[dpdk-dev] [PATCH] net/mlx5: example of modify field rte flow action

[Alexander Kozyrev <akozyrev@nvidia.com>]

This patch is a draft for upcoming full-fledged support
for newly added modify_field RTE Flow action.

The example shows how to use the modify_field API to set
a source or destination MAC address with an immediate
value specified by a user:

flow create 0 ingress group 0 pattern eth / end
    actions modify_field op set dst_type mac_dst
    src_type value src_value 12345678 width 32 / rss /end

Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
---
 drivers/net/mlx5/mlx5_flow.h    |   4 +-
 drivers/net/mlx5/mlx5_flow_dv.c | 120 ++++++++++++++++++++++++++++++++
 2 files changed, 123 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_flow.h b/drivers/net/mlx5/mlx5_flow.h
index eb9f97a278..27862edcd1 100644
--- a/drivers/net/mlx5/mlx5_flow.h
+++ b/drivers/net/mlx5/mlx5_flow.h
@@ -218,6 +218,7 @@ enum mlx5_feature_name {
 #define MLX5_FLOW_ACTION_SAMPLE (1ull << 36)
 #define MLX5_FLOW_ACTION_TUNNEL_SET (1ull << 37)
 #define MLX5_FLOW_ACTION_TUNNEL_MATCH (1ull << 38)
+#define MLX5_FLOW_ACTION_MODIFY_FIELD (1ull << 39)
 
 #define MLX5_FLOW_FATE_ACTIONS \
 	(MLX5_FLOW_ACTION_DROP | MLX5_FLOW_ACTION_QUEUE | \
@@ -248,7 +249,8 @@ enum mlx5_feature_name {
 				      MLX5_FLOW_ACTION_MARK_EXT | \
 				      MLX5_FLOW_ACTION_SET_META | \
 				      MLX5_FLOW_ACTION_SET_IPV4_DSCP | \
-				      MLX5_FLOW_ACTION_SET_IPV6_DSCP)
+				      MLX5_FLOW_ACTION_SET_IPV6_DSCP | \
+				      MLX5_FLOW_ACTION_MODIFY_FIELD)
 
 #define MLX5_FLOW_VLAN_ACTIONS (MLX5_FLOW_ACTION_OF_POP_VLAN | \
 				MLX5_FLOW_ACTION_OF_PUSH_VLAN)
diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 860ef9aa01..fc8e95132d 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -1320,6 +1320,52 @@ flow_dv_convert_action_modify_ipv6_dscp
 					     MLX5_MODIFICATION_TYPE_SET, error);
 }
 
+/**
+ * Convert modify_field action to DV specification.
+ *
+ * @param[in,out] resource
+ *   Pointer to the modify-header resource.
+ * @param[in] action
+ *   Pointer to action specification.
+ * @param[out] error
+ *   Pointer to the error structure.
+ *
+ * @return
+ *   0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+static int
+flow_dv_convert_action_modify_field
+			(struct mlx5_flow_dv_modify_hdr_resource *resource,
+			 const struct rte_flow_action *action,
+			 struct rte_flow_error *error)
+{
+	const struct rte_flow_action_modify_field *conf =
+		(const struct rte_flow_action_modify_field *)(action->conf);
+	struct rte_flow_item item = { .type = RTE_FLOW_ITEM_TYPE_ETH };
+	struct rte_flow_item_eth eth;
+	struct rte_flow_item_eth eth_mask;
+
+	memset(&eth, 0, sizeof(eth));
+	memset(&eth_mask, 0, sizeof(eth_mask));
+	if (conf->dst.field == RTE_FLOW_FIELD_MAC_SRC) {
+		memcpy(&eth.src.addr_bytes, &conf->src.value,
+		       sizeof(eth.src.addr_bytes));
+		memcpy(&eth_mask.src.addr_bytes,
+		       &rte_flow_item_eth_mask.src.addr_bytes,
+		       sizeof(eth_mask.src.addr_bytes));
+	} else {
+		memcpy(&eth.dst.addr_bytes, &conf->src.value,
+		       sizeof(eth.dst.addr_bytes));
+		memcpy(&eth_mask.dst.addr_bytes,
+		       &rte_flow_item_eth_mask.dst.addr_bytes,
+		       sizeof(eth_mask.dst.addr_bytes));
+	}
+	item.spec = &eth;
+	item.mask = &eth_mask;
+	return flow_dv_convert_modify_action(&item, modify_eth, NULL, resource,
+					     MLX5_MODIFICATION_TYPE_SET, error);
+}
+
 /**
  * Validate MARK item.
  *
@@ -3984,6 +4030,61 @@ flow_dv_validate_action_modify_ttl(const uint64_t action_flags,
 	return ret;
 }
 
+/**
+ * Validate the generic modify field actions.
+ *
+ * @param[in] action_flags
+ *   Holds the actions detected until now.
+ * @param[in] action
+ *   Pointer to the modify action.
+ * @param[in] item_flags
+ *   Holds the items detected.
+ * @param[out] error
+ *   Pointer to error structure.
+ *
+ * @return
+ *   0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+static int
+flow_dv_validate_action_modify_field(const uint64_t action_flags,
+				   const struct rte_flow_action *action,
+				   const uint64_t item_flags,
+				   struct rte_flow_error *error)
+{
+	int ret = 0;
+	const struct rte_flow_action_modify_field *action_modify_field =
+		action->conf;
+
+	ret = flow_dv_validate_action_modify_hdr(action_flags, action, error);
+	if (!ret) {
+		if (!(item_flags & MLX5_FLOW_LAYER_L2))
+			return rte_flow_error_set(error, EINVAL,
+						  RTE_FLOW_ERROR_TYPE_ACTION,
+						  NULL,
+						  "no L2 item in pattern");
+		if (action_modify_field->operation != RTE_FLOW_MODIFY_SET)
+			return rte_flow_error_set(error, EINVAL,
+						  RTE_FLOW_ERROR_TYPE_ACTION,
+						  NULL,
+						  "add and sub opearation are"
+						  " not supported");
+		if (action_modify_field->dst.field != RTE_FLOW_FIELD_MAC_DST &&
+		    action_modify_field->dst.field != RTE_FLOW_FIELD_MAC_SRC)
+			return rte_flow_error_set(error, EINVAL,
+						  RTE_FLOW_ERROR_TYPE_ACTION,
+						  NULL,
+						  "cannot modify requested"
+						  " header field");
+		if (action_modify_field->src.field != RTE_FLOW_FIELD_VALUE)
+			return rte_flow_error_set(error, EINVAL,
+						  RTE_FLOW_ERROR_TYPE_ACTION,
+						  NULL,
+						  "copy form another packet"
+						  " field is not suported");
+	}
+	return ret;
+}
+
 /**
  * Validate jump action.
  *
@@ -6120,6 +6221,19 @@ flow_dv_validate(struct rte_eth_dev *dev, const struct rte_flow_attr *attr,
 
 			action_flags |= MLX5_FLOW_ACTION_TUNNEL_SET;
 			break;
+		case RTE_FLOW_ACTION_TYPE_MODIFY_FIELD:
+			ret = flow_dv_validate_action_modify_field(action_flags,
+								 actions,
+								 item_flags,
+								 error);
+			if (ret < 0)
+				return ret;
+			/* Count all modify-header actions as one action. */
+			if (!(action_flags & MLX5_FLOW_ACTION_MODIFY_FIELD))
+				++actions_n;
+			action_flags |= MLX5_FLOW_ACTION_MODIFY_FIELD;
+			rw_act_num += MLX5_ACT_NUM_MDF_MAC;
+			break;
 		default:
 			return rte_flow_error_set(error, ENOTSUP,
 						  RTE_FLOW_ERROR_TYPE_ACTION,
@@ -10404,6 +10518,12 @@ flow_dv_translate(struct rte_eth_dev *dev,
 				sample_act->action_flags |=
 							MLX5_FLOW_ACTION_ENCAP;
 			break;
+		case RTE_FLOW_ACTION_TYPE_MODIFY_FIELD:
+			if (flow_dv_convert_action_modify_field
+					(mhdr_res, actions, error))
+				return -rte_errno;
+			action_flags |= MLX5_FLOW_ACTION_MODIFY_FIELD;
+			break;
 		case RTE_FLOW_ACTION_TYPE_END:
 			actions_end = true;
 			if (mhdr_res->actions_num) {
-- 
2.24.1