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BIND: update vendor tree to 9.5.2-P2
[dragonfly.git] / contrib / bind / lib / bind / resolv / res_findzonecut.c
blobea778dbb29a906cad3771c354b79fd1f74b259e5
1 #if !defined(lint) && !defined(SABER)
2 static const char rcsid[] = "$Id: res_findzonecut.c,v 1.10 2005/10/11 00:10:16 marka Exp $";
3 #endif /* not lint */
4
5 /*
6 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
7 * Copyright (c) 1999 by Internet Software Consortium.
8 *
9 * Permission to use, copy, modify, and distribute this software for any
10 * purpose with or without fee is hereby granted, provided that the above
11 * copyright notice and this permission notice appear in all copies.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
19 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 */
21
22 /* Import. */
23
24 #include "port_before.h"
25
26 #include <sys/param.h>
27 #include <sys/socket.h>
28 #include <sys/time.h>
29
30 #include <netinet/in.h>
31 #include <arpa/inet.h>
32 #include <arpa/nameser.h>
33
34 #include <errno.h>
35 #include <limits.h>
36 #include <netdb.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41
42 #include "isc/list.h"
43
44 #include "port_after.h"
45
46 #include <resolv.h>
47
48 /* Data structures. */
49
50 typedef struct rr_a {
51 LINK(struct rr_a) link;
52 union res_sockaddr_union addr;
53 } rr_a;
54 typedef LIST(rr_a) rrset_a;
55
56 typedef struct rr_ns {
57 LINK(struct rr_ns) link;
58 const char * name;
59 unsigned int flags;
60 rrset_a addrs;
61 } rr_ns;
62 typedef LIST(rr_ns) rrset_ns;
63
64 #define RR_NS_HAVE_V4 0x01
65 #define RR_NS_HAVE_V6 0x02
66
67 /* Forward. */
68
69 static int satisfy(res_state, const char *, rrset_ns *,
70 union res_sockaddr_union *, int);
71 static int add_addrs(res_state, rr_ns *,
72 union res_sockaddr_union *, int);
73 static int get_soa(res_state, const char *, ns_class, int,
74 char *, size_t, char *, size_t,
75 rrset_ns *);
76 static int get_ns(res_state, const char *, ns_class, int, rrset_ns *);
77 static int get_glue(res_state, ns_class, int, rrset_ns *);
78 static int save_ns(res_state, ns_msg *, ns_sect,
79 const char *, ns_class, int, rrset_ns *);
80 static int save_a(res_state, ns_msg *, ns_sect,
81 const char *, ns_class, int, rr_ns *);
82 static void free_nsrrset(rrset_ns *);
83 static void free_nsrr(rrset_ns *, rr_ns *);
84 static rr_ns * find_ns(rrset_ns *, const char *);
85 static int do_query(res_state, const char *, ns_class, ns_type,
86 u_char *, ns_msg *);
87 static void res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
88
89 /* Macros. */
90
91 #define DPRINTF(x) do {\
92 int save_errno = errno; \
93 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
94 errno = save_errno; \
95 } while (0)
96
97 /* Public. */
98
99 /*%
100 * find enclosing zone for a <dname,class>, and some server addresses
101 *
102 * parameters:
103 *\li res - resolver context to work within (is modified)
104 *\li dname - domain name whose enclosing zone is desired
105 *\li class - class of dname (and its enclosing zone)
106 *\li zname - found zone name
107 *\li zsize - allocated size of zname
108 *\li addrs - found server addresses
109 *\li naddrs - max number of addrs
110 *
111 * return values:
112 *\li < 0 - an error occurred (check errno)
113 *\li = 0 - zname is now valid, but addrs[] wasn't changed
114 *\li > 0 - zname is now valid, and return value is number of addrs[] found
115 *
116 * notes:
117 *\li this function calls res_nsend() which means it depends on correctly
118 * functioning recursive nameservers (usually defined in /etc/resolv.conf
119 * or its local equivilent).
120 *
121 *\li we start by asking for an SOA<dname,class>. if we get one as an
122 * answer, that just means <dname,class> is a zone top, which is fine.
123 * more than likely we'll be told to go pound sand, in the form of a
124 * negative answer.
125 *
126 *\li note that we are not prepared to deal with referrals since that would
127 * only come from authority servers and our correctly functioning local
128 * recursive server would have followed the referral and got us something
129 * more definite.
130 *
131 *\li if the authority section contains an SOA, this SOA should also be the
132 * closest enclosing zone, since any intermediary zone cuts would've been
133 * returned as referrals and dealt with by our correctly functioning local
134 * recursive name server. but an SOA in the authority section should NOT
135 * match our dname (since that would have been returned in the answer
136 * section). an authority section SOA has to be "above" our dname.
137 *
138 *\li however, since authority section SOA's were once optional, it's
139 * possible that we'll have to go hunting for the enclosing SOA by
140 * ripping labels off the front of our dname -- this is known as "doing
141 * it the hard way."
142 *
143 *\li ultimately we want some server addresses, which are ideally the ones
144 * pertaining to the SOA.MNAME, but only if there is a matching NS RR.
145 * so the second phase (after we find an SOA) is to go looking for the
146 * NS RRset for that SOA's zone.
147 *
148 *\li no answer section processed by this code is allowed to contain CNAME
149 * or DNAME RR's. for the SOA query this means we strip a label and
150 * keep going. for the NS and A queries this means we just give up.
151 */
152
153 #ifndef _LIBC
154 int
155 res_findzonecut(res_state statp, const char *dname, ns_class class, int opts,
156 char *zname, size_t zsize, struct in_addr *addrs, int naddrs)
157 {
158 int result, i;
159 union res_sockaddr_union *u;
160
161
162 opts |= RES_IPV4ONLY;
163 opts &= ~RES_IPV6ONLY;
164
165 u = calloc(naddrs, sizeof(*u));
166 if (u == NULL)
167 return(-1);
168
169 result = res_findzonecut2(statp, dname, class, opts, zname, zsize,
170 u, naddrs);
171
172 for (i = 0; i < result; i++) {
173 addrs[i] = u[i].sin.sin_addr;
174 }
175 free(u);
176 return (result);
177 }
178 #endif
179 int
180 res_findzonecut2(res_state statp, const char *dname, ns_class class, int opts,
181 char *zname, size_t zsize, union res_sockaddr_union *addrs,
182 int naddrs)
183 {
184 char mname[NS_MAXDNAME];
185 u_long save_pfcode;
186 rrset_ns nsrrs;
187 int n;
188
189 DPRINTF(("START dname='%s' class=%s, zsize=%ld, naddrs=%d",
190 dname, p_class(class), (long)zsize, naddrs));
191 save_pfcode = statp->pfcode;
192 statp->pfcode |= RES_PRF_HEAD2 | RES_PRF_HEAD1 | RES_PRF_HEADX |
193 RES_PRF_QUES | RES_PRF_ANS |
194 RES_PRF_AUTH | RES_PRF_ADD;
195 INIT_LIST(nsrrs);
196
197 DPRINTF(("get the soa, and see if it has enough glue"));
198 if ((n = get_soa(statp, dname, class, opts, zname, zsize,
199 mname, sizeof mname, &nsrrs)) < 0 ||
200 ((opts & RES_EXHAUSTIVE) == 0 &&
201 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
202 goto done;
203
204 DPRINTF(("get the ns rrset and see if it has enough glue"));
205 if ((n = get_ns(statp, zname, class, opts, &nsrrs)) < 0 ||
206 ((opts & RES_EXHAUSTIVE) == 0 &&
207 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
208 goto done;
209
210 DPRINTF(("get the missing glue and see if it's finally enough"));
211 if ((n = get_glue(statp, class, opts, &nsrrs)) >= 0)
212 n = satisfy(statp, mname, &nsrrs, addrs, naddrs);
213
214 done:
215 DPRINTF(("FINISH n=%d (%s)", n, (n < 0) ? strerror(errno) : "OK"));
216 free_nsrrset(&nsrrs);
217 statp->pfcode = save_pfcode;
218 return (n);
219 }
220
221 /* Private. */
222
223 static int
224 satisfy(res_state statp, const char *mname, rrset_ns *nsrrsp,
225 union res_sockaddr_union *addrs, int naddrs)
226 {
227 rr_ns *nsrr;
228 int n, x;
229
230 n = 0;
231 nsrr = find_ns(nsrrsp, mname);
232 if (nsrr != NULL) {
233 x = add_addrs(statp, nsrr, addrs, naddrs);
234 addrs += x;
235 naddrs -= x;
236 n += x;
237 }
238 for (nsrr = HEAD(*nsrrsp);
239 nsrr != NULL && naddrs > 0;
240 nsrr = NEXT(nsrr, link))
241 if (ns_samename(nsrr->name, mname) != 1) {
242 x = add_addrs(statp, nsrr, addrs, naddrs);
243 addrs += x;
244 naddrs -= x;
245 n += x;
246 }
247 DPRINTF(("satisfy(%s): %d", mname, n));
248 return (n);
249 }
250
251 static int
252 add_addrs(res_state statp, rr_ns *nsrr,
253 union res_sockaddr_union *addrs, int naddrs)
254 {
255 rr_a *arr;
256 int n = 0;
257
258 for (arr = HEAD(nsrr->addrs); arr != NULL; arr = NEXT(arr, link)) {
259 if (naddrs <= 0)
260 return (0);
261 *addrs++ = arr->addr;
262 naddrs--;
263 n++;
264 }
265 DPRINTF(("add_addrs: %d", n));
266 return (n);
267 }
268
269 static int
270 get_soa(res_state statp, const char *dname, ns_class class, int opts,
271 char *zname, size_t zsize, char *mname, size_t msize,
272 rrset_ns *nsrrsp)
273 {
274 char tname[NS_MAXDNAME];
275 u_char *resp = NULL;
276 int n, i, ancount, nscount;
277 ns_sect sect;
278 ns_msg msg;
279 u_int rcode;
280
281 /*
282 * Find closest enclosing SOA, even if it's for the root zone.
283 */
284
285 /* First canonicalize dname (exactly one unescaped trailing "."). */
286 if (ns_makecanon(dname, tname, sizeof tname) < 0)
287 goto cleanup;
288 dname = tname;
289
290 resp = malloc(NS_MAXMSG);
291 if (resp == NULL)
292 goto cleanup;
293
294 /* Now grovel the subdomains, hunting for an SOA answer or auth. */
295 for (;;) {
296 /* Leading or inter-label '.' are skipped here. */
297 while (*dname == '.')
298 dname++;
299
300 /* Is there an SOA? */
301 n = do_query(statp, dname, class, ns_t_soa, resp, &msg);
302 if (n < 0) {
303 DPRINTF(("get_soa: do_query('%s', %s) failed (%d)",
304 dname, p_class(class), n));
305 goto cleanup;
306 }
307 if (n > 0) {
308 DPRINTF(("get_soa: CNAME or DNAME found"));
309 sect = ns_s_max, n = 0;
310 } else {
311 rcode = ns_msg_getflag(msg, ns_f_rcode);
312 ancount = ns_msg_count(msg, ns_s_an);
313 nscount = ns_msg_count(msg, ns_s_ns);
314 if (ancount > 0 && rcode == ns_r_noerror)
315 sect = ns_s_an, n = ancount;
316 else if (nscount > 0)
317 sect = ns_s_ns, n = nscount;
318 else
319 sect = ns_s_max, n = 0;
320 }
321 for (i = 0; i < n; i++) {
322 const char *t;
323 const u_char *rdata;
324 ns_rr rr;
325
326 if (ns_parserr(&msg, sect, i, &rr) < 0) {
327 DPRINTF(("get_soa: ns_parserr(%s, %d) failed",
328 p_section(sect, ns_o_query), i));
329 goto cleanup;
330 }
331 if (ns_rr_type(rr) == ns_t_cname ||
332 ns_rr_type(rr) == ns_t_dname)
333 break;
334 if (ns_rr_type(rr) != ns_t_soa ||
335 ns_rr_class(rr) != class)
336 continue;
337 t = ns_rr_name(rr);
338 switch (sect) {
339 case ns_s_an:
340 if (ns_samedomain(dname, t) == 0) {
341 DPRINTF(
342 ("get_soa: ns_samedomain('%s', '%s') == 0",
343 dname, t)
344 );
345 errno = EPROTOTYPE;
346 goto cleanup;
347 }
348 break;
349 case ns_s_ns:
350 if (ns_samename(dname, t) == 1 ||
351 ns_samedomain(dname, t) == 0) {
352 DPRINTF(
353 ("get_soa: ns_samename() || !ns_samedomain('%s', '%s')",
354 dname, t)
355 );
356 errno = EPROTOTYPE;
357 goto cleanup;
358 }
359 break;
360 default:
361 abort();
362 }
363 if (strlen(t) + 1 > zsize) {
364 DPRINTF(("get_soa: zname(%lu) too small (%lu)",
365 (unsigned long)zsize,
366 (unsigned long)strlen(t) + 1));
367 errno = EMSGSIZE;
368 goto cleanup;
369 }
370 strcpy(zname, t);
371 rdata = ns_rr_rdata(rr);
372 if (ns_name_uncompress(resp, ns_msg_end(msg), rdata,
373 mname, msize) < 0) {
374 DPRINTF(("get_soa: ns_name_uncompress failed")
375 );
376 goto cleanup;
377 }
378 if (save_ns(statp, &msg, ns_s_ns,
379 zname, class, opts, nsrrsp) < 0) {
380 DPRINTF(("get_soa: save_ns failed"));
381 goto cleanup;
382 }
383 free(resp);
384 return (0);
385 }
386
387 /* If we're out of labels, then not even "." has an SOA! */
388 if (*dname == '\0')
389 break;
390
391 /* Find label-terminating "."; top of loop will skip it. */
392 while (*dname != '.') {
393 if (*dname == '\\')
394 if (*++dname == '\0') {
395 errno = EMSGSIZE;
396 goto cleanup;
397 }
398 dname++;
399 }
400 }
401 DPRINTF(("get_soa: out of labels"));
402 errno = EDESTADDRREQ;
403 cleanup:
404 if (resp != NULL)
405 free(resp);
406 return (-1);
407 }
408
409 static int
410 get_ns(res_state statp, const char *zname, ns_class class, int opts,
411 rrset_ns *nsrrsp)
412 {
413 u_char *resp;
414 ns_msg msg;
415 int n;
416
417 resp = malloc(NS_MAXMSG);
418 if (resp == NULL)
419 return (-1);
420
421 /* Go and get the NS RRs for this zone. */
422 n = do_query(statp, zname, class, ns_t_ns, resp, &msg);
423 if (n != 0) {
424 DPRINTF(("get_ns: do_query('%s', %s) failed (%d)",
425 zname, p_class(class), n));
426 free(resp);
427 return (-1);
428 }
429
430 /* Remember the NS RRs and associated A RRs that came back. */
431 if (save_ns(statp, &msg, ns_s_an, zname, class, opts, nsrrsp) < 0) {
432 DPRINTF(("get_ns save_ns('%s', %s) failed",
433 zname, p_class(class)));
434 free(resp);
435 return (-1);
436 }
437
438 free(resp);
439 return (0);
440 }
441
442 static int
443 get_glue(res_state statp, ns_class class, int opts, rrset_ns *nsrrsp) {
444 rr_ns *nsrr, *nsrr_n;
445 u_char *resp;
446
447 resp = malloc(NS_MAXMSG);
448 if (resp == NULL)
449 return(-1);
450
451 /* Go and get the A RRs for each empty NS RR on our list. */
452 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = nsrr_n) {
453 ns_msg msg;
454 int n;
455
456 nsrr_n = NEXT(nsrr, link);
457
458 if ((nsrr->flags & RR_NS_HAVE_V4) == 0) {
459 n = do_query(statp, nsrr->name, class, ns_t_a,
460 resp, &msg);
461 if (n < 0) {
462 DPRINTF(
463 ("get_glue: do_query('%s', %s') failed",
464 nsrr->name, p_class(class)));
465 goto cleanup;
466 }
467 if (n > 0) {
468 DPRINTF((
469 "get_glue: do_query('%s', %s') CNAME or DNAME found",
470 nsrr->name, p_class(class)));
471 }
472 if (save_a(statp, &msg, ns_s_an, nsrr->name, class,
473 opts, nsrr) < 0) {
474 DPRINTF(("get_glue: save_r('%s', %s) failed",
475 nsrr->name, p_class(class)));
476 goto cleanup;
477 }
478 }
479
480 if ((nsrr->flags & RR_NS_HAVE_V6) == 0) {
481 n = do_query(statp, nsrr->name, class, ns_t_aaaa,
482 resp, &msg);
483 if (n < 0) {
484 DPRINTF(
485 ("get_glue: do_query('%s', %s') failed",
486 nsrr->name, p_class(class)));
487 goto cleanup;
488 }
489 if (n > 0) {
490 DPRINTF((
491 "get_glue: do_query('%s', %s') CNAME or DNAME found",
492 nsrr->name, p_class(class)));
493 }
494 if (save_a(statp, &msg, ns_s_an, nsrr->name, class,
495 opts, nsrr) < 0) {
496 DPRINTF(("get_glue: save_r('%s', %s) failed",
497 nsrr->name, p_class(class)));
498 goto cleanup;
499 }
500 }
501
502 /* If it's still empty, it's just chaff. */
503 if (EMPTY(nsrr->addrs)) {
504 DPRINTF(("get_glue: removing empty '%s' NS",
505 nsrr->name));
506 free_nsrr(nsrrsp, nsrr);
507 }
508 }
509 free(resp);
510 return (0);
511
512 cleanup:
513 free(resp);
514 return (-1);
515 }
516
517 static int
518 save_ns(res_state statp, ns_msg *msg, ns_sect sect,
519 const char *owner, ns_class class, int opts,
520 rrset_ns *nsrrsp)
521 {
522 int i;
523
524 for (i = 0; i < ns_msg_count(*msg, sect); i++) {
525 char tname[MAXDNAME];
526 const u_char *rdata;
527 rr_ns *nsrr;
528 ns_rr rr;
529
530 if (ns_parserr(msg, sect, i, &rr) < 0) {
531 DPRINTF(("save_ns: ns_parserr(%s, %d) failed",
532 p_section(sect, ns_o_query), i));
533 return (-1);
534 }
535 if (ns_rr_type(rr) != ns_t_ns ||
536 ns_rr_class(rr) != class ||
537 ns_samename(ns_rr_name(rr), owner) != 1)
538 continue;
539 nsrr = find_ns(nsrrsp, ns_rr_name(rr));
540 if (nsrr == NULL) {
541 nsrr = malloc(sizeof *nsrr);
542 if (nsrr == NULL) {
543 DPRINTF(("save_ns: malloc failed"));
544 return (-1);
545 }
546 rdata = ns_rr_rdata(rr);
547 if (ns_name_uncompress(ns_msg_base(*msg),
548 ns_msg_end(*msg), rdata,
549 tname, sizeof tname) < 0) {
550 DPRINTF(("save_ns: ns_name_uncompress failed")
551 );
552 free(nsrr);
553 return (-1);
554 }
555 nsrr->name = strdup(tname);
556 if (nsrr->name == NULL) {
557 DPRINTF(("save_ns: strdup failed"));
558 free(nsrr);
559 return (-1);
560 }
561 INIT_LINK(nsrr, link);
562 INIT_LIST(nsrr->addrs);
563 nsrr->flags = 0;
564 APPEND(*nsrrsp, nsrr, link);
565 }
566 if (save_a(statp, msg, ns_s_ar,
567 nsrr->name, class, opts, nsrr) < 0) {
568 DPRINTF(("save_ns: save_r('%s', %s) failed",
569 nsrr->name, p_class(class)));
570 return (-1);
571 }
572 }
573 return (0);
574 }
575
576 static int
577 save_a(res_state statp, ns_msg *msg, ns_sect sect,
578 const char *owner, ns_class class, int opts,
579 rr_ns *nsrr)
580 {
581 int i;
582
583 for (i = 0; i < ns_msg_count(*msg, sect); i++) {
584 ns_rr rr;
585 rr_a *arr;
586
587 if (ns_parserr(msg, sect, i, &rr) < 0) {
588 DPRINTF(("save_a: ns_parserr(%s, %d) failed",
589 p_section(sect, ns_o_query), i));
590 return (-1);
591 }
592 if ((ns_rr_type(rr) != ns_t_a &&
593 ns_rr_type(rr) != ns_t_aaaa) ||
594 ns_rr_class(rr) != class ||
595 ns_samename(ns_rr_name(rr), owner) != 1 ||
596 ns_rr_rdlen(rr) != NS_INADDRSZ)
597 continue;
598 if ((opts & RES_IPV6ONLY) != 0 && ns_rr_type(rr) != ns_t_aaaa)
599 continue;
600 if ((opts & RES_IPV4ONLY) != 0 && ns_rr_type(rr) != ns_t_a)
601 continue;
602 arr = malloc(sizeof *arr);
603 if (arr == NULL) {
604 DPRINTF(("save_a: malloc failed"));
605 return (-1);
606 }
607 INIT_LINK(arr, link);
608 memset(&arr->addr, 0, sizeof(arr->addr));
609 switch (ns_rr_type(rr)) {
610 case ns_t_a:
611 arr->addr.sin.sin_family = AF_INET;
612 #ifdef HAVE_SA_LEN
613 arr->addr.sin.sin_len = sizeof(arr->addr.sin);
614 #endif
615 memcpy(&arr->addr.sin.sin_addr, ns_rr_rdata(rr),
616 NS_INADDRSZ);
617 arr->addr.sin.sin_port = htons(NAMESERVER_PORT);
618 nsrr->flags |= RR_NS_HAVE_V4;
619 break;
620 case ns_t_aaaa:
621 arr->addr.sin6.sin6_family = AF_INET6;
622 #ifdef HAVE_SA_LEN
623 arr->addr.sin6.sin6_len = sizeof(arr->addr.sin6);
624 #endif
625 memcpy(&arr->addr.sin6.sin6_addr, ns_rr_rdata(rr), 16);
626 arr->addr.sin.sin_port = htons(NAMESERVER_PORT);
627 nsrr->flags |= RR_NS_HAVE_V6;
628 break;
629 default:
630 abort();
631 }
632 APPEND(nsrr->addrs, arr, link);
633 }
634 return (0);
635 }
636
637 static void
638 free_nsrrset(rrset_ns *nsrrsp) {
639 rr_ns *nsrr;
640
641 while ((nsrr = HEAD(*nsrrsp)) != NULL)
642 free_nsrr(nsrrsp, nsrr);
643 }
644
645 static void
646 free_nsrr(rrset_ns *nsrrsp, rr_ns *nsrr) {
647 rr_a *arr;
648 char *tmp;
649
650 while ((arr = HEAD(nsrr->addrs)) != NULL) {
651 UNLINK(nsrr->addrs, arr, link);
652 free(arr);
653 }
654 DE_CONST(nsrr->name, tmp);
655 free(tmp);
656 UNLINK(*nsrrsp, nsrr, link);
657 free(nsrr);
658 }
659
660 static rr_ns *
661 find_ns(rrset_ns *nsrrsp, const char *dname) {
662 rr_ns *nsrr;
663
664 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = NEXT(nsrr, link))
665 if (ns_samename(nsrr->name, dname) == 1)
666 return (nsrr);
667 return (NULL);
668 }
669
670 static int
671 do_query(res_state statp, const char *dname, ns_class class, ns_type qtype,
672 u_char *resp, ns_msg *msg)
673 {
674 u_char req[NS_PACKETSZ];
675 int i, n;
676
677 n = res_nmkquery(statp, ns_o_query, dname, class, qtype,
678 NULL, 0, NULL, req, NS_PACKETSZ);
679 if (n < 0) {
680 DPRINTF(("do_query: res_nmkquery failed"));
681 return (-1);
682 }
683 n = res_nsend(statp, req, n, resp, NS_MAXMSG);
684 if (n < 0) {
685 DPRINTF(("do_query: res_nsend failed"));
686 return (-1);
687 }
688 if (n == 0) {
689 DPRINTF(("do_query: res_nsend returned 0"));
690 errno = EMSGSIZE;
691 return (-1);
692 }
693 if (ns_initparse(resp, n, msg) < 0) {
694 DPRINTF(("do_query: ns_initparse failed"));
695 return (-1);
696 }
697 n = 0;
698 for (i = 0; i < ns_msg_count(*msg, ns_s_an); i++) {
699 ns_rr rr;
700
701 if (ns_parserr(msg, ns_s_an, i, &rr) < 0) {
702 DPRINTF(("do_query: ns_parserr failed"));
703 return (-1);
704 }
705 n += (ns_rr_class(rr) == class &&
706 (ns_rr_type(rr) == ns_t_cname ||
707 ns_rr_type(rr) == ns_t_dname));
708 }
709 return (n);
710 }
711
712 static void
713 res_dprintf(const char *fmt, ...) {
714 va_list ap;
715
716 va_start(ap, fmt);
717 fputs(";; res_findzonecut: ", stderr);
718 vfprintf(stderr, fmt, ap);
719 fputc('\n', stderr);
720 va_end(ap);
721 }
722
723 /*! \file */
DragonFly BSD