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, see
  25  * <http://www.gnu.org/licenses/>.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    Le Yanqun             <yanqun.le@nokia.com>
  33  *    Hui Huang             <hui.huang@nokia.com>
  34  *    La Monte H.P. Yarroll <piggy@acm.org>
  35  *    Sridhar Samudrala     <sri@us.ibm.com>
  36  *    Jon Grimm             <jgrimm@us.ibm.com>
  37  *    Ardelle Fan           <ardelle.fan@intel.com>
  38  *
  39  * Based on:
  40  *      linux/net/ipv6/tcp_ipv6.c
  41  */
  42
  43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  44
  45 #include <linux/module.h>
  46 #include <linux/errno.h>
  47 #include <linux/types.h>
  48 #include <linux/socket.h>
  49 #include <linux/sockios.h>
  50 #include <linux/net.h>
  51 #include <linux/in.h>
  52 #include <linux/in6.h>
  53 #include <linux/netdevice.h>
  54 #include <linux/init.h>
  55 #include <linux/ipsec.h>
  56 #include <linux/slab.h>
  57
  58 #include <linux/ipv6.h>
  59 #include <linux/icmpv6.h>
  60 #include <linux/random.h>
  61 #include <linux/seq_file.h>
  62
  63 #include <net/protocol.h>
  64 #include <net/ndisc.h>
  65 #include <net/ip.h>
  66 #include <net/ipv6.h>
  67 #include <net/transp_v6.h>
  68 #include <net/addrconf.h>
  69 #include <net/ip6_route.h>
  70 #include <net/inet_common.h>
  71 #include <net/inet_ecn.h>
  72 #include <net/sctp/sctp.h>
  73
  74 #include <asm/uaccess.h>
  75
  76 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  77                                          union sctp_addr *s2);
  78 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  79                               __be16 port);
  80 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  81                             const union sctp_addr *addr2);
  82
  83 /* Event handler for inet6 address addition/deletion events.
  84  * The sctp_local_addr_list needs to be protocted by a spin lock since
  85  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  86  * time and thus corrupt the list.
  87  * The reader side is protected with RCU.
  88  */
  89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  90                                 void *ptr)
  91 {
  92         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  93         struct sctp_sockaddr_entry *addr = NULL;
  94         struct sctp_sockaddr_entry *temp;
  95         struct net *net = dev_net(ifa->idev->dev);
  96         int found = 0;
  97
  98         switch (ev) {
  99         case NETDEV_UP:
 100                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 101                 if (addr) {
 102                         addr->a.v6.sin6_family = AF_INET6;
 103                         addr->a.v6.sin6_port = 0;
 104                         addr->a.v6.sin6_addr = ifa->addr;
 105                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 106                         addr->valid = 1;
 107                         spin_lock_bh(&net->sctp.local_addr_lock);
 108                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 109                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 110                         spin_unlock_bh(&net->sctp.local_addr_lock);
 111                 }
 112                 break;
 113         case NETDEV_DOWN:
 114                 spin_lock_bh(&net->sctp.local_addr_lock);
 115                 list_for_each_entry_safe(addr, temp,
 116                                         &net->sctp.local_addr_list, list) {
 117                         if (addr->a.sa.sa_family == AF_INET6 &&
 118                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 119                                                 &ifa->addr)) {
 120                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 121                                 found = 1;
 122                                 addr->valid = 0;
 123                                 list_del_rcu(&addr->list);
 124                                 break;
 125                         }
 126                 }
 127                 spin_unlock_bh(&net->sctp.local_addr_lock);
 128                 if (found)
 129                         kfree_rcu(addr, rcu);
 130                 break;
 131         }
 132
 133         return NOTIFY_DONE;
 134 }
 135
 136 static struct notifier_block sctp_inet6addr_notifier = {
 137         .notifier_call = sctp_inet6addr_event,
 138 };
 139
 140 /* ICMP error handler. */
 141 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 142                         u8 type, u8 code, int offset, __be32 info)
 143 {
 144         struct inet6_dev *idev;
 145         struct sock *sk;
 146         struct sctp_association *asoc;
 147         struct sctp_transport *transport;
 148         struct ipv6_pinfo *np;
 149         __u16 saveip, savesctp;
 150         int err;
 151         struct net *net = dev_net(skb->dev);
 152
 153         idev = in6_dev_get(skb->dev);
 154
 155         /* Fix up skb to look at the embedded net header. */
 156         saveip   = skb->network_header;
 157         savesctp = skb->transport_header;
 158         skb_reset_network_header(skb);
 159         skb_set_transport_header(skb, offset);
 160         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 161         /* Put back, the original pointers. */
 162         skb->network_header   = saveip;
 163         skb->transport_header = savesctp;
 164         if (!sk) {
 165                 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_INERRORS);
 166                 goto out;
 167         }
 168
 169         /* Warning:  The sock lock is held.  Remember to call
 170          * sctp_err_finish!
 171          */
 172
 173         switch (type) {
 174         case ICMPV6_PKT_TOOBIG:
 175                 if (ip6_sk_accept_pmtu(sk))
 176                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 177                 goto out_unlock;
 178         case ICMPV6_PARAMPROB:
 179                 if (ICMPV6_UNK_NEXTHDR == code) {
 180                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 181                         goto out_unlock;
 182                 }
 183                 break;
 184         case NDISC_REDIRECT:
 185                 sctp_icmp_redirect(sk, transport, skb);
 186                 goto out_unlock;
 187         default:
 188                 break;
 189         }
 190
 191         np = inet6_sk(sk);
 192         icmpv6_err_convert(type, code, &err);
 193         if (!sock_owned_by_user(sk) && np->recverr) {
 194                 sk->sk_err = err;
 195                 sk->sk_error_report(sk);
 196         } else {  /* Only an error on timeout */
 197                 sk->sk_err_soft = err;
 198         }
 199
 200 out_unlock:
 201         sctp_err_finish(sk, asoc);
 202 out:
 203         if (likely(idev != NULL))
 204                 in6_dev_put(idev);
 205 }
 206
 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 = &transport->fl.u.ip6;
 212         int res;
 213
 214         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 215                  skb->len, &fl6->saddr, &fl6->daddr);
 216
 217         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 218
 219         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 220                 skb->ignore_df = 1;
 221
 222         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 223
 224         rcu_read_lock();
 225         res = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt), np->tclass);
 226         rcu_read_unlock();
 227         return res;
 228 }
 229
 230 /* Returns the dst cache entry for the given source and destination ip
 231  * addresses.
 232  */
 233 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 234                             struct flowi *fl, struct sock *sk)
 235 {
 236         struct sctp_association *asoc = t->asoc;
 237         struct dst_entry *dst = NULL;
 238         struct flowi6 *fl6 = &fl->u.ip6;
 239         struct sctp_bind_addr *bp;
 240         struct ipv6_pinfo *np = inet6_sk(sk);
 241         struct sctp_sockaddr_entry *laddr;
 242         union sctp_addr *baddr = NULL;
 243         union sctp_addr *daddr = &t->ipaddr;
 244         union sctp_addr dst_saddr;
 245         struct in6_addr *final_p, final;
 246         __u8 matchlen = 0;
 247         __u8 bmatchlen;
 248         sctp_scope_t scope;
 249
 250         memset(fl6, 0, sizeof(struct flowi6));
 251         fl6->daddr = daddr->v6.sin6_addr;
 252         fl6->fl6_dport = daddr->v6.sin6_port;
 253         fl6->flowi6_proto = IPPROTO_SCTP;
 254         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 255                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 256
 257         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 258
 259         if (asoc)
 260                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 261
 262         if (saddr) {
 263                 fl6->saddr = saddr->v6.sin6_addr;
 264                 fl6->fl6_sport = saddr->v6.sin6_port;
 265
 266                 pr_debug("src=%pI6 - ", &fl6->saddr);
 267         }
 268
 269         rcu_read_lock();
 270         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 271         rcu_read_unlock();
 272
 273         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 274         if (!asoc || saddr)
 275                 goto out;
 276
 277         bp = &asoc->base.bind_addr;
 278         scope = sctp_scope(daddr);
 279         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 280          * to see if we can use it.
 281          */
 282         if (!IS_ERR(dst)) {
 283                 /* Walk through the bind address list and look for a bind
 284                  * address that matches the source address of the returned dst.
 285                  */
 286                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 287                 rcu_read_lock();
 288                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 289                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 290                             (laddr->state != SCTP_ADDR_SRC &&
 291                              !asoc->src_out_of_asoc_ok))
 292                                 continue;
 293
 294                         /* Do not compare against v4 addrs */
 295                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 296                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 297                                 rcu_read_unlock();
 298                                 goto out;
 299                         }
 300                 }
 301                 rcu_read_unlock();
 302                 /* None of the bound addresses match the source address of the
 303                  * dst. So release it.
 304                  */
 305                 dst_release(dst);
 306                 dst = NULL;
 307         }
 308
 309         /* Walk through the bind address list and try to get the
 310          * best source address for a given destination.
 311          */
 312         rcu_read_lock();
 313         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 314                 if (!laddr->valid)
 315                         continue;
 316                 if ((laddr->state == SCTP_ADDR_SRC) &&
 317                     (laddr->a.sa.sa_family == AF_INET6) &&
 318                     (scope <= sctp_scope(&laddr->a))) {
 319                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 320                         if (!baddr || (matchlen < bmatchlen)) {
 321                                 baddr = &laddr->a;
 322                                 matchlen = bmatchlen;
 323                         }
 324                 }
 325         }
 326         if (baddr) {
 327                 fl6->saddr = baddr->v6.sin6_addr;
 328                 fl6->fl6_sport = baddr->v6.sin6_port;
 329                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 330                 dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 331         }
 332         rcu_read_unlock();
 333
 334 out:
 335         if (!IS_ERR_OR_NULL(dst)) {
 336                 struct rt6_info *rt;
 337
 338                 rt = (struct rt6_info *)dst;
 339                 t->dst = dst;
 340                 t->dst_cookie = rt6_get_cookie(rt);
 341                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 342                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 343                          &fl6->saddr);
 344         } else {
 345                 t->dst = NULL;
 346
 347                 pr_debug("no route\n");
 348         }
 349 }
 350
 351 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 352  * addresses.
 353  */
 354 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 355                                          union sctp_addr *s2)
 356 {
 357         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 358 }
 359
 360 /* Fills in the source address(saddr) based on the destination address(daddr)
 361  * and asoc's bind address list.
 362  */
 363 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 364                               struct sctp_transport *t,
 365                               struct flowi *fl)
 366 {
 367         struct flowi6 *fl6 = &fl->u.ip6;
 368         union sctp_addr *saddr = &t->saddr;
 369
 370         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 371
 372         if (t->dst) {
 373                 saddr->v6.sin6_family = AF_INET6;
 374                 saddr->v6.sin6_addr = fl6->saddr;
 375         }
 376 }
 377
 378 /* Make a copy of all potential local addresses. */
 379 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 380                                   struct net_device *dev)
 381 {
 382         struct inet6_dev *in6_dev;
 383         struct inet6_ifaddr *ifp;
 384         struct sctp_sockaddr_entry *addr;
 385
 386         rcu_read_lock();
 387         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 388                 rcu_read_unlock();
 389                 return;
 390         }
 391
 392         read_lock_bh(&in6_dev->lock);
 393         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 394                 /* Add the address to the local list.  */
 395                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 396                 if (addr) {
 397                         addr->a.v6.sin6_family = AF_INET6;
 398                         addr->a.v6.sin6_port = 0;
 399                         addr->a.v6.sin6_addr = ifp->addr;
 400                         addr->a.v6.sin6_scope_id = dev->ifindex;
 401                         addr->valid = 1;
 402                         INIT_LIST_HEAD(&addr->list);
 403                         list_add_tail(&addr->list, addrlist);
 404                 }
 405         }
 406
 407         read_unlock_bh(&in6_dev->lock);
 408         rcu_read_unlock();
 409 }
 410
 411 /* Initialize a sockaddr_storage from in incoming skb. */
 412 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 413                              int is_saddr)
 414 {
 415         __be16 *port;
 416         struct sctphdr *sh;
 417
 418         port = &addr->v6.sin6_port;
 419         addr->v6.sin6_family = AF_INET6;
 420         addr->v6.sin6_flowinfo = 0; /* FIXME */
 421         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 422
 423         sh = sctp_hdr(skb);
 424         if (is_saddr) {
 425                 *port  = sh->source;
 426                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 427         } else {
 428                 *port = sh->dest;
 429                 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 430         }
 431 }
 432
 433 /* Initialize an sctp_addr from a socket. */
 434 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 435 {
 436         addr->v6.sin6_family = AF_INET6;
 437         addr->v6.sin6_port = 0;
 438         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 439 }
 440
 441 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 442 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 443 {
 444         if (addr->sa.sa_family == AF_INET) {
 445                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 446                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 447                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 448                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 449                         addr->v4.sin_addr.s_addr;
 450         } else {
 451                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 452         }
 453 }
 454
 455 /* Initialize sk->sk_daddr from sctp_addr. */
 456 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 457 {
 458         if (addr->sa.sa_family == AF_INET) {
 459                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 460                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 461                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 462                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 463         } else {
 464                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 465         }
 466 }
 467
 468 /* Initialize a sctp_addr from an address parameter. */
 469 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 470                                     union sctp_addr_param *param,
 471                                     __be16 port, int iif)
 472 {
 473         addr->v6.sin6_family = AF_INET6;
 474         addr->v6.sin6_port = port;
 475         addr->v6.sin6_flowinfo = 0; /* BUG */
 476         addr->v6.sin6_addr = param->v6.addr;
 477         addr->v6.sin6_scope_id = iif;
 478 }
 479
 480 /* Initialize an address parameter from a sctp_addr and return the length
 481  * of the address parameter.
 482  */
 483 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 484                                  union sctp_addr_param *param)
 485 {
 486         int length = sizeof(sctp_ipv6addr_param_t);
 487
 488         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 489         param->v6.param_hdr.length = htons(length);
 490         param->v6.addr = addr->v6.sin6_addr;
 491
 492         return length;
 493 }
 494
 495 /* Initialize a sctp_addr from struct in6_addr. */
 496 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 497                               __be16 port)
 498 {
 499         addr->sa.sa_family = AF_INET6;
 500         addr->v6.sin6_port = port;
 501         addr->v6.sin6_addr = *saddr;
 502 }
 503
 504 /* Compare addresses exactly.
 505  * v4-mapped-v6 is also in consideration.
 506  */
 507 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 508                             const union sctp_addr *addr2)
 509 {
 510         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 511                 if (addr1->sa.sa_family == AF_INET &&
 512                     addr2->sa.sa_family == AF_INET6 &&
 513                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 514                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 515                             addr2->v6.sin6_addr.s6_addr32[3] ==
 516                             addr1->v4.sin_addr.s_addr)
 517                                 return 1;
 518                 }
 519                 if (addr2->sa.sa_family == AF_INET &&
 520                     addr1->sa.sa_family == AF_INET6 &&
 521                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 522                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 523                             addr1->v6.sin6_addr.s6_addr32[3] ==
 524                             addr2->v4.sin_addr.s_addr)
 525                                 return 1;
 526                 }
 527                 return 0;
 528         }
 529         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 530                 return 0;
 531         /* If this is a linklocal address, compare the scope_id. */
 532         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 533                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 534                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 535                         return 0;
 536                 }
 537         }
 538
 539         return 1;
 540 }
 541
 542 /* Initialize addr struct to INADDR_ANY. */
 543 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 544 {
 545         memset(addr, 0x00, sizeof(union sctp_addr));
 546         addr->v6.sin6_family = AF_INET6;
 547         addr->v6.sin6_port = port;
 548 }
 549
 550 /* Is this a wildcard address? */
 551 static int sctp_v6_is_any(const union sctp_addr *addr)
 552 {
 553         return ipv6_addr_any(&addr->v6.sin6_addr);
 554 }
 555
 556 /* Should this be available for binding?   */
 557 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 558 {
 559         int type;
 560         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 561
 562         type = ipv6_addr_type(in6);
 563         if (IPV6_ADDR_ANY == type)
 564                 return 1;
 565         if (type == IPV6_ADDR_MAPPED) {
 566                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 567                         return 0;
 568                 sctp_v6_map_v4(addr);
 569                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 570         }
 571         if (!(type & IPV6_ADDR_UNICAST))
 572                 return 0;
 573
 574         return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
 575 }
 576
 577 /* This function checks if the address is a valid address to be used for
 578  * SCTP.
 579  *
 580  * Output:
 581  * Return 0 - If the address is a non-unicast or an illegal address.
 582  * Return 1 - If the address is a unicast.
 583  */
 584 static int sctp_v6_addr_valid(union sctp_addr *addr,
 585                               struct sctp_sock *sp,
 586                               const struct sk_buff *skb)
 587 {
 588         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 589
 590         /* Support v4-mapped-v6 address. */
 591         if (ret == IPV6_ADDR_MAPPED) {
 592                 /* Note: This routine is used in input, so v4-mapped-v6
 593                  * are disallowed here when there is no sctp_sock.
 594                  */
 595                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 596                         return 0;
 597                 sctp_v6_map_v4(addr);
 598                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 599         }
 600
 601         /* Is this a non-unicast address */
 602         if (!(ret & IPV6_ADDR_UNICAST))
 603                 return 0;
 604
 605         return 1;
 606 }
 607
 608 /* What is the scope of 'addr'?  */
 609 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 610 {
 611         int v6scope;
 612         sctp_scope_t retval;
 613
 614         /* The IPv6 scope is really a set of bit fields.
 615          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 616          */
 617
 618         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 619         switch (v6scope) {
 620         case IFA_HOST:
 621                 retval = SCTP_SCOPE_LOOPBACK;
 622                 break;
 623         case IFA_LINK:
 624                 retval = SCTP_SCOPE_LINK;
 625                 break;
 626         case IFA_SITE:
 627                 retval = SCTP_SCOPE_PRIVATE;
 628                 break;
 629         default:
 630                 retval = SCTP_SCOPE_GLOBAL;
 631                 break;
 632         }
 633
 634         return retval;
 635 }
 636
 637 /* Create and initialize a new sk for the socket to be returned by accept(). */
 638 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 639                                              struct sctp_association *asoc)
 640 {
 641         struct sock *newsk;
 642         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 643         struct sctp6_sock *newsctp6sk;
 644         struct ipv6_txoptions *opt;
 645
 646         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0);
 647         if (!newsk)
 648                 goto out;
 649
 650         sock_init_data(NULL, newsk);
 651
 652         sctp_copy_sock(newsk, sk, asoc);
 653         sock_reset_flag(sk, SOCK_ZAPPED);
 654
 655         newsctp6sk = (struct sctp6_sock *)newsk;
 656         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 657
 658         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 659
 660         newnp = inet6_sk(newsk);
 661
 662         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 663
 664         rcu_read_lock();
 665         opt = rcu_dereference(np->opt);
 666         if (opt)
 667                 opt = ipv6_dup_options(newsk, opt);
 668         RCU_INIT_POINTER(newnp->opt, opt);
 669         rcu_read_unlock();
 670
 671         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 672          * and getpeername().
 673          */
 674         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 675
 676         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 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 /* Format a sockaddr for return to user space. This makes sure the return is
 690  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 691  */
 692 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 693 {
 694         if (sp->v4mapped) {
 695                 if (addr->sa.sa_family == AF_INET)
 696                         sctp_v4_map_v6(addr);
 697         } else {
 698                 if (addr->sa.sa_family == AF_INET6 &&
 699                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 700                         sctp_v6_map_v4(addr);
 701         }
 702
 703         if (addr->sa.sa_family == AF_INET)
 704                 return sizeof(struct sockaddr_in);
 705         return sizeof(struct sockaddr_in6);
 706 }
 707
 708 /* Where did this skb come from?  */
 709 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 710 {
 711         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 712         return opt->iif;
 713 }
 714
 715 /* Was this packet marked by Explicit Congestion Notification? */
 716 static int sctp_v6_is_ce(const struct sk_buff *skb)
 717 {
 718         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 719 }
 720
 721 /* Dump the v6 addr to the seq file. */
 722 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 723 {
 724         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 725 }
 726
 727 static void sctp_v6_ecn_capable(struct sock *sk)
 728 {
 729         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 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         union sctp_addr *addr;
 737         struct sctp_association *asoc;
 738         union sctp_addr *paddr;
 739
 740         if (!msgname)
 741                 return;
 742
 743         addr = (union sctp_addr *)msgname;
 744         asoc = event->asoc;
 745         paddr = &asoc->peer.primary_addr;
 746
 747         if (paddr->sa.sa_family == AF_INET) {
 748                 addr->v4.sin_family = AF_INET;
 749                 addr->v4.sin_port = htons(asoc->peer.port);
 750                 addr->v4.sin_addr = paddr->v4.sin_addr;
 751         } else {
 752                 addr->v6.sin6_family = AF_INET6;
 753                 addr->v6.sin6_flowinfo = 0;
 754                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 755                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 756                 else
 757                         addr->v6.sin6_scope_id = 0;
 758                 addr->v6.sin6_port = htons(asoc->peer.port);
 759                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 760         }
 761
 762         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 763 }
 764
 765 /* Initialize a msg_name from an inbound skb. */
 766 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 767                                    int *addr_len)
 768 {
 769         union sctp_addr *addr;
 770         struct sctphdr *sh;
 771
 772         if (!msgname)
 773                 return;
 774
 775         addr = (union sctp_addr *)msgname;
 776         sh = sctp_hdr(skb);
 777
 778         if (ip_hdr(skb)->version == 4) {
 779                 addr->v4.sin_family = AF_INET;
 780                 addr->v4.sin_port = sh->source;
 781                 addr->v4.sin_addr.s_addr =  ip_hdr(skb)->saddr;
 782         } else {
 783                 addr->v6.sin6_family = AF_INET6;
 784                 addr->v6.sin6_flowinfo = 0;
 785                 addr->v6.sin6_port = sh->source;
 786                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 787                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 788                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 789                         addr->v6.sin6_scope_id = ev->iif;
 790                 }
 791         }
 792
 793         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 794 }
 795
 796 /* Do we support this AF? */
 797 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 798 {
 799         switch (family) {
 800         case AF_INET6:
 801                 return 1;
 802         /* v4-mapped-v6 addresses */
 803         case AF_INET:
 804                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 805                         return 1;
 806         default:
 807                 return 0;
 808         }
 809 }
 810
 811 /* Address matching with wildcards allowed.  This extra level
 812  * of indirection lets us choose whether a PF_INET6 should
 813  * disallow any v4 addresses if we so choose.
 814  */
 815 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 816                                const union sctp_addr *addr2,
 817                                struct sctp_sock *opt)
 818 {
 819         struct sctp_af *af1, *af2;
 820         struct sock *sk = sctp_opt2sk(opt);
 821
 822         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 823         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 824
 825         if (!af1 || !af2)
 826                 return 0;
 827
 828         /* If the socket is IPv6 only, v4 addrs will not match */
 829         if (__ipv6_only_sock(sk) && af1 != af2)
 830                 return 0;
 831
 832         /* Today, wildcard AF_INET/AF_INET6. */
 833         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 834                 return 1;
 835
 836         if (addr1->sa.sa_family != addr2->sa.sa_family)
 837                 return 0;
 838
 839         return af1->cmp_addr(addr1, addr2);
 840 }
 841
 842 /* Verify that the provided sockaddr looks bindable.   Common verification,
 843  * has already been taken care of.
 844  */
 845 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 846 {
 847         struct sctp_af *af;
 848
 849         /* ASSERT: address family has already been verified. */
 850         if (addr->sa.sa_family != AF_INET6)
 851                 af = sctp_get_af_specific(addr->sa.sa_family);
 852         else {
 853                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 854                 struct net_device *dev;
 855
 856                 if (type & IPV6_ADDR_LINKLOCAL) {
 857                         struct net *net;
 858                         if (!addr->v6.sin6_scope_id)
 859                                 return 0;
 860                         net = sock_net(&opt->inet.sk);
 861                         rcu_read_lock();
 862                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 863                         if (!dev ||
 864                             !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 865                                 rcu_read_unlock();
 866                                 return 0;
 867                         }
 868                         rcu_read_unlock();
 869                 }
 870
 871                 af = opt->pf->af;
 872         }
 873         return af->available(addr, opt);
 874 }
 875
 876 /* Verify that the provided sockaddr looks sendable.   Common verification,
 877  * has already been taken care of.
 878  */
 879 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 880 {
 881         struct sctp_af *af = NULL;
 882
 883         /* ASSERT: address family has already been verified. */
 884         if (addr->sa.sa_family != AF_INET6)
 885                 af = sctp_get_af_specific(addr->sa.sa_family);
 886         else {
 887                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 888                 struct net_device *dev;
 889
 890                 if (type & IPV6_ADDR_LINKLOCAL) {
 891                         if (!addr->v6.sin6_scope_id)
 892                                 return 0;
 893                         rcu_read_lock();
 894                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 895                                                    addr->v6.sin6_scope_id);
 896                         rcu_read_unlock();
 897                         if (!dev)
 898                                 return 0;
 899                 }
 900                 af = opt->pf->af;
 901         }
 902
 903         return af != NULL;
 904 }
 905
 906 /* Fill in Supported Address Type information for INIT and INIT-ACK
 907  * chunks.   Note: In the future, we may want to look at sock options
 908  * to determine whether a PF_INET6 socket really wants to have IPV4
 909  * addresses.
 910  * Returns number of addresses supported.
 911  */
 912 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 913                                       __be16 *types)
 914 {
 915         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 916         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 917                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 918                 return 2;
 919         }
 920         return 1;
 921 }
 922
 923 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 924 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 925                         int *uaddr_len, int peer)
 926 {
 927         int rc;
 928
 929         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 930
 931         if (rc != 0)
 932                 return rc;
 933
 934         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 935                                           (union sctp_addr *)uaddr);
 936
 937         return rc;
 938 }
 939
 940 static const struct proto_ops inet6_seqpacket_ops = {
 941         .family            = PF_INET6,
 942         .owner             = THIS_MODULE,
 943         .release           = inet6_release,
 944         .bind              = inet6_bind,
 945         .connect           = inet_dgram_connect,
 946         .socketpair        = sock_no_socketpair,
 947         .accept            = inet_accept,
 948         .getname           = sctp_getname,
 949         .poll              = sctp_poll,
 950         .ioctl             = inet6_ioctl,
 951         .listen            = sctp_inet_listen,
 952         .shutdown          = inet_shutdown,
 953         .setsockopt        = sock_common_setsockopt,
 954         .getsockopt        = sock_common_getsockopt,
 955         .sendmsg           = inet_sendmsg,
 956         .recvmsg           = sock_common_recvmsg,
 957         .mmap              = sock_no_mmap,
 958 #ifdef CONFIG_COMPAT
 959         .compat_setsockopt = compat_sock_common_setsockopt,
 960         .compat_getsockopt = compat_sock_common_getsockopt,
 961 #endif
 962 };
 963
 964 static struct inet_protosw sctpv6_seqpacket_protosw = {
 965         .type          = SOCK_SEQPACKET,
 966         .protocol      = IPPROTO_SCTP,
 967         .prot          = &sctpv6_prot,
 968         .ops           = &inet6_seqpacket_ops,
 969         .flags         = SCTP_PROTOSW_FLAG
 970 };
 971 static struct inet_protosw sctpv6_stream_protosw = {
 972         .type          = SOCK_STREAM,
 973         .protocol      = IPPROTO_SCTP,
 974         .prot          = &sctpv6_prot,
 975         .ops           = &inet6_seqpacket_ops,
 976         .flags         = SCTP_PROTOSW_FLAG,
 977 };
 978
 979 static int sctp6_rcv(struct sk_buff *skb)
 980 {
 981         return sctp_rcv(skb) ? -1 : 0;
 982 }
 983
 984 static const struct inet6_protocol sctpv6_protocol = {
 985         .handler      = sctp6_rcv,
 986         .err_handler  = sctp_v6_err,
 987         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 988 };
 989
 990 static struct sctp_af sctp_af_inet6 = {
 991         .sa_family         = AF_INET6,
 992         .sctp_xmit         = sctp_v6_xmit,
 993         .setsockopt        = ipv6_setsockopt,
 994         .getsockopt        = ipv6_getsockopt,
 995         .get_dst           = sctp_v6_get_dst,
 996         .get_saddr         = sctp_v6_get_saddr,
 997         .copy_addrlist     = sctp_v6_copy_addrlist,
 998         .from_skb          = sctp_v6_from_skb,
 999         .from_sk           = sctp_v6_from_sk,
1000         .from_addr_param   = sctp_v6_from_addr_param,
1001         .to_addr_param     = sctp_v6_to_addr_param,
1002         .cmp_addr          = sctp_v6_cmp_addr,
1003         .scope             = sctp_v6_scope,
1004         .addr_valid        = sctp_v6_addr_valid,
1005         .inaddr_any        = sctp_v6_inaddr_any,
1006         .is_any            = sctp_v6_is_any,
1007         .available         = sctp_v6_available,
1008         .skb_iif           = sctp_v6_skb_iif,
1009         .is_ce             = sctp_v6_is_ce,
1010         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1011         .ecn_capable       = sctp_v6_ecn_capable,
1012         .net_header_len    = sizeof(struct ipv6hdr),
1013         .sockaddr_len      = sizeof(struct sockaddr_in6),
1014 #ifdef CONFIG_COMPAT
1015         .compat_setsockopt = compat_ipv6_setsockopt,
1016         .compat_getsockopt = compat_ipv6_getsockopt,
1017 #endif
1018 };
1019
1020 static struct sctp_pf sctp_pf_inet6 = {
1021         .event_msgname = sctp_inet6_event_msgname,
1022         .skb_msgname   = sctp_inet6_skb_msgname,
1023         .af_supported  = sctp_inet6_af_supported,
1024         .cmp_addr      = sctp_inet6_cmp_addr,
1025         .bind_verify   = sctp_inet6_bind_verify,
1026         .send_verify   = sctp_inet6_send_verify,
1027         .supported_addrs = sctp_inet6_supported_addrs,
1028         .create_accept_sk = sctp_v6_create_accept_sk,
1029         .addr_to_user  = sctp_v6_addr_to_user,
1030         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1031         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1032         .af            = &sctp_af_inet6,
1033 };
1034
1035 /* Initialize IPv6 support and register with socket layer.  */
1036 void sctp_v6_pf_init(void)
1037 {
1038         /* Register the SCTP specific PF_INET6 functions. */
1039         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1040
1041         /* Register the SCTP specific AF_INET6 functions. */
1042         sctp_register_af(&sctp_af_inet6);
1043 }
1044
1045 void sctp_v6_pf_exit(void)
1046 {
1047         list_del(&sctp_af_inet6.list);
1048 }
1049
1050 /* Initialize IPv6 support and register with socket layer.  */
1051 int sctp_v6_protosw_init(void)
1052 {
1053         int rc;
1054
1055         rc = proto_register(&sctpv6_prot, 1);
1056         if (rc)
1057                 return rc;
1058
1059         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1060         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1061         inet6_register_protosw(&sctpv6_stream_protosw);
1062
1063         return 0;
1064 }
1065
1066 void sctp_v6_protosw_exit(void)
1067 {
1068         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1069         inet6_unregister_protosw(&sctpv6_stream_protosw);
1070         proto_unregister(&sctpv6_prot);
1071 }
1072
1073
1074 /* Register with inet6 layer. */
1075 int sctp_v6_add_protocol(void)
1076 {
1077         /* Register notifier for inet6 address additions/deletions. */
1078         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1079
1080         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1081                 return -EAGAIN;
1082
1083         return 0;
1084 }
1085
1086 /* Unregister with inet6 layer. */
1087 void sctp_v6_del_protocol(void)
1088 {
1089         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1090         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1091 }