RootShell: properly use errormessages

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

4 files changed, 71 insertions, 33 deletions

diff --git a/app/src/main/java/com/wireguard/android/util/ErrorMessages.java b/app/src/main/java/com/wireguard/android/util/ErrorMessages.java
index 59d513f4..481a6ffb 100644
--- a/app/src/main/java/com/wireguard/android/util/ErrorMessages.java
+++ b/app/src/main/java/com/wireguard/android/util/ErrorMessages.java
@@ -13,6 +13,7 @@ import androidx.annotation.Nullable;
 import com.wireguard.android.Application;
 import com.wireguard.android.R;
 import com.wireguard.android.backend.BackendException;
+import com.wireguard.android.util.RootShell.RootShellException;
 import com.wireguard.config.BadConfigException;
 import com.wireguard.config.BadConfigException.Location;
 import com.wireguard.config.InetEndpoint;
@@ -49,6 +50,14 @@ public final class ErrorMessages {
             BackendException.Reason.TUN_CREATION_ERROR, R.string.tun_create_error,
             BackendException.Reason.GO_ACTIVATION_ERROR_CODE, R.string.tunnel_on_error
     ));
+    private static final Map<RootShellException.Reason, Integer> RSE_REASON_MAP = new EnumMap<>(Maps.of(
+            RootShellException.Reason.NO_ROOT_ACCESS, R.string.error_root,
+            RootShellException.Reason.SHELL_MARKER_COUNT_ERROR, R.string.shell_marker_count_error,
+            RootShellException.Reason.SHELL_EXIT_STATUS_READ_ERROR, R.string.shell_exit_status_read_error,
+            RootShellException.Reason.SHELL_START_ERROR, R.string.shell_start_error,
+            RootShellException.Reason.CREATE_BIN_DIR_ERROR, R.string.create_bin_dir_error,
+            RootShellException.Reason.CREATE_TEMP_DIR_ERROR, R.string.create_temp_dir_error
+    ));
     private static final Map<Format, Integer> KFE_FORMAT_MAP = new EnumMap<>(Maps.of(
             Format.BASE64, R.string.key_length_explanation_base64,
             Format.BINARY, R.string.key_length_explanation_binary,
@@ -89,6 +98,9 @@ public final class ErrorMessages {
         } else if (rootCause instanceof BackendException) {
             final BackendException be = (BackendException) rootCause;
             message = resources.getString(BE_REASON_MAP.get(be.getReason()), be.getFormat());
+        } else if (rootCause instanceof RootShellException) {
+            final RootShellException rse = (RootShellException) rootCause;
+            message = resources.getString(RSE_REASON_MAP.get(rse.getReason()), rse.getFormat());
         } else if (rootCause.getMessage() != null) {
             message = rootCause.getMessage();
         } else {
@@ -135,7 +147,8 @@ public final class ErrorMessages {
     private static Throwable rootCause(final Throwable throwable) {
         Throwable cause = throwable;
         while (cause.getCause() != null) {
-            if (cause instanceof BadConfigException || cause instanceof BackendException)
+            if (cause instanceof BadConfigException || cause instanceof BackendException ||
+                    cause instanceof RootShellException)
                 break;
             final Throwable nextCause = cause.getCause();
             if (nextCause instanceof RemoteException)
diff --git a/app/src/main/java/com/wireguard/android/util/ModuleLoader.java b/app/src/main/java/com/wireguard/android/util/ModuleLoader.java
index 7794dd5c..7c943d26 100644
--- a/app/src/main/java/com/wireguard/android/util/ModuleLoader.java
+++ b/app/src/main/java/com/wireguard/android/util/ModuleLoader.java
@@ -10,7 +10,7 @@ import android.system.OsConstants;
 import android.util.Base64;
 
 import com.wireguard.android.Application;
-import com.wireguard.android.util.RootShell.NoRootException;
+import com.wireguard.android.util.RootShell.RootShellException;
 
 import net.i2p.crypto.eddsa.EdDSAEngine;
 import net.i2p.crypto.eddsa.EdDSAPublicKey;
@@ -55,7 +55,7 @@ public class ModuleLoader {
         return moduleDir.exists() && moduleDir.isDirectory();
     }
 
-    public void loadModule() throws IOException, NoRootException {
+    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()));
     }
 
@@ -122,7 +122,7 @@ public class ModuleLoader {
         return hashes;
     }
 
-    public Integer download() throws IOException, NoRootException, NoSuchAlgorithmException {
+    public Integer download() throws IOException, RootShellException, NoSuchAlgorithmException {
         final List<String> output = new ArrayList<>();
         Application.getRootShell().run(output, "sha256sum /proc/version|cut -d ' ' -f 1");
         if (output.size() != 1 || output.get(0).length() != 64)
diff --git a/app/src/main/java/com/wireguard/android/util/RootShell.java b/app/src/main/java/com/wireguard/android/util/RootShell.java
index 1fe5667a..63d2c906 100644
--- a/app/src/main/java/com/wireguard/android/util/RootShell.java
+++ b/app/src/main/java/com/wireguard/android/util/RootShell.java
@@ -10,11 +10,10 @@ import androidx.annotation.Nullable;
 import android.util.Log;
 
 import com.wireguard.android.BuildConfig;
-import com.wireguard.android.R;
+import com.wireguard.android.util.RootShell.RootShellException.Reason;
 
 import java.io.BufferedReader;
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
@@ -30,8 +29,6 @@ public class RootShell {
     private static final String SU = "su";
     private static final String TAG = "WireGuard/" + RootShell.class.getSimpleName();
 
-    private final Context context;
-    private final String deviceNotRootedMessage;
     private final File localBinaryDir;
     private final File localTemporaryDir;
     private final Object lock = new Object();
@@ -42,12 +39,10 @@ public class RootShell {
     @Nullable private BufferedReader stdout;
 
     public RootShell(final Context context) {
-        deviceNotRootedMessage = context.getString(R.string.error_root);
         localBinaryDir = new File(context.getCodeCacheDir(), "bin");
         localTemporaryDir = new File(context.getCacheDir(), "tmp");
         preamble = String.format("export CALLING_PACKAGE=%s PATH=\"%s:$PATH\" TMPDIR='%s'; id -u\n",
                 BuildConfig.APPLICATION_ID, localBinaryDir, localTemporaryDir);
-        this.context = context;
     }
 
     private static boolean isExecutableInPath(final String name) {
@@ -83,7 +78,7 @@ public class RootShell {
      * @return The exit value of the command.
      */
     public int run(@Nullable final Collection<String> output, final String command)
-            throws IOException, NoRootException {
+            throws IOException, RootShellException {
         synchronized (lock) {
             /* Start inside synchronized block to prevent a concurrent call to stop(). */
             start();
@@ -122,24 +117,24 @@ public class RootShell {
                 }
             }
             if (markersSeen != 4)
-                throw new IOException(context.getString(R.string.shell_marker_count_error, markersSeen));
+                throw new RootShellException(Reason.SHELL_MARKER_COUNT_ERROR, markersSeen);
             if (errnoStdout != errnoStderr)
-                throw new IOException(context.getString(R.string.shell_exit_status_read_error));
+                throw new RootShellException(Reason.SHELL_EXIT_STATUS_READ_ERROR);
             Log.v(TAG, "exit: " + errnoStdout);
             return errnoStdout;
         }
     }
 
-    public void start() throws IOException, NoRootException {
+    public void start() throws IOException, RootShellException {
         if (!isExecutableInPath(SU))
-            throw new NoRootException(deviceNotRootedMessage);
+            throw new RootShellException(Reason.NO_ROOT_ACCESS);
         synchronized (lock) {
             if (isRunning())
                 return;
             if (!localBinaryDir.isDirectory() && !localBinaryDir.mkdirs())
-                throw new FileNotFoundException(context.getString(R.string.create_bin_dir_error));
+                throw new RootShellException(Reason.CREATE_BIN_DIR_ERROR);
             if (!localTemporaryDir.isDirectory() && !localTemporaryDir.mkdirs())
-                throw new FileNotFoundException(context.getString(R.string.create_temp_dir_error));
+                throw new RootShellException(Reason.CREATE_TEMP_DIR_ERROR);
             try {
                 final ProcessBuilder builder = new ProcessBuilder().command(SU);
                 builder.environment().put("LC_ALL", "C");
@@ -147,7 +142,9 @@ public class RootShell {
                     process = builder.start();
                 } catch (final IOException e) {
                     // A failure at this stage means the device isn't rooted.
-                    throw new NoRootException(deviceNotRootedMessage, e);
+                    final RootShellException rse = new RootShellException(Reason.NO_ROOT_ACCESS);
+                    rse.initCause(e);
+                    throw rse;
                 }
                 stdin = new OutputStreamWriter(process.getOutputStream(), StandardCharsets.UTF_8);
                 stdout = new BufferedReader(new InputStreamReader(process.getInputStream(),
@@ -160,18 +157,18 @@ public class RootShell {
                 final String uid = stdout.readLine();
                 if (!"0".equals(uid)) {
                     Log.w(TAG, "Root check did not return correct UID: " + uid);
-                    throw new NoRootException(deviceNotRootedMessage);
+                    throw new RootShellException(Reason.NO_ROOT_ACCESS);
                 }
                 if (!isRunning()) {
                     String line;
                     while ((line = stderr.readLine()) != null) {
                         Log.w(TAG, "Root check returned an error: " + line);
                         if (line.contains("Permission denied"))
-                            throw new NoRootException(deviceNotRootedMessage);
+                            throw new RootShellException(Reason.NO_ROOT_ACCESS);
                     }
-                    throw new IOException(context.getString(R.string.shell_start_error, process.exitValue()));
+                    throw new RootShellException(Reason.SHELL_START_ERROR, process.exitValue());
                 }
-            } catch (final IOException | NoRootException e) {
+            } catch (final IOException | RootShellException e) {
                 stop();
                 throw e;
             }
@@ -187,13 +184,29 @@ public class RootShell {
         }
     }
 
-    public static class NoRootException extends Exception {
-        public NoRootException(final String message, final Throwable cause) {
-            super(message, cause);
+    public static class RootShellException extends Exception {
+        public enum Reason {
+            NO_ROOT_ACCESS,
+            SHELL_MARKER_COUNT_ERROR,
+            SHELL_EXIT_STATUS_READ_ERROR,
+            SHELL_START_ERROR,
+            CREATE_BIN_DIR_ERROR,
+            CREATE_TEMP_DIR_ERROR
         }
-
-        public NoRootException(final String message) {
-            super(message);
+        private final Reason reason;
+        private final Object[] format;
+        public RootShellException(final Reason reason, final Object ...format) {
+            this.reason = reason;
+            this.format = format;
+        }
+        public boolean isIORelated() {
+            return reason != Reason.NO_ROOT_ACCESS;
+        }
+        public Reason getReason() {
+            return reason;
+        }
+        public Object[] getFormat() {
+            return format;
         }
     }
 }
diff --git a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
index 82d1e94e..5483db35 100644
--- a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
+++ b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
@@ -13,7 +13,7 @@ import android.util.Log;
 import com.wireguard.android.Application;
 import com.wireguard.android.BuildConfig;
 import com.wireguard.android.R;
-import com.wireguard.android.util.RootShell.NoRootException;
+import com.wireguard.android.util.RootShell.RootShellException;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -63,7 +63,7 @@ public final class ToolsInstaller {
         return null;
     }
 
-    public int areInstalled() throws NoRootException {
+    public int areInstalled() throws RootShellException {
         if (INSTALL_DIR == null)
             return ERROR;
         final StringBuilder script = new StringBuilder();
@@ -81,6 +81,10 @@ public final class ToolsInstaller {
                 return willInstallAsMagiskModule() ? NO | MAGISK : NO | SYSTEM;
         } catch (final IOException ignored) {
             return ERROR;
+        } catch (final RootShellException e) {
+            if (e.isIORelated())
+                return ERROR;
+            throw e;
         }
     }
 
@@ -102,11 +106,11 @@ public final class ToolsInstaller {
         }
     }
 
-    public int install() throws NoRootException, IOException {
+    public int install() throws RootShellException, IOException {
         return willInstallAsMagiskModule() ? installMagisk() : installSystem();
     }
 
-    private int installMagisk() throws NoRootException, IOException {
+    private int installMagisk() throws RootShellException, IOException {
         extract();
         final StringBuilder script = new StringBuilder("set -ex; ");
 
@@ -125,10 +129,14 @@ public final class ToolsInstaller {
             return Application.getRootShell().run(null, script.toString()) == 0 ? YES | MAGISK : ERROR;
         } catch (final IOException ignored) {
             return ERROR;
+        } catch (final RootShellException e) {
+            if (e.isIORelated())
+                return ERROR;
+            throw e;
         }
     }
 
-    private int installSystem() throws NoRootException, IOException {
+    private int installSystem() throws RootShellException, IOException {
         if (INSTALL_DIR == null)
             return OsConstants.ENOENT;
         extract();
@@ -143,6 +151,10 @@ public final class ToolsInstaller {
             return Application.getRootShell().run(null, script.toString()) == 0 ? YES | SYSTEM : ERROR;
         } catch (final IOException ignored) {
             return ERROR;
+        } catch (final RootShellException e) {
+            if (e.isIORelated())
+                return ERROR;
+            throw e;
         }
     }