/dumbhippo/trunk/openfire/src/java/org/jivesoftware/openfire/http/HttpBindServlet.java

/**

 * $Revision: $

 * $Date: $

 *

 * Copyright (C) 2007 Jive Software. All rights reserved.

 *

 * This software is published under the terms of the GNU Public License (GPL),

 * a copy of which is included in this distribution.

 */



package org.jivesoftware.openfire.http;



import org.xmlpull.v1.XmlPullParserFactory;

import org.xmlpull.v1.XmlPullParserException;

import org.jivesoftware.util.Log;

import org.jivesoftware.util.JiveGlobals;

import org.jivesoftware.openfire.net.MXParser;

import org.jivesoftware.openfire.auth.UnauthorizedException;

import org.dom4j.io.XMPPPacketReader;

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.Element;

import org.dom4j.DocumentHelper;

import org.mortbay.util.ajax.ContinuationSupport;

import org.apache.commons.lang.StringEscapeUtils;



import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.ServletException;

import javax.servlet.ServletConfig;

import java.io.IOException;

import java.io.InputStream;

import java.io.ByteArrayInputStream;

import java.net.InetAddress;

import java.net.URLDecoder;



/**

 * Servlet which handles requests to the HTTP binding service. It determines if there is currently

 * an {@link HttpSession} related to the connection or if one needs to be created and then passes it

 * off to the {@link HttpBindManager} for processing of the client request and formulating of the

 * response.

 *

 * @author Alexander Wenckus

 */

public class HttpBindServlet extends HttpServlet {

    private HttpSessionManager sessionManager;



    private static XmlPullParserFactory factory;



    static {

        try {

            factory = XmlPullParserFactory.newInstance(MXParser.class.getName(), null);

        }

        catch (XmlPullParserException e) {

            Log.error("Error creating a parser factory", e);

        }

    }



    private ThreadLocal<XMPPPacketReader> localReader = new ThreadLocal<XMPPPacketReader>();



    public HttpBindServlet() {

    }





    @Override

    public void init(ServletConfig servletConfig) throws ServletException {

        super.init(servletConfig);

        sessionManager = HttpBindManager.getInstance().getSessionManager();

        sessionManager.start();

    }





    @Override

    public void destroy() {

        super.destroy();

        sessionManager.stop();

    }



    @Override

    protected void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException

    {

        boolean isScriptSyntaxEnabled =

                JiveGlobals.getBooleanProperty("xmpp.httpbind.scriptSyntax.enabled", false);

        if(!isScriptSyntaxEnabled) {

            sendLegacyError(response, BoshBindingError.itemNotFound);

            return;

        }



        if (isContinuation(request, response)) {

            return;

        }

        String queryString = request.getQueryString();

        if (queryString == null || "".equals(queryString)) {

            sendLegacyError(response, BoshBindingError.badRequest);

            return;

        }

        queryString = URLDecoder.decode(queryString, "utf-8");



        parseDocument(request, response, new ByteArrayInputStream(queryString.getBytes()));

    }



    private void sendLegacyError(HttpServletResponse response, BoshBindingError error)

            throws IOException

    {

        response.sendError(error.getLegacyErrorCode());

    }





    @Override

    protected void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        if (isContinuation(request, response)) {

            return;

        }



        parseDocument(request, response, request.getInputStream());

    }



    private void parseDocument(HttpServletRequest request, HttpServletResponse response,

                               InputStream documentContent)

            throws IOException {



        Document document;

        try {

            document = createDocument(documentContent);

        }

        catch (Exception e) {

            Log.warn("Error parsing user request. [" + request.getRemoteAddr() + "]");

            sendLegacyError(response, BoshBindingError.badRequest);

            return;

        }



        Element node = document.getRootElement();

        if (node == null || !"body".equals(node.getName())) {

            Log.warn("Body missing from request content. [" + request.getRemoteAddr() + "]");

            sendLegacyError(response, BoshBindingError.badRequest);

            return;

        }



        String sid = node.attributeValue("sid");

        // We have a new session

        if (sid == null) {

            createNewSession(request, response, node);

        }

        else {

            handleSessionRequest(sid, request, response, node);

        }

    }



    private boolean isContinuation(HttpServletRequest request, HttpServletResponse response)

            throws IOException

    {

        HttpSession session = (HttpSession) request.getAttribute("request-session");

        if (session == null) {

            return false;

        }

        synchronized (session) {

            try {

                respond(response, session.getResponse((Long) request.getAttribute("request")),

                        request.getMethod());

            }

            catch (HttpBindException e) {

                sendError(request, response, e.getBindingError(), session);

            }

        }

        return true;

    }



    private void sendError(HttpServletRequest request, HttpServletResponse response,

                           BoshBindingError bindingError, HttpSession session)

            throws IOException

    {

        try {

            if (session.getVersion() >= 1.6) {

                respond(response, createErrorBody(bindingError.getErrorType().getType(),

                        bindingError.getCondition()), request.getMethod());

            }

            else {

                sendLegacyError(response, bindingError);

            }

        }

        finally {

            if (bindingError.getErrorType() == BoshBindingError.Type.terminal) {

                session.close();

            }

        }

    }



    private String createErrorBody(String type, String condition) {

        Element body = DocumentHelper.createElement("body");

        body.addNamespace("", "http://jabber.org/protocol/httpbind");

        body.addAttribute("type", type);

        body.addAttribute("condition", condition);

        return body.asXML();

    }



    private void handleSessionRequest(String sid, HttpServletRequest request,

                                      HttpServletResponse response, Element rootNode)

            throws IOException

    {

        long rid = getLongAttribue(rootNode.attributeValue("rid"), -1);

        if (rid <= 0) {

            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Body missing RID (Request ID)");

            return;

        }



        HttpSession session = sessionManager.getSession(sid);

        if (session == null) {

            Log.warn("Client provided invalid session: " + sid + ". [" +

                    request.getRemoteAddr() + "]");

            response.sendError(HttpServletResponse.SC_NOT_FOUND, "Invalid SID.");

            return;

        }

        synchronized (session) {

            HttpConnection connection;

            try {

                connection = sessionManager.forwardRequest(rid, session,

                        request.isSecure(), rootNode);

            }

            catch (HttpBindException e) {

                sendError(request, response, e.getBindingError(), session);

                return;

            }

            catch (HttpConnectionClosedException nc) {

                Log.error("Error sending packet to client.", nc);

                return;

            }



            String type = rootNode.attributeValue("type");

            if ("terminate".equals(type)) {

                session.close();

                respond(response, createEmptyBody(), request.getMethod());

            }

            else {

                connection

                        .setContinuation(ContinuationSupport.getContinuation(request, connection));

                request.setAttribute("request-session", connection.getSession());

                request.setAttribute("request", connection.getRequestId());

                try {

                    respond(response, session.getResponse(connection.getRequestId()),

                            request.getMethod());

                }

                catch (HttpBindException e) {

                    sendError(request, response, e.getBindingError(), session);

                }

            }

        }

    }



    private void createNewSession(HttpServletRequest request, HttpServletResponse response,

                                  Element rootNode)

            throws IOException

    {

        long rid = getLongAttribue(rootNode.attributeValue("rid"), -1);

        if (rid <= 0) {

            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Body missing RID (Request ID)");

            return;

        }



        try {

            HttpConnection connection = new HttpConnection(rid, request.isSecure());

            InetAddress address = InetAddress.getByName(request.getRemoteAddr());

            connection.setSession(sessionManager.createSession(address, rootNode, connection));

            respond(response, connection, request.getMethod());

        }

        catch (UnauthorizedException e) {

            // Server wasn't initialized yet.

            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,

                    "Server Not initialized");

        }

        catch (HttpBindException e) {

            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);

        }



    }



    private void respond(HttpServletResponse response, HttpConnection connection, String method)

            throws IOException

    {

        String content;

        try {

            content = connection.getResponse();

        }

        catch (HttpBindTimeoutException e) {

            content = createEmptyBody();

        }



        respond(response, content, method);

    }



    private void respond(HttpServletResponse response, String content, String method)

            throws IOException {

        response.setStatus(HttpServletResponse.SC_OK);

        response.setContentType("GET".equals(method) ? "text/javascript" : "text/xml");

        response.setCharacterEncoding("utf-8");



        if ("GET".equals(method)) {

            content = "_BOSH_(\"" + StringEscapeUtils.escapeJavaScript(content) + "\")";

        }



        byte[] byteContent = content.getBytes("utf-8");

        response.setContentLength(byteContent.length);

        response.getOutputStream().write(byteContent);

    }



    private static String createEmptyBody() {

        Element body = DocumentHelper.createElement("body");

        body.addNamespace("", "http://jabber.org/protocol/httpbind");

        return body.asXML();

    }



    private long getLongAttribue(String value, long defaultValue) {

        if (value == null || "".equals(value)) {

            return defaultValue;

        }

        try {

            return Long.valueOf(value);

        }

        catch (Exception ex) {

            return defaultValue;

        }

    }



    private XMPPPacketReader getPacketReader() {

        // Reader is associated with a new XMPPPacketReader

        XMPPPacketReader reader = localReader.get();

        if (reader == null) {

            reader = new XMPPPacketReader();

            reader.setXPPFactory(factory);

            localReader.set(reader);

        }

        return reader;

    }



    private Document createDocument(InputStream request) throws

            DocumentException, IOException, XmlPullParserException

    {

        return getPacketReader().read("utf-8", request);

    }

}