Allow the user to specify a physical interface through the $CANIF environment variable. Add a $BITRATE environment variable set with a default value of 500000. If $CANIF is omitted or if it starts with vcan (e.g. vcan1), the test will use the virtual can interface type. Otherwise, it will assume that the provided interface is a physical can interface. For example: CANIF=can1 BITRATE=1000000 ./test_raw_filter.sh will run set the can1 interface with a bitrate of one million and run the tests on it. Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>