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libc: Move unused rcsid[] etc. constants into the
[dragonfly.git] / lib / libc / resolv / res_findzonecut.c
blob31f71f1628506b0b25aadebb5f660fca59d94260
1 /*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1999 by Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 *
17 * $Id: res_findzonecut.c,v 1.10 2005/10/11 00:10:16 marka Exp $
18 */
19
20 /* Import. */
21
22 #include "port_before.h"
23
24 #include <sys/param.h>
25 #include <sys/socket.h>
26 #include <sys/time.h>
27
28 #include <netinet/in.h>
29 #include <arpa/inet.h>
30 #include <arpa/nameser.h>
31
32 #include <errno.h>
33 #include <limits.h>
34 #include <netdb.h>
35 #include <stdarg.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39
40 #include "isc/list.h"
41
42 #include "port_after.h"
43
44 #include <resolv.h>
45
46 /* Data structures. */
47
48 typedef struct rr_a {
49 LINK(struct rr_a) link;
50 union res_sockaddr_union addr;
51 } rr_a;
52 typedef LIST(rr_a) rrset_a;
53
54 typedef struct rr_ns {
55 LINK(struct rr_ns) link;
56 const char * name;
57 unsigned int flags;
58 rrset_a addrs;
59 } rr_ns;
60 typedef LIST(rr_ns) rrset_ns;
61
62 #define RR_NS_HAVE_V4 0x01
63 #define RR_NS_HAVE_V6 0x02
64
65 /* Forward. */
66
67 static int satisfy(res_state, const char *, rrset_ns *,
68 union res_sockaddr_union *, int);
69 static int add_addrs(res_state, rr_ns *,
70 union res_sockaddr_union *, int);
71 static int get_soa(res_state, const char *, ns_class, int,
72 char *, size_t, char *, size_t,
73 rrset_ns *);
74 static int get_ns(res_state, const char *, ns_class, int, rrset_ns *);
75 static int get_glue(res_state, ns_class, int, rrset_ns *);
76 static int save_ns(res_state, ns_msg *, ns_sect,
77 const char *, ns_class, int, rrset_ns *);
78 static int save_a(res_state, ns_msg *, ns_sect,
79 const char *, ns_class, int, rr_ns *);
80 static void free_nsrrset(rrset_ns *);
81 static void free_nsrr(rrset_ns *, rr_ns *);
82 static rr_ns * find_ns(rrset_ns *, const char *);
83 static int do_query(res_state, const char *, ns_class, ns_type,
84 u_char *, ns_msg *);
85 static void res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
86
87 /* Macros. */
88
89 #define DPRINTF(x) do {\
90 int save_errno = errno; \
91 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
92 errno = save_errno; \
93 } while (0)
94
95 /* Public. */
96
97 /*%
98 * find enclosing zone for a <dname,class>, and some server addresses
99 *
100 * parameters:
101 *\li res - resolver context to work within (is modified)
102 *\li dname - domain name whose enclosing zone is desired
103 *\li class - class of dname (and its enclosing zone)
104 *\li zname - found zone name
105 *\li zsize - allocated size of zname
106 *\li addrs - found server addresses
107 *\li naddrs - max number of addrs
108 *
109 * return values:
110 *\li < 0 - an error occurred (check errno)
111 *\li = 0 - zname is now valid, but addrs[] wasn't changed
112 *\li > 0 - zname is now valid, and return value is number of addrs[] found
113 *
114 * notes:
115 *\li this function calls res_nsend() which means it depends on correctly
116 * functioning recursive nameservers (usually defined in /etc/resolv.conf
117 * or its local equivilent).
118 *
119 *\li we start by asking for an SOA<dname,class>. if we get one as an
120 * answer, that just means <dname,class> is a zone top, which is fine.
121 * more than likely we'll be told to go pound sand, in the form of a
122 * negative answer.
123 *
124 *\li note that we are not prepared to deal with referrals since that would
125 * only come from authority servers and our correctly functioning local
126 * recursive server would have followed the referral and got us something
127 * more definite.
128 *
129 *\li if the authority section contains an SOA, this SOA should also be the
130 * closest enclosing zone, since any intermediary zone cuts would've been
131 * returned as referrals and dealt with by our correctly functioning local
132 * recursive name server. but an SOA in the authority section should NOT
133 * match our dname (since that would have been returned in the answer
134 * section). an authority section SOA has to be "above" our dname.
135 *
136 *\li however, since authority section SOA's were once optional, it's
137 * possible that we'll have to go hunting for the enclosing SOA by
138 * ripping labels off the front of our dname -- this is known as "doing
139 * it the hard way."
140 *
141 *\li ultimately we want some server addresses, which are ideally the ones
142 * pertaining to the SOA.MNAME, but only if there is a matching NS RR.
143 * so the second phase (after we find an SOA) is to go looking for the
144 * NS RRset for that SOA's zone.
145 *
146 *\li no answer section processed by this code is allowed to contain CNAME
147 * or DNAME RR's. for the SOA query this means we strip a label and
148 * keep going. for the NS and A queries this means we just give up.
149 */
150
151 #ifndef _LIBC
152 int
153 res_findzonecut(res_state statp, const char *dname, ns_class class, int opts,
154 char *zname, size_t zsize, struct in_addr *addrs, int naddrs)
155 {
156 int result, i;
157 union res_sockaddr_union *u;
158
159
160 opts |= RES_IPV4ONLY;
161 opts &= ~RES_IPV6ONLY;
162
163 u = calloc(naddrs, sizeof(*u));
164 if (u == NULL)
165 return(-1);
166
167 result = res_findzonecut2(statp, dname, class, opts, zname, zsize,
168 u, naddrs);
169
170 for (i = 0; i < result; i++) {
171 addrs[i] = u[i].sin.sin_addr;
172 }
173 free(u);
174 return (result);
175 }
176 #endif
177 int
178 res_findzonecut2(res_state statp, const char *dname, ns_class class, int opts,
179 char *zname, size_t zsize, union res_sockaddr_union *addrs,
180 int naddrs)
181 {
182 char mname[NS_MAXDNAME];
183 u_long save_pfcode;
184 rrset_ns nsrrs;
185 int n;
186
187 DPRINTF(("START dname='%s' class=%s, zsize=%ld, naddrs=%d",
188 dname, p_class(class), (long)zsize, naddrs));
189 save_pfcode = statp->pfcode;
190 statp->pfcode |= RES_PRF_HEAD2 | RES_PRF_HEAD1 | RES_PRF_HEADX |
191 RES_PRF_QUES | RES_PRF_ANS |
192 RES_PRF_AUTH | RES_PRF_ADD;
193 INIT_LIST(nsrrs);
194
195 DPRINTF(("get the soa, and see if it has enough glue"));
196 if ((n = get_soa(statp, dname, class, opts, zname, zsize,
197 mname, sizeof mname, &nsrrs)) < 0 ||
198 ((opts & RES_EXHAUSTIVE) == 0 &&
199 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
200 goto done;
201
202 DPRINTF(("get the ns rrset and see if it has enough glue"));
203 if ((n = get_ns(statp, zname, class, opts, &nsrrs)) < 0 ||
204 ((opts & RES_EXHAUSTIVE) == 0 &&
205 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
206 goto done;
207
208 DPRINTF(("get the missing glue and see if it's finally enough"));
209 if ((n = get_glue(statp, class, opts, &nsrrs)) >= 0)
210 n = satisfy(statp, mname, &nsrrs, addrs, naddrs);
211
212 done:
213 DPRINTF(("FINISH n=%d (%s)", n, (n < 0) ? strerror(errno) : "OK"));
214 free_nsrrset(&nsrrs);
215 statp->pfcode = save_pfcode;
216 return (n);
217 }
218
219 /* Private. */
220
221 static int
222 satisfy(res_state statp, const char *mname, rrset_ns *nsrrsp,
223 union res_sockaddr_union *addrs, int naddrs)
224 {
225 rr_ns *nsrr;
226 int n, x;
227
228 n = 0;
229 nsrr = find_ns(nsrrsp, mname);
230 if (nsrr != NULL) {
231 x = add_addrs(statp, nsrr, addrs, naddrs);
232 addrs += x;
233 naddrs -= x;
234 n += x;
235 }
236 for (nsrr = HEAD(*nsrrsp);
237 nsrr != NULL && naddrs > 0;
238 nsrr = NEXT(nsrr, link))
239 if (ns_samename(nsrr->name, mname) != 1) {
240 x = add_addrs(statp, nsrr, addrs, naddrs);
241 addrs += x;
242 naddrs -= x;
243 n += x;
244 }
245 DPRINTF(("satisfy(%s): %d", mname, n));
246 return (n);
247 }
248
249 static int
250 add_addrs(res_state statp, rr_ns *nsrr,
251 union res_sockaddr_union *addrs, int naddrs)
252 {
253 rr_a *arr;
254 int n = 0;
255
256 for (arr = HEAD(nsrr->addrs); arr != NULL; arr = NEXT(arr, link)) {
257 if (naddrs <= 0)
258 return (0);
259 *addrs++ = arr->addr;
260 naddrs--;
261 n++;
262 }
263 DPRINTF(("add_addrs: %d", n));
264 return (n);
265 }
266
267 static int
268 get_soa(res_state statp, const char *dname, ns_class class, int opts,
269 char *zname, size_t zsize, char *mname, size_t msize,
270 rrset_ns *nsrrsp)
271 {
272 char tname[NS_MAXDNAME];
273 u_char *resp = NULL;
274 int n, i, ancount, nscount;
275 ns_sect sect;
276 ns_msg msg;
277 u_int rcode;
278
279 /*
280 * Find closest enclosing SOA, even if it's for the root zone.
281 */
282
283 /* First canonicalize dname (exactly one unescaped trailing "."). */
284 if (ns_makecanon(dname, tname, sizeof tname) < 0)
285 goto cleanup;
286 dname = tname;
287
288 resp = malloc(NS_MAXMSG);
289 if (resp == NULL)
290 goto cleanup;
291
292 /* Now grovel the subdomains, hunting for an SOA answer or auth. */
293 for (;;) {
294 /* Leading or inter-label '.' are skipped here. */
295 while (*dname == '.')
296 dname++;
297
298 /* Is there an SOA? */
299 n = do_query(statp, dname, class, ns_t_soa, resp, &msg);
300 if (n < 0) {
301 DPRINTF(("get_soa: do_query('%s', %s) failed (%d)",
302 dname, p_class(class), n));
303 goto cleanup;
304 }
305 if (n > 0) {
306 DPRINTF(("get_soa: CNAME or DNAME found"));
307 sect = ns_s_max, n = 0;
308 } else {
309 rcode = ns_msg_getflag(msg, ns_f_rcode);
310 ancount = ns_msg_count(msg, ns_s_an);
311 nscount = ns_msg_count(msg, ns_s_ns);
312 if (ancount > 0 && rcode == ns_r_noerror)
313 sect = ns_s_an, n = ancount;
314 else if (nscount > 0)
315 sect = ns_s_ns, n = nscount;
316 else
317 sect = ns_s_max, n = 0;
318 }
319 for (i = 0; i < n; i++) {
320 const char *t;
321 const u_char *rdata;
322 ns_rr rr;
323
324 if (ns_parserr(&msg, sect, i, &rr) < 0) {
325 DPRINTF(("get_soa: ns_parserr(%s, %d) failed",
326 p_section(sect, ns_o_query), i));
327 goto cleanup;
328 }
329 if (ns_rr_type(rr) == ns_t_cname ||
330 ns_rr_type(rr) == ns_t_dname)
331 break;
332 if (ns_rr_type(rr) != ns_t_soa ||
333 ns_rr_class(rr) != class)
334 continue;
335 t = ns_rr_name(rr);
336 switch (sect) {
337 case ns_s_an:
338 if (ns_samedomain(dname, t) == 0) {
339 DPRINTF(
340 ("get_soa: ns_samedomain('%s', '%s') == 0",
341 dname, t)
342 );
343 errno = EPROTOTYPE;
344 goto cleanup;
345 }
346 break;
347 case ns_s_ns:
348 if (ns_samename(dname, t) == 1 ||
349 ns_samedomain(dname, t) == 0) {
350 DPRINTF(
351 ("get_soa: ns_samename() || !ns_samedomain('%s', '%s')",
352 dname, t)
353 );
354 errno = EPROTOTYPE;
355 goto cleanup;
356 }
357 break;
358 default:
359 abort();
360 }
361 if (strlen(t) + 1 > zsize) {
362 DPRINTF(("get_soa: zname(%lu) too small (%lu)",
363 (unsigned long)zsize,
364 (unsigned long)strlen(t) + 1));
365 errno = EMSGSIZE;
366 goto cleanup;
367 }
368 strcpy(zname, t);
369 rdata = ns_rr_rdata(rr);
370 if (ns_name_uncompress(resp, ns_msg_end(msg), rdata,
371 mname, msize) < 0) {
372 DPRINTF(("get_soa: ns_name_uncompress failed")
373 );
374 goto cleanup;
375 }
376 if (save_ns(statp, &msg, ns_s_ns,
377 zname, class, opts, nsrrsp) < 0) {
378 DPRINTF(("get_soa: save_ns failed"));
379 goto cleanup;
380 }
381 free(resp);
382 return (0);
383 }
384
385 /* If we're out of labels, then not even "." has an SOA! */
386 if (*dname == '\0')
387 break;
388
389 /* Find label-terminating "."; top of loop will skip it. */
390 while (*dname != '.') {
391 if (*dname == '\\')
392 if (*++dname == '\0') {
393 errno = EMSGSIZE;
394 goto cleanup;
395 }
396 dname++;
397 }
398 }
399 DPRINTF(("get_soa: out of labels"));
400 errno = EDESTADDRREQ;
401 cleanup:
402 if (resp != NULL)
403 free(resp);
404 return (-1);
405 }
406
407 static int
408 get_ns(res_state statp, const char *zname, ns_class class, int opts,
409 rrset_ns *nsrrsp)
410 {
411 u_char *resp;
412 ns_msg msg;
413 int n;
414
415 resp = malloc(NS_MAXMSG);
416 if (resp == NULL)
417 return (-1);
418
419 /* Go and get the NS RRs for this zone. */
420 n = do_query(statp, zname, class, ns_t_ns, resp, &msg);
421 if (n != 0) {
422 DPRINTF(("get_ns: do_query('%s', %s) failed (%d)",
423 zname, p_class(class), n));
424 free(resp);
425 return (-1);
426 }
427
428 /* Remember the NS RRs and associated A RRs that came back. */
429 if (save_ns(statp, &msg, ns_s_an, zname, class, opts, nsrrsp) < 0) {
430 DPRINTF(("get_ns save_ns('%s', %s) failed",
431 zname, p_class(class)));
432 free(resp);
433 return (-1);
434 }
435
436 free(resp);
437 return (0);
438 }
439
440 static int
441 get_glue(res_state statp, ns_class class, int opts, rrset_ns *nsrrsp) {
442 rr_ns *nsrr, *nsrr_n;
443 u_char *resp;
444
445 resp = malloc(NS_MAXMSG);
446 if (resp == NULL)
447 return(-1);
448
449 /* Go and get the A RRs for each empty NS RR on our list. */
450 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = nsrr_n) {
451 ns_msg msg;
452 int n;
453
454 nsrr_n = NEXT(nsrr, link);
455
456 if ((nsrr->flags & RR_NS_HAVE_V4) == 0) {
457 n = do_query(statp, nsrr->name, class, ns_t_a,
458 resp, &msg);
459 if (n < 0) {
460 DPRINTF(
461 ("get_glue: do_query('%s', %s') failed",
462 nsrr->name, p_class(class)));
463 goto cleanup;
464 }
465 if (n > 0) {
466 DPRINTF((
467 "get_glue: do_query('%s', %s') CNAME or DNAME found",
468 nsrr->name, p_class(class)));
469 }
470 if (save_a(statp, &msg, ns_s_an, nsrr->name, class,
471 opts, nsrr) < 0) {
472 DPRINTF(("get_glue: save_r('%s', %s) failed",
473 nsrr->name, p_class(class)));
474 goto cleanup;
475 }
476 }
477
478 if ((nsrr->flags & RR_NS_HAVE_V6) == 0) {
479 n = do_query(statp, nsrr->name, class, ns_t_aaaa,
480 resp, &msg);
481 if (n < 0) {
482 DPRINTF(
483 ("get_glue: do_query('%s', %s') failed",
484 nsrr->name, p_class(class)));
485 goto cleanup;
486 }
487 if (n > 0) {
488 DPRINTF((
489 "get_glue: do_query('%s', %s') CNAME or DNAME found",
490 nsrr->name, p_class(class)));
491 }
492 if (save_a(statp, &msg, ns_s_an, nsrr->name, class,
493 opts, nsrr) < 0) {
494 DPRINTF(("get_glue: save_r('%s', %s) failed",
495 nsrr->name, p_class(class)));
496 goto cleanup;
497 }
498 }
499
500 /* If it's still empty, it's just chaff. */
501 if (EMPTY(nsrr->addrs)) {
502 DPRINTF(("get_glue: removing empty '%s' NS",
503 nsrr->name));
504 free_nsrr(nsrrsp, nsrr);
505 }
506 }
507 free(resp);
508 return (0);
509
510 cleanup:
511 free(resp);
512 return (-1);
513 }
514
515 static int
516 save_ns(res_state statp, ns_msg *msg, ns_sect sect,
517 const char *owner, ns_class class, int opts,
518 rrset_ns *nsrrsp)
519 {
520 int i;
521
522 for (i = 0; i < ns_msg_count(*msg, sect); i++) {
523 char tname[MAXDNAME];
524 const u_char *rdata;
525 rr_ns *nsrr;
526 ns_rr rr;
527
528 if (ns_parserr(msg, sect, i, &rr) < 0) {
529 DPRINTF(("save_ns: ns_parserr(%s, %d) failed",
530 p_section(sect, ns_o_query), i));
531 return (-1);
532 }
533 if (ns_rr_type(rr) != ns_t_ns ||
534 ns_rr_class(rr) != class ||
535 ns_samename(ns_rr_name(rr), owner) != 1)
536 continue;
537 nsrr = find_ns(nsrrsp, ns_rr_name(rr));
538 if (nsrr == NULL) {
539 nsrr = malloc(sizeof *nsrr);
540 if (nsrr == NULL) {
541 DPRINTF(("save_ns: malloc failed"));
542 return (-1);
543 }
544 rdata = ns_rr_rdata(rr);
545 if (ns_name_uncompress(ns_msg_base(*msg),
546 ns_msg_end(*msg), rdata,
547 tname, sizeof tname) < 0) {
548 DPRINTF(("save_ns: ns_name_uncompress failed")
549 );
550 free(nsrr);
551 return (-1);
552 }
553 nsrr->name = strdup(tname);
554 if (nsrr->name == NULL) {
555 DPRINTF(("save_ns: strdup failed"));
556 free(nsrr);
557 return (-1);
558 }
559 INIT_LINK(nsrr, link);
560 INIT_LIST(nsrr->addrs);
561 nsrr->flags = 0;
562 APPEND(*nsrrsp, nsrr, link);
563 }
564 if (save_a(statp, msg, ns_s_ar,
565 nsrr->name, class, opts, nsrr) < 0) {
566 DPRINTF(("save_ns: save_r('%s', %s) failed",
567 nsrr->name, p_class(class)));
568 return (-1);
569 }
570 }
571 return (0);
572 }
573
574 static int
575 save_a(res_state statp, ns_msg *msg, ns_sect sect,
576 const char *owner, ns_class class, int opts,
577 rr_ns *nsrr)
578 {
579 int i;
580
581 for (i = 0; i < ns_msg_count(*msg, sect); i++) {
582 ns_rr rr;
583 rr_a *arr;
584
585 if (ns_parserr(msg, sect, i, &rr) < 0) {
586 DPRINTF(("save_a: ns_parserr(%s, %d) failed",
587 p_section(sect, ns_o_query), i));
588 return (-1);
589 }
590 if ((ns_rr_type(rr) != ns_t_a &&
591 ns_rr_type(rr) != ns_t_aaaa) ||
592 ns_rr_class(rr) != class ||
593 ns_samename(ns_rr_name(rr), owner) != 1 ||
594 ns_rr_rdlen(rr) != NS_INADDRSZ)
595 continue;
596 if ((opts & RES_IPV6ONLY) != 0 && ns_rr_type(rr) != ns_t_aaaa)
597 continue;
598 if ((opts & RES_IPV4ONLY) != 0 && ns_rr_type(rr) != ns_t_a)
599 continue;
600 arr = malloc(sizeof *arr);
601 if (arr == NULL) {
602 DPRINTF(("save_a: malloc failed"));
603 return (-1);
604 }
605 INIT_LINK(arr, link);
606 memset(&arr->addr, 0, sizeof(arr->addr));
607 switch (ns_rr_type(rr)) {
608 case ns_t_a:
609 arr->addr.sin.sin_family = AF_INET;
610 #ifdef HAVE_SA_LEN
611 arr->addr.sin.sin_len = sizeof(arr->addr.sin);
612 #endif
613 memcpy(&arr->addr.sin.sin_addr, ns_rr_rdata(rr),
614 NS_INADDRSZ);
615 arr->addr.sin.sin_port = htons(NAMESERVER_PORT);
616 nsrr->flags |= RR_NS_HAVE_V4;
617 break;
618 case ns_t_aaaa:
619 arr->addr.sin6.sin6_family = AF_INET6;
620 #ifdef HAVE_SA_LEN
621 arr->addr.sin6.sin6_len = sizeof(arr->addr.sin6);
622 #endif
623 memcpy(&arr->addr.sin6.sin6_addr, ns_rr_rdata(rr), 16);
624 arr->addr.sin.sin_port = htons(NAMESERVER_PORT);
625 nsrr->flags |= RR_NS_HAVE_V6;
626 break;
627 default:
628 abort();
629 }
630 APPEND(nsrr->addrs, arr, link);
631 }
632 return (0);
633 }
634
635 static void
636 free_nsrrset(rrset_ns *nsrrsp) {
637 rr_ns *nsrr;
638
639 while ((nsrr = HEAD(*nsrrsp)) != NULL)
640 free_nsrr(nsrrsp, nsrr);
641 }
642
643 static void
644 free_nsrr(rrset_ns *nsrrsp, rr_ns *nsrr) {
645 rr_a *arr;
646 char *tmp;
647
648 while ((arr = HEAD(nsrr->addrs)) != NULL) {
649 UNLINK(nsrr->addrs, arr, link);
650 free(arr);
651 }
652 DE_CONST(nsrr->name, tmp);
653 free(tmp);
654 UNLINK(*nsrrsp, nsrr, link);
655 free(nsrr);
656 }
657
658 static rr_ns *
659 find_ns(rrset_ns *nsrrsp, const char *dname) {
660 rr_ns *nsrr;
661
662 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = NEXT(nsrr, link))
663 if (ns_samename(nsrr->name, dname) == 1)
664 return (nsrr);
665 return (NULL);
666 }
667
668 static int
669 do_query(res_state statp, const char *dname, ns_class class, ns_type qtype,
670 u_char *resp, ns_msg *msg)
671 {
672 u_char req[NS_PACKETSZ];
673 int i, n;
674
675 n = res_nmkquery(statp, ns_o_query, dname, class, qtype,
676 NULL, 0, NULL, req, NS_PACKETSZ);
677 if (n < 0) {
678 DPRINTF(("do_query: res_nmkquery failed"));
679 return (-1);
680 }
681 n = res_nsend(statp, req, n, resp, NS_MAXMSG);
682 if (n < 0) {
683 DPRINTF(("do_query: res_nsend failed"));
684 return (-1);
685 }
686 if (n == 0) {
687 DPRINTF(("do_query: res_nsend returned 0"));
688 errno = EMSGSIZE;
689 return (-1);
690 }
691 if (ns_initparse(resp, n, msg) < 0) {
692 DPRINTF(("do_query: ns_initparse failed"));
693 return (-1);
694 }
695 n = 0;
696 for (i = 0; i < ns_msg_count(*msg, ns_s_an); i++) {
697 ns_rr rr;
698
699 if (ns_parserr(msg, ns_s_an, i, &rr) < 0) {
700 DPRINTF(("do_query: ns_parserr failed"));
701 return (-1);
702 }
703 n += (ns_rr_class(rr) == class &&
704 (ns_rr_type(rr) == ns_t_cname ||
705 ns_rr_type(rr) == ns_t_dname));
706 }
707 return (n);
708 }
709
710 static void
711 res_dprintf(const char *fmt, ...) {
712 va_list ap;
713
714 va_start(ap, fmt);
715 fputs(";; res_findzonecut: ", stderr);
716 vfprintf(stderr, fmt, ap);
717 fputc('\n', stderr);
718 va_end(ap);
719 }
720
721 /*! \file */
DragonFly BSD