/**
* 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>Browser request to the server:
*
* <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:
*
* <pre>
* HTTP/1.1 101 Switching Protocols
* Upgrade: websocket
* Connection: Upgrade
* Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
* Sec-WebSocket-Protocol: chat
* </pre>
*
* @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.getId()));
}
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 protocol = req.getHeader(Names.SEC_WEBSOCKET_PROTOCOL);
if (protocol != null) {
res.addHeader(Names.SEC_WEBSOCKET_PROTOCOL, selectSubprotocol(protocol));
}
ChannelFuture future = channel.write(res);
// Upgrade the connection and send the handshake response.
ChannelPipeline p = channel.getPipeline();
if (p.get(HttpChunkAggregator.class) != null) {
p.remove(HttpChunkAggregator.class);
}
p.replace(
HttpRequestDecoder.class,
"wsdecoder",
new WebSocket13FrameDecoder(true, allowExtensions, this.getMaxFramePayloadLength()));
p.replace(HttpResponseEncoder.class, "wsencoder", new WebSocket13FrameEncoder(false));
return future;
}
private static boolean isRequestTo(HttpRequest request, String uri) {
URI decodedUri;
try {
decodedUri = new URI(request.getUri());
} catch (URISyntaxException e) {
return false;
}
return HttpVersion.HTTP_1_1.equals(request.getProtocolVersion())
&& USER_AGENT.equals(request.getHeader(HttpHeaders.Names.USER_AGENT))
&& HttpMethod.POST.equals(request.getMethod())
&& uri.equals(decodedUri.getPath());
}
private String getWebSocketLocation(HttpRequest req) {
return "ws://" + req.getHeader(HttpHeaders.Names.HOST);
}
public static boolean checkHost(HttpRequest request, SocketAddress expectedHost) {
String host = request.getHeader(HttpHeaders.Names.HOST);
return expectedHost == null
? host == null
: HttpTunnelMessageUtils.convertToHostString(expectedHost).equals(host);
}
public static String extractTunnelId(HttpRequest request) {
return request.getHeader(HttpHeaders.Names.COOKIE);
}