add support for the RTA_VIA attribute

Add support for the RTA_VIA attribute that specifies an address family
as well as an address for the next hop gateway.

To make it easy to pass this reorder inet_prefix so that it's tail
is a proper RTA_VIA attribute.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
3 files changed