[dpdk-dev] [PATCH v7 1/5] ethdev: add extensions attributes to IPv6 item

[Dekel Peled <dekelp@nvidia.com>]

Using the current implementation of DPDK, an application cannot match on
IPv6 packets, based on the existing extension headers, in a simple way.

Field 'Next Header' in IPv6 header indicates type of the first extension
header only. Following extension headers can't be identified by
inspecting the IPv6 header.
As a result, the existence or absence of specific extension headers
can't be used for packet matching.

For example, fragmented IPv6 packets contain a dedicated extension header
(which is implemented in a later patch of this series).
Non-fragmented packets don't contain the fragment extension header.
For an application to match on non-fragmented IPv6 packets, the current
implementation doesn't provide a suitable solution.
Matching on the Next Header field is not sufficient, since additional
extension headers might be present in the same packet.
To match on fragmented IPv6 packets, the same difficulty exists.

This patch implements the update as detailed in RFC [1].
A set of additional values will be added to IPv6 header struct.
These values will indicate the existence of every defined extension
header type, providing simple means for identification of existing
extensions in the packet header.
Continuing the above example, fragmented packets can be identified using
the specific value indicating existence of fragment extension header.
To match on non-fragmented IPv6 packets, need to use has_frag_ext 0.
To match on fragmented IPv6 packets, need to use has_frag_ext 1.
To match on any IPv6 packets, the has_frag_ext field should
not be specified for match.

[1] https://mails.dpdk.org/archives/dev/2020-August/177257.html

Signed-off-by: Dekel Peled <dekelp@nvidia.com>
Acked-by: Ori Kam <orika@nvidia.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
---
 doc/guides/prog_guide/rte_flow.rst     | 20 +++++++++++++++++---
 doc/guides/rel_notes/deprecation.rst   |  5 -----
 doc/guides/rel_notes/release_20_11.rst |  5 +++++
 lib/librte_ethdev/rte_flow.h           | 23 +++++++++++++++++++++--
 4 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index f26a6c2..97fdf2a 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -946,11 +946,25 @@ Item: ``IPV6``
 
 Matches an IPv6 header.
 
-Note: IPv6 options are handled by dedicated pattern items, see `Item:
-IPV6_EXT`_.
+Dedicated flags indicate if header contains specific extension headers.
+To match on packets containing a specific extension header, an application
+should match on the dedicated flag set to 1.
+To match on packets not containing a specific extension header, an application
+should match on the dedicated flag clear to 0.
+In case application doesn't care about the existence of a specific extension
+header, it should not specify the dedicated flag for matching.
 
 - ``hdr``: IPv6 header definition (``rte_ip.h``).
-- Default ``mask`` matches source and destination addresses only.
+- ``has_hop_ext``: header contains Hop-by-Hop Options extension header.
+- ``has_route_ext``: header contains Routing extension header.
+- ``has_frag_ext``: header contains Fragment extension header.
+- ``has_auth_ext``: header contains Authentication extension header.
+- ``has_esp_ext``: header contains Encapsulation Security Payload extension header.
+- ``has_dest_ext``: header contains Destination Options extension header.
+- ``has_mobil_ext``: header contains Mobility extension header.
+- ``has_hip_ext``: header contains Host Identity Protocol extension header.
+- ``has_shim6_ext``: header contains Shim6 Protocol extension header.
+- Default ``mask`` matches ``hdr`` source and destination addresses only.
 
 Item: ``ICMP``
 ^^^^^^^^^^^^^^
diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 584e720..87a7c44 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -159,11 +159,6 @@ Deprecation Notices
   or absence of a VLAN header following the current header, as proposed in RFC
   https://mails.dpdk.org/archives/dev/2020-August/177536.html.
 
-* ethdev: The ``struct rte_flow_item_ipv6`` struct will be modified to include
-  additional values, indicating existence or absence of IPv6 extension headers
-  following the IPv6 header, as proposed in RFC
-  https://mails.dpdk.org/archives/dev/2020-August/177257.html.
-
 * security: The API ``rte_security_session_create`` takes only single mempool
   for session and session private data. So the application need to create
   mempool for twice the number of sessions needed and will also lead to
diff --git a/doc/guides/rel_notes/release_20_11.rst b/doc/guides/rel_notes/release_20_11.rst
index 30db8f2..730e9df 100644
--- a/doc/guides/rel_notes/release_20_11.rst
+++ b/doc/guides/rel_notes/release_20_11.rst
@@ -351,6 +351,11 @@ ABI Changes
 
   * ``ethdev`` internal functions are marked with ``__rte_internal`` tag.
 
+  * Added extensions' attributes to struct ``rte_flow_item_ipv6``.
+    A set of additional values added to struct, indicating the existence of
+    every defined extension header type.
+    Applications should use the new values for identification of existing
+    extensions in the packet header.
 
 Known Issues
 ------------
diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
index 3d5fb09..aa18925 100644
--- a/lib/librte_ethdev/rte_flow.h
+++ b/lib/librte_ethdev/rte_flow.h
@@ -792,11 +792,30 @@ struct rte_flow_item_ipv4 {
  *
  * Matches an IPv6 header.
  *
- * Note: IPv6 options are handled by dedicated pattern items, see
- * RTE_FLOW_ITEM_TYPE_IPV6_EXT.
+ * Dedicated flags indicate if header contains specific extension headers.
  */
 struct rte_flow_item_ipv6 {
 	struct rte_ipv6_hdr hdr; /**< IPv6 header definition. */
+	uint32_t has_hop_ext:1;
+	/**< Header contains Hop-by-Hop Options extension header. */
+	uint32_t has_route_ext:1;
+	/**< Header contains Routing extension header. */
+	uint32_t has_frag_ext:1;
+	/**< Header contains Fragment extension header. */
+	uint32_t has_auth_ext:1;
+	/**< Header contains Authentication extension header. */
+	uint32_t has_esp_ext:1;
+	/**< Header contains Encapsulation Security Payload extension header. */
+	uint32_t has_dest_ext:1;
+	/**< Header contains Destination Options extension header. */
+	uint32_t has_mobil_ext:1;
+	/**< Header contains Mobility extension header. */
+	uint32_t has_hip_ext:1;
+	/**< Header contains Host Identity Protocol extension header. */
+	uint32_t has_shim6_ext:1;
+	/**< Header contains Shim6 Protocol extension header. */
+	uint32_t reserved:23;
+	/**< Reserved for future extension headers, must be zero. */
 };
 
 /** Default mask for RTE_FLOW_ITEM_TYPE_IPV6. */
-- 
1.8.3.1