Allows rejected routes to be kept and examined.

When 'import keep rejected' protocol option is activated, routes
rejected by the import filter are kept in the routing table, but they
are hidden and not propagated to other protocols. It is possible to
examine them using 'show route rejected'.

1 files changed, 79 insertions, 34 deletions

diff --git a/nest/rt-table.c b/nest/rt-table.c
index 118f4c25..421a05ea 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -69,7 +69,7 @@ net_route(rtable *tab, ip_addr a, int len)
     {
       a0 = ipa_and(a, ipa_mkmask(len));
       n = fib_find(&tab->fib, &a0, len);
-      if (n && n->routes)
+      if (n && rte_is_valid(n->routes))
 	return n;
       len--;
     }
@@ -139,8 +139,11 @@ rte_better(rte *new, rte *old)
 {
   int (*better)(rte *, rte *);
 
-  if (!old)
+  if (!rte_is_valid(old))
     return 1;
+  if (!rte_is_valid(new))
+    return 0;
+
   if (new->pref > old->pref)
     return 1;
   if (new->pref < old->pref)
@@ -399,9 +402,13 @@ rt_notify_accepted(struct announce_hook *ah, net *net, rte *new_changed, rte *ol
   rte *old_free = NULL;
   rte *r;
 
-  /* Used to track whether we met old_changed position. If it is NULL
-     it was the first and met it implicitly before current best route. */
-  int old_meet = (old_changed && !before_old) ? 1 : 0;
+  /* Used to track whether we met old_changed position. If before_old is NULL
+     old_changed was the first and we met it implicitly before current best route. */
+  int old_meet = old_changed && !before_old;
+
+  /* Note that before_old is either NULL or valid (not rejected) route.
+     If old_changed is valid, before_old have to be too. If old changed route
+     was not valid, caller must use NULL for both old_changed and before_old. */
 
   if (new_changed)
     stats->exp_updates_received++;
@@ -409,7 +416,7 @@ rt_notify_accepted(struct announce_hook *ah, net *net, rte *new_changed, rte *ol
     stats->exp_withdraws_received++;
 
   /* First, find the new_best route - first accepted by filters */
-  for (r=net->routes; r; r=r->next)
+  for (r=net->routes; rte_is_valid(r); r=r->next)
     {
       if (new_best = export_filter(ah, r, &new_free, &tmpa, 0))
 	break;
@@ -428,7 +435,8 @@ rt_notify_accepted(struct announce_hook *ah, net *net, rte *new_changed, rte *ol
   if (feed)
     {
       if (feed == 2)	/* refeed */
-	old_best = new_best ? new_best : net->routes;
+	old_best = new_best ? new_best :
+	  (rte_is_valid(net->routes) ? net->routes : NULL);
       else
 	old_best = NULL;
 
@@ -477,7 +485,7 @@ rt_notify_accepted(struct announce_hook *ah, net *net, rte *new_changed, rte *ol
     }
 
   /* Fourth case */
-  for (r=r->next; r; r=r->next)
+  for (r=r->next; rte_is_valid(r); r=r->next)
     {
       if (old_best = export_filter(ah, r, &old_free, NULL, 1))
 	goto found;
@@ -531,7 +539,14 @@ rt_notify_accepted(struct announce_hook *ah, net *net, rte *new_changed, rte *ol
 static void
 rte_announce(rtable *tab, unsigned type, net *net, rte *new, rte *old, rte *before_old, ea_list *tmpa)
 {
-  struct announce_hook *a;
+  if (!rte_is_valid(old))
+    old = before_old = NULL;
+
+  if (!rte_is_valid(new))
+    new = NULL;
+
+  if (!old && !new)
+    return;
 
   if (type == RA_OPTIMAL)
     {
@@ -544,6 +559,7 @@ rte_announce(rtable *tab, unsigned type, net *net, rte *new, rte *old, rte *befo
 	rt_notify_hostcache(tab, net);
     }
 
+  struct announce_hook *a;
   WALK_LIST(a, tab->hooks)
     {
       ASSERT(a->proto->core_state == FS_HAPPY || a->proto->core_state == FS_FEEDING);
@@ -650,8 +666,13 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
 	  if (new && rte_same(old, new))
 	    {
 	      /* No changes, ignore the new route */
-	      stats->imp_updates_ignored++;
-	      rte_trace_in(D_ROUTES, p, new, "ignored");
+
+	      if (!rte_is_rejected(new))
+		{
+		  stats->imp_updates_ignored++;
+		  rte_trace_in(D_ROUTES, p, new, "ignored");
+		}
+
 	      rte_free_quick(new);
 #ifdef CONFIG_RIP
 	      /* lastmod is used internally by RIP as the last time
@@ -680,8 +701,10 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
   struct proto_limit *l = ah->in_limit;
   if (l && !old && new)
     {
-      if (stats->imp_routes >= l->limit)
-	proto_notify_limit(ah, l, stats->imp_routes);
+      u32 all_routes = stats->imp_routes + stats->rej_routes;
+
+      if (all_routes >= l->limit)
+	proto_notify_limit(ah, l, all_routes);
 
       if (l->state == PLS_BLOCKED)
 	{
@@ -692,15 +715,15 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
 	}
     }
 
-  if (new)
+  if (new && !rte_is_rejected(new))
     stats->imp_updates_accepted++;
   else
     stats->imp_withdraws_accepted++;
 
   if (new)
-    stats->imp_routes++;
+    rte_is_rejected(new) ? stats->rej_routes++ : stats->imp_routes++;
   if (old)
-    stats->imp_routes--;
+    rte_is_rejected(old) ? stats->rej_routes-- : stats->imp_routes--;
 
   if (table->config->sorted)
     {
@@ -900,27 +923,41 @@ rte_update2(struct announce_hook *ah, net *net, rte *new, struct proto *src)
 	  stats->imp_updates_invalid++;
 	  goto drop;
 	}
+
       if (filter == FILTER_REJECT)
 	{
 	  stats->imp_updates_filtered++;
 	  rte_trace_in(D_FILTERS, p, new, "filtered out");
-	  goto drop;
+
+	  if (! ah->in_keep_rejected)
+	    goto drop;
+
+	  /* new is a private copy, i could modify it */
+	  new->flags |= REF_REJECTED;
 	}
-      if (src->make_tmp_attrs)
-	tmpa = src->make_tmp_attrs(new, rte_update_pool);
-      if (filter)
+      else
 	{
-	  ea_list *old_tmpa = tmpa;
-	  int fr = f_run(filter, &new, &tmpa, rte_update_pool, 0);
-	  if (fr > F_ACCEPT)
+	  if (src->make_tmp_attrs)
+	    tmpa = src->make_tmp_attrs(new, rte_update_pool);
+	  if (filter && (filter != FILTER_REJECT))
 	    {
-	      stats->imp_updates_filtered++;
-	      rte_trace_in(D_FILTERS, p, new, "filtered out");
-	      goto drop;
+	      ea_list *old_tmpa = tmpa;
+	      int fr = f_run(filter, &new, &tmpa, rte_update_pool, 0);
+	      if (fr > F_ACCEPT)
+		{
+		  stats->imp_updates_filtered++;
+		  rte_trace_in(D_FILTERS, p, new, "filtered out");
+
+		  if (! ah->in_keep_rejected)
+		    goto drop;
+
+		  new->flags |= REF_REJECTED;
+		}
+	      if (tmpa != old_tmpa && src->store_tmp_attrs)
+		src->store_tmp_attrs(new, tmpa);
 	    }
-	  if (tmpa != old_tmpa && src->store_tmp_attrs)
-	    src->store_tmp_attrs(new, tmpa);
 	}
+
       if (!(new->attrs->aflags & RTAF_CACHED)) /* Need to copy attributes */
 	new->attrs = rta_lookup(new->attrs);
       new->flags |= REF_COW;
@@ -1553,9 +1590,11 @@ again:
 	  return 0;
 	}
 
+      /* XXXX perhaps we should change feed for RA_ACCEPTED to not use 'new' */
+
       if ((p->accept_ra_types == RA_OPTIMAL) ||
 	  (p->accept_ra_types == RA_ACCEPTED))
-	if (e)
+	if (rte_is_valid(e))
 	  {
 	    if (p->core_state != FS_FEEDING)
 	      return 1;  /* In the meantime, the protocol fell down. */
@@ -1564,7 +1603,7 @@ again:
 	  }
 
       if (p->accept_ra_types == RA_ANY)
-	for(e = n->routes; e != NULL; e = e->next)
+	for(e = n->routes; rte_is_valid(e); e = e->next)
 	  {
 	    if (p->core_state != FS_FEEDING)
 	      return 1;  /* In the meantime, the protocol fell down. */
@@ -1817,7 +1856,8 @@ rt_update_hostentry(rtable *tab, struct hostentry *he)
   net *n = net_route(tab, he->addr, MAX_PREFIX_LENGTH);
   if (n)
     {
-      rta *a = n->routes->attrs;
+      rte *e = n->routes;
+      rta *a = e->attrs;
       pxlen = n->n.pxlen;
 
       if (a->hostentry)
@@ -1850,7 +1890,7 @@ rt_update_hostentry(rtable *tab, struct hostentry *he)
 	}
 
       he->src = rta_clone(a);
-      he->igp_metric = rt_get_igp_metric(n->routes);
+      he->igp_metric = rt_get_igp_metric(e);
     }
 
  done:
@@ -1980,14 +2020,19 @@ rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
   int ok;
 
   bsprintf(ia, "%I/%d", n->n.prefix, n->n.pxlen);
-  if (n->routes)
-    d->net_counter++;
+
   for(e=n->routes; e; e=e->next)
     {
+      if (rte_is_rejected(e) != d->rejected)
+	continue;
+
       struct ea_list *tmpa;
       struct proto *p0 = e->attrs->proto;
       struct proto *p1 = d->export_protocol;
       struct proto *p2 = d->show_protocol;
+
+      if (ia[0])
+	d->net_counter++;
       d->rt_counter++;
       ee = e;
       rte_update_lock();		/* We use the update buffer for filtering */