netdev - [PATCH net-next v3 7/7] docs: netlink: document the sub-type attribute property

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20230324113734.1473-8-donald.hunter@gmail.com>
Date:   Fri, 24 Mar 2023 11:37:34 +0000
From:   Donald Hunter <donald.hunter@...il.com>
To:     netdev@...r.kernel.org, Jakub Kicinski <kuba@...nel.org>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Paolo Abeni <pabeni@...hat.com>,
        Jonathan Corbet <corbet@....net>, linux-doc@...r.kernel.org
Cc:     donald.hunter@...hat.com, Donald Hunter <donald.hunter@...il.com>
Subject: [PATCH net-next v3 7/7] docs: netlink: document the sub-type attribute property

Add a definition for sub-type to the protocol spec doc and a description of
its usage for C arrays in genetlink-legacy.

Signed-off-by: Donald Hunter <donald.hunter@...il.com>
---
 .../userspace-api/netlink/genetlink-legacy.rst     | 14 ++++++++++++++
 Documentation/userspace-api/netlink/specs.rst      |  9 +++++++++
 2 files changed, 23 insertions(+)

diff --git a/Documentation/userspace-api/netlink/genetlink-legacy.rst b/Documentation/userspace-api/netlink/genetlink-legacy.rst
index 6b385a9e6d0b..afd9c4947a1c 100644
--- a/Documentation/userspace-api/netlink/genetlink-legacy.rst
+++ b/Documentation/userspace-api/netlink/genetlink-legacy.rst
@@ -216,6 +216,20 @@ specify a sub-type.
           type: binary
           struct: vport-stats
 
+C Arrays
+--------
+
+Legacy families also use ``binary`` attributes to encapsulate C arrays. The
+``sub-type`` is used to identify the type of scalar to extract.
+
+.. code-block:: yaml
+
+  attributes:
+    -
+      name: ports
+      type: binary
+      sub-type: u32
+
 Multi-message DO
 ----------------
 
diff --git a/Documentation/userspace-api/netlink/specs.rst b/Documentation/userspace-api/netlink/specs.rst
index a22442ba1d30..7931322d3238 100644
--- a/Documentation/userspace-api/netlink/specs.rst
+++ b/Documentation/userspace-api/netlink/specs.rst
@@ -254,6 +254,15 @@ rather than depend on what is specified in the spec file.
 The validation policy in the kernel is formed by combining the type
 definition (``type`` and ``nested-attributes``) and the ``checks``.
 
+sub-type
+~~~~~~~~
+
+Attributes can have a ``sub-type`` that is interpreted in a ``type``
+specific way. For example, an attribute with ``type: binary`` can have
+``sub-type: u32`` which says to interpret the binary blob as an array of
+``u32``. Binary types are described in more detail in
+:doc:`genetlink-legacy`.
+
 operations
 ----------
 
-- 
2.39.0