/*
* #%L
* ACS AEM Tools Bundle
* %%
* Copyright (C) 2013 Adobe
* %%
* Licensed 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.
* #L%
*/
package com.adobe.acs.livereload.impl;
import static com.adobe.acs.livereload.impl.LiveReloadConstants.*;
import static io.netty.handler.codec.http.HttpHeaders.*;
import static io.netty.handler.codec.http.HttpHeaders.Names.*;
import static io.netty.handler.codec.http.HttpMethod.*;
import static io.netty.handler.codec.http.HttpResponseStatus.*;
import static io.netty.handler.codec.http.HttpVersion.*;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.group.ChannelGroup;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PingWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PongWebSocketFrame;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
import io.netty.util.CharsetUtil;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Map;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.IOUtils;
import org.apache.sling.commons.json.JSONArray;
import org.apache.sling.commons.json.JSONException;
import org.apache.sling.commons.json.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* See http://feedback.livereload.com/knowledgebase/articles/86174-livereload-
* protocol.
*/
public final class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> {
private ChannelGroup group;
private Map<Channel, ChannelInfo> infos;
public WebSocketServerHandler(ChannelGroup group, Map<Channel, ChannelInfo> infos) {
this.group = group;
this.infos = infos;
}
private static final Logger log = LoggerFactory.getLogger(WebSocketServerHandler.class);
private static final String WEBSOCKET_PATH = "/websocket";
private WebSocketServerHandshaker handshaker;
@Override
public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof FullHttpRequest) {
handleHttpRequest(ctx, (FullHttpRequest) msg);
} else if (msg instanceof WebSocketFrame) {
handleWebSocketFrame(ctx, (WebSocketFrame) msg);
}
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
ctx.flush();
}
private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) throws Exception {
// Handle a bad request.
if (!req.getDecoderResult().isSuccess()) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST));
return;
}
// Allow only GET methods.
if (req.getMethod() != GET) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
return;
}
if ("/".equals(req.getUri()) || "/favicon.ico".equals(req.getUri())) {
FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, NOT_FOUND);
sendHttpResponse(ctx, req, res);
return;
}
if (req.getUri().startsWith("/livereload.js")) {
InputStream is = getClass().getResourceAsStream("/livereload.js");
byte[] data = IOUtils.toByteArray(is);
ByteBuf content = Unpooled.wrappedBuffer(data);
FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, OK, content);
res.headers().set(CONTENT_TYPE, "application/javascript");
setContentLength(res, content.readableBytes());
sendHttpResponse(ctx, req, res);
return;
}
// Handshake
WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
getWebSocketLocation(req), null, false);
handshaker = wsFactory.newHandshaker(req);
if (handshaker == null) {
WebSocketServerHandshakerFactory.sendUnsupportedWebSocketVersionResponse(ctx.channel());
} else {
handshaker.handshake(ctx.channel(), req);
}
}
private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
// Check for closing frame
if (frame instanceof CloseWebSocketFrame) {
handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain());
return;
}
if (frame instanceof PingWebSocketFrame) {
ctx.channel().write(new PongWebSocketFrame(frame.content().retain()));
return;
}
if (!(frame instanceof TextWebSocketFrame)) {
throw new UnsupportedOperationException(String.format("%s frame types not supported", frame.getClass()
.getName()));
}
String request = ((TextWebSocketFrame) frame).text();
try {
JSONObject obj = new JSONObject(request);
handleCommand(obj, ctx);
} catch (JSONException e) {
throw new IllegalArgumentException(String.format("%s is not a valid JSON object", request));
}
}
private void handleCommand(JSONObject obj, ChannelHandlerContext ctx) throws JSONException {
String cmd = obj.getString(COMMAND);
Channel channel = ctx.channel();
if (CMD_HELLO.equals(cmd)) {
JSONObject result = new JSONObject();
result.put(COMMAND, CMD_HELLO);
JSONArray protocols = new JSONArray();
protocols.put(PROTOCOL_VERSION_7);
result.put(PROTOCOLS, protocols);
result.put("serverName", "AEM Live Reload Server");
channel.write(new TextWebSocketFrame(result.toString()));
if (isSupported(obj)) {
log.info("adding LiveReload channel");
group.add(channel);
}
ChannelInfo info = new ChannelInfo(isSupported(obj));
infos.put(channel, info);
} else if (CMD_INFO.equals(cmd)) {
ChannelInfo info = infos.get(channel);
if (info != null) {
String url = obj.getString(URL);
try {
URI uri = new URI(url);
info.setUri(uri);
log.info("added uri to channel info {}", info);
} catch (URISyntaxException e) {
log.warn("Unable to store uri " + url, e);
}
}
} else {
log.warn("Unknown command {}", cmd);
log.info(obj.toString(2));
}
}
private boolean isSupported(JSONObject obj) {
try {
if (obj.has(PROTOCOLS)) {
JSONArray protocols = obj.getJSONArray(PROTOCOLS);
for (int i = 0; i < protocols.length(); i++) {
String protocol = protocols.getString(i);
if (PROTOCOL_VERSION_7.equals(protocol)) {
return true;
}
}
}
} catch (JSONException e) {
}
return false;
}
private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) {
// Generate an error page if response getStatus code is not OK (200).
if (res.getStatus().code() != HttpServletResponse.SC_OK) {
ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8);
res.content().writeBytes(buf);
buf.release();
setContentLength(res, res.content().readableBytes());
}
// Send the response and close the connection if necessary.
ChannelFuture f = ctx.channel().writeAndFlush(res);
if (!isKeepAlive(req) || res.getStatus().code() != HttpServletResponse.SC_OK) {
f.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
log.error("caught exception", cause);
ctx.close();
}
private static String getWebSocketLocation(FullHttpRequest req) {
return "ws://" + req.headers().get(HOST) + WEBSOCKET_PATH;
}
}