wifi: mac80211: parse BSS selectors and unknown rates

Doing so enables further checking whether we are implementing the
requested features. Also allow passing in NULL for more parameters as
they may not be needed by the caller.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250101070249.76433fd3d69f.I94e8718de26ab32282b60ae257b8c6c334b7c528@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -4628,6 +4628,7 @@ static void ieee80211_rx_mgmt_disassoc(struct ieee80211_sub_if_data *sdata,
 static void ieee80211_get_rates(struct ieee80211_supported_band *sband,
 				u8 *supp_rates, unsigned int supp_rates_len,
 				u32 *rates, u32 *basic_rates,
+				unsigned long *unknown_rates_selectors,
 				bool *have_higher_than_11mbit,
 				int *min_rate, int *min_rate_index)
 {
@@ -4637,7 +4638,7 @@ static void ieee80211_get_rates(struct ieee80211_supported_band *sband,
 		int rate = supp_rates[i] & 0x7f;
 		bool is_basic = !!(supp_rates[i] & 0x80);
 
-		if ((rate * 5) > 110)
+		if ((rate * 5) > 110 && have_higher_than_11mbit)
 			*have_higher_than_11mbit = true;
 
 		/*
@@ -4647,8 +4648,11 @@ static void ieee80211_get_rates(struct ieee80211_supported_band *sband,
 		 *	 rate flag share the same bit, they are not exactly
 		 *	 the same.
 		 */
-		if (supp_rates[i] >= (0x80 | BSS_MEMBERSHIP_SELECTOR_MIN))
+		if (is_basic && rate >= BSS_MEMBERSHIP_SELECTOR_MIN) {
+			if (unknown_rates_selectors)
+				set_bit(rate, unknown_rates_selectors);
 			continue;
+		}
 
 		for (j = 0; j < sband->n_bitrates; j++) {
 			struct ieee80211_rate *br;
@@ -4658,16 +4662,22 @@ static void ieee80211_get_rates(struct ieee80211_supported_band *sband,
 
 			brate = DIV_ROUND_UP(br->bitrate, 5);
 			if (brate == rate) {
-				*rates |= BIT(j);
-				if (is_basic)
+				if (rates)
+					*rates |= BIT(j);
+				if (is_basic && basic_rates)
 					*basic_rates |= BIT(j);
-				if ((rate * 5) < *min_rate) {
+				if (min_rate && (rate * 5) < *min_rate) {
 					*min_rate = rate * 5;
-					*min_rate_index = j;
+					if (min_rate_index)
+						*min_rate_index = j;
 				}
 				break;
 			}
 		}
+
+		/* Handle an unknown entry as if it is an unknown selector */
+		if (is_basic && unknown_rates_selectors && j == sband->n_bitrates)
+			set_bit(rate, unknown_rates_selectors);
 	}
 }
 
@@ -5142,7 +5152,8 @@ static int ieee80211_mgd_setup_link_sta(struct ieee80211_link_data *link,
 	sband = local->hw.wiphy->bands[cbss->channel->band];
 
 	ieee80211_get_rates(sband, bss->supp_rates, bss->supp_rates_len,
-			    &rates, &basic_rates, &have_higher_than_11mbit,
+			    &rates, &basic_rates, NULL,
+			    &have_higher_than_11mbit,
 			    &min_rate, &min_rate_index);
 
 	/*