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 fprintf (stderr, "lt_dlopen failed: %s\n", error);
137 return (1);
138 }
140 if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
141 {
142 WARNING ("Couldn't find symbol ``module_register'' in ``%s'': %s\n",
143 file, lt_dlerror ());
144 lt_dlclose (dlh);
145 return (-1);
146 }
148 (*reg_handle) ();
150 return (0);
151 }
153 static void *plugin_read_thread (void *args)
154 {
155 llentry_t *le;
156 read_func_t *rf;
157 int status;
158 int done;
160 pthread_mutex_lock (&read_lock);
162 while (read_loop != 0)
163 {
164 le = llist_head (list_read);
165 done = 0;
167 while ((read_loop != 0) && (le != NULL))
168 {
169 rf = (read_func_t *) le->value;
171 if (rf->needs_read != TODO)
172 {
173 le = le->next;
174 continue;
175 }
177 /* We will do this read function */
178 rf->needs_read = ACTIVE;
180 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Handling %s",
181 (unsigned long int) pthread_self (), le->key);
182 pthread_mutex_unlock (&read_lock);
184 status = rf->callback ();
185 done++;
187 if (status != 0)
188 {
189 if (rf->wait_time < interval_g)
190 rf->wait_time = interval_g;
191 rf->wait_left = rf->wait_time;
192 rf->wait_time = rf->wait_time * 2;
193 if (rf->wait_time > 86400)
194 rf->wait_time = 86400;
196 NOTICE ("read-function of plugin `%s' "
197 "failed. Will syspend it for %i "
198 "seconds.", le->key, rf->wait_left);
199 }
200 else
201 {
202 rf->wait_left = 0;
203 rf->wait_time = interval_g;
204 }
206 pthread_mutex_lock (&read_lock);
208 rf->needs_read = DONE;
209 le = le->next;
210 } /* while (le != NULL) */
212 if ((read_loop != 0) && (done == 0))
213 {
214 DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Waiting on read_cond.",
215 (unsigned long int) pthread_self ());
216 pthread_cond_wait (&read_cond, &read_lock);
217 }
218 } /* while (read_loop) */
220 pthread_mutex_unlock (&read_lock);
222 pthread_exit (NULL);
223 } /* void *plugin_read_thread */
225 static void start_threads (int num)
226 {
227 int i;
229 if (read_threads != NULL)
230 return;
232 read_threads = (pthread_t *) calloc (num, sizeof (pthread_t));
233 if (read_threads == NULL)
234 {
235 ERROR ("plugin: start_threads: calloc failed.");
236 return;
237 }
239 read_threads_num = 0;
240 for (i = 0; i < num; i++)
241 {
242 if (pthread_create (read_threads + read_threads_num, NULL,
243 plugin_read_thread, NULL) == 0)
244 {
245 read_threads_num++;
246 }
247 else
248 {
249 ERROR ("plugin: start_threads: pthread_create failed.");
250 return;
251 }
252 } /* for (i) */
253 } /* void start_threads */
255 static void stop_threads (void)
256 {
257 int i;
259 pthread_mutex_lock (&read_lock);
260 read_loop = 0;
261 DEBUG ("plugin: stop_threads: Signalling `read_cond'");
262 pthread_cond_broadcast (&read_cond);
263 pthread_mutex_unlock (&read_lock);
265 for (i = 0; i < read_threads_num; i++)
266 {
267 if (pthread_join (read_threads[i], NULL) != 0)
268 {
269 ERROR ("plugin: stop_threads: pthread_join failed.");
270 }
271 read_threads[i] = (pthread_t) 0;
272 }
273 sfree (read_threads);
274 read_threads_num = 0;
275 } /* void stop_threads */
277 /*
278 * Public functions
279 */
280 void plugin_set_dir (const char *dir)
281 {
282 if (plugindir != NULL)
283 free (plugindir);
285 if (dir == NULL)
286 plugindir = NULL;
287 else if ((plugindir = strdup (dir)) == NULL)
288 {
289 char errbuf[1024];
290 ERROR ("strdup failed: %s",
291 sstrerror (errno, errbuf, sizeof (errbuf)));
292 }
293 }
295 #define BUFSIZE 512
296 int plugin_load (const char *type)
297 {
298 DIR *dh;
299 const char *dir;
300 char filename[BUFSIZE];
301 char typename[BUFSIZE];
302 int typename_len;
303 int ret;
304 struct stat statbuf;
305 struct dirent *de;
307 DEBUG ("type = %s", type);
309 dir = plugin_get_dir ();
310 ret = 1;
312 /* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
313 * type when matching the filename */
314 if (snprintf (typename, BUFSIZE, "%s.so", type) >= BUFSIZE)
315 {
316 WARNING ("snprintf: truncated: `%s.so'", type);
317 return (-1);
318 }
319 typename_len = strlen (typename);
321 if ((dh = opendir (dir)) == NULL)
322 {
323 char errbuf[1024];
324 ERROR ("opendir (%s): %s", dir,
325 sstrerror (errno, errbuf, sizeof (errbuf)));
326 return (-1);
327 }
329 while ((de = readdir (dh)) != NULL)
330 {
331 if (strncasecmp (de->d_name, typename, typename_len))
332 continue;
334 if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
335 {
336 WARNING ("snprintf: truncated: `%s/%s'", dir, de->d_name);
337 continue;
338 }
340 if (lstat (filename, &statbuf) == -1)
341 {
342 char errbuf[1024];
343 WARNING ("stat %s: %s", filename,
344 sstrerror (errno, errbuf, sizeof (errbuf)));
345 continue;
346 }
347 else if (!S_ISREG (statbuf.st_mode))
348 {
349 /* don't follow symlinks */
350 continue;
351 }
353 if (plugin_load_file (filename) == 0)
354 {
355 /* success */
356 ret = 0;
357 break;
358 }
359 else
360 {
361 fprintf (stderr, "Unable to load plugin %s.\n", type);
362 }
363 }
365 closedir (dh);
367 return (ret);
368 }
370 /*
371 * The `register_*' functions follow
372 */
373 int plugin_register_config (const char *name,
374 int (*callback) (const char *key, const char *val),
375 const char **keys, int keys_num)
376 {
377 cf_register (name, callback, keys, keys_num);
378 return (0);
379 } /* int plugin_register_config */
381 int plugin_register_init (const char *name,
382 int (*callback) (void))
383 {
384 return (register_callback (&list_init, name, (void *) callback));
385 } /* plugin_register_init */
387 int plugin_register_read (const char *name,
388 int (*callback) (void))
389 {
390 read_func_t *rf;
392 rf = (read_func_t *) malloc (sizeof (read_func_t));
393 if (rf == NULL)
394 {
395 char errbuf[1024];
396 ERROR ("plugin_register_read: malloc failed: %s",
397 sstrerror (errno, errbuf, sizeof (errbuf)));
398 return (-1);
399 }
401 memset (rf, '\0', sizeof (read_func_t));
402 rf->wait_time = interval_g;
403 rf->wait_left = 0;
404 rf->callback = callback;
405 rf->needs_read = DONE;
407 return (register_callback (&list_read, name, (void *) rf));
408 } /* int plugin_register_read */
410 int plugin_register_write (const char *name,
411 int (*callback) (const data_set_t *ds, const value_list_t *vl))
412 {
413 return (register_callback (&list_write, name, (void *) callback));
414 } /* int plugin_register_write */
416 int plugin_register_shutdown (char *name,
417 int (*callback) (void))
418 {
419 return (register_callback (&list_shutdown, name, (void *) callback));
420 } /* int plugin_register_shutdown */
422 int plugin_register_data_set (const data_set_t *ds)
423 {
424 data_set_t *ds_copy;
425 int i;
427 if ((list_data_set != NULL)
428 && (llist_search (list_data_set, ds->type) != NULL))
429 {
430 NOTICE ("Replacing DS `%s' with another version.", ds->type);
431 plugin_unregister_data_set (ds->type);
432 }
434 ds_copy = (data_set_t *) malloc (sizeof (data_set_t));
435 if (ds_copy == NULL)
436 return (-1);
437 memcpy(ds_copy, ds, sizeof (data_set_t));
439 ds_copy->ds = (data_source_t *) malloc (sizeof (data_source_t)
440 * ds->ds_num);
441 if (ds_copy->ds == NULL)
442 {
443 free (ds_copy);
444 return (-1);
445 }
447 for (i = 0; i < ds->ds_num; i++)
448 memcpy (ds_copy->ds + i, ds->ds + i, sizeof (data_source_t));
450 return (register_callback (&list_data_set, ds->type, (void *) ds_copy));
451 } /* int plugin_register_data_set */
453 int plugin_register_log (char *name,
454 void (*callback) (int priority, const char *msg))
455 {
456 return (register_callback (&list_log, name, (void *) callback));
457 } /* int plugin_register_log */
459 int plugin_unregister_config (const char *name)
460 {
461 cf_unregister (name);
462 return (0);
463 } /* int plugin_unregister_config */
465 int plugin_unregister_init (const char *name)
466 {
467 return (plugin_unregister (list_init, name));
468 }
470 int plugin_unregister_read (const char *name)
471 {
472 llentry_t *e;
474 e = llist_search (list_read, name);
476 if (e == NULL)
477 return (-1);
479 llist_remove (list_read, e);
480 free (e->value);
481 llentry_destroy (e);
483 return (0);
484 }
486 int plugin_unregister_write (const char *name)
487 {
488 return (plugin_unregister (list_write, name));
489 }
491 int plugin_unregister_shutdown (const char *name)
492 {
493 return (plugin_unregister (list_shutdown, name));
494 }
496 int plugin_unregister_data_set (const char *name)
497 {
498 llentry_t *e;
499 data_set_t *ds;
501 if (list_data_set == NULL)
502 return (-1);
504 e = llist_search (list_data_set, name);
506 if (e == NULL)
507 return (-1);
509 llist_remove (list_data_set, e);
510 ds = (data_set_t *) e->value;
511 llentry_destroy (e);
513 sfree (ds->ds);
514 sfree (ds);
516 return (0);
517 } /* int plugin_unregister_data_set */
519 int plugin_unregister_log (const char *name)
520 {
521 return (plugin_unregister (list_log, name));
522 }
524 void plugin_init_all (void)
525 {
526 int (*callback) (void);
527 llentry_t *le;
528 int status;
530 /* Start read-threads */
531 if (list_read != NULL)
532 {
533 const char *rt;
534 int num;
535 rt = global_option_get ("ReadThreads");
536 num = atoi (rt);
537 start_threads ((num > 0) ? num : 5);
538 }
540 if (list_init == NULL)
541 return;
543 le = llist_head (list_init);
544 while (le != NULL)
545 {
546 callback = (int (*) (void)) le->value;
547 status = (*callback) ();
549 if (status != 0)
550 {
551 ERROR ("Initialization of plugin `%s' "
552 "failed with status %i. "
553 "Plugin will be unloaded.",
554 le->key, status);
555 /* FIXME: Unload _all_ functions */
556 plugin_unregister_read (le->key);
557 }
559 le = le->next;
560 }
561 } /* void plugin_init_all */
563 void plugin_read_all (const int *loop)
564 {
565 llentry_t *le;
566 read_func_t *rf;
568 if (list_read == NULL)
569 return;
571 pthread_mutex_lock (&read_lock);
573 le = llist_head (list_read);
574 while (le != NULL)
575 {
576 rf = (read_func_t *) le->value;
578 if (rf->needs_read != DONE)
579 {
580 le = le->next;
581 continue;
582 }
584 if (rf->wait_left > 0)
585 rf->wait_left -= interval_g;
587 if (rf->wait_left <= 0)
588 {
589 rf->needs_read = TODO;
590 }
592 le = le->next;
593 }
595 DEBUG ("plugin: plugin_read_all: Signalling `read_cond'");
596 pthread_cond_broadcast (&read_cond);
597 pthread_mutex_unlock (&read_lock);
598 } /* void plugin_read_all */
600 void plugin_shutdown_all (void)
601 {
602 int (*callback) (void);
603 llentry_t *le;
605 stop_threads ();
607 if (list_shutdown == NULL)
608 return;
610 le = llist_head (list_shutdown);
611 while (le != NULL)
612 {
613 callback = (int (*) (void)) le->value;
615 /* Advance the pointer before calling the callback allows
616 * shutdown functions to unregister themselves. If done the
617 * other way around the memory `le' points to will be freed
618 * after callback returns. */
619 le = le->next;
621 (*callback) ();
622 }
623 } /* void plugin_shutdown_all */
625 int plugin_dispatch_values (const char *name, value_list_t *vl)
626 {
627 int (*callback) (const data_set_t *, const value_list_t *);
628 data_set_t *ds;
629 llentry_t *le;
631 if ((list_write == NULL) || (list_data_set == NULL))
632 return (-1);
634 le = llist_search (list_data_set, name);
635 if (le == NULL)
636 {
637 DEBUG ("No such dataset registered: %s", name);
638 return (-1);
639 }
641 ds = (data_set_t *) le->value;
643 DEBUG ("plugin: plugin_dispatch_values: time = %u; host = %s; "
644 "plugin = %s; plugin_instance = %s; type = %s; "
645 "type_instance = %s;",
646 (unsigned int) vl->time, vl->host,
647 vl->plugin, vl->plugin_instance,
648 ds->type, vl->type_instance);
650 #if COLLECT_DEBUG
651 assert (ds->ds_num == vl->values_len);
652 #else
653 if (ds->ds_num != vl->values_len)
654 {
655 ERROR ("plugin: ds->type = %s: (ds->ds_num = %i) != "
656 "(vl->values_len = %i)",
657 ds->type, ds->ds_num, vl->values_len);
658 return (-1);
659 }
660 #endif
662 escape_slashes (vl->host, sizeof (vl->host));
663 escape_slashes (vl->plugin, sizeof (vl->plugin));
664 escape_slashes (vl->plugin_instance, sizeof (vl->plugin_instance));
665 escape_slashes (vl->type_instance, sizeof (vl->type_instance));
667 le = llist_head (list_write);
668 while (le != NULL)
669 {
670 callback = (int (*) (const data_set_t *, const value_list_t *)) le->value;
671 (*callback) (ds, vl);
673 le = le->next;
674 }
676 return (0);
677 } /* int plugin_dispatch_values */
679 void plugin_log (int level, const char *format, ...)
680 {
681 char msg[512];
682 va_list ap;
684 void (*callback) (int, const char *);
685 llentry_t *le;
687 if (list_log == NULL)
688 return;
690 #if !COLLECT_DEBUG
691 if (level >= LOG_DEBUG)
692 return;
693 #endif
695 va_start (ap, format);
696 vsnprintf (msg, 512, format, ap);
697 msg[511] = '\0';
698 va_end (ap);
700 le = llist_head (list_log);
701 while (le != NULL)
702 {
703 callback = (void (*) (int, const char *)) le->value;
704 (*callback) (level, msg);
706 le = le->next;
707 }
708 } /* void plugin_log */
710 void plugin_complain (int level, complain_t *c, const char *format, ...)
711 {
712 char message[512];
713 va_list ap;
715 if (c->delay > 0)
716 {
717 c->delay--;
718 return;
719 }
721 if (c->interval < interval_g)
722 c->interval = interval_g;
723 else
724 c->interval *= 2;
726 if (c->interval > 86400)
727 c->interval = 86400;
729 c->delay = c->interval / interval_g;
731 va_start (ap, format);
732 vsnprintf (message, 512, format, ap);
733 message[511] = '\0';
734 va_end (ap);
736 plugin_log (level, message);
737 }
739 void plugin_relief (int level, complain_t *c, const char *format, ...)
740 {
741 char message[512];
742 va_list ap;
744 if (c->interval == 0)
745 return;
747 c->interval = 0;
749 va_start (ap, format);
750 vsnprintf (message, 512, format, ap);
751 message[511] = '\0';
752 va_end (ap);
754 plugin_log (level, message);
755 }
757 const data_set_t *plugin_get_ds (const char *name)
758 {
759 data_set_t *ds;
760 llentry_t *le;
762 le = llist_search (list_data_set, name);
763 if (le == NULL)
764 {
765 DEBUG ("No such dataset registered: %s", name);
766 return (NULL);
767 }
769 ds = (data_set_t *) le->value;
771 return (ds);
772 } /* data_set_t *plugin_get_ds */