Implements deterministic MED handling.

Thanks to Alexander V. Chernikov for many suggestions.

1 files changed, 29 insertions, 16 deletions

diff --git a/nest/rt-table.c b/nest/rt-table.c
index e20d2f6d..377687de 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -498,6 +498,9 @@ rte_recalculate(rtable *table, net *net, struct proto *p, struct proto *src, rte
 
   rte_announce(table, RA_ANY, net, new, old, tmpa);
 
+  if (src->rte_recalculate && src->rte_recalculate(table, net, new, old, old_best))
+    goto do_recalculate;
+
   if (new && rte_better(new, old_best))
     {
       /* The first case - the new route is cleary optimal, we link it
@@ -516,6 +519,7 @@ rte_recalculate(rtable *table, net *net, struct proto *p, struct proto *src, rte
 	 that route at the first position and announce it. New optimal
 	 route might be NULL if there is no more routes */
 
+    do_recalculate:
       /* Add the new route to the list */
       if (new)
 	{
@@ -1015,27 +1019,36 @@ rt_next_hop_update_net(rtable *tab, net *n)
   if (!old_best)
     return 0;
 
-  new_best = NULL;
-
   for (k = &n->routes; e = *k; k = &e->next)
-    {
-      if (rta_next_hop_outdated(e->attrs))
-	{
-	  new = rt_next_hop_update_rte(tab, e);
-	  *k = new;
+    if (rta_next_hop_outdated(e->attrs))
+      {
+	new = rt_next_hop_update_rte(tab, e);
+	*k = new;
 
-	  rte_announce_i(tab, RA_ANY, n, new, e);
-	  rte_trace_in(D_ROUTES, new->sender, new, "updated");
+	rte_announce_i(tab, RA_ANY, n, new, e);
+	rte_trace_in(D_ROUTES, new->sender, new, "updated");
 
-	  if (e != old_best)
-	    rte_free_quick(e);
-	  else /* Freeing of the old best rte is postponed */
-	    free_old_best = 1;
+	/* Call a pre-comparison hook */
+	/* Not really an efficient way to compute this */
+	if (e->attrs->proto->rte_recalculate)
+	  e->attrs->proto->rte_recalculate(tab, n, new, e, NULL);
 
-	  e = new;
-	  count++;
-	}
+	if (e != old_best)
+	  rte_free_quick(e);
+	else /* Freeing of the old best rte is postponed */
+	  free_old_best = 1;
 
+	e = new;
+	count++;
+      }
+
+  if (!count)
+    return 0;
+
+  /* Find the new best route */
+  new_best = NULL;
+  for (k = &n->routes; e = *k; k = &e->next)
+    {
       if (!new_best || rte_better(e, *new_best))
 	new_best = k;
     }