resolve merge conflicts of 836402e0e842584d47dddec49f9cb1f7d18fc833 to master

Bug: None
Test: I solemnly swear I tested this conflict resolution.
Change-Id: Ia76e345ddda5972b2c00731cd1d73a2c1d41c1db
diff --git a/Android.bp b/Android.bp
index 5e03982..4886490 100644
--- a/Android.bp
+++ b/Android.bp
@@ -225,6 +225,7 @@
         "core/java/android/net/INetworkScoreService.aidl",
         "core/java/android/net/INetworkStatsService.aidl",
         "core/java/android/net/INetworkStatsSession.aidl",
+        "core/java/android/net/ITestNetworkManager.aidl",
         "core/java/android/net/ITetheringEventCallback.aidl",
         "core/java/android/net/ITetheringStatsProvider.aidl",
         "core/java/android/net/nsd/INsdManager.aidl",
diff --git a/api/test-current.txt b/api/test-current.txt
index 4d1d440..c0668d5 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -1233,6 +1233,21 @@
     field @NonNull public static final android.os.Parcelable.Creator<android.net.StaticIpConfiguration> CREATOR;
   }
 
+  public final class TestNetworkInterface implements android.os.Parcelable {
+    ctor public TestNetworkInterface(android.os.ParcelFileDescriptor, String);
+    method public int describeContents();
+    method public android.os.ParcelFileDescriptor getFileDescriptor();
+    method public String getInterfaceName();
+    method public void writeToParcel(android.os.Parcel, int);
+    field public static final android.os.Parcelable.Creator<android.net.TestNetworkInterface> CREATOR;
+  }
+
+  public class TestNetworkManager {
+    method public android.net.TestNetworkInterface createTunInterface(@NonNull android.net.LinkAddress[]);
+    method public void setupTestNetwork(@NonNull String, @NonNull android.os.IBinder);
+    method public void teardownTestNetwork(@NonNull android.net.Network);
+  }
+
   public class TrafficStats {
     method public static long getLoopbackRxBytes();
     method public static long getLoopbackRxPackets();
diff --git a/core/java/android/net/ITestNetworkManager.aidl b/core/java/android/net/ITestNetworkManager.aidl
new file mode 100644
index 0000000..119a30c
--- /dev/null
+++ b/core/java/android/net/ITestNetworkManager.aidl
@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2018, 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;
+
+import android.net.LinkAddress;
+import android.net.TestNetworkInterface;
+import android.os.IBinder;
+import android.os.ParcelFileDescriptor;
+
+/**
+ * Interface that allows for creation and management of test-only networks.
+ *
+ * @hide
+ */
+interface ITestNetworkManager
+{
+    TestNetworkInterface createTunInterface(in LinkAddress[] linkAddrs);
+
+    void setupTestNetwork(in String iface, in IBinder binder);
+
+    void teardownTestNetwork(int netId);
+}
diff --git a/core/java/android/net/TestNetworkInterface.aidl b/core/java/android/net/TestNetworkInterface.aidl
new file mode 100644
index 0000000..e1f4f9f
--- /dev/null
+++ b/core/java/android/net/TestNetworkInterface.aidl
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2019 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;
+
+/** @hide */
+parcelable TestNetworkInterface;
diff --git a/core/java/android/net/TestNetworkInterface.java b/core/java/android/net/TestNetworkInterface.java
new file mode 100644
index 0000000..30e68f5
--- /dev/null
+++ b/core/java/android/net/TestNetworkInterface.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2019 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;
+
+import android.annotation.TestApi;
+import android.os.Parcel;
+import android.os.ParcelFileDescriptor;
+import android.os.Parcelable;
+
+/**
+ * This class is used to return the interface name and fd of the test interface
+ *
+ * @hide
+ */
+@TestApi
+public final class TestNetworkInterface implements Parcelable {
+    private static final String TAG = "TestNetworkInterface";
+
+    private final ParcelFileDescriptor mFileDescriptor;
+    private final String mInterfaceName;
+
+    @Override
+    public int describeContents() {
+        return (mFileDescriptor != null) ? Parcelable.CONTENTS_FILE_DESCRIPTOR : 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeParcelable(mFileDescriptor, PARCELABLE_WRITE_RETURN_VALUE);
+        out.writeString(mInterfaceName);
+    }
+
+    public TestNetworkInterface(ParcelFileDescriptor pfd, String intf) {
+        mFileDescriptor = pfd;
+        mInterfaceName = intf;
+    }
+
+    private TestNetworkInterface(Parcel in) {
+        mFileDescriptor = in.readParcelable(ParcelFileDescriptor.class.getClassLoader());
+        mInterfaceName = in.readString();
+    }
+
+    public ParcelFileDescriptor getFileDescriptor() {
+        return mFileDescriptor;
+    }
+
+    public String getInterfaceName() {
+        return mInterfaceName;
+    }
+
+    public static final Parcelable.Creator<TestNetworkInterface> CREATOR =
+            new Parcelable.Creator<TestNetworkInterface>() {
+                public TestNetworkInterface createFromParcel(Parcel in) {
+                    return new TestNetworkInterface(in);
+                }
+
+                public TestNetworkInterface[] newArray(int size) {
+                    return new TestNetworkInterface[size];
+                }
+            };
+}
diff --git a/core/java/android/net/TestNetworkManager.java b/core/java/android/net/TestNetworkManager.java
new file mode 100644
index 0000000..cd58e66
--- /dev/null
+++ b/core/java/android/net/TestNetworkManager.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2018 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;
+
+import android.annotation.NonNull;
+import android.annotation.TestApi;
+import android.content.Context;
+import android.os.IBinder;
+import android.os.RemoteException;
+
+import com.android.internal.util.Preconditions;
+
+/**
+ * Class that allows creation and management of per-app, test-only networks
+ *
+ * @hide
+ */
+@TestApi
+public class TestNetworkManager {
+    @NonNull private static final String TAG = TestNetworkManager.class.getSimpleName();
+
+    @NonNull private final ITestNetworkManager mService;
+    @NonNull private final Context mContext;
+
+    /** @hide */
+    public TestNetworkManager(@NonNull Context context, @NonNull ITestNetworkManager service) {
+        mContext = Preconditions.checkNotNull(context, "missing Context");
+        mService = Preconditions.checkNotNull(service, "missing ITestNetworkManager");
+    }
+
+    /**
+     * Teardown the capability-limited, testing-only network for a given interface
+     *
+     * @param network The test network that should be torn down
+     * @hide
+     */
+    @TestApi
+    public void teardownTestNetwork(@NonNull Network network) {
+        try {
+            mService.teardownTestNetwork(network.netId);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Sets up a capability-limited, testing-only network for a given interface
+     *
+     * @param iface the name of the interface to be used for the Network LinkProperties.
+     * @param binder A binder object guarding the lifecycle of this test network.
+     * @hide
+     */
+    @TestApi
+    public void setupTestNetwork(@NonNull String iface, @NonNull IBinder binder) {
+        try {
+            mService.setupTestNetwork(iface, binder);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Create a tun interface for testing purposes
+     *
+     * @param linkAddrs an array of LinkAddresses to assign to the TUN interface
+     * @return A ParcelFileDescriptor of the underlying TUN interface. Close this to tear down the
+     *     TUN interface.
+     * @hide
+     */
+    @TestApi
+    public TestNetworkInterface createTunInterface(@NonNull LinkAddress[] linkAddrs) {
+        try {
+            return mService.createTunInterface(linkAddrs);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+}
diff --git a/services/core/java/com/android/server/TestNetworkService.java b/services/core/java/com/android/server/TestNetworkService.java
new file mode 100644
index 0000000..e64ab78
--- /dev/null
+++ b/services/core/java/com/android/server/TestNetworkService.java
@@ -0,0 +1,338 @@
+/*
+ * Copyright (C) 2018 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.server;
+
+import static com.android.internal.util.Preconditions.checkNotNull;
+
+import android.annotation.NonNull;
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.INetd;
+import android.net.ITestNetworkManager;
+import android.net.IpPrefix;
+import android.net.LinkAddress;
+import android.net.LinkProperties;
+import android.net.NetworkAgent;
+import android.net.NetworkCapabilities;
+import android.net.NetworkInfo;
+import android.net.NetworkInfo.DetailedState;
+import android.net.RouteInfo;
+import android.net.StringNetworkSpecifier;
+import android.net.TestNetworkInterface;
+import android.net.util.NetdService;
+import android.os.Binder;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.IBinder;
+import android.os.INetworkManagementService;
+import android.os.Looper;
+import android.os.ParcelFileDescriptor;
+import android.os.RemoteException;
+import android.util.SparseArray;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.UncheckedIOException;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InterfaceAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/** @hide */
+class TestNetworkService extends ITestNetworkManager.Stub {
+    @NonNull private static final String TAG = TestNetworkService.class.getSimpleName();
+    @NonNull private static final String TEST_NETWORK_TYPE = "TEST_NETWORK";
+    @NonNull private static final String TEST_TUN_PREFIX = "testtun";
+    @NonNull private static final AtomicInteger sTestTunIndex = new AtomicInteger();
+
+    @NonNull private final Context mContext;
+    @NonNull private final INetworkManagementService mNMS;
+    @NonNull private final INetd mNetd;
+
+    @NonNull private final HandlerThread mHandlerThread;
+    @NonNull private final Handler mHandler;
+
+    // Native method stubs
+    private static native int jniCreateTun(@NonNull String iface);
+
+    @VisibleForTesting
+    protected TestNetworkService(
+            @NonNull Context context, @NonNull INetworkManagementService netManager) {
+        mHandlerThread = new HandlerThread("TestNetworkServiceThread");
+        mHandlerThread.start();
+        mHandler = new Handler(mHandlerThread.getLooper());
+
+        mContext = checkNotNull(context, "missing Context");
+        mNMS = checkNotNull(netManager, "missing INetworkManagementService");
+        mNetd = checkNotNull(NetdService.getInstance(), "could not get netd instance");
+    }
+
+    /**
+     * Create a TUN interface with the given interface name and link addresses
+     *
+     * <p>This method will return the FileDescriptor to the TUN interface. Close it to tear down the
+     * TUN interface.
+     */
+    @Override
+    public TestNetworkInterface createTunInterface(@NonNull LinkAddress[] linkAddrs) {
+        enforceTestNetworkPermissions(mContext);
+
+        checkNotNull(linkAddrs, "missing linkAddrs");
+
+        String iface = TEST_TUN_PREFIX + sTestTunIndex.getAndIncrement();
+        return Binder.withCleanCallingIdentity(
+                () -> {
+                    try {
+                        ParcelFileDescriptor tunIntf =
+                                ParcelFileDescriptor.adoptFd(jniCreateTun(iface));
+                        for (LinkAddress addr : linkAddrs) {
+                            mNetd.interfaceAddAddress(
+                                    iface,
+                                    addr.getAddress().getHostAddress(),
+                                    addr.getPrefixLength());
+                        }
+
+                        return new TestNetworkInterface(tunIntf, iface);
+                    } catch (RemoteException e) {
+                        throw e.rethrowFromSystemServer();
+                    }
+                });
+    }
+
+    // Tracker for TestNetworkAgents
+    @GuardedBy("mTestNetworkTracker")
+    @NonNull
+    private final SparseArray<TestNetworkAgent> mTestNetworkTracker = new SparseArray<>();
+
+    public class TestNetworkAgent extends NetworkAgent implements IBinder.DeathRecipient {
+        private static final int NETWORK_SCORE = 1; // Use a low, non-zero score.
+
+        private final int mUid;
+        @NonNull private final NetworkInfo mNi;
+        @NonNull private final NetworkCapabilities mNc;
+        @NonNull private final LinkProperties mLp;
+
+        @GuardedBy("mBinderLock")
+        @NonNull
+        private IBinder mBinder;
+
+        @NonNull private final Object mBinderLock = new Object();
+
+        private TestNetworkAgent(
+                @NonNull Looper looper,
+                @NonNull Context context,
+                @NonNull NetworkInfo ni,
+                @NonNull NetworkCapabilities nc,
+                @NonNull LinkProperties lp,
+                int uid,
+                @NonNull IBinder binder)
+                throws RemoteException {
+            super(looper, context, TEST_NETWORK_TYPE, ni, nc, lp, NETWORK_SCORE);
+
+            mUid = uid;
+            mNi = ni;
+            mNc = nc;
+            mLp = lp;
+
+            synchronized (mBinderLock) {
+                mBinder = binder; // Binder null-checks in create()
+
+                try {
+                    mBinder.linkToDeath(this, 0);
+                } catch (RemoteException e) {
+                    binderDied();
+                    throw e; // Abort, signal failure up the stack.
+                }
+            }
+        }
+
+        /**
+         * If the Binder object dies, this function is called to free the resources of this
+         * TestNetworkAgent
+         */
+        @Override
+        public void binderDied() {
+            teardown();
+        }
+
+        @Override
+        protected void unwanted() {
+            teardown();
+        }
+
+        private void teardown() {
+            mNi.setDetailedState(DetailedState.DISCONNECTED, null, null);
+            mNi.setIsAvailable(false);
+            sendNetworkInfo(mNi);
+
+            // Synchronize on mBinderLock to ensure that unlinkToDeath is never called more than
+            // once (otherwise it could throw an exception)
+            synchronized (mBinderLock) {
+                // If mBinder is null, this Test Network has already been cleaned up.
+                if (mBinder == null) return;
+                mBinder.unlinkToDeath(this, 0);
+                mBinder = null;
+            }
+
+            // Has to be in TestNetworkAgent to ensure all teardown codepaths properly clean up
+            // resources, even for binder death or unwanted calls.
+            synchronized (mTestNetworkTracker) {
+                mTestNetworkTracker.remove(netId);
+            }
+        }
+    }
+
+    private TestNetworkAgent registerTestNetworkAgent(
+            @NonNull Looper looper,
+            @NonNull Context context,
+            @NonNull String iface,
+            int callingUid,
+            @NonNull IBinder binder)
+            throws RemoteException, SocketException {
+        checkNotNull(looper, "missing Looper");
+        checkNotNull(context, "missing Context");
+        // iface and binder validity checked by caller
+
+        // Build network info with special testing type
+        NetworkInfo ni = new NetworkInfo(ConnectivityManager.TYPE_TEST, 0, TEST_NETWORK_TYPE, "");
+        ni.setDetailedState(DetailedState.CONNECTED, null, null);
+        ni.setIsAvailable(true);
+
+        // Build narrow set of NetworkCapabilities, useful only for testing
+        NetworkCapabilities nc = new NetworkCapabilities();
+        nc.clearAll(); // Remove default capabilities.
+        nc.addTransportType(NetworkCapabilities.TRANSPORT_TEST);
+        nc.addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED);
+        nc.addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED);
+        nc.setNetworkSpecifier(new StringNetworkSpecifier(iface));
+
+        // Build LinkProperties
+        LinkProperties lp = new LinkProperties();
+        lp.setInterfaceName(iface);
+
+        // Find the currently assigned addresses, and add them to LinkProperties
+        boolean allowIPv4 = false, allowIPv6 = false;
+        NetworkInterface netIntf = NetworkInterface.getByName(iface);
+        checkNotNull(netIntf, "No such network interface found: " + netIntf);
+
+        for (InterfaceAddress intfAddr : netIntf.getInterfaceAddresses()) {
+            lp.addLinkAddress(
+                    new LinkAddress(intfAddr.getAddress(), intfAddr.getNetworkPrefixLength()));
+
+            if (intfAddr.getAddress() instanceof Inet6Address) {
+                allowIPv6 |= !intfAddr.getAddress().isLinkLocalAddress();
+            } else if (intfAddr.getAddress() instanceof Inet4Address) {
+                allowIPv4 = true;
+            }
+        }
+
+        // Add global routes (but as non-default, non-internet providing network)
+        if (allowIPv4) {
+            lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null, iface));
+        }
+        if (allowIPv6) {
+            lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null, iface));
+        }
+
+        return new TestNetworkAgent(looper, context, ni, nc, lp, callingUid, binder);
+    }
+
+    /**
+     * Sets up a Network with extremely limited privileges, guarded by the MANAGE_TEST_NETWORKS
+     * permission.
+     *
+     * <p>This method provides a Network that is useful only for testing.
+     */
+    @Override
+    public void setupTestNetwork(@NonNull String iface, @NonNull IBinder binder) {
+        enforceTestNetworkPermissions(mContext);
+
+        checkNotNull(iface, "missing Iface");
+        checkNotNull(binder, "missing IBinder");
+
+        if (!(iface.startsWith(INetd.IPSEC_INTERFACE_PREFIX)
+                || iface.startsWith(TEST_TUN_PREFIX))) {
+            throw new IllegalArgumentException(
+                    "Cannot create network for non ipsec, non-testtun interface");
+        }
+
+        // Setup needs to be done with NETWORK_STACK privileges.
+        int callingUid = Binder.getCallingUid();
+        Binder.withCleanCallingIdentity(
+                () -> {
+                    try {
+                        mNMS.setInterfaceUp(iface);
+
+                        // Synchronize all accesses to mTestNetworkTracker to prevent the case
+                        // where:
+                        // 1. TestNetworkAgent successfully binds to death of binder
+                        // 2. Before it is added to the mTestNetworkTracker, binder dies,
+                        // binderDied() is called (on a different thread)
+                        // 3. This thread is pre-empted, put() is called after remove()
+                        synchronized (mTestNetworkTracker) {
+                            TestNetworkAgent agent =
+                                    registerTestNetworkAgent(
+                                            mHandler.getLooper(),
+                                            mContext,
+                                            iface,
+                                            callingUid,
+                                            binder);
+
+                            mTestNetworkTracker.put(agent.netId, agent);
+                        }
+                    } catch (SocketException e) {
+                        throw new UncheckedIOException(e);
+                    } catch (RemoteException e) {
+                        throw e.rethrowFromSystemServer();
+                    }
+                });
+    }
+
+    /** Teardown a test network */
+    @Override
+    public void teardownTestNetwork(int netId) {
+        enforceTestNetworkPermissions(mContext);
+
+        TestNetworkAgent agent;
+        synchronized (mTestNetworkTracker) {
+            agent = mTestNetworkTracker.get(netId);
+        }
+
+        if (agent == null) {
+            return; // Already torn down
+        } else if (agent.mUid != Binder.getCallingUid()) {
+            throw new SecurityException("Attempted to modify other user's test networks");
+        }
+
+        // Safe to be called multiple times.
+        agent.teardown();
+    }
+
+    // STOPSHIP: Change this back to android.Manifest.permission.MANAGE_TEST_NETWORKS
+    private static final String PERMISSION_NAME = "dummy";
+
+    public static void enforceTestNetworkPermissions(@NonNull Context context) {
+        // STOPSHIP: Re-enable these checks. Disabled until adoptShellPermissionIdentity() can be
+        //           called from CTS test code.
+        if (false) {
+            context.enforceCallingOrSelfPermission(PERMISSION_NAME, "TestNetworkService");
+        }
+    }
+}
diff --git a/services/core/jni/Android.bp b/services/core/jni/Android.bp
index 5c7b287..050a079 100644
--- a/services/core/jni/Android.bp
+++ b/services/core/jni/Android.bp
@@ -38,6 +38,7 @@
         "com_android_server_SerialService.cpp",
         "com_android_server_storage_AppFuseBridge.cpp",
         "com_android_server_SystemServer.cpp",
+        "com_android_server_TestNetworkService.cpp",
         "com_android_server_tv_TvUinputBridge.cpp",
         "com_android_server_tv_TvInputHal.cpp",
         "com_android_server_vr_VrManagerService.cpp",
diff --git a/services/core/jni/com_android_server_TestNetworkService.cpp b/services/core/jni/com_android_server_TestNetworkService.cpp
new file mode 100644
index 0000000..b90ff23
--- /dev/null
+++ b/services/core/jni/com_android_server_TestNetworkService.cpp
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define LOG_NDEBUG 0
+
+#define LOG_TAG "TestNetworkServiceJni"
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
+#include <linux/ipv6_route.h>
+#include <linux/route.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <log/log.h>
+
+#include "netutils/ifc.h"
+
+#include "jni.h"
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <nativehelper/JNIHelp.h>
+#include <nativehelper/ScopedUtfChars.h>
+
+namespace android {
+
+//------------------------------------------------------------------------------
+
+static void throwException(JNIEnv* env, int error, const char* action, const char* iface) {
+    const std::string& msg =
+        android::base::StringPrintf("Error %s %s: %s", action, iface, strerror(error));
+
+    jniThrowException(env, "java/lang/IllegalStateException", msg.c_str());
+}
+
+static int createTunInterface(JNIEnv* env, const char* iface) {
+    base::unique_fd tun(open("/dev/tun", O_RDWR | O_NONBLOCK));
+    ifreq ifr{};
+
+    // Allocate interface.
+    ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
+    strlcpy(ifr.ifr_name, iface, IFNAMSIZ);
+    if (ioctl(tun.get(), TUNSETIFF, &ifr)) {
+        throwException(env, errno, "allocating", ifr.ifr_name);
+        return -1;
+    }
+
+    // Activate interface using an unconnected datagram socket.
+    base::unique_fd inet6CtrlSock(socket(AF_INET6, SOCK_DGRAM, 0));
+    ifr.ifr_flags = IFF_UP;
+
+    if (ioctl(inet6CtrlSock.get(), SIOCSIFFLAGS, &ifr)) {
+        throwException(env, errno, "activating", ifr.ifr_name);
+        return -1;
+    }
+
+    return tun.release();
+}
+
+//------------------------------------------------------------------------------
+
+static jint create(JNIEnv* env, jobject /* thiz */, jstring jIface) {
+    ScopedUtfChars iface(env, jIface);
+    if (!iface.c_str()) {
+        jniThrowNullPointerException(env, "iface");
+        return -1;
+    }
+
+    int tun = createTunInterface(env, iface.c_str());
+
+    // Any exceptions will be thrown from the createTunInterface call
+    return tun;
+}
+
+//------------------------------------------------------------------------------
+
+static const JNINativeMethod gMethods[] = {
+    {"jniCreateTun", "(Ljava/lang/String;)I", (void*)create},
+};
+
+int register_android_server_TestNetworkService(JNIEnv* env) {
+    return jniRegisterNativeMethods(env, "com/android/server/TestNetworkService", gMethods,
+                                    NELEM(gMethods));
+}
+
+}; // namespace android
diff --git a/services/core/jni/onload.cpp b/services/core/jni/onload.cpp
index 6e31aed..5ffed03 100644
--- a/services/core/jni/onload.cpp
+++ b/services/core/jni/onload.cpp
@@ -41,6 +41,7 @@
 int register_android_server_location_GnssLocationProvider(JNIEnv* env);
 int register_android_server_connectivity_Vpn(JNIEnv* env);
 int register_android_server_connectivity_tethering_OffloadHardwareInterface(JNIEnv*);
+int register_android_server_TestNetworkService(JNIEnv* env);
 int register_android_server_devicepolicy_CryptoTestHelper(JNIEnv*);
 int register_android_server_hdmi_HdmiCecController(JNIEnv* env);
 int register_android_server_tv_TvUinputBridge(JNIEnv* env);
@@ -85,6 +86,7 @@
     register_android_server_location_GnssLocationProvider(env);
     register_android_server_connectivity_Vpn(env);
     register_android_server_connectivity_tethering_OffloadHardwareInterface(env);
+    register_android_server_TestNetworkService(env);
     register_android_server_devicepolicy_CryptoTestHelper(env);
     register_android_server_ConsumerIrService(env);
     register_android_server_BatteryStatsService(env);