found the missing consts in the original library

mcp2515_consts.h

@@ -4,6 +4,32 @@
 
 #include <stdint.h>
 
+/* special address description flags for the CAN_ID */
+#define CAN_EFF_FLAG 0x80000000UL /* EFF/SFF is set in the MSB */
+#define CAN_RTR_FLAG 0x40000000UL /* remote transmission request */
+#define CAN_ERR_FLAG 0x20000000UL /* error message frame */
+
+/* valid bits in CAN ID for frame formats */
+#define CAN_SFF_MASK 0x000007FFUL /* standard frame format (SFF) */
+#define CAN_EFF_MASK 0x1FFFFFFFUL /* extended frame format (EFF) */
+#define CAN_ERR_MASK 0x1FFFFFFFUL /* omit EFF, RTR, ERR flags */
+
+/*
+ * Controller Area Network Identifier structure
+ *
+ * bit 0-28 : CAN identifier (11/29 bit)
+ * bit 29   : error message frame flag (0 = data frame, 1 = error message)
+ * bit 30   : remote transmission request flag (1 = rtr frame)
+ * bit 31   : frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
+ */
+
+#define CAN_SFF_ID_BITS     11
+#define CAN_EFF_ID_BITS     29
+
+/* CAN payload length and DLC definitions according to ISO 11898-1 */
+#define CAN_MAX_DLC 8
+#define CAN_MAX_DLEN 8
+
 /*
  *  Speed 8M
  */