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 $";
3 #endif /* not lint */
4
5 /*-
6 * SPDX-License-Identifier: ISC
7 *
8 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
9 * Copyright (c) 1999 by Internet Software Consortium.
10 *
11 * Permission to use, copy, modify, and distribute this software for any
12 * purpose with or without fee is hereby granted, provided that the above
13 * copyright notice and this permission notice appear in all copies.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
16 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
17 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
18 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
21 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22 */
23
24 #include <sys/cdefs.h>
25 __FBSDID("$FreeBSD$");
26
27 /* Import. */
28
29 #include "port_before.h"
30
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 #include <sys/time.h>
34
35 #include <netinet/in.h>
36 #include <arpa/inet.h>
37 #include <arpa/nameser.h>
38
39 #include <errno.h>
40 #include <limits.h>
41 #include <netdb.h>
42 #include <stdarg.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46
47 #include <isc/list.h>
48
49 #include "port_after.h"
50
51 #include <resolv.h>
52
53 /* Data structures. */
54
55 typedef struct rr_a {
56 LINK(struct rr_a) link;
57 union res_sockaddr_union addr;
58 } rr_a;
59 typedef LIST(rr_a) rrset_a;
60
61 typedef struct rr_ns {
62 LINK(struct rr_ns) link;
63 const char * name;
64 unsigned int flags;
65 rrset_a addrs;
66 } rr_ns;
67 typedef LIST(rr_ns) rrset_ns;
68
69 #define RR_NS_HAVE_V4 0x01
70 #define RR_NS_HAVE_V6 0x02
71
72 /* Forward. */
73
74 static int satisfy(res_state, const char *, rrset_ns *,
75 union res_sockaddr_union *, int);
76 static int add_addrs(res_state, rr_ns *,
77 union res_sockaddr_union *, int);
78 static int get_soa(res_state, const char *, ns_class, int,
79 char *, size_t, char *, size_t,
80 rrset_ns *);
81 static int get_ns(res_state, const char *, ns_class, int, rrset_ns *);
82 static int get_glue(res_state, ns_class, int, rrset_ns *);
83 static int save_ns(res_state, ns_msg *, ns_sect,
84 const char *, ns_class, int, rrset_ns *);
85 static int save_a(res_state, ns_msg *, ns_sect,
86 const char *, ns_class, int, rr_ns *);
87 static void free_nsrrset(rrset_ns *);
88 static void free_nsrr(rrset_ns *, rr_ns *);
89 static rr_ns * find_ns(rrset_ns *, const char *);
90 static int do_query(res_state, const char *, ns_class, ns_type,
91 u_char *, ns_msg *);
92 static void res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
93
94 /* Macros. */
95
96 #define DPRINTF(x) do {\
97 int save_errno = errno; \
98 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
99 errno = save_errno; \
100 } while (0)
101
102 /* Public. */
103
104 /*%
105 * find enclosing zone for a <dname,class>, and some server addresses
106 *
107 * parameters:
108 *\li res - resolver context to work within (is modified)
109 *\li dname - domain name whose enclosing zone is desired
110 *\li class - class of dname (and its enclosing zone)
111 *\li zname - found zone name
112 *\li zsize - allocated size of zname
113 *\li addrs - found server addresses
114 *\li naddrs - max number of addrs
115 *
116 * return values:
117 *\li < 0 - an error occurred (check errno)
118 *\li = 0 - zname is now valid, but addrs[] wasn't changed
119 *\li > 0 - zname is now valid, and return value is number of addrs[] found
120 *
121 * notes:
122 *\li this function calls res_nsend() which means it depends on correctly
123 * functioning recursive nameservers (usually defined in /etc/resolv.conf
124 * or its local equivalent).
125 *
126 *\li we start by asking for an SOA<dname,class>. if we get one as an
127 * answer, that just means <dname,class> is a zone top, which is fine.
128 * more than likely we'll be told to go pound sand, in the form of a
129 * negative answer.
130 *
131 *\li note that we are not prepared to deal with referrals since that would
132 * only come from authority servers and our correctly functioning local
133 * recursive server would have followed the referral and got us something
134 * more definite.
135 *
136 *\li if the authority section contains an SOA, this SOA should also be the
137 * closest enclosing zone, since any intermediary zone cuts would've been
138 * returned as referrals and dealt with by our correctly functioning local
139 * recursive name server. but an SOA in the authority section should NOT
140 * match our dname (since that would have been returned in the answer
141 * section). an authority section SOA has to be "above" our dname.
142 *
143 *\li however, since authority section SOA's were once optional, it's
144 * possible that we'll have to go hunting for the enclosing SOA by
145 * ripping labels off the front of our dname -- this is known as "doing
146 * it the hard way."
147 *
148 *\li ultimately we want some server addresses, which are ideally the ones
149 * pertaining to the SOA.MNAME, but only if there is a matching NS RR.
150 * so the second phase (after we find an SOA) is to go looking for the
151 * NS RRset for that SOA's zone.
152 *
153 *\li no answer section processed by this code is allowed to contain CNAME
154 * or DNAME RR's. for the SOA query this means we strip a label and
155 * keep going. for the NS and A queries this means we just give up.
156 */
157
158 #ifndef _LIBC
159 int
res_findzonecut(res_state statp,const char * dname,ns_class class,int opts,char * zname,size_t zsize,struct in_addr * addrs,int naddrs)160 res_findzonecut(res_state statp, const char *dname, ns_class class, int opts,
161 char *zname, size_t zsize, struct in_addr *addrs, int naddrs)
162 {
163 int result, i;
164 union res_sockaddr_union *u;
165
166
167 opts |= RES_IPV4ONLY;
168 opts &= ~RES_IPV6ONLY;
169
170 u = calloc(naddrs, sizeof(*u));
171 if (u == NULL)
172 return(-1);
173
174 result = res_findzonecut2(statp, dname, class, opts, zname, zsize,
175 u, naddrs);
176
177 for (i = 0; i < result; i++) {
178 addrs[i] = u[i].sin.sin_addr;
179 }
180 free(u);
181 return (result);
182 }
183 #endif
184
185 int
res_findzonecut2(res_state statp,const char * dname,ns_class class,int opts,char * zname,size_t zsize,union res_sockaddr_union * addrs,int naddrs)186 res_findzonecut2(res_state statp, const char *dname, ns_class class, int opts,
187 char *zname, size_t zsize, union res_sockaddr_union *addrs,
188 int naddrs)
189 {
190 char mname[NS_MAXDNAME];
191 u_long save_pfcode;
192 rrset_ns nsrrs;
193 int n;
194
195 DPRINTF(("START dname='%s' class=%s, zsize=%ld, naddrs=%d",
196 dname, p_class(class), (long)zsize, naddrs));
197 save_pfcode = statp->pfcode;
198 statp->pfcode |= RES_PRF_HEAD2 | RES_PRF_HEAD1 | RES_PRF_HEADX |
199 RES_PRF_QUES | RES_PRF_ANS |
200 RES_PRF_AUTH | RES_PRF_ADD;
201 INIT_LIST(nsrrs);
202
203 DPRINTF(("get the soa, and see if it has enough glue"));
204 if ((n = get_soa(statp, dname, class, opts, zname, zsize,
205 mname, sizeof mname, &nsrrs)) < 0 ||
206 ((opts & RES_EXHAUSTIVE) == 0 &&
207 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
208 goto done;
209
210 DPRINTF(("get the ns rrset and see if it has enough glue"));
211 if ((n = get_ns(statp, zname, class, opts, &nsrrs)) < 0 ||
212 ((opts & RES_EXHAUSTIVE) == 0 &&
213 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
214 goto done;
215
216 DPRINTF(("get the missing glue and see if it's finally enough"));
217 if ((n = get_glue(statp, class, opts, &nsrrs)) >= 0)
218 n = satisfy(statp, mname, &nsrrs, addrs, naddrs);
219
220 done:
221 DPRINTF(("FINISH n=%d (%s)", n, (n < 0) ? strerror(errno) : "OK"));
222 free_nsrrset(&nsrrs);
223 statp->pfcode = save_pfcode;
224 return (n);
225 }
226
227 /* Private. */
228
229 static int
satisfy(res_state statp,const char * mname,rrset_ns * nsrrsp,union res_sockaddr_union * addrs,int naddrs)230 satisfy(res_state statp, const char *mname, rrset_ns *nsrrsp,
231 union res_sockaddr_union *addrs, int naddrs)
232 {
233 rr_ns *nsrr;
234 int n, x;
235
236 n = 0;
237 nsrr = find_ns(nsrrsp, mname);
238 if (nsrr != NULL) {
239 x = add_addrs(statp, nsrr, addrs, naddrs);
240 addrs += x;
241 naddrs -= x;
242 n += x;
243 }
244 for (nsrr = HEAD(*nsrrsp);
245 nsrr != NULL && naddrs > 0;
246 nsrr = NEXT(nsrr, link))
247 if (ns_samename(nsrr->name, mname) != 1) {
248 x = add_addrs(statp, nsrr, addrs, naddrs);
249 addrs += x;
250 naddrs -= x;
251 n += x;
252 }
253 DPRINTF(("satisfy(%s): %d", mname, n));
254 return (n);
255 }
256
257 static int
add_addrs(res_state statp,rr_ns * nsrr,union res_sockaddr_union * addrs,int naddrs)258 add_addrs(res_state statp, rr_ns *nsrr,
259 union res_sockaddr_union *addrs, int naddrs)
260 {
261 rr_a *arr;
262 int n = 0;
263
264 for (arr = HEAD(nsrr->addrs); arr != NULL; arr = NEXT(arr, link)) {
265 if (naddrs <= 0)
266 return (0);
267 *addrs++ = arr->addr;
268 naddrs--;
269 n++;
270 }
271 DPRINTF(("add_addrs: %d", n));
272 return (n);
273 }
274
275 static int
get_soa(res_state statp,const char * dname,ns_class class,int opts,char * zname,size_t zsize,char * mname,size_t msize,rrset_ns * nsrrsp)276 get_soa(res_state statp, const char *dname, ns_class class, int opts,
277 char *zname, size_t zsize, char *mname, size_t msize,
278 rrset_ns *nsrrsp)
279 {
280 char tname[NS_MAXDNAME];
281 u_char *resp = NULL;
282 int n, i, ancount, nscount;
283 ns_sect sect;
284 ns_msg msg;
285 u_int rcode;
286
287 /*
288 * Find closest enclosing SOA, even if it's for the root zone.
289 */
290
291 /* First canonicalize dname (exactly one unescaped trailing "."). */
292 if (ns_makecanon(dname, tname, sizeof tname) < 0)
293 goto cleanup;
294 dname = tname;
295
296 resp = malloc(NS_MAXMSG);
297 if (resp == NULL)
298 goto cleanup;
299
300 /* Now grovel the subdomains, hunting for an SOA answer or auth. */
301 for (;;) {
302 /* Leading or inter-label '.' are skipped here. */
303 while (*dname == '.')
304 dname++;
305
306 /* Is there an SOA? */
307 n = do_query(statp, dname, class, ns_t_soa, resp, &msg);
308 if (n < 0) {
309 DPRINTF(("get_soa: do_query('%s', %s) failed (%d)",
310 dname, p_class(class), n));
311 goto cleanup;
312 }
313 if (n > 0) {
314 DPRINTF(("get_soa: CNAME or DNAME found"));
315 sect = ns_s_max, n = 0;
316 } else {
317 rcode = ns_msg_getflag(msg, ns_f_rcode);
318 ancount = ns_msg_count(msg, ns_s_an);
319 nscount = ns_msg_count(msg, ns_s_ns);
320 if (ancount > 0 && rcode == ns_r_noerror)
321 sect = ns_s_an, n = ancount;
322 else if (nscount > 0)
323 sect = ns_s_ns, n = nscount;
324 else
325 sect = ns_s_max, n = 0;
326 }
327 for (i = 0; i < n; i++) {
328 const char *t;
329 const u_char *rdata;
330 ns_rr rr;
331
332 if (ns_parserr(&msg, sect, i, &rr) < 0) {
333 DPRINTF(("get_soa: ns_parserr(%s, %d) failed",
334 p_section(sect, ns_o_query), i));
335 goto cleanup;
336 }
337 if (ns_rr_type(rr) == ns_t_cname ||
338 ns_rr_type(rr) == ns_t_dname)
339 break;
340 if (ns_rr_type(rr) != ns_t_soa ||
341 ns_rr_class(rr) != class)
342 continue;
343 t = ns_rr_name(rr);
344 switch (sect) {
345 case ns_s_an:
346 if (ns_samedomain(dname, t) == 0) {
347 DPRINTF(
348 ("get_soa: ns_samedomain('%s', '%s') == 0",
349 dname, t)
350 );
351 errno = EPROTOTYPE;
352 goto cleanup;
353 }
354 break;
355 case ns_s_ns:
356 if (ns_samename(dname, t) == 1 ||
357 ns_samedomain(dname, t) == 0) {
358 DPRINTF(
359 ("get_soa: ns_samename() || !ns_samedomain('%s', '%s')",
360 dname, t)
361 );
362 errno = EPROTOTYPE;
363 goto cleanup;
364 }
365 break;
366 default:
367 abort();
368 }
369 if (strlen(t) + 1 > zsize) {
370 DPRINTF(("get_soa: zname(%lu) too small (%lu)",
371 (unsigned long)zsize,
372 (unsigned long)strlen(t) + 1));
373 errno = EMSGSIZE;
374 goto cleanup;
375 }
376 strcpy(zname, t);
377 rdata = ns_rr_rdata(rr);
378 if (ns_name_uncompress(resp, ns_msg_end(msg), rdata,
379 mname, msize) < 0) {
380 DPRINTF(("get_soa: ns_name_uncompress failed")
381 );
382 goto cleanup;
383 }
384 if (save_ns(statp, &msg, ns_s_ns,
385 zname, class, opts, nsrrsp) < 0) {
386 DPRINTF(("get_soa: save_ns failed"));
387 goto cleanup;
388 }
389 free(resp);
390 return (0);
391 }
392
393 /* If we're out of labels, then not even "." has an SOA! */
394 if (*dname == '\0')
395 break;
396
397 /* Find label-terminating "."; top of loop will skip it. */
398 while (*dname != '.') {
399 if (*dname == '\\')
400 if (*++dname == '\0') {
401 errno = EMSGSIZE;
402 goto cleanup;
403 }
404 dname++;
405 }
406 }
407 DPRINTF(("get_soa: out of labels"));
408 errno = EDESTADDRREQ;
409 cleanup:
410 if (resp != NULL)
411 free(resp);
412 return (-1);
413 }
414
415 static int
get_ns(res_state statp,const char * zname,ns_class class,int opts,rrset_ns * nsrrsp)416 get_ns(res_state statp, const char *zname, ns_class class, int opts,
417 rrset_ns *nsrrsp)
418 {
419 u_char *resp;
420 ns_msg msg;
421 int n;
422
423 resp = malloc(NS_MAXMSG);
424 if (resp == NULL)
425 return (-1);
426
427 /* Go and get the NS RRs for this zone. */
428 n = do_query(statp, zname, class, ns_t_ns, resp, &msg);
429 if (n != 0) {
430 DPRINTF(("get_ns: do_query('%s', %s) failed (%d)",
431 zname, p_class(class), n));
432 free(resp);
433 return (-1);
434 }
435
436 /* Remember the NS RRs and associated A RRs that came back. */
437 if (save_ns(statp, &msg, ns_s_an, zname, class, opts, nsrrsp) < 0) {
438 DPRINTF(("get_ns save_ns('%s', %s) failed",
439 zname, p_class(class)));
440 free(resp);
441 return (-1);
442 }
443
444 free(resp);
445 return (0);
446 }
447
448 static int
get_glue(res_state statp,ns_class class,int opts,rrset_ns * nsrrsp)449 get_glue(res_state statp, ns_class class, int opts, rrset_ns *nsrrsp) {
450 rr_ns *nsrr, *nsrr_n;
451 u_char *resp;
452
453 resp = malloc(NS_MAXMSG);
454 if (resp == NULL)
455 return(-1);
456
457 /* Go and get the A RRs for each empty NS RR on our list. */
458 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = nsrr_n) {
459 ns_msg msg;
460 int n;
461
462 nsrr_n = NEXT(nsrr, link);
463
464 if ((nsrr->flags & RR_NS_HAVE_V4) == 0) {
465 n = do_query(statp, nsrr->name, class, ns_t_a,
466 resp, &msg);
467 if (n < 0) {
468 DPRINTF(
469 ("get_glue: do_query('%s', %s') failed",
470 nsrr->name, p_class(class)));
471 goto cleanup;
472 }
473 if (n > 0) {
474 DPRINTF((
475 "get_glue: do_query('%s', %s') CNAME or DNAME found",
476 nsrr->name, p_class(class)));
477 }
478 if (save_a(statp, &msg, ns_s_an, nsrr->name, class,
479 opts, nsrr) < 0) {
480 DPRINTF(("get_glue: save_r('%s', %s) failed",
481 nsrr->name, p_class(class)));
482 goto cleanup;
483 }
484 }
485
486 if ((nsrr->flags & RR_NS_HAVE_V6) == 0) {
487 n = do_query(statp, nsrr->name, class, ns_t_aaaa,
488 resp, &msg);
489 if (n < 0) {
490 DPRINTF(
491 ("get_glue: do_query('%s', %s') failed",
492 nsrr->name, p_class(class)));
493 goto cleanup;
494 }
495 if (n > 0) {
496 DPRINTF((
497 "get_glue: do_query('%s', %s') CNAME or DNAME found",
498 nsrr->name, p_class(class)));
499 }
500 if (save_a(statp, &msg, ns_s_an, nsrr->name, class,
501 opts, nsrr) < 0) {
502 DPRINTF(("get_glue: save_r('%s', %s) failed",
503 nsrr->name, p_class(class)));
504 goto cleanup;
505 }
506 }
507
508 /* If it's still empty, it's just chaff. */
509 if (EMPTY(nsrr->addrs)) {
510 DPRINTF(("get_glue: removing empty '%s' NS",
511 nsrr->name));
512 free_nsrr(nsrrsp, nsrr);
513 }
514 }
515 free(resp);
516 return (0);
517
518 cleanup:
519 free(resp);
520 return (-1);
521 }
522
523 static int
save_ns(res_state statp,ns_msg * msg,ns_sect sect,const char * owner,ns_class class,int opts,rrset_ns * nsrrsp)524 save_ns(res_state statp, ns_msg *msg, ns_sect sect,
525 const char *owner, ns_class class, int opts,
526 rrset_ns *nsrrsp)
527 {
528 int i;
529
530 for (i = 0; i < ns_msg_count(*msg, sect); i++) {
531 char tname[MAXDNAME];
532 const u_char *rdata;
533 rr_ns *nsrr;
534 ns_rr rr;
535
536 if (ns_parserr(msg, sect, i, &rr) < 0) {
537 DPRINTF(("save_ns: ns_parserr(%s, %d) failed",
538 p_section(sect, ns_o_query), i));
539 return (-1);
540 }
541 if (ns_rr_type(rr) != ns_t_ns ||
542 ns_rr_class(rr) != class ||
543 ns_samename(ns_rr_name(rr), owner) != 1)
544 continue;
545 nsrr = find_ns(nsrrsp, ns_rr_name(rr));
546 if (nsrr == NULL) {
547 nsrr = malloc(sizeof *nsrr);
548 if (nsrr == NULL) {
549 DPRINTF(("save_ns: malloc failed"));
550 return (-1);
551 }
552 rdata = ns_rr_rdata(rr);
553 if (ns_name_uncompress(ns_msg_base(*msg),
554 ns_msg_end(*msg), rdata,
555 tname, sizeof tname) < 0) {
556 DPRINTF(("save_ns: ns_name_uncompress failed")
557 );
558 free(nsrr);
559 return (-1);
560 }
561 nsrr->name = strdup(tname);
562 if (nsrr->name == NULL) {
563 DPRINTF(("save_ns: strdup failed"));
564 free(nsrr);
565 return (-1);
566 }
567 INIT_LINK(nsrr, link);
568 INIT_LIST(nsrr->addrs);
569 nsrr->flags = 0;
570 APPEND(*nsrrsp, nsrr, link);
571 }
572 if (save_a(statp, msg, ns_s_ar,
573 nsrr->name, class, opts, nsrr) < 0) {
574 DPRINTF(("save_ns: save_r('%s', %s) failed",
575 nsrr->name, p_class(class)));
576 return (-1);
577 }
578 }
579 return (0);
580 }
581
582 static int
save_a(res_state statp,ns_msg * msg,ns_sect sect,const char * owner,ns_class class,int opts,rr_ns * nsrr)583 save_a(res_state statp, ns_msg *msg, ns_sect sect,
584 const char *owner, ns_class class, int opts,
585 rr_ns *nsrr)
586 {
587 int i;
588
589 for (i = 0; i < ns_msg_count(*msg, sect); i++) {
590 ns_rr rr;
591 rr_a *arr;
592
593 if (ns_parserr(msg, sect, i, &rr) < 0) {
594 DPRINTF(("save_a: ns_parserr(%s, %d) failed",
595 p_section(sect, ns_o_query), i));
596 return (-1);
597 }
598 if ((ns_rr_type(rr) != ns_t_a &&
599 ns_rr_type(rr) != ns_t_aaaa) ||
600 ns_rr_class(rr) != class ||
601 ns_samename(ns_rr_name(rr), owner) != 1 ||
602 ns_rr_rdlen(rr) != NS_INADDRSZ)
603 continue;
604 if ((opts & RES_IPV6ONLY) != 0 && ns_rr_type(rr) != ns_t_aaaa)
605 continue;
606 if ((opts & RES_IPV4ONLY) != 0 && ns_rr_type(rr) != ns_t_a)
607 continue;
608 arr = malloc(sizeof *arr);
609 if (arr == NULL) {
610 DPRINTF(("save_a: malloc failed"));
611 return (-1);
612 }
613 INIT_LINK(arr, link);
614 memset(&arr->addr, 0, sizeof(arr->addr));
615 switch (ns_rr_type(rr)) {
616 case ns_t_a:
617 arr->addr.sin.sin_family = AF_INET;
618 #ifdef HAVE_SA_LEN
619 arr->addr.sin.sin_len = sizeof(arr->addr.sin);
620 #endif
621 memcpy(&arr->addr.sin.sin_addr, ns_rr_rdata(rr),
622 NS_INADDRSZ);
623 arr->addr.sin.sin_port = htons(NAMESERVER_PORT);
624 nsrr->flags |= RR_NS_HAVE_V4;
625 break;
626 case ns_t_aaaa:
627 arr->addr.sin6.sin6_family = AF_INET6;
628 #ifdef HAVE_SA_LEN
629 arr->addr.sin6.sin6_len = sizeof(arr->addr.sin6);
630 #endif
631 memcpy(&arr->addr.sin6.sin6_addr, ns_rr_rdata(rr), 16);
632 arr->addr.sin6.sin6_port = htons(NAMESERVER_PORT);
633 nsrr->flags |= RR_NS_HAVE_V6;
634 break;
635 default:
636 abort();
637 }
638 APPEND(nsrr->addrs, arr, link);
639 }
640 return (0);
641 }
642
643 static void
free_nsrrset(rrset_ns * nsrrsp)644 free_nsrrset(rrset_ns *nsrrsp) {
645 rr_ns *nsrr;
646
647 while ((nsrr = HEAD(*nsrrsp)) != NULL)
648 free_nsrr(nsrrsp, nsrr);
649 }
650
651 static void
free_nsrr(rrset_ns * nsrrsp,rr_ns * nsrr)652 free_nsrr(rrset_ns *nsrrsp, rr_ns *nsrr) {
653 rr_a *arr;
654 char *tmp;
655
656 while ((arr = HEAD(nsrr->addrs)) != NULL) {
657 UNLINK(nsrr->addrs, arr, link);
658 free(arr);
659 }
660 DE_CONST(nsrr->name, tmp);
661 free(tmp);
662 UNLINK(*nsrrsp, nsrr, link);
663 free(nsrr);
664 }
665
666 static rr_ns *
find_ns(rrset_ns * nsrrsp,const char * dname)667 find_ns(rrset_ns *nsrrsp, const char *dname) {
668 rr_ns *nsrr;
669
670 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = NEXT(nsrr, link))
671 if (ns_samename(nsrr->name, dname) == 1)
672 return (nsrr);
673 return (NULL);
674 }
675
676 static int
do_query(res_state statp,const char * dname,ns_class class,ns_type qtype,u_char * resp,ns_msg * msg)677 do_query(res_state statp, const char *dname, ns_class class, ns_type qtype,
678 u_char *resp, ns_msg *msg)
679 {
680 u_char req[NS_PACKETSZ];
681 int i, n;
682
683 n = res_nmkquery(statp, ns_o_query, dname, class, qtype,
684 NULL, 0, NULL, req, NS_PACKETSZ);
685 if (n < 0) {
686 DPRINTF(("do_query: res_nmkquery failed"));
687 return (-1);
688 }
689 n = res_nsend(statp, req, n, resp, NS_MAXMSG);
690 if (n < 0) {
691 DPRINTF(("do_query: res_nsend failed"));
692 return (-1);
693 }
694 if (n == 0) {
695 DPRINTF(("do_query: res_nsend returned 0"));
696 errno = EMSGSIZE;
697 return (-1);
698 }
699 if (ns_initparse(resp, n, msg) < 0) {
700 DPRINTF(("do_query: ns_initparse failed"));
701 return (-1);
702 }
703 n = 0;
704 for (i = 0; i < ns_msg_count(*msg, ns_s_an); i++) {
705 ns_rr rr;
706
707 if (ns_parserr(msg, ns_s_an, i, &rr) < 0) {
708 DPRINTF(("do_query: ns_parserr failed"));
709 return (-1);
710 }
711 n += (ns_rr_class(rr) == class &&
712 (ns_rr_type(rr) == ns_t_cname ||
713 ns_rr_type(rr) == ns_t_dname));
714 }
715 return (n);
716 }
717
718 static void
res_dprintf(const char * fmt,...)719 res_dprintf(const char *fmt, ...) {
720 va_list ap;
721
722 va_start(ap, fmt);
723 fputs(";; res_findzonecut: ", stderr);
724 vfprintf(stderr, fmt, ap);
725 fputc('\n', stderr);
726 va_end(ap);
727 }
728
729 /*! \file */
730