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
23static 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__
50const 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
70const char * const _res_sectioncodes[] = {
71	"ZONE",
72	"PREREQUISITES",
73	"UPDATE",
74	"ADDITIONAL",
75};
76#endif
77
78#ifndef __BIND_NOSTATIC
79extern struct __res_state _nres;
80
81/* Proto. */
82
83int  res_ourserver_p(const res_state, const struct sockaddr *);
84
85#ifdef ANDROID_CHANGES
86static 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
93int
94res_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
156void
157p_query(const u_char *msg) {
158	fp_query(msg, stdout);
159}
160
161void
162fp_query(const u_char *msg, FILE *file) {
163	fp_nquery(msg, PACKETSZ, file);
164}
165
166void
167fp_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
174int
175res_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
194int
195res_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
205int
206res_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
218void
219res_send_setqhook(res_send_qhook hook) {
220	_nres.qhook = hook;
221}
222
223void
224res_send_setrhook(res_send_rhook hook) {
225	_nres.rhook = hook;
226}
227
228int
229res_isourserver(const struct sockaddr_in *inp) {
230	return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
231}
232
233int
234res_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
244int
245res_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
257void
258res_close(void) {
259	res_nclose(&_nres);
260}
261
262#ifdef _LIBRESOLV
263int
264res_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
274int
275res_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
288int
289res_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
305int
306res_opt(int a, u_char *b, int c, int d)
307{
308	return res_nopt(&_nres, a, b, c, d);
309}
310
311const char *
312hostalias(const char *name) {
313	return NULL;
314}
315
316#ifdef ultrix
317int
318local_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