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>

1 files changed, 4 insertions, 1 deletions

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 97ba0189c6f7..caa3f6919436 100644
--- a/net/bridge/br_netlink.c
+++ b/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;