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.
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
---
drivers/net/can/dev/rx-offload.c | 2 +-
drivers/net/can/dev/skb.c | 12 ++++--------
include/linux/can/skb.h | 24 +++++++++++++++++++++++-
3 files changed, 28 insertions(+), 10 deletions(-)
diff --git a/drivers/net/can/dev/rx-offload.c b/drivers/net/can/dev/rx-offload.c
index a32a01c172d4..8505e547e922 100644
--- a/drivers/net/can/dev/rx-offload.c
+++ b/drivers/net/can/dev/rx-offload.c
@@ -245,11 +245,11 @@ unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
unsigned int *frame_len_ptr)
{
struct net_device *dev = offload->dev;
struct net_device_stats *stats = &dev->stats;
struct sk_buff *skb;
- u8 len;
+ unsigned int len;
int err;
skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr);
if (!skb)
return 0;
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 45313b90005c..7b369383416b 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -86,12 +86,12 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
return 0;
}
EXPORT_SYMBOL_GPL(can_put_echo_skb);
struct sk_buff *
-__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr,
- unsigned int *frame_len_ptr)
+__can_get_echo_skb(struct net_device *dev, unsigned int idx,
+ unsigned int *len_ptr, unsigned int *frame_len_ptr)
{
struct can_priv *priv = netdev_priv(dev);
if (idx >= priv->echo_skb_max) {
netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
@@ -103,17 +103,13 @@ __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr,
/* Using "struct canfd_frame::len" for the frame
* length is supported on both CAN and CANFD frames.
*/
struct sk_buff *skb = priv->echo_skb[idx];
struct can_skb_priv *can_skb_priv = can_skb_prv(skb);
- struct canfd_frame *cf = (struct canfd_frame *)skb->data;
/* get the real payload length for netdev statistics */
- if (cf->can_id & CAN_RTR_FLAG)
- *len_ptr = 0;
- else
- *len_ptr = cf->len;
+ *len_ptr = can_skb_get_data_len(skb);
if (frame_len_ptr)
*frame_len_ptr = can_skb_priv->frame_len;
priv->echo_skb[idx] = NULL;
@@ -139,11 +135,11 @@ __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr,
*/
unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx,
unsigned int *frame_len_ptr)
{
struct sk_buff *skb;
- u8 len;
+ unsigned int len;
skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr);
if (!skb)
return 0;
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
@@ -18,11 +18,12 @@
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);
void can_free_echo_skb(struct net_device *dev, unsigned int idx,
unsigned int *frame_len_ptr);
@@ -111,6 +112,27 @@ 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 && 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 */
--
2.30.2
