actually set the link state down when the /dev entry is closed.

this means a route message is sent when the interface is closed and
goes down, but also causes another route message to be sent when
the interface comes up on the next open. this is important for
things like ospfd and the ospfd regress test because they want to
know when link comes up.

the regression was pointed out by bluhm, who also helped me isolate
the problem.

1 files changed, 5 insertions, 9 deletions

diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index aca4b98e063..f074b3394bc 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_tun.c,v 1.216 2020/01/30 21:17:59 dlg Exp $	*/
+/*	$OpenBSD: if_tun.c,v 1.217 2020/01/31 02:58:28 dlg Exp $	*/
 /*	$NetBSD: if_tun.c,v 1.24 1996/05/07 02:40:48 thorpej Exp $	*/
 
 /*
@@ -130,7 +130,7 @@ int	filt_tunread(struct knote *, long);
 int	filt_tunwrite(struct knote *, long);
 void	filt_tunrdetach(struct knote *);
 void	filt_tunwdetach(struct knote *);
-void	tun_link_state(struct tun_softc *);
+void	tun_link_state(struct tun_softc *, int);
 
 const struct filterops tunread_filtops = {
 	.f_isfd		= 1,
@@ -415,7 +415,7 @@ tun_dev_open(dev_t dev, const struct if_clone *ifc, int mode, struct proc *p)
 
 	/* automatically mark the interface running on open */
 	SET(ifp->if_flags, IFF_UP | IFF_RUNNING);
-	tun_link_state(sc);
+	tun_link_state(sc, LINK_STATE_FULL_DUPLEX);
 
 	return (0);
 }
@@ -468,7 +468,7 @@ tun_dev_close(dev_t dev, struct proc *p)
 			strlcpy(name, ifp->if_xname, sizeof(name));
 		} else {
 			CLR(ifp->if_flags, IFF_UP | IFF_RUNNING);
-			tun_link_state(sc);
+			tun_link_state(sc, LINK_STATE_DOWN);
 		}
 	}
 
@@ -1067,13 +1067,9 @@ tun_start(struct ifnet *ifp)
 }
 
 void
-tun_link_state(struct tun_softc *sc)
+tun_link_state(struct tun_softc *sc, int link_state)
 {
 	struct ifnet *ifp = &sc->sc_if;
-	int link_state = LINK_STATE_DOWN;
-
-	if (sc->sc_dev != 0)
-		link_state = LINK_STATE_FULL_DUPLEX;
 
 	if (ifp->if_link_state != link_state) {
 		ifp->if_link_state = link_state;