src/core/plugin.c

   1 /*
   2  * SysDB - src/core/plugin.c
   3  * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "sysdb.h"
  33 #include "core/plugin.h"
  34 #include "core/time.h"
  35 #include "utils/error.h"
  36 #include "utils/llist.h"
  37 #include "utils/strbuf.h"
  38
  39 #include <assert.h>
  40
  41 #include <errno.h>
  42
  43 #include <stdarg.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <strings.h>
  47 #include <unistd.h>
  48
  49 #include <ltdl.h>
  50
  51 #include <pthread.h>
  52
  53 /*
  54  * private data types
  55  */
  56
  57 struct sdb_plugin_info {
  58         char *plugin_name;
  59         char *filename;
  60
  61         /* public attributes */
  62         char *name;
  63
  64         char *description;
  65         char *copyright;
  66         char *license;
  67
  68         int   version;
  69         int   plugin_version;
  70 };
  71 #define SDB_PLUGIN_INFO_INIT { \
  72         /* plugin_name */ NULL, /* filename */ NULL, \
  73         /* name */ NULL, /* desc */ NULL, \
  74         /* copyright */ NULL, /* license */ NULL, \
  75         /* version */ -1, /* plugin_version */ -1 }
  76 #define INFO_GET(i, attr) \
  77         ((i)->attr ? (i)->attr : #attr" not set")
  78
  79 typedef struct {
  80         sdb_object_t super;
  81         sdb_plugin_ctx_t public;
  82
  83         sdb_plugin_info_t info;
  84         lt_dlhandle handle;
  85
  86         /* The usage count differs from the object's ref count
  87          * in that it provides higher level information about how
  88          * the plugin is in use. */
  89         size_t use_cnt;
  90 } ctx_t;
  91 #define CTX_INIT { SDB_OBJECT_INIT, \
  92         SDB_PLUGIN_CTX_INIT, SDB_PLUGIN_INFO_INIT, NULL, 0 }
  93
  94 #define CTX(obj) ((ctx_t *)(obj))
  95
  96 typedef struct {
  97         sdb_object_t super;
  98         void *cb_callback;
  99         sdb_object_t *cb_user_data;
 100         ctx_t *cb_ctx;
 101 } sdb_plugin_cb_t;
 102 #define SDB_PLUGIN_CB_INIT { SDB_OBJECT_INIT, \
 103         /* callback = */ NULL, /* user_data = */ NULL, \
 104         SDB_PLUGIN_CTX_INIT }
 105
 106 typedef struct {
 107         sdb_plugin_cb_t super;
 108 #define ccb_callback super.cb_callback
 109 #define ccb_user_data super.cb_user_data
 110 #define ccb_ctx super.cb_ctx
 111         sdb_time_t ccb_interval;
 112         sdb_time_t ccb_next_update;
 113 } sdb_plugin_collector_cb_t;
 114
 115 #define SDB_PLUGIN_CB(obj) ((sdb_plugin_cb_t *)(obj))
 116 #define SDB_CONST_PLUGIN_CB(obj) ((const sdb_plugin_cb_t *)(obj))
 117 #define SDB_PLUGIN_CCB(obj) ((sdb_plugin_collector_cb_t *)(obj))
 118 #define SDB_CONST_PLUGIN_CCB(obj) ((const sdb_plugin_collector_cb_t *)(obj))
 119
 120 /*
 121  * private variables
 122  */
 123
 124 static sdb_plugin_ctx_t  plugin_default_ctx  = SDB_PLUGIN_CTX_INIT;
 125 static sdb_plugin_info_t plugin_default_info = SDB_PLUGIN_INFO_INIT;
 126
 127 static pthread_key_t     plugin_ctx_key;
 128 static _Bool             plugin_ctx_key_initialized = 0;
 129
 130 /* a list of the plugin contexts of all registered plugins */
 131 static sdb_llist_t      *all_plugins = NULL;
 132
 133 static sdb_llist_t      *config_list = NULL;
 134 static sdb_llist_t      *init_list = NULL;
 135 static sdb_llist_t      *collector_list = NULL;
 136 static sdb_llist_t      *cname_list = NULL;
 137 static sdb_llist_t      *shutdown_list = NULL;
 138 static sdb_llist_t      *log_list = NULL;
 139
 140 /*
 141  * private helper functions
 142  */
 143
 144 static void
 145 plugin_info_clear(sdb_plugin_info_t *info)
 146 {
 147         sdb_plugin_info_t empty_info = SDB_PLUGIN_INFO_INIT;
 148         if (! info)
 149                 return;
 150
 151         if (info->plugin_name)
 152                 free(info->plugin_name);
 153         if (info->filename)
 154                 free(info->filename);
 155
 156         if (info->name)
 157                 free(info->name);
 158         if (info->description)
 159                 free(info->description);
 160         if (info->copyright)
 161                 free(info->copyright);
 162         if (info->license)
 163                 free(info->license);
 164
 165         *info = empty_info;
 166 } /* plugin_info_clear */
 167
 168 static void
 169 ctx_key_init(void)
 170 {
 171         if (plugin_ctx_key_initialized)
 172                 return;
 173
 174         pthread_key_create(&plugin_ctx_key, /* destructor */ NULL);
 175         plugin_ctx_key_initialized = 1;
 176 } /* ctx_key_init */
 177
 178 static int
 179 plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
 180 {
 181         const sdb_plugin_collector_cb_t *ccb1
 182                 = (const sdb_plugin_collector_cb_t *)a;
 183         const sdb_plugin_collector_cb_t *ccb2
 184                 = (const sdb_plugin_collector_cb_t *)b;
 185
 186         assert(ccb1 && ccb2);
 187
 188         return (ccb1->ccb_next_update > ccb2->ccb_next_update)
 189                 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
 190                 ? -1 : 0;
 191 } /* plugin_cmp_next_update */
 192
 193 static int
 194 plugin_lookup_by_name(const sdb_object_t *obj, const void *id)
 195 {
 196         const sdb_plugin_cb_t *cb = SDB_CONST_PLUGIN_CB(obj);
 197         const char *name = id;
 198
 199         assert(cb && id && cb->cb_ctx);
 200         if (!strcasecmp(cb->cb_ctx->info.plugin_name, name))
 201                 return 0;
 202         return 1;
 203 } /* plugin_lookup_by_name */
 204
 205 static void
 206 plugin_unregister_by_name(const char *plugin_name)
 207 {
 208         sdb_object_t *obj;
 209         size_t i;
 210
 211         struct {
 212                 const char  *type;
 213                 sdb_llist_t *list;
 214         } all_lists[] = {
 215                 { "config",    config_list },
 216                 { "init",      init_list },
 217                 { "collector", collector_list },
 218                 { "cname",     cname_list },
 219                 { "shutdown",  shutdown_list },
 220                 { "log",       log_list },
 221         };
 222
 223         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 224                 const char  *type = all_lists[i].type;
 225                 sdb_llist_t *list = all_lists[i].list;
 226
 227                 while (1) {
 228                         sdb_plugin_cb_t *cb;
 229
 230                         cb = SDB_PLUGIN_CB(sdb_llist_remove(list,
 231                                                 plugin_lookup_by_name, plugin_name));
 232                         if (! cb)
 233                                 break;
 234
 235                         sdb_log(SDB_LOG_INFO, "core: Unregistering "
 236                                         "%s callback '%s' (module %s)", type, cb->super.name,
 237                                         cb->cb_ctx->info.plugin_name);
 238                         sdb_object_deref(SDB_OBJ(cb));
 239                 }
 240         }
 241
 242         obj = sdb_llist_search_by_name(all_plugins, plugin_name);
 243         if (obj->ref_cnt <= 1)
 244                 sdb_llist_remove_by_name(all_plugins, plugin_name);
 245         /* else: other callbacks still reference it */
 246         sdb_object_deref(obj);
 247 } /* plugin_unregister_by_name */
 248
 249 /*
 250  * private types
 251  */
 252
 253 static int
 254 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 255 {
 256         ctx_t *ctx = CTX(obj);
 257
 258         assert(ctx);
 259
 260         ctx->public = plugin_default_ctx;
 261         ctx->info = plugin_default_info;
 262         ctx->handle = NULL;
 263         ctx->use_cnt = 1;
 264         return 0;
 265 } /* ctx_init */
 266
 267 static void
 268 ctx_destroy(sdb_object_t *obj)
 269 {
 270         ctx_t *ctx = CTX(obj);
 271
 272         if (ctx->handle) {
 273                 const char *err;
 274
 275                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s",
 276                                 ctx->info.plugin_name);
 277
 278                 lt_dlerror();
 279                 lt_dlclose(ctx->handle);
 280                 if ((err = lt_dlerror()))
 281                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload module %s: %s",
 282                                         ctx->info.plugin_name, err);
 283         }
 284
 285         plugin_info_clear(&ctx->info);
 286 } /* ctx_destroy */
 287
 288 static sdb_type_t ctx_type = {
 289         sizeof(ctx_t),
 290
 291         ctx_init,
 292         ctx_destroy
 293 };
 294
 295 static ctx_t *
 296 ctx_get(void)
 297 {
 298         if (! plugin_ctx_key_initialized)
 299                 ctx_key_init();
 300         return pthread_getspecific(plugin_ctx_key);
 301 } /* ctx_get */
 302
 303 static ctx_t *
 304 ctx_set(ctx_t *new)
 305 {
 306         ctx_t *old;
 307
 308         if (! plugin_ctx_key_initialized)
 309                 ctx_key_init();
 310
 311         old = pthread_getspecific(plugin_ctx_key);
 312         if (old)
 313                 sdb_object_deref(SDB_OBJ(old));
 314         if (new)
 315                 sdb_object_ref(SDB_OBJ(new));
 316         pthread_setspecific(plugin_ctx_key, new);
 317         return old;
 318 } /* ctx_set */
 319
 320 static ctx_t *
 321 ctx_create(const char *name)
 322 {
 323         ctx_t *ctx;
 324
 325         ctx = CTX(sdb_object_create(name, ctx_type));
 326         if (! ctx)
 327                 return NULL;
 328
 329         if (! plugin_ctx_key_initialized)
 330                 ctx_key_init();
 331         ctx_set(ctx);
 332         return ctx;
 333 } /* ctx_create */
 334
 335 static int
 336 plugin_cb_init(sdb_object_t *obj, va_list ap)
 337 {
 338         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 339         const char   *type = va_arg(ap, const char *);
 340         void     *callback = va_arg(ap, void *);
 341         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 342
 343         assert(list);
 344         assert(type);
 345         assert(obj);
 346
 347         if (sdb_llist_search_by_name(*list, obj->name)) {
 348                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 349                                 "has already been registered. Ignoring newly "
 350                                 "registered version.", type, obj->name);
 351                 return -1;
 352         }
 353
 354         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 355         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 356         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 357
 358         sdb_object_ref(ud);
 359         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 360         return 0;
 361 } /* plugin_cb_init */
 362
 363 static void
 364 plugin_cb_destroy(sdb_object_t *obj)
 365 {
 366         assert(obj);
 367         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 368         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 369 } /* plugin_cb_destroy */
 370
 371 static sdb_type_t sdb_plugin_cb_type = {
 372         sizeof(sdb_plugin_cb_t),
 373
 374         plugin_cb_init,
 375         plugin_cb_destroy
 376 };
 377
 378 static sdb_type_t sdb_plugin_collector_cb_type = {
 379         sizeof(sdb_plugin_collector_cb_t),
 380
 381         plugin_cb_init,
 382         plugin_cb_destroy
 383 };
 384
 385 static int
 386 module_init(const char *name, lt_dlhandle lh, sdb_plugin_info_t *info)
 387 {
 388         int (*mod_init)(sdb_plugin_info_t *);
 389         int status;
 390
 391         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 392         if (! mod_init) {
 393                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 394                                 "could not find symbol 'sdb_module_init'", name);
 395                 return -1;
 396         }
 397
 398         status = mod_init(info);
 399         if (status) {
 400                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 401                                 "module '%s'", name);
 402                 plugin_unregister_by_name(name);
 403                 return -1;
 404         }
 405         return 0;
 406 } /* module_init */
 407
 408 static int
 409 module_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 410 {
 411         char  base_name[name ? strlen(name) + 1 : 1];
 412         const char *name_ptr;
 413         char *tmp;
 414
 415         char filename[1024];
 416         lt_dlhandle lh;
 417
 418         ctx_t *ctx;
 419
 420         int status;
 421
 422         base_name[0] = '\0';
 423         name_ptr = name;
 424
 425         while ((tmp = strstr(name_ptr, "::"))) {
 426                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 427                 strcat(base_name, "/");
 428                 name_ptr = tmp + strlen("::");
 429         }
 430         strcat(base_name, name_ptr);
 431
 432         snprintf(filename, sizeof(filename), "%s/%s.so",
 433                         PKGLIBDIR, base_name);
 434         filename[sizeof(filename) - 1] = '\0';
 435
 436         if (access(filename, R_OK)) {
 437                 char errbuf[1024];
 438                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 439                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 440                 return -1;
 441         }
 442
 443         lt_dlinit();
 444         lt_dlerror();
 445
 446         lh = lt_dlopen(filename);
 447         if (! lh) {
 448                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 449                                 "The most common cause for this problem are missing "
 450                                 "dependencies.\n", name, lt_dlerror());
 451                 return -1;
 452         }
 453
 454         if (ctx_get())
 455                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 456
 457         ctx = ctx_create(name);
 458         if (! ctx) {
 459                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 460                 return -1;
 461         }
 462
 463         ctx->info.plugin_name = strdup(name);
 464         ctx->info.filename = strdup(filename);
 465         ctx->handle = lh;
 466
 467         if (plugin_ctx)
 468                 ctx->public = *plugin_ctx;
 469
 470         if ((status = module_init(name, lh, &ctx->info))) {
 471                 sdb_object_deref(SDB_OBJ(ctx));
 472                 return status;
 473         }
 474
 475         /* compare minor version */
 476         if ((ctx->info.version < 0)
 477                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 478                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 479                                 "plugin '%s' (%i.%i.%i) does not match our version "
 480                                 "(%i.%i.%i); this might cause problems",
 481                                 name, SDB_VERSION_DECODE(ctx->info.version),
 482                                 SDB_VERSION_DECODE(SDB_VERSION));
 483
 484         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 485
 486         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 487                         "plugin '%s' v%i (%s)\n\t%s\n\tLicense: %s",
 488                         INFO_GET(&ctx->info, name), ctx->info.plugin_version,
 489                         INFO_GET(&ctx->info, description),
 490                         INFO_GET(&ctx->info, copyright),
 491                         INFO_GET(&ctx->info, license));
 492
 493         /* any registered callbacks took ownership of the context */
 494         sdb_object_deref(SDB_OBJ(ctx));
 495
 496         /* reset */
 497         ctx_set(NULL);
 498         return 0;
 499 } /* module_load */
 500
 501 static int
 502 plugin_add_callback(sdb_llist_t **list, const char *type,
 503                 const char *name, void *callback, sdb_object_t *user_data)
 504 {
 505         sdb_object_t *obj;
 506
 507         if ((! name) || (! callback))
 508                 return -1;
 509
 510         assert(list);
 511
 512         if (! *list)
 513                 *list = sdb_llist_create();
 514         if (! *list)
 515                 return -1;
 516
 517         obj = sdb_object_create(name, sdb_plugin_cb_type,
 518                         list, type, callback, user_data);
 519         if (! obj)
 520                 return -1;
 521
 522         if (sdb_llist_append(*list, obj)) {
 523                 sdb_object_deref(obj);
 524                 return -1;
 525         }
 526
 527         /* pass control to the list */
 528         sdb_object_deref(obj);
 529
 530         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 531                         type, name);
 532         return 0;
 533 } /* plugin_add_callback */
 534
 535 /*
 536  * public API
 537  */
 538
 539 int
 540 sdb_plugin_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 541 {
 542         ctx_t *ctx;
 543
 544         if ((! name) || (! *name))
 545                 return -1;
 546
 547         if (! all_plugins) {
 548                 if (! (all_plugins = sdb_llist_create())) {
 549                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 550                                         "internal error while creating linked list", name);
 551                         return -1;
 552                 }
 553         }
 554
 555         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 556         if (ctx) {
 557                 /* plugin already loaded */
 558                 ++ctx->use_cnt;
 559                 return 0;
 560         }
 561
 562         return module_load(name, plugin_ctx);
 563 } /* sdb_plugin_load */
 564
 565 int
 566 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 567 {
 568         va_list ap;
 569
 570         if (! info)
 571                 return -1;
 572
 573         va_start(ap, type);
 574
 575         switch (type) {
 576                 case SDB_PLUGIN_INFO_NAME:
 577                         {
 578                                 char *name = va_arg(ap, char *);
 579                                 if (name) {
 580                                         if (info->name)
 581                                                 free(info->name);
 582                                         info->name = strdup(name);
 583                                 }
 584                         }
 585                         break;
 586                 case SDB_PLUGIN_INFO_DESC:
 587                         {
 588                                 char *desc = va_arg(ap, char *);
 589                                 if (desc) {
 590                                         if (info->description)
 591                                                 free(info->description);
 592                                         info->description = strdup(desc);
 593                                 }
 594                         }
 595                         break;
 596                 case SDB_PLUGIN_INFO_COPYRIGHT:
 597                         {
 598                                 char *copyright = va_arg(ap, char *);
 599                                 if (copyright)
 600                                         info->copyright = strdup(copyright);
 601                         }
 602                         break;
 603                 case SDB_PLUGIN_INFO_LICENSE:
 604                         {
 605                                 char *license = va_arg(ap, char *);
 606                                 if (license) {
 607                                         if (info->license)
 608                                                 free(info->license);
 609                                         info->license = strdup(license);
 610                                 }
 611                         }
 612                         break;
 613                 case SDB_PLUGIN_INFO_VERSION:
 614                         {
 615                                 int version = va_arg(ap, int);
 616                                 info->version = version;
 617                         }
 618                         break;
 619                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 620                         {
 621                                 int version = va_arg(ap, int);
 622                                 info->plugin_version = version;
 623                         }
 624                         break;
 625                 default:
 626                         va_end(ap);
 627                         return -1;
 628         }
 629
 630         va_end(ap);
 631         return 0;
 632 } /* sdb_plugin_set_info */
 633
 634 int
 635 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
 636 {
 637         return plugin_add_callback(&config_list, "init", name,
 638                         (void *)callback, NULL);
 639 } /* sdb_plugin_register_config */
 640
 641 int
 642 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 643                 sdb_object_t *user_data)
 644 {
 645         return plugin_add_callback(&init_list, "init", name,
 646                         (void *)callback, user_data);
 647 } /* sdb_plugin_register_init */
 648
 649 int
 650 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 651                 sdb_object_t *user_data)
 652 {
 653         return plugin_add_callback(&shutdown_list, "shutdown", name,
 654                         (void *)callback, user_data);
 655 } /* sdb_plugin_register_shutdown */
 656
 657 int
 658 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 659                 sdb_object_t *user_data)
 660 {
 661         return plugin_add_callback(&log_list, "log", name, (void *)callback,
 662                         user_data);
 663 } /* sdb_plugin_register_log */
 664
 665 int
 666 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 667                 sdb_object_t *user_data)
 668 {
 669         return plugin_add_callback(&cname_list, "cname", name, (void *)callback,
 670                         user_data);
 671 } /* sdb_plugin_register_cname */
 672
 673 int
 674 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 675                 const sdb_time_t *interval, sdb_object_t *user_data)
 676 {
 677         sdb_object_t *obj;
 678
 679         if ((! name) || (! callback))
 680                 return -1;
 681
 682         if (! collector_list)
 683                 collector_list = sdb_llist_create();
 684         if (! collector_list)
 685                 return -1;
 686
 687         obj = sdb_object_create(name, sdb_plugin_collector_cb_type,
 688                         &collector_list, "collector", callback, user_data);
 689         if (! obj)
 690                 return -1;
 691
 692         if (interval)
 693                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 694         else {
 695                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 696
 697                 if (tmp > 0)
 698                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 699                 else
 700                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 701         }
 702
 703         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 704                 char errbuf[1024];
 705                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 706                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 707                 sdb_object_deref(obj);
 708                 return -1;
 709         }
 710
 711         if (sdb_llist_insert_sorted(collector_list, obj,
 712                                 plugin_cmp_next_update)) {
 713                 sdb_object_deref(obj);
 714                 return -1;
 715         }
 716
 717         /* pass control to the list */
 718         sdb_object_deref(obj);
 719
 720         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 721                         "(interval = %.3fs).", name,
 722                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 723         return 0;
 724 } /* sdb_plugin_register_collector */
 725
 726 sdb_plugin_ctx_t
 727 sdb_plugin_get_ctx(void)
 728 {
 729         ctx_t *c;
 730
 731         c = ctx_get();
 732         if (! c) {
 733                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 734                                 "context outside a plugin");
 735                 return plugin_default_ctx;
 736         }
 737         return c->public;
 738 } /* sdb_plugin_get_ctx */
 739
 740 int
 741 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 742 {
 743         ctx_t *c;
 744
 745         c = ctx_get();
 746         if (! c) {
 747                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 748                                 "context outside a plugin");
 749                 return -1;
 750         }
 751
 752         if (old)
 753                 *old = c->public;
 754         c->public = ctx;
 755         return 0;
 756 } /* sdb_plugin_set_ctx */
 757
 758 int
 759 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 760 {
 761         sdb_plugin_cb_t *plugin;
 762         sdb_plugin_config_cb callback;
 763
 764         ctx_t *old_ctx;
 765
 766         int status;
 767
 768         if ((! name) || (! ci))
 769                 return -1;
 770
 771         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 772         if (! plugin) {
 773                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 774                 if (! ctx)
 775                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' not loaded.", name);
 776                 else
 777                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 778                                         "a config callback.", name);
 779                 errno = ENOENT;
 780                 return -1;
 781         }
 782
 783         old_ctx = ctx_set(plugin->cb_ctx);
 784         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 785         status = callback(ci);
 786         ctx_set(old_ctx);
 787         return status;
 788 } /* sdb_plugin_configure */
 789
 790 int
 791 sdb_plugin_init_all(void)
 792 {
 793         sdb_llist_iter_t *iter;
 794         int ret = 0;
 795
 796         iter = sdb_llist_get_iter(init_list);
 797         while (sdb_llist_iter_has_next(iter)) {
 798                 sdb_plugin_cb_t *cb;
 799                 sdb_plugin_init_cb callback;
 800                 ctx_t *old_ctx;
 801
 802                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 803                 assert(obj);
 804                 cb = SDB_PLUGIN_CB(obj);
 805
 806                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 807
 808                 old_ctx = ctx_set(cb->cb_ctx);
 809                 if (callback(cb->cb_user_data)) {
 810                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 811                                         "'%s'. Unregistering all callbacks.", obj->name);
 812                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 813                         ++ret;
 814                 }
 815                 ctx_set(old_ctx);
 816         }
 817         sdb_llist_iter_destroy(iter);
 818         return ret;
 819 } /* sdb_plugin_init_all */
 820
 821 int
 822 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 823 {
 824         if (! collector_list) {
 825                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 826                                 "Quiting main loop.");
 827                 return -1;
 828         }
 829
 830         if (! loop)
 831                 return -1;
 832
 833         while (loop->do_loop) {
 834                 sdb_plugin_collector_cb callback;
 835                 ctx_t *old_ctx;
 836
 837                 sdb_time_t interval, now;
 838
 839                 sdb_object_t *obj = sdb_llist_shift(collector_list);
 840                 if (! obj)
 841                         return -1;
 842
 843                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
 844
 845                 if (! (now = sdb_gettime())) {
 846                         char errbuf[1024];
 847                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 848                                         "time in collector main loop: %s",
 849                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 850                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 851                 }
 852
 853                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 854                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
 855
 856                         errno = 0;
 857                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
 858                                 if (errno != EINTR) {
 859                                         char errbuf[1024];
 860                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
 861                                                         "in collector main loop: %s",
 862                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 863                                         return -1;
 864                                 }
 865                                 errno = 0;
 866                         }
 867
 868                         if (! loop->do_loop)
 869                                 return 0;
 870                 }
 871
 872                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
 873                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
 874                         /* XXX */
 875                 }
 876                 ctx_set(old_ctx);
 877
 878                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
 879                 if (! interval)
 880                         interval = loop->default_interval;
 881                 if (! interval) {
 882                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
 883                                         "for plugin '%s'; skipping any further "
 884                                         "iterations.", obj->name);
 885                         sdb_object_deref(obj);
 886                         continue;
 887                 }
 888
 889                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
 890
 891                 if (! (now = sdb_gettime())) {
 892                         char errbuf[1024];
 893                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 894                                         "time in collector main loop: %s",
 895                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 896                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 897                 }
 898
 899                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 900                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
 901                                         "long; skipping iterations to keep up.",
 902                                         obj->name);
 903                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
 904                 }
 905
 906                 if (sdb_llist_insert_sorted(collector_list, obj,
 907                                         plugin_cmp_next_update)) {
 908                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
 909                                         "plugin '%s' into collector list. Unable to further "
 910                                         "use the plugin.",
 911                                         obj->name);
 912                         sdb_object_deref(obj);
 913                         return -1;
 914                 }
 915
 916                 /* pass control back to the list */
 917                 sdb_object_deref(obj);
 918         }
 919         return 0;
 920 } /* sdb_plugin_read_loop */
 921
 922 char *
 923 sdb_plugin_cname(char *hostname)
 924 {
 925         sdb_llist_iter_t *iter;
 926
 927         if (! hostname)
 928                 return NULL;
 929
 930         if (! cname_list)
 931                 return hostname;
 932
 933         iter = sdb_llist_get_iter(cname_list);
 934         while (sdb_llist_iter_has_next(iter)) {
 935                 sdb_plugin_cname_cb callback;
 936                 char *cname;
 937
 938                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 939                 assert(obj);
 940
 941                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 942                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
 943                 if (cname) {
 944                         free(hostname);
 945                         hostname = cname;
 946                 }
 947                 /* else: don't change hostname */
 948         }
 949         sdb_llist_iter_destroy(iter);
 950         return hostname;
 951 } /* sdb_plugin_cname */
 952
 953 int
 954 sdb_plugin_log(int prio, const char *msg)
 955 {
 956         sdb_llist_iter_t *iter;
 957         int ret = -1;
 958
 959         if (! msg)
 960                 return 0;
 961
 962         if (! log_list)
 963                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
 964
 965         iter = sdb_llist_get_iter(log_list);
 966         while (sdb_llist_iter_has_next(iter)) {
 967                 sdb_plugin_log_cb callback;
 968                 int tmp;
 969
 970                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 971                 assert(obj);
 972
 973                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
 974                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
 975                 if (tmp > ret)
 976                         ret = tmp;
 977         }
 978         sdb_llist_iter_destroy(iter);
 979         return ret;
 980 } /* sdb_plugin_log */
 981
 982 int
 983 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
 984 {
 985         sdb_strbuf_t *buf;
 986         int ret;
 987
 988         if (! fmt)
 989                 return 0;
 990
 991         buf = sdb_strbuf_create(64);
 992         if (! buf) {
 993                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
 994                 ret += vfprintf(stderr, fmt, ap);
 995                 return ret;
 996         }
 997
 998         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
 999                 sdb_strbuf_destroy(buf);
1000                 return -1;
1001         }
1002
1003         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1004         sdb_strbuf_destroy(buf);
1005         return ret;
1006 } /* sdb_plugin_vlogf */
1007
1008 int
1009 sdb_plugin_logf(int prio, const char *fmt, ...)
1010 {
1011         va_list ap;
1012         int ret;
1013
1014         if (! fmt)
1015                 return 0;
1016
1017         va_start(ap, fmt);
1018         ret = sdb_plugin_vlogf(prio, fmt, ap);
1019         va_end(ap);
1020         return ret;
1021 } /* sdb_plugin_logf */
1022
1023 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1024