void
igmp_joingroup(struct in_multi *inm)
{
crit_enter();
if (inm->inm_addr.s_addr == igmp_all_hosts_group
|| inm->inm_ifp->if_flags & IFF_LOOPBACK) {
inm->inm_timer = 0;
inm->inm_state = IGMP_OTHERMEMBER;
} else {
inm->inm_rti = find_rti(inm->inm_ifp);
igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
inm->inm_timer = IGMP_RANDOM_DELAY(
IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
inm->inm_state = IGMP_IREPORTEDLAST;
igmp_timers_are_running = 1;
}
crit_exit();
}
void
igmp_input(struct mbuf *m, int iphlen)
{
register struct igmp *igmp;
register struct ip *ip;
register int igmplen;
register struct ifnet *ifp = m->m_pkthdr.rcvif;
register int minlen;
register struct in_multi *inm;
register struct in_ifaddr *ia;
struct in_multistep step;
struct router_info *rti;
int timer; /** timer value in the igmp query header **/
++igmpstat.igps_rcv_total;
ip = mtod(m, struct ip *);
igmplen = ip->ip_len;
/*
* Validate lengths
*/
if (igmplen < IGMP_MINLEN) {
++igmpstat.igps_rcv_tooshort;
m_freem(m);
return;
}
minlen = iphlen + IGMP_MINLEN;
if ((m->m_flags & M_EXT || m->m_len < minlen) &&
(m = m_pullup(m, minlen)) == 0) {
++igmpstat.igps_rcv_tooshort;
return;
}
/*
* Validate checksum
*/
m->m_data += iphlen;
m->m_len -= iphlen;
igmp = mtod(m, struct igmp *);
if (in_cksum(m, igmplen)) {
++igmpstat.igps_rcv_badsum;
m_freem(m);
return;
}
m->m_data -= iphlen;
m->m_len += iphlen;
ip = mtod(m, struct ip *);
timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
rti = find_rti(ifp);
/*
* In the IGMPv2 specification, there are 3 states and a flag.
*
* In Non-Member state, we simply don't have a membership record.
* In Delaying Member state, our timer is running (inm->inm_timer)
* In Idle Member state, our timer is not running (inm->inm_timer==0)
*
* The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
* we have heard a report from another member, or IGMP_IREPORTEDLAST
* if I sent the last report.
*/
switch (igmp->igmp_type) {
case IGMP_MEMBERSHIP_QUERY:
++igmpstat.igps_rcv_queries;
if (ifp->if_flags & IFF_LOOPBACK)
break;
if (igmp->igmp_code == 0) {
/*
* Old router. Remember that the querier on this
* interface is old, and set the timer to the
* value in RFC 1112.
*/
rti->rti_type = IGMP_V1_ROUTER;
rti->rti_time = 0;
timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;
if (ip->ip_dst.s_addr != igmp_all_hosts_group ||
igmp->igmp_group.s_addr != 0) {
++igmpstat.igps_rcv_badqueries;
m_freem(m);
return;
}
} else {
/*
* New router. Simply do the new validity check.
*/
if (igmp->igmp_group.s_addr != 0 &&
!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
++igmpstat.igps_rcv_badqueries;
m_freem(m);
return;
}
}
/*
* - Start the timers in all of our membership records
* that the query applies to for the interface on
* which the query arrived excl. those that belong
* to the "all-hosts" group (224.0.0.1).
* - Restart any timer that is already running but has
* a value longer than the requested timeout.
* - Use the value specified in the query message as
* the maximum timeout.
*/
IN_FIRST_MULTI(step, inm);
while (inm != NULL) {
if (inm->inm_ifp == ifp &&
inm->inm_addr.s_addr != igmp_all_hosts_group &&
(igmp->igmp_group.s_addr == 0 ||
igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
if (inm->inm_timer == 0 ||
inm->inm_timer > timer) {
inm->inm_timer =
IGMP_RANDOM_DELAY(timer);
igmp_timers_are_running = 1;
}
}
IN_NEXT_MULTI(step, inm);
}
break;
case IGMP_V1_MEMBERSHIP_REPORT:
case IGMP_V2_MEMBERSHIP_REPORT:
/*
* For fast leave to work, we have to know that we are the
* last person to send a report for this group. Reports
* can potentially get looped back if we are a multicast
* router, so discard reports sourced by me.
*/
IFP_TO_IA(ifp, ia);
if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr)
break;
++igmpstat.igps_rcv_reports;
if (ifp->if_flags & IFF_LOOPBACK)
break;
if (!IN_MULTICAST(ntohl(igmp->igmp_group.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 demon 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 ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0)
if (ia) ip->ip_src.s_addr = htonl(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;
inm->inm_state = IGMP_OTHERMEMBER;
}
break;
}
/*
* Pass all valid IGMP packets up to any process(es) listening
* on a raw IGMP socket.
*/
rip_input(m, iphlen);
}
