[BRIDGE]: set features based on enslaved devices
Make features of the bridge pseudo-device be a subset of the underlying
devices. Motivated by Xen and others who use bridging to do failover.
Signed-off-by: Catalin BOIE <catab at umrella.ro>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 69872bf..91bb895 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -314,6 +314,28 @@
return mtu;
}
+/*
+ * Recomputes features using slave's features
+ */
+void br_features_recompute(struct net_bridge *br)
+{
+ struct net_bridge_port *p;
+ unsigned long features, checksum;
+
+ features = NETIF_F_SG | NETIF_F_FRAGLIST
+ | NETIF_F_HIGHDMA | NETIF_F_TSO;
+ checksum = NETIF_F_IP_CSUM; /* least commmon subset */
+
+ list_for_each_entry(p, &br->port_list, list) {
+ if (!(p->dev->features
+ & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM)))
+ checksum = 0;
+ features &= p->dev->features;
+ }
+
+ br->dev->features = features | checksum | NETIF_F_LLTX;
+}
+
/* called with RTNL */
int br_add_if(struct net_bridge *br, struct net_device *dev)
{
@@ -368,6 +390,7 @@
spin_lock_bh(&br->lock);
br_stp_recalculate_bridge_id(br);
+ br_features_recompute(br);
spin_unlock_bh(&br->lock);
return 0;
