can: preserve skbuff protocol in can_put_echo_skb

The skbuff protocol value was formerly fixed/sanitized to ETH_P_CAN in
can_put_echo_skb(). With CAN FD this value has to be preserved.
This patch changes the hard assignment of the protocol value to a check of
valid protocol values for CAN and CAN FD.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index c0563f1..e1a3741 100644 (file)
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -317,7 +317,9 @@ void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
        BUG_ON(idx >= priv->echo_skb_max);
 
        /* check flag whether this packet has to be looped back */
-       if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) {
+       if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
+           (skb->protocol != htons(ETH_P_CAN) &&
+            skb->protocol != htons(ETH_P_CANFD))) {
                kfree_skb(skb);
                return;
        }
@@ -329,7 +331,6 @@ void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
                        return;
 
                /* make settings for echo to reduce code in irq context */
-               skb->protocol = htons(ETH_P_CAN);
                skb->pkt_type = PACKET_BROADCAST;
                skb->ip_summed = CHECKSUM_UNNECESSARY;
                skb->dev = dev;