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 = rt6_get_cookie(rt);
 335                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 336                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 337                          &fl6->saddr);
 338         } else {
 339                 t->dst = NULL;
 340
 341                 pr_debug("no route\n");
 342         }
 343 }
 344
 345 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 346  * addresses.
 347  */
 348 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 349                                          union sctp_addr *s2)
 350 {
 351         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 352 }
 353
 354 /* Fills in the source address(saddr) based on the destination address(daddr)
 355  * and asoc's bind address list.
 356  */
 357 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 358                               struct sctp_transport *t,
 359                               struct flowi *fl)
 360 {
 361         struct flowi6 *fl6 = &fl->u.ip6;
 362         union sctp_addr *saddr = &t->saddr;
 363
 364         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 365
 366         if (t->dst) {
 367                 saddr->v6.sin6_family = AF_INET6;
 368                 saddr->v6.sin6_addr = fl6->saddr;
 369         }
 370 }
 371
 372 /* Make a copy of all potential local addresses. */
 373 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 374                                   struct net_device *dev)
 375 {
 376         struct inet6_dev *in6_dev;
 377         struct inet6_ifaddr *ifp;
 378         struct sctp_sockaddr_entry *addr;
 379
 380         rcu_read_lock();
 381         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 382                 rcu_read_unlock();
 383                 return;
 384         }
 385
 386         read_lock_bh(&in6_dev->lock);
 387         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 388                 /* Add the address to the local list.  */
 389                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 390                 if (addr) {
 391                         addr->a.v6.sin6_family = AF_INET6;
 392                         addr->a.v6.sin6_port = 0;
 393                         addr->a.v6.sin6_addr = ifp->addr;
 394                         addr->a.v6.sin6_scope_id = dev->ifindex;
 395                         addr->valid = 1;
 396                         INIT_LIST_HEAD(&addr->list);
 397                         list_add_tail(&addr->list, addrlist);
 398                 }
 399         }
 400
 401         read_unlock_bh(&in6_dev->lock);
 402         rcu_read_unlock();
 403 }
 404
 405 /* Initialize a sockaddr_storage from in incoming skb. */
 406 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 407                              int is_saddr)
 408 {
 409         __be16 *port;
 410         struct sctphdr *sh;
 411
 412         port = &addr->v6.sin6_port;
 413         addr->v6.sin6_family = AF_INET6;
 414         addr->v6.sin6_flowinfo = 0; /* FIXME */
 415         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 416
 417         sh = sctp_hdr(skb);
 418         if (is_saddr) {
 419                 *port  = sh->source;
 420                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 421         } else {
 422                 *port = sh->dest;
 423                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 424         }
 425 }
 426
 427 /* Initialize an sctp_addr from a socket. */
 428 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 429 {
 430         addr->v6.sin6_family = AF_INET6;
 431         addr->v6.sin6_port = 0;
 432         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 433 }
 434
 435 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 436 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 437 {
 438         if (addr->sa.sa_family == AF_INET) {
 439                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 440                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 441                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 442                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 443                         addr->v4.sin_addr.s_addr;
 444         } else {
 445                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 446         }
 447 }
 448
 449 /* Initialize sk->sk_daddr from sctp_addr. */
 450 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 451 {
 452         if (addr->sa.sa_family == AF_INET) {
 453                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 454                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 455                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 456                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 457         } else {
 458                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 459         }
 460 }
 461
 462 /* Initialize a sctp_addr from an address parameter. */
 463 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 464                                     union sctp_addr_param *param,
 465                                     __be16 port, int iif)
 466 {
 467         addr->v6.sin6_family = AF_INET6;
 468         addr->v6.sin6_port = port;
 469         addr->v6.sin6_flowinfo = 0; /* BUG */
 470         addr->v6.sin6_addr = param->v6.addr;
 471         addr->v6.sin6_scope_id = iif;
 472 }
 473
 474 /* Initialize an address parameter from a sctp_addr and return the length
 475  * of the address parameter.
 476  */
 477 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 478                                  union sctp_addr_param *param)
 479 {
 480         int length = sizeof(sctp_ipv6addr_param_t);
 481
 482         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 483         param->v6.param_hdr.length = htons(length);
 484         param->v6.addr = addr->v6.sin6_addr;
 485
 486         return length;
 487 }
 488
 489 /* Initialize a sctp_addr from struct in6_addr. */
 490 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 491                               __be16 port)
 492 {
 493         addr->sa.sa_family = AF_INET6;
 494         addr->v6.sin6_port = port;
 495         addr->v6.sin6_addr = *saddr;
 496 }
 497
 498 /* Compare addresses exactly.
 499  * v4-mapped-v6 is also in consideration.
 500  */
 501 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 502                             const union sctp_addr *addr2)
 503 {
 504         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 505                 if (addr1->sa.sa_family == AF_INET &&
 506                     addr2->sa.sa_family == AF_INET6 &&
 507                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 508                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 509                             addr2->v6.sin6_addr.s6_addr32[3] ==
 510                             addr1->v4.sin_addr.s_addr)
 511                                 return 1;
 512                 }
 513                 if (addr2->sa.sa_family == AF_INET &&
 514                     addr1->sa.sa_family == AF_INET6 &&
 515                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 516                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 517                             addr1->v6.sin6_addr.s6_addr32[3] ==
 518                             addr2->v4.sin_addr.s_addr)
 519                                 return 1;
 520                 }
 521                 return 0;
 522         }
 523         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 524                 return 0;
 525         /* If this is a linklocal address, compare the scope_id. */
 526         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 527                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 528                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 529                         return 0;
 530                 }
 531         }
 532
 533         return 1;
 534 }
 535
 536 /* Initialize addr struct to INADDR_ANY. */
 537 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 538 {
 539         memset(addr, 0x00, sizeof(union sctp_addr));
 540         addr->v6.sin6_family = AF_INET6;
 541         addr->v6.sin6_port = port;
 542 }
 543
 544 /* Is this a wildcard address? */
 545 static int sctp_v6_is_any(const union sctp_addr *addr)
 546 {
 547         return ipv6_addr_any(&addr->v6.sin6_addr);
 548 }
 549
 550 /* Should this be available for binding?   */
 551 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 552 {
 553         int type;
 554         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 555
 556         type = ipv6_addr_type(in6);
 557         if (IPV6_ADDR_ANY == type)
 558                 return 1;
 559         if (type == IPV6_ADDR_MAPPED) {
 560                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 561                         return 0;
 562                 sctp_v6_map_v4(addr);
 563                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 564         }
 565         if (!(type & IPV6_ADDR_UNICAST))
 566                 return 0;
 567
 568         return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
 569 }
 570
 571 /* This function checks if the address is a valid address to be used for
 572  * SCTP.
 573  *
 574  * Output:
 575  * Return 0 - If the address is a non-unicast or an illegal address.
 576  * Return 1 - If the address is a unicast.
 577  */
 578 static int sctp_v6_addr_valid(union sctp_addr *addr,
 579                               struct sctp_sock *sp,
 580                               const struct sk_buff *skb)
 581 {
 582         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 583
 584         /* Support v4-mapped-v6 address. */
 585         if (ret == IPV6_ADDR_MAPPED) {
 586                 /* Note: This routine is used in input, so v4-mapped-v6
 587                  * are disallowed here when there is no sctp_sock.
 588                  */
 589                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 590                         return 0;
 591                 sctp_v6_map_v4(addr);
 592                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 593         }
 594
 595         /* Is this a non-unicast address */
 596         if (!(ret & IPV6_ADDR_UNICAST))
 597                 return 0;
 598
 599         return 1;
 600 }
 601
 602 /* What is the scope of 'addr'?  */
 603 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 604 {
 605         int v6scope;
 606         sctp_scope_t retval;
 607
 608         /* The IPv6 scope is really a set of bit fields.
 609          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 610          */
 611
 612         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 613         switch (v6scope) {
 614         case IFA_HOST:
 615                 retval = SCTP_SCOPE_LOOPBACK;
 616                 break;
 617         case IFA_LINK:
 618                 retval = SCTP_SCOPE_LINK;
 619                 break;
 620         case IFA_SITE:
 621                 retval = SCTP_SCOPE_PRIVATE;
 622                 break;
 623         default:
 624                 retval = SCTP_SCOPE_GLOBAL;
 625                 break;
 626         }
 627
 628         return retval;
 629 }
 630
 631 /* Create and initialize a new sk for the socket to be returned by accept(). */
 632 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 633                                              struct sctp_association *asoc)
 634 {
 635         struct sock *newsk;
 636         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 637         struct sctp6_sock *newsctp6sk;
 638
 639         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0);
 640         if (!newsk)
 641                 goto out;
 642
 643         sock_init_data(NULL, newsk);
 644
 645         sctp_copy_sock(newsk, sk, asoc);
 646         sock_reset_flag(sk, SOCK_ZAPPED);
 647
 648         newsctp6sk = (struct sctp6_sock *)newsk;
 649         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 650
 651         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 652
 653         newnp = inet6_sk(newsk);
 654
 655         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 656
 657         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 658          * and getpeername().
 659          */
 660         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 661
 662         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 663
 664         sk_refcnt_debug_inc(newsk);
 665
 666         if (newsk->sk_prot->init(newsk)) {
 667                 sk_common_release(newsk);
 668                 newsk = NULL;
 669         }
 670
 671 out:
 672         return newsk;
 673 }
 674
 675 /* Format a sockaddr for return to user space. This makes sure the return is
 676  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 677  */
 678 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 679 {
 680         if (sp->v4mapped) {
 681                 if (addr->sa.sa_family == AF_INET)
 682                         sctp_v4_map_v6(addr);
 683         } else {
 684                 if (addr->sa.sa_family == AF_INET6 &&
 685                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 686                         sctp_v6_map_v4(addr);
 687         }
 688
 689         if (addr->sa.sa_family == AF_INET)
 690                 return sizeof(struct sockaddr_in);
 691         return sizeof(struct sockaddr_in6);
 692 }
 693
 694 /* Where did this skb come from?  */
 695 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 696 {
 697         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 698         return opt->iif;
 699 }
 700
 701 /* Was this packet marked by Explicit Congestion Notification? */
 702 static int sctp_v6_is_ce(const struct sk_buff *skb)
 703 {
 704         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 705 }
 706
 707 /* Dump the v6 addr to the seq file. */
 708 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 709 {
 710         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 711 }
 712
 713 static void sctp_v6_ecn_capable(struct sock *sk)
 714 {
 715         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 716 }
 717
 718 /* Initialize a PF_INET msgname from a ulpevent. */
 719 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 720                                      char *msgname, int *addrlen)
 721 {
 722         union sctp_addr *addr;
 723         struct sctp_association *asoc;
 724         union sctp_addr *paddr;
 725
 726         if (!msgname)
 727                 return;
 728
 729         addr = (union sctp_addr *)msgname;
 730         asoc = event->asoc;
 731         paddr = &asoc->peer.primary_addr;
 732
 733         if (paddr->sa.sa_family == AF_INET) {
 734                 addr->v4.sin_family = AF_INET;
 735                 addr->v4.sin_port = htons(asoc->peer.port);
 736                 addr->v4.sin_addr = paddr->v4.sin_addr;
 737         } else {
 738                 addr->v6.sin6_family = AF_INET6;
 739                 addr->v6.sin6_flowinfo = 0;
 740                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 741                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 742                 else
 743                         addr->v6.sin6_scope_id = 0;
 744                 addr->v6.sin6_port = htons(asoc->peer.port);
 745                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 746         }
 747
 748         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 749 }
 750
 751 /* Initialize a msg_name from an inbound skb. */
 752 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 753                                    int *addr_len)
 754 {
 755         union sctp_addr *addr;
 756         struct sctphdr *sh;
 757
 758         if (!msgname)
 759                 return;
 760
 761         addr = (union sctp_addr *)msgname;
 762         sh = sctp_hdr(skb);
 763
 764         if (ip_hdr(skb)->version == 4) {
 765                 addr->v4.sin_family = AF_INET;
 766                 addr->v4.sin_port = sh->source;
 767                 addr->v4.sin_addr.s_addr =  ip_hdr(skb)->saddr;
 768         } else {
 769                 addr->v6.sin6_family = AF_INET6;
 770                 addr->v6.sin6_flowinfo = 0;
 771                 addr->v6.sin6_port = sh->source;
 772                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 773                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 774                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 775                         addr->v6.sin6_scope_id = ev->iif;
 776                 }
 777         }
 778
 779         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 780 }
 781
 782 /* Do we support this AF? */
 783 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 784 {
 785         switch (family) {
 786         case AF_INET6:
 787                 return 1;
 788         /* v4-mapped-v6 addresses */
 789         case AF_INET:
 790                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 791                         return 1;
 792         default:
 793                 return 0;
 794         }
 795 }
 796
 797 /* Address matching with wildcards allowed.  This extra level
 798  * of indirection lets us choose whether a PF_INET6 should
 799  * disallow any v4 addresses if we so choose.
 800  */
 801 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 802                                const union sctp_addr *addr2,
 803                                struct sctp_sock *opt)
 804 {
 805         struct sctp_af *af1, *af2;
 806         struct sock *sk = sctp_opt2sk(opt);
 807
 808         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 809         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 810
 811         if (!af1 || !af2)
 812                 return 0;
 813
 814         /* If the socket is IPv6 only, v4 addrs will not match */
 815         if (__ipv6_only_sock(sk) && af1 != af2)
 816                 return 0;
 817
 818         /* Today, wildcard AF_INET/AF_INET6. */
 819         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 820                 return 1;
 821
 822         if (addr1->sa.sa_family != addr2->sa.sa_family)
 823                 return 0;
 824
 825         return af1->cmp_addr(addr1, addr2);
 826 }
 827
 828 /* Verify that the provided sockaddr looks bindable.   Common verification,
 829  * has already been taken care of.
 830  */
 831 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 832 {
 833         struct sctp_af *af;
 834
 835         /* ASSERT: address family has already been verified. */
 836         if (addr->sa.sa_family != AF_INET6)
 837                 af = sctp_get_af_specific(addr->sa.sa_family);
 838         else {
 839                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 840                 struct net_device *dev;
 841
 842                 if (type & IPV6_ADDR_LINKLOCAL) {
 843                         struct net *net;
 844                         if (!addr->v6.sin6_scope_id)
 845                                 return 0;
 846                         net = sock_net(&opt->inet.sk);
 847                         rcu_read_lock();
 848                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 849                         if (!dev ||
 850                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 851                                 rcu_read_unlock();
 852                                 return 0;
 853                         }
 854                         rcu_read_unlock();
 855                 }
 856
 857                 af = opt->pf->af;
 858         }
 859         return af->available(addr, opt);
 860 }
 861
 862 /* Verify that the provided sockaddr looks sendable.   Common verification,
 863  * has already been taken care of.
 864  */
 865 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 866 {
 867         struct sctp_af *af = NULL;
 868
 869         /* ASSERT: address family has already been verified. */
 870         if (addr->sa.sa_family != AF_INET6)
 871                 af = sctp_get_af_specific(addr->sa.sa_family);
 872         else {
 873                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 874                 struct net_device *dev;
 875
 876                 if (type & IPV6_ADDR_LINKLOCAL) {
 877                         if (!addr->v6.sin6_scope_id)
 878                                 return 0;
 879                         rcu_read_lock();
 880                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 881                                                    addr->v6.sin6_scope_id);
 882                         rcu_read_unlock();
 883                         if (!dev)
 884                                 return 0;
 885                 }
 886                 af = opt->pf->af;
 887         }
 888
 889         return af != NULL;
 890 }
 891
 892 /* Fill in Supported Address Type information for INIT and INIT-ACK
 893  * chunks.   Note: In the future, we may want to look at sock options
 894  * to determine whether a PF_INET6 socket really wants to have IPV4
 895  * addresses.
 896  * Returns number of addresses supported.
 897  */
 898 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 899                                       __be16 *types)
 900 {
 901         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 902         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 903                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 904                 return 2;
 905         }
 906         return 1;
 907 }
 908
 909 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 910 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 911                         int *uaddr_len, int peer)
 912 {
 913         int rc;
 914
 915         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 916
 917         if (rc != 0)
 918                 return rc;
 919
 920         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 921                                           (union sctp_addr *)uaddr);
 922
 923         return rc;
 924 }
 925
 926 static const struct proto_ops inet6_seqpacket_ops = {
 927         .family            = PF_INET6,
 928         .owner             = THIS_MODULE,
 929         .release           = inet6_release,
 930         .bind              = inet6_bind,
 931         .connect           = inet_dgram_connect,
 932         .socketpair        = sock_no_socketpair,
 933         .accept            = inet_accept,
 934         .getname           = sctp_getname,
 935         .poll              = sctp_poll,
 936         .ioctl             = inet6_ioctl,
 937         .listen            = sctp_inet_listen,
 938         .shutdown          = inet_shutdown,
 939         .setsockopt        = sock_common_setsockopt,
 940         .getsockopt        = sock_common_getsockopt,
 941         .sendmsg           = inet_sendmsg,
 942         .recvmsg           = sock_common_recvmsg,
 943         .mmap              = sock_no_mmap,
 944 #ifdef CONFIG_COMPAT
 945         .compat_setsockopt = compat_sock_common_setsockopt,
 946         .compat_getsockopt = compat_sock_common_getsockopt,
 947 #endif
 948 };
 949
 950 static struct inet_protosw sctpv6_seqpacket_protosw = {
 951         .type          = SOCK_SEQPACKET,
 952         .protocol      = IPPROTO_SCTP,
 953         .prot          = &sctpv6_prot,
 954         .ops           = &inet6_seqpacket_ops,
 955         .flags         = SCTP_PROTOSW_FLAG
 956 };
 957 static struct inet_protosw sctpv6_stream_protosw = {
 958         .type          = SOCK_STREAM,
 959         .protocol      = IPPROTO_SCTP,
 960         .prot          = &sctpv6_prot,
 961         .ops           = &inet6_seqpacket_ops,
 962         .flags         = SCTP_PROTOSW_FLAG,
 963 };
 964
 965 static int sctp6_rcv(struct sk_buff *skb)
 966 {
 967         return sctp_rcv(skb) ? -1 : 0;
 968 }
 969
 970 static const struct inet6_protocol sctpv6_protocol = {
 971         .handler      = sctp6_rcv,
 972         .err_handler  = sctp_v6_err,
 973         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 974 };
 975
 976 static struct sctp_af sctp_af_inet6 = {
 977         .sa_family         = AF_INET6,
 978         .sctp_xmit         = sctp_v6_xmit,
 979         .setsockopt        = ipv6_setsockopt,
 980         .getsockopt        = ipv6_getsockopt,
 981         .get_dst           = sctp_v6_get_dst,
 982         .get_saddr         = sctp_v6_get_saddr,
 983         .copy_addrlist     = sctp_v6_copy_addrlist,
 984         .from_skb          = sctp_v6_from_skb,
 985         .from_sk           = sctp_v6_from_sk,
 986         .from_addr_param   = sctp_v6_from_addr_param,
 987         .to_addr_param     = sctp_v6_to_addr_param,
 988         .cmp_addr          = sctp_v6_cmp_addr,
 989         .scope             = sctp_v6_scope,
 990         .addr_valid        = sctp_v6_addr_valid,
 991         .inaddr_any        = sctp_v6_inaddr_any,
 992         .is_any            = sctp_v6_is_any,
 993         .available         = sctp_v6_available,
 994         .skb_iif           = sctp_v6_skb_iif,
 995         .is_ce             = sctp_v6_is_ce,
 996         .seq_dump_addr     = sctp_v6_seq_dump_addr,
 997         .ecn_capable       = sctp_v6_ecn_capable,
 998         .net_header_len    = sizeof(struct ipv6hdr),
 999         .sockaddr_len      = sizeof(struct sockaddr_in6),
1000 #ifdef CONFIG_COMPAT
1001         .compat_setsockopt = compat_ipv6_setsockopt,
1002         .compat_getsockopt = compat_ipv6_getsockopt,
1003 #endif
1004 };
1005
1006 static struct sctp_pf sctp_pf_inet6 = {
1007         .event_msgname = sctp_inet6_event_msgname,
1008         .skb_msgname   = sctp_inet6_skb_msgname,
1009         .af_supported  = sctp_inet6_af_supported,
1010         .cmp_addr      = sctp_inet6_cmp_addr,
1011         .bind_verify   = sctp_inet6_bind_verify,
1012         .send_verify   = sctp_inet6_send_verify,
1013         .supported_addrs = sctp_inet6_supported_addrs,
1014         .create_accept_sk = sctp_v6_create_accept_sk,
1015         .addr_to_user  = sctp_v6_addr_to_user,
1016         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1017         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1018         .af            = &sctp_af_inet6,
1019 };
1020
1021 /* Initialize IPv6 support and register with socket layer.  */
1022 void sctp_v6_pf_init(void)
1023 {
1024         /* Register the SCTP specific PF_INET6 functions. */
1025         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1026
1027         /* Register the SCTP specific AF_INET6 functions. */
1028         sctp_register_af(&sctp_af_inet6);
1029 }
1030
1031 void sctp_v6_pf_exit(void)
1032 {
1033         list_del(&sctp_af_inet6.list);
1034 }
1035
1036 /* Initialize IPv6 support and register with socket layer.  */
1037 int sctp_v6_protosw_init(void)
1038 {
1039         int rc;
1040
1041         rc = proto_register(&sctpv6_prot, 1);
1042         if (rc)
1043                 return rc;
1044
1045         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1046         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1047         inet6_register_protosw(&sctpv6_stream_protosw);
1048
1049         return 0;
1050 }
1051
1052 void sctp_v6_protosw_exit(void)
1053 {
1054         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1055         inet6_unregister_protosw(&sctpv6_stream_protosw);
1056         proto_unregister(&sctpv6_prot);
1057 }
1058
1059
1060 /* Register with inet6 layer. */
1061 int sctp_v6_add_protocol(void)
1062 {
1063         /* Register notifier for inet6 address additions/deletions. */
1064         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1065
1066         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1067                 return -EAGAIN;
1068
1069         return 0;
1070 }
1071
1072 /* Unregister with inet6 layer. */
1073 void sctp_v6_del_protocol(void)
1074 {
1075         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1076         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1077 }