1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)rec_open.c 8.10 (Berkeley) 9/1/94";
37 #endif /* LIBC_SCCS and not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD: stable/12/lib/libc/db/recno/rec_open.c 326025 2017-11-20 19:49:47Z pfg $");
40
41 #include "namespace.h"
42 #include <sys/types.h>
43 #include <sys/mman.h>
44 #include <sys/stat.h>
45
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <limits.h>
49 #include <stddef.h>
50 #include <stdio.h>
51 #include <unistd.h>
52 #include "un-namespace.h"
53
54 #include <db.h>
55 #include "recno.h"
56
57 DB *
__rec_open(const char * fname,int flags,int mode,const RECNOINFO * openinfo,int dflags)58 __rec_open(const char *fname, int flags, int mode, const RECNOINFO *openinfo,
59 int dflags)
60 {
61 BTREE *t;
62 BTREEINFO btopeninfo;
63 DB *dbp;
64 PAGE *h;
65 struct stat sb;
66 int rfd, sverrno;
67
68 /* Open the user's file -- if this fails, we're done. */
69 if (fname != NULL && (rfd = _open(fname, flags | O_CLOEXEC, mode)) < 0)
70 return (NULL);
71
72 /* Create a btree in memory (backed by disk). */
73 dbp = NULL;
74 if (openinfo) {
75 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
76 goto einval;
77 btopeninfo.flags = 0;
78 btopeninfo.cachesize = openinfo->cachesize;
79 btopeninfo.maxkeypage = 0;
80 btopeninfo.minkeypage = 0;
81 btopeninfo.psize = openinfo->psize;
82 btopeninfo.compare = NULL;
83 btopeninfo.prefix = NULL;
84 btopeninfo.lorder = openinfo->lorder;
85 dbp = __bt_open(openinfo->bfname,
86 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
87 } else
88 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags);
89 if (dbp == NULL)
90 goto err;
91
92 /*
93 * Some fields in the tree structure are recno specific. Fill them
94 * in and make the btree structure look like a recno structure. We
95 * don't change the bt_ovflsize value, it's close enough and slightly
96 * bigger.
97 */
98 t = dbp->internal;
99 if (openinfo) {
100 if (openinfo->flags & R_FIXEDLEN) {
101 F_SET(t, R_FIXLEN);
102 t->bt_reclen = openinfo->reclen;
103 if (t->bt_reclen == 0)
104 goto einval;
105 }
106 t->bt_bval = openinfo->bval;
107 } else
108 t->bt_bval = '\n';
109
110 F_SET(t, R_RECNO);
111 if (fname == NULL)
112 F_SET(t, R_EOF | R_INMEM);
113 else
114 t->bt_rfd = rfd;
115
116 if (fname != NULL) {
117 /*
118 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
119 * Unfortunately, that's not portable, so we use lseek
120 * and check the errno values.
121 */
122 errno = 0;
123 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
124 switch (flags & O_ACCMODE) {
125 case O_RDONLY:
126 F_SET(t, R_RDONLY);
127 break;
128 default:
129 goto einval;
130 }
131 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
132 goto err;
133 F_SET(t, R_CLOSEFP);
134 t->bt_irec =
135 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
136 } else {
137 switch (flags & O_ACCMODE) {
138 case O_RDONLY:
139 F_SET(t, R_RDONLY);
140 break;
141 case O_RDWR:
142 break;
143 default:
144 goto einval;
145 }
146
147 if (_fstat(rfd, &sb))
148 goto err;
149 /*
150 * Kluge -- we'd like to test to see if the file is too
151 * big to mmap. Since, we don't know what size or type
152 * off_t's or size_t's are, what the largest unsigned
153 * integral type is, or what random insanity the local
154 * C compiler will perpetrate, doing the comparison in
155 * a portable way is flatly impossible. Hope that mmap
156 * fails if the file is too large.
157 */
158 if (sb.st_size == 0)
159 F_SET(t, R_EOF);
160 else {
161 #ifdef MMAP_NOT_AVAILABLE
162 /*
163 * XXX
164 * Mmap doesn't work correctly on many current
165 * systems. In particular, it can fail subtly,
166 * with cache coherency problems. Don't use it
167 * for now.
168 */
169 t->bt_msize = sb.st_size;
170 if ((t->bt_smap = mmap(NULL, t->bt_msize,
171 PROT_READ, MAP_PRIVATE, rfd,
172 (off_t)0)) == MAP_FAILED)
173 goto slow;
174 t->bt_cmap = t->bt_smap;
175 t->bt_emap = t->bt_smap + sb.st_size;
176 t->bt_irec = F_ISSET(t, R_FIXLEN) ?
177 __rec_fmap : __rec_vmap;
178 F_SET(t, R_MEMMAPPED);
179 #else
180 goto slow;
181 #endif
182 }
183 }
184 }
185
186 /* Use the recno routines. */
187 dbp->close = __rec_close;
188 dbp->del = __rec_delete;
189 dbp->fd = __rec_fd;
190 dbp->get = __rec_get;
191 dbp->put = __rec_put;
192 dbp->seq = __rec_seq;
193 dbp->sync = __rec_sync;
194
195 /* If the root page was created, reset the flags. */
196 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
197 goto err;
198 if ((h->flags & P_TYPE) == P_BLEAF) {
199 F_CLR(h, P_TYPE);
200 F_SET(h, P_RLEAF);
201 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
202 } else
203 mpool_put(t->bt_mp, h, 0);
204
205 if (openinfo && openinfo->flags & R_SNAPSHOT &&
206 !F_ISSET(t, R_EOF | R_INMEM) &&
207 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
208 goto err;
209 return (dbp);
210
211 einval: errno = EINVAL;
212 err: sverrno = errno;
213 if (dbp != NULL)
214 (void)__bt_close(dbp);
215 if (fname != NULL)
216 (void)_close(rfd);
217 errno = sverrno;
218 return (NULL);
219 }
220
221 int
__rec_fd(const DB * dbp)222 __rec_fd(const DB *dbp)
223 {
224 BTREE *t;
225
226 t = dbp->internal;
227
228 /* Toss any page pinned across calls. */
229 if (t->bt_pinned != NULL) {
230 mpool_put(t->bt_mp, t->bt_pinned, 0);
231 t->bt_pinned = NULL;
232 }
233
234 /* In-memory database can't have a file descriptor. */
235 if (F_ISSET(t, R_INMEM)) {
236 errno = ENOENT;
237 return (-1);
238 }
239 return (t->bt_rfd);
240 }
241