Ask HN: Looking for tool/language to describe data/packet structures

19 points by tinktank 3y ago ↗ HN

I'm looking or a tool that will allow me to textually describe data/packet structures for the purposes of creating visual representations of the structures. If it's capable of expressing constraints or assertations that would be even better. Examples of constraints/assertions:

- This field should always be n bits into the start of the structure - The size of this structure shouldn't exceed B bits - This field should never be less than s bits

The capability to output image formats directly is preferred, but I'm not opposed to having to script it and tie it up to an image generation library.

I'd prefer a CLI tool so the flow is all on my local machine.

4 comments

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jiveturkey 3y ago ↗

http://interactive.blockdiag.com/packetdiag/

https://github.com/arnoldrobbins/dformat

codegladiator 3y ago ↗

Checkout kaitai

https://doc.kaitai.io/

Its not for generating visual structure, but just defining the structure with the constraints like you mentioned

renewiltord 3y ago ↗

Protocol exists but is unmaintained (I think) https://www.luismg.com/protocol/

Wavedrom and ascii wave is for tming https://github.com/Wren6991/asciiwave

cookiengineer 3y ago ↗

In the network security space there's pcap-ng and yara that's pretty common as a network filter ruleset generator.

There's also a lof of visual IDEs for the creation of yara rules, which tend to break it down in a flow-based graph so that the logical conditions are easier to understand.

Yara is pretty flexible in what you can do with it, a lot of anti malware tools use it for detection, as well as more modern hex editors like ImHex.

Older-generation tech used to use snort and its rule format, especially in the Enterprise space it's (sadly) still common.