/**
* Copyright 2012 Nikita Koksharov
*
* 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.
*/
package com.corundumstudio.socketio.handler;
import static io.netty.handler.codec.http.HttpHeaders.Names.ACCESS_CONTROL_ALLOW_CREDENTIALS;
import static io.netty.handler.codec.http.HttpHeaders.Names.ACCESS_CONTROL_ALLOW_HEADERS;
import static io.netty.handler.codec.http.HttpHeaders.Names.ACCESS_CONTROL_ALLOW_ORIGIN;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
import static io.netty.handler.codec.http.HttpHeaders.Values.KEEP_ALIVE;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
import io.netty.buffer.ByteBuf;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelOutboundHandlerAdapter;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.DefaultHttpResponse;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.LastHttpContent;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.util.Attribute;
import io.netty.util.AttributeKey;
import io.netty.util.CharsetUtil;
import java.io.IOException;
import java.net.URL;
import java.util.Enumeration;
import java.util.Queue;
import java.util.jar.Attributes;
import java.util.jar.Manifest;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.corundumstudio.socketio.Transport;
import com.corundumstudio.socketio.messages.BaseMessage;
import com.corundumstudio.socketio.messages.HttpMessage;
import com.corundumstudio.socketio.messages.OutPacketMessage;
import com.corundumstudio.socketio.messages.XHROptionsMessage;
import com.corundumstudio.socketio.messages.XHRPostMessage;
import com.corundumstudio.socketio.protocol.PacketEncoder;
import com.corundumstudio.socketio.protocol.Packet;
@Sharable
public class EncoderHandler extends ChannelOutboundHandlerAdapter {
private static final byte[] OK = "ok".getBytes(CharsetUtil.UTF_8);
public static final AttributeKey<String> ORIGIN = AttributeKey.valueOf("origin");
public static final AttributeKey<String> USER_AGENT = AttributeKey.valueOf("userAgent");
public static final AttributeKey<Integer> JSONP_INDEX = AttributeKey.valueOf("jsonpIndex");
public static final AttributeKey<Boolean> WRITE_ONCE = AttributeKey.valueOf("writeOnce");
private final Logger log = LoggerFactory.getLogger(getClass());
private final PacketEncoder encoder;
private String version;
public EncoderHandler(boolean addVersionHeader, PacketEncoder encoder) throws IOException {
this.encoder = encoder;
if (addVersionHeader) {
readVersion();
}
}
private void readVersion() throws IOException {
Enumeration<URL> resources = getClass().getClassLoader().getResources("META-INF/MANIFEST.MF");
while (resources.hasMoreElements()) {
try {
Manifest manifest = new Manifest(resources.nextElement().openStream());
Attributes attrs = manifest.getMainAttributes();
if (attrs == null) {
continue;
}
String name = attrs.getValue("Bundle-Name");
if (name != null && name.equals("netty-socketio")) {
version = name + "/" + attrs.getValue("Bundle-Version");
break;
}
} catch (IOException E) {
// skip it
}
}
}
private void write(XHROptionsMessage msg, Channel channel, ByteBuf out) {
HttpResponse res = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.OK);
HttpHeaders.addHeader(res, "Set-Cookie", "io=" + msg.getSessionId());
HttpHeaders.addHeader(res, CONNECTION, KEEP_ALIVE);
HttpHeaders.addHeader(res, ACCESS_CONTROL_ALLOW_HEADERS, CONTENT_TYPE);
addOriginHeaders(channel, res);
sendMessage(msg, channel, out, res);
}
private void write(XHRPostMessage msg, Channel channel, ByteBuf out) {
out.writeBytes(OK);
sendMessage(msg, channel, out, "text/html");
}
private void sendMessage(HttpMessage msg, Channel channel, ByteBuf out, String type) {
HttpResponse res = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.OK);
res.headers().add(CONTENT_TYPE, type).add("Set-Cookie", "io=" + msg.getSessionId())
.add(CONNECTION, KEEP_ALIVE);
addOriginHeaders(channel, res);
HttpHeaders.setContentLength(res, out.readableBytes());
// prevent XSS warnings on IE
// https://github.com/LearnBoost/socket.io/pull/1333
String userAgent = channel.attr(EncoderHandler.USER_AGENT).get();
if (userAgent != null && (userAgent.contains(";MSIE") || userAgent.contains("Trident/"))) {
res.headers().add("X-XSS-Protection", "0");
}
sendMessage(msg, channel, out, res);
}
private void sendMessage(HttpMessage msg, Channel channel, ByteBuf out, HttpResponse res) {
channel.write(res);
if (log.isTraceEnabled()) {
log.trace("Out message: {} - sessionId: {}", out.toString(CharsetUtil.UTF_8), msg.getSessionId());
}
if (out.isReadable()) {
channel.write(out);
} else {
out.release();
}
channel.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT).addListener(ChannelFutureListener.CLOSE);
}
private void addOriginHeaders(Channel channel, HttpResponse res) {
if (version != null) {
res.headers().add(HttpHeaders.Names.SERVER, version);
}
String origin = channel.attr(ORIGIN).get();
if (origin != null) {
HttpHeaders.addHeader(res, ACCESS_CONTROL_ALLOW_ORIGIN, origin);
HttpHeaders.addHeader(res, ACCESS_CONTROL_ALLOW_CREDENTIALS, Boolean.TRUE);
} else {
HttpHeaders.addHeader(res, ACCESS_CONTROL_ALLOW_ORIGIN, "*");
}
}
@Override
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
if (!(msg instanceof BaseMessage)) {
super.write(ctx, msg, promise);
return;
}
ByteBuf out = encoder.allocateBuffer(ctx.alloc());
if (msg instanceof OutPacketMessage) {
OutPacketMessage m = (OutPacketMessage) msg;
if (m.getTransport() == Transport.WEBSOCKET) {
handleWebsocket((OutPacketMessage) msg, ctx);
}
if (m.getTransport() == Transport.POLLING) {
handleHTTP((OutPacketMessage) msg, ctx, out);
}
}
if (msg instanceof XHROptionsMessage) {
write((XHROptionsMessage) msg, ctx.channel(), out);
}
if (msg instanceof XHRPostMessage) {
write((XHRPostMessage) msg, ctx.channel(), out);
}
}
private void handleWebsocket(OutPacketMessage msg, ChannelHandlerContext ctx) throws IOException {
while (true) {
Queue<Packet> queue = msg.getClientHead().getPacketsQueue(msg.getTransport());
Packet packet = queue.poll();
if (packet == null) {
break;
}
ByteBuf out = encoder.allocateBuffer(ctx.alloc());
encoder.encodePacket(packet, out, ctx.alloc(), true, false);
WebSocketFrame res = new TextWebSocketFrame(out);
if (log.isTraceEnabled()) {
log.trace("Out message: {} sessionId: {}", out.toString(CharsetUtil.UTF_8),
msg.getSessionId());
}
ctx.channel().writeAndFlush(res);
if (!out.isReadable()) {
out.release();
}
}
}
private void handleHTTP(OutPacketMessage msg, ChannelHandlerContext ctx, ByteBuf out) throws IOException {
Channel channel = ctx.channel();
Attribute<Boolean> attr = channel.attr(WRITE_ONCE);
Queue<Packet> queue = msg.getClientHead().getPacketsQueue(msg.getTransport());
if (!channel.isActive() || queue.isEmpty() || !attr.compareAndSet(null, true)) {
out.release();
return;
}
Integer jsonpIndex = ctx.channel().attr(EncoderHandler.JSONP_INDEX).get();
if (jsonpIndex != null) {
encoder.encodeJsonP(jsonpIndex, queue, out, ctx.alloc(), 50);
sendMessage(msg, channel, out, "application/javascript");
} else {
encoder.encodePackets(queue, out, ctx.alloc(), 50);
sendMessage(msg, channel, out, "application/octet-stream");
}
}
}