I've created packaging for ebtables-dhcpsnooping. This included some mods to the upstream which might get pulled in by the upstream author, so for now the packaging points at my github fork.
Not having done this before, I probably have committed many sins. Let me know about suggested improvements, or send a PR.
It will show up as two package variants under Networking/FIrewall after you integrate the feed.
The packaging includes an init.d script to automatically set up the supporting ebtables rules. The (external) database will have to be set up by hand... instructions are included in comments in the client preferences config files.
Now... to find a relatively capable SQL server made for embedded use with small datasets so the central DB can run on a slightly beefy AP/switch... mysqld and postgresd are way too ram hungry. Suggestions welcome.