[Mimedefang] Adding support for learning our addresses

[David F. Skoll]

Philip Prindeville wrote:

> Hmmm....  I was wondering if we might want to call
> ioctl(...,  SIOCGIFCONF...) followed by SIOCGIFADDR to get the list
> of our IP addresses... So we can do some filtering on people claiming
> to be us.

http://search.cpan.org/~tpaba/Net-Ifconfig-Wrapper-0.09/

> I.e. if someone connects to me and says "helo 71.36.29.88" then I know
> for a fact that they aren't me...

That is a very popular test:
http://www.mimedefang.org/kwiki/index.cgi?UseHeloToCatchSpam2

> One other thing I thought about: what about detecting spammers, and
> then looking up the CIDR block that their address belongs to, and adding
> it to a blacklist automatically in filter_relay()?

Too many false-positives.  We own a measly 8 IP addresses where our
colo box sits.  If you block us because someone on our class C was bad,
that's unfair.

--
David.