2 * Copyright (c) 1995 - 2006 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
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 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 #ifdef HAVE_ARPA_NAMESER_H
39 #include <arpa/nameser.h>
53 #ifdef _AIX /* AIX have broken res_nsearch() in 5.1 (5.0 also ?) */
54 #undef HAVE_RES_NSEARCH
57 #define DECL(X) {#X, rk_ns_t_##X}
81 int _resolve_debug = 0;
83 int ROKEN_LIB_FUNCTION
84 rk_dns_string_to_type(const char *name)
86 struct stot *p = stot;
87 for(p = stot; p->name; p++)
88 if(strcasecmp(name, p->name) == 0)
93 const char * ROKEN_LIB_FUNCTION
94 rk_dns_type_to_string(int type)
96 struct stot *p = stot;
97 for(p = stot; p->name; p++)
103 #if (defined(HAVE_RES_SEARCH) || defined(HAVE_RES_NSEARCH)) && defined(HAVE_DN_EXPAND)
106 dns_free_rr(struct rk_resource_record *rr)
115 void ROKEN_LIB_FUNCTION
116 rk_dns_free_data(struct rk_dns_reply *r)
118 struct rk_resource_record *rr;
121 for(rr = r->head; rr;){
122 struct rk_resource_record *tmp = rr;
130 parse_record(const unsigned char *data, const unsigned char *end_data,
131 const unsigned char **pp, struct rk_resource_record **ret_rr)
133 struct rk_resource_record *rr;
134 int type, class, ttl;
138 const unsigned char *p = *pp;
142 status = dn_expand(data, end_data, p, host, sizeof(host));
145 if (p + status + 10 > end_data)
149 type = (p[0] << 8) | p[1];
151 class = (p[0] << 8) | p[1];
153 ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
155 size = (p[0] << 8) | p[1];
158 if (p + size > end_data)
161 rr = calloc(1, sizeof(*rr));
164 rr->domain = strdup(host);
165 if(rr->domain == NULL) {
177 status = dn_expand(data, end_data, p, host, sizeof(host));
182 rr->u.txt = strdup(host);
183 if(rr->u.txt == NULL) {
192 status = dn_expand(data, end_data, p + 2, host, sizeof(host));
197 if (status + 2 > size) {
202 hostlen = strlen(host);
203 rr->u.mx = (struct mx_record*)malloc(sizeof(struct mx_record) +
205 if(rr->u.mx == NULL) {
209 rr->u.mx->preference = (p[0] << 8) | p[1];
210 strlcpy(rr->u.mx->domain, host, hostlen + 1);
215 status = dn_expand(data, end_data, p + 6, host, sizeof(host));
220 if (status + 6 > size) {
225 hostlen = strlen(host);
227 (struct srv_record*)malloc(sizeof(struct srv_record) +
229 if(rr->u.srv == NULL) {
233 rr->u.srv->priority = (p[0] << 8) | p[1];
234 rr->u.srv->weight = (p[2] << 8) | p[3];
235 rr->u.srv->port = (p[4] << 8) | p[5];
236 strlcpy(rr->u.srv->target, host, hostlen + 1);
240 if(size == 0 || size < *p + 1) {
244 rr->u.txt = (char*)malloc(*p + 1);
245 if(rr->u.txt == NULL) {
249 strncpy(rr->u.txt, (const char*)(p + 1), *p);
250 rr->u.txt[*p] = '\0';
262 rr->u.key = malloc (sizeof(*rr->u.key) + key_len - 1);
263 if (rr->u.key == NULL) {
268 rr->u.key->flags = (p[0] << 8) | p[1];
269 rr->u.key->protocol = p[2];
270 rr->u.key->algorithm = p[3];
271 rr->u.key->key_len = key_len;
272 memcpy (rr->u.key->key_data, p + 4, key_len);
276 size_t sig_len, hostlen;
282 status = dn_expand (data, end_data, p + 18, host, sizeof(host));
287 if (status + 18 > size) {
292 /* the signer name is placed after the sig_data, to make it
293 easy to free this structure; the size calculation below
294 includes the zero-termination if the structure itself.
295 don't you just love C?
297 sig_len = size - 18 - status;
298 hostlen = strlen(host);
299 rr->u.sig = malloc(sizeof(*rr->u.sig)
300 + hostlen + sig_len);
301 if (rr->u.sig == NULL) {
305 rr->u.sig->type = (p[0] << 8) | p[1];
306 rr->u.sig->algorithm = p[2];
307 rr->u.sig->labels = p[3];
308 rr->u.sig->orig_ttl = (p[4] << 24) | (p[5] << 16)
309 | (p[6] << 8) | p[7];
310 rr->u.sig->sig_expiration = (p[8] << 24) | (p[9] << 16)
311 | (p[10] << 8) | p[11];
312 rr->u.sig->sig_inception = (p[12] << 24) | (p[13] << 16)
313 | (p[14] << 8) | p[15];
314 rr->u.sig->key_tag = (p[16] << 8) | p[17];
315 rr->u.sig->sig_len = sig_len;
316 memcpy (rr->u.sig->sig_data, p + 18 + status, sig_len);
317 rr->u.sig->signer = &rr->u.sig->sig_data[sig_len];
318 strlcpy(rr->u.sig->signer, host, hostlen + 1);
322 case rk_ns_t_cert : {
331 rr->u.cert = malloc (sizeof(*rr->u.cert) + cert_len - 1);
332 if (rr->u.cert == NULL) {
337 rr->u.cert->type = (p[0] << 8) | p[1];
338 rr->u.cert->tag = (p[2] << 8) | p[3];
339 rr->u.cert->algorithm = p[4];
340 rr->u.cert->cert_len = cert_len;
341 memcpy (rr->u.cert->cert_data, p + 5, cert_len);
344 case rk_ns_t_sshfp : {
352 sshfp_len = size - 2;
354 rr->u.sshfp = malloc (sizeof(*rr->u.sshfp) + sshfp_len - 1);
355 if (rr->u.sshfp == NULL) {
360 rr->u.sshfp->algorithm = p[0];
361 rr->u.sshfp->type = p[1];
362 rr->u.sshfp->sshfp_len = sshfp_len;
363 memcpy (rr->u.sshfp->sshfp_data, p + 2, sshfp_len);
374 digest_len = size - 4;
376 rr->u.ds = malloc (sizeof(*rr->u.ds) + digest_len - 1);
377 if (rr->u.ds == NULL) {
382 rr->u.ds->key_tag = (p[0] << 8) | p[1];
383 rr->u.ds->algorithm = p[2];
384 rr->u.ds->digest_type = p[3];
385 rr->u.ds->digest_len = digest_len;
386 memcpy (rr->u.ds->digest_data, p + 4, digest_len);
390 rr->u.data = (unsigned char*)malloc(size);
391 if(size != 0 && rr->u.data == NULL) {
396 memcpy(rr->u.data, p, size);
408 parse_reply(const unsigned char *data, size_t len)
410 const unsigned char *p;
414 const unsigned char *end_data = data + len;
415 struct rk_dns_reply *r;
416 struct rk_resource_record **rr;
418 r = calloc(1, sizeof(*r));
424 r->h.id = (p[0] << 8) | p[1];
427 r->h.flags |= rk_DNS_HEADER_RESPONSE_FLAG;
428 r->h.opcode = (p[2] >> 1) & 0xf;
430 r->h.flags |= rk_DNS_HEADER_AUTHORITIVE_ANSWER;
432 r->h.flags |= rk_DNS_HEADER_TRUNCATED_MESSAGE;
434 r->h.flags |= rk_DNS_HEADER_RECURSION_DESIRED;
436 r->h.flags |= rk_DNS_HEADER_RECURSION_AVAILABLE;
438 r->h.flags |= rk_DNS_HEADER_AUTHORITIVE_ANSWER;
440 r->h.flags |= rk_DNS_HEADER_CHECKING_DISABLED;
441 r->h.response_code = (p[3] >> 4) & 0xf;
442 r->h.qdcount = (p[4] << 8) | p[5];
443 r->h.ancount = (p[6] << 8) | p[7];
444 r->h.nscount = (p[8] << 8) | p[9];
445 r->h.arcount = (p[10] << 8) | p[11];
449 if(r->h.qdcount != 1) {
453 status = dn_expand(data, end_data, p, host, sizeof(host));
458 r->q.domain = strdup(host);
459 if(r->q.domain == NULL) {
463 if (p + status + 4 > end_data) {
468 r->q.type = (p[0] << 8 | p[1]);
470 r->q.class = (p[0] << 8 | p[1]);
474 for(i = 0; i < r->h.ancount; i++) {
475 if(parse_record(data, end_data, &p, rr) != 0) {
481 for(i = 0; i < r->h.nscount; i++) {
482 if(parse_record(data, end_data, &p, rr) != 0) {
488 for(i = 0; i < r->h.arcount; i++) {
489 if(parse_record(data, end_data, &p, rr) != 0) {
499 #ifdef HAVE_RES_NSEARCH
500 #ifdef HAVE_RES_NDESTROY
501 #define rk_res_free(x) res_ndestroy(x)
503 #define rk_res_free(x) res_nclose(x)
507 #if defined(HAVE_DNS_SEARCH)
508 #define resolve_search(h,n,c,t,r,l) \
509 ((int)dns_search(h,n,c,t,r,l,(struct sockaddr *)&from,&fromsize))
510 #define resolve_free_handle(h) dns_free(h)
511 #elif defined(HAVE_RES_NSEARCH)
512 #define resolve_search(h,n,c,t,r,l) dns_nsearch(h,n,c,t,r,l)
513 #define resolve_free_handle(h) rk_res_free(h);
515 #define resolve_search(h,n,c,t,r,l) dns_search(n,c,t,r,l)
517 #define resolve_free_handle(h)
521 static struct rk_dns_reply *
522 dns_lookup_int(const char *domain, int rr_class, int rr_type)
524 struct rk_dns_reply *r;
528 #if defined(HAVE_DNS_SEARCH)
529 struct sockaddr_storage from;
530 uint32_t fromsize = sizeof(from);
533 handle = dns_open(NULL);
536 #elif defined(HAVE_RES_NSEARCH)
537 struct __res_state state;
538 struct __res_state *handle = &state;
540 memset(&state, 0, sizeof(state));
541 if(res_ninit(handle))
542 return NULL; /* is this the best we can do? */
554 if (_resolve_debug) {
555 #if defined(HAVE_DNS_SEARCH)
556 dns_set_debug(handle, 1);
557 #elif defined(HAVE_RES_NSEARCH)
558 state.options |= RES_DEBUG;
560 fprintf(stderr, "dns_lookup(%s, %d, %s), buffer size %d\n", domain,
561 rr_class, rk_dns_type_to_string(rr_type), size);
563 reply = malloc(size);
565 resolve_free_handle(handle);
569 len = resolve_search(handle, domain, rr_class, rr_type, reply, size);
571 if (_resolve_debug) {
572 fprintf(stderr, "dns_lookup(%s, %d, %s) --> %d\n",
573 domain, rr_class, rk_dns_type_to_string(rr_type), len);
576 resolve_free_handle(handle);
580 } while (size < len && len < rk_DNS_MAX_PACKET_SIZE);
581 resolve_free_handle(handle);
583 len = min(len, size);
584 r = parse_reply(reply, len);
589 struct rk_dns_reply * ROKEN_LIB_FUNCTION
590 rk_dns_lookup(const char *domain, const char *type_name)
594 type = rk_dns_string_to_type(type_name);
597 fprintf(stderr, "dns_lookup: unknown resource type: `%s'\n",
601 return dns_lookup_int(domain, rk_ns_c_in, type);
605 compare_srv(const void *a, const void *b)
607 const struct rk_resource_record *const* aa = a, *const* bb = b;
609 if((*aa)->u.srv->priority == (*bb)->u.srv->priority)
610 return ((*aa)->u.srv->weight - (*bb)->u.srv->weight);
611 return ((*aa)->u.srv->priority - (*bb)->u.srv->priority);
615 #define random() rand()
618 /* try to rearrange the srv-records by the algorithm in RFC2782 */
619 void ROKEN_LIB_FUNCTION
620 rk_dns_srv_order(struct rk_dns_reply *r)
622 struct rk_resource_record **srvs, **ss, **headp;
623 struct rk_resource_record *rr;
626 #if defined(HAVE_INITSTATE) && defined(HAVE_SETSTATE)
627 int state[256 / sizeof(int)];
631 for(rr = r->head; rr; rr = rr->next)
632 if(rr->type == rk_ns_t_srv)
638 srvs = malloc(num_srv * sizeof(*srvs));
640 return; /* XXX not much to do here */
642 /* unlink all srv-records from the linked list and put them in
644 for(ss = srvs, headp = &r->head; *headp; )
645 if((*headp)->type == rk_ns_t_srv) {
647 *headp = (*headp)->next;
651 headp = &(*headp)->next;
653 /* sort them by priority and weight */
654 qsort(srvs, num_srv, sizeof(*srvs), compare_srv);
656 #if defined(HAVE_INITSTATE) && defined(HAVE_SETSTATE)
657 oldstate = initstate(time(NULL), (char*)state, sizeof(state));
662 for(ss = srvs; ss < srvs + num_srv; ) {
664 struct rk_resource_record **ee, **tt;
665 /* find the last record with the same priority and count the
666 sum of all weights */
667 for(sum = 0, tt = ss; tt < srvs + num_srv; tt++) {
669 if((*tt)->u.srv->priority != (*ss)->u.srv->priority)
671 sum += (*tt)->u.srv->weight;
674 /* ss is now the first record of this priority and ee is the
677 rnd = random() % (sum + 1);
678 for(count = 0, tt = ss; ; tt++) {
681 count += (*tt)->u.srv->weight;
688 /* insert the selected record at the tail (of the head) of
690 (*tt)->next = *headp;
692 headp = &(*tt)->next;
693 sum -= (*tt)->u.srv->weight;
695 while(ss < ee && *ss == NULL)
700 #if defined(HAVE_INITSTATE) && defined(HAVE_SETSTATE)
707 #else /* NOT defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND) */
709 struct rk_dns_reply * ROKEN_LIB_FUNCTION
710 rk_dns_lookup(const char *domain, const char *type_name)
715 void ROKEN_LIB_FUNCTION
716 rk_dns_free_data(struct rk_dns_reply *r)
720 void ROKEN_LIB_FUNCTION
721 rk_dns_srv_order(struct rk_dns_reply *r)