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 /* helper to access info attributes */
  54 #define INFO_GET(i, attr) \
  55         ((i)->attr ? (i)->attr : #attr" not set")
  56
  57 /*
  58  * private data types
  59  */
  60
  61 typedef struct {
  62         sdb_object_t super;
  63         sdb_plugin_ctx_t public;
  64
  65         sdb_plugin_info_t info;
  66         lt_dlhandle handle;
  67
  68         /* The usage count differs from the object's ref count
  69          * in that it provides higher level information about how
  70          * the plugin is in use. */
  71         size_t use_cnt;
  72 } ctx_t;
  73 #define CTX_INIT { SDB_OBJECT_INIT, \
  74         SDB_PLUGIN_CTX_INIT, SDB_PLUGIN_INFO_INIT, NULL, 0 }
  75
  76 #define CTX(obj) ((ctx_t *)(obj))
  77
  78 typedef struct {
  79         sdb_object_t super;
  80         void *cb_callback;
  81         sdb_object_t *cb_user_data;
  82         ctx_t *cb_ctx;
  83 } sdb_plugin_cb_t;
  84 #define SDB_PLUGIN_CB_INIT { SDB_OBJECT_INIT, \
  85         /* callback = */ NULL, /* user_data = */ NULL, \
  86         SDB_PLUGIN_CTX_INIT }
  87
  88 typedef struct {
  89         sdb_plugin_cb_t super;
  90 #define ccb_callback super.cb_callback
  91 #define ccb_user_data super.cb_user_data
  92 #define ccb_ctx super.cb_ctx
  93         sdb_time_t ccb_interval;
  94         sdb_time_t ccb_next_update;
  95 } sdb_plugin_collector_cb_t;
  96
  97 #define SDB_PLUGIN_CB(obj) ((sdb_plugin_cb_t *)(obj))
  98 #define SDB_CONST_PLUGIN_CB(obj) ((const sdb_plugin_cb_t *)(obj))
  99 #define SDB_PLUGIN_CCB(obj) ((sdb_plugin_collector_cb_t *)(obj))
 100 #define SDB_CONST_PLUGIN_CCB(obj) ((const sdb_plugin_collector_cb_t *)(obj))
 101
 102 /*
 103  * private variables
 104  */
 105
 106 static sdb_plugin_ctx_t  plugin_default_ctx  = SDB_PLUGIN_CTX_INIT;
 107 static sdb_plugin_info_t plugin_default_info = SDB_PLUGIN_INFO_INIT;
 108
 109 static pthread_key_t     plugin_ctx_key;
 110 static bool              plugin_ctx_key_initialized = 0;
 111
 112 /* a list of the plugin contexts of all registered plugins */
 113 static sdb_llist_t      *all_plugins = NULL;
 114
 115 static sdb_llist_t      *config_list = NULL;
 116 static sdb_llist_t      *init_list = NULL;
 117 static sdb_llist_t      *collector_list = NULL;
 118 static sdb_llist_t      *cname_list = NULL;
 119 static sdb_llist_t      *shutdown_list = NULL;
 120 static sdb_llist_t      *log_list = NULL;
 121 static sdb_llist_t      *ts_fetcher_list = NULL;
 122
 123 static struct {
 124         const char   *type;
 125         sdb_llist_t **list;
 126 } all_lists[] = {
 127         { "config",             &config_list },
 128         { "init",               &init_list },
 129         { "collector",          &collector_list },
 130         { "cname",              &cname_list },
 131         { "shutdown",           &shutdown_list },
 132         { "log",                &log_list },
 133         { "timeseries fetcher", &ts_fetcher_list },
 134 };
 135
 136 /*
 137  * private helper functions
 138  */
 139
 140 static void
 141 plugin_info_clear(sdb_plugin_info_t *info)
 142 {
 143         sdb_plugin_info_t empty_info = SDB_PLUGIN_INFO_INIT;
 144         if (! info)
 145                 return;
 146
 147         if (info->plugin_name)
 148                 free(info->plugin_name);
 149         if (info->filename)
 150                 free(info->filename);
 151
 152         if (info->description)
 153                 free(info->description);
 154         if (info->copyright)
 155                 free(info->copyright);
 156         if (info->license)
 157                 free(info->license);
 158
 159         *info = empty_info;
 160 } /* plugin_info_clear */
 161
 162 static void
 163 ctx_key_init(void)
 164 {
 165         if (plugin_ctx_key_initialized)
 166                 return;
 167
 168         pthread_key_create(&plugin_ctx_key, /* destructor */ NULL);
 169         plugin_ctx_key_initialized = 1;
 170 } /* ctx_key_init */
 171
 172 static int
 173 plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
 174 {
 175         const sdb_plugin_collector_cb_t *ccb1
 176                 = (const sdb_plugin_collector_cb_t *)a;
 177         const sdb_plugin_collector_cb_t *ccb2
 178                 = (const sdb_plugin_collector_cb_t *)b;
 179
 180         assert(ccb1 && ccb2);
 181
 182         return (ccb1->ccb_next_update > ccb2->ccb_next_update)
 183                 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
 184                 ? -1 : 0;
 185 } /* plugin_cmp_next_update */
 186
 187 static int
 188 plugin_lookup_by_name(const sdb_object_t *obj, const void *id)
 189 {
 190         const sdb_plugin_cb_t *cb = SDB_CONST_PLUGIN_CB(obj);
 191         const char *name = id;
 192
 193         assert(cb && id);
 194
 195         /* when a plugin was registered from outside a plugin (e.g. the core),
 196          * we don't have a plugin context */
 197         if (! cb->cb_ctx)
 198                 return 1;
 199
 200         if (!strcasecmp(cb->cb_ctx->info.plugin_name, name))
 201                 return 0;
 202         return 1;
 203 } /* plugin_lookup_by_name */
 204
 205 /* since this function is called from sdb_plugin_reconfigure_finish()
 206  * when iterating through all_plugins, we may not do any additional
 207  * modifications to all_plugins except for the optional removal */
 208 static void
 209 plugin_unregister_by_name(const char *plugin_name)
 210 {
 211         sdb_object_t *obj;
 212         size_t i;
 213
 214         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 215                 const char  *type =  all_lists[i].type;
 216                 sdb_llist_t *list = *all_lists[i].list;
 217
 218                 while (1) {
 219                         sdb_plugin_cb_t *cb;
 220
 221                         cb = SDB_PLUGIN_CB(sdb_llist_remove(list,
 222                                                 plugin_lookup_by_name, plugin_name));
 223                         if (! cb)
 224                                 break;
 225
 226                         assert(cb->cb_ctx);
 227
 228                         sdb_log(SDB_LOG_INFO, "core: Unregistering "
 229                                         "%s callback '%s' (module %s)", type, cb->super.name,
 230                                         cb->cb_ctx->info.plugin_name);
 231                         sdb_object_deref(SDB_OBJ(cb));
 232                 }
 233         }
 234
 235         obj = sdb_llist_search_by_name(all_plugins, plugin_name);
 236         /* when called from sdb_plugin_reconfigure_finish, the object has already
 237          * been removed from the list */
 238         if (obj && (obj->ref_cnt <= 1)) {
 239                 sdb_llist_remove_by_name(all_plugins, plugin_name);
 240                 sdb_object_deref(obj);
 241         }
 242         /* else: other callbacks still reference it */
 243 } /* plugin_unregister_by_name */
 244
 245 static void
 246 plugin_unregister_all(void)
 247 {
 248         size_t i;
 249
 250         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 251                 const char  *type =  all_lists[i].type;
 252                 sdb_llist_t *list = *all_lists[i].list;
 253
 254                 size_t len = sdb_llist_len(list);
 255
 256                 if (! len)
 257                         continue;
 258
 259                 sdb_llist_clear(list);
 260                 sdb_log(SDB_LOG_INFO, "core: Unregistered %zu %s callback%s",
 261                                 len, type, len == 1 ? "" : "s");
 262         }
 263 } /* plugin_unregister_all */
 264
 265 /*
 266  * private types
 267  */
 268
 269 static int
 270 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 271 {
 272         ctx_t *ctx = CTX(obj);
 273
 274         assert(ctx);
 275
 276         ctx->public = plugin_default_ctx;
 277         ctx->info = plugin_default_info;
 278         ctx->handle = NULL;
 279         ctx->use_cnt = 1;
 280         return 0;
 281 } /* ctx_init */
 282
 283 static void
 284 ctx_destroy(sdb_object_t *obj)
 285 {
 286         ctx_t *ctx = CTX(obj);
 287
 288         if (ctx->handle) {
 289                 const char *err;
 290
 291                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s",
 292                                 ctx->info.plugin_name);
 293
 294                 lt_dlerror();
 295                 lt_dlclose(ctx->handle);
 296                 if ((err = lt_dlerror()))
 297                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload module %s: %s",
 298                                         ctx->info.plugin_name, err);
 299         }
 300
 301         plugin_info_clear(&ctx->info);
 302 } /* ctx_destroy */
 303
 304 static sdb_type_t ctx_type = {
 305         sizeof(ctx_t),
 306
 307         ctx_init,
 308         ctx_destroy
 309 };
 310
 311 static ctx_t *
 312 ctx_get(void)
 313 {
 314         if (! plugin_ctx_key_initialized)
 315                 ctx_key_init();
 316         return pthread_getspecific(plugin_ctx_key);
 317 } /* ctx_get */
 318
 319 static ctx_t *
 320 ctx_set(ctx_t *new)
 321 {
 322         ctx_t *old;
 323
 324         if (! plugin_ctx_key_initialized)
 325                 ctx_key_init();
 326
 327         old = pthread_getspecific(plugin_ctx_key);
 328         if (old)
 329                 sdb_object_deref(SDB_OBJ(old));
 330         if (new)
 331                 sdb_object_ref(SDB_OBJ(new));
 332         pthread_setspecific(plugin_ctx_key, new);
 333         return old;
 334 } /* ctx_set */
 335
 336 static ctx_t *
 337 ctx_create(const char *name)
 338 {
 339         ctx_t *ctx;
 340
 341         ctx = CTX(sdb_object_create(name, ctx_type));
 342         if (! ctx)
 343                 return NULL;
 344
 345         if (! plugin_ctx_key_initialized)
 346                 ctx_key_init();
 347         ctx_set(ctx);
 348         return ctx;
 349 } /* ctx_create */
 350
 351 static int
 352 plugin_cb_init(sdb_object_t *obj, va_list ap)
 353 {
 354         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 355         const char   *type = va_arg(ap, const char *);
 356         void     *callback = va_arg(ap, void *);
 357         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 358
 359         assert(list);
 360         assert(type);
 361         assert(obj);
 362
 363         if (sdb_llist_search_by_name(*list, obj->name)) {
 364                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 365                                 "has already been registered. Ignoring newly "
 366                                 "registered version.", type, obj->name);
 367                 return -1;
 368         }
 369
 370         /* cb_ctx may be NULL if the plugin was not registered by a plugin */
 371
 372         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 373         SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
 374         sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 375
 376         sdb_object_ref(ud);
 377         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 378         return 0;
 379 } /* plugin_cb_init */
 380
 381 static void
 382 plugin_cb_destroy(sdb_object_t *obj)
 383 {
 384         assert(obj);
 385         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 386         sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 387 } /* plugin_cb_destroy */
 388
 389 static sdb_type_t sdb_plugin_cb_type = {
 390         sizeof(sdb_plugin_cb_t),
 391
 392         plugin_cb_init,
 393         plugin_cb_destroy
 394 };
 395
 396 static sdb_type_t sdb_plugin_collector_cb_type = {
 397         sizeof(sdb_plugin_collector_cb_t),
 398
 399         plugin_cb_init,
 400         plugin_cb_destroy
 401 };
 402
 403 static int
 404 module_init(const char *name, lt_dlhandle lh, sdb_plugin_info_t *info)
 405 {
 406         int (*mod_init)(sdb_plugin_info_t *);
 407         int status;
 408
 409         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 410         if (! mod_init) {
 411                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 412                                 "could not find symbol 'sdb_module_init'", name);
 413                 return -1;
 414         }
 415
 416         status = mod_init(info);
 417         if (status) {
 418                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 419                                 "module '%s'", name);
 420                 plugin_unregister_by_name(name);
 421                 return -1;
 422         }
 423         return 0;
 424 } /* module_init */
 425
 426 static int
 427 module_load(const char *basedir, const char *name,
 428                 const sdb_plugin_ctx_t *plugin_ctx)
 429 {
 430         char  base_name[name ? strlen(name) + 1 : 1];
 431         const char *name_ptr;
 432         char *tmp;
 433
 434         char filename[1024];
 435         lt_dlhandle lh;
 436
 437         ctx_t *ctx;
 438
 439         int status;
 440
 441         assert(name);
 442
 443         base_name[0] = '\0';
 444         name_ptr = name;
 445
 446         while ((tmp = strstr(name_ptr, "::"))) {
 447                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 448                 strcat(base_name, "/");
 449                 name_ptr = tmp + strlen("::");
 450         }
 451         strcat(base_name, name_ptr);
 452
 453         if (! basedir)
 454                 basedir = PKGLIBDIR;
 455
 456         snprintf(filename, sizeof(filename), "%s/%s.so", basedir, base_name);
 457         filename[sizeof(filename) - 1] = '\0';
 458
 459         if (access(filename, R_OK)) {
 460                 char errbuf[1024];
 461                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 462                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 463                 return -1;
 464         }
 465
 466         lt_dlinit();
 467         lt_dlerror();
 468
 469         lh = lt_dlopen(filename);
 470         if (! lh) {
 471                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 472                                 "The most common cause for this problem are missing "
 473                                 "dependencies.\n", name, lt_dlerror());
 474                 return -1;
 475         }
 476
 477         if (ctx_get())
 478                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 479
 480         ctx = ctx_create(name);
 481         if (! ctx) {
 482                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 483                 return -1;
 484         }
 485
 486         ctx->info.plugin_name = strdup(name);
 487         ctx->info.filename = strdup(filename);
 488         ctx->handle = lh;
 489
 490         if (plugin_ctx)
 491                 ctx->public = *plugin_ctx;
 492
 493         if ((status = module_init(name, lh, &ctx->info))) {
 494                 sdb_object_deref(SDB_OBJ(ctx));
 495                 return status;
 496         }
 497
 498         /* compare minor version */
 499         if ((ctx->info.version < 0)
 500                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 501                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 502                                 "plugin '%s' (%i.%i.%i) does not match our version "
 503                                 "(%i.%i.%i); this might cause problems",
 504                                 name, SDB_VERSION_DECODE(ctx->info.version),
 505                                 SDB_VERSION_DECODE(SDB_VERSION));
 506
 507         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 508
 509         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 510                         "plugin %s v%i (%s)", ctx->info.plugin_name,
 511                         ctx->info.plugin_version,
 512                         INFO_GET(&ctx->info, description));
 513         sdb_log(SDB_LOG_INFO, "core: Plugin %s: %s, License: %s",
 514                         ctx->info.plugin_name,
 515                         INFO_GET(&ctx->info, copyright),
 516                         INFO_GET(&ctx->info, license));
 517
 518         /* any registered callbacks took ownership of the context */
 519         sdb_object_deref(SDB_OBJ(ctx));
 520
 521         /* reset */
 522         ctx_set(NULL);
 523         return 0;
 524 } /* module_load */
 525
 526 static char *
 527 plugin_get_name(const char *name, char *buf, size_t bufsize)
 528 {
 529         ctx_t *ctx = ctx_get();
 530
 531         if (ctx)
 532                 snprintf(buf, bufsize, "%s::%s", ctx->info.plugin_name, name);
 533         else
 534                 snprintf(buf, bufsize, "core::%s", name);
 535         return buf;
 536 } /* plugin_get_name */
 537
 538 static int
 539 plugin_add_callback(sdb_llist_t **list, const char *type,
 540                 const char *name, void *callback, sdb_object_t *user_data)
 541 {
 542         sdb_object_t *obj;
 543
 544         if ((! name) || (! callback))
 545                 return -1;
 546
 547         assert(list);
 548
 549         if (! *list)
 550                 *list = sdb_llist_create();
 551         if (! *list)
 552                 return -1;
 553
 554         obj = sdb_object_create(name, sdb_plugin_cb_type,
 555                         list, type, callback, user_data);
 556         if (! obj)
 557                 return -1;
 558
 559         if (sdb_llist_append(*list, obj)) {
 560                 sdb_object_deref(obj);
 561                 return -1;
 562         }
 563
 564         /* pass control to the list */
 565         sdb_object_deref(obj);
 566
 567         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 568                         type, name);
 569         return 0;
 570 } /* plugin_add_callback */
 571
 572 /*
 573  * public API
 574  */
 575
 576 int
 577 sdb_plugin_load(const char *basedir, const char *name,
 578                 const sdb_plugin_ctx_t *plugin_ctx)
 579 {
 580         ctx_t *ctx;
 581
 582         int status;
 583
 584         if ((! name) || (! *name))
 585                 return -1;
 586
 587         if (! all_plugins) {
 588                 if (! (all_plugins = sdb_llist_create())) {
 589                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 590                                         "internal error while creating linked list", name);
 591                         return -1;
 592                 }
 593         }
 594
 595         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 596         if (ctx) {
 597                 /* plugin already loaded */
 598                 if (! ctx->use_cnt) {
 599                         /* reloading plugin */
 600                         ctx_t *old_ctx = ctx_set(ctx);
 601
 602                         status = module_init(ctx->info.plugin_name, ctx->handle, NULL);
 603                         if (status)
 604                                 return status;
 605
 606                         sdb_log(SDB_LOG_INFO, "core: Successfully reloaded plugin "
 607                                         "'%s' (%s)", ctx->info.plugin_name,
 608                                         INFO_GET(&ctx->info, description));
 609                         ctx_set(old_ctx);
 610                 }
 611                 ++ctx->use_cnt;
 612                 return 0;
 613         }
 614
 615         return module_load(basedir, name, plugin_ctx);
 616 } /* sdb_plugin_load */
 617
 618 int
 619 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 620 {
 621         va_list ap;
 622
 623         if (! info)
 624                 return -1;
 625
 626         va_start(ap, type);
 627
 628         switch (type) {
 629                 case SDB_PLUGIN_INFO_DESC:
 630                         {
 631                                 char *desc = va_arg(ap, char *);
 632                                 if (desc) {
 633                                         if (info->description)
 634                                                 free(info->description);
 635                                         info->description = strdup(desc);
 636                                 }
 637                         }
 638                         break;
 639                 case SDB_PLUGIN_INFO_COPYRIGHT:
 640                         {
 641                                 char *copyright = va_arg(ap, char *);
 642                                 if (copyright)
 643                                         info->copyright = strdup(copyright);
 644                         }
 645                         break;
 646                 case SDB_PLUGIN_INFO_LICENSE:
 647                         {
 648                                 char *license = va_arg(ap, char *);
 649                                 if (license) {
 650                                         if (info->license)
 651                                                 free(info->license);
 652                                         info->license = strdup(license);
 653                                 }
 654                         }
 655                         break;
 656                 case SDB_PLUGIN_INFO_VERSION:
 657                         {
 658                                 int version = va_arg(ap, int);
 659                                 info->version = version;
 660                         }
 661                         break;
 662                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 663                         {
 664                                 int version = va_arg(ap, int);
 665                                 info->plugin_version = version;
 666                         }
 667                         break;
 668                 default:
 669                         va_end(ap);
 670                         return -1;
 671         }
 672
 673         va_end(ap);
 674         return 0;
 675 } /* sdb_plugin_set_info */
 676
 677 int
 678 sdb_plugin_register_config(sdb_plugin_config_cb callback)
 679 {
 680         ctx_t *ctx = ctx_get();
 681
 682         if (! ctx) {
 683                 sdb_log(SDB_LOG_ERR, "core: Invalid attempt to register a "
 684                                 "config callback from outside a plugin");
 685                 return -1;
 686         }
 687         return plugin_add_callback(&config_list, "init", ctx->info.plugin_name,
 688                         (void *)callback, NULL);
 689 } /* sdb_plugin_register_config */
 690
 691 int
 692 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 693                 sdb_object_t *user_data)
 694 {
 695         char cb_name[1024];
 696         return plugin_add_callback(&init_list, "init",
 697                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 698                         (void *)callback, user_data);
 699 } /* sdb_plugin_register_init */
 700
 701 int
 702 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 703                 sdb_object_t *user_data)
 704 {
 705         char cb_name[1024];
 706         return plugin_add_callback(&shutdown_list, "shutdown",
 707                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 708                         (void *)callback, user_data);
 709 } /* sdb_plugin_register_shutdown */
 710
 711 int
 712 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 713                 sdb_object_t *user_data)
 714 {
 715         char cb_name[1024];
 716         return plugin_add_callback(&log_list, "log",
 717                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 718                         callback, user_data);
 719 } /* sdb_plugin_register_log */
 720
 721 int
 722 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 723                 sdb_object_t *user_data)
 724 {
 725         char cb_name[1024];
 726         return plugin_add_callback(&cname_list, "cname",
 727                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 728                         callback, user_data);
 729 } /* sdb_plugin_register_cname */
 730
 731 int
 732 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 733                 const sdb_time_t *interval, sdb_object_t *user_data)
 734 {
 735         char cb_name[1024];
 736         sdb_object_t *obj;
 737
 738         if ((! name) || (! callback))
 739                 return -1;
 740
 741         if (! collector_list)
 742                 collector_list = sdb_llist_create();
 743         if (! collector_list)
 744                 return -1;
 745
 746         plugin_get_name(name, cb_name, sizeof(cb_name));
 747
 748         obj = sdb_object_create(cb_name, sdb_plugin_collector_cb_type,
 749                         &collector_list, "collector", callback, user_data);
 750         if (! obj)
 751                 return -1;
 752
 753         if (interval)
 754                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 755         else {
 756                 ctx_t *ctx = ctx_get();
 757
 758                 if (! ctx) {
 759                         sdb_log(SDB_LOG_ERR, "core: Cannot determine interval "
 760                                         "for collector %s; none specified and no plugin "
 761                                         "context found", cb_name);
 762                         return -1;
 763                 }
 764
 765                 SDB_PLUGIN_CCB(obj)->ccb_interval = ctx->public.interval;
 766         }
 767
 768         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 769                 char errbuf[1024];
 770                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 771                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 772                 sdb_object_deref(obj);
 773                 return -1;
 774         }
 775
 776         if (sdb_llist_insert_sorted(collector_list, obj,
 777                                 plugin_cmp_next_update)) {
 778                 sdb_object_deref(obj);
 779                 return -1;
 780         }
 781
 782         /* pass control to the list */
 783         sdb_object_deref(obj);
 784
 785         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 786                         "(interval = %.3fs).", cb_name,
 787                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 788         return 0;
 789 } /* sdb_plugin_register_collector */
 790
 791 int
 792 sdb_plugin_register_ts_fetcher(const char *name,
 793                 sdb_plugin_fetch_ts_cb callback, sdb_object_t *user_data)
 794 {
 795         return plugin_add_callback(&ts_fetcher_list, "time-series fetcher",
 796                         name, callback, user_data);
 797 } /* sdb_plugin_register_ts_fetcher */
 798
 799 sdb_plugin_ctx_t
 800 sdb_plugin_get_ctx(void)
 801 {
 802         ctx_t *c;
 803
 804         c = ctx_get();
 805         if (! c) {
 806                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 807                                 "context outside a plugin");
 808                 return plugin_default_ctx;
 809         }
 810         return c->public;
 811 } /* sdb_plugin_get_ctx */
 812
 813 int
 814 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 815 {
 816         ctx_t *c;
 817
 818         c = ctx_get();
 819         if (! c) {
 820                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
 821                                 "context outside a plugin");
 822                 return -1;
 823         }
 824
 825         if (old)
 826                 *old = c->public;
 827         c->public = ctx;
 828         return 0;
 829 } /* sdb_plugin_set_ctx */
 830
 831 const sdb_plugin_info_t *
 832 sdb_plugin_current(void)
 833 {
 834         ctx_t *ctx = ctx_get();
 835
 836         if (! ctx)
 837                 return NULL;
 838         return &ctx->info;
 839 } /* sdb_plugin_current */
 840
 841 int
 842 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 843 {
 844         sdb_plugin_cb_t *plugin;
 845         sdb_plugin_config_cb callback;
 846
 847         ctx_t *old_ctx;
 848
 849         int status;
 850
 851         if ((! name) || (! ci))
 852                 return -1;
 853
 854         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(config_list, name));
 855         if (! plugin) {
 856                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 857                 if (! ctx)
 858                         sdb_log(SDB_LOG_ERR, "core: Cannot configure unknown "
 859                                         "plugin '%s'. Missing 'LoadPlugin \"%s\"'?",
 860                                         name, name);
 861                 else
 862                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
 863                                         "a config callback.", name);
 864                 errno = ENOENT;
 865                 return -1;
 866         }
 867
 868         old_ctx = ctx_set(plugin->cb_ctx);
 869         callback = (sdb_plugin_config_cb)plugin->cb_callback;
 870         status = callback(ci);
 871         ctx_set(old_ctx);
 872         return status;
 873 } /* sdb_plugin_configure */
 874
 875 int
 876 sdb_plugin_reconfigure_init(void)
 877 {
 878         sdb_llist_iter_t *iter;
 879
 880         iter = sdb_llist_get_iter(config_list);
 881         if (config_list && (! iter))
 882                 return -1;
 883
 884         /* deconfigure all plugins */
 885         while (sdb_llist_iter_has_next(iter)) {
 886                 sdb_plugin_cb_t *plugin;
 887                 sdb_plugin_config_cb callback;
 888                 ctx_t *old_ctx;
 889
 890                 plugin = SDB_PLUGIN_CB(sdb_llist_iter_get_next(iter));
 891                 old_ctx = ctx_set(plugin->cb_ctx);
 892                 callback = (sdb_plugin_config_cb)plugin->cb_callback;
 893                 callback(NULL);
 894                 ctx_set(old_ctx);
 895         }
 896         sdb_llist_iter_destroy(iter);
 897
 898         iter = sdb_llist_get_iter(all_plugins);
 899         if (all_plugins && (! iter))
 900                 return -1;
 901
 902         /* record all plugins as being unused */
 903         while (sdb_llist_iter_has_next(iter))
 904                 CTX(sdb_llist_iter_get_next(iter))->use_cnt = 0;
 905         sdb_llist_iter_destroy(iter);
 906
 907         plugin_unregister_all();
 908         return 0;
 909 } /* sdb_plugin_reconfigure_init */
 910
 911 int
 912 sdb_plugin_reconfigure_finish(void)
 913 {
 914         sdb_llist_iter_t *iter;
 915
 916         iter = sdb_llist_get_iter(all_plugins);
 917         if (all_plugins && (! iter))
 918                 return -1;
 919
 920         while (sdb_llist_iter_has_next(iter)) {
 921                 ctx_t *ctx = CTX(sdb_llist_iter_get_next(iter));
 922                 if (ctx->use_cnt)
 923                         continue;
 924
 925                 sdb_log(SDB_LOG_INFO, "core: Module %s no longer in use",
 926                                 ctx->info.plugin_name);
 927                 sdb_llist_iter_remove_current(iter);
 928                 plugin_unregister_by_name(ctx->info.plugin_name);
 929                 sdb_object_deref(SDB_OBJ(ctx));
 930         }
 931         sdb_llist_iter_destroy(iter);
 932         return 0;
 933 } /* sdb_plugin_reconfigure_finish */
 934
 935 int
 936 sdb_plugin_init_all(void)
 937 {
 938         sdb_llist_iter_t *iter;
 939         int ret = 0;
 940
 941         iter = sdb_llist_get_iter(init_list);
 942         while (sdb_llist_iter_has_next(iter)) {
 943                 sdb_plugin_cb_t *cb;
 944                 sdb_plugin_init_cb callback;
 945                 ctx_t *old_ctx;
 946
 947                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 948                 assert(obj);
 949                 cb = SDB_PLUGIN_CB(obj);
 950
 951                 callback = (sdb_plugin_init_cb)cb->cb_callback;
 952
 953                 old_ctx = ctx_set(cb->cb_ctx);
 954                 if (callback(cb->cb_user_data)) {
 955                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
 956                                         "'%s'. Unregistering all callbacks.", obj->name);
 957                         ctx_set(old_ctx);
 958                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
 959                         ++ret;
 960                 }
 961                 else
 962                         ctx_set(old_ctx);
 963         }
 964         sdb_llist_iter_destroy(iter);
 965         return ret;
 966 } /* sdb_plugin_init_all */
 967
 968 int
 969 sdb_plugin_shutdown_all(void)
 970 {
 971         sdb_llist_iter_t *iter;
 972         int ret = 0;
 973
 974         iter = sdb_llist_get_iter(shutdown_list);
 975         while (sdb_llist_iter_has_next(iter)) {
 976                 sdb_plugin_cb_t *cb;
 977                 sdb_plugin_shutdown_cb callback;
 978                 ctx_t *old_ctx;
 979
 980                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 981                 assert(obj);
 982                 cb = SDB_PLUGIN_CB(obj);
 983
 984                 callback = (sdb_plugin_shutdown_cb)cb->cb_callback;
 985
 986                 old_ctx = ctx_set(cb->cb_ctx);
 987                 if (callback(cb->cb_user_data)) {
 988                         sdb_log(SDB_LOG_ERR, "core: Failed to shutdown plugin '%s'.",
 989                                         obj->name);
 990                         ++ret;
 991                 }
 992                 ctx_set(old_ctx);
 993         }
 994         sdb_llist_iter_destroy(iter);
 995         return ret;
 996 } /* sdb_plugin_shutdown_all */
 997
 998 int
 999 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
1000 {
1001         if (! collector_list) {
1002                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
1003                                 "Quiting main loop.");
1004                 return -1;
1005         }
1006
1007         if (! loop)
1008                 return -1;
1009
1010         while (loop->do_loop) {
1011                 sdb_plugin_collector_cb callback;
1012                 ctx_t *old_ctx;
1013
1014                 sdb_time_t interval, now;
1015
1016                 sdb_object_t *obj = sdb_llist_shift(collector_list);
1017                 if (! obj)
1018                         return -1;
1019
1020                 callback = (sdb_plugin_collector_cb)SDB_PLUGIN_CCB(obj)->ccb_callback;
1021
1022                 if (! (now = sdb_gettime())) {
1023                         char errbuf[1024];
1024                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1025                                         "time in collector main loop: %s",
1026                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1027                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1028                 }
1029
1030                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1031                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
1032
1033                         errno = 0;
1034                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
1035                                 if (errno != EINTR) {
1036                                         char errbuf[1024];
1037                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
1038                                                         "in collector main loop: %s",
1039                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1040                                         sdb_llist_insert_sorted(collector_list, obj,
1041                                                         plugin_cmp_next_update);
1042                                         sdb_object_deref(obj);
1043                                         return -1;
1044                                 }
1045                                 errno = 0;
1046                         }
1047
1048                         if (! loop->do_loop) {
1049                                 /* put back; don't worry about errors */
1050                                 sdb_llist_insert_sorted(collector_list, obj,
1051                                                 plugin_cmp_next_update);
1052                                 sdb_object_deref(obj);
1053                                 return 0;
1054                         }
1055                 }
1056
1057                 old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
1058                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
1059                         /* XXX */
1060                 }
1061                 ctx_set(old_ctx);
1062
1063                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
1064                 if (! interval)
1065                         interval = loop->default_interval;
1066                 if (! interval) {
1067                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
1068                                         "for plugin '%s'; skipping any further "
1069                                         "iterations.", obj->name);
1070                         sdb_object_deref(obj);
1071                         continue;
1072                 }
1073
1074                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
1075
1076                 if (! (now = sdb_gettime())) {
1077                         char errbuf[1024];
1078                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1079                                         "time in collector main loop: %s",
1080                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1081                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
1082                 }
1083
1084                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
1085                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
1086                                         "long; skipping iterations to keep up.",
1087                                         obj->name);
1088                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
1089                 }
1090
1091                 if (sdb_llist_insert_sorted(collector_list, obj,
1092                                         plugin_cmp_next_update)) {
1093                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
1094                                         "plugin '%s' into collector list. Unable to further "
1095                                         "use the plugin.",
1096                                         obj->name);
1097                         sdb_object_deref(obj);
1098                         return -1;
1099                 }
1100
1101                 /* pass control back to the list */
1102                 sdb_object_deref(obj);
1103         }
1104         return 0;
1105 } /* sdb_plugin_read_loop */
1106
1107 char *
1108 sdb_plugin_cname(char *hostname)
1109 {
1110         sdb_llist_iter_t *iter;
1111
1112         if (! hostname)
1113                 return NULL;
1114
1115         if (! cname_list)
1116                 return hostname;
1117
1118         iter = sdb_llist_get_iter(cname_list);
1119         while (sdb_llist_iter_has_next(iter)) {
1120                 sdb_plugin_cname_cb callback;
1121                 char *cname;
1122
1123                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1124                 assert(obj);
1125
1126                 callback = (sdb_plugin_cname_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1127                 cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data);
1128                 if (cname) {
1129                         free(hostname);
1130                         hostname = cname;
1131                 }
1132                 /* else: don't change hostname */
1133         }
1134         sdb_llist_iter_destroy(iter);
1135         return hostname;
1136 } /* sdb_plugin_cname */
1137
1138 int
1139 sdb_plugin_log(int prio, const char *msg)
1140 {
1141         sdb_llist_iter_t *iter;
1142         int ret = -1;
1143
1144         bool logged = 0;
1145
1146         if (! msg)
1147                 return 0;
1148
1149         iter = sdb_llist_get_iter(log_list);
1150         while (sdb_llist_iter_has_next(iter)) {
1151                 sdb_plugin_log_cb callback;
1152                 int tmp;
1153
1154                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1155                 assert(obj);
1156
1157                 callback = (sdb_plugin_log_cb)SDB_PLUGIN_CB(obj)->cb_callback;
1158                 tmp = callback(prio, msg, SDB_PLUGIN_CB(obj)->cb_user_data);
1159                 if (tmp > ret)
1160                         ret = tmp;
1161
1162                 if (SDB_PLUGIN_CB(obj)->cb_ctx)
1163                         logged = 1;
1164                 /* else: this is an internally registered callback */
1165         }
1166         sdb_llist_iter_destroy(iter);
1167
1168         if (! logged)
1169                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
1170         return ret;
1171 } /* sdb_plugin_log */
1172
1173 int
1174 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
1175 {
1176         sdb_strbuf_t *buf;
1177         int ret;
1178
1179         if (! fmt)
1180                 return 0;
1181
1182         buf = sdb_strbuf_create(64);
1183         if (! buf) {
1184                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
1185                 ret += vfprintf(stderr, fmt, ap);
1186                 return ret;
1187         }
1188
1189         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1190                 sdb_strbuf_destroy(buf);
1191                 return -1;
1192         }
1193
1194         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1195         sdb_strbuf_destroy(buf);
1196         return ret;
1197 } /* sdb_plugin_vlogf */
1198
1199 int
1200 sdb_plugin_logf(int prio, const char *fmt, ...)
1201 {
1202         va_list ap;
1203         int ret;
1204
1205         if (! fmt)
1206                 return 0;
1207
1208         va_start(ap, fmt);
1209         ret = sdb_plugin_vlogf(prio, fmt, ap);
1210         va_end(ap);
1211         return ret;
1212 } /* sdb_plugin_logf */
1213
1214 sdb_timeseries_t *
1215 sdb_plugin_fetch_timeseries(const char *type, const char *id,
1216                 sdb_timeseries_opts_t *opts)
1217 {
1218         sdb_plugin_cb_t *plugin;
1219         sdb_plugin_fetch_ts_cb callback;
1220         sdb_timeseries_t *ts;
1221
1222         ctx_t *old_ctx;
1223
1224         if ((! type) || (! id) || (! opts))
1225                 return NULL;
1226
1227         plugin = SDB_PLUGIN_CB(sdb_llist_search_by_name(ts_fetcher_list, type));
1228         if (! plugin) {
1229                 sdb_log(SDB_LOG_ERR, "core: Cannot fetch time-series of type %s: "
1230                                 "no such plugin loaded", type);
1231                 errno = ENOENT;
1232                 return NULL;
1233         }
1234
1235         old_ctx = ctx_set(plugin->cb_ctx);
1236         callback = (sdb_plugin_fetch_ts_cb)plugin->cb_callback;
1237         ts = callback(id, opts, plugin->cb_user_data);
1238         ctx_set(old_ctx);
1239         return ts;
1240 } /* sdb_plugin_fetch_timeseries */
1241
1242 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1243