On 12.07.22 03:23, Vincent Mailhol wrote:
On Tue. 12 Jul. 2022 at 03:44, Oliver Hartkopp <socketcan@xxxxxxxxxxxx> wrote:
Enable the PF_CAN infrastructure to handle CAN XL frames. A new ethernet
protocol type ETH_P_CANXL is defined to tag skbuffs containing the CAN XL
frame data structure.
As the length information is now a uint16 value for CAN XL a new helper
function can_get_data_len() is introduced to retrieve the data length
from all types of CAN frames.
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
---
include/linux/can/skb.h | 14 ++++++++++
include/uapi/linux/if_ether.h | 1 +
net/can/af_can.c | 49 +++++++++++++++++++++++++++++------
3 files changed, 56 insertions(+), 8 deletions(-)
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index 182749e858b3..d043bc4afd6d 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -101,6 +101,20 @@ static inline bool can_is_canfd_skb(const struct sk_buff *skb)
{
/* the CAN specific type of skb is identified by its data length */
return skb->len == CANFD_MTU;
}
+/* get data length inside of CAN frame for all frame types */> +static inline unsigned int can_get_data_len(struct sk_buff *skb)
+{
+ if(skb->len == CANXL_MTU) {
+ const struct canxl_frame *cfx = (struct canxl_frame *)skb->data;
+
+ return cfx->len;
+ } else {
+ const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ return cfd->len;
+ }
+}
What about the RTR frames?
If there are cases in which we intentionally want the declared length
and not the actual length, it might be good to have two distinct
helper functions.
Good idea.
/* get data length inside of CAN frame for all frame types. For
* RTR frames, return zero. */
static inline unsigned int can_get_actual_len(struct sk_buff *skb)
I would name this one can_get_data_len()
{
const struct canxl_frame *cfx = (struct canxl_frame *)skb->data;
const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
if (skb->len == CANXL_MTU)
return cfx->len;
/* RTR frames have an actual length of zero */
if (skb->len == CAN_MTU && cfd->flags & CAN_RTR_FLAG)
return 0;
return cfd->len;
}
/* get data length inside of CAN frame for all frame types. For
* RTR frames, return requested length. */
static inline unsigned int can_get_declared_len(struct sk_buff *skb)
I would name this one can_get_len()
{
const struct canxl_frame *cfx = (struct canxl_frame *)skb->data;
const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
if (skb->len == CANXL_MTU)
return cfx->len;
return cfd->len;
}
Best regards,
Oliver
