Re: [PATCH v2 net 2/4] bridge: Apply the PVID to priority-tagged frames

[Vlad Yasevich <vyasevic@redhat.com>]

On 10/16/2013 04:07 AM, Toshiaki Makita wrote:
> IEEE 802.1Q says that when we receive priority-tagged (VID 0) frames
> use the PVID for the port as its VID.
> (See IEEE 802.1Q-2011 6.9.1 and Table 9-2)
>
> Apply the PVID to not only untagged frames but also priority-tagged frames.
>
> Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>

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

> ---
>   net/bridge/br_vlan.c | 27 ++++++++++++++++++++-------
>   1 file changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
> index 21b6d21..5a9c44a 100644
> --- a/net/bridge/br_vlan.c
> +++ b/net/bridge/br_vlan.c
> @@ -189,6 +189,8 @@ out:
>   bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
>   			struct sk_buff *skb, u16 *vid)
>   {
> +	int err;
> +
>   	/* If VLAN filtering is disabled on the bridge, all packets are
>   	 * permitted.
>   	 */
> @@ -201,20 +203,31 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
>   	if (!v)
>   		return false;
>
> -	if (br_vlan_get_tag(skb, vid)) {
> +	err = br_vlan_get_tag(skb, vid);
> +	if (!*vid) {
>   		u16 pvid = br_get_pvid(v);
>
> -		/* Frame did not have a tag.  See if pvid is set
> -		 * on this port.  That tells us which vlan untagged
> -		 * traffic belongs to.
> +		/* Frame had a tag with VID 0 or did not have a tag.
> +		 * See if pvid is set on this port.  That tells us which
> +		 * vlan untagged or priority-tagged traffic belongs to.
>   		 */
>   		if (pvid == VLAN_N_VID)
>   			return false;
>
> -		/* PVID is set on this port.  Any untagged ingress
> -		 * frame is considered to belong to this vlan.
> +		/* PVID is set on this port.  Any untagged or priority-tagged
> +		 * ingress frame is considered to belong to this vlan.
>   		 */
> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
> +		if (likely(err))
> +			/* Untagged Frame. */
> +			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
> +		else
> +			/* Priority-tagged Frame.
> +			 * At this point, We know that skb->vlan_tci had
> +			 * VLAN_TAG_PRESENT bit and its VID field was 0x000.
> +			 * We update only VID field and preserve PCP field.
> +			 */
> +			skb->vlan_tci |= pvid;
> +
>   		return true;
>   	}
>
>