tools: build required tools with apk

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

.gitmodules

@@ -0,0 +1,9 @@
+[submodule "app/tools/libmnl"]
+	path = app/tools/libmnl
+	url = https://git.netfilter.org/libmnl/
+[submodule "app/tools/wireguard"]
+	path = app/tools/wireguard
+	url = https://git.zx2c4.com/WireGuard
+[submodule "app/tools/wireguard-android-integration"]
+	path = app/tools/wireguard-android-integration
+	url = https://git.zx2c4.com/android_kernel_wireguard

app/build.gradle

@@ -19,6 +19,11 @@ android {
         versionCode 100
         versionName '0.1.0'
     }
+    externalNativeBuild {
+        cmake {
+            path 'tools/CMakeLists.txt'
+        }
+    }
 }
 
 dependencies {

app/src/main/AndroidManifest.xml

@@ -6,6 +6,7 @@
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
 
     <application
+        android:extractNativeLibs="true"
         android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"

app/src/main/java/com/wireguard/android/backends/RootShell.java

@@ -22,7 +22,7 @@ class RootShell {
      * Setup commands that are run at the beginning of each root shell. The trap command ensures
      * access to the return value of the last command, since su itself always exits with 0.
      */
-    private static final String SETUP_TEMPLATE = "export TMPDIR=%s\ntrap 'echo $?' EXIT\n";
+    private static final String SETUP_TEMPLATE = "export PATH=\"%s/bin:$PATH\"; export TMPDIR=\"%s/temp\"; trap 'echo $?' EXIT; mkdir -p \"%s/bin\" \"%s/temp\"; ln -fs \"%s/libwg.so\" \"%s/bin/wg\" || exit 99; ln -fs \"%s/libwg-quick.so\" \"%s/bin/wg-quick\" || exit 99;";
     private static final String TAG = "RootShell";
     private static final Pattern ERRNO_EXTRACTOR = Pattern.compile("error=(\\d+)");
 
@@ -35,7 +35,8 @@ class RootShell {
 
     RootShell(final Context context, final String shell) {
         final String tmpdir = context.getCacheDir().getPath();
-        setupCommands = String.format(SETUP_TEMPLATE, tmpdir).getBytes(StandardCharsets.UTF_8);
+        final String fakelibdir = context.getApplicationInfo().nativeLibraryDir;
+        setupCommands = String.format(SETUP_TEMPLATE, tmpdir, tmpdir, tmpdir, tmpdir, fakelibdir, tmpdir, fakelibdir, tmpdir).getBytes(StandardCharsets.UTF_8);
         this.shell = shell;
     }
 

app/src/main/java/com/wireguard/android/backends/VpnService.java

@@ -261,17 +261,6 @@ public class VpnService extends Service
 
     private class ConfigEnabler extends AsyncTask<Void, Void, Integer> {
         private final Config config;
-        private final String[] paths = {
-                "/system/xbin",
-                "/system/sbin",
-                "/system/bin",
-                "/sbin",
-                "/bin",
-                "/xbin",
-                "/usr/sbin",
-                "/usr/bin",
-                "/usr/xbin",
-        };
 
         private ConfigEnabler(final Config config) {
             this.config = config;
@@ -281,19 +270,21 @@ public class VpnService extends Service
         protected Integer doInBackground(final Void... voids) {
             if (!new File("/sys/module/wireguard").exists())
                 return -0xfff0001;
-            if (!existsInPath("wg") || !existsInPath("wg-quick"))
-                return -0xfff0002;
             if (!existsInPath("su"))
-                return -0xfff0003;
+                return -0xfff0002;
             Log.i(TAG, "Running wg-quick up for " + config.getName());
             final File configFile = new File(getFilesDir(), config.getName() + ".conf");
             final int ret = rootShell.run(null, "wg-quick up '" + configFile.getPath() + "'");
             if (ret == 13 /* EPERM */)
-                return -0xfff0003;
+                return -0xfff0002;
             return ret;
         }
 
         private boolean existsInPath(final String file) {
+            final String pathEnv = System.getenv("PATH");
+            if (pathEnv == null)
+                return false;
+            final String[] paths = pathEnv.split(":");
             for (final String path : paths)
                 if (new File(path, file).exists())
                     return true;
@@ -307,9 +298,6 @@ public class VpnService extends Service
                 if (ret == -0xfff0001) {
                     startActivity(new Intent(getApplicationContext(), NotSupportedActivity.class));
                 } else if (ret == -0xfff0002) {
-                    Toast.makeText(getApplicationContext(), getString(R.string.error_missing),
-                            Toast.LENGTH_LONG).show();
-                } else if (ret == -0xfff0003) {
                     Toast.makeText(getApplicationContext(), getString(R.string.error_su),
                             Toast.LENGTH_LONG).show();
                 } else {

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

@@ -18,7 +18,6 @@
     <string name="enabled">Enabled</string>
     <string name="endpoint">Endpoint</string>
     <string name="error_down">Error bringing down WireGuard tunnel</string>
-    <string name="error_missing">Missing wg(8) and/or wg-quick(8) in PATH</string>
     <string name="error_su">WireGuard currently requires root access</string>
     <string name="error_up">Error bringing up WireGuard tunnel</string>
     <string name="generate">Generate</string>

app/tools/CMakeLists.txt

@@ -0,0 +1,9 @@
+cmake_minimum_required(VERSION 3.4.1)
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}")
+
+add_executable(libwg-quick.so wireguard-android-integration/wg-quick.c)
+SET_TARGET_PROPERTIES(libwg-quick.so PROPERTIES COMPILE_FLAGS "-O3 -std=gnu11 -Wall -pedantic -Wno-missing-field-initializers -DWG_CONFIG_SEARCH_PATHS=\"\\\"/data/data/com.wireguard.android/files\\\"\"")
+
+FILE(GLOB WG_SOURCES wireguard/src/tools/*.c libmnl/src/*.c)
+add_executable(libwg.so ${WG_SOURCES})
+SET_TARGET_PROPERTIES(libwg.so PROPERTIES COMPILE_FLAGS "'-I${CMAKE_CURRENT_SOURCE_DIR}libmnl/src/' '-I${CMAKE_CURRENT_SOURCE_DIR}/libmnl/include/' '-I${CMAKE_CURRENT_SOURCE_DIR}/wireguard/src/tools/' -O3 -std=gnu11 -D_GNU_SOURCE -DHAVE_VISIBILITY_HIDDEN -DRUNSTATEDIR=\"\\\"/data/data/com.wireguard.android/cache\\\"\" -Wno-pointer-arith -Wno-unused-parameter")

app/tools/libmnl

@@ -0,0 +1 @@
+Subproject commit 0930a63252958f40bb0f9d09de86985c25cea039

app/tools/wireguard

@@ -0,0 +1 @@
+Subproject commit 44f8e4d7d0b23c949850028fd9c502b73e15d288

app/tools/wireguard-android-integration

@@ -0,0 +1 @@
+Subproject commit a831aa82248009ba1ee95ac6ebdbeb5234aaffea