to a new mac_inet.c. This code is now conditionally compiled based
on inet support being compiled into the kernel.
Move socket related MAC Framework entry points from mac_net.c to a new
mac_socket.c.
To do this, some additional _enforce MIB variables are now non-static.
In addition, mbuf_to_label() is now mac_mbuf_to_label() and non-static.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, McAfee Research
