net: em_canid: Ematch rule to match CAN frames according to their identifiers

This ematch makes it possible to classify CAN frames (AF_CAN) according
to their identifiers. This functionality can not be easily achieved with
existing classifiers, such as u32, because CAN identifier is always stored
in native endianness, whereas u32 expects Network byte order.

Signed-off-by: Rostislav Lisovy <lisovy@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/include/linux/can.h b/include/linux/can.h
index 1a66cf61..018055e 100644
--- a/include/linux/can.h
+++ b/include/linux/can.h
@@ -38,6 +38,9 @@
  */
 typedef __u32 canid_t;
 
+#define CAN_SFF_ID_BITS		11
+#define CAN_EFF_ID_BITS		29
+
 /*
  * Controller Area Network Error Message Frame Mask structure
  *