DhcpEnumSubnetElementsV6

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

DWORD DhcpEnumSubnetElementsV6(
    LPWSTR ServerIpAddress,   // optional
    DHCP_IPV6_ADDRESS SubnetAddress,
    DHCP_SUBNET_ELEMENT_TYPE_V6 EnumElementType,
    DWORD* ResumeHandle,
    DWORD PreferredMaximum,
    DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** EnumElementInfo,
    DWORD* ElementsRead,
    DWORD* ElementsTotal
);

<DllImport("DHCPSAPI.dll", ExactSpelling:=True)>
Public Shared Function DhcpEnumSubnetElementsV6(
    <MarshalAs(UnmanagedType.LPWStr)> ServerIpAddress As String,   ' LPWSTR optional
    SubnetAddress As DHCP_IPV6_ADDRESS,   ' DHCP_IPV6_ADDRESS
    EnumElementType As Integer,   ' DHCP_SUBNET_ELEMENT_TYPE_V6
    ByRef ResumeHandle As UInteger,   ' DWORD* in/out
    PreferredMaximum As UInteger,   ' DWORD
    EnumElementInfo As IntPtr,   ' DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
    ByRef ElementsRead As UInteger,   ' DWORD* in/out
    ByRef ElementsTotal As UInteger   ' DWORD* in/out
) As UInteger
End Function

' ServerIpAddress : LPWSTR optional
' SubnetAddress : DHCP_IPV6_ADDRESS
' EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6
' ResumeHandle : DWORD* in/out
' PreferredMaximum : DWORD
' EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
' ElementsRead : DWORD* in/out
' ElementsTotal : DWORD* in/out
Declare PtrSafe Function DhcpEnumSubnetElementsV6 Lib "dhcpsapi" ( _
    ByVal ServerIpAddress As LongPtr, _
    ByVal SubnetAddress As LongPtr, _
    ByVal EnumElementType As Long, _
    ByRef ResumeHandle As Long, _
    ByVal PreferredMaximum As Long, _
    ByVal EnumElementInfo 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

DhcpEnumSubnetElementsV6 = ctypes.windll.dhcpsapi.DhcpEnumSubnetElementsV6
DhcpEnumSubnetElementsV6.restype = wintypes.DWORD
DhcpEnumSubnetElementsV6.argtypes = [
    wintypes.LPCWSTR,  # ServerIpAddress : LPWSTR optional
    DHCP_IPV6_ADDRESS,  # SubnetAddress : DHCP_IPV6_ADDRESS
    ctypes.c_int,  # EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6
    ctypes.POINTER(wintypes.DWORD),  # ResumeHandle : DWORD* in/out
    wintypes.DWORD,  # PreferredMaximum : DWORD
    ctypes.c_void_p,  # EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
    ctypes.POINTER(wintypes.DWORD),  # ElementsRead : DWORD* in/out
    ctypes.POINTER(wintypes.DWORD),  # ElementsTotal : DWORD* in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('DHCPSAPI.dll')
DhcpEnumSubnetElementsV6 = Fiddle::Function.new(
  lib['DhcpEnumSubnetElementsV6'],
  [
    Fiddle::TYPE_VOIDP,  # ServerIpAddress : LPWSTR optional
    Fiddle::TYPE_VOIDP,  # SubnetAddress : DHCP_IPV6_ADDRESS
    Fiddle::TYPE_INT,  # EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6
    Fiddle::TYPE_VOIDP,  # ResumeHandle : DWORD* in/out
    -Fiddle::TYPE_INT,  # PreferredMaximum : DWORD
    Fiddle::TYPE_VOIDP,  # EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
    Fiddle::TYPE_VOIDP,  # ElementsRead : DWORD* in/out
    Fiddle::TYPE_VOIDP,  # ElementsTotal : DWORD* in/out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "dhcpsapi")]
extern "system" {
    fn DhcpEnumSubnetElementsV6(
        ServerIpAddress: *mut u16,  // LPWSTR optional
        SubnetAddress: DHCP_IPV6_ADDRESS,  // DHCP_IPV6_ADDRESS
        EnumElementType: i32,  // DHCP_SUBNET_ELEMENT_TYPE_V6
        ResumeHandle: *mut u32,  // DWORD* in/out
        PreferredMaximum: u32,  // DWORD
        EnumElementInfo: *mut *mut DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6,  // DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
        ElementsRead: *mut u32,  // DWORD* in/out
        ElementsTotal: *mut u32  // DWORD* in/out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("DHCPSAPI.dll")]
public static extern uint DhcpEnumSubnetElementsV6([MarshalAs(UnmanagedType.LPWStr)] string ServerIpAddress, DHCP_IPV6_ADDRESS SubnetAddress, int EnumElementType, ref uint ResumeHandle, uint PreferredMaximum, IntPtr EnumElementInfo, ref uint ElementsRead, ref uint ElementsTotal);
"@
$api = Add-Type -MemberDefinition $sig -Name 'DHCPSAPI_DhcpEnumSubnetElementsV6' -Namespace Win32 -PassThru
# $api::DhcpEnumSubnetElementsV6(ServerIpAddress, SubnetAddress, EnumElementType, ResumeHandle, PreferredMaximum, EnumElementInfo, ElementsRead, ElementsTotal)

#uselib "DHCPSAPI.dll"
#func global DhcpEnumSubnetElementsV6 "DhcpEnumSubnetElementsV6" sptr, sptr, sptr, sptr, sptr, sptr, sptr, sptr
; DhcpEnumSubnetElementsV6 ServerIpAddress, SubnetAddress, EnumElementType, varptr(ResumeHandle), PreferredMaximum, varptr(EnumElementInfo), varptr(ElementsRead), varptr(ElementsTotal)   ; 戻り値は stat
; ServerIpAddress : LPWSTR optional -> "sptr"
; SubnetAddress : DHCP_IPV6_ADDRESS -> "sptr"
; EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> "sptr"
; ResumeHandle : DWORD* in/out -> "sptr"
; PreferredMaximum : DWORD -> "sptr"
; EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> "sptr"
; ElementsRead : DWORD* in/out -> "sptr"
; ElementsTotal : DWORD* in/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。

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

var (
	dhcpsapi = windows.NewLazySystemDLL("DHCPSAPI.dll")
	procDhcpEnumSubnetElementsV6 = dhcpsapi.NewProc("DhcpEnumSubnetElementsV6")
)

// ServerIpAddress (LPWSTR optional), SubnetAddress (DHCP_IPV6_ADDRESS), EnumElementType (DHCP_SUBNET_ELEMENT_TYPE_V6), ResumeHandle (DWORD* in/out), PreferredMaximum (DWORD), EnumElementInfo (DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out), ElementsRead (DWORD* in/out), ElementsTotal (DWORD* in/out)
r1, _, err := procDhcpEnumSubnetElementsV6.Call(
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(ServerIpAddress))),
	uintptr(SubnetAddress),
	uintptr(EnumElementType),
	uintptr(ResumeHandle),
	uintptr(PreferredMaximum),
	uintptr(EnumElementInfo),
	uintptr(ElementsRead),
	uintptr(ElementsTotal),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function DhcpEnumSubnetElementsV6(
  ServerIpAddress: PWideChar;   // LPWSTR optional
  SubnetAddress: DHCP_IPV6_ADDRESS;   // DHCP_IPV6_ADDRESS
  EnumElementType: Integer;   // DHCP_SUBNET_ELEMENT_TYPE_V6
  ResumeHandle: Pointer;   // DWORD* in/out
  PreferredMaximum: DWORD;   // DWORD
  EnumElementInfo: Pointer;   // DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
  ElementsRead: Pointer;   // DWORD* in/out
  ElementsTotal: Pointer   // DWORD* in/out
): DWORD; stdcall;
  external 'DHCPSAPI.dll' name 'DhcpEnumSubnetElementsV6';

result := DllCall("DHCPSAPI\DhcpEnumSubnetElementsV6"
    , "WStr", ServerIpAddress   ; LPWSTR optional
    , "Ptr", SubnetAddress   ; DHCP_IPV6_ADDRESS
    , "Int", EnumElementType   ; DHCP_SUBNET_ELEMENT_TYPE_V6
    , "Ptr", ResumeHandle   ; DWORD* in/out
    , "UInt", PreferredMaximum   ; DWORD
    , "Ptr", EnumElementInfo   ; DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
    , "Ptr", ElementsRead   ; DWORD* in/out
    , "Ptr", ElementsTotal   ; DWORD* in/out
    , "UInt")   ; return: DWORD

●DhcpEnumSubnetElementsV6(ServerIpAddress, SubnetAddress, EnumElementType, ResumeHandle, PreferredMaximum, EnumElementInfo, ElementsRead, ElementsTotal) = DLL("DHCPSAPI.dll", "dword DhcpEnumSubnetElementsV6(char*, void*, int, void*, dword, void*, void*, void*)")
# 呼び出し: DhcpEnumSubnetElementsV6(ServerIpAddress, SubnetAddress, EnumElementType, ResumeHandle, PreferredMaximum, EnumElementInfo, ElementsRead, ElementsTotal)
# ServerIpAddress : LPWSTR optional -> "char*"
# SubnetAddress : DHCP_IPV6_ADDRESS -> "void*"
# EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> "int"
# ResumeHandle : DWORD* in/out -> "void*"
# PreferredMaximum : DWORD -> "dword"
# EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> "void*"
# ElementsRead : DWORD* in/out -> "void*"
# ElementsTotal : DWORD* 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)。

const std = @import("std");

extern "dhcpsapi" fn DhcpEnumSubnetElementsV6(
    ServerIpAddress: [*c]const u16, // LPWSTR optional
    SubnetAddress: DHCP_IPV6_ADDRESS, // DHCP_IPV6_ADDRESS
    EnumElementType: i32, // DHCP_SUBNET_ELEMENT_TYPE_V6
    ResumeHandle: [*c]u32, // DWORD* in/out
    PreferredMaximum: u32, // DWORD
    EnumElementInfo: [*c][*c]DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6, // DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
    ElementsRead: [*c]u32, // DWORD* in/out
    ElementsTotal: [*c]u32 // DWORD* in/out
) callconv(std.os.windows.WINAPI) u32;

proc DhcpEnumSubnetElementsV6(
    ServerIpAddress: WideCString,  # LPWSTR optional
    SubnetAddress: DHCP_IPV6_ADDRESS,  # DHCP_IPV6_ADDRESS
    EnumElementType: int32,  # DHCP_SUBNET_ELEMENT_TYPE_V6
    ResumeHandle: ptr uint32,  # DWORD* in/out
    PreferredMaximum: uint32,  # DWORD
    EnumElementInfo: ptr DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6,  # DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
    ElementsRead: ptr uint32,  # DWORD* in/out
    ElementsTotal: ptr uint32  # DWORD* in/out
): uint32 {.importc: "DhcpEnumSubnetElementsV6", stdcall, dynlib: "DHCPSAPI.dll".}

pragma(lib, "dhcpsapi");
extern(Windows)
uint DhcpEnumSubnetElementsV6(
    const(wchar)* ServerIpAddress,   // LPWSTR optional
    DHCP_IPV6_ADDRESS SubnetAddress,   // DHCP_IPV6_ADDRESS
    int EnumElementType,   // DHCP_SUBNET_ELEMENT_TYPE_V6
    uint* ResumeHandle,   // DWORD* in/out
    uint PreferredMaximum,   // DWORD
    DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** EnumElementInfo,   // DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
    uint* ElementsRead,   // DWORD* in/out
    uint* ElementsTotal   // DWORD* in/out
);

ccall((:DhcpEnumSubnetElementsV6, "DHCPSAPI.dll"), stdcall, UInt32,
      (Cwstring, DHCP_IPV6_ADDRESS, Int32, Ptr{UInt32}, UInt32, Ptr{DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6}, Ptr{UInt32}, Ptr{UInt32}),
      ServerIpAddress, SubnetAddress, EnumElementType, ResumeHandle, PreferredMaximum, EnumElementInfo, ElementsRead, ElementsTotal)
# ServerIpAddress : LPWSTR optional -> Cwstring
# SubnetAddress : DHCP_IPV6_ADDRESS -> DHCP_IPV6_ADDRESS
# EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> Int32
# ResumeHandle : DWORD* in/out -> Ptr{UInt32}
# PreferredMaximum : DWORD -> UInt32
# EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> Ptr{DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6}
# ElementsRead : DWORD* in/out -> Ptr{UInt32}
# ElementsTotal : DWORD* in/out -> Ptr{UInt32}
# stdcall は 32bit のみ意味を持つ(x64 では無視)。

local ffi = require("ffi")
ffi.cdef[[
uint32_t DhcpEnumSubnetElementsV6(
    const uint16_t* ServerIpAddress,
    DHCP_IPV6_ADDRESS SubnetAddress,
    int32_t EnumElementType,
    uint32_t* ResumeHandle,
    uint32_t PreferredMaximum,
    void* EnumElementInfo,
    uint32_t* ElementsRead,
    uint32_t* ElementsTotal);
]]
local dhcpsapi = ffi.load("dhcpsapi")
-- dhcpsapi.DhcpEnumSubnetElementsV6(ServerIpAddress, SubnetAddress, EnumElementType, ResumeHandle, PreferredMaximum, EnumElementInfo, ElementsRead, ElementsTotal)
-- ServerIpAddress : LPWSTR optional
-- SubnetAddress : DHCP_IPV6_ADDRESS
-- EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6
-- ResumeHandle : DWORD* in/out
-- PreferredMaximum : DWORD
-- EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
-- ElementsRead : DWORD* in/out
-- ElementsTotal : DWORD* in/out
-- 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。

const koffi = require('koffi');
const lib = koffi.load('DHCPSAPI.dll');
const DhcpEnumSubnetElementsV6 = lib.func('__stdcall', 'DhcpEnumSubnetElementsV6', 'uint32_t', ['str16', 'DHCP_IPV6_ADDRESS', 'int32_t', 'uint32_t *', 'uint32_t', 'void *', 'uint32_t *', 'uint32_t *']);
// DhcpEnumSubnetElementsV6(ServerIpAddress, SubnetAddress, EnumElementType, ResumeHandle, PreferredMaximum, EnumElementInfo, ElementsRead, ElementsTotal)
// ServerIpAddress : LPWSTR optional -> 'str16'
// SubnetAddress : DHCP_IPV6_ADDRESS -> 'DHCP_IPV6_ADDRESS'
// EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> 'int32_t'
// ResumeHandle : DWORD* in/out -> 'uint32_t *'
// PreferredMaximum : DWORD -> 'uint32_t'
// EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> 'void *'
// ElementsRead : DWORD* in/out -> 'uint32_t *'
// ElementsTotal : DWORD* in/out -> 'uint32_t *'
// 出力ポインタは koffi.out(...) で包む。構造体は koffi.struct で定義。

const lib = Deno.dlopen("DHCPSAPI.dll", {
  DhcpEnumSubnetElementsV6: { parameters: ["buffer", "buffer", "i32", "pointer", "u32", "pointer", "pointer", "pointer"], result: "u32" },
});
// lib.symbols.DhcpEnumSubnetElementsV6(ServerIpAddress, SubnetAddress, EnumElementType, ResumeHandle, PreferredMaximum, EnumElementInfo, ElementsRead, ElementsTotal)
// ServerIpAddress : LPWSTR optional -> "buffer"
// SubnetAddress : DHCP_IPV6_ADDRESS -> "buffer"
// EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> "i32"
// ResumeHandle : DWORD* in/out -> "pointer"
// PreferredMaximum : DWORD -> "u32"
// EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> "pointer"
// ElementsRead : DWORD* in/out -> "pointer"
// ElementsTotal : DWORD* in/out -> "pointer"
// 文字列引数は "buffer"(NUL 終端のバイト列を Uint8Array で渡す)。
// 値渡し構造体は { struct: [ ...field types... ] } を使用。

<?php
$ffi = FFI::cdef(<<<C
uint32_t DhcpEnumSubnetElementsV6(
    const uint16_t* ServerIpAddress,
    DHCP_IPV6_ADDRESS SubnetAddress,
    int32_t EnumElementType,
    uint32_t* ResumeHandle,
    uint32_t PreferredMaximum,
    void* EnumElementInfo,
    uint32_t* ElementsRead,
    uint32_t* ElementsTotal);
C, "DHCPSAPI.dll");
// $ffi->DhcpEnumSubnetElementsV6(ServerIpAddress, SubnetAddress, EnumElementType, ResumeHandle, PreferredMaximum, EnumElementInfo, ElementsRead, ElementsTotal);
// ServerIpAddress : LPWSTR optional
// SubnetAddress : DHCP_IPV6_ADDRESS
// EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6
// ResumeHandle : DWORD* in/out
// PreferredMaximum : DWORD
// EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
// ElementsRead : DWORD* in/out
// ElementsTotal : DWORD* in/out
// 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。
// WINAPI(stdcall): x64 では呼出規約が統一されるため問題なし。x86 では __stdcall 対応のラッパが必要な場合あり。

import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.W32APIOptions;

public interface Dhcpsapi extends StdCallLibrary {
    Dhcpsapi INSTANCE = Native.load("dhcpsapi", Dhcpsapi.class);
    int DhcpEnumSubnetElementsV6(
        WString ServerIpAddress,   // LPWSTR optional
        DHCP_IPV6_ADDRESS /* extends Structure (by value) */ SubnetAddress,   // DHCP_IPV6_ADDRESS
        int EnumElementType,   // DHCP_SUBNET_ELEMENT_TYPE_V6
        IntByReference ResumeHandle,   // DWORD* in/out
        int PreferredMaximum,   // DWORD
        Pointer EnumElementInfo,   // DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
        IntByReference ElementsRead,   // DWORD* in/out
        IntByReference ElementsTotal   // DWORD* in/out
    );
}

@[Link("dhcpsapi")]
lib LibDHCPSAPI
  fun DhcpEnumSubnetElementsV6 = DhcpEnumSubnetElementsV6(
    ServerIpAddress : UInt16*,   # LPWSTR optional
    SubnetAddress : DHCP_IPV6_ADDRESS,   # DHCP_IPV6_ADDRESS
    EnumElementType : Int32,   # DHCP_SUBNET_ELEMENT_TYPE_V6
    ResumeHandle : UInt32*,   # DWORD* in/out
    PreferredMaximum : UInt32,   # DWORD
    EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6**,   # DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
    ElementsRead : UInt32*,   # DWORD* in/out
    ElementsTotal : UInt32*   # DWORD* in/out
  ) : UInt32
end
# 構造体/GUID/enum は lib 内に対応する型定義が必要。
# 呼出規約: x64 は規約統一のため OK。x86(32bit)は WINAPI=stdcall だが Crystal の fun に stdcall 付与構文がなく非対応。

import 'dart:ffi';
import 'package:ffi/ffi.dart';

typedef DhcpEnumSubnetElementsV6Native = Uint32 Function(Pointer<Utf16>, DHCP_IPV6_ADDRESS, Int32, Pointer<Uint32>, Uint32, Pointer<Void>, Pointer<Uint32>, Pointer<Uint32>);
typedef DhcpEnumSubnetElementsV6Dart = int Function(Pointer<Utf16>, int, int, Pointer<Uint32>, int, Pointer<Void>, Pointer<Uint32>, Pointer<Uint32>);
final DhcpEnumSubnetElementsV6 = DynamicLibrary.open('DHCPSAPI.dll')
    .lookupFunction<DhcpEnumSubnetElementsV6Native, DhcpEnumSubnetElementsV6Dart>('DhcpEnumSubnetElementsV6');
// ServerIpAddress : LPWSTR optional -> Pointer<Utf16>
// SubnetAddress : DHCP_IPV6_ADDRESS -> DHCP_IPV6_ADDRESS
// EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> Int32
// ResumeHandle : DWORD* in/out -> Pointer<Uint32>
// PreferredMaximum : DWORD -> Uint32
// EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> Pointer<Void>
// ElementsRead : DWORD* in/out -> Pointer<Uint32>
// ElementsTotal : DWORD* in/out -> Pointer<Uint32>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
function DhcpEnumSubnetElementsV6(
  ServerIpAddress: PWideChar;   // LPWSTR optional
  SubnetAddress: DHCP_IPV6_ADDRESS;   // DHCP_IPV6_ADDRESS
  EnumElementType: Integer;   // DHCP_SUBNET_ELEMENT_TYPE_V6
  ResumeHandle: Pointer;   // DWORD* in/out
  PreferredMaximum: DWORD;   // DWORD
  EnumElementInfo: Pointer;   // DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
  ElementsRead: Pointer;   // DWORD* in/out
  ElementsTotal: Pointer   // DWORD* in/out
): DWORD; stdcall;
  external 'DHCPSAPI.dll' name 'DhcpEnumSubnetElementsV6';

import Foreign
import Foreign.C.Types
import Foreign.C.String

foreign import stdcall safe "DhcpEnumSubnetElementsV6"
  c_DhcpEnumSubnetElementsV6 :: CWString -> DHCP_IPV6_ADDRESS -> Int32 -> Ptr Word32 -> Word32 -> Ptr () -> Ptr Word32 -> Ptr Word32 -> IO Word32
-- ServerIpAddress : LPWSTR optional -> CWString
-- SubnetAddress : DHCP_IPV6_ADDRESS -> DHCP_IPV6_ADDRESS
-- EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> Int32
-- ResumeHandle : DWORD* in/out -> Ptr Word32
-- PreferredMaximum : DWORD -> Word32
-- EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> Ptr ()
-- ElementsRead : DWORD* in/out -> Ptr Word32
-- ElementsTotal : DWORD* in/out -> Ptr Word32
-- 要 GHC(Windows)。stdcall は x64 では ccall として扱われる。ブロックする API は safe 呼び出し推奨。
-- ※値渡し構造体は GHC FFI で直接渡せません。Ptr で渡すラッパ(C側)経由にしてください。

open Ctypes
open Foreign

let dhcpenumsubnetelementsv6 =
  foreign "DhcpEnumSubnetElementsV6"
    ((ptr uint16_t) @-> DHCP_IPV6_ADDRESS @-> int32_t @-> (ptr uint32_t) @-> uint32_t @-> (ptr void) @-> (ptr uint32_t) @-> (ptr uint32_t) @-> returning uint32_t)
(* ServerIpAddress : LPWSTR optional -> (ptr uint16_t) *)
(* SubnetAddress : DHCP_IPV6_ADDRESS -> DHCP_IPV6_ADDRESS *)
(* EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> int32_t *)
(* ResumeHandle : DWORD* in/out -> (ptr uint32_t) *)
(* PreferredMaximum : DWORD -> uint32_t *)
(* EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> (ptr void) *)
(* ElementsRead : DWORD* in/out -> (ptr uint32_t) *)
(* ElementsTotal : DWORD* in/out -> (ptr uint32_t) *)
(* foreign は cdecl 前提。x64 Windows では WINAPI と一致。構造体は ctypes structure を定義のこと。 *)

(cffi:define-foreign-library dhcpsapi (t "DHCPSAPI.dll"))
(cffi:use-foreign-library dhcpsapi)

(cffi:defcfun ("DhcpEnumSubnetElementsV6" dhcp-enum-subnet-elements-v6 :convention :stdcall) :uint32
  (server-ip-address (:string :encoding :utf-16le))   ; LPWSTR optional
  (subnet-address (:struct dhcp-ipv6-address))   ; DHCP_IPV6_ADDRESS
  (enum-element-type :int32)   ; DHCP_SUBNET_ELEMENT_TYPE_V6
  (resume-handle :pointer)   ; DWORD* in/out
  (preferred-maximum :uint32)   ; DWORD
  (enum-element-info :pointer)   ; DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out
  (elements-read :pointer)   ; DWORD* in/out
  (elements-total :pointer))   ; DWORD* in/out
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。

use Win32::API;
my $DhcpEnumSubnetElementsV6 = Win32::API::More->new('DHCPSAPI',
    'DWORD DhcpEnumSubnetElementsV6(LPCWSTR ServerIpAddress, LPVOID SubnetAddress, int EnumElementType, LPVOID ResumeHandle, DWORD PreferredMaximum, LPVOID EnumElementInfo, LPVOID ElementsRead, LPVOID ElementsTotal)');
# my $ret = $DhcpEnumSubnetElementsV6->Call($ServerIpAddress, $SubnetAddress, $EnumElementType, $ResumeHandle, $PreferredMaximum, $EnumElementInfo, $ElementsRead, $ElementsTotal);
# ServerIpAddress : LPWSTR optional -> LPCWSTR
# SubnetAddress : DHCP_IPV6_ADDRESS -> LPVOID
# EnumElementType : DHCP_SUBNET_ELEMENT_TYPE_V6 -> int
# ResumeHandle : DWORD* in/out -> LPVOID
# PreferredMaximum : DWORD -> DWORD
# EnumElementInfo : DHCP_SUBNET_ELEMENT_INFO_ARRAY_V6** in/out -> LPVOID
# ElementsRead : DWORD* in/out -> LPVOID
# ElementsTotal : DWORD* in/out -> LPVOID
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。