Have a collection of utilities for netd - NetdUtils

Some files which will be inside mainline module depend on
NetworkManagementService to talk to netd, but after they become
a part of mainline module, they cannot access @hide API of
NetworkManagementService.
So create a NetdUtils to help them to talk to netd.

Bug: 170598012
Test: atest CtsNetTestCasesLatestSdk NetdStaticLibTests
Change-Id: I8bee1204b9533b70844da0b3768427438fd0c890

1 files changed, 103 insertions, 0 deletions

diff --git a/client-libs/tests/unit/src/com/android/net/module/util/NetdUtilsTest.java b/client-libs/tests/unit/src/com/android/net/module/util/NetdUtilsTest.java
new file mode 100644
index 00000000..306b1bb2
--- /dev/null
+++ b/client-libs/tests/unit/src/com/android/net/module/util/NetdUtilsTest.java
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2021 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 com.android.net.module.util;
+
+import static com.android.testutils.MiscAsserts.assertThrows;
+
+import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.net.INetd;
+import android.net.InterfaceConfigurationParcel;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.Arrays;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class NetdUtilsTest {
+    @Mock private INetd mNetd;
+
+    private static final String IFACE = "TEST_IFACE";
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+    }
+
+    private void setupFlagsForInterfaceConfiguration(String[] flags) throws Exception {
+        final InterfaceConfigurationParcel config = new InterfaceConfigurationParcel();
+        config.flags = flags;
+        when(mNetd.interfaceGetCfg(eq(IFACE))).thenReturn(config);
+    }
+
+    private void verifyMethodsAndArgumentsOfSetInterface(boolean ifaceUp) throws Exception {
+        final String[] flagsContainDownAndUp = new String[] {"flagA", "down", "flagB", "up"};
+        final String[] flagsForInterfaceDown = new String[] {"flagA", "down", "flagB"};
+        final String[] flagsForInterfaceUp = new String[] {"flagA", "up", "flagB"};
+        final String[] expectedFinalFlags;
+        setupFlagsForInterfaceConfiguration(flagsContainDownAndUp);
+        if (ifaceUp) {
+            // "down" flag will be removed from flagsContainDownAndUp when interface is up. Set
+            // expectedFinalFlags to flagsForInterfaceUp.
+            expectedFinalFlags = flagsForInterfaceUp;
+            NetdUtils.setInterfaceUp(mNetd, IFACE);
+        } else {
+            // "up" flag will be removed from flagsContainDownAndUp when interface is down. Set
+            // expectedFinalFlags to flagsForInterfaceDown.
+            expectedFinalFlags = flagsForInterfaceDown;
+            NetdUtils.setInterfaceDown(mNetd, IFACE);
+        }
+        verify(mNetd).interfaceSetCfg(
+                argThat(config ->
+                        // Check if actual flags are the same as expected flags.
+                        // TODO: Have a function in MiscAsserts to check if two arrays are the same.
+                        CollectionUtils.all(Arrays.asList(expectedFinalFlags),
+                                flag -> Arrays.asList(config.flags).contains(flag))
+                        && CollectionUtils.all(Arrays.asList(config.flags),
+                                flag -> Arrays.asList(expectedFinalFlags).contains(flag))));
+    }
+
+    @Test
+    public void testSetInterfaceUp() throws Exception {
+        verifyMethodsAndArgumentsOfSetInterface(true /* ifaceUp */);
+    }
+
+    @Test
+    public void testSetInterfaceDown() throws Exception {
+        verifyMethodsAndArgumentsOfSetInterface(false /* ifaceUp */);
+    }
+
+    @Test
+    public void testRemoveAndAddFlags() throws Exception {
+        final String[] flags = new String[] {"flagA", "down", "flagB"};
+        // Add an invalid flag and expect to get an IllegalStateException.
+        assertThrows(IllegalStateException.class,
+                () -> NetdUtils.removeAndAddFlags(flags, "down" /* remove */, "u p" /* add */));
+    }
+}
+