/sipsorcery-xmpp/SIPSorcery.XMPP/XMPPPhoneSession.cs

//-----------------------------------------------------------------------------

// Filename: XMPPPhoneSession.cs

//

// Description: Represents the an XMPP session that operates on top of an authenticated

// XMPP stream and that negotiates a voice call.

// 

// History:

// 13 Dec 2010	Aaron Clauson	Created.

//

// License: 

// This software is licensed under the BSD License http://www.opensource.org/licenses/bsd-license.php

//

// Copyright (c) 2010 Aaron Clauson (aaron@sipsorcery.com), Hobart, Tasmania, Australia (www.sipsorcery.com)

// All rights reserved.

//

// Redistribution and use in source and binary forms, with or without modification, are permitted provided that 

// the following conditions are met:

//

// Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 

// Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following 

// disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of SIP Sorcery. 

// nor the names of its contributors may be used to endorse or promote products derived from this software without specific 

// prior written permission. 

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, 

// BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 

// IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 

// OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 

// OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 

// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 

// POSSIBILITY OF SUCH DAMAGE.

//-----------------------------------------------------------------------------



using System;

using System.Collections.Generic;

using System.Linq;

using System.Xml.Linq;

using System.Text;

using SIPSorcery.Net;

using SIPSorcery.Sys;

using log4net;



namespace SIPSorcery.XMPP

{

    public class XMPPPhoneSession

    {

        private static ILog logger = AppState.logger;



        private static XNamespace m_sessionNS = XMPPStream.GOOGLE_SESSION_NAMESPACE;

        private static XNamespace m_phoneNS = XMPPStream.GOOGLE_PHONE_SESSION_NAMESPACE;

        private static XNamespace m_transportNS = XMPPStream.TRANSPORT_NAMESPACE;

        protected static XNamespace JabberClientNS = XMPPStream.JABBER_NAMESPACE;



        private string m_destination;

        private SDP m_sdp;

        private string m_jid;

        private XMPPAuthenticatedStream m_xmppStream;

        private string m_sessionID;



        // IQ id's.

        private string m_descriptionID;



        // Call response.

        private string m_remoteIPAddress;

        private int m_remotePort;

        private string m_remoteUsername;

        private string m_remotePassword;

        private List<XElement> m_payloads;



        public Action<SDP> Accepted;

        public Action Rejected;

        public Action Hungup;



        public XMPPPhoneSession(string jid, XMPPAuthenticatedStream xmppStream)

        {

            m_sessionID = Crypto.GetRandomString(6);

            m_jid = jid;

            m_xmppStream = xmppStream;

            m_xmppStream.RegisterSession(m_sessionID, OnIQRequest);

        }



        public void PlaceCall(string destination, SDP sdp)

        {

            m_destination = destination;

            m_sdp = sdp;



            XElement descriptionElement = SDPToJingle.GetDescription(m_sdp);



            m_descriptionID = Crypto.GetRandomString(6);



            XElement callElement = new XElement(JabberClientNS + "iq",

                                    new XAttribute("from", m_jid),

                                    new XAttribute("id", m_descriptionID),

                                    new XAttribute("to", m_destination),

                                    new XAttribute("type", "set"),

                                    new XElement(m_sessionNS + "session",

                                        new XAttribute("type", "initiate"),

                                        new XAttribute("id", m_sessionID),

                                        new XAttribute("initiator", m_jid),

                                        descriptionElement

                                        //new XElement(m_transportNS + "transport")

                                        ));



            logger.Debug("XMPPPhoneSession sending iq with session description.");

            m_xmppStream.WriteElement(callElement, OnIQResponse);

        }



        private void SendCandidates()

        {

            XElement candidatesElement = SDPToJingle.GetCandidates(m_sdp);



            string candidateIqID = Crypto.GetRandomString(6);



            XElement candElement = new XElement(JabberClientNS + "iq",

                                    new XAttribute("from", m_jid),

                                    new XAttribute("id", candidateIqID),

                                    new XAttribute("to", m_destination),

                                    new XAttribute("type", "set"),

                                    new XElement(m_sessionNS + "session",

                                        new XAttribute("type", "candidates"),

                                        new XAttribute("id", m_sessionID),

                                        new XAttribute("initiator", m_jid),

                                        candidatesElement));



            logger.Debug("XMPPPhoneSession sending iq with session candidate.");



            m_xmppStream.WriteElement(candElement, OnIQResponse);

        }



        public void RetargetCallMedia(string ipAddress, int port)

        {

            XElement candidateElement = SDPToJingle.GetCandidate(ipAddress, port);



            string candidateIqID = Crypto.GetRandomString(6);



            XElement candElement = new XElement(JabberClientNS + "iq",

                                    new XAttribute("from", m_jid),

                                    new XAttribute("id", candidateIqID),

                                    new XAttribute("to", m_destination),

                                    new XAttribute("type", "set"),

                                    new XElement(m_sessionNS + "session",

                                        new XAttribute("type", "candidates"),

                                        new XAttribute("id", m_sessionID),

                                        new XAttribute("initiator", m_jid),

                                        candidateElement));



            m_xmppStream.WriteElement(candElement, OnIQResponse);

        }



        public void TerminateCall()

        {

            string iqID = Crypto.GetRandomString(6);



            XElement cancelElement = new XElement(JabberClientNS + "iq",

                                    new XAttribute("from", m_jid),

                                    new XAttribute("id", iqID),

                                    new XAttribute("to", m_destination),

                                    new XAttribute("type", "set"),

                                    new XElement(m_sessionNS + "session",

                                        new XAttribute("type", "terminate"),

                                        new XAttribute("id", m_sessionID),

                                        new XAttribute("initiator", m_jid)));



            logger.Debug("XMPPPhoneSession sending iq to terminate session.");



            m_xmppStream.WriteElement(cancelElement, OnIQResponse);

        }



        /// <summary>

        /// Handler method for receiving responses to iq stanzas initiated by us.

        /// </summary>

        /// <param name="id">The id of the original iq request.</param>

        /// <param name="iq">The iq response stanza.</param>

        public void OnIQResponse(string id, XElement iq)

        {

            //Console.WriteLine("IQ received result for ID " + id + " => " + iq.ToString());

            // Send ok.

            //XAttribute sessionType = iq.Element(m_sessionNS + "session").Attribute("type");

            XAttribute iqType = iq.Attribute("type");



            logger.Debug("XMPPPhoneSession iq response, type=" + iqType.Value + ".");



            if (iqType.Value == "result")

            {

                string iqID = iq.Attribute("id").Value;



                if (iqID == m_descriptionID)

                {

                    SendCandidates();

                }

            }

            else if (iqType.Value == "error")

            {

                int errorCode = 0;

                Int32.TryParse(iq.Element(JabberClientNS + "error").Attribute("code").Value, out errorCode);



                if (errorCode >= 300 && errorCode <= 399)

                {

                    // Redirect.

                    string redirect = iq.Element(JabberClientNS + "error").Element(m_sessionNS + "redirect").Value;

                    m_destination = redirect.Replace("xmpp:", String.Empty);

                    PlaceCall(m_destination, m_sdp);

                }

                else

                {

                    Rejected();

                }

            }

        }



        /// <summary>

        /// Handler method for receiving iq requests from the remote server.

        /// </summary>

        /// <param name="iq">The iq stanza request received.</param>

        public void OnIQRequest(XElement iq)

        {

            logger.Debug("XMPPPhoneSession iq request, type=" + iq.Attribute("type").Value + ".");



            if (iq.Element(m_sessionNS + "session") != null)

            {

                XAttribute sessionType = iq.Element(m_sessionNS + "session").Attribute("type");



                if (sessionType != null)

                {

                    if (sessionType.Value == "candidates")

                    {

                        logger.Debug("XMPPPhoneSession session candidates stanza was received.");



                        XElement candidate = (from cand in iq.Descendants(m_sessionNS + "session").Descendants(m_sessionNS + "candidate")

                                              where cand.Attribute("protocol").Value == "udp"

                                              select cand).First();



                        m_remoteIPAddress = candidate.Attribute("address").Value;

                        Int32.TryParse(candidate.Attribute("port").Value, out m_remotePort);

                        m_remoteUsername = candidate.Attribute("username").Value;

                        m_remotePassword = candidate.Attribute("password").Value;

                    }

                    else if (sessionType.Value == "accept")

                    {

                        logger.Debug("XMPPPhoneSession session accept stanza was received.");



                        m_payloads = (from pl in iq.Descendants(m_sessionNS + "session").Descendants(m_phoneNS + "description")

                                          .Descendants(m_phoneNS + "payload-type")

                                      select pl).ToList();



                        Accepted(SDPToJingle.GetSDP(m_remoteIPAddress, m_remotePort, m_remoteUsername, m_remotePassword, m_payloads));

                    }

                    else if (sessionType.Value == "terminate")

                    {

                        logger.Debug("XMPPPhoneSession session terminate stanza was received.");



                        Hungup();

                    }

                }

                else

                {

                    logger.Warn("XMPPPhoneSession session element was received with a missing type attribute.");

                    logger.Warn(iq.ToString());

                }

            }

            else

            {

                logger.Warn("XMPPPhoneSession an iq element was received with no session element.");

                logger.Warn(iq.ToString());

            }

        }

    }

}