linux/net/sctp/ipv6.c
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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#include <linux/slab.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/ndisc.h>
  70#include <net/ip.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/* Event handler for inet6 address addition/deletion events.
  82 * The sctp_local_addr_list needs to be protocted by a spin lock since
  83 * multiple notifiers (say IPv4 and IPv6) may be running at the same
  84 * time and thus corrupt the list.
  85 * The reader side is protected with RCU.
  86 */
  87static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  88                                void *ptr)
  89{
  90        struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  91        struct sctp_sockaddr_entry *addr = NULL;
  92        struct sctp_sockaddr_entry *temp;
  93        int found = 0;
  94
  95        switch (ev) {
  96        case NETDEV_UP:
  97                addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  98                if (addr) {
  99                        addr->a.v6.sin6_family = AF_INET6;
 100                        addr->a.v6.sin6_port = 0;
 101                        ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifa->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
 131static struct notifier_block sctp_inet6addr_notifier = {
 132        .notifier_call = sctp_inet6addr_event,
 133};
 134
 135/* ICMP error handler. */
 136SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 137                             u8 type, u8 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
 190out_unlock:
 191        sctp_err_finish(sk, asoc);
 192out:
 193        if (likely(idev != NULL))
 194                in6_dev_put(idev);
 195}
 196
 197/* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 198static 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);
 236}
 237
 238/* Returns the dst cache entry for the given source and destination ip
 239 * addresses.
 240 */
 241static 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 */
 277static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 278                                         union sctp_addr *s2)
 279{
 280        return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 281}
 282
 283/* Fills in the source address(saddr) based on the destination address(daddr)
 284 * and asoc's bind address list.
 285 */
 286static void sctp_v6_get_saddr(struct sctp_sock *sk,
 287                              struct sctp_association *asoc,
 288                              struct dst_entry *dst,
 289                              union sctp_addr *daddr,
 290                              union sctp_addr *saddr)
 291{
 292        struct sctp_bind_addr *bp;
 293        struct sctp_sockaddr_entry *laddr;
 294        sctp_scope_t scope;
 295        union sctp_addr *baddr = NULL;
 296        __u8 matchlen = 0;
 297        __u8 bmatchlen;
 298
 299        SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p daddr:%pI6 ",
 300                          __func__, asoc, dst, &daddr->v6.sin6_addr);
 301
 302        if (!asoc) {
 303                ipv6_dev_get_saddr(sock_net(sctp_opt2sk(sk)),
 304                                   dst ? ip6_dst_idev(dst)->dev : NULL,
 305                                   &daddr->v6.sin6_addr,
 306                                   inet6_sk(&sk->inet.sk)->srcprefs,
 307                                   &saddr->v6.sin6_addr);
 308                SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: %pI6\n",
 309                                  &saddr->v6.sin6_addr);
 310                return;
 311        }
 312
 313        scope = sctp_scope(daddr);
 314
 315        bp = &asoc->base.bind_addr;
 316
 317        /* Go through the bind address list and find the best source address
 318         * that matches the scope of the destination address.
 319         */
 320        rcu_read_lock();
 321        list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 322                if (!laddr->valid)
 323                        continue;
 324                if ((laddr->state == SCTP_ADDR_SRC) &&
 325                    (laddr->a.sa.sa_family == AF_INET6) &&
 326                    (scope <= sctp_scope(&laddr->a))) {
 327                        bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 328                        if (!baddr || (matchlen < bmatchlen)) {
 329                                baddr = &laddr->a;
 330                                matchlen = bmatchlen;
 331                        }
 332                }
 333        }
 334
 335        if (baddr) {
 336                memcpy(saddr, baddr, sizeof(union sctp_addr));
 337                SCTP_DEBUG_PRINTK("saddr: %pI6\n", &saddr->v6.sin6_addr);
 338        } else {
 339                printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 340                       "address for the dest:%pI6\n",
 341                       __func__, asoc, &daddr->v6.sin6_addr);
 342        }
 343
 344        rcu_read_unlock();
 345}
 346
 347/* Make a copy of all potential local addresses. */
 348static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 349                                  struct net_device *dev)
 350{
 351        struct inet6_dev *in6_dev;
 352        struct inet6_ifaddr *ifp;
 353        struct sctp_sockaddr_entry *addr;
 354
 355        rcu_read_lock();
 356        if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 357                rcu_read_unlock();
 358                return;
 359        }
 360
 361        read_lock_bh(&in6_dev->lock);
 362        list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 363                /* Add the address to the local list.  */
 364                addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 365                if (addr) {
 366                        addr->a.v6.sin6_family = AF_INET6;
 367                        addr->a.v6.sin6_port = 0;
 368                        ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifp->addr);
 369                        addr->a.v6.sin6_scope_id = dev->ifindex;
 370                        addr->valid = 1;
 371                        INIT_LIST_HEAD(&addr->list);
 372                        list_add_tail(&addr->list, addrlist);
 373                }
 374        }
 375
 376        read_unlock_bh(&in6_dev->lock);
 377        rcu_read_unlock();
 378}
 379
 380/* Initialize a sockaddr_storage from in incoming skb. */
 381static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 382                             int is_saddr)
 383{
 384        void *from;
 385        __be16 *port;
 386        struct sctphdr *sh;
 387
 388        port = &addr->v6.sin6_port;
 389        addr->v6.sin6_family = AF_INET6;
 390        addr->v6.sin6_flowinfo = 0; /* FIXME */
 391        addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 392
 393        sh = sctp_hdr(skb);
 394        if (is_saddr) {
 395                *port  = sh->source;
 396                from = &ipv6_hdr(skb)->saddr;
 397        } else {
 398                *port = sh->dest;
 399                from = &ipv6_hdr(skb)->daddr;
 400        }
 401        ipv6_addr_copy(&addr->v6.sin6_addr, from);
 402}
 403
 404/* Initialize an sctp_addr from a socket. */
 405static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 406{
 407        addr->v6.sin6_family = AF_INET6;
 408        addr->v6.sin6_port = 0;
 409        ipv6_addr_copy(&addr->v6.sin6_addr, &inet6_sk(sk)->rcv_saddr);
 410}
 411
 412/* Initialize sk->sk_rcv_saddr from sctp_addr. */
 413static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 414{
 415        if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 416                inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 417                inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 418                inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 419                inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 420                        addr->v4.sin_addr.s_addr;
 421        } else {
 422                ipv6_addr_copy(&inet6_sk(sk)->rcv_saddr, &addr->v6.sin6_addr);
 423        }
 424}
 425
 426/* Initialize sk->sk_daddr from sctp_addr. */
 427static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 428{
 429        if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 430                inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 431                inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 432                inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 433                inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 434        } else {
 435                ipv6_addr_copy(&inet6_sk(sk)->daddr, &addr->v6.sin6_addr);
 436        }
 437}
 438
 439/* Initialize a sctp_addr from an address parameter. */
 440static void sctp_v6_from_addr_param(union sctp_addr *addr,
 441                                    union sctp_addr_param *param,
 442                                    __be16 port, int iif)
 443{
 444        addr->v6.sin6_family = AF_INET6;
 445        addr->v6.sin6_port = port;
 446        addr->v6.sin6_flowinfo = 0; /* BUG */
 447        ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 448        addr->v6.sin6_scope_id = iif;
 449}
 450
 451/* Initialize an address parameter from a sctp_addr and return the length
 452 * of the address parameter.
 453 */
 454static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 455                                 union sctp_addr_param *param)
 456{
 457        int length = sizeof(sctp_ipv6addr_param_t);
 458
 459        param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 460        param->v6.param_hdr.length = htons(length);
 461        ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 462
 463        return length;
 464}
 465
 466/* Initialize a sctp_addr from a dst_entry. */
 467static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 468                              __be16 port)
 469{
 470        struct rt6_info *rt = (struct rt6_info *)dst;
 471        addr->sa.sa_family = AF_INET6;
 472        addr->v6.sin6_port = port;
 473        ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 474}
 475
 476/* Compare addresses exactly.
 477 * v4-mapped-v6 is also in consideration.
 478 */
 479static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 480                            const union sctp_addr *addr2)
 481{
 482        if (addr1->sa.sa_family != addr2->sa.sa_family) {
 483                if (addr1->sa.sa_family == AF_INET &&
 484                    addr2->sa.sa_family == AF_INET6 &&
 485                    ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 486                        if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 487                            addr2->v6.sin6_addr.s6_addr32[3] ==
 488                            addr1->v4.sin_addr.s_addr)
 489                                return 1;
 490                }
 491                if (addr2->sa.sa_family == AF_INET &&
 492                    addr1->sa.sa_family == AF_INET6 &&
 493                    ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 494                        if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 495                            addr1->v6.sin6_addr.s6_addr32[3] ==
 496                            addr2->v4.sin_addr.s_addr)
 497                                return 1;
 498                }
 499                return 0;
 500        }
 501        if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 502                return 0;
 503        /* If this is a linklocal address, compare the scope_id. */
 504        if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 505                if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 506                    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 507                        return 0;
 508                }
 509        }
 510
 511        return 1;
 512}
 513
 514/* Initialize addr struct to INADDR_ANY. */
 515static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 516{
 517        memset(addr, 0x00, sizeof(union sctp_addr));
 518        addr->v6.sin6_family = AF_INET6;
 519        addr->v6.sin6_port = port;
 520}
 521
 522/* Is this a wildcard address? */
 523static int sctp_v6_is_any(const union sctp_addr *addr)
 524{
 525        return ipv6_addr_any(&addr->v6.sin6_addr);
 526}
 527
 528/* Should this be available for binding?   */
 529static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 530{
 531        int type;
 532        struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 533
 534        type = ipv6_addr_type(in6);
 535        if (IPV6_ADDR_ANY == type)
 536                return 1;
 537        if (type == IPV6_ADDR_MAPPED) {
 538                if (sp && !sp->v4mapped)
 539                        return 0;
 540                if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 541                        return 0;
 542                sctp_v6_map_v4(addr);
 543                return sctp_get_af_specific(AF_INET)->available(addr, sp);
 544        }
 545        if (!(type & IPV6_ADDR_UNICAST))
 546                return 0;
 547
 548        return ipv6_chk_addr(&init_net, in6, NULL, 0);
 549}
 550
 551/* This function checks if the address is a valid address to be used for
 552 * SCTP.
 553 *
 554 * Output:
 555 * Return 0 - If the address is a non-unicast or an illegal address.
 556 * Return 1 - If the address is a unicast.
 557 */
 558static int sctp_v6_addr_valid(union sctp_addr *addr,
 559                              struct sctp_sock *sp,
 560                              const struct sk_buff *skb)
 561{
 562        int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 563
 564        /* Support v4-mapped-v6 address. */
 565        if (ret == IPV6_ADDR_MAPPED) {
 566                /* Note: This routine is used in input, so v4-mapped-v6
 567                 * are disallowed here when there is no sctp_sock.
 568                 */
 569                if (!sp || !sp->v4mapped)
 570                        return 0;
 571                if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 572                        return 0;
 573                sctp_v6_map_v4(addr);
 574                return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 575        }
 576
 577        /* Is this a non-unicast address */
 578        if (!(ret & IPV6_ADDR_UNICAST))
 579                return 0;
 580
 581        return 1;
 582}
 583
 584/* What is the scope of 'addr'?  */
 585static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 586{
 587        int v6scope;
 588        sctp_scope_t retval;
 589
 590        /* The IPv6 scope is really a set of bit fields.
 591         * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 592         */
 593
 594        v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 595        switch (v6scope) {
 596        case IFA_HOST:
 597                retval = SCTP_SCOPE_LOOPBACK;
 598                break;
 599        case IFA_LINK:
 600                retval = SCTP_SCOPE_LINK;
 601                break;
 602        case IFA_SITE:
 603                retval = SCTP_SCOPE_PRIVATE;
 604                break;
 605        default:
 606                retval = SCTP_SCOPE_GLOBAL;
 607                break;
 608        }
 609
 610        return retval;
 611}
 612
 613/* Create and initialize a new sk for the socket to be returned by accept(). */
 614static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 615                                             struct sctp_association *asoc)
 616{
 617        struct sock *newsk;
 618        struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 619        struct sctp6_sock *newsctp6sk;
 620
 621        newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 622        if (!newsk)
 623                goto out;
 624
 625        sock_init_data(NULL, newsk);
 626
 627        sctp_copy_sock(newsk, sk, asoc);
 628        sock_reset_flag(sk, SOCK_ZAPPED);
 629
 630        newsctp6sk = (struct sctp6_sock *)newsk;
 631        inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 632
 633        sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 634
 635        newnp = inet6_sk(newsk);
 636
 637        memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 638
 639        /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 640         * and getpeername().
 641         */
 642        sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 643
 644        sk_refcnt_debug_inc(newsk);
 645
 646        if (newsk->sk_prot->init(newsk)) {
 647                sk_common_release(newsk);
 648                newsk = NULL;
 649        }
 650
 651out:
 652        return newsk;
 653}
 654
 655/* Map v4 address to mapped v6 address */
 656static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 657{
 658        if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 659                sctp_v4_map_v6(addr);
 660}
 661
 662/* Where did this skb come from?  */
 663static int sctp_v6_skb_iif(const struct sk_buff *skb)
 664{
 665        struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 666        return opt->iif;
 667}
 668
 669/* Was this packet marked by Explicit Congestion Notification? */
 670static int sctp_v6_is_ce(const struct sk_buff *skb)
 671{
 672        return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 673}
 674
 675/* Dump the v6 addr to the seq file. */
 676static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 677{
 678        seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 679}
 680
 681static void sctp_v6_ecn_capable(struct sock *sk)
 682{
 683        inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 684}
 685
 686/* Initialize a PF_INET6 socket msg_name. */
 687static 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. */
 699static 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. */
 735static 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 = sctp_hdr(skb);
 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                    ip_hdr(skb)->version == 4) {
 750                        sctp_v4_map_v6((union sctp_addr *)sin6);
 751                        sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 752                        return;
 753                }
 754
 755                /* Otherwise, just copy the v6 address. */
 756                ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->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? */
 765static 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)))
 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 */
 783static 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        struct sock *sk = sctp_opt2sk(opt);
 789
 790        af1 = sctp_get_af_specific(addr1->sa.sa_family);
 791        af2 = sctp_get_af_specific(addr2->sa.sa_family);
 792
 793        if (!af1 || !af2)
 794                return 0;
 795
 796        /* If the socket is IPv6 only, v4 addrs will not match */
 797        if (__ipv6_only_sock(sk) && af1 != af2)
 798                return 0;
 799
 800        /* Today, wildcard AF_INET/AF_INET6. */
 801        if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 802                return 1;
 803
 804        if (addr1->sa.sa_family != addr2->sa.sa_family)
 805                return 0;
 806
 807        return af1->cmp_addr(addr1, addr2);
 808}
 809
 810/* Verify that the provided sockaddr looks bindable.   Common verification,
 811 * has already been taken care of.
 812 */
 813static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 814{
 815        struct sctp_af *af;
 816
 817        /* ASSERT: address family has already been verified. */
 818        if (addr->sa.sa_family != AF_INET6)
 819                af = sctp_get_af_specific(addr->sa.sa_family);
 820        else {
 821                int type = ipv6_addr_type(&addr->v6.sin6_addr);
 822                struct net_device *dev;
 823
 824                if (type & IPV6_ADDR_LINKLOCAL) {
 825                        if (!addr->v6.sin6_scope_id)
 826                                return 0;
 827                        rcu_read_lock();
 828                        dev = dev_get_by_index_rcu(&init_net,
 829                                                   addr->v6.sin6_scope_id);
 830                        if (!dev ||
 831                            !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 832                                           dev, 0)) {
 833                                rcu_read_unlock();
 834                                return 0;
 835                        }
 836                        rcu_read_unlock();
 837                } else if (type == IPV6_ADDR_MAPPED) {
 838                        if (!opt->v4mapped)
 839                                return 0;
 840                }
 841
 842                af = opt->pf->af;
 843        }
 844        return af->available(addr, opt);
 845}
 846
 847/* Verify that the provided sockaddr looks sendable.   Common verification,
 848 * has already been taken care of.
 849 */
 850static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 851{
 852        struct sctp_af *af = NULL;
 853
 854        /* ASSERT: address family has already been verified. */
 855        if (addr->sa.sa_family != AF_INET6)
 856                af = sctp_get_af_specific(addr->sa.sa_family);
 857        else {
 858                int type = ipv6_addr_type(&addr->v6.sin6_addr);
 859                struct net_device *dev;
 860
 861                if (type & IPV6_ADDR_LINKLOCAL) {
 862                        if (!addr->v6.sin6_scope_id)
 863                                return 0;
 864                        rcu_read_lock();
 865                        dev = dev_get_by_index_rcu(&init_net,
 866                                                   addr->v6.sin6_scope_id);
 867                        rcu_read_unlock();
 868                        if (!dev)
 869                                return 0;
 870                }
 871                af = opt->pf->af;
 872        }
 873
 874        return af != NULL;
 875}
 876
 877/* Fill in Supported Address Type information for INIT and INIT-ACK
 878 * chunks.   Note: In the future, we may want to look at sock options
 879 * to determine whether a PF_INET6 socket really wants to have IPV4
 880 * addresses.
 881 * Returns number of addresses supported.
 882 */
 883static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 884                                      __be16 *types)
 885{
 886        types[0] = SCTP_PARAM_IPV6_ADDRESS;
 887        if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 888                types[1] = SCTP_PARAM_IPV4_ADDRESS;
 889                return 2;
 890        }
 891        return 1;
 892}
 893
 894static const struct proto_ops inet6_seqpacket_ops = {
 895        .family            = PF_INET6,
 896        .owner             = THIS_MODULE,
 897        .release           = inet6_release,
 898        .bind              = inet6_bind,
 899        .connect           = inet_dgram_connect,
 900        .socketpair        = sock_no_socketpair,
 901        .accept            = inet_accept,
 902        .getname           = inet6_getname,
 903        .poll              = sctp_poll,
 904        .ioctl             = inet6_ioctl,
 905        .listen            = sctp_inet_listen,
 906        .shutdown          = inet_shutdown,
 907        .setsockopt        = sock_common_setsockopt,
 908        .getsockopt        = sock_common_getsockopt,
 909        .sendmsg           = inet_sendmsg,
 910        .recvmsg           = sock_common_recvmsg,
 911        .mmap              = sock_no_mmap,
 912#ifdef CONFIG_COMPAT
 913        .compat_setsockopt = compat_sock_common_setsockopt,
 914        .compat_getsockopt = compat_sock_common_getsockopt,
 915#endif
 916};
 917
 918static struct inet_protosw sctpv6_seqpacket_protosw = {
 919        .type          = SOCK_SEQPACKET,
 920        .protocol      = IPPROTO_SCTP,
 921        .prot          = &sctpv6_prot,
 922        .ops           = &inet6_seqpacket_ops,
 923        .no_check      = 0,
 924        .flags         = SCTP_PROTOSW_FLAG
 925};
 926static struct inet_protosw sctpv6_stream_protosw = {
 927        .type          = SOCK_STREAM,
 928        .protocol      = IPPROTO_SCTP,
 929        .prot          = &sctpv6_prot,
 930        .ops           = &inet6_seqpacket_ops,
 931        .no_check      = 0,
 932        .flags         = SCTP_PROTOSW_FLAG,
 933};
 934
 935static int sctp6_rcv(struct sk_buff *skb)
 936{
 937        return sctp_rcv(skb) ? -1 : 0;
 938}
 939
 940static const struct inet6_protocol sctpv6_protocol = {
 941        .handler      = sctp6_rcv,
 942        .err_handler  = sctp_v6_err,
 943        .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 944};
 945
 946static struct sctp_af sctp_af_inet6 = {
 947        .sa_family         = AF_INET6,
 948        .sctp_xmit         = sctp_v6_xmit,
 949        .setsockopt        = ipv6_setsockopt,
 950        .getsockopt        = ipv6_getsockopt,
 951        .get_dst           = sctp_v6_get_dst,
 952        .get_saddr         = sctp_v6_get_saddr,
 953        .copy_addrlist     = sctp_v6_copy_addrlist,
 954        .from_skb          = sctp_v6_from_skb,
 955        .from_sk           = sctp_v6_from_sk,
 956        .to_sk_saddr       = sctp_v6_to_sk_saddr,
 957        .to_sk_daddr       = sctp_v6_to_sk_daddr,
 958        .from_addr_param   = sctp_v6_from_addr_param,
 959        .to_addr_param     = sctp_v6_to_addr_param,
 960        .dst_saddr         = sctp_v6_dst_saddr,
 961        .cmp_addr          = sctp_v6_cmp_addr,
 962        .scope             = sctp_v6_scope,
 963        .addr_valid        = sctp_v6_addr_valid,
 964        .inaddr_any        = sctp_v6_inaddr_any,
 965        .is_any            = sctp_v6_is_any,
 966        .available         = sctp_v6_available,
 967        .skb_iif           = sctp_v6_skb_iif,
 968        .is_ce             = sctp_v6_is_ce,
 969        .seq_dump_addr     = sctp_v6_seq_dump_addr,
 970        .ecn_capable       = sctp_v6_ecn_capable,
 971        .net_header_len    = sizeof(struct ipv6hdr),
 972        .sockaddr_len      = sizeof(struct sockaddr_in6),
 973#ifdef CONFIG_COMPAT
 974        .compat_setsockopt = compat_ipv6_setsockopt,
 975        .compat_getsockopt = compat_ipv6_getsockopt,
 976#endif
 977};
 978
 979static struct sctp_pf sctp_pf_inet6 = {
 980        .event_msgname = sctp_inet6_event_msgname,
 981        .skb_msgname   = sctp_inet6_skb_msgname,
 982        .af_supported  = sctp_inet6_af_supported,
 983        .cmp_addr      = sctp_inet6_cmp_addr,
 984        .bind_verify   = sctp_inet6_bind_verify,
 985        .send_verify   = sctp_inet6_send_verify,
 986        .supported_addrs = sctp_inet6_supported_addrs,
 987        .create_accept_sk = sctp_v6_create_accept_sk,
 988        .addr_v4map    = sctp_v6_addr_v4map,
 989        .af            = &sctp_af_inet6,
 990};
 991
 992/* Initialize IPv6 support and register with socket layer.  */
 993void sctp_v6_pf_init(void)
 994{
 995        /* Register the SCTP specific PF_INET6 functions. */
 996        sctp_register_pf(&sctp_pf_inet6, PF_INET6);
 997
 998        /* Register the SCTP specific AF_INET6 functions. */
 999        sctp_register_af(&sctp_af_inet6);
1000}
1001
1002void sctp_v6_pf_exit(void)
1003{
1004        list_del(&sctp_af_inet6.list);
1005}
1006
1007/* Initialize IPv6 support and register with socket layer.  */
1008int sctp_v6_protosw_init(void)
1009{
1010        int rc;
1011
1012        rc = proto_register(&sctpv6_prot, 1);
1013        if (rc)
1014                return rc;
1015
1016        /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1017        inet6_register_protosw(&sctpv6_seqpacket_protosw);
1018        inet6_register_protosw(&sctpv6_stream_protosw);
1019
1020        return 0;
1021}
1022
1023void sctp_v6_protosw_exit(void)
1024{
1025        inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1026        inet6_unregister_protosw(&sctpv6_stream_protosw);
1027        proto_unregister(&sctpv6_prot);
1028}
1029
1030
1031/* Register with inet6 layer. */
1032int sctp_v6_add_protocol(void)
1033{
1034        /* Register notifier for inet6 address additions/deletions. */
1035        register_inet6addr_notifier(&sctp_inet6addr_notifier);
1036
1037        if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1038                return -EAGAIN;
1039
1040        return 0;
1041}
1042
1043/* Unregister with inet6 layer. */
1044void sctp_v6_del_protocol(void)
1045{
1046        inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1047        unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1048}
1049