pytdb: Check if the database is closed before we touch it

If .close() has already been called, we have to play dead - the
self->ctx is just not valid any more, as we have been shut down to
allow some other part of Samba to open the tdb.

Andrew Bartlett

Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Mon Jul 16 13:51:52 CEST 2012 on sn-devel-104

lib/tdb/pytdb.c

@@ -75,6 +75,20 @@ static PyObject *PyString_FromTDB_DATA(TDB_DATA data)
 		return NULL; \
 	}
 
+#define PyErr_TDB_RAISE_IF_CLOSED(self) \
+	if (self->closed) {						\
+	        PyErr_SetObject(PyExc_RuntimeError,				\
+				Py_BuildValue("(i,s)", TDB_ERR_IO, "Database is already closed")); \
+		return NULL;						\
+	}
+
+#define PyErr_TDB_RAISE_RETURN_MINUS_1_IF_CLOSED(self) \
+	if (self->closed) {						\
+	        PyErr_SetObject(PyExc_RuntimeError,				\
+				Py_BuildValue("(i,s)", TDB_ERR_IO, "Database is already closed")); \
+		return -1;						\
+	}
+
 static PyObject *py_tdb_open(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 {
 	char *name = NULL;
@@ -109,56 +123,74 @@ static PyObject *py_tdb_open(PyTypeObject *type, PyObject *args, PyObject *kwarg
 
 static PyObject *obj_transaction_cancel(PyTdbObject *self)
 {
-	int ret = tdb_transaction_cancel(self->ctx);
+	int ret;
+
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
+	ret = tdb_transaction_cancel(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_transaction_commit(PyTdbObject *self)
 {
-	int ret = tdb_transaction_commit(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_transaction_commit(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_transaction_prepare_commit(PyTdbObject *self)
 {
-	int ret = tdb_transaction_prepare_commit(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_transaction_prepare_commit(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_transaction_start(PyTdbObject *self)
 {
-	int ret = tdb_transaction_start(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_transaction_start(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_reopen(PyTdbObject *self)
 {
-	int ret = tdb_reopen(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_reopen(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_lockall(PyTdbObject *self)
 {
-	int ret = tdb_lockall(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_lockall(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_unlockall(PyTdbObject *self)
 {
-	int ret = tdb_unlockall(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_unlockall(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_lockall_read(PyTdbObject *self)
 {
-	int ret = tdb_lockall_read(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_lockall_read(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
@@ -185,6 +217,9 @@ static PyObject *obj_get(PyTdbObject *self, PyObject *args)
 {
 	TDB_DATA key;
 	PyObject *py_key;
+
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	if (!PyArg_ParseTuple(args, "O", &py_key))
 		return NULL;
 
@@ -200,6 +235,9 @@ static PyObject *obj_append(PyTdbObject *self, PyObject *args)
 	TDB_DATA key, data;
 	PyObject *py_key, *py_data;
 	int ret;
+
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	if (!PyArg_ParseTuple(args, "OO", &py_key, &py_data))
 		return NULL;
 
@@ -217,6 +255,8 @@ static PyObject *obj_append(PyTdbObject *self, PyObject *args)
 
 static PyObject *obj_firstkey(PyTdbObject *self)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	return PyString_FromTDB_DATA(tdb_firstkey(self->ctx));
 }
 
@@ -224,6 +264,8 @@ static PyObject *obj_nextkey(PyTdbObject *self, PyObject *args)
 {
 	TDB_DATA key;
 	PyObject *py_key;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	if (!PyArg_ParseTuple(args, "O", &py_key))
 		return NULL;
 
@@ -239,6 +281,8 @@ static PyObject *obj_delete(PyTdbObject *self, PyObject *args)
 	TDB_DATA key;
 	PyObject *py_key;
 	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	if (!PyArg_ParseTuple(args, "O", &py_key))
 		return NULL;
 
@@ -255,6 +299,8 @@ static PyObject *obj_has_key(PyTdbObject *self, PyObject *args)
 	TDB_DATA key;
 	int ret;
 	PyObject *py_key;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	if (!PyArg_ParseTuple(args, "O", &py_key))
 		return NULL;
 
@@ -276,6 +322,8 @@ static PyObject *obj_store(PyTdbObject *self, PyObject *args)
 	int flag = TDB_REPLACE;
 	PyObject *py_key, *py_value;
 
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	if (!PyArg_ParseTuple(args, "OO|i", &py_key, &py_value, &flag))
 		return NULL;
 
@@ -295,6 +343,8 @@ static PyObject *obj_add_flags(PyTdbObject *self, PyObject *args)
 {
 	unsigned flags;
 
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	if (!PyArg_ParseTuple(args, "I", &flags))
 		return NULL;
 
@@ -306,6 +356,8 @@ static PyObject *obj_remove_flags(PyTdbObject *self, PyObject *args)
 {
 	unsigned flags;
 
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	if (!PyArg_ParseTuple(args, "I", &flags))
 		return NULL;
 
@@ -350,6 +402,8 @@ static PyObject *tdb_object_iter(PyTdbObject *self)
 {
 	PyTdbIteratorObject *ret;	
 
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+
 	ret = PyObject_New(PyTdbIteratorObject, &PyTdbIterator);
 	if (!ret)
 		return NULL;
@@ -361,26 +415,32 @@ static PyObject *tdb_object_iter(PyTdbObject *self)
 
 static PyObject *obj_clear(PyTdbObject *self)
 {
-	int ret = tdb_wipe_all(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_wipe_all(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_repack(PyTdbObject *self)
 {
-	int ret = tdb_repack(self->ctx);
+	int ret;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
+	ret = tdb_repack(self->ctx);
 	PyErr_TDB_ERROR_IS_ERR_RAISE(ret, self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_enable_seqnum(PyTdbObject *self)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	tdb_enable_seqnum(self->ctx);
 	Py_RETURN_NONE;
 }
 
 static PyObject *obj_increment_seqnum_nonblock(PyTdbObject *self)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	tdb_increment_seqnum_nonblock(self->ctx);
 	Py_RETURN_NONE;
 }
@@ -434,11 +494,13 @@ static PyMethodDef tdb_object_methods[] = {
 
 static PyObject *obj_get_hash_size(PyTdbObject *self, void *closure)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	return PyInt_FromLong(tdb_hash_size(self->ctx));
 }
 
 static int obj_set_max_dead(PyTdbObject *self, PyObject *max_dead, void *closure)
 {
+	PyErr_TDB_RAISE_RETURN_MINUS_1_IF_CLOSED(self);
 	if (!PyInt_Check(max_dead))
 		return -1;
 	tdb_set_max_dead(self->ctx, PyInt_AsLong(max_dead));
@@ -447,26 +509,31 @@ static int obj_set_max_dead(PyTdbObject *self, PyObject *max_dead, void *closure
 
 static PyObject *obj_get_map_size(PyTdbObject *self, void *closure)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	return PyInt_FromLong(tdb_map_size(self->ctx));
 }
 
 static PyObject *obj_get_freelist_size(PyTdbObject *self, void *closure)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	return PyInt_FromLong(tdb_freelist_size(self->ctx));
 }
 
 static PyObject *obj_get_flags(PyTdbObject *self, void *closure)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	return PyInt_FromLong(tdb_get_flags(self->ctx));
 }
 
 static PyObject *obj_get_filename(PyTdbObject *self, void *closure)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	return PyString_FromString(tdb_name(self->ctx));
 }
 
 static PyObject *obj_get_seqnum(PyTdbObject *self, void *closure)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	return PyInt_FromLong(tdb_get_seqnum(self->ctx));
 }
 
@@ -484,6 +551,7 @@ static PyGetSetDef tdb_object_getsetters[] = {
 
 static PyObject *tdb_object_repr(PyTdbObject *self)
 {
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	if (tdb_get_flags(self->ctx) & TDB_INTERNAL) {
 		return PyString_FromString("Tdb(<internal>)");
 	} else {
@@ -501,6 +569,7 @@ static void tdb_object_dealloc(PyTdbObject *self)
 static PyObject *obj_getitem(PyTdbObject *self, PyObject *key)
 {
 	TDB_DATA tkey, val;
+	PyErr_TDB_RAISE_IF_CLOSED(self);
 	if (!PyString_Check(key)) {
 		PyErr_SetString(PyExc_TypeError, "Expected string as key");
 		return NULL;
@@ -522,6 +591,7 @@ static int obj_setitem(PyTdbObject *self, PyObject *key, PyObject *value)
 {
 	TDB_DATA tkey, tval;
 	int ret;
+	PyErr_TDB_RAISE_RETURN_MINUS_1_IF_CLOSED(self);
 	if (!PyString_Check(key)) {
 		PyErr_SetString(PyExc_TypeError, "Expected string as key");
 		return -1;

lib/tdb/python/tests/simple.py

@@ -33,6 +33,11 @@ class CloseTdbTests(TestCase):
         self.tdb.close()
         self.tdb.close()
 
+        # Check that further operations do not crash python
+        self.assertRaises(RuntimeError, lambda: self.tdb.transaction_start())
+
+        self.assertRaises(RuntimeError, lambda: self.tdb["bar"])
+
 
 class InternalTdbTests(TestCase):