Combine garlic, onion, celery salt, and salt; rub mixture over duckling. Roll duckling quarters in flour; place skin side up in a 13- x 9- x 2-inch baking dish. Spoon cranberry sauce on top; cover and bake at 325° for 2 1/2 hours or until tender. Remove duckling from baking dish; drain well, and transfer to serving platter. Serve with cranberry sauce.