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

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * 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. 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_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	*
d7e50217	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
1c79356b	7	*
d7e50217 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
d7e50217 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
1c79356b A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/*
	26	* Copyright (c) 1988 Stephen Deering.
	27	* Copyright (c) 1992, 1993
	28	* The Regents of the University of California. All rights reserved.
	29	*
	30	* This code is derived from software contributed to Berkeley by
	31	* Stephen Deering of Stanford University.
	32	*
	33	* Redistribution and use in source and binary forms, with or without
	34	* modification, are permitted provided that the following conditions
	35	* are met:
	36	* 1. Redistributions of source code must retain the above copyright
	37	* notice, this list of conditions and the following disclaimer.
	38	* 2. Redistributions in binary form must reproduce the above copyright
	39	* notice, this list of conditions and the following disclaimer in the
	40	* documentation and/or other materials provided with the distribution.
	41	* 3. All advertising materials mentioning features or use of this software
	42	* must display the following acknowledgement:
	43	* This product includes software developed by the University of
	44	* California, Berkeley and its contributors.
	45	* 4. Neither the name of the University nor the names of its contributors
	46	* may be used to endorse or promote products derived from this software
	47	* without specific prior written permission.
	48	*
	49	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	50	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	51	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	52	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	53	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	54	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	55	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	56	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	57	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	58	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	59	* SUCH DAMAGE.
	60	*
	61	* @(#)igmp.c 8.1 (Berkeley) 7/19/93
	62	*/
	63
	64	/*
	65	* Internet Group Management Protocol (IGMP) routines.
	66	*
	67	* Written by Steve Deering, Stanford, May 1988.
	68	* Modified by Rosen Sharma, Stanford, Aug 1994.
	69	* Modified by Bill Fenner, Xerox PARC, Feb 1995.
	70	* Modified to fully comply to IGMPv2 by Bill Fenner, Oct 1995.
	71	*
	72	* MULTICAST Revision: 3.5.1.4
	73	*/
	74
	75	#include <sys/param.h>
	76	#include <sys/systm.h>
	77	#include <sys/malloc.h>
	78	#include <sys/mbuf.h>
	79	#include <sys/socket.h>
	80	#include <sys/protosw.h>
	81	#include <sys/kernel.h>
	82	#include <sys/sysctl.h>
	83
	84	#include <net/if.h>
	85	#include <net/route.h>
86
87	#include <netinet/in.h>
88	#include <netinet/in_var.h>
89	#include <netinet/in_systm.h>
90	#include <netinet/ip.h>
91	#include <netinet/ip_var.h>
92	#include <netinet/igmp.h>
93	#include <netinet/igmp_var.h>
94
9bccf70c	95	#ifndef __APPLE__
1c79356b	96	static MALLOC_DEFINE(M_IGMP, "igmp", "igmp state");
9bccf70c	97	#endif
1c79356b A	98
	99	static struct router_info *
	100	find_rti __P((struct ifnet *ifp));
	101
	102	static struct igmpstat igmpstat;
	103
	104	SYSCTL_STRUCT(_net_inet_igmp, IGMPCTL_STATS, stats, CTLFLAG_RD,
	105	&igmpstat, igmpstat, "");
	106
	107	static int igmp_timers_are_running;
	108	static u_long igmp_all_hosts_group;
	109	static u_long igmp_all_rtrs_group;
	110	static struct mbuf *router_alert;
	111	static struct router_info *Head;
	112
	113	static void igmp_sendpkt __P((struct in_multi *, int, unsigned long));
	114
	115	void
	116	igmp_init()
	117	{
	118	struct ipoption *ra;
	119
	120	/*
	121	* To avoid byte-swapping the same value over and over again.
	122	*/
	123	igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
	124	igmp_all_rtrs_group = htonl(INADDR_ALLRTRS_GROUP);
	125
	126	igmp_timers_are_running = 0;
	127
	128	/*
	129	* Construct a Router Alert option to use in outgoing packets
	130	*/
	131	MGET(router_alert, M_DONTWAIT, MT_DATA);
	132	ra = mtod(router_alert, struct ipoption *);
	133	ra->ipopt_dst.s_addr = 0;
	134	ra->ipopt_list[0] = IPOPT_RA; /* Router Alert Option */
	135	ra->ipopt_list[1] = 0x04; /* 4 bytes long */
	136	ra->ipopt_list[2] = 0x00;
	137	ra->ipopt_list[3] = 0x00;
	138	router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1];
	139
	140	Head = (struct router_info *) 0;
	141	}
	142
	143	static struct router_info *
	144	find_rti(ifp)
	145	struct ifnet *ifp;
	146	{
	147	register struct router_info *rti = Head;
	148
	149	#if IGMP_DEBUG
	150	printf("[igmp.c, _find_rti] --> entering \n");
	151	#endif
	152	while (rti) {
	153	if (rti->rti_ifp == ifp) {
	154	#if IGMP_DEBUG
	155	printf("[igmp.c, _find_rti] --> found old entry \n");
	156	#endif
	157	return rti;
	158	}
	159	rti = rti->rti_next;
	160	}
	161
1c79356b	162	MALLOC(rti, struct router_info , sizeof rti, M_IGMP, M_NOWAIT);
1c79356b A	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	#if IGMP_DEBUG
	169	printf("[igmp.c, _find_rti] --> created an entry \n");
	170	#endif
	171	return rti;
	172	}
	173
	174	void
	175	igmp_input(m, iphlen)
	176	register struct mbuf *m;
	177	register int iphlen;
	178	{
	179	register struct igmp *igmp;
	180	register struct ip *ip;
	181	register int igmplen;
	182	register struct ifnet *ifp = m->m_pkthdr.rcvif;
	183	register int minlen;
	184	register struct in_multi *inm;
	185	register struct in_ifaddr *ia;
	186	struct in_multistep step;
	187	struct router_info *rti;
	188
	189	int timer; / timer value in the igmp query header /
	190
	191	++igmpstat.igps_rcv_total;
	192
	193	ip = mtod(m, struct ip *);
	194	igmplen = ip->ip_len;
	195
	196	/*
	197	* Validate lengths
	198	*/
	199	if (igmplen < IGMP_MINLEN) {
	200	++igmpstat.igps_rcv_tooshort;
	201	m_freem(m);
	202	return;
	203	}
	204	minlen = iphlen + IGMP_MINLEN;
	205	if ((m->m_flags & M_EXT \|\| m->m_len < minlen) &&
	206	(m = m_pullup(m, minlen)) == 0) {
	207	++igmpstat.igps_rcv_tooshort;
	208	return;
	209	}
	210
	211	/*
	212	* Validate checksum
	213	*/
	214	m->m_data += iphlen;
	215	m->m_len -= iphlen;
	216	igmp = mtod(m, struct igmp *);
	217	if (in_cksum(m, igmplen)) {
	218	++igmpstat.igps_rcv_badsum;
	219	m_freem(m);
	220	return;
	221	}
	222	m->m_data -= iphlen;
	223	m->m_len += iphlen;
	224
	225	ip = mtod(m, struct ip *);
	226	timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
227	if (timer == 0)
228	timer = 1;
229	rti = find_rti(ifp);
230
231	/*
232	* In the IGMPv2 specification, there are 3 states and a flag.
233	*
234	* In Non-Member state, we simply don't have a membership record.
235	* In Delaying Member state, our timer is running (inm->inm_timer)
236	* In Idle Member state, our timer is not running (inm->inm_timer==0)
237	*
238	* The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
239	* we have heard a report from another member, or IGMP_IREPORTEDLAST
240	* if I sent the last report.
241	*/
242	switch (igmp->igmp_type) {
243
244	case IGMP_MEMBERSHIP_QUERY:
245	++igmpstat.igps_rcv_queries;
246
247	if (ifp->if_flags & IFF_LOOPBACK)
248	break;
249
250	if (igmp->igmp_code == 0) {
251	/*
252	* Old router. Remember that the querier on this
253	* interface is old, and set the timer to the
254	* value in RFC 1112.
255	*/
256
257	rti->rti_type = IGMP_V1_ROUTER;
258	rti->rti_time = 0;
259
260	timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;
261
262	if (ip->ip_dst.s_addr != igmp_all_hosts_group \|\|
263	igmp->igmp_group.s_addr != 0) {
264	++igmpstat.igps_rcv_badqueries;
265	m_freem(m);
266	return;
267	}
268	} else {
269	/*
270	* New router. Simply do the new validity check.
271	*/
272
273	if (igmp->igmp_group.s_addr != 0 &&
274	!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
275	++igmpstat.igps_rcv_badqueries;
276	m_freem(m);
277	return;
278	}
279	}
280
281	/*
282	* - Start the timers in all of our membership records
283	* that the query applies to for the interface on
284	* which the query arrived excl. those that belong
285	* to the "all-hosts" group (224.0.0.1).
286	* - Restart any timer that is already running but has
287	* a value longer than the requested timeout.
288	* - Use the value specified in the query message as
289	* the maximum timeout.
290	*/
291	IN_FIRST_MULTI(step, inm);
292	while (inm != NULL) {
293	if (inm->inm_ifp == ifp &&
294	inm->inm_addr.s_addr != igmp_all_hosts_group &&
295	(igmp->igmp_group.s_addr == 0 \|\|
296	igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
297	if (inm->inm_timer == 0 \|\|
298	inm->inm_timer > timer) {
299	inm->inm_timer =
300	IGMP_RANDOM_DELAY(timer);
301	igmp_timers_are_running = 1;
302	}
303	}
304	IN_NEXT_MULTI(step, inm);
305	}
306
307	break;
308
309	case IGMP_V1_MEMBERSHIP_REPORT:
310	case IGMP_V2_MEMBERSHIP_REPORT:
311	/*
312	* For fast leave to work, we have to know that we are the
313	* last person to send a report for this group. Reports
314	* can potentially get looped back if we are a multicast
315	* router, so discard reports sourced by me.
316	*/
317	IFP_TO_IA(ifp, ia);
318	if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr)
319	break;
320
321	++igmpstat.igps_rcv_reports;
322
323	if (ifp->if_flags & IFF_LOOPBACK)
324	break;
325
326	if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
327	++igmpstat.igps_rcv_badreports;
328	m_freem(m);
329	return;
330	}
331
332	/*
333	* KLUDGE: if the IP source address of the report has an
334	* unspecified (i.e., zero) subnet number, as is allowed for
335	* a booting host, replace it with the correct subnet number
336	* so that a process-level multicast routing demon can
337	* determine which subnet it arrived from. This is necessary
338	* to compensate for the lack of any way for a process to
339	* determine the arrival interface of an incoming packet.
340	*/
341	if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0)
342	if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
343
344	/*
345	* If we belong to the group being reported, stop
346	* our timer for that group.
347	*/
348	IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
349
350	if (inm != NULL) {
351	inm->inm_timer = 0;
352	++igmpstat.igps_rcv_ourreports;
353
354	inm->inm_state = IGMP_OTHERMEMBER;
355	}
356
357	break;
358	}
359
360	/*
361	* Pass all valid IGMP packets up to any process(es) listening
362	* on a raw IGMP socket.
363	*/
364	rip_input(m, iphlen);
365	}
366
367	void
368	igmp_joingroup(inm)
369	struct in_multi *inm;
370	{
371	int s = splnet();
372
373	if (inm->inm_addr.s_addr == igmp_all_hosts_group
374	\|\| inm->inm_ifp->if_flags & IFF_LOOPBACK) {
375	inm->inm_timer = 0;
376	inm->inm_state = IGMP_OTHERMEMBER;
377	} else {
378	inm->inm_rti = find_rti(inm->inm_ifp);
379	igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
380	inm->inm_timer = IGMP_RANDOM_DELAY(
381	IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
382	inm->inm_state = IGMP_IREPORTEDLAST;
383	igmp_timers_are_running = 1;
384	}
385	splx(s);
386	}
387
388	void
389	igmp_leavegroup(inm)
390	struct in_multi *inm;
391	{
392	if (inm->inm_state == IGMP_IREPORTEDLAST &&
393	inm->inm_addr.s_addr != igmp_all_hosts_group &&
394	!(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
395	inm->inm_rti->rti_type != IGMP_V1_ROUTER)
396	igmp_sendpkt(inm, IGMP_V2_LEAVE_GROUP, igmp_all_rtrs_group);
397	}
398
399	void
400	igmp_fasttimo()
401	{
402	register struct in_multi *inm;
403	struct in_multistep step;
404	int s;
405
406	/*
407	* Quick check to see if any work needs to be done, in order
408	* to minimize the overhead of fasttimo processing.
409	*/
410
411	if (!igmp_timers_are_running)
412	return;
413
414	s = splnet();
415	igmp_timers_are_running = 0;
416	IN_FIRST_MULTI(step, inm);
417	while (inm != NULL) {
418	if (inm->inm_timer == 0) {
419	/* do nothing */
420	} else if (--inm->inm_timer == 0) {
421	igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
422	inm->inm_state = IGMP_IREPORTEDLAST;
423	} else {
424	igmp_timers_are_running = 1;
425	}
426	IN_NEXT_MULTI(step, inm);
427	}
428	splx(s);
429	}
430
431	void
432	igmp_slowtimo()
433	{
434	int s = splnet();
435	register struct router_info *rti = Head;
436
437	#if IGMP_DEBUG
438	printf("[igmp.c,_slowtimo] -- > entering \n");
439	#endif
440	while (rti) {
441	if (rti->rti_type == IGMP_V1_ROUTER) {
442	rti->rti_time++;
443	if (rti->rti_time >= IGMP_AGE_THRESHOLD) {
444	rti->rti_type = IGMP_V2_ROUTER;
445	}
446	}
447	rti = rti->rti_next;
448	}
449	#if IGMP_DEBUG
450	printf("[igmp.c,_slowtimo] -- > exiting \n");
451	#endif
452	splx(s);
453	}
454
455	static struct route igmprt;
456
457	static void
458	igmp_sendpkt(inm, type, addr)
459	struct in_multi *inm;
460	int type;
461	unsigned long addr;
462	{
463	struct mbuf *m;
464	struct igmp *igmp;
465	struct ip *ip;
466	struct ip_moptions imo;
467
468	MGETHDR(m, M_DONTWAIT, MT_HEADER);
469	if (m == NULL)
470	return;
471
472	m->m_pkthdr.rcvif = loif;
473	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
474	MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip));
475	m->m_data += sizeof(struct ip);
476	m->m_len = IGMP_MINLEN;
0b4e3aa0 A	477	m->m_pkthdr.csum_flags = 0;
0b4e3aa0 A	478	m->m_pkthdr.csum_data = 0;
1c79356b A	479	igmp = mtod(m, struct igmp *);
	480	igmp->igmp_type = type;
	481	igmp->igmp_code = 0;
	482	igmp->igmp_group = inm->inm_addr;
	483	igmp->igmp_cksum = 0;
	484	igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
	485
	486	m->m_data -= sizeof(struct ip);
	487	m->m_len += sizeof(struct ip);
	488	ip = mtod(m, struct ip *);
	489	ip->ip_tos = 0;
	490	ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
	491	ip->ip_off = 0;
	492	ip->ip_p = IPPROTO_IGMP;
	493	ip->ip_src.s_addr = INADDR_ANY;
	494	ip->ip_dst.s_addr = addr ? addr : igmp->igmp_group.s_addr;
	495
	496	imo.imo_multicast_ifp = inm->inm_ifp;
	497	imo.imo_multicast_ttl = 1;
	498	imo.imo_multicast_vif = -1;
	499	/*
	500	* Request loopback of the report if we are acting as a multicast
	501	* router, so that the process-level routing demon can hear it.
	502	*/
	503	imo.imo_multicast_loop = (ip_mrouter != NULL);
	504
	505	/*
	506	* XXX
	507	* Do we have to worry about reentrancy here? Don't think so.
	508	*/
1c79356b A	509	ip_output(m, router_alert, &igmprt, 0, &imo);
	510
	511	++igmpstat.igps_snd_reports;
	512	}