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)", ctx->info.plugin_name,
 524                         ctx->info.plugin_version,
 525                         INFO_GET(&ctx->info, description));
 526         sdb_log(SDB_LOG_INFO, "core: Plugin %s: %s, License: %s",
 527                         ctx->info.plugin_name,
 528                         INFO_GET(&ctx->info, copyright),
 529                         INFO_GET(&ctx->info, license));
 530
 531         /* any registered callbacks took ownership of the context */
 532         sdb_object_deref(SDB_OBJ(ctx));
 533
 534         /* reset */
 535         ctx_set(NULL);
 536         return 0;
 537 } /* module_load */
 538
 539 static char *
 540 plugin_get_name(const char *name, char *buf, size_t bufsize)
 541 {
 542         ctx_t *ctx = ctx_get();
 543
 544         if (ctx)
 545                 snprintf(buf, bufsize, "%s::%s", ctx->info.plugin_name, name);
 546         else
 547                 snprintf(buf, bufsize, "core::%s", name);
 548         return buf;
 549 } /* plugin_get_name */
 550
 551 static int
 552 plugin_add_callback(sdb_llist_t **list, const char *type,
 553                 const char *name, void *callback, sdb_object_t *user_data)
 554 {
 555         sdb_object_t *obj;
 556
 557         if ((! name) || (! callback))
 558                 return -1;
 559
 560         assert(list);
 561
 562         if (! *list)
 563                 *list = sdb_llist_create();
 564         if (! *list)
 565                 return -1;
 566
 567         obj = sdb_object_create(name, sdb_plugin_cb_type,
 568                         list, type, callback, user_data);
 569         if (! obj)
 570                 return -1;
 571
 572         if (sdb_llist_append(*list, obj)) {
 573                 sdb_object_deref(obj);
 574                 return -1;
 575         }
 576
 577         /* pass control to the list */
 578         sdb_object_deref(obj);
 579
 580         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 581                         type, name);
 582         return 0;
 583 } /* plugin_add_callback */
 584
 585 /*
 586  * public API
 587  */
 588
 589 int
 590 sdb_plugin_load(const char *basedir, const char *name,
 591                 const sdb_plugin_ctx_t *plugin_ctx)
 592 {
 593         ctx_t *ctx;
 594
 595         int status;
 596
 597         if ((! name) || (! *name))
 598                 return -1;
 599
 600         if (! all_plugins) {
 601                 if (! (all_plugins = sdb_llist_create())) {
 602                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 603                                         "internal error while creating linked list", name);
 604                         return -1;
 605                 }
 606         }
 607
 608         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 609         if (ctx) {
 610                 /* plugin already loaded */
 611                 if (! ctx->use_cnt) {
 612                         /* reloading plugin */
 613                         ctx_t *old_ctx = ctx_set(ctx);
 614
 615                         status = module_init(ctx->info.plugin_name, ctx->handle, NULL);
 616                         if (status)
 617                                 return status;
 618
 619                         sdb_log(SDB_LOG_INFO, "core: Successfully reloaded plugin "
 620                                         "'%s' (%s)", ctx->info.plugin_name,
 621                                         INFO_GET(&ctx->info, description));
 622                         ctx_set(old_ctx);
 623                 }
 624                 ++ctx->use_cnt;
 625                 return 0;
 626         }
 627
 628         return module_load(basedir, name, plugin_ctx);
 629 } /* sdb_plugin_load */
 630
 631 int
 632 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 633 {
 634         va_list ap;
 635
 636         if (! info)
 637                 return -1;
 638
 639         va_start(ap, type);
 640
 641         switch (type) {
 642                 case SDB_PLUGIN_INFO_DESC:
 643                         {
 644                                 char *desc = va_arg(ap, char *);
 645                                 if (desc) {
 646                                         if (info->description)
 647                                                 free(info->description);
 648                                         info->description = strdup(desc);
 649                                 }
 650                         }
 651                         break;
 652                 case SDB_PLUGIN_INFO_COPYRIGHT:
 653                         {
 654                                 char *copyright = va_arg(ap, char *);
 655                                 if (copyright)
 656                                         info->copyright = strdup(copyright);
 657                         }
 658                         break;
 659                 case SDB_PLUGIN_INFO_LICENSE:
 660                         {
 661                                 char *license = va_arg(ap, char *);
 662                                 if (license) {
 663                                         if (info->license)
 664                                                 free(info->license);
 665                                         info->license = strdup(license);
 666                                 }
 667                         }
 668                         break;
 669                 case SDB_PLUGIN_INFO_VERSION:
 670                         {
 671                                 int version = va_arg(ap, int);
 672                                 info->version = version;
 673                         }
 674                         break;
 675                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 676                         {
 677                                 int version = va_arg(ap, int);
 678                                 info->plugin_version = version;
 679                         }
 680                         break;
 681                 default:
 682                         va_end(ap);
 683                         return -1;
 684         }
 685
 686         va_end(ap);
 687         return 0;
 688 } /* sdb_plugin_set_info */
 689
 690 int
 691 sdb_plugin_register_config(sdb_plugin_config_cb callback)
 692 {
 693         ctx_t *ctx = ctx_get();
 694
 695         if (! ctx) {
 696                 sdb_log(SDB_LOG_ERR, "core: Invalid attempt to register a "
 697                                 "config callback from outside a plugin");
 698                 return -1;
 699         }
 700         return plugin_add_callback(&config_list, "init", ctx->info.plugin_name,
 701                         (void *)callback, NULL);
 702 } /* sdb_plugin_register_config */
 703
 704 int
 705 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 706                 sdb_object_t *user_data)
 707 {
 708         char cb_name[1024];
 709         return plugin_add_callback(&init_list, "init",
 710                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 711                         (void *)callback, user_data);
 712 } /* sdb_plugin_register_init */
 713
 714 int
 715 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 716                 sdb_object_t *user_data)
 717 {
 718         char cb_name[1024];
 719         return plugin_add_callback(&shutdown_list, "shutdown",
 720                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 721                         (void *)callback, user_data);
 722 } /* sdb_plugin_register_shutdown */
 723
 724 int
 725 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 726                 sdb_object_t *user_data)
 727 {
 728         char cb_name[1024];
 729         return plugin_add_callback(&log_list, "log",
 730                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 731                         callback, user_data);
 732 } /* sdb_plugin_register_log */
 733
 734 int
 735 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 736                 sdb_object_t *user_data)
 737 {
 738         char cb_name[1024];
 739         return plugin_add_callback(&cname_list, "cname",
 740                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 741                         callback, user_data);
 742 } /* sdb_plugin_register_cname */
 743
 744 int
 745 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 746                 const sdb_time_t *interval, sdb_object_t *user_data)
 747 {
 748         char cb_name[1024];
 749         sdb_object_t *obj;
 750
 751         if ((! name) || (! callback))
 752                 return -1;
 753
 754         if (! collector_list)
 755                 collector_list = sdb_llist_create();
 756         if (! collector_list)
 757                 return -1;
 758
 759         plugin_get_name(name, cb_name, sizeof(cb_name));
 760
 761         obj = sdb_object_create(cb_name, sdb_plugin_collector_cb_type,
 762                         &collector_list, "collector", callback, user_data);
 763         if (! obj)
 764                 return -1;
 765
 766         if (interval)
 767                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 768         else {
 769                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 770
 771                 if (tmp > 0)
 772                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 773                 else
 774                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 775         }
 776
 777         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 778                 char errbuf[1024];
 779                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 780                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 781                 sdb_object_deref(obj);
 782                 return -1;
 783         }
 784
 785         if (sdb_llist_insert_sorted(collector_list, obj,
 786                                 plugin_cmp_next_update)) {
 787                 sdb_object_deref(obj);
 788                 return -1;
 789         }
 790
 791         /* pass control to the list */
 792         sdb_object_deref(obj);
 793
 794         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 795                         "(interval = %.3fs).", cb_name,
 796                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 797         return 0;
 798 } /* sdb_plugin_register_collector */
 799
 800 sdb_plugin_ctx_t
 801 sdb_plugin_get_ctx(void)
 802 {
 803         ctx_t *c;
 804
 805         c = ctx_get();
 806         if (! c) {
 807                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 808                                 "context outside a plugin");
 809                 return plugin_default_ctx;
 810         }
 811         return c->public;
 812 } /* sdb_plugin_get_ctx */
 813
 814 int
 815 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 816 {
 817         ctx_t *c;
 818
 819         c = ctx_get();
 820         if (! c) {
 821                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 822                                 "context outside a plugin");
 823                 return -1;
 824         }
 825
 826         if (old)
 827                 *old = c->public;
 828         c->public = ctx;
 829         return 0;
 830 } /* sdb_plugin_set_ctx */
 831
 832 int
 833 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 834 {
 835         sdb_plugin_cb_t *plugin;
 836         sdb_plugin_config_cb callback;
 837
 838         ctx_t *old_ctx;
 839
 840         int status;
 841
 842         if ((! name) || (! ci))
 843                 return -1;
 844
 845         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 846         if (! plugin) {
 847                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 848                 if (! ctx)
 849                         sdb_log(SDB_LOG_ERR, "core: Cannot configure unknown "
 850                                         "plugin '%s'. Missing 'LoadPlugin \"%s\"'?",
 851                                         name, name);
 852                 else
 853                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 854                                         "a config callback.", name);
 855                 errno = ENOENT;
 856                 return -1;
 857         }
 858
 859         old_ctx = ctx_set(plugin->cb_ctx);
 860         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 861         status = callback(ci);
 862         ctx_set(old_ctx);
 863         return status;
 864 } /* sdb_plugin_configure */
 865
 866 int
 867 sdb_plugin_reconfigure_init(void)
 868 {
 869         sdb_llist_iter_t *iter;
 870
 871         iter = sdb_llist_get_iter(config_list);
 872         if (config_list && (! iter))
 873                 return -1;
 874
 875         /* deconfigure all plugins */
 876         while (sdb_llist_iter_has_next(iter)) {
 877                 sdb_plugin_cb_t *plugin;
 878                 sdb_plugin_config_cb callback;
 879                 ctx_t *old_ctx;
 880
 881                 plugin = SDB_PLUGIN_CB(sdb_llist_iter_get_next(iter));
 882                 old_ctx = ctx_set(plugin->cb_ctx);
 883                 callback = (sdb_plugin_config_cb)plugin->cb_callback;
 884                 callback(NULL);
 885                 ctx_set(old_ctx);
 886         }
 887         sdb_llist_iter_destroy(iter);
 888
 889         iter = sdb_llist_get_iter(all_plugins);
 890         if (all_plugins && (! iter))
 891                 return -1;
 892
 893         /* record all plugins as being unused */
 894         while (sdb_llist_iter_has_next(iter))
 895                 CTX(sdb_llist_iter_get_next(iter))->use_cnt = 0;
 896         sdb_llist_iter_destroy(iter);
 897
 898         plugin_unregister_all();
 899         return 0;
 900 } /* sdb_plugin_reconfigure_init */
 901
 902 int
 903 sdb_plugin_reconfigure_finish(void)
 904 {
 905         sdb_llist_iter_t *iter;
 906
 907         iter = sdb_llist_get_iter(all_plugins);
 908         if (all_plugins && (! iter))
 909                 return -1;
 910
 911         while (sdb_llist_iter_has_next(iter)) {
 912                 ctx_t *ctx = CTX(sdb_llist_iter_get_next(iter));
 913                 if (ctx->use_cnt)
 914                         continue;
 915
 916                 sdb_log(SDB_LOG_INFO, "core: Module %s no longer in use",
 917                                 ctx->info.plugin_name);
 918                 sdb_llist_iter_remove_current(iter);
 919                 plugin_unregister_by_name(ctx->info.plugin_name);
 920                 sdb_object_deref(SDB_OBJ(ctx));
 921         }
 922         sdb_llist_iter_destroy(iter);
 923         return 0;
 924 } /* sdb_plugin_reconfigure_finish */
 925
 926 int
 927 sdb_plugin_init_all(void)
 928 {
 929         sdb_llist_iter_t *iter;
 930         int ret = 0;
 931
 932         iter = sdb_llist_get_iter(init_list);
 933         while (sdb_llist_iter_has_next(iter)) {
 934                 sdb_plugin_cb_t *cb;
 935                 sdb_plugin_init_cb callback;
 936                 ctx_t *old_ctx;
 937
 938                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 939                 assert(obj);
 940                 cb = SDB_PLUGIN_CB(obj);
 941
 942                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 943
 944                 old_ctx = ctx_set(cb->cb_ctx);
 945                 if (callback(cb->cb_user_data)) {
 946                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 947                                         "'%s'. Unregistering all callbacks.", obj->name);
 948                         ctx_set(old_ctx);
 949                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 950                         ++ret;
 951                 }
 952                 else
 953                         ctx_set(old_ctx);
 954         }
 955         sdb_llist_iter_destroy(iter);
 956         return ret;
 957 } /* sdb_plugin_init_all */
 958
 959 int
 960 sdb_plugin_shutdown_all(void)
 961 {
 962         sdb_llist_iter_t *iter;
 963         int ret = 0;
 964
 965         iter = sdb_llist_get_iter(shutdown_list);
 966         while (sdb_llist_iter_has_next(iter)) {
 967                 sdb_plugin_cb_t *cb;
 968                 sdb_plugin_shutdown_cb callback;
 969                 ctx_t *old_ctx;
 970
 971                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 972                 assert(obj);
 973                 cb = SDB_PLUGIN_CB(obj);
 974
 975                 callback = (sdb_plugin_shutdown_cb)cb->cb_callback;
 976
 977                 old_ctx = ctx_set(cb->cb_ctx);
 978                 if (callback(cb->cb_user_data)) {
 979                         sdb_log(SDB_LOG_ERR, "core: Failed to shutdown plugin '%s'.",
 980                                         obj->name);
 981                         ++ret;
 982                 }
 983                 ctx_set(old_ctx);
 984         }
 985         sdb_llist_iter_destroy(iter);
 986         return ret;
 987 } /* sdb_plugin_shutdown_all */
 988
 989 int
 990 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 991 {
 992         if (! collector_list) {
 993                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
 994                                 "Quiting main loop.");
 995                 return -1;
 996         }
 997
 998         if (! loop)
 999                 return -1;
1000
1001         while (loop->do_loop) {
1002                 sdb_plugin_collector_cb callback;
1003                 ctx_t *old_ctx;
1004
1005                 sdb_time_t interval, now;
1006
1007                 sdb_object_t *obj = sdb_llist_shift(collector_list);
1008                 if (! obj)
1009                         return -1;
1010
1011                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
1012
1013                 if (! (now = sdb_gettime())) {
1014                         char errbuf[1024];
1015                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1016                                         "time in collector main loop: %s",
1017                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1018                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1019                 }
1020
1021                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1022                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
1023
1024                         errno = 0;
1025                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
1026                                 if (errno != EINTR) {
1027                                         char errbuf[1024];
1028                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
1029                                                         "in collector main loop: %s",
1030                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1031                                         sdb_llist_insert_sorted(collector_list, obj,
1032                                                         plugin_cmp_next_update);
1033                                         sdb_object_deref(obj);
1034                                         return -1;
1035                                 }
1036                                 errno = 0;
1037                         }
1038
1039                         if (! loop->do_loop) {
1040                                 /* put back; don't worry about errors */
1041                                 sdb_llist_insert_sorted(collector_list, obj,
1042                                                 plugin_cmp_next_update);
1043                                 sdb_object_deref(obj);
1044                                 return 0;
1045                         }
1046                 }
1047
1048                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
1049                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
1050                         /* XXX */
1051                 }
1052                 ctx_set(old_ctx);
1053
1054                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
1055                 if (! interval)
1056                         interval = loop->default_interval;
1057                 if (! interval) {
1058                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
1059                                         "for plugin '%s'; skipping any further "
1060                                         "iterations.", obj->name);
1061                         sdb_object_deref(obj);
1062                         continue;
1063                 }
1064
1065                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
1066
1067                 if (! (now = sdb_gettime())) {
1068                         char errbuf[1024];
1069                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1070                                         "time in collector main loop: %s",
1071                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1072                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1073                 }
1074
1075                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1076                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
1077                                         "long; skipping iterations to keep up.",
1078                                         obj->name);
1079                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
1080                 }
1081
1082                 if (sdb_llist_insert_sorted(collector_list, obj,
1083                                         plugin_cmp_next_update)) {
1084                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
1085                                         "plugin '%s' into collector list. Unable to further "
1086                                         "use the plugin.",
1087                                         obj->name);
1088                         sdb_object_deref(obj);
1089                         return -1;
1090                 }
1091
1092                 /* pass control back to the list */
1093                 sdb_object_deref(obj);
1094         }
1095         return 0;
1096 } /* sdb_plugin_read_loop */
1097
1098 char *
1099 sdb_plugin_cname(char *hostname)
1100 {
1101         sdb_llist_iter_t *iter;
1102
1103         if (! hostname)
1104                 return NULL;
1105
1106         if (! cname_list)
1107                 return hostname;
1108
1109         iter = sdb_llist_get_iter(cname_list);
1110         while (sdb_llist_iter_has_next(iter)) {
1111                 sdb_plugin_cname_cb callback;
1112                 char *cname;
1113
1114                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1115                 assert(obj);
1116
1117                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1118                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
1119                 if (cname) {
1120                         free(hostname);
1121                         hostname = cname;
1122                 }
1123                 /* else: don't change hostname */
1124         }
1125         sdb_llist_iter_destroy(iter);
1126         return hostname;
1127 } /* sdb_plugin_cname */
1128
1129 int
1130 sdb_plugin_log(int prio, const char *msg)
1131 {
1132         sdb_llist_iter_t *iter;
1133         int ret = -1;
1134
1135         _Bool logged = 0;
1136
1137         if (! msg)
1138                 return 0;
1139
1140         iter = sdb_llist_get_iter(log_list);
1141         while (sdb_llist_iter_has_next(iter)) {
1142                 sdb_plugin_log_cb callback;
1143                 int tmp;
1144
1145                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1146                 assert(obj);
1147
1148                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1149                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
1150                 if (tmp > ret)
1151                         ret = tmp;
1152
1153                 if (SDB_PLUGIN_CB(obj)->cb_ctx)
1154                         logged = 1;
1155                 /* else: this is an internally registered callback */
1156         }
1157         sdb_llist_iter_destroy(iter);
1158
1159         if (! logged)
1160                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
1161         return ret;
1162 } /* sdb_plugin_log */
1163
1164 int
1165 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
1166 {
1167         sdb_strbuf_t *buf;
1168         int ret;
1169
1170         if (! fmt)
1171                 return 0;
1172
1173         buf = sdb_strbuf_create(64);
1174         if (! buf) {
1175                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
1176                 ret += vfprintf(stderr, fmt, ap);
1177                 return ret;
1178         }
1179
1180         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1181                 sdb_strbuf_destroy(buf);
1182                 return -1;
1183         }
1184
1185         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1186         sdb_strbuf_destroy(buf);
1187         return ret;
1188 } /* sdb_plugin_vlogf */
1189
1190 int
1191 sdb_plugin_logf(int prio, const char *fmt, ...)
1192 {
1193         va_list ap;
1194         int ret;
1195
1196         if (! fmt)
1197                 return 0;
1198
1199         va_start(ap, fmt);
1200         ret = sdb_plugin_vlogf(prio, fmt, ap);
1201         va_end(ap);
1202         return ret;
1203 } /* sdb_plugin_logf */
1204
1205 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1206