xref: /freebsd/lib/libc/resolv/res_data.c (revision 8fc257994d0ce2396196d7a06d50d20c8015f4b7)
1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1995-1999 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 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char rcsid[] = "$Id: res_data.c,v 1.3.18.2 2007/09/14 05:35:47 marka Exp $";
20 #endif /* LIBC_SCCS and not lint */
21 #include <sys/cdefs.h>
22 __FBSDID("$FreeBSD$");
23 
24 #include "port_before.h"
25 
26 #include <sys/types.h>
27 #include <sys/param.h>
28 #include <sys/socket.h>
29 #include <sys/time.h>
30 
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
33 #include <arpa/nameser.h>
34 
35 #include <ctype.h>
36 #include <netdb.h>
37 #include <resolv.h>
38 #include <res_update.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #include "port_after.h"
45 
46 const char *_res_opcodes[] = {
47 	"QUERY",
48 	"IQUERY",
49 	"CQUERYM",
50 	"CQUERYU",	/*%< experimental */
51 	"NOTIFY",	/*%< experimental */
52 	"UPDATE",
53 	"6",
54 	"7",
55 	"8",
56 	"9",
57 	"10",
58 	"11",
59 	"12",
60 	"13",
61 	"ZONEINIT",
62 	"ZONEREF",
63 };
64 
65 #ifdef BIND_UPDATE
66 const char *_res_sectioncodes[] = {
67 	"ZONE",
68 	"PREREQUISITES",
69 	"UPDATE",
70 	"ADDITIONAL",
71 };
72 #endif
73 
74 #ifndef __BIND_NOSTATIC
75 
76 /* Proto. */
77 
78 int  res_ourserver_p(const res_state, const struct sockaddr_in *);
79 
80 int
81 res_init(void) {
82 	extern int __res_vinit(res_state, int);
83 
84 	/*
85 	 * These three fields used to be statically initialized.  This made
86 	 * it hard to use this code in a shared library.  It is necessary,
87 	 * now that we're doing dynamic initialization here, that we preserve
88 	 * the old semantics: if an application modifies one of these three
89 	 * fields of _res before res_init() is called, res_init() will not
90 	 * alter them.  Of course, if an application is setting them to
91 	 * _zero_ before calling res_init(), hoping to override what used
92 	 * to be the static default, we can't detect it and unexpected results
93 	 * will follow.  Zero for any of these fields would make no sense,
94 	 * so one can safely assume that the applications were already getting
95 	 * unexpected results.
96 	 *
97 	 * _res.options is tricky since some apps were known to diddle the bits
98 	 * before res_init() was first called. We can't replicate that semantic
99 	 * with dynamic initialization (they may have turned bits off that are
100 	 * set in RES_DEFAULT).  Our solution is to declare such applications
101 	 * "broken".  They could fool us by setting RES_INIT but none do (yet).
102 	 */
103 	if (!_res.retrans)
104 		_res.retrans = RES_TIMEOUT;
105 	if (!_res.retry)
106 		_res.retry = RES_DFLRETRY;
107 	if (!(_res.options & RES_INIT))
108 		_res.options = RES_DEFAULT;
109 
110 	/*
111 	 * This one used to initialize implicitly to zero, so unless the app
112 	 * has set it to something in particular, we can randomize it now.
113 	 */
114 	if (!_res.id)
115 		_res.id = res_randomid();
116 
117 	return (__res_vinit(&_res, 1));
118 }
119 
120 void
121 p_query(const u_char *msg) {
122 	fp_query(msg, stdout);
123 }
124 
125 void
126 fp_query(const u_char *msg, FILE *file) {
127 	fp_nquery(msg, PACKETSZ, file);
128 }
129 
130 void
131 fp_nquery(const u_char *msg, int len, FILE *file) {
132 	if ((_res.options & RES_INIT) == 0U && res_init() == -1)
133 		return;
134 
135 	res_pquery(&_res, msg, len, file);
136 }
137 
138 int
139 res_mkquery(int op,			/*!< opcode of query  */
140 	    const char *dname,		/*!< domain name  */
141 	    int class, int type,	/*!< class and type of query  */
142 	    const u_char *data,		/*!< resource record data  */
143 	    int datalen,		/*!< length of data  */
144 	    const u_char *newrr_in,	/*!< new rr for modify or append  */
145 	    u_char *buf,		/*!< buffer to put query  */
146 	    int buflen)			/*!< size of buffer  */
147 {
148 	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
149 		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
150 		return (-1);
151 	}
152 	return (res_nmkquery(&_res, op, dname, class, type,
153 			     data, datalen,
154 			     newrr_in, buf, buflen));
155 }
156 
157 int
158 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
159 	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
160 		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
161 		return (-1);
162 	}
163 
164 	return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
165 }
166 
167 int
168 res_query(const char *name,	/*!< domain name  */
169 	  int class, int type,	/*!< class and type of query  */
170 	  u_char *answer,	/*!< buffer to put answer  */
171 	  int anslen)		/*!< size of answer buffer  */
172 {
173 	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
174 		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
175 		return (-1);
176 	}
177 	return (res_nquery(&_res, name, class, type, answer, anslen));
178 }
179 
180 #ifndef _LIBC
181 void
182 res_send_setqhook(res_send_qhook hook) {
183 	_res.qhook = hook;
184 }
185 
186 void
187 res_send_setrhook(res_send_rhook hook) {
188 	_res.rhook = hook;
189 }
190 #endif
191 
192 int
193 res_isourserver(const struct sockaddr_in *inp) {
194 	return (res_ourserver_p(&_res, inp));
195 }
196 
197 int
198 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
199 	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
200 		/* errno should have been set by res_init() in this case. */
201 		return (-1);
202 	}
203 
204 	return (res_nsend(&_res, buf, buflen, ans, anssiz));
205 }
206 
207 #ifndef _LIBC
208 int
209 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
210 	       u_char *ans, int anssiz)
211 {
212 	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
213 		/* errno should have been set by res_init() in this case. */
214 		return (-1);
215 	}
216 
217 	return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
218 }
219 #endif
220 
221 void
222 res_close(void) {
223 	res_nclose(&_res);
224 }
225 
226 int
227 res_update(ns_updrec *rrecp_in) {
228 	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
229 		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
230 		return (-1);
231 	}
232 
233 	return (res_nupdate(&_res, rrecp_in, NULL));
234 }
235 
236 int
237 res_search(const char *name,	/*!< domain name  */
238 	   int class, int type,	/*!< class and type of query  */
239 	   u_char *answer,	/*!< buffer to put answer  */
240 	   int anslen)		/*!< size of answer  */
241 {
242 	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
243 		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
244 		return (-1);
245 	}
246 
247 	return (res_nsearch(&_res, name, class, type, answer, anslen));
248 }
249 
250 int
251 res_querydomain(const char *name,
252 		const char *domain,
253 		int class, int type,	/*!< class and type of query  */
254 		u_char *answer,		/*!< buffer to put answer  */
255 		int anslen)		/*!< size of answer  */
256 {
257 	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
258 		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
259 		return (-1);
260 	}
261 
262 	return (res_nquerydomain(&_res, name, domain,
263 				 class, type,
264 				 answer, anslen));
265 }
266 
267 int
268 res_opt(int n0, u_char *buf, int buflen, int anslen)
269 {
270 	return (res_nopt(&_res, n0, buf, buflen, anslen));
271 }
272 
273 const char *
274 hostalias(const char *name) {
275 	static char abuf[MAXDNAME];
276 
277 	return (res_hostalias(&_res, name, abuf, sizeof abuf));
278 }
279 
280 #ifdef ultrix
281 int
282 local_hostname_length(const char *hostname) {
283 	int len_host, len_domain;
284 
285 	if (!*_res.defdname)
286 		res_init();
287 	len_host = strlen(hostname);
288 	len_domain = strlen(_res.defdname);
289 	if (len_host > len_domain &&
290 	    !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
291 	    hostname[len_host - len_domain - 1] == '.')
292 		return (len_host - len_domain - 1);
293 	return (0);
294 }
295 #endif /*ultrix*/
296 
297 /*
298  * Weak aliases for applications that use certain private entry points,
299  * and fail to include <resolv.h>.
300  */
301 #undef res_init
302 __weak_reference(__res_init, res_init);
303 #undef p_query
304 __weak_reference(__p_query, p_query);
305 #undef res_mkquery
306 __weak_reference(__res_mkquery, res_mkquery);
307 #undef res_query
308 __weak_reference(__res_query, res_query);
309 #undef res_send
310 __weak_reference(__res_send, res_send);
311 #undef res_close
312 __weak_reference(__res_close, _res_close);
313 #undef res_search
314 __weak_reference(__res_search, res_search);
315 #undef res_querydomain
316 __weak_reference(__res_querydomain, res_querydomain);
317 
318 #endif
319 
320 /*! \file */
321