/*      $OpenBSD: ip6_mroute.c,v 1.156 2025/11/13 23:30:01 bluhm Exp $  */
/*      $NetBSD: ip6_mroute.c,v 1.59 2003/12/10 09:28:38 itojun Exp $   */
/*      $KAME: ip6_mroute.c,v 1.45 2001/03/25 08:38:51 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.
 */

/*      BSDI ip_mroute.c,v 2.10 1996/11/14 00:29:52 jch Exp     */

/*
 * Copyright (c) 1989 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.
 *
 *      @(#)ip_mroute.c 8.2 (Berkeley) 11/15/93
 */

/*
 * IP multicast forwarding procedures
 *
 * Written by David Waitzman, BBN Labs, August 1988.
 * Modified by Steve Deering, Stanford, February 1989.
 * Modified by Mark J. Steiglitz, Stanford, May, 1991
 * Modified by Van Jacobson, LBL, January 1993
 * Modified by Ajit Thyagarajan, PARC, August 1993
 * Modified by Bill Fenner, PARC, April 1994
 *
 * MROUTING Revision: 3.5.1.2
 */

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/ip6_mroute.h>
#include <netinet/in_pcb.h>

/*
 * Locks used to protect data:
 *      I       immutable after creation
 */

/* #define MCAST_DEBUG */

#ifdef MCAST_DEBUG
int mcast6_debug = 1;
#define DPRINTF(fmt, args...)                                           \
        do {                                                            \
                if (mcast6_debug)                                       \
                        printf("%s:%d " fmt "\n",                       \
                            __func__, __LINE__, ## args);               \
        } while (0)
#else
#define DPRINTF(fmt, args...)                   \
        do { } while (0)
#endif

int ip6_mdq(struct mbuf *, struct ifnet *, struct rtentry *, int);
void phyint_send6(struct ifnet *, struct ip6_hdr *, struct mbuf *, int, int);

/*
 * Globals.  All but ip6_mrouter, ip6_mrtproto and mrt6stat could be static,
 * except for netstat or debugging purposes.
 */
struct socket  *ip6_mrouter[RT_TABLEID_MAX + 1];
struct rttimer_queue ip6_mrouterq;
int             ip6_mrouter_ver = 0;
int             ip6_mrtproto;    /* [I] for netstat only */
struct cpumem *mrt6counters;

int get_sg6_cnt(struct sioc_sg_req6 *, unsigned int);
int get_mif6_cnt(struct sioc_mif_req6 *, unsigned int);
int ip6_mrouter_init(struct socket *, int, int);
int add_m6if(struct socket *, struct mif6ctl *);
int del_m6if(struct socket *, mifi_t *);
int add_m6fc(struct socket *, struct mf6cctl *);
int del_m6fc(struct socket *, struct mf6cctl *);
void mf6c_expire_route(struct rtentry *, u_int);
struct ifnet *mrt6_iflookupbymif(mifi_t, unsigned int);
struct rtentry *mf6c_find(struct ifnet *, struct in6_addr *, unsigned int);
struct rtentry *mrt6_mcast_add(struct ifnet *, struct sockaddr *);
void mrt6_mcast_del(struct rtentry *, unsigned int);

/*
 * Handle MRT setsockopt commands to modify the multicast routing tables.
 */
int
ip6_mrouter_set(int cmd, struct socket *so, struct mbuf *m)
{
        struct inpcb    *inp = sotoinpcb(so);

        if (cmd != MRT6_INIT && so != ip6_mrouter[inp->inp_rtableid])
                return (EPERM);

        switch (cmd) {
        case MRT6_INIT:
                if (m == NULL || m->m_len < sizeof(int))
                        return (EINVAL);
                return (ip6_mrouter_init(so, *mtod(m, int *), cmd));
        case MRT6_DONE:
                return (ip6_mrouter_done(so));
        case MRT6_ADD_MIF:
                if (m == NULL || m->m_len < sizeof(struct mif6ctl))
                        return (EINVAL);
                return (add_m6if(so, mtod(m, struct mif6ctl *)));
        case MRT6_DEL_MIF:
                if (m == NULL || m->m_len < sizeof(mifi_t))
                        return (EINVAL);
                return (del_m6if(so, mtod(m, mifi_t *)));
        case MRT6_ADD_MFC:
                if (m == NULL || m->m_len < sizeof(struct mf6cctl))
                        return (EINVAL);
                return (add_m6fc(so, mtod(m, struct mf6cctl *)));
        case MRT6_DEL_MFC:
                if (m == NULL || m->m_len < sizeof(struct mf6cctl))
                        return (EINVAL);
                return (del_m6fc(so, mtod(m,  struct mf6cctl *)));
        default:
                return (EOPNOTSUPP);
        }
}

/*
 * Handle MRT getsockopt commands
 */
int
ip6_mrouter_get(int cmd, struct socket *so, struct mbuf *m)
{
        struct inpcb    *inp = sotoinpcb(so);

        if (so != ip6_mrouter[inp->inp_rtableid])
                return (EPERM);

        switch (cmd) {
        default:
                return EOPNOTSUPP;
        }
}

void
mrt6_init(void)
{
        mrt6counters = counters_alloc(mrt6s_ncounters);

        rt_timer_queue_init(&ip6_mrouterq, MCAST_EXPIRE_TIMEOUT,
            &mf6c_expire_route);
}

/*
 * Handle ioctl commands to obtain information from the cache
 */
int
mrt6_ioctl(struct socket *so, u_long cmd, caddr_t data)
{
        struct inpcb *inp = sotoinpcb(so);
        int error;

        if (inp == NULL)
                return (ENOTCONN);

        KERNEL_LOCK();

        switch (cmd) {
        case SIOCGETSGCNT_IN6:
                NET_LOCK_SHARED();
                error = get_sg6_cnt((struct sioc_sg_req6 *)data,
                    inp->inp_rtableid);
                NET_UNLOCK_SHARED();
                break;
        case SIOCGETMIFCNT_IN6:
                NET_LOCK_SHARED();
                error = get_mif6_cnt((struct sioc_mif_req6 *)data,
                    inp->inp_rtableid);
                NET_UNLOCK_SHARED();
                break;
        default:
                error = ENOTTY;
                break;
        }

        KERNEL_UNLOCK();
        return error;
}

/*
 * returns the packet, byte, rpf-failure count for the source group provided
 */
int
get_sg6_cnt(struct sioc_sg_req6 *req, unsigned int rtableid)
{
        struct rtentry *rt;
        struct mf6c *mf6c;

        rt = mf6c_find(NULL, &req->grp.sin6_addr, rtableid);
        if (rt == NULL) {
                req->pktcnt = req->bytecnt = req->wrong_if = 0xffffffff;
                return EADDRNOTAVAIL;
        }

        req->pktcnt = req->bytecnt = req->wrong_if = 0;
        do {
                mf6c = (struct mf6c *)rt->rt_llinfo;
                if (mf6c == NULL)
                        continue;

                req->pktcnt += mf6c->mf6c_pkt_cnt;
                req->bytecnt += mf6c->mf6c_byte_cnt;
                req->wrong_if += mf6c->mf6c_wrong_if;
        } while ((rt = rtable_iterate(rt)) != NULL);

        return 0;
}

/*
 * returns the input and output packet and byte counts on the mif provided
 */
int
get_mif6_cnt(struct sioc_mif_req6 *req, unsigned int rtableid)
{
        struct ifnet *ifp;
        struct mif6 *m6;

        if ((ifp = mrt6_iflookupbymif(req->mifi, rtableid)) == NULL)
                return EINVAL;

        m6 = (struct mif6 *)ifp->if_mcast6;
        req->icount = m6->m6_pkt_in;
        req->ocount = m6->m6_pkt_out;
        req->ibytes = m6->m6_bytes_in;
        req->obytes = m6->m6_bytes_out;

        return 0;
}

int
mrt6_sysctl_mif(void *oldp, size_t *oldlenp)
{
        TAILQ_HEAD(, ifnet) if_tmplist =
            TAILQ_HEAD_INITIALIZER(if_tmplist);
        struct ifnet *ifp;
        caddr_t where = oldp;
        size_t needed, given;
        struct mif6 *mifp;
        struct mif6info minfo;
        int error = 0;

        given = *oldlenp;
        needed = 0;
        memset(&minfo, 0, sizeof minfo);

        rw_enter_write(&if_tmplist_lock);
        NET_LOCK_SHARED();

        TAILQ_FOREACH(ifp, &ifnetlist, if_list) {
                if (ifp->if_mcast6 != NULL) {
                        if_ref(ifp);
                        TAILQ_INSERT_TAIL(&if_tmplist, ifp, if_tmplist);
                }
        }
        NET_UNLOCK_SHARED();

        TAILQ_FOREACH (ifp, &if_tmplist, if_tmplist) {
                NET_LOCK_SHARED();
                if ((mifp = (struct mif6 *)ifp->if_mcast6) == NULL) {
                        NET_UNLOCK_SHARED();
                        continue;
                }

                minfo.m6_mifi = mifp->m6_mifi;
                minfo.m6_flags = mifp->m6_flags;
                minfo.m6_lcl_addr = mifp->m6_lcl_addr;
                minfo.m6_ifindex = ifp->if_index;
                minfo.m6_pkt_in = mifp->m6_pkt_in;
                minfo.m6_pkt_out = mifp->m6_pkt_out;
                minfo.m6_bytes_in = mifp->m6_bytes_in;
                minfo.m6_bytes_out = mifp->m6_bytes_out;
                minfo.m6_rate_limit = mifp->m6_rate_limit;
                NET_UNLOCK_SHARED();

                needed += sizeof(minfo);
                if (where && needed <= given) {
                        error = copyout(&minfo, where, sizeof(minfo));
                        if (error)
                                break;
                        where += sizeof(minfo);
                }
        }

        while ((ifp = TAILQ_FIRST(&if_tmplist))) {
                TAILQ_REMOVE(&if_tmplist, ifp, if_tmplist);
                if_put(ifp);
        }

        rw_exit_write(&if_tmplist_lock);

        if (error)
                return (error);

        if (where) {
                *oldlenp = needed;
                if (given < needed)
                        return (ENOMEM);
        } else
                *oldlenp = (11 * needed) / 10;

        return (0);
}

struct mf6csysctlarg {
        struct mf6cinfo *ms6a_minfos;
        size_t           ms6a_len;
        size_t           ms6a_needed;
};

int
mrt6_rtwalk_mf6csysctl(struct rtentry *rt, void *arg, unsigned int rtableid)
{
        struct mf6c             *mf6c = (struct mf6c *)rt->rt_llinfo;
        struct mf6csysctlarg    *msa = arg;
        struct ifnet            *ifp;
        struct mif6             *m6;
        struct mf6cinfo         *minfo;
        int                      new = 0;

        /* Skip entries being removed. */
        if (mf6c == NULL)
                return 0;

        /* Skip non-multicast routes. */
        if (ISSET(rt->rt_flags, RTF_HOST | RTF_MULTICAST) !=
            (RTF_HOST | RTF_MULTICAST))
                return 0;

        /* User just asked for the output size. */
        if (msa->ms6a_minfos == NULL) {
                msa->ms6a_needed += sizeof(*minfo);
                return 0;
        }

        /* Skip route with invalid interfaces. */
        if ((ifp = if_get(rt->rt_ifidx)) == NULL)
                return 0;
        if ((m6 = (struct mif6 *)ifp->if_mcast6) == NULL) {
                if_put(ifp);
                return 0;
        }

        for (minfo = msa->ms6a_minfos;
            (uint8_t *)(minfo + 1) <=
            (uint8_t *)msa->ms6a_minfos + msa->ms6a_len;
            minfo++) {
                /* Find a new entry or update old entry. */
                if (!IN6_ARE_ADDR_EQUAL(&minfo->mf6c_origin.sin6_addr,
                    &satosin6(rt->rt_gateway)->sin6_addr) ||
                    !IN6_ARE_ADDR_EQUAL(&minfo->mf6c_mcastgrp.sin6_addr,
                    &satosin6(rt_key(rt))->sin6_addr)) {
                        if (!IN6_IS_ADDR_UNSPECIFIED(
                            &minfo->mf6c_origin.sin6_addr) ||
                            !IN6_IS_ADDR_UNSPECIFIED(
                            &minfo->mf6c_mcastgrp.sin6_addr))
                                continue;

                        new = 1;
                }

                minfo->mf6c_origin = *satosin6(rt->rt_gateway);
                minfo->mf6c_mcastgrp = *satosin6(rt_key(rt));
                minfo->mf6c_parent = mf6c->mf6c_parent;
                minfo->mf6c_pkt_cnt += mf6c->mf6c_pkt_cnt;
                minfo->mf6c_byte_cnt += mf6c->mf6c_byte_cnt;
                IF_SET(m6->m6_mifi, &minfo->mf6c_ifset);
                break;
        }

        if (new != 0)
                msa->ms6a_needed += sizeof(*minfo);

        if_put(ifp);

        return 0;
}

int
mrt6_sysctl_mrt6stat(void *oldp, size_t *oldlenp, void *newp)
{
        uint64_t counters[mrt6s_ncounters];
        struct mrt6stat mrt6stat;
        int i = 0;

#define ASSIGN(field)  do { mrt6stat.field = counters[i++]; } while (0)

        memset(&mrt6stat, 0, sizeof mrt6stat);
        counters_read(mrt6counters, counters, nitems(counters), NULL);

        ASSIGN(mrt6s_mfc_lookups);
        ASSIGN(mrt6s_mfc_misses);
        ASSIGN(mrt6s_upcalls);
        ASSIGN(mrt6s_no_route);
        ASSIGN(mrt6s_bad_tunnel);
        ASSIGN(mrt6s_cant_tunnel);
        ASSIGN(mrt6s_wrong_if);
        ASSIGN(mrt6s_upq_ovflw);
        ASSIGN(mrt6s_cache_cleanups);
        ASSIGN(mrt6s_drop_sel);
        ASSIGN(mrt6s_q_overflow);
        ASSIGN(mrt6s_pkt2large);
        ASSIGN(mrt6s_upq_sockfull);

#undef ASSIGN

        return (sysctl_rdstruct(oldp, oldlenp, newp,
            &mrt6stat, sizeof(mrt6stat)));
}

int
mrt6_sysctl_mfc(void *oldp, size_t *oldlenp)
{
        unsigned int             rtableid;
        int                      error;
        struct mf6csysctlarg     msa;

        if (oldp != NULL && *oldlenp > MAXPHYS)
                return EINVAL;

        memset(&msa, 0, sizeof(msa));
        if (oldp != NULL && *oldlenp > 0) {
                msa.ms6a_minfos = malloc(*oldlenp, M_TEMP, M_WAITOK | M_ZERO);
                msa.ms6a_len = *oldlenp;
        }

        NET_LOCK();
        for (rtableid = 0; rtableid <= RT_TABLEID_MAX; rtableid++) {
                rtable_walk(rtableid, AF_INET6, NULL, mrt6_rtwalk_mf6csysctl,
                    &msa);
        }
        NET_UNLOCK();

        if (msa.ms6a_minfos != NULL && msa.ms6a_needed > 0 &&
            (error = copyout(msa.ms6a_minfos, oldp, msa.ms6a_needed)) != 0) {
                free(msa.ms6a_minfos, M_TEMP, msa.ms6a_len);
                return error;
        }

        free(msa.ms6a_minfos, M_TEMP, msa.ms6a_len);
        *oldlenp = msa.ms6a_needed;

        return 0;
}

/*
 * Enable multicast routing
 */
int
ip6_mrouter_init(struct socket *so, int v, int cmd)
{
        struct inpcb *inp = sotoinpcb(so);
        unsigned int rtableid = inp->inp_rtableid;

        if (so->so_type != SOCK_RAW ||
            so->so_proto->pr_protocol != IPPROTO_ICMPV6)
                return (EOPNOTSUPP);

        if (v != 1)
                return (ENOPROTOOPT);

        if (ip6_mrouter[rtableid] != NULL)
                return (EADDRINUSE);

        ip6_mrouter[rtableid] = so;
        ip6_mrouter_ver = cmd;

        return (0);
}

int
mrouter6_rtwalk_delete(struct rtentry *rt, void *arg, unsigned int rtableid)
{
        /* Skip non-multicast routes. */
        if (ISSET(rt->rt_flags, RTF_HOST | RTF_MULTICAST) !=
            (RTF_HOST | RTF_MULTICAST))
                return 0;

        return EEXIST;
}

/*
 * Disable multicast routing
 */
int
ip6_mrouter_done(struct socket *so)
{
        struct inpcb *inp = sotoinpcb(so);
        struct ifnet *ifp;
        unsigned int rtableid = inp->inp_rtableid;
        int error;

        NET_ASSERT_LOCKED();

        /* Delete all remaining installed multicast routes. */
        do {
                struct rtentry *rt = NULL;

                error = rtable_walk(rtableid, AF_INET6, &rt,
                    mrouter6_rtwalk_delete, NULL);
                if (rt != NULL && error == EEXIST) {
                        mrt6_mcast_del(rt, rtableid);
                        error = EAGAIN;
                }
                rtfree(rt);
        } while (error == EAGAIN);

        /* Unregister all interfaces in the domain. */
        TAILQ_FOREACH(ifp, &ifnetlist, if_list) {
                if (ifp->if_rdomain != rtableid)
                        continue;

                ip6_mrouter_detach(ifp);
        }

        ip6_mrouter[inp->inp_rtableid] = NULL;
        ip6_mrouter_ver = 0;

        return 0;
}

void
ip6_mrouter_detach(struct ifnet *ifp)
{
        struct mif6 *m6 = (struct mif6 *)ifp->if_mcast6;
        struct in6_ifreq ifr;

        if (m6 == NULL)
                return;

        ifp->if_mcast6 = NULL;

        memset(&ifr, 0, sizeof(ifr));
        ifr.ifr_addr.sin6_family = AF_INET6;
        ifr.ifr_addr.sin6_addr = in6addr_any;
        KERNEL_LOCK();
        (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)&ifr);
        KERNEL_UNLOCK();

        free(m6, M_MRTABLE, sizeof(*m6));
}

/*
 * Add a mif to the mif table
 */
int
add_m6if(struct socket *so, struct mif6ctl *mifcp)
{
        struct inpcb *inp = sotoinpcb(so);
        struct mif6 *mifp;
        struct ifnet *ifp;
        struct in6_ifreq ifr;
        int error;
        unsigned int rtableid = inp->inp_rtableid;

        NET_ASSERT_LOCKED();

        if (mifcp->mif6c_mifi >= MAXMIFS)
                return EINVAL;

        if (mrt6_iflookupbymif(mifcp->mif6c_mifi, rtableid) != NULL)
                return EADDRINUSE; /* XXX: is it appropriate? */

        {
                ifp = if_get(mifcp->mif6c_pifi);
                if (ifp == NULL)
                        return ENXIO;

                /* Make sure the interface supports multicast */
                if ((ifp->if_flags & IFF_MULTICAST) == 0) {
                        if_put(ifp);
                        return EOPNOTSUPP;
                }

                /*
                 * Enable promiscuous reception of all IPv6 multicasts
                 * from the interface.
                 */
                memset(&ifr, 0, sizeof(ifr));
                ifr.ifr_addr.sin6_family = AF_INET6;
                ifr.ifr_addr.sin6_addr = in6addr_any;
                KERNEL_LOCK();
                error = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, (caddr_t)&ifr);
                KERNEL_UNLOCK();

                if (error) {
                        if_put(ifp);
                        return error;
                }
        }

        mifp = malloc(sizeof(*mifp), M_MRTABLE, M_WAITOK | M_ZERO);
        ifp->if_mcast6     = (caddr_t)mifp;
        mifp->m6_mifi      = mifcp->mif6c_mifi;
        mifp->m6_flags     = mifcp->mif6c_flags;
#ifdef notyet
        /* scaling up here allows division by 1024 in critical code */
        mifp->m6_rate_limit = mifcp->mif6c_rate_limit * 1024 / 1000;
#endif

        if_put(ifp);

        return 0;
}

/*
 * Delete a mif from the mif table
 */
int
del_m6if(struct socket *so, mifi_t *mifip)
{
        struct inpcb *inp = sotoinpcb(so);
        struct ifnet *ifp;

        NET_ASSERT_LOCKED();

        if (*mifip >= MAXMIFS)
                return EINVAL;
        if ((ifp = mrt6_iflookupbymif(*mifip, inp->inp_rtableid)) == NULL)
                return EINVAL;

        ip6_mrouter_detach(ifp);

        return 0;
}

int
mf6c_add_route(struct ifnet *ifp, struct sockaddr *origin,
    struct sockaddr *group, struct mf6cctl *mf6cc, int wait)
{
        struct rtentry *rt;
        struct mf6c *mf6c;
        unsigned int rtableid = ifp->if_rdomain;
#ifdef MCAST_DEBUG
        char bsrc[INET6_ADDRSTRLEN], bdst[INET6_ADDRSTRLEN];
#endif /* MCAST_DEBUG */

        rt = mrt6_mcast_add(ifp, group);
        if (rt == NULL)
                return ENOENT;

        mf6c = malloc(sizeof(*mf6c), M_MRTABLE, wait | M_ZERO);
        if (mf6c == NULL) {
                DPRINTF("origin %s group %s parent %d (%s) malloc failed",
                    inet_ntop(AF_INET6, origin, bsrc, sizeof(bsrc)),
                    inet_ntop(AF_INET6, group, bdst, sizeof(bdst)),
                    mf6cc->mf6cc_parent, ifp->if_xname);
                mrt6_mcast_del(rt, rtableid);
                rtfree(rt);
                return ENOMEM;
        }

        rt->rt_llinfo = (caddr_t)mf6c;
        rt_timer_add(rt, &ip6_mrouterq, rtableid);
        mf6c->mf6c_parent = mf6cc->mf6cc_parent;
        rtfree(rt);

        return 0;
}

void
mf6c_update(struct mf6cctl *mf6cc, int wait, unsigned int rtableid)
{
        struct rtentry *rt;
        struct mf6c *mf6c;
        struct ifnet *ifp;
        struct sockaddr_in6 osin6, gsin6;
        mifi_t mifi;
#ifdef MCAST_DEBUG
        char bdst[INET6_ADDRSTRLEN];
#endif /* MCAST_DEBUG */

        memset(&osin6, 0, sizeof(osin6));
        osin6.sin6_family = AF_INET6;
        osin6.sin6_len = sizeof(osin6);
        osin6.sin6_addr = mf6cc->mf6cc_origin.sin6_addr;

        memset(&gsin6, 0, sizeof(gsin6));
        gsin6.sin6_family = AF_INET6;
        gsin6.sin6_len = sizeof(gsin6);
        gsin6.sin6_addr = mf6cc->mf6cc_mcastgrp.sin6_addr;

        for (mifi = 0; mifi < MAXMIFS; mifi++) {
                if (mifi == mf6cc->mf6cc_parent)
                        continue;

                /* Test for mif existence and then update the entry. */
                if ((ifp = mrt6_iflookupbymif(mifi, rtableid)) == NULL)
                        continue;

                rt = mf6c_find(ifp, &mf6cc->mf6cc_mcastgrp.sin6_addr, rtableid);

                /* mif not configured or removed. */
                if (!IF_ISSET(mifi, &mf6cc->mf6cc_ifset)) {
                        /* Route doesn't exist, nothing to do. */
                        if (rt == NULL)
                                continue;

                        DPRINTF("del route (group %s) for mif %d (%s)",
                            inet_ntop(AF_INET6,
                            &mf6cc->mf6cc_mcastgrp.sin6_addr, bdst,
                            sizeof(bdst)), mifi, ifp->if_xname);
                        mrt6_mcast_del(rt, rtableid);
                        rtfree(rt);
                        continue;
                }

                /* Route exists, look for changes. */
                if (rt != NULL) {
                        mf6c = (struct mf6c *)rt->rt_llinfo;
                        /* Skip route being deleted. */
                        if (mf6c == NULL) {
                                rtfree(rt);
                                continue;
                        }

                        /* No new changes to apply. */
                        if (mf6cc->mf6cc_parent == mf6c->mf6c_parent) {
                                rtfree(rt);
                                continue;
                        }

                        DPRINTF("update route (group %s) for mif %d (%s)",
                            inet_ntop(AF_INET6,
                            &mf6cc->mf6cc_mcastgrp.sin6_addr, bdst,
                            sizeof(bdst)), mifi, ifp->if_xname);

                        mf6c->mf6c_parent = mf6cc->mf6cc_parent;
                        rtfree(rt);
                        continue;
                }

                DPRINTF("add route (group %s) for mif %d (%s)",
                    inet_ntop(AF_INET6, &mf6cc->mf6cc_mcastgrp.sin6_addr,
                    bdst, sizeof(bdst)), mifi, ifp->if_xname);

                mf6c_add_route(ifp, sin6tosa(&osin6), sin6tosa(&gsin6),
                    mf6cc, wait);
        }

        /* Create route for the parent interface. */
        if ((ifp = mrt6_iflookupbymif(mf6cc->mf6cc_parent,
            rtableid)) == NULL) {
                DPRINTF("failed to find upstream interface %d",
                    mf6cc->mf6cc_parent);
                return;
        }

        /* We already have a route, nothing to do here. */
        if ((rt = mf6c_find(ifp, &mf6cc->mf6cc_mcastgrp.sin6_addr,
            rtableid)) != NULL) {
                rtfree(rt);
                return;
        }

        DPRINTF("add upstream route (group %s) for if %s",
            inet_ntop(AF_INET6, &mf6cc->mf6cc_mcastgrp.sin6_addr,
            bdst, sizeof(bdst)), ifp->if_xname);
        mf6c_add_route(ifp, sin6tosa(&osin6), sin6tosa(&gsin6), mf6cc, wait);
}

int
mf6c_add(struct mf6cctl *mfccp, struct in6_addr *origin,
    struct in6_addr *group, int vidx, unsigned int rtableid, int wait)
{
        struct ifnet *ifp;
        struct mif6 *m6;
        struct mf6cctl mf6cc;

        ifp = mrt6_iflookupbymif(vidx, rtableid);
        if (ifp == NULL ||
            (m6 = (struct mif6 *)ifp->if_mcast6) == NULL)
                return ENOENT;

        memset(&mf6cc, 0, sizeof(mf6cc));
        if (mfccp == NULL) {
                mf6cc.mf6cc_origin.sin6_family = AF_INET6;
                mf6cc.mf6cc_origin.sin6_len = sizeof(mf6cc.mf6cc_origin);
                mf6cc.mf6cc_origin.sin6_addr = *origin;
                mf6cc.mf6cc_mcastgrp.sin6_family = AF_INET6;
                mf6cc.mf6cc_mcastgrp.sin6_len = sizeof(mf6cc.mf6cc_mcastgrp);
                mf6cc.mf6cc_mcastgrp.sin6_addr = *group;
                mf6cc.mf6cc_parent = vidx;
        } else
                memcpy(&mf6cc, mfccp, sizeof(mf6cc));

        mf6c_update(&mf6cc, wait, rtableid);

        return 0;
}

int
add_m6fc(struct socket *so, struct mf6cctl *mfccp)
{
        struct inpcb *inp = sotoinpcb(so);
        unsigned int rtableid = inp->inp_rtableid;

        NET_ASSERT_LOCKED();

        return mf6c_add(mfccp, &mfccp->mf6cc_origin.sin6_addr,
            &mfccp->mf6cc_mcastgrp.sin6_addr, mfccp->mf6cc_parent,
            rtableid, M_WAITOK);
}

int
del_m6fc(struct socket *so, struct mf6cctl *mfccp)
{
        struct inpcb *inp = sotoinpcb(so);
        struct rtentry *rt;
        unsigned int rtableid = inp->inp_rtableid;

        NET_ASSERT_LOCKED();

        while ((rt = mf6c_find(NULL, &mfccp->mf6cc_mcastgrp.sin6_addr,
            rtableid)) != NULL) {
                mrt6_mcast_del(rt, rtableid);
                rtfree(rt);
        }

        return 0;
}

int
socket6_send(struct socket *so, struct mbuf *mm, struct sockaddr_in6 *src)
{
        if (so != NULL) {
                int ret;

                mtx_enter(&so->so_rcv.sb_mtx);
                ret = sbappendaddr(&so->so_rcv, sin6tosa(src), mm, NULL);
                mtx_leave(&so->so_rcv.sb_mtx);

                if (ret != 0) {
                        sorwakeup(so);
                        return 0;
                }
        }
        m_freem(mm);
        return -1;
}

/*
 * IPv6 multicast forwarding function. This function assumes that the packet
 * pointed to by "ip6" has arrived on (or is about to be sent to) the interface
 * pointed to by "ifp", and the packet is to be relayed to other networks
 * that have members of the packet's destination IPv6 multicast group.
 *
 * The packet is returned unscathed to the caller, unless it is
 * erroneous, in which case a non-zero return value tells the caller to
 * discard it.
 */
int
ip6_mforward(struct ip6_hdr *ip6, struct ifnet *ifp, struct mbuf *m, int flags)
{
        struct rtentry *rt;
        struct mif6 *mifp;
        struct mbuf *mm;
        struct sockaddr_in6 sin6;
        unsigned int rtableid = ifp->if_rdomain;

        NET_ASSERT_LOCKED();

        /*
         * Don't forward a packet with Hop limit of zero or one,
         * or a packet destined to a local-only group.
         */
        if (ip6->ip6_hlim <= 1 || IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) ||
            IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
                return 0;
        ip6->ip6_hlim--;

        /*
         * Source address check: do not forward packets with unspecified
         * source. It was discussed in July 2000, on ipngwg mailing list.
         * This is rather more serious than unicast cases, because some
         * MLD packets can be sent with the unspecified source address
         * (although such packets must normally set 1 to the hop limit field).
         */
        if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) {
                ip6stat_inc(ip6s_cantforward);
                return 0;
        }

        /*
         * Determine forwarding mifs from the forwarding cache table
         */
        mrt6stat_inc(mrt6s_mfc_lookups);
        rt = mf6c_find(NULL, &ip6->ip6_dst, rtableid);

        /* Entry exists, so forward if necessary */
        if (rt) {
                return (ip6_mdq(m, ifp, rt, flags));
        } else {
                /*
                 * If we don't have a route for packet's origin,
                 * Make a copy of the packet &
                 * send message to routing daemon
                 */

                mrt6stat_inc(mrt6s_mfc_misses);
                mrt6stat_inc(mrt6s_no_route);

                {
                        struct mrt6msg *im;

                        if ((mifp = (struct mif6 *)ifp->if_mcast6) == NULL)
                                return EHOSTUNREACH;

                        /*
                         * Make a copy of the header to send to the user
                         * level process
                         */
                        mm = m_copym(m, 0, sizeof(struct ip6_hdr), M_NOWAIT);
                        if (mm == NULL)
                                return ENOBUFS;

                        /*
                         * Send message to routing daemon
                         */
                        (void)memset(&sin6, 0, sizeof(sin6));
                        sin6.sin6_len = sizeof(sin6);
                        sin6.sin6_family = AF_INET6;
                        sin6.sin6_addr = ip6->ip6_src;

                        im = NULL;
                        switch (ip6_mrouter_ver) {
                        case MRT6_INIT:
                                im = mtod(mm, struct mrt6msg *);
                                im->im6_msgtype = MRT6MSG_NOCACHE;
                                im->im6_mbz = 0;
                                im->im6_mif = mifp->m6_mifi;
                                break;
                        default:
                                m_freem(mm);
                                return EINVAL;
                        }

                        if (socket6_send(ip6_mrouter[rtableid], mm,
                            &sin6) < 0) {
                                log(LOG_WARNING, "ip6_mforward: ip6_mrouter "
                                    "socket queue full\n");
                                mrt6stat_inc(mrt6s_upq_sockfull);
                                return ENOBUFS;
                        }

                        mrt6stat_inc(mrt6s_upcalls);

                        mf6c_add(NULL, &ip6->ip6_src, &ip6->ip6_dst,
                            mifp->m6_mifi, rtableid, M_NOWAIT);
                }

                return 0;
        }
}

void
mf6c_expire_route(struct rtentry *rt, u_int rtableid)
{
        struct mf6c *mf6c = (struct mf6c *)rt->rt_llinfo;
#ifdef MCAST_DEBUG
        char bsrc[INET6_ADDRSTRLEN], bdst[INET6_ADDRSTRLEN];
#endif /* MCAST_DEBUG */

        /* Skip entry being deleted. */
        if (mf6c == NULL)
                return;

        DPRINTF("origin %s group %s interface %d expire %s",
            inet_ntop(AF_INET6, &satosin6(rt->rt_gateway)->sin6_addr,
            bsrc, sizeof(bsrc)),
            inet_ntop(AF_INET6, &satosin6(rt_key(rt))->sin6_addr,
            bdst, sizeof(bdst)), rt->rt_ifidx,
            mf6c->mf6c_expire ? "yes" : "no");

        if (mf6c->mf6c_expire == 0) {
                mf6c->mf6c_expire = 1;
                rt_timer_add(rt, &ip6_mrouterq, rtableid);
                return;
        }

        mrt6_mcast_del(rt, rtableid);
}

/*
 * Packet forwarding routine once entry in the cache is made
 */
int
ip6_mdq(struct mbuf *m, struct ifnet *ifp, struct rtentry *rt, int flags)
{
        struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
        struct mif6 *m6, *mifp = (struct mif6 *)ifp->if_mcast6;
        struct mf6c *mf6c = (struct mf6c *)rt->rt_llinfo;
        struct ifnet *ifn;
        int plen = m->m_pkthdr.len, ip6_mcast_pmtu_local;

        if (mifp == NULL || mf6c == NULL) {
                rtfree(rt);
                return EHOSTUNREACH;
        }

        /*
         * Don't forward if it didn't arrive from the parent mif
         * for its origin.
         */
        if (mifp->m6_mifi != mf6c->mf6c_parent) {
                /* came in the wrong interface */
                mrt6stat_inc(mrt6s_wrong_if);
                mf6c->mf6c_wrong_if++;
                rtfree(rt);
                return 0;
        }                       /* if wrong iif */

        /* If I sourced this packet, it counts as output, else it was input. */
        if (m->m_pkthdr.ph_ifidx == 0) {
                /* XXX: is ph_ifidx really 0 when output?? */
                mifp->m6_pkt_out++;
                mifp->m6_bytes_out += plen;
        } else {
                mifp->m6_pkt_in++;
                mifp->m6_bytes_in += plen;
        }

        /*
         * For each mif, forward a copy of the packet if there are group
         * members downstream on the interface.
         */
        ip6_mcast_pmtu_local = atomic_load_int(&ip6_mcast_pmtu);

        do {
                /* Don't consider non multicast routes. */
                if (ISSET(rt->rt_flags, RTF_HOST | RTF_MULTICAST) !=
                    (RTF_HOST | RTF_MULTICAST))
                        continue;

                mf6c = (struct mf6c *)rt->rt_llinfo;
                if (mf6c == NULL)
                        continue;

                mf6c->mf6c_pkt_cnt++;
                mf6c->mf6c_byte_cnt += m->m_pkthdr.len;

                /* Don't let this route expire. */
                mf6c->mf6c_expire = 0;

                if ((ifn = if_get(rt->rt_ifidx)) == NULL)
                        continue;

                /* Sanity check: did we configure this? */
                if ((m6 = (struct mif6 *)ifn->if_mcast6) == NULL) {
                        if_put(ifn);
                        continue;
                }

                /* Don't send in the upstream interface. */
                if (mf6c->mf6c_parent == m6->m6_mifi) {
                        if_put(ifn);
                        continue;
                }

                /*
                 * check if the outgoing packet is going to break
                 * a scope boundary.
                 */
                if ((mifp->m6_flags & MIFF_REGISTER) == 0 &&
                    (m6->m6_flags & MIFF_REGISTER) == 0 &&
                    (in6_addr2scopeid(ifp->if_index, &ip6->ip6_dst) !=
                    in6_addr2scopeid(ifn->if_index, &ip6->ip6_dst) ||
                    in6_addr2scopeid(ifp->if_index, &ip6->ip6_src) !=
                    in6_addr2scopeid(ifn->if_index, &ip6->ip6_src))) {
                        if_put(ifn);
                        ip6stat_inc(ip6s_badscope);
                        continue;
                }

                m6->m6_pkt_out++;
                m6->m6_bytes_out += plen;

                phyint_send6(ifn, ip6, m, flags, ip6_mcast_pmtu_local);
                if_put(ifn);
        } while ((rt = rtable_iterate(rt)) != NULL);

        return 0;
}

void
phyint_send6(struct ifnet *ifp, struct ip6_hdr *ip6, struct mbuf *m,
    int flags, int mcast_pmtu)
{
        struct mbuf *mb_copy;
        struct sockaddr_in6 *dst6, sin6;
        int error = 0;

        NET_ASSERT_LOCKED();

        /*
         * Make a new reference to the packet; make sure that
         * the IPv6 header is actually copied, not just referenced,
         * so that ip6_output() only scribbles on the copy.
         */
        mb_copy = m_dup_pkt(m, max_linkhdr, M_NOWAIT);
        if (mb_copy == NULL)
                return;
        /* set MCAST flag to the outgoing packet */
        mb_copy->m_flags |= M_MCAST;

        /*
         * If we sourced the packet, call ip6_output since we may divide
         * the packet into fragments when the packet is too big for the
         * outgoing interface.
         * Otherwise, we can simply send the packet to the interface
         * sending queue.
         */
        if (m->m_pkthdr.ph_ifidx == 0) {
                struct ip6_moptions im6o;

                im6o.im6o_ifidx = ifp->if_index;
                /* XXX: ip6_output will override ip6->ip6_hlim */
                im6o.im6o_hlim = ip6->ip6_hlim;
                im6o.im6o_loop = 1;
                error = ip6_output(mb_copy, NULL, NULL, flags | IPV6_FORWARDING,
                    &im6o, NULL);
                return;
        }

        /*
         * If we belong to the destination multicast group
         * on the outgoing interface, loop back a copy.
         */
        dst6 = &sin6;
        memset(&sin6, 0, sizeof(sin6));
        if (in6_hasmulti(&ip6->ip6_dst, ifp)) {
                dst6->sin6_len = sizeof(struct sockaddr_in6);
                dst6->sin6_family = AF_INET6;
                dst6->sin6_addr = ip6->ip6_dst;
                ip6_mloopback(ifp, m, dst6);
        }
        /*
         * Put the packet into the sending queue of the outgoing interface
         * if it would fit in the MTU of the interface.
         */
        if (mb_copy->m_pkthdr.len <= ifp->if_mtu || ifp->if_mtu < IPV6_MMTU) {
                dst6->sin6_len = sizeof(struct sockaddr_in6);
                dst6->sin6_family = AF_INET6;
                dst6->sin6_addr = ip6->ip6_dst;
                error = ifp->if_output(ifp, mb_copy, sin6tosa(dst6), NULL);
        } else {
                if (mcast_pmtu)
                        icmp6_error(mb_copy, ICMP6_PACKET_TOO_BIG, 0,
                            ifp->if_mtu);
                else {
                        m_freem(mb_copy); /* simply discard the packet */
                }
        }
}

struct ifnet *
mrt6_iflookupbymif(mifi_t mifi, unsigned int rtableid)
{
        struct mif6     *m6;
        struct ifnet    *ifp;

        NET_ASSERT_LOCKED();

        TAILQ_FOREACH(ifp, &ifnetlist, if_list) {
                if (ifp->if_rdomain != rtableid)
                        continue;
                if ((m6 = (struct mif6 *)ifp->if_mcast6) == NULL)
                        continue;
                if (m6->m6_mifi != mifi)
                        continue;

                return ifp;
        }

        return NULL;
}

struct rtentry *
mf6c_find(struct ifnet *ifp, struct in6_addr *group, unsigned int rtableid)
{
        struct rtentry *rt;
        struct sockaddr_in6 msin6;

        memset(&msin6, 0, sizeof(msin6));
        msin6.sin6_family = AF_INET6;
        msin6.sin6_len = sizeof(msin6);
        msin6.sin6_addr = *group;

        rt = rtalloc(sin6tosa(&msin6), 0, rtableid);
        do {
                if (!rtisvalid(rt)) {
                        rtfree(rt);
                        return NULL;
                }
                if (ISSET(rt->rt_flags, RTF_HOST | RTF_MULTICAST) !=
                    (RTF_HOST | RTF_MULTICAST))
                        continue;
                /* Return first occurrence if interface is not specified. */
                if (ifp == NULL)
                        return rt;
                if (rt->rt_ifidx == ifp->if_index)
                        return rt;
        } while ((rt = rtable_iterate(rt)) != NULL);

        return NULL;
}

struct rtentry *
mrt6_mcast_add(struct ifnet *ifp, struct sockaddr *group)
{
        struct ifaddr *ifa;
        int rv;
        unsigned int rtableid = ifp->if_rdomain;

        TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
                if (ifa->ifa_addr->sa_family == AF_INET6)
                        break;
        }
        if (ifa == NULL) {
                DPRINTF("ifa == NULL");
                return NULL;
        }

        rv = rt_ifa_add(ifa, RTF_HOST | RTF_MULTICAST | RTF_MPATH, group,
            ifp->if_rdomain);
        if (rv != 0) {
                DPRINTF("rt_ifa_add failed %d", rv);
                return NULL;
        }

        return mf6c_find(ifp, &satosin6(group)->sin6_addr, rtableid);
}

void
mrt6_mcast_del(struct rtentry *rt, unsigned int rtableid)
{
        struct ifnet *ifp;
        int error;

        /* Remove all timers related to this route. */
        rt_timer_remove_all(rt);

        free(rt->rt_llinfo, M_MRTABLE, sizeof(struct mf6c));
        rt->rt_llinfo = NULL;

        ifp = if_get(rt->rt_ifidx);
        if (ifp == NULL)
                return;
        error = rtdeletemsg(rt, ifp, rtableid);
        if_put(ifp);

        if (error)
                DPRINTF("delete route error %d\n", error);
}