- if (defaultroute_exists(&rt, dfl_route_metric) && strcmp(rt.rt_dev, ifname) != 0) {
- if (rt.rt_flags & RTF_GATEWAY)
- error("not replacing existing default route via %I with metric %d",
- SIN_ADDR(rt.rt_gateway), dfl_route_metric);
- else
- error("not replacing existing default route through %s with metric %d",
- rt.rt_dev, dfl_route_metric);
- return 0;
+ if (default_rt_repl_rest) {
+ /* We have already replaced the original defaultroute, if we
+ * are called again, we will delete the current default route
+ * and set the new default route in this function.
+ * - this is normally only the case the doing demand: */
+ if (defaultroute_exists(&tmp_rt, -1))
+ del_rt = &tmp_rt;
+ } else if (defaultroute_exists(&old_def_rt, -1 ) &&
+ strcmp( old_def_rt.rt_dev, ifname) != 0) {
+ /*
+ * We did not yet replace an existing default route, let's
+ * check if we should save and replace a default route:
+ */
+ u_int32_t old_gateway = SIN_ADDR(old_def_rt.rt_gateway);
+
+ if (old_gateway != gateway) {
+ if (!replace) {
+ error("not replacing default route to %s [%I]",
+ old_def_rt.rt_dev, old_gateway);
+ return 0;
+ } else {
+ /* we need to copy rt_dev because we need it permanent too: */
+ char * tmp_dev = malloc(strlen(old_def_rt.rt_dev)+1);
+ strcpy(tmp_dev, old_def_rt.rt_dev);
+ old_def_rt.rt_dev = tmp_dev;
+
+ notice("replacing old default route to %s [%I]",
+ old_def_rt.rt_dev, old_gateway);
+ default_rt_repl_rest = 1;
+ del_rt = &old_def_rt;
+ }
+ }