// File name:ipendpoint.cs.



// <Internal>

// This program contains snippets applicable to the following:

// System.Net.IPEndPoint (Snippet1);

// System.Net.IPEndPoint.IPEndPoint(IPAddress, int) (Snippet2);

// System.Net.IPEndPoint.Address (Snippet3);

// System.Net.IPEndPoint.AddressFamily (Snippet3);

// System.Net.IPEndPoint.Port (Snippet3);

// System.Net.IPEndPoint.Serialize (Snippet4);

// System.Net.IPEndPoint.Create (Snippet5);

// </Internal>



//<Snippet1>



// This example uses the IPEndPoint class and its members to display the home page

// of the server selected by the user.



using System;

using System.Text;

using System.IO;

using System.Net;

using System.Net.Sockets;

using System.Text.RegularExpressions;



namespace Mssc.Services.ConnectionManagement

{

  public class TestIPEndPoint

  {



    // The getPage method gets the server's home page content by

    // recreating the server's endpoint from the original serialized endpoint.

    // Then it creates a new socket and connects it to the endpoint.

    private static string getPage(string server, SocketAddress socketAddress)

    {

      //Set up variables and string to write to the server.

      Encoding ASCII = Encoding.ASCII;

      string Get = "GET / HTTP/1.1\r\nHost: " + server +

        "\r\nConnection: Close\r\n\r\n";

      Byte[] ByteGet = ASCII.GetBytes(Get);

      Byte[] RecvBytes = new Byte[256];

      String strRetPage = null;



      Socket socket = null;



//<Snippet5>

      // Recreate the connection endpoint from the serialized information.

      IPEndPoint endpoint = new IPEndPoint(0,0);

      IPEndPoint clonedIPEndPoint = (IPEndPoint) endpoint.Create(socketAddress);

      Console.WriteLine("clonedIPEndPoint: " + clonedIPEndPoint.ToString());

//</Snippet5>



      Console.WriteLine("Press any key to continue.");

      Console.ReadLine();



      try

      {

        // Create a socket object to establish a connection with the server.

        socket =

          new Socket(endpoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);



        // Connect to the cloned end point.

        socket.Connect(clonedIPEndPoint);

      }

      catch(SocketException e)

      {

        Console.WriteLine("Source : " + e.Source);

        Console.WriteLine("Message : " + e.Message);

      }

      catch(Exception e)

      {

        Console.WriteLine("Source : " + e.Source);

        Console.WriteLine("Message : " + e.Message);

      }



      if (socket == null)

        return ("Connection to cloned endpoint failed");



      // Send request to the server.

      socket.Send(ByteGet, ByteGet.Length, 0);



      // Receive the server  home page content.

      Int32 bytes = socket.Receive(RecvBytes, RecvBytes.Length, 0);



      // Read the first 256 bytes.

      strRetPage = "Default HTML page on " + server + ":\r\n";

      strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes);



      while (bytes > 0)

      {

        bytes = socket.Receive(RecvBytes, RecvBytes.Length, 0);

        strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes);

      }



      socket.Close();



      return strRetPage;

    }



//<Snippet4>

    // The serializeEndpoint method serializes the endpoint and returns the

    // SocketAddress containing the serialized endpoint data.

    private static SocketAddress serializeEndpoint(IPEndPoint endpoint)

    {



      // Serialize IPEndPoint details to a SocketAddress instance.

      SocketAddress socketAddress = endpoint.Serialize();



      // Display the serialized endpoint information.

      Console.WriteLine("Endpoint.Serialize() : " + socketAddress.ToString());



      Console.WriteLine("Socket.Family : " + socketAddress.Family);

      Console.WriteLine("Socket.Size : " + socketAddress.Size);



      Console.WriteLine("Press any key to continue.");

      Console.ReadLine();



      return socketAddress;

    }

//</Snippet4>



//<Snippet3>

    private static void displayEndpointInfo(IPEndPoint endpoint)

    {

      Console.WriteLine("Endpoint.Address : " + endpoint.Address);

      Console.WriteLine("Endpoint.AddressFamily : " + endpoint.AddressFamily);

      Console.WriteLine("Endpoint.Port : " + endpoint.Port);

      Console.WriteLine("Endpoint.ToString() : " + endpoint.ToString());



      Console.WriteLine("Press any key to continue.");

      Console.ReadLine();

    }

//</Snippet3>



    // The serializeEndpoint method determines the server endpoint and then

    // serializes it to obtain the related SocketAddress object.

    // Note that in the for loop a temporary socket is created to ensure that

    // the current IP address format matches the AddressFamily type.

    // In fact, in the case of servers supporting both IPv4 and IPv6, an exception

    // may arise if an IP address format does not match the address family type.

    private static SocketAddress getSocketAddress(string server, int port)

    {

      Socket tempSocket = null;

      IPHostEntry host = null;

      SocketAddress serializedSocketAddress = null;



      try

      {

        // Get the object containing Internet host information.

        host = Dns.Resolve(server);



// <Snippet2>

        // Obtain the IP address from the list of IP addresses associated with the server.

        foreach(IPAddress address in host.AddressList)

        {

          IPEndPoint endpoint = new IPEndPoint(address, port);



          tempSocket =

            new Socket(endpoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);



          tempSocket.Connect(endpoint);



          if(tempSocket.Connected)

          {

            // Display the endpoint information.

            displayEndpointInfo(endpoint);

            // Serialize the endpoint to obtain a SocketAddress object.

            serializedSocketAddress = serializeEndpoint(endpoint);

            break;

          }

          else

                    {

                        continue;

                    }

                }

// </Snippet2>



        // Close the temporary socket.

        tempSocket.Close();

      }



      catch(SocketException e)

      {

        Console.WriteLine("Source : " + e.Source);

        Console.WriteLine("Message : " + e.Message);

      }

      catch(Exception e)

      {

        Console.WriteLine("Source : " + e.Source);

        Console.WriteLine("Message : " + e.Message);

      }

      return serializedSocketAddress;

    }



    // The requestServerHomePage method obtains the server's home page and returns

    // its content.

    private static string requestServerHomePage(string server, int port)

    {

      String strRetPage = null;



      // Get a socket address using the specified server and port.

      SocketAddress socketAddress = getSocketAddress(server, port);



      if (socketAddress == null)

        strRetPage = "Connection failed";

      else

        // Obtain the server's home page content.

        strRetPage = getPage(server, socketAddress);



      return strRetPage;

    }



    // Show to the user how to use this program when wrong input parameters are entered.

    private static void showUsage()

    {

      Console.WriteLine("Enter the server name as follows:");

      Console.WriteLine("\tcs_ipendpoint servername");

    }



    // This is the program entry point. It allows the user to enter

    // a server name that is used to locate its current homepage.

    public static void Main(string[] args)

    {

      string host= null;

      int port = 80;



      // Define a regular expression to parse user's input.

      // This is a security check. It allows only

      // alphanumeric input string between 2 to 40 character long.

      Regex rex = new Regex(@"^[a-zA-Z]\w{1,39}$");



      if (args.Length < 1)

            {

                showUsage();

            }

            else

      {

        string message = args[0];

        if ((rex.Match(message)).Success)

        {

          host = args[0];

          // Get the specified server home_page and display its content.

          string result = requestServerHomePage(host, port);

          Console.WriteLine(result);

        }

        else

                {

                    Console.WriteLine("Input string format not allowed.");

                }

            }

    }

  }

}

//</Snippet1>