bridge: Keep track of ports capable of automatic discovery.

By default, ports on the bridge are capable of automatic
discovery of nodes located behind the port.  This is accomplished
via flooding of unknown traffic (BR_FLOOD) and learning the
mac addresses from these packets (BR_LEARNING).
If the above functionality is disabled by turning off these
flags, the port requires static configuration in the form
of static FDB entries to function properly.

This patch adds functionality to keep track of all ports
capable of automatic discovery.  This will later be used
to control promiscuity settings.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 24 insertions, 0 deletions

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 5262b86..f7ef5f2 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -85,6 +85,18 @@ void br_port_carrier_check(struct net_bridge_port *p)
 	spin_unlock_bh(&br->lock);
 }
 
+static void nbp_update_port_count(struct net_bridge *br)
+{
+	struct net_bridge_port *p;
+	u32 cnt = 0;
+
+	list_for_each_entry(p, &br->port_list, list) {
+		if (br_auto_port(p))
+			cnt++;
+	}
+	br->auto_cnt = cnt;
+}
+
 static void release_nbp(struct kobject *kobj)
 {
 	struct net_bridge_port *p
@@ -146,6 +158,8 @@ static void del_nbp(struct net_bridge_port *p)
 
 	list_del_rcu(&p->list);
 
+	nbp_update_port_count(br);
+
 	dev->priv_flags &= ~IFF_BRIDGE_PORT;
 
 	netdev_rx_handler_unregister(dev);
@@ -384,6 +398,8 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
 
 	list_add_rcu(&p->list, &br->port_list);
 
+	nbp_update_port_count(br);
+
 	netdev_update_features(br->dev);
 
 	if (br->dev->needed_headroom < dev->needed_headroom)
@@ -455,3 +471,11 @@ int br_del_if(struct net_bridge *br, struct net_device *dev)
 
 	return 0;
 }
+
+void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
+{
+	struct net_bridge *br = p->br;
+
+	if (mask & BR_AUTO_MASK)
+		nbp_update_port_count(br);
+}