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
  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 */
  86static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  87                                void *ptr)
  88{
  89        struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  90        struct sctp_sockaddr_entry *addr = NULL;
  91        struct sctp_sockaddr_entry *temp;
  92        int found = 0;
  93
  94        switch (ev) {
  95        case NETDEV_UP:
  96                addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  97                if (addr) {
  98                        addr->a.v6.sin6_family = AF_INET6;
  99                        addr->a.v6.sin6_port = 0;
 100                        memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
 101                                 sizeof(struct in6_addr));
 102                        addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 103                        addr->valid = 1;
 104                        spin_lock_bh(&sctp_local_addr_lock);
 105                        list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
 106                        spin_unlock_bh(&sctp_local_addr_lock);
 107                }
 108                break;
 109        case NETDEV_DOWN:
 110                spin_lock_bh(&sctp_local_addr_lock);
 111                list_for_each_entry_safe(addr, temp,
 112                                        &sctp_local_addr_list, list) {
 113                        if (addr->a.sa.sa_family == AF_INET6 &&
 114                                        ipv6_addr_equal(&addr->a.v6.sin6_addr,
 115                                                &ifa->addr)) {
 116                                found = 1;
 117                                addr->valid = 0;
 118                                list_del_rcu(&addr->list);
 119                                break;
 120                        }
 121                }
 122                spin_unlock_bh(&sctp_local_addr_lock);
 123                if (found)
 124                        call_rcu(&addr->rcu, sctp_local_addr_free);
 125                break;
 126        }
 127
 128        return NOTIFY_DONE;
 129}
 130
 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                             int type, int code, int offset, __be32 info)
 138{
 139        struct inet6_dev *idev;
 140        struct sock *sk;
 141        struct sctp_association *asoc;
 142        struct sctp_transport *transport;
 143        struct ipv6_pinfo *np;
 144        sk_buff_data_t saveip, savesctp;
 145        int err;
 146
 147        idev = in6_dev_get(skb->dev);
 148
 149        /* Fix up skb to look at the embedded net header. */
 150        saveip   = skb->network_header;
 151        savesctp = skb->transport_header;
 152        skb_reset_network_header(skb);
 153        skb_set_transport_header(skb, offset);
 154        sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 155        /* Put back, the original pointers. */
 156        skb->network_header   = saveip;
 157        skb->transport_header = savesctp;
 158        if (!sk) {
 159                ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
 160                goto out;
 161        }
 162
 163        /* Warning:  The sock lock is held.  Remember to call
 164         * sctp_err_finish!
 165         */
 166
 167        switch (type) {
 168        case ICMPV6_PKT_TOOBIG:
 169                sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 170                goto out_unlock;
 171        case ICMPV6_PARAMPROB:
 172                if (ICMPV6_UNK_NEXTHDR == code) {
 173                        sctp_icmp_proto_unreachable(sk, asoc, transport);
 174                        goto out_unlock;
 175                }
 176                break;
 177        default:
 178                break;
 179        }
 180
 181        np = inet6_sk(sk);
 182        icmpv6_err_convert(type, code, &err);
 183        if (!sock_owned_by_user(sk) && np->recverr) {
 184                sk->sk_err = err;
 185                sk->sk_error_report(sk);
 186        } else {  /* Only an error on timeout */
 187                sk->sk_err_soft = err;
 188        }
 189
 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, 0);
 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        struct in6_addr *a1 = &s1->v6.sin6_addr;
 281        struct in6_addr *a2 = &s2->v6.sin6_addr;
 282        int i, j;
 283
 284        for (i = 0; i < 4 ; i++) {
 285                __be32 a1xora2;
 286
 287                a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 288
 289                if ((j = fls(ntohl(a1xora2))))
 290                        return (i * 32 + 32 - j);
 291        }
 292
 293        return (i*32);
 294}
 295
 296/* Fills in the source address(saddr) based on the destination address(daddr)
 297 * and asoc's bind address list.
 298 */
 299static void sctp_v6_get_saddr(struct sctp_sock *sk,
 300                              struct sctp_association *asoc,
 301                              struct dst_entry *dst,
 302                              union sctp_addr *daddr,
 303                              union sctp_addr *saddr)
 304{
 305        struct sctp_bind_addr *bp;
 306        struct sctp_sockaddr_entry *laddr;
 307        sctp_scope_t scope;
 308        union sctp_addr *baddr = NULL;
 309        __u8 matchlen = 0;
 310        __u8 bmatchlen;
 311
 312        SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p daddr:%pI6 ",
 313                          __func__, asoc, dst, &daddr->v6.sin6_addr);
 314
 315        if (!asoc) {
 316                ipv6_dev_get_saddr(sock_net(sctp_opt2sk(sk)),
 317                                   dst ? ip6_dst_idev(dst)->dev : NULL,
 318                                   &daddr->v6.sin6_addr,
 319                                   inet6_sk(&sk->inet.sk)->srcprefs,
 320                                   &saddr->v6.sin6_addr);
 321                SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: %pI6\n",
 322                                  &saddr->v6.sin6_addr);
 323                return;
 324        }
 325
 326        scope = sctp_scope(daddr);
 327
 328        bp = &asoc->base.bind_addr;
 329
 330        /* Go through the bind address list and find the best source address
 331         * that matches the scope of the destination address.
 332         */
 333        rcu_read_lock();
 334        list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 335                if (!laddr->valid)
 336                        continue;
 337                if ((laddr->state == SCTP_ADDR_SRC) &&
 338                    (laddr->a.sa.sa_family == AF_INET6) &&
 339                    (scope <= sctp_scope(&laddr->a))) {
 340                        bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 341                        if (!baddr || (matchlen < bmatchlen)) {
 342                                baddr = &laddr->a;
 343                                matchlen = bmatchlen;
 344                        }
 345                }
 346        }
 347
 348        if (baddr) {
 349                memcpy(saddr, baddr, sizeof(union sctp_addr));
 350                SCTP_DEBUG_PRINTK("saddr: %pI6\n", &saddr->v6.sin6_addr);
 351        } else {
 352                printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 353                       "address for the dest:%pI6\n",
 354                       __func__, asoc, &daddr->v6.sin6_addr);
 355        }
 356
 357        rcu_read_unlock();
 358}
 359
 360/* Make a copy of all potential local addresses. */
 361static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 362                                  struct net_device *dev)
 363{
 364        struct inet6_dev *in6_dev;
 365        struct inet6_ifaddr *ifp;
 366        struct sctp_sockaddr_entry *addr;
 367
 368        rcu_read_lock();
 369        if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 370                rcu_read_unlock();
 371                return;
 372        }
 373
 374        read_lock_bh(&in6_dev->lock);
 375        for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 376                /* Add the address to the local list.  */
 377                addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 378                if (addr) {
 379                        addr->a.v6.sin6_family = AF_INET6;
 380                        addr->a.v6.sin6_port = 0;
 381                        addr->a.v6.sin6_addr = ifp->addr;
 382                        addr->a.v6.sin6_scope_id = dev->ifindex;
 383                        addr->valid = 1;
 384                        INIT_LIST_HEAD(&addr->list);
 385                        INIT_RCU_HEAD(&addr->rcu);
 386                        list_add_tail(&addr->list, addrlist);
 387                }
 388        }
 389
 390        read_unlock_bh(&in6_dev->lock);
 391        rcu_read_unlock();
 392}
 393
 394/* Initialize a sockaddr_storage from in incoming skb. */
 395static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 396                             int is_saddr)
 397{
 398        void *from;
 399        __be16 *port;
 400        struct sctphdr *sh;
 401
 402        port = &addr->v6.sin6_port;
 403        addr->v6.sin6_family = AF_INET6;
 404        addr->v6.sin6_flowinfo = 0; /* FIXME */
 405        addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 406
 407        sh = sctp_hdr(skb);
 408        if (is_saddr) {
 409                *port  = sh->source;
 410                from = &ipv6_hdr(skb)->saddr;
 411        } else {
 412                *port = sh->dest;
 413                from = &ipv6_hdr(skb)->daddr;
 414        }
 415        ipv6_addr_copy(&addr->v6.sin6_addr, from);
 416}
 417
 418/* Initialize an sctp_addr from a socket. */
 419static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 420{
 421        addr->v6.sin6_family = AF_INET6;
 422        addr->v6.sin6_port = 0;
 423        addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 424}
 425
 426/* Initialize sk->sk_rcv_saddr from sctp_addr. */
 427static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 428{
 429        if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 430                inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 431                inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 432                inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 433                inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 434                        addr->v4.sin_addr.s_addr;
 435        } else {
 436                inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 437        }
 438}
 439
 440/* Initialize sk->sk_daddr from sctp_addr. */
 441static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 442{
 443        if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 444                inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 445                inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 446                inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 447                inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 448        } else {
 449                inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 450        }
 451}
 452
 453/* Initialize a sctp_addr from an address parameter. */
 454static void sctp_v6_from_addr_param(union sctp_addr *addr,
 455                                    union sctp_addr_param *param,
 456                                    __be16 port, int iif)
 457{
 458        addr->v6.sin6_family = AF_INET6;
 459        addr->v6.sin6_port = port;
 460        addr->v6.sin6_flowinfo = 0; /* BUG */
 461        ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 462        addr->v6.sin6_scope_id = iif;
 463}
 464
 465/* Initialize an address parameter from a sctp_addr and return the length
 466 * of the address parameter.
 467 */
 468static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 469                                 union sctp_addr_param *param)
 470{
 471        int length = sizeof(sctp_ipv6addr_param_t);
 472
 473        param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 474        param->v6.param_hdr.length = htons(length);
 475        ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 476
 477        return length;
 478}
 479
 480/* Initialize a sctp_addr from a dst_entry. */
 481static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 482                              __be16 port)
 483{
 484        struct rt6_info *rt = (struct rt6_info *)dst;
 485        addr->sa.sa_family = AF_INET6;
 486        addr->v6.sin6_port = port;
 487        ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 488}
 489
 490/* Compare addresses exactly.
 491 * v4-mapped-v6 is also in consideration.
 492 */
 493static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 494                            const union sctp_addr *addr2)
 495{
 496        if (addr1->sa.sa_family != addr2->sa.sa_family) {
 497                if (addr1->sa.sa_family == AF_INET &&
 498                    addr2->sa.sa_family == AF_INET6 &&
 499                    ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 500                        if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 501                            addr2->v6.sin6_addr.s6_addr32[3] ==
 502                            addr1->v4.sin_addr.s_addr)
 503                                return 1;
 504                }
 505                if (addr2->sa.sa_family == AF_INET &&
 506                    addr1->sa.sa_family == AF_INET6 &&
 507                    ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 508                        if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 509                            addr1->v6.sin6_addr.s6_addr32[3] ==
 510                            addr2->v4.sin_addr.s_addr)
 511                                return 1;
 512                }
 513                return 0;
 514        }
 515        if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 516                return 0;
 517        /* If this is a linklocal address, compare the scope_id. */
 518        if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 519                if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 520                    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 521                        return 0;
 522                }
 523        }
 524
 525        return 1;
 526}
 527
 528/* Initialize addr struct to INADDR_ANY. */
 529static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 530{
 531        memset(addr, 0x00, sizeof(union sctp_addr));
 532        addr->v6.sin6_family = AF_INET6;
 533        addr->v6.sin6_port = port;
 534}
 535
 536/* Is this a wildcard address? */
 537static int sctp_v6_is_any(const union sctp_addr *addr)
 538{
 539        return ipv6_addr_any(&addr->v6.sin6_addr);
 540}
 541
 542/* Should this be available for binding?   */
 543static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 544{
 545        int type;
 546        struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 547
 548        type = ipv6_addr_type(in6);
 549        if (IPV6_ADDR_ANY == type)
 550                return 1;
 551        if (type == IPV6_ADDR_MAPPED) {
 552                if (sp && !sp->v4mapped)
 553                        return 0;
 554                if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 555                        return 0;
 556                sctp_v6_map_v4(addr);
 557                return sctp_get_af_specific(AF_INET)->available(addr, sp);
 558        }
 559        if (!(type & IPV6_ADDR_UNICAST))
 560                return 0;
 561
 562        return ipv6_chk_addr(&init_net, in6, NULL, 0);
 563}
 564
 565/* This function checks if the address is a valid address to be used for
 566 * SCTP.
 567 *
 568 * Output:
 569 * Return 0 - If the address is a non-unicast or an illegal address.
 570 * Return 1 - If the address is a unicast.
 571 */
 572static int sctp_v6_addr_valid(union sctp_addr *addr,
 573                              struct sctp_sock *sp,
 574                              const struct sk_buff *skb)
 575{
 576        int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 577
 578        /* Support v4-mapped-v6 address. */
 579        if (ret == IPV6_ADDR_MAPPED) {
 580                /* Note: This routine is used in input, so v4-mapped-v6
 581                 * are disallowed here when there is no sctp_sock.
 582                 */
 583                if (!sp || !sp->v4mapped)
 584                        return 0;
 585                if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 586                        return 0;
 587                sctp_v6_map_v4(addr);
 588                return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 589        }
 590
 591        /* Is this a non-unicast address */
 592        if (!(ret & IPV6_ADDR_UNICAST))
 593                return 0;
 594
 595        return 1;
 596}
 597
 598/* What is the scope of 'addr'?  */
 599static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 600{
 601        int v6scope;
 602        sctp_scope_t retval;
 603
 604        /* The IPv6 scope is really a set of bit fields.
 605         * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 606         */
 607
 608        v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 609        switch (v6scope) {
 610        case IFA_HOST:
 611                retval = SCTP_SCOPE_LOOPBACK;
 612                break;
 613        case IFA_LINK:
 614                retval = SCTP_SCOPE_LINK;
 615                break;
 616        case IFA_SITE:
 617                retval = SCTP_SCOPE_PRIVATE;
 618                break;
 619        default:
 620                retval = SCTP_SCOPE_GLOBAL;
 621                break;
 622        }
 623
 624        return retval;
 625}
 626
 627/* Create and initialize a new sk for the socket to be returned by accept(). */
 628static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 629                                             struct sctp_association *asoc)
 630{
 631        struct inet_sock *inet = inet_sk(sk);
 632        struct sock *newsk;
 633        struct inet_sock *newinet;
 634        struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 635        struct sctp6_sock *newsctp6sk;
 636
 637        newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 638        if (!newsk)
 639                goto out;
 640
 641        sock_init_data(NULL, newsk);
 642
 643        newsk->sk_type = SOCK_STREAM;
 644
 645        newsk->sk_prot = sk->sk_prot;
 646        newsk->sk_no_check = sk->sk_no_check;
 647        newsk->sk_reuse = sk->sk_reuse;
 648
 649        newsk->sk_destruct = inet_sock_destruct;
 650        newsk->sk_family = PF_INET6;
 651        newsk->sk_protocol = IPPROTO_SCTP;
 652        newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 653        newsk->sk_shutdown = sk->sk_shutdown;
 654        sock_reset_flag(sk, SOCK_ZAPPED);
 655
 656        newsctp6sk = (struct sctp6_sock *)newsk;
 657        inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 658
 659        sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 660
 661        newinet = inet_sk(newsk);
 662        newnp = inet6_sk(newsk);
 663
 664        memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 665
 666        /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 667         * and getpeername().
 668         */
 669        newinet->sport = inet->sport;
 670        newnp->saddr = np->saddr;
 671        newnp->rcv_saddr = np->rcv_saddr;
 672        newinet->dport = htons(asoc->peer.port);
 673        sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 674
 675        /* Init the ipv4 part of the socket since we can have sockets
 676         * using v6 API for ipv4.
 677         */
 678        newinet->uc_ttl = -1;
 679        newinet->mc_loop = 1;
 680        newinet->mc_ttl = 1;
 681        newinet->mc_index = 0;
 682        newinet->mc_list = NULL;
 683
 684        if (ipv4_config.no_pmtu_disc)
 685                newinet->pmtudisc = IP_PMTUDISC_DONT;
 686        else
 687                newinet->pmtudisc = IP_PMTUDISC_WANT;
 688
 689        sk_refcnt_debug_inc(newsk);
 690
 691        if (newsk->sk_prot->init(newsk)) {
 692                sk_common_release(newsk);
 693                newsk = NULL;
 694        }
 695
 696out:
 697        return newsk;
 698}
 699
 700/* Map v4 address to mapped v6 address */
 701static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 702{
 703        if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 704                sctp_v4_map_v6(addr);
 705}
 706
 707/* Where did this skb come from?  */
 708static int sctp_v6_skb_iif(const struct sk_buff *skb)
 709{
 710        struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 711        return opt->iif;
 712}
 713
 714/* Was this packet marked by Explicit Congestion Notification? */
 715static int sctp_v6_is_ce(const struct sk_buff *skb)
 716{
 717        return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 718}
 719
 720/* Dump the v6 addr to the seq file. */
 721static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 722{
 723        seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 724}
 725
 726static void sctp_v6_ecn_capable(struct sock *sk)
 727{
 728        inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 729}
 730
 731/* Initialize a PF_INET6 socket msg_name. */
 732static void sctp_inet6_msgname(char *msgname, int *addr_len)
 733{
 734        struct sockaddr_in6 *sin6;
 735
 736        sin6 = (struct sockaddr_in6 *)msgname;
 737        sin6->sin6_family = AF_INET6;
 738        sin6->sin6_flowinfo = 0;
 739        sin6->sin6_scope_id = 0; /*FIXME */
 740        *addr_len = sizeof(struct sockaddr_in6);
 741}
 742
 743/* Initialize a PF_INET msgname from a ulpevent. */
 744static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 745                                     char *msgname, int *addrlen)
 746{
 747        struct sockaddr_in6 *sin6, *sin6from;
 748
 749        if (msgname) {
 750                union sctp_addr *addr;
 751                struct sctp_association *asoc;
 752
 753                asoc = event->asoc;
 754                sctp_inet6_msgname(msgname, addrlen);
 755                sin6 = (struct sockaddr_in6 *)msgname;
 756                sin6->sin6_port = htons(asoc->peer.port);
 757                addr = &asoc->peer.primary_addr;
 758
 759                /* Note: If we go to a common v6 format, this code
 760                 * will change.
 761                 */
 762
 763                /* Map ipv4 address into v4-mapped-on-v6 address.  */
 764                if (sctp_sk(asoc->base.sk)->v4mapped &&
 765                    AF_INET == addr->sa.sa_family) {
 766                        sctp_v4_map_v6((union sctp_addr *)sin6);
 767                        sin6->sin6_addr.s6_addr32[3] =
 768                                addr->v4.sin_addr.s_addr;
 769                        return;
 770                }
 771
 772                sin6from = &asoc->peer.primary_addr.v6;
 773                ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 774                if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 775                        sin6->sin6_scope_id = sin6from->sin6_scope_id;
 776        }
 777}
 778
 779/* Initialize a msg_name from an inbound skb. */
 780static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 781                                   int *addr_len)
 782{
 783        struct sctphdr *sh;
 784        struct sockaddr_in6 *sin6;
 785
 786        if (msgname) {
 787                sctp_inet6_msgname(msgname, addr_len);
 788                sin6 = (struct sockaddr_in6 *)msgname;
 789                sh = sctp_hdr(skb);
 790                sin6->sin6_port = sh->source;
 791
 792                /* Map ipv4 address into v4-mapped-on-v6 address. */
 793                if (sctp_sk(skb->sk)->v4mapped &&
 794                    ip_hdr(skb)->version == 4) {
 795                        sctp_v4_map_v6((union sctp_addr *)sin6);
 796                        sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 797                        return;
 798                }
 799
 800                /* Otherwise, just copy the v6 address. */
 801                ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
 802                if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 803                        struct sctp_ulpevent *ev = sctp_skb2event(skb);
 804                        sin6->sin6_scope_id = ev->iif;
 805                }
 806        }
 807}
 808
 809/* Do we support this AF? */
 810static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 811{
 812        switch (family) {
 813        case AF_INET6:
 814                return 1;
 815        /* v4-mapped-v6 addresses */
 816        case AF_INET:
 817                if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 818                        return 1;
 819        default:
 820                return 0;
 821        }
 822}
 823
 824/* Address matching with wildcards allowed.  This extra level
 825 * of indirection lets us choose whether a PF_INET6 should
 826 * disallow any v4 addresses if we so choose.
 827 */
 828static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 829                               const union sctp_addr *addr2,
 830                               struct sctp_sock *opt)
 831{
 832        struct sctp_af *af1, *af2;
 833        struct sock *sk = sctp_opt2sk(opt);
 834
 835        af1 = sctp_get_af_specific(addr1->sa.sa_family);
 836        af2 = sctp_get_af_specific(addr2->sa.sa_family);
 837
 838        if (!af1 || !af2)
 839                return 0;
 840
 841        /* If the socket is IPv6 only, v4 addrs will not match */
 842        if (__ipv6_only_sock(sk) && af1 != af2)
 843                return 0;
 844
 845        /* Today, wildcard AF_INET/AF_INET6. */
 846        if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 847                return 1;
 848
 849        if (addr1->sa.sa_family != addr2->sa.sa_family)
 850                return 0;
 851
 852        return af1->cmp_addr(addr1, addr2);
 853}
 854
 855/* Verify that the provided sockaddr looks bindable.   Common verification,
 856 * has already been taken care of.
 857 */
 858static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 859{
 860        struct sctp_af *af;
 861
 862        /* ASSERT: address family has already been verified. */
 863        if (addr->sa.sa_family != AF_INET6)
 864                af = sctp_get_af_specific(addr->sa.sa_family);
 865        else {
 866                int type = ipv6_addr_type(&addr->v6.sin6_addr);
 867                struct net_device *dev;
 868
 869                if (type & IPV6_ADDR_LINKLOCAL) {
 870                        if (!addr->v6.sin6_scope_id)
 871                                return 0;
 872                        dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 873                        if (!dev)
 874                                return 0;
 875                        if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
 876                                           dev, 0)) {
 877                                dev_put(dev);
 878                                return 0;
 879                        }
 880                        dev_put(dev);
 881                } else if (type == IPV6_ADDR_MAPPED) {
 882                        if (!opt->v4mapped)
 883                                return 0;
 884                }
 885
 886                af = opt->pf->af;
 887        }
 888        return af->available(addr, opt);
 889}
 890
 891/* Verify that the provided sockaddr looks sendable.   Common verification,
 892 * has already been taken care of.
 893 */
 894static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 895{
 896        struct sctp_af *af = NULL;
 897
 898        /* ASSERT: address family has already been verified. */
 899        if (addr->sa.sa_family != AF_INET6)
 900                af = sctp_get_af_specific(addr->sa.sa_family);
 901        else {
 902                int type = ipv6_addr_type(&addr->v6.sin6_addr);
 903                struct net_device *dev;
 904
 905                if (type & IPV6_ADDR_LINKLOCAL) {
 906                        if (!addr->v6.sin6_scope_id)
 907                                return 0;
 908                        dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
 909                        if (!dev)
 910                                return 0;
 911                        dev_put(dev);
 912                }
 913                af = opt->pf->af;
 914        }
 915
 916        return af != NULL;
 917}
 918
 919/* Fill in Supported Address Type information for INIT and INIT-ACK
 920 * chunks.   Note: In the future, we may want to look at sock options
 921 * to determine whether a PF_INET6 socket really wants to have IPV4
 922 * addresses.
 923 * Returns number of addresses supported.
 924 */
 925static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 926                                      __be16 *types)
 927{
 928        types[0] = SCTP_PARAM_IPV6_ADDRESS;
 929        if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 930                types[1] = SCTP_PARAM_IPV4_ADDRESS;
 931                return 2;
 932        }
 933        return 1;
 934}
 935
 936static const struct proto_ops inet6_seqpacket_ops = {
 937        .family            = PF_INET6,
 938        .owner             = THIS_MODULE,
 939        .release           = inet6_release,
 940        .bind              = inet6_bind,
 941        .connect           = inet_dgram_connect,
 942        .socketpair        = sock_no_socketpair,
 943        .accept            = inet_accept,
 944        .getname           = inet6_getname,
 945        .poll              = sctp_poll,
 946        .ioctl             = inet6_ioctl,
 947        .listen            = sctp_inet_listen,
 948        .shutdown          = inet_shutdown,
 949        .setsockopt        = sock_common_setsockopt,
 950        .getsockopt        = sock_common_getsockopt,
 951        .sendmsg           = inet_sendmsg,
 952        .recvmsg           = sock_common_recvmsg,
 953        .mmap              = sock_no_mmap,
 954#ifdef CONFIG_COMPAT
 955        .compat_setsockopt = compat_sock_common_setsockopt,
 956        .compat_getsockopt = compat_sock_common_getsockopt,
 957#endif
 958};
 959
 960static struct inet_protosw sctpv6_seqpacket_protosw = {
 961        .type          = SOCK_SEQPACKET,
 962        .protocol      = IPPROTO_SCTP,
 963        .prot          = &sctpv6_prot,
 964        .ops           = &inet6_seqpacket_ops,
 965        .capability    = -1,
 966        .no_check      = 0,
 967        .flags         = SCTP_PROTOSW_FLAG
 968};
 969static struct inet_protosw sctpv6_stream_protosw = {
 970        .type          = SOCK_STREAM,
 971        .protocol      = IPPROTO_SCTP,
 972        .prot          = &sctpv6_prot,
 973        .ops           = &inet6_seqpacket_ops,
 974        .capability    = -1,
 975        .no_check      = 0,
 976        .flags         = SCTP_PROTOSW_FLAG,
 977};
 978
 979static int sctp6_rcv(struct sk_buff *skb)
 980{
 981        return sctp_rcv(skb) ? -1 : 0;
 982}
 983
 984static struct inet6_protocol sctpv6_protocol = {
 985        .handler      = sctp6_rcv,
 986        .err_handler  = sctp_v6_err,
 987        .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 988};
 989
 990static struct sctp_af sctp_af_inet6 = {
 991        .sa_family         = AF_INET6,
 992        .sctp_xmit         = sctp_v6_xmit,
 993        .setsockopt        = ipv6_setsockopt,
 994        .getsockopt        = ipv6_getsockopt,
 995        .get_dst           = sctp_v6_get_dst,
 996        .get_saddr         = sctp_v6_get_saddr,
 997        .copy_addrlist     = sctp_v6_copy_addrlist,
 998        .from_skb          = sctp_v6_from_skb,
 999        .from_sk           = sctp_v6_from_sk,
1000        .to_sk_saddr       = sctp_v6_to_sk_saddr,
1001        .to_sk_daddr       = sctp_v6_to_sk_daddr,
1002        .from_addr_param   = sctp_v6_from_addr_param,
1003        .to_addr_param     = sctp_v6_to_addr_param,
1004        .dst_saddr         = sctp_v6_dst_saddr,
1005        .cmp_addr          = sctp_v6_cmp_addr,
1006        .scope             = sctp_v6_scope,
1007        .addr_valid        = sctp_v6_addr_valid,
1008        .inaddr_any        = sctp_v6_inaddr_any,
1009        .is_any            = sctp_v6_is_any,
1010        .available         = sctp_v6_available,
1011        .skb_iif           = sctp_v6_skb_iif,
1012        .is_ce             = sctp_v6_is_ce,
1013        .seq_dump_addr     = sctp_v6_seq_dump_addr,
1014        .ecn_capable       = sctp_v6_ecn_capable,
1015        .net_header_len    = sizeof(struct ipv6hdr),
1016        .sockaddr_len      = sizeof(struct sockaddr_in6),
1017#ifdef CONFIG_COMPAT
1018        .compat_setsockopt = compat_ipv6_setsockopt,
1019        .compat_getsockopt = compat_ipv6_getsockopt,
1020#endif
1021};
1022
1023static struct sctp_pf sctp_pf_inet6 = {
1024        .event_msgname = sctp_inet6_event_msgname,
1025        .skb_msgname   = sctp_inet6_skb_msgname,
1026        .af_supported  = sctp_inet6_af_supported,
1027        .cmp_addr      = sctp_inet6_cmp_addr,
1028        .bind_verify   = sctp_inet6_bind_verify,
1029        .send_verify   = sctp_inet6_send_verify,
1030        .supported_addrs = sctp_inet6_supported_addrs,
1031        .create_accept_sk = sctp_v6_create_accept_sk,
1032        .addr_v4map    = sctp_v6_addr_v4map,
1033        .af            = &sctp_af_inet6,
1034};
1035
1036/* Initialize IPv6 support and register with socket layer.  */
1037void sctp_v6_pf_init(void)
1038{
1039        /* Register the SCTP specific PF_INET6 functions. */
1040        sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1041
1042        /* Register the SCTP specific AF_INET6 functions. */
1043        sctp_register_af(&sctp_af_inet6);
1044}
1045
1046void sctp_v6_pf_exit(void)
1047{
1048        list_del(&sctp_af_inet6.list);
1049}
1050
1051/* Initialize IPv6 support and register with socket layer.  */
1052int sctp_v6_protosw_init(void)
1053{
1054        int rc;
1055
1056        rc = proto_register(&sctpv6_prot, 1);
1057        if (rc)
1058                return rc;
1059
1060        /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1061        inet6_register_protosw(&sctpv6_seqpacket_protosw);
1062        inet6_register_protosw(&sctpv6_stream_protosw);
1063
1064        return 0;
1065}
1066
1067void sctp_v6_protosw_exit(void)
1068{
1069        inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1070        inet6_unregister_protosw(&sctpv6_stream_protosw);
1071        proto_unregister(&sctpv6_prot);
1072}
1073
1074
1075/* Register with inet6 layer. */
1076int sctp_v6_add_protocol(void)
1077{
1078        /* Register notifier for inet6 address additions/deletions. */
1079        register_inet6addr_notifier(&sctp_inet6addr_notifier);
1080
1081        if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1082                return -EAGAIN;
1083
1084        return 0;
1085}
1086
1087/* Unregister with inet6 layer. */
1088void sctp_v6_del_protocol(void)
1089{
1090        inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1091        unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1092}
1093