Subject: Re: [PATCH net-next v4 3/7] tools: ynl: Add struct attr decoding to ynl

From: Jakub Kicinski <[email-masked]>
Date: Fri, 24 Mar 2023 20:42:40 -0700

On Fri, 24 Mar 2023 19:18:56 +0000 Donald Hunter wrote:
> diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
> index b635d147175c..af1d6d380035 100644
> --- a/tools/net/ynl/lib/ynl.py
> +++ b/tools/net/ynl/lib/ynl.py
> @@ -102,6 +102,16 @@ class NlAttr:
>          format, _ = self.type_formats[type]
>          return list({ x[0] for x in struct.iter_unpack(format, self.raw) })
>  
> +    def as_struct(self, members):
> +        value = dict()
> +        offset = 0
> +        for m in members:

Maybe add a TODO here for string and binary?

> +            format, size = self.type_formats[m.type]
> +            decoded = struct.unpack_from(format, self.raw, offset)
> +            offset += size
> +            value[m.name] = decoded[0]
> +        return value
> +
>      def __repr__(self):
>          return f"[type:{self.type} len:{self._len}] {self.raw}"
>  
> @@ -373,8 +383,11 @@ class YnlFamily(SpecFamily):
>          rsp[attr_spec['name']] = value
>  
>      def _decode_binary(self, attr, attr_spec):
> +        struct_name = attr_spec.get('struct')
>          sub_type = attr_spec.get('sub-type')

Could you add these as fields in class SpecAttr, like is_multi
and access the fields here instead of the get()s?

> -        if sub_type:
> +        if struct_name:
> +            decoded = attr.as_struct(self.consts[struct_name])
> +        elif sub_type:
>              decoded = attr.as_c_array(sub_type)
>          else:
>              decoded = attr.as_bin()