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322345fd LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2014 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include "resolved-dns-cache.h" | |
7e8e0422 | 23 | #include "resolved-dns-packet.h" |
322345fd | 24 | |
cbd4560e | 25 | /* Never cache more than 1K entries */ |
322345fd | 26 | #define CACHE_MAX 1024 |
cbd4560e LP |
27 | |
28 | /* We never keep any item longer than 10min in our cache */ | |
322345fd LP |
29 | #define CACHE_TTL_MAX_USEC (10 * USEC_PER_MINUTE) |
30 | ||
623a4c97 LP |
31 | typedef enum DnsCacheItemType DnsCacheItemType; |
32 | typedef struct DnsCacheItem DnsCacheItem; | |
33 | ||
34 | enum DnsCacheItemType { | |
35 | DNS_CACHE_POSITIVE, | |
36 | DNS_CACHE_NODATA, | |
37 | DNS_CACHE_NXDOMAIN, | |
38 | }; | |
39 | ||
40 | struct DnsCacheItem { | |
41 | DnsResourceKey *key; | |
42 | DnsResourceRecord *rr; | |
43 | usec_t until; | |
44 | DnsCacheItemType type; | |
45 | unsigned prioq_idx; | |
a4076574 LP |
46 | int owner_family; |
47 | union in_addr_union owner_address; | |
623a4c97 LP |
48 | LIST_FIELDS(DnsCacheItem, by_key); |
49 | }; | |
50 | ||
322345fd LP |
51 | static void dns_cache_item_free(DnsCacheItem *i) { |
52 | if (!i) | |
53 | return; | |
54 | ||
55 | dns_resource_record_unref(i->rr); | |
7e8e0422 | 56 | dns_resource_key_unref(i->key); |
322345fd LP |
57 | free(i); |
58 | } | |
59 | ||
60 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsCacheItem*, dns_cache_item_free); | |
61 | ||
62 | static void dns_cache_item_remove_and_free(DnsCache *c, DnsCacheItem *i) { | |
63 | DnsCacheItem *first; | |
64 | ||
65 | assert(c); | |
66 | ||
67 | if (!i) | |
68 | return; | |
69 | ||
7e8e0422 LP |
70 | first = hashmap_get(c->by_key, i->key); |
71 | LIST_REMOVE(by_key, first, i); | |
322345fd LP |
72 | |
73 | if (first) | |
7e8e0422 | 74 | assert_se(hashmap_replace(c->by_key, first->key, first) >= 0); |
322345fd | 75 | else |
7e8e0422 | 76 | hashmap_remove(c->by_key, i->key); |
322345fd | 77 | |
7e8e0422 | 78 | prioq_remove(c->by_expiry, i, &i->prioq_idx); |
322345fd LP |
79 | |
80 | dns_cache_item_free(i); | |
81 | } | |
82 | ||
83 | void dns_cache_flush(DnsCache *c) { | |
84 | DnsCacheItem *i; | |
85 | ||
86 | assert(c); | |
87 | ||
7e8e0422 | 88 | while ((i = hashmap_first(c->by_key))) |
322345fd LP |
89 | dns_cache_item_remove_and_free(c, i); |
90 | ||
7e8e0422 LP |
91 | assert(hashmap_size(c->by_key) == 0); |
92 | assert(prioq_size(c->by_expiry) == 0); | |
322345fd | 93 | |
cab5b059 LP |
94 | c->by_key = hashmap_free(c->by_key); |
95 | c->by_expiry = prioq_free(c->by_expiry); | |
322345fd LP |
96 | } |
97 | ||
6b34a6c9 | 98 | static bool dns_cache_remove(DnsCache *c, DnsResourceKey *key) { |
322345fd | 99 | DnsCacheItem *i; |
6b34a6c9 | 100 | bool exist = false; |
322345fd LP |
101 | |
102 | assert(c); | |
103 | assert(key); | |
104 | ||
6b34a6c9 | 105 | while ((i = hashmap_get(c->by_key, key))) { |
322345fd | 106 | dns_cache_item_remove_and_free(c, i); |
6b34a6c9 TG |
107 | exist = true; |
108 | } | |
109 | ||
110 | return exist; | |
322345fd LP |
111 | } |
112 | ||
113 | static void dns_cache_make_space(DnsCache *c, unsigned add) { | |
114 | assert(c); | |
115 | ||
116 | if (add <= 0) | |
117 | return; | |
118 | ||
119 | /* Makes space for n new entries. Note that we actually allow | |
120 | * the cache to grow beyond CACHE_MAX, but only when we shall | |
121 | * add more RRs to the cache than CACHE_MAX at once. In that | |
122 | * case the cache will be emptied completely otherwise. */ | |
123 | ||
124 | for (;;) { | |
faa133f3 | 125 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
322345fd LP |
126 | DnsCacheItem *i; |
127 | ||
7e8e0422 | 128 | if (prioq_size(c->by_expiry) <= 0) |
322345fd LP |
129 | break; |
130 | ||
7e8e0422 | 131 | if (prioq_size(c->by_expiry) + add < CACHE_MAX) |
322345fd LP |
132 | break; |
133 | ||
7e8e0422 | 134 | i = prioq_peek(c->by_expiry); |
cbd4560e LP |
135 | assert(i); |
136 | ||
faa133f3 | 137 | /* Take an extra reference to the key so that it |
cbd4560e | 138 | * doesn't go away in the middle of the remove call */ |
7e8e0422 | 139 | key = dns_resource_key_ref(i->key); |
faa133f3 | 140 | dns_cache_remove(c, key); |
322345fd LP |
141 | } |
142 | } | |
143 | ||
144 | void dns_cache_prune(DnsCache *c) { | |
145 | usec_t t = 0; | |
146 | ||
147 | assert(c); | |
148 | ||
149 | /* Remove all entries that are past their TTL */ | |
150 | ||
151 | for (;;) { | |
faa133f3 | 152 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
322345fd | 153 | DnsCacheItem *i; |
322345fd | 154 | |
7e8e0422 | 155 | i = prioq_peek(c->by_expiry); |
322345fd LP |
156 | if (!i) |
157 | break; | |
158 | ||
322345fd | 159 | if (t <= 0) |
240b589b | 160 | t = now(clock_boottime_or_monotonic()); |
322345fd | 161 | |
7e8e0422 | 162 | if (i->until > t) |
322345fd LP |
163 | break; |
164 | ||
faa133f3 | 165 | /* Take an extra reference to the key so that it |
cbd4560e | 166 | * doesn't go away in the middle of the remove call */ |
7e8e0422 | 167 | key = dns_resource_key_ref(i->key); |
faa133f3 | 168 | dns_cache_remove(c, key); |
322345fd LP |
169 | } |
170 | } | |
171 | ||
172 | static int dns_cache_item_prioq_compare_func(const void *a, const void *b) { | |
322345fd LP |
173 | const DnsCacheItem *x = a, *y = b; |
174 | ||
7e8e0422 | 175 | if (x->until < y->until) |
322345fd | 176 | return -1; |
7e8e0422 | 177 | if (x->until > y->until) |
322345fd LP |
178 | return 1; |
179 | return 0; | |
180 | } | |
181 | ||
623a4c97 | 182 | static int dns_cache_init(DnsCache *c) { |
7e8e0422 LP |
183 | int r; |
184 | ||
623a4c97 LP |
185 | assert(c); |
186 | ||
7e8e0422 LP |
187 | r = prioq_ensure_allocated(&c->by_expiry, dns_cache_item_prioq_compare_func); |
188 | if (r < 0) | |
189 | return r; | |
190 | ||
d5099efc | 191 | r = hashmap_ensure_allocated(&c->by_key, &dns_resource_key_hash_ops); |
7e8e0422 LP |
192 | if (r < 0) |
193 | return r; | |
194 | ||
195 | return r; | |
196 | } | |
197 | ||
198 | static int dns_cache_link_item(DnsCache *c, DnsCacheItem *i) { | |
199 | DnsCacheItem *first; | |
200 | int r; | |
201 | ||
322345fd LP |
202 | assert(c); |
203 | assert(i); | |
322345fd | 204 | |
7e8e0422 LP |
205 | r = prioq_put(c->by_expiry, i, &i->prioq_idx); |
206 | if (r < 0) | |
207 | return r; | |
322345fd | 208 | |
7e8e0422 LP |
209 | first = hashmap_get(c->by_key, i->key); |
210 | if (first) { | |
211 | LIST_PREPEND(by_key, first, i); | |
212 | assert_se(hashmap_replace(c->by_key, first->key, first) >= 0); | |
213 | } else { | |
214 | r = hashmap_put(c->by_key, i->key, i); | |
215 | if (r < 0) { | |
216 | prioq_remove(c->by_expiry, i, &i->prioq_idx); | |
217 | return r; | |
218 | } | |
322345fd LP |
219 | } |
220 | ||
7e8e0422 | 221 | return 0; |
322345fd LP |
222 | } |
223 | ||
faa133f3 LP |
224 | static DnsCacheItem* dns_cache_get(DnsCache *c, DnsResourceRecord *rr) { |
225 | DnsCacheItem *i; | |
226 | ||
227 | assert(c); | |
228 | assert(rr); | |
229 | ||
7e8e0422 | 230 | LIST_FOREACH(by_key, i, hashmap_get(c->by_key, rr->key)) |
3ef77d04 | 231 | if (i->rr && dns_resource_record_equal(i->rr, rr) > 0) |
faa133f3 LP |
232 | return i; |
233 | ||
234 | return NULL; | |
235 | } | |
236 | ||
7e8e0422 LP |
237 | static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsResourceRecord *rr, usec_t timestamp) { |
238 | assert(c); | |
239 | assert(i); | |
240 | assert(rr); | |
241 | ||
242 | i->type = DNS_CACHE_POSITIVE; | |
243 | ||
244 | if (!i->by_key_prev) { | |
245 | /* We are the first item in the list, we need to | |
246 | * update the key used in the hashmap */ | |
247 | ||
248 | assert_se(hashmap_replace(c->by_key, rr->key, i) >= 0); | |
249 | } | |
250 | ||
251 | dns_resource_record_ref(rr); | |
252 | dns_resource_record_unref(i->rr); | |
253 | i->rr = rr; | |
254 | ||
255 | dns_resource_key_unref(i->key); | |
256 | i->key = dns_resource_key_ref(rr->key); | |
257 | ||
258 | i->until = timestamp + MIN(rr->ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC); | |
259 | ||
260 | prioq_reshuffle(c->by_expiry, i, &i->prioq_idx); | |
261 | } | |
262 | ||
a4076574 LP |
263 | static int dns_cache_put_positive( |
264 | DnsCache *c, | |
265 | DnsResourceRecord *rr, | |
266 | usec_t timestamp, | |
267 | int owner_family, | |
268 | const union in_addr_union *owner_address) { | |
269 | ||
322345fd | 270 | _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL; |
6b34a6c9 | 271 | _cleanup_free_ char *key_str = NULL; |
7e8e0422 | 272 | DnsCacheItem *existing; |
322345fd LP |
273 | int r; |
274 | ||
275 | assert(c); | |
276 | assert(rr); | |
a4076574 | 277 | assert(owner_address); |
322345fd LP |
278 | |
279 | /* New TTL is 0? Delete the entry... */ | |
280 | if (rr->ttl <= 0) { | |
6b34a6c9 TG |
281 | if (dns_cache_remove(c, rr->key)) { |
282 | r = dns_resource_key_to_string(rr->key, &key_str); | |
283 | if (r < 0) | |
284 | return r; | |
285 | ||
286 | log_debug("Removed zero TTL entry from cache: %s", key_str); | |
287 | } | |
288 | ||
322345fd LP |
289 | return 0; |
290 | } | |
291 | ||
ddf16339 LP |
292 | if (rr->key->class == DNS_CLASS_ANY) |
293 | return 0; | |
294 | if (rr->key->type == DNS_TYPE_ANY) | |
295 | return 0; | |
296 | ||
322345fd LP |
297 | /* Entry exists already? Update TTL and timestamp */ |
298 | existing = dns_cache_get(c, rr); | |
299 | if (existing) { | |
7e8e0422 | 300 | dns_cache_item_update_positive(c, existing, rr, timestamp); |
322345fd LP |
301 | return 0; |
302 | } | |
303 | ||
304 | /* Otherwise, add the new RR */ | |
623a4c97 | 305 | r = dns_cache_init(c); |
322345fd LP |
306 | if (r < 0) |
307 | return r; | |
308 | ||
7e8e0422 LP |
309 | dns_cache_make_space(c, 1); |
310 | ||
311 | i = new0(DnsCacheItem, 1); | |
312 | if (!i) | |
313 | return -ENOMEM; | |
314 | ||
315 | i->type = DNS_CACHE_POSITIVE; | |
316 | i->key = dns_resource_key_ref(rr->key); | |
317 | i->rr = dns_resource_record_ref(rr); | |
318 | i->until = timestamp + MIN(i->rr->ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC); | |
319 | i->prioq_idx = PRIOQ_IDX_NULL; | |
a4076574 LP |
320 | i->owner_family = owner_family; |
321 | i->owner_address = *owner_address; | |
7e8e0422 LP |
322 | |
323 | r = dns_cache_link_item(c, i); | |
324 | if (r < 0) | |
325 | return r; | |
326 | ||
6b34a6c9 TG |
327 | r = dns_resource_key_to_string(i->key, &key_str); |
328 | if (r < 0) | |
329 | return r; | |
330 | ||
331 | log_debug("Added cache entry for %s", key_str); | |
332 | ||
7e8e0422 LP |
333 | i = NULL; |
334 | return 0; | |
335 | } | |
336 | ||
a4076574 LP |
337 | static int dns_cache_put_negative( |
338 | DnsCache *c, | |
339 | DnsResourceKey *key, | |
340 | int rcode, | |
341 | usec_t timestamp, | |
342 | uint32_t soa_ttl, | |
343 | int owner_family, | |
344 | const union in_addr_union *owner_address) { | |
345 | ||
7e8e0422 | 346 | _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL; |
6b34a6c9 | 347 | _cleanup_free_ char *key_str = NULL; |
7e8e0422 LP |
348 | int r; |
349 | ||
350 | assert(c); | |
351 | assert(key); | |
a4076574 | 352 | assert(owner_address); |
7e8e0422 LP |
353 | |
354 | dns_cache_remove(c, key); | |
355 | ||
ddf16339 LP |
356 | if (key->class == DNS_CLASS_ANY) |
357 | return 0; | |
358 | if (key->type == DNS_TYPE_ANY) | |
359 | return 0; | |
6b34a6c9 TG |
360 | if (soa_ttl <= 0) { |
361 | r = dns_resource_key_to_string(key, &key_str); | |
362 | if (r < 0) | |
363 | return r; | |
364 | ||
365 | log_debug("Ignored negative cache entry with zero SOA TTL: %s", key_str); | |
366 | ||
95dd6257 | 367 | return 0; |
6b34a6c9 | 368 | } |
ddf16339 | 369 | |
7e8e0422 LP |
370 | if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN)) |
371 | return 0; | |
372 | ||
623a4c97 | 373 | r = dns_cache_init(c); |
322345fd LP |
374 | if (r < 0) |
375 | return r; | |
376 | ||
377 | dns_cache_make_space(c, 1); | |
378 | ||
379 | i = new0(DnsCacheItem, 1); | |
380 | if (!i) | |
381 | return -ENOMEM; | |
382 | ||
7e8e0422 LP |
383 | i->type = rcode == DNS_RCODE_SUCCESS ? DNS_CACHE_NODATA : DNS_CACHE_NXDOMAIN; |
384 | i->key = dns_resource_key_ref(key); | |
385 | i->until = timestamp + MIN(soa_ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC); | |
386 | i->prioq_idx = PRIOQ_IDX_NULL; | |
a4076574 LP |
387 | i->owner_family = owner_family; |
388 | i->owner_address = *owner_address; | |
322345fd | 389 | |
7e8e0422 | 390 | r = dns_cache_link_item(c, i); |
322345fd LP |
391 | if (r < 0) |
392 | return r; | |
393 | ||
6b34a6c9 TG |
394 | r = dns_resource_key_to_string(i->key, &key_str); |
395 | if (r < 0) | |
396 | return r; | |
397 | ||
398 | log_debug("Added %s cache entry for %s", i->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN", key_str); | |
399 | ||
322345fd | 400 | i = NULL; |
322345fd LP |
401 | return 0; |
402 | } | |
403 | ||
a4076574 LP |
404 | int dns_cache_put( |
405 | DnsCache *c, | |
406 | DnsQuestion *q, | |
407 | int rcode, | |
408 | DnsAnswer *answer, | |
409 | unsigned max_rrs, | |
410 | usec_t timestamp, | |
411 | int owner_family, | |
412 | const union in_addr_union *owner_address) { | |
413 | ||
eff91ee0 | 414 | unsigned cache_keys, i; |
322345fd LP |
415 | int r; |
416 | ||
417 | assert(c); | |
322345fd | 418 | |
eff91ee0 DM |
419 | if (q) { |
420 | /* First, if we were passed a question, delete all matching old RRs, | |
421 | * so that we only keep complete by_key in place. */ | |
422 | for (i = 0; i < q->n_keys; i++) | |
423 | dns_cache_remove(c, q->keys[i]); | |
424 | } | |
0ec7c46e LP |
425 | |
426 | if (!answer) | |
427 | return 0; | |
428 | ||
faa133f3 | 429 | for (i = 0; i < answer->n_rrs; i++) |
78c6a153 | 430 | dns_cache_remove(c, answer->items[i].rr->key); |
322345fd | 431 | |
7e8e0422 LP |
432 | /* We only care for positive replies and NXDOMAINs, on all |
433 | * other replies we will simply flush the respective entries, | |
434 | * and that's it */ | |
435 | ||
436 | if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN)) | |
437 | return 0; | |
438 | ||
eff91ee0 DM |
439 | cache_keys = answer->n_rrs; |
440 | ||
441 | if (q) | |
442 | cache_keys += q->n_keys; | |
443 | ||
7e8e0422 | 444 | /* Make some space for our new entries */ |
eff91ee0 | 445 | dns_cache_make_space(c, cache_keys); |
322345fd | 446 | |
7e8e0422 | 447 | if (timestamp <= 0) |
240b589b | 448 | timestamp = now(clock_boottime_or_monotonic()); |
322345fd | 449 | |
7e8e0422 | 450 | /* Second, add in positive entries for all contained RRs */ |
d2f47562 | 451 | for (i = 0; i < MIN(max_rrs, answer->n_rrs); i++) { |
78c6a153 | 452 | r = dns_cache_put_positive(c, answer->items[i].rr, timestamp, owner_family, owner_address); |
7e8e0422 LP |
453 | if (r < 0) |
454 | goto fail; | |
455 | } | |
456 | ||
eff91ee0 DM |
457 | if (!q) |
458 | return 0; | |
459 | ||
7e8e0422 LP |
460 | /* Third, add in negative entries for all keys with no RR */ |
461 | for (i = 0; i < q->n_keys; i++) { | |
462 | DnsResourceRecord *soa = NULL; | |
463 | ||
464 | r = dns_answer_contains(answer, q->keys[i]); | |
465 | if (r < 0) | |
466 | goto fail; | |
467 | if (r > 0) | |
468 | continue; | |
469 | ||
0a18f3e5 LP |
470 | /* See https://tools.ietf.org/html/rfc2308, which |
471 | * say that a matching SOA record in the packet | |
472 | * is used to to enable negative caching. */ | |
473 | ||
7e8e0422 LP |
474 | r = dns_answer_find_soa(answer, q->keys[i], &soa); |
475 | if (r < 0) | |
476 | goto fail; | |
477 | if (r == 0) | |
478 | continue; | |
479 | ||
a4076574 | 480 | r = dns_cache_put_negative(c, q->keys[i], rcode, timestamp, MIN(soa->soa.minimum, soa->ttl), owner_family, owner_address); |
322345fd LP |
481 | if (r < 0) |
482 | goto fail; | |
322345fd LP |
483 | } |
484 | ||
485 | return 0; | |
486 | ||
487 | fail: | |
488 | /* Adding all RRs failed. Let's clean up what we already | |
489 | * added, just in case */ | |
490 | ||
eff91ee0 DM |
491 | if (q) { |
492 | for (i = 0; i < q->n_keys; i++) | |
493 | dns_cache_remove(c, q->keys[i]); | |
494 | } | |
495 | ||
7e8e0422 | 496 | for (i = 0; i < answer->n_rrs; i++) |
78c6a153 | 497 | dns_cache_remove(c, answer->items[i].rr->key); |
322345fd LP |
498 | |
499 | return r; | |
500 | } | |
501 | ||
f52e61da | 502 | int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **ret) { |
faa133f3 | 503 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; |
f52e61da | 504 | unsigned n = 0; |
322345fd | 505 | int r; |
7e8e0422 | 506 | bool nxdomain = false; |
f52e61da LP |
507 | _cleanup_free_ char *key_str = NULL; |
508 | DnsCacheItem *j, *first; | |
322345fd LP |
509 | |
510 | assert(c); | |
f52e61da | 511 | assert(key); |
623a4c97 | 512 | assert(rcode); |
faa133f3 | 513 | assert(ret); |
322345fd | 514 | |
f52e61da LP |
515 | if (key->type == DNS_TYPE_ANY || |
516 | key->class == DNS_CLASS_ANY) { | |
322345fd | 517 | |
f52e61da | 518 | /* If we have ANY lookups we simply refresh */ |
322345fd | 519 | |
f52e61da LP |
520 | r = dns_resource_key_to_string(key, &key_str); |
521 | if (r < 0) | |
522 | return r; | |
6b34a6c9 | 523 | |
f52e61da | 524 | log_debug("Ignoring cache for ANY lookup: %s", key_str); |
6b34a6c9 | 525 | |
f52e61da LP |
526 | *ret = NULL; |
527 | *rcode = DNS_RCODE_SUCCESS; | |
528 | return 0; | |
529 | } | |
6b34a6c9 | 530 | |
f52e61da LP |
531 | first = hashmap_get(c->by_key, key); |
532 | if (!first) { | |
533 | /* If one question cannot be answered we need to refresh */ | |
ddf16339 | 534 | |
f52e61da LP |
535 | r = dns_resource_key_to_string(key, &key_str); |
536 | if (r < 0) | |
537 | return r; | |
6b34a6c9 | 538 | |
f52e61da | 539 | log_debug("Cache miss for %s", key_str); |
6b34a6c9 | 540 | |
f52e61da LP |
541 | *ret = NULL; |
542 | *rcode = DNS_RCODE_SUCCESS; | |
543 | return 0; | |
544 | } | |
6b34a6c9 | 545 | |
f52e61da LP |
546 | LIST_FOREACH(by_key, j, first) { |
547 | if (j->rr) | |
548 | n++; | |
549 | else if (j->type == DNS_CACHE_NXDOMAIN) | |
550 | nxdomain = true; | |
551 | } | |
6b34a6c9 | 552 | |
f52e61da LP |
553 | r = dns_resource_key_to_string(key, &key_str); |
554 | if (r < 0) | |
555 | return r; | |
322345fd | 556 | |
f52e61da LP |
557 | log_debug("%s cache hit for %s", |
558 | nxdomain ? "NXDOMAIN" : | |
559 | n > 0 ? "Positive" : "NODATA", | |
560 | key_str); | |
faa133f3 | 561 | |
7e8e0422 LP |
562 | if (n <= 0) { |
563 | *ret = NULL; | |
564 | *rcode = nxdomain ? DNS_RCODE_NXDOMAIN : DNS_RCODE_SUCCESS; | |
565 | return 1; | |
566 | } | |
faa133f3 LP |
567 | |
568 | answer = dns_answer_new(n); | |
569 | if (!answer) | |
570 | return -ENOMEM; | |
322345fd | 571 | |
f52e61da LP |
572 | LIST_FOREACH(by_key, j, first) { |
573 | if (!j->rr) | |
574 | continue; | |
575 | ||
576 | r = dns_answer_add(answer, j->rr, 0); | |
577 | if (r < 0) | |
578 | return r; | |
322345fd LP |
579 | } |
580 | ||
faa133f3 | 581 | *ret = answer; |
7e8e0422 | 582 | *rcode = DNS_RCODE_SUCCESS; |
faa133f3 LP |
583 | answer = NULL; |
584 | ||
585 | return n; | |
322345fd | 586 | } |
a4076574 LP |
587 | |
588 | int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_family, const union in_addr_union *owner_address) { | |
589 | DnsCacheItem *i, *first; | |
590 | bool same_owner = true; | |
591 | ||
592 | assert(cache); | |
593 | assert(rr); | |
594 | ||
595 | dns_cache_prune(cache); | |
596 | ||
597 | /* See if there's a cache entry for the same key. If there | |
598 | * isn't there's no conflict */ | |
599 | first = hashmap_get(cache->by_key, rr->key); | |
600 | if (!first) | |
601 | return 0; | |
602 | ||
603 | /* See if the RR key is owned by the same owner, if so, there | |
604 | * isn't a conflict either */ | |
605 | LIST_FOREACH(by_key, i, first) { | |
606 | if (i->owner_family != owner_family || | |
607 | !in_addr_equal(owner_family, &i->owner_address, owner_address)) { | |
608 | same_owner = false; | |
609 | break; | |
610 | } | |
611 | } | |
612 | if (same_owner) | |
613 | return 0; | |
614 | ||
615 | /* See if there's the exact same RR in the cache. If yes, then | |
616 | * there's no conflict. */ | |
617 | if (dns_cache_get(cache, rr)) | |
618 | return 0; | |
619 | ||
620 | /* There's a conflict */ | |
621 | return 1; | |
622 | } | |
4d506d6b LP |
623 | |
624 | void dns_cache_dump(DnsCache *cache, FILE *f) { | |
625 | Iterator iterator; | |
626 | DnsCacheItem *i; | |
627 | int r; | |
628 | ||
629 | if (!cache) | |
630 | return; | |
631 | ||
632 | if (!f) | |
633 | f = stdout; | |
634 | ||
635 | HASHMAP_FOREACH(i, cache->by_key, iterator) { | |
636 | DnsCacheItem *j; | |
637 | ||
638 | LIST_FOREACH(by_key, j, i) { | |
639 | _cleanup_free_ char *t = NULL; | |
640 | ||
641 | fputc('\t', f); | |
642 | ||
643 | if (j->rr) { | |
644 | r = dns_resource_record_to_string(j->rr, &t); | |
645 | if (r < 0) { | |
646 | log_oom(); | |
647 | continue; | |
648 | } | |
649 | ||
650 | fputs(t, f); | |
651 | fputc('\n', f); | |
652 | } else { | |
653 | r = dns_resource_key_to_string(j->key, &t); | |
654 | if (r < 0) { | |
655 | log_oom(); | |
656 | continue; | |
657 | } | |
658 | ||
659 | fputs(t, f); | |
660 | fputs(" -- ", f); | |
661 | fputs(j->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN", f); | |
662 | fputc('\n', f); | |
663 | } | |
664 | } | |
665 | } | |
666 | } | |
667 | ||
668 | bool dns_cache_is_empty(DnsCache *cache) { | |
669 | if (!cache) | |
670 | return true; | |
671 | ||
672 | return hashmap_isempty(cache->by_key); | |
673 | } |