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
  73 #include <sys/param.h>
  74 #include <sys/systm.h>
  75 #include <sys/mbuf.h>
  76 #include <sys/socket.h>
  77 #include <sys/protosw.h>
  78 #include <sys/syslog.h>
  79
  80 #include <net/if.h>
  81
  82 #include <netinet/in.h>
  83 #include <netinet/in_var.h>
  84 #include <netinet/ip6.h>
  85 #include <netinet6/ip6_var.h>
  86 #include <netinet/icmp6.h>
  87 #include <netinet6/mld6_var.h>
  88
  89 #include <net/net_osdep.h>
  90
  91 /*
  92  * Protocol constants
  93  */
  94
  95 /* denotes that the MLD max response delay field specifies time in milliseconds */
  96 #define MLD6_TIMER_SCALE        1000
  97 /*
  98  * time between repetitions of a node's initial report of interest in a
  99  * multicast address(in seconds)
 100  */
 101 #define MLD6_UNSOLICITED_REPORT_INTERVAL        10
 102
 103 extern lck_mtx_t *nd6_mutex;
 104 static struct ip6_pktopts ip6_opts;
 105 static int mld6_timers_are_running;
 106 static int mld6_init_done = 0 ;
 107 /* XXX: These are necessary for KAME's link-local hack */
 108 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 109 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 110
 111 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
 112
 113 void
 114 mld6_init()
 115 {
 116         static u_int8_t hbh_buf[8];
 117         struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
 118         u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
 119
 120         if (mld6_init_done)
 121                 return;
 122
 123         mld6_init_done = 1;
 124         mld6_timers_are_running = 0;
 125
 126         /* ip6h_nxt will be fill in later */
 127         hbh->ip6h_len = 0;      /* (8 >> 3) - 1 */
 128
 129         /* XXX: grotty hard coding... */
 130         hbh_buf[2] = IP6OPT_PADN;       /* 2 byte padding */
 131         hbh_buf[3] = 0;
 132         hbh_buf[4] = IP6OPT_RTALERT;
 133         hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
 134         bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
 135
 136         init_ip6pktopts(&ip6_opts);
 137         ip6_opts.ip6po_hbh = hbh;
 138 }
 139
 140 void
 141 mld6_start_listening(
 142         struct in6_multi *in6m)
 143 {
 144         int s = splnet();
 145
 146         /*
 147          * RFC2710 page 10:
 148          * The node never sends a Report or Done for the link-scope all-nodes
 149          * address.
 150          * MLD messages are never sent for multicast addresses whose scope is 0
 151          * (reserved) or 1 (node-local).
 152          */
 153         mld6_all_nodes_linklocal.s6_addr16[1] =
 154                 htons(in6m->in6m_ifp->if_index); /* XXX */
 155         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
 156             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
 157                 in6m->in6m_timer = 0;
 158                 in6m->in6m_state = MLD6_OTHERLISTENER;
 159         } else {
 160                 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
 161                 in6m->in6m_timer = MLD6_RANDOM_DELAY(
 162                         MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
 163                 in6m->in6m_state = MLD6_IREPORTEDLAST;
 164                 mld6_timers_are_running = 1;
 165         }
 166         splx(s);
 167 }
 168
 169 void
 170 mld6_stop_listening(
 171         struct in6_multi *in6m)
 172 {
 173         mld6_all_nodes_linklocal.s6_addr16[1] =
 174                 htons(in6m->in6m_ifp->if_index); /* XXX */
 175         mld6_all_routers_linklocal.s6_addr16[1] =
 176                 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
 177
 178         if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
 179             (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
 180             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
 181                 mld6_sendpkt(in6m, MLD6_LISTENER_DONE,
 182                              &mld6_all_routers_linklocal);
 183 }
 184
 185 void
 186 mld6_input(
 187         struct mbuf *m,
 188         int off)
 189 {
 190         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 191         struct mld6_hdr *mldh;
 192         struct ifnet *ifp = m->m_pkthdr.rcvif;
 193         struct in6_multi *in6m;
 194         struct in6_ifaddr *ia;
 195         struct ifmultiaddr *ifma;
 196         int timer;              /* timer value in the MLD query header */
 197
 198 #ifndef PULLDOWN_TEST
 199         IP6_EXTHDR_CHECK(m, off, sizeof(*mldh), return);
 200         mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off);
 201 #else
 202         IP6_EXTHDR_GET(mldh, struct mld6_hdr *, m, off, sizeof(*mldh));
 203         if (mldh == NULL) {
 204                 icmp6stat.icp6s_tooshort++;
 205                 return;
 206         }
 207 #endif
 208
 209         /* source address validation */
 210         ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */
 211         if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
 212                 log(LOG_ERR,
 213                     "mld6_input: src %s is not link-local (grp=%s)\n",
 214                     ip6_sprintf(&ip6->ip6_src),
 215                     ip6_sprintf(&mldh->mld6_addr));
 216                 /*
 217                  * spec (RFC2710) does not explicitly
 218                  * specify to discard the packet from a non link-local
 219                  * source address. But we believe it's expected to do so.
 220                  * XXX: do we have to allow :: as source?
 221                  */
 222                 m_freem(m);
 223                 return;
 224         }
 225
 226         /*
 227          * In the MLD6 specification, there are 3 states and a flag.
 228          *
 229          * In Non-Listener state, we simply don't have a membership record.
 230          * In Delaying Listener state, our timer is running (in6m->in6m_timer)
 231          * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
 232          *
 233          * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
 234          * we have heard a report from another member, or MLD6_IREPORTEDLAST
 235          * if we sent the last report.
 236          */
 237         switch(mldh->mld6_type) {
 238         case MLD6_LISTENER_QUERY:
 239                 if (ifp->if_flags & IFF_LOOPBACK)
 240                         break;
 241
 242                 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) &&
 243                     !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
 244                         break;  /* print error or log stat? */
 245                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 246                         mldh->mld6_addr.s6_addr16[1] =
 247                                 htons(ifp->if_index); /* XXX */
 248
 249                 /*
 250                  * - Start the timers in all of our membership records
 251                  *   that the query applies to for the interface on
 252                  *   which the query arrived excl. those that belong
 253                  *   to the "all-nodes" group (ff02::1).
 254                  * - Restart any timer that is already running but has
 255                  *   A value longer than the requested timeout.
 256                  * - Use the value specified in the query message as
 257                  *   the maximum timeout.
 258                  */
 259                 ifnet_lock_exclusive(ifp);
 260                 IFP_TO_IA6(ifp, ia);
 261                 if (ia == NULL)
 262                         break;
 263
 264                 /*
 265                  * XXX: System timer resolution is too low to handle Max
 266                  * Response Delay, so set 1 to the internal timer even if
 267                  * the calculated value equals to zero when Max Response
 268                  * Delay is positive.
 269                  */
 270                 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
 271                 if (timer == 0 && mldh->mld6_maxdelay)
 272                         timer = 1;
 273                 mld6_all_nodes_linklocal.s6_addr16[1] =
 274                         htons(ifp->if_index); /* XXX */
 275
 276                 LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
 277                 {
 278                         if (ifma->ifma_addr->sa_family != AF_INET6)
 279                                 continue;
 280                         in6m = (struct in6_multi *)ifma->ifma_protospec;
 281                         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
 282                                         &mld6_all_nodes_linklocal) ||
 283                             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
 284                             IPV6_ADDR_SCOPE_LINKLOCAL)
 285                                 continue;
 286
 287                         if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) ||
 288                             IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr,
 289                                                 &in6m->in6m_addr))
 290                         {
 291                                 if (timer == 0) {
 292                                         /* send a report immediately */
 293                                         mld6_sendpkt(in6m, MLD6_LISTENER_REPORT,
 294                                                 NULL);
 295                                         in6m->in6m_timer = 0; /* reset timer */
 296                                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 297                                 }
 298                                 else if (in6m->in6m_timer == 0 || /*idle state*/
 299                                         in6m->in6m_timer > timer) {
 300                                         in6m->in6m_timer =
 301                                                 MLD6_RANDOM_DELAY(timer);
 302                                         mld6_timers_are_running = 1;
 303                                 }
 304                         }
 305                 }
 306                 ifnet_lock_done(ifp);
 307
 308                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 309                         mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 310                 break;
 311         case MLD6_LISTENER_REPORT:
 312                 /*
 313                  * For fast leave to work, we have to know that we are the
 314                  * last person to send a report for this group.  Reports
 315                  * can potentially get looped back if we are a multicast
 316                  * router, so discard reports sourced by me.
 317                  * Note that it is impossible to check IFF_LOOPBACK flag of
 318                  * ifp for this purpose, since ip6_mloopback pass the physical
 319                  * interface to looutput.
 320                  */
 321                 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
 322                         break;
 323
 324                 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
 325                         break;
 326
 327                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 328                         mldh->mld6_addr.s6_addr16[1] =
 329                                 htons(ifp->if_index); /* XXX */
 330                 /*
 331                  * If we belong to the group being reported, stop
 332                  * our timer for that group.
 333                  */
 334                 ifnet_lock_shared(ifp);
 335                 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m);
 336                 if (in6m) {
 337                         in6m->in6m_timer = 0; /* transit to idle state */
 338                         in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
 339                 }
 340                 ifnet_lock_done(ifp);
 341
 342                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 343                         mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 344                 break;
 345         default:                /* this is impossible */
 346                 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type);
 347                 break;
 348         }
 349
 350         m_freem(m);
 351 }
 352
 353 void
 354 mld6_fasttimeo()
 355 {
 356         struct in6_multi *in6m;
 357         struct in6_multistep step;
 358
 359         /*
 360          * Quick check to see if any work needs to be done, in order
 361          * to minimize the overhead of fasttimo processing.
 362          */
 363         if (!mld6_timers_are_running)
 364                 return;
 365
 366         lck_mtx_lock(nd6_mutex);
 367         mld6_timers_are_running = 0;
 368         IN6_FIRST_MULTI(step, in6m);
 369         while (in6m != NULL) {
 370                 if (in6m->in6m_timer == 0) {
 371                         /* do nothing */
 372                 } else if (--in6m->in6m_timer == 0) {
 373                         mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
 374                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 375                 } else {
 376                         mld6_timers_are_running = 1;
 377                 }
 378                 IN6_NEXT_MULTI(step, in6m);
 379         }
 380         lck_mtx_unlock(nd6_mutex);
 381 }
 382
 383 static void
 384 mld6_sendpkt(
 385         struct in6_multi *in6m,
 386         int type,
 387         const struct in6_addr *dst)
 388 {
 389         struct mbuf *mh, *md;
 390         struct mld6_hdr *mldh;
 391         struct ip6_hdr *ip6;
 392         struct ip6_moptions im6o;
 393         struct in6_ifaddr *ia;
 394         struct ifnet *ifp = in6m->in6m_ifp;
 395         struct ifnet *outif = NULL;
 396
 397         /*
 398          * At first, find a link local address on the outgoing interface
 399          * to use as the source address of the MLD packet.
 400          */
 401         if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
 402             == NULL)
 403                 return;
 404
 405         /*
 406          * Allocate mbufs to store ip6 header and MLD header.
 407          * We allocate 2 mbufs and make chain in advance because
 408          * it is more convenient when inserting the hop-by-hop option later.
 409          */
 410         MGETHDR(mh, M_DONTWAIT, MT_HEADER);
 411         if (mh == NULL)
 412                 return;
 413         MGET(md, M_DONTWAIT, MT_DATA);
 414         if (md == NULL) {
 415                 m_free(mh);
 416                 return;
 417         }
 418         mh->m_next = md;
 419
 420         mh->m_pkthdr.rcvif = NULL;
 421         mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr);
 422         mh->m_len = sizeof(struct ip6_hdr);
 423         MH_ALIGN(mh, sizeof(struct ip6_hdr));
 424
 425         /* fill in the ip6 header */
 426         ip6 = mtod(mh, struct ip6_hdr *);
 427         ip6->ip6_flow = 0;
 428         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 429         ip6->ip6_vfc |= IPV6_VERSION;
 430         /* ip6_plen will be set later */
 431         ip6->ip6_nxt = IPPROTO_ICMPV6;
 432         /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
 433         ip6->ip6_src = ia->ia_addr.sin6_addr;
 434         ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
 435
 436         /* fill in the MLD header */
 437         md->m_len = sizeof(struct mld6_hdr);
 438         mldh = mtod(md, struct mld6_hdr *);
 439         mldh->mld6_type = type;
 440         mldh->mld6_code = 0;
 441         mldh->mld6_cksum = 0;
 442         /* XXX: we assume the function will not be called for query messages */
 443         mldh->mld6_maxdelay = 0;
 444         mldh->mld6_reserved = 0;
 445         mldh->mld6_addr = in6m->in6m_addr;
 446         if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 447                 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 448         mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
 449                                      sizeof(struct mld6_hdr));
 450
 451         /* construct multicast option */
 452         bzero(&im6o, sizeof(im6o));
 453         im6o.im6o_multicast_ifp = ifp;
 454         im6o.im6o_multicast_hlim = 1;
 455
 456         /*
 457          * Request loopback of the report if we are acting as a multicast
 458          * router, so that the process-level routing daemon can hear it.
 459          */
 460         im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
 461
 462         /* increment output statictics */
 463         icmp6stat.icp6s_outhist[type]++;
 464
 465         ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, 0);
 466         if (outif) {
 467                 icmp6_ifstat_inc(outif, ifs6_out_msg);
 468                 switch (type) {
 469                 case MLD6_LISTENER_QUERY:
 470                         icmp6_ifstat_inc(outif, ifs6_out_mldquery);
 471                         break;
 472                 case MLD6_LISTENER_REPORT:
 473                         icmp6_ifstat_inc(outif, ifs6_out_mldreport);
 474                         break;
 475                 case MLD6_LISTENER_DONE:
 476                         icmp6_ifstat_inc(outif, ifs6_out_mlddone);
 477                         break;
 478                 }
 479         }
 480 }