[rbldnsd] rbdnsd extension: fastlist

[Axb]

Hello all

5 years ago I brainstormed an idea with Michael and neither can remember 
why we never followed up on it.

When I knocked his door again, Michael's comment was:
"I hoped that after 5 years there will be no need in all this antispam 
stuff anymore.  Oh well."

Now, with Michaels attention, the basic idea is:

Enhance rbldnsd by adding "in memory" zones which can be instantly 
updated via a specially crafted query.
This would allow instant listings, avoid cron rsync lag

or maybe someone wnats to use memory based zones only and get instant 
delistings/expiration.

one use would be
#FILE BASED
list.example.net:list.example.net.rbldnsd
# MEMORY
list.example.net:fastlist.example.net

a query sent to blah.fastlist.example.net would add the IP/domain/hash 
to the in memory fastlist.example.net and made available to list.example.net

Memory TTL (FASTTTL) could be taken from a param in the parent zone file 
or if we want purely memory based zone, then via a value in rbldnsd 
config file/startup command
___
list.example.net.rbldnsd
# TTL 30
# FASTTTL 90
___

this could allow for easy config changes for remote rbldnsd instances by 
just by changing the FASTTTL at origin

In memory data could be purged after rbldnsd reloads rsync'd file zones.


Important subject to brainstorming: ACL methods


Comments, ideas?

Thx

Axb