/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you 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.netty.handler.codec.http.websocketx;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpHeaders.Names;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.util.CharsetUtil;
import static io.netty.handler.codec.http.HttpHeaders.Values.*;
import static io.netty.handler.codec.http.HttpVersion.*;
/**
* <p>
* Performs server side opening and closing handshakes for <a href="http://netty.io/s/rfc6455">RFC 6455</a>
* (originally web socket specification <a href="http://netty.io/s/ws-17">draft-ietf-hybi-thewebsocketprotocol-17</a>).
* </p>
*/
public class WebSocketServerHandshaker13 extends WebSocketServerHandshaker {
public static final String WEBSOCKET_13_ACCEPT_GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
private final boolean allowExtensions;
/**
* Constructor specifying the destination web socket location
*
* @param webSocketURL
* URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web
* socket frames will be sent to this URL.
* @param subprotocols
* CSV of supported protocols
* @param allowExtensions
* Allow extensions to be used in the reserved bits of the web socket frame
* @param maxFramePayloadLength
* Maximum allowable frame payload length. Setting this value to your application's
* requirement may reduce denial of service attacks using long data frames.
*/
public WebSocketServerHandshaker13(
String webSocketURL, String subprotocols, boolean allowExtensions, int maxFramePayloadLength) {
super(WebSocketVersion.V13, webSocketURL, subprotocols, maxFramePayloadLength);
this.allowExtensions = allowExtensions;
}
/**
* <p>
* Handle the web socket handshake for the web socket specification <a href=
* "http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17">HyBi versions 13-17</a>. Versions 13-17
* share the same wire protocol.
* </p>
*
* <p>
* Browser request to the server:
* </p>
*
* <pre>
* GET /chat HTTP/1.1
* Host: server.example.com
* Upgrade: websocket
* Connection: Upgrade
* Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
* Sec-WebSocket-Origin: http://example.com
* Sec-WebSocket-Protocol: chat, superchat
* Sec-WebSocket-Version: 13
* </pre>
*
* <p>
* Server response:
* </p>
*
* <pre>
* HTTP/1.1 101 Switching Protocols
* Upgrade: websocket
* Connection: Upgrade
* Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
* Sec-WebSocket-Protocol: chat
* </pre>
*/
@Override
protected FullHttpResponse newHandshakeResponse(FullHttpRequest req, HttpHeaders headers) {
FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, HttpResponseStatus.SWITCHING_PROTOCOLS);
if (headers != null) {
res.headers().add(headers);
}
String key = req.headers().get(Names.SEC_WEBSOCKET_KEY);
if (key == null) {
throw new WebSocketHandshakeException("not a WebSocket request: missing key");
}
String acceptSeed = key + WEBSOCKET_13_ACCEPT_GUID;
byte[] sha1 = WebSocketUtil.sha1(acceptSeed.getBytes(CharsetUtil.US_ASCII));
String accept = WebSocketUtil.base64(sha1);
if (logger.isDebugEnabled()) {
logger.debug("WebSocket version 13 server handshake key: {}, response: {}", key, accept);
}
res.headers().add(Names.UPGRADE, WEBSOCKET.toLowerCase());
res.headers().add(Names.CONNECTION, Names.UPGRADE);
res.headers().add(Names.SEC_WEBSOCKET_ACCEPT, accept);
String subprotocols = req.headers().get(Names.SEC_WEBSOCKET_PROTOCOL);
if (subprotocols != null) {
String selectedSubprotocol = selectSubprotocol(subprotocols);
if (selectedSubprotocol == null) {
if (logger.isDebugEnabled()) {
logger.debug("Requested subprotocol(s) not supported: {}", subprotocols);
}
} else {
res.headers().add(Names.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
}
}
return res;
}
@Override
protected WebSocketFrameDecoder newWebsocketDecoder() {
return new WebSocket13FrameDecoder(true, allowExtensions, maxFramePayloadLength());
}
@Override
protected WebSocketFrameEncoder newWebSocketEncoder() {
return new WebSocket13FrameEncoder(false);
}
}