On 25/10/2022 13:00, Ido Schimmel wrote:

From: "Hans J. Schultz" <redacted>

When the bridge is offloaded to hardware, FDB entries are learned and
aged-out by the hardware. Some device drivers synchronize the hardware
and software FDBs by generating switchdev events towards the bridge.

When a port is locked, the hardware must not learn autonomously, as
otherwise any host will blindly gain authorization. Instead, the
hardware should generate events regarding hosts that are trying to gain
authorization and their MAC addresses should be notified by the device
driver as locked FDB entries towards the bridge driver.

Allow device drivers to notify the bridge driver about such entries by
extending the 'switchdev_notifier_fdb_info' structure with the 'locked'
bit. The bit can only be set by device drivers and not by the bridge
driver.

Prevent a locked entry from being installed if MAB is not enabled on the
bridge port. By placing this check in the bridge driver we avoid the
need to reflect the 'BR_PORT_MAB' flag to device drivers.

If an entry already exists in the bridge driver, reject the locked entry
if the current entry does not have the "locked" flag set or if it points
to a different port. The same semantics are implemented in the software
data path.

Signed-off-by: Hans J. Schultz <redacted>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---

Notes:
    Changes made by me:
    
     * Reword commit message.
     * Forbid locked entries when MAB is not enabled.
     * Forbid roaming of locked entries.
     * Avoid setting 'locked' bit towards device drivers.

 include/net/switchdev.h   |  1 +
 net/bridge/br.c           |  3 ++-
 net/bridge/br_fdb.c       | 22 ++++++++++++++++++++--
 net/bridge/br_private.h   |  2 +-
 net/bridge/br_switchdev.c |  1 +
 5 files changed, 25 insertions(+), 4 deletions(-)

Acked-by: Nikolay Aleksandrov <razor@blackwall.org>