[SRU][Bionic][PATCH 5/5] net/mlx5e: Don't match on vlan non-existence if ethertype is wildcarded

[Juerg Haefliger]

From: Or Gerlitz <ogerlitz at mellanox.com>

BugLink: https://bugs.launchpad.net/bugs/1842502

For the "all" ethertype we should not care whether the packet has
vlans. Besides being wrong, the way we did it caused FW error
for rules such as:

tc filter add dev eth0 protocol all parent ffff: \
	prio 1 flower skip_sw action drop

b/c the matching meta-data (outer headers bit in struct mlx5_flow_spec)
wasn't set. Fix that by matching on vlan non-existence only if we were
also told to match on the ethertype.

Fixes: cee26487620b ('net/mlx5e: Set vlan masks for all offloaded TC rules')
Signed-off-by: Or Gerlitz <ogerlitz at mellanox.com>
Reported-by: Slava Ovsiienko <viacheslavo at mellanox.com>
Reviewed-by: Jianbo Liu <jianbol at mellanox.com>
Reviewed-by: Roi Dayan <roid at mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm at mellanox.com>
(backported from commit d3a80bb5a3eac311ddf28387402593977574460d)
[juergh: Adjusted for missing commit 699e96ddf47f ("net/mlx5e: Support
 offloading tc double vlan headers match").]
Signed-off-by: Juerg Haefliger <juergh at canonical.com>
---
 .../net/ethernet/mellanox/mlx5/core/en_tc.c   | 63 ++++++++++---------
 1 file changed, 32 insertions(+), 31 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index cb17eb25f696..3c21b347895f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -780,31 +780,21 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
 					 inner_headers);
 	}
 
-	if (dissector_uses_key(f->dissector, FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
-		struct flow_dissector_key_eth_addrs *key =
+	if (dissector_uses_key(f->dissector, FLOW_DISSECTOR_KEY_BASIC)) {
+		struct flow_dissector_key_basic *key =
 			skb_flow_dissector_target(f->dissector,
-						  FLOW_DISSECTOR_KEY_ETH_ADDRS,
+						  FLOW_DISSECTOR_KEY_BASIC,
 						  f->key);
-		struct flow_dissector_key_eth_addrs *mask =
+		struct flow_dissector_key_basic *mask =
 			skb_flow_dissector_target(f->dissector,
-						  FLOW_DISSECTOR_KEY_ETH_ADDRS,
+						  FLOW_DISSECTOR_KEY_BASIC,
 						  f->mask);
+		MLX5_SET(fte_match_set_lyr_2_4, headers_c, ethertype,
+			 ntohs(mask->n_proto));
+		MLX5_SET(fte_match_set_lyr_2_4, headers_v, ethertype,
+			 ntohs(key->n_proto));
 
-		ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_c,
-					     dmac_47_16),
-				mask->dst);
-		ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_v,
-					     dmac_47_16),
-				key->dst);
-
-		ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_c,
-					     smac_47_16),
-				mask->src);
-		ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_v,
-					     smac_47_16),
-				key->src);
-
-		if (!is_zero_ether_addr(mask->src) || !is_zero_ether_addr(mask->dst))
+		if (mask->n_proto)
 			*match_level = MLX5_MATCH_L2;
 	}
 
@@ -829,26 +819,37 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
 
 			*match_level = MLX5_MATCH_L2;
 		}
-	} else {
+	} else if (*match_level != MLX5_MATCH_NONE) {
 		MLX5_SET(fte_match_set_lyr_2_4, headers_c, svlan_tag, 1);
 		MLX5_SET(fte_match_set_lyr_2_4, headers_c, cvlan_tag, 1);
+		*match_level = MLX5_MATCH_L2;
 	}
 
-	if (dissector_uses_key(f->dissector, FLOW_DISSECTOR_KEY_BASIC)) {
-		struct flow_dissector_key_basic *key =
+	if (dissector_uses_key(f->dissector, FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
+		struct flow_dissector_key_eth_addrs *key =
 			skb_flow_dissector_target(f->dissector,
-						  FLOW_DISSECTOR_KEY_BASIC,
+						  FLOW_DISSECTOR_KEY_ETH_ADDRS,
 						  f->key);
-		struct flow_dissector_key_basic *mask =
+		struct flow_dissector_key_eth_addrs *mask =
 			skb_flow_dissector_target(f->dissector,
-						  FLOW_DISSECTOR_KEY_BASIC,
+						  FLOW_DISSECTOR_KEY_ETH_ADDRS,
 						  f->mask);
-		MLX5_SET(fte_match_set_lyr_2_4, headers_c, ethertype,
-			 ntohs(mask->n_proto));
-		MLX5_SET(fte_match_set_lyr_2_4, headers_v, ethertype,
-			 ntohs(key->n_proto));
 
-		if (mask->n_proto)
+		ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_c,
+					     dmac_47_16),
+				mask->dst);
+		ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_v,
+					     dmac_47_16),
+				key->dst);
+
+		ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_c,
+					     smac_47_16),
+				mask->src);
+		ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_v,
+					     smac_47_16),
+				key->src);
+
+		if (!is_zero_ether_addr(mask->src) || !is_zero_ether_addr(mask->dst))
 			*match_level = MLX5_MATCH_L2;
 	}
 
-- 
2.20.1