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HardenedBSD/sys/netinet/igmp.c
Garrett Wollman 1c5de19afb Kernel side of 3.5 multicast routing code, based on work by Bill Fenner 
and other work done here.  The LKM support is probably broken, but it
still compiles and will be fixed later.
1995-06-13 17:51:16 +00:00

628 lines
16 KiB
C
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/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 8.1 (Berkeley) 7/19/93
* $Id: igmp.c,v 1.10 1995/05/16 01:28:29 davidg Exp $
*/
/*
* 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: 3.3.1.2
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/proc.h> /* XXX needed for sysctl.h */
#include <vm/vm.h> /* XXX needed for sysctl.h */
#include <sys/sysctl.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>
struct igmpstat igmpstat;
static int igmp_timers_are_running;
static u_long igmp_all_hosts_group;
static u_long igmp_local_group;
static u_long igmp_local_group_mask;
static struct router_info *Head;
static void igmp_sendpkt(struct in_multi *, int);
static void igmp_sendleave(struct in_multi *);
void
igmp_init()
{
/*
* To avoid byte-swapping the same value over and over again.
*/
igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
igmp_local_group = htonl(0xe0000000); /* 224.0.0.0 */
igmp_local_group_mask = htonl(0xffffff00); /* ........^ */
igmp_timers_are_running = 0;
Head = (struct router_info *) 0;
}
int
fill_rti(inm)
struct in_multi *inm;
{
register struct router_info *rti = Head;
#ifdef IGMP_DEBUG
printf("[igmp.c, _fill_rti] --> entering \n");
#endif
while (rti) {
if (rti->ifp == inm->inm_ifp) {
inm->inm_rti = rti;
#ifdef IGMP_DEBUG
printf("[igmp.c, _fill_rti] --> found old entry \n");
#endif
if (rti->type == IGMP_OLD_ROUTER)
return IGMP_HOST_MEMBERSHIP_REPORT;
else
return IGMP_HOST_NEW_MEMBERSHIP_REPORT;
}
rti = rti->next;
}
MALLOC(rti, struct router_info *, sizeof *rti, M_MRTABLE, M_NOWAIT);
rti->ifp = inm->inm_ifp;
rti->type = IGMP_NEW_ROUTER;
rti->time = IGMP_AGE_THRESHOLD;
rti->next = Head;
Head = rti;
inm->inm_rti = rti;
#ifdef IGMP_DEBUG
printf("[igmp.c, _fill_rti] --> created new entry \n");
#endif
return IGMP_HOST_NEW_MEMBERSHIP_REPORT;
}
struct router_info *
find_rti(ifp)
struct ifnet *ifp;
{
register struct router_info *rti = Head;
#ifdef IGMP_DEBUG
printf("[igmp.c, _find_rti] --> entering \n");
#endif
while (rti) {
if (rti->ifp == ifp) {
#ifdef IGMP_DEBUG
printf("[igmp.c, _find_rti] --> found old entry \n");
#endif
return rti;
}
rti = rti->next;
}
MALLOC(rti, struct router_info *, sizeof *rti, M_MRTABLE, M_NOWAIT);
rti->ifp = ifp;
rti->type = IGMP_NEW_ROUTER;
rti->time = IGMP_AGE_THRESHOLD;
rti->next = Head;
Head = rti;
#ifdef IGMP_DEBUG
printf("[igmp.c, _find_rti] --> created an entry \n");
#endif
return rti;
}
void
igmp_input(m, iphlen)
register struct mbuf *m;
register 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);
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->type = IGMP_OLD_ROUTER; rti->time = 0;
/*
** Do exactly as RFC 1112 says
*/
if (ip->ip_dst.s_addr != igmp_all_hosts_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
&& ((inm->inm_addr.s_addr
& igmp_local_group_mask)
!= igmp_local_group)) {
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 {
/*
** New Router
*/
if (!(m->m_flags & M_MCAST)) {
++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 a "local" group (224.0.0.X)
* - For timers already running check if they need to
* be reset.
* - Use the igmp->igmp_code field as the maximum
* delay possible
*/
IN_FIRST_MULTI(step, inm);
while (inm != NULL) {
if (inm->inm_ifp == ifp &&
(inm->inm_addr.s_addr & igmp_local_group_mask) !=
igmp_local_group &&
(ip->ip_dst.s_addr == igmp_all_hosts_group ||
ip->ip_dst.s_addr == inm->inm_addr.s_addr)) {
switch(inm->inm_state) {
case IGMP_IDLE_MEMBER:
case IGMP_LAZY_MEMBER:
case IGMP_AWAKENING_MEMBER:
inm->inm_timer = IGMP_RANDOM_DELAY(timer);
igmp_timers_are_running = 1;
inm->inm_state = IGMP_DELAYING_MEMBER;
break;
case IGMP_DELAYING_MEMBER:
if (inm->inm_timer > timer) {
inm->inm_timer = IGMP_RANDOM_DELAY(timer);
igmp_timers_are_running = 1;
inm->inm_state = IGMP_DELAYING_MEMBER;
}
break;
case IGMP_SLEEPING_MEMBER:
inm->inm_state = IGMP_AWAKENING_MEMBER;
break;
}
}
IN_NEXT_MULTI(step, inm);
}
}
break;
case IGMP_HOST_MEMBERSHIP_REPORT:
/*
* an old report
*/
++igmpstat.igps_rcv_reports;
if (ifp->if_flags & IFF_LOOPBACK)
break;
if (!IN_MULTICAST(ntohl(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 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) {
IFP_TO_IA(ifp, ia);
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;
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->type == IGMP_OLD_ROUTER)
inm->inm_state = IGMP_LAZY_MEMBER;
else
inm->inm_state = IGMP_SLEEPING_MEMBER;
break;
}
}
break;
case IGMP_HOST_NEW_MEMBERSHIP_REPORT:
/*
* a new report
*/
/*
* We can get confused and think there's someone
* else out there if we are a multicast router.
* For fast leave to work, we have to know that
* we are the only member.
*/
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)) ||
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 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) {
/* #ifndef MROUTING XXX - I don't think the ifdef is necessary */
IFP_TO_IA(ifp, ia);
/* #endif */
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;
switch(inm->inm_state){
case IGMP_DELAYING_MEMBER:
case IGMP_IDLE_MEMBER:
inm->inm_state = IGMP_LAZY_MEMBER;
break;
case IGMP_AWAKENING_MEMBER:
inm->inm_state = IGMP_LAZY_MEMBER;
break;
case IGMP_LAZY_MEMBER:
case IGMP_SLEEPING_MEMBER:
break;
}
}
}
/*
* Pass all valid IGMP packets up to any process(es) listening
* on a raw IGMP socket.
*/
rip_input(m);
}
void
igmp_joingroup(inm)
struct in_multi *inm;
{
int s = splnet();
inm->inm_state = IGMP_IDLE_MEMBER;
if ((inm->inm_addr.s_addr & igmp_local_group_mask) == igmp_local_group
|| inm->inm_ifp->if_flags & IFF_LOOPBACK)
inm->inm_timer = 0;
else {
igmp_sendpkt(inm,fill_rti(inm));
inm->inm_timer = IGMP_RANDOM_DELAY(
IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
inm->inm_state = IGMP_DELAYING_MEMBER;
igmp_timers_are_running = 1;
}
splx(s);
}
void
igmp_leavegroup(inm)
struct in_multi *inm;
{
switch(inm->inm_state) {
case IGMP_DELAYING_MEMBER:
case IGMP_IDLE_MEMBER:
if (((inm->inm_addr.s_addr & igmp_local_group_mask)
!= igmp_local_group)
&& !(inm->inm_ifp->if_flags & IFF_LOOPBACK))
if (inm->inm_rti->type != IGMP_OLD_ROUTER)
igmp_sendleave(inm);
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 = splnet();
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->type == IGMP_OLD_ROUTER)
igmp_sendpkt(inm, IGMP_HOST_MEMBERSHIP_REPORT);
else
igmp_sendpkt(inm, IGMP_HOST_NEW_MEMBERSHIP_REPORT);
inm->inm_state = IGMP_IDLE_MEMBER;
}
} else {
igmp_timers_are_running = 1;
}
IN_NEXT_MULTI(step, inm);
}
splx(s);
}
void
igmp_slowtimo()
{
int s = splnet();
register struct router_info *rti = Head;
#ifdef IGMP_DEBUG
printf("[igmp.c,_slowtimo] -- > entering \n");
#endif
while (rti) {
rti->time ++;
if (rti->time >= IGMP_AGE_THRESHOLD){
rti->type = IGMP_NEW_ROUTER;
rti->time = IGMP_AGE_THRESHOLD;
}
rti = rti->next;
}
#ifdef IGMP_DEBUG
printf("[igmp.c,_slowtimo] -- > exiting \n");
#endif
splx(s);
}
static void
igmp_sendpkt(inm, type)
struct in_multi *inm;
int type;
{
struct mbuf *m;
struct igmp *igmp;
struct ip *ip;
struct ip_moptions *imo;
MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m == NULL)
return;
MALLOC(imo, struct ip_moptions *, sizeof *imo, M_IPMOPTS, M_DONTWAIT);
if (!imo) {
m_free(m);
return;
}
m->m_pkthdr.rcvif = loif;
m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip));
m->m_data += sizeof(struct ip);
m->m_len = IGMP_MINLEN;
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);
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 = igmp->igmp_group;
imo->imo_multicast_ifp = inm->inm_ifp;
imo->imo_multicast_ttl = 1;
imo->imo_multicast_vif = -1;
/*
* Request loopback of the report if we are acting as a multicast
* router, so that the process-level routing demon can hear it.
*/
imo->imo_multicast_loop = (ip_mrouter != NULL);
ip_output(m, (struct mbuf *)0, (struct route *)0, 0, imo);
FREE(imo, M_IPMOPTS);
++igmpstat.igps_snd_reports;
}
static void
igmp_sendleave(inm)
struct in_multi *inm;
{
igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE);
}
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; /* XXX overloaded */
switch(name[0]) {
case IGMPCTL_STATS:
return sysctl_rdstruct(oldp, oldlenp, newp, &igmpstat,
sizeof igmpstat);
default:
return ENOPROTOOPT;
}
}
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