io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory Maven / Gradle / Ivy
/*
* 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.channel.Channel;
import io.netty.handler.codec.http.DefaultHttpResponse;
import io.netty.handler.codec.http.HttpHeaders.Names;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpVersion;
/**
* Auto-detects the version of the Web Socket protocol in use and creates a new proper
* {@link WebSocketServerHandshaker}.
*/
public class WebSocketServerHandshakerFactory {
private final String webSocketURL;
private final String subprotocols;
private final boolean allowExtensions;
private final int maxFramePayloadLength;
/**
* 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. Null if sub protocols not supported.
* @param allowExtensions
* Allow extensions to be used in the reserved bits of the web socket frame
*/
public WebSocketServerHandshakerFactory(
String webSocketURL, String subprotocols, boolean allowExtensions) {
this(webSocketURL, subprotocols, allowExtensions, 65536);
}
/**
* 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. Null if sub protocols not supported.
* @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 WebSocketServerHandshakerFactory(
String webSocketURL, String subprotocols, boolean allowExtensions,
int maxFramePayloadLength) {
this.webSocketURL = webSocketURL;
this.subprotocols = subprotocols;
this.allowExtensions = allowExtensions;
this.maxFramePayloadLength = maxFramePayloadLength;
}
/**
* Instances a new handshaker
*
* @return A new WebSocketServerHandshaker for the requested web socket version. Null if web
* socket version is not supported.
*/
public WebSocketServerHandshaker newHandshaker(HttpRequest req) {
String version = req.headers().get(Names.SEC_WEBSOCKET_VERSION);
if (version != null) {
if (version.equals(WebSocketVersion.V13.toHttpHeaderValue())) {
// Version 13 of the wire protocol - RFC 6455 (version 17 of the draft hybi specification).
return new WebSocketServerHandshaker13(
webSocketURL, subprotocols, allowExtensions, maxFramePayloadLength);
} else if (version.equals(WebSocketVersion.V08.toHttpHeaderValue())) {
// Version 8 of the wire protocol - version 10 of the draft hybi specification.
return new WebSocketServerHandshaker08(
webSocketURL, subprotocols, allowExtensions, maxFramePayloadLength);
} else if (version.equals(WebSocketVersion.V07.toHttpHeaderValue())) {
// Version 8 of the wire protocol - version 07 of the draft hybi specification.
return new WebSocketServerHandshaker07(
webSocketURL, subprotocols, allowExtensions, maxFramePayloadLength);
} else {
return null;
}
} else {
// Assume version 00 where version header was not specified
return new WebSocketServerHandshaker00(webSocketURL, subprotocols, maxFramePayloadLength);
}
}
/**
* Return that we need cannot not support the web socket version
*
* @param channel
* Channel
*/
public static void sendUnsupportedWebSocketVersionResponse(Channel channel) {
HttpResponse res = new DefaultHttpResponse(
HttpVersion.HTTP_1_1,
HttpResponseStatus.UPGRADE_REQUIRED);
res.headers().set(Names.SEC_WEBSOCKET_VERSION, WebSocketVersion.V13.toHttpHeaderValue());
channel.write(res);
}
}