igmp.c

eCos/RedBoot for勤研ARM AnywhereII(4510) 含全部源代码

					case IGMP_AWAKENING_MEMBER:
						inm->inm_state =
						    IGMP_DELAYING_MEMBER;
						inm->inm_timer =
						    IGMP_RANDOM_DELAY(timer);
						igmp_timers_are_running = 1;
						break;
					case IGMP_SLEEPING_MEMBER:
						inm->inm_state =
						    IGMP_AWAKENING_MEMBER;
						break;
					}
				}
				IN_NEXT_MULTI(step, inm);
			}
		}

		break;

	case IGMP_v1_HOST_MEMBERSHIP_REPORT:
		++igmpstat.igps_rcv_reports;

		if (ifp->if_flags & IFF_LOOPBACK)
			break;

		if (!IN_MULTICAST(igmp->igmp_group.s_addr) ||
		    igmp->igmp_group.s_addr != ip->ip_dst.s_addr) {
			++igmpstat.igps_rcv_badreports;
			m_freem(m);
			return;
		}

		/*
		 * KLUDGE: if the IP source address of the report has an
		 * unspecified (i.e., zero) subnet number, as is allowed for
		 * a booting host, replace it with the correct subnet number
		 * so that a process-level multicast routing daemon can
		 * determine which subnet it arrived from.  This is necessary
		 * to compensate for the lack of any way for a process to
		 * determine the arrival interface of an incoming packet.
		 */
		if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) {
			IFP_TO_IA(ifp, ia);
			if (ia)
				ip->ip_src.s_addr = ia->ia_subnet;
		}

		/*
		 * If we belong to the group being reported, stop
		 * our timer for that group.
		 */
		IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
		if (inm != NULL) {
			inm->inm_timer = 0;
			++igmpstat.igps_rcv_ourreports;

			switch (inm->inm_state) {
			case IGMP_IDLE_MEMBER:
			case IGMP_LAZY_MEMBER:
			case IGMP_AWAKENING_MEMBER:
			case IGMP_SLEEPING_MEMBER:
				inm->inm_state = IGMP_SLEEPING_MEMBER;
				break;
			case IGMP_DELAYING_MEMBER:
				if (inm->inm_rti->rti_type == IGMP_v1_ROUTER)
					inm->inm_state = IGMP_LAZY_MEMBER;
				else
					inm->inm_state = IGMP_SLEEPING_MEMBER;
				break;
			}
		}

		break;

	case IGMP_v2_HOST_MEMBERSHIP_REPORT:
#ifdef MROUTING
		/*
		 * Make sure we don't hear our own membership report.  Fast
		 * leave requires knowing that we are the only member of a
		 * group.
		 */
		IFP_TO_IA(ifp, ia);
		if (ia && ip->ip_src.s_addr == ia->ia_addr.sin_addr.s_addr)
			break;
#endif

		++igmpstat.igps_rcv_reports;

		if (ifp->if_flags & IFF_LOOPBACK)
			break;

		if (!IN_MULTICAST(igmp->igmp_group.s_addr) ||
		    igmp->igmp_group.s_addr != ip->ip_dst.s_addr) {
			++igmpstat.igps_rcv_badreports;
			m_freem(m);
			return;
		}

		/*
		 * KLUDGE: if the IP source address of the report has an
		 * unspecified (i.e., zero) subnet number, as is allowed for
		 * a booting host, replace it with the correct subnet number
		 * so that a process-level multicast routing daemon can
		 * determine which subnet it arrived from.  This is necessary
		 * to compensate for the lack of any way for a process to
		 * determine the arrival interface of an incoming packet.
		 */
		if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) {
#ifndef MROUTING
			IFP_TO_IA(ifp, ia);
#endif
			if (ia)
				ip->ip_src.s_addr = ia->ia_subnet;
		}

		/*
		 * If we belong to the group being reported, stop
		 * our timer for that group.
		 */
		IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
		if (inm != NULL) {
			inm->inm_timer = 0;
			++igmpstat.igps_rcv_ourreports;

			switch (inm->inm_state) {
			case IGMP_DELAYING_MEMBER:
			case IGMP_IDLE_MEMBER:
			case IGMP_AWAKENING_MEMBER:
				inm->inm_state = IGMP_LAZY_MEMBER;
				break;
			case IGMP_LAZY_MEMBER:
			case IGMP_SLEEPING_MEMBER:
				break;
			}
		}

		break;

	}

	/*
	 * Pass all valid IGMP packets up to any process(es) listening
	 * on a raw IGMP socket.
	 */
	rip_input(m, iphlen, proto);
	return;
}

void
igmp_joingroup(inm)
	struct in_multi *inm;
{
	int s = splsoftnet();

	inm->inm_state = IGMP_IDLE_MEMBER;

	if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
	    (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) {
		igmp_sendpkt(inm, rti_fill(inm));
		inm->inm_state = IGMP_DELAYING_MEMBER;
		inm->inm_timer = IGMP_RANDOM_DELAY(
		    IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ);
		igmp_timers_are_running = 1;
	} else
		inm->inm_timer = 0;
	splx(s);
}

void
igmp_leavegroup(inm)
	struct in_multi *inm;
{

	switch (inm->inm_state) {
	case IGMP_DELAYING_MEMBER:
	case IGMP_IDLE_MEMBER:
		if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
		    (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0)
			if (inm->inm_rti->rti_type != IGMP_v1_ROUTER)
				igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE);
		break;
	case IGMP_LAZY_MEMBER:
	case IGMP_AWAKENING_MEMBER:
	case IGMP_SLEEPING_MEMBER:
		break;
	}
}

void
igmp_fasttimo()
{
	register struct in_multi *inm;
	struct in_multistep step;
	int s;

	/*
	 * Quick check to see if any work needs to be done, in order
	 * to minimize the overhead of fasttimo processing.
	 */
	if (!igmp_timers_are_running)
		return;

	s = splsoftnet();
	igmp_timers_are_running = 0;
	IN_FIRST_MULTI(step, inm);
	while (inm != NULL) {
		if (inm->inm_timer == 0) {
			/* do nothing */
		} else if (--inm->inm_timer == 0) {
			if (inm->inm_state == IGMP_DELAYING_MEMBER) {
				if (inm->inm_rti->rti_type == IGMP_v1_ROUTER)
					igmp_sendpkt(inm,
					    IGMP_v1_HOST_MEMBERSHIP_REPORT);
				else
					igmp_sendpkt(inm,
					    IGMP_v2_HOST_MEMBERSHIP_REPORT);
				inm->inm_state = IGMP_IDLE_MEMBER;
			}
		} else {
			igmp_timers_are_running = 1;
		}
		IN_NEXT_MULTI(step, inm);
	}
	splx(s);
}

void
igmp_slowtimo()
{
	register struct router_info *rti;
	int s;

	s = splsoftnet();
	for (rti = rti_head; rti != 0; rti = rti->rti_next) {
		if (rti->rti_type == IGMP_v1_ROUTER &&
		    ++rti->rti_age >= IGMP_AGE_THRESHOLD) {
			rti->rti_type = IGMP_v2_ROUTER;
		}
	}
	splx(s);
}

void
igmp_sendpkt(inm, type)
	struct in_multi *inm;
	int type;
{
	struct mbuf *m;
	struct igmp *igmp;
	struct ip *ip;
	struct ip_moptions imo;
#ifdef MROUTING
	extern struct socket *ip_mrouter;
#endif /* MROUTING */

	MGETHDR(m, M_DONTWAIT, MT_HEADER);
	if (m == NULL)
		return;
	/*
	 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN
	 * is smaller than mbuf size returned by MGETHDR.
	 */
	m->m_data += max_linkhdr;
	m->m_len = sizeof(struct ip) + IGMP_MINLEN;
	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;

	ip = mtod(m, struct ip *);
	ip->ip_tos = 0;
	ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
	ip->ip_off = 0;
	ip->ip_p = IPPROTO_IGMP;
	ip->ip_src.s_addr = INADDR_ANY;
	ip->ip_dst = inm->inm_addr;

	m->m_data += sizeof(struct ip);
	m->m_len -= sizeof(struct ip);
	igmp = mtod(m, struct igmp *);
	igmp->igmp_type = type;
	igmp->igmp_code = 0;
	igmp->igmp_group = inm->inm_addr;
	igmp->igmp_cksum = 0;
	igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
	m->m_data -= sizeof(struct ip);
	m->m_len += sizeof(struct ip);

	imo.imo_multicast_ifp = inm->inm_ifp;
	imo.imo_multicast_ttl = 1;
#ifdef RSVP_ISI
	imo.imo_multicast_vif = -1;
#endif
	/*
	 * Request loopback of the report if we are acting as a multicast
	 * router, so that the process-level routing demon can hear it.
	 */
#ifdef MROUTING
	imo.imo_multicast_loop = (ip_mrouter != NULL);
#else
	imo.imo_multicast_loop = 0;
#endif /* MROUTING */

#if 0 /*KAME IPSEC*/
	m->m_pkthdr.rcvif = NULL;
#endif /*IPSEC*/
	ip_output(m, (struct mbuf *)0, (struct route *)0, IP_MULTICASTOPTS,
	    &imo, NULL);

	++igmpstat.igps_snd_reports;
}