Enhance peer traffic monitoring with tcpdump and detailed handshake capture

lib/services/protocol_blocking_service.dart

@@ -68,38 +68,105 @@ class ProtocolBlockingService {
   static Future<void> _scanForNewConnections() async {
     _scanCount++;
     
+    if (_activePeerIPs.isEmpty) {
+      return; // No peers to monitor
+    }
+    
     try {
-      // Monitor both TCP and UDP connections
-      final tcpResult = await Process.run('ss', ['-tnp']);
-      final udpResult = await Process.run('ss', ['-unp']);
+      // Monitor peer traffic directly using tcpdump on wg0 interface
+      await _monitorPeerTraffic();
       
-      if (_scanCount % 100 == 0) { // Log every 10 seconds
-        print('🔍 Scan #$_scanCount - TCP exit code: ${tcpResult.exitCode}, UDP exit code: ${udpResult.exitCode}');
-      }
-      
-      if (tcpResult.exitCode != 0) {
-        print('❌ TCP ss command failed: ${tcpResult.stderr}');
-        return;
-      }
-      if (udpResult.exitCode != 0) {
-        print('❌ UDP ss command failed: ${udpResult.stderr}');
-        return;
-      }
-      
-      final tcpConnections = _parseConnections(tcpResult.stdout.toString(), 'tcp');
-      final udpConnections = _parseConnections(udpResult.stdout.toString(), 'udp');
-      
-      if (_scanCount % 100 == 0 && _activePeerIPs.isNotEmpty) {
+      if (_scanCount % 100 == 0) {
         print('🔍 Monitoring ${_activePeerIPs.length} active peers: $_activePeerIPs');
       }
-      
-      for (final conn in [...tcpConnections, ...udpConnections]) {
-        if (_isNewConnection(conn) && _isPeerConnection(conn)) {
-          await _handleNewConnection(conn);
+    } catch (e) {
+      print('❌ Error monitoring peer traffic: $e');
     }
   }
+  
+  static Future<void> _monitorPeerTraffic() async {
+    for (final peerIP in _activePeerIPs) {
+      try {
+        // Capture any new outbound traffic from this peer
+        final process = await Process.start('timeout', [
+          '0.1', // Very short timeout - just check for new packets
+          'tcpdump',
+          '-i', 'wg0',
+          '-c', '1',
+          '-l', // Line buffered
+          'src $peerIP and (tcp[tcpflags] & tcp-syn != 0 or udp)',
+        ]);
+        
+        final output = <String>[];
+        await for (final data in process.stdout) {
+          output.add(String.fromCharCodes(data));
+        }
+        
+        final exitCode = await process.exitCode;
+        process.kill();
+        
+        if (exitCode == 0 && output.isNotEmpty) {
+          final packetData = output.join();
+          await _analyzeNewPacket(packetData, peerIP);
+        }
       } catch (e) {
-      print('❌ Error scanning for connections: $e');
+        // Ignore timeout errors - normal when no new packets
+        if (!e.toString().contains('timeout')) {
+          print('❌ Error monitoring peer $peerIP: $e');
+        }
+      }
+    }
+  }
+  
+  static Future<void> _analyzeNewPacket(String packetData, String peerIP) async {
+    if (_processedConnections.contains(packetData.hashCode.toString())) {
+      return; // Already processed this packet pattern
+    }
+    
+    _processedConnections.add(packetData.hashCode.toString());
+    
+    print('🔍 New peer traffic detected from $peerIP');
+    print('📡 Capturing detailed handshake...');
+    
+    // Now capture the full handshake with more detail
+    await _captureDetailedHandshake(peerIP, packetData);
+  }
+  
+  static Future<void> _captureDetailedHandshake(String peerIP, String initialPacket) async {
+    try {
+      final process = await Process.start('timeout', [
+        '2',
+        'tcpdump',
+        '-i', 'wg0',
+        '-c', '3', // Capture a few packets to get handshake
+        '-s', '200',
+        '-x',
+        'src $peerIP',
+      ]);
+      
+      final handshakeData = <String>[];
+      await for (final data in process.stdout) {
+        handshakeData.add(String.fromCharCodes(data));
+      }
+      
+      final exitCode = await process.exitCode;
+      process.kill();
+      
+      if (exitCode == 0 && handshakeData.isNotEmpty) {
+        final data = handshakeData.join();
+        print('✅ Handshake captured for peer $peerIP');
+        _analyzeHandshake(data, Connection(
+          protocol: 'unknown',
+          localIP: peerIP,
+          localPort: 0,
+          remoteIP: 'unknown',
+          remotePort: 0,
+        ));
+      } else {
+        print('⏱️  No additional handshake data captured for peer $peerIP');
+      }
+    } catch (e) {
+      print('❌ Error capturing detailed handshake: $e');
     }
   }