feat(network): VPN bypass — bind to non-VPN net (wlan*/rmnet*) when tun detected + dev toggle

2026-05-16 07:45:29 +03:00
parent 254afb1e95
commit 6e3cdc434d
5 changed files with 353 additions and 1 deletions
@@ -5,6 +5,7 @@ import 'dart:typed_data';
 import '../config/proxy_config.dart';
 import '../utils/logger.dart';
 import 'proxy_connector.dart';
+import 'vpn_bypass.dart';

 enum SocketState { disconnected, connecting, connected }

@@ -34,6 +35,12 @@ class Connection {
    _setState(SocketState.connecting);

    try {
+      try {
+        await VpnBypassService.instance.applyIfNeeded();
+      } catch (e) {
+        logger.w('VPN bypass: пропущено ($e)');
+      }
+
      final proxySettings = await ProxyConfig.load();
      RawSocket rawSocket;

@@ -0,0 +1,147 @@
+import 'dart:io';
+
+import 'package:flutter/services.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import '../utils/logger.dart';
+
+class VpnBypassResult {
+  final bool enabled;
+  final bool tunDetected;
+  final bool bound;
+  final String? boundInterface;
+  final String? transport;
+  final String? reason;
+
+  const VpnBypassResult({
+    required this.enabled,
+    this.tunDetected = false,
+    this.bound = false,
+    this.boundInterface,
+    this.transport,
+    this.reason,
+  });
+
+  @override
+  String toString() =>
+      'VpnBypassResult(enabled: $enabled, tun: $tunDetected, bound: $bound, '
+      'iface: $boundInterface, transport: $transport, reason: $reason)';
+}
+
+/// При активном VPN (tun-интерфейс) привязывает процесс к не-VPN сети
+/// (wlan*/rmnet*). Только Android, по умолчанию выключено.
+class VpnBypassService {
+  VpnBypassService._();
+  static final VpnBypassService instance = VpnBypassService._();
+
+  static const String prefKey = 'dev_vpn_bypass';
+
+  static const MethodChannel _channel =
+      MethodChannel('ru.komet.app/vpn_bypass');
+
+  bool _bound = false;
+
+  bool get _supported => Platform.isAndroid;
+
+  Future<bool> isEnabled() async {
+    final prefs = await SharedPreferences.getInstance();
+    return prefs.getBool(prefKey) ?? false;
+  }
+
+  Future<void> setEnabled(bool value) async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool(prefKey, value);
+  }
+
+  /// Вызывается перед каждым (ре)коннектом.
+  Future<VpnBypassResult> applyIfNeeded() async {
+    if (!_supported) {
+      return const VpnBypassResult(
+        enabled: false,
+        reason: 'unsupported_platform',
+      );
+    }
+
+    if (!await isEnabled()) {
+      await _restoreDefault();
+      return const VpnBypassResult(enabled: false);
+    }
+
+    final tunDetected = await _hasTunInterface();
+    if (!tunDetected) {
+      await _restoreDefault();
+      logger.i('VPN bypass: tun-интерфейс не найден — маршрут по умолчанию');
+      return const VpnBypassResult(enabled: true, tunDetected: false);
+    }
+
+    try {
+      final res = await _channel
+          .invokeMapMethod<String, dynamic>('bindToNonVpnNetwork');
+      final bound = res?['bound'] == true;
+      _bound = bound;
+      final result = VpnBypassResult(
+        enabled: true,
+        tunDetected: true,
+        bound: bound,
+        boundInterface: res?['interface'] as String?,
+        transport: res?['transport'] as String?,
+        reason: res?['reason'] as String?,
+      );
+      if (bound) {
+        logger.i(
+          'VPN bypass: трафик направлен мимо VPN → '
+          '${result.boundInterface} (${result.transport})',
+        );
+      } else {
+        logger.w('VPN bypass: не удалось обойти VPN (${result.reason})');
+      }
+      return result;
+    } on PlatformException catch (e) {
+      logger.e('VPN bypass: ошибка платформы: ${e.message}');
+      return VpnBypassResult(
+        enabled: true,
+        tunDetected: true,
+        reason: e.code,
+      );
+    } on MissingPluginException {
+      return const VpnBypassResult(
+        enabled: true,
+        tunDetected: true,
+        reason: 'no_plugin',
+      );
+    }
+  }
+
+  Future<bool> _hasTunInterface() async {
+    try {
+      final res = await _channel
+          .invokeMapMethod<String, dynamic>('detectInterfaces');
+      if (res != null && res.containsKey('hasTun')) {
+        return res['hasTun'] == true;
+      }
+    } catch (_) {}
+    try {
+      final ifaces = await NetworkInterface.list(
+        includeLoopback: false,
+        includeLinkLocal: true,
+      );
+      return ifaces.any((i) {
+        final n = i.name.toLowerCase();
+        return n.startsWith('tun') ||
+            n.startsWith('ppp') ||
+            n.startsWith('ipsec') ||
+            n.startsWith('wg');
+      });
+    } catch (_) {
+      return false;
+    }
+  }
+
+  Future<void> _restoreDefault() async {
+    if (!_bound) return;
+    try {
+      await _channel.invokeMethod('unbindNetwork');
+    } catch (_) {}
+    _bound = false;
+  }
+}