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   1 /* SCTP kernel reference 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 reference Implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * The SCTP reference 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  * The SCTP reference 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/sched.h>
  57 #include <linux/in.h>
  58 #include <linux/in6.h>
  59 #include <linux/netdevice.h>
  60 #include <linux/init.h>
  61 #include <linux/ipsec.h>
  62
  63 #include <linux/ipv6.h>
  64 #include <linux/icmpv6.h>
  65 #include <linux/random.h>
  66 #include <linux/seq_file.h>
  67
  68 #include <net/protocol.h>
  69 #include <net/tcp.h>
  70 #include <net/ndisc.h>
  71 #include <net/ipv6.h>
  72 #include <net/transp_v6.h>
  73 #include <net/addrconf.h>
  74 #include <net/ip6_route.h>
  75 #include <net/inet_common.h>
  76 #include <net/inet_ecn.h>
  77 #include <net/sctp/sctp.h>
  78
  79 #include <asm/uaccess.h>
  80
  81 extern int sctp_inetaddr_event(struct notifier_block *, unsigned long, void *);
  82 static struct notifier_block sctp_inet6addr_notifier = {
  83         .notifier_call = sctp_inetaddr_event,
  84 };
  85
  86 /* ICMP error handler. */
  87 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
  88                              int type, int code, int offset, __u32 info)
  89 {
  90         struct inet6_dev *idev;
  91         struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
  92         struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
  93         struct sock *sk;
  94         struct sctp_endpoint *ep;
  95         struct sctp_association *asoc;
  96         struct sctp_transport *transport;
  97         struct ipv6_pinfo *np;
  98         char *saveip, *savesctp;
  99         int err;
 100
 101         idev = in6_dev_get(skb->dev);
 102
 103         /* Fix up skb to look at the embedded net header. */
 104         saveip = skb->nh.raw;
 105         savesctp  = skb->h.raw;
 106         skb->nh.ipv6h = iph;
 107         skb->h.raw = (char *)sh;
 108         sk = sctp_err_lookup(AF_INET6, skb, sh, &ep, &asoc, &transport);
 109         /* Put back, the original pointers. */
 110         skb->nh.raw = saveip;
 111         skb->h.raw = savesctp;
 112         if (!sk) {
 113                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 114                 goto out;
 115         }
 116
 117         /* Warning:  The sock lock is held.  Remember to call
 118          * sctp_err_finish!
 119          */
 120
 121         switch (type) {
 122         case ICMPV6_PKT_TOOBIG:
 123                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 124                 goto out_unlock;
 125         case ICMPV6_PARAMPROB:
 126                 if (ICMPV6_UNK_NEXTHDR == code) {
 127                         sctp_icmp_proto_unreachable(sk, ep, asoc, transport);
 128                         goto out_unlock;
 129                 }
 130                 break;
 131         default:
 132                 break;
 133         }
 134
 135         np = inet6_sk(sk);
 136         icmpv6_err_convert(type, code, &err);
 137         if (!sock_owned_by_user(sk) && np->recverr) {
 138                 sk->sk_err = err;
 139                 sk->sk_error_report(sk);
 140         } else {  /* Only an error on timeout */
 141                 sk->sk_err_soft = err;
 142         }
 143
 144 out_unlock:
 145         sctp_err_finish(sk, ep, asoc);
 146 out:
 147         if (likely(idev != NULL))
 148                 in6_dev_put(idev);
 149 }
 150
 151 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 152 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
 153                         int ipfragok)
 154 {
 155         struct sock *sk = skb->sk;
 156         struct ipv6_pinfo *np = inet6_sk(sk);
 157         struct flowi fl;
 158
 159         memset(&fl, 0, sizeof(fl));
 160
 161         fl.proto = sk->sk_protocol;
 162
 163         /* Fill in the dest address from the route entry passed with the skb
 164          * and the source address from the transport.
 165          */
 166         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 167         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 168
 169         fl.fl6_flowlabel = np->flow_label;
 170         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 171         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 172                 fl.oif = transport->saddr.v6.sin6_scope_id;
 173         else
 174                 fl.oif = sk->sk_bound_dev_if;
 175         fl.fl_ip_sport = inet_sk(sk)->sport;
 176         fl.fl_ip_dport = transport->ipaddr.v6.sin6_port;
 177
 178         if (np->opt && np->opt->srcrt) {
 179                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 180                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 181         }
 182
 183         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
 184                           "src:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x "
 185                           "dst:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 186                           __FUNCTION__, skb, skb->len,
 187                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
 188
 189         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 190
 191         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
 192 }
 193
 194 /* Returns the dst cache entry for the given source and destination ip
 195  * addresses.
 196  */
 197 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 198                                          union sctp_addr *daddr,
 199                                          union sctp_addr *saddr)
 200 {
 201         struct dst_entry *dst;
 202         struct flowi fl;
 203
 204         memset(&fl, 0, sizeof(fl));
 205         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 206         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 207                 fl.oif = daddr->v6.sin6_scope_id;
 208
 209
 210         SCTP_DEBUG_PRINTK("%s: DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
 211                           __FUNCTION__, NIP6(fl.fl6_dst));
 212
 213         if (saddr) {
 214                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 215                 SCTP_DEBUG_PRINTK(
 216                         "SRC=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x - ",
 217                         NIP6(fl.fl6_src));
 218         }
 219
 220         dst = ip6_route_output(NULL, &fl);
 221         if (dst) {
 222                 struct rt6_info *rt;
 223                 rt = (struct rt6_info *)dst;
 224                 SCTP_DEBUG_PRINTK(
 225                         "rt6_dst:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x "
 226                         "rt6_src:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 227                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
 228         } else {
 229                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
 230         }
 231
 232         return dst;
 233 }
 234
 235 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 236  * addresses.
 237  */
 238 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 239                                          union sctp_addr *s2)
 240 {
 241         struct in6_addr *a1 = &s1->v6.sin6_addr;
 242         struct in6_addr *a2 = &s2->v6.sin6_addr;
 243         int i, j;
 244
 245         for (i = 0; i < 4 ; i++) {
 246                 __u32 a1xora2;
 247
 248                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 249
 250                 if ((j = fls(ntohl(a1xora2))))
 251                         return (i * 32 + 32 - j);
 252         }
 253
 254         return (i*32);
 255 }
 256
 257 /* Fills in the source address(saddr) based on the destination address(daddr)
 258  * and asoc's bind address list.
 259  */
 260 static void sctp_v6_get_saddr(struct sctp_association *asoc,
 261                               struct dst_entry *dst,
 262                               union sctp_addr *daddr,
 263                               union sctp_addr *saddr)
 264 {
 265         struct sctp_bind_addr *bp;
 266         rwlock_t *addr_lock;
 267         struct sctp_sockaddr_entry *laddr;
 268         struct list_head *pos;
 269         sctp_scope_t scope;
 270         union sctp_addr *baddr = NULL;
 271         __u8 matchlen = 0;
 272         __u8 bmatchlen;
 273
 274         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
 275                           "daddr:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
 276                           __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
 277
 278         if (!asoc) {
 279                 ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
 280                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: "
 281                                   "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 282                                   NIP6(saddr->v6.sin6_addr));
 283                 return;
 284         }
 285
 286         scope = sctp_scope(daddr);
 287
 288         bp = &asoc->base.bind_addr;
 289         addr_lock = &asoc->base.addr_lock;
 290
 291         /* Go through the bind address list and find the best source address
 292          * that matches the scope of the destination address.
 293          */
 294         sctp_read_lock(addr_lock);
 295         list_for_each(pos, &bp->address_list) {
 296                 laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
 297                 if ((laddr->a.sa.sa_family == AF_INET6) &&
 298                     (scope <= sctp_scope(&laddr->a))) {
 299                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 300                         if (!baddr || (matchlen < bmatchlen)) {
 301                                 baddr = &laddr->a;
 302                                 matchlen = bmatchlen;
 303                         }
 304                 }
 305         }
 306
 307         if (baddr) {
 308                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 309                 SCTP_DEBUG_PRINTK("saddr: "
 310                                   "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 311                                   NIP6(saddr->v6.sin6_addr));
 312         } else {
 313                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 314                        "address for the "
 315                        "dest:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 316                        __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
 317         }
 318
 319         sctp_read_unlock(addr_lock);
 320 }
 321
 322 /* Make a copy of all potential local addresses. */
 323 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 324                                   struct net_device *dev)
 325 {
 326         struct inet6_dev *in6_dev;
 327         struct inet6_ifaddr *ifp;
 328         struct sctp_sockaddr_entry *addr;
 329
 330         read_lock(&addrconf_lock);
 331         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 332                 read_unlock(&addrconf_lock);
 333                 return;
 334         }
 335
 336         read_lock(&in6_dev->lock);
 337         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 338                 /* Add the address to the local list.  */
 339                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 340                 if (addr) {
 341                         addr->a.v6.sin6_family = AF_INET6;
 342                         addr->a.v6.sin6_port = 0;
 343                         addr->a.v6.sin6_addr = ifp->addr;
 344                         addr->a.v6.sin6_scope_id = dev->ifindex;
 345                         INIT_LIST_HEAD(&addr->list);
 346                         list_add_tail(&addr->list, addrlist);
 347                 }
 348         }
 349
 350         read_unlock(&in6_dev->lock);
 351         read_unlock(&addrconf_lock);
 352 }
 353
 354 /* Initialize a sockaddr_storage from in incoming skb. */
 355 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 356                              int is_saddr)
 357 {
 358         void *from;
 359         __u16 *port;
 360         struct sctphdr *sh;
 361
 362         port = &addr->v6.sin6_port;
 363         addr->v6.sin6_family = AF_INET6;
 364         addr->v6.sin6_flowinfo = 0; /* FIXME */
 365         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 366
 367         sh = (struct sctphdr *) skb->h.raw;
 368         if (is_saddr) {
 369                 *port  = ntohs(sh->source);
 370                 from = &skb->nh.ipv6h->saddr;
 371         } else {
 372                 *port = ntohs(sh->dest);
 373                 from = &skb->nh.ipv6h->daddr;
 374         }
 375         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 376 }
 377
 378 /* Initialize an sctp_addr from a socket. */
 379 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 380 {
 381         addr->v6.sin6_family = AF_INET6;
 382         addr->v6.sin6_port = inet_sk(sk)->num;
 383         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 384 }
 385
 386 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 387 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 388 {
 389         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 390                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 391                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 392                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 393                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 394                         addr->v4.sin_addr.s_addr;
 395         } else {
 396                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 397         }
 398 }
 399
 400 /* Initialize sk->sk_daddr from sctp_addr. */
 401 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 402 {
 403         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 404                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 405                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 406                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 407                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 408         } else {
 409                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 410         }
 411 }
 412
 413 /* Initialize a sctp_addr from an address parameter. */
 414 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 415                                     union sctp_addr_param *param,
 416                                     __u16 port, int iif)
 417 {
 418         addr->v6.sin6_family = AF_INET6;
 419         addr->v6.sin6_port = port;
 420         addr->v6.sin6_flowinfo = 0; /* BUG */
 421         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 422         addr->v6.sin6_scope_id = iif;
 423 }
 424
 425 /* Initialize an address parameter from a sctp_addr and return the length
 426  * of the address parameter.
 427  */
 428 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 429                                  union sctp_addr_param *param)
 430 {
 431         int length = sizeof(sctp_ipv6addr_param_t);
 432
 433         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 434         param->v6.param_hdr.length = ntohs(length);
 435         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 436
 437         return length;
 438 }
 439
 440 /* Initialize a sctp_addr from a dst_entry. */
 441 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 442                               unsigned short port)
 443 {
 444         struct rt6_info *rt = (struct rt6_info *)dst;
 445         addr->sa.sa_family = AF_INET6;
 446         addr->v6.sin6_port = port;
 447         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 448 }
 449
 450 /* Compare addresses exactly.
 451  * v4-mapped-v6 is also in consideration.
 452  */
 453 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 454                             const union sctp_addr *addr2)
 455 {
 456         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 457                 if (addr1->sa.sa_family == AF_INET &&
 458                     addr2->sa.sa_family == AF_INET6 &&
 459                     IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
 460                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 461                             addr2->v6.sin6_addr.s6_addr32[3] ==
 462                             addr1->v4.sin_addr.s_addr)
 463                                 return 1;
 464                 }
 465                 if (addr2->sa.sa_family == AF_INET &&
 466                     addr1->sa.sa_family == AF_INET6 &&
 467                     IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
 468                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 469                             addr1->v6.sin6_addr.s6_addr32[3] ==
 470                             addr2->v4.sin_addr.s_addr)
 471                                 return 1;
 472                 }
 473                 return 0;
 474         }
 475         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 476                 return 0;
 477         /* If this is a linklocal address, compare the scope_id. */
 478         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 479                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 480                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 481                         return 0;
 482                 }
 483         }
 484
 485         return 1;
 486 }
 487
 488 /* Initialize addr struct to INADDR_ANY. */
 489 static void sctp_v6_inaddr_any(union sctp_addr *addr, unsigned short port)
 490 {
 491         memset(addr, 0x00, sizeof(union sctp_addr));
 492         addr->v6.sin6_family = AF_INET6;
 493         addr->v6.sin6_port = port;
 494 }
 495
 496 /* Is this a wildcard address? */
 497 static int sctp_v6_is_any(const union sctp_addr *addr)
 498 {
 499         return ipv6_addr_any(&addr->v6.sin6_addr);
 500 }
 501
 502 /* Should this be available for binding?   */
 503 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 504 {
 505         int type;
 506         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 507
 508         type = ipv6_addr_type(in6);
 509         if (IPV6_ADDR_ANY == type)
 510                 return 1;
 511         if (type == IPV6_ADDR_MAPPED) {
 512                 if (sp && !sp->v4mapped)
 513                         return 0;
 514                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 515                         return 0;
 516                 sctp_v6_map_v4(addr);
 517                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 518         }
 519         if (!(type & IPV6_ADDR_UNICAST))
 520                 return 0;
 521
 522         return ipv6_chk_addr(in6, NULL, 0);
 523 }
 524
 525 /* This function checks if the address is a valid address to be used for
 526  * SCTP.
 527  *
 528  * Output:
 529  * Return 0 - If the address is a non-unicast or an illegal address.
 530  * Return 1 - If the address is a unicast.
 531  */
 532 static int sctp_v6_addr_valid(union sctp_addr *addr, struct sctp_sock *sp)
 533 {
 534         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 535
 536         /* Support v4-mapped-v6 address. */
 537         if (ret == IPV6_ADDR_MAPPED) {
 538                 /* Note: This routine is used in input, so v4-mapped-v6
 539                  * are disallowed here when there is no sctp_sock.
 540                  */
 541                 if (!sp || !sp->v4mapped)
 542                         return 0;
 543                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 544                         return 0;
 545                 sctp_v6_map_v4(addr);
 546                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp);
 547         }
 548
 549         /* Is this a non-unicast address */
 550         if (!(ret & IPV6_ADDR_UNICAST))
 551                 return 0;
 552
 553         return 1;
 554 }
 555
 556 /* What is the scope of 'addr'?  */
 557 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 558 {
 559         int v6scope;
 560         sctp_scope_t retval;
 561
 562         /* The IPv6 scope is really a set of bit fields.
 563          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 564          */
 565
 566         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 567         switch (v6scope) {
 568         case IFA_HOST:
 569                 retval = SCTP_SCOPE_LOOPBACK;
 570                 break;
 571         case IFA_LINK:
 572                 retval = SCTP_SCOPE_LINK;
 573                 break;
 574         case IFA_SITE:
 575                 retval = SCTP_SCOPE_PRIVATE;
 576                 break;
 577         default:
 578                 retval = SCTP_SCOPE_GLOBAL;
 579                 break;
 580         };
 581
 582         return retval;
 583 }
 584
 585 /* Create and initialize a new sk for the socket to be returned by accept(). */
 586 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 587                                              struct sctp_association *asoc)
 588 {
 589         struct inet_sock *inet = inet_sk(sk);
 590         struct sock *newsk;
 591         struct inet_sock *newinet;
 592         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 593         struct sctp6_sock *newsctp6sk;
 594
 595         newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot, 1);
 596         if (!newsk)
 597                 goto out;
 598
 599         sock_init_data(NULL, newsk);
 600
 601         newsk->sk_type = SOCK_STREAM;
 602
 603         newsk->sk_prot = sk->sk_prot;
 604         newsk->sk_no_check = sk->sk_no_check;
 605         newsk->sk_reuse = sk->sk_reuse;
 606
 607         newsk->sk_destruct = inet_sock_destruct;
 608         newsk->sk_family = PF_INET6;
 609         newsk->sk_protocol = IPPROTO_SCTP;
 610         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 611         newsk->sk_shutdown = sk->sk_shutdown;
 612         sock_reset_flag(sk, SOCK_ZAPPED);
 613
 614         newsctp6sk = (struct sctp6_sock *)newsk;
 615         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 616
 617         newinet = inet_sk(newsk);
 618         newnp = inet6_sk(newsk);
 619
 620         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 621
 622         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 623          * and getpeername().
 624          */
 625         newinet->sport = inet->sport;
 626         newnp->saddr = np->saddr;
 627         newnp->rcv_saddr = np->rcv_saddr;
 628         newinet->dport = htons(asoc->peer.port);
 629         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 630
 631         /* Init the ipv4 part of the socket since we can have sockets
 632          * using v6 API for ipv4.
 633          */
 634         newinet->uc_ttl = -1;
 635         newinet->mc_loop = 1;
 636         newinet->mc_ttl = 1;
 637         newinet->mc_index = 0;
 638         newinet->mc_list = NULL;
 639
 640         if (ipv4_config.no_pmtu_disc)
 641                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 642         else
 643                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 644
 645 #ifdef INET_REFCNT_DEBUG
 646         atomic_inc(&inet6_sock_nr);
 647         atomic_inc(&inet_sock_nr);
 648 #endif
 649
 650         if (newsk->sk_prot->init(newsk)) {
 651                 sk_common_release(newsk);
 652                 newsk = NULL;
 653         }
 654
 655 out:
 656         return newsk;
 657 }
 658
 659 /* Map v4 address to mapped v6 address */
 660 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 661 {
 662         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 663                 sctp_v4_map_v6(addr);
 664 }
 665
 666 /* Where did this skb come from?  */
 667 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 668 {
 669         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 670         return opt->iif;
 671 }
 672
 673 /* Was this packet marked by Explicit Congestion Notification? */
 674 static int sctp_v6_is_ce(const struct sk_buff *skb)
 675 {
 676         return *((__u32 *)(skb->nh.ipv6h)) & htonl(1<<20);
 677 }
 678
 679 /* Dump the v6 addr to the seq file. */
 680 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 681 {
 682         seq_printf(seq, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
 683                    NIP6(addr->v6.sin6_addr));
 684 }
 685
 686 /* Initialize a PF_INET6 socket msg_name. */
 687 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 688 {
 689         struct sockaddr_in6 *sin6;
 690
 691         sin6 = (struct sockaddr_in6 *)msgname;
 692         sin6->sin6_family = AF_INET6;
 693         sin6->sin6_flowinfo = 0;
 694         sin6->sin6_scope_id = 0; /*FIXME */
 695         *addr_len = sizeof(struct sockaddr_in6);
 696 }
 697
 698 /* Initialize a PF_INET msgname from a ulpevent. */
 699 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 700                                      char *msgname, int *addrlen)
 701 {
 702         struct sockaddr_in6 *sin6, *sin6from;
 703
 704         if (msgname) {
 705                 union sctp_addr *addr;
 706                 struct sctp_association *asoc;
 707
 708                 asoc = event->asoc;
 709                 sctp_inet6_msgname(msgname, addrlen);
 710                 sin6 = (struct sockaddr_in6 *)msgname;
 711                 sin6->sin6_port = htons(asoc->peer.port);
 712                 addr = &asoc->peer.primary_addr;
 713
 714                 /* Note: If we go to a common v6 format, this code
 715                  * will change.
 716                  */
 717
 718                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 719                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 720                     AF_INET == addr->sa.sa_family) {
 721                         sctp_v4_map_v6((union sctp_addr *)sin6);
 722                         sin6->sin6_addr.s6_addr32[3] =
 723                                 addr->v4.sin_addr.s_addr;
 724                         return;
 725                 }
 726
 727                 sin6from = &asoc->peer.primary_addr.v6;
 728                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 729                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 730                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 731         }
 732 }
 733
 734 /* Initialize a msg_name from an inbound skb. */
 735 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 736                                    int *addr_len)
 737 {
 738         struct sctphdr *sh;
 739         struct sockaddr_in6 *sin6;
 740
 741         if (msgname) {
 742                 sctp_inet6_msgname(msgname, addr_len);
 743                 sin6 = (struct sockaddr_in6 *)msgname;
 744                 sh = (struct sctphdr *)skb->h.raw;
 745                 sin6->sin6_port = sh->source;
 746
 747                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 748                 if (sctp_sk(skb->sk)->v4mapped &&
 749                     skb->nh.iph->version == 4) {
 750                         sctp_v4_map_v6((union sctp_addr *)sin6);
 751                         sin6->sin6_addr.s6_addr32[3] = skb->nh.iph->saddr;
 752                         return;
 753                 }
 754
 755                 /* Otherwise, just copy the v6 address. */
 756                 ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
 757                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 758                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 759                         sin6->sin6_scope_id = ev->iif;
 760                 }
 761         }
 762 }
 763
 764 /* Do we support this AF? */
 765 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 766 {
 767         switch (family) {
 768         case AF_INET6:
 769                 return 1;
 770         /* v4-mapped-v6 addresses */
 771         case AF_INET:
 772                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
 773                         return 1;
 774         default:
 775                 return 0;
 776         }
 777 }
 778
 779 /* Address matching with wildcards allowed.  This extra level
 780  * of indirection lets us choose whether a PF_INET6 should
 781  * disallow any v4 addresses if we so choose.
 782  */
 783 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 784                                const union sctp_addr *addr2,
 785                                struct sctp_sock *opt)
 786 {
 787         struct sctp_af *af1, *af2;
 788
 789         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 790         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 791
 792         if (!af1 || !af2)
 793                 return 0;
 794         /* Today, wildcard AF_INET/AF_INET6. */
 795         if (sctp_is_any(addr1) || sctp_is_any(addr2))
 796                 return 1;
 797
 798         if (addr1->sa.sa_family != addr2->sa.sa_family)
 799                 return 0;
 800
 801         return af1->cmp_addr(addr1, addr2);
 802 }
 803
 804 /* Verify that the provided sockaddr looks bindable.   Common verification,
 805  * has already been taken care of.
 806  */
 807 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 808 {
 809         struct sctp_af *af;
 810
 811         /* ASSERT: address family has already been verified. */
 812         if (addr->sa.sa_family != AF_INET6)
 813                 af = sctp_get_af_specific(addr->sa.sa_family);
 814         else {
 815                 struct sock *sk;
 816                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 817                 sk = sctp_opt2sk(opt);
 818                 if (type & IPV6_ADDR_LINKLOCAL) {
 819                         /* Note: Behavior similar to af_inet6.c:
 820                          *  1) Overrides previous bound_dev_if
 821                          *  2) Destructive even if bind isn't successful.
 822                          */
 823
 824                         if (addr->v6.sin6_scope_id)
 825                                 sk->sk_bound_dev_if = addr->v6.sin6_scope_id;
 826                         if (!sk->sk_bound_dev_if)
 827                                 return 0;
 828                 }
 829                 af = opt->pf->af;
 830         }
 831         return af->available(addr, opt);
 832 }
 833
 834 /* Verify that the provided sockaddr looks bindable.   Common verification,
 835  * has already been taken care of.
 836  */
 837 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 838 {
 839         struct sctp_af *af = NULL;
 840
 841         /* ASSERT: address family has already been verified. */
 842         if (addr->sa.sa_family != AF_INET6)
 843                 af = sctp_get_af_specific(addr->sa.sa_family);
 844         else {
 845                 struct sock *sk;
 846                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 847                 sk = sctp_opt2sk(opt);
 848                 if (type & IPV6_ADDR_LINKLOCAL) {
 849                         /* Note: Behavior similar to af_inet6.c:
 850                          *  1) Overrides previous bound_dev_if
 851                          *  2) Destructive even if bind isn't successful.
 852                          */
 853
 854                         if (addr->v6.sin6_scope_id)
 855                                 sk->sk_bound_dev_if = addr->v6.sin6_scope_id;
 856                         if (!sk->sk_bound_dev_if)
 857                                 return 0;
 858                 }
 859                 af = opt->pf->af;
 860         }
 861
 862         return af != NULL;
 863 }
 864
 865 /* Fill in Supported Address Type information for INIT and INIT-ACK
 866  * chunks.   Note: In the future, we may want to look at sock options
 867  * to determine whether a PF_INET6 socket really wants to have IPV4
 868  * addresses.
 869  * Returns number of addresses supported.
 870  */
 871 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 872                                       __u16 *types)
 873 {
 874         types[0] = SCTP_PARAM_IPV4_ADDRESS;
 875         types[1] = SCTP_PARAM_IPV6_ADDRESS;
 876         return 2;
 877 }
 878
 879 static struct proto_ops inet6_seqpacket_ops = {
 880         .family     = PF_INET6,
 881         .owner      = THIS_MODULE,
 882         .release    = inet6_release,
 883         .bind       = inet6_bind,
 884         .connect    = inet_dgram_connect,
 885         .socketpair = sock_no_socketpair,
 886         .accept     = inet_accept,
 887         .getname    = inet6_getname,
 888         .poll       = sctp_poll,
 889         .ioctl      = inet6_ioctl,
 890         .listen     = sctp_inet_listen,
 891         .shutdown   = inet_shutdown,
 892         .setsockopt = sock_common_setsockopt,
 893         .getsockopt = sock_common_getsockopt,
 894         .sendmsg    = inet_sendmsg,
 895         .recvmsg    = sock_common_recvmsg,
 896         .mmap       = sock_no_mmap,
 897 };
 898
 899 static struct inet_protosw sctpv6_seqpacket_protosw = {
 900         .type          = SOCK_SEQPACKET,
 901         .protocol      = IPPROTO_SCTP,
 902         .prot          = &sctpv6_prot,
 903         .ops           = &inet6_seqpacket_ops,
 904         .capability    = -1,
 905         .no_check      = 0,
 906         .flags         = SCTP_PROTOSW_FLAG
 907 };
 908 static struct inet_protosw sctpv6_stream_protosw = {
 909         .type          = SOCK_STREAM,
 910         .protocol      = IPPROTO_SCTP,
 911         .prot          = &sctpv6_prot,
 912         .ops           = &inet6_seqpacket_ops,
 913         .capability    = -1,
 914         .no_check      = 0,
 915         .flags         = SCTP_PROTOSW_FLAG,
 916 };
 917
 918 static int sctp6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
 919 {
 920         return sctp_rcv(*pskb) ? -1 : 0;
 921 }
 922
 923 static struct inet6_protocol sctpv6_protocol = {
 924         .handler      = sctp6_rcv,
 925         .err_handler  = sctp_v6_err,
 926         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 927 };
 928
 929 static struct sctp_af sctp_ipv6_specific = {
 930         .sctp_xmit       = sctp_v6_xmit,
 931         .setsockopt      = ipv6_setsockopt,
 932         .getsockopt      = ipv6_getsockopt,
 933         .get_dst         = sctp_v6_get_dst,
 934         .get_saddr       = sctp_v6_get_saddr,
 935         .copy_addrlist   = sctp_v6_copy_addrlist,
 936         .from_skb        = sctp_v6_from_skb,
 937         .from_sk         = sctp_v6_from_sk,
 938         .to_sk_saddr     = sctp_v6_to_sk_saddr,
 939         .to_sk_daddr     = sctp_v6_to_sk_daddr,
 940         .from_addr_param = sctp_v6_from_addr_param,
 941         .to_addr_param   = sctp_v6_to_addr_param,
 942         .dst_saddr       = sctp_v6_dst_saddr,
 943         .cmp_addr        = sctp_v6_cmp_addr,
 944         .scope           = sctp_v6_scope,
 945         .addr_valid      = sctp_v6_addr_valid,
 946         .inaddr_any      = sctp_v6_inaddr_any,
 947         .is_any          = sctp_v6_is_any,
 948         .available       = sctp_v6_available,
 949         .skb_iif         = sctp_v6_skb_iif,
 950         .is_ce           = sctp_v6_is_ce,
 951         .seq_dump_addr   = sctp_v6_seq_dump_addr,
 952         .net_header_len  = sizeof(struct ipv6hdr),
 953         .sockaddr_len    = sizeof(struct sockaddr_in6),
 954         .sa_family       = AF_INET6,
 955 };
 956
 957 static struct sctp_pf sctp_pf_inet6_specific = {
 958         .event_msgname = sctp_inet6_event_msgname,
 959         .skb_msgname   = sctp_inet6_skb_msgname,
 960         .af_supported  = sctp_inet6_af_supported,
 961         .cmp_addr      = sctp_inet6_cmp_addr,
 962         .bind_verify   = sctp_inet6_bind_verify,
 963         .send_verify   = sctp_inet6_send_verify,
 964         .supported_addrs = sctp_inet6_supported_addrs,
 965         .create_accept_sk = sctp_v6_create_accept_sk,
 966         .addr_v4map    = sctp_v6_addr_v4map,
 967         .af            = &sctp_ipv6_specific,
 968 };
 969
 970 /* Initialize IPv6 support and register with inet6 stack.  */
 971 int sctp_v6_init(void)
 972 {
 973         int rc = proto_register(&sctpv6_prot, 1);
 974
 975         if (rc)
 976                 goto out;
 977         /* Register inet6 protocol. */
 978         rc = -EAGAIN;
 979         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
 980                 goto out_unregister_sctp_proto;
 981
 982         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
 983         inet6_register_protosw(&sctpv6_seqpacket_protosw);
 984         inet6_register_protosw(&sctpv6_stream_protosw);
 985
 986         /* Register the SCTP specific PF_INET6 functions. */
 987         sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
 988
 989         /* Register the SCTP specific AF_INET6 functions. */
 990         sctp_register_af(&sctp_ipv6_specific);
 991
 992         /* Register notifier for inet6 address additions/deletions. */
 993         register_inet6addr_notifier(&sctp_inet6addr_notifier);
 994         rc = 0;
 995 out:
 996         return rc;
 997 out_unregister_sctp_proto:
 998         proto_unregister(&sctpv6_prot);
 999         goto out;
1000 }
1001
1002 /* IPv6 specific exit support. */
1003 void sctp_v6_exit(void)
1004 {
1005         list_del(&sctp_ipv6_specific.list);
1006         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1007         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1008         inet6_unregister_protosw(&sctpv6_stream_protosw);
1009         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1010         proto_unregister(&sctpv6_prot);
1011 }