bridge: make bridge address settings sticky

Normally, the bridge just chooses the smallest mac address as the
bridge id and mac address of bridge device. But if the administrator
has explictly set the interface address then don't change it.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 7 insertions, 0 deletions

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index a6ffc6c2a69f..d9449df7cad5 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -87,6 +87,7 @@ static int br_set_mac_address(struct net_device *dev, void *p)
         spin_lock_bh(&br->lock);
         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
         br_stp_change_bridge_id(br, addr->sa_data);
+        br->flags |= BR_SET_MAC_ADDR;
         spin_unlock_bh(&br->lock);
 
         return 0;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 83ff5861c2d2..8593c9f6a302 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -92,6 +92,8 @@ struct net_bridge
         struct hlist_head               hash[BR_HASH_SIZE];
         struct list_head                age_list;
         unsigned long                   feature_mask;
+        unsigned long                   flags;
+#define BR_SET_MAC_ADDR         0x00000001
 
         /* STP */
         bridge_id                       designated_root;
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 1a4e5c37a0cf..9a52ac5b4525 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -214,6 +214,10 @@ void br_stp_recalculate_bridge_id(struct net_bridge *br)
         const unsigned char *addr = br_mac_zero;
         struct net_bridge_port *p;
 
+        /* user has chosen a value so keep it */
+        if (br->flags & BR_SET_MAC_ADDR)
+                return;
+
         list_for_each_entry(p, &br->port_list, list) {
                 if (addr == br_mac_zero ||
                     memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)