During the time that as an officer or enlisted person of the California National Guard, who is on full-time active duty in the military service of the state, and is engaged, with the approval of the Adjutant General, in the military service of the state in attendance at drills, camps, or special exercises, sponsored by federal authority or by the United States Department of Defense, as a member of the National Guard of the United States, he or she shall receive salary, pay, and compensation as provided in Sections 320 and 321.