Function sooptcopyout

freebsd/kern/uipc_socket.c:3194–3219

* Helper routine for getsockopt. */

 * Helper routine for getsockopt.
 */
int
sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
{
	int	error;
	size_t	valsize;

	error = 0;

	/*
	 * Documented get behavior is that we always return a value, possibly
	 * truncated to fit in the user's buffer.  Traditional behavior is
	 * that we always tell the user precisely how much we copied, rather
	 * than something useful like the total amount we had available for
	 * her.  Note that this interface is not idempotent; the entire
	 * answer must be generated ahead of time.
	 */
	valsize = min(len, sopt->sopt_valsize);
	sopt->sopt_valsize = valsize;
	if (sopt->sopt_val != NULL) {
		if (sopt->sopt_td != NULL)
			error = copyout(buf, sopt->sopt_val, valsize);
		else
			bcopy(buf, sopt->sopt_val, valsize);
	}
	return (error);
}

int
sogetopt(struct socket *so, struct sockopt *sopt)