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_llist.h"
35 /*
36 * Private structures
37 */
38 struct read_func_s
39 {
40 int wait_time;
41 int wait_left;
42 int (*callback) (void);
43 enum { DONE = 0, TODO = 1, ACTIVE = 2 } needs_read;
44 };
45 typedef struct read_func_s read_func_t;
47 /*
48 * Private variables
49 */
50 static llist_t *list_init;
51 static llist_t *list_read;
52 static llist_t *list_write;
53 static llist_t *list_shutdown;
54 static llist_t *list_data_set;
55 static llist_t *list_log;
57 static char *plugindir = NULL;
59 static int read_loop = 1;
60 static pthread_mutex_t read_lock = PTHREAD_MUTEX_INITIALIZER;
61 static pthread_cond_t read_cond = PTHREAD_COND_INITIALIZER;
62 static pthread_t *read_threads = NULL;
63 static int read_threads_num = 0;
65 /*
66 * Static functions
67 */
68 static const char *plugin_get_dir (void)
69 {
70 if (plugindir == NULL)
71 return (PLUGINDIR);
72 else
73 return (plugindir);
74 }
76 static int register_callback (llist_t **list, const char *name, void *callback)
77 {
78 llentry_t *le;
80 if ((*list == NULL)
81 && ((*list = llist_create ()) == NULL))
82 return (-1);
84 le = llist_search (*list, name);
85 if (le == NULL)
86 {
87 le = llentry_create (name, callback);
88 if (le == NULL)
89 return (-1);
91 llist_append (*list, le);
92 }
93 else
94 {
95 le->value = callback;
96 }
98 return (0);
99 } /* int register_callback */
101 static int plugin_unregister (llist_t *list, const char *name)
102 {
103 llentry_t *e;
105 e = llist_search (list, name);
107 if (e == NULL)
108 return (-1);
110 llist_remove (list, e);
111 llentry_destroy (e);
113 return (0);
114 } /* int plugin_unregister */
116 /*
117 * (Try to) load the shared object `file'. Won't complain if it isn't a shared
118 * object, but it will bitch about a shared object not having a
119 * ``module_register'' symbol..
120 */
121 static int plugin_load_file (char *file)
122 {
123 lt_dlhandle dlh;
124 void (*reg_handle) (void);
126 DEBUG ("file = %s", file);
128 lt_dlinit ();
129 lt_dlerror (); /* clear errors */
131 if ((dlh = lt_dlopen (file)) == NULL)
132 {
133 const char *error = lt_dlerror ();
135 ERROR ("lt_dlopen failed: %s", error);
136 return (1);
137 }
139 if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
140 {
141 WARNING ("Couldn't find symbol ``module_register'' in ``%s'': %s\n",
142 file, lt_dlerror ());
143 lt_dlclose (dlh);
144 return (-1);
145 }
147 (*reg_handle) ();
149 return (0);
150 }
152 static void *plugin_read_thread (void *args)
153 {
154 llentry_t *le;
155 read_func_t *rf;
156 int status;
157 int done;
159 pthread_mutex_lock (&read_lock);
161 while (read_loop != 0)
162 {
163 le = llist_head (list_read);
164 done = 0;
166 while ((read_loop != 0) && (le != NULL))
167 {
168 rf = (read_func_t *) le->value;
170 if (rf->needs_read != TODO)
171 {
172 le = le->next;
173 continue;
174 }
176 /* We will do this read function */
177 rf->needs_read = ACTIVE;
179 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Handling %s",
180 (unsigned long int) pthread_self (), le->key);
181 pthread_mutex_unlock (&read_lock);
183 status = rf->callback ();
184 done++;
186 if (status != 0)
187 {
188 if (rf->wait_time < interval_g)
189 rf->wait_time = interval_g;
190 rf->wait_left = rf->wait_time;
191 rf->wait_time = rf->wait_time * 2;
192 if (rf->wait_time > 86400)
193 rf->wait_time = 86400;
195 NOTICE ("read-function of plugin `%s' "
196 "failed. Will suspend it for %i "
197 "seconds.", le->key, rf->wait_left);
198 }
199 else
200 {
201 rf->wait_left = 0;
202 rf->wait_time = interval_g;
203 }
205 pthread_mutex_lock (&read_lock);
207 rf->needs_read = DONE;
208 le = le->next;
209 } /* while (le != NULL) */
211 if ((read_loop != 0) && (done == 0))
212 {
213 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Waiting on read_cond.",
214 (unsigned long int) pthread_self ());
215 pthread_cond_wait (&read_cond, &read_lock);
216 }
217 } /* while (read_loop) */
219 pthread_mutex_unlock (&read_lock);
221 pthread_exit (NULL);
222 } /* void *plugin_read_thread */
224 static void start_threads (int num)
225 {
226 int i;
228 if (read_threads != NULL)
229 return;
231 read_threads = (pthread_t *) calloc (num, sizeof (pthread_t));
232 if (read_threads == NULL)
233 {
234 ERROR ("plugin: start_threads: calloc failed.");
235 return;
236 }
238 read_threads_num = 0;
239 for (i = 0; i < num; i++)
240 {
241 if (pthread_create (read_threads + read_threads_num, NULL,
242 plugin_read_thread, NULL) == 0)
243 {
244 read_threads_num++;
245 }
246 else
247 {
248 ERROR ("plugin: start_threads: pthread_create failed.");
249 return;
250 }
251 } /* for (i) */
252 } /* void start_threads */
254 static void stop_threads (void)
255 {
256 int i;
258 pthread_mutex_lock (&read_lock);
259 read_loop = 0;
260 DEBUG ("plugin: stop_threads: Signalling `read_cond'");
261 pthread_cond_broadcast (&read_cond);
262 pthread_mutex_unlock (&read_lock);
264 for (i = 0; i < read_threads_num; i++)
265 {
266 if (pthread_join (read_threads[i], NULL) != 0)
267 {
268 ERROR ("plugin: stop_threads: pthread_join failed.");
269 }
270 read_threads[i] = (pthread_t) 0;
271 }
272 sfree (read_threads);
273 read_threads_num = 0;
274 } /* void stop_threads */
276 /*
277 * Public functions
278 */
279 void plugin_set_dir (const char *dir)
280 {
281 if (plugindir != NULL)
282 free (plugindir);
284 if (dir == NULL)
285 plugindir = NULL;
286 else if ((plugindir = strdup (dir)) == NULL)
287 {
288 char errbuf[1024];
289 ERROR ("strdup failed: %s",
290 sstrerror (errno, errbuf, sizeof (errbuf)));
291 }
292 }
294 #define BUFSIZE 512
295 int plugin_load (const char *type)
296 {
297 DIR *dh;
298 const char *dir;
299 char filename[BUFSIZE];
300 char typename[BUFSIZE];
301 int typename_len;
302 int ret;
303 struct stat statbuf;
304 struct dirent *de;
306 DEBUG ("type = %s", type);
308 dir = plugin_get_dir ();
309 ret = 1;
311 /* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
312 * type when matching the filename */
313 if (snprintf (typename, BUFSIZE, "%s.so", type) >= BUFSIZE)
314 {
315 WARNING ("snprintf: truncated: `%s.so'", type);
316 return (-1);
317 }
318 typename_len = strlen (typename);
320 if ((dh = opendir (dir)) == NULL)
321 {
322 char errbuf[1024];
323 ERROR ("opendir (%s): %s", dir,
324 sstrerror (errno, errbuf, sizeof (errbuf)));
325 return (-1);
326 }
328 while ((de = readdir (dh)) != NULL)
329 {
330 if (strncasecmp (de->d_name, typename, typename_len))
331 continue;
333 if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
334 {
335 WARNING ("snprintf: truncated: `%s/%s'", dir, de->d_name);
336 continue;
337 }
339 if (lstat (filename, &statbuf) == -1)
340 {
341 char errbuf[1024];
342 WARNING ("stat %s: %s", filename,
343 sstrerror (errno, errbuf, sizeof (errbuf)));
344 continue;
345 }
346 else if (!S_ISREG (statbuf.st_mode))
347 {
348 /* don't follow symlinks */
349 continue;
350 }
352 if (plugin_load_file (filename) == 0)
353 {
354 /* success */
355 ret = 0;
356 break;
357 }
358 }
360 closedir (dh);
362 return (ret);
363 }
365 /*
366 * The `register_*' functions follow
367 */
368 int plugin_register_config (const char *name,
369 int (*callback) (const char *key, const char *val),
370 const char **keys, int keys_num)
371 {
372 cf_register (name, callback, keys, keys_num);
373 return (0);
374 } /* int plugin_register_config */
376 int plugin_register_complex_config (const char *type,
377 int (*callback) (oconfig_item_t *))
378 {
379 return (cf_register_complex (type, callback));
380 } /* int plugin_register_complex_config */
382 int plugin_register_init (const char *name,
383 int (*callback) (void))
384 {
385 return (register_callback (&list_init, name, (void *) callback));
386 } /* plugin_register_init */
388 int plugin_register_read (const char *name,
389 int (*callback) (void))
390 {
391 read_func_t *rf;
393 rf = (read_func_t *) malloc (sizeof (read_func_t));
394 if (rf == NULL)
395 {
396 char errbuf[1024];
397 ERROR ("plugin_register_read: malloc failed: %s",
398 sstrerror (errno, errbuf, sizeof (errbuf)));
399 return (-1);
400 }
402 memset (rf, '\0', sizeof (read_func_t));
403 rf->wait_time = interval_g;
404 rf->wait_left = 0;
405 rf->callback = callback;
406 rf->needs_read = DONE;
408 return (register_callback (&list_read, name, (void *) rf));
409 } /* int plugin_register_read */
411 int plugin_register_write (const char *name,
412 int (*callback) (const data_set_t *ds, const value_list_t *vl))
413 {
414 return (register_callback (&list_write, name, (void *) callback));
415 } /* int plugin_register_write */
417 int plugin_register_shutdown (char *name,
418 int (*callback) (void))
419 {
420 return (register_callback (&list_shutdown, name, (void *) callback));
421 } /* int plugin_register_shutdown */
423 int plugin_register_data_set (const data_set_t *ds)
424 {
425 data_set_t *ds_copy;
426 int i;
428 if ((list_data_set != NULL)
429 && (llist_search (list_data_set, ds->type) != NULL))
430 {
431 NOTICE ("Replacing DS `%s' with another version.", ds->type);
432 plugin_unregister_data_set (ds->type);
433 }
435 ds_copy = (data_set_t *) malloc (sizeof (data_set_t));
436 if (ds_copy == NULL)
437 return (-1);
438 memcpy(ds_copy, ds, sizeof (data_set_t));
440 ds_copy->ds = (data_source_t *) malloc (sizeof (data_source_t)
441 * ds->ds_num);
442 if (ds_copy->ds == NULL)
443 {
444 free (ds_copy);
445 return (-1);
446 }
448 for (i = 0; i < ds->ds_num; i++)
449 memcpy (ds_copy->ds + i, ds->ds + i, sizeof (data_source_t));
451 return (register_callback (&list_data_set, ds->type, (void *) ds_copy));
452 } /* int plugin_register_data_set */
454 int plugin_register_log (char *name,
455 void (*callback) (int priority, const char *msg))
456 {
457 return (register_callback (&list_log, name, (void *) callback));
458 } /* int plugin_register_log */
460 int plugin_unregister_config (const char *name)
461 {
462 cf_unregister (name);
463 return (0);
464 } /* int plugin_unregister_config */
466 int plugin_unregister_complex_config (const char *name)
467 {
468 cf_unregister_complex (name);
469 return (0);
470 } /* int plugin_unregister_complex_config */
472 int plugin_unregister_init (const char *name)
473 {
474 return (plugin_unregister (list_init, name));
475 }
477 int plugin_unregister_read (const char *name)
478 {
479 llentry_t *e;
481 e = llist_search (list_read, name);
483 if (e == NULL)
484 return (-1);
486 llist_remove (list_read, e);
487 free (e->value);
488 llentry_destroy (e);
490 return (0);
491 }
493 int plugin_unregister_write (const char *name)
494 {
495 return (plugin_unregister (list_write, name));
496 }
498 int plugin_unregister_shutdown (const char *name)
499 {
500 return (plugin_unregister (list_shutdown, name));
501 }
503 int plugin_unregister_data_set (const char *name)
504 {
505 llentry_t *e;
506 data_set_t *ds;
508 if (list_data_set == NULL)
509 return (-1);
511 e = llist_search (list_data_set, name);
513 if (e == NULL)
514 return (-1);
516 llist_remove (list_data_set, e);
517 ds = (data_set_t *) e->value;
518 llentry_destroy (e);
520 sfree (ds->ds);
521 sfree (ds);
523 return (0);
524 } /* int plugin_unregister_data_set */
526 int plugin_unregister_log (const char *name)
527 {
528 return (plugin_unregister (list_log, name));
529 }
531 void plugin_init_all (void)
532 {
533 int (*callback) (void);
534 llentry_t *le;
535 int status;
537 /* Start read-threads */
538 if (list_read != NULL)
539 {
540 const char *rt;
541 int num;
542 rt = global_option_get ("ReadThreads");
543 num = atoi (rt);
544 start_threads ((num > 0) ? num : 5);
545 }
547 if (list_init == NULL)
548 return;
550 le = llist_head (list_init);
551 while (le != NULL)
552 {
553 callback = (int (*) (void)) le->value;
554 status = (*callback) ();
556 if (status != 0)
557 {
558 ERROR ("Initialization of plugin `%s' "
559 "failed with status %i. "
560 "Plugin will be unloaded.",
561 le->key, status);
562 /* FIXME: Unload _all_ functions */
563 plugin_unregister_read (le->key);
564 }
566 le = le->next;
567 }
568 } /* void plugin_init_all */
570 void plugin_read_all (const int *loop)
571 {
572 llentry_t *le;
573 read_func_t *rf;
575 if (list_read == NULL)
576 return;
578 pthread_mutex_lock (&read_lock);
580 le = llist_head (list_read);
581 while (le != NULL)
582 {
583 rf = (read_func_t *) le->value;
585 if (rf->needs_read != DONE)
586 {
587 le = le->next;
588 continue;
589 }
591 if (rf->wait_left > 0)
592 rf->wait_left -= interval_g;
594 if (rf->wait_left <= 0)
595 {
596 rf->needs_read = TODO;
597 }
599 le = le->next;
600 }
602 DEBUG ("plugin: plugin_read_all: Signalling `read_cond'");
603 pthread_cond_broadcast (&read_cond);
604 pthread_mutex_unlock (&read_lock);
605 } /* void plugin_read_all */
607 void plugin_shutdown_all (void)
608 {
609 int (*callback) (void);
610 llentry_t *le;
612 stop_threads ();
614 if (list_shutdown == NULL)
615 return;
617 le = llist_head (list_shutdown);
618 while (le != NULL)
619 {
620 callback = (int (*) (void)) le->value;
622 /* Advance the pointer before calling the callback allows
623 * shutdown functions to unregister themselves. If done the
624 * other way around the memory `le' points to will be freed
625 * after callback returns. */
626 le = le->next;
628 (*callback) ();
629 }
630 } /* void plugin_shutdown_all */
632 int plugin_dispatch_values (const char *name, value_list_t *vl)
633 {
634 int (*callback) (const data_set_t *, const value_list_t *);
635 data_set_t *ds;
636 llentry_t *le;
638 if ((list_write == NULL) || (list_data_set == NULL))
639 return (-1);
641 le = llist_search (list_data_set, name);
642 if (le == NULL)
643 {
644 DEBUG ("No such dataset registered: %s", name);
645 return (-1);
646 }
648 ds = (data_set_t *) le->value;
650 DEBUG ("plugin: plugin_dispatch_values: time = %u; interval = %i; "
651 "host = %s; "
652 "plugin = %s; plugin_instance = %s; "
653 "type = %s; type_instance = %s;",
654 (unsigned int) vl->time, vl->interval,
655 vl->host,
656 vl->plugin, vl->plugin_instance,
657 ds->type, vl->type_instance);
659 #if COLLECT_DEBUG
660 assert (ds->ds_num == vl->values_len);
661 #else
662 if (ds->ds_num != vl->values_len)
663 {
664 ERROR ("plugin: ds->type = %s: (ds->ds_num = %i) != "
665 "(vl->values_len = %i)",
666 ds->type, ds->ds_num, vl->values_len);
667 return (-1);
668 }
669 #endif
671 escape_slashes (vl->host, sizeof (vl->host));
672 escape_slashes (vl->plugin, sizeof (vl->plugin));
673 escape_slashes (vl->plugin_instance, sizeof (vl->plugin_instance));
674 escape_slashes (vl->type_instance, sizeof (vl->type_instance));
676 le = llist_head (list_write);
677 while (le != NULL)
678 {
679 callback = (int (*) (const data_set_t *, const value_list_t *)) le->value;
680 (*callback) (ds, vl);
682 le = le->next;
683 }
685 return (0);
686 } /* int plugin_dispatch_values */
688 void plugin_log (int level, const char *format, ...)
689 {
690 char msg[512];
691 va_list ap;
693 void (*callback) (int, const char *);
694 llentry_t *le;
696 if (list_log == NULL)
697 return;
699 #if !COLLECT_DEBUG
700 if (level >= LOG_DEBUG)
701 return;
702 #endif
704 va_start (ap, format);
705 vsnprintf (msg, 512, format, ap);
706 msg[511] = '\0';
707 va_end (ap);
709 le = llist_head (list_log);
710 while (le != NULL)
711 {
712 callback = (void (*) (int, const char *)) le->value;
713 (*callback) (level, msg);
715 le = le->next;
716 }
717 } /* void plugin_log */
719 void plugin_complain (int level, complain_t *c, const char *format, ...)
720 {
721 char message[512];
722 va_list ap;
724 if (c->delay > 0)
725 {
726 c->delay--;
727 return;
728 }
730 if (c->interval < interval_g)
731 c->interval = interval_g;
732 else
733 c->interval *= 2;
735 if (c->interval > 86400)
736 c->interval = 86400;
738 c->delay = c->interval / interval_g;
740 va_start (ap, format);
741 vsnprintf (message, 512, format, ap);
742 message[511] = '\0';
743 va_end (ap);
745 plugin_log (level, message);
746 }
748 void plugin_relief (int level, complain_t *c, const char *format, ...)
749 {
750 char message[512];
751 va_list ap;
753 if (c->interval == 0)
754 return;
756 c->interval = 0;
758 va_start (ap, format);
759 vsnprintf (message, 512, format, ap);
760 message[511] = '\0';
761 va_end (ap);
763 plugin_log (level, message);
764 }
766 const data_set_t *plugin_get_ds (const char *name)
767 {
768 data_set_t *ds;
769 llentry_t *le;
771 le = llist_search (list_data_set, name);
772 if (le == NULL)
773 {
774 DEBUG ("No such dataset registered: %s", name);
775 return (NULL);
776 }
778 ds = (data_set_t *) le->value;
780 return (ds);
781 } /* data_set_t *plugin_get_ds */