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authorOliver Hartkopp <socketcan@hartkopp.net>2022-09-12 19:07:20 +0200
committerMarc Kleine-Budde <mkl@pengutronix.de>2022-09-15 09:08:08 +0200
commit467ef4c7b9d1c22ee64342804bf92549d765df14 (patch)
tree9d8fc4832f3658d85761bc85f2166b1731ded134 /include/linux/can
parent96a7457a14d9cf98cf58de1e26c03180e0f28141 (diff)
can: skb: add skb CAN frame data length helpers
Add two helpers to retrieve the data length from CAN sk_buffs and prepare the length information to be a uint16 value for the CAN XL support. Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/all/20220912170725.120748-3-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'include/linux/can')
-rw-r--r--include/linux/can/skb.h24
1 files changed, 23 insertions, 1 deletions
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index 27ebfc28510f..ddffc2fc008c 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -20,7 +20,8 @@ void can_flush_echo_skb(struct net_device *dev);
int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
unsigned int idx, unsigned int frame_len);
struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
- u8 *len_ptr, unsigned int *frame_len_ptr);
+ unsigned int *len_ptr,
+ unsigned int *frame_len_ptr);
unsigned int __must_check can_get_echo_skb(struct net_device *dev,
unsigned int idx,
unsigned int *frame_len_ptr);
@@ -113,4 +114,25 @@ static inline bool can_is_canfd_skb(const struct sk_buff *skb)
return (skb->len == CANFD_MTU && cfd->len <= CANFD_MAX_DLEN);
}
+/* get length element value from can[fd]_frame structure */
+static inline unsigned int can_skb_get_len_val(struct sk_buff *skb)
+{
+ const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ return cfd->len;
+}
+
+/* get needed data length inside CAN frame for all frame types (RTR aware) */
+static inline unsigned int can_skb_get_data_len(struct sk_buff *skb)
+{
+ unsigned int len = can_skb_get_len_val(skb);
+ const struct can_frame *cf = (struct can_frame *)skb->data;
+
+ /* RTR frames have an actual length of zero */
+ if (can_is_can_skb(skb) && cf->can_id & CAN_RTR_FLAG)
+ return 0;
+
+ return len;
+}
+
#endif /* !_CAN_SKB_H */