Subject: Re: [PATCH net-next 1/2] ynl: rename array-nest to indexed-array

From: Jakub Kicinski <[email-masked]>
Date: Tue, 26 Mar 2024 20:46:10 -0700

On Tue, 26 Mar 2024 14:37:27 +0800 Hangbin Liu wrote:
> diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
> index 5fa7957f6e0f..7239e673a28a 100644
> --- a/tools/net/ynl/lib/ynl.py
> +++ b/tools/net/ynl/lib/ynl.py
> @@ -686,8 +686,9 @@ class YnlFamily(SpecFamily):
>                  decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
>                  if 'enum' in attr_spec:
>                      decoded = self._decode_enum(decoded, attr_spec)
> -            elif attr_spec["type"] == 'array-nest':
> -                decoded = self._decode_array_nest(attr, attr_spec)
> +            elif attr_spec["type"] == 'indexed-array' and 'sub-type' in attr_spec:
> +                if attr_spec["sub-type"] == 'nest':
> +                    decoded = self._decode_array_nest(attr, attr_spec)

We need to make sure somehow cleanly that we treat unknown subtype the
same we would treat unknown type. In this elif ladder we have:

            else:
                if not self.process_unknown:
                    raise Exception(f'Unknown {attr_spec["type"]} with name {attr_spec["name"]}')

So we should raise an exception if sub-type != nest.

>              elif attr_spec["type"] == 'bitfield32':
>                  value, selector = struct.unpack("II", attr.raw)
>                  if 'enum' in attr_spec:
> diff --git a/tools/net/ynl/ynl-gen-c.py b/tools/net/ynl/ynl-gen-c.py
> index 6b7eb2d2aaf1..8d5ec5449648 100755
> --- a/tools/net/ynl/ynl-gen-c.py
> +++ b/tools/net/ynl/ynl-gen-c.py
> @@ -838,8 +838,9 @@ class AttrSet(SpecAttrSet):
>              t = TypeBitfield32(self.family, self, elem, value)
>          elif elem['type'] == 'nest':
>              t = TypeNest(self.family, self, elem, value)
> -        elif elem['type'] == 'array-nest':
> -            t = TypeArrayNest(self.family, self, elem, value)
> +        elif elem['type'] == 'indexed-array' and 'sub-type' in elem:
> +            if elem["sub-type"] == 'nest':
> +                t = TypeArrayNest(self.family, self, elem, value)

same here

>          elif elem['type'] == 'nest-type-value':
>              t = TypeNestTypeValue(self.family, self, elem, value)
>          else:
> @@ -1052,8 +1053,9 @@ class Family(SpecFamily):
>                      if nested in self.root_sets:
>                          raise Exception("Inheriting members to a space used as root not supported")
>                      inherit.update(set(spec['type-value']))
> -                elif spec['type'] == 'array-nest':
> -                    inherit.add('idx')
> +                elif spec['type'] == 'indexed-array' and 'sub-type' in spec:
> +                    if spec["sub-type"] == 'nest':
> +                        inherit.add('idx')

Here you don't have to match on sub-type, all indexed-arrays will have
an idx (index) member.

>                  self.pure_nested_structs[nested].set_inherited(inherit)
>  
>          for root_set, rs_members in self.root_sets.items():
> @@ -1616,9 +1618,10 @@ def _multi_parse(ri, struct, init_lines, local_vars):
>      multi_attrs = set()
>      needs_parg = False
>      for arg, aspec in struct.member_list():
> -        if aspec['type'] == 'array-nest':
> -            local_vars.append(f'const struct nlattr *attr_{aspec.c_name};')
> -            array_nests.add(arg)
> +        if aspec['type'] == 'indexed-array' and 'sub-type' in aspec:
> +            if aspec["sub-type"] == 'nest':
> +                local_vars.append(f'const struct nlattr *attr_{aspec.c_name};')
> +                array_nests.add(arg)

Please also update the info about nested-array in
Documentation/userspace-api/netlink/genetlink-legacy.rst
-- 
pw-bot: cr