1 /* $NetBSD: res_data.c,v 1.14 2009/10/24 05:35:37 christos Exp $ */
2
3 /*
4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (c) 1995-1999 by Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 #include <sys/cdefs.h>
21 #if defined(LIBC_SCCS) && !defined(lint)
22 #ifdef notdef
23 static const char rcsid[] = "Id: res_data.c,v 1.7 2008/12/11 09:59:00 marka Exp";
24 #else
25 __RCSID("$NetBSD: res_data.c,v 1.14 2009/10/24 05:35:37 christos Exp $");
26 #endif
27 #endif /* LIBC_SCCS and not lint */
28
29 #include "port_before.h"
30
31 #include <sys/types.h>
32 #include <sys/param.h>
33 #include <sys/socket.h>
34 #include <sys/time.h>
35
36 #include <netinet/in.h>
37 #include <arpa/inet.h>
38 #include <arpa/nameser.h>
39
40 #include <ctype.h>
41 #include <netdb.h>
42 #include <resolv.h>
43 #include <res_update.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48
49 #include "port_after.h"
50
51 #include "res_private.h"
52
53 #ifdef __weak_alias
54 __weak_alias(res_init,_res_init)
55 __weak_alias(res_mkquery,_res_mkquery)
56 __weak_alias(res_query,_res_query)
57 __weak_alias(res_search,_res_search)
58 __weak_alias(res_send,__res_send)
59 __weak_alias(res_close,__res_close)
60 /* XXX: these leaked in the old bind8 libc */
61 __weak_alias(res_querydomain,__res_querydomain)
62 __weak_alias(res_send_setqhook,__res_send_setqhook)
63 __weak_alias(res_send_setrhook,__res_send_setrhook)
64 #if 0
65 __weak_alias(p_query,__p_query)
66 __weak_alias(fp_query,__fp_query)
67 __weak_alias(fp_nquery,__fp_nquery)
68 __weak_alias(res_isourserver,__res_isourserver)
69 __weak_alias(res_opt,_res_opt)
70 __weak_alias(hostalias,__hostalias)
71 #endif
72 #endif
73
74 const char *_res_opcodes[] = {
75 "QUERY",
76 "IQUERY",
77 "CQUERYM",
78 "CQUERYU", /*%< experimental */
79 "NOTIFY", /*%< experimental */
80 "UPDATE",
81 "6",
82 "7",
83 "8",
84 "9",
85 "10",
86 "11",
87 "12",
88 "13",
89 "ZONEINIT",
90 "ZONEREF",
91 };
92
93 #ifdef BIND_UPDATE
94 const char *_res_sectioncodes[] = {
95 "ZONE",
96 "PREREQUISITES",
97 "UPDATE",
98 "ADDITIONAL",
99 };
100 #endif
101
102 #ifndef __BIND_NOSTATIC
103 extern struct __res_state _nres;
104
105 /* Proto. */
106
107 int res_ourserver_p(const res_state, const struct sockaddr *);
108
109 int
res_init(void)110 res_init(void) {
111 int rv;
112 #ifdef COMPAT__RES
113 /*
114 * Compatibility with program that were accessing _res directly
115 * to set options. We keep another struct res that is the same
116 * size as the original res structure, and then copy fields to
117 * it so that we achieve the same initialization
118 */
119 extern void *__res_get_old_state(void);
120 extern void __res_put_old_state(void *);
121 res_state ores = __res_get_old_state();
122
123 if (ores->options != 0)
124 _nres.options = ores->options;
125 if (ores->retrans != 0)
126 _nres.retrans = ores->retrans;
127 if (ores->retry != 0)
128 _nres.retry = ores->retry;
129 #endif
130
131 /*
132 * These three fields used to be statically initialized. This made
133 * it hard to use this code in a shared library. It is necessary,
134 * now that we're doing dynamic initialization here, that we preserve
135 * the old semantics: if an application modifies one of these three
136 * fields of _res before res_init() is called, res_init() will not
137 * alter them. Of course, if an application is setting them to
138 * _zero_ before calling res_init(), hoping to override what used
139 * to be the static default, we can't detect it and unexpected results
140 * will follow. Zero for any of these fields would make no sense,
141 * so one can safely assume that the applications were already getting
142 * unexpected results.
143 *
144 * _nres.options is tricky since some apps were known to diddle the bits
145 * before res_init() was first called. We can't replicate that semantic
146 * with dynamic initialization (they may have turned bits off that are
147 * set in RES_DEFAULT). Our solution is to declare such applications
148 * "broken". They could fool us by setting RES_INIT but none do (yet).
149 */
150 if (!_nres.retrans)
151 _nres.retrans = RES_TIMEOUT;
152 if (!_nres.retry)
153 _nres.retry = 4;
154 if (!(_nres.options & RES_INIT))
155 _nres.options = RES_DEFAULT;
156
157 /*
158 * This one used to initialize implicitly to zero, so unless the app
159 * has set it to something in particular, we can randomize it now.
160 */
161 if (!_nres.id)
162 _nres.id = res_nrandomid(&_nres);
163
164 rv = __res_vinit(&_nres, 1);
165 #ifdef COMPAT__RES
166 __res_put_old_state(&_nres);
167 #endif
168 return rv;
169 }
170
171 void
p_query(const u_char * msg)172 p_query(const u_char *msg) {
173 fp_query(msg, stdout);
174 }
175
176 void
fp_query(const u_char * msg,FILE * file)177 fp_query(const u_char *msg, FILE *file) {
178 fp_nquery(msg, PACKETSZ, file);
179 }
180
181 void
fp_nquery(const u_char * msg,int len,FILE * file)182 fp_nquery(const u_char *msg, int len, FILE *file) {
183 if ((_nres.options & RES_INIT) == 0U && res_init() == -1)
184 return;
185
186 res_pquery(&_nres, msg, len, file);
187 }
188
189 int
res_mkquery(int op,const char * dname,int class,int type,const u_char * data,int datalen,const u_char * newrr_in,u_char * buf,int buflen)190 res_mkquery(int op, /*!< opcode of query */
191 const char *dname, /*!< domain name */
192 int class, int type, /*!< class and type of query */
193 const u_char *data, /*!< resource record data */
194 int datalen, /*!< length of data */
195 const u_char *newrr_in, /*!< new rr for modify or append */
196 u_char *buf, /*!< buffer to put query */
197 int buflen) /*!< size of buffer */
198 {
199 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
200 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
201 return (-1);
202 }
203 return (res_nmkquery(&_nres, op, dname, class, type,
204 data, datalen,
205 newrr_in, buf, buflen));
206 }
207
208 #ifdef _LIBRESOLV
209 int
res_mkupdate(ns_updrec * rrecp_in,u_char * buf,int buflen)210 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
211 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
212 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
213 return (-1);
214 }
215
216 return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
217 }
218 #endif
219
220 int
res_query(const char * name,int class,int type,u_char * answer,int anslen)221 res_query(const char *name, /*!< domain name */
222 int class, int type, /*!< class and type of query */
223 u_char *answer, /*!< buffer to put answer */
224 int anslen) /*!< size of answer buffer */
225 {
226 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
227 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
228 return (-1);
229 }
230 return (res_nquery(&_nres, name, class, type, answer, anslen));
231 }
232
233 void
res_send_setqhook(res_send_qhook hook)234 res_send_setqhook(res_send_qhook hook) {
235 _nres.qhook = hook;
236 }
237
238 void
res_send_setrhook(res_send_rhook hook)239 res_send_setrhook(res_send_rhook hook) {
240 _nres.rhook = hook;
241 }
242
243 int
res_isourserver(const struct sockaddr_in * inp)244 res_isourserver(const struct sockaddr_in *inp) {
245 return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
246 }
247
248 int
res_send(const u_char * buf,int buflen,u_char * ans,int anssiz)249 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
250 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
251 /* errno should have been set by res_init() in this case. */
252 return (-1);
253 }
254
255 return (res_nsend(&_nres, buf, buflen, ans, anssiz));
256 }
257
258 #ifdef _LIBRESOLV
259 int
res_sendsigned(const u_char * buf,int buflen,ns_tsig_key * key,u_char * ans,int anssiz)260 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
261 u_char *ans, int anssiz)
262 {
263 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
264 /* errno should have been set by res_init() in this case. */
265 return (-1);
266 }
267
268 return (res_nsendsigned(&_nres, buf, buflen, key, ans, anssiz));
269 }
270 #endif
271
272 void
res_close(void)273 res_close(void) {
274 res_nclose(&_nres);
275 }
276
277 #ifdef _LIBRESOLV
278 int
res_update(ns_updrec * rrecp_in)279 res_update(ns_updrec *rrecp_in) {
280 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
281 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
282 return (-1);
283 }
284
285 return (res_nupdate(&_nres, rrecp_in, NULL));
286 }
287 #endif
288
289 int
res_search(const char * name,int class,int type,u_char * answer,int anslen)290 res_search(const char *name, /*!< domain name */
291 int class, int type, /*!< class and type of query */
292 u_char *answer, /*!< buffer to put answer */
293 int anslen) /*!< size of answer */
294 {
295 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
296 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
297 return (-1);
298 }
299
300 return (res_nsearch(&_nres, name, class, type, answer, anslen));
301 }
302
303 int
res_querydomain(const char * name,const char * domain,int class,int type,u_char * answer,int anslen)304 res_querydomain(const char *name,
305 const char *domain,
306 int class, int type, /*!< class and type of query */
307 u_char *answer, /*!< buffer to put answer */
308 int anslen) /*!< size of answer */
309 {
310 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
311 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
312 return (-1);
313 }
314
315 return (res_nquerydomain(&_nres, name, domain,
316 class, type,
317 answer, anslen));
318 }
319
320 int
res_opt(int a,u_char * b,int c,int d)321 res_opt(int a, u_char *b, int c, int d)
322 {
323 return res_nopt(&_nres, a, b, c, d);
324 }
325
326 u_int
res_randomid(void)327 res_randomid(void) {
328 if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
329 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
330 return (u_int)-1;
331 }
332
333 return (res_nrandomid(&_nres));
334 }
335
336 const char *
hostalias(const char * name)337 hostalias(const char *name) {
338 static char abuf[MAXDNAME];
339
340 return (res_hostalias(&_nres, name, abuf, sizeof abuf));
341 }
342
343 #ifdef ultrix
344 int
local_hostname_length(const char * hostname)345 local_hostname_length(const char *hostname) {
346 int len_host, len_domain;
347
348 if (!*_nres.defdname)
349 res_init();
350 len_host = strlen(hostname);
351 len_domain = strlen(_nres.defdname);
352 if (len_host > len_domain &&
353 !strcasecmp(hostname + len_host - len_domain, _nres.defdname) &&
354 hostname[len_host - len_domain - 1] == '.')
355 return (len_host - len_domain - 1);
356 return (0);
357 }
358 #endif /*ultrix*/
359
360 #endif
361
362 /*! \file */
363