Add CTS test for android.net.VpnService.

Bug: 5910784
Change-Id: Icb3d874d4d0917f739bd2638596f28df2a7d206e
diff --git a/tests/tests/net/src/android/net/cts/VpnServiceTest.java b/tests/tests/net/src/android/net/cts/VpnServiceTest.java
new file mode 100644
index 0000000..9e35375
--- /dev/null
+++ b/tests/tests/net/src/android/net/cts/VpnServiceTest.java
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.net.cts;
+
+import android.content.Intent;
+import android.net.VpnService;
+import android.os.ParcelFileDescriptor;
+import android.test.AndroidTestCase;
+
+import java.io.File;
+import java.net.DatagramSocket;
+import java.net.Socket;
+
+/**
+ * VpnService API is built with security in mind. However, its security also
+ * blocks us from writing tests for positive cases. For now we only test for
+ * negative cases, and we will try to cover the rest in the future.
+ */
+public class VpnServiceTest extends AndroidTestCase {
+
+    private static final String TAG = VpnServiceTest.class.getSimpleName();
+
+    private VpnService mVpnService = new VpnService();
+
+    public void testPrepare() throws Exception {
+        // Should never return null since we are not prepared.
+        Intent intent = VpnService.prepare(mContext);
+        assertNotNull(intent);
+
+        // Should be always resolved by only one activity.
+        int count = mContext.getPackageManager().queryIntentActivities(intent, 0).size();
+        assertEquals(count, 1);
+    }
+
+    public void testEstablish() throws Exception {
+        ParcelFileDescriptor descriptor = null;
+        try {
+            // Should always return null since we are not prepared.
+            descriptor = mVpnService.new Builder().addAddress("8.8.8.8", 30).establish();
+            assertNull(descriptor);
+        } finally {
+            try {
+                descriptor.close();
+            } catch (Exception e) {
+                // ignore
+            }
+        }
+    }
+
+    public void testProtect_DatagramSocket() throws Exception {
+        DatagramSocket socket = new DatagramSocket();
+        try {
+            // Should always return false since we are not prepared.
+            assertFalse(mVpnService.protect(socket));
+        } finally {
+            try {
+                socket.close();
+            } catch (Exception e) {
+                // ignore
+            }
+        }
+    }
+
+    public void testProtect_Socket() throws Exception {
+        Socket socket = new Socket();
+        try {
+            // Should always return false since we are not prepared.
+            assertFalse(mVpnService.protect(socket));
+        } finally {
+            try {
+                socket.close();
+            } catch (Exception e) {
+                // ignore
+            }
+        }
+    }
+
+    public void testProtect_int() throws Exception {
+        DatagramSocket socket = new DatagramSocket();
+        ParcelFileDescriptor descriptor = ParcelFileDescriptor.fromDatagramSocket(socket);
+        try {
+            // Should always return false since we are not prepared.
+            assertFalse(mVpnService.protect(descriptor.getFd()));
+        } finally {
+            try {
+                descriptor.close();
+            } catch (Exception e) {
+                // ignore
+            }
+            try {
+                socket.close();
+            } catch (Exception e) {
+                // ignore
+            }
+        }
+    }
+
+    public void testTunDevice() throws Exception {
+        File file = new File("/dev/tun");
+        assertTrue(file.exists());
+        assertFalse(file.isFile());
+        assertFalse(file.isDirectory());
+        assertFalse(file.canExecute());
+        assertFalse(file.canRead());
+        assertFalse(file.canWrite());
+    }
+}