Get a list of currently active IMAP connections?

[Jaroslaw Rafa]

Hello Dovecot community,

I have a question: is it possible to programmatically get from Dovecot a
list of currently active IMAP sessions (with IP addresses)? Via a plugin or
something?

Or just check if there is an IMAP session currently open from a particular IP
address, with true/false type answer?

I'm planning to implement a policy service for *Postfix* that will revive
the old "POP before SMTP" authorization concept (only it will be "IMAP
before SMTP" this time). This policy service will reject connections to
mail submission ports (465, 587) - without even going to SMTP AUTH phase -
unless the connecting IP address has currently an IMAP session open to
Dovecot, to mitigate SMTP AUTH attacks.

But for this I need some way to check from within this policy service if the
particular IP address has a connection open or not. It could be of course
obtained by scanning Dovecot logs, but this involves quite a large overhead.
Therefore I'm looking for the way to get this information directly from
Dovecot's current state.

Can you advise me of any way to do this?

Or maybe someone has already written such a piece of software and it is
available somewhere on the Net?
-- 
Regards,
   Jaroslaw Rafa
   raj at rafa.eu.org
--
"In a million years, when kids go to school, they're gonna know: once there
was a Hushpuppy, and she lived with her daddy in the Bathtub."