[PATCH v4 1/2] ethdev: add random item support

[Michael Baum <michaelba@nvidia.com>]

Add support for a new item type "RTE_FLOW_ITEM_TYPE_RANDOM".
This item enables to match on some random value as a part of flow rule.

Signed-off-by: Michael Baum <michaelba@nvidia.com>
---
 doc/guides/nics/features/default.ini   |  1 +
 doc/guides/prog_guide/rte_flow.rst     | 14 +++++++++++
 doc/guides/rel_notes/release_24_03.rst |  5 ++++
 lib/ethdev/rte_flow.c                  |  1 +
 lib/ethdev/rte_flow.h                  | 35 +++++++++++++++++++++++++-
 5 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/doc/guides/nics/features/default.ini b/doc/guides/nics/features/default.ini
index 806cb033ff..6d50236292 100644
--- a/doc/guides/nics/features/default.ini
+++ b/doc/guides/nics/features/default.ini
@@ -140,6 +140,7 @@ pppoe_proto_id       =
 ptype                =
 quota                =
 raw                  =
+random               =
 represented_port     =
 sctp                 =
 tag                  =
diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index 627b845bfb..900fdaefb6 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -1573,6 +1573,20 @@ Matches the packet type as defined in rte_mbuf_ptype.
 
 - ``packet_type``: L2/L3/L4 and tunnel information.
 
+Item: ``RANDOM``
+^^^^^^^^^^^^^^^^
+
+Matches a random value.
+
+A random unsigned integer (at most 32-bit) is generated for each packet during
+flow rule processing, by either HW, SW or some external source.
+Application can match on either exact value or range of values.
+This value is not based on the packet data/headers.
+Application shouldn't assume that this value is kept during the lifetime of
+the packet.
+
+- ``value``: Specific value to match.
+
 Actions
 ~~~~~~~
 
diff --git a/doc/guides/rel_notes/release_24_03.rst b/doc/guides/rel_notes/release_24_03.rst
index 6f8ad27808..819cef7f20 100644
--- a/doc/guides/rel_notes/release_24_03.rst
+++ b/doc/guides/rel_notes/release_24_03.rst
@@ -55,6 +55,11 @@ New Features
      Also, make sure to start the actual text at the margin.
      =======================================================
 
+* **Added flow matching of random value.**
+
+  * Added ``RTE_FLOW_ITEM_TYPE_RANDOM`` to match random value.
+  * Added ``RTE_FLOW_FIELD_RANDOM`` to represent it in field API.
+
 
 Removed Items
 -------------
diff --git a/lib/ethdev/rte_flow.c b/lib/ethdev/rte_flow.c
index 549e329558..090b936ca9 100644
--- a/lib/ethdev/rte_flow.c
+++ b/lib/ethdev/rte_flow.c
@@ -136,6 +136,7 @@ static const struct rte_flow_desc_data rte_flow_desc_item[] = {
 		     sizeof(struct rte_flow_item_icmp6_nd_opt_tla_eth)),
 	MK_FLOW_ITEM(MARK, sizeof(struct rte_flow_item_mark)),
 	MK_FLOW_ITEM(META, sizeof(struct rte_flow_item_meta)),
+	MK_FLOW_ITEM(RANDOM, sizeof(struct rte_flow_item_random)),
 	MK_FLOW_ITEM(TAG, sizeof(struct rte_flow_item_tag)),
 	MK_FLOW_ITEM(GRE_KEY, sizeof(rte_be32_t)),
 	MK_FLOW_ITEM(GRE_OPTION, sizeof(struct rte_flow_item_gre_opt)),
diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
index affdc8121b..860b100e45 100644
--- a/lib/ethdev/rte_flow.h
+++ b/lib/ethdev/rte_flow.h
@@ -704,6 +704,19 @@ enum rte_flow_item_type {
 	 *
 	 */
 	RTE_FLOW_ITEM_TYPE_PTYPE,
+
+	/**
+	 * [META]
+	 *
+	 * Matches a random value.
+	 *
+	 * This value is not based on the packet data/headers.
+	 * Application shouldn't assume that this value is kept during the
+	 * lifetime of the packet.
+	 *
+	 * @see struct rte_flow_item_random.
+	 */
+	RTE_FLOW_ITEM_TYPE_RANDOM,
 };
 
 /**
@@ -2047,6 +2060,25 @@ static const struct rte_flow_item_ib_bth rte_flow_item_ib_bth_mask = {
 };
 #endif
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this structure may change without prior notice
+ *
+ * RTE_FLOW_ITEM_TYPE_RANDOM
+ *
+ * Matches a random value.
+ */
+struct rte_flow_item_random {
+	uint32_t value;
+};
+
+/** Default mask for RTE_FLOW_ITEM_TYPE_RANDOM. */
+#ifndef __cplusplus
+static const struct rte_flow_item_random rte_flow_item_random_mask = {
+	.value = UINT32_MAX,
+};
+#endif
+
 /**
  * Matching pattern item definition.
  *
@@ -3903,7 +3935,8 @@ enum rte_flow_field_id {
 	RTE_FLOW_FIELD_TCP_DATA_OFFSET,	/**< TCP data offset. */
 	RTE_FLOW_FIELD_IPV4_IHL,	/**< IPv4 IHL. */
 	RTE_FLOW_FIELD_IPV4_TOTAL_LEN,	/**< IPv4 total length. */
-	RTE_FLOW_FIELD_IPV6_PAYLOAD_LEN	/**< IPv6 payload length. */
+	RTE_FLOW_FIELD_IPV6_PAYLOAD_LEN,/**< IPv6 payload length. */
+	RTE_FLOW_FIELD_RANDOM		/**< Random value. */
 };
 
 /**
-- 
2.25.1