Enable clearing of sink scratchpad

According to the gateway to backend API, scratchpad should be cleared if
the scratchpad bytes are not present in the upload scratchpad request.

This change enables clearing of the scratchpad in order to make it
easier to test OTAP functionality of the gateway.

Additionally, in order to prevent accidental clearing of the scratchpad,
the clearing is only done if the scratchpad bytes field is missing (i.e.
it should fail if an empty file is uploaded).

python_transport/wirepas_gateway/dbus/sink_manager.py

@@ -499,6 +499,35 @@ def upload_scratchpad(self, seq, file):
 
         return ret
 
+    def clear_local_scratchpad(self):
+        ret = wmm.GatewayResultCode.GW_RES_OK
+        restart = False
+        try:
+            # Stop the stack if not already stopped
+            if self.proxy.StackStatus == 0:
+                self.proxy.SetStackState(False)
+                restart = True
+        except GLib.Error:
+            logging.error("Sink in invalid state")
+            return wmm.GatewayResultCode.GW_RES_INVALID_SINK_STATE
+
+        try:
+            self.proxy.ClearLocalScratchpad()
+            logging.info("Scratchpad cleared on sink %s", self.sink_id)
+        except GLib.Error as e:
+            ret = ReturnCode.error_from_dbus_exception(str(e))
+            logging.error("Cannot clear local scratchpad: %s", ret.name)
+
+        if restart:
+            try:
+                # Restart sink if we stopped it for this request
+                self.proxy.SetStackState(True)
+            except GLib.Error as e:
+                ret = ReturnCode.error_from_dbus_exception(str(e))
+                logging.error("Could not restore sink's state: %s", ret.name)
+
+        return ret
+
     def set_target_scratchpad(self, action, target_seq, target_crc, param):
         ret = wmm.GatewayResultCode.GW_RES_OK
 

python_transport/wirepas_gateway/transport_service.py

@@ -288,8 +288,8 @@ def _set_status(self):
         # Publish only if something has changed
         if self._last_status_config is not None and \
             self._last_status_config == configs:
-                logging.info("No new status to publish")
-                return
+            logging.info("No new status to publish")
+            return
 
         event_online = wmm.StatusEvent(
                             self.gw_id,
@@ -737,7 +737,10 @@ def _on_otap_upload_scratchpad_request_received(self, client, userdata, message)
 
         sink = self.sink_manager.get_sink(request.sink_id)
         if sink is not None:
-            res = sink.upload_scratchpad(request.seq, request.scratchpad)
+            if request.scratchpad is None:
+                res = sink.clear_local_scratchpad()
+            else:
+                res = sink.upload_scratchpad(request.seq, request.scratchpad)
         else:
             res = wmm.GatewayResultCode.GW_RES_INVALID_SINK_ID
 

sink_service/source/otap.c

@@ -113,6 +113,37 @@ static int upload_scratchpad(sd_bus_message * m, void * userdata, sd_bus_error *
     return sd_bus_reply_method_return(m, "");
 }
 
+/**
+ * \brief   Clear local scratchpad
+ * \param   ... (from sd_bus function signature)
+ */
+static int clear_local_scratchpad(sd_bus_message * m, void * userdata, sd_bus_error * error)
+{
+    LOGD("Will clear local scratchpad\n");
+
+    const app_res_e res = WPC_clear_local_scratchpad();
+    if (res != APP_RES_OK)
+    {
+        LOGE("Cannot clear local scratchpad\n");
+        SET_WPC_ERROR(error, "WPC_clear_local_scratchpad", res);
+        return -EINVAL;
+    }
+
+    /* Scratchpad cleared, update parameters values exposed on bus */
+    initialize_unmodifiable_variables();
+
+    LOGD("Stored status:%08X, stored type:%08X\n", m_sink_otap.stored_status, m_sink_otap.stored_type);
+
+    /* Do some sanity check: Do not generate error for that */
+    if (m_sink_otap.stored_len != 0)
+    {
+        LOGE("Scratchpad is not cleared correctly (size not zero) %d", m_sink_otap.stored_len);
+    }
+
+    /* Reply with the response */
+    return sd_bus_reply_method_return(m, "");
+}
+
 /**
  * \brief   Update local scratchpad
  * \param   ... (from sd_bus function signature)
@@ -245,6 +276,7 @@ static const sd_bus_vtable otap_vtable[] =
      *  ay -> byte array containing the scratchpad to upload
      */
     SD_BUS_METHOD("UploadScratchpad","yay", "", upload_scratchpad, SD_BUS_VTABLE_UNPRIVILEGED),
+    SD_BUS_METHOD("ClearLocalScratchpad", "", "", clear_local_scratchpad, SD_BUS_VTABLE_UNPRIVILEGED),
     SD_BUS_METHOD("SetTargetScratchpad","yqyy", "b", set_target_scratchpad, SD_BUS_VTABLE_UNPRIVILEGED),
     SD_BUS_METHOD("GetTargetScratchpad", "", "yqyy", get_target_scratchpad, SD_BUS_VTABLE_UNPRIVILEGED),