From: Igor Putovny <igor.putovny@nic.cz>
Date: Thu, 6 Feb 2025 14:55:02 +0000 (+0100)
Subject: Do not set IN_FIB status for newly added prefixes
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b4f864f03667b6f22b21ea02fcc7491b042dd609;p=thirdparty%2Fbird.git

Do not set IN_FIB status for newly added prefixes

FIB status now truly reflects whether prefix is in export table or not.
Based on the change of FIB status, third pass can now decide whether
the export or route removal is needed.
---

diff --git a/proto/aggregator/aggregator.c b/proto/aggregator/aggregator.c
index ce2d09fbd..a1c17ad0e 100644
--- a/proto/aggregator/aggregator.c
+++ b/proto/aggregator/aggregator.c
@@ -422,7 +422,6 @@ trie_insert_prefix_ip4(struct trie_node * const root, const struct net_addr_ip4
 
   /* Assign bucket to the last node */
   node->original_bucket = bucket;
-  node->status = IN_FIB;
   node->px_origin = ORIGINAL;
 
   return node;
@@ -462,7 +461,6 @@ trie_insert_prefix_ip6(struct trie_node * const root, const struct net_addr_ip6
 
   /* Assign bucket to the last node */
   node->original_bucket = bucket;
-  node->status = IN_FIB;
   node->px_origin = ORIGINAL;
 
   return node;
@@ -631,7 +629,7 @@ first_pass(struct trie_node *node)
   {
     assert(node->original_bucket != NULL);
     assert(node->potential_buckets_count == 0);
-    assert(IN_FIB == node->status);
+    assert(NON_FIB == node->status);
     node_insert_potential_bucket(node, node->original_bucket);
     return;
   }
@@ -747,8 +745,19 @@ third_pass_helper(struct aggregator_proto *p, struct trie_node *node, struct net
    */
   if (is_bucket_potential(node, inherited_bucket))
   {
-    /* Selected bucket is NULL as it has never been assigned */
-    assert(node->selected_bucket == NULL);
+    /*
+     * Prefix status is changing from IN_FIB to NON_FIB, thus its route
+     * must be removed from the routing table.
+     */
+    if (IN_FIB == node->status)
+    {
+      assert(node->px_origin == ORIGINAL || node->px_origin == AGGREGATED);
+      assert(node->selected_bucket != NULL);
+
+      log("Planning to remove %s route for %N", px_origin_str[node->px_origin], addr);
+      push_rte_withdraw_ip4(p, addr, node->selected_bucket);
+    }
+
     node->selected_bucket = NULL;
     node->status = NON_FIB;
 
@@ -765,6 +774,18 @@ third_pass_helper(struct aggregator_proto *p, struct trie_node *node, struct net
 
     /* Assign bucket with the lowest ID to the node */
     node->selected_bucket = choose_lowest_id_bucket(p, node);
+    assert(node->selected_bucket != NULL);
+
+    /*
+     * Prefix status is changing from NON_FIB to IN_FIB, thus its route
+     * must be exported to the routing table.
+     */
+    if (NON_FIB == node->status)
+    {
+      log("Exporting %s route for %N", px_origin_str[node->px_origin], addr);
+      create_route_ip4(p, node->selected_bucket, addr);
+    }
+
     node->status = IN_FIB;
 
     /*
@@ -772,7 +793,6 @@ third_pass_helper(struct aggregator_proto *p, struct trie_node *node, struct net
      * is changed to aggregated, because it's going to FIB.
      */
     node->px_origin = ORIGINAL == node->px_origin ? ORIGINAL : AGGREGATED;
-    assert(node->selected_bucket != NULL);
   }
 
   assert((node->selected_bucket != NULL && node->status == IN_FIB) || (node->selected_bucket == NULL && node->status == NON_FIB));
@@ -967,11 +987,9 @@ deaggregate(struct trie_node * const node)
   if (ORIGINAL == node->px_origin)
   {
     assert(node->original_bucket != NULL);
-    node->status = IN_FIB;
   }
   else
   {
-    node->status = NON_FIB;
     node->original_bucket = node->parent->original_bucket;
     assert(node->original_bucket != NULL);
   }
@@ -981,7 +999,6 @@ deaggregate(struct trie_node * const node)
   /* As in the first pass, leaves get one potential bucket */
   if (is_leaf(node))
   {
-    assert(node->status == IN_FIB);
     assert(node->px_origin == ORIGINAL);
     assert(node->potential_buckets_count == 0);
     node_insert_potential_bucket(node, node->original_bucket);
@@ -1065,10 +1082,9 @@ trie_process_update(struct aggregator_proto *p, struct aggregator_route *old, st
 
   assert(updated_node != NULL);
   assert(updated_node->original_bucket != NULL);
-  assert(updated_node->status == IN_FIB);
-
   assert(updated_node->potential_buckets_count == 1);
   assert(BIT32R_TEST(updated_node->potential_buckets, updated_node->original_bucket->id));
+  assert(updated_node->status == NON_FIB);
 
   struct trie_node *node = updated_node;