Re: [PATCH net-next 1/6] flow_offload: add flow_rule_no_unsupp_control_flags()

[Louis Peens <louis.peens@corigine.com>]

On Mon, Apr 08, 2024 at 01:09:19PM +0000, Asbjørn Sloth Tønnesen wrote:
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> 
> This helper can be used by drivers to check for the
> presence of unsupported control flags.
> 
> It mirrors the existing check done in sfc:
>   drivers/net/ethernet/sfc/tc.c +276
> 
> This is aimed at drivers, which implements some control flags.
> 
> This should also be used by drivers that implement all
> current flags, so that future flags will be unsupported
> by default.
> 
> Only compile-tested.
> 
> Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
> ---
>  include/net/flow_offload.h | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
> index 314087a5e1818..c1317b14da08c 100644
> --- a/include/net/flow_offload.h
> +++ b/include/net/flow_offload.h
> @@ -449,6 +449,28 @@ static inline bool flow_rule_match_key(const struct flow_rule *rule,
>         return dissector_uses_key(rule->match.dissector, key);
>  }
> 
> +/**
> + * flow_rule_no_unsupp_control_flags() - check for unsupported control flags
> + * @supp_flags: flags supported by driver
> + * @flags: flags present in rule
> + * @extack: The netlink extended ACK for reporting errors.
> + *
> + * Returns true if only supported control flags are set, false otherwise.
> + */
> +static inline bool flow_rule_no_unsupp_control_flags(const u32 supp_flags,
> +                                                    const u32 flags,
> +                                                    struct netlink_ext_ack *extack)
Thanks for the change Asbjørn, I like the series in general. I do have
some nitpicking with the naming of this function, the double negative
makes it a bit hard to read. Especially where it gets used, where it
then reads as:
    'if not no unsupported'

I think something like:
    'if not supported'
or
    'if unsupported'

will read much better - personally I think the first option is the best,
otherwise you might end up with 'if not unsupported', which is also
weird.

Some possible suggestions I can think of:
    flow_rule_control_flags_is_supp()
    flow_rule_is_supp_control_flags()
    flow_rule_check_supp_control_flags()

or perhaps some even better variant of this. I hope it's not just me, if
that's the case please feel free to ignore.