Yes, I removed the array declaration because the size is 1 (ANYSIZE_ARRAY)
in the sample.
The problem with embedded arrays and variable length structures is realated
to the Interop marshaller, not C#.
The current version of the marshaller cannot handle them, to solve this you
have a number of options:
- Use Managed C++ which, as I told you, is THE interop language in .NET,
there are way too many opportunities to make mistakes while porting C/C++
header files to C# P/Invoke signatures.
- Pass managed pointers pointing to native memory (alloacted with
Marshal.AllocHGlobal or Marshal.AllocCoTaskMem) the API's and use
Marshal.StructureToPtr and Marshal.PtrToStructure to access the struct
fields before and after the call ( this is why I included StructInspector()
in the sample to get you started).
- Use unsafe code blocks and pointers.
- Flatten the structure and use arryays of blittable types to replace the
embedded struct array's, here's a sample.
note: non of the options (except MC++) solve the problem of marshalling
variable length structs.).
using System;
using System.Runtime.InteropServices;
using System.Security.Principal;
namespace Willys
{
[StructLayout(LayoutKind.Sequential)]
public struct _PRIVILEGE_SET
{
public uint PrivilegeCount;
public uint Control;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 6)] // 2 privilege
structs flatten to be 6 int's !!!!
public int[] Privilege_1;
}
[StructLayout(LayoutKind.Sequential)]
public struct LUID_AND_ATTRIBUTES
{
public LUID Luid;
public uint Attributes;
}
[StructLayout(LayoutKind.Sequential)]
public struct LUID
{
public uint LowPart;
public uint HighPart;
}
public sealed class StructInspector
{
.......// see previous posting
}
class Tester
{
[DllImport("advapi32.dll", EntryPoint="PrivilegeCheck", SetLastError=true)]
public static extern bool PrivilegeCheck( IntPtr ClientToken, ref
_PRIVILEGE_SET RequiredPrivileges, ref int pfResult);
[DllImport("advapi32.dll", SetLastError=true, CharSet=CharSet.Auto)]
public extern static bool LookupPrivilegeValue(string lpSystemName, string
lpName, ref int pLuid);
public const int PRIVILEGE_SET_ALL_NECESSARY = 1;
static void Main()
{
int result = 0;
IntPtr hToken;
uint privCount = 2;
// Setting up the PRIVILEGE_SET to contain "SeImpersonatePrivilege" and
"SeChangeNotifyPrivilege"
_PRIVILEGE_SET ps = new _PRIVILEGE_SET();
ps.PrivilegeCount = privCount;
ps.Privilege_1 = new int[privCount * 3]; // allocate 2 * 3 int's each
privilege takes 3 int's)
ps.Control = PRIVILEGE_SET_ALL_NECESSARY ; // or 0 if any of
if (!LookupPrivilegeValue(null, "SeImpersonatePrivilege",ref
ps.Privilege_1[0]))
Console.WriteLine("<LookupPrivilegeValue> Win32 Error {0}",
Marshal.GetLastWin32Error());
if (!LookupPrivilegeValue(null, "SeChangeNotifyPrivilege",ref
ps.Privilege_1[3]))
Console.WriteLine("<LookupPrivilegeValue> Win32 Error {0}",
Marshal.GetLastWin32Error());
StructInspector.DisplayStruct(ps);
WindowsIdentity.Impersonate(WindowsIdentity.GetCurrent().Token);
hToken = WindowsIdentity.GetCurrent().Token;
Console.WriteLine("Token used: " + hToken);
if(!PrivilegeCheck(hToken, ref ps, ref result))
Console.WriteLine("<PrivilegeCheck> Win32 Error {0}",
Marshal.GetLastWin32Error());
Console.WriteLine("Privilege set '{0}'", Convert.ToBoolean(result));
StructInspector.DisplayStruct(ps);
}
}
}
Willy.
