/*
* 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.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpContentCompressor;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpRequestDecoder;
import io.netty.handler.codec.http.HttpResponseEncoder;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.internal.EmptyArrays;
import io.netty.util.internal.StringUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.nio.channels.ClosedChannelException;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;
/**
* Base class for server side web socket opening and closing handshakes
*/
public abstract class WebSocketServerHandshaker {
protected static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocketServerHandshaker.class);
private static final ClosedChannelException CLOSED_CHANNEL_EXCEPTION = new ClosedChannelException();
static {
CLOSED_CHANNEL_EXCEPTION.setStackTrace(EmptyArrays.EMPTY_STACK_TRACE);
}
private final String uri;
private final String[] subprotocols;
private final WebSocketVersion version;
private final int maxFramePayloadLength;
private String selectedSubprotocol;
/**
* Use this as wildcard to support all requested sub-protocols
*/
public static final String SUB_PROTOCOL_WILDCARD = "*";
/**
* Constructor specifying the destination web socket location
*
* @param version
* the protocol version
* @param uri
* 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 maxFramePayloadLength
* Maximum length of a frame's payload
*/
protected WebSocketServerHandshaker(
WebSocketVersion version, String uri, String subprotocols,
int maxFramePayloadLength) {
this.version = version;
this.uri = uri;
if (subprotocols != null) {
String[] subprotocolArray = StringUtil.split(subprotocols, ',');
for (int i = 0; i < subprotocolArray.length; i++) {
subprotocolArray[i] = subprotocolArray[i].trim();
}
this.subprotocols = subprotocolArray;
} else {
this.subprotocols = EmptyArrays.EMPTY_STRINGS;
}
this.maxFramePayloadLength = maxFramePayloadLength;
}
/**
* Returns the URL of the web socket
*/
public String uri() {
return uri;
}
/**
* Returns the CSV of supported sub protocols
*/
public Set<String> subprotocols() {
Set<String> ret = new LinkedHashSet<String>();
Collections.addAll(ret, subprotocols);
return ret;
}
/**
* Returns the version of the specification being supported
*/
public WebSocketVersion version() {
return version;
}
/**
* Gets the maximum length for any frame's payload.
*
* @return The maximum length for a frame's payload
*/
public int maxFramePayloadLength() {
return maxFramePayloadLength;
}
/**
* Performs the opening handshake. When call this method you <strong>MUST NOT</strong> retain the
* {@link FullHttpRequest} which is passed in.
*
* @param channel
* Channel
* @param req
* HTTP Request
* @return future
* The {@link ChannelFuture} which is notified once the opening handshake completes
*/
public ChannelFuture handshake(Channel channel, FullHttpRequest req) {
return handshake(channel, req, null, channel.newPromise());
}
/**
* Performs the opening handshake
*
* When call this method you <strong>MUST NOT</strong> retain the {@link FullHttpRequest} which is passed in.
*
* @param channel
* Channel
* @param req
* HTTP Request
* @param responseHeaders
* Extra headers to add to the handshake response or {@code null} if no extra headers should be added
* @param promise
* the {@link ChannelPromise} to be notified when the opening handshake is done
* @return future
* the {@link ChannelFuture} which is notified when the opening handshake is done
*/
public final ChannelFuture handshake(Channel channel, FullHttpRequest req,
HttpHeaders responseHeaders, final ChannelPromise promise) {
if (logger.isDebugEnabled()) {
logger.debug("{} WebSocket version {} server handshake", channel, version());
}
FullHttpResponse response = newHandshakeResponse(req, responseHeaders);
ChannelPipeline p = channel.pipeline();
if (p.get(HttpObjectAggregator.class) != null) {
p.remove(HttpObjectAggregator.class);
}
if (p.get(HttpContentCompressor.class) != null) {
p.remove(HttpContentCompressor.class);
}
ChannelHandlerContext ctx = p.context(HttpRequestDecoder.class);
final String encoderName;
if (ctx == null) {
// this means the user use a HttpServerCodec
ctx = p.context(HttpServerCodec.class);
if (ctx == null) {
promise.setFailure(
new IllegalStateException("No HttpDecoder and no HttpServerCodec in the pipeline"));
return promise;
}
p.addBefore(ctx.name(), "wsdecoder", newWebsocketDecoder());
p.addBefore(ctx.name(), "wsencoder", newWebSocketEncoder());
encoderName = ctx.name();
} else {
p.replace(ctx.name(), "wsdecoder", newWebsocketDecoder());
encoderName = p.context(HttpResponseEncoder.class).name();
p.addBefore(encoderName, "wsencoder", newWebSocketEncoder());
}
channel.writeAndFlush(response).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
ChannelPipeline p = future.channel().pipeline();
p.remove(encoderName);
promise.setSuccess();
} else {
promise.setFailure(future.cause());
}
}
});
return promise;
}
/**
* Performs the opening handshake. When call this method you <strong>MUST NOT</strong> retain the
* {@link FullHttpRequest} which is passed in.
*
* @param channel
* Channel
* @param req
* HTTP Request
* @return future
* The {@link ChannelFuture} which is notified once the opening handshake completes
*/
public ChannelFuture handshake(Channel channel, HttpRequest req) {
return handshake(channel, req, null, channel.newPromise());
}
/**
* Performs the opening handshake
*
* When call this method you <strong>MUST NOT</strong> retain the {@link HttpRequest} which is passed in.
*
* @param channel
* Channel
* @param req
* HTTP Request
* @param responseHeaders
* Extra headers to add to the handshake response or {@code null} if no extra headers should be added
* @param promise
* the {@link ChannelPromise} to be notified when the opening handshake is done
* @return future
* the {@link ChannelFuture} which is notified when the opening handshake is done
*/
public final ChannelFuture handshake(final Channel channel, HttpRequest req,
final HttpHeaders responseHeaders, final ChannelPromise promise) {
if (req instanceof FullHttpRequest) {
return handshake(channel, (FullHttpRequest) req, responseHeaders, promise);
}
if (logger.isDebugEnabled()) {
logger.debug("{} WebSocket version {} server handshake", channel, version());
}
ChannelPipeline p = channel.pipeline();
ChannelHandlerContext ctx = p.context(HttpRequestDecoder.class);
if (ctx == null) {
// this means the user use a HttpServerCodec
ctx = p.context(HttpServerCodec.class);
if (ctx == null) {
promise.setFailure(
new IllegalStateException("No HttpDecoder and no HttpServerCodec in the pipeline"));
return promise;
}
}
// Add aggregator and ensure we feed the HttpRequest so it is aggregated. A limit o 8192 should be more then
// enough for the websockets handshake payload.
//
// TODO: Make handshake work without HttpObjectAggregator at all.
String aggregatorName = "httpAggregator";
p.addAfter(ctx.name(), aggregatorName, new HttpObjectAggregator(8192));
p.addAfter(aggregatorName, "handshaker", new SimpleChannelInboundHandler<FullHttpRequest>() {
@Override
protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest msg) throws Exception {
// Remove ourself and do the actual handshake
ctx.pipeline().remove(this);
handshake(channel, msg, responseHeaders, promise);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
// Remove ourself and fail the handshake promise.
ctx.pipeline().remove(this);
promise.tryFailure(cause);
ctx.fireExceptionCaught(cause);
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
// Fail promise if Channel was closed
promise.tryFailure(CLOSED_CHANNEL_EXCEPTION);
ctx.fireChannelInactive();
}
});
try {
ctx.fireChannelRead(ReferenceCountUtil.retain(req));
} catch (Throwable cause) {
promise.setFailure(cause);
}
return promise;
}
/**
* Returns a new {@link FullHttpResponse) which will be used for as response to the handshake request.
*/
protected abstract FullHttpResponse newHandshakeResponse(FullHttpRequest req,
HttpHeaders responseHeaders);
/**
* 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).addListener(ChannelFutureListener.CLOSE);
}
/**
* Selects the first matching supported sub protocol
*
* @param requestedSubprotocols
* CSV of protocols to be supported. e.g. "chat, superchat"
* @return First matching supported sub protocol. Null if not found.
*/
protected String selectSubprotocol(String requestedSubprotocols) {
if (requestedSubprotocols == null || subprotocols.length == 0) {
return null;
}
String[] requestedSubprotocolArray = StringUtil.split(requestedSubprotocols, ',');
for (String p: requestedSubprotocolArray) {
String requestedSubprotocol = p.trim();
for (String supportedSubprotocol: subprotocols) {
if (SUB_PROTOCOL_WILDCARD.equals(supportedSubprotocol)
|| requestedSubprotocol.equals(supportedSubprotocol)) {
selectedSubprotocol = requestedSubprotocol;
return requestedSubprotocol;
}
}
}
// No match found
return null;
}
/**
* Returns the selected subprotocol. Null if no subprotocol has been selected.
* <p>
* This is only available AFTER <tt>handshake()</tt> has been called.
* </p>
*/
public String selectedSubprotocol() {
return selectedSubprotocol;
}
/**
* 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();
}