set_security

Arguments

Returns

The previous security level for this process.

Description

This function changes the security level for the current process to the given value. There is no restriction on the security level argument. A low-security process can alter its own security level to be higher.

If it is necessary to have a process's security level to be unalterable, then the set_security function can be re-bound after the security level is originally set (see second example). The only use of security level is in conjunction with the Cascade DataHub.

Example

    Gamma> init_ipc("spt","spq");
    t
    Gamma> secure_point(#d,5);
    nil
    Gamma> set_security(9);
    0
    Gamma> secure_point(#d,5);
    t
    Gamma> secure_point(#d,12);
    nil
    Gamma> set_security(15);
    9
    Gamma> secure_point(#d,12);
    t
    Gamma> 

The example below sets the current process's security to 5, and then re-binds set_security so that the program can no longer alter its security. The list function is used in the re-binding, as it will accept any number of arguments without error, and will have no side-effects.

    Gamma> set_security(5);
    0
    Gamma> set_security = list;
    (defun list (&optional &rest s_exp...) ...)
    Gamma> set_security(9);
    (9)
    Gamma> secure_point(#g,10);
    nil
    Gamma> secure_point(#g,6);
    nil
    Gamma> secure_point(#g,4);
    t
    Gamma> 
    		

See Also

point_security, secure_point