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74b2466e 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 "utf8.h" | |
c73ce96b | 23 | #include "util.h" |
74b2466e LP |
24 | #include "resolved-dns-domain.h" |
25 | #include "resolved-dns-packet.h" | |
26 | ||
27 | int dns_packet_new(DnsPacket **ret, size_t mtu) { | |
28 | DnsPacket *p; | |
29 | size_t a; | |
30 | ||
31 | assert(ret); | |
32 | ||
33 | if (mtu <= 0) | |
34 | a = DNS_PACKET_SIZE_START; | |
35 | else | |
36 | a = mtu; | |
37 | ||
38 | if (a < DNS_PACKET_HEADER_SIZE) | |
39 | a = DNS_PACKET_HEADER_SIZE; | |
40 | ||
c73ce96b LP |
41 | /* round up to next page size */ |
42 | a = PAGE_ALIGN(ALIGN(sizeof(DnsPacket)) + a) - ALIGN(sizeof(DnsPacket)); | |
43 | ||
44 | /* make sure we never allocate more than useful */ | |
45 | if (a > DNS_PACKET_SIZE_MAX) | |
46 | a = DNS_PACKET_SIZE_MAX; | |
47 | ||
74b2466e LP |
48 | p = malloc0(ALIGN(sizeof(DnsPacket)) + a); |
49 | if (!p) | |
50 | return -ENOMEM; | |
51 | ||
52 | p->size = p->rindex = DNS_PACKET_HEADER_SIZE; | |
53 | p->allocated = a; | |
54 | p->n_ref = 1; | |
55 | ||
56 | *ret = p; | |
57 | ||
58 | return 0; | |
59 | } | |
60 | ||
61 | int dns_packet_new_query(DnsPacket **ret, size_t mtu) { | |
62 | DnsPacket *p; | |
63 | DnsPacketHeader *h; | |
64 | int r; | |
65 | ||
66 | assert(ret); | |
67 | ||
68 | r = dns_packet_new(&p, mtu); | |
69 | if (r < 0) | |
70 | return r; | |
71 | ||
72 | h = DNS_PACKET_HEADER(p); | |
73 | h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0, 0, 0, 0, 1, 0, 0, 0, 0)); | |
74 | ||
75 | *ret = p; | |
76 | return 0; | |
77 | } | |
78 | ||
79 | DnsPacket *dns_packet_ref(DnsPacket *p) { | |
80 | ||
81 | if (!p) | |
82 | return NULL; | |
83 | ||
84 | assert(p->n_ref > 0); | |
85 | p->n_ref++; | |
86 | return p; | |
87 | } | |
88 | ||
89 | static void dns_packet_free(DnsPacket *p) { | |
90 | char *s; | |
91 | ||
92 | assert(p); | |
93 | ||
94 | while ((s = hashmap_steal_first_key(p->names))) | |
95 | free(s); | |
96 | hashmap_free(p->names); | |
97 | ||
98 | free(p->data); | |
99 | free(p); | |
100 | } | |
101 | ||
102 | DnsPacket *dns_packet_unref(DnsPacket *p) { | |
103 | if (!p) | |
104 | return NULL; | |
105 | ||
106 | assert(p->n_ref > 0); | |
107 | ||
108 | if (p->n_ref == 1) | |
109 | dns_packet_free(p); | |
110 | else | |
111 | p->n_ref--; | |
112 | ||
113 | return NULL; | |
114 | } | |
115 | ||
116 | int dns_packet_validate(DnsPacket *p) { | |
117 | assert(p); | |
118 | ||
119 | if (p->size < DNS_PACKET_HEADER_SIZE) | |
120 | return -EBADMSG; | |
121 | ||
c73ce96b LP |
122 | if (p->size > DNS_PACKET_SIZE_MAX) |
123 | return -EBADMSG; | |
124 | ||
74b2466e LP |
125 | return 0; |
126 | } | |
127 | ||
128 | int dns_packet_validate_reply(DnsPacket *p) { | |
74b2466e LP |
129 | int r; |
130 | ||
131 | assert(p); | |
132 | ||
133 | r = dns_packet_validate(p); | |
134 | if (r < 0) | |
135 | return r; | |
136 | ||
3cb10d3a | 137 | if (DNS_PACKET_QR(p) == 0) |
74b2466e LP |
138 | return -EBADMSG; |
139 | ||
3cb10d3a | 140 | if (DNS_PACKET_OPCODE(p) != 0) |
74b2466e LP |
141 | return -EBADMSG; |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | static int dns_packet_extend(DnsPacket *p, size_t add, void **ret, size_t *start) { | |
147 | assert(p); | |
148 | ||
c73ce96b LP |
149 | if (p->size + add > p->allocated) { |
150 | size_t a; | |
151 | ||
152 | a = PAGE_ALIGN((p->size + add) * 2); | |
153 | if (a > DNS_PACKET_SIZE_MAX) | |
154 | a = DNS_PACKET_SIZE_MAX; | |
155 | ||
156 | if (p->size + add > a) | |
157 | return -EMSGSIZE; | |
158 | ||
159 | if (p->data) { | |
160 | void *d; | |
161 | ||
162 | d = realloc(p->data, a); | |
163 | if (!d) | |
164 | return -ENOMEM; | |
165 | ||
166 | p->data = d; | |
167 | } else { | |
168 | p->data = malloc(a); | |
169 | if (!p->data) | |
170 | return -ENOMEM; | |
171 | ||
172 | memcpy(p->data, (uint8_t*) p + ALIGN(sizeof(DnsPacket)), p->size); | |
173 | memzero((uint8_t*) p->data + p->size, a - p->size); | |
174 | } | |
175 | ||
176 | p->allocated = a; | |
177 | } | |
74b2466e LP |
178 | |
179 | if (start) | |
180 | *start = p->size; | |
181 | ||
182 | if (ret) | |
183 | *ret = (uint8_t*) DNS_PACKET_DATA(p) + p->size; | |
184 | ||
185 | p->size += add; | |
186 | return 0; | |
187 | } | |
188 | ||
189 | static void dns_packet_truncate(DnsPacket *p, size_t sz) { | |
190 | Iterator i; | |
191 | char *s; | |
192 | void *n; | |
193 | ||
194 | assert(p); | |
195 | ||
196 | if (p->size <= sz) | |
197 | return; | |
198 | ||
199 | HASHMAP_FOREACH_KEY(s, n, p->names, i) { | |
200 | ||
201 | if (PTR_TO_SIZE(n) < sz) | |
202 | continue; | |
203 | ||
204 | hashmap_remove(p->names, s); | |
205 | free(s); | |
206 | } | |
207 | ||
208 | p->size = sz; | |
209 | } | |
210 | ||
211 | int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start) { | |
212 | void *d; | |
213 | int r; | |
214 | ||
215 | assert(p); | |
216 | ||
217 | r = dns_packet_extend(p, sizeof(uint8_t), &d, start); | |
218 | if (r < 0) | |
219 | return r; | |
220 | ||
221 | ((uint8_t*) d)[0] = v; | |
222 | ||
223 | return 0; | |
224 | } | |
225 | ||
226 | int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start) { | |
227 | void *d; | |
228 | int r; | |
229 | ||
230 | assert(p); | |
231 | ||
232 | r = dns_packet_extend(p, sizeof(uint16_t), &d, start); | |
233 | if (r < 0) | |
234 | return r; | |
235 | ||
236 | ((uint8_t*) d)[0] = (uint8_t) (v >> 8); | |
237 | ((uint8_t*) d)[1] = (uint8_t) (v & 255); | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start) { | |
243 | void *d; | |
244 | size_t l; | |
245 | int r; | |
246 | ||
247 | assert(p); | |
248 | assert(s); | |
249 | ||
250 | l = strlen(s); | |
251 | if (l > 255) | |
252 | return -E2BIG; | |
253 | ||
254 | r = dns_packet_extend(p, 1 + l, &d, start); | |
255 | if (r < 0) | |
256 | return r; | |
257 | ||
258 | ((uint8_t*) d)[0] = (uint8_t) l; | |
259 | memcpy(((uint8_t*) d) + 1, s, l); | |
260 | ||
261 | return 0; | |
262 | } | |
263 | ||
264 | int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, size_t *start) { | |
265 | void *w; | |
266 | int r; | |
267 | ||
268 | assert(p); | |
269 | assert(d); | |
270 | ||
271 | if (l > DNS_LABEL_MAX) | |
272 | return -E2BIG; | |
273 | ||
274 | r = dns_packet_extend(p, 1 + l, &w, start); | |
275 | if (r < 0) | |
276 | return r; | |
277 | ||
278 | ((uint8_t*) w)[0] = (uint8_t) l; | |
279 | memcpy(((uint8_t*) w) + 1, d, l); | |
280 | ||
281 | return 0; | |
282 | } | |
283 | ||
284 | int dns_packet_append_name(DnsPacket *p, const char *name, size_t *start) { | |
285 | size_t saved_size; | |
286 | int r; | |
287 | ||
288 | assert(p); | |
289 | assert(name); | |
290 | ||
291 | saved_size = p->size; | |
292 | ||
293 | while (*name) { | |
294 | _cleanup_free_ char *s = NULL; | |
295 | char label[DNS_LABEL_MAX]; | |
296 | size_t n; | |
297 | ||
298 | n = PTR_TO_SIZE(hashmap_get(p->names, name)); | |
299 | if (n > 0) { | |
300 | assert(n < p->size); | |
301 | ||
302 | if (n < 0x4000) { | |
303 | r = dns_packet_append_uint16(p, 0xC000 | n, NULL); | |
304 | if (r < 0) | |
305 | goto fail; | |
306 | ||
307 | goto done; | |
308 | } | |
309 | } | |
310 | ||
311 | s = strdup(name); | |
312 | if (!s) { | |
313 | r = -ENOMEM; | |
314 | goto fail; | |
315 | } | |
316 | ||
317 | r = dns_label_unescape(&name, label, sizeof(label)); | |
318 | if (r < 0) | |
319 | goto fail; | |
320 | ||
321 | r = dns_packet_append_label(p, label, r, &n); | |
322 | if (r < 0) | |
323 | goto fail; | |
324 | ||
325 | r = hashmap_ensure_allocated(&p->names, dns_name_hash_func, dns_name_compare_func); | |
326 | if (r < 0) | |
327 | goto fail; | |
328 | ||
329 | r = hashmap_put(p->names, s, SIZE_TO_PTR(n)); | |
330 | if (r < 0) | |
331 | goto fail; | |
332 | ||
333 | s = NULL; | |
334 | } | |
335 | ||
336 | r = dns_packet_append_uint8(p, 0, NULL); | |
337 | if (r < 0) | |
338 | return r; | |
339 | ||
340 | done: | |
341 | if (start) | |
342 | *start = saved_size; | |
343 | ||
344 | return 0; | |
345 | ||
346 | fail: | |
347 | dns_packet_truncate(p, saved_size); | |
348 | return r; | |
349 | } | |
350 | ||
351 | int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *k, size_t *start) { | |
352 | size_t saved_size; | |
353 | int r; | |
354 | ||
355 | assert(p); | |
356 | assert(k); | |
357 | ||
358 | saved_size = p->size; | |
359 | ||
360 | r = dns_packet_append_name(p, k->name, NULL); | |
361 | if (r < 0) | |
362 | goto fail; | |
363 | ||
364 | r = dns_packet_append_uint16(p, k->type, NULL); | |
365 | if (r < 0) | |
366 | goto fail; | |
367 | ||
368 | r = dns_packet_append_uint16(p, k->class, NULL); | |
369 | if (r < 0) | |
370 | goto fail; | |
371 | ||
372 | if (start) | |
373 | *start = saved_size; | |
374 | ||
375 | return 0; | |
376 | ||
377 | fail: | |
378 | dns_packet_truncate(p, saved_size); | |
379 | return r; | |
380 | } | |
381 | ||
382 | int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start) { | |
383 | assert(p); | |
384 | ||
385 | if (p->rindex + sz > p->size) | |
386 | return -EMSGSIZE; | |
387 | ||
388 | if (ret) | |
389 | *ret = (uint8_t*) DNS_PACKET_DATA(p) + p->rindex; | |
390 | ||
391 | if (start) | |
392 | *start = p->rindex; | |
393 | ||
394 | p->rindex += sz; | |
395 | return 0; | |
396 | } | |
397 | ||
398 | static void dns_packet_rewind(DnsPacket *p, size_t idx) { | |
399 | assert(p); | |
400 | assert(idx <= p->size); | |
401 | assert(idx >= DNS_PACKET_HEADER_SIZE); | |
402 | ||
403 | p->rindex = idx; | |
404 | } | |
405 | ||
406 | int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start) { | |
407 | const void *d; | |
408 | int r; | |
409 | ||
410 | assert(p); | |
411 | ||
412 | r = dns_packet_read(p, sizeof(uint8_t), &d, start); | |
413 | if (r < 0) | |
414 | return r; | |
415 | ||
416 | *ret = ((uint8_t*) d)[0]; | |
417 | return 0; | |
418 | } | |
419 | ||
420 | int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start) { | |
421 | const void *d; | |
422 | int r; | |
423 | ||
424 | assert(p); | |
425 | ||
426 | r = dns_packet_read(p, sizeof(uint16_t), &d, start); | |
427 | if (r < 0) | |
428 | return r; | |
429 | ||
430 | *ret = (((uint16_t) ((uint8_t*) d)[0]) << 8) | | |
431 | ((uint16_t) ((uint8_t*) d)[1]); | |
432 | return 0; | |
433 | } | |
434 | ||
435 | int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start) { | |
436 | const void *d; | |
437 | int r; | |
438 | ||
439 | assert(p); | |
440 | ||
441 | r = dns_packet_read(p, sizeof(uint32_t), &d, start); | |
442 | if (r < 0) | |
443 | return r; | |
444 | ||
445 | *ret = (((uint32_t) ((uint8_t*) d)[0]) << 24) | | |
446 | (((uint32_t) ((uint8_t*) d)[1]) << 16) | | |
447 | (((uint32_t) ((uint8_t*) d)[2]) << 8) | | |
448 | ((uint32_t) ((uint8_t*) d)[3]); | |
449 | ||
450 | return 0; | |
451 | } | |
452 | ||
453 | int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start) { | |
454 | size_t saved_rindex; | |
455 | const void *d; | |
456 | char *t; | |
457 | uint8_t c; | |
458 | int r; | |
459 | ||
460 | assert(p); | |
461 | ||
462 | saved_rindex = p->rindex; | |
463 | ||
464 | r = dns_packet_read_uint8(p, &c, NULL); | |
465 | if (r < 0) | |
466 | goto fail; | |
467 | ||
468 | r = dns_packet_read(p, c, &d, NULL); | |
469 | if (r < 0) | |
470 | goto fail; | |
471 | ||
472 | if (memchr(d, 0, c)) { | |
473 | r = -EBADMSG; | |
474 | goto fail; | |
475 | } | |
476 | ||
477 | t = strndup(d, c); | |
478 | if (!t) { | |
479 | r = -ENOMEM; | |
480 | goto fail; | |
481 | } | |
482 | ||
483 | if (!utf8_is_valid(t)) { | |
484 | free(t); | |
485 | r = -EBADMSG; | |
486 | goto fail; | |
487 | } | |
488 | ||
489 | *ret = t; | |
490 | ||
491 | if (start) | |
492 | *start = saved_rindex; | |
493 | ||
494 | return 0; | |
495 | ||
496 | fail: | |
497 | dns_packet_rewind(p, saved_rindex); | |
498 | return r; | |
499 | } | |
500 | ||
501 | int dns_packet_read_name(DnsPacket *p, char **_ret, size_t *start) { | |
502 | size_t saved_rindex, after_rindex = 0; | |
503 | _cleanup_free_ char *ret = NULL; | |
504 | size_t n = 0, allocated = 0; | |
505 | bool first = true; | |
506 | int r; | |
507 | ||
508 | assert(p); | |
509 | assert(_ret); | |
510 | ||
511 | saved_rindex = p->rindex; | |
512 | ||
513 | for (;;) { | |
514 | uint8_t c, d; | |
515 | ||
516 | r = dns_packet_read_uint8(p, &c, NULL); | |
517 | if (r < 0) | |
518 | goto fail; | |
519 | ||
520 | if (c == 0) | |
521 | /* End of name */ | |
522 | break; | |
523 | else if (c <= 63) { | |
524 | _cleanup_free_ char *t = NULL; | |
525 | const char *label; | |
526 | ||
527 | /* Literal label */ | |
528 | r = dns_packet_read(p, c, (const void**) &label, NULL); | |
529 | if (r < 0) | |
530 | goto fail; | |
531 | ||
532 | r = dns_label_escape(label, c, &t); | |
533 | if (r < 0) | |
534 | goto fail; | |
535 | ||
536 | if (!GREEDY_REALLOC(ret, allocated, n + !first + strlen(t) + 1)) { | |
537 | r = -ENOMEM; | |
538 | goto fail; | |
539 | } | |
540 | ||
541 | if (!first) | |
542 | ret[n++] = '.'; | |
543 | else | |
544 | first = false; | |
545 | ||
546 | memcpy(ret + n, t, c); | |
547 | n += r; | |
548 | continue; | |
549 | } else if ((c & 0xc0) == 0xc0) { | |
550 | uint16_t ptr; | |
551 | ||
552 | /* Pointer */ | |
553 | r = dns_packet_read_uint8(p, &d, NULL); | |
554 | if (r < 0) | |
555 | goto fail; | |
556 | ||
557 | ptr = (uint16_t) (c & ~0xc0) << 8 | (uint16_t) d; | |
558 | if (ptr < DNS_PACKET_HEADER_SIZE || ptr >= saved_rindex) { | |
559 | r = -EBADMSG; | |
560 | goto fail; | |
561 | } | |
562 | ||
563 | if (after_rindex == 0) | |
564 | after_rindex = p->rindex; | |
565 | ||
566 | p->rindex = ptr; | |
567 | } else | |
568 | goto fail; | |
569 | } | |
570 | ||
571 | if (!GREEDY_REALLOC(ret, allocated, n + 1)) { | |
572 | r = -ENOMEM; | |
573 | goto fail; | |
574 | } | |
575 | ||
576 | ret[n] = 0; | |
577 | ||
578 | if (after_rindex != 0) | |
579 | p->rindex= after_rindex; | |
580 | ||
581 | *_ret = ret; | |
582 | ret = NULL; | |
583 | ||
584 | if (start) | |
585 | *start = saved_rindex; | |
586 | ||
587 | return 0; | |
588 | ||
589 | fail: | |
590 | dns_packet_rewind(p, saved_rindex); | |
591 | return r; | |
592 | } | |
593 | ||
594 | int dns_packet_read_key(DnsPacket *p, DnsResourceKey *ret, size_t *start) { | |
595 | _cleanup_(dns_resource_key_free) DnsResourceKey k = {}; | |
596 | size_t saved_rindex; | |
597 | int r; | |
598 | ||
599 | assert(p); | |
600 | assert(ret); | |
601 | ||
602 | saved_rindex = p->rindex; | |
603 | ||
604 | r = dns_packet_read_name(p, &k.name, NULL); | |
605 | if (r < 0) | |
606 | goto fail; | |
607 | ||
608 | r = dns_packet_read_uint16(p, &k.type, NULL); | |
609 | if (r < 0) | |
610 | goto fail; | |
611 | ||
612 | r = dns_packet_read_uint16(p, &k.class, NULL); | |
613 | if (r < 0) | |
614 | goto fail; | |
615 | ||
616 | *ret = k; | |
617 | zero(k); | |
618 | ||
619 | if (start) | |
620 | *start = saved_rindex; | |
621 | ||
622 | return 0; | |
623 | fail: | |
624 | dns_packet_rewind(p, saved_rindex); | |
625 | return r; | |
626 | } | |
627 | ||
628 | int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { | |
4e0296a9 | 629 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr; |
74b2466e LP |
630 | size_t saved_rindex, offset; |
631 | uint16_t rdlength; | |
632 | const void *d; | |
633 | int r; | |
634 | ||
635 | assert(p); | |
636 | assert(ret); | |
637 | ||
74b2466e LP |
638 | rr = dns_resource_record_new(); |
639 | if (!rr) | |
4e0296a9 ZJS |
640 | return -ENOMEM; |
641 | ||
642 | saved_rindex = p->rindex; | |
74b2466e LP |
643 | |
644 | r = dns_packet_read_key(p, &rr->key, NULL); | |
645 | if (r < 0) | |
646 | goto fail; | |
647 | ||
648 | r = dns_packet_read_uint32(p, &rr->ttl, NULL); | |
649 | if (r < 0) | |
650 | goto fail; | |
651 | ||
652 | r = dns_packet_read_uint16(p, &rdlength, NULL); | |
653 | if (r < 0) | |
654 | goto fail; | |
655 | ||
656 | if (p->rindex + rdlength > p->size) { | |
657 | r = -EBADMSG; | |
658 | goto fail; | |
659 | } | |
660 | ||
661 | offset = p->rindex; | |
662 | ||
663 | switch (rr->key.type) { | |
664 | ||
665 | case DNS_TYPE_PTR: | |
666 | case DNS_TYPE_NS: | |
667 | case DNS_TYPE_CNAME: | |
668 | r = dns_packet_read_name(p, &rr->ptr.name, NULL); | |
669 | break; | |
670 | ||
671 | case DNS_TYPE_HINFO: | |
672 | r = dns_packet_read_string(p, &rr->hinfo.cpu, NULL); | |
673 | if (r < 0) | |
674 | goto fail; | |
675 | ||
676 | r = dns_packet_read_string(p, &rr->hinfo.os, NULL); | |
677 | break; | |
678 | ||
679 | case DNS_TYPE_A: | |
680 | r = dns_packet_read(p, sizeof(struct in_addr), &d, NULL); | |
681 | if (r < 0) | |
682 | goto fail; | |
683 | ||
684 | memcpy(&rr->a.in_addr, d, sizeof(struct in_addr)); | |
685 | break; | |
686 | ||
687 | case DNS_TYPE_AAAA: | |
688 | r = dns_packet_read(p, sizeof(struct in6_addr), &d, NULL); | |
689 | if (r < 0) | |
690 | goto fail; | |
691 | ||
692 | memcpy(&rr->aaaa.in6_addr, d, sizeof(struct in6_addr)); | |
693 | break; | |
694 | ||
695 | default: | |
696 | r = dns_packet_read(p, rdlength, &d, NULL); | |
697 | if (r < 0) | |
698 | goto fail; | |
699 | ||
700 | rr->generic.data = memdup(d, rdlength); | |
701 | if (!rr->generic.data) { | |
702 | r = -ENOMEM; | |
703 | goto fail; | |
704 | } | |
705 | ||
706 | rr->generic.size = rdlength; | |
707 | break; | |
708 | } | |
709 | if (r < 0) | |
710 | goto fail; | |
711 | if (p->rindex != offset + rdlength) { | |
712 | r = -EBADMSG; | |
713 | goto fail; | |
714 | } | |
715 | ||
716 | *ret = rr; | |
717 | rr = NULL; | |
718 | ||
719 | if (start) | |
720 | *start = saved_rindex; | |
721 | ||
722 | return 0; | |
723 | fail: | |
724 | dns_packet_rewind(p, saved_rindex); | |
725 | return r; | |
726 | } | |
727 | ||
728 | int dns_packet_skip_question(DnsPacket *p) { | |
729 | int r; | |
730 | ||
731 | unsigned i, n; | |
732 | assert(p); | |
733 | ||
3cb10d3a | 734 | n = DNS_PACKET_QDCOUNT(p); |
74b2466e LP |
735 | for (i = 0; i < n; i++) { |
736 | _cleanup_(dns_resource_key_free) DnsResourceKey key = {}; | |
737 | ||
738 | r = dns_packet_read_key(p, &key, NULL); | |
739 | if (r < 0) | |
740 | return r; | |
741 | } | |
742 | ||
743 | return 0; | |
744 | } | |
745 | ||
746 | static const char* const dns_rcode_table[_DNS_RCODE_MAX_DEFINED] = { | |
747 | [DNS_RCODE_SUCCESS] = "SUCCESS", | |
748 | [DNS_RCODE_FORMERR] = "FORMERR", | |
749 | [DNS_RCODE_SERVFAIL] = "SERVFAIL", | |
750 | [DNS_RCODE_NXDOMAIN] = "NXDOMAIN", | |
751 | [DNS_RCODE_NOTIMP] = "NOTIMP", | |
752 | [DNS_RCODE_REFUSED] = "REFUSED", | |
753 | [DNS_RCODE_YXDOMAIN] = "YXDOMAIN", | |
754 | [DNS_RCODE_YXRRSET] = "YRRSET", | |
755 | [DNS_RCODE_NXRRSET] = "NXRRSET", | |
756 | [DNS_RCODE_NOTAUTH] = "NOTAUTH", | |
757 | [DNS_RCODE_NOTZONE] = "NOTZONE", | |
758 | [DNS_RCODE_BADVERS] = "BADVERS", | |
759 | [DNS_RCODE_BADKEY] = "BADKEY", | |
760 | [DNS_RCODE_BADTIME] = "BADTIME", | |
761 | [DNS_RCODE_BADMODE] = "BADMODE", | |
762 | [DNS_RCODE_BADNAME] = "BADNAME", | |
763 | [DNS_RCODE_BADALG] = "BADALG", | |
764 | [DNS_RCODE_BADTRUNC] = "BADTRUNC", | |
765 | }; | |
766 | DEFINE_STRING_TABLE_LOOKUP(dns_rcode, int); |