f2e205af8479e42cbcd7129d9ab10060192a0dad
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 "plugin.h"
27 #include "configfile.h"
28 #include "utils_llist.h"
29 #include "utils_debug.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 DBG ("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 syslog (LOG_ERR, "lt_dlopen failed: %s", error);
125 DBG ("lt_dlopen failed: %s", error);
126 return (1);
127 }
129 if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
130 {
131 syslog (LOG_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 syslog (LOG_ERR, "strdup failed: %s", strerror (errno));
154 }
156 #define BUFSIZE 512
157 int plugin_load (const char *type)
158 {
159 DIR *dh;
160 const char *dir;
161 char filename[BUFSIZE];
162 char typename[BUFSIZE];
163 int typename_len;
164 int ret;
165 struct stat statbuf;
166 struct dirent *de;
168 DBG ("type = %s", type);
170 dir = plugin_get_dir ();
171 ret = 1;
173 /* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
174 * type when matching the filename */
175 if (snprintf (typename, BUFSIZE, "%s.so", type) >= BUFSIZE)
176 {
177 syslog (LOG_WARNING, "snprintf: truncated: `%s.so'", type);
178 return (-1);
179 }
180 typename_len = strlen (typename);
182 if ((dh = opendir (dir)) == NULL)
183 {
184 syslog (LOG_ERR, "opendir (%s): %s", dir, strerror (errno));
185 return (-1);
186 }
188 while ((de = readdir (dh)) != NULL)
189 {
190 if (strncasecmp (de->d_name, typename, typename_len))
191 continue;
193 if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
194 {
195 syslog (LOG_WARNING, "snprintf: truncated: `%s/%s'", dir, de->d_name);
196 continue;
197 }
199 if (lstat (filename, &statbuf) == -1)
200 {
201 syslog (LOG_WARNING, "stat %s: %s", filename, strerror (errno));
202 continue;
203 }
204 else if (!S_ISREG (statbuf.st_mode))
205 {
206 /* don't follow symlinks */
207 continue;
208 }
210 if (plugin_load_file (filename) == 0)
211 {
212 /* success */
213 ret = 0;
214 break;
215 }
216 }
218 closedir (dh);
220 return (ret);
221 }
223 /*
224 * The `register_*' functions follow
225 */
226 int plugin_register_config (const char *name,
227 int (*callback) (const char *key, const char *val),
228 const char **keys, int keys_num)
229 {
230 cf_register (name, callback, keys, keys_num);
231 return (0);
232 } /* int plugin_register_config */
234 int plugin_register_init (const char *name,
235 int (*callback) (void))
236 {
237 return (register_callback (&list_init, name, (void *) callback));
238 } /* plugin_register_init */
240 int plugin_register_read (const char *name,
241 int (*callback) (void))
242 {
243 read_func_t *rf;
245 rf = (read_func_t *) malloc (sizeof (read_func_t));
246 if (rf == NULL)
247 {
248 syslog (LOG_ERR, "plugin_register_read: malloc failed: %s",
249 strerror (errno));
250 return (-1);
251 }
253 memset (rf, '\0', sizeof (read_func_t));
254 rf->wait_time = atoi (COLLECTD_STEP);
255 rf->wait_left = 0;
256 rf->callback = callback;
258 return (register_callback (&list_read, name, (void *) rf));
259 } /* int plugin_register_read */
261 int plugin_register_write (const char *name,
262 int (*callback) (const data_set_t *ds, const value_list_t *vl))
263 {
264 return (register_callback (&list_write, name, (void *) callback));
265 } /* int plugin_register_write */
267 int plugin_register_shutdown (char *name,
268 int (*callback) (void))
269 {
270 return (register_callback (&list_shutdown, name, (void *) callback));
271 } /* int plugin_register_shutdown */
273 int plugin_register_data_set (const data_set_t *ds)
274 {
275 return (register_callback (&list_data_set, ds->type, (void *) ds));
276 } /* int plugin_register_data_set */
278 int plugin_register_log (char *name,
279 void (*callback) (int priority, const char *msg))
280 {
281 return (register_callback (&list_log, name, (void *) callback));
282 } /* int plugin_register_log */
284 int plugin_unregister_init (const char *name)
285 {
286 return (plugin_unregister (list_init, name));
287 }
289 int plugin_unregister_read (const char *name)
290 {
291 return (plugin_unregister (list_read, name));
292 llentry_t *e;
294 e = llist_search (list_read, name);
296 if (e == NULL)
297 return (-1);
299 llist_remove (list_read, e);
300 free (e->value);
301 llentry_destroy (e);
303 return (0);
304 }
306 int plugin_unregister_write (const char *name)
307 {
308 return (plugin_unregister (list_write, name));
309 }
311 int plugin_unregister_shutdown (const char *name)
312 {
313 return (plugin_unregister (list_shutdown, name));
314 }
316 int plugin_unregister_data_set (const char *name)
317 {
318 return (plugin_unregister (list_data_set, name));
319 }
321 int plugin_unregister_log (const char *name)
322 {
323 return (plugin_unregister (list_log, name));
324 }
326 void plugin_init_all (void)
327 {
328 int (*callback) (void);
329 llentry_t *le;
330 int status;
332 if (list_init == NULL)
333 return;
335 le = llist_head (list_init);
336 while (le != NULL)
337 {
338 callback = le->value;
339 status = (*callback) ();
341 if (status != 0)
342 {
343 syslog (LOG_ERR, "Initialization of plugin `%s' "
344 "failed with status %i. "
345 "Plugin will be unloaded. TODO!",
346 le->key, status);
347 plugin_unregister_read (le->key);
348 }
350 le = le->next;
351 }
352 } /* void plugin_init_all */
354 void plugin_read_all (const int *loop)
355 {
356 llentry_t *le;
357 read_func_t *rf;
358 int status;
359 int step;
361 if (list_read == NULL)
362 return;
364 step = atoi (COLLECTD_STEP);
366 le = llist_head (list_read);
367 while ((*loop == 0) && (le != NULL))
368 {
369 rf = (read_func_t *) le->value;
371 if (rf->wait_left > 0)
372 rf->wait_left -= step;
373 if (rf->wait_left > 0)
374 {
375 le = le->next;
376 continue;
377 }
379 status = rf->callback ();
380 if (status != 0)
381 {
382 rf->wait_left = rf->wait_time;
383 rf->wait_time = rf->wait_time * 2;
384 if (rf->wait_time > 86400)
385 rf->wait_time = 86400;
387 syslog (LOG_NOTICE, "read-function of plugin `%s' "
388 "failed. Will syspend it for %i "
389 "seconds.", le->key, rf->wait_left);
390 }
391 else
392 {
393 rf->wait_left = 0;
394 rf->wait_time = step;
395 }
397 le = le->next;
398 } /* while ((*loop == 0) && (le != NULL)) */
399 } /* void plugin_read_all */
401 void plugin_shutdown_all (void)
402 {
403 int (*callback) (void);
404 llentry_t *le;
406 if (list_shutdown == NULL)
407 return;
409 le = llist_head (list_shutdown);
410 while (le != NULL)
411 {
412 callback = le->value;
413 (*callback) ();
415 le = le->next;
416 }
417 } /* void plugin_shutdown_all */
419 int plugin_dispatch_values (const char *name, const value_list_t *vl)
420 {
421 int (*callback) (const data_set_t *, const value_list_t *);
422 data_set_t *ds;
423 llentry_t *le;
425 if (list_write == NULL)
426 return (-1);
428 le = llist_search (list_data_set, name);
429 if (le == NULL)
430 {
431 DBG ("No such dataset registered: %s", name);
432 return (-1);
433 }
435 ds = (data_set_t *) le->value;
437 DBG ("time = %u; host = %s; "
438 "plugin = %s; plugin_instance = %s; "
439 "type = %s; type_instance = %s;",
440 (unsigned int) vl->time, vl->host,
441 vl->plugin, vl->plugin_instance,
442 ds->type, vl->type_instance);
444 le = llist_head (list_write);
445 while (le != NULL)
446 {
447 callback = le->value;
448 (*callback) (ds, vl);
450 le = le->next;
451 }
453 return (0);
454 }
456 void plugin_log (int level, const char *format, ...)
457 {
458 char msg[512];
459 va_list ap;
461 void (*callback) (int, const char *);
462 llentry_t *le;
464 #if !COLLECT_DEBUG
465 if (level >= LOG_DEBUG)
466 return;
467 #endif
469 va_start (ap, format);
470 vsnprintf (msg, 512, format, ap);
471 msg[511] = '\0';
472 va_end (ap);
474 le = llist_head (list_log);
475 while (le != NULL)
476 {
477 callback = le->value;
478 (*callback) (level, msg);
480 le = le->next;
481 }
482 } /* void plugin_log */
484 void plugin_complain (int level, complain_t *c, const char *format, ...)
485 {
486 char message[512];
487 va_list ap;
488 int step;
490 if (c->delay > 0)
491 {
492 c->delay--;
493 return;
494 }
496 step = atoi (COLLECTD_STEP);
497 assert (step > 0);
499 if (c->interval < step)
500 c->interval = step;
501 else
502 c->interval *= 2;
504 if (c->interval > 86400)
505 c->interval = 86400;
507 c->delay = c->interval / step;
509 va_start (ap, format);
510 vsnprintf (message, 512, format, ap);
511 message[511] = '\0';
512 va_end (ap);
514 syslog (level, message);
515 }
517 void plugin_relief (int level, complain_t *c, const char *format, ...)
518 {
519 char message[512];
520 va_list ap;
522 if (c->interval == 0)
523 return;
525 c->interval = 0;
527 va_start (ap, format);
528 vsnprintf (message, 512, format, ap);
529 message[511] = '\0';
530 va_end (ap);
532 syslog (level, message);
533 }