route: prefer interfaces with a carrier

diff --git a/src/route.c b/src/route.c
index 5a50957ca20584eb25d9f03b67b4a9e48253b972..9edac1ef643126200e684e2cecdd6bcfce026cee 100644 (file)
--- a/src/route.c
+++ b/src/route.c
@@ -91,6 +91,7 @@ rt_compare(void *context, const void *node1, const void *node2)
        const struct rt *rt1 = node1, *rt2 = node2;
        bool rt1u, rt2u;
        int c;
+       struct interface *ifp1, *ifp2;
 
        /* Default routes come last. */
        rt1u = !(rt1->rt_flags & RTF_HOST) &&
@@ -110,18 +111,25 @@ rt_compare(void *context, const void *node1, const void *node2)
        if (c != 0)
                return c;
 
+       /* All other checks are by interface. */
+       if (rt1->rt_ifp == NULL || rt2->rt_ifp == NULL)
+               return 0;
+       ifp1 = rt1->rt_ifp;
+       ifp2 = rt2->rt_ifp;
+
+       /* Prefer interfaces with a carrier */
+       c = ifp1->carrier - ifp2->carrier;
+       if (c != 0)
+               return -c;
+
 #ifndef HAVE_ROUTE_METRIC
        if (context == &rt_compare_os)
-               return c;
+               return 0;
 #else
        UNUSED(context);
 #endif
-       if (rt1->rt_ifp == NULL || rt2->rt_ifp == NULL)
-               c = 0;
-       else
-               c = (int)(rt1->rt_ifp->metric - rt2->rt_ifp->metric);
-
-       return c;
+       /* Lower metric interfaces come first */
+       return (int)(ifp1->metric - ifp2->metric);
 }
 
 static const rb_tree_ops_t rt_compare_os_ops = {