/**
* 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;
}
/**
* 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>
*/
@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);
}
CharSequence key = req.headers().get(HttpHeaderNames.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(HttpHeaderNames.UPGRADE, HttpHeaderValues.WEBSOCKET);
res.headers().add(HttpHeaderNames.CONNECTION, HttpHeaderValues.UPGRADE);
res.headers().add(HttpHeaderNames.SEC_WEBSOCKET_ACCEPT, accept);
String subprotocols = req.headers().getAsString(HttpHeaderNames.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(HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
}
}
return res;
}
