MBO: Prevent association to APs that explicitly disallow this

Prevent association to MBO APs that have association disallowed
attribute in MBO IE in Beacon or Probe Response frames.

Signed-off-by: David Spinadel <david.spinadel@intel.com>

wpa_supplicant/events.c

@@ -827,6 +827,9 @@ static struct wpa_ssid * wpa_scan_res_match(struct wpa_supplicant *wpa_s,
 	const u8 *ie;
 	struct wpa_ssid *ssid;
 	int osen;
+#ifdef CONFIG_MBO
+	const u8 *assoc_disallow;
+#endif /* CONFIG_MBO */
 
 	ie = wpa_bss_get_vendor_ie(bss, WPA_IE_VENDOR_TYPE);
 	wpa_ie_len = ie ? ie[1] : 0;
@@ -1064,6 +1067,16 @@ static struct wpa_ssid * wpa_scan_res_match(struct wpa_supplicant *wpa_s,
 				(unsigned int) diff.usec);
 			continue;
 		}
+#ifdef CONFIG_MBO
+		assoc_disallow = wpas_mbo_get_bss_attr(
+			bss, MBO_ATTR_ID_ASSOC_DISALLOW);
+		if (assoc_disallow && assoc_disallow[1] >= 1) {
+			wpa_dbg(wpa_s, MSG_DEBUG,
+				"   skip - MBO association disallowed (reason %u)",
+				assoc_disallow[2]);
+			continue;
+		}
+#endif /* CONFIG_MBO */
 
 		/* Matching configuration found */
 		return ssid;

wpa_supplicant/mbo.c

@@ -36,6 +36,24 @@ static int wpas_mbo_validate_non_pref_chan(u8 oper_class, u8 chan, u8 reason)
 }
 
 
+const u8 * wpas_mbo_get_bss_attr(struct wpa_bss *bss, enum mbo_attr_id attr)
+{
+	const u8 *mbo, *end;
+
+	if (!bss)
+		return NULL;
+
+	mbo = wpa_bss_get_vendor_ie(bss, MBO_IE_VENDOR_TYPE);
+	if (!mbo)
+		return NULL;
+
+	end = mbo + 2 + mbo[1];
+	mbo += MBO_IE_HEADER;
+
+	return get_ie(mbo, end - mbo, attr);
+}
+
+
 static void wpas_mbo_non_pref_chan_attr_body(struct wpa_supplicant *wpa_s,
 					     struct wpabuf *mbo,
 					     u8 start, u8 end)

wpa_supplicant/wpa_supplicant_i.h

@@ -1144,6 +1144,7 @@ void wpas_rrm_handle_link_measurement_request(struct wpa_supplicant *wpa_s,
 
 /* MBO functions */
 int wpas_mbo_ie(struct wpa_supplicant *wpa_s, u8 *buf, size_t len);
+const u8 * wpas_mbo_get_bss_attr(struct wpa_bss *bss, enum mbo_attr_id attr);
 int wpas_mbo_update_non_pref_chan(struct wpa_supplicant *wpa_s,
 				  const char *non_pref_chan);
 void wpas_mbo_scan_ie(struct wpa_supplicant *wpa_s, struct wpabuf *ie);