Re: [PATCH net-next 1/3] ynl: netdev: drop unnecessary enum-as-flags

[Jakub Kicinski <kuba@kernel.org>]

On Mon, 16 Oct 2023 13:43:07 -0400 Willem de Bruijn wrote:
> > Jakub, Willem hit an issue with this commit when running cli.py:
> >
> > ./cli.py --spec $KDIR/Documentation/netlink/specs/netdev.yaml --dump dev-get --json='{"ifindex": 12}'
> >
> > Traceback (most recent call last):
> >   File "/usr/local/google/home/sdf/net-next/tools/net/ynl/./cli.py", line 60, in <module>
> >     main()
> >   File "/usr/local/google/home/sdf/net-next/tools/net/ynl/./cli.py", line 51, in main
> >     reply = ynl.dump(args.dump, attrs)
> >             ^^^^^^^^^^^^^^^^^^^^^^^^^^
> >   File "/usr/local/google/home/sdf/net-next/tools/net/ynl/lib/ynl.py", line 729, in dump
> >     return self._op(method, vals, [], dump=True)
> >            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >   File "/usr/local/google/home/sdf/net-next/tools/net/ynl/lib/ynl.py", line 714, in _op
> >     rsp_msg = self._decode(decoded.raw_attrs, op.attr_set.name)
> >               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >   File "/usr/local/google/home/sdf/net-next/tools/net/ynl/lib/ynl.py", line 540, in _decode
> >     decoded = self._decode_enum(decoded, attr_spec)
> >               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >   File "/usr/local/google/home/sdf/net-next/tools/net/ynl/lib/ynl.py", line 486, in _decode_enum
> >     value = enum.entries_by_val[raw].name
> >             ~~~~~~~~~~~~~~~~~~~^^^^^
> > KeyError: 127  
> 
> Indeed. The field is now interpreted as a value rather than a bitmap.
> 
> More subtly, even for requests that do not fail, all my devices now
> incorrectly report to support xdp feature timestamp, because that is
> enum 0.

Sorry about that. This should fix it, right?

diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index 13c4b019a881..28ac35008e65 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -474,7 +474,7 @@ genl_family_name_to_id = None
 
     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']:
+        if enum.type == 'flags' or attr_spec.get('enum-as-flags', False):
             i = 0
             value = set()
             while raw: