net/sctp/ipv6.c

   1 /* SCTP kernel reference 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 reference Implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * The SCTP reference 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  * The SCTP reference 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 #include <linux/module.h>
  51 #include <linux/errno.h>
  52 #include <linux/types.h>
  53 #include <linux/socket.h>
  54 #include <linux/sockios.h>
  55 #include <linux/net.h>
  56 #include <linux/in.h>
  57 #include <linux/in6.h>
  58 #include <linux/netdevice.h>
  59 #include <linux/init.h>
  60 #include <linux/ipsec.h>
  61
  62 #include <linux/ipv6.h>
  63 #include <linux/icmpv6.h>
  64 #include <linux/random.h>
  65 #include <linux/seq_file.h>
  66
  67 #include <net/protocol.h>
  68 #include <net/ndisc.h>
  69 #include <net/ip.h>
  70 #include <net/ipv6.h>
  71 #include <net/transp_v6.h>
  72 #include <net/addrconf.h>
  73 #include <net/ip6_route.h>
  74 #include <net/inet_common.h>
  75 #include <net/inet_ecn.h>
  76 #include <net/sctp/sctp.h>
  77
  78 #include <asm/uaccess.h>
  79
  80 /* Event handler for inet6 address addition/deletion events.  */
  81 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  82                                 void *ptr)
  83 {
  84         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  85         struct sctp_sockaddr_entry *addr;
  86         struct list_head *pos, *temp;
  87
  88         switch (ev) {
  89         case NETDEV_UP:
  90                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  91                 if (addr) {
  92                         addr->a.v6.sin6_family = AF_INET6;
  93                         addr->a.v6.sin6_port = 0;
  94                         memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
  95                                  sizeof(struct in6_addr));
  96                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
  97                         list_add_tail(&addr->list, &sctp_local_addr_list);
  98                 }
  99                 break;
 100         case NETDEV_DOWN:
 101                 list_for_each_safe(pos, temp, &sctp_local_addr_list) {
 102                         addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 103                         if (ipv6_addr_equal(&addr->a.v6.sin6_addr, &ifa->addr)) {
 104                                 list_del(pos);
 105                                 kfree(addr);
 106                                 break;
 107                         }
 108                 }
 109
 110                 break;
 111         }
 112
 113         return NOTIFY_DONE;
 114 }
 115
 116 static struct notifier_block sctp_inet6addr_notifier = {
 117         .notifier_call = sctp_inet6addr_event,
 118 };
 119
 120 /* ICMP error handler. */
 121 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 122                              int type, int code, int offset, __be32 info)
 123 {
 124         struct inet6_dev *idev;
 125         struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
 126         struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
 127         struct sock *sk;
 128         struct sctp_association *asoc;
 129         struct sctp_transport *transport;
 130         struct ipv6_pinfo *np;
 131         char *saveip, *savesctp;
 132         int err;
 133
 134         idev = in6_dev_get(skb->dev);
 135
 136         /* Fix up skb to look at the embedded net header. */
 137         saveip = skb->nh.raw;
 138         savesctp  = skb->h.raw;
 139         skb->nh.ipv6h = iph;
 140         skb->h.raw = (char *)sh;
 141         sk = sctp_err_lookup(AF_INET6, skb, sh, &asoc, &transport);
 142         /* Put back, the original pointers. */
 143         skb->nh.raw = saveip;
 144         skb->h.raw = savesctp;
 145         if (!sk) {
 146                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 147                 goto out;
 148         }
 149
 150         /* Warning:  The sock lock is held.  Remember to call
 151          * sctp_err_finish!
 152          */
 153
 154         switch (type) {
 155         case ICMPV6_PKT_TOOBIG:
 156                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 157                 goto out_unlock;
 158         case ICMPV6_PARAMPROB:
 159                 if (ICMPV6_UNK_NEXTHDR == code) {
 160                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 161                         goto out_unlock;
 162                 }
 163                 break;
 164         default:
 165                 break;
 166         }
 167
 168         np = inet6_sk(sk);
 169         icmpv6_err_convert(type, code, &err);
 170         if (!sock_owned_by_user(sk) && np->recverr) {
 171                 sk->sk_err = err;
 172                 sk->sk_error_report(sk);
 173         } else {  /* Only an error on timeout */
 174                 sk->sk_err_soft = err;
 175         }
 176
 177 out_unlock:
 178         sctp_err_finish(sk, asoc);
 179 out:
 180         if (likely(idev != NULL))
 181                 in6_dev_put(idev);
 182 }
 183
 184 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 185 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
 186                         int ipfragok)
 187 {
 188         struct sock *sk = skb->sk;
 189         struct ipv6_pinfo *np = inet6_sk(sk);
 190         struct flowi fl;
 191
 192         memset(&fl, 0, sizeof(fl));
 193
 194         fl.proto = sk->sk_protocol;
 195
 196         /* Fill in the dest address from the route entry passed with the skb
 197          * and the source address from the transport.
 198          */
 199         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 200         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 201
 202         fl.fl6_flowlabel = np->flow_label;
 203         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 204         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 205                 fl.oif = transport->saddr.v6.sin6_scope_id;
 206         else
 207                 fl.oif = sk->sk_bound_dev_if;
 208
 209         if (np->opt && np->opt->srcrt) {
 210                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 211                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 212         }
 213
 214         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
 215                           "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
 216                           __FUNCTION__, skb, skb->len,
 217                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
 218
 219         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 220
 221         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
 222 }
 223
 224 /* Returns the dst cache entry for the given source and destination ip
 225  * addresses.
 226  */
 227 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 228                                          union sctp_addr *daddr,
 229                                          union sctp_addr *saddr)
 230 {
 231         struct dst_entry *dst;
 232         struct flowi fl;
 233
 234         memset(&fl, 0, sizeof(fl));
 235         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 236         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 237                 fl.oif = daddr->v6.sin6_scope_id;
 238
 239
 240         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
 241                           __FUNCTION__, NIP6(fl.fl6_dst));
 242
 243         if (saddr) {
 244                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 245                 SCTP_DEBUG_PRINTK(
 246                         "SRC=" NIP6_FMT " - ",
 247                         NIP6(fl.fl6_src));
 248         }
 249
 250         dst = ip6_route_output(NULL, &fl);
 251         if (!dst->error) {
 252                 struct rt6_info *rt;
 253                 rt = (struct rt6_info *)dst;
 254                 SCTP_DEBUG_PRINTK(
 255                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
 256                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
 257                 return dst;
 258         }
 259         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 260         dst_release(dst);
 261         return NULL;
 262 }
 263
 264 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 265  * addresses.
 266  */
 267 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 268                                          union sctp_addr *s2)
 269 {
 270         struct in6_addr *a1 = &s1->v6.sin6_addr;
 271         struct in6_addr *a2 = &s2->v6.sin6_addr;
 272         int i, j;
 273
 274         for (i = 0; i < 4 ; i++) {
 275                 __be32 a1xora2;
 276
 277                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 278
 279                 if ((j = fls(ntohl(a1xora2))))
 280                         return (i * 32 + 32 - j);
 281         }
 282
 283         return (i*32);
 284 }
 285
 286 /* Fills in the source address(saddr) based on the destination address(daddr)
 287  * and asoc's bind address list.
 288  */
 289 static void sctp_v6_get_saddr(struct sctp_association *asoc,
 290                               struct dst_entry *dst,
 291                               union sctp_addr *daddr,
 292                               union sctp_addr *saddr)
 293 {
 294         struct sctp_bind_addr *bp;
 295         rwlock_t *addr_lock;
 296         struct sctp_sockaddr_entry *laddr;
 297         struct list_head *pos;
 298         sctp_scope_t scope;
 299         union sctp_addr *baddr = NULL;
 300         __u8 matchlen = 0;
 301         __u8 bmatchlen;
 302
 303         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
 304                           "daddr:" NIP6_FMT " ",
 305                           __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
 306
 307         if (!asoc) {
 308                 ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
 309                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
 310                                   NIP6(saddr->v6.sin6_addr));
 311                 return;
 312         }
 313
 314         scope = sctp_scope(daddr);
 315
 316         bp = &asoc->base.bind_addr;
 317         addr_lock = &asoc->base.addr_lock;
 318
 319         /* Go through the bind address list and find the best source address
 320          * that matches the scope of the destination address.
 321          */
 322         sctp_read_lock(addr_lock);
 323         list_for_each(pos, &bp->address_list) {
 324                 laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
 325                 if ((laddr->use_as_src) &&
 326                     (laddr->a.sa.sa_family == AF_INET6) &&
 327                     (scope <= sctp_scope(&laddr->a))) {
 328                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 329                         if (!baddr || (matchlen < bmatchlen)) {
 330                                 baddr = &laddr->a;
 331                                 matchlen = bmatchlen;
 332                         }
 333                 }
 334         }
 335
 336         if (baddr) {
 337                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 338                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
 339                                   NIP6(saddr->v6.sin6_addr));
 340         } else {
 341                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 342                        "address for the dest:" NIP6_FMT "\n",
 343                        __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
 344         }
 345
 346         sctp_read_unlock(addr_lock);
 347 }
 348
 349 /* Make a copy of all potential local addresses. */
 350 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 351                                   struct net_device *dev)
 352 {
 353         struct inet6_dev *in6_dev;
 354         struct inet6_ifaddr *ifp;
 355         struct sctp_sockaddr_entry *addr;
 356
 357         rcu_read_lock();
 358         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 359                 rcu_read_unlock();
 360                 return;
 361         }
 362
 363         read_lock(&in6_dev->lock);
 364         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 365                 /* Add the address to the local list.  */
 366                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 367                 if (addr) {
 368                         addr->a.v6.sin6_family = AF_INET6;
 369                         addr->a.v6.sin6_port = 0;
 370                         addr->a.v6.sin6_addr = ifp->addr;
 371                         addr->a.v6.sin6_scope_id = dev->ifindex;
 372                         INIT_LIST_HEAD(&addr->list);
 373                         list_add_tail(&addr->list, addrlist);
 374                 }
 375         }
 376
 377         read_unlock(&in6_dev->lock);
 378         rcu_read_unlock();
 379 }
 380
 381 /* Initialize a sockaddr_storage from in incoming skb. */
 382 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 383                              int is_saddr)
 384 {
 385         void *from;
 386         __be16 *port;
 387         struct sctphdr *sh;
 388
 389         port = &addr->v6.sin6_port;
 390         addr->v6.sin6_family = AF_INET6;
 391         addr->v6.sin6_flowinfo = 0; /* FIXME */
 392         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 393
 394         sh = (struct sctphdr *) skb->h.raw;
 395         if (is_saddr) {
 396                 *port  = sh->source;
 397                 from = &skb->nh.ipv6h->saddr;
 398         } else {
 399                 *port = sh->dest;
 400                 from = &skb->nh.ipv6h->daddr;
 401         }
 402         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 403 }
 404
 405 /* Initialize an sctp_addr from a socket. */
 406 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 407 {
 408         addr->v6.sin6_family = AF_INET6;
 409         addr->v6.sin6_port = 0;
 410         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 411 }
 412
 413 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 414 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 415 {
 416         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 417                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 418                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 419                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 420                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 421                         addr->v4.sin_addr.s_addr;
 422         } else {
 423                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 424         }
 425 }
 426
 427 /* Initialize sk->sk_daddr from sctp_addr. */
 428 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 429 {
 430         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 431                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 432                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 433                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 434                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 435         } else {
 436                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 437         }
 438 }
 439
 440 /* Initialize a sctp_addr from an address parameter. */
 441 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 442                                     union sctp_addr_param *param,
 443                                     __be16 port, int iif)
 444 {
 445         addr->v6.sin6_family = AF_INET6;
 446         addr->v6.sin6_port = port;
 447         addr->v6.sin6_flowinfo = 0; /* BUG */
 448         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 449         addr->v6.sin6_scope_id = iif;
 450 }
 451
 452 /* Initialize an address parameter from a sctp_addr and return the length
 453  * of the address parameter.
 454  */
 455 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 456                                  union sctp_addr_param *param)
 457 {
 458         int length = sizeof(sctp_ipv6addr_param_t);
 459
 460         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 461         param->v6.param_hdr.length = htons(length);
 462         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 463
 464         return length;
 465 }
 466
 467 /* Initialize a sctp_addr from a dst_entry. */
 468 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 469                               __be16 port)
 470 {
 471         struct rt6_info *rt = (struct rt6_info *)dst;
 472         addr->sa.sa_family = AF_INET6;
 473         addr->v6.sin6_port = port;
 474         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 475 }
 476
 477 /* Compare addresses exactly.
 478  * v4-mapped-v6 is also in consideration.
 479  */
 480 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 481                             const union sctp_addr *addr2)
 482 {
 483         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 484                 if (addr1->sa.sa_family == AF_INET &&
 485                     addr2->sa.sa_family == AF_INET6 &&
 486                     IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
 487                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 488                             addr2->v6.sin6_addr.s6_addr32[3] ==
 489                             addr1->v4.sin_addr.s_addr)
 490                                 return 1;
 491                 }
 492                 if (addr2->sa.sa_family == AF_INET &&
 493                     addr1->sa.sa_family == AF_INET6 &&
 494                     IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
 495                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 496                             addr1->v6.sin6_addr.s6_addr32[3] ==
 497                             addr2->v4.sin_addr.s_addr)
 498                                 return 1;
 499                 }
 500                 return 0;
 501         }
 502         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 503                 return 0;
 504         /* If this is a linklocal address, compare the scope_id. */
 505         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 506                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 507                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 508                         return 0;
 509                 }
 510         }
 511
 512         return 1;
 513 }
 514
 515 /* Initialize addr struct to INADDR_ANY. */
 516 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 517 {
 518         memset(addr, 0x00, sizeof(union sctp_addr));
 519         addr->v6.sin6_family = AF_INET6;
 520         addr->v6.sin6_port = port;
 521 }
 522
 523 /* Is this a wildcard address? */
 524 static int sctp_v6_is_any(const union sctp_addr *addr)
 525 {
 526         return ipv6_addr_any(&addr->v6.sin6_addr);
 527 }
 528
 529 /* Should this be available for binding?   */
 530 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 531 {
 532         int type;
 533         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 534
 535         type = ipv6_addr_type(in6);
 536         if (IPV6_ADDR_ANY == type)
 537                 return 1;
 538         if (type == IPV6_ADDR_MAPPED) {
 539                 if (sp && !sp->v4mapped)
 540                         return 0;
 541                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 542                         return 0;
 543                 sctp_v6_map_v4(addr);
 544                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 545         }
 546         if (!(type & IPV6_ADDR_UNICAST))
 547                 return 0;
 548
 549         return ipv6_chk_addr(in6, NULL, 0);
 550 }
 551
 552 /* This function checks if the address is a valid address to be used for
 553  * SCTP.
 554  *
 555  * Output:
 556  * Return 0 - If the address is a non-unicast or an illegal address.
 557  * Return 1 - If the address is a unicast.
 558  */
 559 static int sctp_v6_addr_valid(union sctp_addr *addr,
 560                               struct sctp_sock *sp,
 561                               const struct sk_buff *skb)
 562 {
 563         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 564
 565         /* Support v4-mapped-v6 address. */
 566         if (ret == IPV6_ADDR_MAPPED) {
 567                 /* Note: This routine is used in input, so v4-mapped-v6
 568                  * are disallowed here when there is no sctp_sock.
 569                  */
 570                 if (!sp || !sp->v4mapped)
 571                         return 0;
 572                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 573                         return 0;
 574                 sctp_v6_map_v4(addr);
 575                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 576         }
 577
 578         /* Is this a non-unicast address */
 579         if (!(ret & IPV6_ADDR_UNICAST))
 580                 return 0;
 581
 582         return 1;
 583 }
 584
 585 /* What is the scope of 'addr'?  */
 586 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 587 {
 588         int v6scope;
 589         sctp_scope_t retval;
 590
 591         /* The IPv6 scope is really a set of bit fields.
 592          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 593          */
 594
 595         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 596         switch (v6scope) {
 597         case IFA_HOST:
 598                 retval = SCTP_SCOPE_LOOPBACK;
 599                 break;
 600         case IFA_LINK:
 601                 retval = SCTP_SCOPE_LINK;
 602                 break;
 603         case IFA_SITE:
 604                 retval = SCTP_SCOPE_PRIVATE;
 605                 break;
 606         default:
 607                 retval = SCTP_SCOPE_GLOBAL;
 608                 break;
 609         };
 610
 611         return retval;
 612 }
 613
 614 /* Create and initialize a new sk for the socket to be returned by accept(). */
 615 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 616                                              struct sctp_association *asoc)
 617 {
 618         struct inet_sock *inet = inet_sk(sk);
 619         struct sock *newsk;
 620         struct inet_sock *newinet;
 621         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 622         struct sctp6_sock *newsctp6sk;
 623
 624         newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot, 1);
 625         if (!newsk)
 626                 goto out;
 627
 628         sock_init_data(NULL, newsk);
 629
 630         newsk->sk_type = SOCK_STREAM;
 631
 632         newsk->sk_prot = sk->sk_prot;
 633         newsk->sk_no_check = sk->sk_no_check;
 634         newsk->sk_reuse = sk->sk_reuse;
 635
 636         newsk->sk_destruct = inet_sock_destruct;
 637         newsk->sk_family = PF_INET6;
 638         newsk->sk_protocol = IPPROTO_SCTP;
 639         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 640         newsk->sk_shutdown = sk->sk_shutdown;
 641         sock_reset_flag(sk, SOCK_ZAPPED);
 642
 643         newsctp6sk = (struct sctp6_sock *)newsk;
 644         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 645
 646         newinet = inet_sk(newsk);
 647         newnp = inet6_sk(newsk);
 648
 649         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 650
 651         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 652          * and getpeername().
 653          */
 654         newinet->sport = inet->sport;
 655         newnp->saddr = np->saddr;
 656         newnp->rcv_saddr = np->rcv_saddr;
 657         newinet->dport = htons(asoc->peer.port);
 658         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 659
 660         /* Init the ipv4 part of the socket since we can have sockets
 661          * using v6 API for ipv4.
 662          */
 663         newinet->uc_ttl = -1;
 664         newinet->mc_loop = 1;
 665         newinet->mc_ttl = 1;
 666         newinet->mc_index = 0;
 667         newinet->mc_list = NULL;
 668
 669         if (ipv4_config.no_pmtu_disc)
 670                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 671         else
 672                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 673
 674         sk_refcnt_debug_inc(newsk);
 675
 676         if (newsk->sk_prot->init(newsk)) {
 677                 sk_common_release(newsk);
 678                 newsk = NULL;
 679         }
 680
 681 out:
 682         return newsk;
 683 }
 684
 685 /* Map v4 address to mapped v6 address */
 686 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 687 {
 688         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 689                 sctp_v4_map_v6(addr);
 690 }
 691
 692 /* Where did this skb come from?  */
 693 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 694 {
 695         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 696         return opt->iif;
 697 }
 698
 699 /* Was this packet marked by Explicit Congestion Notification? */
 700 static int sctp_v6_is_ce(const struct sk_buff *skb)
 701 {
 702         return *((__u32 *)(skb->nh.ipv6h)) & htonl(1<<20);
 703 }
 704
 705 /* Dump the v6 addr to the seq file. */
 706 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 707 {
 708         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
 709 }
 710
 711 /* Initialize a PF_INET6 socket msg_name. */
 712 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 713 {
 714         struct sockaddr_in6 *sin6;
 715
 716         sin6 = (struct sockaddr_in6 *)msgname;
 717         sin6->sin6_family = AF_INET6;
 718         sin6->sin6_flowinfo = 0;
 719         sin6->sin6_scope_id = 0; /*FIXME */
 720         *addr_len = sizeof(struct sockaddr_in6);
 721 }
 722
 723 /* Initialize a PF_INET msgname from a ulpevent. */
 724 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 725                                      char *msgname, int *addrlen)
 726 {
 727         struct sockaddr_in6 *sin6, *sin6from;
 728
 729         if (msgname) {
 730                 union sctp_addr *addr;
 731                 struct sctp_association *asoc;
 732
 733                 asoc = event->asoc;
 734                 sctp_inet6_msgname(msgname, addrlen);
 735                 sin6 = (struct sockaddr_in6 *)msgname;
 736                 sin6->sin6_port = htons(asoc->peer.port);
 737                 addr = &asoc->peer.primary_addr;
 738
 739                 /* Note: If we go to a common v6 format, this code
 740                  * will change.
 741                  */
 742
 743                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 744                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 745                     AF_INET == addr->sa.sa_family) {
 746                         sctp_v4_map_v6((union sctp_addr *)sin6);
 747                         sin6->sin6_addr.s6_addr32[3] =
 748                                 addr->v4.sin_addr.s_addr;
 749                         return;
 750                 }
 751
 752                 sin6from = &asoc->peer.primary_addr.v6;
 753                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 754                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 755                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 756         }
 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         struct sctphdr *sh;
 764         struct sockaddr_in6 *sin6;
 765
 766         if (msgname) {
 767                 sctp_inet6_msgname(msgname, addr_len);
 768                 sin6 = (struct sockaddr_in6 *)msgname;
 769                 sh = (struct sctphdr *)skb->h.raw;
 770                 sin6->sin6_port = sh->source;
 771
 772                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 773                 if (sctp_sk(skb->sk)->v4mapped &&
 774                     skb->nh.iph->version == 4) {
 775                         sctp_v4_map_v6((union sctp_addr *)sin6);
 776                         sin6->sin6_addr.s6_addr32[3] = skb->nh.iph->saddr;
 777                         return;
 778                 }
 779
 780                 /* Otherwise, just copy the v6 address. */
 781                 ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
 782                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 783                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 784                         sin6->sin6_scope_id = ev->iif;
 785                 }
 786         }
 787 }
 788
 789 /* Do we support this AF? */
 790 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 791 {
 792         switch (family) {
 793         case AF_INET6:
 794                 return 1;
 795         /* v4-mapped-v6 addresses */
 796         case AF_INET:
 797                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
 798                         return 1;
 799         default:
 800                 return 0;
 801         }
 802 }
 803
 804 /* Address matching with wildcards allowed.  This extra level
 805  * of indirection lets us choose whether a PF_INET6 should
 806  * disallow any v4 addresses if we so choose.
 807  */
 808 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 809                                const union sctp_addr *addr2,
 810                                struct sctp_sock *opt)
 811 {
 812         struct sctp_af *af1, *af2;
 813
 814         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 815         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 816
 817         if (!af1 || !af2)
 818                 return 0;
 819         /* Today, wildcard AF_INET/AF_INET6. */
 820         if (sctp_is_any(addr1) || sctp_is_any(addr2))
 821                 return 1;
 822
 823         if (addr1->sa.sa_family != addr2->sa.sa_family)
 824                 return 0;
 825
 826         return af1->cmp_addr(addr1, addr2);
 827 }
 828
 829 /* Verify that the provided sockaddr looks bindable.   Common verification,
 830  * has already been taken care of.
 831  */
 832 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 833 {
 834         struct sctp_af *af;
 835
 836         /* ASSERT: address family has already been verified. */
 837         if (addr->sa.sa_family != AF_INET6)
 838                 af = sctp_get_af_specific(addr->sa.sa_family);
 839         else {
 840                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 841                 struct net_device *dev;
 842
 843                 if (type & IPV6_ADDR_LINKLOCAL) {
 844                         if (!addr->v6.sin6_scope_id)
 845                                 return 0;
 846                         dev = dev_get_by_index(addr->v6.sin6_scope_id);
 847                         if (!dev)
 848                                 return 0;
 849                         dev_put(dev);
 850                 }
 851                 af = opt->pf->af;
 852         }
 853         return af->available(addr, opt);
 854 }
 855
 856 /* Verify that the provided sockaddr looks sendable.   Common verification,
 857  * has already been taken care of.
 858  */
 859 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 860 {
 861         struct sctp_af *af = NULL;
 862
 863         /* ASSERT: address family has already been verified. */
 864         if (addr->sa.sa_family != AF_INET6)
 865                 af = sctp_get_af_specific(addr->sa.sa_family);
 866         else {
 867                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 868                 struct net_device *dev;
 869
 870                 if (type & IPV6_ADDR_LINKLOCAL) {
 871                         if (!addr->v6.sin6_scope_id)
 872                                 return 0;
 873                         dev = dev_get_by_index(addr->v6.sin6_scope_id);
 874                         if (!dev)
 875                                 return 0;
 876                         dev_put(dev);
 877                 }
 878                 af = opt->pf->af;
 879         }
 880
 881         return af != NULL;
 882 }
 883
 884 /* Fill in Supported Address Type information for INIT and INIT-ACK
 885  * chunks.   Note: In the future, we may want to look at sock options
 886  * to determine whether a PF_INET6 socket really wants to have IPV4
 887  * addresses.
 888  * Returns number of addresses supported.
 889  */
 890 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 891                                       __be16 *types)
 892 {
 893         types[0] = SCTP_PARAM_IPV4_ADDRESS;
 894         types[1] = SCTP_PARAM_IPV6_ADDRESS;
 895         return 2;
 896 }
 897
 898 static const struct proto_ops inet6_seqpacket_ops = {
 899         .family            = PF_INET6,
 900         .owner             = THIS_MODULE,
 901         .release           = inet6_release,
 902         .bind              = inet6_bind,
 903         .connect           = inet_dgram_connect,
 904         .socketpair        = sock_no_socketpair,
 905         .accept            = inet_accept,
 906         .getname           = inet6_getname,
 907         .poll              = sctp_poll,
 908         .ioctl             = inet6_ioctl,
 909         .listen            = sctp_inet_listen,
 910         .shutdown          = inet_shutdown,
 911         .setsockopt        = sock_common_setsockopt,
 912         .getsockopt        = sock_common_getsockopt,
 913         .sendmsg           = inet_sendmsg,
 914         .recvmsg           = sock_common_recvmsg,
 915         .mmap              = sock_no_mmap,
 916 #ifdef CONFIG_COMPAT
 917         .compat_setsockopt = compat_sock_common_setsockopt,
 918         .compat_getsockopt = compat_sock_common_getsockopt,
 919 #endif
 920 };
 921
 922 static struct inet_protosw sctpv6_seqpacket_protosw = {
 923         .type          = SOCK_SEQPACKET,
 924         .protocol      = IPPROTO_SCTP,
 925         .prot          = &sctpv6_prot,
 926         .ops           = &inet6_seqpacket_ops,
 927         .capability    = -1,
 928         .no_check      = 0,
 929         .flags         = SCTP_PROTOSW_FLAG
 930 };
 931 static struct inet_protosw sctpv6_stream_protosw = {
 932         .type          = SOCK_STREAM,
 933         .protocol      = IPPROTO_SCTP,
 934         .prot          = &sctpv6_prot,
 935         .ops           = &inet6_seqpacket_ops,
 936         .capability    = -1,
 937         .no_check      = 0,
 938         .flags         = SCTP_PROTOSW_FLAG,
 939 };
 940
 941 static int sctp6_rcv(struct sk_buff **pskb)
 942 {
 943         return sctp_rcv(*pskb) ? -1 : 0;
 944 }
 945
 946 static struct inet6_protocol sctpv6_protocol = {
 947         .handler      = sctp6_rcv,
 948         .err_handler  = sctp_v6_err,
 949         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 950 };
 951
 952 static struct sctp_af sctp_ipv6_specific = {
 953         .sa_family         = AF_INET6,
 954         .sctp_xmit         = sctp_v6_xmit,
 955         .setsockopt        = ipv6_setsockopt,
 956         .getsockopt        = ipv6_getsockopt,
 957         .get_dst           = sctp_v6_get_dst,
 958         .get_saddr         = sctp_v6_get_saddr,
 959         .copy_addrlist     = sctp_v6_copy_addrlist,
 960         .from_skb          = sctp_v6_from_skb,
 961         .from_sk           = sctp_v6_from_sk,
 962         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 963         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 964         .from_addr_param   = sctp_v6_from_addr_param,
 965         .to_addr_param     = sctp_v6_to_addr_param,
 966         .dst_saddr         = sctp_v6_dst_saddr,
 967         .cmp_addr          = sctp_v6_cmp_addr,
 968         .scope             = sctp_v6_scope,
 969         .addr_valid        = sctp_v6_addr_valid,
 970         .inaddr_any        = sctp_v6_inaddr_any,
 971         .is_any            = sctp_v6_is_any,
 972         .available         = sctp_v6_available,
 973         .skb_iif           = sctp_v6_skb_iif,
 974         .is_ce             = sctp_v6_is_ce,
 975         .seq_dump_addr     = sctp_v6_seq_dump_addr,
 976         .net_header_len    = sizeof(struct ipv6hdr),
 977         .sockaddr_len      = sizeof(struct sockaddr_in6),
 978 #ifdef CONFIG_COMPAT
 979         .compat_setsockopt = compat_ipv6_setsockopt,
 980         .compat_getsockopt = compat_ipv6_getsockopt,
 981 #endif
 982 };
 983
 984 static struct sctp_pf sctp_pf_inet6_specific = {
 985         .event_msgname = sctp_inet6_event_msgname,
 986         .skb_msgname   = sctp_inet6_skb_msgname,
 987         .af_supported  = sctp_inet6_af_supported,
 988         .cmp_addr      = sctp_inet6_cmp_addr,
 989         .bind_verify   = sctp_inet6_bind_verify,
 990         .send_verify   = sctp_inet6_send_verify,
 991         .supported_addrs = sctp_inet6_supported_addrs,
 992         .create_accept_sk = sctp_v6_create_accept_sk,
 993         .addr_v4map    = sctp_v6_addr_v4map,
 994         .af            = &sctp_ipv6_specific,
 995 };
 996
 997 /* Initialize IPv6 support and register with inet6 stack.  */
 998 int sctp_v6_init(void)
 999 {
1000         int rc = proto_register(&sctpv6_prot, 1);
1001
1002         if (rc)
1003                 goto out;
1004         /* Register inet6 protocol. */
1005         rc = -EAGAIN;
1006         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1007                 goto out_unregister_sctp_proto;
1008
1009         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1010         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1011         inet6_register_protosw(&sctpv6_stream_protosw);
1012
1013         /* Register the SCTP specific PF_INET6 functions. */
1014         sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
1015
1016         /* Register the SCTP specific AF_INET6 functions. */
1017         sctp_register_af(&sctp_ipv6_specific);
1018
1019         /* Register notifier for inet6 address additions/deletions. */
1020         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1021         rc = 0;
1022 out:
1023         return rc;
1024 out_unregister_sctp_proto:
1025         proto_unregister(&sctpv6_prot);
1026         goto out;
1027 }
1028
1029 /* IPv6 specific exit support. */
1030 void sctp_v6_exit(void)
1031 {
1032         list_del(&sctp_ipv6_specific.list);
1033         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1034         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1035         inet6_unregister_protosw(&sctpv6_stream_protosw);
1036         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1037         proto_unregister(&sctpv6_prot);
1038 }