DhcpEnumSubnets

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

DWORD DhcpEnumSubnets(
    LPCWSTR ServerIpAddress,   // optional
    DWORD* ResumeHandle,
    DWORD PreferredMaximum,
    DHCP_IP_ARRAY** EnumInfo,
    DWORD* ElementsRead,
    DWORD* ElementsTotal
);

<DllImport("DHCPSAPI.dll", ExactSpelling:=True)>
Public Shared Function DhcpEnumSubnets(
    <MarshalAs(UnmanagedType.LPWStr)> ServerIpAddress As String,   ' LPCWSTR optional
    ByRef ResumeHandle As UInteger,   ' DWORD* in/out
    PreferredMaximum As UInteger,   ' DWORD
    EnumInfo As IntPtr,   ' DHCP_IP_ARRAY** out
    <Out> ByRef ElementsRead As UInteger,   ' DWORD* out
    <Out> ByRef ElementsTotal As UInteger   ' DWORD* out
) As UInteger
End Function

' ServerIpAddress : LPCWSTR optional
' ResumeHandle : DWORD* in/out
' PreferredMaximum : DWORD
' EnumInfo : DHCP_IP_ARRAY** out
' ElementsRead : DWORD* out
' ElementsTotal : DWORD* out
Declare PtrSafe Function DhcpEnumSubnets Lib "dhcpsapi" ( _
    ByVal ServerIpAddress As LongPtr, _
    ByRef ResumeHandle As Long, _
    ByVal PreferredMaximum As Long, _
    ByVal EnumInfo As LongPtr, _
    ByRef ElementsRead As Long, _
    ByRef ElementsTotal As Long) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

DhcpEnumSubnets = ctypes.windll.dhcpsapi.DhcpEnumSubnets
DhcpEnumSubnets.restype = wintypes.DWORD
DhcpEnumSubnets.argtypes = [
    wintypes.LPCWSTR,  # ServerIpAddress : LPCWSTR optional
    ctypes.POINTER(wintypes.DWORD),  # ResumeHandle : DWORD* in/out
    wintypes.DWORD,  # PreferredMaximum : DWORD
    ctypes.c_void_p,  # EnumInfo : DHCP_IP_ARRAY** out
    ctypes.POINTER(wintypes.DWORD),  # ElementsRead : DWORD* out
    ctypes.POINTER(wintypes.DWORD),  # ElementsTotal : DWORD* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('DHCPSAPI.dll')
DhcpEnumSubnets = Fiddle::Function.new(
  lib['DhcpEnumSubnets'],
  [
    Fiddle::TYPE_VOIDP,  # ServerIpAddress : LPCWSTR optional
    Fiddle::TYPE_VOIDP,  # ResumeHandle : DWORD* in/out
    -Fiddle::TYPE_INT,  # PreferredMaximum : DWORD
    Fiddle::TYPE_VOIDP,  # EnumInfo : DHCP_IP_ARRAY** out
    Fiddle::TYPE_VOIDP,  # ElementsRead : DWORD* out
    Fiddle::TYPE_VOIDP,  # ElementsTotal : DWORD* out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "dhcpsapi")]
extern "system" {
    fn DhcpEnumSubnets(
        ServerIpAddress: *const u16,  // LPCWSTR optional
        ResumeHandle: *mut u32,  // DWORD* in/out
        PreferredMaximum: u32,  // DWORD
        EnumInfo: *mut *mut DHCP_IP_ARRAY,  // DHCP_IP_ARRAY** out
        ElementsRead: *mut u32,  // DWORD* out
        ElementsTotal: *mut u32  // DWORD* out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("DHCPSAPI.dll")]
public static extern uint DhcpEnumSubnets([MarshalAs(UnmanagedType.LPWStr)] string ServerIpAddress, ref uint ResumeHandle, uint PreferredMaximum, IntPtr EnumInfo, out uint ElementsRead, out uint ElementsTotal);
"@
$api = Add-Type -MemberDefinition $sig -Name 'DHCPSAPI_DhcpEnumSubnets' -Namespace Win32 -PassThru
# $api::DhcpEnumSubnets(ServerIpAddress, ResumeHandle, PreferredMaximum, EnumInfo, ElementsRead, ElementsTotal)

#uselib "DHCPSAPI.dll"
#func global DhcpEnumSubnets "DhcpEnumSubnets" sptr, sptr, sptr, sptr, sptr, sptr
; DhcpEnumSubnets ServerIpAddress, varptr(ResumeHandle), PreferredMaximum, varptr(EnumInfo), varptr(ElementsRead), varptr(ElementsTotal)   ; 戻り値は stat
; ServerIpAddress : LPCWSTR optional -> "sptr"
; ResumeHandle : DWORD* in/out -> "sptr"
; PreferredMaximum : DWORD -> "sptr"
; EnumInfo : DHCP_IP_ARRAY** out -> "sptr"
; ElementsRead : DWORD* out -> "sptr"
; ElementsTotal : DWORD* 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 DhcpEnumSubnets "DhcpEnumSubnets" wstr, var, int, var, var, var
; res = DhcpEnumSubnets(ServerIpAddress, ResumeHandle, PreferredMaximum, EnumInfo, ElementsRead, ElementsTotal)
; ServerIpAddress : LPCWSTR optional -> "wstr"
; ResumeHandle : DWORD* in/out -> "var"
; PreferredMaximum : DWORD -> "int"
; EnumInfo : DHCP_IP_ARRAY** out -> "var"
; ElementsRead : DWORD* out -> "var"
; ElementsTotal : DWORD* 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 DhcpEnumSubnets(LPCWSTR ServerIpAddress, DWORD* ResumeHandle, DWORD PreferredMaximum, DHCP_IP_ARRAY** EnumInfo, DWORD* ElementsRead, DWORD* ElementsTotal)
#uselib "DHCPSAPI.dll"
#cfunc global DhcpEnumSubnets "DhcpEnumSubnets" wstr, var, int, var, var, var
; res = DhcpEnumSubnets(ServerIpAddress, ResumeHandle, PreferredMaximum, EnumInfo, ElementsRead, ElementsTotal)
; ServerIpAddress : LPCWSTR optional -> "wstr"
; ResumeHandle : DWORD* in/out -> "var"
; PreferredMaximum : DWORD -> "int"
; EnumInfo : DHCP_IP_ARRAY** out -> "var"
; ElementsRead : DWORD* out -> "var"
; ElementsTotal : DWORD* 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")
	procDhcpEnumSubnets = dhcpsapi.NewProc("DhcpEnumSubnets")
)

// ServerIpAddress (LPCWSTR optional), ResumeHandle (DWORD* in/out), PreferredMaximum (DWORD), EnumInfo (DHCP_IP_ARRAY** out), ElementsRead (DWORD* out), ElementsTotal (DWORD* out)
r1, _, err := procDhcpEnumSubnets.Call(
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(ServerIpAddress))),
	uintptr(ResumeHandle),
	uintptr(PreferredMaximum),
	uintptr(EnumInfo),
	uintptr(ElementsRead),
	uintptr(ElementsTotal),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function DhcpEnumSubnets(
  ServerIpAddress: PWideChar;   // LPCWSTR optional
  ResumeHandle: Pointer;   // DWORD* in/out
  PreferredMaximum: DWORD;   // DWORD
  EnumInfo: Pointer;   // DHCP_IP_ARRAY** out
  ElementsRead: Pointer;   // DWORD* out
  ElementsTotal: Pointer   // DWORD* out
): DWORD; stdcall;
  external 'DHCPSAPI.dll' name 'DhcpEnumSubnets';

result := DllCall("DHCPSAPI\DhcpEnumSubnets"
    , "WStr", ServerIpAddress   ; LPCWSTR optional
    , "Ptr", ResumeHandle   ; DWORD* in/out
    , "UInt", PreferredMaximum   ; DWORD
    , "Ptr", EnumInfo   ; DHCP_IP_ARRAY** out
    , "Ptr", ElementsRead   ; DWORD* out
    , "Ptr", ElementsTotal   ; DWORD* out
    , "UInt")   ; return: DWORD

●DhcpEnumSubnets(ServerIpAddress, ResumeHandle, PreferredMaximum, EnumInfo, ElementsRead, ElementsTotal) = DLL("DHCPSAPI.dll", "dword DhcpEnumSubnets(char*, void*, dword, void*, void*, void*)")
# 呼び出し: DhcpEnumSubnets(ServerIpAddress, ResumeHandle, PreferredMaximum, EnumInfo, ElementsRead, ElementsTotal)
# ServerIpAddress : LPCWSTR optional -> "char*"
# ResumeHandle : DWORD* in/out -> "void*"
# PreferredMaximum : DWORD -> "dword"
# EnumInfo : DHCP_IP_ARRAY** out -> "void*"
# ElementsRead : DWORD* out -> "void*"
# ElementsTotal : DWORD* 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)。