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Commit 5c506802 authored by Linus Lüssing's avatar Linus Lüssing Committed by Simon Wunderlich
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batman-adv: mcast: collect softif listeners from IP lists instead 



Instead of collecting multicast MAC addresses from the netdev hw mc
list collect a node's multicast listeners from the IP lists and convert
those to MAC addresses.

This allows to exclude addresses of specific scope later. On a
multicast MAC address the IP destination scope is not visible anymore.

Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
parent 6bc45440

net/batman-adv/multicast.c

+143 −49
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/igmp.h>

#include <linux/in.h>

#include <linux/in6.h>

#include <linux/inetdevice.h>

#include <linux/ip.h>

#include <linux/ipv6.h>

#include <linux/jiffies.h>
@@ -172,70 +173,129 @@ static struct net_device *batadv_mcast_get_bridge(struct net_device *soft_iface) 
}



/**

 * batadv_mcast_addr_is_ipv4() - check if multicast MAC is IPv4

 * @addr: the MAC address to check

 * batadv_mcast_mla_is_duplicate() - check whether an address is in a list

 * @mcast_addr: the multicast address to check

 * @mcast_list: the list with multicast addresses to search in

 *

 * Return: True, if MAC address is one reserved for IPv4 multicast, false

 * otherwise.

 * Return: true if the given address is already in the given list.

 * Otherwise returns false.

 */

static bool batadv_mcast_addr_is_ipv4(const u8 *addr)

static bool batadv_mcast_mla_is_duplicate(u8 *mcast_addr,

					  struct hlist_head *mcast_list)

{

	static const u8 prefix[] = {0x01, 0x00, 0x5E};

	struct batadv_hw_addr *mcast_entry;



	return memcmp(prefix, addr, sizeof(prefix)) == 0;

	hlist_for_each_entry(mcast_entry, mcast_list, list)

		if (batadv_compare_eth(mcast_entry->addr, mcast_addr))

			return true;



	return false;

}



/**

 * batadv_mcast_addr_is_ipv6() - check if multicast MAC is IPv6

 * @addr: the MAC address to check

 * batadv_mcast_mla_softif_get_ipv4() - get softif IPv4 multicast listeners

 * @dev: the device to collect multicast addresses from

 * @mcast_list: a list to put found addresses into

 * @flags: flags indicating the new multicast state

 *

 * Return: True, if MAC address is one reserved for IPv6 multicast, false

 * otherwise.

 * Collects multicast addresses of IPv4 multicast listeners residing

 * on this kernel on the given soft interface, dev, in

 * the given mcast_list. In general, multicast listeners provided by

 * your multicast receiving applications run directly on this node.

 *

 * Return: -ENOMEM on memory allocation error or the number of

 * items added to the mcast_list otherwise.

 */

static bool batadv_mcast_addr_is_ipv6(const u8 *addr)

static int

batadv_mcast_mla_softif_get_ipv4(struct net_device *dev,

				 struct hlist_head *mcast_list,

				 struct batadv_mcast_mla_flags *flags)

{

	static const u8 prefix[] = {0x33, 0x33};

	struct batadv_hw_addr *new;

	struct in_device *in_dev;

	u8 mcast_addr[ETH_ALEN];

	struct ip_mc_list *pmc;

	int ret = 0;



	if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4)

		return 0;



	rcu_read_lock();



	return memcmp(prefix, addr, sizeof(prefix)) == 0;

	in_dev = __in_dev_get_rcu(dev);

	if (!in_dev) {

		rcu_read_unlock();

		return 0;

	}



	for (pmc = rcu_dereference(in_dev->mc_list); pmc;

	     pmc = rcu_dereference(pmc->next_rcu)) {

		ip_eth_mc_map(pmc->multiaddr, mcast_addr);



		if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))

			continue;



		new = kmalloc(sizeof(*new), GFP_ATOMIC);

		if (!new) {

			ret = -ENOMEM;

			break;

		}



		ether_addr_copy(new->addr, mcast_addr);

		hlist_add_head(&new->list, mcast_list);

		ret++;

	}

	rcu_read_unlock();



	return ret;

}



/**

 * batadv_mcast_mla_softif_get() - get softif multicast listeners

 * batadv_mcast_mla_softif_get_ipv6() - get softif IPv6 multicast listeners

 * @dev: the device to collect multicast addresses from

 * @mcast_list: a list to put found addresses into

 * @flags: flags indicating the new multicast state

 *

 * Collects multicast addresses of multicast listeners residing

 * Collects multicast addresses of IPv6 multicast listeners residing

 * on this kernel on the given soft interface, dev, in

 * the given mcast_list. In general, multicast listeners provided by

 * your multicast receiving applications run directly on this node.

 *

 * If there is a bridge interface on top of dev, collects from that one

 * instead. Just like with IP addresses and routes, multicast listeners

 * will(/should) register to the bridge interface instead of an

 * enslaved bat0.

 *

 * Return: -ENOMEM on memory allocation error or the number of

 * items added to the mcast_list otherwise.

 */

#if IS_ENABLED(CONFIG_IPV6)

static int

batadv_mcast_mla_softif_get(struct net_device *dev,

batadv_mcast_mla_softif_get_ipv6(struct net_device *dev,

				 struct hlist_head *mcast_list,

				 struct batadv_mcast_mla_flags *flags)

{

	bool all_ipv4 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4;

	bool all_ipv6 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6;

	struct net_device *bridge = batadv_mcast_get_bridge(dev);

	struct netdev_hw_addr *mc_list_entry;

	struct batadv_hw_addr *new;

	struct inet6_dev *in6_dev;

	u8 mcast_addr[ETH_ALEN];

	struct ifmcaddr6 *pmc6;

	int ret = 0;



	netif_addr_lock_bh(bridge ? bridge : dev);

	netdev_for_each_mc_addr(mc_list_entry, bridge ? bridge : dev) {

		if (all_ipv4 && batadv_mcast_addr_is_ipv4(mc_list_entry->addr))

	if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6)

		return 0;



	rcu_read_lock();



	in6_dev = __in6_dev_get(dev);

	if (!in6_dev) {

		rcu_read_unlock();

		return 0;

	}



	read_lock_bh(&in6_dev->lock);

	for (pmc6 = in6_dev->mc_list; pmc6; pmc6 = pmc6->next) {

		if (IPV6_ADDR_MC_SCOPE(&pmc6->mca_addr) <

		    IPV6_ADDR_SCOPE_LINKLOCAL)

			continue;



		if (all_ipv6 && batadv_mcast_addr_is_ipv6(mc_list_entry->addr))

		ipv6_eth_mc_map(&pmc6->mca_addr, mcast_addr);



		if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))

			continue;



		new = kmalloc(sizeof(*new), GFP_ATOMIC);
@@ -244,36 +304,70 @@ batadv_mcast_mla_softif_get(struct net_device *dev, 
			break;

		}



		ether_addr_copy(new->addr, mc_list_entry->addr);

		ether_addr_copy(new->addr, mcast_addr);

		hlist_add_head(&new->list, mcast_list);

		ret++;

	}

	netif_addr_unlock_bh(bridge ? bridge : dev);



	if (bridge)

		dev_put(bridge);

	read_unlock_bh(&in6_dev->lock);

	rcu_read_unlock();



	return ret;

}

#else

static inline int

batadv_mcast_mla_softif_get_ipv6(struct net_device *dev,

				 struct hlist_head *mcast_list,

				 struct batadv_mcast_mla_flags *flags)

{

	return 0;

}

#endif



/**

 * batadv_mcast_mla_is_duplicate() - check whether an address is in a list

 * @mcast_addr: the multicast address to check

 * @mcast_list: the list with multicast addresses to search in

 * batadv_mcast_mla_softif_get() - get softif multicast listeners

 * @dev: the device to collect multicast addresses from

 * @mcast_list: a list to put found addresses into

 * @flags: flags indicating the new multicast state

 *

 * Return: true if the given address is already in the given list.

 * Otherwise returns false.

 * Collects multicast addresses of multicast listeners residing

 * on this kernel on the given soft interface, dev, in

 * the given mcast_list. In general, multicast listeners provided by

 * your multicast receiving applications run directly on this node.

 *

 * If there is a bridge interface on top of dev, collects from that one

 * instead. Just like with IP addresses and routes, multicast listeners

 * will(/should) register to the bridge interface instead of an

 * enslaved bat0.

 *

 * Return: -ENOMEM on memory allocation error or the number of

 * items added to the mcast_list otherwise.

 */

static bool batadv_mcast_mla_is_duplicate(u8 *mcast_addr,

					  struct hlist_head *mcast_list)

static int

batadv_mcast_mla_softif_get(struct net_device *dev,

			    struct hlist_head *mcast_list,

			    struct batadv_mcast_mla_flags *flags)

{

	struct batadv_hw_addr *mcast_entry;

	struct net_device *bridge = batadv_mcast_get_bridge(dev);

	int ret4, ret6 = 0;



	hlist_for_each_entry(mcast_entry, mcast_list, list)

		if (batadv_compare_eth(mcast_entry->addr, mcast_addr))

			return true;

	if (bridge)

		dev = bridge;



	return false;

	ret4 = batadv_mcast_mla_softif_get_ipv4(dev, mcast_list, flags);

	if (ret4 < 0)

		goto out;



	ret6 = batadv_mcast_mla_softif_get_ipv6(dev, mcast_list, flags);

	if (ret6 < 0) {

		ret4 = 0;

		goto out;

	}



out:

	if (bridge)

		dev_put(bridge);



	return ret4 + ret6;

}



/**