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 *name, const sdb_plugin_ctx_t *plugin_ctx)
 446 {
 447         char  base_name[name ? strlen(name) + 1 : 1];
 448         const char *name_ptr;
 449         char *tmp;
 450
 451         char filename[1024];
 452         lt_dlhandle lh;
 453
 454         ctx_t *ctx;
 455
 456         int status;
 457
 458         base_name[0] = '\0';
 459         name_ptr = name;
 460
 461         while ((tmp = strstr(name_ptr, "::"))) {
 462                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 463                 strcat(base_name, "/");
 464                 name_ptr = tmp + strlen("::");
 465         }
 466         strcat(base_name, name_ptr);
 467
 468         snprintf(filename, sizeof(filename), "%s/%s.so",
 469                         PKGLIBDIR, base_name);
 470         filename[sizeof(filename) - 1] = '\0';
 471
 472         if (access(filename, R_OK)) {
 473                 char errbuf[1024];
 474                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 475                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 476                 return -1;
 477         }
 478
 479         lt_dlinit();
 480         lt_dlerror();
 481
 482         lh = lt_dlopen(filename);
 483         if (! lh) {
 484                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 485                                 "The most common cause for this problem are missing "
 486                                 "dependencies.\n", name, lt_dlerror());
 487                 return -1;
 488         }
 489
 490         if (ctx_get())
 491                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 492
 493         ctx = ctx_create(name);
 494         if (! ctx) {
 495                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 496                 return -1;
 497         }
 498
 499         ctx->info.plugin_name = strdup(name);
 500         ctx->info.filename = strdup(filename);
 501         ctx->handle = lh;
 502
 503         if (plugin_ctx)
 504                 ctx->public = *plugin_ctx;
 505
 506         if ((status = module_init(name, lh, &ctx->info))) {
 507                 sdb_object_deref(SDB_OBJ(ctx));
 508                 return status;
 509         }
 510
 511         /* compare minor version */
 512         if ((ctx->info.version < 0)
 513                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 514                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 515                                 "plugin '%s' (%i.%i.%i) does not match our version "
 516                                 "(%i.%i.%i); this might cause problems",
 517                                 name, SDB_VERSION_DECODE(ctx->info.version),
 518                                 SDB_VERSION_DECODE(SDB_VERSION));
 519
 520         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 521
 522         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 523                         "plugin '%s' v%i (%s)\n\t%s\n\tLicense: %s",
 524                         INFO_GET(&ctx->info, name), ctx->info.plugin_version,
 525                         INFO_GET(&ctx->info, description),
 526                         INFO_GET(&ctx->info, copyright),
 527                         INFO_GET(&ctx->info, license));
 528
 529         /* any registered callbacks took ownership of the context */
 530         sdb_object_deref(SDB_OBJ(ctx));
 531
 532         /* reset */
 533         ctx_set(NULL);
 534         return 0;
 535 } /* module_load */
 536
 537 static int
 538 plugin_add_callback(sdb_llist_t **list, const char *type,
 539                 const char *name, void *callback, sdb_object_t *user_data)
 540 {
 541         sdb_object_t *obj;
 542
 543         if ((! name) || (! callback))
 544                 return -1;
 545
 546         assert(list);
 547
 548         if (! *list)
 549                 *list = sdb_llist_create();
 550         if (! *list)
 551                 return -1;
 552
 553         obj = sdb_object_create(name, sdb_plugin_cb_type,
 554                         list, type, callback, user_data);
 555         if (! obj)
 556                 return -1;
 557
 558         if (sdb_llist_append(*list, obj)) {
 559                 sdb_object_deref(obj);
 560                 return -1;
 561         }
 562
 563         /* pass control to the list */
 564         sdb_object_deref(obj);
 565
 566         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 567                         type, name);
 568         return 0;
 569 } /* plugin_add_callback */
 570
 571 /*
 572  * public API
 573  */
 574
 575 int
 576 sdb_plugin_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 577 {
 578         ctx_t *ctx;
 579
 580         int status;
 581
 582         if ((! name) || (! *name))
 583                 return -1;
 584
 585         if (! all_plugins) {
 586                 if (! (all_plugins = sdb_llist_create())) {
 587                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 588                                         "internal error while creating linked list", name);
 589                         return -1;
 590                 }
 591         }
 592
 593         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 594         if (ctx) {
 595                 /* plugin already loaded */
 596                 if (! ctx->use_cnt) {
 597                         /* reloading plugin */
 598                         ctx_t *old_ctx = ctx_set(ctx);
 599
 600                         status = module_init(ctx->info.plugin_name, ctx->handle, NULL);
 601                         if (status)
 602                                 return status;
 603
 604                         sdb_log(SDB_LOG_INFO, "core: Successfully reloaded plugin "
 605                                         "'%s' (%s)", INFO_GET(&ctx->info, name),
 606                                         INFO_GET(&ctx->info, description));
 607                         ctx_set(old_ctx);
 608                 }
 609                 ++ctx->use_cnt;
 610                 return 0;
 611         }
 612
 613         return module_load(name, plugin_ctx);
 614 } /* sdb_plugin_load */
 615
 616 int
 617 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 618 {
 619         va_list ap;
 620
 621         if (! info)
 622                 return -1;
 623
 624         va_start(ap, type);
 625
 626         switch (type) {
 627                 case SDB_PLUGIN_INFO_NAME:
 628                         {
 629                                 char *name = va_arg(ap, char *);
 630                                 if (name) {
 631                                         if (info->name)
 632                                                 free(info->name);
 633                                         info->name = strdup(name);
 634                                 }
 635                         }
 636                         break;
 637                 case SDB_PLUGIN_INFO_DESC:
 638                         {
 639                                 char *desc = va_arg(ap, char *);
 640                                 if (desc) {
 641                                         if (info->description)
 642                                                 free(info->description);
 643                                         info->description = strdup(desc);
 644                                 }
 645                         }
 646                         break;
 647                 case SDB_PLUGIN_INFO_COPYRIGHT:
 648                         {
 649                                 char *copyright = va_arg(ap, char *);
 650                                 if (copyright)
 651                                         info->copyright = strdup(copyright);
 652                         }
 653                         break;
 654                 case SDB_PLUGIN_INFO_LICENSE:
 655                         {
 656                                 char *license = va_arg(ap, char *);
 657                                 if (license) {
 658                                         if (info->license)
 659                                                 free(info->license);
 660                                         info->license = strdup(license);
 661                                 }
 662                         }
 663                         break;
 664                 case SDB_PLUGIN_INFO_VERSION:
 665                         {
 666                                 int version = va_arg(ap, int);
 667                                 info->version = version;
 668                         }
 669                         break;
 670                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 671                         {
 672                                 int version = va_arg(ap, int);
 673                                 info->plugin_version = version;
 674                         }
 675                         break;
 676                 default:
 677                         va_end(ap);
 678                         return -1;
 679         }
 680
 681         va_end(ap);
 682         return 0;
 683 } /* sdb_plugin_set_info */
 684
 685 int
 686 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
 687 {
 688         return plugin_add_callback(&config_list, "init", name,
 689                         (void *)callback, NULL);
 690 } /* sdb_plugin_register_config */
 691
 692 int
 693 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 694                 sdb_object_t *user_data)
 695 {
 696         return plugin_add_callback(&init_list, "init", name,
 697                         (void *)callback, user_data);
 698 } /* sdb_plugin_register_init */
 699
 700 int
 701 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 702                 sdb_object_t *user_data)
 703 {
 704         return plugin_add_callback(&shutdown_list, "shutdown", name,
 705                         (void *)callback, user_data);
 706 } /* sdb_plugin_register_shutdown */
 707
 708 int
 709 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 710                 sdb_object_t *user_data)
 711 {
 712         return plugin_add_callback(&log_list, "log", name, (void *)callback,
 713                         user_data);
 714 } /* sdb_plugin_register_log */
 715
 716 int
 717 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 718                 sdb_object_t *user_data)
 719 {
 720         return plugin_add_callback(&cname_list, "cname", name, (void *)callback,
 721                         user_data);
 722 } /* sdb_plugin_register_cname */
 723
 724 int
 725 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 726                 const sdb_time_t *interval, sdb_object_t *user_data)
 727 {
 728         sdb_object_t *obj;
 729
 730         if ((! name) || (! callback))
 731                 return -1;
 732
 733         if (! collector_list)
 734                 collector_list = sdb_llist_create();
 735         if (! collector_list)
 736                 return -1;
 737
 738         obj = sdb_object_create(name, sdb_plugin_collector_cb_type,
 739                         &collector_list, "collector", callback, user_data);
 740         if (! obj)
 741                 return -1;
 742
 743         if (interval)
 744                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 745         else {
 746                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 747
 748                 if (tmp > 0)
 749                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 750                 else
 751                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 752         }
 753
 754         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 755                 char errbuf[1024];
 756                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 757                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 758                 sdb_object_deref(obj);
 759                 return -1;
 760         }
 761
 762         if (sdb_llist_insert_sorted(collector_list, obj,
 763                                 plugin_cmp_next_update)) {
 764                 sdb_object_deref(obj);
 765                 return -1;
 766         }
 767
 768         /* pass control to the list */
 769         sdb_object_deref(obj);
 770
 771         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 772                         "(interval = %.3fs).", name,
 773                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 774         return 0;
 775 } /* sdb_plugin_register_collector */
 776
 777 sdb_plugin_ctx_t
 778 sdb_plugin_get_ctx(void)
 779 {
 780         ctx_t *c;
 781
 782         c = ctx_get();
 783         if (! c) {
 784                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 785                                 "context outside a plugin");
 786                 return plugin_default_ctx;
 787         }
 788         return c->public;
 789 } /* sdb_plugin_get_ctx */
 790
 791 int
 792 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 793 {
 794         ctx_t *c;
 795
 796         c = ctx_get();
 797         if (! c) {
 798                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 799                                 "context outside a plugin");
 800                 return -1;
 801         }
 802
 803         if (old)
 804                 *old = c->public;
 805         c->public = ctx;
 806         return 0;
 807 } /* sdb_plugin_set_ctx */
 808
 809 int
 810 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 811 {
 812         sdb_plugin_cb_t *plugin;
 813         sdb_plugin_config_cb callback;
 814
 815         ctx_t *old_ctx;
 816
 817         int status;
 818
 819         if ((! name) || (! ci))
 820                 return -1;
 821
 822         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 823         if (! plugin) {
 824                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 825                 if (! ctx)
 826                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' not loaded.", name);
 827                 else
 828                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 829                                         "a config callback.", name);
 830                 errno = ENOENT;
 831                 return -1;
 832         }
 833
 834         old_ctx = ctx_set(plugin->cb_ctx);
 835         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 836         status = callback(ci);
 837         ctx_set(old_ctx);
 838         return status;
 839 } /* sdb_plugin_configure */
 840
 841 int
 842 sdb_plugin_reconfigure_init(void)
 843 {
 844         sdb_llist_iter_t *iter;
 845
 846         iter = sdb_llist_get_iter(config_list);
 847         if (config_list && (! iter))
 848                 return -1;
 849
 850         /* deconfigure all plugins */
 851         while (sdb_llist_iter_has_next(iter)) {
 852                 sdb_plugin_cb_t *plugin;
 853                 sdb_plugin_config_cb callback;
 854                 ctx_t *old_ctx;
 855
 856                 plugin = SDB_PLUGIN_CB(sdb_llist_iter_get_next(iter));
 857                 old_ctx = ctx_set(plugin->cb_ctx);
 858                 callback = (sdb_plugin_config_cb)plugin->cb_callback;
 859                 callback(NULL);
 860                 ctx_set(old_ctx);
 861         }
 862         sdb_llist_iter_destroy(iter);
 863
 864         iter = sdb_llist_get_iter(all_plugins);
 865         if (all_plugins && (! iter))
 866                 return -1;
 867
 868         /* record all plugins as being unused */
 869         while (sdb_llist_iter_has_next(iter))
 870                 CTX(sdb_llist_iter_get_next(iter))->use_cnt = 0;
 871         sdb_llist_iter_destroy(iter);
 872
 873         plugin_unregister_all();
 874         return 0;
 875 } /* sdb_plugin_reconfigure_init */
 876
 877 int
 878 sdb_plugin_reconfigure_finish(void)
 879 {
 880         sdb_llist_iter_t *iter;
 881
 882         iter = sdb_llist_get_iter(all_plugins);
 883         if (all_plugins && (! iter))
 884                 return -1;
 885
 886         while (sdb_llist_iter_has_next(iter)) {
 887                 ctx_t *ctx = CTX(sdb_llist_iter_get_next(iter));
 888                 if (ctx->use_cnt)
 889                         continue;
 890
 891                 sdb_log(SDB_LOG_INFO, "core: Module %s no longer in use",
 892                                 ctx->info.plugin_name);
 893                 sdb_llist_iter_remove_current(iter);
 894                 plugin_unregister_by_name(ctx->info.plugin_name);
 895                 sdb_object_deref(SDB_OBJ(ctx));
 896         }
 897         sdb_llist_iter_destroy(iter);
 898         return 0;
 899 } /* sdb_plugin_reconfigure_finish */
 900
 901 int
 902 sdb_plugin_init_all(void)
 903 {
 904         sdb_llist_iter_t *iter;
 905         int ret = 0;
 906
 907         iter = sdb_llist_get_iter(init_list);
 908         while (sdb_llist_iter_has_next(iter)) {
 909                 sdb_plugin_cb_t *cb;
 910                 sdb_plugin_init_cb callback;
 911                 ctx_t *old_ctx;
 912
 913                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 914                 assert(obj);
 915                 cb = SDB_PLUGIN_CB(obj);
 916
 917                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 918
 919                 old_ctx = ctx_set(cb->cb_ctx);
 920                 if (callback(cb->cb_user_data)) {
 921                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 922                                         "'%s'. Unregistering all callbacks.", obj->name);
 923                         ctx_set(old_ctx);
 924                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 925                         ++ret;
 926                 }
 927                 else
 928                         ctx_set(old_ctx);
 929         }
 930         sdb_llist_iter_destroy(iter);
 931         return ret;
 932 } /* sdb_plugin_init_all */
 933
 934 int
 935 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 936 {
 937         if (! collector_list) {
 938                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 939                                 "Quiting main loop.");
 940                 return -1;
 941         }
 942
 943         if (! loop)
 944                 return -1;
 945
 946         while (loop->do_loop) {
 947                 sdb_plugin_collector_cb callback;
 948                 ctx_t *old_ctx;
 949
 950                 sdb_time_t interval, now;
 951
 952                 sdb_object_t *obj = sdb_llist_shift(collector_list);
 953                 if (! obj)
 954                         return -1;
 955
 956                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
 957
 958                 if (! (now = sdb_gettime())) {
 959                         char errbuf[1024];
 960                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 961                                         "time in collector main loop: %s",
 962                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 963                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 964                 }
 965
 966                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 967                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
 968
 969                         errno = 0;
 970                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
 971                                 if (errno != EINTR) {
 972                                         char errbuf[1024];
 973                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
 974                                                         "in collector main loop: %s",
 975                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 976                                         return -1;
 977                                 }
 978                                 errno = 0;
 979                         }
 980
 981                         if (! loop->do_loop)
 982                                 return 0;
 983                 }
 984
 985                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
 986                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
 987                         /* XXX */
 988                 }
 989                 ctx_set(old_ctx);
 990
 991                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
 992                 if (! interval)
 993                         interval = loop->default_interval;
 994                 if (! interval) {
 995                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
 996                                         "for plugin '%s'; skipping any further "
 997                                         "iterations.", obj->name);
 998                         sdb_object_deref(obj);
 999                         continue;
1000                 }
1001
1002                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
1003
1004                 if (! (now = sdb_gettime())) {
1005                         char errbuf[1024];
1006                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1007                                         "time in collector main loop: %s",
1008                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1009                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1010                 }
1011
1012                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1013                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
1014                                         "long; skipping iterations to keep up.",
1015                                         obj->name);
1016                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
1017                 }
1018
1019                 if (sdb_llist_insert_sorted(collector_list, obj,
1020                                         plugin_cmp_next_update)) {
1021                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
1022                                         "plugin '%s' into collector list. Unable to further "
1023                                         "use the plugin.",
1024                                         obj->name);
1025                         sdb_object_deref(obj);
1026                         return -1;
1027                 }
1028
1029                 /* pass control back to the list */
1030                 sdb_object_deref(obj);
1031         }
1032         return 0;
1033 } /* sdb_plugin_read_loop */
1034
1035 char *
1036 sdb_plugin_cname(char *hostname)
1037 {
1038         sdb_llist_iter_t *iter;
1039
1040         if (! hostname)
1041                 return NULL;
1042
1043         if (! cname_list)
1044                 return hostname;
1045
1046         iter = sdb_llist_get_iter(cname_list);
1047         while (sdb_llist_iter_has_next(iter)) {
1048                 sdb_plugin_cname_cb callback;
1049                 char *cname;
1050
1051                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1052                 assert(obj);
1053
1054                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1055                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
1056                 if (cname) {
1057                         free(hostname);
1058                         hostname = cname;
1059                 }
1060                 /* else: don't change hostname */
1061         }
1062         sdb_llist_iter_destroy(iter);
1063         return hostname;
1064 } /* sdb_plugin_cname */
1065
1066 int
1067 sdb_plugin_log(int prio, const char *msg)
1068 {
1069         sdb_llist_iter_t *iter;
1070         int ret = -1;
1071
1072         if (! msg)
1073                 return 0;
1074
1075         if (! sdb_llist_len(log_list))
1076                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
1077
1078         iter = sdb_llist_get_iter(log_list);
1079         while (sdb_llist_iter_has_next(iter)) {
1080                 sdb_plugin_log_cb callback;
1081                 int tmp;
1082
1083                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1084                 assert(obj);
1085
1086                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1087                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
1088                 if (tmp > ret)
1089                         ret = tmp;
1090         }
1091         sdb_llist_iter_destroy(iter);
1092         return ret;
1093 } /* sdb_plugin_log */
1094
1095 int
1096 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
1097 {
1098         sdb_strbuf_t *buf;
1099         int ret;
1100
1101         if (! fmt)
1102                 return 0;
1103
1104         buf = sdb_strbuf_create(64);
1105         if (! buf) {
1106                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
1107                 ret += vfprintf(stderr, fmt, ap);
1108                 return ret;
1109         }
1110
1111         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1112                 sdb_strbuf_destroy(buf);
1113                 return -1;
1114         }
1115
1116         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1117         sdb_strbuf_destroy(buf);
1118         return ret;
1119 } /* sdb_plugin_vlogf */
1120
1121 int
1122 sdb_plugin_logf(int prio, const char *fmt, ...)
1123 {
1124         va_list ap;
1125         int ret;
1126
1127         if (! fmt)
1128                 return 0;
1129
1130         va_start(ap, fmt);
1131         ret = sdb_plugin_vlogf(prio, fmt, ap);
1132         va_end(ap);
1133         return ret;
1134 } /* sdb_plugin_logf */
1135
1136 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1137