IP_FORWARDING, NULL, NULL);
IP_FORWARDING, (void *)NULL, (void *)NULL);
tbf_send_packet(vifp,m)    register struct vif *vifp;    register struct mbuf *m;{    int error;    int s = splsoftnet();    if (vifp->v_flags & VIFF_TUNNEL) {	/* If tunnel options */	ip_output(m, (struct mbuf *)0, &vifp->v_route,		  IP_FORWARDING, NULL, NULL);    } else {	/* if physical interface option, extract the options and then send */	struct ip *ip = mtod(m, struct ip *);	struct ip_moptions imo;	imo.imo_multicast_ifp  = vifp->v_ifp;	imo.imo_multicast_ttl  = ip->ip_ttl - 1;	imo.imo_multicast_loop = 1;#ifdef RSVP_ISI	imo.imo_multicast_vif  = -1;#endif	error = ip_output(m, (struct mbuf *)0, (struct route *)0,			  IP_FORWARDING|IP_MULTICASTOPTS, &imo, NULL);	if (mrtdebug & DEBUG_XMIT)	    log(LOG_DEBUG, "phyint_send on vif %d err %d\n", vifp-viftable, error);    }    splx(s);}