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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
faa133f3 LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2014 Lennart Poettering | |
faa133f3 LP |
6 | ***/ |
7 | ||
b5efdb8a | 8 | #include "alloc-util.h" |
4ad7f276 | 9 | #include "dns-domain.h" |
0f7091e6 | 10 | #include "dns-type.h" |
b5efdb8a | 11 | #include "resolved-dns-question.h" |
faa133f3 LP |
12 | |
13 | DnsQuestion *dns_question_new(unsigned n) { | |
14 | DnsQuestion *q; | |
15 | ||
16 | assert(n > 0); | |
17 | ||
18 | q = malloc0(offsetof(DnsQuestion, keys) + sizeof(DnsResourceKey*) * n); | |
19 | if (!q) | |
20 | return NULL; | |
21 | ||
22 | q->n_ref = 1; | |
23 | q->n_allocated = n; | |
24 | ||
25 | return q; | |
26 | } | |
27 | ||
28 | DnsQuestion *dns_question_ref(DnsQuestion *q) { | |
29 | if (!q) | |
30 | return NULL; | |
31 | ||
32 | assert(q->n_ref > 0); | |
33 | q->n_ref++; | |
34 | return q; | |
35 | } | |
36 | ||
37 | DnsQuestion *dns_question_unref(DnsQuestion *q) { | |
38 | if (!q) | |
39 | return NULL; | |
40 | ||
41 | assert(q->n_ref > 0); | |
42 | ||
43 | if (q->n_ref == 1) { | |
44 | unsigned i; | |
45 | ||
46 | for (i = 0; i < q->n_keys; i++) | |
47 | dns_resource_key_unref(q->keys[i]); | |
48 | free(q); | |
49 | } else | |
50 | q->n_ref--; | |
51 | ||
52 | return NULL; | |
53 | } | |
54 | ||
55 | int dns_question_add(DnsQuestion *q, DnsResourceKey *key) { | |
7e8e0422 LP |
56 | unsigned i; |
57 | int r; | |
58 | ||
faa133f3 LP |
59 | assert(key); |
60 | ||
8013e860 LP |
61 | if (!q) |
62 | return -ENOSPC; | |
63 | ||
7e8e0422 LP |
64 | for (i = 0; i < q->n_keys; i++) { |
65 | r = dns_resource_key_equal(q->keys[i], key); | |
66 | if (r < 0) | |
67 | return r; | |
68 | if (r > 0) | |
69 | return 0; | |
70 | } | |
71 | ||
faa133f3 LP |
72 | if (q->n_keys >= q->n_allocated) |
73 | return -ENOSPC; | |
74 | ||
75 | q->keys[q->n_keys++] = dns_resource_key_ref(key); | |
76 | return 0; | |
77 | } | |
78 | ||
801ad6a6 | 79 | int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { |
faa133f3 LP |
80 | unsigned i; |
81 | int r; | |
82 | ||
faa133f3 LP |
83 | assert(rr); |
84 | ||
8013e860 LP |
85 | if (!q) |
86 | return 0; | |
87 | ||
faa133f3 | 88 | for (i = 0; i < q->n_keys; i++) { |
801ad6a6 | 89 | r = dns_resource_key_match_rr(q->keys[i], rr, search_domain); |
faa133f3 LP |
90 | if (r != 0) |
91 | return r; | |
92 | } | |
93 | ||
94 | return 0; | |
95 | } | |
96 | ||
542e0c84 | 97 | int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { |
faa133f3 LP |
98 | unsigned i; |
99 | int r; | |
100 | ||
faa133f3 LP |
101 | assert(rr); |
102 | ||
8013e860 LP |
103 | if (!q) |
104 | return 0; | |
105 | ||
542e0c84 LP |
106 | if (!IN_SET(rr->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)) |
107 | return 0; | |
108 | ||
faa133f3 | 109 | for (i = 0; i < q->n_keys; i++) { |
542e0c84 LP |
110 | /* For a {C,D}NAME record we can never find a matching {C,D}NAME record */ |
111 | if (!dns_type_may_redirect(q->keys[i]->type)) | |
112 | return 0; | |
113 | ||
5d27351f | 114 | r = dns_resource_key_match_cname_or_dname(q->keys[i], rr->key, search_domain); |
faa133f3 LP |
115 | if (r != 0) |
116 | return r; | |
117 | } | |
118 | ||
34b9656f | 119 | return 0; |
faa133f3 LP |
120 | } |
121 | ||
703e4f5e | 122 | int dns_question_is_valid_for_query(DnsQuestion *q) { |
faa133f3 LP |
123 | const char *name; |
124 | unsigned i; | |
125 | int r; | |
126 | ||
8013e860 LP |
127 | if (!q) |
128 | return 0; | |
faa133f3 LP |
129 | |
130 | if (q->n_keys <= 0) | |
131 | return 0; | |
132 | ||
133 | if (q->n_keys > 65535) | |
134 | return 0; | |
135 | ||
1c02e7ba | 136 | name = dns_resource_key_name(q->keys[0]); |
faa133f3 LP |
137 | if (!name) |
138 | return 0; | |
139 | ||
140 | /* Check that all keys in this question bear the same name */ | |
0f7091e6 | 141 | for (i = 0; i < q->n_keys; i++) { |
34b9656f LP |
142 | assert(q->keys[i]); |
143 | ||
0f7091e6 | 144 | if (i > 0) { |
1c02e7ba | 145 | r = dns_name_equal(dns_resource_key_name(q->keys[i]), name); |
0f7091e6 LP |
146 | if (r <= 0) |
147 | return r; | |
148 | } | |
149 | ||
150 | if (!dns_type_is_valid_query(q->keys[i]->type)) | |
151 | return 0; | |
faa133f3 LP |
152 | } |
153 | ||
154 | return 1; | |
155 | } | |
156 | ||
6a21960c | 157 | int dns_question_contains(DnsQuestion *a, const DnsResourceKey *k) { |
1086182d LP |
158 | unsigned j; |
159 | int r; | |
160 | ||
1086182d LP |
161 | assert(k); |
162 | ||
8013e860 LP |
163 | if (!a) |
164 | return 0; | |
165 | ||
1086182d LP |
166 | for (j = 0; j < a->n_keys; j++) { |
167 | r = dns_resource_key_equal(a->keys[j], k); | |
168 | if (r != 0) | |
169 | return r; | |
170 | } | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) { | |
176 | unsigned j; | |
177 | int r; | |
178 | ||
b6800689 LP |
179 | if (a == b) |
180 | return 1; | |
181 | ||
8013e860 LP |
182 | if (!a) |
183 | return !b || b->n_keys == 0; | |
184 | if (!b) | |
185 | return a->n_keys == 0; | |
1086182d LP |
186 | |
187 | /* Checks if all keys in a are also contained b, and vice versa */ | |
188 | ||
189 | for (j = 0; j < a->n_keys; j++) { | |
190 | r = dns_question_contains(b, a->keys[j]); | |
191 | if (r <= 0) | |
192 | return r; | |
193 | } | |
194 | ||
195 | for (j = 0; j < b->n_keys; j++) { | |
196 | r = dns_question_contains(a, b->keys[j]); | |
197 | if (r <= 0) | |
198 | return r; | |
199 | } | |
200 | ||
201 | return 1; | |
202 | } | |
203 | ||
36d9205d | 204 | int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) { |
faa133f3 | 205 | _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL; |
23b298bc | 206 | DnsResourceKey *key; |
faa133f3 | 207 | bool same = true; |
faa133f3 LP |
208 | int r; |
209 | ||
36d9205d | 210 | assert(cname); |
faa133f3 | 211 | assert(ret); |
58db254a | 212 | assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)); |
faa133f3 | 213 | |
23b298bc LP |
214 | if (dns_question_size(q) <= 0) { |
215 | *ret = NULL; | |
8013e860 LP |
216 | return 0; |
217 | } | |
218 | ||
23b298bc | 219 | DNS_QUESTION_FOREACH(key, q) { |
58db254a LP |
220 | _cleanup_free_ char *destination = NULL; |
221 | const char *d; | |
222 | ||
223 | if (cname->key->type == DNS_TYPE_CNAME) | |
224 | d = cname->cname.name; | |
225 | else { | |
1c02e7ba | 226 | r = dns_name_change_suffix(dns_resource_key_name(key), dns_resource_key_name(cname->key), cname->dname.name, &destination); |
58db254a LP |
227 | if (r < 0) |
228 | return r; | |
229 | if (r == 0) | |
230 | continue; | |
231 | ||
232 | d = destination; | |
233 | } | |
234 | ||
1c02e7ba | 235 | r = dns_name_equal(dns_resource_key_name(key), d); |
faa133f3 LP |
236 | if (r < 0) |
237 | return r; | |
238 | ||
239 | if (r == 0) { | |
240 | same = false; | |
241 | break; | |
242 | } | |
243 | } | |
244 | ||
23b298bc | 245 | /* Fully the same, indicate we didn't do a thing */ |
faa133f3 | 246 | if (same) { |
23b298bc | 247 | *ret = NULL; |
faa133f3 LP |
248 | return 0; |
249 | } | |
250 | ||
251 | n = dns_question_new(q->n_keys); | |
252 | if (!n) | |
253 | return -ENOMEM; | |
254 | ||
255 | /* Create a new question, and patch in the new name */ | |
23b298bc | 256 | DNS_QUESTION_FOREACH(key, q) { |
faa133f3 LP |
257 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; |
258 | ||
23b298bc | 259 | k = dns_resource_key_new_redirect(key, cname); |
faa133f3 LP |
260 | if (!k) |
261 | return -ENOMEM; | |
262 | ||
263 | r = dns_question_add(n, k); | |
264 | if (r < 0) | |
265 | return r; | |
266 | } | |
267 | ||
1cc6c93a | 268 | *ret = TAKE_PTR(n); |
faa133f3 LP |
269 | |
270 | return 1; | |
271 | } | |
45ec7efb | 272 | |
703e4f5e LP |
273 | const char *dns_question_first_name(DnsQuestion *q) { |
274 | ||
275 | if (!q) | |
276 | return NULL; | |
45ec7efb LP |
277 | |
278 | if (q->n_keys < 1) | |
279 | return NULL; | |
280 | ||
1c02e7ba | 281 | return dns_resource_key_name(q->keys[0]); |
45ec7efb LP |
282 | } |
283 | ||
23b298bc | 284 | int dns_question_new_address(DnsQuestion **ret, int family, const char *name, bool convert_idna) { |
45ec7efb | 285 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; |
23b298bc | 286 | _cleanup_free_ char *buf = NULL; |
45ec7efb LP |
287 | int r; |
288 | ||
289 | assert(ret); | |
290 | assert(name); | |
291 | ||
292 | if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) | |
293 | return -EAFNOSUPPORT; | |
294 | ||
23b298bc LP |
295 | if (convert_idna) { |
296 | r = dns_name_apply_idna(name, &buf); | |
297 | if (r < 0) | |
298 | return r; | |
ad1f3fe6 | 299 | if (r > 0 && !streq(name, buf)) |
87057e24 | 300 | name = buf; |
ad1f3fe6 ZJS |
301 | else |
302 | /* We did not manage to create convert the idna name, or it's | |
303 | * the same as the original name. We assume the caller already | |
304 | * created an uncoverted question, so let's not repeat work | |
305 | * unnecessarily. */ | |
306 | return -EALREADY; | |
23b298bc LP |
307 | } |
308 | ||
45ec7efb LP |
309 | q = dns_question_new(family == AF_UNSPEC ? 2 : 1); |
310 | if (!q) | |
311 | return -ENOMEM; | |
312 | ||
313 | if (family != AF_INET6) { | |
314 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
315 | ||
316 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, name); | |
317 | if (!key) | |
318 | return -ENOMEM; | |
319 | ||
320 | r = dns_question_add(q, key); | |
321 | if (r < 0) | |
322 | return r; | |
323 | } | |
324 | ||
325 | if (family != AF_INET) { | |
326 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
327 | ||
328 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, name); | |
329 | if (!key) | |
330 | return -ENOMEM; | |
331 | ||
332 | r = dns_question_add(q, key); | |
333 | if (r < 0) | |
334 | return r; | |
335 | } | |
336 | ||
1cc6c93a | 337 | *ret = TAKE_PTR(q); |
45ec7efb LP |
338 | |
339 | return 0; | |
340 | } | |
341 | ||
342 | int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a) { | |
343 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
344 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; | |
345 | _cleanup_free_ char *reverse = NULL; | |
346 | int r; | |
347 | ||
348 | assert(ret); | |
349 | assert(a); | |
350 | ||
351 | if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) | |
352 | return -EAFNOSUPPORT; | |
353 | ||
354 | r = dns_name_reverse(family, a, &reverse); | |
355 | if (r < 0) | |
356 | return r; | |
357 | ||
358 | q = dns_question_new(1); | |
359 | if (!q) | |
360 | return -ENOMEM; | |
361 | ||
362 | key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse); | |
363 | if (!key) | |
364 | return -ENOMEM; | |
365 | ||
366 | reverse = NULL; | |
367 | ||
368 | r = dns_question_add(q, key); | |
369 | if (r < 0) | |
370 | return r; | |
371 | ||
1cc6c93a | 372 | *ret = TAKE_PTR(q); |
45ec7efb LP |
373 | |
374 | return 0; | |
375 | } | |
376 | ||
23b298bc LP |
377 | int dns_question_new_service( |
378 | DnsQuestion **ret, | |
379 | const char *service, | |
380 | const char *type, | |
381 | const char *domain, | |
382 | bool with_txt, | |
383 | bool convert_idna) { | |
384 | ||
45ec7efb LP |
385 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
386 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; | |
23b298bc LP |
387 | _cleanup_free_ char *buf = NULL, *joined = NULL; |
388 | const char *name; | |
45ec7efb LP |
389 | int r; |
390 | ||
391 | assert(ret); | |
23b298bc LP |
392 | |
393 | /* We support three modes of invocation: | |
394 | * | |
395 | * 1. Only a domain is specified, in which case we assume a properly encoded SRV RR name, including service | |
396 | * type and possibly a service name. If specified in this way we assume it's already IDNA converted if | |
397 | * that's necessary. | |
398 | * | |
399 | * 2. Both service type and a domain specified, in which case a normal SRV RR is assumed, without a DNS-SD | |
400 | * style prefix. In this case we'll IDNA convert the domain, if that's requested. | |
401 | * | |
402 | * 3. All three of service name, type and domain are specified, in which case a DNS-SD service is put | |
403 | * together. The service name is never IDNA converted, and the domain is if requested. | |
404 | * | |
405 | * It's not supported to specify a service name without a type, or no domain name. | |
406 | */ | |
407 | ||
408 | if (!domain) | |
409 | return -EINVAL; | |
410 | ||
411 | if (type) { | |
412 | if (convert_idna) { | |
413 | r = dns_name_apply_idna(domain, &buf); | |
414 | if (r < 0) | |
415 | return r; | |
87057e24 ZJS |
416 | if (r > 0) |
417 | domain = buf; | |
23b298bc LP |
418 | } |
419 | ||
420 | r = dns_service_join(service, type, domain, &joined); | |
421 | if (r < 0) | |
422 | return r; | |
423 | ||
424 | name = joined; | |
425 | } else { | |
426 | if (service) | |
427 | return -EINVAL; | |
428 | ||
429 | name = domain; | |
430 | } | |
45ec7efb LP |
431 | |
432 | q = dns_question_new(1 + with_txt); | |
433 | if (!q) | |
434 | return -ENOMEM; | |
435 | ||
436 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_SRV, name); | |
437 | if (!key) | |
438 | return -ENOMEM; | |
439 | ||
440 | r = dns_question_add(q, key); | |
441 | if (r < 0) | |
442 | return r; | |
443 | ||
444 | if (with_txt) { | |
445 | dns_resource_key_unref(key); | |
446 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_TXT, name); | |
447 | if (!key) | |
448 | return -ENOMEM; | |
449 | ||
450 | r = dns_question_add(q, key); | |
451 | if (r < 0) | |
452 | return r; | |
453 | } | |
454 | ||
1cc6c93a | 455 | *ret = TAKE_PTR(q); |
45ec7efb LP |
456 | |
457 | return 0; | |
458 | } |