Centralize nsd associated files

Move all nsd associated files include framework, service and test
to package/Nsd first. After clear all hidden API dependencies, we
can easily migrate these files into connectivity mainline module.

Bug: 206893064
Test: atest FrameworksNetTests CtsNetTestCases
Change-Id: Id26f471a10fe7882e31ccc2dbb73219461f00dbd
diff --git a/packages/Nsd/framework/Android.bp b/packages/Nsd/framework/Android.bp
new file mode 100644
index 0000000..2363a9f
--- /dev/null
+++ b/packages/Nsd/framework/Android.bp
@@ -0,0 +1,54 @@
+//
+// 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 {
+    // See: http://go/android-license-faq
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+filegroup {
+    name: "framework-connectivity-nsd-internal-sources",
+    srcs: [
+        "src/**/*.java",
+        "src/**/*.aidl",
+    ],
+    path: "src",
+    visibility: [
+        "//visibility:private",
+    ],
+}
+
+filegroup {
+    name: "framework-connectivity-nsd-aidl-export-sources",
+    srcs: [
+        "aidl-export/**/*.aidl",
+    ],
+    path: "aidl-export",
+    visibility: [
+        "//visibility:private",
+    ],
+}
+
+filegroup {
+    name: "framework-connectivity-nsd-sources",
+    srcs: [
+        ":framework-connectivity-nsd-internal-sources",
+        ":framework-connectivity-nsd-aidl-export-sources",
+    ],
+    visibility: [
+        "//frameworks/base",
+    ],
+}
diff --git a/packages/Nsd/framework/aidl-export/android/net/nsd/NsdServiceInfo.aidl b/packages/Nsd/framework/aidl-export/android/net/nsd/NsdServiceInfo.aidl
new file mode 100644
index 0000000..657bdd1
--- /dev/null
+++ b/packages/Nsd/framework/aidl-export/android/net/nsd/NsdServiceInfo.aidl
@@ -0,0 +1,19 @@
+/*
+ * 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 android.net.nsd;
+
+@JavaOnlyStableParcelable parcelable NsdServiceInfo;
\ No newline at end of file
diff --git a/packages/Nsd/framework/src/android/net/nsd/INsdManager.aidl b/packages/Nsd/framework/src/android/net/nsd/INsdManager.aidl
new file mode 100644
index 0000000..89e9cdb
--- /dev/null
+++ b/packages/Nsd/framework/src/android/net/nsd/INsdManager.aidl
@@ -0,0 +1,30 @@
+/**
+ * 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 android.net.nsd;
+
+import android.net.nsd.INsdManagerCallback;
+import android.net.nsd.INsdServiceConnector;
+import android.os.Messenger;
+
+/**
+ * Interface that NsdService implements to connect NsdManager clients.
+ *
+ * {@hide}
+ */
+interface INsdManager {
+    INsdServiceConnector connect(INsdManagerCallback cb);
+}
diff --git a/packages/Nsd/framework/src/android/net/nsd/INsdManagerCallback.aidl b/packages/Nsd/framework/src/android/net/nsd/INsdManagerCallback.aidl
new file mode 100644
index 0000000..1a262ec
--- /dev/null
+++ b/packages/Nsd/framework/src/android/net/nsd/INsdManagerCallback.aidl
@@ -0,0 +1,39 @@
+/**
+ * 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 android.net.nsd;
+
+import android.os.Messenger;
+import android.net.nsd.NsdServiceInfo;
+
+/**
+ * Callbacks from NsdService to NsdManager
+ * @hide
+ */
+oneway interface INsdManagerCallback {
+    void onDiscoverServicesStarted(int listenerKey, in NsdServiceInfo info);
+    void onDiscoverServicesFailed(int listenerKey, int error);
+    void onServiceFound(int listenerKey, in NsdServiceInfo info);
+    void onServiceLost(int listenerKey, in NsdServiceInfo info);
+    void onStopDiscoveryFailed(int listenerKey, int error);
+    void onStopDiscoverySucceeded(int listenerKey);
+    void onRegisterServiceFailed(int listenerKey, int error);
+    void onRegisterServiceSucceeded(int listenerKey, in NsdServiceInfo info);
+    void onUnregisterServiceFailed(int listenerKey, int error);
+    void onUnregisterServiceSucceeded(int listenerKey);
+    void onResolveServiceFailed(int listenerKey, int error);
+    void onResolveServiceSucceeded(int listenerKey, in NsdServiceInfo info);
+}
diff --git a/packages/Nsd/framework/src/android/net/nsd/INsdServiceConnector.aidl b/packages/Nsd/framework/src/android/net/nsd/INsdServiceConnector.aidl
new file mode 100644
index 0000000..b06ae55
--- /dev/null
+++ b/packages/Nsd/framework/src/android/net/nsd/INsdServiceConnector.aidl
@@ -0,0 +1,35 @@
+/**
+ * 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 android.net.nsd;
+
+import android.net.nsd.INsdManagerCallback;
+import android.net.nsd.NsdServiceInfo;
+import android.os.Messenger;
+
+/**
+ * Interface that NsdService implements for each NsdManager client.
+ *
+ * {@hide}
+ */
+interface INsdServiceConnector {
+    void registerService(int listenerKey, in NsdServiceInfo serviceInfo);
+    void unregisterService(int listenerKey);
+    void discoverServices(int listenerKey, in NsdServiceInfo serviceInfo);
+    void stopDiscovery(int listenerKey);
+    void resolveService(int listenerKey, in NsdServiceInfo serviceInfo);
+    void startDaemon();
+}
\ No newline at end of file
diff --git a/packages/Nsd/framework/src/android/net/nsd/NsdManager.java b/packages/Nsd/framework/src/android/net/nsd/NsdManager.java
new file mode 100644
index 0000000..6c597e2
--- /dev/null
+++ b/packages/Nsd/framework/src/android/net/nsd/NsdManager.java
@@ -0,0 +1,734 @@
+/*
+ * 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 android.net.nsd;
+
+import static com.android.internal.util.Preconditions.checkArgument;
+import static com.android.internal.util.Preconditions.checkNotNull;
+import static com.android.internal.util.Preconditions.checkStringNotEmpty;
+
+import android.annotation.SdkConstant;
+import android.annotation.SdkConstant.SdkConstantType;
+import android.annotation.SystemService;
+import android.app.compat.CompatChanges;
+import android.compat.annotation.ChangeId;
+import android.compat.annotation.EnabledSince;
+import android.content.Context;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Looper;
+import android.os.Message;
+import android.os.RemoteException;
+import android.util.Log;
+import android.util.SparseArray;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.Protocol;
+
+/**
+ * The Network Service Discovery Manager class provides the API to discover services
+ * on a network. As an example, if device A and device B are connected over a Wi-Fi
+ * network, a game registered on device A can be discovered by a game on device
+ * B. Another example use case is an application discovering printers on the network.
+ *
+ * <p> The API currently supports DNS based service discovery and discovery is currently
+ * limited to a local network over Multicast DNS. DNS service discovery is described at
+ * http://files.dns-sd.org/draft-cheshire-dnsext-dns-sd.txt
+ *
+ * <p> The API is asynchronous, and responses to requests from an application are on listener
+ * callbacks on a separate internal thread.
+ *
+ * <p> There are three main operations the API supports - registration, discovery and resolution.
+ * <pre>
+ *                          Application start
+ *                                 |
+ *                                 |
+ *                                 |                  onServiceRegistered()
+ *                     Register any local services  /
+ *                      to be advertised with       \
+ *                       registerService()            onRegistrationFailed()
+ *                                 |
+ *                                 |
+ *                          discoverServices()
+ *                                 |
+ *                      Maintain a list to track
+ *                        discovered services
+ *                                 |
+ *                                 |--------->
+ *                                 |          |
+ *                                 |      onServiceFound()
+ *                                 |          |
+ *                                 |     add service to list
+ *                                 |          |
+ *                                 |<----------
+ *                                 |
+ *                                 |--------->
+ *                                 |          |
+ *                                 |      onServiceLost()
+ *                                 |          |
+ *                                 |   remove service from list
+ *                                 |          |
+ *                                 |<----------
+ *                                 |
+ *                                 |
+ *                                 | Connect to a service
+ *                                 | from list ?
+ *                                 |
+ *                          resolveService()
+ *                                 |
+ *                         onServiceResolved()
+ *                                 |
+ *                     Establish connection to service
+ *                     with the host and port information
+ *
+ * </pre>
+ * An application that needs to advertise itself over a network for other applications to
+ * discover it can do so with a call to {@link #registerService}. If Example is a http based
+ * application that can provide HTML data to peer services, it can register a name "Example"
+ * with service type "_http._tcp". A successful registration is notified with a callback to
+ * {@link RegistrationListener#onServiceRegistered} and a failure to register is notified
+ * over {@link RegistrationListener#onRegistrationFailed}
+ *
+ * <p> A peer application looking for http services can initiate a discovery for "_http._tcp"
+ * with a call to {@link #discoverServices}. A service found is notified with a callback
+ * to {@link DiscoveryListener#onServiceFound} and a service lost is notified on
+ * {@link DiscoveryListener#onServiceLost}.
+ *
+ * <p> Once the peer application discovers the "Example" http service, and either needs to read the
+ * attributes of the service or wants to receive data from the "Example" application, it can
+ * initiate a resolve with {@link #resolveService} to resolve the attributes, host, and port
+ * details. A successful resolve is notified on {@link ResolveListener#onServiceResolved} and a
+ * failure is notified on {@link ResolveListener#onResolveFailed}.
+ *
+ * Applications can reserve for a service type at
+ * http://www.iana.org/form/ports-service. Existing services can be found at
+ * http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml
+ *
+ * {@see NsdServiceInfo}
+ */
+@SystemService(Context.NSD_SERVICE)
+public final class NsdManager {
+    private static final String TAG = NsdManager.class.getSimpleName();
+    private static final boolean DBG = false;
+
+    /**
+     * When enabled, apps targeting < Android 12 are considered legacy for
+     * the NSD native daemon.
+     * The platform will only keep the daemon running as long as there are
+     * any legacy apps connected.
+     *
+     * After Android 12, directly communicate with native daemon might not
+     * work since the native damon won't always stay alive.
+     * Use the NSD APIs from NsdManager as the replacement is recommended.
+     * An another alternative could be bundling your own mdns solutions instead of
+     * depending on the system mdns native daemon.
+     *
+     * @hide
+     */
+    @ChangeId
+    @EnabledSince(targetSdkVersion = android.os.Build.VERSION_CODES.S)
+    public static final long RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS = 191844585L;
+
+    /**
+     * Broadcast intent action to indicate whether network service discovery is
+     * enabled or disabled. An extra {@link #EXTRA_NSD_STATE} provides the state
+     * information as int.
+     *
+     * @see #EXTRA_NSD_STATE
+     */
+    @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
+    public static final String ACTION_NSD_STATE_CHANGED = "android.net.nsd.STATE_CHANGED";
+
+    /**
+     * The lookup key for an int that indicates whether network service discovery is enabled
+     * or disabled. Retrieve it with {@link android.content.Intent#getIntExtra(String,int)}.
+     *
+     * @see #NSD_STATE_DISABLED
+     * @see #NSD_STATE_ENABLED
+     */
+    public static final String EXTRA_NSD_STATE = "nsd_state";
+
+    /**
+     * Network service discovery is disabled
+     *
+     * @see #ACTION_NSD_STATE_CHANGED
+     */
+    public static final int NSD_STATE_DISABLED = 1;
+
+    /**
+     * Network service discovery is enabled
+     *
+     * @see #ACTION_NSD_STATE_CHANGED
+     */
+    public static final int NSD_STATE_ENABLED = 2;
+
+    private static final int BASE = Protocol.BASE_NSD_MANAGER;
+
+    /** @hide */
+    public static final int DISCOVER_SERVICES                       = BASE + 1;
+    /** @hide */
+    public static final int DISCOVER_SERVICES_STARTED               = BASE + 2;
+    /** @hide */
+    public static final int DISCOVER_SERVICES_FAILED                = BASE + 3;
+    /** @hide */
+    public static final int SERVICE_FOUND                           = BASE + 4;
+    /** @hide */
+    public static final int SERVICE_LOST                            = BASE + 5;
+
+    /** @hide */
+    public static final int STOP_DISCOVERY                          = BASE + 6;
+    /** @hide */
+    public static final int STOP_DISCOVERY_FAILED                   = BASE + 7;
+    /** @hide */
+    public static final int STOP_DISCOVERY_SUCCEEDED                = BASE + 8;
+
+    /** @hide */
+    public static final int REGISTER_SERVICE                        = BASE + 9;
+    /** @hide */
+    public static final int REGISTER_SERVICE_FAILED                 = BASE + 10;
+    /** @hide */
+    public static final int REGISTER_SERVICE_SUCCEEDED              = BASE + 11;
+
+    /** @hide */
+    public static final int UNREGISTER_SERVICE                      = BASE + 12;
+    /** @hide */
+    public static final int UNREGISTER_SERVICE_FAILED               = BASE + 13;
+    /** @hide */
+    public static final int UNREGISTER_SERVICE_SUCCEEDED            = BASE + 14;
+
+    /** @hide */
+    public static final int RESOLVE_SERVICE                         = BASE + 18;
+    /** @hide */
+    public static final int RESOLVE_SERVICE_FAILED                  = BASE + 19;
+    /** @hide */
+    public static final int RESOLVE_SERVICE_SUCCEEDED               = BASE + 20;
+
+    /** @hide */
+    public static final int DAEMON_CLEANUP                          = BASE + 21;
+
+    /** @hide */
+    public static final int DAEMON_STARTUP                          = BASE + 22;
+
+    /** @hide */
+    public static final int ENABLE                                  = BASE + 24;
+    /** @hide */
+    public static final int DISABLE                                 = BASE + 25;
+
+    /** @hide */
+    public static final int NATIVE_DAEMON_EVENT                     = BASE + 26;
+
+    /** @hide */
+    public static final int REGISTER_CLIENT                         = BASE + 27;
+    /** @hide */
+    public static final int UNREGISTER_CLIENT                       = BASE + 28;
+
+    /** Dns based service discovery protocol */
+    public static final int PROTOCOL_DNS_SD = 0x0001;
+
+    private static final SparseArray<String> EVENT_NAMES = new SparseArray<>();
+    static {
+        EVENT_NAMES.put(DISCOVER_SERVICES, "DISCOVER_SERVICES");
+        EVENT_NAMES.put(DISCOVER_SERVICES_STARTED, "DISCOVER_SERVICES_STARTED");
+        EVENT_NAMES.put(DISCOVER_SERVICES_FAILED, "DISCOVER_SERVICES_FAILED");
+        EVENT_NAMES.put(SERVICE_FOUND, "SERVICE_FOUND");
+        EVENT_NAMES.put(SERVICE_LOST, "SERVICE_LOST");
+        EVENT_NAMES.put(STOP_DISCOVERY, "STOP_DISCOVERY");
+        EVENT_NAMES.put(STOP_DISCOVERY_FAILED, "STOP_DISCOVERY_FAILED");
+        EVENT_NAMES.put(STOP_DISCOVERY_SUCCEEDED, "STOP_DISCOVERY_SUCCEEDED");
+        EVENT_NAMES.put(REGISTER_SERVICE, "REGISTER_SERVICE");
+        EVENT_NAMES.put(REGISTER_SERVICE_FAILED, "REGISTER_SERVICE_FAILED");
+        EVENT_NAMES.put(REGISTER_SERVICE_SUCCEEDED, "REGISTER_SERVICE_SUCCEEDED");
+        EVENT_NAMES.put(UNREGISTER_SERVICE, "UNREGISTER_SERVICE");
+        EVENT_NAMES.put(UNREGISTER_SERVICE_FAILED, "UNREGISTER_SERVICE_FAILED");
+        EVENT_NAMES.put(UNREGISTER_SERVICE_SUCCEEDED, "UNREGISTER_SERVICE_SUCCEEDED");
+        EVENT_NAMES.put(RESOLVE_SERVICE, "RESOLVE_SERVICE");
+        EVENT_NAMES.put(RESOLVE_SERVICE_FAILED, "RESOLVE_SERVICE_FAILED");
+        EVENT_NAMES.put(RESOLVE_SERVICE_SUCCEEDED, "RESOLVE_SERVICE_SUCCEEDED");
+        EVENT_NAMES.put(DAEMON_CLEANUP, "DAEMON_CLEANUP");
+        EVENT_NAMES.put(DAEMON_STARTUP, "DAEMON_STARTUP");
+        EVENT_NAMES.put(ENABLE, "ENABLE");
+        EVENT_NAMES.put(DISABLE, "DISABLE");
+        EVENT_NAMES.put(NATIVE_DAEMON_EVENT, "NATIVE_DAEMON_EVENT");
+    }
+
+    /** @hide */
+    public static String nameOf(int event) {
+        String name = EVENT_NAMES.get(event);
+        if (name == null) {
+            return Integer.toString(event);
+        }
+        return name;
+    }
+
+    private static final int FIRST_LISTENER_KEY = 1;
+
+    private final INsdServiceConnector mService;
+    private final Context mContext;
+
+    private int mListenerKey = FIRST_LISTENER_KEY;
+    private final SparseArray mListenerMap = new SparseArray();
+    private final SparseArray<NsdServiceInfo> mServiceMap = new SparseArray<>();
+    private final Object mMapLock = new Object();
+
+    private final ServiceHandler mHandler;
+
+    /**
+     * Create a new Nsd instance. Applications use
+     * {@link android.content.Context#getSystemService Context.getSystemService()} to retrieve
+     * {@link android.content.Context#NSD_SERVICE Context.NSD_SERVICE}.
+     * @param service the Binder interface
+     * @hide - hide this because it takes in a parameter of type INsdManager, which
+     * is a system private class.
+     */
+    public NsdManager(Context context, INsdManager service) {
+        mContext = context;
+
+        HandlerThread t = new HandlerThread("NsdManager");
+        t.start();
+        mHandler = new ServiceHandler(t.getLooper());
+
+        try {
+            mService = service.connect(new NsdCallbackImpl(mHandler));
+        } catch (RemoteException e) {
+            throw new RuntimeException("Failed to connect to NsdService");
+        }
+
+        // Only proactively start the daemon if the target SDK < S, otherwise the internal service
+        // would automatically start/stop the native daemon as needed.
+        if (!CompatChanges.isChangeEnabled(RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)) {
+            try {
+                mService.startDaemon();
+            } catch (RemoteException e) {
+                Log.e(TAG, "Failed to proactively start daemon");
+                // Continue: the daemon can still be started on-demand later
+            }
+        }
+    }
+
+    private static class NsdCallbackImpl extends INsdManagerCallback.Stub {
+        private final Handler mServHandler;
+
+        NsdCallbackImpl(Handler serviceHandler) {
+            mServHandler = serviceHandler;
+        }
+
+        private void sendInfo(int message, int listenerKey, NsdServiceInfo info) {
+            mServHandler.sendMessage(mServHandler.obtainMessage(message, 0, listenerKey, info));
+        }
+
+        private void sendError(int message, int listenerKey, int error) {
+            mServHandler.sendMessage(mServHandler.obtainMessage(message, error, listenerKey));
+        }
+
+        private void sendNoArg(int message, int listenerKey) {
+            mServHandler.sendMessage(mServHandler.obtainMessage(message, 0, listenerKey));
+        }
+
+        @Override
+        public void onDiscoverServicesStarted(int listenerKey, NsdServiceInfo info) {
+            sendInfo(DISCOVER_SERVICES_STARTED, listenerKey, info);
+        }
+
+        @Override
+        public void onDiscoverServicesFailed(int listenerKey, int error) {
+            sendError(DISCOVER_SERVICES_FAILED, listenerKey, error);
+        }
+
+        @Override
+        public void onServiceFound(int listenerKey, NsdServiceInfo info) {
+            sendInfo(SERVICE_FOUND, listenerKey, info);
+        }
+
+        @Override
+        public void onServiceLost(int listenerKey, NsdServiceInfo info) {
+            sendInfo(SERVICE_LOST, listenerKey, info);
+        }
+
+        @Override
+        public void onStopDiscoveryFailed(int listenerKey, int error) {
+            sendError(STOP_DISCOVERY_FAILED, listenerKey, error);
+        }
+
+        @Override
+        public void onStopDiscoverySucceeded(int listenerKey) {
+            sendNoArg(STOP_DISCOVERY_SUCCEEDED, listenerKey);
+        }
+
+        @Override
+        public void onRegisterServiceFailed(int listenerKey, int error) {
+            sendError(REGISTER_SERVICE_FAILED, listenerKey, error);
+        }
+
+        @Override
+        public void onRegisterServiceSucceeded(int listenerKey, NsdServiceInfo info) {
+            sendInfo(REGISTER_SERVICE_SUCCEEDED, listenerKey, info);
+        }
+
+        @Override
+        public void onUnregisterServiceFailed(int listenerKey, int error) {
+            sendError(UNREGISTER_SERVICE_FAILED, listenerKey, error);
+        }
+
+        @Override
+        public void onUnregisterServiceSucceeded(int listenerKey) {
+            sendNoArg(UNREGISTER_SERVICE_SUCCEEDED, listenerKey);
+        }
+
+        @Override
+        public void onResolveServiceFailed(int listenerKey, int error) {
+            sendError(RESOLVE_SERVICE_FAILED, listenerKey, error);
+        }
+
+        @Override
+        public void onResolveServiceSucceeded(int listenerKey, NsdServiceInfo info) {
+            sendInfo(RESOLVE_SERVICE_SUCCEEDED, listenerKey, info);
+        }
+    }
+
+    /**
+     * Failures are passed with {@link RegistrationListener#onRegistrationFailed},
+     * {@link RegistrationListener#onUnregistrationFailed},
+     * {@link DiscoveryListener#onStartDiscoveryFailed},
+     * {@link DiscoveryListener#onStopDiscoveryFailed} or {@link ResolveListener#onResolveFailed}.
+     *
+     * Indicates that the operation failed due to an internal error.
+     */
+    public static final int FAILURE_INTERNAL_ERROR               = 0;
+
+    /**
+     * Indicates that the operation failed because it is already active.
+     */
+    public static final int FAILURE_ALREADY_ACTIVE              = 3;
+
+    /**
+     * Indicates that the operation failed because the maximum outstanding
+     * requests from the applications have reached.
+     */
+    public static final int FAILURE_MAX_LIMIT                   = 4;
+
+    /** Interface for callback invocation for service discovery */
+    public interface DiscoveryListener {
+
+        public void onStartDiscoveryFailed(String serviceType, int errorCode);
+
+        public void onStopDiscoveryFailed(String serviceType, int errorCode);
+
+        public void onDiscoveryStarted(String serviceType);
+
+        public void onDiscoveryStopped(String serviceType);
+
+        public void onServiceFound(NsdServiceInfo serviceInfo);
+
+        public void onServiceLost(NsdServiceInfo serviceInfo);
+    }
+
+    /** Interface for callback invocation for service registration */
+    public interface RegistrationListener {
+
+        public void onRegistrationFailed(NsdServiceInfo serviceInfo, int errorCode);
+
+        public void onUnregistrationFailed(NsdServiceInfo serviceInfo, int errorCode);
+
+        public void onServiceRegistered(NsdServiceInfo serviceInfo);
+
+        public void onServiceUnregistered(NsdServiceInfo serviceInfo);
+    }
+
+    /** Interface for callback invocation for service resolution */
+    public interface ResolveListener {
+
+        public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode);
+
+        public void onServiceResolved(NsdServiceInfo serviceInfo);
+    }
+
+    @VisibleForTesting
+    class ServiceHandler extends Handler {
+        ServiceHandler(Looper looper) {
+            super(looper);
+        }
+
+        @Override
+        public void handleMessage(Message message) {
+            final int what = message.what;
+            final int key = message.arg2;
+            final Object listener;
+            final NsdServiceInfo ns;
+            synchronized (mMapLock) {
+                listener = mListenerMap.get(key);
+                ns = mServiceMap.get(key);
+            }
+            if (listener == null) {
+                Log.d(TAG, "Stale key " + message.arg2);
+                return;
+            }
+            if (DBG) {
+                Log.d(TAG, "received " + nameOf(what) + " for key " + key + ", service " + ns);
+            }
+            switch (what) {
+                case DISCOVER_SERVICES_STARTED:
+                    String s = getNsdServiceInfoType((NsdServiceInfo) message.obj);
+                    ((DiscoveryListener) listener).onDiscoveryStarted(s);
+                    break;
+                case DISCOVER_SERVICES_FAILED:
+                    removeListener(key);
+                    ((DiscoveryListener) listener).onStartDiscoveryFailed(getNsdServiceInfoType(ns),
+                            message.arg1);
+                    break;
+                case SERVICE_FOUND:
+                    ((DiscoveryListener) listener).onServiceFound((NsdServiceInfo) message.obj);
+                    break;
+                case SERVICE_LOST:
+                    ((DiscoveryListener) listener).onServiceLost((NsdServiceInfo) message.obj);
+                    break;
+                case STOP_DISCOVERY_FAILED:
+                    // TODO: failure to stop discovery should be internal and retried internally, as
+                    // the effect for the client is indistinguishable from STOP_DISCOVERY_SUCCEEDED
+                    removeListener(key);
+                    ((DiscoveryListener) listener).onStopDiscoveryFailed(getNsdServiceInfoType(ns),
+                            message.arg1);
+                    break;
+                case STOP_DISCOVERY_SUCCEEDED:
+                    removeListener(key);
+                    ((DiscoveryListener) listener).onDiscoveryStopped(getNsdServiceInfoType(ns));
+                    break;
+                case REGISTER_SERVICE_FAILED:
+                    removeListener(key);
+                    ((RegistrationListener) listener).onRegistrationFailed(ns, message.arg1);
+                    break;
+                case REGISTER_SERVICE_SUCCEEDED:
+                    ((RegistrationListener) listener).onServiceRegistered(
+                            (NsdServiceInfo) message.obj);
+                    break;
+                case UNREGISTER_SERVICE_FAILED:
+                    removeListener(key);
+                    ((RegistrationListener) listener).onUnregistrationFailed(ns, message.arg1);
+                    break;
+                case UNREGISTER_SERVICE_SUCCEEDED:
+                    // TODO: do not unregister listener until service is unregistered, or provide
+                    // alternative way for unregistering ?
+                    removeListener(message.arg2);
+                    ((RegistrationListener) listener).onServiceUnregistered(ns);
+                    break;
+                case RESOLVE_SERVICE_FAILED:
+                    removeListener(key);
+                    ((ResolveListener) listener).onResolveFailed(ns, message.arg1);
+                    break;
+                case RESOLVE_SERVICE_SUCCEEDED:
+                    removeListener(key);
+                    ((ResolveListener) listener).onServiceResolved((NsdServiceInfo) message.obj);
+                    break;
+                default:
+                    Log.d(TAG, "Ignored " + message);
+                    break;
+            }
+        }
+    }
+
+    private int nextListenerKey() {
+        // Ensure mListenerKey >= FIRST_LISTENER_KEY;
+        mListenerKey = Math.max(FIRST_LISTENER_KEY, mListenerKey + 1);
+        return mListenerKey;
+    }
+
+    // Assert that the listener is not in the map, then add it and returns its key
+    private int putListener(Object listener, NsdServiceInfo s) {
+        checkListener(listener);
+        final int key;
+        synchronized (mMapLock) {
+            int valueIndex = mListenerMap.indexOfValue(listener);
+            checkArgument(valueIndex == -1, "listener already in use");
+            key = nextListenerKey();
+            mListenerMap.put(key, listener);
+            mServiceMap.put(key, s);
+        }
+        return key;
+    }
+
+    private void removeListener(int key) {
+        synchronized (mMapLock) {
+            mListenerMap.remove(key);
+            mServiceMap.remove(key);
+        }
+    }
+
+    private int getListenerKey(Object listener) {
+        checkListener(listener);
+        synchronized (mMapLock) {
+            int valueIndex = mListenerMap.indexOfValue(listener);
+            checkArgument(valueIndex != -1, "listener not registered");
+            return mListenerMap.keyAt(valueIndex);
+        }
+    }
+
+    private static String getNsdServiceInfoType(NsdServiceInfo s) {
+        if (s == null) return "?";
+        return s.getServiceType();
+    }
+
+    /**
+     * Register a service to be discovered by other services.
+     *
+     * <p> The function call immediately returns after sending a request to register service
+     * to the framework. The application is notified of a successful registration
+     * through the callback {@link RegistrationListener#onServiceRegistered} or a failure
+     * through {@link RegistrationListener#onRegistrationFailed}.
+     *
+     * <p> The application should call {@link #unregisterService} when the service
+     * registration is no longer required, and/or whenever the application is stopped.
+     *
+     * @param serviceInfo The service being registered
+     * @param protocolType The service discovery protocol
+     * @param listener The listener notifies of a successful registration and is used to
+     * unregister this service through a call on {@link #unregisterService}. Cannot be null.
+     * Cannot be in use for an active service registration.
+     */
+    public void registerService(NsdServiceInfo serviceInfo, int protocolType,
+            RegistrationListener listener) {
+        checkArgument(serviceInfo.getPort() > 0, "Invalid port number");
+        checkServiceInfo(serviceInfo);
+        checkProtocol(protocolType);
+        int key = putListener(listener, serviceInfo);
+        try {
+            mService.registerService(key, serviceInfo);
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Unregister a service registered through {@link #registerService}. A successful
+     * unregister is notified to the application with a call to
+     * {@link RegistrationListener#onServiceUnregistered}.
+     *
+     * @param listener This should be the listener object that was passed to
+     * {@link #registerService}. It identifies the service that should be unregistered
+     * and notifies of a successful or unsuccessful unregistration via the listener
+     * callbacks.  In API versions 20 and above, the listener object may be used for
+     * another service registration once the callback has been called.  In API versions <= 19,
+     * there is no entirely reliable way to know when a listener may be re-used, and a new
+     * listener should be created for each service registration request.
+     */
+    public void unregisterService(RegistrationListener listener) {
+        int id = getListenerKey(listener);
+        try {
+            mService.unregisterService(id);
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Initiate service discovery to browse for instances of a service type. Service discovery
+     * consumes network bandwidth and will continue until the application calls
+     * {@link #stopServiceDiscovery}.
+     *
+     * <p> The function call immediately returns after sending a request to start service
+     * discovery to the framework. The application is notified of a success to initiate
+     * discovery through the callback {@link DiscoveryListener#onDiscoveryStarted} or a failure
+     * through {@link DiscoveryListener#onStartDiscoveryFailed}.
+     *
+     * <p> Upon successful start, application is notified when a service is found with
+     * {@link DiscoveryListener#onServiceFound} or when a service is lost with
+     * {@link DiscoveryListener#onServiceLost}.
+     *
+     * <p> Upon failure to start, service discovery is not active and application does
+     * not need to invoke {@link #stopServiceDiscovery}
+     *
+     * <p> The application should call {@link #stopServiceDiscovery} when discovery of this
+     * service type is no longer required, and/or whenever the application is paused or
+     * stopped.
+     *
+     * @param serviceType The service type being discovered. Examples include "_http._tcp" for
+     * http services or "_ipp._tcp" for printers
+     * @param protocolType The service discovery protocol
+     * @param listener  The listener notifies of a successful discovery and is used
+     * to stop discovery on this serviceType through a call on {@link #stopServiceDiscovery}.
+     * Cannot be null. Cannot be in use for an active service discovery.
+     */
+    public void discoverServices(String serviceType, int protocolType, DiscoveryListener listener) {
+        checkStringNotEmpty(serviceType, "Service type cannot be empty");
+        checkProtocol(protocolType);
+
+        NsdServiceInfo s = new NsdServiceInfo();
+        s.setServiceType(serviceType);
+
+        int key = putListener(listener, s);
+        try {
+            mService.discoverServices(key, s);
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Stop service discovery initiated with {@link #discoverServices}.  An active service
+     * discovery is notified to the application with {@link DiscoveryListener#onDiscoveryStarted}
+     * and it stays active until the application invokes a stop service discovery. A successful
+     * stop is notified to with a call to {@link DiscoveryListener#onDiscoveryStopped}.
+     *
+     * <p> Upon failure to stop service discovery, application is notified through
+     * {@link DiscoveryListener#onStopDiscoveryFailed}.
+     *
+     * @param listener This should be the listener object that was passed to {@link #discoverServices}.
+     * It identifies the discovery that should be stopped and notifies of a successful or
+     * unsuccessful stop.  In API versions 20 and above, the listener object may be used for
+     * another service discovery once the callback has been called.  In API versions <= 19,
+     * there is no entirely reliable way to know when a listener may be re-used, and a new
+     * listener should be created for each service discovery request.
+     */
+    public void stopServiceDiscovery(DiscoveryListener listener) {
+        int id = getListenerKey(listener);
+        try {
+            mService.stopDiscovery(id);
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Resolve a discovered service. An application can resolve a service right before
+     * establishing a connection to fetch the IP and port details on which to setup
+     * the connection.
+     *
+     * @param serviceInfo service to be resolved
+     * @param listener to receive callback upon success or failure. Cannot be null.
+     * Cannot be in use for an active service resolution.
+     */
+    public void resolveService(NsdServiceInfo serviceInfo, ResolveListener listener) {
+        checkServiceInfo(serviceInfo);
+        int key = putListener(listener, serviceInfo);
+        try {
+            mService.resolveService(key, serviceInfo);
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+        }
+    }
+
+    private static void checkListener(Object listener) {
+        checkNotNull(listener, "listener cannot be null");
+    }
+
+    private static void checkProtocol(int protocolType) {
+        checkArgument(protocolType == PROTOCOL_DNS_SD, "Unsupported protocol");
+    }
+
+    private static void checkServiceInfo(NsdServiceInfo serviceInfo) {
+        checkNotNull(serviceInfo, "NsdServiceInfo cannot be null");
+        checkStringNotEmpty(serviceInfo.getServiceName(), "Service name cannot be empty");
+        checkStringNotEmpty(serviceInfo.getServiceType(), "Service type cannot be empty");
+    }
+}
diff --git a/packages/Nsd/framework/src/android/net/nsd/NsdServiceInfo.java b/packages/Nsd/framework/src/android/net/nsd/NsdServiceInfo.java
new file mode 100644
index 0000000..0946499
--- /dev/null
+++ b/packages/Nsd/framework/src/android/net/nsd/NsdServiceInfo.java
@@ -0,0 +1,391 @@
+/*
+ * 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.nsd;
+
+import android.annotation.NonNull;
+import android.compat.annotation.UnsupportedAppUsage;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.text.TextUtils;
+import android.util.ArrayMap;
+import android.util.Base64;
+import android.util.Log;
+
+import java.io.UnsupportedEncodingException;
+import java.net.InetAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.Map;
+
+/**
+ * A class representing service information for network service discovery
+ * {@see NsdManager}
+ */
+public final class NsdServiceInfo implements Parcelable {
+
+    private static final String TAG = "NsdServiceInfo";
+
+    private String mServiceName;
+
+    private String mServiceType;
+
+    private final ArrayMap<String, byte[]> mTxtRecord = new ArrayMap<>();
+
+    private InetAddress mHost;
+
+    private int mPort;
+
+    public NsdServiceInfo() {
+    }
+
+    /** @hide */
+    public NsdServiceInfo(String sn, String rt) {
+        mServiceName = sn;
+        mServiceType = rt;
+    }
+
+    /** Get the service name */
+    public String getServiceName() {
+        return mServiceName;
+    }
+
+    /** Set the service name */
+    public void setServiceName(String s) {
+        mServiceName = s;
+    }
+
+    /** Get the service type */
+    public String getServiceType() {
+        return mServiceType;
+    }
+
+    /** Set the service type */
+    public void setServiceType(String s) {
+        mServiceType = s;
+    }
+
+    /** Get the host address. The host address is valid for a resolved service. */
+    public InetAddress getHost() {
+        return mHost;
+    }
+
+    /** Set the host address */
+    public void setHost(InetAddress s) {
+        mHost = s;
+    }
+
+    /** Get port number. The port number is valid for a resolved service. */
+    public int getPort() {
+        return mPort;
+    }
+
+    /** Set port number */
+    public void setPort(int p) {
+        mPort = p;
+    }
+
+    /**
+     * Unpack txt information from a base-64 encoded byte array.
+     *
+     * @param rawRecords The raw base64 encoded records string read from netd.
+     *
+     * @hide
+     */
+    public void setTxtRecords(@NonNull String rawRecords) {
+        byte[] txtRecordsRawBytes = Base64.decode(rawRecords, Base64.DEFAULT);
+
+        // There can be multiple TXT records after each other. Each record has to following format:
+        //
+        // byte                  type                  required   meaning
+        // -------------------   -------------------   --------   ----------------------------------
+        // 0                     unsigned 8 bit        yes        size of record excluding this byte
+        // 1 - n                 ASCII but not '='     yes        key
+        // n + 1                 '='                   optional   separator of key and value
+        // n + 2 - record size   uninterpreted bytes   optional   value
+        //
+        // Example legal records:
+        // [11, 'm', 'y', 'k', 'e', 'y', '=', 0x0, 0x4, 0x65, 0x7, 0xff]
+        // [17, 'm', 'y', 'K', 'e', 'y', 'W', 'i', 't', 'h', 'N', 'o', 'V', 'a', 'l', 'u', 'e', '=']
+        // [12, 'm', 'y', 'B', 'o', 'o', 'l', 'e', 'a', 'n', 'K', 'e', 'y']
+        //
+        // Example corrupted records
+        // [3, =, 1, 2]    <- key is empty
+        // [3, 0, =, 2]    <- key contains non-ASCII character. We handle this by replacing the
+        //                    invalid characters instead of skipping the record.
+        // [30, 'a', =, 2] <- length exceeds total left over bytes in the TXT records array, we
+        //                    handle this by reducing the length of the record as needed.
+        int pos = 0;
+        while (pos < txtRecordsRawBytes.length) {
+            // recordLen is an unsigned 8 bit value
+            int recordLen = txtRecordsRawBytes[pos] & 0xff;
+            pos += 1;
+
+            try {
+                if (recordLen == 0) {
+                    throw new IllegalArgumentException("Zero sized txt record");
+                } else if (pos + recordLen > txtRecordsRawBytes.length) {
+                    Log.w(TAG, "Corrupt record length (pos = " + pos + "): " + recordLen);
+                    recordLen = txtRecordsRawBytes.length - pos;
+                }
+
+                // Decode key-value records
+                String key = null;
+                byte[] value = null;
+                int valueLen = 0;
+                for (int i = pos; i < pos + recordLen; i++) {
+                    if (key == null) {
+                        if (txtRecordsRawBytes[i] == '=') {
+                            key = new String(txtRecordsRawBytes, pos, i - pos,
+                                    StandardCharsets.US_ASCII);
+                        }
+                    } else {
+                        if (value == null) {
+                            value = new byte[recordLen - key.length() - 1];
+                        }
+                        value[valueLen] = txtRecordsRawBytes[i];
+                        valueLen++;
+                    }
+                }
+
+                // If '=' was not found we have a boolean record
+                if (key == null) {
+                    key = new String(txtRecordsRawBytes, pos, recordLen, StandardCharsets.US_ASCII);
+                }
+
+                if (TextUtils.isEmpty(key)) {
+                    // Empty keys are not allowed (RFC6763 6.4)
+                    throw new IllegalArgumentException("Invalid txt record (key is empty)");
+                }
+
+                if (getAttributes().containsKey(key)) {
+                    // When we have a duplicate record, the later ones are ignored (RFC6763 6.4)
+                    throw new IllegalArgumentException("Invalid txt record (duplicate key \"" + key + "\")");
+                }
+
+                setAttribute(key, value);
+            } catch (IllegalArgumentException e) {
+                Log.e(TAG, "While parsing txt records (pos = " + pos + "): " + e.getMessage());
+            }
+
+            pos += recordLen;
+        }
+    }
+
+    /** @hide */
+    @UnsupportedAppUsage
+    public void setAttribute(String key, byte[] value) {
+        if (TextUtils.isEmpty(key)) {
+            throw new IllegalArgumentException("Key cannot be empty");
+        }
+
+        // Key must be printable US-ASCII, excluding =.
+        for (int i = 0; i < key.length(); ++i) {
+            char character = key.charAt(i);
+            if (character < 0x20 || character > 0x7E) {
+                throw new IllegalArgumentException("Key strings must be printable US-ASCII");
+            } else if (character == 0x3D) {
+                throw new IllegalArgumentException("Key strings must not include '='");
+            }
+        }
+
+        // Key length + value length must be < 255.
+        if (key.length() + (value == null ? 0 : value.length) >= 255) {
+            throw new IllegalArgumentException("Key length + value length must be < 255 bytes");
+        }
+
+        // Warn if key is > 9 characters, as recommended by RFC 6763 section 6.4.
+        if (key.length() > 9) {
+            Log.w(TAG, "Key lengths > 9 are discouraged: " + key);
+        }
+
+        // Check against total TXT record size limits.
+        // Arbitrary 400 / 1300 byte limits taken from RFC 6763 section 6.2.
+        int txtRecordSize = getTxtRecordSize();
+        int futureSize = txtRecordSize + key.length() + (value == null ? 0 : value.length) + 2;
+        if (futureSize > 1300) {
+            throw new IllegalArgumentException("Total length of attributes must be < 1300 bytes");
+        } else if (futureSize > 400) {
+            Log.w(TAG, "Total length of all attributes exceeds 400 bytes; truncation may occur");
+        }
+
+        mTxtRecord.put(key, value);
+    }
+
+    /**
+     * Add a service attribute as a key/value pair.
+     *
+     * <p> Service attributes are included as DNS-SD TXT record pairs.
+     *
+     * <p> The key must be US-ASCII printable characters, excluding the '=' character.  Values may
+     * be UTF-8 strings or null.  The total length of key + value must be less than 255 bytes.
+     *
+     * <p> Keys should be short, ideally no more than 9 characters, and unique per instance of
+     * {@link NsdServiceInfo}.  Calling {@link #setAttribute} twice with the same key will overwrite
+     * first value.
+     */
+    public void setAttribute(String key, String value) {
+        try {
+            setAttribute(key, value == null ? (byte []) null : value.getBytes("UTF-8"));
+        } catch (UnsupportedEncodingException e) {
+            throw new IllegalArgumentException("Value must be UTF-8");
+        }
+    }
+
+    /** Remove an attribute by key */
+    public void removeAttribute(String key) {
+        mTxtRecord.remove(key);
+    }
+
+    /**
+     * Retrieve attributes as a map of String keys to byte[] values. The attributes map is only
+     * valid for a resolved service.
+     *
+     * <p> The returned map is unmodifiable; changes must be made through {@link #setAttribute} and
+     * {@link #removeAttribute}.
+     */
+    public Map<String, byte[]> getAttributes() {
+        return Collections.unmodifiableMap(mTxtRecord);
+    }
+
+    private int getTxtRecordSize() {
+        int txtRecordSize = 0;
+        for (Map.Entry<String, byte[]> entry : mTxtRecord.entrySet()) {
+            txtRecordSize += 2;  // One for the length byte, one for the = between key and value.
+            txtRecordSize += entry.getKey().length();
+            byte[] value = entry.getValue();
+            txtRecordSize += value == null ? 0 : value.length;
+        }
+        return txtRecordSize;
+    }
+
+    /** @hide */
+    public @NonNull byte[] getTxtRecord() {
+        int txtRecordSize = getTxtRecordSize();
+        if (txtRecordSize == 0) {
+            return new byte[]{};
+        }
+
+        byte[] txtRecord = new byte[txtRecordSize];
+        int ptr = 0;
+        for (Map.Entry<String, byte[]> entry : mTxtRecord.entrySet()) {
+            String key = entry.getKey();
+            byte[] value = entry.getValue();
+
+            // One byte to record the length of this key/value pair.
+            txtRecord[ptr++] = (byte) (key.length() + (value == null ? 0 : value.length) + 1);
+
+            // The key, in US-ASCII.
+            // Note: use the StandardCharsets const here because it doesn't raise exceptions and we
+            // already know the key is ASCII at this point.
+            System.arraycopy(key.getBytes(StandardCharsets.US_ASCII), 0, txtRecord, ptr,
+                    key.length());
+            ptr += key.length();
+
+            // US-ASCII '=' character.
+            txtRecord[ptr++] = (byte)'=';
+
+            // The value, as any raw bytes.
+            if (value != null) {
+                System.arraycopy(value, 0, txtRecord, ptr, value.length);
+                ptr += value.length;
+            }
+        }
+        return txtRecord;
+    }
+
+    public String toString() {
+        StringBuffer sb = new StringBuffer();
+
+        sb.append("name: ").append(mServiceName)
+                .append(", type: ").append(mServiceType)
+                .append(", host: ").append(mHost)
+                .append(", port: ").append(mPort);
+
+        byte[] txtRecord = getTxtRecord();
+        if (txtRecord != null) {
+            sb.append(", txtRecord: ").append(new String(txtRecord, StandardCharsets.UTF_8));
+        }
+        return sb.toString();
+    }
+
+    /** Implement the Parcelable interface */
+    public int describeContents() {
+        return 0;
+    }
+
+    /** Implement the Parcelable interface */
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeString(mServiceName);
+        dest.writeString(mServiceType);
+        if (mHost != null) {
+            dest.writeInt(1);
+            dest.writeByteArray(mHost.getAddress());
+        } else {
+            dest.writeInt(0);
+        }
+        dest.writeInt(mPort);
+
+        // TXT record key/value pairs.
+        dest.writeInt(mTxtRecord.size());
+        for (String key : mTxtRecord.keySet()) {
+            byte[] value = mTxtRecord.get(key);
+            if (value != null) {
+                dest.writeInt(1);
+                dest.writeInt(value.length);
+                dest.writeByteArray(value);
+            } else {
+                dest.writeInt(0);
+            }
+            dest.writeString(key);
+        }
+    }
+
+    /** Implement the Parcelable interface */
+    public static final @android.annotation.NonNull Creator<NsdServiceInfo> CREATOR =
+        new Creator<NsdServiceInfo>() {
+            public NsdServiceInfo createFromParcel(Parcel in) {
+                NsdServiceInfo info = new NsdServiceInfo();
+                info.mServiceName = in.readString();
+                info.mServiceType = in.readString();
+
+                if (in.readInt() == 1) {
+                    try {
+                        info.mHost = InetAddress.getByAddress(in.createByteArray());
+                    } catch (java.net.UnknownHostException e) {}
+                }
+
+                info.mPort = in.readInt();
+
+                // TXT record key/value pairs.
+                int recordCount = in.readInt();
+                for (int i = 0; i < recordCount; ++i) {
+                    byte[] valueArray = null;
+                    if (in.readInt() == 1) {
+                        int valueLength = in.readInt();
+                        valueArray = new byte[valueLength];
+                        in.readByteArray(valueArray);
+                    }
+                    info.mTxtRecord.put(in.readString(), valueArray);
+                }
+                return info;
+            }
+
+            public NsdServiceInfo[] newArray(int size) {
+                return new NsdServiceInfo[size];
+            }
+        };
+}