There are two components to the policy, the binary tree and the
source tree. The binary tree comes from the selinux-policy-<policyname> package and supplies
the binary policy file. Alternately, the binary policy can be built
from source when the selinux-policy-<policyname>-sources
package is installed. For Red Hat Enterprise Linux 4 the
<policyname> is targeted.
Directory conventions for this guide are explained in Section 3 Conventions for SELinux
Directories and Files.
-
/etc/selinux/targeted/ — this is
the root folder for the targeted policy, and contains both the
binary and source trees.
-
/etc/selinux/targeted/policy/ —
the binary policy file policy.<XY> is here. In this guide, the
variable $SELINUX_POLICY/ is used for this directory.
-
/etc/selinux/targeted/src/policy/
— this is the location of the policy source tree. For details
about these sub-directories, read Section 3.2 Files and Directories
of the Targeted Policy. In this guide, the variable
$SELINUX_SRC/ is used for this directory.
-
/etc/selinux/targeted/contexts/
— location of the security context information and
configuration files, which are used during runtime by various
applications. This directory contains:
-
*_context* and default_type — various contexts used by
applications, such as the userhelper_context used by userhelper.
-
files/* — the file file_contexts contains the default contexts for the
whole file system. This is what restorecon
references when relabeling. The file media contains the default contexts for media
devices such as the CD-ROM and floppy disk.
-
users/* — in the targeted
policy, only the file root is in this
directory. These files are used for determining context on login,
which is system_r:unconfined_t
for root.
-
booleans — this is where the
runtime Booleans are configured. This is the canonical
configuration file when Boolean values are changed.
To help applications that need the various SELinux paths,
libselinux has a number of functions that
return the paths to the different configuration files and
directories. This keeps applications from having to hard code the
paths, especially since the active policy location is dependent on
the setting in /etc/selinux/config. The
list of functions is available from the manual page which you can
view with the command man 3
selinux_binary_policy_path.
