[dpdk-dev] [PATCH v2 1/2] ethdev: introduce generic copy rte flow action

[Alexander Kozyrev <akozyrev@nvidia.com>]

Implement a generic copy flow API to allow copying of an arbitrary
header field (as well as mark, metadata or tag) to another item.

This generic copy mechanism removes the necessity to implement a
separate RTE Flow action every time we need to modify a new packet
field in the future. A user-provided value can be used from a
specified tag/metadata or directly copied from other packet field.

The number of bits to copy as well as the offset to start from can
be specified to allow a partial copy or copy into an arbitrary
place in a packet for greater flexibility.

RFC: http://patches.dpdk.org/patch/85384/

Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
---
 doc/guides/prog_guide/rte_flow.rst | 35 ++++++++++++++++++
 lib/librte_ethdev/rte_flow.c       |  1 +
 lib/librte_ethdev/rte_flow.h       | 59 ++++++++++++++++++++++++++++++
 3 files changed, 95 insertions(+)

diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index 86b3444803..b737ff9dad 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -2766,6 +2766,41 @@ The behaviour of the shared action defined by ``action`` argument of type
    | no properties |
    +---------------+
 
+Action: ``COPY_ITEM``
+^^^^^^^^^^^^^^^^^^^^^
+
+Copy ``width`` bits from ``src`` item to ``dst`` item.
+
+An arbitrary header field (as well as mark, metadata or tag values)
+can be used as both source and destination items as set by ``item``.
+
+Inner packet header fields can be accessed using the ``index`` and
+it is possible to start the copy from the ``offset`` bits in an item.
+
+.. _table_rte_flow_action_copy_item:
+
+.. table:: COPY_ITEM
+
+   +-----------------------------------------+
+   | Field         | Value                   |
+   +===============+=========================+
+   | ``dst``       | destination item        |
+   | ``src``       | source item             |
+   | ``width``     | number of bits to copy  |
+   +---------------+-------------------------+
+
+.. _table_rte_flow_action_copy_data:
+
+.. table:: destination/source item definition
+
+   +----------------------------------------------------------+
+   | Field         | Value                                    |
+   +===============+==========================================+
+   | ``item``      | ID of a packet field/mark/metadata/tag   |
+   | ``index``     | index of outer/inner header or tag array |
+   | ``offset``    | number of bits to skip during the copy   |
+   +---------------+------------------------------------------+
+
 Negative types
 ~~~~~~~~~~~~~~
 
diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c
index a06f64c271..fdbabefc47 100644
--- a/lib/librte_ethdev/rte_flow.c
+++ b/lib/librte_ethdev/rte_flow.c
@@ -176,6 +176,7 @@ static const struct rte_flow_desc_data rte_flow_desc_action[] = {
 	MK_FLOW_ACTION(SET_IPV6_DSCP, sizeof(struct rte_flow_action_set_dscp)),
 	MK_FLOW_ACTION(AGE, sizeof(struct rte_flow_action_age)),
 	MK_FLOW_ACTION(SAMPLE, sizeof(struct rte_flow_action_sample)),
+	MK_FLOW_ACTION(COPY_ITEM, sizeof(struct rte_flow_action_copy_item)),
 	/**
 	 * Shared action represented as handle of type
 	 * (struct rte_flow_shared action *) stored in conf field (see
diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
index 0977a78270..5f10c38ffe 100644
--- a/lib/librte_ethdev/rte_flow.h
+++ b/lib/librte_ethdev/rte_flow.h
@@ -2198,6 +2198,16 @@ enum rte_flow_action_type {
 	 * struct rte_flow_shared_action).
 	 */
 	RTE_FLOW_ACTION_TYPE_SHARED,
+
+	/**
+	 * Copy a packet header field, tag, mark or metadata.
+	 *
+	 * Allow saving an arbitrary header field by copying its value
+	 * to a tag/mark/metadata or copy it into another header field.
+	 *
+	 * See struct rte_flow_action_copy_item.
+	 */
+	RTE_FLOW_ACTION_TYPE_COPY_ITEM,
 };
 
 /**
@@ -2791,6 +2801,55 @@ struct rte_flow_action_set_dscp {
  */
 struct rte_flow_shared_action;
 
+enum rte_flow_item_id {
+	RTE_FLOW_ITEM_NONE = 0,
+	RTE_FLOW_ITEM_MAC_DST,
+	RTE_FLOW_ITEM_MAC_SRC,
+	RTE_FLOW_ITEM_VLAN_TYPE,
+	RTE_FLOW_ITEM_VLAN_ID,
+	RTE_FLOW_ITEM_MAC_TYPE,
+	RTE_FLOW_ITEM_IPV4_DSCP,
+	RTE_FLOW_ITEM_IPV4_TTL,
+	RTE_FLOW_ITEM_IPV4_SRC,
+	RTE_FLOW_ITEM_IPV4_DST,
+	RTE_FLOW_ITEM_IPV6_HOPLIMIT,
+	RTE_FLOW_ITEM_IPV6_SRC,
+	RTE_FLOW_ITEM_IPV6_DST,
+	RTE_FLOW_ITEM_TCP_PORT_SRC,
+	RTE_FLOW_ITEM_TCP_PORT_DST,
+	RTE_FLOW_ITEM_TCP_SEQ_NUM,
+	RTE_FLOW_ITEM_TCP_ACK_NUM,
+	RTE_FLOW_ITEM_TCP_FLAGS,
+	RTE_FLOW_ITEM_UDP_PORT_SRC,
+	RTE_FLOW_ITEM_UDP_PORT_DST,
+	RTE_FLOW_ITEM_VXLAN_VNI,
+	RTE_FLOW_ITEM_GENEVE_VNI,
+	RTE_FLOW_ITEM_GTP_TEID,
+	RTE_FLOW_ITEM_TAG,
+	RTE_FLOW_ITEM_MARK,
+	RTE_FLOW_ITEM_META,
+};
+
+struct rte_flow_action_copy_data {
+	enum rte_flow_item_id item;
+	uint32_t index;
+	uint32_t offset;
+};
+
+/**
+ * RTE_FLOW_ACTION_TYPE_COPY_ITEM
+ *
+ * Copies a specified number of bits from a source header field
+ * to a destination header field. Tag, mark or metadata can also
+ * be used as a source/destination to allow saving/overwriting
+ * an arbitrary header field with a user-specified value.
+ */
+struct rte_flow_action_copy_item {
+	struct rte_flow_action_copy_data dst;
+	struct rte_flow_action_copy_data src;
+	uint32_t width;
+};
+
 /* Mbuf dynamic field offset for metadata. */
 extern int32_t rte_flow_dynf_metadata_offs;
 
-- 
2.24.1