TUN_STAYUP 175 net/if_tun.c tp->tun_flags = TUN_INITED|TUN_STAYUP; TUN_STAYUP 316 net/if_tun.c tp->tun_flags &= ~TUN_STAYUP; TUN_STAYUP 362 net/if_tun.c if (!(tp->tun_flags & TUN_STAYUP))