MAC.CONF(5) FreeBSD File Formats Manual MAC.CONF(5)


mac.confformat of the MAC library configuration file


The mac.conf file configures the default label elements to be used by policy-agnostic applications that operate on MAC labels. A file contains a series of default label sets specified by object class, in addition to blank lines and comments preceded by a ‘ #’ symbol.

Currently, the implementation supports two syntax styles for label element declaration. The old (deprecated) syntax consists of a single line with two fields separated by white space: the object class name, and a list of label elements as used by the mac_prepare(3) library calls prior to an application invocation of a function from mac_get(3).

The newer more preferred syntax consists of three fields separated by white space: the label group, object class name and a list of label elements.

Label element names may optionally begin with a ‘ ?’ symbol to indicate that a failure to retrieve the label element for an object should be silently ignored, and improves usability if the set of MAC policies may change over time.


MAC library configuration file.


The following example configures user applications to operate with four MAC policies: mac_biba(4), mac_mls(4), SEBSD, and mac_partition(4).

# Default label set to be used by simple MAC applications 
default_labels file ?biba,?lomac,?mls,?sebsd 
default_labels ifnet ?biba,?lomac,?mls,?sebsd 
default_labels process ?biba,?lomac,?mls,?partition,?sebsd 
default_labels socket ?biba,?lomac,?mls 
# Deprecated (old) syntax 
default_file_labels ?biba,?mls,?sebsd 
default_ifnet_labels ?biba,?mls,?sebsd 
default_process_labels ?biba,?mls,partition,?sebsd

In this example, userland applications will attempt to retrieve Biba, MLS, and SEBSD labels for all object classes; for processes, they will additionally attempt to retrieve a Partition identifier. In all cases except the Partition identifier, failure to retrieve a label due to the respective policy not being present will be ignored.


Support for Mandatory Access Control was introduced in FreeBSD 5.0 as part of the TrustedBSD Project.


The TrustedBSD MAC Framework and associated policies, interfaces, and applications are considered to be an experimental feature in FreeBSD. Sites considering production deployment should keep the experimental status of these services in mind during any deployment process. See also mac(9) for related considerations regarding the kernel framework.
April 19, 2003 FreeBSD