/*
* Copyright (c) 2016, 2017, 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.Closeable;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.net.InetSocketAddress;
import java.net.URI;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.ClosedByInterruptException;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.CharacterCodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Base64;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.Function;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import static java.lang.String.format;
import static java.lang.System.err;
import static java.nio.charset.StandardCharsets.ISO_8859_1;
import static java.util.Arrays.asList;
import static java.util.Objects.requireNonNull;
/**
* Dummy WebSocket Server.
*
* Performs simpler version of the WebSocket Opening Handshake over HTTP (i.e.
* no proxying, cookies, etc.) Supports sequential connections, one at a time,
* i.e. in order for a client to connect to the server the previous client must
* disconnect first.
*
* Expected client request:
*
* GET /chat HTTP/1.1
* Host: server.example.com
* Upgrade: websocket
* Connection: Upgrade
* Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
* Origin: http://example.com
* Sec-WebSocket-Protocol: chat, superchat
* Sec-WebSocket-Version: 13
*
* This server response:
*
* HTTP/1.1 101 Switching Protocols
* Upgrade: websocket
* Connection: Upgrade
* Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
* Sec-WebSocket-Protocol: chat
*/
public final class DummyWebSocketServer implements Closeable {
private final AtomicBoolean started = new AtomicBoolean();
private final Thread thread;
private volatile ServerSocketChannel ssc;
private volatile InetSocketAddress address;
public DummyWebSocketServer() {
this(defaultMapping());
}
public DummyWebSocketServer(Function<List<String>, List<String>> mapping) {
requireNonNull(mapping);
thread = new Thread(() -> {
try {
while (!Thread.currentThread().isInterrupted()) {
err.println("Accepting next connection at: " + ssc);
SocketChannel channel = ssc.accept();
err.println("Accepted: " + channel);
try {
channel.configureBlocking(true);
StringBuilder request = new StringBuilder();
if (!readRequest(channel, request)) {
throw new IOException("Bad request:" + request);
}
List<String> strings = asList(request.toString().split("\r\n"));
List<String> response = mapping.apply(strings);
writeResponse(channel, response);
// Read until the thread is interrupted or an error occurred
// or the input is shutdown
ByteBuffer b = ByteBuffer.allocate(1024);
while (channel.read(b) != -1) {
b.clear();
}
} catch (IOException e) {
err.println("Error in connection: " + channel + ", " + e);
} finally {
err.println("Closed: " + channel);
close(channel);
}
}
} catch (ClosedByInterruptException ignored) {
} catch (IOException e) {
err.println(e);
} finally {
close(ssc);
err.println("Stopped at: " + getURI());
}
});
thread.setName("DummyWebSocketServer");
thread.setDaemon(false);
}
public void open() throws IOException {
err.println("Starting");
if (!started.compareAndSet(false, true)) {
throw new IllegalStateException("Already started");
}
ssc = ServerSocketChannel.open();
try {
ssc.configureBlocking(true);
ssc.bind(new InetSocketAddress("localhost", 0));
address = (InetSocketAddress) ssc.getLocalAddress();
thread.start();
} catch (IOException e) {
close(ssc);
}
err.println("Started at: " + getURI());
}
@Override
public void close() {
err.println("Stopping: " + getURI());
thread.interrupt();
close(ssc);
}
URI getURI() {
if (!started.get()) {
throw new IllegalStateException("Not yet started");
}
return URI.create("ws://" + address.getHostName() + ":" + address.getPort());
}
private boolean readRequest(SocketChannel channel, StringBuilder request)
throws IOException
{
ByteBuffer buffer = ByteBuffer.allocate(512);
while (channel.read(buffer) != -1) {
// read the complete HTTP request headers, there should be no body
CharBuffer decoded;
buffer.flip();
try {
decoded = ISO_8859_1.newDecoder().decode(buffer);
} catch (CharacterCodingException e) {
throw new UncheckedIOException(e);
}
request.append(decoded);
if (Pattern.compile("\r\n\r\n").matcher(request).find())
return true;
buffer.clear();
}
return false;
}
private void writeResponse(SocketChannel channel, List<String> response)
throws IOException
{
String s = response.stream().collect(Collectors.joining("\r\n"))
+ "\r\n\r\n";
ByteBuffer encoded;
try {
encoded = ISO_8859_1.newEncoder().encode(CharBuffer.wrap(s));
} catch (CharacterCodingException e) {
throw new UncheckedIOException(e);
}
while (encoded.hasRemaining()) {
channel.write(encoded);
}
}
private static Function<List<String>, List<String>> defaultMapping() {
return request -> {
List<String> response = new LinkedList<>();
Iterator<String> iterator = request.iterator();
if (!iterator.hasNext()) {
throw new IllegalStateException("The request is empty");
}
String statusLine = iterator.next();
if (!(statusLine.startsWith("GET /") && statusLine.endsWith(" HTTP/1.1"))) {
throw new IllegalStateException
("Unexpected status line: " + request.get(0));
}
response.add("HTTP/1.1 101 Switching Protocols");
Map<String, List<String>> requestHeaders = new HashMap<>();
while (iterator.hasNext()) {
String header = iterator.next();
String[] split = header.split(": ");
if (split.length != 2) {
throw new IllegalStateException
("Unexpected header: " + header
+ ", split=" + Arrays.toString(split));
}
requestHeaders.computeIfAbsent(split[0], k -> new ArrayList<>()).add(split[1]);
}
if (requestHeaders.containsKey("Sec-WebSocket-Protocol")) {
throw new IllegalStateException("Subprotocols are not expected");
}
if (requestHeaders.containsKey("Sec-WebSocket-Extensions")) {
throw new IllegalStateException("Extensions are not expected");
}
expectHeader(requestHeaders, "Connection", "Upgrade");
response.add("Connection: Upgrade");
expectHeader(requestHeaders, "Upgrade", "websocket");
response.add("Upgrade: websocket");
expectHeader(requestHeaders, "Sec-WebSocket-Version", "13");
List<String> key = requestHeaders.get("Sec-WebSocket-Key");
if (key == null || key.isEmpty()) {
throw new IllegalStateException("Sec-WebSocket-Key is missing");
}
if (key.size() != 1) {
throw new IllegalStateException("Sec-WebSocket-Key has too many values : " + key);
}
MessageDigest sha1 = null;
try {
sha1 = MessageDigest.getInstance("SHA-1");
} catch (NoSuchAlgorithmException e) {
throw new InternalError(e);
}
String x = key.get(0) + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
sha1.update(x.getBytes(ISO_8859_1));
String v = Base64.getEncoder().encodeToString(sha1.digest());
response.add("Sec-WebSocket-Accept: " + v);
return response;
};
}
protected static String expectHeader(Map<String, List<String>> headers,
String name,
String value) {
List<String> v = headers.get(name);
if (!v.contains(value)) {
throw new IllegalStateException(
format("Expected '%s: %s', actual: '%s: %s'",
name, value, name, v)
);
}
return value;
}
private static void close(AutoCloseable... acs) {
for (AutoCloseable ac : acs) {
try {
ac.close();
} catch (Exception ignored) { }
}
}
}