On Tue, Feb 19, 2019 at 12:46:08AM +0100, Andrew Lunn wrote:

On Mon, Feb 18, 2019 at 07:21:59PM +0100, Michal Kubecek wrote:

quoted

Three types of netlink notifications are introduced:

  - ETHA_EVENT_NEWDEV to notify about newly registered network devices
  - ETHA_EVENT_DELDEV to notify about unregistered network devices
  - ETHA_EVENT_RENAMEDEV to notify about renamed network device

The notifications are triggered by NETDEV_REGISTER, NETDEV_UNREGISTER and
NETDEV_CHANGENAME notifiers.

These notifications are intended for applications and daemons monitoring
ethtool events to allow updating the list of existing devices without
having to open another socket for rtnetlink.

Hi Michal

Does ETHA_EVENT_RENAMEDEV actually contain enough information to avoid
needing a rtnetlink lookup? If i understand the code correctly, all
you have is the new name. You don't know the old name?

Having said that, i don't see an easy way to get access to the old
name when handling the NETDEV_CHANGENAME.

We don't have the old name and without modifying the NETDEV_CHANGENAME
notifier to pass it, there is probably no way to get it. But the ethtool
notification also contains ifindex so that userspace applications which
want to track the configuration can remember both and identify the
renamed device by ifindex.

Michal