/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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.
 *
 *      $KAME: ip6_mroute.c,v 1.58 2001/12/18 02:36:31 itojun 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.
 *      BSDI ip_mroute.c,v 2.10 1996/11/14 00:29:52 jch Exp
 */

/*
 * 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 + PIM-SMv2 (pimd) Support
 */

#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/callout.h>
#include <sys/errno.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/domain.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/sdt.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/time.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/vnet.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/icmp6.h>
#include <netinet/ip_encap.h>

#include <netinet/ip6.h>
#include <netinet/in_kdtrace.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/ip6_mroute.h>
#include <netinet6/pim6.h>
#include <netinet6/pim6_var.h>

static MALLOC_DEFINE(M_MRTABLE6, "mf6c", "multicast forwarding cache entry");

struct mf6ctable;

static int      ip6_mdq(struct mf6ctable *, struct mbuf *, struct ifnet *,
                    struct mf6c *);
static void     phyint_send(struct ip6_hdr *, struct mif6 *, struct mbuf *);
static int      register_send(struct mf6ctable *, struct ip6_hdr *, mifi_t,
                    struct mbuf *);
static int      set_pim6(int *);
static int      socket_send(struct socket *, struct mbuf *,
                    struct sockaddr_in6 *);

extern int in6_mcast_loop;
extern struct domain inet6domain;

static const struct encaptab *pim6_encap_cookie;
static int pim6_encapcheck(const struct mbuf *, int, int, void *);
static int pim6_input(struct mbuf *, int, int, void *);

static const struct encap_config ipv6_encap_cfg = {
        .proto = IPPROTO_PIM,
        .min_length = sizeof(struct ip6_hdr) + PIM_MINLEN,
        .exact_match = 8,
        .check = pim6_encapcheck,
        .input = pim6_input
};

SYSCTL_DECL(_net_inet6);
SYSCTL_DECL(_net_inet6_ip6);
static SYSCTL_NODE(_net_inet6, IPPROTO_PIM, pim,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "PIM");

VNET_DEFINE_STATIC(struct mrt6stat, mrt6stat);
#define V_mrt6stat      VNET(mrt6stat)
SYSCTL_STRUCT(_net_inet6_ip6, OID_AUTO, mrt6stat, CTLFLAG_VNET | CTLFLAG_RW,
    &VNET_NAME(mrt6stat), mrt6stat,
    "Multicast Routing Statistics (struct mrt6stat, netinet6/ip6_mroute.h)");

#define MRT6STAT_INC(name)      V_mrt6stat.name += 1
#define NO_RTE_FOUND    0x1
#define RTE_FOUND       0x2

static struct sx mrouter6_mtx;
#define MROUTER6_LOCKPTR()      (&mrouter6_mtx)
#define MROUTER6_LOCK()         sx_xlock(MROUTER6_LOCKPTR())
#define MROUTER6_UNLOCK()       sx_xunlock(MROUTER6_LOCKPTR())
#define MROUTER6_LOCK_ASSERT()  sx_assert(MROUTER6_LOCKPTR(), SA_XLOCKED
#define MROUTER6_LOCK_INIT()    sx_init(MROUTER6_LOCKPTR(), "mrouter6")
#define MROUTER6_LOCK_DESTROY() sx_destroy(MROUTER6_LOCKPTR())

static struct mtx mfc6_mtx;
#define MFC6_LOCKPTR()          (&mfc6_mtx)
#define MFC6_LOCK()             mtx_lock(MFC6_LOCKPTR())
#define MFC6_UNLOCK()           mtx_unlock(MFC6_LOCKPTR())
#define MFC6_LOCK_ASSERT()      mtx_assert(MFC6_LOCKPTR(), MA_OWNED)
#define MFC6_LOCK_INIT()        mtx_init(MFC6_LOCKPTR(),                \
                                    "IPv6 multicast forwarding cache",  \
                                    NULL, MTX_DEF)
#define MFC6_LOCK_DESTROY()     mtx_destroy(MFC6_LOCKPTR())

struct mf6ctable {
        struct socket   *router;
        int             router_ver;
        struct mf6c     *mfchashtbl[MF6CTBLSIZ];
        u_char          nexpire[MF6CTBLSIZ];
        int             nummifs;
        struct mif6     miftable[MAXMIFS];

        /*
         * 'Interfaces' associated with decapsulator (so we can tell packets
         * that went through it from ones that get reflected by a broken
         * gateway).  Different from IPv4 register_if, these interfaces are
         * linked into the system ifnet list, because per-interface IPv6
         * statistics are maintained in ifp->if_afdata.  But it does not have
         * any routes point to them.  I.e., packets can't be sent this way.
         * They only exist as a placeholder for multicast source verification.
         */
        struct ifnet    *register_if;
        mifi_t          register_mif;
};

VNET_DEFINE_STATIC(struct mf6ctable *, mfctables);
#define V_mfctables             VNET(mfctables)
VNET_DEFINE_STATIC(uint32_t, nmfctables);
#define V_nmfctables            VNET(nmfctables)

static eventhandler_tag ifdetach_tag, rtnumfibs_change_tag;

static int
sysctl_mfctable(SYSCTL_HANDLER_ARGS)
{
        int fibnum;

        fibnum = curthread->td_proc->p_fibnum;
        return (SYSCTL_OUT(req, &V_mfctables[fibnum].mfchashtbl,
            sizeof(struct mf6c *) * MF6CTBLSIZ));
}
SYSCTL_PROC(_net_inet6_ip6, OID_AUTO, mf6ctable,
    CTLTYPE_OPAQUE | CTLFLAG_RD,
    NULL, 0, sysctl_mfctable, "S,*mf6c[MF6CTBLSIZ]",
    "IPv6 Multicast Forwarding Table (struct mf6c *[MF6CTBLSIZ], "
    "netinet6/ip6_mroute.h)");

static int
sysctl_mif6table(SYSCTL_HANDLER_ARGS)
{
        struct mif6_sctl *out;
        struct mf6ctable *mfct;
        int error;

        mfct = &V_mfctables[curthread->td_proc->p_fibnum];
        out = malloc(sizeof(struct mif6_sctl) * MAXMIFS, M_TEMP,
            M_WAITOK | M_ZERO);
        for (int i = 0; i < MAXMIFS; i++) {
                struct mif6_sctl *outp = &out[i];
                struct mif6 *mifp = &mfct->miftable[i];

                outp->m6_flags = mifp->m6_flags;
                outp->m6_rate_limit = mifp->m6_rate_limit;
                outp->m6_lcl_addr = mifp->m6_lcl_addr;
                if (mifp->m6_ifp != NULL)
                        outp->m6_ifp = mifp->m6_ifp->if_index;
                else
                        outp->m6_ifp = 0;
                outp->m6_pkt_in = mifp->m6_pkt_in;
                outp->m6_pkt_out = mifp->m6_pkt_out;
                outp->m6_bytes_in = mifp->m6_bytes_in;
                outp->m6_bytes_out = mifp->m6_bytes_out;
        }
        error = SYSCTL_OUT(req, out, sizeof(struct mif6_sctl) * MAXMIFS);
        free(out, M_TEMP);
        return (error);
}
SYSCTL_PROC(_net_inet6_ip6, OID_AUTO, mif6table,
    CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
    NULL, 0, sysctl_mif6table, "S,mif6_sctl[MAXMIFS]",
    "IPv6 Multicast Interfaces (struct mif6_sctl[MAXMIFS], "
    "netinet6/ip6_mroute.h)");

static struct mtx mif6_mtx;
#define MIF6_LOCKPTR()          (&mif6_mtx)
#define MIF6_LOCK()             mtx_lock(MIF6_LOCKPTR())
#define MIF6_UNLOCK()           mtx_unlock(MIF6_LOCKPTR())
#define MIF6_LOCK_ASSERT()      mtx_assert(MIF6_LOCKPTR(), MA_OWNED)
#define MIF6_LOCK_INIT()        \
        mtx_init(MIF6_LOCKPTR(), "IPv6 multicast interfaces", NULL, MTX_DEF)
#define MIF6_LOCK_DESTROY()     mtx_destroy(MIF6_LOCKPTR())

#ifdef MRT6DEBUG
VNET_DEFINE_STATIC(u_int, mrt6debug) = 0;       /* debug level */
#define V_mrt6debug             VNET(mrt6debug)
#define DEBUG_MFC       0x02
#define DEBUG_FORWARD   0x04
#define DEBUG_EXPIRE    0x08
#define DEBUG_XMIT      0x10
#define DEBUG_REG       0x20
#define DEBUG_PIM       0x40
#define DEBUG_ERR       0x80
#define DEBUG_ANY       0x7f
#define MRT6_DLOG(m, fmt, ...)  \
        if (V_mrt6debug & (m))  \
                log(((m) & DEBUG_ERR) ? LOG_ERR: LOG_DEBUG, \
                    "%s: " fmt "\n", __func__, ##__VA_ARGS__)
#else
#define MRT6_DLOG(m, fmt, ...)
#endif

static void     expire_upcalls(struct mf6ctable *);
static void     expire_upcalls_all(void *);
#define EXPIRE_TIMEOUT  (hz / 4)        /* 4x / second */
#define UPCALL_EXPIRE   6               /* number of timeouts */

VNET_DEFINE_STATIC(struct pim6stat, pim6stat);
#define V_pim6stat      VNET(pim6stat)
SYSCTL_STRUCT(_net_inet6_pim, PIM6CTL_STATS, stats, CTLFLAG_VNET | CTLFLAG_RW,
    &VNET_NAME(pim6stat), pim6stat,
    "PIM Statistics (struct pim6stat, netinet6/pim6_var.h)");

#define PIM6STAT_INC(name)      V_pim6stat.name += 1
VNET_DEFINE_STATIC(int, pim6);
#define V_pim6          VNET(pim6)

/*
 * Hash function for a source, group entry
 */
#define MF6CHASH(a, g) MF6CHASHMOD((a).s6_addr32[0] ^ (a).s6_addr32[1] ^ \
                                   (a).s6_addr32[2] ^ (a).s6_addr32[3] ^ \
                                   (g).s6_addr32[0] ^ (g).s6_addr32[1] ^ \
                                   (g).s6_addr32[2] ^ (g).s6_addr32[3])

/*
 * Macros to compute elapsed time efficiently
 * Borrowed from Van Jacobson's scheduling code
 * XXX: replace with timersub() ?
 */
#define TV_DELTA(a, b, delta) do { \
            int xxs; \
                \
            delta = (a).tv_usec - (b).tv_usec; \
            if ((xxs = (a).tv_sec - (b).tv_sec)) { \
               switch (xxs) { \
                      case 2: \
                          delta += 1000000; \
                              /* FALLTHROUGH */ \
                      case 1: \
                          delta += 1000000; \
                          break; \
                      default: \
                          delta += (1000000 * xxs); \
               } \
            } \
} while (/*CONSTCOND*/ 0)

/* XXX: replace with timercmp(a, b, <) ? */
#define TV_LT(a, b) (((a).tv_usec < (b).tv_usec && \
              (a).tv_sec <= (b).tv_sec) || (a).tv_sec < (b).tv_sec)

#ifdef UPCALL_TIMING
#define UPCALL_MAX      50
static u_long upcall_data[UPCALL_MAX + 1];
static void collate(struct timeval *);
#endif /* UPCALL_TIMING */

static int ip6_mrouter_init(struct socket *, int, int);
static int add_m6fc(struct mf6ctable *, struct mf6cctl *);
static int add_m6if(struct mf6ctable *, int, struct mif6ctl *);
static int del_m6fc(struct mf6ctable *, struct mf6cctl *);
static int del_m6if(struct mf6ctable *, mifi_t);
static int del_m6if_locked(struct mf6ctable *, mifi_t);
static int get_mif6_cnt(struct mf6ctable *, struct sioc_mif_req6 *);
static int get_sg_cnt(struct mf6ctable *, struct sioc_sg_req6 *);

VNET_DEFINE_STATIC(struct callout, expire_upcalls_ch);
#define V_expire_upcalls_ch     VNET(expire_upcalls_ch)

static int X_ip6_mforward(struct ip6_hdr *, struct ifnet *, struct mbuf *);
static void X_ip6_mrouter_done(struct socket *);
static int X_ip6_mrouter_set(struct socket *, struct sockopt *);
static int X_ip6_mrouter_get(struct socket *, struct sockopt *);
static int X_mrt6_ioctl(u_long, caddr_t, int);

static struct mf6c *
mf6c_find(const struct mf6ctable *mfct, const struct in6_addr *origin,
    const struct in6_addr *group)
{
        MFC6_LOCK_ASSERT();

        for (struct mf6c *rt = mfct->mfchashtbl[MF6CHASH(*origin, *group)];
            rt != NULL; rt = rt->mf6c_next) {
                if (IN6_ARE_ADDR_EQUAL(&rt->mf6c_origin.sin6_addr, origin) &&
                    IN6_ARE_ADDR_EQUAL(&rt->mf6c_mcastgrp.sin6_addr, group) &&
                    rt->mf6c_stall == NULL)
                        return (rt);
        }
        MRT6STAT_INC(mrt6s_mfc_misses);
        return (NULL);
}

static struct mf6ctable *
somfctable(struct socket *so)
{
        int fib;

        fib = atomic_load_int(&so->so_fibnum);
        KASSERT(fib >= 0 && fib < V_nmfctables,
            ("%s: so_fibnum %d out of range", __func__, fib));
        return (&V_mfctables[fib]);
}

/*
 * Handle MRT setsockopt commands to modify the multicast routing tables.
 */
static int
X_ip6_mrouter_set(struct socket *so, struct sockopt *sopt)
{
        struct mf6ctable *mfct;
        int error = 0;
        int optval;
        struct mif6ctl mifc;
        struct mf6cctl mfcc;
        mifi_t mifi;

        mfct = somfctable(so);
        if (so != mfct->router && sopt->sopt_name != MRT6_INIT)
                return (EPERM);

        switch (sopt->sopt_name) {
        case MRT6_INIT:
#ifdef MRT6_OINIT
        case MRT6_OINIT:
#endif
                error = sooptcopyin(sopt, &optval, sizeof(optval),
                    sizeof(optval));
                if (error)
                        break;
                error = ip6_mrouter_init(so, optval, sopt->sopt_name);
                break;
        case MRT6_DONE:
                X_ip6_mrouter_done(so);
                break;
        case MRT6_ADD_MIF:
                error = sooptcopyin(sopt, &mifc, sizeof(mifc), sizeof(mifc));
                if (error)
                        break;
                error = add_m6if(mfct, so->so_fibnum, &mifc);
                break;
        case MRT6_ADD_MFC:
                error = sooptcopyin(sopt, &mfcc, sizeof(mfcc), sizeof(mfcc));
                if (error)
                        break;
                error = add_m6fc(mfct, &mfcc);
                break;
        case MRT6_DEL_MFC:
                error = sooptcopyin(sopt, &mfcc, sizeof(mfcc), sizeof(mfcc));
                if (error)
                        break;
                error = del_m6fc(mfct, &mfcc);
                break;
        case MRT6_DEL_MIF:
                error = sooptcopyin(sopt, &mifi, sizeof(mifi), sizeof(mifi));
                if (error)
                        break;
                error = del_m6if(mfct, mifi);
                break;
        case MRT6_PIM:
                error = sooptcopyin(sopt, &optval, sizeof(optval),
                    sizeof(optval));
                if (error)
                        break;
                error = set_pim6(&optval);
                break;
        default:
                error = EOPNOTSUPP;
                break;
        }

        return (error);
}

/*
 * Handle MRT getsockopt commands
 */
static int
X_ip6_mrouter_get(struct socket *so, struct sockopt *sopt)
{
        struct mf6ctable *mfct;
        int error = 0;

        mfct = somfctable(so);
        if (so != mfct->router)
                return (EACCES);

        switch (sopt->sopt_name) {
                case MRT6_PIM:
                        error = sooptcopyout(sopt, &V_pim6, sizeof(V_pim6));
                        break;
        }
        return (error);
}

/*
 * Handle ioctl commands to obtain information from the cache
 */
static int
X_mrt6_ioctl(u_long cmd, caddr_t data, int fibnum)
{
        struct mf6ctable *mfct;
        int error;

        error = priv_check(curthread, PRIV_NETINET_MROUTE);
        if (error)
                return (error);

        mfct = &V_mfctables[fibnum];
        switch (cmd) {
        case SIOCGETSGCNT_IN6:
                error = get_sg_cnt(mfct, (struct sioc_sg_req6 *)data);
                break;

        case SIOCGETMIFCNT_IN6:
                error = get_mif6_cnt(mfct, (struct sioc_mif_req6 *)data);
                break;

        default:
                error = EINVAL;
                break;
        }

        return (error);
}

/*
 * returns the packet, byte, rpf-failure count for the source group provided
 */
static int
get_sg_cnt(struct mf6ctable *mfct, struct sioc_sg_req6 *req)
{
        struct mf6c *rt;
        int ret;

        ret = 0;

        MFC6_LOCK();
        rt = mf6c_find(mfct, &req->src.sin6_addr, &req->grp.sin6_addr);
        if (rt == NULL) {
                ret = ESRCH;
        } else {
                req->pktcnt = rt->mf6c_pkt_cnt;
                req->bytecnt = rt->mf6c_byte_cnt;
                req->wrong_if = rt->mf6c_wrong_if;
        }
        MFC6_UNLOCK();

        return (ret);
}

/*
 * returns the input and output packet and byte counts on the mif provided
 */
static int
get_mif6_cnt(struct mf6ctable *mfct, struct sioc_mif_req6 *req)
{
        mifi_t mifi;
        int ret;

        ret = 0;
        mifi = req->mifi;

        MIF6_LOCK();

        if (mifi >= mfct->nummifs) {
                ret = EINVAL;
        } else {
                struct mif6 *mif = &mfct->miftable[mifi];

                req->icount = mif->m6_pkt_in;
                req->ocount = mif->m6_pkt_out;
                req->ibytes = mif->m6_bytes_in;
                req->obytes = mif->m6_bytes_out;
        }

        MIF6_UNLOCK();

        return (ret);
}

static int
set_pim6(int *i)
{
        if ((*i != 1) && (*i != 0))
                return (EINVAL);

        /* XXX-MJ */
        V_pim6 = *i;

        return (0);
}

/*
 * Enable multicast routing
 */
static int
ip6_mrouter_init(struct socket *so, int v, int cmd)
{
        struct mf6ctable *mfct;

        MRT6_DLOG(DEBUG_ANY, "%s: socket %p", __func__, so);

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

        mfct = somfctable(so);
        MROUTER6_LOCK();

        if (mfct->router != NULL) {
                MROUTER6_UNLOCK();
                return (EADDRINUSE);
        }

        MFC6_LOCK();
        V_ip6_mrouting_enabled = true;
        mfct->router = so;
        mfct->router_ver = cmd;

        bzero(&mfct->mfchashtbl, sizeof(mfct->mfchashtbl));
        bzero(&mfct->nexpire, sizeof(mfct->nexpire));

        V_pim6 = 0;/* used for stubbing out/in pim stuff */

        callout_reset(&V_expire_upcalls_ch, EXPIRE_TIMEOUT, expire_upcalls_all,
            curvnet);

        MFC6_UNLOCK();
        MROUTER6_UNLOCK();

        MRT6_DLOG(DEBUG_ANY, "finished");

        return (0);
}

/*
 * Disable IPv6 multicast forwarding.
 */
static void
X_ip6_mrouter_done(struct socket *so)
{
        struct mf6ctable *mfct;
        mifi_t mifi;
        u_long i;
        struct mf6c *rt;
        struct rtdetq *rte;

        mfct = somfctable(so);
        MROUTER6_LOCK();

        if (mfct->router != so) {
                MROUTER6_UNLOCK();
                return;
        }

        /*
         * For each phyint in use, disable promiscuous reception of all IPv6
         * multicasts.
         */
        for (mifi = 0; mifi < mfct->nummifs; mifi++) {
                struct mif6 *mif = &mfct->miftable[mifi];

                if (mif->m6_ifp && !(mif->m6_flags & MIFF_REGISTER)) {
                        if_allmulti(mif->m6_ifp, 0);
                }
        }
        MFC6_LOCK();
        bzero(mfct->miftable, sizeof(mfct->miftable));
        mfct->nummifs = 0;

        V_pim6 = 0; /* used to stub out/in pim specific code */

        /*
         * Free all multicast forwarding cache entries.
         */
        for (i = 0; i < MF6CTBLSIZ; i++) {
                rt = mfct->mfchashtbl[i];
                while (rt) {
                        struct mf6c *frt;

                        for (rte = rt->mf6c_stall; rte != NULL; ) {
                                struct rtdetq *n = rte->next;

                                m_freem(rte->m);
                                free(rte, M_MRTABLE6);
                                rte = n;
                        }
                        frt = rt;
                        rt = rt->mf6c_next;
                        free(frt, M_MRTABLE6);
                }
        }
        mfct->router = NULL;
        mfct->router_ver = 0;
        V_ip6_mrouting_enabled = false;

        bzero(mfct->mfchashtbl, sizeof(mfct->mfchashtbl));
        MFC6_UNLOCK();

        /*
         * Reset register interface
         */
        if (mfct->register_mif != (mifi_t)-1 && mfct->register_if != NULL) {
                if_detach(mfct->register_if);
                if_free(mfct->register_if);
                mfct->register_mif = (mifi_t)-1;
                mfct->register_if = NULL;
        }

        MROUTER6_UNLOCK();
        MRT6_DLOG(DEBUG_ANY, "finished");
}

static struct sockaddr_in6 sin6 = { sizeof(sin6), AF_INET6 };

/*
 * Add a mif to the mif table
 */
static int
add_m6if(struct mf6ctable *mfct, int fibnum, struct mif6ctl *mifcp)
{
        struct epoch_tracker et;
        struct mif6 *mifp;
        struct ifnet *ifp;
        int error;

        MIF6_LOCK();

        if (mifcp->mif6c_mifi >= MAXMIFS) {
                MIF6_UNLOCK();
                return (EINVAL);
        }
        mifp = &mfct->miftable[mifcp->mif6c_mifi];
        if (mifp->m6_ifp != NULL) {
                MIF6_UNLOCK();
                return (EADDRINUSE); /* XXX: is it appropriate? */
        }

        NET_EPOCH_ENTER(et);
        if ((ifp = ifnet_byindex(mifcp->mif6c_pifi)) == NULL) {
                NET_EPOCH_EXIT(et);
                MIF6_UNLOCK();
                return (ENXIO);
        }
        NET_EPOCH_EXIT(et);     /* XXXGL: unsafe ifp */

        if (mifcp->mif6c_flags & MIFF_REGISTER) {
                if (mfct->register_mif == (mifi_t)-1) {
                        ifp = if_alloc(IFT_OTHER);

                        if_initname(ifp, "register_mif", 0);
                        ifp->if_flags |= IFF_LOOPBACK;
                        if_attach(ifp);
                        mfct->register_if = ifp;
                        mfct->register_mif = mifcp->mif6c_mifi;
                        /*
                         * it is impossible to guess the ifindex of the
                         * register interface.  So mif6c_pifi is automatically
                         * calculated.
                         */
                        mifcp->mif6c_pifi = ifp->if_index;
                } else {
                        ifp = mfct->register_if;
                }
        } else {
                /* Make sure the interface supports multicast */
                if ((ifp->if_flags & IFF_MULTICAST) == 0) {
                        MIF6_UNLOCK();
                        return (EOPNOTSUPP);
                }
                if (ifp->if_fib != fibnum) {
                        MIF6_UNLOCK();
                        return (EADDRNOTAVAIL);
                }

                error = if_allmulti(ifp, 1);
                if (error) {
                        MIF6_UNLOCK();
                        return (error);
                }
        }

        mifp->m6_flags     = mifcp->mif6c_flags;
        mifp->m6_ifp       = ifp;

        /* initialize per mif pkt counters */
        mifp->m6_pkt_in    = 0;
        mifp->m6_pkt_out   = 0;
        mifp->m6_bytes_in  = 0;
        mifp->m6_bytes_out = 0;

        /* Adjust nummifs up if the mifi is higher than nummifs */
        if (mfct->nummifs <= mifcp->mif6c_mifi)
                mfct->nummifs = mifcp->mif6c_mifi + 1;

        MIF6_UNLOCK();
        MRT6_DLOG(DEBUG_ANY, "mif #%d, phyint %s", mifcp->mif6c_mifi,
            if_name(ifp));

        return (0);
}

static void
expire_mf6c(struct mf6c *mfc)
{
        struct rtdetq *rte;

        while ((rte = mfc->mf6c_stall) != NULL) {
                mfc->mf6c_stall = rte->next;
                m_freem(rte->m);
                free(rte, M_MRTABLE6);
        }

        free(mfc, M_MRTABLE6);
}

/*
 * Delete a mif from the mif table
 */
static int
del_m6if_locked(struct mf6ctable *mfct, mifi_t mifi)
{
        struct mif6 *mifp;
        mifi_t tmp;
        struct ifnet *ifp;

        MIF6_LOCK_ASSERT();

        if (mifi >= mfct->nummifs)
                return (EINVAL);
        mifp = &mfct->miftable[mifi];
        if (mifp->m6_ifp == NULL)
                return (EINVAL);

        if (!(mifp->m6_flags & MIFF_REGISTER)) {
                ifp = mifp->m6_ifp;
                if_allmulti(ifp, 0);

                MFC6_LOCK();
                for (int i = 0; i < MF6CTBLSIZ; i++) {
                        struct mf6c *mfc, **nmfc;

                        nmfc = &mfct->mfchashtbl[i];
                        while ((mfc = *nmfc) != NULL) {
                                if (mfc->mf6c_parent == mifi) {
                                        *nmfc = mfc->mf6c_next;
                                        if (mfc->mf6c_expire)
                                                mfct->nexpire[i]--;
                                        expire_mf6c(mfc);
                                } else {
                                        /* Remove this mif from the ifset */
                                        if (IF_ISSET(mifi, &mfc->mf6c_ifset))
                                                IF_CLR(mifi, &mfc->mf6c_ifset);
                                        nmfc = &mfc->mf6c_next;
                                }
                        }
                }
                MFC6_UNLOCK();
        } else {
                if (mfct->register_mif != (mifi_t)-1 &&
                    mfct->register_if != NULL) {
                        if_detach(mfct->register_if);
                        if_free(mfct->register_if);
                        mfct->register_mif = (mifi_t)-1;
                        mfct->register_if = NULL;
                }
        }

        bzero(mifp, sizeof(*mifp));

        /* Adjust nummifs down */
        for (tmp = mfct->nummifs; tmp > 0; tmp--)
                if (mfct->miftable[tmp - 1].m6_ifp != NULL)
                        break;
        mfct->nummifs = tmp;
        MRT6_DLOG(DEBUG_ANY, "mif %d, nummifs %d", mifi, mfct->nummifs);

        return (0);
}

static int
del_m6if(struct mf6ctable *mfct, mifi_t mifi)
{
        int cc;

        MIF6_LOCK();
        cc = del_m6if_locked(mfct, mifi);
        MIF6_UNLOCK();

        return (cc);
}

/*
 * Add an mfc entry
 */
static int
add_m6fc(struct mf6ctable *mfct, struct mf6cctl *mfccp)
{
        struct mf6c *rt;
        u_long hash;
        struct rtdetq *rte;
        u_short nstl;
        char ip6bufo[INET6_ADDRSTRLEN], ip6bufg[INET6_ADDRSTRLEN];

        MFC6_LOCK();
        rt = mf6c_find(mfct, &mfccp->mf6cc_origin.sin6_addr,
            &mfccp->mf6cc_mcastgrp.sin6_addr);
        /* If an entry already exists, just update the fields */
        if (rt) {
                MRT6_DLOG(DEBUG_MFC, "no upcall o %s g %s p %x",
                    ip6_sprintf(ip6bufo, &mfccp->mf6cc_origin.sin6_addr),
                    ip6_sprintf(ip6bufg, &mfccp->mf6cc_mcastgrp.sin6_addr),
                    mfccp->mf6cc_parent);

                rt->mf6c_parent = mfccp->mf6cc_parent;
                rt->mf6c_ifset = mfccp->mf6cc_ifset;

                MFC6_UNLOCK();
                return (0);
        }

        /*
         * Find the entry for which the upcall was made and update
         */
        hash = MF6CHASH(mfccp->mf6cc_origin.sin6_addr,
                        mfccp->mf6cc_mcastgrp.sin6_addr);
        for (rt = mfct->mfchashtbl[hash], nstl = 0; rt; rt = rt->mf6c_next) {
                if (IN6_ARE_ADDR_EQUAL(&rt->mf6c_origin.sin6_addr,
                                       &mfccp->mf6cc_origin.sin6_addr) &&
                    IN6_ARE_ADDR_EQUAL(&rt->mf6c_mcastgrp.sin6_addr,
                                       &mfccp->mf6cc_mcastgrp.sin6_addr) &&
                    (rt->mf6c_stall != NULL)) {
                        if (nstl++)
                                log(LOG_ERR,
                                    "add_m6fc: %s o %s g %s p %x dbx %p\n",
                                    "multiple kernel entries",
                                    ip6_sprintf(ip6bufo,
                                            &mfccp->mf6cc_origin.sin6_addr),
                                    ip6_sprintf(ip6bufg,
                                            &mfccp->mf6cc_mcastgrp.sin6_addr),
                                    mfccp->mf6cc_parent, rt->mf6c_stall);

                        MRT6_DLOG(DEBUG_MFC, "o %s g %s p %x dbg %p",
                            ip6_sprintf(ip6bufo,
                            &mfccp->mf6cc_origin.sin6_addr),
                            ip6_sprintf(ip6bufg,
                                &mfccp->mf6cc_mcastgrp.sin6_addr),
                            mfccp->mf6cc_parent, rt->mf6c_stall);

                        rt->mf6c_origin     = mfccp->mf6cc_origin;
                        rt->mf6c_mcastgrp   = mfccp->mf6cc_mcastgrp;
                        rt->mf6c_parent     = mfccp->mf6cc_parent;
                        rt->mf6c_ifset      = mfccp->mf6cc_ifset;
                        /* initialize pkt counters per src-grp */
                        rt->mf6c_pkt_cnt    = 0;
                        rt->mf6c_byte_cnt   = 0;
                        rt->mf6c_wrong_if   = 0;

                        rt->mf6c_expire = 0;    /* Don't clean this guy up */
                        mfct->nexpire[hash]--;

                        /* free packets Qed at the end of this entry */
                        for (rte = rt->mf6c_stall; rte != NULL; ) {
                                struct rtdetq *n = rte->next;
                                ip6_mdq(mfct, rte->m, rte->ifp, rt);
                                m_freem(rte->m);
#ifdef UPCALL_TIMING
                                collate(&(rte->t));
#endif /* UPCALL_TIMING */
                                free(rte, M_MRTABLE6);
                                rte = n;
                        }
                        rt->mf6c_stall = NULL;
                }
        }

        /*
         * It is possible that an entry is being inserted without an upcall
         */
        if (nstl == 0) {
                MRT6_DLOG(DEBUG_MFC, "no upcall h %lu o %s g %s p %x", hash,
                    ip6_sprintf(ip6bufo, &mfccp->mf6cc_origin.sin6_addr),
                    ip6_sprintf(ip6bufg, &mfccp->mf6cc_mcastgrp.sin6_addr),
                    mfccp->mf6cc_parent);

                for (rt = mfct->mfchashtbl[hash]; rt; rt = rt->mf6c_next) {
                        if (IN6_ARE_ADDR_EQUAL(&rt->mf6c_origin.sin6_addr,
                                               &mfccp->mf6cc_origin.sin6_addr)&&
                            IN6_ARE_ADDR_EQUAL(&rt->mf6c_mcastgrp.sin6_addr,
                                               &mfccp->mf6cc_mcastgrp.sin6_addr)) {
                                rt->mf6c_origin     = mfccp->mf6cc_origin;
                                rt->mf6c_mcastgrp   = mfccp->mf6cc_mcastgrp;
                                rt->mf6c_parent     = mfccp->mf6cc_parent;
                                rt->mf6c_ifset      = mfccp->mf6cc_ifset;
                                /* initialize pkt counters per src-grp */
                                rt->mf6c_pkt_cnt    = 0;
                                rt->mf6c_byte_cnt   = 0;
                                rt->mf6c_wrong_if   = 0;

                                if (rt->mf6c_expire)
                                        mfct->nexpire[hash]--;
                                rt->mf6c_expire    = 0;
                        }
                }
                if (rt == NULL) {
                        /* no upcall, so make a new entry */
                        rt = malloc(sizeof(*rt), M_MRTABLE6, M_NOWAIT);
                        if (rt == NULL) {
                                MFC6_UNLOCK();
                                return (ENOBUFS);
                        }

                        /* insert new entry at head of hash chain */
                        rt->mf6c_origin     = mfccp->mf6cc_origin;
                        rt->mf6c_mcastgrp   = mfccp->mf6cc_mcastgrp;
                        rt->mf6c_parent     = mfccp->mf6cc_parent;
                        rt->mf6c_ifset      = mfccp->mf6cc_ifset;
                        /* initialize pkt counters per src-grp */
                        rt->mf6c_pkt_cnt    = 0;
                        rt->mf6c_byte_cnt   = 0;
                        rt->mf6c_wrong_if   = 0;
                        rt->mf6c_expire     = 0;
                        rt->mf6c_stall = NULL;

                        /* link into table */
                        rt->mf6c_next  = mfct->mfchashtbl[hash];
                        mfct->mfchashtbl[hash] = rt;
                }
        }

        MFC6_UNLOCK();
        return (0);
}

#ifdef UPCALL_TIMING
/*
 * collect delay statistics on the upcalls
 */
static void
collate(struct timeval *t)
{
        u_long d;
        struct timeval tp;
        u_long delta;

        GET_TIME(tp);

        if (TV_LT(*t, tp))
        {
                TV_DELTA(tp, *t, delta);

                d = delta >> 10;
                if (d > UPCALL_MAX)
                        d = UPCALL_MAX;

                ++upcall_data[d];
        }
}
#endif /* UPCALL_TIMING */

/*
 * Delete an mfc entry
 */
static int
del_m6fc(struct mf6ctable *mfct, struct mf6cctl *mfccp)
{
#ifdef MRT6DEBUG
        char ip6bufo[INET6_ADDRSTRLEN], ip6bufg[INET6_ADDRSTRLEN];
#endif
        struct sockaddr_in6     origin;
        struct sockaddr_in6     mcastgrp;
        struct mf6c             *rt;
        struct mf6c             **nptr;
        u_long          hash;

        origin = mfccp->mf6cc_origin;
        mcastgrp = mfccp->mf6cc_mcastgrp;
        hash = MF6CHASH(origin.sin6_addr, mcastgrp.sin6_addr);

        MRT6_DLOG(DEBUG_MFC, "orig %s mcastgrp %s",
            ip6_sprintf(ip6bufo, &origin.sin6_addr),
            ip6_sprintf(ip6bufg, &mcastgrp.sin6_addr));

        MFC6_LOCK();

        nptr = &mfct->mfchashtbl[hash];
        while ((rt = *nptr) != NULL) {
                if (IN6_ARE_ADDR_EQUAL(&origin.sin6_addr,
                                       &rt->mf6c_origin.sin6_addr) &&
                    IN6_ARE_ADDR_EQUAL(&mcastgrp.sin6_addr,
                                       &rt->mf6c_mcastgrp.sin6_addr) &&
                    rt->mf6c_stall == NULL)
                        break;

                nptr = &rt->mf6c_next;
        }
        if (rt == NULL) {
                MFC6_UNLOCK();
                return (EADDRNOTAVAIL);
        }

        *nptr = rt->mf6c_next;
        free(rt, M_MRTABLE6);

        MFC6_UNLOCK();

        return (0);
}

static int
socket_send(struct socket *s, struct mbuf *mm, struct sockaddr_in6 *src)
{

        if (s) {
                if (sbappendaddr(&s->so_rcv,
                                 (struct sockaddr *)src,
                                 mm, (struct mbuf *)0) != 0) {
                        sorwakeup(s);
                        return (0);
                } else
                        soroverflow(s);
        }
        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.
 *
 * NOTE: this implementation assumes that m->m_pkthdr.rcvif is NULL iff
 * this function is called in the originating context (i.e., not when
 * forwarding a packet from other node).  ip6_output(), which is currently the
 * only function that calls this function is called in the originating context,
 * explicitly ensures this condition.  It is caller's responsibility to ensure
 * that if this function is called from somewhere else in the originating
 * context in the future.
 */
static int
X_ip6_mforward(struct ip6_hdr *ip6, struct ifnet *ifp, struct mbuf *m)
{
        struct mf6ctable *mfct;
        struct rtdetq *rte;
        struct mbuf *mb0;
        struct mf6c *rt;
        struct mif6 *mifp;
        struct mbuf *mm;
        u_long hash;
        mifi_t mifi;
        char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
#ifdef UPCALL_TIMING
        struct timeval tp;

        GET_TIME(tp);
#endif /* UPCALL_TIMING */

        M_ASSERTMAPPED(m);
        MRT6_DLOG(DEBUG_FORWARD, "src %s, dst %s, ifindex %d",
            ip6_sprintf(ip6bufs, &ip6->ip6_src),
            ip6_sprintf(ip6bufd, &ip6->ip6_dst), ifp->if_index);

        /*
         * 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);
                if (V_ip6_log_cannot_forward && ip6_log_ratelimit()) {
                        log(LOG_DEBUG,
                            "cannot forward "
                            "from %s to %s nxt %d received on %s\n",
                            ip6_sprintf(ip6bufs, &ip6->ip6_src),
                            ip6_sprintf(ip6bufd, &ip6->ip6_dst),
                            ip6->ip6_nxt,
                            if_name(m->m_pkthdr.rcvif));
                }
                return (0);
        }

        mfct = &V_mfctables[M_GETFIB(m)];
        MFC6_LOCK();

        /*
         * Determine forwarding mifs from the forwarding cache table
         */
        rt = mf6c_find(mfct, &ip6->ip6_src, &ip6->ip6_dst);
        MRT6STAT_INC(mrt6s_mfc_lookups);

        /* Entry exists, so forward if necessary */
        if (rt) {
                MFC6_UNLOCK();
                return (ip6_mdq(mfct, m, ifp, rt));
        }

        /*
         * 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_no_route);
        MRT6_DLOG(DEBUG_FORWARD | DEBUG_MFC, "no rte s %s g %s",
            ip6_sprintf(ip6bufs, &ip6->ip6_src),
            ip6_sprintf(ip6bufd, &ip6->ip6_dst));

        /*
         * Allocate mbufs early so that we don't do extra work if we
         * are just going to fail anyway.
         */
        rte = malloc(sizeof(*rte), M_MRTABLE6, M_NOWAIT);
        if (rte == NULL) {
                MFC6_UNLOCK();
                return (ENOBUFS);
        }
        mb0 = m_copym(m, 0, M_COPYALL, M_NOWAIT);
        /*
         * Pullup packet header if needed before storing it,
         * as other references may modify it in the meantime.
         */
        if (mb0 && (!M_WRITABLE(mb0) || mb0->m_len < sizeof(struct ip6_hdr)))
                mb0 = m_pullup(mb0, sizeof(struct ip6_hdr));
        if (mb0 == NULL) {
                free(rte, M_MRTABLE6);
                MFC6_UNLOCK();
                return (ENOBUFS);
        }

        /* is there an upcall waiting for this packet? */
        hash = MF6CHASH(ip6->ip6_src, ip6->ip6_dst);
        for (rt = mfct->mfchashtbl[hash]; rt; rt = rt->mf6c_next) {
                if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_src,
                    &rt->mf6c_origin.sin6_addr) &&
                    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
                    &rt->mf6c_mcastgrp.sin6_addr) && (rt->mf6c_stall != NULL))
                        break;
        }

        if (rt == NULL) {
                struct mrt6msg *im;
#ifdef MRT6_OINIT
                struct omrt6msg *oim;
#endif
                /* no upcall, so make a new entry */
                rt = malloc(sizeof(*rt), M_MRTABLE6, M_NOWAIT);
                if (rt == NULL) {
                        free(rte, M_MRTABLE6);
                        m_freem(mb0);
                        MFC6_UNLOCK();
                        return (ENOBUFS);
                }
                /*
                 * Make a copy of the header to send to the user
                 * level process
                 */
                mm = m_copym(mb0, 0, sizeof(struct ip6_hdr), M_NOWAIT);
                if (mm == NULL) {
                        free(rte, M_MRTABLE6);
                        m_freem(mb0);
                        free(rt, M_MRTABLE6);
                        MFC6_UNLOCK();
                        return (ENOBUFS);
                }

                /*
                 * Send message to routing daemon
                 */
                sin6.sin6_addr = ip6->ip6_src;
                im = NULL;
#ifdef MRT6_OINIT
                oim = NULL;
#endif
                switch (mfct->router_ver) {
#ifdef MRT6_OINIT
                case MRT6_OINIT:
                        oim = mtod(mm, struct omrt6msg *);
                        oim->im6_msgtype = MRT6MSG_NOCACHE;
                        oim->im6_mbz = 0;
                        break;
#endif
                case MRT6_INIT:
                        im = mtod(mm, struct mrt6msg *);
                        im->im6_msgtype = MRT6MSG_NOCACHE;
                        im->im6_mbz = 0;
                        break;
                default:
                        free(rte, M_MRTABLE6);
                        m_freem(mb0);
                        free(rt, M_MRTABLE6);
                        MFC6_UNLOCK();
                        return (EINVAL);
                }

                MRT6_DLOG(DEBUG_FORWARD, "getting the iif info in the kernel");
                for (mifp = mfct->miftable, mifi = 0;
                    mifi < mfct->nummifs && mifp->m6_ifp != ifp; mifp++, mifi++)
                        ;

                switch (mfct->router_ver) {
#ifdef MRT6_OINIT
                case MRT6_OINIT:
                        oim->im6_mif = mifi;
                        break;
#endif
                case MRT6_INIT:
                        im->im6_mif = mifi;
                        break;
                }

                if (socket_send(mfct->router, mm, &sin6) < 0) {
                        log(LOG_WARNING, "ip6_mforward: ip6_mrouter "
                            "socket queue full\n");
                        MRT6STAT_INC(mrt6s_upq_sockfull);
                        free(rte, M_MRTABLE6);
                        m_freem(mb0);
                        free(rt, M_MRTABLE6);
                        MFC6_UNLOCK();
                        return (ENOBUFS);
                }

                MRT6STAT_INC(mrt6s_upcalls);

                /* insert new entry at head of hash chain */
                bzero(rt, sizeof(*rt));
                rt->mf6c_origin.sin6_family = AF_INET6;
                rt->mf6c_origin.sin6_len = sizeof(struct sockaddr_in6);
                rt->mf6c_origin.sin6_addr = ip6->ip6_src;
                rt->mf6c_mcastgrp.sin6_family = AF_INET6;
                rt->mf6c_mcastgrp.sin6_len = sizeof(struct sockaddr_in6);
                rt->mf6c_mcastgrp.sin6_addr = ip6->ip6_dst;
                rt->mf6c_expire = UPCALL_EXPIRE;
                mfct->nexpire[hash]++;
                rt->mf6c_parent = MF6C_INCOMPLETE_PARENT;

                /* link into table */
                rt->mf6c_next = mfct->mfchashtbl[hash];
                mfct->mfchashtbl[hash] = rt;
                /* Add this entry to the end of the queue */
                rt->mf6c_stall = rte;
        } else {
                /* determine if q has overflowed */
                struct rtdetq **p;
                int npkts = 0;

                for (p = &rt->mf6c_stall; *p != NULL; p = &(*p)->next)
                        if (++npkts > MAX_UPQ6) {
                                MRT6STAT_INC(mrt6s_upq_ovflw);
                                free(rte, M_MRTABLE6);
                                m_freem(mb0);
                                MFC6_UNLOCK();
                                return (0);
                        }

                /* Add this entry to the end of the queue */
                *p = rte;
        }

        rte->next = NULL;
        rte->m = mb0;
        rte->ifp = ifp;
#ifdef UPCALL_TIMING
        rte->t = tp;
#endif /* UPCALL_TIMING */

        MFC6_UNLOCK();

        return (0);
}

/*
 * Clean up cache entries if upcalls are not serviced
 * Call from the Slow Timeout mechanism, every half second.
 */
static void
expire_upcalls(struct mf6ctable *mfct)
{
#ifdef MRT6DEBUG
        char ip6bufo[INET6_ADDRSTRLEN], ip6bufg[INET6_ADDRSTRLEN];
#endif
        struct rtdetq *rte;
        struct mf6c *mfc, **nptr;
        u_long i;

        MFC6_LOCK_ASSERT();

        for (i = 0; i < MF6CTBLSIZ; i++) {
                if (mfct->nexpire[i] == 0)
                        continue;
                nptr = &mfct->mfchashtbl[i];
                while ((mfc = *nptr) != NULL) {
                        rte = mfc->mf6c_stall;
                        /*
                         * Skip real cache entries
                         * Make sure it wasn't marked to not expire (shouldn't happen)
                         * If it expires now
                         */
                        if (rte != NULL &&
                            mfc->mf6c_expire != 0 &&
                            --mfc->mf6c_expire == 0) {
                                MRT6_DLOG(DEBUG_EXPIRE, "expiring (%s %s)",
                                    ip6_sprintf(ip6bufo, &mfc->mf6c_origin.sin6_addr),
                                    ip6_sprintf(ip6bufg, &mfc->mf6c_mcastgrp.sin6_addr));
                                /*
                                 * drop all the packets
                                 * free the mbuf with the pkt, if, timing info
                                 */
                                do {
                                        struct rtdetq *n = rte->next;
                                        m_freem(rte->m);
                                        free(rte, M_MRTABLE6);
                                        rte = n;
                                } while (rte != NULL);
                                MRT6STAT_INC(mrt6s_cache_cleanups);
                                mfct->nexpire[i]--;

                                *nptr = mfc->mf6c_next;
                                free(mfc, M_MRTABLE6);
                        } else {
                                nptr = &mfc->mf6c_next;
                        }
                }
        }
}

/*
 * Clean up the cache entry if upcall is not serviced
 */
static void
expire_upcalls_all(void *arg)
{
        CURVNET_SET((struct vnet *)arg);

        for (int i = 0; i < V_nmfctables; i++)
                expire_upcalls(&V_mfctables[i]);

        callout_reset(&V_expire_upcalls_ch, EXPIRE_TIMEOUT, expire_upcalls_all,
            curvnet);

        CURVNET_RESTORE();
}

/*
 * Packet forwarding routine once entry in the cache is made
 */
static int
ip6_mdq(struct mf6ctable *mfct, struct mbuf *m, struct ifnet *ifp,
    struct mf6c *rt)
{
        struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
        mifi_t mifi, iif;
        struct mif6 *mifp;
        int plen = m->m_pkthdr.len;
        struct in6_addr src0, dst0; /* copies for local work */
        u_int32_t iszone, idzone, oszone, odzone;
        int error = 0;

        M_ASSERTMAPPED(m);

        /*
         * Don't forward if it didn't arrive from the parent mif
         * for its origin.
         */
        mifi = rt->mf6c_parent;
        if (mifi >= mfct->nummifs || mfct->miftable[mifi].m6_ifp != ifp) {
                MRT6STAT_INC(mrt6s_wrong_if);
                rt->mf6c_wrong_if++;
                if (mifi >= mfct->nummifs)
                        return (0);

                mifp = &mfct->miftable[mifi];
                MRT6_DLOG(DEBUG_FORWARD,
                    "wrong if: ifid %d mifi %d mififid %x", ifp->if_index,
                    mifi, mifp->m6_ifp->if_index);

                /*
                 * If we are doing PIM processing, and we are forwarding
                 * packets on this interface, send a message to the
                 * routing daemon.
                 */
                /* have to make sure this is a valid mif */
                if (mifp->m6_ifp && V_pim6 && (m->m_flags & M_LOOP) == 0) {
                        /*
                         * Check the M_LOOP flag to avoid an
                         * unnecessary PIM assert.
                         * XXX: M_LOOP is an ad-hoc hack...
                         */
                        static struct sockaddr_in6 sin6 =
                        { sizeof(sin6), AF_INET6 };

                        struct mbuf *mm;
                        struct mrt6msg *im;
#ifdef MRT6_OINIT
                        struct omrt6msg *oim;
#endif

                        mm = m_copym(m, 0, sizeof(struct ip6_hdr),
                            M_NOWAIT);
                        if (mm &&
                            (!M_WRITABLE(mm) ||
                             mm->m_len < sizeof(struct ip6_hdr)))
                                mm = m_pullup(mm, sizeof(struct ip6_hdr));
                        if (mm == NULL)
                                return (ENOBUFS);

#ifdef MRT6_OINIT
                        oim = NULL;
#endif
                        im = NULL;
                        switch (mfct->router_ver) {
#ifdef MRT6_OINIT
                        case MRT6_OINIT:
                                oim = mtod(mm, struct omrt6msg *);
                                oim->im6_msgtype = MRT6MSG_WRONGMIF;
                                oim->im6_mbz = 0;
                                break;
#endif
                        case MRT6_INIT:
                                im = mtod(mm, struct mrt6msg *);
                                im->im6_msgtype = MRT6MSG_WRONGMIF;
                                im->im6_mbz = 0;
                                break;
                        default:
                                m_freem(mm);
                                return (EINVAL);
                        }

                        for (mifp = mfct->miftable, iif = 0;
                             iif < mfct->nummifs && mifp->m6_ifp != ifp;
                             mifp++, iif++)
                                ;

                        switch (mfct->router_ver) {
#ifdef MRT6_OINIT
                        case MRT6_OINIT:
                                oim->im6_mif = iif;
                                sin6.sin6_addr = oim->im6_src;
                                break;
#endif
                        case MRT6_INIT:
                                im->im6_mif = iif;
                                sin6.sin6_addr = im->im6_src;
                                break;
                        }

                        MRT6STAT_INC(mrt6s_upcalls);

                        if (socket_send(mfct->router, mm, &sin6) < 0) {
                                MRT6_DLOG(DEBUG_ANY,
                                    "ip6_mrouter socket queue full");
                                MRT6STAT_INC(mrt6s_upq_sockfull);
                                return (ENOBUFS);
                        }
                }
                return (0);
        }

        mifp = &mfct->miftable[mifi];

        /* If I sourced this packet, it counts as output, else it was input. */
        if (m->m_pkthdr.rcvif == NULL) {
                /* XXX: is rcvif really NULL when output?? */
                mifp->m6_pkt_out++;
                mifp->m6_bytes_out += plen;
        } else {
                mifp->m6_pkt_in++;
                mifp->m6_bytes_in += plen;
        }
        rt->mf6c_pkt_cnt++;
        rt->mf6c_byte_cnt += plen;

        /*
         * For each mif, forward a copy of the packet if there are group
         * members downstream on the interface.
         */
        src0 = ip6->ip6_src;
        dst0 = ip6->ip6_dst;
        if ((error = in6_setscope(&src0, ifp, &iszone)) != 0 ||
            (error = in6_setscope(&dst0, ifp, &idzone)) != 0) {
                IP6STAT_INC(ip6s_badscope);
                return (error);
        }
        for (mifp = mfct->miftable, mifi = 0; mifi < mfct->nummifs;
            mifp++, mifi++) {
                if (IF_ISSET(mifi, &rt->mf6c_ifset)) {
                        /*
                         * check if the outgoing packet is going to break
                         * a scope boundary.
                         * XXX For packets through PIM register tunnel
                         * interface, we believe a routing daemon.
                         */
                        if (!(mfct->miftable[rt->mf6c_parent].m6_flags &
                              MIFF_REGISTER) &&
                            !(mifp->m6_flags & MIFF_REGISTER)) {
                                if (in6_setscope(&src0, mifp->m6_ifp,
                                    &oszone) ||
                                    in6_setscope(&dst0, mifp->m6_ifp,
                                    &odzone) ||
                                    iszone != oszone ||
                                    idzone != odzone) {
                                        IP6STAT_INC(ip6s_badscope);
                                        continue;
                                }
                        }

                        mifp->m6_pkt_out++;
                        mifp->m6_bytes_out += plen;
                        if (mifp->m6_flags & MIFF_REGISTER)
                                register_send(mfct, ip6, mifi, m);
                        else
                                phyint_send(ip6, mifp, m);
                }
        }
        return (0);
}

static void
phyint_send(struct ip6_hdr *ip6, struct mif6 *mifp, struct mbuf *m)
{
#ifdef MRT6DEBUG
        char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
#endif
        struct mbuf *mb_copy;
        struct ifnet *ifp = mifp->m6_ifp;
        int error __unused = 0;
        u_long linkmtu;

        M_ASSERTMAPPED(m);

        /*
         * 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_copym(m, 0, M_COPYALL, M_NOWAIT);
        if (mb_copy &&
            (!M_WRITABLE(mb_copy) || mb_copy->m_len < sizeof(struct ip6_hdr)))
                mb_copy = m_pullup(mb_copy, sizeof(struct ip6_hdr));
        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 devide
         * 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.rcvif == NULL) {
                struct ip6_moptions im6o;
                struct epoch_tracker et;

                im6o.im6o_multicast_ifp = ifp;
                /* XXX: ip6_output will override ip6->ip6_hlim */
                im6o.im6o_multicast_hlim = ip6->ip6_hlim;
                im6o.im6o_multicast_loop = 1;
                NET_EPOCH_ENTER(et);
                error = ip6_output(mb_copy, NULL, NULL, IPV6_FORWARDING, &im6o,
                    NULL, NULL);
                NET_EPOCH_EXIT(et);

                MRT6_DLOG(DEBUG_XMIT, "mif %u err %d",
                    (uint16_t)(mifp - mif6table), error);
                return;
        }

        /*
         * If configured to loop back multicasts by default,
         * loop back a copy now.
         */
        if (in6_mcast_loop)
                ip6_mloopback(ifp, m);

        /*
         * Put the packet into the sending queue of the outgoing interface
         * if it would fit in the MTU of the interface.
         */
        linkmtu = in6_ifmtu(ifp);
        if (mb_copy->m_pkthdr.len <= linkmtu || linkmtu < IPV6_MMTU) {
                struct sockaddr_in6 dst6;

                bzero(&dst6, sizeof(dst6));
                dst6.sin6_len = sizeof(struct sockaddr_in6);
                dst6.sin6_family = AF_INET6;
                dst6.sin6_addr = ip6->ip6_dst;

                IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6);
                /*
                 * We just call if_output instead of nd6_output here, since
                 * we need no ND for a multicast forwarded packet...right?
                 */
                m_clrprotoflags(m);     /* Avoid confusing lower layers. */
                error = (*ifp->if_output)(ifp, mb_copy,
                    (struct sockaddr *)&dst6, NULL);
                MRT6_DLOG(DEBUG_XMIT, "mif %u err %d",
                    (uint16_t)(mifp - mif6table), error);
        } else {
                /*
                 * pMTU discovery is intentionally disabled by default, since
                 * various router may notify pMTU in multicast, which can be
                 * a DDoS to a router
                 */
                if (V_ip6_mcast_pmtu)
                        icmp6_error(mb_copy, ICMP6_PACKET_TOO_BIG, 0, linkmtu);
                else {
                        MRT6_DLOG(DEBUG_XMIT, " packet too big on %s o %s "
                            "g %s size %d (discarded)", if_name(ifp),
                            ip6_sprintf(ip6bufs, &ip6->ip6_src),
                            ip6_sprintf(ip6bufd, &ip6->ip6_dst),
                            mb_copy->m_pkthdr.len);
                        m_freem(mb_copy); /* simply discard the packet */
                }
        }
}

static int
register_send(struct mf6ctable *mfct, struct ip6_hdr *ip6, mifi_t mifi,
    struct mbuf *m)
{
#ifdef MRT6DEBUG
        char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
#endif
        struct mbuf *mm;
        int i, len = m->m_pkthdr.len;
        static struct sockaddr_in6 sin6 = { sizeof(sin6), AF_INET6 };
        struct mrt6msg *im6;

        MRT6_DLOG(DEBUG_ANY, "src %s dst %s",
            ip6_sprintf(ip6bufs, &ip6->ip6_src),
            ip6_sprintf(ip6bufd, &ip6->ip6_dst));
        PIM6STAT_INC(pim6s_snd_registers);

        /* Make a copy of the packet to send to the user level process. */
        mm = m_gethdr(M_NOWAIT, MT_DATA);
        if (mm == NULL)
                return (ENOBUFS);
        mm->m_data += max_linkhdr;
        mm->m_len = sizeof(struct ip6_hdr);

        if ((mm->m_next = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
                m_freem(mm);
                return (ENOBUFS);
        }
        i = MHLEN - M_LEADINGSPACE(mm);
        if (i > len)
                i = len;
        mm = m_pullup(mm, i);
        if (mm == NULL)
                return (ENOBUFS);
/* TODO: check it! */
        mm->m_pkthdr.len = len + sizeof(struct ip6_hdr);

        /*
         * Send message to routing daemon
         */
        sin6.sin6_addr = ip6->ip6_src;

        im6 = mtod(mm, struct mrt6msg *);
        im6->im6_msgtype      = MRT6MSG_WHOLEPKT;
        im6->im6_mbz          = 0;

        im6->im6_mif = mifi;

        /* iif info is not given for reg. encap.n */
        MRT6STAT_INC(mrt6s_upcalls);

        if (socket_send(mfct->router, mm, &sin6) < 0) {
                MRT6_DLOG(DEBUG_ANY, "ip6_mrouter socket queue full");
                MRT6STAT_INC(mrt6s_upq_sockfull);
                return (ENOBUFS);
        }
        return (0);
}

/*
 * pim6_encapcheck() is called by the encap6_input() path at runtime to
 * determine if a packet is for PIM; allowing PIM to be dynamically loaded
 * into the kernel.
 */
static int
pim6_encapcheck(const struct mbuf *m __unused, int off __unused,
    int proto __unused, void *arg __unused)
{

    KASSERT(proto == IPPROTO_PIM, ("not for IPPROTO_PIM"));
    return (8);         /* claim the datagram. */
}

/*
 * PIM sparse mode hook
 * Receives the pim control messages, and passes them up to the listening
 * socket, using rip6_input.
 * The only message processed is the REGISTER pim message; the pim header
 * is stripped off, and the inner packet is passed to register_mforward.
 */
static int
pim6_input(struct mbuf *m, int off, int proto, void *arg __unused)
{
        struct mf6ctable *mfct;
        struct pim *pim;
        struct ip6_hdr *ip6;
        int pimlen;
        int minlen;

        mfct = &V_mfctables[M_GETFIB(m)];

        PIM6STAT_INC(pim6s_rcv_total);

        /*
         * Validate lengths
         */
        pimlen = m->m_pkthdr.len - off;
        if (pimlen < PIM_MINLEN) {
                PIM6STAT_INC(pim6s_rcv_tooshort);
                MRT6_DLOG(DEBUG_PIM, "PIM packet too short");
                m_freem(m);
                return (IPPROTO_DONE);
        }

        /*
         * if the packet is at least as big as a REGISTER, go ahead
         * and grab the PIM REGISTER header size, to avoid another
         * possible m_pullup() later.
         *
         * PIM_MINLEN       == pimhdr + u_int32 == 8
         * PIM6_REG_MINLEN   == pimhdr + reghdr + eip6hdr == 4 + 4 + 40
         */
        minlen = (pimlen >= PIM6_REG_MINLEN) ? PIM6_REG_MINLEN : PIM_MINLEN;

        /*
         * Make sure that the IP6 and PIM headers in contiguous memory, and
         * possibly the PIM REGISTER header
         */
        if (m->m_len < off + minlen) {
                m = m_pullup(m, off + minlen);
                if (m == NULL) {
                        IP6STAT_INC(ip6s_exthdrtoolong);
                        return (IPPROTO_DONE);
                }
        }
        ip6 = mtod(m, struct ip6_hdr *);
        pim = (struct pim *)((caddr_t)ip6 + off);

#define PIM6_CHECKSUM
#ifdef PIM6_CHECKSUM
        {
                int cksumlen;

                /*
                 * Validate checksum.
                 * If PIM REGISTER, exclude the data packet
                 */
                if (pim->pim_type == PIM_REGISTER)
                        cksumlen = PIM_MINLEN;
                else
                        cksumlen = pimlen;

                if (in6_cksum(m, IPPROTO_PIM, off, cksumlen)) {
                        PIM6STAT_INC(pim6s_rcv_badsum);
                        MRT6_DLOG(DEBUG_PIM, "invalid checksum");
                        m_freem(m);
                        return (IPPROTO_DONE);
                }
        }
#endif /* PIM_CHECKSUM */

        /* PIM version check */
        if (pim->pim_ver != PIM_VERSION) {
                PIM6STAT_INC(pim6s_rcv_badversion);
                MRT6_DLOG(DEBUG_ANY | DEBUG_ERR,
                    "incorrect version %d, expecting %d",
                    pim->pim_ver, PIM_VERSION);
                m_freem(m);
                return (IPPROTO_DONE);
        }

        if (pim->pim_type == PIM_REGISTER) {
                /*
                 * since this is a REGISTER, we'll make a copy of the register
                 * headers ip6+pim+u_int32_t+encap_ip6, to be passed up to the
                 * routing daemon.
                 */
                static struct sockaddr_in6 dst = { sizeof(dst), AF_INET6 };

                struct mbuf *mcp;
                struct ip6_hdr *eip6;
                u_int32_t *reghdr;
#ifdef MRT6DEBUG
                char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
#endif

                PIM6STAT_INC(pim6s_rcv_registers);

                if (mfct->register_mif >= mfct->nummifs ||
                    mfct->register_mif == (mifi_t)-1) {
                        MRT6_DLOG(DEBUG_PIM, "register mif not set: %d",
                            mfct->register_mif);
                        m_freem(m);
                        return (IPPROTO_DONE);
                }

                reghdr = (u_int32_t *)(pim + 1);

                if ((ntohl(*reghdr) & PIM_NULL_REGISTER))
                        goto pim6_input_to_daemon;

                /*
                 * Validate length
                 */
                if (pimlen < PIM6_REG_MINLEN) {
                        PIM6STAT_INC(pim6s_rcv_tooshort);
                        PIM6STAT_INC(pim6s_rcv_badregisters);
                        MRT6_DLOG(DEBUG_ANY | DEBUG_ERR, "register packet "
                            "size too small %d from %s",
                            pimlen, ip6_sprintf(ip6bufs, &ip6->ip6_src));
                        m_freem(m);
                        return (IPPROTO_DONE);
                }

                eip6 = (struct ip6_hdr *) (reghdr + 1);
                MRT6_DLOG(DEBUG_PIM, "eip6: %s -> %s, eip6 plen %d",
                    ip6_sprintf(ip6bufs, &eip6->ip6_src),
                    ip6_sprintf(ip6bufd, &eip6->ip6_dst),
                    ntohs(eip6->ip6_plen));

                /* verify the version number of the inner packet */
                if ((eip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
                        PIM6STAT_INC(pim6s_rcv_badregisters);
                        MRT6_DLOG(DEBUG_ANY, "invalid IP version (%d) "
                            "of the inner packet",
                            (eip6->ip6_vfc & IPV6_VERSION));
                        m_freem(m);
                        return (IPPROTO_DONE);
                }

                /* verify the inner packet is destined to a mcast group */
                if (!IN6_IS_ADDR_MULTICAST(&eip6->ip6_dst)) {
                        PIM6STAT_INC(pim6s_rcv_badregisters);
                        MRT6_DLOG(DEBUG_PIM, "inner packet of register "
                            "is not multicast %s",
                            ip6_sprintf(ip6bufd, &eip6->ip6_dst));
                        m_freem(m);
                        return (IPPROTO_DONE);
                }

                /*
                 * make a copy of the whole header to pass to the daemon later.
                 */
                mcp = m_copym(m, 0, off + PIM6_REG_MINLEN, M_NOWAIT);
                if (mcp == NULL) {
                        MRT6_DLOG(DEBUG_ANY | DEBUG_ERR, "pim register: "
                            "could not copy register head");
                        m_freem(m);
                        return (IPPROTO_DONE);
                }

                /*
                 * forward the inner ip6 packet; point m_data at the inner ip6.
                 */
                m_adj(m, off + PIM_MINLEN);
                MRT6_DLOG(DEBUG_PIM, "forwarding decapsulated register: "
                    "src %s, dst %s, mif %d",
                    ip6_sprintf(ip6bufs, &eip6->ip6_src),
                    ip6_sprintf(ip6bufd, &eip6->ip6_dst), mfct->register_mif);

                if_simloop(mfct->miftable[mfct->register_mif].m6_ifp, m,
                    dst.sin6_family, 0);

                /* prepare the register head to send to the mrouting daemon */
                m = mcp;
        }

        /*
         * Pass the PIM message up to the daemon; if it is a register message
         * pass the 'head' only up to the daemon. This includes the
         * encapsulator ip6 header, pim header, register header and the
         * encapsulated ip6 header.
         */
  pim6_input_to_daemon:
        return (rip6_input(&m, &off, proto));
}

static void
ip6_mrouter_ifdetach(void *arg __unused, struct ifnet *ifp)
{
        struct mf6ctable *mfct;

        if (!V_ip6_mrouting_enabled)
                return;
        for (int i = 0; i < V_nmfctables; i++) {
                mfct = &V_mfctables[i];

                MIF6_LOCK();
restart:
                for (mifi_t mifi = 0; mifi < mfct->nummifs; mifi++) {
                        int error __diagused;

                        if (mfct->miftable[mifi].m6_ifp != ifp)
                                continue;
                        error = del_m6if_locked(mfct, mifi);
                        KASSERT(error == 0,
                            ("del_m6if_locked(%s) %d", ifp->if_xname, error));
                        goto restart;
                }
                MIF6_UNLOCK();
        }
}

static void
ip6_mroute_rtnumfibs_change(void *arg __unused, uint32_t ntables)
{
        struct mf6ctable *mfctables, *omfctables;

        KASSERT(ntables >= V_nmfctables,
            ("%s: ntables %u nmfctables %u", __func__, ntables, V_nmfctables));

        mfctables = mallocarray(ntables, sizeof(*mfctables), M_MRTABLE6,
            M_WAITOK | M_ZERO);
        omfctables = V_mfctables;

        MROUTER6_LOCK();
        MFC6_LOCK();
        for (int i = 0; i < V_nmfctables; i++)
                memcpy(&mfctables[i], &omfctables[i], sizeof(*mfctables));
        atomic_store_rel_ptr((uintptr_t *)&V_mfctables, (uintptr_t)mfctables);
        MFC6_UNLOCK();
        MROUTER6_UNLOCK();

        NET_EPOCH_WAIT();

        V_nmfctables = ntables;
        free(omfctables, M_MRTABLE6);
}

static void
vnet_mroute_init(const void *unused __unused)
{
        ip6_mroute_rtnumfibs_change(NULL, V_rt_numfibs);

        callout_init_mtx(&V_expire_upcalls_ch, MFC6_LOCKPTR(), 0);
}
VNET_SYSINIT(vnet_mroute6_init, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mroute_init,
    NULL);

static void
vnet_mroute_uninit(const void *unused __unused)
{
        callout_drain(&V_expire_upcalls_ch);
        free(V_mfctables, M_MRTABLE6);
        V_mfctables = NULL;
}
VNET_SYSUNINIT(vnet_mroute6_uninit, SI_SUB_PROTO_MC, SI_ORDER_ANY,
    vnet_mroute_uninit, NULL);

static int
ip6_mroute_modevent(module_t mod, int type, void *unused)
{

        switch (type) {
        case MOD_LOAD:
                MROUTER6_LOCK_INIT();
                MFC6_LOCK_INIT();
                MIF6_LOCK_INIT();

                ifdetach_tag = EVENTHANDLER_REGISTER(
                    ifnet_departure_event, ip6_mrouter_ifdetach,
                    NULL, EVENTHANDLER_PRI_ANY);
                rtnumfibs_change_tag = EVENTHANDLER_REGISTER(
                    rtnumfibs_change, ip6_mroute_rtnumfibs_change,
                    NULL, EVENTHANDLER_PRI_ANY);

                pim6_encap_cookie = ip6_encap_attach(&ipv6_encap_cfg,
                    NULL, M_WAITOK);
                if (pim6_encap_cookie == NULL) {
                        printf("ip6_mroute: unable to attach pim6 encap\n");
                        MIF6_LOCK_DESTROY();
                        MFC6_LOCK_DESTROY();
                        MROUTER6_LOCK_DESTROY();
                        return (EINVAL);
                }

                ip6_mforward = X_ip6_mforward;
                ip6_mrouter_done = X_ip6_mrouter_done;
                ip6_mrouter_get = X_ip6_mrouter_get;
                ip6_mrouter_set = X_ip6_mrouter_set;
                mrt6_ioctl = X_mrt6_ioctl;
                break;

        case MOD_UNLOAD:
                if (V_ip6_mrouting_enabled)
                        return (EBUSY);

                EVENTHANDLER_DEREGISTER(ifnet_departure_event,
                    ifdetach_tag);
                EVENTHANDLER_DEREGISTER(rtnumfibs_change,
                    rtnumfibs_change_tag);

                if (pim6_encap_cookie) {
                        ip6_encap_detach(pim6_encap_cookie);
                        pim6_encap_cookie = NULL;
                }

                ip6_mforward = NULL;
                ip6_mrouter_done = NULL;
                ip6_mrouter_get = NULL;
                ip6_mrouter_set = NULL;
                mrt6_ioctl = NULL;

                MIF6_LOCK_DESTROY();
                MFC6_LOCK_DESTROY();
                MROUTER6_LOCK_DESTROY();
                break;

        default:
                return (EOPNOTSUPP);
        }

        return (0);
}

static moduledata_t ip6_mroutemod = {
        "ip6_mroute",
        ip6_mroute_modevent,
        0
};

DECLARE_MODULE(ip6_mroute, ip6_mroutemod, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE);