script to create freebsd firewall rules

Hi, I am looking for a script that will read a database and create rules in the freebsd IPFW rule set. Basically the rules will have standard open ports such as port 80 etc so that the machine will run. However ports such as 22 for shell will be always closed. What we then want to do is for a script to read the database of ports and IP addresses which are allowed access to the given ports and the rules to then be updated accordingly.