Function igmp_handle_state_change

freebsd/netinet/igmp.c:2509–2556

* Issue an intermediate state change during the IGMP life-cycle. */

 * Issue an intermediate state change during the IGMP life-cycle.
 */
static int
igmp_handle_state_change(struct in_multi *inm, struct igmp_ifsoftc *igi)
{
	struct ifnet		*ifp;
	int			 retval;

	CTR4(KTR_IGMPV3, "%s: state change for 0x%08x on ifp %p(%s)", __func__,
	    ntohl(inm->inm_addr.s_addr), inm->inm_ifp, inm->inm_ifp->if_xname);

	ifp = inm->inm_ifp;

	IN_MULTI_LIST_LOCK_ASSERT();
	IGMP_LOCK_ASSERT();

	KASSERT(igi && igi->igi_ifp == ifp, ("%s: inconsistent ifp", __func__));

	if ((ifp->if_flags & IFF_LOOPBACK) ||
	    (igi->igi_flags & IGIF_SILENT) ||
	    !igmp_isgroupreported(inm->inm_addr) ||
	    (igi->igi_version != IGMP_VERSION_3)) {
		if (!igmp_isgroupreported(inm->inm_addr)) {
			CTR1(KTR_IGMPV3,
"%s: not kicking state machine for silent group", __func__);
		}
		CTR1(KTR_IGMPV3, "%s: nothing to do", __func__);
		inm_commit(inm);
		CTR3(KTR_IGMPV3, "%s: T1 -> T0 for 0x%08x/%s", __func__,
		    ntohl(inm->inm_addr.s_addr), inm->inm_ifp->if_xname);
		return (0);
	}

	mbufq_drain(&inm->inm_scq);

	retval = igmp_v3_enqueue_group_record(&inm->inm_scq, inm, 1, 0, 0);
	CTR2(KTR_IGMPV3, "%s: enqueue record = %d", __func__, retval);
	if (retval <= 0)
		return (-retval);

	/*
	 * If record(s) were enqueued, start the state-change
	 * report timer for this group.
	 */
	inm->inm_scrv = ((igi->igi_flags & IGIF_LOOPBACK) ? 1 : igi->igi_rv);
	inm->inm_sctimer = 1;
	V_state_change_timers_running = 1;

	return (0);
}

/*
 * Perform the final leave for an IGMP group.