canfd: add new data structures and constants
- add new struct canfd_frame
- check identical element offsets in struct can_frame and struct canfd_frame
- new ETH_P_CANFD definition to tag CAN FD skbs correctly
- add CAN_MTU and CANFD_MTU definitions for easy frame and mode detection
- add CAN[FD]_MAX_[DLC|DLEN] helper constants to remove hard coded values
- update existing struct can_frame with helper constants and comments
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 6efcd37..c96140a 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -41,6 +41,7 @@
*/
#include <linux/module.h>
+#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/slab.h>
@@ -824,6 +825,12 @@
static __init int can_init(void)
{
+ /* check for correct padding to be able to use the structs similarly */
+ BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
+ offsetof(struct canfd_frame, len) ||
+ offsetof(struct can_frame, data) !=
+ offsetof(struct canfd_frame, data));
+
printk(banner);
memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));