res_data.c revision 157308 
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 157308 2006-03-30 20:15:53Z 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	/*
111	 * This one used to initialize implicitly to zero, so unless the app
112	 * has set it to something in particular, we can randomize it now.
113	 */
114	if (!_res.id)
115		_res.id = res_randomid();
116
117	return (__res_vinit(&_res, 1));
118}
119
120void
121p_query(const u_char *msg) {
122	fp_query(msg, stdout);
123}
124
125void
126fp_query(const u_char *msg, FILE *file) {
127	fp_nquery(msg, PACKETSZ, file);
128}
129
130void
131fp_nquery(const u_char *msg, int len, FILE *file) {
132	if ((_res.options & RES_INIT) == 0U && res_init() == -1)
133		return;
134
135	res_pquery(&_res, msg, len, file);
136}
137
138int
139res_mkquery(int op,			/* opcode of query */
140	    const char *dname,		/* domain name */
141	    int class, int type,	/* class and type of query */
142	    const u_char *data,		/* resource record data */
143	    int datalen,		/* length of data */
144	    const u_char *newrr_in,	/* new rr for modify or append */
145	    u_char *buf,		/* buffer to put query */
146	    int buflen)			/* size of buffer */
147{
148	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
149		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
150		return (-1);
151	}
152	return (res_nmkquery(&_res, op, dname, class, type,
153			     data, datalen,
154			     newrr_in, buf, buflen));
155}
156
157int
158res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
159	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
160		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
161		return (-1);
162	}
163
164	return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
165}
166
167int
168res_query(const char *name,	/* domain name */
169	  int class, int type,	/* class and type of query */
170	  u_char *answer,	/* buffer to put answer */
171	  int anslen)		/* size of answer buffer */
172{
173	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
174		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
175		return (-1);
176	}
177	return (res_nquery(&_res, name, class, type, answer, anslen));
178}
179
180#ifndef _LIBC
181void
182res_send_setqhook(res_send_qhook hook) {
183	_res.qhook = hook;
184}
185
186void
187res_send_setrhook(res_send_rhook hook) {
188	_res.rhook = hook;
189}
190#endif
191
192int
193res_isourserver(const struct sockaddr_in *inp) {
194	return (res_ourserver_p(&_res, inp));
195}
196
197int
198res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
199	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
200		/* errno should have been set by res_init() in this case. */
201		return (-1);
202	}
203
204	return (res_nsend(&_res, buf, buflen, ans, anssiz));
205}
206
207#ifndef _LIBC
208int
209res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
210	       u_char *ans, int anssiz)
211{
212	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
213		/* errno should have been set by res_init() in this case. */
214		return (-1);
215	}
216
217	return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
218}
219#endif
220
221void
222res_close(void) {
223	res_nclose(&_res);
224}
225
226int
227res_update(ns_updrec *rrecp_in) {
228	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
229		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
230		return (-1);
231	}
232
233	return (res_nupdate(&_res, rrecp_in, NULL));
234}
235
236int
237res_search(const char *name,	/* domain name */
238	   int class, int type,	/* class and type of query */
239	   u_char *answer,	/* buffer to put answer */
240	   int anslen)		/* size of answer */
241{
242	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
243		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
244		return (-1);
245	}
246
247	return (res_nsearch(&_res, name, class, type, answer, anslen));
248}
249
250int
251res_querydomain(const char *name,
252		const char *domain,
253		int class, int type,	/* class and type of query */
254		u_char *answer,		/* buffer to put answer */
255		int anslen)		/* size of answer */
256{
257	if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
258		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
259		return (-1);
260	}
261
262	return (res_nquerydomain(&_res, name, domain,
263				 class, type,
264				 answer, anslen));
265}
266
267int
268res_opt(int n0, u_char *buf, int buflen, int anslen)
269{
270	return (res_nopt(&_res, n0, buf, buflen, anslen));
271}
272
273const char *
274hostalias(const char *name) {
275	static char abuf[MAXDNAME];
276
277	return (res_hostalias(&_res, name, abuf, sizeof abuf));
278}
279
280#ifdef ultrix
281int
282local_hostname_length(const char *hostname) {
283	int len_host, len_domain;
284
285	if (!*_res.defdname)
286		res_init();
287	len_host = strlen(hostname);
288	len_domain = strlen(_res.defdname);
289	if (len_host > len_domain &&
290	    !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
291	    hostname[len_host - len_domain - 1] == '.')
292		return (len_host - len_domain - 1);
293	return (0);
294}
295#endif /*ultrix*/
296
297/*
298 * Weak aliases for applications that use certain private entry points,
299 * and fail to include <resolv.h>.
300 */
301#undef res_init
302__weak_reference(__res_init, res_init);
303#undef p_query
304__weak_reference(__p_query, p_query);
305#undef res_mkquery
306__weak_reference(__res_mkquery, res_mkquery);
307#undef res_query
308__weak_reference(__res_query, res_query);
309#undef res_send
310__weak_reference(__res_send, res_send);
311#undef res_close
312__weak_reference(__res_close, _res_close);
313#undef res_search
314__weak_reference(__res_search, res_search);
315#undef res_querydomain
316__weak_reference(__res_querydomain, res_querydomain);
317
318#endif
319