io.netty.handler.pcap.EthernetPacket Maven / Gradle / Ivy
/*
* 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 EthernetPacket {
/**
* MAC Address: 00:00:5E:00:53:00
*/
private static final byte[] DUMMY_SOURCE_MAC_ADDRESS = new byte[]{0, 0, 94, 0, 83, 0};
/**
* MAC Address: 00:00:5E:00:53:FF
*/
private static final byte[] DUMMY_DESTINATION_MAC_ADDRESS = new byte[]{0, 0, 94, 0, 83, -1};
/**
* IPv4
*/
private static final int V4 = 0x0800;
/**
* IPv6
*/
private static final int V6 = 0x86dd;
private EthernetPacket() {
// Prevent outside initialization
}
/**
* Write IPv4 Ethernet Packet. It uses a dummy MAC address for both source and destination.
*
* @param byteBuf ByteBuf where Ethernet Packet data will be set
* @param payload Payload of IPv4
*/
static void writeIPv4(ByteBuf byteBuf, ByteBuf payload) {
writePacket(byteBuf, payload, DUMMY_SOURCE_MAC_ADDRESS, DUMMY_DESTINATION_MAC_ADDRESS, V4);
}
/**
* Write IPv6 Ethernet Packet. It uses a dummy MAC address for both source and destination.
*
* @param byteBuf ByteBuf where Ethernet Packet data will be set
* @param payload Payload of IPv6
*/
static void writeIPv6(ByteBuf byteBuf, ByteBuf payload) {
writePacket(byteBuf, payload, DUMMY_SOURCE_MAC_ADDRESS, DUMMY_DESTINATION_MAC_ADDRESS, V6);
}
/**
* Write IPv6 Ethernet Packet
*
* @param byteBuf ByteBuf where Ethernet Packet data will be set
* @param payload Payload of IPv6
* @param srcAddress Source MAC Address
* @param dstAddress Destination MAC Address
* @param type Type of Frame
*/
private static void writePacket(ByteBuf byteBuf, ByteBuf payload, byte[] srcAddress, byte[] dstAddress, int type) {
byteBuf.writeBytes(dstAddress); // Destination MAC Address
byteBuf.writeBytes(srcAddress); // Source MAC Address
byteBuf.writeShort(type); // Frame Type (IPv4 or IPv6)
byteBuf.writeBytes(payload); // Payload of L3
}
}