[apple/xnu.git] / bsd / netinet6 / mld6.c

/*	$FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.2 2001/07/03 11:01:54 ume Exp $	*/
/*	$KAME: mld6.c,v 1.27 2001/04/04 05:17:30 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. 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
 */


#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 <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/mld6_var.h>

#include <net/net_osdep.h>

/*
 * Protocol constants
 */

/* denotes that the MLD max response delay field specifies time in milliseconds */
#define MLD6_TIMER_SCALE	1000
/*
 * time between repetitions of a node's initial report of interest in a
 * multicast address(in seconds)
 */
#define MLD6_UNSOLICITED_REPORT_INTERVAL	10

extern lck_mtx_t *nd6_mutex;
static struct ip6_pktopts ip6_opts;
static int mld6_timers_are_running;
static int mld6_init_done = 0 ;
/* XXX: These are necessary for KAME's link-local hack */
static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;

static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);

void
mld6_init()
{
	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);

	if (mld6_init_done)
		return;

	mld6_init_done = 1;
	mld6_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_RTALERT;
	hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
	bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));

	init_ip6pktopts(&ip6_opts);
	ip6_opts.ip6po_hbh = hbh;
}

void
mld6_start_listening(
	struct in6_multi *in6m)
{
	int s = splnet();

	/*
	 * 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).
	 */
	mld6_all_nodes_linklocal.s6_addr16[1] =
		htons(in6m->in6m_ifp->if_index); /* XXX */
	if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
	    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
		in6m->in6m_timer = 0;
		in6m->in6m_state = MLD6_OTHERLISTENER;
	} else {
		mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
		in6m->in6m_timer = MLD6_RANDOM_DELAY(
			MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
		in6m->in6m_state = MLD6_IREPORTEDLAST;
		mld6_timers_are_running = 1;
	}
	splx(s);
}

void
mld6_stop_listening(
	struct in6_multi *in6m)
{
	mld6_all_nodes_linklocal.s6_addr16[1] =
		htons(in6m->in6m_ifp->if_index); /* XXX */
	mld6_all_routers_linklocal.s6_addr16[1] =
		htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */

	if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
	    (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
	    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
		mld6_sendpkt(in6m, MLD6_LISTENER_DONE,
			     &mld6_all_routers_linklocal);
}

void
mld6_input(
	struct mbuf *m,
	int off)
{
	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
	struct mld6_hdr *mldh;
	struct ifnet *ifp = m->m_pkthdr.rcvif;
	struct in6_multi *in6m;
	struct in6_ifaddr *ia;
	struct ifmultiaddr *ifma;
	int timer;		/* timer value in the MLD query header */

#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(*mldh), return);
	mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off);
#else
	IP6_EXTHDR_GET(mldh, struct mld6_hdr *, m, off, sizeof(*mldh));
	if (mldh == NULL) {
		icmp6stat.icp6s_tooshort++;
		return;
	}
#endif

	/* source address validation */
	ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */
	if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
		log(LOG_ERR,
		    "mld6_input: src %s is not link-local (grp=%s)\n",
		    ip6_sprintf(&ip6->ip6_src),
		    ip6_sprintf(&mldh->mld6_addr));
		/*
		 * 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.
		 * XXX: do we have to allow :: as source?
		 */
		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 MLD6_OTHERLISTENER if
	 * we have heard a report from another member, or MLD6_IREPORTEDLAST
	 * if we sent the last report.
	 */
	switch(mldh->mld6_type) {
	case MLD6_LISTENER_QUERY:
		if (ifp->if_flags & IFF_LOOPBACK)
			break;

		if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) &&
		    !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
			break;	/* print error or log stat? */
		if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
			mldh->mld6_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.
		 */
		ifnet_lock_exclusive(ifp);
		IFP_TO_IA6(ifp, ia);
		if (ia == NULL)
			break;

		/*
		 * 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->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
		if (timer == 0 && mldh->mld6_maxdelay)
			timer = 1;
		mld6_all_nodes_linklocal.s6_addr16[1] =
			htons(ifp->if_index); /* XXX */
		
		LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
		{
			if (ifma->ifma_addr->sa_family != AF_INET6)
				continue;
			in6m = (struct in6_multi *)ifma->ifma_protospec;
			if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
					&mld6_all_nodes_linklocal) ||
			    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
			    IPV6_ADDR_SCOPE_LINKLOCAL)
				continue;

			if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) ||
			    IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr,
						&in6m->in6m_addr))
			{
				if (timer == 0) {
					/* send a report immediately */
					mld6_sendpkt(in6m, MLD6_LISTENER_REPORT,
						NULL);
					in6m->in6m_timer = 0; /* reset timer */
					in6m->in6m_state = MLD6_IREPORTEDLAST;
				}
				else if (in6m->in6m_timer == 0 || /*idle state*/
					in6m->in6m_timer > timer) {
					in6m->in6m_timer =
						MLD6_RANDOM_DELAY(timer);
					mld6_timers_are_running = 1;
				}
			}
		}
		ifnet_lock_done(ifp);

		if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
			mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
		break;
	case MLD6_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 looutput.
		 */
		if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
			break;

		if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
			break;

		if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
			mldh->mld6_addr.s6_addr16[1] =
				htons(ifp->if_index); /* XXX */
		/*
		 * If we belong to the group being reported, stop
		 * our timer for that group.
		 */
		ifnet_lock_shared(ifp);
		IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m);
		if (in6m) {
			in6m->in6m_timer = 0; /* transit to idle state */
			in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
		}
		ifnet_lock_done(ifp);

		if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
			mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
		break;
	default:		/* this is impossible */
		log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type);
		break;
	}

	m_freem(m);
}

void
mld6_fasttimeo()
{
	struct in6_multi *in6m;
	struct in6_multistep step;

	/*
	 * Quick check to see if any work needs to be done, in order
	 * to minimize the overhead of fasttimo processing.
	 */
	if (!mld6_timers_are_running)
		return;

	lck_mtx_lock(nd6_mutex);
	mld6_timers_are_running = 0;
	IN6_FIRST_MULTI(step, in6m);
	while (in6m != NULL) {
		if (in6m->in6m_timer == 0) {
			/* do nothing */
		} else if (--in6m->in6m_timer == 0) {
			mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
			in6m->in6m_state = MLD6_IREPORTEDLAST;
		} else {
			mld6_timers_are_running = 1;
		}
		IN6_NEXT_MULTI(step, in6m);
	}
	lck_mtx_unlock(nd6_mutex);
}

static void
mld6_sendpkt(
	struct in6_multi *in6m,
	int type,
	const struct in6_addr *dst)
{
	struct mbuf *mh, *md;
	struct mld6_hdr *mldh;
	struct ip6_hdr *ip6;
	struct ip6_moptions im6o;
	struct in6_ifaddr *ia;
	struct ifnet *ifp = in6m->in6m_ifp;
	struct ifnet *outif = NULL;

	/*
	 * At first, find a link local address on the outgoing interface
	 * to use as the source address of the MLD packet.
	 */
	if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
	    == NULL)
		return;

	/*
	 * 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)
		return;
	MGET(md, M_DONTWAIT, MT_DATA);
	if (md == NULL) {
		m_free(mh);
		return;
	}
	mh->m_next = md;

	mh->m_pkthdr.rcvif = NULL;
	mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_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_multicast_hlim */
	ip6->ip6_src = ia->ia_addr.sin6_addr;
	ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;

	/* fill in the MLD header */
	md->m_len = sizeof(struct mld6_hdr);
	mldh = mtod(md, struct mld6_hdr *);
	mldh->mld6_type = type;
	mldh->mld6_code = 0;
	mldh->mld6_cksum = 0;
	/* XXX: we assume the function will not be called for query messages */
	mldh->mld6_maxdelay = 0;
	mldh->mld6_reserved = 0;
	mldh->mld6_addr = in6m->in6m_addr;
	if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
		mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
	mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
				     sizeof(struct mld6_hdr));

	/* construct multicast option */
	bzero(&im6o, sizeof(im6o));
	im6o.im6o_multicast_ifp = ifp;
	im6o.im6o_multicast_hlim = 1;

	/*
	 * Request loopback of the report if we are acting as a multicast
	 * router, so that the process-level routing daemon can hear it.
	 */
	im6o.im6o_multicast_loop = (ip6_mrouter != NULL);

	/* increment output statictics */
	icmp6stat.icp6s_outhist[type]++;

	ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, 0);
	if (outif) {
		icmp6_ifstat_inc(outif, ifs6_out_msg);
		switch (type) {
		case MLD6_LISTENER_QUERY:
			icmp6_ifstat_inc(outif, ifs6_out_mldquery);
			break;
		case MLD6_LISTENER_REPORT:
			icmp6_ifstat_inc(outif, ifs6_out_mldreport);
			break;
		case MLD6_LISTENER_DONE:
			icmp6_ifstat_inc(outif, ifs6_out_mlddone);
			break;
		}
	}
}
Commit	Line	Data
9bccf70c A	1	/* $FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.2 2001/07/03 11:01:54 ume Exp $ */
9bccf70c A	2	/* $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $ */
1c79356b A	3
	4	/*
	5	* Copyright (C) 1998 WIDE Project.
	6	* All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. Neither the name of the project nor the names of its contributors
	17	* may be used to endorse or promote products derived from this software
	18	* without specific prior written permission.
	19	*
	20	* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
	21	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
	24	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	* SUCH DAMAGE.
	31	*/
	32
	33	/*
	34	* Copyright (c) 1988 Stephen Deering.
	35	* Copyright (c) 1992, 1993
	36	* The Regents of the University of California. All rights reserved.
	37	*
	38	* This code is derived from software contributed to Berkeley by
	39	* Stephen Deering of Stanford University.
	40	*
	41	* Redistribution and use in source and binary forms, with or without
	42	* modification, are permitted provided that the following conditions
	43	* are met:
	44	* 1. Redistributions of source code must retain the above copyright
	45	* notice, this list of conditions and the following disclaimer.
	46	* 2. Redistributions in binary form must reproduce the above copyright
	47	* notice, this list of conditions and the following disclaimer in the
	48	* documentation and/or other materials provided with the distribution.
	49	* 3. All advertising materials mentioning features or use of this software
	50	* must display the following acknowledgement:
	51	* This product includes software developed by the University of
	52	* California, Berkeley and its contributors.
	53	* 4. Neither the name of the University nor the names of its contributors
	54	* may be used to endorse or promote products derived from this software
	55	* without specific prior written permission.
	56	*
	57	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	58	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	59	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	60	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	61	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	62	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	63	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	64	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	65	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	66	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67	* SUCH DAMAGE.
68	*
69	* @(#)igmp.c 8.1 (Berkeley) 7/19/93
70	*/
71
1c79356b A	72
	73	#include <sys/param.h>
	74	#include <sys/systm.h>
	75	#include <sys/mbuf.h>
	76	#include <sys/socket.h>
	77	#include <sys/protosw.h>
	78	#include <sys/syslog.h>
	79
	80	#include <net/if.h>
	81
	82	#include <netinet/in.h>
	83	#include <netinet/in_var.h>
	84	#include <netinet/ip6.h>
	85	#include <netinet6/ip6_var.h>
	86	#include <netinet/icmp6.h>
	87	#include <netinet6/mld6_var.h>
	88
	89	#include <net/net_osdep.h>
	90
	91	/*
	92	* Protocol constants
	93	*/
	94
	95	/* denotes that the MLD max response delay field specifies time in milliseconds */
	96	#define MLD6_TIMER_SCALE 1000
	97	/*
	98	* time between repetitions of a node's initial report of interest in a
	99	* multicast address(in seconds)
	100	*/
	101	#define MLD6_UNSOLICITED_REPORT_INTERVAL 10
	102
91447636	103	extern lck_mtx_t *nd6_mutex;
1c79356b A	104	static struct ip6_pktopts ip6_opts;
1c79356b A	105	static int mld6_timers_are_running;
55e303ae	106	static int mld6_init_done = 0 ;
1c79356b A	107	/* XXX: These are necessary for KAME's link-local hack */
	108	static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
	109	static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
	110
91447636	111	static void mld6_sendpkt(struct in6_multi , int, const struct in6_addr );
1c79356b A	112
	113	void
	114	mld6_init()
	115	{
	116	static u_int8_t hbh_buf[8];
	117	struct ip6_hbh hbh = (struct ip6_hbh )hbh_buf;
	118	u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
	119
55e303ae A	120	if (mld6_init_done)
	121	return;
	122
	123	mld6_init_done = 1;
1c79356b A	124	mld6_timers_are_running = 0;
	125
	126	/* ip6h_nxt will be fill in later */
	127	hbh->ip6h_len = 0; /* (8 >> 3) - 1 */
	128
	129	/* XXX: grotty hard coding... */
	130	hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */
	131	hbh_buf[3] = 0;
	132	hbh_buf[4] = IP6OPT_RTALERT;
	133	hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
	134	bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
	135
9bccf70c	136	init_ip6pktopts(&ip6_opts);
1c79356b	137	ip6_opts.ip6po_hbh = hbh;
1c79356b A	138	}
	139
	140	void
91447636 A	141	mld6_start_listening(
91447636 A	142	struct in6_multi *in6m)
1c79356b	143	{
1c79356b	144	int s = splnet();
1c79356b A	145
	146	/*
	147	* RFC2710 page 10:
	148	* The node never sends a Report or Done for the link-scope all-nodes
	149	* address.
	150	* MLD messages are never sent for multicast addresses whose scope is 0
	151	* (reserved) or 1 (node-local).
	152	*/
	153	mld6_all_nodes_linklocal.s6_addr16[1] =
	154	htons(in6m->in6m_ifp->if_index); /* XXX */
	155	if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) \|\|
	156	IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
	157	in6m->in6m_timer = 0;
	158	in6m->in6m_state = MLD6_OTHERLISTENER;
	159	} else {
	160	mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
	161	in6m->in6m_timer = MLD6_RANDOM_DELAY(
	162	MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
	163	in6m->in6m_state = MLD6_IREPORTEDLAST;
	164	mld6_timers_are_running = 1;
	165	}
	166	splx(s);
	167	}
	168
	169	void
91447636 A	170	mld6_stop_listening(
91447636 A	171	struct in6_multi *in6m)
1c79356b A	172	{
	173	mld6_all_nodes_linklocal.s6_addr16[1] =
	174	htons(in6m->in6m_ifp->if_index); /* XXX */
	175	mld6_all_routers_linklocal.s6_addr16[1] =
	176	htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
	177
	178	if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
	179	(!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
	180	IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
	181	mld6_sendpkt(in6m, MLD6_LISTENER_DONE,
	182	&mld6_all_routers_linklocal);
	183	}
	184
	185	void
91447636 A	186	mld6_input(
	187	struct mbuf *m,
	188	int off)
1c79356b A	189	{
	190	struct ip6_hdr ip6 = mtod(m, struct ip6_hdr );
	191	struct mld6_hdr *mldh;
	192	struct ifnet *ifp = m->m_pkthdr.rcvif;
	193	struct in6_multi *in6m;
	194	struct in6_ifaddr *ia;
1c79356b	195	struct ifmultiaddr *ifma;
1c79356b A	196	int timer; /* timer value in the MLD query header */
1c79356b A	197
9bccf70c	198	#ifndef PULLDOWN_TEST
91447636	199	IP6_EXTHDR_CHECK(m, off, sizeof(*mldh), return);
9bccf70c A	200	mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off);
	201	#else
	202	IP6_EXTHDR_GET(mldh, struct mld6_hdr , m, off, sizeof(mldh));
	203	if (mldh == NULL) {
	204	icmp6stat.icp6s_tooshort++;
	205	return;
	206	}
	207	#endif
	208
1c79356b	209	/* source address validation */
9bccf70c	210	ip6 = mtod(m, struct ip6_hdr );/ in case mpullup */
1c79356b A	211	if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
1c79356b A	212	log(LOG_ERR,
9bccf70c A	213	"mld6_input: src %s is not link-local (grp=%s)\n",
	214	ip6_sprintf(&ip6->ip6_src),
	215	ip6_sprintf(&mldh->mld6_addr));
1c79356b A	216	/*
	217	* spec (RFC2710) does not explicitly
	218	* specify to discard the packet from a non link-local
	219	* source address. But we believe it's expected to do so.
9bccf70c	220	* XXX: do we have to allow :: as source?
1c79356b A	221	*/
	222	m_freem(m);
	223	return;
	224	}
	225
1c79356b A	226	/*
	227	* In the MLD6 specification, there are 3 states and a flag.
	228	*
	229	* In Non-Listener state, we simply don't have a membership record.
	230	* In Delaying Listener state, our timer is running (in6m->in6m_timer)
	231	* In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
	232	*
	233	* The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
	234	* we have heard a report from another member, or MLD6_IREPORTEDLAST
	235	* if we sent the last report.
	236	*/
	237	switch(mldh->mld6_type) {
	238	case MLD6_LISTENER_QUERY:
	239	if (ifp->if_flags & IFF_LOOPBACK)
	240	break;
	241
	242	if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) &&
9bccf70c	243	!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
1c79356b A	244	break; /* print error or log stat? */
	245	if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
	246	mldh->mld6_addr.s6_addr16[1] =
	247	htons(ifp->if_index); /* XXX */
	248
	249	/*
	250	* - Start the timers in all of our membership records
	251	* that the query applies to for the interface on
	252	* which the query arrived excl. those that belong
	253	* to the "all-nodes" group (ff02::1).
	254	* - Restart any timer that is already running but has
	255	* A value longer than the requested timeout.
	256	* - Use the value specified in the query message as
	257	* the maximum timeout.
	258	*/
91447636	259	ifnet_lock_exclusive(ifp);
1c79356b A	260	IFP_TO_IA6(ifp, ia);
	261	if (ia == NULL)
	262	break;
	263
	264	/*
	265	* XXX: System timer resolution is too low to handle Max
	266	* Response Delay, so set 1 to the internal timer even if
	267	* the calculated value equals to zero when Max Response
	268	* Delay is positive.
	269	*/
	270	timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
	271	if (timer == 0 && mldh->mld6_maxdelay)
	272	timer = 1;
	273	mld6_all_nodes_linklocal.s6_addr16[1] =
	274	htons(ifp->if_index); /* XXX */
	275
1c79356b	276	LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
1c79356b	277	{
1c79356b A	278	if (ifma->ifma_addr->sa_family != AF_INET6)
	279	continue;
	280	in6m = (struct in6_multi *)ifma->ifma_protospec;
	281	if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
	282	&mld6_all_nodes_linklocal) \|\|
	283	IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
	284	IPV6_ADDR_SCOPE_LINKLOCAL)
	285	continue;
1c79356b A	286
	287	if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) \|\|
	288	IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr,
	289	&in6m->in6m_addr))
	290	{
	291	if (timer == 0) {
	292	/* send a report immediately */
	293	mld6_sendpkt(in6m, MLD6_LISTENER_REPORT,
	294	NULL);
	295	in6m->in6m_timer = 0; /* reset timer */
	296	in6m->in6m_state = MLD6_IREPORTEDLAST;
	297	}
	298	else if (in6m->in6m_timer == 0 \|\| /idle state/
	299	in6m->in6m_timer > timer) {
	300	in6m->in6m_timer =
	301	MLD6_RANDOM_DELAY(timer);
	302	mld6_timers_are_running = 1;
	303	}
	304	}
	305	}
91447636	306	ifnet_lock_done(ifp);
1c79356b A	307
	308	if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
	309	mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
	310	break;
	311	case MLD6_LISTENER_REPORT:
	312	/*
	313	* For fast leave to work, we have to know that we are the
	314	* last person to send a report for this group. Reports
	315	* can potentially get looped back if we are a multicast
	316	* router, so discard reports sourced by me.
	317	* Note that it is impossible to check IFF_LOOPBACK flag of
	318	* ifp for this purpose, since ip6_mloopback pass the physical
	319	* interface to looutput.
	320	*/
	321	if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
	322	break;
	323
	324	if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
	325	break;
	326
	327	if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
	328	mldh->mld6_addr.s6_addr16[1] =
	329	htons(ifp->if_index); /* XXX */
	330	/*
	331	* If we belong to the group being reported, stop
	332	* our timer for that group.
	333	*/
91447636	334	ifnet_lock_shared(ifp);
1c79356b A	335	IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m);
	336	if (in6m) {
	337	in6m->in6m_timer = 0; /* transit to idle state */
	338	in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
	339	}
91447636	340	ifnet_lock_done(ifp);
1c79356b A	341
	342	if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
	343	mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
	344	break;
	345	default: /* this is impossible */
	346	log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type);
	347	break;
	348	}
	349
	350	m_freem(m);
	351	}
	352
	353	void
	354	mld6_fasttimeo()
	355	{
9bccf70c	356	struct in6_multi *in6m;
1c79356b	357	struct in6_multistep step;
1c79356b A	358
	359	/*
	360	* Quick check to see if any work needs to be done, in order
	361	* to minimize the overhead of fasttimo processing.
	362	*/
	363	if (!mld6_timers_are_running)
	364	return;
	365
91447636	366	lck_mtx_lock(nd6_mutex);
1c79356b A	367	mld6_timers_are_running = 0;
	368	IN6_FIRST_MULTI(step, in6m);
	369	while (in6m != NULL) {
	370	if (in6m->in6m_timer == 0) {
	371	/* do nothing */
	372	} else if (--in6m->in6m_timer == 0) {
	373	mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
	374	in6m->in6m_state = MLD6_IREPORTEDLAST;
	375	} else {
	376	mld6_timers_are_running = 1;
	377	}
	378	IN6_NEXT_MULTI(step, in6m);
	379	}
91447636	380	lck_mtx_unlock(nd6_mutex);
1c79356b A	381	}
	382
	383	static void
91447636 A	384	mld6_sendpkt(
	385	struct in6_multi *in6m,
	386	int type,
	387	const struct in6_addr *dst)
1c79356b A	388	{
	389	struct mbuf mh, md;
	390	struct mld6_hdr *mldh;
	391	struct ip6_hdr *ip6;
	392	struct ip6_moptions im6o;
	393	struct in6_ifaddr *ia;
	394	struct ifnet *ifp = in6m->in6m_ifp;
	395	struct ifnet *outif = NULL;
	396
	397	/*
	398	* At first, find a link local address on the outgoing interface
	399	* to use as the source address of the MLD packet.
	400	*/
	401	if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY\|IN6_IFF_ANYCAST))
	402	== NULL)
	403	return;
	404
	405	/*
	406	* Allocate mbufs to store ip6 header and MLD header.
	407	* We allocate 2 mbufs and make chain in advance because
	408	* it is more convenient when inserting the hop-by-hop option later.
	409	*/
	410	MGETHDR(mh, M_DONTWAIT, MT_HEADER);
	411	if (mh == NULL)
	412	return;
	413	MGET(md, M_DONTWAIT, MT_DATA);
	414	if (md == NULL) {
	415	m_free(mh);
	416	return;
	417	}
	418	mh->m_next = md;
	419
9bccf70c	420	mh->m_pkthdr.rcvif = NULL;
1c79356b A	421	mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr);
	422	mh->m_len = sizeof(struct ip6_hdr);
	423	MH_ALIGN(mh, sizeof(struct ip6_hdr));
	424
	425	/* fill in the ip6 header */
	426	ip6 = mtod(mh, struct ip6_hdr *);
	427	ip6->ip6_flow = 0;
	428	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
	429	ip6->ip6_vfc \|= IPV6_VERSION;
	430	/* ip6_plen will be set later */
	431	ip6->ip6_nxt = IPPROTO_ICMPV6;
	432	/* ip6_hlim will be set by im6o.im6o_multicast_hlim */
	433	ip6->ip6_src = ia->ia_addr.sin6_addr;
	434	ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
	435
	436	/* fill in the MLD header */
	437	md->m_len = sizeof(struct mld6_hdr);
	438	mldh = mtod(md, struct mld6_hdr *);
	439	mldh->mld6_type = type;
	440	mldh->mld6_code = 0;
	441	mldh->mld6_cksum = 0;
	442	/* XXX: we assume the function will not be called for query messages */
	443	mldh->mld6_maxdelay = 0;
	444	mldh->mld6_reserved = 0;
	445	mldh->mld6_addr = in6m->in6m_addr;
	446	if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
	447	mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
	448	mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
	449	sizeof(struct mld6_hdr));
	450
	451	/* construct multicast option */
	452	bzero(&im6o, sizeof(im6o));
	453	im6o.im6o_multicast_ifp = ifp;
	454	im6o.im6o_multicast_hlim = 1;
	455
	456	/*
	457	* Request loopback of the report if we are acting as a multicast
	458	* router, so that the process-level routing daemon can hear it.
	459	*/
	460	im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
	461
	462	/* increment output statictics */
	463	icmp6stat.icp6s_outhist[type]++;
	464
91447636	465	ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, 0);
1c79356b A	466	if (outif) {
1c79356b A	467	icmp6_ifstat_inc(outif, ifs6_out_msg);
9bccf70c A	468	switch (type) {
	469	case MLD6_LISTENER_QUERY:
	470	icmp6_ifstat_inc(outif, ifs6_out_mldquery);
	471	break;
	472	case MLD6_LISTENER_REPORT:
	473	icmp6_ifstat_inc(outif, ifs6_out_mldreport);
	474	break;
	475	case MLD6_LISTENER_DONE:
	476	icmp6_ifstat_inc(outif, ifs6_out_mlddone);
	477	break;
1c79356b A	478	}
	479	}
	480	}