xref: /freebsd/contrib/unbound/daemon/stats.c (revision c697fb7f)
1 /*
2  * daemon/stats.c - collect runtime performance indicators.
3  *
4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * This file describes the data structure used to collect runtime performance
40  * numbers. These 'statistics' may be of interest to the operator.
41  */
42 #include "config.h"
43 #ifdef HAVE_TIME_H
44 #include <time.h>
45 #endif
46 #include <sys/time.h>
47 #include <sys/types.h>
48 #include "daemon/stats.h"
49 #include "daemon/worker.h"
50 #include "daemon/daemon.h"
51 #include "services/mesh.h"
52 #include "services/outside_network.h"
53 #include "services/listen_dnsport.h"
54 #include "util/config_file.h"
55 #include "util/tube.h"
56 #include "util/timehist.h"
57 #include "util/net_help.h"
58 #include "validator/validator.h"
59 #include "iterator/iterator.h"
60 #include "sldns/sbuffer.h"
61 #include "services/cache/rrset.h"
62 #include "services/cache/infra.h"
63 #include "services/authzone.h"
64 #include "validator/val_kcache.h"
65 #include "validator/val_neg.h"
66 #ifdef CLIENT_SUBNET
67 #include "edns-subnet/subnetmod.h"
68 #endif
69 #ifdef HAVE_SSL
70 #include <openssl/ssl.h>
71 #endif
72 
73 /** add timers and the values do not overflow or become negative */
74 static void
75 stats_timeval_add(long long* d_sec, long long* d_usec, long long add_sec, long long add_usec)
76 {
77 #ifndef S_SPLINT_S
78 	(*d_sec) += add_sec;
79 	(*d_usec) += add_usec;
80 	if((*d_usec) >= 1000000) {
81 		(*d_usec) -= 1000000;
82 		(*d_sec)++;
83 	}
84 #endif
85 }
86 
87 void server_stats_init(struct ub_server_stats* stats, struct config_file* cfg)
88 {
89 	memset(stats, 0, sizeof(*stats));
90 	stats->extended = cfg->stat_extended;
91 }
92 
93 void server_stats_querymiss(struct ub_server_stats* stats, struct worker* worker)
94 {
95 	stats->num_queries_missed_cache++;
96 	stats->sum_query_list_size += worker->env.mesh->all.count;
97 	if((long long)worker->env.mesh->all.count > stats->max_query_list_size)
98 		stats->max_query_list_size = (long long)worker->env.mesh->all.count;
99 }
100 
101 void server_stats_prefetch(struct ub_server_stats* stats, struct worker* worker)
102 {
103 	stats->num_queries_prefetch++;
104 	/* changes the query list size so account that, like a querymiss */
105 	stats->sum_query_list_size += worker->env.mesh->all.count;
106 	if((long long)worker->env.mesh->all.count > stats->max_query_list_size)
107 		stats->max_query_list_size = (long long)worker->env.mesh->all.count;
108 }
109 
110 void server_stats_log(struct ub_server_stats* stats, struct worker* worker,
111 	int threadnum)
112 {
113 	log_info("server stats for thread %d: %u queries, "
114 		"%u answers from cache, %u recursions, %u prefetch, %u rejected by "
115 		"ip ratelimiting",
116 		threadnum, (unsigned)stats->num_queries,
117 		(unsigned)(stats->num_queries -
118 			stats->num_queries_missed_cache),
119 		(unsigned)stats->num_queries_missed_cache,
120 		(unsigned)stats->num_queries_prefetch,
121 		(unsigned)stats->num_queries_ip_ratelimited);
122 	log_info("server stats for thread %d: requestlist max %u avg %g "
123 		"exceeded %u jostled %u", threadnum,
124 		(unsigned)stats->max_query_list_size,
125 		(stats->num_queries_missed_cache+stats->num_queries_prefetch)?
126 			(double)stats->sum_query_list_size/
127 			(double)(stats->num_queries_missed_cache+
128 			stats->num_queries_prefetch) : 0.0,
129 		(unsigned)worker->env.mesh->stats_dropped,
130 		(unsigned)worker->env.mesh->stats_jostled);
131 }
132 
133 
134 #ifdef CLIENT_SUBNET
135 /** Set the EDNS Subnet stats. */
136 static void
137 set_subnet_stats(struct worker* worker, struct ub_server_stats* svr,
138 	int reset)
139 {
140 	int m = modstack_find(&worker->env.mesh->mods, "subnet");
141 	struct subnet_env* sne;
142 	if(m == -1)
143 		return;
144 	sne = (struct subnet_env*)worker->env.modinfo[m];
145 	if(reset && !worker->env.cfg->stat_cumulative) {
146 		lock_rw_wrlock(&sne->biglock);
147 	} else {
148 		lock_rw_rdlock(&sne->biglock);
149 	}
150 	svr->num_query_subnet = (long long)(sne->num_msg_nocache + sne->num_msg_cache);
151 	svr->num_query_subnet_cache = (long long)sne->num_msg_cache;
152 	if(reset && !worker->env.cfg->stat_cumulative) {
153 		sne->num_msg_cache = 0;
154 		sne->num_msg_nocache = 0;
155 	}
156 	lock_rw_unlock(&sne->biglock);
157 }
158 #endif /* CLIENT_SUBNET */
159 
160 /** Set the neg cache stats. */
161 static void
162 set_neg_cache_stats(struct worker* worker, struct ub_server_stats* svr,
163 	int reset)
164 {
165 	int m = modstack_find(&worker->env.mesh->mods, "validator");
166 	struct val_env* ve;
167 	struct val_neg_cache* neg;
168 	if(m == -1)
169 		return;
170 	ve = (struct val_env*)worker->env.modinfo[m];
171 	if(!ve->neg_cache)
172 		return;
173 	neg = ve->neg_cache;
174 	lock_basic_lock(&neg->lock);
175 	svr->num_neg_cache_noerror = (long long)neg->num_neg_cache_noerror;
176 	svr->num_neg_cache_nxdomain = (long long)neg->num_neg_cache_nxdomain;
177 	if(reset && !worker->env.cfg->stat_cumulative) {
178 		neg->num_neg_cache_noerror = 0;
179 		neg->num_neg_cache_nxdomain = 0;
180 	}
181 	lock_basic_unlock(&neg->lock);
182 }
183 
184 /** get rrsets bogus number from validator */
185 static size_t
186 get_rrset_bogus(struct worker* worker, int reset)
187 {
188 	int m = modstack_find(&worker->env.mesh->mods, "validator");
189 	struct val_env* ve;
190 	size_t r;
191 	if(m == -1)
192 		return 0;
193 	ve = (struct val_env*)worker->env.modinfo[m];
194 	lock_basic_lock(&ve->bogus_lock);
195 	r = ve->num_rrset_bogus;
196 	if(reset && !worker->env.cfg->stat_cumulative)
197 		ve->num_rrset_bogus = 0;
198 	lock_basic_unlock(&ve->bogus_lock);
199 	return r;
200 }
201 
202 /** get number of ratelimited queries from iterator */
203 static size_t
204 get_queries_ratelimit(struct worker* worker, int reset)
205 {
206 	int m = modstack_find(&worker->env.mesh->mods, "iterator");
207 	struct iter_env* ie;
208 	size_t r;
209 	if(m == -1)
210 		return 0;
211 	ie = (struct iter_env*)worker->env.modinfo[m];
212 	lock_basic_lock(&ie->queries_ratelimit_lock);
213 	r = ie->num_queries_ratelimited;
214 	if(reset && !worker->env.cfg->stat_cumulative)
215 		ie->num_queries_ratelimited = 0;
216 	lock_basic_unlock(&ie->queries_ratelimit_lock);
217 	return r;
218 }
219 
220 #ifdef USE_DNSCRYPT
221 /** get the number of shared secret cache miss */
222 static size_t
223 get_dnscrypt_cache_miss(struct worker* worker, int reset)
224 {
225 	size_t r;
226 	struct dnsc_env* de = worker->daemon->dnscenv;
227 	if(!de) return 0;
228 
229 	lock_basic_lock(&de->shared_secrets_cache_lock);
230 	r = de->num_query_dnscrypt_secret_missed_cache;
231 	if(reset && !worker->env.cfg->stat_cumulative)
232 		de->num_query_dnscrypt_secret_missed_cache = 0;
233 	lock_basic_unlock(&de->shared_secrets_cache_lock);
234 	return r;
235 }
236 
237 /** get the number of replayed queries */
238 static size_t
239 get_dnscrypt_replay(struct worker* worker, int reset)
240 {
241 	size_t r;
242 	struct dnsc_env* de = worker->daemon->dnscenv;
243 
244 	lock_basic_lock(&de->nonces_cache_lock);
245 	r = de->num_query_dnscrypt_replay;
246 	if(reset && !worker->env.cfg->stat_cumulative)
247 		de->num_query_dnscrypt_replay = 0;
248 	lock_basic_unlock(&de->nonces_cache_lock);
249 	return r;
250 }
251 #endif /* USE_DNSCRYPT */
252 
253 void
254 server_stats_compile(struct worker* worker, struct ub_stats_info* s, int reset)
255 {
256 	int i;
257 	struct listen_list* lp;
258 
259 	s->svr = worker->stats;
260 	s->mesh_num_states = (long long)worker->env.mesh->all.count;
261 	s->mesh_num_reply_states = (long long)worker->env.mesh->num_reply_states;
262 	s->mesh_jostled = (long long)worker->env.mesh->stats_jostled;
263 	s->mesh_dropped = (long long)worker->env.mesh->stats_dropped;
264 	s->mesh_replies_sent = (long long)worker->env.mesh->replies_sent;
265 	s->mesh_replies_sum_wait_sec = (long long)worker->env.mesh->replies_sum_wait.tv_sec;
266 	s->mesh_replies_sum_wait_usec = (long long)worker->env.mesh->replies_sum_wait.tv_usec;
267 	s->mesh_time_median = timehist_quartile(worker->env.mesh->histogram,
268 		0.50);
269 
270 	/* add in the values from the mesh */
271 	s->svr.ans_secure += (long long)worker->env.mesh->ans_secure;
272 	s->svr.ans_bogus += (long long)worker->env.mesh->ans_bogus;
273 	s->svr.ans_rcode_nodata += (long long)worker->env.mesh->ans_nodata;
274 	for(i=0; i<16; i++)
275 		s->svr.ans_rcode[i] += (long long)worker->env.mesh->ans_rcode[i];
276 	timehist_export(worker->env.mesh->histogram, s->svr.hist,
277 		NUM_BUCKETS_HIST);
278 	/* values from outside network */
279 	s->svr.unwanted_replies = (long long)worker->back->unwanted_replies;
280 	s->svr.qtcp_outgoing = (long long)worker->back->num_tcp_outgoing;
281 
282 	/* get and reset validator rrset bogus number */
283 	s->svr.rrset_bogus = (long long)get_rrset_bogus(worker, reset);
284 
285 	/* get and reset iterator query ratelimit number */
286 	s->svr.queries_ratelimited = (long long)get_queries_ratelimit(worker, reset);
287 
288 	/* get cache sizes */
289 	s->svr.msg_cache_count = (long long)count_slabhash_entries(worker->env.msg_cache);
290 	s->svr.rrset_cache_count = (long long)count_slabhash_entries(&worker->env.rrset_cache->table);
291 	s->svr.infra_cache_count = (long long)count_slabhash_entries(worker->env.infra_cache->hosts);
292 	if(worker->env.key_cache)
293 		s->svr.key_cache_count = (long long)count_slabhash_entries(worker->env.key_cache->slab);
294 	else	s->svr.key_cache_count = 0;
295 
296 #ifdef USE_DNSCRYPT
297 	if(worker->daemon->dnscenv) {
298 		s->svr.num_query_dnscrypt_secret_missed_cache =
299 			(long long)get_dnscrypt_cache_miss(worker, reset);
300 		s->svr.shared_secret_cache_count = (long long)count_slabhash_entries(
301 			worker->daemon->dnscenv->shared_secrets_cache);
302 		s->svr.nonce_cache_count = (long long)count_slabhash_entries(
303 			worker->daemon->dnscenv->nonces_cache);
304 		s->svr.num_query_dnscrypt_replay =
305 			(long long)get_dnscrypt_replay(worker, reset);
306 	} else {
307 		s->svr.num_query_dnscrypt_secret_missed_cache = 0;
308 		s->svr.shared_secret_cache_count = 0;
309 		s->svr.nonce_cache_count = 0;
310 		s->svr.num_query_dnscrypt_replay = 0;
311 	}
312 #else
313 	s->svr.num_query_dnscrypt_secret_missed_cache = 0;
314 	s->svr.shared_secret_cache_count = 0;
315 	s->svr.nonce_cache_count = 0;
316 	s->svr.num_query_dnscrypt_replay = 0;
317 #endif /* USE_DNSCRYPT */
318 	if(worker->env.auth_zones) {
319 		if(reset && !worker->env.cfg->stat_cumulative) {
320 			lock_rw_wrlock(&worker->env.auth_zones->lock);
321 		} else {
322 			lock_rw_rdlock(&worker->env.auth_zones->lock);
323 		}
324 		s->svr.num_query_authzone_up = (long long)worker->env.
325 			auth_zones->num_query_up;
326 		s->svr.num_query_authzone_down = (long long)worker->env.
327 			auth_zones->num_query_down;
328 		if(reset && !worker->env.cfg->stat_cumulative) {
329 			worker->env.auth_zones->num_query_up = 0;
330 			worker->env.auth_zones->num_query_down = 0;
331 		}
332 		lock_rw_unlock(&worker->env.auth_zones->lock);
333 	}
334 	s->svr.mem_stream_wait =
335 		(long long)tcp_req_info_get_stream_buffer_size();
336 
337 	/* Set neg cache usage numbers */
338 	set_neg_cache_stats(worker, &s->svr, reset);
339 #ifdef CLIENT_SUBNET
340 	/* EDNS Subnet usage numbers */
341 	set_subnet_stats(worker, &s->svr, reset);
342 #else
343 	s->svr.num_query_subnet = 0;
344 	s->svr.num_query_subnet_cache = 0;
345 #endif
346 
347 	/* get tcp accept usage */
348 	s->svr.tcp_accept_usage = 0;
349 	for(lp = worker->front->cps; lp; lp = lp->next) {
350 		if(lp->com->type == comm_tcp_accept)
351 			s->svr.tcp_accept_usage += (long long)lp->com->cur_tcp_count;
352 	}
353 
354 	if(reset && !worker->env.cfg->stat_cumulative) {
355 		worker_stats_clear(worker);
356 	}
357 }
358 
359 void server_stats_obtain(struct worker* worker, struct worker* who,
360 	struct ub_stats_info* s, int reset)
361 {
362 	uint8_t *reply = NULL;
363 	uint32_t len = 0;
364 	if(worker == who) {
365 		/* just fill it in */
366 		server_stats_compile(worker, s, reset);
367 		return;
368 	}
369 	/* communicate over tube */
370 	verbose(VERB_ALGO, "write stats cmd");
371 	if(reset)
372 		worker_send_cmd(who, worker_cmd_stats);
373 	else 	worker_send_cmd(who, worker_cmd_stats_noreset);
374 	verbose(VERB_ALGO, "wait for stats reply");
375 	if(!tube_read_msg(worker->cmd, &reply, &len, 0))
376 		fatal_exit("failed to read stats over cmd channel");
377 	if(len != (uint32_t)sizeof(*s))
378 		fatal_exit("stats on cmd channel wrong length %d %d",
379 			(int)len, (int)sizeof(*s));
380 	memcpy(s, reply, (size_t)len);
381 	free(reply);
382 }
383 
384 void server_stats_reply(struct worker* worker, int reset)
385 {
386 	struct ub_stats_info s;
387 	server_stats_compile(worker, &s, reset);
388 	verbose(VERB_ALGO, "write stats replymsg");
389 	if(!tube_write_msg(worker->daemon->workers[0]->cmd,
390 		(uint8_t*)&s, sizeof(s), 0))
391 		fatal_exit("could not write stat values over cmd channel");
392 }
393 
394 void server_stats_add(struct ub_stats_info* total, struct ub_stats_info* a)
395 {
396 	total->svr.num_queries += a->svr.num_queries;
397 	total->svr.num_queries_ip_ratelimited += a->svr.num_queries_ip_ratelimited;
398 	total->svr.num_queries_missed_cache += a->svr.num_queries_missed_cache;
399 	total->svr.num_queries_prefetch += a->svr.num_queries_prefetch;
400 	total->svr.sum_query_list_size += a->svr.sum_query_list_size;
401 #ifdef USE_DNSCRYPT
402 	total->svr.num_query_dnscrypt_crypted += a->svr.num_query_dnscrypt_crypted;
403 	total->svr.num_query_dnscrypt_cert += a->svr.num_query_dnscrypt_cert;
404 	total->svr.num_query_dnscrypt_cleartext += \
405 		a->svr.num_query_dnscrypt_cleartext;
406 	total->svr.num_query_dnscrypt_crypted_malformed += \
407 		a->svr.num_query_dnscrypt_crypted_malformed;
408 #endif /* USE_DNSCRYPT */
409 	/* the max size reached is upped to higher of both */
410 	if(a->svr.max_query_list_size > total->svr.max_query_list_size)
411 		total->svr.max_query_list_size = a->svr.max_query_list_size;
412 
413 	if(a->svr.extended) {
414 		int i;
415 		total->svr.qtype_big += a->svr.qtype_big;
416 		total->svr.qclass_big += a->svr.qclass_big;
417 		total->svr.qtcp += a->svr.qtcp;
418 		total->svr.qtcp_outgoing += a->svr.qtcp_outgoing;
419 		total->svr.qtls += a->svr.qtls;
420 		total->svr.qtls_resume += a->svr.qtls_resume;
421 		total->svr.qipv6 += a->svr.qipv6;
422 		total->svr.qbit_QR += a->svr.qbit_QR;
423 		total->svr.qbit_AA += a->svr.qbit_AA;
424 		total->svr.qbit_TC += a->svr.qbit_TC;
425 		total->svr.qbit_RD += a->svr.qbit_RD;
426 		total->svr.qbit_RA += a->svr.qbit_RA;
427 		total->svr.qbit_Z += a->svr.qbit_Z;
428 		total->svr.qbit_AD += a->svr.qbit_AD;
429 		total->svr.qbit_CD += a->svr.qbit_CD;
430 		total->svr.qEDNS += a->svr.qEDNS;
431 		total->svr.qEDNS_DO += a->svr.qEDNS_DO;
432 		total->svr.ans_rcode_nodata += a->svr.ans_rcode_nodata;
433 		total->svr.zero_ttl_responses += a->svr.zero_ttl_responses;
434 		total->svr.ans_secure += a->svr.ans_secure;
435 		total->svr.ans_bogus += a->svr.ans_bogus;
436 		total->svr.unwanted_replies += a->svr.unwanted_replies;
437 		total->svr.unwanted_queries += a->svr.unwanted_queries;
438 		total->svr.tcp_accept_usage += a->svr.tcp_accept_usage;
439 		for(i=0; i<UB_STATS_QTYPE_NUM; i++)
440 			total->svr.qtype[i] += a->svr.qtype[i];
441 		for(i=0; i<UB_STATS_QCLASS_NUM; i++)
442 			total->svr.qclass[i] += a->svr.qclass[i];
443 		for(i=0; i<UB_STATS_OPCODE_NUM; i++)
444 			total->svr.qopcode[i] += a->svr.qopcode[i];
445 		for(i=0; i<UB_STATS_RCODE_NUM; i++)
446 			total->svr.ans_rcode[i] += a->svr.ans_rcode[i];
447 		for(i=0; i<NUM_BUCKETS_HIST; i++)
448 			total->svr.hist[i] += a->svr.hist[i];
449 	}
450 
451 	total->mesh_num_states += a->mesh_num_states;
452 	total->mesh_num_reply_states += a->mesh_num_reply_states;
453 	total->mesh_jostled += a->mesh_jostled;
454 	total->mesh_dropped += a->mesh_dropped;
455 	total->mesh_replies_sent += a->mesh_replies_sent;
456 	stats_timeval_add(&total->mesh_replies_sum_wait_sec, &total->mesh_replies_sum_wait_usec, a->mesh_replies_sum_wait_sec, a->mesh_replies_sum_wait_usec);
457 	/* the medians are averaged together, this is not as accurate as
458 	 * taking the median over all of the data, but is good and fast
459 	 * added up here, division later*/
460 	total->mesh_time_median += a->mesh_time_median;
461 }
462 
463 void server_stats_insquery(struct ub_server_stats* stats, struct comm_point* c,
464 	uint16_t qtype, uint16_t qclass, struct edns_data* edns,
465 	struct comm_reply* repinfo)
466 {
467 	uint16_t flags = sldns_buffer_read_u16_at(c->buffer, 2);
468 	if(qtype < UB_STATS_QTYPE_NUM)
469 		stats->qtype[qtype]++;
470 	else	stats->qtype_big++;
471 	if(qclass < UB_STATS_QCLASS_NUM)
472 		stats->qclass[qclass]++;
473 	else	stats->qclass_big++;
474 	stats->qopcode[ LDNS_OPCODE_WIRE(sldns_buffer_begin(c->buffer)) ]++;
475 	if(c->type != comm_udp) {
476 		stats->qtcp++;
477 		if(c->ssl != NULL) {
478 			stats->qtls++;
479 #ifdef HAVE_SSL
480 			if(SSL_session_reused(c->ssl))
481 				stats->qtls_resume++;
482 #endif
483 		}
484 	}
485 	if(repinfo && addr_is_ip6(&repinfo->addr, repinfo->addrlen))
486 		stats->qipv6++;
487 	if( (flags&BIT_QR) )
488 		stats->qbit_QR++;
489 	if( (flags&BIT_AA) )
490 		stats->qbit_AA++;
491 	if( (flags&BIT_TC) )
492 		stats->qbit_TC++;
493 	if( (flags&BIT_RD) )
494 		stats->qbit_RD++;
495 	if( (flags&BIT_RA) )
496 		stats->qbit_RA++;
497 	if( (flags&BIT_Z) )
498 		stats->qbit_Z++;
499 	if( (flags&BIT_AD) )
500 		stats->qbit_AD++;
501 	if( (flags&BIT_CD) )
502 		stats->qbit_CD++;
503 	if(edns->edns_present) {
504 		stats->qEDNS++;
505 		if( (edns->bits & EDNS_DO) )
506 			stats->qEDNS_DO++;
507 	}
508 }
509 
510 void server_stats_insrcode(struct ub_server_stats* stats, sldns_buffer* buf)
511 {
512 	if(stats->extended && sldns_buffer_limit(buf) != 0) {
513 		int r = (int)LDNS_RCODE_WIRE( sldns_buffer_begin(buf) );
514 		stats->ans_rcode[r] ++;
515 		if(r == 0 && LDNS_ANCOUNT( sldns_buffer_begin(buf) ) == 0)
516 			stats->ans_rcode_nodata ++;
517 	}
518 }
519