1 /*
2 ** Copyright (c) 1999-2002 Sendmail, Inc. and its suppliers.
3 ** All rights reserved.
4 **
5 ** By using this file, you agree to the terms and conditions set
6 ** forth in the LICENSE file which can be found at the top level of
7 ** the sendmail distribution.
8 */
9
10 #include <sm/gen.h>
11 SM_RCSID("@(#)$Id: smdb.c,v 8.58 2004/08/03 20:58:38 ca Exp $")
12
13 #include <fcntl.h>
14 #include <stdlib.h>
15 #include <unistd.h>
16
17
18 #include <sendmail/sendmail.h>
19 #include <libsmdb/smdb.h>
20
21 static bool smdb_lockfile __P((int, int));
22
23 /*
24 ** SMDB_MALLOC_DATABASE -- Allocates a database structure.
25 **
26 ** Parameters:
27 ** None
28 **
29 ** Returns:
30 ** An pointer to an allocated SMDB_DATABASE structure or
31 ** NULL if it couldn't allocate the memory.
32 */
33
34 SMDB_DATABASE *
smdb_malloc_database()35 smdb_malloc_database()
36 {
37 SMDB_DATABASE *db;
38
39 db = (SMDB_DATABASE *) malloc(sizeof(SMDB_DATABASE));
40
41 if (db != NULL)
42 (void) memset(db, '\0', sizeof(SMDB_DATABASE));
43
44 return db;
45 }
46
47
48 /*
49 ** SMDB_FREE_DATABASE -- Unallocates a database structure.
50 **
51 ** Parameters:
52 ** database -- a SMDB_DATABASE pointer to deallocate.
53 **
54 ** Returns:
55 ** None
56 */
57
58 void
smdb_free_database(database)59 smdb_free_database(database)
60 SMDB_DATABASE *database;
61 {
62 if (database != NULL)
63 free(database);
64 }
65 /*
66 ** SMDB_LOCKFILE -- lock a file using flock or (shudder) fcntl locking
67 **
68 ** Parameters:
69 ** fd -- the file descriptor of the file.
70 ** type -- type of the lock. Bits can be:
71 ** LOCK_EX -- exclusive lock.
72 ** LOCK_NB -- non-blocking.
73 **
74 ** Returns:
75 ** true if the lock was acquired.
76 ** false otherwise.
77 */
78
79 static bool
smdb_lockfile(fd,type)80 smdb_lockfile(fd, type)
81 int fd;
82 int type;
83 {
84 int i;
85 int save_errno;
86 #if !HASFLOCK
87 int action;
88 struct flock lfd;
89
90 (void) memset(&lfd, '\0', sizeof lfd);
91 if (bitset(LOCK_UN, type))
92 lfd.l_type = F_UNLCK;
93 else if (bitset(LOCK_EX, type))
94 lfd.l_type = F_WRLCK;
95 else
96 lfd.l_type = F_RDLCK;
97
98 if (bitset(LOCK_NB, type))
99 action = F_SETLK;
100 else
101 action = F_SETLKW;
102
103 while ((i = fcntl(fd, action, &lfd)) < 0 && errno == EINTR)
104 continue;
105 if (i >= 0)
106 return true;
107 save_errno = errno;
108
109 /*
110 ** On SunOS, if you are testing using -oQ/tmp/mqueue or
111 ** -oA/tmp/aliases or anything like that, and /tmp is mounted
112 ** as type "tmp" (that is, served from swap space), the
113 ** previous fcntl will fail with "Invalid argument" errors.
114 ** Since this is fairly common during testing, we will assume
115 ** that this indicates that the lock is successfully grabbed.
116 */
117
118 if (save_errno == EINVAL)
119 return true;
120
121 if (!bitset(LOCK_NB, type) ||
122 (save_errno != EACCES && save_errno != EAGAIN))
123 {
124 # if 0
125 int omode = fcntl(fd, F_GETFL, NULL);
126 int euid = (int) geteuid();
127
128 syslog(LOG_ERR, "cannot lockf(%s%s, fd=%d, type=%o, omode=%o, euid=%d)",
129 filename, ext, fd, type, omode, euid);
130 # endif /* 0 */
131 errno = save_errno;
132 return false;
133 }
134 #else /* !HASFLOCK */
135
136 while ((i = flock(fd, type)) < 0 && errno == EINTR)
137 continue;
138 if (i >= 0)
139 return true;
140 save_errno = errno;
141
142 if (!bitset(LOCK_NB, type) || save_errno != EWOULDBLOCK)
143 {
144 # if 0
145 int omode = fcntl(fd, F_GETFL, NULL);
146 int euid = (int) geteuid();
147
148 syslog(LOG_ERR, "cannot flock(%s%s, fd=%d, type=%o, omode=%o, euid=%d)",
149 filename, ext, fd, type, omode, euid);
150 # endif /* 0 */
151 errno = save_errno;
152 return false;
153 }
154 #endif /* !HASFLOCK */
155 errno = save_errno;
156 return false;
157 }
158 /*
159 ** SMDB_OPEN_DATABASE -- Opens a database.
160 **
161 ** This opens a database. If type is SMDB_DEFAULT it tries to
162 ** use a DB1 or DB2 hash. If that isn't available, it will try
163 ** to use NDBM. If a specific type is given it will try to open
164 ** a database of that type.
165 **
166 ** Parameters:
167 ** database -- An pointer to a SMDB_DATABASE pointer where the
168 ** opened database will be stored. This should
169 ** be unallocated.
170 ** db_name -- The name of the database to open. Do not include
171 ** the file name extension.
172 ** mode -- The mode to set on the database file or files.
173 ** mode_mask -- Mode bits that must match on an opened database.
174 ** sff -- Flags to safefile.
175 ** type -- The type of database to open. Supported types
176 ** vary depending on what was compiled in.
177 ** user_info -- Information on the user to use for file
178 ** permissions.
179 ** params -- Params specific to the database being opened.
180 ** Only supports some DB hash options right now
181 ** (see smdb_db_open() for details).
182 **
183 ** Returns:
184 ** SMDBE_OK -- Success.
185 ** Anything else is an error. Look up more info about the
186 ** error in the comments for the specific open() used.
187 */
188
189 int
smdb_open_database(database,db_name,mode,mode_mask,sff,type,user_info,params)190 smdb_open_database(database, db_name, mode, mode_mask, sff, type, user_info,
191 params)
192 SMDB_DATABASE **database;
193 char *db_name;
194 int mode;
195 int mode_mask;
196 long sff;
197 SMDB_DBTYPE type;
198 SMDB_USER_INFO *user_info;
199 SMDB_DBPARAMS *params;
200 {
201 bool type_was_default = false;
202
203 if (type == SMDB_TYPE_DEFAULT)
204 {
205 type_was_default = true;
206 #ifdef NEWDB
207 type = SMDB_TYPE_HASH;
208 #else /* NEWDB */
209 # ifdef NDBM
210 type = SMDB_TYPE_NDBM;
211 # endif /* NDBM */
212 #endif /* NEWDB */
213 }
214
215 if (type == SMDB_TYPE_DEFAULT)
216 return SMDBE_UNKNOWN_DB_TYPE;
217
218 if ((strncmp(type, SMDB_TYPE_HASH, SMDB_TYPE_HASH_LEN) == 0) ||
219 (strncmp(type, SMDB_TYPE_BTREE, SMDB_TYPE_BTREE_LEN) == 0))
220 {
221 #ifdef NEWDB
222 int result;
223
224 result = smdb_db_open(database, db_name, mode, mode_mask, sff,
225 type, user_info, params);
226 # ifdef NDBM
227 if (result == ENOENT && type_was_default)
228 type = SMDB_TYPE_NDBM;
229 else
230 # endif /* NDBM */
231 return result;
232 #else /* NEWDB */
233 return SMDBE_UNSUPPORTED_DB_TYPE;
234 #endif /* NEWDB */
235 }
236
237 if (strncmp(type, SMDB_TYPE_NDBM, SMDB_TYPE_NDBM_LEN) == 0)
238 {
239 #ifdef NDBM
240 int result;
241
242 result = smdb_ndbm_open(database, db_name, mode, mode_mask,
243 sff, type, user_info, params);
244 return result;
245 #else /* NDBM */
246 return SMDBE_UNSUPPORTED_DB_TYPE;
247 #endif /* NDBM */
248 }
249
250 return SMDBE_UNKNOWN_DB_TYPE;
251 }
252 /*
253 ** SMDB_ADD_EXTENSION -- Adds an extension to a file name.
254 **
255 ** Just adds a . followed by a string to a db_name if there
256 ** is room and the db_name does not already have that extension.
257 **
258 ** Parameters:
259 ** full_name -- The final file name.
260 ** max_full_name_len -- The max length for full_name.
261 ** db_name -- The name of the db.
262 ** extension -- The extension to add.
263 **
264 ** Returns:
265 ** SMDBE_OK -- Success.
266 ** Anything else is an error. Look up more info about the
267 ** error in the comments for the specific open() used.
268 */
269
270 int
smdb_add_extension(full_name,max_full_name_len,db_name,extension)271 smdb_add_extension(full_name, max_full_name_len, db_name, extension)
272 char *full_name;
273 int max_full_name_len;
274 char *db_name;
275 char *extension;
276 {
277 int extension_len;
278 int db_name_len;
279
280 if (full_name == NULL || db_name == NULL || extension == NULL)
281 return SMDBE_INVALID_PARAMETER;
282
283 extension_len = strlen(extension);
284 db_name_len = strlen(db_name);
285
286 if (extension_len + db_name_len + 2 > max_full_name_len)
287 return SMDBE_DB_NAME_TOO_LONG;
288
289 if (db_name_len < extension_len + 1 ||
290 db_name[db_name_len - extension_len - 1] != '.' ||
291 strcmp(&db_name[db_name_len - extension_len], extension) != 0)
292 (void) sm_snprintf(full_name, max_full_name_len, "%s.%s",
293 db_name, extension);
294 else
295 (void) sm_strlcpy(full_name, db_name, max_full_name_len);
296
297 return SMDBE_OK;
298 }
299 /*
300 ** SMDB_LOCK_FILE -- Locks the database file.
301 **
302 ** Locks the actual database file.
303 **
304 ** Parameters:
305 ** lock_fd -- The resulting descriptor for the locked file.
306 ** db_name -- The name of the database without extension.
307 ** mode -- The open mode.
308 ** sff -- Flags to safefile.
309 ** extension -- The extension for the file.
310 **
311 ** Returns:
312 ** SMDBE_OK -- Success, otherwise errno.
313 */
314
315 int
smdb_lock_file(lock_fd,db_name,mode,sff,extension)316 smdb_lock_file(lock_fd, db_name, mode, sff, extension)
317 int *lock_fd;
318 char *db_name;
319 int mode;
320 long sff;
321 char *extension;
322 {
323 int result;
324 char file_name[MAXPATHLEN];
325
326 result = smdb_add_extension(file_name, sizeof file_name, db_name,
327 extension);
328 if (result != SMDBE_OK)
329 return result;
330
331 *lock_fd = safeopen(file_name, mode & ~O_TRUNC, DBMMODE, sff);
332 if (*lock_fd < 0)
333 return errno;
334
335 return SMDBE_OK;
336 }
337 /*
338 ** SMDB_UNLOCK_FILE -- Unlocks a file
339 **
340 ** Unlocks a file.
341 **
342 ** Parameters:
343 ** lock_fd -- The descriptor for the locked file.
344 **
345 ** Returns:
346 ** SMDBE_OK -- Success, otherwise errno.
347 */
348
349 int
smdb_unlock_file(lock_fd)350 smdb_unlock_file(lock_fd)
351 int lock_fd;
352 {
353 int result;
354
355 result = close(lock_fd);
356 if (result != 0)
357 return errno;
358
359 return SMDBE_OK;
360 }
361 /*
362 ** SMDB_LOCK_MAP -- Locks a database.
363 **
364 ** Parameters:
365 ** database -- database description.
366 ** type -- type of the lock. Bits can be:
367 ** LOCK_EX -- exclusive lock.
368 ** LOCK_NB -- non-blocking.
369 **
370 ** Returns:
371 ** SMDBE_OK -- Success, otherwise errno.
372 */
373
374 int
smdb_lock_map(database,type)375 smdb_lock_map(database, type)
376 SMDB_DATABASE *database;
377 int type;
378 {
379 int fd;
380
381 fd = database->smdb_lockfd(database);
382 if (fd < 0)
383 return SMDBE_NOT_FOUND;
384 if (!smdb_lockfile(fd, type))
385 return SMDBE_LOCK_NOT_GRANTED;
386 return SMDBE_OK;
387 }
388 /*
389 ** SMDB_UNLOCK_MAP -- Unlocks a database
390 **
391 ** Parameters:
392 ** database -- database description.
393 **
394 ** Returns:
395 ** SMDBE_OK -- Success, otherwise errno.
396 */
397
398 int
smdb_unlock_map(database)399 smdb_unlock_map(database)
400 SMDB_DATABASE *database;
401 {
402 int fd;
403
404 fd = database->smdb_lockfd(database);
405 if (fd < 0)
406 return SMDBE_NOT_FOUND;
407 if (!smdb_lockfile(fd, LOCK_UN))
408 return SMDBE_LOCK_NOT_HELD;
409 return SMDBE_OK;
410 }
411 /*
412 ** SMDB_SETUP_FILE -- Gets db file ready for use.
413 **
414 ** Makes sure permissions on file are safe and creates it if it
415 ** doesn't exist.
416 **
417 ** Parameters:
418 ** db_name -- The name of the database without extension.
419 ** extension -- The extension.
420 ** sff -- Flags to safefile.
421 ** mode_mask -- Mode bits that must match.
422 ** user_info -- Information on the user to use for file
423 ** permissions.
424 ** stat_info -- A place to put the stat info for the file.
425 ** Returns:
426 ** SMDBE_OK -- Success, otherwise errno.
427 */
428
429 int
smdb_setup_file(db_name,extension,mode_mask,sff,user_info,stat_info)430 smdb_setup_file(db_name, extension, mode_mask, sff, user_info, stat_info)
431 char *db_name;
432 char *extension;
433 int mode_mask;
434 long sff;
435 SMDB_USER_INFO *user_info;
436 struct stat *stat_info;
437 {
438 int st;
439 int result;
440 char db_file_name[MAXPATHLEN];
441
442 result = smdb_add_extension(db_file_name, sizeof db_file_name, db_name,
443 extension);
444 if (result != SMDBE_OK)
445 return result;
446
447 st = safefile(db_file_name, user_info->smdbu_id,
448 user_info->smdbu_group_id, user_info->smdbu_name,
449 sff, mode_mask, stat_info);
450 if (st != 0)
451 return st;
452
453 return SMDBE_OK;
454 }
455 /*
456 ** SMDB_FILECHANGED -- Checks to see if a file changed.
457 **
458 ** Compares the passed in stat_info with a current stat on
459 ** the passed in file descriptor. Check filechanged for
460 ** return values.
461 **
462 ** Parameters:
463 ** db_name -- The name of the database without extension.
464 ** extension -- The extension.
465 ** db_fd -- A file descriptor for the database file.
466 ** stat_info -- An old stat_info.
467 ** Returns:
468 ** SMDBE_OK -- Success, otherwise errno.
469 */
470
471 int
smdb_filechanged(db_name,extension,db_fd,stat_info)472 smdb_filechanged(db_name, extension, db_fd, stat_info)
473 char *db_name;
474 char *extension;
475 int db_fd;
476 struct stat *stat_info;
477 {
478 int result;
479 char db_file_name[MAXPATHLEN];
480
481 result = smdb_add_extension(db_file_name, sizeof db_file_name, db_name,
482 extension);
483 if (result != SMDBE_OK)
484 return result;
485 return filechanged(db_file_name, db_fd, stat_info);
486 }
487 /*
488 ** SMDB_PRINT_AVAILABLE_TYPES -- Prints the names of the available types.
489 **
490 ** Parameters:
491 ** None
492 **
493 ** Returns:
494 ** None
495 */
496
497 void
smdb_print_available_types()498 smdb_print_available_types()
499 {
500 #ifdef NDBM
501 printf("dbm\n");
502 #endif /* NDBM */
503 #ifdef NEWDB
504 printf("hash\n");
505 printf("btree\n");
506 #endif /* NEWDB */
507 }
508 /*
509 ** SMDB_DB_DEFINITION -- Given a database type, return database definition
510 **
511 ** Reads though a structure making an association with the database
512 ** type and the required cpp define from sendmail/README.
513 ** List size is dynamic and must be NULL terminated.
514 **
515 ** Parameters:
516 ** type -- The name of the database type.
517 **
518 ** Returns:
519 ** definition for type, otherwise NULL.
520 */
521
522 typedef struct
523 {
524 SMDB_DBTYPE type;
525 char *dbdef;
526 } dbtype;
527
528 static dbtype DatabaseDefs[] =
529 {
530 { SMDB_TYPE_HASH, "NEWDB" },
531 { SMDB_TYPE_BTREE, "NEWDB" },
532 { SMDB_TYPE_NDBM, "NDBM" },
533 { NULL, "OOPS" }
534 };
535
536 char *
smdb_db_definition(type)537 smdb_db_definition(type)
538 SMDB_DBTYPE type;
539 {
540 dbtype *ptr = DatabaseDefs;
541
542 while (ptr != NULL && ptr->type != NULL)
543 {
544 if (strcmp(type, ptr->type) == 0)
545 return ptr->dbdef;
546 ptr++;
547 }
548 return NULL;
549 }
550