Line data Source code
1 : /* SPDX-License-Identifier: LGPL-2.1+ */
2 :
3 : #include "alloc-util.h"
4 : #include "dns-domain.h"
5 : #include "dns-type.h"
6 : #include "resolved-dns-question.h"
7 :
8 0 : DnsQuestion *dns_question_new(size_t n) {
9 : DnsQuestion *q;
10 :
11 0 : assert(n > 0);
12 :
13 0 : q = malloc0(offsetof(DnsQuestion, keys) + sizeof(DnsResourceKey*) * n);
14 0 : if (!q)
15 0 : return NULL;
16 :
17 0 : q->n_ref = 1;
18 0 : q->n_allocated = n;
19 :
20 0 : return q;
21 : }
22 :
23 0 : static DnsQuestion *dns_question_free(DnsQuestion *q) {
24 : size_t i;
25 :
26 0 : assert(q);
27 :
28 0 : for (i = 0; i < q->n_keys; i++)
29 0 : dns_resource_key_unref(q->keys[i]);
30 0 : return mfree(q);
31 : }
32 :
33 1258 : DEFINE_TRIVIAL_REF_UNREF_FUNC(DnsQuestion, dns_question, dns_question_free);
34 :
35 0 : int dns_question_add_raw(DnsQuestion *q, DnsResourceKey *key) {
36 : /* Insert without checking for duplicates. */
37 :
38 0 : assert(key);
39 0 : assert(q);
40 :
41 0 : if (q->n_keys >= q->n_allocated)
42 0 : return -ENOSPC;
43 :
44 0 : q->keys[q->n_keys++] = dns_resource_key_ref(key);
45 0 : return 0;
46 : }
47 :
48 0 : int dns_question_add(DnsQuestion *q, DnsResourceKey *key) {
49 : int r;
50 :
51 0 : assert(key);
52 :
53 0 : if (!q)
54 0 : return -ENOSPC;
55 :
56 0 : for (size_t i = 0; i < q->n_keys; i++) {
57 0 : r = dns_resource_key_equal(q->keys[i], key);
58 0 : if (r < 0)
59 0 : return r;
60 0 : if (r > 0)
61 0 : return 0;
62 : }
63 :
64 0 : return dns_question_add_raw(q, key);
65 : }
66 :
67 0 : int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) {
68 : size_t i;
69 : int r;
70 :
71 0 : assert(rr);
72 :
73 0 : if (!q)
74 0 : return 0;
75 :
76 0 : for (i = 0; i < q->n_keys; i++) {
77 0 : r = dns_resource_key_match_rr(q->keys[i], rr, search_domain);
78 0 : if (r != 0)
79 0 : return r;
80 : }
81 :
82 0 : return 0;
83 : }
84 :
85 0 : int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) {
86 : size_t i;
87 : int r;
88 :
89 0 : assert(rr);
90 :
91 0 : if (!q)
92 0 : return 0;
93 :
94 0 : if (!IN_SET(rr->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME))
95 0 : return 0;
96 :
97 0 : for (i = 0; i < q->n_keys; i++) {
98 : /* For a {C,D}NAME record we can never find a matching {C,D}NAME record */
99 0 : if (!dns_type_may_redirect(q->keys[i]->type))
100 0 : return 0;
101 :
102 0 : r = dns_resource_key_match_cname_or_dname(q->keys[i], rr->key, search_domain);
103 0 : if (r != 0)
104 0 : return r;
105 : }
106 :
107 0 : return 0;
108 : }
109 :
110 0 : int dns_question_is_valid_for_query(DnsQuestion *q) {
111 : const char *name;
112 : size_t i;
113 : int r;
114 :
115 0 : if (!q)
116 0 : return 0;
117 :
118 0 : if (q->n_keys <= 0)
119 0 : return 0;
120 :
121 0 : if (q->n_keys > 65535)
122 0 : return 0;
123 :
124 0 : name = dns_resource_key_name(q->keys[0]);
125 0 : if (!name)
126 0 : return 0;
127 :
128 : /* Check that all keys in this question bear the same name */
129 0 : for (i = 0; i < q->n_keys; i++) {
130 0 : assert(q->keys[i]);
131 :
132 0 : if (i > 0) {
133 0 : r = dns_name_equal(dns_resource_key_name(q->keys[i]), name);
134 0 : if (r <= 0)
135 0 : return r;
136 : }
137 :
138 0 : if (!dns_type_is_valid_query(q->keys[i]->type))
139 0 : return 0;
140 : }
141 :
142 0 : return 1;
143 : }
144 :
145 0 : int dns_question_contains(DnsQuestion *a, const DnsResourceKey *k) {
146 : size_t j;
147 : int r;
148 :
149 0 : assert(k);
150 :
151 0 : if (!a)
152 0 : return 0;
153 :
154 0 : for (j = 0; j < a->n_keys; j++) {
155 0 : r = dns_resource_key_equal(a->keys[j], k);
156 0 : if (r != 0)
157 0 : return r;
158 : }
159 :
160 0 : return 0;
161 : }
162 :
163 0 : int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) {
164 : size_t j;
165 : int r;
166 :
167 0 : if (a == b)
168 0 : return 1;
169 :
170 0 : if (!a)
171 0 : return !b || b->n_keys == 0;
172 0 : if (!b)
173 0 : return a->n_keys == 0;
174 :
175 : /* Checks if all keys in a are also contained b, and vice versa */
176 :
177 0 : for (j = 0; j < a->n_keys; j++) {
178 0 : r = dns_question_contains(b, a->keys[j]);
179 0 : if (r <= 0)
180 0 : return r;
181 : }
182 :
183 0 : for (j = 0; j < b->n_keys; j++) {
184 0 : r = dns_question_contains(a, b->keys[j]);
185 0 : if (r <= 0)
186 0 : return r;
187 : }
188 :
189 0 : return 1;
190 : }
191 :
192 0 : int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) {
193 0 : _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL;
194 : DnsResourceKey *key;
195 0 : bool same = true;
196 : int r;
197 :
198 0 : assert(cname);
199 0 : assert(ret);
200 0 : assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME));
201 :
202 0 : if (dns_question_size(q) <= 0) {
203 0 : *ret = NULL;
204 0 : return 0;
205 : }
206 :
207 0 : DNS_QUESTION_FOREACH(key, q) {
208 0 : _cleanup_free_ char *destination = NULL;
209 : const char *d;
210 :
211 0 : if (cname->key->type == DNS_TYPE_CNAME)
212 0 : d = cname->cname.name;
213 : else {
214 0 : r = dns_name_change_suffix(dns_resource_key_name(key), dns_resource_key_name(cname->key), cname->dname.name, &destination);
215 0 : if (r < 0)
216 0 : return r;
217 0 : if (r == 0)
218 0 : continue;
219 :
220 0 : d = destination;
221 : }
222 :
223 0 : r = dns_name_equal(dns_resource_key_name(key), d);
224 0 : if (r < 0)
225 0 : return r;
226 :
227 0 : if (r == 0) {
228 0 : same = false;
229 0 : break;
230 : }
231 : }
232 :
233 : /* Fully the same, indicate we didn't do a thing */
234 0 : if (same) {
235 0 : *ret = NULL;
236 0 : return 0;
237 : }
238 :
239 0 : n = dns_question_new(q->n_keys);
240 0 : if (!n)
241 0 : return -ENOMEM;
242 :
243 : /* Create a new question, and patch in the new name */
244 0 : DNS_QUESTION_FOREACH(key, q) {
245 0 : _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL;
246 :
247 0 : k = dns_resource_key_new_redirect(key, cname);
248 0 : if (!k)
249 0 : return -ENOMEM;
250 :
251 0 : r = dns_question_add(n, k);
252 0 : if (r < 0)
253 0 : return r;
254 : }
255 :
256 0 : *ret = TAKE_PTR(n);
257 :
258 0 : return 1;
259 : }
260 :
261 0 : const char *dns_question_first_name(DnsQuestion *q) {
262 :
263 0 : if (!q)
264 0 : return NULL;
265 :
266 0 : if (q->n_keys < 1)
267 0 : return NULL;
268 :
269 0 : return dns_resource_key_name(q->keys[0]);
270 : }
271 :
272 0 : int dns_question_new_address(DnsQuestion **ret, int family, const char *name, bool convert_idna) {
273 0 : _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
274 0 : _cleanup_free_ char *buf = NULL;
275 : int r;
276 :
277 0 : assert(ret);
278 0 : assert(name);
279 :
280 0 : if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
281 0 : return -EAFNOSUPPORT;
282 :
283 0 : if (convert_idna) {
284 0 : r = dns_name_apply_idna(name, &buf);
285 0 : if (r < 0)
286 0 : return r;
287 0 : if (r > 0 && !streq(name, buf))
288 0 : name = buf;
289 : else
290 : /* We did not manage to create convert the idna name, or it's
291 : * the same as the original name. We assume the caller already
292 : * created an unconverted question, so let's not repeat work
293 : * unnecessarily. */
294 0 : return -EALREADY;
295 : }
296 :
297 0 : q = dns_question_new(family == AF_UNSPEC ? 2 : 1);
298 0 : if (!q)
299 0 : return -ENOMEM;
300 :
301 0 : if (family != AF_INET6) {
302 0 : _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
303 :
304 0 : key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, name);
305 0 : if (!key)
306 0 : return -ENOMEM;
307 :
308 0 : r = dns_question_add(q, key);
309 0 : if (r < 0)
310 0 : return r;
311 : }
312 :
313 0 : if (family != AF_INET) {
314 0 : _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
315 :
316 0 : key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, name);
317 0 : if (!key)
318 0 : return -ENOMEM;
319 :
320 0 : r = dns_question_add(q, key);
321 0 : if (r < 0)
322 0 : return r;
323 : }
324 :
325 0 : *ret = TAKE_PTR(q);
326 :
327 0 : return 0;
328 : }
329 :
330 0 : int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a) {
331 0 : _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
332 0 : _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
333 0 : _cleanup_free_ char *reverse = NULL;
334 : int r;
335 :
336 0 : assert(ret);
337 0 : assert(a);
338 :
339 0 : if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
340 0 : return -EAFNOSUPPORT;
341 :
342 0 : r = dns_name_reverse(family, a, &reverse);
343 0 : if (r < 0)
344 0 : return r;
345 :
346 0 : q = dns_question_new(1);
347 0 : if (!q)
348 0 : return -ENOMEM;
349 :
350 0 : key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse);
351 0 : if (!key)
352 0 : return -ENOMEM;
353 :
354 0 : reverse = NULL;
355 :
356 0 : r = dns_question_add(q, key);
357 0 : if (r < 0)
358 0 : return r;
359 :
360 0 : *ret = TAKE_PTR(q);
361 :
362 0 : return 0;
363 : }
364 :
365 0 : int dns_question_new_service(
366 : DnsQuestion **ret,
367 : const char *service,
368 : const char *type,
369 : const char *domain,
370 : bool with_txt,
371 : bool convert_idna) {
372 :
373 0 : _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
374 0 : _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
375 0 : _cleanup_free_ char *buf = NULL, *joined = NULL;
376 : const char *name;
377 : int r;
378 :
379 0 : assert(ret);
380 :
381 : /* We support three modes of invocation:
382 : *
383 : * 1. Only a domain is specified, in which case we assume a properly encoded SRV RR name, including service
384 : * type and possibly a service name. If specified in this way we assume it's already IDNA converted if
385 : * that's necessary.
386 : *
387 : * 2. Both service type and a domain specified, in which case a normal SRV RR is assumed, without a DNS-SD
388 : * style prefix. In this case we'll IDNA convert the domain, if that's requested.
389 : *
390 : * 3. All three of service name, type and domain are specified, in which case a DNS-SD service is put
391 : * together. The service name is never IDNA converted, and the domain is if requested.
392 : *
393 : * It's not supported to specify a service name without a type, or no domain name.
394 : */
395 :
396 0 : if (!domain)
397 0 : return -EINVAL;
398 :
399 0 : if (type) {
400 0 : if (convert_idna) {
401 0 : r = dns_name_apply_idna(domain, &buf);
402 0 : if (r < 0)
403 0 : return r;
404 0 : if (r > 0)
405 0 : domain = buf;
406 : }
407 :
408 0 : r = dns_service_join(service, type, domain, &joined);
409 0 : if (r < 0)
410 0 : return r;
411 :
412 0 : name = joined;
413 : } else {
414 0 : if (service)
415 0 : return -EINVAL;
416 :
417 0 : name = domain;
418 : }
419 :
420 0 : q = dns_question_new(1 + with_txt);
421 0 : if (!q)
422 0 : return -ENOMEM;
423 :
424 0 : key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_SRV, name);
425 0 : if (!key)
426 0 : return -ENOMEM;
427 :
428 0 : r = dns_question_add(q, key);
429 0 : if (r < 0)
430 0 : return r;
431 :
432 0 : if (with_txt) {
433 0 : dns_resource_key_unref(key);
434 0 : key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_TXT, name);
435 0 : if (!key)
436 0 : return -ENOMEM;
437 :
438 0 : r = dns_question_add(q, key);
439 0 : if (r < 0)
440 0 : return r;
441 : }
442 :
443 0 : *ret = TAKE_PTR(q);
444 :
445 0 : return 0;
446 : }
|
