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authorJason A. Donenfeld <Jason@zx2c4.com>2018-01-08 19:46:51 +0100
committerJason A. Donenfeld <Jason@zx2c4.com>2018-01-08 19:46:51 +0100
commiteb37b3a5ccc527936ef495e893655fca60115e2e (patch)
tree6e7ff0de24f3113077b9308baf0e69fcbc21ece4 /app/src/main/java/com/wireguard
parentd0b7e9fe0e2725064bbb34aaa37def91ef75ef01 (diff)
RootShell: multiplex commands
Diffstat (limited to 'app/src/main/java/com/wireguard')
-rw-r--r--app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java13
-rw-r--r--app/src/main/java/com/wireguard/android/fragment/TunnelController.java3
-rw-r--r--app/src/main/java/com/wireguard/android/util/RootShell.java174
-rw-r--r--app/src/main/java/com/wireguard/android/util/ToolsInstaller.java6
4 files changed, 149 insertions, 47 deletions
diff --git a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
index 5eaf437d..ab6a6199 100644
--- a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
+++ b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
@@ -52,8 +52,12 @@ public final class WgQuickBackend implements Backend {
public Set<String> enumerate() {
final List<String> output = new ArrayList<>();
// Don't throw an exception here or nothing will show up in the UI.
- if (rootShell.run(output, "wg show interfaces") != 0 || output.isEmpty())
+ try {
+ if (rootShell.run(output, "wg show interfaces") != 0 || output.isEmpty())
+ return Collections.emptySet();
+ } catch (Exception e) {
return Collections.emptySet();
+ }
// wg puts all interface names on the same line. Split them into separate elements.
return Stream.of(output.get(0).split(" ")).collect(Collectors.toUnmodifiableSet());
}
@@ -86,11 +90,8 @@ public final class WgQuickBackend implements Backend {
} else {
result = rootShell.run(null, String.format("wg-quick down '%s'", tunnel.getName()));
}
- if (result != 0) {
- final String message = result == OsConstants.EACCES ?
- "Root access unavailable" : "wg-quick failed";
- throw new Exception(message);
- }
+ if (result != 0)
+ throw new Exception("wg-quick failed");
return getState(tunnel);
}
}
diff --git a/app/src/main/java/com/wireguard/android/fragment/TunnelController.java b/app/src/main/java/com/wireguard/android/fragment/TunnelController.java
index 668e74c0..77d8d320 100644
--- a/app/src/main/java/com/wireguard/android/fragment/TunnelController.java
+++ b/app/src/main/java/com/wireguard/android/fragment/TunnelController.java
@@ -19,6 +19,7 @@ import com.wireguard.android.databinding.TunnelListItemBinding;
import com.wireguard.android.model.Tunnel;
import com.wireguard.android.model.Tunnel.State;
import com.wireguard.android.util.ExceptionLoggers;
+import com.wireguard.android.util.RootShell;
/**
* Helper method shared by TunnelListFragment and TunnelDetailFragment.
@@ -60,6 +61,8 @@ public final class TunnelController {
// Make links work.
((TextView) dialog.findViewById(android.R.id.message))
.setMovementMethod(LinkMovementMethod.getInstance());
+ } else if (throwable instanceof RootShell.NoRootException) {
+ Snackbar.make(view, R.string.error_rootshell, Snackbar.LENGTH_LONG).show();
} else {
final String message =
context.getString(checked ? R.string.error_up : R.string.error_down) + ": "
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 6c90118e..9c2f3574 100644
--- a/app/src/main/java/com/wireguard/android/util/RootShell.java
+++ b/app/src/main/java/com/wireguard/android/util/RootShell.java
@@ -1,19 +1,22 @@
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;
import com.wireguard.android.Application.ApplicationScope;
+import java.io.BufferedWriter;
import java.io.BufferedReader;
+import java.io.OutputStreamWriter;
+import java.io.InputStreamReader;
import java.io.File;
import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.List;
+import java.util.UUID;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
@@ -38,6 +41,11 @@ public class RootShell {
private final String preamble;
+ private BufferedWriter stdin;
+ private BufferedReader stdout;
+ private BufferedReader stderr;
+ private Process process;
+
@Inject
public RootShell(@ApplicationContext final Context context) {
final String binDir = context.getCacheDir().getPath() + "/bin";
@@ -54,6 +62,7 @@ public class RootShell {
builder.append(String.format("[ %s -ef %s ] || ln -sf %s %s || exit 31;", arg1, arg2, arg1, arg2));
}
builder.append(String.format("export PATH=\"%s:$PATH\" TMPDIR=\"%s\";", binDir, tmpDir));
+ builder.append("id;\n");
preamble = builder.toString();
}
@@ -68,6 +77,63 @@ public class RootShell {
return false;
}
+ private void ensureRoot() throws Exception {
+ try {
+ if (process != null) {
+ process.exitValue();
+ process = null;
+ }
+ } catch (IllegalThreadStateException e) {
+ return;
+ }
+
+ if (!isExecutable("su"))
+ throw new NoRootException();
+
+ 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();
+ }
+ throw new ErrnoException("Unknown error when obtaining root access", errno);
+ } catch (IllegalThreadStateException e) {
+ // We're alive, so keep executing.
+ }
+
+ if (id == null || !id.contains("uid=0"))
+ throw new NoRootException();
+ } 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();
+ else
+ throw new ErrnoException("Unknown error when obtaining root access", errno);
+ }
+ throw e;
+ }
+ }
+
/**
* Run a command in a root shell.
*
@@ -76,46 +142,74 @@ public class RootShell {
* @param command Command to run as root.
* @return The exit value of the last command run, or -1 if there was an internal error.
*/
- public int run(final List<String> output, final String command) {
- int exitValue = -1;
- if (!isExecutable("su"))
- return OsConstants.EACCES;
- try {
- final ProcessBuilder builder = new ProcessBuilder();
- builder.environment().put("LANG", "C");
- builder.command("su", "-c", preamble + command);
- final Process process = builder.start();
- Log.d(TAG, "Running: " + command);
- final InputStream stdout = process.getInputStream();
- final InputStream stderr = process.getErrorStream();
- final BufferedReader stdoutReader =
- new BufferedReader(new InputStreamReader(stdout, StandardCharsets.UTF_8));
- final BufferedReader stderrReader =
- new BufferedReader(new InputStreamReader(stderr, StandardCharsets.UTF_8));
- String line;
- while ((line = stdoutReader.readLine()) != null) {
- if (output != null)
- output.add(line);
- Log.v(TAG, "stdout: " + line);
+ public int run(final List<String> output, final String command) throws Exception {
+ ensureRoot();
+
+ StringBuilder builder = new StringBuilder();
+ 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());
+ stdin.flush();
+
+ String line;
+ boolean first = true;
+ int errnoStdout = -1, errnoStderr = -2;
+ int beginEnds = 0;
+ 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;
}
- int linesOfStderr = 0;
- String stderrLast = null;
- while ((line = stderrReader.readLine()) != null) {
- ++linesOfStderr;
- stderrLast = line;
- Log.v(TAG, "stderr: " + line);
+ if (line.startsWith(end) && line.length() > end.length()) {
+ errnoStdout = Integer.valueOf(line.substring(end.length() + 1));
+ ++beginEnds;
+ break;
}
- exitValue = process.waitFor();
- process.destroy();
- if (exitValue == 1 && linesOfStderr == 1 && stderrLast.equals("Permission denied"))
- exitValue = OsConstants.EACCES;
- Log.d(TAG, "Exit status: " + exitValue);
- } catch (IOException | InterruptedException e) {
- Log.w(TAG, "Session failed with exception", e);
- final Matcher match = ERRNO_EXTRACTOR.matcher(e.toString());
- if (match.find())
- exitValue = Integer.valueOf(match.group(1));
+ if (output != null)
+ output.add(line);
+ Log.v(TAG, "stdout: " + line);
}
- return exitValue;
+ 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()) {
+ errnoStderr = Integer.valueOf(line.substring(end.length() + 1));
+ ++beginEnds;
+ break;
+ }
+ Log.v(TAG, "stderr: " + line);
+ }
+ if (errnoStderr != errnoStdout || beginEnds != 4)
+ throw new ErrnoException("Incorrect errno reporting", OsConstants.EBADMSG);
+
+ return errnoStdout;
+ }
+
+ public class NoRootException extends Exception {
}
}
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 8496a310..aeffa364 100644
--- a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
+++ b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
@@ -65,6 +65,10 @@ public final class ToolsInstaller {
new File(installDir, names[1]),
new File(installDir, names[1])));
}
- return rootShell.run(null, script.toString());
+ try {
+ return rootShell.run(null, script.toString());
+ } catch (Exception e) {
+ return OsConstants.EACCES;
+ }
}
}