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 = 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         enum sctp_scope scope;
 247         __u8 matchlen = 0;
 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         else if (asoc)
 256                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 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(sock_net(sk), sk, fl6, final_p);
 275         if (!asoc || saddr) {
 276                 t->dst = dst;
 277                 memcpy(fl, &_fl, sizeof(_fl));
 278                 goto out;
 279         }
 280
 281         bp = &asoc->base.bind_addr;
 282         scope = sctp_scope(daddr);
 283         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 284          * to see if we can use it.
 285          */
 286         if (!IS_ERR(dst)) {
 287                 /* Walk through the bind address list and look for a bind
 288                  * address that matches the source address of the returned dst.
 289                  */
 290                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 291                 rcu_read_lock();
 292                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 293                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 294                             (laddr->state != SCTP_ADDR_SRC &&
 295                              !asoc->src_out_of_asoc_ok))
 296                                 continue;
 297
 298                         /* Do not compare against v4 addrs */
 299                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 300                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 301                                 rcu_read_unlock();
 302                                 t->dst = dst;
 303                                 memcpy(fl, &_fl, sizeof(_fl));
 304                                 goto out;
 305                         }
 306                 }
 307                 rcu_read_unlock();
 308                 /* None of the bound addresses match the source address of the
 309                  * dst. So release it.
 310                  */
 311                 dst_release(dst);
 312                 dst = NULL;
 313         }
 314
 315         /* Walk through the bind address list and try to get the
 316          * best source address for a given destination.
 317          */
 318         rcu_read_lock();
 319         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 320                 struct dst_entry *bdst;
 321                 __u8 bmatchlen;
 322
 323                 if (!laddr->valid ||
 324                     laddr->state != SCTP_ADDR_SRC ||
 325                     laddr->a.sa.sa_family != AF_INET6 ||
 326                     scope > sctp_scope(&laddr->a))
 327                         continue;
 328
 329                 fl6->saddr = laddr->a.v6.sin6_addr;
 330                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 331                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 332                 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 333
 334                 if (IS_ERR(bdst))
 335                         continue;
 336
 337                 if (ipv6_chk_addr(dev_net(bdst->dev),
 338                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 339                         if (!IS_ERR_OR_NULL(dst))
 340                                 dst_release(dst);
 341                         dst = bdst;
 342                         t->dst = dst;
 343                         memcpy(fl, &_fl, sizeof(_fl));
 344                         break;
 345                 }
 346
 347                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 348                 if (matchlen > bmatchlen) {
 349                         dst_release(bdst);
 350                         continue;
 351                 }
 352
 353                 if (!IS_ERR_OR_NULL(dst))
 354                         dst_release(dst);
 355                 dst = bdst;
 356                 matchlen = bmatchlen;
 357                 t->dst = dst;
 358                 memcpy(fl, &_fl, sizeof(_fl));
 359         }
 360         rcu_read_unlock();
 361
 362 out:
 363         if (!IS_ERR_OR_NULL(dst)) {
 364                 struct rt6_info *rt;
 365
 366                 rt = (struct rt6_info *)dst;
 367                 t->dst_cookie = rt6_get_cookie(rt);
 368                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 369                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 370                          &fl->u.ip6.saddr);
 371         } else {
 372                 t->dst = NULL;
 373                 pr_debug("no route\n");
 374         }
 375 }
 376
 377 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 378  * addresses.
 379  */
 380 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 381                                          union sctp_addr *s2)
 382 {
 383         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 384 }
 385
 386 /* Fills in the source address(saddr) based on the destination address(daddr)
 387  * and asoc's bind address list.
 388  */
 389 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 390                               struct sctp_transport *t,
 391                               struct flowi *fl)
 392 {
 393         struct flowi6 *fl6 = &fl->u.ip6;
 394         union sctp_addr *saddr = &t->saddr;
 395
 396         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 397
 398         if (t->dst) {
 399                 saddr->v6.sin6_family = AF_INET6;
 400                 saddr->v6.sin6_addr = fl6->saddr;
 401         }
 402 }
 403
 404 /* Make a copy of all potential local addresses. */
 405 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 406                                   struct net_device *dev)
 407 {
 408         struct inet6_dev *in6_dev;
 409         struct inet6_ifaddr *ifp;
 410         struct sctp_sockaddr_entry *addr;
 411
 412         rcu_read_lock();
 413         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 414                 rcu_read_unlock();
 415                 return;
 416         }
 417
 418         read_lock_bh(&in6_dev->lock);
 419         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 420                 /* Add the address to the local list.  */
 421                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 422                 if (addr) {
 423                         addr->a.v6.sin6_family = AF_INET6;
 424                         addr->a.v6.sin6_addr = ifp->addr;
 425                         addr->a.v6.sin6_scope_id = dev->ifindex;
 426                         addr->valid = 1;
 427                         INIT_LIST_HEAD(&addr->list);
 428                         list_add_tail(&addr->list, addrlist);
 429                 }
 430         }
 431
 432         read_unlock_bh(&in6_dev->lock);
 433         rcu_read_unlock();
 434 }
 435
 436 /* Initialize a sockaddr_storage from in incoming skb. */
 437 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 438                              int is_saddr)
 439 {
 440         /* Always called on head skb, so this is safe */
 441         struct sctphdr *sh = sctp_hdr(skb);
 442         struct sockaddr_in6 *sa = &addr->v6;
 443
 444         addr->v6.sin6_family = AF_INET6;
 445         addr->v6.sin6_flowinfo = 0; /* FIXME */
 446         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 447
 448         if (is_saddr) {
 449                 sa->sin6_port = sh->source;
 450                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 451         } else {
 452                 sa->sin6_port = sh->dest;
 453                 sa->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 bool sctp_v6_from_addr_param(union sctp_addr *addr,
 494                                     union sctp_addr_param *param,
 495                                     __be16 port, int iif)
 496 {
 497         if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
 498                 return false;
 499
 500         addr->v6.sin6_family = AF_INET6;
 501         addr->v6.sin6_port = port;
 502         addr->v6.sin6_flowinfo = 0; /* BUG */
 503         addr->v6.sin6_addr = param->v6.addr;
 504         addr->v6.sin6_scope_id = iif;
 505
 506         return true;
 507 }
 508
 509 /* Initialize an address parameter from a sctp_addr and return the length
 510  * of the address parameter.
 511  */
 512 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 513                                  union sctp_addr_param *param)
 514 {
 515         int length = sizeof(struct sctp_ipv6addr_param);
 516
 517         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 518         param->v6.param_hdr.length = htons(length);
 519         param->v6.addr = addr->v6.sin6_addr;
 520
 521         return length;
 522 }
 523
 524 /* Initialize a sctp_addr from struct in6_addr. */
 525 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 526                               __be16 port)
 527 {
 528         addr->sa.sa_family = AF_INET6;
 529         addr->v6.sin6_port = port;
 530         addr->v6.sin6_flowinfo = 0;
 531         addr->v6.sin6_addr = *saddr;
 532         addr->v6.sin6_scope_id = 0;
 533 }
 534
 535 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 536                               const union sctp_addr *addr2)
 537 {
 538         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 539                 if (addr1->sa.sa_family == AF_INET &&
 540                     addr2->sa.sa_family == AF_INET6 &&
 541                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 542                     addr2->v6.sin6_addr.s6_addr32[3] ==
 543                     addr1->v4.sin_addr.s_addr)
 544                         return 1;
 545
 546                 if (addr2->sa.sa_family == AF_INET &&
 547                     addr1->sa.sa_family == AF_INET6 &&
 548                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 549                     addr1->v6.sin6_addr.s6_addr32[3] ==
 550                     addr2->v4.sin_addr.s_addr)
 551                         return 1;
 552
 553                 return 0;
 554         }
 555
 556         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 557                 return 0;
 558
 559         /* If this is a linklocal address, compare the scope_id. */
 560         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 561             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 562             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 563                 return 0;
 564
 565         return 1;
 566 }
 567
 568 /* Compare addresses exactly.
 569  * v4-mapped-v6 is also in consideration.
 570  */
 571 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 572                             const union sctp_addr *addr2)
 573 {
 574         return __sctp_v6_cmp_addr(addr1, addr2) &&
 575                addr1->v6.sin6_port == addr2->v6.sin6_port;
 576 }
 577
 578 /* Initialize addr struct to INADDR_ANY. */
 579 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 580 {
 581         memset(addr, 0x00, sizeof(union sctp_addr));
 582         addr->v6.sin6_family = AF_INET6;
 583         addr->v6.sin6_port = port;
 584 }
 585
 586 /* Is this a wildcard address? */
 587 static int sctp_v6_is_any(const union sctp_addr *addr)
 588 {
 589         return ipv6_addr_any(&addr->v6.sin6_addr);
 590 }
 591
 592 /* Should this be available for binding?   */
 593 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 594 {
 595         int type;
 596         struct net *net = sock_net(&sp->inet.sk);
 597         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 598
 599         type = ipv6_addr_type(in6);
 600         if (IPV6_ADDR_ANY == type)
 601                 return 1;
 602         if (type == IPV6_ADDR_MAPPED) {
 603                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 604                         return 0;
 605                 sctp_v6_map_v4(addr);
 606                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 607         }
 608         if (!(type & IPV6_ADDR_UNICAST))
 609                 return 0;
 610
 611         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 612                 ipv6_chk_addr(net, in6, NULL, 0);
 613 }
 614
 615 /* This function checks if the address is a valid address to be used for
 616  * SCTP.
 617  *
 618  * Output:
 619  * Return 0 - If the address is a non-unicast or an illegal address.
 620  * Return 1 - If the address is a unicast.
 621  */
 622 static int sctp_v6_addr_valid(union sctp_addr *addr,
 623                               struct sctp_sock *sp,
 624                               const struct sk_buff *skb)
 625 {
 626         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 627
 628         /* Support v4-mapped-v6 address. */
 629         if (ret == IPV6_ADDR_MAPPED) {
 630                 /* Note: This routine is used in input, so v4-mapped-v6
 631                  * are disallowed here when there is no sctp_sock.
 632                  */
 633                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 634                         return 0;
 635                 sctp_v6_map_v4(addr);
 636                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 637         }
 638
 639         /* Is this a non-unicast address */
 640         if (!(ret & IPV6_ADDR_UNICAST))
 641                 return 0;
 642
 643         return 1;
 644 }
 645
 646 /* What is the scope of 'addr'?  */
 647 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 648 {
 649         enum sctp_scope retval;
 650         int v6scope;
 651
 652         /* The IPv6 scope is really a set of bit fields.
 653          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 654          */
 655
 656         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 657         switch (v6scope) {
 658         case IFA_HOST:
 659                 retval = SCTP_SCOPE_LOOPBACK;
 660                 break;
 661         case IFA_LINK:
 662                 retval = SCTP_SCOPE_LINK;
 663                 break;
 664         case IFA_SITE:
 665                 retval = SCTP_SCOPE_PRIVATE;
 666                 break;
 667         default:
 668                 retval = SCTP_SCOPE_GLOBAL;
 669                 break;
 670         }
 671
 672         return retval;
 673 }
 674
 675 /* Create and initialize a new sk for the socket to be returned by accept(). */
 676 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 677                                              struct sctp_association *asoc,
 678                                              bool kern)
 679 {
 680         struct sock *newsk;
 681         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 682         struct sctp6_sock *newsctp6sk;
 683         struct ipv6_txoptions *opt;
 684
 685         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 686         if (!newsk)
 687                 goto out;
 688
 689         sock_init_data(NULL, newsk);
 690
 691         sctp_copy_sock(newsk, sk, asoc);
 692         sock_reset_flag(sk, SOCK_ZAPPED);
 693
 694         newsctp6sk = (struct sctp6_sock *)newsk;
 695         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 696
 697         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 698
 699         newnp = inet6_sk(newsk);
 700
 701         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 702         newnp->ipv6_mc_list = NULL;
 703         newnp->ipv6_ac_list = NULL;
 704         newnp->ipv6_fl_list = NULL;
 705
 706         rcu_read_lock();
 707         opt = rcu_dereference(np->opt);
 708         if (opt)
 709                 opt = ipv6_dup_options(newsk, opt);
 710         RCU_INIT_POINTER(newnp->opt, opt);
 711         rcu_read_unlock();
 712
 713         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 714          * and getpeername().
 715          */
 716         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 717
 718         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 719
 720         sk_refcnt_debug_inc(newsk);
 721
 722         if (newsk->sk_prot->init(newsk)) {
 723                 sk_common_release(newsk);
 724                 newsk = NULL;
 725         }
 726
 727 out:
 728         return newsk;
 729 }
 730
 731 /* Format a sockaddr for return to user space. This makes sure the return is
 732  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 733  */
 734 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 735 {
 736         if (sp->v4mapped) {
 737                 if (addr->sa.sa_family == AF_INET)
 738                         sctp_v4_map_v6(addr);
 739         } else {
 740                 if (addr->sa.sa_family == AF_INET6 &&
 741                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 742                         sctp_v6_map_v4(addr);
 743         }
 744
 745         if (addr->sa.sa_family == AF_INET) {
 746                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 747                 return sizeof(struct sockaddr_in);
 748         }
 749         return sizeof(struct sockaddr_in6);
 750 }
 751
 752 /* Where did this skb come from?  */
 753 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 754 {
 755         return IP6CB(skb)->iif;
 756 }
 757
 758 /* Was this packet marked by Explicit Congestion Notification? */
 759 static int sctp_v6_is_ce(const struct sk_buff *skb)
 760 {
 761         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 762 }
 763
 764 /* Dump the v6 addr to the seq file. */
 765 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 766 {
 767         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 768 }
 769
 770 static void sctp_v6_ecn_capable(struct sock *sk)
 771 {
 772         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 773 }
 774
 775 /* Initialize a PF_INET msgname from a ulpevent. */
 776 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 777                                      char *msgname, int *addrlen)
 778 {
 779         union sctp_addr *addr;
 780         struct sctp_association *asoc;
 781         union sctp_addr *paddr;
 782
 783         if (!msgname)
 784                 return;
 785
 786         addr = (union sctp_addr *)msgname;
 787         asoc = event->asoc;
 788         paddr = &asoc->peer.primary_addr;
 789
 790         if (paddr->sa.sa_family == AF_INET) {
 791                 addr->v4.sin_family = AF_INET;
 792                 addr->v4.sin_port = htons(asoc->peer.port);
 793                 addr->v4.sin_addr = paddr->v4.sin_addr;
 794         } else {
 795                 addr->v6.sin6_family = AF_INET6;
 796                 addr->v6.sin6_flowinfo = 0;
 797                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 798                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 799                 else
 800                         addr->v6.sin6_scope_id = 0;
 801                 addr->v6.sin6_port = htons(asoc->peer.port);
 802                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 803         }
 804
 805         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 806 }
 807
 808 /* Initialize a msg_name from an inbound skb. */
 809 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 810                                    int *addr_len)
 811 {
 812         union sctp_addr *addr;
 813         struct sctphdr *sh;
 814
 815         if (!msgname)
 816                 return;
 817
 818         addr = (union sctp_addr *)msgname;
 819         sh = sctp_hdr(skb);
 820
 821         if (ip_hdr(skb)->version == 4) {
 822                 addr->v4.sin_family = AF_INET;
 823                 addr->v4.sin_port = sh->source;
 824                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 825         } else {
 826                 addr->v6.sin6_family = AF_INET6;
 827                 addr->v6.sin6_flowinfo = 0;
 828                 addr->v6.sin6_port = sh->source;
 829                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 830                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 831                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 832                 else
 833                         addr->v6.sin6_scope_id = 0;
 834         }
 835
 836         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 837 }
 838
 839 /* Do we support this AF? */
 840 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 841 {
 842         switch (family) {
 843         case AF_INET6:
 844                 return 1;
 845         /* v4-mapped-v6 addresses */
 846         case AF_INET:
 847                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 848                         return 1;
 849         default:
 850                 return 0;
 851         }
 852 }
 853
 854 /* Address matching with wildcards allowed.  This extra level
 855  * of indirection lets us choose whether a PF_INET6 should
 856  * disallow any v4 addresses if we so choose.
 857  */
 858 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 859                                const union sctp_addr *addr2,
 860                                struct sctp_sock *opt)
 861 {
 862         struct sock *sk = sctp_opt2sk(opt);
 863         struct sctp_af *af1, *af2;
 864
 865         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 866         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 867
 868         if (!af1 || !af2)
 869                 return 0;
 870
 871         /* If the socket is IPv6 only, v4 addrs will not match */
 872         if (__ipv6_only_sock(sk) && af1 != af2)
 873                 return 0;
 874
 875         /* Today, wildcard AF_INET/AF_INET6. */
 876         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 877                 return 1;
 878
 879         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 880                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 881
 882         return __sctp_v6_cmp_addr(addr1, addr2);
 883 }
 884
 885 /* Verify that the provided sockaddr looks bindable.   Common verification,
 886  * has already been taken care of.
 887  */
 888 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 889 {
 890         struct sctp_af *af;
 891
 892         /* ASSERT: address family has already been verified. */
 893         if (addr->sa.sa_family != AF_INET6)
 894                 af = sctp_get_af_specific(addr->sa.sa_family);
 895         else {
 896                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 897                 struct net_device *dev;
 898
 899                 if (type & IPV6_ADDR_LINKLOCAL) {
 900                         struct net *net;
 901                         if (!addr->v6.sin6_scope_id)
 902                                 return 0;
 903                         net = sock_net(&opt->inet.sk);
 904                         rcu_read_lock();
 905                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 906                         if (!dev || !(opt->inet.freebind ||
 907                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 908                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 909                                                     dev, 0))) {
 910                                 rcu_read_unlock();
 911                                 return 0;
 912                         }
 913                         rcu_read_unlock();
 914                 }
 915
 916                 af = opt->pf->af;
 917         }
 918         return af->available(addr, opt);
 919 }
 920
 921 /* Verify that the provided sockaddr looks sendable.   Common verification,
 922  * has already been taken care of.
 923  */
 924 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 925 {
 926         struct sctp_af *af = NULL;
 927
 928         /* ASSERT: address family has already been verified. */
 929         if (addr->sa.sa_family != AF_INET6)
 930                 af = sctp_get_af_specific(addr->sa.sa_family);
 931         else {
 932                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 933                 struct net_device *dev;
 934
 935                 if (type & IPV6_ADDR_LINKLOCAL) {
 936                         if (!addr->v6.sin6_scope_id)
 937                                 return 0;
 938                         rcu_read_lock();
 939                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 940                                                    addr->v6.sin6_scope_id);
 941                         rcu_read_unlock();
 942                         if (!dev)
 943                                 return 0;
 944                 }
 945                 af = opt->pf->af;
 946         }
 947
 948         return af != NULL;
 949 }
 950
 951 /* Fill in Supported Address Type information for INIT and INIT-ACK
 952  * chunks.   Note: In the future, we may want to look at sock options
 953  * to determine whether a PF_INET6 socket really wants to have IPV4
 954  * addresses.
 955  * Returns number of addresses supported.
 956  */
 957 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 958                                       __be16 *types)
 959 {
 960         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 961         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 962                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 963                 return 2;
 964         }
 965         return 1;
 966 }
 967
 968 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 969 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 970                         int *uaddr_len, int peer)
 971 {
 972         int rc;
 973
 974         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 975
 976         if (rc != 0)
 977                 return rc;
 978
 979         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 980                                           (union sctp_addr *)uaddr);
 981
 982         return rc;
 983 }
 984
 985 static const struct proto_ops inet6_seqpacket_ops = {
 986         .family            = PF_INET6,
 987         .owner             = THIS_MODULE,
 988         .release           = inet6_release,
 989         .bind              = inet6_bind,
 990         .connect           = sctp_inet_connect,
 991         .socketpair        = sock_no_socketpair,
 992         .accept            = inet_accept,
 993         .getname           = sctp_getname,
 994         .poll              = sctp_poll,
 995         .ioctl             = inet6_ioctl,
 996         .listen            = sctp_inet_listen,
 997         .shutdown          = inet_shutdown,
 998         .setsockopt        = sock_common_setsockopt,
 999         .getsockopt        = sock_common_getsockopt,
1000         .sendmsg           = inet_sendmsg,
1001         .recvmsg           = inet_recvmsg,
1002         .mmap              = sock_no_mmap,
1003 #ifdef CONFIG_COMPAT
1004         .compat_setsockopt = compat_sock_common_setsockopt,
1005         .compat_getsockopt = compat_sock_common_getsockopt,
1006 #endif
1007 };
1008
1009 static struct inet_protosw sctpv6_seqpacket_protosw = {
1010         .type          = SOCK_SEQPACKET,
1011         .protocol      = IPPROTO_SCTP,
1012         .prot          = &sctpv6_prot,
1013         .ops           = &inet6_seqpacket_ops,
1014         .flags         = SCTP_PROTOSW_FLAG
1015 };
1016 static struct inet_protosw sctpv6_stream_protosw = {
1017         .type          = SOCK_STREAM,
1018         .protocol      = IPPROTO_SCTP,
1019         .prot          = &sctpv6_prot,
1020         .ops           = &inet6_seqpacket_ops,
1021         .flags         = SCTP_PROTOSW_FLAG,
1022 };
1023
1024 static int sctp6_rcv(struct sk_buff *skb)
1025 {
1026         return sctp_rcv(skb) ? -1 : 0;
1027 }
1028
1029 static const struct inet6_protocol sctpv6_protocol = {
1030         .handler      = sctp6_rcv,
1031         .err_handler  = sctp_v6_err,
1032         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1033 };
1034
1035 static struct sctp_af sctp_af_inet6 = {
1036         .sa_family         = AF_INET6,
1037         .sctp_xmit         = sctp_v6_xmit,
1038         .setsockopt        = ipv6_setsockopt,
1039         .getsockopt        = ipv6_getsockopt,
1040         .get_dst           = sctp_v6_get_dst,
1041         .get_saddr         = sctp_v6_get_saddr,
1042         .copy_addrlist     = sctp_v6_copy_addrlist,
1043         .from_skb          = sctp_v6_from_skb,
1044         .from_sk           = sctp_v6_from_sk,
1045         .from_addr_param   = sctp_v6_from_addr_param,
1046         .to_addr_param     = sctp_v6_to_addr_param,
1047         .cmp_addr          = sctp_v6_cmp_addr,
1048         .scope             = sctp_v6_scope,
1049         .addr_valid        = sctp_v6_addr_valid,
1050         .inaddr_any        = sctp_v6_inaddr_any,
1051         .is_any            = sctp_v6_is_any,
1052         .available         = sctp_v6_available,
1053         .skb_iif           = sctp_v6_skb_iif,
1054         .is_ce             = sctp_v6_is_ce,
1055         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1056         .ecn_capable       = sctp_v6_ecn_capable,
1057         .net_header_len    = sizeof(struct ipv6hdr),
1058         .sockaddr_len      = sizeof(struct sockaddr_in6),
1059 #ifdef CONFIG_COMPAT
1060         .compat_setsockopt = compat_ipv6_setsockopt,
1061         .compat_getsockopt = compat_ipv6_getsockopt,
1062 #endif
1063 };
1064
1065 static struct sctp_pf sctp_pf_inet6 = {
1066         .event_msgname = sctp_inet6_event_msgname,
1067         .skb_msgname   = sctp_inet6_skb_msgname,
1068         .af_supported  = sctp_inet6_af_supported,
1069         .cmp_addr      = sctp_inet6_cmp_addr,
1070         .bind_verify   = sctp_inet6_bind_verify,
1071         .send_verify   = sctp_inet6_send_verify,
1072         .supported_addrs = sctp_inet6_supported_addrs,
1073         .create_accept_sk = sctp_v6_create_accept_sk,
1074         .addr_to_user  = sctp_v6_addr_to_user,
1075         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1076         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1077         .af            = &sctp_af_inet6,
1078 };
1079
1080 /* Initialize IPv6 support and register with socket layer.  */
1081 void sctp_v6_pf_init(void)
1082 {
1083         /* Register the SCTP specific PF_INET6 functions. */
1084         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1085
1086         /* Register the SCTP specific AF_INET6 functions. */
1087         sctp_register_af(&sctp_af_inet6);
1088 }
1089
1090 void sctp_v6_pf_exit(void)
1091 {
1092         list_del(&sctp_af_inet6.list);
1093 }
1094
1095 /* Initialize IPv6 support and register with socket layer.  */
1096 int sctp_v6_protosw_init(void)
1097 {
1098         int rc;
1099
1100         rc = proto_register(&sctpv6_prot, 1);
1101         if (rc)
1102                 return rc;
1103
1104         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1105         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1106         inet6_register_protosw(&sctpv6_stream_protosw);
1107
1108         return 0;
1109 }
1110
1111 void sctp_v6_protosw_exit(void)
1112 {
1113         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1114         inet6_unregister_protosw(&sctpv6_stream_protosw);
1115         proto_unregister(&sctpv6_prot);
1116 }
1117
1118
1119 /* Register with inet6 layer. */
1120 int sctp_v6_add_protocol(void)
1121 {
1122         /* Register notifier for inet6 address additions/deletions. */
1123         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1124
1125         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1126                 return -EAGAIN;
1127
1128         return 0;
1129 }
1130
1131 /* Unregister with inet6 layer. */
1132 void sctp_v6_del_protocol(void)
1133 {
1134         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1135         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1136 }