Function mld_v2_input_query

freebsd/netinet6/mld6.c:813–982

* Process a received MLDv2 general, group-specific or * group-and-source-specific query. * * Assumes that mld points to a struct mldv2_query which is stored in * contiguous memory. * * Return 0 if successful, otherwise an appropriate error code is returned. */

 * Return 0 if successful, otherwise an appropriate error code is returned.
 */
static int
mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
    struct mbuf *m, struct mldv2_query *mld, const int off, const int icmp6len)
{
	struct mld_ifsoftc	*mli;
	struct in6_multi	*inm;
	uint32_t		 maxdelay, nsrc, qqi;
	int			 is_general_query;
	uint16_t		 timer;
	uint8_t			 qrv;
#ifdef KTR
	char			 ip6tbuf[INET6_ADDRSTRLEN];
#endif

	NET_EPOCH_ASSERT();

	if (!mld_v2enable) {
		CTR3(KTR_MLD, "ignore v2 query src %s on ifp %p(%s)",
		    ip6_sprintf(ip6tbuf, &ip6->ip6_src),
		    ifp, if_name(ifp));
		return (0);
	}

	/*
	 * RFC3810 Section 6.2: MLD queries must originate from
	 * a router's link-local address.
	 */
	if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
		CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
		    ip6_sprintf(ip6tbuf, &ip6->ip6_src),
		    ifp, if_name(ifp));
		return (0);
	}

	is_general_query = 0;

	CTR2(KTR_MLD, "input v2 query on ifp %p(%s)", ifp, if_name(ifp));

	maxdelay = ntohs(mld->mld_maxdelay);	/* in 1/10ths of a second */
	if (maxdelay >= 32768) {
		maxdelay = (MLD_MRC_MANT(maxdelay) | 0x1000) <<
			   (MLD_MRC_EXP(maxdelay) + 3);
	}
	timer = (maxdelay * PR_FASTHZ) / MLD_TIMER_SCALE;
	if (timer == 0)
		timer = 1;

	qrv = MLD_QRV(mld->mld_misc);
	if (qrv < 2) {
		CTR3(KTR_MLD, "%s: clamping qrv %d to %d", __func__,
		    qrv, MLD_RV_INIT);
		qrv = MLD_RV_INIT;
	}

	qqi = mld->mld_qqi;
	if (qqi >= 128) {
		qqi = MLD_QQIC_MANT(mld->mld_qqi) <<
		     (MLD_QQIC_EXP(mld->mld_qqi) + 3);