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Diffstat (limited to 'Documentation/userspace-api/netlink/genetlink-legacy.rst')
| -rw-r--r-- | Documentation/userspace-api/netlink/genetlink-legacy.rst | 38 |
1 files changed, 31 insertions, 7 deletions
diff --git a/Documentation/userspace-api/netlink/genetlink-legacy.rst b/Documentation/userspace-api/netlink/genetlink-legacy.rst index 40b82ad5d54a..fa005989193a 100644 --- a/Documentation/userspace-api/netlink/genetlink-legacy.rst +++ b/Documentation/userspace-api/netlink/genetlink-legacy.rst @@ -11,6 +11,20 @@ the ``genetlink-legacy`` protocol level. Specification ============= +Globals +------- + +Attributes listed directly at the root level of the spec file. + +version +~~~~~~~ + +Generic Netlink family version, default is 1. + +``version`` has historically been used to introduce family changes +which may break backwards compatibility. Since compatibility breaking changes +are generally not allowed ``version`` is very rarely used. + Attribute type nests -------------------- @@ -32,10 +46,16 @@ For reference the ``multi-attr`` array may look like this:: where ``ARRAY-ATTR`` is the array entry type. -array-nest -~~~~~~~~~~ +indexed-array +~~~~~~~~~~~~~ + +``indexed-array`` wraps the entire array in an extra attribute (hence +limiting its size to 64kB). The ``ENTRY`` nests are special and have the +index of the entry as their type instead of normal attribute type. -``array-nest`` creates the following structure:: +A ``sub-type`` is needed to describe what type in the ``ENTRY``. A ``nest`` +``sub-type`` means there are nest arrays in the ``ENTRY``, with the structure +looks like:: [SOME-OTHER-ATTR] [ARRAY-ATTR] @@ -46,9 +66,13 @@ array-nest [MEMBER1] [MEMBER2] -It wraps the entire array in an extra attribute (hence limiting its size -to 64kB). The ``ENTRY`` nests are special and have the index of the entry -as their type instead of normal attribute type. +Other ``sub-type`` like ``u32`` means there is only one member as described +in ``sub-type`` in the ``ENTRY``. The structure looks like:: + + [SOME-OTHER-ATTR] + [ARRAY-ATTR] + [ENTRY u32] + [ENTRY u32] type-value ~~~~~~~~~~ @@ -168,7 +192,7 @@ members - ``name`` - The attribute name of the struct member - ``type`` - One of the scalar types ``u8``, ``u16``, ``u32``, ``u64``, ``s8``, - ``s16``, ``s32``, ``s64``, ``string`` or ``binary``. + ``s16``, ``s32``, ``s64``, ``string``, ``binary`` or ``bitfield32``. - ``byte-order`` - ``big-endian`` or ``little-endian`` - ``doc``, ``enum``, ``enum-as-flags``, ``display-hint`` - Same as for :ref:`attribute definitions <attribute_properties>` |