1 /**
2 * collectd - src/plugin.c
3 * Copyright (C) 2005-2008 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 * Sebastian Harl <sh at tokkee.org>
21 **/
23 #include "collectd.h"
25 #include <ltdl.h>
27 #if HAVE_PTHREAD_H
28 # include <pthread.h>
29 #endif
31 #include "common.h"
32 #include "plugin.h"
33 #include "configfile.h"
34 #include "utils_avltree.h"
35 #include "utils_llist.h"
36 #include "utils_cache.h"
37 #include "utils_threshold.h"
39 /*
40 * Private structures
41 */
42 struct read_func_s
43 {
44 int wait_time;
45 int wait_left;
46 int (*callback) (void);
47 enum { DONE = 0, TODO = 1, ACTIVE = 2 } needs_read;
48 };
49 typedef struct read_func_s read_func_t;
51 /*
52 * Private variables
53 */
54 static llist_t *list_init;
55 static llist_t *list_read;
56 static llist_t *list_write;
57 static llist_t *list_flush;
58 static llist_t *list_shutdown;
59 static llist_t *list_log;
60 static llist_t *list_notification;
62 static c_avl_tree_t *data_sets;
64 static char *plugindir = NULL;
66 static int read_loop = 1;
67 static pthread_mutex_t read_lock = PTHREAD_MUTEX_INITIALIZER;
68 static pthread_cond_t read_cond = PTHREAD_COND_INITIALIZER;
69 static pthread_t *read_threads = NULL;
70 static int read_threads_num = 0;
72 /*
73 * Static functions
74 */
75 static const char *plugin_get_dir (void)
76 {
77 if (plugindir == NULL)
78 return (PLUGINDIR);
79 else
80 return (plugindir);
81 }
83 static int register_callback (llist_t **list, const char *name, void *callback)
84 {
85 llentry_t *le;
86 char *key;
88 if ((*list == NULL)
89 && ((*list = llist_create ()) == NULL))
90 return (-1);
92 le = llist_search (*list, name);
93 if (le == NULL)
94 {
95 key = strdup (name);
96 if (key == NULL)
97 return (-1);
99 le = llentry_create (key, callback);
100 if (le == NULL)
101 {
102 free (key);
103 return (-1);
104 }
106 llist_append (*list, le);
107 }
108 else
109 {
110 le->value = callback;
111 }
113 return (0);
114 } /* int register_callback */
116 static int plugin_unregister (llist_t *list, const char *name)
117 {
118 llentry_t *e;
120 e = llist_search (list, name);
122 if (e == NULL)
123 return (-1);
125 llist_remove (list, e);
126 free (e->key);
127 llentry_destroy (e);
129 return (0);
130 } /* int plugin_unregister */
132 /*
133 * (Try to) load the shared object `file'. Won't complain if it isn't a shared
134 * object, but it will bitch about a shared object not having a
135 * ``module_register'' symbol..
136 */
137 static int plugin_load_file (char *file)
138 {
139 lt_dlhandle dlh;
140 void (*reg_handle) (void);
142 DEBUG ("file = %s", file);
144 lt_dlinit ();
145 lt_dlerror (); /* clear errors */
147 if ((dlh = lt_dlopen (file)) == NULL)
148 {
149 const char *error = lt_dlerror ();
151 ERROR ("lt_dlopen failed: %s", error);
152 fprintf (stderr, "lt_dlopen failed: %s\n", error);
153 return (1);
154 }
156 if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
157 {
158 WARNING ("Couldn't find symbol ``module_register'' in ``%s'': %s\n",
159 file, lt_dlerror ());
160 lt_dlclose (dlh);
161 return (-1);
162 }
164 (*reg_handle) ();
166 return (0);
167 }
169 static void *plugin_read_thread (void *args)
170 {
171 llentry_t *le;
172 read_func_t *rf;
173 int status;
174 int done;
176 pthread_mutex_lock (&read_lock);
178 while (read_loop != 0)
179 {
180 le = llist_head (list_read);
181 done = 0;
183 while ((read_loop != 0) && (le != NULL))
184 {
185 rf = (read_func_t *) le->value;
187 if (rf->needs_read != TODO)
188 {
189 le = le->next;
190 continue;
191 }
193 /* We will do this read function */
194 rf->needs_read = ACTIVE;
196 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Handling %s",
197 (unsigned long int) pthread_self (), le->key);
198 pthread_mutex_unlock (&read_lock);
200 status = rf->callback ();
201 done++;
203 if (status != 0)
204 {
205 if (rf->wait_time < interval_g)
206 rf->wait_time = interval_g;
207 rf->wait_left = rf->wait_time;
208 rf->wait_time = rf->wait_time * 2;
209 if (rf->wait_time > 86400)
210 rf->wait_time = 86400;
212 NOTICE ("read-function of plugin `%s' "
213 "failed. Will suspend it for %i "
214 "seconds.", le->key, rf->wait_left);
215 }
216 else
217 {
218 rf->wait_left = 0;
219 rf->wait_time = interval_g;
220 }
222 pthread_mutex_lock (&read_lock);
224 rf->needs_read = DONE;
225 le = le->next;
226 } /* while (le != NULL) */
228 if ((read_loop != 0) && (done == 0))
229 {
230 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Waiting on read_cond.",
231 (unsigned long int) pthread_self ());
232 pthread_cond_wait (&read_cond, &read_lock);
233 }
234 } /* while (read_loop) */
236 pthread_mutex_unlock (&read_lock);
238 pthread_exit (NULL);
239 return ((void *) 0);
240 } /* void *plugin_read_thread */
242 static void start_threads (int num)
243 {
244 int i;
246 if (read_threads != NULL)
247 return;
249 read_threads = (pthread_t *) calloc (num, sizeof (pthread_t));
250 if (read_threads == NULL)
251 {
252 ERROR ("plugin: start_threads: calloc failed.");
253 return;
254 }
256 read_threads_num = 0;
257 for (i = 0; i < num; i++)
258 {
259 if (pthread_create (read_threads + read_threads_num, NULL,
260 plugin_read_thread, NULL) == 0)
261 {
262 read_threads_num++;
263 }
264 else
265 {
266 ERROR ("plugin: start_threads: pthread_create failed.");
267 return;
268 }
269 } /* for (i) */
270 } /* void start_threads */
272 static void stop_threads (void)
273 {
274 int i;
276 pthread_mutex_lock (&read_lock);
277 read_loop = 0;
278 DEBUG ("plugin: stop_threads: Signalling `read_cond'");
279 pthread_cond_broadcast (&read_cond);
280 pthread_mutex_unlock (&read_lock);
282 for (i = 0; i < read_threads_num; i++)
283 {
284 if (pthread_join (read_threads[i], NULL) != 0)
285 {
286 ERROR ("plugin: stop_threads: pthread_join failed.");
287 }
288 read_threads[i] = (pthread_t) 0;
289 }
290 sfree (read_threads);
291 read_threads_num = 0;
292 } /* void stop_threads */
294 /*
295 * Public functions
296 */
297 void plugin_set_dir (const char *dir)
298 {
299 if (plugindir != NULL)
300 free (plugindir);
302 if (dir == NULL)
303 plugindir = NULL;
304 else if ((plugindir = strdup (dir)) == NULL)
305 {
306 char errbuf[1024];
307 ERROR ("strdup failed: %s",
308 sstrerror (errno, errbuf, sizeof (errbuf)));
309 }
310 }
312 #define BUFSIZE 512
313 int plugin_load (const char *type)
314 {
315 DIR *dh;
316 const char *dir;
317 char filename[BUFSIZE];
318 char typename[BUFSIZE];
319 int typename_len;
320 int ret;
321 struct stat statbuf;
322 struct dirent *de;
324 DEBUG ("type = %s", type);
326 dir = plugin_get_dir ();
327 ret = 1;
329 /* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
330 * type when matching the filename */
331 if (snprintf (typename, BUFSIZE, "%s.so", type) >= BUFSIZE)
332 {
333 WARNING ("snprintf: truncated: `%s.so'", type);
334 return (-1);
335 }
336 typename_len = strlen (typename);
338 if ((dh = opendir (dir)) == NULL)
339 {
340 char errbuf[1024];
341 ERROR ("opendir (%s): %s", dir,
342 sstrerror (errno, errbuf, sizeof (errbuf)));
343 return (-1);
344 }
346 while ((de = readdir (dh)) != NULL)
347 {
348 if (strncasecmp (de->d_name, typename, typename_len))
349 continue;
351 if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
352 {
353 WARNING ("snprintf: truncated: `%s/%s'", dir, de->d_name);
354 continue;
355 }
357 if (lstat (filename, &statbuf) == -1)
358 {
359 char errbuf[1024];
360 WARNING ("stat %s: %s", filename,
361 sstrerror (errno, errbuf, sizeof (errbuf)));
362 continue;
363 }
364 else if (!S_ISREG (statbuf.st_mode))
365 {
366 /* don't follow symlinks */
367 continue;
368 }
370 if (plugin_load_file (filename) == 0)
371 {
372 /* success */
373 ret = 0;
374 break;
375 }
376 else
377 {
378 fprintf (stderr, "Unable to load plugin %s.\n", type);
379 }
380 }
382 closedir (dh);
384 return (ret);
385 }
387 /*
388 * The `register_*' functions follow
389 */
390 int plugin_register_config (const char *name,
391 int (*callback) (const char *key, const char *val),
392 const char **keys, int keys_num)
393 {
394 cf_register (name, callback, keys, keys_num);
395 return (0);
396 } /* int plugin_register_config */
398 int plugin_register_complex_config (const char *type,
399 int (*callback) (oconfig_item_t *))
400 {
401 return (cf_register_complex (type, callback));
402 } /* int plugin_register_complex_config */
404 int plugin_register_init (const char *name,
405 int (*callback) (void))
406 {
407 return (register_callback (&list_init, name, (void *) callback));
408 } /* plugin_register_init */
410 int plugin_register_read (const char *name,
411 int (*callback) (void))
412 {
413 read_func_t *rf;
415 rf = (read_func_t *) malloc (sizeof (read_func_t));
416 if (rf == NULL)
417 {
418 char errbuf[1024];
419 ERROR ("plugin_register_read: malloc failed: %s",
420 sstrerror (errno, errbuf, sizeof (errbuf)));
421 return (-1);
422 }
424 memset (rf, '\0', sizeof (read_func_t));
425 rf->wait_time = interval_g;
426 rf->wait_left = 0;
427 rf->callback = callback;
428 rf->needs_read = DONE;
430 return (register_callback (&list_read, name, (void *) rf));
431 } /* int plugin_register_read */
433 int plugin_register_write (const char *name,
434 int (*callback) (const data_set_t *ds, const value_list_t *vl))
435 {
436 return (register_callback (&list_write, name, (void *) callback));
437 } /* int plugin_register_write */
439 int plugin_register_flush (const char *name, int (*callback) (const int))
440 {
441 return (register_callback (&list_flush, name, (void *) callback));
442 } /* int plugin_register_flush */
444 int plugin_register_shutdown (char *name,
445 int (*callback) (void))
446 {
447 return (register_callback (&list_shutdown, name, (void *) callback));
448 } /* int plugin_register_shutdown */
450 int plugin_register_data_set (const data_set_t *ds)
451 {
452 data_set_t *ds_copy;
453 int i;
455 if ((data_sets != NULL)
456 && (c_avl_get (data_sets, ds->type, NULL) == 0))
457 {
458 NOTICE ("Replacing DS `%s' with another version.", ds->type);
459 plugin_unregister_data_set (ds->type);
460 }
461 else if (data_sets == NULL)
462 {
463 data_sets = c_avl_create ((int (*) (const void *, const void *)) strcmp);
464 if (data_sets == NULL)
465 return (-1);
466 }
468 ds_copy = (data_set_t *) malloc (sizeof (data_set_t));
469 if (ds_copy == NULL)
470 return (-1);
471 memcpy(ds_copy, ds, sizeof (data_set_t));
473 ds_copy->ds = (data_source_t *) malloc (sizeof (data_source_t)
474 * ds->ds_num);
475 if (ds_copy->ds == NULL)
476 {
477 free (ds_copy);
478 return (-1);
479 }
481 for (i = 0; i < ds->ds_num; i++)
482 memcpy (ds_copy->ds + i, ds->ds + i, sizeof (data_source_t));
484 return (c_avl_insert (data_sets, (void *) ds_copy->type, (void *) ds_copy));
485 } /* int plugin_register_data_set */
487 int plugin_register_log (char *name,
488 void (*callback) (int priority, const char *msg))
489 {
490 return (register_callback (&list_log, name, (void *) callback));
491 } /* int plugin_register_log */
493 int plugin_register_notification (const char *name,
494 int (*callback) (const notification_t *notif))
495 {
496 return (register_callback (&list_notification, name, (void *) callback));
497 } /* int plugin_register_log */
499 int plugin_unregister_config (const char *name)
500 {
501 cf_unregister (name);
502 return (0);
503 } /* int plugin_unregister_config */
505 int plugin_unregister_complex_config (const char *name)
506 {
507 cf_unregister_complex (name);
508 return (0);
509 } /* int plugin_unregister_complex_config */
511 int plugin_unregister_init (const char *name)
512 {
513 return (plugin_unregister (list_init, name));
514 }
516 int plugin_unregister_read (const char *name)
517 {
518 llentry_t *e;
520 e = llist_search (list_read, name);
522 if (e == NULL)
523 return (-1);
525 llist_remove (list_read, e);
526 free (e->value);
527 free (e->key);
528 llentry_destroy (e);
530 return (0);
531 }
533 int plugin_unregister_write (const char *name)
534 {
535 return (plugin_unregister (list_write, name));
536 }
538 int plugin_unregister_flush (const char *name)
539 {
540 return (plugin_unregister (list_flush, name));
541 }
543 int plugin_unregister_shutdown (const char *name)
544 {
545 return (plugin_unregister (list_shutdown, name));
546 }
548 int plugin_unregister_data_set (const char *name)
549 {
550 data_set_t *ds;
552 if (data_sets == NULL)
553 return (-1);
555 if (c_avl_remove (data_sets, name, NULL, (void *) &ds) != 0)
556 return (-1);
558 sfree (ds->ds);
559 sfree (ds);
561 return (0);
562 } /* int plugin_unregister_data_set */
564 int plugin_unregister_log (const char *name)
565 {
566 return (plugin_unregister (list_log, name));
567 }
569 int plugin_unregister_notification (const char *name)
570 {
571 return (plugin_unregister (list_notification, name));
572 }
574 void plugin_init_all (void)
575 {
576 int (*callback) (void);
577 llentry_t *le;
578 int status;
580 /* Start read-threads */
581 if (list_read != NULL)
582 {
583 const char *rt;
584 int num;
585 rt = global_option_get ("ReadThreads");
586 num = atoi (rt);
587 start_threads ((num > 0) ? num : 5);
588 }
590 /* Init the value cache */
591 uc_init ();
593 if (list_init == NULL)
594 return;
596 le = llist_head (list_init);
597 while (le != NULL)
598 {
599 callback = (int (*) (void)) le->value;
600 status = (*callback) ();
602 if (status != 0)
603 {
604 ERROR ("Initialization of plugin `%s' "
605 "failed with status %i. "
606 "Plugin will be unloaded.",
607 le->key, status);
608 /* FIXME: Unload _all_ functions */
609 plugin_unregister_read (le->key);
610 }
612 le = le->next;
613 }
614 } /* void plugin_init_all */
616 void plugin_read_all (void)
617 {
618 llentry_t *le;
619 read_func_t *rf;
621 uc_check_timeout ();
623 if (list_read == NULL)
624 return;
626 pthread_mutex_lock (&read_lock);
628 le = llist_head (list_read);
629 while (le != NULL)
630 {
631 rf = (read_func_t *) le->value;
633 if (rf->needs_read != DONE)
634 {
635 le = le->next;
636 continue;
637 }
639 if (rf->wait_left > 0)
640 rf->wait_left -= interval_g;
642 if (rf->wait_left <= 0)
643 {
644 rf->needs_read = TODO;
645 }
647 le = le->next;
648 }
650 DEBUG ("plugin: plugin_read_all: Signalling `read_cond'");
651 pthread_cond_broadcast (&read_cond);
652 pthread_mutex_unlock (&read_lock);
653 } /* void plugin_read_all */
655 int plugin_flush_one (int timeout, const char *name)
656 {
657 int (*callback) (int);
658 llentry_t *le;
659 int status;
661 if (list_flush == NULL)
662 return (-1);
664 le = llist_search (list_flush, name);
665 if (le == NULL)
666 return (-1);
667 callback = (int (*) (int)) le->value;
669 status = (*callback) (timeout);
671 return (status);
672 } /* int plugin_flush_ont */
674 void plugin_flush_all (int timeout)
675 {
676 int (*callback) (int);
677 llentry_t *le;
679 if (list_flush == NULL)
680 return;
682 le = llist_head (list_flush);
683 while (le != NULL)
684 {
685 callback = (int (*) (int)) le->value;
686 le = le->next;
688 (*callback) (timeout);
689 }
690 } /* void plugin_flush_all */
692 void plugin_shutdown_all (void)
693 {
694 int (*callback) (void);
695 llentry_t *le;
697 stop_threads ();
699 if (list_shutdown == NULL)
700 return;
702 le = llist_head (list_shutdown);
703 while (le != NULL)
704 {
705 callback = (int (*) (void)) le->value;
707 /* Advance the pointer before calling the callback allows
708 * shutdown functions to unregister themselves. If done the
709 * other way around the memory `le' points to will be freed
710 * after callback returns. */
711 le = le->next;
713 (*callback) ();
714 }
715 } /* void plugin_shutdown_all */
717 int plugin_dispatch_values (const char *name, value_list_t *vl)
718 {
719 int (*callback) (const data_set_t *, const value_list_t *);
720 data_set_t *ds;
721 llentry_t *le;
723 if ((list_write == NULL) || (data_sets == NULL))
724 return (-1);
726 if (c_avl_get (data_sets, name, (void *) &ds) != 0)
727 {
728 DEBUG ("No such dataset registered: %s", name);
729 return (-1);
730 }
732 DEBUG ("plugin: plugin_dispatch_values: time = %u; interval = %i; "
733 "host = %s; "
734 "plugin = %s; plugin_instance = %s; "
735 "type = %s; type_instance = %s;",
736 (unsigned int) vl->time, vl->interval,
737 vl->host,
738 vl->plugin, vl->plugin_instance,
739 ds->type, vl->type_instance);
741 #if COLLECT_DEBUG
742 assert (ds->ds_num == vl->values_len);
743 #else
744 if (ds->ds_num != vl->values_len)
745 {
746 ERROR ("plugin: ds->type = %s: (ds->ds_num = %i) != "
747 "(vl->values_len = %i)",
748 ds->type, ds->ds_num, vl->values_len);
749 return (-1);
750 }
751 #endif
753 escape_slashes (vl->host, sizeof (vl->host));
754 escape_slashes (vl->plugin, sizeof (vl->plugin));
755 escape_slashes (vl->plugin_instance, sizeof (vl->plugin_instance));
756 escape_slashes (vl->type_instance, sizeof (vl->type_instance));
758 /* Update the value cache */
759 uc_update (ds, vl);
760 ut_check_threshold (ds, vl);
762 le = llist_head (list_write);
763 while (le != NULL)
764 {
765 callback = (int (*) (const data_set_t *, const value_list_t *)) le->value;
766 (*callback) (ds, vl);
768 le = le->next;
769 }
771 return (0);
772 } /* int plugin_dispatch_values */
774 int plugin_dispatch_notification (const notification_t *notif)
775 {
776 int (*callback) (const notification_t *);
777 llentry_t *le;
778 /* Possible TODO: Add flap detection here */
780 DEBUG ("plugin_dispatch_notification: severity = %i; message = %s; "
781 "time = %u; host = %s;",
782 notif->severity, notif->message,
783 (unsigned int) notif->time, notif->host);
785 /* Nobody cares for notifications */
786 if (list_notification == NULL)
787 return (-1);
789 le = llist_head (list_notification);
790 while (le != NULL)
791 {
792 callback = (int (*) (const notification_t *)) le->value;
793 (*callback) (notif);
795 le = le->next;
796 }
798 return (0);
799 } /* int plugin_dispatch_notification */
801 void plugin_log (int level, const char *format, ...)
802 {
803 char msg[512];
804 va_list ap;
806 void (*callback) (int, const char *);
807 llentry_t *le;
809 if (list_log == NULL)
810 return;
812 #if !COLLECT_DEBUG
813 if (level >= LOG_DEBUG)
814 return;
815 #endif
817 va_start (ap, format);
818 vsnprintf (msg, 512, format, ap);
819 msg[511] = '\0';
820 va_end (ap);
822 le = llist_head (list_log);
823 while (le != NULL)
824 {
825 callback = (void (*) (int, const char *)) le->value;
826 (*callback) (level, msg);
828 le = le->next;
829 }
830 } /* void plugin_log */
832 const data_set_t *plugin_get_ds (const char *name)
833 {
834 data_set_t *ds;
836 if (c_avl_get (data_sets, name, (void *) &ds) != 0)
837 {
838 DEBUG ("No such dataset registered: %s", name);
839 return (NULL);
840 }
842 return (ds);
843 } /* data_set_t *plugin_get_ds */