public static DhcpPacket GenerateDhcpDiscoverPacket(Parameters parameters)
{
var packet = new DhcpPacket(new byte[244]);
// Generate a Transaction ID for this request
var xid = new byte[4];
xid[0] = 0xE7;
xid[1] = 0x03;
xid[2] = 0x00;
xid[3] = 0x00;
//XidRandom.NextBytes(xid);
byte[] macAddress = parameters.MacAddress;
// Actual DHCPDISCOVER packet
byte[] data = packet._data;
Array.Copy(xid, 0, data, 4, 4);
Array.Copy(macAddress, 0, data, 28, 6);
// Set the OP Code to BOOTREQUEST
data[0] = 1;
// Set the Hardware Address Type to Ethernet
data[1] = 1;
// Set the Hardware Address Length (number of bytes)
data[2] = 6;
// Set the Broadcast Flag
data[10] = 128;
// Set the Magic Cookie values
data[236] = 99; // D
data[237] = 130; // H
data[238] = 83; // C
data[239] = 99; // P
// Set the DHCPDiscover Message Type Option
data[240] = 53;
data[241] = 1;
data[242] = 1;
// End Option
data[243] = 255;
return packet;
}
private void Write(Packet packet)
{
var ethPacket = packet as EthernetPacket;
if (ethPacket == null)
return;
var ipPacket = ethPacket.Extract(typeof (IPv4Packet)) as IPv4Packet;
if (ipPacket == null)
return;
var udpPacket = ipPacket.Extract(typeof (UdpPacket)) as UdpPacket;
if (udpPacket == null)
return;
var sb = new StringBuilder();
sb.Append(String.Format("{0:yyyyMMdd HHmmss:fff}", DateTime.Now));
sb.Append("\t");
sb.Append(ethPacket.SourceHwAddress);
sb.Append("\t");
sb.Append(ethPacket.DestinationHwAddress);
sb.Append("\t");
sb.Append(ipPacket.SourceAddress);
sb.Append("\t");
sb.Append(ipPacket.DestinationAddress);
sb.Append("\t");
sb.Append(udpPacket.SourcePort);
sb.Append("\t");
sb.Append(udpPacket.DestinationPort);
sb.Append("\t");
var dhcpPacket = new DhcpPacket(udpPacket.PayloadData);
dhcpPacket.ReadPacket(_parameters, sb);
sb.Append("\r\n");
String loggingText = sb.ToString();
File.AppendAllText(_parameters.LogFilename, loggingText);
Console.Write(loggingText);
}
