net/sctp/ipv6.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2002, 2004
   3  * Copyright (c) 2001 Nokia, Inc.
   4  * Copyright (c) 2001 La Monte H.P. Yarroll
   5  * Copyright (c) 2002-2003 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * This SCTP implementation is free software;
  12  * you can redistribute it and/or modify it under the terms of
  13  * the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This SCTP implementation is distributed in the hope that it
  18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19  *                 ************************
  20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21  * See the GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with GNU CC; see the file COPYING.  If not, see
  25  * <http://www.gnu.org/licenses/>.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    Le Yanqun             <yanqun.le@nokia.com>
  33  *    Hui Huang             <hui.huang@nokia.com>
  34  *    La Monte H.P. Yarroll <piggy@acm.org>
  35  *    Sridhar Samudrala     <sri@us.ibm.com>
  36  *    Jon Grimm             <jgrimm@us.ibm.com>
  37  *    Ardelle Fan           <ardelle.fan@intel.com>
  38  *
  39  * Based on:
  40  *      linux/net/ipv6/tcp_ipv6.c
  41  */
  42
  43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  44
  45 #include <linux/module.h>
  46 #include <linux/errno.h>
  47 #include <linux/types.h>
  48 #include <linux/socket.h>
  49 #include <linux/sockios.h>
  50 #include <linux/net.h>
  51 #include <linux/in.h>
  52 #include <linux/in6.h>
  53 #include <linux/netdevice.h>
  54 #include <linux/init.h>
  55 #include <linux/ipsec.h>
  56 #include <linux/slab.h>
  57
  58 #include <linux/ipv6.h>
  59 #include <linux/icmpv6.h>
  60 #include <linux/random.h>
  61 #include <linux/seq_file.h>
  62
  63 #include <net/protocol.h>
  64 #include <net/ndisc.h>
  65 #include <net/ip.h>
  66 #include <net/ipv6.h>
  67 #include <net/transp_v6.h>
  68 #include <net/addrconf.h>
  69 #include <net/ip6_route.h>
  70 #include <net/inet_common.h>
  71 #include <net/inet_ecn.h>
  72 #include <net/sctp/sctp.h>
  73
  74 #include <asm/uaccess.h>
  75
  76 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  77                                          union sctp_addr *s2);
  78 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  79                               __be16 port);
  80 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  81                             const union sctp_addr *addr2);
  82
  83 /* Event handler for inet6 address addition/deletion events.
  84  * The sctp_local_addr_list needs to be protocted by a spin lock since
  85  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  86  * time and thus corrupt the list.
  87  * The reader side is protected with RCU.
  88  */
  89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  90                                 void *ptr)
  91 {
  92         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  93         struct sctp_sockaddr_entry *addr = NULL;
  94         struct sctp_sockaddr_entry *temp;
  95         struct net *net = dev_net(ifa->idev->dev);
  96         int found = 0;
  97
  98         switch (ev) {
  99         case NETDEV_UP:
 100                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 101                 if (addr) {
 102                         addr->a.v6.sin6_family = AF_INET6;
 103                         addr->a.v6.sin6_addr = ifa->addr;
 104                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 105                         addr->valid = 1;
 106                         spin_lock_bh(&net->sctp.local_addr_lock);
 107                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 108                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 109                         spin_unlock_bh(&net->sctp.local_addr_lock);
 110                 }
 111                 break;
 112         case NETDEV_DOWN:
 113                 spin_lock_bh(&net->sctp.local_addr_lock);
 114                 list_for_each_entry_safe(addr, temp,
 115                                         &net->sctp.local_addr_list, list) {
 116                         if (addr->a.sa.sa_family == AF_INET6 &&
 117                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 118                                                 &ifa->addr)) {
 119                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 120                                 found = 1;
 121                                 addr->valid = 0;
 122                                 list_del_rcu(&addr->list);
 123                                 break;
 124                         }
 125                 }
 126                 spin_unlock_bh(&net->sctp.local_addr_lock);
 127                 if (found)
 128                         kfree_rcu(addr, rcu);
 129                 break;
 130         }
 131
 132         return NOTIFY_DONE;
 133 }
 134
 135 static struct notifier_block sctp_inet6addr_notifier = {
 136         .notifier_call = sctp_inet6addr_event,
 137 };
 138
 139 /* ICMP error handler. */
 140 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 141                         u8 type, u8 code, int offset, __be32 info)
 142 {
 143         struct inet6_dev *idev;
 144         struct sock *sk;
 145         struct sctp_association *asoc;
 146         struct sctp_transport *transport;
 147         struct ipv6_pinfo *np;
 148         __u16 saveip, savesctp;
 149         int err;
 150         struct net *net = dev_net(skb->dev);
 151
 152         idev = in6_dev_get(skb->dev);
 153
 154         /* Fix up skb to look at the embedded net header. */
 155         saveip   = skb->network_header;
 156         savesctp = skb->transport_header;
 157         skb_reset_network_header(skb);
 158         skb_set_transport_header(skb, offset);
 159         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 160         /* Put back, the original pointers. */
 161         skb->network_header   = saveip;
 162         skb->transport_header = savesctp;
 163         if (!sk) {
 164                 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_INERRORS);
 165                 goto out;
 166         }
 167
 168         /* Warning:  The sock lock is held.  Remember to call
 169          * sctp_err_finish!
 170          */
 171
 172         switch (type) {
 173         case ICMPV6_PKT_TOOBIG:
 174                 if (ip6_sk_accept_pmtu(sk))
 175                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 176                 goto out_unlock;
 177         case ICMPV6_PARAMPROB:
 178                 if (ICMPV6_UNK_NEXTHDR == code) {
 179                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 180                         goto out_unlock;
 181                 }
 182                 break;
 183         case NDISC_REDIRECT:
 184                 sctp_icmp_redirect(sk, transport, skb);
 185                 goto out_unlock;
 186         default:
 187                 break;
 188         }
 189
 190         np = inet6_sk(sk);
 191         icmpv6_err_convert(type, code, &err);
 192         if (!sock_owned_by_user(sk) && np->recverr) {
 193                 sk->sk_err = err;
 194                 sk->sk_error_report(sk);
 195         } else {  /* Only an error on timeout */
 196                 sk->sk_err_soft = err;
 197         }
 198
 199 out_unlock:
 200         sctp_err_finish(sk, asoc);
 201 out:
 202         if (likely(idev != NULL))
 203                 in6_dev_put(idev);
 204 }
 205
 206 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 207 {
 208         struct sock *sk = skb->sk;
 209         struct ipv6_pinfo *np = inet6_sk(sk);
 210         struct flowi6 *fl6 = &transport->fl.u.ip6;
 211         int res;
 212
 213         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 214                  skb->len, &fl6->saddr, &fl6->daddr);
 215
 216         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 217
 218         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 219                 skb->ignore_df = 1;
 220
 221         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 222
 223         rcu_read_lock();
 224         res = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt), np->tclass);
 225         rcu_read_unlock();
 226         return res;
 227 }
 228
 229 /* Returns the dst cache entry for the given source and destination ip
 230  * addresses.
 231  */
 232 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 233                             struct flowi *fl, struct sock *sk)
 234 {
 235         struct sctp_association *asoc = t->asoc;
 236         struct dst_entry *dst = NULL;
 237         struct flowi6 *fl6 = &fl->u.ip6;
 238         struct sctp_bind_addr *bp;
 239         struct ipv6_pinfo *np = inet6_sk(sk);
 240         struct sctp_sockaddr_entry *laddr;
 241         union sctp_addr *daddr = &t->ipaddr;
 242         union sctp_addr dst_saddr;
 243         struct in6_addr *final_p, final;
 244         __u8 matchlen = 0;
 245         sctp_scope_t scope;
 246
 247         memset(fl6, 0, sizeof(struct flowi6));
 248         fl6->daddr = daddr->v6.sin6_addr;
 249         fl6->fl6_dport = daddr->v6.sin6_port;
 250         fl6->flowi6_proto = IPPROTO_SCTP;
 251         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 252                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 253
 254         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 255
 256         if (asoc)
 257                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 258
 259         if (saddr) {
 260                 fl6->saddr = saddr->v6.sin6_addr;
 261                 fl6->fl6_sport = saddr->v6.sin6_port;
 262
 263                 pr_debug("src=%pI6 - ", &fl6->saddr);
 264         }
 265
 266         rcu_read_lock();
 267         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 268         rcu_read_unlock();
 269
 270         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 271         if (!asoc || saddr)
 272                 goto out;
 273
 274         bp = &asoc->base.bind_addr;
 275         scope = sctp_scope(daddr);
 276         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 277          * to see if we can use it.
 278          */
 279         if (!IS_ERR(dst)) {
 280                 /* Walk through the bind address list and look for a bind
 281                  * address that matches the source address of the returned dst.
 282                  */
 283                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 284                 rcu_read_lock();
 285                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 286                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 287                             (laddr->state != SCTP_ADDR_SRC &&
 288                              !asoc->src_out_of_asoc_ok))
 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                 struct dst_entry *bdst;
 312                 __u8 bmatchlen;
 313
 314                 if (!laddr->valid ||
 315                     laddr->state != SCTP_ADDR_SRC ||
 316                     laddr->a.sa.sa_family != AF_INET6 ||
 317                     scope > sctp_scope(&laddr->a))
 318                         continue;
 319
 320                 fl6->saddr = laddr->a.v6.sin6_addr;
 321                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 322                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 323                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 324
 325                 if (IS_ERR(bdst))
 326                         continue;
 327
 328                 if (ipv6_chk_addr(dev_net(bdst->dev),
 329                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 330                         if (!IS_ERR_OR_NULL(dst))
 331                                 dst_release(dst);
 332                         dst = bdst;
 333                         break;
 334                 }
 335
 336                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 337                 if (matchlen > bmatchlen) {
 338                         dst_release(bdst);
 339                         continue;
 340                 }
 341
 342                 if (!IS_ERR_OR_NULL(dst))
 343                         dst_release(dst);
 344                 dst = bdst;
 345                 matchlen = bmatchlen;
 346         }
 347         rcu_read_unlock();
 348
 349 out:
 350         if (!IS_ERR_OR_NULL(dst)) {
 351                 struct rt6_info *rt;
 352
 353                 rt = (struct rt6_info *)dst;
 354                 t->dst = dst;
 355                 t->dst_cookie = rt6_get_cookie(rt);
 356                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 357                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 358                          &fl6->saddr);
 359         } else {
 360                 t->dst = NULL;
 361
 362                 pr_debug("no route\n");
 363         }
 364 }
 365
 366 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 367  * addresses.
 368  */
 369 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 370                                          union sctp_addr *s2)
 371 {
 372         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 373 }
 374
 375 /* Fills in the source address(saddr) based on the destination address(daddr)
 376  * and asoc's bind address list.
 377  */
 378 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 379                               struct sctp_transport *t,
 380                               struct flowi *fl)
 381 {
 382         struct flowi6 *fl6 = &fl->u.ip6;
 383         union sctp_addr *saddr = &t->saddr;
 384
 385         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 386
 387         if (t->dst) {
 388                 saddr->v6.sin6_family = AF_INET6;
 389                 saddr->v6.sin6_addr = fl6->saddr;
 390         }
 391 }
 392
 393 /* Make a copy of all potential local addresses. */
 394 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 395                                   struct net_device *dev)
 396 {
 397         struct inet6_dev *in6_dev;
 398         struct inet6_ifaddr *ifp;
 399         struct sctp_sockaddr_entry *addr;
 400
 401         rcu_read_lock();
 402         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 403                 rcu_read_unlock();
 404                 return;
 405         }
 406
 407         read_lock_bh(&in6_dev->lock);
 408         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 409                 /* Add the address to the local list.  */
 410                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 411                 if (addr) {
 412                         addr->a.v6.sin6_family = AF_INET6;
 413                         addr->a.v6.sin6_addr = ifp->addr;
 414                         addr->a.v6.sin6_scope_id = dev->ifindex;
 415                         addr->valid = 1;
 416                         INIT_LIST_HEAD(&addr->list);
 417                         list_add_tail(&addr->list, addrlist);
 418                 }
 419         }
 420
 421         read_unlock_bh(&in6_dev->lock);
 422         rcu_read_unlock();
 423 }
 424
 425 /* Initialize a sockaddr_storage from in incoming skb. */
 426 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 427                              int is_saddr)
 428 {
 429         __be16 *port;
 430         struct sctphdr *sh;
 431
 432         port = &addr->v6.sin6_port;
 433         addr->v6.sin6_family = AF_INET6;
 434         addr->v6.sin6_flowinfo = 0; /* FIXME */
 435         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 436
 437         sh = sctp_hdr(skb);
 438         if (is_saddr) {
 439                 *port  = sh->source;
 440                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 441         } else {
 442                 *port = sh->dest;
 443                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 444         }
 445 }
 446
 447 /* Initialize an sctp_addr from a socket. */
 448 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 449 {
 450         addr->v6.sin6_family = AF_INET6;
 451         addr->v6.sin6_port = 0;
 452         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 453 }
 454
 455 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 456 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 457 {
 458         if (addr->sa.sa_family == AF_INET) {
 459                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 460                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 461                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 462                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 463                         addr->v4.sin_addr.s_addr;
 464         } else {
 465                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 466         }
 467 }
 468
 469 /* Initialize sk->sk_daddr from sctp_addr. */
 470 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 471 {
 472         if (addr->sa.sa_family == AF_INET) {
 473                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 474                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 475                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 476                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 477         } else {
 478                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 479         }
 480 }
 481
 482 /* Initialize a sctp_addr from an address parameter. */
 483 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 484                                     union sctp_addr_param *param,
 485                                     __be16 port, int iif)
 486 {
 487         addr->v6.sin6_family = AF_INET6;
 488         addr->v6.sin6_port = port;
 489         addr->v6.sin6_flowinfo = 0; /* BUG */
 490         addr->v6.sin6_addr = param->v6.addr;
 491         addr->v6.sin6_scope_id = iif;
 492 }
 493
 494 /* Initialize an address parameter from a sctp_addr and return the length
 495  * of the address parameter.
 496  */
 497 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 498                                  union sctp_addr_param *param)
 499 {
 500         int length = sizeof(sctp_ipv6addr_param_t);
 501
 502         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 503         param->v6.param_hdr.length = htons(length);
 504         param->v6.addr = addr->v6.sin6_addr;
 505
 506         return length;
 507 }
 508
 509 /* Initialize a sctp_addr from struct in6_addr. */
 510 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 511                               __be16 port)
 512 {
 513         addr->sa.sa_family = AF_INET6;
 514         addr->v6.sin6_port = port;
 515         addr->v6.sin6_flowinfo = 0;
 516         addr->v6.sin6_addr = *saddr;
 517         addr->v6.sin6_scope_id = 0;
 518 }
 519
 520 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 521                               const union sctp_addr *addr2)
 522 {
 523         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 524                 if (addr1->sa.sa_family == AF_INET &&
 525                     addr2->sa.sa_family == AF_INET6 &&
 526                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 527                     addr2->v6.sin6_addr.s6_addr32[3] ==
 528                     addr1->v4.sin_addr.s_addr)
 529                         return 1;
 530
 531                 if (addr2->sa.sa_family == AF_INET &&
 532                     addr1->sa.sa_family == AF_INET6 &&
 533                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 534                     addr1->v6.sin6_addr.s6_addr32[3] ==
 535                     addr2->v4.sin_addr.s_addr)
 536                         return 1;
 537
 538                 return 0;
 539         }
 540
 541         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 542                 return 0;
 543
 544         /* If this is a linklocal address, compare the scope_id. */
 545         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 546             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 547             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 548                 return 0;
 549
 550         return 1;
 551 }
 552
 553 /* Compare addresses exactly.
 554  * v4-mapped-v6 is also in consideration.
 555  */
 556 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 557                             const union sctp_addr *addr2)
 558 {
 559         return __sctp_v6_cmp_addr(addr1, addr2) &&
 560                addr1->v6.sin6_port == addr2->v6.sin6_port;
 561 }
 562
 563 /* Initialize addr struct to INADDR_ANY. */
 564 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 565 {
 566         memset(addr, 0x00, sizeof(union sctp_addr));
 567         addr->v6.sin6_family = AF_INET6;
 568         addr->v6.sin6_port = port;
 569 }
 570
 571 /* Is this a wildcard address? */
 572 static int sctp_v6_is_any(const union sctp_addr *addr)
 573 {
 574         return ipv6_addr_any(&addr->v6.sin6_addr);
 575 }
 576
 577 /* Should this be available for binding?   */
 578 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 579 {
 580         int type;
 581         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 582
 583         type = ipv6_addr_type(in6);
 584         if (IPV6_ADDR_ANY == type)
 585                 return 1;
 586         if (type == IPV6_ADDR_MAPPED) {
 587                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 588                         return 0;
 589                 sctp_v6_map_v4(addr);
 590                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 591         }
 592         if (!(type & IPV6_ADDR_UNICAST))
 593                 return 0;
 594
 595         return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
 596 }
 597
 598 /* This function checks if the address is a valid address to be used for
 599  * SCTP.
 600  *
 601  * Output:
 602  * Return 0 - If the address is a non-unicast or an illegal address.
 603  * Return 1 - If the address is a unicast.
 604  */
 605 static int sctp_v6_addr_valid(union sctp_addr *addr,
 606                               struct sctp_sock *sp,
 607                               const struct sk_buff *skb)
 608 {
 609         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 610
 611         /* Support v4-mapped-v6 address. */
 612         if (ret == IPV6_ADDR_MAPPED) {
 613                 /* Note: This routine is used in input, so v4-mapped-v6
 614                  * are disallowed here when there is no sctp_sock.
 615                  */
 616                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 617                         return 0;
 618                 sctp_v6_map_v4(addr);
 619                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 620         }
 621
 622         /* Is this a non-unicast address */
 623         if (!(ret & IPV6_ADDR_UNICAST))
 624                 return 0;
 625
 626         return 1;
 627 }
 628
 629 /* What is the scope of 'addr'?  */
 630 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 631 {
 632         int v6scope;
 633         sctp_scope_t retval;
 634
 635         /* The IPv6 scope is really a set of bit fields.
 636          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 637          */
 638
 639         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 640         switch (v6scope) {
 641         case IFA_HOST:
 642                 retval = SCTP_SCOPE_LOOPBACK;
 643                 break;
 644         case IFA_LINK:
 645                 retval = SCTP_SCOPE_LINK;
 646                 break;
 647         case IFA_SITE:
 648                 retval = SCTP_SCOPE_PRIVATE;
 649                 break;
 650         default:
 651                 retval = SCTP_SCOPE_GLOBAL;
 652                 break;
 653         }
 654
 655         return retval;
 656 }
 657
 658 /* Create and initialize a new sk for the socket to be returned by accept(). */
 659 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 660                                              struct sctp_association *asoc)
 661 {
 662         struct sock *newsk;
 663         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 664         struct sctp6_sock *newsctp6sk;
 665         struct ipv6_txoptions *opt;
 666
 667         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0);
 668         if (!newsk)
 669                 goto out;
 670
 671         sock_init_data(NULL, newsk);
 672
 673         sctp_copy_sock(newsk, sk, asoc);
 674         sock_reset_flag(sk, SOCK_ZAPPED);
 675
 676         newsctp6sk = (struct sctp6_sock *)newsk;
 677         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 678
 679         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 680
 681         newnp = inet6_sk(newsk);
 682
 683         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 684         newnp->ipv6_mc_list = NULL;
 685         newnp->ipv6_ac_list = NULL;
 686         newnp->ipv6_fl_list = NULL;
 687
 688         rcu_read_lock();
 689         opt = rcu_dereference(np->opt);
 690         if (opt)
 691                 opt = ipv6_dup_options(newsk, opt);
 692         RCU_INIT_POINTER(newnp->opt, opt);
 693         rcu_read_unlock();
 694
 695         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 696          * and getpeername().
 697          */
 698         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 699
 700         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 701
 702         sk_refcnt_debug_inc(newsk);
 703
 704         if (newsk->sk_prot->init(newsk)) {
 705                 sk_common_release(newsk);
 706                 newsk = NULL;
 707         }
 708
 709 out:
 710         return newsk;
 711 }
 712
 713 /* Format a sockaddr for return to user space. This makes sure the return is
 714  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 715  */
 716 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 717 {
 718         if (sp->v4mapped) {
 719                 if (addr->sa.sa_family == AF_INET)
 720                         sctp_v4_map_v6(addr);
 721         } else {
 722                 if (addr->sa.sa_family == AF_INET6 &&
 723                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 724                         sctp_v6_map_v4(addr);
 725         }
 726
 727         if (addr->sa.sa_family == AF_INET) {
 728                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 729                 return sizeof(struct sockaddr_in);
 730         }
 731         return sizeof(struct sockaddr_in6);
 732 }
 733
 734 /* Where did this skb come from?  */
 735 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 736 {
 737         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 738         return opt->iif;
 739 }
 740
 741 /* Was this packet marked by Explicit Congestion Notification? */
 742 static int sctp_v6_is_ce(const struct sk_buff *skb)
 743 {
 744         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 745 }
 746
 747 /* Dump the v6 addr to the seq file. */
 748 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 749 {
 750         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 751 }
 752
 753 static void sctp_v6_ecn_capable(struct sock *sk)
 754 {
 755         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 756 }
 757
 758 /* Initialize a PF_INET msgname from a ulpevent. */
 759 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 760                                      char *msgname, int *addrlen)
 761 {
 762         union sctp_addr *addr;
 763         struct sctp_association *asoc;
 764         union sctp_addr *paddr;
 765
 766         if (!msgname)
 767                 return;
 768
 769         addr = (union sctp_addr *)msgname;
 770         asoc = event->asoc;
 771         paddr = &asoc->peer.primary_addr;
 772
 773         if (paddr->sa.sa_family == AF_INET) {
 774                 addr->v4.sin_family = AF_INET;
 775                 addr->v4.sin_port = htons(asoc->peer.port);
 776                 addr->v4.sin_addr = paddr->v4.sin_addr;
 777         } else {
 778                 addr->v6.sin6_family = AF_INET6;
 779                 addr->v6.sin6_flowinfo = 0;
 780                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 781                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 782                 else
 783                         addr->v6.sin6_scope_id = 0;
 784                 addr->v6.sin6_port = htons(asoc->peer.port);
 785                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 786         }
 787
 788         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 789 }
 790
 791 /* Initialize a msg_name from an inbound skb. */
 792 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 793                                    int *addr_len)
 794 {
 795         union sctp_addr *addr;
 796         struct sctphdr *sh;
 797
 798         if (!msgname)
 799                 return;
 800
 801         addr = (union sctp_addr *)msgname;
 802         sh = sctp_hdr(skb);
 803
 804         if (ip_hdr(skb)->version == 4) {
 805                 addr->v4.sin_family = AF_INET;
 806                 addr->v4.sin_port = sh->source;
 807                 addr->v4.sin_addr.s_addr =  ip_hdr(skb)->saddr;
 808         } else {
 809                 addr->v6.sin6_family = AF_INET6;
 810                 addr->v6.sin6_flowinfo = 0;
 811                 addr->v6.sin6_port = sh->source;
 812                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 813                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 814                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 815                         addr->v6.sin6_scope_id = ev->iif;
 816                 } else {
 817                         addr->v6.sin6_scope_id = 0;
 818                 }
 819         }
 820
 821         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 822 }
 823
 824 /* Do we support this AF? */
 825 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 826 {
 827         switch (family) {
 828         case AF_INET6:
 829                 return 1;
 830         /* v4-mapped-v6 addresses */
 831         case AF_INET:
 832                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 833                         return 1;
 834         default:
 835                 return 0;
 836         }
 837 }
 838
 839 /* Address matching with wildcards allowed.  This extra level
 840  * of indirection lets us choose whether a PF_INET6 should
 841  * disallow any v4 addresses if we so choose.
 842  */
 843 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 844                                const union sctp_addr *addr2,
 845                                struct sctp_sock *opt)
 846 {
 847         struct sock *sk = sctp_opt2sk(opt);
 848         struct sctp_af *af1, *af2;
 849
 850         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 851         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 852
 853         if (!af1 || !af2)
 854                 return 0;
 855
 856         /* If the socket is IPv6 only, v4 addrs will not match */
 857         if (__ipv6_only_sock(sk) && af1 != af2)
 858                 return 0;
 859
 860         /* Today, wildcard AF_INET/AF_INET6. */
 861         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 862                 return 1;
 863
 864         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 865                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 866
 867         return __sctp_v6_cmp_addr(addr1, addr2);
 868 }
 869
 870 /* Verify that the provided sockaddr looks bindable.   Common verification,
 871  * has already been taken care of.
 872  */
 873 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 874 {
 875         struct sctp_af *af;
 876
 877         /* ASSERT: address family has already been verified. */
 878         if (addr->sa.sa_family != AF_INET6)
 879                 af = sctp_get_af_specific(addr->sa.sa_family);
 880         else {
 881                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 882                 struct net_device *dev;
 883
 884                 if (type & IPV6_ADDR_LINKLOCAL) {
 885                         struct net *net;
 886                         if (!addr->v6.sin6_scope_id)
 887                                 return 0;
 888                         net = sock_net(&opt->inet.sk);
 889                         rcu_read_lock();
 890                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 891                         if (!dev ||
 892                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 893                                 rcu_read_unlock();
 894                                 return 0;
 895                         }
 896                         rcu_read_unlock();
 897                 }
 898
 899                 af = opt->pf->af;
 900         }
 901         return af->available(addr, opt);
 902 }
 903
 904 /* Verify that the provided sockaddr looks sendable.   Common verification,
 905  * has already been taken care of.
 906  */
 907 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 908 {
 909         struct sctp_af *af = NULL;
 910
 911         /* ASSERT: address family has already been verified. */
 912         if (addr->sa.sa_family != AF_INET6)
 913                 af = sctp_get_af_specific(addr->sa.sa_family);
 914         else {
 915                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 916                 struct net_device *dev;
 917
 918                 if (type & IPV6_ADDR_LINKLOCAL) {
 919                         if (!addr->v6.sin6_scope_id)
 920                                 return 0;
 921                         rcu_read_lock();
 922                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 923                                                    addr->v6.sin6_scope_id);
 924                         rcu_read_unlock();
 925                         if (!dev)
 926                                 return 0;
 927                 }
 928                 af = opt->pf->af;
 929         }
 930
 931         return af != NULL;
 932 }
 933
 934 /* Fill in Supported Address Type information for INIT and INIT-ACK
 935  * chunks.   Note: In the future, we may want to look at sock options
 936  * to determine whether a PF_INET6 socket really wants to have IPV4
 937  * addresses.
 938  * Returns number of addresses supported.
 939  */
 940 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 941                                       __be16 *types)
 942 {
 943         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 944         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 945                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 946                 return 2;
 947         }
 948         return 1;
 949 }
 950
 951 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 952 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 953                         int *uaddr_len, int peer)
 954 {
 955         int rc;
 956
 957         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 958
 959         if (rc != 0)
 960                 return rc;
 961
 962         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 963                                           (union sctp_addr *)uaddr);
 964
 965         return rc;
 966 }
 967
 968 static const struct proto_ops inet6_seqpacket_ops = {
 969         .family            = PF_INET6,
 970         .owner             = THIS_MODULE,
 971         .release           = inet6_release,
 972         .bind              = inet6_bind,
 973         .connect           = sctp_inet_connect,
 974         .socketpair        = sock_no_socketpair,
 975         .accept            = inet_accept,
 976         .getname           = sctp_getname,
 977         .poll              = sctp_poll,
 978         .ioctl             = inet6_ioctl,
 979         .listen            = sctp_inet_listen,
 980         .shutdown          = inet_shutdown,
 981         .setsockopt        = sock_common_setsockopt,
 982         .getsockopt        = sock_common_getsockopt,
 983         .sendmsg           = inet_sendmsg,
 984         .recvmsg           = sock_common_recvmsg,
 985         .mmap              = sock_no_mmap,
 986 #ifdef CONFIG_COMPAT
 987         .compat_setsockopt = compat_sock_common_setsockopt,
 988         .compat_getsockopt = compat_sock_common_getsockopt,
 989 #endif
 990 };
 991
 992 static struct inet_protosw sctpv6_seqpacket_protosw = {
 993         .type          = SOCK_SEQPACKET,
 994         .protocol      = IPPROTO_SCTP,
 995         .prot          = &sctpv6_prot,
 996         .ops           = &inet6_seqpacket_ops,
 997         .flags         = SCTP_PROTOSW_FLAG
 998 };
 999 static struct inet_protosw sctpv6_stream_protosw = {
1000         .type          = SOCK_STREAM,
1001         .protocol      = IPPROTO_SCTP,
1002         .prot          = &sctpv6_prot,
1003         .ops           = &inet6_seqpacket_ops,
1004         .flags         = SCTP_PROTOSW_FLAG,
1005 };
1006
1007 static int sctp6_rcv(struct sk_buff *skb)
1008 {
1009         return sctp_rcv(skb) ? -1 : 0;
1010 }
1011
1012 static const struct inet6_protocol sctpv6_protocol = {
1013         .handler      = sctp6_rcv,
1014         .err_handler  = sctp_v6_err,
1015         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1016 };
1017
1018 static struct sctp_af sctp_af_inet6 = {
1019         .sa_family         = AF_INET6,
1020         .sctp_xmit         = sctp_v6_xmit,
1021         .setsockopt        = ipv6_setsockopt,
1022         .getsockopt        = ipv6_getsockopt,
1023         .get_dst           = sctp_v6_get_dst,
1024         .get_saddr         = sctp_v6_get_saddr,
1025         .copy_addrlist     = sctp_v6_copy_addrlist,
1026         .from_skb          = sctp_v6_from_skb,
1027         .from_sk           = sctp_v6_from_sk,
1028         .from_addr_param   = sctp_v6_from_addr_param,
1029         .to_addr_param     = sctp_v6_to_addr_param,
1030         .cmp_addr          = sctp_v6_cmp_addr,
1031         .scope             = sctp_v6_scope,
1032         .addr_valid        = sctp_v6_addr_valid,
1033         .inaddr_any        = sctp_v6_inaddr_any,
1034         .is_any            = sctp_v6_is_any,
1035         .available         = sctp_v6_available,
1036         .skb_iif           = sctp_v6_skb_iif,
1037         .is_ce             = sctp_v6_is_ce,
1038         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1039         .ecn_capable       = sctp_v6_ecn_capable,
1040         .net_header_len    = sizeof(struct ipv6hdr),
1041         .sockaddr_len      = sizeof(struct sockaddr_in6),
1042 #ifdef CONFIG_COMPAT
1043         .compat_setsockopt = compat_ipv6_setsockopt,
1044         .compat_getsockopt = compat_ipv6_getsockopt,
1045 #endif
1046 };
1047
1048 static struct sctp_pf sctp_pf_inet6 = {
1049         .event_msgname = sctp_inet6_event_msgname,
1050         .skb_msgname   = sctp_inet6_skb_msgname,
1051         .af_supported  = sctp_inet6_af_supported,
1052         .cmp_addr      = sctp_inet6_cmp_addr,
1053         .bind_verify   = sctp_inet6_bind_verify,
1054         .send_verify   = sctp_inet6_send_verify,
1055         .supported_addrs = sctp_inet6_supported_addrs,
1056         .create_accept_sk = sctp_v6_create_accept_sk,
1057         .addr_to_user  = sctp_v6_addr_to_user,
1058         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1059         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1060         .af            = &sctp_af_inet6,
1061 };
1062
1063 /* Initialize IPv6 support and register with socket layer.  */
1064 void sctp_v6_pf_init(void)
1065 {
1066         /* Register the SCTP specific PF_INET6 functions. */
1067         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1068
1069         /* Register the SCTP specific AF_INET6 functions. */
1070         sctp_register_af(&sctp_af_inet6);
1071 }
1072
1073 void sctp_v6_pf_exit(void)
1074 {
1075         list_del(&sctp_af_inet6.list);
1076 }
1077
1078 /* Initialize IPv6 support and register with socket layer.  */
1079 int sctp_v6_protosw_init(void)
1080 {
1081         int rc;
1082
1083         rc = proto_register(&sctpv6_prot, 1);
1084         if (rc)
1085                 return rc;
1086
1087         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1088         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1089         inet6_register_protosw(&sctpv6_stream_protosw);
1090
1091         return 0;
1092 }
1093
1094 void sctp_v6_protosw_exit(void)
1095 {
1096         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1097         inet6_unregister_protosw(&sctpv6_stream_protosw);
1098         proto_unregister(&sctpv6_prot);
1099 }
1100
1101
1102 /* Register with inet6 layer. */
1103 int sctp_v6_add_protocol(void)
1104 {
1105         /* Register notifier for inet6 address additions/deletions. */
1106         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1107
1108         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1109                 return -EAGAIN;
1110
1111         return 0;
1112 }
1113
1114 /* Unregister with inet6 layer. */
1115 void sctp_v6_del_protocol(void)
1116 {
1117         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1118         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1119 }