ip6_mroute.c

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/*-
 * 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.
 *
 *      @(#)ip_mroute.c 8.2 (Berkeley) 11/15/93
 *      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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
 
#include "opt_inet6.h"
 
#include <sys/param.h>
#include <sys/callout.h>
#include <sys/errno.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/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_types.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");
 
static int      ip6_mdq(struct mbuf *, struct ifnet *, struct mf6c *);
static void     phyint_send(struct ip6_hdr *, struct mif6 *, struct mbuf *);
static int      register_send(struct ip6_hdr *, struct mif6 *, 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
};
 
VNET_DEFINE_STATIC(int, ip6_mrouter_ver) = 0;
#define V_ip6_mrouter_ver       VNET(ip6_mrouter_ver)
 
SYSCTL_DECL(_net_inet6);
SYSCTL_DECL(_net_inet6_ip6);
static SYSCTL_NODE(_net_inet6, IPPROTO_PIM, pim,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "PIM");
 
static struct mrt6stat mrt6stat;
SYSCTL_STRUCT(_net_inet6_ip6, OID_AUTO, mrt6stat, CTLFLAG_RW,
    &mrt6stat, mrt6stat,
    "Multicast Routing Statistics (struct mrt6stat, netinet6/ip6_mroute.h)");
 
#define MRT6STAT_INC(name)      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 mf6c *mf6ctable[MF6CTBLSIZ];
SYSCTL_OPAQUE(_net_inet6_ip6, OID_AUTO, mf6ctable, CTLFLAG_RD,
    &mf6ctable, sizeof(mf6ctable), "S,*mf6ctable[MF6CTBLSIZ]",
    "IPv6 Multicast Forwarding Table (struct *mf6ctable[MF6CTBLSIZ], "
    "netinet6/ip6_mroute.h)");
 
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())
 
static u_char n6expire[MF6CTBLSIZ];
 
static struct mif6 mif6table[MAXMIFS];
static int
sysctl_mif6table(SYSCTL_HANDLER_ARGS)
{
        struct mif6_sctl *out;
        int error;
 
        out = malloc(sizeof(struct mif6_sctl) * MAXMIFS, M_TEMP,
            M_WAITOK | M_ZERO);
        for (int i = 0; i < MAXMIFS; i++) {
                out[i].m6_flags         = mif6table[i].m6_flags;
                out[i].m6_rate_limit    = mif6table[i].m6_rate_limit;
                out[i].m6_lcl_addr      = mif6table[i].m6_lcl_addr;
                if (mif6table[i].m6_ifp != NULL)
                        out[i].m6_ifp   = mif6table[i].m6_ifp->if_index;
                else
                        out[i].m6_ifp   = 0;
                out[i].m6_pkt_in        = mif6table[i].m6_pkt_in;
                out[i].m6_pkt_out       = mif6table[i].m6_pkt_out;
                out[i].m6_bytes_in      = mif6table[i].m6_bytes_in;
                out[i].m6_bytes_out     = mif6table[i].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(void *);
#define EXPIRE_TIMEOUT  (hz / 4)        /* 4x / second */
#define UPCALL_EXPIRE   6               /* number of timeouts */
 
/*
 * XXX TODO: maintain a count to if_allmulti() calls in struct ifnet.
 */
 
/*
 * '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.
 */
static struct ifnet *multicast_register_if6;
 
#define ENCAP_HOPS 64
 
/*
 * Private variables.
 */
static mifi_t nummifs = 0;
static mifi_t reg_mif_num = (mifi_t)-1;
 
static struct pim6stat pim6stat;
SYSCTL_STRUCT(_net_inet6_pim, PIM6CTL_STATS, stats, CTLFLAG_RW,
    &pim6stat, pim6stat,
    "PIM Statistics (struct pim6stat, netinet6/pim6_var.h)");
 
#define PIM6STAT_INC(name)      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])
 
/*
 * Find a route for a given origin IPv6 address and Multicast group address.
 */
#define MF6CFIND(o, g, rt) do { \
        struct mf6c *_rt = mf6ctable[MF6CHASH(o,g)]; \
        rt = NULL; \
        while (_rt) { \
                if (IN6_ARE_ADDR_EQUAL(&_rt->mf6c_origin.sin6_addr, &(o)) && \
                    IN6_ARE_ADDR_EQUAL(&_rt->mf6c_mcastgrp.sin6_addr, &(g)) && \
                    (_rt->mf6c_stall == NULL)) { \
                        rt = _rt; \
                        break; \
                } \
                _rt = _rt->mf6c_next; \
        } \
        if (rt == NULL) { \
                MRT6STAT_INC(mrt6s_mfc_misses); \
        } \
} while (/*CONSTCOND*/ 0)
 
/*
 * 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();
#endif /* UPCALL_TIMING */
 
static int ip6_mrouter_init(struct socket *, int, int);
static int add_m6fc(struct mf6cctl *);
static int add_m6if(struct mif6ctl *);
static int del_m6fc(struct mf6cctl *);
static int del_m6if(mifi_t *);
static int del_m6if_locked(mifi_t *);
static int get_mif6_cnt(struct sioc_mif_req6 *);
static int get_sg_cnt(struct sioc_sg_req6 *);
 
static struct callout expire_upcalls_ch;
 
int X_ip6_mforward(struct ip6_hdr *, struct ifnet *, struct mbuf *);
int X_ip6_mrouter_done(void);
int X_ip6_mrouter_set(struct socket *, struct sockopt *);
int X_ip6_mrouter_get(struct socket *, struct sockopt *);
int X_mrt6_ioctl(u_long, caddr_t);
 
/*
 * Handle MRT setsockopt commands to modify the multicast routing tables.
 */
int
X_ip6_mrouter_set(struct socket *so, struct sockopt *sopt)
{
        int error = 0;
        int optval;
        struct mif6ctl mifc;
        struct mf6cctl mfcc;
        mifi_t mifi;
 
        if (so != V_ip6_mrouter && 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:
                error = X_ip6_mrouter_done();
                break;
        case MRT6_ADD_MIF:
                error = sooptcopyin(sopt, &mifc, sizeof(mifc), sizeof(mifc));
                if (error)
                        break;
                error = add_m6if(&mifc);
                break;
        case MRT6_ADD_MFC:
                error = sooptcopyin(sopt, &mfcc, sizeof(mfcc), sizeof(mfcc));
                if (error)
                        break;
                error = add_m6fc(&mfcc);
                break;
        case MRT6_DEL_MFC:
                error = sooptcopyin(sopt, &mfcc, sizeof(mfcc), sizeof(mfcc));
                if (error)
                        break;
                error = del_m6fc(&mfcc);
                break;
        case MRT6_DEL_MIF:
                error = sooptcopyin(sopt, &mifi, sizeof(mifi), sizeof(mifi));
                if (error)
                        break;
                error = del_m6if(&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
 */
int
X_ip6_mrouter_get(struct socket *so, struct sockopt *sopt)
{
        int error = 0;
 
        if (so != V_ip6_mrouter)
                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
 */
int
X_mrt6_ioctl(u_long cmd, caddr_t data)
{
        int ret;
 
        ret = EINVAL;
 
        switch (cmd) {
        case SIOCGETSGCNT_IN6:
                ret = get_sg_cnt((struct sioc_sg_req6 *)data);
                break;
 
        case SIOCGETMIFCNT_IN6:
                ret = get_mif6_cnt((struct sioc_mif_req6 *)data);
                break;
 
        default:
                break;
        }
 
        return (ret);
}
 
/*
 * returns the packet, byte, rpf-failure count for the source group provided
 */
static int
get_sg_cnt(struct sioc_sg_req6 *req)
{
        struct mf6c *rt;
        int ret;
 
        ret = 0;
 
        MFC6_LOCK();
 
        MF6CFIND(req->src.sin6_addr, req->grp.sin6_addr, rt);
        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 sioc_mif_req6 *req)
{
        mifi_t mifi;
        int ret;
 
        ret = 0;
        mifi = req->mifi;
 
        MIF6_LOCK();
 
        if (mifi >= nummifs) {
                ret = EINVAL;
        } else {
                req->icount = mif6table[mifi].m6_pkt_in;
                req->ocount = mif6table[mifi].m6_pkt_out;
                req->ibytes = mif6table[mifi].m6_bytes_in;
                req->obytes = mif6table[mifi].m6_bytes_out;
        }
 
        MIF6_UNLOCK();
 
        return (ret);
}
 
static int
set_pim6(int *i)
{
        if ((*i != 1) && (*i != 0))
                return (EINVAL);
 
        V_pim6 = *i;
 
        return (0);
}
 
/*
 * Enable multicast routing
 */
static int
ip6_mrouter_init(struct socket *so, int v, int cmd)
{
 
        MRT6_DLOG(DEBUG_ANY, "so_type = %d, pr_protocol = %d",
            so->so_type, so->so_proto->pr_protocol);
 
        if (so->so_type != SOCK_RAW ||
            so->so_proto->pr_protocol != IPPROTO_ICMPV6)
                return (EOPNOTSUPP);
 
        if (v != 1)
                return (ENOPROTOOPT);
 
        MROUTER6_LOCK();
 
        if (V_ip6_mrouter != NULL) {
                MROUTER6_UNLOCK();
                return (EADDRINUSE);
        }
 
        V_ip6_mrouter = so;
        V_ip6_mrouter_ver = cmd;
 
        bzero((caddr_t)mf6ctable, sizeof(mf6ctable));
        bzero((caddr_t)n6expire, sizeof(n6expire));
 
        V_pim6 = 0;/* used for stubbing out/in pim stuff */
 
        callout_init_mtx(&expire_upcalls_ch, MFC6_LOCKPTR(), 0);
        callout_reset(&expire_upcalls_ch, EXPIRE_TIMEOUT,
            expire_upcalls, NULL);
 
        MROUTER6_UNLOCK();
 
        MRT6_DLOG(DEBUG_ANY, "finished");
 
        return (0);
}
 
/*
 * Disable IPv6 multicast forwarding.
 */
int
X_ip6_mrouter_done(void)
{
        mifi_t mifi;
        u_long i;
        struct mf6c *rt;
        struct rtdetq *rte;
 
        MROUTER6_LOCK();
 
        if (V_ip6_mrouter == NULL) {
                MROUTER6_UNLOCK();
                return (EINVAL);
        }
 
        /*
         * For each phyint in use, disable promiscuous reception of all IPv6
         * multicasts.
         */
        for (mifi = 0; mifi < nummifs; mifi++) {
                if (mif6table[mifi].m6_ifp &&
                    !(mif6table[mifi].m6_flags & MIFF_REGISTER)) {
                        if_allmulti(mif6table[mifi].m6_ifp, 0);
                }
        }
        bzero((caddr_t)mif6table, sizeof(mif6table));
        nummifs = 0;
 
        V_pim6 = 0; /* used to stub out/in pim specific code */
 
        /*
         * Free all multicast forwarding cache entries.
         */
        MFC6_LOCK();
        for (i = 0; i < MF6CTBLSIZ; i++) {
                rt = mf6ctable[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);
                }
        }
        bzero((caddr_t)mf6ctable, sizeof(mf6ctable));
        MFC6_UNLOCK();
 
        callout_drain(&expire_upcalls_ch);
 
        /*
         * Reset register interface
         */
        if (reg_mif_num != (mifi_t)-1 && multicast_register_if6 != NULL) {
                if_detach(multicast_register_if6);
                if_free(multicast_register_if6);
                reg_mif_num = (mifi_t)-1;
                multicast_register_if6 = NULL;
        }
 
        V_ip6_mrouter = NULL;
        V_ip6_mrouter_ver = 0;
 
        MROUTER6_UNLOCK();
        MRT6_DLOG(DEBUG_ANY, "finished");
 
        return (0);
}
 
static struct sockaddr_in6 sin6 = { sizeof(sin6), AF_INET6 };
 
/*
 * Add a mif to the mif table
 */
static int
add_m6if(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 = mif6table + 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 (reg_mif_num == (mifi_t)-1) {
                        ifp = if_alloc(IFT_OTHER);
 
                        if_initname(ifp, "register_mif", 0);
                        ifp->if_flags |= IFF_LOOPBACK;
                        if_attach(ifp);
                        multicast_register_if6 = ifp;
                        reg_mif_num = 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 = multicast_register_if6;
                }
        } else {
                /* Make sure the interface supports multicast */
                if ((ifp->if_flags & IFF_MULTICAST) == 0) {
                        MIF6_UNLOCK();
                        return (EOPNOTSUPP);
                }
 
                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 (nummifs <= mifcp->mif6c_mifi)
                nummifs = mifcp->mif6c_mifi + 1;
 
        MIF6_UNLOCK();
        MRT6_DLOG(DEBUG_ANY, "mif #%d, phyint %s", mifcp->mif6c_mifi,
            if_name(ifp));
 
        return (0);
}
 
/*
 * Delete a mif from the mif table
 */
static int
del_m6if_locked(mifi_t *mifip)
{
        struct mif6 *mifp = mif6table + *mifip;
        mifi_t mifi;
        struct ifnet *ifp;
 
        MIF6_LOCK_ASSERT();
 
        if (*mifip >= nummifs)
                return (EINVAL);
        if (mifp->m6_ifp == NULL)
                return (EINVAL);
 
        if (!(mifp->m6_flags & MIFF_REGISTER)) {
                /* XXX: TODO: Maintain an ALLMULTI refcount in struct ifnet. */
                ifp = mifp->m6_ifp;
                if_allmulti(ifp, 0);
        } else {
                if (reg_mif_num != (mifi_t)-1 &&
                    multicast_register_if6 != NULL) {
                        if_detach(multicast_register_if6);
                        if_free(multicast_register_if6);
                        reg_mif_num = (mifi_t)-1;
                        multicast_register_if6 = NULL;
                }
        }
 
        bzero((caddr_t)mifp, sizeof(*mifp));
 
        /* Adjust nummifs down */
        for (mifi = nummifs; mifi > 0; mifi--)
                if (mif6table[mifi - 1].m6_ifp)
                        break;
        nummifs = mifi;
        MRT6_DLOG(DEBUG_ANY, "mif %d, nummifs %d", *mifip, nummifs);
 
        return (0);
}
 
static int
del_m6if(mifi_t *mifip)
{
        int cc;
 
        MIF6_LOCK();
        cc = del_m6if_locked(mifip);
        MIF6_UNLOCK();
 
        return (cc);
}
 
/*
 * Add an mfc entry
 */
static int
add_m6fc(struct mf6cctl *mfccp)
{
        struct mf6c *rt;
        u_long hash;
        struct rtdetq *rte;
        u_short nstl;
        char ip6bufo[INET6_ADDRSTRLEN], ip6bufg[INET6_ADDRSTRLEN];
 
        MFC6_LOCK();
 
        MF6CFIND(mfccp->mf6cc_origin.sin6_addr,
                 mfccp->mf6cc_mcastgrp.sin6_addr, rt);
 
        /* 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 = mf6ctable[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 */
                        n6expire[hash]--;
 
                        /* free packets Qed at the end of this entry */
                        for (rte = rt->mf6c_stall; rte != NULL; ) {
                                struct rtdetq *n = rte->next;
                                ip6_mdq(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 = mf6ctable[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)
                                        n6expire[hash]--;
                                rt->mf6c_expire    = 0;
                        }
                }
                if (rt == NULL) {
                        /* no upcall, so make a new entry */
                        rt = (struct mf6c *)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  = mf6ctable[hash];
                        mf6ctable[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 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 = &mf6ctable[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.
 */
int
X_ip6_mforward(struct ip6_hdr *ip6, struct ifnet *ifp, struct mbuf *m)
{
        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 */
 
        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_time + V_ip6_log_interval < time_uptime) {
                        V_ip6_log_time = time_uptime;
                        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);
        }
 
        MFC6_LOCK();
 
        /*
         * Determine forwarding mifs from the forwarding cache table
         */
        MF6CFIND(ip6->ip6_src, ip6->ip6_dst, rt);
        MRT6STAT_INC(mrt6s_mfc_lookups);
 
        /* Entry exists, so forward if necessary */
        if (rt) {
                MFC6_UNLOCK();
                return (ip6_mdq(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 = (struct rtdetq *)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 = mf6ctable[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 = (struct mf6c *)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 (V_ip6_mrouter_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 = mif6table, mifi = 0;
                    mifi < nummifs && mifp->m6_ifp != ifp; mifp++, mifi++)
                                ;
 
                switch (V_ip6_mrouter_ver) {
#ifdef MRT6_OINIT
                case MRT6_OINIT:
                        oim->im6_mif = mifi;
                        break;
#endif
                case MRT6_INIT:
                        im->im6_mif = mifi;
                        break;
                }
 
                if (socket_send(V_ip6_mrouter, 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;
                n6expire[hash]++;
                rt->mf6c_parent = MF6C_INCOMPLETE_PARENT;
 
                /* link into table */
                rt->mf6c_next  = mf6ctable[hash];
                mf6ctable[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(void *unused)
{
#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 (n6expire[i] == 0)
                        continue;
                nptr = &mf6ctable[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);
                                n6expire[i]--;
 
                                *nptr = mfc->mf6c_next;
                                free(mfc, M_MRTABLE6);
                        } else {
                                nptr = &mfc->mf6c_next;
                        }
                }
        }
        callout_reset(&expire_upcalls_ch, EXPIRE_TIMEOUT,
            expire_upcalls, NULL);
}
 
/*
 * Packet forwarding routine once entry in the cache is made
 */
static int
ip6_mdq(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;
 
        /*
         * Don't forward if it didn't arrive from the parent mif
         * for its origin.
         */
        mifi = rt->mf6c_parent;
        if ((mifi >= nummifs) || (mif6table[mifi].m6_ifp != ifp)) {
                /* came in the wrong interface */
                MRT6_DLOG(DEBUG_FORWARD,
                    "wrong if: ifid %d mifi %d mififid %x", ifp->if_index,
                    mifi, mif6table[mifi].m6_ifp->if_index);
                MRT6STAT_INC(mrt6s_wrong_if);
                rt->mf6c_wrong_if++;
                /*
                 * 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 (mifi < nummifs && mif6table[mifi].m6_ifp)
                        if (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 (V_ip6_mrouter_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 = mif6table, iif = 0;
                                     iif < nummifs && mifp &&
                                             mifp->m6_ifp != ifp;
                                     mifp++, iif++)
                                        ;
 
                                switch (V_ip6_mrouter_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(V_ip6_mrouter, mm, &sin6) < 0) {
                                        MRT6_DLOG(DEBUG_ANY,
                                            "ip6_mrouter socket queue full");
                                        MRT6STAT_INC(mrt6s_upq_sockfull);
                                        return (ENOBUFS);
                                }       /* if socket Q full */
                        }               /* if PIM */
                return (0);
        }                       /* if wrong iif */
 
        /* 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?? */
                mif6table[mifi].m6_pkt_out++;
                mif6table[mifi].m6_bytes_out += plen;
        } else {
                mif6table[mifi].m6_pkt_in++;
                mif6table[mifi].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 = mif6table, mifi = 0; mifi < 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 (!(mif6table[rt->mf6c_parent].m6_flags &
                              MIFF_REGISTER) &&
                            !(mif6table[mifi].m6_flags & MIFF_REGISTER)) {
                                if (in6_setscope(&src0, mif6table[mifi].m6_ifp,
                                    &oszone) ||
                                    in6_setscope(&dst0, mif6table[mifi].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(ip6, mifp, 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 = 0;
        u_long linkmtu;
 
        /*
         * 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_LINKMTU(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 ip6_hdr *ip6, struct mif6 *mif, 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 = mif - mif6table;
 
        /* iif info is not given for reg. encap.n */
        MRT6STAT_INC(mrt6s_upcalls);
 
        if (socket_send(V_ip6_mrouter, 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 pim *pim; /* pointer to a pim struct */
        struct ip6_hdr *ip6;
        int pimlen;
        int minlen;
 
        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;
                int rc;
#ifdef MRT6DEBUG
                char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
#endif
 
                PIM6STAT_INC(pim6s_rcv_registers);
 
                if ((reg_mif_num >= nummifs) || (reg_mif_num == (mifi_t) -1)) {
                        MRT6_DLOG(DEBUG_PIM, "register mif not set: %d",
                            reg_mif_num);
                        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), reg_mif_num);
 
                rc = if_simloop(mif6table[reg_mif_num].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 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();
 
                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_mrouter != NULL)
                        return EINVAL;
 
                if (pim6_encap_cookie) {
                        ip6_encap_detach(pim6_encap_cookie);
                        pim6_encap_cookie = NULL;
                }
                X_ip6_mrouter_done();
                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_ANY);