FreeBSD/Linux Kernel Cross Reference
sys/netinet/ip_mroute.c

     /*-
      * 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.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)ip_mroute.c 8.2 (Berkeley) 11/15/93
     */
    
    /*
     * IP multicast forwarding procedures
     *
     * Written by David Waitzman, BBN Labs, August 1988.
     * Modified by Steve Deering, Stanford, February 1989.
     * Modified by Mark J. Steiglitz, Stanford, May, 1991
     * Modified by Van Jacobson, LBL, January 1993
     * Modified by Ajit Thyagarajan, PARC, August 1993
     * Modified by Bill Fenner, PARC, April 1995
     * Modified by Ahmed Helmy, SGI, June 1996
     * Modified by George Edmond Eddy (Rusty), ISI, February 1998
     * Modified by Pavlin Radoslavov, USC/ISI, May 1998, August 1999, October 2000
     * Modified by Hitoshi Asaeda, WIDE, August 2000
     * Modified by Pavlin Radoslavov, ICSI, October 2002
     *
     * MROUTING Revision: 3.5
     * and PIM-SMv2 and PIM-DM support, advanced API support,
     * bandwidth metering and signaling
     */
    
    /*
     * TODO: Prefix functions with ipmf_.
     * TODO: Maintain a refcount on if_allmulti() in ifnet or in the protocol
     * domain attachment (if_afdata) so we can track consumers of that service.
     * TODO: Deprecate routing socket path for SIOCGETSGCNT and SIOCGETVIFCNT,
     * move it to socket options.
     * TODO: Cleanup LSRR removal further.
     * TODO: Push RSVP stubs into raw_ip.c.
     * TODO: Use bitstring.h for vif set.
     * TODO: Fix mrt6_ioctl dangling ref when dynamically loaded.
     * TODO: Sync ip6_mroute.c with this file.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/8.0/sys/netinet/ip_mroute.c 201679 2010-01-06 21:45:30Z simon $");
    
    #include "opt_inet.h"
    #include "opt_mrouting.h"
    
    #define _PIM_VT 1
    
    #include <sys/param.h>
    #include <sys/kernel.h>
    #include <sys/stddef.h>
    #include <sys/lock.h>
    #include <sys/ktr.h>
    #include <sys/malloc.h>
    #include <sys/mbuf.h>
    #include <sys/module.h>
    #include <sys/priv.h>
    #include <sys/protosw.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/netisr.h>
    #include <net/route.h>
   #include <net/vnet.h>
   
   #include <netinet/in.h>
   #include <netinet/igmp.h>
   #include <netinet/in_systm.h>
   #include <netinet/in_var.h>
   #include <netinet/ip.h>
   #include <netinet/ip_encap.h>
   #include <netinet/ip_mroute.h>
   #include <netinet/ip_var.h>
   #include <netinet/ip_options.h>
   #include <netinet/pim.h>
   #include <netinet/pim_var.h>
   #include <netinet/udp.h>
   
   #include <machine/in_cksum.h>
   
   #include <security/mac/mac_framework.h>
   
   #ifndef KTR_IPMF
   #define KTR_IPMF KTR_INET
   #endif
   
   #define         VIFI_INVALID    ((vifi_t) -1)
   #define         M_HASCL(m)      ((m)->m_flags & M_EXT)
   
   static MALLOC_DEFINE(M_MRTABLE, "mroutetbl", "multicast forwarding cache");
   
   /*
    * Locking.  We use two locks: one for the virtual interface table and
    * one for the forwarding table.  These locks may be nested in which case
    * the VIF lock must always be taken first.  Note that each lock is used
    * to cover not only the specific data structure but also related data
    * structures.
    */
   
   static struct mtx mrouter_mtx;
   #define MROUTER_LOCK()          mtx_lock(&mrouter_mtx)
   #define MROUTER_UNLOCK()        mtx_unlock(&mrouter_mtx)
   #define MROUTER_LOCK_ASSERT()   mtx_assert(&mrouter_mtx, MA_OWNED)
   #define MROUTER_LOCK_INIT()                                             \
           mtx_init(&mrouter_mtx, "IPv4 multicast forwarding", NULL, MTX_DEF)
   #define MROUTER_LOCK_DESTROY()  mtx_destroy(&mrouter_mtx)
   
   static struct mrtstat   mrtstat;
   SYSCTL_STRUCT(_net_inet_ip, OID_AUTO, mrtstat, CTLFLAG_RW,
       &mrtstat, mrtstat,
       "IPv4 Multicast Forwarding Statistics (struct mrtstat, "
       "netinet/ip_mroute.h)");
   
   static u_long                    mfchash;
   #define MFCHASH(a, g)                                                   \
           ((((a).s_addr >> 20) ^ ((a).s_addr >> 10) ^ (a).s_addr ^ \
             ((g).s_addr >> 20) ^ ((g).s_addr >> 10) ^ (g).s_addr) & mfchash)
   #define MFCHASHSIZE     256
   
   static u_char                   *nexpire;       /* 0..mfchashsize-1 */
   static u_long                    mfchashsize;   /* Hash size */
   LIST_HEAD(mfchashhdr, mfc)      *mfchashtbl;
   
   static struct mtx mfc_mtx;
   #define MFC_LOCK()              mtx_lock(&mfc_mtx)
   #define MFC_UNLOCK()            mtx_unlock(&mfc_mtx)
   #define MFC_LOCK_ASSERT()       mtx_assert(&mfc_mtx, MA_OWNED)
   #define MFC_LOCK_INIT()                                                 \
           mtx_init(&mfc_mtx, "IPv4 multicast forwarding cache", NULL, MTX_DEF)
   #define MFC_LOCK_DESTROY()      mtx_destroy(&mfc_mtx)
   
   static vifi_t           numvifs;
   static struct vif       viftable[MAXVIFS];
   SYSCTL_OPAQUE(_net_inet_ip, OID_AUTO, viftable, CTLFLAG_RD,
       &viftable, sizeof(viftable), "S,vif[MAXVIFS]",
       "IPv4 Multicast Interfaces (struct vif[MAXVIFS], netinet/ip_mroute.h)");
   
   static struct mtx vif_mtx;
   #define VIF_LOCK()              mtx_lock(&vif_mtx)
   #define VIF_UNLOCK()            mtx_unlock(&vif_mtx)
   #define VIF_LOCK_ASSERT()       mtx_assert(&vif_mtx, MA_OWNED)
   #define VIF_LOCK_INIT()                                                 \
           mtx_init(&vif_mtx, "IPv4 multicast interfaces", NULL, MTX_DEF)
   #define VIF_LOCK_DESTROY()      mtx_destroy(&vif_mtx)
   
   static eventhandler_tag if_detach_event_tag = NULL;
   
   static struct callout expire_upcalls_ch;
   #define         EXPIRE_TIMEOUT  (hz / 4)        /* 4x / second          */
   #define         UPCALL_EXPIRE   6               /* number of timeouts   */
   
   /*
    * Bandwidth meter variables and constants
    */
   static MALLOC_DEFINE(M_BWMETER, "bwmeter", "multicast upcall bw meters");
   /*
    * Pending timeouts are stored in a hash table, the key being the
    * expiration time. Periodically, the entries are analysed and processed.
    */
   #define BW_METER_BUCKETS        1024
   static struct bw_meter *bw_meter_timers[BW_METER_BUCKETS];
   static struct callout bw_meter_ch;
   #define BW_METER_PERIOD (hz)            /* periodical handling of bw meters */
   
   /*
    * Pending upcalls are stored in a vector which is flushed when
    * full, or periodically
    */
   static struct bw_upcall bw_upcalls[BW_UPCALLS_MAX];
   static u_int    bw_upcalls_n; /* # of pending upcalls */
   static struct callout bw_upcalls_ch;
   #define BW_UPCALLS_PERIOD (hz)          /* periodical flush of bw upcalls */
   
   static struct pimstat pimstat;
   
   SYSCTL_NODE(_net_inet, IPPROTO_PIM, pim, CTLFLAG_RW, 0, "PIM");
   SYSCTL_STRUCT(_net_inet_pim, PIMCTL_STATS, stats, CTLFLAG_RD,
       &pimstat, pimstat,
       "PIM Statistics (struct pimstat, netinet/pim_var.h)");
   
   static u_long   pim_squelch_wholepkt = 0;
   SYSCTL_ULONG(_net_inet_pim, OID_AUTO, squelch_wholepkt, CTLFLAG_RW,
       &pim_squelch_wholepkt, 0,
       "Disable IGMP_WHOLEPKT notifications if rendezvous point is unspecified");
   
   extern  struct domain inetdomain;
   static const struct protosw in_pim_protosw = {
           .pr_type =              SOCK_RAW,
           .pr_domain =            &inetdomain,
           .pr_protocol =          IPPROTO_PIM,
           .pr_flags =             PR_ATOMIC|PR_ADDR|PR_LASTHDR,
           .pr_input =             pim_input,
           .pr_output =            (pr_output_t*)rip_output,
           .pr_ctloutput =         rip_ctloutput,
           .pr_usrreqs =           &rip_usrreqs
   };
   static const struct encaptab *pim_encap_cookie;
   
   static int pim_encapcheck(const struct mbuf *, int, int, void *);
   
   /*
    * Note: the PIM Register encapsulation adds the following in front of a
    * data packet:
    *
    * struct pim_encap_hdr {
    *    struct ip ip;
    *    struct pim_encap_pimhdr  pim;
    * }
    *
    */
   
   struct pim_encap_pimhdr {
           struct pim pim;
           uint32_t   flags;
   };
   #define         PIM_ENCAP_TTL   64
   
   static struct ip pim_encap_iphdr = {
   #if BYTE_ORDER == LITTLE_ENDIAN
           sizeof(struct ip) >> 2,
           IPVERSION,
   #else
           IPVERSION,
           sizeof(struct ip) >> 2,
   #endif
           0,                      /* tos */
           sizeof(struct ip),      /* total length */
           0,                      /* id */
           0,                      /* frag offset */
           PIM_ENCAP_TTL,
           IPPROTO_PIM,
           0,                      /* checksum */
   };
   
   static struct pim_encap_pimhdr pim_encap_pimhdr = {
       {
           PIM_MAKE_VT(PIM_VERSION, PIM_REGISTER), /* PIM vers and message type */
           0,                      /* reserved */
           0,                      /* checksum */
       },
       0                           /* flags */
   };
   
   static struct ifnet multicast_register_if;
   static vifi_t reg_vif_num = VIFI_INVALID;
   
   /*
    * Private variables.
    */
   
   static u_long   X_ip_mcast_src(int);
   static int      X_ip_mforward(struct ip *, struct ifnet *, struct mbuf *,
                       struct ip_moptions *);
   static int      X_ip_mrouter_done(void);
   static int      X_ip_mrouter_get(struct socket *, struct sockopt *);
   static int      X_ip_mrouter_set(struct socket *, struct sockopt *);
   static int      X_legal_vif_num(int);
   static int      X_mrt_ioctl(u_long, caddr_t, int);
   
   static int      add_bw_upcall(struct bw_upcall *);
   static int      add_mfc(struct mfcctl2 *);
   static int      add_vif(struct vifctl *);
   static void     bw_meter_prepare_upcall(struct bw_meter *, struct timeval *);
   static void     bw_meter_process(void);
   static void     bw_meter_receive_packet(struct bw_meter *, int,
                       struct timeval *);
   static void     bw_upcalls_send(void);
   static int      del_bw_upcall(struct bw_upcall *);
   static int      del_mfc(struct mfcctl2 *);
   static int      del_vif(vifi_t);
   static int      del_vif_locked(vifi_t);
   static void     expire_bw_meter_process(void *);
   static void     expire_bw_upcalls_send(void *);
   static void     expire_mfc(struct mfc *);
   static void     expire_upcalls(void *);
   static void     free_bw_list(struct bw_meter *);
   static int      get_sg_cnt(struct sioc_sg_req *);
   static int      get_vif_cnt(struct sioc_vif_req *);
   static void     if_detached_event(void *, struct ifnet *);
   static int      ip_mdq(struct mbuf *, struct ifnet *, struct mfc *, vifi_t);
   static int      ip_mrouter_init(struct socket *, int);
   static __inline struct mfc *
                   mfc_find(struct in_addr *, struct in_addr *);
   static void     phyint_send(struct ip *, struct vif *, struct mbuf *);
   static struct mbuf *
                   pim_register_prepare(struct ip *, struct mbuf *);
   static int      pim_register_send(struct ip *, struct vif *,
                       struct mbuf *, struct mfc *);
   static int      pim_register_send_rp(struct ip *, struct vif *,
                       struct mbuf *, struct mfc *);
   static int      pim_register_send_upcall(struct ip *, struct vif *,
                       struct mbuf *, struct mfc *);
   static void     schedule_bw_meter(struct bw_meter *, struct timeval *);
   static void     send_packet(struct vif *, struct mbuf *);
   static int      set_api_config(uint32_t *);
   static int      set_assert(int);
   static int      socket_send(struct socket *, struct mbuf *,
                       struct sockaddr_in *);
   static void     unschedule_bw_meter(struct bw_meter *);
   
   /*
    * Kernel multicast forwarding API capabilities and setup.
    * If more API capabilities are added to the kernel, they should be
    * recorded in `mrt_api_support'.
    */
   #define MRT_API_VERSION         0x0305
   
   static const int mrt_api_version = MRT_API_VERSION;
   static const uint32_t mrt_api_support = (MRT_MFC_FLAGS_DISABLE_WRONGVIF |
                                            MRT_MFC_FLAGS_BORDER_VIF |
                                            MRT_MFC_RP |
                                            MRT_MFC_BW_UPCALL);
   static uint32_t mrt_api_config = 0;
   
   static int pim_assert_enabled;
   static struct timeval pim_assert_interval = { 3, 0 };   /* Rate limit */
   
   /*
    * Find a route for a given origin IP address and multicast group address.
    * Statistics must be updated by the caller.
    */
   static __inline struct mfc *
   mfc_find(struct in_addr *o, struct in_addr *g)
   {
           struct mfc *rt;
   
           MFC_LOCK_ASSERT();
   
           LIST_FOREACH(rt, &mfchashtbl[MFCHASH(*o, *g)], mfc_hash) {
                   if (in_hosteq(rt->mfc_origin, *o) &&
                       in_hosteq(rt->mfc_mcastgrp, *g) &&
                       TAILQ_EMPTY(&rt->mfc_stall))
                           break;
           }
   
           return (rt);
   }
   
   /*
    * Handle MRT setsockopt commands to modify the multicast forwarding tables.
    */
   static int
   X_ip_mrouter_set(struct socket *so, struct sockopt *sopt)
   {
       int error, optval;
       vifi_t      vifi;
       struct      vifctl vifc;
       struct      mfcctl2 mfc;
       struct      bw_upcall bw_upcall;
       uint32_t    i;
   
       if (so != V_ip_mrouter && sopt->sopt_name != MRT_INIT)
           return EPERM;
   
       error = 0;
       switch (sopt->sopt_name) {
       case MRT_INIT:
           error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval);
           if (error)
               break;
           error = ip_mrouter_init(so, optval);
           break;
   
       case MRT_DONE:
           error = ip_mrouter_done();
           break;
   
       case MRT_ADD_VIF:
           error = sooptcopyin(sopt, &vifc, sizeof vifc, sizeof vifc);
           if (error)
               break;
           error = add_vif(&vifc);
           break;
   
       case MRT_DEL_VIF:
           error = sooptcopyin(sopt, &vifi, sizeof vifi, sizeof vifi);
           if (error)
               break;
           error = del_vif(vifi);
           break;
   
       case MRT_ADD_MFC:
       case MRT_DEL_MFC:
           /*
            * select data size depending on API version.
            */
           if (sopt->sopt_name == MRT_ADD_MFC &&
                   mrt_api_config & MRT_API_FLAGS_ALL) {
               error = sooptcopyin(sopt, &mfc, sizeof(struct mfcctl2),
                                   sizeof(struct mfcctl2));
           } else {
               error = sooptcopyin(sopt, &mfc, sizeof(struct mfcctl),
                                   sizeof(struct mfcctl));
               bzero((caddr_t)&mfc + sizeof(struct mfcctl),
                           sizeof(mfc) - sizeof(struct mfcctl));
           }
           if (error)
               break;
           if (sopt->sopt_name == MRT_ADD_MFC)
               error = add_mfc(&mfc);
           else
               error = del_mfc(&mfc);
           break;
   
       case MRT_ASSERT:
           error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval);
           if (error)
               break;
           set_assert(optval);
           break;
   
       case MRT_API_CONFIG:
           error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
           if (!error)
               error = set_api_config(&i);
           if (!error)
               error = sooptcopyout(sopt, &i, sizeof i);
           break;
   
       case MRT_ADD_BW_UPCALL:
       case MRT_DEL_BW_UPCALL:
           error = sooptcopyin(sopt, &bw_upcall, sizeof bw_upcall,
                                   sizeof bw_upcall);
           if (error)
               break;
           if (sopt->sopt_name == MRT_ADD_BW_UPCALL)
               error = add_bw_upcall(&bw_upcall);
           else
               error = del_bw_upcall(&bw_upcall);
           break;
   
       default:
           error = EOPNOTSUPP;
           break;
       }
       return error;
   }
   
   /*
    * Handle MRT getsockopt commands
    */
   static int
   X_ip_mrouter_get(struct socket *so, struct sockopt *sopt)
   {
       int error;
   
       switch (sopt->sopt_name) {
       case MRT_VERSION:
           error = sooptcopyout(sopt, &mrt_api_version, sizeof mrt_api_version);
           break;
   
       case MRT_ASSERT:
           error = sooptcopyout(sopt, &pim_assert_enabled,
               sizeof pim_assert_enabled);
           break;
   
       case MRT_API_SUPPORT:
           error = sooptcopyout(sopt, &mrt_api_support, sizeof mrt_api_support);
           break;
   
       case MRT_API_CONFIG:
           error = sooptcopyout(sopt, &mrt_api_config, sizeof mrt_api_config);
           break;
   
       default:
           error = EOPNOTSUPP;
           break;
       }
       return error;
   }
   
   /*
    * Handle ioctl commands to obtain information from the cache
    */
   static int
   X_mrt_ioctl(u_long cmd, caddr_t data, int fibnum __unused)
   {
       int error = 0;
   
       /*
        * Currently the only function calling this ioctl routine is rtioctl().
        * Typically, only root can create the raw socket in order to execute
        * this ioctl method, however the request might be coming from a prison
        */
       error = priv_check(curthread, PRIV_NETINET_MROUTE);
       if (error)
           return (error);
       switch (cmd) {
       case (SIOCGETVIFCNT):
           error = get_vif_cnt((struct sioc_vif_req *)data);
           break;
   
       case (SIOCGETSGCNT):
           error = get_sg_cnt((struct sioc_sg_req *)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 sioc_sg_req *req)
   {
       struct mfc *rt;
   
       MFC_LOCK();
       rt = mfc_find(&req->src, &req->grp);
       if (rt == NULL) {
           MFC_UNLOCK();
           req->pktcnt = req->bytecnt = req->wrong_if = 0xffffffff;
           return EADDRNOTAVAIL;
       }
       req->pktcnt = rt->mfc_pkt_cnt;
       req->bytecnt = rt->mfc_byte_cnt;
       req->wrong_if = rt->mfc_wrong_if;
       MFC_UNLOCK();
       return 0;
   }
   
   /*
    * returns the input and output packet and byte counts on the vif provided
    */
   static int
   get_vif_cnt(struct sioc_vif_req *req)
   {
       vifi_t vifi = req->vifi;
   
       VIF_LOCK();
       if (vifi >= numvifs) {
           VIF_UNLOCK();
           return EINVAL;
       }
   
       req->icount = viftable[vifi].v_pkt_in;
       req->ocount = viftable[vifi].v_pkt_out;
       req->ibytes = viftable[vifi].v_bytes_in;
       req->obytes = viftable[vifi].v_bytes_out;
       VIF_UNLOCK();
   
       return 0;
   }
   
   static void
   ip_mrouter_reset(void)
   {
   
       pim_assert_enabled = 0;
       mrt_api_config = 0;
   
       callout_init(&expire_upcalls_ch, CALLOUT_MPSAFE);
   
       bw_upcalls_n = 0;
       bzero((caddr_t)bw_meter_timers, sizeof(bw_meter_timers));
       callout_init(&bw_upcalls_ch, CALLOUT_MPSAFE);
       callout_init(&bw_meter_ch, CALLOUT_MPSAFE);
   }
   
   static void
   if_detached_event(void *arg __unused, struct ifnet *ifp)
   {
       vifi_t vifi;
       int i;
   
       MROUTER_LOCK();
   
       if (V_ip_mrouter == NULL) {
           MROUTER_UNLOCK();
           return;
       }
   
       VIF_LOCK();
       MFC_LOCK();
   
       /*
        * Tear down multicast forwarder state associated with this ifnet.
        * 1. Walk the vif list, matching vifs against this ifnet.
        * 2. Walk the multicast forwarding cache (mfc) looking for
        *    inner matches with this vif's index.
        * 3. Expire any matching multicast forwarding cache entries.
        * 4. Free vif state. This should disable ALLMULTI on the interface.
        */
       for (vifi = 0; vifi < numvifs; vifi++) {
           if (viftable[vifi].v_ifp != ifp)
                   continue;
           for (i = 0; i < mfchashsize; i++) {
                   struct mfc *rt, *nrt;
                   for (rt = LIST_FIRST(&mfchashtbl[i]); rt; rt = nrt) {
                           nrt = LIST_NEXT(rt, mfc_hash);
                           if (rt->mfc_parent == vifi) {
                                   expire_mfc(rt);
                           }
                   }
           }
           del_vif_locked(vifi);
       }
   
       MFC_UNLOCK();
       VIF_UNLOCK();
   
       MROUTER_UNLOCK();
   }
                           
   /*
    * Enable multicast forwarding.
    */
   static int
   ip_mrouter_init(struct socket *so, int version)
   {
   
       CTR3(KTR_IPMF, "%s: so_type %d, pr_protocol %d", __func__,
           so->so_type, so->so_proto->pr_protocol);
   
       if (so->so_type != SOCK_RAW || so->so_proto->pr_protocol != IPPROTO_IGMP)
           return EOPNOTSUPP;
   
       if (version != 1)
           return ENOPROTOOPT;
   
       MROUTER_LOCK();
   
       if (V_ip_mrouter != NULL) {
           MROUTER_UNLOCK();
           return EADDRINUSE;
       }
   
       if_detach_event_tag = EVENTHANDLER_REGISTER(ifnet_departure_event, 
           if_detached_event, NULL, EVENTHANDLER_PRI_ANY);
       if (if_detach_event_tag == NULL) {
           MROUTER_UNLOCK();
           return (ENOMEM);
       }
   
       mfchashtbl = hashinit_flags(mfchashsize, M_MRTABLE, &mfchash, HASH_NOWAIT);
   
       callout_reset(&expire_upcalls_ch, EXPIRE_TIMEOUT, expire_upcalls, NULL);
   
       callout_reset(&bw_upcalls_ch, BW_UPCALLS_PERIOD,
           expire_bw_upcalls_send, NULL);
       callout_reset(&bw_meter_ch, BW_METER_PERIOD, expire_bw_meter_process, NULL);
   
       V_ip_mrouter = so;
   
       MROUTER_UNLOCK();
   
       CTR1(KTR_IPMF, "%s: done", __func__);
   
       return 0;
   }
   
   /*
    * Disable multicast forwarding.
    */
   static int
   X_ip_mrouter_done(void)
   {
       vifi_t vifi;
       int i;
       struct ifnet *ifp;
       struct ifreq ifr;
   
       MROUTER_LOCK();
   
       if (V_ip_mrouter == NULL) {
           MROUTER_UNLOCK();
           return EINVAL;
       }
   
       /*
        * Detach/disable hooks to the reset of the system.
        */
       V_ip_mrouter = NULL;
       mrt_api_config = 0;
   
       VIF_LOCK();
   
       /*
        * For each phyint in use, disable promiscuous reception of all IP
        * multicasts.
        */
       for (vifi = 0; vifi < numvifs; vifi++) {
           if (!in_nullhost(viftable[vifi].v_lcl_addr) &&
                   !(viftable[vifi].v_flags & (VIFF_TUNNEL | VIFF_REGISTER))) {
               struct sockaddr_in *so = (struct sockaddr_in *)&(ifr.ifr_addr);
   
               so->sin_len = sizeof(struct sockaddr_in);
               so->sin_family = AF_INET;
               so->sin_addr.s_addr = INADDR_ANY;
               ifp = viftable[vifi].v_ifp;
               if_allmulti(ifp, 0);
           }
       }
       bzero((caddr_t)viftable, sizeof(viftable));
       numvifs = 0;
       pim_assert_enabled = 0;
   
       VIF_UNLOCK();
   
       EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_detach_event_tag);
   
       callout_stop(&expire_upcalls_ch);
       callout_stop(&bw_upcalls_ch);
       callout_stop(&bw_meter_ch);
   
       MFC_LOCK();
   
       /*
        * Free all multicast forwarding cache entries.
        * Do not use hashdestroy(), as we must perform other cleanup.
        */
       for (i = 0; i < mfchashsize; i++) {
           struct mfc *rt, *nrt;
           for (rt = LIST_FIRST(&mfchashtbl[i]); rt; rt = nrt) {
                   nrt = LIST_NEXT(rt, mfc_hash);
                   expire_mfc(rt);
           }
       }
       free(mfchashtbl, M_MRTABLE);
       mfchashtbl = NULL;
   
       bzero(nexpire, sizeof(nexpire[0]) * mfchashsize);
   
       bw_upcalls_n = 0;
       bzero(bw_meter_timers, sizeof(bw_meter_timers));
   
       MFC_UNLOCK();
   
       reg_vif_num = VIFI_INVALID;
   
       MROUTER_UNLOCK();
   
       CTR1(KTR_IPMF, "%s: done", __func__);
   
       return 0;
   }
   
   /*
    * Set PIM assert processing global
    */
   static int
   set_assert(int i)
   {
       if ((i != 1) && (i != 0))
           return EINVAL;
   
       pim_assert_enabled = i;
   
       return 0;
   }
   
   /*
    * Configure API capabilities
    */
   int
   set_api_config(uint32_t *apival)
   {
       int i;
   
       /*
        * We can set the API capabilities only if it is the first operation
        * after MRT_INIT. I.e.:
        *  - there are no vifs installed
        *  - pim_assert is not enabled
        *  - the MFC table is empty
        */
       if (numvifs > 0) {
           *apival = 0;
           return EPERM;
       }
       if (pim_assert_enabled) {
           *apival = 0;
           return EPERM;
       }
   
       MFC_LOCK();
   
       for (i = 0; i < mfchashsize; i++) {
           if (LIST_FIRST(&mfchashtbl[i]) != NULL) {
               *apival = 0;
               return EPERM;
           }
       }
   
       MFC_UNLOCK();
   
       mrt_api_config = *apival & mrt_api_support;
       *apival = mrt_api_config;
   
       return 0;
   }
   
   /*
    * Add a vif to the vif table
    */
   static int
   add_vif(struct vifctl *vifcp)
   {
       struct vif *vifp = viftable + vifcp->vifc_vifi;
       struct sockaddr_in sin = {sizeof sin, AF_INET};
       struct ifaddr *ifa;
       struct ifnet *ifp;
       int error;
   
       VIF_LOCK();
       if (vifcp->vifc_vifi >= MAXVIFS) {
           VIF_UNLOCK();
           return EINVAL;
       }
       /* rate limiting is no longer supported by this code */
       if (vifcp->vifc_rate_limit != 0) {
           log(LOG_ERR, "rate limiting is no longer supported\n");
           VIF_UNLOCK();
           return EINVAL;
       }
       if (!in_nullhost(vifp->v_lcl_addr)) {
           VIF_UNLOCK();
           return EADDRINUSE;
       }
       if (in_nullhost(vifcp->vifc_lcl_addr)) {
           VIF_UNLOCK();
           return EADDRNOTAVAIL;
       }
   
       /* Find the interface with an address in AF_INET family */
       if (vifcp->vifc_flags & VIFF_REGISTER) {
           /*
            * XXX: Because VIFF_REGISTER does not really need a valid
            * local interface (e.g. it could be 127.0.0.2), we don't
            * check its address.
            */
           ifp = NULL;
       } else {
           sin.sin_addr = vifcp->vifc_lcl_addr;
           ifa = ifa_ifwithaddr((struct sockaddr *)&sin);
           if (ifa == NULL) {
               VIF_UNLOCK();
               return EADDRNOTAVAIL;
           }
           ifp = ifa->ifa_ifp;
           ifa_free(ifa);
       }
   
       if ((vifcp->vifc_flags & VIFF_TUNNEL) != 0) {
           CTR1(KTR_IPMF, "%s: tunnels are no longer supported", __func__);
           VIF_UNLOCK();
           return EOPNOTSUPP;
       } else if (vifcp->vifc_flags & VIFF_REGISTER) {
           ifp = &multicast_register_if;
           CTR2(KTR_IPMF, "%s: add register vif for ifp %p", __func__, ifp);
           if (reg_vif_num == VIFI_INVALID) {
               if_initname(&multicast_register_if, "register_vif", 0);
               multicast_register_if.if_flags = IFF_LOOPBACK;
               reg_vif_num = vifcp->vifc_vifi;
           }
       } else {            /* Make sure the interface supports multicast */
           if ((ifp->if_flags & IFF_MULTICAST) == 0) {
               VIF_UNLOCK();
               return EOPNOTSUPP;
           }
   
           /* Enable promiscuous reception of all IP multicasts from the if */
           error = if_allmulti(ifp, 1);
           if (error) {
               VIF_UNLOCK();
               return error;
           }
       }
   
       vifp->v_flags     = vifcp->vifc_flags;
       vifp->v_threshold = vifcp->vifc_threshold;
       vifp->v_lcl_addr  = vifcp->vifc_lcl_addr;
       vifp->v_rmt_addr  = vifcp->vifc_rmt_addr;
       vifp->v_ifp       = ifp;
       /* initialize per vif pkt counters */
       vifp->v_pkt_in    = 0;
       vifp->v_pkt_out   = 0;
       vifp->v_bytes_in  = 0;
       vifp->v_bytes_out = 0;
       bzero(&vifp->v_route, sizeof(vifp->v_route));
   
       /* Adjust numvifs up if the vifi is higher than numvifs */
       if (numvifs <= vifcp->vifc_vifi)
           numvifs = vifcp->vifc_vifi + 1;
   
       VIF_UNLOCK();
   
       CTR4(KTR_IPMF, "%s: add vif %d laddr %s thresh %x", __func__,
           (int)vifcp->vifc_vifi, inet_ntoa(vifcp->vifc_lcl_addr),
           (int)vifcp->vifc_threshold);
   
       return 0;
   }
   
   /*
    * Delete a vif from the vif table
    */
   static int
   del_vif_locked(vifi_t vifi)
   {
       struct vif *vifp;
   
       VIF_LOCK_ASSERT();
   
       if (vifi >= numvifs) {
           return EINVAL;
       }
       vifp = &viftable[vifi];
       if (in_nullhost(vifp->v_lcl_addr)) {
           return EADDRNOTAVAIL;
       }
   
       if (!(vifp->v_flags & (VIFF_TUNNEL | VIFF_REGISTER)))
           if_allmulti(vifp->v_ifp, 0);
   
       if (vifp->v_flags & VIFF_REGISTER)
           reg_vif_num = VIFI_INVALID;
   
       bzero((caddr_t)vifp, sizeof (*vifp));
   
       CTR2(KTR_IPMF, "%s: delete vif %d", __func__, (int)vifi);
   
       /* Adjust numvifs down */
       for (vifi = numvifs; vifi > 0; vifi--)
           if (!in_nullhost(viftable[vifi-1].v_lcl_addr))
               break;
       numvifs = vifi;
   
       return 0;
   }
   
   static int
   del_vif(vifi_t vifi)
   {
       int cc;
   
       VIF_LOCK();
       cc = del_vif_locked(vifi);
       VIF_UNLOCK();
   
       return cc;
   }
   
   /*
    * update an mfc entry without resetting counters and S,G addresses.
    */
   static void
   update_mfc_params(struct mfc *rt, struct mfcctl2 *mfccp)
   {
       int i;
   
       rt->mfc_parent = mfccp->mfcc_parent;
       for (i = 0; i < numvifs; i++) {
           rt->mfc_ttls[i] = mfccp->mfcc_ttls[i];
           rt->mfc_flags[i] = mfccp->mfcc_flags[i] & mrt_api_config &
               MRT_MFC_FLAGS_ALL;
       }
       /* set the RP address */
       if (mrt_api_config & MRT_MFC_RP)
          rt->mfc_rp = mfccp->mfcc_rp;
      else
          rt->mfc_rp.s_addr = INADDR_ANY;
  }
  
  /*
   * fully initialize an mfc entry from the parameter.
   */
  static void
  init_mfc_params(struct mfc *rt, struct mfcctl2 *mfccp)
  {
      rt->mfc_origin     = mfccp->mfcc_origin;
      rt->mfc_mcastgrp   = mfccp->mfcc_mcastgrp;
  
      update_mfc_params(rt, mfccp);
  
      /* initialize pkt counters per src-grp */
      rt->mfc_pkt_cnt    = 0;
      rt->mfc_byte_cnt   = 0;
      rt->mfc_wrong_if   = 0;
      timevalclear(&rt->mfc_last_assert);
  }
  
  static void
  expire_mfc(struct mfc *rt)
  {
          struct rtdetq *rte, *nrte;
  
          free_bw_list(rt->mfc_bw_meter);
  
          TAILQ_FOREACH_SAFE(rte, &rt->mfc_stall, rte_link, nrte) {
                  m_freem(rte->m);
                  TAILQ_REMOVE(&rt->mfc_stall, rte, rte_link);
                  free(rte, M_MRTABLE);
          }
  
          LIST_REMOVE(rt, mfc_hash);
          free(rt, M_MRTABLE);
  }
  
  /*
   * Add an mfc entry
   */
  static int
  add_mfc(struct mfcctl2 *mfccp)
  {
      struct mfc *rt;
      struct rtdetq *rte, *nrte;
      u_long hash = 0;
      u_short nstl;
  
      VIF_LOCK();
      MFC_LOCK();
  
      rt = mfc_find(&mfccp->mfcc_origin, &mfccp->mfcc_mcastgrp);
  
      /* If an entry already exists, just update the fields */
      if (rt) {
          CTR4(KTR_IPMF, "%s: update mfc orig %s group %lx parent %x",
              __func__, inet_ntoa(mfccp->mfcc_origin),
              (u_long)ntohl(mfccp->mfcc_mcastgrp.s_addr),
              mfccp->mfcc_parent);
          update_mfc_params(rt, mfccp);
          MFC_UNLOCK();
          VIF_UNLOCK();
          return (0);
      }
  
      /*
       * Find the entry for which the upcall was made and update
       */
      nstl = 0;
      hash = MFCHASH(mfccp->mfcc_origin, mfccp->mfcc_mcastgrp);
      LIST_FOREACH(rt, &mfchashtbl[hash], mfc_hash) {
          if (in_hosteq(rt->mfc_origin, mfccp->mfcc_origin) &&
              in_hosteq(rt->mfc_mcastgrp, mfccp->mfcc_mcastgrp) &&
              !TAILQ_EMPTY(&rt->mfc_stall)) {
                  CTR5(KTR_IPMF,
                      "%s: add mfc orig %s group %lx parent %x qh %p",
                      __func__, inet_ntoa(mfccp->mfcc_origin),
                      (u_long)ntohl(mfccp->mfcc_mcastgrp.s_addr),
                      mfccp->mfcc_parent,
                      TAILQ_FIRST(&rt->mfc_stall));
                  if (nstl++)
                          CTR1(KTR_IPMF, "%s: multiple matches", __func__);
  
                  init_mfc_params(rt, mfccp);
                  rt->mfc_expire = 0;     /* Don't clean this guy up */
                  nexpire[hash]--;
  
                  /* Free queued packets, but attempt to forward them first. */
                  TAILQ_FOREACH_SAFE(rte, &rt->mfc_stall, rte_link, nrte) {
                          if (rte->ifp != NULL)
                                  ip_mdq(rte->m, rte->ifp, rt, -1);
                          m_freem(rte->m);
                          TAILQ_REMOVE(&rt->mfc_stall, rte, rte_link);
                          rt->mfc_nstall--;
                          free(rte, M_MRTABLE);
                  }
          }
      }
  
      /*
       * It is possible that an entry is being inserted without an upcall
       */
      if (nstl == 0) {
          CTR1(KTR_IPMF, "%s: adding mfc w/o upcall", __func__);
          LIST_FOREACH(rt, &mfchashtbl[hash], mfc_hash) {
                  if (in_hosteq(rt->mfc_origin, mfccp->mfcc_origin) &&
                      in_hosteq(rt->mfc_mcastgrp, mfccp->mfcc_mcastgrp)) {
                          init_mfc_params(rt, mfccp);
                          if (rt->mfc_expire)
                              nexpire[hash]--;
                          rt->mfc_expire = 0;
                          break; /* XXX */
                  }
          }
  
          if (rt == NULL) {               /* no upcall, so make a new entry */
              rt = (struct mfc *)malloc(sizeof(*rt), M_MRTABLE, M_NOWAIT);
              if (rt == NULL) {
                  MFC_UNLOCK();
                  VIF_UNLOCK();
                  return (ENOBUFS);
              }
  
              init_mfc_params(rt, mfccp);
              TAILQ_INIT(&rt->mfc_stall);
              rt->mfc_nstall = 0;
  
              rt->mfc_expire     = 0;
              rt->mfc_bw_meter = NULL;
  
              /* insert new entry at head of hash chain */
              LIST_INSERT_HEAD(&mfchashtbl[hash], rt, mfc_hash);
          }
      }
  
      MFC_UNLOCK();
      VIF_UNLOCK();
  
      return (0);
  }
  
  /*
   * Delete an mfc entry
   */
  static int
  del_mfc(struct mfcctl2 *mfccp)
  {
      struct in_addr      origin;
      struct in_addr      mcastgrp;
      struct mfc          *rt;
  
      origin = mfccp->mfcc_origin;
      mcastgrp = mfccp->mfcc_mcastgrp;
  
      CTR3(KTR_IPMF, "%s: delete mfc orig %s group %lx", __func__,
          inet_ntoa(origin), (u_long)ntohl(mcastgrp.s_addr));
  
      MFC_LOCK();
  
      rt = mfc_find(&origin, &mcastgrp);
      if (rt == NULL) {
          MFC_UNLOCK();
          return EADDRNOTAVAIL;
      }
  
      /*
       * free the bw_meter entries
       */
      free_bw_list(rt->mfc_bw_meter);
      rt->mfc_bw_meter = NULL;
  
      LIST_REMOVE(rt, mfc_hash);
      free(rt, M_MRTABLE);
  
      MFC_UNLOCK();
  
      return (0);
  }
  
  /*
   * Send a message to the routing daemon on the multicast routing socket.
   */
  static int
  socket_send(struct socket *s, struct mbuf *mm, struct sockaddr_in *src)
  {
      if (s) {
          SOCKBUF_LOCK(&s->so_rcv);
          if (sbappendaddr_locked(&s->so_rcv, (struct sockaddr *)src, mm,
              NULL) != 0) {
              sorwakeup_locked(s);
              return 0;
          }
          SOCKBUF_UNLOCK(&s->so_rcv);
      }
      m_freem(mm);
      return -1;
  }
  
  /*
   * IP multicast forwarding function. This function assumes that the packet
   * pointed to by "ip" 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 IP 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.
   */
  
  #define TUNNEL_LEN  12  /* # bytes of IP option for tunnel encapsulation  */
  
  static int
  X_ip_mforward(struct ip *ip, struct ifnet *ifp, struct mbuf *m,
      struct ip_moptions *imo)
  {
      struct mfc *rt;
      int error;
      vifi_t vifi;
  
      CTR3(KTR_IPMF, "ip_mforward: delete mfc orig %s group %lx ifp %p",
          inet_ntoa(ip->ip_src), (u_long)ntohl(ip->ip_dst.s_addr), ifp);
  
      if (ip->ip_hl < (sizeof(struct ip) + TUNNEL_LEN) >> 2 ||
                  ((u_char *)(ip + 1))[1] != IPOPT_LSRR ) {
          /*
           * Packet arrived via a physical interface or
           * an encapsulated tunnel or a register_vif.
           */
      } else {
          /*
           * Packet arrived through a source-route tunnel.
           * Source-route tunnels are no longer supported.
           */
          return (1);
      }
  
      VIF_LOCK();
      MFC_LOCK();
      if (imo && ((vifi = imo->imo_multicast_vif) < numvifs)) {
          if (ip->ip_ttl < MAXTTL)
              ip->ip_ttl++;       /* compensate for -1 in *_send routines */
          error = ip_mdq(m, ifp, NULL, vifi);
          MFC_UNLOCK();
          VIF_UNLOCK();
          return error;
      }
  
      /*
       * Don't forward a packet with time-to-live of zero or one,
       * or a packet destined to a local-only group.
       */
      if (ip->ip_ttl <= 1 || IN_LOCAL_GROUP(ntohl(ip->ip_dst.s_addr))) {
          MFC_UNLOCK();
          VIF_UNLOCK();
          return 0;
      }
  
      /*
       * Determine forwarding vifs from the forwarding cache table
       */
      MRTSTAT_INC(mrts_mfc_lookups);
      rt = mfc_find(&ip->ip_src, &ip->ip_dst);
  
      /* Entry exists, so forward if necessary */
      if (rt != NULL) {
          error = ip_mdq(m, ifp, rt, -1);
          MFC_UNLOCK();
          VIF_UNLOCK();
          return error;
      } else {
          /*
           * If we don't have a route for packet's origin,
           * Make a copy of the packet & send message to routing daemon
           */
  
          struct mbuf *mb0;
          struct rtdetq *rte;
          u_long hash;
          int hlen = ip->ip_hl << 2;
  
          MRTSTAT_INC(mrts_mfc_misses);
          MRTSTAT_INC(mrts_no_route);
          CTR2(KTR_IPMF, "ip_mforward: no mfc for (%s,%lx)",
              inet_ntoa(ip->ip_src), (u_long)ntohl(ip->ip_dst.s_addr));
  
          /*
           * Allocate mbufs early so that we don't do extra work if we are
           * just going to fail anyway.  Make sure to pullup the header so
           * that other people can't step on it.
           */
          rte = (struct rtdetq *)malloc((sizeof *rte), M_MRTABLE,
              M_NOWAIT|M_ZERO);
          if (rte == NULL) {
              MFC_UNLOCK();
              VIF_UNLOCK();
              return ENOBUFS;
          }
  
          mb0 = m_copypacket(m, M_DONTWAIT);
          if (mb0 && (M_HASCL(mb0) || mb0->m_len < hlen))
              mb0 = m_pullup(mb0, hlen);
          if (mb0 == NULL) {
              free(rte, M_MRTABLE);
              MFC_UNLOCK();
              VIF_UNLOCK();
              return ENOBUFS;
          }
  
          /* is there an upcall waiting for this flow ? */
          hash = MFCHASH(ip->ip_src, ip->ip_dst);
          LIST_FOREACH(rt, &mfchashtbl[hash], mfc_hash) {
                  if (in_hosteq(ip->ip_src, rt->mfc_origin) &&
                      in_hosteq(ip->ip_dst, rt->mfc_mcastgrp) &&
                      !TAILQ_EMPTY(&rt->mfc_stall))
                          break;
          }
  
          if (rt == NULL) {
              int i;
              struct igmpmsg *im;
              struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
              struct mbuf *mm;
  
              /*
               * Locate the vifi for the incoming interface for this packet.
               * If none found, drop packet.
               */
              for (vifi = 0; vifi < numvifs &&
                      viftable[vifi].v_ifp != ifp; vifi++)
                  ;
              if (vifi >= numvifs)        /* vif not found, drop packet */
                  goto non_fatal;
  
              /* no upcall, so make a new entry */
              rt = (struct mfc *)malloc(sizeof(*rt), M_MRTABLE, M_NOWAIT);
              if (rt == NULL)
                  goto fail;
  
              /* Make a copy of the header to send to the user level process */
              mm = m_copy(mb0, 0, hlen);
              if (mm == NULL)
                  goto fail1;
  
              /*
               * Send message to routing daemon to install
               * a route into the kernel table
               */
  
              im = mtod(mm, struct igmpmsg *);
              im->im_msgtype = IGMPMSG_NOCACHE;
              im->im_mbz = 0;
              im->im_vif = vifi;
  
              MRTSTAT_INC(mrts_upcalls);
  
              k_igmpsrc.sin_addr = ip->ip_src;
              if (socket_send(V_ip_mrouter, mm, &k_igmpsrc) < 0) {
                  CTR0(KTR_IPMF, "ip_mforward: socket queue full");
                  MRTSTAT_INC(mrts_upq_sockfull);
  fail1:
                  free(rt, M_MRTABLE);
  fail:
                  free(rte, M_MRTABLE);
                  m_freem(mb0);
                  MFC_UNLOCK();
                  VIF_UNLOCK();
                  return ENOBUFS;
              }
  
              /* insert new entry at head of hash chain */
              rt->mfc_origin.s_addr     = ip->ip_src.s_addr;
              rt->mfc_mcastgrp.s_addr   = ip->ip_dst.s_addr;
              rt->mfc_expire            = UPCALL_EXPIRE;
              nexpire[hash]++;
              for (i = 0; i < numvifs; i++) {
                  rt->mfc_ttls[i] = 0;
                  rt->mfc_flags[i] = 0;
              }
              rt->mfc_parent = -1;
  
              /* clear the RP address */
              rt->mfc_rp.s_addr = INADDR_ANY;
              rt->mfc_bw_meter = NULL;
  
              /* initialize pkt counters per src-grp */
              rt->mfc_pkt_cnt = 0;
              rt->mfc_byte_cnt = 0;
              rt->mfc_wrong_if = 0;
              timevalclear(&rt->mfc_last_assert);
  
              TAILQ_INIT(&rt->mfc_stall);
              rt->mfc_nstall = 0;
  
              /* link into table */
              LIST_INSERT_HEAD(&mfchashtbl[hash], rt, mfc_hash);
              TAILQ_INSERT_HEAD(&rt->mfc_stall, rte, rte_link);
              rt->mfc_nstall++;
  
          } else {
              /* determine if queue has overflowed */
              if (rt->mfc_nstall > MAX_UPQ) {
                  MRTSTAT_INC(mrts_upq_ovflw);
  non_fatal:
                  free(rte, M_MRTABLE);
                  m_freem(mb0);
                  MFC_UNLOCK();
                  VIF_UNLOCK();
                  return (0);
              }
              TAILQ_INSERT_TAIL(&rt->mfc_stall, rte, rte_link);
              rt->mfc_nstall++;
          }
  
          rte->m                  = mb0;
          rte->ifp                = ifp;
  
          MFC_UNLOCK();
          VIF_UNLOCK();
  
          return 0;
      }
  }
  
  /*
   * Clean up the cache entry if upcall is not serviced
   */
  static void
  expire_upcalls(void *unused)
  {
      int i;
  
      MFC_LOCK();
  
      for (i = 0; i < mfchashsize; i++) {
          struct mfc *rt, *nrt;
  
          if (nexpire[i] == 0)
              continue;
  
          for (rt = LIST_FIRST(&mfchashtbl[i]); rt; rt = nrt) {
                  nrt = LIST_NEXT(rt, mfc_hash);
  
                  if (TAILQ_EMPTY(&rt->mfc_stall))
                          continue;
  
                  if (rt->mfc_expire == 0 || --rt->mfc_expire > 0)
                          continue;
  
                  /*
                   * free the bw_meter entries
                   */
                  while (rt->mfc_bw_meter != NULL) {
                      struct bw_meter *x = rt->mfc_bw_meter;
  
                      rt->mfc_bw_meter = x->bm_mfc_next;
                      free(x, M_BWMETER);
                  }
  
                  MRTSTAT_INC(mrts_cache_cleanups);
                  CTR3(KTR_IPMF, "%s: expire (%lx, %lx)", __func__,
                      (u_long)ntohl(rt->mfc_origin.s_addr),
                      (u_long)ntohl(rt->mfc_mcastgrp.s_addr));
  
                  expire_mfc(rt);
              }
      }
  
      MFC_UNLOCK();
  
      callout_reset(&expire_upcalls_ch, EXPIRE_TIMEOUT, expire_upcalls, NULL);
  }
  
  /*
   * Packet forwarding routine once entry in the cache is made
   */
  static int
  ip_mdq(struct mbuf *m, struct ifnet *ifp, struct mfc *rt, vifi_t xmt_vif)
  {
      struct ip  *ip = mtod(m, struct ip *);
      vifi_t vifi;
      int plen = ip->ip_len;
  
      VIF_LOCK_ASSERT();
  
      /*
       * If xmt_vif is not -1, send on only the requested vif.
       *
       * (since vifi_t is u_short, -1 becomes MAXUSHORT, which > numvifs.)
       */
      if (xmt_vif < numvifs) {
          if (viftable[xmt_vif].v_flags & VIFF_REGISTER)
                  pim_register_send(ip, viftable + xmt_vif, m, rt);
          else
                  phyint_send(ip, viftable + xmt_vif, m);
          return 1;
      }
  
      /*
       * Don't forward if it didn't arrive from the parent vif for its origin.
       */
      vifi = rt->mfc_parent;
      if ((vifi >= numvifs) || (viftable[vifi].v_ifp != ifp)) {
          CTR4(KTR_IPMF, "%s: rx on wrong ifp %p (vifi %d, v_ifp %p)",
              __func__, ifp, (int)vifi, viftable[vifi].v_ifp);
          MRTSTAT_INC(mrts_wrong_if);
          ++rt->mfc_wrong_if;
          /*
           * If we are doing PIM assert processing, send a message
           * to the routing daemon.
           *
           * XXX: A PIM-SM router needs the WRONGVIF detection so it
           * can complete the SPT switch, regardless of the type
           * of the iif (broadcast media, GRE tunnel, etc).
           */
          if (pim_assert_enabled && (vifi < numvifs) && viftable[vifi].v_ifp) {
  
              if (ifp == &multicast_register_if)
                  PIMSTAT_INC(pims_rcv_registers_wrongiif);
  
              /* Get vifi for the incoming packet */
              for (vifi=0; vifi < numvifs && viftable[vifi].v_ifp != ifp; vifi++)
                  ;
              if (vifi >= numvifs)
                  return 0;       /* The iif is not found: ignore the packet. */
  
              if (rt->mfc_flags[vifi] & MRT_MFC_FLAGS_DISABLE_WRONGVIF)
                  return 0;       /* WRONGVIF disabled: ignore the packet */
  
              if (ratecheck(&rt->mfc_last_assert, &pim_assert_interval)) {
                  struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
                  struct igmpmsg *im;
                  int hlen = ip->ip_hl << 2;
                  struct mbuf *mm = m_copy(m, 0, hlen);
  
                  if (mm && (M_HASCL(mm) || mm->m_len < hlen))
                      mm = m_pullup(mm, hlen);
                  if (mm == NULL)
                      return ENOBUFS;
  
                  im = mtod(mm, struct igmpmsg *);
                  im->im_msgtype  = IGMPMSG_WRONGVIF;
                  im->im_mbz              = 0;
                  im->im_vif              = vifi;
  
                  MRTSTAT_INC(mrts_upcalls);
  
                  k_igmpsrc.sin_addr = im->im_src;
                  if (socket_send(V_ip_mrouter, mm, &k_igmpsrc) < 0) {
                      CTR1(KTR_IPMF, "%s: socket queue full", __func__);
                      MRTSTAT_INC(mrts_upq_sockfull);
                      return ENOBUFS;
                  }
              }
          }
          return 0;
      }
  
  
      /* If I sourced this packet, it counts as output, else it was input. */
      if (in_hosteq(ip->ip_src, viftable[vifi].v_lcl_addr)) {
          viftable[vifi].v_pkt_out++;
          viftable[vifi].v_bytes_out += plen;
      } else {
          viftable[vifi].v_pkt_in++;
          viftable[vifi].v_bytes_in += plen;
      }
      rt->mfc_pkt_cnt++;
      rt->mfc_byte_cnt += plen;
  
      /*
       * For each vif, decide if a copy of the packet should be forwarded.
       * Forward if:
       *          - the ttl exceeds the vif's threshold
       *          - there are group members downstream on interface
       */
      for (vifi = 0; vifi < numvifs; vifi++)
          if ((rt->mfc_ttls[vifi] > 0) && (ip->ip_ttl > rt->mfc_ttls[vifi])) {
              viftable[vifi].v_pkt_out++;
              viftable[vifi].v_bytes_out += plen;
              if (viftable[vifi].v_flags & VIFF_REGISTER)
                  pim_register_send(ip, viftable + vifi, m, rt);
              else
                  phyint_send(ip, viftable + vifi, m);
          }
  
      /*
       * Perform upcall-related bw measuring.
       */
      if (rt->mfc_bw_meter != NULL) {
          struct bw_meter *x;
          struct timeval now;
  
          microtime(&now);
          MFC_LOCK_ASSERT();
          for (x = rt->mfc_bw_meter; x != NULL; x = x->bm_mfc_next)
              bw_meter_receive_packet(x, plen, &now);
      }
  
      return 0;
  }
  
  /*
   * Check if a vif number is legal/ok. This is used by in_mcast.c.
   */
  static int
  X_legal_vif_num(int vif)
  {
          int ret;
  
          ret = 0;
          if (vif < 0)
                  return (ret);
  
          VIF_LOCK();
          if (vif < numvifs)
                  ret = 1;
          VIF_UNLOCK();
  
          return (ret);
  }
  
  /*
   * Return the local address used by this vif
   */
  static u_long
  X_ip_mcast_src(int vifi)
  {
          in_addr_t addr;
  
          addr = INADDR_ANY;
          if (vifi < 0)
                  return (addr);
  
          VIF_LOCK();
          if (vifi < numvifs)
                  addr = viftable[vifi].v_lcl_addr.s_addr;
          VIF_UNLOCK();
  
          return (addr);
  }
  
  static void
  phyint_send(struct ip *ip, struct vif *vifp, struct mbuf *m)
  {
      struct mbuf *mb_copy;
      int hlen = ip->ip_hl << 2;
  
      VIF_LOCK_ASSERT();
  
      /*
       * Make a new reference to the packet; make sure that
       * the IP header is actually copied, not just referenced,
       * so that ip_output() only scribbles on the copy.
       */
      mb_copy = m_copypacket(m, M_DONTWAIT);
      if (mb_copy && (M_HASCL(mb_copy) || mb_copy->m_len < hlen))
          mb_copy = m_pullup(mb_copy, hlen);
      if (mb_copy == NULL)
          return;
  
      send_packet(vifp, mb_copy);
  }
  
  static void
  send_packet(struct vif *vifp, struct mbuf *m)
  {
          struct ip_moptions imo;
          struct in_multi *imm[2];
          int error;
  
          VIF_LOCK_ASSERT();
  
          imo.imo_multicast_ifp  = vifp->v_ifp;
          imo.imo_multicast_ttl  = mtod(m, struct ip *)->ip_ttl - 1;
          imo.imo_multicast_loop = 1;
          imo.imo_multicast_vif  = -1;
          imo.imo_num_memberships = 0;
          imo.imo_max_memberships = 2;
          imo.imo_membership  = &imm[0];
  
          /*
           * Re-entrancy should not be a problem here, because
           * the packets that we send out and are looped back at us
           * should get rejected because they appear to come from
           * the loopback interface, thus preventing looping.
           */
          error = ip_output(m, NULL, &vifp->v_route, IP_FORWARDING, &imo, NULL);
          CTR3(KTR_IPMF, "%s: vif %td err %d", __func__,
              (ptrdiff_t)(vifp - viftable), error);
  }
  
  /*
   * Stubs for old RSVP socket shim implementation.
   */
  
  static int
  X_ip_rsvp_vif(struct socket *so __unused, struct sockopt *sopt __unused)
  {
  
          return (EOPNOTSUPP);
  }
  
  static void
  X_ip_rsvp_force_done(struct socket *so __unused)
  {
  
  }
  
  static void
  X_rsvp_input(struct mbuf *m, int off __unused)
  {
  
          if (!V_rsvp_on)
                  m_freem(m);
  }
  
  /*
   * Code for bandwidth monitors
   */
  
  /*
   * Define common interface for timeval-related methods
   */
  #define BW_TIMEVALCMP(tvp, uvp, cmp) timevalcmp((tvp), (uvp), cmp)
  #define BW_TIMEVALDECR(vvp, uvp) timevalsub((vvp), (uvp))
  #define BW_TIMEVALADD(vvp, uvp) timevaladd((vvp), (uvp))
  
  static uint32_t
  compute_bw_meter_flags(struct bw_upcall *req)
  {
      uint32_t flags = 0;
  
      if (req->bu_flags & BW_UPCALL_UNIT_PACKETS)
          flags |= BW_METER_UNIT_PACKETS;
      if (req->bu_flags & BW_UPCALL_UNIT_BYTES)
          flags |= BW_METER_UNIT_BYTES;
      if (req->bu_flags & BW_UPCALL_GEQ)
          flags |= BW_METER_GEQ;
      if (req->bu_flags & BW_UPCALL_LEQ)
          flags |= BW_METER_LEQ;
  
      return flags;
  }
  
  /*
   * Add a bw_meter entry
   */
  static int
  add_bw_upcall(struct bw_upcall *req)
  {
      struct mfc *mfc;
      struct timeval delta = { BW_UPCALL_THRESHOLD_INTERVAL_MIN_SEC,
                  BW_UPCALL_THRESHOLD_INTERVAL_MIN_USEC };
      struct timeval now;
      struct bw_meter *x;
      uint32_t flags;
  
      if (!(mrt_api_config & MRT_MFC_BW_UPCALL))
          return EOPNOTSUPP;
  
      /* Test if the flags are valid */
      if (!(req->bu_flags & (BW_UPCALL_UNIT_PACKETS | BW_UPCALL_UNIT_BYTES)))
          return EINVAL;
      if (!(req->bu_flags & (BW_UPCALL_GEQ | BW_UPCALL_LEQ)))
          return EINVAL;
      if ((req->bu_flags & (BW_UPCALL_GEQ | BW_UPCALL_LEQ))
              == (BW_UPCALL_GEQ | BW_UPCALL_LEQ))
          return EINVAL;
  
      /* Test if the threshold time interval is valid */
      if (BW_TIMEVALCMP(&req->bu_threshold.b_time, &delta, <))
          return EINVAL;
  
      flags = compute_bw_meter_flags(req);
  
      /*
       * Find if we have already same bw_meter entry
       */
      MFC_LOCK();
      mfc = mfc_find(&req->bu_src, &req->bu_dst);
      if (mfc == NULL) {
          MFC_UNLOCK();
          return EADDRNOTAVAIL;
      }
      for (x = mfc->mfc_bw_meter; x != NULL; x = x->bm_mfc_next) {
          if ((BW_TIMEVALCMP(&x->bm_threshold.b_time,
                             &req->bu_threshold.b_time, ==)) &&
              (x->bm_threshold.b_packets == req->bu_threshold.b_packets) &&
              (x->bm_threshold.b_bytes == req->bu_threshold.b_bytes) &&
              (x->bm_flags & BW_METER_USER_FLAGS) == flags)  {
              MFC_UNLOCK();
              return 0;           /* XXX Already installed */
          }
      }
  
      /* Allocate the new bw_meter entry */
      x = (struct bw_meter *)malloc(sizeof(*x), M_BWMETER, M_NOWAIT);
      if (x == NULL) {
          MFC_UNLOCK();
          return ENOBUFS;
      }
  
      /* Set the new bw_meter entry */
      x->bm_threshold.b_time = req->bu_threshold.b_time;
      microtime(&now);
      x->bm_start_time = now;
      x->bm_threshold.b_packets = req->bu_threshold.b_packets;
      x->bm_threshold.b_bytes = req->bu_threshold.b_bytes;
      x->bm_measured.b_packets = 0;
      x->bm_measured.b_bytes = 0;
      x->bm_flags = flags;
      x->bm_time_next = NULL;
      x->bm_time_hash = BW_METER_BUCKETS;
  
      /* Add the new bw_meter entry to the front of entries for this MFC */
      x->bm_mfc = mfc;
      x->bm_mfc_next = mfc->mfc_bw_meter;
      mfc->mfc_bw_meter = x;
      schedule_bw_meter(x, &now);
      MFC_UNLOCK();
  
      return 0;
  }
  
  static void
  free_bw_list(struct bw_meter *list)
  {
      while (list != NULL) {
          struct bw_meter *x = list;
  
          list = list->bm_mfc_next;
          unschedule_bw_meter(x);
          free(x, M_BWMETER);
      }
  }
  
  /*
   * Delete one or multiple bw_meter entries
   */
  static int
  del_bw_upcall(struct bw_upcall *req)
  {
      struct mfc *mfc;
      struct bw_meter *x;
  
      if (!(mrt_api_config & MRT_MFC_BW_UPCALL))
          return EOPNOTSUPP;
  
      MFC_LOCK();
  
      /* Find the corresponding MFC entry */
      mfc = mfc_find(&req->bu_src, &req->bu_dst);
      if (mfc == NULL) {
          MFC_UNLOCK();
          return EADDRNOTAVAIL;
      } else if (req->bu_flags & BW_UPCALL_DELETE_ALL) {
          /*
           * Delete all bw_meter entries for this mfc
           */
          struct bw_meter *list;
  
          list = mfc->mfc_bw_meter;
          mfc->mfc_bw_meter = NULL;
          free_bw_list(list);
          MFC_UNLOCK();
          return 0;
      } else {                    /* Delete a single bw_meter entry */
          struct bw_meter *prev;
          uint32_t flags = 0;
  
          flags = compute_bw_meter_flags(req);
  
          /* Find the bw_meter entry to delete */
          for (prev = NULL, x = mfc->mfc_bw_meter; x != NULL;
               prev = x, x = x->bm_mfc_next) {
              if ((BW_TIMEVALCMP(&x->bm_threshold.b_time,
                                 &req->bu_threshold.b_time, ==)) &&
                  (x->bm_threshold.b_packets == req->bu_threshold.b_packets) &&
                  (x->bm_threshold.b_bytes == req->bu_threshold.b_bytes) &&
                  (x->bm_flags & BW_METER_USER_FLAGS) == flags)
                  break;
          }
          if (x != NULL) { /* Delete entry from the list for this MFC */
              if (prev != NULL)
                  prev->bm_mfc_next = x->bm_mfc_next;     /* remove from middle*/
              else
                  x->bm_mfc->mfc_bw_meter = x->bm_mfc_next;/* new head of list */
  
              unschedule_bw_meter(x);
              MFC_UNLOCK();
              /* Free the bw_meter entry */
              free(x, M_BWMETER);
              return 0;
          } else {
              MFC_UNLOCK();
              return EINVAL;
          }
      }
      /* NOTREACHED */
  }
  
  /*
   * Perform bandwidth measurement processing that may result in an upcall
   */
  static void
  bw_meter_receive_packet(struct bw_meter *x, int plen, struct timeval *nowp)
  {
      struct timeval delta;
  
      MFC_LOCK_ASSERT();
  
      delta = *nowp;
      BW_TIMEVALDECR(&delta, &x->bm_start_time);
  
      if (x->bm_flags & BW_METER_GEQ) {
          /*
           * Processing for ">=" type of bw_meter entry
           */
          if (BW_TIMEVALCMP(&delta, &x->bm_threshold.b_time, >)) {
              /* Reset the bw_meter entry */
              x->bm_start_time = *nowp;
              x->bm_measured.b_packets = 0;
              x->bm_measured.b_bytes = 0;
              x->bm_flags &= ~BW_METER_UPCALL_DELIVERED;
          }
  
          /* Record that a packet is received */
          x->bm_measured.b_packets++;
          x->bm_measured.b_bytes += plen;
  
          /*
           * Test if we should deliver an upcall
           */
          if (!(x->bm_flags & BW_METER_UPCALL_DELIVERED)) {
              if (((x->bm_flags & BW_METER_UNIT_PACKETS) &&
                   (x->bm_measured.b_packets >= x->bm_threshold.b_packets)) ||
                  ((x->bm_flags & BW_METER_UNIT_BYTES) &&
                   (x->bm_measured.b_bytes >= x->bm_threshold.b_bytes))) {
                  /* Prepare an upcall for delivery */
                  bw_meter_prepare_upcall(x, nowp);
                  x->bm_flags |= BW_METER_UPCALL_DELIVERED;
              }
          }
      } else if (x->bm_flags & BW_METER_LEQ) {
          /*
           * Processing for "<=" type of bw_meter entry
           */
          if (BW_TIMEVALCMP(&delta, &x->bm_threshold.b_time, >)) {
              /*
               * We are behind time with the multicast forwarding table
               * scanning for "<=" type of bw_meter entries, so test now
               * if we should deliver an upcall.
               */
              if (((x->bm_flags & BW_METER_UNIT_PACKETS) &&
                   (x->bm_measured.b_packets <= x->bm_threshold.b_packets)) ||
                  ((x->bm_flags & BW_METER_UNIT_BYTES) &&
                   (x->bm_measured.b_bytes <= x->bm_threshold.b_bytes))) {
                  /* Prepare an upcall for delivery */
                  bw_meter_prepare_upcall(x, nowp);
              }
              /* Reschedule the bw_meter entry */
              unschedule_bw_meter(x);
              schedule_bw_meter(x, nowp);
          }
  
          /* Record that a packet is received */
          x->bm_measured.b_packets++;
          x->bm_measured.b_bytes += plen;
  
          /*
           * Test if we should restart the measuring interval
           */
          if ((x->bm_flags & BW_METER_UNIT_PACKETS &&
               x->bm_measured.b_packets <= x->bm_threshold.b_packets) ||
              (x->bm_flags & BW_METER_UNIT_BYTES &&
               x->bm_measured.b_bytes <= x->bm_threshold.b_bytes)) {
              /* Don't restart the measuring interval */
          } else {
              /* Do restart the measuring interval */
              /*
               * XXX: note that we don't unschedule and schedule, because this
               * might be too much overhead per packet. Instead, when we process
               * all entries for a given timer hash bin, we check whether it is
               * really a timeout. If not, we reschedule at that time.
               */
              x->bm_start_time = *nowp;
              x->bm_measured.b_packets = 0;
              x->bm_measured.b_bytes = 0;
              x->bm_flags &= ~BW_METER_UPCALL_DELIVERED;
          }
      }
  }
  
  /*
   * Prepare a bandwidth-related upcall
   */
  static void
  bw_meter_prepare_upcall(struct bw_meter *x, struct timeval *nowp)
  {
      struct timeval delta;
      struct bw_upcall *u;
  
      MFC_LOCK_ASSERT();
  
      /*
       * Compute the measured time interval
       */
      delta = *nowp;
      BW_TIMEVALDECR(&delta, &x->bm_start_time);
  
      /*
       * If there are too many pending upcalls, deliver them now
       */
      if (bw_upcalls_n >= BW_UPCALLS_MAX)
          bw_upcalls_send();
  
      /*
       * Set the bw_upcall entry
       */
      u = &bw_upcalls[bw_upcalls_n++];
      u->bu_src = x->bm_mfc->mfc_origin;
      u->bu_dst = x->bm_mfc->mfc_mcastgrp;
      u->bu_threshold.b_time = x->bm_threshold.b_time;
      u->bu_threshold.b_packets = x->bm_threshold.b_packets;
      u->bu_threshold.b_bytes = x->bm_threshold.b_bytes;
      u->bu_measured.b_time = delta;
      u->bu_measured.b_packets = x->bm_measured.b_packets;
      u->bu_measured.b_bytes = x->bm_measured.b_bytes;
      u->bu_flags = 0;
      if (x->bm_flags & BW_METER_UNIT_PACKETS)
          u->bu_flags |= BW_UPCALL_UNIT_PACKETS;
      if (x->bm_flags & BW_METER_UNIT_BYTES)
          u->bu_flags |= BW_UPCALL_UNIT_BYTES;
      if (x->bm_flags & BW_METER_GEQ)
          u->bu_flags |= BW_UPCALL_GEQ;
      if (x->bm_flags & BW_METER_LEQ)
          u->bu_flags |= BW_UPCALL_LEQ;
  }
  
  /*
   * Send the pending bandwidth-related upcalls
   */
  static void
  bw_upcalls_send(void)
  {
      struct mbuf *m;
      int len = bw_upcalls_n * sizeof(bw_upcalls[0]);
      struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
      static struct igmpmsg igmpmsg = { 0,                /* unused1 */
                                        0,                /* unused2 */
                                        IGMPMSG_BW_UPCALL,/* im_msgtype */
                                        0,                /* im_mbz  */
                                        0,                /* im_vif  */
                                        0,                /* unused3 */
                                        { 0 },            /* im_src  */
                                        { 0 } };          /* im_dst  */
  
      MFC_LOCK_ASSERT();
  
      if (bw_upcalls_n == 0)
          return;                 /* No pending upcalls */
  
      bw_upcalls_n = 0;
  
      /*
       * Allocate a new mbuf, initialize it with the header and
       * the payload for the pending calls.
       */
      MGETHDR(m, M_DONTWAIT, MT_DATA);
      if (m == NULL) {
          log(LOG_WARNING, "bw_upcalls_send: cannot allocate mbuf\n");
          return;
      }
  
      m->m_len = m->m_pkthdr.len = 0;
      m_copyback(m, 0, sizeof(struct igmpmsg), (caddr_t)&igmpmsg);
      m_copyback(m, sizeof(struct igmpmsg), len, (caddr_t)&bw_upcalls[0]);
  
      /*
       * Send the upcalls
       * XXX do we need to set the address in k_igmpsrc ?
       */
      MRTSTAT_INC(mrts_upcalls);
      if (socket_send(V_ip_mrouter, m, &k_igmpsrc) < 0) {
          log(LOG_WARNING, "bw_upcalls_send: ip_mrouter socket queue full\n");
          MRTSTAT_INC(mrts_upq_sockfull);
      }
  }
  
  /*
   * Compute the timeout hash value for the bw_meter entries
   */
  #define BW_METER_TIMEHASH(bw_meter, hash)                               \
      do {                                                                \
          struct timeval next_timeval = (bw_meter)->bm_start_time;        \
                                                                          \
          BW_TIMEVALADD(&next_timeval, &(bw_meter)->bm_threshold.b_time); \
          (hash) = next_timeval.tv_sec;                                   \
          if (next_timeval.tv_usec)                                       \
              (hash)++; /* XXX: make sure we don't timeout early */       \
          (hash) %= BW_METER_BUCKETS;                                     \
      } while (0)
  
  /*
   * Schedule a timer to process periodically bw_meter entry of type "<="
   * by linking the entry in the proper hash bucket.
   */
  static void
  schedule_bw_meter(struct bw_meter *x, struct timeval *nowp)
  {
      int time_hash;
  
      MFC_LOCK_ASSERT();
  
      if (!(x->bm_flags & BW_METER_LEQ))
          return;         /* XXX: we schedule timers only for "<=" entries */
  
      /*
       * Reset the bw_meter entry
       */
      x->bm_start_time = *nowp;
      x->bm_measured.b_packets = 0;
      x->bm_measured.b_bytes = 0;
      x->bm_flags &= ~BW_METER_UPCALL_DELIVERED;
  
      /*
       * Compute the timeout hash value and insert the entry
       */
      BW_METER_TIMEHASH(x, time_hash);
      x->bm_time_next = bw_meter_timers[time_hash];
      bw_meter_timers[time_hash] = x;
      x->bm_time_hash = time_hash;
  }
  
  /*
   * Unschedule the periodic timer that processes bw_meter entry of type "<="
   * by removing the entry from the proper hash bucket.
   */
  static void
  unschedule_bw_meter(struct bw_meter *x)
  {
      int time_hash;
      struct bw_meter *prev, *tmp;
  
      MFC_LOCK_ASSERT();
  
      if (!(x->bm_flags & BW_METER_LEQ))
          return;         /* XXX: we schedule timers only for "<=" entries */
  
      /*
       * Compute the timeout hash value and delete the entry
       */
      time_hash = x->bm_time_hash;
      if (time_hash >= BW_METER_BUCKETS)
          return;         /* Entry was not scheduled */
  
      for (prev = NULL, tmp = bw_meter_timers[time_hash];
               tmp != NULL; prev = tmp, tmp = tmp->bm_time_next)
          if (tmp == x)
              break;
  
      if (tmp == NULL)
          panic("unschedule_bw_meter: bw_meter entry not found");
  
      if (prev != NULL)
          prev->bm_time_next = x->bm_time_next;
      else
          bw_meter_timers[time_hash] = x->bm_time_next;
  
      x->bm_time_next = NULL;
      x->bm_time_hash = BW_METER_BUCKETS;
  }
  
  
  /*
   * Process all "<=" type of bw_meter that should be processed now,
   * and for each entry prepare an upcall if necessary. Each processed
   * entry is rescheduled again for the (periodic) processing.
   *
   * This is run periodically (once per second normally). On each round,
   * all the potentially matching entries are in the hash slot that we are
   * looking at.
   */
  static void
  bw_meter_process()
  {
      static uint32_t last_tv_sec;        /* last time we processed this */
  
      uint32_t loops;
      int i;
      struct timeval now, process_endtime;
  
      microtime(&now);
      if (last_tv_sec == now.tv_sec)
          return;         /* nothing to do */
  
      loops = now.tv_sec - last_tv_sec;
      last_tv_sec = now.tv_sec;
      if (loops > BW_METER_BUCKETS)
          loops = BW_METER_BUCKETS;
  
      MFC_LOCK();
      /*
       * Process all bins of bw_meter entries from the one after the last
       * processed to the current one. On entry, i points to the last bucket
       * visited, so we need to increment i at the beginning of the loop.
       */
      for (i = (now.tv_sec - loops) % BW_METER_BUCKETS; loops > 0; loops--) {
          struct bw_meter *x, *tmp_list;
  
          if (++i >= BW_METER_BUCKETS)
              i = 0;
  
          /* Disconnect the list of bw_meter entries from the bin */
          tmp_list = bw_meter_timers[i];
          bw_meter_timers[i] = NULL;
  
          /* Process the list of bw_meter entries */
          while (tmp_list != NULL) {
              x = tmp_list;
              tmp_list = tmp_list->bm_time_next;
  
              /* Test if the time interval is over */
              process_endtime = x->bm_start_time;
              BW_TIMEVALADD(&process_endtime, &x->bm_threshold.b_time);
              if (BW_TIMEVALCMP(&process_endtime, &now, >)) {
                  /* Not yet: reschedule, but don't reset */
                  int time_hash;
  
                  BW_METER_TIMEHASH(x, time_hash);
                  if (time_hash == i && process_endtime.tv_sec == now.tv_sec) {
                      /*
                       * XXX: somehow the bin processing is a bit ahead of time.
                       * Put the entry in the next bin.
                       */
                      if (++time_hash >= BW_METER_BUCKETS)
                          time_hash = 0;
                  }
                  x->bm_time_next = bw_meter_timers[time_hash];
                  bw_meter_timers[time_hash] = x;
                  x->bm_time_hash = time_hash;
  
                  continue;
              }
  
              /*
               * Test if we should deliver an upcall
               */
              if (((x->bm_flags & BW_METER_UNIT_PACKETS) &&
                   (x->bm_measured.b_packets <= x->bm_threshold.b_packets)) ||
                  ((x->bm_flags & BW_METER_UNIT_BYTES) &&
                   (x->bm_measured.b_bytes <= x->bm_threshold.b_bytes))) {
                  /* Prepare an upcall for delivery */
                  bw_meter_prepare_upcall(x, &now);
              }
  
              /*
               * Reschedule for next processing
               */
              schedule_bw_meter(x, &now);
          }
      }
  
      /* Send all upcalls that are pending delivery */
      bw_upcalls_send();
  
      MFC_UNLOCK();
  }
  
  /*
   * A periodic function for sending all upcalls that are pending delivery
   */
  static void
  expire_bw_upcalls_send(void *unused)
  {
      MFC_LOCK();
      bw_upcalls_send();
      MFC_UNLOCK();
  
      callout_reset(&bw_upcalls_ch, BW_UPCALLS_PERIOD,
          expire_bw_upcalls_send, NULL);
  }
  
  /*
   * A periodic function for periodic scanning of the multicast forwarding
   * table for processing all "<=" bw_meter entries.
   */
  static void
  expire_bw_meter_process(void *unused)
  {
      if (mrt_api_config & MRT_MFC_BW_UPCALL)
          bw_meter_process();
  
      callout_reset(&bw_meter_ch, BW_METER_PERIOD, expire_bw_meter_process, NULL);
  }
  
  /*
   * End of bandwidth monitoring code
   */
  
  /*
   * Send the packet up to the user daemon, or eventually do kernel encapsulation
   *
   */
  static int
  pim_register_send(struct ip *ip, struct vif *vifp, struct mbuf *m,
      struct mfc *rt)
  {
      struct mbuf *mb_copy, *mm;
  
      /*
       * Do not send IGMP_WHOLEPKT notifications to userland, if the
       * rendezvous point was unspecified, and we were told not to.
       */
      if (pim_squelch_wholepkt != 0 && (mrt_api_config & MRT_MFC_RP) &&
          in_nullhost(rt->mfc_rp))
          return 0;
  
      mb_copy = pim_register_prepare(ip, m);
      if (mb_copy == NULL)
          return ENOBUFS;
  
      /*
       * Send all the fragments. Note that the mbuf for each fragment
       * is freed by the sending machinery.
       */
      for (mm = mb_copy; mm; mm = mb_copy) {
          mb_copy = mm->m_nextpkt;
          mm->m_nextpkt = 0;
          mm = m_pullup(mm, sizeof(struct ip));
          if (mm != NULL) {
              ip = mtod(mm, struct ip *);
              if ((mrt_api_config & MRT_MFC_RP) && !in_nullhost(rt->mfc_rp)) {
                  pim_register_send_rp(ip, vifp, mm, rt);
              } else {
                  pim_register_send_upcall(ip, vifp, mm, rt);
              }
          }
      }
  
      return 0;
  }
  
  /*
   * Return a copy of the data packet that is ready for PIM Register
   * encapsulation.
   * XXX: Note that in the returned copy the IP header is a valid one.
   */
  static struct mbuf *
  pim_register_prepare(struct ip *ip, struct mbuf *m)
  {
      struct mbuf *mb_copy = NULL;
      int mtu;
  
      /* Take care of delayed checksums */
      if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
          in_delayed_cksum(m);
          m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
      }
  
      /*
       * Copy the old packet & pullup its IP header into the
       * new mbuf so we can modify it.
       */
      mb_copy = m_copypacket(m, M_DONTWAIT);
      if (mb_copy == NULL)
          return NULL;
      mb_copy = m_pullup(mb_copy, ip->ip_hl << 2);
      if (mb_copy == NULL)
          return NULL;
  
      /* take care of the TTL */
      ip = mtod(mb_copy, struct ip *);
      --ip->ip_ttl;
  
      /* Compute the MTU after the PIM Register encapsulation */
      mtu = 0xffff - sizeof(pim_encap_iphdr) - sizeof(pim_encap_pimhdr);
  
      if (ip->ip_len <= mtu) {
          /* Turn the IP header into a valid one */
          ip->ip_len = htons(ip->ip_len);
          ip->ip_off = htons(ip->ip_off);
          ip->ip_sum = 0;
          ip->ip_sum = in_cksum(mb_copy, ip->ip_hl << 2);
      } else {
          /* Fragment the packet */
          if (ip_fragment(ip, &mb_copy, mtu, 0, CSUM_DELAY_IP) != 0) {
              m_freem(mb_copy);
              return NULL;
          }
      }
      return mb_copy;
  }
  
  /*
   * Send an upcall with the data packet to the user-level process.
   */
  static int
  pim_register_send_upcall(struct ip *ip, struct vif *vifp,
      struct mbuf *mb_copy, struct mfc *rt)
  {
      struct mbuf *mb_first;
      int len = ntohs(ip->ip_len);
      struct igmpmsg *im;
      struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
  
      VIF_LOCK_ASSERT();
  
      /*
       * Add a new mbuf with an upcall header
       */
      MGETHDR(mb_first, M_DONTWAIT, MT_DATA);
      if (mb_first == NULL) {
          m_freem(mb_copy);
          return ENOBUFS;
      }
      mb_first->m_data += max_linkhdr;
      mb_first->m_pkthdr.len = len + sizeof(struct igmpmsg);
      mb_first->m_len = sizeof(struct igmpmsg);
      mb_first->m_next = mb_copy;
  
      /* Send message to routing daemon */
      im = mtod(mb_first, struct igmpmsg *);
      im->im_msgtype      = IGMPMSG_WHOLEPKT;
      im->im_mbz          = 0;
      im->im_vif          = vifp - viftable;
      im->im_src          = ip->ip_src;
      im->im_dst          = ip->ip_dst;
  
      k_igmpsrc.sin_addr  = ip->ip_src;
  
      MRTSTAT_INC(mrts_upcalls);
  
      if (socket_send(V_ip_mrouter, mb_first, &k_igmpsrc) < 0) {
          CTR1(KTR_IPMF, "%s: socket queue full", __func__);
          MRTSTAT_INC(mrts_upq_sockfull);
          return ENOBUFS;
      }
  
      /* Keep statistics */
      PIMSTAT_INC(pims_snd_registers_msgs);
      PIMSTAT_ADD(pims_snd_registers_bytes, len);
  
      return 0;
  }
  
  /*
   * Encapsulate the data packet in PIM Register message and send it to the RP.
   */
  static int
  pim_register_send_rp(struct ip *ip, struct vif *vifp, struct mbuf *mb_copy,
      struct mfc *rt)
  {
      struct mbuf *mb_first;
      struct ip *ip_outer;
      struct pim_encap_pimhdr *pimhdr;
      int len = ntohs(ip->ip_len);
      vifi_t vifi = rt->mfc_parent;
  
      VIF_LOCK_ASSERT();
  
      if ((vifi >= numvifs) || in_nullhost(viftable[vifi].v_lcl_addr)) {
          m_freem(mb_copy);
          return EADDRNOTAVAIL;           /* The iif vif is invalid */
      }
  
      /*
       * Add a new mbuf with the encapsulating header
       */
      MGETHDR(mb_first, M_DONTWAIT, MT_DATA);
      if (mb_first == NULL) {
          m_freem(mb_copy);
          return ENOBUFS;
      }
      mb_first->m_data += max_linkhdr;
      mb_first->m_len = sizeof(pim_encap_iphdr) + sizeof(pim_encap_pimhdr);
      mb_first->m_next = mb_copy;
  
      mb_first->m_pkthdr.len = len + mb_first->m_len;
  
      /*
       * Fill in the encapsulating IP and PIM header
       */
      ip_outer = mtod(mb_first, struct ip *);
      *ip_outer = pim_encap_iphdr;
      ip_outer->ip_id = ip_newid();
      ip_outer->ip_len = len + sizeof(pim_encap_iphdr) + sizeof(pim_encap_pimhdr);
      ip_outer->ip_src = viftable[vifi].v_lcl_addr;
      ip_outer->ip_dst = rt->mfc_rp;
      /*
       * Copy the inner header TOS to the outer header, and take care of the
       * IP_DF bit.
       */
      ip_outer->ip_tos = ip->ip_tos;
      if (ntohs(ip->ip_off) & IP_DF)
          ip_outer->ip_off |= IP_DF;
      pimhdr = (struct pim_encap_pimhdr *)((caddr_t)ip_outer
                                           + sizeof(pim_encap_iphdr));
      *pimhdr = pim_encap_pimhdr;
      /* If the iif crosses a border, set the Border-bit */
      if (rt->mfc_flags[vifi] & MRT_MFC_FLAGS_BORDER_VIF & mrt_api_config)
          pimhdr->flags |= htonl(PIM_BORDER_REGISTER);
  
      mb_first->m_data += sizeof(pim_encap_iphdr);
      pimhdr->pim.pim_cksum = in_cksum(mb_first, sizeof(pim_encap_pimhdr));
      mb_first->m_data -= sizeof(pim_encap_iphdr);
  
      send_packet(vifp, mb_first);
  
      /* Keep statistics */
      PIMSTAT_INC(pims_snd_registers_msgs);
      PIMSTAT_ADD(pims_snd_registers_bytes, len);
  
      return 0;
  }
  
  /*
   * pim_encapcheck() is called by the encap4_input() path at runtime to
   * determine if a packet is for PIM; allowing PIM to be dynamically loaded
   * into the kernel.
   */
  static int
  pim_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
  {
  
  #ifdef DIAGNOSTIC
      KASSERT(proto == IPPROTO_PIM, ("not for IPPROTO_PIM"));
  #endif
      if (proto != IPPROTO_PIM)
          return 0;       /* not for us; reject the datagram. */
  
      return 64;          /* claim the datagram. */
  }
  
  /*
   * PIM-SMv2 and PIM-DM messages processing.
   * Receives and verifies the PIM control messages, and passes them
   * up to the listening socket, using rip_input().
   * The only message with special processing is the PIM_REGISTER message
   * (used by PIM-SM): the PIM header is stripped off, and the inner packet
   * is passed to if_simloop().
   */
  void
  pim_input(struct mbuf *m, int off)
  {
      struct ip *ip = mtod(m, struct ip *);
      struct pim *pim;
      int minlen;
      int datalen = ip->ip_len;
      int ip_tos;
      int iphlen = off;
  
      /* Keep statistics */
      PIMSTAT_INC(pims_rcv_total_msgs);
      PIMSTAT_ADD(pims_rcv_total_bytes, datalen);
  
      /*
       * Validate lengths
       */
      if (datalen < PIM_MINLEN) {
          PIMSTAT_INC(pims_rcv_tooshort);
          CTR3(KTR_IPMF, "%s: short packet (%d) from %s",
              __func__, datalen, inet_ntoa(ip->ip_src));
          m_freem(m);
          return;
      }
  
      /*
       * If the packet is at least as big as a REGISTER, go agead
       * and grab the PIM REGISTER header size, to avoid another
       * possible m_pullup() later.
       *
       * PIM_MINLEN       == pimhdr + u_int32_t == 4 + 4 = 8
       * PIM_REG_MINLEN   == pimhdr + reghdr + encap_iphdr == 4 + 4 + 20 = 28
       */
      minlen = iphlen + (datalen >= PIM_REG_MINLEN ? PIM_REG_MINLEN : PIM_MINLEN);
      /*
       * Get the IP and PIM headers in contiguous memory, and
       * possibly the PIM REGISTER header.
       */
      if ((m->m_flags & M_EXT || m->m_len < minlen) &&
          (m = m_pullup(m, minlen)) == 0) {
          CTR1(KTR_IPMF, "%s: m_pullup() failed", __func__);
          return;
      }
  
      /* m_pullup() may have given us a new mbuf so reset ip. */
      ip = mtod(m, struct ip *);
      ip_tos = ip->ip_tos;
  
      /* adjust mbuf to point to the PIM header */
      m->m_data += iphlen;
      m->m_len  -= iphlen;
      pim = mtod(m, struct pim *);
  
      /*
       * Validate checksum. If PIM REGISTER, exclude the data packet.
       *
       * XXX: some older PIMv2 implementations don't make this distinction,
       * so for compatibility reason perform the checksum over part of the
       * message, and if error, then over the whole message.
       */
      if (PIM_VT_T(pim->pim_vt) == PIM_REGISTER && in_cksum(m, PIM_MINLEN) == 0) {
          /* do nothing, checksum okay */
      } else if (in_cksum(m, datalen)) {
          PIMSTAT_INC(pims_rcv_badsum);
          CTR1(KTR_IPMF, "%s: invalid checksum", __func__);
          m_freem(m);
          return;
      }
  
      /* PIM version check */
      if (PIM_VT_V(pim->pim_vt) < PIM_VERSION) {
          PIMSTAT_INC(pims_rcv_badversion);
          CTR3(KTR_IPMF, "%s: bad version %d expect %d", __func__,
              (int)PIM_VT_V(pim->pim_vt), PIM_VERSION);
          m_freem(m);
          return;
      }
  
      /* restore mbuf back to the outer IP */
      m->m_data -= iphlen;
      m->m_len  += iphlen;
  
      if (PIM_VT_T(pim->pim_vt) == PIM_REGISTER) {
          /*
           * Since this is a REGISTER, we'll make a copy of the register
           * headers ip + pim + u_int32 + encap_ip, to be passed up to the
           * routing daemon.
           */
          struct sockaddr_in dst = { sizeof(dst), AF_INET };
          struct mbuf *mcp;
          struct ip *encap_ip;
          u_int32_t *reghdr;
          struct ifnet *vifp;
  
          VIF_LOCK();
          if ((reg_vif_num >= numvifs) || (reg_vif_num == VIFI_INVALID)) {
              VIF_UNLOCK();
              CTR2(KTR_IPMF, "%s: register vif not set: %d", __func__,
                  (int)reg_vif_num);
              m_freem(m);
              return;
          }
          /* XXX need refcnt? */
          vifp = viftable[reg_vif_num].v_ifp;
          VIF_UNLOCK();
  
          /*
           * Validate length
           */
          if (datalen < PIM_REG_MINLEN) {
              PIMSTAT_INC(pims_rcv_tooshort);
              PIMSTAT_INC(pims_rcv_badregisters);
              CTR1(KTR_IPMF, "%s: register packet size too small", __func__);
              m_freem(m);
              return;
          }
  
          reghdr = (u_int32_t *)(pim + 1);
          encap_ip = (struct ip *)(reghdr + 1);
  
          CTR3(KTR_IPMF, "%s: register: encap ip src %s len %d",
              __func__, inet_ntoa(encap_ip->ip_src), ntohs(encap_ip->ip_len));
  
          /* verify the version number of the inner packet */
          if (encap_ip->ip_v != IPVERSION) {
              PIMSTAT_INC(pims_rcv_badregisters);
              CTR1(KTR_IPMF, "%s: bad encap ip version", __func__);
              m_freem(m);
              return;
          }
  
          /* verify the inner packet is destined to a mcast group */
          if (!IN_MULTICAST(ntohl(encap_ip->ip_dst.s_addr))) {
              PIMSTAT_INC(pims_rcv_badregisters);
              CTR2(KTR_IPMF, "%s: bad encap ip dest %s", __func__,
                  inet_ntoa(encap_ip->ip_dst));
              m_freem(m);
              return;
          }
  
          /* If a NULL_REGISTER, pass it to the daemon */
          if ((ntohl(*reghdr) & PIM_NULL_REGISTER))
              goto pim_input_to_daemon;
  
          /*
           * Copy the TOS from the outer IP header to the inner IP header.
           */
          if (encap_ip->ip_tos != ip_tos) {
              /* Outer TOS -> inner TOS */
              encap_ip->ip_tos = ip_tos;
              /* Recompute the inner header checksum. Sigh... */
  
              /* adjust mbuf to point to the inner IP header */
              m->m_data += (iphlen + PIM_MINLEN);
              m->m_len  -= (iphlen + PIM_MINLEN);
  
              encap_ip->ip_sum = 0;
              encap_ip->ip_sum = in_cksum(m, encap_ip->ip_hl << 2);
  
              /* restore mbuf to point back to the outer IP header */
              m->m_data -= (iphlen + PIM_MINLEN);
              m->m_len  += (iphlen + PIM_MINLEN);
          }
  
          /*
           * Decapsulate the inner IP packet and loopback to forward it
           * as a normal multicast packet. Also, make a copy of the
           *     outer_iphdr + pimhdr + reghdr + encap_iphdr
           * to pass to the daemon later, so it can take the appropriate
           * actions (e.g., send back PIM_REGISTER_STOP).
           * XXX: here m->m_data points to the outer IP header.
           */
          mcp = m_copy(m, 0, iphlen + PIM_REG_MINLEN);
          if (mcp == NULL) {
              CTR1(KTR_IPMF, "%s: m_copy() failed", __func__);
              m_freem(m);
              return;
          }
  
          /* Keep statistics */
          /* XXX: registers_bytes include only the encap. mcast pkt */
          PIMSTAT_INC(pims_rcv_registers_msgs);
          PIMSTAT_ADD(pims_rcv_registers_bytes, ntohs(encap_ip->ip_len));
  
          /*
           * forward the inner ip packet; point m_data at the inner ip.
           */
          m_adj(m, iphlen + PIM_MINLEN);
  
          CTR4(KTR_IPMF,
              "%s: forward decap'd REGISTER: src %lx dst %lx vif %d",
              __func__,
              (u_long)ntohl(encap_ip->ip_src.s_addr),
              (u_long)ntohl(encap_ip->ip_dst.s_addr),
              (int)reg_vif_num);
  
          /* NB: vifp was collected above; can it change on us? */
          if_simloop(vifp, m, dst.sin_family, 0);
  
          /* prepare the register head to send to the mrouting daemon */
          m = mcp;
      }
  
  pim_input_to_daemon:
      /*
       * 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
       * outer IP header, PIM header, PIM-Register header and the
       * inner IP header.
       * XXX: the outer IP header pkt size of a Register is not adjust to
       * reflect the fact that the inner multicast data is truncated.
       */
      rip_input(m, iphlen);
  
      return;
  }
  
  static int
  sysctl_mfctable(SYSCTL_HANDLER_ARGS)
  {
          struct mfc      *rt;
          int              error, i;
  
          if (req->newptr)
                  return (EPERM);
          if (mfchashtbl == NULL) /* XXX unlocked */
                  return (0);
          error = sysctl_wire_old_buffer(req, 0);
          if (error)
                  return (error);
  
          MFC_LOCK();
          for (i = 0; i < mfchashsize; i++) {
                  LIST_FOREACH(rt, &mfchashtbl[i], mfc_hash) {
                          error = SYSCTL_OUT(req, rt, sizeof(struct mfc));
                          if (error)
                                  goto out_locked;
                  }
          }
  out_locked:
          MFC_UNLOCK();
          return (error);
  }
  
  SYSCTL_NODE(_net_inet_ip, OID_AUTO, mfctable, CTLFLAG_RD, sysctl_mfctable,
      "IPv4 Multicast Forwarding Table (struct *mfc[mfchashsize], "
      "netinet/ip_mroute.h)");
  
  static int
  ip_mroute_modevent(module_t mod, int type, void *unused)
  {
  
      switch (type) {
      case MOD_LOAD:
          MROUTER_LOCK_INIT();
          MFC_LOCK_INIT();
          VIF_LOCK_INIT();
  
          mfchashsize = MFCHASHSIZE;
          if (TUNABLE_ULONG_FETCH("net.inet.ip.mfchashsize", &mfchashsize) &&
              !powerof2(mfchashsize)) {
                  printf("WARNING: %s not a power of 2; using default\n",
                      "net.inet.ip.mfchashsize");
                  mfchashsize = MFCHASHSIZE;
          }
          MALLOC(nexpire, u_char *, mfchashsize, M_MRTABLE, M_WAITOK|M_ZERO);
  
          pim_squelch_wholepkt = 0;
          TUNABLE_ULONG_FETCH("net.inet.pim.squelch_wholepkt",
              &pim_squelch_wholepkt);
          ip_mrouter_reset();
  
          pim_encap_cookie = encap_attach_func(AF_INET, IPPROTO_PIM,
              pim_encapcheck, &in_pim_protosw, NULL);
          if (pim_encap_cookie == NULL) {
                  printf("ip_mroute: unable to attach pim encap\n");
                  VIF_LOCK_DESTROY();
                  MFC_LOCK_DESTROY();
                  MROUTER_LOCK_DESTROY();
                  return (EINVAL);
          }
  
          ip_mcast_src = X_ip_mcast_src;
          ip_mforward = X_ip_mforward;
          ip_mrouter_done = X_ip_mrouter_done;
          ip_mrouter_get = X_ip_mrouter_get;
          ip_mrouter_set = X_ip_mrouter_set;
  
          ip_rsvp_force_done = X_ip_rsvp_force_done;
          ip_rsvp_vif = X_ip_rsvp_vif;
  
          legal_vif_num = X_legal_vif_num;
          mrt_ioctl = X_mrt_ioctl;
          rsvp_input_p = X_rsvp_input;
          break;
  
      case MOD_UNLOAD:
          /*
           * Typically module unload happens after the user-level
           * process has shutdown the kernel services (the check
           * below insures someone can't just yank the module out
           * from under a running process).  But if the module is
           * just loaded and then unloaded w/o starting up a user
           * process we still need to cleanup.
           */
          if (V_ip_mrouter != NULL)
              return (EINVAL);
  
          if (pim_encap_cookie) {
              encap_detach(pim_encap_cookie);
              pim_encap_cookie = NULL;
          }
          X_ip_mrouter_done();
  
          FREE(nexpire, M_MRTABLE);
          nexpire = NULL;
  
          ip_mcast_src = NULL;
          ip_mforward = NULL;
          ip_mrouter_done = NULL;
          ip_mrouter_get = NULL;
          ip_mrouter_set = NULL;
  
          ip_rsvp_force_done = NULL;
          ip_rsvp_vif = NULL;
  
          legal_vif_num = NULL;
          mrt_ioctl = NULL;
          rsvp_input_p = NULL;
  
          VIF_LOCK_DESTROY();
          MFC_LOCK_DESTROY();
          MROUTER_LOCK_DESTROY();
          break;
  
      default:
          return EOPNOTSUPP;
      }
      return 0;
  }
  
  static moduledata_t ip_mroutemod = {
      "ip_mroute",
      ip_mroute_modevent,
      0
  };
  
  DECLARE_MODULE(ip_mroute, ip_mroutemod, SI_SUB_PSEUDO, SI_ORDER_ANY);

Cache object: 6c119854f14846f02c343419f35792c4