SME: Correctly check mode HT caps for enabling OBSS scan

Don't assume the 11g mode is always first in the list of mode (sometimes
it isn't). Traverse the array of modes and check the HT40 capability is
turned on for 11g.

Signed-hostap: Arik Nemtsov <arik@wizery.com>

wpa_supplicant/sme.c

@@ -843,6 +843,8 @@ void sme_sched_obss_scan(struct wpa_supplicant *wpa_s, int enable)
 	const u8 *ie;
 	struct wpa_bss *bss = wpa_s->current_bss;
 	struct wpa_ssid *ssid = wpa_s->current_ssid;
+	struct hostapd_hw_modes *hw_mode = NULL;
+	int i;
 
 	eloop_cancel_timeout(sme_obss_scan_timeout, wpa_s, NULL);
 	wpa_s->sme.sched_obss_scan = 0;
@@ -853,9 +855,20 @@ void sme_sched_obss_scan(struct wpa_supplicant *wpa_s, int enable)
 	    ssid->mode != IEEE80211_MODE_INFRA)
 		return; /* Not using station SME in wpa_supplicant */
 
-	if (!wpa_s->hw.modes ||
-	    !(wpa_s->hw.modes->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
-		return; /* Driver does not support HT40 */
+	if (!wpa_s->hw.modes)
+		return;
+
+	/* only HT caps in 11g mode are relevant */
+	for (i = 0; i < wpa_s->hw.num_modes; i++) {
+		hw_mode = &wpa_s->hw.modes[i];
+		if (hw_mode->mode == HOSTAPD_MODE_IEEE80211G)
+			break;
+	}
+
+	/* Driver does not support HT40 for 11g or doesn't have 11g. */
+	if (i == wpa_s->hw.num_modes || !hw_mode ||
+	    !(hw_mode->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
+		return;
 
 	if (bss == NULL || bss->freq < 2400 || bss->freq > 2500)
 		return; /* Not associated on 2.4 GHz band */