io.netty.handler.pcap.IPPacket Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of wildfly-client-all

This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

There is a newer version: 34.0.0.Final

Show newest version

/*
 * 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;

final class IPPacket {

    private static final byte MAX_TTL = (byte) 255;
    private static final short V4_HEADER_SIZE = 20;
    private static final byte TCP = 6 & 0xff;
    private static final byte UDP = 17 & 0xff;

    /**
     * Version + Traffic class + Flow label
     */
    private static final int IPV6_VERSION_TRAFFIC_FLOW = 60000000;

    private IPPacket() {
        // Prevent outside initialization
    }

    /**
     * Write IPv4 Packet for UDP Packet
     *
     * @param byteBuf    ByteBuf where IP Packet data will be set
     * @param payload    Payload of UDP
     * @param srcAddress Source IPv4 Address
     * @param dstAddress Destination IPv4 Address
     */
    static void writeUDPv4(ByteBuf byteBuf, ByteBuf payload, int srcAddress, int dstAddress) {
        writePacketv4(byteBuf, payload, UDP, srcAddress, dstAddress);
    }

    /**
     * Write IPv6 Packet for UDP Packet
     *
     * @param byteBuf    ByteBuf where IP Packet data will be set
     * @param payload    Payload of UDP
     * @param srcAddress Source IPv6 Address
     * @param dstAddress Destination IPv6 Address
     */
    static void writeUDPv6(ByteBuf byteBuf, ByteBuf payload, byte[] srcAddress, byte[] dstAddress) {
        writePacketv6(byteBuf, payload, UDP, srcAddress, dstAddress);
    }

    /**
     * Write IPv4 Packet for TCP Packet
     *
     * @param byteBuf    ByteBuf where IP Packet data will be set
     * @param payload    Payload of TCP
     * @param srcAddress Source IPv4 Address
     * @param dstAddress Destination IPv4 Address
     */
    static void writeTCPv4(ByteBuf byteBuf, ByteBuf payload, int srcAddress, int dstAddress) {
        writePacketv4(byteBuf, payload, TCP, srcAddress, dstAddress);
    }

    /**
     * Write IPv6 Packet for TCP Packet
     *
     * @param byteBuf    ByteBuf where IP Packet data will be set
     * @param payload    Payload of TCP
     * @param srcAddress Source IPv6 Address
     * @param dstAddress Destination IPv6 Address
     */
    static void writeTCPv6(ByteBuf byteBuf, ByteBuf payload, byte[] srcAddress, byte[] dstAddress) {
        writePacketv6(byteBuf, payload, TCP, srcAddress, dstAddress);
    }

    private static void writePacketv4(ByteBuf byteBuf, ByteBuf payload, int protocol, int srcAddress,
                                      int dstAddress) {

        byteBuf.writeByte(0x45);      //  Version + IHL
        byteBuf.writeByte(0x00);      //  DSCP
        byteBuf.writeShort(V4_HEADER_SIZE + payload.readableBytes()); // Length
        byteBuf.writeShort(0x0000);   // Identification
        byteBuf.writeShort(0x0000);   // Fragment
        byteBuf.writeByte(MAX_TTL);   // TTL
        byteBuf.writeByte(protocol);  // Protocol
        byteBuf.writeShort(0);        // Checksum
        byteBuf.writeInt(srcAddress); // Source IPv4 Address
        byteBuf.writeInt(dstAddress); // Destination IPv4 Address
        byteBuf.writeBytes(payload);  // Payload of L4
    }

    private static void writePacketv6(ByteBuf byteBuf, ByteBuf payload, int protocol, byte[] srcAddress,
                                      byte[] dstAddress) {

        byteBuf.writeInt(IPV6_VERSION_TRAFFIC_FLOW); // Version  + Traffic class + Flow label
        byteBuf.writeShort(payload.readableBytes()); // Payload length
        byteBuf.writeByte(protocol & 0xff); // Next header
        byteBuf.writeByte(MAX_TTL);         // Hop limit
        byteBuf.writeBytes(srcAddress);     // Source IPv6 Address
        byteBuf.writeBytes(dstAddress);     // Destination IPv6 Address
        byteBuf.writeBytes(payload);        // Payload of L4
    }
}