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                         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         default:
 189                 break;
 190         }
 191
 192         np = inet6_sk(sk);
 193         icmpv6_err_convert(type, code, &err);
 194         if (!sock_owned_by_user(sk) && np->recverr) {
 195                 sk->sk_err = err;
 196                 sk->sk_error_report(sk);
 197         } else {  /* Only an error on timeout */
 198                 sk->sk_err_soft = err;
 199         }
 200
 201 out_unlock:
 202         sctp_err_finish(sk, asoc);
 203 out:
 204         if (likely(idev != NULL))
 205                 in6_dev_put(idev);
 206 }
 207
 208 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 209 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 210 {
 211         struct sock *sk = skb->sk;
 212         struct ipv6_pinfo *np = inet6_sk(sk);
 213         struct flowi6 fl6;
 214
 215         memset(&fl6, 0, sizeof(fl6));
 216
 217         fl6.flowi6_proto = sk->sk_protocol;
 218
 219         /* Fill in the dest address from the route entry passed with the skb
 220          * and the source address from the transport.
 221          */
 222         ipv6_addr_copy(&fl6.daddr, &transport->ipaddr.v6.sin6_addr);
 223         ipv6_addr_copy(&fl6.saddr, &transport->saddr.v6.sin6_addr);
 224
 225         fl6.flowlabel = np->flow_label;
 226         IP6_ECN_flow_xmit(sk, fl6.flowlabel);
 227         if (ipv6_addr_type(&fl6.saddr) & IPV6_ADDR_LINKLOCAL)
 228                 fl6.flowi6_oif = transport->saddr.v6.sin6_scope_id;
 229         else
 230                 fl6.flowi6_oif = sk->sk_bound_dev_if;
 231
 232         if (np->opt && np->opt->srcrt) {
 233                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 234                 ipv6_addr_copy(&fl6.daddr, rt0->addr);
 235         }
 236
 237         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 238                           __func__, skb, skb->len,
 239                           &fl6.saddr, &fl6.daddr);
 240
 241         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 242
 243         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 244                 skb->local_df = 1;
 245
 246         return ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 247 }
 248
 249 /* Returns the dst cache entry for the given source and destination ip
 250  * addresses.
 251  */
 252 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 253                             struct flowi *fl, struct sock *sk)
 254 {
 255         struct sctp_association *asoc = t->asoc;
 256         struct dst_entry *dst = NULL;
 257         struct flowi6 *fl6 = &fl->u.ip6;
 258         struct sctp_bind_addr *bp;
 259         struct sctp_sockaddr_entry *laddr;
 260         union sctp_addr *baddr = NULL;
 261         union sctp_addr *daddr = &t->ipaddr;
 262         union sctp_addr dst_saddr;
 263         __u8 matchlen = 0;
 264         __u8 bmatchlen;
 265         sctp_scope_t scope;
 266
 267         memset(fl6, 0, sizeof(struct flowi6));
 268         ipv6_addr_copy(&fl6->daddr, &daddr->v6.sin6_addr);
 269         fl6->fl6_dport = daddr->v6.sin6_port;
 270         fl6->flowi6_proto = IPPROTO_SCTP;
 271         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 272                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 273
 274         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 275
 276         if (asoc)
 277                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 278
 279         if (saddr) {
 280                 ipv6_addr_copy(&fl6->saddr, &saddr->v6.sin6_addr);
 281                 fl6->fl6_sport = saddr->v6.sin6_port;
 282                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
 283         }
 284
 285         dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 286         if (!asoc || saddr)
 287                 goto out;
 288
 289         bp = &asoc->base.bind_addr;
 290         scope = sctp_scope(daddr);
 291         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 292          * to see if we can use it.
 293          */
 294         if (!IS_ERR(dst)) {
 295                 /* Walk through the bind address list and look for a bind
 296                  * address that matches the source address of the returned dst.
 297                  */
 298                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 299                 rcu_read_lock();
 300                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 301                         if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
 302                                 continue;
 303
 304                         /* Do not compare against v4 addrs */
 305                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 306                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 307                                 rcu_read_unlock();
 308                                 goto out;
 309                         }
 310                 }
 311                 rcu_read_unlock();
 312                 /* None of the bound addresses match the source address of the
 313                  * dst. So release it.
 314                  */
 315                 dst_release(dst);
 316                 dst = NULL;
 317         }
 318
 319         /* Walk through the bind address list and try to get the
 320          * best source address for a given destination.
 321          */
 322         rcu_read_lock();
 323         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 324                 if (!laddr->valid && laddr->state != SCTP_ADDR_SRC)
 325                         continue;
 326                 if ((laddr->a.sa.sa_family == AF_INET6) &&
 327                     (scope <= sctp_scope(&laddr->a))) {
 328                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 329                         if (!baddr || (matchlen < bmatchlen)) {
 330                                 baddr = &laddr->a;
 331                                 matchlen = bmatchlen;
 332                         }
 333                 }
 334         }
 335         rcu_read_unlock();
 336         if (baddr) {
 337                 ipv6_addr_copy(&fl6->saddr, &baddr->v6.sin6_addr);
 338                 fl6->fl6_sport = baddr->v6.sin6_port;
 339                 dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 340         }
 341
 342 out:
 343         if (!IS_ERR(dst)) {
 344                 struct rt6_info *rt;
 345                 rt = (struct rt6_info *)dst;
 346                 t->dst = dst;
 347                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 348                         &rt->rt6i_dst.addr, &fl6->saddr);
 349         } else {
 350                 t->dst = NULL;
 351                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
 352         }
 353 }
 354
 355 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 356  * addresses.
 357  */
 358 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 359                                          union sctp_addr *s2)
 360 {
 361         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 362 }
 363
 364 /* Fills in the source address(saddr) based on the destination address(daddr)
 365  * and asoc's bind address list.
 366  */
 367 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 368                               struct sctp_transport *t,
 369                               struct flowi *fl)
 370 {
 371         struct flowi6 *fl6 = &fl->u.ip6;
 372         union sctp_addr *saddr = &t->saddr;
 373
 374         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 375
 376         if (t->dst) {
 377                 saddr->v6.sin6_family = AF_INET6;
 378                 ipv6_addr_copy(&saddr->v6.sin6_addr, &fl6->saddr);
 379         }
 380 }
 381
 382 /* Make a copy of all potential local addresses. */
 383 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 384                                   struct net_device *dev)
 385 {
 386         struct inet6_dev *in6_dev;
 387         struct inet6_ifaddr *ifp;
 388         struct sctp_sockaddr_entry *addr;
 389
 390         rcu_read_lock();
 391         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 392                 rcu_read_unlock();
 393                 return;
 394         }
 395
 396         read_lock_bh(&in6_dev->lock);
 397         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 398                 /* Add the address to the local list.  */
 399                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 400                 if (addr) {
 401                         addr->a.v6.sin6_family = AF_INET6;
 402                         addr->a.v6.sin6_port = 0;
 403                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifp->addr);
 404                         addr->a.v6.sin6_scope_id = dev->ifindex;
 405                         addr->valid = 1;
 406                         INIT_LIST_HEAD(&addr->list);
 407                         list_add_tail(&addr->list, addrlist);
 408                 }
 409         }
 410
 411         read_unlock_bh(&in6_dev->lock);
 412         rcu_read_unlock();
 413 }
 414
 415 /* Initialize a sockaddr_storage from in incoming skb. */
 416 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 417                              int is_saddr)
 418 {
 419         void *from;
 420         __be16 *port;
 421         struct sctphdr *sh;
 422
 423         port = &addr->v6.sin6_port;
 424         addr->v6.sin6_family = AF_INET6;
 425         addr->v6.sin6_flowinfo = 0; /* FIXME */
 426         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 427
 428         sh = sctp_hdr(skb);
 429         if (is_saddr) {
 430                 *port  = sh->source;
 431                 from = &ipv6_hdr(skb)->saddr;
 432         } else {
 433                 *port = sh->dest;
 434                 from = &ipv6_hdr(skb)->daddr;
 435         }
 436         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 437 }
 438
 439 /* Initialize an sctp_addr from a socket. */
 440 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 441 {
 442         addr->v6.sin6_family = AF_INET6;
 443         addr->v6.sin6_port = 0;
 444         ipv6_addr_copy(&addr->v6.sin6_addr, &inet6_sk(sk)->rcv_saddr);
 445 }
 446
 447 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 448 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 449 {
 450         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 451                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 452                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 453                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 454                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 455                         addr->v4.sin_addr.s_addr;
 456         } else {
 457                 ipv6_addr_copy(&inet6_sk(sk)->rcv_saddr, &addr->v6.sin6_addr);
 458         }
 459 }
 460
 461 /* Initialize sk->sk_daddr from sctp_addr. */
 462 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 463 {
 464         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 465                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 466                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 467                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 468                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 469         } else {
 470                 ipv6_addr_copy(&inet6_sk(sk)->daddr, &addr->v6.sin6_addr);
 471         }
 472 }
 473
 474 /* Initialize a sctp_addr from an address parameter. */
 475 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 476                                     union sctp_addr_param *param,
 477                                     __be16 port, int iif)
 478 {
 479         addr->v6.sin6_family = AF_INET6;
 480         addr->v6.sin6_port = port;
 481         addr->v6.sin6_flowinfo = 0; /* BUG */
 482         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 483         addr->v6.sin6_scope_id = iif;
 484 }
 485
 486 /* Initialize an address parameter from a sctp_addr and return the length
 487  * of the address parameter.
 488  */
 489 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 490                                  union sctp_addr_param *param)
 491 {
 492         int length = sizeof(sctp_ipv6addr_param_t);
 493
 494         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 495         param->v6.param_hdr.length = htons(length);
 496         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 497
 498         return length;
 499 }
 500
 501 /* Initialize a sctp_addr from struct in6_addr. */
 502 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 503                               __be16 port)
 504 {
 505         addr->sa.sa_family = AF_INET6;
 506         addr->v6.sin6_port = port;
 507         ipv6_addr_copy(&addr->v6.sin6_addr, saddr);
 508 }
 509
 510 /* Compare addresses exactly.
 511  * v4-mapped-v6 is also in consideration.
 512  */
 513 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 514                             const union sctp_addr *addr2)
 515 {
 516         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 517                 if (addr1->sa.sa_family == AF_INET &&
 518                     addr2->sa.sa_family == AF_INET6 &&
 519                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 520                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 521                             addr2->v6.sin6_addr.s6_addr32[3] ==
 522                             addr1->v4.sin_addr.s_addr)
 523                                 return 1;
 524                 }
 525                 if (addr2->sa.sa_family == AF_INET &&
 526                     addr1->sa.sa_family == AF_INET6 &&
 527                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 528                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 529                             addr1->v6.sin6_addr.s6_addr32[3] ==
 530                             addr2->v4.sin_addr.s_addr)
 531                                 return 1;
 532                 }
 533                 return 0;
 534         }
 535         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 536                 return 0;
 537         /* If this is a linklocal address, compare the scope_id. */
 538         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 539                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 540                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 541                         return 0;
 542                 }
 543         }
 544
 545         return 1;
 546 }
 547
 548 /* Initialize addr struct to INADDR_ANY. */
 549 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 550 {
 551         memset(addr, 0x00, sizeof(union sctp_addr));
 552         addr->v6.sin6_family = AF_INET6;
 553         addr->v6.sin6_port = port;
 554 }
 555
 556 /* Is this a wildcard address? */
 557 static int sctp_v6_is_any(const union sctp_addr *addr)
 558 {
 559         return ipv6_addr_any(&addr->v6.sin6_addr);
 560 }
 561
 562 /* Should this be available for binding?   */
 563 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 564 {
 565         int type;
 566         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 567
 568         type = ipv6_addr_type(in6);
 569         if (IPV6_ADDR_ANY == type)
 570                 return 1;
 571         if (type == IPV6_ADDR_MAPPED) {
 572                 if (sp && !sp->v4mapped)
 573                         return 0;
 574                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 575                         return 0;
 576                 sctp_v6_map_v4(addr);
 577                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 578         }
 579         if (!(type & IPV6_ADDR_UNICAST))
 580                 return 0;
 581
 582         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 583 }
 584
 585 /* This function checks if the address is a valid address to be used for
 586  * SCTP.
 587  *
 588  * Output:
 589  * Return 0 - If the address is a non-unicast or an illegal address.
 590  * Return 1 - If the address is a unicast.
 591  */
 592 static int sctp_v6_addr_valid(union sctp_addr *addr,
 593                               struct sctp_sock *sp,
 594                               const struct sk_buff *skb)
 595 {
 596         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 597
 598         /* Support v4-mapped-v6 address. */
 599         if (ret == IPV6_ADDR_MAPPED) {
 600                 /* Note: This routine is used in input, so v4-mapped-v6
 601                  * are disallowed here when there is no sctp_sock.
 602                  */
 603                 if (!sp || !sp->v4mapped)
 604                         return 0;
 605                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 606                         return 0;
 607                 sctp_v6_map_v4(addr);
 608                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 609         }
 610
 611         /* Is this a non-unicast address */
 612         if (!(ret & IPV6_ADDR_UNICAST))
 613                 return 0;
 614
 615         return 1;
 616 }
 617
 618 /* What is the scope of 'addr'?  */
 619 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 620 {
 621         int v6scope;
 622         sctp_scope_t retval;
 623
 624         /* The IPv6 scope is really a set of bit fields.
 625          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 626          */
 627
 628         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 629         switch (v6scope) {
 630         case IFA_HOST:
 631                 retval = SCTP_SCOPE_LOOPBACK;
 632                 break;
 633         case IFA_LINK:
 634                 retval = SCTP_SCOPE_LINK;
 635                 break;
 636         case IFA_SITE:
 637                 retval = SCTP_SCOPE_PRIVATE;
 638                 break;
 639         default:
 640                 retval = SCTP_SCOPE_GLOBAL;
 641                 break;
 642         }
 643
 644         return retval;
 645 }
 646
 647 /* Create and initialize a new sk for the socket to be returned by accept(). */
 648 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 649                                              struct sctp_association *asoc)
 650 {
 651         struct sock *newsk;
 652         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 653         struct sctp6_sock *newsctp6sk;
 654
 655         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 656         if (!newsk)
 657                 goto out;
 658
 659         sock_init_data(NULL, newsk);
 660
 661         sctp_copy_sock(newsk, sk, asoc);
 662         sock_reset_flag(sk, SOCK_ZAPPED);
 663
 664         newsctp6sk = (struct sctp6_sock *)newsk;
 665         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 666
 667         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 668
 669         newnp = inet6_sk(newsk);
 670
 671         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 672
 673         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 674          * and getpeername().
 675          */
 676         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 677
 678         sk_refcnt_debug_inc(newsk);
 679
 680         if (newsk->sk_prot->init(newsk)) {
 681                 sk_common_release(newsk);
 682                 newsk = NULL;
 683         }
 684
 685 out:
 686         return newsk;
 687 }
 688
 689 /* Map v4 address to mapped v6 address */
 690 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 691 {
 692         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 693                 sctp_v4_map_v6(addr);
 694 }
 695
 696 /* Where did this skb come from?  */
 697 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 698 {
 699         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 700         return opt->iif;
 701 }
 702
 703 /* Was this packet marked by Explicit Congestion Notification? */
 704 static int sctp_v6_is_ce(const struct sk_buff *skb)
 705 {
 706         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 707 }
 708
 709 /* Dump the v6 addr to the seq file. */
 710 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 711 {
 712         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 713 }
 714
 715 static void sctp_v6_ecn_capable(struct sock *sk)
 716 {
 717         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 718 }
 719
 720 /* Initialize a PF_INET6 socket msg_name. */
 721 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 722 {
 723         struct sockaddr_in6 *sin6;
 724
 725         sin6 = (struct sockaddr_in6 *)msgname;
 726         sin6->sin6_family = AF_INET6;
 727         sin6->sin6_flowinfo = 0;
 728         sin6->sin6_scope_id = 0; /*FIXME */
 729         *addr_len = sizeof(struct sockaddr_in6);
 730 }
 731
 732 /* Initialize a PF_INET msgname from a ulpevent. */
 733 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 734                                      char *msgname, int *addrlen)
 735 {
 736         struct sockaddr_in6 *sin6, *sin6from;
 737
 738         if (msgname) {
 739                 union sctp_addr *addr;
 740                 struct sctp_association *asoc;
 741
 742                 asoc = event->asoc;
 743                 sctp_inet6_msgname(msgname, addrlen);
 744                 sin6 = (struct sockaddr_in6 *)msgname;
 745                 sin6->sin6_port = htons(asoc->peer.port);
 746                 addr = &asoc->peer.primary_addr;
 747
 748                 /* Note: If we go to a common v6 format, this code
 749                  * will change.
 750                  */
 751
 752                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 753                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 754                     AF_INET == addr->sa.sa_family) {
 755                         sctp_v4_map_v6((union sctp_addr *)sin6);
 756                         sin6->sin6_addr.s6_addr32[3] =
 757                                 addr->v4.sin_addr.s_addr;
 758                         return;
 759                 }
 760
 761                 sin6from = &asoc->peer.primary_addr.v6;
 762                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 763                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 764                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 765         }
 766 }
 767
 768 /* Initialize a msg_name from an inbound skb. */
 769 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 770                                    int *addr_len)
 771 {
 772         struct sctphdr *sh;
 773         struct sockaddr_in6 *sin6;
 774
 775         if (msgname) {
 776                 sctp_inet6_msgname(msgname, addr_len);
 777                 sin6 = (struct sockaddr_in6 *)msgname;
 778                 sh = sctp_hdr(skb);
 779                 sin6->sin6_port = sh->source;
 780
 781                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 782                 if (sctp_sk(skb->sk)->v4mapped &&
 783                     ip_hdr(skb)->version == 4) {
 784                         sctp_v4_map_v6((union sctp_addr *)sin6);
 785                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 786                         return;
 787                 }
 788
 789                 /* Otherwise, just copy the v6 address. */
 790                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 791                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 792                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 793                         sin6->sin6_scope_id = ev->iif;
 794                 }
 795         }
 796 }
 797
 798 /* Do we support this AF? */
 799 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 800 {
 801         switch (family) {
 802         case AF_INET6:
 803                 return 1;
 804         /* v4-mapped-v6 addresses */
 805         case AF_INET:
 806                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 807                         return 1;
 808         default:
 809                 return 0;
 810         }
 811 }
 812
 813 /* Address matching with wildcards allowed.  This extra level
 814  * of indirection lets us choose whether a PF_INET6 should
 815  * disallow any v4 addresses if we so choose.
 816  */
 817 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 818                                const union sctp_addr *addr2,
 819                                struct sctp_sock *opt)
 820 {
 821         struct sctp_af *af1, *af2;
 822         struct sock *sk = sctp_opt2sk(opt);
 823
 824         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 825         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 826
 827         if (!af1 || !af2)
 828                 return 0;
 829
 830         /* If the socket is IPv6 only, v4 addrs will not match */
 831         if (__ipv6_only_sock(sk) && af1 != af2)
 832                 return 0;
 833
 834         /* Today, wildcard AF_INET/AF_INET6. */
 835         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 836                 return 1;
 837
 838         if (addr1->sa.sa_family != addr2->sa.sa_family)
 839                 return 0;
 840
 841         return af1->cmp_addr(addr1, addr2);
 842 }
 843
 844 /* Verify that the provided sockaddr looks bindable.   Common verification,
 845  * has already been taken care of.
 846  */
 847 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 848 {
 849         struct sctp_af *af;
 850
 851         /* ASSERT: address family has already been verified. */
 852         if (addr->sa.sa_family != AF_INET6)
 853                 af = sctp_get_af_specific(addr->sa.sa_family);
 854         else {
 855                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 856                 struct net_device *dev;
 857
 858                 if (type & IPV6_ADDR_LINKLOCAL) {
 859                         if (!addr->v6.sin6_scope_id)
 860                                 return 0;
 861                         rcu_read_lock();
 862                         dev = dev_get_by_index_rcu(&init_net,
 863                                                    addr->v6.sin6_scope_id);
 864                         if (!dev ||
 865                             !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 866                                            dev, 0)) {
 867                                 rcu_read_unlock();
 868                                 return 0;
 869                         }
 870                         rcu_read_unlock();
 871                 } else if (type == IPV6_ADDR_MAPPED) {
 872                         if (!opt->v4mapped)
 873                                 return 0;
 874                 }
 875
 876                 af = opt->pf->af;
 877         }
 878         return af->available(addr, opt);
 879 }
 880
 881 /* Verify that the provided sockaddr looks sendable.   Common verification,
 882  * has already been taken care of.
 883  */
 884 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 885 {
 886         struct sctp_af *af = NULL;
 887
 888         /* ASSERT: address family has already been verified. */
 889         if (addr->sa.sa_family != AF_INET6)
 890                 af = sctp_get_af_specific(addr->sa.sa_family);
 891         else {
 892                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 893                 struct net_device *dev;
 894
 895                 if (type & IPV6_ADDR_LINKLOCAL) {
 896                         if (!addr->v6.sin6_scope_id)
 897                                 return 0;
 898                         rcu_read_lock();
 899                         dev = dev_get_by_index_rcu(&init_net,
 900                                                    addr->v6.sin6_scope_id);
 901                         rcu_read_unlock();
 902                         if (!dev)
 903                                 return 0;
 904                 }
 905                 af = opt->pf->af;
 906         }
 907
 908         return af != NULL;
 909 }
 910
 911 /* Fill in Supported Address Type information for INIT and INIT-ACK
 912  * chunks.   Note: In the future, we may want to look at sock options
 913  * to determine whether a PF_INET6 socket really wants to have IPV4
 914  * addresses.
 915  * Returns number of addresses supported.
 916  */
 917 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 918                                       __be16 *types)
 919 {
 920         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 921         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 922                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 923                 return 2;
 924         }
 925         return 1;
 926 }
 927
 928 static const struct proto_ops inet6_seqpacket_ops = {
 929         .family            = PF_INET6,
 930         .owner             = THIS_MODULE,
 931         .release           = inet6_release,
 932         .bind              = inet6_bind,
 933         .connect           = inet_dgram_connect,
 934         .socketpair        = sock_no_socketpair,
 935         .accept            = inet_accept,
 936         .getname           = inet6_getname,
 937         .poll              = sctp_poll,
 938         .ioctl             = inet6_ioctl,
 939         .listen            = sctp_inet_listen,
 940         .shutdown          = inet_shutdown,
 941         .setsockopt        = sock_common_setsockopt,
 942         .getsockopt        = sock_common_getsockopt,
 943         .sendmsg           = inet_sendmsg,
 944         .recvmsg           = sock_common_recvmsg,
 945         .mmap              = sock_no_mmap,
 946 #ifdef CONFIG_COMPAT
 947         .compat_setsockopt = compat_sock_common_setsockopt,
 948         .compat_getsockopt = compat_sock_common_getsockopt,
 949 #endif
 950 };
 951
 952 static struct inet_protosw sctpv6_seqpacket_protosw = {
 953         .type          = SOCK_SEQPACKET,
 954         .protocol      = IPPROTO_SCTP,
 955         .prot          = &sctpv6_prot,
 956         .ops           = &inet6_seqpacket_ops,
 957         .no_check      = 0,
 958         .flags         = SCTP_PROTOSW_FLAG
 959 };
 960 static struct inet_protosw sctpv6_stream_protosw = {
 961         .type          = SOCK_STREAM,
 962         .protocol      = IPPROTO_SCTP,
 963         .prot          = &sctpv6_prot,
 964         .ops           = &inet6_seqpacket_ops,
 965         .no_check      = 0,
 966         .flags         = SCTP_PROTOSW_FLAG,
 967 };
 968
 969 static int sctp6_rcv(struct sk_buff *skb)
 970 {
 971         return sctp_rcv(skb) ? -1 : 0;
 972 }
 973
 974 static const struct inet6_protocol sctpv6_protocol = {
 975         .handler      = sctp6_rcv,
 976         .err_handler  = sctp_v6_err,
 977         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 978 };
 979
 980 static struct sctp_af sctp_af_inet6 = {
 981         .sa_family         = AF_INET6,
 982         .sctp_xmit         = sctp_v6_xmit,
 983         .setsockopt        = ipv6_setsockopt,
 984         .getsockopt        = ipv6_getsockopt,
 985         .get_dst           = sctp_v6_get_dst,
 986         .get_saddr         = sctp_v6_get_saddr,
 987         .copy_addrlist     = sctp_v6_copy_addrlist,
 988         .from_skb          = sctp_v6_from_skb,
 989         .from_sk           = sctp_v6_from_sk,
 990         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 991         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 992         .from_addr_param   = sctp_v6_from_addr_param,
 993         .to_addr_param     = sctp_v6_to_addr_param,
 994         .cmp_addr          = sctp_v6_cmp_addr,
 995         .scope             = sctp_v6_scope,
 996         .addr_valid        = sctp_v6_addr_valid,
 997         .inaddr_any        = sctp_v6_inaddr_any,
 998         .is_any            = sctp_v6_is_any,
 999         .available         = sctp_v6_available,
1000         .skb_iif           = sctp_v6_skb_iif,
1001         .is_ce             = sctp_v6_is_ce,
1002         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1003         .ecn_capable       = sctp_v6_ecn_capable,
1004         .net_header_len    = sizeof(struct ipv6hdr),
1005         .sockaddr_len      = sizeof(struct sockaddr_in6),
1006 #ifdef CONFIG_COMPAT
1007         .compat_setsockopt = compat_ipv6_setsockopt,
1008         .compat_getsockopt = compat_ipv6_getsockopt,
1009 #endif
1010 };
1011
1012 static struct sctp_pf sctp_pf_inet6 = {
1013         .event_msgname = sctp_inet6_event_msgname,
1014         .skb_msgname   = sctp_inet6_skb_msgname,
1015         .af_supported  = sctp_inet6_af_supported,
1016         .cmp_addr      = sctp_inet6_cmp_addr,
1017         .bind_verify   = sctp_inet6_bind_verify,
1018         .send_verify   = sctp_inet6_send_verify,
1019         .supported_addrs = sctp_inet6_supported_addrs,
1020         .create_accept_sk = sctp_v6_create_accept_sk,
1021         .addr_v4map    = sctp_v6_addr_v4map,
1022         .af            = &sctp_af_inet6,
1023 };
1024
1025 /* Initialize IPv6 support and register with socket layer.  */
1026 void sctp_v6_pf_init(void)
1027 {
1028         /* Register the SCTP specific PF_INET6 functions. */
1029         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1030
1031         /* Register the SCTP specific AF_INET6 functions. */
1032         sctp_register_af(&sctp_af_inet6);
1033 }
1034
1035 void sctp_v6_pf_exit(void)
1036 {
1037         list_del(&sctp_af_inet6.list);
1038 }
1039
1040 /* Initialize IPv6 support and register with socket layer.  */
1041 int sctp_v6_protosw_init(void)
1042 {
1043         int rc;
1044
1045         rc = proto_register(&sctpv6_prot, 1);
1046         if (rc)
1047                 return rc;
1048
1049         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1050         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1051         inet6_register_protosw(&sctpv6_stream_protosw);
1052
1053         return 0;
1054 }
1055
1056 void sctp_v6_protosw_exit(void)
1057 {
1058         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1059         inet6_unregister_protosw(&sctpv6_stream_protosw);
1060         proto_unregister(&sctpv6_prot);
1061 }
1062
1063
1064 /* Register with inet6 layer. */
1065 int sctp_v6_add_protocol(void)
1066 {
1067         /* Register notifier for inet6 address additions/deletions. */
1068         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1069
1070         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1071                 return -EAGAIN;
1072
1073         return 0;
1074 }
1075
1076 /* Unregister with inet6 layer. */
1077 void sctp_v6_del_protocol(void)
1078 {
1079         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1080         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1081 }