Change the return type of vxlan_snoop() from bool to enum skb_drop_reason. In this commit, two drop reasons are introduced: SKB_DROP_REASON_MAC_INVALID_SOURCE SKB_DROP_REASON_VXLAN_ENTRY_EXISTS Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>