[C#] 포트 오픈 여부 확인

IP 주소로 PC에 해당 포트가 오픈되어 있는지 확인하는 C# 소스입니다.





using System;
using System.Text;
using System.Net.Sockets;
using System.Net.NetworkInformation;
using System.Net;


public class CheckPort
{

    public static void Main(string[] args)
    {
        try
        {
		if (args.Length < 1)
		{
			Console.WriteLine("Usage : CheckPort.exe [IP] [Port]");
			Console.WriteLine("        CheckPort.exe 192.168.0.1 80");
			return;
		}
		
		string ip = args[0];
		int port = Convert.ToInt32(args[1]);
		
		if (PingTest(ip))
		{
			Console.WriteLine("{0} PING OK", ip);
			
			if (ConnectTest(ip, port))
			{
				Console.WriteLine("{0}:{1} is open.", ip, port);
			}
			else
			{
				Console.WriteLine("{0}:{1} is closed.", ip, port);
			}
		}
		else
		{
			Console.WriteLine("{0} PING NG", ip);
		}
	}
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }

    }  
	
	
	
	private static bool PingTest(string ip)
	{
		bool result = false;
		try
		{
			Ping pp = new Ping();
			PingOptions po = new PingOptions();

			po.DontFragment = true;

			byte[] buf = Encoding.ASCII.GetBytes("aaaaaaaaaaaaaaaaaaaa");

			PingReply reply = pp.Send(
				IPAddress.Parse(ip),
				10, buf, po
			);

			if (reply.Status == IPStatus.Success)
			{
				result= true;
			}
			else
			{
				result = false;
			}
			return result;
		}
		catch
		{
			throw;
		}
	}


	private static bool ConnectTest(string ip, int port)
	{
		bool result = false;

		Socket socket = null;
		try
		{
			socket = new Socket(
				AddressFamily.InterNetwork,
				SocketType.Stream, 
				ProtocolType.Tcp
			);

			socket.SetSocketOption(
				SocketOptionLevel.Socket,
				SocketOptionName.DontLinger,
				false
			);


			IAsyncResult ret = socket.BeginConnect(ip, port, null, null);

			result = ret.AsyncWaitHandle.WaitOne(100, true);
		}
		catch { }
		finally
		{
			if (socket != null)
			{
				socket.Close();
			}
		}
		return result;
	}


}