/*
* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.stream.Stream;
import static java.lang.StackWalker.Option.RETAIN_CLASS_REFERENCE;
/**
* A base dummy ldap server.
*
* For any ldap tests which required a simple dummy server to support the
* test, may use this server directly with specifying ConnectionHandler,
* SessionHandler/RequestHandler, or extends to build more complex server logic.
*
* This server already extends Thread and implements AutoCloseable, so it can
* be started in thread and integrated with try-with-resources
*
* To initiate a instance of this server, valid ServerSocket could be supplied,
* it will allow the flexibility for listening address/port customization
* and SSL usage, for default no parameter constructor, a ServerSocket which
* listen on loopback address will be created.
*
* To use this dummy server in test, user could customize the processing logic
* in three level with below handler interface.
* -ConnectionHandler provide connection level handling, server will hand
* over accepted socket and processing thread to handler.
* By default, DefaultConnectionHandler will be used if no
* specified, it reads full ldap request message then
* pass it to RequestHandler instance which returned by
* SessionHandler per session.
*
* -SessionHandler provide session level handling when DefaultConnectionHandler
* been used, it's to retrieve RequestHandler instance of
* current session.
* For most of tests, only one session need to be handled
* on server or all ldap request could be handled by same
* logic whatever current session is, user can use
* setCommonRequestHandler to setup one single session
* handler which will always return given RequestHandler
* instance.
*
* -RequestHandler provide ldap message request handling when
* DefaultConnectionHandler been used.
*
* @see ConnectionHandler
* @see SessionHandler
* @see RequestHandler
*/
public class BaseLdapServer extends Thread implements AutoCloseable {
private volatile boolean isRunning;
private final List<Socket> socketList = new ArrayList<>();
private ServerSocket serverSocket;
private ExecutorService workingPool;
private ConnectionHandler connectionHandler;
private SessionHandler sessionHandler;
enum DebugLevel {
FULL, // all debug message will be printed
NONE, // none of debug message will be printed
CUSTOMIZE // only specified class debug message will be printed
}
private StackWalker stackWalker = null;
private DebugLevel debugLevel = DebugLevel.NONE;
private Set<Class<?>> debugOptions = new HashSet<>();
/**
* BaseLdapServer overload default constructor.
*
* @throws IOException if an I/O error occurs when opening the socket.
*/
public BaseLdapServer() throws IOException {
this(new ServerSocket(0, 0, InetAddress.getLoopbackAddress()));
}
/**
* BaseLdapServer constructor with given server socket and specify whether
* use daemon for each accept connection handling thread.
*
* @param serverSocket given server socket
*/
public BaseLdapServer(ServerSocket serverSocket) {
this.serverSocket = Objects.requireNonNull(serverSocket);
workingPool = Executors.newCachedThreadPool();
try {
stackWalker = StackWalker.getInstance(RETAIN_CLASS_REFERENCE);
} catch (SecurityException se) {
// just ignore
}
}
@Override
public void run() {
if (getConnectionHandler() == null) {
debug("INFO: No connection handler been specified, try default.");
connectionHandler = new DefaultConnectionHandler();
}
debug("INFO: Using connection handler : " + getConnectionHandler()
.getClass().getName());
debug("INFO: LdapServer running and listening on port " + getPort());
try {
while (isRunning) {
Socket socket = serverSocket.accept();
debug("INFO: Accept new connection " + socket);
synchronized (socketList) {
socketList.add(socket);
}
workingPool.submit(() -> getConnectionHandler()
.handleConnection(socket));
}
} catch (IOException | RejectedExecutionException e) {
if (isRunning) {
throw new RuntimeException(e);
} else {
debug("INFO: Server exit.");
}
}
}
/*
* Override Thread.start()
*/
@Override
public synchronized void start() {
isRunning = true;
super.start();
}
/**
* Start Server thread and return itself for method chaining
*
* @return current server instance
*/
@SuppressWarnings("unchecked")
public <T extends BaseLdapServer> T startServer() {
start();
return (T) this;
}
/**
* Stop server.
*/
public void stopServer() {
debug("INFO: Stopping Server.");
isRunning = false;
workingPool.shutdown();
cleanupClosableRes(serverSocket);
// let's cleanup thread pool
synchronized (socketList) {
socketList.forEach(BaseLdapServer::cleanupClosableRes);
}
try {
if (!workingPool.awaitTermination(10, TimeUnit.SECONDS)) {
workingPool.shutdownNow();
}
} catch (InterruptedException e) {
workingPool.shutdownNow();
Thread.currentThread().interrupt();
}
}
/**
* Return local port which server is listening.
*
* @return port which server is listening
*/
public int getPort() {
if (serverSocket != null) {
return serverSocket.getLocalPort();
} else {
return -1;
}
}
/**
* Return flag to indicate whether current server is running.
*
* @return <tt>true</tt> if current server is running.
*/
public boolean isRunning() {
return isRunning;
}
/**
* Return ConnectionHandler instance
*
* @return ConnectionHandler instance
* @see ConnectionHandler
*/
ConnectionHandler getConnectionHandler() {
return connectionHandler;
}
/**
* Set ConnectionHandler when server is not running.
*
* @param connHandler ConnectionHandler instance
* @return current server instance for method chaining
*/
@SuppressWarnings("unchecked")
public <T extends BaseLdapServer> T setConnectionHandler(
ConnectionHandler connHandler) {
if (!isRunning) {
connectionHandler = connHandler;
}
return (T) this;
}
/**
* Return SessionHandler instance
*
* @return SessionHandler instance
* @see SessionHandler
*/
SessionHandler getSessionHandler() {
return sessionHandler;
}
/**
* Set SessionHandler when server is not running.
*
* @param sessionHandler given SessionHandler
* @return current server instance for method chaining
*/
@SuppressWarnings("unchecked")
public <T extends BaseLdapServer> T setSessionHandler(
SessionHandler sessionHandler) {
if (!isRunning) {
this.sessionHandler = sessionHandler;
}
return (T) this;
}
/**
* Set one common RequestHandler, it will be used to handle all requests
* whatever current session is.
*
* For most of tests, server only need to handle one session, use this
* method will create stateless session handler with given request handler.
*
* @param requestHandler RequestHandler instance
* @return current server instance for method chaining
*/
@SuppressWarnings("unchecked")
public <T extends BaseLdapServer> T setCommonRequestHandler(
RequestHandler requestHandler) {
if (!isRunning) {
// ignore any session, always return fixed request handler
setSessionHandler(socket -> requestHandler);
}
return (T) this;
}
@Override
public void close() {
stopServer();
}
/**
* Cleanup any given closable resource
*
* @param res given closable resource
*/
static void cleanupClosableRes(Closeable res) {
if (res != null) {
try {
res.close();
} catch (IOException e) {
// ignore
}
}
}
/**
* Set debug level to specify which kinds of debug message will be printed.
*
* @param debugLevel given debug level
* @param opts given opts if debug level is DebugLevel.CUSTOMIZE
* @return current server instance for method chaining
*/
@SuppressWarnings("unchecked")
public <T extends BaseLdapServer> T setDebugLevel(DebugLevel debugLevel,
Class<?>... opts) {
Objects.requireNonNull(debugLevel);
if (!isRunning) {
this.debugLevel = debugLevel;
if (debugLevel == DebugLevel.CUSTOMIZE) {
debugOptions.clear();
Stream.of(opts).filter(Objects::nonNull)
.forEach(debugOptions::add);
}
}
return (T) this;
}
/**
* Print given message if debug enabled.
*
* @param message given message to print
*/
void debug(String message) {
switch (debugLevel) {
case FULL:
System.out.println((stackWalker != null ?
stackWalker.getCallerClass().getName() :
"") + ": " + message);
break;
case CUSTOMIZE:
if (stackWalker != null) {
if (debugOptions.contains(stackWalker.getCallerClass())) {
System.out.println(
stackWalker.getCallerClass().getName() + ": "
+ message);
}
}
break;
case NONE:
default:
break;
}
}
/**
* Default connection handler implementation.
*/
class DefaultConnectionHandler implements ConnectionHandler {
@Override
public void handleConnection(Socket socket) {
try (socket;
OutputStream out = socket.getOutputStream();
InputStream in = socket.getInputStream()) {
byte[] inBuffer = new byte[1024];
int count;
byte[] request;
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int msgLen = -1;
while ((count = in.read(inBuffer)) > 0) {
buffer.write(inBuffer, 0, count);
if (msgLen <= 0) {
msgLen = getMessageLength(buffer.toByteArray());
}
if (msgLen > 0 && buffer.size() >= msgLen) {
if (buffer.size() > msgLen) {
byte[] tmpBuffer = buffer.toByteArray();
request = Arrays.copyOf(tmpBuffer, msgLen);
buffer.reset();
buffer.write(tmpBuffer, msgLen,
tmpBuffer.length - msgLen);
} else {
request = buffer.toByteArray();
buffer.reset();
}
msgLen = -1;
} else {
debug("INFO: request msg not complete, received "
+ buffer.size() + ", expected " + msgLen);
continue;
}
if (getSessionHandler() != null) {
var handler = getSessionHandler()
.getRequestHandler(socket);
if (handler != null) {
debug("INFO: Process request. Session handler : "
+ getSessionHandler()
+ ", Request handler : " + handler);
handler.handleRequest(new LdapMessage(request),
out);
} else {
debug("WARNING: no valid request handler returned from "
+ getSessionHandler() + ", " + socket);
}
} else {
debug("WARNING: no valid session handler been specified, discard request.");
}
}
debug("INFO: Connection Handler exit.");
} catch (IOException e) {
if (!isRunning()) {
debug("INFO: Connection Handler exit : " + e.getMessage());
} else {
e.printStackTrace();
}
}
}
private int getMessageLength(byte[] encoding) {
if (encoding.length < 2) {
// no enough data to extract msg len, just return -1
return -1;
}
if (encoding[0] != 0x30) {
throw new RuntimeException("Error: bad LDAP encoding message: "
+ "expected ASN.1 SEQUENCE tag (0x30), encountered "
+ encoding[0]);
}
int len;
int index = 1;
int payloadLen = 0;
if ((encoding[1] & 0x80) == 0x80) {
len = (encoding[1] & 0x0F);
index++;
} else {
len = 1;
}
if (len > 4) {
throw new RuntimeException(
"Error: LDAP encoding message payload too large");
}
if (encoding.length < index + len) {
// additional data required to extract payload len, return -1
return -1;
}
for (byte b : Arrays.copyOfRange(encoding, index, index + len)) {
payloadLen = payloadLen << 8 | (b & 0xFF);
}
if (payloadLen <= 0) {
throw new RuntimeException(
"Error: invalid LDAP encoding message length or payload too large");
}
return index + len + payloadLen;
}
}
}