Code

object system: Introduced a concept of types.
[sysdb.git] / src / core / plugin.c
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)
111         if (! ctx)
112                 return;
113         free(ctx);
114 } /* sdb_plugin_ctx_destructor */
116 static void
117 sdb_plugin_ctx_init(void)
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)
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)
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)
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)
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 /*
188  * private types
189  */
191 static int
192 sdb_plugin_cb_init(sdb_object_t *obj, va_list ap)
194         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
195         const char  *type = va_arg(ap, const char *);
196         const char  *name = va_arg(ap, const char *);
197         void    *callback = va_arg(ap, void *);
198         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
200         assert(list);
201         assert(type);
202         assert(obj);
204         if (sdb_plugin_find_by_name(*list, name)) {
205                 sdb_log(SDB_LOG_WARNING, "plugin: %s callback '%s' "
206                                 "has already been registered. Ignoring newly "
207                                 "registered version.", type, name);
208                 return -1;
209         }
211         snprintf(SDB_PLUGIN_CB(obj)->cb_name,
212                         sizeof(SDB_PLUGIN_CB(obj)->cb_name),
213                         "%s", name);
214         SDB_PLUGIN_CB(obj)->cb_name[sizeof(SDB_PLUGIN_CB(obj)->cb_name) - 1] = '\0';
215         SDB_PLUGIN_CB(obj)->cb_callback = callback;
216         SDB_PLUGIN_CB(obj)->cb_ctx      = sdb_plugin_get_ctx();
218         sdb_object_ref(ud);
219         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
220         return 0;
221 } /* sdb_plugin_cb_init */
223 static void
224 sdb_plugin_cb_destroy(sdb_object_t *obj)
226         assert(obj);
227         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
228 } /* sdb_plugin_cb_destroy */
230 static sdb_type_t sdb_plugin_cb_type = {
231         sizeof(sdb_plugin_cb_t),
233         sdb_plugin_cb_init,
234         sdb_plugin_cb_destroy
235 };
237 static sdb_type_t sdb_plugin_collector_cb_type = {
238         sizeof(sdb_plugin_collector_cb_t),
240         sdb_plugin_cb_init,
241         sdb_plugin_cb_destroy
242 };
244 static int
245 sdb_plugin_add_callback(sdb_llist_t **list, const char *type,
246                 const char *name, void *callback, sdb_object_t *user_data)
248         sdb_object_t *obj;
250         if ((! name) || (! callback))
251                 return -1;
253         assert(list);
255         if (! *list)
256                 *list = sdb_llist_create();
257         if (! *list)
258                 return -1;
260         obj = sdb_object_create(sdb_plugin_cb_type,
261                         list, type, name, callback, user_data);
262         if (! obj)
263                 return -1;
265         if (sdb_llist_append(*list, obj)) {
266                 sdb_object_deref(obj);
267                 return -1;
268         }
270         /* pass control to the list */
271         sdb_object_deref(obj);
273         sdb_log(SDB_LOG_INFO, "plugin: Registered %s callback '%s'.",
274                         type, name);
275         return 0;
276 } /* sdb_plugin_add_callback */
278 /*
279  * public API
280  */
282 int
283 sdb_plugin_load(const char *name)
285         char  real_name[strlen(name) > 0 ? strlen(name) : 1];
286         const char *name_ptr;
287         char *tmp;
289         char filename[1024];
291         lt_dlhandle lh;
293         int (*mod_init)(sdb_plugin_info_t *);
294         sdb_plugin_info_t plugin_info = SDB_PLUGIN_INFO_INIT;
296         int status;
298         if ((! name) || (! *name))
299                 return -1;
301         real_name[0] = '\0';
302         name_ptr = name;
304         while ((tmp = strstr(name_ptr, "::"))) {
305                 strncat(real_name, name_ptr, (size_t)(tmp - name_ptr));
306                 strcat(real_name, "/");
307                 name_ptr = tmp + strlen("::");
308         }
309         strcat(real_name, name_ptr);
311         snprintf(filename, sizeof(filename), "%s/%s.so",
312                         PKGLIBDIR, real_name);
313         filename[sizeof(filename) - 1] = '\0';
315         if (access(filename, R_OK)) {
316                 char errbuf[1024];
317                 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s' (%s): %s",
318                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
319                 return -1;
320         }
322         lt_dlinit();
323         lt_dlerror();
325         lh = lt_dlopen(filename);
326         if (! lh) {
327                 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s': %s"
328                                 "The most common cause for this problem are missing "
329                                 "dependencies.\n", name, lt_dlerror());
330                 return -1;
331         }
333         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
334         if (! mod_init) {
335                 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s': "
336                                 "could not find symbol 'sdb_module_init'", name);
337                 return -1;
338         }
340         status = mod_init(&plugin_info);
341         if (status) {
342                 sdb_log(SDB_LOG_ERR, "plugin: Failed to initialize "
343                                 "plugin '%s'", name);
344                 return -1;
345         }
347         /* compare minor version */
348         if ((plugin_info.version < 0)
349                         || ((int)(plugin_info.version / 100) != (int)(SDB_VERSION / 100)))
350                 sdb_log(SDB_LOG_WARNING, "plugin: WARNING: version of "
351                                 "plugin '%s' (%i.%i.%i) does not match our version "
352                                 "(%i.%i.%i); this might cause problems",
353                                 name, SDB_VERSION_DECODE(plugin_info.version),
354                                 SDB_VERSION_DECODE(SDB_VERSION));
356         sdb_log(SDB_LOG_INFO, "plugin: Successfully loaded "
357                         "plugin '%s' v%i (%s)\n\t%s",
358                         plugin_info.name, plugin_info.plugin_version,
359                         plugin_info.description, plugin_info.copyright);
360         return 0;
361 } /* sdb_plugin_load */
363 int
364 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
366         va_list ap;
368         if (! info)
369                 return -1;
371         va_start(ap, type);
373         switch (type) {
374                 case SDB_PLUGIN_INFO_NAME:
375                         {
376                                 char *name = va_arg(ap, char *);
377                                 info->name = name;
378                         }
379                         break;
380                 case SDB_PLUGIN_INFO_DESC:
381                         {
382                                 char *desc = va_arg(ap, char *);
383                                 info->description = desc;
384                         }
385                         break;
386                 case SDB_PLUGIN_INFO_COPYRIGHT:
387                         {
388                                 char *copyright = va_arg(ap, char *);
389                                 info->copyright = copyright;
390                         }
391                         break;
392                 case SDB_PLUGIN_INFO_LICENSE:
393                         {
394                                 char *license = va_arg(ap, char *);
395                                 info->license = license;
396                         }
397                         break;
398                 case SDB_PLUGIN_INFO_VERSION:
399                         {
400                                 int version = va_arg(ap, int);
401                                 info->version = version;
402                         }
403                         break;
404                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
405                         {
406                                 int version = va_arg(ap, int);
407                                 info->plugin_version = version;
408                         }
409                         break;
410                 default:
411                         va_end(ap);
412                         return -1;
413         }
415         va_end(ap);
416         return 0;
417 } /* sdb_plugin_set_info */
419 int
420 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
422         return sdb_plugin_add_callback(&config_list, "init", name,
423                         callback, NULL);
424 } /* sdb_plugin_register_config */
426 int
427 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
428                 sdb_object_t *user_data)
430         return sdb_plugin_add_callback(&init_list, "init", name,
431                         callback, user_data);
432 } /* sdb_plugin_register_init */
434 int
435 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
436                 sdb_object_t *user_data)
438         return sdb_plugin_add_callback(&shutdown_list, "shutdown", name,
439                         callback, user_data);
440 } /* sdb_plugin_register_shutdown */
442 int
443 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
444                 const sdb_time_t *interval, sdb_object_t *user_data)
446         sdb_object_t *obj;
448         if ((! name) || (! callback))
449                 return -1;
451         if (! collector_list)
452                 collector_list = sdb_llist_create();
453         if (! collector_list)
454                 return -1;
456         obj = sdb_object_create(sdb_plugin_collector_cb_type,
457                         &collector_list, "collector", name, callback, user_data);
458         if (! obj)
459                 return -1;
461         if (interval)
462                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
463         else {
464                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
466                 if (tmp > 0)
467                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
468                 else
469                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
470         }
472         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
473                 char errbuf[1024];
474                 sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
475                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
476                 sdb_object_deref(obj);
477                 return -1;
478         }
480         if (sdb_llist_insert_sorted(collector_list, obj,
481                                 sdb_plugin_cmp_next_update)) {
482                 sdb_object_deref(obj);
483                 return -1;
484         }
486         /* pass control to the list */
487         sdb_object_deref(obj);
489         sdb_log(SDB_LOG_INFO, "plugin: Registered collector callback '%s' "
490                         "(interval = %.3fs).", name,
491                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
492         return 0;
493 } /* sdb_plugin_register_collector */
495 sdb_plugin_ctx_t
496 sdb_plugin_get_ctx(void)
498         sdb_plugin_ctx_t *ctx;
500         if (! plugin_ctx_key_initialized)
501                 sdb_plugin_ctx_init();
502         ctx = pthread_getspecific(plugin_ctx_key);
504         if (! ctx)
505                 ctx = sdb_plugin_ctx_create();
506         if (! ctx)
507                 return plugin_default_ctx;
508         return *ctx;
509 } /* sdb_plugin_get_ctx */
511 sdb_plugin_ctx_t
512 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx)
514         sdb_plugin_ctx_t *tmp;
515         sdb_plugin_ctx_t old;
517         if (! plugin_ctx_key_initialized)
518                 sdb_plugin_ctx_init();
519         tmp = pthread_getspecific(plugin_ctx_key);
521         if (! tmp)
522                 tmp = sdb_plugin_ctx_create();
523         if (! tmp)
524                 return plugin_default_ctx;
526         old = *tmp;
527         *tmp = ctx;
528         return old;
529 } /* sdb_plugin_set_ctx */
531 int
532 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
534         sdb_plugin_cb_t *plugin;
535         sdb_plugin_config_cb callback;
537         sdb_plugin_ctx_t old_ctx;
539         int status;
541         if ((! name) || (! ci))
542                 return -1;
544         plugin = sdb_plugin_find_by_name(config_list, name);
545         if (! plugin) {
546                 /* XXX: check if any such plugin has been loaded */
547                 sdb_log(SDB_LOG_ERR, "plugin: Plugin '%s' did not register "
548                                 "a config callback.", name);
549                 errno = ENOENT;
550                 return -1;
551         }
553         old_ctx = sdb_plugin_set_ctx(plugin->cb_ctx);
554         callback = plugin->cb_callback;
555         status = callback(ci);
556         sdb_plugin_set_ctx(old_ctx);
557         return status;
558 } /* sdb_plugin_configure */
560 int
561 sdb_plugin_init_all(void)
563         sdb_llist_iter_t *iter;
565         iter = sdb_llist_get_iter(init_list);
566         while (sdb_llist_iter_has_next(iter)) {
567                 sdb_plugin_init_cb callback;
568                 sdb_plugin_ctx_t old_ctx;
570                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
571                 assert(obj);
573                 callback = SDB_PLUGIN_CB(obj)->cb_callback;
575                 old_ctx = sdb_plugin_set_ctx(SDB_PLUGIN_CB(obj)->cb_ctx);
576                 if (callback(SDB_PLUGIN_CB(obj)->cb_user_data)) {
577                         /* XXX: unload plugin */
578                 }
579                 sdb_plugin_set_ctx(old_ctx);
580         }
581         return 0;
582 } /* sdb_plugin_init_all */
584 int
585 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
587         if (! collector_list) {
588                 sdb_log(SDB_LOG_WARNING, "plugin: No collectors registered. "
589                                 "Quiting main loop.");
590                 return -1;
591         }
593         if (! loop)
594                 return -1;
596         while (loop->do_loop) {
597                 sdb_plugin_collector_cb callback;
598                 sdb_plugin_ctx_t old_ctx;
600                 sdb_time_t interval, now;
602                 sdb_object_t *obj = sdb_llist_shift(collector_list);
603                 if (! obj)
604                         return -1;
606                 callback = SDB_PLUGIN_CCB(obj)->ccb_callback;
608                 if (! (now = sdb_gettime())) {
609                         char errbuf[1024];
610                         sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
611                                         "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
612                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
613                 }
615                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
616                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
618                         errno = 0;
619                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
620                                 if (errno != EINTR) {
621                                         char errbuf[1024];
622                                         sdb_log(SDB_LOG_ERR, "plugin: Failed to sleep: %s",
623                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
624                                         return -1;
625                                 }
626                                 errno = 0;
627                         }
629                         if (! loop->do_loop)
630                                 return 0;
631                 }
633                 old_ctx = sdb_plugin_set_ctx(SDB_PLUGIN_CCB(obj)->ccb_ctx);
634                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
635                         /* XXX */
636                 }
637                 sdb_plugin_set_ctx(old_ctx);
639                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
640                 if (! interval)
641                         interval = loop->default_interval;
642                 if (! interval) {
643                         sdb_log(SDB_LOG_WARNING, "plugin: No interval configured "
644                                         "for plugin '%s'; skipping any further "
645                                         "iterations.", SDB_PLUGIN_CCB(obj)->ccb_name);
646                         sdb_object_deref(obj);
647                         continue;
648                 }
650                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
652                 if (! (now = sdb_gettime())) {
653                         char errbuf[1024];
654                         sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
655                                         "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
656                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
657                 }
659                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
660                         sdb_log(SDB_LOG_WARNING, "plugin: Plugin '%s' took too "
661                                         "long; skipping iterations to keep up.",
662                                         SDB_PLUGIN_CCB(obj)->ccb_name);
663                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
664                 }
666                 if (sdb_llist_insert_sorted(collector_list, obj,
667                                         sdb_plugin_cmp_next_update)) {
668                         sdb_log(SDB_LOG_ERR, "plugin: Failed to re-insert "
669                                         "plugin '%s' into collector list. Unable to further "
670                                         "use the plugin.",
671                                         SDB_PLUGIN_CCB(obj)->ccb_name);
672                         sdb_object_deref(obj);
673                         return -1;
674                 }
676                 /* pass control back to the list */
677                 sdb_object_deref(obj);
678         }
679         return 0;
680 } /* sdb_plugin_read_loop */
682 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */