From: Vladimir Oltean olteanv@gmail.com
[ Upstream commit b9cd75e6689560140dadaed98eb4b41aad75d55d ]
The switch driver keeps a "vid" variable per port, which signifies _the_ VLAN ID that is stripped on that port's egress (aka the native VLAN on a trunk port).
That is the way the hardware is designed (mostly). The port->vid is programmed into REW:PORT:PORT_VLAN_CFG:PORT_VID and the rewriter is told to send all traffic as tagged except the one having port->vid.
There exists a possibility of finer-grained egress untagging decisions: using the VCAP IS1 engine, one rule can be added to match every VLAN-tagged frame whose VLAN should be untagged, and set POP_CNT=1 as action. However, the IS1 can hold at most 512 entries, and the VLANs are in the order of 6 * 4096.
So the code is fine for now. But this sequence of commands:
$ bridge vlan add dev swp0 vid 1 pvid untagged $ bridge vlan add dev swp0 vid 2 untagged
makes untagged and pvid-tagged traffic be sent out of swp0 as tagged with VID 1, despite user's request.
Prevent that from happening. The user should temporarily remove the existing untagged VLAN (1 in this case), add it back as tagged, and then add the new untagged VLAN (2 in this case).
Cc: Antoine Tenart antoine.tenart@bootlin.com Cc: Alexandre Belloni alexandre.belloni@bootlin.com Fixes: 7142529f1688 ("net: mscc: ocelot: add VLAN filtering") Signed-off-by: Vladimir Oltean olteanv@gmail.com Reviewed-by: Florian Fainelli f.fainelli@gmail.com Acked-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mscc/ocelot.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c index 07ca3e0cdf92b..7ffe5959a7e73 100644 --- a/drivers/net/ethernet/mscc/ocelot.c +++ b/drivers/net/ethernet/mscc/ocelot.c @@ -260,8 +260,15 @@ static int ocelot_vlan_vid_add(struct net_device *dev, u16 vid, bool pvid, port->pvid = vid;
/* Untagged egress vlan clasification */ - if (untagged) + if (untagged && port->vid != vid) { + if (port->vid) { + dev_err(ocelot->dev, + "Port already has a native VLAN: %d\n", + port->vid); + return -EBUSY; + } port->vid = vid; + }
ocelot_vlan_port_apply(ocelot, port);