Settings: add version

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

app/src/main/java/com/wireguard/android/backend/GoBackend.java

@@ -56,6 +56,10 @@ public final class GoBackend implements Backend {
 
     private static native int wgTurnOn(String ifName, int tunFd, String settings);
 
+    private static native String wgVersion();
+
+    public static String getVersion() { return wgVersion(); }
+
     @Override
     public Config applyConfig(final Tunnel tunnel, final Config config) throws Exception {
         if (tunnel.getState() == State.UP) {

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

@@ -0,0 +1,56 @@
+/*
+ * Copyright © 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+package com.wireguard.android.preference;
+
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+import android.support.v7.preference.Preference;
+import android.util.AttributeSet;
+
+import com.wireguard.android.Application;
+import com.wireguard.android.BuildConfig;
+import com.wireguard.android.R;
+import com.wireguard.android.backend.GoBackend;
+import com.wireguard.android.backend.WgQuickBackend;
+
+public class VersionPreference extends Preference {
+    private String versionSummary;
+
+    public VersionPreference(final Context context, final AttributeSet attrs) {
+        super(context, attrs);
+
+        if (Application.getComponent().getBackendType() == GoBackend.class) {
+            versionSummary = getContext().getString(R.string.version_userspace_summary, GoBackend.getVersion());
+        } else if (Application.getComponent().getBackendType() == WgQuickBackend.class) {
+            Application.getComponent().getToolsInstaller().getVersion().whenComplete((version, exception) -> {
+                if (exception == null)
+                    versionSummary = getContext().getString(R.string.version_kernel_summary, version);
+                else
+                    versionSummary = getContext().getString(R.string.version_kernel_unknown_summary);
+                notifyChanged();
+            });
+        }
+    }
+
+    @Override
+    public CharSequence getSummary() {
+        return versionSummary;
+    }
+
+    @Override
+    public CharSequence getTitle() {
+        return getContext().getString(R.string.version_title, BuildConfig.VERSION_NAME);
+    }
+
+    @Override
+    protected void onClick() {
+        final Intent intent = new Intent(Intent.ACTION_VIEW);
+        intent.setData(Uri.parse("https://www.wireguard.com/"));
+        getContext().startActivity(intent);
+    }
+
+}

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

@@ -10,6 +10,7 @@ import android.content.Context;
 import android.system.OsConstants;
 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.util.RootShell.NoRootException;
@@ -17,11 +18,14 @@ import com.wireguard.android.util.RootShell.NoRootException;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 import javax.inject.Inject;
 
+import java9.util.concurrent.CompletionStage;
+
 /**
  * Helper to install WireGuard tools to the system partition.
  */
@@ -52,6 +56,15 @@ public final class ToolsInstaller {
         this.rootShell = rootShell;
     }
 
+    public CompletionStage<String> getVersion() {
+        return Application.getComponent().getAsyncWorker().supplyAsync(() -> {
+            final ArrayList<String> output = new ArrayList<>();
+            if (rootShell.run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
+                throw new RuntimeException("Unable to determine kernel module version");
+            return output.get(0);
+        });
+    }
+
     private static File getInstallDir() {
         final String path = System.getenv("PATH");
         if (path == null)

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

@@ -74,5 +74,9 @@
     <string name="tunnel_create_success">Successfully created tunnel “%s”</string>
     <string name="tunnel_rename_error">Unable to rename tunnel: %s</string>
     <string name="tunnel_rename_success">Successfully renamed tunnel to “%s”</string>
+    <string name="version_title">WireGuard for Android v%s"</string>
+    <string name="version_kernel_summary">Using kernel module implementation v%s</string>
+    <string name="version_kernel_unknown_summary">Using unknown kernel module implementation</string>
+    <string name="version_userspace_summary">Using Go userspace implementation v%s</string>
     <string name="zip_exporter_title">Export tunnels to zip file</string>
 </resources>

app/src/main/res/xml/preferences.xml

@@ -13,4 +13,5 @@
         android:summaryOn="@string/dark_theme_summary_on"
         android:summaryOff="@string/dark_theme_summary_off"
         android:title="@string/dark_theme_title" />
+    <com.wireguard.android.preference.VersionPreference />
 </PreferenceScreen>

app/tools/libwg-go/src/git.zx2c4.com/wireguard-go/api-android.go

@@ -160,4 +160,9 @@ func wgGetSocketV6(tunnelHandle int32) int32 {
 	return fd
 }
 
+//export wgVersion
+func wgVersion() string {
+	return WireGuardGoVersion
+}
+
 func main() {}

app/tools/libwg-go/src/git.zx2c4.com/wireguard-go/jni.c

@@ -4,12 +4,15 @@
  */
 
 #include <jni.h>
+#include <stdlib.h>
+#include <string.h>
 
 struct go_string { const char *str; long n; };
 extern int wgTurnOn(struct go_string ifname, int tun_fd, struct go_string settings);
 extern void wgTurnOff(int handle);
 extern int wgGetSocketV4(int handle);
 extern int wgGetSocketV6(int handle);
+extern struct go_string wgVersion();
 
 JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOn(JNIEnv *env, jclass c, jstring ifname, jint tun_fd, jstring settings)
 {
@@ -43,3 +46,17 @@ JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgGetSocketV
 {
 	return wgGetSocketV6(handle);
 }
+
+JNIEXPORT jstring JNICALL Java_com_wireguard_android_backend_GoBackend_wgVersion(JNIEnv *env, jclass c)
+{
+	struct go_string s = wgVersion();
+	char *cstr = malloc(s.n + 1);
+	if (!cstr)
+		return NULL;
+	jstring ret;
+	memcpy(cstr, s.str, s.n);
+	cstr[s.n] = '\0';
+	ret = (*env)->NewStringUTF(env, cstr);
+	free(cstr);
+	return ret;
+}