473 lines
15 KiB
C
473 lines
15 KiB
C
/* $OpenBSD: mld6.c,v 1.62 2024/02/13 12:22:09 bluhm Exp $ */
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/* $KAME: mld6.c,v 1.26 2001/02/16 14:50:35 itojun Exp $ */
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/*
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* Copyright (C) 1998 WIDE Project.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* Copyright (c) 1988 Stephen Deering.
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Stephen Deering of Stanford University.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)igmp.c 8.1 (Berkeley) 7/19/93
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/protosw.h>
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#include <sys/syslog.h>
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#include <net/if.h>
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#include <net/if_var.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet6/in6_var.h>
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#include <netinet/ip6.h>
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#include <netinet6/ip6_var.h>
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#include <netinet/icmp6.h>
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#include <netinet6/mld6.h>
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#include <netinet6/mld6_var.h>
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static struct ip6_pktopts ip6_opts;
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int mld6_timers_are_running; /* [N] shortcut for fast timer */
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void mld6_checktimer(struct ifnet *);
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static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
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void
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mld6_init(void)
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{
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static u_int8_t hbh_buf[8];
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struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
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u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
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mld6_timers_are_running = 0;
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/* ip6h_nxt will be fill in later */
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hbh->ip6h_len = 0; /* (8 >> 3) - 1 */
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/* XXX: grotty hard coding... */
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hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */
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hbh_buf[3] = 0;
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hbh_buf[4] = IP6OPT_ROUTER_ALERT;
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hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
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memcpy(&hbh_buf[6], (caddr_t)&rtalert_code, sizeof(u_int16_t));
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ip6_initpktopts(&ip6_opts);
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ip6_opts.ip6po_hbh = hbh;
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}
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void
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mld6_start_listening(struct in6_multi *in6m)
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{
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/* XXX: These are necessary for KAME's link-local hack */
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struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
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/*
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* RFC2710 page 10:
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* The node never sends a Report or Done for the link-scope all-nodes
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* address.
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* MLD messages are never sent for multicast addresses whose scope is 0
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* (reserved) or 1 (node-local).
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*/
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all_nodes.s6_addr16[1] = htons(in6m->in6m_ifidx);
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if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes) ||
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__IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
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__IPV6_ADDR_SCOPE_LINKLOCAL) {
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in6m->in6m_timer = 0;
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in6m->in6m_state = MLD_OTHERLISTENER;
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} else {
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mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
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in6m->in6m_timer =
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MLD_RANDOM_DELAY(MLD_V1_MAX_RI *
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PR_FASTHZ);
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in6m->in6m_state = MLD_IREPORTEDLAST;
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mld6_timers_are_running = 1;
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}
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}
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void
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mld6_stop_listening(struct in6_multi *in6m)
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{
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/* XXX: These are necessary for KAME's link-local hack */
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struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
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struct in6_addr all_routers = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
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all_nodes.s6_addr16[1] = htons(in6m->in6m_ifidx);
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/* XXX: necessary when mrouting */
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all_routers.s6_addr16[1] = htons(in6m->in6m_ifidx);
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if (in6m->in6m_state == MLD_IREPORTEDLAST &&
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(!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes)) &&
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__IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) >
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__IPV6_ADDR_SCOPE_INTFACELOCAL)
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mld6_sendpkt(in6m, MLD_LISTENER_DONE, &all_routers);
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}
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void
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mld6_input(struct mbuf *m, int off)
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{
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struct ip6_hdr *ip6;
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struct mld_hdr *mldh;
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struct ifnet *ifp;
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struct in6_multi *in6m;
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struct ifmaddr *ifma;
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int timer; /* timer value in the MLD query header */
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/* XXX: These are necessary for KAME's link-local hack */
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struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
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IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
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if (mldh == NULL) {
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icmp6stat_inc(icp6s_tooshort);
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return;
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}
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/* source address validation */
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ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */
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if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
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#if 0
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char src[INET6_ADDRSTRLEN], grp[INET6_ADDRSTRLEN];
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log(LOG_ERR,
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"mld_input: src %s is not link-local (grp=%s)\n",
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inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)),
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inet_ntop(AF_INET6, &mldh->mld_addr, grp, sizeof(grp)));
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#endif
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/*
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* spec (RFC2710) does not explicitly
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* specify to discard the packet from a non link-local
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* source address. But we believe it's expected to do so.
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*/
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m_freem(m);
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return;
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}
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ifp = if_get(m->m_pkthdr.ph_ifidx);
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if (ifp == NULL) {
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m_freem(m);
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return;
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}
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/*
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* In the MLD6 specification, there are 3 states and a flag.
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*
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* In Non-Listener state, we simply don't have a membership record.
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* In Delaying Listener state, our timer is running (in6m->in6m_timer)
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* In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
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*
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* The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if
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* we have heard a report from another member, or MLD_IREPORTEDLAST
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* if we sent the last report.
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*/
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switch(mldh->mld_type) {
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case MLD_LISTENER_QUERY:
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if (ifp->if_flags & IFF_LOOPBACK)
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break;
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if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
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!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
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break; /* print error or log stat? */
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if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
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mldh->mld_addr.s6_addr16[1] =
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htons(ifp->if_index); /* XXX */
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/*
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* - Start the timers in all of our membership records
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* that the query applies to for the interface on
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* which the query arrived excl. those that belong
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* to the "all-nodes" group (ff02::1).
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* - Restart any timer that is already running but has
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* A value longer than the requested timeout.
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* - Use the value specified in the query message as
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* the maximum timeout.
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*/
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/*
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* XXX: System timer resolution is too low to handle Max
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* Response Delay, so set 1 to the internal timer even if
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* the calculated value equals to zero when Max Response
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* Delay is positive.
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*/
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timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE;
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if (timer == 0 && mldh->mld_maxdelay)
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timer = 1;
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all_nodes.s6_addr16[1] = htons(ifp->if_index);
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TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) {
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if (ifma->ifma_addr->sa_family != AF_INET6)
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continue;
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in6m = ifmatoin6m(ifma);
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if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes) ||
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__IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
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__IPV6_ADDR_SCOPE_LINKLOCAL)
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continue;
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if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) ||
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IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
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&in6m->in6m_addr))
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{
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if (timer == 0) {
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/* send a report immediately */
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mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
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NULL);
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in6m->in6m_timer = 0; /* reset timer */
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in6m->in6m_state = MLD_IREPORTEDLAST;
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} else if (in6m->in6m_timer == 0 || /* idle */
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in6m->in6m_timer > timer) {
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in6m->in6m_timer =
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MLD_RANDOM_DELAY(timer);
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mld6_timers_are_running = 1;
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}
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}
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}
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if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
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mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
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break;
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case MLD_LISTENER_REPORT:
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/*
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* For fast leave to work, we have to know that we are the
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* last person to send a report for this group. Reports
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* can potentially get looped back if we are a multicast
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* router, so discard reports sourced by me.
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* Note that it is impossible to check IFF_LOOPBACK flag of
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* ifp for this purpose, since ip6_mloopback pass the physical
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* interface to if_input_local().
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*/
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if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
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break;
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if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
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break;
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if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
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mldh->mld_addr.s6_addr16[1] =
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htons(ifp->if_index); /* XXX */
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/*
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* If we belong to the group being reported, stop
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* our timer for that group.
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*/
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IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m);
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if (in6m) {
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in6m->in6m_timer = 0; /* transit to idle state */
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in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */
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}
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if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
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mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
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break;
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default: /* this is impossible */
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#if 0
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/*
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* this case should be impossible because of filtering in
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* icmp6_input(). But we explicitly disabled this part
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* just in case.
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*/
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log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld_type);
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#endif
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break;
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}
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if_put(ifp);
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m_freem(m);
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}
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void
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mld6_fasttimeo(void)
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{
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struct ifnet *ifp;
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/*
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* Quick check to see if any work needs to be done, in order
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* to minimize the overhead of fasttimo processing.
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* Variable mld6_timers_are_running is read atomically, but without
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* lock intentionally. In case it is not set due to MP races, we may
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* miss to check the timers. Then run the loop at next fast timeout.
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*/
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if (!mld6_timers_are_running)
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return;
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NET_LOCK();
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mld6_timers_are_running = 0;
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TAILQ_FOREACH(ifp, &ifnetlist, if_list)
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mld6_checktimer(ifp);
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NET_UNLOCK();
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}
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void
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mld6_checktimer(struct ifnet *ifp)
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{
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struct in6_multi *in6m;
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struct ifmaddr *ifma;
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NET_ASSERT_LOCKED();
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TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) {
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if (ifma->ifma_addr->sa_family != AF_INET6)
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continue;
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in6m = ifmatoin6m(ifma);
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if (in6m->in6m_timer == 0) {
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/* do nothing */
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} else if (--in6m->in6m_timer == 0) {
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mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
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in6m->in6m_state = MLD_IREPORTEDLAST;
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} else {
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mld6_timers_are_running = 1;
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}
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}
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}
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static void
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mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst)
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{
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struct mbuf *mh, *md;
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struct mld_hdr *mldh;
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struct ip6_hdr *ip6;
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struct ip6_moptions im6o;
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struct in6_ifaddr *ia6;
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struct ifnet *ifp;
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int ignflags;
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ifp = if_get(in6m->in6m_ifidx);
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if (ifp == NULL)
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return;
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/*
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* At first, find a link local address on the outgoing interface
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* to use as the source address of the MLD packet.
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* We do not reject tentative addresses for MLD report to deal with
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* the case where we first join a link-local address.
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*/
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ignflags = IN6_IFF_DUPLICATED|IN6_IFF_ANYCAST;
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if ((ia6 = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) {
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if_put(ifp);
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return;
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}
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if ((ia6->ia6_flags & IN6_IFF_TENTATIVE))
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ia6 = NULL;
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/*
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* Allocate mbufs to store ip6 header and MLD header.
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* We allocate 2 mbufs and make chain in advance because
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* it is more convenient when inserting the hop-by-hop option later.
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*/
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MGETHDR(mh, M_DONTWAIT, MT_HEADER);
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if (mh == NULL) {
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if_put(ifp);
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return;
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}
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MGET(md, M_DONTWAIT, MT_DATA);
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if (md == NULL) {
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m_free(mh);
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if_put(ifp);
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return;
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}
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mh->m_next = md;
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mh->m_pkthdr.ph_ifidx = 0;
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mh->m_pkthdr.ph_rtableid = ifp->if_rdomain;
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mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
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mh->m_len = sizeof(struct ip6_hdr);
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m_align(mh, sizeof(struct ip6_hdr));
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/* fill in the ip6 header */
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ip6 = mtod(mh, struct ip6_hdr *);
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ip6->ip6_flow = 0;
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ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
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ip6->ip6_vfc |= IPV6_VERSION;
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/* ip6_plen will be set later */
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ip6->ip6_nxt = IPPROTO_ICMPV6;
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/* ip6_hlim will be set by im6o.im6o_hlim */
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ip6->ip6_src = ia6 ? ia6->ia_addr.sin6_addr : in6addr_any;
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ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
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/* fill in the MLD header */
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md->m_len = sizeof(struct mld_hdr);
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mldh = mtod(md, struct mld_hdr *);
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mldh->mld_type = type;
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mldh->mld_code = 0;
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mldh->mld_cksum = 0;
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/* XXX: we assume the function will not be called for query messages */
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mldh->mld_maxdelay = 0;
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mldh->mld_reserved = 0;
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mldh->mld_addr = in6m->in6m_addr;
|
|
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
|
|
mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
|
|
mh->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT;
|
|
|
|
/* construct multicast option */
|
|
bzero(&im6o, sizeof(im6o));
|
|
im6o.im6o_ifidx = ifp->if_index;
|
|
im6o.im6o_hlim = 1;
|
|
|
|
/*
|
|
* Request loopback of the report if we are acting as a multicast
|
|
* router, so that the process-level routing daemon can hear it.
|
|
*/
|
|
#ifdef MROUTING
|
|
im6o.im6o_loop = (ip6_mrouter[ifp->if_rdomain] != NULL);
|
|
#endif
|
|
if_put(ifp);
|
|
|
|
icmp6stat_inc(icp6s_outhist + type);
|
|
ip6_output(mh, &ip6_opts, NULL, ia6 ? 0 : IPV6_UNSPECSRC, &im6o,
|
|
NULL);
|
|
}
|