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