1 files changed, 158 insertions, 0 deletions
diff --git a/tunnel/src/main/java/com/wireguard/android/backend/WgQuickBackend.java b/tunnel/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
new file mode 100644
index 00000000..9695aab7
--- /dev/null
+++ b/tunnel/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
@@ -0,0 +1,158 @@
+/*
+ * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.wireguard.android.backend;
+
+import androidx.annotation.Nullable;
+
+import android.content.Context;
+import android.util.Log;
+
+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;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.HashMap;
+
+import java9.util.stream.Collectors;
+import java9.util.stream.Stream;
+
+/**
+ * WireGuard backend that uses {@code wg-quick} to implement tunnel configuration.
+ */
+
+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<>();
+
+    public WgQuickBackend(final Context context, final RootShell rootShell, final ToolsInstaller toolsInstaller) {
+        localTemporaryDir = new File(context.getCacheDir(), "tmp");
+        this.rootShell = rootShell;
+        this.toolsInstaller = toolsInstaller;
+    }
+
+    @Override
+    public Set<String> getRunningTunnelNames() {
+        final List<String> output = new ArrayList<>();
+        // Don't throw an exception here or nothing will show up in the UI.
+        try {
+            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);
+            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());
+    }
+
+    @Override
+    public State getState(final Tunnel tunnel) {
+        return getRunningTunnelNames().contains(tunnel.getName()) ? State.UP : State.DOWN;
+    }
+
+    @Override
+    public Statistics getStatistics(final Tunnel tunnel) {
+        final Statistics stats = new Statistics();
+        final Collection<String> output = new ArrayList<>();
+        try {
+            if (rootShell.run(output, String.format("wg show '%s' transfer", tunnel.getName())) != 0)
+                return stats;
+        } catch (final Exception ignored) {
+            return stats;
+        }
+        for (final String line : output) {
+            final String[] parts = line.split("\\t");
+            if (parts.length != 3)
+                continue;
+            try {
+                stats.add(Key.fromBase64(parts[0]), Long.parseLong(parts[1]), Long.parseLong(parts[2]));
+            } catch (final Exception ignored) {
+            }
+        }
+        return stats;
+    }
+
+    @Override
+    public String getVersion() throws Exception {
+        final List<String> output = new ArrayList<>();
+        if (rootShell.run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
+            throw new BackendException(Reason.UNKNOWN_KERNEL_MODULE_NAME);
+        return output.get(0);
+    }
+
+    @Override
+    public State setState(final Tunnel tunnel, State state, @Nullable final Config config) throws Exception {
+        final State originalState = getState(tunnel);
+        final Config originalConfig = runningConfigs.get(tunnel);
+
+        if (state == State.TOGGLE)
+            state = originalState == State.UP ? State.DOWN : State.UP;
+        if ((state == State.UP && originalState == State.UP && originalConfig != null && originalConfig == config) ||
+                (state == State.DOWN && originalState == State.DOWN))
+            return originalState;
+        if (state == State.UP) {
+            toolsInstaller.ensureToolsAvailable();
+            if (originalState == State.UP)
+                setStateInternal(tunnel, originalConfig == null ? config : originalConfig, State.DOWN);
+            try {
+                setStateInternal(tunnel, config, State.UP);
+            } catch(final Exception e) {
+                if (originalState == State.UP && originalConfig != null)
+                    setStateInternal(tunnel, originalConfig, State.UP);
+                throw e;
+            }
+        } else if (state == State.DOWN) {
+            setStateInternal(tunnel, originalConfig == null ? config : originalConfig, State.DOWN);
+        }
+        return state;
+    }
+
+    private void setStateInternal(final Tunnel tunnel, @Nullable final Config config, final State state) throws Exception {
+        Log.i(TAG, "Bringing tunnel " + tunnel.getName() + " " + state);
+
+        Objects.requireNonNull(config, "Trying to set state up with a null config");
+
+        final File tempFile = new File(localTemporaryDir, tunnel.getName() + ".conf");
+        try (final FileOutputStream stream = new FileOutputStream(tempFile, false)) {
+            stream.write(config.toWgQuickString().getBytes(StandardCharsets.UTF_8));
+        }
+        String command = String.format("wg-quick %s '%s'",
+                state.toString().toLowerCase(Locale.ENGLISH), tempFile.getAbsolutePath());
+        if (state == State.UP)
+            command = "cat /sys/module/wireguard/version && " + command;
+        final int result = rootShell.run(null, command);
+        // noinspection ResultOfMethodCallIgnored
+        tempFile.delete();
+        if (result != 0)
+            throw new BackendException(Reason.WG_QUICK_CONFIG_ERROR_CODE, result);
+
+        if (state == State.UP)
+            runningConfigs.put(tunnel, config);
+        else
+            runningConfigs.remove(tunnel);
+
+        tunnel.onStateChange(state);
+    }
+}