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_remove_by_name(all_plugins, plugin_name);
 243         if (obj->ref_cnt <= 1)
 244                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s", 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                 lt_dlerror();
 275                 lt_dlclose(ctx->handle);
 276                 if ((err = lt_dlerror()))
 277                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload plugin %s: %s",
 278                                         ctx->info.plugin_name, err);
 279         }
 280
 281         plugin_info_clear(&ctx->info);
 282 } /* ctx_destroy */
 283
 284 static sdb_type_t ctx_type = {
 285         sizeof(ctx_t),
 286
 287         ctx_init,
 288         ctx_destroy
 289 };
 290
 291 static ctx_t *
 292 ctx_create(const char *name)
 293 {
 294         ctx_t *ctx;
 295
 296         ctx = CTX(sdb_object_create(name, ctx_type));
 297         if (! ctx)
 298                 return NULL;
 299
 300         if (! plugin_ctx_key_initialized)
 301                 ctx_key_init();
 302         sdb_object_ref(SDB_OBJ(ctx));
 303         pthread_setspecific(plugin_ctx_key, ctx);
 304         return ctx;
 305 } /* ctx_create */
 306
 307 static ctx_t *
 308 ctx_get(void)
 309 {
 310         if (! plugin_ctx_key_initialized)
 311                 ctx_key_init();
 312         return pthread_getspecific(plugin_ctx_key);
 313 } /* ctx_get */
 314
 315 static ctx_t *
 316 ctx_set(ctx_t *new)
 317 {
 318         ctx_t *old;
 319
 320         if (! plugin_ctx_key_initialized)
 321                 ctx_key_init();
 322
 323         old = pthread_getspecific(plugin_ctx_key);
 324         if (old)
 325                 sdb_object_deref(SDB_OBJ(old));
 326         if (new)
 327                 sdb_object_ref(SDB_OBJ(new));
 328         pthread_setspecific(plugin_ctx_key, new);
 329         return old;
 330 } /* ctx_set */
 331
 332 static int
 333 plugin_cb_init(sdb_object_t *obj, va_list ap)
 334 {
 335         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 336         const char   *type = va_arg(ap, const char *);
 337         void     *callback = va_arg(ap, void *);
 338         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 339
 340         assert(list);
 341         assert(type);
 342         assert(obj);
 343
 344         if (sdb_llist_search_by_name(*list, obj->name)) {
 345                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 346                                 "has already been registered. Ignoring newly "
 347                                 "registered version.", type, obj->name);
 348                 return -1;
 349         }
 350
 351         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 352         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 353         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 354
 355         sdb_object_ref(ud);
 356         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 357         return 0;
 358 } /* plugin_cb_init */
 359
 360 static void
 361 plugin_cb_destroy(sdb_object_t *obj)
 362 {
 363         assert(obj);
 364         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 365         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 366 } /* plugin_cb_destroy */
 367
 368 static sdb_type_t sdb_plugin_cb_type = {
 369         sizeof(sdb_plugin_cb_t),
 370
 371         plugin_cb_init,
 372         plugin_cb_destroy
 373 };
 374
 375 static sdb_type_t sdb_plugin_collector_cb_type = {
 376         sizeof(sdb_plugin_collector_cb_t),
 377
 378         plugin_cb_init,
 379         plugin_cb_destroy
 380 };
 381
 382 static int
 383 plugin_add_callback(sdb_llist_t **list, const char *type,
 384                 const char *name, void *callback, sdb_object_t *user_data)
 385 {
 386         sdb_object_t *obj;
 387
 388         if ((! name) || (! callback))
 389                 return -1;
 390
 391         assert(list);
 392
 393         if (! *list)
 394                 *list = sdb_llist_create();
 395         if (! *list)
 396                 return -1;
 397
 398         obj = sdb_object_create(name, sdb_plugin_cb_type,
 399                         list, type, callback, user_data);
 400         if (! obj)
 401                 return -1;
 402
 403         if (sdb_llist_append(*list, obj)) {
 404                 sdb_object_deref(obj);
 405                 return -1;
 406         }
 407
 408         /* pass control to the list */
 409         sdb_object_deref(obj);
 410
 411         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 412                         type, name);
 413         return 0;
 414 } /* plugin_add_callback */
 415
 416 /*
 417  * public API
 418  */
 419
 420 int
 421 sdb_plugin_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 422 {
 423         char  base_name[name ? strlen(name) + 1 : 1];
 424         const char *name_ptr;
 425         char *tmp;
 426
 427         char filename[1024];
 428         ctx_t *ctx;
 429
 430         lt_dlhandle lh;
 431
 432         int (*mod_init)(sdb_plugin_info_t *);
 433         int status;
 434
 435         if ((! name) || (! *name))
 436                 return -1;
 437
 438         base_name[0] = '\0';
 439         name_ptr = name;
 440
 441         while ((tmp = strstr(name_ptr, "::"))) {
 442                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 443                 strcat(base_name, "/");
 444                 name_ptr = tmp + strlen("::");
 445         }
 446         strcat(base_name, name_ptr);
 447
 448         ctx = CTX(sdb_llist_search_by_name(all_plugins, base_name));
 449         if (ctx) {
 450                 /* plugin already loaded */
 451                 ++ctx->use_cnt;
 452                 return 0;
 453         }
 454
 455         snprintf(filename, sizeof(filename), "%s/%s.so",
 456                         PKGLIBDIR, base_name);
 457         filename[sizeof(filename) - 1] = '\0';
 458
 459         if (access(filename, R_OK)) {
 460                 char errbuf[1024];
 461                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 462                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 463                 return -1;
 464         }
 465
 466         lt_dlinit();
 467         lt_dlerror();
 468
 469         lh = lt_dlopen(filename);
 470         if (! lh) {
 471                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 472                                 "The most common cause for this problem are missing "
 473                                 "dependencies.\n", name, lt_dlerror());
 474                 return -1;
 475         }
 476
 477         if (ctx_get())
 478                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 479
 480         ctx = ctx_create(name);
 481         if (! ctx) {
 482                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 483                 return -1;
 484         }
 485
 486         ctx->info.plugin_name = strdup(name);
 487         ctx->info.filename = strdup(filename);
 488         ctx->handle = lh;
 489
 490         if (plugin_ctx)
 491                 ctx->public = *plugin_ctx;
 492
 493         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 494         if (! mod_init) {
 495                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 496                                 "could not find symbol 'sdb_module_init'", name);
 497                 sdb_object_deref(SDB_OBJ(ctx));
 498                 return -1;
 499         }
 500
 501         status = mod_init(&ctx->info);
 502         if (status) {
 503                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 504                                 "module '%s'", name);
 505                 plugin_unregister_by_name(ctx->info.plugin_name);
 506                 sdb_object_deref(SDB_OBJ(ctx));
 507                 return -1;
 508         }
 509
 510         /* compare minor version */
 511         if ((ctx->info.version < 0)
 512                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 513                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 514                                 "plugin '%s' (%i.%i.%i) does not match our version "
 515                                 "(%i.%i.%i); this might cause problems",
 516                                 name, SDB_VERSION_DECODE(ctx->info.version),
 517                                 SDB_VERSION_DECODE(SDB_VERSION));
 518
 519         if (! all_plugins) {
 520                 if (! (all_plugins = sdb_llist_create())) {
 521                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 522                                         "internal error while creating linked list", name);
 523                         plugin_unregister_by_name(ctx->info.plugin_name);
 524                         sdb_object_deref(SDB_OBJ(ctx));
 525                         return -1;
 526                 }
 527         }
 528
 529         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 530
 531         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 532                         "plugin '%s' v%i (%s)\n\t%s\n\tLicense: %s",
 533                         INFO_GET(&ctx->info, name), ctx->info.plugin_version,
 534                         INFO_GET(&ctx->info, description),
 535                         INFO_GET(&ctx->info, copyright),
 536                         INFO_GET(&ctx->info, license));
 537
 538         /* any registered callbacks took ownership of the context */
 539         sdb_object_deref(SDB_OBJ(ctx));
 540
 541         /* reset */
 542         ctx_set(NULL);
 543         return 0;
 544 } /* sdb_plugin_load */
 545
 546 int
 547 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 548 {
 549         va_list ap;
 550
 551         if (! info)
 552                 return -1;
 553
 554         va_start(ap, type);
 555
 556         switch (type) {
 557                 case SDB_PLUGIN_INFO_NAME:
 558                         {
 559                                 char *name = va_arg(ap, char *);
 560                                 if (name) {
 561                                         if (info->name)
 562                                                 free(info->name);
 563                                         info->name = strdup(name);
 564                                 }
 565                         }
 566                         break;
 567                 case SDB_PLUGIN_INFO_DESC:
 568                         {
 569                                 char *desc = va_arg(ap, char *);
 570                                 if (desc) {
 571                                         if (info->description)
 572                                                 free(info->description);
 573                                         info->description = strdup(desc);
 574                                 }
 575                         }
 576                         break;
 577                 case SDB_PLUGIN_INFO_COPYRIGHT:
 578                         {
 579                                 char *copyright = va_arg(ap, char *);
 580                                 if (copyright)
 581                                         info->copyright = strdup(copyright);
 582                         }
 583                         break;
 584                 case SDB_PLUGIN_INFO_LICENSE:
 585                         {
 586                                 char *license = va_arg(ap, char *);
 587                                 if (license) {
 588                                         if (info->license)
 589                                                 free(info->license);
 590                                         info->license = strdup(license);
 591                                 }
 592                         }
 593                         break;
 594                 case SDB_PLUGIN_INFO_VERSION:
 595                         {
 596                                 int version = va_arg(ap, int);
 597                                 info->version = version;
 598                         }
 599                         break;
 600                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 601                         {
 602                                 int version = va_arg(ap, int);
 603                                 info->plugin_version = version;
 604                         }
 605                         break;
 606                 default:
 607                         va_end(ap);
 608                         return -1;
 609         }
 610
 611         va_end(ap);
 612         return 0;
 613 } /* sdb_plugin_set_info */
 614
 615 int
 616 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
 617 {
 618         return plugin_add_callback(&config_list, "init", name,
 619                         (void *)callback, NULL);
 620 } /* sdb_plugin_register_config */
 621
 622 int
 623 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 624                 sdb_object_t *user_data)
 625 {
 626         return plugin_add_callback(&init_list, "init", name,
 627                         (void *)callback, user_data);
 628 } /* sdb_plugin_register_init */
 629
 630 int
 631 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 632                 sdb_object_t *user_data)
 633 {
 634         return plugin_add_callback(&shutdown_list, "shutdown", name,
 635                         (void *)callback, user_data);
 636 } /* sdb_plugin_register_shutdown */
 637
 638 int
 639 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 640                 sdb_object_t *user_data)
 641 {
 642         return plugin_add_callback(&log_list, "log", name, (void *)callback,
 643                         user_data);
 644 } /* sdb_plugin_register_log */
 645
 646 int
 647 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 648                 sdb_object_t *user_data)
 649 {
 650         return plugin_add_callback(&cname_list, "cname", name, (void *)callback,
 651                         user_data);
 652 } /* sdb_plugin_register_cname */
 653
 654 int
 655 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 656                 const sdb_time_t *interval, sdb_object_t *user_data)
 657 {
 658         sdb_object_t *obj;
 659
 660         if ((! name) || (! callback))
 661                 return -1;
 662
 663         if (! collector_list)
 664                 collector_list = sdb_llist_create();
 665         if (! collector_list)
 666                 return -1;
 667
 668         obj = sdb_object_create(name, sdb_plugin_collector_cb_type,
 669                         &collector_list, "collector", callback, user_data);
 670         if (! obj)
 671                 return -1;
 672
 673         if (interval)
 674                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 675         else {
 676                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 677
 678                 if (tmp > 0)
 679                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 680                 else
 681                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 682         }
 683
 684         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 685                 char errbuf[1024];
 686                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 687                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 688                 sdb_object_deref(obj);
 689                 return -1;
 690         }
 691
 692         if (sdb_llist_insert_sorted(collector_list, obj,
 693                                 plugin_cmp_next_update)) {
 694                 sdb_object_deref(obj);
 695                 return -1;
 696         }
 697
 698         /* pass control to the list */
 699         sdb_object_deref(obj);
 700
 701         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 702                         "(interval = %.3fs).", name,
 703                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 704         return 0;
 705 } /* sdb_plugin_register_collector */
 706
 707 sdb_plugin_ctx_t
 708 sdb_plugin_get_ctx(void)
 709 {
 710         ctx_t *c;
 711
 712         c = ctx_get();
 713         if (! c) {
 714                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 715                                 "context outside a plugin");
 716                 return plugin_default_ctx;
 717         }
 718         return c->public;
 719 } /* sdb_plugin_get_ctx */
 720
 721 int
 722 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 723 {
 724         ctx_t *c;
 725
 726         c = ctx_get();
 727         if (! c) {
 728                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 729                                 "context outside a plugin");
 730                 return -1;
 731         }
 732
 733         if (old)
 734                 *old = c->public;
 735         c->public = ctx;
 736         return 0;
 737 } /* sdb_plugin_set_ctx */
 738
 739 int
 740 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 741 {
 742         sdb_plugin_cb_t *plugin;
 743         sdb_plugin_config_cb callback;
 744
 745         ctx_t *old_ctx;
 746
 747         int status;
 748
 749         if ((! name) || (! ci))
 750                 return -1;
 751
 752         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 753         if (! plugin) {
 754                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 755                 if (! ctx)
 756                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' not loaded.", name);
 757                 else
 758                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 759                                         "a config callback.", name);
 760                 errno = ENOENT;
 761                 return -1;
 762         }
 763
 764         old_ctx = ctx_set(plugin->cb_ctx);
 765         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 766         status = callback(ci);
 767         ctx_set(old_ctx);
 768         return status;
 769 } /* sdb_plugin_configure */
 770
 771 int
 772 sdb_plugin_init_all(void)
 773 {
 774         sdb_llist_iter_t *iter;
 775         int ret = 0;
 776
 777         iter = sdb_llist_get_iter(init_list);
 778         while (sdb_llist_iter_has_next(iter)) {
 779                 sdb_plugin_cb_t *cb;
 780                 sdb_plugin_init_cb callback;
 781                 ctx_t *old_ctx;
 782
 783                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 784                 assert(obj);
 785                 cb = SDB_PLUGIN_CB(obj);
 786
 787                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 788
 789                 old_ctx = ctx_set(cb->cb_ctx);
 790                 if (callback(cb->cb_user_data)) {
 791                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 792                                         "'%s'. Unregistering all callbacks.", obj->name);
 793                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 794                         ++ret;
 795                 }
 796                 ctx_set(old_ctx);
 797         }
 798         sdb_llist_iter_destroy(iter);
 799         return ret;
 800 } /* sdb_plugin_init_all */
 801
 802 int
 803 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 804 {
 805         if (! collector_list) {
 806                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 807                                 "Quiting main loop.");
 808                 return -1;
 809         }
 810
 811         if (! loop)
 812                 return -1;
 813
 814         while (loop->do_loop) {
 815                 sdb_plugin_collector_cb callback;
 816                 ctx_t *old_ctx;
 817
 818                 sdb_time_t interval, now;
 819
 820                 sdb_object_t *obj = sdb_llist_shift(collector_list);
 821                 if (! obj)
 822                         return -1;
 823
 824                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
 825
 826                 if (! (now = sdb_gettime())) {
 827                         char errbuf[1024];
 828                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 829                                         "time in collector main loop: %s",
 830                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 831                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 832                 }
 833
 834                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 835                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
 836
 837                         errno = 0;
 838                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
 839                                 if (errno != EINTR) {
 840                                         char errbuf[1024];
 841                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
 842                                                         "in collector main loop: %s",
 843                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 844                                         return -1;
 845                                 }
 846                                 errno = 0;
 847                         }
 848
 849                         if (! loop->do_loop)
 850                                 return 0;
 851                 }
 852
 853                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
 854                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
 855                         /* XXX */
 856                 }
 857                 ctx_set(old_ctx);
 858
 859                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
 860                 if (! interval)
 861                         interval = loop->default_interval;
 862                 if (! interval) {
 863                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
 864                                         "for plugin '%s'; skipping any further "
 865                                         "iterations.", obj->name);
 866                         sdb_object_deref(obj);
 867                         continue;
 868                 }
 869
 870                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
 871
 872                 if (! (now = sdb_gettime())) {
 873                         char errbuf[1024];
 874                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 875                                         "time in collector main loop: %s",
 876                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 877                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 878                 }
 879
 880                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 881                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
 882                                         "long; skipping iterations to keep up.",
 883                                         obj->name);
 884                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
 885                 }
 886
 887                 if (sdb_llist_insert_sorted(collector_list, obj,
 888                                         plugin_cmp_next_update)) {
 889                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
 890                                         "plugin '%s' into collector list. Unable to further "
 891                                         "use the plugin.",
 892                                         obj->name);
 893                         sdb_object_deref(obj);
 894                         return -1;
 895                 }
 896
 897                 /* pass control back to the list */
 898                 sdb_object_deref(obj);
 899         }
 900         return 0;
 901 } /* sdb_plugin_read_loop */
 902
 903 char *
 904 sdb_plugin_cname(char *hostname)
 905 {
 906         sdb_llist_iter_t *iter;
 907
 908         if (! hostname)
 909                 return NULL;
 910
 911         if (! cname_list)
 912                 return hostname;
 913
 914         iter = sdb_llist_get_iter(cname_list);
 915         while (sdb_llist_iter_has_next(iter)) {
 916                 sdb_plugin_cname_cb callback;
 917                 char *cname;
 918
 919                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 920                 assert(obj);
 921
 922                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 923                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
 924                 if (cname) {
 925                         free(hostname);
 926                         hostname = cname;
 927                 }
 928                 /* else: don't change hostname */
 929         }
 930         sdb_llist_iter_destroy(iter);
 931         return hostname;
 932 } /* sdb_plugin_cname */
 933
 934 int
 935 sdb_plugin_log(int prio, const char *msg)
 936 {
 937         sdb_llist_iter_t *iter;
 938         int ret = -1;
 939
 940         if (! msg)
 941                 return 0;
 942
 943         if (! log_list)
 944                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
 945
 946         iter = sdb_llist_get_iter(log_list);
 947         while (sdb_llist_iter_has_next(iter)) {
 948                 sdb_plugin_log_cb callback;
 949                 int tmp;
 950
 951                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 952                 assert(obj);
 953
 954                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 955                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
 956                 if (tmp > ret)
 957                         ret = tmp;
 958         }
 959         sdb_llist_iter_destroy(iter);
 960         return ret;
 961 } /* sdb_plugin_log */
 962
 963 int
 964 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
 965 {
 966         sdb_strbuf_t *buf;
 967         int ret;
 968
 969         if (! fmt)
 970                 return 0;
 971
 972         buf = sdb_strbuf_create(64);
 973         if (! buf) {
 974                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
 975                 ret += vfprintf(stderr, fmt, ap);
 976                 return ret;
 977         }
 978
 979         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
 980                 sdb_strbuf_destroy(buf);
 981                 return -1;
 982         }
 983
 984         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
 985         sdb_strbuf_destroy(buf);
 986         return ret;
 987 } /* sdb_plugin_vlogf */
 988
 989 int
 990 sdb_plugin_logf(int prio, const char *fmt, ...)
 991 {
 992         va_list ap;
 993         int ret;
 994
 995         if (! fmt)
 996                 return 0;
 997
 998         va_start(ap, fmt);
 999         ret = sdb_plugin_vlogf(prio, fmt, ap);
1000         va_end(ap);
1001         return ret;
1002 } /* sdb_plugin_logf */
1003
1004 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1005