808a36ef65
This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise.
480 lines
13 KiB
C
480 lines
13 KiB
C
/*
|
|
* 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
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* 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.
|
|
* Modified to fully comply to IGMPv2 by Bill Fenner, Oct 1995.
|
|
*
|
|
* MULTICAST Revision: 3.5.1.4
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/protosw.h>
|
|
#include <sys/kernel.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>
|
|
|
|
static struct router_info *
|
|
find_rti __P((struct ifnet *ifp));
|
|
|
|
static struct igmpstat igmpstat;
|
|
|
|
SYSCTL_STRUCT(_net_inet_igmp, IGMPCTL_STATS, stats, CTLFLAG_RD,
|
|
&igmpstat, igmpstat, "");
|
|
|
|
static int igmp_timers_are_running;
|
|
static u_long igmp_all_hosts_group;
|
|
static u_long igmp_all_rtrs_group;
|
|
static struct mbuf *router_alert;
|
|
static struct router_info *Head;
|
|
|
|
static void igmp_sendpkt(struct in_multi *, int, unsigned long);
|
|
|
|
void
|
|
igmp_init()
|
|
{
|
|
struct ipoption *ra;
|
|
|
|
/*
|
|
* To avoid byte-swapping the same value over and over again.
|
|
*/
|
|
igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
|
|
igmp_all_rtrs_group = htonl(INADDR_ALLRTRS_GROUP);
|
|
|
|
igmp_timers_are_running = 0;
|
|
|
|
/*
|
|
* Construct a Router Alert option to use in outgoing packets
|
|
*/
|
|
MGET(router_alert, M_DONTWAIT, MT_DATA);
|
|
ra = mtod(router_alert, struct ipoption *);
|
|
ra->ipopt_dst.s_addr = 0;
|
|
ra->ipopt_list[0] = IPOPT_RA; /* Router Alert Option */
|
|
ra->ipopt_list[1] = 0x04; /* 4 bytes long */
|
|
ra->ipopt_list[2] = 0x00;
|
|
ra->ipopt_list[3] = 0x00;
|
|
router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1];
|
|
|
|
Head = (struct router_info *) 0;
|
|
}
|
|
|
|
static 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->rti_ifp == ifp) {
|
|
#ifdef IGMP_DEBUG
|
|
printf("[igmp.c, _find_rti] --> found old entry \n");
|
|
#endif
|
|
return rti;
|
|
}
|
|
rti = rti->rti_next;
|
|
}
|
|
MALLOC(rti, struct router_info *, sizeof *rti, M_MRTABLE, M_NOWAIT);
|
|
rti->rti_ifp = ifp;
|
|
rti->rti_type = IGMP_V2_ROUTER;
|
|
rti->rti_time = 0;
|
|
rti->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);
|
|
|
|
/*
|
|
* In the IGMPv2 specification, there are 3 states and a flag.
|
|
*
|
|
* In Non-Member state, we simply don't have a membership record.
|
|
* In Delaying Member state, our timer is running (inm->inm_timer)
|
|
* In Idle Member state, our timer is not running (inm->inm_timer==0)
|
|
*
|
|
* The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
|
|
* we have heard a report from another member, or IGMP_IREPORTEDLAST
|
|
* if I sent the last report.
|
|
*/
|
|
switch (igmp->igmp_type) {
|
|
|
|
case IGMP_MEMBERSHIP_QUERY:
|
|
++igmpstat.igps_rcv_queries;
|
|
|
|
if (ifp->if_flags & IFF_LOOPBACK)
|
|
break;
|
|
|
|
if (igmp->igmp_code == 0) {
|
|
/*
|
|
* Old router. Remember that the querier on this
|
|
* interface is old, and set the timer to the
|
|
* value in RFC 1112.
|
|
*/
|
|
|
|
rti->rti_type = IGMP_V1_ROUTER;
|
|
rti->rti_time = 0;
|
|
|
|
timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;
|
|
|
|
if (ip->ip_dst.s_addr != igmp_all_hosts_group ||
|
|
igmp->igmp_group.s_addr != 0) {
|
|
++igmpstat.igps_rcv_badqueries;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
} else {
|
|
/*
|
|
* New router. Simply do the new validity check.
|
|
*/
|
|
|
|
if (igmp->igmp_group.s_addr != 0 &&
|
|
!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
|
|
++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 the "all-hosts" group (224.0.0.1).
|
|
* - Restart any timer that is already running but has
|
|
* a value longer than the requested timeout.
|
|
* - Use the value specified in the query message as
|
|
* the maximum timeout.
|
|
*/
|
|
IN_FIRST_MULTI(step, inm);
|
|
while (inm != NULL) {
|
|
if (inm->inm_ifp == ifp &&
|
|
inm->inm_addr.s_addr != igmp_all_hosts_group &&
|
|
(igmp->igmp_group.s_addr == 0 ||
|
|
igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
|
|
if (inm->inm_timer == 0 ||
|
|
inm->inm_timer > timer) {
|
|
inm->inm_timer =
|
|
IGMP_RANDOM_DELAY(timer);
|
|
igmp_timers_are_running = 1;
|
|
}
|
|
}
|
|
IN_NEXT_MULTI(step, inm);
|
|
}
|
|
|
|
break;
|
|
|
|
case IGMP_V1_MEMBERSHIP_REPORT:
|
|
case IGMP_V2_MEMBERSHIP_REPORT:
|
|
/*
|
|
* For fast leave to work, we have to know that we are the
|
|
* last person to send a report for this group. Reports
|
|
* can potentially get looped back if we are a multicast
|
|
* router, so discard reports sourced by me.
|
|
*/
|
|
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))) {
|
|
++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)
|
|
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;
|
|
|
|
inm->inm_state = IGMP_OTHERMEMBER;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Pass all valid IGMP packets up to any process(es) listening
|
|
* on a raw IGMP socket.
|
|
*/
|
|
rip_input(m, iphlen);
|
|
}
|
|
|
|
void
|
|
igmp_joingroup(inm)
|
|
struct in_multi *inm;
|
|
{
|
|
int s = splnet();
|
|
|
|
if (inm->inm_addr.s_addr == igmp_all_hosts_group
|
|
|| inm->inm_ifp->if_flags & IFF_LOOPBACK) {
|
|
inm->inm_timer = 0;
|
|
inm->inm_state = IGMP_OTHERMEMBER;
|
|
} else {
|
|
inm->inm_rti = find_rti(inm->inm_ifp);
|
|
igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
|
|
inm->inm_timer = IGMP_RANDOM_DELAY(
|
|
IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
|
|
inm->inm_state = IGMP_IREPORTEDLAST;
|
|
igmp_timers_are_running = 1;
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
void
|
|
igmp_leavegroup(inm)
|
|
struct in_multi *inm;
|
|
{
|
|
if (inm->inm_state == IGMP_IREPORTEDLAST &&
|
|
inm->inm_addr.s_addr != igmp_all_hosts_group &&
|
|
!(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
|
|
inm->inm_rti->rti_type != IGMP_V1_ROUTER)
|
|
igmp_sendpkt(inm, IGMP_V2_LEAVE_GROUP, igmp_all_rtrs_group);
|
|
}
|
|
|
|
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) {
|
|
igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
|
|
inm->inm_state = IGMP_IREPORTEDLAST;
|
|
} 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) {
|
|
if (rti->rti_type == IGMP_V1_ROUTER) {
|
|
rti->rti_time++;
|
|
if (rti->rti_time >= IGMP_AGE_THRESHOLD) {
|
|
rti->rti_type = IGMP_V2_ROUTER;
|
|
}
|
|
}
|
|
rti = rti->rti_next;
|
|
}
|
|
#ifdef IGMP_DEBUG
|
|
printf("[igmp.c,_slowtimo] -- > exiting \n");
|
|
#endif
|
|
splx(s);
|
|
}
|
|
|
|
static struct route igmprt;
|
|
|
|
static void
|
|
igmp_sendpkt(inm, type, addr)
|
|
struct in_multi *inm;
|
|
int type;
|
|
unsigned long addr;
|
|
{
|
|
struct mbuf *m;
|
|
struct igmp *igmp;
|
|
struct ip *ip;
|
|
struct ip_moptions imo;
|
|
|
|
MGETHDR(m, M_DONTWAIT, MT_HEADER);
|
|
if (m == NULL)
|
|
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.s_addr = addr ? addr : igmp->igmp_group.s_addr;
|
|
|
|
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);
|
|
|
|
/*
|
|
* XXX
|
|
* Do we have to worry about reentrancy here? Don't think so.
|
|
*/
|
|
ip_output(m, router_alert, &igmprt, 0, &imo);
|
|
|
|
++igmpstat.igps_snd_reports;
|
|
}
|