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