/src/Misc/ServerList.vala

using System;

using System.IO;

using System.Net;

using System.Net.NetworkInformation;

using System.Net.Sockets;

using Server;

using Server.Network;



namespace Server.Misc

{

	public class ServerList

	{

		/*

		 * The default setting for Address, a value of 'null', will use your local IP address. If all of your local IP addresses

		 * are private network addresses and AutoDetect is 'true' then RunUO will attempt to discover your public IP address

		 * for you automatically.

		 *

		 * If you do not plan on allowing clients outside of your LAN to connect, you can set AutoDetect to 'false' and leave

		 * Address set to 'null'.

		 *

		 * If your public IP address cannot be determined, you must change the value of Address to your public IP address

		 * manually to allow clients outside of your LAN to connect to your server. Address can be either an IP address or

		 * a hostname that will be resolved when RunUO starts.

		 *

		 * If you want players outside your LAN to be able to connect to your server and you are behind a router, you must also

		 * forward TCP port 2593 to your private IP address. The procedure for doing this varies by manufacturer but generally

		 * involves configuration of the router through your web browser.

		 *

		 * ServerList will direct connecting clients depending on both the address they are connecting from and the address and

		 * port they are connecting to. If it is determined that both ends of a connection are private IP addresses, ServerList

		 * will direct the client to the local private IP address. If a client is connecting to a local public IP address, they

		 * will be directed to whichever address and port they initially connected to. This allows multihomed servers to function

		 * properly and fully supports listening on multiple ports. If a client with a public IP address is connecting to a

		 * locally private address, the server will direct the client to either the AutoDetected IP address or the manually entered

		 * IP address or hostname, whichever is applicable. Loopback clients will be directed to loopback.

		 *

		 * If you would like to listen on additional ports (i.e. 22, 23, 80, for clients behind highly restrictive egress

		 * firewalls) or specific IP adddresses you can do so by modifying the file SocketOptions.cs found in this directory.

		 */



		public static readonly string Address = null;

		public static readonly string ServerName = "RunUO TC";



		public static readonly bool AutoDetect = true;



		public static void Initialize()

		{

			if ( Address == null ) {

				if ( AutoDetect )

					AutoDetection();

			}

			else {

				Resolve( Address, out m_PublicAddress );

			}



			EventSink.ServerList += new ServerListEventHandler( EventSink_ServerList );

		}



		private static IPAddress m_PublicAddress;



		private static void EventSink_ServerList( ServerListEventArgs e )

		{

			try

			{

				NetState ns = e.State;

				Socket s = ns.Socket;



				IPEndPoint ipep = (IPEndPoint)s.LocalEndPoint;



				IPAddress localAddress = ipep.Address;

				int localPort = ipep.Port;



				if ( IsPrivateNetwork( localAddress ) ) {

					ipep = (IPEndPoint)s.RemoteEndPoint;

					if ( !IsPrivateNetwork( ipep.Address ) && m_PublicAddress != null )

						localAddress = m_PublicAddress;

				}



				e.AddServer( ServerName, new IPEndPoint( localAddress, localPort ) );

			}

			catch

			{

				e.Rejected = true;

			}

		}



		private static void AutoDetection()

		{

			if ( !HasPublicIPAddress() ) {

				Console.Write( "ServerList: Auto-detecting public IP address..." );

				m_PublicAddress = FindPublicAddress();



				if ( m_PublicAddress != null )

					stdout.printf( "done ({0})", m_PublicAddress.ToString() );

				else

					stdout.printf( "failed" );

			}

		}



		private static void Resolve( string addr, out IPAddress outValue )

		{

			if ( IPAddress.TryParse( addr, out outValue ) )

				return;



			try {

				IPHostEntry iphe = Dns.GetHostEntry( addr );



				if ( iphe.AddressList.Length > 0 )

					outValue = iphe.AddressList[iphe.AddressList.Length - 1];

			}

			catch {

			}

		}



		private static bool HasPublicIPAddress()

		{

			NetworkInterface[] adapters = NetworkInterface.GetAllNetworkInterfaces();



			foreach ( NetworkInterface adapter in adapters ) {

				IPInterfaceProperties properties = adapter.GetIPProperties();



				foreach ( IPAddressInformation unicast in properties.UnicastAddresses ) {

					IPAddress ip = unicast.Address;



					if ( !IPAddress.IsLoopback( ip ) && ip.AddressFamily != AddressFamily.InterNetworkV6 && !IsPrivateNetwork( ip ) )

						return true;

				}

			}



			return false;





			/*

			IPHostEntry iphe = Dns.GetHostEntry( Dns.GetHostName() );



			IPAddress[] ips = iphe.AddressList;



			for ( int i = 0; i < ips.Length; ++i )

			{

				if ( ips[i].AddressFamily != AddressFamily.InterNetworkV6 && !IsPrivateNetwork( ips[i] ) )

					return true;

			}



			return false;

			*/

		}



		private static bool IsPrivateNetwork( IPAddress ip )

		{

			// 10.0.0.0/8

			// 172.16.0.0/12

			// 192.168.0.0/16



			if ( ip.AddressFamily == AddressFamily.InterNetworkV6 )

				return false;



			if ( Utility.IPMatch( "192.168.*", ip ) )

				return true;

			else if ( Utility.IPMatch( "10.*", ip ) )

				return true;

			else if ( Utility.IPMatch( "172.16-31.*", ip ) )

				return true;

			else

				return false;

		}



		private static IPAddress FindPublicAddress()

		{

			try {

				WebRequest req = HttpWebRequest.Create( "http://www.runuo.com/ip.php" );

				req.Timeout = 15000;



				WebResponse res = req.GetResponse();



				Stream s = res.GetResponseStream();



				StreamReader sr = new StreamReader( s );



				IPAddress ip = IPAddress.Parse( sr.ReadLine() );



				sr.Close();

				s.Close();

				res.Close();



				return ip;

			} catch {

				return null;

			}

		}

	}

}