Subject: Re: [patch net-next rfc 7/7] net: rtnetlink: add possibility to use alternative names as message handle

From: Jakub Kicinski <[email-masked]>
Date: Fri, 19 Jul 2019 20:59:27 -0700

On Fri, 19 Jul 2019 13:00:29 +0200, Jiri Pirko wrote:
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index 1fa30d514e3f..68ad12a7fc4d 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -1793,6 +1793,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
>  	[IFLA_MAX_MTU]		= { .type = NLA_U32 },
>  	[IFLA_ALT_IFNAME_MOD]	= { .type = NLA_STRING,
>  				    .len = ALTIFNAMSIZ - 1 },
> +	[IFLA_ALT_IFNAME]	= { .type = NLA_STRING,
> +				    .len = ALTIFNAMSIZ - 1 },

What's the disadvantage of just letting IFLA_IFNAME to get longer 
on input? Is it just that the handling would be asymmetrical?

>  };
>  
>  static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {