[PATCH 08/13] wifi: cfg80211: Refactor the iface combination iteration helper function

[Johannes Berg]

On Thu, 2024-03-28 at 12:59 +0530, Karthikeyan Periyasamy wrote:
> 
> +static int
> +cfg80211_validate_iface_comb_limits(struct wiphy *wiphy,
> +				    struct iface_combination_params *params,
> +				    const struct ieee80211_iface_combination *c,
> +				    u16 num_interfaces, u32 *all_iftypes)
> +{
> +	struct ieee80211_iface_limit *limits;
> +	int ret = 0;

That initialization is useless.

> +
> +	if (num_interfaces > c->max_interfaces)
> +		return -EINVAL;
> +
> +	if (params->num_different_channels > c->num_different_channels)
> +		return -EINVAL;
> +
> +	limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
> +			 GFP_KERNEL);
> +	if (!limits)
> +		return -ENOMEM;
> +
> +	ret = cfg80211_validate_iface_limits(wiphy,
> +					     params->iftype_num,
> +					     limits,
> +					     c->n_limits,
> +					     all_iftypes);
> +
> +	kfree(limits);
> +
> +	return ret;
> +}
> +
> +static u16 cfg80211_get_iftype_info(struct wiphy *wiphy,
> +				    const int iftype_num[NUM_NL80211_IFTYPES],
> +				    u32 *used_iftypes)
> +{
> +	enum nl80211_iftype iftype;
> +	u16 num_interfaces = 0;
> +

This should probably set *used_iftypes = 0.

> +	for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
> +		num_interfaces += iftype_num[iftype];
> +		if (iftype_num[iftype] > 0 &&
> +		    !cfg80211_iftype_allowed(wiphy, iftype, 0, 1))
> +			*used_iftypes |= BIT(iftype);

and that could really use a rewrite like

		if (!iftype_num[iftype])
			continue;

		num_interfaces += ...

		if (!allowed...)
			*used_iftypes |= ...;

I'd say.

>  	for (i = 0; i < wiphy->n_iface_combinations; i++) {
>  		const struct ieee80211_iface_combination *c;
> -		struct ieee80211_iface_limit *limits;
>  		u32 all_iftypes = 0;
>  
>  		c = &wiphy->iface_combinations[i];
>  
> -		if (num_interfaces > c->max_interfaces)
> -			continue;
> -		if (params->num_different_channels > c->num_different_channels)
> +		ret = cfg80211_validate_iface_comb_limits(wiphy, params,
> +							  c, num_interfaces,
> +							  &all_iftypes);
> +		if (ret == -ENOMEM) {
> +			break;
> +		} else if (ret) {
> +			ret = 0;
>  			continue;

Seems that 'break' is equivalent to just 'return ret'? And that setting
ret = 0 seems ... strange.

> -	return 0;
> +	return ret;
>  }

And then you don't need that either which is much nicer anyway...

johannes