Retry Udp Client : Udp Client : Network C# Source Code

    

/*
C# Network Programming 
by Richard Blum

Publisher: Sybex 
ISBN: 0782141765
*/
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

public class RetryUdpClient
{
   private byte[] data = new byte[1024];
   private static IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
   private static EndPoint Remote = (EndPoint)sender;

   private int SndRcvData(Socket s, byte[] message, EndPoint rmtdevice)
   {
      int recv;
      int retry = 0;

      while (true)
      {
         Console.WriteLine("Attempt #{0}", retry);
         try
         {
            s.SendTo(message, message.Length, SocketFlags.None, rmtdevice);
            data = new byte[1024];
            recv = s.ReceiveFrom(data, ref Remote);
         } catch (SocketException)
         {
            recv = 0;
         }

         if (recv > 0)
         {
            return recv;
         } else
         {
            retry++;
            if (retry > 4)
            {
               return 0;
            }
         }
      }
   }

   public RetryUdpClient()
   {
      string input, stringData;
      int recv;
      IPEndPoint ipep = new IPEndPoint(
                      IPAddress.Parse("127.0.0.1"), 9050);

      Socket server = new Socket(AddressFamily.InterNetwork,
                     SocketType.Dgram, ProtocolType.Udp);

      int sockopt = (int)server.GetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout);
      Console.WriteLine("Default timeout: {0}", sockopt);
      server.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, 3000);
      sockopt = (int)server.GetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout);
      Console.WriteLine("New timeout: {0}", sockopt);

      string welcome = "Hello, are you there?";
      data = Encoding.ASCII.GetBytes(welcome);

      recv = SndRcvData(server, data, ipep);
      if (recv > 0)
      {
         stringData = Encoding.ASCII.GetString(data, 0, recv);
         Console.WriteLine(stringData);
      } else
      {
         Console.WriteLine("Unable to communicate with remote host");
         return;
      }

      while(true)
      {
         input = Console.ReadLine();
         if (input == "exit")
            break;
         recv = SndRcvData(server, Encoding.ASCII.GetBytes(input), ipep);
         if (recv > 0)
         {
            stringData = Encoding.ASCII.GetString(data, 0, recv);
            Console.WriteLine(stringData);
         } else
            Console.WriteLine("Did not receive an answer");
      }
      Console.WriteLine("Stopping client");
      server.Close();
   }

   public static void Main()
   {
      RetryUdpClient ruc = new RetryUdpClient();
   }
}