Remove different zero TTL handling for rdataset iterator

Zero TTL handling does not need to be different for 'rdatasetiter_first'
and 'rdatasetiter_next' and it interacts badly with 'bind_rdatadataset'
which makes different determinations.

(cherry picked from commit 1a39328feb488c1d406a1b2d15dc6e0f882dce55)

diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 31a50a565dc12f9079a1565ce69ff93840ecb186..681f7fe4e16a71d8a2891ef0adf7be6b1446c149 100644 (file)
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -9159,6 +9159,35 @@ rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp) {
        *iteratorp = NULL;
 }
 
+static bool
+iterator_active(dns_rbtdb_t *rbtdb, rbtdb_rdatasetiter_t *rbtiterator,
+               rdatasetheader_t *header) {
+       dns_ttl_t stale_ttl = header->rdh_ttl + rbtdb->serve_stale_ttl;
+
+       /*
+        * Is this a "this rdataset doesn't exist" record?
+        */
+       if (NONEXISTENT(header)) {
+               return (false);
+       }
+
+       /*
+        * If this is a zone or this header still active then return it.
+        */
+       if (!IS_CACHE(rbtdb) || ACTIVE(header, rbtiterator->common.now)) {
+               return (true);
+       }
+
+       /*
+        * If we are not returning stale records or the rdataset is
+        * too old don't return it.
+        */
+       if (!STALEOK(rbtiterator) || (rbtiterator->common.now > stale_ttl)) {
+               return (false);
+       }
+       return (true);
+}
+
 static isc_result_t
 rdatasetiter_first(dns_rdatasetiter_t *iterator) {
        rbtdb_rdatasetiter_t *rbtiterator = (rbtdb_rdatasetiter_t *)iterator;
@@ -9166,16 +9195,7 @@ rdatasetiter_first(dns_rdatasetiter_t *iterator) {
        dns_rbtnode_t *rbtnode = rbtiterator->common.node;
        rbtdb_version_t *rbtversion = rbtiterator->common.version;
        rdatasetheader_t *header, *top_next;
-       rbtdb_serial_t serial;
-       isc_stdtime_t now;
-
-       if (IS_CACHE(rbtdb)) {
-               serial = 1;
-               now = rbtiterator->common.now;
-       } else {
-               serial = rbtversion->serial;
-               now = 0;
-       }
+       rbtdb_serial_t serial = IS_CACHE(rbtdb) ? 1 : rbtversion->serial;
 
        NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
                  isc_rwlocktype_read);
@@ -9183,10 +9203,6 @@ rdatasetiter_first(dns_rdatasetiter_t *iterator) {
        for (header = rbtnode->data; header != NULL; header = top_next) {
                top_next = header->next;
                do {
-                       dns_ttl_t stale_ttl = header->rdh_ttl;
-                       if (STALEOK(rbtiterator)) {
-                               stale_ttl += rbtdb->serve_stale_ttl;
-                       }
                        if (EXPIREDOK(rbtiterator)) {
                                if (!NONEXISTENT(header)) {
                                        break;
@@ -9194,17 +9210,9 @@ rdatasetiter_first(dns_rdatasetiter_t *iterator) {
                                header = header->down;
                        } else if (header->serial <= serial && !IGNORE(header))
                        {
-                               /*
-                                * Is this a "this rdataset doesn't exist"
-                                * record?  Or is it too old in the cache?
-                                *
-                                * Note: unlike everywhere else, we
-                                * check for now > header->rdh_ttl instead
-                                * of ">=".  This allows ANY and RRSIG
-                                *  queries for 0 TTL rdatasets to work.
-                                */
-                               if (NONEXISTENT(header) ||
-                                   (now != 0 && now > stale_ttl)) {
+                               if (!iterator_active(rbtdb, rbtiterator,
+                                                    header))
+                               {
                                        header = NULL;
                                }
                                break;
@@ -9236,8 +9244,7 @@ rdatasetiter_next(dns_rdatasetiter_t *iterator) {
        dns_rbtnode_t *rbtnode = rbtiterator->common.node;
        rbtdb_version_t *rbtversion = rbtiterator->common.version;
        rdatasetheader_t *header, *top_next;
-       rbtdb_serial_t serial;
-       isc_stdtime_t now;
+       rbtdb_serial_t serial = IS_CACHE(rbtdb) ? 1 : rbtversion->serial;
        rbtdb_rdatatype_t type, negtype;
        dns_rdatatype_t rdtype, covers;
        bool expiredok = EXPIREDOK(rbtiterator);
@@ -9247,14 +9254,6 @@ rdatasetiter_next(dns_rdatasetiter_t *iterator) {
                return (ISC_R_NOMORE);
        }
 
-       if (IS_CACHE(rbtdb)) {
-               serial = 1;
-               now = rbtiterator->common.now;
-       } else {
-               serial = rbtversion->serial;
-               now = 0;
-       }
-
        NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
                  isc_rwlocktype_read);
 
@@ -9289,10 +9288,6 @@ rdatasetiter_next(dns_rdatasetiter_t *iterator) {
        for (; header != NULL; header = top_next) {
                top_next = header->next;
                do {
-                       dns_ttl_t stale_ttl = header->rdh_ttl;
-                       if (STALEOK(rbtiterator)) {
-                               stale_ttl += rbtdb->serve_stale_ttl;
-                       }
                        if (expiredok) {
                                if (!NONEXISTENT(header)) {
                                        break;
@@ -9300,17 +9295,9 @@ rdatasetiter_next(dns_rdatasetiter_t *iterator) {
                                header = header->down;
                        } else if (header->serial <= serial && !IGNORE(header))
                        {
-                               /*
-                                * Is this a "this rdataset doesn't
-                                * exist" record?
-                                *
-                                * Note: unlike everywhere else, we
-                                * check for now > header->ttl instead
-                                * of ">=".  This allows ANY and RRSIG
-                                * queries for 0 TTL rdatasets to work.
-                                */
-                               if (NONEXISTENT(header) ||
-                                   (now != 0 && now > stale_ttl)) {
+                               if (!iterator_active(rbtdb, rbtiterator,
+                                                    header))
+                               {
                                        header = NULL;
                                }
                                break;