3260. [bug] "rrset-order cyclic" could appears to not rotate

                        for some query patterns.  [RT #27170]

diff --git a/CHANGES b/CHANGES
index ab6060de474b12a734f3f0b756f6d72ea3af28f2..500853a5a2e128c8d87fbbde6e88a975659ff576 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3260.  [bug]           "rrset-order cyclic" could appears to not rotate
+                       for some query patterns.  [RT #27170]
+
        --- 9.9.0rc1 released ---
 
 3259.  [bug]           named-compilezone: Suppress "dump zone to <file>"

diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index d4e7316dc3440f47585b02037a34b6b2c26de35d..c346118c553a72fc1f172518b160c2302678b5e9 100644 (file)
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: rbtdb.c,v 1.323 2011/12/07 22:21:05 marka Exp $ */
+/* $Id: rbtdb.c,v 1.324 2011/12/22 23:43:52 marka Exp $ */
 
 /*! \file */
 
@@ -2744,6 +2744,14 @@ zone_zonecut_callback(dns_rbtnode_t *node, dns_name_t *name, void *arg) {
        return (result);
 }
 
+static inline unsigned int
+prand(isc_uint32_t val) {
+       val ^= val >> 16;
+       val ^= val >> 8;
+       val ^= val >> 4;
+       return (val & 0xf);
+}
+
 static inline void
 bind_rdataset(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node,
              rdatasetheader_t *header, isc_stdtime_t now,
@@ -2783,6 +2791,8 @@ bind_rdataset(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node,
        raw = (unsigned char *)header + sizeof(*header);
        rdataset->private3 = raw;
        rdataset->count = header->count++;
+       /* Add a weak pseudo random value [0..15]. */
+       header->count += prand(header->count);
        if (rdataset->count == ISC_UINT32_MAX)
                rdataset->count = 0;