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

/*
 * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
 * 
 * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code 
 * as defined in and that are subject to the Apple Public Source License 
 * Version 2.0 (the 'License'). You may not use this file except in 
 * compliance with the License.  The rights granted to you under the 
 * License may not be used to create, or enable the creation or 
 * redistribution of, unlawful or unlicensed copies of an Apple operating 
 * system, or to circumvent, violate, or enable the circumvention or 
 * violation of, any terms of an Apple operating system software license 
 * agreement.
 *
 * Please obtain a copy of the License at 
 * http://www.opensource.apple.com/apsl/ and read it before using this 
 * file.
 *
 * The 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, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
 * Please see the License for the specific language governing rights and 
 * limitations under the License.
 *
 * @APPLE_LICENSE_OSREFERENCE_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(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(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(
	struct ifnet *ifp)
{
	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);
	if (rti != NULL)
	{
		rti->rti_ifp = ifp;
		rti->rti_type = IGMP_V2_ROUTER;
		rti->rti_time = 0;
		rti->rti_next = Head;
		Head = rti;
	}
#if IGMP_DEBUG
	if (rti) printf("[igmp.c, _find_rti] --> created an entry \n");
#endif
	return rti;
}

void
igmp_input(
	struct mbuf *m,
	int iphlen)
{
	struct igmp *igmp;
	struct ip *ip;
	int igmplen;
	struct ifnet *ifp = m->m_pkthdr.rcvif;
	int minlen;
	struct in_multi *inm;
	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);
	if (rti == NULL) {
		m_freem(m);
		return;
	}

	/*
	 * 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.
		 */
		lck_mtx_lock(rt_mtx);
		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);
		}
		lck_mtx_unlock(rt_mtx);

		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.
		 */
		ifnet_lock_shared(ifp);
		IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
		ifnet_lock_done(ifp);

		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);
}

int
igmp_joingroup(inm)
	struct in_multi *inm;
{

	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);
		if (inm->inm_rti == NULL) return ENOMEM;
		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;
	}
	return 0;
}

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()
{
	struct in_multi *inm;
	struct in_multistep step;

	/*
	 * 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;

	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);
	}
}

void
igmp_slowtimo()
{
	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
}

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	1	/*
8ad349bb	2	* Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
1c79356b	3	*
8ad349bb	4	* @APPLE_LICENSE_OSREFERENCE_HEADER_START@
1c79356b	5	*
8ad349bb A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the
	10	* License may not be used to create, or enable the creation or
	11	* redistribution of, unlawful or unlicensed copies of an Apple operating
	12	* system, or to circumvent, violate, or enable the circumvention or
	13	* violation of, any terms of an Apple operating system software license
	14	* agreement.
	15	*
	16	* Please obtain a copy of the License at
	17	* http://www.opensource.apple.com/apsl/ and read it before using this
	18	* file.
	19	*
	20	* The Original Code and all software distributed under the License are
	21	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	22	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	23	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	24	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	25	* Please see the License for the specific language governing rights and
	26	* limitations under the License.
	27	*
	28	* @APPLE_LICENSE_OSREFERENCE_HEADER_END@
1c79356b A	29	*/
	30	/*
	31	* Copyright (c) 1988 Stephen Deering.
	32	* Copyright (c) 1992, 1993
	33	* The Regents of the University of California. All rights reserved.
	34	*
	35	* This code is derived from software contributed to Berkeley by
	36	* Stephen Deering of Stanford University.
	37	*
	38	* Redistribution and use in source and binary forms, with or without
	39	* modification, are permitted provided that the following conditions
	40	* are met:
	41	* 1. Redistributions of source code must retain the above copyright
	42	* notice, this list of conditions and the following disclaimer.
	43	* 2. Redistributions in binary form must reproduce the above copyright
	44	* notice, this list of conditions and the following disclaimer in the
	45	* documentation and/or other materials provided with the distribution.
	46	* 3. All advertising materials mentioning features or use of this software
	47	* must display the following acknowledgement:
	48	* This product includes software developed by the University of
	49	* California, Berkeley and its contributors.
	50	* 4. Neither the name of the University nor the names of its contributors
	51	* may be used to endorse or promote products derived from this software
	52	* without specific prior written permission.
	53	*
	54	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	55	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	56	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	57	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	58	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	59	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	60	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	61	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	62	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	63	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	64	* SUCH DAMAGE.
	65	*
	66	* @(#)igmp.c 8.1 (Berkeley) 7/19/93
	67	*/
	68
	69	/*
	70	* Internet Group Management Protocol (IGMP) routines.
	71	*
	72	* Written by Steve Deering, Stanford, May 1988.
	73	* Modified by Rosen Sharma, Stanford, Aug 1994.
	74	* Modified by Bill Fenner, Xerox PARC, Feb 1995.
	75	* Modified to fully comply to IGMPv2 by Bill Fenner, Oct 1995.
	76	*
	77	* MULTICAST Revision: 3.5.1.4
	78	*/
	79
	80	#include <sys/param.h>
	81	#include <sys/systm.h>
	82	#include <sys/malloc.h>
	83	#include <sys/mbuf.h>
	84	#include <sys/socket.h>
	85	#include <sys/protosw.h>
	86	#include <sys/kernel.h>
	87	#include <sys/sysctl.h>
	88
	89	#include <net/if.h>
	90	#include <net/route.h>
	91
	92	#include <netinet/in.h>
93	#include <netinet/in_var.h>
94	#include <netinet/in_systm.h>
95	#include <netinet/ip.h>
96	#include <netinet/ip_var.h>
97	#include <netinet/igmp.h>
98	#include <netinet/igmp_var.h>
99
9bccf70c	100	#ifndef __APPLE__
1c79356b	101	static MALLOC_DEFINE(M_IGMP, "igmp", "igmp state");
9bccf70c	102	#endif
1c79356b A	103
1c79356b A	104	static struct router_info *
91447636	105	find_rti(struct ifnet *ifp);
1c79356b A	106
	107	static struct igmpstat igmpstat;
	108
	109	SYSCTL_STRUCT(_net_inet_igmp, IGMPCTL_STATS, stats, CTLFLAG_RD,
	110	&igmpstat, igmpstat, "");
	111
	112	static int igmp_timers_are_running;
	113	static u_long igmp_all_hosts_group;
	114	static u_long igmp_all_rtrs_group;
	115	static struct mbuf *router_alert;
	116	static struct router_info *Head;
	117
91447636	118	static void igmp_sendpkt(struct in_multi *, int, unsigned long);
1c79356b A	119
	120	void
	121	igmp_init()
	122	{
	123	struct ipoption *ra;
	124
	125	/*
	126	* To avoid byte-swapping the same value over and over again.
	127	*/
	128	igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
	129	igmp_all_rtrs_group = htonl(INADDR_ALLRTRS_GROUP);
	130
	131	igmp_timers_are_running = 0;
	132
	133	/*
	134	* Construct a Router Alert option to use in outgoing packets
	135	*/
	136	MGET(router_alert, M_DONTWAIT, MT_DATA);
	137	ra = mtod(router_alert, struct ipoption *);
	138	ra->ipopt_dst.s_addr = 0;
	139	ra->ipopt_list[0] = IPOPT_RA; /* Router Alert Option */
	140	ra->ipopt_list[1] = 0x04; /* 4 bytes long */
	141	ra->ipopt_list[2] = 0x00;
	142	ra->ipopt_list[3] = 0x00;
	143	router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1];
	144
	145	Head = (struct router_info *) 0;
	146	}
	147
	148	static struct router_info *
91447636 A	149	find_rti(
91447636 A	150	struct ifnet *ifp)
1c79356b	151	{
91447636	152	struct router_info *rti = Head;
55e303ae A	153
55e303ae A	154
1c79356b A	155	#if IGMP_DEBUG
	156	printf("[igmp.c, _find_rti] --> entering \n");
	157	#endif
55e303ae A	158	while (rti) {
55e303ae A	159	if (rti->rti_ifp == ifp) {
1c79356b A	160	#if IGMP_DEBUG
	161	printf("[igmp.c, _find_rti] --> found old entry \n");
	162	#endif
55e303ae A	163	return rti;
	164	}
	165	rti = rti->rti_next;
	166	}
	167
1c79356b	168	MALLOC(rti, struct router_info , sizeof rti, M_IGMP, M_NOWAIT);
55e303ae A	169	if (rti != NULL)
	170	{
	171	rti->rti_ifp = ifp;
	172	rti->rti_type = IGMP_V2_ROUTER;
	173	rti->rti_time = 0;
	174	rti->rti_next = Head;
	175	Head = rti;
	176	}
1c79356b	177	#if IGMP_DEBUG
55e303ae	178	if (rti) printf("[igmp.c, _find_rti] --> created an entry \n");
1c79356b	179	#endif
55e303ae	180	return rti;
1c79356b A	181	}
	182
	183	void
91447636 A	184	igmp_input(
	185	struct mbuf *m,
	186	int iphlen)
1c79356b	187	{
91447636 A	188	struct igmp *igmp;
	189	struct ip *ip;
	190	int igmplen;
	191	struct ifnet *ifp = m->m_pkthdr.rcvif;
	192	int minlen;
	193	struct in_multi *inm;
	194	struct in_ifaddr *ia;
1c79356b A	195	struct in_multistep step;
	196	struct router_info *rti;
	197
	198	int timer; / timer value in the igmp query header /
	199
	200	++igmpstat.igps_rcv_total;
	201
	202	ip = mtod(m, struct ip *);
	203	igmplen = ip->ip_len;
	204
	205	/*
	206	* Validate lengths
	207	*/
	208	if (igmplen < IGMP_MINLEN) {
	209	++igmpstat.igps_rcv_tooshort;
	210	m_freem(m);
	211	return;
	212	}
	213	minlen = iphlen + IGMP_MINLEN;
	214	if ((m->m_flags & M_EXT \|\| m->m_len < minlen) &&
	215	(m = m_pullup(m, minlen)) == 0) {
	216	++igmpstat.igps_rcv_tooshort;
	217	return;
	218	}
	219
	220	/*
	221	* Validate checksum
	222	*/
	223	m->m_data += iphlen;
	224	m->m_len -= iphlen;
	225	igmp = mtod(m, struct igmp *);
	226	if (in_cksum(m, igmplen)) {
	227	++igmpstat.igps_rcv_badsum;
	228	m_freem(m);
	229	return;
	230	}
	231	m->m_data -= iphlen;
	232	m->m_len += iphlen;
	233
	234	ip = mtod(m, struct ip *);
	235	timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
	236	if (timer == 0)
	237	timer = 1;
	238	rti = find_rti(ifp);
55e303ae A	239	if (rti == NULL) {
	240	m_freem(m);
	241	return;
	242	}
1c79356b A	243
	244	/*
	245	* In the IGMPv2 specification, there are 3 states and a flag.
	246	*
	247	* In Non-Member state, we simply don't have a membership record.
	248	* In Delaying Member state, our timer is running (inm->inm_timer)
	249	* In Idle Member state, our timer is not running (inm->inm_timer==0)
	250	*
	251	* The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
	252	* we have heard a report from another member, or IGMP_IREPORTEDLAST
	253	* if I sent the last report.
	254	*/
	255	switch (igmp->igmp_type) {
	256
	257	case IGMP_MEMBERSHIP_QUERY:
	258	++igmpstat.igps_rcv_queries;
	259
	260	if (ifp->if_flags & IFF_LOOPBACK)
	261	break;
	262
	263	if (igmp->igmp_code == 0) {
	264	/*
	265	* Old router. Remember that the querier on this
	266	* interface is old, and set the timer to the
	267	* value in RFC 1112.
	268	*/
	269
	270	rti->rti_type = IGMP_V1_ROUTER;
	271	rti->rti_time = 0;
	272
	273	timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;
	274
	275	if (ip->ip_dst.s_addr != igmp_all_hosts_group \|\|
	276	igmp->igmp_group.s_addr != 0) {
	277	++igmpstat.igps_rcv_badqueries;
	278	m_freem(m);
	279	return;
	280	}
	281	} else {
	282	/*
	283	* New router. Simply do the new validity check.
	284	*/
	285
	286	if (igmp->igmp_group.s_addr != 0 &&
	287	!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
	288	++igmpstat.igps_rcv_badqueries;
	289	m_freem(m);
	290	return;
	291	}
	292	}
	293
	294	/*
	295	* - Start the timers in all of our membership records
	296	* that the query applies to for the interface on
	297	* which the query arrived excl. those that belong
	298	* to the "all-hosts" group (224.0.0.1).
	299	* - Restart any timer that is already running but has
	300	* a value longer than the requested timeout.
	301	* - Use the value specified in the query message as
	302	* the maximum timeout.
	303	*/
91447636	304	lck_mtx_lock(rt_mtx);
1c79356b A	305	IN_FIRST_MULTI(step, inm);
	306	while (inm != NULL) {
	307	if (inm->inm_ifp == ifp &&
	308	inm->inm_addr.s_addr != igmp_all_hosts_group &&
	309	(igmp->igmp_group.s_addr == 0 \|\|
	310	igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
	311	if (inm->inm_timer == 0 \|\|
	312	inm->inm_timer > timer) {
	313	inm->inm_timer =
	314	IGMP_RANDOM_DELAY(timer);
	315	igmp_timers_are_running = 1;
	316	}
	317	}
	318	IN_NEXT_MULTI(step, inm);
	319	}
91447636	320	lck_mtx_unlock(rt_mtx);
1c79356b A	321
	322	break;
	323
	324	case IGMP_V1_MEMBERSHIP_REPORT:
	325	case IGMP_V2_MEMBERSHIP_REPORT:
	326	/*
	327	* For fast leave to work, we have to know that we are the
	328	* last person to send a report for this group. Reports
	329	* can potentially get looped back if we are a multicast
	330	* router, so discard reports sourced by me.
	331	*/
	332	IFP_TO_IA(ifp, ia);
	333	if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr)
	334	break;
	335
	336	++igmpstat.igps_rcv_reports;
	337
	338	if (ifp->if_flags & IFF_LOOPBACK)
	339	break;
	340
	341	if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
	342	++igmpstat.igps_rcv_badreports;
	343	m_freem(m);
	344	return;
	345	}
	346
	347	/*
	348	* KLUDGE: if the IP source address of the report has an
	349	* unspecified (i.e., zero) subnet number, as is allowed for
	350	* a booting host, replace it with the correct subnet number
	351	* so that a process-level multicast routing demon can
	352	* determine which subnet it arrived from. This is necessary
	353	* to compensate for the lack of any way for a process to
	354	* determine the arrival interface of an incoming packet.
	355	*/
	356	if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0)
	357	if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
	358
	359	/*
	360	* If we belong to the group being reported, stop
	361	* our timer for that group.
	362	*/
91447636	363	ifnet_lock_shared(ifp);
1c79356b	364	IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
91447636	365	ifnet_lock_done(ifp);
1c79356b A	366
	367	if (inm != NULL) {
	368	inm->inm_timer = 0;
	369	++igmpstat.igps_rcv_ourreports;
	370
	371	inm->inm_state = IGMP_OTHERMEMBER;
	372	}
	373
	374	break;
	375	}
	376
	377	/*
	378	* Pass all valid IGMP packets up to any process(es) listening
	379	* on a raw IGMP socket.
	380	*/
	381	rip_input(m, iphlen);
	382	}
	383
55e303ae	384	int
1c79356b A	385	igmp_joingroup(inm)
	386	struct in_multi *inm;
	387	{
1c79356b A	388
	389	if (inm->inm_addr.s_addr == igmp_all_hosts_group
	390	\|\| inm->inm_ifp->if_flags & IFF_LOOPBACK) {
	391	inm->inm_timer = 0;
	392	inm->inm_state = IGMP_OTHERMEMBER;
	393	} else {
	394	inm->inm_rti = find_rti(inm->inm_ifp);
55e303ae	395	if (inm->inm_rti == NULL) return ENOMEM;
1c79356b A	396	igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
	397	inm->inm_timer = IGMP_RANDOM_DELAY(
	398	IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
	399	inm->inm_state = IGMP_IREPORTEDLAST;
	400	igmp_timers_are_running = 1;
	401	}
55e303ae	402	return 0;
1c79356b A	403	}
	404
	405	void
	406	igmp_leavegroup(inm)
	407	struct in_multi *inm;
	408	{
	409	if (inm->inm_state == IGMP_IREPORTEDLAST &&
	410	inm->inm_addr.s_addr != igmp_all_hosts_group &&
	411	!(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
	412	inm->inm_rti->rti_type != IGMP_V1_ROUTER)
	413	igmp_sendpkt(inm, IGMP_V2_LEAVE_GROUP, igmp_all_rtrs_group);
	414	}
	415
	416	void
	417	igmp_fasttimo()
	418	{
91447636	419	struct in_multi *inm;
1c79356b	420	struct in_multistep step;
1c79356b A	421
	422	/*
	423	* Quick check to see if any work needs to be done, in order
	424	* to minimize the overhead of fasttimo processing.
	425	*/
	426
	427	if (!igmp_timers_are_running)
	428	return;
	429
1c79356b A	430	igmp_timers_are_running = 0;
	431	IN_FIRST_MULTI(step, inm);
	432	while (inm != NULL) {
	433	if (inm->inm_timer == 0) {
	434	/* do nothing */
	435	} else if (--inm->inm_timer == 0) {
	436	igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
	437	inm->inm_state = IGMP_IREPORTEDLAST;
	438	} else {
	439	igmp_timers_are_running = 1;
	440	}
	441	IN_NEXT_MULTI(step, inm);
	442	}
1c79356b A	443	}
	444
	445	void
	446	igmp_slowtimo()
	447	{
91447636	448	struct router_info *rti = Head;
1c79356b A	449
	450	#if IGMP_DEBUG
	451	printf("[igmp.c,_slowtimo] -- > entering \n");
	452	#endif
	453	while (rti) {
	454	if (rti->rti_type == IGMP_V1_ROUTER) {
	455	rti->rti_time++;
	456	if (rti->rti_time >= IGMP_AGE_THRESHOLD) {
	457	rti->rti_type = IGMP_V2_ROUTER;
	458	}
	459	}
	460	rti = rti->rti_next;
	461	}
	462	#if IGMP_DEBUG
	463	printf("[igmp.c,_slowtimo] -- > exiting \n");
	464	#endif
1c79356b A	465	}
	466
	467	static struct route igmprt;
	468
	469	static void
	470	igmp_sendpkt(inm, type, addr)
	471	struct in_multi *inm;
	472	int type;
	473	unsigned long addr;
	474	{
	475	struct mbuf *m;
	476	struct igmp *igmp;
	477	struct ip *ip;
	478	struct ip_moptions imo;
	479
	480	MGETHDR(m, M_DONTWAIT, MT_HEADER);
	481	if (m == NULL)
	482	return;
	483
	484	m->m_pkthdr.rcvif = loif;
	485	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
	486	MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip));
	487	m->m_data += sizeof(struct ip);
	488	m->m_len = IGMP_MINLEN;
0b4e3aa0 A	489	m->m_pkthdr.csum_flags = 0;
0b4e3aa0 A	490	m->m_pkthdr.csum_data = 0;
1c79356b A	491	igmp = mtod(m, struct igmp *);
	492	igmp->igmp_type = type;
	493	igmp->igmp_code = 0;
	494	igmp->igmp_group = inm->inm_addr;
	495	igmp->igmp_cksum = 0;
	496	igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
	497
	498	m->m_data -= sizeof(struct ip);
	499	m->m_len += sizeof(struct ip);
	500	ip = mtod(m, struct ip *);
	501	ip->ip_tos = 0;
	502	ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
	503	ip->ip_off = 0;
	504	ip->ip_p = IPPROTO_IGMP;
	505	ip->ip_src.s_addr = INADDR_ANY;
	506	ip->ip_dst.s_addr = addr ? addr : igmp->igmp_group.s_addr;
	507
	508	imo.imo_multicast_ifp = inm->inm_ifp;
	509	imo.imo_multicast_ttl = 1;
	510	imo.imo_multicast_vif = -1;
	511	/*
	512	* Request loopback of the report if we are acting as a multicast
	513	* router, so that the process-level routing demon can hear it.
	514	*/
	515	imo.imo_multicast_loop = (ip_mrouter != NULL);
	516
	517	/*
	518	* XXX
	519	* Do we have to worry about reentrancy here? Don't think so.
	520	*/
1c79356b A	521	ip_output(m, router_alert, &igmprt, 0, &imo);
	522
	523	++igmpstat.igps_snd_reports;
	524	}