1/*	$NetBSD: res_data.c,v 1.13 2009/04/12 19:43:37 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 1.13 2009/04/12 19:43:37 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	extern void *__res_get_old_state(void);
121	extern void __res_put_old_state(void *);
122	res_state ores = __res_get_old_state();
123
124	if (ores->options != 0)
125		_nres.options = ores->options;
126	if (ores->retrans != 0)
127		_nres.retrans = ores->retrans;
128	if (ores->retry != 0)
129		_nres.retry = ores->retry;
130#endif
131
132	/*
133	 * These three fields used to be statically initialized.  This made
134	 * it hard to use this code in a shared library.  It is necessary,
135	 * now that we're doing dynamic initialization here, that we preserve
136	 * the old semantics: if an application modifies one of these three
137	 * fields of _res before res_init() is called, res_init() will not
138	 * alter them.  Of course, if an application is setting them to
139	 * _zero_ before calling res_init(), hoping to override what used
140	 * to be the static default, we can't detect it and unexpected results
141	 * will follow.  Zero for any of these fields would make no sense,
142	 * so one can safely assume that the applications were already getting
143	 * unexpected results.
144	 *
145	 * _nres.options is tricky since some apps were known to diddle the bits
146	 * before res_init() was first called. We can't replicate that semantic
147	 * with dynamic initialization (they may have turned bits off that are
148	 * set in RES_DEFAULT).  Our solution is to declare such applications
149	 * "broken".  They could fool us by setting RES_INIT but none do (yet).
150	 */
151	if (!_nres.retrans)
152		_nres.retrans = RES_TIMEOUT;
153	if (!_nres.retry)
154		_nres.retry = 4;
155	if (!(_nres.options & RES_INIT))
156		_nres.options = RES_DEFAULT;
157
158	/*
159	 * This one used to initialize implicitly to zero, so unless the app
160	 * has set it to something in particular, we can randomize it now.
161	 */
162	if (!_nres.id)
163		_nres.id = res_nrandomid(&_nres);
164
165	rv = __res_vinit(&_nres, 1);
166#ifdef COMPAT__RES
167	__res_put_old_state(&_nres);
168#endif
169	return rv;
170}
171
172void
173p_query(const u_char *msg) {
174	fp_query(msg, stdout);
175}
176
177void
178fp_query(const u_char *msg, FILE *file) {
179	fp_nquery(msg, PACKETSZ, file);
180}
181
182void
183fp_nquery(const u_char *msg, int len, FILE *file) {
184	if ((_nres.options & RES_INIT) == 0U && res_init() == -1)
185		return;
186
187	res_pquery(&_nres, msg, len, file);
188}
189
190int
191res_mkquery(int op,			/*!< opcode of query  */
192	    const char *dname,		/*!< domain name  */
193	    int class, int type,	/*!< class and type of query  */
194	    const u_char *data,		/*!< resource record data  */
195	    int datalen,		/*!< length of data  */
196	    const u_char *newrr_in,	/*!< new rr for modify or append  */
197	    u_char *buf,		/*!< buffer to put query  */
198	    int buflen)			/*!< size of buffer  */
199{
200	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
201		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
202		return (-1);
203	}
204	return (res_nmkquery(&_nres, op, dname, class, type,
205			     data, datalen,
206			     newrr_in, buf, buflen));
207}
208
209#ifdef _LIBRESOLV
210int
211res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
212	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
213		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
214		return (-1);
215	}
216
217	return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
218}
219#endif
220
221int
222res_query(const char *name,	/*!< domain name  */
223	  int class, int type,	/*!< class and type of query  */
224	  u_char *answer,	/*!< buffer to put answer  */
225	  int anslen)		/*!< size of answer buffer  */
226{
227	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
228		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
229		return (-1);
230	}
231	return (res_nquery(&_nres, name, class, type, answer, anslen));
232}
233
234void
235res_send_setqhook(res_send_qhook hook) {
236	_nres.qhook = hook;
237}
238
239void
240res_send_setrhook(res_send_rhook hook) {
241	_nres.rhook = hook;
242}
243
244int
245res_isourserver(const struct sockaddr_in *inp) {
246	return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
247}
248
249int
250res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
251	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
252		/* errno should have been set by res_init() in this case. */
253		return (-1);
254	}
255
256	return (res_nsend(&_nres, buf, buflen, ans, anssiz));
257}
258
259#ifdef _LIBRESOLV
260int
261res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
262	       u_char *ans, int anssiz)
263{
264	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
265		/* errno should have been set by res_init() in this case. */
266		return (-1);
267	}
268
269	return (res_nsendsigned(&_nres, buf, buflen, key, ans, anssiz));
270}
271#endif
272
273void
274res_close(void) {
275	res_nclose(&_nres);
276}
277
278#ifdef _LIBRESOLV
279int
280res_update(ns_updrec *rrecp_in) {
281	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
282		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
283		return (-1);
284	}
285
286	return (res_nupdate(&_nres, rrecp_in, NULL));
287}
288#endif
289
290int
291res_search(const char *name,	/*!< domain name  */
292	   int class, int type,	/*!< class and type of query  */
293	   u_char *answer,	/*!< buffer to put answer  */
294	   int anslen)		/*!< size of answer  */
295{
296	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
297		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
298		return (-1);
299	}
300
301	return (res_nsearch(&_nres, name, class, type, answer, anslen));
302}
303
304int
305res_querydomain(const char *name,
306		const char *domain,
307		int class, int type,	/*!< class and type of query  */
308		u_char *answer,		/*!< buffer to put answer  */
309		int anslen)		/*!< size of answer  */
310{
311	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
312		RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
313		return (-1);
314	}
315
316	return (res_nquerydomain(&_nres, name, domain,
317				 class, type,
318				 answer, anslen));
319}
320
321int
322res_opt(int a, u_char *b, int c, int d)
323{
324	return res_nopt(&_nres, a, b, c, d);
325}
326
327u_int
328res_randomid(void) {
329	if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
330		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
331		return (u_int)-1;
332	}
333
334	return (res_nrandomid(&_nres));
335}
336
337const char *
338hostalias(const char *name) {
339	static char abuf[MAXDNAME];
340
341	return (res_hostalias(&_nres, name, abuf, sizeof abuf));
342}
343
344#ifdef ultrix
345int
346local_hostname_length(const char *hostname) {
347	int len_host, len_domain;
348
349	if (!*_nres.defdname)
350		res_init();
351	len_host = strlen(hostname);
352	len_domain = strlen(_nres.defdname);
353	if (len_host > len_domain &&
354	    !strcasecmp(hostname + len_host - len_domain, _nres.defdname) &&
355	    hostname[len_host - len_domain - 1] == '.')
356		return (len_host - len_domain - 1);
357	return (0);
358}
359#endif /*ultrix*/
360
361#endif
362
363/*! \file */
364