[dpdk-dev] [PATCH v2] ethdev: add fuzzy match pattern

[Qi Zhang]

Add new meta pattern item RTE_FLOW_TYPE_ITEM_FUZZY.

This is for device that support fuzzy  match option.
Usually a fuzzy match is fast but the cost is accuracy.
i.e. Signature Match only match pattern's hash value, but it is
possible two different patterns have the same hash value.

Matching accuracy level can be configure by subfield threshold.
Driver can divide the range of threshold and map to different
accuracy levels that device support.

Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
---

v2:
- replace "Roughly" with "Fuzzy"

 app/test-pmd/cmdline_flow.c                 | 24 ++++++++++++++
 app/test-pmd/config.c                       |  1 +
 doc/guides/prog_guide/rte_flow.rst          | 50 +++++++++++++++++++++++++++++
 doc/guides/testpmd_app_ug/testpmd_funcs.rst |  2 ++
 lib/librte_ether/rte_flow.h                 | 30 +++++++++++++++++
 5 files changed, 107 insertions(+)

diff --git a/app/test-pmd/cmdline_flow.c b/app/test-pmd/cmdline_flow.c
index 0fd69f9..048d455 100644
--- a/app/test-pmd/cmdline_flow.c
+++ b/app/test-pmd/cmdline_flow.c
@@ -107,6 +107,8 @@ enum index {
 	ITEM_END,
 	ITEM_VOID,
 	ITEM_INVERT,
+	ITEM_FUZZY,
+	ITEM_FUZZY_THRESHOLD,
 	ITEM_ANY,
 	ITEM_ANY_NUM,
 	ITEM_PF,
@@ -426,6 +428,7 @@ static const enum index next_item[] = {
 	ITEM_END,
 	ITEM_VOID,
 	ITEM_INVERT,
+	ITEM_FUZZY,
 	ITEM_ANY,
 	ITEM_PF,
 	ITEM_VF,
@@ -447,6 +450,12 @@ static const enum index next_item[] = {
 	ZERO,
 };
 
+static const enum index item_fuzzy[] = {
+	ITEM_FUZZY_THRESHOLD,
+	ITEM_NEXT,
+	ZERO,
+};
+
 static const enum index item_any[] = {
 	ITEM_ANY_NUM,
 	ITEM_NEXT,
@@ -954,6 +963,21 @@ static const struct token token_list[] = {
 		.next = NEXT(NEXT_ENTRY(ITEM_NEXT)),
 		.call = parse_vc,
 	},
+	[ITEM_FUZZY] = {
+		.name = "fuzzy",
+		.help = "match the pattern fuzzy",
+		.priv = PRIV_ITEM(FUZZY,
+				sizeof(struct rte_flow_item_fuzzy)),
+		.next = NEXT(item_fuzzy),
+		.call = parse_vc,
+	},
+	[ITEM_FUZZY_THRESHOLD] = {
+		.name = "threshold",
+		.help = "match accuracy threshold",
+		.next = NEXT(item_fuzzy, NEXT_ENTRY(UNSIGNED), item_param),
+		.args = ARGS(ARGS_ENTRY(struct rte_flow_item_fuzzy,
+					threshold)),
+	},
 	[ITEM_ANY] = {
 		.name = "any",
 		.help = "match any protocol for the current layer",
diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 4d873cd..db7b740 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -954,6 +954,7 @@ static const struct {
 	MK_FLOW_ITEM(END, 0),
 	MK_FLOW_ITEM(VOID, 0),
 	MK_FLOW_ITEM(INVERT, 0),
+	MK_FLOW_ITEM(FUZZY, sizeof(struct rte_flow_item_fuzzy)),
 	MK_FLOW_ITEM(ANY, sizeof(struct rte_flow_item_any)),
 	MK_FLOW_ITEM(PF, 0),
 	MK_FLOW_ITEM(VF, sizeof(struct rte_flow_item_vf)),
diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index b587ba9..516a0ac 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -491,6 +491,7 @@ Usage example, matching non-TCPv4 packets only:
 
    +-------+----------+
    | Index | Item     |
+
    +=======+==========+
    | 0     | INVERT   |
    +-------+----------+
@@ -503,6 +504,55 @@ Usage example, matching non-TCPv4 packets only:
    | 4     | END      |
    +-------+----------+
 
+Item: ``FUZZY``
+^^^^^^^^^^^^^^^^^
+
+Fuzzy matching, not perfect match.
+
+This is for device that support fuzzy match option.
+Usually a fuzzy  match is fast but the cost is accuracy.
+i.e. Signature Match only match pattern's hash value, but it is
+possible two different patterns have the same hash value.
+
+Matching accuracy level can be configure by threshold.
+Driver can divide the range of threshold and map to different
+accuracy levels that device support.
+
+.. _table_rte_flow_item_fuzzy:
+
+.. table:: FUZZY
+
+   +----------+---------------+--------------------------------------------------+
+   | Field    |   Subfield    | Value                                            |
+   +==========+===========+======================================================+
+   | ``spec`` | ``threshold`` | 0 as perfect match, 0xffffffff as fuzzies match |
+   +----------+---------------+--------------------------------------------------+
+   | ``last`` | ``threshold`` | ignored                                          |
+   +----------+-----------+------------------------------------------------------+
+   | ``mask`` | ``threshold`` | ignored                                          |
+   +----------+-----------+------------------------------------------------------+
+
+
+Usage example, fuzzy match a TCPv4 packets:
+
+.. _table_rte_flow_item_fuzzy_example:
+
+.. table:: Fuzzy matching
+
+   +-------+----------+
+   | Index | Item     |
+   +=======+==========+
+   | 0     | FUZZY    |
+   +-------+----------+
+   | 1     | Ethernet |
+   +-------+----------+
+   | 2     | IPv4     |
+   +-------+----------+
+   | 3     | TCP      |
+   +-------+----------+
+   | 4     | END      |
+   +-------+----------+
+
 Item: ``PF``
 ^^^^^^^^^^^^
 
diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
index 0e50c10..0b1d927 100644
--- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
+++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
@@ -2513,6 +2513,8 @@ This section lists supported pattern items and their attributes, if any.
 
 - ``invert``: perform actions when pattern does not match.
 
+- ``fuzzy``: this is a fuzzy match..
+
 - ``any``: match any protocol for the current layer.
 
   - ``num {unsigned}``: number of layers covered.
diff --git a/lib/librte_ether/rte_flow.h b/lib/librte_ether/rte_flow.h
index c47edbc..b27e858 100644
--- a/lib/librte_ether/rte_flow.h
+++ b/lib/librte_ether/rte_flow.h
@@ -148,6 +148,18 @@ enum rte_flow_item_type {
 	RTE_FLOW_ITEM_TYPE_INVERT,
 
 	/**
+	 * [META]
+	 *
+	 * Fuzzy matching, not perfect matching
+	 *
+	 * This is for device that support fuzzy matching option.
+	 * Usually a fuzzy matching is fast but the cost is accuracy.
+	 *
+	 * See struct rte_flow_item_fuzzy
+	 */
+	RTE_FLOW_ITEM_TYPE_FUZZY,
+
+	/**
 	 * Matches any protocol in place of the current layer, a single ANY
 	 * may also stand for several protocol layers.
 	 *
@@ -300,6 +312,24 @@ enum rte_flow_item_type {
 };
 
 /**
+ * RTE_FLOW_ITEM_TYPE_FUZZY
+ *
+ * Fuzzy matching, not perfect match.
+ *
+ * This is for device that support fuzzy match option.
+ * Usually a fuzzy match is fast but the cost is accuracy.
+ * i.e. Signature Match only match pattern's hash value, but it is
+ * possible two different patterns have the same hash value.
+ *
+ * Matching accuracy level can be configure by threshold.
+ * Driver can divide the range of threshold and map to different
+ * accuracy levels that device support.
+ */
+struct rte_flow_item_fuzzy {
+	uint32_t threshold; /**< accuracy threshold*/
+};
+
+/**
  * RTE_FLOW_ITEM_TYPE_ANY
  *
  * Matches any protocol in place of the current layer, a single ANY may also
-- 
2.7.4