1 | /* |
2 | * Copyright (c) 1988, 1993 |
3 | * The Regents of the University of California. All rights reserved. |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
8 | * 1. Redistributions of source code must retain the above copyright |
9 | * notice, this list of conditions and the following disclaimer. |
10 | * 2. Redistributions in binary form must reproduce the above copyright |
11 | * notice, this list of conditions and the following disclaimer in the |
12 | * documentation and/or other materials provided with the distribution. |
13 | * 4. Neither the name of the University nor the names of its contributors |
14 | * may be used to endorse or promote products derived from this software |
15 | * without specific prior written permission. |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
27 | * SUCH DAMAGE. |
28 | */ |
29 | |
30 | /* |
31 | * Portions Copyright (c) 1993 by Digital Equipment Corporation. |
32 | * |
33 | * Permission to use, copy, modify, and distribute this software for any |
34 | * purpose with or without fee is hereby granted, provided that the above |
35 | * copyright notice and this permission notice appear in all copies, and that |
36 | * the name of Digital Equipment Corporation not be used in advertising or |
37 | * publicity pertaining to distribution of the document or software without |
38 | * specific, written prior permission. |
39 | * |
40 | * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL |
41 | * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES |
42 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT |
43 | * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
44 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
45 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
46 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
47 | * SOFTWARE. |
48 | */ |
49 | |
50 | /* |
51 | * Portions Copyright (c) 1996-1999 by Internet Software Consortium. |
52 | * |
53 | * Permission to use, copy, modify, and distribute this software for any |
54 | * purpose with or without fee is hereby granted, provided that the above |
55 | * copyright notice and this permission notice appear in all copies. |
56 | * |
57 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS |
58 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES |
59 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE |
60 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
61 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
62 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
63 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
64 | * SOFTWARE. |
65 | */ |
66 | |
67 | #if defined(LIBC_SCCS) && !defined(lint) |
68 | static const char sccsid[] = "@(#)res_query.c 8.1 (Berkeley) 6/4/93" ; |
69 | static const char rcsid[] = "$BINDId: res_query.c,v 8.20 2000/02/29 05:39:12 vixie Exp $" ; |
70 | #endif /* LIBC_SCCS and not lint */ |
71 | |
72 | #include <assert.h> |
73 | #include <sys/types.h> |
74 | #include <sys/param.h> |
75 | #include <netinet/in.h> |
76 | #include <arpa/inet.h> |
77 | #include <arpa/nameser.h> |
78 | #include <ctype.h> |
79 | #include <errno.h> |
80 | #include <netdb.h> |
81 | #include <resolv.h> |
82 | #include <stdio.h> |
83 | #include <stdlib.h> |
84 | #include <string.h> |
85 | |
86 | /* Options. Leave them on. */ |
87 | /* #undef DEBUG */ |
88 | |
89 | #if PACKETSZ > 65536 |
90 | #define MAXPACKET PACKETSZ |
91 | #else |
92 | #define MAXPACKET 65536 |
93 | #endif |
94 | |
95 | #define QUERYSIZE (HFIXEDSZ + QFIXEDSZ + MAXCDNAME + 1) |
96 | |
97 | static int |
98 | __libc_res_nquerydomain(res_state statp, const char *name, const char *domain, |
99 | int class, int type, u_char *answer, int anslen, |
100 | u_char **answerp, u_char **answerp2, int *nanswerp2, |
101 | int *resplen2, int *answerp2_malloced); |
102 | |
103 | /* |
104 | * Formulate a normal query, send, and await answer. |
105 | * Returned answer is placed in supplied buffer "answer". |
106 | * Perform preliminary check of answer, returning success only |
107 | * if no error is indicated and the answer count is nonzero. |
108 | * Return the size of the response on success, -1 on error. |
109 | * Error number is left in H_ERRNO. |
110 | * |
111 | * Caller must parse answer and determine whether it answers the question. |
112 | */ |
113 | int |
114 | __libc_res_nquery(res_state statp, |
115 | const char *name, /* domain name */ |
116 | int class, int type, /* class and type of query */ |
117 | u_char *answer, /* buffer to put answer */ |
118 | int anslen, /* size of answer buffer */ |
119 | u_char **answerp, /* if buffer needs to be enlarged */ |
120 | u_char **answerp2, |
121 | int *nanswerp2, |
122 | int *resplen2, |
123 | int *answerp2_malloced) |
124 | { |
125 | HEADER *hp = (HEADER *) answer; |
126 | HEADER *hp2; |
127 | int n, use_malloc = 0; |
128 | u_int oflags = statp->_flags; |
129 | |
130 | size_t bufsize = (type == T_UNSPEC ? 2 : 1) * QUERYSIZE; |
131 | u_char *buf = alloca (bufsize); |
132 | u_char *query1 = buf; |
133 | int nquery1 = -1; |
134 | u_char *query2 = NULL; |
135 | int nquery2 = 0; |
136 | |
137 | again: |
138 | hp->rcode = NOERROR; /* default */ |
139 | |
140 | #ifdef DEBUG |
141 | if (statp->options & RES_DEBUG) |
142 | printf(";; res_query(%s, %d, %d)\n" , name, class, type); |
143 | #endif |
144 | |
145 | if (type == T_UNSPEC) |
146 | { |
147 | n = res_nmkquery(statp, QUERY, name, class, T_A, NULL, 0, NULL, |
148 | query1, bufsize); |
149 | if (n > 0) |
150 | { |
151 | if ((oflags & RES_F_EDNS0ERR) == 0 |
152 | && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) |
153 | { |
154 | n = __res_nopt(statp, n, query1, bufsize, anslen / 2); |
155 | if (n < 0) |
156 | goto unspec_nomem; |
157 | } |
158 | |
159 | nquery1 = n; |
160 | /* Align the buffer. */ |
161 | int npad = ((nquery1 + __alignof__ (HEADER) - 1) |
162 | & ~(__alignof__ (HEADER) - 1)) - nquery1; |
163 | if (n > bufsize - npad) |
164 | { |
165 | n = -1; |
166 | goto unspec_nomem; |
167 | } |
168 | int nused = n + npad; |
169 | query2 = buf + nused; |
170 | n = res_nmkquery(statp, QUERY, name, class, T_AAAA, NULL, 0, |
171 | NULL, query2, bufsize - nused); |
172 | if (n > 0 |
173 | && (oflags & RES_F_EDNS0ERR) == 0 |
174 | && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) |
175 | n = __res_nopt(statp, n, query2, bufsize - nused - n, |
176 | anslen / 2); |
177 | nquery2 = n; |
178 | } |
179 | |
180 | unspec_nomem:; |
181 | } |
182 | else |
183 | { |
184 | n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL, |
185 | query1, bufsize); |
186 | |
187 | if (n > 0 |
188 | && (oflags & RES_F_EDNS0ERR) == 0 |
189 | && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) |
190 | n = __res_nopt(statp, n, query1, bufsize, anslen); |
191 | |
192 | nquery1 = n; |
193 | } |
194 | |
195 | if (__builtin_expect (n <= 0, 0) && !use_malloc) { |
196 | /* Retry just in case res_nmkquery failed because of too |
197 | short buffer. Shouldn't happen. */ |
198 | bufsize = (type == T_UNSPEC ? 2 : 1) * MAXPACKET; |
199 | buf = malloc (bufsize); |
200 | if (buf != NULL) { |
201 | query1 = buf; |
202 | use_malloc = 1; |
203 | goto again; |
204 | } |
205 | } |
206 | if (__glibc_unlikely (n <= 0)) { |
207 | /* If the query choked with EDNS0, retry without EDNS0. */ |
208 | if ((statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0 |
209 | && ((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) { |
210 | statp->_flags |= RES_F_EDNS0ERR; |
211 | #ifdef DEBUG |
212 | if (statp->options & RES_DEBUG) |
213 | printf(";; res_nquery: retry without EDNS0\n" ); |
214 | #endif |
215 | goto again; |
216 | } |
217 | #ifdef DEBUG |
218 | if (statp->options & RES_DEBUG) |
219 | printf(";; res_query: mkquery failed\n" ); |
220 | #endif |
221 | RES_SET_H_ERRNO(statp, NO_RECOVERY); |
222 | if (use_malloc) |
223 | free (buf); |
224 | return (n); |
225 | } |
226 | assert (answerp == NULL || (void *) *answerp == (void *) answer); |
227 | n = __libc_res_nsend(statp, query1, nquery1, query2, nquery2, answer, |
228 | anslen, answerp, answerp2, nanswerp2, resplen2, |
229 | answerp2_malloced); |
230 | if (use_malloc) |
231 | free (buf); |
232 | if (n < 0) { |
233 | #ifdef DEBUG |
234 | if (statp->options & RES_DEBUG) |
235 | printf(";; res_query: send error\n" ); |
236 | #endif |
237 | RES_SET_H_ERRNO(statp, TRY_AGAIN); |
238 | return (n); |
239 | } |
240 | |
241 | if (answerp != NULL) |
242 | /* __libc_res_nsend might have reallocated the buffer. */ |
243 | hp = (HEADER *) *answerp; |
244 | |
245 | /* We simplify the following tests by assigning HP to HP2 or |
246 | vice versa. It is easy to verify that this is the same as |
247 | ignoring all tests of HP or HP2. */ |
248 | if (answerp2 == NULL || *resplen2 < (int) sizeof (HEADER)) |
249 | { |
250 | hp2 = hp; |
251 | } |
252 | else |
253 | { |
254 | hp2 = (HEADER *) *answerp2; |
255 | if (n < (int) sizeof (HEADER)) |
256 | { |
257 | hp = hp2; |
258 | } |
259 | } |
260 | |
261 | /* Make sure both hp and hp2 are defined */ |
262 | assert((hp != NULL) && (hp2 != NULL)); |
263 | |
264 | if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0) |
265 | && (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) { |
266 | #ifdef DEBUG |
267 | if (statp->options & RES_DEBUG) { |
268 | printf(";; rcode = %d, ancount=%d\n" , hp->rcode, |
269 | ntohs(hp->ancount)); |
270 | if (hp != hp2) |
271 | printf(";; rcode2 = %d, ancount2=%d\n" , hp2->rcode, |
272 | ntohs(hp2->ancount)); |
273 | } |
274 | #endif |
275 | switch (hp->rcode == NOERROR ? hp2->rcode : hp->rcode) { |
276 | case NXDOMAIN: |
277 | if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0) |
278 | || (hp2->rcode == NOERROR |
279 | && ntohs (hp2->ancount) != 0)) |
280 | goto success; |
281 | RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); |
282 | break; |
283 | case SERVFAIL: |
284 | RES_SET_H_ERRNO(statp, TRY_AGAIN); |
285 | break; |
286 | case NOERROR: |
287 | if (ntohs (hp->ancount) != 0 |
288 | || ntohs (hp2->ancount) != 0) |
289 | goto success; |
290 | RES_SET_H_ERRNO(statp, NO_DATA); |
291 | break; |
292 | case FORMERR: |
293 | case NOTIMP: |
294 | /* Servers must not reply to AAAA queries with |
295 | NOTIMP etc but some of them do. */ |
296 | if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0) |
297 | || (hp2->rcode == NOERROR |
298 | && ntohs (hp2->ancount) != 0)) |
299 | goto success; |
300 | /* FALLTHROUGH */ |
301 | case REFUSED: |
302 | default: |
303 | RES_SET_H_ERRNO(statp, NO_RECOVERY); |
304 | break; |
305 | } |
306 | return (-1); |
307 | } |
308 | success: |
309 | return (n); |
310 | } |
311 | libresolv_hidden_def (__libc_res_nquery) |
312 | |
313 | int |
314 | res_nquery(res_state statp, |
315 | const char *name, /* domain name */ |
316 | int class, int type, /* class and type of query */ |
317 | u_char *answer, /* buffer to put answer */ |
318 | int anslen) /* size of answer buffer */ |
319 | { |
320 | return __libc_res_nquery(statp, name, class, type, answer, anslen, |
321 | NULL, NULL, NULL, NULL, NULL); |
322 | } |
323 | libresolv_hidden_def (res_nquery) |
324 | |
325 | /* |
326 | * Formulate a normal query, send, and retrieve answer in supplied buffer. |
327 | * Return the size of the response on success, -1 on error. |
328 | * If enabled, implement search rules until answer or unrecoverable failure |
329 | * is detected. Error code, if any, is left in H_ERRNO. |
330 | */ |
331 | int |
332 | __libc_res_nsearch(res_state statp, |
333 | const char *name, /* domain name */ |
334 | int class, int type, /* class and type of query */ |
335 | u_char *answer, /* buffer to put answer */ |
336 | int anslen, /* size of answer */ |
337 | u_char **answerp, |
338 | u_char **answerp2, |
339 | int *nanswerp2, |
340 | int *resplen2, |
341 | int *answerp2_malloced) |
342 | { |
343 | const char *cp, * const *domain; |
344 | HEADER *hp = (HEADER *) answer; |
345 | char tmp[NS_MAXDNAME]; |
346 | u_int dots; |
347 | int trailing_dot, ret, saved_herrno; |
348 | int got_nodata = 0, got_servfail = 0, root_on_list = 0; |
349 | int tried_as_is = 0; |
350 | int searched = 0; |
351 | |
352 | __set_errno (0); |
353 | RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); /* True if we never query. */ |
354 | |
355 | dots = 0; |
356 | for (cp = name; *cp != '\0'; cp++) |
357 | dots += (*cp == '.'); |
358 | trailing_dot = 0; |
359 | if (cp > name && *--cp == '.') |
360 | trailing_dot++; |
361 | |
362 | /* If there aren't any dots, it could be a user-level alias. */ |
363 | if (!dots && (cp = res_hostalias(statp, name, tmp, sizeof tmp))!= NULL) |
364 | return (__libc_res_nquery(statp, cp, class, type, answer, |
365 | anslen, answerp, answerp2, |
366 | nanswerp2, resplen2, answerp2_malloced)); |
367 | |
368 | #ifdef DEBUG |
369 | if (statp->options & RES_DEBUG) |
370 | printf("dots=%d, statp->ndots=%d, trailing_dot=%d, name=%s\n" , |
371 | (int)dots,(int)statp->ndots,(int)trailing_dot,name); |
372 | #endif |
373 | |
374 | /* |
375 | * If there are enough dots in the name, let's just give it a |
376 | * try 'as is'. The threshold can be set with the "ndots" option. |
377 | * Also, query 'as is', if there is a trailing dot in the name. |
378 | */ |
379 | saved_herrno = -1; |
380 | if (dots >= statp->ndots || trailing_dot) { |
381 | ret = __libc_res_nquerydomain(statp, name, NULL, class, type, |
382 | answer, anslen, answerp, |
383 | answerp2, nanswerp2, resplen2, |
384 | answerp2_malloced); |
385 | if (ret > 0 || trailing_dot |
386 | /* If the second response is valid then we use that. */ |
387 | || (ret == 0 && resplen2 != NULL && *resplen2 > 0)) |
388 | return (ret); |
389 | saved_herrno = h_errno; |
390 | tried_as_is++; |
391 | if (answerp && *answerp != answer) { |
392 | answer = *answerp; |
393 | anslen = MAXPACKET; |
394 | } |
395 | if (answerp2 && *answerp2_malloced) |
396 | { |
397 | free (*answerp2); |
398 | *answerp2 = NULL; |
399 | *nanswerp2 = 0; |
400 | *answerp2_malloced = 0; |
401 | } |
402 | } |
403 | |
404 | /* |
405 | * We do at least one level of search if |
406 | * - there is no dot and RES_DEFNAME is set, or |
407 | * - there is at least one dot, there is no trailing dot, |
408 | * and RES_DNSRCH is set. |
409 | */ |
410 | if ((!dots && (statp->options & RES_DEFNAMES) != 0) || |
411 | (dots && !trailing_dot && (statp->options & RES_DNSRCH) != 0)) { |
412 | int done = 0; |
413 | |
414 | for (domain = (const char * const *)statp->dnsrch; |
415 | *domain && !done; |
416 | domain++) { |
417 | const char *dname = domain[0]; |
418 | searched = 1; |
419 | |
420 | /* __libc_res_nquerydoman concatenates name |
421 | with dname with a "." in between. If we |
422 | pass it in dname the "." we got from the |
423 | configured default search path, we'll end |
424 | up with "name..", which won't resolve. |
425 | OTOH, passing it "" will result in "name.", |
426 | which has the intended effect for both |
427 | possible representations of the root |
428 | domain. */ |
429 | if (dname[0] == '.') |
430 | dname++; |
431 | if (dname[0] == '\0') |
432 | root_on_list++; |
433 | |
434 | ret = __libc_res_nquerydomain(statp, name, dname, |
435 | class, type, |
436 | answer, anslen, answerp, |
437 | answerp2, nanswerp2, |
438 | resplen2, answerp2_malloced); |
439 | if (ret > 0 || (ret == 0 && resplen2 != NULL |
440 | && *resplen2 > 0)) |
441 | return (ret); |
442 | |
443 | if (answerp && *answerp != answer) { |
444 | answer = *answerp; |
445 | anslen = MAXPACKET; |
446 | } |
447 | if (answerp2 && *answerp2_malloced) |
448 | { |
449 | free (*answerp2); |
450 | *answerp2 = NULL; |
451 | *nanswerp2 = 0; |
452 | *answerp2_malloced = 0; |
453 | } |
454 | |
455 | /* |
456 | * If no server present, give up. |
457 | * If name isn't found in this domain, |
458 | * keep trying higher domains in the search list |
459 | * (if that's enabled). |
460 | * On a NO_DATA error, keep trying, otherwise |
461 | * a wildcard entry of another type could keep us |
462 | * from finding this entry higher in the domain. |
463 | * If we get some other error (negative answer or |
464 | * server failure), then stop searching up, |
465 | * but try the input name below in case it's |
466 | * fully-qualified. |
467 | */ |
468 | if (errno == ECONNREFUSED) { |
469 | RES_SET_H_ERRNO(statp, TRY_AGAIN); |
470 | return (-1); |
471 | } |
472 | |
473 | switch (statp->res_h_errno) { |
474 | case NO_DATA: |
475 | got_nodata++; |
476 | /* FALLTHROUGH */ |
477 | case HOST_NOT_FOUND: |
478 | /* keep trying */ |
479 | break; |
480 | case TRY_AGAIN: |
481 | if (hp->rcode == SERVFAIL) { |
482 | /* try next search element, if any */ |
483 | got_servfail++; |
484 | break; |
485 | } |
486 | /* FALLTHROUGH */ |
487 | default: |
488 | /* anything else implies that we're done */ |
489 | done++; |
490 | } |
491 | |
492 | /* if we got here for some reason other than DNSRCH, |
493 | * we only wanted one iteration of the loop, so stop. |
494 | */ |
495 | if ((statp->options & RES_DNSRCH) == 0) |
496 | done++; |
497 | } |
498 | } |
499 | |
500 | /* |
501 | * If the query has not already been tried as is then try it |
502 | * unless RES_NOTLDQUERY is set and there were no dots. |
503 | */ |
504 | if ((dots || !searched || (statp->options & RES_NOTLDQUERY) == 0) |
505 | && !(tried_as_is || root_on_list)) { |
506 | ret = __libc_res_nquerydomain(statp, name, NULL, class, type, |
507 | answer, anslen, answerp, |
508 | answerp2, nanswerp2, resplen2, |
509 | answerp2_malloced); |
510 | if (ret > 0 || (ret == 0 && resplen2 != NULL |
511 | && *resplen2 > 0)) |
512 | return (ret); |
513 | } |
514 | |
515 | /* if we got here, we didn't satisfy the search. |
516 | * if we did an initial full query, return that query's H_ERRNO |
517 | * (note that we wouldn't be here if that query had succeeded). |
518 | * else if we ever got a nodata, send that back as the reason. |
519 | * else send back meaningless H_ERRNO, that being the one from |
520 | * the last DNSRCH we did. |
521 | */ |
522 | if (answerp2 && *answerp2_malloced) |
523 | { |
524 | free (*answerp2); |
525 | *answerp2 = NULL; |
526 | *nanswerp2 = 0; |
527 | *answerp2_malloced = 0; |
528 | } |
529 | if (saved_herrno != -1) |
530 | RES_SET_H_ERRNO(statp, saved_herrno); |
531 | else if (got_nodata) |
532 | RES_SET_H_ERRNO(statp, NO_DATA); |
533 | else if (got_servfail) |
534 | RES_SET_H_ERRNO(statp, TRY_AGAIN); |
535 | return (-1); |
536 | } |
537 | libresolv_hidden_def (__libc_res_nsearch) |
538 | |
539 | int |
540 | res_nsearch(res_state statp, |
541 | const char *name, /* domain name */ |
542 | int class, int type, /* class and type of query */ |
543 | u_char *answer, /* buffer to put answer */ |
544 | int anslen) /* size of answer */ |
545 | { |
546 | return __libc_res_nsearch(statp, name, class, type, answer, |
547 | anslen, NULL, NULL, NULL, NULL, NULL); |
548 | } |
549 | libresolv_hidden_def (res_nsearch) |
550 | |
551 | /* |
552 | * Perform a call on res_query on the concatenation of name and domain. |
553 | */ |
554 | static int |
555 | __libc_res_nquerydomain(res_state statp, |
556 | const char *name, |
557 | const char *domain, |
558 | int class, int type, /* class and type of query */ |
559 | u_char *answer, /* buffer to put answer */ |
560 | int anslen, /* size of answer */ |
561 | u_char **answerp, |
562 | u_char **answerp2, |
563 | int *nanswerp2, |
564 | int *resplen2, |
565 | int *answerp2_malloced) |
566 | { |
567 | char nbuf[MAXDNAME]; |
568 | const char *longname = nbuf; |
569 | size_t n, d; |
570 | |
571 | #ifdef DEBUG |
572 | if (statp->options & RES_DEBUG) |
573 | printf(";; res_nquerydomain(%s, %s, %d, %d)\n" , |
574 | name, domain?domain:"<Nil>" , class, type); |
575 | #endif |
576 | if (domain == NULL) { |
577 | n = strlen(name); |
578 | |
579 | /* Decrement N prior to checking it against MAXDNAME |
580 | so that we detect a wrap to SIZE_MAX and return |
581 | a reasonable error. */ |
582 | n--; |
583 | if (n >= MAXDNAME - 1) { |
584 | RES_SET_H_ERRNO(statp, NO_RECOVERY); |
585 | return (-1); |
586 | } |
587 | longname = name; |
588 | } else { |
589 | n = strlen(name); |
590 | d = strlen(domain); |
591 | if (n + d + 1 >= MAXDNAME) { |
592 | RES_SET_H_ERRNO(statp, NO_RECOVERY); |
593 | return (-1); |
594 | } |
595 | sprintf(nbuf, "%s.%s" , name, domain); |
596 | } |
597 | return (__libc_res_nquery(statp, longname, class, type, answer, |
598 | anslen, answerp, answerp2, nanswerp2, |
599 | resplen2, answerp2_malloced)); |
600 | } |
601 | |
602 | int |
603 | res_nquerydomain(res_state statp, |
604 | const char *name, |
605 | const char *domain, |
606 | int class, int type, /* class and type of query */ |
607 | u_char *answer, /* buffer to put answer */ |
608 | int anslen) /* size of answer */ |
609 | { |
610 | return __libc_res_nquerydomain(statp, name, domain, class, type, |
611 | answer, anslen, NULL, NULL, NULL, NULL, |
612 | NULL); |
613 | } |
614 | libresolv_hidden_def (res_nquerydomain) |
615 | |
616 | const char * |
617 | res_hostalias(const res_state statp, const char *name, char *dst, size_t siz) { |
618 | char *file, *cp1, *cp2; |
619 | char buf[BUFSIZ]; |
620 | FILE *fp; |
621 | |
622 | if (statp->options & RES_NOALIASES) |
623 | return (NULL); |
624 | file = getenv("HOSTALIASES" ); |
625 | if (file == NULL || (fp = fopen(file, "rce" )) == NULL) |
626 | return (NULL); |
627 | setbuf(fp, NULL); |
628 | buf[sizeof(buf) - 1] = '\0'; |
629 | while (fgets(buf, sizeof(buf), fp)) { |
630 | for (cp1 = buf; *cp1 && !isspace(*cp1); ++cp1) |
631 | ; |
632 | if (!*cp1) |
633 | break; |
634 | *cp1 = '\0'; |
635 | if (ns_samename(buf, name) == 1) { |
636 | while (isspace(*++cp1)) |
637 | ; |
638 | if (!*cp1) |
639 | break; |
640 | for (cp2 = cp1 + 1; *cp2 && !isspace(*cp2); ++cp2) |
641 | ; |
642 | *cp2 = '\0'; |
643 | strncpy(dst, cp1, siz - 1); |
644 | dst[siz - 1] = '\0'; |
645 | fclose(fp); |
646 | return (dst); |
647 | } |
648 | } |
649 | fclose(fp); |
650 | return (NULL); |
651 | } |
652 | libresolv_hidden_def (res_hostalias) |
653 | |