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Diffstat (limited to 'Documentation/userspace-api')
| -rw-r--r-- | Documentation/userspace-api/netlink/specs.rst | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/Documentation/userspace-api/netlink/specs.rst b/Documentation/userspace-api/netlink/specs.rst index 6ffe8137cd90..a22442ba1d30 100644 --- a/Documentation/userspace-api/netlink/specs.rst +++ b/Documentation/userspace-api/netlink/specs.rst @@ -24,6 +24,10 @@ YAML specifications can be found under ``Documentation/netlink/specs/`` This document describes details of the schema. See :doc:`intro-specs` for a practical starting guide. +All specs must be licensed under +``((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)`` +to allow for easy adoption in user space code. + Compatibility levels ==================== @@ -197,9 +201,15 @@ value Numerical attribute ID, used in serialized Netlink messages. The ``value`` property can be skipped, in which case the attribute ID will be the value of the previous attribute plus one (recursively) -and ``0`` for the first attribute in the attribute set. +and ``1`` for the first attribute in the attribute set. + +Attributes (and operations) use ``1`` as the default value for the first +entry (unlike enums in definitions which start from ``0``) because +entry ``0`` is almost always reserved as undefined. Spec can explicitly +set value to ``0`` if needed. -Note that the ``value`` of an attribute is defined only in its main set. +Note that the ``value`` of an attribute is defined only in its main set +(not in subsets). enum ~~~~ |