RefpolicyBasicRoleCreation

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Roles in Reference Policy

Reference policy consists of several user roles for typical system operation. Rules for each role are contained in individual Reference Policy modules, which allow flexibility in role separation.

Role Module Description
user_runprivuserBasic user role. This role can do most things a non UID 0 linux user can do.
staff_rstaffAdministrator's unprivileged user role. This role is basically the same as user_r, but is meant for administrators.
sysadm_rsysadmGeneral system administration role.
secadm_rsecadmSecurity administrator role. Administrates security policy.
auditadm_rauditadmAudit system and audit log administration role. Configures the auditing policy and manages audit logs.
logadm_rlogadmSyslog administration role. Configures syslog and manages system logs.
webadm_rwebadmWeb server administration role. Configures Apache and can optionally manage user web content.
guest_rguestHighly confined user. No X windows support.
xguest_rxguestHighly confined X windows user.
unconfined_runconfinedThis role is not confined by SELinux except by memory protections (for example executable memory protections).

This guide will discuss creation of new roles when these roles do not meet needs.

Creating the Policy for the New Role

This section of the guide discusses the creation of the policy for the roles. These statements should be added to a policy module. See GettingStarted for more information on creating policy modules.

There are several methods for creating roles in Reference Policy. It is best to use Reference Policy templates, as there are several requirements for a user to log in, but they are beyond the scope of this guide.

Roles Similar to Existing Roles

If the role's user domain should be similar to user_r or staff_r, the userdom_unpriv_user_template() template should be used.

userdom_unpriv_user_template(myrole)

If the role's user domain should be similar to sysadm_r, the userdom_admin_user_template() template should be used.

userdom_admin_user_template(myrole)

These both will create role myrole_r and user domain myrole_t. Then rules can subsequently be added to myrole_t to customize it.

Configuring Userland Programs for the New Role

Default Type

The default_type file configure SELinux-aware programs behavior when constructing a context. When the program only is provided with a role, the domain for the new context is selected based on this file. Typically this file is only used by the newrole program. Add the new role:domain combination to the end of this file.

sysadm_r:sysadm_t
staff_r:staff_t
unconfined_r:unconfined_t
user_r:user_t
myrole_r:myrole_t

Default Contexts

The default_contexts files configure SELinux-aware programs behavior when selecting a context for a user. Typically this is used when logging in, but there are a few other uses.

Add the new role and user domain to services where login is desired. For example, the local_login_t is for local logins, whereas xdm_t is for logins via a X display manager, such as GDM or KDM.

system_r:local_login_t	user_r:user_t myrole_r:myrole_t staff_r:staff_t sysadm_r:sysadm_t unconfined_r:unconfined_t
system_r:remote_login_t	user_r:user_t staff_r:staff_t unconfined_r:unconfined_t
system_r:sshd_t		user_r:user_t staff_r:staff_t sysadm_r:sysadm_t unconfined_r:unconfined_t
system_r:xdm_t		user_r:user_t myrole_r:myrole_t staff_r:staff_t sysadm_r:sysadm_t unconfined_r:unconfined_t

For each service, the order matters. The service will test to see which role:domain combination is valid for the user logging in, and use the first available choice (left to right). So if the SELinux user is allowed user_r and myrole_r, the default will be user_r:user_t when logging in.

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