Add error handling when split tunnel app can't be launched

4 files changed, 91 insertions, 24 deletions

diff --git a/gui/src/main/linux-split-tunneling.ts b/gui/src/main/linux-split-tunneling.ts
index acaa674746..9c41740776 100644
--- a/gui/src/main/linux-split-tunneling.ts
+++ b/gui/src/main/linux-split-tunneling.ts
@@ -2,6 +2,9 @@ import argvSplit from 'argv-split';
 import child_process from 'child_process';
 import path from 'path';
 import { ILinuxSplitTunnelingApplication } from '../shared/application-types';
+import { messages } from '../shared/gettext';
+import { LaunchApplicationResult } from '../shared/ipc-schema';
+import { Scheduler } from '../shared/scheduler';
 import {
   getDesktopEntries,
   readDesktopEntry,
@@ -25,25 +28,74 @@ const PROBLEMATIC_APPLICATIONS = {
   launchingElsewhere: ['gnome-terminal'],
 };
 
+// Launches an application. The application parameter could be a path the an executable or .desktop
+// file or an object representing an application
 export async function launchApplication(
   app: ILinuxSplitTunnelingApplication | string,
-): Promise<void> {
-  let excludeArguments: string[] | undefined;
+): Promise<LaunchApplicationResult> {
+  let excludeArguments: string[];
+  try {
+    excludeArguments = await getLaunchCommand(app);
+  } catch (e) {
+    return { error: e.message };
+  }
+
+  return new Promise((resolve, _reject) => {
+    const scheduler = new Scheduler();
+    const proc = child_process.spawn('mullvad-exclude', excludeArguments, { detached: true });
+
+    // If the process exits within 200 milliseconds the user is notified that it failed to launch.
+    scheduler.schedule(() => {
+      proc.removeAllListeners();
+      resolve({ success: true });
+    }, 200);
+
+    proc.stderr.on('data', (data) => {
+      if (data.includes('Failed to launch the process') && data.includes('ENOENT')) {
+        scheduler.cancel();
+        proc.removeAllListeners();
+        resolve({
+          error:
+            // TRANSLATORS: This error message is shown if the user tries to launch an app that
+            // TRANSLATORS: doesn't exist.
+            messages.pgettext('split-tunneling-view', 'Please try again or contact support.'),
+        });
+      }
+    });
+    proc.once('exit', (code) => {
+      scheduler.cancel();
+      proc.removeAllListeners();
+
+      if (code === 1) {
+        resolve({
+          error:
+            // TRANSLATORS: This error message is shown if an application failes during startup.
+            messages.pgettext('split-tunneling-view', 'Please try again or contact support.'),
+        });
+      } else {
+        resolve({ success: true });
+      }
+    });
+  });
+}
+
+// Takes the same argument as launchApplication and returns the command to run
+async function getLaunchCommand(app: ILinuxSplitTunnelingApplication | string): Promise<string[]> {
   if (typeof app === 'object') {
-    excludeArguments = formatExec(app.exec);
+    return formatExec(app.exec);
   } else if (path.extname(app) === '.desktop') {
     const entry = await readDesktopEntry(app);
     if (entry.exec !== undefined) {
-      excludeArguments = formatExec(entry.exec);
+      return formatExec(entry.exec);
+    } else {
+      throw new Error(
+        // TRANSLATORS: This error message is shown if the user tries to launch a Linux desktop
+        // TRANSLATORS: entry file that doesn't contain the required 'Exec' value.
+        messages.pgettext('split-tunneling-view', 'Please contact support.'),
+      );
     }
   } else {
-    excludeArguments = [app];
-  }
-
-  if (excludeArguments !== undefined && excludeArguments.length > 0) {
-    child_process.spawn('mullvad-exclude', excludeArguments, { detached: true });
-  } else {
-    throw new Error('Invalid application');
+    return [app];
   }
 }
 
diff --git a/gui/src/renderer/app.tsx b/gui/src/renderer/app.tsx
index 739ac48ffe..4c79cc2192 100644
--- a/gui/src/renderer/app.tsx
+++ b/gui/src/renderer/app.tsx
@@ -20,7 +20,7 @@ import { ILinuxSplitTunnelingApplication } from '../shared/application-types';
 import { messages, relayLocations } from '../shared/gettext';
 import { IGuiSettingsState, SYSTEM_PREFERRED_LOCALE_KEY } from '../shared/gui-settings-state';
 import log, { ConsoleOutput } from '../shared/logging';
-import { IRelayListPair } from '../shared/ipc-schema';
+import { IRelayListPair, LaunchApplicationResult } from '../shared/ipc-schema';
 import consumePromise from '../shared/promise';
 import History from './lib/history';
 import { loadTranslations } from './lib/load-translations';
@@ -421,7 +421,7 @@ export default class AppRenderer {
 
   public launchExcludedApplication(
     application: ILinuxSplitTunnelingApplication | string,
-  ): Promise<void> {
+  ): Promise<LaunchApplicationResult> {
     return IpcRendererEventChannel.splitTunneling.launchApplication(application);
   }
 
diff --git a/gui/src/renderer/components/LinuxSplitTunnelingSettings.tsx b/gui/src/renderer/components/LinuxSplitTunnelingSettings.tsx
index 6a87a73a5a..cb7c497011 100644
--- a/gui/src/renderer/components/LinuxSplitTunnelingSettings.tsx
+++ b/gui/src/renderer/components/LinuxSplitTunnelingSettings.tsx
@@ -107,10 +107,20 @@ export default function LinuxSplitTunnelingSettings() {
   const [applications, setApplications] = useState<ILinuxSplitTunnelingApplication[]>();
   const [applicationListHeight, setApplicationListHeight] = useState<number>();
   const [browsing, setBrowsing] = useState(false);
-  const [showBrowseFailureDialog, setShowBrowseFailureDialog] = useState(false);
+  const [browseError, setBrowseError] = useState<string>();
 
   const applicationListRef = useRef() as React.RefObject<HTMLDivElement>;
 
+  const launchApplication = useCallback(
+    async (application: ILinuxSplitTunnelingApplication | string) => {
+      const result = await launchExcludedApplication(application);
+      if ('error' in result) {
+        setBrowseError(result.error);
+      }
+    },
+    [],
+  );
+
   const launchWithFilePicker = useCallback(async () => {
     setBrowsing(true);
     const file = await showOpenDialog({
@@ -120,15 +130,11 @@ export default function LinuxSplitTunnelingSettings() {
     setBrowsing(false);
 
     if (file.filePaths[0]) {
-      try {
-        await launchExcludedApplication(file.filePaths[0]);
-      } catch (e) {
-        setShowBrowseFailureDialog(true);
-      }
+      await launchApplication(file.filePaths[0]);
     }
   }, []);
 
-  const hideBrowseFailureDialog = useCallback(() => setShowBrowseFailureDialog(false), []);
+  const hideBrowseFailureDialog = useCallback(() => setBrowseError(undefined), []);
 
   useEffect(() => {
     consumePromise(getSplitTunnelingApplications().then(setApplications));
@@ -188,7 +194,7 @@ export default function LinuxSplitTunnelingSettings() {
                           <ApplicationRow
                             key={application.absolutepath}
                             application={application}
-                            launchApplication={launchExcludedApplication}
+                            launchApplication={launchApplication}
                           />
                         ))
                       )}
@@ -203,11 +209,18 @@ export default function LinuxSplitTunnelingSettings() {
             </NavigationContainer>
           </StyledContainer>
         </Layout>
-        {showBrowseFailureDialog && (
+        {browseError && (
           <ModalAlert
             type={ModalAlertType.warning}
             iconColor={colors.red}
-            message={messages.pgettext('split-tunneling-view', 'Failed to launch application')}
+            message={sprintf(
+              // TRANSLATORS: Error message showed in a dialog when an application failes to launch.
+              messages.pgettext(
+                'split-tunneling-view',
+                'Unable to launch selection. %(detailedErrorMessage)s',
+              ),
+              { detailedErrorMessage: browseError },
+            )}
             buttons={[
               <AppButton.BlueButton key="close" onClick={hideBrowseFailureDialog}>
                 {messages.gettext('Close')}
diff --git a/gui/src/shared/ipc-schema.ts b/gui/src/shared/ipc-schema.ts
index a31745c01f..62a3afc948 100644
--- a/gui/src/shared/ipc-schema.ts
+++ b/gui/src/shared/ipc-schema.ts
@@ -37,6 +37,8 @@ export interface IRelayListPair {
   bridges: IRelayList;
 }
 
+export type LaunchApplicationResult = { success: true } | { error: string };
+
 export interface IAppStateSnapshot {
   locale: string;
   isConnected: boolean;
@@ -181,7 +183,7 @@ export const ipcSchema = {
   },
   splitTunneling: {
     getApplications: invoke<void, ILinuxSplitTunnelingApplication[]>(),
-    launchApplication: invoke<ILinuxSplitTunnelingApplication | string, void>(),
+    launchApplication: invoke<ILinuxSplitTunnelingApplication | string, LaunchApplicationResult>(),
   },
   problemReport: {
     collectLogs: invoke<string[], string>(),