561 lines
13 KiB
C
561 lines
13 KiB
C
/* $NetBSD: igmp.c,v 1.26 2001/07/25 00:13:16 enami Exp $ */
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/*
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* Copyright (C) 1995, 1996, 1997, and 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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* Internet Group Management Protocol (IGMP) routines.
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*
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* Written by Steve Deering, Stanford, May 1988.
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* Modified by Rosen Sharma, Stanford, Aug 1994.
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* Modified by Bill Fenner, Xerox PARC, Feb 1995.
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*
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* MULTICAST Revision: 1.3
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*/
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#include "opt_mrouting.h"
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#include <sys/param.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/systm.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/in_var.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/igmp.h>
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#include <netinet/igmp_var.h>
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#include <machine/stdarg.h>
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#define IP_MULTICASTOPTS 0
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int igmp_timers_are_running;
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static struct router_info *rti_head;
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void igmp_sendpkt __P((struct in_multi *, int));
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static int rti_fill __P((struct in_multi *));
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static struct router_info * rti_find __P((struct ifnet *));
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void
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igmp_init()
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{
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igmp_timers_are_running = 0;
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rti_head = 0;
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}
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static int
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rti_fill(inm)
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struct in_multi *inm;
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{
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struct router_info *rti;
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for (rti = rti_head; rti != 0; rti = rti->rti_next) {
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if (rti->rti_ifp == inm->inm_ifp) {
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inm->inm_rti = rti;
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if (rti->rti_type == IGMP_v1_ROUTER)
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return (IGMP_v1_HOST_MEMBERSHIP_REPORT);
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else
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return (IGMP_v2_HOST_MEMBERSHIP_REPORT);
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}
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}
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rti = (struct router_info *)malloc(sizeof(struct router_info),
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M_MRTABLE, M_NOWAIT);
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rti->rti_ifp = inm->inm_ifp;
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rti->rti_type = IGMP_v2_ROUTER;
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rti->rti_next = rti_head;
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rti_head = rti;
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inm->inm_rti = rti;
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return (IGMP_v2_HOST_MEMBERSHIP_REPORT);
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}
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static struct router_info *
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rti_find(ifp)
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struct ifnet *ifp;
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{
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struct router_info *rti;
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for (rti = rti_head; rti != 0; rti = rti->rti_next) {
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if (rti->rti_ifp == ifp)
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return (rti);
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}
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rti = (struct router_info *)malloc(sizeof(struct router_info),
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M_MRTABLE, M_NOWAIT);
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rti->rti_ifp = ifp;
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rti->rti_type = IGMP_v2_ROUTER;
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rti->rti_next = rti_head;
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rti_head = rti;
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return (rti);
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}
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void
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#if __STDC__
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igmp_input(struct mbuf *m, ...)
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#else
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igmp_input(m, va_alist)
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struct mbuf *m;
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va_dcl
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#endif
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{
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int proto;
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int iphlen;
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struct ifnet *ifp = m->m_pkthdr.rcvif;
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struct ip *ip = mtod(m, struct ip *);
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struct igmp *igmp;
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int minlen;
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struct in_multi *inm;
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struct in_multistep step;
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struct router_info *rti;
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struct in_ifaddr *ia;
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int timer;
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va_list ap;
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va_start(ap, m);
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iphlen = va_arg(ap, int);
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proto = va_arg(ap, int);
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va_end(ap);
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++igmpstat.igps_rcv_total;
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/*
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* Validate lengths
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*/
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minlen = iphlen + IGMP_MINLEN;
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if (ip->ip_len < minlen) {
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++igmpstat.igps_rcv_tooshort;
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m_freem(m);
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return;
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}
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if (((m->m_flags & M_EXT) && (ip->ip_src.s_addr & IN_CLASSA_NET) == 0)
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|| m->m_len < minlen) {
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if ((m = m_pullup(m, minlen)) == 0) {
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++igmpstat.igps_rcv_tooshort;
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return;
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}
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ip = mtod(m, struct ip *);
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}
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/*
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* Validate checksum
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*/
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m->m_data += iphlen;
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m->m_len -= iphlen;
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igmp = mtod(m, struct igmp *);
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if (in_cksum(m, ip->ip_len - iphlen)) {
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++igmpstat.igps_rcv_badsum;
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m_freem(m);
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return;
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}
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m->m_data -= iphlen;
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m->m_len += iphlen;
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switch (igmp->igmp_type) {
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case IGMP_HOST_MEMBERSHIP_QUERY:
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++igmpstat.igps_rcv_queries;
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if (ifp->if_flags & IFF_LOOPBACK)
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break;
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if (igmp->igmp_code == 0) {
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rti = rti_find(ifp);
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rti->rti_type = IGMP_v1_ROUTER;
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rti->rti_age = 0;
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if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) {
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++igmpstat.igps_rcv_badqueries;
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m_freem(m);
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return;
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}
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/*
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* Start the timers in all of our membership records
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* for the interface on which the query arrived,
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* except those that are already running and those
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* that belong to a "local" group (224.0.0.X).
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*/
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IN_FIRST_MULTI(step, inm);
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while (inm != NULL) {
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if (inm->inm_ifp == ifp &&
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inm->inm_timer == 0 &&
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!IN_LOCAL_GROUP(inm->inm_addr.s_addr)) {
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inm->inm_state = IGMP_DELAYING_MEMBER;
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inm->inm_timer = IGMP_RANDOM_DELAY(
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IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ);
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igmp_timers_are_running = 1;
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}
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IN_NEXT_MULTI(step, inm);
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}
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} else {
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if (!IN_MULTICAST(ip->ip_dst.s_addr)) {
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++igmpstat.igps_rcv_badqueries;
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m_freem(m);
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return;
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}
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timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
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if (timer == 0)
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timer =1;
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/*
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* Start the timers in all of our membership records
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* for the interface on which the query arrived,
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* except those that are already running and those
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* that belong to a "local" group (224.0.0.X). For
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* timers already running, check if they need to be
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* reset.
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*/
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IN_FIRST_MULTI(step, inm);
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while (inm != NULL) {
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if (inm->inm_ifp == ifp &&
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!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
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(ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP ||
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in_hosteq(ip->ip_dst, inm->inm_addr))) {
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switch (inm->inm_state) {
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case IGMP_DELAYING_MEMBER:
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if (inm->inm_timer <= timer)
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break;
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/* FALLTHROUGH */
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case IGMP_IDLE_MEMBER:
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case IGMP_LAZY_MEMBER:
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case IGMP_AWAKENING_MEMBER:
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inm->inm_state =
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IGMP_DELAYING_MEMBER;
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inm->inm_timer =
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IGMP_RANDOM_DELAY(timer);
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igmp_timers_are_running = 1;
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break;
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case IGMP_SLEEPING_MEMBER:
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inm->inm_state =
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IGMP_AWAKENING_MEMBER;
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break;
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}
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}
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IN_NEXT_MULTI(step, inm);
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}
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}
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break;
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case IGMP_v1_HOST_MEMBERSHIP_REPORT:
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++igmpstat.igps_rcv_reports;
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if (ifp->if_flags & IFF_LOOPBACK)
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break;
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if (!IN_MULTICAST(igmp->igmp_group.s_addr) ||
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!in_hosteq(igmp->igmp_group, ip->ip_dst)) {
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++igmpstat.igps_rcv_badreports;
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m_freem(m);
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return;
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}
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/*
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* KLUDGE: if the IP source address of the report has an
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* unspecified (i.e., zero) subnet number, as is allowed for
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* a booting host, replace it with the correct subnet number
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* so that a process-level multicast routing daemon can
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* determine which subnet it arrived from. This is necessary
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* to compensate for the lack of any way for a process to
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* determine the arrival interface of an incoming packet.
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*/
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if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) {
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IFP_TO_IA(ifp, ia); /* XXX */
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if (ia)
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ip->ip_src.s_addr = ia->ia_subnet;
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}
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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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IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
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if (inm != NULL) {
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inm->inm_timer = 0;
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++igmpstat.igps_rcv_ourreports;
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switch (inm->inm_state) {
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case IGMP_IDLE_MEMBER:
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case IGMP_LAZY_MEMBER:
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case IGMP_AWAKENING_MEMBER:
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case IGMP_SLEEPING_MEMBER:
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inm->inm_state = IGMP_SLEEPING_MEMBER;
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break;
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case IGMP_DELAYING_MEMBER:
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if (inm->inm_rti->rti_type == IGMP_v1_ROUTER)
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inm->inm_state = IGMP_LAZY_MEMBER;
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else
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inm->inm_state = IGMP_SLEEPING_MEMBER;
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break;
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}
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}
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break;
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case IGMP_v2_HOST_MEMBERSHIP_REPORT:
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#ifdef MROUTING
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/*
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* Make sure we don't hear our own membership report. Fast
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* leave requires knowing that we are the only member of a
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* group.
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*/
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IFP_TO_IA(ifp, ia); /* XXX */
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if (ia && in_hosteq(ip->ip_src, ia->ia_addr.sin_addr))
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break;
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#endif
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++igmpstat.igps_rcv_reports;
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if (ifp->if_flags & IFF_LOOPBACK)
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break;
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if (!IN_MULTICAST(igmp->igmp_group.s_addr) ||
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!in_hosteq(igmp->igmp_group, ip->ip_dst)) {
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++igmpstat.igps_rcv_badreports;
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m_freem(m);
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return;
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}
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/*
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* KLUDGE: if the IP source address of the report has an
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* unspecified (i.e., zero) subnet number, as is allowed for
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* a booting host, replace it with the correct subnet number
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* so that a process-level multicast routing daemon can
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* determine which subnet it arrived from. This is necessary
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* to compensate for the lack of any way for a process to
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* determine the arrival interface of an incoming packet.
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*/
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if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) {
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#ifndef MROUTING
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IFP_TO_IA(ifp, ia); /* XXX */
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#endif
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if (ia)
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ip->ip_src.s_addr = ia->ia_subnet;
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}
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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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IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
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if (inm != NULL) {
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inm->inm_timer = 0;
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++igmpstat.igps_rcv_ourreports;
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switch (inm->inm_state) {
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case IGMP_DELAYING_MEMBER:
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case IGMP_IDLE_MEMBER:
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case IGMP_AWAKENING_MEMBER:
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inm->inm_state = IGMP_LAZY_MEMBER;
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break;
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case IGMP_LAZY_MEMBER:
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case IGMP_SLEEPING_MEMBER:
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break;
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}
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}
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break;
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}
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/*
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* Pass all valid IGMP packets up to any process(es) listening
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* on a raw IGMP socket.
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*/
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rip_input(m, iphlen, proto);
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return;
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}
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void
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igmp_joingroup(inm)
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struct in_multi *inm;
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{
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int s = splsoftnet();
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inm->inm_state = IGMP_IDLE_MEMBER;
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if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
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(inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) {
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igmp_sendpkt(inm, rti_fill(inm));
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inm->inm_state = IGMP_DELAYING_MEMBER;
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inm->inm_timer = IGMP_RANDOM_DELAY(
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IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ);
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igmp_timers_are_running = 1;
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} else
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inm->inm_timer = 0;
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splx(s);
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}
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void
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igmp_leavegroup(inm)
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struct in_multi *inm;
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{
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switch (inm->inm_state) {
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case IGMP_DELAYING_MEMBER:
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case IGMP_IDLE_MEMBER:
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if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
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(inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0)
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if (inm->inm_rti->rti_type != IGMP_v1_ROUTER)
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igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE);
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break;
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case IGMP_LAZY_MEMBER:
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case IGMP_AWAKENING_MEMBER:
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case IGMP_SLEEPING_MEMBER:
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break;
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}
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}
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void
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igmp_fasttimo()
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{
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struct in_multi *inm;
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struct in_multistep step;
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int s;
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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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*/
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if (!igmp_timers_are_running)
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return;
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s = splsoftnet();
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igmp_timers_are_running = 0;
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IN_FIRST_MULTI(step, inm);
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while (inm != NULL) {
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if (inm->inm_timer == 0) {
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/* do nothing */
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} else if (--inm->inm_timer == 0) {
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if (inm->inm_state == IGMP_DELAYING_MEMBER) {
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if (inm->inm_rti->rti_type == IGMP_v1_ROUTER)
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igmp_sendpkt(inm,
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IGMP_v1_HOST_MEMBERSHIP_REPORT);
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else
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igmp_sendpkt(inm,
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IGMP_v2_HOST_MEMBERSHIP_REPORT);
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inm->inm_state = IGMP_IDLE_MEMBER;
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}
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} else {
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igmp_timers_are_running = 1;
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}
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IN_NEXT_MULTI(step, inm);
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}
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splx(s);
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}
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void
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igmp_slowtimo()
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{
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struct router_info *rti;
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int s;
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s = splsoftnet();
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for (rti = rti_head; rti != 0; rti = rti->rti_next) {
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if (rti->rti_type == IGMP_v1_ROUTER &&
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++rti->rti_age >= IGMP_AGE_THRESHOLD) {
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rti->rti_type = IGMP_v2_ROUTER;
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}
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}
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splx(s);
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}
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void
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igmp_sendpkt(inm, type)
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struct in_multi *inm;
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int type;
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{
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struct mbuf *m;
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struct igmp *igmp;
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struct ip *ip;
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struct ip_moptions imo;
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#ifdef MROUTING
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extern struct socket *ip_mrouter;
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#endif /* MROUTING */
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MGETHDR(m, M_DONTWAIT, MT_HEADER);
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if (m == NULL)
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return;
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/*
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* Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN
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* is smaller than mbuf size returned by MGETHDR.
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*/
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m->m_data += max_linkhdr;
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m->m_len = sizeof(struct ip) + IGMP_MINLEN;
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m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
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ip = mtod(m, struct ip *);
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ip->ip_tos = 0;
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ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
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ip->ip_off = 0;
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ip->ip_p = IPPROTO_IGMP;
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ip->ip_src = zeroin_addr;
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ip->ip_dst = inm->inm_addr;
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m->m_data += sizeof(struct ip);
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m->m_len -= sizeof(struct ip);
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igmp = mtod(m, struct igmp *);
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igmp->igmp_type = type;
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igmp->igmp_code = 0;
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igmp->igmp_group = inm->inm_addr;
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igmp->igmp_cksum = 0;
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igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
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m->m_data -= sizeof(struct ip);
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m->m_len += sizeof(struct ip);
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imo.imo_multicast_ifp = inm->inm_ifp;
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imo.imo_multicast_ttl = 1;
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#ifdef RSVP_ISI
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imo.imo_multicast_vif = -1;
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#endif
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/*
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* Request loopback of the report if we are acting as a multicast
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* router, so that the process-level routing demon can hear it.
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*/
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#ifdef MROUTING
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imo.imo_multicast_loop = (ip_mrouter != NULL);
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#else
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imo.imo_multicast_loop = 0;
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#endif /* MROUTING */
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ip_output(m, (struct mbuf *)0, (struct route *)0, IP_MULTICASTOPTS,
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&imo);
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++igmpstat.igps_snd_reports;
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}
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