I have uploaded a script that is an approximation / translation of endwall.sh into pf for OpenBSD called endwall_pf.sh. The script runs, and pfctl says there aren't any errors but I don't think it's actually working. Right now I think this script is equivalent to the default /etc/pf.conf even though it looks fancy. I'll be doing some more reading and I'll figure out how the pf system works eventually. But here is my preliminary work anyways.

Available here and in the usual locations:

https://raw.githubusercontent.com/endwall2/endware_bsd/master/endwall_pf.sh

https://gitgud.io/Endwall/Endware_BSD/-/raw/master/endwall_pf.sh

http://nguipxnkrp3qrzrlduhsatpcpwehnblzmlkc5ifiumxq4z5jlh4lwvid.onion/endware_bsd/endwall_pf.sh

I estimate that I should have this working like I want in about 2 months. I'm a pf newb and I'm not sure that I have the chain set up correctly. After testing it seems to be not doing what I want. I'll be working on this on the side until it works. Maybe someone knowledgeable in pf can offer suggestions to help me fix it.

Thanks.

EDIT
Renamed to endwall_pf.sh since there are other firewalls for BSD like ipfw