src/python.c

   1 /**
   2  * collectd - src/python.c
   3  * Copyright (C) 2009  Sven Trenkel
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *   Sven Trenkel <collectd at semidefinite.de>
  25  **/
  26
  27 #include <Python.h>
  28 #include <structmember.h>
  29
  30 #include <signal.h>
  31
  32 #include "collectd.h"
  33
  34 #include "common.h"
  35
  36 #include "cpython.h"
  37
  38 typedef struct cpy_callback_s {
  39         char *name;
  40         PyObject *callback;
  41         PyObject *data;
  42         struct cpy_callback_s *next;
  43 } cpy_callback_t;
  44
  45 static char log_doc[] = "This function sends a string to all logging plugins.";
  46
  47 static char get_ds_doc[] = "get_dataset(name) -> definition\n"
  48                 "\n"
  49                 "Returns the definition of a dataset specified by name.\n"
  50                 "\n"
  51                 "'name' is a string specifying the dataset to query.\n"
  52                 "'definition' is a list of 4-tuples. Every tuple represents a \n"
  53                 "    data source within the data set and its 4 values are the \n"
  54                 "    name, type, min and max value.\n"
  55                 "    'name' is a string.\n"
  56                 "    'type' is a string that is equal to either DS_TYPE_COUNTER,\n"
  57                 "        DS_TYPE_GAUGE, DS_TYPE_DERIVE or DS_TYPE_ABSOLUTE.\n"
  58                 "    'min' and 'max' are either a float or None.";
  59
  60 static char flush_doc[] = "flush([plugin][, timeout][, identifier]) -> None\n"
  61                 "\n"
  62                 "Flushes the cache of another plugin.";
  63
  64 static char unregister_doc[] = "Unregisters a callback. This function needs exactly one parameter either\n"
  65                 "the function to unregister or the callback identifier to unregister.";
  66
  67 static char reg_log_doc[] = "register_log(callback[, data][, name]) -> identifier\n"
  68                 "\n"
  69                 "Register a callback function for log messages.\n"
  70                 "\n"
  71                 "'callback' is a callable object that will be called every time something\n"
  72                 "    is logged.\n"
  73                 "'data' is an optional object that will be passed back to the callback\n"
  74                 "    function every time it is called.\n"
  75                 "'name' is an optional identifier for this callback. The default name\n"
  76                 "    is 'python.<module>'.\n"
  77                 "    Every callback needs a unique identifier, so if you want to\n"
  78                 "    register this callback multiple time from the same module you need\n"
  79                 "    to specify a name here.\n"
  80                 "'identifier' is the full identifier assigned to this callback.\n"
  81                 "\n"
  82                 "The callback function will be called with two or three parameters:\n"
  83                 "severity: An integer that should be compared to the LOG_ constants.\n"
  84                 "message: The text to be logged.\n"
  85                 "data: The optional data parameter passed to the register function.\n"
  86                 "    If the parameter was omitted it will be omitted here, too.";
  87
  88 static char reg_init_doc[] = "register_init(callback[, data][, name]) -> identifier\n"
  89                 "\n"
  90                 "Register a callback function that will be executed once after the config.\n"
  91                 "file has been read, all plugins heve been loaded and the collectd has\n"
  92                 "forked into the background.\n"
  93                 "\n"
  94                 "'callback' is a callable object that will be executed.\n"
  95                 "'data' is an optional object that will be passed back to the callback\n"
  96                 "    function when it is called.\n"
  97                 "'name' is an optional identifier for this callback. The default name\n"
  98                 "    is 'python.<module>'.\n"
  99                 "    Every callback needs a unique identifier, so if you want to\n"
 100                 "    register this callback multiple time from the same module you need\n"
 101                 "    to specify a name here.\n"
 102                 "'identifier' is the full identifier assigned to this callback.\n"
 103                 "\n"
 104                 "The callback function will be called without parameters, except for\n"
 105                 "data if it was supplied.";
 106
 107 static char reg_config_doc[] = "register_config(callback[, data][, name]) -> identifier\n"
 108                 "\n"
 109                 "Register a callback function for config file entries.\n"
 110                 "'callback' is a callable object that will be called for every config block.\n"
 111                 "'data' is an optional object that will be passed back to the callback\n"
 112                 "    function every time it is called.\n"
 113                 "'name' is an optional identifier for this callback. The default name\n"
 114                 "    is 'python.<module>'.\n"
 115                 "    Every callback needs a unique identifier, so if you want to\n"
 116                 "    register this callback multiple time from the same module you need\n"
 117                 "    to specify a name here.\n"
 118                 "'identifier' is the full identifier assigned to this callback.\n"
 119                 "\n"
 120                 "The callback function will be called with one or two parameters:\n"
 121                 "config: A Config object.\n"
 122                 "data: The optional data parameter passed to the register function.\n"
 123                 "    If the parameter was omitted it will be omitted here, too.";
 124
 125 static char reg_read_doc[] = "register_read(callback[, interval][, data][, name]) -> identifier\n"
 126                 "\n"
 127                 "Register a callback function for reading data. It will just be called\n"
 128                 "in a fixed interval to signal that it's time to dispatch new values.\n"
 129                 "'callback' is a callable object that will be called every time something\n"
 130                 "    is logged.\n"
 131                 "'interval' is the number of seconds between between calls to the callback\n"
 132                 "    function. Full float precision is supported here.\n"
 133                 "'data' is an optional object that will be passed back to the callback\n"
 134                 "    function every time it is called.\n"
 135                 "'name' is an optional identifier for this callback. The default name\n"
 136                 "    is 'python.<module>'.\n"
 137                 "    Every callback needs a unique identifier, so if you want to\n"
 138                 "    register this callback multiple time from the same module you need\n"
 139                 "    to specify a name here.\n"
 140                 "'identifier' is the full identifier assigned to this callback.\n"
 141                 "\n"
 142                 "The callback function will be called without parameters, except for\n"
 143                 "data if it was supplied.";
 144
 145 static char reg_write_doc[] = "register_write(callback[, data][, name]) -> identifier\n"
 146                 "\n"
 147                 "Register a callback function to receive values dispatched by other plugins.\n"
 148                 "'callback' is a callable object that will be called every time a value\n"
 149                 "    is dispatched.\n"
 150                 "'data' is an optional object that will be passed back to the callback\n"
 151                 "    function every time it is called.\n"
 152                 "'name' is an optional identifier for this callback. The default name\n"
 153                 "    is 'python.<module>'.\n"
 154                 "    Every callback needs a unique identifier, so if you want to\n"
 155                 "    register this callback multiple time from the same module you need\n"
 156                 "    to specify a name here.\n"
 157                 "'identifier' is the full identifier assigned to this callback.\n"
 158                 "\n"
 159                 "The callback function will be called with one or two parameters:\n"
 160                 "values: A Values object which is a copy of the dispatched values.\n"
 161                 "data: The optional data parameter passed to the register function.\n"
 162                 "    If the parameter was omitted it will be omitted here, too.";
 163
 164 static char reg_notification_doc[] = "register_notification(callback[, data][, name]) -> identifier\n"
 165                 "\n"
 166                 "Register a callback function for notifications.\n"
 167                 "'callback' is a callable object that will be called every time a notification\n"
 168                 "    is dispatched.\n"
 169                 "'data' is an optional object that will be passed back to the callback\n"
 170                 "    function every time it is called.\n"
 171                 "'name' is an optional identifier for this callback. The default name\n"
 172                 "    is 'python.<module>'.\n"
 173                 "    Every callback needs a unique identifier, so if you want to\n"
 174                 "    register this callback multiple time from the same module you need\n"
 175                 "    to specify a name here.\n"
 176                 "'identifier' is the full identifier assigned to this callback.\n"
 177                 "\n"
 178                 "The callback function will be called with one or two parameters:\n"
 179                 "notification: A copy of the notification that was dispatched.\n"
 180                 "data: The optional data parameter passed to the register function.\n"
 181                 "    If the parameter was omitted it will be omitted here, too.";
 182
 183 static char reg_flush_doc[] = "register_flush(callback[, data][, name]) -> identifier\n"
 184                 "\n"
 185                 "Register a callback function for flush messages.\n"
 186                 "'callback' is a callable object that will be called every time a plugin\n"
 187                 "    requests a flush for either this or all plugins.\n"
 188                 "'data' is an optional object that will be passed back to the callback\n"
 189                 "    function every time it is called.\n"
 190                 "'name' is an optional identifier for this callback. The default name\n"
 191                 "    is 'python.<module>'.\n"
 192                 "    Every callback needs a unique identifier, so if you want to\n"
 193                 "    register this callback multiple time from the same module you need\n"
 194                 "    to specify a name here.\n"
 195                 "'identifier' is the full identifier assigned to this callback.\n"
 196                 "\n"
 197                 "The callback function will be called with two or three parameters:\n"
 198                 "timeout: Indicates that only data older than 'timeout' seconds is to\n"
 199                 "    be flushed.\n"
 200                 "id: Specifies which values are to be flushed.\n"
 201                 "data: The optional data parameter passed to the register function.\n"
 202                 "    If the parameter was omitted it will be omitted here, too.";
 203
 204 static char reg_shutdown_doc[] = "register_shutdown(callback[, data][, name]) -> identifier\n"
 205                 "\n"
 206                 "Register a callback function for collectd shutdown.\n"
 207                 "'callback' is a callable object that will be called once collectd is\n"
 208                 "    shutting down.\n"
 209                 "'data' is an optional object that will be passed back to the callback\n"
 210                 "    function if it is called.\n"
 211                 "'name' is an optional identifier for this callback. The default name\n"
 212                 "    is 'python.<module>'.\n"
 213                 "    Every callback needs a unique identifier, so if you want to\n"
 214                 "    register this callback multiple time from the same module you need\n"
 215                 "    to specify a name here.\n"
 216                 "'identifier' is the full identifier assigned to this callback.\n"
 217                 "\n"
 218                 "The callback function will be called with no parameters except for\n"
 219                 "    data if it was supplied.";
 220
 221
 222 static pthread_t main_thread;
 223 static PyOS_sighandler_t python_sigint_handler;
 224 static _Bool do_interactive = 0;
 225
 226 /* This is our global thread state. Python saves some stuff in thread-local
 227  * storage. So if we allow the interpreter to run in the background
 228  * (the scriptwriters might have created some threads from python), we have
 229  * to save the state so we can resume it later after shutdown. */
 230
 231 static PyThreadState *state;
 232
 233 static PyObject *sys_path, *cpy_format_exception;
 234
 235 static cpy_callback_t *cpy_config_callbacks;
 236 static cpy_callback_t *cpy_init_callbacks;
 237 static cpy_callback_t *cpy_shutdown_callbacks;
 238
 239 static void cpy_destroy_user_data(void *data) {
 240         cpy_callback_t *c = data;
 241         free(c->name);
 242         Py_DECREF(c->callback);
 243         Py_XDECREF(c->data);
 244         free(c);
 245 }
 246
 247 /* You must hold the GIL to call this function!
 248  * But if you managed to extract the callback parameter then you probably already do. */
 249
 250 static void cpy_build_name(char *buf, size_t size, PyObject *callback, const char *name) {
 251         const char *module = NULL;
 252         PyObject *mod = NULL;
 253
 254         if (name != NULL) {
 255                 snprintf(buf, size, "python.%s", name);
 256                 return;
 257         }
 258
 259         mod = PyObject_GetAttrString(callback, "__module__"); /* New reference. */
 260         if (mod != NULL)
 261                 module = cpy_unicode_or_bytes_to_string(&mod);
 262
 263         if (module != NULL) {
 264                 snprintf(buf, size, "python.%s", module);
 265                 Py_XDECREF(mod);
 266                 PyErr_Clear();
 267                 return;
 268         }
 269         Py_XDECREF(mod);
 270
 271         snprintf(buf, size, "python.%p", callback);
 272         PyErr_Clear();
 273 }
 274
 275 void cpy_log_exception(const char *context) {
 276         int l = 0;
 277         const char *typename = NULL, *message = NULL;
 278         PyObject *type, *value, *traceback, *tn, *m, *list;
 279
 280         PyErr_Fetch(&type, &value, &traceback);
 281         PyErr_NormalizeException(&type, &value, &traceback);
 282         if (type == NULL) return;
 283         tn = PyObject_GetAttrString(type, "__name__"); /* New reference. */
 284         m = PyObject_Str(value); /* New reference. */
 285         if (tn != NULL)
 286                 typename = cpy_unicode_or_bytes_to_string(&tn);
 287         if (m != NULL)
 288                 message = cpy_unicode_or_bytes_to_string(&m);
 289         if (typename == NULL)
 290                 typename = "NamelessException";
 291         if (message == NULL)
 292                 message = "N/A";
 293         Py_BEGIN_ALLOW_THREADS
 294         ERROR("Unhandled python exception in %s: %s: %s", context, typename, message);
 295         Py_END_ALLOW_THREADS
 296         Py_XDECREF(tn);
 297         Py_XDECREF(m);
 298         if (!cpy_format_exception || !traceback) {
 299                 PyErr_Clear();
 300                 Py_DECREF(type);
 301                 Py_XDECREF(value);
 302                 Py_XDECREF(traceback);
 303                 return;
 304         }
 305         list = PyObject_CallFunction(cpy_format_exception, "NNN", type, value, traceback); /* New reference. Steals references from "type", "value" and "traceback". */
 306         if (list)
 307                 l = PyObject_Length(list);
 308
 309         for (int i = 0; i < l; ++i) {
 310                 PyObject *line;
 311                 char const *msg;
 312                 char *cpy;
 313
 314                 line = PyList_GET_ITEM(list, i); /* Borrowed reference. */
 315                 Py_INCREF(line);
 316
 317                 msg = cpy_unicode_or_bytes_to_string(&line);
 318                 Py_DECREF(line);
 319                 if (msg == NULL)
 320                         continue;
 321
 322                 cpy = strdup(msg);
 323                 if (cpy == NULL)
 324                         continue;
 325
 326                 if (cpy[strlen(cpy) - 1] == '\n')
 327                         cpy[strlen(cpy) - 1] = 0;
 328
 329                 Py_BEGIN_ALLOW_THREADS
 330                 ERROR("%s", cpy);
 331                 Py_END_ALLOW_THREADS
 332
 333                 free(cpy);
 334         }
 335
 336         Py_XDECREF(list);
 337         PyErr_Clear();
 338 }
 339
 340 static int cpy_read_callback(user_data_t *data) {
 341         cpy_callback_t *c = data->data;
 342         PyObject *ret;
 343
 344         CPY_LOCK_THREADS
 345                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 346                 if (ret == NULL) {
 347                         cpy_log_exception("read callback");
 348                 } else {
 349                         Py_DECREF(ret);
 350                 }
 351         CPY_RELEASE_THREADS
 352         if (ret == NULL)
 353                 return 1;
 354         return 0;
 355 }
 356
 357 static int cpy_write_callback(const data_set_t *ds, const value_list_t *value_list, user_data_t *data) {
 358         cpy_callback_t *c = data->data;
 359         PyObject *ret, *list, *temp, *dict = NULL;
 360         Values *v;
 361
 362         CPY_LOCK_THREADS
 363                 list = PyList_New(value_list->values_len); /* New reference. */
 364                 if (list == NULL) {
 365                         cpy_log_exception("write callback");
 366                         CPY_RETURN_FROM_THREADS 0;
 367                 }
 368                 for (size_t i = 0; i < value_list->values_len; ++i) {
 369                         if (ds->ds[i].type == DS_TYPE_COUNTER) {
 370                                 PyList_SetItem(list, i, PyLong_FromUnsignedLongLong(value_list->values[i].counter));
 371                         } else if (ds->ds[i].type == DS_TYPE_GAUGE) {
 372                                 PyList_SetItem(list, i, PyFloat_FromDouble(value_list->values[i].gauge));
 373                         } else if (ds->ds[i].type == DS_TYPE_DERIVE) {
 374                                 PyList_SetItem(list, i, PyLong_FromLongLong(value_list->values[i].derive));
 375                         } else if (ds->ds[i].type == DS_TYPE_ABSOLUTE) {
 376                                 PyList_SetItem(list, i, PyLong_FromUnsignedLongLong(value_list->values[i].absolute));
 377                         } else {
 378                                 Py_BEGIN_ALLOW_THREADS
 379                                 ERROR("cpy_write_callback: Unknown value type %d.", ds->ds[i].type);
 380                                 Py_END_ALLOW_THREADS
 381                                 Py_DECREF(list);
 382                                 CPY_RETURN_FROM_THREADS 0;
 383                         }
 384                         if (PyErr_Occurred() != NULL) {
 385                                 cpy_log_exception("value building for write callback");
 386                                 Py_DECREF(list);
 387                                 CPY_RETURN_FROM_THREADS 0;
 388                         }
 389                 }
 390                 dict = PyDict_New();  /* New reference. */
 391                 if (value_list->meta) {
 392                         int num;
 393                         char **table;
 394                         meta_data_t *meta = value_list->meta;
 395
 396                         num = meta_data_toc(meta, &table);
 397                         for (size_t i = 0; i < num; ++i) {
 398                                 int type;
 399                                 char *string;
 400                                 int64_t si;
 401                                 uint64_t ui;
 402                                 double d;
 403                                 _Bool b;
 404
 405                                 type = meta_data_type(meta, table[i]);
 406                                 if (type == MD_TYPE_STRING) {
 407                                         if (meta_data_get_string(meta, table[i], &string))
 408                                                 continue;
 409                                         temp = cpy_string_to_unicode_or_bytes(string);  /* New reference. */
 410                                         free(string);
 411                                         PyDict_SetItemString(dict, table[i], temp);
 412                                         Py_XDECREF(temp);
 413                                 } else if (type == MD_TYPE_SIGNED_INT) {
 414                                         if (meta_data_get_signed_int(meta, table[i], &si))
 415                                                 continue;
 416                                         temp = PyObject_CallFunctionObjArgs((void *) &SignedType, PyLong_FromLongLong(si), (void *) 0);  /* New reference. */
 417                                         PyDict_SetItemString(dict, table[i], temp);
 418                                         Py_XDECREF(temp);
 419                                 } else if (type == MD_TYPE_UNSIGNED_INT) {
 420                                         if (meta_data_get_unsigned_int(meta, table[i], &ui))
 421                                                 continue;
 422                                         temp = PyObject_CallFunctionObjArgs((void *) &UnsignedType, PyLong_FromUnsignedLongLong(ui), (void *) 0);  /* New reference. */
 423                                         PyDict_SetItemString(dict, table[i], temp);
 424                                         Py_XDECREF(temp);
 425                                 } else if (type == MD_TYPE_DOUBLE) {
 426                                         if (meta_data_get_double(meta, table[i], &d))
 427                                                 continue;
 428                                         temp = PyFloat_FromDouble(d);  /* New reference. */
 429                                         PyDict_SetItemString(dict, table[i], temp);
 430                                         Py_XDECREF(temp);
 431                                 } else if (type == MD_TYPE_BOOLEAN) {
 432                                         if (meta_data_get_boolean(meta, table[i], &b))
 433                                                 continue;
 434                                         if (b)
 435                                                 PyDict_SetItemString(dict, table[i], Py_True);
 436                                         else
 437                                                 PyDict_SetItemString(dict, table[i], Py_False);
 438                                 }
 439                                 free(table[i]);
 440                         }
 441                         free(table);
 442                 }
 443                 v = (Values *) Values_New(); /* New reference. */
 444                 sstrncpy(v->data.host, value_list->host, sizeof(v->data.host));
 445                 sstrncpy(v->data.type, value_list->type, sizeof(v->data.type));
 446                 sstrncpy(v->data.type_instance, value_list->type_instance, sizeof(v->data.type_instance));
 447                 sstrncpy(v->data.plugin, value_list->plugin, sizeof(v->data.plugin));
 448                 sstrncpy(v->data.plugin_instance, value_list->plugin_instance, sizeof(v->data.plugin_instance));
 449                 v->data.time = CDTIME_T_TO_DOUBLE(value_list->time);
 450                 v->interval = CDTIME_T_TO_DOUBLE(value_list->interval);
 451                 Py_CLEAR(v->values);
 452                 v->values = list;
 453                 Py_CLEAR(v->meta);
 454                 v->meta = dict;  /* Steals a reference. */
 455                 ret = PyObject_CallFunctionObjArgs(c->callback, v, c->data, (void *) 0); /* New reference. */
 456                 Py_XDECREF(v);
 457                 if (ret == NULL) {
 458                         cpy_log_exception("write callback");
 459                 } else {
 460                         Py_DECREF(ret);
 461                 }
 462         CPY_RELEASE_THREADS
 463         return 0;
 464 }
 465
 466 static int cpy_notification_callback(const notification_t *notification, user_data_t *data) {
 467         cpy_callback_t *c = data->data;
 468         PyObject *ret, *notify;
 469         Notification *n;
 470
 471         CPY_LOCK_THREADS
 472                 notify = Notification_New(); /* New reference. */
 473                 n = (Notification *) notify;
 474                 sstrncpy(n->data.host, notification->host, sizeof(n->data.host));
 475                 sstrncpy(n->data.type, notification->type, sizeof(n->data.type));
 476                 sstrncpy(n->data.type_instance, notification->type_instance, sizeof(n->data.type_instance));
 477                 sstrncpy(n->data.plugin, notification->plugin, sizeof(n->data.plugin));
 478                 sstrncpy(n->data.plugin_instance, notification->plugin_instance, sizeof(n->data.plugin_instance));
 479                 n->data.time = CDTIME_T_TO_DOUBLE(notification->time);
 480                 sstrncpy(n->message, notification->message, sizeof(n->message));
 481                 n->severity = notification->severity;
 482                 ret = PyObject_CallFunctionObjArgs(c->callback, n, c->data, (void *) 0); /* New reference. */
 483                 Py_XDECREF(notify);
 484                 if (ret == NULL) {
 485                         cpy_log_exception("notification callback");
 486                 } else {
 487                         Py_DECREF(ret);
 488                 }
 489         CPY_RELEASE_THREADS
 490         return 0;
 491 }
 492
 493 static void cpy_log_callback(int severity, const char *message, user_data_t *data) {
 494         cpy_callback_t * c = data->data;
 495         PyObject *ret, *text;
 496
 497         CPY_LOCK_THREADS
 498         text = cpy_string_to_unicode_or_bytes(message);  /* New reference. */
 499         if (c->data == NULL)
 500                 ret = PyObject_CallFunction(c->callback, "iN", severity, text); /* New reference. Steals a reference from "text". */
 501         else
 502                 ret = PyObject_CallFunction(c->callback, "iNO", severity, text, c->data); /* New reference. Steals a reference from "text". */
 503
 504         if (ret == NULL) {
 505                 /* FIXME */
 506                 /* Do we really want to trigger a log callback because a log callback failed?
 507                  * Probably not. */
 508                 PyErr_Print();
 509                 /* In case someone wanted to be clever, replaced stderr and failed at that. */
 510                 PyErr_Clear();
 511         } else {
 512                 Py_DECREF(ret);
 513         }
 514         CPY_RELEASE_THREADS
 515 }
 516
 517 static void cpy_flush_callback(int timeout, const char *id, user_data_t *data) {
 518         cpy_callback_t * c = data->data;
 519         PyObject *ret, *text;
 520
 521         CPY_LOCK_THREADS
 522         text = cpy_string_to_unicode_or_bytes(id);
 523         if (c->data == NULL)
 524                 ret = PyObject_CallFunction(c->callback, "iN", timeout, text); /* New reference. */
 525         else
 526                 ret = PyObject_CallFunction(c->callback, "iNO", timeout, text, c->data); /* New reference. */
 527
 528         if (ret == NULL) {
 529                 cpy_log_exception("flush callback");
 530         } else {
 531                 Py_DECREF(ret);
 532         }
 533         CPY_RELEASE_THREADS
 534 }
 535
 536 static PyObject *cpy_register_generic(cpy_callback_t **list_head, PyObject *args, PyObject *kwds) {
 537         char buf[512];
 538         cpy_callback_t *c;
 539         char *name = NULL;
 540         PyObject *callback = NULL, *data = NULL, *mod = NULL;
 541         static char *kwlist[] = {"callback", "data", "name", NULL};
 542
 543         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|Oet", kwlist, &callback, &data, NULL, &name) == 0) return NULL;
 544         if (PyCallable_Check(callback) == 0) {
 545                 PyMem_Free(name);
 546                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 547                 return NULL;
 548         }
 549         cpy_build_name(buf, sizeof(buf), callback, name);
 550
 551         Py_INCREF(callback);
 552         Py_XINCREF(data);
 553
 554         c = calloc(1, sizeof(*c));
 555         if (c == NULL)
 556                 return NULL;
 557
 558         c->name = strdup(buf);
 559         c->callback = callback;
 560         c->data = data;
 561         c->next = *list_head;
 562         *list_head = c;
 563         Py_XDECREF(mod);
 564         PyMem_Free(name);
 565         return cpy_string_to_unicode_or_bytes(buf);
 566 }
 567
 568 static PyObject *float_or_none(float number) {
 569         if (isnan(number)) {
 570                 Py_RETURN_NONE;
 571         }
 572         return PyFloat_FromDouble(number);
 573 }
 574
 575 static PyObject *cpy_get_dataset(PyObject *self, PyObject *args) {
 576         char *name;
 577         const data_set_t *ds;
 578         PyObject *list, *tuple;
 579
 580         if (PyArg_ParseTuple(args, "et", NULL, &name) == 0) return NULL;
 581         ds = plugin_get_ds(name);
 582         PyMem_Free(name);
 583         if (ds == NULL) {
 584                 PyErr_Format(PyExc_TypeError, "Dataset %s not found", name);
 585                 return NULL;
 586         }
 587         list = PyList_New(ds->ds_num); /* New reference. */
 588         for (size_t i = 0; i < ds->ds_num; ++i) {
 589                 tuple = PyTuple_New(4);
 590                 PyTuple_SET_ITEM(tuple, 0, cpy_string_to_unicode_or_bytes(ds->ds[i].name));
 591                 PyTuple_SET_ITEM(tuple, 1, cpy_string_to_unicode_or_bytes(DS_TYPE_TO_STRING(ds->ds[i].type)));
 592                 PyTuple_SET_ITEM(tuple, 2, float_or_none(ds->ds[i].min));
 593                 PyTuple_SET_ITEM(tuple, 3, float_or_none(ds->ds[i].max));
 594                 PyList_SET_ITEM(list, i, tuple);
 595         }
 596         return list;
 597 }
 598
 599 static PyObject *cpy_flush(PyObject *self, PyObject *args, PyObject *kwds) {
 600         int timeout = -1;
 601         char *plugin = NULL, *identifier = NULL;
 602         static char *kwlist[] = {"plugin", "timeout", "identifier", NULL};
 603
 604         if (PyArg_ParseTupleAndKeywords(args, kwds, "|etiet", kwlist, NULL, &plugin, &timeout, NULL, &identifier) == 0) return NULL;
 605         Py_BEGIN_ALLOW_THREADS
 606         plugin_flush(plugin, timeout, identifier);
 607         Py_END_ALLOW_THREADS
 608         PyMem_Free(plugin);
 609         PyMem_Free(identifier);
 610         Py_RETURN_NONE;
 611 }
 612
 613 static PyObject *cpy_register_config(PyObject *self, PyObject *args, PyObject *kwds) {
 614         return cpy_register_generic(&cpy_config_callbacks, args, kwds);
 615 }
 616
 617 static PyObject *cpy_register_init(PyObject *self, PyObject *args, PyObject *kwds) {
 618         return cpy_register_generic(&cpy_init_callbacks, args, kwds);
 619 }
 620
 621 typedef int reg_function_t(const char *name, void *callback, void *data);
 622
 623 static PyObject *cpy_register_generic_userdata(void *reg, void *handler, PyObject *args, PyObject *kwds) {
 624         char buf[512];
 625         reg_function_t *register_function = (reg_function_t *) reg;
 626         cpy_callback_t *c = NULL;
 627         user_data_t user_data = { 0 };
 628         char *name = NULL;
 629         PyObject *callback = NULL, *data = NULL;
 630         static char *kwlist[] = {"callback", "data", "name", NULL};
 631
 632         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|Oet", kwlist, &callback, &data, NULL, &name) == 0) return NULL;
 633         if (PyCallable_Check(callback) == 0) {
 634                 PyMem_Free(name);
 635                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 636                 return NULL;
 637         }
 638         cpy_build_name(buf, sizeof(buf), callback, name);
 639         PyMem_Free(name);
 640
 641         Py_INCREF(callback);
 642         Py_XINCREF(data);
 643
 644         c = calloc(1, sizeof(*c));
 645         if (c == NULL)
 646                 return NULL;
 647
 648         c->name = strdup(buf);
 649         c->callback = callback;
 650         c->data = data;
 651         c->next = NULL;
 652
 653         user_data.free_func = cpy_destroy_user_data;
 654         user_data.data = c;
 655
 656         register_function(buf, handler, &user_data);
 657         return cpy_string_to_unicode_or_bytes(buf);
 658 }
 659
 660 static PyObject *cpy_register_read(PyObject *self, PyObject *args, PyObject *kwds) {
 661         char buf[512];
 662         cpy_callback_t *c = NULL;
 663         user_data_t user_data = { 0 };
 664         double interval = 0;
 665         char *name = NULL;
 666         PyObject *callback = NULL, *data = NULL;
 667         static char *kwlist[] = {"callback", "interval", "data", "name", NULL};
 668
 669         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|dOet", kwlist, &callback, &interval, &data, NULL, &name) == 0) return NULL;
 670         if (PyCallable_Check(callback) == 0) {
 671                 PyMem_Free(name);
 672                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 673                 return NULL;
 674         }
 675         cpy_build_name(buf, sizeof(buf), callback, name);
 676         PyMem_Free(name);
 677
 678         Py_INCREF(callback);
 679         Py_XINCREF(data);
 680
 681         c = calloc(1, sizeof(*c));
 682         if (c == NULL)
 683                 return NULL;
 684
 685         c->name = strdup(buf);
 686         c->callback = callback;
 687         c->data = data;
 688         c->next = NULL;
 689
 690         user_data.free_func = cpy_destroy_user_data;
 691         user_data.data = c;
 692
 693         plugin_register_complex_read(/* group = */ "python", buf,
 694                         cpy_read_callback, DOUBLE_TO_CDTIME_T (interval), &user_data);
 695         return cpy_string_to_unicode_or_bytes(buf);
 696 }
 697
 698 static PyObject *cpy_register_log(PyObject *self, PyObject *args, PyObject *kwds) {
 699         return cpy_register_generic_userdata((void *) plugin_register_log,
 700                         (void *) cpy_log_callback, args, kwds);
 701 }
 702
 703 static PyObject *cpy_register_write(PyObject *self, PyObject *args, PyObject *kwds) {
 704         return cpy_register_generic_userdata((void *) plugin_register_write,
 705                         (void *) cpy_write_callback, args, kwds);
 706 }
 707
 708 static PyObject *cpy_register_notification(PyObject *self, PyObject *args, PyObject *kwds) {
 709         return cpy_register_generic_userdata((void *) plugin_register_notification,
 710                         (void *) cpy_notification_callback, args, kwds);
 711 }
 712
 713 static PyObject *cpy_register_flush(PyObject *self, PyObject *args, PyObject *kwds) {
 714         return cpy_register_generic_userdata((void *) plugin_register_flush,
 715                         (void *) cpy_flush_callback, args, kwds);
 716 }
 717
 718 static PyObject *cpy_register_shutdown(PyObject *self, PyObject *args, PyObject *kwds) {
 719         return cpy_register_generic(&cpy_shutdown_callbacks, args, kwds);
 720 }
 721
 722 static PyObject *cpy_error(PyObject *self, PyObject *args) {
 723         char *text;
 724         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 725         Py_BEGIN_ALLOW_THREADS
 726         plugin_log(LOG_ERR, "%s", text);
 727         Py_END_ALLOW_THREADS
 728         PyMem_Free(text);
 729         Py_RETURN_NONE;
 730 }
 731
 732 static PyObject *cpy_warning(PyObject *self, PyObject *args) {
 733         char *text;
 734         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 735         Py_BEGIN_ALLOW_THREADS
 736         plugin_log(LOG_WARNING, "%s", text);
 737         Py_END_ALLOW_THREADS
 738         PyMem_Free(text);
 739         Py_RETURN_NONE;
 740 }
 741
 742 static PyObject *cpy_notice(PyObject *self, PyObject *args) {
 743         char *text;
 744         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 745         Py_BEGIN_ALLOW_THREADS
 746         plugin_log(LOG_NOTICE, "%s", text);
 747         Py_END_ALLOW_THREADS
 748         PyMem_Free(text);
 749         Py_RETURN_NONE;
 750 }
 751
 752 static PyObject *cpy_info(PyObject *self, PyObject *args) {
 753         char *text;
 754         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 755         Py_BEGIN_ALLOW_THREADS
 756         plugin_log(LOG_INFO, "%s", text);
 757         Py_END_ALLOW_THREADS
 758         PyMem_Free(text);
 759         Py_RETURN_NONE;
 760 }
 761
 762 static PyObject *cpy_debug(PyObject *self, PyObject *args) {
 763 #ifdef COLLECT_DEBUG
 764         char *text;
 765         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 766         Py_BEGIN_ALLOW_THREADS
 767         plugin_log(LOG_DEBUG, "%s", text);
 768         Py_END_ALLOW_THREADS
 769         PyMem_Free(text);
 770 #endif
 771         Py_RETURN_NONE;
 772 }
 773
 774 static PyObject *cpy_unregister_generic(cpy_callback_t **list_head, PyObject *arg, const char *desc) {
 775         char buf[512];
 776         const char *name;
 777         cpy_callback_t *prev = NULL, *tmp;
 778
 779         Py_INCREF(arg);
 780         name = cpy_unicode_or_bytes_to_string(&arg);
 781         if (name == NULL) {
 782                 PyErr_Clear();
 783                 if (!PyCallable_Check(arg)) {
 784                         PyErr_SetString(PyExc_TypeError, "This function needs a string or a callable object as its only parameter.");
 785                         Py_DECREF(arg);
 786                         return NULL;
 787                 }
 788                 cpy_build_name(buf, sizeof(buf), arg, NULL);
 789                 name = buf;
 790         }
 791         for (tmp = *list_head; tmp; prev = tmp, tmp = tmp->next)
 792                 if (strcmp(name, tmp->name) == 0)
 793                         break;
 794
 795         Py_DECREF(arg);
 796         if (tmp == NULL) {
 797                 PyErr_Format(PyExc_RuntimeError, "Unable to unregister %s callback '%s'.", desc, name);
 798                 return NULL;
 799         }
 800         /* Yes, this is actually save. To call this function the caller has to
 801          * hold the GIL. Well, save as long as there is only one GIL anyway ... */
 802         if (prev == NULL)
 803                 *list_head = tmp->next;
 804         else
 805                 prev->next = tmp->next;
 806         cpy_destroy_user_data(tmp);
 807         Py_RETURN_NONE;
 808 }
 809
 810 typedef int cpy_unregister_function_t(const char *name);
 811
 812 static PyObject *cpy_unregister_generic_userdata(cpy_unregister_function_t *unreg, PyObject *arg, const char *desc) {
 813         char buf[512];
 814         const char *name;
 815
 816         Py_INCREF(arg);
 817         name = cpy_unicode_or_bytes_to_string(&arg);
 818         if (name == NULL) {
 819                 PyErr_Clear();
 820                 if (!PyCallable_Check(arg)) {
 821                         PyErr_SetString(PyExc_TypeError, "This function needs a string or a callable object as its only parameter.");
 822                         Py_DECREF(arg);
 823                         return NULL;
 824                 }
 825                 cpy_build_name(buf, sizeof(buf), arg, NULL);
 826                 name = buf;
 827         }
 828         if (unreg(name) == 0) {
 829                 Py_DECREF(arg);
 830                 Py_RETURN_NONE;
 831         }
 832         PyErr_Format(PyExc_RuntimeError, "Unable to unregister %s callback '%s'.", desc, name);
 833         Py_DECREF(arg);
 834         return NULL;
 835 }
 836
 837 static PyObject *cpy_unregister_log(PyObject *self, PyObject *arg) {
 838         return cpy_unregister_generic_userdata(plugin_unregister_log, arg, "log");
 839 }
 840
 841 static PyObject *cpy_unregister_init(PyObject *self, PyObject *arg) {
 842         return cpy_unregister_generic(&cpy_init_callbacks, arg, "init");
 843 }
 844
 845 static PyObject *cpy_unregister_config(PyObject *self, PyObject *arg) {
 846         return cpy_unregister_generic(&cpy_config_callbacks, arg, "config");
 847 }
 848
 849 static PyObject *cpy_unregister_read(PyObject *self, PyObject *arg) {
 850         return cpy_unregister_generic_userdata(plugin_unregister_read, arg, "read");
 851 }
 852
 853 static PyObject *cpy_unregister_write(PyObject *self, PyObject *arg) {
 854         return cpy_unregister_generic_userdata(plugin_unregister_write, arg, "write");
 855 }
 856
 857 static PyObject *cpy_unregister_notification(PyObject *self, PyObject *arg) {
 858         return cpy_unregister_generic_userdata(plugin_unregister_notification, arg, "notification");
 859 }
 860
 861 static PyObject *cpy_unregister_flush(PyObject *self, PyObject *arg) {
 862         return cpy_unregister_generic_userdata(plugin_unregister_flush, arg, "flush");
 863 }
 864
 865 static PyObject *cpy_unregister_shutdown(PyObject *self, PyObject *arg) {
 866         return cpy_unregister_generic(&cpy_shutdown_callbacks, arg, "shutdown");
 867 }
 868
 869 static PyMethodDef cpy_methods[] = {
 870         {"debug", cpy_debug, METH_VARARGS, log_doc},
 871         {"info", cpy_info, METH_VARARGS, log_doc},
 872         {"notice", cpy_notice, METH_VARARGS, log_doc},
 873         {"warning", cpy_warning, METH_VARARGS, log_doc},
 874         {"error", cpy_error, METH_VARARGS, log_doc},
 875         {"get_dataset", (PyCFunction) cpy_get_dataset, METH_VARARGS, get_ds_doc},
 876         {"flush", (PyCFunction) cpy_flush, METH_VARARGS | METH_KEYWORDS, flush_doc},
 877         {"register_log", (PyCFunction) cpy_register_log, METH_VARARGS | METH_KEYWORDS, reg_log_doc},
 878         {"register_init", (PyCFunction) cpy_register_init, METH_VARARGS | METH_KEYWORDS, reg_init_doc},
 879         {"register_config", (PyCFunction) cpy_register_config, METH_VARARGS | METH_KEYWORDS, reg_config_doc},
 880         {"register_read", (PyCFunction) cpy_register_read, METH_VARARGS | METH_KEYWORDS, reg_read_doc},
 881         {"register_write", (PyCFunction) cpy_register_write, METH_VARARGS | METH_KEYWORDS, reg_write_doc},
 882         {"register_notification", (PyCFunction) cpy_register_notification, METH_VARARGS | METH_KEYWORDS, reg_notification_doc},
 883         {"register_flush", (PyCFunction) cpy_register_flush, METH_VARARGS | METH_KEYWORDS, reg_flush_doc},
 884         {"register_shutdown", (PyCFunction) cpy_register_shutdown, METH_VARARGS | METH_KEYWORDS, reg_shutdown_doc},
 885         {"unregister_log", cpy_unregister_log, METH_O, unregister_doc},
 886         {"unregister_init", cpy_unregister_init, METH_O, unregister_doc},
 887         {"unregister_config", cpy_unregister_config, METH_O, unregister_doc},
 888         {"unregister_read", cpy_unregister_read, METH_O, unregister_doc},
 889         {"unregister_write", cpy_unregister_write, METH_O, unregister_doc},
 890         {"unregister_notification", cpy_unregister_notification, METH_O, unregister_doc},
 891         {"unregister_flush", cpy_unregister_flush, METH_O, unregister_doc},
 892         {"unregister_shutdown", cpy_unregister_shutdown, METH_O, unregister_doc},
 893         {0, 0, 0, 0}
 894 };
 895
 896 static int cpy_shutdown(void) {
 897         PyObject *ret;
 898
 899         /* This can happen if the module was loaded but not configured. */
 900         if (state != NULL)
 901                 PyEval_RestoreThread(state);
 902
 903         for (cpy_callback_t *c = cpy_shutdown_callbacks; c; c = c->next) {
 904                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 905                 if (ret == NULL)
 906                         cpy_log_exception("shutdown callback");
 907                 else
 908                         Py_DECREF(ret);
 909         }
 910         PyErr_Print();
 911         Py_Finalize();
 912         return 0;
 913 }
 914
 915 static void *cpy_interactive(void *data) {
 916         PyOS_sighandler_t cur_sig;
 917
 918         /* Signal handler in a plugin? Bad stuff, but the best way to
 919          * handle it I guess. In an interactive session people will
 920          * press Ctrl+C at some time, which will generate a SIGINT.
 921          * This will cause collectd to shutdown, thus killing the
 922          * interactive interpreter, and leaving the terminal in a
 923          * mess. Chances are, this isn't what the user wanted to do.
 924          *
 925          * So this is the plan:
 926          * 1. Restore Python's own signal handler
 927          * 2. Tell Python we just forked so it will accept this thread
 928          *    as the main one. No version of Python will ever handle
 929          *    interrupts anywhere but in the main thread.
 930          * 3. After the interactive loop is done, restore collectd's
 931          *    SIGINT handler.
 932          * 4. Raise SIGINT for a clean shutdown. The signal is sent to
 933          *    the main thread to ensure it wakes up the main interval
 934          *    sleep so that collectd shuts down immediately not in 10
 935          *    seconds.
 936          *
 937          * This will make sure that SIGINT won't kill collectd but
 938          * still interrupt syscalls like sleep and pause. */
 939
 940         PyEval_AcquireThread(state);
 941         if (PyImport_ImportModule("readline") == NULL) {
 942                 /* This interactive session will suck. */
 943                 cpy_log_exception("interactive session init");
 944         }
 945         cur_sig = PyOS_setsig(SIGINT, python_sigint_handler);
 946         /* We totally forked just now. Everyone saw that, right? */
 947         PyOS_AfterFork();
 948         PyRun_InteractiveLoop(stdin, "<stdin>");
 949         PyOS_setsig(SIGINT, cur_sig);
 950         PyErr_Print();
 951         PyEval_ReleaseThread(state);
 952         NOTICE("python: Interactive interpreter exited, stopping collectd ...");
 953         pthread_kill(main_thread, SIGINT);
 954         return NULL;
 955 }
 956
 957 static int cpy_init(void) {
 958         PyObject *ret;
 959         static pthread_t thread;
 960
 961         if (!Py_IsInitialized()) {
 962                 WARNING("python: Plugin loaded but not configured.");
 963                 plugin_unregister_shutdown("python");
 964                 return 0;
 965         }
 966         PyEval_InitThreads();
 967         /* Now it's finally OK to use python threads. */
 968         for (cpy_callback_t *c = cpy_init_callbacks; c; c = c->next) {
 969                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 970                 if (ret == NULL)
 971                         cpy_log_exception("init callback");
 972                 else
 973                         Py_DECREF(ret);
 974         }
 975         state = PyEval_SaveThread();
 976         main_thread = pthread_self();
 977         if (do_interactive) {
 978                 if (plugin_thread_create(&thread, NULL, cpy_interactive, NULL)) {
 979                         ERROR("python: Error creating thread for interactive interpreter.");
 980                 }
 981         }
 982
 983         return 0;
 984 }
 985
 986 static PyObject *cpy_oconfig_to_pyconfig(oconfig_item_t *ci, PyObject *parent) {
 987         PyObject *item, *values, *children, *tmp;
 988
 989         if (parent == NULL)
 990                 parent = Py_None;
 991
 992         values = PyTuple_New(ci->values_num); /* New reference. */
 993         for (int i = 0; i < ci->values_num; ++i) {
 994                 if (ci->values[i].type == OCONFIG_TYPE_STRING) {
 995                         PyTuple_SET_ITEM(values, i, cpy_string_to_unicode_or_bytes(ci->values[i].value.string));
 996                 } else if (ci->values[i].type == OCONFIG_TYPE_NUMBER) {
 997                         PyTuple_SET_ITEM(values, i, PyFloat_FromDouble(ci->values[i].value.number));
 998                 } else if (ci->values[i].type == OCONFIG_TYPE_BOOLEAN) {
 999                         PyTuple_SET_ITEM(values, i, PyBool_FromLong(ci->values[i].value.boolean));
1000                 }
1001         }
1002
1003         tmp = cpy_string_to_unicode_or_bytes(ci->key);
1004         item = PyObject_CallFunction((void *) &ConfigType, "NONO", tmp, parent, values, Py_None);
1005         if (item == NULL)
1006                 return NULL;
1007         children = PyTuple_New(ci->children_num); /* New reference. */
1008         for (int i = 0; i < ci->children_num; ++i) {
1009                 PyTuple_SET_ITEM(children, i, cpy_oconfig_to_pyconfig(ci->children + i, item));
1010         }
1011         tmp = ((Config *) item)->children;
1012         ((Config *) item)->children = children;
1013         Py_XDECREF(tmp);
1014         return item;
1015 }
1016
1017 #ifdef IS_PY3K
1018 static struct PyModuleDef collectdmodule = {
1019         PyModuleDef_HEAD_INIT,
1020         "collectd",   /* name of module */
1021         "The python interface to collectd", /* module documentation, may be NULL */
1022         -1,
1023         cpy_methods
1024 };
1025
1026 PyMODINIT_FUNC PyInit_collectd(void) {
1027         return PyModule_Create(&collectdmodule);
1028 }
1029 #endif
1030
1031 static int cpy_init_python(void) {
1032         PyOS_sighandler_t cur_sig;
1033         PyObject *sys;
1034         PyObject *module;
1035
1036 #ifdef IS_PY3K
1037         wchar_t *argv = L"";
1038         /* Add a builtin module, before Py_Initialize */
1039         PyImport_AppendInittab("collectd", PyInit_collectd);
1040 #else
1041         char *argv = "";
1042 #endif
1043
1044         /* Chances are the current signal handler is already SIG_DFL, but let's make sure. */
1045         cur_sig = PyOS_setsig(SIGINT, SIG_DFL);
1046         Py_Initialize();
1047         python_sigint_handler = PyOS_setsig(SIGINT, cur_sig);
1048
1049         PyType_Ready(&ConfigType);
1050         PyType_Ready(&PluginDataType);
1051         ValuesType.tp_base = &PluginDataType;
1052         PyType_Ready(&ValuesType);
1053         NotificationType.tp_base = &PluginDataType;
1054         PyType_Ready(&NotificationType);
1055         SignedType.tp_base = &PyLong_Type;
1056         PyType_Ready(&SignedType);
1057         UnsignedType.tp_base = &PyLong_Type;
1058         PyType_Ready(&UnsignedType);
1059         sys = PyImport_ImportModule("sys"); /* New reference. */
1060         if (sys == NULL) {
1061                 cpy_log_exception("python initialization");
1062                 return 1;
1063         }
1064         sys_path = PyObject_GetAttrString(sys, "path"); /* New reference. */
1065         Py_DECREF(sys);
1066         if (sys_path == NULL) {
1067                 cpy_log_exception("python initialization");
1068                 return 1;
1069         }
1070         PySys_SetArgv(1, &argv);
1071         PyList_SetSlice(sys_path, 0, 1, NULL);
1072
1073 #ifdef IS_PY3K
1074         module = PyImport_ImportModule("collectd");
1075 #else
1076         module = Py_InitModule("collectd", cpy_methods); /* Borrowed reference. */
1077 #endif
1078         PyModule_AddObject(module, "Config", (void *) &ConfigType); /* Steals a reference. */
1079         PyModule_AddObject(module, "Values", (void *) &ValuesType); /* Steals a reference. */
1080         PyModule_AddObject(module, "Notification", (void *) &NotificationType); /* Steals a reference. */
1081         PyModule_AddObject(module, "Signed", (void *) &SignedType); /* Steals a reference. */
1082         PyModule_AddObject(module, "Unsigned", (void *) &UnsignedType); /* Steals a reference. */
1083         PyModule_AddIntConstant(module, "LOG_DEBUG", LOG_DEBUG);
1084         PyModule_AddIntConstant(module, "LOG_INFO", LOG_INFO);
1085         PyModule_AddIntConstant(module, "LOG_NOTICE", LOG_NOTICE);
1086         PyModule_AddIntConstant(module, "LOG_WARNING", LOG_WARNING);
1087         PyModule_AddIntConstant(module, "LOG_ERROR", LOG_ERR);
1088         PyModule_AddIntConstant(module, "NOTIF_FAILURE", NOTIF_FAILURE);
1089         PyModule_AddIntConstant(module, "NOTIF_WARNING", NOTIF_WARNING);
1090         PyModule_AddIntConstant(module, "NOTIF_OKAY", NOTIF_OKAY);
1091         PyModule_AddStringConstant(module, "DS_TYPE_COUNTER", DS_TYPE_TO_STRING(DS_TYPE_COUNTER));
1092         PyModule_AddStringConstant(module, "DS_TYPE_GAUGE", DS_TYPE_TO_STRING(DS_TYPE_GAUGE));
1093         PyModule_AddStringConstant(module, "DS_TYPE_DERIVE", DS_TYPE_TO_STRING(DS_TYPE_DERIVE));
1094         PyModule_AddStringConstant(module, "DS_TYPE_ABSOLUTE", DS_TYPE_TO_STRING(DS_TYPE_ABSOLUTE));
1095         return 0;
1096 }
1097
1098 static int cpy_config(oconfig_item_t *ci) {
1099         PyObject *tb;
1100         int status = 0;
1101
1102         /* Ok in theory we shouldn't do initialization at this point
1103          * but we have to. In order to give python scripts a chance
1104          * to register a config callback we need to be able to execute
1105          * python code during the config callback so we have to start
1106          * the interpreter here. */
1107         /* Do *not* use the python "thread" module at this point! */
1108
1109         if (!Py_IsInitialized() && cpy_init_python()) return 1;
1110
1111         for (int i = 0; i < ci->children_num; ++i) {
1112                 oconfig_item_t *item = ci->children + i;
1113
1114                 if (strcasecmp(item->key, "Interactive") == 0) {
1115                         if (cf_util_get_boolean(item, &do_interactive) != 0) {
1116                                 status = 1;
1117                                 continue;
1118                         }
1119                 } else if (strcasecmp(item->key, "Encoding") == 0) {
1120                         char *encoding = NULL;
1121                         if (cf_util_get_string(item, &encoding) != 0) {
1122                                 status = 1;
1123                                 continue;
1124                         }
1125 #ifdef IS_PY3K
1126                         ERROR("python: \"Encoding\" was used in the config file but Python3 was used, which does not support changing encodings");
1127                         status = 1;
1128                         sfree(encoding);
1129                         continue;
1130 #else
1131                         /* Why is this even necessary? And undocumented? */
1132                         if (PyUnicode_SetDefaultEncoding(encoding)) {
1133                                 cpy_log_exception("setting default encoding");
1134                                 status = 1;
1135                         }
1136 #endif
1137                         sfree(encoding);
1138                 } else if (strcasecmp(item->key, "LogTraces") == 0) {
1139                         _Bool log_traces;
1140                         if (cf_util_get_boolean(item, &log_traces) != 0) {
1141                                 status = 1;
1142                                 continue;
1143                         }
1144                         if (!log_traces) {
1145                                 Py_XDECREF(cpy_format_exception);
1146                                 cpy_format_exception = NULL;
1147                                 continue;
1148                         }
1149                         if (cpy_format_exception)
1150                                 continue;
1151                         tb = PyImport_ImportModule("traceback"); /* New reference. */
1152                         if (tb == NULL) {
1153                                 cpy_log_exception("python initialization");
1154                                 status = 1;
1155                                 continue;
1156                         }
1157                         cpy_format_exception = PyObject_GetAttrString(tb, "format_exception"); /* New reference. */
1158                         Py_DECREF(tb);
1159                         if (cpy_format_exception == NULL) {
1160                                 cpy_log_exception("python initialization");
1161                                 status = 1;
1162                         }
1163                 } else if (strcasecmp(item->key, "ModulePath") == 0) {
1164                         char *dir = NULL;
1165                         PyObject *dir_object;
1166
1167                         if (cf_util_get_string(item, &dir) != 0) {
1168                                 status = 1;
1169                                 continue;
1170                         }
1171                         dir_object = cpy_string_to_unicode_or_bytes(dir); /* New reference. */
1172                         if (dir_object == NULL) {
1173                                 ERROR("python plugin: Unable to convert \"%s\" to "
1174                                       "a python object.", dir);
1175                                 free(dir);
1176                                 cpy_log_exception("python initialization");
1177                                 status = 1;
1178                                 continue;
1179                         }
1180                         if (PyList_Insert(sys_path, 0, dir_object) != 0) {
1181                                 ERROR("python plugin: Unable to prepend \"%s\" to "
1182                                       "python module path.", dir);
1183                                 cpy_log_exception("python initialization");
1184                                 status = 1;
1185                         }
1186                         Py_DECREF(dir_object);
1187                         free(dir);
1188                 } else if (strcasecmp(item->key, "Import") == 0) {
1189                         char *module_name = NULL;
1190                         PyObject *module;
1191
1192                         if (cf_util_get_string(item, &module_name) != 0) {
1193                                 status = 1;
1194                                 continue;
1195                         }
1196                         module = PyImport_ImportModule(module_name); /* New reference. */
1197                         if (module == NULL) {
1198                                 ERROR("python plugin: Error importing module \"%s\".", module_name);
1199                                 cpy_log_exception("importing module");
1200                                 status = 1;
1201                         }
1202                         free(module_name);
1203                         Py_XDECREF(module);
1204                 } else if (strcasecmp(item->key, "Module") == 0) {
1205                         char *name = NULL;
1206                         cpy_callback_t *c;
1207                         PyObject *ret;
1208
1209                         if (cf_util_get_string(item, &name) != 0) {
1210                                 status = 1;
1211                                 continue;
1212                         }
1213                         for (c = cpy_config_callbacks; c; c = c->next) {
1214                                 if (strcasecmp(c->name + 7, name) == 0)
1215                                         break;
1216                         }
1217                         if (c == NULL) {
1218                                 WARNING("python plugin: Found a configuration for the \"%s\" plugin, "
1219                                         "but the plugin isn't loaded or didn't register "
1220                                         "a configuration callback.", name);
1221                                 free(name);
1222                                 continue;
1223                         }
1224                         free(name);
1225                         if (c->data == NULL)
1226                                 ret = PyObject_CallFunction(c->callback, "N",
1227                                         cpy_oconfig_to_pyconfig(item, NULL)); /* New reference. */
1228                         else
1229                                 ret = PyObject_CallFunction(c->callback, "NO",
1230                                         cpy_oconfig_to_pyconfig(item, NULL), c->data); /* New reference. */
1231                         if (ret == NULL) {
1232                                 cpy_log_exception("loading module");
1233                                 status = 1;
1234                         } else
1235                                 Py_DECREF(ret);
1236                 } else {
1237                         ERROR("python plugin: Unknown config key \"%s\".", item->key);
1238                         status = 1;
1239                 }
1240         }
1241         return (status);
1242 }
1243
1244 void module_register(void) {
1245         plugin_register_complex_config("python", cpy_config);
1246         plugin_register_init("python", cpy_init);
1247         plugin_register_shutdown("python", cpy_shutdown);
1248 }