Subject: Re: [PATCH 2/2] SOCK: add raw6 drops counter

From: Eric Dumazet <[email-masked]>
Date: Wed, 14 Nov 2007 06:48:27 +0100

Wang Chen a écrit :
> Add raw drops counter for IPv6 in /proc/net/raw6 .
> 
> Signed-off-by: Wang Chen <[email-masked]>
> ---
>  raw.c |   15 ++++++++-------
>  1 files changed, 8 insertions(+), 7 deletions(-)
> 
> diff -Nurp linux-2.6.24-rc2.org/net/ipv6/raw.c linux-2.6.24-rc2/net/ipv6/raw.c
> --- linux-2.6.24-rc2.org/net/ipv6/raw.c	2007-11-09 16:38:05.000000000 +0800
> +++ linux-2.6.24-rc2/net/ipv6/raw.c	2007-11-14 09:46:54.000000000 +0800
> @@ -354,14 +354,14 @@ static inline int rawv6_rcv_skb(struct s
>  {
>  	if ((raw6_sk(sk)->checksum || sk->sk_filter) &&
>  	    skb_checksum_complete(skb)) {
> -		/* FIXME: increment a raw6 drops counter here */
> +		atomic_inc(&sk->sk_drops);	

I am not sure the comment was refering to a per socket counter here.

If the frame checksum is bad, we can not be sure the socket is OK, since the 
garbaged bits could be in the tuple that identify the socket.

Maybe here we want to increment a global raw6 drop counter (well, for the 
given ipv6 instance)

>  		kfree_skb(skb);
>  		return 0;
>  	}
>  
>  	/* Charge it to the socket. */
>  	if (sock_queue_rcv_skb(sk,skb)<0) {
> -		/* FIXME: increment a raw6 drops counter here */
> +		atomic_inc(&sk->sk_drops);
>  		kfree_skb(skb);
>  		return 0;
>  	}
> @@ -382,6 +382,7 @@ int rawv6_rcv(struct sock *sk, struct sk
>  	struct raw6_sock *rp = raw6_sk(sk);
>  
>  	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
> +		atomic_inc(&sk->sk_drops);
>  		kfree_skb(skb);
>  		return NET_RX_DROP;
>  	}
> @@ -405,7 +406,7 @@ int rawv6_rcv(struct sock *sk, struct sk
>  
>  	if (inet->hdrincl) {
>  		if (skb_checksum_complete(skb)) {
> -			/* FIXME: increment a raw6 drops counter here */
> +			atomic_inc(&sk->sk_drops);

Same remark here.