Adding upstream version 1:9.16.44.upstream/1%9.16.44upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 653 insertions, 0 deletions

diff --git a/lib/dns/stats.c b/lib/dns/stats.c
new file mode 100644
index 0000000..bdd98c5
--- /dev/null
+++ b/lib/dns/stats.c
@@ -0,0 +1,653 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/refcount.h>
+#include <isc/stats.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/opcode.h>
+#include <dns/rdatatype.h>
+#include <dns/stats.h>
+
+#define DNS_STATS_MAGIC	   ISC_MAGIC('D', 's', 't', 't')
+#define DNS_STATS_VALID(x) ISC_MAGIC_VALID(x, DNS_STATS_MAGIC)
+
+/*%
+ * Statistics types.
+ */
+typedef enum {
+	dns_statstype_general = 0,
+	dns_statstype_rdtype = 1,
+	dns_statstype_rdataset = 2,
+	dns_statstype_opcode = 3,
+	dns_statstype_rcode = 4,
+	dns_statstype_dnssec = 5
+} dns_statstype_t;
+
+/*%
+ * It doesn't make sense to have 2^16 counters for all possible types since
+ * most of them won't be used.  We have counters for the first 256 types.
+ *
+ * A rdtypecounter is now 8 bits for RRtypes and 3 bits for flags:
+ *
+ *       0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
+ *     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *     |  |  |  |  |  |  S  |NX|         RRType        |
+ *     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *
+ * If the 8 bits for RRtype are all zero, this is an Other RRtype.
+ */
+#define RDTYPECOUNTER_MAXTYPE 0x00ff
+
+/*
+ *
+ * Bit 7 is the NXRRSET (NX) flag and indicates whether this is a
+ * positive (0) or a negative (1) RRset.
+ */
+#define RDTYPECOUNTER_NXRRSET 0x0100
+
+/*
+ * Then bit 5 and 6 mostly tell you if this counter is for an active,
+ * stale, or ancient RRtype:
+ *
+ *     S = 0 (0b00) means Active
+ *     S = 1 (0b01) means Stale
+ *     S = 2 (0b10) means Ancient
+ *
+ * Since a counter cannot be stale and ancient at the same time, we
+ * treat S = 0b11 as a special case to deal with NXDOMAIN counters.
+ */
+#define RDTYPECOUNTER_STALE    (1 << 9)
+#define RDTYPECOUNTER_ANCIENT  (1 << 10)
+#define RDTYPECOUNTER_NXDOMAIN ((1 << 9) | (1 << 10))
+
+/*
+ * S = 0b11 indicates an NXDOMAIN counter and in this case the RRtype
+ * field signals the expiry of this cached item:
+ *
+ *     RRType = 0 (0b00) means Active
+ *     RRType = 1 (0b01) means Stale
+ *     RRType = 2 (0b02) means Ancient
+ *
+ */
+#define RDTYPECOUNTER_NXDOMAIN_STALE   1
+#define RDTYPECOUNTER_NXDOMAIN_ANCIENT 2
+
+/*
+ * The maximum value for rdtypecounter is for an ancient NXDOMAIN.
+ */
+#define RDTYPECOUNTER_MAXVAL 0x0602
+
+/*
+ * DNSSEC sign statistics.
+ *
+ * Per key we maintain 3 counters. The first is actually no counter but
+ * a key id reference. The second is the number of signatures the key created.
+ * The third is the number of signatures refreshed by the key.
+ */
+
+/* Maximum number of keys to keep track of for DNSSEC signing statistics. */
+static int dnssecsign_num_keys = 4;
+static int dnssecsign_block_size = 3;
+/* Key id mask */
+#define DNSSECSIGNSTATS_KEY_ID_MASK 0x0000FFFF
+
+struct dns_stats {
+	unsigned int magic;
+	dns_statstype_t type;
+	isc_mem_t *mctx;
+	isc_stats_t *counters;
+	isc_refcount_t references;
+};
+
+typedef struct rdatadumparg {
+	dns_rdatatypestats_dumper_t fn;
+	void *arg;
+} rdatadumparg_t;
+
+typedef struct opcodedumparg {
+	dns_opcodestats_dumper_t fn;
+	void *arg;
+} opcodedumparg_t;
+
+typedef struct rcodedumparg {
+	dns_rcodestats_dumper_t fn;
+	void *arg;
+} rcodedumparg_t;
+typedef struct dnssecsigndumparg {
+	dns_dnssecsignstats_dumper_t fn;
+	void *arg;
+} dnssecsigndumparg_t;
+
+void
+dns_stats_attach(dns_stats_t *stats, dns_stats_t **statsp) {
+	REQUIRE(DNS_STATS_VALID(stats));
+	REQUIRE(statsp != NULL && *statsp == NULL);
+
+	isc_refcount_increment(&stats->references);
+
+	*statsp = stats;
+}
+
+void
+dns_stats_detach(dns_stats_t **statsp) {
+	dns_stats_t *stats;
+
+	REQUIRE(statsp != NULL && DNS_STATS_VALID(*statsp));
+
+	stats = *statsp;
+	*statsp = NULL;
+
+	if (isc_refcount_decrement(&stats->references) == 1) {
+		isc_refcount_destroy(&stats->references);
+		isc_stats_detach(&stats->counters);
+		isc_mem_putanddetach(&stats->mctx, stats, sizeof(*stats));
+	}
+}
+
+/*%
+ * Create methods
+ */
+static isc_result_t
+create_stats(isc_mem_t *mctx, dns_statstype_t type, int ncounters,
+	     dns_stats_t **statsp) {
+	dns_stats_t *stats;
+	isc_result_t result;
+
+	stats = isc_mem_get(mctx, sizeof(*stats));
+
+	stats->counters = NULL;
+	isc_refcount_init(&stats->references, 1);
+
+	result = isc_stats_create(mctx, &stats->counters, ncounters);
+	if (result != ISC_R_SUCCESS) {
+		goto clean_mutex;
+	}
+
+	stats->magic = DNS_STATS_MAGIC;
+	stats->type = type;
+	stats->mctx = NULL;
+	isc_mem_attach(mctx, &stats->mctx);
+	*statsp = stats;
+
+	return (ISC_R_SUCCESS);
+
+clean_mutex:
+	isc_mem_put(mctx, stats, sizeof(*stats));
+
+	return (result);
+}
+
+isc_result_t
+dns_generalstats_create(isc_mem_t *mctx, dns_stats_t **statsp, int ncounters) {
+	REQUIRE(statsp != NULL && *statsp == NULL);
+
+	return (create_stats(mctx, dns_statstype_general, ncounters, statsp));
+}
+
+isc_result_t
+dns_rdatatypestats_create(isc_mem_t *mctx, dns_stats_t **statsp) {
+	REQUIRE(statsp != NULL && *statsp == NULL);
+
+	/*
+	 * Create rdtype statistics for the first 255 RRtypes,
+	 * plus one additional for other RRtypes.
+	 */
+	return (create_stats(mctx, dns_statstype_rdtype,
+			     (RDTYPECOUNTER_MAXTYPE + 1), statsp));
+}
+
+isc_result_t
+dns_rdatasetstats_create(isc_mem_t *mctx, dns_stats_t **statsp) {
+	REQUIRE(statsp != NULL && *statsp == NULL);
+
+	return (create_stats(mctx, dns_statstype_rdataset,
+			     (RDTYPECOUNTER_MAXVAL + 1), statsp));
+}
+
+isc_result_t
+dns_opcodestats_create(isc_mem_t *mctx, dns_stats_t **statsp) {
+	REQUIRE(statsp != NULL && *statsp == NULL);
+
+	return (create_stats(mctx, dns_statstype_opcode, 16, statsp));
+}
+
+isc_result_t
+dns_rcodestats_create(isc_mem_t *mctx, dns_stats_t **statsp) {
+	REQUIRE(statsp != NULL && *statsp == NULL);
+
+	return (create_stats(mctx, dns_statstype_rcode, dns_rcode_badcookie + 1,
+			     statsp));
+}
+
+isc_result_t
+dns_dnssecsignstats_create(isc_mem_t *mctx, dns_stats_t **statsp) {
+	REQUIRE(statsp != NULL && *statsp == NULL);
+
+	/*
+	 * Create two counters per key, one is the key id, the other two are
+	 * the actual counters for creating and refreshing signatures.
+	 */
+	return (create_stats(mctx, dns_statstype_dnssec,
+			     dnssecsign_num_keys * dnssecsign_block_size,
+			     statsp));
+}
+
+/*%
+ * Increment/Decrement methods
+ */
+void
+dns_generalstats_increment(dns_stats_t *stats, isc_statscounter_t counter) {
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_general);
+
+	isc_stats_increment(stats->counters, counter);
+}
+
+static isc_statscounter_t
+rdatatype2counter(dns_rdatatype_t type) {
+	if (type > (dns_rdatatype_t)RDTYPECOUNTER_MAXTYPE) {
+		return (0);
+	}
+	return ((isc_statscounter_t)type);
+}
+
+void
+dns_rdatatypestats_increment(dns_stats_t *stats, dns_rdatatype_t type) {
+	isc_statscounter_t counter;
+
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_rdtype);
+
+	counter = rdatatype2counter(type);
+	isc_stats_increment(stats->counters, counter);
+}
+
+static void
+update_rdatasetstats(dns_stats_t *stats, dns_rdatastatstype_t rrsettype,
+		     bool increment) {
+	isc_statscounter_t counter;
+
+	if ((DNS_RDATASTATSTYPE_ATTR(rrsettype) &
+	     DNS_RDATASTATSTYPE_ATTR_NXDOMAIN) != 0)
+	{
+		counter = RDTYPECOUNTER_NXDOMAIN;
+
+		/*
+		 * This is an NXDOMAIN counter, save the expiry value
+		 * (active, stale, or ancient) value in the RRtype part.
+		 */
+		if ((DNS_RDATASTATSTYPE_ATTR(rrsettype) &
+		     DNS_RDATASTATSTYPE_ATTR_ANCIENT) != 0)
+		{
+			counter |= RDTYPECOUNTER_NXDOMAIN_ANCIENT;
+		} else if ((DNS_RDATASTATSTYPE_ATTR(rrsettype) &
+			    DNS_RDATASTATSTYPE_ATTR_STALE) != 0)
+		{
+			counter += RDTYPECOUNTER_NXDOMAIN_STALE;
+		}
+	} else {
+		counter = rdatatype2counter(DNS_RDATASTATSTYPE_BASE(rrsettype));
+
+		if ((DNS_RDATASTATSTYPE_ATTR(rrsettype) &
+		     DNS_RDATASTATSTYPE_ATTR_NXRRSET) != 0)
+		{
+			counter |= RDTYPECOUNTER_NXRRSET;
+		}
+
+		if ((DNS_RDATASTATSTYPE_ATTR(rrsettype) &
+		     DNS_RDATASTATSTYPE_ATTR_ANCIENT) != 0)
+		{
+			counter |= RDTYPECOUNTER_ANCIENT;
+		} else if ((DNS_RDATASTATSTYPE_ATTR(rrsettype) &
+			    DNS_RDATASTATSTYPE_ATTR_STALE) != 0)
+		{
+			counter |= RDTYPECOUNTER_STALE;
+		}
+	}
+
+	if (increment) {
+		isc_stats_increment(stats->counters, counter);
+	} else {
+		isc_stats_decrement(stats->counters, counter);
+	}
+}
+
+void
+dns_rdatasetstats_increment(dns_stats_t *stats,
+			    dns_rdatastatstype_t rrsettype) {
+	REQUIRE(DNS_STATS_VALID(stats) &&
+		stats->type == dns_statstype_rdataset);
+
+	update_rdatasetstats(stats, rrsettype, true);
+}
+
+void
+dns_rdatasetstats_decrement(dns_stats_t *stats,
+			    dns_rdatastatstype_t rrsettype) {
+	REQUIRE(DNS_STATS_VALID(stats) &&
+		stats->type == dns_statstype_rdataset);
+
+	update_rdatasetstats(stats, rrsettype, false);
+}
+
+void
+dns_opcodestats_increment(dns_stats_t *stats, dns_opcode_t code) {
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_opcode);
+
+	isc_stats_increment(stats->counters, (isc_statscounter_t)code);
+}
+
+void
+dns_rcodestats_increment(dns_stats_t *stats, dns_rcode_t code) {
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_rcode);
+
+	if (code <= dns_rcode_badcookie) {
+		isc_stats_increment(stats->counters, (isc_statscounter_t)code);
+	}
+}
+
+void
+dns_dnssecsignstats_increment(dns_stats_t *stats, dns_keytag_t id, uint8_t alg,
+			      dnssecsignstats_type_t operation) {
+	uint32_t kval;
+	int num_keys = isc_stats_ncounters(stats->counters) /
+		       dnssecsign_block_size;
+
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_dnssec);
+
+	/* Shift algorithm in front of key tag, which is 16 bits */
+	kval = (uint32_t)(alg << 16 | id);
+
+	/* Look up correct counter. */
+	for (int i = 0; i < num_keys; i++) {
+		int idx = i * dnssecsign_block_size;
+		uint32_t counter = isc_stats_get_counter(stats->counters, idx);
+		if (counter == kval) {
+			/* Match */
+			isc_stats_increment(stats->counters, (idx + operation));
+			return;
+		}
+	}
+
+	/* No match found. Store key in unused slot. */
+	for (int i = 0; i < num_keys; i++) {
+		int idx = i * dnssecsign_block_size;
+		uint32_t counter = isc_stats_get_counter(stats->counters, idx);
+		if (counter == 0) {
+			isc_stats_set(stats->counters, kval, idx);
+			isc_stats_increment(stats->counters, (idx + operation));
+			return;
+		}
+	}
+
+	/* No room, grow stats storage. */
+	isc_stats_resize(&stats->counters,
+			 (num_keys * dnssecsign_block_size * 2));
+
+	/* Reset counters for new key (new index, nidx). */
+	int nidx = num_keys * dnssecsign_block_size;
+	isc_stats_set(stats->counters, kval, nidx);
+	isc_stats_set(stats->counters, 0, (nidx + dns_dnssecsignstats_sign));
+	isc_stats_set(stats->counters, 0, (nidx + dns_dnssecsignstats_refresh));
+
+	/* And increment the counter for the given operation. */
+	isc_stats_increment(stats->counters, (nidx + operation));
+}
+
+void
+dns_dnssecsignstats_clear(dns_stats_t *stats, dns_keytag_t id, uint8_t alg) {
+	uint32_t kval;
+	int num_keys = isc_stats_ncounters(stats->counters) /
+		       dnssecsign_block_size;
+
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_dnssec);
+
+	/* Shift algorithm in front of key tag, which is 16 bits */
+	kval = (uint32_t)(alg << 16 | id);
+
+	/* Look up correct counter. */
+	for (int i = 0; i < num_keys; i++) {
+		int idx = i * dnssecsign_block_size;
+		uint32_t counter = isc_stats_get_counter(stats->counters, idx);
+		if (counter == kval) {
+			/* Match */
+			isc_stats_set(stats->counters, 0, idx);
+			isc_stats_set(stats->counters, 0,
+				      (idx + dns_dnssecsignstats_sign));
+			isc_stats_set(stats->counters, 0,
+				      (idx + dns_dnssecsignstats_refresh));
+			return;
+		}
+	}
+}
+
+/*%
+ * Dump methods
+ */
+void
+dns_generalstats_dump(dns_stats_t *stats, dns_generalstats_dumper_t dump_fn,
+		      void *arg, unsigned int options) {
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_general);
+
+	isc_stats_dump(stats->counters, (isc_stats_dumper_t)dump_fn, arg,
+		       options);
+}
+
+static void
+dump_rdentry(int rdcounter, uint64_t value, dns_rdatastatstype_t attributes,
+	     dns_rdatatypestats_dumper_t dump_fn, void *arg) {
+	dns_rdatatype_t rdtype = dns_rdatatype_none; /* sentinel */
+	dns_rdatastatstype_t type;
+
+	if ((rdcounter & RDTYPECOUNTER_MAXTYPE) == 0) {
+		attributes |= DNS_RDATASTATSTYPE_ATTR_OTHERTYPE;
+	} else {
+		rdtype = (dns_rdatatype_t)(rdcounter & RDTYPECOUNTER_MAXTYPE);
+	}
+	type = DNS_RDATASTATSTYPE_VALUE((dns_rdatastatstype_t)rdtype,
+					attributes);
+	dump_fn(type, value, arg);
+}
+
+static void
+rdatatype_dumpcb(isc_statscounter_t counter, uint64_t value, void *arg) {
+	rdatadumparg_t *rdatadumparg = arg;
+
+	dump_rdentry(counter, value, 0, rdatadumparg->fn, rdatadumparg->arg);
+}
+
+void
+dns_rdatatypestats_dump(dns_stats_t *stats, dns_rdatatypestats_dumper_t dump_fn,
+			void *arg0, unsigned int options) {
+	rdatadumparg_t arg;
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_rdtype);
+
+	arg.fn = dump_fn;
+	arg.arg = arg0;
+	isc_stats_dump(stats->counters, rdatatype_dumpcb, &arg, options);
+}
+
+static void
+rdataset_dumpcb(isc_statscounter_t counter, uint64_t value, void *arg) {
+	rdatadumparg_t *rdatadumparg = arg;
+	unsigned int attributes = 0;
+
+	if ((counter & RDTYPECOUNTER_NXDOMAIN) == RDTYPECOUNTER_NXDOMAIN) {
+		attributes |= DNS_RDATASTATSTYPE_ATTR_NXDOMAIN;
+
+		/*
+		 * This is an NXDOMAIN counter, check the RRtype part for the
+		 * expiry value (active, stale, or ancient).
+		 */
+		if ((counter & RDTYPECOUNTER_MAXTYPE) ==
+		    RDTYPECOUNTER_NXDOMAIN_STALE)
+		{
+			attributes |= DNS_RDATASTATSTYPE_ATTR_STALE;
+		} else if ((counter & RDTYPECOUNTER_MAXTYPE) ==
+			   RDTYPECOUNTER_NXDOMAIN_ANCIENT)
+		{
+			attributes |= DNS_RDATASTATSTYPE_ATTR_ANCIENT;
+		}
+	} else {
+		if ((counter & RDTYPECOUNTER_MAXTYPE) == 0) {
+			attributes |= DNS_RDATASTATSTYPE_ATTR_OTHERTYPE;
+		}
+		if ((counter & RDTYPECOUNTER_NXRRSET) != 0) {
+			attributes |= DNS_RDATASTATSTYPE_ATTR_NXRRSET;
+		}
+
+		if ((counter & RDTYPECOUNTER_STALE) != 0) {
+			attributes |= DNS_RDATASTATSTYPE_ATTR_STALE;
+		} else if ((counter & RDTYPECOUNTER_ANCIENT) != 0) {
+			attributes |= DNS_RDATASTATSTYPE_ATTR_ANCIENT;
+		}
+	}
+
+	dump_rdentry(counter, value, attributes, rdatadumparg->fn,
+		     rdatadumparg->arg);
+}
+
+void
+dns_rdatasetstats_dump(dns_stats_t *stats, dns_rdatatypestats_dumper_t dump_fn,
+		       void *arg0, unsigned int options) {
+	rdatadumparg_t arg;
+
+	REQUIRE(DNS_STATS_VALID(stats) &&
+		stats->type == dns_statstype_rdataset);
+
+	arg.fn = dump_fn;
+	arg.arg = arg0;
+	isc_stats_dump(stats->counters, rdataset_dumpcb, &arg, options);
+}
+
+static void
+dnssec_dumpcb(isc_statscounter_t counter, uint64_t value, void *arg) {
+	dnssecsigndumparg_t *dnssecarg = arg;
+
+	dnssecarg->fn((dns_keytag_t)counter, value, dnssecarg->arg);
+}
+
+static void
+dnssec_statsdump(isc_stats_t *stats, dnssecsignstats_type_t operation,
+		 isc_stats_dumper_t dump_fn, void *arg, unsigned int options) {
+	int i, num_keys;
+
+	num_keys = isc_stats_ncounters(stats) / dnssecsign_block_size;
+	for (i = 0; i < num_keys; i++) {
+		int idx = dnssecsign_block_size * i;
+		uint32_t kval, val;
+		dns_keytag_t id;
+
+		kval = isc_stats_get_counter(stats, idx);
+		if (kval == 0) {
+			continue;
+		}
+
+		val = isc_stats_get_counter(stats, (idx + operation));
+		if ((options & ISC_STATSDUMP_VERBOSE) == 0 && val == 0) {
+			continue;
+		}
+
+		id = (dns_keytag_t)kval & DNSSECSIGNSTATS_KEY_ID_MASK;
+
+		dump_fn((isc_statscounter_t)id, val, arg);
+	}
+}
+
+void
+dns_dnssecsignstats_dump(dns_stats_t *stats, dnssecsignstats_type_t operation,
+			 dns_dnssecsignstats_dumper_t dump_fn, void *arg0,
+			 unsigned int options) {
+	dnssecsigndumparg_t arg;
+
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_dnssec);
+
+	arg.fn = dump_fn;
+	arg.arg = arg0;
+
+	dnssec_statsdump(stats->counters, operation, dnssec_dumpcb, &arg,
+			 options);
+}
+
+static void
+opcode_dumpcb(isc_statscounter_t counter, uint64_t value, void *arg) {
+	opcodedumparg_t *opcodearg = arg;
+
+	opcodearg->fn((dns_opcode_t)counter, value, opcodearg->arg);
+}
+
+static void
+rcode_dumpcb(isc_statscounter_t counter, uint64_t value, void *arg) {
+	rcodedumparg_t *rcodearg = arg;
+
+	rcodearg->fn((dns_rcode_t)counter, value, rcodearg->arg);
+}
+
+void
+dns_opcodestats_dump(dns_stats_t *stats, dns_opcodestats_dumper_t dump_fn,
+		     void *arg0, unsigned int options) {
+	opcodedumparg_t arg;
+
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_opcode);
+
+	arg.fn = dump_fn;
+	arg.arg = arg0;
+	isc_stats_dump(stats->counters, opcode_dumpcb, &arg, options);
+}
+
+void
+dns_rcodestats_dump(dns_stats_t *stats, dns_rcodestats_dumper_t dump_fn,
+		    void *arg0, unsigned int options) {
+	rcodedumparg_t arg;
+
+	REQUIRE(DNS_STATS_VALID(stats) && stats->type == dns_statstype_rcode);
+
+	arg.fn = dump_fn;
+	arg.arg = arg0;
+	isc_stats_dump(stats->counters, rcode_dumpcb, &arg, options);
+}
+
+/***
+ *** Obsolete variables and functions follow:
+ ***/
+LIBDNS_EXTERNAL_DATA const char *dns_statscounter_names[DNS_STATS_NCOUNTERS] = {
+	"success",   "referral", "nxrrset",   "nxdomain",
+	"recursion", "failure",	 "duplicate", "dropped"
+};
+
+isc_result_t
+dns_stats_alloccounters(isc_mem_t *mctx, uint64_t **ctrp) {
+	int i;
+	uint64_t *p = isc_mem_get(mctx, DNS_STATS_NCOUNTERS * sizeof(uint64_t));
+	if (p == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+	for (i = 0; i < DNS_STATS_NCOUNTERS; i++) {
+		p[i] = 0;
+	}
+	*ctrp = p;
+	return (ISC_R_SUCCESS);
+}
+
+void
+dns_stats_freecounters(isc_mem_t *mctx, uint64_t **ctrp) {
+	isc_mem_put(mctx, *ctrp, DNS_STATS_NCOUNTERS * sizeof(uint64_t));
+	*ctrp = NULL;
+}