NetBSD/sys/netinet/igmp.c
itojun 04ac848d6f introduce m->m_pkthdr.aux to hold random data which needs to be passed
between protocol handlers.

ipsec socket pointers, ipsec decryption/auth information, tunnel
decapsulation information are in my mind - there can be several other usage.
at this moment, we use this for ipsec socket pointer passing.  this will
avoid reuse of m->m_pkthdr.rcvif in ipsec code.

due to the change, MHLEN will be decreased by sizeof(void *) - for example,
for i386, MHLEN was 100 bytes, but is now 96 bytes.
we may want to increase MSIZE from 128 to 256 for some of our architectures.

take caution if you use it for keeping some data item for long period
of time - use extra caution on M_PREPEND() or m_adj(), as they may result
in loss of m->m_pkthdr.aux pointer (and mbuf leak).

this will bump kernel version.

(as discussed in tech-net, tested in kame tree)
2000-03-01 12:49:27 +00:00

562 lines
14 KiB
C

/* $NetBSD: igmp.c,v 1.23 2000/03/01 12:49:30 itojun 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;
{
register 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;
{
register 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;
register int iphlen;
register struct ifnet *ifp = m->m_pkthdr.rcvif;
register struct ip *ip = mtod(m, struct ip *);
register struct igmp *igmp;
register int minlen;
struct in_multi *inm;
struct in_multistep step;
struct router_info *rti;
register 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 || 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, ip->ip_len - iphlen)) {
++igmpstat.igps_rcv_badsum;
m_freem(m);
return;
}
m->m_data -= iphlen;
m->m_len += iphlen;
ip = mtod(m, struct ip *);
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()
{
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 = 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()
{
register 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;
}