Re: [PATCH net-next 2/2 v4] netns: send uevent messages

[David Miller <davem@davemloft.net>]

From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Mon, 19 Mar 2018 13:17:31 +0100

> This patch adds a receive method to NETLINK_KOBJECT_UEVENT netlink sockets
> to allow sending uevent messages into the network namespace the socket
> belongs to.
> 
> Currently non-initial network namespaces are already isolated and don't
> receive uevents. There are a number of cases where it is beneficial for a
> sufficiently privileged userspace process to send a uevent into a network
> namespace.
> 
> One such use case would be debugging and fuzzing of a piece of software
> which listens and reacts to uevents. By running a copy of that software
> inside a network namespace, specific uevents could then be presented to it.
> More concretely, this would allow for easy testing of udevd/ueventd.
> 
> This will also allow some piece of software to run components inside a
> separate network namespace and then effectively filter what that software
> can receive. Some examples of software that do directly listen to uevents
> and that we have in the past attempted to run inside a network namespace
> are rbd (CEPH client) or the X server.
 ...
> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Applied.