Backend: do not use singletons

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/Application.java

@@ -5,7 +5,6 @@
 
 package com.wireguard.android;
 
-import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
@@ -20,7 +19,6 @@ import androidx.preference.PreferenceManager;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatDelegate;
 
-import com.wireguard.android.activity.MainActivity;
 import com.wireguard.android.backend.Backend;
 import com.wireguard.android.backend.GoBackend;
 import com.wireguard.android.backend.WgQuickBackend;
@@ -88,7 +86,7 @@ public class Application extends android.app.Application {
                     try {
                         if (!didStartRootShell)
                             app.rootShell.start();
-                        backend = new WgQuickBackend(app.getApplicationContext());
+                        backend = new WgQuickBackend(app.getApplicationContext(), app.rootShell, app.toolsInstaller);
                     } catch (final Exception ignored) {
                     }
                 }
@@ -119,6 +117,7 @@ public class Application extends android.app.Application {
     public static ToolsInstaller getToolsInstaller() {
         return get().toolsInstaller;
     }
+
     public static ModuleLoader getModuleLoader() {
         return get().moduleLoader;
     }
@@ -152,8 +151,8 @@ public class Application extends android.app.Application {
 
         asyncWorker = new AsyncWorker(AsyncTask.SERIAL_EXECUTOR, new Handler(Looper.getMainLooper()));
         rootShell = new RootShell(getApplicationContext());
-        toolsInstaller = new ToolsInstaller(getApplicationContext());
-        moduleLoader = new ModuleLoader(getApplicationContext());
+        toolsInstaller = new ToolsInstaller(getApplicationContext(), rootShell);
+        moduleLoader = new ModuleLoader(getApplicationContext(), rootShell, USER_AGENT);
 
         sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {

app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java

@@ -10,9 +10,10 @@ import androidx.annotation.Nullable;
 import android.content.Context;
 import android.util.Log;
 
-import com.wireguard.android.Application;
 import com.wireguard.android.backend.BackendException.Reason;
 import com.wireguard.android.backend.Tunnel.State;
+import com.wireguard.android.util.RootShell;
+import com.wireguard.android.util.ToolsInstaller;
 import com.wireguard.config.Config;
 import com.wireguard.crypto.Key;
 
@@ -40,12 +41,16 @@ import java9.util.stream.Stream;
 public final class WgQuickBackend implements Backend {
     private static final String TAG = "WireGuard/" + WgQuickBackend.class.getSimpleName();
 
+    private final RootShell rootShell;
+    private final ToolsInstaller toolsInstaller;
     private final File localTemporaryDir;
     private final Map<Tunnel, Config> runningConfigs = new HashMap<>();
     private final Set<TunnelStateChangeNotificationReceiver> notifiers = new HashSet<>();
 
-    public WgQuickBackend(final Context context) {
+    public WgQuickBackend(final Context context, final RootShell rootShell, final ToolsInstaller toolsInstaller) {
         localTemporaryDir = new File(context.getCacheDir(), "tmp");
+        this.rootShell = rootShell;
+        this.toolsInstaller = toolsInstaller;
     }
 
     @Override
@@ -53,8 +58,8 @@ public final class WgQuickBackend implements Backend {
         final List<String> output = new ArrayList<>();
         // Don't throw an exception here or nothing will show up in the UI.
         try {
-            Application.getToolsInstaller().ensureToolsAvailable();
-            if (Application.getRootShell().run(output, "wg show interfaces") != 0 || output.isEmpty())
+            toolsInstaller.ensureToolsAvailable();
+            if (rootShell.run(output, "wg show interfaces") != 0 || output.isEmpty())
                 return Collections.emptySet();
         } catch (final Exception e) {
             Log.w(TAG, "Unable to enumerate running tunnels", e);
@@ -74,7 +79,7 @@ public final class WgQuickBackend implements Backend {
         final Statistics stats = new Statistics();
         final Collection<String> output = new ArrayList<>();
         try {
-            if (Application.getRootShell().run(output, String.format("wg show '%s' transfer", tunnel.getName())) != 0)
+            if (rootShell.run(output, String.format("wg show '%s' transfer", tunnel.getName())) != 0)
                 return stats;
         } catch (final Exception ignored) {
             return stats;
@@ -94,8 +99,7 @@ public final class WgQuickBackend implements Backend {
     @Override
     public String getVersion() throws Exception {
         final List<String> output = new ArrayList<>();
-        if (Application.getRootShell()
-                .run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
+        if (rootShell.run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
             throw new BackendException(Reason.UNKNOWN_KERNEL_MODULE_NAME);
         return output.get(0);
     }
@@ -111,7 +115,7 @@ public final class WgQuickBackend implements Backend {
                 (state == State.DOWN && originalState == State.DOWN))
             return originalState;
         if (state == State.UP) {
-            Application.getToolsInstaller().ensureToolsAvailable();
+            toolsInstaller.ensureToolsAvailable();
             if (originalState == State.UP)
                 setStateInternal(tunnel, originalConfig == null ? config : originalConfig, State.DOWN);
             try {
@@ -140,7 +144,7 @@ public final class WgQuickBackend implements Backend {
                 state.toString().toLowerCase(Locale.ENGLISH), tempFile.getAbsolutePath());
         if (state == State.UP)
             command = "cat /sys/module/wireguard/version && " + command;
-        final int result = Application.getRootShell().run(null, command);
+        final int result = rootShell.run(null, command);
         // noinspection ResultOfMethodCallIgnored
         tempFile.delete();
         if (result != 0)

app/src/main/java/com/wireguard/android/util/ModuleLoader.java

@@ -9,7 +9,6 @@ import android.content.Context;
 import android.system.OsConstants;
 import android.util.Base64;
 
-import com.wireguard.android.Application;
 import com.wireguard.android.util.RootShell.RootShellException;
 
 import net.i2p.crypto.eddsa.EdDSAEngine;
@@ -43,12 +42,16 @@ public class ModuleLoader {
     private static final String MODULE_URL = "https://download.wireguard.com/android-module/%s";
     private static final String MODULE_NAME = "wireguard-%s.ko";
 
+    private final RootShell rootShell;
+    private final String userAgent;
     private final File moduleDir;
     private final File tmpDir;
 
-    public ModuleLoader(final Context context) {
+    public ModuleLoader(final Context context, final RootShell rootShell, final String userAgent) {
         moduleDir = new File(context.getCacheDir(), "kmod");
         tmpDir = new File(context.getCacheDir(), "tmp");
+        this.rootShell = rootShell;
+        this.userAgent = userAgent;
     }
 
     public boolean moduleMightExist() {
@@ -56,7 +59,7 @@ public class ModuleLoader {
     }
 
     public void loadModule() throws IOException, RootShellException {
-        Application.getRootShell().run(null, String.format("insmod \"%s/wireguard-$(sha256sum /proc/version|cut -d ' ' -f 1).ko\"", moduleDir.getAbsolutePath()));
+        rootShell.run(null, String.format("insmod \"%s/wireguard-$(sha256sum /proc/version|cut -d ' ' -f 1).ko\"", moduleDir.getAbsolutePath()));
     }
 
     public static boolean isModuleLoaded() {
@@ -124,12 +127,12 @@ public class ModuleLoader {
 
     public Integer download() throws IOException, RootShellException, NoSuchAlgorithmException {
         final List<String> output = new ArrayList<>();
-        Application.getRootShell().run(output, "sha256sum /proc/version|cut -d ' ' -f 1");
+        rootShell.run(output, "sha256sum /proc/version|cut -d ' ' -f 1");
         if (output.size() != 1 || output.get(0).length() != 64)
             throw new InvalidParameterException("Invalid sha256 of /proc/version");
         final String moduleName = String.format(MODULE_NAME, output.get(0));
         HttpURLConnection connection = (HttpURLConnection)new URL(MODULE_LIST_URL).openConnection();
-        connection.setRequestProperty("User-Agent", Application.USER_AGENT);
+        connection.setRequestProperty("User-Agent", userAgent);
         connection.connect();
         if (connection.getResponseCode() != HttpURLConnection.HTTP_OK)
             throw new IOException("Hash list could not be found");
@@ -146,7 +149,7 @@ public class ModuleLoader {
         if (!modules.containsKey(moduleName))
             return OsConstants.ENOENT;
         connection = (HttpURLConnection)new URL(String.format(MODULE_URL, moduleName)).openConnection();
-        connection.setRequestProperty("User-Agent", Application.USER_AGENT);
+        connection.setRequestProperty("User-Agent", userAgent);
         connection.connect();
         if (connection.getResponseCode() != HttpURLConnection.HTTP_OK)
             throw new IOException("Module file could not be found, despite being on hash list");

app/src/main/java/com/wireguard/android/util/ToolsInstaller.java

@@ -10,7 +10,6 @@ import androidx.annotation.Nullable;
 import android.system.OsConstants;
 import android.util.Log;
 
-import com.wireguard.android.Application;
 import com.wireguard.android.BuildConfig;
 import com.wireguard.android.util.RootShell.RootShellException;
 
@@ -39,14 +38,16 @@ public final class ToolsInstaller {
     private static final String TAG = "WireGuard/" + ToolsInstaller.class.getSimpleName();
 
     private final Context context;
+    private final RootShell rootShell;
     private final File localBinaryDir;
     private final Object lock = new Object();
     @Nullable private Boolean areToolsAvailable;
     @Nullable private Boolean installAsMagiskModule;
 
-    public ToolsInstaller(final Context context) {
+    public ToolsInstaller(final Context context, final RootShell rootShell) {
         localBinaryDir = new File(context.getCodeCacheDir(), "bin");
         this.context = context;
+        this.rootShell = rootShell;
     }
 
     @Nullable
@@ -73,7 +74,7 @@ public final class ToolsInstaller {
         }
         script.append("exit ").append(OsConstants.EALREADY).append(';');
         try {
-            final int ret = Application.getRootShell().run(null, script.toString());
+            final int ret = rootShell.run(null, script.toString());
             if (ret == OsConstants.EALREADY)
                 return willInstallAsMagiskModule() ? YES | MAGISK : YES | SYSTEM;
             else
@@ -124,7 +125,7 @@ public final class ToolsInstaller {
         script.append("trap - INT TERM EXIT;");
 
         try {
-            return Application.getRootShell().run(null, script.toString()) == 0 ? YES | MAGISK : ERROR;
+            return rootShell.run(null, script.toString()) == 0 ? YES | MAGISK : ERROR;
         } catch (final IOException ignored) {
             return ERROR;
         } catch (final RootShellException e) {
@@ -146,7 +147,7 @@ public final class ToolsInstaller {
                     new File(localBinaryDir, name), destination, destination, destination));
         }
         try {
-            return Application.getRootShell().run(null, script.toString()) == 0 ? YES | SYSTEM : ERROR;
+            return rootShell.run(null, script.toString()) == 0 ? YES | SYSTEM : ERROR;
         } catch (final IOException ignored) {
             return ERROR;
         } catch (final RootShellException e) {
@@ -183,7 +184,7 @@ public final class ToolsInstaller {
         synchronized (lock) {
             if (installAsMagiskModule == null) {
                 try {
-                    installAsMagiskModule = Application.getRootShell().run(null, "[ -d /sbin/.magisk/mirror -a -d /sbin/.magisk/img -a ! -f /cache/.disable_magisk ]") == OsConstants.EXIT_SUCCESS;
+                    installAsMagiskModule = rootShell.run(null, "[ -d /sbin/.magisk/mirror -a -d /sbin/.magisk/img -a ! -f /cache/.disable_magisk ]") == OsConstants.EXIT_SUCCESS;
                 } catch (final Exception ignored) {
                     installAsMagiskModule = false;
                 }