source: trunk/server/lib/tdb/common/open.c@ 916

Last change on this file since 916 was 916, checked in by Silvan Scherrer, 10 years ago

Samba Server: update trunk to version 3.6.25, fix some more crlf issues
File size: 17.6 KB
Line 
1 /*
2 Unix SMB/CIFS implementation.
3
4 trivial database library
5
6 Copyright (C) Andrew Tridgell 1999-2005
7 Copyright (C) Paul `Rusty' Russell 2000
8 Copyright (C) Jeremy Allison 2000-2003
9
10 ** NOTE! The following LGPL license applies to the tdb
11 ** library. This does NOT imply that all of Samba is released
12 ** under the LGPL
13
14 This library is free software; you can redistribute it and/or
15 modify it under the terms of the GNU Lesser General Public
16 License as published by the Free Software Foundation; either
17 version 3 of the License, or (at your option) any later version.
18
19 This library is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 Lesser General Public License for more details.
23
24 You should have received a copy of the GNU Lesser General Public
25 License along with this library; if not, see <http://www.gnu.org/licenses/>.
26*/
27
28#include "tdb_private.h"
29
30/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
31static struct tdb_context *tdbs = NULL;
32
33/* We use two hashes to double-check they're using the right hash function. */
34void tdb_header_hash(struct tdb_context *tdb,
35 uint32_t *magic1_hash, uint32_t *magic2_hash)
36{
37 TDB_DATA hash_key;
38 uint32_t tdb_magic = TDB_MAGIC;
39
40 hash_key.dptr = discard_const_p(unsigned char, TDB_MAGIC_FOOD);
41 hash_key.dsize = sizeof(TDB_MAGIC_FOOD);
42 *magic1_hash = tdb->hash_fn(&hash_key);
43
44 hash_key.dptr = (unsigned char *)CONVERT(tdb_magic);
45 hash_key.dsize = sizeof(tdb_magic);
46 *magic2_hash = tdb->hash_fn(&hash_key);
47
48 /* Make sure at least one hash is non-zero! */
49 if (*magic1_hash == 0 && *magic2_hash == 0)
50 *magic1_hash = 1;
51}
52
53/* initialise a new database with a specified hash size */
54static int tdb_new_database(struct tdb_context *tdb, int hash_size)
55{
56 struct tdb_header *newdb;
57 size_t size;
58 int ret = -1;
59
60 /* We make it up in memory, then write it out if not internal */
61 size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off_t);
62 if (!(newdb = (struct tdb_header *)calloc(size, 1))) {
63 tdb->ecode = TDB_ERR_OOM;
64 return -1;
65 }
66
67 /* Fill in the header */
68 newdb->version = TDB_VERSION;
69 newdb->hash_size = hash_size;
70
71 tdb_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
72
73 /* Make sure older tdbs (which don't check the magic hash fields)
74 * will refuse to open this TDB. */
75 if (tdb->flags & TDB_INCOMPATIBLE_HASH)
76 newdb->rwlocks = TDB_HASH_RWLOCK_MAGIC;
77
78 if (tdb->flags & TDB_INTERNAL) {
79 tdb->map_size = size;
80 tdb->map_ptr = (char *)newdb;
81 memcpy(&tdb->header, newdb, sizeof(tdb->header));
82 /* Convert the `ondisk' version if asked. */
83 CONVERT(*newdb);
84 return 0;
85 }
86 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
87 goto fail;
88
89 if (ftruncate(tdb->fd, 0) == -1)
90 goto fail;
91
92 /* This creates an endian-converted header, as if read from disk */
93 CONVERT(*newdb);
94 memcpy(&tdb->header, newdb, sizeof(tdb->header));
95 /* Don't endian-convert the magic food! */
96 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
97 /* we still have "ret == -1" here */
98 if (tdb_write_all(tdb->fd, newdb, size))
99 ret = 0;
100
101 fail:
102 SAFE_FREE(newdb);
103 return ret;
104}
105
106
107
108static int tdb_already_open(dev_t device,
109 ino_t ino)
110{
111 struct tdb_context *i;
112
113 for (i = tdbs; i; i = i->next) {
114 if (i->device == device && i->inode == ino) {
115 return 1;
116 }
117 }
118
119 return 0;
120}
121
122/* open the database, creating it if necessary
123
124 The open_flags and mode are passed straight to the open call on the
125 database file. A flags value of O_WRONLY is invalid. The hash size
126 is advisory, use zero for a default value.
127
128 Return is NULL on error, in which case errno is also set. Don't
129 try to call tdb_error or tdb_errname, just do strerror(errno).
130
131 @param name may be NULL for internal databases. */
132_PUBLIC_ struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags,
133 int open_flags, mode_t mode)
134{
135 return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL);
136}
137
138/* a default logging function */
139static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
140static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
141{
142}
143
144static bool check_header_hash(struct tdb_context *tdb,
145 bool default_hash, uint32_t *m1, uint32_t *m2)
146{
147 tdb_header_hash(tdb, m1, m2);
148 if (tdb->header.magic1_hash == *m1 &&
149 tdb->header.magic2_hash == *m2) {
150 return true;
151 }
152
153 /* If they explicitly set a hash, always respect it. */
154 if (!default_hash)
155 return false;
156
157 /* Otherwise, try the other inbuilt hash. */
158 if (tdb->hash_fn == tdb_old_hash)
159 tdb->hash_fn = tdb_jenkins_hash;
160 else
161 tdb->hash_fn = tdb_old_hash;
162 return check_header_hash(tdb, false, m1, m2);
163}
164
165_PUBLIC_ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
166 int open_flags, mode_t mode,
167 const struct tdb_logging_context *log_ctx,
168 tdb_hash_func hash_fn)
169{
170 struct tdb_context *tdb;
171 struct stat st;
172 int rev = 0, locked = 0;
173 unsigned char *vp;
174 uint32_t vertest;
175 unsigned v;
176 const char *hash_alg;
177 uint32_t magic1, magic2;
178
179 if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
180 /* Can't log this */
181 errno = ENOMEM;
182 goto fail;
183 }
184 tdb_io_init(tdb);
185 tdb->fd = -1;
186#ifdef TDB_TRACE
187 tdb->tracefd = -1;
188#endif
189 tdb->name = NULL;
190 tdb->map_ptr = NULL;
191 tdb->flags = tdb_flags;
192#ifdef __OS2__
193 open_flags |= O_BINARY;
194#endif
195 tdb->open_flags = open_flags;
196 if (log_ctx) {
197 tdb->log = *log_ctx;
198 } else {
199 tdb->log.log_fn = null_log_fn;
200 tdb->log.log_private = NULL;
201 }
202
203 if (name == NULL && (tdb_flags & TDB_INTERNAL)) {
204 name = "__TDB_INTERNAL__";
205 }
206
207 if (name == NULL) {
208 tdb->name = discard_const_p(char, "__NULL__");
209 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: called with name == NULL\n"));
210 tdb->name = NULL;
211 errno = EINVAL;
212 goto fail;
213 }
214
215 /* now make a copy of the name, as the caller memory might went away */
216 if (!(tdb->name = (char *)strdup(name))) {
217 /*
218 * set the name as the given string, so that tdb_name() will
219 * work in case of an error.
220 */
221 tdb->name = discard_const_p(char, name);
222 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't strdup(%s)\n",
223 name));
224 tdb->name = NULL;
225 errno = ENOMEM;
226 goto fail;
227 }
228
229 if (hash_fn) {
230 tdb->hash_fn = hash_fn;
231 hash_alg = "the user defined";
232 } else {
233 /* This controls what we use when creating a tdb. */
234 if (tdb->flags & TDB_INCOMPATIBLE_HASH) {
235 tdb->hash_fn = tdb_jenkins_hash;
236 } else {
237 tdb->hash_fn = tdb_old_hash;
238 }
239 hash_alg = "either default";
240 }
241
242 /* cache the page size */
243 tdb->page_size = getpagesize();
244 if (tdb->page_size <= 0) {
245 tdb->page_size = 0x2000;
246 }
247
248 tdb->max_dead_records = (tdb_flags & TDB_VOLATILE) ? 5 : 0;
249
250 if ((open_flags & O_ACCMODE) == O_WRONLY) {
251 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n",
252 name));
253 errno = EINVAL;
254 goto fail;
255 }
256
257 if (hash_size == 0)
258 hash_size = DEFAULT_HASH_SIZE;
259 if ((open_flags & O_ACCMODE) == O_RDONLY) {
260 tdb->read_only = 1;
261 /* read only databases don't do locking or clear if first */
262 tdb->flags |= TDB_NOLOCK;
263 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
264 }
265
266 if ((tdb->flags & TDB_ALLOW_NESTING) &&