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 <linux/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(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, transport);
 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, sk->sk_mark, rcu_dereference(np->opt),
 226                        np->tclass);
 227         rcu_read_unlock();
 228         return res;
 229 }
 230
 231 /* Returns the dst cache entry for the given source and destination ip
 232  * addresses.
 233  */
 234 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 235                             struct flowi *fl, struct sock *sk)
 236 {
 237         struct sctp_association *asoc = t->asoc;
 238         struct dst_entry *dst = NULL;
 239         struct flowi6 *fl6 = &fl->u.ip6;
 240         struct sctp_bind_addr *bp;
 241         struct ipv6_pinfo *np = inet6_sk(sk);
 242         struct sctp_sockaddr_entry *laddr;
 243         union sctp_addr *daddr = &t->ipaddr;
 244         union sctp_addr dst_saddr;
 245         struct in6_addr *final_p, final;
 246         enum sctp_scope scope;
 247         __u8 matchlen = 0;
 248
 249         memset(fl6, 0, sizeof(struct flowi6));
 250         fl6->daddr = daddr->v6.sin6_addr;
 251         fl6->fl6_dport = daddr->v6.sin6_port;
 252         fl6->flowi6_proto = IPPROTO_SCTP;
 253         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 254                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 255         else if (asoc)
 256                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 257
 258         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 259
 260         if (asoc)
 261                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 262
 263         if (saddr) {
 264                 fl6->saddr = saddr->v6.sin6_addr;
 265                 fl6->fl6_sport = saddr->v6.sin6_port;
 266
 267                 pr_debug("src=%pI6 - ", &fl6->saddr);
 268         }
 269
 270         rcu_read_lock();
 271         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 272         rcu_read_unlock();
 273
 274         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 275         if (!asoc || saddr)
 276                 goto out;
 277
 278         bp = &asoc->base.bind_addr;
 279         scope = sctp_scope(daddr);
 280         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 281          * to see if we can use it.
 282          */
 283         if (!IS_ERR(dst)) {
 284                 /* Walk through the bind address list and look for a bind
 285                  * address that matches the source address of the returned dst.
 286                  */
 287                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 288                 rcu_read_lock();
 289                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 290                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 291                             (laddr->state != SCTP_ADDR_SRC &&
 292                              !asoc->src_out_of_asoc_ok))
 293                                 continue;
 294
 295                         /* Do not compare against v4 addrs */
 296                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 297                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 298                                 rcu_read_unlock();
 299                                 goto out;
 300                         }
 301                 }
 302                 rcu_read_unlock();
 303                 /* None of the bound addresses match the source address of the
 304                  * dst. So release it.
 305                  */
 306                 dst_release(dst);
 307                 dst = NULL;
 308         }
 309
 310         /* Walk through the bind address list and try to get the
 311          * best source address for a given destination.
 312          */
 313         rcu_read_lock();
 314         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 315                 struct dst_entry *bdst;
 316                 __u8 bmatchlen;
 317
 318                 if (!laddr->valid ||
 319                     laddr->state != SCTP_ADDR_SRC ||
 320                     laddr->a.sa.sa_family != AF_INET6 ||
 321                     scope > sctp_scope(&laddr->a))
 322                         continue;
 323
 324                 fl6->saddr = laddr->a.v6.sin6_addr;
 325                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 326                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 327                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 328
 329                 if (!IS_ERR(bdst) &&
 330                     ipv6_chk_addr(dev_net(bdst->dev),
 331                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 332                         if (!IS_ERR_OR_NULL(dst))
 333                                 dst_release(dst);
 334                         dst = bdst;
 335                         break;
 336                 }
 337
 338                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 339                 if (matchlen > bmatchlen)
 340                         continue;
 341
 342                 if (!IS_ERR_OR_NULL(dst))
 343                         dst_release(dst);
 344                 dst = bdst;
 345                 matchlen = bmatchlen;
 346         }
 347         rcu_read_unlock();
 348
 349 out:
 350         if (!IS_ERR_OR_NULL(dst)) {
 351                 struct rt6_info *rt;
 352
 353                 rt = (struct rt6_info *)dst;
 354                 t->dst = dst;
 355                 t->dst_cookie = rt6_get_cookie(rt);
 356                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 357                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 358                          &fl6->saddr);
 359         } else {
 360                 t->dst = NULL;
 361
 362                 pr_debug("no route\n");
 363         }
 364 }
 365
 366 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 367  * addresses.
 368  */
 369 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 370                                          union sctp_addr *s2)
 371 {
 372         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 373 }
 374
 375 /* Fills in the source address(saddr) based on the destination address(daddr)
 376  * and asoc's bind address list.
 377  */
 378 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 379                               struct sctp_transport *t,
 380                               struct flowi *fl)
 381 {
 382         struct flowi6 *fl6 = &fl->u.ip6;
 383         union sctp_addr *saddr = &t->saddr;
 384
 385         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 386
 387         if (t->dst) {
 388                 saddr->v6.sin6_family = AF_INET6;
 389                 saddr->v6.sin6_addr = fl6->saddr;
 390         }
 391 }
 392
 393 /* Make a copy of all potential local addresses. */
 394 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 395                                   struct net_device *dev)
 396 {
 397         struct inet6_dev *in6_dev;
 398         struct inet6_ifaddr *ifp;
 399         struct sctp_sockaddr_entry *addr;
 400
 401         rcu_read_lock();
 402         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 403                 rcu_read_unlock();
 404                 return;
 405         }
 406
 407         read_lock_bh(&in6_dev->lock);
 408         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 409                 /* Add the address to the local list.  */
 410                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 411                 if (addr) {
 412                         addr->a.v6.sin6_family = AF_INET6;
 413                         addr->a.v6.sin6_port = 0;
 414                         addr->a.v6.sin6_addr = ifp->addr;
 415                         addr->a.v6.sin6_scope_id = dev->ifindex;
 416                         addr->valid = 1;
 417                         INIT_LIST_HEAD(&addr->list);
 418                         list_add_tail(&addr->list, addrlist);
 419                 }
 420         }
 421
 422         read_unlock_bh(&in6_dev->lock);
 423         rcu_read_unlock();
 424 }
 425
 426 /* Initialize a sockaddr_storage from in incoming skb. */
 427 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 428                              int is_saddr)
 429 {
 430         /* Always called on head skb, so this is safe */
 431         struct sctphdr *sh = sctp_hdr(skb);
 432         struct sockaddr_in6 *sa = &addr->v6;
 433
 434         addr->v6.sin6_family = AF_INET6;
 435         addr->v6.sin6_flowinfo = 0; /* FIXME */
 436         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 437
 438         if (is_saddr) {
 439                 sa->sin6_port = sh->source;
 440                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 441         } else {
 442                 sa->sin6_port = sh->dest;
 443                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 444         }
 445 }
 446
 447 /* Initialize an sctp_addr from a socket. */
 448 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 449 {
 450         addr->v6.sin6_family = AF_INET6;
 451         addr->v6.sin6_port = 0;
 452         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 453 }
 454
 455 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 456 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 457 {
 458         if (addr->sa.sa_family == AF_INET) {
 459                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 460                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 461                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 462                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 463                         addr->v4.sin_addr.s_addr;
 464         } else {
 465                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 466         }
 467 }
 468
 469 /* Initialize sk->sk_daddr from sctp_addr. */
 470 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 471 {
 472         if (addr->sa.sa_family == AF_INET) {
 473                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 474                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 475                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 476                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 477         } else {
 478                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 479         }
 480 }
 481
 482 /* Initialize a sctp_addr from an address parameter. */
 483 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 484                                     union sctp_addr_param *param,
 485                                     __be16 port, int iif)
 486 {
 487         addr->v6.sin6_family = AF_INET6;
 488         addr->v6.sin6_port = port;
 489         addr->v6.sin6_flowinfo = 0; /* BUG */
 490         addr->v6.sin6_addr = param->v6.addr;
 491         addr->v6.sin6_scope_id = iif;
 492 }
 493
 494 /* Initialize an address parameter from a sctp_addr and return the length
 495  * of the address parameter.
 496  */
 497 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 498                                  union sctp_addr_param *param)
 499 {
 500         int length = sizeof(struct sctp_ipv6addr_param);
 501
 502         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 503         param->v6.param_hdr.length = htons(length);
 504         param->v6.addr = addr->v6.sin6_addr;
 505
 506         return length;
 507 }
 508
 509 /* Initialize a sctp_addr from struct in6_addr. */
 510 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 511                               __be16 port)
 512 {
 513         addr->sa.sa_family = AF_INET6;
 514         addr->v6.sin6_port = port;
 515         addr->v6.sin6_flowinfo = 0;
 516         addr->v6.sin6_addr = *saddr;
 517         addr->v6.sin6_scope_id = 0;
 518 }
 519
 520 /* Compare addresses exactly.
 521  * v4-mapped-v6 is also in consideration.
 522  */
 523 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 524                             const union sctp_addr *addr2)
 525 {
 526         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 527                 if (addr1->sa.sa_family == AF_INET &&
 528                     addr2->sa.sa_family == AF_INET6 &&
 529                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 530                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 531                             addr2->v6.sin6_addr.s6_addr32[3] ==
 532                             addr1->v4.sin_addr.s_addr)
 533                                 return 1;
 534                 }
 535                 if (addr2->sa.sa_family == AF_INET &&
 536                     addr1->sa.sa_family == AF_INET6 &&
 537                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 538                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 539                             addr1->v6.sin6_addr.s6_addr32[3] ==
 540                             addr2->v4.sin_addr.s_addr)
 541                                 return 1;
 542                 }
 543                 return 0;
 544         }
 545         if (addr1->v6.sin6_port != addr2->v6.sin6_port)
 546                 return 0;
 547         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 548                 return 0;
 549         /* If this is a linklocal address, compare the scope_id. */
 550         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 551                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 552                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 553                         return 0;
 554                 }
 555         }
 556
 557         return 1;
 558 }
 559
 560 /* Initialize addr struct to INADDR_ANY. */
 561 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 562 {
 563         memset(addr, 0x00, sizeof(union sctp_addr));
 564         addr->v6.sin6_family = AF_INET6;
 565         addr->v6.sin6_port = port;
 566 }
 567
 568 /* Is this a wildcard address? */
 569 static int sctp_v6_is_any(const union sctp_addr *addr)
 570 {
 571         return ipv6_addr_any(&addr->v6.sin6_addr);
 572 }
 573
 574 /* Should this be available for binding?   */
 575 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 576 {
 577         int type;
 578         struct net *net = sock_net(&sp->inet.sk);
 579         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 580
 581         type = ipv6_addr_type(in6);
 582         if (IPV6_ADDR_ANY == type)
 583                 return 1;
 584         if (type == IPV6_ADDR_MAPPED) {
 585                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 586                         return 0;
 587                 sctp_v6_map_v4(addr);
 588                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 589         }
 590         if (!(type & IPV6_ADDR_UNICAST))
 591                 return 0;
 592
 593         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 594                 ipv6_chk_addr(net, in6, NULL, 0);
 595 }
 596
 597 /* This function checks if the address is a valid address to be used for
 598  * SCTP.
 599  *
 600  * Output:
 601  * Return 0 - If the address is a non-unicast or an illegal address.
 602  * Return 1 - If the address is a unicast.
 603  */
 604 static int sctp_v6_addr_valid(union sctp_addr *addr,
 605                               struct sctp_sock *sp,
 606                               const struct sk_buff *skb)
 607 {
 608         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 609
 610         /* Support v4-mapped-v6 address. */
 611         if (ret == IPV6_ADDR_MAPPED) {
 612                 /* Note: This routine is used in input, so v4-mapped-v6
 613                  * are disallowed here when there is no sctp_sock.
 614                  */
 615                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 616                         return 0;
 617                 sctp_v6_map_v4(addr);
 618                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 619         }
 620
 621         /* Is this a non-unicast address */
 622         if (!(ret & IPV6_ADDR_UNICAST))
 623                 return 0;
 624
 625         return 1;
 626 }
 627
 628 /* What is the scope of 'addr'?  */
 629 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 630 {
 631         enum sctp_scope retval;
 632         int v6scope;
 633
 634         /* The IPv6 scope is really a set of bit fields.
 635          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 636          */
 637
 638         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 639         switch (v6scope) {
 640         case IFA_HOST:
 641                 retval = SCTP_SCOPE_LOOPBACK;
 642                 break;
 643         case IFA_LINK:
 644                 retval = SCTP_SCOPE_LINK;
 645                 break;
 646         case IFA_SITE:
 647                 retval = SCTP_SCOPE_PRIVATE;
 648                 break;
 649         default:
 650                 retval = SCTP_SCOPE_GLOBAL;
 651                 break;
 652         }
 653
 654         return retval;
 655 }
 656
 657 /* Create and initialize a new sk for the socket to be returned by accept(). */
 658 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 659                                              struct sctp_association *asoc,
 660                                              bool kern)
 661 {
 662         struct sock *newsk;
 663         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 664         struct sctp6_sock *newsctp6sk;
 665         struct ipv6_txoptions *opt;
 666
 667         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 668         if (!newsk)
 669                 goto out;
 670
 671         sock_init_data(NULL, newsk);
 672
 673         sctp_copy_sock(newsk, sk, asoc);
 674         sock_reset_flag(sk, SOCK_ZAPPED);
 675
 676         newsctp6sk = (struct sctp6_sock *)newsk;
 677         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 678
 679         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 680
 681         newnp = inet6_sk(newsk);
 682
 683         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 684         newnp->ipv6_mc_list = NULL;
 685         newnp->ipv6_ac_list = NULL;
 686         newnp->ipv6_fl_list = NULL;
 687
 688         rcu_read_lock();
 689         opt = rcu_dereference(np->opt);
 690         if (opt)
 691                 opt = ipv6_dup_options(newsk, opt);
 692         RCU_INIT_POINTER(newnp->opt, opt);
 693         rcu_read_unlock();
 694
 695         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 696          * and getpeername().
 697          */
 698         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 699
 700         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 701
 702         sk_refcnt_debug_inc(newsk);
 703
 704         if (newsk->sk_prot->init(newsk)) {
 705                 sk_common_release(newsk);
 706                 newsk = NULL;
 707         }
 708
 709 out:
 710         return newsk;
 711 }
 712
 713 /* Format a sockaddr for return to user space. This makes sure the return is
 714  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 715  */
 716 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 717 {
 718         if (sp->v4mapped) {
 719                 if (addr->sa.sa_family == AF_INET)
 720                         sctp_v4_map_v6(addr);
 721         } else {
 722                 if (addr->sa.sa_family == AF_INET6 &&
 723                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 724                         sctp_v6_map_v4(addr);
 725         }
 726
 727         if (addr->sa.sa_family == AF_INET)
 728                 return sizeof(struct sockaddr_in);
 729         return sizeof(struct sockaddr_in6);
 730 }
 731
 732 /* Where did this skb come from?  */
 733 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 734 {
 735         return IP6CB(skb)->iif;
 736 }
 737
 738 /* Was this packet marked by Explicit Congestion Notification? */
 739 static int sctp_v6_is_ce(const struct sk_buff *skb)
 740 {
 741         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 742 }
 743
 744 /* Dump the v6 addr to the seq file. */
 745 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 746 {
 747         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 748 }
 749
 750 static void sctp_v6_ecn_capable(struct sock *sk)
 751 {
 752         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 753 }
 754
 755 /* Initialize a PF_INET msgname from a ulpevent. */
 756 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 757                                      char *msgname, int *addrlen)
 758 {
 759         union sctp_addr *addr;
 760         struct sctp_association *asoc;
 761         union sctp_addr *paddr;
 762
 763         if (!msgname)
 764                 return;
 765
 766         addr = (union sctp_addr *)msgname;
 767         asoc = event->asoc;
 768         paddr = &asoc->peer.primary_addr;
 769
 770         if (paddr->sa.sa_family == AF_INET) {
 771                 addr->v4.sin_family = AF_INET;
 772                 addr->v4.sin_port = htons(asoc->peer.port);
 773                 addr->v4.sin_addr = paddr->v4.sin_addr;
 774         } else {
 775                 addr->v6.sin6_family = AF_INET6;
 776                 addr->v6.sin6_flowinfo = 0;
 777                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 778                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 779                 else
 780                         addr->v6.sin6_scope_id = 0;
 781                 addr->v6.sin6_port = htons(asoc->peer.port);
 782                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 783         }
 784
 785         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 786 }
 787
 788 /* Initialize a msg_name from an inbound skb. */
 789 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 790                                    int *addr_len)
 791 {
 792         union sctp_addr *addr;
 793         struct sctphdr *sh;
 794
 795         if (!msgname)
 796                 return;
 797
 798         addr = (union sctp_addr *)msgname;
 799         sh = sctp_hdr(skb);
 800
 801         if (ip_hdr(skb)->version == 4) {
 802                 addr->v4.sin_family = AF_INET;
 803                 addr->v4.sin_port = sh->source;
 804                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 805         } else {
 806                 addr->v6.sin6_family = AF_INET6;
 807                 addr->v6.sin6_flowinfo = 0;
 808                 addr->v6.sin6_port = sh->source;
 809                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 810                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 811                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 812                 else
 813                         addr->v6.sin6_scope_id = 0;
 814         }
 815
 816         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 817 }
 818
 819 /* Do we support this AF? */
 820 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 821 {
 822         switch (family) {
 823         case AF_INET6:
 824                 return 1;
 825         /* v4-mapped-v6 addresses */
 826         case AF_INET:
 827                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 828                         return 1;
 829                 /* fallthru */
 830         default:
 831                 return 0;
 832         }
 833 }
 834
 835 /* Address matching with wildcards allowed.  This extra level
 836  * of indirection lets us choose whether a PF_INET6 should
 837  * disallow any v4 addresses if we so choose.
 838  */
 839 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 840                                const union sctp_addr *addr2,
 841                                struct sctp_sock *opt)
 842 {
 843         struct sctp_af *af1, *af2;
 844         struct sock *sk = sctp_opt2sk(opt);
 845
 846         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 847         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 848
 849         if (!af1 || !af2)
 850                 return 0;
 851
 852         /* If the socket is IPv6 only, v4 addrs will not match */
 853         if (__ipv6_only_sock(sk) && af1 != af2)
 854                 return 0;
 855
 856         /* Today, wildcard AF_INET/AF_INET6. */
 857         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 858                 return 1;
 859
 860         if (addr1->sa.sa_family != addr2->sa.sa_family)
 861                 return 0;
 862
 863         return af1->cmp_addr(addr1, addr2);
 864 }
 865
 866 /* Verify that the provided sockaddr looks bindable.   Common verification,
 867  * has already been taken care of.
 868  */
 869 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 870 {
 871         struct sctp_af *af;
 872
 873         /* ASSERT: address family has already been verified. */
 874         if (addr->sa.sa_family != AF_INET6)
 875                 af = sctp_get_af_specific(addr->sa.sa_family);
 876         else {
 877                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 878                 struct net_device *dev;
 879
 880                 if (type & IPV6_ADDR_LINKLOCAL) {
 881                         struct net *net;
 882                         if (!addr->v6.sin6_scope_id)
 883                                 return 0;
 884                         net = sock_net(&opt->inet.sk);
 885                         rcu_read_lock();
 886                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 887                         if (!dev || !(opt->inet.freebind ||
 888                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 889                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 890                                                     dev, 0))) {
 891                                 rcu_read_unlock();
 892                                 return 0;
 893                         }
 894                         rcu_read_unlock();
 895                 }
 896
 897                 af = opt->pf->af;
 898         }
 899         return af->available(addr, opt);
 900 }
 901
 902 /* Verify that the provided sockaddr looks sendable.   Common verification,
 903  * has already been taken care of.
 904  */
 905 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 906 {
 907         struct sctp_af *af = NULL;
 908
 909         /* ASSERT: address family has already been verified. */
 910         if (addr->sa.sa_family != AF_INET6)
 911                 af = sctp_get_af_specific(addr->sa.sa_family);
 912         else {
 913                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 914                 struct net_device *dev;
 915
 916                 if (type & IPV6_ADDR_LINKLOCAL) {
 917                         if (!addr->v6.sin6_scope_id)
 918                                 return 0;
 919                         rcu_read_lock();
 920                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 921                                                    addr->v6.sin6_scope_id);
 922                         rcu_read_unlock();
 923                         if (!dev)
 924                                 return 0;
 925                 }
 926                 af = opt->pf->af;
 927         }
 928
 929         return af != NULL;
 930 }
 931
 932 /* Fill in Supported Address Type information for INIT and INIT-ACK
 933  * chunks.   Note: In the future, we may want to look at sock options
 934  * to determine whether a PF_INET6 socket really wants to have IPV4
 935  * addresses.
 936  * Returns number of addresses supported.
 937  */
 938 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 939                                       __be16 *types)
 940 {
 941         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 942         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 943                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 944                 return 2;
 945         }
 946         return 1;
 947 }
 948
 949 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 950 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 951                         int *uaddr_len, int peer)
 952 {
 953         int rc;
 954
 955         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
 956
 957         if (rc != 0)
 958                 return rc;
 959
 960         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
 961                                           (union sctp_addr *)uaddr);
 962
 963         return rc;
 964 }
 965
 966 static const struct proto_ops inet6_seqpacket_ops = {
 967         .family            = PF_INET6,
 968         .owner             = THIS_MODULE,
 969         .release           = inet6_release,
 970         .bind              = inet6_bind,
 971         .connect           = inet_dgram_connect,
 972         .socketpair        = sock_no_socketpair,
 973         .accept            = inet_accept,
 974         .getname           = sctp_getname,
 975         .poll              = sctp_poll,
 976         .ioctl             = inet6_ioctl,
 977         .listen            = sctp_inet_listen,
 978         .shutdown          = inet_shutdown,
 979         .setsockopt        = sock_common_setsockopt,
 980         .getsockopt        = sock_common_getsockopt,
 981         .sendmsg           = inet_sendmsg,
 982         .recvmsg           = inet_recvmsg,
 983         .mmap              = sock_no_mmap,
 984 #ifdef CONFIG_COMPAT
 985         .compat_setsockopt = compat_sock_common_setsockopt,
 986         .compat_getsockopt = compat_sock_common_getsockopt,
 987 #endif
 988 };
 989
 990 static struct inet_protosw sctpv6_seqpacket_protosw = {
 991         .type          = SOCK_SEQPACKET,
 992         .protocol      = IPPROTO_SCTP,
 993         .prot          = &sctpv6_prot,
 994         .ops           = &inet6_seqpacket_ops,
 995         .flags         = SCTP_PROTOSW_FLAG
 996 };
 997 static struct inet_protosw sctpv6_stream_protosw = {
 998         .type          = SOCK_STREAM,
 999         .protocol      = IPPROTO_SCTP,
1000         .prot          = &sctpv6_prot,
1001         .ops           = &inet6_seqpacket_ops,
1002         .flags         = SCTP_PROTOSW_FLAG,
1003 };
1004
1005 static int sctp6_rcv(struct sk_buff *skb)
1006 {
1007         return sctp_rcv(skb) ? -1 : 0;
1008 }
1009
1010 static const struct inet6_protocol sctpv6_protocol = {
1011         .handler      = sctp6_rcv,
1012         .err_handler  = sctp_v6_err,
1013         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1014 };
1015
1016 static struct sctp_af sctp_af_inet6 = {
1017         .sa_family         = AF_INET6,
1018         .sctp_xmit         = sctp_v6_xmit,
1019         .setsockopt        = ipv6_setsockopt,
1020         .getsockopt        = ipv6_getsockopt,
1021         .get_dst           = sctp_v6_get_dst,
1022         .get_saddr         = sctp_v6_get_saddr,
1023         .copy_addrlist     = sctp_v6_copy_addrlist,
1024         .from_skb          = sctp_v6_from_skb,
1025         .from_sk           = sctp_v6_from_sk,
1026         .from_addr_param   = sctp_v6_from_addr_param,
1027         .to_addr_param     = sctp_v6_to_addr_param,
1028         .cmp_addr          = sctp_v6_cmp_addr,
1029         .scope             = sctp_v6_scope,
1030         .addr_valid        = sctp_v6_addr_valid,
1031         .inaddr_any        = sctp_v6_inaddr_any,
1032         .is_any            = sctp_v6_is_any,
1033         .available         = sctp_v6_available,
1034         .skb_iif           = sctp_v6_skb_iif,
1035         .is_ce             = sctp_v6_is_ce,
1036         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1037         .ecn_capable       = sctp_v6_ecn_capable,
1038         .net_header_len    = sizeof(struct ipv6hdr),
1039         .sockaddr_len      = sizeof(struct sockaddr_in6),
1040 #ifdef CONFIG_COMPAT
1041         .compat_setsockopt = compat_ipv6_setsockopt,
1042         .compat_getsockopt = compat_ipv6_getsockopt,
1043 #endif
1044 };
1045
1046 static struct sctp_pf sctp_pf_inet6 = {
1047         .event_msgname = sctp_inet6_event_msgname,
1048         .skb_msgname   = sctp_inet6_skb_msgname,
1049         .af_supported  = sctp_inet6_af_supported,
1050         .cmp_addr      = sctp_inet6_cmp_addr,
1051         .bind_verify   = sctp_inet6_bind_verify,
1052         .send_verify   = sctp_inet6_send_verify,
1053         .supported_addrs = sctp_inet6_supported_addrs,
1054         .create_accept_sk = sctp_v6_create_accept_sk,
1055         .addr_to_user  = sctp_v6_addr_to_user,
1056         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1057         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1058         .af            = &sctp_af_inet6,
1059 };
1060
1061 /* Initialize IPv6 support and register with socket layer.  */
1062 void sctp_v6_pf_init(void)
1063 {
1064         /* Register the SCTP specific PF_INET6 functions. */
1065         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1066
1067         /* Register the SCTP specific AF_INET6 functions. */
1068         sctp_register_af(&sctp_af_inet6);
1069 }
1070
1071 void sctp_v6_pf_exit(void)
1072 {
1073         list_del(&sctp_af_inet6.list);
1074 }
1075
1076 /* Initialize IPv6 support and register with socket layer.  */
1077 int sctp_v6_protosw_init(void)
1078 {
1079         int rc;
1080
1081         rc = proto_register(&sctpv6_prot, 1);
1082         if (rc)
1083                 return rc;
1084
1085         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1086         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1087         inet6_register_protosw(&sctpv6_stream_protosw);
1088
1089         return 0;
1090 }
1091
1092 void sctp_v6_protosw_exit(void)
1093 {
1094         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1095         inet6_unregister_protosw(&sctpv6_stream_protosw);
1096         proto_unregister(&sctpv6_prot);
1097 }
1098
1099
1100 /* Register with inet6 layer. */
1101 int sctp_v6_add_protocol(void)
1102 {
1103         /* Register notifier for inet6 address additions/deletions. */
1104         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1105
1106         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1107                 return -EAGAIN;
1108
1109         return 0;
1110 }
1111
1112 /* Unregister with inet6 layer. */
1113 void sctp_v6_del_protocol(void)
1114 {
1115         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1116         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1117 }