&@msdn=http://search.microsoft.com/search/results.aspx?qu=$$$
C# Signature:
/// <summary>
/// The DhcpGetClientInfo function returns information about a specific DHCP client.
/// </summary>
/// <param name="ServerIpAddress">[in] Unicode string that specifies the IP address of the DHCP server.</param>
/// <param name="SearchInfo">[in] DHCP_SEARCH_INFO structure that contains the parameters for the search. </param>
/// <param name="ClientInfo">[out] Pointer to a DHCP_CLIENT_INFO structure that contains information describing the DHCP client that most closely matches the provided search parameters. If no client is found, this parameter will be null.</param>
/// <returns>This function returns ERROR_SUCCESS upon a successful call. Otherwise, it returns one of the DHCP Server Management API Error Codes.</returns>
[DllImport("dhcpsapi.dll")]
static extern UInt32 DhcpGetClientInfo(
[MarshalAs(UnmanagedType.LPWStr)]
String ServerIpAddress,
ref DHCP_CLIENT_SEARCH_IP_ADDRESS si,
out IntPtr ci);
VB Signature:
''' <summary>
''' The DhcpGetClientInfo function returns information about a specific DHCP client.
''' </summary>
''' <param name="ServerIpAddress">[in] Unicode string that specifies the IP address of the DHCP server.
''' </param>
''' <param name="SearchInfo">[in] DHCP_SEARCH_INFO structure that contains the parameters for the search.
''' </param>
''' <param name="ClientInfo">[out] Pointer to a DHCP_CLIENT_INFO structure that contains information describing the DHCP client that most closely matches the provided search parameters. If no client is found, this parameter will be null.
''' </param>
''' <returns>This function returns ERROR_SUCCESS upon a successful call. Otherwise, it returns one of the DHCP Server Management API Error Codes.
''' </returns>
<DllImport("dhcpsapi.dll", SetLastError:=True, CharSet:=CharSet.Unicode)> _
Public Shared Function DhcpGetClientInfo( _
ByVal ServerIpAddress As String, _
ByRef SearchInfo As DHCP_SEARCH_INFO, _
ByRef ClientInfo As IntPtr) As UInt32
End Function
User-Defined Types:
DHCP_SEARCH_INFO, DHCP_CLIENT_SEARCH_IP_ADDRESS
Alternative Managed API:
Do you know one? Please contribute it!
Notes:
VB Signature and sample code added by BlUNt, adapted from C# Samples
Tips & Tricks:
Completed library DHCP functions.
http://www.rupj.net/portfolio/dhcp-web-services.html
Sample VB Code:
Public Function GetClientInfo(ByVal serverIP As String, ByVal clientIP As String)
Dim DHCPResult As UInt32 = 0
Try
Dim searchInfo As New DHCP_SEARCH_INFO
Dim searchInfoType As DHCP_SEARCH_INFO_TYPE = DHCP_SEARCH_INFO_TYPE.DhcpClientIpAddress
searchInfo.SearchType = searchInfoType
searchInfo.ClientIpAddress = ConvertIPAddress(clientIP)
Dim hClientInfo As IntPtr
DHCPResult = DhcpGetClientInfo(serverIP, searchInfo, hClientInfo)
If DHCPResult = ERROR_SUCCESS And Not hClientInfo = IntPtr.Zero Then
Dim clientInfo As DHCP_CLIENT_INFO = Marshal.PtrToStructure(hClientInfo, GetType(DHCP_CLIENT_INFO))
Return clientInfo
End If
Return Nothing
Catch ex As Exception
Console.WriteLine(ex.Message)
Return Nothing
End Try
End Function
Public Shared Function ConvertIPAddress(ByVal ipAddress As String) As UInt32
Dim dot As Char() = ".".ToCharArray()
Dim zero As Char() = "0".ToCharArray()
Dim Octets As String() = ipAddress.Split(dot(0))
Dim HexIP As String = ""
For Each Octet As String In Octets
HexIP += Convert.ToString(Convert.ToInt16(Octet), 16).PadLeft(2, zero(0))
Next
Return Convert.ToUInt32(HexIP, 16)
End Function
Sample Code:
static void Main()
{
String ServerIpAddress = "192.168.0.250";
UInt32 DHCPResult = 0;
try
{
DHCP_SEARCH_INFO searchInfo = new DHCP_SEARCH_INFO();
DHCP_SEARCH_INFO_TYPE searchInfoType = DHCP_SEARCH_INFO_TYPE.DhcpClientIpAddress;
searchInfo.SearchType = searchInfoType;
searchInfo.ClientIpAddress = ConvertIPAddress("192.168.0.10");
IntPtr pClientInfo;
DHCPResult = DhcpGetClientInfo(ServerIpAddress, ref searchInfo, out pClientInfo);
if (DHCPResult == 0 && pClientInfo != IntPtr.Zero)
{
DHCP_CLIENT_INFO clientInfo = (DHCP_CLIENT_INFO)Marshal.PtrToStructure(pClientInfo, typeof(DHCP_CLIENT_INFO));
Console.WriteLine(DHCPResult.ToString() + " Client Info: " + clientInfo.ClientName);
}
else
{
Console.WriteLine(DHCPResult.ToString() + " Failed");
}
}
public static UInt32 ConvertIPAddress(string ipAddress)
{
char[] dot = ".".ToCharArray();
char[] zero = "0".ToCharArray();
string[] Octets = ipAddress.Split(dot[0]);
string HexIP = "";
foreach (string Octet in Octets)
{
HexIP += Convert.ToString(Convert.ToInt16(Octet), 16).PadLeft(2, zero[0]);
}
return Convert.ToUInt32(HexIP, 16);
}
C# Sample for getting a MAC-Address to a specified IP
public string GetClientInfoByIp(string server, string client)
{
DHCP_CLIENT_SEARCH_IP_ADDRESS si = new DHCP_CLIENT_SEARCH_IP_ADDRESS();
si.SearchType = (int)DHCP_SEARCH_INFO_TYPE.DhcpClientIpAddress ;
si.ClientIpAddress = StringIPAddressToUint32(client);
UInt32 res = 0;
try
{
IntPtr oInfo;
res = DhcpGetClientInfo(new String(server.ToCharArray()), ref si, out oInfo);
if (res == 0 && oInfo != IntPtr.Zero)
{
DHCP_CLIENT_INFO info = (DHCP_CLIENT_INFO)Marshal.PtrToStructure(oInfo, typeof(DHCP_CLIENT_INFO));
String mac = String.Format("{0:x2}-{1:x2}-{2:x2}-{3:x2}-{4:x2}-{5:x2}",
Marshal.ReadByte(info.ClientHardwareAddress.Data,0),
Marshal.ReadByte(info.ClientHardwareAddress.Data,1),
Marshal.ReadByte(info.ClientHardwareAddress.Data,2),
Marshal.ReadByte(info.ClientHardwareAddress.Data,3),
Marshal.ReadByte(info.ClientHardwareAddress.Data,4),
Marshal.ReadByte(info.ClientHardwareAddress.Data,5));
return mac;
}
else
{
Console.WriteLine("Failed!");
return "00-00-00-00-00-00";
}
}
catch(Exception e)
{
Console.WriteLine(e);
return "00-00-00-00-00-00";
}
}
public uint StringIPAddressToUint32(string ip_string)
{
IPAddress ipa = IPAddress.Parse(ip_string);
byte[] ip_bytes = ipa.GetAddressBytes();
uint ip_uint = (uint)ip_bytes[0] << 24;
ip_uint+= (uint)ip_bytes[1] << 16;
ip_uint+= (uint)ip_bytes[2] << 8;
ip_uint+= (uint)ip_bytes[3];
return ip_uint;
}
static void Main()
{
String dhcpServerIP = "192.168.1.1";
String clientIP = "182.168.1.120";
Console.WriteLine("MAC-Adress for " + clientIp + " is " + GetClientInfoByIp(dhcpServerIP, clientIp));
}
