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

     /*
      * 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
     *
     * MROUTING Revision: 3.5
     * $FreeBSD: src/sys/netinet/ip_mroute.c,v 1.34.2.4 1999/09/05 08:18:33 peter Exp $
     */
    
    #include "opt_mrouting.h"
    
    #include <sys/param.h>
    #include <sys/queue.h>
    #include <sys/systm.h>
    #include <sys/mbuf.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/protosw.h>
    #include <sys/errno.h>
    #include <sys/time.h>
    #include <sys/kernel.h>
    #include <sys/ioctl.h>
    #include <sys/syslog.h>
    #include <net/if.h>
    #include <net/route.h>
    #include <netinet/in.h>
    #include <netinet/in_systm.h>
    #include <netinet/ip.h>
    #include <netinet/ip_var.h>
    #include <netinet/in_pcb.h>
    #include <netinet/in_var.h>
    #include <netinet/igmp.h>
    #include <netinet/igmp_var.h>
    #include <netinet/ip_mroute.h>
    #include <netinet/udp.h>
    
    #ifndef NTOHL
    #if BYTE_ORDER != BIG_ENDIAN
    #define NTOHL(d) ((d) = ntohl((d)))
    #define NTOHS(d) ((d) = ntohs((u_short)(d)))
    #define HTONL(d) ((d) = htonl((d)))
    #define HTONS(d) ((d) = htons((u_short)(d)))
    #else
    #define NTOHL(d)
    #define NTOHS(d)
    #define HTONL(d)
    #define HTONS(d)
    #endif
    #endif
    
    #ifndef MROUTING
    extern u_long   _ip_mcast_src __P((int vifi));
    extern int      _ip_mforward __P((struct ip *ip, struct ifnet *ifp,
                                      struct mbuf *m, struct ip_moptions *imo));
    extern int      _ip_mrouter_done __P((void));
    extern int      _ip_mrouter_get __P((int cmd, struct socket *so,
                                         struct mbuf **m));
    extern int      _ip_mrouter_set __P((int cmd, struct socket *so,
                                         struct mbuf *m));
    extern int      _mrt_ioctl __P((int req, caddr_t data, struct proc *p));
    
    /*
     * Dummy routines and globals used when multicast routing is not compiled in.
     */
    
    struct socket  *ip_mrouter  = NULL;
    static u_int            ip_mrtproto = 0;
    static struct mrtstat   mrtstat;
    u_int           rsvpdebug = 0;
    
    int
    _ip_mrouter_set(cmd, so, m)
            int cmd;
            struct socket *so;
            struct mbuf *m;
    {
            return(EOPNOTSUPP);
    }
    
    int (*ip_mrouter_set)(int, struct socket *, struct mbuf *) = _ip_mrouter_set;
    
    
    int
    _ip_mrouter_get(cmd, so, m)
            int cmd;
            struct socket *so;
            struct mbuf **m;
    {
            return(EOPNOTSUPP);
    }
    
    int (*ip_mrouter_get)(int, struct socket *, struct mbuf **) = _ip_mrouter_get;
    
    int
   _ip_mrouter_done()
   {
           return(0);
   }
   
   int (*ip_mrouter_done)(void) = _ip_mrouter_done;
   
   int
   _ip_mforward(ip, ifp, m, imo)
           struct ip *ip;
           struct ifnet *ifp;
           struct mbuf *m;
           struct ip_moptions *imo;
   {
           return(0);
   }
   
   int (*ip_mforward)(struct ip *, struct ifnet *, struct mbuf *,
                      struct ip_moptions *) = _ip_mforward;
   
   int
   _mrt_ioctl(int req, caddr_t data, struct proc *p)
   {
           return EOPNOTSUPP;
   }
   
   int (*mrt_ioctl)(int, caddr_t, struct proc *) = _mrt_ioctl;
   
   void
   rsvp_input(m, iphlen)           /* XXX must fixup manually */
           struct mbuf *m;
           int iphlen;
   {
       /* Can still get packets with rsvp_on = 0 if there is a local member
        * of the group to which the RSVP packet is addressed.  But in this
        * case we want to throw the packet away.
        */
       if (!rsvp_on) {
           m_freem(m);
           return;
       }
    
       if (ip_rsvpd != NULL) {
           if (rsvpdebug)
               printf("rsvp_input: Sending packet up old-style socket\n");
           rip_input(m, iphlen);
           return;
       }
       /* Drop the packet */
       m_freem(m);
   }
   
   void ipip_input(struct mbuf *m, int iphlen) { /* XXX must fixup manually */
           rip_input(m, iphlen);
   }
   
   int (*legal_vif_num)(int) = 0;
   
   /*
    * This should never be called, since IP_MULTICAST_VIF should fail, but
    * just in case it does get called, the code a little lower in ip_output
    * will assign the packet a local address.
    */
   u_long
   _ip_mcast_src(int vifi) { return INADDR_ANY; }
   u_long (*ip_mcast_src)(int) = _ip_mcast_src;
   
   int
   ip_rsvp_vif_init(so, m)
       struct socket *so;
       struct mbuf *m;
   {
       return(EINVAL);
   }
   
   int
   ip_rsvp_vif_done(so, m)
       struct socket *so;
       struct mbuf *m;
   {
       return(EINVAL);
   }
   
   void
   ip_rsvp_force_done(so)
       struct socket *so;
   {
       return;
   }
   
   #else /* MROUTING */
   
   #define M_HASCL(m)      ((m)->m_flags & M_EXT)
   
   #define INSIZ           sizeof(struct in_addr)
   #define same(a1, a2) \
           (bcmp((caddr_t)(a1), (caddr_t)(a2), INSIZ) == 0)
   
   #define MT_MRTABLE MT_RTABLE    /* since nothing else uses it */
   
   /*
    * Globals.  All but ip_mrouter and ip_mrtproto could be static,
    * except for netstat or debugging purposes.
    */
   #ifndef MROUTE_LKM
   struct socket  *ip_mrouter  = NULL;
   struct mrtstat  mrtstat;
   
   int             ip_mrtproto = IGMP_DVMRP;    /* for netstat only */
   #else /* MROUTE_LKM */
   extern void     X_ipip_input __P((struct mbuf *m, int iphlen));
   extern struct mrtstat mrtstat;
   static int ip_mrtproto;
   #endif
   
   #define NO_RTE_FOUND    0x1
   #define RTE_FOUND       0x2
   
   static struct mbuf    *mfctable[MFCTBLSIZ];
   static u_char           nexpire[MFCTBLSIZ];
   static struct vif       viftable[MAXVIFS];
   static u_int    mrtdebug = 0;     /* debug level        */
   #define         DEBUG_MFC       0x02
   #define         DEBUG_FORWARD   0x04
   #define         DEBUG_EXPIRE    0x08
   #define         DEBUG_XMIT      0x10
   static u_int    tbfdebug = 0;     /* tbf debug level    */
   static u_int    rsvpdebug = 0;    /* rsvp debug level   */
   
   #define         EXPIRE_TIMEOUT  (hz / 4)        /* 4x / second          */
   #define         UPCALL_EXPIRE   6               /* number of timeouts   */
   
   /*
    * Define the token bucket filter structures
    * tbftable -> each vif has one of these for storing info 
    */
   
   static struct tbf tbftable[MAXVIFS];
   #define         TBF_REPROCESS   (hz / 100)      /* 100x / second */
   
   /*
    * 'Interfaces' associated with decapsulator (so we can tell
    * packets that went through it from ones that get reflected
    * by a broken gateway).  These interfaces are never linked into
    * the system ifnet list & no routes point to them.  I.e., packets
    * can't be sent this way.  They only exist as a placeholder for
    * multicast source verification.
    */
   static struct ifnet multicast_decap_if[MAXVIFS];
   
   #define ENCAP_TTL 64
   #define ENCAP_PROTO IPPROTO_IPIP        /* 4 */
   
   /* prototype IP hdr for encapsulated packets */
   static struct ip multicast_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 */
           ENCAP_TTL, ENCAP_PROTO, 
           0,                              /* checksum */
   };
   
   /*
    * Private variables.
    */
   static vifi_t      numvifs = 0;
   static int have_encap_tunnel = 0;
   
   /*
    * one-back cache used by ipip_input to locate a tunnel's vif
    * given a datagram's src ip address.
    */
   static u_long last_encap_src;
   static struct vif *last_encap_vif;
   
   static u_long   X_ip_mcast_src __P((int vifi));
   static int      X_ip_mforward __P((struct ip *ip, struct ifnet *ifp, struct mbuf *m, struct ip_moptions *imo));
   static int      X_ip_mrouter_done __P((void));
   static int      X_ip_mrouter_get __P((int cmd, struct socket *so, struct mbuf **m));
   static int      X_ip_mrouter_set __P((int cmd, struct socket *so, struct mbuf *m));
   static int      X_legal_vif_num __P((int vif));
   static int      X_mrt_ioctl __P((int cmd, caddr_t data));
   
   static int get_sg_cnt(struct sioc_sg_req *);
   static int get_vif_cnt(struct sioc_vif_req *);
   static int ip_mrouter_init(struct socket *, struct mbuf *);
   static int add_vif(struct vifctl *);
   static int del_vif(vifi_t *);
   static int add_mfc(struct mfcctl *);
   static int del_mfc(struct mfcctl *);
   static int socket_send(struct socket *, struct mbuf *, struct sockaddr_in *);
   static int get_version(struct mbuf *);
   static int get_assert(struct mbuf *);
   static int set_assert(int *);
   static void expire_upcalls(void *);
   static int ip_mdq(struct mbuf *, struct ifnet *, struct mfc *,
                     vifi_t);
   static void phyint_send(struct ip *, struct vif *, struct mbuf *);
   static void encap_send(struct ip *, struct vif *, struct mbuf *);
   static void tbf_control(struct vif *, struct mbuf *, struct ip *, u_long);
   static void tbf_queue(struct vif *, struct mbuf *);
   static void tbf_process_q(struct vif *);
   static void tbf_reprocess_q(void *);
   static int tbf_dq_sel(struct vif *, struct ip *);
   static void tbf_send_packet(struct vif *, struct mbuf *);
   static void tbf_update_tokens(struct vif *);
   static int priority(struct vif *, struct ip *);
   void multiencap_decap(struct mbuf *);
   
   /*
    * whether or not special PIM assert processing is enabled.
    */
   static int pim_assert;
   /*
    * Rate limit for assert notification messages, in usec
    */
   #define ASSERT_MSG_TIME         3000000
   
   /*
    * Hash function for a source, group entry
    */
   #define MFCHASH(a, g) MFCHASHMOD(((a) >> 20) ^ ((a) >> 10) ^ (a) ^ \
                           ((g) >> 20) ^ ((g) >> 10) ^ (g))
   
   /*
    * Find a route for a given origin IP address and Multicast group address
    * Type of service parameter to be added in the future!!!
    */
   
   #define MFCFIND(o, g, rt) { \
           register struct mbuf *_mb_rt = mfctable[MFCHASH(o,g)]; \
           register struct mfc *_rt = NULL; \
           rt = NULL; \
           ++mrtstat.mrts_mfc_lookups; \
           while (_mb_rt) { \
                   _rt = mtod(_mb_rt, struct mfc *); \
                   if ((_rt->mfc_origin.s_addr == o) && \
                       (_rt->mfc_mcastgrp.s_addr == g) && \
                       (_mb_rt->m_act == NULL)) { \
                           rt = _rt; \
                           break; \
                   } \
                   _mb_rt = _mb_rt->m_next; \
           } \
           if (rt == NULL) { \
                   ++mrtstat.mrts_mfc_misses; \
           } \
   }
   
   
   /*
    * Macros to compute elapsed time efficiently
    * Borrowed from Van Jacobson's scheduling code
    */
   #define TV_DELTA(a, b, delta) { \
               register int xxs; \
                   \
               delta = (a).tv_usec - (b).tv_usec; \
               if ((xxs = (a).tv_sec - (b).tv_sec)) { \
                  switch (xxs) { \
                         case 2: \
                             delta += 1000000; \
                                 /* fall through */ \
                         case 1: \
                             delta += 1000000; \
                             break; \
                         default: \
                             delta += (1000000 * xxs); \
                  } \
               } \
   }
   
   #define TV_LT(a, b) (((a).tv_usec < (b).tv_usec && \
                 (a).tv_sec <= (b).tv_sec) || (a).tv_sec < (b).tv_sec)
   
   #ifdef UPCALL_TIMING
   u_long upcall_data[51];
   static void collate(struct timeval *);
   #endif /* UPCALL_TIMING */
   
   
   /*
    * Handle MRT setsockopt commands to modify the multicast routing tables.
    */
   static int
   X_ip_mrouter_set(cmd, so, m)
       int cmd;
       struct socket *so;
       struct mbuf *m;
   {
      if (cmd != MRT_INIT && so != ip_mrouter) return EACCES;
   
       switch (cmd) {
           case MRT_INIT:     return ip_mrouter_init(so, m);
           case MRT_DONE:     return ip_mrouter_done();
           case MRT_ADD_VIF:  return add_vif (mtod(m, struct vifctl *));
           case MRT_DEL_VIF:  return del_vif (mtod(m, vifi_t *));
           case MRT_ADD_MFC:  return add_mfc (mtod(m, struct mfcctl *));
           case MRT_DEL_MFC:  return del_mfc (mtod(m, struct mfcctl *));
           case MRT_ASSERT:   return set_assert(mtod(m, int *));
           default:             return EOPNOTSUPP;
       }
   }
   
   #ifndef MROUTE_LKM
   int (*ip_mrouter_set)(int, struct socket *, struct mbuf *) = X_ip_mrouter_set;
   #endif
   
   /*
    * Handle MRT getsockopt commands
    */
   static int
   X_ip_mrouter_get(cmd, so, m)
       int cmd;
       struct socket *so;
       struct mbuf **m;
   {
       struct mbuf *mb;
   
       if (so != ip_mrouter) return EACCES;
   
       *m = mb = m_get(M_WAIT, MT_SOOPTS);
     
       switch (cmd) {
           case MRT_VERSION:   return get_version(mb);
           case MRT_ASSERT:    return get_assert(mb);
           default:            return EOPNOTSUPP;
       }
   }
   
   #ifndef MROUTE_LKM
   int (*ip_mrouter_get)(int, struct socket *, struct mbuf **) = X_ip_mrouter_get;
   #endif
   
   /*
    * Handle ioctl commands to obtain information from the cache
    */
   static int
   X_mrt_ioctl(cmd, data)
       int cmd;
       caddr_t data;
   {
       int error = 0;
   
       switch (cmd) {
           case (SIOCGETVIFCNT):
               return (get_vif_cnt((struct sioc_vif_req *)data));
               break;
           case (SIOCGETSGCNT):
               return (get_sg_cnt((struct sioc_sg_req *)data));
               break;
           default:
               return (EINVAL);
               break;
       }
       return error;
   }
   
   #ifndef MROUTE_LKM
   int (*mrt_ioctl)(int, caddr_t) = X_mrt_ioctl;
   #endif
   
   /*
    * returns the packet, byte, rpf-failure count for the source group provided
    */
   static int
   get_sg_cnt(req)
       register struct sioc_sg_req *req;
   {
       register struct mfc *rt;
       int s;
   
       s = splnet();
       MFCFIND(req->src.s_addr, req->grp.s_addr, rt);
       splx(s);
       if (rt != NULL) {
           req->pktcnt = rt->mfc_pkt_cnt;
           req->bytecnt = rt->mfc_byte_cnt;
           req->wrong_if = rt->mfc_wrong_if;
       } else
           req->pktcnt = req->bytecnt = req->wrong_if = 0xffffffff;
   
       return 0;
   }
   
   /*
    * returns the input and output packet and byte counts on the vif provided
    */
   static int
   get_vif_cnt(req)
       register struct sioc_vif_req *req;
   {
       register vifi_t vifi = req->vifi;
   
       if (vifi >= numvifs) 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;
   
       return 0;
   }
   
   /*
    * Enable multicast routing
    */
   static int
   ip_mrouter_init(so, m)
           struct socket *so;
           struct mbuf *m;
   {
       int *v;
   
       if (mrtdebug)
           log(LOG_DEBUG,"ip_mrouter_init: so_type = %d, pr_protocol = %d\n",
                   so->so_type, so->so_proto->pr_protocol);
   
       if (so->so_type != SOCK_RAW ||
           so->so_proto->pr_protocol != IPPROTO_IGMP) return EOPNOTSUPP;
   
       if (!m || (m->m_len != sizeof(int *)))
           return ENOPROTOOPT;
   
       v = mtod(m, int *);
       if (*v != 1)
           return ENOPROTOOPT;
   
       if (ip_mrouter != NULL) return EADDRINUSE;
   
       ip_mrouter = so;
   
       bzero((caddr_t)mfctable, sizeof(mfctable));
       bzero((caddr_t)nexpire, sizeof(nexpire));
   
       pim_assert = 0;
   
       timeout(expire_upcalls, (caddr_t)NULL, EXPIRE_TIMEOUT);
   
       if (mrtdebug)
           log(LOG_DEBUG, "ip_mrouter_init\n");
   
       return 0;
   }
   
   /*
    * Disable multicast routing
    */
   static int
   X_ip_mrouter_done()
   {
       vifi_t vifi;
       int i;
       struct ifnet *ifp;
       struct ifreq ifr;
       struct mbuf *mb_rt;
       struct mbuf *m;
       struct rtdetq *rte;
       int s;
   
       s = splnet();
   
       /*
        * For each phyint in use, disable promiscuous reception of all IP
        * multicasts.
        */
       for (vifi = 0; vifi < numvifs; vifi++) {
           if (viftable[vifi].v_lcl_addr.s_addr != 0 &&
               !(viftable[vifi].v_flags & VIFF_TUNNEL)) {
               ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET;
               ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr.s_addr
                                                                   = INADDR_ANY;
               ifp = viftable[vifi].v_ifp;
               (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)&ifr);
           }
       }
       bzero((caddr_t)tbftable, sizeof(tbftable));
       bzero((caddr_t)viftable, sizeof(viftable));
       numvifs = 0;
       pim_assert = 0;
   
       untimeout(expire_upcalls, (caddr_t)NULL);
   
       /*
        * Free all multicast forwarding cache entries.
        */
       for (i = 0; i < MFCTBLSIZ; i++) {
           mb_rt = mfctable[i];
           while (mb_rt) {
               if (mb_rt->m_act != NULL) {
                   while (mb_rt->m_act) {
                       m = mb_rt->m_act;
                       mb_rt->m_act = m->m_act;
                       rte = mtod(m, struct rtdetq *);
                       m_freem(rte->m);
                       m_free(m);
                   }
               }
               mb_rt = m_free(mb_rt);
           }
       }
   
       bzero((caddr_t)mfctable, sizeof(mfctable));
   
       /*
        * Reset de-encapsulation cache
        */
       last_encap_src = 0;
       last_encap_vif = NULL;
       have_encap_tunnel = 0;
    
       ip_mrouter = NULL;
   
       splx(s);
   
       if (mrtdebug)
           log(LOG_DEBUG, "ip_mrouter_done\n");
   
       return 0;
   }
   
   #ifndef MROUTE_LKM
   int (*ip_mrouter_done)(void) = X_ip_mrouter_done;
   #endif
   
   static int
   get_version(mb)
       struct mbuf *mb;
   {
       int *v;
   
       v = mtod(mb, int *);
   
       *v = 0x0305;        /* XXX !!!! */
       mb->m_len = sizeof(int);
   
       return 0;
   }
   
   /*
    * Set PIM assert processing global
    */
   static int
   set_assert(i)
       int *i;
   {
       if ((*i != 1) && (*i != 0))
           return EINVAL;
   
       pim_assert = *i;
   
       return 0;
   }
   
   /*
    * Get PIM assert processing global
    */
   static int
   get_assert(m)
       struct mbuf *m;
   {
       int *i;
   
       i = mtod(m, int *);
   
       *i = pim_assert;
   
       return 0;
   }
   
   /*
    * Add a vif to the vif table
    */
   static int
   add_vif(vifcp)
       register struct vifctl *vifcp;
   {
       register struct vif *vifp = viftable + vifcp->vifc_vifi;
       static struct sockaddr_in sin = {sizeof sin, AF_INET};
       struct ifaddr *ifa;
       struct ifnet *ifp;
       struct ifreq ifr;
       int error, s;
       struct tbf *v_tbf = tbftable + vifcp->vifc_vifi;
   
       if (vifcp->vifc_vifi >= MAXVIFS)  return EINVAL;
       if (vifp->v_lcl_addr.s_addr != 0) return EADDRINUSE;
   
       /* Find the interface with an address in AF_INET family */
       sin.sin_addr = vifcp->vifc_lcl_addr;
       ifa = ifa_ifwithaddr((struct sockaddr *)&sin);
       if (ifa == 0) return EADDRNOTAVAIL;
       ifp = ifa->ifa_ifp;
   
       if (vifcp->vifc_flags & VIFF_TUNNEL) {
           if ((vifcp->vifc_flags & VIFF_SRCRT) == 0) {
                   /*
                    * An encapsulating tunnel is wanted.  Tell ipip_input() to
                    * start paying attention to encapsulated packets.
                    */
                   if (have_encap_tunnel == 0) {
                           have_encap_tunnel = 1;
                           for (s = 0; s < MAXVIFS; ++s) {
                                   multicast_decap_if[s].if_name = "mdecap";
                                   multicast_decap_if[s].if_unit = s;
                           }
                   }
                   /*
                    * Set interface to fake encapsulator interface
                    */
                   ifp = &multicast_decap_if[vifcp->vifc_vifi];
                   /*
                    * Prepare cached route entry
                    */
                   bzero(&vifp->v_route, sizeof(vifp->v_route));
           } else {
               log(LOG_ERR, "source routed tunnels not supported\n");
               return EOPNOTSUPP;
           }
       } else {
           /* Make sure the interface supports multicast */
           if ((ifp->if_flags & IFF_MULTICAST) == 0)
               return EOPNOTSUPP;
   
           /* Enable promiscuous reception of all IP multicasts from the if */
           ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET;
           ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr.s_addr = INADDR_ANY;
           s = splnet();
           error = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, (caddr_t)&ifr);
           splx(s);
           if (error)
               return error;
       }
   
       s = splnet();
       /* define parameters for the tbf structure */
       vifp->v_tbf = v_tbf;
       GET_TIME(vifp->v_tbf->tbf_last_pkt_t);
       vifp->v_tbf->tbf_n_tok = 0;
       vifp->v_tbf->tbf_q_len = 0;
       vifp->v_tbf->tbf_max_q_len = MAXQSIZE;
       vifp->v_tbf->tbf_q = vifp->v_tbf->tbf_t = NULL;
   
       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;
       /* scaling up here allows division by 1024 in critical code */
       vifp->v_rate_limit= vifcp->vifc_rate_limit * 1024 / 1000;
       vifp->v_rsvp_on   = 0;
       vifp->v_rsvpd     = NULL;
       /* 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;
       splx(s);
   
       /* Adjust numvifs up if the vifi is higher than numvifs */
       if (numvifs <= vifcp->vifc_vifi) numvifs = vifcp->vifc_vifi + 1;
   
       if (mrtdebug)
           log(LOG_DEBUG, "add_vif #%d, lcladdr %x, %s %x, thresh %x, rate %d\n",
               vifcp->vifc_vifi, 
               ntohl(vifcp->vifc_lcl_addr.s_addr),
               (vifcp->vifc_flags & VIFF_TUNNEL) ? "rmtaddr" : "mask",
               ntohl(vifcp->vifc_rmt_addr.s_addr),
               vifcp->vifc_threshold,
               vifcp->vifc_rate_limit);    
   
       return 0;
   }
   
   /*
    * Delete a vif from the vif table
    */
   static int
   del_vif(vifip)
       vifi_t *vifip;
   {
       register struct vif *vifp = viftable + *vifip;
       register vifi_t vifi;
       register struct mbuf *m;
       struct ifnet *ifp;
       struct ifreq ifr;
       int s;
   
       if (*vifip >= numvifs) return EINVAL;
       if (vifp->v_lcl_addr.s_addr == 0) return EADDRNOTAVAIL;
   
       s = splnet();
   
       if (!(vifp->v_flags & VIFF_TUNNEL)) {
           ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET;
           ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr.s_addr = INADDR_ANY;
           ifp = vifp->v_ifp;
           (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)&ifr);
       }
   
       if (vifp == last_encap_vif) {
           last_encap_vif = 0;
           last_encap_src = 0;
       }
   
       /*
        * Free packets queued at the interface
        */
       while (vifp->v_tbf->tbf_q) {
           m = vifp->v_tbf->tbf_q;
           vifp->v_tbf->tbf_q = m->m_act;
           m_freem(m);
       }
   
       bzero((caddr_t)vifp->v_tbf, sizeof(*(vifp->v_tbf)));
       bzero((caddr_t)vifp, sizeof (*vifp));
   
       /* Adjust numvifs down */
       for (vifi = numvifs; vifi > 0; vifi--)
           if (viftable[vifi-1].v_lcl_addr.s_addr != 0) break;
       numvifs = vifi;
   
       splx(s);
   
       if (mrtdebug)
         log(LOG_DEBUG, "del_vif %d, numvifs %d\n", *vifip, numvifs);
   
       return 0;
   }
   
   /*
    * Add an mfc entry
    */
   static int
   add_mfc(mfccp)
       struct mfcctl *mfccp;
   {
       struct mfc *rt;
       register struct mbuf *mb_rt;
       u_long hash;
       struct mbuf *mb_ntry;
       struct rtdetq *rte;
       register u_short nstl;
       int s;
       int i;
   
       MFCFIND(mfccp->mfcc_origin.s_addr, mfccp->mfcc_mcastgrp.s_addr, rt);
   
       /* If an entry already exists, just update the fields */
       if (rt) {
           if (mrtdebug & DEBUG_MFC)
               log(LOG_DEBUG,"add_mfc update o %x g %x p %x\n",
                   ntohl(mfccp->mfcc_origin.s_addr),
                   ntohl(mfccp->mfcc_mcastgrp.s_addr),
                   mfccp->mfcc_parent);
   
           s = splnet();
           rt->mfc_parent = mfccp->mfcc_parent;
           for (i = 0; i < numvifs; i++)
               rt->mfc_ttls[i] = mfccp->mfcc_ttls[i];
           splx(s);
           return 0;
       }
   
       /* 
        * Find the entry for which the upcall was made and update
        */
       s = splnet();
       hash = MFCHASH(mfccp->mfcc_origin.s_addr, mfccp->mfcc_mcastgrp.s_addr);
       for (mb_rt = mfctable[hash], nstl = 0; mb_rt; mb_rt = mb_rt->m_next) {
   
           rt = mtod(mb_rt, struct mfc *);
           if ((rt->mfc_origin.s_addr == mfccp->mfcc_origin.s_addr) &&
               (rt->mfc_mcastgrp.s_addr == mfccp->mfcc_mcastgrp.s_addr) &&
               (mb_rt->m_act != NULL)) {
     
               if (nstl++)
                   log(LOG_ERR, "add_mfc %s o %x g %x p %x dbx %x\n",
                       "multiple kernel entries",
                       ntohl(mfccp->mfcc_origin.s_addr),
                       ntohl(mfccp->mfcc_mcastgrp.s_addr),
                       mfccp->mfcc_parent, mb_rt->m_act);
   
               if (mrtdebug & DEBUG_MFC)
                   log(LOG_DEBUG,"add_mfc o %x g %x p %x dbg %x\n",
                       ntohl(mfccp->mfcc_origin.s_addr),
                       ntohl(mfccp->mfcc_mcastgrp.s_addr),
                       mfccp->mfcc_parent, mb_rt->m_act);
   
               rt->mfc_origin     = mfccp->mfcc_origin;
               rt->mfc_mcastgrp   = mfccp->mfcc_mcastgrp;
               rt->mfc_parent     = mfccp->mfcc_parent;
               for (i = 0; i < numvifs; i++)
                   rt->mfc_ttls[i] = mfccp->mfcc_ttls[i];
               /* initialize pkt counters per src-grp */
               rt->mfc_pkt_cnt    = 0;
               rt->mfc_byte_cnt   = 0;
               rt->mfc_wrong_if   = 0;
               rt->mfc_last_assert.tv_sec = rt->mfc_last_assert.tv_usec = 0;
   
               rt->mfc_expire = 0; /* Don't clean this guy up */
               nexpire[hash]--;
   
               /* free packets Qed at the end of this entry */
               while (mb_rt->m_act) {
                   mb_ntry = mb_rt->m_act;
                   rte = mtod(mb_ntry, struct rtdetq *);
   /* #ifdef RSVP_ISI */
                   ip_mdq(rte->m, rte->ifp, rt, -1);
   /* #endif */
                   mb_rt->m_act = mb_ntry->m_act;
                   m_freem(rte->m);
   #ifdef UPCALL_TIMING
                   collate(&(rte->t));
   #endif /* UPCALL_TIMING */
                   m_free(mb_ntry);
               }
           }
       }
   
       /*
        * It is possible that an entry is being inserted without an upcall
        */
       if (nstl == 0) {
           if (mrtdebug & DEBUG_MFC)
               log(LOG_DEBUG,"add_mfc no upcall h %d o %x g %x p %x\n",
                   hash, ntohl(mfccp->mfcc_origin.s_addr),
                   ntohl(mfccp->mfcc_mcastgrp.s_addr),
                   mfccp->mfcc_parent);
           
           for (mb_rt = mfctable[hash]; mb_rt; mb_rt = mb_rt->m_next) {
               
               rt = mtod(mb_rt, struct mfc *);
               if ((rt->mfc_origin.s_addr == mfccp->mfcc_origin.s_addr) &&
                   (rt->mfc_mcastgrp.s_addr == mfccp->mfcc_mcastgrp.s_addr)) {
   
                   rt->mfc_origin     = mfccp->mfcc_origin;
                   rt->mfc_mcastgrp   = mfccp->mfcc_mcastgrp;
                   rt->mfc_parent     = mfccp->mfcc_parent;
                   for (i = 0; i < numvifs; i++)
                       rt->mfc_ttls[i] = mfccp->mfcc_ttls[i];
                   /* initialize pkt counters per src-grp */
                   rt->mfc_pkt_cnt    = 0;
                   rt->mfc_byte_cnt   = 0;
                   rt->mfc_wrong_if   = 0;
                   rt->mfc_last_assert.tv_sec = rt->mfc_last_assert.tv_usec = 0;
                   if (rt->mfc_expire)
                       nexpire[hash]--;
                   rt->mfc_expire     = 0;
               }
           }
           if (mb_rt == NULL) {
               /* no upcall, so make a new entry */
               MGET(mb_rt, M_DONTWAIT, MT_MRTABLE);
               if (mb_rt == NULL) {
                   splx(s);
                   return ENOBUFS;
               }
               
               rt = mtod(mb_rt, struct mfc *);
               
               /* insert new entry at head of hash chain */
               rt->mfc_origin     = mfccp->mfcc_origin;
               rt->mfc_mcastgrp   = mfccp->mfcc_mcastgrp;
               rt->mfc_parent     = mfccp->mfcc_parent;
               for (i = 0; i < numvifs; i++)
                       rt->mfc_ttls[i] = mfccp->mfcc_ttls[i];
               /* initialize pkt counters per src-grp */
               rt->mfc_pkt_cnt    = 0;
               rt->mfc_byte_cnt   = 0;
               rt->mfc_wrong_if   = 0;
               rt->mfc_last_assert.tv_sec = rt->mfc_last_assert.tv_usec = 0;
               rt->mfc_expire     = 0;
               
               /* link into table */
               mb_rt->m_next  = mfctable[hash];
               mfctable[hash] = mb_rt;
               mb_rt->m_act = NULL;
           }
       }
       splx(s);
       return 0;
   }
   
   #ifdef UPCALL_TIMING
   /*
    * collect delay statistics on the upcalls 
    */
   static void collate(t)
   register struct timeval *t;
   {
       register u_long d;
       register struct timeval tp;
       register u_long delta;
      
      GET_TIME(tp);
      
      if (TV_LT(*t, tp))
      {
          TV_DELTA(tp, *t, delta);
          
          d = delta >> 10;
          if (d > 50)
              d = 50;
          
          ++upcall_data[d];
      }
  }
  #endif /* UPCALL_TIMING */
  
  /*
   * Delete an mfc entry
   */
  static int
  del_mfc(mfccp)
      struct mfcctl *mfccp;
  {
      struct in_addr      origin;
      struct in_addr      mcastgrp;
      struct mfc          *rt;
      struct mbuf         *mb_rt;
      struct mbuf         **nptr;
      u_long              hash;
      int s;
  
      origin = mfccp->mfcc_origin;
      mcastgrp = mfccp->mfcc_mcastgrp;
      hash = MFCHASH(origin.s_addr, mcastgrp.s_addr);
  
      if (mrtdebug & DEBUG_MFC)
          log(LOG_DEBUG,"del_mfc orig %x mcastgrp %x\n",
              ntohl(origin.s_addr), ntohl(mcastgrp.s_addr));
  
      s = splnet();
  
      nptr = &mfctable[hash];
      while ((mb_rt = *nptr) != NULL) {
          rt = mtod(mb_rt, struct mfc *);
          if (origin.s_addr == rt->mfc_origin.s_addr &&
              mcastgrp.s_addr == rt->mfc_mcastgrp.s_addr &&
              mb_rt->m_act == NULL)
              break;
  
          nptr = &mb_rt->m_next;
      }
      if (mb_rt == NULL) {
          splx(s);
          return EADDRNOTAVAIL;
      }
  
      MFREE(mb_rt, *nptr);
  
      splx(s);
  
      return 0;
  }
  
  /*
   * Send a message to mrouted on the multicast routing socket
   */
  static int
  socket_send(s, mm, src)
          struct socket *s;
          struct mbuf *mm;
          struct sockaddr_in *src;
  {
          if (s) {
                  if (sbappendaddr(&s->so_rcv,
                                   (struct sockaddr *)src,
                                   mm, (struct mbuf *)0) != 0) {
                          sorwakeup(s);
                          return 0;
                  }
          }
          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 IP_HDR_LEN  20  /* # bytes of fixed IP header (excluding options) */
  #define TUNNEL_LEN  12  /* # bytes of IP option for tunnel encapsulation  */
  
  static int
  X_ip_mforward(ip, ifp, m, imo)
      register struct ip *ip;
      struct ifnet *ifp;
      struct mbuf *m;
      struct ip_moptions *imo;
  {
      register struct mfc *rt;
      register u_char *ipoptions;
      static struct sockaddr_in   k_igmpsrc       = { sizeof k_igmpsrc, AF_INET };
      static int srctun = 0;
      register struct mbuf *mm;
      int s;
      vifi_t vifi;
      struct vif *vifp;
  
      if (mrtdebug & DEBUG_FORWARD)
          log(LOG_DEBUG, "ip_mforward: src %x, dst %x, ifp %x\n",
              ntohl(ip->ip_src.s_addr), ntohl(ip->ip_dst.s_addr), ifp);
  
      if (ip->ip_hl < (IP_HDR_LEN + TUNNEL_LEN) >> 2 ||
          (ipoptions = (u_char *)(ip + 1))[1] != IPOPT_LSRR ) {
          /*
           * Packet arrived via a physical interface or
           * an encapsulated tunnel.
           */
      } else {
          /*
           * Packet arrived through a source-route tunnel.
           * Source-route tunnels are no longer supported.
           */
          if ((srctun++ % 1000) == 0)
              log(LOG_ERR, "ip_mforward: received source-routed packet from %x\n",
                  ntohl(ip->ip_src.s_addr));
  
          return 1;
      }
  
      if ((imo) && ((vifi = imo->imo_multicast_vif) < numvifs)) {
          if (ip->ip_ttl < 255)
                  ip->ip_ttl++;   /* compensate for -1 in *_send routines */
          if (rsvpdebug && ip->ip_p == IPPROTO_RSVP) {
              vifp = viftable + vifi;
              printf("Sending IPPROTO_RSVP from %lx to %lx on vif %d (%s%s%d)\n",
                  ntohl(ip->ip_src.s_addr), ntohl(ip->ip_dst.s_addr), vifi,
                  (vifp->v_flags & VIFF_TUNNEL) ? "tunnel on " : "",
                  vifp->v_ifp->if_name, vifp->v_ifp->if_unit);
          }
          return (ip_mdq(m, ifp, NULL, vifi));
      }
      if (rsvpdebug && ip->ip_p == IPPROTO_RSVP) {
          printf("Warning: IPPROTO_RSVP from %lx to %lx without vif option\n",
              ntohl(ip->ip_src.s_addr), ntohl(ip->ip_dst.s_addr));
          if(!imo)
                  printf("In fact, no options were specified at all\n");
      }
  
      /*
       * 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 ||
          ntohl(ip->ip_dst.s_addr) <= INADDR_MAX_LOCAL_GROUP)
          return 0;
  
      /*
       * Determine forwarding vifs from the forwarding cache table
       */
      s = splnet();
      MFCFIND(ip->ip_src.s_addr, ip->ip_dst.s_addr, rt);
  
      /* Entry exists, so forward if necessary */
      if (rt != NULL) {
          splx(s);
          return (ip_mdq(m, ifp, rt, -1));
      } else {
          /*
           * If we don't have a route for packet's origin,
           * Make a copy of the packet &
           * send message to routing daemon
           */
  
          register struct mbuf *mb_rt;
          register struct mbuf *mb_ntry;
          register struct mbuf *mb0;
          register struct rtdetq *rte;
          register struct mbuf *rte_m;
          register u_long hash;
          register int npkts;
          int hlen = ip->ip_hl << 2;
  #ifdef UPCALL_TIMING
          struct timeval tp;
  
          GET_TIME(tp);
  #endif
  
          mrtstat.mrts_no_route++;
          if (mrtdebug & (DEBUG_FORWARD | DEBUG_MFC))
              log(LOG_DEBUG, "ip_mforward: no rte s %x g %x\n",
                  ntohl(ip->ip_src.s_addr),
                  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.
           */
          MGET(mb_ntry, M_DONTWAIT, MT_DATA);
          if (mb_ntry == NULL) {
              splx(s);
              return ENOBUFS;
          }
          mb0 = m_copy(m, 0, M_COPYALL);
          if (mb0 && (M_HASCL(mb0) || mb0->m_len < hlen))
              mb0 = m_pullup(mb0, hlen);
          if (mb0 == NULL) {
              m_free(mb_ntry);
              splx(s);
              return ENOBUFS;
          }
  
          /* is there an upcall waiting for this packet? */
          hash = MFCHASH(ip->ip_src.s_addr, ip->ip_dst.s_addr);
          for (mb_rt = mfctable[hash]; mb_rt; mb_rt = mb_rt->m_next) {
              rt = mtod(mb_rt, struct mfc *);
              if ((ip->ip_src.s_addr == rt->mfc_origin.s_addr) &&
                  (ip->ip_dst.s_addr == rt->mfc_mcastgrp.s_addr) &&
                  (mb_rt->m_act != NULL))
                  break;
          }
  
          if (mb_rt == NULL) {
              int i;
              struct igmpmsg *im;
  
              /* no upcall, so make a new entry */
              MGET(mb_rt, M_DONTWAIT, MT_MRTABLE);
              if (mb_rt == NULL) {
                  m_free(mb_ntry);
                  m_freem(mb0);
                  splx(s);
                  return ENOBUFS;
              }
              /* Make a copy of the header to send to the user level process */
              mm = m_copy(mb0, 0, hlen);
              if (mm == NULL) {
                  m_free(mb_ntry);
                  m_freem(mb0);
                  m_free(mb_rt);
                  splx(s);
                  return ENOBUFS;
              }
  
              /* 
               * Send message to routing daemon to install 
               * a route into the kernel table
               */
              k_igmpsrc.sin_addr = ip->ip_src;
              
              im = mtod(mm, struct igmpmsg *);
              im->im_msgtype      = IGMPMSG_NOCACHE;
              im->im_mbz          = 0;
  
              mrtstat.mrts_upcalls++;
  
              if (socket_send(ip_mrouter, mm, &k_igmpsrc) < 0) {
                  log(LOG_WARNING, "ip_mforward: ip_mrouter socket queue full\n");
                  ++mrtstat.mrts_upq_sockfull;
                  m_free(mb_ntry);
                  m_freem(mb0);
                  m_free(mb_rt);
                  splx(s);
                  return ENOBUFS;
              }
  
              rt = mtod(mb_rt, struct mfc *);
  
              /* 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_parent = -1;
  
              /* link into table */
              mb_rt->m_next  = mfctable[hash];
              mfctable[hash] = mb_rt;
              mb_rt->m_act = NULL;
  
              rte_m = mb_rt;
          } else {
              /* determine if q has overflowed */
              for (rte_m = mb_rt, npkts = 0; rte_m->m_act; rte_m = rte_m->m_act)
                  npkts++;
  
              if (npkts > MAX_UPQ) {
                  mrtstat.mrts_upq_ovflw++;
                  m_free(mb_ntry);
                  m_freem(mb0);
                  splx(s);
                  return 0;
              }
          }
  
          mb_ntry->m_act = NULL;
          rte = mtod(mb_ntry, struct rtdetq *);
  
          rte->m                  = mb0;
          rte->ifp                = ifp;
  #ifdef UPCALL_TIMING
          rte->t                  = tp;
  #endif
  
          /* Add this entry to the end of the queue */
          rte_m->m_act            = mb_ntry;
  
          splx(s);
  
          return 0;
      }           
  }
  
  #ifndef MROUTE_LKM
  int (*ip_mforward)(struct ip *, struct ifnet *, struct mbuf *,
                     struct ip_moptions *) = X_ip_mforward;
  #endif
  
  /*
   * Clean up the cache entry if upcall is not serviced
   */
  static void
  expire_upcalls(void *unused)
  {
      struct mbuf *mb_rt, *m, **nptr;
      struct rtdetq *rte;
      struct mfc *mfc;
      int i;
      int s;
  
      s = splnet();
      for (i = 0; i < MFCTBLSIZ; i++) {
          if (nexpire[i] == 0)
              continue;
          nptr = &mfctable[i];
          for (mb_rt = *nptr; mb_rt != NULL; mb_rt = *nptr) {
              mfc = mtod(mb_rt, struct mfc *);
  
              /*
               * Skip real cache entries
               * Make sure it wasn't marked to not expire (shouldn't happen)
               * If it expires now
               */
              if (mb_rt->m_act != NULL &&
                  mfc->mfc_expire != 0 &&
                  --mfc->mfc_expire == 0) {
                  if (mrtdebug & DEBUG_EXPIRE)
                      log(LOG_DEBUG, "expire_upcalls: expiring (%x %x)\n",
                          ntohl(mfc->mfc_origin.s_addr),
                          ntohl(mfc->mfc_mcastgrp.s_addr));
                  /*
                   * drop all the packets
                   * free the mbuf with the pkt, if, timing info
                   */
                  while (mb_rt->m_act) {
                      m = mb_rt->m_act;
                      mb_rt->m_act = m->m_act;
               
                      rte = mtod(m, struct rtdetq *);
                      m_freem(rte->m);
                      m_free(m);
                  }
                  ++mrtstat.mrts_cache_cleanups;
                  nexpire[i]--;
  
                  MFREE(mb_rt, *nptr);
              } else {
                  nptr = &mb_rt->m_next;
              }
          }
      }
      splx(s);
      timeout(expire_upcalls, (caddr_t)NULL, EXPIRE_TIMEOUT);
  }
  
  /*
   * Packet forwarding routine once entry in the cache is made
   */
  static int
  ip_mdq(m, ifp, rt, xmt_vif)
      register struct mbuf *m;
      register struct ifnet *ifp;
      register struct mfc *rt;
      register vifi_t xmt_vif;
  {
      register struct ip  *ip = mtod(m, struct ip *);
      register vifi_t vifi;
      register struct vif *vifp;
      register int plen = ip->ip_len;
  
  /*
   * Macro to send packet on vif.  Since RSVP packets don't get counted on
   * input, they shouldn't get counted on output, so statistics keeping is
   * seperate.
   */
  #define MC_SEND(ip,vifp,m) {                             \
                  if ((vifp)->v_flags & VIFF_TUNNEL)       \
                      encap_send((ip), (vifp), (m));       \
                  else                                     \
                      phyint_send((ip), (vifp), (m));      \
  }
  
      /*
       * 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) {
          MC_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)) {
          /* came in the wrong interface */
          if (mrtdebug & DEBUG_FORWARD)
              log(LOG_DEBUG, "wrong if: ifp %x vifi %d vififp %x\n",
                  ifp, vifi, viftable[vifi].v_ifp); 
          ++mrtstat.mrts_wrong_if;
          ++rt->mfc_wrong_if;
          /*
           * If we are doing PIM assert processing, and we are forwarding
           * packets on this interface, and it is a broadcast medium
           * interface (and not a tunnel), send a message to the routing daemon.
           */
          if (pim_assert && rt->mfc_ttls[vifi] &&
                  (ifp->if_flags & IFF_BROADCAST) &&
                  !(viftable[vifi].v_flags & VIFF_TUNNEL)) {
              struct sockaddr_in k_igmpsrc;
              struct mbuf *mm;
              struct igmpmsg *im;
              int hlen = ip->ip_hl << 2;
              struct timeval now;
              register u_long delta;
  
              GET_TIME(now);
  
              TV_DELTA(rt->mfc_last_assert, now, delta);
  
              if (delta > ASSERT_MSG_TIME) {
                  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;
                  }
  
                  rt->mfc_last_assert = now;
  
                  im = mtod(mm, struct igmpmsg *);
                  im->im_msgtype  = IGMPMSG_WRONGVIF;
                  im->im_mbz              = 0;
                  im->im_vif              = vifi;
  
                  k_igmpsrc.sin_addr = im->im_src;
  
                  socket_send(ip_mrouter, mm, &k_igmpsrc);
              }
          }
          return 0;
      }
  
      /* If I sourced this packet, it counts as output, else it was input. */
      if (ip->ip_src.s_addr == viftable[vifi].v_lcl_addr.s_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 (vifp = viftable, vifi = 0; vifi < numvifs; vifp++, vifi++)
          if ((rt->mfc_ttls[vifi] > 0) &&
              (ip->ip_ttl > rt->mfc_ttls[vifi])) {
              vifp->v_pkt_out++;
              vifp->v_bytes_out += plen;
              MC_SEND(ip, vifp, m);
          }
  
      return 0;
  }
  
  /*
   * check if a vif number is legal/ok. This is used by ip_output, to export
   * numvifs there, 
   */
  static int
  X_legal_vif_num(vif)
      int vif;
  {
      if (vif >= 0 && vif < numvifs)
         return(1);
      else
         return(0);
  }
  
  #ifndef MROUTE_LKM
  int (*legal_vif_num)(int) = X_legal_vif_num;
  #endif
  
  /*
   * Return the local address used by this vif
   */
  static u_long
  X_ip_mcast_src(vifi)
      int vifi;
  {
      if (vifi >= 0 && vifi < numvifs)
          return viftable[vifi].v_lcl_addr.s_addr;
      else
          return INADDR_ANY;
  }
  
  #ifndef MROUTE_LKM
  u_long (*ip_mcast_src)(int) = X_ip_mcast_src;
  #endif
  
  static void
  phyint_send(ip, vifp, m)
      struct ip *ip;
      struct vif *vifp;
      struct mbuf *m;
  {
      register struct mbuf *mb_copy;
      register int hlen = ip->ip_hl << 2;
  
      /*
       * 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_copy(m, 0, M_COPYALL);
      if (mb_copy && (M_HASCL(mb_copy) || mb_copy->m_len < hlen))
          mb_copy = m_pullup(mb_copy, hlen);
      if (mb_copy == NULL)
          return;
  
      if (vifp->v_rate_limit <= 0)
          tbf_send_packet(vifp, mb_copy);
      else
          tbf_control(vifp, mb_copy, mtod(mb_copy, struct ip *), ip->ip_len);
  }
  
  static void
  encap_send(ip, vifp, m)
      register struct ip *ip;
      register struct vif *vifp;
      register struct mbuf *m;
  {
      register struct mbuf *mb_copy;
      register struct ip *ip_copy;
      register int i, len = ip->ip_len;
  
      /*
       * copy the old packet & pullup it's IP header into the
       * new mbuf so we can modify it.  Try to fill the new
       * mbuf since if we don't the ethernet driver will.
       */
      MGETHDR(mb_copy, M_DONTWAIT, MT_HEADER);
      if (mb_copy == NULL)
          return;
      mb_copy->m_data += max_linkhdr;
      mb_copy->m_len = sizeof(multicast_encap_iphdr);
  
      if ((mb_copy->m_next = m_copy(m, 0, M_COPYALL)) == NULL) {
          m_freem(mb_copy);
          return;
      }
      i = MHLEN - M_LEADINGSPACE(mb_copy);
      if (i > len)
          i = len;
      mb_copy = m_pullup(mb_copy, i);
      if (mb_copy == NULL)
          return;
      mb_copy->m_pkthdr.len = len + sizeof(multicast_encap_iphdr);
  
      /*
       * fill in the encapsulating IP header.
       */
      ip_copy = mtod(mb_copy, struct ip *);
      *ip_copy = multicast_encap_iphdr;
      ip_copy->ip_id = htons(ip_id++);
      ip_copy->ip_len += len;
      ip_copy->ip_src = vifp->v_lcl_addr;
      ip_copy->ip_dst = vifp->v_rmt_addr;
  
      /*
       * turn the encapsulated IP header back into a valid one.
       */
      ip = (struct ip *)((caddr_t)ip_copy + sizeof(multicast_encap_iphdr));
      --ip->ip_ttl;
      HTONS(ip->ip_len);
      HTONS(ip->ip_off);
      ip->ip_sum = 0;
      mb_copy->m_data += sizeof(multicast_encap_iphdr);
      ip->ip_sum = in_cksum(mb_copy, ip->ip_hl << 2);
      mb_copy->m_data -= sizeof(multicast_encap_iphdr);
  
      if (vifp->v_rate_limit <= 0)
          tbf_send_packet(vifp, mb_copy);
      else
          tbf_control(vifp, mb_copy, ip, ip_copy->ip_len);
  }
  
  /*
   * De-encapsulate a packet and feed it back through ip input (this
   * routine is called whenever IP gets a packet with proto type
   * ENCAP_PROTO and a local destination address).
   */
  void
  #ifdef MROUTE_LKM
  X_ipip_input(m, iphlen)
  #else
  ipip_input(m, iphlen)
  #endif
          register struct mbuf *m;
          int iphlen;
  {
      struct ifnet *ifp = m->m_pkthdr.rcvif;
      register struct ip *ip = mtod(m, struct ip *);
      register int hlen = ip->ip_hl << 2;
      register int s;
      register struct ifqueue *ifq;
      register struct vif *vifp;
  
      if (!have_encap_tunnel) {
              rip_input(m, iphlen);
              return;
      }
      /*
       * dump the packet if it's not to a multicast destination or if
       * we don't have an encapsulating tunnel with the source.
       * Note:  This code assumes that the remote site IP address
       * uniquely identifies the tunnel (i.e., that this site has
       * at most one tunnel with the remote site).
       */
      if (! IN_MULTICAST(ntohl(((struct ip *)((char *)ip + hlen))->ip_dst.s_addr))) {
          ++mrtstat.mrts_bad_tunnel;
          m_freem(m);
          return;
      }
      if (ip->ip_src.s_addr != last_encap_src) {
          register struct vif *vife;
          
          vifp = viftable;
          vife = vifp + numvifs;
          last_encap_src = ip->ip_src.s_addr;
          last_encap_vif = 0;
          for ( ; vifp < vife; ++vifp)
              if (vifp->v_rmt_addr.s_addr == ip->ip_src.s_addr) {
                  if ((vifp->v_flags & (VIFF_TUNNEL|VIFF_SRCRT))
                      == VIFF_TUNNEL)
                      last_encap_vif = vifp;
                  break;
              }
      }
      if ((vifp = last_encap_vif) == 0) {
          last_encap_src = 0;
          mrtstat.mrts_cant_tunnel++; /*XXX*/
          m_freem(m);
          if (mrtdebug)
            log(LOG_DEBUG, "ip_mforward: no tunnel with %x\n",
                  ntohl(ip->ip_src.s_addr));
          return;
      }
      ifp = vifp->v_ifp;
  
      if (hlen > IP_HDR_LEN)
        ip_stripoptions(m, (struct mbuf *) 0);
      m->m_data += IP_HDR_LEN;
      m->m_len -= IP_HDR_LEN;
      m->m_pkthdr.len -= IP_HDR_LEN;
      m->m_pkthdr.rcvif = ifp;
  
      ifq = &ipintrq;
      s = splimp();
      if (IF_QFULL(ifq)) {
          IF_DROP(ifq);
          m_freem(m);
      } else {
          IF_ENQUEUE(ifq, m);
          /*
           * normally we would need a "schednetisr(NETISR_IP)"
           * here but we were called by ip_input and it is going
           * to loop back & try to dequeue the packet we just
           * queued as soon as we return so we avoid the
           * unnecessary software interrrupt.
           */
      }
      splx(s);
  }
  
  /*
   * Token bucket filter module
   */
  
  static void
  tbf_control(vifp, m, ip, p_len)
          register struct vif *vifp;
          register struct mbuf *m;
          register struct ip *ip;
          register u_long p_len;
  {
      register struct tbf *t = vifp->v_tbf;
  
      if (p_len > MAX_BKT_SIZE) {
          /* drop if packet is too large */
          mrtstat.mrts_pkt2large++;
          m_freem(m);
          return;
      }
  
      tbf_update_tokens(vifp);
  
      /* if there are enough tokens, 
       * and the queue is empty,
       * send this packet out
       */
  
      if (t->tbf_q_len == 0) {
          /* queue empty, send packet if enough tokens */
          if (p_len <= t->tbf_n_tok) {
              t->tbf_n_tok -= p_len;
              tbf_send_packet(vifp, m);
          } else {
              /* queue packet and timeout till later */
              tbf_queue(vifp, m);
              timeout(tbf_reprocess_q, (caddr_t)vifp, TBF_REPROCESS);
          }
      } else if (t->tbf_q_len < t->tbf_max_q_len) {
          /* finite queue length, so queue pkts and process queue */
          tbf_queue(vifp, m);
          tbf_process_q(vifp);
      } else {
          /* queue length too much, try to dq and queue and process */
          if (!tbf_dq_sel(vifp, ip)) {
              mrtstat.mrts_q_overflow++;
              m_freem(m);
              return;
          } else {
              tbf_queue(vifp, m);
              tbf_process_q(vifp);
          }
      }
      return;
  }
  
  /* 
   * adds a packet to the queue at the interface
   */
  static void
  tbf_queue(vifp, m) 
          register struct vif *vifp;
          register struct mbuf *m;
  {
      register int s = splnet();
      register struct tbf *t = vifp->v_tbf;
  
      if (t->tbf_t == NULL) {
          /* Queue was empty */
          t->tbf_q = m;
      } else {
          /* Insert at tail */
          t->tbf_t->m_act = m;
      }
  
      /* Set new tail pointer */
      t->tbf_t = m;
  
  #ifdef DIAGNOSTIC
      /* Make sure we didn't get fed a bogus mbuf */
      if (m->m_act)
          panic("tbf_queue: m_act");
  #endif
      m->m_act = NULL;
  
      t->tbf_q_len++;
  
      splx(s);
  }
  
  
  /* 
   * processes the queue at the interface
   */
  static void
  tbf_process_q(vifp)
      register struct vif *vifp;
  {
      register struct mbuf *m;
      register int len;
      register int s = splnet();
      register struct tbf *t = vifp->v_tbf;
  
      /* loop through the queue at the interface and send as many packets
       * as possible
       */
      while (t->tbf_q_len > 0) {
          m = t->tbf_q;
  
          len = mtod(m, struct ip *)->ip_len;
  
          /* determine if the packet can be sent */
          if (len <= t->tbf_n_tok) {
              /* if so,
               * reduce no of tokens, dequeue the packet,
               * send the packet.
               */
              t->tbf_n_tok -= len;
  
              t->tbf_q = m->m_act;
              if (--t->tbf_q_len == 0)
                  t->tbf_t = NULL;
  
              m->m_act = NULL;
              tbf_send_packet(vifp, m);
  
          } else break;
      }
      splx(s);
  }
  
  static void
  tbf_reprocess_q(xvifp)
          void *xvifp;
  {
      register struct vif *vifp = xvifp;
      if (ip_mrouter == NULL) 
          return;
  
      tbf_update_tokens(vifp);
  
      tbf_process_q(vifp);
  
      if (vifp->v_tbf->tbf_q_len)
          timeout(tbf_reprocess_q, (caddr_t)vifp, TBF_REPROCESS);
  }
  
  /* function that will selectively discard a member of the queue
   * based on the precedence value and the priority
   */
  static int
  tbf_dq_sel(vifp, ip)
      register struct vif *vifp;
      register struct ip *ip;
  {
      register int s = splnet();
      register u_int p;
      register struct mbuf *m, *last;
      register struct mbuf **np;
      register struct tbf *t = vifp->v_tbf;
  
      p = priority(vifp, ip);
  
      np = &t->tbf_q;
      last = NULL;
      while ((m = *np) != NULL) {
          if (p > priority(vifp, mtod(m, struct ip *))) {
              *np = m->m_act;
              /* If we're removing the last packet, fix the tail pointer */
              if (m == t->tbf_t)
                  t->tbf_t = last;
              m_freem(m);
              /* it's impossible for the queue to be empty, but
               * we check anyway. */
              if (--t->tbf_q_len == 0)
                  t->tbf_t = NULL;
              splx(s);
              mrtstat.mrts_drop_sel++;
              return(1);
          }
          np = &m->m_act;
          last = m;
      }
      splx(s);
      return(0);
  }
  
  static void
  tbf_send_packet(vifp, m)
      register struct vif *vifp;
      register struct mbuf *m;
  {
      struct ip_moptions imo;
      int error;
      static struct route ro;
      int s = splnet();
  
      if (vifp->v_flags & VIFF_TUNNEL) {
          /* If tunnel options */
          ip_output(m, (struct mbuf *)0, &vifp->v_route,
                    IP_FORWARDING, (struct ip_moptions *)0);
      } else {
          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;
  
          /*
           * 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, (struct mbuf *)0, &ro,
                            IP_FORWARDING, &imo);
  
          if (mrtdebug & DEBUG_XMIT)
              log(LOG_DEBUG, "phyint_send on vif %d err %d\n", 
                  vifp - viftable, error);
      }
      splx(s);
  }
  
  /* determine the current time and then
   * the elapsed time (between the last time and time now)
   * in milliseconds & update the no. of tokens in the bucket
   */
  static void
  tbf_update_tokens(vifp)
      register struct vif *vifp;
  {
      struct timeval tp;
      register u_long tm;
      register int s = splnet();
      register struct tbf *t = vifp->v_tbf;
  
      GET_TIME(tp);
  
      TV_DELTA(tp, t->tbf_last_pkt_t, tm);
  
      /*
       * This formula is actually
       * "time in seconds" * "bytes/second".
       *
       * (tm / 1000000) * (v_rate_limit * 1000 * (1000/1024) / 8)
       *
       * The (1000/1024) was introduced in add_vif to optimize
       * this divide into a shift.
       */
      t->tbf_n_tok += tm * vifp->v_rate_limit / 1024 / 8;
      t->tbf_last_pkt_t = tp;
  
      if (t->tbf_n_tok > MAX_BKT_SIZE)
          t->tbf_n_tok = MAX_BKT_SIZE;
  
      splx(s);
  }
  
  static int
  priority(vifp, ip)
      register struct vif *vifp;
      register struct ip *ip;
  {
      register int prio;
  
      /* temporary hack; may add general packet classifier some day */
  
      /*
       * The UDP port space is divided up into four priority ranges:
       * [0, 16384)     : unclassified - lowest priority
       * [16384, 32768) : audio - highest priority
       * [32768, 49152) : whiteboard - medium priority
       * [49152, 65536) : video - low priority
       */
      if (ip->ip_p == IPPROTO_UDP) {
          struct udphdr *udp = (struct udphdr *)(((char *)ip) + (ip->ip_hl << 2));
          switch (ntohs(udp->uh_dport) & 0xc000) {
              case 0x4000:
                  prio = 70;
                  break;
              case 0x8000:
                  prio = 60;
                  break;
              case 0xc000:
                  prio = 55;
                  break;
              default:
                  prio = 50;
                  break;
          }
          if (tbfdebug > 1)
                  log(LOG_DEBUG, "port %x prio%d\n", ntohs(udp->uh_dport), prio);
      } else {
              prio = 50;
      }
      return prio;
  }
  
  /*
   * End of token bucket filter modifications 
   */
  
  int
  ip_rsvp_vif_init(so, m)
      struct socket *so;
      struct mbuf *m;
  {
      int i;
      register int s;
  
      if (rsvpdebug)
          printf("ip_rsvp_vif_init: so_type = %d, pr_protocol = %d\n",
                 so->so_type, so->so_proto->pr_protocol);
  
      if (so->so_type != SOCK_RAW || so->so_proto->pr_protocol != IPPROTO_RSVP)
          return EOPNOTSUPP;
  
      /* Check mbuf. */
      if (m == NULL || m->m_len != sizeof(int)) {
          return EINVAL;
      }
      i = *(mtod(m, int *));
   
      if (rsvpdebug)
          printf("ip_rsvp_vif_init: vif = %d rsvp_on = %d\n",i,rsvp_on);
   
      s = splnet();
  
      /* Check vif. */
      if (!legal_vif_num(i)) {
          splx(s);
          return EADDRNOTAVAIL;
      }
  
      /* Check if socket is available. */
      if (viftable[i].v_rsvpd != NULL) {
          splx(s);
          return EADDRINUSE;
      }
  
      viftable[i].v_rsvpd = so;
      /* This may seem silly, but we need to be sure we don't over-increment
       * the RSVP counter, in case something slips up.
       */
      if (!viftable[i].v_rsvp_on) {
          viftable[i].v_rsvp_on = 1;
          rsvp_on++;
      }
  
      splx(s);
      return 0;
  }
  
  int
  ip_rsvp_vif_done(so, m)
      struct socket *so;
      struct mbuf *m;
  {
          int i;
          register int s;
   
      if (rsvpdebug)
          printf("ip_rsvp_vif_done: so_type = %d, pr_protocol = %d\n",
                 so->so_type, so->so_proto->pr_protocol);
   
      if (so->so_type != SOCK_RAW || so->so_proto->pr_protocol != IPPROTO_RSVP)
          return EOPNOTSUPP;
   
      /* Check mbuf. */
      if (m == NULL || m->m_len != sizeof(int)) {
              return EINVAL;
      }
      i = *(mtod(m, int *));
   
      s = splnet();
   
      /* Check vif. */
      if (!legal_vif_num(i)) {
          splx(s);
          return EADDRNOTAVAIL;
      }
  
      if (rsvpdebug)
          printf("ip_rsvp_vif_done: v_rsvpd = %p so = %p\n",
                 viftable[i].v_rsvpd, so);
  
      viftable[i].v_rsvpd = NULL;
      /* This may seem silly, but we need to be sure we don't over-decrement
       * the RSVP counter, in case something slips up.
       */
      if (viftable[i].v_rsvp_on) {
          viftable[i].v_rsvp_on = 0;
          rsvp_on--;
      }
  
      splx(s);
      return 0;
  }
  
  void
  ip_rsvp_force_done(so)
      struct socket *so;
  {
      int vifi;
      register int s;
  
      /* Don't bother if it is not the right type of socket. */
      if (so->so_type != SOCK_RAW || so->so_proto->pr_protocol != IPPROTO_RSVP)
          return;
  
      s = splnet();
  
      /* The socket may be attached to more than one vif...this
       * is perfectly legal.
       */
      for (vifi = 0; vifi < numvifs; vifi++) {
          if (viftable[vifi].v_rsvpd == so) {
              viftable[vifi].v_rsvpd = NULL;
              /* This may seem silly, but we need to be sure we don't
               * over-decrement the RSVP counter, in case something slips up.
               */
              if (viftable[vifi].v_rsvp_on) {
                  viftable[vifi].v_rsvp_on = 0;
                  rsvp_on--;
              }
          }
      }
  
      splx(s);
      return;
  }
  
  void
  rsvp_input(m, iphlen)
          struct mbuf *m;
          int iphlen;
  {
      int vifi;
      register struct ip *ip = mtod(m, struct ip *);
      static struct sockaddr_in rsvp_src = { sizeof rsvp_src, AF_INET };
      register int s;
      struct ifnet *ifp;
  
      if (rsvpdebug)
          printf("rsvp_input: rsvp_on %d\n",rsvp_on);
  
      /* Can still get packets with rsvp_on = 0 if there is a local member
       * of the group to which the RSVP packet is addressed.  But in this
       * case we want to throw the packet away.
       */
      if (!rsvp_on) {
          m_freem(m);
          return;
      }
  
      /* If the old-style non-vif-associated socket is set, then use
       * it and ignore the new ones.
       */
      if (ip_rsvpd != NULL) {
          if (rsvpdebug)
              printf("rsvp_input: Sending packet up old-style socket\n");
          rip_input(m, iphlen);
          return;
      }
  
      s = splnet();
  
      if (rsvpdebug)
          printf("rsvp_input: check vifs\n");
  
  #ifdef DIAGNOSTIC
      if (!(m->m_flags & M_PKTHDR))
              panic("rsvp_input no hdr");
  #endif
  
      ifp = m->m_pkthdr.rcvif;
      /* Find which vif the packet arrived on. */
      for (vifi = 0; vifi < numvifs; vifi++) {
          if (viftable[vifi].v_ifp == ifp)
                  break;
          }
   
      if (vifi == numvifs) {
          /* Can't find vif packet arrived on. Drop packet. */
          if (rsvpdebug)
              printf("rsvp_input: Can't find vif for packet...dropping it.\n");
          m_freem(m);
          splx(s);
          return;
      }
  
      if (rsvpdebug)
          printf("rsvp_input: check socket\n");
  
      if (viftable[vifi].v_rsvpd == NULL) {
          /* drop packet, since there is no specific socket for this
           * interface */
              if (rsvpdebug)
                      printf("rsvp_input: No socket defined for vif %d\n",vifi);
              m_freem(m);
              splx(s);
              return;
      }
      rsvp_src.sin_addr = ip->ip_src;
  
      if (rsvpdebug && m)
          printf("rsvp_input: m->m_len = %d, sbspace() = %ld\n",
                 m->m_len,sbspace(&(viftable[vifi].v_rsvpd->so_rcv)));
  
      if (socket_send(viftable[vifi].v_rsvpd, m, &rsvp_src) < 0)
          if (rsvpdebug)
              printf("rsvp_input: Failed to append to socket\n");
      else
          if (rsvpdebug)
              printf("rsvp_input: send packet up\n");
      
      splx(s);
  }
  
  #ifdef MROUTE_LKM
  #include <sys/conf.h>
  #include <sys/exec.h>
  #include <sys/sysent.h>
  #include <sys/lkm.h>
  
  MOD_MISC("ip_mroute_mod")
  
  static int
  ip_mroute_mod_handle(struct lkm_table *lkmtp, int cmd)
  {
          int i;
          struct lkm_misc *args = lkmtp->private.lkm_misc;
          int err = 0;
  
          switch(cmd) {
                  static int (*old_ip_mrouter_cmd)();
                  static int (*old_ip_mrouter_done)();
                  static int (*old_ip_mforward)();
                  static int (*old_mrt_ioctl)();
                  static void (*old_proto4_input)();
                  static int (*old_legal_vif_num)();
                  extern struct protosw inetsw[];
  
          case LKM_E_LOAD:
                  if(lkmexists(lkmtp) || ip_mrtproto)
                    return(EEXIST);
                  old_ip_mrouter_cmd = ip_mrouter_cmd;
                  ip_mrouter_cmd = X_ip_mrouter_cmd;
                  old_ip_mrouter_done = ip_mrouter_done;
                  ip_mrouter_done = X_ip_mrouter_done;
                  old_ip_mforward = ip_mforward;
                  ip_mforward = X_ip_mforward;
                  old_mrt_ioctl = mrt_ioctl;
                  mrt_ioctl = X_mrt_ioctl;
                old_proto4_input = inetsw[ip_protox[ENCAP_PROTO]].pr_input;
                inetsw[ip_protox[ENCAP_PROTO]].pr_input = X_ipip_input;
                  old_legal_vif_num = legal_vif_num;
                  legal_vif_num = X_legal_vif_num;
                  ip_mrtproto = IGMP_DVMRP;
  
                  printf("\nIP multicast routing loaded\n");
                  break;
  
          case LKM_E_UNLOAD:
                  if (ip_mrouter)
                    return EINVAL;
  
                  ip_mrouter_cmd = old_ip_mrouter_cmd;
                  ip_mrouter_done = old_ip_mrouter_done;
                  ip_mforward = old_ip_mforward;
                  mrt_ioctl = old_mrt_ioctl;
                inetsw[ip_protox[ENCAP_PROTO]].pr_input = old_proto4_input;
                  legal_vif_num = old_legal_vif_num;
                  ip_mrtproto = 0;
                  break;
  
          default:
                  err = EINVAL;
                  break;
          }
  
          return(err);
  }
  
  int
  ip_mroute_mod(struct lkm_table *lkmtp, int cmd, int ver) {
          DISPATCH(lkmtp, cmd, ver, ip_mroute_mod_handle, ip_mroute_mod_handle,
                   nosys);
  }
  
  #endif /* MROUTE_LKM */
  #endif /* MROUTING */

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