ToolsInstaller: Extract to its own classes

Signed-off-by: Samuel Holland <samuel@sholland.org>

1 files changed, 70 insertions, 0 deletions

diff --git a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
new file mode 100644
index 00000000..8496a310
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
@@ -0,0 +1,70 @@
+package com.wireguard.android.util;
+
+import android.content.Context;
+import android.system.OsConstants;
+
+import com.wireguard.android.Application.ApplicationContext;
+import com.wireguard.android.Application.ApplicationScope;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.List;
+
+import javax.inject.Inject;
+
+/**
+ * Helper to install WireGuard tools to the system partition.
+ */
+
+@ApplicationScope
+public final class ToolsInstaller {
+    private static final String[][] EXECUTABLES = {
+            {"libwg.so", "wg"},
+            {"libwg-quick.so", "wg-quick"},
+    };
+    private static final File[] INSTALL_DIRS = {
+            new File("/system/xbin"),
+            new File("/system/bin"),
+    };
+
+    private final String nativeLibraryDir;
+    private final RootShell rootShell;
+
+    @Inject
+    public ToolsInstaller(@ApplicationContext final Context context, final RootShell rootShell) {
+        nativeLibraryDir = context.getApplicationInfo().nativeLibraryDir;
+        this.rootShell = rootShell;
+    }
+
+    private static File getInstallDir() {
+        final String path = System.getenv("PATH");
+        if (path == null)
+            return INSTALL_DIRS[0];
+        final List<String> paths = Arrays.asList(path.split(":"));
+        for (final File dir : INSTALL_DIRS)
+            if (paths.contains(dir.getPath()) && dir.isDirectory())
+                return dir;
+        return null;
+    }
+
+    public int install() {
+        final File installDir = getInstallDir();
+        if (installDir == null)
+            return OsConstants.ENOENT;
+        final StringBuilder script = new StringBuilder("set -ex; ");
+        for (final String[] names : EXECUTABLES) {
+            script.append(String.format("cmp -s '%s' '%s' && ",
+                    new File(nativeLibraryDir, names[0]),
+                    new File(installDir, names[1])));
+        }
+        script.append("exit ").append(OsConstants.EALREADY).append("; ");
+        script.append("trap 'mount -o ro,remount /system' EXIT; mount -o rw,remount /system; ");
+        for (final String[] names : EXECUTABLES) {
+            script.append(String.format("cp %s %s; chmod 755 %s; ",
+                    new File(nativeLibraryDir, names[0]),
+                    new File(installDir, names[1]),
+                    new File(installDir, names[1])));
+        }
+        return rootShell.run(null, script.toString());
+    }
+}