Re: LUA?

From: SM <sm_at_resistor.net>
Date: Sat, 10 Oct 2009 07:33:24 -0700

At 16:44 09-10-2009, Murray S. Kucherawy wrote:
>Realizing that policy decisions may become more complex as time goes
>on and DKIM grows, I'm concerned that our current model of fixed
>lists or add-on databases may not scale.
>
>I'm investigating LUA as a scripting language that could be built in
>to opendkim. I envision the filter making available to the script
>all the details about all of the signatures (if any) in a message,
>kind of like the libopendkim callback facility we have now, and then
>provide primitives like "retrieve MTA macro", "retrieve signature
>property", "perform policy query", etc.
>
>First, is this a crazy idea?

It's a good idea. What you are thinking is something along the lines
of Sieve for policy-based filtering. The fixed lists and add-on
databases are good but they cannot be used to apply specific policies
based on several inputs.

>Second, anyone on the list have experience using LUA with C?

I dabbled with LUA and C.

At 22:44 09-10-2009, Daniel Black wrote:
>I'm slightly concerned that the LuaSQL seems rather stagnant with the last
>commits about 6 months ago with some google SOC support for firebird going on.

It doesn't have to be LuaSQL. What Murray is talking about is
something like Sieve where you take several inputs to determine what
to do with the message.

>Some questions about the LUA choice.
>
>why lua?

Because it has a small footprint.

>why tie into a language? perhaps a socket interface through unix/tcp sockets

If it's not a language, it will have to be a protocol. The
end-result is the same.

>performance: honestly not that concerned here. I suspect most delays
>are going
>to be retrieval of information to support policy choices.

Performance is a concern.

Regards,
-sm
Received on Sat Oct 10 2009 - 14:34:05 PST