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(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, transport);
 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, sk->sk_mark, rcu_dereference(np->opt),
 225                        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 flowi _fl;
 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 *daddr = &t->ipaddr;
 244         union sctp_addr dst_saddr;
 245         struct in6_addr *final_p, final;
 246         __u8 matchlen = 0;
 247         sctp_scope_t scope;
 248
 249         memset(&_fl, 0, sizeof(_fl));
 250         fl6->daddr = daddr->v6.sin6_addr;
 251         fl6->fl6_dport = daddr->v6.sin6_port;
 252         fl6->flowi6_proto = IPPROTO_SCTP;
 253         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 254                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 255
 256         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 257
 258         if (asoc)
 259                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 260
 261         if (saddr) {
 262                 fl6->saddr = saddr->v6.sin6_addr;
 263                 fl6->fl6_sport = saddr->v6.sin6_port;
 264
 265                 pr_debug("src=%pI6 - ", &fl6->saddr);
 266         }
 267
 268         rcu_read_lock();
 269         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 270         rcu_read_unlock();
 271
 272         dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 273         if (!asoc || saddr) {
 274                 t->dst = dst;
 275                 memcpy(fl, &_fl, sizeof(_fl));
 276                 goto out;
 277         }
 278
 279         bp = &asoc->base.bind_addr;
 280         scope = sctp_scope(daddr);
 281         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 282          * to see if we can use it.
 283          */
 284         if (!IS_ERR(dst)) {
 285                 /* Walk through the bind address list and look for a bind
 286                  * address that matches the source address of the returned dst.
 287                  */
 288                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 289                 rcu_read_lock();
 290                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 291                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 292                             (laddr->state != SCTP_ADDR_SRC &&
 293                              !asoc->src_out_of_asoc_ok))
 294                                 continue;
 295
 296                         /* Do not compare against v4 addrs */
 297                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 298                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 299                                 rcu_read_unlock();
 300                                 t->dst = dst;
 301                                 memcpy(fl, &_fl, sizeof(_fl));
 302                                 goto out;
 303                         }
 304                 }
 305                 rcu_read_unlock();
 306                 /* None of the bound addresses match the source address of the
 307                  * dst. So release it.
 308                  */
 309                 dst_release(dst);
 310                 dst = NULL;
 311         }
 312
 313         /* Walk through the bind address list and try to get the
 314          * best source address for a given destination.
 315          */
 316         rcu_read_lock();
 317         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 318                 struct dst_entry *bdst;
 319                 __u8 bmatchlen;
 320
 321                 if (!laddr->valid ||
 322                     laddr->state != SCTP_ADDR_SRC ||
 323                     laddr->a.sa.sa_family != AF_INET6 ||
 324                     scope > sctp_scope(&laddr->a))
 325                         continue;
 326
 327                 fl6->saddr = laddr->a.v6.sin6_addr;
 328                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 329                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 330                 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 331
 332                 if (IS_ERR(bdst))
 333                         continue;
 334
 335                 if (ipv6_chk_addr(dev_net(bdst->dev),
 336                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 337                         if (!IS_ERR_OR_NULL(dst))
 338                                 dst_release(dst);
 339                         dst = bdst;
 340                         t->dst = dst;
 341                         memcpy(fl, &_fl, sizeof(_fl));
 342                         break;
 343                 }
 344
 345                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 346                 if (matchlen > bmatchlen) {
 347                         dst_release(bdst);
 348                         continue;
 349                 }
 350
 351                 if (!IS_ERR_OR_NULL(dst))
 352                         dst_release(dst);
 353                 dst = bdst;
 354                 matchlen = bmatchlen;
 355                 t->dst = dst;
 356                 memcpy(fl, &_fl, sizeof(_fl));
 357         }
 358         rcu_read_unlock();
 359
 360 out:
 361         if (!IS_ERR_OR_NULL(dst)) {
 362                 struct rt6_info *rt;
 363
 364                 rt = (struct rt6_info *)dst;
 365                 t->dst_cookie = rt6_get_cookie(rt);
 366                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 367                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 368                          &fl->u.ip6.saddr);
 369         } else {
 370                 t->dst = NULL;
 371                 pr_debug("no route\n");
 372         }
 373 }
 374
 375 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 376  * addresses.
 377  */
 378 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 379                                          union sctp_addr *s2)
 380 {
 381         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 382 }
 383
 384 /* Fills in the source address(saddr) based on the destination address(daddr)
 385  * and asoc's bind address list.
 386  */
 387 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 388                               struct sctp_transport *t,
 389                               struct flowi *fl)
 390 {
 391         struct flowi6 *fl6 = &fl->u.ip6;
 392         union sctp_addr *saddr = &t->saddr;
 393
 394         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 395
 396         if (t->dst) {
 397                 saddr->v6.sin6_family = AF_INET6;
 398                 saddr->v6.sin6_addr = fl6->saddr;
 399         }
 400 }
 401
 402 /* Make a copy of all potential local addresses. */
 403 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 404                                   struct net_device *dev)
 405 {
 406         struct inet6_dev *in6_dev;
 407         struct inet6_ifaddr *ifp;
 408         struct sctp_sockaddr_entry *addr;
 409
 410         rcu_read_lock();
 411         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 412                 rcu_read_unlock();
 413                 return;
 414         }
 415
 416         read_lock_bh(&in6_dev->lock);
 417         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 418                 /* Add the address to the local list.  */
 419                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 420                 if (addr) {
 421                         addr->a.v6.sin6_family = AF_INET6;
 422                         addr->a.v6.sin6_addr = ifp->addr;
 423                         addr->a.v6.sin6_scope_id = dev->ifindex;
 424                         addr->valid = 1;
 425                         INIT_LIST_HEAD(&addr->list);
 426                         list_add_tail(&addr->list, addrlist);
 427                 }
 428         }
 429
 430         read_unlock_bh(&in6_dev->lock);
 431         rcu_read_unlock();
 432 }
 433
 434 /* Initialize a sockaddr_storage from in incoming skb. */
 435 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 436                              int is_saddr)
 437 {
 438         __be16 *port;
 439         struct sctphdr *sh;
 440
 441         port = &addr->v6.sin6_port;
 442         addr->v6.sin6_family = AF_INET6;
 443         addr->v6.sin6_flowinfo = 0; /* FIXME */
 444         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 445
 446         /* Always called on head skb, so this is safe */
 447         sh = sctp_hdr(skb);
 448         if (is_saddr) {
 449                 *port  = sh->source;
 450                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 451         } else {
 452                 *port = sh->dest;
 453                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 454         }
 455 }
 456
 457 /* Initialize an sctp_addr from a socket. */
 458 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 459 {
 460         addr->v6.sin6_family = AF_INET6;
 461         addr->v6.sin6_port = 0;
 462         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 463 }
 464
 465 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 466 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 467 {
 468         if (addr->sa.sa_family == AF_INET) {
 469                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 470                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 471                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 472                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 473                         addr->v4.sin_addr.s_addr;
 474         } else {
 475                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 476         }
 477 }
 478
 479 /* Initialize sk->sk_daddr from sctp_addr. */
 480 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 481 {
 482         if (addr->sa.sa_family == AF_INET) {
 483                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 484                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 485                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 486                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 487         } else {
 488                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 489         }
 490 }
 491
 492 /* Initialize a sctp_addr from an address parameter. */
 493 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 494                                     union sctp_addr_param *param,
 495                                     __be16 port, int iif)
 496 {
 497         addr->v6.sin6_family = AF_INET6;
 498         addr->v6.sin6_port = port;
 499         addr->v6.sin6_flowinfo = 0; /* BUG */
 500         addr->v6.sin6_addr = param->v6.addr;
 501         addr->v6.sin6_scope_id = iif;
 502 }
 503
 504 /* Initialize an address parameter from a sctp_addr and return the length
 505  * of the address parameter.
 506  */
 507 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 508                                  union sctp_addr_param *param)
 509 {
 510         int length = sizeof(sctp_ipv6addr_param_t);
 511
 512         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 513         param->v6.param_hdr.length = htons(length);
 514         param->v6.addr = addr->v6.sin6_addr;
 515
 516         return length;
 517 }
 518
 519 /* Initialize a sctp_addr from struct in6_addr. */
 520 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 521                               __be16 port)
 522 {
 523         addr->sa.sa_family = AF_INET6;
 524         addr->v6.sin6_port = port;
 525         addr->v6.sin6_flowinfo = 0;
 526         addr->v6.sin6_addr = *saddr;
 527         addr->v6.sin6_scope_id = 0;
 528 }
 529
 530 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 531                               const union sctp_addr *addr2)
 532 {
 533         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 534                 if (addr1->sa.sa_family == AF_INET &&
 535                     addr2->sa.sa_family == AF_INET6 &&
 536                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 537                     addr2->v6.sin6_addr.s6_addr32[3] ==
 538                     addr1->v4.sin_addr.s_addr)
 539                         return 1;
 540
 541                 if (addr2->sa.sa_family == AF_INET &&
 542                     addr1->sa.sa_family == AF_INET6 &&
 543                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 544                     addr1->v6.sin6_addr.s6_addr32[3] ==
 545                     addr2->v4.sin_addr.s_addr)
 546                         return 1;
 547
 548                 return 0;
 549         }
 550
 551         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 552                 return 0;
 553
 554         /* If this is a linklocal address, compare the scope_id. */
 555         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 556             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 557             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 558                 return 0;
 559
 560         return 1;
 561 }
 562
 563 /* Compare addresses exactly.
 564  * v4-mapped-v6 is also in consideration.
 565  */
 566 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 567                             const union sctp_addr *addr2)
 568 {
 569         return __sctp_v6_cmp_addr(addr1, addr2) &&
 570                addr1->v6.sin6_port == addr2->v6.sin6_port;
 571 }
 572
 573 /* Initialize addr struct to INADDR_ANY. */
 574 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 575 {
 576         memset(addr, 0x00, sizeof(union sctp_addr));
 577         addr->v6.sin6_family = AF_INET6;
 578         addr->v6.sin6_port = port;
 579 }
 580
 581 /* Is this a wildcard address? */
 582 static int sctp_v6_is_any(const union sctp_addr *addr)
 583 {
 584         return ipv6_addr_any(&addr->v6.sin6_addr);
 585 }
 586
 587 /* Should this be available for binding?   */
 588 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 589 {
 590         int type;
 591         struct net *net = sock_net(&sp->inet.sk);
 592         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 593
 594         type = ipv6_addr_type(in6);
 595         if (IPV6_ADDR_ANY == type)
 596                 return 1;
 597         if (type == IPV6_ADDR_MAPPED) {
 598                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 599                         return 0;
 600                 sctp_v6_map_v4(addr);
 601                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 602         }
 603         if (!(type & IPV6_ADDR_UNICAST))
 604                 return 0;
 605
 606         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 607                 ipv6_chk_addr(net, in6, NULL, 0);
 608 }
 609
 610 /* This function checks if the address is a valid address to be used for
 611  * SCTP.
 612  *
 613  * Output:
 614  * Return 0 - If the address is a non-unicast or an illegal address.
 615  * Return 1 - If the address is a unicast.
 616  */
 617 static int sctp_v6_addr_valid(union sctp_addr *addr,
 618                               struct sctp_sock *sp,
 619                               const struct sk_buff *skb)
 620 {
 621         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 622
 623         /* Support v4-mapped-v6 address. */
 624         if (ret == IPV6_ADDR_MAPPED) {
 625                 /* Note: This routine is used in input, so v4-mapped-v6
 626                  * are disallowed here when there is no sctp_sock.
 627                  */
 628                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 629                         return 0;
 630                 sctp_v6_map_v4(addr);
 631                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 632         }
 633
 634         /* Is this a non-unicast address */
 635         if (!(ret & IPV6_ADDR_UNICAST))
 636                 return 0;
 637
 638         return 1;
 639 }
 640
 641 /* What is the scope of 'addr'?  */
 642 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 643 {
 644         int v6scope;
 645         sctp_scope_t retval;
 646
 647         /* The IPv6 scope is really a set of bit fields.
 648          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 649          */
 650
 651         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 652         switch (v6scope) {
 653         case IFA_HOST:
 654                 retval = SCTP_SCOPE_LOOPBACK;
 655                 break;
 656         case IFA_LINK:
 657                 retval = SCTP_SCOPE_LINK;
 658                 break;
 659         case IFA_SITE:
 660                 retval = SCTP_SCOPE_PRIVATE;
 661                 break;
 662         default:
 663                 retval = SCTP_SCOPE_GLOBAL;
 664                 break;
 665         }
 666
 667         return retval;
 668 }
 669
 670 /* Create and initialize a new sk for the socket to be returned by accept(). */
 671 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 672                                              struct sctp_association *asoc)
 673 {
 674         struct sock *newsk;
 675         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 676         struct sctp6_sock *newsctp6sk;
 677         struct ipv6_txoptions *opt;
 678
 679         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0);
 680         if (!newsk)
 681                 goto out;
 682
 683         sock_init_data(NULL, newsk);
 684
 685         sctp_copy_sock(newsk, sk, asoc);
 686         sock_reset_flag(sk, SOCK_ZAPPED);
 687
 688         newsctp6sk = (struct sctp6_sock *)newsk;
 689         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 690
 691         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 692
 693         newnp = inet6_sk(newsk);
 694
 695         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 696         newnp->ipv6_mc_list = NULL;
 697         newnp->ipv6_ac_list = NULL;
 698         newnp->ipv6_fl_list = NULL;
 699
 700         rcu_read_lock();
 701         opt = rcu_dereference(np->opt);
 702         if (opt)
 703                 opt = ipv6_dup_options(newsk, opt);
 704         RCU_INIT_POINTER(newnp->opt, opt);
 705         rcu_read_unlock();
 706
 707         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 708          * and getpeername().
 709          */
 710         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 711
 712         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 713
 714         sk_refcnt_debug_inc(newsk);
 715
 716         if (newsk->sk_prot->init(newsk)) {
 717                 sk_common_release(newsk);
 718                 newsk = NULL;
 719         }
 720
 721 out:
 722         return newsk;
 723 }
 724
 725 /* Format a sockaddr for return to user space. This makes sure the return is
 726  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 727  */
 728 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 729 {
 730         if (sp->v4mapped) {
 731                 if (addr->sa.sa_family == AF_INET)
 732                         sctp_v4_map_v6(addr);
 733         } else {
 734                 if (addr->sa.sa_family == AF_INET6 &&
 735                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 736                         sctp_v6_map_v4(addr);
 737         }
 738
 739         if (addr->sa.sa_family == AF_INET) {
 740                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 741                 return sizeof(struct sockaddr_in);
 742         }
 743         return sizeof(struct sockaddr_in6);
 744 }
 745
 746 /* Where did this skb come from?  */
 747 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 748 {
 749         return IP6CB(skb)->iif;
 750 }
 751
 752 /* Was this packet marked by Explicit Congestion Notification? */
 753 static int sctp_v6_is_ce(const struct sk_buff *skb)
 754 {
 755         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 756 }
 757
 758 /* Dump the v6 addr to the seq file. */
 759 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 760 {
 761         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 762 }
 763
 764 static void sctp_v6_ecn_capable(struct sock *sk)
 765 {
 766         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 767 }
 768
 769 /* Initialize a PF_INET msgname from a ulpevent. */
 770 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 771                                      char *msgname, int *addrlen)
 772 {
 773         union sctp_addr *addr;
 774         struct sctp_association *asoc;
 775         union sctp_addr *paddr;
 776
 777         if (!msgname)
 778                 return;
 779
 780         addr = (union sctp_addr *)msgname;
 781         asoc = event->asoc;
 782         paddr = &asoc->peer.primary_addr;
 783
 784         if (paddr->sa.sa_family == AF_INET) {
 785                 addr->v4.sin_family = AF_INET;
 786                 addr->v4.sin_port = htons(asoc->peer.port);
 787                 addr->v4.sin_addr = paddr->v4.sin_addr;
 788         } else {
 789                 addr->v6.sin6_family = AF_INET6;
 790                 addr->v6.sin6_flowinfo = 0;
 791                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 792                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 793                 else
 794                         addr->v6.sin6_scope_id = 0;
 795                 addr->v6.sin6_port = htons(asoc->peer.port);
 796                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 797         }
 798
 799         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 800 }
 801
 802 /* Initialize a msg_name from an inbound skb. */
 803 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 804                                    int *addr_len)
 805 {
 806         union sctp_addr *addr;
 807         struct sctphdr *sh;
 808
 809         if (!msgname)
 810                 return;
 811
 812         addr = (union sctp_addr *)msgname;
 813         sh = sctp_hdr(skb);
 814
 815         if (ip_hdr(skb)->version == 4) {
 816                 addr->v4.sin_family = AF_INET;
 817                 addr->v4.sin_port = sh->source;
 818                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 819         } else {
 820                 addr->v6.sin6_family = AF_INET6;
 821                 addr->v6.sin6_flowinfo = 0;
 822                 addr->v6.sin6_port = sh->source;
 823                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 824                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 825                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 826                 else
 827                         addr->v6.sin6_scope_id = 0;
 828         }
 829
 830         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 831 }
 832
 833 /* Do we support this AF? */
 834 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 835 {
 836         switch (family) {
 837         case AF_INET6:
 838                 return 1;
 839         /* v4-mapped-v6 addresses */
 840         case AF_INET:
 841                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 842                         return 1;
 843         default:
 844                 return 0;
 845         }
 846 }
 847
 848 /* Address matching with wildcards allowed.  This extra level
 849  * of indirection lets us choose whether a PF_INET6 should
 850  * disallow any v4 addresses if we so choose.
 851  */
 852 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 853                                const union sctp_addr *addr2,
 854                                struct sctp_sock *opt)
 855 {
 856         struct sock *sk = sctp_opt2sk(opt);
 857         struct sctp_af *af1, *af2;
 858
 859         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 860         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 861
 862         if (!af1 || !af2)
 863                 return 0;
 864
 865         /* If the socket is IPv6 only, v4 addrs will not match */
 866         if (__ipv6_only_sock(sk) && af1 != af2)
 867                 return 0;
 868
 869         /* Today, wildcard AF_INET/AF_INET6. */
 870         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 871                 return 1;
 872
 873         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 874                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 875
 876         return __sctp_v6_cmp_addr(addr1, addr2);
 877 }
 878
 879 /* Verify that the provided sockaddr looks bindable.   Common verification,
 880  * has already been taken care of.
 881  */
 882 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 883 {
 884         struct sctp_af *af;
 885
 886         /* ASSERT: address family has already been verified. */
 887         if (addr->sa.sa_family != AF_INET6)
 888                 af = sctp_get_af_specific(addr->sa.sa_family);
 889         else {
 890                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 891                 struct net_device *dev;
 892
 893                 if (type & IPV6_ADDR_LINKLOCAL) {
 894                         struct net *net;
 895                         if (!addr->v6.sin6_scope_id)
 896                                 return 0;
 897                         net = sock_net(&opt->inet.sk);
 898                         rcu_read_lock();
 899                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 900                         if (!dev || !(opt->inet.freebind ||
 901                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 902                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 903                                                     dev, 0))) {
 904                                 rcu_read_unlock();
 905                                 return 0;
 906                         }
 907                         rcu_read_unlock();
 908                 }
 909
 910                 af = opt->pf->af;
 911         }
 912         return af->available(addr, opt);
 913 }
 914
 915 /* Verify that the provided sockaddr looks sendable.   Common verification,
 916  * has already been taken care of.
 917  */
 918 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 919 {
 920         struct sctp_af *af = NULL;
 921
 922         /* ASSERT: address family has already been verified. */
 923         if (addr->sa.sa_family != AF_INET6)
 924                 af = sctp_get_af_specific(addr->sa.sa_family);
 925         else {
 926                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 927                 struct net_device *dev;
 928
 929                 if (type & IPV6_ADDR_LINKLOCAL) {
 930                         if (!addr->v6.sin6_scope_id)
 931                                 return 0;
 932                         rcu_read_lock();
 933                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 934                                                    addr->v6.sin6_scope_id);
 935                         rcu_read_unlock();
 936                         if (!dev)
 937                                 return 0;
 938                 }
 939                 af = opt->pf->af;
 940         }
 941
 942         return af != NULL;
 943 }
 944
 945 /* Fill in Supported Address Type information for INIT and INIT-ACK
 946  * chunks.   Note: In the future, we may want to look at sock options
 947  * to determine whether a PF_INET6 socket really wants to have IPV4
 948  * addresses.
 949  * Returns number of addresses supported.
 950  */
 951 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 952                                       __be16 *types)
 953 {
 954         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 955         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 956                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 957                 return 2;
 958         }
 959         return 1;
 960 }
 961
 962 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 963 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 964                         int *uaddr_len, int peer)
 965 {
 966         int rc;
 967
 968         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 969
 970         if (rc != 0)
 971                 return rc;
 972
 973         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 974                                           (union sctp_addr *)uaddr);
 975
 976         return rc;
 977 }
 978
 979 static const struct proto_ops inet6_seqpacket_ops = {
 980         .family            = PF_INET6,
 981         .owner             = THIS_MODULE,
 982         .release           = inet6_release,
 983         .bind              = inet6_bind,
 984         .connect           = sctp_inet_connect,
 985         .socketpair        = sock_no_socketpair,
 986         .accept            = inet_accept,
 987         .getname           = sctp_getname,
 988         .poll              = sctp_poll,
 989         .ioctl             = inet6_ioctl,
 990         .listen            = sctp_inet_listen,
 991         .shutdown          = inet_shutdown,
 992         .setsockopt        = sock_common_setsockopt,
 993         .getsockopt        = sock_common_getsockopt,
 994         .sendmsg           = inet_sendmsg,
 995         .recvmsg           = inet_recvmsg,
 996         .mmap              = sock_no_mmap,
 997 #ifdef CONFIG_COMPAT
 998         .compat_setsockopt = compat_sock_common_setsockopt,
 999         .compat_getsockopt = compat_sock_common_getsockopt,
1000 #endif
1001 };
1002
1003 static struct inet_protosw sctpv6_seqpacket_protosw = {
1004         .type          = SOCK_SEQPACKET,
1005         .protocol      = IPPROTO_SCTP,
1006         .prot          = &sctpv6_prot,
1007         .ops           = &inet6_seqpacket_ops,
1008         .flags         = SCTP_PROTOSW_FLAG
1009 };
1010 static struct inet_protosw sctpv6_stream_protosw = {
1011         .type          = SOCK_STREAM,
1012         .protocol      = IPPROTO_SCTP,
1013         .prot          = &sctpv6_prot,
1014         .ops           = &inet6_seqpacket_ops,
1015         .flags         = SCTP_PROTOSW_FLAG,
1016 };
1017
1018 static int sctp6_rcv(struct sk_buff *skb)
1019 {
1020         return sctp_rcv(skb) ? -1 : 0;
1021 }
1022
1023 static const struct inet6_protocol sctpv6_protocol = {
1024         .handler      = sctp6_rcv,
1025         .err_handler  = sctp_v6_err,
1026         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1027 };
1028
1029 static struct sctp_af sctp_af_inet6 = {
1030         .sa_family         = AF_INET6,
1031         .sctp_xmit         = sctp_v6_xmit,
1032         .setsockopt        = ipv6_setsockopt,
1033         .getsockopt        = ipv6_getsockopt,
1034         .get_dst           = sctp_v6_get_dst,
1035         .get_saddr         = sctp_v6_get_saddr,
1036         .copy_addrlist     = sctp_v6_copy_addrlist,
1037         .from_skb          = sctp_v6_from_skb,
1038         .from_sk           = sctp_v6_from_sk,
1039         .from_addr_param   = sctp_v6_from_addr_param,
1040         .to_addr_param     = sctp_v6_to_addr_param,
1041         .cmp_addr          = sctp_v6_cmp_addr,
1042         .scope             = sctp_v6_scope,
1043         .addr_valid        = sctp_v6_addr_valid,
1044         .inaddr_any        = sctp_v6_inaddr_any,
1045         .is_any            = sctp_v6_is_any,
1046         .available         = sctp_v6_available,
1047         .skb_iif           = sctp_v6_skb_iif,
1048         .is_ce             = sctp_v6_is_ce,
1049         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1050         .ecn_capable       = sctp_v6_ecn_capable,
1051         .net_header_len    = sizeof(struct ipv6hdr),
1052         .sockaddr_len      = sizeof(struct sockaddr_in6),
1053 #ifdef CONFIG_COMPAT
1054         .compat_setsockopt = compat_ipv6_setsockopt,
1055         .compat_getsockopt = compat_ipv6_getsockopt,
1056 #endif
1057 };
1058
1059 static struct sctp_pf sctp_pf_inet6 = {
1060         .event_msgname = sctp_inet6_event_msgname,
1061         .skb_msgname   = sctp_inet6_skb_msgname,
1062         .af_supported  = sctp_inet6_af_supported,
1063         .cmp_addr      = sctp_inet6_cmp_addr,
1064         .bind_verify   = sctp_inet6_bind_verify,
1065         .send_verify   = sctp_inet6_send_verify,
1066         .supported_addrs = sctp_inet6_supported_addrs,
1067         .create_accept_sk = sctp_v6_create_accept_sk,
1068         .addr_to_user  = sctp_v6_addr_to_user,
1069         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1070         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1071         .af            = &sctp_af_inet6,
1072 };
1073
1074 /* Initialize IPv6 support and register with socket layer.  */
1075 void sctp_v6_pf_init(void)
1076 {
1077         /* Register the SCTP specific PF_INET6 functions. */
1078         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1079
1080         /* Register the SCTP specific AF_INET6 functions. */
1081         sctp_register_af(&sctp_af_inet6);
1082 }
1083
1084 void sctp_v6_pf_exit(void)
1085 {
1086         list_del(&sctp_af_inet6.list);
1087 }
1088
1089 /* Initialize IPv6 support and register with socket layer.  */
1090 int sctp_v6_protosw_init(void)
1091 {
1092         int rc;
1093
1094         rc = proto_register(&sctpv6_prot, 1);
1095         if (rc)
1096                 return rc;
1097
1098         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1099         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1100         inet6_register_protosw(&sctpv6_stream_protosw);
1101
1102         return 0;
1103 }
1104
1105 void sctp_v6_protosw_exit(void)
1106 {
1107         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1108         inet6_unregister_protosw(&sctpv6_stream_protosw);
1109         proto_unregister(&sctpv6_prot);
1110 }
1111
1112
1113 /* Register with inet6 layer. */
1114 int sctp_v6_add_protocol(void)
1115 {
1116         /* Register notifier for inet6 address additions/deletions. */
1117         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1118
1119         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1120                 return -EAGAIN;
1121
1122         return 0;
1123 }
1124
1125 /* Unregister with inet6 layer. */
1126 void sctp_v6_del_protocol(void)
1127 {
1128         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1129         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1130 }