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
55 #include <netinet/in.h>
56 #include <arpa/inet.h>
58 #include "getrrsetbyname.h"
60 #if defined(HAVE_DECL_H_ERRNO) && !HAVE_DECL_H_ERRNO
64 /* We don't need multithread support here */
65 #ifdef _THREAD_PRIVATE
66 # undef _THREAD_PRIVATE
68 #define _THREAD_PRIVATE(a,b,c) (c)
70 /* to avoid conflicts where a platform already has _res */
74 #define _res _compat_res
76 struct __res_state _res;
78 /* Necessary functions and macros */
81 * Inline versions of get/put short/long. Pointer is advanced.
83 * These macros demonstrate the property of C whereby it can be
84 * portable or it can be elegant but rarely both.
95 #define GETSHORT(s, cp) { \
96 register u_char *t_cp = (u_char *)(cp); \
97 (s) = ((u_int16_t)t_cp[0] << 8) \
98 | ((u_int16_t)t_cp[1]) \
105 #define GETLONG(l, cp) { \
106 register u_char *t_cp = (u_char *)(cp); \
107 (l) = ((u_int32_t)t_cp[0] << 24) \
108 | ((u_int32_t)t_cp[1] << 16) \
109 | ((u_int32_t)t_cp[2] << 8) \
110 | ((u_int32_t)t_cp[3]) \
117 * Routines to insert/extract short/long's.
120 #ifndef HAVE__GETSHORT
123 register const u_char *msgp;
125 register u_int16_t u;
130 #elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
131 u_int16_t _getshort(register const u_char *);
134 #ifndef HAVE__GETLONG
137 register const u_char *msgp;
139 register u_int32_t u;
144 #elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
145 u_int32_t _getlong(register const u_char *);
150 #define ANSWER_BUFFER_SIZE 1024*64
156 struct dns_query *next;
169 struct dns_response {
171 struct dns_query *query;
172 struct dns_rr *answer;
173 struct dns_rr *authority;
174 struct dns_rr *additional;
177 static struct dns_response *parse_dns_response(const u_char *, int);
178 static struct dns_query *parse_dns_qsection(const u_char *, int,
179 const u_char **, int);
180 static struct dns_rr *parse_dns_rrsection(const u_char *, int, const u_char **,
183 static void free_dns_query(struct dns_query *);
184 static void free_dns_rr(struct dns_rr *);
185 static void free_dns_response(struct dns_response *);
187 static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
190 getrrsetbyname(const char *hostname, unsigned int rdclass,
191 unsigned int rdtype, unsigned int flags,
192 struct rrsetinfo **res)
194 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
196 struct rrsetinfo *rrset = NULL;
197 struct dns_response *response = NULL;
199 struct rdatainfo *rdata;
201 unsigned int index_ans, index_sig;
202 u_char answer[ANSWER_BUFFER_SIZE];
204 /* check for invalid class and type */
205 if (rdclass > 0xffff || rdtype > 0xffff) {
206 result = ERRSET_INVAL;
210 /* don't allow queries of class or type ANY */
211 if (rdclass == 0xff || rdtype == 0xff) {
212 result = ERRSET_INVAL;
216 /* don't allow flags yet, unimplemented */
218 result = ERRSET_INVAL;
222 /* initialize resolver */
223 if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
224 result = ERRSET_FAIL;
229 _resp->options |= RES_DEBUG;
232 #ifdef RES_USE_DNSSEC
233 /* turn on DNSSEC if EDNS0 is configured */
234 if (_resp->options & RES_USE_EDNS0)
235 _resp->options |= RES_USE_DNSSEC;
236 #endif /* RES_USE_DNSEC */
239 length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
240 answer, sizeof(answer));
244 result = ERRSET_NONAME;
247 result = ERRSET_NODATA;
250 result = ERRSET_FAIL;
256 response = parse_dns_response(answer, length);
257 if (response == NULL) {
258 result = ERRSET_FAIL;
262 if (response->header.qdcount != 1) {
263 result = ERRSET_FAIL;
267 /* initialize rrset */
268 rrset = calloc(1, sizeof(struct rrsetinfo));
270 result = ERRSET_NOMEMORY;
273 rrset->rri_rdclass = response->query->class;
274 rrset->rri_rdtype = response->query->type;
275 rrset->rri_ttl = response->answer->ttl;
276 rrset->rri_nrdatas = response->header.ancount;
278 #ifdef HAVE_HEADER_AD
279 /* check for authenticated data */
280 if (response->header.ad == 1)
281 rrset->rri_flags |= RRSET_VALIDATED;
284 /* copy name from answer section */
285 rrset->rri_name = strdup(response->answer->name);
286 if (rrset->rri_name == NULL) {
287 result = ERRSET_NOMEMORY;
292 rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
294 rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
297 /* allocate memory for answers */
298 rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
299 sizeof(struct rdatainfo));
300 if (rrset->rri_rdatas == NULL) {
301 result = ERRSET_NOMEMORY;
305 /* allocate memory for signatures */
306 rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
307 if (rrset->rri_sigs == NULL) {
308 result = ERRSET_NOMEMORY;
312 /* copy answers & signatures */
313 for (rr = response->answer, index_ans = 0, index_sig = 0;
318 if (rr->class == rrset->rri_rdclass &&
319 rr->type == rrset->rri_rdtype)
320 rdata = &rrset->rri_rdatas[index_ans++];
322 if (rr->class == rrset->rri_rdclass &&
324 rdata = &rrset->rri_sigs[index_sig++];
327 rdata->rdi_length = rr->size;
328 rdata->rdi_data = malloc(rr->size);
330 if (rdata->rdi_data == NULL) {
331 result = ERRSET_NOMEMORY;
334 memcpy(rdata->rdi_data, rr->rdata, rr->size);
337 free_dns_response(response);
340 return (ERRSET_SUCCESS);
345 if (response != NULL)
346 free_dns_response(response);
351 freerrset(struct rrsetinfo *rrset)
358 if (rrset->rri_rdatas) {
359 for (i = 0; i < rrset->rri_nrdatas; i++) {
360 if (rrset->rri_rdatas[i].rdi_data == NULL)
362 free(rrset->rri_rdatas[i].rdi_data);
364 free(rrset->rri_rdatas);
367 if (rrset->rri_sigs) {
368 for (i = 0; i < rrset->rri_nsigs; i++) {
369 if (rrset->rri_sigs[i].rdi_data == NULL)
371 free(rrset->rri_sigs[i].rdi_data);
373 free(rrset->rri_sigs);
377 free(rrset->rri_name);
382 * DNS response parsing routines
384 static struct dns_response *
385 parse_dns_response(const u_char *answer, int size)
387 struct dns_response *resp;
390 /* allocate memory for the response */
391 resp = calloc(1, sizeof(*resp));
395 /* initialize current pointer */
399 memcpy(&resp->header, cp, HFIXEDSZ);
402 /* fix header byte order */
403 resp->header.qdcount = ntohs(resp->header.qdcount);
404 resp->header.ancount = ntohs(resp->header.ancount);
405 resp->header.nscount = ntohs(resp->header.nscount);
406 resp->header.arcount = ntohs(resp->header.arcount);
408 /* there must be at least one query */
409 if (resp->header.qdcount < 1) {
410 free_dns_response(resp);
414 /* parse query section */
415 resp->query = parse_dns_qsection(answer, size, &cp,
416 resp->header.qdcount);
417 if (resp->header.qdcount && resp->query == NULL) {
418 free_dns_response(resp);
422 /* parse answer section */
423 resp->answer = parse_dns_rrsection(answer, size, &cp,
424 resp->header.ancount);
425 if (resp->header.ancount && resp->answer == NULL) {
426 free_dns_response(resp);
430 /* parse authority section */
431 resp->authority = parse_dns_rrsection(answer, size, &cp,
432 resp->header.nscount);
433 if (resp->header.nscount && resp->authority == NULL) {
434 free_dns_response(resp);
438 /* parse additional section */
439 resp->additional = parse_dns_rrsection(answer, size, &cp,
440 resp->header.arcount);
441 if (resp->header.arcount && resp->additional == NULL) {
442 free_dns_response(resp);
449 static struct dns_query *
450 parse_dns_qsection(const u_char *answer, int size, const u_char **cp, int count)
452 struct dns_query *head, *curr, *prev;
456 for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
458 /* allocate and initialize struct */
459 curr = calloc(1, sizeof(struct dns_query));
461 free_dns_query(head);
470 length = dn_expand(answer, answer + size, *cp, name,
473 free_dns_query(head);
476 curr->name = strdup(name);
477 if (curr->name == NULL) {
478 free_dns_query(head);
484 curr->type = _getshort(*cp);
488 curr->class = _getshort(*cp);
495 static struct dns_rr *
496 parse_dns_rrsection(const u_char *answer, int size, const u_char **cp,
499 struct dns_rr *head, *curr, *prev;
503 for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
505 /* allocate and initialize struct */
506 curr = calloc(1, sizeof(struct dns_rr));
517 length = dn_expand(answer, answer + size, *cp, name,
523 curr->name = strdup(name);
524 if (curr->name == NULL) {
531 curr->type = _getshort(*cp);
535 curr->class = _getshort(*cp);
539 curr->ttl = _getlong(*cp);
543 curr->size = _getshort(*cp);
547 curr->rdata = malloc(curr->size);
548 if (curr->rdata == NULL) {
552 memcpy(curr->rdata, *cp, curr->size);
560 free_dns_query(struct dns_query *p)
567 free_dns_query(p->next);
572 free_dns_rr(struct dns_rr *p)
581 free_dns_rr(p->next);
586 free_dns_response(struct dns_response *p)
591 free_dns_query(p->query);
592 free_dns_rr(p->answer);
593 free_dns_rr(p->authority);
594 free_dns_rr(p->additional);
599 count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
604 if (p->class == class && p->type == type)
612 #endif /* !defined(HAVE_GETRRSETBYNAME) */