python: samba.param: Port param module to Python 3

Port Python bindings of samba.param module to
Python3-compatible form.

Because native Python file objects are officially
no longer backed by FILE*, API of some _dump()
functions is changed. File argument is now
optional and contains only name of file. Stdout
is default if no file name is specified. Otherwise
opening and closing files is done on C layer
instead of Python.

Signed-off-by: Lumir Balhar <lbalhar@redhat.com>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>

2 files changed, 84 insertions, 42 deletions

diff --git a/source4/param/pyparam.c b/source4/param/pyparam.c
index 60c46452447..713e608cf1b 100644
--- a/source4/param/pyparam.c
+++ b/source4/param/pyparam.c
@@ -18,14 +18,13 @@
 */
 
 #include <Python.h>
+#include "python/py3compat.h"
 #include "includes.h"
 #include "param/param.h"
 #include "param/loadparm.h"
 #include <pytalloc.h>
 #include "dynconfig/dynconfig.h"
 
-void initparam(void);
-
 #define PyLoadparmContext_AsLoadparmContext(obj) pytalloc_get_type(obj, struct loadparm_context)
 #define PyLoadparmService_AsLoadparmService(obj) pytalloc_get_type(obj, struct loadparm_service)
 
@@ -64,7 +63,7 @@ static PyObject *py_lp_ctx_get_helper(struct loadparm_context *lp_ctx, const cha
 			if (value == NULL) {
 			return NULL;
 			}
-			return PyString_FromString(value);
+			return PyStr_FromString(value);
 		}
 
 		parm = lpcfg_parm_struct(lp_ctx, param_name);
@@ -84,7 +83,7 @@ static PyObject *py_lp_ctx_get_helper(struct loadparm_context *lp_ctx, const cha
 		value = lpcfg_get_parametric(lp_ctx, NULL, type, option);
 		if (value == NULL)
 			return NULL;
-		return PyString_FromString(value);
+		return PyStr_FromString(value);
 	} else {
 		/* its a global parameter */
 		parm = lpcfg_parm_struct(lp_ctx, param_name);
@@ -101,10 +100,10 @@ static PyObject *py_lp_ctx_get_helper(struct loadparm_context *lp_ctx, const cha
     /* construct and return the right type of python object */
     switch (parm->type) {
     case P_CHAR:
-	return PyString_FromFormat("%c", *(char *)parm_ptr);
+	return PyStr_FromFormat("%c", *(char *)parm_ptr);
     case P_STRING:
     case P_USTRING:
-	return PyString_FromString(*(char **)parm_ptr);
+	return PyStr_FromString(*(char **)parm_ptr);
     case P_BOOL:
 	return PyBool_FromLong(*(bool *)parm_ptr);
     case P_BOOLREV:
@@ -116,7 +115,7 @@ static PyObject *py_lp_ctx_get_helper(struct loadparm_context *lp_ctx, const cha
     case P_ENUM:
 	for (i=0; parm->enum_list[i].name; i++) {
 	    if (*(int *)parm_ptr == parm->enum_list[i].value) {
-		return PyString_FromString(parm->enum_list[i].name);
+		return PyStr_FromString(parm->enum_list[i].name);
 	    }
 	}
 	return NULL;
@@ -134,7 +133,7 @@ static PyObject *py_lp_ctx_get_helper(struct loadparm_context *lp_ctx, const cha
 	    pylist = PyList_New(str_list_length(strlist));
 	    for (j = 0; strlist[j]; j++) 
 		PyList_SetItem(pylist, j, 
-			       PyString_FromString(strlist[j]));
+			       PyStr_FromString(strlist[j]));
 	    return pylist;
 	}
     }
@@ -226,7 +225,7 @@ static PyObject *py_lp_ctx_private_path(PyObject *self, PyObject *args)
 		return NULL;
 
 	path = lpcfg_private_path(NULL, PyLoadparmContext_AsLoadparmContext(self), name);
-	ret = PyString_FromString(path);
+	ret = PyStr_FromString(path);
 	talloc_free(path);
 
 	return ret;
@@ -241,7 +240,7 @@ static PyObject *py_lp_ctx_services(PyObject *self, PyObject *unused)
 	for (i = 0; i < lpcfg_numservices(lp_ctx); i++) {
 		struct loadparm_service *service = lpcfg_servicebynum(lp_ctx, i);
 		if (service != NULL) {
-			PyList_SetItem(ret, i, PyString_FromString(lpcfg_servicename(service)));
+			PyList_SetItem(ret, i, PyStr_FromString(lpcfg_servicename(service)));
 		}
 	}
 	return ret;
@@ -256,43 +255,60 @@ static PyObject *py_lp_ctx_server_role(PyObject *self, PyObject *unused)
 	role = lpcfg_server_role(lp_ctx);
 	role_str = server_role_str(role);
 
-	return PyString_FromString(role_str);
+	return PyStr_FromString(role_str);
 }
 
 static PyObject *py_lp_dump(PyObject *self, PyObject *args)
 {
-	PyObject *py_stream;
 	bool show_defaults = false;
+	const char *file_name = "";
+	const char *mode = "w";
 	FILE *f;
 	struct loadparm_context *lp_ctx = PyLoadparmContext_AsLoadparmContext(self);
 
-	if (!PyArg_ParseTuple(args, "O|b", &py_stream, &show_defaults))
+	if (!PyArg_ParseTuple(args, "|bss", &show_defaults, &file_name, &mode))
 		return NULL;
 
-	f = PyFile_AsFile(py_stream);
+	if (file_name[0] == '\0') {
+		f = stdout;
+	} else {
+		f = fopen(file_name, mode);
+	}
+
 	if (f == NULL) {
+		PyErr_SetFromErrno(PyExc_IOError);
 		return NULL;
 	}
 
 	lpcfg_dump(lp_ctx, f, show_defaults, lpcfg_numservices(lp_ctx));
 
+	if (f != stdout) {
+		fclose(f);
+	}
+
 	Py_RETURN_NONE;
 }
 
 static PyObject *py_lp_dump_a_parameter(PyObject *self, PyObject *args)
 {
-	PyObject *py_stream;
 	char *param_name;
 	const char *section_name = NULL;
+	const char *file_name = "";
+	const char *mode = "w";
 	FILE *f;
 	struct loadparm_context *lp_ctx = PyLoadparmContext_AsLoadparmContext(self);
 	struct loadparm_service *service;
 	bool ret;
 
-	if (!PyArg_ParseTuple(args, "Os|z", &py_stream, &param_name, &section_name))
+	if (!PyArg_ParseTuple(args, "s|zss", &param_name, &section_name, &file_name, &mode))
 		return NULL;
 
-	f = PyFile_AsFile(py_stream);
+	if (file_name[0] == '\0') {
+		f = stdout;
+	} else {
+		f = fopen(file_name, mode);
+	}
+
 	if (f == NULL) {
 		return NULL;
 	}
@@ -318,6 +334,10 @@ static PyObject *py_lp_dump_a_parameter(PyObject *self, PyObject *args)
 		return NULL;
 	}
 
+	if (f != stdout) {
+		fclose(f);
+	}
+
 	Py_RETURN_NONE;
 
 }
@@ -332,7 +352,7 @@ static PyObject *py_lp_log_level(PyObject *self, PyObject *unused)
 static PyObject *py_samdb_url(PyObject *self, PyObject *unused)
 {
 	struct loadparm_context *lp_ctx = PyLoadparmContext_AsLoadparmContext(self);
-	return PyString_FromFormat("tdb://%s/sam.ldb", lpcfg_private_dir(lp_ctx));
+	return PyStr_FromFormat("tdb://%s/sam.ldb", lpcfg_private_dir(lp_ctx));
 }
 
 
@@ -363,11 +383,11 @@ static PyMethodDef py_lp_ctx_methods[] = {
 		"S.server_role() -> value\n"
 		"Get the server role." },
 	{ "dump", py_lp_dump, METH_VARARGS,
-		"S.dump(stream, show_defaults=False)" },
+		"S.dump(show_defaults=False, file_name='', mode='w')" },
+	{ "dump_a_parameter", py_lp_dump_a_parameter, METH_VARARGS,
+		"S.dump_a_parameter(name, service_name, file_name='', mode='w')" },
 	{ "log_level", py_lp_log_level, METH_NOARGS,
 		"S.log_level() -> int\n Get the active log level" },
-	{ "dump_a_parameter", py_lp_dump_a_parameter, METH_VARARGS,
-		"S.dump_a_parameter(stream, name, service_name)" },
 	{ "samdb_url", py_samdb_url, METH_NOARGS,
 	        "S.samdb_url() -> string\n"
 	        "Returns the current URL for sam.ldb." },
@@ -385,7 +405,7 @@ static PyObject *py_lp_ctx_config_file(PyObject *self, void *closure)
 	if (configfile == NULL)
 		Py_RETURN_NONE;
 	else
-		return PyString_FromString(configfile);
+		return PyStr_FromString(configfile);
 }
 
 static PyGetSetDef py_lp_ctx_getset[] = {
@@ -408,11 +428,11 @@ static Py_ssize_t py_lp_ctx_len(PyObject *self)
 static PyObject *py_lp_ctx_getitem(PyObject *self, PyObject *name)
 {
 	struct loadparm_service *service;
-	if (!PyString_Check(name)) {
+	if (!PyStr_Check(name)) {
 		PyErr_SetString(PyExc_TypeError, "Only string subscripts are supported");
 		return NULL;
 	}
-	service = lpcfg_service(PyLoadparmContext_AsLoadparmContext(self), PyString_AsString(name));
+	service = lpcfg_service(PyLoadparmContext_AsLoadparmContext(self), PyStr_AsString(name));
 	if (service == NULL) {
 		PyErr_SetString(PyExc_KeyError, "No such section");
 		return NULL;
@@ -436,18 +456,23 @@ PyTypeObject PyLoadparmContext = {
 
 static PyObject *py_lp_service_dump(PyObject *self, PyObject *args)
 {
-	PyObject *py_stream;
 	bool show_defaults = false;
 	FILE *f;
+	const char *file_name = "";
+	const char *mode = "w";
 	struct loadparm_service *service = PyLoadparmService_AsLoadparmService(self);
 	struct loadparm_service *default_service;
 	PyObject *py_default_service;
 
-	if (!PyArg_ParseTuple(args, "OO|b", &py_stream, &py_default_service,
-						  &show_defaults))
+	if (!PyArg_ParseTuple(args, "O|bss", &py_default_service, &show_defaults, &file_name, &mode))
 		return NULL;
 
-	f = PyFile_AsFile(py_stream);
+	if (file_name[0] == '\0') {
+		f = stdout;
+	} else {
+		f = fopen(file_name, mode);
+	}
+
 	if (f == NULL) {
 		return NULL;
 	}
@@ -461,12 +486,16 @@ static PyObject *py_lp_service_dump(PyObject *self, PyObject *args)
 
 	lpcfg_dump_one(f, show_defaults, service, default_service);
 
+	if (f != stdout) {
+		fclose(f);
+	}
+
 	Py_RETURN_NONE;
 }
 
 static PyMethodDef py_lp_service_methods[] = {
 	{ "dump", (PyCFunction)py_lp_service_dump, METH_VARARGS, 
-		"S.dump(f, default_service, show_defaults=False)" },
+		"S.dump(default_service, show_defaults=False, file_name='', mode='w')" },
 	{ NULL }
 };
 
@@ -478,27 +507,27 @@ PyTypeObject PyLoadparmService = {
 
 static PyObject *py_default_path(PyObject *self)
 {
-	return PyString_FromString(lp_default_path());
+	return PyStr_FromString(lp_default_path());
 }
 
 static PyObject *py_setup_dir(PyObject *self)
 {
-	return PyString_FromString(dyn_SETUPDIR);
+	return PyStr_FromString(dyn_SETUPDIR);
 }
 
 static PyObject *py_modules_dir(PyObject *self)
 {
-	return PyString_FromString(dyn_MODULESDIR);
+	return PyStr_FromString(dyn_MODULESDIR);
 }
 
 static PyObject *py_bin_dir(PyObject *self)
 {
-	return PyString_FromString(dyn_BINDIR);
+	return PyStr_FromString(dyn_BINDIR);
 }
 
 static PyObject *py_sbin_dir(PyObject *self)
 {
-	return PyString_FromString(dyn_SBINDIR);
+	return PyStr_FromString(dyn_SBINDIR);
 }
 
 static PyMethodDef pyparam_methods[] = {
@@ -515,20 +544,32 @@ static PyMethodDef pyparam_methods[] = {
 	{ NULL }
 };
 
-void initparam(void)
+static struct PyModuleDef moduledef = {
+	PyModuleDef_HEAD_INIT,
+	.m_name = "param",
+	.m_doc = "Parsing and writing Samba configuration files.",
+	.m_size = -1,
+	.m_methods = pyparam_methods,
+};
+
+MODULE_INIT_FUNC(param)
 {
 	PyObject *m;
+	PyTypeObject *talloc_type = pytalloc_GetObjectType();
+	if (talloc_type == NULL)
+		return NULL;
 
 	if (pytalloc_BaseObject_PyType_Ready(&PyLoadparmContext) < 0)
-		return;
+		return NULL;
 
 	if (pytalloc_BaseObject_PyType_Ready(&PyLoadparmService) < 0)
-		return;
+		return NULL;
 
-	m = Py_InitModule3("param", pyparam_methods, "Parsing and writing Samba configuration files.");
+	m = PyModule_Create(&moduledef);
 	if (m == NULL)
-		return;
+		return NULL;
 
 	Py_INCREF(&PyLoadparmContext);
 	PyModule_AddObject(m, "LoadParm", (PyObject *)&PyLoadparmContext);
+	return m;
 }
diff --git a/source4/param/pyparam_util.c b/source4/param/pyparam_util.c
index 874d78363b7..512a8b1cdb7 100644
--- a/source4/param/pyparam_util.c
+++ b/source4/param/pyparam_util.c
@@ -18,6 +18,7 @@
 */
 
 #include <Python.h>
+#include "py3compat.h"
 #include "includes.h"
 #include "param/param.h"
 #include "param/pyparam.h"
@@ -33,14 +34,14 @@ _PUBLIC_ struct loadparm_context *lpcfg_from_py_object(TALLOC_CTX *mem_ctx, PyOb
 	PyTypeObject *lp_type;
 	bool is_lpobj;
 
-	if (PyString_Check(py_obj)) {
+	if (PyStr_Check(py_obj)) {
 		lp_ctx = loadparm_init_global(false);
 		if (lp_ctx == NULL) {
 			return NULL;
 		}
-		if (!lpcfg_load(lp_ctx, PyString_AsString(py_obj))) {
+		if (!lpcfg_load(lp_ctx, PyStr_AsString(py_obj))) {
 			PyErr_Format(PyExc_RuntimeError, "Unable to load %s", 
-				     PyString_AsString(py_obj));
+				     PyStr_AsString(py_obj));
 			return NULL;
 		}
 		return lp_ctx;