Function in6p_findmoptions

freebsd/netinet6/in6_mcast.c:1555–1580

* Given an inpcb, return its multicast options structure pointer. Accepts * an unlocked inpcb pointer, but will return it locked. May sleep. * * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held. * SMPng: NOTE: Returns with the INP write lock held. */

 * SMPng: NOTE: Returns with the INP write lock held.
 */
static struct ip6_moptions *
in6p_findmoptions(struct inpcb *inp)
{
	struct ip6_moptions	 *imo;

	INP_WLOCK(inp);
	if (inp->in6p_moptions != NULL)
		return (inp->in6p_moptions);

	INP_WUNLOCK(inp);

	imo = malloc(sizeof(*imo), M_IP6MOPTS, M_WAITOK);

	imo->im6o_multicast_ifp = NULL;
	imo->im6o_multicast_hlim = V_ip6_defmcasthlim;
	imo->im6o_multicast_loop = in6_mcast_loop;
	STAILQ_INIT(&imo->im6o_head);

	INP_WLOCK(inp);
	if (inp->in6p_moptions != NULL) {
		free(imo, M_IP6MOPTS);
		return (inp->in6p_moptions);
	}
	inp->in6p_moptions = imo;
	return (imo);
}

/*
 * Discard the IPv6 multicast options (and source filters).