bsd/netinet6/mld6.c

   1 /*      $KAME: mld6.c,v 1.17 2000/03/01 12:37:25 itojun Exp $   */
   2
   3 /*
   4  * Copyright (C) 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Copyright (c) 1988 Stephen Deering.
  34  * Copyright (c) 1992, 1993
  35  *      The Regents of the University of California.  All rights reserved.
  36  *
  37  * This code is derived from software contributed to Berkeley by
  38  * Stephen Deering of Stanford University.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. All advertising materials mentioning features or use of this software
  49  *    must display the following acknowledgement:
  50  *      This product includes software developed by the University of
  51  *      California, Berkeley and its contributors.
  52  * 4. Neither the name of the University nor the names of its contributors
  53  *    may be used to endorse or promote products derived from this software
  54  *    without specific prior written permission.
  55  *
  56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  66  * SUCH DAMAGE.
  67  *
  68  *      @(#)igmp.c      8.1 (Berkeley) 7/19/93
  69  */
  70
  71 #if (defined(__FreeBSD__) && __FreeBSD__ >= 3) || defined(__NetBSD__)
  72 #include "opt_inet.h"
  73 #endif
  74
  75 #include <sys/param.h>
  76 #include <sys/systm.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/socket.h>
  79 #include <sys/protosw.h>
  80 #include <sys/syslog.h>
  81
  82 #include <net/if.h>
  83
  84 #include <netinet/in.h>
  85 #include <netinet/in_var.h>
  86 #include <netinet/ip6.h>
  87 #include <netinet6/ip6_var.h>
  88 #include <netinet/icmp6.h>
  89 #include <netinet6/mld6_var.h>
  90
  91 #include <net/net_osdep.h>
  92
  93 /*
  94  * Protocol constants
  95  */
  96
  97 /* denotes that the MLD max response delay field specifies time in milliseconds */
  98 #define MLD6_TIMER_SCALE        1000
  99 /*
 100  * time between repetitions of a node's initial report of interest in a
 101  * multicast address(in seconds)
 102  */
 103 #define MLD6_UNSOLICITED_REPORT_INTERVAL        10
 104
 105 static struct ip6_pktopts ip6_opts;
 106 static int mld6_timers_are_running;
 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 __P((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         mld6_timers_are_running = 0;
 121
 122         /* ip6h_nxt will be fill in later */
 123         hbh->ip6h_len = 0;      /* (8 >> 3) - 1 */
 124
 125         /* XXX: grotty hard coding... */
 126         hbh_buf[2] = IP6OPT_PADN;       /* 2 byte padding */
 127         hbh_buf[3] = 0;
 128         hbh_buf[4] = IP6OPT_RTALERT;
 129         hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
 130         bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
 131
 132         ip6_opts.ip6po_hbh = hbh;
 133         /* We will specify the hoplimit by a multicast option. */
 134         ip6_opts.ip6po_hlim = -1;
 135 }
 136
 137 void
 138 mld6_start_listening(in6m)
 139         struct in6_multi *in6m;
 140 {
 141 #ifdef __NetBSD__
 142         int s = splsoftnet();
 143 #else
 144         int s = splnet();
 145 #endif
 146
 147         /*
 148          * RFC2710 page 10:
 149          * The node never sends a Report or Done for the link-scope all-nodes
 150          * address.
 151          * MLD messages are never sent for multicast addresses whose scope is 0
 152          * (reserved) or 1 (node-local).
 153          */
 154         mld6_all_nodes_linklocal.s6_addr16[1] =
 155                 htons(in6m->in6m_ifp->if_index); /* XXX */
 156         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
 157             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
 158                 in6m->in6m_timer = 0;
 159                 in6m->in6m_state = MLD6_OTHERLISTENER;
 160         } else {
 161                 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
 162                 in6m->in6m_timer = MLD6_RANDOM_DELAY(
 163                         MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
 164                 in6m->in6m_state = MLD6_IREPORTEDLAST;
 165                 mld6_timers_are_running = 1;
 166         }
 167         splx(s);
 168 }
 169
 170 void
 171 mld6_stop_listening(in6m)
 172         struct in6_multi *in6m;
 173 {
 174         mld6_all_nodes_linklocal.s6_addr16[1] =
 175                 htons(in6m->in6m_ifp->if_index); /* XXX */
 176         mld6_all_routers_linklocal.s6_addr16[1] =
 177                 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
 178
 179         if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
 180             (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
 181             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
 182                 mld6_sendpkt(in6m, MLD6_LISTENER_DONE,
 183                              &mld6_all_routers_linklocal);
 184 }
 185
 186 void
 187 mld6_input(m, off)
 188         struct mbuf *m;
 189         int off;
 190 {
 191         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 192         struct mld6_hdr *mldh;
 193         struct ifnet *ifp = m->m_pkthdr.rcvif;
 194         struct in6_multi *in6m;
 195         struct in6_ifaddr *ia;
 196 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 || defined (__APPLE__)
 197         struct ifmultiaddr *ifma;
 198 #endif
 199         int timer;              /* timer value in the MLD query header */
 200
 201         /* source address validation */
 202         if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
 203                 log(LOG_ERR,
 204                     "mld6_input: src %s is not link-local\n",
 205                     ip6_sprintf(&ip6->ip6_src));
 206                 /*
 207                  * spec (RFC2710) does not explicitly
 208                  * specify to discard the packet from a non link-local
 209                  * source address. But we believe it's expected to do so.
 210                  */
 211                 m_freem(m);
 212                 return;
 213         }
 214
 215 #ifndef PULLDOWN_TEST
 216         IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
 217         mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off);
 218 #else
 219         IP6_EXTHDR_GET(mldh, struct mld6_hdr *, m, off, sizeof(*mldh));
 220         if (mldh == NULL) {
 221                 icmp6stat.icp6s_tooshort++;
 222                 return;
 223         }
 224 #endif
 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                 IFP_TO_IA6(ifp, ia);
 260                 if (ia == NULL)
 261                         break;
 262
 263                 /*
 264                  * XXX: System timer resolution is too low to handle Max
 265                  * Response Delay, so set 1 to the internal timer even if
 266                  * the calculated value equals to zero when Max Response
 267                  * Delay is positive.
 268                  */
 269                 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
 270                 if (timer == 0 && mldh->mld6_maxdelay)
 271                         timer = 1;
 272                 mld6_all_nodes_linklocal.s6_addr16[1] =
 273                         htons(ifp->if_index); /* XXX */
 274
 275 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 || defined (__APPLE__)
 276                 LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
 277 #else
 278                 for (in6m = ia->ia6_multiaddrs.lh_first;
 279                      in6m;
 280                      in6m = in6m->in6m_entry.le_next)
 281 #endif
 282                 {
 283 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 || defined (__APPLE__)
 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 #else
 293                         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
 294                                                 &mld6_all_nodes_linklocal) ||
 295                             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
 296                             IPV6_ADDR_SCOPE_LINKLOCAL)
 297                                 continue;
 298 #endif
 299
 300                         if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) ||
 301                             IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr,
 302                                                 &in6m->in6m_addr))
 303                         {
 304                                 if (timer == 0) {
 305                                         /* send a report immediately */
 306                                         mld6_sendpkt(in6m, MLD6_LISTENER_REPORT,
 307                                                 NULL);
 308                                         in6m->in6m_timer = 0; /* reset timer */
 309                                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 310                                 }
 311                                 else if (in6m->in6m_timer == 0 || /*idle state*/
 312                                         in6m->in6m_timer > timer) {
 313                                         in6m->in6m_timer =
 314                                                 MLD6_RANDOM_DELAY(timer);
 315                                         mld6_timers_are_running = 1;
 316                                 }
 317                         }
 318                 }
 319
 320                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 321                         mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 322                 break;
 323         case MLD6_LISTENER_REPORT:
 324                 /*
 325                  * For fast leave to work, we have to know that we are the
 326                  * last person to send a report for this group.  Reports
 327                  * can potentially get looped back if we are a multicast
 328                  * router, so discard reports sourced by me.
 329                  * Note that it is impossible to check IFF_LOOPBACK flag of
 330                  * ifp for this purpose, since ip6_mloopback pass the physical
 331                  * interface to looutput.
 332                  */
 333                 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
 334                         break;
 335
 336                 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
 337                         break;
 338
 339                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 340                         mldh->mld6_addr.s6_addr16[1] =
 341                                 htons(ifp->if_index); /* XXX */
 342                 /*
 343                  * If we belong to the group being reported, stop
 344                  * our timer for that group.
 345                  */
 346                 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m);
 347                 if (in6m) {
 348                         in6m->in6m_timer = 0; /* transit to idle state */
 349                         in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
 350                 }
 351
 352                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 353                         mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 354                 break;
 355         default:                /* this is impossible */
 356                 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type);
 357                 break;
 358         }
 359
 360         m_freem(m);
 361 }
 362
 363 void
 364 mld6_fasttimeo()
 365 {
 366         register struct in6_multi *in6m;
 367         struct in6_multistep step;
 368         int s;
 369
 370         /*
 371          * Quick check to see if any work needs to be done, in order
 372          * to minimize the overhead of fasttimo processing.
 373          */
 374         if (!mld6_timers_are_running)
 375                 return;
 376
 377 #ifdef __NetBSD__
 378         s = splsoftnet();
 379 #else
 380         s = splnet();
 381 #endif
 382         mld6_timers_are_running = 0;
 383         IN6_FIRST_MULTI(step, in6m);
 384         while (in6m != NULL) {
 385                 if (in6m->in6m_timer == 0) {
 386                         /* do nothing */
 387                 } else if (--in6m->in6m_timer == 0) {
 388                         mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
 389                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 390                 } else {
 391                         mld6_timers_are_running = 1;
 392                 }
 393                 IN6_NEXT_MULTI(step, in6m);
 394         }
 395         splx(s);
 396 }
 397
 398 static void
 399 mld6_sendpkt(in6m, type, dst)
 400         struct in6_multi *in6m;
 401         int type;
 402         const struct in6_addr *dst;
 403 {
 404         struct mbuf *mh, *md;
 405         struct mld6_hdr *mldh;
 406         struct ip6_hdr *ip6;
 407         struct ip6_moptions im6o;
 408         struct in6_ifaddr *ia;
 409         struct ifnet *ifp = in6m->in6m_ifp;
 410         struct ifnet *outif = NULL;
 411
 412         /*
 413          * At first, find a link local address on the outgoing interface
 414          * to use as the source address of the MLD packet.
 415          */
 416         if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
 417             == NULL)
 418                 return;
 419
 420         /*
 421          * Allocate mbufs to store ip6 header and MLD header.
 422          * We allocate 2 mbufs and make chain in advance because
 423          * it is more convenient when inserting the hop-by-hop option later.
 424          */
 425         MGETHDR(mh, M_DONTWAIT, MT_HEADER);
 426         if (mh == NULL)
 427                 return;
 428         MGET(md, M_DONTWAIT, MT_DATA);
 429         if (md == NULL) {
 430                 m_free(mh);
 431                 return;
 432         }
 433         mh->m_next = md;
 434
 435         mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr);
 436         mh->m_len = sizeof(struct ip6_hdr);
 437         MH_ALIGN(mh, sizeof(struct ip6_hdr));
 438
 439         /* fill in the ip6 header */
 440         ip6 = mtod(mh, struct ip6_hdr *);
 441         ip6->ip6_flow = 0;
 442         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 443         ip6->ip6_vfc |= IPV6_VERSION;
 444         /* ip6_plen will be set later */
 445         ip6->ip6_nxt = IPPROTO_ICMPV6;
 446         /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
 447         ip6->ip6_src = ia->ia_addr.sin6_addr;
 448         ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
 449
 450         /* fill in the MLD header */
 451         md->m_len = sizeof(struct mld6_hdr);
 452         mldh = mtod(md, struct mld6_hdr *);
 453         mldh->mld6_type = type;
 454         mldh->mld6_code = 0;
 455         mldh->mld6_cksum = 0;
 456         /* XXX: we assume the function will not be called for query messages */
 457         mldh->mld6_maxdelay = 0;
 458         mldh->mld6_reserved = 0;
 459         mldh->mld6_addr = in6m->in6m_addr;
 460         if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
 461                 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
 462         mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
 463                                      sizeof(struct mld6_hdr));
 464
 465         /* construct multicast option */
 466         bzero(&im6o, sizeof(im6o));
 467         im6o.im6o_multicast_ifp = ifp;
 468         im6o.im6o_multicast_hlim = 1;
 469
 470         /*
 471          * Request loopback of the report if we are acting as a multicast
 472          * router, so that the process-level routing daemon can hear it.
 473          */
 474         im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
 475
 476         /* increment output statictics */
 477         icmp6stat.icp6s_outhist[type]++;
 478
 479         ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif);
 480         if (outif) {
 481                 icmp6_ifstat_inc(outif, ifs6_out_msg);
 482                 switch(type) {
 483                  case MLD6_LISTENER_QUERY:
 484                          icmp6_ifstat_inc(outif, ifs6_out_mldquery);
 485                          break;
 486                  case MLD6_LISTENER_REPORT:
 487                          icmp6_ifstat_inc(outif, ifs6_out_mldreport);
 488                          break;
 489                  case MLD6_LISTENER_DONE:
 490                          icmp6_ifstat_inc(outif, ifs6_out_mlddone);
 491                          break;
 492                 }
 493         }
 494 }