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.