DhcpV6GetFreeIPAddress

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

DWORD DhcpV6GetFreeIPAddress(
    LPWSTR ServerIpAddress,   // optional
    DHCP_IPV6_ADDRESS ScopeId,
    DHCP_IPV6_ADDRESS StartIP,
    DHCP_IPV6_ADDRESS EndIP,
    DWORD NumFreeAddrReq,
    DHCPV6_IP_ARRAY** IPAddrList
);

<DllImport("DHCPSAPI.dll", ExactSpelling:=True)>
Public Shared Function DhcpV6GetFreeIPAddress(
    <MarshalAs(UnmanagedType.LPWStr)> ServerIpAddress As String,   ' LPWSTR optional
    ScopeId As DHCP_IPV6_ADDRESS,   ' DHCP_IPV6_ADDRESS
    StartIP As DHCP_IPV6_ADDRESS,   ' DHCP_IPV6_ADDRESS
    EndIP As DHCP_IPV6_ADDRESS,   ' DHCP_IPV6_ADDRESS
    NumFreeAddrReq As UInteger,   ' DWORD
    IPAddrList As IntPtr   ' DHCPV6_IP_ARRAY** out
) As UInteger
End Function

' ServerIpAddress : LPWSTR optional
' ScopeId : DHCP_IPV6_ADDRESS
' StartIP : DHCP_IPV6_ADDRESS
' EndIP : DHCP_IPV6_ADDRESS
' NumFreeAddrReq : DWORD
' IPAddrList : DHCPV6_IP_ARRAY** out
Declare PtrSafe Function DhcpV6GetFreeIPAddress Lib "dhcpsapi" ( _
    ByVal ServerIpAddress As LongPtr, _
    ByVal ScopeId As LongPtr, _
    ByVal StartIP As LongPtr, _
    ByVal EndIP As LongPtr, _
    ByVal NumFreeAddrReq As Long, _
    ByVal IPAddrList 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

DhcpV6GetFreeIPAddress = ctypes.windll.dhcpsapi.DhcpV6GetFreeIPAddress
DhcpV6GetFreeIPAddress.restype = wintypes.DWORD
DhcpV6GetFreeIPAddress.argtypes = [
    wintypes.LPCWSTR,  # ServerIpAddress : LPWSTR optional
    DHCP_IPV6_ADDRESS,  # ScopeId : DHCP_IPV6_ADDRESS
    DHCP_IPV6_ADDRESS,  # StartIP : DHCP_IPV6_ADDRESS
    DHCP_IPV6_ADDRESS,  # EndIP : DHCP_IPV6_ADDRESS
    wintypes.DWORD,  # NumFreeAddrReq : DWORD
    ctypes.c_void_p,  # IPAddrList : DHCPV6_IP_ARRAY** out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('DHCPSAPI.dll')
DhcpV6GetFreeIPAddress = Fiddle::Function.new(
  lib['DhcpV6GetFreeIPAddress'],
  [
    Fiddle::TYPE_VOIDP,  # ServerIpAddress : LPWSTR optional
    Fiddle::TYPE_VOIDP,  # ScopeId : DHCP_IPV6_ADDRESS
    Fiddle::TYPE_VOIDP,  # StartIP : DHCP_IPV6_ADDRESS
    Fiddle::TYPE_VOIDP,  # EndIP : DHCP_IPV6_ADDRESS
    -Fiddle::TYPE_INT,  # NumFreeAddrReq : DWORD
    Fiddle::TYPE_VOIDP,  # IPAddrList : DHCPV6_IP_ARRAY** out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "dhcpsapi")]
extern "system" {
    fn DhcpV6GetFreeIPAddress(
        ServerIpAddress: *mut u16,  // LPWSTR optional
        ScopeId: DHCP_IPV6_ADDRESS,  // DHCP_IPV6_ADDRESS
        StartIP: DHCP_IPV6_ADDRESS,  // DHCP_IPV6_ADDRESS
        EndIP: DHCP_IPV6_ADDRESS,  // DHCP_IPV6_ADDRESS
        NumFreeAddrReq: u32,  // DWORD
        IPAddrList: *mut *mut DHCPV6_IP_ARRAY  // DHCPV6_IP_ARRAY** out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("DHCPSAPI.dll")]
public static extern uint DhcpV6GetFreeIPAddress([MarshalAs(UnmanagedType.LPWStr)] string ServerIpAddress, DHCP_IPV6_ADDRESS ScopeId, DHCP_IPV6_ADDRESS StartIP, DHCP_IPV6_ADDRESS EndIP, uint NumFreeAddrReq, IntPtr IPAddrList);
"@
$api = Add-Type -MemberDefinition $sig -Name 'DHCPSAPI_DhcpV6GetFreeIPAddress' -Namespace Win32 -PassThru
# $api::DhcpV6GetFreeIPAddress(ServerIpAddress, ScopeId, StartIP, EndIP, NumFreeAddrReq, IPAddrList)

#uselib "DHCPSAPI.dll"
#func global DhcpV6GetFreeIPAddress "DhcpV6GetFreeIPAddress" sptr, sptr, sptr, sptr, sptr, sptr
; DhcpV6GetFreeIPAddress ServerIpAddress, ScopeId, StartIP, EndIP, NumFreeAddrReq, varptr(IPAddrList)   ; 戻り値は stat
; ServerIpAddress : LPWSTR optional -> "sptr"
; ScopeId : DHCP_IPV6_ADDRESS -> "sptr"
; StartIP : DHCP_IPV6_ADDRESS -> "sptr"
; EndIP : DHCP_IPV6_ADDRESS -> "sptr"
; NumFreeAddrReq : DWORD -> "sptr"
; IPAddrList : DHCPV6_IP_ARRAY** out -> "sptr"
; ※値渡し構造体は直接渡せません。intにパック、または var で構造体変数を渡してください。
; ※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 DhcpV6GetFreeIPAddress "DhcpV6GetFreeIPAddress" wstr, int, int, int, int, var
; res = DhcpV6GetFreeIPAddress(ServerIpAddress, ScopeId, StartIP, EndIP, NumFreeAddrReq, IPAddrList)
; ServerIpAddress : LPWSTR optional -> "wstr"
; ScopeId : DHCP_IPV6_ADDRESS -> "int"
; StartIP : DHCP_IPV6_ADDRESS -> "int"
; EndIP : DHCP_IPV6_ADDRESS -> "int"
; NumFreeAddrReq : DWORD -> "int"
; IPAddrList : DHCPV6_IP_ARRAY** out -> "var"
; ※値渡し構造体は直接渡せません。intにパック、または var で構造体変数を渡してください。
; ※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 DhcpV6GetFreeIPAddress(LPWSTR ServerIpAddress, DHCP_IPV6_ADDRESS ScopeId, DHCP_IPV6_ADDRESS StartIP, DHCP_IPV6_ADDRESS EndIP, DWORD NumFreeAddrReq, DHCPV6_IP_ARRAY** IPAddrList)
#uselib "DHCPSAPI.dll"
#cfunc global DhcpV6GetFreeIPAddress "DhcpV6GetFreeIPAddress" wstr, int, int, int, int, var
; res = DhcpV6GetFreeIPAddress(ServerIpAddress, ScopeId, StartIP, EndIP, NumFreeAddrReq, IPAddrList)
; ServerIpAddress : LPWSTR optional -> "wstr"
; ScopeId : DHCP_IPV6_ADDRESS -> "int"
; StartIP : DHCP_IPV6_ADDRESS -> "int"
; EndIP : DHCP_IPV6_ADDRESS -> "int"
; NumFreeAddrReq : DWORD -> "int"
; IPAddrList : DHCPV6_IP_ARRAY** out -> "var"
; ※値渡し構造体は直接渡せません。intにパック、または var で構造体変数を渡してください。
; ※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")
	procDhcpV6GetFreeIPAddress = dhcpsapi.NewProc("DhcpV6GetFreeIPAddress")
)

// ServerIpAddress (LPWSTR optional), ScopeId (DHCP_IPV6_ADDRESS), StartIP (DHCP_IPV6_ADDRESS), EndIP (DHCP_IPV6_ADDRESS), NumFreeAddrReq (DWORD), IPAddrList (DHCPV6_IP_ARRAY** out)
r1, _, err := procDhcpV6GetFreeIPAddress.Call(
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(ServerIpAddress))),
	uintptr(ScopeId),
	uintptr(StartIP),
	uintptr(EndIP),
	uintptr(NumFreeAddrReq),
	uintptr(IPAddrList),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function DhcpV6GetFreeIPAddress(
  ServerIpAddress: PWideChar;   // LPWSTR optional
  ScopeId: DHCP_IPV6_ADDRESS;   // DHCP_IPV6_ADDRESS
  StartIP: DHCP_IPV6_ADDRESS;   // DHCP_IPV6_ADDRESS
  EndIP: DHCP_IPV6_ADDRESS;   // DHCP_IPV6_ADDRESS
  NumFreeAddrReq: DWORD;   // DWORD
  IPAddrList: Pointer   // DHCPV6_IP_ARRAY** out
): DWORD; stdcall;
  external 'DHCPSAPI.dll' name 'DhcpV6GetFreeIPAddress';

result := DllCall("DHCPSAPI\DhcpV6GetFreeIPAddress"
    , "WStr", ServerIpAddress   ; LPWSTR optional
    , "Ptr", ScopeId   ; DHCP_IPV6_ADDRESS
    , "Ptr", StartIP   ; DHCP_IPV6_ADDRESS
    , "Ptr", EndIP   ; DHCP_IPV6_ADDRESS
    , "UInt", NumFreeAddrReq   ; DWORD
    , "Ptr", IPAddrList   ; DHCPV6_IP_ARRAY** out
    , "UInt")   ; return: DWORD

●DhcpV6GetFreeIPAddress(ServerIpAddress, ScopeId, StartIP, EndIP, NumFreeAddrReq, IPAddrList) = DLL("DHCPSAPI.dll", "dword DhcpV6GetFreeIPAddress(char*, void*, void*, void*, dword, void*)")
# 呼び出し: DhcpV6GetFreeIPAddress(ServerIpAddress, ScopeId, StartIP, EndIP, NumFreeAddrReq, IPAddrList)
# ServerIpAddress : LPWSTR optional -> "char*"
# ScopeId : DHCP_IPV6_ADDRESS -> "void*"
# StartIP : DHCP_IPV6_ADDRESS -> "void*"
# EndIP : DHCP_IPV6_ADDRESS -> "void*"
# NumFreeAddrReq : DWORD -> "dword"
# IPAddrList : DHCPV6_IP_ARRAY** 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)。