Function tundtor

freebsd/net/if_tuntap.c:1109–1183

* tundtor - tear down the device - mark i/f down & delete * routing info */

 * routing info
 */
static void
tundtor(void *data)
{
	struct proc *p;
	struct tuntap_softc *tp;
	struct ifnet *ifp;
	bool l2tun;

	tp = data;
	p = curproc;
	ifp = TUN2IFP(tp);

	TUN_LOCK(tp);

	/*
	 * Realistically, we can't be obstinate here.  This only means that the
	 * tuntap device was closed out of order, and the last closer wasn't the
	 * controller.  These are still good to know about, though, as software
	 * should avoid multiple processes with a tuntap device open and
	 * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
	 * parent).
	 */
	if (p->p_pid != tp->tun_pid) {
		log(LOG_INFO,
		    "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
		    p->p_pid, p->p_comm, tp->tun_dev->si_name);
	}

	/*
	 * junk all pending output
	 */
	CURVNET_SET(ifp->if_vnet);

	l2tun = false;
	if ((tp->tun_flags & TUN_L2) != 0) {
		l2tun = true;
		IF_DRAIN(&ifp->if_snd);
	} else {
		IFQ_PURGE(&ifp->if_snd);
	}

	/* For vmnet, we won't do most of the address/route bits */
	if ((tp->tun_flags & TUN_VMNET) != 0 ||
	    (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
		goto out;

	if (ifp->if_flags & IFF_UP) {
		TUN_UNLOCK(tp);
		if_down(ifp);
		TUN_LOCK(tp);
	}

	/* Delete all addresses and routes which reference this interface. */
	if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
		ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
		TUN_UNLOCK(tp);
		if_purgeaddrs(ifp);
		TUN_LOCK(tp);