UDP packet capturing in c#

Question

Wireshark captures UDP packets in my LAN with follwoing details

Source IP            192.168.1.2
Destination IP      233.x.x.x
Source Port        24098
Destination Port      12074,12330

how can i capture it in c#?

Answer 1

Solved it myself

Here is my working code

class CAA
{

    private Socket UDPSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
    private IPAddress Target_IP;
    private int Target_Port;
    public static int bPause;

    public CAA()
    {
        Target_IP = IPAddress.Parse("x.x.x.x");
        Target_Port = xxx;

        try
        {
            IPEndPoint LocalHostIPEnd = new
            IPEndPoint(IPAddress.Any, Target_Port);
            UDPSocket.SetSocketOption(SocketOptionLevel.Udp, SocketOptionName.NoDelay, 1);
            UDPSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, 1);
            UDPSocket.Bind(LocalHostIPEnd);
            UDPSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.MulticastTimeToLive, 0);
            UDPSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership, new
            MulticastOption(Target_IP));
            Console.WriteLine("Starting Recieve");
            Recieve();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message + " " + e.StackTrace);
        }
    }

    private void Recieve()
    {
        try
        {
            IPEndPoint LocalIPEndPoint = new
            IPEndPoint(IPAddress.Any, Target_Port);
            EndPoint LocalEndPoint = (EndPoint)LocalIPEndPoint;
            StateObject state = new StateObject();
            state.workSocket = UDPSocket;
            Console.WriteLine("Begin Recieve");
            UDPSocket.BeginReceiveFrom(state.buffer, 0, state.BufferSize, 0, ref LocalEndPoint, new AsyncCallback(ReceiveCallback), state);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private void ReceiveCallback(IAsyncResult ar)
    {

            IPEndPoint LocalIPEndPoint = new
            IPEndPoint(IPAddress.Any, Target_Port);
            EndPoint LocalEndPoint = (EndPoint)LocalIPEndPoint;
            StateObject state = (StateObject)ar.AsyncState;
            Socket client = state.workSocket;
            int bytesRead = client.EndReceiveFrom(ar, ref LocalEndPoint);            



            client.BeginReceiveFrom(state.buffer, 0, state.BufferSize, 0, ref LocalEndPoint, new AsyncCallback(ReceiveCallback), state);
    }


    public static void Main()
    {       
        CAA o = new CAA();        
        Console.ReadLine();
    }

    public class StateObject
    {
        public int BufferSize = 512;
        public Socket workSocket;
        public byte[] buffer;

        public StateObject()
        {
            buffer = new byte[BufferSize];
        }
    }

}

Answer 2

The Winpcap library is one of the best ways to do this. I have experience in doing this in C# and it was really easy to work with this library.

This project shows how to do it with C#.