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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         int found = 0;
  93
  94         switch (ev) {
  95         case NETDEV_UP:
  96                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  97                 if (addr) {
  98                         addr->a.v6.sin6_family = AF_INET6;
  99                         addr->a.v6.sin6_port = 0;
 100                         memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
 101                                  sizeof(struct in6_addr));
 102                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 103                         addr->valid = 1;
 104                         spin_lock_bh(&sctp_local_addr_lock);
 105                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
 106                         spin_unlock_bh(&sctp_local_addr_lock);
 107                 }
 108                 break;
 109         case NETDEV_DOWN:
 110                 spin_lock_bh(&sctp_local_addr_lock);
 111                 list_for_each_entry_safe(addr, temp,
 112                                         &sctp_local_addr_list, list) {
 113                         if (ipv6_addr_equal(&addr->a.v6.sin6_addr,
 114                                              &ifa->addr)) {
 115                                 found = 1;
 116                                 addr->valid = 0;
 117                                 list_del_rcu(&addr->list);
 118                                 break;
 119                         }
 120                 }
 121                 spin_unlock_bh(&sctp_local_addr_lock);
 122                 if (found)
 123                         call_rcu(&addr->rcu, sctp_local_addr_free);
 124                 break;
 125         }
 126
 127         return NOTIFY_DONE;
 128 }
 129
 130 static struct notifier_block sctp_inet6addr_notifier = {
 131         .notifier_call = sctp_inet6addr_event,
 132 };
 133
 134 /* ICMP error handler. */
 135 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 136                              int type, int code, int offset, __be32 info)
 137 {
 138         struct inet6_dev *idev;
 139         struct sock *sk;
 140         struct sctp_association *asoc;
 141         struct sctp_transport *transport;
 142         struct ipv6_pinfo *np;
 143         sk_buff_data_t saveip, savesctp;
 144         int err;
 145
 146         idev = in6_dev_get(skb->dev);
 147
 148         /* Fix up skb to look at the embedded net header. */
 149         saveip   = skb->network_header;
 150         savesctp = skb->transport_header;
 151         skb_reset_network_header(skb);
 152         skb_set_transport_header(skb, offset);
 153         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 154         /* Put back, the original pointers. */
 155         skb->network_header   = saveip;
 156         skb->transport_header = savesctp;
 157         if (!sk) {
 158                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 159                 goto out;
 160         }
 161
 162         /* Warning:  The sock lock is held.  Remember to call
 163          * sctp_err_finish!
 164          */
 165
 166         switch (type) {
 167         case ICMPV6_PKT_TOOBIG:
 168                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 169                 goto out_unlock;
 170         case ICMPV6_PARAMPROB:
 171                 if (ICMPV6_UNK_NEXTHDR == code) {
 172                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 173                         goto out_unlock;
 174                 }
 175                 break;
 176         default:
 177                 break;
 178         }
 179
 180         np = inet6_sk(sk);
 181         icmpv6_err_convert(type, code, &err);
 182         if (!sock_owned_by_user(sk) && np->recverr) {
 183                 sk->sk_err = err;
 184                 sk->sk_error_report(sk);
 185         } else {  /* Only an error on timeout */
 186                 sk->sk_err_soft = err;
 187         }
 188
 189 out_unlock:
 190         sctp_err_finish(sk, asoc);
 191 out:
 192         if (likely(idev != NULL))
 193                 in6_dev_put(idev);
 194 }
 195
 196 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 197 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
 198                         int ipfragok)
 199 {
 200         struct sock *sk = skb->sk;
 201         struct ipv6_pinfo *np = inet6_sk(sk);
 202         struct flowi fl;
 203
 204         memset(&fl, 0, sizeof(fl));
 205
 206         fl.proto = sk->sk_protocol;
 207
 208         /* Fill in the dest address from the route entry passed with the skb
 209          * and the source address from the transport.
 210          */
 211         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 212         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 213
 214         fl.fl6_flowlabel = np->flow_label;
 215         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 216         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 217                 fl.oif = transport->saddr.v6.sin6_scope_id;
 218         else
 219                 fl.oif = sk->sk_bound_dev_if;
 220
 221         if (np->opt && np->opt->srcrt) {
 222                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 223                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 224         }
 225
 226         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
 227                           "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
 228                           __func__, skb, skb->len,
 229                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
 230
 231         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 232
 233         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
 234 }
 235
 236 /* Returns the dst cache entry for the given source and destination ip
 237  * addresses.
 238  */
 239 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 240                                          union sctp_addr *daddr,
 241                                          union sctp_addr *saddr)
 242 {
 243         struct dst_entry *dst;
 244         struct flowi fl;
 245
 246         memset(&fl, 0, sizeof(fl));
 247         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 248         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 249                 fl.oif = daddr->v6.sin6_scope_id;
 250
 251
 252         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
 253                           __func__, NIP6(fl.fl6_dst));
 254
 255         if (saddr) {
 256                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 257                 SCTP_DEBUG_PRINTK(
 258                         "SRC=" NIP6_FMT " - ",
 259                         NIP6(fl.fl6_src));
 260         }
 261
 262         dst = ip6_route_output(&init_net, NULL, &fl);
 263         if (!dst->error) {
 264                 struct rt6_info *rt;
 265                 rt = (struct rt6_info *)dst;
 266                 SCTP_DEBUG_PRINTK(
 267                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
 268                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
 269                 return dst;
 270         }
 271         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 272         dst_release(dst);
 273         return NULL;
 274 }
 275
 276 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 277  * addresses.
 278  */
 279 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 280                                          union sctp_addr *s2)
 281 {
 282         struct in6_addr *a1 = &s1->v6.sin6_addr;
 283         struct in6_addr *a2 = &s2->v6.sin6_addr;
 284         int i, j;
 285
 286         for (i = 0; i < 4 ; i++) {
 287                 __be32 a1xora2;
 288
 289                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 290
 291                 if ((j = fls(ntohl(a1xora2))))
 292                         return (i * 32 + 32 - j);
 293         }
 294
 295         return (i*32);
 296 }
 297
 298 /* Fills in the source address(saddr) based on the destination address(daddr)
 299  * and asoc's bind address list.
 300  */
 301 static void sctp_v6_get_saddr(struct sctp_association *asoc,
 302                               struct dst_entry *dst,
 303                               union sctp_addr *daddr,
 304                               union sctp_addr *saddr)
 305 {
 306         struct sctp_bind_addr *bp;
 307         struct sctp_sockaddr_entry *laddr;
 308         sctp_scope_t scope;
 309         union sctp_addr *baddr = NULL;
 310         __u8 matchlen = 0;
 311         __u8 bmatchlen;
 312
 313         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
 314                           "daddr:" NIP6_FMT " ",
 315                           __func__, asoc, dst, NIP6(daddr->v6.sin6_addr));
 316
 317         if (!asoc) {
 318                 ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL,
 319                                    &daddr->v6.sin6_addr,
 320                                    inet6_sk(asoc->base.sk)->srcprefs,
 321                                    &saddr->v6.sin6_addr);
 322                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
 323                                   NIP6(saddr->v6.sin6_addr));
 324                 return;
 325         }
 326
 327         scope = sctp_scope(daddr);
 328
 329         bp = &asoc->base.bind_addr;
 330
 331         /* Go through the bind address list and find the best source address
 332          * that matches the scope of the destination address.
 333          */
 334         rcu_read_lock();
 335         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 336                 if (!laddr->valid)
 337                         continue;
 338                 if ((laddr->state == SCTP_ADDR_SRC) &&
 339                     (laddr->a.sa.sa_family == AF_INET6) &&
 340                     (scope <= sctp_scope(&laddr->a))) {
 341                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 342                         if (!baddr || (matchlen < bmatchlen)) {
 343                                 baddr = &laddr->a;
 344                                 matchlen = bmatchlen;
 345                         }
 346                 }
 347         }
 348
 349         if (baddr) {
 350                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 351                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
 352                                   NIP6(saddr->v6.sin6_addr));
 353         } else {
 354                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 355                        "address for the dest:" NIP6_FMT "\n",
 356                        __func__, asoc, NIP6(daddr->v6.sin6_addr));
 357         }
 358
 359         rcu_read_unlock();
 360 }
 361
 362 /* Make a copy of all potential local addresses. */
 363 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 364                                   struct net_device *dev)
 365 {
 366         struct inet6_dev *in6_dev;
 367         struct inet6_ifaddr *ifp;
 368         struct sctp_sockaddr_entry *addr;
 369
 370         rcu_read_lock();
 371         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 372                 rcu_read_unlock();
 373                 return;
 374         }
 375
 376         read_lock_bh(&in6_dev->lock);
 377         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 378                 /* Add the address to the local list.  */
 379                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 380                 if (addr) {
 381                         addr->a.v6.sin6_family = AF_INET6;
 382                         addr->a.v6.sin6_port = 0;
 383                         addr->a.v6.sin6_addr = ifp->addr;
 384                         addr->a.v6.sin6_scope_id = dev->ifindex;
 385                         addr->valid = 1;
 386                         INIT_LIST_HEAD(&addr->list);
 387                         INIT_RCU_HEAD(&addr->rcu);
 388                         list_add_tail(&addr->list, addrlist);
 389                 }
 390         }
 391
 392         read_unlock_bh(&in6_dev->lock);
 393         rcu_read_unlock();
 394 }
 395
 396 /* Initialize a sockaddr_storage from in incoming skb. */
 397 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 398                              int is_saddr)
 399 {
 400         void *from;
 401         __be16 *port;
 402         struct sctphdr *sh;
 403
 404         port = &addr->v6.sin6_port;
 405         addr->v6.sin6_family = AF_INET6;
 406         addr->v6.sin6_flowinfo = 0; /* FIXME */
 407         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 408
 409         sh = sctp_hdr(skb);
 410         if (is_saddr) {
 411                 *port  = sh->source;
 412                 from = &ipv6_hdr(skb)->saddr;
 413         } else {
 414                 *port = sh->dest;
 415                 from = &ipv6_hdr(skb)->daddr;
 416         }
 417         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 418 }
 419
 420 /* Initialize an sctp_addr from a socket. */
 421 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 422 {
 423         addr->v6.sin6_family = AF_INET6;
 424         addr->v6.sin6_port = 0;
 425         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 426 }
 427
 428 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 429 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 430 {
 431         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 432                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 433                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 434                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 435                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 436                         addr->v4.sin_addr.s_addr;
 437         } else {
 438                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 439         }
 440 }
 441
 442 /* Initialize sk->sk_daddr from sctp_addr. */
 443 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 444 {
 445         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 446                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 447                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 448                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 449                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 450         } else {
 451                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 452         }
 453 }
 454
 455 /* Initialize a sctp_addr from an address parameter. */
 456 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 457                                     union sctp_addr_param *param,
 458                                     __be16 port, int iif)
 459 {
 460         addr->v6.sin6_family = AF_INET6;
 461         addr->v6.sin6_port = port;
 462         addr->v6.sin6_flowinfo = 0; /* BUG */
 463         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 464         addr->v6.sin6_scope_id = iif;
 465 }
 466
 467 /* Initialize an address parameter from a sctp_addr and return the length
 468  * of the address parameter.
 469  */
 470 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 471                                  union sctp_addr_param *param)
 472 {
 473         int length = sizeof(sctp_ipv6addr_param_t);
 474
 475         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 476         param->v6.param_hdr.length = htons(length);
 477         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 478
 479         return length;
 480 }
 481
 482 /* Initialize a sctp_addr from a dst_entry. */
 483 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 484                               __be16 port)
 485 {
 486         struct rt6_info *rt = (struct rt6_info *)dst;
 487         addr->sa.sa_family = AF_INET6;
 488         addr->v6.sin6_port = port;
 489         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 490 }
 491
 492 /* Compare addresses exactly.
 493  * v4-mapped-v6 is also in consideration.
 494  */
 495 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 496                             const union sctp_addr *addr2)
 497 {
 498         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 499                 if (addr1->sa.sa_family == AF_INET &&
 500                     addr2->sa.sa_family == AF_INET6 &&
 501                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 502                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 503                             addr2->v6.sin6_addr.s6_addr32[3] ==
 504                             addr1->v4.sin_addr.s_addr)
 505                                 return 1;
 506                 }
 507                 if (addr2->sa.sa_family == AF_INET &&
 508                     addr1->sa.sa_family == AF_INET6 &&
 509                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 510                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 511                             addr1->v6.sin6_addr.s6_addr32[3] ==
 512                             addr2->v4.sin_addr.s_addr)
 513                                 return 1;
 514                 }
 515                 return 0;
 516         }
 517         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 518                 return 0;
 519         /* If this is a linklocal address, compare the scope_id. */
 520         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 521                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 522                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 523                         return 0;
 524                 }
 525         }
 526
 527         return 1;
 528 }
 529
 530 /* Initialize addr struct to INADDR_ANY. */
 531 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 532 {
 533         memset(addr, 0x00, sizeof(union sctp_addr));
 534         addr->v6.sin6_family = AF_INET6;
 535         addr->v6.sin6_port = port;
 536 }
 537
 538 /* Is this a wildcard address? */
 539 static int sctp_v6_is_any(const union sctp_addr *addr)
 540 {
 541         return ipv6_addr_any(&addr->v6.sin6_addr);
 542 }
 543
 544 /* Should this be available for binding?   */
 545 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 546 {
 547         int type;
 548         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 549
 550         type = ipv6_addr_type(in6);
 551         if (IPV6_ADDR_ANY == type)
 552                 return 1;
 553         if (type == IPV6_ADDR_MAPPED) {
 554                 if (sp && !sp->v4mapped)
 555                         return 0;
 556                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 557                         return 0;
 558                 sctp_v6_map_v4(addr);
 559                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 560         }
 561         if (!(type & IPV6_ADDR_UNICAST))
 562                 return 0;
 563
 564         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 565 }
 566
 567 /* This function checks if the address is a valid address to be used for
 568  * SCTP.
 569  *
 570  * Output:
 571  * Return 0 - If the address is a non-unicast or an illegal address.
 572  * Return 1 - If the address is a unicast.
 573  */
 574 static int sctp_v6_addr_valid(union sctp_addr *addr,
 575                               struct sctp_sock *sp,
 576                               const struct sk_buff *skb)
 577 {
 578         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 579
 580         /* Support v4-mapped-v6 address. */
 581         if (ret == IPV6_ADDR_MAPPED) {
 582                 /* Note: This routine is used in input, so v4-mapped-v6
 583                  * are disallowed here when there is no sctp_sock.
 584                  */
 585                 if (!sp || !sp->v4mapped)
 586                         return 0;
 587                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 588                         return 0;
 589                 sctp_v6_map_v4(addr);
 590                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 591         }
 592
 593         /* Is this a non-unicast address */
 594         if (!(ret & IPV6_ADDR_UNICAST))
 595                 return 0;
 596
 597         return 1;
 598 }
 599
 600 /* What is the scope of 'addr'?  */
 601 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 602 {
 603         int v6scope;
 604         sctp_scope_t retval;
 605
 606         /* The IPv6 scope is really a set of bit fields.
 607          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 608          */
 609
 610         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 611         switch (v6scope) {
 612         case IFA_HOST:
 613                 retval = SCTP_SCOPE_LOOPBACK;
 614                 break;
 615         case IFA_LINK:
 616                 retval = SCTP_SCOPE_LINK;
 617                 break;
 618         case IFA_SITE:
 619                 retval = SCTP_SCOPE_PRIVATE;
 620                 break;
 621         default:
 622                 retval = SCTP_SCOPE_GLOBAL;
 623                 break;
 624         }
 625
 626         return retval;
 627 }
 628
 629 /* Create and initialize a new sk for the socket to be returned by accept(). */
 630 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 631                                              struct sctp_association *asoc)
 632 {
 633         struct inet_sock *inet = inet_sk(sk);
 634         struct sock *newsk;
 635         struct inet_sock *newinet;
 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);
 640         if (!newsk)
 641                 goto out;
 642
 643         sock_init_data(NULL, newsk);
 644
 645         newsk->sk_type = SOCK_STREAM;
 646
 647         newsk->sk_prot = sk->sk_prot;
 648         newsk->sk_no_check = sk->sk_no_check;
 649         newsk->sk_reuse = sk->sk_reuse;
 650
 651         newsk->sk_destruct = inet_sock_destruct;
 652         newsk->sk_family = PF_INET6;
 653         newsk->sk_protocol = IPPROTO_SCTP;
 654         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 655         newsk->sk_shutdown = sk->sk_shutdown;
 656         sock_reset_flag(sk, SOCK_ZAPPED);
 657
 658         newsctp6sk = (struct sctp6_sock *)newsk;
 659         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 660
 661         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 662
 663         newinet = inet_sk(newsk);
 664         newnp = inet6_sk(newsk);
 665
 666         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 667
 668         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 669          * and getpeername().
 670          */
 671         newinet->sport = inet->sport;
 672         newnp->saddr = np->saddr;
 673         newnp->rcv_saddr = np->rcv_saddr;
 674         newinet->dport = htons(asoc->peer.port);
 675         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 676
 677         /* Init the ipv4 part of the socket since we can have sockets
 678          * using v6 API for ipv4.
 679          */
 680         newinet->uc_ttl = -1;
 681         newinet->mc_loop = 1;
 682         newinet->mc_ttl = 1;
 683         newinet->mc_index = 0;
 684         newinet->mc_list = NULL;
 685
 686         if (ipv4_config.no_pmtu_disc)
 687                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 688         else
 689                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 690
 691         sk_refcnt_debug_inc(newsk);
 692
 693         if (newsk->sk_prot->init(newsk)) {
 694                 sk_common_release(newsk);
 695                 newsk = NULL;
 696         }
 697
 698 out:
 699         return newsk;
 700 }
 701
 702 /* Map v4 address to mapped v6 address */
 703 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 704 {
 705         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 706                 sctp_v4_map_v6(addr);
 707 }
 708
 709 /* Where did this skb come from?  */
 710 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 711 {
 712         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 713         return opt->iif;
 714 }
 715
 716 /* Was this packet marked by Explicit Congestion Notification? */
 717 static int sctp_v6_is_ce(const struct sk_buff *skb)
 718 {
 719         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 720 }
 721
 722 /* Dump the v6 addr to the seq file. */
 723 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 724 {
 725         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
 726 }
 727
 728 /* Initialize a PF_INET6 socket msg_name. */
 729 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 730 {
 731         struct sockaddr_in6 *sin6;
 732
 733         sin6 = (struct sockaddr_in6 *)msgname;
 734         sin6->sin6_family = AF_INET6;
 735         sin6->sin6_flowinfo = 0;
 736         sin6->sin6_scope_id = 0; /*FIXME */
 737         *addr_len = sizeof(struct sockaddr_in6);
 738 }
 739
 740 /* Initialize a PF_INET msgname from a ulpevent. */
 741 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 742                                      char *msgname, int *addrlen)
 743 {
 744         struct sockaddr_in6 *sin6, *sin6from;
 745
 746         if (msgname) {
 747                 union sctp_addr *addr;
 748                 struct sctp_association *asoc;
 749
 750                 asoc = event->asoc;
 751                 sctp_inet6_msgname(msgname, addrlen);
 752                 sin6 = (struct sockaddr_in6 *)msgname;
 753                 sin6->sin6_port = htons(asoc->peer.port);
 754                 addr = &asoc->peer.primary_addr;
 755
 756                 /* Note: If we go to a common v6 format, this code
 757                  * will change.
 758                  */
 759
 760                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 761                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 762                     AF_INET == addr->sa.sa_family) {
 763                         sctp_v4_map_v6((union sctp_addr *)sin6);
 764                         sin6->sin6_addr.s6_addr32[3] =
 765                                 addr->v4.sin_addr.s_addr;
 766                         return;
 767                 }
 768
 769                 sin6from = &asoc->peer.primary_addr.v6;
 770                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 771                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 772                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 773         }
 774 }
 775
 776 /* Initialize a msg_name from an inbound skb. */
 777 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 778                                    int *addr_len)
 779 {
 780         struct sctphdr *sh;
 781         struct sockaddr_in6 *sin6;
 782
 783         if (msgname) {
 784                 sctp_inet6_msgname(msgname, addr_len);
 785                 sin6 = (struct sockaddr_in6 *)msgname;
 786                 sh = sctp_hdr(skb);
 787                 sin6->sin6_port = sh->source;
 788
 789                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 790                 if (sctp_sk(skb->sk)->v4mapped &&
 791                     ip_hdr(skb)->version == 4) {
 792                         sctp_v4_map_v6((union sctp_addr *)sin6);
 793                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 794                         return;
 795                 }
 796
 797                 /* Otherwise, just copy the v6 address. */
 798                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 799                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 800                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 801                         sin6->sin6_scope_id = ev->iif;
 802                 }
 803         }
 804 }
 805
 806 /* Do we support this AF? */
 807 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 808 {
 809         switch (family) {
 810         case AF_INET6:
 811                 return 1;
 812         /* v4-mapped-v6 addresses */
 813         case AF_INET:
 814                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
 815                         return 1;
 816         default:
 817                 return 0;
 818         }
 819 }
 820
 821 /* Address matching with wildcards allowed.  This extra level
 822  * of indirection lets us choose whether a PF_INET6 should
 823  * disallow any v4 addresses if we so choose.
 824  */
 825 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 826                                const union sctp_addr *addr2,
 827                                struct sctp_sock *opt)
 828 {
 829         struct sctp_af *af1, *af2;
 830
 831         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 832         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 833
 834         if (!af1 || !af2)
 835                 return 0;
 836         /* Today, wildcard AF_INET/AF_INET6. */
 837         if (sctp_is_any(addr1) || sctp_is_any(addr2))
 838                 return 1;
 839
 840         if (addr1->sa.sa_family != addr2->sa.sa_family)
 841                 return 0;
 842
 843         return af1->cmp_addr(addr1, addr2);
 844 }
 845
 846 /* Verify that the provided sockaddr looks bindable.   Common verification,
 847  * has already been taken care of.
 848  */
 849 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 850 {
 851         struct sctp_af *af;
 852
 853         /* ASSERT: address family has already been verified. */
 854         if (addr->sa.sa_family != AF_INET6)
 855                 af = sctp_get_af_specific(addr->sa.sa_family);
 856         else {
 857                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 858                 struct net_device *dev;
 859
 860                 if (type & IPV6_ADDR_LINKLOCAL) {
 861                         if (!addr->v6.sin6_scope_id)
 862                                 return 0;
 863                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 864                         if (!dev)
 865                                 return 0;
 866                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 867                                            dev, 0)) {
 868                                 dev_put(dev);
 869                                 return 0;
 870                         }
 871                         dev_put(dev);
 872                 }
 873                 af = opt->pf->af;
 874         }
 875         return af->available(addr, opt);
 876 }
 877
 878 /* Verify that the provided sockaddr looks sendable.   Common verification,
 879  * has already been taken care of.
 880  */
 881 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 882 {
 883         struct sctp_af *af = NULL;
 884
 885         /* ASSERT: address family has already been verified. */
 886         if (addr->sa.sa_family != AF_INET6)
 887                 af = sctp_get_af_specific(addr->sa.sa_family);
 888         else {
 889                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 890                 struct net_device *dev;
 891
 892                 if (type & IPV6_ADDR_LINKLOCAL) {
 893                         if (!addr->v6.sin6_scope_id)
 894                                 return 0;
 895                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 896                         if (!dev)
 897                                 return 0;
 898                         dev_put(dev);
 899                 }
 900                 af = opt->pf->af;
 901         }
 902
 903         return af != NULL;
 904 }
 905
 906 /* Fill in Supported Address Type information for INIT and INIT-ACK
 907  * chunks.   Note: In the future, we may want to look at sock options
 908  * to determine whether a PF_INET6 socket really wants to have IPV4
 909  * addresses.
 910  * Returns number of addresses supported.
 911  */
 912 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 913                                       __be16 *types)
 914 {
 915         types[0] = SCTP_PARAM_IPV4_ADDRESS;
 916         types[1] = SCTP_PARAM_IPV6_ADDRESS;
 917         return 2;
 918 }
 919
 920 static const struct proto_ops inet6_seqpacket_ops = {
 921         .family            = PF_INET6,
 922         .owner             = THIS_MODULE,
 923         .release           = inet6_release,
 924         .bind              = inet6_bind,
 925         .connect           = inet_dgram_connect,
 926         .socketpair        = sock_no_socketpair,
 927         .accept            = inet_accept,
 928         .getname           = inet6_getname,
 929         .poll              = sctp_poll,
 930         .ioctl             = inet6_ioctl,
 931         .listen            = sctp_inet_listen,
 932         .shutdown          = inet_shutdown,
 933         .setsockopt        = sock_common_setsockopt,
 934         .getsockopt        = sock_common_getsockopt,
 935         .sendmsg           = inet_sendmsg,
 936         .recvmsg           = sock_common_recvmsg,
 937         .mmap              = sock_no_mmap,
 938 #ifdef CONFIG_COMPAT
 939         .compat_setsockopt = compat_sock_common_setsockopt,
 940         .compat_getsockopt = compat_sock_common_getsockopt,
 941 #endif
 942 };
 943
 944 static struct inet_protosw sctpv6_seqpacket_protosw = {
 945         .type          = SOCK_SEQPACKET,
 946         .protocol      = IPPROTO_SCTP,
 947         .prot          = &sctpv6_prot,
 948         .ops           = &inet6_seqpacket_ops,
 949         .capability    = -1,
 950         .no_check      = 0,
 951         .flags         = SCTP_PROTOSW_FLAG
 952 };
 953 static struct inet_protosw sctpv6_stream_protosw = {
 954         .type          = SOCK_STREAM,
 955         .protocol      = IPPROTO_SCTP,
 956         .prot          = &sctpv6_prot,
 957         .ops           = &inet6_seqpacket_ops,
 958         .capability    = -1,
 959         .no_check      = 0,
 960         .flags         = SCTP_PROTOSW_FLAG,
 961 };
 962
 963 static int sctp6_rcv(struct sk_buff *skb)
 964 {
 965         return sctp_rcv(skb) ? -1 : 0;
 966 }
 967
 968 static struct inet6_protocol sctpv6_protocol = {
 969         .handler      = sctp6_rcv,
 970         .err_handler  = sctp_v6_err,
 971         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 972 };
 973
 974 static struct sctp_af sctp_af_inet6 = {
 975         .sa_family         = AF_INET6,
 976         .sctp_xmit         = sctp_v6_xmit,
 977         .setsockopt        = ipv6_setsockopt,
 978         .getsockopt        = ipv6_getsockopt,
 979         .get_dst           = sctp_v6_get_dst,
 980         .get_saddr         = sctp_v6_get_saddr,
 981         .copy_addrlist     = sctp_v6_copy_addrlist,
 982         .from_skb          = sctp_v6_from_skb,
 983         .from_sk           = sctp_v6_from_sk,
 984         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 985         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 986         .from_addr_param   = sctp_v6_from_addr_param,
 987         .to_addr_param     = sctp_v6_to_addr_param,
 988         .dst_saddr         = sctp_v6_dst_saddr,
 989         .cmp_addr          = sctp_v6_cmp_addr,
 990         .scope             = sctp_v6_scope,
 991         .addr_valid        = sctp_v6_addr_valid,
 992         .inaddr_any        = sctp_v6_inaddr_any,
 993         .is_any            = sctp_v6_is_any,
 994         .available         = sctp_v6_available,
 995         .skb_iif           = sctp_v6_skb_iif,
 996         .is_ce             = sctp_v6_is_ce,
 997         .seq_dump_addr     = sctp_v6_seq_dump_addr,
 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_v4map    = sctp_v6_addr_v4map,
1016         .af            = &sctp_af_inet6,
1017 };
1018
1019 /* Initialize IPv6 support and register with socket layer.  */
1020 void sctp_v6_pf_init(void)
1021 {
1022         /* Register the SCTP specific PF_INET6 functions. */
1023         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1024
1025         /* Register the SCTP specific AF_INET6 functions. */
1026         sctp_register_af(&sctp_af_inet6);
1027 }
1028
1029 void sctp_v6_pf_exit(void)
1030 {
1031         list_del(&sctp_af_inet6.list);
1032 }
1033
1034 /* Initialize IPv6 support and register with socket layer.  */
1035 int sctp_v6_protosw_init(void)
1036 {
1037         int rc;
1038
1039         rc = proto_register(&sctpv6_prot, 1);
1040         if (rc)
1041                 return rc;
1042
1043         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1044         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1045         inet6_register_protosw(&sctpv6_stream_protosw);
1046
1047         return 0;
1048 }
1049
1050 void sctp_v6_protosw_exit(void)
1051 {
1052         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1053         inet6_unregister_protosw(&sctpv6_stream_protosw);
1054         proto_unregister(&sctpv6_prot);
1055 }
1056
1057
1058 /* Register with inet6 layer. */
1059 int sctp_v6_add_protocol(void)
1060 {
1061         /* Register notifier for inet6 address additions/deletions. */
1062         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1063
1064         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1065                 return -EAGAIN;
1066
1067         return 0;
1068 }
1069
1070 /* Unregister with inet6 layer. */
1071 void sctp_v6_del_protocol(void)
1072 {
1073         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1074         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1075 }