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);
 200
 201         /* when a plugin was registered from outside a plugin (e.g. the core),
 202          * we don't have a plugin context */
 203         if (! cb->cb_ctx)
 204                 return 1;
 205
 206         if (!strcasecmp(cb->cb_ctx->info.plugin_name, name))
 207                 return 0;
 208         return 1;
 209 } /* plugin_lookup_by_name */
 210
 211 static void
 212 plugin_unregister_by_name(const char *plugin_name)
 213 {
 214         sdb_object_t *obj;
 215         size_t i;
 216
 217         struct {
 218                 const char  *type;
 219                 sdb_llist_t *list;
 220         } all_lists[] = {
 221                 { "config",    config_list },
 222                 { "init",      init_list },
 223                 { "collector", collector_list },
 224                 { "cname",     cname_list },
 225                 { "shutdown",  shutdown_list },
 226                 { "log",       log_list },
 227         };
 228
 229         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 230                 const char  *type = all_lists[i].type;
 231                 sdb_llist_t *list = all_lists[i].list;
 232
 233                 while (1) {
 234                         sdb_plugin_cb_t *cb;
 235
 236                         cb = SDB_PLUGIN_CB(sdb_llist_remove(list,
 237                                                 plugin_lookup_by_name, plugin_name));
 238                         if (! cb)
 239                                 break;
 240
 241                         assert(cb->cb_ctx);
 242
 243                         sdb_log(SDB_LOG_INFO, "core: Unregistering "
 244                                         "%s callback '%s' (module %s)", type, cb->super.name,
 245                                         cb->cb_ctx->info.plugin_name);
 246                         sdb_object_deref(SDB_OBJ(cb));
 247                 }
 248         }
 249
 250         obj = sdb_llist_search_by_name(all_plugins, plugin_name);
 251         if (obj->ref_cnt <= 1)
 252                 sdb_llist_remove_by_name(all_plugins, plugin_name);
 253         /* else: other callbacks still reference it */
 254         sdb_object_deref(obj);
 255 } /* plugin_unregister_by_name */
 256
 257 /*
 258  * private types
 259  */
 260
 261 static int
 262 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 263 {
 264         ctx_t *ctx = CTX(obj);
 265
 266         assert(ctx);
 267
 268         ctx->public = plugin_default_ctx;
 269         ctx->info = plugin_default_info;
 270         ctx->handle = NULL;
 271         ctx->use_cnt = 1;
 272         return 0;
 273 } /* ctx_init */
 274
 275 static void
 276 ctx_destroy(sdb_object_t *obj)
 277 {
 278         ctx_t *ctx = CTX(obj);
 279
 280         if (ctx->handle) {
 281                 const char *err;
 282
 283                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s",
 284                                 ctx->info.plugin_name);
 285
 286                 lt_dlerror();
 287                 lt_dlclose(ctx->handle);
 288                 if ((err = lt_dlerror()))
 289                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload module %s: %s",
 290                                         ctx->info.plugin_name, err);
 291         }
 292
 293         plugin_info_clear(&ctx->info);
 294 } /* ctx_destroy */
 295
 296 static sdb_type_t ctx_type = {
 297         sizeof(ctx_t),
 298
 299         ctx_init,
 300         ctx_destroy
 301 };
 302
 303 static ctx_t *
 304 ctx_get(void)
 305 {
 306         if (! plugin_ctx_key_initialized)
 307                 ctx_key_init();
 308         return pthread_getspecific(plugin_ctx_key);
 309 } /* ctx_get */
 310
 311 static ctx_t *
 312 ctx_set(ctx_t *new)
 313 {
 314         ctx_t *old;
 315
 316         if (! plugin_ctx_key_initialized)
 317                 ctx_key_init();
 318
 319         old = pthread_getspecific(plugin_ctx_key);
 320         if (old)
 321                 sdb_object_deref(SDB_OBJ(old));
 322         if (new)
 323                 sdb_object_ref(SDB_OBJ(new));
 324         pthread_setspecific(plugin_ctx_key, new);
 325         return old;
 326 } /* ctx_set */
 327
 328 static ctx_t *
 329 ctx_create(const char *name)
 330 {
 331         ctx_t *ctx;
 332
 333         ctx = CTX(sdb_object_create(name, ctx_type));
 334         if (! ctx)
 335                 return NULL;
 336
 337         if (! plugin_ctx_key_initialized)
 338                 ctx_key_init();
 339         ctx_set(ctx);
 340         return ctx;
 341 } /* ctx_create */
 342
 343 static int
 344 plugin_cb_init(sdb_object_t *obj, va_list ap)
 345 {
 346         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 347         const char   *type = va_arg(ap, const char *);
 348         void     *callback = va_arg(ap, void *);
 349         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 350
 351         assert(list);
 352         assert(type);
 353         assert(obj);
 354
 355         if (sdb_llist_search_by_name(*list, obj->name)) {
 356                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 357                                 "has already been registered. Ignoring newly "
 358                                 "registered version.", type, obj->name);
 359                 return -1;
 360         }
 361
 362         /* cb_ctx may be NULL if the plugin was not registered by a plugin */
 363
 364         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 365         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 366         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 367
 368         sdb_object_ref(ud);
 369         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 370         return 0;
 371 } /* plugin_cb_init */
 372
 373 static void
 374 plugin_cb_destroy(sdb_object_t *obj)
 375 {
 376         assert(obj);
 377         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 378         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 379 } /* plugin_cb_destroy */
 380
 381 static sdb_type_t sdb_plugin_cb_type = {
 382         sizeof(sdb_plugin_cb_t),
 383
 384         plugin_cb_init,
 385         plugin_cb_destroy
 386 };
 387
 388 static sdb_type_t sdb_plugin_collector_cb_type = {
 389         sizeof(sdb_plugin_collector_cb_t),
 390
 391         plugin_cb_init,
 392         plugin_cb_destroy
 393 };
 394
 395 static int
 396 module_init(const char *name, lt_dlhandle lh, sdb_plugin_info_t *info)
 397 {
 398         int (*mod_init)(sdb_plugin_info_t *);
 399         int status;
 400
 401         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 402         if (! mod_init) {
 403                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 404                                 "could not find symbol 'sdb_module_init'", name);
 405                 return -1;
 406         }
 407
 408         status = mod_init(info);
 409         if (status) {
 410                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 411                                 "module '%s'", name);
 412                 plugin_unregister_by_name(name);
 413                 return -1;
 414         }
 415         return 0;
 416 } /* module_init */
 417
 418 static int
 419 module_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 420 {
 421         char  base_name[name ? strlen(name) + 1 : 1];
 422         const char *name_ptr;
 423         char *tmp;
 424
 425         char filename[1024];
 426         lt_dlhandle lh;
 427
 428         ctx_t *ctx;
 429
 430         int status;
 431
 432         base_name[0] = '\0';
 433         name_ptr = name;
 434
 435         while ((tmp = strstr(name_ptr, "::"))) {
 436                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 437                 strcat(base_name, "/");
 438                 name_ptr = tmp + strlen("::");
 439         }
 440         strcat(base_name, name_ptr);
 441
 442         snprintf(filename, sizeof(filename), "%s/%s.so",
 443                         PKGLIBDIR, base_name);
 444         filename[sizeof(filename) - 1] = '\0';
 445
 446         if (access(filename, R_OK)) {
 447                 char errbuf[1024];
 448                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 449                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 450                 return -1;
 451         }
 452
 453         lt_dlinit();
 454         lt_dlerror();
 455
 456         lh = lt_dlopen(filename);
 457         if (! lh) {
 458                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 459                                 "The most common cause for this problem are missing "
 460                                 "dependencies.\n", name, lt_dlerror());
 461                 return -1;
 462         }
 463
 464         if (ctx_get())
 465                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 466
 467         ctx = ctx_create(name);
 468         if (! ctx) {
 469                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 470                 return -1;
 471         }
 472
 473         ctx->info.plugin_name = strdup(name);
 474         ctx->info.filename = strdup(filename);
 475         ctx->handle = lh;
 476
 477         if (plugin_ctx)
 478                 ctx->public = *plugin_ctx;
 479
 480         if ((status = module_init(name, lh, &ctx->info))) {
 481                 sdb_object_deref(SDB_OBJ(ctx));
 482                 return status;
 483         }
 484
 485         /* compare minor version */
 486         if ((ctx->info.version < 0)
 487                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 488                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 489                                 "plugin '%s' (%i.%i.%i) does not match our version "
 490                                 "(%i.%i.%i); this might cause problems",
 491                                 name, SDB_VERSION_DECODE(ctx->info.version),
 492                                 SDB_VERSION_DECODE(SDB_VERSION));
 493
 494         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 495
 496         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 497                         "plugin '%s' v%i (%s)\n\t%s\n\tLicense: %s",
 498                         INFO_GET(&ctx->info, name), ctx->info.plugin_version,
 499                         INFO_GET(&ctx->info, description),
 500                         INFO_GET(&ctx->info, copyright),
 501                         INFO_GET(&ctx->info, license));
 502
 503         /* any registered callbacks took ownership of the context */
 504         sdb_object_deref(SDB_OBJ(ctx));
 505
 506         /* reset */
 507         ctx_set(NULL);
 508         return 0;
 509 } /* module_load */
 510
 511 static int
 512 plugin_add_callback(sdb_llist_t **list, const char *type,
 513                 const char *name, void *callback, sdb_object_t *user_data)
 514 {
 515         sdb_object_t *obj;
 516
 517         if ((! name) || (! callback))
 518                 return -1;
 519
 520         assert(list);
 521
 522         if (! *list)
 523                 *list = sdb_llist_create();
 524         if (! *list)
 525                 return -1;
 526
 527         obj = sdb_object_create(name, sdb_plugin_cb_type,
 528                         list, type, callback, user_data);
 529         if (! obj)
 530                 return -1;
 531
 532         if (sdb_llist_append(*list, obj)) {
 533                 sdb_object_deref(obj);
 534                 return -1;
 535         }
 536
 537         /* pass control to the list */
 538         sdb_object_deref(obj);
 539
 540         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 541                         type, name);
 542         return 0;
 543 } /* plugin_add_callback */
 544
 545 /*
 546  * public API
 547  */
 548
 549 int
 550 sdb_plugin_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 551 {
 552         ctx_t *ctx;
 553
 554         if ((! name) || (! *name))
 555                 return -1;
 556
 557         if (! all_plugins) {
 558                 if (! (all_plugins = sdb_llist_create())) {
 559                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 560                                         "internal error while creating linked list", name);
 561                         return -1;
 562                 }
 563         }
 564
 565         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 566         if (ctx) {
 567                 /* plugin already loaded */
 568                 ++ctx->use_cnt;
 569                 return 0;
 570         }
 571
 572         return module_load(name, plugin_ctx);
 573 } /* sdb_plugin_load */
 574
 575 int
 576 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 577 {
 578         va_list ap;
 579
 580         if (! info)
 581                 return -1;
 582
 583         va_start(ap, type);
 584
 585         switch (type) {
 586                 case SDB_PLUGIN_INFO_NAME:
 587                         {
 588                                 char *name = va_arg(ap, char *);
 589                                 if (name) {
 590                                         if (info->name)
 591                                                 free(info->name);
 592                                         info->name = strdup(name);
 593                                 }
 594                         }
 595                         break;
 596                 case SDB_PLUGIN_INFO_DESC:
 597                         {
 598                                 char *desc = va_arg(ap, char *);
 599                                 if (desc) {
 600                                         if (info->description)
 601                                                 free(info->description);
 602                                         info->description = strdup(desc);
 603                                 }
 604                         }
 605                         break;
 606                 case SDB_PLUGIN_INFO_COPYRIGHT:
 607                         {
 608                                 char *copyright = va_arg(ap, char *);
 609                                 if (copyright)
 610                                         info->copyright = strdup(copyright);
 611                         }
 612                         break;
 613                 case SDB_PLUGIN_INFO_LICENSE:
 614                         {
 615                                 char *license = va_arg(ap, char *);
 616                                 if (license) {
 617                                         if (info->license)
 618                                                 free(info->license);
 619                                         info->license = strdup(license);
 620                                 }
 621                         }
 622                         break;
 623                 case SDB_PLUGIN_INFO_VERSION:
 624                         {
 625                                 int version = va_arg(ap, int);
 626                                 info->version = version;
 627                         }
 628                         break;
 629                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 630                         {
 631                                 int version = va_arg(ap, int);
 632                                 info->plugin_version = version;
 633                         }
 634                         break;
 635                 default:
 636                         va_end(ap);
 637                         return -1;
 638         }
 639
 640         va_end(ap);
 641         return 0;
 642 } /* sdb_plugin_set_info */
 643
 644 int
 645 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
 646 {
 647         return plugin_add_callback(&config_list, "init", name,
 648                         (void *)callback, NULL);
 649 } /* sdb_plugin_register_config */
 650
 651 int
 652 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 653                 sdb_object_t *user_data)
 654 {
 655         return plugin_add_callback(&init_list, "init", name,
 656                         (void *)callback, user_data);
 657 } /* sdb_plugin_register_init */
 658
 659 int
 660 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 661                 sdb_object_t *user_data)
 662 {
 663         return plugin_add_callback(&shutdown_list, "shutdown", name,
 664                         (void *)callback, user_data);
 665 } /* sdb_plugin_register_shutdown */
 666
 667 int
 668 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 669                 sdb_object_t *user_data)
 670 {
 671         return plugin_add_callback(&log_list, "log", name, (void *)callback,
 672                         user_data);
 673 } /* sdb_plugin_register_log */
 674
 675 int
 676 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 677                 sdb_object_t *user_data)
 678 {
 679         return plugin_add_callback(&cname_list, "cname", name, (void *)callback,
 680                         user_data);
 681 } /* sdb_plugin_register_cname */
 682
 683 int
 684 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 685                 const sdb_time_t *interval, sdb_object_t *user_data)
 686 {
 687         sdb_object_t *obj;
 688
 689         if ((! name) || (! callback))
 690                 return -1;
 691
 692         if (! collector_list)
 693                 collector_list = sdb_llist_create();
 694         if (! collector_list)
 695                 return -1;
 696
 697         obj = sdb_object_create(name, sdb_plugin_collector_cb_type,
 698                         &collector_list, "collector", callback, user_data);
 699         if (! obj)
 700                 return -1;
 701
 702         if (interval)
 703                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 704         else {
 705                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 706
 707                 if (tmp > 0)
 708                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 709                 else
 710                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 711         }
 712
 713         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 714                 char errbuf[1024];
 715                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 716                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 717                 sdb_object_deref(obj);
 718                 return -1;
 719         }
 720
 721         if (sdb_llist_insert_sorted(collector_list, obj,
 722                                 plugin_cmp_next_update)) {
 723                 sdb_object_deref(obj);
 724                 return -1;
 725         }
 726
 727         /* pass control to the list */
 728         sdb_object_deref(obj);
 729
 730         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 731                         "(interval = %.3fs).", name,
 732                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 733         return 0;
 734 } /* sdb_plugin_register_collector */
 735
 736 sdb_plugin_ctx_t
 737 sdb_plugin_get_ctx(void)
 738 {
 739         ctx_t *c;
 740
 741         c = ctx_get();
 742         if (! c) {
 743                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 744                                 "context outside a plugin");
 745                 return plugin_default_ctx;
 746         }
 747         return c->public;
 748 } /* sdb_plugin_get_ctx */
 749
 750 int
 751 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 752 {
 753         ctx_t *c;
 754
 755         c = ctx_get();
 756         if (! c) {
 757                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 758                                 "context outside a plugin");
 759                 return -1;
 760         }
 761
 762         if (old)
 763                 *old = c->public;
 764         c->public = ctx;
 765         return 0;
 766 } /* sdb_plugin_set_ctx */
 767
 768 int
 769 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 770 {
 771         sdb_plugin_cb_t *plugin;
 772         sdb_plugin_config_cb callback;
 773
 774         ctx_t *old_ctx;
 775
 776         int status;
 777
 778         if ((! name) || (! ci))
 779                 return -1;
 780
 781         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 782         if (! plugin) {
 783                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 784                 if (! ctx)
 785                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' not loaded.", name);
 786                 else
 787                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 788                                         "a config callback.", name);
 789                 errno = ENOENT;
 790                 return -1;
 791         }
 792
 793         old_ctx = ctx_set(plugin->cb_ctx);
 794         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 795         status = callback(ci);
 796         ctx_set(old_ctx);
 797         return status;
 798 } /* sdb_plugin_configure */
 799
 800 int
 801 sdb_plugin_init_all(void)
 802 {
 803         sdb_llist_iter_t *iter;
 804         int ret = 0;
 805
 806         iter = sdb_llist_get_iter(init_list);
 807         while (sdb_llist_iter_has_next(iter)) {
 808                 sdb_plugin_cb_t *cb;
 809                 sdb_plugin_init_cb callback;
 810                 ctx_t *old_ctx;
 811
 812                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 813                 assert(obj);
 814                 cb = SDB_PLUGIN_CB(obj);
 815
 816                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 817
 818                 old_ctx = ctx_set(cb->cb_ctx);
 819                 if (callback(cb->cb_user_data)) {
 820                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 821                                         "'%s'. Unregistering all callbacks.", obj->name);
 822                         ctx_set(old_ctx);
 823                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 824                         ++ret;
 825                 }
 826                 else
 827                         ctx_set(old_ctx);
 828         }
 829         sdb_llist_iter_destroy(iter);
 830         return ret;
 831 } /* sdb_plugin_init_all */
 832
 833 int
 834 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 835 {
 836         if (! collector_list) {
 837                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 838                                 "Quiting main loop.");
 839                 return -1;
 840         }
 841
 842         if (! loop)
 843                 return -1;
 844
 845         while (loop->do_loop) {
 846                 sdb_plugin_collector_cb callback;
 847                 ctx_t *old_ctx;
 848
 849                 sdb_time_t interval, now;
 850
 851                 sdb_object_t *obj = sdb_llist_shift(collector_list);
 852                 if (! obj)
 853                         return -1;
 854
 855                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
 856
 857                 if (! (now = sdb_gettime())) {
 858                         char errbuf[1024];
 859                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 860                                         "time in collector main loop: %s",
 861                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 862                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 863                 }
 864
 865                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 866                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
 867
 868                         errno = 0;
 869                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
 870                                 if (errno != EINTR) {
 871                                         char errbuf[1024];
 872                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
 873                                                         "in collector main loop: %s",
 874                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 875                                         return -1;
 876                                 }
 877                                 errno = 0;
 878                         }
 879
 880                         if (! loop->do_loop)
 881                                 return 0;
 882                 }
 883
 884                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
 885                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
 886                         /* XXX */
 887                 }
 888                 ctx_set(old_ctx);
 889
 890                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
 891                 if (! interval)
 892                         interval = loop->default_interval;
 893                 if (! interval) {
 894                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
 895                                         "for plugin '%s'; skipping any further "
 896                                         "iterations.", obj->name);
 897                         sdb_object_deref(obj);
 898                         continue;
 899                 }
 900
 901                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
 902
 903                 if (! (now = sdb_gettime())) {
 904                         char errbuf[1024];
 905                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 906                                         "time in collector main loop: %s",
 907                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 908                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 909                 }
 910
 911                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 912                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
 913                                         "long; skipping iterations to keep up.",
 914                                         obj->name);
 915                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
 916                 }
 917
 918                 if (sdb_llist_insert_sorted(collector_list, obj,
 919                                         plugin_cmp_next_update)) {
 920                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
 921                                         "plugin '%s' into collector list. Unable to further "
 922                                         "use the plugin.",
 923                                         obj->name);
 924                         sdb_object_deref(obj);
 925                         return -1;
 926                 }
 927
 928                 /* pass control back to the list */
 929                 sdb_object_deref(obj);
 930         }
 931         return 0;
 932 } /* sdb_plugin_read_loop */
 933
 934 char *
 935 sdb_plugin_cname(char *hostname)
 936 {
 937         sdb_llist_iter_t *iter;
 938
 939         if (! hostname)
 940                 return NULL;
 941
 942         if (! cname_list)
 943                 return hostname;
 944
 945         iter = sdb_llist_get_iter(cname_list);
 946         while (sdb_llist_iter_has_next(iter)) {
 947                 sdb_plugin_cname_cb callback;
 948                 char *cname;
 949
 950                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 951                 assert(obj);
 952
 953                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 954                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
 955                 if (cname) {
 956                         free(hostname);
 957                         hostname = cname;
 958                 }
 959                 /* else: don't change hostname */
 960         }
 961         sdb_llist_iter_destroy(iter);
 962         return hostname;
 963 } /* sdb_plugin_cname */
 964
 965 int
 966 sdb_plugin_log(int prio, const char *msg)
 967 {
 968         sdb_llist_iter_t *iter;
 969         int ret = -1;
 970
 971         if (! msg)
 972                 return 0;
 973
 974         if (! sdb_llist_len(log_list))
 975                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
 976
 977         iter = sdb_llist_get_iter(log_list);
 978         while (sdb_llist_iter_has_next(iter)) {
 979                 sdb_plugin_log_cb callback;
 980                 int tmp;
 981
 982                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 983                 assert(obj);
 984
 985                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 986                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
 987                 if (tmp > ret)
 988                         ret = tmp;
 989         }
 990         sdb_llist_iter_destroy(iter);
 991         return ret;
 992 } /* sdb_plugin_log */
 993
 994 int
 995 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
 996 {
 997         sdb_strbuf_t *buf;
 998         int ret;
 999
1000         if (! fmt)
1001                 return 0;
1002
1003         buf = sdb_strbuf_create(64);
1004         if (! buf) {
1005                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
1006                 ret += vfprintf(stderr, fmt, ap);
1007                 return ret;
1008         }
1009
1010         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1011                 sdb_strbuf_destroy(buf);
1012                 return -1;
1013         }
1014
1015         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1016         sdb_strbuf_destroy(buf);
1017         return ret;
1018 } /* sdb_plugin_vlogf */
1019
1020 int
1021 sdb_plugin_logf(int prio, const char *fmt, ...)
1022 {
1023         va_list ap;
1024         int ret;
1025
1026         if (! fmt)
1027                 return 0;
1028
1029         va_start(ap, fmt);
1030         ret = sdb_plugin_vlogf(prio, fmt, ap);
1031         va_end(ap);
1032         return ret;
1033 } /* sdb_plugin_logf */
1034
1035 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1036