lkml.org 
[lkml]   [2020]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH net-next v3 1/2] net: dsa: untag the bridge pvid from rx skbs
From
Date
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.oltean@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

\
 
 \ /
  Last update: 2020-09-23 23:51    [W:0.085 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site