public void cDhcp_Request(cDHCPStruct d_DHCP, string MacId)
{
string str = string.Empty;
if (MacId.StartsWith(MacMask) == true)
{
//announced so then send the offer
d_DHCP.dData.IPAddr = GetIPAdd();
d_DHCP.dData.SubMask = "255.255.0.0";
d_DHCP.dData.LeaseTime = 2000;
d_DHCP.dData.ServerName = "tiny DHCP Server";
d_DHCP.dData.MyIP = AdapterIP;
d_DHCP.dData.RouterIP = "0.0.0.0";
d_DHCP.dData.LogServerIP = "0.0.0.0";
d_DHCP.dData.DomainIP = "0.0.0.0";
cDhcp.SendDHCPMessage(DHCPMsgType.DHCPACK, d_DHCP);
str = "IP " + d_DHCP.dData.IPAddr + " Assigned to Mac: " + MacId;
}
else
{
str = "Mac: " + MacId + " is not part of the mask!";
}
SimpleDelegate lst = delegate
{
listBox1.Items.Add(str);
};
Invoke(lst);
}
public void cDhcp_Announced(cDHCPStruct d_DHCP, string MacId)
{
string str = string.Empty;
if (MacId.StartsWith(MacMask) == true)
{
//options should be filled with valid data
d_DHCP.dData.IPAddr = GetIPAdd();
d_DHCP.dData.SubMask = "255.255.0.0";
d_DHCP.dData.LeaseTime = 2000;
d_DHCP.dData.ServerName = "Small DHCP Server";
d_DHCP.dData.MyIP = AdapterIP;
d_DHCP.dData.RouterIP = "0.0.0.0";
d_DHCP.dData.LogServerIP = "0.0.0.0";
d_DHCP.dData.DomainIP = "0.0.0.0";
str = "IP requested for Mac: " + MacId;
}
else
{
str = "Mac: " + MacId + " is not part of the mask!";
}
cDhcp.SendDHCPMessage(DHCPMsgType.DHCPOFFER, d_DHCP);
SimpleDelegate lst = delegate
{
listBox1.Items.Add(str);
};
Invoke(lst);
//Application.DoEvents()
}
//get the Message type
//located in the options stream
public DHCPMsgType GetMsgType(cDHCPStruct cdDHCPs)
{
byte[] DData;
try
{
DData = GetOptionData(DHCPOptionEnum.DHCPMessageTYPE, cdDHCPs);
if (DData != null)
{
return((DHCPMsgType)DData[0]);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
return(0);
}
//pass the option type that you require
//parse the option data
//return the data in a byte of what we need
private byte[] GetOptionData(DHCPOptionEnum DHCPTyp, cDHCPStruct cdDHCPs)
{
int DHCPId = 0;
byte DDataID, DataLength = 0;
byte[] dumpData;
try
{
DHCPId = (int)DHCPTyp;
//loop through look for the bit that states that the identifier is there
for (int i = 0; i < cdDHCPs.dStruct.D_options.Length; i++)
{
//at the start we have the code + length
//i has the code, i+1 = length of data, i+1+n = data skip
DDataID = cdDHCPs.dStruct.D_options[i];
if (DDataID == DHCPId)
{
DataLength = cdDHCPs.dStruct.D_options[i + 1];
dumpData = new byte[DataLength];
Array.Copy(cdDHCPs.dStruct.D_options, i + 2, dumpData, 0, DataLength);
return(dumpData);
}
else
{
DataLength = cdDHCPs.dStruct.D_options[i + 1]; //'length of code
i += 1 + DataLength;
} //.endif
} //for
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
dumpData = null;
}
return(null);
}
//mac announced itself, established IP etc....
//send the offer to the mac
public void SendDHCPMessage(DHCPMsgType msgType, cDHCPStruct ddHcpS)
{
byte[] Subn, HostID, 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
ddHcpS.dStruct.D_op = 2; //reply
//subnet
Subn = IPAddress.Parse(ddHcpS.dData.SubMask).GetAddressBytes();
//create your ip address
ddHcpS.dStruct.D_yiaddr = IPAddress.Parse(ddHcpS.dData.IPAddr).GetAddressBytes();
//Host ID
HostID = System.Text.Encoding.ASCII.GetBytes(ddHcpS.dData.ServerName);
CreateOptionStruct(ref ddHcpS, msgType);
//send the data to the unit
DataToSend = BuildDataStructure(ddHcpS.dStruct);
cUdp.SendData(DataToSend);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
Subn = null;
//LeaseTime= null;
HostID = null;
DataToSend = null;
}
}
//private void
public void cUdp_DataRcvd(byte[] DData, IPEndPoint RIpEndPoint)
{
cDHCPStruct ddHcpS;
DHCPMsgType MsgTyp;
//clsDHCP ccDHCP;
string MacID;
try
{
ddHcpS = new cDHCPStruct(DData);
//ccDHCP = new clsDHCP();
//data is now in the structure
//get the msg type
MsgTyp = GetMsgType(ddHcpS);
MacID = ByteToString(ddHcpS.dStruct.D_chaddr, ddHcpS.dStruct.D_hlen);// (string)ddHcpS.dStruct.D_chaddr;
switch (MsgTyp)
{
case DHCPMsgType.DHCPDISCOVER:
//myClass.Process(myLogger);
// a Mac has requested an IP
// discover Msg Has been sent
Announced(ddHcpS, MacID);
break;
case DHCPMsgType.DHCPREQUEST:
Request(ddHcpS, MacID);
break;
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
private void CreateOptionStruct(ref cDHCPStruct ddHcps, DHCPMsgType OptionReplyMsg)
{
byte[] PReqList, t1, LeaseTime, MyIp;
try
{
//we look for the parameter request list
PReqList = GetOptionData(DHCPOptionEnum.ParameterRequestList, ddHcps);
//erase the options array, and set the message type to ack
ddHcps.dStruct.D_options = null;
CreateOptionElement(DHCPOptionEnum.DHCPMessageTYPE, new byte[] { (byte)OptionReplyMsg }, ref ddHcps.dStruct.D_options);
//server identifier, my IP
MyIp = IPAddress.Parse(ddHcps.dData.MyIP).GetAddressBytes();
CreateOptionElement(DHCPOptionEnum.ServerIdentifier, MyIp, ref ddHcps.dStruct.D_options);
//PReqList contains the option data in a byte that is requested by the unit
foreach (byte i in PReqList)
{
t1 = null;
switch ((DHCPOptionEnum)i)
{
case DHCPOptionEnum.SubnetMask:
t1 = IPAddress.Parse(ddHcps.dData.SubMask).GetAddressBytes();
break;
case DHCPOptionEnum.Router:
t1 = IPAddress.Parse(ddHcps.dData.RouterIP).GetAddressBytes();
break;
case DHCPOptionEnum.DomainNameServer:
t1 = IPAddress.Parse(ddHcps.dData.DomainIP).GetAddressBytes();
break;
case DHCPOptionEnum.DomainName:
t1 = System.Text.Encoding.ASCII.GetBytes(ddHcps.dData.ServerName);
break;
case DHCPOptionEnum.ServerIdentifier:
t1 = IPAddress.Parse(ddHcps.dData.MyIP).GetAddressBytes();
break;
case DHCPOptionEnum.LogServer:
t1 = System.Text.Encoding.ASCII.GetBytes(ddHcps.dData.LogServerIP);
break;
case DHCPOptionEnum.NetBIOSoverTCPIPNameServer:
break;
}
if (t1 != null)
{
CreateOptionElement((DHCPOptionEnum)i, t1, ref ddHcps.dStruct.D_options);
}
}
//lease time
LeaseTime = new byte[4];
LeaseTime[3] = (byte)(ddHcps.dData.LeaseTime);
LeaseTime[2] = (byte)(ddHcps.dData.LeaseTime >> 8);
LeaseTime[1] = (byte)(ddHcps.dData.LeaseTime >> 16);
LeaseTime[0] = (byte)(ddHcps.dData.LeaseTime >> 24);
CreateOptionElement(DHCPOptionEnum.IPAddressLeaseTime, LeaseTime, ref ddHcps.dStruct.D_options);
CreateOptionElement(DHCPOptionEnum.RenewalTimeValue_T1, LeaseTime, ref ddHcps.dStruct.D_options);
CreateOptionElement(DHCPOptionEnum.RebindingTimeValue_T2, LeaseTime, ref ddHcps.dStruct.D_options);
//create the end option
Array.Resize(ref ddHcps.dStruct.D_options, ddHcps.dStruct.D_options.Length + 1);
Array.Copy(new byte[] { 255 }, 0, ddHcps.dStruct.D_options, ddHcps.dStruct.D_options.Length - 1, 1);
//send the data to the unit
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
LeaseTime = null;
PReqList = null;
t1 = null;
}
}
