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
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 1.14 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
74const 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
94const char *_res_sectioncodes[] = {
95	"ZONE",
96	"PREREQUISITES",
97	"UPDATE",
98	"ADDITIONAL",
99};
100#endif
101
102#ifndef __BIND_NOSTATIC
103extern struct __res_state _nres;
104
105/* Proto. */
106
107int  res_ourserver_p(const res_state, const struct sockaddr *);
108
109int
110res_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
171void
172p_query(const u_char *msg) {
173	fp_query(msg, stdout);
174}
175
176void
177fp_query(const u_char *msg, FILE *file) {
178	fp_nquery(msg, PACKETSZ, file);
179}
180
181void
182fp_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
189int
190res_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
209int
210res_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
220int
221res_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
233void
234res_send_setqhook(res_send_qhook hook) {
235	_nres.qhook = hook;
236}
237
238void
239res_send_setrhook(res_send_rhook hook) {
240	_nres.rhook = hook;
241}
242
243int
244res_isourserver(const struct sockaddr_in *inp) {
245	return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
246}
247
248int
249res_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
259int
260res_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
272void
273res_close(void) {
274	res_nclose(&_nres);
275}
276
277#ifdef _LIBRESOLV
278int
279res_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
289int
290res_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
303int
304res_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
320int
321res_opt(int a, u_char *b, int c, int d)
322{
323	return res_nopt(&_nres, a, b, c, d);
324}
325
326u_int
327res_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
336const char *
337hostalias(const char *name) {
338	static char abuf[MAXDNAME];
339
340	return (res_hostalias(&_nres, name, abuf, sizeof abuf));
341}
342
343#ifdef ultrix
344int
345local_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