Re: [PATCH v5 net-next 12/14] bridge: No DEV_PATH_BR_VLAN_UNTAG_HW for dsa foreign
From: Vladimir Oltean <olteanv@gmail.com>
Date: 2025-02-07 15:03:48
Also in:
bridge, linux-arm-kernel, linux-mediatek, lkml, netfilter-devel
On Tue, Feb 04, 2025 at 08:49:19PM +0100, Eric Woudstra wrote:
In network setup as below:
fastpath bypass
.----------------------------------------.
/ \
| IP - forwarding |
| / \ v
| / wan ...
| /
| |
| |
| brlan.1
| |
| +-------------------------------+
| | vlan 1 |
| | |
| | brlan (vlan-filtering) |
| | +---------------+
| | | DSA-SWITCH |
| | vlan 1 | |
| | to | |
| | untagged 1 vlan 1 |
| +---------------+---------------+
. / \
----->wlan1 lan0
. .
. ^
^ vlan 1 tagged packets
untagged packets
br_vlan_fill_forward_path_mode() sets DEV_PATH_BR_VLAN_UNTAG_HW when
filling in from brlan.1 towards wlan1. But it should be set to
DEV_PATH_BR_VLAN_UNTAG in this case. Using BR_VLFLAG_ADDED_BY_SWITCHDEV
is not correct. The dsa switchdev adds it as a foreign port.
The same problem for all foreignly added dsa vlans on the bridge.
First add the vlan, trying only native devices.
If this fails, we know this may be a vlan from a foreign device.
Use BR_VLFLAG_TAGGING_BY_SWITCHDEV to make sure DEV_PATH_BR_VLAN_UNTAG_HW
is set only when there if no foreign device involved.
Signed-off-by: Eric Woudstra <redacted>
---Shouldn't mlxsw_sp_switchdev_vxlan_vlans_add() also respect the SWITCHDEV_F_NO_FOREIGN flag? My (maybe incorrect) understanding of bridging topologies with vxlan and mlxsw is that they are neighbor bridge ports, and mlxsw doesn't (seem to) call switchdev_bridge_port_offload() for the vxlan bridge port. This technically makes vxlan a foreign bridge port to mlxsw, so it should skip reacting on VLAN switchdev objects when that flag is set, just for uniform behavior across the board. (your patch repeats the notifier without the SWITCHDEV_F_NO_FOREIGN flag anyway, so it only matters for flowtable offload).