mymessenger.java

* This a simple tool to send/receive UDP packet based on a * free software developed by Neil Deas

/*
 * Copyright (C) 2000  Neil Deason
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, 
 * MA  02111-1307, USA.
 *
 * Author's Address
 *
 * Neil Deason

 * Ubiquity Software Corporation
 * Ubiquity House
 * Langstone Park
 * Newport
 * South Wales
 * NP18 2LH
 */
 
import java.io.*;
import java.net.*;
import java.util.*;

/***************************************************************************************/
/**
 * This interface allows notification of incmong messages to an instance
 * of the Messenger class.
 */
interface MyMessengerObserver
{
	public void notify(DatagramPacket datapacket);
}
/***************************************************************************************/

/***************************************************************************************/
/**
 * A Class that manipulates the MyMsg Object
 * to build the desired SIP Message.
 */
class MyMsgBuilder
{
  private static String VRDNIP="218.19.145.112";
  private static String SIPIP="218.19.145.108";
  
  // Constructor
  MyMsgBuilder()
  {
    printDebug("MyMsgBuilder Initiated");
  }
  
  // Constructor
  MyMsgBuilder(String strVRDN, String strSIP)
  {
    VRDNIP=strVRDN;
    SIPIP=strSIP;
    printDebug("MyMsgBuilder Initiated");
  }

  // Debug Print
  static private void printDebug(String MsgToPrint)
  {
    if(m_Debug)
      System.out.println(MsgToPrint);
  }

  // Debug flags
  static private boolean m_Debug;
  static public void setDebug(boolean flag)
  {
    m_Debug=flag;
  }
  static public boolean getDebug()
  {
    return m_Debug;
  }

 
  // To be verified....
  public static void addSDP(MyMsg IncMsg, MyMsg OutMsg)
  {
    byte[] LF=new byte[2];
    LF[0]=0x0D;
    LF[1]=0x0A;
    String LineF=new String(LF);

    String oBody = OutMsg.toString();
    
    // To trim the pending LF.
    // But presently, this while loop does not seem to work.
    while(oBody.endsWith(LineF))
    {
      printDebug("Code Trim Space Executed");
      oBody=oBody.substring(0,oBody.length()-2);
    }
    
    String LineSDP=IncMsg.getSDP();
    Integer tmp=new Integer(LineSDP.length());
    String LineCon="Content-Type:application/sdp; charset=ISO10646";
    String LineLen="Content-Length:"+tmp.toString();
    oBody=oBody+LineF+LineCon+LineF+LineLen+LineF+LineF+IncMsg.getSDP()+LineF+LineF;
    // A blank line to separate the Header(Various headers) from BODY(SDP).
    
    OutMsg.setBody(oBody);
  } 
   
  // To be verified....
  public static void addCallID(String CallID, MyMsg OutMsg)
  {
    byte[] LF=new byte[2];
    LF[0]=0x0D;
    LF[1]=0x0A;
    String LineF=new String(LF);

    String oBody = OutMsg.toString();

    // To trim the pending LF.
    while(oBody.endsWith(LineF))
    {
      oBody=oBody.substring(0,oBody.length()-2);
    }
    
    oBody=oBody+CallID+LineF+LineF;
    
    OutMsg.setBody(oBody);
  }

   
  /** this is merely a test method to figure out what response is expected by GWC
   *  And should not be regarded as a method to use when doing SIP verification.
   *
   *  :p IT WORKS!!
   *  If a message follows the following format, it will be recognized by CS2Kc.
   *  LineFeed to terminate a Header
   *  Double LineFeed to terminate a Message.
   *  A Blank line to seperate the Message Header and the Msg Body.
   *
   */
  public static MyMsg build100(MyMsg InvMsg)
  {
    byte[] LF=new byte[2];
    LF[0]=0x0D;
    LF[1]=0x0A;
    String LineF=new String(LF);
    
    if(InvMsg == null)
      return null;
      
    printDebug("Start Building 100 Msg");
    
    String Line100="SIP/2.0 100 Trying";
    String LineVia=InvMsg.getVia();
    String LineTo=InvMsg.getTo();
    String LineFrom=InvMsg.getFrom();
    String LineCallID=InvMsg.getCallID();
    String LineCSeq=InvMsg.getCseq();
    String LineLen="Content-Length:0";
    
    //Start to build response.
    String strBody=Line100+LineF+LineVia+LineF+LineTo+LineF+LineFrom+LineF+LineCallID+LineF+LineCSeq+LineF+LineLen+LineF+LineF;
    MyMsg OutMsg=new MyMsg(strBody);

    printDebug("100 Msg Built");
    return OutMsg;
  }

/*
  public static MyMsg buildPRACK(MyMsg InvMsg, MyMsg In18xMsg)
  {
    byte[] LF=new byte[2];
    LF[0]=0x0D;
    LF[1]=0x0A;
    String LineF=new String(LF);
    
    if(InMsg == null)
      return null;
      
    printDebug("Start Building PRACK Msg");
    
    String Line100="PRACK "+InvMsg.getURI();
    String LineVia=In18xMsg.getVia();
    String LineTo=In18xMsg.getTo();
    String LineFrom=In18xMsg.getFrom();
    String LineCallID=In18xMsg.getCallID();
    String LineCSeq=In18xMsg.getCseq();
    String LineRAckTmp=In18xMsg().getRseq();
    StringTokenizer st_Rack=new StringTokenizer(LineRAckTmp);
    
    
    String LineLen="Content-Length:0";
    
    //Start to build response.
    String strBody=Line100+LineF+LineVia+LineF+LineTo+LineF+LineFrom+LineF+LineCallID+LineF+LineCSeq+LineF+LineLen+LineF+LineF;
    MyMsg OutMsg=new MyMsg(strBody);

    printDebug("100 Msg Built");
    return OutMsg;
  }
*/
  
  /** this is merely a test method to figure out whether my understanding of the S
   *  SIP protocol is corrrect. In no case should this method be called during a
   *  SIP protocol verification. 
   */
  public static MyMsg buildInv()
  {
    byte[] LF=new byte[2];
    LF[0]=0x0A;
    LF[1]=0x0D;
    String LineF=new String(LF);
    
    printDebug("Start Building Inv Msg");
    
    String LineMethod="INVITE sip:8302118@"+SIPIP+" SIP/2.0";
    String LineVia="Via:SIP/2.0/UDP SIPTESTER";
    String LineCallID="Call-ID:2002-08-07-1745@SIPTESTER";
    String LineTo="To:<sip:8302118@MGCA;user=phone>";
    String LineFrom="From:<sip:08806@SIPTESTER;user=phone>";
    String LineContact="Contact:<sip:08806@SIPTESTER;user=phone>";
    String LineRemote="Remote-Party-ID:<sip:8806@SIPTESTER;user=phone>;party=calling;id-type=subscriber";
    String LineProf="X-Nortel-Profile:SIPTESTPROF";
    String LineCSeq="CSeq:1 INVITE";
    String LineSupport="Supported:100rel";
    String LinePayload="Content-Type:application/sdp; charset=ISO10646";
    String SDP1="v=0";
    String SDP2="c=IN IP4 202.38.32.112";
    String SDP3="m=audio 10000 RTP/AVP 8";
    String SDP4="a=ptime:20";
    Integer tmp=new Integer(SDP1.length()+2+SDP2.length()+2+SDP3.length()+2+SDP4.length());
    // 2 for CRLF
    String LineLen="Content-Length:"+tmp.toString();
    
    String Msg=LineMethod+LineF+LineCallID+LineF+LineVia+LineF+LineTo+LineF+LineFrom+LineF+LineContact+LineF+LineProf+LineF+LineCSeq+LineF+LineSupport+LineF+LinePayload+LineF+LineLen+LineF+LineF+SDP1+LineF+SDP2+LineF+SDP3+LineF+SDP4+LineF+LineF+LineF;
    
    printDebug("INVITE Built");
    MyMsg mymsg = new MyMsg(Msg);
    return mymsg;
  }

  public static MyMsg build200Bye(MyMsg IncMsg)
  {
    byte[] LF=new byte[2];
    LF[0]=0x0D;
    LF[1]=0x0A;
    String LineF=new String(LF);
    
    if(IncMsg == null)
      return null;
      
    printDebug("Start Building 200 Msg");
    
    String Line200="SIP/2.0 200 OK";
    String LineVia=IncMsg.getVia();
    String LineTo=IncMsg.getTo();
    String LineFrom=IncMsg.getFrom();
    String LineCallID=IncMsg.getCallID();
    String LineCSeq=IncMsg.getCseq();
    String LineLen="Content-Length:0";
    
    //Start to build response.
    String strBody=Line200+LineF+LineVia+LineF+LineTo+LineF+LineFrom+LineF+LineCallID+LineF+LineCSeq+LineF+LineLen+LineF+LineF;
    MyMsg OutMsg=new MyMsg(strBody);

    printDebug("200 Msg Built");
    return OutMsg;
  }

	public static MyMsg buildOptionsResp100(MyMsg msg)
	{
		byte[] Delimer = new byte[2];
		Delimer[0]=0x0D;
		Delimer[1]=0x0A;
		
		String LineFeed=new String(Delimer);
		
		boolean MsgComplete=false;
		String LineFrom=msg.getFrom();
		String LineTo=msg.getTo();
		String CallID=msg.getCallID();
  	String LineSupport="Supported:com.nortelnetworks.firewall,100rel";
    String LineVia=msg.getVia()+";received="+VRDNIP;
    String LineCseq=msg.getCseq();
		String ContentLength="Content-Length:0";
		String Server="Server:IMS1.0";
		String My100Msg="SIP/2.0 100 Trying";
		String strMyMsg=null;

		if((LineFrom != null) && (LineTo != null) && (CallID != null))
		{
      //Build 100
      strMyMsg=My100Msg+LineFeed+LineVia+LineFeed+LineTo+LineFeed+LineFrom+LineFeed+CallID+LineFeed+LineCseq+LineFeed+LineSupport+LineFeed+ContentLength+LineFeed+Server+LineFeed+LineFeed;
		}
		MyMsg outMsg=new MyMsg(strMyMsg);
		return outMsg;
	}

	public static MyMsg buildOptionsResp200(MyMsg msg)
	{
		byte[] Delimer = new byte[2];
		Delimer[0]=0x0D;
		Delimer[1]=0x0A;
		
		String LineFeed=new String(Delimer);
		
		boolean MsgComplete=false;
		String LineFrom=msg.getFrom();
		String LineTo=msg.getTo();
		String CallID=msg.getCallID();
  	String LineSupport="Supported:com.nortelnetworks.firewall,100rel";
    String LineVia=msg.getVia()+";received="+VRDNIP;
    String LineCseq=msg.getCseq();
		String ContentLength="Content-Length:0";
		String Server="Server:IMS1.0";
		String My200Msg="SIP/2.0 200 OK";
		String strMyMsg=null;

		if((LineFrom != null) && (LineTo != null) && (CallID != null))
		{
      //Build 200
	    Calendar Cc=Calendar.getInstance();
		  long MyTimeStamp=(Cc.get(Calendar.MONTH)+1)*60*60*24*30+Cc.get(Calendar.DAY_OF_MONTH)*60*60*24+Cc.get(Calendar.HOUR_OF_DAY)*60*60+Cc.get(Calendar.MINUTE)*60+Cc.get(Calendar.SECOND);
			LineTo=msg.getTo()+";tag:"+MyTimeStamp;

			strMyMsg=My200Msg+LineFeed+LineVia+LineFeed+LineTo+LineFeed+LineFrom+LineFeed+CallID+LineFeed+LineCseq+LineFeed+LineSupport+LineFeed+ContentLength+LineFeed+Server+LineFeed+LineFeed;
		}
    
    MyMsg outMsg = new MyMsg(strMyMsg);
    return outMsg;		
	}
	
  /**
   * Due to the limited timeframe, It is not possible for me to put the code to handle 
   * the registration/deregistration request in this release.
   * However, the underlying protocol details are known now. 
   * Register:
   *    Client send "REGISTER" request with the EXPIRES header, in which contains the 
   *    time it requested for this session.(in seconds.)(e.g. expires:3600)
   *    Server respond with a 100 trying to stop the retransmission of the REGISTER request
   *    then respond with a 200 OK msg in which the CONTACT header in the request are modified
   *    ANd "q=0.0" and "expires=3600"(extracted from the expires header) are pended.
   *    And the registration is finished.
   *
   * Deregister:
   *    Client send a "REGISTER" with EXPIRES header set to 0.(session will be expire in 0 seconds.)
   *    The server respond with "100 Trying" then "200 OK"(Without Contact Header!)
   */

	public static MyMsg buildRegisterResp200(MyMsg msg)
	{
		byte[] Delimer = new byte[2];
		Delimer[0]=0x0D;
		Delimer[1]=0x0A;
		String LineFeed=new String(Delimer);

	  String Line200="SIP/2.0 200 Registration Successful";
	  String LineVia = msg.getVia();
	  String LineTo = msg.getTo();
	  String LineFrom = msg.getFrom();
	  String LineCallID = msg.getCallID();
	  String LineCseq = msg.getCseq();
	  String LineSupported = "Supported:com.nortelnetworks.firewall, 100rel";
	  String LineConLen = "Content-Length:0";
	  String LineServer="Server:IMS 1.0";
	  // To simplify the implementation, the following lines are hard-coded.....
	  // Anyway, we just want to have the SIP CLIENT register, right..:)
	  String LineContact="Contact:<sip:[e-mail];transport=udp;nt_disposition=firewall_client>;q=0.0;expires=3600";
	  String LineMaxFwd="Max-Forwards: 20";
	  
	  String strBody=Line200+LineFeed+LineVia+LineFeed+LineTo+LineFeed+LineFrom+LineFeed+LineCallID+LineFeed+LineCseq+LineFeed+LineSupported+LineFeed+LineConLen+LineFeed+LineServer+LineFeed+LineContact+LineFeed+LineMaxFwd+LineFeed+LineFeed;
	  
	  MyMsg oMsg = new MyMsg(strBody);
	  return oMsg;
	  
  }

	public static MyMsg buildRegisterResp100(MyMsg msg)
	{
		byte[] Delimer = new byte[2];
		Delimer[0]=0x0D;
		Delimer[1]=0x0A;
		String LineFeed=new String(Delimer);

	  String Line100="SIP/2.0 100 Trying";
	  String LineVia = msg.getVia();
	  String LineTo = msg.getTo();
	  String LineFrom = msg.getFrom();
	  String LineCallID = msg.getCallID();
	  String LineCseq = msg.getCseq();
	  String LineSupported = "Supported:com.nortelnetworks.firewall, 100rel";
	  String LineConLen = "Content-Length:0";
	  String LineServer="Server:IMS 1.0";

	  String strBody=Line100+LineFeed+LineVia+LineFeed+LineTo+LineFeed+LineFrom+LineFeed+LineCallID+LineFeed+LineCseq+LineFeed+LineSupported+LineFeed+LineConLen+LineFeed+LineServer+LineFeed+LineFeed;
	  
	  MyMsg oMsg = new MyMsg(strBody);
	  return oMsg;
	  
  }

 }
/***************************************************************************************/



/***************************************************************************************/
/**
 * SIP Message Object
 * Following Rules are to be followed if a message be recognized by CS2Kc.
 *   =============================================================
 *   LineFeed to terminate a Header
 *   Double LineFeed to terminate a Message.
 *   A Blank line to seperate the Message Header and the Msg Body.
 *   =============================================================
 */
class MyMsg
{
  // The Body field of the MyMsg Class contains the full message.
  private String Body;

  // The following fields will be filled automatically using myMsgParser method
  private String MySDP;
	private String MyMethod;
  private String MyCallID;
	private String MyCseq; 	
	private String MyFrom;
	private String MyTo;
	private String MyVia;
	private String MyBoundary;
	private String MyURI;