src/core/plugin.c

   1 /*
   2  * SysDB - src/core/plugin.c
   3  * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "sysdb.h"
  33 #include "core/plugin.h"
  34 #include "core/time.h"
  35 #include "utils/error.h"
  36 #include "utils/llist.h"
  37 #include "utils/strbuf.h"
  38
  39 #include <assert.h>
  40
  41 #include <errno.h>
  42
  43 #include <stdarg.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <strings.h>
  47 #include <unistd.h>
  48
  49 #include <ltdl.h>
  50
  51 #include <pthread.h>
  52
  53 /*
  54  * private data types
  55  */
  56
  57 struct sdb_plugin_info {
  58         char *plugin_name;
  59         char *filename;
  60
  61         /* public attributes */
  62         char *name;
  63
  64         char *description;
  65         char *copyright;
  66         char *license;
  67
  68         int   version;
  69         int   plugin_version;
  70 };
  71 #define SDB_PLUGIN_INFO_INIT { \
  72         /* plugin_name */ NULL, /* filename */ NULL, \
  73         /* name */ NULL, /* desc */ NULL, \
  74         /* copyright */ NULL, /* license */ NULL, \
  75         /* version */ -1, /* plugin_version */ -1 }
  76 #define INFO_GET(i, attr) \
  77         ((i)->attr ? (i)->attr : #attr" not set")
  78
  79 typedef struct {
  80         sdb_object_t super;
  81         sdb_plugin_ctx_t public;
  82
  83         sdb_plugin_info_t info;
  84         lt_dlhandle handle;
  85
  86         /* The usage count differs from the object's ref count
  87          * in that it provides higher level information about how
  88          * the plugin is in use. */
  89         size_t use_cnt;
  90 } ctx_t;
  91 #define CTX_INIT { SDB_OBJECT_INIT, \
  92         SDB_PLUGIN_CTX_INIT, SDB_PLUGIN_INFO_INIT, NULL, 0 }
  93
  94 #define CTX(obj) ((ctx_t *)(obj))
  95
  96 typedef struct {
  97         sdb_object_t super;
  98         void *cb_callback;
  99         sdb_object_t *cb_user_data;
 100         ctx_t *cb_ctx;
 101 } sdb_plugin_cb_t;
 102 #define SDB_PLUGIN_CB_INIT { SDB_OBJECT_INIT, \
 103         /* callback = */ NULL, /* user_data = */ NULL, \
 104         SDB_PLUGIN_CTX_INIT }
 105
 106 typedef struct {
 107         sdb_plugin_cb_t super;
 108 #define ccb_callback super.cb_callback
 109 #define ccb_user_data super.cb_user_data
 110 #define ccb_ctx super.cb_ctx
 111         sdb_time_t ccb_interval;
 112         sdb_time_t ccb_next_update;
 113 } sdb_plugin_collector_cb_t;
 114
 115 #define SDB_PLUGIN_CB(obj) ((sdb_plugin_cb_t *)(obj))
 116 #define SDB_CONST_PLUGIN_CB(obj) ((const sdb_plugin_cb_t *)(obj))
 117 #define SDB_PLUGIN_CCB(obj) ((sdb_plugin_collector_cb_t *)(obj))
 118 #define SDB_CONST_PLUGIN_CCB(obj) ((const sdb_plugin_collector_cb_t *)(obj))
 119
 120 /*
 121  * private variables
 122  */
 123
 124 static sdb_plugin_ctx_t  plugin_default_ctx  = SDB_PLUGIN_CTX_INIT;
 125 static sdb_plugin_info_t plugin_default_info = SDB_PLUGIN_INFO_INIT;
 126
 127 static pthread_key_t     plugin_ctx_key;
 128 static _Bool             plugin_ctx_key_initialized = 0;
 129
 130 /* a list of the plugin contexts of all registered plugins */
 131 static sdb_llist_t      *all_plugins = NULL;
 132
 133 static sdb_llist_t      *config_list = NULL;
 134 static sdb_llist_t      *init_list = NULL;
 135 static sdb_llist_t      *collector_list = NULL;
 136 static sdb_llist_t      *cname_list = NULL;
 137 static sdb_llist_t      *shutdown_list = NULL;
 138 static sdb_llist_t      *log_list = NULL;
 139
 140 static struct {
 141         const char   *type;
 142         sdb_llist_t **list;
 143 } all_lists[] = {
 144         { "config",    &config_list },
 145         { "init",      &init_list },
 146         { "collector", &collector_list },
 147         { "cname",     &cname_list },
 148         { "shutdown",  &shutdown_list },
 149         { "log",       &log_list },
 150 };
 151
 152 /*
 153  * private helper functions
 154  */
 155
 156 static void
 157 plugin_info_clear(sdb_plugin_info_t *info)
 158 {
 159         sdb_plugin_info_t empty_info = SDB_PLUGIN_INFO_INIT;
 160         if (! info)
 161                 return;
 162
 163         if (info->plugin_name)
 164                 free(info->plugin_name);
 165         if (info->filename)
 166                 free(info->filename);
 167
 168         if (info->name)
 169                 free(info->name);
 170         if (info->description)
 171                 free(info->description);
 172         if (info->copyright)
 173                 free(info->copyright);
 174         if (info->license)
 175                 free(info->license);
 176
 177         *info = empty_info;
 178 } /* plugin_info_clear */
 179
 180 static void
 181 ctx_key_init(void)
 182 {
 183         if (plugin_ctx_key_initialized)
 184                 return;
 185
 186         pthread_key_create(&plugin_ctx_key, /* destructor */ NULL);
 187         plugin_ctx_key_initialized = 1;
 188 } /* ctx_key_init */
 189
 190 static int
 191 plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
 192 {
 193         const sdb_plugin_collector_cb_t *ccb1
 194                 = (const sdb_plugin_collector_cb_t *)a;
 195         const sdb_plugin_collector_cb_t *ccb2
 196                 = (const sdb_plugin_collector_cb_t *)b;
 197
 198         assert(ccb1 && ccb2);
 199
 200         return (ccb1->ccb_next_update > ccb2->ccb_next_update)
 201                 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
 202                 ? -1 : 0;
 203 } /* plugin_cmp_next_update */
 204
 205 static int
 206 plugin_lookup_by_name(const sdb_object_t *obj, const void *id)
 207 {
 208         const sdb_plugin_cb_t *cb = SDB_CONST_PLUGIN_CB(obj);
 209         const char *name = id;
 210
 211         assert(cb && id);
 212
 213         /* when a plugin was registered from outside a plugin (e.g. the core),
 214          * we don't have a plugin context */
 215         if (! cb->cb_ctx)
 216                 return 1;
 217
 218         if (!strcasecmp(cb->cb_ctx->info.plugin_name, name))
 219                 return 0;
 220         return 1;
 221 } /* plugin_lookup_by_name */
 222
 223 /* since this function is called from sdb_plugin_reconfigure_finish()
 224  * when iterating through all_plugins, we may not do any additional
 225  * modifications to all_plugins except for the optional removal */
 226 static void
 227 plugin_unregister_by_name(const char *plugin_name)
 228 {
 229         sdb_object_t *obj;
 230         size_t i;
 231
 232         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 233                 const char  *type =  all_lists[i].type;
 234                 sdb_llist_t *list = *all_lists[i].list;
 235
 236                 while (1) {
 237                         sdb_plugin_cb_t *cb;
 238
 239                         cb = SDB_PLUGIN_CB(sdb_llist_remove(list,
 240                                                 plugin_lookup_by_name, plugin_name));
 241                         if (! cb)
 242                                 break;
 243
 244                         assert(cb->cb_ctx);
 245
 246                         sdb_log(SDB_LOG_INFO, "core: Unregistering "
 247                                         "%s callback '%s' (module %s)", type, cb->super.name,
 248                                         cb->cb_ctx->info.plugin_name);
 249                         sdb_object_deref(SDB_OBJ(cb));
 250                 }
 251         }
 252
 253         obj = sdb_llist_search_by_name(all_plugins, plugin_name);
 254         /* when called from sdb_plugin_reconfigure_finish, the object has already
 255          * been removed from the list */
 256         if (obj && (obj->ref_cnt <= 1)) {
 257                 sdb_llist_remove_by_name(all_plugins, plugin_name);
 258                 sdb_object_deref(obj);
 259         }
 260         /* else: other callbacks still reference it */
 261 } /* plugin_unregister_by_name */
 262
 263 static void
 264 plugin_unregister_all(void)
 265 {
 266         size_t i;
 267
 268         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 269                 const char  *type =  all_lists[i].type;
 270                 sdb_llist_t *list = *all_lists[i].list;
 271
 272                 size_t len = sdb_llist_len(list);
 273
 274                 if (! len)
 275                         continue;
 276
 277                 sdb_llist_clear(list);
 278                 sdb_log(SDB_LOG_INFO, "core: Unregistered %zu %s callback%s",
 279                                 len, type, len == 1 ? "" : "s");
 280         }
 281 } /* plugin_unregister_all */
 282
 283 /*
 284  * private types
 285  */
 286
 287 static int
 288 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 289 {
 290         ctx_t *ctx = CTX(obj);
 291
 292         assert(ctx);
 293
 294         ctx->public = plugin_default_ctx;
 295         ctx->info = plugin_default_info;
 296         ctx->handle = NULL;
 297         ctx->use_cnt = 1;
 298         return 0;
 299 } /* ctx_init */
 300
 301 static void
 302 ctx_destroy(sdb_object_t *obj)
 303 {
 304         ctx_t *ctx = CTX(obj);
 305
 306         if (ctx->handle) {
 307                 const char *err;
 308
 309                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s",
 310                                 ctx->info.plugin_name);
 311
 312                 lt_dlerror();
 313                 lt_dlclose(ctx->handle);
 314                 if ((err = lt_dlerror()))
 315                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload module %s: %s",
 316                                         ctx->info.plugin_name, err);
 317         }
 318
 319         plugin_info_clear(&ctx->info);
 320 } /* ctx_destroy */
 321
 322 static sdb_type_t ctx_type = {
 323         sizeof(ctx_t),
 324
 325         ctx_init,
 326         ctx_destroy
 327 };
 328
 329 static ctx_t *
 330 ctx_get(void)
 331 {
 332         if (! plugin_ctx_key_initialized)
 333                 ctx_key_init();
 334         return pthread_getspecific(plugin_ctx_key);
 335 } /* ctx_get */
 336
 337 static ctx_t *
 338 ctx_set(ctx_t *new)
 339 {
 340         ctx_t *old;
 341
 342         if (! plugin_ctx_key_initialized)
 343                 ctx_key_init();
 344
 345         old = pthread_getspecific(plugin_ctx_key);
 346         if (old)
 347                 sdb_object_deref(SDB_OBJ(old));
 348         if (new)
 349                 sdb_object_ref(SDB_OBJ(new));
 350         pthread_setspecific(plugin_ctx_key, new);
 351         return old;
 352 } /* ctx_set */
 353
 354 static ctx_t *
 355 ctx_create(const char *name)
 356 {
 357         ctx_t *ctx;
 358
 359         ctx = CTX(sdb_object_create(name, ctx_type));
 360         if (! ctx)
 361                 return NULL;
 362
 363         if (! plugin_ctx_key_initialized)
 364                 ctx_key_init();
 365         ctx_set(ctx);
 366         return ctx;
 367 } /* ctx_create */
 368
 369 static int
 370 plugin_cb_init(sdb_object_t *obj, va_list ap)
 371 {
 372         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 373         const char   *type = va_arg(ap, const char *);
 374         void     *callback = va_arg(ap, void *);
 375         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 376
 377         assert(list);
 378         assert(type);
 379         assert(obj);
 380
 381         if (sdb_llist_search_by_name(*list, obj->name)) {
 382                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 383                                 "has already been registered. Ignoring newly "
 384                                 "registered version.", type, obj->name);
 385                 return -1;
 386         }
 387
 388         /* cb_ctx may be NULL if the plugin was not registered by a plugin */
 389
 390         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 391         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 392         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 393
 394         sdb_object_ref(ud);
 395         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 396         return 0;
 397 } /* plugin_cb_init */
 398
 399 static void
 400 plugin_cb_destroy(sdb_object_t *obj)
 401 {
 402         assert(obj);
 403         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 404         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 405 } /* plugin_cb_destroy */
 406
 407 static sdb_type_t sdb_plugin_cb_type = {
 408         sizeof(sdb_plugin_cb_t),
 409
 410         plugin_cb_init,
 411         plugin_cb_destroy
 412 };
 413
 414 static sdb_type_t sdb_plugin_collector_cb_type = {
 415         sizeof(sdb_plugin_collector_cb_t),
 416
 417         plugin_cb_init,
 418         plugin_cb_destroy
 419 };
 420
 421 static int
 422 module_init(const char *name, lt_dlhandle lh, sdb_plugin_info_t *info)
 423 {
 424         int (*mod_init)(sdb_plugin_info_t *);
 425         int status;
 426
 427         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 428         if (! mod_init) {
 429                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 430                                 "could not find symbol 'sdb_module_init'", name);
 431                 return -1;
 432         }
 433
 434         status = mod_init(info);
 435         if (status) {
 436                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 437                                 "module '%s'", name);
 438                 plugin_unregister_by_name(name);
 439                 return -1;
 440         }
 441         return 0;
 442 } /* module_init */
 443
 444 static int
 445 module_load(const char *basedir, const char *name,
 446                 const sdb_plugin_ctx_t *plugin_ctx)
 447 {
 448         char  base_name[name ? strlen(name) + 1 : 1];
 449         const char *name_ptr;
 450         char *tmp;
 451
 452         char filename[1024];
 453         lt_dlhandle lh;
 454
 455         ctx_t *ctx;
 456
 457         int status;
 458
 459         assert(name);
 460
 461         base_name[0] = '\0';
 462         name_ptr = name;
 463
 464         while ((tmp = strstr(name_ptr, "::"))) {
 465                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 466                 strcat(base_name, "/");
 467                 name_ptr = tmp + strlen("::");
 468         }
 469         strcat(base_name, name_ptr);
 470
 471         if (! basedir)
 472                 basedir = PKGLIBDIR;
 473
 474         snprintf(filename, sizeof(filename), "%s/%s.so", basedir, base_name);
 475         filename[sizeof(filename) - 1] = '\0';
 476
 477         if (access(filename, R_OK)) {
 478                 char errbuf[1024];
 479                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 480                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 481                 return -1;
 482         }
 483
 484         lt_dlinit();
 485         lt_dlerror();
 486
 487         lh = lt_dlopen(filename);
 488         if (! lh) {
 489                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 490                                 "The most common cause for this problem are missing "
 491                                 "dependencies.\n", name, lt_dlerror());
 492                 return -1;
 493         }
 494
 495         if (ctx_get())
 496                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 497
 498         ctx = ctx_create(name);
 499         if (! ctx) {
 500                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 501                 return -1;
 502         }
 503
 504         ctx->info.plugin_name = strdup(name);
 505         ctx->info.filename = strdup(filename);
 506         ctx->handle = lh;
 507
 508         if (plugin_ctx)
 509                 ctx->public = *plugin_ctx;
 510
 511         if ((status = module_init(name, lh, &ctx->info))) {
 512                 sdb_object_deref(SDB_OBJ(ctx));
 513                 return status;
 514         }
 515
 516         /* compare minor version */
 517         if ((ctx->info.version < 0)
 518                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 519                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 520                                 "plugin '%s' (%i.%i.%i) does not match our version "
 521                                 "(%i.%i.%i); this might cause problems",
 522                                 name, SDB_VERSION_DECODE(ctx->info.version),
 523                                 SDB_VERSION_DECODE(SDB_VERSION));
 524
 525         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 526
 527         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 528                         "plugin '%s' v%i (%s)\n\t%s\n\tLicense: %s",
 529                         INFO_GET(&ctx->info, name), ctx->info.plugin_version,
 530                         INFO_GET(&ctx->info, description),
 531                         INFO_GET(&ctx->info, copyright),
 532                         INFO_GET(&ctx->info, license));
 533
 534         /* any registered callbacks took ownership of the context */
 535         sdb_object_deref(SDB_OBJ(ctx));
 536
 537         /* reset */
 538         ctx_set(NULL);
 539         return 0;
 540 } /* module_load */
 541
 542 static char *
 543 plugin_get_name(const char *name, char *buf, size_t bufsize)
 544 {
 545         ctx_t *ctx = ctx_get();
 546
 547         if (ctx)
 548                 snprintf(buf, bufsize, "%s::%s", ctx->info.plugin_name, name);
 549         else
 550                 snprintf(buf, bufsize, "core::%s", name);
 551         return buf;
 552 } /* plugin_get_name */
 553
 554 static int
 555 plugin_add_callback(sdb_llist_t **list, const char *type,
 556                 const char *name, void *callback, sdb_object_t *user_data)
 557 {
 558         sdb_object_t *obj;
 559
 560         if ((! name) || (! callback))
 561                 return -1;
 562
 563         assert(list);
 564
 565         if (! *list)
 566                 *list = sdb_llist_create();
 567         if (! *list)
 568                 return -1;
 569
 570         obj = sdb_object_create(name, sdb_plugin_cb_type,
 571                         list, type, callback, user_data);
 572         if (! obj)
 573                 return -1;
 574
 575         if (sdb_llist_append(*list, obj)) {
 576                 sdb_object_deref(obj);
 577                 return -1;
 578         }
 579
 580         /* pass control to the list */
 581         sdb_object_deref(obj);
 582
 583         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 584                         type, name);
 585         return 0;
 586 } /* plugin_add_callback */
 587
 588 /*
 589  * public API
 590  */
 591
 592 int
 593 sdb_plugin_load(const char *basedir, const char *name,
 594                 const sdb_plugin_ctx_t *plugin_ctx)
 595 {
 596         ctx_t *ctx;
 597
 598         int status;
 599
 600         if ((! name) || (! *name))
 601                 return -1;
 602
 603         if (! all_plugins) {
 604                 if (! (all_plugins = sdb_llist_create())) {
 605                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 606                                         "internal error while creating linked list", name);
 607                         return -1;
 608                 }
 609         }
 610
 611         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 612         if (ctx) {
 613                 /* plugin already loaded */
 614                 if (! ctx->use_cnt) {
 615                         /* reloading plugin */
 616                         ctx_t *old_ctx = ctx_set(ctx);
 617
 618                         status = module_init(ctx->info.plugin_name, ctx->handle, NULL);
 619                         if (status)
 620                                 return status;
 621
 622                         sdb_log(SDB_LOG_INFO, "core: Successfully reloaded plugin "
 623                                         "'%s' (%s)", INFO_GET(&ctx->info, name),
 624                                         INFO_GET(&ctx->info, description));
 625                         ctx_set(old_ctx);
 626                 }
 627                 ++ctx->use_cnt;
 628                 return 0;
 629         }
 630
 631         return module_load(basedir, name, plugin_ctx);
 632 } /* sdb_plugin_load */
 633
 634 int
 635 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 636 {
 637         va_list ap;
 638
 639         if (! info)
 640                 return -1;
 641
 642         va_start(ap, type);
 643
 644         switch (type) {
 645                 case SDB_PLUGIN_INFO_NAME:
 646                         {
 647                                 char *name = va_arg(ap, char *);
 648                                 if (name) {
 649                                         if (info->name)
 650                                                 free(info->name);
 651                                         info->name = strdup(name);
 652                                 }
 653                         }
 654                         break;
 655                 case SDB_PLUGIN_INFO_DESC:
 656                         {
 657                                 char *desc = va_arg(ap, char *);
 658                                 if (desc) {
 659                                         if (info->description)
 660                                                 free(info->description);
 661                                         info->description = strdup(desc);
 662                                 }
 663                         }
 664                         break;
 665                 case SDB_PLUGIN_INFO_COPYRIGHT:
 666                         {
 667                                 char *copyright = va_arg(ap, char *);
 668                                 if (copyright)
 669                                         info->copyright = strdup(copyright);
 670                         }
 671                         break;
 672                 case SDB_PLUGIN_INFO_LICENSE:
 673                         {
 674                                 char *license = va_arg(ap, char *);
 675                                 if (license) {
 676                                         if (info->license)
 677                                                 free(info->license);
 678                                         info->license = strdup(license);
 679                                 }
 680                         }
 681                         break;
 682                 case SDB_PLUGIN_INFO_VERSION:
 683                         {
 684                                 int version = va_arg(ap, int);
 685                                 info->version = version;
 686                         }
 687                         break;
 688                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 689                         {
 690                                 int version = va_arg(ap, int);
 691                                 info->plugin_version = version;
 692                         }
 693                         break;
 694                 default:
 695                         va_end(ap);
 696                         return -1;
 697         }
 698
 699         va_end(ap);
 700         return 0;
 701 } /* sdb_plugin_set_info */
 702
 703 int
 704 sdb_plugin_register_config(sdb_plugin_config_cb callback)
 705 {
 706         ctx_t *ctx = ctx_get();
 707
 708         if (! ctx) {
 709                 sdb_log(SDB_LOG_ERR, "core: Invalid attempt to register a "
 710                                 "config callback from outside a plugin");
 711                 return -1;
 712         }
 713         return plugin_add_callback(&config_list, "init", ctx->info.plugin_name,
 714                         (void *)callback, NULL);
 715 } /* sdb_plugin_register_config */
 716
 717 int
 718 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 719                 sdb_object_t *user_data)
 720 {
 721         char cb_name[1024];
 722         return plugin_add_callback(&init_list, "init",
 723                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 724                         (void *)callback, user_data);
 725 } /* sdb_plugin_register_init */
 726
 727 int
 728 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 729                 sdb_object_t *user_data)
 730 {
 731         char cb_name[1024];
 732         return plugin_add_callback(&shutdown_list, "shutdown",
 733                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 734                         (void *)callback, user_data);
 735 } /* sdb_plugin_register_shutdown */
 736
 737 int
 738 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 739                 sdb_object_t *user_data)
 740 {
 741         char cb_name[1024];
 742         return plugin_add_callback(&log_list, "log",
 743                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 744                         callback, user_data);
 745 } /* sdb_plugin_register_log */
 746
 747 int
 748 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 749                 sdb_object_t *user_data)
 750 {
 751         char cb_name[1024];
 752         return plugin_add_callback(&cname_list, "cname",
 753                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 754                         callback, user_data);
 755 } /* sdb_plugin_register_cname */
 756
 757 int
 758 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 759                 const sdb_time_t *interval, sdb_object_t *user_data)
 760 {
 761         char cb_name[1024];
 762         sdb_object_t *obj;
 763
 764         if ((! name) || (! callback))
 765                 return -1;
 766
 767         if (! collector_list)
 768                 collector_list = sdb_llist_create();
 769         if (! collector_list)
 770                 return -1;
 771
 772         plugin_get_name(name, cb_name, sizeof(cb_name));
 773
 774         obj = sdb_object_create(cb_name, sdb_plugin_collector_cb_type,
 775                         &collector_list, "collector", callback, user_data);
 776         if (! obj)
 777                 return -1;
 778
 779         if (interval)
 780                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 781         else {
 782                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 783
 784                 if (tmp > 0)
 785                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 786                 else
 787                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 788         }
 789
 790         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 791                 char errbuf[1024];
 792                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 793                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 794                 sdb_object_deref(obj);
 795                 return -1;
 796         }
 797
 798         if (sdb_llist_insert_sorted(collector_list, obj,
 799                                 plugin_cmp_next_update)) {
 800                 sdb_object_deref(obj);
 801                 return -1;
 802         }
 803
 804         /* pass control to the list */
 805         sdb_object_deref(obj);
 806
 807         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 808                         "(interval = %.3fs).", cb_name,
 809                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 810         return 0;
 811 } /* sdb_plugin_register_collector */
 812
 813 sdb_plugin_ctx_t
 814 sdb_plugin_get_ctx(void)
 815 {
 816         ctx_t *c;
 817
 818         c = ctx_get();
 819         if (! c) {
 820                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 821                                 "context outside a plugin");
 822                 return plugin_default_ctx;
 823         }
 824         return c->public;
 825 } /* sdb_plugin_get_ctx */
 826
 827 int
 828 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 829 {
 830         ctx_t *c;
 831
 832         c = ctx_get();
 833         if (! c) {
 834                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 835                                 "context outside a plugin");
 836                 return -1;
 837         }
 838
 839         if (old)
 840                 *old = c->public;
 841         c->public = ctx;
 842         return 0;
 843 } /* sdb_plugin_set_ctx */
 844
 845 int
 846 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 847 {
 848         sdb_plugin_cb_t *plugin;
 849         sdb_plugin_config_cb callback;
 850
 851         ctx_t *old_ctx;
 852
 853         int status;
 854
 855         if ((! name) || (! ci))
 856                 return -1;
 857
 858         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 859         if (! plugin) {
 860                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 861                 if (! ctx)
 862                         sdb_log(SDB_LOG_ERR, "core: Cannot configure unknown "
 863                                         "plugin '%s'. Missing 'LoadPlugin \"%s\"'?",
 864                                         name, name);
 865                 else
 866                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 867                                         "a config callback.", name);
 868                 errno = ENOENT;
 869                 return -1;
 870         }
 871
 872         old_ctx = ctx_set(plugin->cb_ctx);
 873         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 874         status = callback(ci);
 875         ctx_set(old_ctx);
 876         return status;
 877 } /* sdb_plugin_configure */
 878
 879 int
 880 sdb_plugin_reconfigure_init(void)
 881 {
 882         sdb_llist_iter_t *iter;
 883
 884         iter = sdb_llist_get_iter(config_list);
 885         if (config_list && (! iter))
 886                 return -1;
 887
 888         /* deconfigure all plugins */
 889         while (sdb_llist_iter_has_next(iter)) {
 890                 sdb_plugin_cb_t *plugin;
 891                 sdb_plugin_config_cb callback;
 892                 ctx_t *old_ctx;
 893
 894                 plugin = SDB_PLUGIN_CB(sdb_llist_iter_get_next(iter));
 895                 old_ctx = ctx_set(plugin->cb_ctx);
 896                 callback = (sdb_plugin_config_cb)plugin->cb_callback;
 897                 callback(NULL);
 898                 ctx_set(old_ctx);
 899         }
 900         sdb_llist_iter_destroy(iter);
 901
 902         iter = sdb_llist_get_iter(all_plugins);
 903         if (all_plugins && (! iter))
 904                 return -1;
 905
 906         /* record all plugins as being unused */
 907         while (sdb_llist_iter_has_next(iter))
 908                 CTX(sdb_llist_iter_get_next(iter))->use_cnt = 0;
 909         sdb_llist_iter_destroy(iter);
 910
 911         plugin_unregister_all();
 912         return 0;
 913 } /* sdb_plugin_reconfigure_init */
 914
 915 int
 916 sdb_plugin_reconfigure_finish(void)
 917 {
 918         sdb_llist_iter_t *iter;
 919
 920         iter = sdb_llist_get_iter(all_plugins);
 921         if (all_plugins && (! iter))
 922                 return -1;
 923
 924         while (sdb_llist_iter_has_next(iter)) {
 925                 ctx_t *ctx = CTX(sdb_llist_iter_get_next(iter));
 926                 if (ctx->use_cnt)
 927                         continue;
 928
 929                 sdb_log(SDB_LOG_INFO, "core: Module %s no longer in use",
 930                                 ctx->info.plugin_name);
 931                 sdb_llist_iter_remove_current(iter);
 932                 plugin_unregister_by_name(ctx->info.plugin_name);
 933                 sdb_object_deref(SDB_OBJ(ctx));
 934         }
 935         sdb_llist_iter_destroy(iter);
 936         return 0;
 937 } /* sdb_plugin_reconfigure_finish */
 938
 939 int
 940 sdb_plugin_init_all(void)
 941 {
 942         sdb_llist_iter_t *iter;
 943         int ret = 0;
 944
 945         iter = sdb_llist_get_iter(init_list);
 946         while (sdb_llist_iter_has_next(iter)) {
 947                 sdb_plugin_cb_t *cb;
 948                 sdb_plugin_init_cb callback;
 949                 ctx_t *old_ctx;
 950
 951                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 952                 assert(obj);
 953                 cb = SDB_PLUGIN_CB(obj);
 954
 955                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 956
 957                 old_ctx = ctx_set(cb->cb_ctx);
 958                 if (callback(cb->cb_user_data)) {
 959                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 960                                         "'%s'. Unregistering all callbacks.", obj->name);
 961                         ctx_set(old_ctx);
 962                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 963                         ++ret;
 964                 }
 965                 else
 966                         ctx_set(old_ctx);
 967         }
 968         sdb_llist_iter_destroy(iter);
 969         return ret;
 970 } /* sdb_plugin_init_all */
 971
 972 int
 973 sdb_plugin_shutdown_all(void)
 974 {
 975         sdb_llist_iter_t *iter;
 976         int ret = 0;
 977
 978         iter = sdb_llist_get_iter(shutdown_list);
 979         while (sdb_llist_iter_has_next(iter)) {
 980                 sdb_plugin_cb_t *cb;
 981                 sdb_plugin_shutdown_cb callback;
 982                 ctx_t *old_ctx;
 983
 984                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 985                 assert(obj);
 986                 cb = SDB_PLUGIN_CB(obj);
 987
 988                 callback = (sdb_plugin_shutdown_cb)cb->cb_callback;
 989
 990                 old_ctx = ctx_set(cb->cb_ctx);
 991                 if (callback(cb->cb_user_data)) {
 992                         sdb_log(SDB_LOG_ERR, "core: Failed to shutdown plugin '%s'.",
 993                                         obj->name);
 994                         ++ret;
 995                 }
 996                 ctx_set(old_ctx);
 997         }
 998         sdb_llist_iter_destroy(iter);
 999         return ret;
1000 } /* sdb_plugin_shutdown_all */
1001
1002 int
1003 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
1004 {
1005         if (! collector_list) {
1006                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
1007                                 "Quiting main loop.");
1008                 return -1;
1009         }
1010
1011         if (! loop)
1012                 return -1;
1013
1014         while (loop->do_loop) {
1015                 sdb_plugin_collector_cb callback;
1016                 ctx_t *old_ctx;
1017
1018                 sdb_time_t interval, now;
1019
1020                 sdb_object_t *obj = sdb_llist_shift(collector_list);
1021                 if (! obj)
1022                         return -1;
1023
1024                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
1025
1026                 if (! (now = sdb_gettime())) {
1027                         char errbuf[1024];
1028                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1029                                         "time in collector main loop: %s",
1030                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1031                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1032                 }
1033
1034                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1035                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
1036
1037                         errno = 0;
1038                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
1039                                 if (errno != EINTR) {
1040                                         char errbuf[1024];
1041                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
1042                                                         "in collector main loop: %s",
1043                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1044                                         sdb_llist_insert_sorted(collector_list, obj,
1045                                                         plugin_cmp_next_update);
1046                                         sdb_object_deref(obj);
1047                                         return -1;
1048                                 }
1049                                 errno = 0;
1050                         }
1051
1052                         if (! loop->do_loop) {
1053                                 /* put back; don't worry about errors */
1054                                 sdb_llist_insert_sorted(collector_list, obj,
1055                                                 plugin_cmp_next_update);
1056                                 sdb_object_deref(obj);
1057                                 return 0;
1058                         }
1059                 }
1060
1061                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
1062                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
1063                         /* XXX */
1064                 }
1065                 ctx_set(old_ctx);
1066
1067                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
1068                 if (! interval)
1069                         interval = loop->default_interval;
1070                 if (! interval) {
1071                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
1072                                         "for plugin '%s'; skipping any further "
1073                                         "iterations.", obj->name);
1074                         sdb_object_deref(obj);
1075                         continue;
1076                 }
1077
1078                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
1079
1080                 if (! (now = sdb_gettime())) {
1081                         char errbuf[1024];
1082                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1083                                         "time in collector main loop: %s",
1084                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1085                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1086                 }
1087
1088                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1089                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
1090                                         "long; skipping iterations to keep up.",
1091                                         obj->name);
1092                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
1093                 }
1094
1095                 if (sdb_llist_insert_sorted(collector_list, obj,
1096                                         plugin_cmp_next_update)) {
1097                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
1098                                         "plugin '%s' into collector list. Unable to further "
1099                                         "use the plugin.",
1100                                         obj->name);
1101                         sdb_object_deref(obj);
1102                         return -1;
1103                 }
1104
1105                 /* pass control back to the list */
1106                 sdb_object_deref(obj);
1107         }
1108         return 0;
1109 } /* sdb_plugin_read_loop */
1110
1111 char *
1112 sdb_plugin_cname(char *hostname)
1113 {
1114         sdb_llist_iter_t *iter;
1115
1116         if (! hostname)
1117                 return NULL;
1118
1119         if (! cname_list)
1120                 return hostname;
1121
1122         iter = sdb_llist_get_iter(cname_list);
1123         while (sdb_llist_iter_has_next(iter)) {
1124                 sdb_plugin_cname_cb callback;
1125                 char *cname;
1126
1127                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1128                 assert(obj);
1129
1130                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1131                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
1132                 if (cname) {
1133                         free(hostname);
1134                         hostname = cname;
1135                 }
1136                 /* else: don't change hostname */
1137         }
1138         sdb_llist_iter_destroy(iter);
1139         return hostname;
1140 } /* sdb_plugin_cname */
1141
1142 int
1143 sdb_plugin_log(int prio, const char *msg)
1144 {
1145         sdb_llist_iter_t *iter;
1146         int ret = -1;
1147
1148         _Bool logged = 0;
1149
1150         if (! msg)
1151                 return 0;
1152
1153         iter = sdb_llist_get_iter(log_list);
1154         while (sdb_llist_iter_has_next(iter)) {
1155                 sdb_plugin_log_cb callback;
1156                 int tmp;
1157
1158                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1159                 assert(obj);
1160
1161                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1162                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
1163                 if (tmp > ret)
1164                         ret = tmp;
1165
1166                 if (SDB_PLUGIN_CB(obj)->cb_ctx)
1167                         logged = 1;
1168                 /* else: this is an internally registered callback */
1169         }
1170         sdb_llist_iter_destroy(iter);
1171
1172         if (! logged)
1173                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
1174         return ret;
1175 } /* sdb_plugin_log */
1176
1177 int
1178 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
1179 {
1180         sdb_strbuf_t *buf;
1181         int ret;
1182
1183         if (! fmt)
1184                 return 0;
1185
1186         buf = sdb_strbuf_create(64);
1187         if (! buf) {
1188                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
1189                 ret += vfprintf(stderr, fmt, ap);
1190                 return ret;
1191         }
1192
1193         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1194                 sdb_strbuf_destroy(buf);
1195                 return -1;
1196         }
1197
1198         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1199         sdb_strbuf_destroy(buf);
1200         return ret;
1201 } /* sdb_plugin_vlogf */
1202
1203 int
1204 sdb_plugin_logf(int prio, const char *fmt, ...)
1205 {
1206         va_list ap;
1207         int ret;
1208
1209         if (! fmt)
1210                 return 0;
1211
1212         va_start(ap, fmt);
1213         ret = sdb_plugin_vlogf(prio, fmt, ap);
1214         va_end(ap);
1215         return ret;
1216 } /* sdb_plugin_logf */
1217
1218 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1219