Create base class that sets up test network

This class will be extended by both IkeSessionParamsTest and
IkeSessionTestBase

Bug: 148689509
Test: atest CtsIkeTestCases
Change-Id: I98979758a7a684219e35c02ded93224ea172d44f
Merged-In: I98979758a7a684219e35c02ded93224ea172d44f
(cherry picked from commit 50908b926635355f0753b7388f96b684f6be351d)
diff --git a/tests/cts/net/ipsec/src/android/net/ipsec/ike/cts/IkeSessionParamsTestBase.java b/tests/cts/net/ipsec/src/android/net/ipsec/ike/cts/IkeSessionParamsTestBase.java
new file mode 100644
index 0000000..c3e3ba3
--- /dev/null
+++ b/tests/cts/net/ipsec/src/android/net/ipsec/ike/cts/IkeSessionParamsTestBase.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2020 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.ipsec.ike.cts;
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.LinkAddress;
+import android.net.Network;
+import android.net.TestNetworkInterface;
+import android.net.TestNetworkManager;
+import android.net.ipsec.ike.cts.TestNetworkUtils.TestNetworkCallback;
+import android.os.Binder;
+import android.os.IBinder;
+import android.os.ParcelFileDescriptor;
+import android.platform.test.annotations.AppModeFull;
+
+import androidx.test.InstrumentationRegistry;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+@AppModeFull(reason = "MANAGE_TEST_NETWORKS permission can't be granted to instant apps")
+abstract class IkeSessionParamsTestBase extends IkeTestBase {
+    // Static state to reduce setup/teardown
+    static ConnectivityManager sCM;
+    static TestNetworkManager sTNM;
+    static ParcelFileDescriptor sTunFd;
+    static TestNetworkCallback sTunNetworkCallback;
+    static Network sTunNetwork;
+
+    static Context sContext = InstrumentationRegistry.getContext();
+    static IBinder sBinder = new Binder();
+
+    // This method is guaranteed to run in subclasses and will run before subclasses' @BeforeClass
+    // methods.
+    @BeforeClass
+    public static void setUpTestNetworkBeforeClass() throws Exception {
+        InstrumentationRegistry.getInstrumentation()
+                .getUiAutomation()
+                .adoptShellPermissionIdentity();
+        sCM = (ConnectivityManager) sContext.getSystemService(Context.CONNECTIVITY_SERVICE);
+        sTNM = (TestNetworkManager) sContext.getSystemService(Context.TEST_NETWORK_SERVICE);
+
+        TestNetworkInterface testIface =
+                sTNM.createTunInterface(
+                        new LinkAddress[] {new LinkAddress(IPV4_ADDRESS_LOCAL, IP4_PREFIX_LEN)});
+
+        sTunFd = testIface.getFileDescriptor();
+        sTunNetworkCallback =
+                TestNetworkUtils.setupAndGetTestNetwork(
+                        sCM, sTNM, testIface.getInterfaceName(), sBinder);
+        sTunNetwork = sTunNetworkCallback.getNetworkBlocking();
+    }
+
+    // This method is guaranteed to run in subclasses and will run after subclasses' @AfterClass
+    // methods.
+    @AfterClass
+    public static void tearDownTestNetworkAfterClass() throws Exception {
+        sCM.unregisterNetworkCallback(sTunNetworkCallback);
+
+        sTNM.teardownTestNetwork(sTunNetwork);
+        sTunFd.close();
+
+        InstrumentationRegistry.getInstrumentation()
+                .getUiAutomation()
+                .dropShellPermissionIdentity();
+    }
+}