Re: VRF-like use of Network Namespaces

[ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman)]

Mathieu Peresse <mathieu.peresse-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:

> Hi,
>
> [this is related to the use of Eric Biederman's new set of patches for named
> netns / netns switching]
>
> ok so I successfully modified /sbin/ip. I can now:
> - add/del a new netns by name: "ip netns {addns,delns} ns_name"
> -> The namespace files are mounted on /var/run/netns/ns_name (so you have to
> mkdir /var/run/netns/ for this to work).
> - list netns: "ip netns show"
> - use /sbin/ip in any named netns: "ip -netns ns_name link show"
>
> (rough patch against current git tree attached)
>
> I want now to move devices across namespaces using their filesystem names
> (instead of using PIDs...). I'm not sure I can do it in userspace with the
> current code yet, can I ?
> I saw there was a rtnetlink attribute to set the netns of a device but it
> uses the PID of a namespace owner to do so... within 'ip' i can refer to
> only one namespace (i.e. the one that 'ip' task_struct->ns_proxy currently
> points to), so I won't be able to move an interface from outside my
> namespace to my namespace...
> I hope my explanation is clear and that this will get some interest... :)

In my nsfd tree if you look there is a new IFLA_NET_NS_FD attribute so should
be able to update the existing code in ip that takes a netns by pid, and do
a name based search first, and if you don't find the name and the value is
numeric do a search by ip.

> BTW is this the right ML to post this on ?

For hashing out the idea this is fine.  Ultimately this conversation needs
to hit netdev, before we merge all of this.

That rough patch looks particularly promising.

Eric