DhcpGetSubnetInfo

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

DWORD DhcpGetSubnetInfo(
    LPCWSTR ServerIpAddress,   // optional
    DWORD SubnetAddress,
    DHCP_SUBNET_INFO** SubnetInfo
);

<DllImport("DHCPSAPI.dll", ExactSpelling:=True)>
Public Shared Function DhcpGetSubnetInfo(
    <MarshalAs(UnmanagedType.LPWStr)> ServerIpAddress As String,   ' LPCWSTR optional
    SubnetAddress As UInteger,   ' DWORD
    SubnetInfo As IntPtr   ' DHCP_SUBNET_INFO** in/out
) As UInteger
End Function

' ServerIpAddress : LPCWSTR optional
' SubnetAddress : DWORD
' SubnetInfo : DHCP_SUBNET_INFO** in/out
Declare PtrSafe Function DhcpGetSubnetInfo Lib "dhcpsapi" ( _
    ByVal ServerIpAddress As LongPtr, _
    ByVal SubnetAddress As Long, _
    ByVal SubnetInfo 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

DhcpGetSubnetInfo = ctypes.windll.dhcpsapi.DhcpGetSubnetInfo
DhcpGetSubnetInfo.restype = wintypes.DWORD
DhcpGetSubnetInfo.argtypes = [
    wintypes.LPCWSTR,  # ServerIpAddress : LPCWSTR optional
    wintypes.DWORD,  # SubnetAddress : DWORD
    ctypes.c_void_p,  # SubnetInfo : DHCP_SUBNET_INFO** in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('DHCPSAPI.dll')
DhcpGetSubnetInfo = Fiddle::Function.new(
  lib['DhcpGetSubnetInfo'],
  [
    Fiddle::TYPE_VOIDP,  # ServerIpAddress : LPCWSTR optional
    -Fiddle::TYPE_INT,  # SubnetAddress : DWORD
    Fiddle::TYPE_VOIDP,  # SubnetInfo : DHCP_SUBNET_INFO** in/out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "dhcpsapi")]
extern "system" {
    fn DhcpGetSubnetInfo(
        ServerIpAddress: *const u16,  // LPCWSTR optional
        SubnetAddress: u32,  // DWORD
        SubnetInfo: *mut *mut DHCP_SUBNET_INFO  // DHCP_SUBNET_INFO** in/out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

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

#uselib "DHCPSAPI.dll"
#func global DhcpGetSubnetInfo "DhcpGetSubnetInfo" sptr, sptr, sptr
; DhcpGetSubnetInfo ServerIpAddress, SubnetAddress, varptr(SubnetInfo)   ; 戻り値は stat
; ServerIpAddress : LPCWSTR optional -> "sptr"
; SubnetAddress : DWORD -> "sptr"
; SubnetInfo : DHCP_SUBNET_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 DhcpGetSubnetInfo "DhcpGetSubnetInfo" wstr, int, var
; res = DhcpGetSubnetInfo(ServerIpAddress, SubnetAddress, SubnetInfo)
; ServerIpAddress : LPCWSTR optional -> "wstr"
; SubnetAddress : DWORD -> "int"
; SubnetInfo : DHCP_SUBNET_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 DhcpGetSubnetInfo(LPCWSTR ServerIpAddress, DWORD SubnetAddress, DHCP_SUBNET_INFO** SubnetInfo)
#uselib "DHCPSAPI.dll"
#cfunc global DhcpGetSubnetInfo "DhcpGetSubnetInfo" wstr, int, var
; res = DhcpGetSubnetInfo(ServerIpAddress, SubnetAddress, SubnetInfo)
; ServerIpAddress : LPCWSTR optional -> "wstr"
; SubnetAddress : DWORD -> "int"
; SubnetInfo : DHCP_SUBNET_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")
	procDhcpGetSubnetInfo = dhcpsapi.NewProc("DhcpGetSubnetInfo")
)

// ServerIpAddress (LPCWSTR optional), SubnetAddress (DWORD), SubnetInfo (DHCP_SUBNET_INFO** in/out)
r1, _, err := procDhcpGetSubnetInfo.Call(
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(ServerIpAddress))),
	uintptr(SubnetAddress),
	uintptr(SubnetInfo),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function DhcpGetSubnetInfo(
  ServerIpAddress: PWideChar;   // LPCWSTR optional
  SubnetAddress: DWORD;   // DWORD
  SubnetInfo: Pointer   // DHCP_SUBNET_INFO** in/out
): DWORD; stdcall;
  external 'DHCPSAPI.dll' name 'DhcpGetSubnetInfo';

result := DllCall("DHCPSAPI\DhcpGetSubnetInfo"
    , "WStr", ServerIpAddress   ; LPCWSTR optional
    , "UInt", SubnetAddress   ; DWORD
    , "Ptr", SubnetInfo   ; DHCP_SUBNET_INFO** in/out
    , "UInt")   ; return: DWORD

●DhcpGetSubnetInfo(ServerIpAddress, SubnetAddress, SubnetInfo) = DLL("DHCPSAPI.dll", "dword DhcpGetSubnetInfo(char*, dword, void*)")
# 呼び出し: DhcpGetSubnetInfo(ServerIpAddress, SubnetAddress, SubnetInfo)
# ServerIpAddress : LPCWSTR optional -> "char*"
# SubnetAddress : DWORD -> "dword"
# SubnetInfo : DHCP_SUBNET_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)。