send_origin_headers() WordPress Function

function send_origin_headers() {
	$origin = get_http_origin();

	if ( is_allowed_http_origin( $origin ) ) {
		header( 'Access-Control-Allow-Origin: ' . $origin );
		header( 'Access-Control-Allow-Credentials: true' );
		if ( 'OPTIONS' === $_SERVER['REQUEST_METHOD'] ) {
			exit;
		}
		return $origin;
	}

	if ( 'OPTIONS' === $_SERVER['REQUEST_METHOD'] ) {
		status_header( 403 );
		exit;
	}

	return false;
}
Uses	Description
wp-includes/functions.php:status_header()	Set HTTP status header.
wp-includes/http.php:is_allowed_http_origin()	Determines if the HTTP origin is an authorized one.
wp-includes/http.php:get_http_origin()	Get the HTTP Origin of the current request.