1 /* $OpenBSD: getrrsetbyname.c,v 1.10 2005/03/30 02:58:28 tedu Exp $ */
4 * Copyright (c) 2001 Jakob Schlyter. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 * Portions Copyright (c) 1999-2001 Internet Software Consortium.
32 * Permission to use, copy, modify, and distribute this software for any
33 * purpose with or without fee is hereby granted, provided that the above
34 * copyright notice and this permission notice appear in all copies.
36 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
37 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
39 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
40 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
41 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
42 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
43 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
46 /* OPENBSD ORIGINAL: lib/libc/net/getrrsetbyname.c */
50 #ifndef HAVE_GETRRSETBYNAME
52 #include "getrrsetbyname.h"
54 #if defined(HAVE_DECL_H_ERRNO) && !HAVE_DECL_H_ERRNO
58 /* We don't need multithread support here */
59 #ifdef _THREAD_PRIVATE
60 # undef _THREAD_PRIVATE
62 #define _THREAD_PRIVATE(a,b,c) (c)
64 /* to avoid conflicts where a platform already has _res */
68 #define _res _compat_res
70 struct __res_state _res;
72 /* Necessary functions and macros */
75 * Inline versions of get/put short/long. Pointer is advanced.
77 * These macros demonstrate the property of C whereby it can be
78 * portable or it can be elegant but rarely both.
89 #define GETSHORT(s, cp) { \
90 register u_char *t_cp = (u_char *)(cp); \
91 (s) = ((u_int16_t)t_cp[0] << 8) \
92 | ((u_int16_t)t_cp[1]) \
99 #define GETLONG(l, cp) { \
100 register u_char *t_cp = (u_char *)(cp); \
101 (l) = ((u_int32_t)t_cp[0] << 24) \
102 | ((u_int32_t)t_cp[1] << 16) \
103 | ((u_int32_t)t_cp[2] << 8) \
104 | ((u_int32_t)t_cp[3]) \
111 * Routines to insert/extract short/long's.
114 #ifndef HAVE__GETSHORT
117 register const u_char *msgp;
119 register u_int16_t u;
124 #elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
125 u_int16_t _getshort(register const u_char *);
128 #ifndef HAVE__GETLONG
131 register const u_char *msgp;
133 register u_int32_t u;
138 #elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
139 u_int32_t _getlong(register const u_char *);
144 #define ANSWER_BUFFER_SIZE 1024*64
150 struct dns_query *next;
163 struct dns_response {
165 struct dns_query *query;
166 struct dns_rr *answer;
167 struct dns_rr *authority;
168 struct dns_rr *additional;
171 static struct dns_response *parse_dns_response(const u_char *, int);
172 static struct dns_query *parse_dns_qsection(const u_char *, int,
173 const u_char **, int);
174 static struct dns_rr *parse_dns_rrsection(const u_char *, int, const u_char **,
177 static void free_dns_query(struct dns_query *);
178 static void free_dns_rr(struct dns_rr *);
179 static void free_dns_response(struct dns_response *);
181 static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
184 getrrsetbyname(const char *hostname, unsigned int rdclass,
185 unsigned int rdtype, unsigned int flags,
186 struct rrsetinfo **res)
188 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
190 struct rrsetinfo *rrset = NULL;
191 struct dns_response *response = NULL;
193 struct rdatainfo *rdata;
195 unsigned int index_ans, index_sig;
196 u_char answer[ANSWER_BUFFER_SIZE];
198 /* check for invalid class and type */
199 if (rdclass > 0xffff || rdtype > 0xffff) {
200 result = ERRSET_INVAL;
204 /* don't allow queries of class or type ANY */
205 if (rdclass == 0xff || rdtype == 0xff) {
206 result = ERRSET_INVAL;
210 /* don't allow flags yet, unimplemented */
212 result = ERRSET_INVAL;
216 /* initialize resolver */
217 if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
218 result = ERRSET_FAIL;
223 _resp->options |= RES_DEBUG;
226 #ifdef RES_USE_DNSSEC
227 /* turn on DNSSEC if EDNS0 is configured */
228 if (_resp->options & RES_USE_EDNS0)
229 _resp->options |= RES_USE_DNSSEC;
230 #endif /* RES_USE_DNSEC */
233 length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
234 answer, sizeof(answer));
238 result = ERRSET_NONAME;
241 result = ERRSET_NODATA;
244 result = ERRSET_FAIL;
250 response = parse_dns_response(answer, length);
251 if (response == NULL) {
252 result = ERRSET_FAIL;
256 if (response->header.qdcount != 1) {
257 result = ERRSET_FAIL;
261 /* initialize rrset */
262 rrset = calloc(1, sizeof(struct rrsetinfo));
264 result = ERRSET_NOMEMORY;
267 rrset->rri_rdclass = response->query->class;
268 rrset->rri_rdtype = response->query->type;
269 rrset->rri_ttl = response->answer->ttl;
270 rrset->rri_nrdatas = response->header.ancount;
272 #ifdef HAVE_HEADER_AD
273 /* check for authenticated data */
274 if (response->header.ad == 1)
275 rrset->rri_flags |= RRSET_VALIDATED;
278 /* copy name from answer section */
279 rrset->rri_name = strdup(response->answer->name);
280 if (rrset->rri_name == NULL) {
281 result = ERRSET_NOMEMORY;
286 rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
288 rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
291 /* allocate memory for answers */
292 rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
293 sizeof(struct rdatainfo));
294 if (rrset->rri_rdatas == NULL) {
295 result = ERRSET_NOMEMORY;
299 /* allocate memory for signatures */
300 rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
301 if (rrset->rri_sigs == NULL) {
302 result = ERRSET_NOMEMORY;
306 /* copy answers & signatures */
307 for (rr = response->answer, index_ans = 0, index_sig = 0;
312 if (rr->class == rrset->rri_rdclass &&
313 rr->type == rrset->rri_rdtype)
314 rdata = &rrset->rri_rdatas[index_ans++];
316 if (rr->class == rrset->rri_rdclass &&
318 rdata = &rrset->rri_sigs[index_sig++];
321 rdata->rdi_length = rr->size;
322 rdata->rdi_data = malloc(rr->size);
324 if (rdata->rdi_data == NULL) {
325 result = ERRSET_NOMEMORY;
328 memcpy(rdata->rdi_data, rr->rdata, rr->size);
331 free_dns_response(response);
334 return (ERRSET_SUCCESS);
339 if (response != NULL)
340 free_dns_response(response);
345 freerrset(struct rrsetinfo *rrset)
352 if (rrset->rri_rdatas) {
353 for (i = 0; i < rrset->rri_nrdatas; i++) {
354 if (rrset->rri_rdatas[i].rdi_data == NULL)
356 free(rrset->rri_rdatas[i].rdi_data);
358 free(rrset->rri_rdatas);
361 if (rrset->rri_sigs) {
362 for (i = 0; i < rrset->rri_nsigs; i++) {
363 if (rrset->rri_sigs[i].rdi_data == NULL)
365 free(rrset->rri_sigs[i].rdi_data);
367 free(rrset->rri_sigs);
371 free(rrset->rri_name);
376 * DNS response parsing routines
378 static struct dns_response *
379 parse_dns_response(const u_char *answer, int size)
381 struct dns_response *resp;
384 /* allocate memory for the response */
385 resp = calloc(1, sizeof(*resp));
389 /* initialize current pointer */
393 memcpy(&resp->header, cp, HFIXEDSZ);
396 /* fix header byte order */
397 resp->header.qdcount = ntohs(resp->header.qdcount);
398 resp->header.ancount = ntohs(resp->header.ancount);
399 resp->header.nscount = ntohs(resp->header.nscount);
400 resp->header.arcount = ntohs(resp->header.arcount);
402 /* there must be at least one query */
403 if (resp->header.qdcount < 1) {
404 free_dns_response(resp);
408 /* parse query section */
409 resp->query = parse_dns_qsection(answer, size, &cp,
410 resp->header.qdcount);
411 if (resp->header.qdcount && resp->query == NULL) {
412 free_dns_response(resp);
416 /* parse answer section */
417 resp->answer = parse_dns_rrsection(answer, size, &cp,
418 resp->header.ancount);
419 if (resp->header.ancount && resp->answer == NULL) {
420 free_dns_response(resp);
424 /* parse authority section */
425 resp->authority = parse_dns_rrsection(answer, size, &cp,
426 resp->header.nscount);
427 if (resp->header.nscount && resp->authority == NULL) {
428 free_dns_response(resp);
432 /* parse additional section */
433 resp->additional = parse_dns_rrsection(answer, size, &cp,
434 resp->header.arcount);
435 if (resp->header.arcount && resp->additional == NULL) {
436 free_dns_response(resp);
443 static struct dns_query *
444 parse_dns_qsection(const u_char *answer, int size, const u_char **cp, int count)
446 struct dns_query *head, *curr, *prev;
450 for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
452 /* allocate and initialize struct */
453 curr = calloc(1, sizeof(struct dns_query));
455 free_dns_query(head);
464 length = dn_expand(answer, answer + size, *cp, name,
467 free_dns_query(head);
470 curr->name = strdup(name);
471 if (curr->name == NULL) {
472 free_dns_query(head);
478 curr->type = _getshort(*cp);
482 curr->class = _getshort(*cp);
489 static struct dns_rr *
490 parse_dns_rrsection(const u_char *answer, int size, const u_char **cp,
493 struct dns_rr *head, *curr, *prev;
497 for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
499 /* allocate and initialize struct */
500 curr = calloc(1, sizeof(struct dns_rr));
511 length = dn_expand(answer, answer + size, *cp, name,
517 curr->name = strdup(name);
518 if (curr->name == NULL) {
525 curr->type = _getshort(*cp);
529 curr->class = _getshort(*cp);
533 curr->ttl = _getlong(*cp);
537 curr->size = _getshort(*cp);
541 curr->rdata = malloc(curr->size);
542 if (curr->rdata == NULL) {
546 memcpy(curr->rdata, *cp, curr->size);
554 free_dns_query(struct dns_query *p)
561 free_dns_query(p->next);
566 free_dns_rr(struct dns_rr *p)
575 free_dns_rr(p->next);
580 free_dns_response(struct dns_response *p)
585 free_dns_query(p->query);
586 free_dns_rr(p->answer);
587 free_dns_rr(p->authority);
588 free_dns_rr(p->additional);
593 count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
598 if (p->class == class && p->type == type)
606 #endif /* !defined(HAVE_GETRRSETBYNAME) */