2 * This is a data store backend for the Citadel server which uses Berkeley DB.
4 * Copyright (c) 1987-2021 by the citadel.org team
6 * This program is open source software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version 3.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 /*****************************************************************************
16 Tunable configuration parameters for the Berkeley DB back end
17 *****************************************************************************/
19 /* Citadel will checkpoint the db at the end of every session, but only if
20 * the specified number of kilobytes has been written, or if the specified
21 * number of minutes has passed, since the last checkpoint.
23 #define MAX_CHECKPOINT_KBYTES 256
24 #define MAX_CHECKPOINT_MINUTES 15
26 /*****************************************************************************/
37 #if DB_VERSION_MAJOR < 5
38 #error Citadel requires Berkeley DB v5.0 or newer. Please upgrade.
41 #include <libcitadel.h>
43 #include "ctdl_module.h"
45 #include "citserver.h"
48 static DB *dbp[MAXCDB]; /* One DB handle for each Citadel database */
49 static DB_ENV *dbenv; /* The DB environment (global) */
52 void cdb_abort(void) {
53 syslog(LOG_DEBUG, "db: citserver is stopping in order to prevent data loss. uid=%d gid=%d euid=%d egid=%d",
54 getuid(), getgid(), geteuid(), getegid()
60 /* Verbose logging callback */
61 void cdb_verbose_log(const DB_ENV * dbenv, const char *msg) {
62 if (!IsEmptyStr(msg)) {
63 syslog(LOG_DEBUG, "db: %s", msg);
68 /* Verbose logging callback */
69 void cdb_verbose_err(const DB_ENV * dbenv, const char *errpfx, const char *msg) {
70 syslog(LOG_ERR, "db: %s", msg);
74 /* wrapper for txn_abort() that logs/aborts on error */
75 static void txabort(DB_TXN *tid) {
78 ret = tid->abort(tid);
81 syslog(LOG_ERR, "db: txn_abort: %s", db_strerror(ret));
87 /* wrapper for txn_commit() that logs/aborts on error */
88 static void txcommit(DB_TXN *tid) {
91 ret = tid->commit(tid, 0);
94 syslog(LOG_ERR, "db: txn_commit: %s", db_strerror(ret));
100 /* wrapper for txn_begin() that logs/aborts on error */
101 static void txbegin(DB_TXN **tid) {
104 ret = dbenv->txn_begin(dbenv, NULL, tid, 0);
107 syslog(LOG_ERR, "db: txn_begin: %s", db_strerror(ret));
114 static void dbpanic(DB_ENV * env, int errval) {
115 syslog(LOG_ERR, "db: PANIC: %s", db_strerror(errval));
119 static void cclose(DBC * cursor) {
122 if ((ret = cursor->c_close(cursor))) {
123 syslog(LOG_ERR, "db: c_close: %s", db_strerror(ret));
129 static void bailIfCursor(DBC ** cursors, const char *msg) {
132 for (i = 0; i < MAXCDB; i++)
133 if (cursors[i] != NULL) {
134 syslog(LOG_ERR, "db: cursor still in progress on cdb %02x: %s", i, msg);
140 void cdb_check_handles(void) {
141 bailIfCursor(TSD->cursors, "in check_handles");
143 if (TSD->tid != NULL) {
144 syslog(LOG_ERR, "db: transaction still in progress!");
151 * Request a checkpoint of the database. Called once per minute by the thread manager.
153 void cdb_checkpoint(void) {
156 syslog(LOG_DEBUG, "db: -- checkpoint --");
157 ret = dbenv->txn_checkpoint(dbenv, MAX_CHECKPOINT_KBYTES, MAX_CHECKPOINT_MINUTES, 0);
160 syslog(LOG_ERR, "db: cdb_checkpoint() txn_checkpoint: %s", db_strerror(ret));
164 /* After a successful checkpoint, we can cull the unused logs */
165 if (CtdlGetConfigInt("c_auto_cull")) {
166 ret = dbenv->log_set_config(dbenv, DB_LOG_AUTO_REMOVE, 1);
169 ret = dbenv->log_set_config(dbenv, DB_LOG_AUTO_REMOVE, 0);
175 * Open the various databases we'll be using. Any database which
176 * does not exist should be created. Note that we don't need a
177 * critical section here, because there aren't any active threads
178 * manipulating the database yet.
180 void open_databases(void) {
185 int dbversion_major, dbversion_minor, dbversion_patch;
187 syslog(LOG_DEBUG, "db: open_databases() starting");
188 syslog(LOG_DEBUG, "db: Compiled libdb: %s", DB_VERSION_STRING);
189 syslog(LOG_DEBUG, "db: Linked libdb: %s", db_version(&dbversion_major, &dbversion_minor, &dbversion_patch));
190 syslog(LOG_DEBUG, "db: Linked zlib: %s", zlibVersion());
193 * Silently try to create the database subdirectory. If it's already there, no problem.
195 if ((mkdir(ctdl_db_dir, 0700) != 0) && (errno != EEXIST)) {
196 syslog(LOG_ERR, "db: unable to create database directory [%s]: %m", ctdl_db_dir);
198 if (chmod(ctdl_db_dir, 0700) != 0) {
199 syslog(LOG_ERR, "db: unable to set database directory permissions [%s]: %m", ctdl_db_dir);
201 if (chown(ctdl_db_dir, CTDLUID, (-1)) != 0) {
202 syslog(LOG_ERR, "db: unable to set the owner for [%s]: %m", ctdl_db_dir);
204 syslog(LOG_DEBUG, "db: Setting up DB environment");
205 // db_env_set_func_yield((int (*)(u_long, u_long))sched_yield);
206 ret = db_env_create(&dbenv, 0);
208 syslog(LOG_ERR, "db: db_env_create: %s", db_strerror(ret));
209 syslog(LOG_ERR, "db: exit code %d", ret);
212 dbenv->set_errpfx(dbenv, "citserver");
213 dbenv->set_paniccall(dbenv, dbpanic);
214 dbenv->set_errcall(dbenv, cdb_verbose_err);
215 dbenv->set_errpfx(dbenv, "ctdl");
216 dbenv->set_msgcall(dbenv, cdb_verbose_log);
217 dbenv->set_verbose(dbenv, DB_VERB_DEADLOCK, 1);
218 dbenv->set_verbose(dbenv, DB_VERB_RECOVERY, 1);
221 * We want to specify the shared memory buffer pool cachesize,
222 * but everything else is the default.
224 ret = dbenv->set_cachesize(dbenv, 0, 64 * 1024, 0);
226 syslog(LOG_ERR, "db: set_cachesize: %s", db_strerror(ret));
227 dbenv->close(dbenv, 0);
228 syslog(LOG_ERR, "db: exit code %d", ret);
232 if ((ret = dbenv->set_lk_detect(dbenv, DB_LOCK_DEFAULT))) {
233 syslog(LOG_ERR, "db: set_lk_detect: %s", db_strerror(ret));
234 dbenv->close(dbenv, 0);
235 syslog(LOG_ERR, "db: exit code %d", ret);
239 flags = DB_CREATE | DB_INIT_MPOOL | DB_PRIVATE | DB_INIT_TXN | DB_INIT_LOCK | DB_THREAD | DB_INIT_LOG;
240 syslog(LOG_DEBUG, "db: dbenv->open(dbenv, %s, %d, 0)", ctdl_db_dir, flags);
241 ret = dbenv->open(dbenv, ctdl_db_dir, flags, 0); // try opening the database cleanly
242 if (ret == DB_RUNRECOVERY) {
243 syslog(LOG_ERR, "db: dbenv->open: %s", db_strerror(ret));
244 syslog(LOG_ERR, "db: attempting recovery...");
246 ret = dbenv->open(dbenv, ctdl_db_dir, flags, 0); // try recovery
248 if (ret == DB_RUNRECOVERY) {
249 syslog(LOG_ERR, "db: dbenv->open: %s", db_strerror(ret));
250 syslog(LOG_ERR, "db: attempting catastrophic recovery...");
251 flags &= ~DB_RECOVER;
252 flags |= DB_RECOVER_FATAL;
253 ret = dbenv->open(dbenv, ctdl_db_dir, flags, 0); // try catastrophic recovery
256 syslog(LOG_ERR, "db: dbenv->open: %s", db_strerror(ret));
257 dbenv->close(dbenv, 0);
258 syslog(LOG_ERR, "db: exit code %d", ret);
262 syslog(LOG_INFO, "db: mounting databases");
263 for (i = 0; i < MAXCDB; ++i) {
264 ret = db_create(&dbp[i], dbenv, 0); // Create a database handle
266 syslog(LOG_ERR, "db: db_create: %s", db_strerror(ret));
267 syslog(LOG_ERR, "db: exit code %d", ret);
271 snprintf(dbfilename, sizeof dbfilename, "cdb.%02x", i); // table names by number
272 ret = dbp[i]->open(dbp[i], NULL, dbfilename, NULL, DB_BTREE, DB_CREATE | DB_AUTO_COMMIT | DB_THREAD, 0600);
274 syslog(LOG_ERR, "db: db_open[%02x]: %s", i, db_strerror(ret));
276 syslog(LOG_ERR, "db: You may need to tune your database; please read http://www.citadel.org/doku.php?id=faq:troubleshooting:out_of_lock_entries for more information.");
278 syslog(LOG_ERR, "db: exit code %d", ret);
286 * Make sure we own all the files, because in a few milliseconds we're going to drop root privs.
288 void cdb_chmod_data(void) {
291 char filename[PATH_MAX];
293 dp = opendir(ctdl_db_dir);
295 while (d = readdir(dp), d != NULL) {
296 if (d->d_name[0] != '.') {
297 snprintf(filename, sizeof filename, "%s/%s", ctdl_db_dir, d->d_name);
298 syslog(LOG_DEBUG, "db: chmod(%s, 0600) returned %d", filename, chmod(filename, 0600));
299 syslog(LOG_DEBUG, "db: chown(%s, CTDLUID, -1) returned %d",
300 filename, chown(filename, CTDLUID, (-1))
310 * Close all of the db database files we've opened. This can be done
311 * in a loop, since it's just a bunch of closes.
313 void close_databases(void) {
317 syslog(LOG_INFO, "db: performing final checkpoint");
318 if ((ret = dbenv->txn_checkpoint(dbenv, 0, 0, 0))) {
319 syslog(LOG_ERR, "db: txn_checkpoint: %s", db_strerror(ret));
322 syslog(LOG_INFO, "db: flushing the database logs");
323 if ((ret = dbenv->log_flush(dbenv, NULL))) {
324 syslog(LOG_ERR, "db: log_flush: %s", db_strerror(ret));
327 /* close the tables */
328 syslog(LOG_INFO, "db: closing databases");
329 for (i = 0; i < MAXCDB; ++i) {
330 syslog(LOG_INFO, "db: closing database %02x", i);
331 ret = dbp[i]->close(dbp[i], 0);
333 syslog(LOG_ERR, "db: db_close: %s", db_strerror(ret));
338 // This seemed nifty at the time but did anyone really look at it?
339 // #ifdef DB_STAT_ALL
340 // /* print some statistics... */
341 // dbenv->lock_stat_print(dbenv, DB_STAT_ALL);
344 /* Close the handle. */
345 ret = dbenv->close(dbenv, 0);
347 syslog(LOG_ERR, "db: DBENV->close: %s", db_strerror(ret));
353 * Decompress a database item if it was compressed on disk
355 void cdb_decompress_if_necessary(struct cdbdata *cdb) {
356 static int magic = COMPRESS_MAGIC;
358 if ((cdb == NULL) || (cdb->ptr == NULL) || (cdb->len < sizeof(magic)) || (memcmp(cdb->ptr, &magic, sizeof(magic)))) {
362 /* At this point we know we're looking at a compressed item. */
364 struct CtdlCompressHeader zheader;
365 char *uncompressed_data;
366 char *compressed_data;
367 uLongf destLen, sourceLen;
370 memset(&zheader, 0, sizeof(struct CtdlCompressHeader));
371 cplen = sizeof(struct CtdlCompressHeader);
372 if (sizeof(struct CtdlCompressHeader) > cdb->len) {
375 memcpy(&zheader, cdb->ptr, cplen);
377 compressed_data = cdb->ptr;
378 compressed_data += sizeof(struct CtdlCompressHeader);
380 sourceLen = (uLongf) zheader.compressed_len;
381 destLen = (uLongf) zheader.uncompressed_len;
382 uncompressed_data = malloc(zheader.uncompressed_len);
384 if (uncompress((Bytef *) uncompressed_data,
385 (uLongf *) & destLen, (const Bytef *) compressed_data, (uLong) sourceLen) != Z_OK) {
386 syslog(LOG_ERR, "db: uncompress() error");
391 cdb->len = (size_t) destLen;
392 cdb->ptr = uncompressed_data;
397 * Store a piece of data. Returns 0 if the operation was successful. If a
398 * key already exists it should be overwritten.
400 int cdb_store(int cdb, const void *ckey, int ckeylen, void *cdata, int cdatalen) {
405 struct CtdlCompressHeader zheader;
406 char *compressed_data = NULL;
408 size_t buffer_len = 0;
411 memset(&dkey, 0, sizeof(DBT));
412 memset(&ddata, 0, sizeof(DBT));
414 dkey.data = (void *) ckey;
415 ddata.size = cdatalen;
418 /* Only compress Visit and UseTable records. Everything else is uncompressed. */
419 if ((cdb == CDB_VISIT) || (cdb == CDB_USETABLE)) {
421 zheader.magic = COMPRESS_MAGIC;
422 zheader.uncompressed_len = cdatalen;
423 buffer_len = ((cdatalen * 101) / 100) + 100 + sizeof(struct CtdlCompressHeader);
424 destLen = (uLongf) buffer_len;
425 compressed_data = malloc(buffer_len);
426 if (compress2((Bytef *) (compressed_data + sizeof(struct CtdlCompressHeader)),
427 &destLen, (Bytef *) cdata, (uLongf) cdatalen, 1) != Z_OK) {
428 syslog(LOG_ERR, "db: compress2() error");
431 zheader.compressed_len = (size_t) destLen;
432 memcpy(compressed_data, &zheader, sizeof(struct CtdlCompressHeader));
433 ddata.size = (size_t) (sizeof(struct CtdlCompressHeader) + zheader.compressed_len);
434 ddata.data = compressed_data;
437 if (TSD->tid != NULL) {
438 ret = dbp[cdb]->put(dbp[cdb], // db
439 TSD->tid, // transaction ID
445 syslog(LOG_ERR, "db: cdb_store(%d): %s", cdb, db_strerror(ret));
449 free(compressed_data);
453 bailIfCursor(TSD->cursors, "attempt to write during r/o cursor");
458 if ((ret = dbp[cdb]->put(dbp[cdb], // db
459 tid, // transaction ID
463 if (ret == DB_LOCK_DEADLOCK) {
467 syslog(LOG_ERR, "db: cdb_store(%d): %s", cdb, db_strerror(ret));
473 free(compressed_data);
483 * Delete a piece of data. Returns 0 if the operation was successful.
485 int cdb_delete(int cdb, void *key, int keylen) {
490 memset(&dkey, 0, sizeof dkey);
494 if (TSD->tid != NULL) {
495 ret = dbp[cdb]->del(dbp[cdb], TSD->tid, &dkey, 0);
497 syslog(LOG_ERR, "db: cdb_delete(%d): %s", cdb, db_strerror(ret));
498 if (ret != DB_NOTFOUND) {
503 bailIfCursor(TSD->cursors, "attempt to delete during r/o cursor");
508 if ((ret = dbp[cdb]->del(dbp[cdb], tid, &dkey, 0)) && ret != DB_NOTFOUND) {
509 if (ret == DB_LOCK_DEADLOCK) {
513 syslog(LOG_ERR, "db: cdb_delete(%d): %s", cdb, db_strerror(ret));
524 static DBC *localcursor(int cdb) {
528 if (TSD->cursors[cdb] == NULL) {
529 ret = dbp[cdb]->cursor(dbp[cdb], TSD->tid, &curs, 0);
532 ret = TSD->cursors[cdb]->c_dup(TSD->cursors[cdb], &curs, DB_POSITION);
536 syslog(LOG_ERR, "db: localcursor: %s", db_strerror(ret));
545 * Fetch a piece of data. If not found, returns NULL. Otherwise, it returns
546 * a struct cdbdata which it is the caller's responsibility to free later on
547 * using the cdb_free() routine.
549 struct cdbdata *cdb_fetch(int cdb, const void *key, int keylen) {
551 syslog(LOG_DEBUG, "\x1b[35mdatabase: fetch from db %d a key of length %d\x1b[0m", cdb, keylen);
557 struct cdbdata *tempcdb;
561 memset(&dkey, 0, sizeof(DBT));
563 dkey.data = (void *) key;
565 if (TSD->tid != NULL) {
566 memset(&dret, 0, sizeof(DBT));
567 dret.flags = DB_DBT_MALLOC;
568 ret = dbp[cdb]->get(dbp[cdb], TSD->tid, &dkey, &dret, 0);
574 memset(&dret, 0, sizeof(DBT));
575 dret.flags = DB_DBT_MALLOC;
576 curs = localcursor(cdb);
577 ret = curs->c_get(curs, &dkey, &dret, DB_SET);
580 while (ret == DB_LOCK_DEADLOCK);
583 if ((ret != 0) && (ret != DB_NOTFOUND)) {
584 syslog(LOG_ERR, "db: cdb_fetch(%d): %s", cdb, db_strerror(ret));
592 tempcdb = (struct cdbdata *) malloc(sizeof(struct cdbdata));
594 if (tempcdb == NULL) {
595 syslog(LOG_ERR, "db: cdb_fetch: Cannot allocate memory for tempcdb");
597 return NULL; /* make it easier for static analysis... */
600 tempcdb->len = dret.size;
601 tempcdb->ptr = dret.data;
602 cdb_decompress_if_necessary(tempcdb);
609 * Free a cdbdata item.
611 * Note that we only free the 'ptr' portion if it is not NULL. This allows
612 * other code to assume ownership of that memory simply by storing the
613 * pointer elsewhere and then setting 'ptr' to NULL. cdb_free() will then
616 void cdb_free(struct cdbdata *cdb) {
624 void cdb_close_cursor(int cdb) {
625 if (TSD->cursors[cdb] != NULL) {
626 cclose(TSD->cursors[cdb]);
629 TSD->cursors[cdb] = NULL;
634 * Prepare for a sequential search of an entire database.
635 * (There is guaranteed to be no more than one traversal in
636 * progress per thread at any given time.)
638 void cdb_rewind(int cdb) {
641 if (TSD->cursors[cdb] != NULL) {
642 syslog(LOG_ERR, "db: cdb_rewind: must close cursor on database %d before reopening", cdb);
644 /* cclose(TSD->cursors[cdb]); */
648 * Now initialize the cursor
650 ret = dbp[cdb]->cursor(dbp[cdb], TSD->tid, &TSD->cursors[cdb], 0);
652 syslog(LOG_ERR, "db: cdb_rewind: db_cursor: %s", db_strerror(ret));
659 * Fetch the next item in a sequential search. Returns a pointer to a
660 * cdbdata structure, or NULL if we've hit the end.
662 struct cdbdata *cdb_next_item(int cdb) {
664 struct cdbdata *cdbret;
667 /* Initialize the key/data pair so the flags aren't set. */
668 memset(&key, 0, sizeof(key));
669 memset(&data, 0, sizeof(data));
670 data.flags = DB_DBT_MALLOC;
672 ret = TSD->cursors[cdb]->c_get(TSD->cursors[cdb], &key, &data, DB_NEXT);
675 if (ret != DB_NOTFOUND) {
676 syslog(LOG_ERR, "db: cdb_next_item(%d): %s", cdb, db_strerror(ret));
679 cdb_close_cursor(cdb);
680 return NULL; /* presumably, end of file */
683 cdbret = (struct cdbdata *) malloc(sizeof(struct cdbdata));
684 cdbret->len = data.size;
685 cdbret->ptr = data.data;
686 cdb_decompress_if_necessary(cdbret);
693 * Transaction-based stuff. I'm writing this as I bake cookies...
695 void cdb_begin_transaction(void) {
696 bailIfCursor(TSD->cursors, "can't begin transaction during r/o cursor");
698 if (TSD->tid != NULL) {
699 syslog(LOG_ERR, "db: cdb_begin_transaction: ERROR: nested transaction");
707 void cdb_end_transaction(void) {
710 for (i = 0; i < MAXCDB; i++)
711 if (TSD->cursors[i] != NULL) {
712 syslog(LOG_WARNING, "db: cdb_end_transaction: WARNING: cursor %d still open at transaction end", i);
713 cclose(TSD->cursors[i]);
714 TSD->cursors[i] = NULL;
717 if (TSD->tid == NULL) {
718 syslog(LOG_ERR, "db: cdb_end_transaction: ERROR: txcommit(NULL) !!");
729 * Truncate (delete every record)
731 void cdb_trunc(int cdb) {
736 if (TSD->tid != NULL) {
737 syslog(LOG_ERR, "db: cdb_trunc must not be called in a transaction.");
741 bailIfCursor(TSD->cursors, "attempt to write during r/o cursor");
746 if ((ret = dbp[cdb]->truncate(dbp[cdb], /* db */
747 NULL, /* transaction ID */
748 &count, /* #rows deleted */
750 if (ret == DB_LOCK_DEADLOCK) {
754 syslog(LOG_ERR, "db: cdb_truncate(%d): %s", cdb, db_strerror(ret));
756 syslog(LOG_ERR, "db: You may need to tune your database; please read http://www.citadel.org/doku.php?id=faq:troubleshooting:out_of_lock_entries for more information.");
768 * compact (defragment) the database , possibly returning space back to the underlying filesystem
770 void cdb_compact(void) {
774 syslog(LOG_DEBUG, "db: cdb_compact() started");
775 for (i = 0; i < MAXCDB; i++) {
776 syslog(LOG_DEBUG, "db: compacting database %d", i);
777 ret = dbp[i]->compact(dbp[i], NULL, NULL, NULL, NULL, DB_FREE_SPACE, NULL);
779 syslog(LOG_ERR, "db: compact: %s", db_strerror(ret));
782 syslog(LOG_DEBUG, "db: cdb_compact() finished");
786 // Has an item already been seen (is it in the CDB_USETABLE) ?
787 // Returns 0 if it hasn't, 1 if it has
788 // In either case, writes the item to the database for next time.
789 int CheckIfAlreadySeen(StrBuf *guid) {
792 struct cdbdata *cdbut;
794 syslog(LOG_DEBUG, "db: CheckIfAlreadySeen(%s)", ChrPtr(guid));
795 cdbut = cdb_fetch(CDB_USETABLE, SKEY(guid));
801 /* (Re)write the record, to update the timestamp. Zeroing it out makes it compress better. */
802 memset(&ut, 0, sizeof(struct UseTable));
803 memcpy(ut.ut_msgid, SKEY(guid));
804 ut.ut_timestamp = time(NULL);
805 cdb_store(CDB_USETABLE, SKEY(guid), &ut, sizeof(struct UseTable));
810 CTDL_MODULE_INIT(database)
813 // nothing to do here
816 /* return our module id for the log */