mld6.c

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//==========================================================================
//
//      src/sys/netinet6/mld6.c
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD, 
// FreeBSD or other sources, and are covered by the appropriate
// copyright disclaimers included herein.
//
// Portions created by Red Hat are
// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================

/*	$KAME: mld6.c,v 1.35 2001/12/18 02:23:44 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/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#ifdef __OpenBSD__
#include <dev/rndvar.h>
#endif

#include <net/if.h>
#ifdef NEW_STRUCT_ROUTE
#include <net/route.h>
#endif

#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>

/*
 * 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

static struct ip6_pktopts ip6_opts;
static int mld6_timers_are_running;
/* 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 __P((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);

	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(in6m)
	struct in6_multi *in6m;
{
#ifdef __NetBSD__
	int s = splsoftnet();
#else
	int s = splnet();
#endif

	/*
	 * 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, MLD_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(in6m)
	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_INTFACELOCAL)
		mld6_sendpkt(in6m, MLD_LISTENER_DONE,
			     &mld6_all_routers_linklocal);
}

void
mld6_input(m, off)
	struct mbuf *m;
	int off;
{
	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
	struct mld_hdr *mldh;
	struct ifnet *ifp = m->m_pkthdr.rcvif;
	struct in6_multi *in6m;
	struct in6_ifaddr *ia;
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
	struct ifmultiaddr *ifma;
#endif
	int timer;		/* timer value in the MLD query header */

#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
	mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
#else
	IP6_EXTHDR_GET(mldh, struct mld_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) ||
	      IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src))) {
#if 0 /* do not log in an input path */
		log(LOG_INFO,
		    "mld6_input: src %s is not link-local (grp=%s)\n",
		    ip6_sprintf(&ip6->ip6_src),
		    ip6_sprintf(&mldh->mld_addr));
#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;
	}

	/*
	 * 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->mld_type) {
	case MLD_LISTENER_QUERY: