/*
* Copyright (c) 2016, 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.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.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
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.CompletableFuture;
import java.util.function.Function;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
//
// Performs a simple opening handshake and yields the channel.
//
// 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
//
//
// Server Response:
//
// HTTP/1.1 101 Switching Protocols
// Upgrade: websocket
// Connection: Upgrade
// Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
// Sec-WebSocket-Protocol: chat
//
final class HandshakePhase {
private final ServerSocketChannel ssc;
HandshakePhase(InetSocketAddress address) {
requireNonNull(address);
try {
ssc = ServerSocketChannel.open();
ssc.bind(address);
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
//
// Returned CF completes normally after the handshake has been performed
//
CompletableFuture<SocketChannel> afterHandshake(
Function<List<String>, List<String>> mapping) {
return CompletableFuture.supplyAsync(
() -> {
SocketChannel socketChannel = accept();
try {
StringBuilder request = new StringBuilder();
if (!readRequest(socketChannel, request)) {
throw new IllegalStateException();
}
List<String> strings = Arrays.asList(
request.toString().split("\r\n")
);
List<String> response = mapping.apply(strings);
writeResponse(socketChannel, response);
return socketChannel;
} catch (Throwable t) {
try {
socketChannel.close();
} catch (IOException ignored) { }
throw t;
}
});
}
CompletableFuture<SocketChannel> afterHandshake() {
return afterHandshake((request) -> {
List<String> response = new LinkedList<>();
Iterator<String> iterator = request.iterator();
if (!iterator.hasNext()) {
throw new IllegalStateException("The request is empty");
}
if (!"GET / HTTP/1.1".equals(iterator.next())) {
throw new IllegalStateException
("Unexpected status line: " + request.get(0));
}
response.add("HTTP/1.1 101 Switching Protocols");
Map<String, 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));
}
if (requestHeaders.put(split[0], split[1]) != null) {
throw new IllegalStateException
("Duplicating headers: " + Arrays.toString(split));
}
}
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");
String key = requestHeaders.get("Sec-WebSocket-Key");
if (key == null) {
throw new IllegalStateException("Sec-WebSocket-Key is missing");
}
MessageDigest sha1 = null;
try {
sha1 = MessageDigest.getInstance("SHA-1");
} catch (NoSuchAlgorithmException e) {
throw new InternalError(e);
}
String x = key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
sha1.update(x.getBytes(StandardCharsets.ISO_8859_1));
String v = Base64.getEncoder().encodeToString(sha1.digest());
response.add("Sec-WebSocket-Accept: " + v);
return response;
});
}
private String expectHeader(Map<String, String> headers,
String name,
String value) {
String v = headers.get(name);
if (!value.equals(v)) {
throw new IllegalStateException(
format("Expected '%s: %s', actual: '%s: %s'",
name, value, name, v)
);
}
return v;
}
URI getURI() {
InetSocketAddress a;
try {
a = (InetSocketAddress) ssc.getLocalAddress();
} catch (IOException e) {
throw new UncheckedIOException(e);
}
return URI.create("ws://" + a.getHostName() + ":" + a.getPort());
}
private int read(SocketChannel socketChannel, ByteBuffer buffer) {
try {
int num = socketChannel.read(buffer);
if (num == -1) {
throw new IllegalStateException("Unexpected EOF");
}
assert socketChannel.isBlocking() && num > 0;
return num;
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
private SocketChannel accept() {
SocketChannel socketChannel = null;
try {
socketChannel = ssc.accept();
socketChannel.configureBlocking(true);
} catch (IOException e) {
if (socketChannel != null) {
try {
socketChannel.close();
} catch (IOException ignored) { }
}
throw new UncheckedIOException(e);
}
return socketChannel;
}
private boolean readRequest(SocketChannel socketChannel,
StringBuilder request) {
ByteBuffer buffer = ByteBuffer.allocateDirect(512);
read(socketChannel, buffer);
CharBuffer decoded;
buffer.flip();
try {
decoded =
StandardCharsets.ISO_8859_1.newDecoder().decode(buffer);
} catch (CharacterCodingException e) {
throw new UncheckedIOException(e);
}
request.append(decoded);
return Pattern.compile("\r\n\r\n").matcher(request).find();
}
private void writeResponse(SocketChannel socketChannel,
List<String> response) {
String s = response.stream().collect(Collectors.joining("\r\n"))
+ "\r\n\r\n";
ByteBuffer encoded;
try {
encoded =
StandardCharsets.ISO_8859_1.newEncoder().encode(CharBuffer.wrap(s));
} catch (CharacterCodingException e) {
throw new UncheckedIOException(e);
}
write(socketChannel, encoded);
}
private void write(SocketChannel socketChannel, ByteBuffer buffer) {
try {
while (buffer.hasRemaining()) {
socketChannel.write(buffer);
}
} catch (IOException e) {
try {
socketChannel.close();
} catch (IOException ignored) { }
throw new UncheckedIOException(e);
}
}
}