net/sctp/ipv6.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* SCTP kernel implementation
   3  * (C) Copyright IBM Corp. 2002, 2004
   4  * Copyright (c) 2001 Nokia, Inc.
   5  * Copyright (c) 2001 La Monte H.P. Yarroll
   6  * Copyright (c) 2002-2003 Intel Corp.
   7  *
   8  * This file is part of the SCTP kernel implementation
   9  *
  10  * SCTP over IPv6.
  11  *
  12  * Please send any bug reports or fixes you make to the
  13  * email address(es):
  14  *    lksctp developers <linux-sctp@vger.kernel.org>
  15  *
  16  * Written or modified by:
  17  *    Le Yanqun             <yanqun.le@nokia.com>
  18  *    Hui Huang             <hui.huang@nokia.com>
  19  *    La Monte H.P. Yarroll <piggy@acm.org>
  20  *    Sridhar Samudrala     <sri@us.ibm.com>
  21  *    Jon Grimm             <jgrimm@us.ibm.com>
  22  *    Ardelle Fan           <ardelle.fan@intel.com>
  23  *
  24  * Based on:
  25  *      linux/net/ipv6/tcp_ipv6.c
  26  */
  27
  28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  29
  30 #include <linux/module.h>
  31 #include <linux/errno.h>
  32 #include <linux/types.h>
  33 #include <linux/socket.h>
  34 #include <linux/sockios.h>
  35 #include <linux/net.h>
  36 #include <linux/in.h>
  37 #include <linux/in6.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/init.h>
  40 #include <linux/ipsec.h>
  41 #include <linux/slab.h>
  42
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46 #include <linux/seq_file.h>
  47
  48 #include <net/protocol.h>
  49 #include <net/ndisc.h>
  50 #include <net/ip.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/inet_common.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/sctp/sctp.h>
  58
  59 #include <linux/uaccess.h>
  60
  61 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  62                                          union sctp_addr *s2);
  63 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  64                               __be16 port);
  65 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  66                             const union sctp_addr *addr2);
  67
  68 /* Event handler for inet6 address addition/deletion events.
  69  * The sctp_local_addr_list needs to be protocted by a spin lock since
  70  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  71  * time and thus corrupt the list.
  72  * The reader side is protected with RCU.
  73  */
  74 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  75                                 void *ptr)
  76 {
  77         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  78         struct sctp_sockaddr_entry *addr = NULL;
  79         struct sctp_sockaddr_entry *temp;
  80         struct net *net = dev_net(ifa->idev->dev);
  81         int found = 0;
  82
  83         switch (ev) {
  84         case NETDEV_UP:
  85                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
  86                 if (addr) {
  87                         addr->a.v6.sin6_family = AF_INET6;
  88                         addr->a.v6.sin6_addr = ifa->addr;
  89                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
  90                         addr->valid = 1;
  91                         spin_lock_bh(&net->sctp.local_addr_lock);
  92                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
  93                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
  94                         spin_unlock_bh(&net->sctp.local_addr_lock);
  95                 }
  96                 break;
  97         case NETDEV_DOWN:
  98                 spin_lock_bh(&net->sctp.local_addr_lock);
  99                 list_for_each_entry_safe(addr, temp,
 100                                         &net->sctp.local_addr_list, list) {
 101                         if (addr->a.sa.sa_family == AF_INET6 &&
 102                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 103                                                 &ifa->addr)) {
 104                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 105                                 found = 1;
 106                                 addr->valid = 0;
 107                                 list_del_rcu(&addr->list);
 108                                 break;
 109                         }
 110                 }
 111                 spin_unlock_bh(&net->sctp.local_addr_lock);
 112                 if (found)
 113                         kfree_rcu(addr, rcu);
 114                 break;
 115         }
 116
 117         return NOTIFY_DONE;
 118 }
 119
 120 static struct notifier_block sctp_inet6addr_notifier = {
 121         .notifier_call = sctp_inet6addr_event,
 122 };
 123
 124 /* ICMP error handler. */
 125 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 126                         u8 type, u8 code, int offset, __be32 info)
 127 {
 128         struct inet6_dev *idev;
 129         struct sock *sk;
 130         struct sctp_association *asoc;
 131         struct sctp_transport *transport;
 132         struct ipv6_pinfo *np;
 133         __u16 saveip, savesctp;
 134         int err, ret = 0;
 135         struct net *net = dev_net(skb->dev);
 136
 137         idev = in6_dev_get(skb->dev);
 138
 139         /* Fix up skb to look at the embedded net header. */
 140         saveip   = skb->network_header;
 141         savesctp = skb->transport_header;
 142         skb_reset_network_header(skb);
 143         skb_set_transport_header(skb, offset);
 144         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 145         /* Put back, the original pointers. */
 146         skb->network_header   = saveip;
 147         skb->transport_header = savesctp;
 148         if (!sk) {
 149                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
 150                 ret = -ENOENT;
 151                 goto out;
 152         }
 153
 154         /* Warning:  The sock lock is held.  Remember to call
 155          * sctp_err_finish!
 156          */
 157
 158         switch (type) {
 159         case ICMPV6_PKT_TOOBIG:
 160                 if (ip6_sk_accept_pmtu(sk))
 161                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 162                 goto out_unlock;
 163         case ICMPV6_PARAMPROB:
 164                 if (ICMPV6_UNK_NEXTHDR == code) {
 165                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 166                         goto out_unlock;
 167                 }
 168                 break;
 169         case NDISC_REDIRECT:
 170                 sctp_icmp_redirect(sk, transport, skb);
 171                 goto out_unlock;
 172         default:
 173                 break;
 174         }
 175
 176         np = inet6_sk(sk);
 177         icmpv6_err_convert(type, code, &err);
 178         if (!sock_owned_by_user(sk) && np->recverr) {
 179                 sk->sk_err = err;
 180                 sk->sk_error_report(sk);
 181         } else {  /* Only an error on timeout */
 182                 sk->sk_err_soft = err;
 183         }
 184
 185 out_unlock:
 186         sctp_err_finish(sk, transport);
 187 out:
 188         if (likely(idev != NULL))
 189                 in6_dev_put(idev);
 190
 191         return ret;
 192 }
 193
 194 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 195 {
 196         struct sock *sk = skb->sk;
 197         struct ipv6_pinfo *np = inet6_sk(sk);
 198         struct flowi6 *fl6 = &transport->fl.u.ip6;
 199         __u8 tclass = np->tclass;
 200         int res;
 201
 202         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 203                  skb->len, &fl6->saddr, &fl6->daddr);
 204
 205         if (transport->dscp & SCTP_DSCP_SET_MASK)
 206                 tclass = transport->dscp & SCTP_DSCP_VAL_MASK;
 207
 208         if (INET_ECN_is_capable(tclass))
 209                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 210
 211         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 212                 skb->ignore_df = 1;
 213
 214         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 215
 216         rcu_read_lock();
 217         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
 218                        tclass);
 219         rcu_read_unlock();
 220         return res;
 221 }
 222
 223 /* Returns the dst cache entry for the given source and destination ip
 224  * addresses.
 225  */
 226 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 227                             struct flowi *fl, struct sock *sk)
 228 {
 229         struct sctp_association *asoc = t->asoc;
 230         struct dst_entry *dst = NULL;
 231         struct flowi6 *fl6 = &fl->u.ip6;
 232         struct sctp_bind_addr *bp;
 233         struct ipv6_pinfo *np = inet6_sk(sk);
 234         struct sctp_sockaddr_entry *laddr;
 235         union sctp_addr *daddr = &t->ipaddr;
 236         union sctp_addr dst_saddr;
 237         struct in6_addr *final_p, final;
 238         enum sctp_scope scope;
 239         __u8 matchlen = 0;
 240
 241         memset(fl6, 0, sizeof(struct flowi6));
 242         fl6->daddr = daddr->v6.sin6_addr;
 243         fl6->fl6_dport = daddr->v6.sin6_port;
 244         fl6->flowi6_proto = IPPROTO_SCTP;
 245         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 246                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 247         else if (asoc)
 248                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 249         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
 250                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 251
 252         if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
 253                 struct ip6_flowlabel *flowlabel;
 254
 255                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
 256                 if (!flowlabel)
 257                         goto out;
 258                 fl6_sock_release(flowlabel);
 259         }
 260
 261         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 262
 263         if (asoc)
 264                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 265
 266         if (saddr) {
 267                 fl6->saddr = saddr->v6.sin6_addr;
 268                 if (!fl6->fl6_sport)
 269                         fl6->fl6_sport = saddr->v6.sin6_port;
 270
 271                 pr_debug("src=%pI6 - ", &fl6->saddr);
 272         }
 273
 274         rcu_read_lock();
 275         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 276         rcu_read_unlock();
 277
 278         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 279         if (!asoc || saddr)
 280                 goto out;
 281
 282         bp = &asoc->base.bind_addr;
 283         scope = sctp_scope(daddr);
 284         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 285          * to see if we can use it.
 286          */
 287         if (!IS_ERR(dst)) {
 288                 /* Walk through the bind address list and look for a bind
 289                  * address that matches the source address of the returned dst.
 290                  */
 291                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 292                 rcu_read_lock();
 293                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 294                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 295                             (laddr->state != SCTP_ADDR_SRC &&
 296                              !asoc->src_out_of_asoc_ok))
 297                                 continue;
 298
 299                         /* Do not compare against v4 addrs */
 300                         if ((laddr->a.sa.sa_family == AF_INET6) &&
 301                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 302                                 rcu_read_unlock();
 303                                 goto out;
 304                         }
 305                 }
 306                 rcu_read_unlock();
 307                 /* None of the bound addresses match the source address of the
 308                  * dst. So release it.
 309                  */
 310                 dst_release(dst);
 311                 dst = NULL;
 312         }
 313
 314         /* Walk through the bind address list and try to get the
 315          * best source address for a given destination.
 316          */
 317         rcu_read_lock();
 318         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 319                 struct dst_entry *bdst;
 320                 __u8 bmatchlen;
 321
 322                 if (!laddr->valid ||
 323                     laddr->state != SCTP_ADDR_SRC ||
 324                     laddr->a.sa.sa_family != AF_INET6 ||
 325                     scope > sctp_scope(&laddr->a))
 326                         continue;
 327
 328                 fl6->saddr = laddr->a.v6.sin6_addr;
 329                 fl6->fl6_sport = laddr->a.v6.sin6_port;
 330                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 331                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
 332
 333                 if (IS_ERR(bdst))
 334                         continue;
 335
 336                 if (ipv6_chk_addr(dev_net(bdst->dev),
 337                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 338                         if (!IS_ERR_OR_NULL(dst))
 339                                 dst_release(dst);
 340                         dst = bdst;
 341                         break;
 342                 }
 343
 344                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 345                 if (matchlen > bmatchlen) {
 346                         dst_release(bdst);
 347                         continue;
 348                 }
 349
 350                 if (!IS_ERR_OR_NULL(dst))
 351                         dst_release(dst);
 352                 dst = bdst;
 353                 matchlen = bmatchlen;
 354         }
 355         rcu_read_unlock();
 356
 357 out:
 358         if (!IS_ERR_OR_NULL(dst)) {
 359                 struct rt6_info *rt;
 360
 361                 rt = (struct rt6_info *)dst;
 362                 t->dst = dst;
 363                 t->dst_cookie = rt6_get_cookie(rt);
 364                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 365                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 366                          &fl6->saddr);
 367         } else {
 368                 t->dst = NULL;
 369
 370                 pr_debug("no route\n");
 371         }
 372 }
 373
 374 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 375  * addresses.
 376  */
 377 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 378                                          union sctp_addr *s2)
 379 {
 380         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 381 }
 382
 383 /* Fills in the source address(saddr) based on the destination address(daddr)
 384  * and asoc's bind address list.
 385  */
 386 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 387                               struct sctp_transport *t,
 388                               struct flowi *fl)
 389 {
 390         struct flowi6 *fl6 = &fl->u.ip6;
 391         union sctp_addr *saddr = &t->saddr;
 392
 393         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 394
 395         if (t->dst) {
 396                 saddr->v6.sin6_family = AF_INET6;
 397                 saddr->v6.sin6_addr = fl6->saddr;
 398         }
 399 }
 400
 401 /* Make a copy of all potential local addresses. */
 402 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 403                                   struct net_device *dev)
 404 {
 405         struct inet6_dev *in6_dev;
 406         struct inet6_ifaddr *ifp;
 407         struct sctp_sockaddr_entry *addr;
 408
 409         rcu_read_lock();
 410         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 411                 rcu_read_unlock();
 412                 return;
 413         }
 414
 415         read_lock_bh(&in6_dev->lock);
 416         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 417                 /* Add the address to the local list.  */
 418                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 419                 if (addr) {
 420                         addr->a.v6.sin6_family = AF_INET6;
 421                         addr->a.v6.sin6_addr = ifp->addr;
 422                         addr->a.v6.sin6_scope_id = dev->ifindex;
 423                         addr->valid = 1;
 424                         INIT_LIST_HEAD(&addr->list);
 425                         list_add_tail(&addr->list, addrlist);
 426                 }
 427         }
 428
 429         read_unlock_bh(&in6_dev->lock);
 430         rcu_read_unlock();
 431 }
 432
 433 /* Copy over any ip options */
 434 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
 435 {
 436         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 437         struct ipv6_txoptions *opt;
 438
 439         newnp = inet6_sk(newsk);
 440
 441         rcu_read_lock();
 442         opt = rcu_dereference(np->opt);
 443         if (opt) {
 444                 opt = ipv6_dup_options(newsk, opt);
 445                 if (!opt)
 446                         pr_err("%s: Failed to copy ip options\n", __func__);
 447         }
 448         RCU_INIT_POINTER(newnp->opt, opt);
 449         rcu_read_unlock();
 450 }
 451
 452 /* Account for the IP options */
 453 static int sctp_v6_ip_options_len(struct sock *sk)
 454 {
 455         struct ipv6_pinfo *np = inet6_sk(sk);
 456         struct ipv6_txoptions *opt;
 457         int len = 0;
 458
 459         rcu_read_lock();
 460         opt = rcu_dereference(np->opt);
 461         if (opt)
 462                 len = opt->opt_flen + opt->opt_nflen;
 463
 464         rcu_read_unlock();
 465         return len;
 466 }
 467
 468 /* Initialize a sockaddr_storage from in incoming skb. */
 469 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 470                              int is_saddr)
 471 {
 472         /* Always called on head skb, so this is safe */
 473         struct sctphdr *sh = sctp_hdr(skb);
 474         struct sockaddr_in6 *sa = &addr->v6;
 475
 476         addr->v6.sin6_family = AF_INET6;
 477         addr->v6.sin6_flowinfo = 0; /* FIXME */
 478         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 479
 480         if (is_saddr) {
 481                 sa->sin6_port = sh->source;
 482                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
 483         } else {
 484                 sa->sin6_port = sh->dest;
 485                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
 486         }
 487 }
 488
 489 /* Initialize an sctp_addr from a socket. */
 490 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 491 {
 492         addr->v6.sin6_family = AF_INET6;
 493         addr->v6.sin6_port = 0;
 494         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 495 }
 496
 497 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 498 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 499 {
 500         if (addr->sa.sa_family == AF_INET) {
 501                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 502                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 503                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 504                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
 505                         addr->v4.sin_addr.s_addr;
 506         } else {
 507                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 508         }
 509 }
 510
 511 /* Initialize sk->sk_daddr from sctp_addr. */
 512 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 513 {
 514         if (addr->sa.sa_family == AF_INET) {
 515                 sk->sk_v6_daddr.s6_addr32[0] = 0;
 516                 sk->sk_v6_daddr.s6_addr32[1] = 0;
 517                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 518                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 519         } else {
 520                 sk->sk_v6_daddr = addr->v6.sin6_addr;
 521         }
 522 }
 523
 524 /* Initialize a sctp_addr from an address parameter. */
 525 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 526                                     union sctp_addr_param *param,
 527                                     __be16 port, int iif)
 528 {
 529         addr->v6.sin6_family = AF_INET6;
 530         addr->v6.sin6_port = port;
 531         addr->v6.sin6_flowinfo = 0; /* BUG */
 532         addr->v6.sin6_addr = param->v6.addr;
 533         addr->v6.sin6_scope_id = iif;
 534 }
 535
 536 /* Initialize an address parameter from a sctp_addr and return the length
 537  * of the address parameter.
 538  */
 539 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 540                                  union sctp_addr_param *param)
 541 {
 542         int length = sizeof(struct sctp_ipv6addr_param);
 543
 544         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 545         param->v6.param_hdr.length = htons(length);
 546         param->v6.addr = addr->v6.sin6_addr;
 547
 548         return length;
 549 }
 550
 551 /* Initialize a sctp_addr from struct in6_addr. */
 552 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 553                               __be16 port)
 554 {
 555         addr->sa.sa_family = AF_INET6;
 556         addr->v6.sin6_port = port;
 557         addr->v6.sin6_flowinfo = 0;
 558         addr->v6.sin6_addr = *saddr;
 559         addr->v6.sin6_scope_id = 0;
 560 }
 561
 562 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 563                               const union sctp_addr *addr2)
 564 {
 565         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 566                 if (addr1->sa.sa_family == AF_INET &&
 567                     addr2->sa.sa_family == AF_INET6 &&
 568                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 569                     addr2->v6.sin6_addr.s6_addr32[3] ==
 570                     addr1->v4.sin_addr.s_addr)
 571                         return 1;
 572
 573                 if (addr2->sa.sa_family == AF_INET &&
 574                     addr1->sa.sa_family == AF_INET6 &&
 575                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 576                     addr1->v6.sin6_addr.s6_addr32[3] ==
 577                     addr2->v4.sin_addr.s_addr)
 578                         return 1;
 579
 580                 return 0;
 581         }
 582
 583         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 584                 return 0;
 585
 586         /* If this is a linklocal address, compare the scope_id. */
 587         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 588             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 589             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 590                 return 0;
 591
 592         return 1;
 593 }
 594
 595 /* Compare addresses exactly.
 596  * v4-mapped-v6 is also in consideration.
 597  */
 598 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 599                             const union sctp_addr *addr2)
 600 {
 601         return __sctp_v6_cmp_addr(addr1, addr2) &&
 602                addr1->v6.sin6_port == addr2->v6.sin6_port;
 603 }
 604
 605 /* Initialize addr struct to INADDR_ANY. */
 606 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 607 {
 608         memset(addr, 0x00, sizeof(union sctp_addr));
 609         addr->v6.sin6_family = AF_INET6;
 610         addr->v6.sin6_port = port;
 611 }
 612
 613 /* Is this a wildcard address? */
 614 static int sctp_v6_is_any(const union sctp_addr *addr)
 615 {
 616         return ipv6_addr_any(&addr->v6.sin6_addr);
 617 }
 618
 619 /* Should this be available for binding?   */
 620 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 621 {
 622         int type;
 623         struct net *net = sock_net(&sp->inet.sk);
 624         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 625
 626         type = ipv6_addr_type(in6);
 627         if (IPV6_ADDR_ANY == type)
 628                 return 1;
 629         if (type == IPV6_ADDR_MAPPED) {
 630                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 631                         return 0;
 632                 sctp_v6_map_v4(addr);
 633                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 634         }
 635         if (!(type & IPV6_ADDR_UNICAST))
 636                 return 0;
 637
 638         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
 639                 ipv6_chk_addr(net, in6, NULL, 0);
 640 }
 641
 642 /* This function checks if the address is a valid address to be used for
 643  * SCTP.
 644  *
 645  * Output:
 646  * Return 0 - If the address is a non-unicast or an illegal address.
 647  * Return 1 - If the address is a unicast.
 648  */
 649 static int sctp_v6_addr_valid(union sctp_addr *addr,
 650                               struct sctp_sock *sp,
 651                               const struct sk_buff *skb)
 652 {
 653         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 654
 655         /* Support v4-mapped-v6 address. */
 656         if (ret == IPV6_ADDR_MAPPED) {
 657                 /* Note: This routine is used in input, so v4-mapped-v6
 658                  * are disallowed here when there is no sctp_sock.
 659                  */
 660                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 661                         return 0;
 662                 sctp_v6_map_v4(addr);
 663                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 664         }
 665
 666         /* Is this a non-unicast address */
 667         if (!(ret & IPV6_ADDR_UNICAST))
 668                 return 0;
 669
 670         return 1;
 671 }
 672
 673 /* What is the scope of 'addr'?  */
 674 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 675 {
 676         enum sctp_scope retval;
 677         int v6scope;
 678
 679         /* The IPv6 scope is really a set of bit fields.
 680          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 681          */
 682
 683         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 684         switch (v6scope) {
 685         case IFA_HOST:
 686                 retval = SCTP_SCOPE_LOOPBACK;
 687                 break;
 688         case IFA_LINK:
 689                 retval = SCTP_SCOPE_LINK;
 690                 break;
 691         case IFA_SITE:
 692                 retval = SCTP_SCOPE_PRIVATE;
 693                 break;
 694         default:
 695                 retval = SCTP_SCOPE_GLOBAL;
 696                 break;
 697         }
 698
 699         return retval;
 700 }
 701
 702 /* Create and initialize a new sk for the socket to be returned by accept(). */
 703 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 704                                              struct sctp_association *asoc,
 705                                              bool kern)
 706 {
 707         struct sock *newsk;
 708         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 709         struct sctp6_sock *newsctp6sk;
 710
 711         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
 712         if (!newsk)
 713                 goto out;
 714
 715         sock_init_data(NULL, newsk);
 716
 717         sctp_copy_sock(newsk, sk, asoc);
 718         sock_reset_flag(sk, SOCK_ZAPPED);
 719
 720         newsctp6sk = (struct sctp6_sock *)newsk;
 721         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 722
 723         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 724
 725         newnp = inet6_sk(newsk);
 726
 727         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 728         newnp->ipv6_mc_list = NULL;
 729         newnp->ipv6_ac_list = NULL;
 730         newnp->ipv6_fl_list = NULL;
 731
 732         sctp_v6_copy_ip_options(sk, newsk);
 733
 734         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 735          * and getpeername().
 736          */
 737         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 738
 739         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 740
 741         sk_refcnt_debug_inc(newsk);
 742
 743         if (newsk->sk_prot->init(newsk)) {
 744                 sk_common_release(newsk);
 745                 newsk = NULL;
 746         }
 747
 748 out:
 749         return newsk;
 750 }
 751
 752 /* Format a sockaddr for return to user space. This makes sure the return is
 753  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 754  */
 755 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 756 {
 757         if (sp->v4mapped) {
 758                 if (addr->sa.sa_family == AF_INET)
 759                         sctp_v4_map_v6(addr);
 760         } else {
 761                 if (addr->sa.sa_family == AF_INET6 &&
 762                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 763                         sctp_v6_map_v4(addr);
 764         }
 765
 766         if (addr->sa.sa_family == AF_INET) {
 767                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 768                 return sizeof(struct sockaddr_in);
 769         }
 770         return sizeof(struct sockaddr_in6);
 771 }
 772
 773 /* Where did this skb come from?  */
 774 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 775 {
 776         return IP6CB(skb)->iif;
 777 }
 778
 779 /* Was this packet marked by Explicit Congestion Notification? */
 780 static int sctp_v6_is_ce(const struct sk_buff *skb)
 781 {
 782         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 783 }
 784
 785 /* Dump the v6 addr to the seq file. */
 786 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 787 {
 788         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 789 }
 790
 791 static void sctp_v6_ecn_capable(struct sock *sk)
 792 {
 793         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 794 }
 795
 796 /* Initialize a PF_INET msgname from a ulpevent. */
 797 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 798                                      char *msgname, int *addrlen)
 799 {
 800         union sctp_addr *addr;
 801         struct sctp_association *asoc;
 802         union sctp_addr *paddr;
 803
 804         if (!msgname)
 805                 return;
 806
 807         addr = (union sctp_addr *)msgname;
 808         asoc = event->asoc;
 809         paddr = &asoc->peer.primary_addr;
 810
 811         if (paddr->sa.sa_family == AF_INET) {
 812                 addr->v4.sin_family = AF_INET;
 813                 addr->v4.sin_port = htons(asoc->peer.port);
 814                 addr->v4.sin_addr = paddr->v4.sin_addr;
 815         } else {
 816                 addr->v6.sin6_family = AF_INET6;
 817                 addr->v6.sin6_flowinfo = 0;
 818                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 819                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 820                 else
 821                         addr->v6.sin6_scope_id = 0;
 822                 addr->v6.sin6_port = htons(asoc->peer.port);
 823                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
 824         }
 825
 826         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 827 }
 828
 829 /* Initialize a msg_name from an inbound skb. */
 830 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 831                                    int *addr_len)
 832 {
 833         union sctp_addr *addr;
 834         struct sctphdr *sh;
 835
 836         if (!msgname)
 837                 return;
 838
 839         addr = (union sctp_addr *)msgname;
 840         sh = sctp_hdr(skb);
 841
 842         if (ip_hdr(skb)->version == 4) {
 843                 addr->v4.sin_family = AF_INET;
 844                 addr->v4.sin_port = sh->source;
 845                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 846         } else {
 847                 addr->v6.sin6_family = AF_INET6;
 848                 addr->v6.sin6_flowinfo = 0;
 849                 addr->v6.sin6_port = sh->source;
 850                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 851                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 852                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 853                 else
 854                         addr->v6.sin6_scope_id = 0;
 855         }
 856
 857         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 858 }
 859
 860 /* Do we support this AF? */
 861 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 862 {
 863         switch (family) {
 864         case AF_INET6:
 865                 return 1;
 866         /* v4-mapped-v6 addresses */
 867         case AF_INET:
 868                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 869                         return 1;
 870                 /* fallthru */
 871         default:
 872                 return 0;
 873         }
 874 }
 875
 876 /* Address matching with wildcards allowed.  This extra level
 877  * of indirection lets us choose whether a PF_INET6 should
 878  * disallow any v4 addresses if we so choose.
 879  */
 880 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 881                                const union sctp_addr *addr2,
 882                                struct sctp_sock *opt)
 883 {
 884         struct sock *sk = sctp_opt2sk(opt);
 885         struct sctp_af *af1, *af2;
 886
 887         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 888         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 889
 890         if (!af1 || !af2)
 891                 return 0;
 892
 893         /* If the socket is IPv6 only, v4 addrs will not match */
 894         if (__ipv6_only_sock(sk) && af1 != af2)
 895                 return 0;
 896
 897         /* Today, wildcard AF_INET/AF_INET6. */
 898         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 899                 return 1;
 900
 901         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 902                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 903
 904         return __sctp_v6_cmp_addr(addr1, addr2);
 905 }
 906
 907 /* Verify that the provided sockaddr looks bindable.   Common verification,
 908  * has already been taken care of.
 909  */
 910 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 911 {
 912         struct sctp_af *af;
 913
 914         /* ASSERT: address family has already been verified. */
 915         if (addr->sa.sa_family != AF_INET6)
 916                 af = sctp_get_af_specific(addr->sa.sa_family);
 917         else {
 918                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 919                 struct net_device *dev;
 920
 921                 if (type & IPV6_ADDR_LINKLOCAL) {
 922                         struct net *net;
 923                         if (!addr->v6.sin6_scope_id)
 924                                 return 0;
 925                         net = sock_net(&opt->inet.sk);
 926                         rcu_read_lock();
 927                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 928                         if (!dev || !(opt->inet.freebind ||
 929                                       net->ipv6.sysctl.ip_nonlocal_bind ||
 930                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
 931                                                     dev, 0))) {
 932                                 rcu_read_unlock();
 933                                 return 0;
 934                         }
 935                         rcu_read_unlock();
 936                 }
 937
 938                 af = opt->pf->af;
 939         }
 940         return af->available(addr, opt);
 941 }
 942
 943 /* Verify that the provided sockaddr looks sendable.   Common verification,
 944  * has already been taken care of.
 945  */
 946 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 947 {
 948         struct sctp_af *af = NULL;
 949
 950         /* ASSERT: address family has already been verified. */
 951         if (addr->sa.sa_family != AF_INET6)
 952                 af = sctp_get_af_specific(addr->sa.sa_family);
 953         else {
 954                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 955                 struct net_device *dev;
 956
 957                 if (type & IPV6_ADDR_LINKLOCAL) {
 958                         if (!addr->v6.sin6_scope_id)
 959                                 return 0;
 960                         rcu_read_lock();
 961                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 962                                                    addr->v6.sin6_scope_id);
 963                         rcu_read_unlock();
 964                         if (!dev)
 965                                 return 0;
 966                 }
 967                 af = opt->pf->af;
 968         }
 969
 970         return af != NULL;
 971 }
 972
 973 /* Fill in Supported Address Type information for INIT and INIT-ACK
 974  * chunks.   Note: In the future, we may want to look at sock options
 975  * to determine whether a PF_INET6 socket really wants to have IPV4
 976  * addresses.
 977  * Returns number of addresses supported.
 978  */
 979 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 980                                       __be16 *types)
 981 {
 982         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 983         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 984                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 985                 return 2;
 986         }
 987         return 1;
 988 }
 989
 990 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
 991 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
 992                         int peer)
 993 {
 994         int rc;
 995
 996         rc = inet6_getname(sock, uaddr, peer);
 997
 998         if (rc < 0)
 999                 return rc;
1000
1001         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1002                                           (union sctp_addr *)uaddr);
1003
1004         return rc;
1005 }
1006
1007 static const struct proto_ops inet6_seqpacket_ops = {
1008         .family            = PF_INET6,
1009         .owner             = THIS_MODULE,
1010         .release           = inet6_release,
1011         .bind              = inet6_bind,
1012         .connect           = sctp_inet_connect,
1013         .socketpair        = sock_no_socketpair,
1014         .accept            = inet_accept,
1015         .getname           = sctp_getname,
1016         .poll              = sctp_poll,
1017         .ioctl             = inet6_ioctl,
1018         .gettstamp         = sock_gettstamp,
1019         .listen            = sctp_inet_listen,
1020         .shutdown          = inet_shutdown,
1021         .setsockopt        = sock_common_setsockopt,
1022         .getsockopt        = sock_common_getsockopt,
1023         .sendmsg           = inet_sendmsg,
1024         .recvmsg           = inet_recvmsg,
1025         .mmap              = sock_no_mmap,
1026 #ifdef CONFIG_COMPAT
1027         .compat_setsockopt = compat_sock_common_setsockopt,
1028         .compat_getsockopt = compat_sock_common_getsockopt,
1029 #endif
1030 };
1031
1032 static struct inet_protosw sctpv6_seqpacket_protosw = {
1033         .type          = SOCK_SEQPACKET,
1034         .protocol      = IPPROTO_SCTP,
1035         .prot          = &sctpv6_prot,
1036         .ops           = &inet6_seqpacket_ops,
1037         .flags         = SCTP_PROTOSW_FLAG
1038 };
1039 static struct inet_protosw sctpv6_stream_protosw = {
1040         .type          = SOCK_STREAM,
1041         .protocol      = IPPROTO_SCTP,
1042         .prot          = &sctpv6_prot,
1043         .ops           = &inet6_seqpacket_ops,
1044         .flags         = SCTP_PROTOSW_FLAG,
1045 };
1046
1047 static int sctp6_rcv(struct sk_buff *skb)
1048 {
1049         return sctp_rcv(skb) ? -1 : 0;
1050 }
1051
1052 static const struct inet6_protocol sctpv6_protocol = {
1053         .handler      = sctp6_rcv,
1054         .err_handler  = sctp_v6_err,
1055         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1056 };
1057
1058 static struct sctp_af sctp_af_inet6 = {
1059         .sa_family         = AF_INET6,
1060         .sctp_xmit         = sctp_v6_xmit,
1061         .setsockopt        = ipv6_setsockopt,
1062         .getsockopt        = ipv6_getsockopt,
1063         .get_dst           = sctp_v6_get_dst,
1064         .get_saddr         = sctp_v6_get_saddr,
1065         .copy_addrlist     = sctp_v6_copy_addrlist,
1066         .from_skb          = sctp_v6_from_skb,
1067         .from_sk           = sctp_v6_from_sk,
1068         .from_addr_param   = sctp_v6_from_addr_param,
1069         .to_addr_param     = sctp_v6_to_addr_param,
1070         .cmp_addr          = sctp_v6_cmp_addr,
1071         .scope             = sctp_v6_scope,
1072         .addr_valid        = sctp_v6_addr_valid,
1073         .inaddr_any        = sctp_v6_inaddr_any,
1074         .is_any            = sctp_v6_is_any,
1075         .available         = sctp_v6_available,
1076         .skb_iif           = sctp_v6_skb_iif,
1077         .is_ce             = sctp_v6_is_ce,
1078         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1079         .ecn_capable       = sctp_v6_ecn_capable,
1080         .net_header_len    = sizeof(struct ipv6hdr),
1081         .sockaddr_len      = sizeof(struct sockaddr_in6),
1082         .ip_options_len    = sctp_v6_ip_options_len,
1083 #ifdef CONFIG_COMPAT
1084         .compat_setsockopt = compat_ipv6_setsockopt,
1085         .compat_getsockopt = compat_ipv6_getsockopt,
1086 #endif
1087 };
1088
1089 static struct sctp_pf sctp_pf_inet6 = {
1090         .event_msgname = sctp_inet6_event_msgname,
1091         .skb_msgname   = sctp_inet6_skb_msgname,
1092         .af_supported  = sctp_inet6_af_supported,
1093         .cmp_addr      = sctp_inet6_cmp_addr,
1094         .bind_verify   = sctp_inet6_bind_verify,
1095         .send_verify   = sctp_inet6_send_verify,
1096         .supported_addrs = sctp_inet6_supported_addrs,
1097         .create_accept_sk = sctp_v6_create_accept_sk,
1098         .addr_to_user  = sctp_v6_addr_to_user,
1099         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1100         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1101         .copy_ip_options = sctp_v6_copy_ip_options,
1102         .af            = &sctp_af_inet6,
1103 };
1104
1105 /* Initialize IPv6 support and register with socket layer.  */
1106 void sctp_v6_pf_init(void)
1107 {
1108         /* Register the SCTP specific PF_INET6 functions. */
1109         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1110
1111         /* Register the SCTP specific AF_INET6 functions. */
1112         sctp_register_af(&sctp_af_inet6);
1113 }
1114
1115 void sctp_v6_pf_exit(void)
1116 {
1117         list_del(&sctp_af_inet6.list);
1118 }
1119
1120 /* Initialize IPv6 support and register with socket layer.  */
1121 int sctp_v6_protosw_init(void)
1122 {
1123         int rc;
1124
1125         rc = proto_register(&sctpv6_prot, 1);
1126         if (rc)
1127                 return rc;
1128
1129         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1130         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1131         inet6_register_protosw(&sctpv6_stream_protosw);
1132
1133         return 0;
1134 }
1135
1136 void sctp_v6_protosw_exit(void)
1137 {
1138         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1139         inet6_unregister_protosw(&sctpv6_stream_protosw);
1140         proto_unregister(&sctpv6_prot);
1141 }
1142
1143
1144 /* Register with inet6 layer. */
1145 int sctp_v6_add_protocol(void)
1146 {
1147         /* Register notifier for inet6 address additions/deletions. */
1148         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1149
1150         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1151                 return -EAGAIN;
1152
1153         return 0;
1154 }
1155
1156 /* Unregister with inet6 layer. */
1157 void sctp_v6_del_protocol(void)
1158 {
1159         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1160         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1161 }