/*
* Copyright (c) 2008-2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.cometd.server.transport;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.security.Principal;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;
import javax.servlet.AsyncContext;
import javax.servlet.AsyncEvent;
import javax.servlet.AsyncListener;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.cometd.bayeux.Channel;
import org.cometd.bayeux.Message;
import org.cometd.bayeux.server.BayeuxContext;
import org.cometd.bayeux.server.ServerMessage;
import org.cometd.bayeux.server.ServerSession;
import org.cometd.server.AbstractServerTransport;
import org.cometd.server.BayeuxServerImpl;
import org.cometd.server.ServerSessionImpl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <p>HTTP ServerTransport base class, used by ServerTransports that use
* HTTP as transport or to initiate a transport connection.</p>
*/
public abstract class AbstractHttpTransport extends AbstractServerTransport
{
public final static String PREFIX = "long-polling";
public static final String JSON_DEBUG_OPTION = "jsonDebug";
public static final String MESSAGE_PARAM = "message";
public final static String BROWSER_COOKIE_NAME_OPTION = "browserCookieName";
public final static String BROWSER_COOKIE_DOMAIN_OPTION = "browserCookieDomain";
public final static String BROWSER_COOKIE_PATH_OPTION = "browserCookiePath";
public final static String MAX_SESSIONS_PER_BROWSER_OPTION = "maxSessionsPerBrowser";
public final static String MULTI_SESSION_INTERVAL_OPTION = "multiSessionInterval";
public final static String AUTOBATCH_OPTION = "autoBatch";
public final static String ALLOW_MULTI_SESSIONS_NO_BROWSER_OPTION = "allowMultiSessionsNoBrowser";
protected final Logger _logger = LoggerFactory.getLogger(getClass());
private final ThreadLocal<HttpServletRequest> _currentRequest = new ThreadLocal<>();
private final ConcurrentHashMap<String, AtomicInteger> _browserMap = new ConcurrentHashMap<>();
private final Map<String, AtomicInteger> _browserSweep = new ConcurrentHashMap<>();
private String _browserCookieName;
private String _browserCookieDomain;
private String _browserCookiePath;
private int _maxSessionsPerBrowser;
private long _multiSessionInterval;
private boolean _autoBatch;
private boolean _allowMultiSessionsNoBrowser;
private long _lastSweep;
protected AbstractHttpTransport(BayeuxServerImpl bayeux, String name)
{
super(bayeux, name);
setOptionPrefix(PREFIX);
}
@Override
public void init()
{
super.init();
_browserCookieName = getOption(BROWSER_COOKIE_NAME_OPTION, "BAYEUX_BROWSER");
_browserCookieDomain = getOption(BROWSER_COOKIE_DOMAIN_OPTION, null);
_browserCookiePath = getOption(BROWSER_COOKIE_PATH_OPTION, "/");
_maxSessionsPerBrowser = getOption(MAX_SESSIONS_PER_BROWSER_OPTION, 1);
_multiSessionInterval = getOption(MULTI_SESSION_INTERVAL_OPTION, 2000);
_autoBatch = getOption(AUTOBATCH_OPTION, true);
_allowMultiSessionsNoBrowser = getOption(ALLOW_MULTI_SESSIONS_NO_BROWSER_OPTION, false);
}
protected long getMultiSessionInterval()
{
return _multiSessionInterval;
}
protected boolean isAutoBatch()
{
return _autoBatch;
}
protected boolean isAllowMultiSessionsNoBrowser()
{
return _allowMultiSessionsNoBrowser;
}
public void setCurrentRequest(HttpServletRequest request)
{
_currentRequest.set(request);
}
public HttpServletRequest getCurrentRequest()
{
return _currentRequest.get();
}
public abstract boolean accept(HttpServletRequest request);
public abstract void handle(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException;
protected abstract HttpScheduler suspend(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, ServerMessage.Mutable reply, String browserId, long timeout);
protected abstract void write(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, boolean startInterval, List<ServerMessage> messages, ServerMessage.Mutable[] replies);
protected void processMessages(HttpServletRequest request, HttpServletResponse response, ServerMessage.Mutable[] messages) throws IOException
{
boolean autoBatch = isAutoBatch();
ServerSessionImpl session = null;
boolean batch = false;
boolean sendQueue = true;
boolean sendReplies = true;
boolean startInterval = false;
boolean disconnected = false;
try
{
for (int i = 0; i < messages.length; ++i)
{
ServerMessage.Mutable message = messages[i];
if (_logger.isDebugEnabled())
_logger.debug("Processing {}", message);
if (session == null && !disconnected)
session = (ServerSessionImpl)getBayeux().getSession(message.getClientId());
if (session != null)
{
disconnected = !session.isHandshook();
if (disconnected)
{
if (batch)
{
batch = false;
session.endBatch();
}
session = null;
}
else
{
if (autoBatch && !batch)
{
batch = true;
session.startBatch();
}
}
}
switch (message.getChannel())
{
case Channel.META_HANDSHAKE:
{
if (messages.length > 1)
throw new IOException();
ServerMessage.Mutable reply = processMetaHandshake(request, response, session, message);
if (reply != null)
session = (ServerSessionImpl)getBayeux().getSession(reply.getClientId());
messages[i] = processReply(session, reply);
sendQueue = false;
break;
}
case Channel.META_CONNECT:
{
ServerMessage.Mutable reply = processMetaConnect(request, response, session, message);
messages[i] = processReply(session, reply);
startInterval = sendQueue = sendReplies = reply != null;
break;
}
default:
{
ServerMessage.Mutable reply = bayeuxServerHandle(session, message);
messages[i] = processReply(session, reply);
break;
}
}
}
if (sendReplies || sendQueue)
flush(request, response, session, sendQueue, startInterval, messages);
}
finally
{
if (batch)
session.endBatch();
}
}
protected ServerMessage.Mutable processMetaHandshake(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, ServerMessage.Mutable message)
{
ServerMessage.Mutable reply = bayeuxServerHandle(session, message);
if (reply != null)
{
session = (ServerSessionImpl)getBayeux().getSession(reply.getClientId());
if (session != null)
{
String browserId = findBrowserId(request);
if (browserId == null)
setBrowserId(request, response);
}
}
return reply;
}
protected ServerMessage.Mutable processMetaConnect(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, ServerMessage.Mutable message)
{
if (session != null)
{
// Cancel the previous scheduler to cancel any prior waiting long poll.
// This should also decrement the browser ID.
session.setScheduler(null);
}
boolean wasConnected = session != null && session.isConnected();
ServerMessage.Mutable reply = bayeuxServerHandle(session, message);
if (reply != null && session != null)
{
if (!session.hasNonLazyMessages() && reply.isSuccessful())
{
// Detect if we have multiple sessions from the same browser
// Note that CORS requests do not send cookies, so we need to handle them specially
// CORS requests always have the Origin header
String browserId = findBrowserId(request);
boolean allowSuspendConnect;
if (browserId != null)
allowSuspendConnect = incBrowserId(browserId, session);
else
allowSuspendConnect = isAllowMultiSessionsNoBrowser() || request.getHeader("Origin") != null;
if (allowSuspendConnect)
{
long timeout = session.calculateTimeout(getTimeout());
// Support old clients that do not send advice:{timeout:0} on the first connect
if (timeout > 0 && wasConnected && session.isConnected())
{
// Between the last time we checked for messages in the queue
// (which was false, otherwise we would not be in this branch)
// and now, messages may have been added to the queue.
// We will suspend anyway, but setting the scheduler on the
// session will decide atomically if we need to resume or not.
HttpScheduler scheduler = suspend(request, response, session, reply, browserId, timeout);
metaConnectSuspended(request, response, scheduler.getAsyncContext(), session);
// Setting the scheduler may resume the /meta/connect
session.setScheduler(scheduler);
reply = null;
}
else
{
decBrowserId(browserId, session);
}
}
else
{
// There are multiple sessions from the same browser
Map<String, Object> advice = reply.getAdvice(true);
if (browserId != null)
advice.put("multiple-clients", true);
long multiSessionInterval = getMultiSessionInterval();
if (multiSessionInterval > 0)
{
advice.put(Message.RECONNECT_FIELD, Message.RECONNECT_RETRY_VALUE);
advice.put(Message.INTERVAL_FIELD, multiSessionInterval);
}
else
{
advice.put(Message.RECONNECT_FIELD, Message.RECONNECT_NONE_VALUE);
reply.setSuccessful(false);
}
session.reAdvise();
}
}
if (reply != null && session.isDisconnected())
reply.getAdvice(true).put(Message.RECONNECT_FIELD, Message.RECONNECT_NONE_VALUE);
}
return reply;
}
protected ServerMessage.Mutable processReply(ServerSessionImpl session, ServerMessage.Mutable reply)
{
if (reply != null)
{
reply = getBayeux().extendReply(session, session, reply);
if (reply != null)
getBayeux().freeze(reply);
}
return reply;
}
protected void flush(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, boolean sendQueue, boolean startInterval, ServerMessage.Mutable... replies)
{
List<ServerMessage> messages = Collections.emptyList();
if (session != null)
{
boolean metaConnectDelivery = isMetaConnectDeliveryOnly() || session.isMetaConnectDeliveryOnly();
if (sendQueue && (startInterval || !metaConnectDelivery))
messages = session.takeQueue();
}
write(request, response, session, startInterval, messages, replies);
}
protected void resume(HttpServletRequest request, HttpServletResponse response, AsyncContext asyncContext, ServerSessionImpl session, ServerMessage.Mutable reply)
{
metaConnectResumed(request, response, asyncContext, session);
Map<String, Object> advice = session.takeAdvice(this);
if (advice != null)
reply.put(Message.ADVICE_FIELD, advice);
if (session.isDisconnected())
reply.getAdvice(true).put(Message.RECONNECT_FIELD, Message.RECONNECT_NONE_VALUE);
flush(request, response, session, true, true, processReply(session, reply));
}
public BayeuxContext getContext()
{
HttpServletRequest request = getCurrentRequest();
if (request != null)
return new HttpContext(request);
return null;
}
protected String findBrowserId(HttpServletRequest request)
{
Cookie[] cookies = request.getCookies();
if (cookies != null)
{
for (Cookie cookie : cookies)
{
if (_browserCookieName.equals(cookie.getName()))
return cookie.getValue();
}
}
return null;
}
protected String setBrowserId(HttpServletRequest request, HttpServletResponse response)
{
String browserId = Long.toHexString(request.getRemotePort()) +
Long.toString(getBayeux().randomLong(), 36) +
Long.toString(System.currentTimeMillis(), 36) +
Long.toString(request.getRemotePort(), 36);
Cookie cookie = new Cookie(_browserCookieName, browserId);
if (_browserCookieDomain != null)
cookie.setDomain(_browserCookieDomain);
cookie.setPath(_browserCookiePath);
cookie.setMaxAge(-1);
response.addCookie(cookie);
return browserId;
}
/**
* Increment the browser ID count.
*
*
* @param browserId the browser ID to increment the count for
* @param session the session that cause the browser ID increment
* @return true if the browser ID count is below the max sessions per browser value.
* If false is returned, the count is not incremented.
*/
protected boolean incBrowserId(String browserId, ServerSession session)
{
if (_maxSessionsPerBrowser < 0)
return true;
if (_maxSessionsPerBrowser == 0)
return false;
AtomicInteger count = _browserMap.get(browserId);
if (count == null)
{
AtomicInteger newCount = new AtomicInteger();
count = _browserMap.putIfAbsent(browserId, newCount);
if (count == null)
count = newCount;
}
// Increment
int sessions = count.incrementAndGet();
// If was zero, remove from the sweep
if (sessions == 1)
_browserSweep.remove(browserId);
boolean result = true;
if (sessions > _maxSessionsPerBrowser)
{
sessions = count.decrementAndGet();
result = false;
}
if (_logger.isDebugEnabled())
_logger.debug("> client {} {} sessions from {}", browserId, sessions, session);
return result;
}
protected void decBrowserId(String browserId, ServerSession session)
{
if (browserId == null)
return;
int sessions = -1;
AtomicInteger count = _browserMap.get(browserId);
if (count != null)
sessions = count.decrementAndGet();
if (sessions == 0)
_browserSweep.put(browserId, new AtomicInteger(0));
if (_logger.isDebugEnabled())
_logger.debug("< client {} {} sessions for {}", browserId, sessions, session);
}
protected void handleJSONParseException(HttpServletRequest request, HttpServletResponse response, String json, Throwable exception) throws IOException
{
try
{
_logger.warn("Could not parse JSON: " + json, exception);
response.sendError(HttpServletResponse.SC_BAD_REQUEST);
}
catch (IOException x)
{
_logger.trace("Could not send response error", x);
}
}
protected void error(HttpServletRequest request, HttpServletResponse response, AsyncContext asyncContext, int responseCode)
{
try
{
response.sendError(responseCode);
}
catch (Exception x)
{
_logger.trace("Could not send " + responseCode + " response", x);
}
finally
{
try
{
if (asyncContext != null)
asyncContext.complete();
}
catch (Exception x)
{
_logger.trace("Could not complete " + responseCode + " response", x);
}
}
}
protected ServerMessage.Mutable bayeuxServerHandle(ServerSessionImpl session, ServerMessage.Mutable message)
{
return getBayeux().handle(session, message);
}
protected void metaConnectSuspended(HttpServletRequest request, HttpServletResponse response, AsyncContext asyncContext, ServerSession session)
{
if (_logger.isDebugEnabled())
_logger.debug("Suspended request {}", request);
}
protected void metaConnectResumed(HttpServletRequest request, HttpServletResponse response, AsyncContext asyncContext, ServerSession session)
{
if (_logger.isDebugEnabled())
_logger.debug("Resumed request {}", request);
}
/**
* Sweeps the transport for old Browser IDs
*/
protected void sweep()
{
long now = System.currentTimeMillis();
long elapsed = now - _lastSweep;
if (_lastSweep > 0 && elapsed > 0)
{
// Calculate the maximum sweeps that a browser ID can be 0 as the
// maximum interval time divided by the sweep period, doubled for safety
int maxSweeps = (int)(2 * getMaxInterval() / elapsed);
for (Map.Entry<String, AtomicInteger> entry : _browserSweep.entrySet())
{
AtomicInteger count = entry.getValue();
// if the ID has been in the sweep map for 3 sweeps
if (count!=null && count.incrementAndGet() > maxSweeps)
{
String key = entry.getKey();
// remove it from both browser Maps
if (_browserSweep.remove(key) == count && _browserMap.get(key).get() == 0)
{
_browserMap.remove(key);
if (_logger.isDebugEnabled())
_logger.debug("Swept browserId {}", key);
}
}
}
}
_lastSweep = now;
}
private static class HttpContext implements BayeuxContext
{
final HttpServletRequest _request;
HttpContext(HttpServletRequest request)
{
_request = request;
}
public Principal getUserPrincipal()
{
return _request.getUserPrincipal();
}
public boolean isUserInRole(String role)
{
return _request.isUserInRole(role);
}
public InetSocketAddress getRemoteAddress()
{
return new InetSocketAddress(_request.getRemoteHost(), _request.getRemotePort());
}
public InetSocketAddress getLocalAddress()
{
return new InetSocketAddress(_request.getLocalName(), _request.getLocalPort());
}
public String getHeader(String name)
{
return _request.getHeader(name);
}
public List<String> getHeaderValues(String name)
{
return Collections.list(_request.getHeaders(name));
}
public String getParameter(String name)
{
return _request.getParameter(name);
}
public List<String> getParameterValues(String name)
{
return Arrays.asList(_request.getParameterValues(name));
}
public String getCookie(String name)
{
Cookie[] cookies = _request.getCookies();
if (cookies != null)
{
for (Cookie c : cookies)
{
if (name.equals(c.getName()))
return c.getValue();
}
}
return null;
}
public String getHttpSessionId()
{
HttpSession session = _request.getSession(false);
if (session != null)
return session.getId();
return null;
}
public Object getHttpSessionAttribute(String name)
{
HttpSession session = _request.getSession(false);
if (session != null)
return session.getAttribute(name);
return null;
}
public void setHttpSessionAttribute(String name, Object value)
{
HttpSession session = _request.getSession(false);
if (session != null)
session.setAttribute(name, value);
else
throw new IllegalStateException("!session");
}
public void invalidateHttpSession()
{
HttpSession session = _request.getSession(false);
if (session != null)
session.invalidate();
}
public Object getRequestAttribute(String name)
{
return _request.getAttribute(name);
}
private ServletContext getServletContext()
{
HttpSession s = _request.getSession(false);
if (s != null)
{
return s.getServletContext();
}
else
{
s = _request.getSession(true);
ServletContext servletContext = s.getServletContext();
s.invalidate();
return servletContext;
}
}
public Object getContextAttribute(String name)
{
return getServletContext().getAttribute(name);
}
public String getContextInitParameter(String name)
{
return getServletContext().getInitParameter(name);
}
public String getURL()
{
StringBuffer url = _request.getRequestURL();
String query = _request.getQueryString();
if (query != null)
url.append("?").append(query);
return url.toString();
}
}
public interface HttpScheduler extends Scheduler
{
public HttpServletRequest getRequest();
public HttpServletResponse getResponse();
public AsyncContext getAsyncContext();
}
protected abstract class LongPollScheduler implements Runnable, HttpScheduler, AsyncListener
{
private final HttpServletRequest request;
private final HttpServletResponse response;
private final AsyncContext asyncContext;
private final ServerSessionImpl session;
private final ServerMessage.Mutable reply;
private final String browserId;
private final org.eclipse.jetty.util.thread.Scheduler.Task task;
protected LongPollScheduler(HttpServletRequest request, HttpServletResponse response, AsyncContext asyncContext, ServerSessionImpl session, ServerMessage.Mutable reply, String browserId, long timeout)
{
this.request = request;
this.response = response;
this.asyncContext = asyncContext;
this.session = session;
this.reply = reply;
this.browserId = browserId;
asyncContext.addListener(this);
this.task = getBayeux().schedule(this, timeout);
}
@Override
public HttpServletRequest getRequest()
{
return request;
}
@Override
public HttpServletResponse getResponse()
{
return response;
}
@Override
public AsyncContext getAsyncContext()
{
return asyncContext;
}
public ServerSessionImpl getServerSession()
{
return session;
}
public ServerMessage.Mutable getMetaConnectReply()
{
return reply;
}
@Override
public void schedule()
{
if (cancelTimeout())
{
if (_logger.isDebugEnabled())
_logger.debug("Resuming /meta/connect after schedule");
resume();
}
}
@Override
public void cancel()
{
if (cancelTimeout())
{
if (_logger.isDebugEnabled())
_logger.debug("Duplicate /meta/connect, cancelling {}", reply);
error(HttpServletResponse.SC_REQUEST_TIMEOUT);
}
}
private boolean cancelTimeout()
{
return task.cancel();
}
@Override
public void run()
{
cancelTimeout();
session.setScheduler(null);
if (_logger.isDebugEnabled())
_logger.debug("Resuming /meta/connect after timeout");
resume();
}
private void resume()
{
decBrowserId(browserId, session);
dispatch();
}
@Override
public void onStartAsync(AsyncEvent event) throws IOException
{
}
@Override
public void onTimeout(AsyncEvent event) throws IOException
{
}
@Override
public void onComplete(AsyncEvent asyncEvent) throws IOException
{
}
@Override
public void onError(AsyncEvent event) throws IOException
{
error(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
}
protected abstract void dispatch();
protected void error(int code)
{
decBrowserId(browserId, session);
AbstractHttpTransport.this.error(getRequest(), getResponse(), getAsyncContext(), code);
}
}
}