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  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "sysdb.h"
  33 #include "core/plugin.h"
  34 #include "core/time.h"
  35 #include "utils/error.h"
  36 #include "utils/llist.h"
  37 #include "utils/strbuf.h"
  38
  39 #include <assert.h>
  40
  41 #include <errno.h>
  42
  43 #include <stdarg.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <strings.h>
  47 #include <unistd.h>
  48
  49 #include <ltdl.h>
  50
  51 #include <pthread.h>
  52
  53 /*
  54  * private data types
  55  */
  56
  57 struct sdb_plugin_info {
  58         char *plugin_name;
  59         char *filename;
  60
  61         /* public attributes */
  62         char *name;
  63
  64         char *description;
  65         char *copyright;
  66         char *license;
  67
  68         int   version;
  69         int   plugin_version;
  70 };
  71 #define SDB_PLUGIN_INFO_INIT { \
  72         /* plugin_name */ NULL, /* filename */ NULL, \
  73         /* name */ NULL, /* desc */ NULL, \
  74         /* copyright */ NULL, /* license */ NULL, \
  75         /* version */ -1, /* plugin_version */ -1 }
  76 #define INFO_GET(i, attr) \
  77         ((i)->attr ? (i)->attr : #attr" not set")
  78
  79 typedef struct {
  80         sdb_object_t super;
  81         sdb_plugin_ctx_t public;
  82
  83         sdb_plugin_info_t info;
  84         lt_dlhandle handle;
  85
  86         /* The usage count differs from the object's ref count
  87          * in that it provides higher level information about how
  88          * the plugin is in use. */
  89         size_t use_cnt;
  90 } ctx_t;
  91 #define CTX_INIT { SDB_OBJECT_INIT, \
  92         SDB_PLUGIN_CTX_INIT, SDB_PLUGIN_INFO_INIT, NULL, 0 }
  93
  94 #define CTX(obj) ((ctx_t *)(obj))
  95
  96 typedef struct {
  97         sdb_object_t super;
  98         void *cb_callback;
  99         sdb_object_t *cb_user_data;
 100         ctx_t *cb_ctx;
 101 } sdb_plugin_cb_t;
 102 #define SDB_PLUGIN_CB_INIT { SDB_OBJECT_INIT, \
 103         /* callback = */ NULL, /* user_data = */ NULL, \
 104         SDB_PLUGIN_CTX_INIT }
 105
 106 typedef struct {
 107         sdb_plugin_cb_t super;
 108 #define ccb_callback super.cb_callback
 109 #define ccb_user_data super.cb_user_data
 110 #define ccb_ctx super.cb_ctx
 111         sdb_time_t ccb_interval;
 112         sdb_time_t ccb_next_update;
 113 } sdb_plugin_collector_cb_t;
 114
 115 #define SDB_PLUGIN_CB(obj) ((sdb_plugin_cb_t *)(obj))
 116 #define SDB_CONST_PLUGIN_CB(obj) ((const sdb_plugin_cb_t *)(obj))
 117 #define SDB_PLUGIN_CCB(obj) ((sdb_plugin_collector_cb_t *)(obj))
 118 #define SDB_CONST_PLUGIN_CCB(obj) ((const sdb_plugin_collector_cb_t *)(obj))
 119
 120 /*
 121  * private variables
 122  */
 123
 124 static sdb_plugin_ctx_t  plugin_default_ctx  = SDB_PLUGIN_CTX_INIT;
 125 static sdb_plugin_info_t plugin_default_info = SDB_PLUGIN_INFO_INIT;
 126
 127 static pthread_key_t     plugin_ctx_key;
 128 static _Bool             plugin_ctx_key_initialized = 0;
 129
 130 /* a list of the plugin contexts of all registered plugins */
 131 static sdb_llist_t      *all_plugins = NULL;
 132
 133 static sdb_llist_t      *config_list = NULL;
 134 static sdb_llist_t      *init_list = NULL;
 135 static sdb_llist_t      *collector_list = NULL;
 136 static sdb_llist_t      *cname_list = NULL;
 137 static sdb_llist_t      *shutdown_list = NULL;
 138 static sdb_llist_t      *log_list = NULL;
 139
 140 /*
 141  * private helper functions
 142  */
 143
 144 static void
 145 plugin_info_clear(sdb_plugin_info_t *info)
 146 {
 147         sdb_plugin_info_t empty_info = SDB_PLUGIN_INFO_INIT;
 148         if (! info)
 149                 return;
 150
 151         if (info->plugin_name)
 152                 free(info->plugin_name);
 153         if (info->filename)
 154                 free(info->filename);
 155
 156         if (info->name)
 157                 free(info->name);
 158         if (info->description)
 159                 free(info->description);
 160         if (info->copyright)
 161                 free(info->copyright);
 162         if (info->license)
 163                 free(info->license);
 164
 165         *info = empty_info;
 166 } /* plugin_info_clear */
 167
 168 static void
 169 ctx_key_init(void)
 170 {
 171         if (plugin_ctx_key_initialized)
 172                 return;
 173
 174         pthread_key_create(&plugin_ctx_key, /* destructor */ NULL);
 175         plugin_ctx_key_initialized = 1;
 176 } /* ctx_key_init */
 177
 178 static int
 179 plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
 180 {
 181         const sdb_plugin_collector_cb_t *ccb1
 182                 = (const sdb_plugin_collector_cb_t *)a;
 183         const sdb_plugin_collector_cb_t *ccb2
 184                 = (const sdb_plugin_collector_cb_t *)b;
 185
 186         assert(ccb1 && ccb2);
 187
 188         return (ccb1->ccb_next_update > ccb2->ccb_next_update)
 189                 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
 190                 ? -1 : 0;
 191 } /* plugin_cmp_next_update */
 192
 193 static int
 194 plugin_lookup_by_name(const sdb_object_t *obj, const void *id)
 195 {
 196         const sdb_plugin_cb_t *cb = SDB_CONST_PLUGIN_CB(obj);
 197         const char *name = id;
 198
 199         assert(cb && id && cb->cb_ctx);
 200         if (!strcasecmp(cb->cb_ctx->info.plugin_name, name))
 201                 return 0;
 202         return 1;
 203 } /* plugin_lookup_by_name */
 204
 205 static void
 206 plugin_unregister_by_name(const char *plugin_name)
 207 {
 208         sdb_object_t *obj;
 209         size_t i;
 210
 211         struct {
 212                 const char  *type;
 213                 sdb_llist_t *list;
 214         } all_lists[] = {
 215                 { "config",    config_list },
 216                 { "init",      init_list },
 217                 { "collector", collector_list },
 218                 { "cname",     cname_list },
 219                 { "shutdown",  shutdown_list },
 220                 { "log",       log_list },
 221         };
 222
 223         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 224                 const char  *type = all_lists[i].type;
 225                 sdb_llist_t *list = all_lists[i].list;
 226
 227                 while (1) {
 228                         sdb_plugin_cb_t *cb;
 229
 230                         cb = SDB_PLUGIN_CB(sdb_llist_remove(list,
 231                                                 plugin_lookup_by_name, plugin_name));
 232                         if (! cb)
 233                                 break;
 234
 235                         sdb_log(SDB_LOG_INFO, "core: Unregistering "
 236                                         "%s callback '%s' (module %s)", type, cb->super.name,
 237                                         cb->cb_ctx->info.plugin_name);
 238                         sdb_object_deref(SDB_OBJ(cb));
 239                 }
 240         }
 241
 242         obj = sdb_llist_search_by_name(all_plugins, plugin_name);
 243         if (obj->ref_cnt <= 1)
 244                 sdb_llist_remove_by_name(all_plugins, plugin_name);
 245         /* else: other callbacks still reference it */
 246         sdb_object_deref(obj);
 247 } /* plugin_unregister_by_name */
 248
 249 /*
 250  * private types
 251  */
 252
 253 static int
 254 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 255 {
 256         ctx_t *ctx = CTX(obj);
 257
 258         assert(ctx);
 259
 260         ctx->public = plugin_default_ctx;
 261         ctx->info = plugin_default_info;
 262         ctx->handle = NULL;
 263         ctx->use_cnt = 1;
 264         return 0;
 265 } /* ctx_init */
 266
 267 static void
 268 ctx_destroy(sdb_object_t *obj)
 269 {
 270         ctx_t *ctx = CTX(obj);
 271
 272         if (ctx->handle) {
 273                 const char *err;
 274
 275                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s",
 276                                 ctx->info.plugin_name);
 277
 278                 lt_dlerror();
 279                 lt_dlclose(ctx->handle);
 280                 if ((err = lt_dlerror()))
 281                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload module %s: %s",
 282                                         ctx->info.plugin_name, err);
 283         }
 284
 285         plugin_info_clear(&ctx->info);
 286 } /* ctx_destroy */
 287
 288 static sdb_type_t ctx_type = {
 289         sizeof(ctx_t),
 290
 291         ctx_init,
 292         ctx_destroy
 293 };
 294
 295 static ctx_t *
 296 ctx_create(const char *name)
 297 {
 298         ctx_t *ctx;
 299
 300         ctx = CTX(sdb_object_create(name, ctx_type));
 301         if (! ctx)
 302                 return NULL;
 303
 304         if (! plugin_ctx_key_initialized)
 305                 ctx_key_init();
 306         sdb_object_ref(SDB_OBJ(ctx));
 307         pthread_setspecific(plugin_ctx_key, ctx);
 308         return ctx;
 309 } /* ctx_create */
 310
 311 static ctx_t *
 312 ctx_get(void)
 313 {
 314         if (! plugin_ctx_key_initialized)
 315                 ctx_key_init();
 316         return pthread_getspecific(plugin_ctx_key);
 317 } /* ctx_get */
 318
 319 static ctx_t *
 320 ctx_set(ctx_t *new)
 321 {
 322         ctx_t *old;
 323
 324         if (! plugin_ctx_key_initialized)
 325                 ctx_key_init();
 326
 327         old = pthread_getspecific(plugin_ctx_key);
 328         if (old)
 329                 sdb_object_deref(SDB_OBJ(old));
 330         if (new)
 331                 sdb_object_ref(SDB_OBJ(new));
 332         pthread_setspecific(plugin_ctx_key, new);
 333         return old;
 334 } /* ctx_set */
 335
 336 static int
 337 plugin_cb_init(sdb_object_t *obj, va_list ap)
 338 {
 339         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 340         const char   *type = va_arg(ap, const char *);
 341         void     *callback = va_arg(ap, void *);
 342         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 343
 344         assert(list);
 345         assert(type);
 346         assert(obj);
 347
 348         if (sdb_llist_search_by_name(*list, obj->name)) {
 349                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 350                                 "has already been registered. Ignoring newly "
 351                                 "registered version.", type, obj->name);
 352                 return -1;
 353         }
 354
 355         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 356         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 357         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 358
 359         sdb_object_ref(ud);
 360         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 361         return 0;
 362 } /* plugin_cb_init */
 363
 364 static void
 365 plugin_cb_destroy(sdb_object_t *obj)
 366 {
 367         assert(obj);
 368         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 369         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 370 } /* plugin_cb_destroy */
 371
 372 static sdb_type_t sdb_plugin_cb_type = {
 373         sizeof(sdb_plugin_cb_t),
 374
 375         plugin_cb_init,
 376         plugin_cb_destroy
 377 };
 378
 379 static sdb_type_t sdb_plugin_collector_cb_type = {
 380         sizeof(sdb_plugin_collector_cb_t),
 381
 382         plugin_cb_init,
 383         plugin_cb_destroy
 384 };
 385
 386 static int
 387 module_init(const char *name, lt_dlhandle lh, sdb_plugin_info_t *info)
 388 {
 389         int (*mod_init)(sdb_plugin_info_t *);
 390         int status;
 391
 392         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 393         if (! mod_init) {
 394                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 395                                 "could not find symbol 'sdb_module_init'", name);
 396                 return -1;
 397         }
 398
 399         status = mod_init(info);
 400         if (status) {
 401                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 402                                 "module '%s'", name);
 403                 plugin_unregister_by_name(name);
 404                 return -1;
 405         }
 406         return 0;
 407 } /* module_init */
 408
 409 static int
 410 module_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 411 {
 412         char  base_name[name ? strlen(name) + 1 : 1];
 413         const char *name_ptr;
 414         char *tmp;
 415
 416         char filename[1024];
 417         lt_dlhandle lh;
 418
 419         ctx_t *ctx;
 420
 421         int status;
 422
 423         base_name[0] = '\0';
 424         name_ptr = name;
 425
 426         while ((tmp = strstr(name_ptr, "::"))) {
 427                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 428                 strcat(base_name, "/");
 429                 name_ptr = tmp + strlen("::");
 430         }
 431         strcat(base_name, name_ptr);
 432
 433         snprintf(filename, sizeof(filename), "%s/%s.so",
 434                         PKGLIBDIR, base_name);
 435         filename[sizeof(filename) - 1] = '\0';
 436
 437         if (access(filename, R_OK)) {
 438                 char errbuf[1024];
 439                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 440                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 441                 return -1;
 442         }
 443
 444         lt_dlinit();
 445         lt_dlerror();
 446
 447         lh = lt_dlopen(filename);
 448         if (! lh) {
 449                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 450                                 "The most common cause for this problem are missing "
 451                                 "dependencies.\n", name, lt_dlerror());
 452                 return -1;
 453         }
 454
 455         if (ctx_get())
 456                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 457
 458         ctx = ctx_create(name);
 459         if (! ctx) {
 460                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 461                 return -1;
 462         }
 463
 464         ctx->info.plugin_name = strdup(name);
 465         ctx->info.filename = strdup(filename);
 466         ctx->handle = lh;
 467
 468         if (plugin_ctx)
 469                 ctx->public = *plugin_ctx;
 470
 471         if ((status = module_init(name, lh, &ctx->info))) {
 472                 sdb_object_deref(SDB_OBJ(ctx));
 473                 return status;
 474         }
 475
 476         /* compare minor version */
 477         if ((ctx->info.version < 0)
 478                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 479                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 480                                 "plugin '%s' (%i.%i.%i) does not match our version "
 481                                 "(%i.%i.%i); this might cause problems",
 482                                 name, SDB_VERSION_DECODE(ctx->info.version),
 483                                 SDB_VERSION_DECODE(SDB_VERSION));
 484
 485         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 486
 487         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 488                         "plugin '%s' v%i (%s)\n\t%s\n\tLicense: %s",
 489                         INFO_GET(&ctx->info, name), ctx->info.plugin_version,
 490                         INFO_GET(&ctx->info, description),
 491                         INFO_GET(&ctx->info, copyright),
 492                         INFO_GET(&ctx->info, license));
 493
 494         /* any registered callbacks took ownership of the context */
 495         sdb_object_deref(SDB_OBJ(ctx));
 496
 497         /* reset */
 498         ctx_set(NULL);
 499         return 0;
 500 } /* module_load */
 501
 502 static int
 503 plugin_add_callback(sdb_llist_t **list, const char *type,
 504                 const char *name, void *callback, sdb_object_t *user_data)
 505 {
 506         sdb_object_t *obj;
 507
 508         if ((! name) || (! callback))
 509                 return -1;
 510
 511         assert(list);
 512
 513         if (! *list)
 514                 *list = sdb_llist_create();
 515         if (! *list)
 516                 return -1;
 517
 518         obj = sdb_object_create(name, sdb_plugin_cb_type,
 519                         list, type, callback, user_data);
 520         if (! obj)
 521                 return -1;
 522
 523         if (sdb_llist_append(*list, obj)) {
 524                 sdb_object_deref(obj);
 525                 return -1;
 526         }
 527
 528         /* pass control to the list */
 529         sdb_object_deref(obj);
 530
 531         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 532                         type, name);
 533         return 0;
 534 } /* plugin_add_callback */
 535
 536 /*
 537  * public API
 538  */
 539
 540 int
 541 sdb_plugin_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 542 {
 543         ctx_t *ctx;
 544
 545         if ((! name) || (! *name))
 546                 return -1;
 547
 548         if (! all_plugins) {
 549                 if (! (all_plugins = sdb_llist_create())) {
 550                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 551                                         "internal error while creating linked list", name);
 552                         return -1;
 553                 }
 554         }
 555
 556         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 557         if (ctx) {
 558                 /* plugin already loaded */
 559                 ++ctx->use_cnt;
 560                 return 0;
 561         }
 562
 563         return module_load(name, plugin_ctx);
 564 } /* sdb_plugin_load */
 565
 566 int
 567 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 568 {
 569         va_list ap;
 570
 571         if (! info)
 572                 return -1;
 573
 574         va_start(ap, type);
 575
 576         switch (type) {
 577                 case SDB_PLUGIN_INFO_NAME:
 578                         {
 579                                 char *name = va_arg(ap, char *);
 580                                 if (name) {
 581                                         if (info->name)
 582                                                 free(info->name);
 583                                         info->name = strdup(name);
 584                                 }
 585                         }
 586                         break;
 587                 case SDB_PLUGIN_INFO_DESC:
 588                         {
 589                                 char *desc = va_arg(ap, char *);
 590                                 if (desc) {
 591                                         if (info->description)
 592                                                 free(info->description);
 593                                         info->description = strdup(desc);
 594                                 }
 595                         }
 596                         break;
 597                 case SDB_PLUGIN_INFO_COPYRIGHT:
 598                         {
 599                                 char *copyright = va_arg(ap, char *);
 600                                 if (copyright)
 601                                         info->copyright = strdup(copyright);
 602                         }
 603                         break;
 604                 case SDB_PLUGIN_INFO_LICENSE:
 605                         {
 606                                 char *license = va_arg(ap, char *);
 607                                 if (license) {
 608                                         if (info->license)
 609                                                 free(info->license);
 610                                         info->license = strdup(license);
 611                                 }
 612                         }
 613                         break;
 614                 case SDB_PLUGIN_INFO_VERSION:
 615                         {
 616                                 int version = va_arg(ap, int);
 617                                 info->version = version;
 618                         }
 619                         break;
 620                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 621                         {
 622                                 int version = va_arg(ap, int);
 623                                 info->plugin_version = version;
 624                         }
 625                         break;
 626                 default:
 627                         va_end(ap);
 628                         return -1;
 629         }
 630
 631         va_end(ap);
 632         return 0;
 633 } /* sdb_plugin_set_info */
 634
 635 int
 636 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
 637 {
 638         return plugin_add_callback(&config_list, "init", name,
 639                         (void *)callback, NULL);
 640 } /* sdb_plugin_register_config */
 641
 642 int
 643 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 644                 sdb_object_t *user_data)
 645 {
 646         return plugin_add_callback(&init_list, "init", name,
 647                         (void *)callback, user_data);
 648 } /* sdb_plugin_register_init */
 649
 650 int
 651 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 652                 sdb_object_t *user_data)
 653 {
 654         return plugin_add_callback(&shutdown_list, "shutdown", name,
 655                         (void *)callback, user_data);
 656 } /* sdb_plugin_register_shutdown */
 657
 658 int
 659 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 660                 sdb_object_t *user_data)
 661 {
 662         return plugin_add_callback(&log_list, "log", name, (void *)callback,
 663                         user_data);
 664 } /* sdb_plugin_register_log */
 665
 666 int
 667 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 668                 sdb_object_t *user_data)
 669 {
 670         return plugin_add_callback(&cname_list, "cname", name, (void *)callback,
 671                         user_data);
 672 } /* sdb_plugin_register_cname */
 673
 674 int
 675 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 676                 const sdb_time_t *interval, sdb_object_t *user_data)
 677 {
 678         sdb_object_t *obj;
 679
 680         if ((! name) || (! callback))
 681                 return -1;
 682
 683         if (! collector_list)
 684                 collector_list = sdb_llist_create();
 685         if (! collector_list)
 686                 return -1;
 687
 688         obj = sdb_object_create(name, sdb_plugin_collector_cb_type,
 689                         &collector_list, "collector", callback, user_data);
 690         if (! obj)
 691                 return -1;
 692
 693         if (interval)
 694                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 695         else {
 696                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 697
 698                 if (tmp > 0)
 699                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 700                 else
 701                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 702         }
 703
 704         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 705                 char errbuf[1024];
 706                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 707                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 708                 sdb_object_deref(obj);
 709                 return -1;
 710         }
 711
 712         if (sdb_llist_insert_sorted(collector_list, obj,
 713                                 plugin_cmp_next_update)) {
 714                 sdb_object_deref(obj);
 715                 return -1;
 716         }
 717
 718         /* pass control to the list */
 719         sdb_object_deref(obj);
 720
 721         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 722                         "(interval = %.3fs).", name,
 723                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 724         return 0;
 725 } /* sdb_plugin_register_collector */
 726
 727 sdb_plugin_ctx_t
 728 sdb_plugin_get_ctx(void)
 729 {
 730         ctx_t *c;
 731
 732         c = ctx_get();
 733         if (! c) {
 734                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 735                                 "context outside a plugin");
 736                 return plugin_default_ctx;
 737         }
 738         return c->public;
 739 } /* sdb_plugin_get_ctx */
 740
 741 int
 742 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 743 {
 744         ctx_t *c;
 745
 746         c = ctx_get();
 747         if (! c) {
 748                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 749                                 "context outside a plugin");
 750                 return -1;
 751         }
 752
 753         if (old)
 754                 *old = c->public;
 755         c->public = ctx;
 756         return 0;
 757 } /* sdb_plugin_set_ctx */
 758
 759 int
 760 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 761 {
 762         sdb_plugin_cb_t *plugin;
 763         sdb_plugin_config_cb callback;
 764
 765         ctx_t *old_ctx;
 766
 767         int status;
 768
 769         if ((! name) || (! ci))
 770                 return -1;
 771
 772         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 773         if (! plugin) {
 774                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 775                 if (! ctx)
 776                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' not loaded.", name);
 777                 else
 778                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 779                                         "a config callback.", name);
 780                 errno = ENOENT;
 781                 return -1;
 782         }
 783
 784         old_ctx = ctx_set(plugin->cb_ctx);
 785         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 786         status = callback(ci);
 787         ctx_set(old_ctx);
 788         return status;
 789 } /* sdb_plugin_configure */
 790
 791 int
 792 sdb_plugin_init_all(void)
 793 {
 794         sdb_llist_iter_t *iter;
 795         int ret = 0;
 796
 797         iter = sdb_llist_get_iter(init_list);
 798         while (sdb_llist_iter_has_next(iter)) {
 799                 sdb_plugin_cb_t *cb;
 800                 sdb_plugin_init_cb callback;
 801                 ctx_t *old_ctx;
 802
 803                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 804                 assert(obj);
 805                 cb = SDB_PLUGIN_CB(obj);
 806
 807                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 808
 809                 old_ctx = ctx_set(cb->cb_ctx);
 810                 if (callback(cb->cb_user_data)) {
 811                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 812                                         "'%s'. Unregistering all callbacks.", obj->name);
 813                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 814                         ++ret;
 815                 }
 816                 ctx_set(old_ctx);
 817         }
 818         sdb_llist_iter_destroy(iter);
 819         return ret;
 820 } /* sdb_plugin_init_all */
 821
 822 int
 823 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 824 {
 825         if (! collector_list) {
 826                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 827                                 "Quiting main loop.");
 828                 return -1;
 829         }
 830
 831         if (! loop)
 832                 return -1;
 833
 834         while (loop->do_loop) {
 835                 sdb_plugin_collector_cb callback;
 836                 ctx_t *old_ctx;
 837
 838                 sdb_time_t interval, now;
 839
 840                 sdb_object_t *obj = sdb_llist_shift(collector_list);
 841                 if (! obj)
 842                         return -1;
 843
 844                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
 845
 846                 if (! (now = sdb_gettime())) {
 847                         char errbuf[1024];
 848                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 849                                         "time in collector main loop: %s",
 850                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 851                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 852                 }
 853
 854                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 855                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
 856
 857                         errno = 0;
 858                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
 859                                 if (errno != EINTR) {
 860                                         char errbuf[1024];
 861                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
 862                                                         "in collector main loop: %s",
 863                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 864                                         return -1;
 865                                 }
 866                                 errno = 0;
 867                         }
 868
 869                         if (! loop->do_loop)
 870                                 return 0;
 871                 }
 872
 873                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
 874                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
 875                         /* XXX */
 876                 }
 877                 ctx_set(old_ctx);
 878
 879                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
 880                 if (! interval)
 881                         interval = loop->default_interval;
 882                 if (! interval) {
 883                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
 884                                         "for plugin '%s'; skipping any further "
 885                                         "iterations.", obj->name);
 886                         sdb_object_deref(obj);
 887                         continue;
 888                 }
 889
 890                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
 891
 892                 if (! (now = sdb_gettime())) {
 893                         char errbuf[1024];
 894                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 895                                         "time in collector main loop: %s",
 896                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 897                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 898                 }
 899
 900                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 901                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
 902                                         "long; skipping iterations to keep up.",
 903                                         obj->name);
 904                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
 905                 }
 906
 907                 if (sdb_llist_insert_sorted(collector_list, obj,
 908                                         plugin_cmp_next_update)) {
 909                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
 910                                         "plugin '%s' into collector list. Unable to further "
 911                                         "use the plugin.",
 912                                         obj->name);
 913                         sdb_object_deref(obj);
 914                         return -1;
 915                 }
 916
 917                 /* pass control back to the list */
 918                 sdb_object_deref(obj);
 919         }
 920         return 0;
 921 } /* sdb_plugin_read_loop */
 922
 923 char *
 924 sdb_plugin_cname(char *hostname)
 925 {
 926         sdb_llist_iter_t *iter;
 927
 928         if (! hostname)
 929                 return NULL;
 930
 931         if (! cname_list)
 932                 return hostname;
 933
 934         iter = sdb_llist_get_iter(cname_list);
 935         while (sdb_llist_iter_has_next(iter)) {
 936                 sdb_plugin_cname_cb callback;
 937                 char *cname;
 938
 939                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 940                 assert(obj);
 941
 942                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 943                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
 944                 if (cname) {
 945                         free(hostname);
 946                         hostname = cname;
 947                 }
 948                 /* else: don't change hostname */
 949         }
 950         sdb_llist_iter_destroy(iter);
 951         return hostname;
 952 } /* sdb_plugin_cname */
 953
 954 int
 955 sdb_plugin_log(int prio, const char *msg)
 956 {
 957         sdb_llist_iter_t *iter;
 958         int ret = -1;
 959
 960         if (! msg)
 961                 return 0;
 962
 963         if (! log_list)
 964                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
 965
 966         iter = sdb_llist_get_iter(log_list);
 967         while (sdb_llist_iter_has_next(iter)) {
 968                 sdb_plugin_log_cb callback;
 969                 int tmp;
 970
 971                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 972                 assert(obj);
 973
 974                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 975                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
 976                 if (tmp > ret)
 977                         ret = tmp;
 978         }
 979         sdb_llist_iter_destroy(iter);
 980         return ret;
 981 } /* sdb_plugin_log */
 982
 983 int
 984 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
 985 {
 986         sdb_strbuf_t *buf;
 987         int ret;
 988
 989         if (! fmt)
 990                 return 0;
 991
 992         buf = sdb_strbuf_create(64);
 993         if (! buf) {
 994                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
 995                 ret += vfprintf(stderr, fmt, ap);
 996                 return ret;
 997         }
 998
 999         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1000                 sdb_strbuf_destroy(buf);
1001                 return -1;
1002         }
1003
1004         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1005         sdb_strbuf_destroy(buf);
1006         return ret;
1007 } /* sdb_plugin_vlogf */
1008
1009 int
1010 sdb_plugin_logf(int prio, const char *fmt, ...)
1011 {
1012         va_list ap;
1013         int ret;
1014
1015         if (! fmt)
1016                 return 0;
1017
1018         va_start(ap, fmt);
1019         ret = sdb_plugin_vlogf(prio, fmt, ap);
1020         va_end(ap);
1021         return ret;
1022 } /* sdb_plugin_logf */
1023
1024 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1025