MAC_BSDEXTENDED(4)					   BSD Kernel Interfaces Manual 					MAC_BSDEXTENDED(4)

NAME

     mac_bsdextended -- file system firewall policy

SYNOPSIS

     To compile the file system firewall policy into your kernel, place the following lines in your kernel configuration file:

	   options MAC
	   options MAC_BSDEXTENDED

     Alternately, to load the file system firewall policy module at boot time, place the following line in your kernel configuration file:

	   options MAC

     and in loader.conf(5):

	   mac_bsdextended_load="YES"

DESCRIPTION

     The mac_bsdextended security policy module provides an interface for the system administrator to impose mandatory rules regarding users and
     some system objects.  Rules are uploaded to the module (typically using ugidfw(8), or some other tool utilizing libugidfw(3)) where they are
     stored internally and used to determine whether to allow or deny specific accesses (see ugidfw(8)).

IMPLEMENTATION NOTES

     While the traditional mac(9) entry points are implemented, policy labels are not used; instead, access control decisions are made by iterat-
     ing through the internal list of rules until a rule which denies the particular access is found, or the end of the list is reached.  The
     mac_bsdextended policy works similar to ipfw(8) or by using a first match semantic.  This means that not all rules are applied, only the
     first matched rule; thus if Rule A allows access and Rule B blocks access, Rule B will never be applied.

   Sysctls
     The following sysctls may be used to tweak the behavior of mac_bsdextended:

     security.mac.bsdextended.enabled
	     Set to zero or one to toggle the policy off or on.

     security.mac.bsdextended.rule_count
	     List the number of defined rules, the maximum rule count is current set at 256.

     security.mac.bsdextended.rule_slots
	     List the number of rule slots currently being used.

     security.mac.bsdextended.firstmatch_enabled
	     Toggle between the old all rules match functionality and the new first rule matches functionality.  This is enabled by default.

     security.mac.bsdextended.logging
	     Log all access violations via the AUTHPRIV syslog(3) facility.

     security.mac.bsdextended.rules
	     Currently does nothing interesting.

SEE ALSO

     libugidfw(3), syslog(3), mac(4), mac_biba(4), mac_ifoff(4), mac_lomac(4), mac_mls(4), mac_none(4), mac_partition(4), mac_portacl(4),
     mac_seeotheruids(4), mac_test(4), ipfw(8), ugidfw(8), mac(9)

HISTORY

     The mac_bsdextended policy module first appeared in FreeBSD 5.0 and was developed by the TrustedBSD Project.

     The "match first case" and logging capabilities were later added by Tom Rhodes <trhodes@FreeBSD.org>.

AUTHORS

     This software was contributed to the FreeBSD Project by NAI Labs, the Security Research Division of Network Associates Inc. under
     DARPA/SPAWAR contract N66001-01-C-8035 (``CBOSS''), as part of the DARPA CHATS research program.

BSD
								   May 21, 2005 							       BSD