On 9/23/20 2:48 PM, Vladimir Oltean wrote:
> On Wed, Sep 23, 2020 at 02:40:37PM -0700, Florian Fainelli wrote:
>> From: Vladimir Oltean <vladimir.olt...@nxp.com>
>> + /* The sad part about attempting to untag from DSA is that we
>> + * don't know, unless we check, if the skb will end up in
>> + * the bridge's data path - br_allowed_ingress() - or not.
>> + * For example, there might be an 8021q upper for the
>> + * default_pvid of the bridge, which will steal VLAN-tagged traffic
>> + * from the bridge's data path. This is a configuration that DSA
>> + * 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;
>> + }
>
> Argh...
> So I wanted to ask you how's performance with a few 8021q uppers, then I
> remembered that vlan_do_receive() probably does something more efficient
> here than a complete lookup, like hashing or something, then I found the
> vlan_find_dev() helper function.... Sorry for not noticing it in the
> first place.
Given the platforms I am using this is not even noticeable, but I did
not test with more than 10 uppers being added to the switch port.
Speaking of that part of the code, I was also wondering whether you
wanted this to be netdev_for_each_upper_dev_rcu(br, upper_dev, iter) and
catch a bridge device upper as opposed to a switch port upper? Either
way is fine and there are possibly use cases for either.
--
Florian
