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                         call_rcu(&addr->rcu, sctp_local_addr_free);
 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 struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 251                                          union sctp_addr *daddr,
 252                                          union sctp_addr *saddr,
 253                                          struct flowi *fl,
 254                                          struct sock *sk)
 255 {
 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 dst_saddr;
 262         __u8 matchlen = 0;
 263         __u8 bmatchlen;
 264         sctp_scope_t scope;
 265
 266         memset(fl6, 0, sizeof(struct flowi6));
 267         ipv6_addr_copy(&fl6->daddr, &daddr->v6.sin6_addr);
 268         fl6->fl6_dport = daddr->v6.sin6_port;
 269         fl6->flowi6_proto = IPPROTO_SCTP;
 270         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 271                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 272
 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                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 347                         &rt->rt6i_dst.addr, &fl6->saddr);
 348                 return dst;
 349         }
 350         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 351         return NULL;
 352 }
 353
 354 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 355  * addresses.
 356  */
 357 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 358                                          union sctp_addr *s2)
 359 {
 360         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 361 }
 362
 363 /* Fills in the source address(saddr) based on the destination address(daddr)
 364  * and asoc's bind address list.
 365  */
 366 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 367                               struct sctp_transport *t,
 368                               union sctp_addr *daddr,
 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 daddr:%pI6 ",
 375                           __func__, t->asoc, t->dst, &daddr->v6.sin6_addr);
 376
 377
 378         if (t->dst) {
 379                 saddr->v6.sin6_family = AF_INET6;
 380                 ipv6_addr_copy(&saddr->v6.sin6_addr, &fl6->saddr);
 381         }
 382 }
 383
 384 /* Make a copy of all potential local addresses. */
 385 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 386                                   struct net_device *dev)
 387 {
 388         struct inet6_dev *in6_dev;
 389         struct inet6_ifaddr *ifp;
 390         struct sctp_sockaddr_entry *addr;
 391
 392         rcu_read_lock();
 393         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 394                 rcu_read_unlock();
 395                 return;
 396         }
 397
 398         read_lock_bh(&in6_dev->lock);
 399         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 400                 /* Add the address to the local list.  */
 401                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 402                 if (addr) {
 403                         addr->a.v6.sin6_family = AF_INET6;
 404                         addr->a.v6.sin6_port = 0;
 405                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifp->addr);
 406                         addr->a.v6.sin6_scope_id = dev->ifindex;
 407                         addr->valid = 1;
 408                         INIT_LIST_HEAD(&addr->list);
 409                         list_add_tail(&addr->list, addrlist);
 410                 }
 411         }
 412
 413         read_unlock_bh(&in6_dev->lock);
 414         rcu_read_unlock();
 415 }
 416
 417 /* Initialize a sockaddr_storage from in incoming skb. */
 418 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 419                              int is_saddr)
 420 {
 421         void *from;
 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                 from = &ipv6_hdr(skb)->saddr;
 434         } else {
 435                 *port = sh->dest;
 436                 from = &ipv6_hdr(skb)->daddr;
 437         }
 438         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 439 }
 440
 441 /* Initialize an sctp_addr from a socket. */
 442 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 443 {
 444         addr->v6.sin6_family = AF_INET6;
 445         addr->v6.sin6_port = 0;
 446         ipv6_addr_copy(&addr->v6.sin6_addr, &inet6_sk(sk)->rcv_saddr);
 447 }
 448
 449 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 450 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 451 {
 452         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 453                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 454                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 455                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 456                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 457                         addr->v4.sin_addr.s_addr;
 458         } else {
 459                 ipv6_addr_copy(&inet6_sk(sk)->rcv_saddr, &addr->v6.sin6_addr);
 460         }
 461 }
 462
 463 /* Initialize sk->sk_daddr from sctp_addr. */
 464 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 465 {
 466         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 467                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 468                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 469                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 470                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 471         } else {
 472                 ipv6_addr_copy(&inet6_sk(sk)->daddr, &addr->v6.sin6_addr);
 473         }
 474 }
 475
 476 /* Initialize a sctp_addr from an address parameter. */
 477 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 478                                     union sctp_addr_param *param,
 479                                     __be16 port, int iif)
 480 {
 481         addr->v6.sin6_family = AF_INET6;
 482         addr->v6.sin6_port = port;
 483         addr->v6.sin6_flowinfo = 0; /* BUG */
 484         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 485         addr->v6.sin6_scope_id = iif;
 486 }
 487
 488 /* Initialize an address parameter from a sctp_addr and return the length
 489  * of the address parameter.
 490  */
 491 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 492                                  union sctp_addr_param *param)
 493 {
 494         int length = sizeof(sctp_ipv6addr_param_t);
 495
 496         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 497         param->v6.param_hdr.length = htons(length);
 498         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 499
 500         return length;
 501 }
 502
 503 /* Initialize a sctp_addr from struct in6_addr. */
 504 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 505                               __be16 port)
 506 {
 507         addr->sa.sa_family = AF_INET6;
 508         addr->v6.sin6_port = port;
 509         ipv6_addr_copy(&addr->v6.sin6_addr, saddr);
 510 }
 511
 512 /* Compare addresses exactly.
 513  * v4-mapped-v6 is also in consideration.
 514  */
 515 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 516                             const union sctp_addr *addr2)
 517 {
 518         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 519                 if (addr1->sa.sa_family == AF_INET &&
 520                     addr2->sa.sa_family == AF_INET6 &&
 521                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 522                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 523                             addr2->v6.sin6_addr.s6_addr32[3] ==
 524                             addr1->v4.sin_addr.s_addr)
 525                                 return 1;
 526                 }
 527                 if (addr2->sa.sa_family == AF_INET &&
 528                     addr1->sa.sa_family == AF_INET6 &&
 529                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 530                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 531                             addr1->v6.sin6_addr.s6_addr32[3] ==
 532                             addr2->v4.sin_addr.s_addr)
 533                                 return 1;
 534                 }
 535                 return 0;
 536         }
 537         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 538                 return 0;
 539         /* If this is a linklocal address, compare the scope_id. */
 540         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 541                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 542                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 543                         return 0;
 544                 }
 545         }
 546
 547         return 1;
 548 }
 549
 550 /* Initialize addr struct to INADDR_ANY. */
 551 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 552 {
 553         memset(addr, 0x00, sizeof(union sctp_addr));
 554         addr->v6.sin6_family = AF_INET6;
 555         addr->v6.sin6_port = port;
 556 }
 557
 558 /* Is this a wildcard address? */
 559 static int sctp_v6_is_any(const union sctp_addr *addr)
 560 {
 561         return ipv6_addr_any(&addr->v6.sin6_addr);
 562 }
 563
 564 /* Should this be available for binding?   */
 565 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 566 {
 567         int type;
 568         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 569
 570         type = ipv6_addr_type(in6);
 571         if (IPV6_ADDR_ANY == type)
 572                 return 1;
 573         if (type == IPV6_ADDR_MAPPED) {
 574                 if (sp && !sp->v4mapped)
 575                         return 0;
 576                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 577                         return 0;
 578                 sctp_v6_map_v4(addr);
 579                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 580         }
 581         if (!(type & IPV6_ADDR_UNICAST))
 582                 return 0;
 583
 584         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 585 }
 586
 587 /* This function checks if the address is a valid address to be used for
 588  * SCTP.
 589  *
 590  * Output:
 591  * Return 0 - If the address is a non-unicast or an illegal address.
 592  * Return 1 - If the address is a unicast.
 593  */
 594 static int sctp_v6_addr_valid(union sctp_addr *addr,
 595                               struct sctp_sock *sp,
 596                               const struct sk_buff *skb)
 597 {
 598         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 599
 600         /* Support v4-mapped-v6 address. */
 601         if (ret == IPV6_ADDR_MAPPED) {
 602                 /* Note: This routine is used in input, so v4-mapped-v6
 603                  * are disallowed here when there is no sctp_sock.
 604                  */
 605                 if (!sp || !sp->v4mapped)
 606                         return 0;
 607                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 608                         return 0;
 609                 sctp_v6_map_v4(addr);
 610                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 611         }
 612
 613         /* Is this a non-unicast address */
 614         if (!(ret & IPV6_ADDR_UNICAST))
 615                 return 0;
 616
 617         return 1;
 618 }
 619
 620 /* What is the scope of 'addr'?  */
 621 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 622 {
 623         int v6scope;
 624         sctp_scope_t retval;
 625
 626         /* The IPv6 scope is really a set of bit fields.
 627          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 628          */
 629
 630         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 631         switch (v6scope) {
 632         case IFA_HOST:
 633                 retval = SCTP_SCOPE_LOOPBACK;
 634                 break;
 635         case IFA_LINK:
 636                 retval = SCTP_SCOPE_LINK;
 637                 break;
 638         case IFA_SITE:
 639                 retval = SCTP_SCOPE_PRIVATE;
 640                 break;
 641         default:
 642                 retval = SCTP_SCOPE_GLOBAL;
 643                 break;
 644         }
 645
 646         return retval;
 647 }
 648
 649 /* Create and initialize a new sk for the socket to be returned by accept(). */
 650 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 651                                              struct sctp_association *asoc)
 652 {
 653         struct sock *newsk;
 654         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 655         struct sctp6_sock *newsctp6sk;
 656
 657         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 658         if (!newsk)
 659                 goto out;
 660
 661         sock_init_data(NULL, newsk);
 662
 663         sctp_copy_sock(newsk, sk, asoc);
 664         sock_reset_flag(sk, SOCK_ZAPPED);
 665
 666         newsctp6sk = (struct sctp6_sock *)newsk;
 667         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 668
 669         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 670
 671         newnp = inet6_sk(newsk);
 672
 673         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 674
 675         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 676          * and getpeername().
 677          */
 678         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 679
 680         sk_refcnt_debug_inc(newsk);
 681
 682         if (newsk->sk_prot->init(newsk)) {
 683                 sk_common_release(newsk);
 684                 newsk = NULL;
 685         }
 686
 687 out:
 688         return newsk;
 689 }
 690
 691 /* Map v4 address to mapped v6 address */
 692 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 693 {
 694         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 695                 sctp_v4_map_v6(addr);
 696 }
 697
 698 /* Where did this skb come from?  */
 699 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 700 {
 701         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 702         return opt->iif;
 703 }
 704
 705 /* Was this packet marked by Explicit Congestion Notification? */
 706 static int sctp_v6_is_ce(const struct sk_buff *skb)
 707 {
 708         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 709 }
 710
 711 /* Dump the v6 addr to the seq file. */
 712 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 713 {
 714         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 715 }
 716
 717 static void sctp_v6_ecn_capable(struct sock *sk)
 718 {
 719         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 720 }
 721
 722 /* Initialize a PF_INET6 socket msg_name. */
 723 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 724 {
 725         struct sockaddr_in6 *sin6;
 726
 727         sin6 = (struct sockaddr_in6 *)msgname;
 728         sin6->sin6_family = AF_INET6;
 729         sin6->sin6_flowinfo = 0;
 730         sin6->sin6_scope_id = 0; /*FIXME */
 731         *addr_len = sizeof(struct sockaddr_in6);
 732 }
 733
 734 /* Initialize a PF_INET msgname from a ulpevent. */
 735 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 736                                      char *msgname, int *addrlen)
 737 {
 738         struct sockaddr_in6 *sin6, *sin6from;
 739
 740         if (msgname) {
 741                 union sctp_addr *addr;
 742                 struct sctp_association *asoc;
 743
 744                 asoc = event->asoc;
 745                 sctp_inet6_msgname(msgname, addrlen);
 746                 sin6 = (struct sockaddr_in6 *)msgname;
 747                 sin6->sin6_port = htons(asoc->peer.port);
 748                 addr = &asoc->peer.primary_addr;
 749
 750                 /* Note: If we go to a common v6 format, this code
 751                  * will change.
 752                  */
 753
 754                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 755                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 756                     AF_INET == addr->sa.sa_family) {
 757                         sctp_v4_map_v6((union sctp_addr *)sin6);
 758                         sin6->sin6_addr.s6_addr32[3] =
 759                                 addr->v4.sin_addr.s_addr;
 760                         return;
 761                 }
 762
 763                 sin6from = &asoc->peer.primary_addr.v6;
 764                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 765                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 766                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 767         }
 768 }
 769
 770 /* Initialize a msg_name from an inbound skb. */
 771 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 772                                    int *addr_len)
 773 {
 774         struct sctphdr *sh;
 775         struct sockaddr_in6 *sin6;
 776
 777         if (msgname) {
 778                 sctp_inet6_msgname(msgname, addr_len);
 779                 sin6 = (struct sockaddr_in6 *)msgname;
 780                 sh = sctp_hdr(skb);
 781                 sin6->sin6_port = sh->source;
 782
 783                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 784                 if (sctp_sk(skb->sk)->v4mapped &&
 785                     ip_hdr(skb)->version == 4) {
 786                         sctp_v4_map_v6((union sctp_addr *)sin6);
 787                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 788                         return;
 789                 }
 790
 791                 /* Otherwise, just copy the v6 address. */
 792                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 793                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 794                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 795                         sin6->sin6_scope_id = ev->iif;
 796                 }
 797         }
 798 }
 799
 800 /* Do we support this AF? */
 801 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 802 {
 803         switch (family) {
 804         case AF_INET6:
 805                 return 1;
 806         /* v4-mapped-v6 addresses */
 807         case AF_INET:
 808                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 809                         return 1;
 810         default:
 811                 return 0;
 812         }
 813 }
 814
 815 /* Address matching with wildcards allowed.  This extra level
 816  * of indirection lets us choose whether a PF_INET6 should
 817  * disallow any v4 addresses if we so choose.
 818  */
 819 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 820                                const union sctp_addr *addr2,
 821                                struct sctp_sock *opt)
 822 {
 823         struct sctp_af *af1, *af2;
 824         struct sock *sk = sctp_opt2sk(opt);
 825
 826         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 827         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 828
 829         if (!af1 || !af2)
 830                 return 0;
 831
 832         /* If the socket is IPv6 only, v4 addrs will not match */
 833         if (__ipv6_only_sock(sk) && af1 != af2)
 834                 return 0;
 835
 836         /* Today, wildcard AF_INET/AF_INET6. */
 837         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 838                 return 1;
 839
 840         if (addr1->sa.sa_family != addr2->sa.sa_family)
 841                 return 0;
 842
 843         return af1->cmp_addr(addr1, addr2);
 844 }
 845
 846 /* Verify that the provided sockaddr looks bindable.   Common verification,
 847  * has already been taken care of.
 848  */
 849 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 850 {
 851         struct sctp_af *af;
 852
 853         /* ASSERT: address family has already been verified. */
 854         if (addr->sa.sa_family != AF_INET6)
 855                 af = sctp_get_af_specific(addr->sa.sa_family);
 856         else {
 857                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 858                 struct net_device *dev;
 859
 860                 if (type & IPV6_ADDR_LINKLOCAL) {
 861                         if (!addr->v6.sin6_scope_id)
 862                                 return 0;
 863                         rcu_read_lock();
 864                         dev = dev_get_by_index_rcu(&init_net,
 865                                                    addr->v6.sin6_scope_id);
 866                         if (!dev ||
 867                             !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 868                                            dev, 0)) {
 869                                 rcu_read_unlock();
 870                                 return 0;
 871                         }
 872                         rcu_read_unlock();
 873                 } else if (type == IPV6_ADDR_MAPPED) {
 874                         if (!opt->v4mapped)
 875                                 return 0;
 876                 }
 877
 878                 af = opt->pf->af;
 879         }
 880         return af->available(addr, opt);
 881 }
 882
 883 /* Verify that the provided sockaddr looks sendable.   Common verification,
 884  * has already been taken care of.
 885  */
 886 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 887 {
 888         struct sctp_af *af = NULL;
 889
 890         /* ASSERT: address family has already been verified. */
 891         if (addr->sa.sa_family != AF_INET6)
 892                 af = sctp_get_af_specific(addr->sa.sa_family);
 893         else {
 894                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 895                 struct net_device *dev;
 896
 897                 if (type & IPV6_ADDR_LINKLOCAL) {
 898                         if (!addr->v6.sin6_scope_id)
 899                                 return 0;
 900                         rcu_read_lock();
 901                         dev = dev_get_by_index_rcu(&init_net,
 902                                                    addr->v6.sin6_scope_id);
 903                         rcu_read_unlock();
 904                         if (!dev)
 905                                 return 0;
 906                 }
 907                 af = opt->pf->af;
 908         }
 909
 910         return af != NULL;
 911 }
 912
 913 /* Fill in Supported Address Type information for INIT and INIT-ACK
 914  * chunks.   Note: In the future, we may want to look at sock options
 915  * to determine whether a PF_INET6 socket really wants to have IPV4
 916  * addresses.
 917  * Returns number of addresses supported.
 918  */
 919 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 920                                       __be16 *types)
 921 {
 922         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 923         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 924                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 925                 return 2;
 926         }
 927         return 1;
 928 }
 929
 930 static const struct proto_ops inet6_seqpacket_ops = {
 931         .family            = PF_INET6,
 932         .owner             = THIS_MODULE,
 933         .release           = inet6_release,
 934         .bind              = inet6_bind,
 935         .connect           = inet_dgram_connect,
 936         .socketpair        = sock_no_socketpair,
 937         .accept            = inet_accept,
 938         .getname           = inet6_getname,
 939         .poll              = sctp_poll,
 940         .ioctl             = inet6_ioctl,
 941         .listen            = sctp_inet_listen,
 942         .shutdown          = inet_shutdown,
 943         .setsockopt        = sock_common_setsockopt,
 944         .getsockopt        = sock_common_getsockopt,
 945         .sendmsg           = inet_sendmsg,
 946         .recvmsg           = sock_common_recvmsg,
 947         .mmap              = sock_no_mmap,
 948 #ifdef CONFIG_COMPAT
 949         .compat_setsockopt = compat_sock_common_setsockopt,
 950         .compat_getsockopt = compat_sock_common_getsockopt,
 951 #endif
 952 };
 953
 954 static struct inet_protosw sctpv6_seqpacket_protosw = {
 955         .type          = SOCK_SEQPACKET,
 956         .protocol      = IPPROTO_SCTP,
 957         .prot          = &sctpv6_prot,
 958         .ops           = &inet6_seqpacket_ops,
 959         .no_check      = 0,
 960         .flags         = SCTP_PROTOSW_FLAG
 961 };
 962 static struct inet_protosw sctpv6_stream_protosw = {
 963         .type          = SOCK_STREAM,
 964         .protocol      = IPPROTO_SCTP,
 965         .prot          = &sctpv6_prot,
 966         .ops           = &inet6_seqpacket_ops,
 967         .no_check      = 0,
 968         .flags         = SCTP_PROTOSW_FLAG,
 969 };
 970
 971 static int sctp6_rcv(struct sk_buff *skb)
 972 {
 973         return sctp_rcv(skb) ? -1 : 0;
 974 }
 975
 976 static const struct inet6_protocol sctpv6_protocol = {
 977         .handler      = sctp6_rcv,
 978         .err_handler  = sctp_v6_err,
 979         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 980 };
 981
 982 static struct sctp_af sctp_af_inet6 = {
 983         .sa_family         = AF_INET6,
 984         .sctp_xmit         = sctp_v6_xmit,
 985         .setsockopt        = ipv6_setsockopt,
 986         .getsockopt        = ipv6_getsockopt,
 987         .get_dst           = sctp_v6_get_dst,
 988         .get_saddr         = sctp_v6_get_saddr,
 989         .copy_addrlist     = sctp_v6_copy_addrlist,
 990         .from_skb          = sctp_v6_from_skb,
 991         .from_sk           = sctp_v6_from_sk,
 992         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 993         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 994         .from_addr_param   = sctp_v6_from_addr_param,
 995         .to_addr_param     = sctp_v6_to_addr_param,
 996         .cmp_addr          = sctp_v6_cmp_addr,
 997         .scope             = sctp_v6_scope,
 998         .addr_valid        = sctp_v6_addr_valid,
 999         .inaddr_any        = sctp_v6_inaddr_any,
1000         .is_any            = sctp_v6_is_any,
1001         .available         = sctp_v6_available,
1002         .skb_iif           = sctp_v6_skb_iif,
1003         .is_ce             = sctp_v6_is_ce,
1004         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1005         .ecn_capable       = sctp_v6_ecn_capable,
1006         .net_header_len    = sizeof(struct ipv6hdr),
1007         .sockaddr_len      = sizeof(struct sockaddr_in6),
1008 #ifdef CONFIG_COMPAT
1009         .compat_setsockopt = compat_ipv6_setsockopt,
1010         .compat_getsockopt = compat_ipv6_getsockopt,
1011 #endif
1012 };
1013
1014 static struct sctp_pf sctp_pf_inet6 = {
1015         .event_msgname = sctp_inet6_event_msgname,
1016         .skb_msgname   = sctp_inet6_skb_msgname,
1017         .af_supported  = sctp_inet6_af_supported,
1018         .cmp_addr      = sctp_inet6_cmp_addr,
1019         .bind_verify   = sctp_inet6_bind_verify,
1020         .send_verify   = sctp_inet6_send_verify,
1021         .supported_addrs = sctp_inet6_supported_addrs,
1022         .create_accept_sk = sctp_v6_create_accept_sk,
1023         .addr_v4map    = sctp_v6_addr_v4map,
1024         .af            = &sctp_af_inet6,
1025 };
1026
1027 /* Initialize IPv6 support and register with socket layer.  */
1028 void sctp_v6_pf_init(void)
1029 {
1030         /* Register the SCTP specific PF_INET6 functions. */
1031         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1032
1033         /* Register the SCTP specific AF_INET6 functions. */
1034         sctp_register_af(&sctp_af_inet6);
1035 }
1036
1037 void sctp_v6_pf_exit(void)
1038 {
1039         list_del(&sctp_af_inet6.list);
1040 }
1041
1042 /* Initialize IPv6 support and register with socket layer.  */
1043 int sctp_v6_protosw_init(void)
1044 {
1045         int rc;
1046
1047         rc = proto_register(&sctpv6_prot, 1);
1048         if (rc)
1049                 return rc;
1050
1051         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1052         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1053         inet6_register_protosw(&sctpv6_stream_protosw);
1054
1055         return 0;
1056 }
1057
1058 void sctp_v6_protosw_exit(void)
1059 {
1060         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1061         inet6_unregister_protosw(&sctpv6_stream_protosw);
1062         proto_unregister(&sctpv6_prot);
1063 }
1064
1065
1066 /* Register with inet6 layer. */
1067 int sctp_v6_add_protocol(void)
1068 {
1069         /* Register notifier for inet6 address additions/deletions. */
1070         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1071
1072         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1073                 return -EAGAIN;
1074
1075         return 0;
1076 }
1077
1078 /* Unregister with inet6 layer. */
1079 void sctp_v6_del_protocol(void)
1080 {
1081         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1082         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1083 }