res_data.c revision 270838 
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 $";
20#endif /* LIBC_SCCS and not lint */
21#include <sys/cdefs.h>
22__FBSDID("$FreeBSD: stable/10/lib/libc/resolv/res_data.c 270838 2014-08-30 10:16:25Z ume $");
23
24#include "port_before.h"
25
26#include <sys/types.h>
27#include <sys/param.h>
28#include <sys/socket.h>
29#include <sys/time.h>
30
31#include <netinet/in.h>
32#include <arpa/inet.h>
33#include <arpa/nameser.h>
34
35#include <ctype.h>
36#include <netdb.h>
37#include <resolv.h>
38#include <res_update.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43
44#include "port_after.h"
45
46const char *_res_opcodes[] = {
47	"QUERY",
48	"IQUERY",
49	"CQUERYM",
50	"CQUERYU",	/*%< experimental */
51	"NOTIFY",	/*%< experimental */
52	"UPDATE",
53	"6",
54	"7",
55	"8",
56	"9",
57	"10",
58	"11",
59	"12",
60	"13",
61	"ZONEINIT",
62	"ZONEREF",
63};
64
65#ifdef BIND_UPDATE
66const char *_res_sectioncodes[] = {
67	"ZONE",
68	"PREREQUISITES",
69	"UPDATE",
70	"ADDITIONAL",
71};
72#endif
73
74#ifndef __BIND_NOSTATIC
75
76/* Proto. */
77
78int  res_ourserver_p(const res_state, const struct sockaddr_in *);
79
80int
81res_init(void) {
82	extern int __res_vinit(res_state, int);
83
84	/*
85	 * These three fields used to be statically initialized.  This made
86	 * it hard to use this code in a shared library.  It is necessary,
87	 * now that we're doing dynamic initialization here, that we preserve
88	 * the old semantics: if an application modifies one of these three
89	 * fields of _res before res_init() is called, res_init() will not
90	 * alter them.  Of course, if an application is setting them to
91	 * _zero_ before calling res_init(), hoping to override what used
92	 * to be the static default, we can't detect it and unexpected results
93	 * will follow.  Zero for any of these fields would make no sense,
94	 * so one can safely assume that the applications were already getting
95	 * unexpected results.
96	 *
97	 * _res.options is tricky since some apps were known to diddle the bits
98	 * before res_init() was first called. We can't replicate that semantic
99	 * with dynamic initialization (they may have turned bits off that are
100	 * set in RES_DEFAULT).  Our solution is to declare such applications
101	 * "broken".  They could fool us by setting RES_INIT but none do (yet).
102	 */
103	if (!_res.retrans)
104		_res.retrans = RES_TIMEOUT;
105	if (!_res.retry)
106		_res.retry = RES_DFLRETRY;
107	if (!(_res.options & RES_INIT))
108		_res.options = RES_DEFAULT;
109
110	return (__res_vinit(&_res, 1));
111}
112
113void
114p_query(const u_char *msg) {
115	fp_query(msg, stdout);
116}
117
118void
119fp_query(const u_char *msg, FILE *file) {
120	fp_nquery(msg, PACKETSZ, file);
121}
122
123void
124fp_nquery(const u_char *msg, int len, FILE *file) {
125	if ((_res.options & RES_INIT) == 0U && res_init() == -1)
126		return;
127
128	res_pquery(&_res, msg, len, file);
129}
130
131int
132res_mkquery(int op,			/*!< opcode of query  */
133	    const char *dname,		/*!< domain name  */
134	    int class, int type,	/*!< class and type of query  */
135	    const u_char *data,		/*!< resource record data  */
136	    int datalen,		/*!< length of data  */
137	    const u_char *newrr_in,	/*!< new rr for modify or append  */
138	    u_char *buf,		/*!< buffer to put query  */
139	    int buflen)			/*!< size of buffer  */
140{
141	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
142		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
143		return (-1);
144	}
145	return (res_nmkquery(&_res, op, dname, class, type,
146			     data, datalen,
147			     newrr_in, buf, buflen));
148}
149
150int
151res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
152	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
153		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
154		return (-1);
155	}
156
157	return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
158}
159
160int
161res_query(const char *name,	/*!< domain name  */
162	  int class, int type,	/*!< class and type of query  */
163	  u_char *answer,	/*!< buffer to put answer  */
164	  int anslen)		/*!< size of answer buffer  */
165{
166	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
167		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
168		return (-1);
169	}
170	return (res_nquery(&_res, name, class, type, answer, anslen));
171}
172
173#ifndef _LIBC
174void
175res_send_setqhook(res_send_qhook hook) {
176	_res.qhook = hook;
177}
178
179void
180res_send_setrhook(res_send_rhook hook) {
181	_res.rhook = hook;
182}
183#endif
184
185int
186res_isourserver(const struct sockaddr_in *inp) {
187	return (res_ourserver_p(&_res, inp));
188}
189
190int
191res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
192	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
193		/* errno should have been set by res_init() in this case. */
194		return (-1);
195	}
196
197	return (res_nsend(&_res, buf, buflen, ans, anssiz));
198}
199
200#ifndef _LIBC
201int
202res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
203	       u_char *ans, int anssiz)
204{
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_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
211}
212#endif
213
214void
215res_close(void) {
216	res_nclose(&_res);
217}
218
219int
220res_update(ns_updrec *rrecp_in) {
221	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
222		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
223		return (-1);
224	}
225
226	return (res_nupdate(&_res, rrecp_in, NULL));
227}
228
229int
230res_search(const char *name,	/*!< domain name  */
231	   int class, int type,	/*!< class and type of query  */
232	   u_char *answer,	/*!< buffer to put answer  */
233	   int anslen)		/*!< size of answer  */
234{
235	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
236		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
237		return (-1);
238	}
239
240	return (res_nsearch(&_res, name, class, type, answer, anslen));
241}
242
243int
244res_querydomain(const char *name,
245		const char *domain,
246		int class, int type,	/*!< class and type of query  */
247		u_char *answer,		/*!< buffer to put answer  */
248		int anslen)		/*!< size of answer  */
249{
250	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
251		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
252		return (-1);
253	}
254
255	return (res_nquerydomain(&_res, name, domain,
256				 class, type,
257				 answer, anslen));
258}
259
260u_int
261res_randomid(void) {
262	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
263		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
264		return (-1);
265	}
266
267	return (res_nrandomid(&_res));
268}
269
270int
271res_opt(int n0, u_char *buf, int buflen, int anslen)
272{
273	return (res_nopt(&_res, n0, buf, buflen, anslen));
274}
275
276const char *
277hostalias(const char *name) {
278	static char abuf[MAXDNAME];
279
280	return (res_hostalias(&_res, name, abuf, sizeof abuf));
281}
282
283#ifdef ultrix
284int
285local_hostname_length(const char *hostname) {
286	int len_host, len_domain;
287
288	if (!*_res.defdname)
289		res_init();
290	len_host = strlen(hostname);
291	len_domain = strlen(_res.defdname);
292	if (len_host > len_domain &&
293	    !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
294	    hostname[len_host - len_domain - 1] == '.')
295		return (len_host - len_domain - 1);
296	return (0);
297}
298#endif /*ultrix*/
299
300/*
301 * Weak aliases for applications that use certain private entry points,
302 * and fail to include <resolv.h>.
303 */
304#undef res_init
305__weak_reference(__res_init, res_init);
306#undef p_query
307__weak_reference(__p_query, p_query);
308#undef res_mkquery
309__weak_reference(__res_mkquery, res_mkquery);
310#undef res_query
311__weak_reference(__res_query, res_query);
312#undef res_send
313__weak_reference(__res_send, res_send);
314#undef res_close
315__weak_reference(__res_close, _res_close);
316#undef res_search
317__weak_reference(__res_search, res_search);
318#undef res_querydomain
319__weak_reference(__res_querydomain, res_querydomain);
320
321#endif
322
323/*! \file */
324