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   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, write to
  25  * the Free Software Foundation, 59 Temple Place - Suite 330,
  26  * Boston, MA 02111-1307, USA.
  27  *
  28  * Please send any bug reports or fixes you make to the
  29  * email address(es):
  30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  31  *
  32  * Or submit a bug report through the following website:
  33  *    http://www.sf.net/projects/lksctp
  34  *
  35  * Written or modified by:
  36  *    Le Yanqun             <yanqun.le@nokia.com>
  37  *    Hui Huang             <hui.huang@nokia.com>
  38  *    La Monte H.P. Yarroll <piggy@acm.org>
  39  *    Sridhar Samudrala     <sri@us.ibm.com>
  40  *    Jon Grimm             <jgrimm@us.ibm.com>
  41  *    Ardelle Fan           <ardelle.fan@intel.com>
  42  *
  43  * Based on:
  44  *      linux/net/ipv6/tcp_ipv6.c
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/module.h>
  51 #include <linux/errno.h>
  52 #include <linux/types.h>
  53 #include <linux/socket.h>
  54 #include <linux/sockios.h>
  55 #include <linux/net.h>
  56 #include <linux/in.h>
  57 #include <linux/in6.h>
  58 #include <linux/netdevice.h>
  59 #include <linux/init.h>
  60 #include <linux/ipsec.h>
  61
  62 #include <linux/ipv6.h>
  63 #include <linux/icmpv6.h>
  64 #include <linux/random.h>
  65 #include <linux/seq_file.h>
  66
  67 #include <net/protocol.h>
  68 #include <net/ndisc.h>
  69 #include <net/ip.h>
  70 #include <net/ipv6.h>
  71 #include <net/transp_v6.h>
  72 #include <net/addrconf.h>
  73 #include <net/ip6_route.h>
  74 #include <net/inet_common.h>
  75 #include <net/inet_ecn.h>
  76 #include <net/sctp/sctp.h>
  77
  78 #include <asm/uaccess.h>
  79
  80 /* Event handler for inet6 address addition/deletion events.
  81  * The sctp_local_addr_list needs to be protocted by a spin lock since
  82  * multiple notifiers (say IPv4 and IPv6) may be running at the same
  83  * time and thus corrupt the list.
  84  * The reader side is protected with RCU.
  85  */
  86 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  87                                 void *ptr)
  88 {
  89         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  90         struct sctp_sockaddr_entry *addr = NULL;
  91         struct sctp_sockaddr_entry *temp;
  92         int found = 0;
  93
  94         switch (ev) {
  95         case NETDEV_UP:
  96                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  97                 if (addr) {
  98                         addr->a.v6.sin6_family = AF_INET6;
  99                         addr->a.v6.sin6_port = 0;
 100                         memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
 101                                  sizeof(struct in6_addr));
 102                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 103                         addr->valid = 1;
 104                         spin_lock_bh(&sctp_local_addr_lock);
 105                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
 106                         spin_unlock_bh(&sctp_local_addr_lock);
 107                 }
 108                 break;
 109         case NETDEV_DOWN:
 110                 spin_lock_bh(&sctp_local_addr_lock);
 111                 list_for_each_entry_safe(addr, temp,
 112                                         &sctp_local_addr_list, list) {
 113                         if (addr->a.sa.sa_family == AF_INET6 &&
 114                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 115                                                 &ifa->addr)) {
 116                                 found = 1;
 117                                 addr->valid = 0;
 118                                 list_del_rcu(&addr->list);
 119                                 break;
 120                         }
 121                 }
 122                 spin_unlock_bh(&sctp_local_addr_lock);
 123                 if (found)
 124                         call_rcu(&addr->rcu, sctp_local_addr_free);
 125                 break;
 126         }
 127
 128         return NOTIFY_DONE;
 129 }
 130
 131 static struct notifier_block sctp_inet6addr_notifier = {
 132         .notifier_call = sctp_inet6addr_event,
 133 };
 134
 135 /* ICMP error handler. */
 136 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 137                              int type, int code, int offset, __be32 info)
 138 {
 139         struct inet6_dev *idev;
 140         struct sock *sk;
 141         struct sctp_association *asoc;
 142         struct sctp_transport *transport;
 143         struct ipv6_pinfo *np;
 144         sk_buff_data_t saveip, savesctp;
 145         int err;
 146
 147         idev = in6_dev_get(skb->dev);
 148
 149         /* Fix up skb to look at the embedded net header. */
 150         saveip   = skb->network_header;
 151         savesctp = skb->transport_header;
 152         skb_reset_network_header(skb);
 153         skb_set_transport_header(skb, offset);
 154         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 155         /* Put back, the original pointers. */
 156         skb->network_header   = saveip;
 157         skb->transport_header = savesctp;
 158         if (!sk) {
 159                 ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
 160                 goto out;
 161         }
 162
 163         /* Warning:  The sock lock is held.  Remember to call
 164          * sctp_err_finish!
 165          */
 166
 167         switch (type) {
 168         case ICMPV6_PKT_TOOBIG:
 169                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 170                 goto out_unlock;
 171         case ICMPV6_PARAMPROB:
 172                 if (ICMPV6_UNK_NEXTHDR == code) {
 173                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 174                         goto out_unlock;
 175                 }
 176                 break;
 177         default:
 178                 break;
 179         }
 180
 181         np = inet6_sk(sk);
 182         icmpv6_err_convert(type, code, &err);
 183         if (!sock_owned_by_user(sk) && np->recverr) {
 184                 sk->sk_err = err;
 185                 sk->sk_error_report(sk);
 186         } else {  /* Only an error on timeout */
 187                 sk->sk_err_soft = err;
 188         }
 189
 190 out_unlock:
 191         sctp_err_finish(sk, asoc);
 192 out:
 193         if (likely(idev != NULL))
 194                 in6_dev_put(idev);
 195 }
 196
 197 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 198 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 199 {
 200         struct sock *sk = skb->sk;
 201         struct ipv6_pinfo *np = inet6_sk(sk);
 202         struct flowi fl;
 203
 204         memset(&fl, 0, sizeof(fl));
 205
 206         fl.proto = sk->sk_protocol;
 207
 208         /* Fill in the dest address from the route entry passed with the skb
 209          * and the source address from the transport.
 210          */
 211         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 212         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 213
 214         fl.fl6_flowlabel = np->flow_label;
 215         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 216         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 217                 fl.oif = transport->saddr.v6.sin6_scope_id;
 218         else
 219                 fl.oif = sk->sk_bound_dev_if;
 220
 221         if (np->opt && np->opt->srcrt) {
 222                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 223                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 224         }
 225
 226         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 227                           __func__, skb, skb->len,
 228                           &fl.fl6_src, &fl.fl6_dst);
 229
 230         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 231
 232         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 233                 skb->local_df = 1;
 234
 235         return ip6_xmit(sk, skb, &fl, np->opt, 0);
 236 }
 237
 238 /* Returns the dst cache entry for the given source and destination ip
 239  * addresses.
 240  */
 241 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 242                                          union sctp_addr *daddr,
 243                                          union sctp_addr *saddr)
 244 {
 245         struct dst_entry *dst;
 246         struct flowi fl;
 247
 248         memset(&fl, 0, sizeof(fl));
 249         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 250         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 251                 fl.oif = daddr->v6.sin6_scope_id;
 252
 253
 254         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl.fl6_dst);
 255
 256         if (saddr) {
 257                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 258                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl.fl6_src);
 259         }
 260
 261         dst = ip6_route_output(&init_net, NULL, &fl);
 262         if (!dst->error) {
 263                 struct rt6_info *rt;
 264                 rt = (struct rt6_info *)dst;
 265                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 266                         &rt->rt6i_dst.addr, &rt->rt6i_src.addr);
 267                 return dst;
 268         }
 269         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 270         dst_release(dst);
 271         return NULL;
 272 }
 273
 274 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 275  * addresses.
 276  */
 277 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 278                                          union sctp_addr *s2)
 279 {
 280         struct in6_addr *a1 = &s1->v6.sin6_addr;
 281         struct in6_addr *a2 = &s2->v6.sin6_addr;
 282         int i, j;
 283
 284         for (i = 0; i < 4 ; i++) {
 285                 __be32 a1xora2;
 286
 287                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 288
 289                 if ((j = fls(ntohl(a1xora2))))
 290                         return (i * 32 + 32 - j);
 291         }
 292
 293         return (i*32);
 294 }
 295
 296 /* Fills in the source address(saddr) based on the destination address(daddr)
 297  * and asoc's bind address list.
 298  */
 299 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 300                               struct sctp_association *asoc,
 301                               struct dst_entry *dst,
 302                               union sctp_addr *daddr,
 303                               union sctp_addr *saddr)
 304 {
 305         struct sctp_bind_addr *bp;
 306         struct sctp_sockaddr_entry *laddr;
 307         sctp_scope_t scope;
 308         union sctp_addr *baddr = NULL;
 309         __u8 matchlen = 0;
 310         __u8 bmatchlen;
 311
 312         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p daddr:%pI6 ",
 313                           __func__, asoc, dst, &daddr->v6.sin6_addr);
 314
 315         if (!asoc) {
 316                 ipv6_dev_get_saddr(sock_net(sctp_opt2sk(sk)),
 317                                    dst ? ip6_dst_idev(dst)->dev : NULL,
 318                                    &daddr->v6.sin6_addr,
 319                                    inet6_sk(&sk->inet.sk)->srcprefs,
 320                                    &saddr->v6.sin6_addr);
 321                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: %pI6\n",
 322                                   &saddr->v6.sin6_addr);
 323                 return;
 324         }
 325
 326         scope = sctp_scope(daddr);
 327
 328         bp = &asoc->base.bind_addr;
 329
 330         /* Go through the bind address list and find the best source address
 331          * that matches the scope of the destination address.
 332          */
 333         rcu_read_lock();
 334         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 335                 if (!laddr->valid)
 336                         continue;
 337                 if ((laddr->state == SCTP_ADDR_SRC) &&
 338                     (laddr->a.sa.sa_family == AF_INET6) &&
 339                     (scope <= sctp_scope(&laddr->a))) {
 340                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 341                         if (!baddr || (matchlen < bmatchlen)) {
 342                                 baddr = &laddr->a;
 343                                 matchlen = bmatchlen;
 344                         }
 345                 }
 346         }
 347
 348         if (baddr) {
 349                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 350                 SCTP_DEBUG_PRINTK("saddr: %pI6\n", &saddr->v6.sin6_addr);
 351         } else {
 352                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 353                        "address for the dest:%pI6\n",
 354                        __func__, asoc, &daddr->v6.sin6_addr);
 355         }
 356
 357         rcu_read_unlock();
 358 }
 359
 360 /* Make a copy of all potential local addresses. */
 361 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 362                                   struct net_device *dev)
 363 {
 364         struct inet6_dev *in6_dev;
 365         struct inet6_ifaddr *ifp;
 366         struct sctp_sockaddr_entry *addr;
 367
 368         rcu_read_lock();
 369         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 370                 rcu_read_unlock();
 371                 return;
 372         }
 373
 374         read_lock_bh(&in6_dev->lock);
 375         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 376                 /* Add the address to the local list.  */
 377                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 378                 if (addr) {
 379                         addr->a.v6.sin6_family = AF_INET6;
 380                         addr->a.v6.sin6_port = 0;
 381                         addr->a.v6.sin6_addr = ifp->addr;
 382                         addr->a.v6.sin6_scope_id = dev->ifindex;
 383                         addr->valid = 1;
 384                         INIT_LIST_HEAD(&addr->list);
 385                         INIT_RCU_HEAD(&addr->rcu);
 386                         list_add_tail(&addr->list, addrlist);
 387                 }
 388         }
 389
 390         read_unlock_bh(&in6_dev->lock);
 391         rcu_read_unlock();
 392 }
 393
 394 /* Initialize a sockaddr_storage from in incoming skb. */
 395 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 396                              int is_saddr)
 397 {
 398         void *from;
 399         __be16 *port;
 400         struct sctphdr *sh;
 401
 402         port = &addr->v6.sin6_port;
 403         addr->v6.sin6_family = AF_INET6;
 404         addr->v6.sin6_flowinfo = 0; /* FIXME */
 405         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 406
 407         sh = sctp_hdr(skb);
 408         if (is_saddr) {
 409                 *port  = sh->source;
 410                 from = &ipv6_hdr(skb)->saddr;
 411         } else {
 412                 *port = sh->dest;
 413                 from = &ipv6_hdr(skb)->daddr;
 414         }
 415         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 416 }
 417
 418 /* Initialize an sctp_addr from a socket. */
 419 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 420 {
 421         addr->v6.sin6_family = AF_INET6;
 422         addr->v6.sin6_port = 0;
 423         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 424 }
 425
 426 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 427 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 428 {
 429         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 430                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 431                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 432                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 433                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 434                         addr->v4.sin_addr.s_addr;
 435         } else {
 436                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 437         }
 438 }
 439
 440 /* Initialize sk->sk_daddr from sctp_addr. */
 441 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 442 {
 443         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 444                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 445                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 446                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 447                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 448         } else {
 449                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 450         }
 451 }
 452
 453 /* Initialize a sctp_addr from an address parameter. */
 454 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 455                                     union sctp_addr_param *param,
 456                                     __be16 port, int iif)
 457 {
 458         addr->v6.sin6_family = AF_INET6;
 459         addr->v6.sin6_port = port;
 460         addr->v6.sin6_flowinfo = 0; /* BUG */
 461         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 462         addr->v6.sin6_scope_id = iif;
 463 }
 464
 465 /* Initialize an address parameter from a sctp_addr and return the length
 466  * of the address parameter.
 467  */
 468 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 469                                  union sctp_addr_param *param)
 470 {
 471         int length = sizeof(sctp_ipv6addr_param_t);
 472
 473         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 474         param->v6.param_hdr.length = htons(length);
 475         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 476
 477         return length;
 478 }
 479
 480 /* Initialize a sctp_addr from a dst_entry. */
 481 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 482                               __be16 port)
 483 {
 484         struct rt6_info *rt = (struct rt6_info *)dst;
 485         addr->sa.sa_family = AF_INET6;
 486         addr->v6.sin6_port = port;
 487         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 488 }
 489
 490 /* Compare addresses exactly.
 491  * v4-mapped-v6 is also in consideration.
 492  */
 493 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 494                             const union sctp_addr *addr2)
 495 {
 496         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 497                 if (addr1->sa.sa_family == AF_INET &&
 498                     addr2->sa.sa_family == AF_INET6 &&
 499                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 500                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 501                             addr2->v6.sin6_addr.s6_addr32[3] ==
 502                             addr1->v4.sin_addr.s_addr)
 503                                 return 1;
 504                 }
 505                 if (addr2->sa.sa_family == AF_INET &&
 506                     addr1->sa.sa_family == AF_INET6 &&
 507                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 508                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 509                             addr1->v6.sin6_addr.s6_addr32[3] ==
 510                             addr2->v4.sin_addr.s_addr)
 511                                 return 1;
 512                 }
 513                 return 0;
 514         }
 515         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 516                 return 0;
 517         /* If this is a linklocal address, compare the scope_id. */
 518         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 519                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 520                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 521                         return 0;
 522                 }
 523         }
 524
 525         return 1;
 526 }
 527
 528 /* Initialize addr struct to INADDR_ANY. */
 529 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 530 {
 531         memset(addr, 0x00, sizeof(union sctp_addr));
 532         addr->v6.sin6_family = AF_INET6;
 533         addr->v6.sin6_port = port;
 534 }
 535
 536 /* Is this a wildcard address? */
 537 static int sctp_v6_is_any(const union sctp_addr *addr)
 538 {
 539         return ipv6_addr_any(&addr->v6.sin6_addr);
 540 }
 541
 542 /* Should this be available for binding?   */
 543 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 544 {
 545         int type;
 546         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 547
 548         type = ipv6_addr_type(in6);
 549         if (IPV6_ADDR_ANY == type)
 550                 return 1;
 551         if (type == IPV6_ADDR_MAPPED) {
 552                 if (sp && !sp->v4mapped)
 553                         return 0;
 554                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 555                         return 0;
 556                 sctp_v6_map_v4(addr);
 557                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 558         }
 559         if (!(type & IPV6_ADDR_UNICAST))
 560                 return 0;
 561
 562         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 563 }
 564
 565 /* This function checks if the address is a valid address to be used for
 566  * SCTP.
 567  *
 568  * Output:
 569  * Return 0 - If the address is a non-unicast or an illegal address.
 570  * Return 1 - If the address is a unicast.
 571  */
 572 static int sctp_v6_addr_valid(union sctp_addr *addr,
 573                               struct sctp_sock *sp,
 574                               const struct sk_buff *skb)
 575 {
 576         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 577
 578         /* Support v4-mapped-v6 address. */
 579         if (ret == IPV6_ADDR_MAPPED) {
 580                 /* Note: This routine is used in input, so v4-mapped-v6
 581                  * are disallowed here when there is no sctp_sock.
 582                  */
 583                 if (!sp || !sp->v4mapped)
 584                         return 0;
 585                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 586                         return 0;
 587                 sctp_v6_map_v4(addr);
 588                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 589         }
 590
 591         /* Is this a non-unicast address */
 592         if (!(ret & IPV6_ADDR_UNICAST))
 593                 return 0;
 594
 595         return 1;
 596 }
 597
 598 /* What is the scope of 'addr'?  */
 599 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 600 {
 601         int v6scope;
 602         sctp_scope_t retval;
 603
 604         /* The IPv6 scope is really a set of bit fields.
 605          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 606          */
 607
 608         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 609         switch (v6scope) {
 610         case IFA_HOST:
 611                 retval = SCTP_SCOPE_LOOPBACK;
 612                 break;
 613         case IFA_LINK:
 614                 retval = SCTP_SCOPE_LINK;
 615                 break;
 616         case IFA_SITE:
 617                 retval = SCTP_SCOPE_PRIVATE;
 618                 break;
 619         default:
 620                 retval = SCTP_SCOPE_GLOBAL;
 621                 break;
 622         }
 623
 624         return retval;
 625 }
 626
 627 /* Create and initialize a new sk for the socket to be returned by accept(). */
 628 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 629                                              struct sctp_association *asoc)
 630 {
 631         struct inet_sock *inet = inet_sk(sk);
 632         struct sock *newsk;
 633         struct inet_sock *newinet;
 634         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 635         struct sctp6_sock *newsctp6sk;
 636
 637         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 638         if (!newsk)
 639                 goto out;
 640
 641         sock_init_data(NULL, newsk);
 642
 643         newsk->sk_type = SOCK_STREAM;
 644
 645         newsk->sk_prot = sk->sk_prot;
 646         newsk->sk_no_check = sk->sk_no_check;
 647         newsk->sk_reuse = sk->sk_reuse;
 648
 649         newsk->sk_destruct = inet_sock_destruct;
 650         newsk->sk_family = PF_INET6;
 651         newsk->sk_protocol = IPPROTO_SCTP;
 652         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 653         newsk->sk_shutdown = sk->sk_shutdown;
 654         sock_reset_flag(sk, SOCK_ZAPPED);
 655
 656         newsctp6sk = (struct sctp6_sock *)newsk;
 657         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 658
 659         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 660
 661         newinet = inet_sk(newsk);
 662         newnp = inet6_sk(newsk);
 663
 664         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 665
 666         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 667          * and getpeername().
 668          */
 669         newinet->sport = inet->sport;
 670         newnp->saddr = np->saddr;
 671         newnp->rcv_saddr = np->rcv_saddr;
 672         newinet->dport = htons(asoc->peer.port);
 673         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 674
 675         /* Init the ipv4 part of the socket since we can have sockets
 676          * using v6 API for ipv4.
 677          */
 678         newinet->uc_ttl = -1;
 679         newinet->mc_loop = 1;
 680         newinet->mc_ttl = 1;
 681         newinet->mc_index = 0;
 682         newinet->mc_list = NULL;
 683
 684         if (ipv4_config.no_pmtu_disc)
 685                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 686         else
 687                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 688
 689         sk_refcnt_debug_inc(newsk);
 690
 691         if (newsk->sk_prot->init(newsk)) {
 692                 sk_common_release(newsk);
 693                 newsk = NULL;
 694         }
 695
 696 out:
 697         return newsk;
 698 }
 699
 700 /* Map v4 address to mapped v6 address */
 701 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 702 {
 703         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 704                 sctp_v4_map_v6(addr);
 705 }
 706
 707 /* Where did this skb come from?  */
 708 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 709 {
 710         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 711         return opt->iif;
 712 }
 713
 714 /* Was this packet marked by Explicit Congestion Notification? */
 715 static int sctp_v6_is_ce(const struct sk_buff *skb)
 716 {
 717         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 718 }
 719
 720 /* Dump the v6 addr to the seq file. */
 721 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 722 {
 723         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 724 }
 725
 726 static void sctp_v6_ecn_capable(struct sock *sk)
 727 {
 728         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 729 }
 730
 731 /* Initialize a PF_INET6 socket msg_name. */
 732 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 733 {
 734         struct sockaddr_in6 *sin6;
 735
 736         sin6 = (struct sockaddr_in6 *)msgname;
 737         sin6->sin6_family = AF_INET6;
 738         sin6->sin6_flowinfo = 0;
 739         sin6->sin6_scope_id = 0; /*FIXME */
 740         *addr_len = sizeof(struct sockaddr_in6);
 741 }
 742
 743 /* Initialize a PF_INET msgname from a ulpevent. */
 744 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 745                                      char *msgname, int *addrlen)
 746 {
 747         struct sockaddr_in6 *sin6, *sin6from;
 748
 749         if (msgname) {
 750                 union sctp_addr *addr;
 751                 struct sctp_association *asoc;
 752
 753                 asoc = event->asoc;
 754                 sctp_inet6_msgname(msgname, addrlen);
 755                 sin6 = (struct sockaddr_in6 *)msgname;
 756                 sin6->sin6_port = htons(asoc->peer.port);
 757                 addr = &asoc->peer.primary_addr;
 758
 759                 /* Note: If we go to a common v6 format, this code
 760                  * will change.
 761                  */
 762
 763                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 764                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 765                     AF_INET == addr->sa.sa_family) {
 766                         sctp_v4_map_v6((union sctp_addr *)sin6);
 767                         sin6->sin6_addr.s6_addr32[3] =
 768                                 addr->v4.sin_addr.s_addr;
 769                         return;
 770                 }
 771
 772                 sin6from = &asoc->peer.primary_addr.v6;
 773                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 774                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 775                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 776         }
 777 }
 778
 779 /* Initialize a msg_name from an inbound skb. */
 780 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 781                                    int *addr_len)
 782 {
 783         struct sctphdr *sh;
 784         struct sockaddr_in6 *sin6;
 785
 786         if (msgname) {
 787                 sctp_inet6_msgname(msgname, addr_len);
 788                 sin6 = (struct sockaddr_in6 *)msgname;
 789                 sh = sctp_hdr(skb);
 790                 sin6->sin6_port = sh->source;
 791
 792                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 793                 if (sctp_sk(skb->sk)->v4mapped &&
 794                     ip_hdr(skb)->version == 4) {
 795                         sctp_v4_map_v6((union sctp_addr *)sin6);
 796                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 797                         return;
 798                 }
 799
 800                 /* Otherwise, just copy the v6 address. */
 801                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 802                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 803                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 804                         sin6->sin6_scope_id = ev->iif;
 805                 }
 806         }
 807 }
 808
 809 /* Do we support this AF? */
 810 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 811 {
 812         switch (family) {
 813         case AF_INET6:
 814                 return 1;
 815         /* v4-mapped-v6 addresses */
 816         case AF_INET:
 817                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 818                         return 1;
 819         default:
 820                 return 0;
 821         }
 822 }
 823
 824 /* Address matching with wildcards allowed.  This extra level
 825  * of indirection lets us choose whether a PF_INET6 should
 826  * disallow any v4 addresses if we so choose.
 827  */
 828 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 829                                const union sctp_addr *addr2,
 830                                struct sctp_sock *opt)
 831 {
 832         struct sctp_af *af1, *af2;
 833         struct sock *sk = sctp_opt2sk(opt);
 834
 835         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 836         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 837
 838         if (!af1 || !af2)
 839                 return 0;
 840
 841         /* If the socket is IPv6 only, v4 addrs will not match */
 842         if (__ipv6_only_sock(sk) && af1 != af2)
 843                 return 0;
 844
 845         /* Today, wildcard AF_INET/AF_INET6. */
 846         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 847                 return 1;
 848
 849         if (addr1->sa.sa_family != addr2->sa.sa_family)
 850                 return 0;
 851
 852         return af1->cmp_addr(addr1, addr2);
 853 }
 854
 855 /* Verify that the provided sockaddr looks bindable.   Common verification,
 856  * has already been taken care of.
 857  */
 858 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 859 {
 860         struct sctp_af *af;
 861
 862         /* ASSERT: address family has already been verified. */
 863         if (addr->sa.sa_family != AF_INET6)
 864                 af = sctp_get_af_specific(addr->sa.sa_family);
 865         else {
 866                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 867                 struct net_device *dev;
 868
 869                 if (type & IPV6_ADDR_LINKLOCAL) {
 870                         if (!addr->v6.sin6_scope_id)
 871                                 return 0;
 872                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 873                         if (!dev)
 874                                 return 0;
 875                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 876                                            dev, 0)) {
 877                                 dev_put(dev);
 878                                 return 0;
 879                         }
 880                         dev_put(dev);
 881                 } else if (type == IPV6_ADDR_MAPPED) {
 882                         if (!opt->v4mapped)
 883                                 return 0;
 884                 }
 885
 886                 af = opt->pf->af;
 887         }
 888         return af->available(addr, opt);
 889 }
 890
 891 /* Verify that the provided sockaddr looks sendable.   Common verification,
 892  * has already been taken care of.
 893  */
 894 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 895 {
 896         struct sctp_af *af = NULL;
 897
 898         /* ASSERT: address family has already been verified. */
 899         if (addr->sa.sa_family != AF_INET6)
 900                 af = sctp_get_af_specific(addr->sa.sa_family);
 901         else {
 902                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 903                 struct net_device *dev;
 904
 905                 if (type & IPV6_ADDR_LINKLOCAL) {
 906                         if (!addr->v6.sin6_scope_id)
 907                                 return 0;
 908                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 909                         if (!dev)
 910                                 return 0;
 911                         dev_put(dev);
 912                 }
 913                 af = opt->pf->af;
 914         }
 915
 916         return af != NULL;
 917 }
 918
 919 /* Fill in Supported Address Type information for INIT and INIT-ACK
 920  * chunks.   Note: In the future, we may want to look at sock options
 921  * to determine whether a PF_INET6 socket really wants to have IPV4
 922  * addresses.
 923  * Returns number of addresses supported.
 924  */
 925 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 926                                       __be16 *types)
 927 {
 928         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 929         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 930                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 931                 return 2;
 932         }
 933         return 1;
 934 }
 935
 936 static const struct proto_ops inet6_seqpacket_ops = {
 937         .family            = PF_INET6,
 938         .owner             = THIS_MODULE,
 939         .release           = inet6_release,
 940         .bind              = inet6_bind,
 941         .connect           = inet_dgram_connect,
 942         .socketpair        = sock_no_socketpair,
 943         .accept            = inet_accept,
 944         .getname           = inet6_getname,
 945         .poll              = sctp_poll,
 946         .ioctl             = inet6_ioctl,
 947         .listen            = sctp_inet_listen,
 948         .shutdown          = inet_shutdown,
 949         .setsockopt        = sock_common_setsockopt,
 950         .getsockopt        = sock_common_getsockopt,
 951         .sendmsg           = inet_sendmsg,
 952         .recvmsg           = sock_common_recvmsg,
 953         .mmap              = sock_no_mmap,
 954 #ifdef CONFIG_COMPAT
 955         .compat_setsockopt = compat_sock_common_setsockopt,
 956         .compat_getsockopt = compat_sock_common_getsockopt,
 957 #endif
 958 };
 959
 960 static struct inet_protosw sctpv6_seqpacket_protosw = {
 961         .type          = SOCK_SEQPACKET,
 962         .protocol      = IPPROTO_SCTP,
 963         .prot          = &sctpv6_prot,
 964         .ops           = &inet6_seqpacket_ops,
 965         .capability    = -1,
 966         .no_check      = 0,
 967         .flags         = SCTP_PROTOSW_FLAG
 968 };
 969 static struct inet_protosw sctpv6_stream_protosw = {
 970         .type          = SOCK_STREAM,
 971         .protocol      = IPPROTO_SCTP,
 972         .prot          = &sctpv6_prot,
 973         .ops           = &inet6_seqpacket_ops,
 974         .capability    = -1,
 975         .no_check      = 0,
 976         .flags         = SCTP_PROTOSW_FLAG,
 977 };
 978
 979 static int sctp6_rcv(struct sk_buff *skb)
 980 {
 981         return sctp_rcv(skb) ? -1 : 0;
 982 }
 983
 984 static struct inet6_protocol sctpv6_protocol = {
 985         .handler      = sctp6_rcv,
 986         .err_handler  = sctp_v6_err,
 987         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 988 };
 989
 990 static struct sctp_af sctp_af_inet6 = {
 991         .sa_family         = AF_INET6,
 992         .sctp_xmit         = sctp_v6_xmit,
 993         .setsockopt        = ipv6_setsockopt,
 994         .getsockopt        = ipv6_getsockopt,
 995         .get_dst           = sctp_v6_get_dst,
 996         .get_saddr         = sctp_v6_get_saddr,
 997         .copy_addrlist     = sctp_v6_copy_addrlist,
 998         .from_skb          = sctp_v6_from_skb,
 999         .from_sk           = sctp_v6_from_sk,
1000         .to_sk_saddr       = sctp_v6_to_sk_saddr,
1001         .to_sk_daddr       = sctp_v6_to_sk_daddr,
1002         .from_addr_param   = sctp_v6_from_addr_param,
1003         .to_addr_param     = sctp_v6_to_addr_param,
1004         .dst_saddr         = sctp_v6_dst_saddr,
1005         .cmp_addr          = sctp_v6_cmp_addr,
1006         .scope             = sctp_v6_scope,
1007         .addr_valid        = sctp_v6_addr_valid,
1008         .inaddr_any        = sctp_v6_inaddr_any,
1009         .is_any            = sctp_v6_is_any,
1010         .available         = sctp_v6_available,
1011         .skb_iif           = sctp_v6_skb_iif,
1012         .is_ce             = sctp_v6_is_ce,
1013         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1014         .ecn_capable       = sctp_v6_ecn_capable,
1015         .net_header_len    = sizeof(struct ipv6hdr),
1016         .sockaddr_len      = sizeof(struct sockaddr_in6),
1017 #ifdef CONFIG_COMPAT
1018         .compat_setsockopt = compat_ipv6_setsockopt,
1019         .compat_getsockopt = compat_ipv6_getsockopt,
1020 #endif
1021 };
1022
1023 static struct sctp_pf sctp_pf_inet6 = {
1024         .event_msgname = sctp_inet6_event_msgname,
1025         .skb_msgname   = sctp_inet6_skb_msgname,
1026         .af_supported  = sctp_inet6_af_supported,
1027         .cmp_addr      = sctp_inet6_cmp_addr,
1028         .bind_verify   = sctp_inet6_bind_verify,
1029         .send_verify   = sctp_inet6_send_verify,
1030         .supported_addrs = sctp_inet6_supported_addrs,
1031         .create_accept_sk = sctp_v6_create_accept_sk,
1032         .addr_v4map    = sctp_v6_addr_v4map,
1033         .af            = &sctp_af_inet6,
1034 };
1035
1036 /* Initialize IPv6 support and register with socket layer.  */
1037 void sctp_v6_pf_init(void)
1038 {
1039         /* Register the SCTP specific PF_INET6 functions. */
1040         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1041
1042         /* Register the SCTP specific AF_INET6 functions. */
1043         sctp_register_af(&sctp_af_inet6);
1044 }
1045
1046 void sctp_v6_pf_exit(void)
1047 {
1048         list_del(&sctp_af_inet6.list);
1049 }
1050
1051 /* Initialize IPv6 support and register with socket layer.  */
1052 int sctp_v6_protosw_init(void)
1053 {
1054         int rc;
1055
1056         rc = proto_register(&sctpv6_prot, 1);
1057         if (rc)
1058                 return rc;
1059
1060         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1061         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1062         inet6_register_protosw(&sctpv6_stream_protosw);
1063
1064         return 0;
1065 }
1066
1067 void sctp_v6_protosw_exit(void)
1068 {
1069         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1070         inet6_unregister_protosw(&sctpv6_stream_protosw);
1071         proto_unregister(&sctpv6_prot);
1072 }
1073
1074
1075 /* Register with inet6 layer. */
1076 int sctp_v6_add_protocol(void)
1077 {
1078         /* Register notifier for inet6 address additions/deletions. */
1079         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1080
1081         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1082                 return -EAGAIN;
1083
1084         return 0;
1085 }
1086
1087 /* Unregister with inet6 layer. */
1088 void sctp_v6_del_protocol(void)
1089 {
1090         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1091         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1092 }