getsockopt

// WS2_32.dll
#include <windows.h>

INT getsockopt(
    SOCKET s,
    INT level,
    INT optname,
    LPSTR optval,
    INT* optlen
);

<DllImport("WS2_32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function getsockopt(
    s As UIntPtr,   ' SOCKET
    level As Integer,   ' INT
    optname As Integer,   ' INT
    <MarshalAs(UnmanagedType.LPStr)> optval As System.Text.StringBuilder,   ' LPSTR out
    ByRef optlen As Integer   ' INT* in/out
) As Integer
End Function

' s : SOCKET
' level : INT
' optname : INT
' optval : LPSTR out
' optlen : INT* in/out
Declare PtrSafe Function getsockopt Lib "ws2_32" ( _
    ByVal s As LongPtr, _
    ByVal level As Long, _
    ByVal optname As Long, _
    ByVal optval As String, _
    ByRef optlen 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

getsockopt = ctypes.windll.ws2_32.getsockopt
getsockopt.restype = ctypes.c_int
getsockopt.argtypes = [
    ctypes.c_size_t,  # s : SOCKET
    ctypes.c_int,  # level : INT
    ctypes.c_int,  # optname : INT
    wintypes.LPSTR,  # optval : LPSTR out
    ctypes.POINTER(ctypes.c_int),  # optlen : INT* in/out
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('WS2_32.dll')
getsockopt = Fiddle::Function.new(
  lib['getsockopt'],
  [
    Fiddle::TYPE_UINTPTR_T,  # s : SOCKET
    Fiddle::TYPE_INT,  # level : INT
    Fiddle::TYPE_INT,  # optname : INT
    Fiddle::TYPE_VOIDP,  # optval : LPSTR out
    Fiddle::TYPE_VOIDP,  # optlen : INT* in/out
  ],
  Fiddle::TYPE_INT)

#[link(name = "ws2_32")]
extern "system" {
    fn getsockopt(
        s: usize,  // SOCKET
        level: i32,  // INT
        optname: i32,  // INT
        optval: *mut u8,  // LPSTR out
        optlen: *mut i32  // INT* in/out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("WS2_32.dll", SetLastError = true)]
public static extern int getsockopt(UIntPtr s, int level, int optname, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder optval, ref int optlen);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WS2_32_getsockopt' -Namespace Win32 -PassThru
# $api::getsockopt(s, level, optname, optval, optlen)

#uselib "WS2_32.dll"
#func global getsockopt "getsockopt" sptr, sptr, sptr, sptr, sptr
; getsockopt s, level, optname, varptr(optval), varptr(optlen)   ; 戻り値は stat
; s : SOCKET -> "sptr"
; level : INT -> "sptr"
; optname : INT -> "sptr"
; optval : LPSTR out -> "sptr"
; optlen : INT* 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 "WS2_32.dll"
#cfunc global getsockopt "getsockopt" sptr, int, int, var, var
; res = getsockopt(s, level, optname, optval, optlen)
; s : SOCKET -> "sptr"
; level : INT -> "int"
; optname : INT -> "int"
; optval : LPSTR out -> "var"
; optlen : INT* 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。

; INT getsockopt(SOCKET s, INT level, INT optname, LPSTR optval, INT* optlen)
#uselib "WS2_32.dll"
#cfunc global getsockopt "getsockopt" intptr, int, int, var, var
; res = getsockopt(s, level, optname, optval, optlen)
; s : SOCKET -> "intptr"
; level : INT -> "int"
; optname : INT -> "int"
; optval : LPSTR out -> "var"
; optlen : INT* 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 (
	ws2_32 = windows.NewLazySystemDLL("WS2_32.dll")
	procgetsockopt = ws2_32.NewProc("getsockopt")
)

// s (SOCKET), level (INT), optname (INT), optval (LPSTR out), optlen (INT* in/out)
r1, _, err := procgetsockopt.Call(
	uintptr(s),
	uintptr(level),
	uintptr(optname),
	uintptr(optval),
	uintptr(optlen),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function getsockopt(
  s: NativeUInt;   // SOCKET
  level: Integer;   // INT
  optname: Integer;   // INT
  optval: PAnsiChar;   // LPSTR out
  optlen: Pointer   // INT* in/out
): Integer; stdcall;
  external 'WS2_32.dll' name 'getsockopt';

result := DllCall("WS2_32\getsockopt"
    , "UPtr", s   ; SOCKET
    , "Int", level   ; INT
    , "Int", optname   ; INT
    , "Ptr", optval   ; LPSTR out
    , "Ptr", optlen   ; INT* in/out
    , "Int")   ; return: INT

●getsockopt(s, level, optname, optval, optlen) = DLL("WS2_32.dll", "int getsockopt(int, int, int, char*, void*)")
# 呼び出し: getsockopt(s, level, optname, optval, optlen)
# s : SOCKET -> "int"
# level : INT -> "int"
# optname : INT -> "int"
# optval : LPSTR out -> "char*"
# optlen : INT* 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)。