Do not add ::1 on non-default lo(4) as intended.

Reported by and ok sthen@

diff --git a/sys/netinet6/in6_ifattach.c b/sys/netinet6/in6_ifattach.c
index 7ea489a..2f8463e 100644 (file)
--- a/sys/netinet6/in6_ifattach.c
+++ b/sys/netinet6/in6_ifattach.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in6_ifattach.c,v 1.109 2018/07/10 20:44:39 florian Exp $      */
+/*     $OpenBSD: in6_ifattach.c,v 1.110 2018/08/26 22:30:00 mpi Exp $  */
 /*     $KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 jinmei Exp $  */
 
 /*
@@ -391,10 +391,14 @@ in6_ifattach_linklocal(struct ifnet *ifp, struct in6_addr *ifid)
 int
 in6_ifattach_loopback(struct ifnet *ifp)
 {
+       struct in6_addr in6 = in6addr_loopback;
        struct in6_aliasreq ifra;
 
        KASSERT(ifp->if_flags & IFF_LOOPBACK);
 
+       if (in6ifa_ifpwithaddr(ifp, &in6) != NULL)
+               return (0);
+
        bzero(&ifra, sizeof(ifra));
        strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name));
        ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
@@ -503,14 +507,14 @@ in6_ifattach(struct ifnet *ifp)
        if ((ifp->if_flags & IFF_MULTICAST) == 0)
                return (EINVAL);
 
-       /* Assign loopback address, if there's none. */
-       if (ifp->if_flags & IFF_LOOPBACK) {
-               struct in6_addr in6 = in6addr_loopback;
+       /*
+        * Assign loopback address if this lo(4) interface is the
+        * default for its rdomain.
+        */
+       if ((ifp->if_flags & IFF_LOOPBACK) &&
+           (ifp->if_index == rtable_loindex(ifp->if_rdomain))) {
                int error;
 
-               if (in6ifa_ifpwithaddr(ifp, &in6) != NULL)
-                       return (0);
-
                error = in6_ifattach_loopback(ifp);
                if (error)
                        return (error);