Re: [PATCH net-next 3/3] net/sched: Introduce act_iptunnel

[Amir Vadai <amir@vadai.me>]

On Tue, Aug 23, 2016 at 05:33:49PM +0200, Jiri Benc wrote:
> On Tue, 23 Aug 2016 18:28:05 +0300, Amir Vadai wrote:
> > On Mon, Aug 22, 2016 at 08:51:37PM +0200, Jiri Benc wrote:
> > > 2. We may run into problems like tx path seeing the metadata_dst that
> > >    it should not see. This means either this situation or such
> > >    configuration must be prevented somehow.
> [...]
> > Anyway, this issue is orthogonal to this patchset...
> 
> Not really. If it's indeed (2) then such configuration needs to be
> rejected. 
The configuration that needs to be rejected is when act_iptunnel is not
used. So, I guess the fix won't be part of it...

> Or metadata_dst freed at an appropriate place. Thus it's
> something that needs to be handled by this patchset before the uAPI is
> set in stone.
It is already there - user can use act_mirred and redirect skb's with
metadata since shared tunnel devices introduced.
The only thing that was added here, is to enable the user to drop the
metadata, which I think we agree is the ok.

But I agree with you, that I must understand the life cycle of the metadata and dst
better. I will try to understand it better and explain/fix accordingly.

Again, would be happy if someone will chime in and give some hints if it
was a bug, that a user could redirect skb's with metadata, or something
harmless.

Thanks,
Amir
> 
>  Jiri