1 /* $OpenBSD: rec_open.c,v 1.14 2020/12/01 16:19:38 millert Exp $ */
2
3 /*-
4 * Copyright (c) 1990, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Mike Olson.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/types.h>
36 #include <sys/mman.h>
37 #include <sys/stat.h>
38
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <limits.h>
42 #include <stddef.h>
43 #include <stdio.h>
44 #include <unistd.h>
45
46 #include <db.h>
47 #include "recno.h"
48
49 DB *
__rec_open(const char * fname,int flags,int mode,const RECNOINFO * openinfo,int dflags)50 __rec_open(const char *fname, int flags, int mode, const RECNOINFO *openinfo,
51 int dflags)
52 {
53 BTREE *t;
54 BTREEINFO btopeninfo;
55 DB *dbp;
56 PAGE *h;
57 struct stat sb;
58 int rfd, sverrno;
59
60 /* Open the user's file -- if this fails, we're done. */
61 if (fname != NULL && (rfd = open(fname, flags, mode)) < 0)
62 return (NULL);
63
64 /* Create a btree in memory (backed by disk). */
65 dbp = NULL;
66 if (openinfo) {
67 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
68 goto einval;
69 btopeninfo.flags = 0;
70 btopeninfo.cachesize = openinfo->cachesize;
71 btopeninfo.maxkeypage = 0;
72 btopeninfo.minkeypage = 0;
73 btopeninfo.psize = openinfo->psize;
74 btopeninfo.compare = NULL;
75 btopeninfo.prefix = NULL;
76 btopeninfo.lorder = openinfo->lorder;
77 dbp = __bt_open(openinfo->bfname,
78 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
79 } else
80 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags);
81 if (dbp == NULL)
82 goto err;
83
84 /*
85 * Some fields in the tree structure are recno specific. Fill them
86 * in and make the btree structure look like a recno structure. We
87 * don't change the bt_ovflsize value, it's close enough and slightly
88 * bigger.
89 */
90 t = dbp->internal;
91 if (openinfo) {
92 if (openinfo->flags & R_FIXEDLEN) {
93 F_SET(t, R_FIXLEN);
94 t->bt_reclen = openinfo->reclen;
95 if (t->bt_reclen == 0)
96 goto einval;
97 }
98 t->bt_bval = openinfo->bval;
99 } else
100 t->bt_bval = '\n';
101
102 F_SET(t, R_RECNO);
103 if (fname == NULL)
104 F_SET(t, R_EOF | R_INMEM);
105 else
106 t->bt_rfd = rfd;
107
108 if (fname != NULL) {
109 /*
110 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
111 * Unfortunately, that's not portable, so we use lseek
112 * and check the errno values.
113 */
114 errno = 0;
115 if (lseek(rfd, 0, SEEK_CUR) == -1 && errno == ESPIPE) {
116 switch (flags & O_ACCMODE) {
117 case O_RDONLY:
118 F_SET(t, R_RDONLY);
119 break;
120 default:
121 goto einval;
122 }
123 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
124 goto err;
125 F_SET(t, R_CLOSEFP);
126 t->bt_irec =
127 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
128 } else {
129 switch (flags & O_ACCMODE) {
130 case O_RDONLY:
131 F_SET(t, R_RDONLY);
132 break;
133 case O_RDWR:
134 break;
135 default:
136 goto einval;
137 }
138
139 if (fstat(rfd, &sb))
140 goto err;
141 if (sb.st_size == 0)
142 F_SET(t, R_EOF);
143 else {
144 goto slow;
145 }
146 }
147 }
148
149 /* Use the recno routines. */
150 dbp->close = __rec_close;
151 dbp->del = __rec_delete;
152 dbp->fd = __rec_fd;
153 dbp->get = __rec_get;
154 dbp->put = __rec_put;
155 dbp->seq = __rec_seq;
156 dbp->sync = __rec_sync;
157 dbp->type = DB_RECNO;
158
159 /* If the root page was created, reset the flags. */
160 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
161 goto err;
162 if ((h->flags & P_TYPE) == P_BLEAF) {
163 F_CLR(h, P_TYPE);
164 F_SET(h, P_RLEAF);
165 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
166 } else
167 mpool_put(t->bt_mp, h, 0);
168
169 if (openinfo && openinfo->flags & R_SNAPSHOT &&
170 !F_ISSET(t, R_EOF | R_INMEM) &&
171 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
172 goto err;
173 return (dbp);
174
175 einval: errno = EINVAL;
176 err: sverrno = errno;
177 if (dbp != NULL)
178 (void)__bt_close(dbp);
179 if (fname != NULL)
180 (void)close(rfd);
181 errno = sverrno;
182 return (NULL);
183 }
184
185 int
__rec_fd(const DB * dbp)186 __rec_fd(const DB *dbp)
187 {
188 BTREE *t;
189
190 t = dbp->internal;
191
192 /* Toss any page pinned across calls. */
193 if (t->bt_pinned != NULL) {
194 mpool_put(t->bt_mp, t->bt_pinned, 0);
195 t->bt_pinned = NULL;
196 }
197
198 /* In-memory database can't have a file descriptor. */
199 if (F_ISSET(t, R_INMEM)) {
200 errno = ENOENT;
201 return (-1);
202 }
203 return (t->bt_rfd);
204 }
205