Mic security model call rule

call {source : <Sid>, target : <Sid>}

This verifies the permissibility of data streams from the target subject to the source subject.

It returns the "allowed" result in the following cases:

• The integrity level of the source subject does not exceed the integrity level of the target subject.
• The integrity level of the source subject exceeds the integrity level of the target subject, but the minimum integrity level of subjects and resources from which the source subject can receive data does not exceed the integrity level of the target subject.
• The integrity level of the source subject is incomparable to the integrity level of the target subject, but the minimum integrity level of subjects and resources from which the source subject can receive data does not exceed the integrity level of the target subject.

It returns the "denied" result in the following cases:

• The integrity level of the source subject exceeds the integrity level of the target subject, and the minimum integrity level of subjects and resources from which the source subject can receive data exceeds the integrity level of the target subject.
• The integrity level of the source subject exceeds the integrity level of the target subject, and the minimum integrity level of subjects and resources from which the source subject can read data is incomparable to the integrity level of the target subject.
• The integrity level of the source subject is incomparable to the integrity level of the target subject, and the minimum integrity level of subjects and resources from which the source subject can receive data exceeds the integrity level of the target subject.
• The integrity level of the source subject is incomparable to the integrity level of the target subject, and the minimum integrity level of subjects and resources from which the source subject can receive data is incomparable to the integrity level of the target subject.
• An integrity level was not assigned to the source subject or to the target subject.
• The source or target value is outside of the permissible range.

Example:

/* Any client in the solution is allowed to query

* any server (kernel) if data streams from

* the server (kernel) to the client are permitted by the

* Mic security model. Otherwise any client in the solution

* is prohibited from querying any server (kernel). */

request {

mic.call { source : src_sid

, target : dst_sid

}

}