net/sctp/ipv6.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2002, 2004
   3  * Copyright (c) 2001 Nokia, Inc.
   4  * Copyright (c) 2001 La Monte H.P. Yarroll
   5  * Copyright (c) 2002-2003 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * This SCTP implementation is free software;
  12  * you can redistribute it and/or modify it under the terms of
  13  * the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This SCTP implementation is distributed in the hope that it
  18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19  *                 ************************
  20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21  * See the GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with GNU CC; see the file COPYING.  If not, see
  25  * <http://www.gnu.org/licenses/>.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    Le Yanqun             <yanqun.le@nokia.com>
  33  *    Hui Huang             <hui.huang@nokia.com>
  34  *    La Monte H.P. Yarroll <piggy@acm.org>
  35  *    Sridhar Samudrala     <sri@us.ibm.com>
  36  *    Jon Grimm             <jgrimm@us.ibm.com>
  37  *    Ardelle Fan           <ardelle.fan@intel.com>
  38  *
  39  * Based on:
  40  *      linux/net/ipv6/tcp_ipv6.c
  41  */
  42
  43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  44
  45 #include <linux/module.h>
  46 #include <linux/errno.h>
  47 #include <linux/types.h>
  48 #include <linux/socket.h>
  49 #include <linux/sockios.h>
  50 #include <linux/net.h>
  51 #include <linux/in.h>
  52 #include <linux/in6.h>
  53 #include <linux/netdevice.h>
  54 #include <linux/init.h>
  55 #include <linux/ipsec.h>
  56 #include <linux/slab.h>
  57
  58 #include <linux/ipv6.h>
  59 #include <linux/icmpv6.h>
  60 #include <linux/random.h>
  61 #include <linux/seq_file.h>
  62
  63 #include <net/protocol.h>
  64 #include <net/ndisc.h>
  65 #include <net/ip.h>
  66 #include <net/ipv6.h>
  67 #include <net/transp_v6.h>
  68 #include <net/addrconf.h>
  69 #include <net/ip6_route.h>
  70 #include <net/inet_common.h>
  71 #include <net/inet_ecn.h>
  72 #include <net/sctp/sctp.h>
  73
  74 #include <linux/uaccess.h>
  75
  76 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  77                                          union sctp_addr *s2);
  78 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  79                               __be16 port);
  80 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  81                             const union sctp_addr *addr2);
  82
  83 /* Event handler for inet6 address addition/deletion events.
  84  * The sctp_local_addr_list needs to be protocted by a spin lock since
  85  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  86  * time and thus corrupt the list.
  87  * The reader side is protected with RCU.
  88  */
  89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  90                                 void *ptr)
  91 {
  92         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  93         struct sctp_sockaddr_entry *addr = NULL;
  94         struct sctp_sockaddr_entry *temp;
  95         struct net *net = dev_net(ifa->idev->dev);
  96         int found = 0;
  97
  98         switch (ev) {
  99         case NETDEV_UP:
 100                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 101                 if (addr) {
 102                         addr->a.v6.sin6_family = AF_INET6;
 103                         addr->a.v6.sin6_port = 0;
 104                         addr->a.v6.sin6_addr = ifa->addr;
 105                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 106                         addr->valid = 1;
 107                         spin_lock_bh(&net->sctp.local_addr_lock);
 108                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 109                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 110                         spin_unlock_bh(&net->sctp.local_addr_lock);
 111                 }
 112                 break;
 113         case NETDEV_DOWN:
 114                 spin_lock_bh(&net->sctp.local_addr_lock);
 115                 list_for_each_entry_safe(addr, temp,
 116                                         &net->sctp.local_addr_list, list) {
 117                         if (addr->a.sa.sa_family == AF_INET6 &&
 118                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 119                                                 &ifa->addr)) {
 120                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 121                                 found = 1;
 122                                 addr->valid = 0;
 123                                 list_del_rcu(&addr->list);
 124                                 break;
 125                         }
 126                 }
 127                 spin_unlock_bh(&net->sctp.local_addr_lock);
 128                 if (found)
 129                         kfree_rcu(addr, rcu);
 130                 break;
 131         }
 132
 133         return NOTIFY_DONE;
 134 }
 135
 136 static struct notifier_block sctp_inet6addr_notifier = {
 137         .notifier_call = sctp_inet6addr_event,
 138 };
 139
 140 /* ICMP error handler. */
 141 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 142                         u8 type, u8 code, int offset, __be32 info)
 143 {
 144         struct inet6_dev *idev;
 145         struct sock *sk;
 146         struct sctp_association *asoc;
 147         struct sctp_transport *transport;
 148         struct ipv6_pinfo *np;
 149         __u16 saveip, savesctp;
 150         int err;
 151         struct net *net = dev_net(skb->dev);
 152
 153         idev = in6_dev_get(skb->dev);
 154
 155         /* Fix up skb to look at the embedded net header. */
 156         saveip   = skb->network_header;
 157         savesctp = skb->transport_header;
 158         skb_reset_network_header(skb);
 159         skb_set_transport_header(skb, offset);
 160         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 161         /* Put back, the original pointers. */
 162         skb->network_header   = saveip;
 163         skb->transport_header = savesctp;
 164         if (!sk) {
 165                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
 166                 goto out;
 167         }
 168
 169         /* Warning:  The sock lock is held.  Remember to call
 170          * sctp_err_finish!
 171          */
 172
 173         switch (type) {
 174         case ICMPV6_PKT_TOOBIG:
 175                 if (ip6_sk_accept_pmtu(sk))
 176                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 177                 goto out_unlock;
 178         case ICMPV6_PARAMPROB:
 179                 if (ICMPV6_UNK_NEXTHDR == code) {
 180                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 181                         goto out_unlock;
 182                 }
 183                 break;
 184         case NDISC_REDIRECT:
 185                 sctp_icmp_redirect(sk, transport, skb);
 186                 goto out_unlock;
 187         default:
 188                 break;
 189         }
 190
 191         np = inet6_sk(sk);
 192         icmpv6_err_convert(type, code, &err);
 193         if (!sock_owned_by_user(sk) && np->recverr) {
 194                 sk->sk_err = err;
 195                 sk->sk_error_report(sk);
 196         } else {  /* Only an error on timeout */
 197                 sk->sk_err_soft = err;
 198         }
 199
 200 out_unlock:
 201         sctp_err_finish(sk, transport);
 202 out:
 203         if (likely(idev != NULL))
 204                 in6_dev_put(idev);
 205 }
 206
 207 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 208 {
 209         struct sock *sk = skb->sk;
 210         struct ipv6_pinfo *np = inet6_sk(sk);
 211         struct flowi6 *fl6 = &transport->fl.u.ip6;
 212         int res;
 213
 214         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 215                  skb->len, &fl6->saddr, &fl6->daddr);
 216
 217         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 218
 219         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 220                 skb->ignore_df = 1;
 221
 222         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 223
 224         rcu_read_lock();
 225         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
 226                        np->tclass);
 227         rcu_read_unlock();
 228         return res;
 229 }
 230
 231 /* Returns the dst cache entry for the given source and destination ip
 232  * addresses.
 233  */
 234 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 235                             struct flowi *fl, struct sock *sk)
 236 {
 237         struct sctp_association *asoc = t->asoc;
 238         struct dst_entry *dst = NULL;
 239         struct flowi6 *fl6 = &fl->u.ip6;
 240         struct sctp_bind_addr *bp;
 241         struct ipv6_pinfo *np = inet6_sk(sk);
 242         struct sctp_sockaddr_entry *laddr;
 243         union sctp_addr *daddr = &t->ipaddr;
 244         union sctp_addr dst_saddr;
 245         struct in6_addr *final_p, final;
 246         __u8 matchlen = 0;
 247         sctp_scope_t scope;
 248
 249         memset(fl6, 0, sizeof(struct flowi6));
 250         fl6->daddr = daddr->v6.sin6_addr;
 251         fl6->fl6_dport = daddr->v6.sin6_port;
 252         fl6->flowi6_proto = IPPROTO_SCTP;
 253         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 254                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 255
 256         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 257
 258         if (asoc)
 259                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 260
 261         if (saddr) {
 262                 fl6->saddr = saddr->v6.sin6_addr;
 263                 fl6->fl6_sport = saddr->v6.sin6_port;
 264
 265                 pr_debug("src=%pI6 - ", &fl6->saddr);
 266         }
 267
 268         rcu_read_lock();
 269         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 270         rcu_read_unlock();
 271
 272         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 273         if (!asoc || saddr)
 274                 goto out;
 275
 276         bp = &asoc->base.bind_addr;
 277         scope = sctp_scope(daddr);
 278         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 279          * to see if we can use it.
 280          */
 281         if (!IS_ERR(dst)) {
 282                 /* Walk through the bind address list and look for a bind
 283                  * address that matches the source address of the returned dst.
 284                  */
 285                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 286                 rcu_read_lock();
 287                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 288                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 289                             (laddr->state != SCTP_ADDR_SRC &&
 290                              !asoc->src_out_of_asoc_ok))
 291                                 continue;
 292
 293                         /* Do not compare against v4 addrs */
 294                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 295                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 296                                 rcu_read_unlock();
 297                                 goto out;
 298                         }
 299                 }
 300                 rcu_read_unlock();
 301                 /* None of the bound addresses match the source address of the
 302                  * dst. So release it.
 303                  */
 304                 dst_release(dst);
 305                 dst = NULL;
 306         }
 307
 308         /* Walk through the bind address list and try to get the
 309          * best source address for a given destination.
 310          */
 311         rcu_read_lock();
 312         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 313                 struct dst_entry *bdst;
 314                 __u8 bmatchlen;
 315
 316                 if (!laddr->valid ||
 317                     laddr->state != SCTP_ADDR_SRC ||
 318                     laddr->a.sa.sa_family != AF_INET6 ||
 319                     scope > sctp_scope(&laddr->a))
 320                         continue;
 321
 322                 fl6->saddr = laddr->a.v6.sin6_addr;
 323                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 324                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 325                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 326
 327                 if (!IS_ERR(bdst) &&
 328                     ipv6_chk_addr(dev_net(bdst->dev),
 329                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 330                         if (!IS_ERR_OR_NULL(dst))
 331                                 dst_release(dst);
 332                         dst = bdst;
 333                         break;
 334                 }
 335
 336                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 337                 if (matchlen > bmatchlen)
 338                         continue;
 339
 340                 if (!IS_ERR_OR_NULL(dst))
 341                         dst_release(dst);
 342                 dst = bdst;
 343                 matchlen = bmatchlen;
 344         }
 345         rcu_read_unlock();
 346
 347 out:
 348         if (!IS_ERR_OR_NULL(dst)) {
 349                 struct rt6_info *rt;
 350
 351                 rt = (struct rt6_info *)dst;
 352                 t->dst = dst;
 353                 t->dst_cookie = rt6_get_cookie(rt);
 354                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 355                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 356                          &fl6->saddr);
 357         } else {
 358                 t->dst = NULL;
 359
 360                 pr_debug("no route\n");
 361         }
 362 }
 363
 364 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 365  * addresses.
 366  */
 367 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 368                                          union sctp_addr *s2)
 369 {
 370         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 371 }
 372
 373 /* Fills in the source address(saddr) based on the destination address(daddr)
 374  * and asoc's bind address list.
 375  */
 376 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 377                               struct sctp_transport *t,
 378                               struct flowi *fl)
 379 {
 380         struct flowi6 *fl6 = &fl->u.ip6;
 381         union sctp_addr *saddr = &t->saddr;
 382
 383         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 384
 385         if (t->dst) {
 386                 saddr->v6.sin6_family = AF_INET6;
 387                 saddr->v6.sin6_addr = fl6->saddr;
 388         }
 389 }
 390
 391 /* Make a copy of all potential local addresses. */
 392 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 393                                   struct net_device *dev)
 394 {
 395         struct inet6_dev *in6_dev;
 396         struct inet6_ifaddr *ifp;
 397         struct sctp_sockaddr_entry *addr;
 398
 399         rcu_read_lock();
 400         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 401                 rcu_read_unlock();
 402                 return;
 403         }
 404
 405         read_lock_bh(&in6_dev->lock);
 406         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 407                 /* Add the address to the local list.  */
 408                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 409                 if (addr) {
 410                         addr->a.v6.sin6_family = AF_INET6;
 411                         addr->a.v6.sin6_port = 0;
 412                         addr->a.v6.sin6_addr = ifp->addr;
 413                         addr->a.v6.sin6_scope_id = dev->ifindex;
 414                         addr->valid = 1;
 415                         INIT_LIST_HEAD(&addr->list);
 416                         list_add_tail(&addr->list, addrlist);
 417                 }
 418         }
 419
 420         read_unlock_bh(&in6_dev->lock);
 421         rcu_read_unlock();
 422 }
 423
 424 /* Initialize a sockaddr_storage from in incoming skb. */
 425 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 426                              int is_saddr)
 427 {
 428         /* Always called on head skb, so this is safe */
 429         struct sctphdr *sh = sctp_hdr(skb);
 430         struct sockaddr_in6 *sa = &addr->v6;
 431
 432         addr->v6.sin6_family = AF_INET6;
 433         addr->v6.sin6_flowinfo = 0; /* FIXME */
 434         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 435
 436         if (is_saddr) {
 437                 sa->sin6_port = sh->source;
 438                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 439         } else {
 440                 sa->sin6_port = sh->dest;
 441                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 442         }
 443 }
 444
 445 /* Initialize an sctp_addr from a socket. */
 446 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 447 {
 448         addr->v6.sin6_family = AF_INET6;
 449         addr->v6.sin6_port = 0;
 450         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 451 }
 452
 453 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 454 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 455 {
 456         if (addr->sa.sa_family == AF_INET) {
 457                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 458                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 459                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 460                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 461                         addr->v4.sin_addr.s_addr;
 462         } else {
 463                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 464         }
 465 }
 466
 467 /* Initialize sk->sk_daddr from sctp_addr. */
 468 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 469 {
 470         if (addr->sa.sa_family == AF_INET) {
 471                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 472                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 473                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 474                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 475         } else {
 476                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 477         }
 478 }
 479
 480 /* Initialize a sctp_addr from an address parameter. */
 481 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 482                                     union sctp_addr_param *param,
 483                                     __be16 port, int iif)
 484 {
 485         addr->v6.sin6_family = AF_INET6;
 486         addr->v6.sin6_port = port;
 487         addr->v6.sin6_flowinfo = 0; /* BUG */
 488         addr->v6.sin6_addr = param->v6.addr;
 489         addr->v6.sin6_scope_id = iif;
 490 }
 491
 492 /* Initialize an address parameter from a sctp_addr and return the length
 493  * of the address parameter.
 494  */
 495 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 496                                  union sctp_addr_param *param)
 497 {
 498         int length = sizeof(sctp_ipv6addr_param_t);
 499
 500         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 501         param->v6.param_hdr.length = htons(length);
 502         param->v6.addr = addr->v6.sin6_addr;
 503
 504         return length;
 505 }
 506
 507 /* Initialize a sctp_addr from struct in6_addr. */
 508 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 509                               __be16 port)
 510 {
 511         addr->sa.sa_family = AF_INET6;
 512         addr->v6.sin6_port = port;
 513         addr->v6.sin6_addr = *saddr;
 514 }
 515
 516 /* Compare addresses exactly.
 517  * v4-mapped-v6 is also in consideration.
 518  */
 519 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 520                             const union sctp_addr *addr2)
 521 {
 522         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 523                 if (addr1->sa.sa_family == AF_INET &&
 524                     addr2->sa.sa_family == AF_INET6 &&
 525                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 526                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 527                             addr2->v6.sin6_addr.s6_addr32[3] ==
 528                             addr1->v4.sin_addr.s_addr)
 529                                 return 1;
 530                 }
 531                 if (addr2->sa.sa_family == AF_INET &&
 532                     addr1->sa.sa_family == AF_INET6 &&
 533                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 534                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 535                             addr1->v6.sin6_addr.s6_addr32[3] ==
 536                             addr2->v4.sin_addr.s_addr)
 537                                 return 1;
 538                 }
 539                 return 0;
 540         }
 541         if (addr1->v6.sin6_port != addr2->v6.sin6_port)
 542                 return 0;
 543         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 544                 return 0;
 545         /* If this is a linklocal address, compare the scope_id. */
 546         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 547                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 548                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 549                         return 0;
 550                 }
 551         }
 552
 553         return 1;
 554 }
 555
 556 /* Initialize addr struct to INADDR_ANY. */
 557 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 558 {
 559         memset(addr, 0x00, sizeof(union sctp_addr));
 560         addr->v6.sin6_family = AF_INET6;
 561         addr->v6.sin6_port = port;
 562 }
 563
 564 /* Is this a wildcard address? */
 565 static int sctp_v6_is_any(const union sctp_addr *addr)
 566 {
 567         return ipv6_addr_any(&addr->v6.sin6_addr);
 568 }
 569
 570 /* Should this be available for binding?   */
 571 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 572 {
 573         int type;
 574         struct net *net = sock_net(&sp->inet.sk);
 575         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 576
 577         type = ipv6_addr_type(in6);
 578         if (IPV6_ADDR_ANY == type)
 579                 return 1;
 580         if (type == IPV6_ADDR_MAPPED) {
 581                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 582                         return 0;
 583                 sctp_v6_map_v4(addr);
 584                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 585         }
 586         if (!(type & IPV6_ADDR_UNICAST))
 587                 return 0;
 588
 589         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 590                 ipv6_chk_addr(net, in6, NULL, 0);
 591 }
 592
 593 /* This function checks if the address is a valid address to be used for
 594  * SCTP.
 595  *
 596  * Output:
 597  * Return 0 - If the address is a non-unicast or an illegal address.
 598  * Return 1 - If the address is a unicast.
 599  */
 600 static int sctp_v6_addr_valid(union sctp_addr *addr,
 601                               struct sctp_sock *sp,
 602                               const struct sk_buff *skb)
 603 {
 604         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 605
 606         /* Support v4-mapped-v6 address. */
 607         if (ret == IPV6_ADDR_MAPPED) {
 608                 /* Note: This routine is used in input, so v4-mapped-v6
 609                  * are disallowed here when there is no sctp_sock.
 610                  */
 611                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 612                         return 0;
 613                 sctp_v6_map_v4(addr);
 614                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 615         }
 616
 617         /* Is this a non-unicast address */
 618         if (!(ret & IPV6_ADDR_UNICAST))
 619                 return 0;
 620
 621         return 1;
 622 }
 623
 624 /* What is the scope of 'addr'?  */
 625 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 626 {
 627         int v6scope;
 628         sctp_scope_t retval;
 629
 630         /* The IPv6 scope is really a set of bit fields.
 631          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 632          */
 633
 634         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 635         switch (v6scope) {
 636         case IFA_HOST:
 637                 retval = SCTP_SCOPE_LOOPBACK;
 638                 break;
 639         case IFA_LINK:
 640                 retval = SCTP_SCOPE_LINK;
 641                 break;
 642         case IFA_SITE:
 643                 retval = SCTP_SCOPE_PRIVATE;
 644                 break;
 645         default:
 646                 retval = SCTP_SCOPE_GLOBAL;
 647                 break;
 648         }
 649
 650         return retval;
 651 }
 652
 653 /* Create and initialize a new sk for the socket to be returned by accept(). */
 654 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 655                                              struct sctp_association *asoc,
 656                                              bool kern)
 657 {
 658         struct sock *newsk;
 659         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 660         struct sctp6_sock *newsctp6sk;
 661         struct ipv6_txoptions *opt;
 662
 663         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 664         if (!newsk)
 665                 goto out;
 666
 667         sock_init_data(NULL, newsk);
 668
 669         sctp_copy_sock(newsk, sk, asoc);
 670         sock_reset_flag(sk, SOCK_ZAPPED);
 671
 672         newsctp6sk = (struct sctp6_sock *)newsk;
 673         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 674
 675         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 676
 677         newnp = inet6_sk(newsk);
 678
 679         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 680         newnp->ipv6_mc_list = NULL;
 681         newnp->ipv6_ac_list = NULL;
 682         newnp->ipv6_fl_list = NULL;
 683
 684         rcu_read_lock();
 685         opt = rcu_dereference(np->opt);
 686         if (opt)
 687                 opt = ipv6_dup_options(newsk, opt);
 688         RCU_INIT_POINTER(newnp->opt, opt);
 689         rcu_read_unlock();
 690
 691         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 692          * and getpeername().
 693          */
 694         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 695
 696         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 697
 698         sk_refcnt_debug_inc(newsk);
 699
 700         if (newsk->sk_prot->init(newsk)) {
 701                 sk_common_release(newsk);
 702                 newsk = NULL;
 703         }
 704
 705 out:
 706         return newsk;
 707 }
 708
 709 /* Format a sockaddr for return to user space. This makes sure the return is
 710  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 711  */
 712 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 713 {
 714         if (sp->v4mapped) {
 715                 if (addr->sa.sa_family == AF_INET)
 716                         sctp_v4_map_v6(addr);
 717         } else {
 718                 if (addr->sa.sa_family == AF_INET6 &&
 719                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 720                         sctp_v6_map_v4(addr);
 721         }
 722
 723         if (addr->sa.sa_family == AF_INET)
 724                 return sizeof(struct sockaddr_in);
 725         return sizeof(struct sockaddr_in6);
 726 }
 727
 728 /* Where did this skb come from?  */
 729 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 730 {
 731         return IP6CB(skb)->iif;
 732 }
 733
 734 /* Was this packet marked by Explicit Congestion Notification? */
 735 static int sctp_v6_is_ce(const struct sk_buff *skb)
 736 {
 737         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 738 }
 739
 740 /* Dump the v6 addr to the seq file. */
 741 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 742 {
 743         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 744 }
 745
 746 static void sctp_v6_ecn_capable(struct sock *sk)
 747 {
 748         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 749 }
 750
 751 /* Initialize a PF_INET msgname from a ulpevent. */
 752 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 753                                      char *msgname, int *addrlen)
 754 {
 755         union sctp_addr *addr;
 756         struct sctp_association *asoc;
 757         union sctp_addr *paddr;
 758
 759         if (!msgname)
 760                 return;
 761
 762         addr = (union sctp_addr *)msgname;
 763         asoc = event->asoc;
 764         paddr = &asoc->peer.primary_addr;
 765
 766         if (paddr->sa.sa_family == AF_INET) {
 767                 addr->v4.sin_family = AF_INET;
 768                 addr->v4.sin_port = htons(asoc->peer.port);
 769                 addr->v4.sin_addr = paddr->v4.sin_addr;
 770         } else {
 771                 addr->v6.sin6_family = AF_INET6;
 772                 addr->v6.sin6_flowinfo = 0;
 773                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 774                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 775                 else
 776                         addr->v6.sin6_scope_id = 0;
 777                 addr->v6.sin6_port = htons(asoc->peer.port);
 778                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 779         }
 780
 781         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 782 }
 783
 784 /* Initialize a msg_name from an inbound skb. */
 785 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 786                                    int *addr_len)
 787 {
 788         union sctp_addr *addr;
 789         struct sctphdr *sh;
 790
 791         if (!msgname)
 792                 return;
 793
 794         addr = (union sctp_addr *)msgname;
 795         sh = sctp_hdr(skb);
 796
 797         if (ip_hdr(skb)->version == 4) {
 798                 addr->v4.sin_family = AF_INET;
 799                 addr->v4.sin_port = sh->source;
 800                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 801         } else {
 802                 addr->v6.sin6_family = AF_INET6;
 803                 addr->v6.sin6_flowinfo = 0;
 804                 addr->v6.sin6_port = sh->source;
 805                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 806                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 807                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 808                 }
 809         }
 810
 811         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 812 }
 813
 814 /* Do we support this AF? */
 815 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 816 {
 817         switch (family) {
 818         case AF_INET6:
 819                 return 1;
 820         /* v4-mapped-v6 addresses */
 821         case AF_INET:
 822                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 823                         return 1;
 824         default:
 825                 return 0;
 826         }
 827 }
 828
 829 /* Address matching with wildcards allowed.  This extra level
 830  * of indirection lets us choose whether a PF_INET6 should
 831  * disallow any v4 addresses if we so choose.
 832  */
 833 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 834                                const union sctp_addr *addr2,
 835                                struct sctp_sock *opt)
 836 {
 837         struct sctp_af *af1, *af2;
 838         struct sock *sk = sctp_opt2sk(opt);
 839
 840         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 841         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 842
 843         if (!af1 || !af2)
 844                 return 0;
 845
 846         /* If the socket is IPv6 only, v4 addrs will not match */
 847         if (__ipv6_only_sock(sk) && af1 != af2)
 848                 return 0;
 849
 850         /* Today, wildcard AF_INET/AF_INET6. */
 851         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 852                 return 1;
 853
 854         if (addr1->sa.sa_family != addr2->sa.sa_family)
 855                 return 0;
 856
 857         return af1->cmp_addr(addr1, addr2);
 858 }
 859
 860 /* Verify that the provided sockaddr looks bindable.   Common verification,
 861  * has already been taken care of.
 862  */
 863 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 864 {
 865         struct sctp_af *af;
 866
 867         /* ASSERT: address family has already been verified. */
 868         if (addr->sa.sa_family != AF_INET6)
 869                 af = sctp_get_af_specific(addr->sa.sa_family);
 870         else {
 871                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 872                 struct net_device *dev;
 873
 874                 if (type & IPV6_ADDR_LINKLOCAL) {
 875                         struct net *net;
 876                         if (!addr->v6.sin6_scope_id)
 877                                 return 0;
 878                         net = sock_net(&opt->inet.sk);
 879                         rcu_read_lock();
 880                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 881                         if (!dev ||
 882                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 883                                 rcu_read_unlock();
 884                                 return 0;
 885                         }
 886                         rcu_read_unlock();
 887                 }
 888
 889                 af = opt->pf->af;
 890         }
 891         return af->available(addr, opt);
 892 }
 893
 894 /* Verify that the provided sockaddr looks sendable.   Common verification,
 895  * has already been taken care of.
 896  */
 897 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 898 {
 899         struct sctp_af *af = NULL;
 900
 901         /* ASSERT: address family has already been verified. */
 902         if (addr->sa.sa_family != AF_INET6)
 903                 af = sctp_get_af_specific(addr->sa.sa_family);
 904         else {
 905                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 906                 struct net_device *dev;
 907
 908                 if (type & IPV6_ADDR_LINKLOCAL) {
 909                         if (!addr->v6.sin6_scope_id)
 910                                 return 0;
 911                         rcu_read_lock();
 912                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 913                                                    addr->v6.sin6_scope_id);
 914                         rcu_read_unlock();
 915                         if (!dev)
 916                                 return 0;
 917                 }
 918                 af = opt->pf->af;
 919         }
 920
 921         return af != NULL;
 922 }
 923
 924 /* Fill in Supported Address Type information for INIT and INIT-ACK
 925  * chunks.   Note: In the future, we may want to look at sock options
 926  * to determine whether a PF_INET6 socket really wants to have IPV4
 927  * addresses.
 928  * Returns number of addresses supported.
 929  */
 930 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 931                                       __be16 *types)
 932 {
 933         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 934         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 935                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 936                 return 2;
 937         }
 938         return 1;
 939 }
 940
 941 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 942 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 943                         int *uaddr_len, int peer)
 944 {
 945         int rc;
 946
 947         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 948
 949         if (rc != 0)
 950                 return rc;
 951
 952         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 953                                           (union sctp_addr *)uaddr);
 954
 955         return rc;
 956 }
 957
 958 static const struct proto_ops inet6_seqpacket_ops = {
 959         .family            = PF_INET6,
 960         .owner             = THIS_MODULE,
 961         .release           = inet6_release,
 962         .bind              = inet6_bind,
 963         .connect           = inet_dgram_connect,
 964         .socketpair        = sock_no_socketpair,
 965         .accept            = inet_accept,
 966         .getname           = sctp_getname,
 967         .poll              = sctp_poll,
 968         .ioctl             = inet6_ioctl,
 969         .listen            = sctp_inet_listen,
 970         .shutdown          = inet_shutdown,
 971         .setsockopt        = sock_common_setsockopt,
 972         .getsockopt        = sock_common_getsockopt,
 973         .sendmsg           = inet_sendmsg,
 974         .recvmsg           = inet_recvmsg,
 975         .mmap              = sock_no_mmap,
 976 #ifdef CONFIG_COMPAT
 977         .compat_setsockopt = compat_sock_common_setsockopt,
 978         .compat_getsockopt = compat_sock_common_getsockopt,
 979 #endif
 980 };
 981
 982 static struct inet_protosw sctpv6_seqpacket_protosw = {
 983         .type          = SOCK_SEQPACKET,
 984         .protocol      = IPPROTO_SCTP,
 985         .prot          = &sctpv6_prot,
 986         .ops           = &inet6_seqpacket_ops,
 987         .flags         = SCTP_PROTOSW_FLAG
 988 };
 989 static struct inet_protosw sctpv6_stream_protosw = {
 990         .type          = SOCK_STREAM,
 991         .protocol      = IPPROTO_SCTP,
 992         .prot          = &sctpv6_prot,
 993         .ops           = &inet6_seqpacket_ops,
 994         .flags         = SCTP_PROTOSW_FLAG,
 995 };
 996
 997 static int sctp6_rcv(struct sk_buff *skb)
 998 {
 999         return sctp_rcv(skb) ? -1 : 0;
1000 }
1001
1002 static const struct inet6_protocol sctpv6_protocol = {
1003         .handler      = sctp6_rcv,
1004         .err_handler  = sctp_v6_err,
1005         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1006 };
1007
1008 static struct sctp_af sctp_af_inet6 = {
1009         .sa_family         = AF_INET6,
1010         .sctp_xmit         = sctp_v6_xmit,
1011         .setsockopt        = ipv6_setsockopt,
1012         .getsockopt        = ipv6_getsockopt,
1013         .get_dst           = sctp_v6_get_dst,
1014         .get_saddr         = sctp_v6_get_saddr,
1015         .copy_addrlist     = sctp_v6_copy_addrlist,
1016         .from_skb          = sctp_v6_from_skb,
1017         .from_sk           = sctp_v6_from_sk,
1018         .from_addr_param   = sctp_v6_from_addr_param,
1019         .to_addr_param     = sctp_v6_to_addr_param,
1020         .cmp_addr          = sctp_v6_cmp_addr,
1021         .scope             = sctp_v6_scope,
1022         .addr_valid        = sctp_v6_addr_valid,
1023         .inaddr_any        = sctp_v6_inaddr_any,
1024         .is_any            = sctp_v6_is_any,
1025         .available         = sctp_v6_available,
1026         .skb_iif           = sctp_v6_skb_iif,
1027         .is_ce             = sctp_v6_is_ce,
1028         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1029         .ecn_capable       = sctp_v6_ecn_capable,
1030         .net_header_len    = sizeof(struct ipv6hdr),
1031         .sockaddr_len      = sizeof(struct sockaddr_in6),
1032 #ifdef CONFIG_COMPAT
1033         .compat_setsockopt = compat_ipv6_setsockopt,
1034         .compat_getsockopt = compat_ipv6_getsockopt,
1035 #endif
1036 };
1037
1038 static struct sctp_pf sctp_pf_inet6 = {
1039         .event_msgname = sctp_inet6_event_msgname,
1040         .skb_msgname   = sctp_inet6_skb_msgname,
1041         .af_supported  = sctp_inet6_af_supported,
1042         .cmp_addr      = sctp_inet6_cmp_addr,
1043         .bind_verify   = sctp_inet6_bind_verify,
1044         .send_verify   = sctp_inet6_send_verify,
1045         .supported_addrs = sctp_inet6_supported_addrs,
1046         .create_accept_sk = sctp_v6_create_accept_sk,
1047         .addr_to_user  = sctp_v6_addr_to_user,
1048         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1049         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1050         .af            = &sctp_af_inet6,
1051 };
1052
1053 /* Initialize IPv6 support and register with socket layer.  */
1054 void sctp_v6_pf_init(void)
1055 {
1056         /* Register the SCTP specific PF_INET6 functions. */
1057         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1058
1059         /* Register the SCTP specific AF_INET6 functions. */
1060         sctp_register_af(&sctp_af_inet6);
1061 }
1062
1063 void sctp_v6_pf_exit(void)
1064 {
1065         list_del(&sctp_af_inet6.list);
1066 }
1067
1068 /* Initialize IPv6 support and register with socket layer.  */
1069 int sctp_v6_protosw_init(void)
1070 {
1071         int rc;
1072
1073         rc = proto_register(&sctpv6_prot, 1);
1074         if (rc)
1075                 return rc;
1076
1077         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1078         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1079         inet6_register_protosw(&sctpv6_stream_protosw);
1080
1081         return 0;
1082 }
1083
1084 void sctp_v6_protosw_exit(void)
1085 {
1086         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1087         inet6_unregister_protosw(&sctpv6_stream_protosw);
1088         proto_unregister(&sctpv6_prot);
1089 }
1090
1091
1092 /* Register with inet6 layer. */
1093 int sctp_v6_add_protocol(void)
1094 {
1095         /* Register notifier for inet6 address additions/deletions. */
1096         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1097
1098         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1099                 return -EAGAIN;
1100
1101         return 0;
1102 }
1103
1104 /* Unregister with inet6 layer. */
1105 void sctp_v6_del_protocol(void)
1106 {
1107         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1108         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1109 }