/* * Copyright 2011 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 static io.netty.handler.codec.http.HttpHeaders.Values.*; import static io.netty.handler.codec.http.HttpVersion.*; import io.netty.channel.Channel; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelPipeline; import io.netty.handler.codec.http.DefaultHttpResponse; import io.netty.handler.codec.http.HttpChunkAggregator; import io.netty.handler.codec.http.HttpHeaders.Names; import io.netty.handler.codec.http.HttpRequest; import io.netty.handler.codec.http.HttpRequestDecoder; import io.netty.handler.codec.http.HttpResponse; import io.netty.handler.codec.http.HttpResponseEncoder; import io.netty.handler.codec.http.HttpResponseStatus; import io.netty.logging.InternalLogger; import io.netty.logging.InternalLoggerFactory; import io.netty.util.CharsetUtil; /** *
* Performs server side opening and closing handshakes for RFC 6455 * (originally web socket specification version draft-ietf-hybi-thewebsocketprotocol- * 17). *
*/ public class WebSocketServerHandshaker13 extends WebSocketServerHandshaker { private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocketServerHandshaker13.class); 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; } /** ** Handle the web socket handshake for the web socket specification HyBi versions 13-17. Versions 13-17 * share the same wire protocol. *
* ** Browser request to the server: *
* ** 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 ** *
* Server response: *
* ** HTTP/1.1 101 Switching Protocols * Upgrade: websocket * Connection: Upgrade * Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo= * Sec-WebSocket-Protocol: chat ** * @param channel * Channel * @param req * HTTP request */ @Override public ChannelFuture handshake(Channel channel, HttpRequest req) { if (logger.isDebugEnabled()) { logger.debug(String.format("Channel %s WS Version 13 server handshake", channel.id())); } HttpResponse res = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.SWITCHING_PROTOCOLS); String key = req.getHeader(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(String.format("WS Version 13 Server Handshake key: %s. Response: %s.", key, accept)); } res.setStatus(HttpResponseStatus.SWITCHING_PROTOCOLS); res.addHeader(Names.UPGRADE, WEBSOCKET.toLowerCase()); res.addHeader(Names.CONNECTION, Names.UPGRADE); res.addHeader(Names.SEC_WEBSOCKET_ACCEPT, accept); String subprotocols = req.getHeader(Names.SEC_WEBSOCKET_PROTOCOL); if (subprotocols != null) { String selectedSubprotocol = selectSubprotocol(subprotocols); if (selectedSubprotocol == null) { throw new WebSocketHandshakeException("Requested subprotocol(s) not supported: " + subprotocols); } else { res.addHeader(Names.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol); setSelectedSubprotocol(selectedSubprotocol); } } ChannelFuture future = channel.write(res); // Upgrade the connection and send the handshake response. ChannelPipeline p = channel.pipeline(); if (p.get(HttpChunkAggregator.class) != null) { p.remove(HttpChunkAggregator.class); } p.replace(HttpRequestDecoder.class, "wsdecoder", new WebSocket13FrameDecoder(true, allowExtensions, getMaxFramePayloadLength())); p.replace(HttpResponseEncoder.class, "wsencoder", new WebSocket13FrameEncoder(false)); return future; } /** * Echo back the closing frame and close the connection * * @param channel * Channel * @param frame * Web Socket frame that was received */ @Override public ChannelFuture close(Channel channel, CloseWebSocketFrame frame) { ChannelFuture f = channel.write(frame); f.addListener(ChannelFutureListener.CLOSE); return f; } }