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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  51
  52#include <linux/module.h>
  53#include <linux/errno.h>
  54#include <linux/types.h>
  55#include <linux/socket.h>
  56#include <linux/sockios.h>
  57#include <linux/net.h>
  58#include <linux/in.h>
  59#include <linux/in6.h>
  60#include <linux/netdevice.h>
  61#include <linux/init.h>
  62#include <linux/ipsec.h>
  63#include <linux/slab.h>
  64
  65#include <linux/ipv6.h>
  66#include <linux/icmpv6.h>
  67#include <linux/random.h>
  68#include <linux/seq_file.h>
  69
  70#include <net/protocol.h>
  71#include <net/ndisc.h>
  72#include <net/ip.h>
  73#include <net/ipv6.h>
  74#include <net/transp_v6.h>
  75#include <net/addrconf.h>
  76#include <net/ip6_route.h>
  77#include <net/inet_common.h>
  78#include <net/inet_ecn.h>
  79#include <net/sctp/sctp.h>
  80
  81#include <asm/uaccess.h>
  82
  83static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  84                                         union sctp_addr *s2);
  85static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  86                              __be16 port);
  87static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  88                            const union sctp_addr *addr2);
  89
  90/* Event handler for inet6 address addition/deletion events.
  91 * The sctp_local_addr_list needs to be protocted by a spin lock since
  92 * multiple notifiers (say IPv4 and IPv6) may be running at the same
  93 * time and thus corrupt the list.
  94 * The reader side is protected with RCU.
  95 */
  96static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  97                                void *ptr)
  98{
  99        struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
 100        struct sctp_sockaddr_entry *addr = NULL;
 101        struct sctp_sockaddr_entry *temp;
 102        struct net *net = dev_net(ifa->idev->dev);
 103        int found = 0;
 104
 105        switch (ev) {
 106        case NETDEV_UP:
 107                addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 108                if (addr) {
 109                        addr->a.v6.sin6_family = AF_INET6;
 110                        addr->a.v6.sin6_port = 0;
 111                        addr->a.v6.sin6_addr = ifa->addr;
 112                        addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 113                        addr->valid = 1;
 114                        spin_lock_bh(&net->sctp.local_addr_lock);
 115                        list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 116                        sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 117                        spin_unlock_bh(&net->sctp.local_addr_lock);
 118                }
 119                break;
 120        case NETDEV_DOWN:
 121                spin_lock_bh(&net->sctp.local_addr_lock);
 122                list_for_each_entry_safe(addr, temp,
 123                                        &net->sctp.local_addr_list, list) {
 124                        if (addr->a.sa.sa_family == AF_INET6 &&
 125                                        ipv6_addr_equal(&addr->a.v6.sin6_addr,
 126                                                &ifa->addr)) {
 127                                sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 128                                found = 1;
 129                                addr->valid = 0;
 130                                list_del_rcu(&addr->list);
 131                                break;
 132                        }
 133                }
 134                spin_unlock_bh(&net->sctp.local_addr_lock);
 135                if (found)
 136                        kfree_rcu(addr, rcu);
 137                break;
 138        }
 139
 140        return NOTIFY_DONE;
 141}
 142
 143static struct notifier_block sctp_inet6addr_notifier = {
 144        .notifier_call = sctp_inet6addr_event,
 145};
 146
 147/* ICMP error handler. */
 148SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 149                             u8 type, u8 code, int offset, __be32 info)
 150{
 151        struct inet6_dev *idev;
 152        struct sock *sk;
 153        struct sctp_association *asoc;
 154        struct sctp_transport *transport;
 155        struct ipv6_pinfo *np;
 156        sk_buff_data_t saveip, savesctp;
 157        int err;
 158        struct net *net = dev_net(skb->dev);
 159
 160        idev = in6_dev_get(skb->dev);
 161
 162        /* Fix up skb to look at the embedded net header. */
 163        saveip   = skb->network_header;
 164        savesctp = skb->transport_header;
 165        skb_reset_network_header(skb);
 166        skb_set_transport_header(skb, offset);
 167        sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 168        /* Put back, the original pointers. */
 169        skb->network_header   = saveip;
 170        skb->transport_header = savesctp;
 171        if (!sk) {
 172                ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_INERRORS);
 173                goto out;
 174        }
 175
 176        /* Warning:  The sock lock is held.  Remember to call
 177         * sctp_err_finish!
 178         */
 179
 180        switch (type) {
 181        case ICMPV6_PKT_TOOBIG:
 182                sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 183                goto out_unlock;
 184        case ICMPV6_PARAMPROB:
 185                if (ICMPV6_UNK_NEXTHDR == code) {
 186                        sctp_icmp_proto_unreachable(sk, asoc, transport);
 187                        goto out_unlock;
 188                }
 189                break;
 190        case NDISC_REDIRECT:
 191                sctp_icmp_redirect(sk, transport, skb);
 192                break;
 193        default:
 194                break;
 195        }
 196
 197        np = inet6_sk(sk);
 198        icmpv6_err_convert(type, code, &err);
 199        if (!sock_owned_by_user(sk) && np->recverr) {
 200                sk->sk_err = err;
 201                sk->sk_error_report(sk);
 202        } else {  /* Only an error on timeout */
 203                sk->sk_err_soft = err;
 204        }
 205
 206out_unlock:
 207        sctp_err_finish(sk, asoc);
 208out:
 209        if (likely(idev != NULL))
 210                in6_dev_put(idev);
 211}
 212
 213/* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 214static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 215{
 216        struct sock *sk = skb->sk;
 217        struct ipv6_pinfo *np = inet6_sk(sk);
 218        struct flowi6 fl6;
 219
 220        memset(&fl6, 0, sizeof(fl6));
 221
 222        fl6.flowi6_proto = sk->sk_protocol;
 223
 224        /* Fill in the dest address from the route entry passed with the skb
 225         * and the source address from the transport.
 226         */
 227        fl6.daddr = transport->ipaddr.v6.sin6_addr;
 228        fl6.saddr = transport->saddr.v6.sin6_addr;
 229
 230        fl6.flowlabel = np->flow_label;
 231        IP6_ECN_flow_xmit(sk, fl6.flowlabel);
 232        if (ipv6_addr_type(&fl6.saddr) & IPV6_ADDR_LINKLOCAL)
 233                fl6.flowi6_oif = transport->saddr.v6.sin6_scope_id;
 234        else
 235                fl6.flowi6_oif = sk->sk_bound_dev_if;
 236
 237        if (np->opt && np->opt->srcrt) {
 238                struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 239                fl6.daddr = *rt0->addr;
 240        }
 241
 242        SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
 243                          __func__, skb, skb->len,
 244                          &fl6.saddr, &fl6.daddr);
 245
 246        SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 247
 248        if (!(transport->param_flags & SPP_PMTUD_ENABLE))
 249                skb->local_df = 1;
 250
 251        return ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 252}
 253
 254/* Returns the dst cache entry for the given source and destination ip
 255 * addresses.
 256 */
 257static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 258                            struct flowi *fl, struct sock *sk)
 259{
 260        struct sctp_association *asoc = t->asoc;
 261        struct dst_entry *dst = NULL;
 262        struct flowi6 *fl6 = &fl->u.ip6;
 263        struct sctp_bind_addr *bp;
 264        struct sctp_sockaddr_entry *laddr;
 265        union sctp_addr *baddr = NULL;
 266        union sctp_addr *daddr = &t->ipaddr;
 267        union sctp_addr dst_saddr;
 268        __u8 matchlen = 0;
 269        __u8 bmatchlen;
 270        sctp_scope_t scope;
 271
 272        memset(fl6, 0, sizeof(struct flowi6));
 273        fl6->daddr = daddr->v6.sin6_addr;
 274        fl6->fl6_dport = daddr->v6.sin6_port;
 275        fl6->flowi6_proto = IPPROTO_SCTP;
 276        if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 277                fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 278
 279        SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 280
 281        if (asoc)
 282                fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 283
 284        if (saddr) {
 285                fl6->saddr = saddr->v6.sin6_addr;
 286                fl6->fl6_sport = saddr->v6.sin6_port;
 287                SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
 288        }
 289
 290        dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 291        if (!asoc || saddr)
 292                goto out;
 293
 294        bp = &asoc->base.bind_addr;
 295        scope = sctp_scope(daddr);
 296        /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 297         * to see if we can use it.
 298         */
 299        if (!IS_ERR(dst)) {
 300                /* Walk through the bind address list and look for a bind
 301                 * address that matches the source address of the returned dst.
 302                 */
 303                sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 304                rcu_read_lock();
 305                list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 306                        if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
 307                                continue;
 308
 309                        /* Do not compare against v4 addrs */
 310                        if ((laddr->a.sa.sa_family == AF_INET6) &&
 311                            (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 312                                rcu_read_unlock();
 313                                goto out;
 314                        }
 315                }
 316                rcu_read_unlock();
 317                /* None of the bound addresses match the source address of the
 318                 * dst. So release it.
 319                 */
 320                dst_release(dst);
 321                dst = NULL;
 322        }
 323
 324        /* Walk through the bind address list and try to get the
 325         * best source address for a given destination.
 326         */
 327        rcu_read_lock();
 328        list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 329                if (!laddr->valid)
 330                        continue;
 331                if ((laddr->state == SCTP_ADDR_SRC) &&
 332                    (laddr->a.sa.sa_family == AF_INET6) &&
 333                    (scope <= sctp_scope(&laddr->a))) {
 334                        bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 335                        if (!baddr || (matchlen < bmatchlen)) {
 336                                baddr = &laddr->a;
 337                                matchlen = bmatchlen;
 338                        }
 339                }
 340        }
 341        rcu_read_unlock();
 342        if (baddr) {
 343                fl6->saddr = baddr->v6.sin6_addr;
 344                fl6->fl6_sport = baddr->v6.sin6_port;
 345                dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
 346        }
 347
 348out:
 349        if (!IS_ERR_OR_NULL(dst)) {
 350                struct rt6_info *rt;
 351                rt = (struct rt6_info *)dst;
 352                t->dst = dst;
 353                SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
 354                        &rt->rt6i_dst.addr, &fl6->saddr);
 355        } else {
 356                t->dst = NULL;
 357                SCTP_DEBUG_PRINTK("NO ROUTE\n");
 358        }
 359}
 360
 361/* Returns the number of consecutive initial bits that match in the 2 ipv6
 362 * addresses.
 363 */
 364static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 365                                         union sctp_addr *s2)
 366{
 367        return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 368}
 369
 370/* Fills in the source address(saddr) based on the destination address(daddr)
 371 * and asoc's bind address list.
 372 */
 373static void sctp_v6_get_saddr(struct sctp_sock *sk,
 374                              struct sctp_transport *t,
 375                              struct flowi *fl)
 376{
 377        struct flowi6 *fl6 = &fl->u.ip6;
 378        union sctp_addr *saddr = &t->saddr;
 379
 380        SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 381
 382        if (t->dst) {
 383                saddr->v6.sin6_family = AF_INET6;
 384                saddr->v6.sin6_addr = fl6->saddr;
 385        }
 386}
 387
 388/* Make a copy of all potential local addresses. */
 389static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 390                                  struct net_device *dev)
 391{
 392        struct inet6_dev *in6_dev;
 393        struct inet6_ifaddr *ifp;
 394        struct sctp_sockaddr_entry *addr;
 395
 396        rcu_read_lock();
 397        if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 398                rcu_read_unlock();
 399                return;
 400        }
 401
 402        read_lock_bh(&in6_dev->lock);
 403        list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 404                /* Add the address to the local list.  */
 405                addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 406                if (addr) {
 407                        addr->a.v6.sin6_family = AF_INET6;
 408                        addr->a.v6.sin6_port = 0;
 409                        addr->a.v6.sin6_addr = ifp->addr;
 410                        addr->a.v6.sin6_scope_id = dev->ifindex;
 411                        addr->valid = 1;
 412                        INIT_LIST_HEAD(&addr->list);
 413                        list_add_tail(&addr->list, addrlist);
 414                }
 415        }
 416
 417        read_unlock_bh(&in6_dev->lock);
 418        rcu_read_unlock();
 419}
 420
 421/* Initialize a sockaddr_storage from in incoming skb. */
 422static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 423                             int is_saddr)
 424{
 425        __be16 *port;
 426        struct sctphdr *sh;
 427
 428        port = &addr->v6.sin6_port;
 429        addr->v6.sin6_family = AF_INET6;
 430        addr->v6.sin6_flowinfo = 0; /* FIXME */
 431        addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 432
 433        sh = sctp_hdr(skb);
 434        if (is_saddr) {
 435                *port  = sh->source;
 436                addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 437        } else {
 438                *port = sh->dest;
 439                addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
 440        }
 441}
 442
 443/* Initialize an sctp_addr from a socket. */
 444static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 445{
 446        addr->v6.sin6_family = AF_INET6;
 447        addr->v6.sin6_port = 0;
 448        addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 449}
 450
 451/* Initialize sk->sk_rcv_saddr from sctp_addr. */
 452static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 453{
 454        if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 455                inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 456                inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 457                inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 458                inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 459                        addr->v4.sin_addr.s_addr;
 460        } else {
 461                inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 462        }
 463}
 464
 465/* Initialize sk->sk_daddr from sctp_addr. */
 466static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 467{
 468        if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 469                inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 470                inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 471                inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 472                inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 473        } else {
 474                inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 475        }
 476}
 477
 478/* Initialize a sctp_addr from an address parameter. */
 479static void sctp_v6_from_addr_param(union sctp_addr *addr,
 480                                    union sctp_addr_param *param,
 481                                    __be16 port, int iif)
 482{
 483        addr->v6.sin6_family = AF_INET6;
 484        addr->v6.sin6_port = port;
 485        addr->v6.sin6_flowinfo = 0; /* BUG */
 486        addr->v6.sin6_addr = param->v6.addr;
 487        addr->v6.sin6_scope_id = iif;
 488}
 489
 490/* Initialize an address parameter from a sctp_addr and return the length
 491 * of the address parameter.
 492 */
 493static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 494                                 union sctp_addr_param *param)
 495{
 496        int length = sizeof(sctp_ipv6addr_param_t);
 497
 498        param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 499        param->v6.param_hdr.length = htons(length);
 500        param->v6.addr = addr->v6.sin6_addr;
 501
 502        return length;
 503}
 504
 505/* Initialize a sctp_addr from struct in6_addr. */
 506static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 507                              __be16 port)
 508{
 509        addr->sa.sa_family = AF_INET6;
 510        addr->v6.sin6_port = port;
 511        addr->v6.sin6_addr = *saddr;
 512}
 513
 514/* Compare addresses exactly.
 515 * v4-mapped-v6 is also in consideration.
 516 */
 517static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 518                            const union sctp_addr *addr2)
 519{
 520        if (addr1->sa.sa_family != addr2->sa.sa_family) {
 521                if (addr1->sa.sa_family == AF_INET &&
 522                    addr2->sa.sa_family == AF_INET6 &&
 523                    ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
 524                        if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 525                            addr2->v6.sin6_addr.s6_addr32[3] ==
 526                            addr1->v4.sin_addr.s_addr)
 527                                return 1;
 528                }
 529                if (addr2->sa.sa_family == AF_INET &&
 530                    addr1->sa.sa_family == AF_INET6 &&
 531                    ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
 532                        if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 533                            addr1->v6.sin6_addr.s6_addr32[3] ==
 534                            addr2->v4.sin_addr.s_addr)
 535                                return 1;
 536                }
 537                return 0;
 538        }
 539        if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 540                return 0;
 541        /* If this is a linklocal address, compare the scope_id. */
 542        if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 543                if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 544                    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 545                        return 0;
 546                }
 547        }
 548
 549        return 1;
 550}
 551
 552/* Initialize addr struct to INADDR_ANY. */
 553static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 554{
 555        memset(addr, 0x00, sizeof(union sctp_addr));
 556        addr->v6.sin6_family = AF_INET6;
 557        addr->v6.sin6_port = port;
 558}
 559
 560/* Is this a wildcard address? */
 561static int sctp_v6_is_any(const union sctp_addr *addr)
 562{
 563        return ipv6_addr_any(&addr->v6.sin6_addr);
 564}
 565
 566/* Should this be available for binding?   */
 567static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 568{
 569        int type;
 570        const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 571
 572        type = ipv6_addr_type(in6);
 573        if (IPV6_ADDR_ANY == type)
 574                return 1;
 575        if (type == IPV6_ADDR_MAPPED) {
 576                if (sp && !sp->v4mapped)
 577                        return 0;
 578                if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 579                        return 0;
 580                sctp_v6_map_v4(addr);
 581                return sctp_get_af_specific(AF_INET)->available(addr, sp);
 582        }
 583        if (!(type & IPV6_ADDR_UNICAST))
 584                return 0;
 585
 586        return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
 587}
 588
 589/* This function checks if the address is a valid address to be used for
 590 * SCTP.
 591 *
 592 * Output:
 593 * Return 0 - If the address is a non-unicast or an illegal address.
 594 * Return 1 - If the address is a unicast.
 595 */
 596static int sctp_v6_addr_valid(union sctp_addr *addr,
 597                              struct sctp_sock *sp,
 598                              const struct sk_buff *skb)
 599{
 600        int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 601
 602        /* Support v4-mapped-v6 address. */
 603        if (ret == IPV6_ADDR_MAPPED) {
 604                /* Note: This routine is used in input, so v4-mapped-v6
 605                 * are disallowed here when there is no sctp_sock.
 606                 */
 607                if (!sp || !sp->v4mapped)
 608                        return 0;
 609                if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 610                        return 0;
 611                sctp_v6_map_v4(addr);
 612                return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 613        }
 614
 615        /* Is this a non-unicast address */
 616        if (!(ret & IPV6_ADDR_UNICAST))
 617                return 0;
 618
 619        return 1;
 620}
 621
 622/* What is the scope of 'addr'?  */
 623static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 624{
 625        int v6scope;
 626        sctp_scope_t retval;
 627
 628        /* The IPv6 scope is really a set of bit fields.
 629         * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 630         */
 631
 632        v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 633        switch (v6scope) {
 634        case IFA_HOST:
 635                retval = SCTP_SCOPE_LOOPBACK;
 636                break;
 637        case IFA_LINK:
 638                retval = SCTP_SCOPE_LINK;
 639                break;
 640        case IFA_SITE:
 641                retval = SCTP_SCOPE_PRIVATE;
 642                break;
 643        default:
 644                retval = SCTP_SCOPE_GLOBAL;
 645                break;
 646        }
 647
 648        return retval;
 649}
 650
 651/* Create and initialize a new sk for the socket to be returned by accept(). */
 652static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 653                                             struct sctp_association *asoc)
 654{
 655        struct sock *newsk;
 656        struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 657        struct sctp6_sock *newsctp6sk;
 658
 659        newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
 660        if (!newsk)
 661                goto out;
 662
 663        sock_init_data(NULL, newsk);
 664
 665        sctp_copy_sock(newsk, sk, asoc);
 666        sock_reset_flag(sk, SOCK_ZAPPED);
 667
 668        newsctp6sk = (struct sctp6_sock *)newsk;
 669        inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
 670
 671        sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
 672
 673        newnp = inet6_sk(newsk);
 674
 675        memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 676
 677        /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 678         * and getpeername().
 679         */
 680        sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 681
 682        sk_refcnt_debug_inc(newsk);
 683
 684        if (newsk->sk_prot->init(newsk)) {
 685                sk_common_release(newsk);
 686                newsk = NULL;
 687        }
 688
 689out:
 690        return newsk;
 691}
 692
 693/* Map v4 address to mapped v6 address */
 694static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
 695{
 696        if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 697                sctp_v4_map_v6(addr);
 698}
 699
 700/* Where did this skb come from?  */
 701static int sctp_v6_skb_iif(const struct sk_buff *skb)
 702{
 703        struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 704        return opt->iif;
 705}
 706
 707/* Was this packet marked by Explicit Congestion Notification? */
 708static int sctp_v6_is_ce(const struct sk_buff *skb)
 709{
 710        return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
 711}
 712
 713/* Dump the v6 addr to the seq file. */
 714static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 715{
 716        seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 717}
 718
 719static void sctp_v6_ecn_capable(struct sock *sk)
 720{
 721        inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 722}
 723
 724/* Initialize a PF_INET6 socket msg_name. */
 725static void sctp_inet6_msgname(char *msgname, int *addr_len)
 726{
 727        struct sockaddr_in6 *sin6;
 728
 729        sin6 = (struct sockaddr_in6 *)msgname;
 730        sin6->sin6_family = AF_INET6;
 731        sin6->sin6_flowinfo = 0;
 732        sin6->sin6_scope_id = 0; /*FIXME */
 733        *addr_len = sizeof(struct sockaddr_in6);
 734}
 735
 736/* Initialize a PF_INET msgname from a ulpevent. */
 737static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 738                                     char *msgname, int *addrlen)
 739{
 740        struct sockaddr_in6 *sin6, *sin6from;
 741
 742        if (msgname) {
 743                union sctp_addr *addr;
 744                struct sctp_association *asoc;
 745
 746                asoc = event->asoc;
 747                sctp_inet6_msgname(msgname, addrlen);
 748                sin6 = (struct sockaddr_in6 *)msgname;
 749                sin6->sin6_port = htons(asoc->peer.port);
 750                addr = &asoc->peer.primary_addr;
 751
 752                /* Note: If we go to a common v6 format, this code
 753                 * will change.
 754                 */
 755
 756                /* Map ipv4 address into v4-mapped-on-v6 address.  */
 757                if (sctp_sk(asoc->base.sk)->v4mapped &&
 758                    AF_INET == addr->sa.sa_family) {
 759                        sctp_v4_map_v6((union sctp_addr *)sin6);
 760                        sin6->sin6_addr.s6_addr32[3] =
 761                                addr->v4.sin_addr.s_addr;
 762                        return;
 763                }
 764
 765                sin6from = &asoc->peer.primary_addr.v6;
 766                sin6->sin6_addr = sin6from->sin6_addr;
 767                if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 768                        sin6->sin6_scope_id = sin6from->sin6_scope_id;
 769        }
 770}
 771
 772/* Initialize a msg_name from an inbound skb. */
 773static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 774                                   int *addr_len)
 775{
 776        struct sctphdr *sh;
 777        struct sockaddr_in6 *sin6;
 778
 779        if (msgname) {
 780                sctp_inet6_msgname(msgname, addr_len);
 781                sin6 = (struct sockaddr_in6 *)msgname;
 782                sh = sctp_hdr(skb);
 783                sin6->sin6_port = sh->source;
 784
 785                /* Map ipv4 address into v4-mapped-on-v6 address. */
 786                if (sctp_sk(skb->sk)->v4mapped &&
 787                    ip_hdr(skb)->version == 4) {
 788                        sctp_v4_map_v6((union sctp_addr *)sin6);
 789                        sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
 790                        return;
 791                }
 792
 793                /* Otherwise, just copy the v6 address. */
 794                sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 795                if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 796                        struct sctp_ulpevent *ev = sctp_skb2event(skb);
 797                        sin6->sin6_scope_id = ev->iif;
 798                }
 799        }
 800}
 801
 802/* Do we support this AF? */
 803static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 804{
 805        switch (family) {
 806        case AF_INET6:
 807                return 1;
 808        /* v4-mapped-v6 addresses */
 809        case AF_INET:
 810                if (!__ipv6_only_sock(sctp_opt2sk(sp)))
 811                        return 1;
 812        default:
 813                return 0;
 814        }
 815}
 816
 817/* Address matching with wildcards allowed.  This extra level
 818 * of indirection lets us choose whether a PF_INET6 should
 819 * disallow any v4 addresses if we so choose.
 820 */
 821static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 822                               const union sctp_addr *addr2,
 823                               struct sctp_sock *opt)
 824{
 825        struct sctp_af *af1, *af2;
 826        struct sock *sk = sctp_opt2sk(opt);
 827
 828        af1 = sctp_get_af_specific(addr1->sa.sa_family);
 829        af2 = sctp_get_af_specific(addr2->sa.sa_family);
 830
 831        if (!af1 || !af2)
 832                return 0;
 833
 834        /* If the socket is IPv6 only, v4 addrs will not match */
 835        if (__ipv6_only_sock(sk) && af1 != af2)
 836                return 0;
 837
 838        /* Today, wildcard AF_INET/AF_INET6. */
 839        if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 840                return 1;
 841
 842        if (addr1->sa.sa_family != addr2->sa.sa_family)
 843                return 0;
 844
 845        return af1->cmp_addr(addr1, addr2);
 846}
 847
 848/* Verify that the provided sockaddr looks bindable.   Common verification,
 849 * has already been taken care of.
 850 */
 851static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 852{
 853        struct sctp_af *af;
 854
 855        /* ASSERT: address family has already been verified. */
 856        if (addr->sa.sa_family != AF_INET6)
 857                af = sctp_get_af_specific(addr->sa.sa_family);
 858        else {
 859                int type = ipv6_addr_type(&addr->v6.sin6_addr);
 860                struct net_device *dev;
 861
 862                if (type & IPV6_ADDR_LINKLOCAL) {
 863                        struct net *net;
 864                        if (!addr->v6.sin6_scope_id)
 865                                return 0;
 866                        net = sock_net(&opt->inet.sk);
 867                        rcu_read_lock();
 868                        dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 869                        if (!dev ||
 870                            !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
 871                                rcu_read_unlock();
 872                                return 0;
 873                        }
 874                        rcu_read_unlock();
 875                } else if (type == IPV6_ADDR_MAPPED) {
 876                        if (!opt->v4mapped)
 877                                return 0;
 878                }
 879
 880                af = opt->pf->af;
 881        }
 882        return af->available(addr, opt);
 883}
 884
 885/* Verify that the provided sockaddr looks sendable.   Common verification,
 886 * has already been taken care of.
 887 */
 888static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 889{
 890        struct sctp_af *af = NULL;
 891
 892        /* ASSERT: address family has already been verified. */
 893        if (addr->sa.sa_family != AF_INET6)
 894                af = sctp_get_af_specific(addr->sa.sa_family);
 895        else {
 896                int type = ipv6_addr_type(&addr->v6.sin6_addr);
 897                struct net_device *dev;
 898
 899                if (type & IPV6_ADDR_LINKLOCAL) {
 900                        if (!addr->v6.sin6_scope_id)
 901                                return 0;
 902                        rcu_read_lock();
 903                        dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 904                                                   addr->v6.sin6_scope_id);
 905                        rcu_read_unlock();
 906                        if (!dev)
 907                                return 0;
 908                }
 909                af = opt->pf->af;
 910        }
 911
 912        return af != NULL;
 913}
 914
 915/* Fill in Supported Address Type information for INIT and INIT-ACK
 916 * chunks.   Note: In the future, we may want to look at sock options
 917 * to determine whether a PF_INET6 socket really wants to have IPV4
 918 * addresses.
 919 * Returns number of addresses supported.
 920 */
 921static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
 922                                      __be16 *types)
 923{
 924        types[0] = SCTP_PARAM_IPV6_ADDRESS;
 925        if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
 926                types[1] = SCTP_PARAM_IPV4_ADDRESS;
 927                return 2;
 928        }
 929        return 1;
 930}
 931
 932static const struct proto_ops inet6_seqpacket_ops = {
 933        .family            = PF_INET6,
 934        .owner             = THIS_MODULE,
 935        .release           = inet6_release,
 936        .bind              = inet6_bind,
 937        .connect           = inet_dgram_connect,
 938        .socketpair        = sock_no_socketpair,
 939        .accept            = inet_accept,
 940        .getname           = inet6_getname,
 941        .poll              = sctp_poll,
 942        .ioctl             = inet6_ioctl,
 943        .listen            = sctp_inet_listen,
 944        .shutdown          = inet_shutdown,
 945        .setsockopt        = sock_common_setsockopt,
 946        .getsockopt        = sock_common_getsockopt,
 947        .sendmsg           = inet_sendmsg,
 948        .recvmsg           = sock_common_recvmsg,
 949        .mmap              = sock_no_mmap,
 950#ifdef CONFIG_COMPAT
 951        .compat_setsockopt = compat_sock_common_setsockopt,
 952        .compat_getsockopt = compat_sock_common_getsockopt,
 953#endif
 954};
 955
 956static struct inet_protosw sctpv6_seqpacket_protosw = {
 957        .type          = SOCK_SEQPACKET,
 958        .protocol      = IPPROTO_SCTP,
 959        .prot          = &sctpv6_prot,
 960        .ops           = &inet6_seqpacket_ops,
 961        .no_check      = 0,
 962        .flags         = SCTP_PROTOSW_FLAG
 963};
 964static struct inet_protosw sctpv6_stream_protosw = {
 965        .type          = SOCK_STREAM,
 966        .protocol      = IPPROTO_SCTP,
 967        .prot          = &sctpv6_prot,
 968        .ops           = &inet6_seqpacket_ops,
 969        .no_check      = 0,
 970        .flags         = SCTP_PROTOSW_FLAG,
 971};
 972
 973static int sctp6_rcv(struct sk_buff *skb)
 974{
 975        return sctp_rcv(skb) ? -1 : 0;
 976}
 977
 978static const struct inet6_protocol sctpv6_protocol = {
 979        .handler      = sctp6_rcv,
 980        .err_handler  = sctp_v6_err,
 981        .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 982};
 983
 984static struct sctp_af sctp_af_inet6 = {
 985        .sa_family         = AF_INET6,
 986        .sctp_xmit         = sctp_v6_xmit,
 987        .setsockopt        = ipv6_setsockopt,
 988        .getsockopt        = ipv6_getsockopt,
 989        .get_dst           = sctp_v6_get_dst,
 990        .get_saddr         = sctp_v6_get_saddr,
 991        .copy_addrlist     = sctp_v6_copy_addrlist,
 992        .from_skb          = sctp_v6_from_skb,
 993        .from_sk           = sctp_v6_from_sk,
 994        .to_sk_saddr       = sctp_v6_to_sk_saddr,
 995        .to_sk_daddr       = sctp_v6_to_sk_daddr,
 996        .from_addr_param   = sctp_v6_from_addr_param,
 997        .to_addr_param     = sctp_v6_to_addr_param,
 998        .cmp_addr          = sctp_v6_cmp_addr,
 999        .scope             = sctp_v6_scope,
1000        .addr_valid        = sctp_v6_addr_valid,
1001        .inaddr_any        = sctp_v6_inaddr_any,
1002        .is_any            = sctp_v6_is_any,
1003        .available         = sctp_v6_available,
1004        .skb_iif           = sctp_v6_skb_iif,
1005        .is_ce             = sctp_v6_is_ce,
1006        .seq_dump_addr     = sctp_v6_seq_dump_addr,
1007        .ecn_capable       = sctp_v6_ecn_capable,
1008        .net_header_len    = sizeof(struct ipv6hdr),
1009        .sockaddr_len      = sizeof(struct sockaddr_in6),
1010#ifdef CONFIG_COMPAT
1011        .compat_setsockopt = compat_ipv6_setsockopt,
1012        .compat_getsockopt = compat_ipv6_getsockopt,
1013#endif
1014};
1015
1016static struct sctp_pf sctp_pf_inet6 = {
1017        .event_msgname = sctp_inet6_event_msgname,
1018        .skb_msgname   = sctp_inet6_skb_msgname,
1019        .af_supported  = sctp_inet6_af_supported,
1020        .cmp_addr      = sctp_inet6_cmp_addr,
1021        .bind_verify   = sctp_inet6_bind_verify,
1022        .send_verify   = sctp_inet6_send_verify,
1023        .supported_addrs = sctp_inet6_supported_addrs,
1024        .create_accept_sk = sctp_v6_create_accept_sk,
1025        .addr_v4map    = sctp_v6_addr_v4map,
1026        .af            = &sctp_af_inet6,
1027};
1028
1029/* Initialize IPv6 support and register with socket layer.  */
1030void sctp_v6_pf_init(void)
1031{
1032        /* Register the SCTP specific PF_INET6 functions. */
1033        sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1034
1035        /* Register the SCTP specific AF_INET6 functions. */
1036        sctp_register_af(&sctp_af_inet6);
1037}
1038
1039void sctp_v6_pf_exit(void)
1040{
1041        list_del(&sctp_af_inet6.list);
1042}
1043
1044/* Initialize IPv6 support and register with socket layer.  */
1045int sctp_v6_protosw_init(void)
1046{
1047        int rc;
1048
1049        rc = proto_register(&sctpv6_prot, 1);
1050        if (rc)
1051                return rc;
1052
1053        /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1054        inet6_register_protosw(&sctpv6_seqpacket_protosw);
1055        inet6_register_protosw(&sctpv6_stream_protosw);
1056
1057        return 0;
1058}
1059
1060void sctp_v6_protosw_exit(void)
1061{
1062        inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1063        inet6_unregister_protosw(&sctpv6_stream_protosw);
1064        proto_unregister(&sctpv6_prot);
1065}
1066
1067
1068/* Register with inet6 layer. */
1069int sctp_v6_add_protocol(void)
1070{
1071        /* Register notifier for inet6 address additions/deletions. */
1072        register_inet6addr_notifier(&sctp_inet6addr_notifier);
1073
1074        if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1075                return -EAGAIN;
1076
1077        return 0;
1078}
1079
1080/* Unregister with inet6 layer. */
1081void sctp_v6_del_protocol(void)
1082{
1083        inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1084        unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1085}
1086
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