f1333f1d43ce8fa8a347d8fc0e112479615f1563
1 /**
2 * collectd - src/plugin.c
3 * Copyright (C) 2005,2006 Florian octo Forster
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Authors:
19 * Florian octo Forster <octo at verplant.org>
20 **/
22 #include "collectd.h"
24 #include <ltdl.h>
26 #if HAVE_PTHREAD_H
27 # include <pthread.h>
28 #endif
30 #include "common.h"
31 #include "plugin.h"
32 #include "configfile.h"
33 #include "utils_avltree.h"
34 #include "utils_llist.h"
35 #include "utils_cache.h"
36 #include "utils_threshold.h"
38 /*
39 * Private structures
40 */
41 struct read_func_s
42 {
43 int wait_time;
44 int wait_left;
45 int (*callback) (void);
46 enum { DONE = 0, TODO = 1, ACTIVE = 2 } needs_read;
47 };
48 typedef struct read_func_s read_func_t;
50 /*
51 * Private variables
52 */
53 static llist_t *list_init;
54 static llist_t *list_read;
55 static llist_t *list_write;
56 static llist_t *list_shutdown;
57 static llist_t *list_log;
58 static llist_t *list_notification;
60 static c_avl_tree_t *data_sets;
62 static char *plugindir = NULL;
64 static int read_loop = 1;
65 static pthread_mutex_t read_lock = PTHREAD_MUTEX_INITIALIZER;
66 static pthread_cond_t read_cond = PTHREAD_COND_INITIALIZER;
67 static pthread_t *read_threads = NULL;
68 static int read_threads_num = 0;
70 /*
71 * Static functions
72 */
73 static const char *plugin_get_dir (void)
74 {
75 if (plugindir == NULL)
76 return (PLUGINDIR);
77 else
78 return (plugindir);
79 }
81 static int register_callback (llist_t **list, const char *name, void *callback)
82 {
83 llentry_t *le;
84 char *key;
86 if ((*list == NULL)
87 && ((*list = llist_create ()) == NULL))
88 return (-1);
90 le = llist_search (*list, name);
91 if (le == NULL)
92 {
93 key = strdup (name);
94 if (key == NULL)
95 return (-1);
97 le = llentry_create (key, callback);
98 if (le == NULL)
99 {
100 free (key);
101 return (-1);
102 }
104 llist_append (*list, le);
105 }
106 else
107 {
108 le->value = callback;
109 }
111 return (0);
112 } /* int register_callback */
114 static int plugin_unregister (llist_t *list, const char *name)
115 {
116 llentry_t *e;
118 e = llist_search (list, name);
120 if (e == NULL)
121 return (-1);
123 llist_remove (list, e);
124 free (e->key);
125 llentry_destroy (e);
127 return (0);
128 } /* int plugin_unregister */
130 /*
131 * (Try to) load the shared object `file'. Won't complain if it isn't a shared
132 * object, but it will bitch about a shared object not having a
133 * ``module_register'' symbol..
134 */
135 static int plugin_load_file (char *file)
136 {
137 lt_dlhandle dlh;
138 void (*reg_handle) (void);
140 DEBUG ("file = %s", file);
142 lt_dlinit ();
143 lt_dlerror (); /* clear errors */
145 if ((dlh = lt_dlopen (file)) == NULL)
146 {
147 const char *error = lt_dlerror ();
149 ERROR ("lt_dlopen failed: %s", error);
150 fprintf (stderr, "lt_dlopen failed: %s\n", error);
151 return (1);
152 }
154 if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
155 {
156 WARNING ("Couldn't find symbol ``module_register'' in ``%s'': %s\n",
157 file, lt_dlerror ());
158 lt_dlclose (dlh);
159 return (-1);
160 }
162 (*reg_handle) ();
164 return (0);
165 }
167 static void *plugin_read_thread (void *args)
168 {
169 llentry_t *le;
170 read_func_t *rf;
171 int status;
172 int done;
174 pthread_mutex_lock (&read_lock);
176 while (read_loop != 0)
177 {
178 le = llist_head (list_read);
179 done = 0;
181 while ((read_loop != 0) && (le != NULL))
182 {
183 rf = (read_func_t *) le->value;
185 if (rf->needs_read != TODO)
186 {
187 le = le->next;
188 continue;
189 }
191 /* We will do this read function */
192 rf->needs_read = ACTIVE;
194 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Handling %s",
195 (unsigned long int) pthread_self (), le->key);
196 pthread_mutex_unlock (&read_lock);
198 status = rf->callback ();
199 done++;
201 if (status != 0)
202 {
203 if (rf->wait_time < interval_g)
204 rf->wait_time = interval_g;
205 rf->wait_left = rf->wait_time;
206 rf->wait_time = rf->wait_time * 2;
207 if (rf->wait_time > 86400)
208 rf->wait_time = 86400;
210 NOTICE ("read-function of plugin `%s' "
211 "failed. Will suspend it for %i "
212 "seconds.", le->key, rf->wait_left);
213 }
214 else
215 {
216 rf->wait_left = 0;
217 rf->wait_time = interval_g;
218 }
220 pthread_mutex_lock (&read_lock);
222 rf->needs_read = DONE;
223 le = le->next;
224 } /* while (le != NULL) */
226 if ((read_loop != 0) && (done == 0))
227 {
228 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Waiting on read_cond.",
229 (unsigned long int) pthread_self ());
230 pthread_cond_wait (&read_cond, &read_lock);
231 }
232 } /* while (read_loop) */
234 pthread_mutex_unlock (&read_lock);
236 pthread_exit (NULL);
237 return ((void *) 0);
238 } /* void *plugin_read_thread */
240 static void start_threads (int num)
241 {
242 int i;
244 if (read_threads != NULL)
245 return;
247 read_threads = (pthread_t *) calloc (num, sizeof (pthread_t));
248 if (read_threads == NULL)
249 {
250 ERROR ("plugin: start_threads: calloc failed.");
251 return;
252 }
254 read_threads_num = 0;
255 for (i = 0; i < num; i++)
256 {
257 if (pthread_create (read_threads + read_threads_num, NULL,
258 plugin_read_thread, NULL) == 0)
259 {
260 read_threads_num++;
261 }
262 else
263 {
264 ERROR ("plugin: start_threads: pthread_create failed.");
265 return;
266 }
267 } /* for (i) */
268 } /* void start_threads */
270 static void stop_threads (void)
271 {
272 int i;
274 pthread_mutex_lock (&read_lock);
275 read_loop = 0;
276 DEBUG ("plugin: stop_threads: Signalling `read_cond'");
277 pthread_cond_broadcast (&read_cond);
278 pthread_mutex_unlock (&read_lock);
280 for (i = 0; i < read_threads_num; i++)
281 {
282 if (pthread_join (read_threads[i], NULL) != 0)
283 {
284 ERROR ("plugin: stop_threads: pthread_join failed.");
285 }
286 read_threads[i] = (pthread_t) 0;
287 }
288 sfree (read_threads);
289 read_threads_num = 0;
290 } /* void stop_threads */
292 /*
293 * Public functions
294 */
295 void plugin_set_dir (const char *dir)
296 {
297 if (plugindir != NULL)
298 free (plugindir);
300 if (dir == NULL)
301 plugindir = NULL;
302 else if ((plugindir = strdup (dir)) == NULL)
303 {
304 char errbuf[1024];
305 ERROR ("strdup failed: %s",
306 sstrerror (errno, errbuf, sizeof (errbuf)));
307 }
308 }
310 #define BUFSIZE 512
311 int plugin_load (const char *type)
312 {
313 DIR *dh;
314 const char *dir;
315 char filename[BUFSIZE] = "";
316 char typename[BUFSIZE];
317 int typename_len;
318 int ret;
319 struct stat statbuf;
320 struct dirent *de;
322 DEBUG ("type = %s", type);
324 dir = plugin_get_dir ();
325 ret = 1;
327 /* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
328 * type when matching the filename */
329 if (snprintf (typename, BUFSIZE, "%s.so", type) >= BUFSIZE)
330 {
331 WARNING ("snprintf: truncated: `%s.so'", type);
332 return (-1);
333 }
334 typename_len = strlen (typename);
336 if ((dh = opendir (dir)) == NULL)
337 {
338 char errbuf[1024];
339 ERROR ("opendir (%s): %s", dir,
340 sstrerror (errno, errbuf, sizeof (errbuf)));
341 return (-1);
342 }
344 while ((de = readdir (dh)) != NULL)
345 {
346 if (strncasecmp (de->d_name, typename, typename_len))
347 continue;
349 if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
350 {
351 WARNING ("snprintf: truncated: `%s/%s'", dir, de->d_name);
352 continue;
353 }
355 if (lstat (filename, &statbuf) == -1)
356 {
357 char errbuf[1024];
358 WARNING ("stat %s: %s", filename,
359 sstrerror (errno, errbuf, sizeof (errbuf)));
360 continue;
361 }
362 else if (!S_ISREG (statbuf.st_mode))
363 {
364 /* don't follow symlinks */
365 continue;
366 }
368 if (plugin_load_file (filename) == 0)
369 {
370 /* success */
371 ret = 0;
372 break;
373 }
374 else
375 {
376 fprintf (stderr, "Unable to load plugin %s.\n", type);
377 }
378 }
380 closedir (dh);
382 if (filename[0] == '\0')
383 fprintf (stderr, "Could not find plugin %s.\n", type);
385 return (ret);
386 }
388 /*
389 * The `register_*' functions follow
390 */
391 int plugin_register_config (const char *name,
392 int (*callback) (const char *key, const char *val),
393 const char **keys, int keys_num)
394 {
395 cf_register (name, callback, keys, keys_num);
396 return (0);
397 } /* int plugin_register_config */
399 int plugin_register_complex_config (const char *type,
400 int (*callback) (oconfig_item_t *))
401 {
402 return (cf_register_complex (type, callback));
403 } /* int plugin_register_complex_config */
405 int plugin_register_init (const char *name,
406 int (*callback) (void))
407 {
408 return (register_callback (&list_init, name, (void *) callback));
409 } /* plugin_register_init */
411 int plugin_register_read (const char *name,
412 int (*callback) (void))
413 {
414 read_func_t *rf;
416 rf = (read_func_t *) malloc (sizeof (read_func_t));
417 if (rf == NULL)
418 {
419 char errbuf[1024];
420 ERROR ("plugin_register_read: malloc failed: %s",
421 sstrerror (errno, errbuf, sizeof (errbuf)));
422 return (-1);
423 }
425 memset (rf, '\0', sizeof (read_func_t));
426 rf->wait_time = interval_g;
427 rf->wait_left = 0;
428 rf->callback = callback;
429 rf->needs_read = DONE;
431 return (register_callback (&list_read, name, (void *) rf));
432 } /* int plugin_register_read */
434 int plugin_register_write (const char *name,
435 int (*callback) (const data_set_t *ds, const value_list_t *vl))
436 {
437 return (register_callback (&list_write, name, (void *) callback));
438 } /* int plugin_register_write */
440 int plugin_register_shutdown (char *name,
441 int (*callback) (void))
442 {
443 return (register_callback (&list_shutdown, name, (void *) callback));
444 } /* int plugin_register_shutdown */
446 int plugin_register_data_set (const data_set_t *ds)
447 {
448 data_set_t *ds_copy;
449 int i;
451 if ((data_sets != NULL)
452 && (c_avl_get (data_sets, ds->type, NULL) == 0))
453 {
454 NOTICE ("Replacing DS `%s' with another version.", ds->type);
455 plugin_unregister_data_set (ds->type);
456 }
457 else if (data_sets == NULL)
458 {
459 data_sets = c_avl_create ((int (*) (const void *, const void *)) strcmp);
460 if (data_sets == NULL)
461 return (-1);
462 }
464 ds_copy = (data_set_t *) malloc (sizeof (data_set_t));
465 if (ds_copy == NULL)
466 return (-1);
467 memcpy(ds_copy, ds, sizeof (data_set_t));
469 ds_copy->ds = (data_source_t *) malloc (sizeof (data_source_t)
470 * ds->ds_num);
471 if (ds_copy->ds == NULL)
472 {
473 free (ds_copy);
474 return (-1);
475 }
477 for (i = 0; i < ds->ds_num; i++)
478 memcpy (ds_copy->ds + i, ds->ds + i, sizeof (data_source_t));
480 return (c_avl_insert (data_sets, (void *) ds_copy->type, (void *) ds_copy));
481 } /* int plugin_register_data_set */
483 int plugin_register_log (char *name,
484 void (*callback) (int priority, const char *msg))
485 {
486 return (register_callback (&list_log, name, (void *) callback));
487 } /* int plugin_register_log */
489 int plugin_register_notification (const char *name,
490 int (*callback) (const notification_t *notif))
491 {
492 return (register_callback (&list_notification, name, (void *) callback));
493 } /* int plugin_register_log */
495 int plugin_unregister_config (const char *name)
496 {
497 cf_unregister (name);
498 return (0);
499 } /* int plugin_unregister_config */
501 int plugin_unregister_complex_config (const char *name)
502 {
503 cf_unregister_complex (name);
504 return (0);
505 } /* int plugin_unregister_complex_config */
507 int plugin_unregister_init (const char *name)
508 {
509 return (plugin_unregister (list_init, name));
510 }
512 int plugin_unregister_read (const char *name)
513 {
514 llentry_t *e;
516 e = llist_search (list_read, name);
518 if (e == NULL)
519 return (-1);
521 llist_remove (list_read, e);
522 free (e->value);
523 free (e->key);
524 llentry_destroy (e);
526 return (0);
527 }
529 int plugin_unregister_write (const char *name)
530 {
531 return (plugin_unregister (list_write, name));
532 }
534 int plugin_unregister_shutdown (const char *name)
535 {
536 return (plugin_unregister (list_shutdown, name));
537 }
539 int plugin_unregister_data_set (const char *name)
540 {
541 data_set_t *ds;
543 if (data_sets == NULL)
544 return (-1);
546 if (c_avl_remove (data_sets, name, NULL, (void *) &ds) != 0)
547 return (-1);
549 sfree (ds->ds);
550 sfree (ds);
552 return (0);
553 } /* int plugin_unregister_data_set */
555 int plugin_unregister_log (const char *name)
556 {
557 return (plugin_unregister (list_log, name));
558 }
560 int plugin_unregister_notification (const char *name)
561 {
562 return (plugin_unregister (list_notification, name));
563 }
565 void plugin_init_all (void)
566 {
567 int (*callback) (void);
568 llentry_t *le;
569 int status;
571 /* Init the value cache */
572 uc_init ();
574 if ((list_init == NULL) && (list_read == NULL))
575 return;
577 /* Calling all init callbacks before checking if read callbacks
578 * are available allows the init callbacks to register the read
579 * callback. */
580 le = llist_head (list_init);
581 while (le != NULL)
582 {
583 callback = (int (*) (void)) le->value;
584 status = (*callback) ();
586 if (status != 0)
587 {
588 ERROR ("Initialization of plugin `%s' "
589 "failed with status %i. "
590 "Plugin will be unloaded.",
591 le->key, status);
592 /* Plugins that register read callbacks from the init
593 * callback should take care of appropriate error
594 * handling themselves. */
595 /* FIXME: Unload _all_ functions */
596 plugin_unregister_read (le->key);
597 }
599 le = le->next;
600 }
602 /* Start read-threads */
603 if (list_read != NULL)
604 {
605 const char *rt;
606 int num;
607 rt = global_option_get ("ReadThreads");
608 num = atoi (rt);
609 start_threads ((num > 0) ? num : 5);
610 }
611 } /* void plugin_init_all */
613 void plugin_read_all (void)
614 {
615 llentry_t *le;
616 read_func_t *rf;
618 uc_check_timeout ();
620 if (list_read == NULL)
621 return;
623 pthread_mutex_lock (&read_lock);
625 le = llist_head (list_read);
626 while (le != NULL)
627 {
628 rf = (read_func_t *) le->value;
630 if (rf->needs_read != DONE)
631 {
632 le = le->next;
633 continue;
634 }
636 if (rf->wait_left > 0)
637 rf->wait_left -= interval_g;
639 if (rf->wait_left <= 0)
640 {
641 rf->needs_read = TODO;
642 }
644 le = le->next;
645 }
647 DEBUG ("plugin: plugin_read_all: Signalling `read_cond'");
648 pthread_cond_broadcast (&read_cond);
649 pthread_mutex_unlock (&read_lock);
650 } /* void plugin_read_all */
652 void plugin_shutdown_all (void)
653 {
654 int (*callback) (void);
655 llentry_t *le;
657 stop_threads ();
659 if (list_shutdown == NULL)
660 return;
662 le = llist_head (list_shutdown);
663 while (le != NULL)
664 {
665 callback = (int (*) (void)) le->value;
667 /* Advance the pointer before calling the callback allows
668 * shutdown functions to unregister themselves. If done the
669 * other way around the memory `le' points to will be freed
670 * after callback returns. */
671 le = le->next;
673 (*callback) ();
674 }
675 } /* void plugin_shutdown_all */
677 int plugin_dispatch_values (const char *name, value_list_t *vl)
678 {
679 int (*callback) (const data_set_t *, const value_list_t *);
680 data_set_t *ds;
681 llentry_t *le;
683 if (list_write == NULL)
684 {
685 ERROR ("plugin_dispatch_values: No write callback has been "
686 "registered. Please load at least one plugin "
687 "that provides a write function.");
688 return (-1);
689 }
691 if (data_sets == NULL)
692 {
693 ERROR ("plugin_dispatch_values: No data sets registered. "
694 "Could the types database be read? Check "
695 "your `TypesDB' setting!");
696 return (-1);
697 }
699 if (c_avl_get (data_sets, name, (void *) &ds) != 0)
700 {
701 INFO ("plugin_dispatch_values: Dataset not found: %s", name);
702 return (-1);
703 }
705 DEBUG ("plugin_dispatch_values: time = %u; interval = %i; "
706 "host = %s; "
707 "plugin = %s; plugin_instance = %s; "
708 "type = %s; type_instance = %s;",
709 (unsigned int) vl->time, vl->interval,
710 vl->host,
711 vl->plugin, vl->plugin_instance,
712 ds->type, vl->type_instance);
714 #if COLLECT_DEBUG
715 assert (ds->ds_num == vl->values_len);
716 #else
717 if (ds->ds_num != vl->values_len)
718 {
719 ERROR ("plugin_dispatch_values: ds->type = %s: "
720 "(ds->ds_num = %i) != "
721 "(vl->values_len = %i)",
722 ds->type, ds->ds_num, vl->values_len);
723 return (-1);
724 }
725 #endif
727 escape_slashes (vl->host, sizeof (vl->host));
728 escape_slashes (vl->plugin, sizeof (vl->plugin));
729 escape_slashes (vl->plugin_instance, sizeof (vl->plugin_instance));
730 escape_slashes (vl->type_instance, sizeof (vl->type_instance));
732 /* Update the value cache */
733 uc_update (ds, vl);
734 ut_check_threshold (ds, vl);
736 le = llist_head (list_write);
737 while (le != NULL)
738 {
739 callback = (int (*) (const data_set_t *, const value_list_t *)) le->value;
740 (*callback) (ds, vl);
742 le = le->next;
743 }
745 return (0);
746 } /* int plugin_dispatch_values */
748 int plugin_dispatch_notification (const notification_t *notif)
749 {
750 int (*callback) (const notification_t *);
751 llentry_t *le;
752 /* Possible TODO: Add flap detection here */
754 DEBUG ("plugin_dispatch_notification: severity = %i; message = %s; "
755 "time = %u; host = %s;",
756 notif->severity, notif->message,
757 (unsigned int) notif->time, notif->host);
759 /* Nobody cares for notifications */
760 if (list_notification == NULL)
761 return (-1);
763 le = llist_head (list_notification);
764 while (le != NULL)
765 {
766 callback = (int (*) (const notification_t *)) le->value;
767 (*callback) (notif);
769 le = le->next;
770 }
772 return (0);
773 } /* int plugin_dispatch_notification */
775 void plugin_log (int level, const char *format, ...)
776 {
777 char msg[512];
778 va_list ap;
780 void (*callback) (int, const char *);
781 llentry_t *le;
783 if (list_log == NULL)
784 return;
786 #if !COLLECT_DEBUG
787 if (level >= LOG_DEBUG)
788 return;
789 #endif
791 va_start (ap, format);
792 vsnprintf (msg, 512, format, ap);
793 msg[511] = '\0';
794 va_end (ap);
796 le = llist_head (list_log);
797 while (le != NULL)
798 {
799 callback = (void (*) (int, const char *)) le->value;
800 (*callback) (level, msg);
802 le = le->next;
803 }
804 } /* void plugin_log */
806 const data_set_t *plugin_get_ds (const char *name)
807 {
808 data_set_t *ds;
810 if (c_avl_get (data_sets, name, (void *) &ds) != 0)
811 {
812 DEBUG ("No such dataset registered: %s", name);
813 return (NULL);
814 }
816 return (ds);
817 } /* data_set_t *plugin_get_ds */