sys/netinet6/mld6.c

   1 /*      $FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.4 2003/01/23 21:06:47 sam Exp $       */
   2 /*      $DragonFly: src/sys/netinet6/mld6.c,v 1.6 2005/06/03 19:56:08 eirikn Exp $      */
   3 /*      $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $   */
   4
   5 /*
   6  * Copyright (C) 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 1988 Stephen Deering.
  36  * Copyright (c) 1992, 1993
  37  *      The Regents of the University of California.  All rights reserved.
  38  *
  39  * This code is derived from software contributed to Berkeley by
  40  * Stephen Deering of Stanford University.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 3. All advertising materials mentioning features or use of this software
  51  *    must display the following acknowledgement:
  52  *      This product includes software developed by the University of
  53  *      California, Berkeley and its contributors.
  54  * 4. Neither the name of the University nor the names of its contributors
  55  *    may be used to endorse or promote products derived from this software
  56  *    without specific prior written permission.
  57  *
  58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  68  * SUCH DAMAGE.
  69  *
  70  *      @(#)igmp.c      8.1 (Berkeley) 7/19/93
  71  */
  72
  73 #include "opt_inet.h"
  74 #include "opt_inet6.h"
  75
  76 #include <sys/param.h>
  77 #include <sys/systm.h>
  78 #include <sys/mbuf.h>
  79 #include <sys/socket.h>
  80 #include <sys/protosw.h>
  81 #include <sys/syslog.h>
  82 #include <sys/thread2.h>
  83
  84 #include <net/if.h>
  85
  86 #include <netinet/in.h>
  87 #include <netinet/in_var.h>
  88 #include <netinet/ip6.h>
  89 #include <netinet6/ip6_var.h>
  90 #include <netinet/icmp6.h>
  91 #include <netinet6/mld6_var.h>
  92
  93 #include <net/net_osdep.h>
  94
  95 /*
  96  * Protocol constants
  97  */
  98
  99 /* denotes that the MLD max response delay field specifies time in milliseconds */
 100 #define MLD6_TIMER_SCALE        1000
 101 /*
 102  * time between repetitions of a node's initial report of interest in a
 103  * multicast address(in seconds)
 104  */
 105 #define MLD6_UNSOLICITED_REPORT_INTERVAL        10
 106
 107 static struct ip6_pktopts ip6_opts;
 108 static int mld6_timers_are_running;
 109 /* XXX: These are necessary for KAME's link-local hack */
 110 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 111 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 112
 113 static void mld6_sendpkt (struct in6_multi *, int, const struct in6_addr *);
 114
 115 void
 116 mld6_init(void)
 117 {
 118         static u_int8_t hbh_buf[8];
 119         struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
 120         u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
 121
 122         mld6_timers_are_running = 0;
 123
 124         /* ip6h_nxt will be fill in later */
 125         hbh->ip6h_len = 0;      /* (8 >> 3) - 1 */
 126
 127         /* XXX: grotty hard coding... */
 128         hbh_buf[2] = IP6OPT_PADN;       /* 2 byte padding */
 129         hbh_buf[3] = 0;
 130         hbh_buf[4] = IP6OPT_RTALERT;
 131         hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
 132         bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
 133
 134         init_ip6pktopts(&ip6_opts);
 135         ip6_opts.ip6po_hbh = hbh;
 136 }
 137
 138 void
 139 mld6_start_listening(struct in6_multi *in6m)
 140 {
 141         crit_enter();
 142         /*
 143          * RFC2710 page 10:
 144          * The node never sends a Report or Done for the link-scope all-nodes
 145          * address.
 146          * MLD messages are never sent for multicast addresses whose scope is 0
 147          * (reserved) or 1 (node-local).
 148          */
 149         mld6_all_nodes_linklocal.s6_addr16[1] =
 150                 htons(in6m->in6m_ifp->if_index); /* XXX */
 151         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
 152             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
 153                 in6m->in6m_timer = 0;
 154                 in6m->in6m_state = MLD6_OTHERLISTENER;
 155         } else {
 156                 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
 157                 in6m->in6m_timer = MLD6_RANDOM_DELAY(
 158                         MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
 159                 in6m->in6m_state = MLD6_IREPORTEDLAST;
 160                 mld6_timers_are_running = 1;
 161         }
 162         crit_exit();
 163 }
 164
 165 void
 166 mld6_stop_listening(struct in6_multi *in6m)
 167 {
 168         mld6_all_nodes_linklocal.s6_addr16[1] =
 169                 htons(in6m->in6m_ifp->if_index); /* XXX */
 170         mld6_all_routers_linklocal.s6_addr16[1] =
 171                 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
 172
 173         if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
 174             (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
 175             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
 176                 mld6_sendpkt(in6m, MLD_LISTENER_DONE,
 177                              &mld6_all_routers_linklocal);
 178 }
 179
 180 void
 181 mld6_input(struct mbuf *m, int off)
 182 {
 183         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 184         struct mld_hdr *mldh;
 185         struct ifnet *ifp = m->m_pkthdr.rcvif;
 186         struct in6_multi *in6m;
 187         struct in6_ifaddr *ia;
 188         struct ifmultiaddr *ifma;
 189         int timer;              /* timer value in the MLD query header */
 190
 191 #ifndef PULLDOWN_TEST
 192         IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
 193         mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
 194 #else
 195         IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
 196         if (mldh == NULL) {
 197                 icmp6stat.icp6s_tooshort++;
 198                 return;
 199         }
 200 #endif
 201
 202         /* source address validation */
 203         ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */
 204         if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
 205                 log(LOG_ERR,
 206                     "mld6_input: src %s is not link-local (grp=%s)\n",
 207                     ip6_sprintf(&ip6->ip6_src),
 208                     ip6_sprintf(&mldh->mld_addr));
 209                 /*
 210                  * spec (RFC2710) does not explicitly
 211                  * specify to discard the packet from a non link-local
 212                  * source address. But we believe it's expected to do so.
 213                  * XXX: do we have to allow :: as source?
 214                  */
 215                 m_freem(m);
 216                 return;
 217         }
 218
 219         /*
 220          * In the MLD6 specification, there are 3 states and a flag.
 221          *
 222          * In Non-Listener state, we simply don't have a membership record.
 223          * In Delaying Listener state, our timer is running (in6m->in6m_timer)
 224          * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
 225          *
 226          * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
 227          * we have heard a report from another member, or MLD6_IREPORTEDLAST
 228          * if we sent the last report.
 229          */
 230         switch(mldh->mld_type) {
 231         case MLD_LISTENER_QUERY:
 232                 if (ifp->if_flags & IFF_LOOPBACK)
 233                         break;
 234
 235                 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
 236                     !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
 237                         break;  /* print error or log stat? */
 238                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 239                         mldh->mld_addr.s6_addr16[1] =
 240                                 htons(ifp->if_index); /* XXX */
 241
 242                 /*
 243                  * - Start the timers in all of our membership records
 244                  *   that the query applies to for the interface on
 245                  *   which the query arrived excl. those that belong
 246                  *   to the "all-nodes" group (ff02::1).
 247                  * - Restart any timer that is already running but has
 248                  *   A value longer than the requested timeout.
 249                  * - Use the value specified in the query message as
 250                  *   the maximum timeout.
 251                  */
 252                 IFP_TO_IA6(ifp, ia);
 253                 if (ia == NULL)
 254                         break;
 255
 256                 /*
 257                  * XXX: System timer resolution is too low to handle Max
 258                  * Response Delay, so set 1 to the internal timer even if
 259                  * the calculated value equals to zero when Max Response
 260                  * Delay is positive.
 261                  */
 262                 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
 263                 if (timer == 0 && mldh->mld_maxdelay)
 264                         timer = 1;
 265                 mld6_all_nodes_linklocal.s6_addr16[1] =
 266                         htons(ifp->if_index); /* XXX */
 267
 268                 LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
 269                 {
 270                         if (ifma->ifma_addr->sa_family != AF_INET6)
 271                                 continue;
 272                         in6m = (struct in6_multi *)ifma->ifma_protospec;
 273                         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
 274                                         &mld6_all_nodes_linklocal) ||
 275                             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
 276                             IPV6_ADDR_SCOPE_LINKLOCAL)
 277                                 continue;
 278
 279                         if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) ||
 280                             IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
 281                                                 &in6m->in6m_addr))
 282                         {
 283                                 if (timer == 0) {
 284                                         /* send a report immediately */
 285                                         mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
 286                                                 NULL);
 287                                         in6m->in6m_timer = 0; /* reset timer */
 288                                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 289                                 }
 290                                 else if (in6m->in6m_timer == 0 || /*idle state*/
 291                                         in6m->in6m_timer > timer) {
 292                                         in6m->in6m_timer =
 293                                                 MLD6_RANDOM_DELAY(timer);
 294                                         mld6_timers_are_running = 1;
 295                                 }
 296                         }
 297                 }
 298
 299                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 300                         mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
 301                 break;
 302         case MLD_LISTENER_REPORT:
 303                 /*
 304                  * For fast leave to work, we have to know that we are the
 305                  * last person to send a report for this group.  Reports
 306                  * can potentially get looped back if we are a multicast
 307                  * router, so discard reports sourced by me.
 308                  * Note that it is impossible to check IFF_LOOPBACK flag of
 309                  * ifp for this purpose, since ip6_mloopback pass the physical
 310                  * interface to looutput.
 311                  */
 312                 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
 313                         break;
 314
 315                 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
 316                         break;
 317
 318                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 319                         mldh->mld_addr.s6_addr16[1] =
 320                                 htons(ifp->if_index); /* XXX */
 321                 /*
 322                  * If we belong to the group being reported, stop
 323                  * our timer for that group.
 324                  */
 325                 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m);
 326                 if (in6m) {
 327                         in6m->in6m_timer = 0; /* transit to idle state */
 328                         in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
 329                 }
 330
 331                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 332                         mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
 333                 break;
 334         default:                /* this is impossible */
 335                 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
 336                 break;
 337         }
 338
 339         m_freem(m);
 340 }
 341
 342 void
 343 mld6_fasttimeo(void)
 344 {
 345         struct in6_multi *in6m;
 346         struct in6_multistep step;
 347
 348         /*
 349          * Quick check to see if any work needs to be done, in order
 350          * to minimize the overhead of fasttimo processing.
 351          */
 352         if (!mld6_timers_are_running)
 353                 return;
 354
 355         crit_enter();
 356         mld6_timers_are_running = 0;
 357         IN6_FIRST_MULTI(step, in6m);
 358         while (in6m != NULL) {
 359                 if (in6m->in6m_timer == 0) {
 360                         /* do nothing */
 361                 } else if (--in6m->in6m_timer == 0) {
 362                         mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
 363                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 364                 } else {
 365                         mld6_timers_are_running = 1;
 366                 }
 367                 IN6_NEXT_MULTI(step, in6m);
 368         }
 369         crit_exit();
 370 }
 371
 372 static void
 373 mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst)
 374 {
 375         struct mbuf *mh, *md;
 376         struct mld_hdr *mldh;
 377         struct ip6_hdr *ip6;
 378         struct ip6_moptions im6o;
 379         struct in6_ifaddr *ia;
 380         struct ifnet *ifp = in6m->in6m_ifp;
 381         struct ifnet *outif = NULL;
 382
 383         /*
 384          * At first, find a link local address on the outgoing interface
 385          * to use as the source address of the MLD packet.
 386          */
 387         if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
 388             == NULL)
 389                 return;
 390
 391         /*
 392          * Allocate mbufs to store ip6 header and MLD header.
 393          * We allocate 2 mbufs and make chain in advance because
 394          * it is more convenient when inserting the hop-by-hop option later.
 395          */
 396         MGETHDR(mh, MB_DONTWAIT, MT_HEADER);
 397         if (mh == NULL)
 398                 return;
 399         MGET(md, MB_DONTWAIT, MT_DATA);
 400         if (md == NULL) {
 401                 m_free(mh);
 402                 return;
 403         }
 404         mh->m_next = md;
 405
 406         mh->m_pkthdr.rcvif = NULL;
 407         mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
 408         mh->m_len = sizeof(struct ip6_hdr);
 409         MH_ALIGN(mh, sizeof(struct ip6_hdr));
 410
 411         /* fill in the ip6 header */
 412         ip6 = mtod(mh, struct ip6_hdr *);
 413         ip6->ip6_flow = 0;
 414         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 415         ip6->ip6_vfc |= IPV6_VERSION;
 416         /* ip6_plen will be set later */
 417         ip6->ip6_nxt = IPPROTO_ICMPV6;
 418         /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
 419         ip6->ip6_src = ia->ia_addr.sin6_addr;
 420         ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
 421
 422         /* fill in the MLD header */
 423         md->m_len = sizeof(struct mld_hdr);
 424         mldh = mtod(md, struct mld_hdr *);
 425         mldh->mld_type = type;
 426         mldh->mld_code = 0;
 427         mldh->mld_cksum = 0;
 428         /* XXX: we assume the function will not be called for query messages */
 429         mldh->mld_maxdelay = 0;
 430         mldh->mld_reserved = 0;
 431         mldh->mld_addr = in6m->in6m_addr;
 432         if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 433                 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
 434         mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
 435                                      sizeof(struct ip6_hdr),
 436                                      sizeof(struct mld_hdr));
 437
 438         /* construct multicast option */
 439         bzero(&im6o, sizeof(im6o));
 440         im6o.im6o_multicast_ifp = ifp;
 441         im6o.im6o_multicast_hlim = 1;
 442
 443         /*
 444          * Request loopback of the report if we are acting as a multicast
 445          * router, so that the process-level routing daemon can hear it.
 446          */
 447         im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
 448
 449         /* increment output statictics */
 450         icmp6stat.icp6s_outhist[type]++;
 451
 452         ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL);
 453         if (outif) {
 454                 icmp6_ifstat_inc(outif, ifs6_out_msg);
 455                 switch (type) {
 456                 case MLD_LISTENER_QUERY:
 457                         icmp6_ifstat_inc(outif, ifs6_out_mldquery);
 458                         break;
 459                 case MLD_LISTENER_REPORT:
 460                         icmp6_ifstat_inc(outif, ifs6_out_mldreport);
 461                         break;
 462                 case MLD_LISTENER_DONE:
 463                         icmp6_ifstat_inc(outif, ifs6_out_mlddone);
 464                         break;
 465                 }
 466         }
 467 }