[SSSD] [PATCH] libnl integration improvements

[Jakub Hrozek]

[PATCH 1/3] Change libnl monitor callback to only signal going online
The feature to signal going offline was not used and would probably
never be used, because it is much safer to rely on online actions to time
out. Moreover, it would make implementing the new features more complex.

[PATCH 2/3] Discard carrier messages from non-ethernet devices
IFF_LOWER_UP has no meaning for wireless interfaces, it can mean that an
association has been made with an access point, but it does not mean
that an addressing has been completed. 

Using IFF_LOWER_UP meant that we were generating spurious "go online"
messages.

This patch discards "carrier up" messages from interfaces that do not
look like ethernet devices, be it wifi, PPP, WIMAX, ...

[PATCH 3/3] Subscribe to netlink route and addr messages
https://fedorahosted.org/sssd/ticket/955

In addition to carrier up messages, also subscribe to any messages
describing that an address has been added or removed or routing table
changed.