JsrWebSocketFilter.java
/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 io.undertow.websockets.jsr;
import static io.undertow.websockets.jsr.ServerWebSocketContainer.WebSocketHandshakeHolder;
import java.io.IOException;
import java.io.ObjectStreamException;
import java.io.Serial;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArraySet;
import jakarta.servlet.Filter;
import jakarta.servlet.FilterChain;
import jakarta.servlet.FilterConfig;
import jakarta.servlet.ServletException;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.ServletResponse;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;
import jakarta.servlet.http.HttpSessionEvent;
import jakarta.servlet.http.HttpSessionListener;
import jakarta.websocket.CloseReason;
import jakarta.websocket.server.ServerContainer;
import org.xnio.ChannelListener;
import org.xnio.StreamConnection;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.HttpUpgradeListener;
import io.undertow.server.session.Session;
import io.undertow.servlet.handlers.ServletRequestContext;
import io.undertow.servlet.spec.HttpSessionImpl;
import io.undertow.servlet.websockets.ServletWebSocketHttpExchange;
import io.undertow.util.Headers;
import io.undertow.util.PathTemplateMatcher;
import io.undertow.util.StatusCodes;
import io.undertow.websockets.WebSocketConnectionCallback;
import io.undertow.websockets.core.WebSocketChannel;
import io.undertow.websockets.core.WebSockets;
import io.undertow.websockets.core.protocol.Handshake;
import io.undertow.websockets.jsr.handshake.HandshakeUtil;
/**
* Filter that provides HTTP upgrade functionality. This should be run after all user filters, but before any servlets.
* <p>
* The use of a filter rather than a servlet allows for normal HTTP requests to be served from the same location
* as a web socket endpoint if no upgrade header is found.
* <p>
*
* @author Stuart Douglas
*/
public class JsrWebSocketFilter implements Filter {
private WebSocketConnectionCallback callback;
private PathTemplateMatcher<WebSocketHandshakeHolder> pathTemplateMatcher;
private Set<WebSocketChannel> peerConnections;
private ServerWebSocketContainer container;
private static final String SESSION_ATTRIBUTE = "io.undertow.websocket.current-connections";
@Override
public void init(final FilterConfig filterConfig) throws ServletException {
peerConnections = Collections.newSetFromMap(new ConcurrentHashMap<WebSocketChannel, Boolean>());
container = (ServerWebSocketContainer) filterConfig.getServletContext().getAttribute(ServerContainer.class.getName());
container.deploymentComplete();
pathTemplateMatcher = new PathTemplateMatcher<>();
WebSocketDeploymentInfo info = (WebSocketDeploymentInfo)filterConfig.getServletContext().getAttribute(WebSocketDeploymentInfo.ATTRIBUTE_NAME);
for (ConfiguredServerEndpoint endpoint : container.getConfiguredServerEndpoints()) {
if (info == null || info.getExtensions().isEmpty()) {
pathTemplateMatcher.add(endpoint.getPathTemplate(), ServerWebSocketContainer.handshakes(endpoint));
} else {
pathTemplateMatcher.add(endpoint.getPathTemplate(), ServerWebSocketContainer.handshakes(endpoint, info.getExtensions()));
}
}
this.callback = new EndpointSessionHandler(container);
}
@Override
public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse resp = (HttpServletResponse) response;
if (req.getHeader(Headers.UPGRADE_STRING) != null) {
final ServletWebSocketHttpExchange facade = new ServletWebSocketHttpExchange(req, resp, peerConnections);
String path;
if (req.getPathInfo() == null) {
path = req.getServletPath();
} else {
path = req.getServletPath() + req.getPathInfo();
}
if (!path.startsWith("/")) {
path = "/" + path;
}
PathTemplateMatcher.PathMatchResult<WebSocketHandshakeHolder> matchResult = pathTemplateMatcher.match(path);
if (matchResult != null) {
Handshake handshaker = null;
for (Handshake method : matchResult.getValue().handshakes) {
if (method.matches(facade)) {
handshaker = method;
break;
}
}
if (handshaker != null) {
if(container.isClosed()) {
resp.sendError(StatusCodes.SERVICE_UNAVAILABLE);
return;
}
facade.putAttachment(HandshakeUtil.PATH_PARAMS, matchResult.getParameters());
facade.putAttachment(HandshakeUtil.PRINCIPAL, req.getUserPrincipal());
final Handshake selected = handshaker;
ServletRequestContext src = ServletRequestContext.requireCurrent();
final HttpSessionImpl session = src.getCurrentServletContext().getSession(src.getExchange(), false);
facade.upgradeChannel(new HttpUpgradeListener() {
@Override
public void handleUpgrade(StreamConnection streamConnection, HttpServerExchange exchange) {
HandshakeUtil.propagate(exchange, facade);
WebSocketChannel channel = selected.createChannel(facade, streamConnection, facade.getBufferPool());
peerConnections.add(channel);
if (session != null) {
Session unwrappedSession = unwrap(session);
Collection<WebSocketChannel> channels = requireWebSocketChannels(unwrappedSession);
channels.add(channel);
channel.addCloseTask(new ChannelListener<WebSocketChannel>() {
@Override
public void handleEvent(WebSocketChannel channel) {
channels.remove(channel);
}
});
}
callback.onConnect(facade, channel);
}
});
handshaker.handshake(facade);
return;
}
}
}
chain.doFilter(request, response);
}
@Override
public void destroy() {
}
@SuppressWarnings("removal")
static Session unwrap(HttpSession session) {
return (System.getSecurityManager() == null) ? ((HttpSessionImpl) session).getSession() : java.security.AccessController.doPrivileged(new HttpSessionImpl.UnwrapSessionAction(session));
}
static Collection<WebSocketChannel> requireWebSocketChannels(Session session) {
Collection<WebSocketChannel> channels = getWebSocketChannels(session);
if (channels == null) {
// This should not be the case, but handle defensively
synchronized (session.getId()) {
channels = getWebSocketChannels(session);
if (channels == null) {
channels = new WebSocketChannels();
session.setAttribute(SESSION_ATTRIBUTE, channels);
}
}
}
return channels;
}
@SuppressWarnings("unchecked")
static Collection<WebSocketChannel> getWebSocketChannels(Session session) {
return (Collection<WebSocketChannel>) session.getAttribute(SESSION_ATTRIBUTE);
}
public static class LogoutListener implements HttpSessionListener {
@Override
public void sessionCreated(HttpSessionEvent event) {
// Avoid the need to instrument putIfAbsent semantics by creating the WebSocketChannel collection on session creation
unwrap(event.getSession()).setAttribute(SESSION_ATTRIBUTE, new WebSocketChannels());
}
@Override
public void sessionDestroyed(HttpSessionEvent event) {
Collection<WebSocketChannel> channels = getWebSocketChannels(unwrap(event.getSession()));
if (channels != null) {
for (WebSocketChannel channel : channels) {
WebSockets.sendClose(CloseReason.CloseCodes.VIOLATED_POLICY.getCode(), "", channel, null);
}
}
}
}
public static class WebSocketChannels extends CopyOnWriteArraySet<WebSocketChannel> {
@Serial
private static final long serialVersionUID = 1858641678165439774L;
private Object writeReplace() throws ObjectStreamException {
// WebSocketChannel is not serializable - persist as an empty collection
return this.isEmpty() ? this : new WebSocketChannels();
}
}
}