Fixes another bug in rte_recalculate().

Previous bugfix revealed another hidden bug here.

diff --git a/nest/rt-table.c b/nest/rt-table.c
index 72138362ffeeca8477cc4f9c1be677fbfdee5646..87bf0dc7dca7b70f795e6737bd41653c1c5cbbc5 100644 (file)
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -427,57 +427,87 @@ rte_recalculate(rtable *table, net *net, struct proto *p, struct proto *src, rte
 
   rte_announce(table, RA_ANY, net, new, old, tmpa);
 
-  if (new && rte_better(new, old_best))        /* It's a new optimal route => announce and relink it */
+  
+  if (new && rte_better(new, old_best))
     {
+      /* The first case - the new route is cleary optimal, we link it
+        at the first position and announce it */
+
       rte_trace_in(D_ROUTES, p, new, "added [best]");
       rte_announce(table, RA_OPTIMAL, net, new, old_best, tmpa);
       new->next = net->routes;
       net->routes = new;
     }
-  else
+  else if (old == old_best)
     {
-      if (old == old_best)             /* It has _replaced_ the old optimal route */
+      /* The second case - the old best route disappeared, we add the
+        new route (if we have any) to the list (we don't care about
+        position) and then we elect the new optimal route and relink
+        that route at the first position and announce it. New optimal
+        route might be NULL if there is no more routes */
+
+      /* Add the new route to the list */
+      if (new)
        {
-         r = new;                      /* Find new optimal route and announce it */
-         for(s=net->routes; s; s=s->next)
-           if (rte_better(s, r))
-             r = s;
-         rte_announce(table, RA_OPTIMAL, net, r, old_best, tmpa);
-         if (r)                        /* Re-link the new optimal route */
+         rte_trace_in(D_ROUTES, p, new, "added");
+         new->next = net->routes;
+         net->routes = new;
+       }
+
+      /* Find new optimal route */
+      r = NULL;
+      for (s=net->routes; s; s=s->next)
+       if (rte_better(s, r))
+         r = s;
+
+      /* Announce optimal route */
+      rte_announce(table, RA_OPTIMAL, net, r, old_best, tmpa);
+
+      /* And relink it (if there is any) */
+      if (r)
+       {
+         k = &net->routes;
+         while (s = *k)
            {
-             k = &net->routes;
-             while (s = *k)
+             if (s == r)
                {
-                 if (s == r)
-                   {
-                     *k = r->next;
-                     break;
-                   }
-                 k = &s->next;
+                 *k = r->next;
+                 break;
                }
-             r->next = net->routes;
-             net->routes = r;
+             k = &s->next;
            }
-         else if (table->gc_counter++ >= table->config->gc_max_ops &&
-                  table->gc_time + table->config->gc_min_time <= now)
-           ev_schedule(table->gc_event);
-       }
-      if (new)                         /* Link in the new non-optimal route */
-       {
-         new->next = net->routes->next;
-         net->routes->next = new;
-         rte_trace_in(D_ROUTES, p, new, "added");
-       }
-      else if (old && (p->debug & D_ROUTES))
-       {
-         if (old != old_best)
-           rte_trace_in(D_ROUTES, p, old, "removed");
-         else if (net->routes)
-           rte_trace_in(D_ROUTES, p, old, "removed [replaced]");
-         else
-           rte_trace_in(D_ROUTES, p, old, "removed [sole]");
+         r->next = net->routes;
+         net->routes = r;
        }
+      else if (table->gc_counter++ >= table->config->gc_max_ops &&
+              table->gc_time + table->config->gc_min_time <= now)
+       ev_schedule(table->gc_event);
+    }
+  else if (new)
+    {
+      /* The third case - the new route is not better than the old
+        best route (therefore old_best != NULL) and the old best
+        route was not removed (therefore old_best == net->routes).
+        We just link the new route after the old best route. */
+
+      ASSERT(net->routes != NULL);
+      new->next = net->routes->next;
+      net->routes->next = new;
+      rte_trace_in(D_ROUTES, p, new, "added");
     }
+  else if (old && (p->debug & D_ROUTES))
+    {
+      /* Not really a case - the list of routes is correct, we just
+        log the route removal */
+
+      if (old != old_best)
+       rte_trace_in(D_ROUTES, p, old, "removed");
+      else if (net->routes)
+       rte_trace_in(D_ROUTES, p, old, "removed [replaced]");
+      else
+       rte_trace_in(D_ROUTES, p, old, "removed [sole]");
+    }
+
   if (old)
     {
       if (p->rte_remove)