Add First Packet Classification capability

[IvanNardi]

In some contexts/deployments (load-balancing or QoS involved, routing on different interfaces based on classification...) is quite important to have a flow classification on the very FIRST packet of the flow, even if that classification is not as precise as it could be if more packets are analyzed.

Note that, for TCP, "first packet" means (usually) the SYN packet...

[mmanoj]

@IvanNardi

This is good to have,I like to implement this feature, if you can guide me.