[PATCH 01/10] wifi: nl80211: split helper function from nl80211_put_iface_combinations

[Johannes Berg]

On Thu, 2024-06-20 at 13:11 +0200, Felix Fietkau wrote:
> 
> +static int nl80211_put_ifcomb_data(struct sk_buff *msg, bool large, int idx,
> +				   const struct ieee80211_iface_combination *c)
>  {
> -	struct nlattr *nl_combis;
> -	int i, j;
> +	struct nlattr *nl_combi, *nl_limits;
> +	int i;
>  
> -	nl_combis = nla_nest_start_noflag(msg,
> -					  NL80211_ATTR_INTERFACE_COMBINATIONS);
> -	if (!nl_combis)
> +	nl_combi = nla_nest_start_noflag(msg, idx);
> +	if (!nl_combi)
>  		goto nla_put_failure;

Not sure why the diff looks so much different here between my git and
yours, but anyway ...

Even if it's ugly here, I do think you should add an argument to the
function

	..., u16 nested

pass 0 for the existing user, and NLA_F_NESTED for the later new users,
and use

	nla_nest_start_noflag(msg, idx | nested);

etc. for all the nla_nest_start_noflag() calls in this function. I
really don't want to propagate the _noflag() API further.

(The above was the simplest I could come up with, maybe you can find a
better solution, but callikng nla_nest_start() conditionally seemed
worse)

johannes