[apple/xnu.git] / bsd / netinet / igmp.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1988 Stephen Deering.
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Stephen Deering of Stanford University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)igmp.c	8.1 (Berkeley) 7/19/93
 */

/*
 * Internet Group Management Protocol (IGMP) routines.
 *
 * Written by Steve Deering, Stanford, May 1988.
 * Modified by Rosen Sharma, Stanford, Aug 1994.
 * Modified by Bill Fenner, Xerox PARC, Feb 1995.
 * Modified to fully comply to IGMPv2 by Bill Fenner, Oct 1995.
 *
 * MULTICAST Revision: 3.5.1.4
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/igmp.h>
#include <netinet/igmp_var.h>

#ifndef __APPLE__
static MALLOC_DEFINE(M_IGMP, "igmp", "igmp state");
#endif

static struct router_info *
		find_rti __P((struct ifnet *ifp));

static struct igmpstat igmpstat;

SYSCTL_STRUCT(_net_inet_igmp, IGMPCTL_STATS, stats, CTLFLAG_RD,
	&igmpstat, igmpstat, "");

static int igmp_timers_are_running;
static u_long igmp_all_hosts_group;
static u_long igmp_all_rtrs_group;
static struct mbuf *router_alert;
static struct router_info *Head;

static void igmp_sendpkt __P((struct in_multi *, int, unsigned long));

void
igmp_init()
{
	struct ipoption *ra;

	/*
	 * To avoid byte-swapping the same value over and over again.
	 */
	igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
	igmp_all_rtrs_group = htonl(INADDR_ALLRTRS_GROUP);

	igmp_timers_are_running = 0;

	/*
	 * Construct a Router Alert option to use in outgoing packets
	 */
	MGET(router_alert, M_DONTWAIT, MT_DATA);
	ra = mtod(router_alert, struct ipoption *);
	ra->ipopt_dst.s_addr = 0;
	ra->ipopt_list[0] = IPOPT_RA;	/* Router Alert Option */
	ra->ipopt_list[1] = 0x04;	/* 4 bytes long */
	ra->ipopt_list[2] = 0x00;
	ra->ipopt_list[3] = 0x00;
	router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1];

	Head = (struct router_info *) 0;
}

static struct router_info *
find_rti(ifp)
	struct ifnet *ifp;
{
        register struct router_info *rti = Head;

#if IGMP_DEBUG
	printf("[igmp.c, _find_rti] --> entering \n");
#endif
        while (rti) {
                if (rti->rti_ifp == ifp) {
#if IGMP_DEBUG
			printf("[igmp.c, _find_rti] --> found old entry \n");
#endif
                        return rti;
                }
                rti = rti->rti_next;
        }

	MALLOC(rti, struct router_info *, sizeof *rti, M_IGMP, M_NOWAIT);
        rti->rti_ifp = ifp;
        rti->rti_type = IGMP_V2_ROUTER;
        rti->rti_time = 0;
        rti->rti_next = Head;
        Head = rti;
#if IGMP_DEBUG
	printf("[igmp.c, _find_rti] --> created an entry \n");
#endif
        return rti;
}

void
igmp_input(m, iphlen)
	register struct mbuf *m;
	register int iphlen;
{
	register struct igmp *igmp;
	register struct ip *ip;
	register int igmplen;
	register struct ifnet *ifp = m->m_pkthdr.rcvif;
	register int minlen;
	register struct in_multi *inm;
	register struct in_ifaddr *ia;
	struct in_multistep step;
	struct router_info *rti;
	
	int timer; /** timer value in the igmp query header **/

	++igmpstat.igps_rcv_total;

	ip = mtod(m, struct ip *);
	igmplen = ip->ip_len;

	/*
	 * Validate lengths
	 */
	if (igmplen < IGMP_MINLEN) {
		++igmpstat.igps_rcv_tooshort;
		m_freem(m);
		return;
	}
	minlen = iphlen + IGMP_MINLEN;
	if ((m->m_flags & M_EXT || m->m_len < minlen) &&
	    (m = m_pullup(m, minlen)) == 0) {
		++igmpstat.igps_rcv_tooshort;
		return;
	}

	/*
	 * Validate checksum
	 */
	m->m_data += iphlen;
	m->m_len -= iphlen;
	igmp = mtod(m, struct igmp *);
	if (in_cksum(m, igmplen)) {
		++igmpstat.igps_rcv_badsum;
		m_freem(m);
		return;
	}
	m->m_data -= iphlen;
	m->m_len += iphlen;

	ip = mtod(m, struct ip *);
	timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
	if (timer == 0)
		timer = 1;
	rti = find_rti(ifp);

	/*
	 * In the IGMPv2 specification, there are 3 states and a flag.
	 *
	 * In Non-Member state, we simply don't have a membership record.
	 * In Delaying Member state, our timer is running (inm->inm_timer)
	 * In Idle Member state, our timer is not running (inm->inm_timer==0)
	 *
	 * The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
	 * we have heard a report from another member, or IGMP_IREPORTEDLAST
	 * if I sent the last report.
	 */
	switch (igmp->igmp_type) {

	case IGMP_MEMBERSHIP_QUERY:
		++igmpstat.igps_rcv_queries;

		if (ifp->if_flags & IFF_LOOPBACK)
			break;

		if (igmp->igmp_code == 0) {
			/*
			 * Old router.  Remember that the querier on this
			 * interface is old, and set the timer to the
			 * value in RFC 1112.
			 */

			rti->rti_type = IGMP_V1_ROUTER;
			rti->rti_time = 0;

			timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;

			if (ip->ip_dst.s_addr != igmp_all_hosts_group ||
			    igmp->igmp_group.s_addr != 0) {
				++igmpstat.igps_rcv_badqueries;
				m_freem(m);
				return;
			}
		} else {
			/*
			 * New router.  Simply do the new validity check.
			 */
			
			if (igmp->igmp_group.s_addr != 0 &&
			    !IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
				++igmpstat.igps_rcv_badqueries;
				m_freem(m);
				return;
			}
		}

		/*
		 * - Start the timers in all of our membership records
		 *   that the query applies to for the interface on
		 *   which the query arrived excl. those that belong
		 *   to the "all-hosts" group (224.0.0.1).
		 * - Restart any timer that is already running but has
		 *   a value longer than the requested timeout.
		 * - Use the value specified in the query message as
		 *   the maximum timeout.
		 */
		IN_FIRST_MULTI(step, inm);
		while (inm != NULL) {
			if (inm->inm_ifp == ifp &&
			    inm->inm_addr.s_addr != igmp_all_hosts_group &&
			    (igmp->igmp_group.s_addr == 0 ||
			     igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
				if (inm->inm_timer == 0 ||
				    inm->inm_timer > timer) {
					inm->inm_timer =
						IGMP_RANDOM_DELAY(timer);
					igmp_timers_are_running = 1;
				}
			}
			IN_NEXT_MULTI(step, inm);
		}

		break;

	case IGMP_V1_MEMBERSHIP_REPORT:
	case IGMP_V2_MEMBERSHIP_REPORT:
		/*
		 * For fast leave to work, we have to know that we are the
		 * last person to send a report for this group.  Reports
		 * can potentially get looped back if we are a multicast
		 * router, so discard reports sourced by me.
		 */
		IFP_TO_IA(ifp, ia);
		if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr)
			break;

		++igmpstat.igps_rcv_reports;

		if (ifp->if_flags & IFF_LOOPBACK)
			break;

		if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
			++igmpstat.igps_rcv_badreports;
			m_freem(m);
			return;
		}

		/*
		 * KLUDGE: if the IP source address of the report has an
		 * unspecified (i.e., zero) subnet number, as is allowed for
		 * a booting host, replace it with the correct subnet number
		 * so that a process-level multicast routing demon can
		 * determine which subnet it arrived from.  This is necessary
		 * to compensate for the lack of any way for a process to
		 * determine the arrival interface of an incoming packet.
		 */
		if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0)
			if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);

		/*
		 * If we belong to the group being reported, stop
		 * our timer for that group.
		 */
		IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);

		if (inm != NULL) {
			inm->inm_timer = 0;
			++igmpstat.igps_rcv_ourreports;

			inm->inm_state = IGMP_OTHERMEMBER;
		}

		break;
	}

	/*
	 * Pass all valid IGMP packets up to any process(es) listening
	 * on a raw IGMP socket.
	 */
	rip_input(m, iphlen);
}

void
igmp_joingroup(inm)
	struct in_multi *inm;
{
	int s = splnet();

	if (inm->inm_addr.s_addr == igmp_all_hosts_group
	    || inm->inm_ifp->if_flags & IFF_LOOPBACK) {
		inm->inm_timer = 0;
		inm->inm_state = IGMP_OTHERMEMBER;
	} else {
		inm->inm_rti = find_rti(inm->inm_ifp);
		igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
		inm->inm_timer = IGMP_RANDOM_DELAY(
					IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
		inm->inm_state = IGMP_IREPORTEDLAST;
		igmp_timers_are_running = 1;
	}
	splx(s);
}

void
igmp_leavegroup(inm)
	struct in_multi *inm;
{
	if (inm->inm_state == IGMP_IREPORTEDLAST &&
	    inm->inm_addr.s_addr != igmp_all_hosts_group &&
	    !(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
	    inm->inm_rti->rti_type != IGMP_V1_ROUTER)
		igmp_sendpkt(inm, IGMP_V2_LEAVE_GROUP, igmp_all_rtrs_group);
}

void
igmp_fasttimo()
{
	register struct in_multi *inm;
	struct in_multistep step;
	int s;

	/*
	 * Quick check to see if any work needs to be done, in order
	 * to minimize the overhead of fasttimo processing.
	 */

	if (!igmp_timers_are_running)
		return;

	s = splnet();
	igmp_timers_are_running = 0;
	IN_FIRST_MULTI(step, inm);
	while (inm != NULL) {
		if (inm->inm_timer == 0) {
			/* do nothing */
		} else if (--inm->inm_timer == 0) {
			igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
			inm->inm_state = IGMP_IREPORTEDLAST;
		} else {
			igmp_timers_are_running = 1;
		}
		IN_NEXT_MULTI(step, inm);
	}
	splx(s);
}

void
igmp_slowtimo()
{
	int s = splnet();
	register struct router_info *rti =  Head;

#if IGMP_DEBUG
	printf("[igmp.c,_slowtimo] -- > entering \n");
#endif
	while (rti) {
	    if (rti->rti_type == IGMP_V1_ROUTER) {
		rti->rti_time++;
		if (rti->rti_time >= IGMP_AGE_THRESHOLD) {
			rti->rti_type = IGMP_V2_ROUTER;
		}
	    }
	    rti = rti->rti_next;
	}
#if IGMP_DEBUG	
	printf("[igmp.c,_slowtimo] -- > exiting \n");
#endif
	splx(s);
}

static struct route igmprt;

static void
igmp_sendpkt(inm, type, addr)
	struct in_multi *inm;
	int type;
	unsigned long addr;
{
        struct mbuf *m;
        struct igmp *igmp;
        struct ip *ip;
        struct ip_moptions imo;

        MGETHDR(m, M_DONTWAIT, MT_HEADER);
        if (m == NULL)
                return;

	m->m_pkthdr.rcvif = loif;
	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
	MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip));
	m->m_data += sizeof(struct ip);
        m->m_len = IGMP_MINLEN;
	m->m_pkthdr.csum_flags = 0;
	m->m_pkthdr.csum_data = 0;
        igmp = mtod(m, struct igmp *);
        igmp->igmp_type   = type;
        igmp->igmp_code   = 0;
        igmp->igmp_group  = inm->inm_addr;
        igmp->igmp_cksum  = 0;
        igmp->igmp_cksum  = in_cksum(m, IGMP_MINLEN);

        m->m_data -= sizeof(struct ip);
        m->m_len += sizeof(struct ip);
        ip = mtod(m, struct ip *);
        ip->ip_tos        = 0;
        ip->ip_len        = sizeof(struct ip) + IGMP_MINLEN;
        ip->ip_off        = 0;
        ip->ip_p          = IPPROTO_IGMP;
        ip->ip_src.s_addr = INADDR_ANY;
        ip->ip_dst.s_addr = addr ? addr : igmp->igmp_group.s_addr;

        imo.imo_multicast_ifp  = inm->inm_ifp;
        imo.imo_multicast_ttl  = 1;
	imo.imo_multicast_vif  = -1;
        /*
         * Request loopback of the report if we are acting as a multicast
         * router, so that the process-level routing demon can hear it.
         */
        imo.imo_multicast_loop = (ip_mrouter != NULL);

	/*
	 * XXX
	 * Do we have to worry about reentrancy here?  Don't think so.
	 */
        ip_output(m, router_alert, &igmprt, 0, &imo);

        ++igmpstat.igps_snd_reports;
}
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
de355530 A	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
1c79356b	11	*
de355530 A	12	* This Original Code and all software distributed under the License are
de355530 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
de355530 A	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
1c79356b A	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* Copyright (c) 1988 Stephen Deering.
	24	* Copyright (c) 1992, 1993
	25	* The Regents of the University of California. All rights reserved.
	26	*
	27	* This code is derived from software contributed to Berkeley by
	28	* Stephen Deering of Stanford University.
	29	*
	30	* Redistribution and use in source and binary forms, with or without
	31	* modification, are permitted provided that the following conditions
	32	* are met:
	33	* 1. Redistributions of source code must retain the above copyright
	34	* notice, this list of conditions and the following disclaimer.
	35	* 2. Redistributions in binary form must reproduce the above copyright
	36	* notice, this list of conditions and the following disclaimer in the
	37	* documentation and/or other materials provided with the distribution.
	38	* 3. All advertising materials mentioning features or use of this software
	39	* must display the following acknowledgement:
	40	* This product includes software developed by the University of
	41	* California, Berkeley and its contributors.
	42	* 4. Neither the name of the University nor the names of its contributors
	43	* may be used to endorse or promote products derived from this software
	44	* without specific prior written permission.
	45	*
	46	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	47	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	48	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	49	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	50	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	51	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	52	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	53	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	54	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	55	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	56	* SUCH DAMAGE.
	57	*
	58	* @(#)igmp.c 8.1 (Berkeley) 7/19/93
	59	*/
	60
	61	/*
	62	* Internet Group Management Protocol (IGMP) routines.
	63	*
	64	* Written by Steve Deering, Stanford, May 1988.
	65	* Modified by Rosen Sharma, Stanford, Aug 1994.
	66	* Modified by Bill Fenner, Xerox PARC, Feb 1995.
	67	* Modified to fully comply to IGMPv2 by Bill Fenner, Oct 1995.
	68	*
	69	* MULTICAST Revision: 3.5.1.4
	70	*/
	71
	72	#include <sys/param.h>
	73	#include <sys/systm.h>
	74	#include <sys/malloc.h>
	75	#include <sys/mbuf.h>
	76	#include <sys/socket.h>
	77	#include <sys/protosw.h>
	78	#include <sys/kernel.h>
	79	#include <sys/sysctl.h>
	80
	81	#include <net/if.h>
	82	#include <net/route.h>
83
84	#include <netinet/in.h>
85	#include <netinet/in_var.h>
86	#include <netinet/in_systm.h>
87	#include <netinet/ip.h>
88	#include <netinet/ip_var.h>
89	#include <netinet/igmp.h>
90	#include <netinet/igmp_var.h>
91
9bccf70c	92	#ifndef __APPLE__
1c79356b	93	static MALLOC_DEFINE(M_IGMP, "igmp", "igmp state");
9bccf70c	94	#endif
1c79356b A	95
	96	static struct router_info *
	97	find_rti __P((struct ifnet *ifp));
	98
	99	static struct igmpstat igmpstat;
	100
	101	SYSCTL_STRUCT(_net_inet_igmp, IGMPCTL_STATS, stats, CTLFLAG_RD,
	102	&igmpstat, igmpstat, "");
	103
	104	static int igmp_timers_are_running;
	105	static u_long igmp_all_hosts_group;
	106	static u_long igmp_all_rtrs_group;
	107	static struct mbuf *router_alert;
	108	static struct router_info *Head;
	109
	110	static void igmp_sendpkt __P((struct in_multi *, int, unsigned long));
	111
	112	void
	113	igmp_init()
	114	{
	115	struct ipoption *ra;
	116
	117	/*
	118	* To avoid byte-swapping the same value over and over again.
	119	*/
	120	igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
	121	igmp_all_rtrs_group = htonl(INADDR_ALLRTRS_GROUP);
	122
	123	igmp_timers_are_running = 0;
	124
	125	/*
	126	* Construct a Router Alert option to use in outgoing packets
	127	*/
	128	MGET(router_alert, M_DONTWAIT, MT_DATA);
	129	ra = mtod(router_alert, struct ipoption *);
	130	ra->ipopt_dst.s_addr = 0;
	131	ra->ipopt_list[0] = IPOPT_RA; /* Router Alert Option */
	132	ra->ipopt_list[1] = 0x04; /* 4 bytes long */
	133	ra->ipopt_list[2] = 0x00;
	134	ra->ipopt_list[3] = 0x00;
	135	router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1];
	136
	137	Head = (struct router_info *) 0;
	138	}
	139
	140	static struct router_info *
	141	find_rti(ifp)
	142	struct ifnet *ifp;
	143	{
	144	register struct router_info *rti = Head;
	145
	146	#if IGMP_DEBUG
	147	printf("[igmp.c, _find_rti] --> entering \n");
	148	#endif
	149	while (rti) {
	150	if (rti->rti_ifp == ifp) {
	151	#if IGMP_DEBUG
	152	printf("[igmp.c, _find_rti] --> found old entry \n");
	153	#endif
	154	return rti;
	155	}
	156	rti = rti->rti_next;
	157	}
	158
1c79356b	159	MALLOC(rti, struct router_info , sizeof rti, M_IGMP, M_NOWAIT);
1c79356b A	160	rti->rti_ifp = ifp;
	161	rti->rti_type = IGMP_V2_ROUTER;
	162	rti->rti_time = 0;
	163	rti->rti_next = Head;
	164	Head = rti;
	165	#if IGMP_DEBUG
	166	printf("[igmp.c, _find_rti] --> created an entry \n");
	167	#endif
	168	return rti;
	169	}
	170
	171	void
	172	igmp_input(m, iphlen)
	173	register struct mbuf *m;
	174	register int iphlen;
	175	{
	176	register struct igmp *igmp;
	177	register struct ip *ip;
	178	register int igmplen;
	179	register struct ifnet *ifp = m->m_pkthdr.rcvif;
	180	register int minlen;
	181	register struct in_multi *inm;
	182	register struct in_ifaddr *ia;
	183	struct in_multistep step;
	184	struct router_info *rti;
	185
	186	int timer; / timer value in the igmp query header /
	187
	188	++igmpstat.igps_rcv_total;
	189
	190	ip = mtod(m, struct ip *);
	191	igmplen = ip->ip_len;
	192
	193	/*
	194	* Validate lengths
	195	*/
	196	if (igmplen < IGMP_MINLEN) {
	197	++igmpstat.igps_rcv_tooshort;
	198	m_freem(m);
	199	return;
	200	}
	201	minlen = iphlen + IGMP_MINLEN;
	202	if ((m->m_flags & M_EXT \|\| m->m_len < minlen) &&
	203	(m = m_pullup(m, minlen)) == 0) {
	204	++igmpstat.igps_rcv_tooshort;
	205	return;
	206	}
	207
	208	/*
	209	* Validate checksum
	210	*/
	211	m->m_data += iphlen;
	212	m->m_len -= iphlen;
	213	igmp = mtod(m, struct igmp *);
	214	if (in_cksum(m, igmplen)) {
	215	++igmpstat.igps_rcv_badsum;
	216	m_freem(m);
	217	return;
	218	}
	219	m->m_data -= iphlen;
	220	m->m_len += iphlen;
	221
	222	ip = mtod(m, struct ip *);
	223	timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
224	if (timer == 0)
225	timer = 1;
226	rti = find_rti(ifp);
227
228	/*
229	* In the IGMPv2 specification, there are 3 states and a flag.
230	*
231	* In Non-Member state, we simply don't have a membership record.
232	* In Delaying Member state, our timer is running (inm->inm_timer)
233	* In Idle Member state, our timer is not running (inm->inm_timer==0)
234	*
235	* The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
236	* we have heard a report from another member, or IGMP_IREPORTEDLAST
237	* if I sent the last report.
238	*/
239	switch (igmp->igmp_type) {
240
241	case IGMP_MEMBERSHIP_QUERY:
242	++igmpstat.igps_rcv_queries;
243
244	if (ifp->if_flags & IFF_LOOPBACK)
245	break;
246
247	if (igmp->igmp_code == 0) {
248	/*
249	* Old router. Remember that the querier on this
250	* interface is old, and set the timer to the
251	* value in RFC 1112.
252	*/
253
254	rti->rti_type = IGMP_V1_ROUTER;
255	rti->rti_time = 0;
256
257	timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;
258
259	if (ip->ip_dst.s_addr != igmp_all_hosts_group \|\|
260	igmp->igmp_group.s_addr != 0) {
261	++igmpstat.igps_rcv_badqueries;
262	m_freem(m);
263	return;
264	}
265	} else {
266	/*
267	* New router. Simply do the new validity check.
268	*/
269
270	if (igmp->igmp_group.s_addr != 0 &&
271	!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
272	++igmpstat.igps_rcv_badqueries;
273	m_freem(m);
274	return;
275	}
276	}
277
278	/*
279	* - Start the timers in all of our membership records
280	* that the query applies to for the interface on
281	* which the query arrived excl. those that belong
282	* to the "all-hosts" group (224.0.0.1).
283	* - Restart any timer that is already running but has
284	* a value longer than the requested timeout.
285	* - Use the value specified in the query message as
286	* the maximum timeout.
287	*/
288	IN_FIRST_MULTI(step, inm);
289	while (inm != NULL) {
290	if (inm->inm_ifp == ifp &&
291	inm->inm_addr.s_addr != igmp_all_hosts_group &&
292	(igmp->igmp_group.s_addr == 0 \|\|
293	igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
294	if (inm->inm_timer == 0 \|\|
295	inm->inm_timer > timer) {
296	inm->inm_timer =
297	IGMP_RANDOM_DELAY(timer);
298	igmp_timers_are_running = 1;
299	}
300	}
301	IN_NEXT_MULTI(step, inm);
302	}
303
304	break;
305
306	case IGMP_V1_MEMBERSHIP_REPORT:
307	case IGMP_V2_MEMBERSHIP_REPORT:
308	/*
309	* For fast leave to work, we have to know that we are the
310	* last person to send a report for this group. Reports
311	* can potentially get looped back if we are a multicast
312	* router, so discard reports sourced by me.
313	*/
314	IFP_TO_IA(ifp, ia);
315	if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr)
316	break;
317
318	++igmpstat.igps_rcv_reports;
319
320	if (ifp->if_flags & IFF_LOOPBACK)
321	break;
322
323	if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
324	++igmpstat.igps_rcv_badreports;
325	m_freem(m);
326	return;
327	}
328
329	/*
330	* KLUDGE: if the IP source address of the report has an
331	* unspecified (i.e., zero) subnet number, as is allowed for
332	* a booting host, replace it with the correct subnet number
333	* so that a process-level multicast routing demon can
334	* determine which subnet it arrived from. This is necessary
335	* to compensate for the lack of any way for a process to
336	* determine the arrival interface of an incoming packet.
337	*/
338	if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0)
339	if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
340
341	/*
342	* If we belong to the group being reported, stop
343	* our timer for that group.
344	*/
345	IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
346
347	if (inm != NULL) {
348	inm->inm_timer = 0;
349	++igmpstat.igps_rcv_ourreports;
350
351	inm->inm_state = IGMP_OTHERMEMBER;
352	}
353
354	break;
355	}
356
357	/*
358	* Pass all valid IGMP packets up to any process(es) listening
359	* on a raw IGMP socket.
360	*/
361	rip_input(m, iphlen);
362	}
363
364	void
365	igmp_joingroup(inm)
366	struct in_multi *inm;
367	{
368	int s = splnet();
369
370	if (inm->inm_addr.s_addr == igmp_all_hosts_group
371	\|\| inm->inm_ifp->if_flags & IFF_LOOPBACK) {
372	inm->inm_timer = 0;
373	inm->inm_state = IGMP_OTHERMEMBER;
374	} else {
375	inm->inm_rti = find_rti(inm->inm_ifp);
376	igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
377	inm->inm_timer = IGMP_RANDOM_DELAY(
378	IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
379	inm->inm_state = IGMP_IREPORTEDLAST;
380	igmp_timers_are_running = 1;
381	}
382	splx(s);
383	}
384
385	void
386	igmp_leavegroup(inm)
387	struct in_multi *inm;
388	{
389	if (inm->inm_state == IGMP_IREPORTEDLAST &&
390	inm->inm_addr.s_addr != igmp_all_hosts_group &&
391	!(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
392	inm->inm_rti->rti_type != IGMP_V1_ROUTER)
393	igmp_sendpkt(inm, IGMP_V2_LEAVE_GROUP, igmp_all_rtrs_group);
394	}
395
396	void
397	igmp_fasttimo()
398	{
399	register struct in_multi *inm;
400	struct in_multistep step;
401	int s;
402
403	/*
404	* Quick check to see if any work needs to be done, in order
405	* to minimize the overhead of fasttimo processing.
406	*/
407
408	if (!igmp_timers_are_running)
409	return;
410
411	s = splnet();
412	igmp_timers_are_running = 0;
413	IN_FIRST_MULTI(step, inm);
414	while (inm != NULL) {
415	if (inm->inm_timer == 0) {
416	/* do nothing */
417	} else if (--inm->inm_timer == 0) {
418	igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
419	inm->inm_state = IGMP_IREPORTEDLAST;
420	} else {
421	igmp_timers_are_running = 1;
422	}
423	IN_NEXT_MULTI(step, inm);
424	}
425	splx(s);
426	}
427
428	void
429	igmp_slowtimo()
430	{
431	int s = splnet();
432	register struct router_info *rti = Head;
433
434	#if IGMP_DEBUG
435	printf("[igmp.c,_slowtimo] -- > entering \n");
436	#endif
437	while (rti) {
438	if (rti->rti_type == IGMP_V1_ROUTER) {
439	rti->rti_time++;
440	if (rti->rti_time >= IGMP_AGE_THRESHOLD) {
441	rti->rti_type = IGMP_V2_ROUTER;
442	}
443	}
444	rti = rti->rti_next;
445	}
446	#if IGMP_DEBUG
447	printf("[igmp.c,_slowtimo] -- > exiting \n");
448	#endif
449	splx(s);
450	}
451
452	static struct route igmprt;
453
454	static void
455	igmp_sendpkt(inm, type, addr)
456	struct in_multi *inm;
457	int type;
458	unsigned long addr;
459	{
460	struct mbuf *m;
461	struct igmp *igmp;
462	struct ip *ip;
463	struct ip_moptions imo;
464
465	MGETHDR(m, M_DONTWAIT, MT_HEADER);
466	if (m == NULL)
467	return;
468
469	m->m_pkthdr.rcvif = loif;
470	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
471	MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip));
472	m->m_data += sizeof(struct ip);
473	m->m_len = IGMP_MINLEN;
0b4e3aa0 A	474	m->m_pkthdr.csum_flags = 0;
0b4e3aa0 A	475	m->m_pkthdr.csum_data = 0;
1c79356b A	476	igmp = mtod(m, struct igmp *);
	477	igmp->igmp_type = type;
	478	igmp->igmp_code = 0;
	479	igmp->igmp_group = inm->inm_addr;
	480	igmp->igmp_cksum = 0;
	481	igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
	482
	483	m->m_data -= sizeof(struct ip);
	484	m->m_len += sizeof(struct ip);
	485	ip = mtod(m, struct ip *);
	486	ip->ip_tos = 0;
	487	ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
	488	ip->ip_off = 0;
	489	ip->ip_p = IPPROTO_IGMP;
	490	ip->ip_src.s_addr = INADDR_ANY;
	491	ip->ip_dst.s_addr = addr ? addr : igmp->igmp_group.s_addr;
	492
	493	imo.imo_multicast_ifp = inm->inm_ifp;
	494	imo.imo_multicast_ttl = 1;
	495	imo.imo_multicast_vif = -1;
	496	/*
	497	* Request loopback of the report if we are acting as a multicast
	498	* router, so that the process-level routing demon can hear it.
	499	*/
	500	imo.imo_multicast_loop = (ip_mrouter != NULL);
	501
	502	/*
	503	* XXX
	504	* Do we have to worry about reentrancy here? Don't think so.
	505	*/
1c79356b A	506	ip_output(m, router_alert, &igmprt, 0, &imo);
	507
	508	++igmpstat.igps_snd_reports;
	509	}