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samba-mirror/lib/dbwrap/dbwrap.c
Michael Adam c7961ee495 dbwrap: completely check validity of lock order in dbwrap_check_lock_order()
This is currently not strictly necessay, because the
only caller catches the DBWRAP_LOCK_ORDER_NONE case,
and maximum is already checked,  but this seems too dangerous to me.

Use the new DBWRAP_LOCK_ORDER_VALID() macro.

Signed-off-by: Michael Adam <obnox@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2014-02-07 16:06:07 +01:00

471 lines
11 KiB
C

/*
Unix SMB/CIFS implementation.
Database interface wrapper
Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2006
Major code contributions from Aleksey Fedoseev (fedoseev@ru.ibm.com)
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_private.h"
#include "lib/util/util_tdb.h"
/*
* Fall back using fetch if no genuine exists operation is provided
*/
static int dbwrap_fallback_exists(struct db_context *db, TDB_DATA key)
{
NTSTATUS status = dbwrap_parse_record(db, key, NULL, NULL);
return NT_STATUS_IS_OK(status) ? 1 : 0;
}
static int delete_record(struct db_record *rec, void *data)
{
NTSTATUS status = dbwrap_record_delete(rec);
return NT_STATUS_IS_OK(status) ? 0 : -1;
}
/*
* Fallback wipe implementation using traverse and delete if no genuine
* wipe operation is provided
*/
static int dbwrap_fallback_wipe(struct db_context *db)
{
NTSTATUS status = dbwrap_trans_traverse(db, delete_record, NULL);
return NT_STATUS_IS_OK(status) ? 0 : -1;
}
static int do_nothing(struct db_record *rec, void *unused)
{
return 0;
}
/*
* Fallback check operation: just traverse.
*/
static int dbwrap_fallback_check(struct db_context *db)
{
NTSTATUS status = dbwrap_traverse_read(db, do_nothing, NULL, NULL);
return NT_STATUS_IS_OK(status) ? 0 : -1;
}
/*
* Wrapper functions for the backend methods
*/
TDB_DATA dbwrap_record_get_key(const struct db_record *rec)
{
return rec->key;
}
TDB_DATA dbwrap_record_get_value(const struct db_record *rec)
{
return rec->value;
}
NTSTATUS dbwrap_record_store(struct db_record *rec, TDB_DATA data, int flags)
{
NTSTATUS status;
struct db_context *db;
status = rec->store(rec, data, flags);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
db = rec->db;
if (db->stored_callback != NULL) {
db->stored_callback(db, rec,
db->stored_callback_private_data);
}
return NT_STATUS_OK;
}
void dbwrap_set_stored_callback(
struct db_context *db,
void (*cb)(struct db_context *db, struct db_record *rec,
void *private_data),
void *private_data)
{
db->stored_callback = cb;
db->stored_callback_private_data = private_data;
}
NTSTATUS dbwrap_record_delete(struct db_record *rec)
{
NTSTATUS status;
struct db_context *db;
status = rec->delete_rec(rec);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
db = rec->db;
if (db->stored_callback != NULL) {
db->stored_callback(db, rec,
db->stored_callback_private_data);
}
return NT_STATUS_OK;
}
struct dbwrap_lock_order_state {
struct db_context **locked_dbs;
struct db_context *db;
};
static void debug_lock_order(int level, struct db_context *dbs[])
{
int i;
DEBUG(level, ("lock order: "));
for (i=0; i<DBWRAP_LOCK_ORDER_MAX; i++) {
DEBUGADD(level, (" %d:%s", i + 1, dbs[i] ? dbs[i]->name : "<none>"));
}
DEBUGADD(level, ("\n"));
}
static int dbwrap_lock_order_state_destructor(
struct dbwrap_lock_order_state *s)
{
int idx = s->db->lock_order - 1;
DEBUG(5, ("release lock order %d for %s\n",
(int)s->db->lock_order, s->db->name));
if (s->locked_dbs[idx] != s->db) {
DEBUG(0, ("locked db at lock order %d is %s, expected %s\n",
idx + 1, s->locked_dbs[idx]->name, s->db->name));
debug_lock_order(0, s->locked_dbs);
smb_panic("inconsistent lock_order\n");
}
s->locked_dbs[idx] = NULL;
debug_lock_order(10, s->locked_dbs);
return 0;
}
static struct dbwrap_lock_order_state *dbwrap_check_lock_order(
struct db_context *db, TALLOC_CTX *mem_ctx)
{
int idx;
static struct db_context *locked_dbs[DBWRAP_LOCK_ORDER_MAX];
struct dbwrap_lock_order_state *state = NULL;
if (!DBWRAP_LOCK_ORDER_VALID(db->lock_order)) {
DEBUG(0,("Invalid lock order %d of %s\n",
(int)db->lock_order, db->name));
smb_panic("invalid lock_order\n");
return NULL;
}
DEBUG(5, ("check lock order %d for %s\n",
(int)db->lock_order, db->name));
for (idx=db->lock_order - 1; idx < DBWRAP_LOCK_ORDER_MAX; idx++) {
if (locked_dbs[idx] != NULL) {
DEBUG(0, ("Lock order violation: Trying %s at %d while %s at %d is locked\n",
db->name, (int)db->lock_order, locked_dbs[idx]->name, idx + 1));
debug_lock_order(0, locked_dbs);
smb_panic("invalid lock_order");
return NULL;
}
}
state = talloc(mem_ctx, struct dbwrap_lock_order_state);
if (state == NULL) {
DEBUG(1, ("talloc failed\n"));
return NULL;
}
state->db = db;
state->locked_dbs = locked_dbs;
talloc_set_destructor(state, dbwrap_lock_order_state_destructor);
locked_dbs[db->lock_order - 1] = db;
debug_lock_order(10, locked_dbs);
return state;
}
static struct db_record *dbwrap_fetch_locked_internal(
struct db_context *db, TALLOC_CTX *mem_ctx, TDB_DATA key,
struct db_record *(*db_fn)(struct db_context *db, TALLOC_CTX *mem_ctx,
TDB_DATA key))
{
struct db_record *rec;
struct dbwrap_lock_order_state *lock_order = NULL;
if (db->lock_order != DBWRAP_LOCK_ORDER_NONE) {
lock_order = dbwrap_check_lock_order(db, mem_ctx);
if (lock_order == NULL) {
return NULL;
}
}
rec = db_fn(db, mem_ctx, key);
if (rec == NULL) {
TALLOC_FREE(lock_order);
return NULL;
}
(void)talloc_steal(rec, lock_order);
rec->db = db;
return rec;
}
struct db_record *dbwrap_fetch_locked(struct db_context *db,
TALLOC_CTX *mem_ctx,
TDB_DATA key)
{
return dbwrap_fetch_locked_internal(db, mem_ctx, key,
db->fetch_locked);
}
struct db_record *dbwrap_try_fetch_locked(struct db_context *db,
TALLOC_CTX *mem_ctx,
TDB_DATA key)
{
return dbwrap_fetch_locked_internal(
db, mem_ctx, key,
db->try_fetch_locked
? db->try_fetch_locked : db->fetch_locked);
}
struct db_context *dbwrap_record_get_db(struct db_record *rec)
{
return rec->db;
}
struct dbwrap_fetch_state {
TALLOC_CTX *mem_ctx;
TDB_DATA data;
};
static void dbwrap_fetch_parser(TDB_DATA key, TDB_DATA data,
void *private_data)
{
struct dbwrap_fetch_state *state =
(struct dbwrap_fetch_state *)private_data;
state->data.dsize = data.dsize;
state->data.dptr = (uint8_t *)talloc_memdup(state->mem_ctx, data.dptr,
data.dsize);
}
NTSTATUS dbwrap_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
TDB_DATA key, TDB_DATA *value)
{
struct dbwrap_fetch_state state;
NTSTATUS status;
if (value == NULL) {
return NT_STATUS_INVALID_PARAMETER;
}
state.mem_ctx = mem_ctx;
status = dbwrap_parse_record(db, key, dbwrap_fetch_parser, &state);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
if ((state.data.dsize != 0) && (state.data.dptr == NULL)) {
return NT_STATUS_NO_MEMORY;
}
*value = state.data;
return NT_STATUS_OK;
}
bool dbwrap_exists(struct db_context *db, TDB_DATA key)
{
int result;
if (db->exists != NULL) {
result = db->exists(db, key);
} else {
result = dbwrap_fallback_exists(db,key);
}
return (result == 1);
}
NTSTATUS dbwrap_store(struct db_context *db, TDB_DATA key,
TDB_DATA data, int flags)
{
struct db_record *rec;
NTSTATUS status;
TALLOC_CTX *frame = talloc_stackframe();
rec = dbwrap_fetch_locked(db, frame, key);
if (rec == NULL) {
TALLOC_FREE(frame);
return NT_STATUS_NO_MEMORY;
}
status = dbwrap_record_store(rec, data, flags);
TALLOC_FREE(frame);
return status;
}
NTSTATUS dbwrap_delete(struct db_context *db, TDB_DATA key)
{
struct db_record *rec;
NTSTATUS status;
TALLOC_CTX *frame = talloc_stackframe();
rec = dbwrap_fetch_locked(db, frame, key);
if (rec == NULL) {
TALLOC_FREE(frame);
return NT_STATUS_NO_MEMORY;
}
status = dbwrap_record_delete(rec);
TALLOC_FREE(frame);
return status;
}
NTSTATUS dbwrap_traverse(struct db_context *db,
int (*f)(struct db_record*, void*),
void *private_data,
int *count)
{
int ret = db->traverse(db, f, private_data);
if (ret < 0) {
return NT_STATUS_INTERNAL_DB_CORRUPTION;
}
if (count != NULL) {
*count = ret;
}
return NT_STATUS_OK;
}
NTSTATUS dbwrap_traverse_read(struct db_context *db,
int (*f)(struct db_record*, void*),
void *private_data,
int *count)
{
int ret = db->traverse_read(db, f, private_data);
if (ret < 0) {
return NT_STATUS_INTERNAL_DB_CORRUPTION;
}
if (count != NULL) {
*count = ret;
}
return NT_STATUS_OK;
}
static void dbwrap_null_parser(TDB_DATA key, TDB_DATA val, void* data)
{
return;
}
NTSTATUS dbwrap_parse_record(struct db_context *db, TDB_DATA key,
void (*parser)(TDB_DATA key, TDB_DATA data,
void *private_data),
void *private_data)
{
if (parser == NULL) {
parser = dbwrap_null_parser;
}
return db->parse_record(db, key, parser, private_data);
}
int dbwrap_wipe(struct db_context *db)
{
if (db->wipe == NULL) {
return dbwrap_fallback_wipe(db);
}
return db->wipe(db);
}
int dbwrap_hash_size(struct db_context *db)
{
return db->hash_size;
}
int dbwrap_check(struct db_context *db)
{
if (db->check == NULL) {
return dbwrap_fallback_check(db);
}
return db->check(db);
}
int dbwrap_get_seqnum(struct db_context *db)
{
return db->get_seqnum(db);
}
int dbwrap_transaction_start(struct db_context *db)
{
if (!db->persistent) {
/*
* dbwrap_ctdb has two different data models for persistent
* and non-persistent databases. Transactions are supported
* only for the persistent databases. This check is here to
* prevent breakages of the cluster case, autobuild at this
* point only tests non-clustered Samba. Before removing this
* check, please make sure that this facility has also been
* added to dbwrap_ctdb.
*
* Thanks, vl
*/
DEBUG(1, ("transactions not supported on non-persistent "
"database %s\n", db->name));
return -1;
}
return db->transaction_start(db);
}
NTSTATUS dbwrap_transaction_start_nonblock(struct db_context *db)
{
if (db->transaction_start_nonblock) {
return db->transaction_start_nonblock(db);
} else {
return dbwrap_transaction_start(db) == 0 ? NT_STATUS_OK
: NT_STATUS_UNSUCCESSFUL;
}
}
int dbwrap_transaction_commit(struct db_context *db)
{
return db->transaction_commit(db);
}
int dbwrap_transaction_cancel(struct db_context *db)
{
return db->transaction_cancel(db);
}
void dbwrap_db_id(struct db_context *db, const uint8_t **id, size_t *idlen)
{
db->id(db, id, idlen);
}
bool dbwrap_is_persistent(struct db_context *db)
{
return db->persistent;
}
const char *dbwrap_name(struct db_context *db)
{
return db->name;
}