[dpdk-dev] [PATCH v1 3/7] ethdev: add flow API item/action name conversion

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

This provides a means for applications to retrieve the name of flow pattern
items and actions.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
---
 doc/guides/prog_guide/rte_flow.rst |  1 +
 lib/librte_ether/rte_flow.c        | 62 +++++++++++++++++++++++++++++++++
 lib/librte_ether/rte_flow.h        | 52 +++++++++++++++++++++++++++
 3 files changed, 115 insertions(+)

diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index 5026730..a346ba5 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -1715,6 +1715,7 @@ operations include:
 - Attributes, pattern item or action duplication.
 - Duplication of an entire pattern or list of actions.
 - Duplication of a complete flow rule description.
+- Pattern item or action name retrieval.
 
 Caveats
 -------
diff --git a/lib/librte_ether/rte_flow.c b/lib/librte_ether/rte_flow.c
index 03a4d35..f4fb607 100644
--- a/lib/librte_ether/rte_flow.c
+++ b/lib/librte_ether/rte_flow.c
@@ -465,6 +465,60 @@ rte_flow_conv_rule(struct rte_flow_conv_rule *dst,
 		 "not enough room for alignment padding");
 }
 
+/** Internal helper to convert an object type to a string. */
+static int
+rte_flow_conv_name(int is_action,
+		   char *dst,
+		   size_t size,
+		   const void *src,
+		   struct rte_flow_error *error)
+{
+	const struct {
+		const struct rte_flow_desc_data *data;
+		size_t num;
+	} res_data[2] = {
+		{ rte_flow_desc_item, RTE_DIM(rte_flow_desc_item), },
+		{ rte_flow_desc_action, RTE_DIM(rte_flow_desc_action), },
+	}, *const res = &res_data[!!is_action];
+	unsigned int obj_type = (uintptr_t)src;
+
+	if (obj_type >= res->num)
+		return rte_flow_error_set
+			(error, EINVAL, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
+			 "unknown object type to retrieve name for");
+	return snprintf(dst, size, "%s", res->data[obj_type].name);
+}
+
+/** Internal helper to convert an object type to a pointer to its name. */
+static int
+rte_flow_conv_name_ptr(int is_action,
+		       const char **dst,
+		       size_t size,
+		       const void *src,
+		       struct rte_flow_error *error)
+{
+	const struct {
+		const struct rte_flow_desc_data *data;
+		size_t num;
+	} res_data[2] = {
+		{ rte_flow_desc_item, RTE_DIM(rte_flow_desc_item), },
+		{ rte_flow_desc_action, RTE_DIM(rte_flow_desc_action), },
+	}, *const res = &res_data[!!is_action];
+	unsigned int obj_type = (uintptr_t)src;
+
+	if (obj_type >= res->num)
+		return rte_flow_error_set
+			(error, EINVAL, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
+			 "unknown object type to retrieve name for");
+	if (size && size < sizeof(const char **))
+		return rte_flow_error_set
+			(error, ENOMEM, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
+			 "not enough room for object name pointer");
+	if (size)
+		*((const char **)dst) = res->data[obj_type].name;
+	return sizeof(const char **);
+}
+
 /** Helper function to convert flow API objects. */
 int
 rte_flow_conv(enum rte_flow_conv_op op,
@@ -497,6 +551,14 @@ rte_flow_conv(enum rte_flow_conv_op op,
 		return rte_flow_conv_actions(dst, size, src, 0, error);
 	case RTE_FLOW_CONV_OP_RULE:
 		return rte_flow_conv_rule(dst, size, src, error);
+	case RTE_FLOW_CONV_OP_ITEM_NAME:
+		return rte_flow_conv_name(0, dst, size, src, error);
+	case RTE_FLOW_CONV_OP_ACTION_NAME:
+		return rte_flow_conv_name(1, dst, size, src, error);
+	case RTE_FLOW_CONV_OP_ITEM_NAME_PTR:
+		return rte_flow_conv_name_ptr(0, dst, size, src, error);
+	case RTE_FLOW_CONV_OP_ACTION_NAME_PTR:
+		return rte_flow_conv_name_ptr(1, dst, size, src, error);
 	}
 	return rte_flow_error_set
 		(error, EINVAL, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
diff --git a/lib/librte_ether/rte_flow.h b/lib/librte_ether/rte_flow.h
index 3d06bdc..01c711e 100644
--- a/lib/librte_ether/rte_flow.h
+++ b/lib/librte_ether/rte_flow.h
@@ -1180,6 +1180,58 @@ enum rte_flow_conv_op {
 	 *   @code struct rte_flow_conv_rule * @endcode
 	 */
 	RTE_FLOW_CONV_OP_RULE,
+
+	/**
+	 * Convert item type to its name string.
+	 *
+	 * Writes a NUL-terminated string to @p dst (like snprintf()).
+	 *
+	 * - @p src type:
+	 *   @code (const void *)enum rte_flow_item_type @endcode
+	 * - @p dst type:
+	 *   @code char * @endcode
+	 **/
+	RTE_FLOW_CONV_OP_ITEM_NAME,
+
+	/**
+	 * Convert action type to its name string.
+	 *
+	 * Writes a NUL-terminated string to @p dst (like snprintf()).
+	 *
+	 * - @p src type:
+	 *   @code (const void *)enum rte_flow_action_type @endcode
+	 * - @p dst type:
+	 *   @code char * @endcode
+	 **/
+	RTE_FLOW_CONV_OP_ACTION_NAME,
+
+	/**
+	 * Convert item type to pointer to item name.
+	 *
+	 * Retrieves item name pointer from its type. The string itself is
+	 * not copied; instead, a unique pointer to an internal static
+	 * constant storage is written to @p dst.
+	 *
+	 * - @p src type:
+	 *   @code (const void *)enum rte_flow_item_type @endcode
+	 * - @p dst type:
+	 *   @code const char ** @endcode
+	 */
+	RTE_FLOW_CONV_OP_ITEM_NAME_PTR,
+
+	/**
+	 * Convert action type to pointer to action name.
+	 *
+	 * Retrieves action name pointer from its type. The string itself is
+	 * not copied; instead, a unique pointer to an internal static
+	 * constant storage is written to @p dst.
+	 *
+	 * - @p src type:
+	 *   @code (const void *)enum rte_flow_action_type @endcode
+	 * - @p dst type:
+	 *   @code const char ** @endcode
+	 */
+	RTE_FLOW_CONV_OP_ACTION_NAME_PTR,
 };
 
 /**
-- 
2.1.4