[cups] Throttle CUPS-Get-Printers requests from clients

[Alex Korobkin]

Hi all,

I frequently encounter misbehaving Linux clients that poll central
printserver several times per second with CUPS-Get-Printers requests. Usual
culprits are Gnome printing dialog and Chrome browser, but I have no
control over clients' machines and cannot upgrade their software or fix it
in any way.

Is there a way to limit the number of requests that a single client can
make per second?
Currently a handful of clients can easily DoS a CUPS server with this.

-- 
-Alex