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freebsd/sys/netinet/igmp.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 1.5 1994/09/14 03:10:07 wollman 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) {
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 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.
*/
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);
}
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