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NetBSD/sys/netinet/igmp.c

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/* $NetBSD: igmp.c,v 1.25 2000/06/16 20:21:26 matt 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.
*/
/*
* 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 "opt_mrouting.h"
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/systm.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/igmp.h>
#include <netinet/igmp_var.h>
#include <machine/stdarg.h>
#define IP_MULTICASTOPTS 0
int igmp_timers_are_running;
static struct router_info *rti_head;
void igmp_sendpkt __P((struct in_multi *, int));
static int rti_fill __P((struct in_multi *));
static struct router_info * rti_find __P((struct ifnet *));
void
igmp_init()
{
/*
* To avoid byte-swapping the same value over and over again.
*/
igmp_timers_are_running = 0;
rti_head = 0;
}
static int
rti_fill(inm)
struct in_multi *inm;
{
struct router_info *rti;
for (rti = rti_head; rti != 0; rti = rti->rti_next) {
if (rti->rti_ifp == inm->inm_ifp) {
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 = (struct router_info *)malloc(sizeof(struct router_info),
M_MRTABLE, M_NOWAIT);
rti->rti_ifp = inm->inm_ifp;
rti->rti_type = IGMP_v2_ROUTER;
rti->rti_next = rti_head;
rti_head = rti;
inm->inm_rti = rti;
return (IGMP_v2_HOST_MEMBERSHIP_REPORT);
}
static struct router_info *
rti_find(ifp)
struct ifnet *ifp;
{
struct router_info *rti;
for (rti = rti_head; rti != 0; rti = rti->rti_next) {
if (rti->rti_ifp == ifp)
return (rti);
}
rti = (struct router_info *)malloc(sizeof(struct router_info),
M_MRTABLE, M_NOWAIT);
rti->rti_ifp = ifp;
rti->rti_type = IGMP_v2_ROUTER;
rti->rti_next = rti_head;
rti_head = rti;
return (rti);
}
void
#if __STDC__
igmp_input(struct mbuf *m, ...)
#else
igmp_input(m, va_alist)
struct mbuf *m;
va_dcl
#endif
{
int proto;
int iphlen;
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct ip *ip = mtod(m, struct ip *);
struct igmp *igmp;
int minlen;
struct in_multi *inm;
struct in_multistep step;
struct router_info *rti;
struct in_ifaddr *ia;
int timer;
va_list ap;
va_start(ap, m);
iphlen = va_arg(ap, int);
proto = va_arg(ap, int);
va_end(ap);
++igmpstat.igps_rcv_total;
/*
* Validate lengths
*/
minlen = iphlen + IGMP_MINLEN;
if (ip->ip_len < minlen) {
++igmpstat.igps_rcv_tooshort;
m_freem(m);
return;
}
if (((m->m_flags & M_EXT) && (ip->ip_src.s_addr & IN_CLASSA_NET) == 0)
|| m->m_len < minlen) {
if ((m = m_pullup(m, minlen)) == 0) {
++igmpstat.igps_rcv_tooshort;
return;
}
ip = mtod(m, struct ip *);
}
/*
* Validate checksum
*/
m->m_data += iphlen;
m->m_len -= iphlen;
igmp = mtod(m, struct igmp *);
if (in_cksum(m, ip->ip_len - iphlen)) {
++igmpstat.igps_rcv_badsum;
m_freem(m);
return;
}
m->m_data -= iphlen;
m->m_len += iphlen;
switch (igmp->igmp_type) {
case IGMP_HOST_MEMBERSHIP_QUERY:
++igmpstat.igps_rcv_queries;
if (ifp->if_flags & IFF_LOOPBACK)
break;
if (igmp->igmp_code == 0) {
rti = rti_find(ifp);
rti->rti_type = IGMP_v1_ROUTER;
rti->rti_age = 0;
if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) {
++igmpstat.igps_rcv_badqueries;
m_freem(m);
return;
}
/*
* 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).
*/
IN_FIRST_MULTI(step, inm);
while (inm != NULL) {
if (inm->inm_ifp == ifp &&
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;
}
IN_NEXT_MULTI(step, inm);
}
} else {
if (!IN_MULTICAST(ip->ip_dst.s_addr)) {
++igmpstat.igps_rcv_badqueries;
m_freem(m);
return;
}
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.
*/
IN_FIRST_MULTI(step, inm);
while (inm != NULL) {
if (inm->inm_ifp == ifp &&
!IN_LOCAL_GROUP(inm->inm_addr.s_addr) &&
(ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP ||
in_hosteq(ip->ip_dst, inm->inm_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;
}
}
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) ||
!in_hosteq(igmp->igmp_group, ip->ip_dst)) {
++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); /* XXX */
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); /* XXX */
if (ia && in_hosteq(ip->ip_src, ia->ia_addr.sin_addr))
break;
#endif
++igmpstat.igps_rcv_reports;
if (ifp->if_flags & IFF_LOOPBACK)
break;
if (!IN_MULTICAST(igmp->igmp_group.s_addr) ||
!in_hosteq(igmp->igmp_group, ip->ip_dst)) {
++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); /* XXX */
#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()
{
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()
{
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 = zeroin_addr;
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 */
ip_output(m, (struct mbuf *)0, (struct route *)0, IP_MULTICASTOPTS,
&imo);
++igmpstat.igps_snd_reports;
}
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