Add policy for the new TUN driver access controls which allow policy to
control which domains have the ability to create and attach to TUN/TAP
devices. The policy rules for creating and attaching to a device are as
shown below:
# create a new device
allow domain_t self:tun_socket { create };
# attach to a persistent device (created by tunlbl_t)
allow domain_t tunlbl_t:tun_socket { relabelfrom };
allow domain_t self:tun_socket { relabelto };
Further discussion can be found on this thread:
* http://marc.info/?t=125080850900002&r=1&w=2
Signed-off-by: Paul Moore <paul.moore@hp.com>