ToolsInstaller: allow installing as Magisk module

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

app/src/main/java/com/wireguard/android/preference/ToolsInstallerPreference.java

@@ -26,7 +26,7 @@ import com.wireguard.android.util.ToolsInstaller;
 public class ToolsInstallerPreference extends Preference {
     private final AsyncWorker asyncWorker;
     private final ToolsInstaller toolsInstaller;
-    private State state = State.INITIAL;
+    private State state;
 
     @SuppressWarnings({"SameParameterValue", "WeakerAccess"})
     public ToolsInstallerPreference(final Context context, final AttributeSet attrs) {
@@ -34,6 +34,7 @@ public class ToolsInstallerPreference extends Preference {
         final ApplicationComponent applicationComponent = Application.getComponent();
         asyncWorker = applicationComponent.getAsyncWorker();
         toolsInstaller = applicationComponent.getToolsInstaller();
+        state = initialState();
     }
 
     @Override
@@ -54,12 +55,12 @@ public class ToolsInstallerPreference extends Preference {
 
     private void onCheckResult(final Integer result, final Throwable throwable) {
         setState(throwable == null && result == OsConstants.EALREADY ?
-                State.ALREADY : State.INITIAL);
+                State.ALREADY : initialState());
     }
 
     @Override
     protected void onClick() {
-        setState(State.WORKING);
+        setState(workingState());
         asyncWorker.supplyAsync(toolsInstaller::install).whenComplete(this::onInstallResult);
     }
 
@@ -68,7 +69,7 @@ public class ToolsInstallerPreference extends Preference {
         if (throwable != null)
             nextState = State.FAILURE;
         else if (result == OsConstants.EXIT_SUCCESS)
-            nextState = State.SUCCESS;
+            nextState = successState();
         else if (result == OsConstants.EALREADY)
             nextState = State.ALREADY;
         else
@@ -85,12 +86,25 @@ public class ToolsInstallerPreference extends Preference {
         notifyChanged();
     }
 
+    private State initialState() {
+        return toolsInstaller.willInstallAsMagiskModule() ? State.INITIAL_MAGISK : State.INITIAL_SYSTEM;
+    }
+    private State workingState() {
+        return toolsInstaller.willInstallAsMagiskModule() ? State.WORKING_MAGISK : State.WORKING_SYSTEM;
+    }
+    private State successState() {
+        return toolsInstaller.willInstallAsMagiskModule() ? State.SUCCESS_MAGISK : State.SUCCESS_SYSTEM;
+    }
+
     private enum State {
         ALREADY(R.string.tools_installer_already, false),
         FAILURE(R.string.tools_installer_failure, true),
-        INITIAL(R.string.tools_installer_initial, true),
+        INITIAL_SYSTEM(R.string.tools_installer_initial_system, true),
-        SUCCESS(R.string.tools_installer_success, false),
+        SUCCESS_SYSTEM(R.string.tools_installer_success_system, false),
-        WORKING(R.string.tools_installer_working, false);
+        WORKING_SYSTEM(R.string.tools_installer_working_system, false),
+        INITIAL_MAGISK(R.string.tools_installer_initial_magisk, true),
+        SUCCESS_MAGISK(R.string.tools_installer_success_magisk, false),
+        WORKING_MAGISK(R.string.tools_installer_working_magisk, false);
 
         private final int messageResourceId;
         private final boolean shouldEnableView;

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

@@ -13,6 +13,7 @@ import android.util.Log;
 import com.wireguard.android.Application;
 import com.wireguard.android.Application.ApplicationContext;
 import com.wireguard.android.Application.ApplicationScope;
+import com.wireguard.android.BuildConfig;
 import com.wireguard.android.util.RootShell.NoRootException;
 
 import java.io.File;
@@ -48,6 +49,7 @@ public final class ToolsInstaller {
     private final File nativeLibraryDir;
     private final RootShell rootShell;
     private Boolean areToolsAvailable;
+    private Boolean installAsMagiskModule;
 
     @Inject
     public ToolsInstaller(@ApplicationContext final Context context, final RootShell rootShell) {
@@ -114,7 +116,20 @@ public final class ToolsInstaller {
         }
     }
 
-    public int install() throws NoRootException {
+    public boolean willInstallAsMagiskModule() {
+        synchronized (lock) {
+            if (installAsMagiskModule == null) {
+                try {
+                    installAsMagiskModule = rootShell.run(null, "[ -d /sbin/.core/mirror -a -d /sbin/.core/img -a ! -f /cache/.disable_magisk ]") == OsConstants.EXIT_SUCCESS;
+                } catch (final Exception ignored) {
+                    installAsMagiskModule = false;
+                }
+            }
+            return installAsMagiskModule;
+        }
+    }
+
+    private int installSystem() throws NoRootException {
         if (INSTALL_DIR == null)
             return OsConstants.ENOENT;
         final StringBuilder script = new StringBuilder("set -ex; ");
@@ -131,6 +146,31 @@ public final class ToolsInstaller {
         }
     }
 
+    private int installMagisk() throws NoRootException {
+        final StringBuilder script = new StringBuilder("set -ex; ");
+
+        script.append("trap 'rm -rf /sbin/.core/img/wireguard' INT TERM EXIT; ");
+        script.append(String.format("rm -rf /sbin/.core/img/wireguard/; mkdir -p /sbin/.core/img/wireguard%s; ", INSTALL_DIR));
+        script.append(String.format("printf 'name=WireGuard Command Line Tools\nversion=%s\nversionCode=%s\nauthor=zx2c4\ndescription=Command line tools for WireGuard\nminMagisk=1500\n' > /sbin/.core/img/wireguard/module.prop; ", BuildConfig.VERSION_NAME, BuildConfig.VERSION_CODE));
+        script.append("touch /sbin/.core/img/wireguard/auto_mount; ");
+        for (final String[] names : EXECUTABLES) {
+            final File destination = new File("/sbin/.core/img/wireguard" + INSTALL_DIR, names[1]);
+            script.append(String.format("cp '%s' '%s'; chmod 755 '%s'; restorecon '%s' || true; ",
+                    new File(nativeLibraryDir, names[0]), destination, destination, destination));
+        }
+        script.append("trap - INT TERM EXIT;");
+
+        try {
+            return rootShell.run(null, script.toString());
+        } catch (final IOException ignored) {
+            return OsConstants.EXIT_FAILURE;
+        }
+    }
+
+    public int install() throws NoRootException {
+        return willInstallAsMagiskModule() ? installMagisk() : installSystem();
+    }
+
     public int symlink() throws NoRootException {
         final StringBuilder script = new StringBuilder("set -x; ");
         for (final String[] names : EXECUTABLES) {

app/src/main/res/values/strings.xml

@@ -69,10 +69,13 @@
     <string name="toggle_error">Error toggling WireGuard tunnel: %s</string>
     <string name="tools_installer_already">wg and wg-quick are already installed</string>
     <string name="tools_installer_failure">Unable to install command-line tools (no root?)</string>
-    <string name="tools_installer_initial">Install optional tools for scripting into the system partition</string>
+    <string name="tools_installer_initial_system">Install optional tools for scripting into the system partition</string>
-    <string name="tools_installer_success">wg and wg-quick installed into the system partition</string>
+    <string name="tools_installer_initial_magisk">Install optional tools for scripting as Magisk module</string>
+    <string name="tools_installer_success_system">wg and wg-quick installed into the system partition</string>
+    <string name="tools_installer_success_magisk">wg and wg-quick installed as a Magisk module (reboot required)</string>
     <string name="tools_installer_title">Install command line tools</string>
-    <string name="tools_installer_working">Installing wg and wg-quick into the system partition</string>
+    <string name="tools_installer_working_system">Installing wg and wg-quick into the system partition</string>
+    <string name="tools_installer_working_magisk">Installing wg and wg-quick as a Magisk module</string>
     <string name="tunnel_create_error">Unable to create tunnel: %s</string>
     <string name="tunnel_create_success">Successfully created tunnel “%s”</string>
     <string name="tunnel_rename_error">Unable to rename tunnel: %s</string>