Re: [PATCH net-next 1/4] net: dsa: Call dsa_untag_bridge_pvid() from dsa_switch_rcv()

[Vladimir Oltean <vladimir.oltean@nxp.com>]

On Thu, Oct 01, 2020 at 07:42:12PM -0700, Florian Fainelli wrote:
> When a DSA switch driver needs to call dsa_untag_bridge_pvid(), it can
> set dsa_switch::untag_brige_pvid to indicate this is necessary.
> 
> This is a pre-requisite to making sure that we are always calling
> dsa_untag_bridge_pvid() after eth_type_trans() has been called.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---

Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>

>  include/net/dsa.h | 8 ++++++++
>  net/dsa/dsa.c     | 9 +++++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index b502a63d196e..8b0696e08cac 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -308,6 +308,14 @@ struct dsa_switch {
>  	 */
>  	bool			configure_vlan_while_not_filtering;
>  
> +	/* If the switch driver always programs the CPU port as egress tagged
> +	 * despite the VLAN configuration indicating otherwise, then setting
> +	 * @untag_bridge_pvid will force the DSA receive path to pop the bridge's
> +	 * default_pvid VLAN tagged frames to offer a consistent behavior
> +	 * between a vlan_filtering=0 and vlan_filtering=1 bridge device.
> +	 */
> +	bool			untag_bridge_pvid;
> +
>  	/* In case vlan_filtering_is_global is set, the VLAN awareness state
>  	 * should be retrieved from here and not from the per-port settings.
>  	 */
> diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
> index 5c18c0214aac..dec4ab59b7c4 100644
> --- a/net/dsa/dsa.c
> +++ b/net/dsa/dsa.c
> @@ -225,6 +225,15 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
>  	skb->pkt_type = PACKET_HOST;
>  	skb->protocol = eth_type_trans(skb, skb->dev);
>  
> +	if (unlikely(cpu_dp->ds->untag_bridge_pvid)) {
> +		nskb = dsa_untag_bridge_pvid(skb);
> +		if (!nskb) {
> +			kfree_skb(skb);
> +			return 0;
> +		}
> +		skb = nskb;
> +	}
> +
>  	s = this_cpu_ptr(p->stats64);
>  	u64_stats_update_begin(&s->syncp);
>  	s->rx_packets++;
> -- 
> 2.25.1
>