Re: [Qemu-devel] [PATCH V2] net/traffic-mirror:Add traffic-mirror

[Li Zhijian]

On 02/01/2016 10:57 AM, Jason Wang wrote:
> On 01/29/2016 09:38 AM, Li Zhijian wrote:
> > On 01/28/2016 01:44 PM, Jason Wang wrote:
> > > On 01/27/2016 10:40 AM, Zhang Chen wrote:
> > > > From: ZhangChen <address@hidden>
> > > >
> > > > Traffic-mirror is a netfilter plugin.
> > > > It gives qemu the ability to copy and mirror guest's
> > > > net packet. we output packet to chardev.
> > > >
> > > > usage:
> > > >
> > > > -netdev tap,id=hn0
> > > > -chardev socket,id=mirror0,host=ip_primary,port=X,server,nowait
> > > > -traffic-mirror,id=m0,netdev=hn0,queue=tx/rx/all,outdev=mirror0
> > > >
> > > > Signed-off-by: ZhangChen <address@hidden>
> > > > Signed-off-by: Wen Congyang <address@hidden>
> > > > Reviewed-by: Yang Hongyang <address@hidden>
> > >
> > > Thanks for the patch. Several questions:
> > >
> > > - I'm curious about how the patch was tested? Simple setup e.g:
> > >
> > > -netdev tap,id=hn0 -device virtio-net-pci,netdev=hn0 -chardev
> > > socket,id=c0,host=localhost,port=4444,server,nowait -object
> > > traffic-mirror,netdev=hn0,outdev=c0,id=f0 -netdev
> > > socket,id=s0,connect=127.0.0.1:4444 -device e1000,netdev=s0

a strange thing is about "host=localhost", connection is refused at SUSE 11.3 
but
connection is connected successfully at Ubuntu 15.10 if i launch qemu with the
command line above.
I try to launch qemu at three physical machines installed with SUSE 11.3, they 
all
connect failed. But when I specified "host=127.0.0.1", the connection is OK.

I have comfirmed that:
- "localhost have pointed to 127.0.0.1 if I "ping localhost" at SUSE
- "telnet localhost 4444" works at SUSE


> > > does not works for me.
> > Hi， Jason
> >
> > I just test the mirror using the command line above, it don't work too.
> > I am looking to it, and find that seems because the -net socket
> > problem that
> > I have ever post a patch  try to fix（refer to ↓）
> > [Qemu-devel] [PATCH] report a error message if -net socket can not
> > connect to server
> > https://lists.gnu.org/archive/html/qemu-devel/2015-12/msg00758.html
>
> Will have a look at this.
>
> > after applying this patch, the qemu monitor tell me following message:
> > (qemu) qemu-system-x86_64: net socket is not connected Connection refused
>
> Maybe two issues. Have you tired to start the mirror on one VM and then
> using socket backend to connect it from another VM?

Yes, if i connect the mirror on VM1 using socket backend from another VM2, the 
connection
is established successfully. But on VM2 guest, I can't dump any packet using 
'tcpdump'
That's because in current version code, mirror is not compatible with socket 
backend and
we will fix it in next version.


Best regards.
Li Zhijian

> > Thanks
> > Li Zhijian
>
>
>
> .