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_flowinfo = 0;
 105                         addr->a.v6.sin6_addr = ifa->addr;
 106                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 107                         addr->valid = 1;
 108                         spin_lock_bh(&net->sctp.local_addr_lock);
 109                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 110                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 111                         spin_unlock_bh(&net->sctp.local_addr_lock);
 112                 }
 113                 break;
 114         case NETDEV_DOWN:
 115                 spin_lock_bh(&net->sctp.local_addr_lock);
 116                 list_for_each_entry_safe(addr, temp,
 117                                         &net->sctp.local_addr_list, list) {
 118                         if (addr->a.sa.sa_family == AF_INET6 &&
 119                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 120                                                 &ifa->addr)) {
 121                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 122                                 found = 1;
 123                                 addr->valid = 0;
 124                                 list_del_rcu(&addr->list);
 125                                 break;
 126                         }
 127                 }
 128                 spin_unlock_bh(&net->sctp.local_addr_lock);
 129                 if (found)
 130                         kfree_rcu(addr, rcu);
 131                 break;
 132         }
 133
 134         return NOTIFY_DONE;
 135 }
 136
 137 static struct notifier_block sctp_inet6addr_notifier = {
 138         .notifier_call = sctp_inet6addr_event,
 139 };
 140
 141 /* ICMP error handler. */
 142 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 143                         u8 type, u8 code, int offset, __be32 info)
 144 {
 145         struct inet6_dev *idev;
 146         struct sock *sk;
 147         struct sctp_association *asoc;
 148         struct sctp_transport *transport;
 149         struct ipv6_pinfo *np;
 150         __u16 saveip, savesctp;
 151         int err, ret = 0;
 152         struct net *net = dev_net(skb->dev);
 153
 154         idev = in6_dev_get(skb->dev);
 155
 156         /* Fix up skb to look at the embedded net header. */
 157         saveip   = skb->network_header;
 158         savesctp = skb->transport_header;
 159         skb_reset_network_header(skb);
 160         skb_set_transport_header(skb, offset);
 161         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 162         /* Put back, the original pointers. */
 163         skb->network_header   = saveip;
 164         skb->transport_header = savesctp;
 165         if (!sk) {
 166                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
 167                 ret = -ENOENT;
 168                 goto out;
 169         }
 170
 171         /* Warning:  The sock lock is held.  Remember to call
 172          * sctp_err_finish!
 173          */
 174
 175         switch (type) {
 176         case ICMPV6_PKT_TOOBIG:
 177                 if (ip6_sk_accept_pmtu(sk))
 178                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 179                 goto out_unlock;
 180         case ICMPV6_PARAMPROB:
 181                 if (ICMPV6_UNK_NEXTHDR == code) {
 182                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 183                         goto out_unlock;
 184                 }
 185                 break;
 186         case NDISC_REDIRECT:
 187                 sctp_icmp_redirect(sk, transport, skb);
 188                 goto out_unlock;
 189         default:
 190                 break;
 191         }
 192
 193         np = inet6_sk(sk);
 194         icmpv6_err_convert(type, code, &err);
 195         if (!sock_owned_by_user(sk) && np->recverr) {
 196                 sk->sk_err = err;
 197                 sk->sk_error_report(sk);
 198         } else {  /* Only an error on timeout */
 199                 sk->sk_err_soft = err;
 200         }
 201
 202 out_unlock:
 203         sctp_err_finish(sk, transport);
 204 out:
 205         if (likely(idev != NULL))
 206                 in6_dev_put(idev);
 207
 208         return ret;
 209 }
 210
 211 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 212 {
 213         struct sock *sk = skb->sk;
 214         struct ipv6_pinfo *np = inet6_sk(sk);
 215         struct flowi6 *fl6 = &transport->fl.u.ip6;
 216         __u8 tclass = np->tclass;
 217         int res;
 218
 219         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 220                  skb->len, &fl6->saddr, &fl6->daddr);
 221
 222         if (transport->dscp & SCTP_DSCP_SET_MASK)
 223                 tclass = transport->dscp & SCTP_DSCP_VAL_MASK;
 224
 225         if (INET_ECN_is_capable(tclass))
 226                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 227
 228         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 229                 skb->ignore_df = 1;
 230
 231         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 232
 233         rcu_read_lock();
 234         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
 235                        tclass);
 236         rcu_read_unlock();
 237         return res;
 238 }
 239
 240 /* Returns the dst cache entry for the given source and destination ip
 241  * addresses.
 242  */
 243 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 244                             struct flowi *fl, struct sock *sk)
 245 {
 246         struct sctp_association *asoc = t->asoc;
 247         struct dst_entry *dst = NULL;
 248         struct flowi6 *fl6 = &fl->u.ip6;
 249         struct sctp_bind_addr *bp;
 250         struct ipv6_pinfo *np = inet6_sk(sk);
 251         struct sctp_sockaddr_entry *laddr;
 252         union sctp_addr *daddr = &t->ipaddr;
 253         union sctp_addr dst_saddr;
 254         struct in6_addr *final_p, final;
 255         enum sctp_scope scope;
 256         __u8 matchlen = 0;
 257
 258         memset(fl6, 0, sizeof(struct flowi6));
 259         fl6->daddr = daddr->v6.sin6_addr;
 260         fl6->fl6_dport = daddr->v6.sin6_port;
 261         fl6->flowi6_proto = IPPROTO_SCTP;
 262         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 263                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 264         else if (asoc)
 265                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 266         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
 267                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 268
 269         if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
 270                 struct ip6_flowlabel *flowlabel;
 271
 272                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
 273                 if (!flowlabel)
 274                         goto out;
 275                 fl6_sock_release(flowlabel);
 276         }
 277
 278         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 279
 280         if (asoc)
 281                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 282
 283         if (saddr) {
 284                 fl6->saddr = saddr->v6.sin6_addr;
 285                 fl6->fl6_sport = saddr->v6.sin6_port;
 286
 287                 pr_debug("src=%pI6 - ", &fl6->saddr);
 288         }
 289
 290         rcu_read_lock();
 291         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 292         rcu_read_unlock();
 293
 294         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 295         if (!asoc || saddr)
 296                 goto out;
 297
 298         bp = &asoc->base.bind_addr;
 299         scope = sctp_scope(daddr);
 300         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 301          * to see if we can use it.
 302          */
 303         if (!IS_ERR(dst)) {
 304                 /* Walk through the bind address list and look for a bind
 305                  * address that matches the source address of the returned dst.
 306                  */
 307                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 308                 rcu_read_lock();
 309                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 310                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 311                             (laddr->state != SCTP_ADDR_SRC &&
 312                              !asoc->src_out_of_asoc_ok))
 313                                 continue;
 314
 315                         /* Do not compare against v4 addrs */
 316                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 317                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 318                                 rcu_read_unlock();
 319                                 goto out;
 320                         }
 321                 }
 322                 rcu_read_unlock();
 323                 /* None of the bound addresses match the source address of the
 324                  * dst. So release it.
 325                  */
 326                 dst_release(dst);
 327                 dst = NULL;
 328         }
 329
 330         /* Walk through the bind address list and try to get the
 331          * best source address for a given destination.
 332          */
 333         rcu_read_lock();
 334         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 335                 struct dst_entry *bdst;
 336                 __u8 bmatchlen;
 337
 338                 if (!laddr->valid ||
 339                     laddr->state != SCTP_ADDR_SRC ||
 340                     laddr->a.sa.sa_family != AF_INET6 ||
 341                     scope > sctp_scope(&laddr->a))
 342                         continue;
 343
 344                 fl6->saddr = laddr->a.v6.sin6_addr;
 345                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 346                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 347                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 348
 349                 if (IS_ERR(bdst))
 350                         continue;
 351
 352                 if (ipv6_chk_addr(dev_net(bdst->dev),
 353                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 354                         if (!IS_ERR_OR_NULL(dst))
 355                                 dst_release(dst);
 356                         dst = bdst;
 357                         break;
 358                 }
 359
 360                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 361                 if (matchlen > bmatchlen) {
 362                         dst_release(bdst);
 363                         continue;
 364                 }
 365
 366                 if (!IS_ERR_OR_NULL(dst))
 367                         dst_release(dst);
 368                 dst = bdst;
 369                 matchlen = bmatchlen;
 370         }
 371         rcu_read_unlock();
 372
 373 out:
 374         if (!IS_ERR_OR_NULL(dst)) {
 375                 struct rt6_info *rt;
 376
 377                 rt = (struct rt6_info *)dst;
 378                 t->dst = dst;
 379                 t->dst_cookie = rt6_get_cookie(rt);
 380                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 381                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 382                          &fl6->saddr);
 383         } else {
 384                 t->dst = NULL;
 385
 386                 pr_debug("no route\n");
 387         }
 388 }
 389
 390 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 391  * addresses.
 392  */
 393 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 394                                          union sctp_addr *s2)
 395 {
 396         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 397 }
 398
 399 /* Fills in the source address(saddr) based on the destination address(daddr)
 400  * and asoc's bind address list.
 401  */
 402 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 403                               struct sctp_transport *t,
 404                               struct flowi *fl)
 405 {
 406         struct flowi6 *fl6 = &fl->u.ip6;
 407         union sctp_addr *saddr = &t->saddr;
 408
 409         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 410
 411         if (t->dst) {
 412                 saddr->v6.sin6_family = AF_INET6;
 413                 saddr->v6.sin6_addr = fl6->saddr;
 414         }
 415 }
 416
 417 /* Make a copy of all potential local addresses. */
 418 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 419                                   struct net_device *dev)
 420 {
 421         struct inet6_dev *in6_dev;
 422         struct inet6_ifaddr *ifp;
 423         struct sctp_sockaddr_entry *addr;
 424
 425         rcu_read_lock();
 426         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 427                 rcu_read_unlock();
 428                 return;
 429         }
 430
 431         read_lock_bh(&in6_dev->lock);
 432         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 433                 /* Add the address to the local list.  */
 434                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 435                 if (addr) {
 436                         addr->a.v6.sin6_family = AF_INET6;
 437                         addr->a.v6.sin6_port = 0;
 438                         addr->a.v6.sin6_addr = ifp->addr;
 439                         addr->a.v6.sin6_scope_id = dev->ifindex;
 440                         addr->valid = 1;
 441                         INIT_LIST_HEAD(&addr->list);
 442                         list_add_tail(&addr->list, addrlist);
 443                 }
 444         }
 445
 446         read_unlock_bh(&in6_dev->lock);
 447         rcu_read_unlock();
 448 }
 449
 450 /* Copy over any ip options */
 451 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
 452 {
 453         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 454         struct ipv6_txoptions *opt;
 455
 456         newnp = inet6_sk(newsk);
 457
 458         rcu_read_lock();
 459         opt = rcu_dereference(np->opt);
 460         if (opt) {
 461                 opt = ipv6_dup_options(newsk, opt);
 462                 if (!opt)
 463                         pr_err("%s: Failed to copy ip options\n", __func__);
 464         }
 465         RCU_INIT_POINTER(newnp->opt, opt);
 466         rcu_read_unlock();
 467 }
 468
 469 /* Account for the IP options */
 470 static int sctp_v6_ip_options_len(struct sock *sk)
 471 {
 472         struct ipv6_pinfo *np = inet6_sk(sk);
 473         struct ipv6_txoptions *opt;
 474         int len = 0;
 475
 476         rcu_read_lock();
 477         opt = rcu_dereference(np->opt);
 478         if (opt)
 479                 len = opt->opt_flen + opt->opt_nflen;
 480
 481         rcu_read_unlock();
 482         return len;
 483 }
 484
 485 /* Initialize a sockaddr_storage from in incoming skb. */
 486 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 487                              int is_saddr)
 488 {
 489         /* Always called on head skb, so this is safe */
 490         struct sctphdr *sh = sctp_hdr(skb);
 491         struct sockaddr_in6 *sa = &addr->v6;
 492
 493         addr->v6.sin6_family = AF_INET6;
 494         addr->v6.sin6_flowinfo = 0; /* FIXME */
 495         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 496
 497         if (is_saddr) {
 498                 sa->sin6_port = sh->source;
 499                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 500         } else {
 501                 sa->sin6_port = sh->dest;
 502                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 503         }
 504 }
 505
 506 /* Initialize an sctp_addr from a socket. */
 507 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 508 {
 509         addr->v6.sin6_family = AF_INET6;
 510         addr->v6.sin6_port = 0;
 511         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 512 }
 513
 514 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 515 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 516 {
 517         if (addr->sa.sa_family == AF_INET) {
 518                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 519                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 520                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 521                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 522                         addr->v4.sin_addr.s_addr;
 523         } else {
 524                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 525         }
 526 }
 527
 528 /* Initialize sk->sk_daddr from sctp_addr. */
 529 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 530 {
 531         if (addr->sa.sa_family == AF_INET) {
 532                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 533                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 534                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 535                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 536         } else {
 537                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 538         }
 539 }
 540
 541 /* Initialize a sctp_addr from an address parameter. */
 542 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 543                                     union sctp_addr_param *param,
 544                                     __be16 port, int iif)
 545 {
 546         addr->v6.sin6_family = AF_INET6;
 547         addr->v6.sin6_port = port;
 548         addr->v6.sin6_flowinfo = 0; /* BUG */
 549         addr->v6.sin6_addr = param->v6.addr;
 550         addr->v6.sin6_scope_id = iif;
 551 }
 552
 553 /* Initialize an address parameter from a sctp_addr and return the length
 554  * of the address parameter.
 555  */
 556 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 557                                  union sctp_addr_param *param)
 558 {
 559         int length = sizeof(struct sctp_ipv6addr_param);
 560
 561         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 562         param->v6.param_hdr.length = htons(length);
 563         param->v6.addr = addr->v6.sin6_addr;
 564
 565         return length;
 566 }
 567
 568 /* Initialize a sctp_addr from struct in6_addr. */
 569 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 570                               __be16 port)
 571 {
 572         addr->sa.sa_family = AF_INET6;
 573         addr->v6.sin6_port = port;
 574         addr->v6.sin6_flowinfo = 0;
 575         addr->v6.sin6_addr = *saddr;
 576         addr->v6.sin6_scope_id = 0;
 577 }
 578
 579 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 580                               const union sctp_addr *addr2)
 581 {
 582         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 583                 if (addr1->sa.sa_family == AF_INET &&
 584                     addr2->sa.sa_family == AF_INET6 &&
 585                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 586                     addr2->v6.sin6_addr.s6_addr32[3] ==
 587                     addr1->v4.sin_addr.s_addr)
 588                         return 1;
 589
 590                 if (addr2->sa.sa_family == AF_INET &&
 591                     addr1->sa.sa_family == AF_INET6 &&
 592                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 593                     addr1->v6.sin6_addr.s6_addr32[3] ==
 594                     addr2->v4.sin_addr.s_addr)
 595                         return 1;
 596
 597                 return 0;
 598         }
 599
 600         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 601                 return 0;
 602
 603         /* If this is a linklocal address, compare the scope_id. */
 604         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 605             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 606             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 607                 return 0;
 608
 609         return 1;
 610 }
 611
 612 /* Compare addresses exactly.
 613  * v4-mapped-v6 is also in consideration.
 614  */
 615 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 616                             const union sctp_addr *addr2)
 617 {
 618         return __sctp_v6_cmp_addr(addr1, addr2) &&
 619                addr1->v6.sin6_port == addr2->v6.sin6_port;
 620 }
 621
 622 /* Initialize addr struct to INADDR_ANY. */
 623 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 624 {
 625         memset(addr, 0x00, sizeof(union sctp_addr));
 626         addr->v6.sin6_family = AF_INET6;
 627         addr->v6.sin6_port = port;
 628 }
 629
 630 /* Is this a wildcard address? */
 631 static int sctp_v6_is_any(const union sctp_addr *addr)
 632 {
 633         return ipv6_addr_any(&addr->v6.sin6_addr);
 634 }
 635
 636 /* Should this be available for binding?   */
 637 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 638 {
 639         int type;
 640         struct net *net = sock_net(&sp->inet.sk);
 641         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 642
 643         type = ipv6_addr_type(in6);
 644         if (IPV6_ADDR_ANY == type)
 645                 return 1;
 646         if (type == IPV6_ADDR_MAPPED) {
 647                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 648                         return 0;
 649                 sctp_v6_map_v4(addr);
 650                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 651         }
 652         if (!(type & IPV6_ADDR_UNICAST))
 653                 return 0;
 654
 655         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 656                 ipv6_chk_addr(net, in6, NULL, 0);
 657 }
 658
 659 /* This function checks if the address is a valid address to be used for
 660  * SCTP.
 661  *
 662  * Output:
 663  * Return 0 - If the address is a non-unicast or an illegal address.
 664  * Return 1 - If the address is a unicast.
 665  */
 666 static int sctp_v6_addr_valid(union sctp_addr *addr,
 667                               struct sctp_sock *sp,
 668                               const struct sk_buff *skb)
 669 {
 670         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 671
 672         /* Support v4-mapped-v6 address. */
 673         if (ret == IPV6_ADDR_MAPPED) {
 674                 /* Note: This routine is used in input, so v4-mapped-v6
 675                  * are disallowed here when there is no sctp_sock.
 676                  */
 677                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 678                         return 0;
 679                 sctp_v6_map_v4(addr);
 680                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 681         }
 682
 683         /* Is this a non-unicast address */
 684         if (!(ret & IPV6_ADDR_UNICAST))
 685                 return 0;
 686
 687         return 1;
 688 }
 689
 690 /* What is the scope of 'addr'?  */
 691 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 692 {
 693         enum sctp_scope retval;
 694         int v6scope;
 695
 696         /* The IPv6 scope is really a set of bit fields.
 697          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 698          */
 699
 700         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 701         switch (v6scope) {
 702         case IFA_HOST:
 703                 retval = SCTP_SCOPE_LOOPBACK;
 704                 break;
 705         case IFA_LINK:
 706                 retval = SCTP_SCOPE_LINK;
 707                 break;
 708         case IFA_SITE:
 709                 retval = SCTP_SCOPE_PRIVATE;
 710                 break;
 711         default:
 712                 retval = SCTP_SCOPE_GLOBAL;
 713                 break;
 714         }
 715
 716         return retval;
 717 }
 718
 719 /* Create and initialize a new sk for the socket to be returned by accept(). */
 720 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 721                                              struct sctp_association *asoc,
 722                                              bool kern)
 723 {
 724         struct sock *newsk;
 725         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 726         struct sctp6_sock *newsctp6sk;
 727
 728         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 729         if (!newsk)
 730                 goto out;
 731
 732         sock_init_data(NULL, newsk);
 733
 734         sctp_copy_sock(newsk, sk, asoc);
 735         sock_reset_flag(sk, SOCK_ZAPPED);
 736
 737         newsctp6sk = (struct sctp6_sock *)newsk;
 738         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 739
 740         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 741
 742         newnp = inet6_sk(newsk);
 743
 744         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 745         newnp->ipv6_mc_list = NULL;
 746         newnp->ipv6_ac_list = NULL;
 747         newnp->ipv6_fl_list = NULL;
 748
 749         sctp_v6_copy_ip_options(sk, newsk);
 750
 751         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 752          * and getpeername().
 753          */
 754         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 755
 756         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 757
 758         sk_refcnt_debug_inc(newsk);
 759
 760         if (newsk->sk_prot->init(newsk)) {
 761                 sk_common_release(newsk);
 762                 newsk = NULL;
 763         }
 764
 765 out:
 766         return newsk;
 767 }
 768
 769 /* Format a sockaddr for return to user space. This makes sure the return is
 770  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 771  */
 772 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 773 {
 774         if (sp->v4mapped) {
 775                 if (addr->sa.sa_family == AF_INET)
 776                         sctp_v4_map_v6(addr);
 777         } else {
 778                 if (addr->sa.sa_family == AF_INET6 &&
 779                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 780                         sctp_v6_map_v4(addr);
 781         }
 782
 783         if (addr->sa.sa_family == AF_INET) {
 784                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 785                 return sizeof(struct sockaddr_in);
 786         }
 787         return sizeof(struct sockaddr_in6);
 788 }
 789
 790 /* Where did this skb come from?  */
 791 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 792 {
 793         return IP6CB(skb)->iif;
 794 }
 795
 796 /* Was this packet marked by Explicit Congestion Notification? */
 797 static int sctp_v6_is_ce(const struct sk_buff *skb)
 798 {
 799         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 800 }
 801
 802 /* Dump the v6 addr to the seq file. */
 803 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 804 {
 805         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 806 }
 807
 808 static void sctp_v6_ecn_capable(struct sock *sk)
 809 {
 810         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 811 }
 812
 813 /* Initialize a PF_INET msgname from a ulpevent. */
 814 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 815                                      char *msgname, int *addrlen)
 816 {
 817         union sctp_addr *addr;
 818         struct sctp_association *asoc;
 819         union sctp_addr *paddr;
 820
 821         if (!msgname)
 822                 return;
 823
 824         addr = (union sctp_addr *)msgname;
 825         asoc = event->asoc;
 826         paddr = &asoc->peer.primary_addr;
 827
 828         if (paddr->sa.sa_family == AF_INET) {
 829                 addr->v4.sin_family = AF_INET;
 830                 addr->v4.sin_port = htons(asoc->peer.port);
 831                 addr->v4.sin_addr = paddr->v4.sin_addr;
 832         } else {
 833                 addr->v6.sin6_family = AF_INET6;
 834                 addr->v6.sin6_flowinfo = 0;
 835                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 836                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 837                 else
 838                         addr->v6.sin6_scope_id = 0;
 839                 addr->v6.sin6_port = htons(asoc->peer.port);
 840                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 841         }
 842
 843         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 844 }
 845
 846 /* Initialize a msg_name from an inbound skb. */
 847 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 848                                    int *addr_len)
 849 {
 850         union sctp_addr *addr;
 851         struct sctphdr *sh;
 852
 853         if (!msgname)
 854                 return;
 855
 856         addr = (union sctp_addr *)msgname;
 857         sh = sctp_hdr(skb);
 858
 859         if (ip_hdr(skb)->version == 4) {
 860                 addr->v4.sin_family = AF_INET;
 861                 addr->v4.sin_port = sh->source;
 862                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 863         } else {
 864                 addr->v6.sin6_family = AF_INET6;
 865                 addr->v6.sin6_flowinfo = 0;
 866                 addr->v6.sin6_port = sh->source;
 867                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 868                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 869                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 870                 else
 871                         addr->v6.sin6_scope_id = 0;
 872         }
 873
 874         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 875 }
 876
 877 /* Do we support this AF? */
 878 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 879 {
 880         switch (family) {
 881         case AF_INET6:
 882                 return 1;
 883         /* v4-mapped-v6 addresses */
 884         case AF_INET:
 885                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 886                         return 1;
 887                 /* fallthru */
 888         default:
 889                 return 0;
 890         }
 891 }
 892
 893 /* Address matching with wildcards allowed.  This extra level
 894  * of indirection lets us choose whether a PF_INET6 should
 895  * disallow any v4 addresses if we so choose.
 896  */
 897 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 898                                const union sctp_addr *addr2,
 899                                struct sctp_sock *opt)
 900 {
 901         struct sock *sk = sctp_opt2sk(opt);
 902         struct sctp_af *af1, *af2;
 903
 904         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 905         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 906
 907         if (!af1 || !af2)
 908                 return 0;
 909
 910         /* If the socket is IPv6 only, v4 addrs will not match */
 911         if (__ipv6_only_sock(sk) && af1 != af2)
 912                 return 0;
 913
 914         /* Today, wildcard AF_INET/AF_INET6. */
 915         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 916                 return 1;
 917
 918         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 919                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 920
 921         return __sctp_v6_cmp_addr(addr1, addr2);
 922 }
 923
 924 /* Verify that the provided sockaddr looks bindable.   Common verification,
 925  * has already been taken care of.
 926  */
 927 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 928 {
 929         struct sctp_af *af;
 930
 931         /* ASSERT: address family has already been verified. */
 932         if (addr->sa.sa_family != AF_INET6)
 933                 af = sctp_get_af_specific(addr->sa.sa_family);
 934         else {
 935                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 936                 struct net_device *dev;
 937
 938                 if (type & IPV6_ADDR_LINKLOCAL) {
 939                         struct net *net;
 940                         if (!addr->v6.sin6_scope_id)
 941                                 return 0;
 942                         net = sock_net(&opt->inet.sk);
 943                         rcu_read_lock();
 944                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 945                         if (!dev || !(opt->inet.freebind ||
 946                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 947                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 948                                                     dev, 0))) {
 949                                 rcu_read_unlock();
 950                                 return 0;
 951                         }
 952                         rcu_read_unlock();
 953                 }
 954
 955                 af = opt->pf->af;
 956         }
 957         return af->available(addr, opt);
 958 }
 959
 960 /* Verify that the provided sockaddr looks sendable.   Common verification,
 961  * has already been taken care of.
 962  */
 963 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 964 {
 965         struct sctp_af *af = NULL;
 966
 967         /* ASSERT: address family has already been verified. */
 968         if (addr->sa.sa_family != AF_INET6)
 969                 af = sctp_get_af_specific(addr->sa.sa_family);
 970         else {
 971                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 972                 struct net_device *dev;
 973
 974                 if (type & IPV6_ADDR_LINKLOCAL) {
 975                         if (!addr->v6.sin6_scope_id)
 976                                 return 0;
 977                         rcu_read_lock();
 978                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 979                                                    addr->v6.sin6_scope_id);
 980                         rcu_read_unlock();
 981                         if (!dev)
 982                                 return 0;
 983                 }
 984                 af = opt->pf->af;
 985         }
 986
 987         return af != NULL;
 988 }
 989
 990 /* Fill in Supported Address Type information for INIT and INIT-ACK
 991  * chunks.   Note: In the future, we may want to look at sock options
 992  * to determine whether a PF_INET6 socket really wants to have IPV4
 993  * addresses.
 994  * Returns number of addresses supported.
 995  */
 996 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 997                                       __be16 *types)
 998 {
 999         types[0] = SCTP_PARAM_IPV6_ADDRESS;
1000         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1001                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
1002                 return 2;
1003         }
1004         return 1;
1005 }
1006
1007 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1008 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1009                         int peer)
1010 {
1011         int rc;
1012
1013         rc = inet6_getname(sock, uaddr, peer);
1014
1015         if (rc < 0)
1016                 return rc;
1017
1018         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1019                                           (union sctp_addr *)uaddr);
1020
1021         return rc;
1022 }
1023
1024 static const struct proto_ops inet6_seqpacket_ops = {
1025         .family            = PF_INET6,
1026         .owner             = THIS_MODULE,
1027         .release           = inet6_release,
1028         .bind              = inet6_bind,
1029         .connect           = sctp_inet_connect,
1030         .socketpair        = sock_no_socketpair,
1031         .accept            = inet_accept,
1032         .getname           = sctp_getname,
1033         .poll              = sctp_poll,
1034         .ioctl             = inet6_ioctl,
1035         .listen            = sctp_inet_listen,
1036         .shutdown          = inet_shutdown,
1037         .setsockopt        = sock_common_setsockopt,
1038         .getsockopt        = sock_common_getsockopt,
1039         .sendmsg           = inet_sendmsg,
1040         .recvmsg           = inet_recvmsg,
1041         .mmap              = sock_no_mmap,
1042 #ifdef CONFIG_COMPAT
1043         .compat_setsockopt = compat_sock_common_setsockopt,
1044         .compat_getsockopt = compat_sock_common_getsockopt,
1045 #endif
1046 };
1047
1048 static struct inet_protosw sctpv6_seqpacket_protosw = {
1049         .type          = SOCK_SEQPACKET,
1050         .protocol      = IPPROTO_SCTP,
1051         .prot          = &sctpv6_prot,
1052         .ops           = &inet6_seqpacket_ops,
1053         .flags         = SCTP_PROTOSW_FLAG
1054 };
1055 static struct inet_protosw sctpv6_stream_protosw = {
1056         .type          = SOCK_STREAM,
1057         .protocol      = IPPROTO_SCTP,
1058         .prot          = &sctpv6_prot,
1059         .ops           = &inet6_seqpacket_ops,
1060         .flags         = SCTP_PROTOSW_FLAG,
1061 };
1062
1063 static int sctp6_rcv(struct sk_buff *skb)
1064 {
1065         return sctp_rcv(skb) ? -1 : 0;
1066 }
1067
1068 static const struct inet6_protocol sctpv6_protocol = {
1069         .handler      = sctp6_rcv,
1070         .err_handler  = sctp_v6_err,
1071         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1072 };
1073
1074 static struct sctp_af sctp_af_inet6 = {
1075         .sa_family         = AF_INET6,
1076         .sctp_xmit         = sctp_v6_xmit,
1077         .setsockopt        = ipv6_setsockopt,
1078         .getsockopt        = ipv6_getsockopt,
1079         .get_dst           = sctp_v6_get_dst,
1080         .get_saddr         = sctp_v6_get_saddr,
1081         .copy_addrlist     = sctp_v6_copy_addrlist,
1082         .from_skb          = sctp_v6_from_skb,
1083         .from_sk           = sctp_v6_from_sk,
1084         .from_addr_param   = sctp_v6_from_addr_param,
1085         .to_addr_param     = sctp_v6_to_addr_param,
1086         .cmp_addr          = sctp_v6_cmp_addr,
1087         .scope             = sctp_v6_scope,
1088         .addr_valid        = sctp_v6_addr_valid,
1089         .inaddr_any        = sctp_v6_inaddr_any,
1090         .is_any            = sctp_v6_is_any,
1091         .available         = sctp_v6_available,
1092         .skb_iif           = sctp_v6_skb_iif,
1093         .is_ce             = sctp_v6_is_ce,
1094         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1095         .ecn_capable       = sctp_v6_ecn_capable,
1096         .net_header_len    = sizeof(struct ipv6hdr),
1097         .sockaddr_len      = sizeof(struct sockaddr_in6),
1098         .ip_options_len    = sctp_v6_ip_options_len,
1099 #ifdef CONFIG_COMPAT
1100         .compat_setsockopt = compat_ipv6_setsockopt,
1101         .compat_getsockopt = compat_ipv6_getsockopt,
1102 #endif
1103 };
1104
1105 static struct sctp_pf sctp_pf_inet6 = {
1106         .event_msgname = sctp_inet6_event_msgname,
1107         .skb_msgname   = sctp_inet6_skb_msgname,
1108         .af_supported  = sctp_inet6_af_supported,
1109         .cmp_addr      = sctp_inet6_cmp_addr,
1110         .bind_verify   = sctp_inet6_bind_verify,
1111         .send_verify   = sctp_inet6_send_verify,
1112         .supported_addrs = sctp_inet6_supported_addrs,
1113         .create_accept_sk = sctp_v6_create_accept_sk,
1114         .addr_to_user  = sctp_v6_addr_to_user,
1115         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1116         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1117         .copy_ip_options = sctp_v6_copy_ip_options,
1118         .af            = &sctp_af_inet6,
1119 };
1120
1121 /* Initialize IPv6 support and register with socket layer.  */
1122 void sctp_v6_pf_init(void)
1123 {
1124         /* Register the SCTP specific PF_INET6 functions. */
1125         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1126
1127         /* Register the SCTP specific AF_INET6 functions. */
1128         sctp_register_af(&sctp_af_inet6);
1129 }
1130
1131 void sctp_v6_pf_exit(void)
1132 {
1133         list_del(&sctp_af_inet6.list);
1134 }
1135
1136 /* Initialize IPv6 support and register with socket layer.  */
1137 int sctp_v6_protosw_init(void)
1138 {
1139         int rc;
1140
1141         rc = proto_register(&sctpv6_prot, 1);
1142         if (rc)
1143                 return rc;
1144
1145         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1146         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1147         inet6_register_protosw(&sctpv6_stream_protosw);
1148
1149         return 0;
1150 }
1151
1152 void sctp_v6_protosw_exit(void)
1153 {
1154         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1155         inet6_unregister_protosw(&sctpv6_stream_protosw);
1156         proto_unregister(&sctpv6_prot);
1157 }
1158
1159
1160 /* Register with inet6 layer. */
1161 int sctp_v6_add_protocol(void)
1162 {
1163         /* Register notifier for inet6 address additions/deletions. */
1164         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1165
1166         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1167                 return -EAGAIN;
1168
1169         return 0;
1170 }
1171
1172 /* Unregister with inet6 layer. */
1173 void sctp_v6_del_protocol(void)
1174 {
1175         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1176         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1177 }