[RFC PATCH net-next v2 0/5] netns: allow to identify peer netns

[Andy Lutomirski]

On Tue, Sep 23, 2014 at 6:20 AM, Nicolas Dichtel
<nicolas.dichtel at 6wind.com> wrote:
> The goal of this serie is to be able to multicast netlink messages with an
> attribute that identify a peer netns.
> This is needed by the userland to interpret some informations contained in
> netlink messages (like IFLA_LINK value, but also some other attributes in case
> of x-netns netdevice (see also
> http://thread.gmane.org/gmane.linux.network/315933/focus=316064 and
> http://thread.gmane.org/gmane.linux.kernel.containers/28301/focus=4239)).
>
> Ids are stored in the parent user namespace. These ids are valid only inside
> this user namespace. The user can retrieve these ids via a new netlink messages,
> but only if peer netns are in the same user namespace.

What about the parent / ancestors of the owning userns?  Can processes
in those usernses see any form of netns id?

--Andy