[libvirt] Feature Request: sniff a virtual interface of a guest

[Hendrik Schwartke]

Hi Dave,

I'm using libvirt for quite a while but I'm relatively new to the code.
So thank you for your hints. I will have a look at the streaming api 
this week.

Thanks
Hendrik


On 27.01.2012 15:39, Dave Allan wrote:
> On Fri, Jan 27, 2012 at 09:28:21AM +0100, Hendrik Schwartke wrote:
>> Hi,
>>
>> there is currently no support for sniffing the network traffic of a virtual
>> nic, from local or remote. In some cases the debugging or monitoring of a guest
>> is therefore not as easy as it could be.
>>
>> Although it's easy to start a network sniffer on the physical host, it requires
>> direct access to a shell and some knowledge of the current configuration of
>> the virtual networks.
>>
>> I think it would be a great benefit for libvirt if network sniffing would be
>> possible out of the box.
> Cool idea.
>
>> One idea would be to start a local tshark sniffing on the card and connect this
>> to a local socket. This could then be forwarded by ssh to a wireshark process
>> running on a desktop.
> I would favor doing the minimum in libvirt side to specify a packet
> filter and a start/stop of the packet mirror, and then let the user
> consume the resulting packet stream however they want on the client.
> Other people may have more concrete suggestions.
>
>> I created a feature request for that: https://bugzilla.redhat.com/show_bug.cgi?id=784893
>>
>> Any thoughts or hints to implement that?
> This seems like a good candidate for using libvirt's support for
> streaming data, similar to consoles or screenshots.  Take a look
> through the code for how those APIs are implemented for a guide.
>
> I'm not sure how familiar you are with the libvirt code, so forgive me
> if you already know this: if you start with tools/virsh.c you can see
> how the virsh console and virsh screenshot commands call their
> respective APIs and then how those APIs use libvirt's streams to
> deliver the resulting data.
>
> Dave
>
>> Hendrik Schwartke
>>
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