diff options
Diffstat (limited to '')
| -rw-r--r-- | plugins/python/pyhelpers.c | 568 |
1 files changed, 568 insertions, 0 deletions
diff --git a/plugins/python/pyhelpers.c b/plugins/python/pyhelpers.c new file mode 100644 index 0000000..6b235f3 --- /dev/null +++ b/plugins/python/pyhelpers.c @@ -0,0 +1,568 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2019-2020 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 "pyhelpers.h" + +#include <pwd.h> +#include <signal.h> +#include "pathnames.h" + +static int +_sudo_printf_default(int msg_type, const char *fmt, ...) +{ + FILE *fp = stdout; + FILE *ttyfp = NULL; + va_list ap; + int len; + + if (ISSET(msg_type, SUDO_CONV_PREFER_TTY)) { + /* Try writing to /dev/tty first. */ + ttyfp = fopen(_PATH_TTY, "w"); + } + + switch (msg_type & 0xff) { + case SUDO_CONV_ERROR_MSG: + fp = stderr; + FALLTHROUGH; + case SUDO_CONV_INFO_MSG: + va_start(ap, fmt); + len = vfprintf(ttyfp ? ttyfp : fp, fmt, ap); + va_end(ap); + break; + default: + len = -1; + errno = EINVAL; + break; + } + + if (ttyfp != NULL) + fclose(ttyfp); + + return len; +} + + +struct PythonContext py_ctx = { + .sudo_log = &_sudo_printf_default, +}; + + +int +py_is_sudo_log_available(void) +{ + debug_decl(py_is_sudo_log_available, PYTHON_DEBUG_INTERNAL); + debug_return_int(py_ctx.sudo_log != &_sudo_printf_default); +} + +char * +py_join_str_list(PyObject *py_str_list, const char *separator) +{ + debug_decl(py_join_str_list, PYTHON_DEBUG_INTERNAL); + + char *result = NULL; + PyObject *py_separator = NULL; + PyObject *py_str = NULL; + + py_separator = PyUnicode_FromString(separator); + if (py_separator == NULL) + goto cleanup; + + py_str = PyObject_CallMethod(py_separator, "join", "(O)", py_str_list); + if (py_str == NULL) { + goto cleanup; + } + + const char *str = PyUnicode_AsUTF8(py_str); + if (str != NULL) { + result = strdup(str); + } + +cleanup: + Py_XDECREF(py_str); + Py_XDECREF(py_separator); + + debug_return_str(result); +} + +char * +py_create_traceback_string(PyObject *py_traceback) +{ + debug_decl(py_create_traceback_string, PYTHON_DEBUG_INTERNAL); + if (py_traceback == NULL) + debug_return_str(strdup("")); + + char* traceback = NULL; + + + PyObject *py_traceback_module = PyImport_ImportModule("traceback"); + if (py_traceback_module == NULL) { + PyErr_Clear(); // do not care, we just won't show backtrace + } else { + PyObject *py_traceback_str_list = PyObject_CallMethod(py_traceback_module, "format_tb", "(O)", py_traceback); + + if (py_traceback_str_list != NULL) { + traceback = py_join_str_list(py_traceback_str_list, ""); + Py_DECREF(py_traceback_str_list); + } + + Py_CLEAR(py_traceback_module); + } + + debug_return_str(traceback ? traceback : strdup("")); +} + +void +py_log_last_error(const char *context_message) +{ + debug_decl(py_log_last_error, PYTHON_DEBUG_INTERNAL); + if (!PyErr_Occurred()) { + py_sudo_log(SUDO_CONV_ERROR_MSG, "%s\n", context_message); + debug_return; + } + + PyObject *py_type = NULL, *py_message = NULL, *py_traceback = NULL; + PyErr_Fetch(&py_type, &py_message, &py_traceback); + + char *message = py_message ? py_create_string_rep(py_message) : NULL; + + py_sudo_log(SUDO_CONV_ERROR_MSG, "%s%s%s\n", + context_message ? context_message : "", + context_message && *context_message ? ": " : "", + message ? message : "(NULL)"); + free(message); + + if (py_traceback != NULL) { + char *traceback = py_create_traceback_string(py_traceback); + py_sudo_log(SUDO_CONV_INFO_MSG, "Traceback:\n%s\n", traceback); + free(traceback); + } + + Py_XDECREF(py_type); + Py_XDECREF(py_message); + Py_XDECREF(py_traceback); + debug_return; +} + +PyObject * +py_str_array_to_tuple_with_count(Py_ssize_t count, char * const strings[]) +{ + debug_decl(py_str_array_to_tuple_with_count, PYTHON_DEBUG_INTERNAL); + + PyObject *py_argv = PyTuple_New(count); + if (py_argv == NULL) + debug_return_ptr(NULL); + + for (int i = 0; i < count; ++i) { + PyObject *py_arg = PyUnicode_FromString(strings[i]); + if (py_arg == NULL || PyTuple_SetItem(py_argv, i, py_arg) != 0) { + Py_CLEAR(py_argv); + break; + } + } + + debug_return_ptr(py_argv); +} + +PyObject * +py_str_array_to_tuple(char * const strings[]) +{ + debug_decl(py_str_array_to_tuple, PYTHON_DEBUG_INTERNAL); + + // find the item count ("strings" ends with NULL terminator): + Py_ssize_t count = 0; + if (strings != NULL) { + while (strings[count] != NULL) + ++count; + } + + debug_return_ptr(py_str_array_to_tuple_with_count(count, strings)); +} + +char ** +py_str_array_from_tuple(PyObject *py_tuple) +{ + debug_decl(py_str_array_from_tuple, PYTHON_DEBUG_INTERNAL); + + if (!PyTuple_Check(py_tuple)) { + PyErr_Format(PyExc_ValueError, "%s: value error, argument should be a tuple but it is '%s'", + __func__, Py_TYPENAME(py_tuple)); + debug_return_ptr(NULL); + } + + Py_ssize_t tuple_size = PyTuple_Size(py_tuple); + + // we need an extra 0 at the end + char **result = calloc(Py_SSIZE2SIZE(tuple_size) + 1, sizeof(char*)); + if (result == NULL) { + debug_return_ptr(NULL); + } + + for (int i = 0; i < tuple_size; ++i) { + PyObject *py_value = PyTuple_GetItem(py_tuple, i); + if (py_value == NULL) { + str_array_free(&result); + debug_return_ptr(NULL); + } + + // Note that it can be an "int" or something else as well + char *value = py_create_string_rep(py_value); + if (value == NULL) { + // conversion error is already set + str_array_free(&result); + debug_return_ptr(NULL); + } + result[i] = value; + } + + debug_return_ptr(result); +} + +PyObject * +py_tuple_get(PyObject *py_tuple, Py_ssize_t index, PyTypeObject *expected_type) +{ + debug_decl(py_tuple_get, PYTHON_DEBUG_INTERNAL); + + PyObject *py_item = PyTuple_GetItem(py_tuple, index); + if (py_item == NULL) { + debug_return_ptr(NULL); + } + + if (!PyObject_TypeCheck(py_item, expected_type)) { + PyErr_Format(PyExc_ValueError, "Value error: tuple element %d should " + "be a '%s' (but it is '%s')", + index, expected_type->tp_name, Py_TYPENAME(py_item)); + debug_return_ptr(NULL); + } + + debug_return_ptr(py_item); +} + +PyObject * +py_create_version(unsigned int version) +{ + debug_decl(py_create_version, PYTHON_DEBUG_INTERNAL); + debug_return_ptr(PyUnicode_FromFormat("%d.%d", SUDO_API_VERSION_GET_MAJOR(version), + SUDO_API_VERSION_GET_MINOR(version))); +} + +PyObject * +py_from_passwd(const struct passwd *pwd) +{ + debug_decl(py_from_passwd, PYTHON_DEBUG_INTERNAL); + + if (pwd == NULL) { + debug_return_ptr_pynone; + } + + // Create a tuple similar and convertible to python "struct_passwd" of "pwd" module + debug_return_ptr( + Py_BuildValue("(zziizzz)", pwd->pw_name, pwd->pw_passwd, + pwd->pw_uid, pwd->pw_gid, pwd->pw_gecos, + pwd->pw_dir, pwd->pw_shell) + ); +} + +char * +py_create_string_rep(PyObject *py_object) +{ + debug_decl(py_create_string_rep, PYTHON_DEBUG_INTERNAL); + char *result = NULL; + + if (py_object == NULL) + debug_return_ptr(NULL); + + PyObject *py_string = PyObject_Str(py_object); + if (py_string != NULL) { + const char *bytes = PyUnicode_AsUTF8(py_string); + if (bytes != NULL) { + result = strdup(bytes); + } + } + + Py_XDECREF(py_string); + debug_return_ptr(result); +} + +static void +_py_debug_python_function(const char *class_name, const char *function_name, const char *message, + PyObject *py_args, PyObject *py_kwargs, int subsystem_id) +{ + debug_decl_vars(_py_debug_python_function, subsystem_id); + + if (sudo_debug_needed(SUDO_DEBUG_DIAG)) { + char *args_str = NULL; + char *kwargs_str = NULL; + if (py_args != NULL) { + /* Sort by key for consistent output on Python < 3.6 */ + PyObject *py_args_sorted = NULL; + if (PyDict_Check(py_args)) { + py_args_sorted = PyDict_Items(py_args); + if (py_args_sorted != NULL) { + if (PyList_Sort(py_args_sorted) == 0) { + py_args = py_args_sorted; + } + } + } + args_str = py_create_string_rep(py_args); + if (py_args_sorted != NULL) + Py_DECREF(py_args_sorted); + } + if (py_kwargs != NULL) { + /* Sort by key for consistent output on Python < 3.6 */ + PyObject *py_kwargs_sorted = NULL; + if (PyDict_Check(py_kwargs)) { + py_kwargs_sorted = PyDict_Items(py_kwargs); + if (py_kwargs_sorted != NULL) { + if (PyList_Sort(py_kwargs_sorted) == 0) { + py_kwargs = py_kwargs_sorted; + } + } + } + kwargs_str = py_create_string_rep(py_kwargs); + if (py_kwargs_sorted != NULL) + Py_DECREF(py_kwargs_sorted); + } + + sudo_debug_printf(SUDO_DEBUG_DIAG, "%s.%s %s: %s %s\n", class_name, + function_name, message, args_str ? args_str : "()", + kwargs_str ? kwargs_str : ""); + free(args_str); + free(kwargs_str); + } +} + +void +py_debug_python_call(const char *class_name, const char *function_name, + PyObject *py_args, PyObject *py_kwargs, int subsystem_id) +{ + debug_decl_vars(py_debug_python_call, subsystem_id); + + if (subsystem_id == PYTHON_DEBUG_C_CALLS && sudo_debug_needed(SUDO_DEBUG_INFO)) { + // at this level we also output the callee python script + char *callee_func_name = NULL, *callee_file_name = NULL; + long callee_line_number = -1; + + if (py_get_current_execution_frame(&callee_file_name, &callee_line_number, &callee_func_name) == SUDO_RC_OK) { + sudo_debug_printf(SUDO_DEBUG_INFO, "%s @ %s:%ld calls C function:\n", + callee_func_name, callee_file_name, callee_line_number); + } + + free(callee_func_name); + free(callee_file_name); + } + + _py_debug_python_function(class_name, function_name, "was called with arguments", + py_args, py_kwargs, subsystem_id); +} + +void +py_debug_python_result(const char *class_name, const char *function_name, + PyObject *py_result, int subsystem_id) +{ + if (py_result == NULL) { + debug_decl_vars(py_debug_python_result, subsystem_id); + sudo_debug_printf(SUDO_CONV_ERROR_MSG, "%s.%s call failed\n", + class_name, function_name); + } else { + _py_debug_python_function(class_name, function_name, "returned result", + py_result, NULL, subsystem_id); + } +} + +void +str_array_free(char ***array) +{ + debug_decl(str_array_free, PYTHON_DEBUG_INTERNAL); + + if (*array == NULL) + debug_return; + + for (char **item_ptr = *array; *item_ptr != NULL; ++item_ptr) + free(*item_ptr); + + free(*array); + *array = NULL; + + debug_return; +} + +int +py_get_current_execution_frame(char **file_name, long *line_number, char **function_name) +{ + *file_name = NULL; + *line_number = (long)-1; + *function_name = NULL; + + PyObject *py_err_type = NULL, *py_err_value = NULL, *py_err_traceback = NULL; + PyErr_Fetch(&py_err_type, &py_err_value, &py_err_traceback); + + PyObject *py_frame = NULL, *py_f_code = NULL, + *py_filename = NULL, *py_function_name = NULL; + + PyObject *py_getframe = PySys_GetObject("_getframe"); + if (py_getframe == NULL) + goto cleanup; + + py_frame = PyObject_CallFunction(py_getframe, "i", 0); + if (py_frame == NULL) + goto cleanup; + + *line_number = py_object_get_optional_attr_number(py_frame, "f_lineno"); + + py_f_code = py_object_get_optional_attr(py_frame, "f_code", NULL); + if (py_f_code != NULL) { + py_filename = py_object_get_optional_attr(py_f_code, "co_filename", NULL); + if (py_filename != NULL) + *file_name = strdup(PyUnicode_AsUTF8(py_filename)); + + py_function_name = py_object_get_optional_attr(py_f_code, "co_name", NULL); + if (py_function_name != NULL) + *function_name = strdup(PyUnicode_AsUTF8(py_function_name)); + } + +cleanup: + Py_CLEAR(py_frame); + Py_CLEAR(py_f_code); + Py_CLEAR(py_filename); + Py_CLEAR(py_function_name); + + // we hide every error happening inside this function + PyErr_Restore(py_err_type, py_err_value, py_err_traceback); + + return (*file_name && *function_name && (*line_number >= 0)) ? + SUDO_RC_OK : SUDO_RC_ERROR; +} + +void +py_ctx_reset() +{ + memset(&py_ctx, 0, sizeof(py_ctx)); + py_ctx.sudo_log = &_sudo_printf_default; +} + +int +py_sudo_conv(int num_msgs, const struct sudo_conv_message msgs[], + struct sudo_conv_reply replies[], struct sudo_conv_callback *callback) +{ + /* Enable suspend during password entry. */ + struct sigaction sa, saved_sigtstp; + sigemptyset(&sa.sa_mask); + sa.sa_flags = SA_RESTART; + sa.sa_handler = SIG_DFL; + (void) sigaction(SIGTSTP, &sa, &saved_sigtstp); + + int rc = SUDO_RC_ERROR; + if (py_ctx.sudo_conv != NULL) + rc = py_ctx.sudo_conv((int)num_msgs, msgs, replies, callback); + + /* Restore signal handlers and signal mask. */ + (void) sigaction(SIGTSTP, &saved_sigtstp, NULL); + + return rc; +} + +PyObject * +py_object_get_optional_attr(PyObject *py_object, const char *attr, PyObject *py_default) +{ + if (PyObject_HasAttrString(py_object, attr)) { + return PyObject_GetAttrString(py_object, attr); + } + Py_XINCREF(py_default); // whatever we return will have its refcount incremented + return py_default; +} + +const char * +py_object_get_optional_attr_string(PyObject *py_object, const char *attr_name) +{ + PyObject *py_value = py_object_get_optional_attr(py_object, attr_name, NULL); + if (py_value == NULL) + return NULL; + + const char *value = PyUnicode_AsUTF8(py_value); + Py_CLEAR(py_value); // Note, the object still has reference to the attribute + return value; +} + +long long +py_object_get_optional_attr_number(PyObject *py_object, const char *attr_name) +{ + PyObject *py_value = py_object_get_optional_attr(py_object, attr_name, NULL); + if (py_value == NULL) + return -1; + + long long value = PyLong_AsLongLong(py_value); + Py_CLEAR(py_value); + return value; +} + +void +py_object_set_attr_number(PyObject *py_object, const char *attr_name, long long number) +{ + PyObject *py_number = PyLong_FromLong(number); + if (py_number == NULL) + return; + + PyObject_SetAttrString(py_object, attr_name, py_number); + Py_CLEAR(py_number); +} + +void +py_object_set_attr_string(PyObject *py_object, const char *attr_name, const char *value) +{ + PyObject *py_value = PyUnicode_FromString(value); + if (py_value == NULL) + return; + + PyObject_SetAttrString(py_object, attr_name, py_value); + Py_CLEAR(py_value); +} + +PyObject * +py_dict_create_string_int(size_t count, struct key_value_str_int *key_values) +{ + debug_decl(py_dict_create_string_int, PYTHON_DEBUG_INTERNAL); + + PyObject *py_value = NULL; + PyObject *py_dict = PyDict_New(); + if (py_dict == NULL) + goto cleanup; + + for (size_t i = 0; i < count; ++i) { + py_value = PyLong_FromLong(key_values[i].value); + if (py_value == NULL) + goto cleanup; + + if (PyDict_SetItemString(py_dict, key_values[i].key, py_value) < 0) + goto cleanup; + + Py_CLEAR(py_value); + } + +cleanup: + if (PyErr_Occurred()) { + Py_CLEAR(py_dict); + } + Py_CLEAR(py_value); + + debug_return_ptr(py_dict); +} |