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55bb57e0 PP |
1 | /* |
2 | * plugin-python.c | |
3 | * | |
4 | * Babeltrace Plugin (Python) | |
5 | * | |
6 | * Copyright 2017 Philippe Proulx <pproulx@efficios.com> | |
7 | * | |
8 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
9 | * of this software and associated documentation files (the "Software"), to deal | |
10 | * in the Software without restriction, including without limitation the rights | |
11 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
12 | * copies of the Software, and to permit persons to whom the Software is | |
13 | * furnished to do so, subject to the following conditions: | |
14 | * | |
15 | * The above copyright notice and this permission notice shall be included in | |
16 | * all copies or substantial portions of the Software. | |
17 | * | |
18 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
19 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
20 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
21 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
22 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
23 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
24 | * SOFTWARE. | |
25 | */ | |
26 | ||
27 | #include <babeltrace/babeltrace-internal.h> | |
28 | #include <babeltrace/compiler.h> | |
29 | #include <babeltrace/ref.h> | |
30 | #include <babeltrace/plugin/plugin-internal.h> | |
31 | #include <babeltrace/plugin/plugin-internal.h> | |
32 | #include <babeltrace/component/component-class-internal.h> | |
33 | #include <stdlib.h> | |
34 | #include <signal.h> | |
35 | #include <Python.h> | |
36 | ||
37 | #define PYTHON_PLUGIN_FILE_PREFIX "bt_plugin_" | |
38 | #define PYTHON_PLUGIN_FILE_PREFIX_LEN (sizeof(PYTHON_PLUGIN_FILE_PREFIX) - 1) | |
39 | #define PYTHON_PLUGIN_FILE_EXT ".py" | |
40 | #define PYTHON_PLUGIN_FILE_EXT_LEN (sizeof(PYTHON_PLUGIN_FILE_EXT) - 1) | |
41 | ||
42 | enum python_state { | |
43 | /* init_python() not called yet */ | |
44 | PYTHON_STATE_NOT_INITED, | |
45 | ||
46 | /* init_python() called once with success */ | |
47 | PYTHON_STATE_FULLY_INITIALIZED, | |
48 | ||
49 | /* init_python() called once without success */ | |
50 | PYTHON_STATE_CANNOT_INITIALIZE, | |
51 | } python_state = PYTHON_STATE_NOT_INITED; | |
52 | ||
53 | static PyObject *py_try_load_plugin_module_func = NULL; | |
54 | ||
55 | static | |
56 | void print_python_traceback_verbose(void) | |
57 | { | |
58 | if (Py_IsInitialized() && PyErr_Occurred() && babeltrace_verbose) { | |
59 | PyErr_Print(); | |
60 | } | |
61 | } | |
62 | ||
63 | static | |
64 | void pyerr_clear(void) | |
65 | { | |
66 | if (Py_IsInitialized()) { | |
67 | PyErr_Clear(); | |
68 | } | |
69 | } | |
70 | ||
71 | static | |
72 | void init_python(void) | |
73 | { | |
74 | PyObject *py_bt2_py_plugin_mod = NULL; | |
75 | const char *dis_python_env; | |
76 | sighandler_t old_sigint = signal(SIGINT, SIG_DFL); | |
77 | ||
78 | if (python_state != PYTHON_STATE_NOT_INITED) { | |
79 | goto end; | |
80 | } | |
81 | ||
82 | /* | |
83 | * User can disable Python plugin support with the | |
84 | * BABELTRACE_DISABLE_PYTHON_PLUGINS environment variable set to | |
85 | * 1. | |
86 | */ | |
87 | dis_python_env = getenv("BABELTRACE_DISABLE_PYTHON_PLUGINS"); | |
88 | if (dis_python_env && dis_python_env[0] == '1' && | |
89 | dis_python_env[1] == '\0') { | |
90 | printf_verbose("Python plugin support is disabled by BABELTRACE_DISABLE_PYTHON_PLUGINS environment variable\n"); | |
91 | python_state = PYTHON_STATE_CANNOT_INITIALIZE; | |
92 | goto end; | |
93 | } | |
94 | ||
95 | if (!Py_IsInitialized()) { | |
96 | Py_InitializeEx(0); | |
97 | printf_verbose("Initialized Python:\n%s\n", Py_GetVersion()); | |
98 | } | |
99 | ||
100 | py_bt2_py_plugin_mod = PyImport_ImportModule("bt2.py_plugin"); | |
101 | if (!py_bt2_py_plugin_mod) { | |
102 | printf_verbose("Cannot import bt2.py_plugin Python module\n"); | |
103 | python_state = PYTHON_STATE_CANNOT_INITIALIZE; | |
104 | goto end; | |
105 | } | |
106 | ||
107 | py_try_load_plugin_module_func = | |
108 | PyObject_GetAttrString(py_bt2_py_plugin_mod, "_try_load_plugin_module"); | |
109 | if (!py_try_load_plugin_module_func) { | |
110 | printf_verbose("Cannot get _try_load_plugin_module attribute from bt2.py_plugin Python module\n"); | |
111 | python_state = PYTHON_STATE_CANNOT_INITIALIZE; | |
112 | goto end; | |
113 | } | |
114 | ||
115 | python_state = PYTHON_STATE_FULLY_INITIALIZED; | |
116 | ||
117 | end: | |
118 | if (old_sigint != SIG_ERR) { | |
119 | (void) signal(SIGINT, old_sigint); | |
120 | } | |
121 | ||
122 | print_python_traceback_verbose(); | |
123 | pyerr_clear(); | |
124 | Py_XDECREF(py_bt2_py_plugin_mod); | |
125 | return; | |
126 | } | |
127 | ||
128 | __attribute__((destructor)) static | |
129 | void fini_python(void) { | |
130 | if (Py_IsInitialized()) { | |
131 | if (py_try_load_plugin_module_func) { | |
132 | Py_DECREF(py_try_load_plugin_module_func); | |
133 | py_try_load_plugin_module_func = NULL; | |
134 | } | |
135 | ||
136 | Py_Finalize(); | |
137 | } | |
138 | ||
139 | python_state = PYTHON_STATE_NOT_INITED; | |
140 | } | |
141 | ||
142 | static | |
143 | struct bt_plugin *bt_plugin_from_python_plugin_info(PyObject *plugin_info) | |
144 | { | |
145 | struct bt_plugin *plugin = NULL; | |
146 | PyObject *py_name = NULL; | |
147 | PyObject *py_author = NULL; | |
148 | PyObject *py_description = NULL; | |
149 | PyObject *py_license = NULL; | |
150 | PyObject *py_version = NULL; | |
151 | PyObject *py_comp_class_addrs = NULL; | |
152 | const char *name = NULL; | |
153 | const char *author = NULL; | |
154 | const char *description = NULL; | |
155 | const char *license = NULL; | |
156 | unsigned int major = 0, minor = 0, patch = 0; | |
157 | const char *version_extra = NULL; | |
158 | int ret; | |
159 | ||
160 | assert(plugin_info); | |
161 | assert(python_state == PYTHON_STATE_FULLY_INITIALIZED); | |
162 | py_name = PyObject_GetAttrString(plugin_info, "name"); | |
163 | if (!py_name) { | |
164 | printf_verbose("Cannot find `name` attribute in plugin info\n"); | |
165 | goto error; | |
166 | } | |
167 | ||
168 | py_author = PyObject_GetAttrString(plugin_info, "author"); | |
169 | if (!py_author) { | |
170 | printf_verbose("Cannot find `author` attribute in plugin info\n"); | |
171 | goto error; | |
172 | } | |
173 | ||
174 | py_description = PyObject_GetAttrString(plugin_info, "description"); | |
175 | if (!py_description) { | |
176 | printf_verbose("Cannot find `description` attribute in plugin info\n"); | |
177 | goto error; | |
178 | } | |
179 | ||
180 | py_license = PyObject_GetAttrString(plugin_info, "license"); | |
181 | if (!py_license) { | |
182 | printf_verbose("Cannot find `license` attribute in plugin info\n"); | |
183 | goto error; | |
184 | } | |
185 | ||
186 | py_version = PyObject_GetAttrString(plugin_info, "version"); | |
187 | if (!py_version) { | |
188 | printf_verbose("Cannot find `version` attribute in plugin info\n"); | |
189 | goto error; | |
190 | } | |
191 | ||
192 | py_comp_class_addrs = PyObject_GetAttrString(plugin_info, | |
193 | "comp_class_addrs"); | |
194 | if (!py_comp_class_addrs) { | |
195 | printf_verbose("Cannot find `comp_class_addrs` attribute in plugin info\n"); | |
196 | goto error; | |
197 | } | |
198 | ||
199 | if (PyUnicode_Check(py_name)) { | |
200 | name = PyUnicode_AsUTF8(py_name); | |
201 | if (!name) { | |
202 | printf_verbose("Cannot decode plugin name string\n"); | |
203 | goto error; | |
204 | } | |
205 | } else { | |
206 | /* Plugin name is mandatory */ | |
207 | printf_verbose("Plugin name is not a string\n"); | |
208 | goto error; | |
209 | } | |
210 | ||
211 | if (PyUnicode_Check(py_author)) { | |
212 | author = PyUnicode_AsUTF8(py_author); | |
213 | if (!author) { | |
214 | printf_verbose("Cannot decode plugin author string\n"); | |
215 | goto error; | |
216 | } | |
217 | } | |
218 | ||
219 | if (PyUnicode_Check(py_description)) { | |
220 | description = PyUnicode_AsUTF8(py_description); | |
221 | if (!description) { | |
222 | printf_verbose("Cannot decode plugin description string\n"); | |
223 | goto error; | |
224 | } | |
225 | } | |
226 | ||
227 | if (PyUnicode_Check(py_license)) { | |
228 | license = PyUnicode_AsUTF8(py_license); | |
229 | if (!license) { | |
230 | printf_verbose("Cannot decode plugin license string\n"); | |
231 | goto error; | |
232 | } | |
233 | } | |
234 | ||
235 | if (PyTuple_Check(py_version)) { | |
236 | if (PyTuple_Size(py_version) >= 3) { | |
237 | PyObject *py_major = PyTuple_GetItem(py_version, 0); | |
238 | PyObject *py_minor = PyTuple_GetItem(py_version, 1); | |
239 | PyObject *py_patch = PyTuple_GetItem(py_version, 2); | |
240 | ||
241 | assert(py_major); | |
242 | assert(py_minor); | |
243 | assert(py_patch); | |
244 | ||
245 | if (PyLong_Check(py_major)) { | |
246 | major = PyLong_AsUnsignedLong(py_major); | |
247 | } | |
248 | ||
249 | if (PyLong_Check(py_minor)) { | |
250 | minor = PyLong_AsUnsignedLong(py_minor); | |
251 | } | |
252 | ||
253 | if (PyLong_Check(py_patch)) { | |
254 | patch = PyLong_AsUnsignedLong(py_patch); | |
255 | } | |
256 | ||
257 | if (PyErr_Occurred()) { | |
258 | /* Overflow error, most probably */ | |
259 | printf_verbose("Invalid plugin version format\n"); | |
260 | goto error; | |
261 | } | |
262 | } | |
263 | ||
264 | if (PyTuple_Size(py_version) >= 4) { | |
265 | PyObject *py_extra = PyTuple_GetItem(py_version, 3); | |
266 | ||
267 | assert(py_extra); | |
268 | ||
269 | if (PyUnicode_Check(py_extra)) { | |
270 | version_extra = PyUnicode_AsUTF8(py_extra); | |
271 | if (!version_extra) { | |
272 | printf_verbose("Cannot decode plugin version's extra string\n"); | |
273 | goto error; | |
274 | } | |
275 | } | |
276 | } | |
277 | } | |
278 | ||
279 | plugin = bt_plugin_create_empty(BT_PLUGIN_TYPE_PYTHON); | |
280 | if (!plugin) { | |
281 | goto error; | |
282 | } | |
283 | ||
284 | bt_plugin_set_name(plugin, name); | |
285 | ||
286 | if (description) { | |
287 | bt_plugin_set_description(plugin, description); | |
288 | } | |
289 | ||
290 | if (author) { | |
291 | bt_plugin_set_author(plugin, author); | |
292 | } | |
293 | ||
294 | if (license) { | |
295 | bt_plugin_set_license(plugin, license); | |
296 | } | |
297 | ||
298 | bt_plugin_set_version(plugin, major, minor, patch, version_extra); | |
299 | ||
300 | if (PyList_Check(py_comp_class_addrs)) { | |
301 | size_t i; | |
302 | ||
303 | for (i = 0; i < PyList_Size(py_comp_class_addrs); i++) { | |
304 | struct bt_component_class *comp_class; | |
305 | PyObject *py_comp_class_addr; | |
306 | ||
307 | py_comp_class_addr = | |
308 | PyList_GetItem(py_comp_class_addrs, i); | |
309 | assert(py_comp_class_addr); | |
310 | if (PyLong_Check(py_comp_class_addr)) { | |
311 | comp_class = (struct bt_component_class *) | |
312 | PyLong_AsUnsignedLongLong(py_comp_class_addr); | |
313 | } else { | |
314 | printf_verbose("Component class address #%zu: not an integer\n", | |
315 | i); | |
316 | continue; | |
317 | } | |
318 | ||
319 | ret = bt_plugin_add_component_class(plugin, comp_class); | |
320 | if (ret < 0) { | |
321 | printf_verbose("Cannot add component class #%zu\n", | |
322 | i); | |
323 | continue; | |
324 | } | |
325 | } | |
326 | } | |
327 | ||
328 | bt_plugin_freeze(plugin); | |
329 | ||
330 | goto end; | |
331 | ||
332 | error: | |
333 | print_python_traceback_verbose(); | |
334 | pyerr_clear(); | |
335 | BT_PUT(plugin); | |
336 | ||
337 | end: | |
338 | Py_XDECREF(py_name); | |
339 | Py_XDECREF(py_author); | |
340 | Py_XDECREF(py_description); | |
341 | Py_XDECREF(py_license); | |
342 | Py_XDECREF(py_version); | |
343 | Py_XDECREF(py_comp_class_addrs); | |
344 | return plugin; | |
345 | } | |
346 | ||
347 | BT_HIDDEN | |
348 | struct bt_plugin **bt_plugin_python_create_all_from_file(const char *path) | |
349 | { | |
350 | struct bt_plugin **plugins = NULL; | |
351 | PyObject *py_plugin_info = NULL; | |
352 | gchar *basename = NULL; | |
353 | size_t path_len; | |
354 | ||
355 | assert(path); | |
356 | ||
357 | if (python_state == PYTHON_STATE_CANNOT_INITIALIZE) { | |
358 | /* | |
359 | * We do not even care about the rest of the function | |
360 | * here because we already know Python cannot be fully | |
361 | * initialized. | |
362 | */ | |
363 | goto error; | |
364 | } | |
365 | ||
366 | path_len = strlen(path); | |
367 | ||
368 | /* File name ends with `.py` */ | |
369 | if (strncmp(path + path_len - PYTHON_PLUGIN_FILE_EXT_LEN, | |
370 | PYTHON_PLUGIN_FILE_EXT, | |
371 | PYTHON_PLUGIN_FILE_EXT_LEN) != 0) { | |
372 | printf_verbose("Skipping non-Python file: `%s`\n", | |
373 | path); | |
374 | goto error; | |
375 | } | |
376 | ||
377 | /* File name starts with `bt_plugin_` */ | |
378 | basename = g_path_get_basename(path); | |
379 | if (!basename) { | |
380 | goto error; | |
381 | } | |
382 | ||
383 | if (strncmp(basename, PYTHON_PLUGIN_FILE_PREFIX, | |
384 | PYTHON_PLUGIN_FILE_PREFIX_LEN) != 0) { | |
385 | printf_verbose("Skipping Python file not starting with `%s`: `%s`\n", | |
386 | PYTHON_PLUGIN_FILE_PREFIX, path); | |
387 | goto error; | |
388 | } | |
389 | ||
390 | /* | |
391 | * Initialize Python now. | |
392 | * | |
393 | * This is not done in the library contructor because the | |
394 | * interpreter is somewhat slow to initialize. If you don't | |
395 | * have any potential Python plugins, you don't need to endure | |
396 | * this waiting time everytime you load the library. | |
397 | */ | |
398 | init_python(); | |
399 | if (python_state != PYTHON_STATE_FULLY_INITIALIZED) { | |
400 | /* | |
401 | * For some reason we cannot initialize Python, | |
402 | * import the required modules, and get the required | |
403 | * attributes from them. | |
404 | */ | |
405 | goto error; | |
406 | } | |
407 | ||
408 | /* | |
409 | * Call bt2.py_plugin._try_load_plugin_module() with this path | |
410 | * to get plugin info if the plugin is loadable and complete. | |
411 | * This function returns None when there's an error, but just in | |
412 | * case we also manually clear the last Python error state. | |
413 | */ | |
414 | py_plugin_info = PyObject_CallFunction(py_try_load_plugin_module_func, | |
415 | "(s)", path); | |
416 | if (!py_plugin_info || py_plugin_info == Py_None) { | |
417 | printf_verbose("Cannot load Python plugin `%s`:\n", path); | |
418 | print_python_traceback_verbose(); | |
419 | PyErr_Clear(); | |
420 | goto error; | |
421 | } | |
422 | ||
423 | /* | |
424 | * Get bt_plugin from plugin info object. | |
425 | * | |
426 | * calloc(2, ...) because a single Python plugin file always | |
427 | * provides a single Babeltrace plugin (second item is the | |
428 | * sentinel). | |
429 | */ | |
430 | plugins = calloc(2, sizeof(*plugins)); | |
431 | if (!plugins) { | |
432 | goto error; | |
433 | } | |
434 | ||
435 | plugins[0] = bt_plugin_from_python_plugin_info(py_plugin_info); | |
436 | if (!plugins[0]) { | |
437 | goto error; | |
438 | } | |
439 | ||
440 | bt_plugin_set_path(plugins[0], path); | |
441 | goto end; | |
442 | ||
443 | error: | |
444 | if (plugins) { | |
445 | BT_PUT(plugins[0]); | |
446 | free(plugins); | |
447 | plugins = NULL; | |
448 | } | |
449 | ||
450 | end: | |
451 | Py_XDECREF(py_plugin_info); | |
452 | g_free(basename); | |
453 | return plugins; | |
454 | } |