1 files changed, 74 insertions, 14 deletions

diff --git a/sys/net/if_tuntap.c b/sys/net/if_tuntap.c
index 5e6f65c04b2f..c8dbb6aa8893 100644
--- a/sys/net/if_tuntap.c
+++ b/sys/net/if_tuntap.c
@@ -132,6 +132,7 @@ struct tuntap_softc {
 #define	TUN_DYING	0x0200
 #define	TUN_L2		0x0400
 #define	TUN_VMNET	0x0800
+#define	TUN_TRANSIENT	0x1000
 
 #define	TUN_DRIVER_IDENT_MASK	(TUN_L2 | TUN_VMNET)
 #define	TUN_READY		(TUN_OPEN | TUN_INITED)
@@ -443,6 +444,18 @@ tuntap_name2info(const char *name, int *outunit, int *outflags)
 	return (0);
 }
 
+static struct if_clone *
+tuntap_cloner_from_flags(int tun_flags)
+{
+
+	for (u_int i = 0; i < NDRV; i++)
+		if ((tun_flags & TUN_DRIVER_IDENT_MASK) ==
+		    tuntap_drivers[i].ident_flags)
+			return (V_tuntap_driver_cloners[i]);
+
+	return (NULL);
+}
+
 /*
  * Get driver information from a set of flags specified.  Masks the identifying
  * part of the flags and compares it against all of the available
@@ -615,19 +628,39 @@ out:
 	CURVNET_RESTORE();
 }
 
-static void
-tun_destroy(struct tuntap_softc *tp)
+static int
+tun_destroy(struct tuntap_softc *tp, bool may_intr)
 {
+	int error;
 
 	TUN_LOCK(tp);
+
+	/*
+	 * Transient tunnels may have set TUN_DYING if we're being destroyed as
+	 * a result of the last close, which we'll allow.
+	 */
+	MPASS((tp->tun_flags & (TUN_DYING | TUN_TRANSIENT)) != TUN_DYING);
 	tp->tun_flags |= TUN_DYING;
-	if (tp->tun_busy != 0)
-		cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
-	else
-		TUN_UNLOCK(tp);
+	error = 0;
+	while (tp->tun_busy != 0) {
+		if (may_intr)
+			error = cv_wait_sig(&tp->tun_cv, &tp->tun_mtx);
+		else
+			cv_wait(&tp->tun_cv, &tp->tun_mtx);
+		if (error != 0) {
+			tp->tun_flags &= ~TUN_DYING;
+			TUN_UNLOCK(tp);
+			return (error);
+		}
+	}
+	TUN_UNLOCK(tp);
 
 	CURVNET_SET(TUN2IFP(tp)->if_vnet);
 
+	mtx_lock(&tunmtx);
+	TAILQ_REMOVE(&tunhead, tp, tun_list);
+	mtx_unlock(&tunmtx);
+
 	/* destroy_dev will take care of any alias. */
 	destroy_dev(tp->tun_dev);
 	seldrain(&tp->tun_rsel);
@@ -648,6 +681,8 @@ tun_destroy(struct tuntap_softc *tp)
 	cv_destroy(&tp->tun_cv);
 	free(tp, M_TUN);
 	CURVNET_RESTORE();
+
+	return (0);
 }
 
 static int
@@ -655,12 +690,7 @@ tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp, uint32_t fla
 {
 	struct tuntap_softc *tp = ifp->if_softc;
 
-	mtx_lock(&tunmtx);
-	TAILQ_REMOVE(&tunhead, tp, tun_list);
-	mtx_unlock(&tunmtx);
-	tun_destroy(tp);
-
-	return (0);
+	return (tun_destroy(tp, true));
 }
 
 static void
@@ -702,9 +732,9 @@ tun_uninit(const void *unused __unused)
 
 	mtx_lock(&tunmtx);
 	while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
-		TAILQ_REMOVE(&tunhead, tp, tun_list);
 		mtx_unlock(&tunmtx);
-		tun_destroy(tp);
+		/* tun_destroy() will remove it from the tailq. */
+		tun_destroy(tp, false);
 		mtx_lock(&tunmtx);
 	}
 	mtx_unlock(&tunmtx);
@@ -1217,6 +1247,23 @@ out:
 	tun_vnethdr_set(ifp, 0);
 
 	tun_unbusy_locked(tp);
+	if ((tp->tun_flags & TUN_TRANSIENT) != 0) {
+		struct if_clone *cloner;
+		int error __diagused;
+
+		/* Mark it busy so that nothing can re-open it. */
+		tp->tun_flags |= TUN_DYING;
+		TUN_UNLOCK(tp);
+
+		CURVNET_SET_QUIET(ifp->if_home_vnet);
+		cloner = tuntap_cloner_from_flags(tp->tun_flags);
+		CURVNET_RESTORE();
+
+		error = if_clone_destroyif(cloner, ifp);
+		MPASS(error == 0 || error == EINTR || error == ERESTART);
+		return;
+	}
+
 	TUN_UNLOCK(tp);
 }
 
@@ -1668,6 +1715,19 @@ tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
 	case TUNGDEBUG:
 		*(int *)data = tundebug;
 		break;
+	case TUNSTRANSIENT:
+		TUN_LOCK(tp);
+		if (*(int *)data)
+			tp->tun_flags |= TUN_TRANSIENT;
+		else
+			tp->tun_flags &= ~TUN_TRANSIENT;
+		TUN_UNLOCK(tp);
+		break;
+	case TUNGTRANSIENT:
+		TUN_LOCK(tp);
+		*(int *)data = (tp->tun_flags & TUN_TRANSIENT) != 0;
+		TUN_UNLOCK(tp);
+		break;
 	case FIONBIO:
 		break;
 	case FIOASYNC: