move several query.c helper functions to client.c and rename

- these formerly static helper functions have been moved into client.c
  and made external so that they can be used in hook modules as well as
  internally in libns: query_newrdataset, query_putrdataset,
  query_newnamebuf, query_newname, query_getnamebuf, query_keepname,
  query_releasename, query_newdbversion, query_findversion
- made query_recurse() and query_done() into public functions
  ns_query_recurse() and ns_query_done() so they can be called from
  modules.

bin/named/server.c

@@ -102,6 +102,7 @@
 #include <dst/result.h>
 
 #include <ns/client.h>
+#include <ns/hooks.h>
 #include <ns/listenlist.h>
 #include <ns/interfacemgr.h>
 

lib/ns/client.c

@@ -3981,3 +3981,239 @@ ns_client_sourceip(dns_clientinfo_t *ci, isc_sockaddr_t **addrp) {
 	*addrp = &client->peeraddr;
 	return (ISC_R_SUCCESS);
 }
+
+dns_rdataset_t *
+ns_client_newrdataset(ns_client_t *client) {
+	dns_rdataset_t *rdataset;
+	isc_result_t result;
+
+	REQUIRE(NS_CLIENT_VALID(client));
+
+	rdataset = NULL;
+	result = dns_message_gettemprdataset(client->message, &rdataset);
+	if (result != ISC_R_SUCCESS) {
+		return (NULL);
+	}
+
+	return (rdataset);
+}
+
+void
+ns_client_putrdataset(ns_client_t *client, dns_rdataset_t **rdatasetp) {
+	dns_rdataset_t *rdataset;
+
+	REQUIRE(NS_CLIENT_VALID(client));
+	REQUIRE(rdatasetp != NULL);
+
+	rdataset = *rdatasetp;
+
+	if (rdataset != NULL) {
+		if (dns_rdataset_isassociated(rdataset)) {
+			dns_rdataset_disassociate(rdataset);
+		}
+		dns_message_puttemprdataset(client->message, rdatasetp);
+	}
+}
+
+isc_result_t
+ns_client_newnamebuf(ns_client_t *client) {
+	isc_buffer_t *dbuf;
+	isc_result_t result;
+
+	CTRACE("ns_client_newnamebuf");
+
+	dbuf = NULL;
+	result = isc_buffer_allocate(client->mctx, &dbuf, 1024);
+	if (result != ISC_R_SUCCESS) {
+		CTRACE("ns_client_newnamebuf: "
+		       "isc_buffer_allocate failed: done");
+		return (result);
+	}
+	ISC_LIST_APPEND(client->query.namebufs, dbuf, link);
+
+	CTRACE("ns_client_newnamebuf: done");
+	return (ISC_R_SUCCESS);
+}
+
+dns_name_t *
+ns_client_newname(ns_client_t *client, isc_buffer_t *dbuf, isc_buffer_t *nbuf) {
+	dns_name_t *name;
+	isc_region_t r;
+	isc_result_t result;
+
+	REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) == 0);
+
+	CTRACE("ns_client_newname");
+	name = NULL;
+	result = dns_message_gettempname(client->message, &name);
+	if (result != ISC_R_SUCCESS) {
+		CTRACE("ns_client_newname: "
+		       "dns_message_gettempname failed: done");
+		return (NULL);
+	}
+	isc_buffer_availableregion(dbuf, &r);
+	isc_buffer_init(nbuf, r.base, r.length);
+	dns_name_init(name, NULL);
+	dns_name_setbuffer(name, nbuf);
+	client->query.attributes |= NS_QUERYATTR_NAMEBUFUSED;
+
+	CTRACE("ns_client_newname: done");
+	return (name);
+}
+
+isc_buffer_t *
+ns_client_getnamebuf(ns_client_t *client) {
+	isc_buffer_t *dbuf;
+	isc_result_t result;
+	isc_region_t r;
+
+	CTRACE("ns_client_getnamebuf");
+
+	/*%
+	 * Return a name buffer with space for a maximal name, allocating
+	 * a new one if necessary.
+	 */
+	if (ISC_LIST_EMPTY(client->query.namebufs)) {
+		result = ns_client_newnamebuf(client);
+		if (result != ISC_R_SUCCESS) {
+		    CTRACE("ns_client_getnamebuf: "
+			   "ns_client_newnamebuf failed: done");
+			return (NULL);
+		}
+	}
+
+	dbuf = ISC_LIST_TAIL(client->query.namebufs);
+	INSIST(dbuf != NULL);
+	isc_buffer_availableregion(dbuf, &r);
+	if (r.length < DNS_NAME_MAXWIRE) {
+		result = ns_client_newnamebuf(client);
+		if (result != ISC_R_SUCCESS) {
+		    CTRACE("ns_client_getnamebuf: "
+			   "ns_client_newnamebuf failed: done");
+			return (NULL);
+
+		}
+		dbuf = ISC_LIST_TAIL(client->query.namebufs);
+		isc_buffer_availableregion(dbuf, &r);
+		INSIST(r.length >= 255);
+	}
+	CTRACE("ns_client_getnamebuf: done");
+	return (dbuf);
+}
+
+void
+ns_client_keepname(ns_client_t *client, dns_name_t *name, isc_buffer_t *dbuf) {
+	isc_region_t r;
+
+	CTRACE("ns_client_keepname");
+
+	/*%
+	 * 'name' is using space in 'dbuf', but 'dbuf' has not yet been
+	 * adjusted to take account of that.  We do the adjustment.
+	 */
+	REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) != 0);
+
+	dns_name_toregion(name, &r);
+	isc_buffer_add(dbuf, r.length);
+	dns_name_setbuffer(name, NULL);
+	client->query.attributes &= ~NS_QUERYATTR_NAMEBUFUSED;
+}
+
+void
+ns_client_releasename(ns_client_t *client, dns_name_t **namep) {
+	dns_name_t *name = *namep;
+
+	/*%
+	 * 'name' is no longer needed.  Return it to our pool of temporary
+	 * names.  If it is using a name buffer, relinquish its exclusive
+	 * rights on the buffer.
+	 */
+
+	CTRACE("ns_client_releasename");
+	if (dns_name_hasbuffer(name)) {
+		INSIST((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED)
+		       != 0);
+		client->query.attributes &= ~NS_QUERYATTR_NAMEBUFUSED;
+	}
+	dns_message_puttempname(client->message, namep);
+	CTRACE("ns_client_releasename: done");
+}
+
+isc_result_t
+ns_client_newdbversion(ns_client_t *client, unsigned int n) {
+	unsigned int i;
+	ns_dbversion_t *dbversion;
+
+	for (i = 0; i < n; i++) {
+		dbversion = isc_mem_get(client->mctx, sizeof(*dbversion));
+		if (dbversion != NULL) {
+			dbversion->db = NULL;
+			dbversion->version = NULL;
+			ISC_LIST_INITANDAPPEND(client->query.freeversions,
+					      dbversion, link);
+		} else {
+			/*
+			 * We only return ISC_R_NOMEMORY if we couldn't
+			 * allocate anything.
+			 */
+			if (i == 0) {
+				return (ISC_R_NOMEMORY);
+			} else {
+				return (ISC_R_SUCCESS);
+			}
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static inline ns_dbversion_t *
+client_getdbversion(ns_client_t *client) {
+	isc_result_t result;
+	ns_dbversion_t *dbversion;
+
+	if (ISC_LIST_EMPTY(client->query.freeversions)) {
+		result = ns_client_newdbversion(client, 1);
+		if (result != ISC_R_SUCCESS) {
+			return (NULL);
+		}
+	}
+	dbversion = ISC_LIST_HEAD(client->query.freeversions);
+	INSIST(dbversion != NULL);
+	ISC_LIST_UNLINK(client->query.freeversions, dbversion, link);
+
+	return (dbversion);
+}
+
+ns_dbversion_t *
+ns_client_findversion(ns_client_t *client, dns_db_t *db) {
+	ns_dbversion_t *dbversion;
+
+	for (dbversion = ISC_LIST_HEAD(client->query.activeversions);
+	     dbversion != NULL;
+	     dbversion = ISC_LIST_NEXT(dbversion, link))
+	{
+		if (dbversion->db == db) {
+			break;
+		}
+	}
+
+	if (dbversion == NULL) {
+		/*
+		 * This is a new zone for this query.  Add it to
+		 * the active list.
+		 */
+		dbversion = client_getdbversion(client);
+		if (dbversion == NULL) {
+			return (NULL);
+		}
+		dns_db_attach(db, &dbversion->db);
+		dns_db_currentversion(db, &dbversion->version);
+		dbversion->acl_checked = false;
+		dbversion->queryok = false;
+		ISC_LIST_APPEND(client->query.activeversions,
+				dbversion, link);
+	}
+
+	return (dbversion);
+}

lib/ns/include/ns/client.h

@@ -432,4 +432,71 @@ ns__client_request(isc_task_t *task, isc_event_t *event);
  * Handle client requests.
  * (Not intended for use outside this module and associated tests.)
  */
+
+dns_rdataset_t *
+ns_client_newrdataset(ns_client_t *client);
+
+void
+ns_client_putrdataset(ns_client_t *client, dns_rdataset_t **rdatasetp);
+/*%
+ * Get and release temporary rdatasets in the client message;
+ * used in query.c and in hook modules.
+ */
+
+isc_result_t
+ns_client_newnamebuf(ns_client_t *client);
+/*%
+ * Allocate a name buffer for the client message.
+ */
+
+dns_name_t *
+ns_client_newname(ns_client_t *client, isc_buffer_t *dbuf, isc_buffer_t *nbuf);
+/*%
+ * Get a temporary name for the client message.
+ */
+
+isc_buffer_t *
+ns_client_getnamebuf(ns_client_t *client);
+/*%
+ * Get a name buffer from the pool, or allocate a new one if needed.
+ */
+
+void
+ns_client_keepname(ns_client_t *client, dns_name_t *name, isc_buffer_t *dbuf);
+/*%
+ * Adjust buffer 'dbuf' to reflect that 'name' is using space in it,
+ * and set client attributes appropriately.
+ */
+
+void
+ns_client_releasename(ns_client_t *client, dns_name_t **namep);
+/*%
+ * Release 'name' back to the pool of temporary names for the client
+ * message. If it is using a name buffer, relinquish its exclusive
+ * rights on the buffer.
+ */
+
+isc_result_t
+ns_client_newdbversion(ns_client_t *client, unsigned int n);
+/*%
+ * Allocate 'n' new database versions for use by client queries.
+ */
+
+ns_dbversion_t *
+ns_client_getdbversion(ns_client_t *client);
+/*%
+ * Get a free database version for use by a client query, allocating
+ * a new one if necessary.
+ */
+
+ns_dbversion_t *
+ns_client_findversion(ns_client_t *client, dns_db_t *db);
+/*%
+ * Find the correct database version to use with a client query.
+ * If we have already done a query related to the database 'db',
+ * make sure subsequent queries are from the same version;
+ * otherwise, take a database version from the list of dbversions
+ * allocated by ns_client_newdbversion().
+ */
+
 #endif /* NS_CLIENT_H */

lib/ns/include/ns/query.h

@@ -171,6 +171,35 @@ typedef struct query_ctx {
 	int line;				/* line to report error */
 } query_ctx_t;
 
+/*
+ * The following functions are expected to be used only within query.c
+ * and query modules.
+ */
+
+isc_result_t
+ns_query_done(query_ctx_t *qctx);
+/*%<
+ * Finalize this phase of the query process:
+ *
+ * - Clean up.
+ * - If we have an answer ready (positive or negative), send it.
+ * - If we need to restart for a chaining query, call ns__query_start() again.
+ * - If we've started recursion, then just clean up; things will be
+ *   restarted via fetch_callback()/query_resume().
+ */
+
+isc_result_t
+ns_query_recurse(ns_client_t *client, dns_rdatatype_t qtype, dns_name_t *qname,
+		 dns_name_t *qdomain, dns_rdataset_t *nameservers,
+		 bool resuming);
+/*%<
+ * Prepare client for recursion, then create a resolver fetch, with
+ * the event callback set to fetch_callback(). Afterward we terminate
+ * this phase of the query, and resume with a new query context when
+ * recursion completes.
+ */
+
+
 isc_result_t
 ns_query_init(ns_client_t *client);
 

lib/ns/tests/query_test.c

@@ -91,7 +91,7 @@ run_sfcache_test(const ns__query_sfcache_test_params_t *test) {
 		test->cache_entry_flags == 0);
 
 	/*
-	 * Interrupt execution if query_done() is called.
+	 * Interrupt execution if ns_query_done() is called.
 	 */
 	ns_hook_t hook = {
 		.callback = ns_test_hook_catch_call,
@@ -292,7 +292,7 @@ run_start_test(const ns__query_start_test_params_t *test) {
 		 test->auth_zone_path != NULL));
 
 	/*
-	 * Interrupt execution if query_lookup() or query_done() is called.
+	 * Interrupt execution if query_lookup() or ns_query_done() is called.
 	 */
 	ns_hook_t hook = {
 		.callback = ns_test_hook_catch_call,

lib/ns/win32/libns.def

@@ -62,8 +62,10 @@ ns_log_init
 ns_log_setcontext
 ns_notify_start
 ns_query_cancel
+ns_query_done
 ns_query_free
 ns_query_init
+ns_query_recurse
 ns_query_start
 ns_server_attach
 ns_server_create