/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
static struct tdb_context *tdbs = NULL;
-
-/* This is based on the hash algorithm from gdbm */
-static unsigned int default_tdb_hash(TDB_DATA *key)
-{
- uint32_t value; /* Used to compute the hash value. */
- uint32_t i; /* Used to cycle through random values. */
-
- /* Set the initial value from the key size. */
- for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
- value = (value + (key->dptr[i] << (i*5 % 24)));
-
- return (1103515243 * value + 12345);
-}
-
/* 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_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;
}
/* a default logging function */
-static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
+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,
unsigned char *vp;
uint32_t vertest;
unsigned v;
- uint32_t magic1_hash;
- uint32_t magic2_hash;
const char *hash_alg;
+ uint32_t magic1, magic2;
if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
/* Can't log this */
if (hash_fn) {
tdb->hash_fn = hash_fn;
- hash_alg = "user defined";
+ hash_alg = "the user defined";
} else {
- tdb->hash_fn = default_tdb_hash;
- hash_alg = "default";
+ /* 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 */
if (fstat(tdb->fd, &st) == -1)
goto fail;
- if (tdb->header.rwlocks != 0) {
+ 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;
}
- tdb_header_hash(tdb, &magic1_hash, &magic2_hash);
-
if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
/* older TDB without magic hash references */
- } else if ((tdb->header.magic1_hash != magic1_hash) ||
- (tdb->header.magic2_hash != magic2_hash)) {
+ 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 the %s hash function we are using\n"
+ "%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_hash) ? "==" : "!=",
- magic1_hash,
+ (tdb->header.magic1_hash == magic1) ? "==" : "!=",
+ magic1,
tdb->header.magic2_hash,
- (tdb->header.magic2_hash == magic2_hash) ? "==" : "!=",
- magic2_hash));
+ (tdb->header.magic2_hash == magic2) ? "==" : "!=",
+ magic2));
errno = EINVAL;
goto fail;
}