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