Re: [PATCH v2 net-next] ethtool: ioctl: improve error checking for set_wol

[Justin Chen]

On 6/7/23 4:14 PM, Justin Chen wrote:
> The netlink version of set_wol checks for not supported wolopts and avoids
> setting wol when the correct wolopt is already set. If we do the same with
> the ioctl version then we can remove these checks from the driver layer.
>
> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
> Signed-off-by: Justin Chen <justin.chen@xxxxxxxxxxxx>
> ---
> v2
> 	- Return -EINVAL instead of -EOPNOTSUPP
>
>   net/ethtool/ioctl.c | 14 ++++++++++++--
>   1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
> index 6bb778e10461..37b582225854 100644
> --- a/net/ethtool/ioctl.c
> +++ b/net/ethtool/ioctl.c
> @@ -1436,15 +1436,25 @@ static int ethtool_get_wol(struct net_device *dev, char __user *useraddr)
>   
>   static int ethtool_set_wol(struct net_device *dev, char __user *useraddr)
>   {
> -	struct ethtool_wolinfo wol;
> +	struct ethtool_wolinfo wol, cur_wol;
>   	int ret;
>   
> -	if (!dev->ethtool_ops->set_wol)
> +	if (!dev->ethtool_ops->get_wol || !dev->ethtool_ops->set_wol)
>   		return -EOPNOTSUPP;
>   
> +	memset(&cur_wol, 0, sizeof(struct ethtool_wolinfo));
> +	cur_wol.cmd = ETHTOOL_GWOL;
> +	dev->ethtool_ops->get_wol(dev, &cur_wol);
> +
>   	if (copy_from_user(&wol, useraddr, sizeof(wol)))
>   		return -EFAULT;
>   
> +	if (wol.wolopts & ~cur_wol.supported)
> +		return -EINVAL;
> +
> +	if (wol.wolopts == cur_wol.wolopts)
> +		return 0;
> +
>   	ret = dev->ethtool_ops->set_wol(dev, &wol);
>   	if (ret)
>   		return ret;

Was thinking more about this patch. I realized we don't account for the 
different sopass case.
# ethtool -s eth0 wol s sopass 11:22:33:44:55:66
# ethtool -s eth0 wol s sopass 22:44:55:66:77:88

For this case, the second sopass values won't be stored.

Can you drop this patch? I will submit another version.

Thanks,
Justin

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