bridge: respect RFC2863 operational state

The bridge link detection should follow the operational state
of the lower device, rather than the carrier bit. This allows devices
like tunnels that are controlled by userspace control plane to work
with bridge STP link management.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Reviewed-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_if.c

@@ -66,14 +66,14 @@ void br_port_carrier_check(struct net_bridge_port *p)
 	struct net_device *dev = p->dev;
 	struct net_bridge *br = p->br;
 
-	if (netif_running(dev) && netif_carrier_ok(dev))
+	if (netif_running(dev) && netif_oper_up(dev))
 		p->path_cost = port_cost(dev);
 
 	if (!netif_running(br->dev))
 		return;
 
 	spin_lock_bh(&br->lock);
-	if (netif_running(dev) && netif_carrier_ok(dev)) {
+	if (netif_running(dev) && netif_oper_up(dev)) {
 		if (p->state == BR_STATE_DISABLED)
 			br_stp_enable_port(p);
 	} else {
@@ -383,7 +383,7 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
 	spin_lock_bh(&br->lock);
 	changed_addr = br_stp_recalculate_bridge_id(br);
 
-	if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
+	if (netif_running(dev) && netif_oper_up(dev) &&
 	    (br->dev->flags & IFF_UP))
 		br_stp_enable_port(p);
 	spin_unlock_bh(&br->lock);

net/bridge/br_netlink.c

@@ -181,8 +181,11 @@ static int br_set_port_state(struct net_bridge_port *p, u8 state)
 	if (p->br->stp_enabled == BR_KERNEL_STP)
 		return -EBUSY;
 
+	/* if device is not up, change is not allowed
+	 * if link is not present, only allowable state is disabled
+	 */
 	if (!netif_running(p->dev) ||
-	    (!netif_carrier_ok(p->dev) && state != BR_STATE_DISABLED))
+	    (!netif_oper_up(p->dev) && state != BR_STATE_DISABLED))
 		return -ENETDOWN;
 
 	p->state = state;

net/bridge/br_notify.c

@@ -82,7 +82,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
 		break;
 
 	case NETDEV_UP:
-		if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP)) {
+		if (netif_running(br->dev) && netif_oper_up(dev)) {
 			spin_lock_bh(&br->lock);
 			br_stp_enable_port(p);
 			spin_unlock_bh(&br->lock);

net/bridge/br_stp_if.c

@@ -54,7 +54,7 @@ void br_stp_enable_bridge(struct net_bridge *br)
 	br_config_bpdu_generation(br);
 
 	list_for_each_entry(p, &br->port_list, list) {
-		if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
+		if (netif_running(p->dev) && netif_oper_up(p->dev))
 			br_stp_enable_port(p);
 
 	}