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                 goto out_unlock;
 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 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 214 {
 215         struct sock *sk = skb->sk;
 216         struct ipv6_pinfo *np = inet6_sk(sk);
 217         struct flowi6 *fl6 = &transport->fl.u.ip6;
 218
 219         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 220                           __func__, skb, skb->len,
 221                           &fl6->saddr, &fl6->daddr);
 222
 223         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 224
 225         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 226                 skb->local_df = 1;
 227
 228         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 229
 230         return ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 231 }
 232
 233 /* Returns the dst cache entry for the given source and destination ip
 234  * addresses.
 235  */
 236 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 237                             struct flowi *fl, struct sock *sk)
 238 {
 239         struct sctp_association *asoc = t->asoc;
 240         struct dst_entry *dst = NULL;
 241         struct flowi6 *fl6 = &fl->u.ip6;
 242         struct sctp_bind_addr *bp;
 243         struct ipv6_pinfo *np = inet6_sk(sk);
 244         struct sctp_sockaddr_entry *laddr;
 245         union sctp_addr *baddr = NULL;
 246         union sctp_addr *daddr = &t->ipaddr;
 247         union sctp_addr dst_saddr;
 248         struct in6_addr *final_p, final;
 249         __u8 matchlen = 0;
 250         __u8 bmatchlen;
 251         sctp_scope_t scope;
 252
 253         memset(fl6, 0, sizeof(struct flowi6));
 254         fl6->daddr = daddr->v6.sin6_addr;
 255         fl6->fl6_dport = daddr->v6.sin6_port;
 256         fl6->flowi6_proto = IPPROTO_SCTP;
 257         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 258                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 259
 260         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 261
 262         if (asoc)
 263                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 264
 265         if (saddr) {
 266                 fl6->saddr = saddr->v6.sin6_addr;
 267                 fl6->fl6_sport = saddr->v6.sin6_port;
 268                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
 269         }
 270
 271         final_p = fl6_update_dst(fl6, np->opt, &final);
 272         dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
 273         if (!asoc || saddr)
 274                 goto out;
 275
 276         bp = &asoc->base.bind_addr;
 277         scope = sctp_scope(daddr);
 278         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 279          * to see if we can use it.
 280          */
 281         if (!IS_ERR(dst)) {
 282                 /* Walk through the bind address list and look for a bind
 283                  * address that matches the source address of the returned dst.
 284                  */
 285                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 286                 rcu_read_lock();
 287                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 288                         if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
 289                                 continue;
 290
 291                         /* Do not compare against v4 addrs */
 292                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 293                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 294                                 rcu_read_unlock();
 295                                 goto out;
 296                         }
 297                 }
 298                 rcu_read_unlock();
 299                 /* None of the bound addresses match the source address of the
 300                  * dst. So release it.
 301                  */
 302                 dst_release(dst);
 303                 dst = NULL;
 304         }
 305
 306         /* Walk through the bind address list and try to get the
 307          * best source address for a given destination.
 308          */
 309         rcu_read_lock();
 310         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 311                 if (!laddr->valid)
 312                         continue;
 313                 if ((laddr->state == SCTP_ADDR_SRC) &&
 314                     (laddr->a.sa.sa_family == AF_INET6) &&
 315                     (scope <= sctp_scope(&laddr->a))) {
 316                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 317                         if (!baddr || (matchlen < bmatchlen)) {
 318                                 baddr = &laddr->a;
 319                                 matchlen = bmatchlen;
 320                         }
 321                 }
 322         }
 323         rcu_read_unlock();
 324
 325         if (baddr) {
 326                 fl6->saddr = baddr->v6.sin6_addr;
 327                 fl6->fl6_sport = baddr->v6.sin6_port;
 328                 final_p = fl6_update_dst(fl6, np->opt, &final);
 329                 dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
 330         }
 331
 332 out:
 333         if (!IS_ERR_OR_NULL(dst)) {
 334                 struct rt6_info *rt;
 335                 rt = (struct rt6_info *)dst;
 336                 t->dst = dst;
 337                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 338                         &rt->rt6i_dst.addr, &fl6->saddr);
 339         } else {
 340                 t->dst = NULL;
 341                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
 342         }
 343 }
 344
 345 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 346  * addresses.
 347  */
 348 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 349                                          union sctp_addr *s2)
 350 {
 351         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 352 }
 353
 354 /* Fills in the source address(saddr) based on the destination address(daddr)
 355  * and asoc's bind address list.
 356  */
 357 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 358                               struct sctp_transport *t,
 359                               struct flowi *fl)
 360 {
 361         struct flowi6 *fl6 = &fl->u.ip6;
 362         union sctp_addr *saddr = &t->saddr;
 363
 364         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 365
 366         if (t->dst) {
 367                 saddr->v6.sin6_family = AF_INET6;
 368                 saddr->v6.sin6_addr = fl6->saddr;
 369         }
 370 }
 371
 372 /* Make a copy of all potential local addresses. */
 373 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 374                                   struct net_device *dev)
 375 {
 376         struct inet6_dev *in6_dev;
 377         struct inet6_ifaddr *ifp;
 378         struct sctp_sockaddr_entry *addr;
 379
 380         rcu_read_lock();
 381         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 382                 rcu_read_unlock();
 383                 return;
 384         }
 385
 386         read_lock_bh(&in6_dev->lock);
 387         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 388                 /* Add the address to the local list.  */
 389                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 390                 if (addr) {
 391                         addr->a.v6.sin6_family = AF_INET6;
 392                         addr->a.v6.sin6_port = 0;
 393                         addr->a.v6.sin6_addr = ifp->addr;
 394                         addr->a.v6.sin6_scope_id = dev->ifindex;
 395                         addr->valid = 1;
 396                         INIT_LIST_HEAD(&addr->list);
 397                         list_add_tail(&addr->list, addrlist);
 398                 }
 399         }
 400
 401         read_unlock_bh(&in6_dev->lock);
 402         rcu_read_unlock();
 403 }
 404
 405 /* Initialize a sockaddr_storage from in incoming skb. */
 406 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 407                              int is_saddr)
 408 {
 409         __be16 *port;
 410         struct sctphdr *sh;
 411
 412         port = &addr->v6.sin6_port;
 413         addr->v6.sin6_family = AF_INET6;
 414         addr->v6.sin6_flowinfo = 0; /* FIXME */
 415         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 416
 417         sh = sctp_hdr(skb);
 418         if (is_saddr) {
 419                 *port  = sh->source;
 420                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 421         } else {
 422                 *port = sh->dest;
 423                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 424         }
 425 }
 426
 427 /* Initialize an sctp_addr from a socket. */
 428 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 429 {
 430         addr->v6.sin6_family = AF_INET6;
 431         addr->v6.sin6_port = 0;
 432         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 433 }
 434
 435 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 436 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 437 {
 438         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 439                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 440                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 441                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 442                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 443                         addr->v4.sin_addr.s_addr;
 444         } else {
 445                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 446         }
 447 }
 448
 449 /* Initialize sk->sk_daddr from sctp_addr. */
 450 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 451 {
 452         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 453                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 454                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 455                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 456                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 457         } else {
 458                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 459         }
 460 }
 461
 462 /* Initialize a sctp_addr from an address parameter. */
 463 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 464                                     union sctp_addr_param *param,
 465                                     __be16 port, int iif)
 466 {
 467         addr->v6.sin6_family = AF_INET6;
 468         addr->v6.sin6_port = port;
 469         addr->v6.sin6_flowinfo = 0; /* BUG */
 470         addr->v6.sin6_addr = param->v6.addr;
 471         addr->v6.sin6_scope_id = iif;
 472 }
 473
 474 /* Initialize an address parameter from a sctp_addr and return the length
 475  * of the address parameter.
 476  */
 477 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 478                                  union sctp_addr_param *param)
 479 {
 480         int length = sizeof(sctp_ipv6addr_param_t);
 481
 482         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 483         param->v6.param_hdr.length = htons(length);
 484         param->v6.addr = addr->v6.sin6_addr;
 485
 486         return length;
 487 }
 488
 489 /* Initialize a sctp_addr from struct in6_addr. */
 490 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 491                               __be16 port)
 492 {
 493         addr->sa.sa_family = AF_INET6;
 494         addr->v6.sin6_port = port;
 495         addr->v6.sin6_addr = *saddr;
 496 }
 497
 498 /* Compare addresses exactly.
 499  * v4-mapped-v6 is also in consideration.
 500  */
 501 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 502                             const union sctp_addr *addr2)
 503 {
 504         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 505                 if (addr1->sa.sa_family == AF_INET &&
 506                     addr2->sa.sa_family == AF_INET6 &&
 507                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 508                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 509                             addr2->v6.sin6_addr.s6_addr32[3] ==
 510                             addr1->v4.sin_addr.s_addr)
 511                                 return 1;
 512                 }
 513                 if (addr2->sa.sa_family == AF_INET &&
 514                     addr1->sa.sa_family == AF_INET6 &&
 515                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 516                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 517                             addr1->v6.sin6_addr.s6_addr32[3] ==
 518                             addr2->v4.sin_addr.s_addr)
 519                                 return 1;
 520                 }
 521                 return 0;
 522         }
 523         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 524                 return 0;
 525         /* If this is a linklocal address, compare the scope_id. */
 526         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 527                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 528                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 529                         return 0;
 530                 }
 531         }
 532
 533         return 1;
 534 }
 535
 536 /* Initialize addr struct to INADDR_ANY. */
 537 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 538 {
 539         memset(addr, 0x00, sizeof(union sctp_addr));
 540         addr->v6.sin6_family = AF_INET6;
 541         addr->v6.sin6_port = port;
 542 }
 543
 544 /* Is this a wildcard address? */
 545 static int sctp_v6_is_any(const union sctp_addr *addr)
 546 {
 547         return ipv6_addr_any(&addr->v6.sin6_addr);
 548 }
 549
 550 /* Should this be available for binding?   */
 551 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 552 {
 553         int type;
 554         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 555
 556         type = ipv6_addr_type(in6);
 557         if (IPV6_ADDR_ANY == type)
 558                 return 1;
 559         if (type == IPV6_ADDR_MAPPED) {
 560                 if (sp && !sp->v4mapped)
 561                         return 0;
 562                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 563                         return 0;
 564                 sctp_v6_map_v4(addr);
 565                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 566         }
 567         if (!(type & IPV6_ADDR_UNICAST))
 568                 return 0;
 569
 570         return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
 571 }
 572
 573 /* This function checks if the address is a valid address to be used for
 574  * SCTP.
 575  *
 576  * Output:
 577  * Return 0 - If the address is a non-unicast or an illegal address.
 578  * Return 1 - If the address is a unicast.
 579  */
 580 static int sctp_v6_addr_valid(union sctp_addr *addr,
 581                               struct sctp_sock *sp,
 582                               const struct sk_buff *skb)
 583 {
 584         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 585
 586         /* Support v4-mapped-v6 address. */
 587         if (ret == IPV6_ADDR_MAPPED) {
 588                 /* Note: This routine is used in input, so v4-mapped-v6
 589                  * are disallowed here when there is no sctp_sock.
 590                  */
 591                 if (!sp || !sp->v4mapped)
 592                         return 0;
 593                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 594                         return 0;
 595                 sctp_v6_map_v4(addr);
 596                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 597         }
 598
 599         /* Is this a non-unicast address */
 600         if (!(ret & IPV6_ADDR_UNICAST))
 601                 return 0;
 602
 603         return 1;
 604 }
 605
 606 /* What is the scope of 'addr'?  */
 607 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 608 {
 609         int v6scope;
 610         sctp_scope_t retval;
 611
 612         /* The IPv6 scope is really a set of bit fields.
 613          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 614          */
 615
 616         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 617         switch (v6scope) {
 618         case IFA_HOST:
 619                 retval = SCTP_SCOPE_LOOPBACK;
 620                 break;
 621         case IFA_LINK:
 622                 retval = SCTP_SCOPE_LINK;
 623                 break;
 624         case IFA_SITE:
 625                 retval = SCTP_SCOPE_PRIVATE;
 626                 break;
 627         default:
 628                 retval = SCTP_SCOPE_GLOBAL;
 629                 break;
 630         }
 631
 632         return retval;
 633 }
 634
 635 /* Create and initialize a new sk for the socket to be returned by accept(). */
 636 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 637                                              struct sctp_association *asoc)
 638 {
 639         struct sock *newsk;
 640         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 641         struct sctp6_sock *newsctp6sk;
 642
 643         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 644         if (!newsk)
 645                 goto out;
 646
 647         sock_init_data(NULL, newsk);
 648
 649         sctp_copy_sock(newsk, sk, asoc);
 650         sock_reset_flag(sk, SOCK_ZAPPED);
 651
 652         newsctp6sk = (struct sctp6_sock *)newsk;
 653         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 654
 655         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 656
 657         newnp = inet6_sk(newsk);
 658
 659         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 660
 661         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 662          * and getpeername().
 663          */
 664         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 665
 666         sk_refcnt_debug_inc(newsk);
 667
 668         if (newsk->sk_prot->init(newsk)) {
 669                 sk_common_release(newsk);
 670                 newsk = NULL;
 671         }
 672
 673 out:
 674         return newsk;
 675 }
 676
 677 /* Map v4 address to mapped v6 address */
 678 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 679 {
 680         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 681                 sctp_v4_map_v6(addr);
 682 }
 683
 684 /* Where did this skb come from?  */
 685 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 686 {
 687         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 688         return opt->iif;
 689 }
 690
 691 /* Was this packet marked by Explicit Congestion Notification? */
 692 static int sctp_v6_is_ce(const struct sk_buff *skb)
 693 {
 694         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 695 }
 696
 697 /* Dump the v6 addr to the seq file. */
 698 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 699 {
 700         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 701 }
 702
 703 static void sctp_v6_ecn_capable(struct sock *sk)
 704 {
 705         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 706 }
 707
 708 /* Initialize a PF_INET6 socket msg_name. */
 709 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 710 {
 711         struct sockaddr_in6 *sin6;
 712
 713         sin6 = (struct sockaddr_in6 *)msgname;
 714         sin6->sin6_family = AF_INET6;
 715         sin6->sin6_flowinfo = 0;
 716         sin6->sin6_scope_id = 0; /*FIXME */
 717         *addr_len = sizeof(struct sockaddr_in6);
 718 }
 719
 720 /* Initialize a PF_INET msgname from a ulpevent. */
 721 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 722                                      char *msgname, int *addrlen)
 723 {
 724         struct sockaddr_in6 *sin6, *sin6from;
 725
 726         if (msgname) {
 727                 union sctp_addr *addr;
 728                 struct sctp_association *asoc;
 729
 730                 asoc = event->asoc;
 731                 sctp_inet6_msgname(msgname, addrlen);
 732                 sin6 = (struct sockaddr_in6 *)msgname;
 733                 sin6->sin6_port = htons(asoc->peer.port);
 734                 addr = &asoc->peer.primary_addr;
 735
 736                 /* Note: If we go to a common v6 format, this code
 737                  * will change.
 738                  */
 739
 740                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 741                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 742                     AF_INET == addr->sa.sa_family) {
 743                         sctp_v4_map_v6((union sctp_addr *)sin6);
 744                         sin6->sin6_addr.s6_addr32[3] =
 745                                 addr->v4.sin_addr.s_addr;
 746                         return;
 747                 }
 748
 749                 sin6from = &asoc->peer.primary_addr.v6;
 750                 sin6->sin6_addr = sin6from->sin6_addr;
 751                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 752                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 753         }
 754 }
 755
 756 /* Initialize a msg_name from an inbound skb. */
 757 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 758                                    int *addr_len)
 759 {
 760         struct sctphdr *sh;
 761         struct sockaddr_in6 *sin6;
 762
 763         if (msgname) {
 764                 sctp_inet6_msgname(msgname, addr_len);
 765                 sin6 = (struct sockaddr_in6 *)msgname;
 766                 sh = sctp_hdr(skb);
 767                 sin6->sin6_port = sh->source;
 768
 769                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 770                 if (sctp_sk(skb->sk)->v4mapped &&
 771                     ip_hdr(skb)->version == 4) {
 772                         sctp_v4_map_v6((union sctp_addr *)sin6);
 773                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 774                         return;
 775                 }
 776
 777                 /* Otherwise, just copy the v6 address. */
 778                 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 779                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 780                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 781                         sin6->sin6_scope_id = ev->iif;
 782                 }
 783         }
 784 }
 785
 786 /* Do we support this AF? */
 787 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 788 {
 789         switch (family) {
 790         case AF_INET6:
 791                 return 1;
 792         /* v4-mapped-v6 addresses */
 793         case AF_INET:
 794                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 795                         return 1;
 796         default:
 797                 return 0;
 798         }
 799 }
 800
 801 /* Address matching with wildcards allowed.  This extra level
 802  * of indirection lets us choose whether a PF_INET6 should
 803  * disallow any v4 addresses if we so choose.
 804  */
 805 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 806                                const union sctp_addr *addr2,
 807                                struct sctp_sock *opt)
 808 {
 809         struct sctp_af *af1, *af2;
 810         struct sock *sk = sctp_opt2sk(opt);
 811
 812         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 813         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 814
 815         if (!af1 || !af2)
 816                 return 0;
 817
 818         /* If the socket is IPv6 only, v4 addrs will not match */
 819         if (__ipv6_only_sock(sk) && af1 != af2)
 820                 return 0;
 821
 822         /* Today, wildcard AF_INET/AF_INET6. */
 823         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 824                 return 1;
 825
 826         if (addr1->sa.sa_family != addr2->sa.sa_family)
 827                 return 0;
 828
 829         return af1->cmp_addr(addr1, addr2);
 830 }
 831
 832 /* Verify that the provided sockaddr looks bindable.   Common verification,
 833  * has already been taken care of.
 834  */
 835 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 836 {
 837         struct sctp_af *af;
 838
 839         /* ASSERT: address family has already been verified. */
 840         if (addr->sa.sa_family != AF_INET6)
 841                 af = sctp_get_af_specific(addr->sa.sa_family);
 842         else {
 843                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 844                 struct net_device *dev;
 845
 846                 if (type & IPV6_ADDR_LINKLOCAL) {
 847                         struct net *net;
 848                         if (!addr->v6.sin6_scope_id)
 849                                 return 0;
 850                         net = sock_net(&opt->inet.sk);
 851                         rcu_read_lock();
 852                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 853                         if (!dev ||
 854                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 855                                 rcu_read_unlock();
 856                                 return 0;
 857                         }
 858                         rcu_read_unlock();
 859                 } else if (type == IPV6_ADDR_MAPPED) {
 860                         if (!opt->v4mapped)
 861                                 return 0;
 862                 }
 863
 864                 af = opt->pf->af;
 865         }
 866         return af->available(addr, opt);
 867 }
 868
 869 /* Verify that the provided sockaddr looks sendable.   Common verification,
 870  * has already been taken care of.
 871  */
 872 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 873 {
 874         struct sctp_af *af = NULL;
 875
 876         /* ASSERT: address family has already been verified. */
 877         if (addr->sa.sa_family != AF_INET6)
 878                 af = sctp_get_af_specific(addr->sa.sa_family);
 879         else {
 880                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 881                 struct net_device *dev;
 882
 883                 if (type & IPV6_ADDR_LINKLOCAL) {
 884                         if (!addr->v6.sin6_scope_id)
 885                                 return 0;
 886                         rcu_read_lock();
 887                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 888                                                    addr->v6.sin6_scope_id);
 889                         rcu_read_unlock();
 890                         if (!dev)
 891                                 return 0;
 892                 }
 893                 af = opt->pf->af;
 894         }
 895
 896         return af != NULL;
 897 }
 898
 899 /* Fill in Supported Address Type information for INIT and INIT-ACK
 900  * chunks.   Note: In the future, we may want to look at sock options
 901  * to determine whether a PF_INET6 socket really wants to have IPV4
 902  * addresses.
 903  * Returns number of addresses supported.
 904  */
 905 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 906                                       __be16 *types)
 907 {
 908         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 909         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 910                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 911                 return 2;
 912         }
 913         return 1;
 914 }
 915
 916 static const struct proto_ops inet6_seqpacket_ops = {
 917         .family            = PF_INET6,
 918         .owner             = THIS_MODULE,
 919         .release           = inet6_release,
 920         .bind              = inet6_bind,
 921         .connect           = inet_dgram_connect,
 922         .socketpair        = sock_no_socketpair,
 923         .accept            = inet_accept,
 924         .getname           = inet6_getname,
 925         .poll              = sctp_poll,
 926         .ioctl             = inet6_ioctl,
 927         .listen            = sctp_inet_listen,
 928         .shutdown          = inet_shutdown,
 929         .setsockopt        = sock_common_setsockopt,
 930         .getsockopt        = sock_common_getsockopt,
 931         .sendmsg           = inet_sendmsg,
 932         .recvmsg           = sock_common_recvmsg,
 933         .mmap              = sock_no_mmap,
 934 #ifdef CONFIG_COMPAT
 935         .compat_setsockopt = compat_sock_common_setsockopt,
 936         .compat_getsockopt = compat_sock_common_getsockopt,
 937 #endif
 938 };
 939
 940 static struct inet_protosw sctpv6_seqpacket_protosw = {
 941         .type          = SOCK_SEQPACKET,
 942         .protocol      = IPPROTO_SCTP,
 943         .prot          = &sctpv6_prot,
 944         .ops           = &inet6_seqpacket_ops,
 945         .no_check      = 0,
 946         .flags         = SCTP_PROTOSW_FLAG
 947 };
 948 static struct inet_protosw sctpv6_stream_protosw = {
 949         .type          = SOCK_STREAM,
 950         .protocol      = IPPROTO_SCTP,
 951         .prot          = &sctpv6_prot,
 952         .ops           = &inet6_seqpacket_ops,
 953         .no_check      = 0,
 954         .flags         = SCTP_PROTOSW_FLAG,
 955 };
 956
 957 static int sctp6_rcv(struct sk_buff *skb)
 958 {
 959         return sctp_rcv(skb) ? -1 : 0;
 960 }
 961
 962 static const struct inet6_protocol sctpv6_protocol = {
 963         .handler      = sctp6_rcv,
 964         .err_handler  = sctp_v6_err,
 965         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 966 };
 967
 968 static struct sctp_af sctp_af_inet6 = {
 969         .sa_family         = AF_INET6,
 970         .sctp_xmit         = sctp_v6_xmit,
 971         .setsockopt        = ipv6_setsockopt,
 972         .getsockopt        = ipv6_getsockopt,
 973         .get_dst           = sctp_v6_get_dst,
 974         .get_saddr         = sctp_v6_get_saddr,
 975         .copy_addrlist     = sctp_v6_copy_addrlist,
 976         .from_skb          = sctp_v6_from_skb,
 977         .from_sk           = sctp_v6_from_sk,
 978         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 979         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 980         .from_addr_param   = sctp_v6_from_addr_param,
 981         .to_addr_param     = sctp_v6_to_addr_param,
 982         .cmp_addr          = sctp_v6_cmp_addr,
 983         .scope             = sctp_v6_scope,
 984         .addr_valid        = sctp_v6_addr_valid,
 985         .inaddr_any        = sctp_v6_inaddr_any,
 986         .is_any            = sctp_v6_is_any,
 987         .available         = sctp_v6_available,
 988         .skb_iif           = sctp_v6_skb_iif,
 989         .is_ce             = sctp_v6_is_ce,
 990         .seq_dump_addr     = sctp_v6_seq_dump_addr,
 991         .ecn_capable       = sctp_v6_ecn_capable,
 992         .net_header_len    = sizeof(struct ipv6hdr),
 993         .sockaddr_len      = sizeof(struct sockaddr_in6),
 994 #ifdef CONFIG_COMPAT
 995         .compat_setsockopt = compat_ipv6_setsockopt,
 996         .compat_getsockopt = compat_ipv6_getsockopt,
 997 #endif
 998 };
 999
1000 static struct sctp_pf sctp_pf_inet6 = {
1001         .event_msgname = sctp_inet6_event_msgname,
1002         .skb_msgname   = sctp_inet6_skb_msgname,
1003         .af_supported  = sctp_inet6_af_supported,
1004         .cmp_addr      = sctp_inet6_cmp_addr,
1005         .bind_verify   = sctp_inet6_bind_verify,
1006         .send_verify   = sctp_inet6_send_verify,
1007         .supported_addrs = sctp_inet6_supported_addrs,
1008         .create_accept_sk = sctp_v6_create_accept_sk,
1009         .addr_v4map    = sctp_v6_addr_v4map,
1010         .af            = &sctp_af_inet6,
1011 };
1012
1013 /* Initialize IPv6 support and register with socket layer.  */
1014 void sctp_v6_pf_init(void)
1015 {
1016         /* Register the SCTP specific PF_INET6 functions. */
1017         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1018
1019         /* Register the SCTP specific AF_INET6 functions. */
1020         sctp_register_af(&sctp_af_inet6);
1021 }
1022
1023 void sctp_v6_pf_exit(void)
1024 {
1025         list_del(&sctp_af_inet6.list);
1026 }
1027
1028 /* Initialize IPv6 support and register with socket layer.  */
1029 int sctp_v6_protosw_init(void)
1030 {
1031         int rc;
1032
1033         rc = proto_register(&sctpv6_prot, 1);
1034         if (rc)
1035                 return rc;
1036
1037         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1038         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1039         inet6_register_protosw(&sctpv6_stream_protosw);
1040
1041         return 0;
1042 }
1043
1044 void sctp_v6_protosw_exit(void)
1045 {
1046         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1047         inet6_unregister_protosw(&sctpv6_stream_protosw);
1048         proto_unregister(&sctpv6_prot);
1049 }
1050
1051
1052 /* Register with inet6 layer. */
1053 int sctp_v6_add_protocol(void)
1054 {
1055         /* Register notifier for inet6 address additions/deletions. */
1056         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1057
1058         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1059                 return -EAGAIN;
1060
1061         return 0;
1062 }
1063
1064 /* Unregister with inet6 layer. */
1065 void sctp_v6_del_protocol(void)
1066 {
1067         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1068         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1069 }