/*
* 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.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpClientCodec;
import io.netty.handler.codec.http.HttpContentDecompressor;
import io.netty.handler.codec.http.HttpHeaderNames;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpRequestEncoder;
import io.netty.handler.codec.http.HttpResponseDecoder;
import io.netty.util.internal.StringUtil;
import java.net.URI;
/**
* Base class for web socket client handshake implementations
*/
public abstract class WebSocketClientHandshaker {
private final URI uri;
private final WebSocketVersion version;
private volatile boolean handshakeComplete;
private final String expectedSubprotocol;
private volatile String actualSubprotocol;
protected final HttpHeaders customHeaders;
private final int maxFramePayloadLength;
/**
* Base constructor
*
* @param uri
* URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web socket frames will be
* sent to this URL.
* @param version
* Version of web socket specification to use to connect to the server
* @param subprotocol
* Sub protocol request sent to the server.
* @param customHeaders
* Map of custom headers to add to the client request
* @param maxFramePayloadLength
* Maximum length of a frame's payload
*/
protected WebSocketClientHandshaker(URI uri, WebSocketVersion version, String subprotocol,
HttpHeaders customHeaders, int maxFramePayloadLength) {
this.uri = uri;
this.version = version;
expectedSubprotocol = subprotocol;
this.customHeaders = customHeaders;
this.maxFramePayloadLength = maxFramePayloadLength;
}
/**
* Returns the URI to the web socket. e.g. "ws://myhost.com/path"
*/
public URI uri() {
return uri;
}
/**
* Version of the web socket specification that is being used
*/
public WebSocketVersion version() {
return version;
}
/**
* Returns the max length for any frame's payload
*/
public int maxFramePayloadLength() {
return maxFramePayloadLength;
}
/**
* Flag to indicate if the opening handshake is complete
*/
public boolean isHandshakeComplete() {
return handshakeComplete;
}
private void setHandshakeComplete() {
handshakeComplete = true;
}
/**
* Returns the CSV of requested subprotocol(s) sent to the server as specified in the constructor
*/
public String expectedSubprotocol() {
return expectedSubprotocol;
}
/**
* Returns the subprotocol response sent by the server. Only available after end of handshake.
* Null if no subprotocol was requested or confirmed by the server.
*/
public String actualSubprotocol() {
return actualSubprotocol;
}
private void setActualSubprotocol(String actualSubprotocol) {
this.actualSubprotocol = actualSubprotocol;
}
/**
* Begins the opening handshake
*
* @param channel
* Channel
*/
public ChannelFuture handshake(Channel channel) {
if (channel == null) {
throw new NullPointerException("channel");
}
return handshake(channel, channel.newPromise());
}
/**
* Begins the opening handshake
*
* @param channel
* Channel
* @param promise
* the {@link ChannelPromise} to be notified when the opening handshake is sent
*/
public final ChannelFuture handshake(Channel channel, final ChannelPromise promise) {
FullHttpRequest request = newHandshakeRequest();
HttpResponseDecoder decoder = channel.pipeline().get(HttpResponseDecoder.class);
if (decoder == null) {
HttpClientCodec codec = channel.pipeline().get(HttpClientCodec.class);
if (codec == null) {
promise.setFailure(new IllegalStateException("ChannelPipeline does not contain " +
"a HttpResponseDecoder or HttpClientCodec"));
return promise;
}
}
channel.writeAndFlush(request).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) {
if (future.isSuccess()) {
ChannelPipeline p = future.channel().pipeline();
ChannelHandlerContext ctx = p.context(HttpRequestEncoder.class);
if (ctx == null) {
ctx = p.context(HttpClientCodec.class);
}
if (ctx == null) {
promise.setFailure(new IllegalStateException("ChannelPipeline does not contain " +
"a HttpRequestEncoder or HttpClientCodec"));
return;
}
p.addAfter(ctx.name(), "ws-encoder", newWebSocketEncoder());
promise.setSuccess();
} else {
promise.setFailure(future.cause());
}
}
});
return promise;
}
/**
* Returns a new {@link FullHttpRequest) which will be used for the handshake.
*/
protected abstract FullHttpRequest newHandshakeRequest();
/**
* Validates and finishes the opening handshake initiated by {@link #handshake}}.
*
* @param channel
* Channel
* @param response
* HTTP response containing the closing handshake details
*/
public final void finishHandshake(Channel channel, FullHttpResponse response) {
verify(response);
// Verify the subprotocol that we received from the server.
// This must be one of our expected subprotocols - or null/empty if we didn't want to speak a subprotocol
String receivedProtocol = response.headers().getAndConvert(HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL);
receivedProtocol = receivedProtocol != null ? receivedProtocol.trim() : null;
String expectedProtocol = expectedSubprotocol != null ? expectedSubprotocol : "";
boolean protocolValid = false;
if (expectedProtocol.isEmpty() && receivedProtocol == null) {
// No subprotocol required and none received
protocolValid = true;
setActualSubprotocol(expectedSubprotocol); // null or "" - we echo what the user requested
} else if (!expectedProtocol.isEmpty() && receivedProtocol != null && !receivedProtocol.isEmpty()) {
// We require a subprotocol and received one -> verify it
for (String protocol : StringUtil.split(expectedSubprotocol, ',')) {
if (protocol.trim().equals(receivedProtocol)) {
protocolValid = true;
setActualSubprotocol(receivedProtocol);
break;
}
}
} // else mixed cases - which are all errors
if (!protocolValid) {
throw new WebSocketHandshakeException(String.format(
"Invalid subprotocol. Actual: %s. Expected one of: %s",
receivedProtocol, expectedSubprotocol));
}
setHandshakeComplete();
ChannelPipeline p = channel.pipeline();
// Remove decompressor from pipeline if its in use
HttpContentDecompressor decompressor = p.get(HttpContentDecompressor.class);
if (decompressor != null) {
p.remove(decompressor);
}
ChannelHandlerContext ctx = p.context(HttpResponseDecoder.class);
if (ctx == null) {
ctx = p.context(HttpClientCodec.class);
if (ctx == null) {
throw new IllegalStateException("ChannelPipeline does not contain " +
"a HttpRequestEncoder or HttpClientCodec");
}
p.replace(ctx.name(), "ws-decoder", newWebsocketDecoder());
} else {
if (p.get(HttpRequestEncoder.class) != null) {
p.remove(HttpRequestEncoder.class);
}
p.replace(ctx.name(),
"ws-decoder", newWebsocketDecoder());
}
}
/**
* Verfiy the {@link FullHttpResponse} and throws a {@link WebSocketHandshakeException} if something is wrong.
*/
protected abstract void verify(FullHttpResponse response);
/**
* Returns the decoder to use after handshake is complete.
*/
protected abstract WebSocketFrameDecoder newWebsocketDecoder();
/**
* Returns the encoder to use after the handshake is complete.
*/
protected abstract WebSocketFrameEncoder newWebSocketEncoder();
/**
* Performs the closing handshake
*
* @param channel
* Channel
* @param frame
* Closing Frame that was received
*/
public ChannelFuture close(Channel channel, CloseWebSocketFrame frame) {
if (channel == null) {
throw new NullPointerException("channel");
}
return close(channel, frame, channel.newPromise());
}
/**
* Performs the closing handshake
*
* @param channel
* Channel
* @param frame
* Closing Frame that was received
* @param promise
* the {@link ChannelPromise} to be notified when the closing handshake is done
*/
public ChannelFuture close(Channel channel, CloseWebSocketFrame frame, ChannelPromise promise) {
if (channel == null) {
throw new NullPointerException("channel");
}
return channel.writeAndFlush(frame, promise);
}
}