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Diffstat (limited to 'Documentation/userspace-api/netlink/netlink-raw.rst')
| -rw-r--r-- | Documentation/userspace-api/netlink/netlink-raw.rst | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/userspace-api/netlink/netlink-raw.rst b/Documentation/userspace-api/netlink/netlink-raw.rst index 1e14f5f22b8e..1990eea772d0 100644 --- a/Documentation/userspace-api/netlink/netlink-raw.rst +++ b/Documentation/userspace-api/netlink/netlink-raw.rst @@ -150,3 +150,45 @@ attributes from an ``attribute-set``. For example the following Note that a selector attribute must appear in a netlink message before any sub-message attributes that depend on it. + +If an attribute such as ``kind`` is defined at more than one nest level, then a +sub-message selector will be resolved using the value 'closest' to the selector. +For example, if the same attribute name is defined in a nested ``attribute-set`` +alongside a sub-message selector and also in a top level ``attribute-set``, then +the selector will be resolved using the value 'closest' to the selector. If the +value is not present in the message at the same level as defined in the spec +then this is an error. + +Nested struct definitions +------------------------- + +Many raw netlink families such as :doc:`tc<../../networking/netlink_spec/tc>` +make use of nested struct definitions. The ``netlink-raw`` schema makes it +possible to embed a struct within a struct definition using the ``struct`` +property. For example, the following struct definition embeds the +``tc-ratespec`` struct definition for both the ``rate`` and the ``peakrate`` +members of ``struct tc-tbf-qopt``. + +.. code-block:: yaml + + - + name: tc-tbf-qopt + type: struct + members: + - + name: rate + type: binary + struct: tc-ratespec + - + name: peakrate + type: binary + struct: tc-ratespec + - + name: limit + type: u32 + - + name: buffer + type: u32 + - + name: mtu + type: u32 |