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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                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifa->addr);
 101                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 102                         addr->valid = 1;
 103                         spin_lock_bh(&sctp_local_addr_lock);
 104                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
 105                         spin_unlock_bh(&sctp_local_addr_lock);
 106                 }
 107                 break;
 108         case NETDEV_DOWN:
 109                 spin_lock_bh(&sctp_local_addr_lock);
 110                 list_for_each_entry_safe(addr, temp,
 111                                         &sctp_local_addr_list, list) {
 112                         if (addr->a.sa.sa_family == AF_INET6 &&
 113                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
 114                                                 &ifa->addr)) {
 115                                 found = 1;
 116                                 addr->valid = 0;
 117                                 list_del_rcu(&addr->list);
 118                                 break;
 119                         }
 120                 }
 121                 spin_unlock_bh(&sctp_local_addr_lock);
 122                 if (found)
 123                         call_rcu(&addr->rcu, sctp_local_addr_free);
 124                 break;
 125         }
 126
 127         return NOTIFY_DONE;
 128 }
 129
 130 static struct notifier_block sctp_inet6addr_notifier = {
 131         .notifier_call = sctp_inet6addr_event,
 132 };
 133
 134 /* ICMP error handler. */
 135 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 136                              u8 type, u8 code, int offset, __be32 info)
 137 {
 138         struct inet6_dev *idev;
 139         struct sock *sk;
 140         struct sctp_association *asoc;
 141         struct sctp_transport *transport;
 142         struct ipv6_pinfo *np;
 143         sk_buff_data_t saveip, savesctp;
 144         int err;
 145
 146         idev = in6_dev_get(skb->dev);
 147
 148         /* Fix up skb to look at the embedded net header. */
 149         saveip   = skb->network_header;
 150         savesctp = skb->transport_header;
 151         skb_reset_network_header(skb);
 152         skb_set_transport_header(skb, offset);
 153         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 154         /* Put back, the original pointers. */
 155         skb->network_header   = saveip;
 156         skb->transport_header = savesctp;
 157         if (!sk) {
 158                 ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
 159                 goto out;
 160         }
 161
 162         /* Warning:  The sock lock is held.  Remember to call
 163          * sctp_err_finish!
 164          */
 165
 166         switch (type) {
 167         case ICMPV6_PKT_TOOBIG:
 168                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 169                 goto out_unlock;
 170         case ICMPV6_PARAMPROB:
 171                 if (ICMPV6_UNK_NEXTHDR == code) {
 172                         sctp_icmp_proto_unreachable(sk, asoc, transport);
 173                         goto out_unlock;
 174                 }
 175                 break;
 176         default:
 177                 break;
 178         }
 179
 180         np = inet6_sk(sk);
 181         icmpv6_err_convert(type, code, &err);
 182         if (!sock_owned_by_user(sk) && np->recverr) {
 183                 sk->sk_err = err;
 184                 sk->sk_error_report(sk);
 185         } else {  /* Only an error on timeout */
 186                 sk->sk_err_soft = err;
 187         }
 188
 189 out_unlock:
 190         sctp_err_finish(sk, asoc);
 191 out:
 192         if (likely(idev != NULL))
 193                 in6_dev_put(idev);
 194 }
 195
 196 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 197 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 198 {
 199         struct sock *sk = skb->sk;
 200         struct ipv6_pinfo *np = inet6_sk(sk);
 201         struct flowi fl;
 202
 203         memset(&fl, 0, sizeof(fl));
 204
 205         fl.proto = sk->sk_protocol;
 206
 207         /* Fill in the dest address from the route entry passed with the skb
 208          * and the source address from the transport.
 209          */
 210         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 211         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 212
 213         fl.fl6_flowlabel = np->flow_label;
 214         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 215         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 216                 fl.oif = transport->saddr.v6.sin6_scope_id;
 217         else
 218                 fl.oif = sk->sk_bound_dev_if;
 219
 220         if (np->opt && np->opt->srcrt) {
 221                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 222                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 223         }
 224
 225         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 226                           __func__, skb, skb->len,
 227                           &fl.fl6_src, &fl.fl6_dst);
 228
 229         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 230
 231         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 232                 skb->local_df = 1;
 233
 234         return ip6_xmit(sk, skb, &fl, np->opt, 0);
 235 }
 236
 237 /* Returns the dst cache entry for the given source and destination ip
 238  * addresses.
 239  */
 240 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 241                                          union sctp_addr *daddr,
 242                                          union sctp_addr *saddr)
 243 {
 244         struct dst_entry *dst;
 245         struct flowi fl;
 246
 247         memset(&fl, 0, sizeof(fl));
 248         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 249         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 250                 fl.oif = daddr->v6.sin6_scope_id;
 251
 252
 253         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl.fl6_dst);
 254
 255         if (saddr) {
 256                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 257                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl.fl6_src);
 258         }
 259
 260         dst = ip6_route_output(&init_net, NULL, &fl);
 261         if (!dst->error) {
 262                 struct rt6_info *rt;
 263                 rt = (struct rt6_info *)dst;
 264                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 265                         &rt->rt6i_dst.addr, &rt->rt6i_src.addr);
 266                 return dst;
 267         }
 268         SCTP_DEBUG_PRINTK("NO ROUTE\n");
 269         dst_release(dst);
 270         return NULL;
 271 }
 272
 273 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 274  * addresses.
 275  */
 276 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 277                                          union sctp_addr *s2)
 278 {
 279         struct in6_addr *a1 = &s1->v6.sin6_addr;
 280         struct in6_addr *a2 = &s2->v6.sin6_addr;
 281         int i, j;
 282
 283         for (i = 0; i < 4 ; i++) {
 284                 __be32 a1xora2;
 285
 286                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 287
 288                 if ((j = fls(ntohl(a1xora2))))
 289                         return (i * 32 + 32 - j);
 290         }
 291
 292         return (i*32);
 293 }
 294
 295 /* Fills in the source address(saddr) based on the destination address(daddr)
 296  * and asoc's bind address list.
 297  */
 298 static void sctp_v6_get_saddr(struct sctp_sock *sk,
 299                               struct sctp_association *asoc,
 300                               struct dst_entry *dst,
 301                               union sctp_addr *daddr,
 302                               union sctp_addr *saddr)
 303 {
 304         struct sctp_bind_addr *bp;
 305         struct sctp_sockaddr_entry *laddr;
 306         sctp_scope_t scope;
 307         union sctp_addr *baddr = NULL;
 308         __u8 matchlen = 0;
 309         __u8 bmatchlen;
 310
 311         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p daddr:%pI6 ",
 312                           __func__, asoc, dst, &daddr->v6.sin6_addr);
 313
 314         if (!asoc) {
 315                 ipv6_dev_get_saddr(sock_net(sctp_opt2sk(sk)),
 316                                    dst ? ip6_dst_idev(dst)->dev : NULL,
 317                                    &daddr->v6.sin6_addr,
 318                                    inet6_sk(&sk->inet.sk)->srcprefs,
 319                                    &saddr->v6.sin6_addr);
 320                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: %pI6\n",
 321                                   &saddr->v6.sin6_addr);
 322                 return;
 323         }
 324
 325         scope = sctp_scope(daddr);
 326
 327         bp = &asoc->base.bind_addr;
 328
 329         /* Go through the bind address list and find the best source address
 330          * that matches the scope of the destination address.
 331          */
 332         rcu_read_lock();
 333         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 334                 if (!laddr->valid)
 335                         continue;
 336                 if ((laddr->state == SCTP_ADDR_SRC) &&
 337                     (laddr->a.sa.sa_family == AF_INET6) &&
 338                     (scope <= sctp_scope(&laddr->a))) {
 339                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 340                         if (!baddr || (matchlen < bmatchlen)) {
 341                                 baddr = &laddr->a;
 342                                 matchlen = bmatchlen;
 343                         }
 344                 }
 345         }
 346
 347         if (baddr) {
 348                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 349                 SCTP_DEBUG_PRINTK("saddr: %pI6\n", &saddr->v6.sin6_addr);
 350         } else {
 351                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 352                        "address for the dest:%pI6\n",
 353                        __func__, asoc, &daddr->v6.sin6_addr);
 354         }
 355
 356         rcu_read_unlock();
 357 }
 358
 359 /* Make a copy of all potential local addresses. */
 360 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 361                                   struct net_device *dev)
 362 {
 363         struct inet6_dev *in6_dev;
 364         struct inet6_ifaddr *ifp;
 365         struct sctp_sockaddr_entry *addr;
 366
 367         rcu_read_lock();
 368         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 369                 rcu_read_unlock();
 370                 return;
 371         }
 372
 373         read_lock_bh(&in6_dev->lock);
 374         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 375                 /* Add the address to the local list.  */
 376                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 377                 if (addr) {
 378                         addr->a.v6.sin6_family = AF_INET6;
 379                         addr->a.v6.sin6_port = 0;
 380                         addr->a.v6.sin6_addr = ifp->addr;
 381                         addr->a.v6.sin6_scope_id = dev->ifindex;
 382                         addr->valid = 1;
 383                         INIT_LIST_HEAD(&addr->list);
 384                         INIT_RCU_HEAD(&addr->rcu);
 385                         list_add_tail(&addr->list, addrlist);
 386                 }
 387         }
 388
 389         read_unlock_bh(&in6_dev->lock);
 390         rcu_read_unlock();
 391 }
 392
 393 /* Initialize a sockaddr_storage from in incoming skb. */
 394 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 395                              int is_saddr)
 396 {
 397         void *from;
 398         __be16 *port;
 399         struct sctphdr *sh;
 400
 401         port = &addr->v6.sin6_port;
 402         addr->v6.sin6_family = AF_INET6;
 403         addr->v6.sin6_flowinfo = 0; /* FIXME */
 404         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 405
 406         sh = sctp_hdr(skb);
 407         if (is_saddr) {
 408                 *port  = sh->source;
 409                 from = &ipv6_hdr(skb)->saddr;
 410         } else {
 411                 *port = sh->dest;
 412                 from = &ipv6_hdr(skb)->daddr;
 413         }
 414         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 415 }
 416
 417 /* Initialize an sctp_addr from a socket. */
 418 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 419 {
 420         addr->v6.sin6_family = AF_INET6;
 421         addr->v6.sin6_port = 0;
 422         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 423 }
 424
 425 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 426 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 427 {
 428         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 429                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 430                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 431                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 432                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 433                         addr->v4.sin_addr.s_addr;
 434         } else {
 435                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 436         }
 437 }
 438
 439 /* Initialize sk->sk_daddr from sctp_addr. */
 440 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 441 {
 442         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 443                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 444                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 445                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 446                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 447         } else {
 448                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 449         }
 450 }
 451
 452 /* Initialize a sctp_addr from an address parameter. */
 453 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 454                                     union sctp_addr_param *param,
 455                                     __be16 port, int iif)
 456 {
 457         addr->v6.sin6_family = AF_INET6;
 458         addr->v6.sin6_port = port;
 459         addr->v6.sin6_flowinfo = 0; /* BUG */
 460         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 461         addr->v6.sin6_scope_id = iif;
 462 }
 463
 464 /* Initialize an address parameter from a sctp_addr and return the length
 465  * of the address parameter.
 466  */
 467 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 468                                  union sctp_addr_param *param)
 469 {
 470         int length = sizeof(sctp_ipv6addr_param_t);
 471
 472         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 473         param->v6.param_hdr.length = htons(length);
 474         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 475
 476         return length;
 477 }
 478
 479 /* Initialize a sctp_addr from a dst_entry. */
 480 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 481                               __be16 port)
 482 {
 483         struct rt6_info *rt = (struct rt6_info *)dst;
 484         addr->sa.sa_family = AF_INET6;
 485         addr->v6.sin6_port = port;
 486         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 487 }
 488
 489 /* Compare addresses exactly.
 490  * v4-mapped-v6 is also in consideration.
 491  */
 492 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 493                             const union sctp_addr *addr2)
 494 {
 495         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 496                 if (addr1->sa.sa_family == AF_INET &&
 497                     addr2->sa.sa_family == AF_INET6 &&
 498                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 499                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 500                             addr2->v6.sin6_addr.s6_addr32[3] ==
 501                             addr1->v4.sin_addr.s_addr)
 502                                 return 1;
 503                 }
 504                 if (addr2->sa.sa_family == AF_INET &&
 505                     addr1->sa.sa_family == AF_INET6 &&
 506                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 507                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 508                             addr1->v6.sin6_addr.s6_addr32[3] ==
 509                             addr2->v4.sin_addr.s_addr)
 510                                 return 1;
 511                 }
 512                 return 0;
 513         }
 514         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 515                 return 0;
 516         /* If this is a linklocal address, compare the scope_id. */
 517         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 518                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 519                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 520                         return 0;
 521                 }
 522         }
 523
 524         return 1;
 525 }
 526
 527 /* Initialize addr struct to INADDR_ANY. */
 528 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 529 {
 530         memset(addr, 0x00, sizeof(union sctp_addr));
 531         addr->v6.sin6_family = AF_INET6;
 532         addr->v6.sin6_port = port;
 533 }
 534
 535 /* Is this a wildcard address? */
 536 static int sctp_v6_is_any(const union sctp_addr *addr)
 537 {
 538         return ipv6_addr_any(&addr->v6.sin6_addr);
 539 }
 540
 541 /* Should this be available for binding?   */
 542 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 543 {
 544         int type;
 545         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 546
 547         type = ipv6_addr_type(in6);
 548         if (IPV6_ADDR_ANY == type)
 549                 return 1;
 550         if (type == IPV6_ADDR_MAPPED) {
 551                 if (sp && !sp->v4mapped)
 552                         return 0;
 553                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 554                         return 0;
 555                 sctp_v6_map_v4(addr);
 556                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 557         }
 558         if (!(type & IPV6_ADDR_UNICAST))
 559                 return 0;
 560
 561         return ipv6_chk_addr(&init_net, in6, NULL, 0);
 562 }
 563
 564 /* This function checks if the address is a valid address to be used for
 565  * SCTP.
 566  *
 567  * Output:
 568  * Return 0 - If the address is a non-unicast or an illegal address.
 569  * Return 1 - If the address is a unicast.
 570  */
 571 static int sctp_v6_addr_valid(union sctp_addr *addr,
 572                               struct sctp_sock *sp,
 573                               const struct sk_buff *skb)
 574 {
 575         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 576
 577         /* Support v4-mapped-v6 address. */
 578         if (ret == IPV6_ADDR_MAPPED) {
 579                 /* Note: This routine is used in input, so v4-mapped-v6
 580                  * are disallowed here when there is no sctp_sock.
 581                  */
 582                 if (!sp || !sp->v4mapped)
 583                         return 0;
 584                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 585                         return 0;
 586                 sctp_v6_map_v4(addr);
 587                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 588         }
 589
 590         /* Is this a non-unicast address */
 591         if (!(ret & IPV6_ADDR_UNICAST))
 592                 return 0;
 593
 594         return 1;
 595 }
 596
 597 /* What is the scope of 'addr'?  */
 598 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 599 {
 600         int v6scope;
 601         sctp_scope_t retval;
 602
 603         /* The IPv6 scope is really a set of bit fields.
 604          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 605          */
 606
 607         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 608         switch (v6scope) {
 609         case IFA_HOST:
 610                 retval = SCTP_SCOPE_LOOPBACK;
 611                 break;
 612         case IFA_LINK:
 613                 retval = SCTP_SCOPE_LINK;
 614                 break;
 615         case IFA_SITE:
 616                 retval = SCTP_SCOPE_PRIVATE;
 617                 break;
 618         default:
 619                 retval = SCTP_SCOPE_GLOBAL;
 620                 break;
 621         }
 622
 623         return retval;
 624 }
 625
 626 /* Create and initialize a new sk for the socket to be returned by accept(). */
 627 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 628                                              struct sctp_association *asoc)
 629 {
 630         struct sock *newsk;
 631         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 632         struct sctp6_sock *newsctp6sk;
 633
 634         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 635         if (!newsk)
 636                 goto out;
 637
 638         sock_init_data(NULL, newsk);
 639
 640         sctp_copy_sock(newsk, sk, asoc);
 641         sock_reset_flag(sk, SOCK_ZAPPED);
 642
 643         newsctp6sk = (struct sctp6_sock *)newsk;
 644         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 645
 646         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 647
 648         newnp = inet6_sk(newsk);
 649
 650         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 651
 652         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 653          * and getpeername().
 654          */
 655         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 656
 657         sk_refcnt_debug_inc(newsk);
 658
 659         if (newsk->sk_prot->init(newsk)) {
 660                 sk_common_release(newsk);
 661                 newsk = NULL;
 662         }
 663
 664 out:
 665         return newsk;
 666 }
 667
 668 /* Map v4 address to mapped v6 address */
 669 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 670 {
 671         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 672                 sctp_v4_map_v6(addr);
 673 }
 674
 675 /* Where did this skb come from?  */
 676 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 677 {
 678         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 679         return opt->iif;
 680 }
 681
 682 /* Was this packet marked by Explicit Congestion Notification? */
 683 static int sctp_v6_is_ce(const struct sk_buff *skb)
 684 {
 685         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 686 }
 687
 688 /* Dump the v6 addr to the seq file. */
 689 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 690 {
 691         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 692 }
 693
 694 static void sctp_v6_ecn_capable(struct sock *sk)
 695 {
 696         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 697 }
 698
 699 /* Initialize a PF_INET6 socket msg_name. */
 700 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 701 {
 702         struct sockaddr_in6 *sin6;
 703
 704         sin6 = (struct sockaddr_in6 *)msgname;
 705         sin6->sin6_family = AF_INET6;
 706         sin6->sin6_flowinfo = 0;
 707         sin6->sin6_scope_id = 0; /*FIXME */
 708         *addr_len = sizeof(struct sockaddr_in6);
 709 }
 710
 711 /* Initialize a PF_INET msgname from a ulpevent. */
 712 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 713                                      char *msgname, int *addrlen)
 714 {
 715         struct sockaddr_in6 *sin6, *sin6from;
 716
 717         if (msgname) {
 718                 union sctp_addr *addr;
 719                 struct sctp_association *asoc;
 720
 721                 asoc = event->asoc;
 722                 sctp_inet6_msgname(msgname, addrlen);
 723                 sin6 = (struct sockaddr_in6 *)msgname;
 724                 sin6->sin6_port = htons(asoc->peer.port);
 725                 addr = &asoc->peer.primary_addr;
 726
 727                 /* Note: If we go to a common v6 format, this code
 728                  * will change.
 729                  */
 730
 731                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 732                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 733                     AF_INET == addr->sa.sa_family) {
 734                         sctp_v4_map_v6((union sctp_addr *)sin6);
 735                         sin6->sin6_addr.s6_addr32[3] =
 736                                 addr->v4.sin_addr.s_addr;
 737                         return;
 738                 }
 739
 740                 sin6from = &asoc->peer.primary_addr.v6;
 741                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 742                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 743                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 744         }
 745 }
 746
 747 /* Initialize a msg_name from an inbound skb. */
 748 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 749                                    int *addr_len)
 750 {
 751         struct sctphdr *sh;
 752         struct sockaddr_in6 *sin6;
 753
 754         if (msgname) {
 755                 sctp_inet6_msgname(msgname, addr_len);
 756                 sin6 = (struct sockaddr_in6 *)msgname;
 757                 sh = sctp_hdr(skb);
 758                 sin6->sin6_port = sh->source;
 759
 760                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 761                 if (sctp_sk(skb->sk)->v4mapped &&
 762                     ip_hdr(skb)->version == 4) {
 763                         sctp_v4_map_v6((union sctp_addr *)sin6);
 764                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 765                         return;
 766                 }
 767
 768                 /* Otherwise, just copy the v6 address. */
 769                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 770                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 771                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 772                         sin6->sin6_scope_id = ev->iif;
 773                 }
 774         }
 775 }
 776
 777 /* Do we support this AF? */
 778 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 779 {
 780         switch (family) {
 781         case AF_INET6:
 782                 return 1;
 783         /* v4-mapped-v6 addresses */
 784         case AF_INET:
 785                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 786                         return 1;
 787         default:
 788                 return 0;
 789         }
 790 }
 791
 792 /* Address matching with wildcards allowed.  This extra level
 793  * of indirection lets us choose whether a PF_INET6 should
 794  * disallow any v4 addresses if we so choose.
 795  */
 796 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 797                                const union sctp_addr *addr2,
 798                                struct sctp_sock *opt)
 799 {
 800         struct sctp_af *af1, *af2;
 801         struct sock *sk = sctp_opt2sk(opt);
 802
 803         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 804         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 805
 806         if (!af1 || !af2)
 807                 return 0;
 808
 809         /* If the socket is IPv6 only, v4 addrs will not match */
 810         if (__ipv6_only_sock(sk) && af1 != af2)
 811                 return 0;
 812
 813         /* Today, wildcard AF_INET/AF_INET6. */
 814         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 815                 return 1;
 816
 817         if (addr1->sa.sa_family != addr2->sa.sa_family)
 818                 return 0;
 819
 820         return af1->cmp_addr(addr1, addr2);
 821 }
 822
 823 /* Verify that the provided sockaddr looks bindable.   Common verification,
 824  * has already been taken care of.
 825  */
 826 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 827 {
 828         struct sctp_af *af;
 829
 830         /* ASSERT: address family has already been verified. */
 831         if (addr->sa.sa_family != AF_INET6)
 832                 af = sctp_get_af_specific(addr->sa.sa_family);
 833         else {
 834                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 835                 struct net_device *dev;
 836
 837                 if (type & IPV6_ADDR_LINKLOCAL) {
 838                         if (!addr->v6.sin6_scope_id)
 839                                 return 0;
 840                         rcu_read_lock();
 841                         dev = dev_get_by_index_rcu(&init_net,
 842                                                    addr->v6.sin6_scope_id);
 843                         if (!dev ||
 844                             !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 845                                            dev, 0)) {
 846                                 rcu_read_unlock();
 847                                 return 0;
 848                         }
 849                         rcu_read_unlock();
 850                 } else if (type == IPV6_ADDR_MAPPED) {
 851                         if (!opt->v4mapped)
 852                                 return 0;
 853                 }
 854
 855                 af = opt->pf->af;
 856         }
 857         return af->available(addr, opt);
 858 }
 859
 860 /* Verify that the provided sockaddr looks sendable.   Common verification,
 861  * has already been taken care of.
 862  */
 863 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 864 {
 865         struct sctp_af *af = NULL;
 866
 867         /* ASSERT: address family has already been verified. */
 868         if (addr->sa.sa_family != AF_INET6)
 869                 af = sctp_get_af_specific(addr->sa.sa_family);
 870         else {
 871                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 872                 struct net_device *dev;
 873
 874                 if (type & IPV6_ADDR_LINKLOCAL) {
 875                         if (!addr->v6.sin6_scope_id)
 876                                 return 0;
 877                         rcu_read_lock();
 878                         dev = dev_get_by_index_rcu(&init_net,
 879                                                    addr->v6.sin6_scope_id);
 880                         rcu_read_unlock();
 881                         if (!dev)
 882                                 return 0;
 883                 }
 884                 af = opt->pf->af;
 885         }
 886
 887         return af != NULL;
 888 }
 889
 890 /* Fill in Supported Address Type information for INIT and INIT-ACK
 891  * chunks.   Note: In the future, we may want to look at sock options
 892  * to determine whether a PF_INET6 socket really wants to have IPV4
 893  * addresses.
 894  * Returns number of addresses supported.
 895  */
 896 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 897                                       __be16 *types)
 898 {
 899         types[0] = SCTP_PARAM_IPV6_ADDRESS;
 900         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 901                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
 902                 return 2;
 903         }
 904         return 1;
 905 }
 906
 907 static const struct proto_ops inet6_seqpacket_ops = {
 908         .family            = PF_INET6,
 909         .owner             = THIS_MODULE,
 910         .release           = inet6_release,
 911         .bind              = inet6_bind,
 912         .connect           = inet_dgram_connect,
 913         .socketpair        = sock_no_socketpair,
 914         .accept            = inet_accept,
 915         .getname           = inet6_getname,
 916         .poll              = sctp_poll,
 917         .ioctl             = inet6_ioctl,
 918         .listen            = sctp_inet_listen,
 919         .shutdown          = inet_shutdown,
 920         .setsockopt        = sock_common_setsockopt,
 921         .getsockopt        = sock_common_getsockopt,
 922         .sendmsg           = inet_sendmsg,
 923         .recvmsg           = sock_common_recvmsg,
 924         .mmap              = sock_no_mmap,
 925 #ifdef CONFIG_COMPAT
 926         .compat_setsockopt = compat_sock_common_setsockopt,
 927         .compat_getsockopt = compat_sock_common_getsockopt,
 928 #endif
 929 };
 930
 931 static struct inet_protosw sctpv6_seqpacket_protosw = {
 932         .type          = SOCK_SEQPACKET,
 933         .protocol      = IPPROTO_SCTP,
 934         .prot          = &sctpv6_prot,
 935         .ops           = &inet6_seqpacket_ops,
 936         .no_check      = 0,
 937         .flags         = SCTP_PROTOSW_FLAG
 938 };
 939 static struct inet_protosw sctpv6_stream_protosw = {
 940         .type          = SOCK_STREAM,
 941         .protocol      = IPPROTO_SCTP,
 942         .prot          = &sctpv6_prot,
 943         .ops           = &inet6_seqpacket_ops,
 944         .no_check      = 0,
 945         .flags         = SCTP_PROTOSW_FLAG,
 946 };
 947
 948 static int sctp6_rcv(struct sk_buff *skb)
 949 {
 950         return sctp_rcv(skb) ? -1 : 0;
 951 }
 952
 953 static const struct inet6_protocol sctpv6_protocol = {
 954         .handler      = sctp6_rcv,
 955         .err_handler  = sctp_v6_err,
 956         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 957 };
 958
 959 static struct sctp_af sctp_af_inet6 = {
 960         .sa_family         = AF_INET6,
 961         .sctp_xmit         = sctp_v6_xmit,
 962         .setsockopt        = ipv6_setsockopt,
 963         .getsockopt        = ipv6_getsockopt,
 964         .get_dst           = sctp_v6_get_dst,
 965         .get_saddr         = sctp_v6_get_saddr,
 966         .copy_addrlist     = sctp_v6_copy_addrlist,
 967         .from_skb          = sctp_v6_from_skb,
 968         .from_sk           = sctp_v6_from_sk,
 969         .to_sk_saddr       = sctp_v6_to_sk_saddr,
 970         .to_sk_daddr       = sctp_v6_to_sk_daddr,
 971         .from_addr_param   = sctp_v6_from_addr_param,
 972         .to_addr_param     = sctp_v6_to_addr_param,
 973         .dst_saddr         = sctp_v6_dst_saddr,
 974         .cmp_addr          = sctp_v6_cmp_addr,
 975         .scope             = sctp_v6_scope,
 976         .addr_valid        = sctp_v6_addr_valid,
 977         .inaddr_any        = sctp_v6_inaddr_any,
 978         .is_any            = sctp_v6_is_any,
 979         .available         = sctp_v6_available,
 980         .skb_iif           = sctp_v6_skb_iif,
 981         .is_ce             = sctp_v6_is_ce,
 982         .seq_dump_addr     = sctp_v6_seq_dump_addr,
 983         .ecn_capable       = sctp_v6_ecn_capable,
 984         .net_header_len    = sizeof(struct ipv6hdr),
 985         .sockaddr_len      = sizeof(struct sockaddr_in6),
 986 #ifdef CONFIG_COMPAT
 987         .compat_setsockopt = compat_ipv6_setsockopt,
 988         .compat_getsockopt = compat_ipv6_getsockopt,
 989 #endif
 990 };
 991
 992 static struct sctp_pf sctp_pf_inet6 = {
 993         .event_msgname = sctp_inet6_event_msgname,
 994         .skb_msgname   = sctp_inet6_skb_msgname,
 995         .af_supported  = sctp_inet6_af_supported,
 996         .cmp_addr      = sctp_inet6_cmp_addr,
 997         .bind_verify   = sctp_inet6_bind_verify,
 998         .send_verify   = sctp_inet6_send_verify,
 999         .supported_addrs = sctp_inet6_supported_addrs,
1000         .create_accept_sk = sctp_v6_create_accept_sk,
1001         .addr_v4map    = sctp_v6_addr_v4map,
1002         .af            = &sctp_af_inet6,
1003 };
1004
1005 /* Initialize IPv6 support and register with socket layer.  */
1006 void sctp_v6_pf_init(void)
1007 {
1008         /* Register the SCTP specific PF_INET6 functions. */
1009         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1010
1011         /* Register the SCTP specific AF_INET6 functions. */
1012         sctp_register_af(&sctp_af_inet6);
1013 }
1014
1015 void sctp_v6_pf_exit(void)
1016 {
1017         list_del(&sctp_af_inet6.list);
1018 }
1019
1020 /* Initialize IPv6 support and register with socket layer.  */
1021 int sctp_v6_protosw_init(void)
1022 {
1023         int rc;
1024
1025         rc = proto_register(&sctpv6_prot, 1);
1026         if (rc)
1027                 return rc;
1028
1029         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1030         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1031         inet6_register_protosw(&sctpv6_stream_protosw);
1032
1033         return 0;
1034 }
1035
1036 void sctp_v6_protosw_exit(void)
1037 {
1038         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1039         inet6_unregister_protosw(&sctpv6_stream_protosw);
1040         proto_unregister(&sctpv6_prot);
1041 }
1042
1043
1044 /* Register with inet6 layer. */
1045 int sctp_v6_add_protocol(void)
1046 {
1047         /* Register notifier for inet6 address additions/deletions. */
1048         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1049
1050         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1051                 return -EAGAIN;
1052
1053         return 0;
1054 }
1055
1056 /* Unregister with inet6 layer. */
1057 void sctp_v6_del_protocol(void)
1058 {
1059         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1060         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1061 }