Addr RawSockaddr
	Pad  [96]uint8
}

type Iovec struct {
	Base *byte
	Len  uint32
}

type Msghdr struct {
	Name       *byte
	Namelen    uint32
	Iov        *Iovec
	Iovlen     uint32
	Control    *byte
	Controllen uint32
	Flags      int32
}

type Cmsghdr struct {
	Len   uint32
	Level int32
	Type  int32
}

type ifreq struct {
	Ifrn [16]byte
	Ifru [16]byte

	Pad  [96]int8
}

type Iovec struct {
	Base *byte
	Len  uint64
}

type Msghdr struct {
	Name       *byte
	Namelen    uint32
	Iov        *Iovec
	Iovlen     uint64
	Control    *byte
	Controllen uint64
	Flags      int32
	_          [4]byte
}

type Cmsghdr struct {
	Len   uint64
	Level int32
	Type  int32
}

type ifreq struct {
	Ifrn [16]byte

	Addr RawSockaddr
	Pad  [96]int8
}

type Iovec struct {
	Base *byte
	Len  uint32
}

type Msghdr struct {
	Name       *byte
	Namelen    uint32
	Iov        *Iovec
	Iovlen     uint32
	Control    *byte
	Controllen uint32
	Flags      int32
}

type Cmsghdr struct {
	Len   uint32
	Level int32
	Type  int32
}

type ifreq struct {
	Ifrn [16]byte
	Ifru [16]byte

	Pad  [96]int8
}

type Iovec struct {
	Base *byte
	Len  uint64
}

type Msghdr struct {
	Name       *byte
	Namelen    uint32
	Iov        *Iovec
	Iovlen     uint64
	Control    *byte
	Controllen uint64
	Flags      int32
	_          [4]byte
}

type Cmsghdr struct {
	Len   uint64
	Level int32
	Type  int32
}

type ifreq struct {
	Ifrn [16]byte

	Pad  [96]int8
}

type Iovec struct {
	Base *byte
	Len  uint64
}

type Msghdr struct {
	Name       *byte
	Namelen    uint32
	Iov        *Iovec
	Iovlen     uint64
	Control    *byte
	Controllen uint64
	Flags      int32
	_          [4]byte
}

type Cmsghdr struct {
	Len   uint64
	Level int32
	Type  int32
}

type ifreq struct {
	Ifrn [16]byte

	Pad  [96]int8
}

type Iovec struct {
	Base *byte
	Len  uint64
}

type Msghdr struct {
	Name       *byte
	Namelen    uint32
	Iov        *Iovec
	Iovlen     uint64
	Control    *byte
	Controllen uint64
	Flags      int32
	_          [4]byte
}

type Cmsghdr struct {
	Len   uint64
	Level int32
	Type  int32
}

type ifreq struct {
	Ifrn [16]byte

	Pad  [96]int8
}

type Iovec struct {
	Base *byte
	Len  uint64
}

type Msghdr struct {
	Name       *byte
	Namelen    uint32
	Iov        *Iovec
	Iovlen     uint64
	Control    *byte
	Controllen uint64
	Flags      int32
	_          [4]byte
}

type Cmsghdr struct {
	Len   uint64
	Level int32
	Type  int32
}

type ifreq struct {
	Ifrn [16]byte

		tty = s
	} else {
		tty = s[:idx]
	}
	return
}

func (iov *Iovec) SetLen(length int) {
	iov.Len = uint64(length)
}

func (msghdr *Msghdr) SetControllen(length int) {
	msghdr.Controllen = int32(length)
}

func (cmsg *Cmsghdr) SetLen(length int) {
	cmsg.Len = int32(length)
}

//sys   fcntl(fd int, cmd int, arg int) (val int, err error)

	req := &nl.NetlinkRequest{
		// netlink message header
		// (definition: https://github.com/torvalds/linux/blob/v6.7/include/uapi/linux/netlink.h#L44-L58)
		NlMsghdr: unix.NlMsghdr{
			Len:   uint32(unix.SizeofNlMsghdr),
			Type:  uint16(cmd | (unix.NFNL_SUBSYS_ACCT << 8)),
			Flags: flags,
		},
		Sockets: map[int]*nl.SocketHandle{
			unix.NETLINK_NETFILTER: {Socket: n.socket},
		},

//sys	Shutdown(s int, how int) (err error)

// In order to use msghdr structure with Control, Controllen in golang.org/x/net,
// nrecvmsg and nsendmsg must be used.
//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error) = nrecvmsg
//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error) = nsendmsg

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {