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 /*****************************************************************************/
38 #if DB_VERSION_MAJOR < 5
39 #error Citadel requires Berkeley DB v5.0 or newer. Please upgrade.
42 #include <libcitadel.h>
44 #include "ctdl_module.h"
46 #include "citserver.h"
49 static DB *dbp[MAXCDB]; /* One DB handle for each Citadel database */
50 static DB_ENV *dbenv; /* The DB environment (global) */
53 void cdb_abort(void) {
54 syslog(LOG_DEBUG, "db: citserver is stopping in order to prevent data loss. uid=%d gid=%d euid=%d egid=%d",
55 getuid(), getgid(), geteuid(), getegid()
61 /* Verbose logging callback */
62 void cdb_verbose_log(const DB_ENV * dbenv, const char *msg) {
63 if (!IsEmptyStr(msg)) {
64 syslog(LOG_DEBUG, "db: %s", msg);
69 /* Verbose logging callback */
70 void cdb_verbose_err(const DB_ENV * dbenv, const char *errpfx, const char *msg) {
71 syslog(LOG_ERR, "db: %s", msg);
75 /* wrapper for txn_abort() that logs/aborts on error */
76 static void txabort(DB_TXN *tid) {
79 ret = tid->abort(tid);
82 syslog(LOG_ERR, "db: txn_abort: %s", db_strerror(ret));
88 /* wrapper for txn_commit() that logs/aborts on error */
89 static void txcommit(DB_TXN *tid) {
92 ret = tid->commit(tid, 0);
95 syslog(LOG_ERR, "db: txn_commit: %s", db_strerror(ret));
101 /* wrapper for txn_begin() that logs/aborts on error */
102 static void txbegin(DB_TXN **tid) {
105 ret = dbenv->txn_begin(dbenv, NULL, tid, 0);
108 syslog(LOG_ERR, "db: txn_begin: %s", db_strerror(ret));
115 static void dbpanic(DB_ENV * env, int errval) {
116 syslog(LOG_ERR, "db: PANIC: %s", db_strerror(errval));
120 static void cclose(DBC * cursor) {
123 if ((ret = cursor->c_close(cursor))) {
124 syslog(LOG_ERR, "db: c_close: %s", db_strerror(ret));
130 static void bailIfCursor(DBC ** cursors, const char *msg) {
133 for (i = 0; i < MAXCDB; i++)
134 if (cursors[i] != NULL) {
135 syslog(LOG_ERR, "db: cursor still in progress on cdb %02x: %s", i, msg);
141 void cdb_check_handles(void) {
142 bailIfCursor(TSD->cursors, "in check_handles");
144 if (TSD->tid != NULL) {
145 syslog(LOG_ERR, "db: transaction still in progress!");
152 * Request a checkpoint of the database. Called once per minute by the thread manager.
154 void cdb_checkpoint(void) {
157 syslog(LOG_DEBUG, "db: -- checkpoint --");
158 ret = dbenv->txn_checkpoint(dbenv, MAX_CHECKPOINT_KBYTES, MAX_CHECKPOINT_MINUTES, 0);
161 syslog(LOG_ERR, "db: cdb_checkpoint() txn_checkpoint: %s", db_strerror(ret));
165 /* After a successful checkpoint, we can cull the unused logs */
166 if (CtdlGetConfigInt("c_auto_cull")) {
167 ret = dbenv->log_set_config(dbenv, DB_LOG_AUTO_REMOVE, 1);
170 ret = dbenv->log_set_config(dbenv, DB_LOG_AUTO_REMOVE, 0);
176 * Open the various databases we'll be using. Any database which
177 * does not exist should be created. Note that we don't need a
178 * critical section here, because there aren't any active threads
179 * manipulating the database yet.
181 void open_databases(void) {
186 int dbversion_major, dbversion_minor, dbversion_patch;
188 syslog(LOG_DEBUG, "db: open_databases() starting");
189 syslog(LOG_DEBUG, "db: Compiled libdb: %s", DB_VERSION_STRING);
190 syslog(LOG_DEBUG, "db: Linked libdb: %s", db_version(&dbversion_major, &dbversion_minor, &dbversion_patch));
191 syslog(LOG_DEBUG, "db: Linked zlib: %s", zlibVersion());
194 * Silently try to create the database subdirectory. If it's already there, no problem.
196 if ((mkdir(ctdl_db_dir, 0700) != 0) && (errno != EEXIST)) {
197 syslog(LOG_ERR, "db: unable to create database directory [%s]: %m", ctdl_db_dir);
199 if (chmod(ctdl_db_dir, 0700) != 0) {
200 syslog(LOG_ERR, "db: unable to set database directory permissions [%s]: %m", ctdl_db_dir);
202 if (chown(ctdl_db_dir, CTDLUID, (-1)) != 0) {
203 syslog(LOG_ERR, "db: unable to set the owner for [%s]: %m", ctdl_db_dir);
205 syslog(LOG_DEBUG, "db: Setting up DB environment");
206 // db_env_set_func_yield((int (*)(u_long, u_long))sched_yield);
207 ret = db_env_create(&dbenv, 0);
209 syslog(LOG_ERR, "db: db_env_create: %s", db_strerror(ret));
210 syslog(LOG_ERR, "db: exit code %d", ret);
213 dbenv->set_errpfx(dbenv, "citserver");
214 dbenv->set_paniccall(dbenv, dbpanic);
215 dbenv->set_errcall(dbenv, cdb_verbose_err);
216 dbenv->set_errpfx(dbenv, "ctdl");
217 dbenv->set_msgcall(dbenv, cdb_verbose_log);
218 dbenv->set_verbose(dbenv, DB_VERB_DEADLOCK, 1);
219 dbenv->set_verbose(dbenv, DB_VERB_RECOVERY, 1);
222 * We want to specify the shared memory buffer pool cachesize,
223 * but everything else is the default.
225 ret = dbenv->set_cachesize(dbenv, 0, 64 * 1024, 0);
227 syslog(LOG_ERR, "db: set_cachesize: %s", db_strerror(ret));
228 dbenv->close(dbenv, 0);
229 syslog(LOG_ERR, "db: exit code %d", ret);
233 if ((ret = dbenv->set_lk_detect(dbenv, DB_LOCK_DEFAULT))) {
234 syslog(LOG_ERR, "db: set_lk_detect: %s", db_strerror(ret));
235 dbenv->close(dbenv, 0);
236 syslog(LOG_ERR, "db: exit code %d", ret);
240 flags = DB_CREATE | DB_INIT_MPOOL | DB_PRIVATE | DB_INIT_TXN | DB_INIT_LOCK | DB_THREAD | DB_INIT_LOG;
241 syslog(LOG_DEBUG, "db: dbenv->open(dbenv, %s, %d, 0)", ctdl_db_dir, flags);
242 ret = dbenv->open(dbenv, ctdl_db_dir, flags, 0); // try opening the database cleanly
243 if (ret == DB_RUNRECOVERY) {
244 syslog(LOG_ERR, "db: dbenv->open: %s", db_strerror(ret));
245 syslog(LOG_ERR, "db: attempting recovery...");
247 ret = dbenv->open(dbenv, ctdl_db_dir, flags, 0); // try recovery
249 if (ret == DB_RUNRECOVERY) {
250 syslog(LOG_ERR, "db: dbenv->open: %s", db_strerror(ret));
251 syslog(LOG_ERR, "db: attempting catastrophic recovery...");
252 flags &= ~DB_RECOVER;
253 flags |= DB_RECOVER_FATAL;
254 ret = dbenv->open(dbenv, ctdl_db_dir, flags, 0); // try catastrophic recovery
257 syslog(LOG_ERR, "db: dbenv->open: %s", db_strerror(ret));
258 dbenv->close(dbenv, 0);
259 syslog(LOG_ERR, "db: exit code %d", ret);
263 syslog(LOG_INFO, "db: mounting databases");
264 for (i = 0; i < MAXCDB; ++i) {
265 ret = db_create(&dbp[i], dbenv, 0); // Create a database handle
267 syslog(LOG_ERR, "db: db_create: %s", db_strerror(ret));
268 syslog(LOG_ERR, "db: exit code %d", ret);
272 snprintf(dbfilename, sizeof dbfilename, "cdb.%02x", i); // table names by number
273 ret = dbp[i]->open(dbp[i], NULL, dbfilename, NULL, DB_BTREE, DB_CREATE | DB_AUTO_COMMIT | DB_THREAD, 0600);
275 syslog(LOG_ERR, "db: db_open[%02x]: %s", i, db_strerror(ret));
277 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.");
279 syslog(LOG_ERR, "db: exit code %d", ret);
287 * Make sure we own all the files, because in a few milliseconds we're going to drop root privs.
289 void cdb_chmod_data(void) {
292 char filename[PATH_MAX];
294 dp = opendir(ctdl_db_dir);
296 while (d = readdir(dp), d != NULL) {
297 if (d->d_name[0] != '.') {
298 snprintf(filename, sizeof filename, "%s/%s", ctdl_db_dir, d->d_name);
299 syslog(LOG_DEBUG, "db: chmod(%s, 0600) returned %d", filename, chmod(filename, 0600));
300 syslog(LOG_DEBUG, "db: chown(%s, CTDLUID, -1) returned %d",
301 filename, chown(filename, CTDLUID, (-1))
311 * Close all of the db database files we've opened. This can be done
312 * in a loop, since it's just a bunch of closes.
314 void close_databases(void) {
318 syslog(LOG_INFO, "db: performing final checkpoint");
319 if ((ret = dbenv->txn_checkpoint(dbenv, 0, 0, 0))) {
320 syslog(LOG_ERR, "db: txn_checkpoint: %s", db_strerror(ret));
323 syslog(LOG_INFO, "db: flushing the database logs");
324 if ((ret = dbenv->log_flush(dbenv, NULL))) {
325 syslog(LOG_ERR, "db: log_flush: %s", db_strerror(ret));
328 /* close the tables */
329 syslog(LOG_INFO, "db: closing databases");
330 for (i = 0; i < MAXCDB; ++i) {
331 syslog(LOG_INFO, "db: closing database %02x", i);
332 ret = dbp[i]->close(dbp[i], 0);
334 syslog(LOG_ERR, "db: db_close: %s", db_strerror(ret));
339 // This seemed nifty at the time but did anyone really look at it?
340 // #ifdef DB_STAT_ALL
341 // /* print some statistics... */
342 // dbenv->lock_stat_print(dbenv, DB_STAT_ALL);
345 /* Close the handle. */
346 ret = dbenv->close(dbenv, 0);
348 syslog(LOG_ERR, "db: DBENV->close: %s", db_strerror(ret));
354 * Decompress a database item if it was compressed on disk
356 void cdb_decompress_if_necessary(struct cdbdata *cdb) {
357 static int magic = COMPRESS_MAGIC;
359 if ((cdb == NULL) || (cdb->ptr == NULL) || (cdb->len < sizeof(magic)) || (memcmp(cdb->ptr, &magic, sizeof(magic)))) {
363 /* At this point we know we're looking at a compressed item. */
365 struct CtdlCompressHeader zheader;
366 char *uncompressed_data;
367 char *compressed_data;
368 uLongf destLen, sourceLen;
371 memset(&zheader, 0, sizeof(struct CtdlCompressHeader));
372 cplen = sizeof(struct CtdlCompressHeader);
373 if (sizeof(struct CtdlCompressHeader) > cdb->len) {
376 memcpy(&zheader, cdb->ptr, cplen);
378 compressed_data = cdb->ptr;
379 compressed_data += sizeof(struct CtdlCompressHeader);
381 sourceLen = (uLongf) zheader.compressed_len;
382 destLen = (uLongf) zheader.uncompressed_len;
383 uncompressed_data = malloc(zheader.uncompressed_len);
385 if (uncompress((Bytef *) uncompressed_data,
386 (uLongf *) & destLen, (const Bytef *) compressed_data, (uLong) sourceLen) != Z_OK) {
387 syslog(LOG_ERR, "db: uncompress() error");
392 cdb->len = (size_t) destLen;
393 cdb->ptr = uncompressed_data;
398 * Store a piece of data. Returns 0 if the operation was successful. If a
399 * key already exists it should be overwritten.
401 int cdb_store(int cdb, const void *ckey, int ckeylen, void *cdata, int cdatalen) {
406 struct CtdlCompressHeader zheader;
407 char *compressed_data = NULL;
409 size_t buffer_len = 0;
412 memset(&dkey, 0, sizeof(DBT));
413 memset(&ddata, 0, sizeof(DBT));
415 dkey.data = (void *) ckey;
416 ddata.size = cdatalen;
419 /* Only compress Visit and UseTable records. Everything else is uncompressed. */
420 if ((cdb == CDB_VISIT) || (cdb == CDB_USETABLE)) {
422 zheader.magic = COMPRESS_MAGIC;
423 zheader.uncompressed_len = cdatalen;
424 buffer_len = ((cdatalen * 101) / 100) + 100 + sizeof(struct CtdlCompressHeader);
425 destLen = (uLongf) buffer_len;
426 compressed_data = malloc(buffer_len);
427 if (compress2((Bytef *) (compressed_data + sizeof(struct CtdlCompressHeader)),
428 &destLen, (Bytef *) cdata, (uLongf) cdatalen, 1) != Z_OK) {
429 syslog(LOG_ERR, "db: compress2() error");
432 zheader.compressed_len = (size_t) destLen;
433 memcpy(compressed_data, &zheader, sizeof(struct CtdlCompressHeader));
434 ddata.size = (size_t) (sizeof(struct CtdlCompressHeader) + zheader.compressed_len);
435 ddata.data = compressed_data;
438 if (TSD->tid != NULL) {
439 ret = dbp[cdb]->put(dbp[cdb], // db
440 TSD->tid, // transaction ID
446 syslog(LOG_ERR, "db: cdb_store(%d): %s", cdb, db_strerror(ret));
450 free(compressed_data);
454 bailIfCursor(TSD->cursors, "attempt to write during r/o cursor");
459 if ((ret = dbp[cdb]->put(dbp[cdb], // db
460 tid, // transaction ID
464 if (ret == DB_LOCK_DEADLOCK) {
468 syslog(LOG_ERR, "db: cdb_store(%d): %s", cdb, db_strerror(ret));
474 free(compressed_data);
484 * Delete a piece of data. Returns 0 if the operation was successful.
486 int cdb_delete(int cdb, void *key, int keylen) {
491 memset(&dkey, 0, sizeof dkey);
495 if (TSD->tid != NULL) {
496 ret = dbp[cdb]->del(dbp[cdb], TSD->tid, &dkey, 0);
498 syslog(LOG_ERR, "db: cdb_delete(%d): %s", cdb, db_strerror(ret));
499 if (ret != DB_NOTFOUND) {
504 bailIfCursor(TSD->cursors, "attempt to delete during r/o cursor");
509 if ((ret = dbp[cdb]->del(dbp[cdb], tid, &dkey, 0)) && ret != DB_NOTFOUND) {
510 if (ret == DB_LOCK_DEADLOCK) {
514 syslog(LOG_ERR, "db: cdb_delete(%d): %s", cdb, db_strerror(ret));
525 static DBC *localcursor(int cdb) {
529 if (TSD->cursors[cdb] == NULL) {
530 ret = dbp[cdb]->cursor(dbp[cdb], TSD->tid, &curs, 0);
533 ret = TSD->cursors[cdb]->c_dup(TSD->cursors[cdb], &curs, DB_POSITION);
537 syslog(LOG_ERR, "db: localcursor: %s", db_strerror(ret));
546 * Fetch a piece of data. If not found, returns NULL. Otherwise, it returns
547 * a struct cdbdata which it is the caller's responsibility to free later on
548 * using the cdb_free() routine.
550 struct cdbdata *cdb_fetch(int cdb, const void *key, int keylen) {
551 struct cdbdata *tempcdb;
555 memset(&dkey, 0, sizeof(DBT));
557 dkey.data = (void *) key;
559 if (TSD->tid != NULL) {
560 memset(&dret, 0, sizeof(DBT));
561 dret.flags = DB_DBT_MALLOC;
562 ret = dbp[cdb]->get(dbp[cdb], TSD->tid, &dkey, &dret, 0); // crashing here
567 memset(&dret, 0, sizeof(DBT));
568 dret.flags = DB_DBT_MALLOC;
569 curs = localcursor(cdb);
570 ret = curs->c_get(curs, &dkey, &dret, DB_SET);
573 while (ret == DB_LOCK_DEADLOCK);
576 if ((ret != 0) && (ret != DB_NOTFOUND)) {
577 syslog(LOG_ERR, "db: cdb_fetch(%d): %s", cdb, db_strerror(ret));
585 tempcdb = (struct cdbdata *) malloc(sizeof(struct cdbdata));
587 if (tempcdb == NULL) {
588 syslog(LOG_ERR, "db: cdb_fetch: Cannot allocate memory for tempcdb");
590 return NULL; /* make it easier for static analysis... */
592 tempcdb->len = dret.size;
593 tempcdb->ptr = dret.data;
594 cdb_decompress_if_necessary(tempcdb);
601 * Free a cdbdata item.
603 * Note that we only free the 'ptr' portion if it is not NULL. This allows
604 * other code to assume ownership of that memory simply by storing the
605 * pointer elsewhere and then setting 'ptr' to NULL. cdb_free() will then
608 void cdb_free(struct cdbdata *cdb) {
616 void cdb_close_cursor(int cdb) {
617 if (TSD->cursors[cdb] != NULL) {
618 cclose(TSD->cursors[cdb]);
621 TSD->cursors[cdb] = NULL;
626 * Prepare for a sequential search of an entire database.
627 * (There is guaranteed to be no more than one traversal in
628 * progress per thread at any given time.)
630 void cdb_rewind(int cdb) {
633 if (TSD->cursors[cdb] != NULL) {
634 syslog(LOG_ERR, "db: cdb_rewind: must close cursor on database %d before reopening", cdb);
636 /* cclose(TSD->cursors[cdb]); */
640 * Now initialize the cursor
642 ret = dbp[cdb]->cursor(dbp[cdb], TSD->tid, &TSD->cursors[cdb], 0);
644 syslog(LOG_ERR, "db: cdb_rewind: db_cursor: %s", db_strerror(ret));
651 * Fetch the next item in a sequential search. Returns a pointer to a
652 * cdbdata structure, or NULL if we've hit the end.
654 struct cdbdata *cdb_next_item(int cdb) {
656 struct cdbdata *cdbret;
659 /* Initialize the key/data pair so the flags aren't set. */
660 memset(&key, 0, sizeof(key));
661 memset(&data, 0, sizeof(data));
662 data.flags = DB_DBT_MALLOC;
664 ret = TSD->cursors[cdb]->c_get(TSD->cursors[cdb], &key, &data, DB_NEXT);
667 if (ret != DB_NOTFOUND) {
668 syslog(LOG_ERR, "db: cdb_next_item(%d): %s", cdb, db_strerror(ret));
671 cdb_close_cursor(cdb);
672 return NULL; /* presumably, end of file */
675 cdbret = (struct cdbdata *) malloc(sizeof(struct cdbdata));
676 cdbret->len = data.size;
677 cdbret->ptr = data.data;
678 cdb_decompress_if_necessary(cdbret);
685 * Transaction-based stuff. I'm writing this as I bake cookies...
687 void cdb_begin_transaction(void) {
688 bailIfCursor(TSD->cursors, "can't begin transaction during r/o cursor");
690 if (TSD->tid != NULL) {
691 syslog(LOG_ERR, "db: cdb_begin_transaction: ERROR: nested transaction");
699 void cdb_end_transaction(void) {
702 for (i = 0; i < MAXCDB; i++)
703 if (TSD->cursors[i] != NULL) {
704 syslog(LOG_WARNING, "db: cdb_end_transaction: WARNING: cursor %d still open at transaction end", i);
705 cclose(TSD->cursors[i]);
706 TSD->cursors[i] = NULL;
709 if (TSD->tid == NULL) {
710 syslog(LOG_ERR, "db: cdb_end_transaction: ERROR: txcommit(NULL) !!");
721 * Truncate (delete every record)
723 void cdb_trunc(int cdb) {
728 if (TSD->tid != NULL) {
729 syslog(LOG_ERR, "db: cdb_trunc must not be called in a transaction.");
733 bailIfCursor(TSD->cursors, "attempt to write during r/o cursor");
738 if ((ret = dbp[cdb]->truncate(dbp[cdb], /* db */
739 NULL, /* transaction ID */
740 &count, /* #rows deleted */
742 if (ret == DB_LOCK_DEADLOCK) {
746 syslog(LOG_ERR, "db: cdb_truncate(%d): %s", cdb, db_strerror(ret));
748 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.");
760 * compact (defragment) the database , possibly returning space back to the underlying filesystem
762 void cdb_compact(void) {
766 syslog(LOG_DEBUG, "db: cdb_compact() started");
767 for (i = 0; i < MAXCDB; i++) {
768 syslog(LOG_DEBUG, "db: compacting database %d", i);
769 ret = dbp[i]->compact(dbp[i], NULL, NULL, NULL, NULL, DB_FREE_SPACE, NULL);
771 syslog(LOG_ERR, "db: compact: %s", db_strerror(ret));
774 syslog(LOG_DEBUG, "db: cdb_compact() finished");
778 // Has an item already been seen (is it in the CDB_USETABLE) ?
779 // Returns 0 if it hasn't, 1 if it has
780 // In either case, writes the item to the database for next time.
781 int CheckIfAlreadySeen(StrBuf *guid) {
784 struct cdbdata *cdbut;
786 syslog(LOG_DEBUG, "db: CheckIfAlreadySeen(%s)", ChrPtr(guid));
787 cdbut = cdb_fetch(CDB_USETABLE, SKEY(guid));
793 /* (Re)write the record, to update the timestamp. Zeroing it out makes it compress better. */
794 memset(&ut, 0, sizeof(struct UseTable));
795 memcpy(ut.ut_msgid, SKEY(guid));
796 ut.ut_timestamp = time(NULL);
797 cdb_store(CDB_USETABLE, SKEY(guid), &ut, sizeof(struct UseTable));
802 CTDL_MODULE_INIT(database)
805 // nothing to do here
808 /* return our module id for the log */