net/mlx5e: Fail attempt to offload e-switch TC encap flows with vlan on underlay

Currently we don't support nor fail attempts to offload encap flows routed
to vlan device on the underlay network. We wrongly consider a vlan underlay
device to be on the same e-switch b/c the switchdev ID is retrieved recursively.

Add explicit check for that and fail such attempts.

Also align to a more strict check for the ingress and the underlay devices
to practically be on the same eswitch.

Fixes: ce99f6b9 ('net/mlx5e: Support SRIOV TC encapsulation offloads for IPv6 tunnels')
Fixes: 3e621b19 ('net/mlx5e: Support TC encapsulation offloads with upper devices')
Signed-off-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c

@@ -15,6 +15,10 @@ static int get_route_and_out_devs(struct mlx5e_priv *priv,
 	struct net_device *uplink_dev, *uplink_upper;
 	bool dst_is_lag_dev;
 
+	/* we currently don't offload vlan on underlay */
+	if (is_vlan_dev(dev))
+		return -EOPNOTSUPP;
+
 	uplink_dev = mlx5_eswitch_uplink_get_proto_dev(esw, REP_ETH);
 	uplink_upper = netdev_master_upper_dev_get(uplink_dev);
 	dst_is_lag_dev = (uplink_upper &&
@@ -28,6 +32,8 @@ static int get_route_and_out_devs(struct mlx5e_priv *priv,
 	if (!switchdev_port_same_parent_id(priv->netdev, dev) ||
 	    dst_is_lag_dev)
 		*out_dev = uplink_dev;
+	else if (!mlx5e_eswitch_rep(dev))
+		return -EOPNOTSUPP;
 	else
 		*out_dev = dev;