xref: /freebsd/contrib/sendmail/libsmdb/smdb.c (revision 0e97acdf58fe27b09c4824a474b0344daf997c5f)
1 /*
2 ** Copyright (c) 1999-2002 Proofpoint, 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 8.59 2013-11-22 20:51:49 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 *
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
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
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
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
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
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
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
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
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
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
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
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 *
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