dbus: Add D-Bus signal for PSK mismatch heuristics

As a workup action during disassociation, wpa_supplicant checks if the
disconnection could have been caused by PSK mismatch during WPA 4-way
handshake with function could_be_psk_mismatch() in event.c. A MSG_INFO
message will be sent on the control interface when there could be a PSK
mismatch, and this heuristic can be useful to indicate if the
disconnection is caused by a wrong passphrase provided by the user.
Here, propagate a new D-Bus signal 'PskMismatch' to notify other
applicantions.

Signed-off-by: Yichen Yu <yichenyu@chromium.org>

doc/dbus.doxygen

@@ -1329,6 +1329,11 @@ fi.w1.wpa_supplicant1.CreateInterface.
       <li>
 	<h3>InterworkingSelectDone ( )</h3>
       </li>
+
+      <li>
+	<h3>PskMismatch ( )</h3>
+	<p>A possible PSK mismatch is identified.</p>
+      </li>
     </ul>
 
 

wpa_supplicant/dbus/dbus_new.c

@@ -1102,6 +1102,29 @@ void wpas_dbus_signal_eap_status(struct wpa_supplicant *wpa_s,
 }
 
 
+void wpas_dbus_signal_psk_mismatch(struct wpa_supplicant *wpa_s)
+{
+	struct wpas_dbus_priv *iface;
+	DBusMessage *msg;
+
+	iface = wpa_s->global->dbus;
+
+	/* Do nothing if the control interface is not turned on */
+	if (!iface || !wpa_s->dbus_new_path)
+		return;
+
+	msg = dbus_message_new_signal(wpa_s->dbus_new_path,
+				      WPAS_DBUS_NEW_IFACE_INTERFACE,
+				      "PskMismatch");
+	if (!msg)
+		return;
+
+	dbus_connection_send(iface->con, msg, NULL);
+
+	dbus_message_unref(msg);
+}
+
+
 /**
  * wpas_dbus_signal_sta - Send a station related event signal
  * @wpa_s: %wpa_supplicant network interface data

wpa_supplicant/dbus/dbus_new.h

@@ -254,6 +254,7 @@ void wpas_dbus_signal_preq(struct wpa_supplicant *wpa_s,
 			   const u8 *ie, size_t ie_len, u32 ssi_signal);
 void wpas_dbus_signal_eap_status(struct wpa_supplicant *wpa_s,
 				 const char *status, const char *parameter);
+void wpas_dbus_signal_psk_mismatch(struct wpa_supplicant *wpa_s);
 void wpas_dbus_signal_sta_authorized(struct wpa_supplicant *wpa_s,
 				     const u8 *sta);
 void wpas_dbus_signal_sta_deauthorized(struct wpa_supplicant *wpa_s,
@@ -585,6 +586,10 @@ static inline void wpas_dbus_signal_eap_status(struct wpa_supplicant *wpa_s,
 {
 }
 
+static inline void wpas_dbus_signal_psk_mismatch(struct wpa_supplicant *wpa_s)
+{
+}
+
 static inline
 void wpas_dbus_signal_sta_authorized(struct wpa_supplicant *wpa_s,
 				     const u8 *sta)

wpa_supplicant/events.c

@@ -3977,6 +3977,7 @@ static void wpa_supplicant_event_disassoc_finish(struct wpa_supplicant *wpa_s,
 		if (wpas_p2p_4way_hs_failed(wpa_s) > 0)
 			return; /* P2P group removed */
 		wpas_auth_failed(wpa_s, "WRONG_KEY", prev_pending_bssid);
+		wpas_notify_psk_mismatch(wpa_s);
 #ifdef CONFIG_DPP2
 		wpas_dpp_send_conn_status_result(wpa_s,
 						 DPP_STATUS_AUTH_FAILURE);

wpa_supplicant/notify.c

@@ -877,6 +877,12 @@ void wpas_notify_eap_error(struct wpa_supplicant *wpa_s, int error_code)
 }
 
 
+void wpas_notify_psk_mismatch(struct wpa_supplicant *wpa_s)
+{
+	wpas_dbus_signal_psk_mismatch(wpa_s);
+}
+
+
 void wpas_notify_network_bssid_set_changed(struct wpa_supplicant *wpa_s,
 					   struct wpa_ssid *ssid)
 {

wpa_supplicant/notify.h

@@ -143,6 +143,7 @@ void wpas_notify_preq(struct wpa_supplicant *wpa_s,
 void wpas_notify_eap_status(struct wpa_supplicant *wpa_s, const char *status,
 			    const char *parameter);
 void wpas_notify_eap_error(struct wpa_supplicant *wpa_s, int error_code);
+void wpas_notify_psk_mismatch(struct wpa_supplicant *wpa_s);
 void wpas_notify_network_bssid_set_changed(struct wpa_supplicant *wpa_s,
 					   struct wpa_ssid *ssid);
 void wpas_notify_network_type_changed(struct wpa_supplicant *wpa_s,