Suricata

decode.h seems to have some unused macros, functions that could replace macros, as well as functions that are named similarly than macros, but have slightly different behaviors.

I think it would be beneficial to go over the file and remove unused code and replace macros for functions when possible.

An interesting example is the PACKET_SET_ACTION macro - we have a PacketSetAction function which calls the macro, but takes into account packet tunneling - which doesn't seem to be accounted for in the corresponding macro.