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 = kzalloc(sizeof(*addr), GFP_ATOMIC);
 101                 if (addr) {
 102                         addr->a.v6.sin6_family = AF_INET6;
 103                         addr->a.v6.sin6_addr = ifa->addr;
 104                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 105                         addr->valid = 1;
 106                         spin_lock_bh(&net->sctp.local_addr_lock);
 107                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 108                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 109                         spin_unlock_bh(&net->sctp.local_addr_lock);
 110                 }
 111                 break;
 112         case NETDEV_DOWN:
 113                 spin_lock_bh(&net->sctp.local_addr_lock);
 114                 list_for_each_entry_safe(addr, temp,
 115                                         &net->sctp.local_addr_list, list) {
 116                         if (addr->a.sa.sa_family == AF_INET6 &&
 117                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 118                                                 &ifa->addr)) {
 119                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 120                                 found = 1;
 121                                 addr->valid = 0;
 122                                 list_del_rcu(&addr->list);
 123                                 break;
 124                         }
 125                 }
 126                 spin_unlock_bh(&net->sctp.local_addr_lock);
 127                 if (found)
 128                         kfree_rcu(addr, rcu);
 129                 break;
 130         }
 131
 132         return NOTIFY_DONE;
 133 }
 134
 135 static struct notifier_block sctp_inet6addr_notifier = {
 136         .notifier_call = sctp_inet6addr_event,
 137 };
 138
 139 /* ICMP error handler. */
 140 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 141                         u8 type, u8 code, int offset, __be32 info)
 142 {
 143         struct inet6_dev *idev;
 144         struct sock *sk;
 145         struct sctp_association *asoc;
 146         struct sctp_transport *transport;
 147         struct ipv6_pinfo *np;
 148         __u16 saveip, savesctp;
 149         int err, ret = 0;
 150         struct net *net = dev_net(skb->dev);
 151
 152         idev = in6_dev_get(skb->dev);
 153
 154         /* Fix up skb to look at the embedded net header. */
 155         saveip   = skb->network_header;
 156         savesctp = skb->transport_header;
 157         skb_reset_network_header(skb);
 158         skb_set_transport_header(skb, offset);
 159         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 160         /* Put back, the original pointers. */
 161         skb->network_header   = saveip;
 162         skb->transport_header = savesctp;
 163         if (!sk) {
 164                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
 165                 ret = -ENOENT;
 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         return ret;
 207 }
 208
 209 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 210 {
 211         struct sock *sk = skb->sk;
 212         struct ipv6_pinfo *np = inet6_sk(sk);
 213         struct flowi6 *fl6 = &transport->fl.u.ip6;
 214         __u8 tclass = np->tclass;
 215         int res;
 216
 217         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 218                  skb->len, &fl6->saddr, &fl6->daddr);
 219
 220         if (transport->dscp & SCTP_DSCP_SET_MASK)
 221                 tclass = transport->dscp & SCTP_DSCP_VAL_MASK;
 222
 223         if (INET_ECN_is_capable(tclass))
 224                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 225
 226         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 227                 skb->ignore_df = 1;
 228
 229         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 230
 231         rcu_read_lock();
 232         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
 233                        tclass);
 234         rcu_read_unlock();
 235         return res;
 236 }
 237
 238 /* Returns the dst cache entry for the given source and destination ip
 239  * addresses.
 240  */
 241 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 242                             struct flowi *fl, struct sock *sk)
 243 {
 244         struct sctp_association *asoc = t->asoc;
 245         struct dst_entry *dst = NULL;
 246         struct flowi6 *fl6 = &fl->u.ip6;
 247         struct sctp_bind_addr *bp;
 248         struct ipv6_pinfo *np = inet6_sk(sk);
 249         struct sctp_sockaddr_entry *laddr;
 250         union sctp_addr *daddr = &t->ipaddr;
 251         union sctp_addr dst_saddr;
 252         struct in6_addr *final_p, final;
 253         enum sctp_scope scope;
 254         __u8 matchlen = 0;
 255
 256         memset(fl6, 0, sizeof(struct flowi6));
 257         fl6->daddr = daddr->v6.sin6_addr;
 258         fl6->fl6_dport = daddr->v6.sin6_port;
 259         fl6->flowi6_proto = IPPROTO_SCTP;
 260         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 261                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 262         else if (asoc)
 263                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 264         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
 265                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 266
 267         if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
 268                 struct ip6_flowlabel *flowlabel;
 269
 270                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
 271                 if (!flowlabel)
 272                         goto out;
 273                 fl6_sock_release(flowlabel);
 274         }
 275
 276         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 277
 278         if (asoc)
 279                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 280
 281         if (saddr) {
 282                 fl6->saddr = saddr->v6.sin6_addr;
 283                 if (!fl6->fl6_sport)
 284                         fl6->fl6_sport = saddr->v6.sin6_port;
 285
 286                 pr_debug("src=%pI6 - ", &fl6->saddr);
 287         }
 288
 289         rcu_read_lock();
 290         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 291         rcu_read_unlock();
 292
 293         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 294         if (!asoc || saddr)
 295                 goto out;
 296
 297         bp = &asoc->base.bind_addr;
 298         scope = sctp_scope(daddr);
 299         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 300          * to see if we can use it.
 301          */
 302         if (!IS_ERR(dst)) {
 303                 /* Walk through the bind address list and look for a bind
 304                  * address that matches the source address of the returned dst.
 305                  */
 306                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 307                 rcu_read_lock();
 308                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 309                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 310                             (laddr->state != SCTP_ADDR_SRC &&
 311                              !asoc->src_out_of_asoc_ok))
 312                                 continue;
 313
 314                         /* Do not compare against v4 addrs */
 315                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 316                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 317                                 rcu_read_unlock();
 318                                 goto out;
 319                         }
 320                 }
 321                 rcu_read_unlock();
 322                 /* None of the bound addresses match the source address of the
 323                  * dst. So release it.
 324                  */
 325                 dst_release(dst);
 326                 dst = NULL;
 327         }
 328
 329         /* Walk through the bind address list and try to get the
 330          * best source address for a given destination.
 331          */
 332         rcu_read_lock();
 333         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 334                 struct dst_entry *bdst;
 335                 __u8 bmatchlen;
 336
 337                 if (!laddr->valid ||
 338                     laddr->state != SCTP_ADDR_SRC ||
 339                     laddr->a.sa.sa_family != AF_INET6 ||
 340                     scope > sctp_scope(&laddr->a))
 341                         continue;
 342
 343                 fl6->saddr = laddr->a.v6.sin6_addr;
 344                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 345                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 346                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 347
 348                 if (IS_ERR(bdst))
 349                         continue;
 350
 351                 if (ipv6_chk_addr(dev_net(bdst->dev),
 352                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 353                         if (!IS_ERR_OR_NULL(dst))
 354                                 dst_release(dst);
 355                         dst = bdst;
 356                         break;
 357                 }
 358
 359                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 360                 if (matchlen > bmatchlen) {
 361                         dst_release(bdst);
 362                         continue;
 363                 }
 364
 365                 if (!IS_ERR_OR_NULL(dst))
 366                         dst_release(dst);
 367                 dst = bdst;
 368                 matchlen = bmatchlen;
 369         }
 370         rcu_read_unlock();
 371
 372 out:
 373         if (!IS_ERR_OR_NULL(dst)) {
 374                 struct rt6_info *rt;
 375
 376                 rt = (struct rt6_info *)dst;
 377                 t->dst = dst;
 378                 t->dst_cookie = rt6_get_cookie(rt);
 379                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 380                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 381                          &fl6->saddr);
 382         } else {
 383                 t->dst = NULL;
 384
 385                 pr_debug("no route\n");
 386         }
 387 }
 388
 389 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 390  * addresses.
 391  */
 392 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 393                                          union sctp_addr *s2)
 394 {
 395         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 396 }
 397
 398 /* Fills in the source address(saddr) based on the destination address(daddr)
 399  * and asoc's bind address list.
 400  */
 401 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 402                               struct sctp_transport *t,
 403                               struct flowi *fl)
 404 {
 405         struct flowi6 *fl6 = &fl->u.ip6;
 406         union sctp_addr *saddr = &t->saddr;
 407
 408         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 409
 410         if (t->dst) {
 411                 saddr->v6.sin6_family = AF_INET6;
 412                 saddr->v6.sin6_addr = fl6->saddr;
 413         }
 414 }
 415
 416 /* Make a copy of all potential local addresses. */
 417 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 418                                   struct net_device *dev)
 419 {
 420         struct inet6_dev *in6_dev;
 421         struct inet6_ifaddr *ifp;
 422         struct sctp_sockaddr_entry *addr;
 423
 424         rcu_read_lock();
 425         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 426                 rcu_read_unlock();
 427                 return;
 428         }
 429
 430         read_lock_bh(&in6_dev->lock);
 431         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 432                 /* Add the address to the local list.  */
 433                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 434                 if (addr) {
 435                         addr->a.v6.sin6_family = AF_INET6;
 436                         addr->a.v6.sin6_addr = ifp->addr;
 437                         addr->a.v6.sin6_scope_id = dev->ifindex;
 438                         addr->valid = 1;
 439                         INIT_LIST_HEAD(&addr->list);
 440                         list_add_tail(&addr->list, addrlist);
 441                 }
 442         }
 443
 444         read_unlock_bh(&in6_dev->lock);
 445         rcu_read_unlock();
 446 }
 447
 448 /* Copy over any ip options */
 449 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
 450 {
 451         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 452         struct ipv6_txoptions *opt;
 453
 454         newnp = inet6_sk(newsk);
 455
 456         rcu_read_lock();
 457         opt = rcu_dereference(np->opt);
 458         if (opt) {
 459                 opt = ipv6_dup_options(newsk, opt);
 460                 if (!opt)
 461                         pr_err("%s: Failed to copy ip options\n", __func__);
 462         }
 463         RCU_INIT_POINTER(newnp->opt, opt);
 464         rcu_read_unlock();
 465 }
 466
 467 /* Account for the IP options */
 468 static int sctp_v6_ip_options_len(struct sock *sk)
 469 {
 470         struct ipv6_pinfo *np = inet6_sk(sk);
 471         struct ipv6_txoptions *opt;
 472         int len = 0;
 473
 474         rcu_read_lock();
 475         opt = rcu_dereference(np->opt);
 476         if (opt)
 477                 len = opt->opt_flen + opt->opt_nflen;
 478
 479         rcu_read_unlock();
 480         return len;
 481 }
 482
 483 /* Initialize a sockaddr_storage from in incoming skb. */
 484 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 485                              int is_saddr)
 486 {
 487         /* Always called on head skb, so this is safe */
 488         struct sctphdr *sh = sctp_hdr(skb);
 489         struct sockaddr_in6 *sa = &addr->v6;
 490
 491         addr->v6.sin6_family = AF_INET6;
 492         addr->v6.sin6_flowinfo = 0; /* FIXME */
 493         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 494
 495         if (is_saddr) {
 496                 sa->sin6_port = sh->source;
 497                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 498         } else {
 499                 sa->sin6_port = sh->dest;
 500                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 501         }
 502 }
 503
 504 /* Initialize an sctp_addr from a socket. */
 505 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 506 {
 507         addr->v6.sin6_family = AF_INET6;
 508         addr->v6.sin6_port = 0;
 509         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 510 }
 511
 512 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 513 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 514 {
 515         if (addr->sa.sa_family == AF_INET) {
 516                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 517                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 518                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 519                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 520                         addr->v4.sin_addr.s_addr;
 521         } else {
 522                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 523         }
 524 }
 525
 526 /* Initialize sk->sk_daddr from sctp_addr. */
 527 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 528 {
 529         if (addr->sa.sa_family == AF_INET) {
 530                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 531                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 532                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 533                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 534         } else {
 535                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 536         }
 537 }
 538
 539 /* Initialize a sctp_addr from an address parameter. */
 540 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 541                                     union sctp_addr_param *param,
 542                                     __be16 port, int iif)
 543 {
 544         addr->v6.sin6_family = AF_INET6;
 545         addr->v6.sin6_port = port;
 546         addr->v6.sin6_flowinfo = 0; /* BUG */
 547         addr->v6.sin6_addr = param->v6.addr;
 548         addr->v6.sin6_scope_id = iif;
 549 }
 550
 551 /* Initialize an address parameter from a sctp_addr and return the length
 552  * of the address parameter.
 553  */
 554 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 555                                  union sctp_addr_param *param)
 556 {
 557         int length = sizeof(struct sctp_ipv6addr_param);
 558
 559         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 560         param->v6.param_hdr.length = htons(length);
 561         param->v6.addr = addr->v6.sin6_addr;
 562
 563         return length;
 564 }
 565
 566 /* Initialize a sctp_addr from struct in6_addr. */
 567 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 568                               __be16 port)
 569 {
 570         addr->sa.sa_family = AF_INET6;
 571         addr->v6.sin6_port = port;
 572         addr->v6.sin6_flowinfo = 0;
 573         addr->v6.sin6_addr = *saddr;
 574         addr->v6.sin6_scope_id = 0;
 575 }
 576
 577 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 578                               const union sctp_addr *addr2)
 579 {
 580         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 581                 if (addr1->sa.sa_family == AF_INET &&
 582                     addr2->sa.sa_family == AF_INET6 &&
 583                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 584                     addr2->v6.sin6_addr.s6_addr32[3] ==
 585                     addr1->v4.sin_addr.s_addr)
 586                         return 1;
 587
 588                 if (addr2->sa.sa_family == AF_INET &&
 589                     addr1->sa.sa_family == AF_INET6 &&
 590                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 591                     addr1->v6.sin6_addr.s6_addr32[3] ==
 592                     addr2->v4.sin_addr.s_addr)
 593                         return 1;
 594
 595                 return 0;
 596         }
 597
 598         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 599                 return 0;
 600
 601         /* If this is a linklocal address, compare the scope_id. */
 602         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 603             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 604             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 605                 return 0;
 606
 607         return 1;
 608 }
 609
 610 /* Compare addresses exactly.
 611  * v4-mapped-v6 is also in consideration.
 612  */
 613 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 614                             const union sctp_addr *addr2)
 615 {
 616         return __sctp_v6_cmp_addr(addr1, addr2) &&
 617                addr1->v6.sin6_port == addr2->v6.sin6_port;
 618 }
 619
 620 /* Initialize addr struct to INADDR_ANY. */
 621 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 622 {
 623         memset(addr, 0x00, sizeof(union sctp_addr));
 624         addr->v6.sin6_family = AF_INET6;
 625         addr->v6.sin6_port = port;
 626 }
 627
 628 /* Is this a wildcard address? */
 629 static int sctp_v6_is_any(const union sctp_addr *addr)
 630 {
 631         return ipv6_addr_any(&addr->v6.sin6_addr);
 632 }
 633
 634 /* Should this be available for binding?   */
 635 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 636 {
 637         int type;
 638         struct net *net = sock_net(&sp->inet.sk);
 639         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 640
 641         type = ipv6_addr_type(in6);
 642         if (IPV6_ADDR_ANY == type)
 643                 return 1;
 644         if (type == IPV6_ADDR_MAPPED) {
 645                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 646                         return 0;
 647                 sctp_v6_map_v4(addr);
 648                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 649         }
 650         if (!(type & IPV6_ADDR_UNICAST))
 651                 return 0;
 652
 653         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 654                 ipv6_chk_addr(net, in6, NULL, 0);
 655 }
 656
 657 /* This function checks if the address is a valid address to be used for
 658  * SCTP.
 659  *
 660  * Output:
 661  * Return 0 - If the address is a non-unicast or an illegal address.
 662  * Return 1 - If the address is a unicast.
 663  */
 664 static int sctp_v6_addr_valid(union sctp_addr *addr,
 665                               struct sctp_sock *sp,
 666                               const struct sk_buff *skb)
 667 {
 668         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 669
 670         /* Support v4-mapped-v6 address. */
 671         if (ret == IPV6_ADDR_MAPPED) {
 672                 /* Note: This routine is used in input, so v4-mapped-v6
 673                  * are disallowed here when there is no sctp_sock.
 674                  */
 675                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 676                         return 0;
 677                 sctp_v6_map_v4(addr);
 678                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 679         }
 680
 681         /* Is this a non-unicast address */
 682         if (!(ret & IPV6_ADDR_UNICAST))
 683                 return 0;
 684
 685         return 1;
 686 }
 687
 688 /* What is the scope of 'addr'?  */
 689 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 690 {
 691         enum sctp_scope retval;
 692         int v6scope;
 693
 694         /* The IPv6 scope is really a set of bit fields.
 695          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 696          */
 697
 698         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 699         switch (v6scope) {
 700         case IFA_HOST:
 701                 retval = SCTP_SCOPE_LOOPBACK;
 702                 break;
 703         case IFA_LINK:
 704                 retval = SCTP_SCOPE_LINK;
 705                 break;
 706         case IFA_SITE:
 707                 retval = SCTP_SCOPE_PRIVATE;
 708                 break;
 709         default:
 710                 retval = SCTP_SCOPE_GLOBAL;
 711                 break;
 712         }
 713
 714         return retval;
 715 }
 716
 717 /* Create and initialize a new sk for the socket to be returned by accept(). */
 718 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 719                                              struct sctp_association *asoc,
 720                                              bool kern)
 721 {
 722         struct sock *newsk;
 723         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 724         struct sctp6_sock *newsctp6sk;
 725
 726         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 727         if (!newsk)
 728                 goto out;
 729
 730         sock_init_data(NULL, newsk);
 731
 732         sctp_copy_sock(newsk, sk, asoc);
 733         sock_reset_flag(sk, SOCK_ZAPPED);
 734
 735         newsctp6sk = (struct sctp6_sock *)newsk;
 736         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 737
 738         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 739
 740         newnp = inet6_sk(newsk);
 741
 742         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 743         newnp->ipv6_mc_list = NULL;
 744         newnp->ipv6_ac_list = NULL;
 745         newnp->ipv6_fl_list = NULL;
 746
 747         sctp_v6_copy_ip_options(sk, newsk);
 748
 749         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 750          * and getpeername().
 751          */
 752         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 753
 754         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 755
 756         sk_refcnt_debug_inc(newsk);
 757
 758         if (newsk->sk_prot->init(newsk)) {
 759                 sk_common_release(newsk);
 760                 newsk = NULL;
 761         }
 762
 763 out:
 764         return newsk;
 765 }
 766
 767 /* Format a sockaddr for return to user space. This makes sure the return is
 768  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 769  */
 770 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 771 {
 772         if (sp->v4mapped) {
 773                 if (addr->sa.sa_family == AF_INET)
 774                         sctp_v4_map_v6(addr);
 775         } else {
 776                 if (addr->sa.sa_family == AF_INET6 &&
 777                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 778                         sctp_v6_map_v4(addr);
 779         }
 780
 781         if (addr->sa.sa_family == AF_INET) {
 782                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 783                 return sizeof(struct sockaddr_in);
 784         }
 785         return sizeof(struct sockaddr_in6);
 786 }
 787
 788 /* Where did this skb come from?  */
 789 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 790 {
 791         return IP6CB(skb)->iif;
 792 }
 793
 794 /* Was this packet marked by Explicit Congestion Notification? */
 795 static int sctp_v6_is_ce(const struct sk_buff *skb)
 796 {
 797         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 798 }
 799
 800 /* Dump the v6 addr to the seq file. */
 801 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 802 {
 803         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 804 }
 805
 806 static void sctp_v6_ecn_capable(struct sock *sk)
 807 {
 808         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 809 }
 810
 811 /* Initialize a PF_INET msgname from a ulpevent. */
 812 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 813                                      char *msgname, int *addrlen)
 814 {
 815         union sctp_addr *addr;
 816         struct sctp_association *asoc;
 817         union sctp_addr *paddr;
 818
 819         if (!msgname)
 820                 return;
 821
 822         addr = (union sctp_addr *)msgname;
 823         asoc = event->asoc;
 824         paddr = &asoc->peer.primary_addr;
 825
 826         if (paddr->sa.sa_family == AF_INET) {
 827                 addr->v4.sin_family = AF_INET;
 828                 addr->v4.sin_port = htons(asoc->peer.port);
 829                 addr->v4.sin_addr = paddr->v4.sin_addr;
 830         } else {
 831                 addr->v6.sin6_family = AF_INET6;
 832                 addr->v6.sin6_flowinfo = 0;
 833                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 834                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 835                 else
 836                         addr->v6.sin6_scope_id = 0;
 837                 addr->v6.sin6_port = htons(asoc->peer.port);
 838                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 839         }
 840
 841         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 842 }
 843
 844 /* Initialize a msg_name from an inbound skb. */
 845 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 846                                    int *addr_len)
 847 {
 848         union sctp_addr *addr;
 849         struct sctphdr *sh;
 850
 851         if (!msgname)
 852                 return;
 853
 854         addr = (union sctp_addr *)msgname;
 855         sh = sctp_hdr(skb);
 856
 857         if (ip_hdr(skb)->version == 4) {
 858                 addr->v4.sin_family = AF_INET;
 859                 addr->v4.sin_port = sh->source;
 860                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 861         } else {
 862                 addr->v6.sin6_family = AF_INET6;
 863                 addr->v6.sin6_flowinfo = 0;
 864                 addr->v6.sin6_port = sh->source;
 865                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 866                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 867                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 868                 else
 869                         addr->v6.sin6_scope_id = 0;
 870         }
 871
 872         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 873 }
 874
 875 /* Do we support this AF? */
 876 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 877 {
 878         switch (family) {
 879         case AF_INET6:
 880                 return 1;
 881         /* v4-mapped-v6 addresses */
 882         case AF_INET:
 883                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 884                         return 1;
 885                 /* fallthru */
 886         default:
 887                 return 0;
 888         }
 889 }
 890
 891 /* Address matching with wildcards allowed.  This extra level
 892  * of indirection lets us choose whether a PF_INET6 should
 893  * disallow any v4 addresses if we so choose.
 894  */
 895 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 896                                const union sctp_addr *addr2,
 897                                struct sctp_sock *opt)
 898 {
 899         struct sock *sk = sctp_opt2sk(opt);
 900         struct sctp_af *af1, *af2;
 901
 902         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 903         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 904
 905         if (!af1 || !af2)
 906                 return 0;
 907
 908         /* If the socket is IPv6 only, v4 addrs will not match */
 909         if (__ipv6_only_sock(sk) && af1 != af2)
 910                 return 0;
 911
 912         /* Today, wildcard AF_INET/AF_INET6. */
 913         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 914                 return 1;
 915
 916         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 917                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 918
 919         return __sctp_v6_cmp_addr(addr1, addr2);
 920 }
 921
 922 /* Verify that the provided sockaddr looks bindable.   Common verification,
 923  * has already been taken care of.
 924  */
 925 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 926 {
 927         struct sctp_af *af;
 928
 929         /* ASSERT: address family has already been verified. */
 930         if (addr->sa.sa_family != AF_INET6)
 931                 af = sctp_get_af_specific(addr->sa.sa_family);
 932         else {
 933                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 934                 struct net_device *dev;
 935
 936                 if (type & IPV6_ADDR_LINKLOCAL) {
 937                         struct net *net;
 938                         if (!addr->v6.sin6_scope_id)
 939                                 return 0;
 940                         net = sock_net(&opt->inet.sk);
 941                         rcu_read_lock();
 942                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 943                         if (!dev || !(opt->inet.freebind ||
 944                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 945                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 946                                                     dev, 0))) {
 947                                 rcu_read_unlock();
 948                                 return 0;
 949                         }
 950                         rcu_read_unlock();
 951                 }
 952
 953                 af = opt->pf->af;
 954         }
 955         return af->available(addr, opt);
 956 }
 957
 958 /* Verify that the provided sockaddr looks sendable.   Common verification,
 959  * has already been taken care of.
 960  */
 961 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 962 {
 963         struct sctp_af *af = NULL;
 964
 965         /* ASSERT: address family has already been verified. */
 966         if (addr->sa.sa_family != AF_INET6)
 967                 af = sctp_get_af_specific(addr->sa.sa_family);
 968         else {
 969                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 970                 struct net_device *dev;
 971
 972                 if (type & IPV6_ADDR_LINKLOCAL) {
 973                         if (!addr->v6.sin6_scope_id)
 974                                 return 0;
 975                         rcu_read_lock();
 976                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 977                                                    addr->v6.sin6_scope_id);
 978                         rcu_read_unlock();
 979                         if (!dev)
 980                                 return 0;
 981                 }
 982                 af = opt->pf->af;
 983         }
 984
 985         return af != NULL;
 986 }
 987
 988 /* Fill in Supported Address Type information for INIT and INIT-ACK
 989  * chunks.   Note: In the future, we may want to look at sock options
 990  * to determine whether a PF_INET6 socket really wants to have IPV4
 991  * addresses.
 992  * Returns number of addresses supported.
 993  */
 994 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 995                                       __be16 *types)
 996 {
 997         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 998         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 999                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
1000                 return 2;
1001         }
1002         return 1;
1003 }
1004
1005 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1006 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1007                         int peer)
1008 {
1009         int rc;
1010
1011         rc = inet6_getname(sock, uaddr, peer);
1012
1013         if (rc < 0)
1014                 return rc;
1015
1016         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1017                                           (union sctp_addr *)uaddr);
1018
1019         return rc;
1020 }
1021
1022 static const struct proto_ops inet6_seqpacket_ops = {
1023         .family            = PF_INET6,
1024         .owner             = THIS_MODULE,
1025         .release           = inet6_release,
1026         .bind              = inet6_bind,
1027         .connect           = sctp_inet_connect,
1028         .socketpair        = sock_no_socketpair,
1029         .accept            = inet_accept,
1030         .getname           = sctp_getname,
1031         .poll              = sctp_poll,
1032         .ioctl             = inet6_ioctl,
1033         .gettstamp         = sock_gettstamp,
1034         .listen            = sctp_inet_listen,
1035         .shutdown          = inet_shutdown,
1036         .setsockopt        = sock_common_setsockopt,
1037         .getsockopt        = sock_common_getsockopt,
1038         .sendmsg           = inet_sendmsg,
1039         .recvmsg           = inet_recvmsg,
1040         .mmap              = sock_no_mmap,
1041 #ifdef CONFIG_COMPAT
1042         .compat_setsockopt = compat_sock_common_setsockopt,
1043         .compat_getsockopt = compat_sock_common_getsockopt,
1044 #endif
1045 };
1046
1047 static struct inet_protosw sctpv6_seqpacket_protosw = {
1048         .type          = SOCK_SEQPACKET,
1049         .protocol      = IPPROTO_SCTP,
1050         .prot          = &sctpv6_prot,
1051         .ops           = &inet6_seqpacket_ops,
1052         .flags         = SCTP_PROTOSW_FLAG
1053 };
1054 static struct inet_protosw sctpv6_stream_protosw = {
1055         .type          = SOCK_STREAM,
1056         .protocol      = IPPROTO_SCTP,
1057         .prot          = &sctpv6_prot,
1058         .ops           = &inet6_seqpacket_ops,
1059         .flags         = SCTP_PROTOSW_FLAG,
1060 };
1061
1062 static int sctp6_rcv(struct sk_buff *skb)
1063 {
1064         return sctp_rcv(skb) ? -1 : 0;
1065 }
1066
1067 static const struct inet6_protocol sctpv6_protocol = {
1068         .handler      = sctp6_rcv,
1069         .err_handler  = sctp_v6_err,
1070         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1071 };
1072
1073 static struct sctp_af sctp_af_inet6 = {
1074         .sa_family         = AF_INET6,
1075         .sctp_xmit         = sctp_v6_xmit,
1076         .setsockopt        = ipv6_setsockopt,
1077         .getsockopt        = ipv6_getsockopt,
1078         .get_dst           = sctp_v6_get_dst,
1079         .get_saddr         = sctp_v6_get_saddr,
1080         .copy_addrlist     = sctp_v6_copy_addrlist,
1081         .from_skb          = sctp_v6_from_skb,
1082         .from_sk           = sctp_v6_from_sk,
1083         .from_addr_param   = sctp_v6_from_addr_param,
1084         .to_addr_param     = sctp_v6_to_addr_param,
1085         .cmp_addr          = sctp_v6_cmp_addr,
1086         .scope             = sctp_v6_scope,
1087         .addr_valid        = sctp_v6_addr_valid,
1088         .inaddr_any        = sctp_v6_inaddr_any,
1089         .is_any            = sctp_v6_is_any,
1090         .available         = sctp_v6_available,
1091         .skb_iif           = sctp_v6_skb_iif,
1092         .is_ce             = sctp_v6_is_ce,
1093         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1094         .ecn_capable       = sctp_v6_ecn_capable,
1095         .net_header_len    = sizeof(struct ipv6hdr),
1096         .sockaddr_len      = sizeof(struct sockaddr_in6),
1097         .ip_options_len    = sctp_v6_ip_options_len,
1098 #ifdef CONFIG_COMPAT
1099         .compat_setsockopt = compat_ipv6_setsockopt,
1100         .compat_getsockopt = compat_ipv6_getsockopt,
1101 #endif
1102 };
1103
1104 static struct sctp_pf sctp_pf_inet6 = {
1105         .event_msgname = sctp_inet6_event_msgname,
1106         .skb_msgname   = sctp_inet6_skb_msgname,
1107         .af_supported  = sctp_inet6_af_supported,
1108         .cmp_addr      = sctp_inet6_cmp_addr,
1109         .bind_verify   = sctp_inet6_bind_verify,
1110         .send_verify   = sctp_inet6_send_verify,
1111         .supported_addrs = sctp_inet6_supported_addrs,
1112         .create_accept_sk = sctp_v6_create_accept_sk,
1113         .addr_to_user  = sctp_v6_addr_to_user,
1114         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1115         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1116         .copy_ip_options = sctp_v6_copy_ip_options,
1117         .af            = &sctp_af_inet6,
1118 };
1119
1120 /* Initialize IPv6 support and register with socket layer.  */
1121 void sctp_v6_pf_init(void)
1122 {
1123         /* Register the SCTP specific PF_INET6 functions. */
1124         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1125
1126         /* Register the SCTP specific AF_INET6 functions. */
1127         sctp_register_af(&sctp_af_inet6);
1128 }
1129
1130 void sctp_v6_pf_exit(void)
1131 {
1132         list_del(&sctp_af_inet6.list);
1133 }
1134
1135 /* Initialize IPv6 support and register with socket layer.  */
1136 int sctp_v6_protosw_init(void)
1137 {
1138         int rc;
1139
1140         rc = proto_register(&sctpv6_prot, 1);
1141         if (rc)
1142                 return rc;
1143
1144         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1145         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1146         inet6_register_protosw(&sctpv6_stream_protosw);
1147
1148         return 0;
1149 }
1150
1151 void sctp_v6_protosw_exit(void)
1152 {
1153         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1154         inet6_unregister_protosw(&sctpv6_stream_protosw);
1155         proto_unregister(&sctpv6_prot);
1156 }
1157
1158
1159 /* Register with inet6 layer. */
1160 int sctp_v6_add_protocol(void)
1161 {
1162         /* Register notifier for inet6 address additions/deletions. */
1163         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1164
1165         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1166                 return -EAGAIN;
1167
1168         return 0;
1169 }
1170
1171 /* Unregister with inet6 layer. */
1172 void sctp_v6_del_protocol(void)
1173 {
1174         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1175         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1176 }