func loadWSASendRecvMsg() error {
	sendRecvMsgFunc.once.Do(func() {
		var s syscall.Handle
		s, sendRecvMsgFunc.err = syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
		if sendRecvMsgFunc.err != nil {
			return
		}
		defer syscall.CloseHandle(s)
		var n uint32
		sendRecvMsgFunc.err = syscall.WSAIoctl(s,

	if err != nil {
		return nil, errnoErr(EINVAL)
	}
	if localSockaddr.Addr.Family == AF_INET {
		localSockaddr := (*RawSockaddrInet4)(unsafe.Pointer(&localSockaddr.Addr))
		localSockFilter := (*RawSockaddrInet4)(unsafe.Pointer(&request.filter.local[0]))
		localSockFilter.Family = AF_INET
		var i int
		for i = 0; i < 4; i++ {
			if localSockaddr.Addr[i] != 0 {
				break
			}
		}

	Port int
	Addr [4]byte
	raw  RawSockaddrInet4
}

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, int32, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, EINVAL
	}
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
}

	Addr [4]byte
	raw  RawSockaddrInet4
}

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, int32, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, syscall.EINVAL
	}
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
}

	StandardDate Systemtime
	StandardBias int32
	DaylightName [32]uint16
	DaylightDate Systemtime
	DaylightBias int32
}

// Socket related.

const (
	AF_UNSPEC  = 0
	AF_UNIX    = 1
	AF_INET    = 2
	AF_INET6   = 23
	AF_NETBIOS = 17

	SOCK_STREAM    = 1
	SOCK_DGRAM     = 2
	SOCK_RAW       = 3
	SOCK_SEQPACKET = 5

	IPPROTO_IP   = 0
	IPPROTO_IPV6 = 0x29
	IPPROTO_TCP  = 6

}

// SockaddrL2TPIP implements the Sockaddr interface for IPPROTO_L2TP/AF_INET sockets.
type SockaddrL2TPIP struct {
	Addr   [4]byte
	ConnId uint32
	raw    RawSockaddrL2TPIP
}

func (sa *SockaddrL2TPIP) sockaddr() (unsafe.Pointer, _Socklen, error) {
	sa.raw.Family = AF_INET
	sa.raw.Conn_id = sa.ConnId
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), SizeofSockaddrL2TPIP, nil

	return Mknod(path, mode|S_IFIFO, 0)
}

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, EINVAL
	}
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil
}

	StandardBias int32
	DaylightName [32]uint16
	DaylightDate Systemtime
	DaylightBias int32
}

// Socket related.

const (
	AF_UNSPEC  = 0
	AF_UNIX    = 1
	AF_INET    = 2
	AF_NETBIOS = 17
	AF_INET6   = 23
	AF_IRDA    = 26
	AF_BTH     = 32

	SOCK_STREAM    = 1
	SOCK_DGRAM     = 2
	SOCK_RAW       = 3
	SOCK_RDM       = 4
	SOCK_SEQPACKET = 5

	AF_DATAKIT                      = 9
	AF_DLI                          = 13
	AF_ECMA                         = 8
	AF_HYLINK                       = 15
	AF_IMPLINK                      = 3
	AF_INET                         = 2
	AF_INET6                        = 19
	AF_INTF                         = 20
	AF_IUCV                         = 17
	AF_LAT                          = 14
	AF_LINK                         = 18

	AF_ECMA                       = 0x8
	AF_FILE                       = 0x1
	AF_GOSIP                      = 0x16
	AF_HYLINK                     = 0xf
	AF_IMPLINK                    = 0x3
	AF_INET                       = 0x2
	AF_INET6                      = 0x1a
	AF_INET_OFFLOAD               = 0x1e
	AF_IPX                        = 0x17
	AF_KEY                        = 0x1b
	AF_LAT                        = 0xe