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 #include "common.h"
27 #include "plugin.h"
28 #include "configfile.h"
29 #include "utils_llist.h"
31 /*
32 * Private structures
33 */
34 struct read_func_s
35 {
36 int wait_time;
37 int wait_left;
38 int (*callback) (void);
39 };
40 typedef struct read_func_s read_func_t;
42 /*
43 * Private variables
44 */
45 static llist_t *list_init;
46 static llist_t *list_read;
47 static llist_t *list_write;
48 static llist_t *list_shutdown;
49 static llist_t *list_data_set;
50 static llist_t *list_log;
52 static char *plugindir = NULL;
54 /*
55 * Static functions
56 */
57 static const char *plugin_get_dir (void)
58 {
59 if (plugindir == NULL)
60 return (PLUGINDIR);
61 else
62 return (plugindir);
63 }
65 static int register_callback (llist_t **list, const char *name, void *callback)
66 {
67 llentry_t *le;
69 if ((*list == NULL)
70 && ((*list = llist_create ()) == NULL))
71 return (-1);
73 le = llist_search (*list, name);
74 if (le == NULL)
75 {
76 le = llentry_create (name, callback);
77 if (le == NULL)
78 return (-1);
80 llist_append (*list, le);
81 }
82 else
83 {
84 le->value = callback;
85 }
87 return (0);
88 } /* int register_callback */
90 static int plugin_unregister (llist_t *list, const char *name)
91 {
92 llentry_t *e;
94 e = llist_search (list, name);
96 if (e == NULL)
97 return (-1);
99 llist_remove (list, e);
100 llentry_destroy (e);
102 return (0);
103 } /* int plugin_unregister */
105 /*
106 * (Try to) load the shared object `file'. Won't complain if it isn't a shared
107 * object, but it will bitch about a shared object not having a
108 * ``module_register'' symbol..
109 */
110 static int plugin_load_file (char *file)
111 {
112 lt_dlhandle dlh;
113 void (*reg_handle) (void);
115 DEBUG ("file = %s", file);
117 lt_dlinit ();
118 lt_dlerror (); /* clear errors */
120 if ((dlh = lt_dlopen (file)) == NULL)
121 {
122 const char *error = lt_dlerror ();
124 ERROR ("lt_dlopen failed: %s", error);
125 DEBUG ("lt_dlopen failed: %s", error);
126 return (1);
127 }
129 if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
130 {
131 WARNING ("Couldn't find symbol ``module_register'' in ``%s'': %s\n",
132 file, lt_dlerror ());
133 lt_dlclose (dlh);
134 return (-1);
135 }
137 (*reg_handle) ();
139 return (0);
140 }
142 /*
143 * Public functions
144 */
145 void plugin_set_dir (const char *dir)
146 {
147 if (plugindir != NULL)
148 free (plugindir);
150 if (dir == NULL)
151 plugindir = NULL;
152 else if ((plugindir = strdup (dir)) == NULL)
153 {
154 char errbuf[1024];
155 ERROR ("strdup failed: %s",
156 sstrerror (errno, errbuf, sizeof (errbuf)));
157 }
158 }
160 #define BUFSIZE 512
161 int plugin_load (const char *type)
162 {
163 DIR *dh;
164 const char *dir;
165 char filename[BUFSIZE];
166 char typename[BUFSIZE];
167 int typename_len;
168 int ret;
169 struct stat statbuf;
170 struct dirent *de;
172 DEBUG ("type = %s", type);
174 dir = plugin_get_dir ();
175 ret = 1;
177 /* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
178 * type when matching the filename */
179 if (snprintf (typename, BUFSIZE, "%s.so", type) >= BUFSIZE)
180 {
181 WARNING ("snprintf: truncated: `%s.so'", type);
182 return (-1);
183 }
184 typename_len = strlen (typename);
186 if ((dh = opendir (dir)) == NULL)
187 {
188 char errbuf[1024];
189 ERROR ("opendir (%s): %s", dir,
190 sstrerror (errno, errbuf, sizeof (errbuf)));
191 return (-1);
192 }
194 while ((de = readdir (dh)) != NULL)
195 {
196 if (strncasecmp (de->d_name, typename, typename_len))
197 continue;
199 if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
200 {
201 WARNING ("snprintf: truncated: `%s/%s'", dir, de->d_name);
202 continue;
203 }
205 if (lstat (filename, &statbuf) == -1)
206 {
207 char errbuf[1024];
208 WARNING ("stat %s: %s", filename,
209 sstrerror (errno, errbuf, sizeof (errbuf)));
210 continue;
211 }
212 else if (!S_ISREG (statbuf.st_mode))
213 {
214 /* don't follow symlinks */
215 continue;
216 }
218 if (plugin_load_file (filename) == 0)
219 {
220 /* success */
221 ret = 0;
222 break;
223 }
224 }
226 closedir (dh);
228 return (ret);
229 }
231 /*
232 * The `register_*' functions follow
233 */
234 int plugin_register_config (const char *name,
235 int (*callback) (const char *key, const char *val),
236 const char **keys, int keys_num)
237 {
238 cf_register (name, callback, keys, keys_num);
239 return (0);
240 } /* int plugin_register_config */
242 int plugin_register_init (const char *name,
243 int (*callback) (void))
244 {
245 return (register_callback (&list_init, name, (void *) callback));
246 } /* plugin_register_init */
248 int plugin_register_read (const char *name,
249 int (*callback) (void))
250 {
251 read_func_t *rf;
253 rf = (read_func_t *) malloc (sizeof (read_func_t));
254 if (rf == NULL)
255 {
256 char errbuf[1024];
257 ERROR ("plugin_register_read: malloc failed: %s",
258 sstrerror (errno, errbuf, sizeof (errbuf)));
259 return (-1);
260 }
262 memset (rf, '\0', sizeof (read_func_t));
263 rf->wait_time = interval_g;
264 rf->wait_left = 0;
265 rf->callback = callback;
267 return (register_callback (&list_read, name, (void *) rf));
268 } /* int plugin_register_read */
270 int plugin_register_write (const char *name,
271 int (*callback) (const data_set_t *ds, const value_list_t *vl))
272 {
273 return (register_callback (&list_write, name, (void *) callback));
274 } /* int plugin_register_write */
276 int plugin_register_shutdown (char *name,
277 int (*callback) (void))
278 {
279 return (register_callback (&list_shutdown, name, (void *) callback));
280 } /* int plugin_register_shutdown */
282 int plugin_register_data_set (const data_set_t *ds)
283 {
284 return (register_callback (&list_data_set, ds->type, (void *) ds));
285 } /* int plugin_register_data_set */
287 int plugin_register_log (char *name,
288 void (*callback) (int priority, const char *msg))
289 {
290 return (register_callback (&list_log, name, (void *) callback));
291 } /* int plugin_register_log */
293 int plugin_unregister_config (const char *name)
294 {
295 cf_unregister (name);
296 return (0);
297 } /* int plugin_unregister_config */
299 int plugin_unregister_init (const char *name)
300 {
301 return (plugin_unregister (list_init, name));
302 }
304 int plugin_unregister_read (const char *name)
305 {
306 return (plugin_unregister (list_read, name));
307 llentry_t *e;
309 e = llist_search (list_read, name);
311 if (e == NULL)
312 return (-1);
314 llist_remove (list_read, e);
315 free (e->value);
316 llentry_destroy (e);
318 return (0);
319 }
321 int plugin_unregister_write (const char *name)
322 {
323 return (plugin_unregister (list_write, name));
324 }
326 int plugin_unregister_shutdown (const char *name)
327 {
328 return (plugin_unregister (list_shutdown, name));
329 }
331 int plugin_unregister_data_set (const char *name)
332 {
333 return (plugin_unregister (list_data_set, name));
334 }
336 int plugin_unregister_log (const char *name)
337 {
338 return (plugin_unregister (list_log, name));
339 }
341 void plugin_init_all (void)
342 {
343 int (*callback) (void);
344 llentry_t *le;
345 int status;
347 if (list_init == NULL)
348 return;
350 le = llist_head (list_init);
351 while (le != NULL)
352 {
353 callback = le->value;
354 status = (*callback) ();
356 if (status != 0)
357 {
358 ERROR ("Initialization of plugin `%s' "
359 "failed with status %i. "
360 "Plugin will be unloaded. TODO!",
361 le->key, status);
362 plugin_unregister_read (le->key);
363 }
365 le = le->next;
366 }
367 } /* void plugin_init_all */
369 void plugin_read_all (const int *loop)
370 {
371 llentry_t *le;
372 read_func_t *rf;
373 int status;
375 if (list_read == NULL)
376 return;
378 le = llist_head (list_read);
379 while ((*loop == 0) && (le != NULL))
380 {
381 rf = (read_func_t *) le->value;
383 if (rf->wait_left > 0)
384 rf->wait_left -= interval_g;
385 if (rf->wait_left > 0)
386 {
387 le = le->next;
388 continue;
389 }
391 status = rf->callback ();
392 if (status != 0)
393 {
394 rf->wait_left = rf->wait_time;
395 rf->wait_time = rf->wait_time * 2;
396 if (rf->wait_time > 86400)
397 rf->wait_time = 86400;
399 NOTICE ("read-function of plugin `%s' "
400 "failed. Will syspend it for %i "
401 "seconds.", le->key, rf->wait_left);
402 }
403 else
404 {
405 rf->wait_left = 0;
406 rf->wait_time = interval_g;
407 }
409 le = le->next;
410 } /* while ((*loop == 0) && (le != NULL)) */
411 } /* void plugin_read_all */
413 void plugin_shutdown_all (void)
414 {
415 int (*callback) (void);
416 llentry_t *le;
418 if (list_shutdown == NULL)
419 return;
421 le = llist_head (list_shutdown);
422 while (le != NULL)
423 {
424 callback = le->value;
425 (*callback) ();
427 le = le->next;
428 }
429 } /* void plugin_shutdown_all */
431 int plugin_dispatch_values (const char *name, const value_list_t *vl)
432 {
433 int (*callback) (const data_set_t *, const value_list_t *);
434 data_set_t *ds;
435 llentry_t *le;
437 if (list_write == NULL)
438 return (-1);
440 le = llist_search (list_data_set, name);
441 if (le == NULL)
442 {
443 DEBUG ("No such dataset registered: %s", name);
444 return (-1);
445 }
447 ds = (data_set_t *) le->value;
449 DEBUG ("time = %u; host = %s; "
450 "plugin = %s; plugin_instance = %s; "
451 "type = %s; type_instance = %s;",
452 (unsigned int) vl->time, vl->host,
453 vl->plugin, vl->plugin_instance,
454 ds->type, vl->type_instance);
456 le = llist_head (list_write);
457 while (le != NULL)
458 {
459 callback = le->value;
460 (*callback) (ds, vl);
462 le = le->next;
463 }
465 return (0);
466 }
468 void plugin_log (int level, const char *format, ...)
469 {
470 char msg[512];
471 va_list ap;
473 void (*callback) (int, const char *);
474 llentry_t *le;
476 if (list_log == NULL)
477 return;
479 #if !COLLECT_DEBUG
480 if (level >= LOG_DEBUG)
481 return;
482 #endif
484 va_start (ap, format);
485 vsnprintf (msg, 512, format, ap);
486 msg[511] = '\0';
487 va_end (ap);
489 le = llist_head (list_log);
490 while (le != NULL)
491 {
492 callback = le->value;
493 (*callback) (level, msg);
495 le = le->next;
496 }
497 } /* void plugin_log */
499 void plugin_complain (int level, complain_t *c, const char *format, ...)
500 {
501 char message[512];
502 va_list ap;
504 if (c->delay > 0)
505 {
506 c->delay--;
507 return;
508 }
510 if (c->interval < interval_g)
511 c->interval = interval_g;
512 else
513 c->interval *= 2;
515 if (c->interval > 86400)
516 c->interval = 86400;
518 c->delay = c->interval / interval_g;
520 va_start (ap, format);
521 vsnprintf (message, 512, format, ap);
522 message[511] = '\0';
523 va_end (ap);
525 plugin_log (level, message);
526 }
528 void plugin_relief (int level, complain_t *c, const char *format, ...)
529 {
530 char message[512];
531 va_list ap;
533 if (c->interval == 0)
534 return;
536 c->interval = 0;
538 va_start (ap, format);
539 vsnprintf (message, 512, format, ap);
540 message[511] = '\0';
541 va_end (ap);
543 plugin_log (level, message);
544 }
546 const data_set_t *plugin_get_ds (const char *name)
547 {
548 data_set_t *ds;
549 llentry_t *le;
551 le = llist_search (list_data_set, name);
552 if (le == NULL)
553 {
554 DEBUG ("No such dataset registered: %s", name);
555 return (NULL);
556 }
558 ds = (data_set_t *) le->value;
560 return (ds);
561 } /* data_set_t *plugin_get_ds */