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)
19static const char rcsid[] = "$Id: res_data.c,v 1.7 2008/12/11 09:59:00 marka Exp $";
20#endif /* LIBC_SCCS and not lint */
21
22#include "port_before.h"
23
24#include <sys/types.h>
25#include <sys/param.h>
26#include <sys/socket.h>
27#include <sys/time.h>
28
29#include <netinet/in.h>
30#include <arpa/inet.h>
31#include <arpa/nameser.h>
32
33#include <ctype.h>
34#include <netdb.h>
35#include <resolv.h>
36#include <res_update.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include <unistd.h>
41
42#include "port_after.h"
43
44const char *_res_opcodes[] = {
45	"QUERY",
46	"IQUERY",
47	"CQUERYM",
48	"CQUERYU",	/*%< experimental */
49	"NOTIFY",	/*%< experimental */
50	"UPDATE",
51	"6",
52	"7",
53	"8",
54	"9",
55	"10",
56	"11",
57	"12",
58	"13",
59	"ZONEINIT",
60	"ZONEREF",
61};
62
63#ifdef BIND_UPDATE
64const char *_res_sectioncodes[] = {
65	"ZONE",
66	"PREREQUISITES",
67	"UPDATE",
68	"ADDITIONAL",
69};
70#endif
71
72#undef _res
73#ifndef __BIND_NOSTATIC
74struct __res_state _res
75# if defined(__BIND_RES_TEXT)
76	= { RES_TIMEOUT, }	/*%< Motorola, et al. */
77# endif
78        ;
79
80#if defined(DO_PTHREADS) || defined(__linux)
81#define _res (*__res_state())
82#endif
83
84/* Proto. */
85
86int  res_ourserver_p(const res_state, const struct sockaddr_in *);
87
88int
89res_init(void) {
90	extern int __res_vinit(res_state, int);
91
92	/*
93	 * These three fields used to be statically initialized.  This made
94	 * it hard to use this code in a shared library.  It is necessary,
95	 * now that we're doing dynamic initialization here, that we preserve
96	 * the old semantics: if an application modifies one of these three
97	 * fields of _res before res_init() is called, res_init() will not
98	 * alter them.  Of course, if an application is setting them to
99	 * _zero_ before calling res_init(), hoping to override what used
100	 * to be the static default, we can't detect it and unexpected results
101	 * will follow.  Zero for any of these fields would make no sense,
102	 * so one can safely assume that the applications were already getting
103	 * unexpected results.
104	 *
105	 * _res.options is tricky since some apps were known to diddle the bits
106	 * before res_init() was first called. We can't replicate that semantic
107	 * with dynamic initialization (they may have turned bits off that are
108	 * set in RES_DEFAULT).  Our solution is to declare such applications
109	 * "broken".  They could fool us by setting RES_INIT but none do (yet).
110	 */
111	if (!_res.retrans)
112		_res.retrans = RES_TIMEOUT;
113	if (!_res.retry)
114		_res.retry = 4;
115	if (!(_res.options & RES_INIT))
116		_res.options = RES_DEFAULT;
117
118	/*
119	 * This one used to initialize implicitly to zero, so unless the app
120	 * has set it to something in particular, we can randomize it now.
121	 */
122	if (!_res.id)
123		_res.id = res_nrandomid(&_res);
124
125	return (__res_vinit(&_res, 1));
126}
127
128void
129p_query(const u_char *msg) {
130	fp_query(msg, stdout);
131}
132
133void
134fp_query(const u_char *msg, FILE *file) {
135	fp_nquery(msg, PACKETSZ, file);
136}
137
138void
139fp_nquery(const u_char *msg, int len, FILE *file) {
140	if ((_res.options & RES_INIT) == 0U && res_init() == -1)
141		return;
142
143	res_pquery(&_res, msg, len, file);
144}
145
146int
147res_mkquery(int op,			/*!< opcode of query  */
148	    const char *dname,		/*!< domain name  */
149	    int class, int type,	/*!< class and type of query  */
150	    const u_char *data,		/*!< resource record data  */
151	    int datalen,		/*!< length of data  */
152	    const u_char *newrr_in,	/*!< new rr for modify or append  */
153	    u_char *buf,		/*!< buffer to put query  */
154	    int buflen)			/*!< size of buffer  */
155{
156	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
157		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
158		return (-1);
159	}
160	return (res_nmkquery(&_res, op, dname, class, type,
161			     data, datalen,
162			     newrr_in, buf, buflen));
163}
164
165int
166res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
167	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
168		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
169		return (-1);
170	}
171
172	return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
173}
174
175int
176res_query(const char *name,	/*!< domain name  */
177	  int class, int type,	/*!< class and type of query  */
178	  u_char *answer,	/*!< buffer to put answer  */
179	  int anslen)		/*!< size of answer buffer  */
180{
181	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
182		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
183		return (-1);
184	}
185	return (res_nquery(&_res, name, class, type, answer, anslen));
186}
187
188void
189res_send_setqhook(res_send_qhook hook) {
190	_res.qhook = hook;
191}
192
193void
194res_send_setrhook(res_send_rhook hook) {
195	_res.rhook = hook;
196}
197
198int
199res_isourserver(const struct sockaddr_in *inp) {
200	return (res_ourserver_p(&_res, inp));
201}
202
203int
204res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
205	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
206		/* errno should have been set by res_init() in this case. */
207		return (-1);
208	}
209
210	return (res_nsend(&_res, buf, buflen, ans, anssiz));
211}
212
213int
214res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
215	       u_char *ans, int anssiz)
216{
217	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
218		/* errno should have been set by res_init() in this case. */
219		return (-1);
220	}
221
222	return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
223}
224
225void
226res_close(void) {
227	res_nclose(&_res);
228}
229
230int
231res_update(ns_updrec *rrecp_in) {
232	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
233		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
234		return (-1);
235	}
236
237	return (res_nupdate(&_res, rrecp_in, NULL));
238}
239
240int
241res_search(const char *name,	/*!< domain name  */
242	   int class, int type,	/*!< class and type of query  */
243	   u_char *answer,	/*!< buffer to put answer  */
244	   int anslen)		/*!< size of answer  */
245{
246	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
247		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
248		return (-1);
249	}
250
251	return (res_nsearch(&_res, name, class, type, answer, anslen));
252}
253
254int
255res_querydomain(const char *name,
256		const char *domain,
257		int class, int type,	/*!< class and type of query  */
258		u_char *answer,		/*!< buffer to put answer  */
259		int anslen)		/*!< size of answer  */
260{
261	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
262		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
263		return (-1);
264	}
265
266	return (res_nquerydomain(&_res, name, domain,
267				 class, type,
268				 answer, anslen));
269}
270
271u_int
272res_randomid(void) {
273	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
274		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
275		return (-1);
276	}
277
278	return (res_nrandomid(&_res));
279}
280
281const char *
282hostalias(const char *name) {
283	static char abuf[MAXDNAME];
284
285	return (res_hostalias(&_res, name, abuf, sizeof abuf));
286}
287
288#ifdef ultrix
289int
290local_hostname_length(const char *hostname) {
291	int len_host, len_domain;
292
293	if (!*_res.defdname)
294		res_init();
295	len_host = strlen(hostname);
296	len_domain = strlen(_res.defdname);
297	if (len_host > len_domain &&
298	    !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
299	    hostname[len_host - len_domain - 1] == '.')
300		return (len_host - len_domain - 1);
301	return (0);
302}
303#endif /*ultrix*/
304
305#endif
306
307/*! \file */
308