Re: [PATCH net-next v1 1/1] net: bridge: ensure that link-local traffic cannot unlock a locked port

[Ido Schimmel <idosch@nvidia.com>]

On Thu, Jun 30, 2022 at 01:16:34PM +0200, Hans Schultz wrote:
> This patch is related to the patch set
> "Add support for locked bridge ports (for 802.1X)"
> Link: https://lore.kernel.org/netdev/20220223101650.1212814-1-schultz.hans+netdev@gmail.com/
> 
> This patch makes the locked port feature work with learning turned on,
> which is enabled with the command:
> 
> bridge link set dev DEV learning on
> 
> Without this patch, link local traffic (01:80:c2) like EAPOL packets will
> create a fdb entry when ingressing on a locked port with learning turned
> on, thus unintentionally opening up the port for traffic for the said MAC.
> 
> Some switchcore features like Mac-Auth and refreshing of FDB entries,
> require learning enables on some switchcores, f.ex. the mv88e6xxx family.
> Other features may apply too.
> 
> Since many switchcores trap or mirror various multicast packets to the
> CPU, link local traffic will unintentionally unlock the port for the
> SA mac in question unless prevented by this patch.

Why not just teach hostapd to do:

echo 1 > /sys/class/net/br0/bridge/no_linklocal_learn

?