net/sctp/ipv6.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2002, 2004
   3  * Copyright (c) 2001 Nokia, Inc.
   4  * Copyright (c) 2001 La Monte H.P. Yarroll
   5  * Copyright (c) 2002-2003 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * This SCTP implementation is free software;
  12  * you can redistribute it and/or modify it under the terms of
  13  * the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This SCTP implementation is distributed in the hope that it
  18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19  *                 ************************
  20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21  * See the GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with GNU CC; see the file COPYING.  If not, 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 {
 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         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 234                 skb->local_df = 1;
 235
 236         return ip6_xmit(sk, skb, &fl, np->opt, 0);
 237 }
 238
 239 /* Returns the dst cache entry for the given source and destination ip
 240  * addresses.
 241  */
 242 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 243                                          union sctp_addr *daddr,
 244                                          union sctp_addr *saddr)
 245 {
 246         struct dst_entry *dst;
 247         struct flowi fl;
 248
 249         memset(&fl, 0, sizeof(fl));
 250         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 251         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 252                 fl.oif = daddr->v6.sin6_scope_id;
 253
 254
 255         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
 256                           __func__, NIP6(fl.fl6_dst));
 257
 258         if (saddr) {
 259                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 260                 SCTP_DEBUG_PRINTK(
 261                         "SRC=" NIP6_FMT " - ",
 262                         NIP6(fl.fl6_src));
 263         }
 264
 265         dst = ip6_route_output(&init_net, NULL, &fl);
 266         if (!dst->error) {
 267                 struct rt6_info *rt;
 268                 rt = (struct rt6_info *)dst;
 269                 SCTP_DEBUG_PRINTK(
 270                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
 271                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
 272                 return dst;
 273         }
 274         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 275         dst_release(dst);
 276         return NULL;
 277 }
 278
 279 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 280  * addresses.
 281  */
 282 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 283                                          union sctp_addr *s2)
 284 {
 285         struct in6_addr *a1 = &s1->v6.sin6_addr;
 286         struct in6_addr *a2 = &s2->v6.sin6_addr;
 287         int i, j;
 288
 289         for (i = 0; i < 4 ; i++) {
 290                 __be32 a1xora2;
 291
 292                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 293
 294                 if ((j = fls(ntohl(a1xora2))))
 295                         return (i * 32 + 32 - j);
 296         }
 297
 298         return (i*32);
 299 }
 300
 301 /* Fills in the source address(saddr) based on the destination address(daddr)
 302  * and asoc's bind address list.
 303  */
 304 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 305                               struct sctp_association *asoc,
 306                               struct dst_entry *dst,
 307                               union sctp_addr *daddr,
 308                               union sctp_addr *saddr)
 309 {
 310         struct sctp_bind_addr *bp;
 311         struct sctp_sockaddr_entry *laddr;
 312         sctp_scope_t scope;
 313         union sctp_addr *baddr = NULL;
 314         __u8 matchlen = 0;
 315         __u8 bmatchlen;
 316
 317         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
 318                           "daddr:" NIP6_FMT " ",
 319                           __func__, asoc, dst, NIP6(daddr->v6.sin6_addr));
 320
 321         if (!asoc) {
 322                 ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL,
 323                                    &daddr->v6.sin6_addr,
 324                                    inet6_sk(&sk->inet.sk)->srcprefs,
 325                                    &saddr->v6.sin6_addr);
 326                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
 327                                   NIP6(saddr->v6.sin6_addr));
 328                 return;
 329         }
 330
 331         scope = sctp_scope(daddr);
 332
 333         bp = &asoc->base.bind_addr;
 334
 335         /* Go through the bind address list and find the best source address
 336          * that matches the scope of the destination address.
 337          */
 338         rcu_read_lock();
 339         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 340                 if (!laddr->valid)
 341                         continue;
 342                 if ((laddr->state == SCTP_ADDR_SRC) &&
 343                     (laddr->a.sa.sa_family == AF_INET6) &&
 344                     (scope <= sctp_scope(&laddr->a))) {
 345                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 346                         if (!baddr || (matchlen < bmatchlen)) {
 347                                 baddr = &laddr->a;
 348                                 matchlen = bmatchlen;
 349                         }
 350                 }
 351         }
 352
 353         if (baddr) {
 354                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 355                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
 356                                   NIP6(saddr->v6.sin6_addr));
 357         } else {
 358                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 359                        "address for the dest:" NIP6_FMT "\n",
 360                        __func__, asoc, NIP6(daddr->v6.sin6_addr));
 361         }
 362
 363         rcu_read_unlock();
 364 }
 365
 366 /* Make a copy of all potential local addresses. */
 367 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 368                                   struct net_device *dev)
 369 {
 370         struct inet6_dev *in6_dev;
 371         struct inet6_ifaddr *ifp;
 372         struct sctp_sockaddr_entry *addr;
 373
 374         rcu_read_lock();
 375         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 376                 rcu_read_unlock();
 377                 return;
 378         }
 379
 380         read_lock_bh(&in6_dev->lock);
 381         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 382                 /* Add the address to the local list.  */
 383                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 384                 if (addr) {
 385                         addr->a.v6.sin6_family = AF_INET6;
 386                         addr->a.v6.sin6_port = 0;
 387                         addr->a.v6.sin6_addr = ifp->addr;
 388                         addr->a.v6.sin6_scope_id = dev->ifindex;
 389                         addr->valid = 1;
 390                         INIT_LIST_HEAD(&addr->list);
 391                         INIT_RCU_HEAD(&addr->rcu);
 392                         list_add_tail(&addr->list, addrlist);
 393                 }
 394         }
 395
 396         read_unlock_bh(&in6_dev->lock);
 397         rcu_read_unlock();
 398 }
 399
 400 /* Initialize a sockaddr_storage from in incoming skb. */
 401 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 402                              int is_saddr)
 403 {
 404         void *from;
 405         __be16 *port;
 406         struct sctphdr *sh;
 407
 408         port = &addr->v6.sin6_port;
 409         addr->v6.sin6_family = AF_INET6;
 410         addr->v6.sin6_flowinfo = 0; /* FIXME */
 411         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 412
 413         sh = sctp_hdr(skb);
 414         if (is_saddr) {
 415                 *port  = sh->source;
 416                 from = &ipv6_hdr(skb)->saddr;
 417         } else {
 418                 *port = sh->dest;
 419                 from = &ipv6_hdr(skb)->daddr;
 420         }
 421         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 422 }
 423
 424 /* Initialize an sctp_addr from a socket. */
 425 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 426 {
 427         addr->v6.sin6_family = AF_INET6;
 428         addr->v6.sin6_port = 0;
 429         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 430 }
 431
 432 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 433 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 434 {
 435         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 436                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 437                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 438                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 439                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 440                         addr->v4.sin_addr.s_addr;
 441         } else {
 442                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 443         }
 444 }
 445
 446 /* Initialize sk->sk_daddr from sctp_addr. */
 447 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 448 {
 449         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 450                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 451                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 452                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 453                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 454         } else {
 455                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 456         }
 457 }
 458
 459 /* Initialize a sctp_addr from an address parameter. */
 460 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 461                                     union sctp_addr_param *param,
 462                                     __be16 port, int iif)
 463 {
 464         addr->v6.sin6_family = AF_INET6;
 465         addr->v6.sin6_port = port;
 466         addr->v6.sin6_flowinfo = 0; /* BUG */
 467         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 468         addr->v6.sin6_scope_id = iif;
 469 }
 470
 471 /* Initialize an address parameter from a sctp_addr and return the length
 472  * of the address parameter.
 473  */
 474 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 475                                  union sctp_addr_param *param)
 476 {
 477         int length = sizeof(sctp_ipv6addr_param_t);
 478
 479         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 480         param->v6.param_hdr.length = htons(length);
 481         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 482
 483         return length;
 484 }
 485
 486 /* Initialize a sctp_addr from a dst_entry. */
 487 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 488                               __be16 port)
 489 {
 490         struct rt6_info *rt = (struct rt6_info *)dst;
 491         addr->sa.sa_family = AF_INET6;
 492         addr->v6.sin6_port = port;
 493         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 494 }
 495
 496 /* Compare addresses exactly.
 497  * v4-mapped-v6 is also in consideration.
 498  */
 499 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 500                             const union sctp_addr *addr2)
 501 {
 502         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 503                 if (addr1->sa.sa_family == AF_INET &&
 504                     addr2->sa.sa_family == AF_INET6 &&
 505                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 506                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 507                             addr2->v6.sin6_addr.s6_addr32[3] ==
 508                             addr1->v4.sin_addr.s_addr)
 509                                 return 1;
 510                 }
 511                 if (addr2->sa.sa_family == AF_INET &&
 512                     addr1->sa.sa_family == AF_INET6 &&
 513                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 514                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 515                             addr1->v6.sin6_addr.s6_addr32[3] ==
 516                             addr2->v4.sin_addr.s_addr)
 517                                 return 1;
 518                 }
 519                 return 0;
 520         }
 521         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 522                 return 0;
 523         /* If this is a linklocal address, compare the scope_id. */
 524         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 525                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 526                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 527                         return 0;
 528                 }
 529         }
 530
 531         return 1;
 532 }
 533
 534 /* Initialize addr struct to INADDR_ANY. */
 535 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 536 {
 537         memset(addr, 0x00, sizeof(union sctp_addr));
 538         addr->v6.sin6_family = AF_INET6;
 539         addr->v6.sin6_port = port;
 540 }
 541
 542 /* Is this a wildcard address? */
 543 static int sctp_v6_is_any(const union sctp_addr *addr)
 544 {
 545         return ipv6_addr_any(&addr->v6.sin6_addr);
 546 }
 547
 548 /* Should this be available for binding?   */
 549 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 550 {
 551         int type;
 552         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 553
 554         type = ipv6_addr_type(in6);
 555         if (IPV6_ADDR_ANY == type)
 556                 return 1;
 557         if (type == IPV6_ADDR_MAPPED) {
 558                 if (sp && !sp->v4mapped)
 559                         return 0;
 560                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 561                         return 0;
 562                 sctp_v6_map_v4(addr);
 563                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 564         }
 565         if (!(type & IPV6_ADDR_UNICAST))
 566                 return 0;
 567
 568         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 569 }
 570
 571 /* This function checks if the address is a valid address to be used for
 572  * SCTP.
 573  *
 574  * Output:
 575  * Return 0 - If the address is a non-unicast or an illegal address.
 576  * Return 1 - If the address is a unicast.
 577  */
 578 static int sctp_v6_addr_valid(union sctp_addr *addr,
 579                               struct sctp_sock *sp,
 580                               const struct sk_buff *skb)
 581 {
 582         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 583
 584         /* Support v4-mapped-v6 address. */
 585         if (ret == IPV6_ADDR_MAPPED) {
 586                 /* Note: This routine is used in input, so v4-mapped-v6
 587                  * are disallowed here when there is no sctp_sock.
 588                  */
 589                 if (!sp || !sp->v4mapped)
 590                         return 0;
 591                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 592                         return 0;
 593                 sctp_v6_map_v4(addr);
 594                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 595         }
 596
 597         /* Is this a non-unicast address */
 598         if (!(ret & IPV6_ADDR_UNICAST))
 599                 return 0;
 600
 601         return 1;
 602 }
 603
 604 /* What is the scope of 'addr'?  */
 605 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 606 {
 607         int v6scope;
 608         sctp_scope_t retval;
 609
 610         /* The IPv6 scope is really a set of bit fields.
 611          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 612          */
 613
 614         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 615         switch (v6scope) {
 616         case IFA_HOST:
 617                 retval = SCTP_SCOPE_LOOPBACK;
 618                 break;
 619         case IFA_LINK:
 620                 retval = SCTP_SCOPE_LINK;
 621                 break;
 622         case IFA_SITE:
 623                 retval = SCTP_SCOPE_PRIVATE;
 624                 break;
 625         default:
 626                 retval = SCTP_SCOPE_GLOBAL;
 627                 break;
 628         }
 629
 630         return retval;
 631 }
 632
 633 /* Create and initialize a new sk for the socket to be returned by accept(). */
 634 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 635                                              struct sctp_association *asoc)
 636 {
 637         struct inet_sock *inet = inet_sk(sk);
 638         struct sock *newsk;
 639         struct inet_sock *newinet;
 640         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 641         struct sctp6_sock *newsctp6sk;
 642
 643         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 644         if (!newsk)
 645                 goto out;
 646
 647         sock_init_data(NULL, newsk);
 648
 649         newsk->sk_type = SOCK_STREAM;
 650
 651         newsk->sk_prot = sk->sk_prot;
 652         newsk->sk_no_check = sk->sk_no_check;
 653         newsk->sk_reuse = sk->sk_reuse;
 654
 655         newsk->sk_destruct = inet_sock_destruct;
 656         newsk->sk_family = PF_INET6;
 657         newsk->sk_protocol = IPPROTO_SCTP;
 658         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 659         newsk->sk_shutdown = sk->sk_shutdown;
 660         sock_reset_flag(sk, SOCK_ZAPPED);
 661
 662         newsctp6sk = (struct sctp6_sock *)newsk;
 663         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 664
 665         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 666
 667         newinet = inet_sk(newsk);
 668         newnp = inet6_sk(newsk);
 669
 670         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 671
 672         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 673          * and getpeername().
 674          */
 675         newinet->sport = inet->sport;
 676         newnp->saddr = np->saddr;
 677         newnp->rcv_saddr = np->rcv_saddr;
 678         newinet->dport = htons(asoc->peer.port);
 679         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 680
 681         /* Init the ipv4 part of the socket since we can have sockets
 682          * using v6 API for ipv4.
 683          */
 684         newinet->uc_ttl = -1;
 685         newinet->mc_loop = 1;
 686         newinet->mc_ttl = 1;
 687         newinet->mc_index = 0;
 688         newinet->mc_list = NULL;
 689
 690         if (ipv4_config.no_pmtu_disc)
 691                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 692         else
 693                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 694
 695         sk_refcnt_debug_inc(newsk);
 696
 697         if (newsk->sk_prot->init(newsk)) {
 698                 sk_common_release(newsk);
 699                 newsk = NULL;
 700         }
 701
 702 out:
 703         return newsk;
 704 }
 705
 706 /* Map v4 address to mapped v6 address */
 707 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 708 {
 709         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 710                 sctp_v4_map_v6(addr);
 711 }
 712
 713 /* Where did this skb come from?  */
 714 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 715 {
 716         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 717         return opt->iif;
 718 }
 719
 720 /* Was this packet marked by Explicit Congestion Notification? */
 721 static int sctp_v6_is_ce(const struct sk_buff *skb)
 722 {
 723         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 724 }
 725
 726 /* Dump the v6 addr to the seq file. */
 727 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 728 {
 729         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
 730 }
 731
 732 static void sctp_v6_ecn_capable(struct sock *sk)
 733 {
 734         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 735 }
 736
 737 /* Initialize a PF_INET6 socket msg_name. */
 738 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 739 {
 740         struct sockaddr_in6 *sin6;
 741
 742         sin6 = (struct sockaddr_in6 *)msgname;
 743         sin6->sin6_family = AF_INET6;
 744         sin6->sin6_flowinfo = 0;
 745         sin6->sin6_scope_id = 0; /*FIXME */
 746         *addr_len = sizeof(struct sockaddr_in6);
 747 }
 748
 749 /* Initialize a PF_INET msgname from a ulpevent. */
 750 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 751                                      char *msgname, int *addrlen)
 752 {
 753         struct sockaddr_in6 *sin6, *sin6from;
 754
 755         if (msgname) {
 756                 union sctp_addr *addr;
 757                 struct sctp_association *asoc;
 758
 759                 asoc = event->asoc;
 760                 sctp_inet6_msgname(msgname, addrlen);
 761                 sin6 = (struct sockaddr_in6 *)msgname;
 762                 sin6->sin6_port = htons(asoc->peer.port);
 763                 addr = &asoc->peer.primary_addr;
 764
 765                 /* Note: If we go to a common v6 format, this code
 766                  * will change.
 767                  */
 768
 769                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 770                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 771                     AF_INET == addr->sa.sa_family) {
 772                         sctp_v4_map_v6((union sctp_addr *)sin6);
 773                         sin6->sin6_addr.s6_addr32[3] =
 774                                 addr->v4.sin_addr.s_addr;
 775                         return;
 776                 }
 777
 778                 sin6from = &asoc->peer.primary_addr.v6;
 779                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 780                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 781                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 782         }
 783 }
 784
 785 /* Initialize a msg_name from an inbound skb. */
 786 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 787                                    int *addr_len)
 788 {
 789         struct sctphdr *sh;
 790         struct sockaddr_in6 *sin6;
 791
 792         if (msgname) {
 793                 sctp_inet6_msgname(msgname, addr_len);
 794                 sin6 = (struct sockaddr_in6 *)msgname;
 795                 sh = sctp_hdr(skb);
 796                 sin6->sin6_port = sh->source;
 797
 798                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 799                 if (sctp_sk(skb->sk)->v4mapped &&
 800                     ip_hdr(skb)->version == 4) {
 801                         sctp_v4_map_v6((union sctp_addr *)sin6);
 802                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 803                         return;
 804                 }
 805
 806                 /* Otherwise, just copy the v6 address. */
 807                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 808                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 809                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 810                         sin6->sin6_scope_id = ev->iif;
 811                 }
 812         }
 813 }
 814
 815 /* Do we support this AF? */
 816 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 817 {
 818         switch (family) {
 819         case AF_INET6:
 820                 return 1;
 821         /* v4-mapped-v6 addresses */
 822         case AF_INET:
 823                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 824                         return 1;
 825         default:
 826                 return 0;
 827         }
 828 }
 829
 830 /* Address matching with wildcards allowed.  This extra level
 831  * of indirection lets us choose whether a PF_INET6 should
 832  * disallow any v4 addresses if we so choose.
 833  */
 834 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 835                                const union sctp_addr *addr2,
 836                                struct sctp_sock *opt)
 837 {
 838         struct sctp_af *af1, *af2;
 839
 840         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 841         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 842
 843         if (!af1 || !af2)
 844                 return 0;
 845
 846         /* If the socket is IPv6 only, v4 addrs will not match */
 847         if (__ipv6_only_sock(sctp_opt2sk(opt)) && af1 != af2)
 848                 return 0;
 849
 850         /* Today, wildcard AF_INET/AF_INET6. */
 851         if (sctp_is_any(addr1) || sctp_is_any(addr2))
 852                 return 1;
 853
 854         if (addr1->sa.sa_family != addr2->sa.sa_family)
 855                 return 0;
 856
 857         return af1->cmp_addr(addr1, addr2);
 858 }
 859
 860 /* Verify that the provided sockaddr looks bindable.   Common verification,
 861  * has already been taken care of.
 862  */
 863 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 864 {
 865         struct sctp_af *af;
 866
 867         /* ASSERT: address family has already been verified. */
 868         if (addr->sa.sa_family != AF_INET6)
 869                 af = sctp_get_af_specific(addr->sa.sa_family);
 870         else {
 871                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 872                 struct net_device *dev;
 873
 874                 if (type & IPV6_ADDR_LINKLOCAL) {
 875                         if (!addr->v6.sin6_scope_id)
 876                                 return 0;
 877                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 878                         if (!dev)
 879                                 return 0;
 880                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 881                                            dev, 0)) {
 882                                 dev_put(dev);
 883                                 return 0;
 884                         }
 885                         dev_put(dev);
 886                 } else if (type == IPV6_ADDR_MAPPED) {
 887                         if (!opt->v4mapped)
 888                                 return 0;
 889                 }
 890
 891                 af = opt->pf->af;
 892         }
 893         return af->available(addr, opt);
 894 }
 895
 896 /* Verify that the provided sockaddr looks sendable.   Common verification,
 897  * has already been taken care of.
 898  */
 899 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 900 {
 901         struct sctp_af *af = NULL;
 902
 903         /* ASSERT: address family has already been verified. */
 904         if (addr->sa.sa_family != AF_INET6)
 905                 af = sctp_get_af_specific(addr->sa.sa_family);
 906         else {
 907                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 908                 struct net_device *dev;
 909
 910                 if (type & IPV6_ADDR_LINKLOCAL) {
 911                         if (!addr->v6.sin6_scope_id)
 912                                 return 0;
 913                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 914                         if (!dev)
 915                                 return 0;
 916                         dev_put(dev);
 917                 }
 918                 af = opt->pf->af;
 919         }
 920
 921         return af != NULL;
 922 }
 923
 924 /* Fill in Supported Address Type information for INIT and INIT-ACK
 925  * chunks.   Note: In the future, we may want to look at sock options
 926  * to determine whether a PF_INET6 socket really wants to have IPV4
 927  * addresses.
 928  * Returns number of addresses supported.
 929  */
 930 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 931                                       __be16 *types)
 932 {
 933         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 934         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 935                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 936                 return 2;
 937         }
 938         return 1;
 939 }
 940
 941 static const struct proto_ops inet6_seqpacket_ops = {
 942         .family            = PF_INET6,
 943         .owner             = THIS_MODULE,
 944         .release           = inet6_release,
 945         .bind              = inet6_bind,
 946         .connect           = inet_dgram_connect,
 947         .socketpair        = sock_no_socketpair,
 948         .accept            = inet_accept,
 949         .getname           = inet6_getname,
 950         .poll              = sctp_poll,
 951         .ioctl             = inet6_ioctl,
 952         .listen            = sctp_inet_listen,
 953         .shutdown          = inet_shutdown,
 954         .setsockopt        = sock_common_setsockopt,
 955         .getsockopt        = sock_common_getsockopt,
 956         .sendmsg           = inet_sendmsg,
 957         .recvmsg           = sock_common_recvmsg,
 958         .mmap              = sock_no_mmap,
 959 #ifdef CONFIG_COMPAT
 960         .compat_setsockopt = compat_sock_common_setsockopt,
 961         .compat_getsockopt = compat_sock_common_getsockopt,
 962 #endif
 963 };
 964
 965 static struct inet_protosw sctpv6_seqpacket_protosw = {
 966         .type          = SOCK_SEQPACKET,
 967         .protocol      = IPPROTO_SCTP,
 968         .prot          = &sctpv6_prot,
 969         .ops           = &inet6_seqpacket_ops,
 970         .capability    = -1,
 971         .no_check      = 0,
 972         .flags         = SCTP_PROTOSW_FLAG
 973 };
 974 static struct inet_protosw sctpv6_stream_protosw = {
 975         .type          = SOCK_STREAM,
 976         .protocol      = IPPROTO_SCTP,
 977         .prot          = &sctpv6_prot,
 978         .ops           = &inet6_seqpacket_ops,
 979         .capability    = -1,
 980         .no_check      = 0,
 981         .flags         = SCTP_PROTOSW_FLAG,
 982 };
 983
 984 static int sctp6_rcv(struct sk_buff *skb)
 985 {
 986         return sctp_rcv(skb) ? -1 : 0;
 987 }
 988
 989 static struct inet6_protocol sctpv6_protocol = {
 990         .handler      = sctp6_rcv,
 991         .err_handler  = sctp_v6_err,
 992         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 993 };
 994
 995 static struct sctp_af sctp_af_inet6 = {
 996         .sa_family         = AF_INET6,
 997         .sctp_xmit         = sctp_v6_xmit,
 998         .setsockopt        = ipv6_setsockopt,
 999         .getsockopt        = ipv6_getsockopt,
1000         .get_dst           = sctp_v6_get_dst,
1001         .get_saddr         = sctp_v6_get_saddr,
1002         .copy_addrlist     = sctp_v6_copy_addrlist,
1003         .from_skb          = sctp_v6_from_skb,
1004         .from_sk           = sctp_v6_from_sk,
1005         .to_sk_saddr       = sctp_v6_to_sk_saddr,
1006         .to_sk_daddr       = sctp_v6_to_sk_daddr,
1007         .from_addr_param   = sctp_v6_from_addr_param,
1008         .to_addr_param     = sctp_v6_to_addr_param,
1009         .dst_saddr         = sctp_v6_dst_saddr,
1010         .cmp_addr          = sctp_v6_cmp_addr,
1011         .scope             = sctp_v6_scope,
1012         .addr_valid        = sctp_v6_addr_valid,
1013         .inaddr_any        = sctp_v6_inaddr_any,
1014         .is_any            = sctp_v6_is_any,
1015         .available         = sctp_v6_available,
1016         .skb_iif           = sctp_v6_skb_iif,
1017         .is_ce             = sctp_v6_is_ce,
1018         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1019         .ecn_capable       = sctp_v6_ecn_capable,
1020         .net_header_len    = sizeof(struct ipv6hdr),
1021         .sockaddr_len      = sizeof(struct sockaddr_in6),
1022 #ifdef CONFIG_COMPAT
1023         .compat_setsockopt = compat_ipv6_setsockopt,
1024         .compat_getsockopt = compat_ipv6_getsockopt,
1025 #endif
1026 };
1027
1028 static struct sctp_pf sctp_pf_inet6 = {
1029         .event_msgname = sctp_inet6_event_msgname,
1030         .skb_msgname   = sctp_inet6_skb_msgname,
1031         .af_supported  = sctp_inet6_af_supported,
1032         .cmp_addr      = sctp_inet6_cmp_addr,
1033         .bind_verify   = sctp_inet6_bind_verify,
1034         .send_verify   = sctp_inet6_send_verify,
1035         .supported_addrs = sctp_inet6_supported_addrs,
1036         .create_accept_sk = sctp_v6_create_accept_sk,
1037         .addr_v4map    = sctp_v6_addr_v4map,
1038         .af            = &sctp_af_inet6,
1039 };
1040
1041 /* Initialize IPv6 support and register with socket layer.  */
1042 void sctp_v6_pf_init(void)
1043 {
1044         /* Register the SCTP specific PF_INET6 functions. */
1045         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1046
1047         /* Register the SCTP specific AF_INET6 functions. */
1048         sctp_register_af(&sctp_af_inet6);
1049 }
1050
1051 void sctp_v6_pf_exit(void)
1052 {
1053         list_del(&sctp_af_inet6.list);
1054 }
1055
1056 /* Initialize IPv6 support and register with socket layer.  */
1057 int sctp_v6_protosw_init(void)
1058 {
1059         int rc;
1060
1061         rc = proto_register(&sctpv6_prot, 1);
1062         if (rc)
1063                 return rc;
1064
1065         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1066         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1067         inet6_register_protosw(&sctpv6_stream_protosw);
1068
1069         return 0;
1070 }
1071
1072 void sctp_v6_protosw_exit(void)
1073 {
1074         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1075         inet6_unregister_protosw(&sctpv6_stream_protosw);
1076         proto_unregister(&sctpv6_prot);
1077 }
1078
1079
1080 /* Register with inet6 layer. */
1081 int sctp_v6_add_protocol(void)
1082 {
1083         /* Register notifier for inet6 address additions/deletions. */
1084         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1085
1086         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1087                 return -EAGAIN;
1088
1089         return 0;
1090 }
1091
1092 /* Unregister with inet6 layer. */
1093 void sctp_v6_del_protocol(void)
1094 {
1095         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1096         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1097 }