Use NsdManager for mDNS discovery on Android 14

app/src/main/AndroidManifest.xml

@@ -5,11 +5,15 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.VIBRATE" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
-    <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
     <uses-permission android:name="com.android.providers.tv.permission.READ_EPG_DATA"/>
     <uses-permission android:name="com.android.providers.tv.permission.WRITE_EPG_DATA"/>
 
+    <!-- We don't need a MulticastLock on API level 34+ because we use NsdManager for mDNS -->
+    <uses-permission
+        android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE"
+        android:maxSdkVersion="33" />
+
     <uses-feature
         android:name="android.hardware.touchscreen"
         android:required="false" />

app/src/main/java/com/limelight/discovery/DiscoveryService.java

@@ -3,22 +3,21 @@ package com.limelight.discovery;
 import java.util.List;
 
 import com.limelight.nvstream.mdns.MdnsComputer;
+import com.limelight.nvstream.mdns.JmDNSDiscoveryAgent;
 import com.limelight.nvstream.mdns.MdnsDiscoveryAgent;
 import com.limelight.nvstream.mdns.MdnsDiscoveryListener;
+import com.limelight.nvstream.mdns.NsdManagerDiscoveryAgent;
 
 import android.app.Service;
-import android.content.Context;
 import android.content.Intent;
-import android.net.wifi.WifiManager;
-import android.net.wifi.WifiManager.MulticastLock;
 import android.os.Binder;
+import android.os.Build;
 import android.os.IBinder;
 
 public class DiscoveryService extends Service {
 
     private MdnsDiscoveryAgent discoveryAgent;
     private MdnsDiscoveryListener boundListener;
-    private MulticastLock multicastLock;
 
     public class DiscoveryBinder extends Binder {
         public void setListener(MdnsDiscoveryListener listener) {
@@ -26,13 +25,11 @@ public class DiscoveryService extends Service {
         }
 
         public void startDiscovery(int queryIntervalMs) {
-            multicastLock.acquire();
             discoveryAgent.startDiscovery(queryIntervalMs);
         }
 
         public void stopDiscovery() {
             discoveryAgent.stopDiscovery();
-            multicastLock.release();
         }
 
         public List<MdnsComputer> getComputerSet() {
@@ -42,11 +39,7 @@ public class DiscoveryService extends Service {
 
     @Override
     public void onCreate() {
-        WifiManager wifiMgr = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
-        multicastLock = wifiMgr.createMulticastLock("Limelight mDNS");
-        multicastLock.setReferenceCounted(false);
-
-        discoveryAgent = new MdnsDiscoveryAgent(new MdnsDiscoveryListener() {
+        MdnsDiscoveryListener listener = new MdnsDiscoveryListener() {
             @Override
             public void notifyComputerAdded(MdnsComputer computer) {
                 if (boundListener != null) {
@@ -60,7 +53,22 @@ public class DiscoveryService extends Service {
                     boundListener.notifyDiscoveryFailure(e);
                 }
             }
-        });
+        };
+
+        // Prior to Android 14, NsdManager doesn't provide all the capabilities needed for parity
+        // with jmDNS (specifically handling multiple addresses for a single service). There are
+        // also documented reliability bugs early in the Android 4.x series shortly after it was
+        // introduced. The benefit of using NsdManager over jmDNS is that it works correctly in
+        // environments where mDNS proxying is required, like ChromeOS, WSA, and the emulator.
+        //
+        // As such, we use the jmDNS-based MdnsDiscoveryAgent prior to Android 14 and NsdManager
+        // on Android 14 and above.
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
+            discoveryAgent = new JmDNSDiscoveryAgent(getApplicationContext(), listener);
+        }
+        else {
+            discoveryAgent = new NsdManagerDiscoveryAgent(getApplicationContext(), listener);
+        }
     }
 
     private final DiscoveryBinder binder = new DiscoveryBinder();
@@ -74,7 +82,6 @@ public class DiscoveryService extends Service {
     public boolean onUnbind(Intent intent) {
         // Stop any discovery session
         discoveryAgent.stopDiscovery();
-        multicastLock.release();
 
         // Unbind the listener
         boundListener = null;

app/src/main/java/com/limelight/nvstream/mdns/JmDNSDiscoveryAgent.java

@@ -0,0 +1,269 @@
+package com.limelight.nvstream.mdns;
+
+import android.content.Context;
+import android.net.wifi.WifiManager;
+
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.util.ArrayList;
+import java.util.HashSet;
+
+import javax.jmdns.JmmDNS;
+import javax.jmdns.NetworkTopologyDiscovery;
+import javax.jmdns.ServiceEvent;
+import javax.jmdns.ServiceInfo;
+import javax.jmdns.ServiceListener;
+import javax.jmdns.impl.NetworkTopologyDiscoveryImpl;
+
+import com.limelight.LimeLog;
+
+public class JmDNSDiscoveryAgent extends MdnsDiscoveryAgent implements ServiceListener {
+    private static final String SERVICE_TYPE = "_nvstream._tcp.local.";
+    private WifiManager.MulticastLock multicastLock;
+    private Thread discoveryThread;
+    private HashSet<String> pendingResolution = new HashSet<>();
+    
+    // The resolver factory's instance member has a static lifetime which
+    // means our ref count and listener must be static also.
+    private static int resolverRefCount = 0;
+    private static HashSet<ServiceListener> listeners = new HashSet<>();
+    private static ServiceListener nvstreamListener = new ServiceListener() {
+        @Override
+        public void serviceAdded(ServiceEvent event) {
+            HashSet<ServiceListener> localListeners;
+            
+            // Copy the listener set into a new set so we can invoke
+            // the callbacks without holding the listeners monitor the
+            // whole time.
+            synchronized (listeners) {
+                localListeners = new HashSet<ServiceListener>(listeners);
+            }
+            
+            for (ServiceListener listener : localListeners) {
+                listener.serviceAdded(event);
+            }
+        }
+
+        @Override
+        public void serviceRemoved(ServiceEvent event) {
+            HashSet<ServiceListener> localListeners;
+            
+            // Copy the listener set into a new set so we can invoke
+            // the callbacks without holding the listeners monitor the
+            // whole time.
+            synchronized (listeners) {
+                localListeners = new HashSet<ServiceListener>(listeners);
+            }
+            
+            for (ServiceListener listener : localListeners) {
+                listener.serviceRemoved(event);
+            }
+        }
+
+        @Override
+        public void serviceResolved(ServiceEvent event) {
+            HashSet<ServiceListener> localListeners;
+            
+            // Copy the listener set into a new set so we can invoke
+            // the callbacks without holding the listeners monitor the
+            // whole time.
+            synchronized (listeners) {
+                localListeners = new HashSet<ServiceListener>(listeners);
+            }
+            
+            for (ServiceListener listener : localListeners) {
+                listener.serviceResolved(event);
+            }
+        }
+    };
+
+    public static class MyNetworkTopologyDiscovery extends NetworkTopologyDiscoveryImpl {
+        @Override
+        public boolean useInetAddress(NetworkInterface networkInterface, InetAddress interfaceAddress) {
+            // This is an copy of jmDNS's implementation, except we omit the multicast check, since
+            // it seems at least some devices lie about interfaces not supporting multicast when they really do.
+            try {
+                if (!networkInterface.isUp()) {
+                    return false;
+                }
+
+                /*
+                if (!networkInterface.supportsMulticast()) {
+                    return false;
+                }
+                */
+
+                if (networkInterface.isLoopback()) {
+                    return false;
+                }
+
+                return true;
+            } catch (Exception exception) {
+                return false;
+            }
+        }
+    }
+
+    static {
+        // Override jmDNS's default topology discovery class with ours
+        NetworkTopologyDiscovery.Factory.setClassDelegate(new NetworkTopologyDiscovery.Factory.ClassDelegate() {
+            @Override
+            public NetworkTopologyDiscovery newNetworkTopologyDiscovery() {
+                return new MyNetworkTopologyDiscovery();
+            }
+        });
+    }
+
+    private static JmmDNS referenceResolver() {
+        synchronized (JmDNSDiscoveryAgent.class) {
+            JmmDNS instance = JmmDNS.Factory.getInstance();
+            if (++resolverRefCount == 1) {
+                // This will cause the listener to be invoked for known hosts immediately.
+                // JmDNS only supports one listener per service, so we have to do this here
+                // with a static listener.
+                instance.addServiceListener(SERVICE_TYPE, nvstreamListener);
+            }
+            return instance;
+        }
+    }
+
+    private static void dereferenceResolver() {
+        synchronized (JmDNSDiscoveryAgent.class) {
+            if (--resolverRefCount == 0) {
+                try {
+                    JmmDNS.Factory.close();
+                } catch (IOException e) {}
+            }
+        }
+    }
+
+    public JmDNSDiscoveryAgent(Context context, MdnsDiscoveryListener listener) {
+        super(listener);
+
+        // Create the multicast lock required to receive mDNS traffic
+        WifiManager wifiMgr = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
+        multicastLock = wifiMgr.createMulticastLock("Limelight mDNS");
+        multicastLock.setReferenceCounted(false);
+    }
+
+    private void handleResolvedServiceInfo(ServiceInfo info) {
+        synchronized (pendingResolution) {
+            pendingResolution.remove(info.getName());
+        }
+
+        try {
+            handleServiceInfo(info);
+        } catch (UnsupportedEncodingException e) {
+            // Invalid DNS response
+            LimeLog.info("mDNS: Invalid response for machine: "+info.getName());
+            return;
+        }
+    }
+
+    private void handleServiceInfo(ServiceInfo info) throws UnsupportedEncodingException {
+        reportNewComputer(info.getName(), info.getPort(), info.getInet4Addresses(), info.getInet6Addresses());
+    }
+    
+    public void startDiscovery(final int discoveryIntervalMs) {
+        // Kill any existing discovery before starting a new one
+        stopDiscovery();
+
+        // Acquire the multicast lock to start receiving mDNS traffic
+        multicastLock.acquire();
+        
+        // Add our listener to the set
+        synchronized (listeners) {
+            listeners.add(JmDNSDiscoveryAgent.this);
+        }
+        
+        discoveryThread = new Thread() {
+            @Override
+            public void run() {
+                // This may result in listener callbacks so we must register
+                // our listener first.
+                JmmDNS resolver = referenceResolver();
+                
+                try {
+                    while (!Thread.interrupted()) {
+                        // Start an mDNS request
+                        resolver.requestServiceInfo(SERVICE_TYPE, null, discoveryIntervalMs);
+                        
+                        // Run service resolution again for pending machines
+                        ArrayList<String> pendingNames;
+                        synchronized (pendingResolution) {
+                            pendingNames = new ArrayList<String>(pendingResolution);
+                        }
+                        for (String name : pendingNames) {
+                            LimeLog.info("mDNS: Retrying service resolution for machine: "+name);
+                            ServiceInfo[] infos = resolver.getServiceInfos(SERVICE_TYPE, name, 500);
+                            if (infos != null && infos.length != 0) {
+                                LimeLog.info("mDNS: Resolved (retry) with "+infos.length+" service entries");
+                                for (ServiceInfo svcinfo : infos) {
+                                    handleResolvedServiceInfo(svcinfo);
+                                }
+                            }
+                        }
+                        
+                        // Wait for the next polling interval
+                        try {
+                            Thread.sleep(discoveryIntervalMs);
+                        } catch (InterruptedException e) {
+                            break;
+                        }
+                    }
+                }
+                finally {
+                    // Dereference the resolver
+                    dereferenceResolver();
+                }
+            }
+        };
+        discoveryThread.setName("mDNS Discovery Thread");
+        discoveryThread.start();
+    }
+    
+    public void stopDiscovery() {
+        // Release the multicast lock to stop receiving mDNS traffic
+        multicastLock.release();
+
+        // Remove our listener from the set
+        synchronized (listeners) {
+            listeners.remove(JmDNSDiscoveryAgent.this);
+        }
+        
+        // If there's already a running thread, interrupt it
+        if (discoveryThread != null) {
+            discoveryThread.interrupt();
+            discoveryThread = null;
+        }
+    }
+
+    @Override
+    public void serviceAdded(ServiceEvent event) {
+        LimeLog.info("mDNS: Machine appeared: "+event.getInfo().getName());
+
+        ServiceInfo info = event.getDNS().getServiceInfo(SERVICE_TYPE, event.getInfo().getName(), 500);
+        if (info == null) {
+            // This machine is pending resolution
+            synchronized (pendingResolution) {
+                pendingResolution.add(event.getInfo().getName());
+            }
+            return;
+        }
+        
+        LimeLog.info("mDNS: Resolved (blocking)");
+        handleResolvedServiceInfo(info);
+    }
+
+    @Override
+    public void serviceRemoved(ServiceEvent event) {
+        LimeLog.info("mDNS: Machine disappeared: "+event.getInfo().getName());
+    }
+
+    @Override
+    public void serviceResolved(ServiceEvent event) {
+        // We handle this synchronously
+    }
+}

app/src/main/java/com/limelight/nvstream/mdns/MdnsDiscoveryAgent.java

@@ -1,165 +1,64 @@
 package com.limelight.nvstream.mdns;
 
-import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import com.limelight.LimeLog;
+
 import java.net.Inet4Address;
 import java.net.Inet6Address;
-import java.net.InetAddress;
-import java.net.NetworkInterface;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 
-import javax.jmdns.JmmDNS;
-import javax.jmdns.NetworkTopologyDiscovery;
-import javax.jmdns.ServiceEvent;
-import javax.jmdns.ServiceInfo;
-import javax.jmdns.ServiceListener;
-import javax.jmdns.impl.NetworkTopologyDiscoveryImpl;
+public abstract class MdnsDiscoveryAgent {
+    protected MdnsDiscoveryListener listener;
 
-import com.limelight.LimeLog;
-
-public class MdnsDiscoveryAgent implements ServiceListener {
-    public static final String SERVICE_TYPE = "_nvstream._tcp.local.";
-    
-    private MdnsDiscoveryListener listener;
-    private Thread discoveryThread;
-    private HashSet<MdnsComputer> computers = new HashSet<>();
-    private HashSet<String> pendingResolution = new HashSet<>();
-    
-    // The resolver factory's instance member has a static lifetime which
-    // means our ref count and listener must be static also.
-    private static int resolverRefCount = 0;
-    private static HashSet<ServiceListener> listeners = new HashSet<>();
-    private static ServiceListener nvstreamListener = new ServiceListener() {
-        @Override
-        public void serviceAdded(ServiceEvent event) {
-            HashSet<ServiceListener> localListeners;
-            
-            // Copy the listener set into a new set so we can invoke
-            // the callbacks without holding the listeners monitor the
-            // whole time.
-            synchronized (listeners) {
-                localListeners = new HashSet<ServiceListener>(listeners);
-            }
-            
-            for (ServiceListener listener : localListeners) {
-                listener.serviceAdded(event);
-            }
-        }
-
-        @Override
-        public void serviceRemoved(ServiceEvent event) {
-            HashSet<ServiceListener> localListeners;
-            
-            // Copy the listener set into a new set so we can invoke
-            // the callbacks without holding the listeners monitor the
-            // whole time.
-            synchronized (listeners) {
-                localListeners = new HashSet<ServiceListener>(listeners);
-            }
-            
-            for (ServiceListener listener : localListeners) {
-                listener.serviceRemoved(event);
-            }
-        }
-
-        @Override
-        public void serviceResolved(ServiceEvent event) {
-            HashSet<ServiceListener> localListeners;
-            
-            // Copy the listener set into a new set so we can invoke
-            // the callbacks without holding the listeners monitor the
-            // whole time.
-            synchronized (listeners) {
-                localListeners = new HashSet<ServiceListener>(listeners);
-            }
-            
-            for (ServiceListener listener : localListeners) {
-                listener.serviceResolved(event);
-            }
-        }
-    };
-
-    public static class MyNetworkTopologyDiscovery extends NetworkTopologyDiscoveryImpl {
-        @Override
-        public boolean useInetAddress(NetworkInterface networkInterface, InetAddress interfaceAddress) {
-            // This is an copy of jmDNS's implementation, except we omit the multicast check, since
-            // it seems at least some devices lie about interfaces not supporting multicast when they really do.
-            try {
-                if (!networkInterface.isUp()) {
-                    return false;
-                }
-
-                /*
-                if (!networkInterface.supportsMulticast()) {
-                    return false;
-                }
-                */
-
-                if (networkInterface.isLoopback()) {
-                    return false;
-                }
-
-                return true;
-            } catch (Exception exception) {
-                return false;
-            }
-        }
-    }
-
-    static {
-        // Override jmDNS's default topology discovery class with ours
-        NetworkTopologyDiscovery.Factory.setClassDelegate(new NetworkTopologyDiscovery.Factory.ClassDelegate() {
-            @Override
-            public NetworkTopologyDiscovery newNetworkTopologyDiscovery() {
-                return new MyNetworkTopologyDiscovery();
-            }
-        });
-    }
-
-    private static JmmDNS referenceResolver() {
-        synchronized (MdnsDiscoveryAgent.class) {
-            JmmDNS instance = JmmDNS.Factory.getInstance();
-            if (++resolverRefCount == 1) {
-                // This will cause the listener to be invoked for known hosts immediately.
-                // JmDNS only supports one listener per service, so we have to do this here
-                // with a static listener.
-                instance.addServiceListener(SERVICE_TYPE, nvstreamListener);
-            }
-            return instance;
-        }
-    }
-
-    private static void dereferenceResolver() {
-        synchronized (MdnsDiscoveryAgent.class) {
-            if (--resolverRefCount == 0) {
-                try {
-                    JmmDNS.Factory.close();
-                } catch (IOException e) {}
-            }
-        }
-    }
+    protected HashSet<MdnsComputer> computers = new HashSet<>();
 
     public MdnsDiscoveryAgent(MdnsDiscoveryListener listener) {
         this.listener = listener;
     }
 
-    private void handleResolvedServiceInfo(ServiceInfo info) {
-        synchronized (pendingResolution) {
-            pendingResolution.remove(info.getName());
+    public abstract void startDiscovery(final int discoveryIntervalMs);
+
+    public abstract void stopDiscovery();
+
+    protected void reportNewComputer(String name, int port, Inet4Address[] v4Addrs, Inet6Address[] v6Addrs) {
+        LimeLog.info("mDNS: "+name+" has "+v4Addrs.length+" IPv4 addresses");
+        LimeLog.info("mDNS: "+name+" has "+v6Addrs.length+" IPv6 addresses");
+
+        Inet6Address v6GlobalAddr = getBestIpv6Address(v6Addrs);
+
+        // Add a computer object for each IPv4 address reported by the PC
+        for (Inet4Address v4Addr : v4Addrs) {
+            synchronized (computers) {
+                MdnsComputer computer = new MdnsComputer(name, v4Addr, v6GlobalAddr, port);
+                if (computers.add(computer)) {
+                    // This was a new entry
+                    listener.notifyComputerAdded(computer);
+                }
+            }
         }
 
-        try {
-            handleServiceInfo(info);
-        } catch (UnsupportedEncodingException e) {
-            // Invalid DNS response
-            LimeLog.info("mDNS: Invalid response for machine: "+info.getName());
-            return;
+        // If there were no IPv4 addresses, use IPv6 for registration
+        if (v4Addrs.length == 0) {
+            Inet6Address v6LocalAddr = getLocalAddress(v6Addrs);
+
+            if (v6LocalAddr != null || v6GlobalAddr != null) {
+                MdnsComputer computer = new MdnsComputer(name, v6LocalAddr, v6GlobalAddr, port);
+                if (computers.add(computer)) {
+                    // This was a new entry
+                    listener.notifyComputerAdded(computer);
+                }
+            }
         }
     }
 
-    private Inet6Address getLocalAddress(Inet6Address[] addresses) {
+    public List<MdnsComputer> getComputerSet() {
+        synchronized (computers) {
+            return new ArrayList<>(computers);
+        }
+    }
+
+    protected static Inet6Address getLocalAddress(Inet6Address[] addresses) {
         for (Inet6Address addr : addresses) {
             if (addr.isLinkLocalAddress() || addr.isSiteLocalAddress()) {
                 return addr;
@@ -173,7 +72,7 @@ public class MdnsDiscoveryAgent implements ServiceListener {
         return null;
     }
 
-    private Inet6Address getLinkLocalAddress(Inet6Address[] addresses) {
+    protected static Inet6Address getLinkLocalAddress(Inet6Address[] addresses) {
         for (Inet6Address addr : addresses) {
             if (addr.isLinkLocalAddress()) {
                 LimeLog.info("Found link-local address: "+addr.getHostAddress());
@@ -184,7 +83,7 @@ public class MdnsDiscoveryAgent implements ServiceListener {
         return null;
     }
 
-    private Inet6Address getBestIpv6Address(Inet6Address[] addresses) {
+    protected static Inet6Address getBestIpv6Address(Inet6Address[] addresses) {
         // First try to find a link local address, so we can match the interface identifier
         // with a global address (this will work for SLAAC but not DHCPv6).
         Inet6Address linkLocalAddr = getLinkLocalAddress(addresses);
@@ -246,139 +145,4 @@ public class MdnsDiscoveryAgent implements ServiceListener {
 
         return null;
     }
-
-    private void handleServiceInfo(ServiceInfo info) throws UnsupportedEncodingException {
-        Inet4Address v4Addrs[] = info.getInet4Addresses();
-        Inet6Address v6Addrs[] = info.getInet6Addresses();
-
-        LimeLog.info("mDNS: "+info.getName()+" has "+v4Addrs.length+" IPv4 addresses");
-        LimeLog.info("mDNS: "+info.getName()+" has "+v6Addrs.length+" IPv6 addresses");
-
-        Inet6Address v6GlobalAddr = getBestIpv6Address(v6Addrs);
-
-        // Add a computer object for each IPv4 address reported by the PC
-        for (Inet4Address v4Addr : v4Addrs) {
-            synchronized (computers) {
-                MdnsComputer computer = new MdnsComputer(info.getName(), v4Addr, v6GlobalAddr, info.getPort());
-                if (computers.add(computer)) {
-                    // This was a new entry
-                    listener.notifyComputerAdded(computer);
-                }
-            }
-        }
-
-        // If there were no IPv4 addresses, use IPv6 for registration
-        if (v4Addrs.length == 0) {
-            Inet6Address v6LocalAddr = getLocalAddress(v6Addrs);
-
-            if (v6LocalAddr != null || v6GlobalAddr != null) {
-                MdnsComputer computer = new MdnsComputer(info.getName(), v6LocalAddr, v6GlobalAddr, info.getPort());
-                if (computers.add(computer)) {
-                    // This was a new entry
-                    listener.notifyComputerAdded(computer);
-                }
-            }
-        }
-    }
-    
-    public void startDiscovery(final int discoveryIntervalMs) {
-        // Kill any existing discovery before starting a new one
-        stopDiscovery();
-        
-        // Add our listener to the set
-        synchronized (listeners) {
-            listeners.add(MdnsDiscoveryAgent.this);
-        }
-        
-        discoveryThread = new Thread() {
-            @Override
-            public void run() {
-                // This may result in listener callbacks so we must register
-                // our listener first.
-                JmmDNS resolver = referenceResolver();
-                
-                try {
-                    while (!Thread.interrupted()) {
-                        // Start an mDNS request
-                        resolver.requestServiceInfo(SERVICE_TYPE, null, discoveryIntervalMs);
-                        
-                        // Run service resolution again for pending machines
-                        ArrayList<String> pendingNames;
-                        synchronized (pendingResolution) {
-                            pendingNames = new ArrayList<String>(pendingResolution);
-                        }
-                        for (String name : pendingNames) {
-                            LimeLog.info("mDNS: Retrying service resolution for machine: "+name);
-                            ServiceInfo[] infos = resolver.getServiceInfos(SERVICE_TYPE, name, 500);
-                            if (infos != null && infos.length != 0) {
-                                LimeLog.info("mDNS: Resolved (retry) with "+infos.length+" service entries");
-                                for (ServiceInfo svcinfo : infos) {
-                                    handleResolvedServiceInfo(svcinfo);
-                                }
-                            }
-                        }
-                        
-                        // Wait for the next polling interval
-                        try {
-                            Thread.sleep(discoveryIntervalMs);
-                        } catch (InterruptedException e) {
-                            break;
-                        }
-                    }
-                }
-                finally {
-                    // Dereference the resolver
-                    dereferenceResolver();
-                }
-            }
-        };
-        discoveryThread.setName("mDNS Discovery Thread");
-        discoveryThread.start();
-    }
-    
-    public void stopDiscovery() {
-        // Remove our listener from the set
-        synchronized (listeners) {
-            listeners.remove(MdnsDiscoveryAgent.this);
-        }
-        
-        // If there's already a running thread, interrupt it
-        if (discoveryThread != null) {
-            discoveryThread.interrupt();
-            discoveryThread = null;
-        }
-    }
-    
-    public List<MdnsComputer> getComputerSet() {
-        synchronized (computers) {
-            return new ArrayList<>(computers);
-        }
-    }
-
-    @Override
-    public void serviceAdded(ServiceEvent event) {
-        LimeLog.info("mDNS: Machine appeared: "+event.getInfo().getName());
-
-        ServiceInfo info = event.getDNS().getServiceInfo(SERVICE_TYPE, event.getInfo().getName(), 500);
-        if (info == null) {
-            // This machine is pending resolution
-            synchronized (pendingResolution) {
-                pendingResolution.add(event.getInfo().getName());
-            }
-            return;
-        }
-        
-        LimeLog.info("mDNS: Resolved (blocking)");
-        handleResolvedServiceInfo(info);
-    }
-
-    @Override
-    public void serviceRemoved(ServiceEvent event) {
-        LimeLog.info("mDNS: Machine disappeared: "+event.getInfo().getName());
-    }
-
-    @Override
-    public void serviceResolved(ServiceEvent event) {
-        // We handle this synchronously
-    }
 }

app/src/main/java/com/limelight/nvstream/mdns/NsdManagerDiscoveryAgent.java

@@ -0,0 +1,175 @@
+package com.limelight.nvstream.mdns;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.net.nsd.NsdManager;
+import android.net.nsd.NsdServiceInfo;
+import android.os.Build;
+
+import com.limelight.LimeLog;
+
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.util.HashMap;
+import java.util.List;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+@TargetApi(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+public class NsdManagerDiscoveryAgent extends MdnsDiscoveryAgent {
+    private static final String SERVICE_TYPE = "_nvstream._tcp";
+    private NsdManager nsdManager;
+    private boolean discoveryActive;
+    private boolean wantsDiscoveryActive;
+    private final HashMap<String, NsdManager.ServiceInfoCallback> serviceCallbacks = new HashMap<>();
+    private final ThreadPoolExecutor executor = new ThreadPoolExecutor(1, 1, 0, TimeUnit.SECONDS, new LinkedBlockingQueue<>());
+
+    private NsdManager.DiscoveryListener discoveryListener = new NsdManager.DiscoveryListener() {
+        @Override
+        public void onStartDiscoveryFailed(String serviceType, int errorCode) {
+            discoveryActive = false;
+            LimeLog.severe("NSD: Service discovery start failed: " + errorCode);
+            listener.notifyDiscoveryFailure(new RuntimeException("onStartDiscoveryFailed(): " + errorCode));
+        }
+
+        @Override
+        public void onStopDiscoveryFailed(String serviceType, int errorCode) {
+            LimeLog.severe("NSD: Service discovery stop failed: " + errorCode);
+        }
+
+        @Override
+        public void onDiscoveryStarted(String serviceType) {
+            discoveryActive = true;
+            LimeLog.info("NSD: Service discovery started");
+
+            // If we were stopped before we could finish starting, stop now
+            if (!wantsDiscoveryActive) {
+                stopDiscovery();
+            }
+        }
+
+        @Override
+        public void onDiscoveryStopped(String serviceType) {
+            discoveryActive = false;
+            LimeLog.info("NSD: Service discovery stopped");
+
+            // If we were started before we could finish stopping, start again now
+            if (wantsDiscoveryActive) {
+                startDiscovery(0);
+            }
+        }
+
+        @Override
+        public void onServiceFound(NsdServiceInfo nsdServiceInfo) {
+            LimeLog.info("NSD: Machine appeared: "+nsdServiceInfo.getServiceName());
+
+            NsdManager.ServiceInfoCallback serviceInfoCallback = new NsdManager.ServiceInfoCallback() {
+                @Override
+                public void onServiceInfoCallbackRegistrationFailed(int errorCode) {
+                    LimeLog.severe("NSD: Service info callback registration failed: " + errorCode);
+                    listener.notifyDiscoveryFailure(new RuntimeException("onServiceInfoCallbackRegistrationFailed(): " + errorCode));
+                }
+
+                @Override
+                public void onServiceUpdated(NsdServiceInfo nsdServiceInfo) {
+                    LimeLog.info("NSD: Machine resolved: "+nsdServiceInfo.getServiceName());
+                    reportNewComputer(nsdServiceInfo.getServiceName(), nsdServiceInfo.getPort(),
+                            getV4Addrs(nsdServiceInfo.getHostAddresses()),
+                            getV6Addrs(nsdServiceInfo.getHostAddresses()));
+                }
+
+                @Override
+                public void onServiceLost() {}
+
+                @Override
+                public void onServiceInfoCallbackUnregistered() {}
+            };
+
+            nsdManager.registerServiceInfoCallback(nsdServiceInfo, executor, serviceInfoCallback);
+            serviceCallbacks.put(nsdServiceInfo.getServiceName(), serviceInfoCallback);
+        }
+
+        @Override
+        public void onServiceLost(NsdServiceInfo nsdServiceInfo) {
+            LimeLog.info("NSD: Machine lost: "+nsdServiceInfo.getServiceName());
+
+            NsdManager.ServiceInfoCallback serviceInfoCallback = serviceCallbacks.remove(nsdServiceInfo.getServiceName());
+            if (serviceInfoCallback != null) {
+                nsdManager.unregisterServiceInfoCallback(serviceInfoCallback);
+            }
+        }
+    };
+
+    public NsdManagerDiscoveryAgent(Context context, MdnsDiscoveryListener listener) {
+        super(listener);
+        this.nsdManager = context.getSystemService(NsdManager.class);
+    }
+
+    @Override
+    public void startDiscovery(int discoveryIntervalMs) {
+        wantsDiscoveryActive = true;
+
+        // Register the service discovery listener
+        if (!discoveryActive) {
+            nsdManager.discoverServices(SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD, discoveryListener);
+        }
+    }
+
+    @Override
+    public void stopDiscovery() {
+        wantsDiscoveryActive = false;
+
+        // Unregister the service discovery listener
+        if (discoveryActive) {
+            nsdManager.stopServiceDiscovery(discoveryListener);
+        }
+
+        // Unregister all service info callbacks
+        for (NsdManager.ServiceInfoCallback callback : serviceCallbacks.values()) {
+            nsdManager.unregisterServiceInfoCallback(callback);
+        }
+        serviceCallbacks.clear();
+    }
+
+    private static Inet4Address[] getV4Addrs(List<InetAddress> addrs) {
+        int matchCount = 0;
+        for (InetAddress addr : addrs) {
+            if (addr instanceof Inet4Address) {
+                matchCount++;
+            }
+        }
+
+        Inet4Address[] matching = new Inet4Address[matchCount];
+
+        int i = 0;
+        for (InetAddress addr : addrs) {
+            if (addr instanceof Inet4Address) {
+                matching[i++] = (Inet4Address) addr;
+            }
+        }
+
+        return matching;
+    }
+
+    private static Inet6Address[] getV6Addrs(List<InetAddress> addrs) {
+        int matchCount = 0;
+        for (InetAddress addr : addrs) {
+            if (addr instanceof Inet6Address) {
+                matchCount++;
+            }
+        }
+
+        Inet6Address[] matching = new Inet6Address[matchCount];
+
+        int i = 0;
+        for (InetAddress addr : addrs) {
+            if (addr instanceof Inet6Address) {
+                matching[i++] = (Inet6Address) addr;
+            }
+        }
+
+        return matching;
+    }
+}