UPnP.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Net.Sockets;
using System.Net;
using System.Net.NetworkInformation;
using System.Xml;
using System.IO;
using System.Linq;
using System.Web;
using System.Xml.Linq; // Be sure to set "Target framework:"  to non-client, e.g. framework 4.0.

namespace UPnP
{
    /// <summary>
    /// The Discovery class does the UDP broadcast and holds the Sonos topology info in various dictionaries.
    /// </summary>
    public class Discovery
    {
        // Discovery parameter that may need to be changed.
        static TimeSpan _timeout = new TimeSpan(0, 0, 0, 5); // fourth parameter is seconds
        static string _broadcastIP = "239.255.255.250";
        static int _broadcastPort = 1900;
        static string _searchTarget = "upnp:rootdevice";

        // Define properties and backing objects.
        public TimeSpan TimeOut
        { get { return _timeout; } set { _timeout = value; } }
        static public Dictionary<string, string> ZoneTable
        { get { return _zoneTable; } set { _zoneTable = value; } }
        static public Dictionary<string, string> ZoneTypes
        { get { return _zoneTypes; } set { _zoneTypes = value; } }
        static public Dictionary<string, string> ZoneIDs
        { get { return _zoneIDs; } set { _zoneIDs = value; } }
        static public Dictionary<string, bool> ZoneMasters
        { get { return _zoneMasters; } set { _zoneMasters = value; } }
        static public ArrayList Zones
        { get { return _zones; } set { _zones = value; } }

        static ArrayList _zones = new ArrayList();
        static Dictionary<string, string> _zoneTable = new Dictionary<string, string>();
        static Dictionary<string, string> _zoneTypes = new Dictionary<string, string>();
        static Dictionary<string, string> _zoneIDs = new Dictionary<string, string>();
        static Dictionary<string, bool> _zoneMasters = new Dictionary<string, bool>();

        /// <summary>
        /// Sends a UDP package over the specified broadcast IP and port and waits for responses.
        /// Some background: http://www.upnp-hacks.org/upnp.html, http://upnp.org/specs/arch/UPnP-arch-DeviceArchitecture-v1.0.pdf
        /// Refactored May 2016 Chris Fox, using code/structures from DeviceSpy - see http://www.meshcommander.com/upnptools
        /// </summary>
        /// 
        public void Discover()          // this cannot be a static class because it uses async callbacks
        {

            // create the discovery message to broadcast..
            HTTPMessage request = new HTTPMessage();
            IPEndPoint RemoteEP = new IPEndPoint(IPAddress.Parse(_broadcastIP), _broadcastPort);

            request.Directive = "M-SEARCH";
            request.DirectiveObj = "*";
            request.AddTag("ST", _searchTarget);
            request.AddTag("MX", "2");
            request.AddTag("MAN", "\"ssdp:discover\"");
            request.AddTag("HOST", RemoteEP.ToString()); // "239.255.255.250:1900"
            byte[] buffer = UTF8Encoding.UTF8.GetBytes(request.StringPacket);

            // get the local network interfaces... we will braodcast and receive responses on each interface we find...
            ArrayList AddressTable = new ArrayList();
            Hashtable Sessions = new Hashtable(); // used to keep track of reponses

            NetworkInterface[] interfaces = NetworkInterface.GetAllNetworkInterfaces();
            foreach (NetworkInterface i in interfaces)
            {
                if (i.IsReceiveOnly == false && i.OperationalStatus == OperationalStatus.Up && i.SupportsMulticast == true)
                {
                    IPInterfaceProperties i2 = i.GetIPProperties();
                    foreach (UnicastIPAddressInformation i3 in i2.UnicastAddresses)
                    {
                        if (!AddressTable.Contains(i3.Address) &&
                            !i3.Address.Equals(IPAddress.IPv6Loopback) &&
                            !i3.Address.Equals(IPAddress.Loopback))
                        {
                            AddressTable.Add(i3.Address);
                        }
                    }
                }
            }
            // AddressTable now contains a list of non-loopback network interfaces that are up
            //Now broadcast via each of them..

            foreach (IPAddress localaddr in AddressTable)
            {
                // set up a listener...
                // Look up in Sessions keyed by local addr - if not found, create and add
                UdpClient cl = (UdpClient)Sessions[localaddr];      // get previusly-used client
                if (cl == null)
                {
                    cl = new UdpClient(new IPEndPoint(localaddr, 0));   // make a new one - bound to local address and random port
                    cl.EnableBroadcast = true;
                    cl.BeginReceive(new AsyncCallback(OnReceive), cl);      // set up an async receive, pass in the UDP Client details
                    Sessions[localaddr] = cl;
                }

                if (RemoteEP.AddressFamily != cl.Client.AddressFamily) continue;
                if ((RemoteEP.AddressFamily == AddressFamily.InterNetworkV6) && ((IPEndPoint)cl.Client.LocalEndPoint).Address.IsIPv6LinkLocal == true && RemoteEP != OpenSource.UPnP.Utils.UpnpMulticastV6EndPoint2) continue;
                if ((RemoteEP.AddressFamily == AddressFamily.InterNetworkV6) && ((IPEndPoint)cl.Client.LocalEndPoint).Address.IsIPv6LinkLocal == false && RemoteEP != OpenSource.UPnP.Utils.UpnpMulticastV6EndPoint1) continue;

                IPEndPoint lep = (IPEndPoint)cl.Client.LocalEndPoint;
                if (cl.Client.AddressFamily == AddressFamily.InterNetwork)
                {
                    cl.Client.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.MulticastInterface, localaddr.GetAddressBytes());
                }
                else if (cl.Client.AddressFamily == AddressFamily.InterNetworkV6)
                {
                    cl.Client.SetSocketOption(SocketOptionLevel.IPv6, SocketOptionName.MulticastInterface, BitConverter.GetBytes((int)localaddr.ScopeId));
                }
                cl.Send(buffer, buffer.Length, RemoteEP);               // and do the broadcast

            }

            // now wait a little while for the replies to come back...

            System.Threading.Thread.Sleep(_timeout);
        }   // Discover

        public void OnReceive(IAsyncResult ar)
        // a reply has arrived...
        {
            UdpClient client = (UdpClient)ar.AsyncState;
            IPEndPoint ep = null;

            byte[] buf = client.EndReceive(ar, ref ep);     // get the response
            if (buf != null)
            {
                client.BeginReceive(new AsyncCallback(OnReceive), client);      // set up for another message to arrive
                try
                {
                    HTTPMessage msg = HTTPMessage.ParseByteArray(buf, 0, buf.Length);
                    // here filter to replies containing 'sonos' and add to zones..
                    if (msg.StringPacket.ToLower().Contains("sonos"))
                    {
                        string loc = msg.GetTag("Location");

                        if (!_zones.Contains(loc))
                        {
                            _zones.Add(loc);
                            _zoneTable.Add(loc, ""); // Will fill in zone friendly name later.
                        }
                    }
                }
                catch
                {
                    // a problem dealing with the reply message, so ignore it
                }
                return;
            }
        }       // OnReceive

    } // Dscovery

        /// <summary>
        /// The QueryDevice class does the following:
        /// 1. Queries (SOAP) zone attributes to get zone friendly name.
        /// 2. Queries (HTTP) zone player xml to get zone type and ID. 
        /// 3. Queries (SOAP) zone transports to see if zone is a master.
        /// 4. Queries (SOAP) zone content directory to get playlist list.
        /// 5. Queries (SOAP) zone content directory to get one playlist's content or a count of items.
        /// 6. 
        /// </summary>
        public static class QueryDevice
        {
            // Properties and backing objects.
            public static Dictionary<string, string> Playlists
            { get { return _playlists; } set { _playlists = value; } }
            public enum PlaylistAction { Count, Save };
            static public Dictionary<string, string> _playlists = new Dictionary<string, string>();
            static int _maxPlaylistPagingResults = 100;
            static int _maxPlaylistsReturned = 100;

            /// <summary>
            /// Get attributes for each zone in the Sonos topology.
            /// </summary>
            public static void QueryZoneAttributes()
            {
                if (UPnP.Discovery.ZoneTable.Count > 0)
                {
                    foreach (string zone in UPnP.Discovery.Zones)
                    {
                        // Query to get zone attributes.
                        string path = "/DeviceProperties/Control";
                        Uri uri = new Uri(zone);
                        string host = uri.Scheme + "://" + uri.Host + ":" + uri.Port.ToString();
                        string soapAction = "urn:upnp-org:serviceId:DeviceProperties#GetZoneAttributes";
                        string soapBody = "<u:GetZoneAttributes xmlns:u=\"urn:schemas-upnp-org:service:DeviceProperties:1\">" +
                                          "</u:GetZoneAttributes>";
                        XmlDocument resp = SOAPRequest(path, host, soapBody, soapAction);
                        string zoneName = resp.SelectSingleNode("//CurrentZoneName").InnerText;
                        UPnP.Discovery.ZoneTable[zone] = zoneName;
                    }
                }
            }

            /// <summary>
            /// Gets the zoneplayer xml file to read two pieces of information, the zone ID and type. We
            /// could use this xml to figure out the friendly name of the zone but we do that elsewhere.
            /// </summary>
            public static void QueryZonePlayerXml()
            {
                if (UPnP.Discovery.ZoneTable.Count > 0)
                {
                    foreach (string zone in UPnP.Discovery.Zones)
                    {
                        if (!UPnP.Discovery.ZoneTable[zone].ToLower().Contains("bridge"))
                        {
                            string path = "/xml/device_description.xml"; //  "/xml/zone_player.xml";
                            Uri uri = new Uri(zone);
                            string host = uri.Scheme + "://" + uri.Host + ":" + uri.Port.ToString();
                            XmlDocument resp = GetWebResponse(path, host);

                            XmlNamespaceManager nsm = new XmlNamespaceManager(resp.NameTable);
                            nsm.AddNamespace("zp", "urn:schemas-upnp-org:device-1-0");
                            string zoneType = resp.SelectSingleNode("//zp:modelNumber", nsm).InnerText;
                            UPnP.Discovery.ZoneTypes[zone] = zoneType;
                            string uuid = resp.SelectSingleNode("//zp:UDN", nsm).InnerText;
                            UPnP.Discovery.ZoneIDs[zone] = uuid.Substring(5, uuid.Length - 5); // need to remove uuid:
                        }
                        else
                        {
                            UPnP.Discovery.ZoneIDs[zone] = "....";
                            UPnP.Discovery.ZoneTypes[zone] = "ZoneBridge";
                        }
                    }
                }
            }

            /// <summary>
            /// Iterates through zones and figures out if the zone is a master.
            /// </summary>
            public static void FindMasters()
            {
                if (UPnP.Discovery.ZoneTable.Count > 0)
                {
                    foreach (string zone in UPnP.Discovery.Zones)
                    {
                        if (!UPnP.Discovery.ZoneTable[zone].ToLower().Contains("bridge"))
                        {
                            try
                            {
                                string path = "/MediaRenderer/AVTransport/Control";
                                Uri uri = new Uri(zone);
                                string host = uri.Scheme + "://" + uri.Host + ":" + uri.Port.ToString();
                                string soapAction = "uurn:schemas-upnp-org:service:AVTransport:1#GetPositionInfo";
                                string soapBody = "<u:GetPositionInfo xmlns:u=\"urn:schemas-upnp-org:service:AVTransport:1\">" +
                                                      "<InstanceID>0</InstanceID>" +
                                                      "<Channel>Master</Channel>" +
                                                  "</u:GetPositionInfo>";
                                XmlDocument resp = SOAPRequest(path, host, soapBody, soapAction);

                                string trackURI = resp.SelectSingleNode("//TrackURI").InnerText;
                                // check SOAP for TrackURI for x-rincon:RINCON
                                UPnP.Discovery.ZoneMasters[zone] = (!trackURI.StartsWith("x-rincon:RINCON") | trackURI == String.Empty);
                            }
                            catch (Exception e)
                            {
                                // It was reported that some devices throw an error as reported by a reader, adding try to catch this.
                                // Currently set message but don't use it. Consider surfacing in .xaml
                                string err = e.Message;
                                UPnP.Discovery.ZoneMasters[zone] = false;
                            }
                        }
                        else
                        {
                            UPnP.Discovery.ZoneMasters[zone] = false;
                        }
                    }
                }

            }

            /// <summary>
            /// Gets all playlists defined for the Sonos topology.
            /// </summary>
            public static void GetPlaylists()
            {
                if (UPnP.Discovery.Zones.Count > 0)
                {
                    string zone = UPnP.Discovery.Zones[0].ToString(); // use first in list if it isn't a bridge
                    if (UPnP.Discovery.ZoneTable[zone].ToLower().Contains("bridge"))
                    {
                        zone = UPnP.Discovery.Zones[1].ToString(); // use second
                    }
                    string path = "/MediaServer/ContentDirectory/Control";
                    Uri uri = new Uri(zone);
                    string host = uri.Scheme + "://" + uri.Host + ":" + uri.Port.ToString();
                    string soapAction = "urn:schemas-upnp-org:service:ContentDirectory:1#Browse";
                    string soapBody = "<u:Browse xmlns:u=\"urn:schemas-upnp-org:service:ContentDirectory:1\">" +
                                          "<ObjectID>SQ:</ObjectID>" +
                                          "<BrowseFlag>BrowseDirectChildren</BrowseFlag>" +
                                          "<Filter></Filter>" +
                                          "<StartingIndex>0</StartingIndex>" +
                                          "<RequestedCount>" + _maxPlaylistsReturned.ToString() + "</RequestedCount>" +
                                          "<SortCriteria></SortCriteria>" +
                                       "</u:Browse>";
                    XmlDocument resp = SOAPRequest(path, host, soapBody, soapAction);

                    XmlNamespaceManager nsm = new XmlNamespaceManager(resp.NameTable);
                    nsm.AddNamespace("dc", "http://purl.org/dc/elements/1.1/");
                    XmlDocument resultNode = new XmlDocument();
                    resultNode.LoadXml(resp.SelectSingleNode("*//Result").InnerText);
                    XmlNodeList playlists = resultNode.SelectNodes("//dc:title", nsm);
                    foreach (XmlNode xn in playlists)
                    {
                        string id = xn.ParentNode.Attributes["id"].Value;
                        if (!_playlists.ContainsKey(id))
                        {
                            _playlists.Add(id, xn.InnerText);
                        }
                    }
                }

            }

            /// <summary>
            /// Gets a playlist.
            /// </summary>
            /// <param name="playlistID">The playlist ID in the system, like "SQ:14" - for Saved Queue.</param>
            /// <param name="action">What to find out about the playlist, either return the items in the playlist or a count of the items.</param>
            /// <returns></returns>
            public static string GetPlaylist(string playlistID, PlaylistAction action, int index)
            {
                string zone = UPnP.Discovery.Zones[0].ToString(); // use first in list
                string path = "/MediaServer/ContentDirectory/Control";
                string numResults = String.Empty;
                string retVal = String.Empty;

                Uri uri = new Uri(zone);
                string host = uri.Scheme + "://" + uri.Host + ":" + uri.Port.ToString();
                string soapAction = "urn:schemas-upnp-org:service:ContentDirectory:1#Browse";
                string soapBody = "<u:Browse xmlns:u=\"urn:schemas-upnp-org:service:ContentDirectory:1\">" +
                                       "<ObjectID>" + playlistID + "</ObjectID>" +
                                       "<BrowseFlag>BrowseDirectChildren</BrowseFlag>" +
                                       "<Filter></Filter>" +
                                       "<StartingIndex>" + (_maxPlaylistPagingResults * (index)).ToString() + "</StartingIndex>" +
                                       "<RequestedCount>" + (_maxPlaylistPagingResults).ToString() + "</RequestedCount>" +
                                       "<SortCriteria></SortCriteria>" +
                                   "</u:Browse>";
                XmlDocument resp = SOAPRequest(path, host, soapBody, soapAction);

                XmlNamespaceManager nsm = new XmlNamespaceManager(resp.NameTable);
                nsm.AddNamespace("dc", "http://purl.org/dc/elements/1.1/");
                XmlDocument resultNode = new XmlDocument();
                numResults = resp.SelectSingleNode("*//TotalMatches").InnerText;
                switch (action)
                {
                    default:
                    case PlaylistAction.Count:
                        retVal = numResults;
                        break;
                    case PlaylistAction.Save:
                        if (Int32.Parse(numResults) > _maxPlaylistPagingResults * (index + 1) /* zero-based index */)
                        {
                            index += 1;
                            // Get playlist items recursively.
                            XDocument recurVal = XDocument.Parse(GetPlaylist(playlistID, action, index));
                            XDocument currVal = XDocument.Parse(resp.SelectSingleNode("*//Result").InnerText);
                            currVal.Root.Add(recurVal.Root.Elements());
                            retVal = currVal.ToString();
                        }
                        else
                        {
                            retVal = resp.SelectSingleNode("*//Result").InnerText;
                        }
                        break;
                }
                return retVal;
            }

            public static string CreateM3UPlaylist(string content)
            {
                StringBuilder sb = new StringBuilder();
                sb.Append("#EXTM3U");
                sb.Append(System.Environment.NewLine);
                sb.Append(System.Environment.NewLine);

                // Then we iterate through the DIDL xml item by item
                string DIDLTemplate = "<DIDL-Lite xmlns:dc=\"http://purl.org/dc/elements/1.1/\" " +
                                        "xmlns:upnp=\"urn:schemas-upnp-org:metadata-1-0/upnp/\" " +
                                        "xmlns:r=\"urn:schemas-rinconnetworks-com:metadata-1-0/\" " +
                                        "xmlns=\"urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/\">{0}" +
                                       "</DIDL-Lite>";
                int musicTracksSent = 0;
                XmlDocument DIDLXml = new XmlDocument();
                DIDLXml.LoadXml(SanitizeXmlString(content));
                XmlNamespaceManager nsm = new XmlNamespaceManager(DIDLXml.NameTable);
                nsm.AddNamespace("didl", "urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/");
                nsm.AddNamespace("dc", "http://purl.org/dc/elements/1.1/"); // not required for below currently
                nsm.AddNamespace("upnp", "urn:schemas-upnp-org:metadata-1-0/upnp/"); // not required for below currently
                XmlNodeList nl = DIDLXml.SelectNodes("//didl:item", nsm);
                foreach (XmlNode node in nl)
                {
                    string location = node.SelectSingleNode("didl:res", nsm).InnerText;
                    location = location.Remove(0, 12); // Remove x-file-cifs:
                    location = HttpUtility.UrlDecode(location);
                    string name = node.SelectSingleNode("dc:title", nsm).InnerText;
                    string creator = "";
                    if (node.SelectSingleNode("dc:creator", nsm) != null)
                    {
                        creator = node.SelectSingleNode("dc:creator", nsm).InnerText;
                    }
                    string oneItemDIDL = HttpUtility.HtmlEncode(String.Format(DIDLTemplate, node.OuterXml));
                    //oneItemDIDL = System.Security.SecurityElement.Escape(oneItemDIDL);
                    sb.Append("#EXTINF:0," + creator + " - " + name);
                    sb.Append(System.Environment.NewLine);
                    sb.Append(location.Replace("/", "\\"));
                    sb.Append(System.Environment.NewLine);
                    sb.Append(System.Environment.NewLine);

                    musicTracksSent += 1;
                    // Report on items written?
                }
                return sb.ToString();
            }

            /// <summary>
            /// Imports playlist content from a string into a master controller queue.
            /// </summary>
            /// <param name="content">The XML string that represents the playlist.</param>
            /// <param name="masterZoneAddress">The master zone address, like "192.168.2.5"</param>
            /// <param name="name">The name to give the playlist.</param>
            public static void ImportPlaylist(string content, string masterZoneAddress, string name)
            {
                // First we clear items in the queue
                string path = "/MediaRenderer/AVTransport/Control";
                string host = "http://" + masterZoneAddress + ":1400";
                string soapAction = "urn:schemas-upnp-org:service:AVTransport:1#RemoveAllTracksFromQueue";
                string soapBody = "<u:RemoveAllTracksFromQueue xmlns:u=\"urn:schemas-upnp-org:service:AVTransport:1\">" +
                                       "<InstanceID>0</InstanceID>" +
                                   "</u:RemoveAllTracksFromQueue>";
                XmlDocument resp = SOAPRequest(path, host, soapBody, soapAction);

                // Then we iterate through the DIDL xml item by item
                string DIDLTemplate = "<DIDL-Lite xmlns:dc=\"http://purl.org/dc/elements/1.1/\" " +
                                        "xmlns:upnp=\"urn:schemas-upnp-org:metadata-1-0/upnp/\" " +
                                        "xmlns:r=\"urn:schemas-rinconnetworks-com:metadata-1-0/\" " +
                                        "xmlns=\"urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/\">{0}" +
                                       "</DIDL-Lite>";
                int musicTracksSent = 0;
                XmlDocument DIDLXml = new XmlDocument();
                DIDLXml.LoadXml(SanitizeXmlString(content));
                XmlNamespaceManager nsm = new XmlNamespaceManager(DIDLXml.NameTable);
                nsm.AddNamespace("didl", "urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/");
                nsm.AddNamespace("dc", "http://purl.org/dc/elements/1.1/"); // not required for below currently
                nsm.AddNamespace("upnp", "urn:schemas-upnp-org:metadata-1-0/upnp/"); // not required for below currently
                XmlNodeList nl = DIDLXml.SelectNodes("//didl:item", nsm);
                foreach (XmlNode node in nl)
                {
                    // Create a command
                    string protocol = node.SelectSingleNode("didl:res", nsm).InnerText;
                    string oneItemDIDL = HttpUtility.HtmlEncode(String.Format(DIDLTemplate, node.OuterXml));
                    //oneItemDIDL = System.Security.SecurityElement.Escape(oneItemDIDL);
                    string title = name;

                    // Now put the element in the queue
                    soapAction = "urn:schemas-upnp-org:service:AVTransport:1#AddURIToQueue";
                    soapBody = "<u:AddURIToQueue xmlns:u=\"urn:schemas-upnp-org:service:AVTransport:1\">" +
                                   "<InstanceID>0</InstanceID>" +
                                   "<EnqueuedURI>" + protocol + "</EnqueuedURI>" +
                                   "<EnqueuedURIMetaData>" + oneItemDIDL + "</EnqueuedURIMetaData>" +
                                   "<DesiredFirstTrackNumberEnqueued>0</DesiredFirstTrackNumberEnqueued>" +
                                   "<EnqueueAsNext>0</EnqueueAsNext>" +
                                "</u:AddURIToQueue>";
                    resp = SOAPRequest(path, host, soapBody, soapAction);
                    musicTracksSent += 1;
                    // Process return parameters to provide info about has been put into queue?
                }
                if (musicTracksSent > 0)
                {
                    // At least one thing was written so try to save. If program exits before this point then items
                    // are in queue in master zone and can be manually saved.
                    name = name.Substring(0, Math.Min(20, name.Length)); // Limit on playlist length.
                    soapAction = "urn:schemas-upnp-org:service:AVTransport:1#SaveQueue";
                    soapBody = "<u:SaveQueue xmlns:u=\"urn:schemas-upnp-org:service:AVTransport:1\">" +
                                   "<InstanceID>0</InstanceID>" +
                                   "<Title>" + name + "</Title>" +
                                   "<ObjectID></ObjectID>" +
                               "</u:SaveQueue>";
                    resp = SOAPRequest(path, host, soapBody, soapAction);
                }

            }

            /// <summary>
            /// Gets the response to an HTTP request.
            /// </summary>
            /// <param name="path">URL path, like "/xml/zoneplayer.xml"</param>
            /// <param name="host">Host, like "192.168.2.5"</param>
            /// <returns></returns>
            private static XmlDocument GetWebResponse(string path, string host)
            {
                HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(host + path);
                webReq.Method = "GET";

                //Get the response handle, no response yet.
                HttpWebResponse webResp = (HttpWebResponse)webReq.GetResponse();

                //Get response
                Stream strm = webResp.GetResponseStream();
                StreamReader strmReader = new StreamReader(strm);
                string data = strmReader.ReadToEnd();
                XmlDocument resp = new XmlDocument();
                resp.LoadXml(SanitizeXmlString(data));
                strmReader.Close();
                strm.Close();
                webResp.Close();
                return resp;
            }

            /// <summary>
            /// Gets the response to a HTTP request with SOAP body.
            /// </summary>
            /// <param name="path">URL path, like "/MediaRenderer/AVTransport/Control"</param>
            /// <param name="host">Host, like "192.168.2.5"</param>
            /// <param name="soapBody">The SOAP envelope containing the parameters of the request.</param>
            /// <param name="soapAction">The SOAP action, like "Browse" or "SaveQueue".</param>
            /// <returns></returns>
            private static XmlDocument SOAPRequest(string path, string host, string soapBody, string soapAction)
            {
                string reqBody = "<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
                "<s:Envelope xmlns:s=\"http://schemas.xmlsoap.org/soap/envelope/\" s:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\">" +
                "<s:Body>" +
                soapBody +
                "</s:Body>" +
                "</s:Envelope>";
                HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(host + path);
                webReq.Method = "POST";
                byte[] buffer = Encoding.UTF8.GetBytes(reqBody);
                webReq.Headers.Add("SOAPACTION", "\"" + soapAction + "\"");
                webReq.ContentType = "text/xml; charset=\"utf-8\"";
                webReq.ContentLength = reqBody.Length;

                // Open  a stream for writing. Close.
                Stream postData = webReq.GetRequestStream();
                postData.Write(buffer, 0, buffer.Length);
                postData.Close();

                //Get the response handle, no response yet.
                HttpWebResponse webResp = (HttpWebResponse)webReq.GetResponse();

                //Get response
                int contentLength = (int)webResp.ContentLength;

                // CF160509 - if the response doesn't set the ContentLength header,  the value will be -1
                // So just read the stream to the end

                //char[] data = new char[contentLength];

                Stream strm = webResp.GetResponseStream();
                StreamReader strmReader = new StreamReader(strm);



                //int chunkSize = 256;
                //if (contentLength <= chunkSize)
                //{
                //    strmReader.Read(data, 0, contentLength);
                //}
                //else
                //{
                //    int count = strmReader.Read(data, 0, chunkSize);
                //    int indx = count;
                //    while (count > 0)
                //    {
                //        int inc = (contentLength - chunkSize) >= indx ? chunkSize : contentLength - indx;
                //        count = strmReader.Read(data, indx, inc);
                //        indx += count;
                //    }
                //}

                XmlDocument resp = new XmlDocument();
                //resp.LoadXml("<root>" + SanitizeXmlString(new String(data)) + "</root>");
                resp.LoadXml("<root>" + SanitizeXmlString(strmReader.ReadToEnd()) + "</root>");
                strmReader.Close();
                strm.Close();
                webResp.Close();
                return resp;
            }

            /// <summary>
            /// Removes junk from an XML string that doesn't belong there.
            /// Source: http://seattlesoftware.wordpress.com/2008/09/11/hexadecimal-value-0-is-an-invalid-character/
            /// Would be best to follow advice in link and build functionality into StreamReader.
            /// </summary>
            /// <param name="xml">XML to check.</param>
            /// <returns></returns>
            public static string SanitizeXmlString(string xml)
            {
                if (xml == null)
                {
                    throw new ArgumentNullException("xml");
                }
                StringBuilder buffer = new StringBuilder(xml.Length);

                foreach (char c in xml)
                {
                    if (XmlConvert.IsXmlChar(c))
                    {
                        buffer.Append(c);
                    }
                }
                return buffer.ToString();
            }
        }
    }