Bugfix/gateway crash on incomplete ws handshake (#229)

* Properly checking for errors during websocket handshake

* Unrelated typo

* Fixed similar bug in rust client

clients/desktop/src/client/topology_control.rs

@@ -157,7 +157,7 @@ impl<T: 'static + NymTopology> TopologyRefresher<T> {
     }
 
     async fn get_current_compatible_topology(&self) -> T {
-        // note: this call makes it neccessary that `T::new()`does *not* have 'static lifetime
+        // note: this call makes it necessary that `T::new()`does *not* have 'static lifetime
         let full_topology = T::new(self.directory_server.clone()).await;
         // just filter by version and assume the validators will remove all bad behaving
         // nodes with the staking

clients/desktop/src/websocket/handler.rs

@@ -309,9 +309,13 @@ impl<T: NymTopology> Handler<T> {
 
     // consume self to make sure `drop` is called after this is done
     pub(crate) async fn handle_connection(mut self, socket: TcpStream) {
-        let ws_stream = accept_async(socket)
-            .await
-            .expect("error while performing the websocket handshake");
+        let ws_stream = match accept_async(socket).await {
+            Ok(ws_stream) => ws_stream,
+            Err(err) => {
+                warn!("error while performing the websocket handshake - {:?}", err);
+                return;
+            }
+        };
         self.socket = Some(ws_stream);
 
         let (reconstructed_sender, reconstructed_receiver) = mpsc::unbounded();

gateway/src/node/client_handling/websocket/connection_handler.rs

@@ -74,19 +74,24 @@ where
         }
     }
 
-    async fn perform_websocket_handshake(&mut self) {
+    async fn perform_websocket_handshake(&mut self) -> Result<(), WsError> {
         self.socket_connection =
             match std::mem::replace(&mut self.socket_connection, SocketStream::Invalid) {
                 SocketStream::RawTCP(conn) => {
                     // TODO: perhaps in the future, rather than panic here (and uncleanly shut tcp stream)
                     // return a result with an error?
-                    let ws_stream = tokio_tungstenite::accept_async(conn)
-                        .await
-                        .expect("Failed to perform websocket handshake");
+                    let ws_stream = match tokio_tungstenite::accept_async(conn).await {
+                        Ok(ws_stream) => ws_stream,
+                        // note that socket will remain in `Invalid` state here, but that's
+                        // absolutely fine because due to returned error the handler
+                        // should terminate immediately
+                        Err(err) => return Err(err),
+                    };
                     SocketStream::UpgradedWebSocket(ws_stream)
                 }
                 other => other,
-            }
+            };
+        Ok(())
     }
 
     async fn next_websocket_request(&mut self) -> Option<Result<Message, WsError>> {
@@ -366,7 +371,13 @@ where
     }
 
     pub(crate) async fn start_handling(&mut self) {
-        self.perform_websocket_handshake().await;
+        if let Err(e) = self.perform_websocket_handshake().await {
+            warn!(
+                "Failed to complete WebSocket handshake - {:?}. Stopping the handler",
+                e
+            );
+            return;
+        }
         trace!("Managed to perform websocket handshake!");
         let mix_receiver = self.wait_for_initial_authentication().await;
         trace!("Performed initial authentication");