Re: [RFC PATCH net-next 1/7] net: ethtool: netlink: introduce ethnl_update_bool()

Michal Kubecek
2022-08-17T11:27:39Z

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On Wed, Aug 17, 2022 at 01:29:14AM +0300, Vladimir Oltean wrote:
> For a reason I can't really understand, ethnl_update_bool32() exists,
> but the plain function that operates on a boolean value kept in an
> actual u8 netlink attribute doesn't.

I can explain that: at the moment these helpers were introduced, only
members of traditional structures shared with ioctl interface were
updated and all attributes which were booleans logically were
represented as u32 in them so that no other helper was needed back then.

> Introduce it; it's needed for
> things like verify-disabled for the MAC merge configuration.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
> net/ethtool/netlink.h | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
> index c0d587611854..1653fd2cf0cf 100644
> --- a/net/ethtool/netlink.h
> +++ b/net/ethtool/netlink.h
> @@ -111,6 +111,32 @@ static inline void ethnl_update_u8(u8 *dst, const struct nlattr *attr,
> *mod = true;
> }
>
> +/**
> + * ethnl_update_bool() - update bool from NLA_U8 attribute
> + * @dst: value to update
> + * @attr: netlink attribute with new value or null
> + * @mod: pointer to bool for modification tracking
> + *
> + * Use the u8 value from NLA_U8 netlink attribute @attr to set bool variable
> + * pointed to by @dst to false (if zero) or 1 (if not); do nothing if @attr is
^ true

Looks good otherwise.

Michal

> + * null. Bool pointed to by @mod is set to true if this function changed the
> + * logical value of *dst, otherwise it is left as is.
> + */
> +static inline void ethnl_update_bool(bool *dst, const struct nlattr *attr,
> + bool *mod)
> +{
> + u8 val;
> +
> + if (!attr)
> + return;
> + val = !!nla_get_u8(attr);
> + if (*dst == val)
> + return;
> +
> + *dst = val;
> + *mod = true;
> +}
> +
> /**
> * ethnl_update_bool32() - update u32 used as bool from NLA_U8 attribute
> * @dst: value to update
> --
> 2.34.1
>

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