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authorLinus Lüssing <linus.luessing@c0d3.blue>2021-05-13 15:20:53 +0200
committerDavid S. Miller <davem@davemloft.net>2021-05-13 14:04:31 -0700
commit3b85f9ba3480c1bcbebb2bb490822bec0e7a1201 (patch)
treef9bc58a8c7dda3a4295b32233870c977c6787a9c /net/bridge
parentb7fb0916544de44ce099d9f3b6129c86b484de25 (diff)
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: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge')
-rw-r--r--net/bridge/br_multicast.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index f234c48036c8..0703725527b3 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -4054,6 +4054,61 @@ unlock:
}
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)
{