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 *description;
  63         char *copyright;
  64         char *license;
  65
  66         int   version;
  67         int   plugin_version;
  68 };
  69 #define SDB_PLUGIN_INFO_INIT { \
  70         /* plugin_name */ NULL, /* filename */ NULL, /* desc */ NULL, \
  71         /* copyright */ NULL, /* license */ NULL, \
  72         /* version */ -1, /* plugin_version */ -1 }
  73 #define INFO_GET(i, attr) \
  74         ((i)->attr ? (i)->attr : #attr" not set")
  75
  76 typedef struct {
  77         sdb_object_t super;
  78         sdb_plugin_ctx_t public;
  79
  80         sdb_plugin_info_t info;
  81         lt_dlhandle handle;
  82
  83         /* The usage count differs from the object's ref count
  84          * in that it provides higher level information about how
  85          * the plugin is in use. */
  86         size_t use_cnt;
  87 } ctx_t;
  88 #define CTX_INIT { SDB_OBJECT_INIT, \
  89         SDB_PLUGIN_CTX_INIT, SDB_PLUGIN_INFO_INIT, NULL, 0 }
  90
  91 #define CTX(obj) ((ctx_t *)(obj))
  92
  93 typedef struct {
  94         sdb_object_t super;
  95         void *cb_callback;
  96         sdb_object_t *cb_user_data;
  97         ctx_t *cb_ctx;
  98 } sdb_plugin_cb_t;
  99 #define SDB_PLUGIN_CB_INIT { SDB_OBJECT_INIT, \
 100         /* callback = */ NULL, /* user_data = */ NULL, \
 101         SDB_PLUGIN_CTX_INIT }
 102
 103 typedef struct {
 104         sdb_plugin_cb_t super;
 105 #define ccb_callback super.cb_callback
 106 #define ccb_user_data super.cb_user_data
 107 #define ccb_ctx super.cb_ctx
 108         sdb_time_t ccb_interval;
 109         sdb_time_t ccb_next_update;
 110 } sdb_plugin_collector_cb_t;
 111
 112 #define SDB_PLUGIN_CB(obj) ((sdb_plugin_cb_t *)(obj))
 113 #define SDB_CONST_PLUGIN_CB(obj) ((const sdb_plugin_cb_t *)(obj))
 114 #define SDB_PLUGIN_CCB(obj) ((sdb_plugin_collector_cb_t *)(obj))
 115 #define SDB_CONST_PLUGIN_CCB(obj) ((const sdb_plugin_collector_cb_t *)(obj))
 116
 117 /*
 118  * private variables
 119  */
 120
 121 static sdb_plugin_ctx_t  plugin_default_ctx  = SDB_PLUGIN_CTX_INIT;
 122 static sdb_plugin_info_t plugin_default_info = SDB_PLUGIN_INFO_INIT;
 123
 124 static pthread_key_t     plugin_ctx_key;
 125 static _Bool             plugin_ctx_key_initialized = 0;
 126
 127 /* a list of the plugin contexts of all registered plugins */
 128 static sdb_llist_t      *all_plugins = NULL;
 129
 130 static sdb_llist_t      *config_list = NULL;
 131 static sdb_llist_t      *init_list = NULL;
 132 static sdb_llist_t      *collector_list = NULL;
 133 static sdb_llist_t      *cname_list = NULL;
 134 static sdb_llist_t      *shutdown_list = NULL;
 135 static sdb_llist_t      *log_list = NULL;
 136
 137 static struct {
 138         const char   *type;
 139         sdb_llist_t **list;
 140 } all_lists[] = {
 141         { "config",    &config_list },
 142         { "init",      &init_list },
 143         { "collector", &collector_list },
 144         { "cname",     &cname_list },
 145         { "shutdown",  &shutdown_list },
 146         { "log",       &log_list },
 147 };
 148
 149 /*
 150  * private helper functions
 151  */
 152
 153 static void
 154 plugin_info_clear(sdb_plugin_info_t *info)
 155 {
 156         sdb_plugin_info_t empty_info = SDB_PLUGIN_INFO_INIT;
 157         if (! info)
 158                 return;
 159
 160         if (info->plugin_name)
 161                 free(info->plugin_name);
 162         if (info->filename)
 163                 free(info->filename);
 164
 165         if (info->description)
 166                 free(info->description);
 167         if (info->copyright)
 168                 free(info->copyright);
 169         if (info->license)
 170                 free(info->license);
 171
 172         *info = empty_info;
 173 } /* plugin_info_clear */
 174
 175 static void
 176 ctx_key_init(void)
 177 {
 178         if (plugin_ctx_key_initialized)
 179                 return;
 180
 181         pthread_key_create(&plugin_ctx_key, /* destructor */ NULL);
 182         plugin_ctx_key_initialized = 1;
 183 } /* ctx_key_init */
 184
 185 static int
 186 plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
 187 {
 188         const sdb_plugin_collector_cb_t *ccb1
 189                 = (const sdb_plugin_collector_cb_t *)a;
 190         const sdb_plugin_collector_cb_t *ccb2
 191                 = (const sdb_plugin_collector_cb_t *)b;
 192
 193         assert(ccb1 && ccb2);
 194
 195         return (ccb1->ccb_next_update > ccb2->ccb_next_update)
 196                 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
 197                 ? -1 : 0;
 198 } /* plugin_cmp_next_update */
 199
 200 static int
 201 plugin_lookup_by_name(const sdb_object_t *obj, const void *id)
 202 {
 203         const sdb_plugin_cb_t *cb = SDB_CONST_PLUGIN_CB(obj);
 204         const char *name = id;
 205
 206         assert(cb && id);
 207
 208         /* when a plugin was registered from outside a plugin (e.g. the core),
 209          * we don't have a plugin context */
 210         if (! cb->cb_ctx)
 211                 return 1;
 212
 213         if (!strcasecmp(cb->cb_ctx->info.plugin_name, name))
 214                 return 0;
 215         return 1;
 216 } /* plugin_lookup_by_name */
 217
 218 /* since this function is called from sdb_plugin_reconfigure_finish()
 219  * when iterating through all_plugins, we may not do any additional
 220  * modifications to all_plugins except for the optional removal */
 221 static void
 222 plugin_unregister_by_name(const char *plugin_name)
 223 {
 224         sdb_object_t *obj;
 225         size_t i;
 226
 227         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 228                 const char  *type =  all_lists[i].type;
 229                 sdb_llist_t *list = *all_lists[i].list;
 230
 231                 while (1) {
 232                         sdb_plugin_cb_t *cb;
 233
 234                         cb = SDB_PLUGIN_CB(sdb_llist_remove(list,
 235                                                 plugin_lookup_by_name, plugin_name));
 236                         if (! cb)
 237                                 break;
 238
 239                         assert(cb->cb_ctx);
 240
 241                         sdb_log(SDB_LOG_INFO, "core: Unregistering "
 242                                         "%s callback '%s' (module %s)", type, cb->super.name,
 243                                         cb->cb_ctx->info.plugin_name);
 244                         sdb_object_deref(SDB_OBJ(cb));
 245                 }
 246         }
 247
 248         obj = sdb_llist_search_by_name(all_plugins, plugin_name);
 249         /* when called from sdb_plugin_reconfigure_finish, the object has already
 250          * been removed from the list */
 251         if (obj && (obj->ref_cnt <= 1)) {
 252                 sdb_llist_remove_by_name(all_plugins, plugin_name);
 253                 sdb_object_deref(obj);
 254         }
 255         /* else: other callbacks still reference it */
 256 } /* plugin_unregister_by_name */
 257
 258 static void
 259 plugin_unregister_all(void)
 260 {
 261         size_t i;
 262
 263         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 264                 const char  *type =  all_lists[i].type;
 265                 sdb_llist_t *list = *all_lists[i].list;
 266
 267                 size_t len = sdb_llist_len(list);
 268
 269                 if (! len)
 270                         continue;
 271
 272                 sdb_llist_clear(list);
 273                 sdb_log(SDB_LOG_INFO, "core: Unregistered %zu %s callback%s",
 274                                 len, type, len == 1 ? "" : "s");
 275         }
 276 } /* plugin_unregister_all */
 277
 278 /*
 279  * private types
 280  */
 281
 282 static int
 283 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 284 {
 285         ctx_t *ctx = CTX(obj);
 286
 287         assert(ctx);
 288
 289         ctx->public = plugin_default_ctx;
 290         ctx->info = plugin_default_info;
 291         ctx->handle = NULL;
 292         ctx->use_cnt = 1;
 293         return 0;
 294 } /* ctx_init */
 295
 296 static void
 297 ctx_destroy(sdb_object_t *obj)
 298 {
 299         ctx_t *ctx = CTX(obj);
 300
 301         if (ctx->handle) {
 302                 const char *err;
 303
 304                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s",
 305                                 ctx->info.plugin_name);
 306
 307                 lt_dlerror();
 308                 lt_dlclose(ctx->handle);
 309                 if ((err = lt_dlerror()))
 310                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload module %s: %s",
 311                                         ctx->info.plugin_name, err);
 312         }
 313
 314         plugin_info_clear(&ctx->info);
 315 } /* ctx_destroy */
 316
 317 static sdb_type_t ctx_type = {
 318         sizeof(ctx_t),
 319
 320         ctx_init,
 321         ctx_destroy
 322 };
 323
 324 static ctx_t *
 325 ctx_get(void)
 326 {
 327         if (! plugin_ctx_key_initialized)
 328                 ctx_key_init();
 329         return pthread_getspecific(plugin_ctx_key);
 330 } /* ctx_get */
 331
 332 static ctx_t *
 333 ctx_set(ctx_t *new)
 334 {
 335         ctx_t *old;
 336
 337         if (! plugin_ctx_key_initialized)
 338                 ctx_key_init();
 339
 340         old = pthread_getspecific(plugin_ctx_key);
 341         if (old)
 342                 sdb_object_deref(SDB_OBJ(old));
 343         if (new)
 344                 sdb_object_ref(SDB_OBJ(new));
 345         pthread_setspecific(plugin_ctx_key, new);
 346         return old;
 347 } /* ctx_set */
 348
 349 static ctx_t *
 350 ctx_create(const char *name)
 351 {
 352         ctx_t *ctx;
 353
 354         ctx = CTX(sdb_object_create(name, ctx_type));
 355         if (! ctx)
 356                 return NULL;
 357
 358         if (! plugin_ctx_key_initialized)
 359                 ctx_key_init();
 360         ctx_set(ctx);
 361         return ctx;
 362 } /* ctx_create */
 363
 364 static int
 365 plugin_cb_init(sdb_object_t *obj, va_list ap)
 366 {
 367         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 368         const char   *type = va_arg(ap, const char *);
 369         void     *callback = va_arg(ap, void *);
 370         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 371
 372         assert(list);
 373         assert(type);
 374         assert(obj);
 375
 376         if (sdb_llist_search_by_name(*list, obj->name)) {
 377                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 378                                 "has already been registered. Ignoring newly "
 379                                 "registered version.", type, obj->name);
 380                 return -1;
 381         }
 382
 383         /* cb_ctx may be NULL if the plugin was not registered by a plugin */
 384
 385         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 386         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 387         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 388
 389         sdb_object_ref(ud);
 390         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 391         return 0;
 392 } /* plugin_cb_init */
 393
 394 static void
 395 plugin_cb_destroy(sdb_object_t *obj)
 396 {
 397         assert(obj);
 398         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 399         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 400 } /* plugin_cb_destroy */
 401
 402 static sdb_type_t sdb_plugin_cb_type = {
 403         sizeof(sdb_plugin_cb_t),
 404
 405         plugin_cb_init,
 406         plugin_cb_destroy
 407 };
 408
 409 static sdb_type_t sdb_plugin_collector_cb_type = {
 410         sizeof(sdb_plugin_collector_cb_t),
 411
 412         plugin_cb_init,
 413         plugin_cb_destroy
 414 };
 415
 416 static int
 417 module_init(const char *name, lt_dlhandle lh, sdb_plugin_info_t *info)
 418 {
 419         int (*mod_init)(sdb_plugin_info_t *);
 420         int status;
 421
 422         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 423         if (! mod_init) {
 424                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 425                                 "could not find symbol 'sdb_module_init'", name);
 426                 return -1;
 427         }
 428
 429         status = mod_init(info);
 430         if (status) {
 431                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 432                                 "module '%s'", name);
 433                 plugin_unregister_by_name(name);
 434                 return -1;
 435         }
 436         return 0;
 437 } /* module_init */
 438
 439 static int
 440 module_load(const char *basedir, const char *name,
 441                 const sdb_plugin_ctx_t *plugin_ctx)
 442 {
 443         char  base_name[name ? strlen(name) + 1 : 1];
 444         const char *name_ptr;
 445         char *tmp;
 446
 447         char filename[1024];
 448         lt_dlhandle lh;
 449
 450         ctx_t *ctx;
 451
 452         int status;
 453
 454         assert(name);
 455
 456         base_name[0] = '\0';
 457         name_ptr = name;
 458
 459         while ((tmp = strstr(name_ptr, "::"))) {
 460                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 461                 strcat(base_name, "/");
 462                 name_ptr = tmp + strlen("::");
 463         }
 464         strcat(base_name, name_ptr);
 465
 466         if (! basedir)
 467                 basedir = PKGLIBDIR;
 468
 469         snprintf(filename, sizeof(filename), "%s/%s.so", basedir, 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                         ctx->info.plugin_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 char *
 538 plugin_get_name(const char *name, char *buf, size_t bufsize)
 539 {
 540         ctx_t *ctx = ctx_get();
 541
 542         if (ctx)
 543                 snprintf(buf, bufsize, "%s::%s", ctx->info.plugin_name, name);
 544         else
 545                 snprintf(buf, bufsize, "core::%s", name);
 546         return buf;
 547 } /* plugin_get_name */
 548
 549 static int
 550 plugin_add_callback(sdb_llist_t **list, const char *type,
 551                 const char *name, void *callback, sdb_object_t *user_data)
 552 {
 553         sdb_object_t *obj;
 554
 555         if ((! name) || (! callback))
 556                 return -1;
 557
 558         assert(list);
 559
 560         if (! *list)
 561                 *list = sdb_llist_create();
 562         if (! *list)
 563                 return -1;
 564
 565         obj = sdb_object_create(name, sdb_plugin_cb_type,
 566                         list, type, callback, user_data);
 567         if (! obj)
 568                 return -1;
 569
 570         if (sdb_llist_append(*list, obj)) {
 571                 sdb_object_deref(obj);
 572                 return -1;
 573         }
 574
 575         /* pass control to the list */
 576         sdb_object_deref(obj);
 577
 578         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 579                         type, name);
 580         return 0;
 581 } /* plugin_add_callback */
 582
 583 /*
 584  * public API
 585  */
 586
 587 int
 588 sdb_plugin_load(const char *basedir, const char *name,
 589                 const sdb_plugin_ctx_t *plugin_ctx)
 590 {
 591         ctx_t *ctx;
 592
 593         int status;
 594
 595         if ((! name) || (! *name))
 596                 return -1;
 597
 598         if (! all_plugins) {
 599                 if (! (all_plugins = sdb_llist_create())) {
 600                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 601                                         "internal error while creating linked list", name);
 602                         return -1;
 603                 }
 604         }
 605
 606         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 607         if (ctx) {
 608                 /* plugin already loaded */
 609                 if (! ctx->use_cnt) {
 610                         /* reloading plugin */
 611                         ctx_t *old_ctx = ctx_set(ctx);
 612
 613                         status = module_init(ctx->info.plugin_name, ctx->handle, NULL);
 614                         if (status)
 615                                 return status;
 616
 617                         sdb_log(SDB_LOG_INFO, "core: Successfully reloaded plugin "
 618                                         "'%s' (%s)", ctx->info.plugin_name,
 619                                         INFO_GET(&ctx->info, description));
 620                         ctx_set(old_ctx);
 621                 }
 622                 ++ctx->use_cnt;
 623                 return 0;
 624         }
 625
 626         return module_load(basedir, name, plugin_ctx);
 627 } /* sdb_plugin_load */
 628
 629 int
 630 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 631 {
 632         va_list ap;
 633
 634         if (! info)
 635                 return -1;
 636
 637         va_start(ap, type);
 638
 639         switch (type) {
 640                 case SDB_PLUGIN_INFO_DESC:
 641                         {
 642                                 char *desc = va_arg(ap, char *);
 643                                 if (desc) {
 644                                         if (info->description)
 645                                                 free(info->description);
 646                                         info->description = strdup(desc);
 647                                 }
 648                         }
 649                         break;
 650                 case SDB_PLUGIN_INFO_COPYRIGHT:
 651                         {
 652                                 char *copyright = va_arg(ap, char *);
 653                                 if (copyright)
 654                                         info->copyright = strdup(copyright);
 655                         }
 656                         break;
 657                 case SDB_PLUGIN_INFO_LICENSE:
 658                         {
 659                                 char *license = va_arg(ap, char *);
 660                                 if (license) {
 661                                         if (info->license)
 662                                                 free(info->license);
 663                                         info->license = strdup(license);
 664                                 }
 665                         }
 666                         break;
 667                 case SDB_PLUGIN_INFO_VERSION:
 668                         {
 669                                 int version = va_arg(ap, int);
 670                                 info->version = version;
 671                         }
 672                         break;
 673                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 674                         {
 675                                 int version = va_arg(ap, int);
 676                                 info->plugin_version = version;
 677                         }
 678                         break;
 679                 default:
 680                         va_end(ap);
 681                         return -1;
 682         }
 683
 684         va_end(ap);
 685         return 0;
 686 } /* sdb_plugin_set_info */
 687
 688 int
 689 sdb_plugin_register_config(sdb_plugin_config_cb callback)
 690 {
 691         ctx_t *ctx = ctx_get();
 692
 693         if (! ctx) {
 694                 sdb_log(SDB_LOG_ERR, "core: Invalid attempt to register a "
 695                                 "config callback from outside a plugin");
 696                 return -1;
 697         }
 698         return plugin_add_callback(&config_list, "init", ctx->info.plugin_name,
 699                         (void *)callback, NULL);
 700 } /* sdb_plugin_register_config */
 701
 702 int
 703 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 704                 sdb_object_t *user_data)
 705 {
 706         char cb_name[1024];
 707         return plugin_add_callback(&init_list, "init",
 708                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 709                         (void *)callback, user_data);
 710 } /* sdb_plugin_register_init */
 711
 712 int
 713 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 714                 sdb_object_t *user_data)
 715 {
 716         char cb_name[1024];
 717         return plugin_add_callback(&shutdown_list, "shutdown",
 718                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 719                         (void *)callback, user_data);
 720 } /* sdb_plugin_register_shutdown */
 721
 722 int
 723 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 724                 sdb_object_t *user_data)
 725 {
 726         char cb_name[1024];
 727         return plugin_add_callback(&log_list, "log",
 728                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 729                         callback, user_data);
 730 } /* sdb_plugin_register_log */
 731
 732 int
 733 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 734                 sdb_object_t *user_data)
 735 {
 736         char cb_name[1024];
 737         return plugin_add_callback(&cname_list, "cname",
 738                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 739                         callback, user_data);
 740 } /* sdb_plugin_register_cname */
 741
 742 int
 743 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 744                 const sdb_time_t *interval, sdb_object_t *user_data)
 745 {
 746         char cb_name[1024];
 747         sdb_object_t *obj;
 748
 749         if ((! name) || (! callback))
 750                 return -1;
 751
 752         if (! collector_list)
 753                 collector_list = sdb_llist_create();
 754         if (! collector_list)
 755                 return -1;
 756
 757         plugin_get_name(name, cb_name, sizeof(cb_name));
 758
 759         obj = sdb_object_create(cb_name, sdb_plugin_collector_cb_type,
 760                         &collector_list, "collector", callback, user_data);
 761         if (! obj)
 762                 return -1;
 763
 764         if (interval)
 765                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 766         else {
 767                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 768
 769                 if (tmp > 0)
 770                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 771                 else
 772                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 773         }
 774
 775         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 776                 char errbuf[1024];
 777                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 778                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 779                 sdb_object_deref(obj);
 780                 return -1;
 781         }
 782
 783         if (sdb_llist_insert_sorted(collector_list, obj,
 784                                 plugin_cmp_next_update)) {
 785                 sdb_object_deref(obj);
 786                 return -1;
 787         }
 788
 789         /* pass control to the list */
 790         sdb_object_deref(obj);
 791
 792         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 793                         "(interval = %.3fs).", cb_name,
 794                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 795         return 0;
 796 } /* sdb_plugin_register_collector */
 797
 798 sdb_plugin_ctx_t
 799 sdb_plugin_get_ctx(void)
 800 {
 801         ctx_t *c;
 802
 803         c = ctx_get();
 804         if (! c) {
 805                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 806                                 "context outside a plugin");
 807                 return plugin_default_ctx;
 808         }
 809         return c->public;
 810 } /* sdb_plugin_get_ctx */
 811
 812 int
 813 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 814 {
 815         ctx_t *c;
 816
 817         c = ctx_get();
 818         if (! c) {
 819                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 820                                 "context outside a plugin");
 821                 return -1;
 822         }
 823
 824         if (old)
 825                 *old = c->public;
 826         c->public = ctx;
 827         return 0;
 828 } /* sdb_plugin_set_ctx */
 829
 830 int
 831 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 832 {
 833         sdb_plugin_cb_t *plugin;
 834         sdb_plugin_config_cb callback;
 835
 836         ctx_t *old_ctx;
 837
 838         int status;
 839
 840         if ((! name) || (! ci))
 841                 return -1;
 842
 843         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 844         if (! plugin) {
 845                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 846                 if (! ctx)
 847                         sdb_log(SDB_LOG_ERR, "core: Cannot configure unknown "
 848                                         "plugin '%s'. Missing 'LoadPlugin \"%s\"'?",
 849                                         name, name);
 850                 else
 851                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 852                                         "a config callback.", name);
 853                 errno = ENOENT;
 854                 return -1;
 855         }
 856
 857         old_ctx = ctx_set(plugin->cb_ctx);
 858         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 859         status = callback(ci);
 860         ctx_set(old_ctx);
 861         return status;
 862 } /* sdb_plugin_configure */
 863
 864 int
 865 sdb_plugin_reconfigure_init(void)
 866 {
 867         sdb_llist_iter_t *iter;
 868
 869         iter = sdb_llist_get_iter(config_list);
 870         if (config_list && (! iter))
 871                 return -1;
 872
 873         /* deconfigure all plugins */
 874         while (sdb_llist_iter_has_next(iter)) {
 875                 sdb_plugin_cb_t *plugin;
 876                 sdb_plugin_config_cb callback;
 877                 ctx_t *old_ctx;
 878
 879                 plugin = SDB_PLUGIN_CB(sdb_llist_iter_get_next(iter));
 880                 old_ctx = ctx_set(plugin->cb_ctx);
 881                 callback = (sdb_plugin_config_cb)plugin->cb_callback;
 882                 callback(NULL);
 883                 ctx_set(old_ctx);
 884         }
 885         sdb_llist_iter_destroy(iter);
 886
 887         iter = sdb_llist_get_iter(all_plugins);
 888         if (all_plugins && (! iter))
 889                 return -1;
 890
 891         /* record all plugins as being unused */
 892         while (sdb_llist_iter_has_next(iter))
 893                 CTX(sdb_llist_iter_get_next(iter))->use_cnt = 0;
 894         sdb_llist_iter_destroy(iter);
 895
 896         plugin_unregister_all();
 897         return 0;
 898 } /* sdb_plugin_reconfigure_init */
 899
 900 int
 901 sdb_plugin_reconfigure_finish(void)
 902 {
 903         sdb_llist_iter_t *iter;
 904
 905         iter = sdb_llist_get_iter(all_plugins);
 906         if (all_plugins && (! iter))
 907                 return -1;
 908
 909         while (sdb_llist_iter_has_next(iter)) {
 910                 ctx_t *ctx = CTX(sdb_llist_iter_get_next(iter));
 911                 if (ctx->use_cnt)
 912                         continue;
 913
 914                 sdb_log(SDB_LOG_INFO, "core: Module %s no longer in use",
 915                                 ctx->info.plugin_name);
 916                 sdb_llist_iter_remove_current(iter);
 917                 plugin_unregister_by_name(ctx->info.plugin_name);
 918                 sdb_object_deref(SDB_OBJ(ctx));
 919         }
 920         sdb_llist_iter_destroy(iter);
 921         return 0;
 922 } /* sdb_plugin_reconfigure_finish */
 923
 924 int
 925 sdb_plugin_init_all(void)
 926 {
 927         sdb_llist_iter_t *iter;
 928         int ret = 0;
 929
 930         iter = sdb_llist_get_iter(init_list);
 931         while (sdb_llist_iter_has_next(iter)) {
 932                 sdb_plugin_cb_t *cb;
 933                 sdb_plugin_init_cb callback;
 934                 ctx_t *old_ctx;
 935
 936                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 937                 assert(obj);
 938                 cb = SDB_PLUGIN_CB(obj);
 939
 940                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 941
 942                 old_ctx = ctx_set(cb->cb_ctx);
 943                 if (callback(cb->cb_user_data)) {
 944                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 945                                         "'%s'. Unregistering all callbacks.", obj->name);
 946                         ctx_set(old_ctx);
 947                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 948                         ++ret;
 949                 }
 950                 else
 951                         ctx_set(old_ctx);
 952         }
 953         sdb_llist_iter_destroy(iter);
 954         return ret;
 955 } /* sdb_plugin_init_all */
 956
 957 int
 958 sdb_plugin_shutdown_all(void)
 959 {
 960         sdb_llist_iter_t *iter;
 961         int ret = 0;
 962
 963         iter = sdb_llist_get_iter(shutdown_list);
 964         while (sdb_llist_iter_has_next(iter)) {
 965                 sdb_plugin_cb_t *cb;
 966                 sdb_plugin_shutdown_cb callback;
 967                 ctx_t *old_ctx;
 968
 969                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 970                 assert(obj);
 971                 cb = SDB_PLUGIN_CB(obj);
 972
 973                 callback = (sdb_plugin_shutdown_cb)cb->cb_callback;
 974
 975                 old_ctx = ctx_set(cb->cb_ctx);
 976                 if (callback(cb->cb_user_data)) {
 977                         sdb_log(SDB_LOG_ERR, "core: Failed to shutdown plugin '%s'.",
 978                                         obj->name);
 979                         ++ret;
 980                 }
 981                 ctx_set(old_ctx);
 982         }
 983         sdb_llist_iter_destroy(iter);
 984         return ret;
 985 } /* sdb_plugin_shutdown_all */
 986
 987 int
 988 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 989 {
 990         if (! collector_list) {
 991                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 992                                 "Quiting main loop.");
 993                 return -1;
 994         }
 995
 996         if (! loop)
 997                 return -1;
 998
 999         while (loop->do_loop) {
1000                 sdb_plugin_collector_cb callback;
1001                 ctx_t *old_ctx;
1002
1003                 sdb_time_t interval, now;
1004
1005                 sdb_object_t *obj = sdb_llist_shift(collector_list);
1006                 if (! obj)
1007                         return -1;
1008
1009                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
1010
1011                 if (! (now = sdb_gettime())) {
1012                         char errbuf[1024];
1013                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1014                                         "time in collector main loop: %s",
1015                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1016                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1017                 }
1018
1019                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1020                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
1021
1022                         errno = 0;
1023                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
1024                                 if (errno != EINTR) {
1025                                         char errbuf[1024];
1026                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
1027                                                         "in collector main loop: %s",
1028                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1029                                         sdb_llist_insert_sorted(collector_list, obj,
1030                                                         plugin_cmp_next_update);
1031                                         sdb_object_deref(obj);
1032                                         return -1;
1033                                 }
1034                                 errno = 0;
1035                         }
1036
1037                         if (! loop->do_loop) {
1038                                 /* put back; don't worry about errors */
1039                                 sdb_llist_insert_sorted(collector_list, obj,
1040                                                 plugin_cmp_next_update);
1041                                 sdb_object_deref(obj);
1042                                 return 0;
1043                         }
1044                 }
1045
1046                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
1047                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
1048                         /* XXX */
1049                 }
1050                 ctx_set(old_ctx);
1051
1052                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
1053                 if (! interval)
1054                         interval = loop->default_interval;
1055                 if (! interval) {
1056                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
1057                                         "for plugin '%s'; skipping any further "
1058                                         "iterations.", obj->name);
1059                         sdb_object_deref(obj);
1060                         continue;
1061                 }
1062
1063                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
1064
1065                 if (! (now = sdb_gettime())) {
1066                         char errbuf[1024];
1067                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1068                                         "time in collector main loop: %s",
1069                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1070                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1071                 }
1072
1073                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1074                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
1075                                         "long; skipping iterations to keep up.",
1076                                         obj->name);
1077                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
1078                 }
1079
1080                 if (sdb_llist_insert_sorted(collector_list, obj,
1081                                         plugin_cmp_next_update)) {
1082                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
1083                                         "plugin '%s' into collector list. Unable to further "
1084                                         "use the plugin.",
1085                                         obj->name);
1086                         sdb_object_deref(obj);
1087                         return -1;
1088                 }
1089
1090                 /* pass control back to the list */
1091                 sdb_object_deref(obj);
1092         }
1093         return 0;
1094 } /* sdb_plugin_read_loop */
1095
1096 char *
1097 sdb_plugin_cname(char *hostname)
1098 {
1099         sdb_llist_iter_t *iter;
1100
1101         if (! hostname)
1102                 return NULL;
1103
1104         if (! cname_list)
1105                 return hostname;
1106
1107         iter = sdb_llist_get_iter(cname_list);
1108         while (sdb_llist_iter_has_next(iter)) {
1109                 sdb_plugin_cname_cb callback;
1110                 char *cname;
1111
1112                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1113                 assert(obj);
1114
1115                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1116                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
1117                 if (cname) {
1118                         free(hostname);
1119                         hostname = cname;
1120                 }
1121                 /* else: don't change hostname */
1122         }
1123         sdb_llist_iter_destroy(iter);
1124         return hostname;
1125 } /* sdb_plugin_cname */
1126
1127 int
1128 sdb_plugin_log(int prio, const char *msg)
1129 {
1130         sdb_llist_iter_t *iter;
1131         int ret = -1;
1132
1133         _Bool logged = 0;
1134
1135         if (! msg)
1136                 return 0;
1137
1138         iter = sdb_llist_get_iter(log_list);
1139         while (sdb_llist_iter_has_next(iter)) {
1140                 sdb_plugin_log_cb callback;
1141                 int tmp;
1142
1143                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1144                 assert(obj);
1145
1146                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1147                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
1148                 if (tmp > ret)
1149                         ret = tmp;
1150
1151                 if (SDB_PLUGIN_CB(obj)->cb_ctx)
1152                         logged = 1;
1153                 /* else: this is an internally registered callback */
1154         }
1155         sdb_llist_iter_destroy(iter);
1156
1157         if (! logged)
1158                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
1159         return ret;
1160 } /* sdb_plugin_log */
1161
1162 int
1163 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
1164 {
1165         sdb_strbuf_t *buf;
1166         int ret;
1167
1168         if (! fmt)
1169                 return 0;
1170
1171         buf = sdb_strbuf_create(64);
1172         if (! buf) {
1173                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
1174                 ret += vfprintf(stderr, fmt, ap);
1175                 return ret;
1176         }
1177
1178         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1179                 sdb_strbuf_destroy(buf);
1180                 return -1;
1181         }
1182
1183         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1184         sdb_strbuf_destroy(buf);
1185         return ret;
1186 } /* sdb_plugin_vlogf */
1187
1188 int
1189 sdb_plugin_logf(int prio, const char *fmt, ...)
1190 {
1191         va_list ap;
1192         int ret;
1193
1194         if (! fmt)
1195                 return 0;
1196
1197         va_start(ap, fmt);
1198         ret = sdb_plugin_vlogf(prio, fmt, ap);
1199         va_end(ap);
1200         return ret;
1201 } /* sdb_plugin_logf */
1202
1203 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1204