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 = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 101                 if (addr) {
 102                         addr->a.v6.sin6_family = AF_INET6;
 103                         addr->a.v6.sin6_port = 0;
 104                         addr->a.v6.sin6_addr = ifa->addr;
 105                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 106                         addr->valid = 1;
 107                         spin_lock_bh(&net->sctp.local_addr_lock);
 108                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 109                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 110                         spin_unlock_bh(&net->sctp.local_addr_lock);
 111                 }
 112                 break;
 113         case NETDEV_DOWN:
 114                 spin_lock_bh(&net->sctp.local_addr_lock);
 115                 list_for_each_entry_safe(addr, temp,
 116                                         &net->sctp.local_addr_list, list) {
 117                         if (addr->a.sa.sa_family == AF_INET6 &&
 118                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 119                                                 &ifa->addr)) {
 120                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 121                                 found = 1;
 122                                 addr->valid = 0;
 123                                 list_del_rcu(&addr->list);
 124                                 break;
 125                         }
 126                 }
 127                 spin_unlock_bh(&net->sctp.local_addr_lock);
 128                 if (found)
 129                         kfree_rcu(addr, rcu);
 130                 break;
 131         }
 132
 133         return NOTIFY_DONE;
 134 }
 135
 136 static struct notifier_block sctp_inet6addr_notifier = {
 137         .notifier_call = sctp_inet6addr_event,
 138 };
 139
 140 /* ICMP error handler. */
 141 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 142                         u8 type, u8 code, int offset, __be32 info)
 143 {
 144         struct inet6_dev *idev;
 145         struct sock *sk;
 146         struct sctp_association *asoc;
 147         struct sctp_transport *transport;
 148         struct ipv6_pinfo *np;
 149         __u16 saveip, savesctp;
 150         int err;
 151         struct net *net = dev_net(skb->dev);
 152
 153         idev = in6_dev_get(skb->dev);
 154
 155         /* Fix up skb to look at the embedded net header. */
 156         saveip   = skb->network_header;
 157         savesctp = skb->transport_header;
 158         skb_reset_network_header(skb);
 159         skb_set_transport_header(skb, offset);
 160         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 161         /* Put back, the original pointers. */
 162         skb->network_header   = saveip;
 163         skb->transport_header = savesctp;
 164         if (!sk) {
 165                 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_INERRORS);
 166                 goto out;
 167         }
 168
 169         /* Warning:  The sock lock is held.  Remember to call
 170          * sctp_err_finish!
 171          */
 172
 173         switch (type) {
 174         case ICMPV6_PKT_TOOBIG:
 175                 if (ip6_sk_accept_pmtu(sk))
 176                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 177                 goto out_unlock;
 178         case ICMPV6_PARAMPROB:
 179                 if (ICMPV6_UNK_NEXTHDR == code) {
 180                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 181                         goto out_unlock;
 182                 }
 183                 break;
 184         case NDISC_REDIRECT:
 185                 sctp_icmp_redirect(sk, transport, skb);
 186                 goto out_unlock;
 187         default:
 188                 break;
 189         }
 190
 191         np = inet6_sk(sk);
 192         icmpv6_err_convert(type, code, &err);
 193         if (!sock_owned_by_user(sk) && np->recverr) {
 194                 sk->sk_err = err;
 195                 sk->sk_error_report(sk);
 196         } else {  /* Only an error on timeout */
 197                 sk->sk_err_soft = err;
 198         }
 199
 200 out_unlock:
 201         sctp_err_finish(sk, asoc);
 202 out:
 203         if (likely(idev != NULL))
 204                 in6_dev_put(idev);
 205 }
 206
 207 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 208 {
 209         struct sock *sk = skb->sk;
 210         struct ipv6_pinfo *np = inet6_sk(sk);
 211         struct flowi6 *fl6 = &transport->fl.u.ip6;
 212         int res;
 213
 214         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 215                  skb->len, &fl6->saddr, &fl6->daddr);
 216
 217         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 218
 219         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 220                 skb->ignore_df = 1;
 221
 222         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 223
 224         rcu_read_lock();
 225         res = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt), np->tclass);
 226         rcu_read_unlock();
 227         return res;
 228 }
 229
 230 /* Returns the dst cache entry for the given source and destination ip
 231  * addresses.
 232  */
 233 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 234                             struct flowi *fl, struct sock *sk)
 235 {
 236         struct sctp_association *asoc = t->asoc;
 237         struct dst_entry *dst = NULL;
 238         struct flowi6 *fl6 = &fl->u.ip6;
 239         struct sctp_bind_addr *bp;
 240         struct ipv6_pinfo *np = inet6_sk(sk);
 241         struct sctp_sockaddr_entry *laddr;
 242         union sctp_addr *daddr = &t->ipaddr;
 243         union sctp_addr dst_saddr;
 244         struct in6_addr *final_p, final;
 245         __u8 matchlen = 0;
 246         sctp_scope_t scope;
 247
 248         memset(fl6, 0, sizeof(struct flowi6));
 249         fl6->daddr = daddr->v6.sin6_addr;
 250         fl6->fl6_dport = daddr->v6.sin6_port;
 251         fl6->flowi6_proto = IPPROTO_SCTP;
 252         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 253                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 254
 255         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 256
 257         if (asoc)
 258                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 259
 260         if (saddr) {
 261                 fl6->saddr = saddr->v6.sin6_addr;
 262                 fl6->fl6_sport = saddr->v6.sin6_port;
 263
 264                 pr_debug("src=%pI6 - ", &fl6->saddr);
 265         }
 266
 267         rcu_read_lock();
 268         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 269         rcu_read_unlock();
 270
 271         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 272         if (!asoc || saddr)
 273                 goto out;
 274
 275         bp = &asoc->base.bind_addr;
 276         scope = sctp_scope(daddr);
 277         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 278          * to see if we can use it.
 279          */
 280         if (!IS_ERR(dst)) {
 281                 /* Walk through the bind address list and look for a bind
 282                  * address that matches the source address of the returned dst.
 283                  */
 284                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 285                 rcu_read_lock();
 286                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 287                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 288                             (laddr->state != SCTP_ADDR_SRC &&
 289                              !asoc->src_out_of_asoc_ok))
 290                                 continue;
 291
 292                         /* Do not compare against v4 addrs */
 293                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 294                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 295                                 rcu_read_unlock();
 296                                 goto out;
 297                         }
 298                 }
 299                 rcu_read_unlock();
 300                 /* None of the bound addresses match the source address of the
 301                  * dst. So release it.
 302                  */
 303                 dst_release(dst);
 304                 dst = NULL;
 305         }
 306
 307         /* Walk through the bind address list and try to get the
 308          * best source address for a given destination.
 309          */
 310         rcu_read_lock();
 311         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 312                 struct dst_entry *bdst;
 313                 __u8 bmatchlen;
 314
 315                 if (!laddr->valid ||
 316                     laddr->state != SCTP_ADDR_SRC ||
 317                     laddr->a.sa.sa_family != AF_INET6 ||
 318                     scope > sctp_scope(&laddr->a))
 319                         continue;
 320
 321                 fl6->saddr = laddr->a.v6.sin6_addr;
 322                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 323                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 324                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 325
 326                 if (!IS_ERR(bdst) &&
 327                     ipv6_chk_addr(dev_net(bdst->dev),
 328                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 329                         if (!IS_ERR_OR_NULL(dst))
 330                                 dst_release(dst);
 331                         dst = bdst;
 332                         break;
 333                 }
 334
 335                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 336                 if (matchlen > bmatchlen)
 337                         continue;
 338
 339                 if (!IS_ERR_OR_NULL(dst))
 340                         dst_release(dst);
 341                 dst = bdst;
 342                 matchlen = bmatchlen;
 343         }
 344         rcu_read_unlock();
 345
 346 out:
 347         if (!IS_ERR_OR_NULL(dst)) {
 348                 struct rt6_info *rt;
 349
 350                 rt = (struct rt6_info *)dst;
 351                 t->dst = dst;
 352                 t->dst_cookie = rt6_get_cookie(rt);
 353                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 354                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 355                          &fl6->saddr);
 356         } else {
 357                 t->dst = NULL;
 358
 359                 pr_debug("no route\n");
 360         }
 361 }
 362
 363 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 364  * addresses.
 365  */
 366 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 367                                          union sctp_addr *s2)
 368 {
 369         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 370 }
 371
 372 /* Fills in the source address(saddr) based on the destination address(daddr)
 373  * and asoc's bind address list.
 374  */
 375 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 376                               struct sctp_transport *t,
 377                               struct flowi *fl)
 378 {
 379         struct flowi6 *fl6 = &fl->u.ip6;
 380         union sctp_addr *saddr = &t->saddr;
 381
 382         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 383
 384         if (t->dst) {
 385                 saddr->v6.sin6_family = AF_INET6;
 386                 saddr->v6.sin6_addr = fl6->saddr;
 387         }
 388 }
 389
 390 /* Make a copy of all potential local addresses. */
 391 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 392                                   struct net_device *dev)
 393 {
 394         struct inet6_dev *in6_dev;
 395         struct inet6_ifaddr *ifp;
 396         struct sctp_sockaddr_entry *addr;
 397
 398         rcu_read_lock();
 399         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 400                 rcu_read_unlock();
 401                 return;
 402         }
 403
 404         read_lock_bh(&in6_dev->lock);
 405         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 406                 /* Add the address to the local list.  */
 407                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 408                 if (addr) {
 409                         addr->a.v6.sin6_family = AF_INET6;
 410                         addr->a.v6.sin6_port = 0;
 411                         addr->a.v6.sin6_addr = ifp->addr;
 412                         addr->a.v6.sin6_scope_id = dev->ifindex;
 413                         addr->valid = 1;
 414                         INIT_LIST_HEAD(&addr->list);
 415                         list_add_tail(&addr->list, addrlist);
 416                 }
 417         }
 418
 419         read_unlock_bh(&in6_dev->lock);
 420         rcu_read_unlock();
 421 }
 422
 423 /* Initialize a sockaddr_storage from in incoming skb. */
 424 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 425                              int is_saddr)
 426 {
 427         __be16 *port;
 428         struct sctphdr *sh;
 429
 430         port = &addr->v6.sin6_port;
 431         addr->v6.sin6_family = AF_INET6;
 432         addr->v6.sin6_flowinfo = 0; /* FIXME */
 433         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 434
 435         sh = sctp_hdr(skb);
 436         if (is_saddr) {
 437                 *port  = sh->source;
 438                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 439         } else {
 440                 *port = sh->dest;
 441                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 442         }
 443 }
 444
 445 /* Initialize an sctp_addr from a socket. */
 446 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 447 {
 448         addr->v6.sin6_family = AF_INET6;
 449         addr->v6.sin6_port = 0;
 450         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 451 }
 452
 453 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 454 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 455 {
 456         if (addr->sa.sa_family == AF_INET) {
 457                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 458                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 459                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 460                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 461                         addr->v4.sin_addr.s_addr;
 462         } else {
 463                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 464         }
 465 }
 466
 467 /* Initialize sk->sk_daddr from sctp_addr. */
 468 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 469 {
 470         if (addr->sa.sa_family == AF_INET) {
 471                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 472                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 473                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 474                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 475         } else {
 476                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 477         }
 478 }
 479
 480 /* Initialize a sctp_addr from an address parameter. */
 481 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 482                                     union sctp_addr_param *param,
 483                                     __be16 port, int iif)
 484 {
 485         addr->v6.sin6_family = AF_INET6;
 486         addr->v6.sin6_port = port;
 487         addr->v6.sin6_flowinfo = 0; /* BUG */
 488         addr->v6.sin6_addr = param->v6.addr;
 489         addr->v6.sin6_scope_id = iif;
 490 }
 491
 492 /* Initialize an address parameter from a sctp_addr and return the length
 493  * of the address parameter.
 494  */
 495 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 496                                  union sctp_addr_param *param)
 497 {
 498         int length = sizeof(sctp_ipv6addr_param_t);
 499
 500         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 501         param->v6.param_hdr.length = htons(length);
 502         param->v6.addr = addr->v6.sin6_addr;
 503
 504         return length;
 505 }
 506
 507 /* Initialize a sctp_addr from struct in6_addr. */
 508 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 509                               __be16 port)
 510 {
 511         addr->sa.sa_family = AF_INET6;
 512         addr->v6.sin6_port = port;
 513         addr->v6.sin6_addr = *saddr;
 514 }
 515
 516 /* Compare addresses exactly.
 517  * v4-mapped-v6 is also in consideration.
 518  */
 519 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 520                             const union sctp_addr *addr2)
 521 {
 522         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 523                 if (addr1->sa.sa_family == AF_INET &&
 524                     addr2->sa.sa_family == AF_INET6 &&
 525                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 526                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 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                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 535                             addr1->v6.sin6_addr.s6_addr32[3] ==
 536                             addr2->v4.sin_addr.s_addr)
 537                                 return 1;
 538                 }
 539                 return 0;
 540         }
 541         if (addr1->v6.sin6_port != addr2->v6.sin6_port)
 542                 return 0;
 543         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 544                 return 0;
 545         /* If this is a linklocal address, compare the scope_id. */
 546         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 547                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 548                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 549                         return 0;
 550                 }
 551         }
 552
 553         return 1;
 554 }
 555
 556 /* Initialize addr struct to INADDR_ANY. */
 557 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 558 {
 559         memset(addr, 0x00, sizeof(union sctp_addr));
 560         addr->v6.sin6_family = AF_INET6;
 561         addr->v6.sin6_port = port;
 562 }
 563
 564 /* Is this a wildcard address? */
 565 static int sctp_v6_is_any(const union sctp_addr *addr)
 566 {
 567         return ipv6_addr_any(&addr->v6.sin6_addr);
 568 }
 569
 570 /* Should this be available for binding?   */
 571 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 572 {
 573         int type;
 574         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 575
 576         type = ipv6_addr_type(in6);
 577         if (IPV6_ADDR_ANY == type)
 578                 return 1;
 579         if (type == IPV6_ADDR_MAPPED) {
 580                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 581                         return 0;
 582                 sctp_v6_map_v4(addr);
 583                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 584         }
 585         if (!(type & IPV6_ADDR_UNICAST))
 586                 return 0;
 587
 588         return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
 589 }
 590
 591 /* This function checks if the address is a valid address to be used for
 592  * SCTP.
 593  *
 594  * Output:
 595  * Return 0 - If the address is a non-unicast or an illegal address.
 596  * Return 1 - If the address is a unicast.
 597  */
 598 static int sctp_v6_addr_valid(union sctp_addr *addr,
 599                               struct sctp_sock *sp,
 600                               const struct sk_buff *skb)
 601 {
 602         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 603
 604         /* Support v4-mapped-v6 address. */
 605         if (ret == IPV6_ADDR_MAPPED) {
 606                 /* Note: This routine is used in input, so v4-mapped-v6
 607                  * are disallowed here when there is no sctp_sock.
 608                  */
 609                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 610                         return 0;
 611                 sctp_v6_map_v4(addr);
 612                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 613         }
 614
 615         /* Is this a non-unicast address */
 616         if (!(ret & IPV6_ADDR_UNICAST))
 617                 return 0;
 618
 619         return 1;
 620 }
 621
 622 /* What is the scope of 'addr'?  */
 623 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 624 {
 625         int v6scope;
 626         sctp_scope_t retval;
 627
 628         /* The IPv6 scope is really a set of bit fields.
 629          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 630          */
 631
 632         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 633         switch (v6scope) {
 634         case IFA_HOST:
 635                 retval = SCTP_SCOPE_LOOPBACK;
 636                 break;
 637         case IFA_LINK:
 638                 retval = SCTP_SCOPE_LINK;
 639                 break;
 640         case IFA_SITE:
 641                 retval = SCTP_SCOPE_PRIVATE;
 642                 break;
 643         default:
 644                 retval = SCTP_SCOPE_GLOBAL;
 645                 break;
 646         }
 647
 648         return retval;
 649 }
 650
 651 /* Create and initialize a new sk for the socket to be returned by accept(). */
 652 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 653                                              struct sctp_association *asoc)
 654 {
 655         struct sock *newsk;
 656         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 657         struct sctp6_sock *newsctp6sk;
 658         struct ipv6_txoptions *opt;
 659
 660         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0);
 661         if (!newsk)
 662                 goto out;
 663
 664         sock_init_data(NULL, newsk);
 665
 666         sctp_copy_sock(newsk, sk, asoc);
 667         sock_reset_flag(sk, SOCK_ZAPPED);
 668
 669         newsctp6sk = (struct sctp6_sock *)newsk;
 670         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 671
 672         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 673
 674         newnp = inet6_sk(newsk);
 675
 676         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 677         newnp->ipv6_mc_list = NULL;
 678         newnp->ipv6_ac_list = NULL;
 679         newnp->ipv6_fl_list = NULL;
 680
 681         rcu_read_lock();
 682         opt = rcu_dereference(np->opt);
 683         if (opt)
 684                 opt = ipv6_dup_options(newsk, opt);
 685         RCU_INIT_POINTER(newnp->opt, opt);
 686         rcu_read_unlock();
 687
 688         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 689          * and getpeername().
 690          */
 691         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 692
 693         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 694
 695         sk_refcnt_debug_inc(newsk);
 696
 697         if (newsk->sk_prot->init(newsk)) {
 698                 sk_common_release(newsk);
 699                 newsk = NULL;
 700         }
 701
 702 out:
 703         return newsk;
 704 }
 705
 706 /* Format a sockaddr for return to user space. This makes sure the return is
 707  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 708  */
 709 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 710 {
 711         if (sp->v4mapped) {
 712                 if (addr->sa.sa_family == AF_INET)
 713                         sctp_v4_map_v6(addr);
 714         } else {
 715                 if (addr->sa.sa_family == AF_INET6 &&
 716                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 717                         sctp_v6_map_v4(addr);
 718         }
 719
 720         if (addr->sa.sa_family == AF_INET)
 721                 return sizeof(struct sockaddr_in);
 722         return sizeof(struct sockaddr_in6);
 723 }
 724
 725 /* Where did this skb come from?  */
 726 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 727 {
 728         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 729         return opt->iif;
 730 }
 731
 732 /* Was this packet marked by Explicit Congestion Notification? */
 733 static int sctp_v6_is_ce(const struct sk_buff *skb)
 734 {
 735         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 736 }
 737
 738 /* Dump the v6 addr to the seq file. */
 739 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 740 {
 741         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 742 }
 743
 744 static void sctp_v6_ecn_capable(struct sock *sk)
 745 {
 746         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 747 }
 748
 749 /* Initialize a PF_INET msgname from a ulpevent. */
 750 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 751                                      char *msgname, int *addrlen)
 752 {
 753         union sctp_addr *addr;
 754         struct sctp_association *asoc;
 755         union sctp_addr *paddr;
 756
 757         if (!msgname)
 758                 return;
 759
 760         addr = (union sctp_addr *)msgname;
 761         asoc = event->asoc;
 762         paddr = &asoc->peer.primary_addr;
 763
 764         if (paddr->sa.sa_family == AF_INET) {
 765                 addr->v4.sin_family = AF_INET;
 766                 addr->v4.sin_port = htons(asoc->peer.port);
 767                 addr->v4.sin_addr = paddr->v4.sin_addr;
 768         } else {
 769                 addr->v6.sin6_family = AF_INET6;
 770                 addr->v6.sin6_flowinfo = 0;
 771                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 772                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 773                 else
 774                         addr->v6.sin6_scope_id = 0;
 775                 addr->v6.sin6_port = htons(asoc->peer.port);
 776                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 777         }
 778
 779         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 780 }
 781
 782 /* Initialize a msg_name from an inbound skb. */
 783 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 784                                    int *addr_len)
 785 {
 786         union sctp_addr *addr;
 787         struct sctphdr *sh;
 788
 789         if (!msgname)
 790                 return;
 791
 792         addr = (union sctp_addr *)msgname;
 793         sh = sctp_hdr(skb);
 794
 795         if (ip_hdr(skb)->version == 4) {
 796                 addr->v4.sin_family = AF_INET;
 797                 addr->v4.sin_port = sh->source;
 798                 addr->v4.sin_addr.s_addr =  ip_hdr(skb)->saddr;
 799         } else {
 800                 addr->v6.sin6_family = AF_INET6;
 801                 addr->v6.sin6_flowinfo = 0;
 802                 addr->v6.sin6_port = sh->source;
 803                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 804                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 805                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 806                         addr->v6.sin6_scope_id = ev->iif;
 807                 }
 808         }
 809
 810         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 811 }
 812
 813 /* Do we support this AF? */
 814 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 815 {
 816         switch (family) {
 817         case AF_INET6:
 818                 return 1;
 819         /* v4-mapped-v6 addresses */
 820         case AF_INET:
 821                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 822                         return 1;
 823         default:
 824                 return 0;
 825         }
 826 }
 827
 828 /* Address matching with wildcards allowed.  This extra level
 829  * of indirection lets us choose whether a PF_INET6 should
 830  * disallow any v4 addresses if we so choose.
 831  */
 832 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 833                                const union sctp_addr *addr2,
 834                                struct sctp_sock *opt)
 835 {
 836         struct sctp_af *af1, *af2;
 837         struct sock *sk = sctp_opt2sk(opt);
 838
 839         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 840         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 841
 842         if (!af1 || !af2)
 843                 return 0;
 844
 845         /* If the socket is IPv6 only, v4 addrs will not match */
 846         if (__ipv6_only_sock(sk) && af1 != af2)
 847                 return 0;
 848
 849         /* Today, wildcard AF_INET/AF_INET6. */
 850         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 851                 return 1;
 852
 853         if (addr1->sa.sa_family != addr2->sa.sa_family)
 854                 return 0;
 855
 856         return af1->cmp_addr(addr1, addr2);
 857 }
 858
 859 /* Verify that the provided sockaddr looks bindable.   Common verification,
 860  * has already been taken care of.
 861  */
 862 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 863 {
 864         struct sctp_af *af;
 865
 866         /* ASSERT: address family has already been verified. */
 867         if (addr->sa.sa_family != AF_INET6)
 868                 af = sctp_get_af_specific(addr->sa.sa_family);
 869         else {
 870                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 871                 struct net_device *dev;
 872
 873                 if (type & IPV6_ADDR_LINKLOCAL) {
 874                         struct net *net;
 875                         if (!addr->v6.sin6_scope_id)
 876                                 return 0;
 877                         net = sock_net(&opt->inet.sk);
 878                         rcu_read_lock();
 879                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 880                         if (!dev ||
 881                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 882                                 rcu_read_unlock();
 883                                 return 0;
 884                         }
 885                         rcu_read_unlock();
 886                 }
 887
 888                 af = opt->pf->af;
 889         }
 890         return af->available(addr, opt);
 891 }
 892
 893 /* Verify that the provided sockaddr looks sendable.   Common verification,
 894  * has already been taken care of.
 895  */
 896 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 897 {
 898         struct sctp_af *af = NULL;
 899
 900         /* ASSERT: address family has already been verified. */
 901         if (addr->sa.sa_family != AF_INET6)
 902                 af = sctp_get_af_specific(addr->sa.sa_family);
 903         else {
 904                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 905                 struct net_device *dev;
 906
 907                 if (type & IPV6_ADDR_LINKLOCAL) {
 908                         if (!addr->v6.sin6_scope_id)
 909                                 return 0;
 910                         rcu_read_lock();
 911                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 912                                                    addr->v6.sin6_scope_id);
 913                         rcu_read_unlock();
 914                         if (!dev)
 915                                 return 0;
 916                 }
 917                 af = opt->pf->af;
 918         }
 919
 920         return af != NULL;
 921 }
 922
 923 /* Fill in Supported Address Type information for INIT and INIT-ACK
 924  * chunks.   Note: In the future, we may want to look at sock options
 925  * to determine whether a PF_INET6 socket really wants to have IPV4
 926  * addresses.
 927  * Returns number of addresses supported.
 928  */
 929 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 930                                       __be16 *types)
 931 {
 932         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 933         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 934                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 935                 return 2;
 936         }
 937         return 1;
 938 }
 939
 940 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 941 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 942                         int *uaddr_len, int peer)
 943 {
 944         int rc;
 945
 946         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 947
 948         if (rc != 0)
 949                 return rc;
 950
 951         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 952                                           (union sctp_addr *)uaddr);
 953
 954         return rc;
 955 }
 956
 957 static const struct proto_ops inet6_seqpacket_ops = {
 958         .family            = PF_INET6,
 959         .owner             = THIS_MODULE,
 960         .release           = inet6_release,
 961         .bind              = inet6_bind,
 962         .connect           = inet_dgram_connect,
 963         .socketpair        = sock_no_socketpair,
 964         .accept            = inet_accept,
 965         .getname           = sctp_getname,
 966         .poll              = sctp_poll,
 967         .ioctl             = inet6_ioctl,
 968         .listen            = sctp_inet_listen,
 969         .shutdown          = inet_shutdown,
 970         .setsockopt        = sock_common_setsockopt,
 971         .getsockopt        = sock_common_getsockopt,
 972         .sendmsg           = inet_sendmsg,
 973         .recvmsg           = sock_common_recvmsg,
 974         .mmap              = sock_no_mmap,
 975 #ifdef CONFIG_COMPAT
 976         .compat_setsockopt = compat_sock_common_setsockopt,
 977         .compat_getsockopt = compat_sock_common_getsockopt,
 978 #endif
 979 };
 980
 981 static struct inet_protosw sctpv6_seqpacket_protosw = {
 982         .type          = SOCK_SEQPACKET,
 983         .protocol      = IPPROTO_SCTP,
 984         .prot          = &sctpv6_prot,
 985         .ops           = &inet6_seqpacket_ops,
 986         .flags         = SCTP_PROTOSW_FLAG
 987 };
 988 static struct inet_protosw sctpv6_stream_protosw = {
 989         .type          = SOCK_STREAM,
 990         .protocol      = IPPROTO_SCTP,
 991         .prot          = &sctpv6_prot,
 992         .ops           = &inet6_seqpacket_ops,
 993         .flags         = SCTP_PROTOSW_FLAG,
 994 };
 995
 996 static int sctp6_rcv(struct sk_buff *skb)
 997 {
 998         return sctp_rcv(skb) ? -1 : 0;
 999 }
1000
1001 static const struct inet6_protocol sctpv6_protocol = {
1002         .handler      = sctp6_rcv,
1003         .err_handler  = sctp_v6_err,
1004         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1005 };
1006
1007 static struct sctp_af sctp_af_inet6 = {
1008         .sa_family         = AF_INET6,
1009         .sctp_xmit         = sctp_v6_xmit,
1010         .setsockopt        = ipv6_setsockopt,
1011         .getsockopt        = ipv6_getsockopt,
1012         .get_dst           = sctp_v6_get_dst,
1013         .get_saddr         = sctp_v6_get_saddr,
1014         .copy_addrlist     = sctp_v6_copy_addrlist,
1015         .from_skb          = sctp_v6_from_skb,
1016         .from_sk           = sctp_v6_from_sk,
1017         .from_addr_param   = sctp_v6_from_addr_param,
1018         .to_addr_param     = sctp_v6_to_addr_param,
1019         .cmp_addr          = sctp_v6_cmp_addr,
1020         .scope             = sctp_v6_scope,
1021         .addr_valid        = sctp_v6_addr_valid,
1022         .inaddr_any        = sctp_v6_inaddr_any,
1023         .is_any            = sctp_v6_is_any,
1024         .available         = sctp_v6_available,
1025         .skb_iif           = sctp_v6_skb_iif,
1026         .is_ce             = sctp_v6_is_ce,
1027         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1028         .ecn_capable       = sctp_v6_ecn_capable,
1029         .net_header_len    = sizeof(struct ipv6hdr),
1030         .sockaddr_len      = sizeof(struct sockaddr_in6),
1031 #ifdef CONFIG_COMPAT
1032         .compat_setsockopt = compat_ipv6_setsockopt,
1033         .compat_getsockopt = compat_ipv6_getsockopt,
1034 #endif
1035 };
1036
1037 static struct sctp_pf sctp_pf_inet6 = {
1038         .event_msgname = sctp_inet6_event_msgname,
1039         .skb_msgname   = sctp_inet6_skb_msgname,
1040         .af_supported  = sctp_inet6_af_supported,
1041         .cmp_addr      = sctp_inet6_cmp_addr,
1042         .bind_verify   = sctp_inet6_bind_verify,
1043         .send_verify   = sctp_inet6_send_verify,
1044         .supported_addrs = sctp_inet6_supported_addrs,
1045         .create_accept_sk = sctp_v6_create_accept_sk,
1046         .addr_to_user  = sctp_v6_addr_to_user,
1047         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1048         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1049         .af            = &sctp_af_inet6,
1050 };
1051
1052 /* Initialize IPv6 support and register with socket layer.  */
1053 void sctp_v6_pf_init(void)
1054 {
1055         /* Register the SCTP specific PF_INET6 functions. */
1056         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1057
1058         /* Register the SCTP specific AF_INET6 functions. */
1059         sctp_register_af(&sctp_af_inet6);
1060 }
1061
1062 void sctp_v6_pf_exit(void)
1063 {
1064         list_del(&sctp_af_inet6.list);
1065 }
1066
1067 /* Initialize IPv6 support and register with socket layer.  */
1068 int sctp_v6_protosw_init(void)
1069 {
1070         int rc;
1071
1072         rc = proto_register(&sctpv6_prot, 1);
1073         if (rc)
1074                 return rc;
1075
1076         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1077         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1078         inet6_register_protosw(&sctpv6_stream_protosw);
1079
1080         return 0;
1081 }
1082
1083 void sctp_v6_protosw_exit(void)
1084 {
1085         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1086         inet6_unregister_protosw(&sctpv6_stream_protosw);
1087         proto_unregister(&sctpv6_prot);
1088 }
1089
1090
1091 /* Register with inet6 layer. */
1092 int sctp_v6_add_protocol(void)
1093 {
1094         /* Register notifier for inet6 address additions/deletions. */
1095         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1096
1097         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1098                 return -EAGAIN;
1099
1100         return 0;
1101 }
1102
1103 /* Unregister with inet6 layer. */
1104 void sctp_v6_del_protocol(void)
1105 {
1106         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1107         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1108 }