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                         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                         sctp_addr_wq_mgmt(addr, SCTP_ADDR_NEW);
 116                         spin_unlock_bh(&sctp_local_addr_lock);
 117                 }
 118                 break;
 119         case NETDEV_DOWN:
 120                 spin_lock_bh(&sctp_local_addr_lock);
 121                 list_for_each_entry_safe(addr, temp,
 122                                         &sctp_local_addr_list, list) {
 123                         if (addr->a.sa.sa_family == AF_INET6 &&
 124                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 125                                                 &ifa->addr)) {
 126                                 sctp_addr_wq_mgmt(addr, SCTP_ADDR_DEL);
 127                                 found = 1;
 128                                 addr->valid = 0;
 129                                 list_del_rcu(&addr->list);
 130                                 break;
 131                         }
 132                 }
 133                 spin_unlock_bh(&sctp_local_addr_lock);
 134                 if (found)
 135                         kfree_rcu(addr, rcu);
 136                 break;
 137         }
 138
 139         return NOTIFY_DONE;
 140 }
 141
 142 static struct notifier_block sctp_inet6addr_notifier = {
 143         .notifier_call = sctp_inet6addr_event,
 144 };
 145
 146 /* ICMP error handler. */
 147 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 148                              u8 type, u8 code, int offset, __be32 info)
 149 {
 150         struct inet6_dev *idev;
 151         struct sock *sk;
 152         struct sctp_association *asoc;
 153         struct sctp_transport *transport;
 154         struct ipv6_pinfo *np;
 155         sk_buff_data_t saveip, savesctp;
 156         int err;
 157
 158         idev = in6_dev_get(skb->dev);
 159
 160         /* Fix up skb to look at the embedded net header. */
 161         saveip   = skb->network_header;
 162         savesctp = skb->transport_header;
 163         skb_reset_network_header(skb);
 164         skb_set_transport_header(skb, offset);
 165         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 166         /* Put back, the original pointers. */
 167         skb->network_header   = saveip;
 168         skb->transport_header = savesctp;
 169         if (!sk) {
 170                 ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
 171                 goto out;
 172         }
 173
 174         /* Warning:  The sock lock is held.  Remember to call
 175          * sctp_err_finish!
 176          */
 177
 178         switch (type) {
 179         case ICMPV6_PKT_TOOBIG:
 180                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 181                 goto out_unlock;
 182         case ICMPV6_PARAMPROB:
 183                 if (ICMPV6_UNK_NEXTHDR == code) {
 184                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 185                         goto out_unlock;
 186                 }
 187                 break;
 188         case NDISC_REDIRECT:
 189                 sctp_icmp_redirect(sk, transport, skb);
 190                 break;
 191         default:
 192                 break;
 193         }
 194
 195         np = inet6_sk(sk);
 196         icmpv6_err_convert(type, code, &err);
 197         if (!sock_owned_by_user(sk) && np->recverr) {
 198                 sk->sk_err = err;
 199                 sk->sk_error_report(sk);
 200         } else {  /* Only an error on timeout */
 201                 sk->sk_err_soft = err;
 202         }
 203
 204 out_unlock:
 205         sctp_err_finish(sk, asoc);
 206 out:
 207         if (likely(idev != NULL))
 208                 in6_dev_put(idev);
 209 }
 210
 211 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 212 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 213 {
 214         struct sock *sk = skb->sk;
 215         struct ipv6_pinfo *np = inet6_sk(sk);
 216         struct flowi6 fl6;
 217
 218         memset(&fl6, 0, sizeof(fl6));
 219
 220         fl6.flowi6_proto = sk->sk_protocol;
 221
 222         /* Fill in the dest address from the route entry passed with the skb
 223          * and the source address from the transport.
 224          */
 225         fl6.daddr = transport->ipaddr.v6.sin6_addr;
 226         fl6.saddr = transport->saddr.v6.sin6_addr;
 227
 228         fl6.flowlabel = np->flow_label;
 229         IP6_ECN_flow_xmit(sk, fl6.flowlabel);
 230         if (ipv6_addr_type(&fl6.saddr) & IPV6_ADDR_LINKLOCAL)
 231                 fl6.flowi6_oif = transport->saddr.v6.sin6_scope_id;
 232         else
 233                 fl6.flowi6_oif = sk->sk_bound_dev_if;
 234
 235         if (np->opt && np->opt->srcrt) {
 236                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 237                 fl6.daddr = *rt0->addr;
 238         }
 239
 240         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 241                           __func__, skb, skb->len,
 242                           &fl6.saddr, &fl6.daddr);
 243
 244         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 245
 246         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 247                 skb->local_df = 1;
 248
 249         return ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 250 }
 251
 252 /* Returns the dst cache entry for the given source and destination ip
 253  * addresses.
 254  */
 255 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 256                             struct flowi *fl, struct sock *sk)
 257 {
 258         struct sctp_association *asoc = t->asoc;
 259         struct dst_entry *dst = NULL;
 260         struct flowi6 *fl6 = &fl->u.ip6;
 261         struct sctp_bind_addr *bp;
 262         struct sctp_sockaddr_entry *laddr;
 263         union sctp_addr *baddr = NULL;
 264         union sctp_addr *daddr = &t->ipaddr;
 265         union sctp_addr dst_saddr;
 266         __u8 matchlen = 0;
 267         __u8 bmatchlen;
 268         sctp_scope_t scope;
 269
 270         memset(fl6, 0, sizeof(struct flowi6));
 271         fl6->daddr = daddr->v6.sin6_addr;
 272         fl6->fl6_dport = daddr->v6.sin6_port;
 273         fl6->flowi6_proto = IPPROTO_SCTP;
 274         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 275                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 276
 277         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 278
 279         if (asoc)
 280                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 281
 282         if (saddr) {
 283                 fl6->saddr = saddr->v6.sin6_addr;
 284                 fl6->fl6_sport = saddr->v6.sin6_port;
 285                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
 286         }
 287
 288         dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 289         if (!asoc || saddr)
 290                 goto out;
 291
 292         bp = &asoc->base.bind_addr;
 293         scope = sctp_scope(daddr);
 294         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 295          * to see if we can use it.
 296          */
 297         if (!IS_ERR(dst)) {
 298                 /* Walk through the bind address list and look for a bind
 299                  * address that matches the source address of the returned dst.
 300                  */
 301                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 302                 rcu_read_lock();
 303                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 304                         if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
 305                                 continue;
 306
 307                         /* Do not compare against v4 addrs */
 308                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 309                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 310                                 rcu_read_unlock();
 311                                 goto out;
 312                         }
 313                 }
 314                 rcu_read_unlock();
 315                 /* None of the bound addresses match the source address of the
 316                  * dst. So release it.
 317                  */
 318                 dst_release(dst);
 319                 dst = NULL;
 320         }
 321
 322         /* Walk through the bind address list and try to get the
 323          * best source address for a given destination.
 324          */
 325         rcu_read_lock();
 326         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 327                 if (!laddr->valid && laddr->state != SCTP_ADDR_SRC)
 328                         continue;
 329                 if ((laddr->a.sa.sa_family == AF_INET6) &&
 330                     (scope <= sctp_scope(&laddr->a))) {
 331                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 332                         if (!baddr || (matchlen < bmatchlen)) {
 333                                 baddr = &laddr->a;
 334                                 matchlen = bmatchlen;
 335                         }
 336                 }
 337         }
 338         rcu_read_unlock();
 339         if (baddr) {
 340                 fl6->saddr = baddr->v6.sin6_addr;
 341                 fl6->fl6_sport = baddr->v6.sin6_port;
 342                 dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 343         }
 344
 345 out:
 346         if (!IS_ERR(dst)) {
 347                 struct rt6_info *rt;
 348                 rt = (struct rt6_info *)dst;
 349                 t->dst = dst;
 350                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 351                         &rt->rt6i_dst.addr, &fl6->saddr);
 352         } else {
 353                 t->dst = NULL;
 354                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
 355         }
 356 }
 357
 358 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 359  * addresses.
 360  */
 361 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 362                                          union sctp_addr *s2)
 363 {
 364         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 365 }
 366
 367 /* Fills in the source address(saddr) based on the destination address(daddr)
 368  * and asoc's bind address list.
 369  */
 370 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 371                               struct sctp_transport *t,
 372                               struct flowi *fl)
 373 {
 374         struct flowi6 *fl6 = &fl->u.ip6;
 375         union sctp_addr *saddr = &t->saddr;
 376
 377         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 378
 379         if (t->dst) {
 380                 saddr->v6.sin6_family = AF_INET6;
 381                 saddr->v6.sin6_addr = fl6->saddr;
 382         }
 383 }
 384
 385 /* Make a copy of all potential local addresses. */
 386 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 387                                   struct net_device *dev)
 388 {
 389         struct inet6_dev *in6_dev;
 390         struct inet6_ifaddr *ifp;
 391         struct sctp_sockaddr_entry *addr;
 392
 393         rcu_read_lock();
 394         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 395                 rcu_read_unlock();
 396                 return;
 397         }
 398
 399         read_lock_bh(&in6_dev->lock);
 400         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 401                 /* Add the address to the local list.  */
 402                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 403                 if (addr) {
 404                         addr->a.v6.sin6_family = AF_INET6;
 405                         addr->a.v6.sin6_port = 0;
 406                         addr->a.v6.sin6_addr = ifp->addr;
 407                         addr->a.v6.sin6_scope_id = dev->ifindex;
 408                         addr->valid = 1;
 409                         INIT_LIST_HEAD(&addr->list);
 410                         list_add_tail(&addr->list, addrlist);
 411                 }
 412         }
 413
 414         read_unlock_bh(&in6_dev->lock);
 415         rcu_read_unlock();
 416 }
 417
 418 /* Initialize a sockaddr_storage from in incoming skb. */
 419 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 420                              int is_saddr)
 421 {
 422         __be16 *port;
 423         struct sctphdr *sh;
 424
 425         port = &addr->v6.sin6_port;
 426         addr->v6.sin6_family = AF_INET6;
 427         addr->v6.sin6_flowinfo = 0; /* FIXME */
 428         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 429
 430         sh = sctp_hdr(skb);
 431         if (is_saddr) {
 432                 *port  = sh->source;
 433                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 434         } else {
 435                 *port = sh->dest;
 436                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 437         }
 438 }
 439
 440 /* Initialize an sctp_addr from a socket. */
 441 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 442 {
 443         addr->v6.sin6_family = AF_INET6;
 444         addr->v6.sin6_port = 0;
 445         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 446 }
 447
 448 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 449 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 450 {
 451         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 452                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 453                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 454                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 455                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 456                         addr->v4.sin_addr.s_addr;
 457         } else {
 458                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 459         }
 460 }
 461
 462 /* Initialize sk->sk_daddr from sctp_addr. */
 463 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 464 {
 465         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 466                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 467                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 468                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 469                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 470         } else {
 471                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 472         }
 473 }
 474
 475 /* Initialize a sctp_addr from an address parameter. */
 476 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 477                                     union sctp_addr_param *param,
 478                                     __be16 port, int iif)
 479 {
 480         addr->v6.sin6_family = AF_INET6;
 481         addr->v6.sin6_port = port;
 482         addr->v6.sin6_flowinfo = 0; /* BUG */
 483         addr->v6.sin6_addr = param->v6.addr;
 484         addr->v6.sin6_scope_id = iif;
 485 }
 486
 487 /* Initialize an address parameter from a sctp_addr and return the length
 488  * of the address parameter.
 489  */
 490 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 491                                  union sctp_addr_param *param)
 492 {
 493         int length = sizeof(sctp_ipv6addr_param_t);
 494
 495         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 496         param->v6.param_hdr.length = htons(length);
 497         param->v6.addr = addr->v6.sin6_addr;
 498
 499         return length;
 500 }
 501
 502 /* Initialize a sctp_addr from struct in6_addr. */
 503 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 504                               __be16 port)
 505 {
 506         addr->sa.sa_family = AF_INET6;
 507         addr->v6.sin6_port = port;
 508         addr->v6.sin6_addr = *saddr;
 509 }
 510
 511 /* Compare addresses exactly.
 512  * v4-mapped-v6 is also in consideration.
 513  */
 514 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 515                             const union sctp_addr *addr2)
 516 {
 517         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 518                 if (addr1->sa.sa_family == AF_INET &&
 519                     addr2->sa.sa_family == AF_INET6 &&
 520                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 521                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 522                             addr2->v6.sin6_addr.s6_addr32[3] ==
 523                             addr1->v4.sin_addr.s_addr)
 524                                 return 1;
 525                 }
 526                 if (addr2->sa.sa_family == AF_INET &&
 527                     addr1->sa.sa_family == AF_INET6 &&
 528                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 529                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 530                             addr1->v6.sin6_addr.s6_addr32[3] ==
 531                             addr2->v4.sin_addr.s_addr)
 532                                 return 1;
 533                 }
 534                 return 0;
 535         }
 536         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 537                 return 0;
 538         /* If this is a linklocal address, compare the scope_id. */
 539         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 540                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 541                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 542                         return 0;
 543                 }
 544         }
 545
 546         return 1;
 547 }
 548
 549 /* Initialize addr struct to INADDR_ANY. */
 550 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 551 {
 552         memset(addr, 0x00, sizeof(union sctp_addr));
 553         addr->v6.sin6_family = AF_INET6;
 554         addr->v6.sin6_port = port;
 555 }
 556
 557 /* Is this a wildcard address? */
 558 static int sctp_v6_is_any(const union sctp_addr *addr)
 559 {
 560         return ipv6_addr_any(&addr->v6.sin6_addr);
 561 }
 562
 563 /* Should this be available for binding?   */
 564 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 565 {
 566         int type;
 567         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 568
 569         type = ipv6_addr_type(in6);
 570         if (IPV6_ADDR_ANY == type)
 571                 return 1;
 572         if (type == IPV6_ADDR_MAPPED) {
 573                 if (sp && !sp->v4mapped)
 574                         return 0;
 575                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 576                         return 0;
 577                 sctp_v6_map_v4(addr);
 578                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 579         }
 580         if (!(type & IPV6_ADDR_UNICAST))
 581                 return 0;
 582
 583         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 584 }
 585
 586 /* This function checks if the address is a valid address to be used for
 587  * SCTP.
 588  *
 589  * Output:
 590  * Return 0 - If the address is a non-unicast or an illegal address.
 591  * Return 1 - If the address is a unicast.
 592  */
 593 static int sctp_v6_addr_valid(union sctp_addr *addr,
 594                               struct sctp_sock *sp,
 595                               const struct sk_buff *skb)
 596 {
 597         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 598
 599         /* Support v4-mapped-v6 address. */
 600         if (ret == IPV6_ADDR_MAPPED) {
 601                 /* Note: This routine is used in input, so v4-mapped-v6
 602                  * are disallowed here when there is no sctp_sock.
 603                  */
 604                 if (!sp || !sp->v4mapped)
 605                         return 0;
 606                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 607                         return 0;
 608                 sctp_v6_map_v4(addr);
 609                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 610         }
 611
 612         /* Is this a non-unicast address */
 613         if (!(ret & IPV6_ADDR_UNICAST))
 614                 return 0;
 615
 616         return 1;
 617 }
 618
 619 /* What is the scope of 'addr'?  */
 620 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 621 {
 622         int v6scope;
 623         sctp_scope_t retval;
 624
 625         /* The IPv6 scope is really a set of bit fields.
 626          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 627          */
 628
 629         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 630         switch (v6scope) {
 631         case IFA_HOST:
 632                 retval = SCTP_SCOPE_LOOPBACK;
 633                 break;
 634         case IFA_LINK:
 635                 retval = SCTP_SCOPE_LINK;
 636                 break;
 637         case IFA_SITE:
 638                 retval = SCTP_SCOPE_PRIVATE;
 639                 break;
 640         default:
 641                 retval = SCTP_SCOPE_GLOBAL;
 642                 break;
 643         }
 644
 645         return retval;
 646 }
 647
 648 /* Create and initialize a new sk for the socket to be returned by accept(). */
 649 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 650                                              struct sctp_association *asoc)
 651 {
 652         struct sock *newsk;
 653         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 654         struct sctp6_sock *newsctp6sk;
 655
 656         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 657         if (!newsk)
 658                 goto out;
 659
 660         sock_init_data(NULL, newsk);
 661
 662         sctp_copy_sock(newsk, sk, asoc);
 663         sock_reset_flag(sk, SOCK_ZAPPED);
 664
 665         newsctp6sk = (struct sctp6_sock *)newsk;
 666         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 667
 668         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 669
 670         newnp = inet6_sk(newsk);
 671
 672         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 673
 674         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 675          * and getpeername().
 676          */
 677         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 678
 679         sk_refcnt_debug_inc(newsk);
 680
 681         if (newsk->sk_prot->init(newsk)) {
 682                 sk_common_release(newsk);
 683                 newsk = NULL;
 684         }
 685
 686 out:
 687         return newsk;
 688 }
 689
 690 /* Map v4 address to mapped v6 address */
 691 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 692 {
 693         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 694                 sctp_v4_map_v6(addr);
 695 }
 696
 697 /* Where did this skb come from?  */
 698 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 699 {
 700         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 701         return opt->iif;
 702 }
 703
 704 /* Was this packet marked by Explicit Congestion Notification? */
 705 static int sctp_v6_is_ce(const struct sk_buff *skb)
 706 {
 707         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 708 }
 709
 710 /* Dump the v6 addr to the seq file. */
 711 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 712 {
 713         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 714 }
 715
 716 static void sctp_v6_ecn_capable(struct sock *sk)
 717 {
 718         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 719 }
 720
 721 /* Initialize a PF_INET6 socket msg_name. */
 722 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 723 {
 724         struct sockaddr_in6 *sin6;
 725
 726         sin6 = (struct sockaddr_in6 *)msgname;
 727         sin6->sin6_family = AF_INET6;
 728         sin6->sin6_flowinfo = 0;
 729         sin6->sin6_scope_id = 0; /*FIXME */
 730         *addr_len = sizeof(struct sockaddr_in6);
 731 }
 732
 733 /* Initialize a PF_INET msgname from a ulpevent. */
 734 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 735                                      char *msgname, int *addrlen)
 736 {
 737         struct sockaddr_in6 *sin6, *sin6from;
 738
 739         if (msgname) {
 740                 union sctp_addr *addr;
 741                 struct sctp_association *asoc;
 742
 743                 asoc = event->asoc;
 744                 sctp_inet6_msgname(msgname, addrlen);
 745                 sin6 = (struct sockaddr_in6 *)msgname;
 746                 sin6->sin6_port = htons(asoc->peer.port);
 747                 addr = &asoc->peer.primary_addr;
 748
 749                 /* Note: If we go to a common v6 format, this code
 750                  * will change.
 751                  */
 752
 753                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 754                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 755                     AF_INET == addr->sa.sa_family) {
 756                         sctp_v4_map_v6((union sctp_addr *)sin6);
 757                         sin6->sin6_addr.s6_addr32[3] =
 758                                 addr->v4.sin_addr.s_addr;
 759                         return;
 760                 }
 761
 762                 sin6from = &asoc->peer.primary_addr.v6;
 763                 sin6->sin6_addr = sin6from->sin6_addr;
 764                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 765                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 766         }
 767 }
 768
 769 /* Initialize a msg_name from an inbound skb. */
 770 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 771                                    int *addr_len)
 772 {
 773         struct sctphdr *sh;
 774         struct sockaddr_in6 *sin6;
 775
 776         if (msgname) {
 777                 sctp_inet6_msgname(msgname, addr_len);
 778                 sin6 = (struct sockaddr_in6 *)msgname;
 779                 sh = sctp_hdr(skb);
 780                 sin6->sin6_port = sh->source;
 781
 782                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 783                 if (sctp_sk(skb->sk)->v4mapped &&
 784                     ip_hdr(skb)->version == 4) {
 785                         sctp_v4_map_v6((union sctp_addr *)sin6);
 786                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 787                         return;
 788                 }
 789
 790                 /* Otherwise, just copy the v6 address. */
 791                 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 792                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 793                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 794                         sin6->sin6_scope_id = ev->iif;
 795                 }
 796         }
 797 }
 798
 799 /* Do we support this AF? */
 800 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 801 {
 802         switch (family) {
 803         case AF_INET6:
 804                 return 1;
 805         /* v4-mapped-v6 addresses */
 806         case AF_INET:
 807                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 808                         return 1;
 809         default:
 810                 return 0;
 811         }
 812 }
 813
 814 /* Address matching with wildcards allowed.  This extra level
 815  * of indirection lets us choose whether a PF_INET6 should
 816  * disallow any v4 addresses if we so choose.
 817  */
 818 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 819                                const union sctp_addr *addr2,
 820                                struct sctp_sock *opt)
 821 {
 822         struct sctp_af *af1, *af2;
 823         struct sock *sk = sctp_opt2sk(opt);
 824
 825         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 826         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 827
 828         if (!af1 || !af2)
 829                 return 0;
 830
 831         /* If the socket is IPv6 only, v4 addrs will not match */
 832         if (__ipv6_only_sock(sk) && af1 != af2)
 833                 return 0;
 834
 835         /* Today, wildcard AF_INET/AF_INET6. */
 836         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 837                 return 1;
 838
 839         if (addr1->sa.sa_family != addr2->sa.sa_family)
 840                 return 0;
 841
 842         return af1->cmp_addr(addr1, addr2);
 843 }
 844
 845 /* Verify that the provided sockaddr looks bindable.   Common verification,
 846  * has already been taken care of.
 847  */
 848 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 849 {
 850         struct sctp_af *af;
 851
 852         /* ASSERT: address family has already been verified. */
 853         if (addr->sa.sa_family != AF_INET6)
 854                 af = sctp_get_af_specific(addr->sa.sa_family);
 855         else {
 856                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 857                 struct net_device *dev;
 858
 859                 if (type & IPV6_ADDR_LINKLOCAL) {
 860                         if (!addr->v6.sin6_scope_id)
 861                                 return 0;
 862                         rcu_read_lock();
 863                         dev = dev_get_by_index_rcu(&init_net,
 864                                                    addr->v6.sin6_scope_id);
 865                         if (!dev ||
 866                             !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 867                                            dev, 0)) {
 868                                 rcu_read_unlock();
 869                                 return 0;
 870                         }
 871                         rcu_read_unlock();
 872                 } else if (type == IPV6_ADDR_MAPPED) {
 873                         if (!opt->v4mapped)
 874                                 return 0;
 875                 }
 876
 877                 af = opt->pf->af;
 878         }
 879         return af->available(addr, opt);
 880 }
 881
 882 /* Verify that the provided sockaddr looks sendable.   Common verification,
 883  * has already been taken care of.
 884  */
 885 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 886 {
 887         struct sctp_af *af = NULL;
 888
 889         /* ASSERT: address family has already been verified. */
 890         if (addr->sa.sa_family != AF_INET6)
 891                 af = sctp_get_af_specific(addr->sa.sa_family);
 892         else {
 893                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 894                 struct net_device *dev;
 895
 896                 if (type & IPV6_ADDR_LINKLOCAL) {
 897                         if (!addr->v6.sin6_scope_id)
 898                                 return 0;
 899                         rcu_read_lock();
 900                         dev = dev_get_by_index_rcu(&init_net,
 901                                                    addr->v6.sin6_scope_id);
 902                         rcu_read_unlock();
 903                         if (!dev)
 904                                 return 0;
 905                 }
 906                 af = opt->pf->af;
 907         }
 908
 909         return af != NULL;
 910 }
 911
 912 /* Fill in Supported Address Type information for INIT and INIT-ACK
 913  * chunks.   Note: In the future, we may want to look at sock options
 914  * to determine whether a PF_INET6 socket really wants to have IPV4
 915  * addresses.
 916  * Returns number of addresses supported.
 917  */
 918 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 919                                       __be16 *types)
 920 {
 921         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 922         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 923                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 924                 return 2;
 925         }
 926         return 1;
 927 }
 928
 929 static const struct proto_ops inet6_seqpacket_ops = {
 930         .family            = PF_INET6,
 931         .owner             = THIS_MODULE,
 932         .release           = inet6_release,
 933         .bind              = inet6_bind,
 934         .connect           = inet_dgram_connect,
 935         .socketpair        = sock_no_socketpair,
 936         .accept            = inet_accept,
 937         .getname           = inet6_getname,
 938         .poll              = sctp_poll,
 939         .ioctl             = inet6_ioctl,
 940         .listen            = sctp_inet_listen,
 941         .shutdown          = inet_shutdown,
 942         .setsockopt        = sock_common_setsockopt,
 943         .getsockopt        = sock_common_getsockopt,
 944         .sendmsg           = inet_sendmsg,
 945         .recvmsg           = sock_common_recvmsg,
 946         .mmap              = sock_no_mmap,
 947 #ifdef CONFIG_COMPAT
 948         .compat_setsockopt = compat_sock_common_setsockopt,
 949         .compat_getsockopt = compat_sock_common_getsockopt,
 950 #endif
 951 };
 952
 953 static struct inet_protosw sctpv6_seqpacket_protosw = {
 954         .type          = SOCK_SEQPACKET,
 955         .protocol      = IPPROTO_SCTP,
 956         .prot          = &sctpv6_prot,
 957         .ops           = &inet6_seqpacket_ops,
 958         .no_check      = 0,
 959         .flags         = SCTP_PROTOSW_FLAG
 960 };
 961 static struct inet_protosw sctpv6_stream_protosw = {
 962         .type          = SOCK_STREAM,
 963         .protocol      = IPPROTO_SCTP,
 964         .prot          = &sctpv6_prot,
 965         .ops           = &inet6_seqpacket_ops,
 966         .no_check      = 0,
 967         .flags         = SCTP_PROTOSW_FLAG,
 968 };
 969
 970 static int sctp6_rcv(struct sk_buff *skb)
 971 {
 972         return sctp_rcv(skb) ? -1 : 0;
 973 }
 974
 975 static const struct inet6_protocol sctpv6_protocol = {
 976         .handler      = sctp6_rcv,
 977         .err_handler  = sctp_v6_err,
 978         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 979 };
 980
 981 static struct sctp_af sctp_af_inet6 = {
 982         .sa_family         = AF_INET6,
 983         .sctp_xmit         = sctp_v6_xmit,
 984         .setsockopt        = ipv6_setsockopt,
 985         .getsockopt        = ipv6_getsockopt,
 986         .get_dst           = sctp_v6_get_dst,
 987         .get_saddr         = sctp_v6_get_saddr,
 988         .copy_addrlist     = sctp_v6_copy_addrlist,
 989         .from_skb          = sctp_v6_from_skb,
 990         .from_sk           = sctp_v6_from_sk,
 991         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 992         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 993         .from_addr_param   = sctp_v6_from_addr_param,
 994         .to_addr_param     = sctp_v6_to_addr_param,
 995         .cmp_addr          = sctp_v6_cmp_addr,
 996         .scope             = sctp_v6_scope,
 997         .addr_valid        = sctp_v6_addr_valid,
 998         .inaddr_any        = sctp_v6_inaddr_any,
 999         .is_any            = sctp_v6_is_any,
1000         .available         = sctp_v6_available,
1001         .skb_iif           = sctp_v6_skb_iif,
1002         .is_ce             = sctp_v6_is_ce,
1003         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1004         .ecn_capable       = sctp_v6_ecn_capable,
1005         .net_header_len    = sizeof(struct ipv6hdr),
1006         .sockaddr_len      = sizeof(struct sockaddr_in6),
1007 #ifdef CONFIG_COMPAT
1008         .compat_setsockopt = compat_ipv6_setsockopt,
1009         .compat_getsockopt = compat_ipv6_getsockopt,
1010 #endif
1011 };
1012
1013 static struct sctp_pf sctp_pf_inet6 = {
1014         .event_msgname = sctp_inet6_event_msgname,
1015         .skb_msgname   = sctp_inet6_skb_msgname,
1016         .af_supported  = sctp_inet6_af_supported,
1017         .cmp_addr      = sctp_inet6_cmp_addr,
1018         .bind_verify   = sctp_inet6_bind_verify,
1019         .send_verify   = sctp_inet6_send_verify,
1020         .supported_addrs = sctp_inet6_supported_addrs,
1021         .create_accept_sk = sctp_v6_create_accept_sk,
1022         .addr_v4map    = sctp_v6_addr_v4map,
1023         .af            = &sctp_af_inet6,
1024 };
1025
1026 /* Initialize IPv6 support and register with socket layer.  */
1027 void sctp_v6_pf_init(void)
1028 {
1029         /* Register the SCTP specific PF_INET6 functions. */
1030         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1031
1032         /* Register the SCTP specific AF_INET6 functions. */
1033         sctp_register_af(&sctp_af_inet6);
1034 }
1035
1036 void sctp_v6_pf_exit(void)
1037 {
1038         list_del(&sctp_af_inet6.list);
1039 }
1040
1041 /* Initialize IPv6 support and register with socket layer.  */
1042 int sctp_v6_protosw_init(void)
1043 {
1044         int rc;
1045
1046         rc = proto_register(&sctpv6_prot, 1);
1047         if (rc)
1048                 return rc;
1049
1050         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1051         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1052         inet6_register_protosw(&sctpv6_stream_protosw);
1053
1054         return 0;
1055 }
1056
1057 void sctp_v6_protosw_exit(void)
1058 {
1059         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1060         inet6_unregister_protosw(&sctpv6_stream_protosw);
1061         proto_unregister(&sctpv6_prot);
1062 }
1063
1064
1065 /* Register with inet6 layer. */
1066 int sctp_v6_add_protocol(void)
1067 {
1068         /* Register notifier for inet6 address additions/deletions. */
1069         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1070
1071         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1072                 return -EAGAIN;
1073
1074         return 0;
1075 }
1076
1077 /* Unregister with inet6 layer. */
1078 void sctp_v6_del_protocol(void)
1079 {
1080         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1081         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1082 }