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/* $OpenBSD: igmp.c,v 1.83 2023/09/16 09:33:27 mpi Exp $ */
/* $NetBSD: igmp.c,v 1.15 1996/02/13 23:41:25 christos Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Copyright (c) 1988 Stephen Deering.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Stephen Deering of Stanford University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)igmp.c 8.2 (Berkeley) 5/3/95
*/
/*
* Internet Group Management Protocol (IGMP) routines.
*
* Written by Steve Deering, Stanford, May 1988.
* Modified by Rosen Sharma, Stanford, Aug 1994.
* Modified by Bill Fenner, Xerox PARC, Feb 1995.
*
* MULTICAST Revision: 1.3
*/
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/igmp.h>
#include <netinet/igmp_var.h>
#include <sys/stdarg.h>
#define IP_MULTICASTOPTS 0
int igmp_timers_are_running; /* [N] shortcut for fast timer */
static LIST_HEAD(, router_info) rti_head;
static struct mbuf *router_alert;
struct cpumem *igmpcounters;
void igmp_checktimer(struct ifnet *);
void igmp_sendpkt(struct ifnet *, struct in_multi *, int, in_addr_t);
int rti_fill(struct in_multi *);
struct router_info * rti_find(struct ifnet *);
int igmp_input_if(struct ifnet *, struct mbuf **, int *, int, int);
int igmp_sysctl_igmpstat(void *, size_t *, void *);
void
igmp_init(void)
{
struct ipoption *ra;
igmp_timers_are_running = 0;
LIST_INIT(&rti_head);
igmpcounters = counters_alloc(igps_ncounters);
router_alert = m_get(M_WAIT, MT_DATA);
/*
* Construct a Router Alert option (RAO) to use in report
* messages as required by RFC2236. This option has the
* following format:
*
* | 10010100 | 00000100 | 2 octet value |
*
* where a value of "0" indicates that routers shall examine
* the packet.
*/
ra = mtod(router_alert, struct ipoption *);
ra->ipopt_dst.s_addr = INADDR_ANY;
ra->ipopt_list[0] = IPOPT_RA;
ra->ipopt_list[1] = 0x04;
ra->ipopt_list[2] = 0x00;
ra->ipopt_list[3] = 0x00;
router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1];
}
int
rti_fill(struct in_multi *inm)
{
struct router_info *rti;
LIST_FOREACH(rti, &rti_head, rti_list) {
if (rti->rti_ifidx == inm->inm_ifidx) {
inm->inm_rti = rti;
if (rti->rti_type == IGMP_v1_ROUTER)
return (IGMP_v1_HOST_MEMBERSHIP_REPORT);
else
return (IGMP_v2_HOST_MEMBERSHIP_REPORT);
}
}
rti = malloc(sizeof(*rti), M_MRTABLE, M_WAITOK);
rti->rti_ifidx = inm->inm_ifidx;
rti->rti_type = IGMP_v2_ROUTER;
LIST_INSERT_HEAD(&rti_head, rti, rti_list);
inm->inm_rti = rti;
return (IGMP_v2_HOST_MEMBERSHIP_REPORT);
}
struct router_info *
rti_find(struct ifnet *ifp)
{
struct router_info *rti;
KERNEL_ASSERT_LOCKED();
LIST_FOREACH(rti, &rti_head, rti_list) {
if (rti->rti_ifidx == ifp->if_index)
return (rti);
}
rti = malloc(sizeof(*rti), M_MRTABLE, M_NOWAIT);
if (rti == NULL)
return (NULL);
rti->rti_ifidx = ifp->if_index;
rti->rti_type = IGMP_v2_ROUTER;
LIST_INSERT_HEAD(&rti_head, rti, rti_list);
return (rti);
}
void
rti_delete(struct ifnet *ifp)
{
struct router_info *rti, *trti;
LIST_FOREACH_SAFE(rti, &rti_head, rti_list, trti) {
if (rti->rti_ifidx == ifp->if_index) {
LIST_REMOVE(rti, rti_list);
free(rti, M_MRTABLE, sizeof(*rti));
break;
}
}
}
int
igmp_input(struct mbuf **mp, int *offp, int proto, int af)
{
struct ifnet *ifp;
igmpstat_inc(igps_rcv_total);
ifp = if_get((*mp)->m_pkthdr.ph_ifidx);
if (ifp == NULL) {
m_freemp(mp);
return IPPROTO_DONE;
}
KERNEL_LOCK();
proto = igmp_input_if(ifp, mp, offp, proto, af);
KERNEL_UNLOCK();
if_put(ifp);
return proto;
}
int
igmp_input_if(struct ifnet *ifp, struct mbuf **mp, int *offp, int proto, int af)
{
struct mbuf *m = *mp;
int iphlen = *offp;
struct ip *ip = mtod(m, struct ip *);
struct igmp *igmp;
int igmplen;
int minlen;
struct ifmaddr *ifma;
struct in_multi *inm;
struct router_info *rti;
struct in_ifaddr *ia;
int timer;
igmplen = ntohs(ip->ip_len) - iphlen;
/*
* Validate lengths
*/
if (igmplen < IGMP_MINLEN) {
igmpstat_inc(igps_rcv_tooshort);
m_freem(m);
return IPPROTO_DONE;
}
minlen = iphlen + IGMP_MINLEN;
if ((m->m_flags & M_EXT || m->m_len < minlen) &&
(m = *mp = m_pullup(m, minlen)) == NULL) {
igmpstat_inc(igps_rcv_tooshort);
return IPPROTO_DONE;
}
/*
* Validate checksum
*/
m->m_data += iphlen;
m->m_len -= iphlen;
igmp = mtod(m, struct igmp *);
if (in_cksum(m, igmplen)) {
igmpstat_inc(igps_rcv_badsum);
m_freem(m);
return IPPROTO_DONE;
}
m->m_data -= iphlen;
m->m_len += iphlen;
ip = mtod(m, struct ip *);
switch (igmp->igmp_type) {
case IGMP_HOST_MEMBERSHIP_QUERY:
igmpstat_inc(igps_rcv_queries);
if (ifp->if_flags & IFF_LOOPBACK)
break;
if (igmp->igmp_code == 0) {
rti = rti_find(ifp);
if (rti == NULL) {
m_freem(m);
return IPPROTO_DONE;
}
rti->rti_type = IGMP_v1_ROUTER;
rti->rti_age = 0;
if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) {
igmpstat_inc(igps_rcv_badqueries);
m_freem(m);
return IPPROTO_DONE;
}
/*
* Start the timers in all of our membership records
* for the interface on which the query arrived,
* except those that are already running and those
* that belong to a "local" group (224.0.0.X).
*/
TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) {
if (ifma->ifma_addr->sa_family != AF_INET)
continue;
inm = ifmatoinm(ifma);
if (inm->inm_timer == 0 &&
!IN_LOCAL_GROUP(inm->inm_addr.s_addr)) {
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 {
if (!IN_MULTICAST(ip->ip_dst.s_addr)) {
igmpstat_inc(igps_rcv_badqueries);
m_freem(m);
return IPPROTO_DONE;
}
timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
if (timer == 0)
timer = 1;
/*
* Start the timers in all of our membership records
* for the interface on which the query arrived,
* except those that are already running and those
* that belong to a "local" group (224.0.0.X). For
* timers already running, check if they need to be
* reset.
*/
TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) {
if (ifma->ifma_addr->sa_family != AF_INET)
continue;
inm = ifmatoinm(ifma);
if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
(ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP ||
ip->ip_dst.s_addr == inm->inm_addr.s_addr)) {
switch (inm->inm_state) {
case IGMP_DELAYING_MEMBER:
if (inm->inm_timer <= timer)
break;
/* FALLTHROUGH */
case IGMP_IDLE_MEMBER:
case IGMP_LAZY_MEMBER:
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;
}
}
}
}
break;
case IGMP_v1_HOST_MEMBERSHIP_REPORT:
igmpstat_inc(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_inc(igps_rcv_badreports);
m_freem(m);
return IPPROTO_DONE;
}
/*
* 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_net;
}
/*
* 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_inc(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_inc(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_inc(igps_rcv_badreports);
m_freem(m);
return IPPROTO_DONE;
}
/*
* 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_net;
}
/*
* 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_inc(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.
*/
return rip_input(mp, offp, proto, af);
}
void
igmp_joingroup(struct in_multi *inm, struct ifnet *ifp)
{
int i;
inm->inm_state = IGMP_IDLE_MEMBER;
if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
(ifp->if_flags & IFF_LOOPBACK) == 0) {
i = rti_fill(inm);
igmp_sendpkt(ifp, inm, i, 0);
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;
}
void
igmp_leavegroup(struct in_multi *inm, struct ifnet *ifp)
{
switch (inm->inm_state) {
case IGMP_DELAYING_MEMBER:
case IGMP_IDLE_MEMBER:
if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
(ifp->if_flags & IFF_LOOPBACK) == 0)
if (inm->inm_rti->rti_type != IGMP_v1_ROUTER)
igmp_sendpkt(ifp, inm,
IGMP_HOST_LEAVE_MESSAGE,
INADDR_ALLROUTERS_GROUP);
break;
case IGMP_LAZY_MEMBER:
case IGMP_AWAKENING_MEMBER:
case IGMP_SLEEPING_MEMBER:
break;
}
}
void
igmp_fasttimo(void)
{
struct ifnet *ifp;
/*
* Quick check to see if any work needs to be done, in order
* to minimize the overhead of fasttimo processing.
* Variable igmp_timers_are_running is read atomically, but without
* lock intentionally. In case it is not set due to MP races, we may
* miss to check the timers. Then run the loop at next fast timeout.
*/
if (!igmp_timers_are_running)
return;
NET_LOCK();
igmp_timers_are_running = 0;
TAILQ_FOREACH(ifp, &ifnetlist, if_list)
igmp_checktimer(ifp);
NET_UNLOCK();
}
void
igmp_checktimer(struct ifnet *ifp)
{
struct in_multi *inm;
struct ifmaddr *ifma;
NET_ASSERT_LOCKED();
TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) {
if (ifma->ifma_addr->sa_family != AF_INET)
continue;
inm = ifmatoinm(ifma);
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(ifp, inm,
IGMP_v1_HOST_MEMBERSHIP_REPORT, 0);
else
igmp_sendpkt(ifp, inm,
IGMP_v2_HOST_MEMBERSHIP_REPORT, 0);
inm->inm_state = IGMP_IDLE_MEMBER;
}
} else {
igmp_timers_are_running = 1;
}
}
}
void
igmp_slowtimo(void)
{
struct router_info *rti;
NET_LOCK();
LIST_FOREACH(rti, &rti_head, rti_list) {
if (rti->rti_type == IGMP_v1_ROUTER &&
++rti->rti_age >= IGMP_AGE_THRESHOLD) {
rti->rti_type = IGMP_v2_ROUTER;
}
}
NET_UNLOCK();
}
void
igmp_sendpkt(struct ifnet *ifp, struct in_multi *inm, int type,
in_addr_t addr)
{
struct mbuf *m;
struct igmp *igmp;
struct ip *ip;
struct ip_moptions imo;
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 = htons(sizeof(struct ip) + IGMP_MINLEN);
ip->ip_off = 0;
ip->ip_p = IPPROTO_IGMP;
ip->ip_src.s_addr = INADDR_ANY;
if (addr) {
ip->ip_dst.s_addr = addr;
} else {
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);
m->m_pkthdr.ph_rtableid = ifp->if_rdomain;
imo.imo_ifidx = inm->inm_ifidx;
imo.imo_ttl = 1;
/*
* Request loopback of the report if we are acting as a multicast
* router, so that the process-level routing daemon can hear it.
*/
#ifdef MROUTING
imo.imo_loop = (ip_mrouter[ifp->if_rdomain] != NULL);
#else
imo.imo_loop = 0;
#endif /* MROUTING */
ip_output(m, router_alert, NULL, IP_MULTICASTOPTS, &imo, NULL, 0);
igmpstat_inc(igps_snd_reports);
}
/*
* Sysctl for igmp variables.
*/
int
igmp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
void *newp, size_t newlen)
{
/* All sysctl names at this level are terminal. */
if (namelen != 1)
return (ENOTDIR);
switch (name[0]) {
case IGMPCTL_STATS:
if (newp != NULL)
return (EPERM);
return (igmp_sysctl_igmpstat(oldp, oldlenp, newp));
default:
return (EOPNOTSUPP);
}
/* NOTREACHED */
}
int
igmp_sysctl_igmpstat(void *oldp, size_t *oldlenp, void *newp)
{
uint64_t counters[igps_ncounters];
struct igmpstat igmpstat;
u_long *words = (u_long *)&igmpstat;
int i;
CTASSERT(sizeof(igmpstat) == (nitems(counters) * sizeof(u_long)));
memset(&igmpstat, 0, sizeof igmpstat);
counters_read(igmpcounters, counters, nitems(counters), NULL);
for (i = 0; i < nitems(counters); i++)
words[i] = (u_long)counters[i];
return (sysctl_rdstruct(oldp, oldlenp, newp,
&igmpstat, sizeof(igmpstat)));
}
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