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 <linux/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(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, transport);
 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, sk->sk_mark, rcu_dereference(np->opt),
 226                        np->tclass);
 227         rcu_read_unlock();
 228         return res;
 229 }
 230
 231 /* Returns the dst cache entry for the given source and destination ip
 232  * addresses.
 233  */
 234 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 235                             struct flowi *fl, struct sock *sk)
 236 {
 237         struct sctp_association *asoc = t->asoc;
 238         struct dst_entry *dst = NULL;
 239         struct flowi6 *fl6 = &fl->u.ip6;
 240         struct sctp_bind_addr *bp;
 241         struct ipv6_pinfo *np = inet6_sk(sk);
 242         struct sctp_sockaddr_entry *laddr;
 243         union sctp_addr *baddr = NULL;
 244         union sctp_addr *daddr = &t->ipaddr;
 245         union sctp_addr dst_saddr;
 246         struct in6_addr *final_p, final;
 247         __u8 matchlen = 0;
 248         __u8 bmatchlen;
 249         sctp_scope_t scope;
 250
 251         memset(fl6, 0, sizeof(struct flowi6));
 252         fl6->daddr = daddr->v6.sin6_addr;
 253         fl6->fl6_dport = daddr->v6.sin6_port;
 254         fl6->flowi6_proto = IPPROTO_SCTP;
 255         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 256                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 257
 258         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 259
 260         if (asoc)
 261                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 262
 263         if (saddr) {
 264                 fl6->saddr = saddr->v6.sin6_addr;
 265                 fl6->fl6_sport = saddr->v6.sin6_port;
 266
 267                 pr_debug("src=%pI6 - ", &fl6->saddr);
 268         }
 269
 270         rcu_read_lock();
 271         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 272         rcu_read_unlock();
 273
 274         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 275         if (!asoc || saddr)
 276                 goto out;
 277
 278         bp = &asoc->base.bind_addr;
 279         scope = sctp_scope(daddr);
 280         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 281          * to see if we can use it.
 282          */
 283         if (!IS_ERR(dst)) {
 284                 /* Walk through the bind address list and look for a bind
 285                  * address that matches the source address of the returned dst.
 286                  */
 287                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 288                 rcu_read_lock();
 289                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 290                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 291                             (laddr->state != SCTP_ADDR_SRC &&
 292                              !asoc->src_out_of_asoc_ok))
 293                                 continue;
 294
 295                         /* Do not compare against v4 addrs */
 296                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 297                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 298                                 rcu_read_unlock();
 299                                 goto out;
 300                         }
 301                 }
 302                 rcu_read_unlock();
 303                 /* None of the bound addresses match the source address of the
 304                  * dst. So release it.
 305                  */
 306                 dst_release(dst);
 307                 dst = NULL;
 308         }
 309
 310         /* Walk through the bind address list and try to get the
 311          * best source address for a given destination.
 312          */
 313         rcu_read_lock();
 314         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 315                 if (!laddr->valid)
 316                         continue;
 317                 if ((laddr->state == SCTP_ADDR_SRC) &&
 318                     (laddr->a.sa.sa_family == AF_INET6) &&
 319                     (scope <= sctp_scope(&laddr->a))) {
 320                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 321                         if (!baddr || (matchlen < bmatchlen)) {
 322                                 baddr = &laddr->a;
 323                                 matchlen = bmatchlen;
 324                         }
 325                 }
 326         }
 327         if (baddr) {
 328                 fl6->saddr = baddr->v6.sin6_addr;
 329                 fl6->fl6_sport = baddr->v6.sin6_port;
 330                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 331                 dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 332         }
 333         rcu_read_unlock();
 334
 335 out:
 336         if (!IS_ERR_OR_NULL(dst)) {
 337                 struct rt6_info *rt;
 338
 339                 rt = (struct rt6_info *)dst;
 340                 t->dst = dst;
 341                 t->dst_cookie = rt6_get_cookie(rt);
 342                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 343                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 344                          &fl6->saddr);
 345         } else {
 346                 t->dst = NULL;
 347
 348                 pr_debug("no route\n");
 349         }
 350 }
 351
 352 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 353  * addresses.
 354  */
 355 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 356                                          union sctp_addr *s2)
 357 {
 358         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 359 }
 360
 361 /* Fills in the source address(saddr) based on the destination address(daddr)
 362  * and asoc's bind address list.
 363  */
 364 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 365                               struct sctp_transport *t,
 366                               struct flowi *fl)
 367 {
 368         struct flowi6 *fl6 = &fl->u.ip6;
 369         union sctp_addr *saddr = &t->saddr;
 370
 371         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 372
 373         if (t->dst) {
 374                 saddr->v6.sin6_family = AF_INET6;
 375                 saddr->v6.sin6_addr = fl6->saddr;
 376         }
 377 }
 378
 379 /* Make a copy of all potential local addresses. */
 380 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 381                                   struct net_device *dev)
 382 {
 383         struct inet6_dev *in6_dev;
 384         struct inet6_ifaddr *ifp;
 385         struct sctp_sockaddr_entry *addr;
 386
 387         rcu_read_lock();
 388         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 389                 rcu_read_unlock();
 390                 return;
 391         }
 392
 393         read_lock_bh(&in6_dev->lock);
 394         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 395                 /* Add the address to the local list.  */
 396                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 397                 if (addr) {
 398                         addr->a.v6.sin6_family = AF_INET6;
 399                         addr->a.v6.sin6_port = 0;
 400                         addr->a.v6.sin6_addr = ifp->addr;
 401                         addr->a.v6.sin6_scope_id = dev->ifindex;
 402                         addr->valid = 1;
 403                         INIT_LIST_HEAD(&addr->list);
 404                         list_add_tail(&addr->list, addrlist);
 405                 }
 406         }
 407
 408         read_unlock_bh(&in6_dev->lock);
 409         rcu_read_unlock();
 410 }
 411
 412 /* Initialize a sockaddr_storage from in incoming skb. */
 413 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 414                              int is_saddr)
 415 {
 416         __be16 *port;
 417         struct sctphdr *sh;
 418
 419         port = &addr->v6.sin6_port;
 420         addr->v6.sin6_family = AF_INET6;
 421         addr->v6.sin6_flowinfo = 0; /* FIXME */
 422         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 423
 424         /* Always called on head skb, so this is safe */
 425         sh = sctp_hdr(skb);
 426         if (is_saddr) {
 427                 *port  = sh->source;
 428                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 429         } else {
 430                 *port = sh->dest;
 431                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 432         }
 433 }
 434
 435 /* Initialize an sctp_addr from a socket. */
 436 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 437 {
 438         addr->v6.sin6_family = AF_INET6;
 439         addr->v6.sin6_port = 0;
 440         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 441 }
 442
 443 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 444 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 445 {
 446         if (addr->sa.sa_family == AF_INET) {
 447                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 448                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 449                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 450                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 451                         addr->v4.sin_addr.s_addr;
 452         } else {
 453                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 454         }
 455 }
 456
 457 /* Initialize sk->sk_daddr from sctp_addr. */
 458 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 459 {
 460         if (addr->sa.sa_family == AF_INET) {
 461                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 462                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 463                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 464                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 465         } else {
 466                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 467         }
 468 }
 469
 470 /* Initialize a sctp_addr from an address parameter. */
 471 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 472                                     union sctp_addr_param *param,
 473                                     __be16 port, int iif)
 474 {
 475         addr->v6.sin6_family = AF_INET6;
 476         addr->v6.sin6_port = port;
 477         addr->v6.sin6_flowinfo = 0; /* BUG */
 478         addr->v6.sin6_addr = param->v6.addr;
 479         addr->v6.sin6_scope_id = iif;
 480 }
 481
 482 /* Initialize an address parameter from a sctp_addr and return the length
 483  * of the address parameter.
 484  */
 485 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 486                                  union sctp_addr_param *param)
 487 {
 488         int length = sizeof(sctp_ipv6addr_param_t);
 489
 490         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 491         param->v6.param_hdr.length = htons(length);
 492         param->v6.addr = addr->v6.sin6_addr;
 493
 494         return length;
 495 }
 496
 497 /* Initialize a sctp_addr from struct in6_addr. */
 498 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 499                               __be16 port)
 500 {
 501         addr->sa.sa_family = AF_INET6;
 502         addr->v6.sin6_port = port;
 503         addr->v6.sin6_addr = *saddr;
 504 }
 505
 506 /* Compare addresses exactly.
 507  * v4-mapped-v6 is also in consideration.
 508  */
 509 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 510                             const union sctp_addr *addr2)
 511 {
 512         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 513                 if (addr1->sa.sa_family == AF_INET &&
 514                     addr2->sa.sa_family == AF_INET6 &&
 515                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 516                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 517                             addr2->v6.sin6_addr.s6_addr32[3] ==
 518                             addr1->v4.sin_addr.s_addr)
 519                                 return 1;
 520                 }
 521                 if (addr2->sa.sa_family == AF_INET &&
 522                     addr1->sa.sa_family == AF_INET6 &&
 523                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 524                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 525                             addr1->v6.sin6_addr.s6_addr32[3] ==
 526                             addr2->v4.sin_addr.s_addr)
 527                                 return 1;
 528                 }
 529                 return 0;
 530         }
 531         if (addr1->v6.sin6_port != addr2->v6.sin6_port)
 532                 return 0;
 533         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 534                 return 0;
 535         /* If this is a linklocal address, compare the scope_id. */
 536         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 537                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 538                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 539                         return 0;
 540                 }
 541         }
 542
 543         return 1;
 544 }
 545
 546 /* Initialize addr struct to INADDR_ANY. */
 547 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 548 {
 549         memset(addr, 0x00, sizeof(union sctp_addr));
 550         addr->v6.sin6_family = AF_INET6;
 551         addr->v6.sin6_port = port;
 552 }
 553
 554 /* Is this a wildcard address? */
 555 static int sctp_v6_is_any(const union sctp_addr *addr)
 556 {
 557         return ipv6_addr_any(&addr->v6.sin6_addr);
 558 }
 559
 560 /* Should this be available for binding?   */
 561 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 562 {
 563         int type;
 564         struct net *net = sock_net(&sp->inet.sk);
 565         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 566
 567         type = ipv6_addr_type(in6);
 568         if (IPV6_ADDR_ANY == type)
 569                 return 1;
 570         if (type == IPV6_ADDR_MAPPED) {
 571                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 572                         return 0;
 573                 sctp_v6_map_v4(addr);
 574                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 575         }
 576         if (!(type & IPV6_ADDR_UNICAST))
 577                 return 0;
 578
 579         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 580                 ipv6_chk_addr(net, in6, NULL, 0);
 581 }
 582
 583 /* This function checks if the address is a valid address to be used for
 584  * SCTP.
 585  *
 586  * Output:
 587  * Return 0 - If the address is a non-unicast or an illegal address.
 588  * Return 1 - If the address is a unicast.
 589  */
 590 static int sctp_v6_addr_valid(union sctp_addr *addr,
 591                               struct sctp_sock *sp,
 592                               const struct sk_buff *skb)
 593 {
 594         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 595
 596         /* Support v4-mapped-v6 address. */
 597         if (ret == IPV6_ADDR_MAPPED) {
 598                 /* Note: This routine is used in input, so v4-mapped-v6
 599                  * are disallowed here when there is no sctp_sock.
 600                  */
 601                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 602                         return 0;
 603                 sctp_v6_map_v4(addr);
 604                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 605         }
 606
 607         /* Is this a non-unicast address */
 608         if (!(ret & IPV6_ADDR_UNICAST))
 609                 return 0;
 610
 611         return 1;
 612 }
 613
 614 /* What is the scope of 'addr'?  */
 615 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 616 {
 617         int v6scope;
 618         sctp_scope_t retval;
 619
 620         /* The IPv6 scope is really a set of bit fields.
 621          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 622          */
 623
 624         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 625         switch (v6scope) {
 626         case IFA_HOST:
 627                 retval = SCTP_SCOPE_LOOPBACK;
 628                 break;
 629         case IFA_LINK:
 630                 retval = SCTP_SCOPE_LINK;
 631                 break;
 632         case IFA_SITE:
 633                 retval = SCTP_SCOPE_PRIVATE;
 634                 break;
 635         default:
 636                 retval = SCTP_SCOPE_GLOBAL;
 637                 break;
 638         }
 639
 640         return retval;
 641 }
 642
 643 /* Create and initialize a new sk for the socket to be returned by accept(). */
 644 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 645                                              struct sctp_association *asoc)
 646 {
 647         struct sock *newsk;
 648         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 649         struct sctp6_sock *newsctp6sk;
 650         struct ipv6_txoptions *opt;
 651
 652         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0);
 653         if (!newsk)
 654                 goto out;
 655
 656         sock_init_data(NULL, newsk);
 657
 658         sctp_copy_sock(newsk, sk, asoc);
 659         sock_reset_flag(sk, SOCK_ZAPPED);
 660
 661         newsctp6sk = (struct sctp6_sock *)newsk;
 662         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 663
 664         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 665
 666         newnp = inet6_sk(newsk);
 667
 668         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 669
 670         rcu_read_lock();
 671         opt = rcu_dereference(np->opt);
 672         if (opt)
 673                 opt = ipv6_dup_options(newsk, opt);
 674         RCU_INIT_POINTER(newnp->opt, opt);
 675         rcu_read_unlock();
 676
 677         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 678          * and getpeername().
 679          */
 680         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 681
 682         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 683
 684         sk_refcnt_debug_inc(newsk);
 685
 686         if (newsk->sk_prot->init(newsk)) {
 687                 sk_common_release(newsk);
 688                 newsk = NULL;
 689         }
 690
 691 out:
 692         return newsk;
 693 }
 694
 695 /* Format a sockaddr for return to user space. This makes sure the return is
 696  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 697  */
 698 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 699 {
 700         if (sp->v4mapped) {
 701                 if (addr->sa.sa_family == AF_INET)
 702                         sctp_v4_map_v6(addr);
 703         } else {
 704                 if (addr->sa.sa_family == AF_INET6 &&
 705                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 706                         sctp_v6_map_v4(addr);
 707         }
 708
 709         if (addr->sa.sa_family == AF_INET)
 710                 return sizeof(struct sockaddr_in);
 711         return sizeof(struct sockaddr_in6);
 712 }
 713
 714 /* Where did this skb come from?  */
 715 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 716 {
 717         return IP6CB(skb)->iif;
 718 }
 719
 720 /* Was this packet marked by Explicit Congestion Notification? */
 721 static int sctp_v6_is_ce(const struct sk_buff *skb)
 722 {
 723         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 724 }
 725
 726 /* Dump the v6 addr to the seq file. */
 727 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 728 {
 729         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 730 }
 731
 732 static void sctp_v6_ecn_capable(struct sock *sk)
 733 {
 734         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 735 }
 736
 737 /* Initialize a PF_INET msgname from a ulpevent. */
 738 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 739                                      char *msgname, int *addrlen)
 740 {
 741         union sctp_addr *addr;
 742         struct sctp_association *asoc;
 743         union sctp_addr *paddr;
 744
 745         if (!msgname)
 746                 return;
 747
 748         addr = (union sctp_addr *)msgname;
 749         asoc = event->asoc;
 750         paddr = &asoc->peer.primary_addr;
 751
 752         if (paddr->sa.sa_family == AF_INET) {
 753                 addr->v4.sin_family = AF_INET;
 754                 addr->v4.sin_port = htons(asoc->peer.port);
 755                 addr->v4.sin_addr = paddr->v4.sin_addr;
 756         } else {
 757                 addr->v6.sin6_family = AF_INET6;
 758                 addr->v6.sin6_flowinfo = 0;
 759                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 760                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 761                 else
 762                         addr->v6.sin6_scope_id = 0;
 763                 addr->v6.sin6_port = htons(asoc->peer.port);
 764                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 765         }
 766
 767         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 768 }
 769
 770 /* Initialize a msg_name from an inbound skb. */
 771 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 772                                    int *addr_len)
 773 {
 774         union sctp_addr *addr;
 775         struct sctphdr *sh;
 776
 777         if (!msgname)
 778                 return;
 779
 780         addr = (union sctp_addr *)msgname;
 781         sh = sctp_hdr(skb);
 782
 783         if (ip_hdr(skb)->version == 4) {
 784                 addr->v4.sin_family = AF_INET;
 785                 addr->v4.sin_port = sh->source;
 786                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 787         } else {
 788                 addr->v6.sin6_family = AF_INET6;
 789                 addr->v6.sin6_flowinfo = 0;
 790                 addr->v6.sin6_port = sh->source;
 791                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 792                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 793                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 794                 }
 795         }
 796
 797         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 798 }
 799
 800 /* Do we support this AF? */
 801 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 802 {
 803         switch (family) {
 804         case AF_INET6:
 805                 return 1;
 806         /* v4-mapped-v6 addresses */
 807         case AF_INET:
 808                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 809                         return 1;
 810         default:
 811                 return 0;
 812         }
 813 }
 814
 815 /* Address matching with wildcards allowed.  This extra level
 816  * of indirection lets us choose whether a PF_INET6 should
 817  * disallow any v4 addresses if we so choose.
 818  */
 819 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 820                                const union sctp_addr *addr2,
 821                                struct sctp_sock *opt)
 822 {
 823         struct sctp_af *af1, *af2;
 824         struct sock *sk = sctp_opt2sk(opt);
 825
 826         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 827         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 828
 829         if (!af1 || !af2)
 830                 return 0;
 831
 832         /* If the socket is IPv6 only, v4 addrs will not match */
 833         if (__ipv6_only_sock(sk) && af1 != af2)
 834                 return 0;
 835
 836         /* Today, wildcard AF_INET/AF_INET6. */
 837         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 838                 return 1;
 839
 840         if (addr1->sa.sa_family != addr2->sa.sa_family)
 841                 return 0;
 842
 843         return af1->cmp_addr(addr1, addr2);
 844 }
 845
 846 /* Verify that the provided sockaddr looks bindable.   Common verification,
 847  * has already been taken care of.
 848  */
 849 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 850 {
 851         struct sctp_af *af;
 852
 853         /* ASSERT: address family has already been verified. */
 854         if (addr->sa.sa_family != AF_INET6)
 855                 af = sctp_get_af_specific(addr->sa.sa_family);
 856         else {
 857                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 858                 struct net_device *dev;
 859
 860                 if (type & IPV6_ADDR_LINKLOCAL) {
 861                         struct net *net;
 862                         if (!addr->v6.sin6_scope_id)
 863                                 return 0;
 864                         net = sock_net(&opt->inet.sk);
 865                         rcu_read_lock();
 866                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 867                         if (!dev ||
 868                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 869                                 rcu_read_unlock();
 870                                 return 0;
 871                         }
 872                         rcu_read_unlock();
 873                 }
 874
 875                 af = opt->pf->af;
 876         }
 877         return af->available(addr, opt);
 878 }
 879
 880 /* Verify that the provided sockaddr looks sendable.   Common verification,
 881  * has already been taken care of.
 882  */
 883 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 884 {
 885         struct sctp_af *af = NULL;
 886
 887         /* ASSERT: address family has already been verified. */
 888         if (addr->sa.sa_family != AF_INET6)
 889                 af = sctp_get_af_specific(addr->sa.sa_family);
 890         else {
 891                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 892                 struct net_device *dev;
 893
 894                 if (type & IPV6_ADDR_LINKLOCAL) {
 895                         if (!addr->v6.sin6_scope_id)
 896                                 return 0;
 897                         rcu_read_lock();
 898                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 899                                                    addr->v6.sin6_scope_id);
 900                         rcu_read_unlock();
 901                         if (!dev)
 902                                 return 0;
 903                 }
 904                 af = opt->pf->af;
 905         }
 906
 907         return af != NULL;
 908 }
 909
 910 /* Fill in Supported Address Type information for INIT and INIT-ACK
 911  * chunks.   Note: In the future, we may want to look at sock options
 912  * to determine whether a PF_INET6 socket really wants to have IPV4
 913  * addresses.
 914  * Returns number of addresses supported.
 915  */
 916 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 917                                       __be16 *types)
 918 {
 919         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 920         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 921                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 922                 return 2;
 923         }
 924         return 1;
 925 }
 926
 927 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 928 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 929                         int *uaddr_len, int peer)
 930 {
 931         int rc;
 932
 933         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 934
 935         if (rc != 0)
 936                 return rc;
 937
 938         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 939                                           (union sctp_addr *)uaddr);
 940
 941         return rc;
 942 }
 943
 944 static const struct proto_ops inet6_seqpacket_ops = {
 945         .family            = PF_INET6,
 946         .owner             = THIS_MODULE,
 947         .release           = inet6_release,
 948         .bind              = inet6_bind,
 949         .connect           = inet_dgram_connect,
 950         .socketpair        = sock_no_socketpair,
 951         .accept            = inet_accept,
 952         .getname           = sctp_getname,
 953         .poll              = sctp_poll,
 954         .ioctl             = inet6_ioctl,
 955         .listen            = sctp_inet_listen,
 956         .shutdown          = inet_shutdown,
 957         .setsockopt        = sock_common_setsockopt,
 958         .getsockopt        = sock_common_getsockopt,
 959         .sendmsg           = inet_sendmsg,
 960         .recvmsg           = inet_recvmsg,
 961         .mmap              = sock_no_mmap,
 962 #ifdef CONFIG_COMPAT
 963         .compat_setsockopt = compat_sock_common_setsockopt,
 964         .compat_getsockopt = compat_sock_common_getsockopt,
 965 #endif
 966 };
 967
 968 static struct inet_protosw sctpv6_seqpacket_protosw = {
 969         .type          = SOCK_SEQPACKET,
 970         .protocol      = IPPROTO_SCTP,
 971         .prot          = &sctpv6_prot,
 972         .ops           = &inet6_seqpacket_ops,
 973         .flags         = SCTP_PROTOSW_FLAG
 974 };
 975 static struct inet_protosw sctpv6_stream_protosw = {
 976         .type          = SOCK_STREAM,
 977         .protocol      = IPPROTO_SCTP,
 978         .prot          = &sctpv6_prot,
 979         .ops           = &inet6_seqpacket_ops,
 980         .flags         = SCTP_PROTOSW_FLAG,
 981 };
 982
 983 static int sctp6_rcv(struct sk_buff *skb)
 984 {
 985         return sctp_rcv(skb) ? -1 : 0;
 986 }
 987
 988 static const struct inet6_protocol sctpv6_protocol = {
 989         .handler      = sctp6_rcv,
 990         .err_handler  = sctp_v6_err,
 991         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 992 };
 993
 994 static struct sctp_af sctp_af_inet6 = {
 995         .sa_family         = AF_INET6,
 996         .sctp_xmit         = sctp_v6_xmit,
 997         .setsockopt        = ipv6_setsockopt,
 998         .getsockopt        = ipv6_getsockopt,
 999         .get_dst           = sctp_v6_get_dst,
1000         .get_saddr         = sctp_v6_get_saddr,
1001         .copy_addrlist     = sctp_v6_copy_addrlist,
1002         .from_skb          = sctp_v6_from_skb,
1003         .from_sk           = sctp_v6_from_sk,
1004         .from_addr_param   = sctp_v6_from_addr_param,
1005         .to_addr_param     = sctp_v6_to_addr_param,
1006         .cmp_addr          = sctp_v6_cmp_addr,
1007         .scope             = sctp_v6_scope,
1008         .addr_valid        = sctp_v6_addr_valid,
1009         .inaddr_any        = sctp_v6_inaddr_any,
1010         .is_any            = sctp_v6_is_any,
1011         .available         = sctp_v6_available,
1012         .skb_iif           = sctp_v6_skb_iif,
1013         .is_ce             = sctp_v6_is_ce,
1014         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1015         .ecn_capable       = sctp_v6_ecn_capable,
1016         .net_header_len    = sizeof(struct ipv6hdr),
1017         .sockaddr_len      = sizeof(struct sockaddr_in6),
1018 #ifdef CONFIG_COMPAT
1019         .compat_setsockopt = compat_ipv6_setsockopt,
1020         .compat_getsockopt = compat_ipv6_getsockopt,
1021 #endif
1022 };
1023
1024 static struct sctp_pf sctp_pf_inet6 = {
1025         .event_msgname = sctp_inet6_event_msgname,
1026         .skb_msgname   = sctp_inet6_skb_msgname,
1027         .af_supported  = sctp_inet6_af_supported,
1028         .cmp_addr      = sctp_inet6_cmp_addr,
1029         .bind_verify   = sctp_inet6_bind_verify,
1030         .send_verify   = sctp_inet6_send_verify,
1031         .supported_addrs = sctp_inet6_supported_addrs,
1032         .create_accept_sk = sctp_v6_create_accept_sk,
1033         .addr_to_user  = sctp_v6_addr_to_user,
1034         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1035         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1036         .af            = &sctp_af_inet6,
1037 };
1038
1039 /* Initialize IPv6 support and register with socket layer.  */
1040 void sctp_v6_pf_init(void)
1041 {
1042         /* Register the SCTP specific PF_INET6 functions. */
1043         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1044
1045         /* Register the SCTP specific AF_INET6 functions. */
1046         sctp_register_af(&sctp_af_inet6);
1047 }
1048
1049 void sctp_v6_pf_exit(void)
1050 {
1051         list_del(&sctp_af_inet6.list);
1052 }
1053
1054 /* Initialize IPv6 support and register with socket layer.  */
1055 int sctp_v6_protosw_init(void)
1056 {
1057         int rc;
1058
1059         rc = proto_register(&sctpv6_prot, 1);
1060         if (rc)
1061                 return rc;
1062
1063         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1064         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1065         inet6_register_protosw(&sctpv6_stream_protosw);
1066
1067         return 0;
1068 }
1069
1070 void sctp_v6_protosw_exit(void)
1071 {
1072         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1073         inet6_unregister_protosw(&sctpv6_stream_protosw);
1074         proto_unregister(&sctpv6_prot);
1075 }
1076
1077
1078 /* Register with inet6 layer. */
1079 int sctp_v6_add_protocol(void)
1080 {
1081         /* Register notifier for inet6 address additions/deletions. */
1082         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1083
1084         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1085                 return -EAGAIN;
1086
1087         return 0;
1088 }
1089
1090 /* Unregister with inet6 layer. */
1091 void sctp_v6_del_protocol(void)
1092 {
1093         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1094         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1095 }