[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(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 A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
e5568f75 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	*
e5568f75 A	12	* This Original Code and all software distributed under the License are
e5568f75 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,
e5568f75 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
1c79356b A	96	static struct router_info *
91447636	97	find_rti(struct ifnet *ifp);
1c79356b A	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
91447636	110	static void igmp_sendpkt(struct in_multi *, int, unsigned long);
1c79356b A	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 *
91447636 A	141	find_rti(
91447636 A	142	struct ifnet *ifp)
1c79356b	143	{
91447636	144	struct router_info *rti = Head;
55e303ae A	145
55e303ae A	146
1c79356b A	147	#if IGMP_DEBUG
	148	printf("[igmp.c, _find_rti] --> entering \n");
	149	#endif
55e303ae A	150	while (rti) {
55e303ae A	151	if (rti->rti_ifp == ifp) {
1c79356b A	152	#if IGMP_DEBUG
	153	printf("[igmp.c, _find_rti] --> found old entry \n");
	154	#endif
55e303ae A	155	return rti;
	156	}
	157	rti = rti->rti_next;
	158	}
	159
1c79356b	160	MALLOC(rti, struct router_info , sizeof rti, M_IGMP, M_NOWAIT);
55e303ae A	161	if (rti != NULL)
	162	{
	163	rti->rti_ifp = ifp;
	164	rti->rti_type = IGMP_V2_ROUTER;
	165	rti->rti_time = 0;
	166	rti->rti_next = Head;
	167	Head = rti;
	168	}
1c79356b	169	#if IGMP_DEBUG
55e303ae	170	if (rti) printf("[igmp.c, _find_rti] --> created an entry \n");
1c79356b	171	#endif
55e303ae	172	return rti;
1c79356b A	173	}
	174
	175	void
91447636 A	176	igmp_input(
	177	struct mbuf *m,
	178	int iphlen)
1c79356b	179	{
91447636 A	180	struct igmp *igmp;
	181	struct ip *ip;
	182	int igmplen;
	183	struct ifnet *ifp = m->m_pkthdr.rcvif;
	184	int minlen;
	185	struct in_multi *inm;
	186	struct in_ifaddr *ia;
1c79356b A	187	struct in_multistep step;
	188	struct router_info *rti;
	189
	190	int timer; / timer value in the igmp query header /
	191
	192	++igmpstat.igps_rcv_total;
	193
	194	ip = mtod(m, struct ip *);
	195	igmplen = ip->ip_len;
	196
	197	/*
	198	* Validate lengths
	199	*/
	200	if (igmplen < IGMP_MINLEN) {
	201	++igmpstat.igps_rcv_tooshort;
	202	m_freem(m);
	203	return;
	204	}
	205	minlen = iphlen + IGMP_MINLEN;
	206	if ((m->m_flags & M_EXT \|\| m->m_len < minlen) &&
	207	(m = m_pullup(m, minlen)) == 0) {
	208	++igmpstat.igps_rcv_tooshort;
	209	return;
	210	}
	211
	212	/*
	213	* Validate checksum
	214	*/
	215	m->m_data += iphlen;
	216	m->m_len -= iphlen;
	217	igmp = mtod(m, struct igmp *);
	218	if (in_cksum(m, igmplen)) {
	219	++igmpstat.igps_rcv_badsum;
	220	m_freem(m);
	221	return;
	222	}
	223	m->m_data -= iphlen;
	224	m->m_len += iphlen;
	225
	226	ip = mtod(m, struct ip *);
	227	timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
	228	if (timer == 0)
	229	timer = 1;
	230	rti = find_rti(ifp);
55e303ae A	231	if (rti == NULL) {
	232	m_freem(m);
	233	return;
	234	}
1c79356b A	235
	236	/*
	237	* In the IGMPv2 specification, there are 3 states and a flag.
	238	*
	239	* In Non-Member state, we simply don't have a membership record.
	240	* In Delaying Member state, our timer is running (inm->inm_timer)
	241	* In Idle Member state, our timer is not running (inm->inm_timer==0)
	242	*
	243	* The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
	244	* we have heard a report from another member, or IGMP_IREPORTEDLAST
	245	* if I sent the last report.
	246	*/
	247	switch (igmp->igmp_type) {
	248
	249	case IGMP_MEMBERSHIP_QUERY:
	250	++igmpstat.igps_rcv_queries;
	251
	252	if (ifp->if_flags & IFF_LOOPBACK)
	253	break;
	254
	255	if (igmp->igmp_code == 0) {
	256	/*
	257	* Old router. Remember that the querier on this
	258	* interface is old, and set the timer to the
	259	* value in RFC 1112.
	260	*/
	261
	262	rti->rti_type = IGMP_V1_ROUTER;
	263	rti->rti_time = 0;
	264
	265	timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;
	266
	267	if (ip->ip_dst.s_addr != igmp_all_hosts_group \|\|
	268	igmp->igmp_group.s_addr != 0) {
	269	++igmpstat.igps_rcv_badqueries;
	270	m_freem(m);
	271	return;
	272	}
	273	} else {
	274	/*
	275	* New router. Simply do the new validity check.
	276	*/
	277
	278	if (igmp->igmp_group.s_addr != 0 &&
	279	!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
	280	++igmpstat.igps_rcv_badqueries;
	281	m_freem(m);
	282	return;
	283	}
	284	}
	285
	286	/*
	287	* - Start the timers in all of our membership records
	288	* that the query applies to for the interface on
	289	* which the query arrived excl. those that belong
	290	* to the "all-hosts" group (224.0.0.1).
	291	* - Restart any timer that is already running but has
	292	* a value longer than the requested timeout.
	293	* - Use the value specified in the query message as
	294	* the maximum timeout.
	295	*/
91447636	296	lck_mtx_lock(rt_mtx);
1c79356b A	297	IN_FIRST_MULTI(step, inm);
	298	while (inm != NULL) {
	299	if (inm->inm_ifp == ifp &&
	300	inm->inm_addr.s_addr != igmp_all_hosts_group &&
	301	(igmp->igmp_group.s_addr == 0 \|\|
	302	igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
	303	if (inm->inm_timer == 0 \|\|
	304	inm->inm_timer > timer) {
	305	inm->inm_timer =
	306	IGMP_RANDOM_DELAY(timer);
	307	igmp_timers_are_running = 1;
	308	}
	309	}
	310	IN_NEXT_MULTI(step, inm);
	311	}
91447636	312	lck_mtx_unlock(rt_mtx);
1c79356b A	313
	314	break;
	315
	316	case IGMP_V1_MEMBERSHIP_REPORT:
	317	case IGMP_V2_MEMBERSHIP_REPORT:
	318	/*
	319	* For fast leave to work, we have to know that we are the
	320	* last person to send a report for this group. Reports
	321	* can potentially get looped back if we are a multicast
	322	* router, so discard reports sourced by me.
	323	*/
	324	IFP_TO_IA(ifp, ia);
	325	if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr)
	326	break;
	327
	328	++igmpstat.igps_rcv_reports;
	329
	330	if (ifp->if_flags & IFF_LOOPBACK)
	331	break;
	332
	333	if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
	334	++igmpstat.igps_rcv_badreports;
	335	m_freem(m);
	336	return;
	337	}
	338
	339	/*
	340	* KLUDGE: if the IP source address of the report has an
	341	* unspecified (i.e., zero) subnet number, as is allowed for
	342	* a booting host, replace it with the correct subnet number
	343	* so that a process-level multicast routing demon can
	344	* determine which subnet it arrived from. This is necessary
	345	* to compensate for the lack of any way for a process to
	346	* determine the arrival interface of an incoming packet.
	347	*/
	348	if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0)
	349	if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
	350
	351	/*
	352	* If we belong to the group being reported, stop
	353	* our timer for that group.
	354	*/
91447636	355	ifnet_lock_shared(ifp);
1c79356b	356	IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
91447636	357	ifnet_lock_done(ifp);
1c79356b A	358
	359	if (inm != NULL) {
	360	inm->inm_timer = 0;
	361	++igmpstat.igps_rcv_ourreports;
	362
	363	inm->inm_state = IGMP_OTHERMEMBER;
	364	}
	365
	366	break;
	367	}
	368
	369	/*
	370	* Pass all valid IGMP packets up to any process(es) listening
	371	* on a raw IGMP socket.
	372	*/
	373	rip_input(m, iphlen);
	374	}
	375
55e303ae	376	int
1c79356b A	377	igmp_joingroup(inm)
	378	struct in_multi *inm;
	379	{
1c79356b A	380
	381	if (inm->inm_addr.s_addr == igmp_all_hosts_group
	382	\|\| inm->inm_ifp->if_flags & IFF_LOOPBACK) {
	383	inm->inm_timer = 0;
	384	inm->inm_state = IGMP_OTHERMEMBER;
	385	} else {
	386	inm->inm_rti = find_rti(inm->inm_ifp);
55e303ae	387	if (inm->inm_rti == NULL) return ENOMEM;
1c79356b A	388	igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
	389	inm->inm_timer = IGMP_RANDOM_DELAY(
	390	IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
	391	inm->inm_state = IGMP_IREPORTEDLAST;
	392	igmp_timers_are_running = 1;
	393	}
55e303ae	394	return 0;
1c79356b A	395	}
	396
	397	void
	398	igmp_leavegroup(inm)
	399	struct in_multi *inm;
	400	{
	401	if (inm->inm_state == IGMP_IREPORTEDLAST &&
	402	inm->inm_addr.s_addr != igmp_all_hosts_group &&
	403	!(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
	404	inm->inm_rti->rti_type != IGMP_V1_ROUTER)
	405	igmp_sendpkt(inm, IGMP_V2_LEAVE_GROUP, igmp_all_rtrs_group);
	406	}
	407
	408	void
	409	igmp_fasttimo()
	410	{
91447636	411	struct in_multi *inm;
1c79356b	412	struct in_multistep step;
1c79356b A	413
	414	/*
	415	* Quick check to see if any work needs to be done, in order
	416	* to minimize the overhead of fasttimo processing.
	417	*/
	418
	419	if (!igmp_timers_are_running)
	420	return;
	421
1c79356b A	422	igmp_timers_are_running = 0;
	423	IN_FIRST_MULTI(step, inm);
	424	while (inm != NULL) {
	425	if (inm->inm_timer == 0) {
	426	/* do nothing */
	427	} else if (--inm->inm_timer == 0) {
	428	igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
	429	inm->inm_state = IGMP_IREPORTEDLAST;
	430	} else {
	431	igmp_timers_are_running = 1;
	432	}
	433	IN_NEXT_MULTI(step, inm);
	434	}
1c79356b A	435	}
	436
	437	void
	438	igmp_slowtimo()
	439	{
91447636	440	struct router_info *rti = Head;
1c79356b A	441
	442	#if IGMP_DEBUG
	443	printf("[igmp.c,_slowtimo] -- > entering \n");
	444	#endif
	445	while (rti) {
	446	if (rti->rti_type == IGMP_V1_ROUTER) {
	447	rti->rti_time++;
	448	if (rti->rti_time >= IGMP_AGE_THRESHOLD) {
	449	rti->rti_type = IGMP_V2_ROUTER;
	450	}
	451	}
	452	rti = rti->rti_next;
	453	}
	454	#if IGMP_DEBUG
	455	printf("[igmp.c,_slowtimo] -- > exiting \n");
	456	#endif
1c79356b A	457	}
	458
	459	static struct route igmprt;
	460
	461	static void
	462	igmp_sendpkt(inm, type, addr)
	463	struct in_multi *inm;
	464	int type;
	465	unsigned long addr;
	466	{
	467	struct mbuf *m;
	468	struct igmp *igmp;
	469	struct ip *ip;
	470	struct ip_moptions imo;
	471
	472	MGETHDR(m, M_DONTWAIT, MT_HEADER);
	473	if (m == NULL)
	474	return;
	475
	476	m->m_pkthdr.rcvif = loif;
	477	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
	478	MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip));
	479	m->m_data += sizeof(struct ip);
	480	m->m_len = IGMP_MINLEN;
0b4e3aa0 A	481	m->m_pkthdr.csum_flags = 0;
0b4e3aa0 A	482	m->m_pkthdr.csum_data = 0;
1c79356b A	483	igmp = mtod(m, struct igmp *);
	484	igmp->igmp_type = type;
	485	igmp->igmp_code = 0;
	486	igmp->igmp_group = inm->inm_addr;
	487	igmp->igmp_cksum = 0;
	488	igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
	489
	490	m->m_data -= sizeof(struct ip);
	491	m->m_len += sizeof(struct ip);
	492	ip = mtod(m, struct ip *);
	493	ip->ip_tos = 0;
	494	ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
	495	ip->ip_off = 0;
	496	ip->ip_p = IPPROTO_IGMP;
	497	ip->ip_src.s_addr = INADDR_ANY;
	498	ip->ip_dst.s_addr = addr ? addr : igmp->igmp_group.s_addr;
	499
	500	imo.imo_multicast_ifp = inm->inm_ifp;
	501	imo.imo_multicast_ttl = 1;
	502	imo.imo_multicast_vif = -1;
	503	/*
	504	* Request loopback of the report if we are acting as a multicast
	505	* router, so that the process-level routing demon can hear it.
	506	*/
	507	imo.imo_multicast_loop = (ip_mrouter != NULL);
	508
	509	/*
	510	* XXX
	511	* Do we have to worry about reentrancy here? Don't think so.
	512	*/
1c79356b A	513	ip_output(m, router_alert, &igmprt, 0, &imo);
	514
	515	++igmpstat.igps_snd_reports;
	516	}