mld6.c

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    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. Neither the name of the University nor the names of its contributors
   51  *    may be used to endorse or promote products derived from this software
   52  *    without specific prior written permission.
   53  *
   54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   64  * SUCH DAMAGE.
   65  *
   66  *      @(#)igmp.c      8.1 (Berkeley) 7/19/93
   67  */
   68 
   69 #include "opt_inet.h"
   70 #include "opt_inet6.h"
   71 
   72 #include <sys/param.h>
   73 #include <sys/systm.h>
   74 #include <sys/mbuf.h>
   75 #include <sys/socket.h>
   76 #include <sys/protosw.h>
   77 #include <sys/syslog.h>
   78 #include <sys/thread2.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 (struct in6_multi *, int, const struct in6_addr *);
  110 
  111 static struct lwkt_token mld6_token = LWKT_TOKEN_INITIALIZER(mp_token);
  112 
  113 
  114 void
  115 mld6_init(void)
  116 {
  117         static u_int8_t hbh_buf[8];
  118         struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
  119         u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
  120 
  121         mld6_timers_are_running = 0;
  122 
  123         /* ip6h_nxt will be fill in later */
  124         hbh->ip6h_len = 0;      /* (8 >> 3) - 1 */
  125 
  126         /* XXX: grotty hard coding... */
  127         hbh_buf[2] = IP6OPT_PADN;       /* 2 byte padding */
  128         hbh_buf[3] = 0;
  129         hbh_buf[4] = IP6OPT_RTALERT;
  130         hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
  131         bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
  132 
  133         init_ip6pktopts(&ip6_opts);
  134         ip6_opts.ip6po_hbh = hbh;
  135 }
  136 
  137 void
  138 mld6_start_listening(struct in6_multi *in6m)
  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         lwkt_gettoken(&mld6_token);
  148         mld6_all_nodes_linklocal.s6_addr16[1] =
  149                 htons(in6m->in6m_ifp->if_index); /* XXX */
  150         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
  151             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
  152                 in6m->in6m_timer = 0;
  153                 in6m->in6m_state = MLD6_OTHERLISTENER;
  154         } else {
  155                 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
  156                 in6m->in6m_timer = MLD6_RANDOM_DELAY(
  157                         MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
  158                 in6m->in6m_state = MLD6_IREPORTEDLAST;
  159                 mld6_timers_are_running = 1;
  160         }
  161         lwkt_reltoken(&mld6_token);
  162 }
  163 
  164 void
  165 mld6_stop_listening(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, MLD_LISTENER_DONE,
  176                              &mld6_all_routers_linklocal);
  177 }
  178 
  179 void
  180 mld6_input(struct mbuf *m, int off)
  181 {
  182         struct ip6_hdr *ip6;
  183         struct mld_hdr *mldh;
  184         struct ifnet *ifp = m->m_pkthdr.rcvif;
  185         struct in6_multi *in6m;
  186         struct in6_ifaddr *ia;
  187         struct ifmultiaddr *ifma;
  188         int timer;              /* timer value in the MLD query header */
  189 
  190 #ifndef PULLDOWN_TEST
  191         IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
  192         mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
  193 #else
  194         IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
  195         if (mldh == NULL) {
  196                 icmp6stat.icp6s_tooshort++;
  197                 return;
  198         }
  199 #endif
  200 
  201         lwkt_gettoken(&mld6_token);
  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                 lwkt_reltoken(&mld6_token);
  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->mld_type) {
  232         case MLD_LISTENER_QUERY:
  233                 if (ifp->if_flags & IFF_LOOPBACK)
  234                         break;
  235 
  236                 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
  237                     !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
  238                         break;  /* print error or log stat? */
  239                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
  240                         mldh->mld_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->mld_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
  264                 if (timer == 0 && mldh->mld_maxdelay)
  265                         timer = 1;
  266                 mld6_all_nodes_linklocal.s6_addr16[1] =
  267                         htons(ifp->if_index); /* XXX */
  268                 
  269                 TAILQ_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->mld_addr) ||
  281                             IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
  282                                                 &in6m->in6m_addr))
  283                         {
  284                                 if (timer == 0) {
  285                                         /* send a report immediately */
  286                                         mld6_sendpkt(in6m, MLD_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->mld_addr))
  301                         mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
  302                 break;
  303         case MLD_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->mld_addr))
  317                         break;
  318 
  319                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
  320                         mldh->mld_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->mld_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->mld_addr))
  333                         mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
  334                 break;
  335         default:                /* this is impossible */
  336                 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
  337                 break;
  338         }
  339 
  340         m_freem(m);
  341         lwkt_reltoken(&mld6_token);
  342 }
  343 
  344 void
  345 mld6_fasttimeo(void)
  346 {
  347         struct in6_multi *in6m;
  348         struct in6_multistep step;
  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         lwkt_gettoken(&mld6_token);
  355         if (!mld6_timers_are_running) {
  356                 lwkt_reltoken(&mld6_token);
  357                 return;
  358         }
  359 
  360         mld6_timers_are_running = 0;
  361         IN6_FIRST_MULTI(step, in6m);
  362         while (in6m != NULL) {
  363                 if (in6m->in6m_timer == 0) {
  364                         /* do nothing */
  365                 } else if (--in6m->in6m_timer == 0) {
  366                         mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
  367                         in6m->in6m_state = MLD6_IREPORTEDLAST;
  368                 } else {
  369                         mld6_timers_are_running = 1;
  370                 }
  371                 IN6_NEXT_MULTI(step, in6m);
  372         }
  373         lwkt_reltoken(&mld6_token);
  374 }
  375 
  376 static void
  377 mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst)
  378 {
  379         struct mbuf *mh, *md;
  380         struct mld_hdr *mldh;
  381         struct ip6_hdr *ip6;
  382         struct ip6_moptions im6o;
  383         struct in6_ifaddr *ia;
  384         struct ifnet *ifp = in6m->in6m_ifp;
  385         struct ifnet *outif = NULL;
  386 
  387         /*
  388          * At first, find a link local address on the outgoing interface
  389          * to use as the source address of the MLD packet.
  390          */
  391         if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
  392             == NULL)
  393                 return;
  394 
  395         /*
  396          * Allocate mbufs to store ip6 header and MLD header.
  397          * We allocate 2 mbufs and make chain in advance because
  398          * it is more convenient when inserting the hop-by-hop option later.
  399          */
  400         MGETHDR(mh, MB_DONTWAIT, MT_HEADER);
  401         if (mh == NULL)
  402                 return;
  403         MGET(md, MB_DONTWAIT, MT_DATA);
  404         if (md == NULL) {
  405                 m_free(mh);
  406                 return;
  407         }
  408         mh->m_next = md;
  409 
  410         mh->m_pkthdr.rcvif = NULL;
  411         mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
  412         mh->m_len = sizeof(struct ip6_hdr);
  413         MH_ALIGN(mh, sizeof(struct ip6_hdr));
  414 
  415         /* fill in the ip6 header */
  416         ip6 = mtod(mh, struct ip6_hdr *);
  417         ip6->ip6_flow = 0;
  418         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  419         ip6->ip6_vfc |= IPV6_VERSION;
  420         /* ip6_plen will be set later */
  421         ip6->ip6_nxt = IPPROTO_ICMPV6;
  422         /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
  423         ip6->ip6_src = ia->ia_addr.sin6_addr;
  424         ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
  425 
  426         /* fill in the MLD header */
  427         md->m_len = sizeof(struct mld_hdr);
  428         mldh = mtod(md, struct mld_hdr *);
  429         mldh->mld_type = type;
  430         mldh->mld_code = 0;
  431         mldh->mld_cksum = 0;
  432         /* XXX: we assume the function will not be called for query messages */
  433         mldh->mld_maxdelay = 0;
  434         mldh->mld_reserved = 0;
  435         mldh->mld_addr = in6m->in6m_addr;
  436         if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
  437                 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
  438         mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
  439                                      sizeof(struct ip6_hdr),
  440                                      sizeof(struct mld_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, NULL);
  457         if (outif) {
  458                 icmp6_ifstat_inc(outif, ifs6_out_msg);
  459                 switch (type) {
  460                 case MLD_LISTENER_QUERY:
  461                         icmp6_ifstat_inc(outif, ifs6_out_mldquery);
  462                         break;
  463                 case MLD_LISTENER_REPORT:
  464                         icmp6_ifstat_inc(outif, ifs6_out_mldreport);
  465                         break;
  466                 case MLD_LISTENER_DONE:
  467                         icmp6_ifstat_inc(outif, ifs6_out_mlddone);
  468                         break;
  469                 }
  470         }
  471 }
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FreeBSD/Linux Kernel Cross Reference sys/netinet6/mld6.c

FreeBSD/Linux Kernel Cross Reference
sys/netinet6/mld6.c
