1 /* $OpenBSD: getrrsetbyname.c,v 1.11 2007/10/11 18:36:41 jakob 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 #ifndef HAVE__RES_EXTERN
71 struct __res_state _res;
74 /* Necessary functions and macros */
77 * Inline versions of get/put short/long. Pointer is advanced.
79 * These macros demonstrate the property of C whereby it can be
80 * portable or it can be elegant but rarely both.
91 #define GETSHORT(s, cp) { \
92 register u_char *t_cp = (u_char *)(cp); \
93 (s) = ((u_int16_t)t_cp[0] << 8) \
94 | ((u_int16_t)t_cp[1]) \
101 #define GETLONG(l, cp) { \
102 register u_char *t_cp = (u_char *)(cp); \
103 (l) = ((u_int32_t)t_cp[0] << 24) \
104 | ((u_int32_t)t_cp[1] << 16) \
105 | ((u_int32_t)t_cp[2] << 8) \
106 | ((u_int32_t)t_cp[3]) \
113 * Routines to insert/extract short/long's.
116 #ifndef HAVE__GETSHORT
119 register const u_char *msgp;
121 register u_int16_t u;
126 #elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
127 u_int16_t _getshort(register const u_char *);
130 #ifndef HAVE__GETLONG
133 register const u_char *msgp;
135 register u_int32_t u;
140 #elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
141 u_int32_t _getlong(register const u_char *);
146 #define ANSWER_BUFFER_SIZE 0xffff
152 struct dns_query *next;
165 struct dns_response {
167 struct dns_query *query;
168 struct dns_rr *answer;
169 struct dns_rr *authority;
170 struct dns_rr *additional;
173 static struct dns_response *parse_dns_response(const u_char *, int);
174 static struct dns_query *parse_dns_qsection(const u_char *, int,
175 const u_char **, int);
176 static struct dns_rr *parse_dns_rrsection(const u_char *, int, const u_char **,
179 static void free_dns_query(struct dns_query *);
180 static void free_dns_rr(struct dns_rr *);
181 static void free_dns_response(struct dns_response *);
183 static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
186 getrrsetbyname(const char *hostname, unsigned int rdclass,
187 unsigned int rdtype, unsigned int flags,
188 struct rrsetinfo **res)
190 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
192 struct rrsetinfo *rrset = NULL;
193 struct dns_response *response = NULL;
195 struct rdatainfo *rdata;
197 unsigned int index_ans, index_sig;
198 u_char answer[ANSWER_BUFFER_SIZE];
200 /* check for invalid class and type */
201 if (rdclass > 0xffff || rdtype > 0xffff) {
202 result = ERRSET_INVAL;
206 /* don't allow queries of class or type ANY */
207 if (rdclass == 0xff || rdtype == 0xff) {
208 result = ERRSET_INVAL;
212 /* don't allow flags yet, unimplemented */
214 result = ERRSET_INVAL;
218 /* initialize resolver */
219 if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
220 result = ERRSET_FAIL;
225 _resp->options |= RES_DEBUG;
228 #ifdef RES_USE_DNSSEC
229 /* turn on DNSSEC if EDNS0 is configured */
230 if (_resp->options & RES_USE_EDNS0)
231 _resp->options |= RES_USE_DNSSEC;
232 #endif /* RES_USE_DNSEC */
235 length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
236 answer, sizeof(answer));
240 result = ERRSET_NONAME;
243 result = ERRSET_NODATA;
246 result = ERRSET_FAIL;
252 response = parse_dns_response(answer, length);
253 if (response == NULL) {
254 result = ERRSET_FAIL;
258 if (response->header.qdcount != 1) {
259 result = ERRSET_FAIL;
263 /* initialize rrset */
264 rrset = calloc(1, sizeof(struct rrsetinfo));
266 result = ERRSET_NOMEMORY;
269 rrset->rri_rdclass = response->query->class;
270 rrset->rri_rdtype = response->query->type;
271 rrset->rri_ttl = response->answer->ttl;
272 rrset->rri_nrdatas = response->header.ancount;
274 #ifdef HAVE_HEADER_AD
275 /* check for authenticated data */
276 if (response->header.ad == 1)
277 rrset->rri_flags |= RRSET_VALIDATED;
280 /* copy name from answer section */
281 rrset->rri_name = strdup(response->answer->name);
282 if (rrset->rri_name == NULL) {
283 result = ERRSET_NOMEMORY;
288 rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
290 rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
293 /* allocate memory for answers */
294 rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
295 sizeof(struct rdatainfo));
296 if (rrset->rri_rdatas == NULL) {
297 result = ERRSET_NOMEMORY;
301 /* allocate memory for signatures */
302 if (rrset->rri_nsigs > 0) {
303 rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
304 if (rrset->rri_sigs == NULL) {
305 result = ERRSET_NOMEMORY;
310 /* copy answers & signatures */
311 for (rr = response->answer, index_ans = 0, index_sig = 0;
316 if (rr->class == rrset->rri_rdclass &&
317 rr->type == rrset->rri_rdtype)
318 rdata = &rrset->rri_rdatas[index_ans++];
320 if (rr->class == rrset->rri_rdclass &&
322 rdata = &rrset->rri_sigs[index_sig++];
325 rdata->rdi_length = rr->size;
326 rdata->rdi_data = malloc(rr->size);
328 if (rdata->rdi_data == NULL) {
329 result = ERRSET_NOMEMORY;
332 memcpy(rdata->rdi_data, rr->rdata, rr->size);
335 free_dns_response(response);
338 return (ERRSET_SUCCESS);
343 if (response != NULL)
344 free_dns_response(response);
349 freerrset(struct rrsetinfo *rrset)
356 if (rrset->rri_rdatas) {
357 for (i = 0; i < rrset->rri_nrdatas; i++) {
358 if (rrset->rri_rdatas[i].rdi_data == NULL)
360 free(rrset->rri_rdatas[i].rdi_data);
362 free(rrset->rri_rdatas);
365 if (rrset->rri_sigs) {
366 for (i = 0; i < rrset->rri_nsigs; i++) {
367 if (rrset->rri_sigs[i].rdi_data == NULL)
369 free(rrset->rri_sigs[i].rdi_data);
371 free(rrset->rri_sigs);
375 free(rrset->rri_name);
380 * DNS response parsing routines
382 static struct dns_response *
383 parse_dns_response(const u_char *answer, int size)
385 struct dns_response *resp;
388 /* allocate memory for the response */
389 resp = calloc(1, sizeof(*resp));
393 /* initialize current pointer */
397 memcpy(&resp->header, cp, HFIXEDSZ);
400 /* fix header byte order */
401 resp->header.qdcount = ntohs(resp->header.qdcount);
402 resp->header.ancount = ntohs(resp->header.ancount);
403 resp->header.nscount = ntohs(resp->header.nscount);
404 resp->header.arcount = ntohs(resp->header.arcount);
406 /* there must be at least one query */
407 if (resp->header.qdcount < 1) {
408 free_dns_response(resp);
412 /* parse query section */
413 resp->query = parse_dns_qsection(answer, size, &cp,
414 resp->header.qdcount);
415 if (resp->header.qdcount && resp->query == NULL) {
416 free_dns_response(resp);
420 /* parse answer section */
421 resp->answer = parse_dns_rrsection(answer, size, &cp,
422 resp->header.ancount);
423 if (resp->header.ancount && resp->answer == NULL) {
424 free_dns_response(resp);
428 /* parse authority section */
429 resp->authority = parse_dns_rrsection(answer, size, &cp,
430 resp->header.nscount);
431 if (resp->header.nscount && resp->authority == NULL) {
432 free_dns_response(resp);
436 /* parse additional section */
437 resp->additional = parse_dns_rrsection(answer, size, &cp,
438 resp->header.arcount);
439 if (resp->header.arcount && resp->additional == NULL) {
440 free_dns_response(resp);
447 static struct dns_query *
448 parse_dns_qsection(const u_char *answer, int size, const u_char **cp, int count)
450 struct dns_query *head, *curr, *prev;
454 for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
456 /* allocate and initialize struct */
457 curr = calloc(1, sizeof(struct dns_query));
459 free_dns_query(head);
468 length = dn_expand(answer, answer + size, *cp, name,
471 free_dns_query(head);
474 curr->name = strdup(name);
475 if (curr->name == NULL) {
476 free_dns_query(head);
482 curr->type = _getshort(*cp);
486 curr->class = _getshort(*cp);
493 static struct dns_rr *
494 parse_dns_rrsection(const u_char *answer, int size, const u_char **cp,
497 struct dns_rr *head, *curr, *prev;
501 for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
503 /* allocate and initialize struct */
504 curr = calloc(1, sizeof(struct dns_rr));
515 length = dn_expand(answer, answer + size, *cp, name,
521 curr->name = strdup(name);
522 if (curr->name == NULL) {
529 curr->type = _getshort(*cp);
533 curr->class = _getshort(*cp);
537 curr->ttl = _getlong(*cp);
541 curr->size = _getshort(*cp);
545 curr->rdata = malloc(curr->size);
546 if (curr->rdata == NULL) {
550 memcpy(curr->rdata, *cp, curr->size);
558 free_dns_query(struct dns_query *p)
565 free_dns_query(p->next);
570 free_dns_rr(struct dns_rr *p)
579 free_dns_rr(p->next);
584 free_dns_response(struct dns_response *p)
589 free_dns_query(p->query);
590 free_dns_rr(p->answer);
591 free_dns_rr(p->authority);
592 free_dns_rr(p->additional);
597 count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
602 if (p->class == class && p->type == type)
610 #endif /* !defined(HAVE_GETRRSETBYNAME) */