[dpdk-dev] [PATCH 2/3] ethdev: support flow elements with variable length

[Viacheslav Ovsiienko <viacheslavo@nvidia.com>]

From: Gregory Etelson <getelson@nvidia.com>

RTE flow API provides RAW item type for packet patterns of variable
length. The RAW item structure has fixed size members that describe the
variable pattern length and methods to process it.

A new RTE flow item type with variable length pattern that does not
fit the RAW item meta description could not use the RAW item.
For example, the new flow item that references 64 bits PMD handler
cannot be described by the RAW item.

The patch allows RTE conv helper functions to process custom flow
items with variable length pattern.

Signed-off-by: Gregory Etelson <getelson@nvidia.com>
---
 lib/ethdev/rte_flow.c | 68 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 55 insertions(+), 13 deletions(-)

diff --git a/lib/ethdev/rte_flow.c b/lib/ethdev/rte_flow.c
index 8cb7a069c8..fe199eaeb3 100644
--- a/lib/ethdev/rte_flow.c
+++ b/lib/ethdev/rte_flow.c
@@ -30,13 +30,54 @@ uint64_t rte_flow_dynf_metadata_mask;
 struct rte_flow_desc_data {
 	const char *name;
 	size_t size;
+	size_t (*desc_fn)(void *dst, const void *src);
 };
 
+/**
+ *
+ * @param buf
+ * Destination memory.
+ * @param data
+ * Source memory
+ * @param size
+ * Requested copy size
+ * @param desc
+ * rte_flow_desc_item - for flow item conversion.
+ * rte_flow_desc_action - for flow action conversion.
+ * @param type
+ * Offset into the desc param or negative value for private flow elements.
+ */
+static inline size_t
+rte_flow_conv_copy(void *buf, const void *data, const size_t size,
+		   const struct rte_flow_desc_data *desc, int type)
+{
+	/**
+	 * allow PMD private flow item
+	 * see 5d1bff8fe2
+	 * "ethdev: allow negative values in flow rule types"
+	 */
+	size_t sz = type >= 0 ? desc[type].size : sizeof(void *);
+	if (buf == NULL || data == NULL)
+		return 0;
+	rte_memcpy(buf, data, (size > sz ? sz : size));
+	if (desc[type].desc_fn)
+		sz += desc[type].desc_fn(size > 0 ? buf : NULL, data);
+	return sz;
+}
+
 /** Generate flow_item[] entry. */
 #define MK_FLOW_ITEM(t, s) \
 	[RTE_FLOW_ITEM_TYPE_ ## t] = { \
 		.name = # t, \
-		.size = s, \
+		.size = s,               \
+		.desc_fn = NULL,\
+	}
+
+#define MK_FLOW_ITEM_FN(t, s, fn) \
+	[RTE_FLOW_ITEM_TYPE_ ## t] = {\
+		.name = # t,                 \
+		.size = s,                   \
+		.desc_fn = fn,               \
 	}
 
 /** Information about known flow pattern items. */
@@ -107,8 +148,17 @@ static const struct rte_flow_desc_data rte_flow_desc_item[] = {
 	[RTE_FLOW_ACTION_TYPE_ ## t] = { \
 		.name = # t, \
 		.size = s, \
+		.desc_fn = NULL,\
+	}
+
+#define MK_FLOW_ACTION_FN(t, fn) \
+	[RTE_FLOW_ACTION_TYPE_ ## t] = { \
+		.name = # t, \
+		.size = 0, \
+		.desc_fn = fn,\
 	}
 
+
 /** Information about known flow actions. */
 static const struct rte_flow_desc_data rte_flow_desc_action[] = {
 	MK_FLOW_ACTION(END, 0),
@@ -527,12 +577,8 @@ rte_flow_conv_item_spec(void *buf, const size_t size,
 		}
 		break;
 	default:
-		/**
-		 * allow PMD private flow item
-		 */
-		off = (int)item->type >= 0 ?
-		      rte_flow_desc_item[item->type].size : sizeof(void *);
-		rte_memcpy(buf, data, (size > off ? off : size));
+		off = rte_flow_conv_copy(buf, data, size,
+					 rte_flow_desc_item, item->type);
 		break;
 	}
 	return off;
@@ -634,12 +680,8 @@ rte_flow_conv_action_conf(void *buf, const size_t size,
 		}
 		break;
 	default:
-		/**
-		 * allow PMD private flow action
-		 */
-		off = (int)action->type >= 0 ?
-		      rte_flow_desc_action[action->type].size : sizeof(void *);
-		rte_memcpy(buf, action->conf, (size > off ? off : size));
+		off = rte_flow_conv_copy(buf, action->conf, size,
+					 rte_flow_desc_action, action->type);
 		break;
 	}
 	return off;
-- 
2.18.1