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Date: Wed, 08 Jul 2009 13:21:48 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [PATCH 3/5] Add getfd and closefd monitor commands
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To: Avi Kivity <avi@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>, qemu-devel@nongnu.org

Avi Kivity wrote:
> On 07/08/2009 09:08 PM, Anthony Liguori wrote:
>> Avi Kivity wrote:
>>> I'd prefer the communication layer to queue fds and getfd to dequeue 
>>> them.
>>
>> How many do you queue?  The correct answer is one, btw ;-)
>
> You queue as many as you receive, and you dequeue as many getfd 
> commands as you get.

Then someone can connect to the monitor and consume an arbitrary number 
of fds?  I'd be very concerned about the potential to leak fds within 
QEMU from a poorly written client.  Seems like a very easy mistake to make.

> Nothing prevents the client from sending two getfd commands in a 
> single packet.  We can either support it or start writing detailed 
> documentation and handle the bug reports when people don't read it.

What would a client do that would result in this happening?  It's really 
a contrived example when you think about it pragmatically (at least 
given today's monitor).

Regards,

Anthony Liguori