netdev - RE: [PATCH net-next v3 2/2] tools: ynl-gen: fix parse multi-attr enum attribute

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Date: Wed, 19 Jul 2023 21:08:52 +0000
From: "Kubalewski, Arkadiusz" <arkadiusz.kubalewski@...el.com>
To: Donald Hunter <donald.hunter@...il.com>
CC: "kuba@...nel.org" <kuba@...nel.org>, "netdev@...r.kernel.org"
	<netdev@...r.kernel.org>, "davem@...emloft.net" <davem@...emloft.net>,
	"pabeni@...hat.com" <pabeni@...hat.com>, "edumazet@...gle.com"
	<edumazet@...gle.com>
Subject: RE: [PATCH net-next v3 2/2] tools: ynl-gen: fix parse multi-attr enum
 attribute

>From: Donald Hunter <donald.hunter@...il.com>
>Sent: Wednesday, July 19, 2023 1:18 PM
>
>On Tue, 18 Jul 2023 at 17:24, Arkadiusz Kubalewski
><arkadiusz.kubalewski@...el.com> wrote:
>>
>>  tools/net/ynl/lib/ynl.py | 20 ++++++++++----------
>>  1 file changed, 10 insertions(+), 10 deletions(-)
>>
>> diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
>> index 5db7d47067f9..671ef4b5eaa6 100644
>> --- a/tools/net/ynl/lib/ynl.py
>> +++ b/tools/net/ynl/lib/ynl.py
>> @@ -135,7 +135,7 @@ class NlAttr:
>>          format = self.get_format(type)
>>          return [ x[0] for x in format.iter_unpack(self.raw) ]
>>
>> -    def as_struct(self, members):
>> +    def as_struct(self, members, attr_spec):
>
>No need to pass attr_spec - it's the spec for the struct, not for the
>members.

Yep, that what I was thinking in previous version thread.

>
>>          value = dict()
>>          offset = 0
>>          for m in members:
>> @@ -147,6 +147,9 @@ class NlAttr:
>>                  format = self.get_format(m.type, m.byte_order)
>>                  [ decoded ] = format.unpack_from(self.raw, offset)
>>                  offset += format.size
>> +
>> +            if m.enum:
>> +                decoded = self._decode_enum(decoded, attr_spec)
>
>_decode_enum is not a method on NlAttr so I'm pretty sure this will
>fail. Looks like we need to move _decode_enum() into NlAttr?
>

Are you sure about moving it? it seems all the decode function are members of
YnlFamily.

>The second param to _decode_enum should be 'm' which is the attr spec
>for the member.

Ok, will do. Altough I think of moving back _decode_enum() to the
_decode_binary(), where it was initially, but with proper usage like:
  for m in members:
    if m.enum:
      decoded[m.name] = self._decode_enum(decoded[m.name], m)

This way all the decode function would be kept in YnlFamily.
Does it make sense?

>
>>              if m.display_hint:
>>                  decoded = self.formatted_string(decoded, m.display_hint)
>>              value[m.name] = decoded
>> @@ -417,8 +420,7 @@ class YnlFamily(SpecFamily):
>>          pad = b'\x00' * ((4 - len(attr_payload) % 4) % 4)
>>          return struct.pack('HH', len(attr_payload) + 4, nl_type) +
>>attr_payload + pad
>>
>> -    def _decode_enum(self, rsp, attr_spec):
>> -        raw = rsp[attr_spec['name']]
>> +    def _decode_enum(self, raw, attr_spec):
>>          enum = self.consts[attr_spec['enum']]
>>          if 'enum-as-flags' in attr_spec and attr_spec['enum-as-flags']:
>>              i = attr_spec.get('value-start', 0)
>> @@ -430,15 +432,12 @@ class YnlFamily(SpecFamily):
>>                  i += 1
>>          else:
>>              value = enum.entries_by_val[raw].name
>> -        rsp[attr_spec['name']] = value
>> +        return value
>>
>>      def _decode_binary(self, attr, attr_spec):
>>          if attr_spec.struct_name:
>>              members = self.consts[attr_spec.struct_name]
>> -            decoded = attr.as_struct(members)
>> -            for m in members:
>> -                if m.enum:
>> -                    self._decode_enum(decoded, m)
>> +            decoded = attr.as_struct(members, attr_spec)
>>          elif attr_spec.sub_type:
>>              decoded = attr.as_c_array(attr_spec.sub_type)
>>          else:
>> @@ -466,6 +465,9 @@ class YnlFamily(SpecFamily):
>>              else:
>>                  raise Exception(f'Unknown {attr_spec["type"]} with name
>>{attr_spec["name"]}')
>>
>> +            if 'enum' in attr_spec:
>> +                decoded = self._decode_enum(int.from_bytes(attr.raw,
>>"big"), attr_spec)
>
>As Jakub said, this should just be self._decode_enum(decoded, attr_spec)
>

Yes, will fix.

Thank you!
Arkadiusz

>> +
>>              if not attr_spec.is_multi:
>>                  rsp[attr_spec['name']] = decoded
>>              elif attr_spec.name in rsp:
>> @@ -473,8 +475,6 @@ class YnlFamily(SpecFamily):
>>              else:
>>                  rsp[attr_spec.name] = [decoded]
>>
>> -            if 'enum' in attr_spec:
>> -                self._decode_enum(rsp, attr_spec)
>>          return rsp
>>
>>      def _decode_extack_path(self, attrs, attr_set, offset, target):
>> --
>> 2.38.1