Partially revert "Add MDNS discovery"

This partially reverts commit 8f8a09a99a.

Removing MDNS to do one last bugfix-only release.

res/values/strings.xml

@@ -549,8 +549,6 @@ SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted
 
     <string name="plugin_stats">Plugin stats</string>
 
-    <string name="enable_udp_broadcast">Enable UDP device discovery</string>
-
     <string name="receive_notifications_permission_explanation">Notifications need to be allowed to receive them from other devices</string>
     <string name="findmyphone_notifications_explanation">The notifications permission is needed so the phone can ring when the app is in the background</string>
     <string name="no_notifications">Notifications are disabled, you won\'t receive incoming pair notifications.</string>

src/org/kde/kdeconnect/Backends/LanBackend/LanLinkProvider.java

@@ -28,7 +28,6 @@ import org.kde.kdeconnect.Helpers.TrustedNetworkHelper;
 import org.kde.kdeconnect.KdeConnect;
 import org.kde.kdeconnect.NetworkPacket;
 import org.kde.kdeconnect.UserInterface.CustomDevicesActivity;
-import org.kde.kdeconnect.UserInterface.SettingsFragment;
 
 import java.io.BufferedReader;
 import java.io.IOException;
@@ -62,9 +61,9 @@ import kotlin.text.Charsets;
  */
 public class LanLinkProvider extends BaseLinkProvider {
 
-    final static int UDP_PORT = 1716;
+    private final static int UDP_PORT = 1716;
-    final static int MIN_PORT = 1716;
+    private final static int MIN_PORT = 1716;
-    final static int MAX_PORT = 1764;
+    private final static int MAX_PORT = 1764;
     final static int PAYLOAD_TRANSFER_MIN_PORT = 1739;
 
     final static int MAX_UDP_PACKET_SIZE = 1024 * 512;
@@ -73,15 +72,13 @@ public class LanLinkProvider extends BaseLinkProvider {
 
     private final Context context;
 
-    final HashMap<String, LanLink> visibleDevices = new HashMap<>();  //Links by device id
+    private final HashMap<String, LanLink> visibleDevices = new HashMap<>(); // Links by device id
 
     final ConcurrentHashMap<String, Long> lastConnectionTime = new ConcurrentHashMap<>();
 
     private ServerSocket tcpServer;
     private DatagramSocket udpServer;
 
-    private MdnsDiscovery mdnsDiscovery;
-
     private long lastBroadcast = 0;
     private final static long delayBetweenBroadcasts = 200;
 
@@ -271,7 +268,6 @@ public class LanLinkProvider extends BaseLinkProvider {
 
     public LanLinkProvider(Context context) {
         this.context = context;
-        this.mdnsDiscovery = new MdnsDiscovery(context, this);
     }
 
     private void setupUdpListener() {
@@ -359,11 +355,6 @@ public class LanLinkProvider extends BaseLinkProvider {
     }
 
     private void broadcastUdpIdentityPacket(@Nullable Network network) {
-        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
-        if (!preferences.getBoolean(SettingsFragment.KEY_UDP_BROADCAST_ENABLED, true)) {
-            Log.i("LanLinkProvider", "UDP broadcast is disabled in settings. Skipping.");
-            return;
-        }
 
         ThreadHelper.execute(() -> {
             List<String> ipStringList = CustomDevicesActivity
@@ -451,9 +442,6 @@ public class LanLinkProvider extends BaseLinkProvider {
             setupUdpListener();
             setupTcpListener();
 
-            mdnsDiscovery.startDiscovering();
-            mdnsDiscovery.startAnnouncing();
-
             broadcastUdpIdentityPacket(null);
         }
     }
@@ -467,16 +455,12 @@ public class LanLinkProvider extends BaseLinkProvider {
         lastBroadcast = System.currentTimeMillis();
 
         broadcastUdpIdentityPacket(network);
-        mdnsDiscovery.stopDiscovering();
-        mdnsDiscovery.startDiscovering();
     }
 
     @Override
     public void onStop() {
         //Log.i("KDE/LanLinkProvider", "onStop");
         listening = false;
-        mdnsDiscovery.stopAnnouncing();
-        mdnsDiscovery.stopDiscovering();
         try {
             tcpServer.close();
         } catch (Exception e) {

src/org/kde/kdeconnect/Backends/LanBackend/MdnsDiscovery.java

@@ -1,224 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2023 Albert Vaca Cintora <albertvaka@gmail.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
- */
-
-
-package org.kde.kdeconnect.Backends.LanBackend;
-
-import android.content.Context;
-import android.net.nsd.NsdManager;
-import android.net.nsd.NsdServiceInfo;
-import android.net.wifi.WifiManager;
-import android.util.Log;
-
-import org.kde.kdeconnect.Helpers.DeviceHelper;
-
-import java.net.InetAddress;
-import java.util.Collections;
-
-public class MdnsDiscovery {
-
-    static final String LOG_TAG = "MdnsDiscovery";
-
-    static final String SERVICE_TYPE = "_kdeconnect._udp";
-
-    private final Context context;
-
-    private final LanLinkProvider lanLinkProvider;
-
-    private final NsdManager mNsdManager;
-    private NsdManager.RegistrationListener registrationListener;
-    private NsdManager.DiscoveryListener discoveryListener;
-
-    private WifiManager.MulticastLock multicastLock;
-
-    private NsdResolveQueue mNsdResolveQueue;
-
-    public MdnsDiscovery(Context context, LanLinkProvider lanLinkProvider) {
-        this.context = context;
-        this.lanLinkProvider = lanLinkProvider;
-        this.mNsdManager = (NsdManager) context.getSystemService(Context.NSD_SERVICE);
-        this.mNsdResolveQueue = new NsdResolveQueue(this.mNsdManager);
-        WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
-        multicastLock = wifiManager.createMulticastLock("kdeConnectMdnsMulticastLock");
-    }
-
-    void startDiscovering() {
-        if (discoveryListener == null) {
-            multicastLock.acquire();
-            discoveryListener = createDiscoveryListener();
-            mNsdManager.discoverServices(SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD, discoveryListener);
-        }
-    }
-
-    void stopDiscovering() {
-        try {
-            if (discoveryListener != null) {
-                mNsdManager.stopServiceDiscovery(discoveryListener);
-                multicastLock.release();
-            }
-        } catch(IllegalArgumentException e) {
-            // Ignore "listener not registered" exception
-        }
-        discoveryListener = null;
-    }
-
-    void stopAnnouncing() {
-        try {
-            if (registrationListener != null) {
-                mNsdManager.unregisterService(registrationListener);
-            }
-        } catch(IllegalArgumentException e) {
-            // Ignore "listener not registered" exception
-        }
-        registrationListener = null;
-    }
-
-    void startAnnouncing() {
-        if (registrationListener == null) {
-            NsdServiceInfo serviceInfo;
-            try {
-                serviceInfo = createNsdServiceInfo();
-            } catch (IllegalAccessException e) {
-                Log.w(LOG_TAG, "Couldn't start announcing via MDNS: " + e.getMessage());
-                return;
-            }
-            registrationListener = createRegistrationListener();
-            mNsdManager.registerService(serviceInfo, NsdManager.PROTOCOL_DNS_SD, registrationListener);
-        }
-    }
-
-    NsdManager.RegistrationListener createRegistrationListener() {
-        return new NsdManager.RegistrationListener() {
-
-            @Override
-            public void onServiceRegistered(NsdServiceInfo serviceInfo) {
-                // If Android changed the service name to avoid conflicts, here we can read it.
-                Log.i(LOG_TAG, "Registered " + serviceInfo.getServiceName());
-            }
-
-            @Override
-            public void onRegistrationFailed(NsdServiceInfo serviceInfo, int errorCode) {
-                Log.e(LOG_TAG, "Registration failed with: " + errorCode);
-            }
-
-            @Override
-            public void onServiceUnregistered(NsdServiceInfo serviceInfo) {
-                Log.d(LOG_TAG, "Service unregistered: " + serviceInfo);
-            }
-
-            @Override
-            public void onUnregistrationFailed(NsdServiceInfo serviceInfo, int errorCode) {
-                Log.e(LOG_TAG, "Unregister of " + serviceInfo + " failed with: " + errorCode);
-            }
-        };
-    }
-
-    public NsdServiceInfo createNsdServiceInfo() throws IllegalAccessException {
-        NsdServiceInfo serviceInfo = new NsdServiceInfo();
-
-        String deviceId = DeviceHelper.getDeviceId(context);
-        // Without resolving the DNS, the service name is the only info we have so it must be sufficient to identify a device.
-        // Also, it must be unique, otherwise it will be automatically renamed. For these reasons we use the deviceId.
-        serviceInfo.setServiceName(deviceId);
-        serviceInfo.setServiceType(SERVICE_TYPE);
-        serviceInfo.setPort(LanLinkProvider.UDP_PORT);
-
-        // The following fields aren't really used for anything, since we can't include enough info
-        // for it to be useful (namely: we can't include the device certificate).
-        // Each field (key + value) needs to be < 255 bytes. All the fields combined need to be < 1300 bytes.
-        // Also, on Android Lollipop those fields aren't resolved.
-        String deviceName = DeviceHelper.getDeviceName(context);
-        String deviceType = DeviceHelper.getDeviceType(context).toString();
-        String protocolVersion = Integer.toString(DeviceHelper.ProtocolVersion);
-        serviceInfo.setAttribute("id", deviceId);
-        serviceInfo.setAttribute("name", deviceName);
-        serviceInfo.setAttribute("type", deviceType);
-        serviceInfo.setAttribute("protocol", protocolVersion);
-
-        Log.i(LOG_TAG, "My MDNS info: " + serviceInfo);
-
-        return serviceInfo;
-    }
-
-    NsdManager.DiscoveryListener createDiscoveryListener() {
-        return new NsdManager.DiscoveryListener() {
-
-            final String myId = DeviceHelper.getDeviceId(context);
-
-            @Override
-            public void onDiscoveryStarted(String serviceType) {
-                Log.i(LOG_TAG, "Service discovery started: " + serviceType);
-            }
-
-            @Override
-            public void onServiceFound(NsdServiceInfo serviceInfo) {
-                Log.d(LOG_TAG, "Service discovered: " + serviceInfo);
-
-                String deviceId = serviceInfo.getServiceName();
-
-                if (myId.equals(deviceId)) {
-                    Log.d(LOG_TAG, "Discovered myself, ignoring.");
-                    return;
-                }
-
-                if (lanLinkProvider.visibleDevices.containsKey(deviceId)) {
-                    Log.i(LOG_TAG, "MDNS discovered " + deviceId + " to which I'm already connected to. Ignoring.");
-                    return;
-                }
-
-                // We use a queue because only one service can be resolved at
-                // a time, otherwise we get error 3 (already active) in onResolveFailed.
-                mNsdResolveQueue.resolveOrEnqueue(serviceInfo, createResolveListener());
-            }
-
-            @Override
-            public void onServiceLost(NsdServiceInfo serviceInfo) {
-                Log.w(LOG_TAG, "Service lost: " + serviceInfo);
-                // We can't see this device via mdns. This probably means it's not reachable anymore
-                // but we do nothing here since we have other ways to do detect unreachable devices
-                // that hopefully will also trigger.
-            }
-
-            @Override
-            public void onDiscoveryStopped(String serviceType) {
-                Log.i(LOG_TAG, "MDNS discovery stopped: " + serviceType);
-            }
-
-            @Override
-            public void onStartDiscoveryFailed(String serviceType, int errorCode) {
-                Log.e(LOG_TAG, "MDNS discovery start failed: " + errorCode);
-            }
-
-            @Override
-            public void onStopDiscoveryFailed(String serviceType, int errorCode) {
-                Log.e(LOG_TAG, "MDNS discovery stop failed: " + errorCode);
-            }
-        };
-    }
-
-
-    /**
-     * Returns a new listener instance since NsdManager wants a different listener each time you call resolveService
-     */
-    NsdManager.ResolveListener createResolveListener() {
-        return new NsdManager.ResolveListener() {
-            @Override
-            public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {
-                Log.w(LOG_TAG, "MDNS error " + errorCode + " resolving service: " + serviceInfo);
-            }
-
-            @Override
-            public void onServiceResolved(NsdServiceInfo serviceInfo) {
-                Log.i(LOG_TAG, "MDNS successfully resolved " + serviceInfo);
-
-                // Let the LanLinkProvider handle the connection
-                InetAddress remoteAddress = serviceInfo.getHost();
-                lanLinkProvider.sendUdpIdentityPacket(Collections.singletonList(remoteAddress), null);
-            }
-        };
-    }
-
-}

src/org/kde/kdeconnect/Backends/LanBackend/NsdResolveQueue.java

@@ -1,91 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2023 Albert Vaca Cintora <albertvaka@gmail.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
- */
-
-package org.kde.kdeconnect.Backends.LanBackend;
-
-import android.net.nsd.NsdManager;
-import android.net.nsd.NsdServiceInfo;
-import android.util.Log;
-
-import androidx.annotation.NonNull;
-
-import java.util.LinkedList;
-
-public class NsdResolveQueue {
-
-    static final String LOG_TAG = "NsdResolveQueue";
-
-    final @NonNull NsdManager mNsdManager;
-
-    private final Object mLock = new Object();
-    private final LinkedList<PendingResolve> mResolveRequests = new LinkedList<>();
-
-    public NsdResolveQueue(NsdManager nsdManager) {
-        this.mNsdManager = nsdManager;
-    }
-
-    private static class PendingResolve {
-        final @NonNull NsdServiceInfo serviceInfo;
-        final @NonNull NsdManager.ResolveListener listener;
-
-        private PendingResolve(@NonNull NsdServiceInfo serviceInfo, @NonNull NsdManager.ResolveListener listener) {
-            this.serviceInfo = serviceInfo;
-            this.listener = listener;
-        }
-    }
-
-    public void resolveOrEnqueue(@NonNull NsdServiceInfo serviceInfo, @NonNull NsdManager.ResolveListener listener) {
-        synchronized (mLock) {
-            for (PendingResolve existing : mResolveRequests) {
-                if (serviceInfo.getServiceName().equals(existing.serviceInfo.getServiceName())) {
-                    Log.i(LOG_TAG, "Not enqueuing a new resolve request for the same service: " + serviceInfo.getServiceName());
-                    return;
-                }
-            }
-            mResolveRequests.addLast(new PendingResolve(serviceInfo, new ListenerWrapper(listener)));
-
-            if (mResolveRequests.size() == 1) {
-                resolveNextRequest();
-            }
-        }
-    }
-
-    private class ListenerWrapper implements NsdManager.ResolveListener {
-        private final @NonNull NsdManager.ResolveListener mListener;
-
-        private ListenerWrapper(@NonNull NsdManager.ResolveListener listener) {
-            mListener = listener;
-        }
-
-        @Override
-        public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {
-            mListener.onResolveFailed(serviceInfo, errorCode);
-
-            synchronized (mLock) {
-                mResolveRequests.pop();
-                resolveNextRequest();
-            }
-        }
-
-        @Override
-        public void onServiceResolved(NsdServiceInfo serviceInfo) {
-            mListener.onServiceResolved(serviceInfo);
-
-            synchronized (mLock) {
-                mResolveRequests.pop();
-                resolveNextRequest();
-            }
-        }
-    }
-
-    private void resolveNextRequest() {
-        if (!mResolveRequests.isEmpty()) {
-            PendingResolve request = mResolveRequests.getFirst();
-            mNsdManager.resolveService(request.serviceInfo, request.listener);
-        }
-    }
-
-}

src/org/kde/kdeconnect/UserInterface/SettingsFragment.java

@@ -37,7 +37,6 @@ import org.kde.kdeconnect_tp.R;
 
 public class SettingsFragment extends PreferenceFragmentCompat {
 
-    public static final String KEY_UDP_BROADCAST_ENABLED = "udp_broadcast_enabled";
     public static final String KEY_APP_THEME = "theme_pref";
 
     private EditTextPreference renameDevice;
@@ -171,12 +170,6 @@ public class SettingsFragment extends PreferenceFragmentCompat {
             return true;
         });
 
-        // UDP broadcast toggle
-        final TwoStatePreference udpBroadcastDiscovery = new SwitchPreference(context);
-        udpBroadcastDiscovery.setDefaultValue(true);
-        udpBroadcastDiscovery.setKey(KEY_UDP_BROADCAST_ENABLED);
-        udpBroadcastDiscovery.setTitle(R.string.enable_udp_broadcast);
-        screen.addPreference(udpBroadcastDiscovery);
 
         // More settings text
         Preference moreSettingsText = new Preference(context);