[BACK]Return to mld6.c CVS log [TXT][DIR] Up to [cvs.NetBSD.org] / src / sys / netinet6

File: [cvs.NetBSD.org] / src / sys / netinet6 / mld6.c (download)

Revision 1.12, Wed Mar 1 12:49:48 2000 UTC (20 years, 8 months ago) by itojun
Branch: MAIN
CVS Tags: netbsd-1-5-base, netbsd-1-5-RELEASE, netbsd-1-5-PATCH003, netbsd-1-5-PATCH002, netbsd-1-5-PATCH001, netbsd-1-5-BETA2, netbsd-1-5-BETA, netbsd-1-5-ALPHA2, netbsd-1-5, minoura-xpg4dl-base, minoura-xpg4dl
Changes since 1.11: +1 -5 lines

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)

/*	$NetBSD: mld6.c,v 1.12 2000/03/01 12:49:48 itojun Exp $	*/
/*	$KAME: mld6.c,v 1.16 2000/02/22 14:04:27 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 "opt_inet.h"

#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

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));

	ip6_opts.ip6po_hbh = hbh;
	/* We will specify the hoplimit by a multicast option. */
	ip6_opts.ip6po_hlim = -1;
}

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

	/*
	 * 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(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_NODELOCAL)
		mld6_sendpkt(in6m, MLD6_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 mld6_hdr *mldh;
	struct ifnet *ifp = m->m_pkthdr.rcvif;
	struct in6_multi *in6m;
	struct in6_ifaddr *ia;
	int timer;		/* timer value in the MLD query header */

	/* source address validation */
	if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
		log(LOG_ERR,
		    "mld6_input: src %s is not link-local\n",
		    ip6_sprintf(&ip6->ip6_src));
		/*
		 * 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;
	}

#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
	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

	/*
	 * 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.
		 */
		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 */
		
		for (in6m = ia->ia6_multiaddrs.lh_first;
		     in6m;
		     in6m = in6m->in6m_entry.le_next)
		{
			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;
				}
			}
		}

		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.
		 */
		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 */
		}

		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()
{
	register struct in6_multi *in6m;
	struct in6_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 (!mld6_timers_are_running)
		return;

	s = splsoftnet();
	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);
	}
	splx(s);
}

static void
mld6_sendpkt(in6m, type, dst)
	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.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);
	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;
		}
	}
}