io.netty.handler.pcap.UDPPacket 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 UDPPacket {
private static final short UDP_HEADER_SIZE = 8;
private UDPPacket() {
// Prevent outside initialization
}
/**
* Write UDP Packet
*
* @param byteBuf ByteBuf where Packet data will be set
* @param payload Payload of this Packet
* @param srcPort Source Port
* @param dstPort Destination Port
*/
static void writePacket(ByteBuf byteBuf, ByteBuf payload, int srcPort, int dstPort) {
byteBuf.writeShort(srcPort); // Source Port
byteBuf.writeShort(dstPort); // Destination Port
byteBuf.writeShort(UDP_HEADER_SIZE + payload.readableBytes()); // UDP Header Length + Payload Length
byteBuf.writeShort(0x0001); // Checksum
byteBuf.writeBytes(payload); // Payload of Data
}
}