fix(jellyfin): harden local discovery flow

2026-05-31 14:33:31 +02:00
parent e3db54940d
commit 1b5334e72f
10 changed files with 397 additions and 81 deletions
@@ -0,0 +1,84 @@
+import 'dart:async';
+import 'dart:io';
+
+import 'app_logger.dart';
+
+class UdpBroadcastSocketSet {
+  final List<RawDatagramSocket> _sockets;
+
+  const UdpBroadcastSocketSet._(this._sockets);
+
+  bool get isEmpty => _sockets.isEmpty;
+
+  Iterable<RawDatagramSocket> get sockets => _sockets;
+
+  void send(List<int> data, InternetAddress address, int port) {
+    for (final socket in _sockets) {
+      try {
+        socket.send(data, address, port);
+      } catch (e, st) {
+        appLogger.w('UDP broadcast send failed from ${socket.address.address}', error: e, stackTrace: st);
+      }
+    }
+  }
+
+  void close() {
+    for (final socket in _sockets) {
+      socket.close();
+    }
+  }
+}
+
+class UdpBroadcastSockets {
+  UdpBroadcastSockets._();
+
+  static final InternetAddress limitedBroadcastAddress = InternetAddress('255.255.255.255');
+
+  static Future<UdpBroadcastSocketSet> bind({int port = 0}) async {
+    final sockets = <RawDatagramSocket>[];
+    for (final address in await _localIPv4Addresses()) {
+      final socket = await _tryBind(address, port);
+      if (socket != null) sockets.add(socket);
+    }
+
+    if (sockets.isEmpty) {
+      final socket = await _tryBind(InternetAddress.anyIPv4, port);
+      if (socket != null) sockets.add(socket);
+    }
+
+    return UdpBroadcastSocketSet._(List.unmodifiable(sockets));
+  }
+
+  static Future<List<InternetAddress>> _localIPv4Addresses() async {
+    try {
+      final interfaces = await NetworkInterface.list(
+        includeLinkLocal: false,
+        includeLoopback: false,
+        type: InternetAddressType.IPv4,
+      );
+      final addresses = <InternetAddress>[];
+      final seen = <String>{};
+      for (final interface in interfaces) {
+        for (final address in interface.addresses) {
+          if (address.isLoopback || address.type != InternetAddressType.IPv4 || !seen.add(address.address)) continue;
+          addresses.add(address);
+        }
+      }
+      return List.unmodifiable(addresses);
+    } catch (e, st) {
+      appLogger.w('Failed to enumerate IPv4 interfaces for UDP broadcast', error: e, stackTrace: st);
+      return const [];
+    }
+  }
+
+  static Future<RawDatagramSocket?> _tryBind(InternetAddress address, int port) async {
+    try {
+      final socket = await RawDatagramSocket.bind(address, port);
+      socket.broadcastEnabled = true;
+      return socket;
+    } catch (e, st) {
+      appLogger.w('Failed to bind UDP broadcast socket on ${address.address}:$port', error: e, stackTrace: st);
+      return null;
+    }
+  }
+}