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 #if HAVE_PTHREAD_H
  32 # include <pthread.h>
  33 #endif
  34
  35 #include "collectd.h"
  36 #include "common.h"
  37
  38 #include "cpython.h"
  39
  40 typedef struct cpy_callback_s {
  41         char *name;
  42         PyObject *callback;
  43         PyObject *data;
  44         struct cpy_callback_s *next;
  45 } cpy_callback_t;
  46
  47 static char log_doc[] = "This function sends a string to all logging plugins.";
  48
  49 static char get_ds_doc[] = "get_dataset(name) -> definition\n"
  50                 "\n"
  51                 "Returns the definition of a dataset specified by name.\n"
  52                 "\n"
  53                 "'name' is a string specifying the dataset to query.\n"
  54                 "'definition' is a list of 4-tuples. Every tuple represents a \n"
  55                 "    data source within the data set and its 4 values are the \n"
  56                 "    name, type, min and max value.\n"
  57                 "    'name' is a string.\n"
  58                 "    'type' is a string that is equal to either DS_TYPE_COUNTER,\n"
  59                 "        DS_TYPE_GAUGE, DS_TYPE_DERIVE or DS_TYPE_ABSOLUTE.\n"
  60                 "    'min' and 'max' are either a float or None.";
  61
  62 static char flush_doc[] = "flush([plugin][, timeout][, identifier]) -> None\n"
  63                 "\n"
  64                 "Flushes the cache of another plugin.";
  65
  66 static char unregister_doc[] = "Unregisters a callback. This function needs exactly one parameter either\n"
  67                 "the function to unregister or the callback identifier to unregister.";
  68
  69 static char reg_log_doc[] = "register_log(callback[, data][, name]) -> identifier\n"
  70                 "\n"
  71                 "Register a callback function for log messages.\n"
  72                 "\n"
  73                 "'callback' is a callable object that will be called every time something\n"
  74                 "    is logged.\n"
  75                 "'data' is an optional object that will be passed back to the callback\n"
  76                 "    function every time it is called.\n"
  77                 "'name' is an optional identifier for this callback. The default name\n"
  78                 "    is 'python.<module>'.\n"
  79                 "    Every callback needs a unique identifier, so if you want to\n"
  80                 "    register this callback multiple time from the same module you need\n"
  81                 "    to specify a name here.\n"
  82                 "'identifier' is the full identifier assigned to this callback.\n"
  83                 "\n"
  84                 "The callback function will be called with two or three parameters:\n"
  85                 "severity: An integer that should be compared to the LOG_ constants.\n"
  86                 "message: The text to be logged.\n"
  87                 "data: The optional data parameter passed to the register function.\n"
  88                 "    If the parameter was omitted it will be omitted here, too.";
  89
  90 static char reg_init_doc[] = "register_init(callback[, data][, name]) -> identifier\n"
  91                 "\n"
  92                 "Register a callback function that will be executed once after the config.\n"
  93                 "file has been read, all plugins heve been loaded and the collectd has\n"
  94                 "forked into the background.\n"
  95                 "\n"
  96                 "'callback' is a callable object that will be executed.\n"
  97                 "'data' is an optional object that will be passed back to the callback\n"
  98                 "    function when it is called.\n"
  99                 "'name' is an optional identifier for this callback. The default name\n"
 100                 "    is 'python.<module>'.\n"
 101                 "    Every callback needs a unique identifier, so if you want to\n"
 102                 "    register this callback multiple time from the same module you need\n"
 103                 "    to specify a name here.\n"
 104                 "'identifier' is the full identifier assigned to this callback.\n"
 105                 "\n"
 106                 "The callback function will be called without parameters, except for\n"
 107                 "data if it was supplied.";
 108
 109 static char reg_config_doc[] = "register_config(callback[, data][, name]) -> identifier\n"
 110                 "\n"
 111                 "Register a callback function for config file entries.\n"
 112                 "'callback' is a callable object that will be called for every config block.\n"
 113                 "'data' is an optional object that will be passed back to the callback\n"
 114                 "    function every time it is called.\n"
 115                 "'name' is an optional identifier for this callback. The default name\n"
 116                 "    is 'python.<module>'.\n"
 117                 "    Every callback needs a unique identifier, so if you want to\n"
 118                 "    register this callback multiple time from the same module you need\n"
 119                 "    to specify a name here.\n"
 120                 "'identifier' is the full identifier assigned to this callback.\n"
 121                 "\n"
 122                 "The callback function will be called with one or two parameters:\n"
 123                 "config: A Config object.\n"
 124                 "data: The optional data parameter passed to the register function.\n"
 125                 "    If the parameter was omitted it will be omitted here, too.";
 126
 127 static char reg_read_doc[] = "register_read(callback[, interval][, data][, name]) -> identifier\n"
 128                 "\n"
 129                 "Register a callback function for reading data. It will just be called\n"
 130                 "in a fixed interval to signal that it's time to dispatch new values.\n"
 131                 "'callback' is a callable object that will be called every time something\n"
 132                 "    is logged.\n"
 133                 "'interval' is the number of seconds between between calls to the callback\n"
 134                 "    function. Full float precision is supported here.\n"
 135                 "'data' is an optional object that will be passed back to the callback\n"
 136                 "    function every time it is called.\n"
 137                 "'name' is an optional identifier for this callback. The default name\n"
 138                 "    is 'python.<module>'.\n"
 139                 "    Every callback needs a unique identifier, so if you want to\n"
 140                 "    register this callback multiple time from the same module you need\n"
 141                 "    to specify a name here.\n"
 142                 "'identifier' is the full identifier assigned to this callback.\n"
 143                 "\n"
 144                 "The callback function will be called without parameters, except for\n"
 145                 "data if it was supplied.";
 146
 147 static char reg_write_doc[] = "register_write(callback[, data][, name]) -> identifier\n"
 148                 "\n"
 149                 "Register a callback function to receive values dispatched by other plugins.\n"
 150                 "'callback' is a callable object that will be called every time a value\n"
 151                 "    is dispatched.\n"
 152                 "'data' is an optional object that will be passed back to the callback\n"
 153                 "    function every time it is called.\n"
 154                 "'name' is an optional identifier for this callback. The default name\n"
 155                 "    is 'python.<module>'.\n"
 156                 "    Every callback needs a unique identifier, so if you want to\n"
 157                 "    register this callback multiple time from the same module you need\n"
 158                 "    to specify a name here.\n"
 159                 "'identifier' is the full identifier assigned to this callback.\n"
 160                 "\n"
 161                 "The callback function will be called with one or two parameters:\n"
 162                 "values: A Values object which is a copy of the dispatched values.\n"
 163                 "data: The optional data parameter passed to the register function.\n"
 164                 "    If the parameter was omitted it will be omitted here, too.";
 165
 166 static char reg_notification_doc[] = "register_notification(callback[, data][, name]) -> identifier\n"
 167                 "\n"
 168                 "Register a callback function for notifications.\n"
 169                 "'callback' is a callable object that will be called every time a notification\n"
 170                 "    is dispatched.\n"
 171                 "'data' is an optional object that will be passed back to the callback\n"
 172                 "    function every time it is called.\n"
 173                 "'name' is an optional identifier for this callback. The default name\n"
 174                 "    is 'python.<module>'.\n"
 175                 "    Every callback needs a unique identifier, so if you want to\n"
 176                 "    register this callback multiple time from the same module you need\n"
 177                 "    to specify a name here.\n"
 178                 "'identifier' is the full identifier assigned to this callback.\n"
 179                 "\n"
 180                 "The callback function will be called with one or two parameters:\n"
 181                 "notification: A copy of the notification that was dispatched.\n"
 182                 "data: The optional data parameter passed to the register function.\n"
 183                 "    If the parameter was omitted it will be omitted here, too.";
 184
 185 static char reg_flush_doc[] = "register_flush(callback[, data][, name]) -> identifier\n"
 186                 "\n"
 187                 "Register a callback function for flush messages.\n"
 188                 "'callback' is a callable object that will be called every time a plugin\n"
 189                 "    requests a flush for either this or all plugins.\n"
 190                 "'data' is an optional object that will be passed back to the callback\n"
 191                 "    function every time it is called.\n"
 192                 "'name' is an optional identifier for this callback. The default name\n"
 193                 "    is 'python.<module>'.\n"
 194                 "    Every callback needs a unique identifier, so if you want to\n"
 195                 "    register this callback multiple time from the same module you need\n"
 196                 "    to specify a name here.\n"
 197                 "'identifier' is the full identifier assigned to this callback.\n"
 198                 "\n"
 199                 "The callback function will be called with two or three parameters:\n"
 200                 "timeout: Indicates that only data older than 'timeout' seconds is to\n"
 201                 "    be flushed.\n"
 202                 "id: Specifies which values are to be flushed.\n"
 203                 "data: The optional data parameter passed to the register function.\n"
 204                 "    If the parameter was omitted it will be omitted here, too.";
 205
 206 static char reg_shutdown_doc[] = "register_shutdown(callback[, data][, name]) -> identifier\n"
 207                 "\n"
 208                 "Register a callback function for collectd shutdown.\n"
 209                 "'callback' is a callable object that will be called once collectd is\n"
 210                 "    shutting down.\n"
 211                 "'data' is an optional object that will be passed back to the callback\n"
 212                 "    function if it is called.\n"
 213                 "'name' is an optional identifier for this callback. The default name\n"
 214                 "    is 'python.<module>'.\n"
 215                 "    Every callback needs a unique identifier, so if you want to\n"
 216                 "    register this callback multiple time from the same module you need\n"
 217                 "    to specify a name here.\n"
 218                 "'identifier' is the full identifier assigned to this callback.\n"
 219                 "\n"
 220                 "The callback function will be called with no parameters except for\n"
 221                 "    data if it was supplied.";
 222
 223
 224 static int 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, i;
 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         for (i = 0; i < l; ++i) {
 309                 char *s;
 310                 PyObject *line;
 311
 312                 line = PyList_GET_ITEM(list, i); /* Borrowed reference. */
 313                 Py_INCREF(line);
 314                 s = strdup(cpy_unicode_or_bytes_to_string(&line));
 315                 Py_DECREF(line);
 316                 if (s[strlen(s) - 1] == '\n')
 317                         s[strlen(s) - 1] = 0;
 318                 Py_BEGIN_ALLOW_THREADS
 319                 ERROR("%s", s);
 320                 Py_END_ALLOW_THREADS
 321                 free(s);
 322         }
 323         Py_XDECREF(list);
 324         PyErr_Clear();
 325 }
 326
 327 static int cpy_read_callback(user_data_t *data) {
 328         cpy_callback_t *c = data->data;
 329         PyObject *ret;
 330
 331         CPY_LOCK_THREADS
 332                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 333                 if (ret == NULL) {
 334                         cpy_log_exception("read callback");
 335                 } else {
 336                         Py_DECREF(ret);
 337                 }
 338         CPY_RELEASE_THREADS
 339         if (ret == NULL)
 340                 return 1;
 341         return 0;
 342 }
 343
 344 static int cpy_write_callback(const data_set_t *ds, const value_list_t *value_list, user_data_t *data) {
 345         int i;
 346         cpy_callback_t *c = data->data;
 347         PyObject *ret, *list, *temp, *dict = NULL;
 348         Values *v;
 349
 350         CPY_LOCK_THREADS
 351                 list = PyList_New(value_list->values_len); /* New reference. */
 352                 if (list == NULL) {
 353                         cpy_log_exception("write callback");
 354                         CPY_RETURN_FROM_THREADS 0;
 355                 }
 356                 for (i = 0; i < value_list->values_len; ++i) {
 357                         if (ds->ds[i].type == DS_TYPE_COUNTER) {
 358                                 if ((long) value_list->values[i].counter == value_list->values[i].counter)
 359                                         PyList_SetItem(list, i, PyInt_FromLong(value_list->values[i].counter));
 360                                 else
 361                                         PyList_SetItem(list, i, PyLong_FromUnsignedLongLong(value_list->values[i].counter));
 362                         } else if (ds->ds[i].type == DS_TYPE_GAUGE) {
 363                                 PyList_SetItem(list, i, PyFloat_FromDouble(value_list->values[i].gauge));
 364                         } else if (ds->ds[i].type == DS_TYPE_DERIVE) {
 365                                 if ((long) value_list->values[i].derive == value_list->values[i].derive)
 366                                         PyList_SetItem(list, i, PyInt_FromLong(value_list->values[i].derive));
 367                                 else
 368                                         PyList_SetItem(list, i, PyLong_FromLongLong(value_list->values[i].derive));
 369                         } else if (ds->ds[i].type == DS_TYPE_ABSOLUTE) {
 370                                 if ((long) value_list->values[i].absolute == value_list->values[i].absolute)
 371                                         PyList_SetItem(list, i, PyInt_FromLong(value_list->values[i].absolute));
 372                                 else
 373                                         PyList_SetItem(list, i, PyLong_FromUnsignedLongLong(value_list->values[i].absolute));
 374                         } else {
 375                                 Py_BEGIN_ALLOW_THREADS
 376                                 ERROR("cpy_write_callback: Unknown value type %d.", ds->ds[i].type);
 377                                 Py_END_ALLOW_THREADS
 378                                 Py_DECREF(list);
 379                                 CPY_RETURN_FROM_THREADS 0;
 380                         }
 381                         if (PyErr_Occurred() != NULL) {
 382                                 cpy_log_exception("value building for write callback");
 383                                 Py_DECREF(list);
 384                                 CPY_RETURN_FROM_THREADS 0;
 385                         }
 386                 }
 387                 dict = PyDict_New();  /* New reference. */
 388                 if (value_list->meta) {
 389                         int i, num;
 390                         char **table;
 391                         meta_data_t *meta = value_list->meta;
 392
 393                         num = meta_data_toc(meta, &table);
 394                         for (i = 0; i < num; ++i) {
 395                                 int type;
 396                                 char *string;
 397                                 int64_t si;
 398                                 uint64_t ui;
 399                                 double d;
 400                                 _Bool b;
 401
 402                                 type = meta_data_type(meta, table[i]);
 403                                 if (type == MD_TYPE_STRING) {
 404                                         if (meta_data_get_string(meta, table[i], &string))
 405                                                 continue;
 406                                         temp = cpy_string_to_unicode_or_bytes(string);  /* New reference. */
 407                                         free(string);
 408                                         PyDict_SetItemString(dict, table[i], temp);
 409                                         Py_XDECREF(temp);
 410                                 } else if (type == MD_TYPE_SIGNED_INT) {
 411                                         if (meta_data_get_signed_int(meta, table[i], &si))
 412                                                 continue;
 413                                         temp = PyObject_CallFunctionObjArgs((void *) &SignedType, PyLong_FromLongLong(si), (void *) 0);  /* New reference. */
 414                                         PyDict_SetItemString(dict, table[i], temp);
 415                                         Py_XDECREF(temp);
 416                                 } else if (type == MD_TYPE_UNSIGNED_INT) {
 417                                         if (meta_data_get_unsigned_int(meta, table[i], &ui))
 418                                                 continue;
 419                                         temp = PyObject_CallFunctionObjArgs((void *) &UnsignedType, PyLong_FromUnsignedLongLong(ui), (void *) 0);  /* New reference. */
 420                                         PyDict_SetItemString(dict, table[i], temp);
 421                                         Py_XDECREF(temp);
 422                                 } else if (type == MD_TYPE_DOUBLE) {
 423                                         if (meta_data_get_double(meta, table[i], &d))
 424                                                 continue;
 425                                         temp = PyFloat_FromDouble(d);  /* New reference. */
 426                                         PyDict_SetItemString(dict, table[i], temp);
 427                                         Py_XDECREF(temp);
 428                                 } else if (type == MD_TYPE_BOOLEAN) {
 429                                         if (meta_data_get_boolean(meta, table[i], &b))
 430                                                 continue;
 431                                         if (b)
 432                                                 PyDict_SetItemString(dict, table[i], Py_True);
 433                                         else
 434                                                 PyDict_SetItemString(dict, table[i], Py_False);
 435                                 }
 436                                 free(table[i]);
 437                         }
 438                         free(table);
 439                 }
 440                 v = (Values *) Values_New(); /* New reference. */
 441                 sstrncpy(v->data.host, value_list->host, sizeof(v->data.host));
 442                 sstrncpy(v->data.type, value_list->type, sizeof(v->data.type));
 443                 sstrncpy(v->data.type_instance, value_list->type_instance, sizeof(v->data.type_instance));
 444                 sstrncpy(v->data.plugin, value_list->plugin, sizeof(v->data.plugin));
 445                 sstrncpy(v->data.plugin_instance, value_list->plugin_instance, sizeof(v->data.plugin_instance));
 446                 v->data.time = CDTIME_T_TO_DOUBLE(value_list->time);
 447                 v->interval = CDTIME_T_TO_DOUBLE(value_list->interval);
 448                 Py_CLEAR(v->values);
 449                 v->values = list;
 450                 Py_CLEAR(v->meta);
 451                 v->meta = dict;  /* Steals a reference. */
 452                 ret = PyObject_CallFunctionObjArgs(c->callback, v, c->data, (void *) 0); /* New reference. */
 453                 Py_XDECREF(v);
 454                 if (ret == NULL) {
 455                         cpy_log_exception("write callback");
 456                 } else {
 457                         Py_DECREF(ret);
 458                 }
 459         CPY_RELEASE_THREADS
 460         return 0;
 461 }
 462
 463 static int cpy_notification_callback(const notification_t *notification, user_data_t *data) {
 464         cpy_callback_t *c = data->data;
 465         PyObject *ret, *notify;
 466         Notification *n;
 467
 468         CPY_LOCK_THREADS
 469                 notify = Notification_New(); /* New reference. */
 470                 n = (Notification *) notify;
 471                 sstrncpy(n->data.host, notification->host, sizeof(n->data.host));
 472                 sstrncpy(n->data.type, notification->type, sizeof(n->data.type));
 473                 sstrncpy(n->data.type_instance, notification->type_instance, sizeof(n->data.type_instance));
 474                 sstrncpy(n->data.plugin, notification->plugin, sizeof(n->data.plugin));
 475                 sstrncpy(n->data.plugin_instance, notification->plugin_instance, sizeof(n->data.plugin_instance));
 476                 n->data.time = CDTIME_T_TO_DOUBLE(notification->time);
 477                 sstrncpy(n->message, notification->message, sizeof(n->message));
 478                 n->severity = notification->severity;
 479                 ret = PyObject_CallFunctionObjArgs(c->callback, n, c->data, (void *) 0); /* New reference. */
 480                 Py_XDECREF(notify);
 481                 if (ret == NULL) {
 482                         cpy_log_exception("notification callback");
 483                 } else {
 484                         Py_DECREF(ret);
 485                 }
 486         CPY_RELEASE_THREADS
 487         return 0;
 488 }
 489
 490 static void cpy_log_callback(int severity, const char *message, user_data_t *data) {
 491         cpy_callback_t * c = data->data;
 492         PyObject *ret, *text;
 493
 494         CPY_LOCK_THREADS
 495         text = cpy_string_to_unicode_or_bytes(message);  /* New reference. */
 496         if (c->data == NULL)
 497                 ret = PyObject_CallFunction(c->callback, "iN", severity, text); /* New reference. Steals a reference from "text". */
 498         else
 499                 ret = PyObject_CallFunction(c->callback, "iNO", severity, text, c->data); /* New reference. Steals a reference from "text". */
 500
 501         if (ret == NULL) {
 502                 /* FIXME */
 503                 /* Do we really want to trigger a log callback because a log callback failed?
 504                  * Probably not. */
 505                 PyErr_Print();
 506                 /* In case someone wanted to be clever, replaced stderr and failed at that. */
 507                 PyErr_Clear();
 508         } else {
 509                 Py_DECREF(ret);
 510         }
 511         CPY_RELEASE_THREADS
 512 }
 513
 514 static void cpy_flush_callback(int timeout, const char *id, user_data_t *data) {
 515         cpy_callback_t * c = data->data;
 516         PyObject *ret, *text;
 517
 518         CPY_LOCK_THREADS
 519         text = cpy_string_to_unicode_or_bytes(id);
 520         if (c->data == NULL)
 521                 ret = PyObject_CallFunction(c->callback, "iN", timeout, text); /* New reference. */
 522         else
 523                 ret = PyObject_CallFunction(c->callback, "iNO", timeout, text, c->data); /* New reference. */
 524
 525         if (ret == NULL) {
 526                 cpy_log_exception("flush callback");
 527         } else {
 528                 Py_DECREF(ret);
 529         }
 530         CPY_RELEASE_THREADS
 531 }
 532
 533 static PyObject *cpy_register_generic(cpy_callback_t **list_head, PyObject *args, PyObject *kwds) {
 534         char buf[512];
 535         cpy_callback_t *c;
 536         char *name = NULL;
 537         PyObject *callback = NULL, *data = NULL, *mod = NULL;
 538         static char *kwlist[] = {"callback", "data", "name", NULL};
 539
 540         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|Oet", kwlist, &callback, &data, NULL, &name) == 0) return NULL;
 541         if (PyCallable_Check(callback) == 0) {
 542                 PyMem_Free(name);
 543                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 544                 return NULL;
 545         }
 546         cpy_build_name(buf, sizeof(buf), callback, name);
 547
 548         Py_INCREF(callback);
 549         Py_XINCREF(data);
 550         c = malloc(sizeof(*c));
 551         c->name = strdup(buf);
 552         c->callback = callback;
 553         c->data = data;
 554         c->next = *list_head;
 555         *list_head = c;
 556         Py_XDECREF(mod);
 557         PyMem_Free(name);
 558         return cpy_string_to_unicode_or_bytes(buf);
 559 }
 560
 561 static PyObject *float_or_none(float number) {
 562         if (isnan(number)) {
 563                 Py_RETURN_NONE;
 564         }
 565         return PyFloat_FromDouble(number);
 566 }
 567
 568 static PyObject *cpy_get_dataset(PyObject *self, PyObject *args) {
 569         int i;
 570         char *name;
 571         const data_set_t *ds;
 572         PyObject *list, *tuple;
 573
 574         if (PyArg_ParseTuple(args, "et", NULL, &name) == 0) return NULL;
 575         ds = plugin_get_ds(name);
 576         PyMem_Free(name);
 577         if (ds == NULL) {
 578                 PyErr_Format(PyExc_TypeError, "Dataset %s not found", name);
 579                 return NULL;
 580         }
 581         list = PyList_New(ds->ds_num); /* New reference. */
 582         for (i = 0; i < ds->ds_num; ++i) {
 583                 tuple = PyTuple_New(4);
 584                 PyTuple_SET_ITEM(tuple, 0, cpy_string_to_unicode_or_bytes(ds->ds[i].name));
 585                 PyTuple_SET_ITEM(tuple, 1, cpy_string_to_unicode_or_bytes(DS_TYPE_TO_STRING(ds->ds[i].type)));
 586                 PyTuple_SET_ITEM(tuple, 2, float_or_none(ds->ds[i].min));
 587                 PyTuple_SET_ITEM(tuple, 3, float_or_none(ds->ds[i].max));
 588                 PyList_SET_ITEM(list, i, tuple);
 589         }
 590         return list;
 591 }
 592
 593 static PyObject *cpy_flush(PyObject *self, PyObject *args, PyObject *kwds) {
 594         int timeout = -1;
 595         char *plugin = NULL, *identifier = NULL;
 596         static char *kwlist[] = {"plugin", "timeout", "identifier", NULL};
 597
 598         if (PyArg_ParseTupleAndKeywords(args, kwds, "|etiet", kwlist, NULL, &plugin, &timeout, NULL, &identifier) == 0) return NULL;
 599         Py_BEGIN_ALLOW_THREADS
 600         plugin_flush(plugin, timeout, identifier);
 601         Py_END_ALLOW_THREADS
 602         PyMem_Free(plugin);
 603         PyMem_Free(identifier);
 604         Py_RETURN_NONE;
 605 }
 606
 607 static PyObject *cpy_register_config(PyObject *self, PyObject *args, PyObject *kwds) {
 608         return cpy_register_generic(&cpy_config_callbacks, args, kwds);
 609 }
 610
 611 static PyObject *cpy_register_init(PyObject *self, PyObject *args, PyObject *kwds) {
 612         return cpy_register_generic(&cpy_init_callbacks, args, kwds);
 613 }
 614
 615 typedef int reg_function_t(const char *name, void *callback, void *data);
 616
 617 static PyObject *cpy_register_generic_userdata(void *reg, void *handler, PyObject *args, PyObject *kwds) {
 618         char buf[512];
 619         reg_function_t *register_function = (reg_function_t *) reg;
 620         cpy_callback_t *c = NULL;
 621         user_data_t *user_data = NULL;
 622         char *name = NULL;
 623         PyObject *callback = NULL, *data = NULL;
 624         static char *kwlist[] = {"callback", "data", "name", NULL};
 625
 626         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|Oet", kwlist, &callback, &data, NULL, &name) == 0) return NULL;
 627         if (PyCallable_Check(callback) == 0) {
 628                 PyMem_Free(name);
 629                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 630                 return NULL;
 631         }
 632         cpy_build_name(buf, sizeof(buf), callback, name);
 633         PyMem_Free(name);
 634
 635         Py_INCREF(callback);
 636         Py_XINCREF(data);
 637         c = malloc(sizeof(*c));
 638         c->name = strdup(buf);
 639         c->callback = callback;
 640         c->data = data;
 641         c->next = NULL;
 642         user_data = malloc(sizeof(*user_data));
 643         user_data->free_func = cpy_destroy_user_data;
 644         user_data->data = c;
 645         register_function(buf, handler, user_data);
 646         return cpy_string_to_unicode_or_bytes(buf);
 647 }
 648
 649 static PyObject *cpy_register_read(PyObject *self, PyObject *args, PyObject *kwds) {
 650         char buf[512];
 651         cpy_callback_t *c = NULL;
 652         user_data_t *user_data = NULL;
 653         double interval = 0;
 654         char *name = NULL;
 655         PyObject *callback = NULL, *data = NULL;
 656         struct timespec ts;
 657         static char *kwlist[] = {"callback", "interval", "data", "name", NULL};
 658
 659         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|dOet", kwlist, &callback, &interval, &data, NULL, &name) == 0) return NULL;
 660         if (PyCallable_Check(callback) == 0) {
 661                 PyMem_Free(name);
 662                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 663                 return NULL;
 664         }
 665         cpy_build_name(buf, sizeof(buf), callback, name);
 666         PyMem_Free(name);
 667
 668         Py_INCREF(callback);
 669         Py_XINCREF(data);
 670         c = malloc(sizeof(*c));
 671         c->name = strdup(buf);
 672         c->callback = callback;
 673         c->data = data;
 674         c->next = NULL;
 675         user_data = malloc(sizeof(*user_data));
 676         user_data->free_func = cpy_destroy_user_data;
 677         user_data->data = c;
 678         ts.tv_sec = interval;
 679         ts.tv_nsec = (interval - ts.tv_sec) * 1000000000;
 680         plugin_register_complex_read(/* group = */ NULL, buf,
 681                         cpy_read_callback, &ts, user_data);
 682         return cpy_string_to_unicode_or_bytes(buf);
 683 }
 684
 685 static PyObject *cpy_register_log(PyObject *self, PyObject *args, PyObject *kwds) {
 686         return cpy_register_generic_userdata((void *) plugin_register_log,
 687                         (void *) cpy_log_callback, args, kwds);
 688 }
 689
 690 static PyObject *cpy_register_write(PyObject *self, PyObject *args, PyObject *kwds) {
 691         return cpy_register_generic_userdata((void *) plugin_register_write,
 692                         (void *) cpy_write_callback, args, kwds);
 693 }
 694
 695 static PyObject *cpy_register_notification(PyObject *self, PyObject *args, PyObject *kwds) {
 696         return cpy_register_generic_userdata((void *) plugin_register_notification,
 697                         (void *) cpy_notification_callback, args, kwds);
 698 }
 699
 700 static PyObject *cpy_register_flush(PyObject *self, PyObject *args, PyObject *kwds) {
 701         return cpy_register_generic_userdata((void *) plugin_register_flush,
 702                         (void *) cpy_flush_callback, args, kwds);
 703 }
 704
 705 static PyObject *cpy_register_shutdown(PyObject *self, PyObject *args, PyObject *kwds) {
 706         return cpy_register_generic(&cpy_shutdown_callbacks, args, kwds);
 707 }
 708
 709 static PyObject *cpy_error(PyObject *self, PyObject *args) {
 710         char *text;
 711         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 712         Py_BEGIN_ALLOW_THREADS
 713         plugin_log(LOG_ERR, "%s", text);
 714         Py_END_ALLOW_THREADS
 715         PyMem_Free(text);
 716         Py_RETURN_NONE;
 717 }
 718
 719 static PyObject *cpy_warning(PyObject *self, PyObject *args) {
 720         char *text;
 721         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 722         Py_BEGIN_ALLOW_THREADS
 723         plugin_log(LOG_WARNING, "%s", text);
 724         Py_END_ALLOW_THREADS
 725         PyMem_Free(text);
 726         Py_RETURN_NONE;
 727 }
 728
 729 static PyObject *cpy_notice(PyObject *self, PyObject *args) {
 730         char *text;
 731         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 732         Py_BEGIN_ALLOW_THREADS
 733         plugin_log(LOG_NOTICE, "%s", text);
 734         Py_END_ALLOW_THREADS
 735         PyMem_Free(text);
 736         Py_RETURN_NONE;
 737 }
 738
 739 static PyObject *cpy_info(PyObject *self, PyObject *args) {
 740         char *text;
 741         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 742         Py_BEGIN_ALLOW_THREADS
 743         plugin_log(LOG_INFO, "%s", text);
 744         Py_END_ALLOW_THREADS
 745         PyMem_Free(text);
 746         Py_RETURN_NONE;
 747 }
 748
 749 static PyObject *cpy_debug(PyObject *self, PyObject *args) {
 750 #ifdef COLLECT_DEBUG
 751         char *text;
 752         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 753         Py_BEGIN_ALLOW_THREADS
 754         plugin_log(LOG_DEBUG, "%s", text);
 755         Py_END_ALLOW_THREADS
 756         PyMem_Free(text);
 757 #endif
 758         Py_RETURN_NONE;
 759 }
 760
 761 static PyObject *cpy_unregister_generic(cpy_callback_t **list_head, PyObject *arg, const char *desc) {
 762         char buf[512];
 763         const char *name;
 764         cpy_callback_t *prev = NULL, *tmp;
 765
 766         Py_INCREF(arg);
 767         name = cpy_unicode_or_bytes_to_string(&arg);
 768         if (name == NULL) {
 769                 PyErr_Clear();
 770                 if (!PyCallable_Check(arg)) {
 771                         PyErr_SetString(PyExc_TypeError, "This function needs a string or a callable object as its only parameter.");
 772                         Py_DECREF(arg);
 773                         return NULL;
 774                 }
 775                 cpy_build_name(buf, sizeof(buf), arg, NULL);
 776                 name = buf;
 777         }
 778         for (tmp = *list_head; tmp; prev = tmp, tmp = tmp->next)
 779                 if (strcmp(name, tmp->name) == 0)
 780                         break;
 781
 782         Py_DECREF(arg);
 783         if (tmp == NULL) {
 784                 PyErr_Format(PyExc_RuntimeError, "Unable to unregister %s callback '%s'.", desc, name);
 785                 return NULL;
 786         }
 787         /* Yes, this is actually save. To call this function the caller has to
 788          * hold the GIL. Well, save as long as there is only one GIL anyway ... */
 789         if (prev == NULL)
 790                 *list_head = tmp->next;
 791         else
 792                 prev->next = tmp->next;
 793         cpy_destroy_user_data(tmp);
 794         Py_RETURN_NONE;
 795 }
 796
 797 typedef int cpy_unregister_function_t(const char *name);
 798
 799 static PyObject *cpy_unregister_generic_userdata(cpy_unregister_function_t *unreg, PyObject *arg, const char *desc) {
 800         char buf[512];
 801         const char *name;
 802
 803         Py_INCREF(arg);
 804         name = cpy_unicode_or_bytes_to_string(&arg);
 805         if (name == NULL) {
 806                 PyErr_Clear();
 807                 if (!PyCallable_Check(arg)) {
 808                         PyErr_SetString(PyExc_TypeError, "This function needs a string or a callable object as its only parameter.");
 809                         Py_DECREF(arg);
 810                         return NULL;
 811                 }
 812                 cpy_build_name(buf, sizeof(buf), arg, NULL);
 813                 name = buf;
 814         }
 815         if (unreg(name) == 0) {
 816                 Py_DECREF(arg);
 817                 Py_RETURN_NONE;
 818         }
 819         PyErr_Format(PyExc_RuntimeError, "Unable to unregister %s callback '%s'.", desc, name);
 820         Py_DECREF(arg);
 821         return NULL;
 822 }
 823
 824 static PyObject *cpy_unregister_log(PyObject *self, PyObject *arg) {
 825         return cpy_unregister_generic_userdata(plugin_unregister_log, arg, "log");
 826 }
 827
 828 static PyObject *cpy_unregister_init(PyObject *self, PyObject *arg) {
 829         return cpy_unregister_generic(&cpy_init_callbacks, arg, "init");
 830 }
 831
 832 static PyObject *cpy_unregister_config(PyObject *self, PyObject *arg) {
 833         return cpy_unregister_generic(&cpy_config_callbacks, arg, "config");
 834 }
 835
 836 static PyObject *cpy_unregister_read(PyObject *self, PyObject *arg) {
 837         return cpy_unregister_generic_userdata(plugin_unregister_read, arg, "read");
 838 }
 839
 840 static PyObject *cpy_unregister_write(PyObject *self, PyObject *arg) {
 841         return cpy_unregister_generic_userdata(plugin_unregister_write, arg, "write");
 842 }
 843
 844 static PyObject *cpy_unregister_notification(PyObject *self, PyObject *arg) {
 845         return cpy_unregister_generic_userdata(plugin_unregister_notification, arg, "notification");
 846 }
 847
 848 static PyObject *cpy_unregister_flush(PyObject *self, PyObject *arg) {
 849         return cpy_unregister_generic_userdata(plugin_unregister_flush, arg, "flush");
 850 }
 851
 852 static PyObject *cpy_unregister_shutdown(PyObject *self, PyObject *arg) {
 853         return cpy_unregister_generic(&cpy_shutdown_callbacks, arg, "shutdown");
 854 }
 855
 856 static PyMethodDef cpy_methods[] = {
 857         {"debug", cpy_debug, METH_VARARGS, log_doc},
 858         {"info", cpy_info, METH_VARARGS, log_doc},
 859         {"notice", cpy_notice, METH_VARARGS, log_doc},
 860         {"warning", cpy_warning, METH_VARARGS, log_doc},
 861         {"error", cpy_error, METH_VARARGS, log_doc},
 862         {"get_dataset", (PyCFunction) cpy_get_dataset, METH_VARARGS, get_ds_doc},
 863         {"flush", (PyCFunction) cpy_flush, METH_VARARGS | METH_KEYWORDS, flush_doc},
 864         {"register_log", (PyCFunction) cpy_register_log, METH_VARARGS | METH_KEYWORDS, reg_log_doc},
 865         {"register_init", (PyCFunction) cpy_register_init, METH_VARARGS | METH_KEYWORDS, reg_init_doc},
 866         {"register_config", (PyCFunction) cpy_register_config, METH_VARARGS | METH_KEYWORDS, reg_config_doc},
 867         {"register_read", (PyCFunction) cpy_register_read, METH_VARARGS | METH_KEYWORDS, reg_read_doc},
 868         {"register_write", (PyCFunction) cpy_register_write, METH_VARARGS | METH_KEYWORDS, reg_write_doc},
 869         {"register_notification", (PyCFunction) cpy_register_notification, METH_VARARGS | METH_KEYWORDS, reg_notification_doc},
 870         {"register_flush", (PyCFunction) cpy_register_flush, METH_VARARGS | METH_KEYWORDS, reg_flush_doc},
 871         {"register_shutdown", (PyCFunction) cpy_register_shutdown, METH_VARARGS | METH_KEYWORDS, reg_shutdown_doc},
 872         {"unregister_log", cpy_unregister_log, METH_O, unregister_doc},
 873         {"unregister_init", cpy_unregister_init, METH_O, unregister_doc},
 874         {"unregister_config", cpy_unregister_config, METH_O, unregister_doc},
 875         {"unregister_read", cpy_unregister_read, METH_O, unregister_doc},
 876         {"unregister_write", cpy_unregister_write, METH_O, unregister_doc},
 877         {"unregister_notification", cpy_unregister_notification, METH_O, unregister_doc},
 878         {"unregister_flush", cpy_unregister_flush, METH_O, unregister_doc},
 879         {"unregister_shutdown", cpy_unregister_shutdown, METH_O, unregister_doc},
 880         {0, 0, 0, 0}
 881 };
 882
 883 static int cpy_shutdown(void) {
 884         cpy_callback_t *c;
 885         PyObject *ret;
 886
 887         /* This can happen if the module was loaded but not configured. */
 888         if (state != NULL)
 889                 PyEval_RestoreThread(state);
 890
 891         for (c = cpy_shutdown_callbacks; c; c = c->next) {
 892                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 893                 if (ret == NULL)
 894                         cpy_log_exception("shutdown callback");
 895                 else
 896                         Py_DECREF(ret);
 897         }
 898         PyErr_Print();
 899         Py_Finalize();
 900         return 0;
 901 }
 902
 903 static void cpy_int_handler(int sig) {
 904         return;
 905 }
 906
 907 static void *cpy_interactive(void *data) {
 908         sigset_t sigset;
 909         struct sigaction sig_int_action, old;
 910
 911         /* Signal handler in a plugin? Bad stuff, but the best way to
 912          * handle it I guess. In an interactive session people will
 913          * press Ctrl+C at some time, which will generate a SIGINT.
 914          * This will cause collectd to shutdown, thus killing the
 915          * interactive interpreter, and leaving the terminal in a
 916          * mess. Chances are, this isn't what the user wanted to do.
 917          *
 918          * So this is the plan:
 919          * 1. Block SIGINT in the main thread.
 920          * 2. Install our own signal handler that does nothing.
 921          * 3. Unblock SIGINT in the interactive thread.
 922          *
 923          * This will make sure that SIGINT won't kill collectd but
 924          * still interrupt syscalls like sleep and pause.
 925          * It does not raise a KeyboardInterrupt exception because so
 926          * far nobody managed to figure out how to do that. */
 927         memset (&sig_int_action, '\0', sizeof (sig_int_action));
 928         sig_int_action.sa_handler = cpy_int_handler;
 929         sigaction (SIGINT, &sig_int_action, &old);
 930
 931         sigemptyset(&sigset);
 932         sigaddset(&sigset, SIGINT);
 933         pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 934         PyEval_AcquireThread(state);
 935         if (PyImport_ImportModule("readline") == NULL) {
 936                 /* This interactive session will suck. */
 937                 cpy_log_exception("interactive session init");
 938         }
 939         PyRun_InteractiveLoop(stdin, "<stdin>");
 940         PyErr_Print();
 941         PyEval_ReleaseThread(state);
 942         NOTICE("python: Interactive interpreter exited, stopping collectd ...");
 943         /* Restore the original collectd SIGINT handler and raise SIGINT.
 944          * The main thread still has SIGINT blocked and there's nothing we
 945          * can do about that so this thread will handle it. But that's not
 946          * important, except that it won't interrupt the main loop and so
 947          * it might take a few seconds before collectd really shuts down. */
 948         sigaction (SIGINT, &old, NULL);
 949         raise(SIGINT);
 950         pause();
 951         return NULL;
 952 }
 953
 954 static int cpy_init(void) {
 955         cpy_callback_t *c;
 956         PyObject *ret;
 957         static pthread_t thread;
 958         sigset_t sigset;
 959
 960         if (!Py_IsInitialized()) {
 961                 WARNING("python: Plugin loaded but not configured.");
 962                 plugin_unregister_shutdown("python");
 963                 return 0;
 964         }
 965         PyEval_InitThreads();
 966         /* Now it's finally OK to use python threads. */
 967         for (c = cpy_init_callbacks; c; c = c->next) {
 968                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 969                 if (ret == NULL)
 970                         cpy_log_exception("init callback");
 971                 else
 972                         Py_DECREF(ret);
 973         }
 974         sigemptyset(&sigset);
 975         sigaddset(&sigset, SIGINT);
 976         pthread_sigmask(SIG_BLOCK, &sigset, NULL);
 977         state = PyEval_SaveThread();
 978         if (do_interactive) {
 979                 if (plugin_thread_create(&thread, NULL, cpy_interactive, NULL)) {
 980                         ERROR("python: Error creating thread for interactive interpreter.");
 981                 }
 982         }
 983
 984         return 0;
 985 }
 986
 987 static PyObject *cpy_oconfig_to_pyconfig(oconfig_item_t *ci, PyObject *parent) {
 988         int i;
 989         PyObject *item, *values, *children, *tmp;
 990
 991         if (parent == NULL)
 992                 parent = Py_None;
 993
 994         values = PyTuple_New(ci->values_num); /* New reference. */
 995         for (i = 0; i < ci->values_num; ++i) {
 996                 if (ci->values[i].type == OCONFIG_TYPE_STRING) {
 997                         PyTuple_SET_ITEM(values, i, cpy_string_to_unicode_or_bytes(ci->values[i].value.string));
 998                 } else if (ci->values[i].type == OCONFIG_TYPE_NUMBER) {
 999                         PyTuple_SET_ITEM(values, i, PyFloat_FromDouble(ci->values[i].value.number));
1000                 } else if (ci->values[i].type == OCONFIG_TYPE_BOOLEAN) {
1001                         PyTuple_SET_ITEM(values, i, PyBool_FromLong(ci->values[i].value.boolean));
1002                 }
1003         }
1004
1005         tmp = cpy_string_to_unicode_or_bytes(ci->key);
1006         item = PyObject_CallFunction((void *) &ConfigType, "NONO", tmp, parent, values, Py_None);
1007         if (item == NULL)
1008                 return NULL;
1009         children = PyTuple_New(ci->children_num); /* New reference. */
1010         for (i = 0; i < ci->children_num; ++i) {
1011                 PyTuple_SET_ITEM(children, i, cpy_oconfig_to_pyconfig(ci->children + i, item));
1012         }
1013         tmp = ((Config *) item)->children;
1014         ((Config *) item)->children = children;
1015         Py_XDECREF(tmp);
1016         return item;
1017 }
1018
1019 #ifdef IS_PY3K
1020 static struct PyModuleDef collectdmodule = {
1021         PyModuleDef_HEAD_INIT,
1022         "collectd",   /* name of module */
1023         "The python interface to collectd", /* module documentation, may be NULL */
1024         -1,
1025         cpy_methods
1026 };
1027
1028 PyMODINIT_FUNC PyInit_collectd(void) {
1029         return PyModule_Create(&collectdmodule);
1030 }
1031 #endif
1032
1033 static int cpy_init_python() {
1034         PyObject *sys;
1035         PyObject *module;
1036
1037 #ifdef IS_PY3K
1038         wchar_t *argv = L"";
1039         /* Add a builtin module, before Py_Initialize */
1040         PyImport_AppendInittab("collectd", PyInit_collectd);
1041 #else
1042         char *argv = "";
1043 #endif
1044
1045         Py_Initialize();
1046
1047         PyType_Ready(&ConfigType);
1048         PyType_Ready(&PluginDataType);
1049         ValuesType.tp_base = &PluginDataType;
1050         PyType_Ready(&ValuesType);
1051         NotificationType.tp_base = &PluginDataType;
1052         PyType_Ready(&NotificationType);
1053         SignedType.tp_base = &PyLong_Type;
1054         PyType_Ready(&SignedType);
1055         UnsignedType.tp_base = &PyLong_Type;
1056         PyType_Ready(&UnsignedType);
1057         sys = PyImport_ImportModule("sys"); /* New reference. */
1058         if (sys == NULL) {
1059                 cpy_log_exception("python initialization");
1060                 return 1;
1061         }
1062         sys_path = PyObject_GetAttrString(sys, "path"); /* New reference. */
1063         Py_DECREF(sys);
1064         if (sys_path == NULL) {
1065                 cpy_log_exception("python initialization");
1066                 return 1;
1067         }
1068         PySys_SetArgv(1, &argv);
1069         PyList_SetSlice(sys_path, 0, 1, NULL);
1070
1071 #ifdef IS_PY3K
1072         module = PyImport_ImportModule("collectd");
1073 #else
1074         module = Py_InitModule("collectd", cpy_methods); /* Borrowed reference. */
1075 #endif
1076         PyModule_AddObject(module, "Config", (void *) &ConfigType); /* Steals a reference. */
1077         PyModule_AddObject(module, "Values", (void *) &ValuesType); /* Steals a reference. */
1078         PyModule_AddObject(module, "Notification", (void *) &NotificationType); /* Steals a reference. */
1079         PyModule_AddObject(module, "Signed", (void *) &SignedType); /* Steals a reference. */
1080         PyModule_AddObject(module, "Unsigned", (void *) &UnsignedType); /* Steals a reference. */
1081         PyModule_AddIntConstant(module, "LOG_DEBUG", LOG_DEBUG);
1082         PyModule_AddIntConstant(module, "LOG_INFO", LOG_INFO);
1083         PyModule_AddIntConstant(module, "LOG_NOTICE", LOG_NOTICE);
1084         PyModule_AddIntConstant(module, "LOG_WARNING", LOG_WARNING);
1085         PyModule_AddIntConstant(module, "LOG_ERROR", LOG_ERR);
1086         PyModule_AddIntConstant(module, "NOTIF_FAILURE", NOTIF_FAILURE);
1087         PyModule_AddIntConstant(module, "NOTIF_WARNING", NOTIF_WARNING);
1088         PyModule_AddIntConstant(module, "NOTIF_OKAY", NOTIF_OKAY);
1089         PyModule_AddStringConstant(module, "DS_TYPE_COUNTER", DS_TYPE_TO_STRING(DS_TYPE_COUNTER));
1090         PyModule_AddStringConstant(module, "DS_TYPE_GAUGE", DS_TYPE_TO_STRING(DS_TYPE_GAUGE));
1091         PyModule_AddStringConstant(module, "DS_TYPE_DERIVE", DS_TYPE_TO_STRING(DS_TYPE_DERIVE));
1092         PyModule_AddStringConstant(module, "DS_TYPE_ABSOLUTE", DS_TYPE_TO_STRING(DS_TYPE_ABSOLUTE));
1093         return 0;
1094 }
1095
1096 static int cpy_config(oconfig_item_t *ci) {
1097         int i;
1098         PyObject *tb;
1099
1100         /* Ok in theory we shouldn't do initialization at this point
1101          * but we have to. In order to give python scripts a chance
1102          * to register a config callback we need to be able to execute
1103          * python code during the config callback so we have to start
1104          * the interpreter here. */
1105         /* Do *not* use the python "thread" module at this point! */
1106
1107         if (!Py_IsInitialized() && cpy_init_python()) return 1;
1108
1109         for (i = 0; i < ci->children_num; ++i) {
1110                 oconfig_item_t *item = ci->children + i;
1111
1112                 if (strcasecmp(item->key, "Interactive") == 0) {
1113                         if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_BOOLEAN)
1114                                 continue;
1115                         do_interactive = item->values[0].value.boolean;
1116                 } else if (strcasecmp(item->key, "Encoding") == 0) {
1117                         if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_STRING)
1118                                 continue;
1119 #ifdef IS_PY3K
1120                         NOTICE("python: \"Encoding\" was used in the config file but Python3 was used, which does not support changing encodings. Ignoring this.");
1121 #else
1122                         /* Why is this even necessary? And undocumented? */
1123                         if (PyUnicode_SetDefaultEncoding(item->values[0].value.string))
1124                                 cpy_log_exception("setting default encoding");
1125 #endif
1126                 } else if (strcasecmp(item->key, "LogTraces") == 0) {
1127                         if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_BOOLEAN)
1128                                 continue;
1129                         if (!item->values[0].value.boolean) {
1130                                 Py_XDECREF(cpy_format_exception);
1131                                 cpy_format_exception = NULL;
1132                                 continue;
1133                         }
1134                         if (cpy_format_exception)
1135                                 continue;
1136                         tb = PyImport_ImportModule("traceback"); /* New reference. */
1137                         if (tb == NULL) {
1138                                 cpy_log_exception("python initialization");
1139                                 continue;
1140                         }
1141                         cpy_format_exception = PyObject_GetAttrString(tb, "format_exception"); /* New reference. */
1142                         Py_DECREF(tb);
1143                         if (cpy_format_exception == NULL)
1144                                 cpy_log_exception("python initialization");
1145                 } else if (strcasecmp(item->key, "ModulePath") == 0) {
1146                         char *dir = NULL;
1147                         PyObject *dir_object;
1148
1149                         if (cf_util_get_string(item, &dir) != 0)
1150                                 continue;
1151                         dir_object = cpy_string_to_unicode_or_bytes(dir); /* New reference. */
1152                         if (dir_object == NULL) {
1153                                 ERROR("python plugin: Unable to convert \"%s\" to "
1154                                       "a python object.", dir);
1155                                 free(dir);
1156                                 cpy_log_exception("python initialization");
1157                                 continue;
1158                         }
1159                         if (PyList_Insert(sys_path, 0, dir_object) != 0) {
1160                                 ERROR("python plugin: Unable to prepend \"%s\" to "
1161                                       "python module path.", dir);
1162                                 cpy_log_exception("python initialization");
1163                         }
1164                         Py_DECREF(dir_object);
1165                         free(dir);
1166                 } else if (strcasecmp(item->key, "Import") == 0) {
1167                         char *module_name = NULL;
1168                         PyObject *module;
1169
1170                         if (cf_util_get_string(item, &module_name) != 0)
1171                                 continue;
1172                         module = PyImport_ImportModule(module_name); /* New reference. */
1173                         if (module == NULL) {
1174                                 ERROR("python plugin: Error importing module \"%s\".", module_name);
1175                                 cpy_log_exception("importing module");
1176                         }
1177                         free(module_name);
1178                         Py_XDECREF(module);
1179                 } else if (strcasecmp(item->key, "Module") == 0) {
1180                         char *name = NULL;
1181                         cpy_callback_t *c;
1182                         PyObject *ret;
1183
1184                         if (cf_util_get_string(item, &name) != 0)
1185                                 continue;
1186                         for (c = cpy_config_callbacks; c; c = c->next) {
1187                                 if (strcasecmp(c->name + 7, name) == 0)
1188                                         break;
1189                         }
1190                         if (c == NULL) {
1191                                 WARNING("python plugin: Found a configuration for the \"%s\" plugin, "
1192                                         "but the plugin isn't loaded or didn't register "
1193                                         "a configuration callback.", name);
1194                                 free(name);
1195                                 continue;
1196                         }
1197                         free(name);
1198                         if (c->data == NULL)
1199                                 ret = PyObject_CallFunction(c->callback, "N",
1200                                         cpy_oconfig_to_pyconfig(item, NULL)); /* New reference. */
1201                         else
1202                                 ret = PyObject_CallFunction(c->callback, "NO",
1203                                         cpy_oconfig_to_pyconfig(item, NULL), c->data); /* New reference. */
1204                         if (ret == NULL)
1205                                 cpy_log_exception("loading module");
1206                         else
1207                                 Py_DECREF(ret);
1208                 } else {
1209                         WARNING("python plugin: Ignoring unknown config key \"%s\".", item->key);
1210                 }
1211         }
1212         return 0;
1213 }
1214
1215 void module_register(void) {
1216         plugin_register_complex_config("python", cpy_config);
1217         plugin_register_init("python", cpy_init);
1218         plugin_register_shutdown("python", cpy_shutdown);
1219 }