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 static struct {
 141         const char   *type;
 142         sdb_llist_t **list;
 143 } all_lists[] = {
 144         { "config",    &config_list },
 145         { "init",      &init_list },
 146         { "collector", &collector_list },
 147         { "cname",     &cname_list },
 148         { "shutdown",  &shutdown_list },
 149         { "log",       &log_list },
 150 };
 151
 152 /*
 153  * private helper functions
 154  */
 155
 156 static void
 157 plugin_info_clear(sdb_plugin_info_t *info)
 158 {
 159         sdb_plugin_info_t empty_info = SDB_PLUGIN_INFO_INIT;
 160         if (! info)
 161                 return;
 162
 163         if (info->plugin_name)
 164                 free(info->plugin_name);
 165         if (info->filename)
 166                 free(info->filename);
 167
 168         if (info->name)
 169                 free(info->name);
 170         if (info->description)
 171                 free(info->description);
 172         if (info->copyright)
 173                 free(info->copyright);
 174         if (info->license)
 175                 free(info->license);
 176
 177         *info = empty_info;
 178 } /* plugin_info_clear */
 179
 180 static void
 181 ctx_key_init(void)
 182 {
 183         if (plugin_ctx_key_initialized)
 184                 return;
 185
 186         pthread_key_create(&plugin_ctx_key, /* destructor */ NULL);
 187         plugin_ctx_key_initialized = 1;
 188 } /* ctx_key_init */
 189
 190 static int
 191 plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
 192 {
 193         const sdb_plugin_collector_cb_t *ccb1
 194                 = (const sdb_plugin_collector_cb_t *)a;
 195         const sdb_plugin_collector_cb_t *ccb2
 196                 = (const sdb_plugin_collector_cb_t *)b;
 197
 198         assert(ccb1 && ccb2);
 199
 200         return (ccb1->ccb_next_update > ccb2->ccb_next_update)
 201                 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
 202                 ? -1 : 0;
 203 } /* plugin_cmp_next_update */
 204
 205 static int
 206 plugin_lookup_by_name(const sdb_object_t *obj, const void *id)
 207 {
 208         const sdb_plugin_cb_t *cb = SDB_CONST_PLUGIN_CB(obj);
 209         const char *name = id;
 210
 211         assert(cb && id);
 212
 213         /* when a plugin was registered from outside a plugin (e.g. the core),
 214          * we don't have a plugin context */
 215         if (! cb->cb_ctx)
 216                 return 1;
 217
 218         if (!strcasecmp(cb->cb_ctx->info.plugin_name, name))
 219                 return 0;
 220         return 1;
 221 } /* plugin_lookup_by_name */
 222
 223 /* since this function is called from sdb_plugin_reconfigure_finish()
 224  * when iterating through all_plugins, we may not do any additional
 225  * modifications to all_plugins except for the optional removal */
 226 static void
 227 plugin_unregister_by_name(const char *plugin_name)
 228 {
 229         sdb_object_t *obj;
 230         size_t i;
 231
 232         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 233                 const char  *type =  all_lists[i].type;
 234                 sdb_llist_t *list = *all_lists[i].list;
 235
 236                 while (1) {
 237                         sdb_plugin_cb_t *cb;
 238
 239                         cb = SDB_PLUGIN_CB(sdb_llist_remove(list,
 240                                                 plugin_lookup_by_name, plugin_name));
 241                         if (! cb)
 242                                 break;
 243
 244                         assert(cb->cb_ctx);
 245
 246                         sdb_log(SDB_LOG_INFO, "core: Unregistering "
 247                                         "%s callback '%s' (module %s)", type, cb->super.name,
 248                                         cb->cb_ctx->info.plugin_name);
 249                         sdb_object_deref(SDB_OBJ(cb));
 250                 }
 251         }
 252
 253         obj = sdb_llist_search_by_name(all_plugins, plugin_name);
 254         /* when called from sdb_plugin_reconfigure_finish, the object has already
 255          * been removed from the list */
 256         if (obj && (obj->ref_cnt <= 1)) {
 257                 sdb_llist_remove_by_name(all_plugins, plugin_name);
 258                 sdb_object_deref(obj);
 259         }
 260         /* else: other callbacks still reference it */
 261 } /* plugin_unregister_by_name */
 262
 263 static void
 264 plugin_unregister_all(void)
 265 {
 266         size_t i;
 267
 268         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 269                 const char  *type =  all_lists[i].type;
 270                 sdb_llist_t *list = *all_lists[i].list;
 271
 272                 size_t len = sdb_llist_len(list);
 273
 274                 if (! len)
 275                         continue;
 276
 277                 sdb_llist_clear(list);
 278                 sdb_log(SDB_LOG_INFO, "core: Unregistered %zu %s callback%s",
 279                                 len, type, len == 1 ? "" : "s");
 280         }
 281 } /* plugin_unregister_all */
 282
 283 /*
 284  * private types
 285  */
 286
 287 static int
 288 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 289 {
 290         ctx_t *ctx = CTX(obj);
 291
 292         assert(ctx);
 293
 294         ctx->public = plugin_default_ctx;
 295         ctx->info = plugin_default_info;
 296         ctx->handle = NULL;
 297         ctx->use_cnt = 1;
 298         return 0;
 299 } /* ctx_init */
 300
 301 static void
 302 ctx_destroy(sdb_object_t *obj)
 303 {
 304         ctx_t *ctx = CTX(obj);
 305
 306         if (ctx->handle) {
 307                 const char *err;
 308
 309                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s",
 310                                 ctx->info.plugin_name);
 311
 312                 lt_dlerror();
 313                 lt_dlclose(ctx->handle);
 314                 if ((err = lt_dlerror()))
 315                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload module %s: %s",
 316                                         ctx->info.plugin_name, err);
 317         }
 318
 319         plugin_info_clear(&ctx->info);
 320 } /* ctx_destroy */
 321
 322 static sdb_type_t ctx_type = {
 323         sizeof(ctx_t),
 324
 325         ctx_init,
 326         ctx_destroy
 327 };
 328
 329 static ctx_t *
 330 ctx_get(void)
 331 {
 332         if (! plugin_ctx_key_initialized)
 333                 ctx_key_init();
 334         return pthread_getspecific(plugin_ctx_key);
 335 } /* ctx_get */
 336
 337 static ctx_t *
 338 ctx_set(ctx_t *new)
 339 {
 340         ctx_t *old;
 341
 342         if (! plugin_ctx_key_initialized)
 343                 ctx_key_init();
 344
 345         old = pthread_getspecific(plugin_ctx_key);
 346         if (old)
 347                 sdb_object_deref(SDB_OBJ(old));
 348         if (new)
 349                 sdb_object_ref(SDB_OBJ(new));
 350         pthread_setspecific(plugin_ctx_key, new);
 351         return old;
 352 } /* ctx_set */
 353
 354 static ctx_t *
 355 ctx_create(const char *name)
 356 {
 357         ctx_t *ctx;
 358
 359         ctx = CTX(sdb_object_create(name, ctx_type));
 360         if (! ctx)
 361                 return NULL;
 362
 363         if (! plugin_ctx_key_initialized)
 364                 ctx_key_init();
 365         ctx_set(ctx);
 366         return ctx;
 367 } /* ctx_create */
 368
 369 static int
 370 plugin_cb_init(sdb_object_t *obj, va_list ap)
 371 {
 372         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 373         const char   *type = va_arg(ap, const char *);
 374         void     *callback = va_arg(ap, void *);
 375         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 376
 377         assert(list);
 378         assert(type);
 379         assert(obj);
 380
 381         if (sdb_llist_search_by_name(*list, obj->name)) {
 382                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 383                                 "has already been registered. Ignoring newly "
 384                                 "registered version.", type, obj->name);
 385                 return -1;
 386         }
 387
 388         /* cb_ctx may be NULL if the plugin was not registered by a plugin */
 389
 390         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 391         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 392         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 393
 394         sdb_object_ref(ud);
 395         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 396         return 0;
 397 } /* plugin_cb_init */
 398
 399 static void
 400 plugin_cb_destroy(sdb_object_t *obj)
 401 {
 402         assert(obj);
 403         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 404         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 405 } /* plugin_cb_destroy */
 406
 407 static sdb_type_t sdb_plugin_cb_type = {
 408         sizeof(sdb_plugin_cb_t),
 409
 410         plugin_cb_init,
 411         plugin_cb_destroy
 412 };
 413
 414 static sdb_type_t sdb_plugin_collector_cb_type = {
 415         sizeof(sdb_plugin_collector_cb_t),
 416
 417         plugin_cb_init,
 418         plugin_cb_destroy
 419 };
 420
 421 static int
 422 module_init(const char *name, lt_dlhandle lh, sdb_plugin_info_t *info)
 423 {
 424         int (*mod_init)(sdb_plugin_info_t *);
 425         int status;
 426
 427         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 428         if (! mod_init) {
 429                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 430                                 "could not find symbol 'sdb_module_init'", name);
 431                 return -1;
 432         }
 433
 434         status = mod_init(info);
 435         if (status) {
 436                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 437                                 "module '%s'", name);
 438                 plugin_unregister_by_name(name);
 439                 return -1;
 440         }
 441         return 0;
 442 } /* module_init */
 443
 444 static int
 445 module_load(const char *basedir, const char *name,
 446                 const sdb_plugin_ctx_t *plugin_ctx)
 447 {
 448         char  base_name[name ? strlen(name) + 1 : 1];
 449         const char *name_ptr;
 450         char *tmp;
 451
 452         char filename[1024];
 453         lt_dlhandle lh;
 454
 455         ctx_t *ctx;
 456
 457         int status;
 458
 459         assert(name);
 460
 461         base_name[0] = '\0';
 462         name_ptr = name;
 463
 464         while ((tmp = strstr(name_ptr, "::"))) {
 465                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 466                 strcat(base_name, "/");
 467                 name_ptr = tmp + strlen("::");
 468         }
 469         strcat(base_name, name_ptr);
 470
 471         if (! basedir)
 472                 basedir = PKGLIBDIR;
 473
 474         snprintf(filename, sizeof(filename), "%s/%s.so", basedir, base_name);
 475         filename[sizeof(filename) - 1] = '\0';
 476
 477         if (access(filename, R_OK)) {
 478                 char errbuf[1024];
 479                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 480                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 481                 return -1;
 482         }
 483
 484         lt_dlinit();
 485         lt_dlerror();
 486
 487         lh = lt_dlopen(filename);
 488         if (! lh) {
 489                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 490                                 "The most common cause for this problem are missing "
 491                                 "dependencies.\n", name, lt_dlerror());
 492                 return -1;
 493         }
 494
 495         if (ctx_get())
 496                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 497
 498         ctx = ctx_create(name);
 499         if (! ctx) {
 500                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 501                 return -1;
 502         }
 503
 504         ctx->info.plugin_name = strdup(name);
 505         ctx->info.filename = strdup(filename);
 506         ctx->handle = lh;
 507
 508         if (plugin_ctx)
 509                 ctx->public = *plugin_ctx;
 510
 511         if ((status = module_init(name, lh, &ctx->info))) {
 512                 sdb_object_deref(SDB_OBJ(ctx));
 513                 return status;
 514         }
 515
 516         /* compare minor version */
 517         if ((ctx->info.version < 0)
 518                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 519                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 520                                 "plugin '%s' (%i.%i.%i) does not match our version "
 521                                 "(%i.%i.%i); this might cause problems",
 522                                 name, SDB_VERSION_DECODE(ctx->info.version),
 523                                 SDB_VERSION_DECODE(SDB_VERSION));
 524
 525         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 526
 527         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 528                         "plugin '%s' v%i (%s)\n\t%s\n\tLicense: %s",
 529                         INFO_GET(&ctx->info, name), ctx->info.plugin_version,
 530                         INFO_GET(&ctx->info, description),
 531                         INFO_GET(&ctx->info, copyright),
 532                         INFO_GET(&ctx->info, license));
 533
 534         /* any registered callbacks took ownership of the context */
 535         sdb_object_deref(SDB_OBJ(ctx));
 536
 537         /* reset */
 538         ctx_set(NULL);
 539         return 0;
 540 } /* module_load */
 541
 542 static int
 543 plugin_add_callback(sdb_llist_t **list, const char *type,
 544                 const char *name, void *callback, sdb_object_t *user_data)
 545 {
 546         sdb_object_t *obj;
 547
 548         if ((! name) || (! callback))
 549                 return -1;
 550
 551         assert(list);
 552
 553         if (! *list)
 554                 *list = sdb_llist_create();
 555         if (! *list)
 556                 return -1;
 557
 558         obj = sdb_object_create(name, sdb_plugin_cb_type,
 559                         list, type, callback, user_data);
 560         if (! obj)
 561                 return -1;
 562
 563         if (sdb_llist_append(*list, obj)) {
 564                 sdb_object_deref(obj);
 565                 return -1;
 566         }
 567
 568         /* pass control to the list */
 569         sdb_object_deref(obj);
 570
 571         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 572                         type, name);
 573         return 0;
 574 } /* plugin_add_callback */
 575
 576 /*
 577  * public API
 578  */
 579
 580 int
 581 sdb_plugin_load(const char *basedir, const char *name,
 582                 const sdb_plugin_ctx_t *plugin_ctx)
 583 {
 584         ctx_t *ctx;
 585
 586         int status;
 587
 588         if ((! name) || (! *name))
 589                 return -1;
 590
 591         if (! all_plugins) {
 592                 if (! (all_plugins = sdb_llist_create())) {
 593                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 594                                         "internal error while creating linked list", name);
 595                         return -1;
 596                 }
 597         }
 598
 599         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 600         if (ctx) {
 601                 /* plugin already loaded */
 602                 if (! ctx->use_cnt) {
 603                         /* reloading plugin */
 604                         ctx_t *old_ctx = ctx_set(ctx);
 605
 606                         status = module_init(ctx->info.plugin_name, ctx->handle, NULL);
 607                         if (status)
 608                                 return status;
 609
 610                         sdb_log(SDB_LOG_INFO, "core: Successfully reloaded plugin "
 611                                         "'%s' (%s)", INFO_GET(&ctx->info, name),
 612                                         INFO_GET(&ctx->info, description));
 613                         ctx_set(old_ctx);
 614                 }
 615                 ++ctx->use_cnt;
 616                 return 0;
 617         }
 618
 619         return module_load(basedir, name, plugin_ctx);
 620 } /* sdb_plugin_load */
 621
 622 int
 623 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 624 {
 625         va_list ap;
 626
 627         if (! info)
 628                 return -1;
 629
 630         va_start(ap, type);
 631
 632         switch (type) {
 633                 case SDB_PLUGIN_INFO_NAME:
 634                         {
 635                                 char *name = va_arg(ap, char *);
 636                                 if (name) {
 637                                         if (info->name)
 638                                                 free(info->name);
 639                                         info->name = strdup(name);
 640                                 }
 641                         }
 642                         break;
 643                 case SDB_PLUGIN_INFO_DESC:
 644                         {
 645                                 char *desc = va_arg(ap, char *);
 646                                 if (desc) {
 647                                         if (info->description)
 648                                                 free(info->description);
 649                                         info->description = strdup(desc);
 650                                 }
 651                         }
 652                         break;
 653                 case SDB_PLUGIN_INFO_COPYRIGHT:
 654                         {
 655                                 char *copyright = va_arg(ap, char *);
 656                                 if (copyright)
 657                                         info->copyright = strdup(copyright);
 658                         }
 659                         break;
 660                 case SDB_PLUGIN_INFO_LICENSE:
 661                         {
 662                                 char *license = va_arg(ap, char *);
 663                                 if (license) {
 664                                         if (info->license)
 665                                                 free(info->license);
 666                                         info->license = strdup(license);
 667                                 }
 668                         }
 669                         break;
 670                 case SDB_PLUGIN_INFO_VERSION:
 671                         {
 672                                 int version = va_arg(ap, int);
 673                                 info->version = version;
 674                         }
 675                         break;
 676                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 677                         {
 678                                 int version = va_arg(ap, int);
 679                                 info->plugin_version = version;
 680                         }
 681                         break;
 682                 default:
 683                         va_end(ap);
 684                         return -1;
 685         }
 686
 687         va_end(ap);
 688         return 0;
 689 } /* sdb_plugin_set_info */
 690
 691 int
 692 sdb_plugin_register_config(sdb_plugin_config_cb callback)
 693 {
 694         ctx_t *ctx = ctx_get();
 695
 696         if (! ctx) {
 697                 sdb_log(SDB_LOG_ERR, "core: Invalid attempt to register a "
 698                                 "config callback from outside a plugin");
 699                 return -1;
 700         }
 701         return plugin_add_callback(&config_list, "init", ctx->info.plugin_name,
 702                         (void *)callback, NULL);
 703 } /* sdb_plugin_register_config */
 704
 705 int
 706 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 707                 sdb_object_t *user_data)
 708 {
 709         return plugin_add_callback(&init_list, "init", name,
 710                         (void *)callback, user_data);
 711 } /* sdb_plugin_register_init */
 712
 713 int
 714 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 715                 sdb_object_t *user_data)
 716 {
 717         return plugin_add_callback(&shutdown_list, "shutdown", name,
 718                         (void *)callback, user_data);
 719 } /* sdb_plugin_register_shutdown */
 720
 721 int
 722 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 723                 sdb_object_t *user_data)
 724 {
 725         return plugin_add_callback(&log_list, "log", name, (void *)callback,
 726                         user_data);
 727 } /* sdb_plugin_register_log */
 728
 729 int
 730 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 731                 sdb_object_t *user_data)
 732 {
 733         return plugin_add_callback(&cname_list, "cname", name, (void *)callback,
 734                         user_data);
 735 } /* sdb_plugin_register_cname */
 736
 737 int
 738 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 739                 const sdb_time_t *interval, sdb_object_t *user_data)
 740 {
 741         sdb_object_t *obj;
 742
 743         if ((! name) || (! callback))
 744                 return -1;
 745
 746         if (! collector_list)
 747                 collector_list = sdb_llist_create();
 748         if (! collector_list)
 749                 return -1;
 750
 751         obj = sdb_object_create(name, sdb_plugin_collector_cb_type,
 752                         &collector_list, "collector", callback, user_data);
 753         if (! obj)
 754                 return -1;
 755
 756         if (interval)
 757                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 758         else {
 759                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 760
 761                 if (tmp > 0)
 762                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 763                 else
 764                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 765         }
 766
 767         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 768                 char errbuf[1024];
 769                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 770                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 771                 sdb_object_deref(obj);
 772                 return -1;
 773         }
 774
 775         if (sdb_llist_insert_sorted(collector_list, obj,
 776                                 plugin_cmp_next_update)) {
 777                 sdb_object_deref(obj);
 778                 return -1;
 779         }
 780
 781         /* pass control to the list */
 782         sdb_object_deref(obj);
 783
 784         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 785                         "(interval = %.3fs).", name,
 786                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 787         return 0;
 788 } /* sdb_plugin_register_collector */
 789
 790 sdb_plugin_ctx_t
 791 sdb_plugin_get_ctx(void)
 792 {
 793         ctx_t *c;
 794
 795         c = ctx_get();
 796         if (! c) {
 797                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 798                                 "context outside a plugin");
 799                 return plugin_default_ctx;
 800         }
 801         return c->public;
 802 } /* sdb_plugin_get_ctx */
 803
 804 int
 805 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 806 {
 807         ctx_t *c;
 808
 809         c = ctx_get();
 810         if (! c) {
 811                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 812                                 "context outside a plugin");
 813                 return -1;
 814         }
 815
 816         if (old)
 817                 *old = c->public;
 818         c->public = ctx;
 819         return 0;
 820 } /* sdb_plugin_set_ctx */
 821
 822 int
 823 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 824 {
 825         sdb_plugin_cb_t *plugin;
 826         sdb_plugin_config_cb callback;
 827
 828         ctx_t *old_ctx;
 829
 830         int status;
 831
 832         if ((! name) || (! ci))
 833                 return -1;
 834
 835         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 836         if (! plugin) {
 837                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 838                 if (! ctx)
 839                         sdb_log(SDB_LOG_ERR, "core: Cannot configure unknown "
 840                                         "plugin '%s'. Missing 'LoadPlugin \"%s\"'?",
 841                                         name, name);
 842                 else
 843                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 844                                         "a config callback.", name);
 845                 errno = ENOENT;
 846                 return -1;
 847         }
 848
 849         old_ctx = ctx_set(plugin->cb_ctx);
 850         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 851         status = callback(ci);
 852         ctx_set(old_ctx);
 853         return status;
 854 } /* sdb_plugin_configure */
 855
 856 int
 857 sdb_plugin_reconfigure_init(void)
 858 {
 859         sdb_llist_iter_t *iter;
 860
 861         iter = sdb_llist_get_iter(config_list);
 862         if (config_list && (! iter))
 863                 return -1;
 864
 865         /* deconfigure all plugins */
 866         while (sdb_llist_iter_has_next(iter)) {
 867                 sdb_plugin_cb_t *plugin;
 868                 sdb_plugin_config_cb callback;
 869                 ctx_t *old_ctx;
 870
 871                 plugin = SDB_PLUGIN_CB(sdb_llist_iter_get_next(iter));
 872                 old_ctx = ctx_set(plugin->cb_ctx);
 873                 callback = (sdb_plugin_config_cb)plugin->cb_callback;
 874                 callback(NULL);
 875                 ctx_set(old_ctx);
 876         }
 877         sdb_llist_iter_destroy(iter);
 878
 879         iter = sdb_llist_get_iter(all_plugins);
 880         if (all_plugins && (! iter))
 881                 return -1;
 882
 883         /* record all plugins as being unused */
 884         while (sdb_llist_iter_has_next(iter))
 885                 CTX(sdb_llist_iter_get_next(iter))->use_cnt = 0;
 886         sdb_llist_iter_destroy(iter);
 887
 888         plugin_unregister_all();
 889         return 0;
 890 } /* sdb_plugin_reconfigure_init */
 891
 892 int
 893 sdb_plugin_reconfigure_finish(void)
 894 {
 895         sdb_llist_iter_t *iter;
 896
 897         iter = sdb_llist_get_iter(all_plugins);
 898         if (all_plugins && (! iter))
 899                 return -1;
 900
 901         while (sdb_llist_iter_has_next(iter)) {
 902                 ctx_t *ctx = CTX(sdb_llist_iter_get_next(iter));
 903                 if (ctx->use_cnt)
 904                         continue;
 905
 906                 sdb_log(SDB_LOG_INFO, "core: Module %s no longer in use",
 907                                 ctx->info.plugin_name);
 908                 sdb_llist_iter_remove_current(iter);
 909                 plugin_unregister_by_name(ctx->info.plugin_name);
 910                 sdb_object_deref(SDB_OBJ(ctx));
 911         }
 912         sdb_llist_iter_destroy(iter);
 913         return 0;
 914 } /* sdb_plugin_reconfigure_finish */
 915
 916 int
 917 sdb_plugin_init_all(void)
 918 {
 919         sdb_llist_iter_t *iter;
 920         int ret = 0;
 921
 922         iter = sdb_llist_get_iter(init_list);
 923         while (sdb_llist_iter_has_next(iter)) {
 924                 sdb_plugin_cb_t *cb;
 925                 sdb_plugin_init_cb callback;
 926                 ctx_t *old_ctx;
 927
 928                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 929                 assert(obj);
 930                 cb = SDB_PLUGIN_CB(obj);
 931
 932                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 933
 934                 old_ctx = ctx_set(cb->cb_ctx);
 935                 if (callback(cb->cb_user_data)) {
 936                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 937                                         "'%s'. Unregistering all callbacks.", obj->name);
 938                         ctx_set(old_ctx);
 939                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 940                         ++ret;
 941                 }
 942                 else
 943                         ctx_set(old_ctx);
 944         }
 945         sdb_llist_iter_destroy(iter);
 946         return ret;
 947 } /* sdb_plugin_init_all */
 948
 949 int
 950 sdb_plugin_shutdown_all(void)
 951 {
 952         sdb_llist_iter_t *iter;
 953         int ret = 0;
 954
 955         iter = sdb_llist_get_iter(shutdown_list);
 956         while (sdb_llist_iter_has_next(iter)) {
 957                 sdb_plugin_cb_t *cb;
 958                 sdb_plugin_shutdown_cb callback;
 959                 ctx_t *old_ctx;
 960
 961                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 962                 assert(obj);
 963                 cb = SDB_PLUGIN_CB(obj);
 964
 965                 callback = (sdb_plugin_shutdown_cb)cb->cb_callback;
 966
 967                 old_ctx = ctx_set(cb->cb_ctx);
 968                 if (callback(cb->cb_user_data)) {
 969                         sdb_log(SDB_LOG_ERR, "core: Failed to shutdown plugin '%s'.",
 970                                         obj->name);
 971                         ++ret;
 972                 }
 973                 ctx_set(old_ctx);
 974         }
 975         sdb_llist_iter_destroy(iter);
 976         return ret;
 977 } /* sdb_plugin_shutdown_all */
 978
 979 int
 980 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 981 {
 982         if (! collector_list) {
 983                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 984                                 "Quiting main loop.");
 985                 return -1;
 986         }
 987
 988         if (! loop)
 989                 return -1;
 990
 991         while (loop->do_loop) {
 992                 sdb_plugin_collector_cb callback;
 993                 ctx_t *old_ctx;
 994
 995                 sdb_time_t interval, now;
 996
 997                 sdb_object_t *obj = sdb_llist_shift(collector_list);
 998                 if (! obj)
 999                         return -1;
1000
1001                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
1002
1003                 if (! (now = sdb_gettime())) {
1004                         char errbuf[1024];
1005                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1006                                         "time in collector main loop: %s",
1007                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1008                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1009                 }
1010
1011                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1012                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
1013
1014                         errno = 0;
1015                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
1016                                 if (errno != EINTR) {
1017                                         char errbuf[1024];
1018                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
1019                                                         "in collector main loop: %s",
1020                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1021                                         sdb_llist_insert_sorted(collector_list, obj,
1022                                                         plugin_cmp_next_update);
1023                                         sdb_object_deref(obj);
1024                                         return -1;
1025                                 }
1026                                 errno = 0;
1027                         }
1028
1029                         if (! loop->do_loop) {
1030                                 /* put back; don't worry about errors */
1031                                 sdb_llist_insert_sorted(collector_list, obj,
1032                                                 plugin_cmp_next_update);
1033                                 sdb_object_deref(obj);
1034                                 return 0;
1035                         }
1036                 }
1037
1038                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
1039                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
1040                         /* XXX */
1041                 }
1042                 ctx_set(old_ctx);
1043
1044                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
1045                 if (! interval)
1046                         interval = loop->default_interval;
1047                 if (! interval) {
1048                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
1049                                         "for plugin '%s'; skipping any further "
1050                                         "iterations.", obj->name);
1051                         sdb_object_deref(obj);
1052                         continue;
1053                 }
1054
1055                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
1056
1057                 if (! (now = sdb_gettime())) {
1058                         char errbuf[1024];
1059                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1060                                         "time in collector main loop: %s",
1061                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1062                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1063                 }
1064
1065                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1066                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
1067                                         "long; skipping iterations to keep up.",
1068                                         obj->name);
1069                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
1070                 }
1071
1072                 if (sdb_llist_insert_sorted(collector_list, obj,
1073                                         plugin_cmp_next_update)) {
1074                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
1075                                         "plugin '%s' into collector list. Unable to further "
1076                                         "use the plugin.",
1077                                         obj->name);
1078                         sdb_object_deref(obj);
1079                         return -1;
1080                 }
1081
1082                 /* pass control back to the list */
1083                 sdb_object_deref(obj);
1084         }
1085         return 0;
1086 } /* sdb_plugin_read_loop */
1087
1088 char *
1089 sdb_plugin_cname(char *hostname)
1090 {
1091         sdb_llist_iter_t *iter;
1092
1093         if (! hostname)
1094                 return NULL;
1095
1096         if (! cname_list)
1097                 return hostname;
1098
1099         iter = sdb_llist_get_iter(cname_list);
1100         while (sdb_llist_iter_has_next(iter)) {
1101                 sdb_plugin_cname_cb callback;
1102                 char *cname;
1103
1104                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1105                 assert(obj);
1106
1107                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1108                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
1109                 if (cname) {
1110                         free(hostname);
1111                         hostname = cname;
1112                 }
1113                 /* else: don't change hostname */
1114         }
1115         sdb_llist_iter_destroy(iter);
1116         return hostname;
1117 } /* sdb_plugin_cname */
1118
1119 int
1120 sdb_plugin_log(int prio, const char *msg)
1121 {
1122         sdb_llist_iter_t *iter;
1123         int ret = -1;
1124
1125         _Bool logged = 0;
1126
1127         if (! msg)
1128                 return 0;
1129
1130         iter = sdb_llist_get_iter(log_list);
1131         while (sdb_llist_iter_has_next(iter)) {
1132                 sdb_plugin_log_cb callback;
1133                 int tmp;
1134
1135                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1136                 assert(obj);
1137
1138                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1139                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
1140                 if (tmp > ret)
1141                         ret = tmp;
1142
1143                 if (SDB_PLUGIN_CB(obj)->cb_ctx)
1144                         logged = 1;
1145                 /* else: this is an internally registered callback */
1146         }
1147         sdb_llist_iter_destroy(iter);
1148
1149         if (! logged)
1150                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
1151         return ret;
1152 } /* sdb_plugin_log */
1153
1154 int
1155 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
1156 {
1157         sdb_strbuf_t *buf;
1158         int ret;
1159
1160         if (! fmt)
1161                 return 0;
1162
1163         buf = sdb_strbuf_create(64);
1164         if (! buf) {
1165                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
1166                 ret += vfprintf(stderr, fmt, ap);
1167                 return ret;
1168         }
1169
1170         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1171                 sdb_strbuf_destroy(buf);
1172                 return -1;
1173         }
1174
1175         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1176         sdb_strbuf_destroy(buf);
1177         return ret;
1178 } /* sdb_plugin_vlogf */
1179
1180 int
1181 sdb_plugin_logf(int prio, const char *fmt, ...)
1182 {
1183         va_list ap;
1184         int ret;
1185
1186         if (! fmt)
1187                 return 0;
1188
1189         va_start(ap, fmt);
1190         ret = sdb_plugin_vlogf(prio, fmt, ap);
1191         va_end(ap);
1192         return ret;
1193 } /* sdb_plugin_logf */
1194
1195 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1196