
1057         return 0;
1058 }
1059
1060 void sctp_v6_protosw_exit(void)
1061 {
1062         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1063         inet6_unregister_protosw(&sctpv6_stream_protosw);
1064         proto_unregister(&sctpv6_prot);
1065 }
1066
1067
1068 /* Register with inet6 layer. */
1069 int sctp_v6_add_protocol(void)
1070 {
1071         /* Register notifier for inet6 address additions/deletions. */
1072         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1073
1074         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1075                 return -EAGAIN;
1076
1077         return 0;
1078 }
1079
1080 /* Unregister with inet6 layer. */
1081 void sctp_v6_del_protocol(void)
1082 {
1083         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1084         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1085 }