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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
322345fd | 2 | |
202b76ae ZJS |
3 | #include <net/if.h> |
4 | ||
5 | #include "af-list.h" | |
b5efdb8a | 6 | #include "alloc-util.h" |
58db254a | 7 | #include "dns-domain.h" |
02c2857b | 8 | #include "resolved-dns-answer.h" |
322345fd | 9 | #include "resolved-dns-cache.h" |
7e8e0422 | 10 | #include "resolved-dns-packet.h" |
58db254a | 11 | #include "string-util.h" |
322345fd | 12 | |
6af47493 LP |
13 | /* Never cache more than 4K entries. RFC 1536, Section 5 suggests to |
14 | * leave DNS caches unbounded, but that's crazy. */ | |
d98e5504 | 15 | #define CACHE_MAX 4096 |
cbd4560e | 16 | |
d98e5504 LP |
17 | /* We never keep any item longer than 2h in our cache */ |
18 | #define CACHE_TTL_MAX_USEC (2 * USEC_PER_HOUR) | |
322345fd | 19 | |
201d9958 LP |
20 | /* How long to cache strange rcodes, i.e. rcodes != SUCCESS and != NXDOMAIN (specifically: that's only SERVFAIL for |
21 | * now) */ | |
22 | #define CACHE_TTL_STRANGE_RCODE_USEC (30 * USEC_PER_SEC) | |
23 | ||
623a4c97 LP |
24 | typedef enum DnsCacheItemType DnsCacheItemType; |
25 | typedef struct DnsCacheItem DnsCacheItem; | |
26 | ||
27 | enum DnsCacheItemType { | |
28 | DNS_CACHE_POSITIVE, | |
29 | DNS_CACHE_NODATA, | |
30 | DNS_CACHE_NXDOMAIN, | |
201d9958 | 31 | DNS_CACHE_RCODE, /* "strange" RCODE (effective only SERVFAIL for now) */ |
623a4c97 LP |
32 | }; |
33 | ||
34 | struct DnsCacheItem { | |
d2579eec | 35 | DnsCacheItemType type; |
623a4c97 LP |
36 | DnsResourceKey *key; |
37 | DnsResourceRecord *rr; | |
201d9958 | 38 | int rcode; |
d2579eec | 39 | |
623a4c97 | 40 | usec_t until; |
d2579eec LP |
41 | bool authenticated:1; |
42 | bool shared_owner:1; | |
43 | ||
06d12754 | 44 | int ifindex; |
a4076574 LP |
45 | int owner_family; |
46 | union in_addr_union owner_address; | |
d2579eec LP |
47 | |
48 | unsigned prioq_idx; | |
623a4c97 LP |
49 | LIST_FIELDS(DnsCacheItem, by_key); |
50 | }; | |
51 | ||
201d9958 LP |
52 | static const char *dns_cache_item_type_to_string(DnsCacheItem *item) { |
53 | assert(item); | |
54 | ||
55 | switch (item->type) { | |
56 | ||
57 | case DNS_CACHE_POSITIVE: | |
58 | return "POSITIVE"; | |
59 | ||
60 | case DNS_CACHE_NODATA: | |
61 | return "NODATA"; | |
62 | ||
63 | case DNS_CACHE_NXDOMAIN: | |
64 | return "NXDOMAIN"; | |
65 | ||
66 | case DNS_CACHE_RCODE: | |
67 | return dns_rcode_to_string(item->rcode); | |
68 | } | |
69 | ||
70 | return NULL; | |
71 | } | |
72 | ||
322345fd LP |
73 | static void dns_cache_item_free(DnsCacheItem *i) { |
74 | if (!i) | |
75 | return; | |
76 | ||
77 | dns_resource_record_unref(i->rr); | |
7e8e0422 | 78 | dns_resource_key_unref(i->key); |
322345fd LP |
79 | free(i); |
80 | } | |
81 | ||
82 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsCacheItem*, dns_cache_item_free); | |
83 | ||
39963f11 | 84 | static void dns_cache_item_unlink_and_free(DnsCache *c, DnsCacheItem *i) { |
322345fd LP |
85 | DnsCacheItem *first; |
86 | ||
87 | assert(c); | |
88 | ||
89 | if (!i) | |
90 | return; | |
91 | ||
7e8e0422 LP |
92 | first = hashmap_get(c->by_key, i->key); |
93 | LIST_REMOVE(by_key, first, i); | |
322345fd LP |
94 | |
95 | if (first) | |
7e8e0422 | 96 | assert_se(hashmap_replace(c->by_key, first->key, first) >= 0); |
322345fd | 97 | else |
7e8e0422 | 98 | hashmap_remove(c->by_key, i->key); |
322345fd | 99 | |
7e8e0422 | 100 | prioq_remove(c->by_expiry, i, &i->prioq_idx); |
322345fd LP |
101 | |
102 | dns_cache_item_free(i); | |
103 | } | |
104 | ||
f5bdeb01 LP |
105 | static bool dns_cache_remove_by_rr(DnsCache *c, DnsResourceRecord *rr) { |
106 | DnsCacheItem *first, *i; | |
107 | int r; | |
108 | ||
109 | first = hashmap_get(c->by_key, rr->key); | |
110 | LIST_FOREACH(by_key, i, first) { | |
111 | r = dns_resource_record_equal(i->rr, rr); | |
112 | if (r < 0) | |
113 | return r; | |
114 | if (r > 0) { | |
39963f11 | 115 | dns_cache_item_unlink_and_free(c, i); |
f5bdeb01 LP |
116 | return true; |
117 | } | |
118 | } | |
119 | ||
120 | return false; | |
121 | } | |
122 | ||
2dda578f | 123 | static bool dns_cache_remove_by_key(DnsCache *c, DnsResourceKey *key) { |
1f97052f | 124 | DnsCacheItem *first, *i, *n; |
322345fd LP |
125 | |
126 | assert(c); | |
127 | assert(key); | |
128 | ||
1f97052f LP |
129 | first = hashmap_remove(c->by_key, key); |
130 | if (!first) | |
131 | return false; | |
132 | ||
133 | LIST_FOREACH_SAFE(by_key, i, n, first) { | |
134 | prioq_remove(c->by_expiry, i, &i->prioq_idx); | |
135 | dns_cache_item_free(i); | |
6b34a6c9 TG |
136 | } |
137 | ||
1f97052f | 138 | return true; |
322345fd LP |
139 | } |
140 | ||
ef9a3e3c LP |
141 | void dns_cache_flush(DnsCache *c) { |
142 | DnsResourceKey *key; | |
143 | ||
144 | assert(c); | |
145 | ||
146 | while ((key = hashmap_first_key(c->by_key))) | |
2dda578f | 147 | dns_cache_remove_by_key(c, key); |
ef9a3e3c LP |
148 | |
149 | assert(hashmap_size(c->by_key) == 0); | |
150 | assert(prioq_size(c->by_expiry) == 0); | |
151 | ||
152 | c->by_key = hashmap_free(c->by_key); | |
153 | c->by_expiry = prioq_free(c->by_expiry); | |
154 | } | |
155 | ||
322345fd LP |
156 | static void dns_cache_make_space(DnsCache *c, unsigned add) { |
157 | assert(c); | |
158 | ||
159 | if (add <= 0) | |
160 | return; | |
161 | ||
162 | /* Makes space for n new entries. Note that we actually allow | |
163 | * the cache to grow beyond CACHE_MAX, but only when we shall | |
164 | * add more RRs to the cache than CACHE_MAX at once. In that | |
165 | * case the cache will be emptied completely otherwise. */ | |
166 | ||
167 | for (;;) { | |
faa133f3 | 168 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
322345fd LP |
169 | DnsCacheItem *i; |
170 | ||
7e8e0422 | 171 | if (prioq_size(c->by_expiry) <= 0) |
322345fd LP |
172 | break; |
173 | ||
7e8e0422 | 174 | if (prioq_size(c->by_expiry) + add < CACHE_MAX) |
322345fd LP |
175 | break; |
176 | ||
7e8e0422 | 177 | i = prioq_peek(c->by_expiry); |
cbd4560e LP |
178 | assert(i); |
179 | ||
faa133f3 | 180 | /* Take an extra reference to the key so that it |
cbd4560e | 181 | * doesn't go away in the middle of the remove call */ |
7e8e0422 | 182 | key = dns_resource_key_ref(i->key); |
2dda578f | 183 | dns_cache_remove_by_key(c, key); |
322345fd LP |
184 | } |
185 | } | |
186 | ||
187 | void dns_cache_prune(DnsCache *c) { | |
188 | usec_t t = 0; | |
189 | ||
190 | assert(c); | |
191 | ||
192 | /* Remove all entries that are past their TTL */ | |
193 | ||
194 | for (;;) { | |
195 | DnsCacheItem *i; | |
202b76ae | 196 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
322345fd | 197 | |
7e8e0422 | 198 | i = prioq_peek(c->by_expiry); |
322345fd LP |
199 | if (!i) |
200 | break; | |
201 | ||
322345fd | 202 | if (t <= 0) |
240b589b | 203 | t = now(clock_boottime_or_monotonic()); |
322345fd | 204 | |
7e8e0422 | 205 | if (i->until > t) |
322345fd LP |
206 | break; |
207 | ||
d2579eec | 208 | /* Depending whether this is an mDNS shared entry |
202b76ae ZJS |
209 | * either remove only this one RR or the whole RRset */ |
210 | log_debug("Removing %scache entry for %s (expired "USEC_FMT"s ago)", | |
211 | i->shared_owner ? "shared " : "", | |
212 | dns_resource_key_to_string(i->key, key_str, sizeof key_str), | |
213 | (t - i->until) / USEC_PER_SEC); | |
214 | ||
d2579eec | 215 | if (i->shared_owner) |
39963f11 | 216 | dns_cache_item_unlink_and_free(c, i); |
d2579eec LP |
217 | else { |
218 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
219 | ||
220 | /* Take an extra reference to the key so that it | |
221 | * doesn't go away in the middle of the remove call */ | |
222 | key = dns_resource_key_ref(i->key); | |
2dda578f | 223 | dns_cache_remove_by_key(c, key); |
d2579eec | 224 | } |
322345fd LP |
225 | } |
226 | } | |
227 | ||
228 | static int dns_cache_item_prioq_compare_func(const void *a, const void *b) { | |
322345fd LP |
229 | const DnsCacheItem *x = a, *y = b; |
230 | ||
a0edd02e | 231 | return CMP(x->until, y->until); |
322345fd LP |
232 | } |
233 | ||
623a4c97 | 234 | static int dns_cache_init(DnsCache *c) { |
7e8e0422 LP |
235 | int r; |
236 | ||
623a4c97 LP |
237 | assert(c); |
238 | ||
7e8e0422 LP |
239 | r = prioq_ensure_allocated(&c->by_expiry, dns_cache_item_prioq_compare_func); |
240 | if (r < 0) | |
241 | return r; | |
242 | ||
d5099efc | 243 | r = hashmap_ensure_allocated(&c->by_key, &dns_resource_key_hash_ops); |
7e8e0422 LP |
244 | if (r < 0) |
245 | return r; | |
246 | ||
247 | return r; | |
248 | } | |
249 | ||
250 | static int dns_cache_link_item(DnsCache *c, DnsCacheItem *i) { | |
251 | DnsCacheItem *first; | |
252 | int r; | |
253 | ||
322345fd LP |
254 | assert(c); |
255 | assert(i); | |
322345fd | 256 | |
7e8e0422 LP |
257 | r = prioq_put(c->by_expiry, i, &i->prioq_idx); |
258 | if (r < 0) | |
259 | return r; | |
322345fd | 260 | |
7e8e0422 LP |
261 | first = hashmap_get(c->by_key, i->key); |
262 | if (first) { | |
f57e3cd5 LP |
263 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; |
264 | ||
265 | /* Keep a reference to the original key, while we manipulate the list. */ | |
266 | k = dns_resource_key_ref(first->key); | |
267 | ||
268 | /* Now, try to reduce the number of keys we keep */ | |
269 | dns_resource_key_reduce(&first->key, &i->key); | |
270 | ||
271 | if (first->rr) | |
272 | dns_resource_key_reduce(&first->rr->key, &i->key); | |
273 | if (i->rr) | |
274 | dns_resource_key_reduce(&i->rr->key, &i->key); | |
275 | ||
7e8e0422 LP |
276 | LIST_PREPEND(by_key, first, i); |
277 | assert_se(hashmap_replace(c->by_key, first->key, first) >= 0); | |
278 | } else { | |
279 | r = hashmap_put(c->by_key, i->key, i); | |
280 | if (r < 0) { | |
281 | prioq_remove(c->by_expiry, i, &i->prioq_idx); | |
282 | return r; | |
283 | } | |
322345fd LP |
284 | } |
285 | ||
7e8e0422 | 286 | return 0; |
322345fd LP |
287 | } |
288 | ||
faa133f3 LP |
289 | static DnsCacheItem* dns_cache_get(DnsCache *c, DnsResourceRecord *rr) { |
290 | DnsCacheItem *i; | |
291 | ||
292 | assert(c); | |
293 | assert(rr); | |
294 | ||
7e8e0422 | 295 | LIST_FOREACH(by_key, i, hashmap_get(c->by_key, rr->key)) |
3ef77d04 | 296 | if (i->rr && dns_resource_record_equal(i->rr, rr) > 0) |
faa133f3 LP |
297 | return i; |
298 | ||
299 | return NULL; | |
300 | } | |
301 | ||
d3760be0 | 302 | static usec_t calculate_until(DnsResourceRecord *rr, uint32_t nsec_ttl, usec_t timestamp, bool use_soa_minimum) { |
b211dc7e LP |
303 | uint32_t ttl; |
304 | usec_t u; | |
ee3d6aff LP |
305 | |
306 | assert(rr); | |
307 | ||
d3760be0 | 308 | ttl = MIN(rr->ttl, nsec_ttl); |
b211dc7e LP |
309 | if (rr->key->type == DNS_TYPE_SOA && use_soa_minimum) { |
310 | /* If this is a SOA RR, and it is requested, clamp to | |
311 | * the SOA's minimum field. This is used when we do | |
312 | * negative caching, to determine the TTL for the | |
313 | * negative caching entry. See RFC 2308, Section | |
314 | * 5. */ | |
ee3d6aff | 315 | |
b211dc7e LP |
316 | if (ttl > rr->soa.minimum) |
317 | ttl = rr->soa.minimum; | |
318 | } | |
319 | ||
320 | u = ttl * USEC_PER_SEC; | |
321 | if (u > CACHE_TTL_MAX_USEC) | |
322 | u = CACHE_TTL_MAX_USEC; | |
ee3d6aff LP |
323 | |
324 | if (rr->expiry != USEC_INFINITY) { | |
325 | usec_t left; | |
326 | ||
b211dc7e LP |
327 | /* Make use of the DNSSEC RRSIG expiry info, if we |
328 | * have it */ | |
ee3d6aff LP |
329 | |
330 | left = LESS_BY(rr->expiry, now(CLOCK_REALTIME)); | |
b211dc7e LP |
331 | if (u > left) |
332 | u = left; | |
ee3d6aff LP |
333 | } |
334 | ||
b211dc7e | 335 | return timestamp + u; |
ee3d6aff LP |
336 | } |
337 | ||
d2579eec LP |
338 | static void dns_cache_item_update_positive( |
339 | DnsCache *c, | |
340 | DnsCacheItem *i, | |
341 | DnsResourceRecord *rr, | |
342 | bool authenticated, | |
343 | bool shared_owner, | |
344 | usec_t timestamp, | |
06d12754 | 345 | int ifindex, |
d2579eec LP |
346 | int owner_family, |
347 | const union in_addr_union *owner_address) { | |
348 | ||
7e8e0422 LP |
349 | assert(c); |
350 | assert(i); | |
351 | assert(rr); | |
d2579eec | 352 | assert(owner_address); |
7e8e0422 LP |
353 | |
354 | i->type = DNS_CACHE_POSITIVE; | |
355 | ||
ece174c5 | 356 | if (!i->by_key_prev) |
7e8e0422 LP |
357 | /* We are the first item in the list, we need to |
358 | * update the key used in the hashmap */ | |
359 | ||
360 | assert_se(hashmap_replace(c->by_key, rr->key, i) >= 0); | |
7e8e0422 LP |
361 | |
362 | dns_resource_record_ref(rr); | |
363 | dns_resource_record_unref(i->rr); | |
364 | i->rr = rr; | |
365 | ||
366 | dns_resource_key_unref(i->key); | |
367 | i->key = dns_resource_key_ref(rr->key); | |
368 | ||
d3760be0 | 369 | i->until = calculate_until(rr, (uint32_t) -1, timestamp, false); |
d2579eec LP |
370 | i->authenticated = authenticated; |
371 | i->shared_owner = shared_owner; | |
372 | ||
06d12754 LP |
373 | i->ifindex = ifindex; |
374 | ||
d2579eec LP |
375 | i->owner_family = owner_family; |
376 | i->owner_address = *owner_address; | |
7e8e0422 LP |
377 | |
378 | prioq_reshuffle(c->by_expiry, i, &i->prioq_idx); | |
379 | } | |
380 | ||
a4076574 LP |
381 | static int dns_cache_put_positive( |
382 | DnsCache *c, | |
383 | DnsResourceRecord *rr, | |
931851e8 | 384 | bool authenticated, |
d2579eec | 385 | bool shared_owner, |
a4076574 | 386 | usec_t timestamp, |
06d12754 | 387 | int ifindex, |
a4076574 LP |
388 | int owner_family, |
389 | const union in_addr_union *owner_address) { | |
390 | ||
322345fd | 391 | _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL; |
7e8e0422 | 392 | DnsCacheItem *existing; |
202b76ae | 393 | char key_str[DNS_RESOURCE_KEY_STRING_MAX], ifname[IF_NAMESIZE]; |
a257f9d4 | 394 | int r, k; |
322345fd LP |
395 | |
396 | assert(c); | |
397 | assert(rr); | |
a4076574 | 398 | assert(owner_address); |
322345fd | 399 | |
222148b6 LP |
400 | /* Never cache pseudo RRs */ |
401 | if (dns_class_is_pseudo(rr->key->class)) | |
402 | return 0; | |
403 | if (dns_type_is_pseudo(rr->key->type)) | |
404 | return 0; | |
405 | ||
f5bdeb01 | 406 | /* New TTL is 0? Delete this specific entry... */ |
322345fd | 407 | if (rr->ttl <= 0) { |
f5bdeb01 | 408 | k = dns_cache_remove_by_rr(c, rr); |
202b76ae ZJS |
409 | log_debug("%s: %s", |
410 | k > 0 ? "Removed zero TTL entry from cache" : "Not caching zero TTL cache entry", | |
18665d1f | 411 | dns_resource_key_to_string(rr->key, key_str, sizeof key_str)); |
322345fd LP |
412 | return 0; |
413 | } | |
414 | ||
13e785f7 | 415 | /* Entry exists already? Update TTL, timestamp and owner */ |
322345fd LP |
416 | existing = dns_cache_get(c, rr); |
417 | if (existing) { | |
d2579eec LP |
418 | dns_cache_item_update_positive( |
419 | c, | |
420 | existing, | |
421 | rr, | |
422 | authenticated, | |
423 | shared_owner, | |
424 | timestamp, | |
06d12754 | 425 | ifindex, |
d2579eec LP |
426 | owner_family, |
427 | owner_address); | |
322345fd LP |
428 | return 0; |
429 | } | |
430 | ||
431 | /* Otherwise, add the new RR */ | |
623a4c97 | 432 | r = dns_cache_init(c); |
322345fd LP |
433 | if (r < 0) |
434 | return r; | |
435 | ||
7e8e0422 LP |
436 | dns_cache_make_space(c, 1); |
437 | ||
438 | i = new0(DnsCacheItem, 1); | |
439 | if (!i) | |
440 | return -ENOMEM; | |
441 | ||
442 | i->type = DNS_CACHE_POSITIVE; | |
443 | i->key = dns_resource_key_ref(rr->key); | |
444 | i->rr = dns_resource_record_ref(rr); | |
d3760be0 | 445 | i->until = calculate_until(rr, (uint32_t) -1, timestamp, false); |
d2579eec LP |
446 | i->authenticated = authenticated; |
447 | i->shared_owner = shared_owner; | |
06d12754 | 448 | i->ifindex = ifindex; |
a4076574 LP |
449 | i->owner_family = owner_family; |
450 | i->owner_address = *owner_address; | |
d2579eec | 451 | i->prioq_idx = PRIOQ_IDX_NULL; |
7e8e0422 LP |
452 | |
453 | r = dns_cache_link_item(c, i); | |
454 | if (r < 0) | |
455 | return r; | |
456 | ||
f1d34068 | 457 | if (DEBUG_LOGGING) { |
202b76ae ZJS |
458 | _cleanup_free_ char *t = NULL; |
459 | ||
460 | (void) in_addr_to_string(i->owner_family, &i->owner_address, &t); | |
461 | ||
462 | log_debug("Added positive %s%s cache entry for %s "USEC_FMT"s on %s/%s/%s", | |
463 | i->authenticated ? "authenticated" : "unauthenticated", | |
464 | i->shared_owner ? " shared" : "", | |
465 | dns_resource_key_to_string(i->key, key_str, sizeof key_str), | |
466 | (i->until - timestamp) / USEC_PER_SEC, | |
467 | i->ifindex == 0 ? "*" : strna(if_indextoname(i->ifindex, ifname)), | |
468 | af_to_name_short(i->owner_family), | |
469 | strna(t)); | |
a257f9d4 | 470 | } |
6b34a6c9 | 471 | |
7e8e0422 LP |
472 | i = NULL; |
473 | return 0; | |
474 | } | |
475 | ||
a4076574 LP |
476 | static int dns_cache_put_negative( |
477 | DnsCache *c, | |
478 | DnsResourceKey *key, | |
479 | int rcode, | |
931851e8 | 480 | bool authenticated, |
d3760be0 | 481 | uint32_t nsec_ttl, |
a4076574 | 482 | usec_t timestamp, |
b211dc7e | 483 | DnsResourceRecord *soa, |
a4076574 LP |
484 | int owner_family, |
485 | const union in_addr_union *owner_address) { | |
486 | ||
7e8e0422 | 487 | _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL; |
202b76ae | 488 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
7e8e0422 LP |
489 | int r; |
490 | ||
491 | assert(c); | |
492 | assert(key); | |
a4076574 | 493 | assert(owner_address); |
7e8e0422 | 494 | |
98b6be77 LP |
495 | /* Never cache pseudo RR keys. DNS_TYPE_ANY is particularly |
496 | * important to filter out as we use this as a pseudo-type for | |
497 | * NXDOMAIN entries */ | |
222148b6 | 498 | if (dns_class_is_pseudo(key->class)) |
ddf16339 | 499 | return 0; |
c33be4a6 | 500 | if (dns_type_is_pseudo(key->type)) |
ddf16339 | 501 | return 0; |
222148b6 | 502 | |
201d9958 LP |
503 | if (IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN)) { |
504 | if (!soa) | |
505 | return 0; | |
ddf16339 | 506 | |
201d9958 LP |
507 | /* For negative replies, check if we have a TTL of a SOA */ |
508 | if (nsec_ttl <= 0 || soa->soa.minimum <= 0 || soa->ttl <= 0) { | |
509 | log_debug("Not caching negative entry with zero SOA/NSEC/NSEC3 TTL: %s", | |
510 | dns_resource_key_to_string(key, key_str, sizeof key_str)); | |
511 | return 0; | |
512 | } | |
513 | } else if (rcode != DNS_RCODE_SERVFAIL) | |
7e8e0422 LP |
514 | return 0; |
515 | ||
623a4c97 | 516 | r = dns_cache_init(c); |
322345fd LP |
517 | if (r < 0) |
518 | return r; | |
519 | ||
520 | dns_cache_make_space(c, 1); | |
521 | ||
522 | i = new0(DnsCacheItem, 1); | |
523 | if (!i) | |
524 | return -ENOMEM; | |
525 | ||
201d9958 LP |
526 | i->type = |
527 | rcode == DNS_RCODE_SUCCESS ? DNS_CACHE_NODATA : | |
528 | rcode == DNS_RCODE_NXDOMAIN ? DNS_CACHE_NXDOMAIN : DNS_CACHE_RCODE; | |
529 | i->until = | |
530 | i->type == DNS_CACHE_RCODE ? timestamp + CACHE_TTL_STRANGE_RCODE_USEC : | |
531 | calculate_until(soa, nsec_ttl, timestamp, true); | |
d2579eec | 532 | i->authenticated = authenticated; |
a4076574 LP |
533 | i->owner_family = owner_family; |
534 | i->owner_address = *owner_address; | |
d2579eec | 535 | i->prioq_idx = PRIOQ_IDX_NULL; |
201d9958 | 536 | i->rcode = rcode; |
322345fd | 537 | |
71e13669 TG |
538 | if (i->type == DNS_CACHE_NXDOMAIN) { |
539 | /* NXDOMAIN entries should apply equally to all types, so we use ANY as | |
540 | * a pseudo type for this purpose here. */ | |
1c02e7ba | 541 | i->key = dns_resource_key_new(key->class, DNS_TYPE_ANY, dns_resource_key_name(key)); |
71e13669 TG |
542 | if (!i->key) |
543 | return -ENOMEM; | |
a5444ca9 LP |
544 | |
545 | /* Make sure to remove any previous entry for this | |
546 | * specific ANY key. (For non-ANY keys the cache data | |
547 | * is already cleared by the caller.) Note that we | |
548 | * don't bother removing positive or NODATA cache | |
549 | * items in this case, because it would either be slow | |
550 | * or require explicit indexing by name */ | |
551 | dns_cache_remove_by_key(c, key); | |
71e13669 TG |
552 | } else |
553 | i->key = dns_resource_key_ref(key); | |
554 | ||
7e8e0422 | 555 | r = dns_cache_link_item(c, i); |
322345fd LP |
556 | if (r < 0) |
557 | return r; | |
558 | ||
202b76ae | 559 | log_debug("Added %s cache entry for %s "USEC_FMT"s", |
201d9958 | 560 | dns_cache_item_type_to_string(i), |
202b76ae ZJS |
561 | dns_resource_key_to_string(i->key, key_str, sizeof key_str), |
562 | (i->until - timestamp) / USEC_PER_SEC); | |
6b34a6c9 | 563 | |
322345fd | 564 | i = NULL; |
322345fd LP |
565 | return 0; |
566 | } | |
567 | ||
d2579eec LP |
568 | static void dns_cache_remove_previous( |
569 | DnsCache *c, | |
570 | DnsResourceKey *key, | |
571 | DnsAnswer *answer) { | |
572 | ||
573 | DnsResourceRecord *rr; | |
574 | DnsAnswerFlags flags; | |
575 | ||
576 | assert(c); | |
577 | ||
578 | /* First, if we were passed a key (i.e. on LLMNR/DNS, but | |
579 | * not on mDNS), delete all matching old RRs, so that we only | |
580 | * keep complete by_key in place. */ | |
581 | if (key) | |
2dda578f | 582 | dns_cache_remove_by_key(c, key); |
d2579eec LP |
583 | |
584 | /* Second, flush all entries matching the answer, unless this | |
585 | * is an RR that is explicitly marked to be "shared" between | |
586 | * peers (i.e. mDNS RRs without the flush-cache bit set). */ | |
587 | DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { | |
588 | if ((flags & DNS_ANSWER_CACHEABLE) == 0) | |
589 | continue; | |
590 | ||
591 | if (flags & DNS_ANSWER_SHARED_OWNER) | |
592 | continue; | |
593 | ||
2dda578f | 594 | dns_cache_remove_by_key(c, rr->key); |
d2579eec LP |
595 | } |
596 | } | |
597 | ||
f6618dcd LP |
598 | static bool rr_eligible(DnsResourceRecord *rr) { |
599 | assert(rr); | |
600 | ||
601 | /* When we see an NSEC/NSEC3 RR, we'll only cache it if it is from the lower zone, not the upper zone, since | |
602 | * that's where the interesting bits are (with exception of DS RRs). Of course, this way we cannot derive DS | |
603 | * existence from any cached NSEC/NSEC3, but that should be fine. */ | |
604 | ||
605 | switch (rr->key->type) { | |
606 | ||
607 | case DNS_TYPE_NSEC: | |
608 | return !bitmap_isset(rr->nsec.types, DNS_TYPE_NS) || | |
609 | bitmap_isset(rr->nsec.types, DNS_TYPE_SOA); | |
610 | ||
611 | case DNS_TYPE_NSEC3: | |
612 | return !bitmap_isset(rr->nsec3.types, DNS_TYPE_NS) || | |
613 | bitmap_isset(rr->nsec3.types, DNS_TYPE_SOA); | |
614 | ||
615 | default: | |
616 | return true; | |
617 | } | |
618 | } | |
619 | ||
a4076574 LP |
620 | int dns_cache_put( |
621 | DnsCache *c, | |
8e427d9b | 622 | DnsResourceKey *key, |
a4076574 LP |
623 | int rcode, |
624 | DnsAnswer *answer, | |
931851e8 | 625 | bool authenticated, |
d3760be0 | 626 | uint32_t nsec_ttl, |
a4076574 LP |
627 | usec_t timestamp, |
628 | int owner_family, | |
629 | const union in_addr_union *owner_address) { | |
630 | ||
02c2857b | 631 | DnsResourceRecord *soa = NULL, *rr; |
201d9958 | 632 | bool weird_rcode = false; |
105e1512 LP |
633 | DnsAnswerFlags flags; |
634 | unsigned cache_keys; | |
06d12754 | 635 | int r, ifindex; |
322345fd LP |
636 | |
637 | assert(c); | |
d2579eec | 638 | assert(owner_address); |
322345fd | 639 | |
d2579eec | 640 | dns_cache_remove_previous(c, key, answer); |
0ec7c46e | 641 | |
201d9958 LP |
642 | /* We only care for positive replies and NXDOMAINs, on all other replies we will simply flush the respective |
643 | * entries, and that's it. (Well, with one further exception: since some DNS zones (akamai!) return SERVFAIL | |
644 | * consistently for some lookups, and forwarders tend to propagate that we'll cache that too, but only for a | |
645 | * short time.) */ | |
6ff01a0d | 646 | |
201d9958 | 647 | if (IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN)) { |
201d9958 | 648 | if (dns_answer_size(answer) <= 0) { |
e55fc5b0 YW |
649 | if (key) { |
650 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; | |
201d9958 | 651 | |
e55fc5b0 YW |
652 | log_debug("Not caching negative entry without a SOA record: %s", |
653 | dns_resource_key_to_string(key, key_str, sizeof key_str)); | |
654 | } | |
201d9958 LP |
655 | return 0; |
656 | } | |
657 | ||
658 | } else { | |
659 | /* Only cache SERVFAIL as "weird" rcode for now. We can add more later, should that turn out to be | |
660 | * beneficial. */ | |
661 | if (rcode != DNS_RCODE_SERVFAIL) | |
662 | return 0; | |
663 | ||
664 | weird_rcode = true; | |
c3cb6dc2 | 665 | } |
0ec7c46e | 666 | |
ea207b63 | 667 | cache_keys = dns_answer_size(answer); |
8e427d9b | 668 | if (key) |
313cefa1 | 669 | cache_keys++; |
eff91ee0 | 670 | |
7e8e0422 | 671 | /* Make some space for our new entries */ |
eff91ee0 | 672 | dns_cache_make_space(c, cache_keys); |
322345fd | 673 | |
7e8e0422 | 674 | if (timestamp <= 0) |
240b589b | 675 | timestamp = now(clock_boottime_or_monotonic()); |
322345fd | 676 | |
7e8e0422 | 677 | /* Second, add in positive entries for all contained RRs */ |
06d12754 | 678 | DNS_ANSWER_FOREACH_FULL(rr, ifindex, flags, answer) { |
fa6a69d7 YW |
679 | if ((flags & DNS_ANSWER_CACHEABLE) == 0 || |
680 | !rr_eligible(rr)) | |
f6618dcd LP |
681 | continue; |
682 | ||
d2579eec LP |
683 | r = dns_cache_put_positive( |
684 | c, | |
685 | rr, | |
686 | flags & DNS_ANSWER_AUTHENTICATED, | |
687 | flags & DNS_ANSWER_SHARED_OWNER, | |
688 | timestamp, | |
06d12754 | 689 | ifindex, |
d2579eec | 690 | owner_family, owner_address); |
7e8e0422 LP |
691 | if (r < 0) |
692 | goto fail; | |
693 | } | |
694 | ||
d2579eec | 695 | if (!key) /* mDNS doesn't know negative caching, really */ |
eff91ee0 DM |
696 | return 0; |
697 | ||
8e427d9b | 698 | /* Third, add in negative entries if the key has no RR */ |
105e1512 | 699 | r = dns_answer_match_key(answer, key, NULL); |
8e427d9b TG |
700 | if (r < 0) |
701 | goto fail; | |
702 | if (r > 0) | |
703 | return 0; | |
7e8e0422 | 704 | |
5d27351f TG |
705 | /* But not if it has a matching CNAME/DNAME (the negative |
706 | * caching will be done on the canonical name, not on the | |
707 | * alias) */ | |
105e1512 | 708 | r = dns_answer_find_cname_or_dname(answer, key, NULL, NULL); |
5d27351f TG |
709 | if (r < 0) |
710 | goto fail; | |
711 | if (r > 0) | |
712 | return 0; | |
713 | ||
201d9958 LP |
714 | /* See https://tools.ietf.org/html/rfc2308, which say that a matching SOA record in the packet is used to |
715 | * enable negative caching. We apply one exception though: if we are about to cache a weird rcode we do so | |
716 | * regardless of a SOA. */ | |
fd009cd8 | 717 | r = dns_answer_find_soa(answer, key, &soa, &flags); |
8e427d9b TG |
718 | if (r < 0) |
719 | goto fail; | |
201d9958 | 720 | if (r == 0 && !weird_rcode) |
fd009cd8 | 721 | return 0; |
201d9958 LP |
722 | if (r > 0) { |
723 | /* Refuse using the SOA data if it is unsigned, but the key is | |
724 | * signed */ | |
725 | if (authenticated && (flags & DNS_ANSWER_AUTHENTICATED) == 0) | |
726 | return 0; | |
727 | } | |
fd009cd8 | 728 | |
d2579eec LP |
729 | r = dns_cache_put_negative( |
730 | c, | |
731 | key, | |
732 | rcode, | |
733 | authenticated, | |
d3760be0 | 734 | nsec_ttl, |
d2579eec | 735 | timestamp, |
b211dc7e | 736 | soa, |
d2579eec | 737 | owner_family, owner_address); |
8e427d9b TG |
738 | if (r < 0) |
739 | goto fail; | |
322345fd LP |
740 | |
741 | return 0; | |
742 | ||
743 | fail: | |
744 | /* Adding all RRs failed. Let's clean up what we already | |
745 | * added, just in case */ | |
746 | ||
8e427d9b | 747 | if (key) |
2dda578f | 748 | dns_cache_remove_by_key(c, key); |
eff91ee0 | 749 | |
105e1512 LP |
750 | DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { |
751 | if ((flags & DNS_ANSWER_CACHEABLE) == 0) | |
752 | continue; | |
753 | ||
2dda578f | 754 | dns_cache_remove_by_key(c, rr->key); |
105e1512 | 755 | } |
322345fd LP |
756 | |
757 | return r; | |
758 | } | |
759 | ||
37da8931 | 760 | static DnsCacheItem *dns_cache_get_by_key_follow_cname_dname_nsec(DnsCache *c, DnsResourceKey *k) { |
58db254a LP |
761 | DnsCacheItem *i; |
762 | const char *n; | |
763 | int r; | |
5643c00a TG |
764 | |
765 | assert(c); | |
766 | assert(k); | |
767 | ||
58db254a LP |
768 | /* If we hit some OOM error, or suchlike, we don't care too |
769 | * much, after all this is just a cache */ | |
770 | ||
5643c00a | 771 | i = hashmap_get(c->by_key, k); |
d7ce6c94 | 772 | if (i) |
37da8931 LP |
773 | return i; |
774 | ||
1c02e7ba | 775 | n = dns_resource_key_name(k); |
37da8931 | 776 | |
71e13669 TG |
777 | /* Check if we have an NXDOMAIN cache item for the name, notice that we use |
778 | * the pseudo-type ANY for NXDOMAIN cache items. */ | |
779 | i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_ANY, n)); | |
780 | if (i && i->type == DNS_CACHE_NXDOMAIN) | |
781 | return i; | |
782 | ||
d3c7e913 | 783 | if (dns_type_may_redirect(k->type)) { |
d7ce6c94 TG |
784 | /* Check if we have a CNAME record instead */ |
785 | i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_CNAME, n)); | |
3740146a | 786 | if (i && i->type != DNS_CACHE_NODATA) |
d7ce6c94 | 787 | return i; |
5643c00a | 788 | |
d7ce6c94 TG |
789 | /* OK, let's look for cached DNAME records. */ |
790 | for (;;) { | |
d7ce6c94 TG |
791 | if (isempty(n)) |
792 | return NULL; | |
793 | ||
794 | i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_DNAME, n)); | |
3740146a | 795 | if (i && i->type != DNS_CACHE_NODATA) |
d7ce6c94 | 796 | return i; |
58db254a | 797 | |
d7ce6c94 | 798 | /* Jump one label ahead */ |
950b692b | 799 | r = dns_name_parent(&n); |
d7ce6c94 TG |
800 | if (r <= 0) |
801 | return NULL; | |
802 | } | |
803 | } | |
5643c00a | 804 | |
950b692b | 805 | if (k->type != DNS_TYPE_NSEC) { |
d7ce6c94 TG |
806 | /* Check if we have an NSEC record instead for the name. */ |
807 | i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_NSEC, n)); | |
58db254a LP |
808 | if (i) |
809 | return i; | |
58db254a LP |
810 | } |
811 | ||
812 | return NULL; | |
5643c00a TG |
813 | } |
814 | ||
17c8de63 | 815 | int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, bool clamp_ttl, int *rcode, DnsAnswer **ret, bool *authenticated) { |
faa133f3 | 816 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; |
202b76ae | 817 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
f52e61da | 818 | unsigned n = 0; |
322345fd | 819 | int r; |
7e8e0422 | 820 | bool nxdomain = false; |
931851e8 LP |
821 | DnsCacheItem *j, *first, *nsec = NULL; |
822 | bool have_authenticated = false, have_non_authenticated = false; | |
17c8de63 | 823 | usec_t current; |
201d9958 | 824 | int found_rcode = -1; |
322345fd LP |
825 | |
826 | assert(c); | |
f52e61da | 827 | assert(key); |
623a4c97 | 828 | assert(rcode); |
faa133f3 | 829 | assert(ret); |
931851e8 | 830 | assert(authenticated); |
322345fd | 831 | |
202b76ae | 832 | if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) { |
931851e8 LP |
833 | /* If we have ANY lookups we don't use the cache, so |
834 | * that the caller refreshes via the network. */ | |
322345fd | 835 | |
202b76ae ZJS |
836 | log_debug("Ignoring cache for ANY lookup: %s", |
837 | dns_resource_key_to_string(key, key_str, sizeof key_str)); | |
6b34a6c9 | 838 | |
a150ff5e LP |
839 | c->n_miss++; |
840 | ||
f52e61da LP |
841 | *ret = NULL; |
842 | *rcode = DNS_RCODE_SUCCESS; | |
2d4a4e14 LP |
843 | *authenticated = false; |
844 | ||
f52e61da LP |
845 | return 0; |
846 | } | |
6b34a6c9 | 847 | |
37da8931 | 848 | first = dns_cache_get_by_key_follow_cname_dname_nsec(c, key); |
f52e61da LP |
849 | if (!first) { |
850 | /* If one question cannot be answered we need to refresh */ | |
ddf16339 | 851 | |
202b76ae ZJS |
852 | log_debug("Cache miss for %s", |
853 | dns_resource_key_to_string(key, key_str, sizeof key_str)); | |
6b34a6c9 | 854 | |
a150ff5e LP |
855 | c->n_miss++; |
856 | ||
f52e61da LP |
857 | *ret = NULL; |
858 | *rcode = DNS_RCODE_SUCCESS; | |
2d4a4e14 LP |
859 | *authenticated = false; |
860 | ||
f52e61da LP |
861 | return 0; |
862 | } | |
6b34a6c9 | 863 | |
f52e61da | 864 | LIST_FOREACH(by_key, j, first) { |
37da8931 LP |
865 | if (j->rr) { |
866 | if (j->rr->key->type == DNS_TYPE_NSEC) | |
931851e8 LP |
867 | nsec = j; |
868 | ||
f52e61da | 869 | n++; |
37da8931 | 870 | } else if (j->type == DNS_CACHE_NXDOMAIN) |
f52e61da | 871 | nxdomain = true; |
201d9958 LP |
872 | else if (j->type == DNS_CACHE_RCODE) |
873 | found_rcode = j->rcode; | |
931851e8 LP |
874 | |
875 | if (j->authenticated) | |
876 | have_authenticated = true; | |
877 | else | |
878 | have_non_authenticated = true; | |
f52e61da | 879 | } |
6b34a6c9 | 880 | |
201d9958 LP |
881 | if (found_rcode >= 0) { |
882 | log_debug("RCODE %s cache hit for %s", | |
883 | dns_rcode_to_string(found_rcode), | |
884 | dns_resource_key_to_string(key, key_str, sizeof(key_str))); | |
885 | ||
886 | *ret = NULL; | |
887 | *rcode = found_rcode; | |
888 | *authenticated = false; | |
889 | ||
890 | c->n_hit++; | |
891 | return 1; | |
892 | } | |
893 | ||
f6618dcd LP |
894 | if (nsec && !IN_SET(key->type, DNS_TYPE_NSEC, DNS_TYPE_DS)) { |
895 | /* Note that we won't derive information for DS RRs from an NSEC, because we only cache NSEC RRs from | |
896 | * the lower-zone of a zone cut, but the DS RRs are on the upper zone. */ | |
897 | ||
202b76ae ZJS |
898 | log_debug("NSEC NODATA cache hit for %s", |
899 | dns_resource_key_to_string(key, key_str, sizeof key_str)); | |
37da8931 LP |
900 | |
901 | /* We only found an NSEC record that matches our name. | |
a257f9d4 | 902 | * If it says the type doesn't exist report |
37da8931 LP |
903 | * NODATA. Otherwise report a cache miss. */ |
904 | ||
905 | *ret = NULL; | |
906 | *rcode = DNS_RCODE_SUCCESS; | |
931851e8 | 907 | *authenticated = nsec->authenticated; |
37da8931 | 908 | |
a150ff5e LP |
909 | if (!bitmap_isset(nsec->rr->nsec.types, key->type) && |
910 | !bitmap_isset(nsec->rr->nsec.types, DNS_TYPE_CNAME) && | |
911 | !bitmap_isset(nsec->rr->nsec.types, DNS_TYPE_DNAME)) { | |
912 | c->n_hit++; | |
913 | return 1; | |
914 | } | |
915 | ||
916 | c->n_miss++; | |
917 | return 0; | |
37da8931 LP |
918 | } |
919 | ||
202b76ae ZJS |
920 | log_debug("%s cache hit for %s", |
921 | n > 0 ? "Positive" : | |
922 | nxdomain ? "NXDOMAIN" : "NODATA", | |
923 | dns_resource_key_to_string(key, key_str, sizeof key_str)); | |
faa133f3 | 924 | |
7e8e0422 | 925 | if (n <= 0) { |
a150ff5e LP |
926 | c->n_hit++; |
927 | ||
7e8e0422 LP |
928 | *ret = NULL; |
929 | *rcode = nxdomain ? DNS_RCODE_NXDOMAIN : DNS_RCODE_SUCCESS; | |
931851e8 | 930 | *authenticated = have_authenticated && !have_non_authenticated; |
7e8e0422 LP |
931 | return 1; |
932 | } | |
faa133f3 LP |
933 | |
934 | answer = dns_answer_new(n); | |
935 | if (!answer) | |
936 | return -ENOMEM; | |
322345fd | 937 | |
17c8de63 LP |
938 | if (clamp_ttl) |
939 | current = now(clock_boottime_or_monotonic()); | |
940 | ||
f52e61da | 941 | LIST_FOREACH(by_key, j, first) { |
17c8de63 LP |
942 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; |
943 | ||
f52e61da LP |
944 | if (!j->rr) |
945 | continue; | |
946 | ||
17c8de63 LP |
947 | if (clamp_ttl) { |
948 | rr = dns_resource_record_ref(j->rr); | |
949 | ||
950 | r = dns_resource_record_clamp_ttl(&rr, LESS_BY(j->until, current) / USEC_PER_SEC); | |
951 | if (r < 0) | |
952 | return r; | |
953 | } | |
954 | ||
955 | r = dns_answer_add(answer, rr ?: j->rr, j->ifindex, j->authenticated ? DNS_ANSWER_AUTHENTICATED : 0); | |
f52e61da LP |
956 | if (r < 0) |
957 | return r; | |
322345fd LP |
958 | } |
959 | ||
a150ff5e LP |
960 | c->n_hit++; |
961 | ||
faa133f3 | 962 | *ret = answer; |
7e8e0422 | 963 | *rcode = DNS_RCODE_SUCCESS; |
931851e8 | 964 | *authenticated = have_authenticated && !have_non_authenticated; |
faa133f3 LP |
965 | answer = NULL; |
966 | ||
967 | return n; | |
322345fd | 968 | } |
a4076574 LP |
969 | |
970 | int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_family, const union in_addr_union *owner_address) { | |
971 | DnsCacheItem *i, *first; | |
972 | bool same_owner = true; | |
973 | ||
974 | assert(cache); | |
975 | assert(rr); | |
976 | ||
977 | dns_cache_prune(cache); | |
978 | ||
979 | /* See if there's a cache entry for the same key. If there | |
980 | * isn't there's no conflict */ | |
981 | first = hashmap_get(cache->by_key, rr->key); | |
982 | if (!first) | |
983 | return 0; | |
984 | ||
985 | /* See if the RR key is owned by the same owner, if so, there | |
986 | * isn't a conflict either */ | |
987 | LIST_FOREACH(by_key, i, first) { | |
988 | if (i->owner_family != owner_family || | |
989 | !in_addr_equal(owner_family, &i->owner_address, owner_address)) { | |
990 | same_owner = false; | |
991 | break; | |
992 | } | |
993 | } | |
994 | if (same_owner) | |
995 | return 0; | |
996 | ||
997 | /* See if there's the exact same RR in the cache. If yes, then | |
998 | * there's no conflict. */ | |
999 | if (dns_cache_get(cache, rr)) | |
1000 | return 0; | |
1001 | ||
1002 | /* There's a conflict */ | |
1003 | return 1; | |
1004 | } | |
4d506d6b | 1005 | |
7778dfff DM |
1006 | int dns_cache_export_shared_to_packet(DnsCache *cache, DnsPacket *p) { |
1007 | unsigned ancount = 0; | |
1008 | Iterator iterator; | |
1009 | DnsCacheItem *i; | |
1010 | int r; | |
1011 | ||
1012 | assert(cache); | |
261f3673 | 1013 | assert(p); |
7778dfff DM |
1014 | |
1015 | HASHMAP_FOREACH(i, cache->by_key, iterator) { | |
1016 | DnsCacheItem *j; | |
1017 | ||
1018 | LIST_FOREACH(by_key, j, i) { | |
7778dfff DM |
1019 | if (!j->rr) |
1020 | continue; | |
1021 | ||
d2579eec | 1022 | if (!j->shared_owner) |
7778dfff DM |
1023 | continue; |
1024 | ||
58ab31d5 | 1025 | r = dns_packet_append_rr(p, j->rr, 0, NULL, NULL); |
261f3673 DM |
1026 | if (r == -EMSGSIZE && p->protocol == DNS_PROTOCOL_MDNS) { |
1027 | /* For mDNS, if we're unable to stuff all known answers into the given packet, | |
1028 | * allocate a new one, push the RR into that one and link it to the current one. | |
1029 | */ | |
1030 | ||
1031 | DNS_PACKET_HEADER(p)->ancount = htobe16(ancount); | |
1032 | ancount = 0; | |
1033 | ||
1034 | r = dns_packet_new_query(&p->more, p->protocol, 0, true); | |
1035 | if (r < 0) | |
1036 | return r; | |
1037 | ||
1038 | /* continue with new packet */ | |
1039 | p = p->more; | |
58ab31d5 | 1040 | r = dns_packet_append_rr(p, j->rr, 0, NULL, NULL); |
261f3673 DM |
1041 | } |
1042 | ||
7778dfff DM |
1043 | if (r < 0) |
1044 | return r; | |
1045 | ||
313cefa1 | 1046 | ancount++; |
7778dfff DM |
1047 | } |
1048 | } | |
1049 | ||
1050 | DNS_PACKET_HEADER(p)->ancount = htobe16(ancount); | |
1051 | ||
1052 | return 0; | |
1053 | } | |
1054 | ||
4d506d6b LP |
1055 | void dns_cache_dump(DnsCache *cache, FILE *f) { |
1056 | Iterator iterator; | |
1057 | DnsCacheItem *i; | |
4d506d6b LP |
1058 | |
1059 | if (!cache) | |
1060 | return; | |
1061 | ||
1062 | if (!f) | |
1063 | f = stdout; | |
1064 | ||
1065 | HASHMAP_FOREACH(i, cache->by_key, iterator) { | |
1066 | DnsCacheItem *j; | |
1067 | ||
1068 | LIST_FOREACH(by_key, j, i) { | |
4d506d6b LP |
1069 | |
1070 | fputc('\t', f); | |
1071 | ||
1072 | if (j->rr) { | |
7b50eb2e LP |
1073 | const char *t; |
1074 | t = dns_resource_record_to_string(j->rr); | |
1075 | if (!t) { | |
4d506d6b LP |
1076 | log_oom(); |
1077 | continue; | |
1078 | } | |
1079 | ||
1080 | fputs(t, f); | |
1081 | fputc('\n', f); | |
1082 | } else { | |
202b76ae | 1083 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
4d506d6b | 1084 | |
202b76ae | 1085 | fputs(dns_resource_key_to_string(j->key, key_str, sizeof key_str), f); |
4d506d6b | 1086 | fputs(" -- ", f); |
201d9958 | 1087 | fputs(dns_cache_item_type_to_string(j), f); |
4d506d6b LP |
1088 | fputc('\n', f); |
1089 | } | |
1090 | } | |
1091 | } | |
1092 | } | |
1093 | ||
1094 | bool dns_cache_is_empty(DnsCache *cache) { | |
1095 | if (!cache) | |
1096 | return true; | |
1097 | ||
1098 | return hashmap_isempty(cache->by_key); | |
1099 | } | |
a150ff5e LP |
1100 | |
1101 | unsigned dns_cache_size(DnsCache *cache) { | |
1102 | if (!cache) | |
1103 | return 0; | |
1104 | ||
1105 | return hashmap_size(cache->by_key); | |
1106 | } |