the default label support in /etc/mac.conf. Rather than maintain
each default label type in an explicit global variable in mac.c,
keep a list of defaults loaded from the configuration file.
Generalize the parsing so that we support both the older:
default_file_labels foo
default_ifnet_labels foo
default_process_labels foo
And also a new:
default_labels file foo
default_labels ifnet foo
default_labels process foo
We now accept arbitrary object classes in the first argument. If
the same object is specified more than once, we discard the
earlier definition in favor of the later one.
Add a new API, mac_prepare_type(), which accepts a mac_t to
prepare, as well as an object name in the second argument, which
will pull a default label set for the object out of the
configuration loaded by mac_init_internal(). This permits the libc
to adapt to new objects known about by applications but not by libc
at compile-time.
Also liberalize the error handling a bit: if we're using implicit
initialization (i.e., the application didn't explicitly initialize
the MAC code), ignore syntax errors and only use valid lines. In
the future, we may want to add explicit warnings and do this a
bit more consistently.
While here, add support for a MAC_CONFFILE environmental variable,
which may be used to specify an alternative mac.conf configuration
file if the application isn't running with modified privilege
(issetugid()).
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
a3a7830365