n, err = fd.pfd.WriteTo(p, sa)
	runtime.KeepAlive(fd)
	return n, wrapSyscallError(writeToSyscallName, err)
}

func (fd *netFD) writeToInet4(p []byte, sa *syscall.SockaddrInet4) (n int, err error) {
	n, err = fd.pfd.WriteToInet4(p, sa)
	runtime.KeepAlive(fd)
	return n, wrapSyscallError(writeToSyscallName, err)
}

		return 0, errMissingAddress
	}

	switch c.fd.family {
	case syscall.AF_INET:
		sa, err := ipToSockaddrInet4(addr.IP, addr.Port)
		if err != nil {
			return 0, err
		}
		return c.fd.writeToInet4(b, &sa)
	case syscall.AF_INET6:
		sa, err := ipToSockaddrInet6(addr.IP, addr.Port, addr.Zone)
		if err != nil {
			return 0, err
		}
		return c.fd.writeToInet6(b, &sa)
	default:

		if nn == len(p) {
			return nn, err
		}
		if err != nil {
			return nn, err
		}
		if n == 0 {
			return nn, io.ErrUnexpectedEOF
		}
	}
}

// WriteToInet4 wraps the sendto network call for IPv4 addresses.
func (fd *FD) WriteToInet4(p []byte, sa *syscall.SockaddrInet4) (int, error) {
	if err := fd.writeLock(); err != nil {
		return 0, err
	}
	defer fd.writeUnlock()

		})
		ntotal += int(n)
		if err != nil {
			return ntotal, err
		}
		buf = buf[n:]
	}
	return ntotal, nil
}

// WriteToInet4 is WriteTo, specialized for syscall.SockaddrInet4.
func (fd *FD) WriteToInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error) {
	if err := fd.writeLock(); err != nil {
		return 0, err
	}
	defer fd.writeUnlock()

	if len(buf) == 0 {

	block := true
	if len(ffd.fd.net) >= 3 && ffd.fd.net[:3] == "udp" {
		block = false
	}
	return peer.queue.send(ffd.writeDeadline.Load(), p, ffd.fd.laddr.(sockaddr), block)
}

func (ffd *fakeNetFD) writeToInet4(p []byte, sa *syscall.SockaddrInet4) (n int, err error) {
	return ffd.writeTo(p, sa)
}

func (ffd *fakeNetFD) writeToInet6(p []byte, sa *syscall.SockaddrInet6) (n int, err error) {
	return ffd.writeTo(p, sa)