[skydancer]

Nice work! I had kludged something together earlier, but a plugin is a lot better. I've installed it and will test it out

I'm not sure I agree with the comments on caching. This plugin uses gethostbyname() to do a DNS request to the blocklist servers. This DNS request will be issued to the (colo provider's) DNS cache and that server will already cache the answer for you. This server will keep it in the cache as long as the TTL of the record in the blocklist, so you are caching it as long as the blocklist specifies it, which is often hours or days, and you have the best chance of having an up to date result, because your DNS takes care of caching and retrieving.

Caching would also make the code more complex and prone to errors, also it costs extra time for a feature that DNS already provides. A network DNS lookup is also often faster than a database table lookup and does not stress the disk.

When you check one blocklist, the network load is comparable to doing HostnameLookups On in Apache, which is minimal for all but the largest sites. If needed, I would advise checking a composite blocklist that mirrors many other lists, so you only spend one DNS packet in and out.