[PATCHv3] Bridge: Always send NETDEV_CHANGEADDR up on br MAC change.

[Andrei Warkentin <andreiw@motorola.com>]

This ensures the neighbor entries associated with the bridge
dev are flushed, also invalidating the associated cached L2 headers.

This means we br_add_if/br_del_if ports to implement hand-over and
not wind up with bridge packets going out with stale MAC.

This means we can also change MAC of port device and also not wind
up with bridge packets going out with stale MAC.

This builds on Stephen Hemminger's patch, also handling the br_del_if
case, port MAC change case, and bridge MAC manual assignment case.

Cc: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrei Warkentin <andreiw@motorola.com>
---
 net/bridge/br_device.c |    1 +
 net/bridge/br_if.c     |    6 +++++-
 net/bridge/br_notify.c |    6 +++++-
 net/bridge/br_stp_if.c |    2 +-
 4 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index cf09fe5..ef18070 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -162,6 +162,7 @@ static int br_set_mac_address(struct net_device *dev, void *p)
 	br->flags |= BR_SET_MAC_ADDR;
 	spin_unlock_bh(&br->lock);
 
+	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
 	return 0;
 }
 
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 204e542..36ad887 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -481,6 +481,7 @@ put_back:
 int br_del_if(struct net_bridge *br, struct net_device *dev)
 {
 	struct net_bridge_port *p;
+	bool changed_addr;
 
 	if (!br_port_exists(dev))
 		return -EINVAL;
@@ -492,10 +493,13 @@ int br_del_if(struct net_bridge *br, struct net_device *dev)
 	del_nbp(p);
 
 	spin_lock_bh(&br->lock);
-	br_stp_recalculate_bridge_id(br);
+	changed_addr = br_stp_recalculate_bridge_id(br);
 	br_features_recompute(br);
 	spin_unlock_bh(&br->lock);
 
+	if (changed_addr)
+		call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
+
 	return 0;
 }
 
diff --git a/net/bridge/br_notify.c b/net/bridge/br_notify.c
index 404d4e1..651eac3 100644
--- a/net/bridge/br_notify.c
+++ b/net/bridge/br_notify.c
@@ -34,6 +34,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
 	struct net_device *dev = ptr;
 	struct net_bridge_port *p = br_port_get(dev);
 	struct net_bridge *br;
+	bool changed_addr;
 	int err;
 
 	/* not a port of a bridge */
@@ -51,8 +52,11 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
 	case NETDEV_CHANGEADDR:
 		spin_lock_bh(&br->lock);
 		br_fdb_changeaddr(p, dev->dev_addr);
-		br_stp_recalculate_bridge_id(br);
+		changed_addr = br_stp_recalculate_bridge_id(br);
 		spin_unlock_bh(&br->lock);
+
+		if (changed_addr)
+			call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 		break;
 
 	case NETDEV_CHANGE:
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index c0990ba..4528e9a 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -213,7 +213,7 @@ bool br_stp_recalculate_bridge_id(struct net_bridge *br)
 
 	/* user has chosen a value so keep it */
 	if (br->flags & BR_SET_MAC_ADDR)
-		return;
+		return false;
 
 	list_for_each_entry(p, &br->port_list, list) {
 		if (addr == br_mac_zero ||
-- 
1.7.0.4