//sysnb	socket(domain int, typ int, proto int) (fd int, err error)
//sysnb	socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)
//sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
//sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
//sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)

	_SYS_clone3     = 435
	_SYS_faccessat2 = 439
	_SYS_fchmodat2  = 452
)

//sys	Dup2(oldfd int, newfd int) (err error)
//sys	Fchown(fd int, uid int, gid int) (err error)
//sys	Fstat(fd int, stat *Stat_t) (err error)
//sys	Fstatfs(fd int, buf *Statfs_t) (err error)
//sys	Ftruncate(fd int, length int64) (err error)
//sysnb	Getegid() (egid int)
//sysnb	Geteuid() (euid int)
//sysnb	Getgid() (gid int)

func futimes(fd int, timeval *[2]Timeval) (err error) {
	_, _, e1 := Syscall(SYS_FUTIMES, uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

func fcntl(fd int, cmd int, arg int) (val int, err error) {
	r0, _, e1 := Syscall(SYS_FCNTL, uintptr(fd), uintptr(cmd), uintptr(arg))

func futimes(fd int, timeval *[2]Timeval) (err error) {
	_, _, e1 := Syscall(SYS_FUTIMES, uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

func fcntl(fd int, cmd int, arg int) (val int, err error) {
	r0, _, e1 := Syscall(SYS_FCNTL, uintptr(fd), uintptr(cmd), uintptr(arg))

	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

func Fstatfs(fd int, buf *Statfs_t) (err error) {
	_, _, e1 := Syscall(SYS_FSTATFS, uintptr(fd), uintptr(unsafe.Pointer(buf)), 0)
	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

	SYS_FCHOWNAT             = 464 // { int|sys||fchownat(int fd, const char *path, uid_t owner, gid_t group, int flag); }
	SYS_FEXECVE              = 465 // { int|sys||fexecve(int fd, char * const *argp, char * const *envp); }
	SYS_FSTATAT              = 466 // { int|sys||fstatat(int fd, const char *path, struct stat *buf, int flag); }

	SYS_FCHOWNAT             = 464 // { int|sys||fchownat(int fd, const char *path, uid_t owner, gid_t group, int flag); }
	SYS_FEXECVE              = 465 // { int|sys||fexecve(int fd, char * const *argp, char * const *envp); }
	SYS_FSTATAT              = 466 // { int|sys||fstatat(int fd, const char *path, struct stat *buf, int flag); }

	SYS_FCHOWNAT             = 464 // { int|sys||fchownat(int fd, const char *path, uid_t owner, gid_t group, int flag); }
	SYS_FEXECVE              = 465 // { int|sys||fexecve(int fd, char * const *argp, char * const *envp); }
	SYS_FSTATAT              = 466 // { int|sys||fstatat(int fd, const char *path, struct stat *buf, int flag); }

//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Dup2(from int, to int) (err error)
//sys	dup3(from int, to int, flags int) (err error)
//sys	Fchdir(fd int) (err error)
//sys	Fchflags(fd int, flags int) (err error)
//sys	Fchmod(fd int, mode uint32) (err error)
//sys	Fchown(fd int, uid int, gid int) (err error)
//sys	Flock(fd int, how int) (err error)

func setKeepAliveInterval(fd *netFD, d time.Duration) error {
	if d == 0 {
		d = defaultTCPKeepAliveInterval
	} else if d < 0 {
		return nil
	}

	// The kernel expects seconds so round to next highest second.
	secs := int(roundDurationUp(d, time.Second))
	err := fd.pfd.SetsockoptInt(syscall.IPPROTO_TCP, sysTCP_KEEPINTVL, secs)
	runtime.KeepAlive(fd)
	return wrapSyscallError("setsockopt", err)
}