Currently, attempting to move an immovable lo(4) to a new rdomain will fail

with an EPERM, but the target rdomain will still be created.

Move the check for an lo(4)'s if_index/if_rdomain to before the creation of a
nonexisting target routing table.

ok benno@ claudio@ mpi@

diff --git a/sys/net/if.c b/sys/net/if.c
index e6546df..7097eb2 100644 (file)
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if.c,v 1.558 2018/07/11 09:08:21 henning Exp $        */
+/*     $OpenBSD: if.c,v 1.559 2018/08/09 03:35:19 akoshibe Exp $       */
 /*     $NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $  */
 
 /*
@@ -1743,6 +1743,10 @@ if_setrdomain(struct ifnet *ifp, int rdomain)
        if (rdomain < 0 || rdomain > RT_TABLEID_MAX)
                return (EINVAL);
 
+       if ((ifp->if_flags & IFF_LOOPBACK) &&
+           (ifp->if_index == rtable_loindex(ifp->if_rdomain)))
+               return (EPERM);
+
        /*
         * Create the routing table if it does not exist, including its
         * loopback interface with unit == rdomain.
@@ -1777,10 +1781,6 @@ if_setrdomain(struct ifnet *ifp, int rdomain)
                return (EINVAL);
 
        if (rdomain != ifp->if_rdomain) {
-               if ((ifp->if_flags & IFF_LOOPBACK) &&
-                   (ifp->if_index == rtable_loindex(ifp->if_rdomain)))
-                       return (EPERM);
-
                s = splnet();
                /*
                 * We are tearing down the world.