igmp.c

eCos/RedBoot for勤研ARM AnywhereII(4510) 含全部源代码

//==========================================================================
//
//      sys/netinet/igmp.c
//
//     
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD or other sources,
// and are covered by the appropriate copyright disclaimers included herein.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    gthomas
// Contributors: gthomas
// Date:         2000-01-10
// Purpose:      
// Description:  
//              
//
//####DESCRIPTIONEND####
//
//==========================================================================


/*	$OpenBSD: igmp.c,v 1.6 1999/12/08 06:50:19 itojun Exp $	*/
/*	$NetBSD: igmp.c,v 1.15 1996/02/13 23:41:25 christos Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 * 
 * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
 */

/*
 * 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.
 *
 * MULTICAST Revision: 1.3
 */

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#ifndef __ECOS
#include <sys/systm.h>
#endif

#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 __ECOS
#include <dev/rndvar.h>
#endif

#include <machine/stdarg.h>

#define IP_MULTICASTOPTS	0

int		igmp_timers_are_running;
static struct router_info *rti_head;

void igmp_sendpkt __P((struct in_multi *, int));
static int rti_fill __P((struct in_multi *));
static struct router_info * rti_find __P((struct ifnet *));

void
igmp_init()
{

	/*
	 * To avoid byte-swapping the same value over and over again.
	 */
	igmp_timers_are_running = 0;
	rti_head = 0;
}

static int
rti_fill(inm)
	struct in_multi *inm;
{
	register struct router_info *rti;

	for (rti = rti_head; rti != 0; rti = rti->rti_next) {
		if (rti->rti_ifp == inm->inm_ifp) {
			inm->inm_rti = rti;
			if (rti->rti_type == IGMP_v1_ROUTER)
				return (IGMP_v1_HOST_MEMBERSHIP_REPORT);
			else
				return (IGMP_v2_HOST_MEMBERSHIP_REPORT);
		}
	}

	rti = (struct router_info *)malloc(sizeof(struct router_info),
					   M_MRTABLE, M_NOWAIT);
	rti->rti_ifp = inm->inm_ifp;
	rti->rti_type = IGMP_v2_ROUTER;
	rti->rti_next = rti_head;
	rti_head = rti;
	inm->inm_rti = rti;
	return (IGMP_v2_HOST_MEMBERSHIP_REPORT);
}

static struct router_info *
rti_find(ifp)
	struct ifnet *ifp;
{
	register struct router_info *rti;

	for (rti = rti_head; rti != 0; rti = rti->rti_next) {
		if (rti->rti_ifp == ifp)
			return (rti);
	}

	rti = (struct router_info *)malloc(sizeof(struct router_info),
					   M_MRTABLE, M_NOWAIT);
	rti->rti_ifp = ifp;
	rti->rti_type = IGMP_v2_ROUTER;
	rti->rti_next = rti_head;
	rti_head = rti;
	return (rti);
}

void
rti_delete(ifp)
	struct ifnet *ifp;
{
	struct router_info *rti, **prti = &rti_head;

	for (rti = rti_head; rti != 0; rti = rti->rti_next) {
		if (rti->rti_ifp == ifp) {
			*prti = rti->rti_next;
			free(rti, M_MRTABLE);
			break;
		}
		prti = &rti->rti_next;
	}
}

void
#if __STDC__
igmp_input(struct mbuf *m, ...)
#else
igmp_input(m, va_alist)
	struct mbuf *m;
	va_dcl
#endif
{
	int proto;
	register int iphlen;
	register struct ifnet *ifp = m->m_pkthdr.rcvif;
	register struct ip *ip = mtod(m, struct ip *);
	register struct igmp *igmp;
	register int igmplen;
	register int minlen;
	struct in_multi *inm;
	struct in_multistep step;
	struct router_info *rti;
	register struct in_ifaddr *ia;
	int timer;
	va_list ap;

	va_start(ap, m);
	iphlen = va_arg(ap, int);
	proto = va_arg(ap, int);
	va_end(ap);

	++igmpstat.igps_rcv_total;

	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 *);

	switch (igmp->igmp_type) {

	case IGMP_HOST_MEMBERSHIP_QUERY:
		++igmpstat.igps_rcv_queries;

		if (ifp->if_flags & IFF_LOOPBACK)
			break;

		if (igmp->igmp_code == 0) {
			rti = rti_find(ifp);
			rti->rti_type = IGMP_v1_ROUTER;
			rti->rti_age = 0;

			if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) {
				++igmpstat.igps_rcv_badqueries;
				m_freem(m);
				return;
			}

			/*
			 * Start the timers in all of our membership records
			 * for the interface on which the query arrived,
			 * except those that are already running and those
			 * that belong to a "local" group (224.0.0.X).
			 */
			IN_FIRST_MULTI(step, inm);
			while (inm != NULL) {
				if (inm->inm_ifp == ifp &&
				    inm->inm_timer == 0 &&
				    !IN_LOCAL_GROUP(inm->inm_addr.s_addr)) {
					inm->inm_state = IGMP_DELAYING_MEMBER;
					inm->inm_timer = IGMP_RANDOM_DELAY(
					    IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ);
					igmp_timers_are_running = 1;
				}
				IN_NEXT_MULTI(step, inm);
			}
		} else {
			if (!IN_MULTICAST(ip->ip_dst.s_addr)) {
				++igmpstat.igps_rcv_badqueries;
				m_freem(m);
				return;
			}

			timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;

			/*
			 * Start the timers in all of our membership records
			 * for the interface on which the query arrived,
			 * except those that are already running and those
			 * that belong to a "local" group (224.0.0.X).  For
			 * timers already running, check if they need to be
			 * reset.
			 */
			IN_FIRST_MULTI(step, inm);
			while (inm != NULL) {
				if (inm->inm_ifp == ifp &&
				    !IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
				    (ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP ||
				     ip->ip_dst.s_addr == inm->inm_addr.s_addr)) {
					switch (inm->inm_state) {
					case IGMP_DELAYING_MEMBER:
						if (inm->inm_timer <= timer)
							break;
						/* FALLTHROUGH */
					case IGMP_IDLE_MEMBER:
					case IGMP_LAZY_MEMBER: