1 /*
2 * SysDB - src/core/plugin.c
3 * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #include "sysdb.h"
29 #include "core/plugin.h"
30 #include "utils/error.h"
31 #include "utils/llist.h"
32 #include "utils/time.h"
34 #include <assert.h>
36 #include <errno.h>
38 #include <stdarg.h>
39 #include <stdio.h>
40 #include <string.h>
41 #include <strings.h>
42 #include <unistd.h>
44 #include <ltdl.h>
46 #include <pthread.h>
48 /*
49 * private data types
50 */
52 struct sdb_plugin_info {
53 char *name;
55 char *description;
56 char *copyright;
57 char *license;
59 int version;
60 int plugin_version;
61 };
62 #define SDB_PLUGIN_INFO_INIT { "no name set", "no description set", \
63 /* copyright */ "", /* license */ "", \
64 /* version */ -1, /* plugin_version */ -1 }
66 typedef struct {
67 sdb_object_t super;
68 char cb_name[64];
69 void *cb_callback;
70 sdb_object_t *cb_user_data;
71 sdb_plugin_ctx_t cb_ctx;
72 } sdb_plugin_cb_t;
73 #define SDB_PLUGIN_CB_INIT { SDB_OBJECT_INIT, /* name = */ "", \
74 /* callback = */ NULL, /* user_data = */ NULL, \
75 SDB_PLUGIN_CTX_INIT }
77 typedef struct {
78 sdb_plugin_cb_t super;
79 #define ccb_name super.cb_name
80 #define ccb_callback super.cb_callback
81 #define ccb_user_data super.cb_user_data
82 #define ccb_ctx super.cb_ctx
83 sdb_time_t ccb_interval;
84 sdb_time_t ccb_next_update;
85 } sdb_plugin_collector_cb_t;
87 #define SDB_PLUGIN_CB(obj) ((sdb_plugin_cb_t *)(obj))
88 #define SDB_PLUGIN_CCB(obj) ((sdb_plugin_collector_cb_t *)(obj))
90 /*
91 * private variables
92 */
94 static sdb_plugin_ctx_t plugin_default_ctx = SDB_PLUGIN_CTX_INIT;
96 static pthread_key_t plugin_ctx_key;
97 static _Bool plugin_ctx_key_initialized = 0;
99 static sdb_llist_t *config_list = NULL;
100 static sdb_llist_t *init_list = NULL;
101 static sdb_llist_t *collector_list = NULL;
102 static sdb_llist_t *shutdown_list = NULL;
104 /*
105 * private helper functions
106 */
108 static void
109 sdb_plugin_ctx_destructor(void *ctx)
110 {
111 if (! ctx)
112 return;
113 free(ctx);
114 } /* sdb_plugin_ctx_destructor */
116 static void
117 sdb_plugin_ctx_init(void)
118 {
119 if (plugin_ctx_key_initialized)
120 return;
122 pthread_key_create(&plugin_ctx_key, sdb_plugin_ctx_destructor);
123 plugin_ctx_key_initialized = 1;
124 } /* sdb_plugin_ctx_init */
126 static sdb_plugin_ctx_t *
127 sdb_plugin_ctx_create(void)
128 {
129 sdb_plugin_ctx_t *ctx;
131 ctx = malloc(sizeof(*ctx));
132 if (! ctx)
133 return NULL;
135 *ctx = plugin_default_ctx;
137 if (! plugin_ctx_key_initialized)
138 sdb_plugin_ctx_init();
139 pthread_setspecific(plugin_ctx_key, ctx);
140 return ctx;
141 } /* sdb_plugin_ctx_create */
143 static int
144 sdb_plugin_cmp_name(const sdb_object_t *a, const sdb_object_t *b)
145 {
146 const sdb_plugin_cb_t *cb1 = (const sdb_plugin_cb_t *)a;
147 const sdb_plugin_cb_t *cb2 = (const sdb_plugin_cb_t *)b;
149 assert(cb1 && cb2);
150 return strcasecmp(cb1->cb_name, cb2->cb_name);
151 } /* sdb_plugin_cmp_name */
153 static int
154 sdb_plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
155 {
156 const sdb_plugin_collector_cb_t *ccb1
157 = (const sdb_plugin_collector_cb_t *)a;
158 const sdb_plugin_collector_cb_t *ccb2
159 = (const sdb_plugin_collector_cb_t *)b;
161 assert(ccb1 && ccb2);
163 return (ccb1->ccb_next_update > ccb2->ccb_next_update)
164 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
165 ? -1 : 0;
166 } /* sdb_plugin_cmp_next_update */
168 static sdb_plugin_cb_t *
169 sdb_plugin_find_by_name(sdb_llist_t *list, const char *name)
170 {
171 sdb_plugin_cb_t tmp = SDB_PLUGIN_CB_INIT;
173 sdb_object_t *obj;
174 assert(name);
176 if (! list)
177 return NULL;
179 snprintf(tmp.cb_name, sizeof(tmp.cb_name), "%s", name);
180 tmp.cb_name[sizeof(tmp.cb_name) - 1] = '\0';
181 obj = sdb_llist_search(list, SDB_OBJ(&tmp), sdb_plugin_cmp_name);
182 if (! obj)
183 return NULL;
184 return SDB_PLUGIN_CB(obj);
185 } /* sdb_plugin_find_by_name */
187 static int
188 sdb_plugin_cb_init(sdb_object_t *obj, va_list ap)
189 {
190 sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
191 const char *type = va_arg(ap, const char *);
192 const char *name = va_arg(ap, const char *);
193 void *callback = va_arg(ap, void *);
194 sdb_object_t *ud = va_arg(ap, sdb_object_t *);
196 assert(list);
197 assert(type);
198 assert(obj);
200 if (sdb_plugin_find_by_name(*list, name)) {
201 sdb_log(SDB_LOG_WARNING, "plugin: %s callback '%s' "
202 "has already been registered. Ignoring newly "
203 "registered version.\n", type, name);
204 return -1;
205 }
207 snprintf(SDB_PLUGIN_CB(obj)->cb_name,
208 sizeof(SDB_PLUGIN_CB(obj)->cb_name),
209 "%s", name);
210 SDB_PLUGIN_CB(obj)->cb_name[sizeof(SDB_PLUGIN_CB(obj)->cb_name) - 1] = '\0';
211 SDB_PLUGIN_CB(obj)->cb_callback = callback;
212 SDB_PLUGIN_CB(obj)->cb_ctx = sdb_plugin_get_ctx();
214 sdb_object_ref(ud);
215 SDB_PLUGIN_CB(obj)->cb_user_data = ud;
216 return 0;
217 } /* sdb_plugin_cb_init */
219 static void
220 sdb_plugin_cb_destroy(sdb_object_t *obj)
221 {
222 assert(obj);
223 sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
224 } /* sdb_plugin_cb_destroy */
226 static int
227 sdb_plugin_add_callback(sdb_llist_t **list, const char *type,
228 const char *name, void *callback, sdb_object_t *user_data)
229 {
230 sdb_object_t *obj;
232 if ((! name) || (! callback))
233 return -1;
235 assert(list);
237 if (! *list)
238 *list = sdb_llist_create();
239 if (! *list)
240 return -1;
242 obj = sdb_object_create(sizeof(sdb_plugin_cb_t), sdb_plugin_cb_init,
243 sdb_plugin_cb_destroy, list, type, name, callback, user_data);
244 if (! obj)
245 return -1;
247 if (sdb_llist_append(*list, obj)) {
248 sdb_object_deref(obj);
249 return -1;
250 }
252 /* pass control to the list */
253 sdb_object_deref(obj);
255 sdb_log(SDB_LOG_INFO, "plugin: Registered %s callback '%s'.\n",
256 type, name);
257 return 0;
258 } /* sdb_plugin_add_callback */
260 /*
261 * public API
262 */
264 int
265 sdb_plugin_load(const char *name)
266 {
267 char filename[1024];
269 lt_dlhandle lh;
271 int (*mod_init)(sdb_plugin_info_t *);
272 sdb_plugin_info_t plugin_info = SDB_PLUGIN_INFO_INIT;
274 int status;
276 snprintf(filename, sizeof(filename), "%s/%s.so",
277 PKGLIBDIR, name);
278 filename[sizeof(filename) - 1] = '\0';
280 if (access(filename, R_OK)) {
281 char errbuf[1024];
282 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s': %s\n",
283 name, sdb_strerror(errno, errbuf, sizeof(errbuf)));
284 return -1;
285 }
287 lt_dlinit();
288 lt_dlerror();
290 lh = lt_dlopen(filename);
291 if (! lh) {
292 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s': %s\n"
293 "The most common cause for this problem are missing "
294 "dependencies.\n", name, lt_dlerror());
295 return -1;
296 }
298 mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
299 if (! mod_init) {
300 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s': "
301 "could not find symbol 'sdb_module_init'\n", name);
302 return -1;
303 }
305 status = mod_init(&plugin_info);
306 if (status) {
307 sdb_log(SDB_LOG_ERR, "plugin: Failed to initialize "
308 "plugin '%s'\n", name);
309 return -1;
310 }
312 /* compare minor version */
313 if ((plugin_info.version < 0)
314 || ((int)(plugin_info.version / 100) != (int)(SDB_VERSION / 100)))
315 sdb_log(SDB_LOG_WARNING, "plugin: WARNING: version of "
316 "plugin '%s' (%i.%i.%i) does not match our version "
317 "(%i.%i.%i); this might cause problems\n",
318 name, SDB_VERSION_DECODE(plugin_info.version),
319 SDB_VERSION_DECODE(SDB_VERSION));
321 sdb_log(SDB_LOG_INFO, "plugin: Successfully loaded "
322 "plugin '%s' v%i (%s)\n\t%s\n",
323 plugin_info.name, plugin_info.plugin_version,
324 plugin_info.description, plugin_info.copyright);
325 return 0;
326 } /* sdb_plugin_load */
328 int
329 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
330 {
331 va_list ap;
333 if (! info)
334 return -1;
336 va_start(ap, type);
338 switch (type) {
339 case SDB_PLUGIN_INFO_NAME:
340 {
341 char *name = va_arg(ap, char *);
342 info->name = name;
343 }
344 break;
345 case SDB_PLUGIN_INFO_DESC:
346 {
347 char *desc = va_arg(ap, char *);
348 info->description = desc;
349 }
350 break;
351 case SDB_PLUGIN_INFO_COPYRIGHT:
352 {
353 char *copyright = va_arg(ap, char *);
354 info->copyright = copyright;
355 }
356 break;
357 case SDB_PLUGIN_INFO_LICENSE:
358 {
359 char *license = va_arg(ap, char *);
360 info->license = license;
361 }
362 break;
363 case SDB_PLUGIN_INFO_VERSION:
364 {
365 int version = va_arg(ap, int);
366 info->version = version;
367 }
368 break;
369 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
370 {
371 int version = va_arg(ap, int);
372 info->plugin_version = version;
373 }
374 break;
375 default:
376 va_end(ap);
377 return -1;
378 }
380 va_end(ap);
381 return 0;
382 } /* sdb_plugin_set_info */
384 int
385 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
386 {
387 return sdb_plugin_add_callback(&config_list, "init", name,
388 callback, NULL);
389 } /* sdb_plugin_register_config */
391 int
392 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
393 sdb_object_t *user_data)
394 {
395 return sdb_plugin_add_callback(&init_list, "init", name,
396 callback, user_data);
397 } /* sdb_plugin_register_init */
399 int
400 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
401 sdb_object_t *user_data)
402 {
403 return sdb_plugin_add_callback(&shutdown_list, "shutdown", name,
404 callback, user_data);
405 } /* sdb_plugin_register_shutdown */
407 int
408 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
409 const sdb_time_t *interval, sdb_object_t *user_data)
410 {
411 sdb_object_t *obj;
413 if ((! name) || (! callback))
414 return -1;
416 if (! collector_list)
417 collector_list = sdb_llist_create();
418 if (! collector_list)
419 return -1;
421 obj = sdb_object_create(sizeof(sdb_plugin_collector_cb_t),
422 sdb_plugin_cb_init, sdb_plugin_cb_destroy,
423 &collector_list, "collector", name, callback, user_data);
424 if (! obj)
425 return -1;
427 if (interval)
428 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
429 else {
430 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
432 if (tmp > 0)
433 SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
434 else
435 SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
436 }
438 if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
439 char errbuf[1024];
440 sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
441 "time: %s\n", sdb_strerror(errno, errbuf, sizeof(errbuf)));
442 sdb_object_deref(obj);
443 return -1;
444 }
446 if (sdb_llist_insert_sorted(collector_list, obj,
447 sdb_plugin_cmp_next_update)) {
448 sdb_object_deref(obj);
449 return -1;
450 }
452 /* pass control to the list */
453 sdb_object_deref(obj);
455 sdb_log(SDB_LOG_INFO, "plugin: Registered collector callback '%s' "
456 "(interval = %.3fs).\n", name,
457 SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
458 return 0;
459 } /* sdb_plugin_register_collector */
461 sdb_plugin_ctx_t
462 sdb_plugin_get_ctx(void)
463 {
464 sdb_plugin_ctx_t *ctx;
466 if (! plugin_ctx_key_initialized)
467 sdb_plugin_ctx_init();
468 ctx = pthread_getspecific(plugin_ctx_key);
470 if (! ctx)
471 ctx = sdb_plugin_ctx_create();
472 if (! ctx)
473 return plugin_default_ctx;
474 return *ctx;
475 } /* sdb_plugin_get_ctx */
477 sdb_plugin_ctx_t
478 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx)
479 {
480 sdb_plugin_ctx_t *tmp;
481 sdb_plugin_ctx_t old;
483 if (! plugin_ctx_key_initialized)
484 sdb_plugin_ctx_init();
485 tmp = pthread_getspecific(plugin_ctx_key);
487 if (! tmp)
488 tmp = sdb_plugin_ctx_create();
489 if (! tmp)
490 return plugin_default_ctx;
492 old = *tmp;
493 *tmp = ctx;
494 return old;
495 } /* sdb_plugin_set_ctx */
497 int
498 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
499 {
500 sdb_plugin_cb_t *plugin;
501 sdb_plugin_config_cb callback;
503 sdb_plugin_ctx_t old_ctx;
505 int status;
507 if ((! name) || (! ci))
508 return -1;
510 plugin = sdb_plugin_find_by_name(config_list, name);
511 if (! plugin) {
512 /* XXX: check if any such plugin has been loaded */
513 sdb_log(SDB_LOG_ERR, "plugin: Plugin '%s' did not register "
514 "a config callback.\n", name);
515 errno = ENOENT;
516 return -1;
517 }
519 old_ctx = sdb_plugin_set_ctx(plugin->cb_ctx);
520 callback = plugin->cb_callback;
521 status = callback(ci);
522 sdb_plugin_set_ctx(old_ctx);
523 return status;
524 } /* sdb_plugin_configure */
526 int
527 sdb_plugin_init_all(void)
528 {
529 sdb_llist_iter_t *iter;
531 iter = sdb_llist_get_iter(init_list);
532 while (sdb_llist_iter_has_next(iter)) {
533 sdb_plugin_init_cb callback;
534 sdb_plugin_ctx_t old_ctx;
536 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
537 assert(obj);
539 callback = SDB_PLUGIN_CB(obj)->cb_callback;
541 old_ctx = sdb_plugin_set_ctx(SDB_PLUGIN_CB(obj)->cb_ctx);
542 if (callback(SDB_PLUGIN_CB(obj)->cb_user_data)) {
543 /* XXX: unload plugin */
544 }
545 sdb_plugin_set_ctx(old_ctx);
546 }
547 return 0;
548 } /* sdb_plugin_init_all */
550 int
551 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
552 {
553 if ((! collector_list) || (! loop))
554 return -1;
556 while (loop->do_loop) {
557 sdb_plugin_collector_cb callback;
558 sdb_plugin_ctx_t old_ctx;
560 sdb_time_t interval, now;
562 sdb_object_t *obj = sdb_llist_shift(collector_list);
563 if (! obj)
564 return -1;
566 callback = SDB_PLUGIN_CCB(obj)->ccb_callback;
568 if (! (now = sdb_gettime())) {
569 char errbuf[1024];
570 sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
571 "time: %s\n", sdb_strerror(errno, errbuf, sizeof(errbuf)));
572 now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
573 }
575 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
576 interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
578 errno = 0;
579 while (loop->do_loop && sdb_sleep(interval, &interval)) {
580 if (errno != EINTR) {
581 char errbuf[1024];
582 sdb_log(SDB_LOG_ERR, "plugin: Failed to sleep: %s\n",
583 sdb_strerror(errno, errbuf, sizeof(errbuf)));
584 return -1;
585 }
586 errno = 0;
587 }
589 if (! loop->do_loop)
590 return 0;
591 }
593 old_ctx = sdb_plugin_set_ctx(SDB_PLUGIN_CCB(obj)->ccb_ctx);
594 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
595 /* XXX */
596 }
597 sdb_plugin_set_ctx(old_ctx);
599 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
600 if (! interval)
601 interval = loop->default_interval;
602 if (! interval) {
603 sdb_log(SDB_LOG_WARNING, "plugin: No interval configured "
604 "for plugin '%s'; skipping any further "
605 "iterations.\n", SDB_PLUGIN_CCB(obj)->ccb_name);
606 sdb_object_deref(obj);
607 continue;
608 }
610 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
612 if (! (now = sdb_gettime())) {
613 char errbuf[1024];
614 sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
615 "time: %s\n", sdb_strerror(errno, errbuf, sizeof(errbuf)));
616 now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
617 }
619 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
620 sdb_log(SDB_LOG_WARNING, "plugin: Plugin '%s' took too "
621 "long; skipping iterations to keep up.\n",
622 SDB_PLUGIN_CCB(obj)->ccb_name);
623 SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
624 }
626 if (sdb_llist_insert_sorted(collector_list, obj,
627 sdb_plugin_cmp_next_update)) {
628 sdb_log(SDB_LOG_ERR, "plugin: Failed to re-insert "
629 "plugin '%s' into collector list. Unable to further "
630 "use the plugin.\n",
631 SDB_PLUGIN_CCB(obj)->ccb_name);
632 sdb_object_deref(obj);
633 return -1;
634 }
636 /* pass control back to the list */
637 sdb_object_deref(obj);
638 }
639 return 0;
640 } /* sdb_plugin_read_loop */
642 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */