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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:

                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.

                 */

                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->mld_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;

                if (timer == 0 && mldh->mld_maxdelay)

                        timer = 1;

                mld6_all_nodes_linklocal.s6_addr16[1] =

                        htons(ifp->if_index); /* XXX */

#if defined(__FreeBSD__) && __FreeBSD__ >= 3

                LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)

#else

                for (in6m = ia->ia6_multiaddrs.lh_first;

                     in6m;

                     in6m = in6m->in6m_entry.le_next)

#endif

                {

#if defined(__FreeBSD__) && __FreeBSD__ >= 3

                        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;

#else

                        if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,

                                                &mld6_all_nodes_linklocal) ||

                            IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <

                            IPV6_ADDR_SCOPE_LINKLOCAL)

                                continue;

#endif

                        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 = MLD6_IREPORTEDLAST;

                                }

                                else if (in6m->in6m_timer == 0 || /* idle */

                                        in6m->in6m_timer > timer) {

                                        in6m->in6m_timer =

                                                MLD6_RANDOM_DELAY(timer);

                                        mld6_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 looutput.

                 */

                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 = MLD6_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 */

                log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);

                break;

        }

        m_freem(m);

}

void

mld6_fasttimeo()

{

        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;

#ifdef __NetBSD__

        s = splsoftnet();

#else

        s = splnet();

#endif

        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, MLD_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 mld_hdr *mldh;

        struct ip6_hdr *ip6;

        struct ip6_moptions im6o;

        struct in6_ifaddr *ia;

        struct ifnet *ifp = in6m->in6m_ifp;

        int ignflags;

        /*

         * 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_NOTREADY|IN6_IFF_ANYCAST) & ~IN6_IFF_TENTATIVE;

        if ((ia = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL)

                return;

        if ((ia->ia6_flags & IN6_IFF_TENTATIVE))

                ia = 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)

                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 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_multicast_hlim */

        ip6->ip6_src = ia ? ia->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 */

        mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,

                                     sizeof(struct ip6_hdr),

                                     sizeof(struct mld_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]++;

        icmp6_ifstat_inc(ifp, ifs6_out_msg);

        switch (type) {

        case MLD_LISTENER_QUERY:

                icmp6_ifstat_inc(ifp, ifs6_out_mldquery);

                break;

        case MLD_LISTENER_REPORT:

                icmp6_ifstat_inc(ifp, ifs6_out_mldreport);

                break;

        case MLD_LISTENER_DONE:

                icmp6_ifstat_inc(ifp, ifs6_out_mlddone);

                break;

        }

        ip6_output(mh, &ip6_opts, NULL, ia ? 0 : IPV6_UNSPECSRC, &im6o, NULL);

}