Attempt to fix TP-Link race condition

.github/workflows/main.yml

@@ -225,7 +225,10 @@ jobs:
           if-no-files-found: error
 
   build_rayhunter:
-    if: needs.files_changed.outputs.daemon_changed != '0'
+    # build_rust_installer needs this step. so when installer_changed, we need
+    # to build this step too. if we skip this step because only the installer
+    # changed, the build_rust_installer step will be skipped too.
+    if: needs.files_changed.outputs.daemon_changed != '0' || needs.files_changed.outputs.installer_changed != '0'
     needs:
       - check_and_test
       - files_changed

installer/src/tplink.rs

@@ -272,9 +272,19 @@ async fn handler(state: State<AppState>, mut req: Request) -> Result<Response, S
         let mut data = BytesMut::from(data);
         // inject some javascript into the admin UI to get us a telnet shell.
         data.extend(br#";window.rayhunterPoll = window.setInterval(() => {
-            Globals.models.PTModel.add({applicationName: "rayhunter-root", enableState: 1, entryId: 1, openPort: "2300-2400", openProtocol: "TCP", triggerPort: "$(busybox telnetd -l /bin/sh)", triggerProtocol: "TCP"});
+            // Intentionally register rayhunter-daemon before rayhunter-root so that we are less
+            // likely to run into race conditions where rayhunter-root is launched, and the
+            // installer kills the server. In practice both HTTP requests may execute concurrently
+            // anyway.
             Globals.models.PTModel.add({applicationName: "rayhunter-daemon", enableState: 1, entryId: 2, openPort: "2400-2500", openProtocol: "TCP", triggerPort: "$(/etc/init.d/rayhunter_daemon start)", triggerProtocol: "TCP"});
-            alert("Success! You can go back to the rayhunter installer.");
+            Globals.models.PTModel.add({applicationName: "rayhunter-root", enableState: 1, entryId: 1, openPort: "2300-2400", openProtocol: "TCP", triggerPort: "$(busybox telnetd -l /bin/sh)", triggerProtocol: "TCP"});
+
+            // Do not use alert(), instead replace page with success message. Using alert() will
+            // block the event loop in such a way that any background promises are blocked from
+            // progress too. For example: The HTTP requests to register our port triggers!
+            document.body.innerHTML = "<h1>Success! You can go back to the rayhunter installer.</h1>";
+
+            // We can stop polling now, presumably both requests are already inflight.
             window.clearInterval(window.rayhunterPoll);
         }, 1000);"#);
         response = Response::from_parts(parts, Body::from(Bytes::from(data)));
@@ -285,6 +295,16 @@ async fn handler(state: State<AppState>, mut req: Request) -> Result<Response, S
 }
 
 async fn tplink_launch_telnet_v5(admin_ip: &str) -> Result<(), Error> {
+    let addr = SocketAddr::from_str(&format!("{admin_ip}:23")).unwrap();
+
+    if telnet_send_command(addr, "true", "exit code 0", true)
+        .await
+        .is_ok()
+    {
+        println!("telnet already appears to be running");
+        return Ok(());
+    }
+
     let client: HttpProxyClient =
         hyper_util::client::legacy::Client::<(), ()>::builder(TokioExecutor::new())
             .build(HttpConnector::new());
@@ -306,15 +326,16 @@ async fn tplink_launch_telnet_v5(admin_ip: &str) -> Result<(), Error> {
 
     let handle = tokio::spawn(async move { axum::serve(listener, app).await });
 
-    let addr = SocketAddr::from_str(&format!("{admin_ip}:23")).unwrap();
-
     while telnet_send_command(addr, "true", "exit code 0", true)
         .await
         .is_err()
     {
         sleep(Duration::from_millis(1000)).await;
     }
 
+    // give the JavaScript code some additional time to run and persist the port triggers.
+    sleep(Duration::from_millis(1000)).await;
+
     handle.abort();
 
     Ok(())