Node to run before "vxlan4-input"

[AbhishekRamamurthy]

I want to run a node right before vxlan_input is triggered, I see that vxlan node is registered with FIB. Is ".runs_before" applicable to fib nodes and I register my new node as child to FIB_NODE_TYPE_VXLAN_TUNNEL ?. I didn't try or implement anything yet trying to gather information in before I being writing code.