During the recent merge between master and master-next the changes introduced
by PR #80 were lost. This commit adds them back with some refactoring to use
the new netlink cache.
Co-authored-by: Maximilian Wilhelm <max@sdn.clinic> Co-authored-by: Julien Fortin <julien@cumulusnetworks.com> Signed-off-by: Maximilian Wilhelm <max@sdn.clinic> Signed-off-by: Julien Fortin <julien@cumulusnetworks.com>