1 /* $NetBSD: res_data.c,v 1.8 2004/06/09 18:07:03 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 1.1.206.2 2004/03/16 12:34:18 marka Exp";
24 #else
25 __RCSID("$NetBSD: res_data.c,v 1.8 2004/06/09 18:07:03 christos Exp $");
26 #endif
27 #endif /* LIBC_SCCS and not lint */
28
29
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_private.h"
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47
48
49 __LIBC_HIDDEN__
50 const char * const _res_opcodes[] = {
51 "QUERY",
52 "IQUERY",
53 "CQUERYM",
54 "CQUERYU", /* experimental */
55 "NOTIFY", /* experimental */
56 "UPDATE",
57 "6",
58 "7",
59 "8",
60 "9",
61 "10",
62 "11",
63 "12",
64 "13",
65 "ZONEINIT",
66 "ZONEREF",
67 };
68
69 #ifdef BIND_UPDATE
70 const char * const _res_sectioncodes[] = {
71 "ZONE",
72 "PREREQUISITES",
73 "UPDATE",
74 "ADDITIONAL",
75 };
76 #endif
77
78 #ifndef __BIND_NOSTATIC
79 extern struct __res_state _nres;
80
81 /* Proto. */
82
83 int res_ourserver_p(const res_state, const struct sockaddr *);
84
85 #ifdef ANDROID_CHANGES
res_need_init()86 static int res_need_init() {
87 return ((_nres.options & RES_INIT) == 0U) || res_get_dns_changed();
88 }
89 #else
90 #define res_need_init() ((_nres.options & RES_INIT) == 0U)
91 #endif
92
93 int
res_init(void)94 res_init(void) {
95 int rv;
96 extern int __res_vinit(res_state, int);
97 #ifdef COMPAT__RES
98 /*
99 * Compatibility with program that were accessing _res directly
100 * to set options. We keep another struct res that is the same
101 * size as the original res structure, and then copy fields to
102 * it so that we achieve the same initialization
103 */
104 extern void *__res_get_old_state(void);
105 extern void __res_put_old_state(void *);
106 res_state ores = __res_get_old_state();
107
108 if (ores->options != 0)
109 _nres.options = ores->options;
110 if (ores->retrans != 0)
111 _nres.retrans = ores->retrans;
112 if (ores->retry != 0)
113 _nres.retry = ores->retry;
114 #endif
115
116 /*
117 * These three fields used to be statically initialized. This made
118 * it hard to use this code in a shared library. It is necessary,
119 * now that we're doing dynamic initialization here, that we preserve
120 * the old semantics: if an application modifies one of these three
121 * fields of _res before res_init() is called, res_init() will not
122 * alter them. Of course, if an application is setting them to
123 * _zero_ before calling res_init(), hoping to override what used
124 * to be the static default, we can't detect it and unexpected results
125 * will follow. Zero for any of these fields would make no sense,
126 * so one can safely assume that the applications were already getting
127 * unexpected results.
128 *
129 * _nres.options is tricky since some apps were known to diddle the bits
130 * before res_init() was first called. We can't replicate that semantic
131 * with dynamic initialization (they may have turned bits off that are
132 * set in RES_DEFAULT). Our solution is to declare such applications
133 * "broken". They could fool us by setting RES_INIT but none do (yet).
134 */
135 if (!_nres.retrans)
136 _nres.retrans = RES_TIMEOUT;
137 if (!_nres.retry)
138 _nres.retry = 4;
139 if (!(_nres.options & RES_INIT))
140 _nres.options = RES_DEFAULT;
141
142 /*
143 * This one used to initialize implicitly to zero, so unless the app
144 * has set it to something in particular, we can randomize it now.
145 */
146 if (!_nres.id)
147 _nres.id = res_randomid();
148
149 rv = __res_vinit(&_nres, 1);
150 #ifdef COMPAT__RES
151 __res_put_old_state(&_nres);
152 #endif
153 return rv;
154 }
155
156 void
p_query(const u_char * msg)157 p_query(const u_char *msg) {
158 fp_query(msg, stdout);
159 }
160
161 void
fp_query(const u_char * msg,FILE * file)162 fp_query(const u_char *msg, FILE *file) {
163 fp_nquery(msg, PACKETSZ, file);
164 }
165
166 void
fp_nquery(const u_char * msg,int len,FILE * file)167 fp_nquery(const u_char *msg, int len, FILE *file) {
168 if (res_need_init() && res_init() == -1)
169 return;
170
171 res_pquery(&_nres, msg, len, file);
172 }
173
174 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)175 res_mkquery(int op, /* opcode of query */
176 const char *dname, /* domain name */
177 int class, int type, /* class and type of query */
178 const u_char *data, /* resource record data */
179 int datalen, /* length of data */
180 const u_char *newrr_in, /* new rr for modify or append */
181 u_char *buf, /* buffer to put query */
182 int buflen) /* size of buffer */
183 {
184 if (res_need_init() && res_init() == -1) {
185 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
186 return (-1);
187 }
188 return (res_nmkquery(&_nres, op, dname, class, type,
189 data, datalen,
190 newrr_in, buf, buflen));
191 }
192
193 #ifdef _LIBRESOLV
194 int
res_mkupdate(ns_updrec * rrecp_in,u_char * buf,int buflen)195 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
196 if (res_need_init() && res_init() == -1) {
197 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
198 return (-1);
199 }
200
201 return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
202 }
203 #endif
204
205 int
res_query(const char * name,int class,int type,u_char * answer,int anslen)206 res_query(const char *name, /* domain name */
207 int class, int type, /* class and type of query */
208 u_char *answer, /* buffer to put answer */
209 int anslen) /* size of answer buffer */
210 {
211 if (res_need_init() && res_init() == -1) {
212 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
213 return (-1);
214 }
215 return (res_nquery(&_nres, name, class, type, answer, anslen));
216 }
217
218 void
res_send_setqhook(res_send_qhook hook)219 res_send_setqhook(res_send_qhook hook) {
220 _nres.qhook = hook;
221 }
222
223 void
res_send_setrhook(res_send_rhook hook)224 res_send_setrhook(res_send_rhook hook) {
225 _nres.rhook = hook;
226 }
227
228 int
res_isourserver(const struct sockaddr_in * inp)229 res_isourserver(const struct sockaddr_in *inp) {
230 return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
231 }
232
233 int
res_send(const u_char * buf,int buflen,u_char * ans,int anssiz)234 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
235 if (res_need_init() && res_init() == -1) {
236 /* errno should have been set by res_init() in this case. */
237 return (-1);
238 }
239
240 return (res_nsend(&_nres, buf, buflen, ans, anssiz));
241 }
242
243 #ifdef _LIBRESOLV
244 int
res_sendsigned(const u_char * buf,int buflen,ns_tsig_key * key,u_char * ans,int anssiz)245 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
246 u_char *ans, int anssiz)
247 {
248 if (res_need_init() && res_init() == -1) {
249 /* errno should have been set by res_init() in this case. */
250 return (-1);
251 }
252
253 return (res_nsendsigned(&_nres, buf, buflen, key, ans, anssiz));
254 }
255 #endif
256
257 void
res_close(void)258 res_close(void) {
259 res_nclose(&_nres);
260 }
261
262 #ifdef _LIBRESOLV
263 int
res_update(ns_updrec * rrecp_in)264 res_update(ns_updrec *rrecp_in) {
265 if (res_need_init() && res_init() == -1) {
266 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
267 return (-1);
268 }
269
270 return (res_nupdate(&_nres, rrecp_in, NULL));
271 }
272 #endif
273
274 int
res_search(const char * name,int class,int type,u_char * answer,int anslen)275 res_search(const char *name, /* domain name */
276 int class, int type, /* class and type of query */
277 u_char *answer, /* buffer to put answer */
278 int anslen) /* size of answer */
279 {
280 if (res_need_init() && res_init() == -1) {
281 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
282 return (-1);
283 }
284
285 return (res_nsearch(&_nres, name, class, type, answer, anslen));
286 }
287
288 int
res_querydomain(const char * name,const char * domain,int class,int type,u_char * answer,int anslen)289 res_querydomain(const char *name,
290 const char *domain,
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 (res_need_init() && res_init() == -1) {
296 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
297 return (-1);
298 }
299
300 return (res_nquerydomain(&_nres, name, domain,
301 class, type,
302 answer, anslen));
303 }
304
305 int
res_opt(int a,u_char * b,int c,int d)306 res_opt(int a, u_char *b, int c, int d)
307 {
308 return res_nopt(&_nres, a, b, c, d);
309 }
310
311 const char *
hostalias(const char * name)312 hostalias(const char *name) {
313 return NULL;
314 }
315
316 #ifdef ultrix
317 int
local_hostname_length(const char * hostname)318 local_hostname_length(const char *hostname) {
319 int len_host, len_domain;
320
321 if (!*_nres.defdname)
322 res_init();
323 len_host = strlen(hostname);
324 len_domain = strlen(_nres.defdname);
325 if (len_host > len_domain &&
326 !strcasecmp(hostname + len_host - len_domain, _nres.defdname) &&
327 hostname[len_host - len_domain - 1] == '.')
328 return (len_host - len_domain - 1);
329 return (0);
330 }
331 #endif /*ultrix*/
332
333 #endif
334