1 /* $NetBSD: resolve.c,v 1.4 2014/04/24 14:49:43 pettai Exp $ */
2
3 /*
4 * Copyright (c) 1995 - 2006 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36
37 #include <config.h>
38
39 #include <krb5/roken.h>
40 #ifdef HAVE_ARPA_NAMESER_H
41 #include <arpa/nameser.h>
42 #endif
43 #ifdef HAVE_RESOLV_H
44 #include <resolv.h>
45 #endif
46 #ifdef HAVE_DNS_H
47 #include <dns.h>
48 #endif
49 #include <krb5/resolve.h>
50
51 #include <assert.h>
52
53 #ifdef _AIX /* AIX have broken res_nsearch() in 5.1 (5.0 also ?) */
54 #undef HAVE_RES_NSEARCH
55 #endif
56
57 #define DECL(X) {#X, rk_ns_t_##X}
58
59 static struct stot{
60 const char *name;
61 int type;
62 }stot[] = {
63 DECL(a),
64 DECL(aaaa),
65 DECL(ns),
66 DECL(cname),
67 DECL(soa),
68 DECL(ptr),
69 DECL(mx),
70 DECL(txt),
71 DECL(afsdb),
72 DECL(sig),
73 DECL(key),
74 DECL(srv),
75 DECL(naptr),
76 DECL(sshfp),
77 DECL(ds),
78 {NULL, 0}
79 };
80
81 int _resolve_debug = 0;
82
83 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
rk_dns_string_to_type(const char * name)84 rk_dns_string_to_type(const char *name)
85 {
86 struct stot *p = stot;
87 for(p = stot; p->name; p++)
88 if(strcasecmp(name, p->name) == 0)
89 return p->type;
90 return -1;
91 }
92
93 ROKEN_LIB_FUNCTION const char * ROKEN_LIB_CALL
rk_dns_type_to_string(int type)94 rk_dns_type_to_string(int type)
95 {
96 struct stot *p = stot;
97 for(p = stot; p->name; p++)
98 if(type == p->type)
99 return p->name;
100 return NULL;
101 }
102
103 #if ((defined(HAVE_RES_SEARCH) || defined(HAVE_RES_NSEARCH)) && defined(HAVE_DN_EXPAND)) || defined(HAVE_WINDNS)
104
105 static void
dns_free_rr(struct rk_resource_record * rr)106 dns_free_rr(struct rk_resource_record *rr)
107 {
108 if(rr->domain)
109 free(rr->domain);
110 if(rr->u.data)
111 free(rr->u.data);
112 free(rr);
113 }
114
115 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
rk_dns_free_data(struct rk_dns_reply * r)116 rk_dns_free_data(struct rk_dns_reply *r)
117 {
118 struct rk_resource_record *rr;
119 if(r->q.domain)
120 free(r->q.domain);
121 for(rr = r->head; rr;){
122 struct rk_resource_record *tmp = rr;
123 rr = rr->next;
124 dns_free_rr(tmp);
125 }
126 free (r);
127 }
128
129 #ifndef HAVE_WINDNS
130
131 static int
parse_record(const unsigned char * data,const unsigned char * end_data,const unsigned char ** pp,struct rk_resource_record ** ret_rr)132 parse_record(const unsigned char *data, const unsigned char *end_data,
133 const unsigned char **pp, struct rk_resource_record **ret_rr)
134 {
135 struct rk_resource_record *rr;
136 int type, class, ttl;
137 unsigned size;
138 int status;
139 char host[MAXDNAME];
140 const unsigned char *p = *pp;
141
142 *ret_rr = NULL;
143
144 status = dn_expand(data, end_data, p, host, sizeof(host));
145 if(status < 0)
146 return -1;
147 if (p + status + 10 > end_data)
148 return -1;
149
150 p += status;
151 type = (p[0] << 8) | p[1];
152 p += 2;
153 class = (p[0] << 8) | p[1];
154 p += 2;
155 ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
156 p += 4;
157 size = (p[0] << 8) | p[1];
158 p += 2;
159
160 if (p + size > end_data)
161 return -1;
162
163 rr = calloc(1, sizeof(*rr));
164 if(rr == NULL)
165 return -1;
166 rr->domain = strdup(host);
167 if(rr->domain == NULL) {
168 dns_free_rr(rr);
169 return -1;
170 }
171 rr->type = type;
172 rr->class = class;
173 rr->ttl = ttl;
174 rr->size = size;
175 switch(type){
176 case rk_ns_t_ns:
177 case rk_ns_t_cname:
178 case rk_ns_t_ptr:
179 status = dn_expand(data, end_data, p, host, sizeof(host));
180 if(status < 0) {
181 dns_free_rr(rr);
182 return -1;
183 }
184 rr->u.txt = strdup(host);
185 if(rr->u.txt == NULL) {
186 dns_free_rr(rr);
187 return -1;
188 }
189 break;
190 case rk_ns_t_mx:
191 case rk_ns_t_afsdb:{
192 size_t hostlen;
193
194 status = dn_expand(data, end_data, p + 2, host, sizeof(host));
195 if(status < 0){
196 dns_free_rr(rr);
197 return -1;
198 }
199 if ((size_t)status + 2 > size) {
200 dns_free_rr(rr);
201 return -1;
202 }
203
204 hostlen = strlen(host);
205 rr->u.mx = (struct mx_record*)malloc(sizeof(struct mx_record) +
206 hostlen);
207 if(rr->u.mx == NULL) {
208 dns_free_rr(rr);
209 return -1;
210 }
211 rr->u.mx->preference = (p[0] << 8) | p[1];
212 strlcpy(rr->u.mx->domain, host, hostlen + 1);
213 break;
214 }
215 case rk_ns_t_srv:{
216 size_t hostlen;
217 status = dn_expand(data, end_data, p + 6, host, sizeof(host));
218 if(status < 0){
219 dns_free_rr(rr);
220 return -1;
221 }
222 if ((size_t)status + 6 > size) {
223 dns_free_rr(rr);
224 return -1;
225 }
226
227 hostlen = strlen(host);
228 rr->u.srv =
229 (struct srv_record*)malloc(sizeof(struct srv_record) +
230 hostlen);
231 if(rr->u.srv == NULL) {
232 dns_free_rr(rr);
233 return -1;
234 }
235 rr->u.srv->priority = (p[0] << 8) | p[1];
236 rr->u.srv->weight = (p[2] << 8) | p[3];
237 rr->u.srv->port = (p[4] << 8) | p[5];
238 strlcpy(rr->u.srv->target, host, hostlen + 1);
239 break;
240 }
241 case rk_ns_t_txt:{
242 if(size == 0 || size < (unsigned)(*p + 1)) {
243 dns_free_rr(rr);
244 return -1;
245 }
246 rr->u.txt = (char*)malloc(*p + 1);
247 if(rr->u.txt == NULL) {
248 dns_free_rr(rr);
249 return -1;
250 }
251 strncpy(rr->u.txt, (const char*)(p + 1), *p);
252 rr->u.txt[*p] = '\0';
253 break;
254 }
255 case rk_ns_t_key : {
256 size_t key_len;
257
258 if (size < 4) {
259 dns_free_rr(rr);
260 return -1;
261 }
262
263 key_len = size - 4;
264 rr->u.key = malloc (sizeof(*rr->u.key) + key_len - 1);
265 if (rr->u.key == NULL) {
266 dns_free_rr(rr);
267 return -1;
268 }
269
270 rr->u.key->flags = (p[0] << 8) | p[1];
271 rr->u.key->protocol = p[2];
272 rr->u.key->algorithm = p[3];
273 rr->u.key->key_len = key_len;
274 memcpy (rr->u.key->key_data, p + 4, key_len);
275 break;
276 }
277 case rk_ns_t_sig : {
278 size_t sig_len, hostlen;
279
280 if(size <= 18) {
281 dns_free_rr(rr);
282 return -1;
283 }
284 status = dn_expand (data, end_data, p + 18, host, sizeof(host));
285 if (status < 0) {
286 dns_free_rr(rr);
287 return -1;
288 }
289 if ((size_t)status + 18 > size) {
290 dns_free_rr(rr);
291 return -1;
292 }
293
294 /* the signer name is placed after the sig_data, to make it
295 easy to free this structure; the size calculation below
296 includes the zero-termination if the structure itself.
297 don't you just love C?
298 */
299 sig_len = size - 18 - status;
300 hostlen = strlen(host);
301 rr->u.sig = malloc(sizeof(*rr->u.sig)
302 + hostlen + sig_len);
303 if (rr->u.sig == NULL) {
304 dns_free_rr(rr);
305 return -1;
306 }
307 rr->u.sig->type = (p[0] << 8) | p[1];
308 rr->u.sig->algorithm = p[2];
309 rr->u.sig->labels = p[3];
310 rr->u.sig->orig_ttl = (p[4] << 24) | (p[5] << 16)
311 | (p[6] << 8) | p[7];
312 rr->u.sig->sig_expiration = (p[8] << 24) | (p[9] << 16)
313 | (p[10] << 8) | p[11];
314 rr->u.sig->sig_inception = (p[12] << 24) | (p[13] << 16)
315 | (p[14] << 8) | p[15];
316 rr->u.sig->key_tag = (p[16] << 8) | p[17];
317 rr->u.sig->sig_len = sig_len;
318 memcpy (rr->u.sig->sig_data, p + 18 + status, sig_len);
319 rr->u.sig->signer = &rr->u.sig->sig_data[sig_len];
320 strlcpy(rr->u.sig->signer, host, hostlen + 1);
321 break;
322 }
323
324 case rk_ns_t_cert : {
325 size_t cert_len;
326
327 if (size < 5) {
328 dns_free_rr(rr);
329 return -1;
330 }
331
332 cert_len = size - 5;
333 rr->u.cert = malloc (sizeof(*rr->u.cert) + cert_len - 1);
334 if (rr->u.cert == NULL) {
335 dns_free_rr(rr);
336 return -1;
337 }
338
339 rr->u.cert->type = (p[0] << 8) | p[1];
340 rr->u.cert->tag = (p[2] << 8) | p[3];
341 rr->u.cert->algorithm = p[4];
342 rr->u.cert->cert_len = cert_len;
343 memcpy (rr->u.cert->cert_data, p + 5, cert_len);
344 break;
345 }
346 case rk_ns_t_sshfp : {
347 size_t sshfp_len;
348
349 if (size < 2) {
350 dns_free_rr(rr);
351 return -1;
352 }
353
354 sshfp_len = size - 2;
355
356 rr->u.sshfp = malloc (sizeof(*rr->u.sshfp) + sshfp_len - 1);
357 if (rr->u.sshfp == NULL) {
358 dns_free_rr(rr);
359 return -1;
360 }
361
362 rr->u.sshfp->algorithm = p[0];
363 rr->u.sshfp->type = p[1];
364 rr->u.sshfp->sshfp_len = sshfp_len;
365 memcpy (rr->u.sshfp->sshfp_data, p + 2, sshfp_len);
366 break;
367 }
368 case rk_ns_t_ds: {
369 size_t digest_len;
370
371 if (size < 4) {
372 dns_free_rr(rr);
373 return -1;
374 }
375
376 digest_len = size - 4;
377
378 rr->u.ds = malloc (sizeof(*rr->u.ds) + digest_len - 1);
379 if (rr->u.ds == NULL) {
380 dns_free_rr(rr);
381 return -1;
382 }
383
384 rr->u.ds->key_tag = (p[0] << 8) | p[1];
385 rr->u.ds->algorithm = p[2];
386 rr->u.ds->digest_type = p[3];
387 rr->u.ds->digest_len = digest_len;
388 memcpy (rr->u.ds->digest_data, p + 4, digest_len);
389 break;
390 }
391 default:
392 rr->u.data = (unsigned char*)malloc(size);
393 if(size != 0 && rr->u.data == NULL) {
394 dns_free_rr(rr);
395 return -1;
396 }
397 if (size)
398 memcpy(rr->u.data, p, size);
399 }
400 *pp = p + size;
401 *ret_rr = rr;
402
403 return 0;
404 }
405
406 #ifndef TEST_RESOLVE
407 static
408 #endif
409 struct rk_dns_reply*
parse_reply(const unsigned char * data,size_t len)410 parse_reply(const unsigned char *data, size_t len)
411 {
412 const unsigned char *p;
413 int status;
414 size_t i;
415 char host[MAXDNAME];
416 const unsigned char *end_data = data + len;
417 struct rk_dns_reply *r;
418 struct rk_resource_record **rr;
419
420 r = calloc(1, sizeof(*r));
421 if (r == NULL)
422 return NULL;
423
424 p = data;
425
426 r->h.id = (p[0] << 8) | p[1];
427 r->h.flags = 0;
428 if (p[2] & 0x01)
429 r->h.flags |= rk_DNS_HEADER_RESPONSE_FLAG;
430 r->h.opcode = (p[2] >> 1) & 0xf;
431 if (p[2] & 0x20)
432 r->h.flags |= rk_DNS_HEADER_AUTHORITIVE_ANSWER;
433 if (p[2] & 0x40)
434 r->h.flags |= rk_DNS_HEADER_TRUNCATED_MESSAGE;
435 if (p[2] & 0x80)
436 r->h.flags |= rk_DNS_HEADER_RECURSION_DESIRED;
437 if (p[3] & 0x01)
438 r->h.flags |= rk_DNS_HEADER_RECURSION_AVAILABLE;
439 if (p[3] & 0x04)
440 r->h.flags |= rk_DNS_HEADER_AUTHORITIVE_ANSWER;
441 if (p[3] & 0x08)
442 r->h.flags |= rk_DNS_HEADER_CHECKING_DISABLED;
443 r->h.response_code = (p[3] >> 4) & 0xf;
444 r->h.qdcount = (p[4] << 8) | p[5];
445 r->h.ancount = (p[6] << 8) | p[7];
446 r->h.nscount = (p[8] << 8) | p[9];
447 r->h.arcount = (p[10] << 8) | p[11];
448
449 p += 12;
450
451 if(r->h.qdcount != 1) {
452 free(r);
453 return NULL;
454 }
455 status = dn_expand(data, end_data, p, host, sizeof(host));
456 if(status < 0){
457 rk_dns_free_data(r);
458 return NULL;
459 }
460 r->q.domain = strdup(host);
461 if(r->q.domain == NULL) {
462 rk_dns_free_data(r);
463 return NULL;
464 }
465 if (p + status + 4 > end_data) {
466 rk_dns_free_data(r);
467 return NULL;
468 }
469 p += status;
470 r->q.type = (p[0] << 8 | p[1]);
471 p += 2;
472 r->q.class = (p[0] << 8 | p[1]);
473 p += 2;
474
475 rr = &r->head;
476 for(i = 0; i < r->h.ancount; i++) {
477 if(parse_record(data, end_data, &p, rr) != 0) {
478 rk_dns_free_data(r);
479 return NULL;
480 }
481 rr = &(*rr)->next;
482 }
483 for(i = 0; i < r->h.nscount; i++) {
484 if(parse_record(data, end_data, &p, rr) != 0) {
485 rk_dns_free_data(r);
486 return NULL;
487 }
488 rr = &(*rr)->next;
489 }
490 for(i = 0; i < r->h.arcount; i++) {
491 if(parse_record(data, end_data, &p, rr) != 0) {
492 rk_dns_free_data(r);
493 return NULL;
494 }
495 rr = &(*rr)->next;
496 }
497 *rr = NULL;
498 return r;
499 }
500
501 #ifdef HAVE_RES_NSEARCH
502 #ifdef HAVE_RES_NDESTROY
503 #define rk_res_free(x) res_ndestroy(x)
504 #else
505 #define rk_res_free(x) res_nclose(x)
506 #endif
507 #endif
508
509 #if defined(HAVE_DNS_SEARCH)
510 #define resolve_search(h,n,c,t,r,l) \
511 ((int)dns_search(h,n,c,t,r,l,(struct sockaddr *)&from,&fromsize))
512 #define resolve_free_handle(h) dns_free(h)
513 #elif defined(HAVE_RES_NSEARCH)
514 #define resolve_search(h,n,c,t,r,l) res_nsearch(h,n,c,t,r,l)
515 #define resolve_free_handle(h) rk_res_free(h);
516 #else
517 #define resolve_search(h,n,c,t,r,l) res_search(n,c,t,r,l)
518 #define handle 0
519 #define resolve_free_handle(h)
520 #endif
521
522
523 static struct rk_dns_reply *
dns_lookup_int(const char * domain,int rr_class,int rr_type)524 dns_lookup_int(const char *domain, int rr_class, int rr_type)
525 {
526 struct rk_dns_reply *r;
527 void *reply = NULL;
528 int size, len;
529 #if defined(HAVE_DNS_SEARCH)
530 struct sockaddr_storage from;
531 uint32_t fromsize = sizeof(from);
532 dns_handle_t handle;
533
534 handle = dns_open(NULL);
535 if (handle == NULL)
536 return NULL;
537 #elif defined(HAVE_RES_NSEARCH)
538 struct __res_state state;
539 struct __res_state *handle = &state;
540
541 memset(&state, 0, sizeof(state));
542 if(res_ninit(handle))
543 return NULL; /* is this the best we can do? */
544 #endif
545
546 len = 1500;
547 while(1) {
548 if (reply) {
549 free(reply);
550 reply = NULL;
551 }
552 if (_resolve_debug) {
553 #if defined(HAVE_DNS_SEARCH)
554 dns_set_debug(handle, 1);
555 #elif defined(HAVE_RES_NSEARCH)
556 state.options |= RES_DEBUG;
557 #endif
558 fprintf(stderr, "dns_lookup(%s, %d, %s), buffer size %d\n", domain,
559 rr_class, rk_dns_type_to_string(rr_type), len);
560 }
561 reply = malloc(len);
562 if (reply == NULL) {
563 resolve_free_handle(handle);
564 return NULL;
565 }
566
567 size = resolve_search(handle, domain, rr_class, rr_type, reply, len);
568
569 if (_resolve_debug) {
570 fprintf(stderr, "dns_lookup(%s, %d, %s) --> %d\n",
571 domain, rr_class, rk_dns_type_to_string(rr_type), size);
572 }
573 if (size > len) {
574 /* resolver thinks it know better, go for it */
575 len = size;
576 } else if (size > 0) {
577 /* got a good reply */
578 break;
579 } else if (size <= 0 && len < rk_DNS_MAX_PACKET_SIZE) {
580 len *= 2;
581 if (len > rk_DNS_MAX_PACKET_SIZE)
582 len = rk_DNS_MAX_PACKET_SIZE;
583 } else {
584 /* the end, leave */
585 resolve_free_handle(handle);
586 free(reply);
587 return NULL;
588 }
589 }
590
591 len = min(len, size);
592 r = parse_reply(reply, len);
593 free(reply);
594
595 resolve_free_handle(handle);
596
597 return r;
598 }
599
600 ROKEN_LIB_FUNCTION struct rk_dns_reply * ROKEN_LIB_CALL
rk_dns_lookup(const char * domain,const char * type_name)601 rk_dns_lookup(const char *domain, const char *type_name)
602 {
603 int type;
604
605 type = rk_dns_string_to_type(type_name);
606 if(type == -1) {
607 if(_resolve_debug)
608 fprintf(stderr, "dns_lookup: unknown resource type: `%s'\n",
609 type_name);
610 return NULL;
611 }
612 return dns_lookup_int(domain, rk_ns_c_in, type);
613 }
614
615 #endif /* !HAVE_WINDNS */
616
617 static int
compare_srv(const void * a,const void * b)618 compare_srv(const void *a, const void *b)
619 {
620 const struct rk_resource_record *const* aa = a, *const* bb = b;
621
622 if((*aa)->u.srv->priority == (*bb)->u.srv->priority)
623 return ((*aa)->u.srv->weight - (*bb)->u.srv->weight);
624 return ((*aa)->u.srv->priority - (*bb)->u.srv->priority);
625 }
626
627 /* try to rearrange the srv-records by the algorithm in RFC2782 */
628 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
rk_dns_srv_order(struct rk_dns_reply * r)629 rk_dns_srv_order(struct rk_dns_reply *r)
630 {
631 struct rk_resource_record **srvs, **ss, **headp;
632 struct rk_resource_record *rr;
633 int num_srv = 0;
634
635 rk_random_init();
636
637 for(rr = r->head; rr; rr = rr->next)
638 if(rr->type == rk_ns_t_srv)
639 num_srv++;
640
641 if(num_srv == 0)
642 return;
643
644 srvs = malloc(num_srv * sizeof(*srvs));
645 if(srvs == NULL)
646 return; /* XXX not much to do here */
647
648 /* unlink all srv-records from the linked list and put them in
649 a vector */
650 for(ss = srvs, headp = &r->head; *headp; )
651 if((*headp)->type == rk_ns_t_srv) {
652 *ss = *headp;
653 *headp = (*headp)->next;
654 (*ss)->next = NULL;
655 ss++;
656 } else
657 headp = &(*headp)->next;
658
659 /* sort them by priority and weight */
660 qsort(srvs, num_srv, sizeof(*srvs), compare_srv);
661
662 headp = &r->head;
663
664 for(ss = srvs; ss < srvs + num_srv; ) {
665 int sum, rnd, count;
666 struct rk_resource_record **ee, **tt;
667 /* find the last record with the same priority and count the
668 sum of all weights */
669 for(sum = 0, tt = ss; tt < srvs + num_srv; tt++) {
670 assert(*tt != NULL);
671 if((*tt)->u.srv->priority != (*ss)->u.srv->priority)
672 break;
673 sum += (*tt)->u.srv->weight;
674 }
675 ee = tt;
676 /* ss is now the first record of this priority and ee is the
677 first of the next */
678 while(ss < ee) {
679 rnd = rk_random() % (sum + 1);
680 for(count = 0, tt = ss; ; tt++) {
681 if(*tt == NULL)
682 continue;
683 count += (*tt)->u.srv->weight;
684 if(count >= rnd)
685 break;
686 }
687
688 assert(tt < ee);
689
690 /* insert the selected record at the tail (of the head) of
691 the list */
692 (*tt)->next = *headp;
693 *headp = *tt;
694 headp = &(*tt)->next;
695 sum -= (*tt)->u.srv->weight;
696 *tt = NULL;
697 while(ss < ee && *ss == NULL)
698 ss++;
699 }
700 }
701
702 free(srvs);
703 return;
704 }
705
706 #ifdef HAVE_WINDNS
707
708 #include <WinDNS.h>
709
710 static struct rk_resource_record *
parse_dns_record(PDNS_RECORD pRec)711 parse_dns_record(PDNS_RECORD pRec)
712 {
713 struct rk_resource_record * rr;
714
715 if (pRec == NULL)
716 return NULL;
717
718 rr = calloc(1, sizeof(*rr));
719
720 rr->domain = strdup(pRec->pName);
721 rr->type = pRec->wType;
722 rr->class = 0;
723 rr->ttl = pRec->dwTtl;
724 rr->size = 0;
725
726 switch (rr->type) {
727 case rk_ns_t_ns:
728 case rk_ns_t_cname:
729 case rk_ns_t_ptr:
730 rr->u.txt = strdup(pRec->Data.NS.pNameHost);
731 if(rr->u.txt == NULL) {
732 dns_free_rr(rr);
733 return NULL;
734 }
735 break;
736
737 case rk_ns_t_mx:
738 case rk_ns_t_afsdb:{
739 size_t hostlen = strnlen(pRec->Data.MX.pNameExchange, DNS_MAX_NAME_LENGTH);
740
741 rr->u.mx = (struct mx_record *)malloc(sizeof(struct mx_record) +
742 hostlen);
743 if (rr->u.mx == NULL) {
744 dns_free_rr(rr);
745 return NULL;
746 }
747
748 strcpy_s(rr->u.mx->domain, hostlen + 1, pRec->Data.MX.pNameExchange);
749 rr->u.mx->preference = pRec->Data.MX.wPreference;
750 break;
751 }
752
753 case rk_ns_t_srv:{
754 size_t hostlen = strnlen(pRec->Data.SRV.pNameTarget, DNS_MAX_NAME_LENGTH);
755
756 rr->u.srv =
757 (struct srv_record*)malloc(sizeof(struct srv_record) +
758 hostlen);
759 if(rr->u.srv == NULL) {
760 dns_free_rr(rr);
761 return NULL;
762 }
763
764 rr->u.srv->priority = pRec->Data.SRV.wPriority;
765 rr->u.srv->weight = pRec->Data.SRV.wWeight;
766 rr->u.srv->port = pRec->Data.SRV.wPort;
767 strcpy_s(rr->u.srv->target, hostlen + 1, pRec->Data.SRV.pNameTarget);
768
769 break;
770 }
771
772 case rk_ns_t_txt:{
773 size_t len;
774
775 if (pRec->Data.TXT.dwStringCount == 0) {
776 rr->u.txt = strdup("");
777 break;
778 }
779
780 len = strnlen(pRec->Data.TXT.pStringArray[0], DNS_MAX_TEXT_STRING_LENGTH);
781
782 rr->u.txt = (char *)malloc(len + 1);
783 strcpy_s(rr->u.txt, len + 1, pRec->Data.TXT.pStringArray[0]);
784
785 break;
786 }
787
788 case rk_ns_t_key : {
789 size_t key_len;
790
791 if (pRec->wDataLength < 4) {
792 dns_free_rr(rr);
793 return NULL;
794 }
795
796 key_len = pRec->wDataLength - 4;
797 rr->u.key = malloc (sizeof(*rr->u.key) + key_len - 1);
798 if (rr->u.key == NULL) {
799 dns_free_rr(rr);
800 return NULL;
801 }
802
803 rr->u.key->flags = pRec->Data.KEY.wFlags;
804 rr->u.key->protocol = pRec->Data.KEY.chProtocol;
805 rr->u.key->algorithm = pRec->Data.KEY.chAlgorithm;
806 rr->u.key->key_len = key_len;
807 memcpy_s (rr->u.key->key_data, key_len,
808 pRec->Data.KEY.Key, key_len);
809 break;
810 }
811
812 case rk_ns_t_sig : {
813 size_t sig_len, hostlen;
814
815 if(pRec->wDataLength <= 18) {
816 dns_free_rr(rr);
817 return NULL;
818 }
819
820 sig_len = pRec->wDataLength;
821
822 hostlen = strnlen(pRec->Data.SIG.pNameSigner, DNS_MAX_NAME_LENGTH);
823
824 rr->u.sig = malloc(sizeof(*rr->u.sig)
825 + hostlen + sig_len);
826 if (rr->u.sig == NULL) {
827 dns_free_rr(rr);
828 return NULL;
829 }
830 rr->u.sig->type = pRec->Data.SIG.wTypeCovered;
831 rr->u.sig->algorithm = pRec->Data.SIG.chAlgorithm;
832 rr->u.sig->labels = pRec->Data.SIG.chLabelCount;
833 rr->u.sig->orig_ttl = pRec->Data.SIG.dwOriginalTtl;
834 rr->u.sig->sig_expiration = pRec->Data.SIG.dwExpiration;
835 rr->u.sig->sig_inception = pRec->Data.SIG.dwTimeSigned;
836 rr->u.sig->key_tag = pRec->Data.SIG.wKeyTag;
837 rr->u.sig->sig_len = sig_len;
838 memcpy_s (rr->u.sig->sig_data, sig_len,
839 pRec->Data.SIG.Signature, sig_len);
840 rr->u.sig->signer = &rr->u.sig->sig_data[sig_len];
841 strcpy_s(rr->u.sig->signer, hostlen + 1, pRec->Data.SIG.pNameSigner);
842 break;
843 }
844
845 #ifdef DNS_TYPE_DS
846 case rk_ns_t_ds: {
847 rr->u.ds = malloc (sizeof(*rr->u.ds) + pRec->Data.DS.wDigestLength - 1);
848 if (rr->u.ds == NULL) {
849 dns_free_rr(rr);
850 return NULL;
851 }
852
853 rr->u.ds->key_tag = pRec->Data.DS.wKeyTag;
854 rr->u.ds->algorithm = pRec->Data.DS.chAlgorithm;
855 rr->u.ds->digest_type = pRec->Data.DS.chDigestType;
856 rr->u.ds->digest_len = pRec->Data.DS.wDigestLength;
857 memcpy_s (rr->u.ds->digest_data, pRec->Data.DS.wDigestLength,
858 pRec->Data.DS.Digest, pRec->Data.DS.wDigestLength);
859 break;
860 }
861 #endif
862
863 default:
864 dns_free_rr(rr);
865 return NULL;
866 }
867
868 rr->next = parse_dns_record(pRec->pNext);
869 return rr;
870 }
871
872 ROKEN_LIB_FUNCTION struct rk_dns_reply * ROKEN_LIB_CALL
rk_dns_lookup(const char * domain,const char * type_name)873 rk_dns_lookup(const char *domain, const char *type_name)
874 {
875 DNS_STATUS status;
876 int type;
877 PDNS_RECORD pRec = NULL;
878 struct rk_dns_reply * r = NULL;
879
880 __try {
881
882 type = rk_dns_string_to_type(type_name);
883 if(type == -1) {
884 if(_resolve_debug)
885 fprintf(stderr, "dns_lookup: unknown resource type: `%s'\n",
886 type_name);
887 return NULL;
888 }
889
890 status = DnsQuery_UTF8(domain, type, DNS_QUERY_STANDARD, NULL,
891 &pRec, NULL);
892 if (status != ERROR_SUCCESS)
893 return NULL;
894
895 r = calloc(1, sizeof(*r));
896 r->q.domain = strdup(domain);
897 r->q.type = type;
898 r->q.class = 0;
899
900 r->head = parse_dns_record(pRec);
901
902 if (r->head == NULL) {
903 rk_dns_free_data(r);
904 return NULL;
905 } else {
906 return r;
907 }
908
909 } __finally {
910
911 if (pRec)
912 DnsRecordListFree(pRec, DnsFreeRecordList);
913
914 }
915 }
916 #endif /* HAVE_WINDNS */
917
918 #else /* NOT defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND) */
919
920 ROKEN_LIB_FUNCTION struct rk_dns_reply * ROKEN_LIB_CALL
rk_dns_lookup(const char * domain,const char * type_name)921 rk_dns_lookup(const char *domain, const char *type_name)
922 {
923 return NULL;
924 }
925
926 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
rk_dns_free_data(struct rk_dns_reply * r)927 rk_dns_free_data(struct rk_dns_reply *r)
928 {
929 }
930
931 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
rk_dns_srv_order(struct rk_dns_reply * r)932 rk_dns_srv_order(struct rk_dns_reply *r)
933 {
934 }
935
936 #endif
937