can: add ability to allocate CANFD frame in skb data

This patch adds the ability of allocating a CANFD frame data structure in the
skb data area.

Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 13a9098..cb584ea 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -521,6 +521,30 @@
 }
 EXPORT_SYMBOL_GPL(alloc_can_skb);
 
+struct sk_buff *alloc_canfd_skb(struct net_device *dev,
+				struct canfd_frame **cfd)
+{
+	struct sk_buff *skb;
+
+	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
+			       sizeof(struct canfd_frame));
+	if (unlikely(!skb))
+		return NULL;
+
+	skb->protocol = htons(ETH_P_CANFD);
+	skb->pkt_type = PACKET_BROADCAST;
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = dev->ifindex;
+
+	*cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame));
+	memset(*cfd, 0, sizeof(struct canfd_frame));
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_canfd_skb);
+
 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
 {
 	struct sk_buff *skb;