allow the automatically created loopback interfaces in rdomains to be

deleted if the rdomain doesn't contain any other interface. turn the rdomain
back into an ordinary, empty rtable in that case.
with this and the previous commits one can get rid of rdomains again without
rebooting, which wasn't possible any more for some time
ok bluhm, input mpi

diff --git a/sys/net/if_loop.c b/sys/net/if_loop.c
index 1edd9ea..7d8c06c 100644 (file)
--- a/sys/net/if_loop.c
+++ b/sys/net/if_loop.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_loop.c,v 1.87 2018/03/02 15:52:11 claudio Exp $    */
+/*     $OpenBSD: if_loop.c,v 1.88 2018/09/09 10:11:41 henning Exp $    */
 /*     $NetBSD: if_loop.c,v 1.15 1996/05/07 02:40:33 thorpej Exp $     */
 
 /*
@@ -195,8 +195,27 @@ loop_clone_create(struct if_clone *ifc, int unit)
 int
 loop_clone_destroy(struct ifnet *ifp)
 {
-       if (ifp->if_index == rtable_loindex(ifp->if_rdomain))
-               return (EPERM);
+       struct ifnet    *p;
+
+       if (ifp->if_index == rtable_loindex(ifp->if_rdomain)) {
+               /* rdomain 0 always needs a loopback */
+               if (ifp->if_rdomain == 0)
+                       return (EPERM);
+
+               /* if there is any other interface in this rdomain, deny */
+               NET_LOCK();
+               TAILQ_FOREACH(p, &ifnet, if_list) {
+                       if (p->if_rdomain != ifp->if_rdomain)
+                               continue;
+                       if (p->if_index == ifp->if_index)
+                               continue;
+                       NET_UNLOCK();
+                       return (EBUSY);
+               }
+               NET_UNLOCK();
+
+               rtable_l2set(ifp->if_rdomain, 0, 0);
+       }
 
        if_ih_remove(ifp, loinput, NULL);
        if_detach(ifp);