ypdb.c revision 1.13 
1/*	$NetBSD: ypdb.c,v 1.13 2023/08/01 08:47:25 mrg Exp $	*/
2
3/*
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Margo Seltzer.
10 *
11 * This code is derived from ndbm module of BSD4.4 db (hash) by
12 * Mats O Jansson
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 *    notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *    notice, this list of conditions and the following disclaimer in the
21 *    documentation and/or other materials provided with the distribution.
22 * 3. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
27 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
28 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
30 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39#include <sys/cdefs.h>
40#ifndef lint
41__RCSID("$NetBSD: ypdb.c,v 1.13 2023/08/01 08:47:25 mrg Exp $");
42#endif
43
44#include <sys/param.h>
45#include <sys/types.h>
46#include <sys/stat.h>
47
48#include <db.h>
49#include <err.h>
50#include <errno.h>
51#include <fcntl.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <unistd.h>
56
57#include <rpcsvc/yp.h>
58
59#include "ypdb.h"
60
61static DBM	*_ypdb_dbopen(const char *, int, mode_t);
62
63/*
64 * ypdb_open --
65 *	dbopen(3) file, read-only.
66 *	First ensure that file has a suffix of YPDB_SUFFIX.
67 *	Try opening as a DB_BTREE first, then DB_HASH.
68 *
69 * Returns:
70 *	*DBM on success
71 *	 NULL on failure
72 */
73
74DBM *
75ypdb_open(const char *file)
76{
77	char path[MAXPATHLEN];
78	const char *cp, *suffix;
79
80	cp = strrchr(file, '.');
81	if (cp != NULL && strcmp(cp, YPDB_SUFFIX) == 0)
82		suffix = "";
83	else
84		suffix = YPDB_SUFFIX;
85	if ((size_t)snprintf(path, sizeof(path), "%s%s", file, suffix) >
86	    sizeof(path)) {
87		warnx("File name `%s' is too long", file);
88		return NULL;
89	}
90	return _ypdb_dbopen(path, O_RDONLY, 0444);
91}
92
93/*
94 * ypdb_mktemp --
95 *	Create a temporary file using mkstemp(3) based on the
96 *	template provided in file.
97 *	dbopen(3) file, read-write, 0644 (modified by umask(2)).
98 *	Try opening as a DB_BTREE first, then DB_HASH.
99 *	file won't have YPDB_SUFFIX.
100 *
101 * Returns:
102 *	*DBM on success; file now exists.
103 *	 NULL on failure
104 */
105
106DBM *
107ypdb_mktemp(char *file)
108{
109	int fd = -1;
110	DBM *db = NULL;
111	mode_t myumask;
112	int save_errno;
113
114	if ((fd = mkstemp(file)) == -1)
115		return NULL;
116
117	myumask = umask(0);
118	(void)umask(myumask);
119	if (fchmod(fd, 0644 & ~myumask) == -1)
120		goto bad;
121
122	(void) close(fd);
123	fd = -1;
124
125	if ((db = _ypdb_dbopen(file, O_RDWR, 0644)) == NULL)
126		goto bad;
127
128	return db;
129
130 bad:
131	save_errno = errno;
132	if (fd != 1)
133		(void) close(fd);
134	(void) unlink(file);
135	errno = save_errno;
136	return NULL;
137}
138
139/*
140 * _ypdb_dbopen --
141 *	dbopen(3) path with the flags & mode.
142 *	Try opening as a DB_BTREE first, then DB_HASH.
143 */
144
145static DBM *
146_ypdb_dbopen(const char *path, int flags, mode_t mode)
147{
148	DBM *db;
149	BTREEINFO info;
150
151		/* try our btree format first */
152	info.flags = 0;
153	info.cachesize = 0;
154	info.maxkeypage = 0;
155	info.minkeypage = 0;
156	info.psize = 0;
157	info.compare = NULL;
158	info.prefix = NULL;
159	info.lorder = 0;
160	db = (DBM *)dbopen(path, flags, mode, DB_BTREE, (void *)&info);
161	if (db != NULL || errno != EFTYPE)
162		return (db);
163
164		/* fallback to standard hash (for sendmail's aliases.db) */
165	db = (DBM *)dbopen(path, flags, mode, DB_HASH, NULL);
166	return (db);
167}
168
169/*
170 * ypdb_close --
171 *	Close the db
172 */
173
174void
175ypdb_close(DBM *db)
176{
177	(void)(db->close)(db);
178}
179
180/*
181 * Returns:
182 *	DATUM on success
183 *	NULL on failure
184 */
185
186datum
187ypdb_fetch(DBM *db, datum key)
188{
189	datum retkey;
190	DBT nk, nd;
191	int status;
192
193	nk.data = key.dptr;
194	nk.size = key.dsize;
195	status = (db->get)(db, &nk, &nd, 0);
196	if (status) {
197		retkey.dptr = NULL;
198		retkey.dsize = 0;
199	} else {
200		retkey.dptr = nd.data;
201		retkey.dsize = nd.size;
202	}
203	return (retkey);
204}
205
206/*
207 * Returns:
208 *	DATUM on success
209 *	NULL on failure
210 */
211
212datum
213ypdb_firstkey(DBM *db)
214{
215	int status;
216	datum retkey;
217	DBT nk, nd;
218
219	status = (db->seq)(db, &nk, &nd, R_FIRST);
220	if (status) {
221		retkey.dptr = NULL;
222		retkey.dsize = 0;
223	} else {
224		retkey.dptr = nk.data;
225		retkey.dsize = nk.size;
226	}
227	return (retkey);
228}
229
230/*
231 * Returns:
232 *	DATUM on success
233 *	NULL on failure
234 */
235
236datum
237ypdb_nextkey(DBM *db)
238{
239	int status;
240	datum retkey;
241	DBT nk, nd;
242
243	status = (db->seq)(db, &nk, &nd, R_NEXT);
244	if (status) {
245		retkey.dptr = NULL;
246		retkey.dsize = 0;
247	} else {
248		retkey.dptr = nk.data;
249		retkey.dsize = nk.size;
250	}
251	return (retkey);
252}
253
254/*
255 * Returns:
256 *	DATUM on success
257 *	NULL on failure
258 */
259
260datum
261ypdb_setkey(DBM *db, datum key)
262{
263	int status;
264	DBT nk, nd;
265
266	nk.data = key.dptr;
267	nk.size = key.dsize;
268	status = (db->seq)(db, &nk, &nd, R_CURSOR);
269	if (status) {
270		key.dptr = NULL;
271		key.dsize = 0;
272	}
273	return (key);
274}
275
276/*
277 * Returns:
278 *	 0 on success
279 *	<0 failure
280 */
281
282int
283ypdb_delete(DBM *db, datum key)
284{
285	int status;
286	DBT nk;
287
288	nk.data = key.dptr;
289	nk.size = key.dsize;
290	status = (db->del)(db, &nk, 0);
291	if (status)
292		return (-1);
293	else
294		return (0);
295}
296
297/*
298 * Returns:
299 *	 0 on success
300 *	<0 failure
301 *	 1 if YPDB_INSERT and entry exists
302 */
303
304int
305ypdb_store(DBM *db, datum key, datum content, int flags)
306{
307	DBT nk, nd;
308
309	if (key.dsize > YPMAXRECORD || content.dsize > YPMAXRECORD)
310		return -1;
311	nk.data = key.dptr;
312	nk.size = key.dsize;
313	nd.data = content.dptr;
314	nd.size = content.dsize;
315	return ((db->put)(db, &nk, &nd,
316	    (flags == YPDB_INSERT) ? R_NOOVERWRITE : 0));
317}
318