public static void GetDHCPleases(List <string> DHCPServerIPs, IDictionary <string, string> MACIPmapping)
{
uint parsedMask = 0; //Gets all scopes
uint resumeHandle = 0;
uint numClientsRead = 0;
uint totalClients = 0;
IntPtr info_array_ptr = IntPtr.Zero;
foreach (string DHCPServer in DHCPServerIPs)
{
uint response = DhcpEnumSubnetClients(DHCPServer, parsedMask, ref resumeHandle, 65536, out info_array_ptr, ref numClientsRead, ref totalClients);
//If no results, next DHCP server
if ((int)info_array_ptr == 0)
{
continue;
}
//Set up client array casted to a DHCP_CLIENT_INFO_ARRAY using the pointer from the response object above
DHCP_CLIENT_INFO_ARRAY rawClients = (DHCP_CLIENT_INFO_ARRAY)Marshal.PtrToStructure(info_array_ptr, typeof(DHCP_CLIENT_INFO_ARRAY));
// Loop through the clients structure inside rawClients adding to the dchpClient collection
IntPtr current = rawClients.Clients;
for (int i = 0; i < (int)rawClients.NumElements; i++)
{
string machineIP, machineMAC;
//Create machine object using the struct
DHCP_CLIENT_INFO rawMachine = (DHCP_CLIENT_INFO)Marshal.PtrToStructure(Marshal.ReadIntPtr(current), typeof(DHCP_CLIENT_INFO));
var a = BitConverter.GetBytes(rawMachine.ip).Reverse().ToArray();
var b = BitConverter.ToUInt32(a, 0);
//Transform machine information
machineIP = new IPAddress(b).ToString();
machineMAC = string.Format("{0:x2} {1:x2} {2:x2} {3:x2} {4:x2} {5:x2}",
Marshal.ReadByte(rawMachine.mac.Data),
Marshal.ReadByte(rawMachine.mac.Data, 1),
Marshal.ReadByte(rawMachine.mac.Data, 2),
Marshal.ReadByte(rawMachine.mac.Data, 3),
Marshal.ReadByte(rawMachine.mac.Data, 4),
Marshal.ReadByte(rawMachine.mac.Data, 5)).ToUpper();
//Add to mapping object
MACIPmapping.Add(machineMAC, machineIP);
//Move pointer to next machine
current = (IntPtr)((int)current + (int)Marshal.SizeOf(typeof(IntPtr)));
}
}
}
static ArrayList findDhcpClients(string server, string subnet)
{
// set up container for processed clients
ArrayList foundClients = new ArrayList();
// make call to unmanaged code
uint parsedMask = StringIPAddressToUInt32(subnet);
uint resumeHandle = 0;
uint numClientsRead = 0;
uint totalClients = 0;
IntPtr info_array_ptr;
uint response = DhcpEnumSubnetClients(
server,
parsedMask,
ref resumeHandle,
65536,
out info_array_ptr,
ref numClientsRead,
ref totalClients
);
// set up client array casted to a DHCP_CLIENT_INFO_ARRAY
// using the pointer from the response object above
DHCP_CLIENT_INFO_ARRAY rawClients =
(DHCP_CLIENT_INFO_ARRAY)Marshal.PtrToStructure(info_array_ptr, typeof(DHCP_CLIENT_INFO_ARRAY));
// loop through the clients structure inside rawClients
// adding to the dchpClient collection
IntPtr current = rawClients.Clients;
for (int i = 0; i < (int)rawClients.NumElements; i++)
{
// 1. Create machine object using the struct
DHCP_CLIENT_INFO rawMachine =
(DHCP_CLIENT_INFO)Marshal.PtrToStructure(Marshal.ReadIntPtr(current), typeof(DHCP_CLIENT_INFO));
// 2. create new C# dhcpClient object and add to the
// collection (for hassle-free use elsewhere!!)
dhcpClient thisClient = new dhcpClient();
thisClient.ip = UInt32IPAddressToString(rawMachine.ip);
thisClient.hostname = rawMachine.ClientName;
thisClient.mac = String.Format("{0:x2}{1:x2}.{2:x2}{3:x2}.{4:x2}{5:x2}",
Marshal.ReadByte(rawMachine.mac.Data),
Marshal.ReadByte(rawMachine.mac.Data, 1),
Marshal.ReadByte(rawMachine.mac.Data, 2),
Marshal.ReadByte(rawMachine.mac.Data, 3),
Marshal.ReadByte(rawMachine.mac.Data, 4),
Marshal.ReadByte(rawMachine.mac.Data, 5));
foundClients.Add(thisClient);
// 3. move pointer to next machine
current = (IntPtr)((int)current + (int)Marshal.SizeOf(typeof(IntPtr)));
}
return foundClients;
}
