/*    This file is part of Peers.    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 3 of the License, or    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, see <http://www.gnu.org/licenses/>.        Copyright 2007, 2008 Yohann Martineau */package net.sourceforge.peers.sip;import static net.sourceforge.peers.sip.RFC3261.HDR_VIA;import java.net.InetAddress;import java.net.NetworkInterface;import java.net.SocketException;import java.net.UnknownHostException;import java.util.Enumeration;import net.sourceforge.peers.sip.core.Config;import net.sourceforge.peers.sip.core.useragent.UserAgent;import net.sourceforge.peers.sip.syntaxencoding.SipHeaderFieldMultiValue;import net.sourceforge.peers.sip.syntaxencoding.SipHeaderFieldName;import net.sourceforge.peers.sip.syntaxencoding.SipHeaderFieldValue;import net.sourceforge.peers.sip.syntaxencoding.SipHeaders;import net.sourceforge.peers.sip.transaction.Transaction;import net.sourceforge.peers.sip.transaction.TransactionManager;import net.sourceforge.peers.sip.transport.SipMessage;import net.sourceforge.peers.sip.transport.SipRequest;import net.sourceforge.peers.sip.transport.SipResponse;import org.dom4j.Node;public class Utils {    private static Utils INSTANCE;        public static Utils getInstance() {        if (INSTANCE == null) {            INSTANCE = new Utils();        }        return INSTANCE;    }        private InetAddress myAddress;    private int sipPort;    private int rtpPort;    private int cseqCounter;    private Utils() {        super();                Config config = UserAgent.getInstance().getConfig();        Node node = config.selectSingleNode("//peers:address");        if (node == null) {          try {                boolean found = false;                Enumeration<NetworkInterface> e = NetworkInterface                        .getNetworkInterfaces();                while (e.hasMoreElements() && !found) {                    NetworkInterface networkInterface = e.nextElement();//                    Logger.getInstance().debug(networkInterface.getDisplayName());                    Enumeration<InetAddress> f = networkInterface                            .getInetAddresses();                    while (f.hasMoreElements() && !found) {                        InetAddress inetAddress = f.nextElement();                        if (inetAddress.isSiteLocalAddress()) {                            this.myAddress = inetAddress;                            found = true;                        }                    }                }            } catch (SocketException e) {                e.printStackTrace();            }        } else {            try {                myAddress = InetAddress.getByName(node.getText());            } catch (UnknownHostException e) {                e.printStackTrace();            }        }        node = config.selectSingleNode("//peers:sip/peers:profile/peers:port");        if (node == null) {            sipPort = RFC3261.TRANSPORT_DEFAULT_PORT;        } else {            sipPort = Integer.parseInt(node.getText());        }                node = config.selectSingleNode("//peers:rtp/peers:port");        rtpPort = Integer.parseInt(node.getText());        cseqCounter = 0;    }    public InetAddress getMyAddress() {        return myAddress;    }        public int getSipPort() {        return sipPort;    }    public int getRtpPort() {        return rtpPort;    }    public SipHeaderFieldValue getTopVia(SipMessage sipMessage) {        SipHeaders sipHeaders = sipMessage.getSipHeaders();        SipHeaderFieldName viaName = new SipHeaderFieldName(HDR_VIA);        SipHeaderFieldValue via = sipHeaders.get(viaName);        if (via instanceof SipHeaderFieldMultiValue) {            via = ((SipHeaderFieldMultiValue)via).getValues().get(0);        }        return via;    }        public String generateTag() {        return randomString(8);    }        public String generateCallID() {        //TODO make a hash using current time millis, public ip @, private @, and a random string        StringBuffer buf = new StringBuffer();        buf.append(randomString(8));        buf.append('-');        buf.append(String.valueOf(System.currentTimeMillis()));        buf.append('@');        buf.append(myAddress.getHostName());        return buf.toString();    }        public String generateCSeq(String method) {        StringBuffer buf = new StringBuffer();        buf.append(cseqCounter++);        buf.append(' ');        buf.append(method);        return buf.toString();    }        public String generateBranchId() {        StringBuffer buf = new StringBuffer();        buf.append(RFC3261.BRANCHID_MAGIC_COOKIE);        //TODO must be unique across space and time...        buf.append(randomString(9));        return buf.toString();    }        public String getMessageCallId(SipMessage sipMessage) {        SipHeaderFieldValue callId = sipMessage.getSipHeaders().get(                new SipHeaderFieldName(RFC3261.HDR_CALLID));        return callId.getValue();    }        public String randomString(int length) {        String chars = "abcdefghijklmnopqrstuvwxyz" +                       "ABCDEFGHIFKLMNOPRSTUVWXYZ" +                       "0123456789";        StringBuffer buf = new StringBuffer(length);        for (int i = 0; i < length; ++i) {            int pos = (int)Math.round(Math.random() * (chars.length() - 1));            buf.append(chars.charAt(pos));        }        return buf.toString();    }        public void copyHeader(SipMessage src, SipMessage dst, String name) {        SipHeaderFieldName sipHeaderFieldName = new SipHeaderFieldName(name);        SipHeaderFieldValue sipHeaderFieldValue = src.getSipHeaders().get(sipHeaderFieldName);        if (sipHeaderFieldValue != null) {            dst.getSipHeaders().add(sipHeaderFieldName, sipHeaderFieldValue);        }    }        /**     * adds Max-Forwards Supported and Require headers     * @param headers     */    public void addCommonHeaders(SipHeaders headers) {        //Max-Forwards                headers.add(new SipHeaderFieldName(RFC3261.HDR_MAXFORWARDS),                new SipHeaderFieldValue(                        String.valueOf(RFC3261.DEFAULT_MAXFORWARDS)));                //TODO Supported and Require    }            public String getUserPart(String sipUri) {        int start = sipUri.indexOf(RFC3261.SCHEME_SEPARATOR);        int end = sipUri.indexOf(RFC3261.AT);        return sipUri.substring(start + 1, end);    }    /**     * Gives the sipMessage if sipMessage is a SipRequest or      * the SipRequest corresponding to the SipResponse     * if sipMessage is a SipResponse     * @param sipMessage     * @return null if sipMessage is neither a SipRequest neither a SipResponse     */    public SipRequest getSipRequest(SipMessage sipMessage) {        if (sipMessage instanceof SipRequest) {            return (SipRequest) sipMessage;        } else if (sipMessage instanceof SipResponse) {            SipResponse sipResponse = (SipResponse) sipMessage;            Transaction transaction = (Transaction)TransactionManager                .getInstance().getClientTransaction(sipResponse);            if (transaction == null) {                transaction = (Transaction)TransactionManager                    .getInstance().getServerTransaction(sipResponse);            }            if (transaction == null) {                return null;            }            return transaction.getRequest();        } else {            return null;        }    }}