On Thu, Oct 01, 2020 at 07:42:15PM -0700, Florian Fainelli wrote:
> Now that we are guaranteed that dsa_untag_bridge_pvid() is called after
> eth_type_trans() we can utilize __vlan_find_dev_deep_rcu() which will
> take care of finding an 802.1Q upper on top of a bridge master.
>
> A common use case, prior to 12a1526d067 ("net: dsa: untag the bridge
> pvid from rx skbs") was to configure a bridge 802.1Q upper like this:
>
> ip link add name br0 type bridge vlan_filtering 0
> ip link add link br0 name br0.1 type vlan id 1
>
> in order to pop the default_pvid VLAN tag.
>
> With this change we restore that behavior while still allowing the DSA
> receive path to automatically pop the VLAN tag.
>
> Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
> ---
Reviewed-by: Vladimir Oltean <vladimir.olt...@nxp.com>
> net/dsa/dsa_priv.h | 11 +++--------
> 1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
> index d6ce8c2a2590..12998bf04e55 100644
> --- a/net/dsa/dsa_priv.h
> +++ b/net/dsa/dsa_priv.h
> @@ -204,7 +204,6 @@ static inline struct sk_buff
> *dsa_untag_bridge_pvid(struct sk_buff *skb)
> struct net_device *br = dp->bridge_dev;
> struct net_device *dev = skb->dev;
> struct net_device *upper_dev;
> - struct list_head *iter;
> u16 vid, pvid, proto;
> int err;
>
> @@ -246,13 +245,9 @@ static inline struct sk_buff
> *dsa_untag_bridge_pvid(struct sk_buff *skb)
> * supports because vlan_filtering is 0. In that case, we should
> * definitely keep the tag, to make sure it keeps working.
> */
> - netdev_for_each_upper_dev_rcu(dev, upper_dev, iter) {
> - if (!is_vlan_dev(upper_dev))
> - continue;
> -
> - if (vid == vlan_dev_vlan_id(upper_dev))
> - return skb;
> - }
> + upper_dev = __vlan_find_dev_deep_rcu(br, htons(proto), vid);
> + if (upper_dev)
> + return skb;
>
> __vlan_hwaccel_clear_tag(skb);
>
> --
> 2.25.1
>
