1/*	$NetBSD: res_data.c,v 1.15 2024/01/23 17:24:38 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
23static 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 1.15 2024/01/23 17:24:38 christos Exp $");
26#endif
27#endif /* LIBC_SCCS and not lint */
28
29#include "port_before.h"
30
31#include "namespace.h"
32#include <sys/types.h>
33#include <sys/param.h>
34#include <sys/socket.h>
35#include <sys/time.h>
36
37#include <netinet/in.h>
38#include <arpa/inet.h>
39#include <arpa/nameser.h>
40
41#include <ctype.h>
42#include <netdb.h>
43#include <resolv.h>
44#include <res_update.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48#include <unistd.h>
49
50#include "port_after.h"
51
52#include "res_private.h"
53
54#ifdef __weak_alias
55__weak_alias(res_init,_res_init)
56__weak_alias(res_mkquery,_res_mkquery)
57__weak_alias(res_query,_res_query)
58__weak_alias(res_search,_res_search)
59__weak_alias(res_send,__res_send)
60__weak_alias(res_close,__res_close)
61/* XXX: these leaked in the old bind8 libc */
62__weak_alias(res_querydomain,__res_querydomain)
63__weak_alias(res_send_setqhook,__res_send_setqhook)
64__weak_alias(res_send_setrhook,__res_send_setrhook)
65#if 0
66__weak_alias(p_query,__p_query)
67__weak_alias(fp_query,__fp_query)
68__weak_alias(fp_nquery,__fp_nquery)
69__weak_alias(res_isourserver,__res_isourserver)
70__weak_alias(res_opt,_res_opt)
71__weak_alias(hostalias,__hostalias)
72#endif
73#endif
74
75const char *_res_opcodes[] = {
76	"QUERY",
77	"IQUERY",
78	"CQUERYM",
79	"CQUERYU",	/*%< experimental */
80	"NOTIFY",	/*%< experimental */
81	"UPDATE",
82	"6",
83	"7",
84	"8",
85	"9",
86	"10",
87	"11",
88	"12",
89	"13",
90	"ZONEINIT",
91	"ZONEREF",
92};
93
94#ifdef BIND_UPDATE
95const char *_res_sectioncodes[] = {
96	"ZONE",
97	"PREREQUISITES",
98	"UPDATE",
99	"ADDITIONAL",
100};
101#endif
102
103#ifndef __BIND_NOSTATIC
104extern struct __res_state _nres;
105
106/* Proto. */
107
108int  res_ourserver_p(const res_state, const struct sockaddr *);
109
110int
111res_init(void) {
112	int rv;
113#ifdef COMPAT__RES
114	/*
115	 * Compatibility with program that were accessing _res directly
116	 * to set options. We keep another struct res that is the same
117	 * size as the original res structure, and then copy fields to
118	 * it so that we achieve the same initialization
119	 */
120	res_state ores = __res_get_old_state();
121
122	if (ores->options != 0)
123		_nres.options = ores->options;
124	if (ores->retrans != 0)
125		_nres.retrans = ores->retrans;
126	if (ores->retry != 0)
127		_nres.retry = ores->retry;
128#endif
129
130	/*
131	 * These three fields used to be statically initialized.  This made
132	 * it hard to use this code in a shared library.  It is necessary,
133	 * now that we're doing dynamic initialization here, that we preserve
134	 * the old semantics: if an application modifies one of these three
135	 * fields of _res before res_init() is called, res_init() will not
136	 * alter them.  Of course, if an application is setting them to
137	 * _zero_ before calling res_init(), hoping to override what used
138	 * to be the static default, we can't detect it and unexpected results
139	 * will follow.  Zero for any of these fields would make no sense,
140	 * so one can safely assume that the applications were already getting
141	 * unexpected results.
142	 *
143	 * _nres.options is tricky since some apps were known to diddle the bits
144	 * before res_init() was first called. We can't replicate that semantic
145	 * with dynamic initialization (they may have turned bits off that are
146	 * set in RES_DEFAULT).  Our solution is to declare such applications
147	 * "broken".  They could fool us by setting RES_INIT but none do (yet).
148	 */
149	if (!_nres.retrans)
150		_nres.retrans = RES_TIMEOUT;
151	if (!_nres.retry)
152		_nres.retry = 4;
153	if (!(_nres.options & RES_INIT))
154		_nres.options = RES_DEFAULT;
155
156	/*
157	 * This one used to initialize implicitly to zero, so unless the app
158	 * has set it to something in particular, we can randomize it now.
159	 */
160	if (!_nres.id)
161		_nres.id = res_nrandomid(&_nres);
162
163	rv = __res_vinit(&_nres, 1);
164#ifdef COMPAT__RES
165	__res_put_old_state(&_nres);
166#endif
167	return rv;
168}
169
170void
171p_query(const u_char *msg) {
172	fp_query(msg, stdout);
173}
174
175void
176fp_query(const u_char *msg, FILE *file) {
177	fp_nquery(msg, PACKETSZ, file);
178}
179
180void
181fp_nquery(const u_char *msg, int len, FILE *file) {
182	if ((_nres.options & RES_INIT) == 0U && res_init() == -1)
183		return;
184
185	res_pquery(&_nres, msg, len, file);
186}
187
188int
189res_mkquery(int op,			/*!< opcode of query  */
190	    const char *dname,		/*!< domain name  */
191	    int class, int type,	/*!< class and type of query  */
192	    const u_char *data,		/*!< resource record data  */
193	    int datalen,		/*!< length of data  */
194	    const u_char *newrr_in,	/*!< new rr for modify or append  */
195	    u_char *buf,		/*!< buffer to put query  */
196	    int buflen)			/*!< size of buffer  */
197{
198	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
199		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
200		return (-1);
201	}
202	return (res_nmkquery(&_nres, op, dname, class, type,
203			     data, datalen,
204			     newrr_in, buf, buflen));
205}
206
207#ifdef _LIBRESOLV
208int
209res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
210	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
211		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
212		return (-1);
213	}
214
215	return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
216}
217#endif
218
219int
220res_query(const char *name,	/*!< domain name  */
221	  int class, int type,	/*!< class and type of query  */
222	  u_char *answer,	/*!< buffer to put answer  */
223	  int anslen)		/*!< size of answer buffer  */
224{
225	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
226		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
227		return (-1);
228	}
229	return (res_nquery(&_nres, name, class, type, answer, anslen));
230}
231
232void
233res_send_setqhook(res_send_qhook hook) {
234	_nres.qhook = hook;
235}
236
237void
238res_send_setrhook(res_send_rhook hook) {
239	_nres.rhook = hook;
240}
241
242int
243res_isourserver(const struct sockaddr_in *inp) {
244	return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
245}
246
247int
248res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
249	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
250		/* errno should have been set by res_init() in this case. */
251		return (-1);
252	}
253
254	return (res_nsend(&_nres, buf, buflen, ans, anssiz));
255}
256
257#ifdef _LIBRESOLV
258int
259res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
260	       u_char *ans, int anssiz)
261{
262	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
263		/* errno should have been set by res_init() in this case. */
264		return (-1);
265	}
266
267	return (res_nsendsigned(&_nres, buf, buflen, key, ans, anssiz));
268}
269#endif
270
271void
272res_close(void) {
273	res_nclose(&_nres);
274}
275
276#ifdef _LIBRESOLV
277int
278res_update(ns_updrec *rrecp_in) {
279	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
280		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
281		return (-1);
282	}
283
284	return (res_nupdate(&_nres, rrecp_in, NULL));
285}
286#endif
287
288int
289res_search(const char *name,	/*!< domain name  */
290	   int class, int type,	/*!< class and type of query  */
291	   u_char *answer,	/*!< buffer to put answer  */
292	   int anslen)		/*!< size of answer  */
293{
294	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
295		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
296		return (-1);
297	}
298
299	return (res_nsearch(&_nres, name, class, type, answer, anslen));
300}
301
302int
303res_querydomain(const char *name,
304		const char *domain,
305		int class, int type,	/*!< class and type of query  */
306		u_char *answer,		/*!< buffer to put answer  */
307		int anslen)		/*!< size of answer  */
308{
309	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
310		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
311		return (-1);
312	}
313
314	return (res_nquerydomain(&_nres, name, domain,
315				 class, type,
316				 answer, anslen));
317}
318
319int
320res_opt(int a, u_char *b, int c, int d)
321{
322	return res_nopt(&_nres, a, b, c, d);
323}
324
325u_int
326res_randomid(void) {
327	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
328		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
329		return (u_int)-1;
330	}
331
332	return (res_nrandomid(&_nres));
333}
334
335const char *
336hostalias(const char *name) {
337	static char abuf[MAXDNAME];
338
339	return (res_hostalias(&_nres, name, abuf, sizeof abuf));
340}
341
342#ifdef ultrix
343int
344local_hostname_length(const char *hostname) {
345	int len_host, len_domain;
346
347	if (!*_nres.defdname)
348		res_init();
349	len_host = strlen(hostname);
350	len_domain = strlen(_nres.defdname);
351	if (len_host > len_domain &&
352	    !strcasecmp(hostname + len_host - len_domain, _nres.defdname) &&
353	    hostname[len_host - len_domain - 1] == '.')
354		return (len_host - len_domain - 1);
355	return (0);
356}
357#endif /*ultrix*/
358
359#endif
360
361/*! \file */
362