Commit 1574481b authored by Oliver Hartkopp's avatar Oliver Hartkopp Committed by Marc Kleine-Budde
Browse files

vxcan: remove sk reference in peer skb 

With can_create_echo_skb() the skb which is forwarded to the peer CAN
interface shares the sk pointer from the originating socket.
This makes the CAN frame show up in the peer namespace as a TX packet.

With the use of skb_clone() analogue to the handling in gw.c the peer
skb gets a new start in the peer namespace and correctly appears as
a RX packet.

Link: https://lore.kernel.org/all/20220309120416.83514-4-socketcan@hartkopp.net


Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 9c0c191d

drivers/net/can/vxcan.c

+11 −6
Original line number Original line Diff line number Diff line
@@ -33,28 +33,33 @@ struct vxcan_priv { 
	struct net_device __rcu	*peer;

	struct net_device __rcu	*peer;

};

};





static netdev_tx_t vxcan_xmit(struct sk_buff *skb, struct net_device *dev)

static netdev_tx_t vxcan_xmit(struct sk_buff *oskb, struct net_device *dev)

{

{

	struct vxcan_priv *priv = netdev_priv(dev);

	struct vxcan_priv *priv = netdev_priv(dev);

	struct net_device *peer;

	struct net_device *peer;

	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;

	struct canfd_frame *cfd = (struct canfd_frame *)oskb->data;

	struct net_device_stats *peerstats, *srcstats = &dev->stats;

	struct net_device_stats *peerstats, *srcstats = &dev->stats;

	struct sk_buff *skb;

	u8 len;

	u8 len;





	if (can_dropped_invalid_skb(dev, skb))

	if (can_dropped_invalid_skb(dev, oskb))

		return NETDEV_TX_OK;

		return NETDEV_TX_OK;





	rcu_read_lock();

	rcu_read_lock();

	peer = rcu_dereference(priv->peer);

	peer = rcu_dereference(priv->peer);

	if (unlikely(!peer)) {

	if (unlikely(!peer)) {

		kfree_skb(skb);

		kfree_skb(oskb);

		dev->stats.tx_dropped++;

		dev->stats.tx_dropped++;

		goto out_unlock;

		goto out_unlock;

	}

	}





	skb = can_create_echo_skb(skb);

	skb = skb_clone(oskb, GFP_ATOMIC);

	if (!skb)

	if (skb) {

		consume_skb(oskb);

	} else {

		kfree(oskb);

		goto out_unlock;

		goto out_unlock;

	}





	/* reset CAN GW hop counter */

	/* reset CAN GW hop counter */

	skb->csum_start = 0;

	skb->csum_start = 0;