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/* $OpenBSD: mld6.c,v 1.51 2017/04/06 02:11:08 dhill Exp $ */
/* $KAME: mld6.c,v 1.26 2001/02/16 14:50:35 itojun Exp $ */
/*
* Copyright (C) 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.
*/
/*
* 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. 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
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/mld6.h>
#include <netinet6/mld6_var.h>
static struct ip6_pktopts ip6_opts;
static int mld_timers_are_running;
/* XXX: These are necessary for KAME's link-local hack */
static struct in6_addr mld_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
static struct in6_addr mld_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
void mld6_checktimer(struct ifnet *);
static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
void
mld6_init(void)
{
static u_int8_t hbh_buf[8];
struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
mld_timers_are_running = 0;
/* ip6h_nxt will be fill in later */
hbh->ip6h_len = 0; /* (8 >> 3) - 1 */
/* XXX: grotty hard coding... */
hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */
hbh_buf[3] = 0;
hbh_buf[4] = IP6OPT_ROUTER_ALERT;
hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
memcpy(&hbh_buf[6], (caddr_t)&rtalert_code, sizeof(u_int16_t));
ip6_opts.ip6po_hbh = hbh;
}
void
mld6_start_listening(struct in6_multi *in6m)
{
/*
* RFC2710 page 10:
* The node never sends a Report or Done for the link-scope all-nodes
* address.
* MLD messages are never sent for multicast addresses whose scope is 0
* (reserved) or 1 (node-local).
*/
mld_all_nodes_linklocal.s6_addr16[1] = htons(in6m->in6m_ifidx);/* XXX */
if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal) ||
__IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < __IPV6_ADDR_SCOPE_LINKLOCAL) {
in6m->in6m_timer = 0;
in6m->in6m_state = MLD_OTHERLISTENER;
} else {
mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
in6m->in6m_timer =
MLD_RANDOM_DELAY(MLD_V1_MAX_RI *
PR_FASTHZ);
in6m->in6m_state = MLD_IREPORTEDLAST;
mld_timers_are_running = 1;
}
}
void
mld6_stop_listening(struct in6_multi *in6m)
{
mld_all_nodes_linklocal.s6_addr16[1] = htons(in6m->in6m_ifidx);/* XXX */
mld_all_routers_linklocal.s6_addr16[1] =
htons(in6m->in6m_ifidx); /* XXX: necessary when mrouting */
if (in6m->in6m_state == MLD_IREPORTEDLAST &&
(!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal)) &&
__IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > __IPV6_ADDR_SCOPE_INTFACELOCAL)
mld6_sendpkt(in6m, MLD_LISTENER_DONE,
&mld_all_routers_linklocal);
}
void
mld6_input(struct mbuf *m, int off)
{
struct ip6_hdr *ip6;
struct mld_hdr *mldh;
struct ifnet *ifp;
struct in6_multi *in6m;
struct ifmaddr *ifma;
int timer; /* timer value in the MLD query header */
IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
if (mldh == NULL) {
icmp6stat_inc(icp6s_tooshort);
return;
}
/* source address validation */
ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */
if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
#if 0
char src[INET6_ADDRSTRLEN], grp[INET6_ADDRSTRLEN];
log(LOG_ERR,
"mld_input: src %s is not link-local (grp=%s)\n",
inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)),
inet_ntop(AF_INET6, &mldh->mld_addr, grp, sizeof(grp)));
#endif
/*
* spec (RFC2710) does not explicitly
* specify to discard the packet from a non link-local
* source address. But we believe it's expected to do so.
*/
m_freem(m);
return;
}
ifp = if_get(m->m_pkthdr.ph_ifidx);
if (ifp == NULL) {
m_freem(m);
return;
}
/*
* In the MLD6 specification, there are 3 states and a flag.
*
* In Non-Listener state, we simply don't have a membership record.
* In Delaying Listener state, our timer is running (in6m->in6m_timer)
* In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
*
* The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if
* we have heard a report from another member, or MLD_IREPORTEDLAST
* if we sent the last report.
*/
switch(mldh->mld_type) {
case MLD_LISTENER_QUERY:
if (ifp->if_flags & IFF_LOOPBACK)
break;
if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
break; /* print error or log stat? */
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] =
htons(ifp->if_index); /* XXX */
/*
* - 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-nodes" group (ff02::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.
*/
/*
* XXX: System timer resolution is too low to handle Max
* Response Delay, so set 1 to the internal timer even if
* the calculated value equals to zero when Max Response
* Delay is positive.
*/
timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE;
if (timer == 0 && mldh->mld_maxdelay)
timer = 1;
mld_all_nodes_linklocal.s6_addr16[1] =
htons(ifp->if_index); /* XXX */
TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) {
if (ifma->ifma_addr->sa_family != AF_INET6)
continue;
in6m = ifmatoin6m(ifma);
if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
&mld_all_nodes_linklocal) ||
__IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
__IPV6_ADDR_SCOPE_LINKLOCAL)
continue;
if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) ||
IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
&in6m->in6m_addr))
{
if (timer == 0) {
/* send a report immediately */
mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
NULL);
in6m->in6m_timer = 0; /* reset timer */
in6m->in6m_state = MLD_IREPORTEDLAST;
} else if (in6m->in6m_timer == 0 || /* idle */
in6m->in6m_timer > timer) {
in6m->in6m_timer =
MLD_RANDOM_DELAY(timer);
mld_timers_are_running = 1;
}
}
}
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
break;
case MLD_LISTENER_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.
* Note that it is impossible to check IFF_LOOPBACK flag of
* ifp for this purpose, since ip6_mloopback pass the physical
* interface to if_input_local().
*/
if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
break;
if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
break;
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] =
htons(ifp->if_index); /* XXX */
/*
* If we belong to the group being reported, stop
* our timer for that group.
*/
IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m);
if (in6m) {
in6m->in6m_timer = 0; /* transit to idle state */
in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */
}
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
break;
default: /* this is impossible */
#if 0
/*
* this case should be impossible because of filtering in
* icmp6_input(). But we explicitly disabled this part
* just in case.
*/
log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld_type);
#endif
break;
}
if_put(ifp);
m_freem(m);
}
void
mld6_fasttimeo(void)
{
struct ifnet *ifp;
/*
* Quick check to see if any work needs to be done, in order
* to minimize the overhead of fasttimo processing.
*/
if (!mld_timers_are_running)
return;
mld_timers_are_running = 0;
TAILQ_FOREACH(ifp, &ifnet, if_list)
mld6_checktimer(ifp);
}
void
mld6_checktimer(struct ifnet *ifp)
{
struct in6_multi *in6m;
struct ifmaddr *ifma;
splsoftassert(IPL_SOFTNET);
TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) {
if (ifma->ifma_addr->sa_family != AF_INET6)
continue;
in6m = ifmatoin6m(ifma);
if (in6m->in6m_timer == 0) {
/* do nothing */
} else if (--in6m->in6m_timer == 0) {
mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
in6m->in6m_state = MLD_IREPORTEDLAST;
} else {
mld_timers_are_running = 1;
}
}
}
static void
mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst)
{
struct mbuf *mh, *md;
struct mld_hdr *mldh;
struct ip6_hdr *ip6;
struct ip6_moptions im6o;
struct in6_ifaddr *ia6;
struct ifnet *ifp;
int ignflags;
ifp = if_get(in6m->in6m_ifidx);
if (ifp == NULL)
return;
/*
* At first, find a link local address on the outgoing interface
* to use as the source address of the MLD packet.
* We do not reject tentative addresses for MLD report to deal with
* the case where we first join a link-local address.
*/
ignflags = IN6_IFF_DUPLICATED|IN6_IFF_ANYCAST;
if ((ia6 = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) {
if_put(ifp);
return;
}
if ((ia6->ia6_flags & IN6_IFF_TENTATIVE))
ia6 = NULL;
/*
* Allocate mbufs to store ip6 header and MLD header.
* We allocate 2 mbufs and make chain in advance because
* it is more convenient when inserting the hop-by-hop option later.
*/
MGETHDR(mh, M_DONTWAIT, MT_HEADER);
if (mh == NULL) {
if_put(ifp);
return;
}
MGET(md, M_DONTWAIT, MT_DATA);
if (md == NULL) {
m_free(mh);
if_put(ifp);
return;
}
mh->m_next = md;
mh->m_pkthdr.ph_ifidx = 0;
mh->m_pkthdr.ph_rtableid = ifp->if_rdomain;
mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
mh->m_len = sizeof(struct ip6_hdr);
MH_ALIGN(mh, sizeof(struct ip6_hdr));
/* fill in the ip6 header */
ip6 = mtod(mh, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
/* ip6_plen will be set later */
ip6->ip6_nxt = IPPROTO_ICMPV6;
/* ip6_hlim will be set by im6o.im6o_hlim */
ip6->ip6_src = ia6 ? ia6->ia_addr.sin6_addr : in6addr_any;
ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
/* fill in the MLD header */
md->m_len = sizeof(struct mld_hdr);
mldh = mtod(md, struct mld_hdr *);
mldh->mld_type = type;
mldh->mld_code = 0;
mldh->mld_cksum = 0;
/* XXX: we assume the function will not be called for query messages */
mldh->mld_maxdelay = 0;
mldh->mld_reserved = 0;
mldh->mld_addr = in6m->in6m_addr;
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
mh->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT;
/* construct multicast option */
bzero(&im6o, sizeof(im6o));
im6o.im6o_ifidx = ifp->if_index;
im6o.im6o_hlim = 1;
if_put(ifp);
/*
* Request loopback of the report if we are acting as a multicast
* router, so that the process-level routing daemon can hear it.
*/
#ifdef MROUTING
im6o.im6o_loop = (ip6_mrouter != NULL);
#endif
icmp6stat_inc(icp6s_outhist + type);
ip6_output(mh, &ip6_opts, NULL, ia6 ? 0 : IPV6_UNSPECSRC, &im6o,
NULL);
}
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