res_data.c revision 156956 
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 1.1.206.2 2004/03/16 12:34:18 marka Exp $";
20#endif /* LIBC_SCCS and not lint */
21#include <sys/cdefs.h>
22__FBSDID("$FreeBSD: head/lib/libc/resolv/res_data.c 156956 2006-03-21 15:37:16Z 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#ifndef _LIBC
39#include <res_update.h>
40#endif
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <unistd.h>
45
46#include "port_after.h"
47
48const char *_res_opcodes[] = {
49	"QUERY",
50	"IQUERY",
51	"CQUERYM",
52	"CQUERYU",	/* experimental */
53	"NOTIFY",	/* experimental */
54	"UPDATE",
55	"6",
56	"7",
57	"8",
58	"9",
59	"10",
60	"11",
61	"12",
62	"13",
63	"ZONEINIT",
64	"ZONEREF",
65};
66
67#ifdef BIND_UPDATE
68const char *_res_sectioncodes[] = {
69	"ZONE",
70	"PREREQUISITES",
71	"UPDATE",
72	"ADDITIONAL",
73};
74#endif
75
76#ifndef __BIND_NOSTATIC
77
78/* Proto. */
79
80int  res_ourserver_p(const res_state, const struct sockaddr_in *);
81
82int
83res_init(void) {
84	extern int __res_vinit(res_state, int);
85
86	/*
87	 * These three fields used to be statically initialized.  This made
88	 * it hard to use this code in a shared library.  It is necessary,
89	 * now that we're doing dynamic initialization here, that we preserve
90	 * the old semantics: if an application modifies one of these three
91	 * fields of _res before res_init() is called, res_init() will not
92	 * alter them.  Of course, if an application is setting them to
93	 * _zero_ before calling res_init(), hoping to override what used
94	 * to be the static default, we can't detect it and unexpected results
95	 * will follow.  Zero for any of these fields would make no sense,
96	 * so one can safely assume that the applications were already getting
97	 * unexpected results.
98	 *
99	 * _res.options is tricky since some apps were known to diddle the bits
100	 * before res_init() was first called. We can't replicate that semantic
101	 * with dynamic initialization (they may have turned bits off that are
102	 * set in RES_DEFAULT).  Our solution is to declare such applications
103	 * "broken".  They could fool us by setting RES_INIT but none do (yet).
104	 */
105	if (!_res.retrans)
106		_res.retrans = RES_TIMEOUT;
107	if (!_res.retry)
108		_res.retry = RES_DFLRETRY;
109	if (!(_res.options & RES_INIT))
110		_res.options = RES_DEFAULT;
111
112	/*
113	 * This one used to initialize implicitly to zero, so unless the app
114	 * has set it to something in particular, we can randomize it now.
115	 */
116	if (!_res.id)
117		_res.id = res_randomid();
118
119	return (__res_vinit(&_res, 1));
120}
121
122void
123p_query(const u_char *msg) {
124	fp_query(msg, stdout);
125}
126
127void
128fp_query(const u_char *msg, FILE *file) {
129	fp_nquery(msg, PACKETSZ, file);
130}
131
132void
133fp_nquery(const u_char *msg, int len, FILE *file) {
134	if ((_res.options & RES_INIT) == 0U && res_init() == -1)
135		return;
136
137	res_pquery(&_res, msg, len, file);
138}
139
140int
141res_mkquery(int op,			/* opcode of query */
142	    const char *dname,		/* domain name */
143	    int class, int type,	/* class and type of query */
144	    const u_char *data,		/* resource record data */
145	    int datalen,		/* length of data */
146	    const u_char *newrr_in,	/* new rr for modify or append */
147	    u_char *buf,		/* buffer to put query */
148	    int buflen)			/* size of buffer */
149{
150	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
151		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
152		return (-1);
153	}
154	return (res_nmkquery(&_res, op, dname, class, type,
155			     data, datalen,
156			     newrr_in, buf, buflen));
157}
158
159#ifndef _LIBC
160int
161res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
162	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
163		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
164		return (-1);
165	}
166
167	return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
168}
169#endif
170
171int
172res_query(const char *name,	/* domain name */
173	  int class, int type,	/* class and type of query */
174	  u_char *answer,	/* buffer to put answer */
175	  int anslen)		/* size of answer buffer */
176{
177	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
178		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
179		return (-1);
180	}
181	return (res_nquery(&_res, name, class, type, answer, anslen));
182}
183
184#ifndef _LIBC
185void
186res_send_setqhook(res_send_qhook hook) {
187	_res.qhook = hook;
188}
189
190void
191res_send_setrhook(res_send_rhook hook) {
192	_res.rhook = hook;
193}
194#endif
195
196int
197res_isourserver(const struct sockaddr_in *inp) {
198	return (res_ourserver_p(&_res, inp));
199}
200
201int
202res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
203	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
204		/* errno should have been set by res_init() in this case. */
205		return (-1);
206	}
207
208	return (res_nsend(&_res, buf, buflen, ans, anssiz));
209}
210
211#ifndef _LIBC
212int
213res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
214	       u_char *ans, int anssiz)
215{
216	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
217		/* errno should have been set by res_init() in this case. */
218		return (-1);
219	}
220
221	return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
222}
223#endif
224
225void
226res_close(void) {
227	res_nclose(&_res);
228}
229
230#ifndef _LIBC
231int
232res_update(ns_updrec *rrecp_in) {
233	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
234		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
235		return (-1);
236	}
237
238	return (res_nupdate(&_res, rrecp_in, NULL));
239}
240#endif
241
242int
243res_search(const char *name,	/* domain name */
244	   int class, int type,	/* class and type of query */
245	   u_char *answer,	/* buffer to put answer */
246	   int anslen)		/* size of answer */
247{
248	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
249		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
250		return (-1);
251	}
252
253	return (res_nsearch(&_res, name, class, type, answer, anslen));
254}
255
256int
257res_querydomain(const char *name,
258		const char *domain,
259		int class, int type,	/* class and type of query */
260		u_char *answer,		/* buffer to put answer */
261		int anslen)		/* size of answer */
262{
263	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
264		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
265		return (-1);
266	}
267
268	return (res_nquerydomain(&_res, name, domain,
269				 class, type,
270				 answer, anslen));
271}
272
273int
274res_opt(int n0, u_char *buf, int buflen, int anslen)
275{
276	return (res_nopt(&_res, n0, buf, buflen, anslen));
277}
278
279const char *
280hostalias(const char *name) {
281	static char abuf[MAXDNAME];
282
283	return (res_hostalias(&_res, name, abuf, sizeof abuf));
284}
285
286#ifdef ultrix
287int
288local_hostname_length(const char *hostname) {
289	int len_host, len_domain;
290
291	if (!*_res.defdname)
292		res_init();
293	len_host = strlen(hostname);
294	len_domain = strlen(_res.defdname);
295	if (len_host > len_domain &&
296	    !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
297	    hostname[len_host - len_domain - 1] == '.')
298		return (len_host - len_domain - 1);
299	return (0);
300}
301#endif /*ultrix*/
302
303/*
304 * Weak aliases for applications that use certain private entry points,
305 * and fail to include <resolv.h>.
306 */
307#undef res_init
308__weak_reference(__res_init, res_init);
309#undef p_query
310__weak_reference(__p_query, p_query);
311#undef res_mkquery
312__weak_reference(__res_mkquery, res_mkquery);
313#undef res_query
314__weak_reference(__res_query, res_query);
315#undef res_send
316__weak_reference(__res_send, res_send);
317#undef res_close
318__weak_reference(__res_close, _res_close);
319#undef res_search
320__weak_reference(__res_search, res_search);
321#undef res_querydomain
322__weak_reference(__res_querydomain, res_querydomain);
323
324#endif
325