Re: [Qemu-devel] [RFC PATCH v2 00/10] Add colo-proxy based on netfilter

[Jason Wang]

On 01/20/2016 03:44 PM, Wen Congyang wrote:
>> > 
>> > ...
>> > -chardev socket,id=comparer0,host=ip_primary,port=X,server,nowait
>> > -chardev socket,id=comparer1,host=ip_primary,port=Y,server,nowait
>> > -chardev socket,id=mirrorer0,host=ip_primary,port=Z,server,nowait
>> > -netdev tap,id=hn0
>> > -traffic-mirrorer netdev=hn0,id=t0,indev=comparer0,outdev=mirrorer0
>> > -colo-comparer primary_traffic=comparer0,secondary_traffic=comparer1
>> > ...
>> > 
>> > packet comparer compares the packets from two chardev: comparer0 and
>> > comparer1.
>> > traffic-mirrorer mirror tx to secondary node through chardev mirrorer0,
>> > and mirror rx to packet comparer through chardev comparer0.
>> > 
>> > In secondary node:
>> > 
>> > ...
>> > -chardev socket,id=redirector0,host=ip_primary,port=Y
>> > -chardev socket,id=redirector1,host=ip_primary,port=Z
>> > -netdev tap,id=hn0
>> > -traffic-redirector netdev=hn0,id,r0,indev=redirector0,outdev=redirector1
>> > -colo-rewriter netdev=hn0,id=c0
>> > ...
>> > 
>> > traffic-redirector redirect the rx traffic from primary node through
>> > redirector0 and redirect the tx traffic to promary node through 
>> > redirector1.
>> > colo-rewriter rewrite seq number as a normal netfilter.
> What are traffic-mirrorer and colo-comparer, traffic-redirector, 
> colo-rewriter?
> A netfilter driver?

traffic-mirrorer/redirector is a type of netfilter that just
mirror/redirect packets between netdev and chardev (just the mirror
client/sever and redirect client/sever in the above graph)
colo-rewriter is a type of netfilter that did ack/seq adjust (just the
TCP rewriter in the above graph)
colo-comparer is a thread object that did packet comparing (similar to
"compare" in the above graph but not a netfiler)

>
> If not, how to get the packet from the netdev, and send back the packet to
> the netdev?
>
> Thanks
> Wen Congyang
>