net/mlx5e: Deny VLAN rewrite if there is no VLAN header match

Rewrite of the packet in the VLAN offset may corrupt the packet if it's
not VLAN tagged. Deny the rewrite in this case.

Fixes: 37410902874c ("net/mlx5e: Support VLAN modify action")
Signed-off-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 81f8ac569a0e1550bed6f6687abd2facfd2d950c..3a0854fbcfd4351f44b5acf6a25ee36be7a54537 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2292,8 +2292,19 @@ static int add_vlan_rewrite_action(struct mlx5e_priv *priv, int namespace,
                .mangle.mask = ~(u32)be16_to_cpu(*(__be16 *)&mask16),
                .mangle.val = (u32)be16_to_cpu(*(__be16 *)&val16),
        };
+       void *headers_c, *headers_v;
        int err;
 
+       headers_c = get_match_headers_criteria(*action, &parse_attr->spec);
+       headers_v = get_match_headers_value(*action, &parse_attr->spec);
+
+       if (!(MLX5_GET(fte_match_set_lyr_2_4, headers_c, cvlan_tag) &&
+             MLX5_GET(fte_match_set_lyr_2_4, headers_v, cvlan_tag))) {
+               NL_SET_ERR_MSG_MOD(extack,
+                                  "VLAN rewrite action must have VLAN protocol match");
+               return -EOPNOTSUPP;
+       }
+
        if (act->vlan.prio) {
                NL_SET_ERR_MSG_MOD(extack, "Setting VLAN prio is not supported");
                return -EOPNOTSUPP;