Subject: Re: [PATCH net-next 1/3] tools: ynl: cli: Add --list-attrs option to show operation attributes

From: Donald Hunter <[email-masked]>
Date: Mon, 17 Nov 2025 15:56:17 +0000

Gal Pressman <[email-masked]> writes:

> Add a --list-attrs option to the YNL CLI that displays information about
> netlink operations, including request and reply attributes.
> This eliminates the need to manually inspect YAML spec files to
> determine the JSON structure required for operations, or understand the
> structure of the reply.

Thanks for the contribution, it's been on my wishlist for a while.

[...]

> +    def print_attr_list(attr_names, attr_set):
> +        """Print a list of attributes with their types and documentation."""
> +        for attr_name in attr_names:
> +            if attr_name in attr_set.attrs:
> +                attr = attr_set.attrs[attr_name]
> +                attr_info = f'  - {attr_name}: {attr.type}'
> +                if 'enum' in attr.yaml:
> +                    attr_info += f" (enum: {attr.yaml['enum']})"
> +                if attr.yaml.get('doc'):
> +                    doc_text = textwrap.indent(attr.yaml['doc'], '    ')
> +                    attr_info += f"\n{doc_text}"
> +                print(attr_info)
> +            else:
> +                print(f'  - {attr_name}')

Does this line execute? I think this scenario indicates a malformed
spec that would fail codegen.

> +    def print_mode_attrs(mode, mode_spec, attr_set, print_request=True):
> +        """Print a given mode (do/dump/event/notify)."""
> +        mode_title = mode.capitalize()
> +
> +        if print_request and 'request' in mode_spec and 'attributes' in mode_spec['request']:
> +            print(f'\n{mode_title} request attributes:')
> +            print_attr_list(mode_spec['request']['attributes'], attr_set)
> +
> +        if 'reply' in mode_spec and 'attributes' in mode_spec['reply']:
> +            print(f'\n{mode_title} reply attributes:')
> +            print_attr_list(mode_spec['reply']['attributes'], attr_set)
> +
> +        if 'attributes' in mode_spec:
> +            print(f'\n{mode_title} attributes:')
> +            print_attr_list(mode_spec['attributes'], attr_set)
> +
> +        if 'mcgrp' in mode_spec:
> +                print(f"Multicast group: {op.yaml['mcgrp']}")
> +
>      if args.list_ops:
>          for op_name, op in ynl.ops.items():
>              print(op_name, " [", ", ".join(op.modes), "]")
> @@ -135,6 +172,24 @@ def main():
>          for op_name, op in ynl.msgs.items():
>              print(op_name, " [", ", ".join(op.modes), "]")
>  
> +    if args.list_attrs:
> +        op = ynl.msgs.get(args.list_attrs)
> +        if not op:
> +            print(f'Operation {args.list_attrs} not found')
> +            exit(1)
> +
> +        print(f'Operation: {op.name}')
> +
> +        for mode in ['do', 'dump', 'event']:
> +            if mode in op.yaml:
> +                print_mode_attrs(mode, op.yaml[mode], op.attr_set, True)
> +
> +        if 'notify' in op.yaml:
> +            mode_spec = op.yaml['notify']
> +            ref_spec = ynl.msgs.get(mode_spec).yaml.get('do')
> +            if ref_spec:
> +                print_mode_attrs(mode, ref_spec, op.attr_set, False)

I guess mode is set to 'event' after the for loop. I'd prefer to not
see it used outside the loop, and just use literal 'event' here.

> +
>      try:
>          if args.do:
>              reply = ynl.do(args.do, attrs, args.flags)