[PATCH net-next] net/mlx5e: Add FLOW_DISSECTOR_KEY_META parse support

[PATCH net-next] net/mlx5e: Add FLOW_DISSECTOR_KEY_META parse support

[wenxu]

From: wenxu <wenxu@ucloud.cn>

In the FT_OFFLOAD all the forward devices share the same block.
If there are more than two devices the wrong flows will be
installed on the devices.

For three devices: A, B, C
The flow received from A forward to B will install on device A
forward to B. And install on C forward to B. (The flow install on B
forward to B will be failed). It should be avoid this case through
FLOW_DISSECTOR_KEY_META.

Signed-off-by: wenxu <wenxu@ucloud.cn>
---
The flowtable offload will support this as following patch. 
http://patchwork.ozlabs.org/patch/1218109/

 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 39 +++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 0d5d84b..eadc608 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -1802,6 +1802,40 @@ static void *get_match_headers_value(u32 flags,
 			     outer_headers);
 }
 
+static int mlx5e_flower_parse_meta(struct net_device *filter_dev,
+				   struct flow_cls_offload *f)
+{
+	struct flow_rule *rule = flow_cls_offload_flow_rule(f);
+	struct netlink_ext_ack *extack = f->common.extack;
+	struct net_device *ingress_dev;
+	struct flow_match_meta match;
+
+	if (!flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_META))
+		return 0;
+
+	flow_rule_match_meta(rule, &match);
+	if (match.mask->ingress_ifindex != 0xFFFFFFFF) {
+		NL_SET_ERR_MSG_MOD(extack, "Unsupported ingress ifindex mask");
+		return -EINVAL;
+	}
+
+	ingress_dev = __dev_get_by_index(dev_net(filter_dev),
+					 match.key->ingress_ifindex);
+	if (!ingress_dev) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Can't find the ingress port to match on");
+		return -EINVAL;
+	}
+
+	if (ingress_dev != filter_dev) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Can't match on the ingress filter port");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int __parse_cls_flower(struct mlx5e_priv *priv,
 			      struct mlx5_flow_spec *spec,
 			      struct flow_cls_offload *f,
@@ -1822,6 +1856,7 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
 	u16 addr_type = 0;
 	u8 ip_proto = 0;
 	u8 *match_level;
+	int err;
 
 	match_level = outer_match_level;
 
@@ -1865,6 +1900,10 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
 						    spec);
 	}
 
+	err = mlx5e_flower_parse_meta(filter_dev, f);
+	if (err)
+		return err;
+
 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_BASIC)) {
 		struct flow_match_basic match;
 
-- 
1.8.3.1