GUAC-878: Generalize loading of WebSocket classes in WebSocketSupportLoader. Note that Jetty support is specific to Jetty 8. Update documentation.

This commit is contained in:
Michael Jumper
2014-10-10 13:53:30 -07:00
parent d3e625d0a3
commit b6f45c585f
5 changed files with 267 additions and 29 deletions

View File

@@ -142,7 +142,7 @@
<scope>runtime</scope>
</dependency>
<!-- Jetty servlet API (websocket) -->
<!-- Jetty 8 servlet API (websocket) -->
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-websocket</artifactId>

View File

@@ -30,8 +30,6 @@ import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import org.glyptodon.guacamole.GuacamoleException;
import org.glyptodon.guacamole.net.basic.GuacamoleClassLoader;
import org.glyptodon.guacamole.properties.BooleanGuacamoleProperty;
import org.glyptodon.guacamole.properties.GuacamoleProperties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@@ -44,17 +42,6 @@ import org.slf4j.LoggerFactory;
* not be available or needed if WebSocket is not desired, the 3.0 API is
* detected and invoked dynamically via reflection.
*
* Tests have shown that while WebSocket is negligibly more responsive than
* Guacamole's native HTTP tunnel, downstream performance is not yet a match.
* This may be because browser WebSocket implementations are not optimized for
* throughput, or it may be because servlet container WebSocket implementations
* are in their infancy, or it may be that OUR WebSocket-backed tunnel
* implementations are not efficient. Because of this, WebSocket support is
* disabled by default. To enable it, add the following property to
* your guacamole.properties:
*
* enable-websocket: true
*
* @author Michael Jumper
*/
public class WebSocketSupportLoader implements ServletContextListener {
@@ -65,16 +52,12 @@ public class WebSocketSupportLoader implements ServletContextListener {
private final Logger logger = LoggerFactory.getLogger(WebSocketSupportLoader.class);
/**
* Classname of the Jetty-specific WebSocket tunnel implementation.
* Classnames of all legacy (non-JSR) WebSocket tunnel implementations.
*/
private static final String JETTY_WEBSOCKET =
"org.glyptodon.guacamole.net.basic.websocket.jetty.BasicGuacamoleWebSocketTunnelServlet";
/**
* Classname of the Tomcat-specific WebSocket tunnel implementation.
*/
private static final String TOMCAT_WEBSOCKET =
"org.glyptodon.guacamole.net.basic.websocket.tomcat.BasicGuacamoleWebSocketTunnelServlet";
private static final String[] WEBSOCKET_CLASSES = {
"org.glyptodon.guacamole.net.basic.websocket.jetty8.BasicGuacamoleWebSocketTunnelServlet",
"org.glyptodon.guacamole.net.basic.websocket.tomcat.BasicGuacamoleWebSocketTunnelServlet"
};
private boolean loadWebSocketTunnel(ServletContext context, String classname) {
@@ -101,7 +84,6 @@ public class WebSocketSupportLoader implements ServletContextListener {
// If we succesfully load and register the WebSocket tunnel servlet,
// WebSocket is supported.
logger.info("WebSocket support found and loaded.");
return true;
}
@@ -146,12 +128,16 @@ public class WebSocketSupportLoader implements ServletContextListener {
@Override
public void contextInitialized(ServletContextEvent sce) {
// Try to load websocket support for Jetty
if (loadWebSocketTunnel(sce.getServletContext(), JETTY_WEBSOCKET))
return;
// Try to load each WebSocket tunnel in sequence
for (String classname : WEBSOCKET_CLASSES) {
if (loadWebSocketTunnel(sce.getServletContext(), classname)) {
logger.info("Legacy (non-JSR) WebSocket support loaded: {}", classname);
return;
}
}
// Failing that, try to load websocket support for Tomcat
loadWebSocketTunnel(sce.getServletContext(), TOMCAT_WEBSOCKET);
// No legacy WebSocket support found (usually good)
logger.debug("Legacy WebSocket support NOT loaded.");
}

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@@ -0,0 +1,44 @@
/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package org.glyptodon.guacamole.net.basic.websocket.jetty8;
import javax.servlet.http.HttpServletRequest;
import org.glyptodon.guacamole.GuacamoleException;
import org.glyptodon.guacamole.net.GuacamoleTunnel;
import org.glyptodon.guacamole.net.basic.BasicTunnelRequestUtility;
import org.glyptodon.guacamole.net.basic.HTTPTunnelRequest;
/**
* Tunnel servlet implementation which uses WebSocket as a tunnel backend,
* rather than HTTP, properly parsing connection IDs included in the connection
* request.
*/
public class BasicGuacamoleWebSocketTunnelServlet extends GuacamoleWebSocketTunnelServlet {
@Override
protected GuacamoleTunnel doConnect(HttpServletRequest request)
throws GuacamoleException {
return BasicTunnelRequestUtility.createTunnel(new HTTPTunnelRequest(request));
}
}

View File

@@ -0,0 +1,181 @@
/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package org.glyptodon.guacamole.net.basic.websocket.jetty8;
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import org.glyptodon.guacamole.GuacamoleException;
import org.glyptodon.guacamole.io.GuacamoleReader;
import org.glyptodon.guacamole.io.GuacamoleWriter;
import org.glyptodon.guacamole.net.GuacamoleTunnel;
import org.eclipse.jetty.websocket.WebSocket;
import org.eclipse.jetty.websocket.WebSocket.Connection;
import org.eclipse.jetty.websocket.WebSocketServlet;
import org.glyptodon.guacamole.GuacamoleClientException;
import org.glyptodon.guacamole.protocol.GuacamoleStatus;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A WebSocketServlet partial re-implementation of GuacamoleTunnelServlet.
*
* @author Michael Jumper
*/
public abstract class GuacamoleWebSocketTunnelServlet extends WebSocketServlet {
/**
* Logger for this class.
*/
private static final Logger logger = LoggerFactory.getLogger(GuacamoleWebSocketTunnelServlet.class);
/**
* The default, minimum buffer size for instructions.
*/
private static final int BUFFER_SIZE = 8192;
/**
* Sends the given status on the given WebSocket connection and closes the
* connection.
*
* @param connection The WebSocket connection to close.
* @param guac_status The status to send.
*/
public static void closeConnection(Connection connection,
GuacamoleStatus guac_status) {
connection.close(guac_status.getWebSocketCode(),
Integer.toString(guac_status.getGuacamoleStatusCode()));
}
@Override
public WebSocket doWebSocketConnect(HttpServletRequest request, String protocol) {
// Get tunnel
final GuacamoleTunnel tunnel;
try {
tunnel = doConnect(request);
}
catch (GuacamoleException e) {
logger.error("Error connecting WebSocket tunnel.", e);
return null;
}
// Return new WebSocket which communicates through tunnel
return new WebSocket.OnTextMessage() {
@Override
public void onMessage(String string) {
GuacamoleWriter writer = tunnel.acquireWriter();
// Write message received
try {
writer.write(string.toCharArray());
}
catch (GuacamoleException e) {
logger.debug("Tunnel write failed.", e);
}
tunnel.releaseWriter();
}
@Override
public void onOpen(final Connection connection) {
Thread readThread = new Thread() {
@Override
public void run() {
StringBuilder buffer = new StringBuilder(BUFFER_SIZE);
GuacamoleReader reader = tunnel.acquireReader();
char[] readMessage;
try {
try {
// Attempt to read
while ((readMessage = reader.read()) != null) {
// Buffer message
buffer.append(readMessage);
// Flush if we expect to wait or buffer is getting full
if (!reader.available() || buffer.length() >= BUFFER_SIZE) {
connection.sendMessage(buffer.toString());
buffer.setLength(0);
}
}
// No more data
closeConnection(connection, GuacamoleStatus.SUCCESS);
}
// Catch any thrown guacamole exception and attempt
// to pass within the WebSocket connection, logging
// each error appropriately.
catch (GuacamoleClientException e) {
logger.warn("Client request rejected: {}", e.getMessage());
closeConnection(connection, e.getStatus());
}
catch (GuacamoleException e) {
logger.error("Internal server error.", e);
closeConnection(connection, e.getStatus());
}
}
catch (IOException e) {
logger.debug("Tunnel read failed due to I/O error.", e);
}
}
};
readThread.start();
}
@Override
public void onClose(int i, String string) {
try {
tunnel.close();
}
catch (GuacamoleException e) {
logger.debug("Unable to close WebSocket tunnel.", e);
}
}
};
}
protected abstract GuacamoleTunnel doConnect(HttpServletRequest request)
throws GuacamoleException;
}

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@@ -0,0 +1,27 @@
/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/**
* Jetty 8 WebSocket tunnel implementation. The classes here require Jetty 8.
*/
package org.glyptodon.guacamole.net.basic.websocket.jetty8;