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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 | #include <assert.h> | |
68 | #include <sys/types.h> | |
69 | #include <sys/param.h> | |
70 | #include <netinet/in.h> | |
71 | #include <arpa/inet.h> | |
72 | #include <arpa/nameser.h> | |
73 | #include <ctype.h> | |
74 | #include <errno.h> | |
75 | #include <netdb.h> | |
76 | #include <resolv.h> | |
77 | #include <resolv/resolv-internal.h> | |
78 | #include <resolv/resolv_context.h> | |
79 | #include <stdio.h> | |
80 | #include <stdlib.h> | |
81 | #include <string.h> | |
82 | #include <shlib-compat.h> | |
83 | ||
84 | #if PACKETSZ > 65536 | |
85 | #define MAXPACKET PACKETSZ | |
86 | #else | |
87 | #define MAXPACKET 65536 | |
88 | #endif | |
89 | ||
90 | #define QUERYSIZE (HFIXEDSZ + QFIXEDSZ + MAXCDNAME + 1) | |
91 | ||
92 | static int | |
93 | __res_context_querydomain (struct resolv_context *, | |
94 | const char *name, const char *domain, | |
95 | int class, int type, unsigned char *answer, int anslen, | |
96 | unsigned char **answerp, unsigned char **answerp2, int *nanswerp2, | |
97 | int *resplen2, int *answerp2_malloced); | |
98 | ||
99 | /* Formulate a normal query, send, and await answer. Returned answer | |
100 | is placed in supplied buffer ANSWER. Perform preliminary check of | |
101 | answer, returning success only if no error is indicated and the | |
102 | answer count is nonzero. Return the size of the response on | |
103 | success, -1 on error. Error number is left in h_errno. | |
104 | ||
105 | Caller must parse answer and determine whether it answers the | |
106 | question. */ | |
107 | int | |
108 | __res_context_query (struct resolv_context *ctx, const char *name, | |
109 | int class, int type, | |
110 | unsigned char *answer, int anslen, | |
111 | unsigned char **answerp, unsigned char **answerp2, | |
112 | int *nanswerp2, int *resplen2, int *answerp2_malloced) | |
113 | { | |
114 | struct __res_state *statp = ctx->resp; | |
115 | HEADER *hp = (HEADER *) answer; | |
116 | HEADER *hp2; | |
117 | int n, use_malloc = 0; | |
118 | ||
119 | size_t bufsize = (type == T_QUERY_A_AND_AAAA ? 2 : 1) * QUERYSIZE; | |
120 | u_char *buf = alloca (bufsize); | |
121 | u_char *query1 = buf; | |
122 | int nquery1 = -1; | |
123 | u_char *query2 = NULL; | |
124 | int nquery2 = 0; | |
125 | ||
126 | again: | |
127 | hp->rcode = NOERROR; /* default */ | |
128 | ||
129 | if (type == T_QUERY_A_AND_AAAA) | |
130 | { | |
131 | n = __res_context_mkquery (ctx, QUERY, name, class, T_A, NULL, | |
132 | query1, bufsize); | |
133 | if (n > 0) | |
134 | { | |
135 | if ((statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) | |
136 | { | |
137 | /* Use RESOLV_EDNS_BUFFER_SIZE because the receive | |
138 | buffer can be reallocated. */ | |
139 | n = __res_nopt (ctx, n, query1, bufsize, | |
140 | RESOLV_EDNS_BUFFER_SIZE); | |
141 | if (n < 0) | |
142 | goto unspec_nomem; | |
143 | } | |
144 | ||
145 | nquery1 = n; | |
146 | /* Align the buffer. */ | |
147 | int npad = ((nquery1 + __alignof__ (HEADER) - 1) | |
148 | & ~(__alignof__ (HEADER) - 1)) - nquery1; | |
149 | if (n > bufsize - npad) | |
150 | { | |
151 | n = -1; | |
152 | goto unspec_nomem; | |
153 | } | |
154 | int nused = n + npad; | |
155 | query2 = buf + nused; | |
156 | n = __res_context_mkquery (ctx, QUERY, name, class, T_AAAA, | |
157 | NULL, query2, bufsize - nused); | |
158 | if (n > 0 | |
159 | && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) | |
160 | /* Use RESOLV_EDNS_BUFFER_SIZE because the receive | |
161 | buffer can be reallocated. */ | |
162 | n = __res_nopt (ctx, n, query2, bufsize, | |
163 | RESOLV_EDNS_BUFFER_SIZE); | |
164 | nquery2 = n; | |
165 | } | |
166 | ||
167 | unspec_nomem:; | |
168 | } | |
169 | else | |
170 | { | |
171 | n = __res_context_mkquery (ctx, QUERY, name, class, type, NULL, | |
172 | query1, bufsize); | |
173 | ||
174 | if (n > 0 | |
175 | && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) | |
176 | { | |
177 | /* Use RESOLV_EDNS_BUFFER_SIZE if the receive buffer | |
178 | can be reallocated. */ | |
179 | size_t advertise; | |
180 | if (answerp == NULL) | |
181 | advertise = anslen; | |
182 | else | |
183 | advertise = RESOLV_EDNS_BUFFER_SIZE; | |
184 | n = __res_nopt (ctx, n, query1, bufsize, advertise); | |
185 | } | |
186 | ||
187 | nquery1 = n; | |
188 | } | |
189 | ||
190 | if (__glibc_unlikely (n <= 0) && !use_malloc) { | |
191 | /* Retry just in case res_nmkquery failed because of too | |
192 | short buffer. Shouldn't happen. */ | |
193 | bufsize = (type == T_QUERY_A_AND_AAAA ? 2 : 1) * MAXPACKET; | |
194 | buf = malloc (bufsize); | |
195 | if (buf != NULL) { | |
196 | query1 = buf; | |
197 | use_malloc = 1; | |
198 | goto again; | |
199 | } | |
200 | } | |
201 | if (__glibc_unlikely (n <= 0)) { | |
202 | RES_SET_H_ERRNO(statp, NO_RECOVERY); | |
203 | if (use_malloc) | |
204 | free (buf); | |
205 | return (n); | |
206 | } | |
207 | assert (answerp == NULL || (void *) *answerp == (void *) answer); | |
208 | n = __res_context_send (ctx, query1, nquery1, query2, nquery2, answer, | |
209 | anslen, answerp, answerp2, nanswerp2, resplen2, | |
210 | answerp2_malloced); | |
211 | if (use_malloc) | |
212 | free (buf); | |
213 | if (n < 0) { | |
214 | RES_SET_H_ERRNO(statp, TRY_AGAIN); | |
215 | return (n); | |
216 | } | |
217 | ||
218 | if (answerp != NULL) | |
219 | /* __res_context_send might have reallocated the buffer. */ | |
220 | hp = (HEADER *) *answerp; | |
221 | ||
222 | /* We simplify the following tests by assigning HP to HP2 or | |
223 | vice versa. It is easy to verify that this is the same as | |
224 | ignoring all tests of HP or HP2. */ | |
225 | if (answerp2 == NULL || *resplen2 < (int) sizeof (HEADER)) | |
226 | { | |
227 | hp2 = hp; | |
228 | } | |
229 | else | |
230 | { | |
231 | hp2 = (HEADER *) *answerp2; | |
232 | if (n < (int) sizeof (HEADER)) | |
233 | { | |
234 | hp = hp2; | |
235 | } | |
236 | } | |
237 | ||
238 | /* Make sure both hp and hp2 are defined */ | |
239 | assert((hp != NULL) && (hp2 != NULL)); | |
240 | ||
241 | if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0) | |
242 | && (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) { | |
243 | switch (hp->rcode == NOERROR ? hp2->rcode : hp->rcode) { | |
244 | case NXDOMAIN: | |
245 | if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0) | |
246 | || (hp2->rcode == NOERROR | |
247 | && ntohs (hp2->ancount) != 0)) | |
248 | goto success; | |
249 | RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); | |
250 | break; | |
251 | case SERVFAIL: | |
252 | RES_SET_H_ERRNO(statp, TRY_AGAIN); | |
253 | break; | |
254 | case NOERROR: | |
255 | if (ntohs (hp->ancount) != 0 | |
256 | || ntohs (hp2->ancount) != 0) | |
257 | goto success; | |
258 | RES_SET_H_ERRNO(statp, NO_DATA); | |
259 | break; | |
260 | case FORMERR: | |
261 | case NOTIMP: | |
262 | /* Servers must not reply to AAAA queries with | |
263 | NOTIMP etc but some of them do. */ | |
264 | if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0) | |
265 | || (hp2->rcode == NOERROR | |
266 | && ntohs (hp2->ancount) != 0)) | |
267 | goto success; | |
268 | /* FALLTHROUGH */ | |
269 | case REFUSED: | |
270 | default: | |
271 | RES_SET_H_ERRNO(statp, NO_RECOVERY); | |
272 | break; | |
273 | } | |
274 | return (-1); | |
275 | } | |
276 | success: | |
277 | return (n); | |
278 | } | |
279 | libresolv_hidden_def (__res_context_query) | |
280 | ||
281 | /* Common part of res_nquery and res_query. */ | |
282 | static int | |
283 | context_query_common (struct resolv_context *ctx, | |
284 | const char *name, int class, int type, | |
285 | unsigned char *answer, int anslen) | |
286 | { | |
287 | if (ctx == NULL) | |
288 | { | |
289 | RES_SET_H_ERRNO (&_res, NETDB_INTERNAL); | |
290 | return -1; | |
291 | } | |
292 | int result = __res_context_query (ctx, name, class, type, answer, anslen, | |
293 | NULL, NULL, NULL, NULL, NULL); | |
294 | __resolv_context_put (ctx); | |
295 | return result; | |
296 | } | |
297 | ||
298 | int | |
299 | res_nquery(res_state statp, | |
300 | const char *name, /* domain name */ | |
301 | int class, int type, /* class and type of query */ | |
302 | u_char *answer, /* buffer to put answer */ | |
303 | int anslen) /* size of answer buffer */ | |
304 | { | |
305 | return context_query_common | |
306 | (__resolv_context_get_override (statp), name, class, type, answer, anslen); | |
307 | } | |
308 | ||
309 | int | |
310 | res_query (const char *name, int class, int type, | |
311 | unsigned char *answer, int anslen) | |
312 | { | |
313 | return context_query_common | |
314 | (__resolv_context_get (), name, class, type, answer, anslen); | |
315 | } | |
316 | ||
317 | /* Formulate a normal query, send, and retrieve answer in supplied | |
318 | buffer. Return the size of the response on success, -1 on error. | |
319 | If enabled, implement search rules until answer or unrecoverable | |
320 | failure is detected. Error code, if any, is left in h_errno. */ | |
321 | int | |
322 | __res_context_search (struct resolv_context *ctx, | |
323 | const char *name, int class, int type, | |
324 | unsigned char *answer, int anslen, | |
325 | unsigned char **answerp, unsigned char **answerp2, | |
326 | int *nanswerp2, int *resplen2, int *answerp2_malloced) | |
327 | { | |
328 | struct __res_state *statp = ctx->resp; | |
329 | const char *cp; | |
330 | HEADER *hp = (HEADER *) answer; | |
331 | char tmp[NS_MAXDNAME]; | |
332 | u_int dots; | |
333 | int trailing_dot, ret, saved_herrno; | |
334 | int got_nodata = 0, got_servfail = 0, root_on_list = 0; | |
335 | int tried_as_is = 0; | |
336 | int searched = 0; | |
337 | ||
338 | __set_errno (0); | |
339 | RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); /* True if we never query. */ | |
340 | ||
341 | dots = 0; | |
342 | for (cp = name; *cp != '\0'; cp++) | |
343 | dots += (*cp == '.'); | |
344 | trailing_dot = 0; | |
345 | if (cp > name && *--cp == '.') | |
346 | trailing_dot++; | |
347 | ||
348 | /* If there aren't any dots, it could be a user-level alias. */ | |
349 | if (!dots && (cp = __res_context_hostalias | |
350 | (ctx, name, tmp, sizeof tmp))!= NULL) | |
351 | return __res_context_query (ctx, cp, class, type, answer, | |
352 | anslen, answerp, answerp2, | |
353 | nanswerp2, resplen2, answerp2_malloced); | |
354 | ||
355 | /* | |
356 | * If there are enough dots in the name, let's just give it a | |
357 | * try 'as is'. The threshold can be set with the "ndots" option. | |
358 | * Also, query 'as is', if there is a trailing dot in the name. | |
359 | */ | |
360 | saved_herrno = -1; | |
361 | if (dots >= statp->ndots || trailing_dot) { | |
362 | ret = __res_context_querydomain (ctx, name, NULL, class, type, | |
363 | answer, anslen, answerp, | |
364 | answerp2, nanswerp2, resplen2, | |
365 | answerp2_malloced); | |
366 | if (ret > 0 || trailing_dot | |
367 | /* If the second response is valid then we use that. */ | |
368 | || (ret == 0 && resplen2 != NULL && *resplen2 > 0)) | |
369 | return (ret); | |
370 | saved_herrno = h_errno; | |
371 | tried_as_is++; | |
372 | if (answerp && *answerp != answer) { | |
373 | answer = *answerp; | |
374 | anslen = MAXPACKET; | |
375 | } | |
376 | if (answerp2 && *answerp2_malloced) | |
377 | { | |
378 | free (*answerp2); | |
379 | *answerp2 = NULL; | |
380 | *nanswerp2 = 0; | |
381 | *answerp2_malloced = 0; | |
382 | } | |
383 | } | |
384 | ||
385 | /* | |
386 | * We do at least one level of search if | |
387 | * - there is no dot and RES_DEFNAME is set, or | |
388 | * - there is at least one dot, there is no trailing dot, | |
389 | * and RES_DNSRCH is set. | |
390 | */ | |
391 | if ((!dots && (statp->options & RES_DEFNAMES) != 0) || | |
392 | (dots && !trailing_dot && (statp->options & RES_DNSRCH) != 0)) { | |
393 | int done = 0; | |
394 | ||
395 | for (size_t domain_index = 0; !done; ++domain_index) { | |
396 | const char *dname = __resolv_context_search_list | |
397 | (ctx, domain_index); | |
398 | if (dname == NULL) | |
399 | break; | |
400 | searched = 1; | |
401 | ||
402 | /* __res_context_querydoman concatenates name | |
403 | with dname with a "." in between. If we | |
404 | pass it in dname the "." we got from the | |
405 | configured default search path, we'll end | |
406 | up with "name..", which won't resolve. | |
407 | OTOH, passing it "" will result in "name.", | |
408 | which has the intended effect for both | |
409 | possible representations of the root | |
410 | domain. */ | |
411 | if (dname[0] == '.') | |
412 | dname++; | |
413 | if (dname[0] == '\0') | |
414 | root_on_list++; | |
415 | ||
416 | ret = __res_context_querydomain | |
417 | (ctx, name, dname, class, type, | |
418 | answer, anslen, answerp, answerp2, nanswerp2, | |
419 | resplen2, answerp2_malloced); | |
420 | if (ret > 0 || (ret == 0 && resplen2 != NULL | |
421 | && *resplen2 > 0)) | |
422 | return (ret); | |
423 | ||
424 | if (answerp && *answerp != answer) { | |
425 | answer = *answerp; | |
426 | anslen = MAXPACKET; | |
427 | } | |
428 | if (answerp2 && *answerp2_malloced) | |
429 | { | |
430 | free (*answerp2); | |
431 | *answerp2 = NULL; | |
432 | *nanswerp2 = 0; | |
433 | *answerp2_malloced = 0; | |
434 | } | |
435 | ||
436 | /* | |
437 | * If no server present, give up. | |
438 | * If name isn't found in this domain, | |
439 | * keep trying higher domains in the search list | |
440 | * (if that's enabled). | |
441 | * On a NO_DATA error, keep trying, otherwise | |
442 | * a wildcard entry of another type could keep us | |
443 | * from finding this entry higher in the domain. | |
444 | * If we get some other error (negative answer or | |
445 | * server failure), then stop searching up, | |
446 | * but try the input name below in case it's | |
447 | * fully-qualified. | |
448 | */ | |
449 | if (errno == ECONNREFUSED) { | |
450 | RES_SET_H_ERRNO(statp, TRY_AGAIN); | |
451 | return (-1); | |
452 | } | |
453 | ||
454 | switch (statp->res_h_errno) { | |
455 | case NO_DATA: | |
456 | got_nodata++; | |
457 | /* FALLTHROUGH */ | |
458 | case HOST_NOT_FOUND: | |
459 | /* keep trying */ | |
460 | break; | |
461 | case TRY_AGAIN: | |
462 | if (hp->rcode == SERVFAIL) { | |
463 | /* try next search element, if any */ | |
464 | got_servfail++; | |
465 | break; | |
466 | } | |
467 | /* FALLTHROUGH */ | |
468 | default: | |
469 | /* anything else implies that we're done */ | |
470 | done++; | |
471 | } | |
472 | ||
473 | /* if we got here for some reason other than DNSRCH, | |
474 | * we only wanted one iteration of the loop, so stop. | |
475 | */ | |
476 | if ((statp->options & RES_DNSRCH) == 0) | |
477 | done++; | |
478 | } | |
479 | } | |
480 | ||
481 | /* | |
482 | * If the query has not already been tried as is then try it | |
483 | * unless RES_NOTLDQUERY is set and there were no dots. | |
484 | */ | |
485 | if ((dots || !searched || (statp->options & RES_NOTLDQUERY) == 0) | |
486 | && !(tried_as_is || root_on_list)) { | |
487 | ret = __res_context_querydomain | |
488 | (ctx, name, NULL, class, type, | |
489 | answer, anslen, answerp, answerp2, nanswerp2, | |
490 | resplen2, answerp2_malloced); | |
491 | if (ret > 0 || (ret == 0 && resplen2 != NULL | |
492 | && *resplen2 > 0)) | |
493 | return (ret); | |
494 | } | |
495 | ||
496 | /* if we got here, we didn't satisfy the search. | |
497 | * if we did an initial full query, return that query's H_ERRNO | |
498 | * (note that we wouldn't be here if that query had succeeded). | |
499 | * else if we ever got a nodata, send that back as the reason. | |
500 | * else send back meaningless H_ERRNO, that being the one from | |
501 | * the last DNSRCH we did. | |
502 | */ | |
503 | if (answerp2 && *answerp2_malloced) | |
504 | { | |
505 | free (*answerp2); | |
506 | *answerp2 = NULL; | |
507 | *nanswerp2 = 0; | |
508 | *answerp2_malloced = 0; | |
509 | } | |
510 | if (saved_herrno != -1) | |
511 | RES_SET_H_ERRNO(statp, saved_herrno); | |
512 | else if (got_nodata) | |
513 | RES_SET_H_ERRNO(statp, NO_DATA); | |
514 | else if (got_servfail) | |
515 | RES_SET_H_ERRNO(statp, TRY_AGAIN); | |
516 | return (-1); | |
517 | } | |
518 | libresolv_hidden_def (__res_context_search) | |
519 | ||
520 | /* Common part of res_nsearch and res_search. */ | |
521 | static int | |
522 | context_search_common (struct resolv_context *ctx, | |
523 | const char *name, int class, int type, | |
524 | unsigned char *answer, int anslen) | |
525 | { | |
526 | if (ctx == NULL) | |
527 | { | |
528 | RES_SET_H_ERRNO (&_res, NETDB_INTERNAL); | |
529 | return -1; | |
530 | } | |
531 | int result = __res_context_search (ctx, name, class, type, answer, anslen, | |
532 | NULL, NULL, NULL, NULL, NULL); | |
533 | __resolv_context_put (ctx); | |
534 | return result; | |
535 | } | |
536 | ||
537 | int | |
538 | res_nsearch(res_state statp, | |
539 | const char *name, /* domain name */ | |
540 | int class, int type, /* class and type of query */ | |
541 | u_char *answer, /* buffer to put answer */ | |
542 | int anslen) /* size of answer */ | |
543 | { | |
544 | return context_search_common | |
545 | (__resolv_context_get_override (statp), name, class, type, answer, anslen); | |
546 | } | |
547 | ||
548 | int | |
549 | res_search (const char *name, int class, int type, | |
550 | unsigned char *answer, int anslen) | |
551 | { | |
552 | return context_search_common | |
553 | (__resolv_context_get (), name, class, type, answer, anslen); | |
554 | } | |
555 | ||
556 | /* Perform a call on res_query on the concatenation of name and | |
557 | domain. */ | |
558 | static int | |
559 | __res_context_querydomain (struct resolv_context *ctx, | |
560 | const char *name, const char *domain, | |
561 | int class, int type, | |
562 | unsigned char *answer, int anslen, | |
563 | unsigned char **answerp, unsigned char **answerp2, | |
564 | int *nanswerp2, int *resplen2, | |
565 | int *answerp2_malloced) | |
566 | { | |
567 | struct __res_state *statp = ctx->resp; | |
568 | char nbuf[MAXDNAME]; | |
569 | const char *longname = nbuf; | |
570 | size_t n, d; | |
571 | ||
572 | if (domain == NULL) { | |
573 | n = strlen(name); | |
574 | ||
575 | /* Decrement N prior to checking it against MAXDNAME | |
576 | so that we detect a wrap to SIZE_MAX and return | |
577 | a reasonable error. */ | |
578 | n--; | |
579 | if (n >= MAXDNAME - 1) { | |
580 | RES_SET_H_ERRNO(statp, NO_RECOVERY); | |
581 | return (-1); | |
582 | } | |
583 | longname = name; | |
584 | } else { | |
585 | n = strlen(name); | |
586 | d = strlen(domain); | |
587 | if (n + d + 1 >= MAXDNAME) { | |
588 | RES_SET_H_ERRNO(statp, NO_RECOVERY); | |
589 | return (-1); | |
590 | } | |
591 | sprintf(nbuf, "%s.%s", name, domain); | |
592 | } | |
593 | return __res_context_query (ctx, longname, class, type, answer, | |
594 | anslen, answerp, answerp2, nanswerp2, | |
595 | resplen2, answerp2_malloced); | |
596 | } | |
597 | ||
598 | /* Common part of res_nquerydomain and res_querydomain. */ | |
599 | static int | |
600 | context_querydomain_common (struct resolv_context *ctx, | |
601 | const char *name, const char *domain, | |
602 | int class, int type, | |
603 | unsigned char *answer, int anslen) | |
604 | { | |
605 | if (ctx == NULL) | |
606 | { | |
607 | RES_SET_H_ERRNO (&_res, NETDB_INTERNAL); | |
608 | return -1; | |
609 | } | |
610 | int result = __res_context_querydomain (ctx, name, domain, class, type, | |
611 | answer, anslen, | |
612 | NULL, NULL, NULL, NULL, NULL); | |
613 | __resolv_context_put (ctx); | |
614 | return result; | |
615 | } | |
616 | ||
617 | int | |
618 | res_nquerydomain(res_state statp, | |
619 | const char *name, | |
620 | const char *domain, | |
621 | int class, int type, /* class and type of query */ | |
622 | u_char *answer, /* buffer to put answer */ | |
623 | int anslen) /* size of answer */ | |
624 | { | |
625 | return context_querydomain_common | |
626 | (__resolv_context_get_override (statp), | |
627 | name, domain, class, type, answer, anslen); | |
628 | } | |
629 | ||
630 | int | |
631 | res_querydomain (const char *name, const char *domain, int class, int type, | |
632 | unsigned char *answer, int anslen) | |
633 | { | |
634 | return context_querydomain_common | |
635 | (__resolv_context_get (), name, domain, class, type, answer, anslen); | |
636 | } | |
637 | ||
638 | const char * | |
639 | __res_context_hostalias (struct resolv_context *ctx, | |
640 | const char *name, char *dst, size_t siz) | |
641 | { | |
642 | char *file, *cp1, *cp2; | |
643 | char buf[BUFSIZ]; | |
644 | FILE *fp; | |
645 | ||
646 | if (ctx->resp->options & RES_NOALIASES) | |
647 | return (NULL); | |
648 | file = getenv("HOSTALIASES"); | |
649 | if (file == NULL || (fp = fopen(file, "rce")) == NULL) | |
650 | return (NULL); | |
651 | setbuf(fp, NULL); | |
652 | buf[sizeof(buf) - 1] = '\0'; | |
653 | while (fgets(buf, sizeof(buf), fp)) { | |
654 | for (cp1 = buf; *cp1 && !isspace(*cp1); ++cp1) | |
655 | ; | |
656 | if (!*cp1) | |
657 | break; | |
658 | *cp1 = '\0'; | |
659 | if (ns_samename(buf, name) == 1) { | |
660 | while (isspace(*++cp1)) | |
661 | ; | |
662 | if (!*cp1) | |
663 | break; | |
664 | for (cp2 = cp1 + 1; *cp2 && !isspace(*cp2); ++cp2) | |
665 | ; | |
666 | *cp2 = '\0'; | |
667 | strncpy(dst, cp1, siz - 1); | |
668 | dst[siz - 1] = '\0'; | |
669 | fclose(fp); | |
670 | return (dst); | |
671 | } | |
672 | } | |
673 | fclose(fp); | |
674 | return (NULL); | |
675 | } | |
676 | libresolv_hidden_def (__res_context_hostalias) | |
677 | ||
678 | /* Common part of res_hostalias and hostalias. */ | |
679 | static const char * | |
680 | context_hostalias_common (struct resolv_context *ctx, | |
681 | const char *name, char *dst, size_t siz) | |
682 | { | |
683 | if (ctx == NULL) | |
684 | { | |
685 | RES_SET_H_ERRNO (&_res, NETDB_INTERNAL); | |
686 | return NULL; | |
687 | } | |
688 | const char *result = __res_context_hostalias (ctx, name, dst, siz); | |
689 | __resolv_context_put (ctx); | |
690 | return result; | |
691 | } | |
692 | ||
693 | const char * | |
694 | res_hostalias (res_state statp, const char *name, char *dst, size_t siz) | |
695 | { | |
696 | return context_hostalias_common | |
697 | (__resolv_context_get_override (statp), name, dst, siz); | |
698 | } | |
699 | ||
700 | const char * | |
701 | hostalias (const char *name) | |
702 | { | |
703 | static char abuf[MAXDNAME]; | |
704 | return context_hostalias_common | |
705 | (__resolv_context_get (), name, abuf, sizeof (abuf)); | |
706 | } | |
707 | ||
708 | #if SHLIB_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_2) | |
709 | # undef res_query | |
710 | # undef res_querydomain | |
711 | # undef res_search | |
712 | weak_alias (__res_query, res_query); | |
713 | weak_alias (__res_querydomain, res_querydomain); | |
714 | weak_alias (__res_search, res_search); | |
715 | #endif |