Re: [net-next,v2,1/5] vrf: add mac header for tunneled packets when sniffer is attached

[Andrea Mayer]

Hi Jakub,

On Tue, 10 Nov 2020 14:50:45 -0800
Jakub Kicinski <kuba@xxxxxxxxxx> wrote:

> On Sat,  7 Nov 2020 16:31:35 +0100 Andrea Mayer wrote:
> > Before this patch, a sniffer attached to a VRF used as the receiving
> > interface of L3 tunneled packets detects them as malformed packets and
> > it complains about that (i.e.: tcpdump shows bogus packets).
> > 
> > The reason is that a tunneled L3 packet does not carry any L2
> > information and when the VRF is set as the receiving interface of a
> > decapsulated L3 packet, no mac header is currently set or valid.
> > Therefore, the purpose of this patch consists of adding a MAC header to
> > any packet which is directly received on the VRF interface ONLY IF:
> > 
> >  i) a sniffer is attached on the VRF and ii) the mac header is not set.
> > 
> > In this case, the mac address of the VRF is copied in both the
> > destination and the source address of the ethernet header. The protocol
> > type is set either to IPv4 or IPv6, depending on which L3 packet is
> > received.
> > 
> > Signed-off-by: Andrea Mayer <andrea.mayer@xxxxxxxxxxx>
> 
> Please keep David's review tag since you haven't changed the code.

I will keep David's review tag in v3.

Thanks,
Andrea