platform_external_selinux/secilc/docs/cil_role_statements.md

Role Statements

role

Declares a role identifier in the current namespace.

Statement definition:

(role role_id)

Where:

role	The role keyword.
role_id	The role identifier.

Example:

This example declares two roles: object_r in the global namespace and unconfined.role:

(role object_r)

(block unconfined
    (role role)
)

roletype

Authorises a role to access a type identifier.

Statement definition:

(role role_id type_id)

Where:

roletype	The roletype keyword.
role_id	A single previously declared role or roleattribute identifier.
type_id	A single previously declared type, typealias or typeattribute identifier.

Example:

This example will declare role and type identifiers, then associate them:

(block unconfined
    (role role)
    (type process)
    (roletype role process)
)

roleattribute

Declares a role attribute identifier in the current namespace. The identifier may have zero or more role and roleattribute identifiers associated to it via the roleattributeset statement.

Statement definition:

(roleattribute roleattribute_id)

Where:

roleattribute	The roleattribute keyword.
roleattribute_id	The roleattribute identifier.

Example:

This example will declare a role attribute roles.role_holder that will have an empty set:

(block roles
    (roleattribute role_holder)
)

roleattributeset

Allows the association of one or more previously declared role identifiers to a roleattribute identifier. Expressions may be used to refine the associations as shown in the examples.

Statement definition:

(roleattributeset roleattribute_id (role_id ... | expr ...))

Where:

roleattributeset	The roleattributeset keyword.
roleattribute_id	A single previously declared roleattribute identifier.
role_id	Zero or more previously declared role or roleattribute identifiers. Note that there must be at least one role_id or expr parameter declared.
expr	Zero or more expr's, the valid operators and syntax are: (and (role_id ...) (role_id ...)) (or (role_id ...) (role_id ...)) (xor (role_id ...) (role_id ...)) (not (role_id ...)) (all)

Example:

This example will declare three roles and two role attributes, then associate all the roles to them as shown:

(block roles
    (role role_1)
    (role role_2)
    (role role_3)

    (roleattribute role_holder)
    (roleattributeset role_holder (role_1 role_2 role_3))

    (roleattribute role_holder_all)
    (roleattributeset role_holder_all (all))
)

roleallow

Authorise the current role to assume a new role.

Notes:

• May require a roletransition rule to ensure transition to the new role.

• This rule is not allowed in booleanif statements.

Statement definition:

(roleallow current_role_id new_role_id)

Where:

roleallow	The roleallow keyword.
current_role_id	A single previously declared role or roleattribute identifier.
new_role_id	A single previously declared role or roleattribute identifier.

Example:

See the roletransition statement for an example.

roletransition

Specify a role transition from the current role to a new role when computing a context for the target type. The class identifier would normally be process, however for kernel versions 2.6.39 with policy version >= 25 and above, any valid class may be used. Note that a roleallow rule must be used to authorise the transition.

Statement definition:

(roletransition current_role_id target_type_id class_id new_role_id)

Where:

roletransition	The roletransition keyword.
current_role_id	A single previously declared role or roleattribute identifier.
target_type_id	A single previously declared type, typealias or typeattribute identifier.
class_id	A single previously declared class or classmap identifier.
new_role_id	A single previously declared role identifier to be set on transition.

Example:

This example will authorise the unconfined.role to assume the msg_filter.role role, and then transition to that role:

(block ext_gateway
    (type process)
    (type exec)

    (roletype msg_filter.role process)
    (roleallow unconfined.role msg_filter.role)
    (roletransition unconfined.role exec process msg_filter.role)
)

rolebounds

Defines a hierarchical relationship between roles where the child role cannot have more privileges than the parent.

Notes:

• It is not possible to bind the parent role to more than one child role.

• While this is added to the binary policy, it is not enforced by the SELinux kernel services.

Statement definition:

(rolebounds parent_role_id child_role_id)

Where:

rolebounds	The rolebounds keyword.
parent_role_id	A single previously declared role identifier.
child_role_id	A single previously declared role identifier.

Example:

In this example the role test cannot have greater priviledges than unconfined.role:

(role test)

(unconfined
    (role role)
    (rolebounds role .test)
)