igmp.c

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	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);
}

static void igmp_group_dropped(struct ip_mc_list *im)
{
#ifdef CONFIG_IP_MULTICAST
	int reporter;
#endif

	if (im->loaded) {
		im->loaded = 0;
		ip_mc_filter_del(im->interface, im->multiaddr);
	}

#ifdef CONFIG_IP_MULTICAST
	if (im->multiaddr == IGMP_ALL_HOSTS)
		return;

	reporter = im->reporter;
	igmp_stop_timer(im);

	if (reporter && !IGMP_V1_SEEN(im->interface))
		igmp_send_report(im->interface->dev, im->multiaddr, IGMP_HOST_LEAVE_MESSAGE);
#endif
}

static void igmp_group_added(struct ip_mc_list *im)
{
	if (im->loaded == 0) {
		im->loaded = 1;
		ip_mc_filter_add(im->interface, im->multiaddr);
	}

#ifdef CONFIG_IP_MULTICAST
	if (im->multiaddr == IGMP_ALL_HOSTS)
		return;

	spin_lock_bh(&im->lock);
	igmp_start_timer(im, IGMP_Initial_Report_Delay);
	spin_unlock_bh(&im->lock);
#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++;
			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;
	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;
#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);
	igmp_group_added(im);
	if (in_dev->dev->flags & IFF_UP)
		ip_rt_multicast_event(in_dev);
out:
	return;
}

/*
 *	A socket has left a multicast group on device dev
 */

int ip_mc_dec_group(struct in_device *in_dev, u32 addr)
{
	int err = -ESRCH;
	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->dev->flags & IFF_UP)
					ip_rt_multicast_event(in_dev);

				ip_ma_put(i);
				return 0;
			}
			err = 0;
			break;
		}
	}
	return -ESRCH;
}

/* 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);

	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
}

/* 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();

	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_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 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;
	int count = 0;

	if (!MULTICAST(addr))
		return -EINVAL;

	rtnl_shlock();

	if (!imr->imr_ifindex)
		in_dev = ip_mc_find_dev(imr);
	else {
		in_dev = inetdev_by_index(imr->imr_ifindex);
		if (in_dev)
			__in_dev_put(in_dev);
	}

	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=sk->protinfo.af_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;
	sk->protinfo.af_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;
}

/*
 *	Ask a socket to leave a group.
 */

int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
{
	struct ip_mc_socklist *iml, **imlp;

	rtnl_lock();
	for (imlp=&sk->protinfo.af_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;
			if (--iml->count) {
				rtnl_unlock();
				return 0;
			}

			*imlp = iml->next;

			in_dev = inetdev_by_index(iml->multi.imr_ifindex);
			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;
}

/*
 *	A socket is closing.
 */

void ip_mc_drop_socket(struct sock *sk)
{
	struct ip_mc_socklist *iml;

	if (sk->protinfo.af_inet.mc_list == NULL)
		return;

	rtnl_lock();
	while ((iml=sk->protinfo.af_inet.mc_list) != NULL) {
		struct in_device *in_dev;
		sk->protinfo.af_inet.mc_list = iml->next;

		if ((in_dev = inetdev_by_index(iml->multi.imr_ifindex)) != NULL) {
			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)
{
	struct ip_mc_list *im;

	read_lock(&in_dev->lock);
	for (im=in_dev->mc_list; im; im=im->next) {
		if (im->multiaddr == mc_addr) {
			read_unlock(&in_dev->lock);
			return 1;
		}
	}
	read_unlock(&in_dev->lock);
	return 0;
}


#ifdef CONFIG_IP_MULTICAST
 
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;

		querier = IGMP_V1_SEEN(in_dev) ? "V1" : "V2";

		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;
}
#endif