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   1 /* SCTP kernel reference 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 reference Implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * The SCTP reference 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  * The SCTP reference 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/sched.h>
  57 #include <linux/in.h>
  58 #include <linux/in6.h>
  59 #include <linux/netdevice.h>
  60 #include <linux/init.h>
  61 #include <linux/ipsec.h>
  62
  63 #include <linux/ipv6.h>
  64 #include <linux/icmpv6.h>
  65 #include <linux/random.h>
  66 #include <linux/seq_file.h>
  67
  68 #include <net/protocol.h>
  69 #include <net/ndisc.h>
  70 #include <net/ip.h>
  71 #include <net/ipv6.h>
  72 #include <net/transp_v6.h>
  73 #include <net/addrconf.h>
  74 #include <net/ip6_route.h>
  75 #include <net/inet_common.h>
  76 #include <net/inet_ecn.h>
  77 #include <net/sctp/sctp.h>
  78
  79 #include <asm/uaccess.h>
  80
  81 /* Event handler for inet6 address addition/deletion events.  */
  82 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  83                                 void *ptr)
  84 {
  85         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  86         struct sctp_sockaddr_entry *addr;
  87         struct list_head *pos, *temp;
  88
  89         switch (ev) {
  90         case NETDEV_UP:
  91                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  92                 if (addr) {
  93                         addr->a.v6.sin6_family = AF_INET6;
  94                         addr->a.v6.sin6_port = 0;
  95                         memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
  96                                  sizeof(struct in6_addr));
  97                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
  98                         list_add_tail(&addr->list, &sctp_local_addr_list);
  99                 }
 100                 break;
 101         case NETDEV_DOWN:
 102                 list_for_each_safe(pos, temp, &sctp_local_addr_list) {
 103                         addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 104                         if (ipv6_addr_equal(&addr->a.v6.sin6_addr, &ifa->addr)) {
 105                                 list_del(pos);
 106                                 kfree(addr);
 107                                 break;
 108                         }
 109                 }
 110
 111                 break;
 112         }
 113
 114         return NOTIFY_DONE;
 115 }
 116
 117 static struct notifier_block sctp_inet6addr_notifier = {
 118         .notifier_call = sctp_inet6addr_event,
 119 };
 120
 121 /* ICMP error handler. */
 122 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 123                              int type, int code, int offset, __be32 info)
 124 {
 125         struct inet6_dev *idev;
 126         struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
 127         struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
 128         struct sock *sk;
 129         struct sctp_association *asoc;
 130         struct sctp_transport *transport;
 131         struct ipv6_pinfo *np;
 132         char *saveip, *savesctp;
 133         int err;
 134
 135         idev = in6_dev_get(skb->dev);
 136
 137         /* Fix up skb to look at the embedded net header. */
 138         saveip = skb->nh.raw;
 139         savesctp  = skb->h.raw;
 140         skb->nh.ipv6h = iph;
 141         skb->h.raw = (char *)sh;
 142         sk = sctp_err_lookup(AF_INET6, skb, sh, &asoc, &transport);
 143         /* Put back, the original pointers. */
 144         skb->nh.raw = saveip;
 145         skb->h.raw = savesctp;
 146         if (!sk) {
 147                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 148                 goto out;
 149         }
 150
 151         /* Warning:  The sock lock is held.  Remember to call
 152          * sctp_err_finish!
 153          */
 154
 155         switch (type) {
 156         case ICMPV6_PKT_TOOBIG:
 157                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 158                 goto out_unlock;
 159         case ICMPV6_PARAMPROB:
 160                 if (ICMPV6_UNK_NEXTHDR == code) {
 161                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 162                         goto out_unlock;
 163                 }
 164                 break;
 165         default:
 166                 break;
 167         }
 168
 169         np = inet6_sk(sk);
 170         icmpv6_err_convert(type, code, &err);
 171         if (!sock_owned_by_user(sk) && np->recverr) {
 172                 sk->sk_err = err;
 173                 sk->sk_error_report(sk);
 174         } else {  /* Only an error on timeout */
 175                 sk->sk_err_soft = err;
 176         }
 177
 178 out_unlock:
 179         sctp_err_finish(sk, asoc);
 180 out:
 181         if (likely(idev != NULL))
 182                 in6_dev_put(idev);
 183 }
 184
 185 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 186 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
 187                         int ipfragok)
 188 {
 189         struct sock *sk = skb->sk;
 190         struct ipv6_pinfo *np = inet6_sk(sk);
 191         struct flowi fl;
 192
 193         memset(&fl, 0, sizeof(fl));
 194
 195         fl.proto = sk->sk_protocol;
 196
 197         /* Fill in the dest address from the route entry passed with the skb
 198          * and the source address from the transport.
 199          */
 200         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 201         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 202
 203         fl.fl6_flowlabel = np->flow_label;
 204         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 205         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 206                 fl.oif = transport->saddr.v6.sin6_scope_id;
 207         else
 208                 fl.oif = sk->sk_bound_dev_if;
 209
 210         if (np->opt && np->opt->srcrt) {
 211                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 212                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 213         }
 214
 215         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
 216                           "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
 217                           __FUNCTION__, skb, skb->len,
 218                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
 219
 220         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 221
 222         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
 223 }
 224
 225 /* Returns the dst cache entry for the given source and destination ip
 226  * addresses.
 227  */
 228 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 229                                          union sctp_addr *daddr,
 230                                          union sctp_addr *saddr)
 231 {
 232         struct dst_entry *dst;
 233         struct flowi fl;
 234
 235         memset(&fl, 0, sizeof(fl));
 236         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 237         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 238                 fl.oif = daddr->v6.sin6_scope_id;
 239
 240
 241         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
 242                           __FUNCTION__, NIP6(fl.fl6_dst));
 243
 244         if (saddr) {
 245                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 246                 SCTP_DEBUG_PRINTK(
 247                         "SRC=" NIP6_FMT " - ",
 248                         NIP6(fl.fl6_src));
 249         }
 250
 251         dst = ip6_route_output(NULL, &fl);
 252         if (!dst->error) {
 253                 struct rt6_info *rt;
 254                 rt = (struct rt6_info *)dst;
 255                 SCTP_DEBUG_PRINTK(
 256                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
 257                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
 258                 return dst;
 259         }
 260         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 261         dst_release(dst);
 262         return NULL;
 263 }
 264
 265 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 266  * addresses.
 267  */
 268 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 269                                          union sctp_addr *s2)
 270 {
 271         struct in6_addr *a1 = &s1->v6.sin6_addr;
 272         struct in6_addr *a2 = &s2->v6.sin6_addr;
 273         int i, j;
 274
 275         for (i = 0; i < 4 ; i++) {
 276                 __be32 a1xora2;
 277
 278                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 279
 280                 if ((j = fls(ntohl(a1xora2))))
 281                         return (i * 32 + 32 - j);
 282         }
 283
 284         return (i*32);
 285 }
 286
 287 /* Fills in the source address(saddr) based on the destination address(daddr)
 288  * and asoc's bind address list.
 289  */
 290 static void sctp_v6_get_saddr(struct sctp_association *asoc,
 291                               struct dst_entry *dst,
 292                               union sctp_addr *daddr,
 293                               union sctp_addr *saddr)
 294 {
 295         struct sctp_bind_addr *bp;
 296         rwlock_t *addr_lock;
 297         struct sctp_sockaddr_entry *laddr;
 298         struct list_head *pos;
 299         sctp_scope_t scope;
 300         union sctp_addr *baddr = NULL;
 301         __u8 matchlen = 0;
 302         __u8 bmatchlen;
 303
 304         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
 305                           "daddr:" NIP6_FMT " ",
 306                           __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
 307
 308         if (!asoc) {
 309                 ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
 310                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
 311                                   NIP6(saddr->v6.sin6_addr));
 312                 return;
 313         }
 314
 315         scope = sctp_scope(daddr);
 316
 317         bp = &asoc->base.bind_addr;
 318         addr_lock = &asoc->base.addr_lock;
 319
 320         /* Go through the bind address list and find the best source address
 321          * that matches the scope of the destination address.
 322          */
 323         sctp_read_lock(addr_lock);
 324         list_for_each(pos, &bp->address_list) {
 325                 laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
 326                 if ((laddr->use_as_src) &&
 327                     (laddr->a.sa.sa_family == AF_INET6) &&
 328                     (scope <= sctp_scope(&laddr->a))) {
 329                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 330                         if (!baddr || (matchlen < bmatchlen)) {
 331                                 baddr = &laddr->a;
 332                                 matchlen = bmatchlen;
 333                         }
 334                 }
 335         }
 336
 337         if (baddr) {
 338                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 339                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
 340                                   NIP6(saddr->v6.sin6_addr));
 341         } else {
 342                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 343                        "address for the dest:" NIP6_FMT "\n",
 344                        __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
 345         }
 346
 347         sctp_read_unlock(addr_lock);
 348 }
 349
 350 /* Make a copy of all potential local addresses. */
 351 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 352                                   struct net_device *dev)
 353 {
 354         struct inet6_dev *in6_dev;
 355         struct inet6_ifaddr *ifp;
 356         struct sctp_sockaddr_entry *addr;
 357
 358         rcu_read_lock();
 359         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 360                 rcu_read_unlock();
 361                 return;
 362         }
 363
 364         read_lock(&in6_dev->lock);
 365         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 366                 /* Add the address to the local list.  */
 367                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 368                 if (addr) {
 369                         addr->a.v6.sin6_family = AF_INET6;
 370                         addr->a.v6.sin6_port = 0;
 371                         addr->a.v6.sin6_addr = ifp->addr;
 372                         addr->a.v6.sin6_scope_id = dev->ifindex;
 373                         INIT_LIST_HEAD(&addr->list);
 374                         list_add_tail(&addr->list, addrlist);
 375                 }
 376         }
 377
 378         read_unlock(&in6_dev->lock);
 379         rcu_read_unlock();
 380 }
 381
 382 /* Initialize a sockaddr_storage from in incoming skb. */
 383 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 384                              int is_saddr)
 385 {
 386         void *from;
 387         __be16 *port;
 388         struct sctphdr *sh;
 389
 390         port = &addr->v6.sin6_port;
 391         addr->v6.sin6_family = AF_INET6;
 392         addr->v6.sin6_flowinfo = 0; /* FIXME */
 393         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 394
 395         sh = (struct sctphdr *) skb->h.raw;
 396         if (is_saddr) {
 397                 *port  = sh->source;
 398                 from = &skb->nh.ipv6h->saddr;
 399         } else {
 400                 *port = sh->dest;
 401                 from = &skb->nh.ipv6h->daddr;
 402         }
 403         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 404 }
 405
 406 /* Initialize an sctp_addr from a socket. */
 407 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 408 {
 409         addr->v6.sin6_family = AF_INET6;
 410         addr->v6.sin6_port = 0;
 411         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 412 }
 413
 414 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 415 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 416 {
 417         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 418                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 419                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 420                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 421                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 422                         addr->v4.sin_addr.s_addr;
 423         } else {
 424                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 425         }
 426 }
 427
 428 /* Initialize sk->sk_daddr from sctp_addr. */
 429 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 430 {
 431         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 432                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 433                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 434                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 435                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 436         } else {
 437                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 438         }
 439 }
 440
 441 /* Initialize a sctp_addr from an address parameter. */
 442 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 443                                     union sctp_addr_param *param,
 444                                     __be16 port, int iif)
 445 {
 446         addr->v6.sin6_family = AF_INET6;
 447         addr->v6.sin6_port = port;
 448         addr->v6.sin6_flowinfo = 0; /* BUG */
 449         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 450         addr->v6.sin6_scope_id = iif;
 451 }
 452
 453 /* Initialize an address parameter from a sctp_addr and return the length
 454  * of the address parameter.
 455  */
 456 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 457                                  union sctp_addr_param *param)
 458 {
 459         int length = sizeof(sctp_ipv6addr_param_t);
 460
 461         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 462         param->v6.param_hdr.length = htons(length);
 463         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 464
 465         return length;
 466 }
 467
 468 /* Initialize a sctp_addr from a dst_entry. */
 469 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 470                               __be16 port)
 471 {
 472         struct rt6_info *rt = (struct rt6_info *)dst;
 473         addr->sa.sa_family = AF_INET6;
 474         addr->v6.sin6_port = port;
 475         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 476 }
 477
 478 /* Compare addresses exactly.
 479  * v4-mapped-v6 is also in consideration.
 480  */
 481 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 482                             const union sctp_addr *addr2)
 483 {
 484         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 485                 if (addr1->sa.sa_family == AF_INET &&
 486                     addr2->sa.sa_family == AF_INET6 &&
 487                     IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
 488                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 489                             addr2->v6.sin6_addr.s6_addr32[3] ==
 490                             addr1->v4.sin_addr.s_addr)
 491                                 return 1;
 492                 }
 493                 if (addr2->sa.sa_family == AF_INET &&
 494                     addr1->sa.sa_family == AF_INET6 &&
 495                     IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
 496                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 497                             addr1->v6.sin6_addr.s6_addr32[3] ==
 498                             addr2->v4.sin_addr.s_addr)
 499                                 return 1;
 500                 }
 501                 return 0;
 502         }
 503         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 504                 return 0;
 505         /* If this is a linklocal address, compare the scope_id. */
 506         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 507                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 508                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 509                         return 0;
 510                 }
 511         }
 512
 513         return 1;
 514 }
 515
 516 /* Initialize addr struct to INADDR_ANY. */
 517 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 518 {
 519         memset(addr, 0x00, sizeof(union sctp_addr));
 520         addr->v6.sin6_family = AF_INET6;
 521         addr->v6.sin6_port = port;
 522 }
 523
 524 /* Is this a wildcard address? */
 525 static int sctp_v6_is_any(const union sctp_addr *addr)
 526 {
 527         return ipv6_addr_any(&addr->v6.sin6_addr);
 528 }
 529
 530 /* Should this be available for binding?   */
 531 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 532 {
 533         int type;
 534         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 535
 536         type = ipv6_addr_type(in6);
 537         if (IPV6_ADDR_ANY == type)
 538                 return 1;
 539         if (type == IPV6_ADDR_MAPPED) {
 540                 if (sp && !sp->v4mapped)
 541                         return 0;
 542                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 543                         return 0;
 544                 sctp_v6_map_v4(addr);
 545                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 546         }
 547         if (!(type & IPV6_ADDR_UNICAST))
 548                 return 0;
 549
 550         return ipv6_chk_addr(in6, NULL, 0);
 551 }
 552
 553 /* This function checks if the address is a valid address to be used for
 554  * SCTP.
 555  *
 556  * Output:
 557  * Return 0 - If the address is a non-unicast or an illegal address.
 558  * Return 1 - If the address is a unicast.
 559  */
 560 static int sctp_v6_addr_valid(union sctp_addr *addr,
 561                               struct sctp_sock *sp,
 562                               const struct sk_buff *skb)
 563 {
 564         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 565
 566         /* Support v4-mapped-v6 address. */
 567         if (ret == IPV6_ADDR_MAPPED) {
 568                 /* Note: This routine is used in input, so v4-mapped-v6
 569                  * are disallowed here when there is no sctp_sock.
 570                  */
 571                 if (!sp || !sp->v4mapped)
 572                         return 0;
 573                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 574                         return 0;
 575                 sctp_v6_map_v4(addr);
 576                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 577         }
 578
 579         /* Is this a non-unicast address */
 580         if (!(ret & IPV6_ADDR_UNICAST))
 581                 return 0;
 582
 583         return 1;
 584 }
 585
 586 /* What is the scope of 'addr'?  */
 587 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 588 {
 589         int v6scope;
 590         sctp_scope_t retval;
 591
 592         /* The IPv6 scope is really a set of bit fields.
 593          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 594          */
 595
 596         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 597         switch (v6scope) {
 598         case IFA_HOST:
 599                 retval = SCTP_SCOPE_LOOPBACK;
 600                 break;
 601         case IFA_LINK:
 602                 retval = SCTP_SCOPE_LINK;
 603                 break;
 604         case IFA_SITE:
 605                 retval = SCTP_SCOPE_PRIVATE;
 606                 break;
 607         default:
 608                 retval = SCTP_SCOPE_GLOBAL;
 609                 break;
 610         };
 611
 612         return retval;
 613 }
 614
 615 /* Create and initialize a new sk for the socket to be returned by accept(). */
 616 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 617                                              struct sctp_association *asoc)
 618 {
 619         struct inet_sock *inet = inet_sk(sk);
 620         struct sock *newsk;
 621         struct inet_sock *newinet;
 622         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 623         struct sctp6_sock *newsctp6sk;
 624
 625         newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot, 1);
 626         if (!newsk)
 627                 goto out;
 628
 629         sock_init_data(NULL, newsk);
 630
 631         newsk->sk_type = SOCK_STREAM;
 632
 633         newsk->sk_prot = sk->sk_prot;
 634         newsk->sk_no_check = sk->sk_no_check;
 635         newsk->sk_reuse = sk->sk_reuse;
 636
 637         newsk->sk_destruct = inet_sock_destruct;
 638         newsk->sk_family = PF_INET6;
 639         newsk->sk_protocol = IPPROTO_SCTP;
 640         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 641         newsk->sk_shutdown = sk->sk_shutdown;
 642         sock_reset_flag(sk, SOCK_ZAPPED);
 643
 644         newsctp6sk = (struct sctp6_sock *)newsk;
 645         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 646
 647         newinet = inet_sk(newsk);
 648         newnp = inet6_sk(newsk);
 649
 650         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 651
 652         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 653          * and getpeername().
 654          */
 655         newinet->sport = inet->sport;
 656         newnp->saddr = np->saddr;
 657         newnp->rcv_saddr = np->rcv_saddr;
 658         newinet->dport = htons(asoc->peer.port);
 659         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 660
 661         /* Init the ipv4 part of the socket since we can have sockets
 662          * using v6 API for ipv4.
 663          */
 664         newinet->uc_ttl = -1;
 665         newinet->mc_loop = 1;
 666         newinet->mc_ttl = 1;
 667         newinet->mc_index = 0;
 668         newinet->mc_list = NULL;
 669
 670         if (ipv4_config.no_pmtu_disc)
 671                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 672         else
 673                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 674
 675         sk_refcnt_debug_inc(newsk);
 676
 677         if (newsk->sk_prot->init(newsk)) {
 678                 sk_common_release(newsk);
 679                 newsk = NULL;
 680         }
 681
 682 out:
 683         return newsk;
 684 }
 685
 686 /* Map v4 address to mapped v6 address */
 687 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 688 {
 689         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 690                 sctp_v4_map_v6(addr);
 691 }
 692
 693 /* Where did this skb come from?  */
 694 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 695 {
 696         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 697         return opt->iif;
 698 }
 699
 700 /* Was this packet marked by Explicit Congestion Notification? */
 701 static int sctp_v6_is_ce(const struct sk_buff *skb)
 702 {
 703         return *((__u32 *)(skb->nh.ipv6h)) & htonl(1<<20);
 704 }
 705
 706 /* Dump the v6 addr to the seq file. */
 707 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 708 {
 709         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
 710 }
 711
 712 /* Initialize a PF_INET6 socket msg_name. */
 713 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 714 {
 715         struct sockaddr_in6 *sin6;
 716
 717         sin6 = (struct sockaddr_in6 *)msgname;
 718         sin6->sin6_family = AF_INET6;
 719         sin6->sin6_flowinfo = 0;
 720         sin6->sin6_scope_id = 0; /*FIXME */
 721         *addr_len = sizeof(struct sockaddr_in6);
 722 }
 723
 724 /* Initialize a PF_INET msgname from a ulpevent. */
 725 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 726                                      char *msgname, int *addrlen)
 727 {
 728         struct sockaddr_in6 *sin6, *sin6from;
 729
 730         if (msgname) {
 731                 union sctp_addr *addr;
 732                 struct sctp_association *asoc;
 733
 734                 asoc = event->asoc;
 735                 sctp_inet6_msgname(msgname, addrlen);
 736                 sin6 = (struct sockaddr_in6 *)msgname;
 737                 sin6->sin6_port = htons(asoc->peer.port);
 738                 addr = &asoc->peer.primary_addr;
 739
 740                 /* Note: If we go to a common v6 format, this code
 741                  * will change.
 742                  */
 743
 744                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 745                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 746                     AF_INET == addr->sa.sa_family) {
 747                         sctp_v4_map_v6((union sctp_addr *)sin6);
 748                         sin6->sin6_addr.s6_addr32[3] =
 749                                 addr->v4.sin_addr.s_addr;
 750                         return;
 751                 }
 752
 753                 sin6from = &asoc->peer.primary_addr.v6;
 754                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 755                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 756                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 757         }
 758 }
 759
 760 /* Initialize a msg_name from an inbound skb. */
 761 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 762                                    int *addr_len)
 763 {
 764         struct sctphdr *sh;
 765         struct sockaddr_in6 *sin6;
 766
 767         if (msgname) {
 768                 sctp_inet6_msgname(msgname, addr_len);
 769                 sin6 = (struct sockaddr_in6 *)msgname;
 770                 sh = (struct sctphdr *)skb->h.raw;
 771                 sin6->sin6_port = sh->source;
 772
 773                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 774                 if (sctp_sk(skb->sk)->v4mapped &&
 775                     skb->nh.iph->version == 4) {
 776                         sctp_v4_map_v6((union sctp_addr *)sin6);
 777                         sin6->sin6_addr.s6_addr32[3] = skb->nh.iph->saddr;
 778                         return;
 779                 }
 780
 781                 /* Otherwise, just copy the v6 address. */
 782                 ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
 783                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 784                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 785                         sin6->sin6_scope_id = ev->iif;
 786                 }
 787         }
 788 }
 789
 790 /* Do we support this AF? */
 791 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 792 {
 793         switch (family) {
 794         case AF_INET6:
 795                 return 1;
 796         /* v4-mapped-v6 addresses */
 797         case AF_INET:
 798                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
 799                         return 1;
 800         default:
 801                 return 0;
 802         }
 803 }
 804
 805 /* Address matching with wildcards allowed.  This extra level
 806  * of indirection lets us choose whether a PF_INET6 should
 807  * disallow any v4 addresses if we so choose.
 808  */
 809 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 810                                const union sctp_addr *addr2,
 811                                struct sctp_sock *opt)
 812 {
 813         struct sctp_af *af1, *af2;
 814
 815         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 816         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 817
 818         if (!af1 || !af2)
 819                 return 0;
 820         /* Today, wildcard AF_INET/AF_INET6. */
 821         if (sctp_is_any(addr1) || sctp_is_any(addr2))
 822                 return 1;
 823
 824         if (addr1->sa.sa_family != addr2->sa.sa_family)
 825                 return 0;
 826
 827         return af1->cmp_addr(addr1, addr2);
 828 }
 829
 830 /* Verify that the provided sockaddr looks bindable.   Common verification,
 831  * has already been taken care of.
 832  */
 833 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 834 {
 835         struct sctp_af *af;
 836
 837         /* ASSERT: address family has already been verified. */
 838         if (addr->sa.sa_family != AF_INET6)
 839                 af = sctp_get_af_specific(addr->sa.sa_family);
 840         else {
 841                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 842                 struct net_device *dev;
 843
 844                 if (type & IPV6_ADDR_LINKLOCAL) {
 845                         if (!addr->v6.sin6_scope_id)
 846                                 return 0;
 847                         dev = dev_get_by_index(addr->v6.sin6_scope_id);
 848                         if (!dev)
 849                                 return 0;
 850                         dev_put(dev);
 851                 }
 852                 af = opt->pf->af;
 853         }
 854         return af->available(addr, opt);
 855 }
 856
 857 /* Verify that the provided sockaddr looks sendable.   Common verification,
 858  * has already been taken care of.
 859  */
 860 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 861 {
 862         struct sctp_af *af = NULL;
 863
 864         /* ASSERT: address family has already been verified. */
 865         if (addr->sa.sa_family != AF_INET6)
 866                 af = sctp_get_af_specific(addr->sa.sa_family);
 867         else {
 868                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 869                 struct net_device *dev;
 870
 871                 if (type & IPV6_ADDR_LINKLOCAL) {
 872                         if (!addr->v6.sin6_scope_id)
 873                                 return 0;
 874                         dev = dev_get_by_index(addr->v6.sin6_scope_id);
 875                         if (!dev)
 876                                 return 0;
 877                         dev_put(dev);
 878                 }
 879                 af = opt->pf->af;
 880         }
 881
 882         return af != NULL;
 883 }
 884
 885 /* Fill in Supported Address Type information for INIT and INIT-ACK
 886  * chunks.   Note: In the future, we may want to look at sock options
 887  * to determine whether a PF_INET6 socket really wants to have IPV4
 888  * addresses.
 889  * Returns number of addresses supported.
 890  */
 891 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 892                                       __be16 *types)
 893 {
 894         types[0] = SCTP_PARAM_IPV4_ADDRESS;
 895         types[1] = SCTP_PARAM_IPV6_ADDRESS;
 896         return 2;
 897 }
 898
 899 static const struct proto_ops inet6_seqpacket_ops = {
 900         .family            = PF_INET6,
 901         .owner             = THIS_MODULE,
 902         .release           = inet6_release,
 903         .bind              = inet6_bind,
 904         .connect           = inet_dgram_connect,
 905         .socketpair        = sock_no_socketpair,
 906         .accept            = inet_accept,
 907         .getname           = inet6_getname,
 908         .poll              = sctp_poll,
 909         .ioctl             = inet6_ioctl,
 910         .listen            = sctp_inet_listen,
 911         .shutdown          = inet_shutdown,
 912         .setsockopt        = sock_common_setsockopt,
 913         .getsockopt        = sock_common_getsockopt,
 914         .sendmsg           = inet_sendmsg,
 915         .recvmsg           = sock_common_recvmsg,
 916         .mmap              = sock_no_mmap,
 917 #ifdef CONFIG_COMPAT
 918         .compat_setsockopt = compat_sock_common_setsockopt,
 919         .compat_getsockopt = compat_sock_common_getsockopt,
 920 #endif
 921 };
 922
 923 static struct inet_protosw sctpv6_seqpacket_protosw = {
 924         .type          = SOCK_SEQPACKET,
 925         .protocol      = IPPROTO_SCTP,
 926         .prot          = &sctpv6_prot,
 927         .ops           = &inet6_seqpacket_ops,
 928         .capability    = -1,
 929         .no_check      = 0,
 930         .flags         = SCTP_PROTOSW_FLAG
 931 };
 932 static struct inet_protosw sctpv6_stream_protosw = {
 933         .type          = SOCK_STREAM,
 934         .protocol      = IPPROTO_SCTP,
 935         .prot          = &sctpv6_prot,
 936         .ops           = &inet6_seqpacket_ops,
 937         .capability    = -1,
 938         .no_check      = 0,
 939         .flags         = SCTP_PROTOSW_FLAG,
 940 };
 941
 942 static int sctp6_rcv(struct sk_buff **pskb)
 943 {
 944         return sctp_rcv(*pskb) ? -1 : 0;
 945 }
 946
 947 static struct inet6_protocol sctpv6_protocol = {
 948         .handler      = sctp6_rcv,
 949         .err_handler  = sctp_v6_err,
 950         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 951 };
 952
 953 static struct sctp_af sctp_ipv6_specific = {
 954         .sa_family         = AF_INET6,
 955         .sctp_xmit         = sctp_v6_xmit,
 956         .setsockopt        = ipv6_setsockopt,
 957         .getsockopt        = ipv6_getsockopt,
 958         .get_dst           = sctp_v6_get_dst,
 959         .get_saddr         = sctp_v6_get_saddr,
 960         .copy_addrlist     = sctp_v6_copy_addrlist,
 961         .from_skb          = sctp_v6_from_skb,
 962         .from_sk           = sctp_v6_from_sk,
 963         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 964         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 965         .from_addr_param   = sctp_v6_from_addr_param,
 966         .to_addr_param     = sctp_v6_to_addr_param,
 967         .dst_saddr         = sctp_v6_dst_saddr,
 968         .cmp_addr          = sctp_v6_cmp_addr,
 969         .scope             = sctp_v6_scope,
 970         .addr_valid        = sctp_v6_addr_valid,
 971         .inaddr_any        = sctp_v6_inaddr_any,
 972         .is_any            = sctp_v6_is_any,
 973         .available         = sctp_v6_available,
 974         .skb_iif           = sctp_v6_skb_iif,
 975         .is_ce             = sctp_v6_is_ce,
 976         .seq_dump_addr     = sctp_v6_seq_dump_addr,
 977         .net_header_len    = sizeof(struct ipv6hdr),
 978         .sockaddr_len      = sizeof(struct sockaddr_in6),
 979 #ifdef CONFIG_COMPAT
 980         .compat_setsockopt = compat_ipv6_setsockopt,
 981         .compat_getsockopt = compat_ipv6_getsockopt,
 982 #endif
 983 };
 984
 985 static struct sctp_pf sctp_pf_inet6_specific = {
 986         .event_msgname = sctp_inet6_event_msgname,
 987         .skb_msgname   = sctp_inet6_skb_msgname,
 988         .af_supported  = sctp_inet6_af_supported,
 989         .cmp_addr      = sctp_inet6_cmp_addr,
 990         .bind_verify   = sctp_inet6_bind_verify,
 991         .send_verify   = sctp_inet6_send_verify,
 992         .supported_addrs = sctp_inet6_supported_addrs,
 993         .create_accept_sk = sctp_v6_create_accept_sk,
 994         .addr_v4map    = sctp_v6_addr_v4map,
 995         .af            = &sctp_ipv6_specific,
 996 };
 997
 998 /* Initialize IPv6 support and register with inet6 stack.  */
 999 int sctp_v6_init(void)
1000 {
1001         int rc = proto_register(&sctpv6_prot, 1);
1002
1003         if (rc)
1004                 goto out;
1005         /* Register inet6 protocol. */
1006         rc = -EAGAIN;
1007         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1008                 goto out_unregister_sctp_proto;
1009
1010         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1011         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1012         inet6_register_protosw(&sctpv6_stream_protosw);
1013
1014         /* Register the SCTP specific PF_INET6 functions. */
1015         sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
1016
1017         /* Register the SCTP specific AF_INET6 functions. */
1018         sctp_register_af(&sctp_ipv6_specific);
1019
1020         /* Register notifier for inet6 address additions/deletions. */
1021         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1022         rc = 0;
1023 out:
1024         return rc;
1025 out_unregister_sctp_proto:
1026         proto_unregister(&sctpv6_prot);
1027         goto out;
1028 }
1029
1030 /* IPv6 specific exit support. */
1031 void sctp_v6_exit(void)
1032 {
1033         list_del(&sctp_ipv6_specific.list);
1034         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1035         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1036         inet6_unregister_protosw(&sctpv6_stream_protosw);
1037         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1038         proto_unregister(&sctpv6_prot);
1039 }