DhcpGetClassInfo

// DHCPSAPI.dll
#include <windows.h>

DWORD DhcpGetClassInfo(
    LPWSTR ServerIpAddress,   // optional
    DWORD ReservedMustBeZero,
    DHCP_CLASS_INFO* PartialClassInfo,
    DHCP_CLASS_INFO** FilledClassInfo
);

<DllImport("DHCPSAPI.dll", ExactSpelling:=True)>
Public Shared Function DhcpGetClassInfo(
    <MarshalAs(UnmanagedType.LPWStr)> ServerIpAddress As String,   ' LPWSTR optional
    ReservedMustBeZero As UInteger,   ' DWORD
    PartialClassInfo As IntPtr,   ' DHCP_CLASS_INFO* in/out
    FilledClassInfo As IntPtr   ' DHCP_CLASS_INFO** in/out
) As UInteger
End Function

' ServerIpAddress : LPWSTR optional
' ReservedMustBeZero : DWORD
' PartialClassInfo : DHCP_CLASS_INFO* in/out
' FilledClassInfo : DHCP_CLASS_INFO** in/out
Declare PtrSafe Function DhcpGetClassInfo Lib "dhcpsapi" ( _
    ByVal ServerIpAddress As LongPtr, _
    ByVal ReservedMustBeZero As Long, _
    ByVal PartialClassInfo As LongPtr, _
    ByVal FilledClassInfo As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

DhcpGetClassInfo = ctypes.windll.dhcpsapi.DhcpGetClassInfo
DhcpGetClassInfo.restype = wintypes.DWORD
DhcpGetClassInfo.argtypes = [
    wintypes.LPCWSTR,  # ServerIpAddress : LPWSTR optional
    wintypes.DWORD,  # ReservedMustBeZero : DWORD
    ctypes.c_void_p,  # PartialClassInfo : DHCP_CLASS_INFO* in/out
    ctypes.c_void_p,  # FilledClassInfo : DHCP_CLASS_INFO** in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('DHCPSAPI.dll')
DhcpGetClassInfo = Fiddle::Function.new(
  lib['DhcpGetClassInfo'],
  [
    Fiddle::TYPE_VOIDP,  # ServerIpAddress : LPWSTR optional
    -Fiddle::TYPE_INT,  # ReservedMustBeZero : DWORD
    Fiddle::TYPE_VOIDP,  # PartialClassInfo : DHCP_CLASS_INFO* in/out
    Fiddle::TYPE_VOIDP,  # FilledClassInfo : DHCP_CLASS_INFO** in/out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "dhcpsapi")]
extern "system" {
    fn DhcpGetClassInfo(
        ServerIpAddress: *mut u16,  // LPWSTR optional
        ReservedMustBeZero: u32,  // DWORD
        PartialClassInfo: *mut DHCP_CLASS_INFO,  // DHCP_CLASS_INFO* in/out
        FilledClassInfo: *mut *mut DHCP_CLASS_INFO  // DHCP_CLASS_INFO** in/out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("DHCPSAPI.dll")]
public static extern uint DhcpGetClassInfo([MarshalAs(UnmanagedType.LPWStr)] string ServerIpAddress, uint ReservedMustBeZero, IntPtr PartialClassInfo, IntPtr FilledClassInfo);
"@
$api = Add-Type -MemberDefinition $sig -Name 'DHCPSAPI_DhcpGetClassInfo' -Namespace Win32 -PassThru
# $api::DhcpGetClassInfo(ServerIpAddress, ReservedMustBeZero, PartialClassInfo, FilledClassInfo)

#uselib "DHCPSAPI.dll"
#func global DhcpGetClassInfo "DhcpGetClassInfo" sptr, sptr, sptr, sptr
; DhcpGetClassInfo ServerIpAddress, ReservedMustBeZero, varptr(PartialClassInfo), varptr(FilledClassInfo)   ; 戻り値は stat
; ServerIpAddress : LPWSTR optional -> "sptr"
; ReservedMustBeZero : DWORD -> "sptr"
; PartialClassInfo : DHCP_CLASS_INFO* in/out -> "sptr"
; FilledClassInfo : DHCP_CLASS_INFO** in/out -> "sptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "DHCPSAPI.dll"
#cfunc global DhcpGetClassInfo "DhcpGetClassInfo" wstr, int, var, var
; res = DhcpGetClassInfo(ServerIpAddress, ReservedMustBeZero, PartialClassInfo, FilledClassInfo)
; ServerIpAddress : LPWSTR optional -> "wstr"
; ReservedMustBeZero : DWORD -> "int"
; PartialClassInfo : DHCP_CLASS_INFO* in/out -> "var"
; FilledClassInfo : DHCP_CLASS_INFO** in/out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; DWORD DhcpGetClassInfo(LPWSTR ServerIpAddress, DWORD ReservedMustBeZero, DHCP_CLASS_INFO* PartialClassInfo, DHCP_CLASS_INFO** FilledClassInfo)
#uselib "DHCPSAPI.dll"
#cfunc global DhcpGetClassInfo "DhcpGetClassInfo" wstr, int, var, var
; res = DhcpGetClassInfo(ServerIpAddress, ReservedMustBeZero, PartialClassInfo, FilledClassInfo)
; ServerIpAddress : LPWSTR optional -> "wstr"
; ReservedMustBeZero : DWORD -> "int"
; PartialClassInfo : DHCP_CLASS_INFO* in/out -> "var"
; FilledClassInfo : DHCP_CLASS_INFO** in/out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	dhcpsapi = windows.NewLazySystemDLL("DHCPSAPI.dll")
	procDhcpGetClassInfo = dhcpsapi.NewProc("DhcpGetClassInfo")
)

// ServerIpAddress (LPWSTR optional), ReservedMustBeZero (DWORD), PartialClassInfo (DHCP_CLASS_INFO* in/out), FilledClassInfo (DHCP_CLASS_INFO** in/out)
r1, _, err := procDhcpGetClassInfo.Call(
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(ServerIpAddress))),
	uintptr(ReservedMustBeZero),
	uintptr(PartialClassInfo),
	uintptr(FilledClassInfo),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function DhcpGetClassInfo(
  ServerIpAddress: PWideChar;   // LPWSTR optional
  ReservedMustBeZero: DWORD;   // DWORD
  PartialClassInfo: Pointer;   // DHCP_CLASS_INFO* in/out
  FilledClassInfo: Pointer   // DHCP_CLASS_INFO** in/out
): DWORD; stdcall;
  external 'DHCPSAPI.dll' name 'DhcpGetClassInfo';

result := DllCall("DHCPSAPI\DhcpGetClassInfo"
    , "WStr", ServerIpAddress   ; LPWSTR optional
    , "UInt", ReservedMustBeZero   ; DWORD
    , "Ptr", PartialClassInfo   ; DHCP_CLASS_INFO* in/out
    , "Ptr", FilledClassInfo   ; DHCP_CLASS_INFO** in/out
    , "UInt")   ; return: DWORD

●DhcpGetClassInfo(ServerIpAddress, ReservedMustBeZero, PartialClassInfo, FilledClassInfo) = DLL("DHCPSAPI.dll", "dword DhcpGetClassInfo(char*, dword, void*, void*)")
# 呼び出し: DhcpGetClassInfo(ServerIpAddress, ReservedMustBeZero, PartialClassInfo, FilledClassInfo)
# ServerIpAddress : LPWSTR optional -> "char*"
# ReservedMustBeZero : DWORD -> "dword"
# PartialClassInfo : DHCP_CLASS_INFO* in/out -> "void*"
# FilledClassInfo : DHCP_CLASS_INFO** in/out -> "void*"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。