Good suggestion. To be honest, Cgo was the easiest for me to implement, as I originally wrote the tool in a different language. Also, most of the documentation for Netfilter and SO_ORIGINAL_DST is in C.

As for results: I’m seeing about one 'hit' per second on a standard VPS. It's a constant stream of bots looking for exploitable systems and probes from scanners like Shodan and Censys. It’s actually surprising how quickly a new IP gets picked up by these crawlers.