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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 (addr->a.sa.sa_family == AF_INET6 &&
 114                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 115                                                 &ifa->addr)) {
 116                                 found = 1;
 117                                 addr->valid = 0;
 118                                 list_del_rcu(&addr->list);
 119                                 break;
 120                         }
 121                 }
 122                 spin_unlock_bh(&sctp_local_addr_lock);
 123                 if (found)
 124                         call_rcu(&addr->rcu, sctp_local_addr_free);
 125                 break;
 126         }
 127
 128         return NOTIFY_DONE;
 129 }
 130
 131 static struct notifier_block sctp_inet6addr_notifier = {
 132         .notifier_call = sctp_inet6addr_event,
 133 };
 134
 135 /* ICMP error handler. */
 136 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 137                              int type, int code, int offset, __be32 info)
 138 {
 139         struct inet6_dev *idev;
 140         struct sock *sk;
 141         struct sctp_association *asoc;
 142         struct sctp_transport *transport;
 143         struct ipv6_pinfo *np;
 144         sk_buff_data_t saveip, savesctp;
 145         int err;
 146
 147         idev = in6_dev_get(skb->dev);
 148
 149         /* Fix up skb to look at the embedded net header. */
 150         saveip   = skb->network_header;
 151         savesctp = skb->transport_header;
 152         skb_reset_network_header(skb);
 153         skb_set_transport_header(skb, offset);
 154         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 155         /* Put back, the original pointers. */
 156         skb->network_header   = saveip;
 157         skb->transport_header = savesctp;
 158         if (!sk) {
 159                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 160                 goto out;
 161         }
 162
 163         /* Warning:  The sock lock is held.  Remember to call
 164          * sctp_err_finish!
 165          */
 166
 167         switch (type) {
 168         case ICMPV6_PKT_TOOBIG:
 169                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 170                 goto out_unlock;
 171         case ICMPV6_PARAMPROB:
 172                 if (ICMPV6_UNK_NEXTHDR == code) {
 173                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 174                         goto out_unlock;
 175                 }
 176                 break;
 177         default:
 178                 break;
 179         }
 180
 181         np = inet6_sk(sk);
 182         icmpv6_err_convert(type, code, &err);
 183         if (!sock_owned_by_user(sk) && np->recverr) {
 184                 sk->sk_err = err;
 185                 sk->sk_error_report(sk);
 186         } else {  /* Only an error on timeout */
 187                 sk->sk_err_soft = err;
 188         }
 189
 190 out_unlock:
 191         sctp_err_finish(sk, asoc);
 192 out:
 193         if (likely(idev != NULL))
 194                 in6_dev_put(idev);
 195 }
 196
 197 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 198 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
 199                         int ipfragok)
 200 {
 201         struct sock *sk = skb->sk;
 202         struct ipv6_pinfo *np = inet6_sk(sk);
 203         struct flowi fl;
 204
 205         memset(&fl, 0, sizeof(fl));
 206
 207         fl.proto = sk->sk_protocol;
 208
 209         /* Fill in the dest address from the route entry passed with the skb
 210          * and the source address from the transport.
 211          */
 212         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 213         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 214
 215         fl.fl6_flowlabel = np->flow_label;
 216         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 217         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 218                 fl.oif = transport->saddr.v6.sin6_scope_id;
 219         else
 220                 fl.oif = sk->sk_bound_dev_if;
 221
 222         if (np->opt && np->opt->srcrt) {
 223                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 224                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 225         }
 226
 227         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
 228                           "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
 229                           __func__, skb, skb->len,
 230                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
 231
 232         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 233
 234         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
 235 }
 236
 237 /* Returns the dst cache entry for the given source and destination ip
 238  * addresses.
 239  */
 240 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 241                                          union sctp_addr *daddr,
 242                                          union sctp_addr *saddr)
 243 {
 244         struct dst_entry *dst;
 245         struct flowi fl;
 246
 247         memset(&fl, 0, sizeof(fl));
 248         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 249         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 250                 fl.oif = daddr->v6.sin6_scope_id;
 251
 252
 253         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
 254                           __func__, NIP6(fl.fl6_dst));
 255
 256         if (saddr) {
 257                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 258                 SCTP_DEBUG_PRINTK(
 259                         "SRC=" NIP6_FMT " - ",
 260                         NIP6(fl.fl6_src));
 261         }
 262
 263         dst = ip6_route_output(&init_net, NULL, &fl);
 264         if (!dst->error) {
 265                 struct rt6_info *rt;
 266                 rt = (struct rt6_info *)dst;
 267                 SCTP_DEBUG_PRINTK(
 268                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
 269                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
 270                 return dst;
 271         }
 272         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 273         dst_release(dst);
 274         return NULL;
 275 }
 276
 277 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 278  * addresses.
 279  */
 280 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 281                                          union sctp_addr *s2)
 282 {
 283         struct in6_addr *a1 = &s1->v6.sin6_addr;
 284         struct in6_addr *a2 = &s2->v6.sin6_addr;
 285         int i, j;
 286
 287         for (i = 0; i < 4 ; i++) {
 288                 __be32 a1xora2;
 289
 290                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 291
 292                 if ((j = fls(ntohl(a1xora2))))
 293                         return (i * 32 + 32 - j);
 294         }
 295
 296         return (i*32);
 297 }
 298
 299 /* Fills in the source address(saddr) based on the destination address(daddr)
 300  * and asoc's bind address list.
 301  */
 302 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 303                               struct sctp_association *asoc,
 304                               struct dst_entry *dst,
 305                               union sctp_addr *daddr,
 306                               union sctp_addr *saddr)
 307 {
 308         struct sctp_bind_addr *bp;
 309         struct sctp_sockaddr_entry *laddr;
 310         sctp_scope_t scope;
 311         union sctp_addr *baddr = NULL;
 312         __u8 matchlen = 0;
 313         __u8 bmatchlen;
 314
 315         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
 316                           "daddr:" NIP6_FMT " ",
 317                           __func__, asoc, dst, NIP6(daddr->v6.sin6_addr));
 318
 319         if (!asoc) {
 320                 ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL,
 321                                    &daddr->v6.sin6_addr,
 322                                    inet6_sk(&sk->inet.sk)->srcprefs,
 323                                    &saddr->v6.sin6_addr);
 324                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
 325                                   NIP6(saddr->v6.sin6_addr));
 326                 return;
 327         }
 328
 329         scope = sctp_scope(daddr);
 330
 331         bp = &asoc->base.bind_addr;
 332
 333         /* Go through the bind address list and find the best source address
 334          * that matches the scope of the destination address.
 335          */
 336         rcu_read_lock();
 337         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 338                 if (!laddr->valid)
 339                         continue;
 340                 if ((laddr->state == SCTP_ADDR_SRC) &&
 341                     (laddr->a.sa.sa_family == AF_INET6) &&
 342                     (scope <= sctp_scope(&laddr->a))) {
 343                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 344                         if (!baddr || (matchlen < bmatchlen)) {
 345                                 baddr = &laddr->a;
 346                                 matchlen = bmatchlen;
 347                         }
 348                 }
 349         }
 350
 351         if (baddr) {
 352                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 353                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
 354                                   NIP6(saddr->v6.sin6_addr));
 355         } else {
 356                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 357                        "address for the dest:" NIP6_FMT "\n",
 358                        __func__, asoc, NIP6(daddr->v6.sin6_addr));
 359         }
 360
 361         rcu_read_unlock();
 362 }
 363
 364 /* Make a copy of all potential local addresses. */
 365 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 366                                   struct net_device *dev)
 367 {
 368         struct inet6_dev *in6_dev;
 369         struct inet6_ifaddr *ifp;
 370         struct sctp_sockaddr_entry *addr;
 371
 372         rcu_read_lock();
 373         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 374                 rcu_read_unlock();
 375                 return;
 376         }
 377
 378         read_lock_bh(&in6_dev->lock);
 379         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 380                 /* Add the address to the local list.  */
 381                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 382                 if (addr) {
 383                         addr->a.v6.sin6_family = AF_INET6;
 384                         addr->a.v6.sin6_port = 0;
 385                         addr->a.v6.sin6_addr = ifp->addr;
 386                         addr->a.v6.sin6_scope_id = dev->ifindex;
 387                         addr->valid = 1;
 388                         INIT_LIST_HEAD(&addr->list);
 389                         INIT_RCU_HEAD(&addr->rcu);
 390                         list_add_tail(&addr->list, addrlist);
 391                 }
 392         }
 393
 394         read_unlock_bh(&in6_dev->lock);
 395         rcu_read_unlock();
 396 }
 397
 398 /* Initialize a sockaddr_storage from in incoming skb. */
 399 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 400                              int is_saddr)
 401 {
 402         void *from;
 403         __be16 *port;
 404         struct sctphdr *sh;
 405
 406         port = &addr->v6.sin6_port;
 407         addr->v6.sin6_family = AF_INET6;
 408         addr->v6.sin6_flowinfo = 0; /* FIXME */
 409         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 410
 411         sh = sctp_hdr(skb);
 412         if (is_saddr) {
 413                 *port  = sh->source;
 414                 from = &ipv6_hdr(skb)->saddr;
 415         } else {
 416                 *port = sh->dest;
 417                 from = &ipv6_hdr(skb)->daddr;
 418         }
 419         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 420 }
 421
 422 /* Initialize an sctp_addr from a socket. */
 423 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 424 {
 425         addr->v6.sin6_family = AF_INET6;
 426         addr->v6.sin6_port = 0;
 427         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 428 }
 429
 430 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 431 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 432 {
 433         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 434                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 435                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 436                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 437                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 438                         addr->v4.sin_addr.s_addr;
 439         } else {
 440                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 441         }
 442 }
 443
 444 /* Initialize sk->sk_daddr from sctp_addr. */
 445 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 446 {
 447         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 448                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 449                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 450                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 451                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 452         } else {
 453                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 454         }
 455 }
 456
 457 /* Initialize a sctp_addr from an address parameter. */
 458 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 459                                     union sctp_addr_param *param,
 460                                     __be16 port, int iif)
 461 {
 462         addr->v6.sin6_family = AF_INET6;
 463         addr->v6.sin6_port = port;
 464         addr->v6.sin6_flowinfo = 0; /* BUG */
 465         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 466         addr->v6.sin6_scope_id = iif;
 467 }
 468
 469 /* Initialize an address parameter from a sctp_addr and return the length
 470  * of the address parameter.
 471  */
 472 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 473                                  union sctp_addr_param *param)
 474 {
 475         int length = sizeof(sctp_ipv6addr_param_t);
 476
 477         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 478         param->v6.param_hdr.length = htons(length);
 479         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 480
 481         return length;
 482 }
 483
 484 /* Initialize a sctp_addr from a dst_entry. */
 485 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 486                               __be16 port)
 487 {
 488         struct rt6_info *rt = (struct rt6_info *)dst;
 489         addr->sa.sa_family = AF_INET6;
 490         addr->v6.sin6_port = port;
 491         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 492 }
 493
 494 /* Compare addresses exactly.
 495  * v4-mapped-v6 is also in consideration.
 496  */
 497 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 498                             const union sctp_addr *addr2)
 499 {
 500         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 501                 if (addr1->sa.sa_family == AF_INET &&
 502                     addr2->sa.sa_family == AF_INET6 &&
 503                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 504                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 505                             addr2->v6.sin6_addr.s6_addr32[3] ==
 506                             addr1->v4.sin_addr.s_addr)
 507                                 return 1;
 508                 }
 509                 if (addr2->sa.sa_family == AF_INET &&
 510                     addr1->sa.sa_family == AF_INET6 &&
 511                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 512                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 513                             addr1->v6.sin6_addr.s6_addr32[3] ==
 514                             addr2->v4.sin_addr.s_addr)
 515                                 return 1;
 516                 }
 517                 return 0;
 518         }
 519         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 520                 return 0;
 521         /* If this is a linklocal address, compare the scope_id. */
 522         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 523                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 524                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 525                         return 0;
 526                 }
 527         }
 528
 529         return 1;
 530 }
 531
 532 /* Initialize addr struct to INADDR_ANY. */
 533 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 534 {
 535         memset(addr, 0x00, sizeof(union sctp_addr));
 536         addr->v6.sin6_family = AF_INET6;
 537         addr->v6.sin6_port = port;
 538 }
 539
 540 /* Is this a wildcard address? */
 541 static int sctp_v6_is_any(const union sctp_addr *addr)
 542 {
 543         return ipv6_addr_any(&addr->v6.sin6_addr);
 544 }
 545
 546 /* Should this be available for binding?   */
 547 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 548 {
 549         int type;
 550         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 551
 552         type = ipv6_addr_type(in6);
 553         if (IPV6_ADDR_ANY == type)
 554                 return 1;
 555         if (type == IPV6_ADDR_MAPPED) {
 556                 if (sp && !sp->v4mapped)
 557                         return 0;
 558                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 559                         return 0;
 560                 sctp_v6_map_v4(addr);
 561                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 562         }
 563         if (!(type & IPV6_ADDR_UNICAST))
 564                 return 0;
 565
 566         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 567 }
 568
 569 /* This function checks if the address is a valid address to be used for
 570  * SCTP.
 571  *
 572  * Output:
 573  * Return 0 - If the address is a non-unicast or an illegal address.
 574  * Return 1 - If the address is a unicast.
 575  */
 576 static int sctp_v6_addr_valid(union sctp_addr *addr,
 577                               struct sctp_sock *sp,
 578                               const struct sk_buff *skb)
 579 {
 580         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 581
 582         /* Support v4-mapped-v6 address. */
 583         if (ret == IPV6_ADDR_MAPPED) {
 584                 /* Note: This routine is used in input, so v4-mapped-v6
 585                  * are disallowed here when there is no sctp_sock.
 586                  */
 587                 if (!sp || !sp->v4mapped)
 588                         return 0;
 589                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 590                         return 0;
 591                 sctp_v6_map_v4(addr);
 592                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 593         }
 594
 595         /* Is this a non-unicast address */
 596         if (!(ret & IPV6_ADDR_UNICAST))
 597                 return 0;
 598
 599         return 1;
 600 }
 601
 602 /* What is the scope of 'addr'?  */
 603 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 604 {
 605         int v6scope;
 606         sctp_scope_t retval;
 607
 608         /* The IPv6 scope is really a set of bit fields.
 609          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 610          */
 611
 612         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 613         switch (v6scope) {
 614         case IFA_HOST:
 615                 retval = SCTP_SCOPE_LOOPBACK;
 616                 break;
 617         case IFA_LINK:
 618                 retval = SCTP_SCOPE_LINK;
 619                 break;
 620         case IFA_SITE:
 621                 retval = SCTP_SCOPE_PRIVATE;
 622                 break;
 623         default:
 624                 retval = SCTP_SCOPE_GLOBAL;
 625                 break;
 626         }
 627
 628         return retval;
 629 }
 630
 631 /* Create and initialize a new sk for the socket to be returned by accept(). */
 632 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 633                                              struct sctp_association *asoc)
 634 {
 635         struct inet_sock *inet = inet_sk(sk);
 636         struct sock *newsk;
 637         struct inet_sock *newinet;
 638         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 639         struct sctp6_sock *newsctp6sk;
 640
 641         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 642         if (!newsk)
 643                 goto out;
 644
 645         sock_init_data(NULL, newsk);
 646
 647         newsk->sk_type = SOCK_STREAM;
 648
 649         newsk->sk_prot = sk->sk_prot;
 650         newsk->sk_no_check = sk->sk_no_check;
 651         newsk->sk_reuse = sk->sk_reuse;
 652
 653         newsk->sk_destruct = inet_sock_destruct;
 654         newsk->sk_family = PF_INET6;
 655         newsk->sk_protocol = IPPROTO_SCTP;
 656         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 657         newsk->sk_shutdown = sk->sk_shutdown;
 658         sock_reset_flag(sk, SOCK_ZAPPED);
 659
 660         newsctp6sk = (struct sctp6_sock *)newsk;
 661         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 662
 663         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 664
 665         newinet = inet_sk(newsk);
 666         newnp = inet6_sk(newsk);
 667
 668         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 669
 670         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 671          * and getpeername().
 672          */
 673         newinet->sport = inet->sport;
 674         newnp->saddr = np->saddr;
 675         newnp->rcv_saddr = np->rcv_saddr;
 676         newinet->dport = htons(asoc->peer.port);
 677         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 678
 679         /* Init the ipv4 part of the socket since we can have sockets
 680          * using v6 API for ipv4.
 681          */
 682         newinet->uc_ttl = -1;
 683         newinet->mc_loop = 1;
 684         newinet->mc_ttl = 1;
 685         newinet->mc_index = 0;
 686         newinet->mc_list = NULL;
 687
 688         if (ipv4_config.no_pmtu_disc)
 689                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 690         else
 691                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 692
 693         sk_refcnt_debug_inc(newsk);
 694
 695         if (newsk->sk_prot->init(newsk)) {
 696                 sk_common_release(newsk);
 697                 newsk = NULL;
 698         }
 699
 700 out:
 701         return newsk;
 702 }
 703
 704 /* Map v4 address to mapped v6 address */
 705 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 706 {
 707         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 708                 sctp_v4_map_v6(addr);
 709 }
 710
 711 /* Where did this skb come from?  */
 712 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 713 {
 714         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 715         return opt->iif;
 716 }
 717
 718 /* Was this packet marked by Explicit Congestion Notification? */
 719 static int sctp_v6_is_ce(const struct sk_buff *skb)
 720 {
 721         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 722 }
 723
 724 /* Dump the v6 addr to the seq file. */
 725 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 726 {
 727         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
 728 }
 729
 730 static void sctp_v6_ecn_capable(struct sock *sk)
 731 {
 732         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 733 }
 734
 735 /* Initialize a PF_INET6 socket msg_name. */
 736 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 737 {
 738         struct sockaddr_in6 *sin6;
 739
 740         sin6 = (struct sockaddr_in6 *)msgname;
 741         sin6->sin6_family = AF_INET6;
 742         sin6->sin6_flowinfo = 0;
 743         sin6->sin6_scope_id = 0; /*FIXME */
 744         *addr_len = sizeof(struct sockaddr_in6);
 745 }
 746
 747 /* Initialize a PF_INET msgname from a ulpevent. */
 748 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 749                                      char *msgname, int *addrlen)
 750 {
 751         struct sockaddr_in6 *sin6, *sin6from;
 752
 753         if (msgname) {
 754                 union sctp_addr *addr;
 755                 struct sctp_association *asoc;
 756
 757                 asoc = event->asoc;
 758                 sctp_inet6_msgname(msgname, addrlen);
 759                 sin6 = (struct sockaddr_in6 *)msgname;
 760                 sin6->sin6_port = htons(asoc->peer.port);
 761                 addr = &asoc->peer.primary_addr;
 762
 763                 /* Note: If we go to a common v6 format, this code
 764                  * will change.
 765                  */
 766
 767                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 768                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 769                     AF_INET == addr->sa.sa_family) {
 770                         sctp_v4_map_v6((union sctp_addr *)sin6);
 771                         sin6->sin6_addr.s6_addr32[3] =
 772                                 addr->v4.sin_addr.s_addr;
 773                         return;
 774                 }
 775
 776                 sin6from = &asoc->peer.primary_addr.v6;
 777                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 778                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 779                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 780         }
 781 }
 782
 783 /* Initialize a msg_name from an inbound skb. */
 784 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 785                                    int *addr_len)
 786 {
 787         struct sctphdr *sh;
 788         struct sockaddr_in6 *sin6;
 789
 790         if (msgname) {
 791                 sctp_inet6_msgname(msgname, addr_len);
 792                 sin6 = (struct sockaddr_in6 *)msgname;
 793                 sh = sctp_hdr(skb);
 794                 sin6->sin6_port = sh->source;
 795
 796                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 797                 if (sctp_sk(skb->sk)->v4mapped &&
 798                     ip_hdr(skb)->version == 4) {
 799                         sctp_v4_map_v6((union sctp_addr *)sin6);
 800                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 801                         return;
 802                 }
 803
 804                 /* Otherwise, just copy the v6 address. */
 805                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 806                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 807                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 808                         sin6->sin6_scope_id = ev->iif;
 809                 }
 810         }
 811 }
 812
 813 /* Do we support this AF? */
 814 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 815 {
 816         switch (family) {
 817         case AF_INET6:
 818                 return 1;
 819         /* v4-mapped-v6 addresses */
 820         case AF_INET:
 821                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 822                         return 1;
 823         default:
 824                 return 0;
 825         }
 826 }
 827
 828 /* Address matching with wildcards allowed.  This extra level
 829  * of indirection lets us choose whether a PF_INET6 should
 830  * disallow any v4 addresses if we so choose.
 831  */
 832 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 833                                const union sctp_addr *addr2,
 834                                struct sctp_sock *opt)
 835 {
 836         struct sctp_af *af1, *af2;
 837
 838         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 839         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 840
 841         if (!af1 || !af2)
 842                 return 0;
 843
 844         /* If the socket is IPv6 only, v4 addrs will not match */
 845         if (__ipv6_only_sock(sctp_opt2sk(opt)) && af1 != af2)
 846                 return 0;
 847
 848         /* Today, wildcard AF_INET/AF_INET6. */
 849         if (sctp_is_any(addr1) || sctp_is_any(addr2))
 850                 return 1;
 851
 852         if (addr1->sa.sa_family != addr2->sa.sa_family)
 853                 return 0;
 854
 855         return af1->cmp_addr(addr1, addr2);
 856 }
 857
 858 /* Verify that the provided sockaddr looks bindable.   Common verification,
 859  * has already been taken care of.
 860  */
 861 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 862 {
 863         struct sctp_af *af;
 864
 865         /* ASSERT: address family has already been verified. */
 866         if (addr->sa.sa_family != AF_INET6)
 867                 af = sctp_get_af_specific(addr->sa.sa_family);
 868         else {
 869                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 870                 struct net_device *dev;
 871
 872                 if (type & IPV6_ADDR_LINKLOCAL) {
 873                         if (!addr->v6.sin6_scope_id)
 874                                 return 0;
 875                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 876                         if (!dev)
 877                                 return 0;
 878                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 879                                            dev, 0)) {
 880                                 dev_put(dev);
 881                                 return 0;
 882                         }
 883                         dev_put(dev);
 884                 } else if (type == IPV6_ADDR_MAPPED) {
 885                         if (!opt->v4mapped)
 886                                 return 0;
 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                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 912                         if (!dev)
 913                                 return 0;
 914                         dev_put(dev);
 915                 }
 916                 af = opt->pf->af;
 917         }
 918
 919         return af != NULL;
 920 }
 921
 922 /* Fill in Supported Address Type information for INIT and INIT-ACK
 923  * chunks.   Note: In the future, we may want to look at sock options
 924  * to determine whether a PF_INET6 socket really wants to have IPV4
 925  * addresses.
 926  * Returns number of addresses supported.
 927  */
 928 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 929                                       __be16 *types)
 930 {
 931         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 932         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 933                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 934                 return 2;
 935         }
 936         return 1;
 937 }
 938
 939 static const struct proto_ops inet6_seqpacket_ops = {
 940         .family            = PF_INET6,
 941         .owner             = THIS_MODULE,
 942         .release           = inet6_release,
 943         .bind              = inet6_bind,
 944         .connect           = inet_dgram_connect,
 945         .socketpair        = sock_no_socketpair,
 946         .accept            = inet_accept,
 947         .getname           = inet6_getname,
 948         .poll              = sctp_poll,
 949         .ioctl             = inet6_ioctl,
 950         .listen            = sctp_inet_listen,
 951         .shutdown          = inet_shutdown,
 952         .setsockopt        = sock_common_setsockopt,
 953         .getsockopt        = sock_common_getsockopt,
 954         .sendmsg           = inet_sendmsg,
 955         .recvmsg           = sock_common_recvmsg,
 956         .mmap              = sock_no_mmap,
 957 #ifdef CONFIG_COMPAT
 958         .compat_setsockopt = compat_sock_common_setsockopt,
 959         .compat_getsockopt = compat_sock_common_getsockopt,
 960 #endif
 961 };
 962
 963 static struct inet_protosw sctpv6_seqpacket_protosw = {
 964         .type          = SOCK_SEQPACKET,
 965         .protocol      = IPPROTO_SCTP,
 966         .prot          = &sctpv6_prot,
 967         .ops           = &inet6_seqpacket_ops,
 968         .capability    = -1,
 969         .no_check      = 0,
 970         .flags         = SCTP_PROTOSW_FLAG
 971 };
 972 static struct inet_protosw sctpv6_stream_protosw = {
 973         .type          = SOCK_STREAM,
 974         .protocol      = IPPROTO_SCTP,
 975         .prot          = &sctpv6_prot,
 976         .ops           = &inet6_seqpacket_ops,
 977         .capability    = -1,
 978         .no_check      = 0,
 979         .flags         = SCTP_PROTOSW_FLAG,
 980 };
 981
 982 static int sctp6_rcv(struct sk_buff *skb)
 983 {
 984         return sctp_rcv(skb) ? -1 : 0;
 985 }
 986
 987 static struct inet6_protocol sctpv6_protocol = {
 988         .handler      = sctp6_rcv,
 989         .err_handler  = sctp_v6_err,
 990         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 991 };
 992
 993 static struct sctp_af sctp_af_inet6 = {
 994         .sa_family         = AF_INET6,
 995         .sctp_xmit         = sctp_v6_xmit,
 996         .setsockopt        = ipv6_setsockopt,
 997         .getsockopt        = ipv6_getsockopt,
 998         .get_dst           = sctp_v6_get_dst,
 999         .get_saddr         = sctp_v6_get_saddr,
1000         .copy_addrlist     = sctp_v6_copy_addrlist,
1001         .from_skb          = sctp_v6_from_skb,
1002         .from_sk           = sctp_v6_from_sk,
1003         .to_sk_saddr       = sctp_v6_to_sk_saddr,
1004         .to_sk_daddr       = sctp_v6_to_sk_daddr,
1005         .from_addr_param   = sctp_v6_from_addr_param,
1006         .to_addr_param     = sctp_v6_to_addr_param,
1007         .dst_saddr         = sctp_v6_dst_saddr,
1008         .cmp_addr          = sctp_v6_cmp_addr,
1009         .scope             = sctp_v6_scope,
1010         .addr_valid        = sctp_v6_addr_valid,
1011         .inaddr_any        = sctp_v6_inaddr_any,
1012         .is_any            = sctp_v6_is_any,
1013         .available         = sctp_v6_available,
1014         .skb_iif           = sctp_v6_skb_iif,
1015         .is_ce             = sctp_v6_is_ce,
1016         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1017         .ecn_capable       = sctp_v6_ecn_capable,
1018         .net_header_len    = sizeof(struct ipv6hdr),
1019         .sockaddr_len      = sizeof(struct sockaddr_in6),
1020 #ifdef CONFIG_COMPAT
1021         .compat_setsockopt = compat_ipv6_setsockopt,
1022         .compat_getsockopt = compat_ipv6_getsockopt,
1023 #endif
1024 };
1025
1026 static struct sctp_pf sctp_pf_inet6 = {
1027         .event_msgname = sctp_inet6_event_msgname,
1028         .skb_msgname   = sctp_inet6_skb_msgname,
1029         .af_supported  = sctp_inet6_af_supported,
1030         .cmp_addr      = sctp_inet6_cmp_addr,
1031         .bind_verify   = sctp_inet6_bind_verify,
1032         .send_verify   = sctp_inet6_send_verify,
1033         .supported_addrs = sctp_inet6_supported_addrs,
1034         .create_accept_sk = sctp_v6_create_accept_sk,
1035         .addr_v4map    = sctp_v6_addr_v4map,
1036         .af            = &sctp_af_inet6,
1037 };
1038
1039 /* Initialize IPv6 support and register with socket layer.  */
1040 void sctp_v6_pf_init(void)
1041 {
1042         /* Register the SCTP specific PF_INET6 functions. */
1043         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1044
1045         /* Register the SCTP specific AF_INET6 functions. */
1046         sctp_register_af(&sctp_af_inet6);
1047 }
1048
1049 void sctp_v6_pf_exit(void)
1050 {
1051         list_del(&sctp_af_inet6.list);
1052 }
1053
1054 /* Initialize IPv6 support and register with socket layer.  */
1055 int sctp_v6_protosw_init(void)
1056 {
1057         int rc;
1058
1059         rc = proto_register(&sctpv6_prot, 1);
1060         if (rc)
1061                 return rc;
1062
1063         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1064         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1065         inet6_register_protosw(&sctpv6_stream_protosw);
1066
1067         return 0;
1068 }
1069
1070 void sctp_v6_protosw_exit(void)
1071 {
1072         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1073         inet6_unregister_protosw(&sctpv6_stream_protosw);
1074         proto_unregister(&sctpv6_prot);
1075 }
1076
1077
1078 /* Register with inet6 layer. */
1079 int sctp_v6_add_protocol(void)
1080 {
1081         /* Register notifier for inet6 address additions/deletions. */
1082         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1083
1084         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1085                 return -EAGAIN;
1086
1087         return 0;
1088 }
1089
1090 /* Unregister with inet6 layer. */
1091 void sctp_v6_del_protocol(void)
1092 {
1093         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1094         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1095 }