From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Thu, 16 Aug 2012 11:09:26 +0000 (+0200)
Subject: Fixes a bug with neighbor cache and overlapping IP prefixes.
X-Git-Tag: v1.3.9~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8ecbaf9c70b802a1200ad37f2bfd4bc64173c5fe;p=thirdparty%2Fbird.git

Fixes a bug with neighbor cache and overlapping IP prefixes.

When there are overlapping IP prefixes and one disappears,
neighbors associated with it was removed even if there
is another covering IP prefix.
---

diff --git a/nest/neighbor.c b/nest/neighbor.c
index 506d9bdee..9dce81194 100644
--- a/nest/neighbor.c
+++ b/nest/neighbor.c
@@ -114,7 +114,7 @@ neighbor *
 neigh_find2(struct proto *p, ip_addr *a, struct iface *ifa, unsigned flags)
 {
   neighbor *n;
-  int class, scope = -1;       ;
+  int class, scope = -1;
   unsigned int h = neigh_hash(p, a);
   struct iface *i;
 
@@ -240,7 +240,21 @@ neigh_down(neighbor *n)
     n->proto->neigh_notify(n);
   rem_node(&n->n);
   if (n->flags & NEF_STICKY)
-    add_tail(&sticky_neigh_list, &n->n);
+    {
+      add_tail(&sticky_neigh_list, &n->n);
+
+      /* Respawn neighbor if there is another matching prefix */
+      struct iface *i;
+      int scope;
+
+      if (!n->iface)
+	WALK_LIST(i, iface_list)
+	  if ((scope = if_connected(&n->addr, i)) >= 0)
+	    {
+	      neigh_up(n, i, scope);
+	      return;
+	    }
+    }
   else
     sl_free(neigh_slab, n);
 }