bsd/netinet6/mld6.c

   1 /*      $FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.2 2001/07/03 11:01:54 ume Exp $       */
   2 /*      $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $   */
   3
   4 /*
   5  * Copyright (C) 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * Copyright (c) 1988 Stephen Deering.
  35  * Copyright (c) 1992, 1993
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * This code is derived from software contributed to Berkeley by
  39  * Stephen Deering of Stanford University.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  * 3. All advertising materials mentioning features or use of this software
  50  *    must display the following acknowledgement:
  51  *      This product includes software developed by the University of
  52  *      California, Berkeley and its contributors.
  53  * 4. Neither the name of the University nor the names of its contributors
  54  *    may be used to endorse or promote products derived from this software
  55  *    without specific prior written permission.
  56  *
  57  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  58  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  59  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  60  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  61  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  62  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  63  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  64  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  65  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  66  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  67  * SUCH DAMAGE.
  68  *
  69  *      @(#)igmp.c      8.1 (Berkeley) 7/19/93
  70  */
  71 /*
  72  * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
  73  * support for mandatory and extensible security protections.  This notice
  74  * is included in support of clause 2.2 (b) of the Apple Public License,
  75  * Version 2.0.
  76  */
  77
  78 #include <sys/param.h>
  79 #include <sys/systm.h>
  80 #include <sys/mbuf.h>
  81 #include <sys/socket.h>
  82 #include <sys/protosw.h>
  83 #include <sys/syslog.h>
  84
  85 #include <net/if.h>
  86
  87 #include <netinet/in.h>
  88 #include <netinet/in_var.h>
  89 #include <netinet/ip6.h>
  90 #include <netinet6/ip6_var.h>
  91 #include <netinet/icmp6.h>
  92 #include <netinet6/mld6_var.h>
  93
  94 #include <net/net_osdep.h>
  95
  96 #if CONFIG_MACF_NET
  97 #include <security/mac.h>
  98 #endif /* MAC_NET */
  99
 100 /*
 101  * Protocol constants
 102  */
 103
 104 /* denotes that the MLD max response delay field specifies time in milliseconds */
 105 #define MLD6_TIMER_SCALE        1000
 106 /*
 107  * time between repetitions of a node's initial report of interest in a
 108  * multicast address(in seconds)
 109  */
 110 #define MLD6_UNSOLICITED_REPORT_INTERVAL        10
 111
 112 extern lck_mtx_t *nd6_mutex;
 113 static struct ip6_pktopts ip6_opts;
 114 static int mld6_timers_are_running;
 115 static int mld6_init_done = 0 ;
 116 /* XXX: These are necessary for KAME's link-local hack */
 117 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 118 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 119
 120 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
 121
 122 void
 123 mld6_init()
 124 {
 125         static u_int8_t hbh_buf[8];
 126         struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
 127         u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
 128
 129         if (mld6_init_done)
 130                 return;
 131
 132         mld6_init_done = 1;
 133         mld6_timers_are_running = 0;
 134
 135         /* ip6h_nxt will be fill in later */
 136         hbh->ip6h_len = 0;      /* (8 >> 3) - 1 */
 137
 138         /* XXX: grotty hard coding... */
 139         hbh_buf[2] = IP6OPT_PADN;       /* 2 byte padding */
 140         hbh_buf[3] = 0;
 141         hbh_buf[4] = IP6OPT_RTALERT;
 142         hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
 143         bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
 144
 145         init_ip6pktopts(&ip6_opts);
 146         ip6_opts.ip6po_hbh = hbh;
 147 }
 148
 149 void
 150 mld6_start_listening(
 151         struct in6_multi *in6m)
 152 {
 153         /*
 154          * RFC2710 page 10:
 155          * The node never sends a Report or Done for the link-scope all-nodes
 156          * address.
 157          * MLD messages are never sent for multicast addresses whose scope is 0
 158          * (reserved) or 1 (node-local).
 159          */
 160         mld6_all_nodes_linklocal.s6_addr16[1] =
 161                 htons(in6m->in6m_ifp->if_index); /* XXX */
 162         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
 163             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
 164                 in6m->in6m_timer = 0;
 165                 in6m->in6m_state = MLD6_OTHERLISTENER;
 166         } else {
 167                 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
 168                 in6m->in6m_timer = MLD6_RANDOM_DELAY(
 169                         MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
 170                 in6m->in6m_state = MLD6_IREPORTEDLAST;
 171                 mld6_timers_are_running = 1;
 172         }
 173 }
 174
 175 void
 176 mld6_stop_listening(
 177         struct in6_multi *in6m)
 178 {
 179         mld6_all_nodes_linklocal.s6_addr16[1] =
 180                 htons(in6m->in6m_ifp->if_index); /* XXX */
 181         mld6_all_routers_linklocal.s6_addr16[1] =
 182                 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
 183
 184         if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
 185             (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
 186             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
 187                 mld6_sendpkt(in6m, MLD6_LISTENER_DONE,
 188                              &mld6_all_routers_linklocal);
 189 }
 190
 191 void
 192 mld6_input(
 193         struct mbuf *m,
 194         int off)
 195 {
 196         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 197         struct mld6_hdr *mldh;
 198         struct ifnet *ifp = m->m_pkthdr.rcvif;
 199         struct in6_multi *in6m;
 200         struct in6_ifaddr *ia;
 201         struct ifmultiaddr *ifma;
 202         int timer;              /* timer value in the MLD query header */
 203
 204 #ifndef PULLDOWN_TEST
 205         IP6_EXTHDR_CHECK(m, off, sizeof(*mldh), return);
 206         mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off);
 207 #else
 208         IP6_EXTHDR_GET(mldh, struct mld6_hdr *, m, off, sizeof(*mldh));
 209         if (mldh == NULL) {
 210                 icmp6stat.icp6s_tooshort++;
 211                 return;
 212         }
 213 #endif
 214
 215         /* source address validation */
 216         ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */
 217         if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
 218                 log(LOG_ERR,
 219                     "mld6_input: src %s is not link-local (grp=%s)\n",
 220                     ip6_sprintf(&ip6->ip6_src),
 221                     ip6_sprintf(&mldh->mld6_addr));
 222                 /*
 223                  * spec (RFC2710) does not explicitly
 224                  * specify to discard the packet from a non link-local
 225                  * source address. But we believe it's expected to do so.
 226                  * XXX: do we have to allow :: as source?
 227                  */
 228                 m_freem(m);
 229                 return;
 230         }
 231
 232         /*
 233          * In the MLD6 specification, there are 3 states and a flag.
 234          *
 235          * In Non-Listener state, we simply don't have a membership record.
 236          * In Delaying Listener state, our timer is running (in6m->in6m_timer)
 237          * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
 238          *
 239          * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
 240          * we have heard a report from another member, or MLD6_IREPORTEDLAST
 241          * if we sent the last report.
 242          */
 243         switch(mldh->mld6_type) {
 244         case MLD6_LISTENER_QUERY:
 245                 if (ifp->if_flags & IFF_LOOPBACK)
 246                         break;
 247
 248                 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) &&
 249                     !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
 250                         break;  /* print error or log stat? */
 251                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 252                         mldh->mld6_addr.s6_addr16[1] =
 253                                 htons(ifp->if_index); /* XXX */
 254
 255                 /*
 256                  * - Start the timers in all of our membership records
 257                  *   that the query applies to for the interface on
 258                  *   which the query arrived excl. those that belong
 259                  *   to the "all-nodes" group (ff02::1).
 260                  * - Restart any timer that is already running but has
 261                  *   A value longer than the requested timeout.
 262                  * - Use the value specified in the query message as
 263                  *   the maximum timeout.
 264                  */
 265                 ifnet_lock_exclusive(ifp);
 266                 IFP_TO_IA6(ifp, ia);
 267                 if (ia == NULL)
 268                         break;
 269
 270                 /*
 271                  * XXX: System timer resolution is too low to handle Max
 272                  * Response Delay, so set 1 to the internal timer even if
 273                  * the calculated value equals to zero when Max Response
 274                  * Delay is positive.
 275                  */
 276                 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
 277                 if (timer == 0 && mldh->mld6_maxdelay)
 278                         timer = 1;
 279                 mld6_all_nodes_linklocal.s6_addr16[1] =
 280                         htons(ifp->if_index); /* XXX */
 281
 282                 LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
 283                 {
 284                         if (ifma->ifma_addr->sa_family != AF_INET6)
 285                                 continue;
 286                         in6m = (struct in6_multi *)ifma->ifma_protospec;
 287                         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
 288                                         &mld6_all_nodes_linklocal) ||
 289                             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
 290                             IPV6_ADDR_SCOPE_LINKLOCAL)
 291                                 continue;
 292
 293                         if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) ||
 294                             IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr,
 295                                                 &in6m->in6m_addr))
 296                         {
 297                                 if (timer == 0) {
 298                                         /* send a report immediately */
 299                                         mld6_sendpkt(in6m, MLD6_LISTENER_REPORT,
 300                                                 NULL);
 301                                         in6m->in6m_timer = 0; /* reset timer */
 302                                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 303                                 }
 304                                 else if (in6m->in6m_timer == 0 || /*idle state*/
 305                                         in6m->in6m_timer > timer) {
 306                                         in6m->in6m_timer =
 307                                                 MLD6_RANDOM_DELAY(timer);
 308                                         mld6_timers_are_running = 1;
 309                                 }
 310                         }
 311                 }
 312                 ifnet_lock_done(ifp);
 313
 314                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 315                         mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 316                 break;
 317         case MLD6_LISTENER_REPORT:
 318                 /*
 319                  * For fast leave to work, we have to know that we are the
 320                  * last person to send a report for this group.  Reports
 321                  * can potentially get looped back if we are a multicast
 322                  * router, so discard reports sourced by me.
 323                  * Note that it is impossible to check IFF_LOOPBACK flag of
 324                  * ifp for this purpose, since ip6_mloopback pass the physical
 325                  * interface to looutput.
 326                  */
 327                 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
 328                         break;
 329
 330                 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
 331                         break;
 332
 333                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 334                         mldh->mld6_addr.s6_addr16[1] =
 335                                 htons(ifp->if_index); /* XXX */
 336                 /*
 337                  * If we belong to the group being reported, stop
 338                  * our timer for that group.
 339                  */
 340                 ifnet_lock_shared(ifp);
 341                 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m);
 342                 if (in6m) {
 343                         in6m->in6m_timer = 0; /* transit to idle state */
 344                         in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
 345                 }
 346                 ifnet_lock_done(ifp);
 347
 348                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 349                         mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 350                 break;
 351         default:                /* this is impossible */
 352                 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type);
 353                 break;
 354         }
 355
 356         m_freem(m);
 357 }
 358
 359 void
 360 mld6_fasttimeo()
 361 {
 362         struct in6_multi *in6m;
 363         struct in6_multistep step;
 364
 365         /*
 366          * Quick check to see if any work needs to be done, in order
 367          * to minimize the overhead of fasttimo processing.
 368          */
 369         if (!mld6_timers_are_running)
 370                 return;
 371
 372         lck_mtx_lock(nd6_mutex);
 373         mld6_timers_are_running = 0;
 374         IN6_FIRST_MULTI(step, in6m);
 375         while (in6m != NULL) {
 376                 if (in6m->in6m_timer == 0) {
 377                         /* do nothing */
 378                 } else if (--in6m->in6m_timer == 0) {
 379                         mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
 380                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 381                 } else {
 382                         mld6_timers_are_running = 1;
 383                 }
 384                 IN6_NEXT_MULTI(step, in6m);
 385         }
 386         lck_mtx_unlock(nd6_mutex);
 387 }
 388
 389 static void
 390 mld6_sendpkt(
 391         struct in6_multi *in6m,
 392         int type,
 393         const struct in6_addr *dst)
 394 {
 395         struct mbuf *mh, *md;
 396         struct mld6_hdr *mldh;
 397         struct ip6_hdr *ip6;
 398         struct ip6_moptions im6o;
 399         struct in6_ifaddr *ia;
 400         struct ifnet *ifp = in6m->in6m_ifp;
 401         struct ifnet *outif = NULL;
 402
 403         /*
 404          * At first, find a link local address on the outgoing interface
 405          * to use as the source address of the MLD packet.
 406          */
 407         if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
 408             == NULL)
 409                 return;
 410
 411         /*
 412          * Allocate mbufs to store ip6 header and MLD header.
 413          * We allocate 2 mbufs and make chain in advance because
 414          * it is more convenient when inserting the hop-by-hop option later.
 415          */
 416         MGETHDR(mh, M_DONTWAIT, MT_HEADER);
 417         if (mh == NULL)
 418                 return;
 419         MGET(md, M_DONTWAIT, MT_DATA);
 420         if (md == NULL) {
 421                 m_free(mh);
 422                 return;
 423         }
 424         mh->m_next = md;
 425
 426         mh->m_pkthdr.rcvif = NULL;
 427 #ifdef __darwin8_notyet
 428 #if CONFIG_MACF_NET
 429         mac_create_mbuf_linklayer(in6m->in6m_ifp, m);
 430 #endif
 431 #endif
 432         mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr);
 433         mh->m_len = sizeof(struct ip6_hdr);
 434         MH_ALIGN(mh, sizeof(struct ip6_hdr));
 435
 436         /* fill in the ip6 header */
 437         ip6 = mtod(mh, struct ip6_hdr *);
 438         ip6->ip6_flow = 0;
 439         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 440         ip6->ip6_vfc |= IPV6_VERSION;
 441         /* ip6_plen will be set later */
 442         ip6->ip6_nxt = IPPROTO_ICMPV6;
 443         /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
 444         ip6->ip6_src = ia->ia_addr.sin6_addr;
 445         ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
 446
 447         /* fill in the MLD header */
 448         md->m_len = sizeof(struct mld6_hdr);
 449         mldh = mtod(md, struct mld6_hdr *);
 450         mldh->mld6_type = type;
 451         mldh->mld6_code = 0;
 452         mldh->mld6_cksum = 0;
 453         /* XXX: we assume the function will not be called for query messages */
 454         mldh->mld6_maxdelay = 0;
 455         mldh->mld6_reserved = 0;
 456         mldh->mld6_addr = in6m->in6m_addr;
 457         if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 458                 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 459         mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
 460                                      sizeof(struct mld6_hdr));
 461
 462         /* construct multicast option */
 463         bzero(&im6o, sizeof(im6o));
 464         im6o.im6o_multicast_ifp = ifp;
 465         im6o.im6o_multicast_hlim = 1;
 466
 467         /*
 468          * Request loopback of the report if we are acting as a multicast
 469          * router, so that the process-level routing daemon can hear it.
 470          */
 471         im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
 472
 473         /* increment output statictics */
 474         icmp6stat.icp6s_outhist[type]++;
 475
 476         ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, 0);
 477         if (outif) {
 478                 icmp6_ifstat_inc(outif, ifs6_out_msg);
 479                 switch (type) {
 480                 case MLD6_LISTENER_QUERY:
 481                         icmp6_ifstat_inc(outif, ifs6_out_mldquery);
 482                         break;
 483                 case MLD6_LISTENER_REPORT:
 484                         icmp6_ifstat_inc(outif, ifs6_out_mldreport);
 485                         break;
 486                 case MLD6_LISTENER_DONE:
 487                         icmp6_ifstat_inc(outif, ifs6_out_mlddone);
 488                         break;
 489                 }
 490         }
 491 }
 492