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