Use common code to start prefetches & RPZ fetches

query_prefetch() and query_rpzfetch() contain a lot of duplicated code.
Extract the common bits into a separate function whose name clearly
suggests its purpose.

diff --git a/lib/ns/query.c b/lib/ns/query.c
index 0f9cce64f7d3a215d51f437a6a41d9e7b342f9e6..c40d85ccf1d9440d8ab41a57b15a3af57a111eb3 100644 (file)
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -2562,24 +2562,22 @@ prefetch_done(isc_task_t *task, isc_event_t *event) {
        isc_nmhandle_detach(&client->prefetchhandle);
 }
 
+/*
+ * Try initiating a fetch for the given 'qname' and 'qtype' (with any requested
+ * 'extra_fetch_options') that will be associated with 'client'.  If the
+ * recursive clients quota (or even soft quota) is reached or some other error
+ * occurs, just return without starting the fetch.  If a fetch is successfully
+ * created, its results will be cached upon successful completion, but no
+ * further actions will be taken afterwards.
+ */
 static void
-query_prefetch(ns_client_t *client, dns_name_t *qname,
-              dns_rdataset_t *rdataset) {
+fetch_and_forget(ns_client_t *client, dns_name_t *qname, dns_rdatatype_t qtype,
+                unsigned int extra_fetch_options) {
        isc_result_t result;
        isc_sockaddr_t *peeraddr;
        dns_rdataset_t *tmprdataset;
        unsigned int options;
 
-       CTRACE(ISC_LOG_DEBUG(3), "query_prefetch");
-
-       if (client->query.prefetch != NULL ||
-           client->view->prefetch_trigger == 0U ||
-           rdataset->ttl > client->view->prefetch_trigger ||
-           (rdataset->attributes & DNS_RDATASETATTR_PREFETCH) == 0)
-       {
-               return;
-       }
-
        result = recursionquota_attach_hard(client);
        if (result != ISC_R_SUCCESS) {
                return;
@@ -2594,9 +2592,9 @@ query_prefetch(ns_client_t *client, dns_name_t *qname,
        }
 
        isc_nmhandle_attach(client->handle, &client->prefetchhandle);
-       options = client->query.fetchoptions | DNS_FETCHOPT_PREFETCH;
+       options = client->query.fetchoptions | extra_fetch_options;
        result = dns_resolver_createfetch(
-               client->view->resolver, qname, rdataset->type, NULL, NULL, NULL,
+               client->view->resolver, qname, qtype, NULL, NULL, NULL,
                peeraddr, client->message->id, options, 0, NULL,
                client->manager->task, prefetch_done, client, tmprdataset, NULL,
                &client->query.prefetch);
@@ -2604,6 +2602,22 @@ query_prefetch(ns_client_t *client, dns_name_t *qname,
                ns_client_putrdataset(client, &tmprdataset);
                isc_nmhandle_detach(&client->prefetchhandle);
        }
+}
+
+static void
+query_prefetch(ns_client_t *client, dns_name_t *qname,
+              dns_rdataset_t *rdataset) {
+       CTRACE(ISC_LOG_DEBUG(3), "query_prefetch");
+
+       if (client->query.prefetch != NULL ||
+           client->view->prefetch_trigger == 0U ||
+           rdataset->ttl > client->view->prefetch_trigger ||
+           (rdataset->attributes & DNS_RDATASETATTR_PREFETCH) == 0)
+       {
+               return;
+       }
+
+       fetch_and_forget(client, qname, rdataset->type, DNS_FETCHOPT_PREFETCH);
 
        dns_rdataset_clearprefetch(rdataset);
        ns_stats_increment(client->manager->sctx->nsstats,
@@ -2768,41 +2782,13 @@ rpz_get_zbits(ns_client_t *client, dns_rdatatype_t ip_type,
 
 static void
 query_rpzfetch(ns_client_t *client, dns_name_t *qname, dns_rdatatype_t type) {
-       isc_result_t result;
-       isc_sockaddr_t *peeraddr;
-       dns_rdataset_t *tmprdataset;
-       unsigned int options;
-
        CTRACE(ISC_LOG_DEBUG(3), "query_rpzfetch");
 
        if (client->query.prefetch != NULL) {
                return;
        }
 
-       result = recursionquota_attach_hard(client);
-       if (result != ISC_R_SUCCESS) {
-               return;
-       }
-
-       tmprdataset = ns_client_newrdataset(client);
-
-       if (!TCP(client)) {
-               peeraddr = &client->peeraddr;
-       } else {
-               peeraddr = NULL;
-       }
-
-       options = client->query.fetchoptions;
-       isc_nmhandle_attach(client->handle, &client->prefetchhandle);
-       result = dns_resolver_createfetch(
-               client->view->resolver, qname, type, NULL, NULL, NULL, peeraddr,
-               client->message->id, options, 0, NULL, client->manager->task,
-               prefetch_done, client, tmprdataset, NULL,
-               &client->query.prefetch);
-       if (result != ISC_R_SUCCESS) {
-               ns_client_putrdataset(client, &tmprdataset);
-               isc_nmhandle_detach(&client->prefetchhandle);
-       }
+       fetch_and_forget(client, qname, type, 0);
 }
 
 /*