[net 03/15] net/mlx5e: Don't match double-vlan packets if cvlan is not set

[Saeed Mahameed <saeedm@nvidia.com>]

From: Vlad Buslov <vladbu@nvidia.com>

Currently, match VLAN rule also matches packets that have multiple VLAN
headers. This behavior is similar to buggy flower classifier behavior that
has recently been fixed. Fix the issue by matching on
outer_second_cvlan_tag with value 0 which will cause the HW to verify the
packet doesn't contain second vlan header.

Fixes: 699e96ddf47f ("net/mlx5e: Support offloading tc double vlan headers match")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index e3fc15ae7bb1..ac0f73074f7a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2459,6 +2459,17 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
 				 match.key->vlan_priority);
 
 			*match_level = MLX5_MATCH_L2;
+
+			if (!flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_CVLAN) &&
+			    match.mask->vlan_eth_type &&
+			    MLX5_CAP_FLOWTABLE_TYPE(priv->mdev,
+						    ft_field_support.outer_second_vid,
+						    fs_type)) {
+				MLX5_SET(fte_match_set_misc, misc_c,
+					 outer_second_cvlan_tag, 1);
+				spec->match_criteria_enable |=
+					MLX5_MATCH_MISC_PARAMETERS;
+			}
 		}
 	} else if (*match_level != MLX5_MATCH_NONE) {
 		/* cvlan_tag enabled in match criteria and
-- 
2.35.1