A2.1 Les requêtes de contrôle

request <<request-name>> {
   type:              control;
   input:             <name>::<sdi-ref>;
   output:            <name>::<sdi-ref>;
   c_control_func:    <codel>;
   fail_msg:          <msg-name>, ...;
   incompatible_with: <exec-rqst-name>, ...;
}