kernel/net/sctp/ipv6.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2002, 2004
   3  * Copyright (c) 2001 Nokia, Inc.
   4  * Copyright (c) 2001 La Monte H.P. Yarroll
   5  * Copyright (c) 2002-2003 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * This SCTP implementation is free software;
  12  * you can redistribute it and/or modify it under the terms of
  13  * the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This SCTP implementation is distributed in the hope that it
  18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19  *                 ************************
  20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21  * See the GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with GNU CC; see the file COPYING.  If not, see
  25  * <http://www.gnu.org/licenses/>.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    Le Yanqun             <yanqun.le@nokia.com>
  33  *    Hui Huang             <hui.huang@nokia.com>
  34  *    La Monte H.P. Yarroll <piggy@acm.org>
  35  *    Sridhar Samudrala     <sri@us.ibm.com>
  36  *    Jon Grimm             <jgrimm@us.ibm.com>
  37  *    Ardelle Fan           <ardelle.fan@intel.com>
  38  *
  39  * Based on:
  40  *      linux/net/ipv6/tcp_ipv6.c
  41  */
  42
  43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  44
  45 #include <linux/module.h>
  46 #include <linux/errno.h>
  47 #include <linux/types.h>
  48 #include <linux/socket.h>
  49 #include <linux/sockios.h>
  50 #include <linux/net.h>
  51 #include <linux/in.h>
  52 #include <linux/in6.h>
  53 #include <linux/netdevice.h>
  54 #include <linux/init.h>
  55 #include <linux/ipsec.h>
  56 #include <linux/slab.h>
  57
  58 #include <linux/ipv6.h>
  59 #include <linux/icmpv6.h>
  60 #include <linux/random.h>
  61 #include <linux/seq_file.h>
  62
  63 #include <net/protocol.h>
  64 #include <net/ndisc.h>
  65 #include <net/ip.h>
  66 #include <net/ipv6.h>
  67 #include <net/transp_v6.h>
  68 #include <net/addrconf.h>
  69 #include <net/ip6_route.h>
  70 #include <net/inet_common.h>
  71 #include <net/inet_ecn.h>
  72 #include <net/sctp/sctp.h>
  73
  74 #include <asm/uaccess.h>
  75
  76 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  77                                          union sctp_addr *s2);
  78 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  79                               __be16 port);
  80 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  81                             const union sctp_addr *addr2);
  82
  83 /* Event handler for inet6 address addition/deletion events.
  84  * The sctp_local_addr_list needs to be protocted by a spin lock since
  85  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  86  * time and thus corrupt the list.
  87  * The reader side is protected with RCU.
  88  */
  89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  90                                 void *ptr)
  91 {
  92         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  93         struct sctp_sockaddr_entry *addr = NULL;
  94         struct sctp_sockaddr_entry *temp;
  95         struct net *net = dev_net(ifa->idev->dev);
  96         int found = 0;
  97
  98         switch (ev) {
  99         case NETDEV_UP:
 100                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 101                 if (addr) {
 102                         addr->a.v6.sin6_family = AF_INET6;
 103                         addr->a.v6.sin6_port = 0;
 104                         addr->a.v6.sin6_addr = ifa->addr;
 105                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 106                         addr->valid = 1;
 107                         spin_lock_bh(&net->sctp.local_addr_lock);
 108                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 109                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 110                         spin_unlock_bh(&net->sctp.local_addr_lock);
 111                 }
 112                 break;
 113         case NETDEV_DOWN:
 114                 spin_lock_bh(&net->sctp.local_addr_lock);
 115                 list_for_each_entry_safe(addr, temp,
 116                                         &net->sctp.local_addr_list, list) {
 117                         if (addr->a.sa.sa_family == AF_INET6 &&
 118                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 119                                                 &ifa->addr)) {
 120                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 121                                 found = 1;
 122                                 addr->valid = 0;
 123                                 list_del_rcu(&addr->list);
 124                                 break;
 125                         }
 126                 }
 127                 spin_unlock_bh(&net->sctp.local_addr_lock);
 128                 if (found)
 129                         kfree_rcu(addr, rcu);
 130                 break;
 131         }
 132
 133         return NOTIFY_DONE;
 134 }
 135
 136 static struct notifier_block sctp_inet6addr_notifier = {
 137         .notifier_call = sctp_inet6addr_event,
 138 };
 139
 140 /* ICMP error handler. */
 141 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 142                         u8 type, u8 code, int offset, __be32 info)
 143 {
 144         struct inet6_dev *idev;
 145         struct sock *sk;
 146         struct sctp_association *asoc;
 147         struct sctp_transport *transport;
 148         struct ipv6_pinfo *np;
 149         __u16 saveip, savesctp;
 150         int err;
 151         struct net *net = dev_net(skb->dev);
 152
 153         idev = in6_dev_get(skb->dev);
 154
 155         /* Fix up skb to look at the embedded net header. */
 156         saveip   = skb->network_header;
 157         savesctp = skb->transport_header;
 158         skb_reset_network_header(skb);
 159         skb_set_transport_header(skb, offset);
 160         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 161         /* Put back, the original pointers. */
 162         skb->network_header   = saveip;
 163         skb->transport_header = savesctp;
 164         if (!sk) {
 165                 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_INERRORS);
 166                 goto out;
 167         }
 168
 169         /* Warning:  The sock lock is held.  Remember to call
 170          * sctp_err_finish!
 171          */
 172
 173         switch (type) {
 174         case ICMPV6_PKT_TOOBIG:
 175                 if (ip6_sk_accept_pmtu(sk))
 176                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 177                 goto out_unlock;
 178         case ICMPV6_PARAMPROB:
 179                 if (ICMPV6_UNK_NEXTHDR == code) {
 180                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 181                         goto out_unlock;
 182                 }
 183                 break;
 184         case NDISC_REDIRECT:
 185                 sctp_icmp_redirect(sk, transport, skb);
 186                 goto out_unlock;
 187         default:
 188                 break;
 189         }
 190
 191         np = inet6_sk(sk);
 192         icmpv6_err_convert(type, code, &err);
 193         if (!sock_owned_by_user(sk) && np->recverr) {
 194                 sk->sk_err = err;
 195                 sk->sk_error_report(sk);
 196         } else {  /* Only an error on timeout */
 197                 sk->sk_err_soft = err;
 198         }
 199
 200 out_unlock:
 201         sctp_err_finish(sk, asoc);
 202 out:
 203         if (likely(idev != NULL))
 204                 in6_dev_put(idev);
 205 }
 206
 207 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 208 {
 209         struct sock *sk = skb->sk;
 210         struct ipv6_pinfo *np = inet6_sk(sk);
 211         struct flowi6 *fl6 = &transport->fl.u.ip6;
 212
 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         return ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 224 }
 225
 226 /* Returns the dst cache entry for the given source and destination ip
 227  * addresses.
 228  */
 229 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 230                             struct flowi *fl, struct sock *sk)
 231 {
 232         struct sctp_association *asoc = t->asoc;
 233         struct dst_entry *dst = NULL;
 234         struct flowi6 *fl6 = &fl->u.ip6;
 235         struct sctp_bind_addr *bp;
 236         struct ipv6_pinfo *np = inet6_sk(sk);
 237         struct sctp_sockaddr_entry *laddr;
 238         union sctp_addr *baddr = NULL;
 239         union sctp_addr *daddr = &t->ipaddr;
 240         union sctp_addr dst_saddr;
 241         struct in6_addr *final_p, final;
 242         __u8 matchlen = 0;
 243         __u8 bmatchlen;
 244         sctp_scope_t scope;
 245
 246         memset(fl6, 0, sizeof(struct flowi6));
 247         fl6->daddr = daddr->v6.sin6_addr;
 248         fl6->fl6_dport = daddr->v6.sin6_port;
 249         fl6->flowi6_proto = IPPROTO_SCTP;
 250         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 251                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 252
 253         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 254
 255         if (asoc)
 256                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 257
 258         if (saddr) {
 259                 fl6->saddr = saddr->v6.sin6_addr;
 260                 fl6->fl6_sport = saddr->v6.sin6_port;
 261
 262                 pr_debug("src=%pI6 - ", &fl6->saddr);
 263         }
 264
 265         final_p = fl6_update_dst(fl6, np->opt, &final);
 266         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 267         if (!asoc || saddr)
 268                 goto out;
 269
 270         bp = &asoc->base.bind_addr;
 271         scope = sctp_scope(daddr);
 272         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 273          * to see if we can use it.
 274          */
 275         if (!IS_ERR(dst)) {
 276                 /* Walk through the bind address list and look for a bind
 277                  * address that matches the source address of the returned dst.
 278                  */
 279                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 280                 rcu_read_lock();
 281                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 282                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 283                             (laddr->state != SCTP_ADDR_SRC &&
 284                              !asoc->src_out_of_asoc_ok))
 285                                 continue;
 286
 287                         /* Do not compare against v4 addrs */
 288                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 289                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 290                                 rcu_read_unlock();
 291                                 goto out;
 292                         }
 293                 }
 294                 rcu_read_unlock();
 295                 /* None of the bound addresses match the source address of the
 296                  * dst. So release it.
 297                  */
 298                 dst_release(dst);
 299                 dst = NULL;
 300         }
 301
 302         /* Walk through the bind address list and try to get the
 303          * best source address for a given destination.
 304          */
 305         rcu_read_lock();
 306         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 307                 if (!laddr->valid)
 308                         continue;
 309                 if ((laddr->state == SCTP_ADDR_SRC) &&
 310                     (laddr->a.sa.sa_family == AF_INET6) &&
 311                     (scope <= sctp_scope(&laddr->a))) {
 312                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 313                         if (!baddr || (matchlen < bmatchlen)) {
 314                                 baddr = &laddr->a;
 315                                 matchlen = bmatchlen;
 316                         }
 317                 }
 318         }
 319         rcu_read_unlock();
 320
 321         if (baddr) {
 322                 fl6->saddr = baddr->v6.sin6_addr;
 323                 fl6->fl6_sport = baddr->v6.sin6_port;
 324                 final_p = fl6_update_dst(fl6, np->opt, &final);
 325                 dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 326         }
 327
 328 out:
 329         if (!IS_ERR_OR_NULL(dst)) {
 330                 struct rt6_info *rt;
 331
 332                 rt = (struct rt6_info *)dst;
 333                 t->dst = dst;
 334                 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
 335                 pr_debug("rt6_dst:%pI6 rt6_src:%pI6\n", &rt->rt6i_dst.addr,
 336                          &fl6->saddr);
 337         } else {
 338                 t->dst = NULL;
 339
 340                 pr_debug("no route\n");
 341         }
 342 }
 343
 344 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 345  * addresses.
 346  */
 347 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 348                                          union sctp_addr *s2)
 349 {
 350         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 351 }
 352
 353 /* Fills in the source address(saddr) based on the destination address(daddr)
 354  * and asoc's bind address list.
 355  */
 356 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 357                               struct sctp_transport *t,
 358                               struct flowi *fl)
 359 {
 360         struct flowi6 *fl6 = &fl->u.ip6;
 361         union sctp_addr *saddr = &t->saddr;
 362
 363         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 364
 365         if (t->dst) {
 366                 saddr->v6.sin6_family = AF_INET6;
 367                 saddr->v6.sin6_addr = fl6->saddr;
 368         }
 369 }
 370
 371 /* Make a copy of all potential local addresses. */
 372 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 373                                   struct net_device *dev)
 374 {
 375         struct inet6_dev *in6_dev;
 376         struct inet6_ifaddr *ifp;
 377         struct sctp_sockaddr_entry *addr;
 378
 379         rcu_read_lock();
 380         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 381                 rcu_read_unlock();
 382                 return;
 383         }
 384
 385         read_lock_bh(&in6_dev->lock);
 386         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 387                 /* Add the address to the local list.  */
 388                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 389                 if (addr) {
 390                         addr->a.v6.sin6_family = AF_INET6;
 391                         addr->a.v6.sin6_port = 0;
 392                         addr->a.v6.sin6_addr = ifp->addr;
 393                         addr->a.v6.sin6_scope_id = dev->ifindex;
 394                         addr->valid = 1;
 395                         INIT_LIST_HEAD(&addr->list);
 396                         list_add_tail(&addr->list, addrlist);
 397                 }
 398         }
 399
 400         read_unlock_bh(&in6_dev->lock);
 401         rcu_read_unlock();
 402 }
 403
 404 /* Initialize a sockaddr_storage from in incoming skb. */
 405 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 406                              int is_saddr)
 407 {
 408         __be16 *port;
 409         struct sctphdr *sh;
 410
 411         port = &addr->v6.sin6_port;
 412         addr->v6.sin6_family = AF_INET6;
 413         addr->v6.sin6_flowinfo = 0; /* FIXME */
 414         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 415
 416         sh = sctp_hdr(skb);
 417         if (is_saddr) {
 418                 *port  = sh->source;
 419                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 420         } else {
 421                 *port = sh->dest;
 422                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 423         }
 424 }
 425
 426 /* Initialize an sctp_addr from a socket. */
 427 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 428 {
 429         addr->v6.sin6_family = AF_INET6;
 430         addr->v6.sin6_port = 0;
 431         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 432 }
 433
 434 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 435 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 436 {
 437         if (addr->sa.sa_family == AF_INET) {
 438                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 439                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 440                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 441                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 442                         addr->v4.sin_addr.s_addr;
 443         } else {
 444                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 445         }
 446 }
 447
 448 /* Initialize sk->sk_daddr from sctp_addr. */
 449 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 450 {
 451         if (addr->sa.sa_family == AF_INET) {
 452                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 453                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 454                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 455                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 456         } else {
 457                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 458         }
 459 }
 460
 461 /* Initialize a sctp_addr from an address parameter. */
 462 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 463                                     union sctp_addr_param *param,
 464                                     __be16 port, int iif)
 465 {
 466         addr->v6.sin6_family = AF_INET6;
 467         addr->v6.sin6_port = port;
 468         addr->v6.sin6_flowinfo = 0; /* BUG */
 469         addr->v6.sin6_addr = param->v6.addr;
 470         addr->v6.sin6_scope_id = iif;
 471 }
 472
 473 /* Initialize an address parameter from a sctp_addr and return the length
 474  * of the address parameter.
 475  */
 476 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 477                                  union sctp_addr_param *param)
 478 {
 479         int length = sizeof(sctp_ipv6addr_param_t);
 480
 481         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 482         param->v6.param_hdr.length = htons(length);
 483         param->v6.addr = addr->v6.sin6_addr;
 484
 485         return length;
 486 }
 487
 488 /* Initialize a sctp_addr from struct in6_addr. */
 489 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 490                               __be16 port)
 491 {
 492         addr->sa.sa_family = AF_INET6;
 493         addr->v6.sin6_port = port;
 494         addr->v6.sin6_addr = *saddr;
 495 }
 496
 497 /* Compare addresses exactly.
 498  * v4-mapped-v6 is also in consideration.
 499  */
 500 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 501                             const union sctp_addr *addr2)
 502 {
 503         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 504                 if (addr1->sa.sa_family == AF_INET &&
 505                     addr2->sa.sa_family == AF_INET6 &&
 506                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 507                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 508                             addr2->v6.sin6_addr.s6_addr32[3] ==
 509                             addr1->v4.sin_addr.s_addr)
 510                                 return 1;
 511                 }
 512                 if (addr2->sa.sa_family == AF_INET &&
 513                     addr1->sa.sa_family == AF_INET6 &&
 514                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 515                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 516                             addr1->v6.sin6_addr.s6_addr32[3] ==
 517                             addr2->v4.sin_addr.s_addr)
 518                                 return 1;
 519                 }
 520                 return 0;
 521         }
 522         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 523                 return 0;
 524         /* If this is a linklocal address, compare the scope_id. */
 525         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 526                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 527                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 528                         return 0;
 529                 }
 530         }
 531
 532         return 1;
 533 }
 534
 535 /* Initialize addr struct to INADDR_ANY. */
 536 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 537 {
 538         memset(addr, 0x00, sizeof(union sctp_addr));
 539         addr->v6.sin6_family = AF_INET6;
 540         addr->v6.sin6_port = port;
 541 }
 542
 543 /* Is this a wildcard address? */
 544 static int sctp_v6_is_any(const union sctp_addr *addr)
 545 {
 546         return ipv6_addr_any(&addr->v6.sin6_addr);
 547 }
 548
 549 /* Should this be available for binding?   */
 550 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 551 {
 552         int type;
 553         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 554
 555         type = ipv6_addr_type(in6);
 556         if (IPV6_ADDR_ANY == type)
 557                 return 1;
 558         if (type == IPV6_ADDR_MAPPED) {
 559                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 560                         return 0;
 561                 sctp_v6_map_v4(addr);
 562                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 563         }
 564         if (!(type & IPV6_ADDR_UNICAST))
 565                 return 0;
 566
 567         return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
 568 }
 569
 570 /* This function checks if the address is a valid address to be used for
 571  * SCTP.
 572  *
 573  * Output:
 574  * Return 0 - If the address is a non-unicast or an illegal address.
 575  * Return 1 - If the address is a unicast.
 576  */
 577 static int sctp_v6_addr_valid(union sctp_addr *addr,
 578                               struct sctp_sock *sp,
 579                               const struct sk_buff *skb)
 580 {
 581         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 582
 583         /* Support v4-mapped-v6 address. */
 584         if (ret == IPV6_ADDR_MAPPED) {
 585                 /* Note: This routine is used in input, so v4-mapped-v6
 586                  * are disallowed here when there is no sctp_sock.
 587                  */
 588                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 589                         return 0;
 590                 sctp_v6_map_v4(addr);
 591                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 592         }
 593
 594         /* Is this a non-unicast address */
 595         if (!(ret & IPV6_ADDR_UNICAST))
 596                 return 0;
 597
 598         return 1;
 599 }
 600
 601 /* What is the scope of 'addr'?  */
 602 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 603 {
 604         int v6scope;
 605         sctp_scope_t retval;
 606
 607         /* The IPv6 scope is really a set of bit fields.
 608          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 609          */
 610
 611         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 612         switch (v6scope) {
 613         case IFA_HOST:
 614                 retval = SCTP_SCOPE_LOOPBACK;
 615                 break;
 616         case IFA_LINK:
 617                 retval = SCTP_SCOPE_LINK;
 618                 break;
 619         case IFA_SITE:
 620                 retval = SCTP_SCOPE_PRIVATE;
 621                 break;
 622         default:
 623                 retval = SCTP_SCOPE_GLOBAL;
 624                 break;
 625         }
 626
 627         return retval;
 628 }
 629
 630 /* Create and initialize a new sk for the socket to be returned by accept(). */
 631 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 632                                              struct sctp_association *asoc)
 633 {
 634         struct sock *newsk;
 635         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 636         struct sctp6_sock *newsctp6sk;
 637
 638         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 639         if (!newsk)
 640                 goto out;
 641
 642         sock_init_data(NULL, newsk);
 643
 644         sctp_copy_sock(newsk, sk, asoc);
 645         sock_reset_flag(sk, SOCK_ZAPPED);
 646
 647         newsctp6sk = (struct sctp6_sock *)newsk;
 648         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 649
 650         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 651
 652         newnp = inet6_sk(newsk);
 653
 654         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 655
 656         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 657          * and getpeername().
 658          */
 659         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 660
 661         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 662
 663         sk_refcnt_debug_inc(newsk);
 664
 665         if (newsk->sk_prot->init(newsk)) {
 666                 sk_common_release(newsk);
 667                 newsk = NULL;
 668         }
 669
 670 out:
 671         return newsk;
 672 }
 673
 674 /* Format a sockaddr for return to user space. This makes sure the return is
 675  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 676  */
 677 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 678 {
 679         if (sp->v4mapped) {
 680                 if (addr->sa.sa_family == AF_INET)
 681                         sctp_v4_map_v6(addr);
 682         } else {
 683                 if (addr->sa.sa_family == AF_INET6 &&
 684                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 685                         sctp_v6_map_v4(addr);
 686         }
 687
 688         if (addr->sa.sa_family == AF_INET)
 689                 return sizeof(struct sockaddr_in);
 690         return sizeof(struct sockaddr_in6);
 691 }
 692
 693 /* Where did this skb come from?  */
 694 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 695 {
 696         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 697         return opt->iif;
 698 }
 699
 700 /* Was this packet marked by Explicit Congestion Notification? */
 701 static int sctp_v6_is_ce(const struct sk_buff *skb)
 702 {
 703         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 704 }
 705
 706 /* Dump the v6 addr to the seq file. */
 707 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 708 {
 709         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 710 }
 711
 712 static void sctp_v6_ecn_capable(struct sock *sk)
 713 {
 714         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 715 }
 716
 717 /* Initialize a PF_INET msgname from a ulpevent. */
 718 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 719                                      char *msgname, int *addrlen)
 720 {
 721         union sctp_addr *addr;
 722         struct sctp_association *asoc;
 723         union sctp_addr *paddr;
 724
 725         if (!msgname)
 726                 return;
 727
 728         addr = (union sctp_addr *)msgname;
 729         asoc = event->asoc;
 730         paddr = &asoc->peer.primary_addr;
 731
 732         if (paddr->sa.sa_family == AF_INET) {
 733                 addr->v4.sin_family = AF_INET;
 734                 addr->v4.sin_port = htons(asoc->peer.port);
 735                 addr->v4.sin_addr = paddr->v4.sin_addr;
 736         } else {
 737                 addr->v6.sin6_family = AF_INET6;
 738                 addr->v6.sin6_flowinfo = 0;
 739                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 740                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 741                 else
 742                         addr->v6.sin6_scope_id = 0;
 743                 addr->v6.sin6_port = htons(asoc->peer.port);
 744                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 745         }
 746
 747         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 748 }
 749
 750 /* Initialize a msg_name from an inbound skb. */
 751 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 752                                    int *addr_len)
 753 {
 754         union sctp_addr *addr;
 755         struct sctphdr *sh;
 756
 757         if (!msgname)
 758                 return;
 759
 760         addr = (union sctp_addr *)msgname;
 761         sh = sctp_hdr(skb);
 762
 763         if (ip_hdr(skb)->version == 4) {
 764                 addr->v4.sin_family = AF_INET;
 765                 addr->v4.sin_port = sh->source;
 766                 addr->v4.sin_addr.s_addr =  ip_hdr(skb)->saddr;
 767         } else {
 768                 addr->v6.sin6_family = AF_INET6;
 769                 addr->v6.sin6_flowinfo = 0;
 770                 addr->v6.sin6_port = sh->source;
 771                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 772                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 773                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 774                         addr->v6.sin6_scope_id = ev->iif;
 775                 }
 776         }
 777
 778         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 779 }
 780
 781 /* Do we support this AF? */
 782 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 783 {
 784         switch (family) {
 785         case AF_INET6:
 786                 return 1;
 787         /* v4-mapped-v6 addresses */
 788         case AF_INET:
 789                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 790                         return 1;
 791         default:
 792                 return 0;
 793         }
 794 }
 795
 796 /* Address matching with wildcards allowed.  This extra level
 797  * of indirection lets us choose whether a PF_INET6 should
 798  * disallow any v4 addresses if we so choose.
 799  */
 800 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 801                                const union sctp_addr *addr2,
 802                                struct sctp_sock *opt)
 803 {
 804         struct sctp_af *af1, *af2;
 805         struct sock *sk = sctp_opt2sk(opt);
 806
 807         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 808         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 809
 810         if (!af1 || !af2)
 811                 return 0;
 812
 813         /* If the socket is IPv6 only, v4 addrs will not match */
 814         if (__ipv6_only_sock(sk) && af1 != af2)
 815                 return 0;
 816
 817         /* Today, wildcard AF_INET/AF_INET6. */
 818         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 819                 return 1;
 820
 821         if (addr1->sa.sa_family != addr2->sa.sa_family)
 822                 return 0;
 823
 824         return af1->cmp_addr(addr1, addr2);
 825 }
 826
 827 /* Verify that the provided sockaddr looks bindable.   Common verification,
 828  * has already been taken care of.
 829  */
 830 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 831 {
 832         struct sctp_af *af;
 833
 834         /* ASSERT: address family has already been verified. */
 835         if (addr->sa.sa_family != AF_INET6)
 836                 af = sctp_get_af_specific(addr->sa.sa_family);
 837         else {
 838                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 839                 struct net_device *dev;
 840
 841                 if (type & IPV6_ADDR_LINKLOCAL) {
 842                         struct net *net;
 843                         if (!addr->v6.sin6_scope_id)
 844                                 return 0;
 845                         net = sock_net(&opt->inet.sk);
 846                         rcu_read_lock();
 847                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 848                         if (!dev ||
 849                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 850                                 rcu_read_unlock();
 851                                 return 0;
 852                         }
 853                         rcu_read_unlock();
 854                 }
 855
 856                 af = opt->pf->af;
 857         }
 858         return af->available(addr, opt);
 859 }
 860
 861 /* Verify that the provided sockaddr looks sendable.   Common verification,
 862  * has already been taken care of.
 863  */
 864 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 865 {
 866         struct sctp_af *af = NULL;
 867
 868         /* ASSERT: address family has already been verified. */
 869         if (addr->sa.sa_family != AF_INET6)
 870                 af = sctp_get_af_specific(addr->sa.sa_family);
 871         else {
 872                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 873                 struct net_device *dev;
 874
 875                 if (type & IPV6_ADDR_LINKLOCAL) {
 876                         if (!addr->v6.sin6_scope_id)
 877                                 return 0;
 878                         rcu_read_lock();
 879                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 880                                                    addr->v6.sin6_scope_id);
 881                         rcu_read_unlock();
 882                         if (!dev)
 883                                 return 0;
 884                 }
 885                 af = opt->pf->af;
 886         }
 887
 888         return af != NULL;
 889 }
 890
 891 /* Fill in Supported Address Type information for INIT and INIT-ACK
 892  * chunks.   Note: In the future, we may want to look at sock options
 893  * to determine whether a PF_INET6 socket really wants to have IPV4
 894  * addresses.
 895  * Returns number of addresses supported.
 896  */
 897 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 898                                       __be16 *types)
 899 {
 900         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 901         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 902                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 903                 return 2;
 904         }
 905         return 1;
 906 }
 907
 908 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 909 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 910                         int *uaddr_len, int peer)
 911 {
 912         int rc;
 913
 914         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 915
 916         if (rc != 0)
 917                 return rc;
 918
 919         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 920                                           (union sctp_addr *)uaddr);
 921
 922         return rc;
 923 }
 924
 925 static const struct proto_ops inet6_seqpacket_ops = {
 926         .family            = PF_INET6,
 927         .owner             = THIS_MODULE,
 928         .release           = inet6_release,
 929         .bind              = inet6_bind,
 930         .connect           = inet_dgram_connect,
 931         .socketpair        = sock_no_socketpair,
 932         .accept            = inet_accept,
 933         .getname           = sctp_getname,
 934         .poll              = sctp_poll,
 935         .ioctl             = inet6_ioctl,
 936         .listen            = sctp_inet_listen,
 937         .shutdown          = inet_shutdown,
 938         .setsockopt        = sock_common_setsockopt,
 939         .getsockopt        = sock_common_getsockopt,
 940         .sendmsg           = inet_sendmsg,
 941         .recvmsg           = sock_common_recvmsg,
 942         .mmap              = sock_no_mmap,
 943 #ifdef CONFIG_COMPAT
 944         .compat_setsockopt = compat_sock_common_setsockopt,
 945         .compat_getsockopt = compat_sock_common_getsockopt,
 946 #endif
 947 };
 948
 949 static struct inet_protosw sctpv6_seqpacket_protosw = {
 950         .type          = SOCK_SEQPACKET,
 951         .protocol      = IPPROTO_SCTP,
 952         .prot          = &sctpv6_prot,
 953         .ops           = &inet6_seqpacket_ops,
 954         .flags         = SCTP_PROTOSW_FLAG
 955 };
 956 static struct inet_protosw sctpv6_stream_protosw = {
 957         .type          = SOCK_STREAM,
 958         .protocol      = IPPROTO_SCTP,
 959         .prot          = &sctpv6_prot,
 960         .ops           = &inet6_seqpacket_ops,
 961         .flags         = SCTP_PROTOSW_FLAG,
 962 };
 963
 964 static int sctp6_rcv(struct sk_buff *skb)
 965 {
 966         return sctp_rcv(skb) ? -1 : 0;
 967 }
 968
 969 static const struct inet6_protocol sctpv6_protocol = {
 970         .handler      = sctp6_rcv,
 971         .err_handler  = sctp_v6_err,
 972         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 973 };
 974
 975 static struct sctp_af sctp_af_inet6 = {
 976         .sa_family         = AF_INET6,
 977         .sctp_xmit         = sctp_v6_xmit,
 978         .setsockopt        = ipv6_setsockopt,
 979         .getsockopt        = ipv6_getsockopt,
 980         .get_dst           = sctp_v6_get_dst,
 981         .get_saddr         = sctp_v6_get_saddr,
 982         .copy_addrlist     = sctp_v6_copy_addrlist,
 983         .from_skb          = sctp_v6_from_skb,
 984         .from_sk           = sctp_v6_from_sk,
 985         .from_addr_param   = sctp_v6_from_addr_param,
 986         .to_addr_param     = sctp_v6_to_addr_param,
 987         .cmp_addr          = sctp_v6_cmp_addr,
 988         .scope             = sctp_v6_scope,
 989         .addr_valid        = sctp_v6_addr_valid,
 990         .inaddr_any        = sctp_v6_inaddr_any,
 991         .is_any            = sctp_v6_is_any,
 992         .available         = sctp_v6_available,
 993         .skb_iif           = sctp_v6_skb_iif,
 994         .is_ce             = sctp_v6_is_ce,
 995         .seq_dump_addr     = sctp_v6_seq_dump_addr,
 996         .ecn_capable       = sctp_v6_ecn_capable,
 997         .net_header_len    = sizeof(struct ipv6hdr),
 998         .sockaddr_len      = sizeof(struct sockaddr_in6),
 999 #ifdef CONFIG_COMPAT
1000         .compat_setsockopt = compat_ipv6_setsockopt,
1001         .compat_getsockopt = compat_ipv6_getsockopt,
1002 #endif
1003 };
1004
1005 static struct sctp_pf sctp_pf_inet6 = {
1006         .event_msgname = sctp_inet6_event_msgname,
1007         .skb_msgname   = sctp_inet6_skb_msgname,
1008         .af_supported  = sctp_inet6_af_supported,
1009         .cmp_addr      = sctp_inet6_cmp_addr,
1010         .bind_verify   = sctp_inet6_bind_verify,
1011         .send_verify   = sctp_inet6_send_verify,
1012         .supported_addrs = sctp_inet6_supported_addrs,
1013         .create_accept_sk = sctp_v6_create_accept_sk,
1014         .addr_to_user  = sctp_v6_addr_to_user,
1015         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1016         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1017         .af            = &sctp_af_inet6,
1018 };
1019
1020 /* Initialize IPv6 support and register with socket layer.  */
1021 void sctp_v6_pf_init(void)
1022 {
1023         /* Register the SCTP specific PF_INET6 functions. */
1024         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1025
1026         /* Register the SCTP specific AF_INET6 functions. */
1027         sctp_register_af(&sctp_af_inet6);
1028 }
1029
1030 void sctp_v6_pf_exit(void)
1031 {
1032         list_del(&sctp_af_inet6.list);
1033 }
1034
1035 /* Initialize IPv6 support and register with socket layer.  */
1036 int sctp_v6_protosw_init(void)
1037 {
1038         int rc;
1039
1040         rc = proto_register(&sctpv6_prot, 1);
1041         if (rc)
1042                 return rc;
1043
1044         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1045         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1046         inet6_register_protosw(&sctpv6_stream_protosw);
1047
1048         return 0;
1049 }
1050
1051 void sctp_v6_protosw_exit(void)
1052 {
1053         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1054         inet6_unregister_protosw(&sctpv6_stream_protosw);
1055         proto_unregister(&sctpv6_prot);
1056 }
1057
1058
1059 /* Register with inet6 layer. */
1060 int sctp_v6_add_protocol(void)
1061 {
1062         /* Register notifier for inet6 address additions/deletions. */
1063         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1064
1065         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1066                 return -EAGAIN;
1067
1068         return 0;
1069 }
1070
1071 /* Unregister with inet6 layer. */
1072 void sctp_v6_del_protocol(void)
1073 {
1074         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1075         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1076 }