Re: [PATCH net-next v24 16/23] ovpn: implement keepalive mechanism

[Sabrina Dubroca]

2025-03-18, 02:40:51 +0100, Antonio Quartulli wrote:
> @@ -124,6 +154,13 @@ void ovpn_decrypt_post(void *data, int ret)
>  			goto drop;
>  		}
>  
> +		if (ovpn_is_keepalive(skb)) {
> +			net_dbg_ratelimited("%s: ping received from peer %u\n",
> +					    netdev_name(peer->ovpn->dev),
> +					    peer->id);
> +			goto drop_nocount;
> +		}
> +
>  		net_info_ratelimited("%s: unsupported protocol received from peer %u\n",
>  				     netdev_name(peer->ovpn->dev), peer->id);
>  		goto drop;
> @@ -149,6 +186,7 @@ void ovpn_decrypt_post(void *data, int ret)
>  drop:
>  	if (unlikely(skb))
>  		dev_core_stats_rx_dropped_inc(peer->ovpn->dev);
> +drop_nocount:
>  	if (likely(peer))
>  		ovpn_peer_put(peer);
>  	if (likely(ks))
>  	kfree_skb(skb);
>  }

Again a small thing: in the case of a keepalive message, it would also
be nice to use consume_skb instead of kfree_skb. Quoting from the doc
for consume_skb:

 *	Functions identically to kfree_skb, but kfree_skb assumes that the frame
 *	is being dropped after a failure and notes that



Something like this maybe (not compiled):

	/* skb is passed to upper layer - don't free it */
	skb = NULL;
drop:
	if (unlikely(skb))
		dev_core_stats_rx_dropped_inc(peer->ovpn->dev);
	kfree_skb(skb);
	skb = NULL;
drop_nocount:
	if (likely(peer))
		ovpn_peer_put(peer);
	if (likely(ks))
		ovpn_crypto_key_slot_put(ks);
	consume_skb(skb);



-- 
Sabrina