Return information about network interface named IFNAME.
The return value is a list (ADDR BCAST NETMASK HWADDR FLAGS),
where ADDR is the layer 3 address, BCAST is the layer 3 broadcast address,
NETMASK is the layer 3 network mask, HWADDR is the layer 2 address, and
FLAGS is the current flags of the interface.
(fn IFNAME)