8844c3397fd333a79f7959b6a81fd77ae42a1b26
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"
24 #include "utils_complain.h"
26 #include <ltdl.h>
28 #if HAVE_PTHREAD_H
29 # include <pthread.h>
30 #endif
32 #include "common.h"
33 #include "plugin.h"
34 #include "configfile.h"
35 #include "utils_avltree.h"
36 #include "utils_llist.h"
37 #include "utils_cache.h"
38 #include "utils_threshold.h"
40 /*
41 * Private structures
42 */
43 struct read_func_s
44 {
45 int wait_time;
46 int wait_left;
47 int (*callback) (void);
48 enum { DONE = 0, TODO = 1, ACTIVE = 2 } needs_read;
49 };
50 typedef struct read_func_s read_func_t;
52 /*
53 * Private variables
54 */
55 static llist_t *list_init;
56 static llist_t *list_read;
57 static llist_t *list_write;
58 static llist_t *list_flush;
59 static llist_t *list_shutdown;
60 static llist_t *list_log;
61 static llist_t *list_notification;
63 static c_avl_tree_t *data_sets;
65 static char *plugindir = NULL;
67 static int read_loop = 1;
68 static pthread_mutex_t read_lock = PTHREAD_MUTEX_INITIALIZER;
69 static pthread_cond_t read_cond = PTHREAD_COND_INITIALIZER;
70 static pthread_t *read_threads = NULL;
71 static int read_threads_num = 0;
73 /*
74 * Static functions
75 */
76 static const char *plugin_get_dir (void)
77 {
78 if (plugindir == NULL)
79 return (PLUGINDIR);
80 else
81 return (plugindir);
82 }
84 static int register_callback (llist_t **list, const char *name, void *callback)
85 {
86 llentry_t *le;
87 char *key;
89 if ((*list == NULL)
90 && ((*list = llist_create ()) == NULL))
91 return (-1);
93 le = llist_search (*list, name);
94 if (le == NULL)
95 {
96 key = strdup (name);
97 if (key == NULL)
98 return (-1);
100 le = llentry_create (key, callback);
101 if (le == NULL)
102 {
103 free (key);
104 return (-1);
105 }
107 llist_append (*list, le);
108 }
109 else
110 {
111 le->value = callback;
112 }
114 return (0);
115 } /* int register_callback */
117 static int plugin_unregister (llist_t *list, const char *name)
118 {
119 llentry_t *e;
121 e = llist_search (list, name);
123 if (e == NULL)
124 return (-1);
126 llist_remove (list, e);
127 free (e->key);
128 llentry_destroy (e);
130 return (0);
131 } /* int plugin_unregister */
133 /*
134 * (Try to) load the shared object `file'. Won't complain if it isn't a shared
135 * object, but it will bitch about a shared object not having a
136 * ``module_register'' symbol..
137 */
138 static int plugin_load_file (char *file)
139 {
140 lt_dlhandle dlh;
141 void (*reg_handle) (void);
143 DEBUG ("file = %s", file);
145 lt_dlinit ();
146 lt_dlerror (); /* clear errors */
148 if ((dlh = lt_dlopen (file)) == NULL)
149 {
150 const char *error = lt_dlerror ();
152 ERROR ("lt_dlopen failed: %s", error);
153 fprintf (stderr, "lt_dlopen failed: %s\n", error);
154 return (1);
155 }
157 if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
158 {
159 WARNING ("Couldn't find symbol ``module_register'' in ``%s'': %s\n",
160 file, lt_dlerror ());
161 lt_dlclose (dlh);
162 return (-1);
163 }
165 (*reg_handle) ();
167 return (0);
168 }
170 static void *plugin_read_thread (void *args)
171 {
172 llentry_t *le;
173 read_func_t *rf;
174 int status;
175 int done;
177 pthread_mutex_lock (&read_lock);
179 while (read_loop != 0)
180 {
181 le = llist_head (list_read);
182 done = 0;
184 while ((read_loop != 0) && (le != NULL))
185 {
186 rf = (read_func_t *) le->value;
188 if (rf->needs_read != TODO)
189 {
190 le = le->next;
191 continue;
192 }
194 /* We will do this read function */
195 rf->needs_read = ACTIVE;
197 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Handling %s",
198 (unsigned long int) pthread_self (), le->key);
199 pthread_mutex_unlock (&read_lock);
201 status = rf->callback ();
202 done++;
204 if (status != 0)
205 {
206 if (rf->wait_time < interval_g)
207 rf->wait_time = interval_g;
208 rf->wait_left = rf->wait_time;
209 rf->wait_time = rf->wait_time * 2;
210 if (rf->wait_time > 86400)
211 rf->wait_time = 86400;
213 NOTICE ("read-function of plugin `%s' "
214 "failed. Will suspend it for %i "
215 "seconds.", le->key, rf->wait_left);
216 }
217 else
218 {
219 rf->wait_left = 0;
220 rf->wait_time = interval_g;
221 }
223 pthread_mutex_lock (&read_lock);
225 rf->needs_read = DONE;
226 le = le->next;
227 } /* while (le != NULL) */
229 if ((read_loop != 0) && (done == 0))
230 {
231 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Waiting on read_cond.",
232 (unsigned long int) pthread_self ());
233 pthread_cond_wait (&read_cond, &read_lock);
234 }
235 } /* while (read_loop) */
237 pthread_mutex_unlock (&read_lock);
239 pthread_exit (NULL);
240 return ((void *) 0);
241 } /* void *plugin_read_thread */
243 static void start_threads (int num)
244 {
245 int i;
247 if (read_threads != NULL)
248 return;
250 read_threads = (pthread_t *) calloc (num, sizeof (pthread_t));
251 if (read_threads == NULL)
252 {
253 ERROR ("plugin: start_threads: calloc failed.");
254 return;
255 }
257 read_threads_num = 0;
258 for (i = 0; i < num; i++)
259 {
260 if (pthread_create (read_threads + read_threads_num, NULL,
261 plugin_read_thread, NULL) == 0)
262 {
263 read_threads_num++;
264 }
265 else
266 {
267 ERROR ("plugin: start_threads: pthread_create failed.");
268 return;
269 }
270 } /* for (i) */
271 } /* void start_threads */
273 static void stop_threads (void)
274 {
275 int i;
277 pthread_mutex_lock (&read_lock);
278 read_loop = 0;
279 DEBUG ("plugin: stop_threads: Signalling `read_cond'");
280 pthread_cond_broadcast (&read_cond);
281 pthread_mutex_unlock (&read_lock);
283 for (i = 0; i < read_threads_num; i++)
284 {
285 if (pthread_join (read_threads[i], NULL) != 0)
286 {
287 ERROR ("plugin: stop_threads: pthread_join failed.");
288 }
289 read_threads[i] = (pthread_t) 0;
290 }
291 sfree (read_threads);
292 read_threads_num = 0;
293 } /* void stop_threads */
295 /*
296 * Public functions
297 */
298 void plugin_set_dir (const char *dir)
299 {
300 if (plugindir != NULL)
301 free (plugindir);
303 if (dir == NULL)
304 plugindir = NULL;
305 else if ((plugindir = strdup (dir)) == NULL)
306 {
307 char errbuf[1024];
308 ERROR ("strdup failed: %s",
309 sstrerror (errno, errbuf, sizeof (errbuf)));
310 }
311 }
313 #define BUFSIZE 512
314 int plugin_load (const char *type)
315 {
316 DIR *dh;
317 const char *dir;
318 char filename[BUFSIZE] = "";
319 char typename[BUFSIZE];
320 int typename_len;
321 int ret;
322 struct stat statbuf;
323 struct dirent *de;
325 DEBUG ("type = %s", type);
327 dir = plugin_get_dir ();
328 ret = 1;
330 /* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
331 * type when matching the filename */
332 if (ssnprintf (typename, sizeof (typename),
333 "%s.so", type) >= sizeof (typename))
334 {
335 WARNING ("snprintf: truncated: `%s.so'", type);
336 return (-1);
337 }
338 typename_len = strlen (typename);
340 if ((dh = opendir (dir)) == NULL)
341 {
342 char errbuf[1024];
343 ERROR ("opendir (%s): %s", dir,
344 sstrerror (errno, errbuf, sizeof (errbuf)));
345 return (-1);
346 }
348 while ((de = readdir (dh)) != NULL)
349 {
350 if (strncasecmp (de->d_name, typename, typename_len))
351 continue;
353 if (ssnprintf (filename, sizeof (filename),
354 "%s/%s", dir, de->d_name) >= sizeof (filename))
355 {
356 WARNING ("snprintf: truncated: `%s/%s'", dir, de->d_name);
357 continue;
358 }
360 if (lstat (filename, &statbuf) == -1)
361 {
362 char errbuf[1024];
363 WARNING ("stat %s: %s", filename,
364 sstrerror (errno, errbuf, sizeof (errbuf)));
365 continue;
366 }
367 else if (!S_ISREG (statbuf.st_mode))
368 {
369 /* don't follow symlinks */
370 continue;
371 }
373 if (plugin_load_file (filename) == 0)
374 {
375 /* success */
376 ret = 0;
377 break;
378 }
379 else
380 {
381 fprintf (stderr, "Unable to load plugin %s.\n", type);
382 }
383 }
385 closedir (dh);
387 if (filename[0] == '\0')
388 fprintf (stderr, "Could not find plugin %s.\n", type);
390 return (ret);
391 }
393 /*
394 * The `register_*' functions follow
395 */
396 int plugin_register_config (const char *name,
397 int (*callback) (const char *key, const char *val),
398 const char **keys, int keys_num)
399 {
400 cf_register (name, callback, keys, keys_num);
401 return (0);
402 } /* int plugin_register_config */
404 int plugin_register_complex_config (const char *type,
405 int (*callback) (oconfig_item_t *))
406 {
407 return (cf_register_complex (type, callback));
408 } /* int plugin_register_complex_config */
410 int plugin_register_init (const char *name,
411 int (*callback) (void))
412 {
413 return (register_callback (&list_init, name, (void *) callback));
414 } /* plugin_register_init */
416 int plugin_register_read (const char *name,
417 int (*callback) (void))
418 {
419 read_func_t *rf;
421 rf = (read_func_t *) malloc (sizeof (read_func_t));
422 if (rf == NULL)
423 {
424 char errbuf[1024];
425 ERROR ("plugin_register_read: malloc failed: %s",
426 sstrerror (errno, errbuf, sizeof (errbuf)));
427 return (-1);
428 }
430 memset (rf, '\0', sizeof (read_func_t));
431 rf->wait_time = interval_g;
432 rf->wait_left = 0;
433 rf->callback = callback;
434 rf->needs_read = DONE;
436 return (register_callback (&list_read, name, (void *) rf));
437 } /* int plugin_register_read */
439 int plugin_register_write (const char *name,
440 int (*callback) (const data_set_t *ds, const value_list_t *vl))
441 {
442 return (register_callback (&list_write, name, (void *) callback));
443 } /* int plugin_register_write */
445 int plugin_register_flush (const char *name,
446 int (*callback) (const int timeout, const char *identifier))
447 {
448 return (register_callback (&list_flush, name, (void *) callback));
449 } /* int plugin_register_flush */
451 int plugin_register_shutdown (char *name,
452 int (*callback) (void))
453 {
454 return (register_callback (&list_shutdown, name, (void *) callback));
455 } /* int plugin_register_shutdown */
457 int plugin_register_data_set (const data_set_t *ds)
458 {
459 data_set_t *ds_copy;
460 int i;
462 if ((data_sets != NULL)
463 && (c_avl_get (data_sets, ds->type, NULL) == 0))
464 {
465 NOTICE ("Replacing DS `%s' with another version.", ds->type);
466 plugin_unregister_data_set (ds->type);
467 }
468 else if (data_sets == NULL)
469 {
470 data_sets = c_avl_create ((int (*) (const void *, const void *)) strcmp);
471 if (data_sets == NULL)
472 return (-1);
473 }
475 ds_copy = (data_set_t *) malloc (sizeof (data_set_t));
476 if (ds_copy == NULL)
477 return (-1);
478 memcpy(ds_copy, ds, sizeof (data_set_t));
480 ds_copy->ds = (data_source_t *) malloc (sizeof (data_source_t)
481 * ds->ds_num);
482 if (ds_copy->ds == NULL)
483 {
484 free (ds_copy);
485 return (-1);
486 }
488 for (i = 0; i < ds->ds_num; i++)
489 memcpy (ds_copy->ds + i, ds->ds + i, sizeof (data_source_t));
491 return (c_avl_insert (data_sets, (void *) ds_copy->type, (void *) ds_copy));
492 } /* int plugin_register_data_set */
494 int plugin_register_log (char *name,
495 void (*callback) (int priority, const char *msg))
496 {
497 return (register_callback (&list_log, name, (void *) callback));
498 } /* int plugin_register_log */
500 int plugin_register_notification (const char *name,
501 int (*callback) (const notification_t *notif))
502 {
503 return (register_callback (&list_notification, name, (void *) callback));
504 } /* int plugin_register_log */
506 int plugin_unregister_config (const char *name)
507 {
508 cf_unregister (name);
509 return (0);
510 } /* int plugin_unregister_config */
512 int plugin_unregister_complex_config (const char *name)
513 {
514 cf_unregister_complex (name);
515 return (0);
516 } /* int plugin_unregister_complex_config */
518 int plugin_unregister_init (const char *name)
519 {
520 return (plugin_unregister (list_init, name));
521 }
523 int plugin_unregister_read (const char *name)
524 {
525 llentry_t *e;
527 e = llist_search (list_read, name);
529 if (e == NULL)
530 return (-1);
532 llist_remove (list_read, e);
533 free (e->value);
534 free (e->key);
535 llentry_destroy (e);
537 return (0);
538 }
540 int plugin_unregister_write (const char *name)
541 {
542 return (plugin_unregister (list_write, name));
543 }
545 int plugin_unregister_flush (const char *name)
546 {
547 return (plugin_unregister (list_flush, name));
548 }
550 int plugin_unregister_shutdown (const char *name)
551 {
552 return (plugin_unregister (list_shutdown, name));
553 }
555 int plugin_unregister_data_set (const char *name)
556 {
557 data_set_t *ds;
559 if (data_sets == NULL)
560 return (-1);
562 if (c_avl_remove (data_sets, name, NULL, (void *) &ds) != 0)
563 return (-1);
565 sfree (ds->ds);
566 sfree (ds);
568 return (0);
569 } /* int plugin_unregister_data_set */
571 int plugin_unregister_log (const char *name)
572 {
573 return (plugin_unregister (list_log, name));
574 }
576 int plugin_unregister_notification (const char *name)
577 {
578 return (plugin_unregister (list_notification, name));
579 }
581 void plugin_init_all (void)
582 {
583 int (*callback) (void);
584 llentry_t *le;
585 int status;
587 /* Start read-threads */
588 if (list_read != NULL)
589 {
590 const char *rt;
591 int num;
592 rt = global_option_get ("ReadThreads");
593 num = atoi (rt);
594 start_threads ((num > 0) ? num : 5);
595 }
597 /* Init the value cache */
598 uc_init ();
600 if (list_init == NULL)
601 return;
603 le = llist_head (list_init);
604 while (le != NULL)
605 {
606 callback = (int (*) (void)) le->value;
607 status = (*callback) ();
609 if (status != 0)
610 {
611 ERROR ("Initialization of plugin `%s' "
612 "failed with status %i. "
613 "Plugin will be unloaded.",
614 le->key, status);
615 /* FIXME: Unload _all_ functions */
616 plugin_unregister_read (le->key);
617 }
619 le = le->next;
620 }
621 } /* void plugin_init_all */
623 void plugin_read_all (void)
624 {
625 llentry_t *le;
626 read_func_t *rf;
628 uc_check_timeout ();
630 if (list_read == NULL)
631 return;
633 pthread_mutex_lock (&read_lock);
635 le = llist_head (list_read);
636 while (le != NULL)
637 {
638 rf = (read_func_t *) le->value;
640 if (rf->needs_read != DONE)
641 {
642 le = le->next;
643 continue;
644 }
646 if (rf->wait_left > 0)
647 rf->wait_left -= interval_g;
649 if (rf->wait_left <= 0)
650 {
651 rf->needs_read = TODO;
652 }
654 le = le->next;
655 }
657 DEBUG ("plugin: plugin_read_all: Signalling `read_cond'");
658 pthread_cond_broadcast (&read_cond);
659 pthread_mutex_unlock (&read_lock);
660 } /* void plugin_read_all */
662 int plugin_flush_one (int timeout, const char *name)
663 {
664 int (*callback) (int);
665 llentry_t *le;
666 int status;
668 if (list_flush == NULL)
669 return (-1);
671 le = llist_search (list_flush, name);
672 if (le == NULL)
673 return (-1);
674 callback = (int (*) (int)) le->value;
676 status = (*callback) (timeout);
678 return (status);
679 } /* int plugin_flush_ont */
681 void plugin_flush_all (int timeout)
682 {
683 int (*callback) (int);
684 llentry_t *le;
686 if (list_flush == NULL)
687 return;
689 le = llist_head (list_flush);
690 while (le != NULL)
691 {
692 callback = (int (*) (int)) le->value;
693 le = le->next;
695 (*callback) (timeout);
696 }
697 } /* void plugin_flush_all */
699 int plugin_flush (const char *plugin, int timeout, const char *identifier)
700 {
701 int (*callback) (int timeout, const char *identifier);
702 llentry_t *le;
704 if (list_flush == NULL)
705 return (0);
707 le = llist_head (list_flush);
708 while (le != NULL)
709 {
710 if ((plugin != NULL)
711 && (strcmp (plugin, le->key) != 0))
712 continue;
714 callback = (int (*) (int, const char *)) le->value;
715 le = le->next;
717 (*callback) (timeout, identifier);
718 }
719 } /* int plugin_flush */
721 void plugin_shutdown_all (void)
722 {
723 int (*callback) (void);
724 llentry_t *le;
726 stop_threads ();
728 if (list_shutdown == NULL)
729 return;
731 le = llist_head (list_shutdown);
732 while (le != NULL)
733 {
734 callback = (int (*) (void)) le->value;
736 /* Advance the pointer before calling the callback allows
737 * shutdown functions to unregister themselves. If done the
738 * other way around the memory `le' points to will be freed
739 * after callback returns. */
740 le = le->next;
742 (*callback) ();
743 }
744 } /* void plugin_shutdown_all */
746 int plugin_dispatch_values (value_list_t *vl)
747 {
748 static c_complain_t no_write_complaint = C_COMPLAIN_INIT;
750 int (*callback) (const data_set_t *, const value_list_t *);
751 data_set_t *ds;
752 llentry_t *le;
754 if ((vl == NULL) || (*vl->type == '\0')) {
755 ERROR ("plugin_dispatch_values: Invalid value list.");
756 return (-1);
757 }
759 if (list_write == NULL)
760 c_complain_once (LOG_WARNING, &no_write_complaint,
761 "plugin_dispatch_values: No write callback has been "
762 "registered. Please load at least one output plugin, "
763 "if you want the collected data to be stored.");
765 if (data_sets == NULL)
766 {
767 ERROR ("plugin_dispatch_values: No data sets registered. "
768 "Could the types database be read? Check "
769 "your `TypesDB' setting!");
770 return (-1);
771 }
773 if (c_avl_get (data_sets, vl->type, (void *) &ds) != 0)
774 {
775 INFO ("plugin_dispatch_values: Dataset not found: %s", vl->type);
776 return (-1);
777 }
779 DEBUG ("plugin_dispatch_values: time = %u; interval = %i; "
780 "host = %s; "
781 "plugin = %s; plugin_instance = %s; "
782 "type = %s; type_instance = %s;",
783 (unsigned int) vl->time, vl->interval,
784 vl->host,
785 vl->plugin, vl->plugin_instance,
786 vl->type, vl->type_instance);
788 #if COLLECT_DEBUG
789 assert (0 == strcmp (ds->type, vl->type));
790 #else
791 if (0 != strcmp (ds->type, vl->type))
792 WARNING ("plugin_dispatch_values: (ds->type = %s) != (vl->type = %s)",
793 ds->type, vl->type);
794 #endif
796 #if COLLECT_DEBUG
797 assert (ds->ds_num == vl->values_len);
798 #else
799 if (ds->ds_num != vl->values_len)
800 {
801 ERROR ("plugin_dispatch_values: ds->type = %s: "
802 "(ds->ds_num = %i) != "
803 "(vl->values_len = %i)",
804 ds->type, ds->ds_num, vl->values_len);
805 return (-1);
806 }
807 #endif
809 escape_slashes (vl->host, sizeof (vl->host));
810 escape_slashes (vl->plugin, sizeof (vl->plugin));
811 escape_slashes (vl->plugin_instance, sizeof (vl->plugin_instance));
812 escape_slashes (vl->type, sizeof (vl->type));
813 escape_slashes (vl->type_instance, sizeof (vl->type_instance));
815 /* Update the value cache */
816 uc_update (ds, vl);
817 ut_check_threshold (ds, vl);
819 le = llist_head (list_write);
820 while (le != NULL)
821 {
822 callback = (int (*) (const data_set_t *, const value_list_t *)) le->value;
823 (*callback) (ds, vl);
825 le = le->next;
826 }
828 return (0);
829 } /* int plugin_dispatch_values */
831 int plugin_dispatch_notification (const notification_t *notif)
832 {
833 int (*callback) (const notification_t *);
834 llentry_t *le;
835 /* Possible TODO: Add flap detection here */
837 DEBUG ("plugin_dispatch_notification: severity = %i; message = %s; "
838 "time = %u; host = %s;",
839 notif->severity, notif->message,
840 (unsigned int) notif->time, notif->host);
842 /* Nobody cares for notifications */
843 if (list_notification == NULL)
844 return (-1);
846 le = llist_head (list_notification);
847 while (le != NULL)
848 {
849 callback = (int (*) (const notification_t *)) le->value;
850 (*callback) (notif);
852 le = le->next;
853 }
855 return (0);
856 } /* int plugin_dispatch_notification */
858 void plugin_log (int level, const char *format, ...)
859 {
860 char msg[512];
861 va_list ap;
863 void (*callback) (int, const char *);
864 llentry_t *le;
866 if (list_log == NULL)
867 return;
869 #if !COLLECT_DEBUG
870 if (level >= LOG_DEBUG)
871 return;
872 #endif
874 va_start (ap, format);
875 vsnprintf (msg, 512, format, ap);
876 msg[511] = '\0';
877 va_end (ap);
879 le = llist_head (list_log);
880 while (le != NULL)
881 {
882 callback = (void (*) (int, const char *)) le->value;
883 (*callback) (level, msg);
885 le = le->next;
886 }
887 } /* void plugin_log */
889 const data_set_t *plugin_get_ds (const char *name)
890 {
891 data_set_t *ds;
893 if (c_avl_get (data_sets, name, (void *) &ds) != 0)
894 {
895 DEBUG ("No such dataset registered: %s", name);
896 return (NULL);
897 }
899 return (ds);
900 } /* data_set_t *plugin_get_ds */