WSASendTo

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

INT WSASendTo(
    SOCKET s,
    WSABUF* lpBuffers,
    DWORD dwBufferCount,
    DWORD* lpNumberOfBytesSent,   // optional
    DWORD dwFlags,
    const SOCKADDR* lpTo,   // optional
    INT iTolen,
    OVERLAPPED* lpOverlapped,   // optional
    LPWSAOVERLAPPED_COMPLETION_ROUTINE lpCompletionRoutine   // optional
);

<DllImport("WS2_32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function WSASendTo(
    s As UIntPtr,   ' SOCKET
    lpBuffers As IntPtr,   ' WSABUF*
    dwBufferCount As UInteger,   ' DWORD
    lpNumberOfBytesSent As IntPtr,   ' DWORD* optional, out
    dwFlags As UInteger,   ' DWORD
    lpTo As IntPtr,   ' SOCKADDR* optional
    iTolen As Integer,   ' INT
    lpOverlapped As IntPtr,   ' OVERLAPPED* optional, in/out
    lpCompletionRoutine As IntPtr   ' LPWSAOVERLAPPED_COMPLETION_ROUTINE optional
) As Integer
End Function

' s : SOCKET
' lpBuffers : WSABUF*
' dwBufferCount : DWORD
' lpNumberOfBytesSent : DWORD* optional, out
' dwFlags : DWORD
' lpTo : SOCKADDR* optional
' iTolen : INT
' lpOverlapped : OVERLAPPED* optional, in/out
' lpCompletionRoutine : LPWSAOVERLAPPED_COMPLETION_ROUTINE optional
Declare PtrSafe Function WSASendTo Lib "ws2_32" ( _
    ByVal s As LongPtr, _
    ByVal lpBuffers As LongPtr, _
    ByVal dwBufferCount As Long, _
    ByVal lpNumberOfBytesSent As LongPtr, _
    ByVal dwFlags As Long, _
    ByVal lpTo As LongPtr, _
    ByVal iTolen As Long, _
    ByVal lpOverlapped As LongPtr, _
    ByVal lpCompletionRoutine 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

WSASendTo = ctypes.windll.ws2_32.WSASendTo
WSASendTo.restype = ctypes.c_int
WSASendTo.argtypes = [
    ctypes.c_size_t,  # s : SOCKET
    ctypes.c_void_p,  # lpBuffers : WSABUF*
    wintypes.DWORD,  # dwBufferCount : DWORD
    ctypes.POINTER(wintypes.DWORD),  # lpNumberOfBytesSent : DWORD* optional, out
    wintypes.DWORD,  # dwFlags : DWORD
    ctypes.c_void_p,  # lpTo : SOCKADDR* optional
    ctypes.c_int,  # iTolen : INT
    ctypes.c_void_p,  # lpOverlapped : OVERLAPPED* optional, in/out
    ctypes.c_void_p,  # lpCompletionRoutine : LPWSAOVERLAPPED_COMPLETION_ROUTINE optional
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('WS2_32.dll')
WSASendTo = Fiddle::Function.new(
  lib['WSASendTo'],
  [
    Fiddle::TYPE_UINTPTR_T,  # s : SOCKET
    Fiddle::TYPE_VOIDP,  # lpBuffers : WSABUF*
    -Fiddle::TYPE_INT,  # dwBufferCount : DWORD
    Fiddle::TYPE_VOIDP,  # lpNumberOfBytesSent : DWORD* optional, out
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_VOIDP,  # lpTo : SOCKADDR* optional
    Fiddle::TYPE_INT,  # iTolen : INT
    Fiddle::TYPE_VOIDP,  # lpOverlapped : OVERLAPPED* optional, in/out
    Fiddle::TYPE_VOIDP,  # lpCompletionRoutine : LPWSAOVERLAPPED_COMPLETION_ROUTINE optional
  ],
  Fiddle::TYPE_INT)

#[link(name = "ws2_32")]
extern "system" {
    fn WSASendTo(
        s: usize,  // SOCKET
        lpBuffers: *mut WSABUF,  // WSABUF*
        dwBufferCount: u32,  // DWORD
        lpNumberOfBytesSent: *mut u32,  // DWORD* optional, out
        dwFlags: u32,  // DWORD
        lpTo: *const SOCKADDR,  // SOCKADDR* optional
        iTolen: i32,  // INT
        lpOverlapped: *mut OVERLAPPED,  // OVERLAPPED* optional, in/out
        lpCompletionRoutine: *const core::ffi::c_void  // LPWSAOVERLAPPED_COMPLETION_ROUTINE optional
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("WS2_32.dll", SetLastError = true)]
public static extern int WSASendTo(UIntPtr s, IntPtr lpBuffers, uint dwBufferCount, IntPtr lpNumberOfBytesSent, uint dwFlags, IntPtr lpTo, int iTolen, IntPtr lpOverlapped, IntPtr lpCompletionRoutine);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WS2_32_WSASendTo' -Namespace Win32 -PassThru
# $api::WSASendTo(s, lpBuffers, dwBufferCount, lpNumberOfBytesSent, dwFlags, lpTo, iTolen, lpOverlapped, lpCompletionRoutine)

#uselib "WS2_32.dll"
#func global WSASendTo "WSASendTo" sptr, sptr, sptr, sptr, sptr, sptr, sptr, sptr, sptr
; WSASendTo s, varptr(lpBuffers), dwBufferCount, varptr(lpNumberOfBytesSent), dwFlags, varptr(lpTo), iTolen, varptr(lpOverlapped), lpCompletionRoutine   ; 戻り値は stat
; s : SOCKET -> "sptr"
; lpBuffers : WSABUF* -> "sptr"
; dwBufferCount : DWORD -> "sptr"
; lpNumberOfBytesSent : DWORD* optional, out -> "sptr"
; dwFlags : DWORD -> "sptr"
; lpTo : SOCKADDR* optional -> "sptr"
; iTolen : INT -> "sptr"
; lpOverlapped : OVERLAPPED* optional, in/out -> "sptr"
; lpCompletionRoutine : LPWSAOVERLAPPED_COMPLETION_ROUTINE optional -> "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 WSASendTo "WSASendTo" sptr, var, int, var, int, var, int, var, sptr
; res = WSASendTo(s, lpBuffers, dwBufferCount, lpNumberOfBytesSent, dwFlags, lpTo, iTolen, lpOverlapped, lpCompletionRoutine)
; s : SOCKET -> "sptr"
; lpBuffers : WSABUF* -> "var"
; dwBufferCount : DWORD -> "int"
; lpNumberOfBytesSent : DWORD* optional, out -> "var"
; dwFlags : DWORD -> "int"
; lpTo : SOCKADDR* optional -> "var"
; iTolen : INT -> "int"
; lpOverlapped : OVERLAPPED* optional, in/out -> "var"
; lpCompletionRoutine : LPWSAOVERLAPPED_COMPLETION_ROUTINE optional -> "sptr"
; ※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 WSASendTo(SOCKET s, WSABUF* lpBuffers, DWORD dwBufferCount, DWORD* lpNumberOfBytesSent, DWORD dwFlags, SOCKADDR* lpTo, INT iTolen, OVERLAPPED* lpOverlapped, LPWSAOVERLAPPED_COMPLETION_ROUTINE lpCompletionRoutine)
#uselib "WS2_32.dll"
#cfunc global WSASendTo "WSASendTo" intptr, var, int, var, int, var, int, var, intptr
; res = WSASendTo(s, lpBuffers, dwBufferCount, lpNumberOfBytesSent, dwFlags, lpTo, iTolen, lpOverlapped, lpCompletionRoutine)
; s : SOCKET -> "intptr"
; lpBuffers : WSABUF* -> "var"
; dwBufferCount : DWORD -> "int"
; lpNumberOfBytesSent : DWORD* optional, out -> "var"
; dwFlags : DWORD -> "int"
; lpTo : SOCKADDR* optional -> "var"
; iTolen : INT -> "int"
; lpOverlapped : OVERLAPPED* optional, in/out -> "var"
; lpCompletionRoutine : LPWSAOVERLAPPED_COMPLETION_ROUTINE optional -> "intptr"
; ※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")
	procWSASendTo = ws2_32.NewProc("WSASendTo")
)

// s (SOCKET), lpBuffers (WSABUF*), dwBufferCount (DWORD), lpNumberOfBytesSent (DWORD* optional, out), dwFlags (DWORD), lpTo (SOCKADDR* optional), iTolen (INT), lpOverlapped (OVERLAPPED* optional, in/out), lpCompletionRoutine (LPWSAOVERLAPPED_COMPLETION_ROUTINE optional)
r1, _, err := procWSASendTo.Call(
	uintptr(s),
	uintptr(lpBuffers),
	uintptr(dwBufferCount),
	uintptr(lpNumberOfBytesSent),
	uintptr(dwFlags),
	uintptr(lpTo),
	uintptr(iTolen),
	uintptr(lpOverlapped),
	uintptr(lpCompletionRoutine),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function WSASendTo(
  s: NativeUInt;   // SOCKET
  lpBuffers: Pointer;   // WSABUF*
  dwBufferCount: DWORD;   // DWORD
  lpNumberOfBytesSent: Pointer;   // DWORD* optional, out
  dwFlags: DWORD;   // DWORD
  lpTo: Pointer;   // SOCKADDR* optional
  iTolen: Integer;   // INT
  lpOverlapped: Pointer;   // OVERLAPPED* optional, in/out
  lpCompletionRoutine: Pointer   // LPWSAOVERLAPPED_COMPLETION_ROUTINE optional
): Integer; stdcall;
  external 'WS2_32.dll' name 'WSASendTo';

result := DllCall("WS2_32\WSASendTo"
    , "UPtr", s   ; SOCKET
    , "Ptr", lpBuffers   ; WSABUF*
    , "UInt", dwBufferCount   ; DWORD
    , "Ptr", lpNumberOfBytesSent   ; DWORD* optional, out
    , "UInt", dwFlags   ; DWORD
    , "Ptr", lpTo   ; SOCKADDR* optional
    , "Int", iTolen   ; INT
    , "Ptr", lpOverlapped   ; OVERLAPPED* optional, in/out
    , "Ptr", lpCompletionRoutine   ; LPWSAOVERLAPPED_COMPLETION_ROUTINE optional
    , "Int")   ; return: INT

●WSASendTo(s, lpBuffers, dwBufferCount, lpNumberOfBytesSent, dwFlags, lpTo, iTolen, lpOverlapped, lpCompletionRoutine) = DLL("WS2_32.dll", "int WSASendTo(int, void*, dword, void*, dword, void*, int, void*, void*)")
# 呼び出し: WSASendTo(s, lpBuffers, dwBufferCount, lpNumberOfBytesSent, dwFlags, lpTo, iTolen, lpOverlapped, lpCompletionRoutine)
# s : SOCKET -> "int"
# lpBuffers : WSABUF* -> "void*"
# dwBufferCount : DWORD -> "dword"
# lpNumberOfBytesSent : DWORD* optional, out -> "void*"
# dwFlags : DWORD -> "dword"
# lpTo : SOCKADDR* optional -> "void*"
# iTolen : INT -> "int"
# lpOverlapped : OVERLAPPED* optional, in/out -> "void*"
# lpCompletionRoutine : LPWSAOVERLAPPED_COMPLETION_ROUTINE optional -> "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)。