Add function for retrieving installed applications on Linux

8 files changed, 298 insertions, 0 deletions

diff --git a/gui/package-lock.json b/gui/package-lock.json
index 5483118558..0e52689192 100644
--- a/gui/package-lock.json
+++ b/gui/package-lock.json
@@ -1143,6 +1143,11 @@
         }
       }
     },
+    "argv-split": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/argv-split/-/argv-split-2.0.1.tgz",
+      "integrity": "sha1-viZBF3kNvVzNY+w/RJoYBIFKxMU="
+    },
     "arr-diff": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/arr-diff/-/arr-diff-4.0.0.tgz",
@@ -6782,6 +6787,11 @@
       "integrity": "sha512-XCpr5bElgDI65vVgstP8TWjv6/QKWm9GU5UG0Pr5sLQ3QLo8NVKsioe+Jed5/3vFOe3IQuqE7DKwTvKQkjTHvg==",
       "dev": true
     },
+    "linux-app-list": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/linux-app-list/-/linux-app-list-1.0.1.tgz",
+      "integrity": "sha1-w76XF+Ngg0KTmR06Ju2DtPXqAn0="
+    },
     "load-json-file": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/load-json-file/-/load-json-file-1.1.0.tgz",
diff --git a/gui/package.json b/gui/package.json
index 2431d7d181..5e01303197 100644
--- a/gui/package.json
+++ b/gui/package.json
@@ -12,12 +12,14 @@
   "repository": "https://github.com/mullvad/mullvadvpn-app",
   "license": "GPL-3.0",
   "dependencies": {
+    "argv-split": "^2.0.1",
     "connected-react-router": "^6.8.0",
     "d3-geo-projection": "^2.7.0",
     "electron-log": "^4.1.1",
     "gettext-parser": "^4.0.3",
     "history": "^4.6.1",
     "jsonrpc-lite": "^2.0.7",
+    "linux-app-list": "^1.0.1",
     "mkdirp": "^1.0.3",
     "moment": "^2.24.0",
     "node-gettext": "^3.0.0",
diff --git a/gui/src/main/index.ts b/gui/src/main/index.ts
index f375de7eca..53ee113410 100644
--- a/gui/src/main/index.ts
+++ b/gui/src/main/index.ts
@@ -59,6 +59,9 @@ import ReconnectionBackoff from './reconnection-backoff';
 import TrayIconController, { TrayIconType } from './tray-icon-controller';
 import WindowController from './window-controller';
 
+// Only import when running app on Linux.
+const linuxSplitTunneling = process.platform === 'linux' && require('./linux-split-tunneling');
+
 const DAEMON_RPC_PATH =
   process.platform === 'win32' ? '//./pipe/Mullvad VPN' : '/var/run/mullvad-vpn';
 
@@ -1005,6 +1008,22 @@ class ApplicationMain {
     });
     IpcMainEventChannel.wireguardKeys.handleVerifyKey(() => this.daemonRpc.verifyWireguardKey());
 
+    IpcMainEventChannel.splitTunneling.handleGetApplications(() => {
+      if (linuxSplitTunneling) {
+        return linuxSplitTunneling.getApplications(this.locale);
+      } else {
+        throw Error('linuxSplitTunneling called without being imported');
+      }
+    });
+    IpcMainEventChannel.splitTunneling.handleLaunchApplication((application) => {
+      if (linuxSplitTunneling) {
+        linuxSplitTunneling.launchApplication(application);
+        return Promise.resolve();
+      } else {
+        throw Error('linuxSplitTunneling called without being imported');
+      }
+    });
+
     ipcMain.on('show-window', () => {
       const windowController = this.windowController;
       if (windowController) {
diff --git a/gui/src/main/linux-split-tunneling.ts b/gui/src/main/linux-split-tunneling.ts
new file mode 100644
index 0000000000..f2ea40da13
--- /dev/null
+++ b/gui/src/main/linux-split-tunneling.ts
@@ -0,0 +1,207 @@
+import argvSplit from 'argv-split';
+import child_process from 'child_process';
+import log from 'electron-log';
+import fs from 'fs';
+import linuxAppList, { AppData } from 'linux-app-list';
+import path from 'path';
+import ISplitTunnelingApplication from '../shared/linux-split-tunneling-application';
+import { pascalCaseToCamelCase } from './transform-object-keys';
+
+type DirectoryDescription = string | RegExp;
+
+interface IApplication extends ISplitTunnelingApplication {
+  type: string;
+  terminal?: string;
+  noDisplay?: string;
+  hidden?: string;
+  onlyShowIn?: string | string[];
+  notShowIn?: string | string[];
+  tryExec?: string;
+}
+
+export function launchApplication(app: ISplitTunnelingApplication | string) {
+  const excludeArguments = typeof app === 'string' ? [app] : formatExec(app.exec);
+  child_process.spawn('mullvad-exclude', excludeArguments, { detached: true });
+}
+
+// Removes placeholder arguments and separates command into list of strings
+function formatExec(exec: string) {
+  return argvSplit(exec).filter((argument: string) => !/%[cdDfFikmnNuUv]/.test(argument));
+}
+
+// TODO: Switch to asyncronous reading of .desktop files
+export function getApplications(locale: string): Promise<ISplitTunnelingApplication[]> {
+  const appList = linuxAppList();
+  const applications = appList
+    .list()
+    .map((filename) => {
+      const applications = localizeNameAndIcon(appList.data(filename), locale);
+      return pascalCaseToCamelCase<IApplication>(applications);
+    })
+    .filter(shouldShowApplication)
+    .sort((a, b) => a.name.localeCompare(b.name))
+    .map(async (app) => ({ ...app, icon: await replaceWithIconPath(app.icon) }));
+
+  return Promise.all(applications);
+}
+
+// Implemented according to freedesktop specification
+// https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html
+// TODO: Respect "TryExec"
+function shouldShowApplication(application: IApplication): boolean {
+  const originalXdgCurrentDesktop = process.env.ORIGINAL_XDG_CURRENT_DESKTOP?.split(':') ?? [];
+  const xdgCurrentDesktop = process.env.XDG_CURRENT_DESKTOP?.split(':') ?? [];
+  const desktopEnvironments = originalXdgCurrentDesktop.concat(xdgCurrentDesktop);
+
+  const notShowIn =
+    typeof application.notShowIn === 'string' ? [application.notShowIn] : application.notShowIn;
+  const onlyShowIn =
+    typeof application.onlyShowIn === 'string' ? [application.onlyShowIn] : application.onlyShowIn;
+
+  const notShowInMatch = notShowIn?.some((desktopEnvironment) =>
+    desktopEnvironments?.includes(desktopEnvironment),
+  );
+  const onlyShowInMatch =
+    onlyShowIn?.some((desktopEnvironment) => desktopEnvironments?.includes(desktopEnvironment)) ??
+    false;
+
+  return (
+    application.type === 'Application' &&
+    application.name !== 'Mullvad VPN' &&
+    application.exec !== undefined &&
+    application.noDisplay !== 'true' &&
+    application.terminal !== 'true' &&
+    application.hidden !== 'true' &&
+    !notShowInMatch &&
+    (!application.onlyShowIn || onlyShowInMatch)
+  );
+}
+
+function localizeNameAndIcon(application: AppData, locale: string) {
+  if (application.lang) {
+    // linux-app-list prefixes and suffixes the locale keys with a space for some reason.
+    const lang = Object.fromEntries(
+      Object.entries(application.lang).map(([locale, value]) => [locale.trim(), value]),
+    )[locale];
+
+    application.Name = lang?.Name ?? application.Name;
+    application.Icon = lang?.Icon ?? application.Icon;
+  }
+
+  return application;
+}
+
+function getGtkThemeDirectories(): Promise<DirectoryDescription[]> {
+  // "hicolor" is fallback theme and should always be checked. If no icon is found search is
+  // continued in other themes.
+  const themes = ['hicolor', /.*/];
+  return new Promise((resolve, _reject) => {
+    // Electron modifies XDG_CURRENT_DESKTOP and saves the old value in ORIGINAL_XDG_CURRENT_DESKTOP
+    const xdgCurrentDesktop =
+      process.env.ORIGINAL_XDG_CURRENT_DESKTOP ?? process.env.XDG_CURRENT_DESKTOP ?? '';
+    child_process.exec(
+      'gsettings get org.gnome.desktop.interface icon-theme',
+      { env: { XDG_CURRENT_DESKTOP: xdgCurrentDesktop } },
+      (error, stdout) => {
+        if (error) {
+          log.error('Error while retrieving theme', error);
+          resolve(themes);
+        } else {
+          const theme = stdout.trim().replace(new RegExp("^'|'$", 'g'), '');
+          resolve(theme === '' ? themes : [theme, ...themes]);
+        }
+      },
+    );
+  });
+}
+
+// Implemented according to freedesktop specification.
+// https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html
+function getIconDirectories() {
+  const directories: string[] = [];
+
+  if (process.env.HOME) {
+    directories.push(path.join(process.env.HOME, '.icons'));
+    directories.push(path.join(process.env.HOME, '.local', 'share', 'icons')); // For KDE Plasma
+  }
+
+  if (process.env.XDG_DATA_DIRS) {
+    const dataDirs = process.env.XDG_DATA_DIRS.split(':').map((dir) => path.join(dir, 'icons'));
+    directories.push(...dataDirs);
+  }
+
+  directories.push('/usr/share/pixmaps');
+
+  return directories;
+}
+
+async function replaceWithIconPath(name?: string) {
+  if (!name || path.isAbsolute(name)) {
+    return name;
+  }
+
+  // Chrome doesn't support .xpm files
+  const extensions = ['svg', 'png'];
+  return findIcon(name, extensions, [
+    getIconDirectories(),
+    await getGtkThemeDirectories(),
+    // Begin with preferred sized but if nothing matches other sizes should be considered as well.
+    ['scalable', '256x256', '512x512', '256x256@2x', '128x128@2x', '128x128', /^\d+x\d+(@2x)?$/],
+    // Search in all categories of icons.
+    [/.*/],
+  ]);
+}
+
+// Searches through a directory tree according to the directory lists supplied. E.g. The arguments
+// ('mullvad', ['svg', 'png'], [['a', 'b'], ['c', 'd']]) will search for mullvad.svg and mullvad.png
+// in the directories a, a/c, a/d, b, b/c and b/d.
+async function findIcon(
+  name: string,
+  extensions: string[],
+  [directories, ...restDirectories]: [string[], ...DirectoryDescription[][]],
+): Promise<string | undefined> {
+  for (const directory of directories) {
+    let contents: string[] | undefined;
+    try {
+      contents = await fs.promises.readdir(directory);
+    } catch (error) {
+      // Non-existent directories and files (not a directory) are expected.
+      if (error.code !== 'ENOENT' && error.code !== 'ENOTDIR') {
+        log.error(`Failed to open directory while searching for ${name} icon`, error);
+      }
+    }
+
+    if (contents) {
+      const iconPath = contents.find((item) =>
+        extensions.some((extension) => item === `${name}.${extension}`),
+      );
+
+      if (iconPath) {
+        return path.join(directory, iconPath);
+      } else if (restDirectories.length > 0) {
+        const nextDirectories = matchDirectories(restDirectories[0], contents);
+        const iconPath = await findIcon(name, extensions, [
+          nextDirectories.map((nextDirectory) => path.join(directory, nextDirectory)),
+          ...restDirectories.slice(1),
+        ]);
+
+        if (iconPath) {
+          return iconPath;
+        }
+      }
+    }
+  }
+
+  return undefined;
+}
+
+function matchDirectories(directories: DirectoryDescription[], contents: string[]) {
+  const matches = directories
+    .map((directory) =>
+      directory instanceof RegExp ? contents.filter((item) => directory.test(item)) : directory,
+    )
+    .flat();
+
+  // Remove duplicates
+  return [...new Set(matches)];
+}
diff --git a/gui/src/shared/ipc-event-channel.ts b/gui/src/shared/ipc-event-channel.ts
index b020808e76..3c4cd55cfb 100644
--- a/gui/src/shared/ipc-event-channel.ts
+++ b/gui/src/shared/ipc-event-channel.ts
@@ -6,6 +6,7 @@ import { IGuiSettingsState } from './gui-settings-state';
 
 import { ICurrentAppVersionInfo } from '../main/index';
 import { IWindowShapeParameters } from '../main/window-controller';
+import ISplitTunnelingApplication from '../shared/linux-split-tunneling-application';
 import {
   AccountToken,
   BridgeSettings,
@@ -151,6 +152,18 @@ interface IWireguardKeyHandlers extends ISender<IWireguardPublicKey | undefined>
   handleVerifyKey(fn: () => Promise<boolean>): void;
 }
 
+interface ISplitTunnelingMethods {
+  getApplications(): Promise<ISplitTunnelingApplication[]>;
+  launchApplication(application: ISplitTunnelingApplication | string): Promise<void>;
+}
+
+interface ISplitTunnelingHandlers {
+  handleGetApplications(fn: () => Promise<ISplitTunnelingApplication[]>): void;
+  handleLaunchApplication(
+    fn: (application: ISplitTunnelingApplication | string) => Promise<void>,
+  ): void;
+}
+
 /// Events names
 
 const LOCALE_CHANGED = 'locale-changed';
@@ -207,6 +220,9 @@ const WIREGUARD_KEYGEN_EVENT = 'wireguard-keygen-event';
 const GENERATE_WIREGUARD_KEY = 'generate-wireguard-key';
 const VERIFY_WIREGUARD_KEY = 'verify-wireguard-key';
 
+const SPLIT_TUNNELING_GET_APPLICATIONS = 'split-tunneling-get-applications';
+const SPLIT_TUNNELING_LAUNCH_APPLICATION = 'split-tunneling-launch-application';
+
 /// Typed IPC event channel
 ///
 /// Static methods are meant to be provide the way to send the events from a renderer process, while
@@ -306,6 +322,11 @@ export class IpcRendererEventChannel {
     generateKey: requestSender(GENERATE_WIREGUARD_KEY),
     verifyKey: requestSender(VERIFY_WIREGUARD_KEY),
   };
+
+  public static splitTunneling: ISplitTunnelingMethods = {
+    getApplications: requestSender(SPLIT_TUNNELING_GET_APPLICATIONS),
+    launchApplication: requestSender(SPLIT_TUNNELING_LAUNCH_APPLICATION),
+  };
 }
 
 export class IpcMainEventChannel {
@@ -403,6 +424,11 @@ export class IpcMainEventChannel {
     handleGenerateKey: requestHandler(GENERATE_WIREGUARD_KEY),
     handleVerifyKey: requestHandler(VERIFY_WIREGUARD_KEY),
   };
+
+  public static splitTunneling: ISplitTunnelingHandlers = {
+    handleGetApplications: requestHandler(SPLIT_TUNNELING_GET_APPLICATIONS),
+    handleLaunchApplication: requestHandler(SPLIT_TUNNELING_LAUNCH_APPLICATION),
+  };
 }
 
 function listen<T>(event: string): (fn: (value: T) => void) => void {
diff --git a/gui/src/shared/linux-split-tunneling-application.ts b/gui/src/shared/linux-split-tunneling-application.ts
new file mode 100644
index 0000000000..f75406b301
--- /dev/null
+++ b/gui/src/shared/linux-split-tunneling-application.ts
@@ -0,0 +1,6 @@
+export default interface ISplitTunnelingApplication {
+  absolutepath: string;
+  name: string;
+  exec: string;
+  icon?: string;
+}
diff --git a/gui/types/argv-split/index.d.ts b/gui/types/argv-split/index.d.ts
new file mode 100644
index 0000000000..625a0c383f
--- /dev/null
+++ b/gui/types/argv-split/index.d.ts
@@ -0,0 +1,3 @@
+declare module 'argv-split' {
+  export default function split(arg: string): string[];
+}
diff --git a/gui/types/linux-app-list/index.d.ts b/gui/types/linux-app-list/index.d.ts
new file mode 100644
index 0000000000..80ad1ebac0
--- /dev/null
+++ b/gui/types/linux-app-list/index.d.ts
@@ -0,0 +1,25 @@
+// Implemented in accordance with this specification:
+// https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html
+declare module 'linux-app-list' {
+  export interface AppData {
+    absolutepath: string;
+    Name: string;
+    Type: string;
+    Icon?: string;
+    Exec?: string;
+    lang?: Record<string, { Name: string; Icon: string }>;
+    Terminal?: string;
+    NoDisplay?: string;
+    Hidden?: string;
+    OnlyShowIn?: string | string[];
+    NotShowIn?: string | string[];
+    TryExec?: string;
+  }
+
+  export interface AppList {
+    list(): string[];
+    data(app: string): AppData;
+  }
+
+  export default function indexItems(): AppList;
+}