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HardenedBSD/sys/netinet/igmp.c
Garrett Wollman f0068c4a70 Initial get-the-easy-case-working upgrade of the multicast code 
to something more recent than the ancient 1.2 release contained in
4.4.  This code has the following advantages as compared to
previous versions (culled from the README file for the SunOS release):

- True multicast delivery
- Configurable rate-limiting of forwarded multicast traffic on each
  physical interface or tunnel, using a token-bucket limiter.
- Simplistic classification of packets for prioritized dropping.
- Administrative scoping of multicast address ranges.
- Faster detection of hosts leaving groups.
- Support for multicast traceroute (code not yet available).
- Support for RSVP, the Resource Reservation Protocol.

What still needs to be done:

- The multicast forwarder needs testing.
- The multicast routing daemon needs to be ported.
- Network interface drivers need to have the `#ifdef MULTICAST' goop ripped
  out of them.
- The IGMP code should probably be bogon-tested.

Some notes about the porting process:

In some cases, the Berkeley people decided to incorporate functionality from
later releases of the multicast code, but then had to do things differently.
As a result, if you look at Deering's patches, and then look at
our code, it is not always obvious whether the patch even applies.  Let
the reader beware.

I ran ip_mroute.c through several passes of `unifdef' to get rid of
useless grot, and to permanently enable the RSVP support, which we will
include as standard.

Ported by: 	Garrett Wollman
Submitted by:	Steve Deering and Ajit Thyagarajan (among others)
1994-09-06 22:42:31 +00:00

629 lines
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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 1.3 1994/08/02 07:48:04 davidg Exp $
*/
/*
* Internet Group Management Protocol (IGMP) routines.
*
* Written by Steve Deering, Stanford, May 1988.
* Modified by Rosen Sharma, Stanford, Aug 1994.
*
* MULTICAST 1.4
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.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>
extern struct ifnet loif;
struct igmpstat igmpstat;
static int igmp_timers_are_running = 0;
static u_long igmp_all_hosts_group;
static struct router_info *Head = 0;
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);
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){ /* ? is it ok to compare */
/* pointers */
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){ /* ? is it ok to compare pointers */
#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;
static 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 = ntohs(igmp->igmp_code);
rti = find_rti(ifp);
switch (igmp->igmp_type) {
case IGMP_HOST_MEMBERSHIP_QUERY:
++igmpstat.igps_rcv_queries;
if (ifp == &loif)
break;
if (igmp->igmp_code == 0) {
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 the
* "all-hosts" group.
*/
IN_FIRST_MULTI(step, inm);
while (inm != NULL) {
if (inm->inm_ifp == ifp
&& inm->inm_timer == 0
&& inm->inm_addr.s_addr
!= igmp_all_hosts_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 (ip->ip_dst.s_addr != igmp_all_hosts_group) {
if (!(m->m_flags & M_MCAST)) {
++igmpstat.igps_rcv_badqueries;
m_freem(m);
return;
}
}
if (ip->ip_dst.s_addr == igmp_all_hosts_group) {
/*
* - Start the timers in all of our membership records
* for the interface on which the query arrived
* excl. those that belong to the "all-hosts" group.
* - For timers already running check if they need to
* be reset.
* - Use the igmp->igmp_code filed as the maximum
* delay possible
*/
IN_FIRST_MULTI(step, inm);
while (inm != NULL){
switch(inm->inm_state){
case IGMP_IDLE_MEMBER:
case IGMP_LAZY_MEMBER:
case IGMP_AWAKENING_MEMBER:
if (inm->inm_ifp == ifp &&
inm->inm_addr.s_addr !=
igmp_all_hosts_group) {
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_ifp == ifp &&
(inm->inm_timer >
timer * PR_FASTHZ / IGMP_TIMER_SCALE)
&&
inm->inm_addr.s_addr !=
igmp_all_hosts_group) {
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);
}
} else {
/*
** group specific query
*/
IN_FIRST_MULTI(step, inm);
while (inm != NULL) {
if (inm->inm_addr.s_addr == ip->ip_dst.s_addr) {
switch(inm->inm_state ){
case IGMP_IDLE_MEMBER:
case IGMP_LAZY_MEMBER:
case IGMP_AWAKENING_MEMBER:
inm->inm_state = IGMP_DELAYING_MEMBER;
if (inm->inm_ifp == ifp ) {
inm->inm_timer = IGMP_RANDOM_DELAY(timer);
igmp_timers_are_running = 1;
inm->inm_state = IGMP_DELAYING_MEMBER;
}
break;
case IGMP_DELAYING_MEMBER:
inm->inm_state = IGMP_DELAYING_MEMBER;
if (inm->inm_ifp == ifp &&
(inm->inm_timer >
timer * PR_FASTHZ / IGMP_TIMER_SCALE) ) {
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:
++igmpstat.igps_rcv_reports;
if (ifp == &loif)
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;
}
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:
/** check this out - this was if (oldrouter) **/
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:
/*
* an new report
*/
++igmpstat.igps_rcv_reports;
if (ifp == &loif)
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_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;
{
register int s = splnet();
inm->inm_state = IGMP_IDLE_MEMBER;
if (inm->inm_addr.s_addr == igmp_all_hosts_group ||
inm->inm_ifp == &loif)
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;
{
/*
* No action required on leaving a group.
*/
switch(inm->inm_state){
case IGMP_DELAYING_MEMBER:
case IGMP_IDLE_MEMBER:
if (!(inm->inm_addr.s_addr == igmp_all_hosts_group ||
inm->inm_ifp == &loif))
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;
register int s;
struct in_multistep step;
/*
* 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;
/*
* 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
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);
}
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