Re: [RFC PATCH net-next v3 15/21] ethtool: provide link settings and link modes in GET_SETTINGS request

[Florian Fainelli <f.fainelli@gmail.com>]

On 2/18/2019 10:22 AM, Michal Kubecek wrote:
> Implement GET_SETTINGS netlink request to get link settings and link mode
> information provided by ETHTOOL_GLINKSETTINGS ioctl command.
> 
> The information is divided into two parts: supported, advertised and peer
> advertised link modes when ETH_SETTINGS_IM_LINKMODES flag is set in the
> request and other settings when ETH_SETTINGS_IM_LINKINFO is set.
> 
> Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
> ---

[snip]

> +#define ETH_SETTINGS_IM_LINKINFO		0x01
> +#define ETH_SETTINGS_IM_LINKMODES		0x02
> +
> +#define ETH_SETTINGS_IM_ALL			0x03

You could define ETH_SETTINGS_IM_ALL as:

#define ETH_SETTING_IM_ALL		\
		(ETH_SETTINGS_IM_LINKINFO |
		 ETH_SETTINGS_IM_LINMODES)

that would scale better IMHO, especially given that you have to keep
bumping that mask with new bits in subsequent patches.

[snip]

> +	if (tb[ETHA_SETTINGS_INFOMASK])
> +		req_info->req_mask = nla_get_u32(tb[ETHA_SETTINGS_INFOMASK]);
> +	if (tb[ETHA_SETTINGS_COMPACT])
> +		req_info->compact = true;
> +	if (req_info->req_mask == 0)
> +		req_info->req_mask = ETH_SETTINGS_IM_ALL;

What if userland is newer than the kernel and specifies a req_mask with
bits set that you don't support? Should not you always do an &
ETH_SETTINGS_IM_ALL here?

[snip]
-- 
Florian