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 variables
33 */
34 static llist_t *list_init;
35 static llist_t *list_read;
36 static llist_t *list_write;
37 static llist_t *list_shutdown;
38 static llist_t *list_data_set;
40 static char *plugindir = NULL;
42 /*
43 * Static functions
44 */
45 static const char *plugin_get_dir (void)
46 {
47 if (plugindir == NULL)
48 return (PLUGINDIR);
49 else
50 return (plugindir);
51 }
53 static int register_callback (llist_t **list, const char *name, void *callback)
54 {
55 llentry_t *le;
57 if ((*list == NULL)
58 && ((*list = llist_create ()) == NULL))
59 return (-1);
61 le = llist_search (*list, name);
62 if (le == NULL)
63 {
64 le = llentry_create (name, callback);
65 if (le == NULL)
66 return (-1);
68 llist_append (*list, le);
69 }
70 else
71 {
72 le->value = callback;
73 }
75 return (0);
76 } /* int register_callback */
78 /*
79 * (Try to) load the shared object `file'. Won't complain if it isn't a shared
80 * object, but it will bitch about a shared object not having a
81 * ``module_register'' symbol..
82 */
83 static int plugin_load_file (char *file)
84 {
85 lt_dlhandle dlh;
86 void (*reg_handle) (void);
88 DBG ("file = %s", file);
90 lt_dlinit ();
91 lt_dlerror (); /* clear errors */
93 if ((dlh = lt_dlopen (file)) == NULL)
94 {
95 const char *error = lt_dlerror ();
97 syslog (LOG_ERR, "lt_dlopen failed: %s", error);
98 DBG ("lt_dlopen failed: %s", error);
99 return (1);
100 }
102 if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
103 {
104 syslog (LOG_WARNING, "Couldn't find symbol ``module_register'' in ``%s'': %s\n",
105 file, lt_dlerror ());
106 lt_dlclose (dlh);
107 return (-1);
108 }
110 (*reg_handle) ();
112 return (0);
113 }
115 /*
116 * Public functions
117 */
118 void plugin_set_dir (const char *dir)
119 {
120 if (plugindir != NULL)
121 free (plugindir);
123 if (dir == NULL)
124 plugindir = NULL;
125 else if ((plugindir = strdup (dir)) == NULL)
126 syslog (LOG_ERR, "strdup failed: %s", strerror (errno));
127 }
129 #define BUFSIZE 512
130 int plugin_load (const char *type)
131 {
132 DIR *dh;
133 const char *dir;
134 char filename[BUFSIZE];
135 char typename[BUFSIZE];
136 int typename_len;
137 int ret;
138 struct stat statbuf;
139 struct dirent *de;
141 DBG ("type = %s", type);
143 dir = plugin_get_dir ();
144 ret = 1;
146 /* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
147 * type when matching the filename */
148 if (snprintf (typename, BUFSIZE, "%s.so", type) >= BUFSIZE)
149 {
150 syslog (LOG_WARNING, "snprintf: truncated: `%s.so'", type);
151 return (-1);
152 }
153 typename_len = strlen (typename);
155 if ((dh = opendir (dir)) == NULL)
156 {
157 syslog (LOG_ERR, "opendir (%s): %s", dir, strerror (errno));
158 return (-1);
159 }
161 while ((de = readdir (dh)) != NULL)
162 {
163 if (strncasecmp (de->d_name, typename, typename_len))
164 continue;
166 if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
167 {
168 syslog (LOG_WARNING, "snprintf: truncated: `%s/%s'", dir, de->d_name);
169 continue;
170 }
172 if (lstat (filename, &statbuf) == -1)
173 {
174 syslog (LOG_WARNING, "stat %s: %s", filename, strerror (errno));
175 continue;
176 }
177 else if (!S_ISREG (statbuf.st_mode))
178 {
179 /* don't follow symlinks */
180 continue;
181 }
183 if (plugin_load_file (filename) == 0)
184 {
185 /* success */
186 ret = 0;
187 break;
188 }
189 }
191 closedir (dh);
193 return (ret);
194 }
196 /*
197 * The `register_*' functions follow
198 */
199 int plugin_register_config (const char *name,
200 int (*callback) (const char *key, const char *val),
201 const char **keys, int keys_num)
202 {
203 cf_register (name, callback, keys, keys_num);
204 return (0);
205 } /* int plugin_register_config */
207 int plugin_register_init (const char *name,
208 int (*callback) (void))
209 {
210 return (register_callback (&list_init, name, (void *) callback));
211 } /* plugin_register_init */
213 int plugin_register_read (const char *name,
214 int (*callback) (void))
215 {
216 return (register_callback (&list_read, name, (void *) callback));
217 } /* int plugin_register_read */
219 int plugin_register_write (const char *name,
220 int (*callback) (const data_set_t *ds, const value_list_t *vl))
221 {
222 return (register_callback (&list_write, name, (void *) callback));
223 } /* int plugin_register_write */
225 int plugin_register_shutdown (char *name,
226 int (*callback) (void))
227 {
228 return (register_callback (&list_shutdown, name, (void *) callback));
229 } /* int plugin_register_shutdown */
231 int plugin_register_data_set (const data_set_t *ds)
232 {
233 return (register_callback (&list_data_set, ds->type, (void *) ds));
234 } /* int plugin_register_data_set */
236 void plugin_init_all (void)
237 {
238 int (*callback) (void);
239 llentry_t *le;
241 if (list_init == NULL)
242 return;
244 le = llist_head (list_init);
245 while (le != NULL)
246 {
247 callback = le->value;
248 (*callback) ();
250 le = le->next;
251 }
252 } /* void plugin_init_all */
254 void plugin_read_all (const int *loop)
255 {
256 int (*callback) (void);
257 llentry_t *le;
259 if (list_read == NULL)
260 return;
262 le = llist_head (list_read);
263 while ((*loop == 0) && (le != NULL))
264 {
265 callback = le->value;
266 (*callback) ();
268 le = le->next;
269 }
270 } /* void plugin_read_all */
272 void plugin_shutdown_all (void)
273 {
274 int (*callback) (void);
275 llentry_t *le;
277 if (list_shutdown == NULL)
278 return;
280 le = llist_head (list_shutdown);
281 while (le != NULL)
282 {
283 callback = le->value;
284 (*callback) ();
286 le = le->next;
287 }
288 } /* void plugin_shutdown_all */
290 int plugin_dispatch_values (const char *name, const value_list_t *vl)
291 {
292 int (*callback) (const data_set_t *, const value_list_t *);
293 data_set_t *ds;
294 llentry_t *le;
296 if (list_write == NULL)
297 return (-1);
299 le = llist_search (list_data_set, name);
300 if (le == NULL)
301 return (-1);
303 ds = (data_set_t *) le->value;
305 DBG ("time = %u; host = %s; "
306 "plugin = %s; plugin_instance = %s; "
307 "type = %s; type_instance = %s;",
308 (unsigned int) vl->time, vl->host,
309 vl->plugin, vl->plugin_instance,
310 ds->type, vl->type_instance);
312 le = llist_head (list_write);
313 while (le != NULL)
314 {
315 callback = le->value;
316 (*callback) (ds, vl);
318 le = le->next;
319 }
321 return (0);
322 }
324 void plugin_complain (int level, complain_t *c, const char *format, ...)
325 {
326 char message[512];
327 va_list ap;
328 int step;
330 if (c->delay > 0)
331 {
332 c->delay--;
333 return;
334 }
336 step = atoi (COLLECTD_STEP);
337 assert (step > 0);
339 if (c->interval < step)
340 c->interval = step;
341 else
342 c->interval *= 2;
344 if (c->interval > 86400)
345 c->interval = 86400;
347 c->delay = c->interval / step;
349 va_start (ap, format);
350 vsnprintf (message, 512, format, ap);
351 message[511] = '\0';
352 va_end (ap);
354 syslog (level, message);
355 }
357 void plugin_relief (int level, complain_t *c, const char *format, ...)
358 {
359 char message[512];
360 va_list ap;
362 if (c->interval == 0)
363 return;
365 c->interval = 0;
367 va_start (ap, format);
368 vsnprintf (message, 512, format, ap);
369 message[511] = '\0';
370 va_end (ap);
372 syslog (level, message);
373 }