SO_PEERLABEL. This provides an interface to query the label of a
socket peer without embedding implementation details of mac_t in
the application. Previously, sizeof(*mac_t) had to be specified
by an application when performing getsockopt().
Document mac_get_peer(3), and expand documentation of the other
mac_get(3) functions. Note that it's possible to get EINVAL back
from mac_get_fd(3) when pointing it at an inappropriate object.
NOTE: mac_get_fd() and mac_set_fd() support for sockets will
follow shortly, so the documentation is slightly ahead of the
code.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories