[PATCH net-next 22/23] can: dev: add CAN XL support to virtual CAN

[Marc Kleine-Budde <mkl@pengutronix.de>]

From: Oliver Hartkopp <socketcan@hartkopp.net>

Make use of new can_skb_get_data_len() helper.
Add support for variable CANXL MTU using the new can_is_canxl_dev_mtu().

Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-7-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/vcan.c  | 12 ++++++------
 drivers/net/can/vxcan.c |  8 ++++----
 include/linux/can/dev.h |  5 +++++
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/net/can/vcan.c b/drivers/net/can/vcan.c
index 36b6310a2e5b..285635c23443 100644
--- a/drivers/net/can/vcan.c
+++ b/drivers/net/can/vcan.c
@@ -71,11 +71,10 @@ MODULE_PARM_DESC(echo, "Echo sent frames (for testing). Default: 0 (Off)");
 
 static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
 {
-	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 	struct net_device_stats *stats = &dev->stats;
 
 	stats->rx_packets++;
-	stats->rx_bytes += cfd->len;
+	stats->rx_bytes += can_skb_get_data_len(skb);
 
 	skb->pkt_type  = PACKET_BROADCAST;
 	skb->dev       = dev;
@@ -86,14 +85,14 @@ static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
 
 static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
 {
-	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 	struct net_device_stats *stats = &dev->stats;
-	int loop, len;
+	unsigned int len;
+	int loop;
 
 	if (can_dropped_invalid_skb(dev, skb))
 		return NETDEV_TX_OK;
 
-	len = cfd->can_id & CAN_RTR_FLAG ? 0 : cfd->len;
+	len = can_skb_get_data_len(skb);
 	stats->tx_packets++;
 	stats->tx_bytes += len;
 
@@ -137,7 +136,8 @@ static int vcan_change_mtu(struct net_device *dev, int new_mtu)
 	if (dev->flags & IFF_UP)
 		return -EBUSY;
 
-	if (new_mtu != CAN_MTU && new_mtu != CANFD_MTU)
+	if (new_mtu != CAN_MTU && new_mtu != CANFD_MTU &&
+	    !can_is_canxl_dev_mtu(new_mtu))
 		return -EINVAL;
 
 	dev->mtu = new_mtu;
diff --git a/drivers/net/can/vxcan.c b/drivers/net/can/vxcan.c
index cffd107d8b28..26a472d2ea58 100644
--- a/drivers/net/can/vxcan.c
+++ b/drivers/net/can/vxcan.c
@@ -38,10 +38,9 @@ static netdev_tx_t vxcan_xmit(struct sk_buff *oskb, struct net_device *dev)
 {
 	struct vxcan_priv *priv = netdev_priv(dev);
 	struct net_device *peer;
-	struct canfd_frame *cfd = (struct canfd_frame *)oskb->data;
 	struct net_device_stats *peerstats, *srcstats = &dev->stats;
 	struct sk_buff *skb;
-	u8 len;
+	unsigned int len;
 
 	if (can_dropped_invalid_skb(dev, oskb))
 		return NETDEV_TX_OK;
@@ -70,7 +69,7 @@ static netdev_tx_t vxcan_xmit(struct sk_buff *oskb, struct net_device *dev)
 	skb->dev        = peer;
 	skb->ip_summed  = CHECKSUM_UNNECESSARY;
 
-	len = cfd->can_id & CAN_RTR_FLAG ? 0 : cfd->len;
+	len = can_skb_get_data_len(skb);
 	if (netif_rx(skb) == NET_RX_SUCCESS) {
 		srcstats->tx_packets++;
 		srcstats->tx_bytes += len;
@@ -132,7 +131,8 @@ static int vxcan_change_mtu(struct net_device *dev, int new_mtu)
 	if (dev->flags & IFF_UP)
 		return -EBUSY;
 
-	if (new_mtu != CAN_MTU && new_mtu != CANFD_MTU)
+	if (new_mtu != CAN_MTU && new_mtu != CANFD_MTU &&
+	    !can_is_canxl_dev_mtu(new_mtu))
 		return -EINVAL;
 
 	dev->mtu = new_mtu;
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index c3e50e537e39..58f5431a5559 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -147,6 +147,11 @@ static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
 	return priv->ctrlmode & ~priv->ctrlmode_supported;
 }
 
+static inline bool can_is_canxl_dev_mtu(unsigned int mtu)
+{
+	return (mtu >= CANXL_MIN_MTU && mtu <= CANXL_MAX_MTU);
+}
+
 void can_setup(struct net_device *dev);
 
 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
-- 
2.35.1