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