diff options
Diffstat (limited to 'app/src/main/java/com/wireguard/android/util/RootShell.java')
| -rw-r--r-- | app/src/main/java/com/wireguard/android/util/RootShell.java | 208 |
1 files changed, 87 insertions, 121 deletions
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 f8b5bb9f..910fa7ae 100644 --- a/app/src/main/java/com/wireguard/android/util/RootShell.java +++ b/app/src/main/java/com/wireguard/android/util/RootShell.java @@ -1,8 +1,6 @@ package com.wireguard.android.util; import android.content.Context; -import android.system.ErrnoException; -import android.system.OsConstants; import android.util.Log; import com.wireguard.android.Application.ApplicationContext; @@ -10,16 +8,14 @@ import com.wireguard.android.Application.ApplicationScope; import com.wireguard.android.R; import java.io.BufferedReader; -import java.io.BufferedWriter; import java.io.File; +import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.nio.charset.StandardCharsets; import java.util.Collection; import java.util.UUID; -import java.util.regex.Matcher; -import java.util.regex.Pattern; import javax.inject.Inject; @@ -29,30 +25,29 @@ import javax.inject.Inject; @ApplicationScope public class RootShell { - private static final Pattern ERRNO_EXTRACTOR = Pattern.compile("error=(\\d+)"); + private static final String SU = "su"; private static final String TAG = "WireGuard/" + RootShell.class.getSimpleName(); - private final String exceptionMessage; + private final String deviceNotRootedMessage; + private final File localBinaryDir; + private final File localTemporaryDir; private final String preamble; private Process process; private BufferedReader stderr; - private BufferedWriter stdin; + private OutputStreamWriter stdin; private BufferedReader stdout; @Inject public RootShell(@ApplicationContext final Context context) { - final File binDir = new File(context.getCacheDir(), "bin"); - final File tmpDir = new File(context.getCacheDir(), "tmp"); - - if (!(binDir.isDirectory() || binDir.mkdirs()) - || !(tmpDir.isDirectory() || tmpDir.mkdirs())) - throw new RuntimeException(new IOException("Cannot create binary dir/TMPDIR")); - - exceptionMessage = context.getString(R.string.error_root); - preamble = String.format("export PATH=\"%s:$PATH\" TMPDIR='%s'; id;\n", binDir, tmpDir); + deviceNotRootedMessage = context.getString(R.string.error_root); + final File cacheDir = context.getCacheDir(); + localBinaryDir = new File(cacheDir, "bin"); + localTemporaryDir = new File(cacheDir, "tmp"); + preamble = String.format("export PATH=\"%s:$PATH\" TMPDIR='%s'; id -u\n", + localBinaryDir, localTemporaryDir); } - private static boolean isExecutable(final String name) { + private static boolean isExecutableInPath(final String name) { final String path = System.getenv("PATH"); if (path == null) return false; @@ -62,61 +57,18 @@ public class RootShell { return false; } - private void ensureRoot() throws ErrnoException, IOException, NoRootException { - try { - if (process != null) { - process.exitValue(); - process = null; - } - } catch (IllegalThreadStateException e) { - return; - } - - if (!isExecutable("su")) - throw new NoRootException(exceptionMessage); - + public boolean isRunning() { try { - final ProcessBuilder builder = new ProcessBuilder(); - builder.environment().put("LANG", "C"); - builder.command("su"); - process = builder.start(); - stdin = new BufferedWriter(new OutputStreamWriter(process.getOutputStream(), StandardCharsets.UTF_8)); - stdout = new BufferedReader(new InputStreamReader(process.getInputStream(), StandardCharsets.UTF_8)); - stderr = new BufferedReader(new InputStreamReader(process.getErrorStream(), StandardCharsets.UTF_8)); - - Log.d(TAG, "New root shell, sending preamble: " + preamble); - stdin.write(preamble); - stdin.flush(); - final String id = stdout.readLine(); - - try { - int errno = process.exitValue(); - String line; - while ((line = stderr.readLine()) != null) { - if (line.contains("Permission denied")) - throw new NoRootException(exceptionMessage); - } - throw new ErrnoException("Unknown error when obtaining root access", errno); - } catch (IllegalThreadStateException e) { - // We're alive, so keep executing. + // Throws an exception if the process hasn't finished yet. + synchronized (this) { + if (process != null) + process.exitValue(); } - - if (id == null || !id.contains("uid=0")) - throw new NoRootException(exceptionMessage); - } catch (Exception e) { - Log.w(TAG, "Session failed with exception", e); - process.destroy(); - process = null; - final Matcher match = ERRNO_EXTRACTOR.matcher(e.toString()); - if (match.find()) { - final int errno = Integer.valueOf(match.group(1)); - if (errno == OsConstants.EACCES) - throw new NoRootException(exceptionMessage); - else - throw new ErrnoException("Unknown error when obtaining root access", errno); - } - throw e; + } catch (final IllegalThreadStateException ignored) { + // The existing process is still running. + return true; } + return false; } /** @@ -125,78 +77,92 @@ public class RootShell { * @param output Lines read from stdout are appended to this list. Pass null if the * output from the shell is not important. * @param command Command to run as root. - * @return The exit value of the last command run, or -1 if there was an internal error. + * @return The exit value of the command. */ public synchronized int run(final Collection<String> output, final String command) - throws ErrnoException, IOException, NoRootException { - ensureRoot(); - - StringBuilder builder = new StringBuilder(); + throws IOException, NoRootException { + start(); final String marker = UUID.randomUUID().toString(); - final String begin = marker + " begin"; - final String end = marker + " end"; - - builder.append(String.format("echo '%s';", begin)); - builder.append(String.format("echo '%s' >&2;", begin)); - - builder.append('('); - builder.append(command); - builder.append(");"); - - builder.append("ret=$?;"); - builder.append(String.format("echo '%s' $ret;", end)); - builder.append(String.format("echo '%s' $ret >&2;", end)); - - builder.append('\n'); - - Log.v(TAG, "executing: " + command); - stdin.write(builder.toString()); + final String script = '(' + command + "); ret=$?; echo " + marker + " $ret; " + + "echo " + marker + " $ret >&2\n"; + Log.v(TAG, "executing: " + script); + stdin.write(script); stdin.flush(); - String line; - boolean first = true; - int errnoStdout = -1, errnoStderr = -2; - int beginEnds = 0; + int errnoStdout = Integer.MIN_VALUE; + int errnoStderr = Integer.MAX_VALUE; while ((line = stdout.readLine()) != null) { - if (first) { - first = false; - if (!line.startsWith(begin)) - throw new ErrnoException("Could not find begin marker", OsConstants.EBADMSG); - ++beginEnds; - continue; - } - if (line.startsWith(end) && line.length() > end.length() + 1) { - errnoStdout = Integer.valueOf(line.substring(end.length() + 1)); - ++beginEnds; + if (line.startsWith(marker) && line.length() > marker.length() + 1) { + errnoStdout = Integer.valueOf(line.substring(marker.length() + 1)); break; } if (output != null) output.add(line); Log.v(TAG, "stdout: " + line); } - first = true; while ((line = stderr.readLine()) != null) { - if (first) { - first = false; - if (!line.startsWith(begin)) - throw new ErrnoException("Could not find begin marker", OsConstants.EBADMSG); - ++beginEnds; - continue; - } - if (line.startsWith(end) && line.length() > end.length() + 1) { - errnoStderr = Integer.valueOf(line.substring(end.length() + 1)); - ++beginEnds; + if (line.startsWith(marker) && line.length() > marker.length() + 1) { + errnoStderr = Integer.valueOf(line.substring(marker.length() + 1)); break; } Log.v(TAG, "stderr: " + line); } - if (errnoStderr != errnoStdout || beginEnds != 4) - throw new ErrnoException("Incorrect errno reporting", OsConstants.EBADMSG); - + if (errnoStdout != errnoStderr) + throw new IOException("Unable to read exit status"); + Log.v(TAG, "exit: " + errnoStdout); return errnoStdout; } + public synchronized void start() throws IOException, NoRootException { + if (isRunning()) + return; + if (!localBinaryDir.isDirectory() && !localBinaryDir.mkdirs()) + throw new FileNotFoundException("Could not create local binary directory"); + if (!localTemporaryDir.isDirectory() && !localTemporaryDir.mkdirs()) + throw new FileNotFoundException("Could not create local temporary directory"); + if (!isExecutableInPath(SU)) + throw new NoRootException(deviceNotRootedMessage); + final ProcessBuilder builder = new ProcessBuilder().command(SU); + builder.environment().put("LC_ALL", "C"); + process = builder.start(); + stdin = new OutputStreamWriter(process.getOutputStream(), StandardCharsets.UTF_8); + stdout = new BufferedReader(new InputStreamReader(process.getInputStream(), + StandardCharsets.UTF_8)); + stderr = new BufferedReader(new InputStreamReader(process.getErrorStream(), + StandardCharsets.UTF_8)); + stdin.write(preamble); + stdin.flush(); + // Check that the shell started successfully. + final String uid = stdout.readLine(); + if (!"0".equals(uid)) { + Log.w(TAG, "Root check did not return correct UID: " + uid); + throw new NoRootException(deviceNotRootedMessage); + } + 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 IOException("Shell failed to start: " + process.exitValue()); + } + } + + public void stop() throws IOException { + synchronized (this) { + if (process != null) { + process.destroy(); + process = null; + } + } + } + public static class NoRootException extends Exception { + public NoRootException(final String message, final Throwable cause) { + super(message, cause); + } + public NoRootException(final String message) { super(message); } |