t_dst4
sc->sc_tunnel.t_dst4 = dst4->sin_addr;
sin->sin_addr = sc->sc_tunnel.t_dst4;
ip->ip_dst = sc->sc_tunnel.t_dst4;
key.t_dst4 = ip->ip_src;
if (in_nullhost(sc->sc_tunnel.t_dst4))
ip->ip_dst = sc->sc_tunnel.t_dst4;
sin->sin_addr = tunnel->t_dst4;
tunnel->t_dst4 = dst4->sin_addr;
key.t_dst4 = ip->ip_src;
tunnel->t_dst4.s_addr = INADDR_ANY;
tunnel->t_dst4 = dst4->sin_addr;
sin->sin_addr = tunnel->t_dst4;
inm = in_addmulti(&tunnel->t_dst4, ifp0);
tunnel->t_dst4.s_addr = INADDR_ANY;
tunnel->t_dst4 = daddr4->sin_addr;
sin->sin_addr = tunnel->t_dst4;
key.t_dst4 = ip->ip_src;