dhcpsapi.dll p/invoke

[Iziah]

Hey Guys,

I've got a problem in trying to get the DhcpDeleteClien tInfo method in
the DHCP Server Management API working. I *really* think the issue
revolves around my DHCP_SEARCH_INF O_TYPE enum. Eventually what I want
to get done is a delete from the DHCP server by MAC Address. The code
below works for IPAddress, but not Name or MACAddress. both of those
attempts yield the same error: "87: the parameter is incorrect."

Have a look and tell me what you think:

[StructLayout(La youtKind.Sequen tial)]
public struct DHCP_BINARY_DAT A
{
public int DataLength;
public IntPtr Data;
}

public enum DHCP_SEARCH_INF O_TYPE:int
{
DhcpClientIpAdd ress =0,
DhcpClientHardw areAddress=1,
DhcpClientName= 2
}

[StructLayout(La youtKind.Sequen tial)]
public struct DHCP_SEARCH_INF O
{
public uint SearchType;
public UInt32 ClientIpAddress ;
public DHCP_BINARY_DAT A ClientMacAddres s;
[MarshalAs(Unman agedType.LPWStr )]public string ClientName;

};
[DllImport("dhcp sapi.dll", SetLastError = true, CharSet =
CharSet.Unicode )]
public static extern int DhcpDeleteClien tInfo(
string DHCPServer,
IntPtr searchInfo);
[DllImport("neta pi32.dll", SetLastError = true)]
public extern static int NetApiBufferFre e(IntPtr lpBuffer);

[DllImport("neta pi32.dll", SetLastError = true)]
public extern static int NetApiBufferAll ocate(int ByteCount,ref int
Buffer);


public static void DoDeletionByIP( string IPAddress)
{
string dhcpServer = "n.n.n.n";
DHCP_SEARCH_INF O SearchInfo = new DHCP_SEARCH_INF O();
SearchInfo.Sear chType =
(int)DHCP_SEARC H_INFO_TYPE.Dhc pClientIpAddres s;
char [] dot = ".".ToCharArray ();
char[] zero = "0".ToCharArray ();
string [] Octets= IPAddress.Split (dot[0]);
string HexIP = "";

foreach(string Octet in Octets)
{
HexIP += Convert.ToStrin g(Convert.ToInt 16(Octet), 16).PadLeft(2,
zero[0]);
}


SearchInfo.Clie ntIpAddress = Convert.ToUInt3 2(HexIP, 16);

int bufptr = 0;
int StructSize;
StructSize = Marshal.SizeOf( SearchInfo);
NetApiBufferAll ocate(StructSiz e,ref bufptr);
Marshal.Structu reToPtr(SearchI nfo, (IntPtr)bufptr, true);

int result = DhcpDeleteClien tInfo(dhcpServe r, (IntPtr)bufptr) ;

NetApiBufferFre e((IntPtr)bufpt r);
if(result == 0)
{
Console.WriteLi ne(IPAddress+": Deleted");
}
else
{
int code = 0;
unchecked
{
code = (int)result;
}
Win32Exception ex = new Win32Exception( code);
Console.WriteLi ne(ex.NativeErr orCode + ":" + ex.Message);

}

}
public static void DoDeletionByMAC (string MACAddress)
{
string dhcpServer = "n.n.n.n";
DHCP_SEARCH_INF O SearchInfo = new DHCP_SEARCH_INF O();
SearchInfo.Sear chType =
(int)DHCP_SEARC H_INFO_TYPE.Dhc pClientIpAddres s;

DHCP_BINARY_DAT A macAddress = new DHCP_BINARY_DAT A();
int discarded = 0;
byte [] macArray = HexEncoding.Get Bytes(MACAddres s, out discarded);
int size=0;
for(int i=0;i<macArray. Length;i++)
{
size += Marshal.SizeOf( macArray[i]);
}
IntPtr pnt = Marshal.AllocHG lobal(size);
Marshal.Copy(ma cArray, 0, pnt, macArray.Length );
macAddress.Data = pnt;
macAddress.Data Length= size;
SearchInfo.Clie ntMacAddress = macAddress;

int bufptr = 0;
int StructSize;
StructSize = Marshal.SizeOf( SearchInfo);
NetApiBufferAll ocate(StructSiz e,ref bufptr);
Marshal.Structu reToPtr(SearchI nfo, (IntPtr)bufptr, true);

int result = DhcpDeleteClien tInfo(dhcpServe r, (IntPtr)bufptr) ;

NetApiBufferFre e((IntPtr)bufpt r);
if(result == 0)
{
Console.WriteLi ne(MACAddress+" : Deleted");
}
else
{
int code = 0;
unchecked
{
code = (int)result;
}
Win32Exception ex = new Win32Exception( code);
Console.WriteLi ne(ex.NativeErr orCode + ":" + ex.Message);

}
}

public static void DoDeletionByNam e(string Name)
{
string dhcpServer = "n.n.n.n";
DHCP_SEARCH_INF O SearchInfo = new DHCP_SEARCH_INF O();
SearchInfo.Sear chType = (int)DHCP_SEARC H_INFO_TYPE.Dhc pClientName;
SearchInfo.Clie ntName = Name;
int bufptr = 0;
int StructSize;
StructSize = Marshal.SizeOf( SearchInfo);
NetApiBufferAll ocate(StructSiz e,ref bufptr);
Marshal.Structu reToPtr(SearchI nfo, (IntPtr)bufptr, true);

int result = DhcpDeleteClien tInfo(dhcpServe r, (IntPtr)bufptr) ;

NetApiBufferFre e((IntPtr)bufpt r);
if(result == 0)
{
Console.WriteLi ne(Name+": Deleted");
}
else
{
int code = 0;
unchecked
{
code = (int)result;
}
Win32Exception ex = new Win32Exception( code);
Console.WriteLi ne(ex.NativeErr orCode + ":" + ex.Message);

}

}

Any extra information would be greatly appreciated.

Thanks......