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   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, write to
  25  * the Free Software Foundation, 59 Temple Place - Suite 330,
  26  * Boston, MA 02111-1307, USA.
  27  *
  28  * Please send any bug reports or fixes you make to the
  29  * email address(es):
  30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  31  *
  32  * Or submit a bug report through the following website:
  33  *    http://www.sf.net/projects/lksctp
  34  *
  35  * Written or modified by:
  36  *    Le Yanqun             <yanqun.le@nokia.com>
  37  *    Hui Huang             <hui.huang@nokia.com>
  38  *    La Monte H.P. Yarroll <piggy@acm.org>
  39  *    Sridhar Samudrala     <sri@us.ibm.com>
  40  *    Jon Grimm             <jgrimm@us.ibm.com>
  41  *    Ardelle Fan           <ardelle.fan@intel.com>
  42  *
  43  * Based on:
  44  *      linux/net/ipv6/tcp_ipv6.c
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/module.h>
  51 #include <linux/errno.h>
  52 #include <linux/types.h>
  53 #include <linux/socket.h>
  54 #include <linux/sockios.h>
  55 #include <linux/net.h>
  56 #include <linux/in.h>
  57 #include <linux/in6.h>
  58 #include <linux/netdevice.h>
  59 #include <linux/init.h>
  60 #include <linux/ipsec.h>
  61
  62 #include <linux/ipv6.h>
  63 #include <linux/icmpv6.h>
  64 #include <linux/random.h>
  65 #include <linux/seq_file.h>
  66
  67 #include <net/protocol.h>
  68 #include <net/ndisc.h>
  69 #include <net/ip.h>
  70 #include <net/ipv6.h>
  71 #include <net/transp_v6.h>
  72 #include <net/addrconf.h>
  73 #include <net/ip6_route.h>
  74 #include <net/inet_common.h>
  75 #include <net/inet_ecn.h>
  76 #include <net/sctp/sctp.h>
  77
  78 #include <asm/uaccess.h>
  79
  80 /* Event handler for inet6 address addition/deletion events.
  81  * The sctp_local_addr_list needs to be protocted by a spin lock since
  82  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  83  * time and thus corrupt the list.
  84  * The reader side is protected with RCU.
  85  */
  86 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  87                                 void *ptr)
  88 {
  89         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  90         struct sctp_sockaddr_entry *addr = NULL;
  91         struct sctp_sockaddr_entry *temp;
  92
  93         switch (ev) {
  94         case NETDEV_UP:
  95                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  96                 if (addr) {
  97                         addr->a.v6.sin6_family = AF_INET6;
  98                         addr->a.v6.sin6_port = 0;
  99                         memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
 100                                  sizeof(struct in6_addr));
 101                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 102                         addr->valid = 1;
 103                         spin_lock_bh(&sctp_local_addr_lock);
 104                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
 105                         spin_unlock_bh(&sctp_local_addr_lock);
 106                 }
 107                 break;
 108         case NETDEV_DOWN:
 109                 spin_lock_bh(&sctp_local_addr_lock);
 110                 list_for_each_entry_safe(addr, temp,
 111                                         &sctp_local_addr_list, list) {
 112                         if (ipv6_addr_equal(&addr->a.v6.sin6_addr,
 113                                              &ifa->addr)) {
 114                                 addr->valid = 0;
 115                                 list_del_rcu(&addr->list);
 116                                 break;
 117                         }
 118                 }
 119                 spin_unlock_bh(&sctp_local_addr_lock);
 120                 if (addr && !addr->valid)
 121                         call_rcu(&addr->rcu, sctp_local_addr_free);
 122                 break;
 123         }
 124
 125         return NOTIFY_DONE;
 126 }
 127
 128 static struct notifier_block sctp_inet6addr_notifier = {
 129         .notifier_call = sctp_inet6addr_event,
 130 };
 131
 132 /* ICMP error handler. */
 133 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 134                              int type, int code, int offset, __be32 info)
 135 {
 136         struct inet6_dev *idev;
 137         struct sock *sk;
 138         struct sctp_association *asoc;
 139         struct sctp_transport *transport;
 140         struct ipv6_pinfo *np;
 141         sk_buff_data_t saveip, savesctp;
 142         int err;
 143
 144         idev = in6_dev_get(skb->dev);
 145
 146         /* Fix up skb to look at the embedded net header. */
 147         saveip   = skb->network_header;
 148         savesctp = skb->transport_header;
 149         skb_reset_network_header(skb);
 150         skb_set_transport_header(skb, offset);
 151         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 152         /* Put back, the original pointers. */
 153         skb->network_header   = saveip;
 154         skb->transport_header = savesctp;
 155         if (!sk) {
 156                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 157                 goto out;
 158         }
 159
 160         /* Warning:  The sock lock is held.  Remember to call
 161          * sctp_err_finish!
 162          */
 163
 164         switch (type) {
 165         case ICMPV6_PKT_TOOBIG:
 166                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 167                 goto out_unlock;
 168         case ICMPV6_PARAMPROB:
 169                 if (ICMPV6_UNK_NEXTHDR == code) {
 170                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 171                         goto out_unlock;
 172                 }
 173                 break;
 174         default:
 175                 break;
 176         }
 177
 178         np = inet6_sk(sk);
 179         icmpv6_err_convert(type, code, &err);
 180         if (!sock_owned_by_user(sk) && np->recverr) {
 181                 sk->sk_err = err;
 182                 sk->sk_error_report(sk);
 183         } else {  /* Only an error on timeout */
 184                 sk->sk_err_soft = err;
 185         }
 186
 187 out_unlock:
 188         sctp_err_finish(sk, asoc);
 189 out:
 190         if (likely(idev != NULL))
 191                 in6_dev_put(idev);
 192 }
 193
 194 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 195 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
 196                         int ipfragok)
 197 {
 198         struct sock *sk = skb->sk;
 199         struct ipv6_pinfo *np = inet6_sk(sk);
 200         struct flowi fl;
 201
 202         memset(&fl, 0, sizeof(fl));
 203
 204         fl.proto = sk->sk_protocol;
 205
 206         /* Fill in the dest address from the route entry passed with the skb
 207          * and the source address from the transport.
 208          */
 209         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 210         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 211
 212         fl.fl6_flowlabel = np->flow_label;
 213         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 214         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 215                 fl.oif = transport->saddr.v6.sin6_scope_id;
 216         else
 217                 fl.oif = sk->sk_bound_dev_if;
 218
 219         if (np->opt && np->opt->srcrt) {
 220                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 221                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 222         }
 223
 224         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
 225                           "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
 226                           __FUNCTION__, skb, skb->len,
 227                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
 228
 229         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 230
 231         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
 232 }
 233
 234 /* Returns the dst cache entry for the given source and destination ip
 235  * addresses.
 236  */
 237 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 238                                          union sctp_addr *daddr,
 239                                          union sctp_addr *saddr)
 240 {
 241         struct dst_entry *dst;
 242         struct flowi fl;
 243
 244         memset(&fl, 0, sizeof(fl));
 245         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 246         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 247                 fl.oif = daddr->v6.sin6_scope_id;
 248
 249
 250         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
 251                           __FUNCTION__, NIP6(fl.fl6_dst));
 252
 253         if (saddr) {
 254                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 255                 SCTP_DEBUG_PRINTK(
 256                         "SRC=" NIP6_FMT " - ",
 257                         NIP6(fl.fl6_src));
 258         }
 259
 260         dst = ip6_route_output(&init_net, NULL, &fl);
 261         if (!dst->error) {
 262                 struct rt6_info *rt;
 263                 rt = (struct rt6_info *)dst;
 264                 SCTP_DEBUG_PRINTK(
 265                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
 266                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
 267                 return dst;
 268         }
 269         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 270         dst_release(dst);
 271         return NULL;
 272 }
 273
 274 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 275  * addresses.
 276  */
 277 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 278                                          union sctp_addr *s2)
 279 {
 280         struct in6_addr *a1 = &s1->v6.sin6_addr;
 281         struct in6_addr *a2 = &s2->v6.sin6_addr;
 282         int i, j;
 283
 284         for (i = 0; i < 4 ; i++) {
 285                 __be32 a1xora2;
 286
 287                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 288
 289                 if ((j = fls(ntohl(a1xora2))))
 290                         return (i * 32 + 32 - j);
 291         }
 292
 293         return (i*32);
 294 }
 295
 296 /* Fills in the source address(saddr) based on the destination address(daddr)
 297  * and asoc's bind address list.
 298  */
 299 static void sctp_v6_get_saddr(struct sctp_association *asoc,
 300                               struct dst_entry *dst,
 301                               union sctp_addr *daddr,
 302                               union sctp_addr *saddr)
 303 {
 304         struct sctp_bind_addr *bp;
 305         struct sctp_sockaddr_entry *laddr;
 306         sctp_scope_t scope;
 307         union sctp_addr *baddr = NULL;
 308         __u8 matchlen = 0;
 309         __u8 bmatchlen;
 310
 311         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
 312                           "daddr:" NIP6_FMT " ",
 313                           __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
 314
 315         if (!asoc) {
 316                 ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL,
 317                                    &daddr->v6.sin6_addr, &saddr->v6.sin6_addr);
 318                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
 319                                   NIP6(saddr->v6.sin6_addr));
 320                 return;
 321         }
 322
 323         scope = sctp_scope(daddr);
 324
 325         bp = &asoc->base.bind_addr;
 326
 327         /* Go through the bind address list and find the best source address
 328          * that matches the scope of the destination address.
 329          */
 330         rcu_read_lock();
 331         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 332                 if (!laddr->valid)
 333                         continue;
 334                 if ((laddr->state == SCTP_ADDR_SRC) &&
 335                     (laddr->a.sa.sa_family == AF_INET6) &&
 336                     (scope <= sctp_scope(&laddr->a))) {
 337                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 338                         if (!baddr || (matchlen < bmatchlen)) {
 339                                 baddr = &laddr->a;
 340                                 matchlen = bmatchlen;
 341                         }
 342                 }
 343         }
 344
 345         if (baddr) {
 346                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 347                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
 348                                   NIP6(saddr->v6.sin6_addr));
 349         } else {
 350                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 351                        "address for the dest:" NIP6_FMT "\n",
 352                        __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
 353         }
 354
 355         rcu_read_unlock();
 356 }
 357
 358 /* Make a copy of all potential local addresses. */
 359 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 360                                   struct net_device *dev)
 361 {
 362         struct inet6_dev *in6_dev;
 363         struct inet6_ifaddr *ifp;
 364         struct sctp_sockaddr_entry *addr;
 365
 366         rcu_read_lock();
 367         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 368                 rcu_read_unlock();
 369                 return;
 370         }
 371
 372         read_lock_bh(&in6_dev->lock);
 373         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 374                 /* Add the address to the local list.  */
 375                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 376                 if (addr) {
 377                         addr->a.v6.sin6_family = AF_INET6;
 378                         addr->a.v6.sin6_port = 0;
 379                         addr->a.v6.sin6_addr = ifp->addr;
 380                         addr->a.v6.sin6_scope_id = dev->ifindex;
 381                         addr->valid = 1;
 382                         INIT_LIST_HEAD(&addr->list);
 383                         INIT_RCU_HEAD(&addr->rcu);
 384                         list_add_tail(&addr->list, addrlist);
 385                 }
 386         }
 387
 388         read_unlock_bh(&in6_dev->lock);
 389         rcu_read_unlock();
 390 }
 391
 392 /* Initialize a sockaddr_storage from in incoming skb. */
 393 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 394                              int is_saddr)
 395 {
 396         void *from;
 397         __be16 *port;
 398         struct sctphdr *sh;
 399
 400         port = &addr->v6.sin6_port;
 401         addr->v6.sin6_family = AF_INET6;
 402         addr->v6.sin6_flowinfo = 0; /* FIXME */
 403         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 404
 405         sh = sctp_hdr(skb);
 406         if (is_saddr) {
 407                 *port  = sh->source;
 408                 from = &ipv6_hdr(skb)->saddr;
 409         } else {
 410                 *port = sh->dest;
 411                 from = &ipv6_hdr(skb)->daddr;
 412         }
 413         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 414 }
 415
 416 /* Initialize an sctp_addr from a socket. */
 417 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 418 {
 419         addr->v6.sin6_family = AF_INET6;
 420         addr->v6.sin6_port = 0;
 421         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 422 }
 423
 424 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 425 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 426 {
 427         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 428                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 429                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 430                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 431                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 432                         addr->v4.sin_addr.s_addr;
 433         } else {
 434                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 435         }
 436 }
 437
 438 /* Initialize sk->sk_daddr from sctp_addr. */
 439 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 440 {
 441         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 442                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 443                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 444                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 445                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 446         } else {
 447                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 448         }
 449 }
 450
 451 /* Initialize a sctp_addr from an address parameter. */
 452 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 453                                     union sctp_addr_param *param,
 454                                     __be16 port, int iif)
 455 {
 456         addr->v6.sin6_family = AF_INET6;
 457         addr->v6.sin6_port = port;
 458         addr->v6.sin6_flowinfo = 0; /* BUG */
 459         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 460         addr->v6.sin6_scope_id = iif;
 461 }
 462
 463 /* Initialize an address parameter from a sctp_addr and return the length
 464  * of the address parameter.
 465  */
 466 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 467                                  union sctp_addr_param *param)
 468 {
 469         int length = sizeof(sctp_ipv6addr_param_t);
 470
 471         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 472         param->v6.param_hdr.length = htons(length);
 473         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 474
 475         return length;
 476 }
 477
 478 /* Initialize a sctp_addr from a dst_entry. */
 479 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 480                               __be16 port)
 481 {
 482         struct rt6_info *rt = (struct rt6_info *)dst;
 483         addr->sa.sa_family = AF_INET6;
 484         addr->v6.sin6_port = port;
 485         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 486 }
 487
 488 /* Compare addresses exactly.
 489  * v4-mapped-v6 is also in consideration.
 490  */
 491 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 492                             const union sctp_addr *addr2)
 493 {
 494         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 495                 if (addr1->sa.sa_family == AF_INET &&
 496                     addr2->sa.sa_family == AF_INET6 &&
 497                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 498                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 499                             addr2->v6.sin6_addr.s6_addr32[3] ==
 500                             addr1->v4.sin_addr.s_addr)
 501                                 return 1;
 502                 }
 503                 if (addr2->sa.sa_family == AF_INET &&
 504                     addr1->sa.sa_family == AF_INET6 &&
 505                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 506                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 507                             addr1->v6.sin6_addr.s6_addr32[3] ==
 508                             addr2->v4.sin_addr.s_addr)
 509                                 return 1;
 510                 }
 511                 return 0;
 512         }
 513         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 514                 return 0;
 515         /* If this is a linklocal address, compare the scope_id. */
 516         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 517                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 518                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 519                         return 0;
 520                 }
 521         }
 522
 523         return 1;
 524 }
 525
 526 /* Initialize addr struct to INADDR_ANY. */
 527 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 528 {
 529         memset(addr, 0x00, sizeof(union sctp_addr));
 530         addr->v6.sin6_family = AF_INET6;
 531         addr->v6.sin6_port = port;
 532 }
 533
 534 /* Is this a wildcard address? */
 535 static int sctp_v6_is_any(const union sctp_addr *addr)
 536 {
 537         return ipv6_addr_any(&addr->v6.sin6_addr);
 538 }
 539
 540 /* Should this be available for binding?   */
 541 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 542 {
 543         int type;
 544         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 545
 546         type = ipv6_addr_type(in6);
 547         if (IPV6_ADDR_ANY == type)
 548                 return 1;
 549         if (type == IPV6_ADDR_MAPPED) {
 550                 if (sp && !sp->v4mapped)
 551                         return 0;
 552                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 553                         return 0;
 554                 sctp_v6_map_v4(addr);
 555                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 556         }
 557         if (!(type & IPV6_ADDR_UNICAST))
 558                 return 0;
 559
 560         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 561 }
 562
 563 /* This function checks if the address is a valid address to be used for
 564  * SCTP.
 565  *
 566  * Output:
 567  * Return 0 - If the address is a non-unicast or an illegal address.
 568  * Return 1 - If the address is a unicast.
 569  */
 570 static int sctp_v6_addr_valid(union sctp_addr *addr,
 571                               struct sctp_sock *sp,
 572                               const struct sk_buff *skb)
 573 {
 574         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 575
 576         /* Support v4-mapped-v6 address. */
 577         if (ret == IPV6_ADDR_MAPPED) {
 578                 /* Note: This routine is used in input, so v4-mapped-v6
 579                  * are disallowed here when there is no sctp_sock.
 580                  */
 581                 if (!sp || !sp->v4mapped)
 582                         return 0;
 583                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 584                         return 0;
 585                 sctp_v6_map_v4(addr);
 586                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 587         }
 588
 589         /* Is this a non-unicast address */
 590         if (!(ret & IPV6_ADDR_UNICAST))
 591                 return 0;
 592
 593         return 1;
 594 }
 595
 596 /* What is the scope of 'addr'?  */
 597 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 598 {
 599         int v6scope;
 600         sctp_scope_t retval;
 601
 602         /* The IPv6 scope is really a set of bit fields.
 603          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 604          */
 605
 606         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 607         switch (v6scope) {
 608         case IFA_HOST:
 609                 retval = SCTP_SCOPE_LOOPBACK;
 610                 break;
 611         case IFA_LINK:
 612                 retval = SCTP_SCOPE_LINK;
 613                 break;
 614         case IFA_SITE:
 615                 retval = SCTP_SCOPE_PRIVATE;
 616                 break;
 617         default:
 618                 retval = SCTP_SCOPE_GLOBAL;
 619                 break;
 620         }
 621
 622         return retval;
 623 }
 624
 625 /* Create and initialize a new sk for the socket to be returned by accept(). */
 626 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 627                                              struct sctp_association *asoc)
 628 {
 629         struct inet_sock *inet = inet_sk(sk);
 630         struct sock *newsk;
 631         struct inet_sock *newinet;
 632         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 633         struct sctp6_sock *newsctp6sk;
 634
 635         newsk = sk_alloc(sk->sk_net, PF_INET6, GFP_KERNEL, sk->sk_prot);
 636         if (!newsk)
 637                 goto out;
 638
 639         sock_init_data(NULL, newsk);
 640
 641         newsk->sk_type = SOCK_STREAM;
 642
 643         newsk->sk_prot = sk->sk_prot;
 644         newsk->sk_no_check = sk->sk_no_check;
 645         newsk->sk_reuse = sk->sk_reuse;
 646
 647         newsk->sk_destruct = inet_sock_destruct;
 648         newsk->sk_family = PF_INET6;
 649         newsk->sk_protocol = IPPROTO_SCTP;
 650         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 651         newsk->sk_shutdown = sk->sk_shutdown;
 652         sock_reset_flag(sk, SOCK_ZAPPED);
 653
 654         newsctp6sk = (struct sctp6_sock *)newsk;
 655         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 656
 657         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 658
 659         newinet = inet_sk(newsk);
 660         newnp = inet6_sk(newsk);
 661
 662         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 663
 664         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 665          * and getpeername().
 666          */
 667         newinet->sport = inet->sport;
 668         newnp->saddr = np->saddr;
 669         newnp->rcv_saddr = np->rcv_saddr;
 670         newinet->dport = htons(asoc->peer.port);
 671         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 672
 673         /* Init the ipv4 part of the socket since we can have sockets
 674          * using v6 API for ipv4.
 675          */
 676         newinet->uc_ttl = -1;
 677         newinet->mc_loop = 1;
 678         newinet->mc_ttl = 1;
 679         newinet->mc_index = 0;
 680         newinet->mc_list = NULL;
 681
 682         if (ipv4_config.no_pmtu_disc)
 683                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 684         else
 685                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 686
 687         sk_refcnt_debug_inc(newsk);
 688
 689         if (newsk->sk_prot->init(newsk)) {
 690                 sk_common_release(newsk);
 691                 newsk = NULL;
 692         }
 693
 694 out:
 695         return newsk;
 696 }
 697
 698 /* Map v4 address to mapped v6 address */
 699 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 700 {
 701         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 702                 sctp_v4_map_v6(addr);
 703 }
 704
 705 /* Where did this skb come from?  */
 706 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 707 {
 708         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 709         return opt->iif;
 710 }
 711
 712 /* Was this packet marked by Explicit Congestion Notification? */
 713 static int sctp_v6_is_ce(const struct sk_buff *skb)
 714 {
 715         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 716 }
 717
 718 /* Dump the v6 addr to the seq file. */
 719 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 720 {
 721         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
 722 }
 723
 724 /* Initialize a PF_INET6 socket msg_name. */
 725 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 726 {
 727         struct sockaddr_in6 *sin6;
 728
 729         sin6 = (struct sockaddr_in6 *)msgname;
 730         sin6->sin6_family = AF_INET6;
 731         sin6->sin6_flowinfo = 0;
 732         sin6->sin6_scope_id = 0; /*FIXME */
 733         *addr_len = sizeof(struct sockaddr_in6);
 734 }
 735
 736 /* Initialize a PF_INET msgname from a ulpevent. */
 737 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 738                                      char *msgname, int *addrlen)
 739 {
 740         struct sockaddr_in6 *sin6, *sin6from;
 741
 742         if (msgname) {
 743                 union sctp_addr *addr;
 744                 struct sctp_association *asoc;
 745
 746                 asoc = event->asoc;
 747                 sctp_inet6_msgname(msgname, addrlen);
 748                 sin6 = (struct sockaddr_in6 *)msgname;
 749                 sin6->sin6_port = htons(asoc->peer.port);
 750                 addr = &asoc->peer.primary_addr;
 751
 752                 /* Note: If we go to a common v6 format, this code
 753                  * will change.
 754                  */
 755
 756                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 757                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 758                     AF_INET == addr->sa.sa_family) {
 759                         sctp_v4_map_v6((union sctp_addr *)sin6);
 760                         sin6->sin6_addr.s6_addr32[3] =
 761                                 addr->v4.sin_addr.s_addr;
 762                         return;
 763                 }
 764
 765                 sin6from = &asoc->peer.primary_addr.v6;
 766                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 767                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 768                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 769         }
 770 }
 771
 772 /* Initialize a msg_name from an inbound skb. */
 773 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 774                                    int *addr_len)
 775 {
 776         struct sctphdr *sh;
 777         struct sockaddr_in6 *sin6;
 778
 779         if (msgname) {
 780                 sctp_inet6_msgname(msgname, addr_len);
 781                 sin6 = (struct sockaddr_in6 *)msgname;
 782                 sh = sctp_hdr(skb);
 783                 sin6->sin6_port = sh->source;
 784
 785                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 786                 if (sctp_sk(skb->sk)->v4mapped &&
 787                     ip_hdr(skb)->version == 4) {
 788                         sctp_v4_map_v6((union sctp_addr *)sin6);
 789                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 790                         return;
 791                 }
 792
 793                 /* Otherwise, just copy the v6 address. */
 794                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 795                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 796                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 797                         sin6->sin6_scope_id = ev->iif;
 798                 }
 799         }
 800 }
 801
 802 /* Do we support this AF? */
 803 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 804 {
 805         switch (family) {
 806         case AF_INET6:
 807                 return 1;
 808         /* v4-mapped-v6 addresses */
 809         case AF_INET:
 810                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
 811                         return 1;
 812         default:
 813                 return 0;
 814         }
 815 }
 816
 817 /* Address matching with wildcards allowed.  This extra level
 818  * of indirection lets us choose whether a PF_INET6 should
 819  * disallow any v4 addresses if we so choose.
 820  */
 821 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 822                                const union sctp_addr *addr2,
 823                                struct sctp_sock *opt)
 824 {
 825         struct sctp_af *af1, *af2;
 826
 827         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 828         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 829
 830         if (!af1 || !af2)
 831                 return 0;
 832         /* Today, wildcard AF_INET/AF_INET6. */
 833         if (sctp_is_any(addr1) || sctp_is_any(addr2))
 834                 return 1;
 835
 836         if (addr1->sa.sa_family != addr2->sa.sa_family)
 837                 return 0;
 838
 839         return af1->cmp_addr(addr1, addr2);
 840 }
 841
 842 /* Verify that the provided sockaddr looks bindable.   Common verification,
 843  * has already been taken care of.
 844  */
 845 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 846 {
 847         struct sctp_af *af;
 848
 849         /* ASSERT: address family has already been verified. */
 850         if (addr->sa.sa_family != AF_INET6)
 851                 af = sctp_get_af_specific(addr->sa.sa_family);
 852         else {
 853                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 854                 struct net_device *dev;
 855
 856                 if (type & IPV6_ADDR_LINKLOCAL) {
 857                         if (!addr->v6.sin6_scope_id)
 858                                 return 0;
 859                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 860                         if (!dev)
 861                                 return 0;
 862                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 863                                            dev, 0)) {
 864                                 dev_put(dev);
 865                                 return 0;
 866                         }
 867                         dev_put(dev);
 868                 }
 869                 af = opt->pf->af;
 870         }
 871         return af->available(addr, opt);
 872 }
 873
 874 /* Verify that the provided sockaddr looks sendable.   Common verification,
 875  * has already been taken care of.
 876  */
 877 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 878 {
 879         struct sctp_af *af = NULL;
 880
 881         /* ASSERT: address family has already been verified. */
 882         if (addr->sa.sa_family != AF_INET6)
 883                 af = sctp_get_af_specific(addr->sa.sa_family);
 884         else {
 885                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 886                 struct net_device *dev;
 887
 888                 if (type & IPV6_ADDR_LINKLOCAL) {
 889                         if (!addr->v6.sin6_scope_id)
 890                                 return 0;
 891                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 892                         if (!dev)
 893                                 return 0;
 894                         dev_put(dev);
 895                 }
 896                 af = opt->pf->af;
 897         }
 898
 899         return af != NULL;
 900 }
 901
 902 /* Fill in Supported Address Type information for INIT and INIT-ACK
 903  * chunks.   Note: In the future, we may want to look at sock options
 904  * to determine whether a PF_INET6 socket really wants to have IPV4
 905  * addresses.
 906  * Returns number of addresses supported.
 907  */
 908 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 909                                       __be16 *types)
 910 {
 911         types[0] = SCTP_PARAM_IPV4_ADDRESS;
 912         types[1] = SCTP_PARAM_IPV6_ADDRESS;
 913         return 2;
 914 }
 915
 916 static const struct proto_ops inet6_seqpacket_ops = {
 917         .family            = PF_INET6,
 918         .owner             = THIS_MODULE,
 919         .release           = inet6_release,
 920         .bind              = inet6_bind,
 921         .connect           = inet_dgram_connect,
 922         .socketpair        = sock_no_socketpair,
 923         .accept            = inet_accept,
 924         .getname           = inet6_getname,
 925         .poll              = sctp_poll,
 926         .ioctl             = inet6_ioctl,
 927         .listen            = sctp_inet_listen,
 928         .shutdown          = inet_shutdown,
 929         .setsockopt        = sock_common_setsockopt,
 930         .getsockopt        = sock_common_getsockopt,
 931         .sendmsg           = inet_sendmsg,
 932         .recvmsg           = sock_common_recvmsg,
 933         .mmap              = sock_no_mmap,
 934 #ifdef CONFIG_COMPAT
 935         .compat_setsockopt = compat_sock_common_setsockopt,
 936         .compat_getsockopt = compat_sock_common_getsockopt,
 937 #endif
 938 };
 939
 940 static struct inet_protosw sctpv6_seqpacket_protosw = {
 941         .type          = SOCK_SEQPACKET,
 942         .protocol      = IPPROTO_SCTP,
 943         .prot          = &sctpv6_prot,
 944         .ops           = &inet6_seqpacket_ops,
 945         .capability    = -1,
 946         .no_check      = 0,
 947         .flags         = SCTP_PROTOSW_FLAG
 948 };
 949 static struct inet_protosw sctpv6_stream_protosw = {
 950         .type          = SOCK_STREAM,
 951         .protocol      = IPPROTO_SCTP,
 952         .prot          = &sctpv6_prot,
 953         .ops           = &inet6_seqpacket_ops,
 954         .capability    = -1,
 955         .no_check      = 0,
 956         .flags         = SCTP_PROTOSW_FLAG,
 957 };
 958
 959 static int sctp6_rcv(struct sk_buff *skb)
 960 {
 961         return sctp_rcv(skb) ? -1 : 0;
 962 }
 963
 964 static struct inet6_protocol sctpv6_protocol = {
 965         .handler      = sctp6_rcv,
 966         .err_handler  = sctp_v6_err,
 967         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 968 };
 969
 970 static struct sctp_af sctp_af_inet6 = {
 971         .sa_family         = AF_INET6,
 972         .sctp_xmit         = sctp_v6_xmit,
 973         .setsockopt        = ipv6_setsockopt,
 974         .getsockopt        = ipv6_getsockopt,
 975         .get_dst           = sctp_v6_get_dst,
 976         .get_saddr         = sctp_v6_get_saddr,
 977         .copy_addrlist     = sctp_v6_copy_addrlist,
 978         .from_skb          = sctp_v6_from_skb,
 979         .from_sk           = sctp_v6_from_sk,
 980         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 981         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 982         .from_addr_param   = sctp_v6_from_addr_param,
 983         .to_addr_param     = sctp_v6_to_addr_param,
 984         .dst_saddr         = sctp_v6_dst_saddr,
 985         .cmp_addr          = sctp_v6_cmp_addr,
 986         .scope             = sctp_v6_scope,
 987         .addr_valid        = sctp_v6_addr_valid,
 988         .inaddr_any        = sctp_v6_inaddr_any,
 989         .is_any            = sctp_v6_is_any,
 990         .available         = sctp_v6_available,
 991         .skb_iif           = sctp_v6_skb_iif,
 992         .is_ce             = sctp_v6_is_ce,
 993         .seq_dump_addr     = sctp_v6_seq_dump_addr,
 994         .net_header_len    = sizeof(struct ipv6hdr),
 995         .sockaddr_len      = sizeof(struct sockaddr_in6),
 996 #ifdef CONFIG_COMPAT
 997         .compat_setsockopt = compat_ipv6_setsockopt,
 998         .compat_getsockopt = compat_ipv6_getsockopt,
 999 #endif
1000 };
1001
1002 static struct sctp_pf sctp_pf_inet6 = {
1003         .event_msgname = sctp_inet6_event_msgname,
1004         .skb_msgname   = sctp_inet6_skb_msgname,
1005         .af_supported  = sctp_inet6_af_supported,
1006         .cmp_addr      = sctp_inet6_cmp_addr,
1007         .bind_verify   = sctp_inet6_bind_verify,
1008         .send_verify   = sctp_inet6_send_verify,
1009         .supported_addrs = sctp_inet6_supported_addrs,
1010         .create_accept_sk = sctp_v6_create_accept_sk,
1011         .addr_v4map    = sctp_v6_addr_v4map,
1012         .af            = &sctp_af_inet6,
1013 };
1014
1015 /* Initialize IPv6 support and register with socket layer.  */
1016 int sctp_v6_init(void)
1017 {
1018         int rc;
1019
1020         /* Register the SCTP specific PF_INET6 functions. */
1021         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1022
1023         /* Register the SCTP specific AF_INET6 functions. */
1024         sctp_register_af(&sctp_af_inet6);
1025
1026         rc = proto_register(&sctpv6_prot, 1);
1027         if (rc)
1028                 return rc;
1029
1030         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1031         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1032         inet6_register_protosw(&sctpv6_stream_protosw);
1033
1034         return 0;
1035 }
1036
1037 /* Register with inet6 layer. */
1038 int sctp_v6_add_protocol(void)
1039 {
1040         /* Register notifier for inet6 address additions/deletions. */
1041         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1042
1043         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1044                 return -EAGAIN;
1045
1046         return 0;
1047 }
1048
1049 /* IPv6 specific exit support. */
1050 void sctp_v6_exit(void)
1051 {
1052         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1053         inet6_unregister_protosw(&sctpv6_stream_protosw);
1054         proto_unregister(&sctpv6_prot);
1055         list_del(&sctp_af_inet6.list);
1056 }
1057
1058 /* Unregister with inet6 layer. */
1059 void sctp_v6_del_protocol(void)
1060 {
1061         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1062         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1063 }