Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-01-07 13:53:24 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

doc/netlink: Add sub-message support to netlink-raw

Browse Source 
Add a 'sub-message' attribute type with a selector that supports
polymorphic attribute formats for raw netlink families like tc.

A sub-message attribute uses the value of another attribute as a
selector key to choose the right sub-message format. For example if the
following attribute has already been decoded:

  { "kind": "gre" }

and we encounter the following attribute spec:

  -
    name: data
    type: sub-message
    sub-message: linkinfo-data-msg
    selector: kind

Then we look for a sub-message definition called 'linkinfo-data-msg' and
use the value of the 'kind' attribute i.e. 'gre' as the key to choose
the correct format for the sub-message:

  sub-messages:
    name: linkinfo-data-msg
    formats:
      -
        value: bridge
        attribute-set: linkinfo-bridge-attrs
      -
        value: gre
        attribute-set: linkinfo-gre-attrs
      -
        value: geneve
        attribute-set: linkinfo-geneve-attrs

This would decode the attribute value as a sub-message with the
attribute-set called 'linkinfo-gre-attrs' as the attribute space.

A sub-message can have an optional 'fixed-header' followed by zero or
more attributes from an attribute-set. For example the following
'tc-options-msg' sub-message defines message formats that use a mixture
of fixed-header, attribute-set or both together:

  sub-messages:
    -
      name: tc-options-msg
      formats:
        -
          value: bfifo
          fixed-header: tc-fifo-qopt
        -
          value: cake
          attribute-set: tc-cake-attrs
        -
          value: netem
          fixed-header: tc-netem-qopt
          attribute-set: tc-netem-attrs

Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20231215093720.18774-3-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Donald Hunter 2023-12-15 09:37:09 +00:00 committed by Jakub Kicinski
parent 62691b801d
commit de2d98743b
1 changed files with 62 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

65
Documentation/netlink/netlink-raw.yaml
View File

@ -126,8 +126,10 @@ properties:
name:
type: string
type:
description: The netlink attribute type
enum: [ u8, u16, u32, u64, s8, s16, s32, s64, string, binary ]
description: |
The netlink attribute type. Members of type 'binary' or 'pad'
must also have the 'len' property set.
enum: [ u8, u16, u32, u64, s8, s16, s32, s64, string, binary, pad ]
len:
$ref: '#/$defs/len-or-define'
byte-order:
@ -150,6 +152,14 @@ properties:
the right formatting mechanism when displaying values of this
type.
enum: [ hex, mac, fddi, ipv4, ipv6, uuid ]
if:
properties:
type:
oneOf:
- const: binary
- const: pad
then:
required: [ len ]
# End genetlink-legacy
attribute-sets:
@ -202,7 +212,8 @@ properties:
description: The netlink attribute type
enum: [ unused, pad, flag, binary, bitfield32,
u8, u16, u32, u64, s8, s16, s32, s64,
string, nest, array-nest, nest-type-value ]
string, nest, array-nest, nest-type-value,
sub-message ]
doc:
description: Documentation of the attribute.
type: string
@ -261,6 +272,17 @@ properties:
description: Name of the struct type used for the attribute.
type: string
# End genetlink-legacy
# Start netlink-raw
sub-message:
description: |
Name of the sub-message definition to use for the attribute.
type: string
selector:
description: |
Name of the attribute to use for dynamic selection of sub-message
format specifier.
type: string
# End netlink-raw
# Make sure name-prefix does not appear in subsets (subsets inherit naming)
dependencies:
@ -283,6 +305,43 @@ properties:
items:
required: [ type ]
# Start netlink-raw
sub-messages:
description: Definition of sub message attributes
type: array
items:
type: object
additionalProperties: False
required: [ name, formats ]
properties:
name:
description: Name of the sub-message definition
type: string
formats:
description: Dynamically selected format specifiers
type: array
items:
type: object
additionalProperties: False
required: [ value ]
properties:
value:
description: |
Value to match for dynamic selection of sub-message format
specifier.
type: string
fixed-header:
description: |
Name of the struct definition to use as the fixed header
for the sub message.
type: string
attribute-set:
description: |
Name of the attribute space from which to resolve attributes
in the sub message.
type: string
# End netlink-raw
operations:
description: Operations supported by the protocol.
type: object