Re: [PATCH net 2/2] bridge: Fix handling stacked vlan tags

[Vlad Yasevich <vyasevic@redhat.com>]

On 03/27/2014 08:46 AM, Toshiaki Makita wrote:
> If a bridge with vlan_filtering enabled receives frames with stacked
> vlan tags, i.e., they have two vlan tags, br_vlan_untag() strips not
> only the outer tag but also the inner tag.
> 
> br_vlan_untag() is called only from br_handle_vlan(), and in this case,
> it is enough to set skb->vlan_tci to 0 here, because vlan_tci has already
> been set before calling br_handle_vlan().
> 
> Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>

Acked-by: Vlad Yasevich <vyasevic@redhat.com>

-vlad

> ---
>  net/bridge/br_vlan.c | 18 +-----------------
>  1 file changed, 1 insertion(+), 17 deletions(-)
> 
> diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
> index 44f31af..c77eed5 100644
> --- a/net/bridge/br_vlan.c
> +++ b/net/bridge/br_vlan.c
> @@ -119,22 +119,6 @@ static void __vlan_flush(struct net_port_vlans *v)
>  	kfree_rcu(v, rcu);
>  }
>  
> -/* Strip the tag from the packet.  Will return skb with tci set 0.  */
> -static struct sk_buff *br_vlan_untag(struct sk_buff *skb)
> -{
> -	if (skb->protocol != htons(ETH_P_8021Q)) {
> -		skb->vlan_tci = 0;
> -		return skb;
> -	}
> -
> -	skb->vlan_tci = 0;
> -	skb = vlan_untag(skb);
> -	if (skb)
> -		skb->vlan_tci = 0;
> -
> -	return skb;
> -}
> -
>  struct sk_buff *br_handle_vlan(struct net_bridge *br,
>  			       const struct net_port_vlans *pv,
>  			       struct sk_buff *skb)
> @@ -150,7 +134,7 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br,
>  	 */
>  	br_vlan_get_tag(skb, &vid);
>  	if (test_bit(vid, pv->untagged_bitmap))
> -		skb = br_vlan_untag(skb);
> +		skb->vlan_tci = 0;
>  
>  out:
>  	return skb;
>