public DHCPPacketView(DHCPMessageType messageType)
{
Packet = new DHCPPacket();
DHCPMessageType = messageType;
Hops = 0;
TimeElapsed = TimeSpan.Zero;
BroadcastFlag = false;
Packet.sname = string.Empty;
Packet.file = string.Empty;
Packet.magicNumber = DHCPPacket.DHCPMagicNumber;
ClientIP = IPAddress.Any;
YourIP = IPAddress.Any;
NextServerIP = IPAddress.Any;
RelayAgentIP = IPAddress.Any;
}
public void SendDHCPMessage(DHCPMessageType messageType, DHCPTransaction transaction)
{
//mac announced itself, established IP etc....
//send the offer to the mac
byte[] subnet;
byte[] hostId;
byte[] dataToSend;
//we shall leave everything as is structure wise
//shall CHANGE the type to OFFER
//shall set the client's IP-Address
try
{
//change message type to reply
transaction.Message.D_op = 2;
//subnet
subnet = transaction.Data.SubMask.GetAddressBytes();
//create your ip address
transaction.Message.D_yiaddr = transaction.Data.IPAddr.GetAddressBytes();
//Host ID
hostId = System.Text.Encoding.ASCII.GetBytes(transaction.Data.ServerName);
CreateOptionStruct(ref transaction, messageType);
//send the data to the unit
dataToSend = BuildDataStructure(transaction.Message);
udp.SendData(dataToSend);
}
catch (Exception)
{
// TODO: handle exception
// Console.WriteLine(ex.Message);
}
finally
{
subnet = null;
//LeaseTime= null;
hostId = null;
dataToSend = null;
}
}
public DHCPOptionDHCPMessageType(int optionLength, byte[] buffer, long offset)
{
MessageType = (DHCPMessageType)Convert.ToInt32(buffer[offset]);
}
public DHCPOptionDHCPMessageType(DHCPMessageType messageType)
{
MessageType = messageType;
}
private void AddDHCPMessageType(ref byte[] vend, ref int idx, DHCPMessageType type)
{
vend[idx++] = 53;
vend[idx++] = 0x01;
vend[idx++] = (byte)type;
}
private void CreateOptionStruct(ref DHCPTransaction transaction, DHCPMessageType optionReplayMessage)
{
byte[] parameterRequestList;
byte[] ipAddress;
byte[] leaseTime;
byte[] serverIp;
try
{
//we look for the parameter request list
parameterRequestList = GetOptionData(DHCPOption.ParameterRequestList, transaction);
//erase the options array, and set the message type to ack
transaction.Message.D_options = null;
CreateOptionElement(DHCPOption.DHCPMessageTYPE, new byte[] { (byte)optionReplayMessage }, ref transaction.Message.D_options);
//server identifier, my IP
serverIp = transaction.Data.MyIP.GetAddressBytes();
CreateOptionElement(DHCPOption.ServerIdentifier, serverIp, ref transaction.Message.D_options);
// parameterRequestList contains the option data in a byte that is requested by the unit
foreach (byte i in parameterRequestList)
{
ipAddress = null;
switch ((DHCPOption)i)
{
case DHCPOption.SubnetMask:
ipAddress = transaction.Data.SubMask.GetAddressBytes();
break;
case DHCPOption.Router:
ipAddress = transaction.Data.RouterIP.GetAddressBytes();
break;
case DHCPOption.DomainNameServer:
ipAddress = transaction.Data.DomainIP.GetAddressBytes();
break;
case DHCPOption.DomainName:
ipAddress = System.Text.Encoding.ASCII.GetBytes(transaction.Data.ServerName);
break;
case DHCPOption.ServerIdentifier:
ipAddress = transaction.Data.MyIP.GetAddressBytes();
break;
case DHCPOption.LogServer:
ipAddress = System.Text.Encoding.ASCII.GetBytes(transaction.Data.LogServerIP);
break;
case DHCPOption.NetBIOSoverTCPIPNameServer:
break;
}
if (ipAddress != null)
{
CreateOptionElement((DHCPOption)i, ipAddress, ref transaction.Message.D_options);
}
}
//lease time
leaseTime = new byte[4];
leaseTime[3] = (byte)(transaction.Data.LeaseTime);
leaseTime[2] = (byte)(transaction.Data.LeaseTime >> 8);
leaseTime[1] = (byte)(transaction.Data.LeaseTime >> 16);
leaseTime[0] = (byte)(transaction.Data.LeaseTime >> 24);
CreateOptionElement(DHCPOption.IPAddressLeaseTime, leaseTime, ref transaction.Message.D_options);
CreateOptionElement(DHCPOption.RenewalTimeValue_T1, leaseTime, ref transaction.Message.D_options);
CreateOptionElement(DHCPOption.RebindingTimeValue_T2, leaseTime, ref transaction.Message.D_options);
//create the end option
Array.Resize(ref transaction.Message.D_options, transaction.Message.D_options.Length + 1);
Array.Copy(new byte[] { 255 }, 0, transaction.Message.D_options, transaction.Message.D_options.Length - 1, 1);
}
catch (Exception)
{
// TODO: handle exception
// Console.WriteLine(ex.Message);
}
finally
{
leaseTime = null;
parameterRequestList = null;
ipAddress = null;
}
}
public DHCPPacket(byte[] data)
{
DHCPHdr = DecodeBytes(data);
if (DHCPHdr.Magic != 0x63538263)
{
Malformed = true;
return;
}
if (DHCPHdr.MACLength > 16)
{
Malformed = true;
return;
}
for (int i = 0xF0; i < data.Length;)
{
if (data[i] == 0xFF)
{
break;
}
if (data.Length - i < 2)
{
Malformed = true;
break;
}
DHCPOption o = new DHCPOption();
o.Type = data[i + 0];
o.Size = data[i + 1];
if (o.Type == 0 || o.Size == 0)
{
Malformed = true;
break;
}
if (data.Length - (i + o.Size) < 0)
{
Malformed = true;
break;
}
o.Data = new byte[o.Size];
Buffer.BlockCopy(data, i + 2, o.Data, 0, o.Size);
DHCPOptions.Add(o);
i += 2 + o.Size;
}
foreach (DHCPOption o in DHCPOptions)
{
switch (o.Type)
{
case 97:
if (o.Size != 17)
{
Malformed = true;
continue;
}
DHCP97ClientUUID = BytesToString(o.Data, 1);
break;
case 61:
//if (o.Size != 17)
//{
// Malformed = true;
// continue;
//}
DHCP61ClientGUID = BytesToString(o.Data, 1);
break;
case 55:
DHCP9ReqParameterList = new List <byte>();
foreach (byte b in o.Data)
{
if (b == 0 || b == 0xff)
{
Malformed = true;
}
if (DHCP9ReqParameterList.Contains(b) == false)
{
DHCP9ReqParameterList.Add(b);
}
}
break;
case 53:
if (o.Size != 1)
{
Malformed = true;
continue;
}
DHCP53MessageType = (DHCPMessageType)o.Data[0];
break;
case 57:
if (o.Size != 2)
{
Malformed = true;
continue;
}
DHCP57MessageLength = BitConverter.ToUInt16(o.Data.Reverse().ToArray(), 0);
break;
case 60:
if (o.Size != 32)
{
Malformed = true;
continue;
}
DHCP60ClassIdentifier = Encoding.ASCII.GetString(o.Data);
break;
case 66:
DHCP66BootServer = Encoding.ASCII.GetString(o.Data).NullTrim();
break;
case 67:
DHCP67BootFilename = Encoding.ASCII.GetString(o.Data).NullTrim();
break;
case 93:
if (o.Size != 2)
{
Malformed = true;
continue;
}
DHCP93Architecture = (DHCPArchitecture)BitConverter.ToUInt16(o.Data.Reverse().ToArray(), 0);
break;
case 94:
if (o.Size != 3)
{
Malformed = true;
continue;
}
if (o.Data[0] == 1)
{
DHCP94ClientNIC = "UNDI.";
}
else
{
DHCP94ClientNIC = "UNKN.";
}
DHCP94ClientNIC += o.Data[1].ToString("0") + "." + o.Data[2].ToString("0");
break;
default:
Debug.WriteLine("Unknown code: " + o.Type.ToString() + " (0x" + o.Type.ToString("X2") + ")");
break;
}
}
Flags = DHCPHdr.Flags;
OperationCode = DHCPHdr.OperationCode;
HardwareType = DHCPHdr.HardwareType;
XID = DHCPHdr.XID;
IPClient = new IPAddress(DHCPHdr.CIAddr);
IPYours = new IPAddress(DHCPHdr.YIAddr);
IPServer = new IPAddress(DHCPHdr.SIAddr);
IPGateway = new IPAddress(DHCPHdr.GIAddr);
MacAddress = new byte[DHCPHdr.MACLength];
Buffer.BlockCopy(DHCPHdr.CHAddr, 0, MacAddress, 0, DHCPHdr.MACLength);
Servername = Encoding.ASCII.GetString(DHCPHdr.SName).NullTrim();
BootFile = Encoding.ASCII.GetString(DHCPHdr.File).NullTrim();
}
public DHCPOptionMessageType(DHCPMessageType messageType)
: base(DHCPOption.MessageType)
{
this.MessageType = messageType;
}
