Subversion Repositories or1k

/*
 *	Linux NET3:	Internet Group Management Protocol  [IGMP]
 *
 *	This code implements the IGMP protocol as defined in RFC1112. There has
 *	been a further revision of this protocol since which is now supported.
 *
 *	If you have trouble with this module be careful what gcc you have used,
 *	the older version didn't come out right using gcc 2.5.8, the newer one
 *	seems to fall out with gcc 2.6.2.
 *
 *	Version: $Id: igmp.c,v 1.1.1.1 2004-04-15 01:13:48 phoenix Exp $
 *
 *	Authors:
 *		Alan Cox <Alan.Cox@linux.org>
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *	Fixes:
 *
 *		Alan Cox	:	Added lots of __inline__ to optimise
 *					the memory usage of all the tiny little
 *					functions.
 *		Alan Cox	:	Dumped the header building experiment.
 *		Alan Cox	:	Minor tweaks ready for multicast routing
 *					and extended IGMP protocol.
 *		Alan Cox	:	Removed a load of inline directives. Gcc 2.5.8
 *					writes utterly bogus code otherwise (sigh)
 *					fixed IGMP loopback to behave in the manner
 *					desired by mrouted, fixed the fact it has been
 *					broken since 1.3.6 and cleaned up a few minor
 *					points.
 *
 *		Chih-Jen Chang	:	Tried to revise IGMP to Version 2
 *		Tsu-Sheng Tsao		E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu
 *					The enhancements are mainly based on Steve Deering's 
 * 					ipmulti-3.5 source code.
 *		Chih-Jen Chang	:	Added the igmp_get_mrouter_info and
 *		Tsu-Sheng Tsao		igmp_set_mrouter_info to keep track of
 *					the mrouted version on that device.
 *		Chih-Jen Chang	:	Added the max_resp_time parameter to
 *		Tsu-Sheng Tsao		igmp_heard_query(). Using this parameter
 *					to identify the multicast router version
 *					and do what the IGMP version 2 specified.
 *		Chih-Jen Chang	:	Added a timer to revert to IGMP V2 router
 *		Tsu-Sheng Tsao		if the specified time expired.
 *		Alan Cox	:	Stop IGMP from 0.0.0.0 being accepted.
 *		Alan Cox	:	Use GFP_ATOMIC in the right places.
 *		Christian Daudt :	igmp timer wasn't set for local group
 *					memberships but was being deleted, 
 *					which caused a "del_timer() called 
 *					from %p with timer not initialized\n"
 *					message (960131).
 *		Christian Daudt :	removed del_timer from 
 *					igmp_timer_expire function (960205).
 *             Christian Daudt :       igmp_heard_report now only calls
 *                                     igmp_timer_expire if tm->running is
 *                                     true (960216).
 *		Malcolm Beattie :	ttl comparison wrong in igmp_rcv made
 *					igmp_heard_query never trigger. Expiry
 *					miscalculation fixed in igmp_heard_query
 *					and random() made to return unsigned to
 *					prevent negative expiry times.
 *		Alexey Kuznetsov:	Wrong group leaving behaviour, backport
 *					fix from pending 2.1.x patches.
 *		Alan Cox:		Forget to enable FDDI support earlier.
 *		Alexey Kuznetsov:	Fixed leaving groups on device down.
 *		Alexey Kuznetsov:	Accordance to igmp-v2-06 draft.
 *		David L Stevens:	IGMPv3 support, with help from
 *					Vinay Kulkarni
 */
 
 
#include <linux/config.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/if_arp.h>
#include <linux/rtnetlink.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/route.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4.h>
#ifdef CONFIG_IP_MROUTE
#include <linux/mroute.h>
#endif
 
 
#define IP_MAX_MEMBERSHIPS	20
#define IP_MAX_MSF		10
 
#ifdef CONFIG_IP_MULTICAST
/* Parameter names and values are taken from igmp-v2-06 draft */
 
#define IGMP_V1_Router_Present_Timeout		(400*HZ)
#define IGMP_V2_Router_Present_Timeout		(400*HZ)
#define IGMP_Unsolicited_Report_Interval	(10*HZ)
#define IGMP_Query_Response_Interval		(10*HZ)
#define IGMP_Unsolicited_Report_Count		2
 
 
#define IGMP_Initial_Report_Delay		(1)
 
/* IGMP_Initial_Report_Delay is not from IGMP specs!
 * IGMP specs require to report membership immediately after
 * joining a group, but we delay the first report by a
 * small interval. It seems more natural and still does not
 * contradict to specs provided this delay is small enough.
 */
 
#define IGMP_V1_SEEN(in_dev) (ipv4_devconf.force_igmp_version == 1 || \
		(in_dev)->cnf.force_igmp_version == 1 || \
		((in_dev)->mr_v1_seen && \
		time_before(jiffies, (in_dev)->mr_v1_seen)))
#define IGMP_V2_SEEN(in_dev) (ipv4_devconf.force_igmp_version == 2 || \
		(in_dev)->cnf.force_igmp_version == 2 || \
		((in_dev)->mr_v2_seen && \
		time_before(jiffies, (in_dev)->mr_v2_seen)))
 
static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im);
static void igmpv3_del_delrec(struct in_device *in_dev, __u32 multiaddr);
static void igmpv3_clear_delrec(struct in_device *in_dev);
static int sf_setstate(struct ip_mc_list *pmc);
static void sf_markstate(struct ip_mc_list *pmc);
#endif
static void ip_mc_clear_src(struct ip_mc_list *pmc);
int ip_mc_add_src(struct in_device *in_dev, __u32 *pmca, int sfmode,
	int sfcount, __u32 *psfsrc, int delta);
 
static void ip_ma_put(struct ip_mc_list *im)
{
	if (atomic_dec_and_test(&im->refcnt)) {
		in_dev_put(im->interface);
		kfree(im);
	}
}
 
#ifdef CONFIG_IP_MULTICAST
 
/*
 *	Timer management
 */
 
static __inline__ void igmp_stop_timer(struct ip_mc_list *im)
{
	spin_lock_bh(&im->lock);
	if (del_timer(&im->timer))
		atomic_dec(&im->refcnt);
	im->tm_running=0;
	im->reporter = 0;
	im->unsolicit_count = 0;
	spin_unlock_bh(&im->lock);
}
 
/* It must be called with locked im->lock */
static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
{
	int tv=net_random() % max_delay;
 
	im->tm_running=1;
	if (!mod_timer(&im->timer, jiffies+tv+2))
		atomic_inc(&im->refcnt);
}
 
static void igmp_gq_start_timer(struct in_device *in_dev)
{
	int tv = net_random() % in_dev->mr_maxdelay;
 
	in_dev->mr_gq_running = 1;
	if (!mod_timer(&in_dev->mr_gq_timer, jiffies+tv+2))
		in_dev_hold(in_dev);
}
 
static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
{
	int tv = net_random() % delay;
 
	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
		in_dev_hold(in_dev);
}
 
static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
{
	spin_lock_bh(&im->lock);
	im->unsolicit_count = 0;
	if (del_timer(&im->timer)) {
		if ((long)(im->timer.expires-jiffies) < max_delay) {
			add_timer(&im->timer);
			im->tm_running=1;
			spin_unlock_bh(&im->lock);
			return;
		}
		atomic_dec(&im->refcnt);
	}
	igmp_start_timer(im, max_delay);
	spin_unlock_bh(&im->lock);
}
 
 
/*
 *	Send an IGMP report.
 */
 
#define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
 
/* Don't just hand NF_HOOK skb->dst->output, in case netfilter hook
   changes route */
static inline int
output_maybe_reroute(struct sk_buff *skb)
{
	return skb->dst->output(skb);
}
 
 
static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
	int gdeleted, int sdeleted)
{
	switch (type) {
	case IGMPV3_MODE_IS_INCLUDE:
	case IGMPV3_MODE_IS_EXCLUDE:
		if (gdeleted || sdeleted)
			return 0;
		return !(pmc->gsquery && !psf->sf_gsresp);
	case IGMPV3_CHANGE_TO_INCLUDE:
		if (gdeleted || sdeleted)
			return 0;
		return psf->sf_count[MCAST_INCLUDE] != 0;
	case IGMPV3_CHANGE_TO_EXCLUDE:
		if (gdeleted || sdeleted)
			return 0;
		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
		    psf->sf_count[MCAST_INCLUDE])
			return 0;
		return pmc->sfcount[MCAST_EXCLUDE] ==
			psf->sf_count[MCAST_EXCLUDE];
	case IGMPV3_ALLOW_NEW_SOURCES:
		if (gdeleted || !psf->sf_crcount)
			return 0;
		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
	case IGMPV3_BLOCK_OLD_SOURCES:
		if (pmc->sfmode == MCAST_INCLUDE)
			return gdeleted || (psf->sf_crcount && sdeleted);
		return psf->sf_crcount && !gdeleted && !sdeleted;
	}
	return 0;
}
 
static int
igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
{
	struct ip_sf_list *psf;
	int scount = 0;
 
	for (psf=pmc->sources; psf; psf=psf->sf_next) {
		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
			continue;
		scount++;
	}
	return scount;
}
 
static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
{
	struct sk_buff *skb;
	struct rtable *rt;
	struct iphdr *pip;
	struct igmpv3_report *pig;
	u32	dst;
 
	dst = IGMPV3_ALL_MCR;
	if (ip_route_output(&rt, dst, 0, 0, dev->ifindex))
		return 0;
	if (rt->rt_src == 0) {
		ip_rt_put(rt);
		return 0;
	}
	skb = alloc_skb(size + dev->hard_header_len + 15, GFP_ATOMIC);
	if (skb == NULL) {
		ip_rt_put(rt);
		return 0;
	}
 
	skb->dst = &rt->u.dst;
	skb->dev = dev;
 
	skb_reserve(skb, (dev->hard_header_len+15)&~15);
 
	skb->nh.iph = pip =(struct iphdr *)skb_put(skb, sizeof(struct iphdr)+4);
 
	pip->version  = 4;
	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
	pip->tos      = 0xc0;
	pip->frag_off = htons(IP_DF);
	pip->ttl      = 1;
	pip->daddr    = rt->rt_dst;
	pip->saddr    = rt->rt_src;
	pip->protocol = IPPROTO_IGMP;
	pip->tot_len  = 0;	/* filled in later */
	ip_select_ident(pip, &rt->u.dst, NULL);
	((u8*)&pip[1])[0] = IPOPT_RA;
	((u8*)&pip[1])[1] = 4;
	((u8*)&pip[1])[2] = 0;
	((u8*)&pip[1])[3] = 0;
 
	pig =(struct igmpv3_report *)skb_put(skb, sizeof(*pig));
	skb->h.igmph = (struct igmphdr *)pig;
	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
	pig->resv1 = 0;
	pig->csum = 0;
	pig->resv2 = 0;
	pig->ngrec = 0;
	return skb;
}
 
static int igmpv3_sendpack(struct sk_buff *skb)
{
	struct iphdr *pip = skb->nh.iph;
	struct igmphdr *pig = skb->h.igmph;
	int iplen, igmplen;
 
	iplen = skb->tail - (unsigned char *)skb->nh.iph;
	pip->tot_len = htons(iplen);
	ip_send_check(pip);
 
	igmplen = skb->tail - (unsigned char *)skb->h.igmph;
	pig->csum = ip_compute_csum((void *)skb->h.igmph, igmplen);
 
	return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, skb->dev,
		       output_maybe_reroute);
}
 
static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
{
	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc,type,gdel,sdel);
}
 
static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
	int type, struct igmpv3_grec **ppgr)
{
	struct net_device *dev = pmc->interface->dev;
	struct igmpv3_report *pih;
	struct igmpv3_grec *pgr;
 
	if (!skb)
		skb = igmpv3_newpack(dev, dev->mtu);
	if (!skb)
		return 0;
	pgr = (struct igmpv3_grec *)skb_put(skb, sizeof(struct igmpv3_grec));
	pgr->grec_type = type;
	pgr->grec_auxwords = 0;
	pgr->grec_nsrcs = 0;
	pgr->grec_mca = pmc->multiaddr;
	pih = (struct igmpv3_report *)skb->h.igmph;
	pih->ngrec = htons(ntohs(pih->ngrec)+1);
	*ppgr = pgr;
	return skb;
}
 
#define AVAILABLE(skb) ((skb) ? ((skb)->dev ? (skb)->dev->mtu - (skb)->len : \
	skb_tailroom(skb)) : 0)
 
static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
	int type, int gdeleted, int sdeleted)
{
	struct net_device *dev = pmc->interface->dev;
	struct igmpv3_report *pih;
	struct igmpv3_grec *pgr = 0;
	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
	int scount, first, isquery, truncate;
 
	if (pmc->multiaddr == IGMP_ALL_HOSTS)
		return skb;
 
	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
		  type == IGMPV3_MODE_IS_EXCLUDE;
	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
		    type == IGMPV3_CHANGE_TO_EXCLUDE;
 
	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
 
	if (!*psf_list) {
		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
		    type == IGMPV3_BLOCK_OLD_SOURCES)
			return skb;
		if (pmc->crcount || isquery) {
			/* make sure we have room for group header and at
			 * least one source.
			 */
			if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)+
			    sizeof(__u32)) {
				igmpv3_sendpack(skb);
				skb = 0; /* add_grhead will get a new one */
			}
			skb = add_grhead(skb, pmc, type, &pgr);
		}
		return skb;
	}
	pih = skb ? (struct igmpv3_report *)skb->h.igmph : 0;
 
	/* EX and TO_EX get a fresh packet, if needed */
	if (truncate) {
		if (pih && pih->ngrec &&
		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
			if (skb)
				igmpv3_sendpack(skb);
			skb = igmpv3_newpack(dev, dev->mtu);
		}
	}
	first = 1;
	scount = 0;
	psf_prev = 0;
	for (psf=*psf_list; psf; psf=psf_next) {
		u32 *psrc;
 
		psf_next = psf->sf_next;
 
		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
			psf_prev = psf;
			continue;
		}
 
		/* clear marks on query responses */
		if (isquery)
			psf->sf_gsresp = 0;
 
		if (AVAILABLE(skb) < sizeof(u32) +
		    first*sizeof(struct igmpv3_grec)) {
			if (truncate && !first)
				break;	 /* truncate these */
			if (pgr)
				pgr->grec_nsrcs = htons(scount);
			if (skb)
				igmpv3_sendpack(skb);
			skb = igmpv3_newpack(dev, dev->mtu);
			first = 1;
			scount = 0;
		}
		if (first) {
			skb = add_grhead(skb, pmc, type, &pgr);
			first = 0;
		}
		psrc = (u32 *)skb_put(skb, sizeof(u32));
		*psrc = psf->sf_inaddr;
		scount++;
		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
			psf->sf_crcount--;
			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
				if (psf_prev)
					psf_prev->sf_next = psf->sf_next;
				else
					*psf_list = psf->sf_next;
				kfree(psf);
				continue;
			}
		}
		psf_prev = psf;
	}
	if (pgr)
		pgr->grec_nsrcs = htons(scount);
 
	if (isquery)
		pmc->gsquery = 0;	/* clear query state on report */
	return skb;
}
 
static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
{
	struct sk_buff *skb = 0;
	int type;
 
	if (!pmc) {
		read_lock(&in_dev->lock);
		for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
			if (pmc->multiaddr == IGMP_ALL_HOSTS)
				continue;
			spin_lock_bh(&pmc->lock);
			if (pmc->sfcount[MCAST_EXCLUDE])
				type = IGMPV3_MODE_IS_EXCLUDE;
			else
				type = IGMPV3_MODE_IS_INCLUDE;
			skb = add_grec(skb, pmc, type, 0, 0);
			spin_unlock_bh(&pmc->lock);
		}
		read_unlock(&in_dev->lock);
	} else {
		spin_lock_bh(&pmc->lock);
		if (pmc->sfcount[MCAST_EXCLUDE])
			type = IGMPV3_MODE_IS_EXCLUDE;
		else
			type = IGMPV3_MODE_IS_INCLUDE;
		skb = add_grec(skb, pmc, type, 0, 0);
		spin_unlock_bh(&pmc->lock);
	}
	if (!skb)
		return 0;
	return igmpv3_sendpack(skb);
}
 
/*
 * remove zero-count source records from a source filter list
 */
static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
{
	struct ip_sf_list *psf_prev, *psf_next, *psf;
 
	psf_prev = 0;
	for (psf=*ppsf; psf; psf = psf_next) {
		psf_next = psf->sf_next;
		if (psf->sf_crcount == 0) {
			if (psf_prev)
				psf_prev->sf_next = psf->sf_next;
			else
				*ppsf = psf->sf_next;
			kfree(psf);
		} else
			psf_prev = psf;
	}
}
 
static void igmpv3_send_cr(struct in_device *in_dev)
{
	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
	struct sk_buff *skb = 0;
	int type, dtype;
 
	read_lock(&in_dev->lock);
	write_lock_bh(&in_dev->mc_lock);
 
	/* deleted MCA's */
	pmc_prev = 0;
	for (pmc=in_dev->mc_tomb; pmc; pmc=pmc_next) {
		pmc_next = pmc->next;
		if (pmc->sfmode == MCAST_INCLUDE) {
			type = IGMPV3_BLOCK_OLD_SOURCES;
			dtype = IGMPV3_BLOCK_OLD_SOURCES;
			skb = add_grec(skb, pmc, type, 1, 0);
			skb = add_grec(skb, pmc, dtype, 1, 1);
		}
		if (pmc->crcount) {
			pmc->crcount--;
			if (pmc->sfmode == MCAST_EXCLUDE) {
				type = IGMPV3_CHANGE_TO_INCLUDE;
				skb = add_grec(skb, pmc, type, 1, 0);
			}
			if (pmc->crcount == 0) {
				igmpv3_clear_zeros(&pmc->tomb);
				igmpv3_clear_zeros(&pmc->sources);
			}
		}
		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
			if (pmc_prev)
				pmc_prev->next = pmc_next;
			else
				in_dev->mc_tomb = pmc_next;
			in_dev_put(pmc->interface);
			kfree(pmc);
		} else
			pmc_prev = pmc;
	}
	write_unlock_bh(&in_dev->mc_lock);
 
	/* change recs */
	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
		spin_lock_bh(&pmc->lock);
		if (pmc->sfcount[MCAST_EXCLUDE]) {
			type = IGMPV3_BLOCK_OLD_SOURCES;
			dtype = IGMPV3_ALLOW_NEW_SOURCES;
		} else {
			type = IGMPV3_ALLOW_NEW_SOURCES;
			dtype = IGMPV3_BLOCK_OLD_SOURCES;
		}
		skb = add_grec(skb, pmc, type, 0, 0);
		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
 
		/* filter mode changes */
		if (pmc->crcount) {
			pmc->crcount--;
			if (pmc->sfmode == MCAST_EXCLUDE)
				type = IGMPV3_CHANGE_TO_EXCLUDE;
			else
				type = IGMPV3_CHANGE_TO_INCLUDE;
			skb = add_grec(skb, pmc, type, 0, 0);
		}
		spin_unlock_bh(&pmc->lock);
	}
	read_unlock(&in_dev->lock);
	if (!skb)
		return;
	(void) igmpv3_sendpack(skb);
}
 
static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
	int type)
{
	struct sk_buff *skb;
	struct iphdr *iph;
	struct igmphdr *ih;
	struct rtable *rt;
	struct net_device *dev = in_dev->dev;
	u32	group = pmc ? pmc->multiaddr : 0;
	u32	dst;
 
	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
		return igmpv3_send_report(in_dev, pmc);
	else if (type == IGMP_HOST_LEAVE_MESSAGE)
		dst = IGMP_ALL_ROUTER;
	else
		dst = group;
 
	if (ip_route_output(&rt, dst, 0, 0, dev->ifindex))
		return -1;
	if (rt->rt_src == 0) {
		ip_rt_put(rt);
		return -1;
	}
 
	skb=alloc_skb(IGMP_SIZE+dev->hard_header_len+15, GFP_ATOMIC);
	if (skb == NULL) {
		ip_rt_put(rt);
		return -1;
	}
 
	skb->dst = &rt->u.dst;
 
	skb_reserve(skb, (dev->hard_header_len+15)&~15);
 
	skb->nh.iph = iph = (struct iphdr *)skb_put(skb, sizeof(struct iphdr)+4);
 
	iph->version  = 4;
	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
	iph->tos      = 0xc0;
	iph->frag_off = htons(IP_DF);
	iph->ttl      = 1;
	iph->daddr    = dst;
	iph->saddr    = rt->rt_src;
	iph->protocol = IPPROTO_IGMP;
	iph->tot_len  = htons(IGMP_SIZE);
	ip_select_ident(iph, &rt->u.dst, NULL);
	((u8*)&iph[1])[0] = IPOPT_RA;
	((u8*)&iph[1])[1] = 4;
	((u8*)&iph[1])[2] = 0;
	((u8*)&iph[1])[3] = 0;
	ip_send_check(iph);
 
	ih = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
	ih->type=type;
	ih->code=0;
	ih->csum=0;
	ih->group=group;
	ih->csum=ip_compute_csum((void *)ih, sizeof(struct igmphdr));
 
	return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
		       output_maybe_reroute);
}
 
static void igmp_gq_timer_expire(unsigned long data)
{
	struct in_device *in_dev = (struct in_device *)data;
 
	in_dev->mr_gq_running = 0;
	igmpv3_send_report(in_dev, 0);
	__in_dev_put(in_dev);
}
 
static void igmp_ifc_timer_expire(unsigned long data)
{
	struct in_device *in_dev = (struct in_device *)data;
 
	igmpv3_send_cr(in_dev);
	if (in_dev->mr_ifc_count) {
		in_dev->mr_ifc_count--;
		igmp_ifc_start_timer(in_dev, IGMP_Unsolicited_Report_Interval);
	}
	__in_dev_put(in_dev);
}
 
static void igmp_ifc_event(struct in_device *in_dev)
{
	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
		return;
	in_dev->mr_ifc_count = in_dev->mr_qrv ? in_dev->mr_qrv : 
		IGMP_Unsolicited_Report_Count;
	igmp_ifc_start_timer(in_dev, 1);
}
 
 
static void igmp_timer_expire(unsigned long data)
{
	struct ip_mc_list *im=(struct ip_mc_list *)data;
	struct in_device *in_dev = im->interface;
 
	spin_lock(&im->lock);
	im->tm_running=0;
 
	if (im->unsolicit_count) {
		im->unsolicit_count--;
		igmp_start_timer(im, IGMP_Unsolicited_Report_Interval);
	}
	im->reporter = 1;
	spin_unlock(&im->lock);
 
	if (IGMP_V1_SEEN(in_dev))
		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
	else if (IGMP_V2_SEEN(in_dev))
		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
	else
		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
 
	ip_ma_put(im);
}
 
static void igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __u32 *srcs)
{
	struct ip_sf_list *psf;
	int i, scount;
 
	scount = 0;
	for (psf=pmc->sources; psf; psf=psf->sf_next) {
		if (scount == nsrcs)
			break;
		for (i=0; i<nsrcs; i++)
			if (srcs[i] == psf->sf_inaddr) {
				psf->sf_gsresp = 1;
				scount++;
				break;
			}
	}
}
 
static void igmp_heard_report(struct in_device *in_dev, u32 group)
{
	struct ip_mc_list *im;
 
	/* Timers are only set for non-local groups */
 
	if (group == IGMP_ALL_HOSTS)
		return;
 
	read_lock(&in_dev->lock);
	for (im=in_dev->mc_list; im!=NULL; im=im->next) {
		if (im->multiaddr == group) {
			igmp_stop_timer(im);
			break;
		}
	}
	read_unlock(&in_dev->lock);
}
 
static void igmp_heard_query(struct in_device *in_dev, struct igmphdr *ih,
	int len)
{
	struct igmpv3_query *ih3 = (struct igmpv3_query *)ih;
	struct ip_mc_list	*im;
	u32			group = ih->group;
	int			max_delay;
	int			mark = 0;
 
 
	if (len == 8) {
		if (ih->code == 0) {
			/* Alas, old v1 router presents here. */
 
			max_delay = IGMP_Query_Response_Interval;
			in_dev->mr_v1_seen = jiffies +
				IGMP_V1_Router_Present_Timeout;
			group = 0;
		} else {
			/* v2 router present */
			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
			in_dev->mr_v2_seen = jiffies +
				IGMP_V2_Router_Present_Timeout;
		}
		/* cancel the interface change timer */
		in_dev->mr_ifc_count = 0;
		if (del_timer(&in_dev->mr_ifc_timer))
			__in_dev_put(in_dev);
		/* clear deleted report items */
		igmpv3_clear_delrec(in_dev);
	} else if (len < 12) {
		return;	/* ignore bogus packet; freed by caller */
	} else { /* v3 */
		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
		if (!max_delay)
			max_delay = 1;	/* can't mod w/ 0 */
		in_dev->mr_maxdelay = max_delay;
		if (ih3->qrv)
			in_dev->mr_qrv = ih3->qrv;
		if (!group) { /* general query */
			if (ih3->nsrcs)
				return;	/* no sources allowed */
			igmp_gq_start_timer(in_dev);
			return;
		}
		/* mark sources to include, if group & source-specific */
		mark = ih3->nsrcs != 0;
	}
 
	/*
	 * - 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 a "local" group (224.0.0.X)
	 * - For timers already running check if they need to
	 *   be reset.
	 * - Use the igmp->igmp_code field as the maximum
	 *   delay possible
	 */
	read_lock(&in_dev->lock);
	for (im=in_dev->mc_list; im!=NULL; im=im->next) {
		if (group && group != im->multiaddr)
			continue;
		if (im->multiaddr == IGMP_ALL_HOSTS)
			continue;
		spin_lock_bh(&im->lock);
		if (im->tm_running)
			im->gsquery = im->gsquery && mark;
		else
			im->gsquery = mark;
		if (im->gsquery)
			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
		spin_unlock_bh(&im->lock);
		igmp_mod_timer(im, max_delay);
	}
	read_unlock(&in_dev->lock);
}
 
int igmp_rcv(struct sk_buff *skb)
{
	/* This basically follows the spec line by line -- see RFC1112 */
	struct igmphdr *ih = skb->h.igmph;
	struct in_device *in_dev = in_dev_get(skb->dev);
	int len = skb->len;
 
	if (in_dev==NULL) {
		kfree_skb(skb);
		return 0;
	}
 
	if (skb_is_nonlinear(skb)) {
		if (skb_linearize(skb, GFP_ATOMIC) != 0) {
			kfree_skb(skb);
			return -ENOMEM;
		}
		ih = skb->h.igmph;
	}
 
	if (len < sizeof(struct igmphdr) || ip_compute_csum((void *)ih, len)) {
		in_dev_put(in_dev);
		kfree_skb(skb);
		return 0;
	}
 
	switch (ih->type) {
	case IGMP_HOST_MEMBERSHIP_QUERY:
		igmp_heard_query(in_dev, ih, len);
		break;
	case IGMP_HOST_MEMBERSHIP_REPORT:
	case IGMPV2_HOST_MEMBERSHIP_REPORT:
	case IGMPV3_HOST_MEMBERSHIP_REPORT:
		/* Is it our report looped back? */
		if (((struct rtable*)skb->dst)->key.iif == 0)
			break;
		igmp_heard_report(in_dev, ih->group);
		break;
	case IGMP_PIM:
#ifdef CONFIG_IP_PIMSM_V1
		in_dev_put(in_dev);
		return pim_rcv_v1(skb);
#endif
	case IGMP_DVMRP:
	case IGMP_TRACE:
	case IGMP_HOST_LEAVE_MESSAGE:
	case IGMP_MTRACE:
	case IGMP_MTRACE_RESP:
		break;
	default:
		NETDEBUG(printk(KERN_DEBUG "New IGMP type=%d, why we do not know about it?\n", ih->type));
	}
	in_dev_put(in_dev);
	kfree_skb(skb);
	return 0;
}
 
#endif
 
 
/*
 *	Add a filter to a device
 */
 
static void ip_mc_filter_add(struct in_device *in_dev, u32 addr)
{
	char buf[MAX_ADDR_LEN];
	struct net_device *dev = in_dev->dev;
 
	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
	   We will get multicast token leakage, when IFF_MULTICAST
	   is changed. This check should be done in dev->set_multicast_list
	   routine. Something sort of:
	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
	   --ANK
	   */
	if (arp_mc_map(addr, buf, dev, 0) == 0)
		dev_mc_add(dev,buf,dev->addr_len,0);
}
 
/*
 *	Remove a filter from a device
 */
 
static void ip_mc_filter_del(struct in_device *in_dev, u32 addr)
{
	char buf[MAX_ADDR_LEN];
	struct net_device *dev = in_dev->dev;
 
	if (arp_mc_map(addr, buf, dev, 0) == 0)
		dev_mc_delete(dev,buf,dev->addr_len,0);
}
 
#ifdef CONFIG_IP_MULTICAST
/*
 * deleted ip_mc_list manipulation
 */
static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im)
{
	struct ip_mc_list *pmc;
 
	/* this is an "ip_mc_list" for convenience; only the fields below
	 * are actually used. In particular, the refcnt and users are not
	 * used for management of the delete list. Using the same structure
	 * for deleted items allows change reports to use common code with
	 * non-deleted or query-response MCA's.
	 */
	pmc = (struct ip_mc_list *)kmalloc(sizeof(*pmc), GFP_KERNEL);
	if (!pmc)
		return;
	memset(pmc, 0, sizeof(*pmc));
	spin_lock_bh(&im->lock);
	pmc->interface = im->interface;
	in_dev_hold(in_dev);
	pmc->multiaddr = im->multiaddr;
	pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
		IGMP_Unsolicited_Report_Count;
	pmc->sfmode = im->sfmode;
	if (pmc->sfmode == MCAST_INCLUDE) {
		struct ip_sf_list *psf;
 
		pmc->tomb = im->tomb;
		pmc->sources = im->sources;
		im->tomb = im->sources = 0;
		for (psf=pmc->sources; psf; psf=psf->sf_next)
			psf->sf_crcount = pmc->crcount;
	}
	spin_unlock_bh(&im->lock);
 
	write_lock_bh(&in_dev->mc_lock);
	pmc->next = in_dev->mc_tomb;
	in_dev->mc_tomb = pmc;
	write_unlock_bh(&in_dev->mc_lock);
}
 
static void igmpv3_del_delrec(struct in_device *in_dev, __u32 multiaddr)
{
	struct ip_mc_list *pmc, *pmc_prev;
	struct ip_sf_list *psf, *psf_next;
 
	write_lock_bh(&in_dev->mc_lock);
	pmc_prev = 0;
	for (pmc=in_dev->mc_tomb; pmc; pmc=pmc->next) {
		if (pmc->multiaddr == multiaddr)
			break;
		pmc_prev = pmc;
	}
	if (pmc) {
		if (pmc_prev)
			pmc_prev->next = pmc->next;
		else
			in_dev->mc_tomb = pmc->next;
	}
	write_unlock_bh(&in_dev->mc_lock);
	if (pmc) {
		for (psf=pmc->tomb; psf; psf=psf_next) {
			psf_next = psf->sf_next;
			kfree(psf);
		}
		in_dev_put(pmc->interface);
		kfree(pmc);
	}
}
 
static void igmpv3_clear_delrec(struct in_device *in_dev)
{
	struct ip_mc_list *pmc, *nextpmc;
 
	write_lock_bh(&in_dev->mc_lock);
	pmc = in_dev->mc_tomb;
	in_dev->mc_tomb = 0;
	write_unlock_bh(&in_dev->mc_lock);
 
	for (; pmc; pmc = nextpmc) {
		nextpmc = pmc->next;
		ip_mc_clear_src(pmc);
		in_dev_put(pmc->interface);
		kfree(pmc);
	}
	/* clear dead sources, too */
	read_lock(&in_dev->lock);
	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
		struct ip_sf_list *psf, *psf_next;
 
		spin_lock_bh(&pmc->lock);
		psf = pmc->tomb;
		pmc->tomb = 0;
		spin_unlock_bh(&pmc->lock);
		for (; psf; psf=psf_next) {
			psf_next = psf->sf_next;
			kfree(psf);
		}
	}
	read_unlock(&in_dev->lock);
}
#endif
 
static void igmp_group_dropped(struct ip_mc_list *im)
{
	struct in_device *in_dev = im->interface;
#ifdef CONFIG_IP_MULTICAST
	int reporter;
#endif
 
	if (im->loaded) {
		im->loaded = 0;
		ip_mc_filter_del(in_dev, im->multiaddr);
	}
 
#ifdef CONFIG_IP_MULTICAST
	if (im->multiaddr == IGMP_ALL_HOSTS)
		return;
 
	reporter = im->reporter;
	igmp_stop_timer(im);
 
	if (!in_dev->dead) {
		if (IGMP_V1_SEEN(in_dev))
			goto done;
		if (IGMP_V2_SEEN(in_dev)) {
			if (reporter)
				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
			goto done;
		}
		/* IGMPv3 */
		igmpv3_add_delrec(in_dev, im);
 
		igmp_ifc_event(in_dev);
	}
done:
#endif
	ip_mc_clear_src(im);
}
 
static void igmp_group_added(struct ip_mc_list *im)
{
	struct in_device *in_dev = im->interface;
 
	if (im->loaded == 0) {
		im->loaded = 1;
		ip_mc_filter_add(in_dev, im->multiaddr);
	}
 
#ifdef CONFIG_IP_MULTICAST
	if (im->multiaddr == IGMP_ALL_HOSTS)
		return;
 
	if (in_dev->dead)
		return;
	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
		spin_lock_bh(&im->lock);
		igmp_start_timer(im, IGMP_Initial_Report_Delay);
		spin_unlock_bh(&im->lock);
		return;
	}
	/* else, v3 */
 
	im->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
		IGMP_Unsolicited_Report_Count;
	igmp_ifc_event(in_dev);
#endif
}
 
 
/*
 *	Multicast list managers
 */
 
 
/*
 *	A socket has joined a multicast group on device dev.
 */
 
void ip_mc_inc_group(struct in_device *in_dev, u32 addr)
{
	struct ip_mc_list *im;
 
	ASSERT_RTNL();
 
	for (im=in_dev->mc_list; im; im=im->next) {
		if (im->multiaddr == addr) {
			im->users++;
			ip_mc_add_src(in_dev, &addr, MCAST_EXCLUDE, 0, 0, 0);
			goto out;
		}
	}
 
	im = (struct ip_mc_list *)kmalloc(sizeof(*im), GFP_KERNEL);
	if (!im)
		goto out;
 
	im->users=1;
	im->interface=in_dev;
	in_dev_hold(in_dev);
	im->multiaddr=addr;
	/* initial mode is (EX, empty) */
	im->sfmode = MCAST_EXCLUDE;
	im->sfcount[MCAST_INCLUDE] = 0;
	im->sfcount[MCAST_EXCLUDE] = 1;
	im->sources = 0;
	im->tomb = 0;
	im->crcount = 0;
	atomic_set(&im->refcnt, 1);
	spin_lock_init(&im->lock);
#ifdef CONFIG_IP_MULTICAST
	im->tm_running=0;
	init_timer(&im->timer);
	im->timer.data=(unsigned long)im;
	im->timer.function=&igmp_timer_expire;
	im->unsolicit_count = IGMP_Unsolicited_Report_Count;
	im->reporter = 0;
	im->gsquery = 0;
#endif
	im->loaded = 0;
	write_lock_bh(&in_dev->lock);
	im->next=in_dev->mc_list;
	in_dev->mc_list=im;
	write_unlock_bh(&in_dev->lock);
#ifdef CONFIG_IP_MULTICAST
	igmpv3_del_delrec(in_dev, im->multiaddr);
#endif
	igmp_group_added(im);
	if (!in_dev->dead)
		ip_rt_multicast_event(in_dev);
out:
	return;
}
 
/*
 *	A socket has left a multicast group on device dev
 */
 
void ip_mc_dec_group(struct in_device *in_dev, u32 addr)
{
	struct ip_mc_list *i, **ip;
 
	ASSERT_RTNL();
 
	for (ip=&in_dev->mc_list; (i=*ip)!=NULL; ip=&i->next) {
		if (i->multiaddr==addr) {
			if (--i->users == 0) {
				write_lock_bh(&in_dev->lock);
				*ip = i->next;
				write_unlock_bh(&in_dev->lock);
				igmp_group_dropped(i);
 
				if (!in_dev->dead)
					ip_rt_multicast_event(in_dev);
 
				ip_ma_put(i);
				return;
			}
			break;
		}
	}
}
 
/* Device going down */
 
void ip_mc_down(struct in_device *in_dev)
{
	struct ip_mc_list *i;
 
	ASSERT_RTNL();
 
	for (i=in_dev->mc_list; i; i=i->next)
		igmp_group_dropped(i);
 
#ifdef CONFIG_IP_MULTICAST
	in_dev->mr_ifc_count = 0;
	if (del_timer(&in_dev->mr_ifc_timer))
		__in_dev_put(in_dev);
	in_dev->mr_gq_running = 0;
	if (del_timer(&in_dev->mr_gq_timer))
		__in_dev_put(in_dev);
	igmpv3_clear_delrec(in_dev);
#endif
 
	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
}
 
void ip_mc_init_dev(struct in_device *in_dev)
{
	ASSERT_RTNL();
 
	in_dev->mc_tomb = 0;
#ifdef CONFIG_IP_MULTICAST
	in_dev->mr_gq_running = 0;
	init_timer(&in_dev->mr_gq_timer);
	in_dev->mr_gq_timer.data=(unsigned long) in_dev;
	in_dev->mr_gq_timer.function=&igmp_gq_timer_expire;
	in_dev->mr_ifc_count = 0;
	init_timer(&in_dev->mr_ifc_timer);
	in_dev->mr_ifc_timer.data=(unsigned long) in_dev;
	in_dev->mr_ifc_timer.function=&igmp_ifc_timer_expire;
	in_dev->mr_qrv = IGMP_Unsolicited_Report_Count;
#endif
 
	in_dev->mc_lock = RW_LOCK_UNLOCKED;
}
 
/* Device going up */
 
void ip_mc_up(struct in_device *in_dev)
{
	struct ip_mc_list *i;
 
	ASSERT_RTNL();
 
	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
 
	for (i=in_dev->mc_list; i; i=i->next)
		igmp_group_added(i);
}
 
/*
 *	Device is about to be destroyed: clean up.
 */
 
void ip_mc_destroy_dev(struct in_device *in_dev)
{
	struct ip_mc_list *i;
 
	ASSERT_RTNL();
 
	/* Deactivate timers */
	ip_mc_down(in_dev);
 
	write_lock_bh(&in_dev->lock);
	while ((i = in_dev->mc_list) != NULL) {
		in_dev->mc_list = i->next;
		write_unlock_bh(&in_dev->lock);
 
		igmp_group_dropped(i);
		ip_ma_put(i);
 
		write_lock_bh(&in_dev->lock);
	}
	write_unlock_bh(&in_dev->lock);
}
 
static struct in_device * ip_mc_find_dev(struct ip_mreqn *imr)
{
	struct rtable *rt;
	struct net_device *dev = NULL;
	struct in_device *idev = NULL;
 
	if (imr->imr_ifindex) {
		idev = inetdev_by_index(imr->imr_ifindex);
		if (idev)
			__in_dev_put(idev);
		return idev;
	}
	if (imr->imr_address.s_addr) {
		dev = ip_dev_find(imr->imr_address.s_addr);
		if (!dev)
			return NULL;
		__dev_put(dev);
	}
 
	if (!dev && !ip_route_output(&rt, imr->imr_multiaddr.s_addr, 0, 0, 0)) {
		dev = rt->u.dst.dev;
		ip_rt_put(rt);
	}
	if (dev) {
		imr->imr_ifindex = dev->ifindex;
		idev = __in_dev_get(dev);
	}
	return idev;
}
 
/*
 *	Join a socket to a group
 */
int sysctl_igmp_max_memberships = IP_MAX_MEMBERSHIPS;
int sysctl_igmp_max_msf = IP_MAX_MSF;
 
 
static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
	__u32 *psfsrc)
{
	struct ip_sf_list *psf, *psf_prev;
	int rv = 0;
 
	psf_prev = 0;
	for (psf=pmc->sources; psf; psf=psf->sf_next) {
		if (psf->sf_inaddr == *psfsrc)
			break;
		psf_prev = psf;
	}
	if (!psf || psf->sf_count[sfmode] == 0) {
		/* source filter not found, or count wrong =>  bug */
		return -ESRCH;
	}
	psf->sf_count[sfmode]--;
	if (psf->sf_count[sfmode] == 0) {
		ip_rt_multicast_event(pmc->interface);
	}
	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
#ifdef CONFIG_IP_MULTICAST
		struct in_device *in_dev = pmc->interface;
#endif
 
		/* no more filters for this source */
		if (psf_prev)
			psf_prev->sf_next = psf->sf_next;
		else
			pmc->sources = psf->sf_next;
#ifdef CONFIG_IP_MULTICAST
		if (psf->sf_oldin &&
		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
			psf->sf_crcount = in_dev->mr_qrv ? in_dev->mr_qrv : 
				IGMP_Unsolicited_Report_Count;
			psf->sf_next = pmc->tomb;
			pmc->tomb = psf;
			rv = 1;
		} else
#endif
			kfree(psf);
	}
	return rv;
}
 
int ip_mc_del_src(struct in_device *in_dev, __u32 *pmca, int sfmode,
	int sfcount, __u32 *psfsrc, int delta)
{
	struct ip_mc_list *pmc;
	int	changerec = 0;
	int	i, err;
 
	if (!in_dev)
		return -ENODEV;
	read_lock(&in_dev->lock);
	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
		if (*pmca == pmc->multiaddr)
			break;
	}
	if (!pmc) {
		/* MCA not found?? bug */
		read_unlock(&in_dev->lock);
		return -ESRCH;
	}
	spin_lock_bh(&pmc->lock);
	read_unlock(&in_dev->lock);
#ifdef CONFIG_IP_MULTICAST
	sf_markstate(pmc);
#endif
	if (!delta) {
		err = -EINVAL;
		if (!pmc->sfcount[sfmode])
			goto out_unlock;
		pmc->sfcount[sfmode]--;
	}
	err = 0;
	for (i=0; i<sfcount; i++) {
		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
 
		changerec |= rv > 0;
		if (!err && rv < 0)
			err = rv;
	}
	if (pmc->sfmode == MCAST_EXCLUDE &&
	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
	    pmc->sfcount[MCAST_INCLUDE]) {
#ifdef CONFIG_IP_MULTICAST
		struct ip_sf_list *psf;
#endif
 
		/* filter mode change */
		pmc->sfmode = MCAST_INCLUDE;
#ifdef CONFIG_IP_MULTICAST
		pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv : 
			IGMP_Unsolicited_Report_Count;
		in_dev->mr_ifc_count = pmc->crcount;
		for (psf=pmc->sources; psf; psf = psf->sf_next)
			psf->sf_crcount = 0;
		igmp_ifc_event(pmc->interface);
	} else if (sf_setstate(pmc) || changerec) {
		igmp_ifc_event(pmc->interface);
#endif
	}
out_unlock:
	spin_unlock_bh(&pmc->lock);
	return err;
}
 
/*
 * Add multicast single-source filter to the interface list
 */
static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
	__u32 *psfsrc, int delta)
{
	struct ip_sf_list *psf, *psf_prev;
 
	psf_prev = 0;
	for (psf=pmc->sources; psf; psf=psf->sf_next) {
		if (psf->sf_inaddr == *psfsrc)
			break;
		psf_prev = psf;
	}
	if (!psf) {
		psf = (struct ip_sf_list *)kmalloc(sizeof(*psf), GFP_ATOMIC);
		if (!psf)
			return -ENOBUFS;
		memset(psf, 0, sizeof(*psf));
		psf->sf_inaddr = *psfsrc;
		if (psf_prev) {
			psf_prev->sf_next = psf;
		} else
			pmc->sources = psf;
	}
	psf->sf_count[sfmode]++;
	if (psf->sf_count[sfmode] == 1) {
		ip_rt_multicast_event(pmc->interface);
	}
	return 0;
}
 
#ifdef CONFIG_IP_MULTICAST
static void sf_markstate(struct ip_mc_list *pmc)
{
	struct ip_sf_list *psf;
	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
 
	for (psf=pmc->sources; psf; psf=psf->sf_next)
		if (pmc->sfcount[MCAST_EXCLUDE]) {
			psf->sf_oldin = mca_xcount ==
				psf->sf_count[MCAST_EXCLUDE] &&
				!psf->sf_count[MCAST_INCLUDE];
		} else
			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
}
 
static int sf_setstate(struct ip_mc_list *pmc)
{
	struct ip_sf_list *psf;
	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
	int qrv = pmc->interface->mr_qrv;
	int new_in, rv;
 
	rv = 0;
	for (psf=pmc->sources; psf; psf=psf->sf_next) {
		if (pmc->sfcount[MCAST_EXCLUDE]) {
			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
				!psf->sf_count[MCAST_INCLUDE];
		} else
			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
		if (new_in != psf->sf_oldin) {
			psf->sf_crcount = qrv;
			rv++;
		}
	}
	return rv;
}
#endif
 
/*
 * Add multicast source filter list to the interface list
 */
int ip_mc_add_src(struct in_device *in_dev, __u32 *pmca, int sfmode,
	int sfcount, __u32 *psfsrc, int delta)
{
	struct ip_mc_list *pmc;
	int	isexclude;
	int	i, err;
 
	if (!in_dev)
		return -ENODEV;
	read_lock(&in_dev->lock);
	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
		if (*pmca == pmc->multiaddr)
			break;
	}
	if (!pmc) {
		/* MCA not found?? bug */
		read_unlock(&in_dev->lock);
		return -ESRCH;
	}
	spin_lock_bh(&pmc->lock);
	read_unlock(&in_dev->lock);
 
#ifdef CONFIG_IP_MULTICAST
	sf_markstate(pmc);
#endif
	isexclude = pmc->sfmode == MCAST_EXCLUDE;
	if (!delta)
		pmc->sfcount[sfmode]++;
	err = 0;
	for (i=0; i<sfcount; i++) {
		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i], delta);
		if (err)
			break;
	}
	if (err) {
		int j;
 
		pmc->sfcount[sfmode]--;
		for (j=0; j<i; j++)
			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
#ifdef CONFIG_IP_MULTICAST
		struct in_device *in_dev = pmc->interface;
		struct ip_sf_list *psf;
#endif
 
		/* filter mode change */
		if (pmc->sfcount[MCAST_EXCLUDE])
			pmc->sfmode = MCAST_EXCLUDE;
		else if (pmc->sfcount[MCAST_INCLUDE])
			pmc->sfmode = MCAST_INCLUDE;
#ifdef CONFIG_IP_MULTICAST
		/* else no filters; keep old mode for reports */
 
		pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv : 
			IGMP_Unsolicited_Report_Count;
		in_dev->mr_ifc_count = pmc->crcount;
		for (psf=pmc->sources; psf; psf = psf->sf_next)
			psf->sf_crcount = 0;
		igmp_ifc_event(in_dev);
	} else if (sf_setstate(pmc)) {
		igmp_ifc_event(in_dev);
#endif
	}
	spin_unlock_bh(&pmc->lock);
	return err;
}
 
static void ip_mc_clear_src(struct ip_mc_list *pmc)
{
	struct ip_sf_list *psf, *nextpsf;
 
	for (psf=pmc->tomb; psf; psf=nextpsf) {
		nextpsf = psf->sf_next;
		kfree(psf);
	}
	pmc->tomb = 0;
	for (psf=pmc->sources; psf; psf=nextpsf) {
		nextpsf = psf->sf_next;
		kfree(psf);
	}
	pmc->sources = 0;
	pmc->sfmode = MCAST_EXCLUDE;
	pmc->sfcount[MCAST_EXCLUDE] = 0;
	pmc->sfcount[MCAST_EXCLUDE] = 1;
}
 
 
/*
 * Join a multicast group
 */
int ip_mc_join_group(struct sock *sk , struct ip_mreqn *imr)
{
	int err;
	u32 addr = imr->imr_multiaddr.s_addr;
	struct ip_mc_socklist *iml, *i;
	struct in_device *in_dev;
	struct inet_opt *inet = &sk->protinfo.af_inet;
	int count = 0;
 
	if (!MULTICAST(addr))
		return -EINVAL;
 
	rtnl_shlock();
 
	in_dev = ip_mc_find_dev(imr);
 
	if (!in_dev) {
		iml = NULL;
		err = -ENODEV;
		goto done;
	}
 
	iml = (struct ip_mc_socklist *)sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
 
	err = -EADDRINUSE;
	for (i = inet->mc_list; i; i = i->next) {
		if (memcmp(&i->multi, imr, sizeof(*imr)) == 0) {
			/* New style additions are reference counted */
			if (imr->imr_address.s_addr == 0) {
				i->count++;
				err = 0;
			}
			goto done;
		}
		count++;
	}
	err = -ENOBUFS;
	if (iml == NULL || count >= sysctl_igmp_max_memberships)
		goto done;
	memcpy(&iml->multi, imr, sizeof(*imr));
	iml->next = sk->protinfo.af_inet.mc_list;
	iml->count = 1;
	iml->sflist = NULL;
	iml->sfmode = MCAST_EXCLUDE;
	inet->mc_list = iml;
	ip_mc_inc_group(in_dev, addr);
	iml = NULL;
	err = 0;
 
done:
	rtnl_shunlock();
	if (iml)
		sock_kfree_s(sk, iml, sizeof(*iml));
	return err;
}
 
int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
	struct in_device *in_dev)
{
	int err;
 
	if (iml->sflist == 0) {
		/* any-source empty exclude case */
		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
			iml->sfmode, 0, 0, 0);
	}
	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
			iml->sfmode, iml->sflist->sl_count,
			iml->sflist->sl_addr, 0);
	sock_kfree_s(sk, iml->sflist, IP_SFLSIZE(iml->sflist->sl_max));
	iml->sflist = 0;
	return err;
}
 
/*
 *	Ask a socket to leave a group.
 */
 
int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
{
	struct inet_opt *inet = &sk->protinfo.af_inet;
	struct ip_mc_socklist *iml, **imlp;
 
	rtnl_lock();
	for (imlp = &inet->mc_list; (iml = *imlp) != NULL; imlp = &iml->next) {
		if (iml->multi.imr_multiaddr.s_addr==imr->imr_multiaddr.s_addr &&
		    iml->multi.imr_address.s_addr==imr->imr_address.s_addr &&
		    (!imr->imr_ifindex || iml->multi.imr_ifindex==imr->imr_ifindex)) {
			struct in_device *in_dev;
 
			in_dev = inetdev_by_index(iml->multi.imr_ifindex);
			if (in_dev)
				(void) ip_mc_leave_src(sk, iml, in_dev);
			if (--iml->count) {
				rtnl_unlock();
				if (in_dev)
					in_dev_put(in_dev);
				return 0;
			}
 
			*imlp = iml->next;
 
			if (in_dev) {
				ip_mc_dec_group(in_dev, imr->imr_multiaddr.s_addr);
				in_dev_put(in_dev);
			}
			rtnl_unlock();
			sock_kfree_s(sk, iml, sizeof(*iml));
			return 0;
		}
	}
	rtnl_unlock();
	return -EADDRNOTAVAIL;
}
 
int ip_mc_source(int add, int omode, struct sock *sk, struct
	ip_mreq_source *mreqs, int ifindex)
{
	int err;
	struct ip_mreqn imr;
	u32 addr = mreqs->imr_multiaddr;
	struct ip_mc_socklist *pmc;
	struct in_device *in_dev = 0;
	struct inet_opt *inet = &sk->protinfo.af_inet;
	struct ip_sf_socklist *psl;
	int i, j, rv;
 
	if (!MULTICAST(addr))
		return -EINVAL;
 
	rtnl_shlock();
 
	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
	imr.imr_address.s_addr = mreqs->imr_interface;
	imr.imr_ifindex = ifindex;
	in_dev = ip_mc_find_dev(&imr);
 
	if (!in_dev) {
		err = -ENODEV;
		goto done;
	}
	err = -EADDRNOTAVAIL;
 
	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
		if (memcmp(&pmc->multi, mreqs, 2*sizeof(__u32)) == 0)
			break;
	}
	if (!pmc)		/* must have a prior join */
		goto done;
	/* if a source filter was set, must be the same mode as before */
	if (pmc->sflist) {
		if (pmc->sfmode != omode)
			goto done;
	} else if (pmc->sfmode != omode) {
		/* allow mode switches for empty-set filters */
		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, 0, 0);
		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0, 
			0, 0);
		pmc->sfmode = omode;
	}
 
	psl = pmc->sflist;
	if (!add) {
		if (!psl)
			goto done;
		rv = !0;
		for (i=0; i<psl->sl_count; i++) {
			rv = memcmp(&psl->sl_addr, &mreqs->imr_multiaddr,
				sizeof(__u32));
			if (rv >= 0)
				break;
		}
		if (!rv)	/* source not found */
			goto done;
 
		/* update the interface filter */
		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1, 
			&mreqs->imr_sourceaddr, 1);
 
		for (j=i+1; j<psl->sl_count; j++)
			psl->sl_addr[j-1] = psl->sl_addr[j];
		psl->sl_count--;
		err = 0;
		goto done;
	}
	/* else, add a new source to the filter */
 
	if (psl && psl->sl_count >= sysctl_igmp_max_msf) {
		err = -ENOBUFS;
		goto done;
	}
	if (!psl || psl->sl_count == psl->sl_max) {
		struct ip_sf_socklist *newpsl;
		int count = IP_SFBLOCK;
 
		if (psl)
			count += psl->sl_max;
		newpsl = (struct ip_sf_socklist *)sock_kmalloc(sk,
			IP_SFLSIZE(count), GFP_KERNEL);
		if (!newpsl) {
			err = -ENOBUFS;
			goto done;
		}
		newpsl->sl_max = count;
		newpsl->sl_count = count - IP_SFBLOCK;
		if (psl) {
			for (i=0; i<psl->sl_count; i++)
				newpsl->sl_addr[i] = psl->sl_addr[i];
			sock_kfree_s(sk, psl, IP_SFLSIZE(psl->sl_max));
		}
		pmc->sflist = psl = newpsl;
	}
	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
	for (i=0; i<psl->sl_count; i++) {
		rv = memcmp(&psl->sl_addr, &mreqs->imr_multiaddr,
			sizeof(__u32));
		if (rv >= 0)
			break;
	}
	if (rv == 0)		/* address already there is an error */
		goto done;
	for (j=psl->sl_count-1; j>=i; j--)
		psl->sl_addr[j+1] = psl->sl_addr[j];
	psl->sl_addr[i] = mreqs->imr_sourceaddr;
	psl->sl_count++;
	err = 0;
	/* update the interface list */
	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1, 
		&mreqs->imr_sourceaddr, 1);
done:
	rtnl_shunlock();
	return err;
}
 
int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
{
	int err;
	struct ip_mreqn	imr;
	u32 addr = msf->imsf_multiaddr;
	struct ip_mc_socklist *pmc;
	struct in_device *in_dev;
	struct inet_opt *inet = &sk->protinfo.af_inet;
	struct ip_sf_socklist *newpsl, *psl;
 
	if (!MULTICAST(addr))
		return -EINVAL;
	if (msf->imsf_fmode != MCAST_INCLUDE &&
	    msf->imsf_fmode != MCAST_EXCLUDE)
		return -EINVAL;
 
	rtnl_shlock();
 
	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
	imr.imr_address.s_addr = msf->imsf_interface;
	imr.imr_ifindex = ifindex;
	in_dev = ip_mc_find_dev(&imr);
 
	if (!in_dev) {
		err = -ENODEV;
		goto done;
	}
	err = -EADDRNOTAVAIL;
 
	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
		    pmc->multi.imr_ifindex == imr.imr_ifindex)
			break;
	}
	if (!pmc)		/* must have a prior join */
		goto done;
	if (msf->imsf_numsrc) {
		newpsl = (struct ip_sf_socklist *)sock_kmalloc(sk,
				IP_SFLSIZE(msf->imsf_numsrc), GFP_KERNEL);
		if (!newpsl) {
			err = -ENOBUFS;
			goto done;
		}
		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
		memcpy(newpsl->sl_addr, msf->imsf_slist,
			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
		if (err) {
			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
			goto done;
		}
	} else
		newpsl = 0;
	psl = pmc->sflist;
	if (psl) {
		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
			psl->sl_count, psl->sl_addr, 0);
		sock_kfree_s(sk, psl, IP_SFLSIZE(psl->sl_max));
	} else
		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
			0, 0, 0);
	pmc->sflist = newpsl;
	pmc->sfmode = msf->imsf_fmode;
done:
	rtnl_shunlock();
	return err;
}
 
int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
	struct ip_msfilter *optval, int *optlen)
{
	int err, len, count, copycount;
	struct ip_mreqn	imr;
	u32 addr = msf->imsf_multiaddr;
	struct ip_mc_socklist *pmc;
	struct in_device *in_dev;
	struct inet_opt *inet = &sk->protinfo.af_inet;
	struct ip_sf_socklist *psl;
 
	if (!MULTICAST(addr))
		return -EINVAL;
 
	rtnl_shlock();
 
	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
	imr.imr_address.s_addr = msf->imsf_interface;
	imr.imr_ifindex = 0;
	in_dev = ip_mc_find_dev(&imr);
 
	if (!in_dev) {
		err = -ENODEV;
		goto done;
	}
	err = -EADDRNOTAVAIL;
 
	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
		    pmc->multi.imr_ifindex == imr.imr_ifindex)
			break;
	}
	if (!pmc)		/* must have a prior join */
		goto done;
	msf->imsf_fmode = pmc->sfmode;
	psl = pmc->sflist;
	rtnl_shunlock();
	if (!psl) {
		len = 0;
		count = 0;
	} else {
		count = psl->sl_count;
	}
	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
	len = copycount * sizeof(psl->sl_addr[0]);
	msf->imsf_numsrc = count;
	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
	    copy_to_user((void *)optval, msf, IP_MSFILTER_SIZE(0))) {
		return -EFAULT;
	}
	if (len &&
	    copy_to_user((void *)&optval->imsf_slist[0], psl->sl_addr, len))
		return -EFAULT;
	return 0;
done:
	rtnl_shunlock();
	return err;
}
 
int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
	struct group_filter *optval, int *optlen)
{
	int err, i, count, copycount;
	struct sockaddr_in *psin;
	u32 addr;
	struct ip_mc_socklist *pmc;
	struct inet_opt *inet = &sk->protinfo.af_inet;
	struct ip_sf_socklist *psl;
 
	psin = (struct sockaddr_in *)&gsf->gf_group;
	if (psin->sin_family != AF_INET)
		return -EINVAL;
	addr = psin->sin_addr.s_addr;
	if (!MULTICAST(addr))
		return -EINVAL;
 
	rtnl_shlock();
 
	err = -EADDRNOTAVAIL;
 
	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
		if (pmc->multi.imr_multiaddr.s_addr == addr &&
		    pmc->multi.imr_ifindex == gsf->gf_interface)
			break;
	}
	if (!pmc)		/* must have a prior join */
		goto done;
	gsf->gf_fmode = pmc->sfmode;
	psl = pmc->sflist;
	rtnl_shunlock();
	count = psl ? psl->sl_count : 0;
	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
	gsf->gf_numsrc = count;
	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
	    copy_to_user((void *)optval, gsf, GROUP_FILTER_SIZE(0))) {
		return -EFAULT;
	}
	for (i=0; i<copycount; i++) {
		struct sockaddr_in *psin;
		struct sockaddr_storage ss;
 
		psin = (struct sockaddr_in *)&ss;
		memset(&ss, 0, sizeof(ss));
		psin->sin_family = AF_INET;
		psin->sin_addr.s_addr = psl->sl_addr[i];
		if (copy_to_user((void *)&optval->gf_slist[i], &ss, sizeof(ss)))
			return -EFAULT;
	}
	return 0;
done:
	rtnl_shunlock();
	return err;
}
 
/*
 * check if a multicast source filter allows delivery for a given <src,dst,intf>
 */
int ip_mc_sf_allow(struct sock *sk, u32 loc_addr, u32 rmt_addr, int dif)
{
	struct inet_opt *inet = &sk->protinfo.af_inet;
	struct ip_mc_socklist *pmc;
	struct ip_sf_socklist *psl;
	int i;
 
	if (!MULTICAST(loc_addr))
		return 1;
 
	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
		    pmc->multi.imr_ifindex == dif)
			break;
	}
	if (!pmc)
		return 1;
	psl = pmc->sflist;
	if (!psl)
		return pmc->sfmode == MCAST_EXCLUDE;
 
	for (i=0; i<psl->sl_count; i++) {
		if (psl->sl_addr[i] == rmt_addr)
			break;
	}
	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
		return 0;
	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
		return 0;
	return 1;
}
 
/*
 *	A socket is closing.
 */
 
void ip_mc_drop_socket(struct sock *sk)
{
	struct inet_opt *inet = &sk->protinfo.af_inet;
	struct ip_mc_socklist *iml;
 
	if (inet->mc_list == NULL)
		return;
 
	rtnl_lock();
	while ((iml = inet->mc_list) != NULL) {
		struct in_device *in_dev;
		inet->mc_list = iml->next;
 
		if ((in_dev = inetdev_by_index(iml->multi.imr_ifindex)) != NULL) {
			(void) ip_mc_leave_src(sk, iml, in_dev);
			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
			in_dev_put(in_dev);
		}
		sock_kfree_s(sk, iml, sizeof(*iml));
 
	}
	rtnl_unlock();
}
 
int ip_check_mc(struct in_device *in_dev, u32 mc_addr, u32 src_addr)
{
	struct ip_mc_list *im;
	struct ip_sf_list *psf;
	int rv = 0;
 
	read_lock(&in_dev->lock);
	for (im=in_dev->mc_list; im; im=im->next) {
		if (im->multiaddr == mc_addr)
			break;
	}
	/*
	 * This should check the protocol and allow all IGMP packets
	 * here, but it isn't available in the call from ip_route_output()
	 * in 2.4.x. It shouldn't actually matter, since groups joined
	 * from within the kernel will have an {exclude, empty} filter.
	 * Differs from 2.5.x here.	+-DLS 4/23/03
	 */
	if (im) {
		if (src_addr) {
			for (psf=im->sources; psf; psf=psf->sf_next) {
				if (psf->sf_inaddr == src_addr)
					break;
			}
			if (psf)
				rv = psf->sf_count[MCAST_INCLUDE] ||
					psf->sf_count[MCAST_EXCLUDE] !=
					im->sfcount[MCAST_EXCLUDE];
			else
				rv = im->sfcount[MCAST_EXCLUDE] != 0;
		} else
			rv = 1;
	}
	read_unlock(&in_dev->lock);
	return rv;
}
 
 
int ip_mc_procinfo(char *buffer, char **start, off_t offset, int length)
{
	off_t pos=0, begin=0;
	struct ip_mc_list *im;
	int len=0;
	struct net_device *dev;
 
	len=sprintf(buffer,"Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");  
 
	read_lock(&dev_base_lock);
	for(dev = dev_base; dev; dev = dev->next) {
		struct in_device *in_dev = in_dev_get(dev);
		char   *querier = "NONE";
 
		if (in_dev == NULL)
			continue;
 
#ifdef CONFIG_IP_MULTICAST
		querier = IGMP_V1_SEEN(in_dev) ? "V1" : "V2";
#endif
 
		len+=sprintf(buffer+len,"%d\t%-10s: %5d %7s\n",
			     dev->ifindex, dev->name, dev->mc_count, querier);
 
		read_lock(&in_dev->lock);
		for (im = in_dev->mc_list; im; im = im->next) {
			len+=sprintf(buffer+len,
				     "\t\t\t\t%08lX %5d %d:%08lX\t\t%d\n",
				     im->multiaddr, im->users,
				     im->tm_running, im->timer.expires-jiffies, im->reporter);
 
			pos=begin+len;
			if(pos<offset)
			{
				len=0;
				begin=pos;
			}
			if(pos>offset+length) {
				read_unlock(&in_dev->lock);
				in_dev_put(in_dev);
				goto done;
			}
		}
		read_unlock(&in_dev->lock);
		in_dev_put(in_dev);
	}
done:
	read_unlock(&dev_base_lock);
 
	*start=buffer+(offset-begin);
	len-=(offset-begin);
	if(len>length)
		len=length;
	if(len<0)
		len=0;
	return len;
}
 
int ip_mcf_procinfo(char *buffer, char **start, off_t offset, int length)
{
	off_t pos=0, begin=0;
	int len=0;
	int first = 1;
	struct net_device *dev;
 
	read_lock(&dev_base_lock);
	for(dev=dev_base; dev; dev=dev->next) {
		struct in_device *in_dev = in_dev_get(dev);
		struct ip_mc_list *imc;
 
		if (in_dev == NULL)
			continue;
 
		read_lock(&in_dev->lock);
 
		for (imc=in_dev->mc_list; imc; imc=imc->next) {
			struct ip_sf_list *psf;
 
			spin_lock_bh(&imc->lock);
			for (psf=imc->sources; psf; psf=psf->sf_next) {
				if (first) {
					len += sprintf(buffer+len, "%3s %6s "
						"%10s %10s %6s %6s\n", "Idx",
						"Device", "MCA", "SRC", "INC",
						"EXC");
					first = 0;
				}
				len += sprintf(buffer+len, "%3d %6.6s 0x%08x "
					"0x%08x %6lu %6lu\n", dev->ifindex,
					dev->name, ntohl(imc->multiaddr),
					ntohl(psf->sf_inaddr),
					psf->sf_count[MCAST_INCLUDE],
					psf->sf_count[MCAST_EXCLUDE]);
				pos=begin+len;
				if(pos<offset)
				{
					len=0;
					begin=pos;
				}
				if(pos>offset+length) {
					spin_unlock_bh(&imc->lock);
					read_unlock(&in_dev->lock);
					in_dev_put(in_dev);
					goto done;
				}
			}
			spin_unlock_bh(&imc->lock);
		}
		read_unlock(&in_dev->lock);
		in_dev_put(in_dev);
	}
done:
	read_unlock(&dev_base_lock);
 
	*start=buffer+(offset-begin);
	len-=(offset-begin);
	if(len>length)
		len=length;
	if(len<0)
		len=0;
	return len;
}