[PATCH 2/7] bridge: Keep track of ports capable of flooding.

[Vlad Yasevich <vyasevic@redhat.com>]

Keep track of bridge ports that have unicast flooding turned on.
This will later be used by the algorithm to automatically manage
address programming and promisc mode.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
---
 net/bridge/br_if.c       | 60 ++++++++++++++++++++++++++++++++++++++++++++++--
 net/bridge/br_netlink.c  |  3 +++
 net/bridge/br_private.h  |  4 ++++
 net/bridge/br_sysfs_if.c |  6 ++++-
 4 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 54d207d..f072b34 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -27,6 +27,9 @@
 
 #include "br_private.h"
 
+static void br_add_flood_port(struct net_bridge_port *p, struct net_bridge *br);
+static void br_del_flood_port(struct net_bridge_port *p, struct net_bridge *br);
+
 /*
  * Determine initial path cost based on speed.
  * using recommendations from 802.1d standard
@@ -141,11 +144,14 @@ static void del_nbp(struct net_bridge_port *p)
 
 	br_ifinfo_notify(RTM_DELLINK, p);
 
+	list_del_rcu(&p->list);
+
+	if (p->flags & BR_FLOOD)
+		br_del_flood_port(p, br);
+
 	nbp_vlan_flush(p);
 	br_fdb_delete_by_port(br, p, 1);
 
-	list_del_rcu(&p->list);
-
 	dev->priv_flags &= ~IFF_BRIDGE_PORT;
 
 	netdev_rx_handler_unregister(dev);
@@ -383,6 +389,9 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
 	dev_disable_lro(dev);
 
 	list_add_rcu(&p->list, &br->port_list);
+
+	if (p->flags & BR_FLOOD)
+		br_add_flood_port(p, br);
 
 	netdev_update_features(br->dev);
 
@@ -455,3 +464,50 @@ int br_del_if(struct net_bridge *br, struct net_device *dev)
 
 	return 0;
 }
+
+static void br_add_flood_port(struct net_bridge_port *p, struct net_bridge *br)
+{
+	/* Increment the number of  flooding ports, and if we
+	 * only have 1 flooding port cache if for future use.
+	 */
+	br->n_flood_ports++;
+	if (br->n_flood_ports == 1)
+		br->c_flood_port = p;
+}
+
+static void br_del_flood_port(struct net_bridge_port *p, struct net_bridge *br)
+{
+	struct net_bridge_port *port;
+
+	/* Decrement the  number of flood port.
+	 * If we are deleting the current flood port, clear
+	 * the cached port.  If we are down to 1 flood port,
+	 * set it if it is not set.
+	 */
+	br->n_flood_ports--;
+	if (p == br->c_flood_port)
+		br->c_flood_port = NULL;
+
+	if (br->n_flood_ports == 1) {
+		list_for_each_entry(port, &p->br->port_list, list) {
+			if (port->flags & BR_FLOOD) {
+				br->c_flood_port = port;
+				break;
+			}
+		}
+	}
+}
+
+void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
+{
+	struct net_bridge *br = p->br;
+
+	/* We are only interested FLOOD flag */
+	if (!(mask & BR_FLOOD))
+		return;
+
+	if (p->flags & BR_FLOOD)
+		br_add_flood_port(p, br);
+	else
+		br_del_flood_port(p, br);
+}
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index e74b6d53..01382b9 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -328,6 +328,7 @@ static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 {
 	int err;
+	unsigned long old_flags = p->flags;
 
 	br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
 	br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
@@ -353,6 +354,8 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 		if (err)
 			return err;
 	}
+
+	br_port_flags_change(p, old_flags ^ p->flags);
 	return 0;
 }
 
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 3ba11bc..26a3987 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -290,6 +290,8 @@ struct net_bridge
 	struct timer_list		topology_change_timer;
 	struct timer_list		gc_timer;
 	struct kobject			*ifobj;
+	struct net_bridge_port		*c_flood_port;
+	u32				n_flood_ports;
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
 	u8				vlan_enabled;
 	struct net_port_vlans __rcu	*vlan_info;
@@ -415,6 +417,8 @@ int br_del_if(struct net_bridge *br, struct net_device *dev);
 int br_min_mtu(const struct net_bridge *br);
 netdev_features_t br_features_recompute(struct net_bridge *br,
 					netdev_features_t features);
+void br_port_flags_change(struct net_bridge_port *port,
+			  unsigned long mask);
 
 /* br_input.c */
 int br_handle_frame_finish(struct sk_buff *skb);
diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index 7f66aa4..9ff6691 100644
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c
@@ -51,7 +51,10 @@ static BRPORT_ATTR(_name, S_IRUGO | S_IWUSR,			\
 static int store_flag(struct net_bridge_port *p, unsigned long v,
 		     unsigned long mask)
 {
-	unsigned long flags = p->flags;
+	unsigned long flags;
+	unsigned long old_flags;
+
+	old_flags = flags = p->flags;
 
 	if (v)
 		flags |= mask;
@@ -60,6 +63,7 @@ static int store_flag(struct net_bridge_port *p, unsigned long v,
 
 	if (flags != p->flags) {
 		p->flags = flags;
+		br_port_flags_change(p, old_flags ^ flags);
 		br_ifinfo_notify(RTM_NEWLINK, p);
 	}
 	return 0;
-- 
1.8.5.3