PcapWriteHandler.java — netty Source File

Source Code

/*
 * Copyright 2020 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:
 *
 * https://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.pcap;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.Channel;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelPromise;
import io.netty.channel.ServerChannel;
import io.netty.channel.socket.DatagramChannel;
import io.netty.channel.socket.DatagramPacket;
import io.netty.channel.socket.ServerSocketChannel;
import io.netty.channel.socket.SocketChannel;
import io.netty.util.NetUtil;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;

import java.io.Closeable;
import java.io.IOException;
import java.io.OutputStream;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.util.concurrent.atomic.AtomicReference;

import static io.netty.util.internal.ObjectUtil.checkNotNull;

/**
 * <p> {@link PcapWriteHandler} captures {@link ByteBuf} from {@link SocketChannel} / {@link ServerChannel}
 * or {@link DatagramPacket} and writes it into Pcap {@link OutputStream}. </p>
 *
 * <p>
 * Things to keep in mind when using {@link PcapWriteHandler} with TCP:
 *
 *    <ul>
 *        <li> Whenever {@link ChannelInboundHandlerAdapter#channelActive(ChannelHandlerContext)} is called,
 *        a fake TCP 3-way handshake (SYN, SYN+ACK, ACK) is simulated as new connection in Pcap. </li>
 *
 *        <li> Whenever {@link ChannelInboundHandlerAdapter#handlerRemoved(ChannelHandlerContext)} is called,
 *        a fake TCP 3-way handshake (FIN+ACK, FIN+ACK, ACK) is simulated as connection shutdown in Pcap.  </li>
 *
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