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         sdb_log(SDB_LOG_INFO, "core: Unloading module %s", plugin_name);
 243         obj = sdb_llist_remove_by_name(all_plugins, plugin_name);
 244         sdb_object_deref(obj);
 245 } /* plugin_unregister_by_name */
 246
 247 /*
 248  * private types
 249  */
 250
 251 static int
 252 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 253 {
 254         ctx_t *ctx = CTX(obj);
 255
 256         assert(ctx);
 257
 258         ctx->public = plugin_default_ctx;
 259         ctx->info = plugin_default_info;
 260         ctx->handle = NULL;
 261         ctx->use_cnt = 1;
 262         return 0;
 263 } /* ctx_init */
 264
 265 static void
 266 ctx_destroy(sdb_object_t *obj)
 267 {
 268         ctx_t *ctx = CTX(obj);
 269
 270         if (ctx->handle) {
 271                 const char *err;
 272                 lt_dlerror();
 273                 lt_dlclose(ctx->handle);
 274                 if ((err = lt_dlerror()))
 275                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload plugin %s: %s",
 276                                         ctx->info.plugin_name, err);
 277         }
 278
 279         plugin_info_clear(&ctx->info);
 280 } /* ctx_destroy */
 281
 282 static sdb_type_t ctx_type = {
 283         sizeof(ctx_t),
 284
 285         ctx_init,
 286         ctx_destroy
 287 };
 288
 289 static ctx_t *
 290 ctx_create(const char *name)
 291 {
 292         ctx_t *ctx;
 293
 294         ctx = CTX(sdb_object_create(name, ctx_type));
 295         if (! ctx)
 296                 return NULL;
 297
 298         if (! plugin_ctx_key_initialized)
 299                 ctx_key_init();
 300         pthread_setspecific(plugin_ctx_key, ctx);
 301         return ctx;
 302 } /* ctx_create */
 303
 304 static ctx_t *
 305 ctx_get(void)
 306 {
 307         if (! plugin_ctx_key_initialized)
 308                 ctx_key_init();
 309         return pthread_getspecific(plugin_ctx_key);
 310 } /* ctx_get */
 311
 312 static ctx_t *
 313 ctx_set(ctx_t *new)
 314 {
 315         ctx_t *old;
 316
 317         if (! plugin_ctx_key_initialized)
 318                 ctx_key_init();
 319
 320         old = pthread_getspecific(plugin_ctx_key);
 321         pthread_setspecific(plugin_ctx_key, new);
 322         return old;
 323 } /* ctx_set */
 324
 325 static int
 326 plugin_cb_init(sdb_object_t *obj, va_list ap)
 327 {
 328         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 329         const char   *type = va_arg(ap, const char *);
 330         void     *callback = va_arg(ap, void *);
 331         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 332
 333         assert(list);
 334         assert(type);
 335         assert(obj);
 336
 337         if (sdb_llist_search_by_name(*list, obj->name)) {
 338                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 339                                 "has already been registered. Ignoring newly "
 340                                 "registered version.", type, obj->name);
 341                 return -1;
 342         }
 343
 344         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 345         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 346         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 347
 348         sdb_object_ref(ud);
 349         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 350         return 0;
 351 } /* plugin_cb_init */
 352
 353 static void
 354 plugin_cb_destroy(sdb_object_t *obj)
 355 {
 356         assert(obj);
 357         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 358         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 359 } /* plugin_cb_destroy */
 360
 361 static sdb_type_t sdb_plugin_cb_type = {
 362         sizeof(sdb_plugin_cb_t),
 363
 364         plugin_cb_init,
 365         plugin_cb_destroy
 366 };
 367
 368 static sdb_type_t sdb_plugin_collector_cb_type = {
 369         sizeof(sdb_plugin_collector_cb_t),
 370
 371         plugin_cb_init,
 372         plugin_cb_destroy
 373 };
 374
 375 static int
 376 plugin_add_callback(sdb_llist_t **list, const char *type,
 377                 const char *name, void *callback, sdb_object_t *user_data)
 378 {
 379         sdb_object_t *obj;
 380
 381         if ((! name) || (! callback))
 382                 return -1;
 383
 384         assert(list);
 385
 386         if (! *list)
 387                 *list = sdb_llist_create();
 388         if (! *list)
 389                 return -1;
 390
 391         obj = sdb_object_create(name, sdb_plugin_cb_type,
 392                         list, type, callback, user_data);
 393         if (! obj)
 394                 return -1;
 395
 396         if (sdb_llist_append(*list, obj)) {
 397                 sdb_object_deref(obj);
 398                 return -1;
 399         }
 400
 401         /* pass control to the list */
 402         sdb_object_deref(obj);
 403
 404         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 405                         type, name);
 406         return 0;
 407 } /* plugin_add_callback */
 408
 409 /*
 410  * public API
 411  */
 412
 413 int
 414 sdb_plugin_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 415 {
 416         char  base_name[name ? strlen(name) + 1 : 1];
 417         const char *name_ptr;
 418         char *tmp;
 419
 420         char filename[1024];
 421         ctx_t *ctx;
 422
 423         lt_dlhandle lh;
 424
 425         int (*mod_init)(sdb_plugin_info_t *);
 426         int status;
 427
 428         if ((! name) || (! *name))
 429                 return -1;
 430
 431         base_name[0] = '\0';
 432         name_ptr = name;
 433
 434         while ((tmp = strstr(name_ptr, "::"))) {
 435                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 436                 strcat(base_name, "/");
 437                 name_ptr = tmp + strlen("::");
 438         }
 439         strcat(base_name, name_ptr);
 440
 441         ctx = CTX(sdb_llist_search_by_name(all_plugins, base_name));
 442         if (ctx) {
 443                 /* plugin already loaded */
 444                 ++ctx->use_cnt;
 445                 return 0;
 446         }
 447
 448         snprintf(filename, sizeof(filename), "%s/%s.so",
 449                         PKGLIBDIR, base_name);
 450         filename[sizeof(filename) - 1] = '\0';
 451
 452         if (access(filename, R_OK)) {
 453                 char errbuf[1024];
 454                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 455                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 456                 return -1;
 457         }
 458
 459         lt_dlinit();
 460         lt_dlerror();
 461
 462         lh = lt_dlopen(filename);
 463         if (! lh) {
 464                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 465                                 "The most common cause for this problem are missing "
 466                                 "dependencies.\n", name, lt_dlerror());
 467                 return -1;
 468         }
 469
 470         if (ctx_get())
 471                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 472
 473         ctx = ctx_create(name);
 474         if (! ctx) {
 475                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 476                 return -1;
 477         }
 478
 479         ctx->info.plugin_name = strdup(name);
 480         ctx->info.filename = strdup(filename);
 481         ctx->handle = lh;
 482
 483         if (plugin_ctx)
 484                 ctx->public = *plugin_ctx;
 485
 486         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 487         if (! mod_init) {
 488                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 489                                 "could not find symbol 'sdb_module_init'", name);
 490                 sdb_object_deref(SDB_OBJ(ctx));
 491                 return -1;
 492         }
 493
 494         status = mod_init(&ctx->info);
 495         if (status) {
 496                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 497                                 "module '%s'", name);
 498                 plugin_unregister_by_name(ctx->info.plugin_name);
 499                 sdb_object_deref(SDB_OBJ(ctx));
 500                 return -1;
 501         }
 502
 503         /* compare minor version */
 504         if ((ctx->info.version < 0)
 505                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 506                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 507                                 "plugin '%s' (%i.%i.%i) does not match our version "
 508                                 "(%i.%i.%i); this might cause problems",
 509                                 name, SDB_VERSION_DECODE(ctx->info.version),
 510                                 SDB_VERSION_DECODE(SDB_VERSION));
 511
 512         if (! all_plugins) {
 513                 if (! (all_plugins = sdb_llist_create())) {
 514                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 515                                         "internal error while creating linked list", name);
 516                         plugin_unregister_by_name(ctx->info.plugin_name);
 517                         sdb_object_deref(SDB_OBJ(ctx));
 518                         return -1;
 519                 }
 520         }
 521
 522         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 523
 524         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 525                         "plugin '%s' v%i (%s)\n\t%s\n\tLicense: %s",
 526                         INFO_GET(&ctx->info, name), ctx->info.plugin_version,
 527                         INFO_GET(&ctx->info, description),
 528                         INFO_GET(&ctx->info, copyright),
 529                         INFO_GET(&ctx->info, license));
 530
 531         /* any registered callbacks took ownership of the context */
 532         sdb_object_deref(SDB_OBJ(ctx));
 533
 534         /* reset */
 535         ctx_set(NULL);
 536         return 0;
 537 } /* sdb_plugin_load */
 538
 539 int
 540 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 541 {
 542         va_list ap;
 543
 544         if (! info)
 545                 return -1;
 546
 547         va_start(ap, type);
 548
 549         switch (type) {
 550                 case SDB_PLUGIN_INFO_NAME:
 551                         {
 552                                 char *name = va_arg(ap, char *);
 553                                 if (name) {
 554                                         if (info->name)
 555                                                 free(info->name);
 556                                         info->name = strdup(name);
 557                                 }
 558                         }
 559                         break;
 560                 case SDB_PLUGIN_INFO_DESC:
 561                         {
 562                                 char *desc = va_arg(ap, char *);
 563                                 if (desc) {
 564                                         if (info->description)
 565                                                 free(info->description);
 566                                         info->description = strdup(desc);
 567                                 }
 568                         }
 569                         break;
 570                 case SDB_PLUGIN_INFO_COPYRIGHT:
 571                         {
 572                                 char *copyright = va_arg(ap, char *);
 573                                 if (copyright)
 574                                         info->copyright = strdup(copyright);
 575                         }
 576                         break;
 577                 case SDB_PLUGIN_INFO_LICENSE:
 578                         {
 579                                 char *license = va_arg(ap, char *);
 580                                 if (license) {
 581                                         if (info->license)
 582                                                 free(info->license);
 583                                         info->license = strdup(license);
 584                                 }
 585                         }
 586                         break;
 587                 case SDB_PLUGIN_INFO_VERSION:
 588                         {
 589                                 int version = va_arg(ap, int);
 590                                 info->version = version;
 591                         }
 592                         break;
 593                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 594                         {
 595                                 int version = va_arg(ap, int);
 596                                 info->plugin_version = version;
 597                         }
 598                         break;
 599                 default:
 600                         va_end(ap);
 601                         return -1;
 602         }
 603
 604         va_end(ap);
 605         return 0;
 606 } /* sdb_plugin_set_info */
 607
 608 int
 609 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
 610 {
 611         return plugin_add_callback(&config_list, "init", name,
 612                         (void *)callback, NULL);
 613 } /* sdb_plugin_register_config */
 614
 615 int
 616 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 617                 sdb_object_t *user_data)
 618 {
 619         return plugin_add_callback(&init_list, "init", name,
 620                         (void *)callback, user_data);
 621 } /* sdb_plugin_register_init */
 622
 623 int
 624 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 625                 sdb_object_t *user_data)
 626 {
 627         return plugin_add_callback(&shutdown_list, "shutdown", name,
 628                         (void *)callback, user_data);
 629 } /* sdb_plugin_register_shutdown */
 630
 631 int
 632 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 633                 sdb_object_t *user_data)
 634 {
 635         return plugin_add_callback(&log_list, "log", name, (void *)callback,
 636                         user_data);
 637 } /* sdb_plugin_register_log */
 638
 639 int
 640 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 641                 sdb_object_t *user_data)
 642 {
 643         return plugin_add_callback(&cname_list, "cname", name, (void *)callback,
 644                         user_data);
 645 } /* sdb_plugin_register_cname */
 646
 647 int
 648 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 649                 const sdb_time_t *interval, sdb_object_t *user_data)
 650 {
 651         sdb_object_t *obj;
 652
 653         if ((! name) || (! callback))
 654                 return -1;
 655
 656         if (! collector_list)
 657                 collector_list = sdb_llist_create();
 658         if (! collector_list)
 659                 return -1;
 660
 661         obj = sdb_object_create(name, sdb_plugin_collector_cb_type,
 662                         &collector_list, "collector", callback, user_data);
 663         if (! obj)
 664                 return -1;
 665
 666         if (interval)
 667                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 668         else {
 669                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 670
 671                 if (tmp > 0)
 672                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 673                 else
 674                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 675         }
 676
 677         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 678                 char errbuf[1024];
 679                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 680                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 681                 sdb_object_deref(obj);
 682                 return -1;
 683         }
 684
 685         if (sdb_llist_insert_sorted(collector_list, obj,
 686                                 plugin_cmp_next_update)) {
 687                 sdb_object_deref(obj);
 688                 return -1;
 689         }
 690
 691         /* pass control to the list */
 692         sdb_object_deref(obj);
 693
 694         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 695                         "(interval = %.3fs).", name,
 696                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 697         return 0;
 698 } /* sdb_plugin_register_collector */
 699
 700 sdb_plugin_ctx_t
 701 sdb_plugin_get_ctx(void)
 702 {
 703         ctx_t *c;
 704
 705         c = ctx_get();
 706         if (! c) {
 707                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 708                                 "context outside a plugin");
 709                 return plugin_default_ctx;
 710         }
 711         return c->public;
 712 } /* sdb_plugin_get_ctx */
 713
 714 int
 715 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 716 {
 717         ctx_t *c;
 718
 719         c = ctx_get();
 720         if (! c) {
 721                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 722                                 "context outside a plugin");
 723                 return -1;
 724         }
 725
 726         if (old)
 727                 *old = c->public;
 728         c->public = ctx;
 729         return 0;
 730 } /* sdb_plugin_set_ctx */
 731
 732 int
 733 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 734 {
 735         sdb_plugin_cb_t *plugin;
 736         sdb_plugin_config_cb callback;
 737
 738         ctx_t *old_ctx;
 739
 740         int status;
 741
 742         if ((! name) || (! ci))
 743                 return -1;
 744
 745         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 746         if (! plugin) {
 747                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 748                 if (! ctx)
 749                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' not loaded.", name);
 750                 else
 751                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 752                                         "a config callback.", name);
 753                 errno = ENOENT;
 754                 return -1;
 755         }
 756
 757         old_ctx = ctx_set(plugin->cb_ctx);
 758         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 759         status = callback(ci);
 760         ctx_set(old_ctx);
 761         return status;
 762 } /* sdb_plugin_configure */
 763
 764 int
 765 sdb_plugin_init_all(void)
 766 {
 767         sdb_llist_iter_t *iter;
 768         int ret = 0;
 769
 770         iter = sdb_llist_get_iter(init_list);
 771         while (sdb_llist_iter_has_next(iter)) {
 772                 sdb_plugin_cb_t *cb;
 773                 sdb_plugin_init_cb callback;
 774                 ctx_t *old_ctx;
 775
 776                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 777                 assert(obj);
 778                 cb = SDB_PLUGIN_CB(obj);
 779
 780                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 781
 782                 old_ctx = ctx_set(cb->cb_ctx);
 783                 if (callback(cb->cb_user_data)) {
 784                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 785                                         "'%s'. Unregistering all callbacks.", obj->name);
 786                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 787                         ++ret;
 788                 }
 789                 ctx_set(old_ctx);
 790         }
 791         sdb_llist_iter_destroy(iter);
 792         return ret;
 793 } /* sdb_plugin_init_all */
 794
 795 int
 796 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 797 {
 798         if (! collector_list) {
 799                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 800                                 "Quiting main loop.");
 801                 return -1;
 802         }
 803
 804         if (! loop)
 805                 return -1;
 806
 807         while (loop->do_loop) {
 808                 sdb_plugin_collector_cb callback;
 809                 ctx_t *old_ctx;
 810
 811                 sdb_time_t interval, now;
 812
 813                 sdb_object_t *obj = sdb_llist_shift(collector_list);
 814                 if (! obj)
 815                         return -1;
 816
 817                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
 818
 819                 if (! (now = sdb_gettime())) {
 820                         char errbuf[1024];
 821                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 822                                         "time in collector main loop: %s",
 823                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 824                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 825                 }
 826
 827                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 828                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
 829
 830                         errno = 0;
 831                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
 832                                 if (errno != EINTR) {
 833                                         char errbuf[1024];
 834                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
 835                                                         "in collector main loop: %s",
 836                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 837                                         return -1;
 838                                 }
 839                                 errno = 0;
 840                         }
 841
 842                         if (! loop->do_loop)
 843                                 return 0;
 844                 }
 845
 846                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
 847                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
 848                         /* XXX */
 849                 }
 850                 ctx_set(old_ctx);
 851
 852                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
 853                 if (! interval)
 854                         interval = loop->default_interval;
 855                 if (! interval) {
 856                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
 857                                         "for plugin '%s'; skipping any further "
 858                                         "iterations.", obj->name);
 859                         sdb_object_deref(obj);
 860                         continue;
 861                 }
 862
 863                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
 864
 865                 if (! (now = sdb_gettime())) {
 866                         char errbuf[1024];
 867                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 868                                         "time in collector main loop: %s",
 869                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 870                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 871                 }
 872
 873                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 874                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
 875                                         "long; skipping iterations to keep up.",
 876                                         obj->name);
 877                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
 878                 }
 879
 880                 if (sdb_llist_insert_sorted(collector_list, obj,
 881                                         plugin_cmp_next_update)) {
 882                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
 883                                         "plugin '%s' into collector list. Unable to further "
 884                                         "use the plugin.",
 885                                         obj->name);
 886                         sdb_object_deref(obj);
 887                         return -1;
 888                 }
 889
 890                 /* pass control back to the list */
 891                 sdb_object_deref(obj);
 892         }
 893         return 0;
 894 } /* sdb_plugin_read_loop */
 895
 896 char *
 897 sdb_plugin_cname(char *hostname)
 898 {
 899         sdb_llist_iter_t *iter;
 900
 901         if (! hostname)
 902                 return NULL;
 903
 904         if (! cname_list)
 905                 return hostname;
 906
 907         iter = sdb_llist_get_iter(cname_list);
 908         while (sdb_llist_iter_has_next(iter)) {
 909                 sdb_plugin_cname_cb callback;
 910                 char *cname;
 911
 912                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 913                 assert(obj);
 914
 915                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 916                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
 917                 if (cname) {
 918                         free(hostname);
 919                         hostname = cname;
 920                 }
 921                 /* else: don't change hostname */
 922         }
 923         sdb_llist_iter_destroy(iter);
 924         return hostname;
 925 } /* sdb_plugin_cname */
 926
 927 int
 928 sdb_plugin_log(int prio, const char *msg)
 929 {
 930         sdb_llist_iter_t *iter;
 931         int ret = -1;
 932
 933         if (! msg)
 934                 return 0;
 935
 936         if (! log_list)
 937                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
 938
 939         iter = sdb_llist_get_iter(log_list);
 940         while (sdb_llist_iter_has_next(iter)) {
 941                 sdb_plugin_log_cb callback;
 942                 int tmp;
 943
 944                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 945                 assert(obj);
 946
 947                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 948                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
 949                 if (tmp > ret)
 950                         ret = tmp;
 951         }
 952         sdb_llist_iter_destroy(iter);
 953         return ret;
 954 } /* sdb_plugin_log */
 955
 956 int
 957 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
 958 {
 959         sdb_strbuf_t *buf;
 960         int ret;
 961
 962         if (! fmt)
 963                 return 0;
 964
 965         buf = sdb_strbuf_create(64);
 966         if (! buf) {
 967                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
 968                 ret += vfprintf(stderr, fmt, ap);
 969                 return ret;
 970         }
 971
 972         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
 973                 sdb_strbuf_destroy(buf);
 974                 return -1;
 975         }
 976
 977         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
 978         sdb_strbuf_destroy(buf);
 979         return ret;
 980 } /* sdb_plugin_vlogf */
 981
 982 int
 983 sdb_plugin_logf(int prio, const char *fmt, ...)
 984 {
 985         va_list ap;
 986         int ret;
 987
 988         if (! fmt)
 989                 return 0;
 990
 991         va_start(ap, fmt);
 992         ret = sdb_plugin_vlogf(prio, fmt, ap);
 993         va_end(ap);
 994         return ret;
 995 } /* sdb_plugin_logf */
 996
 997 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 998