Re: [PATCH v3 net-next] net-core: add rx_otherhost_dropped counter

[David Ahern]

On 3/8/22 2:25 PM, Jeffrey Ji wrote:
> diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
> index 95f7bb052784..8b87ea99904b 100644
> --- a/net/ipv4/ip_input.c
> +++ b/net/ipv4/ip_input.c
> @@ -451,6 +451,7 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
>  	 * that it receives, do not try to analyse it.
>  	 */
>  	if (skb->pkt_type == PACKET_OTHERHOST) {
> +		atomic_long_inc(&skb->dev->rx_otherhost_dropped);
>  		drop_reason = SKB_DROP_REASON_OTHERHOST;
>  		goto drop;
>  	}
> diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
> index 5b5ea35635f9..5624c937f87f 100644
> --- a/net/ipv6/ip6_input.c
> +++ b/net/ipv6/ip6_input.c
> @@ -150,6 +150,7 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev,
>  	struct inet6_dev *idev;
>  
>  	if (skb->pkt_type == PACKET_OTHERHOST) {
> +		atomic_long_inc(&skb->dev->rx_otherhost_dropped);
>  		kfree_skb(skb);
>  		return NULL;
>  	}

that's an expensive packet counter for a common path (e.g., hosting
environments).