Network protocol structure definitions in machine readable form (xml,json,other?)?

I am looking for network protocol structure definitions in structured machine readable form, like xml, json or an other description language I'm currently not aware of.

I'm talking here about the standard stuff: Ethernet, IP, TCP, UDP, ICMP, etc. and everything else that can run through a network [cable and wireless]. Everything that can be sniffed with wireshark for example.

What I need for my upcoming project are all these protocol definitions in machine readable form, I do not care about in which clothing these definitions come along, I just need them.

Searching the 'interwebs' for such a "universal protocol structure definition" is like to look for a needle in a haystack and throws up everything, but that what I'm looking for.

I even cursorily checked the available code of wireshark in the hope to find something usable. (Which was not the case or I weren't looking deep enough...)

Does none exist and do I have to invent a new schema for the task?

Or does it just hide before my eyes in hours of search?

Thanks in advance, experts of stackoverflow. :)