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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  51
  52 #include <linux/module.h>
  53 #include <linux/errno.h>
  54 #include <linux/types.h>
  55 #include <linux/socket.h>
  56 #include <linux/sockios.h>
  57 #include <linux/net.h>
  58 #include <linux/in.h>
  59 #include <linux/in6.h>
  60 #include <linux/netdevice.h>
  61 #include <linux/init.h>
  62 #include <linux/ipsec.h>
  63 #include <linux/slab.h>
  64
  65 #include <linux/ipv6.h>
  66 #include <linux/icmpv6.h>
  67 #include <linux/random.h>
  68 #include <linux/seq_file.h>
  69
  70 #include <net/protocol.h>
  71 #include <net/ndisc.h>
  72 #include <net/ip.h>
  73 #include <net/ipv6.h>
  74 #include <net/transp_v6.h>
  75 #include <net/addrconf.h>
  76 #include <net/ip6_route.h>
  77 #include <net/inet_common.h>
  78 #include <net/inet_ecn.h>
  79 #include <net/sctp/sctp.h>
  80
  81 #include <asm/uaccess.h>
  82
  83 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  84                                          union sctp_addr *s2);
  85 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  86                               __be16 port);
  87 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  88                             const union sctp_addr *addr2);
  89
  90 /* Event handler for inet6 address addition/deletion events.
  91  * The sctp_local_addr_list needs to be protocted by a spin lock since
  92  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  93  * time and thus corrupt the list.
  94  * The reader side is protected with RCU.
  95  */
  96 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  97                                 void *ptr)
  98 {
  99         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
 100         struct sctp_sockaddr_entry *addr = NULL;
 101         struct sctp_sockaddr_entry *temp;
 102         int found = 0;
 103
 104         switch (ev) {
 105         case NETDEV_UP:
 106                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 107                 if (addr) {
 108                         addr->a.v6.sin6_family = AF_INET6;
 109                         addr->a.v6.sin6_port = 0;
 110                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifa->addr);
 111                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 112                         addr->valid = 1;
 113                         spin_lock_bh(&sctp_local_addr_lock);
 114                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
 115                         spin_unlock_bh(&sctp_local_addr_lock);
 116                 }
 117                 break;
 118         case NETDEV_DOWN:
 119                 spin_lock_bh(&sctp_local_addr_lock);
 120                 list_for_each_entry_safe(addr, temp,
 121                                         &sctp_local_addr_list, list) {
 122                         if (addr->a.sa.sa_family == AF_INET6 &&
 123                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 124                                                 &ifa->addr)) {
 125                                 found = 1;
 126                                 addr->valid = 0;
 127                                 list_del_rcu(&addr->list);
 128                                 break;
 129                         }
 130                 }
 131                 spin_unlock_bh(&sctp_local_addr_lock);
 132                 if (found)
 133                         kfree_rcu(addr, rcu);
 134                 break;
 135         }
 136
 137         return NOTIFY_DONE;
 138 }
 139
 140 static struct notifier_block sctp_inet6addr_notifier = {
 141         .notifier_call = sctp_inet6addr_event,
 142 };
 143
 144 /* ICMP error handler. */
 145 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 146                              u8 type, u8 code, int offset, __be32 info)
 147 {
 148         struct inet6_dev *idev;
 149         struct sock *sk;
 150         struct sctp_association *asoc;
 151         struct sctp_transport *transport;
 152         struct ipv6_pinfo *np;
 153         sk_buff_data_t saveip, savesctp;
 154         int err;
 155
 156         idev = in6_dev_get(skb->dev);
 157
 158         /* Fix up skb to look at the embedded net header. */
 159         saveip   = skb->network_header;
 160         savesctp = skb->transport_header;
 161         skb_reset_network_header(skb);
 162         skb_set_transport_header(skb, offset);
 163         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 164         /* Put back, the original pointers. */
 165         skb->network_header   = saveip;
 166         skb->transport_header = savesctp;
 167         if (!sk) {
 168                 ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
 169                 goto out;
 170         }
 171
 172         /* Warning:  The sock lock is held.  Remember to call
 173          * sctp_err_finish!
 174          */
 175
 176         switch (type) {
 177         case ICMPV6_PKT_TOOBIG:
 178                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 179                 goto out_unlock;
 180         case ICMPV6_PARAMPROB:
 181                 if (ICMPV6_UNK_NEXTHDR == code) {
 182                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 183                         goto out_unlock;
 184                 }
 185                 break;
 186         default:
 187                 break;
 188         }
 189
 190         np = inet6_sk(sk);
 191         icmpv6_err_convert(type, code, &err);
 192         if (!sock_owned_by_user(sk) && np->recverr) {
 193                 sk->sk_err = err;
 194                 sk->sk_error_report(sk);
 195         } else {  /* Only an error on timeout */
 196                 sk->sk_err_soft = err;
 197         }
 198
 199 out_unlock:
 200         sctp_err_finish(sk, asoc);
 201 out:
 202         if (likely(idev != NULL))
 203                 in6_dev_put(idev);
 204 }
 205
 206 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 207 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 208 {
 209         struct sock *sk = skb->sk;
 210         struct ipv6_pinfo *np = inet6_sk(sk);
 211         struct flowi6 fl6;
 212
 213         memset(&fl6, 0, sizeof(fl6));
 214
 215         fl6.flowi6_proto = sk->sk_protocol;
 216
 217         /* Fill in the dest address from the route entry passed with the skb
 218          * and the source address from the transport.
 219          */
 220         ipv6_addr_copy(&fl6.daddr, &transport->ipaddr.v6.sin6_addr);
 221         ipv6_addr_copy(&fl6.saddr, &transport->saddr.v6.sin6_addr);
 222
 223         fl6.flowlabel = np->flow_label;
 224         IP6_ECN_flow_xmit(sk, fl6.flowlabel);
 225         if (ipv6_addr_type(&fl6.saddr) & IPV6_ADDR_LINKLOCAL)
 226                 fl6.flowi6_oif = transport->saddr.v6.sin6_scope_id;
 227         else
 228                 fl6.flowi6_oif = sk->sk_bound_dev_if;
 229
 230         if (np->opt && np->opt->srcrt) {
 231                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 232                 ipv6_addr_copy(&fl6.daddr, rt0->addr);
 233         }
 234
 235         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 236                           __func__, skb, skb->len,
 237                           &fl6.saddr, &fl6.daddr);
 238
 239         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 240
 241         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 242                 skb->local_df = 1;
 243
 244         return ip6_xmit(sk, skb, &fl6, np->opt);
 245 }
 246
 247 /* Returns the dst cache entry for the given source and destination ip
 248  * addresses.
 249  */
 250 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 251                             struct flowi *fl, struct sock *sk)
 252 {
 253         struct sctp_association *asoc = t->asoc;
 254         struct dst_entry *dst = NULL;
 255         struct flowi6 *fl6 = &fl->u.ip6;
 256         struct sctp_bind_addr *bp;
 257         struct sctp_sockaddr_entry *laddr;
 258         union sctp_addr *baddr = NULL;
 259         union sctp_addr *daddr = &t->ipaddr;
 260         union sctp_addr dst_saddr;
 261         __u8 matchlen = 0;
 262         __u8 bmatchlen;
 263         sctp_scope_t scope;
 264
 265         memset(fl6, 0, sizeof(struct flowi6));
 266         ipv6_addr_copy(&fl6->daddr, &daddr->v6.sin6_addr);
 267         fl6->fl6_dport = daddr->v6.sin6_port;
 268         fl6->flowi6_proto = IPPROTO_SCTP;
 269         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 270                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 271
 272         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 273
 274         if (asoc)
 275                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 276
 277         if (saddr) {
 278                 ipv6_addr_copy(&fl6->saddr, &saddr->v6.sin6_addr);
 279                 fl6->fl6_sport = saddr->v6.sin6_port;
 280                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
 281         }
 282
 283         dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 284         if (!asoc || saddr)
 285                 goto out;
 286
 287         bp = &asoc->base.bind_addr;
 288         scope = sctp_scope(daddr);
 289         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 290          * to see if we can use it.
 291          */
 292         if (!IS_ERR(dst)) {
 293                 /* Walk through the bind address list and look for a bind
 294                  * address that matches the source address of the returned dst.
 295                  */
 296                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 297                 rcu_read_lock();
 298                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 299                         if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
 300                                 continue;
 301
 302                         /* Do not compare against v4 addrs */
 303                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 304                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 305                                 rcu_read_unlock();
 306                                 goto out;
 307                         }
 308                 }
 309                 rcu_read_unlock();
 310                 /* None of the bound addresses match the source address of the
 311                  * dst. So release it.
 312                  */
 313                 dst_release(dst);
 314                 dst = NULL;
 315         }
 316
 317         /* Walk through the bind address list and try to get the
 318          * best source address for a given destination.
 319          */
 320         rcu_read_lock();
 321         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 322                 if (!laddr->valid && laddr->state != SCTP_ADDR_SRC)
 323                         continue;
 324                 if ((laddr->a.sa.sa_family == AF_INET6) &&
 325                     (scope <= sctp_scope(&laddr->a))) {
 326                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 327                         if (!baddr || (matchlen < bmatchlen)) {
 328                                 baddr = &laddr->a;
 329                                 matchlen = bmatchlen;
 330                         }
 331                 }
 332         }
 333         rcu_read_unlock();
 334         if (baddr) {
 335                 ipv6_addr_copy(&fl6->saddr, &baddr->v6.sin6_addr);
 336                 fl6->fl6_sport = baddr->v6.sin6_port;
 337                 dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 338         }
 339
 340 out:
 341         if (!IS_ERR(dst)) {
 342                 struct rt6_info *rt;
 343                 rt = (struct rt6_info *)dst;
 344                 t->dst = dst;
 345                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 346                         &rt->rt6i_dst.addr, &fl6->saddr);
 347         } else {
 348                 t->dst = NULL;
 349                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
 350         }
 351 }
 352
 353 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 354  * addresses.
 355  */
 356 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 357                                          union sctp_addr *s2)
 358 {
 359         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 360 }
 361
 362 /* Fills in the source address(saddr) based on the destination address(daddr)
 363  * and asoc's bind address list.
 364  */
 365 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 366                               struct sctp_transport *t,
 367                               struct flowi *fl)
 368 {
 369         struct flowi6 *fl6 = &fl->u.ip6;
 370         union sctp_addr *saddr = &t->saddr;
 371
 372         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 373
 374         if (t->dst) {
 375                 saddr->v6.sin6_family = AF_INET6;
 376                 ipv6_addr_copy(&saddr->v6.sin6_addr, &fl6->saddr);
 377         }
 378 }
 379
 380 /* Make a copy of all potential local addresses. */
 381 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 382                                   struct net_device *dev)
 383 {
 384         struct inet6_dev *in6_dev;
 385         struct inet6_ifaddr *ifp;
 386         struct sctp_sockaddr_entry *addr;
 387
 388         rcu_read_lock();
 389         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 390                 rcu_read_unlock();
 391                 return;
 392         }
 393
 394         read_lock_bh(&in6_dev->lock);
 395         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 396                 /* Add the address to the local list.  */
 397                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 398                 if (addr) {
 399                         addr->a.v6.sin6_family = AF_INET6;
 400                         addr->a.v6.sin6_port = 0;
 401                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifp->addr);
 402                         addr->a.v6.sin6_scope_id = dev->ifindex;
 403                         addr->valid = 1;
 404                         INIT_LIST_HEAD(&addr->list);
 405                         list_add_tail(&addr->list, addrlist);
 406                 }
 407         }
 408
 409         read_unlock_bh(&in6_dev->lock);
 410         rcu_read_unlock();
 411 }
 412
 413 /* Initialize a sockaddr_storage from in incoming skb. */
 414 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 415                              int is_saddr)
 416 {
 417         void *from;
 418         __be16 *port;
 419         struct sctphdr *sh;
 420
 421         port = &addr->v6.sin6_port;
 422         addr->v6.sin6_family = AF_INET6;
 423         addr->v6.sin6_flowinfo = 0; /* FIXME */
 424         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 425
 426         sh = sctp_hdr(skb);
 427         if (is_saddr) {
 428                 *port  = sh->source;
 429                 from = &ipv6_hdr(skb)->saddr;
 430         } else {
 431                 *port = sh->dest;
 432                 from = &ipv6_hdr(skb)->daddr;
 433         }
 434         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 435 }
 436
 437 /* Initialize an sctp_addr from a socket. */
 438 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 439 {
 440         addr->v6.sin6_family = AF_INET6;
 441         addr->v6.sin6_port = 0;
 442         ipv6_addr_copy(&addr->v6.sin6_addr, &inet6_sk(sk)->rcv_saddr);
 443 }
 444
 445 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 446 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 447 {
 448         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 449                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 450                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 451                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 452                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 453                         addr->v4.sin_addr.s_addr;
 454         } else {
 455                 ipv6_addr_copy(&inet6_sk(sk)->rcv_saddr, &addr->v6.sin6_addr);
 456         }
 457 }
 458
 459 /* Initialize sk->sk_daddr from sctp_addr. */
 460 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 461 {
 462         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 463                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 464                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 465                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 466                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 467         } else {
 468                 ipv6_addr_copy(&inet6_sk(sk)->daddr, &addr->v6.sin6_addr);
 469         }
 470 }
 471
 472 /* Initialize a sctp_addr from an address parameter. */
 473 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 474                                     union sctp_addr_param *param,
 475                                     __be16 port, int iif)
 476 {
 477         addr->v6.sin6_family = AF_INET6;
 478         addr->v6.sin6_port = port;
 479         addr->v6.sin6_flowinfo = 0; /* BUG */
 480         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 481         addr->v6.sin6_scope_id = iif;
 482 }
 483
 484 /* Initialize an address parameter from a sctp_addr and return the length
 485  * of the address parameter.
 486  */
 487 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 488                                  union sctp_addr_param *param)
 489 {
 490         int length = sizeof(sctp_ipv6addr_param_t);
 491
 492         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 493         param->v6.param_hdr.length = htons(length);
 494         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 495
 496         return length;
 497 }
 498
 499 /* Initialize a sctp_addr from struct in6_addr. */
 500 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 501                               __be16 port)
 502 {
 503         addr->sa.sa_family = AF_INET6;
 504         addr->v6.sin6_port = port;
 505         ipv6_addr_copy(&addr->v6.sin6_addr, saddr);
 506 }
 507
 508 /* Compare addresses exactly.
 509  * v4-mapped-v6 is also in consideration.
 510  */
 511 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 512                             const union sctp_addr *addr2)
 513 {
 514         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 515                 if (addr1->sa.sa_family == AF_INET &&
 516                     addr2->sa.sa_family == AF_INET6 &&
 517                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 518                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 519                             addr2->v6.sin6_addr.s6_addr32[3] ==
 520                             addr1->v4.sin_addr.s_addr)
 521                                 return 1;
 522                 }
 523                 if (addr2->sa.sa_family == AF_INET &&
 524                     addr1->sa.sa_family == AF_INET6 &&
 525                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 526                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 527                             addr1->v6.sin6_addr.s6_addr32[3] ==
 528                             addr2->v4.sin_addr.s_addr)
 529                                 return 1;
 530                 }
 531                 return 0;
 532         }
 533         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 534                 return 0;
 535         /* If this is a linklocal address, compare the scope_id. */
 536         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 537                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 538                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 539                         return 0;
 540                 }
 541         }
 542
 543         return 1;
 544 }
 545
 546 /* Initialize addr struct to INADDR_ANY. */
 547 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 548 {
 549         memset(addr, 0x00, sizeof(union sctp_addr));
 550         addr->v6.sin6_family = AF_INET6;
 551         addr->v6.sin6_port = port;
 552 }
 553
 554 /* Is this a wildcard address? */
 555 static int sctp_v6_is_any(const union sctp_addr *addr)
 556 {
 557         return ipv6_addr_any(&addr->v6.sin6_addr);
 558 }
 559
 560 /* Should this be available for binding?   */
 561 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 562 {
 563         int type;
 564         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 565
 566         type = ipv6_addr_type(in6);
 567         if (IPV6_ADDR_ANY == type)
 568                 return 1;
 569         if (type == IPV6_ADDR_MAPPED) {
 570                 if (sp && !sp->v4mapped)
 571                         return 0;
 572                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 573                         return 0;
 574                 sctp_v6_map_v4(addr);
 575                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 576         }
 577         if (!(type & IPV6_ADDR_UNICAST))
 578                 return 0;
 579
 580         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 581 }
 582
 583 /* This function checks if the address is a valid address to be used for
 584  * SCTP.
 585  *
 586  * Output:
 587  * Return 0 - If the address is a non-unicast or an illegal address.
 588  * Return 1 - If the address is a unicast.
 589  */
 590 static int sctp_v6_addr_valid(union sctp_addr *addr,
 591                               struct sctp_sock *sp,
 592                               const struct sk_buff *skb)
 593 {
 594         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 595
 596         /* Support v4-mapped-v6 address. */
 597         if (ret == IPV6_ADDR_MAPPED) {
 598                 /* Note: This routine is used in input, so v4-mapped-v6
 599                  * are disallowed here when there is no sctp_sock.
 600                  */
 601                 if (!sp || !sp->v4mapped)
 602                         return 0;
 603                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 604                         return 0;
 605                 sctp_v6_map_v4(addr);
 606                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 607         }
 608
 609         /* Is this a non-unicast address */
 610         if (!(ret & IPV6_ADDR_UNICAST))
 611                 return 0;
 612
 613         return 1;
 614 }
 615
 616 /* What is the scope of 'addr'?  */
 617 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 618 {
 619         int v6scope;
 620         sctp_scope_t retval;
 621
 622         /* The IPv6 scope is really a set of bit fields.
 623          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 624          */
 625
 626         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 627         switch (v6scope) {
 628         case IFA_HOST:
 629                 retval = SCTP_SCOPE_LOOPBACK;
 630                 break;
 631         case IFA_LINK:
 632                 retval = SCTP_SCOPE_LINK;
 633                 break;
 634         case IFA_SITE:
 635                 retval = SCTP_SCOPE_PRIVATE;
 636                 break;
 637         default:
 638                 retval = SCTP_SCOPE_GLOBAL;
 639                 break;
 640         }
 641
 642         return retval;
 643 }
 644
 645 /* Create and initialize a new sk for the socket to be returned by accept(). */
 646 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 647                                              struct sctp_association *asoc)
 648 {
 649         struct sock *newsk;
 650         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 651         struct sctp6_sock *newsctp6sk;
 652
 653         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 654         if (!newsk)
 655                 goto out;
 656
 657         sock_init_data(NULL, newsk);
 658
 659         sctp_copy_sock(newsk, sk, asoc);
 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         newnp = inet6_sk(newsk);
 668
 669         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 670
 671         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 672          * and getpeername().
 673          */
 674         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 675
 676         sk_refcnt_debug_inc(newsk);
 677
 678         if (newsk->sk_prot->init(newsk)) {
 679                 sk_common_release(newsk);
 680                 newsk = NULL;
 681         }
 682
 683 out:
 684         return newsk;
 685 }
 686
 687 /* Map v4 address to mapped v6 address */
 688 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 689 {
 690         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 691                 sctp_v4_map_v6(addr);
 692 }
 693
 694 /* Where did this skb come from?  */
 695 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 696 {
 697         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 698         return opt->iif;
 699 }
 700
 701 /* Was this packet marked by Explicit Congestion Notification? */
 702 static int sctp_v6_is_ce(const struct sk_buff *skb)
 703 {
 704         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 705 }
 706
 707 /* Dump the v6 addr to the seq file. */
 708 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 709 {
 710         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 711 }
 712
 713 static void sctp_v6_ecn_capable(struct sock *sk)
 714 {
 715         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 716 }
 717
 718 /* Initialize a PF_INET6 socket msg_name. */
 719 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 720 {
 721         struct sockaddr_in6 *sin6;
 722
 723         sin6 = (struct sockaddr_in6 *)msgname;
 724         sin6->sin6_family = AF_INET6;
 725         sin6->sin6_flowinfo = 0;
 726         sin6->sin6_scope_id = 0; /*FIXME */
 727         *addr_len = sizeof(struct sockaddr_in6);
 728 }
 729
 730 /* Initialize a PF_INET msgname from a ulpevent. */
 731 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 732                                      char *msgname, int *addrlen)
 733 {
 734         struct sockaddr_in6 *sin6, *sin6from;
 735
 736         if (msgname) {
 737                 union sctp_addr *addr;
 738                 struct sctp_association *asoc;
 739
 740                 asoc = event->asoc;
 741                 sctp_inet6_msgname(msgname, addrlen);
 742                 sin6 = (struct sockaddr_in6 *)msgname;
 743                 sin6->sin6_port = htons(asoc->peer.port);
 744                 addr = &asoc->peer.primary_addr;
 745
 746                 /* Note: If we go to a common v6 format, this code
 747                  * will change.
 748                  */
 749
 750                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 751                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 752                     AF_INET == addr->sa.sa_family) {
 753                         sctp_v4_map_v6((union sctp_addr *)sin6);
 754                         sin6->sin6_addr.s6_addr32[3] =
 755                                 addr->v4.sin_addr.s_addr;
 756                         return;
 757                 }
 758
 759                 sin6from = &asoc->peer.primary_addr.v6;
 760                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 761                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 762                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 763         }
 764 }
 765
 766 /* Initialize a msg_name from an inbound skb. */
 767 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 768                                    int *addr_len)
 769 {
 770         struct sctphdr *sh;
 771         struct sockaddr_in6 *sin6;
 772
 773         if (msgname) {
 774                 sctp_inet6_msgname(msgname, addr_len);
 775                 sin6 = (struct sockaddr_in6 *)msgname;
 776                 sh = sctp_hdr(skb);
 777                 sin6->sin6_port = sh->source;
 778
 779                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 780                 if (sctp_sk(skb->sk)->v4mapped &&
 781                     ip_hdr(skb)->version == 4) {
 782                         sctp_v4_map_v6((union sctp_addr *)sin6);
 783                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 784                         return;
 785                 }
 786
 787                 /* Otherwise, just copy the v6 address. */
 788                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 789                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 790                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 791                         sin6->sin6_scope_id = ev->iif;
 792                 }
 793         }
 794 }
 795
 796 /* Do we support this AF? */
 797 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 798 {
 799         switch (family) {
 800         case AF_INET6:
 801                 return 1;
 802         /* v4-mapped-v6 addresses */
 803         case AF_INET:
 804                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 805                         return 1;
 806         default:
 807                 return 0;
 808         }
 809 }
 810
 811 /* Address matching with wildcards allowed.  This extra level
 812  * of indirection lets us choose whether a PF_INET6 should
 813  * disallow any v4 addresses if we so choose.
 814  */
 815 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 816                                const union sctp_addr *addr2,
 817                                struct sctp_sock *opt)
 818 {
 819         struct sctp_af *af1, *af2;
 820         struct sock *sk = sctp_opt2sk(opt);
 821
 822         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 823         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 824
 825         if (!af1 || !af2)
 826                 return 0;
 827
 828         /* If the socket is IPv6 only, v4 addrs will not match */
 829         if (__ipv6_only_sock(sk) && af1 != af2)
 830                 return 0;
 831
 832         /* Today, wildcard AF_INET/AF_INET6. */
 833         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 834                 return 1;
 835
 836         if (addr1->sa.sa_family != addr2->sa.sa_family)
 837                 return 0;
 838
 839         return af1->cmp_addr(addr1, addr2);
 840 }
 841
 842 /* Verify that the provided sockaddr looks bindable.   Common verification,
 843  * has already been taken care of.
 844  */
 845 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 846 {
 847         struct sctp_af *af;
 848
 849         /* ASSERT: address family has already been verified. */
 850         if (addr->sa.sa_family != AF_INET6)
 851                 af = sctp_get_af_specific(addr->sa.sa_family);
 852         else {
 853                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 854                 struct net_device *dev;
 855
 856                 if (type & IPV6_ADDR_LINKLOCAL) {
 857                         if (!addr->v6.sin6_scope_id)
 858                                 return 0;
 859                         rcu_read_lock();
 860                         dev = dev_get_by_index_rcu(&init_net,
 861                                                    addr->v6.sin6_scope_id);
 862                         if (!dev ||
 863                             !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 864                                            dev, 0)) {
 865                                 rcu_read_unlock();
 866                                 return 0;
 867                         }
 868                         rcu_read_unlock();
 869                 } else if (type == IPV6_ADDR_MAPPED) {
 870                         if (!opt->v4mapped)
 871                                 return 0;
 872                 }
 873
 874                 af = opt->pf->af;
 875         }
 876         return af->available(addr, opt);
 877 }
 878
 879 /* Verify that the provided sockaddr looks sendable.   Common verification,
 880  * has already been taken care of.
 881  */
 882 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 883 {
 884         struct sctp_af *af = NULL;
 885
 886         /* ASSERT: address family has already been verified. */
 887         if (addr->sa.sa_family != AF_INET6)
 888                 af = sctp_get_af_specific(addr->sa.sa_family);
 889         else {
 890                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 891                 struct net_device *dev;
 892
 893                 if (type & IPV6_ADDR_LINKLOCAL) {
 894                         if (!addr->v6.sin6_scope_id)
 895                                 return 0;
 896                         rcu_read_lock();
 897                         dev = dev_get_by_index_rcu(&init_net,
 898                                                    addr->v6.sin6_scope_id);
 899                         rcu_read_unlock();
 900                         if (!dev)
 901                                 return 0;
 902                 }
 903                 af = opt->pf->af;
 904         }
 905
 906         return af != NULL;
 907 }
 908
 909 /* Fill in Supported Address Type information for INIT and INIT-ACK
 910  * chunks.   Note: In the future, we may want to look at sock options
 911  * to determine whether a PF_INET6 socket really wants to have IPV4
 912  * addresses.
 913  * Returns number of addresses supported.
 914  */
 915 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 916                                       __be16 *types)
 917 {
 918         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 919         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 920                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 921                 return 2;
 922         }
 923         return 1;
 924 }
 925
 926 static const struct proto_ops inet6_seqpacket_ops = {
 927         .family            = PF_INET6,
 928         .owner             = THIS_MODULE,
 929         .release           = inet6_release,
 930         .bind              = inet6_bind,
 931         .connect           = inet_dgram_connect,
 932         .socketpair        = sock_no_socketpair,
 933         .accept            = inet_accept,
 934         .getname           = inet6_getname,
 935         .poll              = sctp_poll,
 936         .ioctl             = inet6_ioctl,
 937         .listen            = sctp_inet_listen,
 938         .shutdown          = inet_shutdown,
 939         .setsockopt        = sock_common_setsockopt,
 940         .getsockopt        = sock_common_getsockopt,
 941         .sendmsg           = inet_sendmsg,
 942         .recvmsg           = sock_common_recvmsg,
 943         .mmap              = sock_no_mmap,
 944 #ifdef CONFIG_COMPAT
 945         .compat_setsockopt = compat_sock_common_setsockopt,
 946         .compat_getsockopt = compat_sock_common_getsockopt,
 947 #endif
 948 };
 949
 950 static struct inet_protosw sctpv6_seqpacket_protosw = {
 951         .type          = SOCK_SEQPACKET,
 952         .protocol      = IPPROTO_SCTP,
 953         .prot          = &sctpv6_prot,
 954         .ops           = &inet6_seqpacket_ops,
 955         .no_check      = 0,
 956         .flags         = SCTP_PROTOSW_FLAG
 957 };
 958 static struct inet_protosw sctpv6_stream_protosw = {
 959         .type          = SOCK_STREAM,
 960         .protocol      = IPPROTO_SCTP,
 961         .prot          = &sctpv6_prot,
 962         .ops           = &inet6_seqpacket_ops,
 963         .no_check      = 0,
 964         .flags         = SCTP_PROTOSW_FLAG,
 965 };
 966
 967 static int sctp6_rcv(struct sk_buff *skb)
 968 {
 969         return sctp_rcv(skb) ? -1 : 0;
 970 }
 971
 972 static const struct inet6_protocol sctpv6_protocol = {
 973         .handler      = sctp6_rcv,
 974         .err_handler  = sctp_v6_err,
 975         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 976 };
 977
 978 static struct sctp_af sctp_af_inet6 = {
 979         .sa_family         = AF_INET6,
 980         .sctp_xmit         = sctp_v6_xmit,
 981         .setsockopt        = ipv6_setsockopt,
 982         .getsockopt        = ipv6_getsockopt,
 983         .get_dst           = sctp_v6_get_dst,
 984         .get_saddr         = sctp_v6_get_saddr,
 985         .copy_addrlist     = sctp_v6_copy_addrlist,
 986         .from_skb          = sctp_v6_from_skb,
 987         .from_sk           = sctp_v6_from_sk,
 988         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 989         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 990         .from_addr_param   = sctp_v6_from_addr_param,
 991         .to_addr_param     = sctp_v6_to_addr_param,
 992         .cmp_addr          = sctp_v6_cmp_addr,
 993         .scope             = sctp_v6_scope,
 994         .addr_valid        = sctp_v6_addr_valid,
 995         .inaddr_any        = sctp_v6_inaddr_any,
 996         .is_any            = sctp_v6_is_any,
 997         .available         = sctp_v6_available,
 998         .skb_iif           = sctp_v6_skb_iif,
 999         .is_ce             = sctp_v6_is_ce,
1000         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1001         .ecn_capable       = sctp_v6_ecn_capable,
1002         .net_header_len    = sizeof(struct ipv6hdr),
1003         .sockaddr_len      = sizeof(struct sockaddr_in6),
1004 #ifdef CONFIG_COMPAT
1005         .compat_setsockopt = compat_ipv6_setsockopt,
1006         .compat_getsockopt = compat_ipv6_getsockopt,
1007 #endif
1008 };
1009
1010 static struct sctp_pf sctp_pf_inet6 = {
1011         .event_msgname = sctp_inet6_event_msgname,
1012         .skb_msgname   = sctp_inet6_skb_msgname,
1013         .af_supported  = sctp_inet6_af_supported,
1014         .cmp_addr      = sctp_inet6_cmp_addr,
1015         .bind_verify   = sctp_inet6_bind_verify,
1016         .send_verify   = sctp_inet6_send_verify,
1017         .supported_addrs = sctp_inet6_supported_addrs,
1018         .create_accept_sk = sctp_v6_create_accept_sk,
1019         .addr_v4map    = sctp_v6_addr_v4map,
1020         .af            = &sctp_af_inet6,
1021 };
1022
1023 /* Initialize IPv6 support and register with socket layer.  */
1024 void sctp_v6_pf_init(void)
1025 {
1026         /* Register the SCTP specific PF_INET6 functions. */
1027         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1028
1029         /* Register the SCTP specific AF_INET6 functions. */
1030         sctp_register_af(&sctp_af_inet6);
1031 }
1032
1033 void sctp_v6_pf_exit(void)
1034 {
1035         list_del(&sctp_af_inet6.list);
1036 }
1037
1038 /* Initialize IPv6 support and register with socket layer.  */
1039 int sctp_v6_protosw_init(void)
1040 {
1041         int rc;
1042
1043         rc = proto_register(&sctpv6_prot, 1);
1044         if (rc)
1045                 return rc;
1046
1047         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1048         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1049         inet6_register_protosw(&sctpv6_stream_protosw);
1050
1051         return 0;
1052 }
1053
1054 void sctp_v6_protosw_exit(void)
1055 {
1056         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1057         inet6_unregister_protosw(&sctpv6_stream_protosw);
1058         proto_unregister(&sctpv6_prot);
1059 }
1060
1061
1062 /* Register with inet6 layer. */
1063 int sctp_v6_add_protocol(void)
1064 {
1065         /* Register notifier for inet6 address additions/deletions. */
1066         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1067
1068         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1069                 return -EAGAIN;
1070
1071         return 0;
1072 }
1073
1074 /* Unregister with inet6 layer. */
1075 void sctp_v6_del_protocol(void)
1076 {
1077         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1078         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1079 }