xref: /linux/Documentation/netlink/genetlink-c.yaml (revision 375c4d1583948cf2439833e4a85d5a0aee853895)
1# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
2%YAML 1.2
3---
4$id: http://kernel.org/schemas/netlink/genetlink-c.yaml#
5$schema: https://json-schema.org/draft-07/schema
6
7# Common defines
8$defs:
9  uint:
10    type: integer
11    minimum: 0
12  len-or-define:
13    type: [ string, integer ]
14    pattern: ^[0-9A-Za-z_-]+( - 1)?$
15    minimum: 0
16  len-or-limit:
17    # literal int or limit based on fixed-width type e.g. u8-min, u16-max, etc.
18    type: [ string, integer ]
19    pattern: ^[su](8|16|32|64)-(min|max)$
20    minimum: 0
21
22# Schema for specs
23title: Protocol
24description: Specification of a genetlink protocol
25type: object
26required: [ name, doc, attribute-sets, operations ]
27additionalProperties: False
28properties:
29  name:
30    description: Name of the genetlink family.
31    type: string
32  doc:
33    type: string
34  protocol:
35    description: Schema compatibility level. Default is "genetlink".
36    enum: [ genetlink, genetlink-c ]
37  uapi-header:
38    description: Path to the uAPI header, default is linux/${family-name}.h
39    type: string
40  # Start genetlink-c
41  c-family-name:
42    description: Name of the define for the family name.
43    type: string
44  c-version-name:
45    description: Name of the define for the version of the family.
46    type: string
47  max-by-define:
48    description: Makes the number of attributes and commands be specified by a define, not an enum value.
49    type: boolean
50  cmd-max-name:
51    description: Name of the define for the last operation in the list.
52    type: string
53  cmd-cnt-name:
54    description: The explicit name for constant holding the count of operations (last operation + 1).
55    type: string
56  # End genetlink-c
57
58  definitions:
59    description: List of type and constant definitions (enums, flags, defines).
60    type: array
61    items:
62      type: object
63      required: [ type, name ]
64      additionalProperties: False
65      properties:
66        name:
67          type: string
68        header:
69          description: For C-compatible languages, header which already defines this value.
70          type: string
71        type:
72          enum: [ const, enum, flags ]
73        doc:
74          type: string
75        # For const
76        value:
77          description: For const - the value.
78          type: [ string, integer ]
79        # For enum and flags
80        value-start:
81          description: For enum or flags the literal initializer for the first value.
82          type: [ string, integer ]
83        entries:
84          description: For enum or flags array of values.
85          type: array
86          items:
87            oneOf:
88              - type: string
89              - type: object
90                required: [ name ]
91                additionalProperties: False
92                properties:
93                  name:
94                    type: string
95                  value:
96                    type: integer
97                  doc:
98                    type: string
99        render-max:
100          description: Render the max members for this enum.
101          type: boolean
102        # Start genetlink-c
103        enum-name:
104          description: Name for enum, if empty no name will be used.
105          type: [ string, "null" ]
106        name-prefix:
107          description: For enum the prefix of the values, optional.
108          type: string
109        # End genetlink-c
110
111  attribute-sets:
112    description: Definition of attribute spaces for this family.
113    type: array
114    items:
115      description: Definition of a single attribute space.
116      type: object
117      required: [ name, attributes ]
118      additionalProperties: False
119      properties:
120        name:
121          description: |
122            Name used when referring to this space in other definitions, not used outside of the spec.
123          type: string
124        name-prefix:
125          description: |
126            Prefix for the C enum name of the attributes. Default family[name]-set[name]-a-
127          type: string
128        enum-name:
129          description: |
130            Name for the enum type of the attribute, if empty no name will be used.
131          type: [ string, "null" ]
132        doc:
133          description: Documentation of the space.
134          type: string
135        subset-of:
136          description: |
137            Name of another space which this is a logical part of. Sub-spaces can be used to define
138            a limited group of attributes which are used in a nest.
139          type: string
140        # Start genetlink-c
141        attr-cnt-name:
142          description: The explicit name for constant holding the count of attributes (last attr + 1).
143          type: string
144        attr-max-name:
145          description: The explicit name for last member of attribute enum.
146          type: string
147        # End genetlink-c
148        attributes:
149          description: List of attributes in the space.
150          type: array
151          items:
152            type: object
153            required: [ name ]
154            additionalProperties: False
155            properties:
156              name:
157                type: string
158              type: &attr-type
159                enum: [ unused, pad, flag, binary,
160                        uint, sint, u8, u16, u32, u64, s32, s64,
161                        string, nest, indexed-array, nest-type-value ]
162              doc:
163                description: Documentation of the attribute.
164                type: string
165              value:
166                description: Value for the enum item representing this attribute in the uAPI.
167                $ref: '#/$defs/uint'
168              type-value:
169                description: Name of the value extracted from the type of a nest-type-value attribute.
170                type: array
171                items:
172                  type: string
173              byte-order:
174                enum: [ little-endian, big-endian ]
175              multi-attr:
176                type: boolean
177              nested-attributes:
178                description: Name of the space (sub-space) used inside the attribute.
179                type: string
180              enum:
181                description: Name of the enum type used for the attribute.
182                type: string
183              enum-as-flags:
184                description: |
185                  Treat the enum as flags. In most cases enum is either used as flags or as values.
186                  Sometimes, however, both forms are necessary, in which case header contains the enum
187                  form while specific attributes may request to convert the values into a bitfield.
188                type: boolean
189              checks:
190                description: Kernel input validation.
191                type: object
192                additionalProperties: False
193                properties:
194                  flags-mask:
195                    description: Name of the flags constant on which to base mask (unsigned scalar types only).
196                    type: string
197                  min:
198                    description: Min value for an integer attribute.
199                    $ref: '#/$defs/len-or-limit'
200                  max:
201                    description: Max value for an integer attribute.
202                    $ref: '#/$defs/len-or-limit'
203                  min-len:
204                    description: Min length for a binary attribute.
205                    $ref: '#/$defs/len-or-define'
206                  max-len:
207                    description: Max length for a string or a binary attribute.
208                    $ref: '#/$defs/len-or-define'
209                  exact-len:
210                    description: Exact length for a string or a binary attribute.
211                    $ref: '#/$defs/len-or-define'
212                  unterminated-ok:
213                    description: |
214                      For string attributes, do not check whether attribute
215                      contains the terminating null character.
216                    type: boolean
217              sub-type: *attr-type
218              display-hint: &display-hint
219                description: |
220                  Optional format indicator that is intended only for choosing
221                  the right formatting mechanism when displaying values of this
222                  type.
223                enum: [ hex, mac, fddi, ipv4, ipv6, uuid ]
224              # Start genetlink-c
225              name-prefix:
226                type: string
227              # End genetlink-c
228
229      # Make sure name-prefix does not appear in subsets (subsets inherit naming)
230      dependencies:
231        name-prefix:
232          not:
233            required: [ subset-of ]
234        subset-of:
235          not:
236            required: [ name-prefix ]
237
238      # type property is only required if not in subset definition
239      if:
240        properties:
241          subset-of:
242            not:
243              type: string
244      then:
245        properties:
246          attributes:
247            items:
248              required: [ type ]
249
250  operations:
251    description: Operations supported by the protocol.
252    type: object
253    required: [ list ]
254    additionalProperties: False
255    properties:
256      enum-model:
257        description: |
258          The model of assigning values to the operations.
259          "unified" is the recommended model where all message types belong
260          to a single enum.
261          "directional" has the messages sent to the kernel and from the kernel
262          enumerated separately.
263        enum: [ unified ]
264      name-prefix:
265        description: |
266          Prefix for the C enum name of the command. The name is formed by concatenating
267          the prefix with the upper case name of the command, with dashes replaced by underscores.
268        type: string
269      enum-name:
270        description: |
271          Name for the enum type with commands, if empty no name will be used.
272        type: [ string, "null" ]
273      async-prefix:
274        description: Same as name-prefix but used to render notifications and events to separate enum.
275        type: string
276      async-enum:
277        description: |
278          Name for the enum type with commands, if empty no name will be used.
279        type: [ string, "null" ]
280      list:
281        description: List of commands
282        type: array
283        items:
284          type: object
285          additionalProperties: False
286          required: [ name, doc ]
287          properties:
288            name:
289              description: Name of the operation, also defining its C enum value in uAPI.
290              type: string
291            doc:
292              description: Documentation for the command.
293              type: string
294            value:
295              description: Value for the enum in the uAPI.
296              $ref: '#/$defs/uint'
297            attribute-set:
298              description: |
299                Attribute space from which attributes directly in the requests and replies
300                to this command are defined.
301              type: string
302            flags: &cmd_flags
303              description: Command flags.
304              type: array
305              items:
306                enum: [ admin-perm ]
307            dont-validate:
308              description: Kernel attribute validation flags.
309              type: array
310              items:
311                enum: [ strict, dump, dump-strict ]
312            config-cond:
313              description: |
314                Name of the kernel config option gating the presence of
315                the operation, without the 'CONFIG_' prefix.
316              type: string
317            do: &subop-type
318              description: Main command handler.
319              type: object
320              additionalProperties: False
321              properties:
322                request: &subop-attr-list
323                  description: Definition of the request message for a given command.
324                  type: object
325                  additionalProperties: False
326                  properties:
327                    attributes:
328                      description: |
329                        Names of attributes from the attribute-set (not full attribute
330                        definitions, just names).
331                      type: array
332                      items:
333                        type: string
334                reply: *subop-attr-list
335                pre:
336                  description: Hook for a function to run before the main callback (pre_doit or start).
337                  type: string
338                post:
339                  description: Hook for a function to run after the main callback (post_doit or done).
340                  type: string
341            dump: *subop-type
342            notify:
343              description: Name of the command sharing the reply type with this notification.
344              type: string
345            event:
346              type: object
347              additionalProperties: False
348              properties:
349                attributes:
350                  description: Explicit list of the attributes for the notification.
351                  type: array
352                  items:
353                    type: string
354            mcgrp:
355              description: Name of the multicast group generating given notification.
356              type: string
357  mcast-groups:
358    description: List of multicast groups.
359    type: object
360    required: [ list ]
361    additionalProperties: False
362    properties:
363      list:
364        description: List of groups.
365        type: array
366        items:
367          type: object
368          required: [ name ]
369          additionalProperties: False
370          properties:
371            name:
372              description: |
373                The name for the group, used to form the define and the value of the define.
374              type: string
375            # Start genetlink-c
376            c-define-name:
377              description: Override for the name of the define in C uAPI.
378              type: string
379            # End genetlink-c
380            flags: *cmd_flags
381
382  kernel-family:
383    description: Additional global attributes used for kernel C code generation.
384    type: object
385    additionalProperties: False
386    properties:
387      headers:
388        description: |
389          List of extra headers which should be included in the source
390          of the generated code.
391        type: array
392        items:
393          type: string
394      sock-priv:
395        description: |
396          Literal name of the type which is used within the kernel
397          to store the socket state. The type / structure is internal
398          to the kernel, and is not defined in the spec.
399        type: string
400