/* igmp.c - internet group management protocol routines *//* Copyright 1984-1996 Wind River Systems, Inc. *//* * 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	8.2 (Berkeley) 5/3/95 *//*modification history--------------------01e,05oct97,vin  changes for multicast hashing.01d,08mar97,vin  added mCastRouteFwdHook to access mcast routing code.01c,31jan97,vin  changed declaration according to prototype decl in protosw.h01b,11nov96,vin  added cluster support, changed m_gethdr mHdlClGet.01a,03mar96,vin  created from BSD4.4 stuff.*//* Internet Group Management Protocol (IGMP) routines. */#include "vxWorks.h"#include "errno.h"#include "net/mbuf.h"#include "sys/socket.h"#include "net/protosw.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"#include "net/systm.h"/* externs */extern struct ifnet loif;extern VOIDFUNCPTR _igmpJoinGrpHook; extern VOIDFUNCPTR _igmpLeaveGrpHook; extern FUNCPTR _mCastRouteFwdHook;	/* WRS mcast forward command hook *//* globals */struct igmpstat igmpstat;static int igmp_timers_are_running = 0;static u_long igmp_all_hosts_group;static void igmp_sendreport (struct in_multi *);static void igmp_joingroup (struct in_multi *inm);static void igmp_leavegroup (struct in_multi *inm);voidigmp_init(){	/*	 * To avoid byte-swapping the same value over and over again.	 */	igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);	_igmpJoinGrpHook = igmp_joingroup; 	_igmpLeaveGrpHook = igmp_leavegroup;	return;}voidigmp_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;	++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 *);	switch (igmp->igmp_type) {	case IGMP_HOST_MEMBERSHIP_QUERY:		++igmpstat.igps_rcv_queries;		if (ifp == &loif)			break;		if (ip->ip_dst.s_addr != igmp_all_hosts_group) {			++igmpstat.igps_rcv_badqueries;			m_freem(m);			return;		}                {                IN_MULTI_HEAD * inMultiHead;                int		ix;                for (ix = 0; ix <= mCastHashInfo.hashMask; ix++)                    {                    inMultiHead = &mCastHashInfo.hashBase [ix];                    if (inMultiHead != NULL)                        {                        for (inm = inMultiHead->lh_first;                             inm != NULL;                             inm = inm->inm_hash.le_next)                            {                            if (inm->inm_ifp == ifp && inm->inm_timer == 0 &&                                inm->inm_addr.s_addr != igmp_all_hosts_group)                                {                                inm->inm_timer =                                    	IGMP_RANDOM_DELAY(inm->inm_addr);				igmp_timers_are_running = 1;                                }                            }                        }                    }                }		break;	case IGMP_HOST_MEMBERSHIP_REPORT:		++igmpstat.igps_rcv_reports;		if (ifp == &loif)			break;		if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) ||		    igmp->igmp_group.s_addr != ip->ip_dst.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) {			IFP_TO_IA(ifp, ia);			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;		}		break;	}	/*	 * Pass all valid IGMP packets up to any process(es) listening	 * on a raw IGMP socket.	 */	rip_input(m);	return;}static voidigmp_joingroup(inm)	struct in_multi *inm;{	register int s = splnet();	if (inm->inm_addr.s_addr == igmp_all_hosts_group ||	    inm->inm_ifp == &loif)		inm->inm_timer = 0;	else {		igmp_sendreport(inm);		inm->inm_timer = IGMP_RANDOM_DELAY(inm->inm_addr);		igmp_timers_are_running = 1;	}	splx(s);}static voidigmp_leavegroup(inm)	struct in_multi *inm;{	/*	 * No action required on leaving a group.	 */}voidigmp_fasttimo(){	register struct in_multi *inm;	register 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_MULTI_HEAD * inMultiHead;        int		ix;        for (ix = 0; ix <= mCastHashInfo.hashMask; ix++)            {            inMultiHead = &mCastHashInfo.hashBase [ix];            if (inMultiHead != NULL)                {                for (inm = inMultiHead->lh_first;                     inm != NULL;                     inm = inm->inm_hash.le_next)                    {                    if (inm->inm_timer == 0)                        {                        /* do nothing */                        }                    else if (--inm->inm_timer == 0)                        {                        igmp_sendreport(inm);                        }                    else                        {                        igmp_timers_are_running = 1;                        }                    }                }            }        }	splx(s);	return;}static voidigmp_sendreport(inm)	register struct in_multi *inm;{	register struct mbuf *m;	register struct igmp *igmp;	register struct ip *ip;	register struct ip_moptions *imo;	struct ip_moptions simo;	m= mHdrClGet(M_DONTWAIT, MT_HEADER, CL_SIZE_128, TRUE);	if (m == NULL)		return;	/*	 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN	 * is smaller than mbuf size returned by MGETHDR.	 */	m->m_data += max_linkhdr;	m->m_len = sizeof(struct ip) + IGMP_MINLEN;	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;	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 = inm->inm_addr;	m->m_data += sizeof(struct ip);	m->m_len -= sizeof(struct ip);	igmp = mtod(m, struct igmp *);	igmp->igmp_type = IGMP_HOST_MEMBERSHIP_REPORT;	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);	imo = &simo;	bzero((caddr_t)imo, sizeof(*imo));	imo->imo_multicast_ifp = inm->inm_ifp;	imo->imo_multicast_ttl = 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 = (_mCastRouteFwdHook != NULL);	ip_output(m, NULL, NULL, 0, imo);	++igmpstat.igps_snd_reports;}