UPnP.cs

/*
Copyright (C) 2010-2013 David Mitchell

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

using System;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Xml;
//This upnp class comes from http://www.codeproject.com/Articles/27992/NAT-Traversal-with-UPnP-in-C, Modified for use with MCForge

namespace MCForge.Core {

    public sealed class UPnP {

        public static bool CanUseUpnp { get {return Discover(); } }

        private const string req = "M-SEARCH * HTTP/1.1\r\n" +
                                                            "HOST: 239.255.255.250:1900\r\n" +
                                                            "ST:upnp:rootdevice\r\n" +
                                                            "MAN:\"ssdp:discover\"\r\n" +
                                                            "MX:3\r\n\r\n";

        static TimeSpan _timeout = new TimeSpan(0, 0, 0, 3);
        public static TimeSpan TimeOut {
            get { return _timeout; }
            set { _timeout = value; }
        }
        static string _descUrl, _serviceUrl, _eventUrl;
        private static bool Discover() {
            Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
            byte[] data = Encoding.ASCII.GetBytes(req);
            IPEndPoint ipe = new IPEndPoint(IPAddress.Parse("239.255.255.250"), 1900);
            byte[] buffer = new byte[0x1000];

            DateTime start = DateTime.Now;
            try {
                do {
                    s.SendTo(data, ipe);
                    s.SendTo(data, ipe);
                    s.SendTo(data, ipe);

                    int length = -1;
                    do {
                        SocketError error;
                        s.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, out error, new AsyncCallback((result) => {
                            length = s.Receive(buffer);
                        }), null);
                        
                        while(length == -1){
                            if ((DateTime.Now - start).TotalSeconds > 10 ) {
                                return false;
                            }
                            Thread.Sleep(1000);
                        }

                        string resp = Encoding.ASCII.GetString(buffer, 0, length);
                        if (resp.Contains("upnp:rootdevice")) {
                            resp = resp.Substring(resp.ToLower().IndexOf("location:") + 9);
                            resp = resp.Substring(0, resp.IndexOf("\r")).Trim();
                            if (!string.IsNullOrEmpty(_serviceUrl = GetServiceUrl(resp))) {
                                _descUrl = resp;
                                return true;
                            }
                        }
                    } while (length > 0);
                } while (start.Subtract(DateTime.Now) < _timeout);
                return false;
            }
            catch {
                return false;
            }
        }

        private static string GetServiceUrl(string resp) {
#if !DEBUG
            try {
#endif
                XmlDocument desc = new XmlDocument();
                var request = WebRequest.CreateDefault(new Uri(resp));
                desc.Load(request.GetResponse().GetResponseStream());
                XmlNamespaceManager nsMgr = new XmlNamespaceManager(desc.NameTable);
                nsMgr.AddNamespace("tns", "urn:schemas-upnp-org:device-1-0");
                XmlNode typen = desc.SelectSingleNode("//tns:device/tns:deviceType/text()", nsMgr);
                if ( !typen.Value.Contains("InternetGatewayDevice") )
                    return null;
                XmlNode node = desc.SelectSingleNode("//tns:service[tns:serviceType=\"urn:schemas-upnp-org:service:WANIPConnection:1\"]/tns:controlURL/text()", nsMgr);
                if ( node == null )
                    return null;
                XmlNode eventnode = desc.SelectSingleNode("//tns:service[tns:serviceType=\"urn:schemas-upnp-org:service:WANIPConnection:1\"]/tns:eventSubURL/text()", nsMgr);
                _eventUrl = CombineUrls(resp, eventnode.Value);
                return CombineUrls(resp, node.Value);
#if !DEBUG
            }
            catch { return null; }
#endif
        }

        private static string CombineUrls(string resp, string p) {
            int n = resp.IndexOf("://");
            n = resp.IndexOf('/', n + 3);
            return resp.Substring(0, n) + p;
        }

        public static void ForwardPort(int port, ProtocolType protocol, string description) {
            if ( string.IsNullOrEmpty(_serviceUrl) )
                throw new Exception("No UPnP service available or Discover() has not been called");
            XmlDocument xdoc = SOAPRequest(_serviceUrl, "<u:AddPortMapping xmlns:u=\"urn:schemas-upnp-org:service:WANIPConnection:1\">" +
                "<NewRemoteHost></NewRemoteHost><NewExternalPort>" + port.ToString() + "</NewExternalPort><NewProtocol>" + protocol.ToString().ToUpper() + "</NewProtocol>" +
                "<NewInternalPort>" + port.ToString() + "</NewInternalPort><NewInternalClient>" + GetLocalIP() +
                "</NewInternalClient><NewEnabled>1</NewEnabled><NewPortMappingDescription>" + description +
            "</NewPortMappingDescription><NewLeaseDuration>0</NewLeaseDuration></u:AddPortMapping>", "AddPortMapping");
        }

        public static void DeleteForwardingRule(int port, ProtocolType protocol) {
            if ( string.IsNullOrEmpty(_serviceUrl) )
                throw new Exception("No UPnP service available or Discover() has not been called");
            XmlDocument xdoc = SOAPRequest(_serviceUrl,
            "<u:DeletePortMapping xmlns:u=\"urn:schemas-upnp-org:service:WANIPConnection:1\">" +
            "<NewRemoteHost>" +
            "</NewRemoteHost>" +
            "<NewExternalPort>" + port + "</NewExternalPort>" +
            "<NewProtocol>" + protocol.ToString().ToUpper() + "</NewProtocol>" +
            "</u:DeletePortMapping>", "DeletePortMapping");

        }

        [DebuggerStepThrough]
        public static IPAddress GetExternalIP() {
            if ( string.IsNullOrEmpty(_serviceUrl) )
                throw new Exception("No UPnP service available or Discover() has not been called");
            XmlDocument xdoc = SOAPRequest(_serviceUrl, "<u:GetExternalIPAddress xmlns:u=\"urn:schemas-upnp-org:service:WANIPConnection:1\">" +
            "</u:GetExternalIPAddress>", "GetExternalIPAddress");
            XmlNamespaceManager nsMgr = new XmlNamespaceManager(xdoc.NameTable);
            nsMgr.AddNamespace("tns", "urn:schemas-upnp-org:device-1-0");
            string IP = xdoc.SelectSingleNode("//NewExternalIPAddress/text()", nsMgr).Value;
            return IPAddress.Parse(IP);
        }

        [DebuggerStepThrough]
        public static string GetLocalIP() {
            IPHostEntry host;
            string localIP = "?";
            host = Dns.GetHostEntry(Dns.GetHostName());
            foreach ( IPAddress ip in host.AddressList ) {
                if ( ip.AddressFamily == AddressFamily.InterNetwork ) {
                    localIP = ip.ToString();
                }
            }
            return localIP;
        }

        private static XmlDocument SOAPRequest(string url, string soap, string function) {
            string req = "<?xml version=\"1.0\"?>" +
            "<s:Envelope xmlns:s=\"http://schemas.xmlsoap.org/soap/envelope/\" s:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\">" +
            "<s:Body>" +
            soap +
            "</s:Body>" +
            "</s:Envelope>";
            WebRequest r = HttpWebRequest.Create(url);
            r.Method = "POST";
            byte[] b = Encoding.UTF8.GetBytes(req);
            r.Headers.Add("SOAPACTION", "\"urn:schemas-upnp-org:service:WANIPConnection:1#" + function + "\"");
            r.ContentType = "text/xml; charset=\"utf-8\"";
            r.ContentLength = b.Length;
            r.GetRequestStream().Write(b, 0, b.Length);
            XmlDocument resp = new XmlDocument();
            WebResponse wres = r.GetResponse();
            Stream ress = wres.GetResponseStream();
            resp.Load(ress);
            return resp;
        }
    }
}