Add +maxtotalqueries option to delv

The max-query-count value can now be set on the command line in delv
with +maxtotalqueries.

bin/delv/delv.c

@@ -94,6 +94,7 @@
 #define MAXNAME (DNS_NAME_MAXTEXT + 1)
 
 #define MAX_QUERIES  32
+#define MAX_TOTAL    200
 #define MAX_RESTARTS 11
 
 /* Variables used internally by delv. */
@@ -138,6 +139,7 @@ static bool showcomments = true, showdnssec = true, showtrust = true,
 	    yaml = false, fulltrace = false;
 
 static uint32_t maxqueries = MAX_QUERIES;
+static uint32_t maxtotal = MAX_TOTAL;
 static uint32_t restarts = MAX_RESTARTS;
 
 static bool resolve_trace = false, validator_trace = false,
@@ -1168,22 +1170,46 @@ plus_option(char *option) {
 		break;
 	case 'm':
 		switch (cmd[1]) {
-		case 'a': /* maxqueries */
-			FULLCHECK("maxqueries");
-			if (value == NULL) {
-				goto need_value;
-			}
-			if (!state) {
+		case 'a':
+			switch (cmd[3]) {
+			case 'q': /* maxqueries */
+				FULLCHECK("maxqueries");
+				if (value == NULL) {
+					goto need_value;
+				}
+				if (!state) {
+					goto invalid_option;
+				}
+				result = parse_uint(&maxqueries, value,
+						    UINT_MAX, "maxqueries");
+				if (result != ISC_R_SUCCESS) {
+					fatal("Couldn't parse maxqueries");
+				}
+				if (maxqueries == 0) {
+					fatal("maxqueries must be nonzero");
+				}
+				break;
+			case 't': /* maxtotalqueries */
+				FULLCHECK("maxtotalqueries");
+				if (value == NULL) {
+					goto need_value;
+				}
+				if (!state) {
+					goto invalid_option;
+				}
+				result = parse_uint(&maxtotal, value, UINT_MAX,
+						    "maxtotalqueries");
+				if (result != ISC_R_SUCCESS) {
+					fatal("Couldn't parse maxtotalqueries");
+				}
+				if (maxtotal == 0) {
+					fatal("maxtotalqueries must be "
+					      "nonzero");
+				}
+				break;
+			default:
 				goto invalid_option;
 			}
-			result = parse_uint(&maxqueries, value, UINT_MAX,
-					    "maxqueries");
-			if (result != ISC_R_SUCCESS) {
-				fatal("Couldn't parse maxqueries");
-			}
-			if (maxqueries == 0) {
-				fatal("maxqueries must be nonzero");
-			}
 			break;
 		case 't': /* mtrace */
 			FULLCHECK("mtrace");
@@ -1931,6 +1957,7 @@ run_resolve(void *arg) {
 	CHECK(dns_client_create(mctx, loopmgr, netmgr, 0, tlsctx_client_cache,
 				&client, srcaddr4, srcaddr6));
 	dns_client_setmaxrestarts(client, restarts);
+	dns_client_setmaxqueries(client, maxtotal);
 
 	/* Set the nameserver */
 	if (server != NULL) {
@@ -2196,6 +2223,7 @@ run_server(void *arg) {
 	dns_cache_detach(&cache);
 	dns_view_setdstport(view, destport);
 	dns_view_setmaxrestarts(view, restarts);
+	dns_view_setmaxqueries(view, maxtotal);
 
 	CHECK(dns_rootns_create(mctx, dns_rdataclass_in, hintfile, &roothints));
 	dns_view_sethints(view, roothints);

bin/delv/delv.rst

@@ -353,6 +353,11 @@ assign values to options like the timeout interval. They have the form
    This option specifies the maximum number of queries to send to resolve
    a name before giving up. The default is 32.
 
+.. option:: +maxtotalqueries
+
+   This option specifies the maximum number of queries to send to resolve
+   a client request before giving up. The default is 200.
+
 .. option:: +trust, +notrust
 
    This option controls whether to display the trust level when printing a record.

lib/dns/client.c

@@ -16,6 +16,7 @@
 
 #include <isc/async.h>
 #include <isc/buffer.h>
+#include <isc/counter.h>
 #include <isc/loop.h>
 #include <isc/md.h>
 #include <isc/mem.h>
@@ -81,6 +82,7 @@ struct dns_client {
 	unsigned int find_timeout;
 	unsigned int find_udpretries;
 	uint8_t max_restarts;
+	uint8_t max_queries;
 
 	isc_refcount_t references;
 
@@ -91,6 +93,7 @@ struct dns_client {
 #define DEF_FIND_TIMEOUT    5
 #define DEF_FIND_UDPRETRIES 3
 #define DEF_MAX_RESTARTS    11
+#define DEF_MAX_QUERIES	    200
 
 /*%
  * Internal state for a single name resolution procedure
@@ -111,6 +114,7 @@ typedef struct resctx {
 	dns_fetch_t *fetch;
 	dns_namelist_t namelist;
 	isc_result_t result;
+	isc_counter_t *qc;
 	dns_clientresume_t *rev;
 	dns_rdataset_t *rdataset;
 	dns_rdataset_t *sigrdataset;
@@ -252,6 +256,7 @@ dns_client_create(isc_mem_t *mctx, isc_loopmgr_t *loopmgr, isc_nm_t *nm,
 		.loop = isc_loop_get(loopmgr, 0),
 		.nm = nm,
 		.max_restarts = DEF_MAX_RESTARTS,
+		.max_queries = DEF_MAX_QUERIES,
 	};
 
 	result = dns_dispatchmgr_create(mctx, loopmgr, nm,
@@ -395,6 +400,14 @@ dns_client_setmaxrestarts(dns_client_t *client, uint8_t max_restarts) {
 	client->max_restarts = max_restarts;
 }
 
+void
+dns_client_setmaxqueries(dns_client_t *client, uint8_t max_queries) {
+	REQUIRE(DNS_CLIENT_VALID(client));
+	REQUIRE(max_queries > 0);
+
+	client->max_queries = max_queries;
+}
+
 static isc_result_t
 getrdataset(isc_mem_t *mctx, dns_rdataset_t **rdatasetp) {
 	dns_rdataset_t *rdataset;
@@ -456,7 +469,7 @@ start_fetch(resctx_t *rctx) {
 
 	result = dns_resolver_createfetch(
 		rctx->view->resolver, dns_fixedname_name(&rctx->name),
-		rctx->type, NULL, NULL, NULL, NULL, 0, fopts, 0, NULL, NULL,
+		rctx->type, NULL, NULL, NULL, NULL, 0, fopts, 0, NULL, rctx->qc,
 		rctx->client->loop, fetch_done, rctx, rctx->rdataset,
 		rctx->sigrdataset, &rctx->fetch);
 
@@ -935,6 +948,11 @@ startresolve(dns_client_t *client, const dns_name_t *name,
 	rctx->magic = RCTX_MAGIC;
 	isc_refcount_increment(&client->references);
 
+	result = isc_counter_create(mctx, client->max_queries, &rctx->qc);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup;
+	}
+
 	ISC_LIST_APPEND(client->resctxs, rctx, link);
 
 	*transp = (dns_clientrestrans_t *)rctx;
@@ -949,6 +967,9 @@ cleanup:
 	if (sigrdataset != NULL) {
 		putrdataset(client->mctx, &sigrdataset);
 	}
+	if (rctx->qc != NULL) {
+		isc_counter_detach(&rctx->qc);
+	}
 	isc_mem_put(mctx, rctx, sizeof(*rctx));
 	isc_mem_put(mctx, rev, sizeof(*rev));
 
@@ -1042,6 +1063,9 @@ destroyrestrans(dns_clientrestrans_t **transp) {
 
 	rctx->magic = 0;
 
+	if (rctx->qc != NULL) {
+		isc_counter_detach(&rctx->qc);
+	}
 	isc_mem_put(mctx, rctx, sizeof(*rctx));
 }
 

lib/dns/include/dns/client.h

@@ -187,6 +187,19 @@ dns_client_setmaxrestarts(dns_client_t *client, uint8_t max_restarts);
  *\li	'max_restarts' is greater than 0.
  */
 
+void
+dns_client_setmaxqueries(dns_client_t *client, uint8_t max_queries);
+/*%<
+ * Set the number of permissible outgoing queries before we give up,
+ * This defaults to 200.
+ *
+ * Requires:
+ *
+ *\li	'client' is a valid client.
+
+ *\li	'max_queries' is greater than 0.
+ */
+
 typedef void (*dns_client_resolve_cb)(dns_client_t     *client,
 				      const dns_name_t *name,
 				      dns_namelist_t   *namelist,