1 /*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. ***REMOVED*** - see
14 * ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
15 * 4. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char sccsid[] = "@(#)db.c 8.4 (Berkeley) 2/21/94";
34 #endif /* LIBC_SCCS and not lint */
35
36 #ifndef __DBINTERFACE_PRIVATE
37 #define __DBINTERFACE_PRIVATE
38 #endif
39 #ifdef macintosh
40 #include <unix.h>
41 #else
42 #include <sys/types.h>
43 #endif
44
45 #include <errno.h>
46 #include <fcntl.h>
47 #include <stddef.h>
48 #include <stdio.h>
49
50 #include "mcom_db.h"
51
52 /* a global flag that locks closed all databases */
53 int all_databases_locked_closed = 0;
54
55 /* set or unset a global lock flag to disable the
56 * opening of any DBM file
57 */
58 void
dbSetOrClearDBLock(DBLockFlagEnum type)59 dbSetOrClearDBLock(DBLockFlagEnum type)
60 {
61 if (type == LockOutDatabase)
62 all_databases_locked_closed = 1;
63 else
64 all_databases_locked_closed = 0;
65 }
66
67 DB *
dbopen(const char * fname,int flags,int mode,DBTYPE type,const void * openinfo)68 dbopen(const char *fname, int flags, int mode, DBTYPE type, const void *openinfo)
69 {
70
71 /* lock out all file databases. Let in-memory databases through
72 */
73 if (all_databases_locked_closed && fname) {
74 errno = EINVAL;
75 return (NULL);
76 }
77
78 #define DB_FLAGS (DB_LOCK | DB_SHMEM | DB_TXN)
79
80 #if 0 /* most systems don't have EXLOCK and SHLOCK */
81 #define USE_OPEN_FLAGS \
82 (O_CREAT | O_EXCL | O_EXLOCK | O_NONBLOCK | O_RDONLY | \
83 O_RDWR | O_SHLOCK | O_TRUNC)
84 #else
85 #define USE_OPEN_FLAGS \
86 (O_CREAT | O_EXCL | O_RDONLY | \
87 O_RDWR | O_TRUNC)
88 #endif
89
90 if ((flags & ~(USE_OPEN_FLAGS | DB_FLAGS)) == 0)
91 switch (type) {
92 /* we don't need btree and recno right now */
93 #if 0
94 case DB_BTREE:
95 return (dbm_bt_open(fname, flags & USE_OPEN_FLAGS,
96 mode, openinfo, flags & DB_FLAGS));
97 case DB_RECNO:
98 return (dbm_rec_open(fname, flags & USE_OPEN_FLAGS,
99 mode, openinfo, flags & DB_FLAGS));
100 #endif
101
102 case DB_HASH:
103 return (dbm_hash_open(fname, flags & USE_OPEN_FLAGS,
104 mode, (const HASHINFO *)openinfo, flags & DB_FLAGS));
105 default:
106 break;
107 }
108 errno = EINVAL;
109 return (NULL);
110 }
111
112 static int
dbm_dberr()113 dbm_dberr()
114 {
115 return (RET_ERROR);
116 }
117
118 /*
119 * __DBPANIC -- Stop.
120 *
121 * Parameters:
122 * dbp: pointer to the DB structure.
123 */
124 void
dbm_dbpanic(DB * dbp)125 dbm_dbpanic(DB *dbp)
126 {
127 /* The only thing that can succeed is a close. */
128 dbp->del = (int (*)(const struct dbm_db *, const DBT *, uint))dbm_dberr;
129 dbp->fd = (int (*)(const struct dbm_db *))dbm_dberr;
130 dbp->get = (int (*)(const struct dbm_db *, const DBT *, DBT *, uint))dbm_dberr;
131 dbp->put = (int (*)(const struct dbm_db *, DBT *, const DBT *, uint))dbm_dberr;
132 dbp->seq = (int (*)(const struct dbm_db *, DBT *, DBT *, uint))dbm_dberr;
133 dbp->sync = (int (*)(const struct dbm_db *, uint))dbm_dberr;
134 }
135