NTSTATUS
RtlQueryInformationAcl(
  IN  PACL Acl,
  OUT PVOID AclInformation,
  IN  ULONG AclInformationLength,
  IN  ACL_INFORMATION_CLASS AclInformationClass
  );

Routine Description:

    This routine returns to the caller information about an ACL.  The requested
    information can be AclRevisionInformation, or AclSizeInformation.

Arguments:

    Acl - Supplies the Acl being examined

    AclInformation - Supplies the buffer to receive the information being
        requested

    AclInformationLength - Supplies the length of the AclInformation buffer
        in bytes

    AclInformationClass - Supplies the type of information being requested

Return Value:

    NTSTATUS - STATUS_SUCCESS if successful and an appropriate error
        status otherwise