org.cometd.server.transport.AbstractHttpTransport Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2019 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.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicBoolean;
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;
/**
* HTTP ServerTransport base class, used by ServerTransports that use
* HTTP as transport or to initiate a transport connection.
*/
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 BROWSER_COOKIE_SECURE_OPTION = "browserCookieSecure";
public final static String BROWSER_COOKIE_HTTP_ONLY_OPTION = "browserCookieHttpOnly";
public final static String BROWSER_COOKIE_SAME_SITE_OPTION = "browserCookieSameSite";
public final static String MAX_SESSIONS_PER_BROWSER_OPTION = "maxSessionsPerBrowser";
public final static String HTTP2_MAX_SESSIONS_PER_BROWSER_OPTION = "http2MaxSessionsPerBrowser";
public final static String MULTI_SESSION_INTERVAL_OPTION = "multiSessionInterval";
public final static String TRUST_CLIENT_SESSION = "trustClientSession";
protected final Logger _logger = LoggerFactory.getLogger(getClass());
private final ThreadLocal _currentRequest = new ThreadLocal<>();
private final Map> _sessions = new HashMap<>();
private final ConcurrentMap _browserMap = new ConcurrentHashMap<>();
private final Map _browserSweep = new ConcurrentHashMap<>();
private String _browserCookieName;
private String _browserCookieDomain;
private String _browserCookiePath;
private boolean _browserCookieSecure;
private boolean _browserCookieHttpOnly;
private String _browserCookieSameSite;
private int _maxSessionsPerBrowser;
private int _http2MaxSessionsPerBrowser;
private long _multiSessionInterval;
private boolean _trustClientSession;
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, "/");
_browserCookieSecure = getOption(BROWSER_COOKIE_SECURE_OPTION, false);
_browserCookieHttpOnly = getOption(BROWSER_COOKIE_HTTP_ONLY_OPTION, true);
_browserCookieSameSite = getOption(BROWSER_COOKIE_SAME_SITE_OPTION, null);
_maxSessionsPerBrowser = getOption(MAX_SESSIONS_PER_BROWSER_OPTION, 1);
_http2MaxSessionsPerBrowser = getOption(HTTP2_MAX_SESSIONS_PER_BROWSER_OPTION, -1);
_multiSessionInterval = getOption(MULTI_SESSION_INTERVAL_OPTION, 2000);
_trustClientSession = getOption(TRUST_CLIENT_SESSION, false);
}
protected long getMultiSessionInterval() {
return _multiSessionInterval;
}
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, long timeout);
protected abstract void write(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, boolean scheduleExpiration, List messages, ServerMessage.Mutable[] replies);
protected void processMessages(HttpServletRequest request, HttpServletResponse response, ServerMessage.Mutable[] messages) throws IOException {
if (messages.length == 0) {
throw new IOException();
}
Collection sessions = findCurrentSessions(request);
ServerMessage.Mutable message = messages[0];
ServerSessionImpl session = findSession(sessions, message);
if (_logger.isDebugEnabled()) {
_logger.debug("Processing {} messages for session {}", messages.length, session);
}
boolean batch = session != null && !Channel.META_CONNECT.equals(message.getChannel());
if (batch) {
session.startBatch();
}
boolean sendQueue = false;
boolean sendReplies = false;
boolean scheduleExpiration = false;
try {
for (int i = 0; i < messages.length; ++i) {
message = messages[i];
if (_logger.isDebugEnabled()) {
_logger.debug("Processing {}", message);
}
switch (message.getChannel()) {
case Channel.META_HANDSHAKE: {
if (messages.length > 1) {
throw new IOException();
}
ServerMessage.Mutable reply = processMetaHandshake(request, response, session, message);
messages[i] = reply = processReply(session, reply);
sendQueue = allowMessageDeliveryDuringHandshake(session) && reply != null && reply.isSuccessful();
sendReplies = reply != null;
scheduleExpiration = true;
break;
}
case Channel.META_CONNECT: {
boolean canSuspend = messages.length == 1;
ServerMessage.Mutable reply = processMetaConnect(request, response, session, message, canSuspend);
messages[i] = reply = processReply(session, reply);
sendQueue = !canSuspend || reply != null;
sendReplies = sendQueue;
scheduleExpiration = true;
break;
}
default: {
ServerMessage.Mutable reply = bayeuxServerHandle(session, message);
messages[i] = reply = processReply(session, reply);
boolean metaConnectDelivery = isMetaConnectDeliveryOnly() || session != null && session.isMetaConnectDeliveryOnly();
if (!metaConnectDelivery) {
sendQueue = true;
}
if (reply != null) {
sendReplies = true;
}
// Leave scheduleExpiration unchanged.
break;
}
}
}
if (sendQueue || sendReplies) {
flush(request, response, session, sendQueue, scheduleExpiration, messages);
}
} finally {
if (batch) {
session.endBatch();
}
}
}
protected ServerSessionImpl findSession(Collection sessions, ServerMessage.Mutable message) {
if (Channel.META_HANDSHAKE.equals(message.getChannel())) {
ServerSessionImpl session = getBayeux().newServerSession();
session.setAllowMessageDeliveryDuringHandshake(isAllowMessageDeliveryDuringHandshake());
return session;
}
// Is there an existing, trusted, session ?
String clientId = message.getClientId();
if (sessions != null) {
if (clientId != null) {
for (ServerSessionImpl session : sessions) {
if (session.getId().equals(clientId)) {
return session;
}
}
}
}
if (_trustClientSession) {
return (ServerSessionImpl)getBayeux().getSession(clientId);
}
return null;
}
protected Collection findCurrentSessions(HttpServletRequest request) {
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
if (_browserCookieName.equals(cookie.getName())) {
synchronized (_sessions) {
return _sessions.get(cookie.getValue());
}
}
}
}
return null;
}
protected ServerMessage.Mutable processMetaHandshake(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, ServerMessage.Mutable message) {
ServerMessage.Mutable reply = bayeuxServerHandle(session, message);
if (reply.isSuccessful()) {
String id = findBrowserId(request);
if (id == null) {
id = setBrowserId(request, response);
}
final String browserId = id;
session.setBrowserId(browserId);
synchronized (_sessions) {
Collection sessions = _sessions.get(browserId);
if (sessions == null) {
// The list is modified inside sync blocks, but
// iterated outside, so it must be concurrent.
sessions = new CopyOnWriteArrayList<>();
_sessions.put(browserId, sessions);
}
sessions.add(session);
}
session.addListener(new ServerSession.RemoveListener() {
@Override
public void removed(ServerSession session, boolean timeout) {
synchronized (_sessions) {
Collection sessions = _sessions.get(browserId);
sessions.remove(session);
if (sessions.isEmpty()) {
_sessions.remove(browserId);
}
}
}
});
}
return reply;
}
protected ServerMessage.Mutable processMetaConnect(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, ServerMessage.Mutable message, boolean canSuspend) {
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 (session != null) {
boolean maySuspend = !session.shouldSchedule();
if (canSuspend && maySuspend && reply.isSuccessful()) {
// Detect if we have multiple sessions from the same browser.
boolean allowSuspendConnect = incBrowserId(session, isHTTP2(request));
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, timeout);
metaConnectSuspended(request, response, scheduler.getAsyncContext(), session);
// Setting the scheduler may resume the /meta/connect
session.setScheduler(scheduler);
reply = null;
} else {
decBrowserId(session, isHTTP2(request));
}
} else {
// There are multiple sessions from the same browser
Map advice = reply.getAdvice(true);
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 boolean isHTTP2(HttpServletRequest request) {
return "HTTP/2.0".equals(request.getProtocol());
}
protected void flush(HttpServletRequest request, HttpServletResponse response, ServerSessionImpl session, boolean sendQueue, boolean scheduleExpiration, ServerMessage.Mutable... replies) {
List messages = Collections.emptyList();
if (sendQueue && session != null) {
messages = session.takeQueue();
}
write(request, response, session, scheduleExpiration, messages, replies);
}
protected void resume(HttpServletRequest request, HttpServletResponse response, AsyncContext asyncContext, ServerSessionImpl session, ServerMessage.Mutable reply) {
metaConnectResumed(request, response, asyncContext, session);
Map 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));
}
@Override
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) {
StringBuilder builder = new StringBuilder();
while (builder.length() < 16) {
builder.append(Long.toString(getBayeux().randomLong(), 36));
}
builder.setLength(16);
String browserId = builder.toString();
// Need to support the SameSite attribute so build the cookie manually.
builder.setLength(0);
builder.append(_browserCookieName).append("=").append(browserId);
if (_browserCookieDomain != null) {
builder.append("; Domain=").append(_browserCookieDomain);
}
if (_browserCookiePath != null) {
builder.append("; Path=").append(_browserCookiePath);
}
if (_browserCookieHttpOnly) {
builder.append("; HttpOnly");
}
if (request.isSecure() && _browserCookieSecure) {
builder.append("; Secure");
}
if (_browserCookieSameSite != null) {
builder.append("; SameSite=").append(_browserCookieSameSite);
}
response.addHeader("Set-Cookie", builder.toString());
return browserId;
}
/**
* Increments the count of sessions for the given browser identifier.
*
* @param session the session that increments the count
* @param http2 whether the HTTP protocol is HTTP/2
* @return true if the count is below the max sessions per browser value.
* If false is returned, the count is not incremented.
*
* @see #decBrowserId(ServerSessionImpl, boolean)
*/
protected boolean incBrowserId(ServerSessionImpl session, boolean http2) {
int maxSessionsPerBrowser = http2 ? _http2MaxSessionsPerBrowser : _maxSessionsPerBrowser;
if (maxSessionsPerBrowser < 0) {
return true;
} else if (maxSessionsPerBrowser == 0) {
return false;
}
String browserId = session.getBrowserId();
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(ServerSessionImpl session, boolean http2) {
int maxSessionsPerBrowser = http2 ? _http2MaxSessionsPerBrowser : _maxSessionsPerBrowser;
String browserId = session.getBrowserId();
if (maxSessionsPerBrowser <= 0 || 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 {
_logger.warn("Could not parse JSON: " + json, exception);
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
}
protected AsyncContext getAsyncContext(HttpServletRequest request) {
try {
return request.getAsyncContext();
} catch (Throwable x) {
if (_logger.isDebugEnabled()) {
_logger.debug("Could not retrieve AsyncContext for " + request, x);
}
return null;
}
}
protected void error(HttpServletRequest request, HttpServletResponse response, AsyncContext asyncContext, int responseCode) {
try {
response.setStatus(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
*/
@Override
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 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;
}
@Override
public Principal getUserPrincipal() {
return _request.getUserPrincipal();
}
@Override
public boolean isUserInRole(String role) {
return _request.isUserInRole(role);
}
@Override
public InetSocketAddress getRemoteAddress() {
return new InetSocketAddress(_request.getRemoteHost(), _request.getRemotePort());
}
@Override
public InetSocketAddress getLocalAddress() {
return new InetSocketAddress(_request.getLocalName(), _request.getLocalPort());
}
@Override
public String getHeader(String name) {
return _request.getHeader(name);
}
@Override
public List getHeaderValues(String name) {
return Collections.list(_request.getHeaders(name));
}
@Override
public String getParameter(String name) {
return _request.getParameter(name);
}
@Override
public List getParameterValues(String name) {
return Arrays.asList(_request.getParameterValues(name));
}
@Override
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;
}
@Override
public String getHttpSessionId() {
HttpSession session = _request.getSession(false);
if (session != null) {
return session.getId();
}
return null;
}
@Override
public Object getHttpSessionAttribute(String name) {
HttpSession session = _request.getSession(false);
if (session != null) {
return session.getAttribute(name);
}
return null;
}
@Override
public void setHttpSessionAttribute(String name, Object value) {
HttpSession session = _request.getSession(false);
if (session != null) {
session.setAttribute(name, value);
} else {
throw new IllegalStateException("!session");
}
}
@Override
public void invalidateHttpSession() {
HttpSession session = _request.getSession(false);
if (session != null) {
session.invalidate();
}
}
@Override
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;
}
}
@Override
public Object getContextAttribute(String name) {
return getServletContext().getAttribute(name);
}
@Override
public String getContextInitParameter(String name) {
return getServletContext().getInitParameter(name);
}
@Override
public String getURL() {
StringBuffer url = _request.getRequestURL();
String query = _request.getQueryString();
if (query != null) {
url.append("?").append(query);
}
return url.toString();
}
@Override
public List getLocales() {
return Collections.list(_request.getLocales());
}
}
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 org.eclipse.jetty.util.thread.Scheduler.Task task;
private final AtomicBoolean cancel;
protected LongPollScheduler(HttpServletRequest request, HttpServletResponse response, AsyncContext asyncContext, ServerSessionImpl session, ServerMessage.Mutable reply, long timeout) {
this.request = request;
this.response = response;
this.asyncContext = asyncContext;
this.session = session;
this.reply = reply;
asyncContext.addListener(this);
this.task = getBayeux().schedule(this, timeout);
this.cancel = new AtomicBoolean();
}
@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_INTERNAL_SERVER_ERROR);
}
}
private boolean cancelTimeout() {
// Cannot rely on the return value of task.cancel()
// since it may be invoked when the task is in run()
// where cancellation is not possible (it's too late).
boolean cancelled = cancel.compareAndSet(false, true);
task.cancel();
return cancelled;
}
@Override
public void run() {
if (cancelTimeout()) {
session.setScheduler(null);
if (_logger.isDebugEnabled()) {
_logger.debug("Resuming /meta/connect after timeout");
}
resume();
}
}
private void resume() {
decBrowserId(session, isHTTP2(request));
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(session, isHTTP2(request));
AbstractHttpTransport.this.error(getRequest(), getResponse(), getAsyncContext(), code);
}
}
}
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