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