MCGalaxy/GUI/UPnP.cs

/*
Copyright 2012 MCForge
Dual-licensed under the Educational Community License, Version 2.0 and
the GNU General Public License, Version 3 (the "Licenses"); you may
not use this file except in compliance with the Licenses. You may
obtain a copy of the Licenses at
https://opensource.org/license/ecl-2-0/
https://www.gnu.org/licenses/gpl-3.0.html
Unless required by applicable law or agreed to in writing,
software distributed under the Licenses are distributed on an "AS IS"
BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
or implied. See the Licenses for the specific language governing
permissions and limitations under the Licenses.
*/
using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Xml;
using MCGalaxy.Network;
//This upnp class comes from http://www.codeproject.com/Articles/27992/NAT-Traversal-with-UPnP-in-C, Modified for use with MCForge
// Some relatively straightforward documentation on how UPnP works:
//  http://www.upnp-hacks.org/upnp.html
//  http://www.upnp-hacks.org/igd.html

namespace MCGalaxy 
{
    public class UPnP
    {
        public static TimeSpan Timeout   = TimeSpan.FromSeconds(3);
        public const string TCP_PROTOCOL = "TCP";
        
        public Action<string> Log;
        
        const string SEARCH_REQUEST = 
            "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";

        string _serviceUrl;
        List<string> visitedLocations = new List<string>();
        
        
        public bool Discover() {
            Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
            
            byte[] data   = Encoding.ASCII.GetBytes(SEARCH_REQUEST);
            IPEndPoint ep = new IPEndPoint(IPAddress.Broadcast, 1900);
            byte[] buffer = new byte[0x1000];

            s.ReceiveTimeout = 3000;
            visitedLocations.Clear();
            Log("Searching for UPnP supporting routers..");
            DateTime end  = DateTime.UtcNow.Add(Timeout);
            
            try {
                while (DateTime.UtcNow < end)
                {
                    s.SendTo(data, ep);
                    s.SendTo(data, ep);
                    s.SendTo(data, ep);
                
                    int length = -1;
                    do {
                        length = s.Receive(buffer);
                        string resp = Encoding.ASCII.GetString(buffer, 0, length);
                        
                        if (resp.Contains("upnp:rootdevice")) {
                            string location = resp.Substring(resp.ToLower().IndexOf("location:") + 9);
                            location = location.Substring(0, location.IndexOf("\r")).Trim();
                            
                            if (!visitedLocations.Contains(location)) {
                                visitedLocations.Add(location);
                                //Log("Found UPnP device: " + location);
                                Log("  Found: " + location);
                                
                                _serviceUrl = GetServiceUrl(location);
                                if (String.IsNullOrEmpty(_serviceUrl)) continue;
                                
                                Log("  Service URL: " + _serviceUrl);
                                return true;
                            }
                        }
                    } while (length > 0);
                }
            } catch (Exception ex) {
                Logger.LogError("Error discovering UPnP devices", ex);
            }
            
            Log("No UPnP supporting routers found");
            return false;
        }

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

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

        static string GetServiceUrl(string location) {
            try {
                XmlDocument doc = new XmlDocument();
                WebRequest request = WebRequest.Create(location);
                doc.Load(request.GetResponse().GetResponseStream());
                
                XmlNamespaceManager nsMgr = new XmlNamespaceManager(doc.NameTable);
                nsMgr.AddNamespace("tns", "urn:schemas-upnp-org:device-1-0");
                XmlNode node;
                
                node = doc.SelectSingleNode("//tns:device/tns:deviceType/text()", nsMgr);                
                if (node == null || !node.Value.Contains("InternetGatewayDevice"))
                    return null;
                
                node = doc.SelectSingleNode("//tns:service[tns:serviceType=\"urn:schemas-upnp-org:service:WANIPConnection:1\"]/tns:controlURL/text()", nsMgr);
                if (node != null) return CombineUrls(location, node.Value);
                
                // Try again with version 2
                node = doc.SelectSingleNode("//tns:service[tns:serviceType=\"urn:schemas-upnp-org:service:WANIPConnection:2\"]/tns:controlURL/text()", nsMgr);
                if (node != null) return CombineUrls(location, node.Value);

            } catch (Exception ex) {
                HttpUtil.DisposeErrorResponse(ex);
                Logger.LogError("Error getting UPnP device service URL", ex);
            }
            return null;
        }

        static string CombineUrls(string location, string p) {
            int n = location.IndexOf("://");
            n = location.IndexOf('/', n + 3);
            return location.Substring(0, n) + p;
        }
        
        static string GetLocalIP() {
            IPHostEntry host = Dns.GetHostEntry(Dns.GetHostName());        
            foreach (IPAddress ip in host.AddressList) 
            {
                if (ip.AddressFamily == AddressFamily.InterNetwork) {
                    return ip.ToString();
                }
            }
            return "?";
        }        

        /// <summary> Performs a XML SOAP request </summary>
        /// <returns> XML response from the service </returns>
        static string SOAPRequest(string url, string function, string soap) {
            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 = WebRequest.Create(url);
            r.Method = "POST";            
            r.Headers.Add("SOAPACTION", "\"urn:schemas-upnp-org:service:WANIPConnection:1#" + function + "\"");
            r.ContentType = "text/xml; charset=\"utf-8\"";
            
            byte[] data = Encoding.UTF8.GetBytes(req);
            HttpUtil.SetRequestData(r, data);
            
            WebResponse res = r.GetResponse();
            return HttpUtil.GetResponseText(res);
        }
    }
}