Commit 3b85f9ba authored by Linus Lüssing's avatar Linus Lüssing Committed by David S. Miller
Browse files

net: bridge: mcast: export multicast router presence adjacent to a port 



To properly support routable multicast addresses in batman-adv in a
group-aware way, a batman-adv node needs to know if it serves multicast
routers.

This adds a function to the bridge to export this so that batman-adv
can then make full use of the Multicast Router Discovery capability of
the bridge.

Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b7fb0916

include/linux/if_bridge.h

+8 −0
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ int br_multicast_list_adjacent(struct net_device *dev, 
			       struct list_head *br_ip_list);

bool br_multicast_has_querier_anywhere(struct net_device *dev, int proto);

bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto);

bool br_multicast_has_router_adjacent(struct net_device *dev, int proto);

bool br_multicast_enabled(const struct net_device *dev);

bool br_multicast_router(const struct net_device *dev);

int br_mdb_replay(struct net_device *br_dev, struct net_device *dev,
@@ -87,6 +88,13 @@ static inline bool br_multicast_has_querier_adjacent(struct net_device *dev, 
{

	return false;

}



static inline bool br_multicast_has_router_adjacent(struct net_device *dev,

						    int proto)

{

	return true;

}



static inline bool br_multicast_enabled(const struct net_device *dev)

{

	return false;

net/bridge/br_multicast.c

+55 −0
Original line number Diff line number Diff line
@@ -4054,6 +4054,61 @@ bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto) 
}

EXPORT_SYMBOL_GPL(br_multicast_has_querier_adjacent);



/**

 * br_multicast_has_router_adjacent - Checks for a router behind a bridge port

 * @dev: The bridge port adjacent to which to check for a multicast router

 * @proto: The protocol family to check for: IGMP -> ETH_P_IP, MLD -> ETH_P_IPV6

 *

 * Checks whether the given interface has a bridge on top and if so returns

 * true if a multicast router is behind one of the other ports of this

 * bridge. Otherwise returns false.

 */

bool br_multicast_has_router_adjacent(struct net_device *dev, int proto)

{

	struct net_bridge_port *port, *p;

	bool ret = false;



	rcu_read_lock();

	port = br_port_get_check_rcu(dev);

	if (!port)

		goto unlock;



	switch (proto) {

	case ETH_P_IP:

		hlist_for_each_entry_rcu(p, &port->br->ip4_mc_router_list,

					 ip4_rlist) {

			if (p == port)

				continue;



			ret = true;

			goto unlock;

		}

		break;

#if IS_ENABLED(CONFIG_IPV6)

	case ETH_P_IPV6:

		hlist_for_each_entry_rcu(p, &port->br->ip6_mc_router_list,

					 ip6_rlist) {

			if (p == port)

				continue;



			ret = true;

			goto unlock;

		}

		break;

#endif

	default:

		/* when compiled without IPv6 support, be conservative and

		 * always assume presence of an IPv6 multicast router

		 */

		ret = true;

	}



unlock:

	rcu_read_unlock();

	return ret;

}

EXPORT_SYMBOL_GPL(br_multicast_has_router_adjacent);



static void br_mcast_stats_add(struct bridge_mcast_stats __percpu *stats,

			       const struct sk_buff *skb, u8 type, u8 dir)

{