do_sendto(int fd,
		const struct sockaddr *from, const struct sockaddr *to, socklen_t addrlen,
		msg_t *msg, ssize_t len)
{
	ssize_t ret;

	errno = 0;
	if (!from) {
		ret = sendto(fd, msg, len, MSG_DONTWAIT, to, addrlen);
	} else {
		ret = send_to_from(fd, msg, len, MSG_DONTWAIT, to, from, addrlen);
	}
	if (ret != len) {
		bb_perror_msg("send failed");
		return -1;
	}
	return 0;
}
do_sendto(int fd,
		const struct sockaddr *from, const struct sockaddr *to, socklen_t addrlen,
		msg_t *msg, ssize_t len)
{
	ssize_t ret;

	errno = 0;
	if (!from) {
		ret = sendto(fd, msg, len, MSG_DONTWAIT, to, addrlen);
	} else {
		ret = send_to_from(fd, msg, len, MSG_DONTWAIT, to, from, addrlen);
	}
	if (ret != len) {
		bb_perror_msg("send failed");
		return -1;
	}
	return 0;
}