Re: [PATCH v4 1/2] nl80211: Add FILS discovery support

[Johannes Berg <johannes@xxxxxxxxxxxxxxxx>]

On Wed, 2020-06-17 at 22:04 -0700, Aloka Dixit wrote:
> + * @NL80211_FILS_DISCOVERY_TMPL: Optional FILS discovery template.
> + *	It has contents of IEEE Std 802.11ai-2016 9.6.8.36 FILS discovery frame
> + *	(Figure 9-687a).

Is that

"It has (contents of ... FILS discovery frame) ..."

or

"It has contents of (... FILS discovery frame) ..."?

I mean, is that with or without headers? The wording doesn't seem
entirely clear to me.

OTOH, if it's with headers, how could it be optional? In fact, either
way, how is it optional?

> +static int nl80211_parse_fils_discovery(struct nlattr *attrs,
> +					struct cfg80211_ap_settings *params)
> +{
> +	struct nlattr *tmpl;
> +	struct nlattr *tb[NL80211_FILS_DISCOVERY_MAX + 1];
> +	int ret;
> +	struct cfg80211_fils_discovery *fd = &params->fils_discovery;
> +
> +	ret = nla_parse_nested(tb, NL80211_FILS_DISCOVERY_MAX, attrs,
> +			       fils_discovery_policy, NULL);
> +	if (ret)
> +		return ret;
> +
> +	if (!tb[NL80211_FILS_DISCOVERY_INT_MIN] ||
> +	    !tb[NL80211_FILS_DISCOVERY_INT_MAX])
> +		return -EINVAL;
> +
> +	fd->min_interval = nla_get_u32(tb[NL80211_FILS_DISCOVERY_INT_MIN]);
> +	fd->max_interval = nla_get_u32(tb[NL80211_FILS_DISCOVERY_INT_MAX]);
> +
> +	tmpl = tb[NL80211_FILS_DISCOVERY_TMPL];
> +	if (tmpl) {
> +		fd->tmpl = nla_data(tmpl);
> +		fd->tmpl_len = nla_len(tmpl);

And if it's with headers, it should have some kind of minimum length
too? You've only put a maximum length into the policy.

(Which reminds me I wanted to have an NLA_POLICY_RANGE(NLA_BINARY, min,
max) but haven't done that yet ...)

johannes