+++ /dev/null
- /*
- Unix SMB/CIFS implementation.
-
- trivial database library
-
- Copyright (C) Andrew Tridgell 1999-2005
- Copyright (C) Paul `Rusty' Russell 2000
- Copyright (C) Jeremy Allison 2000-2003
-
- ** NOTE! The following LGPL license applies to the tdb
- ** library. This does NOT imply that all of Samba is released
- ** under the LGPL
-
- This library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 3 of the License, or (at your option) any later version.
-
- This library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with this library; if not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include "tdb_private.h"
-
-/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
-static struct tdb_context *tdbs = NULL;
-
-/* We use two hashes to double-check they're using the right hash function. */
-void tdb_header_hash(struct tdb_context *tdb,
- uint32_t *magic1_hash, uint32_t *magic2_hash)
-{
- TDB_DATA hash_key;
- uint32_t tdb_magic = TDB_MAGIC;
-
- hash_key.dptr = (unsigned char *)TDB_MAGIC_FOOD;
- hash_key.dsize = sizeof(TDB_MAGIC_FOOD);
- *magic1_hash = tdb->hash_fn(&hash_key);
-
- hash_key.dptr = CONVERT(tdb_magic);
- hash_key.dsize = sizeof(tdb_magic);
- *magic2_hash = tdb->hash_fn(&hash_key);
-
- /* Make sure at least one hash is non-zero! */
- if (*magic1_hash == 0 && *magic2_hash == 0)
- *magic1_hash = 1;
-}
-
-/* initialise a new database with a specified hash size */
-static int tdb_new_database(struct tdb_context *tdb, int hash_size)
-{
- struct tdb_header *newdb;
- size_t size;
- int ret = -1;
- ssize_t written;
-
- /* We make it up in memory, then write it out if not internal */
- size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off_t);
- if (!(newdb = (struct tdb_header *)calloc(size, 1))) {
- tdb->ecode = TDB_ERR_OOM;
- return -1;
- }
-
- /* Fill in the header */
- newdb->version = TDB_VERSION;
- newdb->hash_size = hash_size;
-
- tdb_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
-
- /* Make sure older tdbs (which don't check the magic hash fields)
- * will refuse to open this TDB. */
- if (tdb->flags & TDB_INCOMPATIBLE_HASH)
- newdb->rwlocks = TDB_HASH_RWLOCK_MAGIC;
-
- if (tdb->flags & TDB_INTERNAL) {
- tdb->map_size = size;
- tdb->map_ptr = (char *)newdb;
- memcpy(&tdb->header, newdb, sizeof(tdb->header));
- /* Convert the `ondisk' version if asked. */
- CONVERT(*newdb);
- return 0;
- }
- if (lseek(tdb->fd, 0, SEEK_SET) == -1)
- goto fail;
-
- if (ftruncate(tdb->fd, 0) == -1)
- goto fail;
-
- /* This creates an endian-converted header, as if read from disk */
- CONVERT(*newdb);
- memcpy(&tdb->header, newdb, sizeof(tdb->header));
- /* Don't endian-convert the magic food! */
- memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
- /* we still have "ret == -1" here */
- written = write(tdb->fd, newdb, size);
- if (written == size) {
- ret = 0;
- } else if (written != -1) {
- /* call write once again, this usually should return -1 and
- * set errno appropriately */
- size -= written;
- written = write(tdb->fd, newdb+written, size);
- if (written == size) {
- ret = 0;
- } else if (written >= 0) {
- /* a second incomplete write - we give up.
- * guessing the errno... */
- errno = ENOSPC;
- }
- }
-
- fail:
- SAFE_FREE(newdb);
- return ret;
-}
-
-
-
-static int tdb_already_open(dev_t device,
- ino_t ino)
-{
- struct tdb_context *i;
-
- for (i = tdbs; i; i = i->next) {
- if (i->device == device && i->inode == ino) {
- return 1;
- }
- }
-
- return 0;
-}
-
-/* open the database, creating it if necessary
-
- The open_flags and mode are passed straight to the open call on the
- database file. A flags value of O_WRONLY is invalid. The hash size
- is advisory, use zero for a default value.
-
- Return is NULL on error, in which case errno is also set. Don't
- try to call tdb_error or tdb_errname, just do strerror(errno).
-
- @param name may be NULL for internal databases. */
-struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags,
- int open_flags, mode_t mode)
-{
- return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL);
-}
-
-/* a default logging function */
-static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_FMT(3, 4);
-static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
-{
-}
-
-static bool check_header_hash(struct tdb_context *tdb,
- bool default_hash, uint32_t *m1, uint32_t *m2)
-{
- tdb_header_hash(tdb, m1, m2);
- if (tdb->header.magic1_hash == *m1 &&
- tdb->header.magic2_hash == *m2) {
- return true;
- }
-
- /* If they explicitly set a hash, always respect it. */
- if (!default_hash)
- return false;
-
- /* Otherwise, try the other inbuilt hash. */
- if (tdb->hash_fn == tdb_old_hash)
- tdb->hash_fn = tdb_jenkins_hash;
- else
- tdb->hash_fn = tdb_old_hash;
- return check_header_hash(tdb, false, m1, m2);
-}
-
-struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
- int open_flags, mode_t mode,
- const struct tdb_logging_context *log_ctx,
- tdb_hash_func hash_fn)
-{
- struct tdb_context *tdb;
- struct stat st;
- int rev = 0, locked = 0;
- unsigned char *vp;
- uint32_t vertest;
- unsigned v;
- const char *hash_alg;
- uint32_t magic1, magic2;
-
- if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
- /* Can't log this */
- errno = ENOMEM;
- goto fail;
- }
- tdb_io_init(tdb);
- tdb->fd = -1;
-#ifdef TDB_TRACE
- tdb->tracefd = -1;
-#endif
- tdb->name = NULL;
- tdb->map_ptr = NULL;
- tdb->flags = tdb_flags;
- tdb->open_flags = open_flags;
- if (log_ctx) {
- tdb->log = *log_ctx;
- } else {
- tdb->log.log_fn = null_log_fn;
- tdb->log.log_private = NULL;
- }
-
- if (hash_fn) {
- tdb->hash_fn = hash_fn;
- hash_alg = "the user defined";
- } else {
- /* This controls what we use when creating a tdb. */
- if (tdb->flags & TDB_INCOMPATIBLE_HASH) {
- tdb->hash_fn = tdb_jenkins_hash;
- } else {
- tdb->hash_fn = tdb_old_hash;
- }
- hash_alg = "either default";
- }
-
- /* cache the page size */
- tdb->page_size = getpagesize();
- if (tdb->page_size <= 0) {
- tdb->page_size = 0x2000;
- }
-
- tdb->max_dead_records = (tdb_flags & TDB_VOLATILE) ? 5 : 0;
-
- if ((open_flags & O_ACCMODE) == O_WRONLY) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n",
- name));
- errno = EINVAL;
- goto fail;
- }
-
- if (hash_size == 0)
- hash_size = DEFAULT_HASH_SIZE;
- if ((open_flags & O_ACCMODE) == O_RDONLY) {
- tdb->read_only = 1;
- /* read only databases don't do locking or clear if first */
- tdb->flags |= TDB_NOLOCK;
- tdb->flags &= ~TDB_CLEAR_IF_FIRST;
- }
-
- if ((tdb->flags & TDB_ALLOW_NESTING) &&
- (tdb->flags & TDB_DISALLOW_NESTING)) {
- tdb->ecode = TDB_ERR_NESTING;
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
- "allow_nesting and disallow_nesting are not allowed together!"));
- errno = EINVAL;
- goto fail;
- }
-
- /*
- * TDB_DISALLOW_NESTING is the default behavior.
- */
- if (!(tdb->flags & TDB_ALLOW_NESTING)) {
- tdb->flags |= TDB_DISALLOW_NESTING;
- }
-
- /* internal databases don't mmap or lock, and start off cleared */
- if (tdb->flags & TDB_INTERNAL) {
- tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
- tdb->flags &= ~TDB_CLEAR_IF_FIRST;
- if (tdb_new_database(tdb, hash_size) != 0) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!"));
- goto fail;
- }
- goto internal;
- }
-
- if ((tdb->fd = open(name, open_flags, mode)) == -1) {
- TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_open_ex: could not open file %s: %s\n",
- name, strerror(errno)));
- goto fail; /* errno set by open(2) */
- }
-
- /* on exec, don't inherit the fd */
- v = fcntl(tdb->fd, F_GETFD, 0);
- fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
-
- /* ensure there is only one process initialising at once */
- if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get open lock on %s: %s\n",
- name, strerror(errno)));
- goto fail; /* errno set by tdb_brlock */
- }
-
- /* we need to zero database if we are the only one with it open */
- if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
- (!tdb->read_only) &&
- (locked = (tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
- open_flags |= O_CREAT;
- if (ftruncate(tdb->fd, 0) == -1) {
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
- "failed to truncate %s: %s\n",
- name, strerror(errno)));
- goto fail; /* errno set by ftruncate */
- }
- }
-
- errno = 0;
- if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
- || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0) {
- if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
- if (errno == 0) {
- errno = EIO; /* ie bad format or something */
- }
- goto fail;
- }
- rev = (tdb->flags & TDB_CONVERT);
- } else if (tdb->header.version != TDB_VERSION
- && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION)))) {
- /* wrong version */
- errno = EIO;
- goto fail;
- }
- vp = (unsigned char *)&tdb->header.version;
- vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) |
- (((uint32_t)vp[2]) << 8) | (uint32_t)vp[3];
- tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
- if (!rev)
- tdb->flags &= ~TDB_CONVERT;
- else {
- tdb->flags |= TDB_CONVERT;
- tdb_convert(&tdb->header, sizeof(tdb->header));
- }
- if (fstat(tdb->fd, &st) == -1)
- goto fail;
-
- if (tdb->header.rwlocks != 0 &&
- tdb->header.rwlocks != TDB_HASH_RWLOCK_MAGIC) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n"));
- goto fail;
- }
-
- if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
- /* older TDB without magic hash references */
- tdb->hash_fn = tdb_old_hash;
- } else if (!check_header_hash(tdb, !hash_fn, &magic1, &magic2)) {
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
- "%s was not created with %s hash function we are using\n"
- "magic1_hash[0x%08X %s 0x%08X] "
- "magic2_hash[0x%08X %s 0x%08X]\n",
- name, hash_alg,
- tdb->header.magic1_hash,
- (tdb->header.magic1_hash == magic1) ? "==" : "!=",
- magic1,
- tdb->header.magic2_hash,
- (tdb->header.magic2_hash == magic2) ? "==" : "!=",
- magic2));
- errno = EINVAL;
- goto fail;
- }
-
- /* Is it already in the open list? If so, fail. */
- if (tdb_already_open(st.st_dev, st.st_ino)) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
- "%s (%d,%d) is already open in this process\n",
- name, (int)st.st_dev, (int)st.st_ino));
- errno = EBUSY;
- goto fail;
- }
-
- if (!(tdb->name = (char *)strdup(name))) {
- errno = ENOMEM;
- goto fail;
- }
-
- tdb->map_size = st.st_size;
- tdb->device = st.st_dev;
- tdb->inode = st.st_ino;
- tdb_mmap(tdb);
- if (locked) {
- if (tdb_nest_unlock(tdb, ACTIVE_LOCK, F_WRLCK, false) == -1) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
- "failed to take ACTIVE_LOCK on %s: %s\n",
- name, strerror(errno)));
- goto fail;
- }
-
- }
-
- /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
- we didn't get the initial exclusive lock as we need to let all other
- users know we're using it. */
-
- if (tdb_flags & TDB_CLEAR_IF_FIRST) {
- /* leave this lock in place to indicate it's in use */
- if (tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
- goto fail;
- }
- }
-
- /* if needed, run recovery */
- if (tdb_transaction_recover(tdb) == -1) {
- goto fail;
- }
-
-#ifdef TDB_TRACE
- {
- char tracefile[strlen(name) + 32];
-
- snprintf(tracefile, sizeof(tracefile),
- "%s.trace.%li", name, (long)getpid());
- tdb->tracefd = open(tracefile, O_WRONLY|O_CREAT|O_EXCL, 0600);
- if (tdb->tracefd >= 0) {
- tdb_enable_seqnum(tdb);
- tdb_trace_open(tdb, "tdb_open", hash_size, tdb_flags,
- open_flags);
- } else
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to open trace file %s!\n", tracefile));
- }
-#endif
-
- internal:
- /* Internal (memory-only) databases skip all the code above to
- * do with disk files, and resume here by releasing their
- * open lock and hooking into the active list. */
- if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {
- goto fail;
- }
- tdb->next = tdbs;
- tdbs = tdb;
- return tdb;
-
- fail:
- { int save_errno = errno;
-
- if (!tdb)
- return NULL;
-
-#ifdef TDB_TRACE
- close(tdb->tracefd);
-#endif
- if (tdb->map_ptr) {
- if (tdb->flags & TDB_INTERNAL)
- SAFE_FREE(tdb->map_ptr);
- else
- tdb_munmap(tdb);
- }
- SAFE_FREE(tdb->name);
- if (tdb->fd != -1)
- if (close(tdb->fd) != 0)
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
- SAFE_FREE(tdb->lockrecs);
- SAFE_FREE(tdb);
- errno = save_errno;
- return NULL;
- }
-}
-
-/*
- * Set the maximum number of dead records per hash chain
- */
-
-void tdb_set_max_dead(struct tdb_context *tdb, int max_dead)
-{
- tdb->max_dead_records = max_dead;
-}
-
-/**
- * Close a database.
- *
- * @returns -1 for error; 0 for success.
- **/
-int tdb_close(struct tdb_context *tdb)
-{
- struct tdb_context **i;
- int ret = 0;
-
- if (tdb->transaction) {
- tdb_transaction_cancel(tdb);
- }
- tdb_trace(tdb, "tdb_close");
-
- if (tdb->map_ptr) {
- if (tdb->flags & TDB_INTERNAL)
- SAFE_FREE(tdb->map_ptr);
- else
- tdb_munmap(tdb);
- }
- SAFE_FREE(tdb->name);
- if (tdb->fd != -1) {
- ret = close(tdb->fd);
- tdb->fd = -1;
- }
- SAFE_FREE(tdb->lockrecs);
-
- /* Remove from contexts list */
- for (i = &tdbs; *i; i = &(*i)->next) {
- if (*i == tdb) {
- *i = tdb->next;
- break;
- }
- }
-
-#ifdef TDB_TRACE
- close(tdb->tracefd);
-#endif
- memset(tdb, 0, sizeof(*tdb));
- SAFE_FREE(tdb);
-
- return ret;
-}
-
-/* register a loging function */
-void tdb_set_logging_function(struct tdb_context *tdb,
- const struct tdb_logging_context *log_ctx)
-{
- tdb->log = *log_ctx;
-}
-
-void *tdb_get_logging_private(struct tdb_context *tdb)
-{
- return tdb->log.log_private;
-}
-
-static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
-{
- struct stat st;
-
- if (tdb->flags & TDB_INTERNAL) {
- return 0; /* Nothing to do. */
- }
-
- if (tdb_have_extra_locks(tdb)) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
- goto fail;
- }
-
- if (tdb->transaction != 0) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed inside a transaction\n"));
- goto fail;
- }
-
- if (tdb_munmap(tdb) != 0) {
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
- goto fail;
- }
- if (close(tdb->fd) != 0)
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
- tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
- if (tdb->fd == -1) {
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
- goto fail;
- }
- if (fstat(tdb->fd, &st) != 0) {
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
- goto fail;
- }
- if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: file dev/inode has changed!\n"));
- goto fail;
- }
- tdb_mmap(tdb);
-
- /* We may still think we hold the active lock. */
- tdb->num_lockrecs = 0;
- SAFE_FREE(tdb->lockrecs);
-
- if (active_lock && tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
- goto fail;
- }
-
- return 0;
-
-fail:
- tdb_close(tdb);
- return -1;
-}
-
-/* reopen a tdb - this can be used after a fork to ensure that we have an independent
- seek pointer from our parent and to re-establish locks */
-int tdb_reopen(struct tdb_context *tdb)
-{
- return tdb_reopen_internal(tdb, tdb->flags & TDB_CLEAR_IF_FIRST);
-}
-
-/* reopen all tdb's */
-int tdb_reopen_all(int parent_longlived)
-{
- struct tdb_context *tdb;
-
- for (tdb=tdbs; tdb; tdb = tdb->next) {
- bool active_lock = (tdb->flags & TDB_CLEAR_IF_FIRST);
-
- /*
- * If the parent is longlived (ie. a
- * parent daemon architecture), we know
- * it will keep it's active lock on a
- * tdb opened with CLEAR_IF_FIRST. Thus
- * for child processes we don't have to
- * add an active lock. This is essential
- * to improve performance on systems that
- * keep POSIX locks as a non-scalable data
- * structure in the kernel.
- */
- if (parent_longlived) {
- /* Ensure no clear-if-first. */
- active_lock = false;
- }
-
- if (tdb_reopen_internal(tdb, active_lock) != 0)
- return -1;
- }
-
- return 0;
-}
projects / ccan / blobdiff