com.tc.websocket.server.handler.WebSocketValidationHandler.java Source code

Introduction

Here is the source code for com.tc.websocket.server.handler.WebSocketValidationHandler.java

Source

/*
 * Original Work: Copyright 2012 The Netty Project
 * 
 * Modified Work: Copyright 2016 Tek Counsel LLC
 *
 * Both 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 com.tc.websocket.server.handler;

import static io.netty.handler.codec.http.HttpMethod.GET;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;

import java.util.logging.Level;
import java.util.logging.Logger;

import com.google.inject.Inject;
import com.tc.websocket.Config;
import com.tc.websocket.Const;
import com.tc.websocket.IConfig;
import com.tc.websocket.server.IDominoWebSocketServer;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
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.HttpHeaderNames;
import io.netty.handler.codec.http.HttpUtil;
import io.netty.util.CharsetUtil;
import io.netty.util.ReferenceCountUtil;

// TODO: Auto-generated Javadoc
/**
 * The Class WebSocketValidationHandler.
 */
public class WebSocketValidationHandler extends SimpleChannelInboundHandler<FullHttpRequest> {

    /** The Constant LOG. */
    private static final Logger LOG = Logger.getLogger(WebSocketValidationHandler.class.getName());

    /** The server. */
    @Inject
    private IDominoWebSocketServer server;

    /** The cfg. */
    private IConfig cfg = Config.getInstance();

    /* (non-Javadoc)
     * @see io.netty.channel.SimpleChannelInboundHandler#channelRead0(io.netty.channel.ChannelHandlerContext, java.lang.Object)
     */
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest req) throws Exception {
        if (this.isValidRequest(ctx, req)) {
            ReferenceCountUtil.retain(req);
            ctx.fireChannelRead(req);
        }
    }

    /**
     * Checks if is valid request.
     *
     * @param ctx the ctx
     * @param req the req
     * @return true, if is valid request
     */
    public boolean isValidRequest(ChannelHandlerContext ctx, FullHttpRequest req) {
        // Handle a bad request.
        if (!req.decoderResult().isSuccess()) {
            sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST));
            return false;
        }

        // Allow only GET methods.
        if (req.method() != GET) {
            sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
            return false;
        }

        if ("/favicon.ico".equals(req.uri())) {
            FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, NOT_FOUND);
            sendHttpResponse(ctx, req, res);
            return false;
        }

        if (!req.uri().contains(Const.WEBSOCKET_URI)) {
            sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
            return false;
        }

        if (server.getWebSocketCount() >= cfg.getMaxConnections()) {
            LOG.log(Level.SEVERE, "Maximum number of websockets " + cfg.getMaxConnections() + " created.");
            sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
            return false;
        }

        String origin = req.headers().get(HttpHeaderNames.ORIGIN);
        if (origin != null && !Config.getInstance().isAllowedOrigin(origin)) {
            LOG.log(Level.SEVERE, "Invalid origin " + origin + " attempting to make websocket connection");
            sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
            return false;
        }

        return true;
    }

    /**
     * Send http response.
     *
     * @param ctx the ctx
     * @param req the req
     * @param res the res
     */
    private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) {
        // Generate an error page if response getStatus code is not OK (200).
        if (res.status().code() != 200) {
            ByteBuf buf = Unpooled.copiedBuffer(res.status().toString(), CharsetUtil.UTF_8);
            res.content().writeBytes(buf);
            buf.release();
            HttpUtil.setContentLength(res, res.content().readableBytes());
        }

        // Send the response and close the connection if necessary.
        ChannelFuture f = ctx.channel().writeAndFlush(res);
        if (!HttpUtil.isKeepAlive(req) || res.status().code() != 200) {
            f.addListener(ChannelFutureListener.CLOSE);
        }
    }

}