Files
sudo/plugins/python/python_plugin_common.c
Robert Manner 21c02e1732 plugins/python/sudo_python_module.c: use IntEnums instead of constants
It is a bit more code, but it is more "pythonic" and easier to debug
as the enum values also know their names.

It is also an API break, eg. sudo.RC_OK becomes sudo.RC.OK as sudo.RC will
be the "type" of the enum, but I guess that is acceptable before the
initial release.
2020-02-10 05:24:16 -07:00

479 lines
16 KiB
C

/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 2019 Robert Manner <robert.manner@oneidentity.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include "python_plugin_common.h"
#include "sudo_python_module.h"
#include "sudo_queue.h"
#include "sudo_conf.h"
#include <limits.h>
#include <string.h>
const char *
_lookup_value(char * const keyvalues[], const char *key)
{
debug_decl(_lookup_value, PYTHON_DEBUG_INTERNAL);
if (keyvalues == NULL)
debug_return_const_str(NULL);
size_t keylen = strlen(key);
for (; *keyvalues != NULL; ++keyvalues) {
const char *keyvalue = *keyvalues;
if (strncmp(keyvalue, key, keylen) == 0 && keyvalue[keylen] == '=')
debug_return_const_str(keyvalue + keylen + 1);
}
debug_return_const_str(NULL);
}
CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION
int
_append_python_path(const char *module_dir)
{
debug_decl(_py_debug_python_function, PYTHON_DEBUG_PLUGIN_LOAD);
int rc = -1;
PyObject *py_sys_path = PySys_GetObject("path");
if (py_sys_path == NULL) {
PyErr_Format(sudo_exc_SudoException, "Failed to get python 'path'");
debug_return_int(rc);
}
sudo_debug_printf(SUDO_DEBUG_DIAG, "Extending python 'path' with '%s'\n", module_dir);
PyObject *py_module_dir = PyUnicode_FromString(module_dir);
if (py_module_dir == NULL || PyList_Append(py_sys_path, py_module_dir) != 0) {
Py_XDECREF(py_module_dir);
debug_return_int(rc);
}
Py_XDECREF(py_module_dir);
if (sudo_debug_needed(SUDO_DEBUG_INFO)) {
char *path = py_join_str_list(py_sys_path, ":");
sudo_debug_printf(SUDO_DEBUG_INFO, "Python path became: %s\n", path);
free(path);
}
rc = 0;
debug_return_int(rc);
}
static PyObject *
_import_module(const char *path)
{
debug_decl(_import_module, PYTHON_DEBUG_PLUGIN_LOAD);
sudo_debug_printf(SUDO_DEBUG_DIAG, "importing module: %s\n", path);
char path_copy[PATH_MAX];
if (strlcpy(path_copy, path, sizeof(path_copy)) >= sizeof(path_copy))
debug_return_ptr(NULL);
char *module_dir = path_copy;
char *module_name = strrchr(path_copy, '/');
if (module_name == NULL) {
module_name = path_copy;
module_dir = "";
} else {
*module_name++ = '\0';
}
size_t len = strlen(module_name);
if (len >= 3 && strcmp(".py", module_name + len - 3) == 0)
module_name[len - 3] = '\0';
sudo_debug_printf(SUDO_DEBUG_INFO, "module_name: '%s', module_dir: '%s'\n", module_name, module_dir);
if (_append_python_path(module_dir) < 0)
debug_return_ptr(NULL);
debug_return_ptr(PyImport_ImportModule(module_name));
}
int
python_plugin_construct_custom(struct PluginContext *plugin_ctx, PyObject *py_kwargs)
{
debug_decl(python_plugin_construct_custom, PYTHON_DEBUG_PLUGIN_LOAD);
int rc = SUDO_RC_ERROR;
PyObject *py_args = PyTuple_New(0);
if (py_args == NULL)
goto cleanup;
py_debug_python_call(python_plugin_name(plugin_ctx), "__init__",
py_args, py_kwargs, PYTHON_DEBUG_PY_CALLS);
plugin_ctx->py_instance = PyObject_Call(plugin_ctx->py_class, py_args, py_kwargs);
py_debug_python_result(python_plugin_name(plugin_ctx), "__init__",
plugin_ctx->py_instance, PYTHON_DEBUG_PY_CALLS);
rc = SUDO_RC_OK;
cleanup:
if (plugin_ctx->py_instance == NULL) {
py_log_last_error("Failed to construct plugin instance");
rc = SUDO_RC_ERROR;
}
Py_XDECREF(py_args);
debug_return_int(rc);
}
int
python_plugin_construct(struct PluginContext *plugin_ctx, unsigned int version,
char *const settings[], char *const user_info[],
char *const user_env[], char *const plugin_options[])
{
debug_decl(python_plugin_construct, PYTHON_DEBUG_PLUGIN_LOAD);
int rc = SUDO_RC_ERROR;
PyObject *py_settings = NULL;
PyObject *py_user_info = NULL;
PyObject *py_user_env = NULL;
PyObject *py_plugin_options = NULL;
PyObject *py_version = NULL;
PyObject *py_kwargs = NULL;
if ((py_settings = py_str_array_to_tuple(settings)) == NULL ||
(py_user_info = py_str_array_to_tuple(user_info)) == NULL ||
(py_user_env = py_str_array_to_tuple(user_env)) == NULL ||
(py_plugin_options = py_str_array_to_tuple(plugin_options)) == NULL ||
(py_version = py_create_version(version)) == NULL ||
(py_kwargs = PyDict_New()) == NULL ||
PyDict_SetItemString(py_kwargs, "version", py_version) != 0 ||
PyDict_SetItemString(py_kwargs, "settings", py_settings) != 0 ||
PyDict_SetItemString(py_kwargs, "user_env", py_user_env) != 0 ||
PyDict_SetItemString(py_kwargs, "user_info", py_user_info) != 0 ||
PyDict_SetItemString(py_kwargs, "plugin_options", py_plugin_options) != 0)
{
py_log_last_error("Failed to construct plugin instance");
rc = SUDO_RC_ERROR;
} else {
rc = python_plugin_construct_custom(plugin_ctx, py_kwargs);
}
Py_XDECREF(py_settings);
Py_XDECREF(py_user_info);
Py_XDECREF(py_user_env);
Py_XDECREF(py_plugin_options);
Py_XDECREF(py_version);
Py_XDECREF(py_kwargs);
debug_return_int(rc);
}
int
python_plugin_register_logging(sudo_conv_t conversation,
sudo_printf_t sudo_printf,
char * const settings[])
{
debug_decl(python_plugin_register_logging, PYTHON_DEBUG_INTERNAL);
int rc = SUDO_RC_ERROR;
if (py_ctx.sudo_conv == NULL)
py_ctx.sudo_conv = conversation;
if (sudo_printf)
py_ctx.sudo_log = sudo_printf;
struct sudo_conf_debug_file_list debug_files = TAILQ_HEAD_INITIALIZER(debug_files);
struct sudo_conf_debug_file_list *debug_files_ptr = &debug_files;
const char *plugin_path = _lookup_value(settings, "plugin_path");
if (plugin_path == NULL)
plugin_path = "python_plugin.so";
const char *debug_flags = _lookup_value(settings, "debug_flags");
if (debug_flags == NULL) { // the group plugin does not have this information, so try to look it up
debug_files_ptr = sudo_conf_debug_files(plugin_path);
} else {
if (!python_debug_parse_flags(&debug_files, debug_flags))
goto cleanup;
}
if (debug_files_ptr != NULL) {
if (!python_debug_register(plugin_path, debug_files_ptr))
goto cleanup;
}
rc = SUDO_RC_OK;
cleanup:
debug_return_int(rc);
}
CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION
static int
_python_plugin_register_plugin_in_py_ctx(void)
{
debug_decl(_python_plugin_register_plugin_in_py_ctx, PYTHON_DEBUG_PLUGIN_LOAD);
if (!Py_IsInitialized()) {
py_ctx.open_plugin_count = 0;
// Disable environment variables effecting the python interpreter
// This is important since we are running code here as root, the
// user should not be able to alter what is running any how.
Py_IgnoreEnvironmentFlag = 1;
Py_IsolatedFlag = 1;
Py_NoUserSiteDirectory = 1;
PyImport_AppendInittab("sudo", sudo_module_init);
Py_InitializeEx(0);
py_ctx.py_main_interpreter = PyThreadState_Get();
// This ensures we import "sudo" module in the main interpreter,
// each subinterpreter will have a shallow copy.
// (This makes the C sudo module able to eg. import other modules.)
PyObject *py_sudo = NULL;
if ((py_sudo = PyImport_ImportModule("sudo")) == NULL) {
debug_return_int(SUDO_RC_ERROR);
}
Py_CLEAR(py_sudo);
} else {
PyThreadState_Swap(py_ctx.py_main_interpreter);
}
++py_ctx.open_plugin_count;
debug_return_int(SUDO_RC_OK);
}
int
python_plugin_init(struct PluginContext *plugin_ctx, char * const plugin_options[])
{
debug_decl(python_plugin_init, PYTHON_DEBUG_PLUGIN_LOAD);
int rc = SUDO_RC_ERROR;
if (_python_plugin_register_plugin_in_py_ctx() != SUDO_RC_OK)
goto cleanup;
plugin_ctx->py_interpreter = Py_NewInterpreter();
if (plugin_ctx->py_interpreter == NULL) {
goto cleanup;
}
PyThreadState_Swap(plugin_ctx->py_interpreter);
if (!sudo_conf_developer_mode() && sudo_module_register_importblocker() < 0) {
py_log_last_error(NULL);
debug_return_int(SUDO_RC_ERROR);
}
const char *module_path = _lookup_value(plugin_options, "ModulePath");
if (module_path == NULL) {
py_sudo_log(SUDO_CONV_ERROR_MSG, "No python module path is specified. "
"Use 'ModulePath' plugin config option in 'sudo.conf'\n", module_path);
goto cleanup;
}
sudo_debug_printf(SUDO_DEBUG_DEBUG, "Loading python module from path '%s'", module_path);
plugin_ctx->py_module = _import_module(module_path);
if (plugin_ctx->py_module == NULL) {
goto cleanup;
}
const char *plugin_class = _lookup_value(plugin_options, "ClassName");
if (plugin_class == NULL) {
py_sudo_log(SUDO_CONV_ERROR_MSG, "No plugin class is specified for python module '%s'. "
"Use 'ClassName' configuration option in 'sudo.conf'\n", module_path);
goto cleanup;
}
sudo_debug_printf(SUDO_DEBUG_DEBUG, "Using plugin class '%s'", plugin_class);
plugin_ctx->py_class = PyObject_GetAttrString(plugin_ctx->py_module, plugin_class);
if (plugin_ctx->py_class == NULL) {
py_sudo_log(SUDO_CONV_ERROR_MSG, "Failed to find plugin class '%s'\n", plugin_class);
goto cleanup;
}
if (!PyObject_IsSubclass(plugin_ctx->py_class, (PyObject *)sudo_type_Plugin)) {
py_sudo_log(SUDO_CONV_ERROR_MSG, "Plugin class '%s' does not inherit from 'sudo.Plugin'\n", plugin_class);
Py_CLEAR(plugin_ctx->py_class);
goto cleanup;
}
rc = SUDO_RC_OK;
cleanup:
if (plugin_ctx->py_class == NULL) {
py_log_last_error("Failed during loading plugin class");
rc = SUDO_RC_ERROR;
}
debug_return_int(rc);
}
void
python_plugin_deinit(struct PluginContext *plugin_ctx)
{
debug_decl(python_plugin_deinit, PYTHON_DEBUG_PLUGIN_LOAD);
--py_ctx.open_plugin_count;
sudo_debug_printf(SUDO_DEBUG_DIAG, "Closing: %d python plugins left open\n", py_ctx.open_plugin_count);
Py_CLEAR(plugin_ctx->py_instance);
Py_CLEAR(plugin_ctx->py_class);
Py_CLEAR(plugin_ctx->py_module);
if (plugin_ctx->py_interpreter != NULL) {
sudo_debug_printf(SUDO_DEBUG_TRACE, "deinit python interpreter for plugin\n");
Py_EndInterpreter(plugin_ctx->py_interpreter);
}
memset(plugin_ctx, 0, sizeof(*plugin_ctx));
if (py_ctx.open_plugin_count <= 0) {
if (Py_IsInitialized()) {
sudo_debug_printf(SUDO_DEBUG_NOTICE, "Closing: deinit python interpreter\n");
// we need to call finalize from the main interpreter
PyThreadState_Swap(py_ctx.py_main_interpreter);
Py_Finalize();
}
python_debug_deregister();
py_ctx_reset();
}
debug_return;
}
PyObject *
python_plugin_api_call(struct PluginContext *plugin_ctx, const char *func_name, PyObject *py_args)
{
debug_decl(python_plugin_api_call, PYTHON_DEBUG_PY_CALLS);
// Note: call fails if py_args is an empty tuple. Passing no arguments works passing NULL
// instead. So having such must be handled as valid. (See policy_plugin.validate())
if (py_args == NULL && PyErr_Occurred()) {
py_sudo_log(SUDO_CONV_ERROR_MSG, "Failed to build arguments for python plugin API call '%s'\n", func_name);
py_log_last_error(NULL);
debug_return_ptr(NULL);
}
PyObject *py_callable = NULL;
py_callable = PyObject_GetAttrString(plugin_ctx->py_instance, func_name);
if (py_callable == NULL) {
Py_CLEAR(py_args);
debug_return_ptr(NULL);
}
py_debug_python_call(python_plugin_name(plugin_ctx), func_name,
py_args, NULL, PYTHON_DEBUG_PY_CALLS);
PyObject *py_result = PyObject_CallObject(py_callable, py_args);
Py_CLEAR(py_args);
Py_CLEAR(py_callable);
py_debug_python_result(python_plugin_name(plugin_ctx), func_name,
py_result, PYTHON_DEBUG_PY_CALLS);
if (py_result == NULL) {
py_log_last_error(NULL);
}
debug_return_ptr(py_result);
}
int
python_plugin_rc_to_int(PyObject *py_result)
{
debug_decl(python_plugin_rc_to_int, PYTHON_DEBUG_PY_CALLS);
if (py_result == NULL)
debug_return_int(SUDO_RC_ERROR);
if (py_result == Py_None)
debug_return_int(SUDO_RC_OK);
debug_return_int((int)PyLong_AsLong(py_result));
}
int
python_plugin_api_rc_call(struct PluginContext *plugin_ctx, const char *func_name, PyObject *py_args)
{
debug_decl(python_plugin_api_rc_call, PYTHON_DEBUG_PY_CALLS);
PyObject *py_result = python_plugin_api_call(plugin_ctx, func_name, py_args);
int rc = python_plugin_rc_to_int(py_result);
Py_XDECREF(py_result);
debug_return_int(rc);
}
int
python_plugin_show_version(struct PluginContext *plugin_ctx, const char *python_callback_name, int is_verbose)
{
debug_decl(python_plugin_show_version, PYTHON_DEBUG_CALLBACKS);
debug_return_int(python_plugin_api_rc_call(plugin_ctx, python_callback_name,
Py_BuildValue("(i)", is_verbose)));
}
void
python_plugin_close(struct PluginContext *plugin_ctx, const char *python_callback_name, int exit_status, int error)
{
debug_decl(python_plugin_close, PYTHON_DEBUG_CALLBACKS);
PyThreadState_Swap(plugin_ctx->py_interpreter);
if (!plugin_ctx->call_close) {
sudo_debug_printf(SUDO_DEBUG_INFO, "Skipping close call, because there was no command run\n");
} else if (!PyObject_HasAttrString(plugin_ctx->py_instance, python_callback_name)) {
sudo_debug_printf(SUDO_DEBUG_INFO, "Python plugin function 'close' is skipped (not present)\n");
} else {
PyObject *py_result = python_plugin_api_call(plugin_ctx, python_callback_name,
Py_BuildValue("(ii)", error == 0 ? exit_status : -1, error));
Py_XDECREF(py_result);
}
python_plugin_deinit(plugin_ctx);
debug_return;
}
void
python_plugin_mark_callback_optional(struct PluginContext *plugin_ctx,
const char *function_name, void **function)
{
if (!PyObject_HasAttrString(plugin_ctx->py_instance, function_name)) {
debug_decl_vars(python_plugin_mark_callback_optional, PYTHON_DEBUG_PY_CALLS);
sudo_debug_printf(SUDO_DEBUG_INFO, "%s function '%s' is not implemented\n",
Py_TYPENAME(plugin_ctx->py_instance), function_name);
*function = NULL;
}
}
const char *
python_plugin_name(struct PluginContext *plugin_ctx)
{
debug_decl(python_plugin_name, PYTHON_DEBUG_INTERNAL);
const char *name = "(NULL)";
if (plugin_ctx == NULL || !PyType_Check(plugin_ctx->py_class))
debug_return_const_str(name);
debug_return_const_str(((PyTypeObject *)(plugin_ctx->py_class))->tp_name);
}