lib/plugin/plugin.c

   1 /*
   2  * plugin.c
   3  *
   4  * Babeltrace Plugin (generic)
   5  *
   6  * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
   8  *
   9  * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  27  * SOFTWARE.
  28  */
  29
  30 #define BT_LOG_TAG "PLUGIN"
  31 #include <babeltrace/lib-logging-internal.h>
  32
  33 #include <babeltrace/babeltrace-internal.h>
  34 #include <babeltrace/compiler-internal.h>
  35 #include <babeltrace/ref.h>
  36 #include <babeltrace/common-internal.h>
  37 #include <babeltrace/plugin/plugin-internal.h>
  38 #include <babeltrace/plugin/plugin-so-internal.h>
  39 #include <babeltrace/graph/component-class.h>
  40 #include <babeltrace/graph/component-class-internal.h>
  41 #include <babeltrace/types.h>
  42 #include <glib.h>
  43 #include <unistd.h>
  44 #include <stdlib.h>
  45 #include <stdint.h>
  46 #include <inttypes.h>
  47 #include <sys/stat.h>
  48 #include <ftw.h>
  49 #include <pthread.h>
  50
  51 #define PYTHON_PLUGIN_PROVIDER_FILENAME "libbabeltrace-python-plugin-provider." G_MODULE_SUFFIX
  52 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME bt_plugin_python_create_all_from_file
  53 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR     TOSTRING(PYTHON_PLUGIN_PROVIDER_SYM_NAME)
  54
  55 #define APPEND_ALL_FROM_DIR_NFDOPEN_MAX 8
  56
  57 #ifdef BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT
  58 #include <babeltrace/plugin/python-plugin-provider-internal.h>
  59
  60 static
  61 struct bt_plugin_set *(*bt_plugin_python_create_all_from_file_sym)(const char *path) =
  62         bt_plugin_python_create_all_from_file;
  63 #else /* BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT */
  64 static GModule *python_plugin_provider_module;
  65 static
  66 struct bt_plugin_set *(*bt_plugin_python_create_all_from_file_sym)(const char *path);
  67
  68 __attribute__((constructor)) static
  69 void init_python_plugin_provider(void) {
  70         BT_LOGD_STR("Loading Python plugin provider module.");
  71         python_plugin_provider_module =
  72                 g_module_open(PYTHON_PLUGIN_PROVIDER_FILENAME,
  73                         G_MODULE_BIND_LOCAL);
  74         if (!python_plugin_provider_module) {
  75                 BT_LOGI("Cannot find `%s`: continuing without Python plugin support.",
  76                         PYTHON_PLUGIN_PROVIDER_FILENAME);
  77                 return;
  78         }
  79
  80         if (!g_module_symbol(python_plugin_provider_module,
  81                         PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR,
  82                         (gpointer) &bt_plugin_python_create_all_from_file_sym)) {
  83                 BT_LOGI("Cannot find the Python plugin provider loading symbol: continuing without Python plugin support: "
  84                         "file=\"%s\", symbol=\"%s\"",
  85                         PYTHON_PLUGIN_PROVIDER_FILENAME,
  86                         PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR);
  87                 return;
  88         }
  89
  90         BT_LOGI("Loaded Python plugin provider module: addr=%p",
  91                 python_plugin_provider_module);
  92 }
  93
  94 __attribute__((destructor)) static
  95 void fini_python_plugin_provider(void) {
  96         if (python_plugin_provider_module) {
  97                 BT_LOGD("Unloading Python plugin provider module.");
  98
  99                 if (!g_module_close(python_plugin_provider_module)) {
 100                         BT_LOGE("Failed to close the Python plugin provider module: %s.",
 101                                 g_module_error());
 102                 }
 103
 104                 python_plugin_provider_module = NULL;
 105         }
 106 }
 107 #endif
 108
 109 extern
 110 int64_t bt_plugin_set_get_plugin_count(struct bt_plugin_set *plugin_set)
 111 {
 112         int64_t count = -1;
 113
 114         if (!plugin_set) {
 115                 BT_LOGW_STR("Invalid parameter: plugin set is NULL.");
 116                 goto end;
 117         }
 118
 119         count = (int64_t) plugin_set->plugins->len;
 120
 121 end:
 122         return count;
 123 }
 124
 125 extern
 126 struct bt_plugin *bt_plugin_set_get_plugin(struct bt_plugin_set *plugin_set,
 127                 uint64_t index)
 128 {
 129         struct bt_plugin *plugin = NULL;
 130
 131         if (!plugin_set) {
 132                 BT_LOGW_STR("Invalid parameter: plugin set is NULL.");
 133                 goto end;
 134         }
 135
 136         if (index >= plugin_set->plugins->len) {
 137                 BT_LOGW("Invalid parameter: index is out of bounds: "
 138                         "addr=%p, index=%" PRIu64 ", count=%u",
 139                         plugin_set, index, plugin_set->plugins->len);
 140                 goto end;
 141         }
 142
 143         plugin = bt_get(g_ptr_array_index(plugin_set->plugins, index));
 144
 145 end:
 146         return plugin;
 147 }
 148
 149 struct bt_plugin_set *bt_plugin_create_all_from_static(void)
 150 {
 151         /* bt_plugin_so_create_all_from_static() logs errors */
 152         return bt_plugin_so_create_all_from_static();
 153 }
 154
 155 struct bt_plugin_set *bt_plugin_create_all_from_file(const char *path)
 156 {
 157         struct bt_plugin_set *plugin_set = NULL;
 158
 159         if (!path) {
 160                 BT_LOGW_STR("Invalid parameter: path is NULL.");
 161                 goto end;
 162         }
 163
 164         BT_LOGD("Creating plugins from file: path=\"%s\"", path);
 165
 166         /* Try shared object plugins */
 167         plugin_set = bt_plugin_so_create_all_from_file(path);
 168         if (plugin_set) {
 169                 goto end;
 170         }
 171
 172         /* Try Python plugins if support is available */
 173         if (bt_plugin_python_create_all_from_file_sym) {
 174                 plugin_set = bt_plugin_python_create_all_from_file_sym(path);
 175                 if (plugin_set) {
 176                         goto end;
 177                 }
 178         }
 179
 180 end:
 181         if (plugin_set) {
 182                 BT_LOGD("Created %u plugins from file: "
 183                         "path=\"%s\", count=%u, plugin-set-addr=%p",
 184                         plugin_set->plugins->len, path,
 185                         plugin_set->plugins->len, plugin_set);
 186         } else {
 187                 BT_LOGD("Found no plugins in file: path=\"%s\"", path);
 188         }
 189
 190         return plugin_set;
 191 }
 192
 193 static void destroy_gstring(void *data)
 194 {
 195         g_string_free(data, TRUE);
 196 }
 197
 198 struct bt_plugin *bt_plugin_find(const char *plugin_name)
 199 {
 200         const char *system_plugin_dir;
 201         char *home_plugin_dir = NULL;
 202         const char *envvar;
 203         struct bt_plugin *plugin = NULL;
 204         struct bt_plugin_set *plugin_set = NULL;
 205         GPtrArray *dirs = NULL;
 206         int ret;
 207         size_t i, j;
 208
 209         if (!plugin_name) {
 210                 BT_LOGW_STR("Invalid parameter: plugin name is NULL.");
 211                 goto end;
 212         }
 213
 214         BT_LOGD("Finding named plugin in standard directories and built-in plugins: "
 215                 "name=\"%s\"", plugin_name);
 216         dirs = g_ptr_array_new_with_free_func((GDestroyNotify) destroy_gstring);
 217         if (!dirs) {
 218                 BT_LOGE_STR("Failed to allocate a GPtrArray.");
 219                 goto end;
 220         }
 221
 222         /*
 223          * Search order is:
 224          *
 225          * 1. BABELTRACE_PLUGIN_PATH environment variable
 226          *    (colon-separated list of directories)
 227          * 2. ~/.local/lib/babeltrace/plugins
 228          * 3. Default system directory for Babeltrace plugins, usually
 229          *    /usr/lib/babeltrace/plugins or
 230          *    /usr/local/lib/babeltrace/plugins if installed
 231          *    locally
 232          * 4. Built-in plugins (static)
 233          *
 234          * Directories are searched non-recursively.
 235          */
 236         envvar = getenv("BABELTRACE_PLUGIN_PATH");
 237         if (envvar) {
 238                 ret = bt_common_append_plugin_path_dirs(envvar, dirs);
 239                 if (ret) {
 240                         BT_LOGE_STR("Failed to append plugin path to array of directories.");
 241                         goto end;
 242                 }
 243         }
 244
 245         home_plugin_dir = bt_common_get_home_plugin_path();
 246         if (home_plugin_dir) {
 247                 GString *home_plugin_dir_str =
 248                         g_string_new(home_plugin_dir);
 249
 250                 if (!home_plugin_dir_str) {
 251                         BT_LOGE_STR("Failed to allocate a GString.");
 252                         goto end;
 253                 }
 254
 255                 g_ptr_array_add(dirs, home_plugin_dir_str);
 256         }
 257
 258         system_plugin_dir = bt_common_get_system_plugin_path();
 259         if (system_plugin_dir) {
 260                 GString *system_plugin_dir_str =
 261                         g_string_new(system_plugin_dir);
 262
 263                 if (!system_plugin_dir_str) {
 264                         BT_LOGE_STR("Failed to allocate a GString.");
 265                         goto end;
 266                 }
 267
 268                 g_ptr_array_add(dirs, system_plugin_dir_str);
 269         }
 270
 271         for (i = 0; i < dirs->len; i++) {
 272                 GString *dir = g_ptr_array_index(dirs, i);
 273
 274                 BT_PUT(plugin_set);
 275
 276                 /*
 277                  * Skip this if the directory does not exist because
 278                  * bt_plugin_create_all_from_dir() would log a warning.
 279                  */
 280                 if (!g_file_test(dir->str, G_FILE_TEST_IS_DIR)) {
 281                         BT_LOGV("Skipping nonexistent directory path: "
 282                                 "path=\"%s\"", dir->str);
 283                         continue;
 284                 }
 285
 286                 /* bt_plugin_create_all_from_dir() logs details/errors */
 287                 plugin_set = bt_plugin_create_all_from_dir(dir->str, BT_FALSE);
 288                 if (!plugin_set) {
 289                         BT_LOGD("No plugins found in directory: path=\"%s\"",
 290                                 dir->str);
 291                         continue;
 292                 }
 293
 294                 for (j = 0; j < plugin_set->plugins->len; j++) {
 295                         struct bt_plugin *candidate_plugin =
 296                                 g_ptr_array_index(plugin_set->plugins, j);
 297
 298                         if (strcmp(bt_plugin_get_name(candidate_plugin),
 299                                         plugin_name) == 0) {
 300                                 BT_LOGD("Plugin found in directory: name=\"%s\", path=\"%s\"",
 301                                         plugin_name, dir->str);
 302                                 plugin = bt_get(candidate_plugin);
 303                                 goto end;
 304                         }
 305                 }
 306
 307                 BT_LOGD("Plugin not found in directory: name=\"%s\", path=\"%s\"",
 308                         plugin_name, dir->str);
 309         }
 310
 311         bt_put(plugin_set);
 312         plugin_set = bt_plugin_create_all_from_static();
 313         if (plugin_set) {
 314                 for (j = 0; j < plugin_set->plugins->len; j++) {
 315                         struct bt_plugin *candidate_plugin =
 316                                 g_ptr_array_index(plugin_set->plugins, j);
 317
 318                         if (strcmp(bt_plugin_get_name(candidate_plugin),
 319                                         plugin_name) == 0) {
 320                                 BT_LOGD("Plugin found in built-in plugins: "
 321                                         "name=\"%s\"", plugin_name);
 322                                 plugin = bt_get(candidate_plugin);
 323                                 goto end;
 324                         }
 325                 }
 326         }
 327
 328 end:
 329         free(home_plugin_dir);
 330         bt_put(plugin_set);
 331
 332         if (dirs) {
 333                 g_ptr_array_free(dirs, TRUE);
 334         }
 335
 336         if (plugin) {
 337                 BT_LOGD("Found plugin in standard directories and built-in plugins: "
 338                         "addr=%p, name=\"%s\", path=\"%s\"",
 339                         plugin, plugin_name, bt_plugin_get_path(plugin));
 340         } else {
 341                 BT_LOGD("No plugin found in standard directories and built-in plugins: "
 342                         "name=\"%s\"", plugin_name);
 343         }
 344
 345         return plugin;
 346 }
 347
 348 struct bt_component_class *bt_plugin_find_component_class(
 349                 const char *plugin_name, const char *comp_cls_name,
 350                 enum bt_component_class_type comp_cls_type)
 351 {
 352         struct bt_plugin *plugin = NULL;
 353         struct bt_component_class *comp_cls = NULL;
 354
 355         if (!plugin_name) {
 356                 BT_LOGW_STR("Invalid parameter: plugin name is NULL.");
 357                 goto end;
 358         }
 359
 360         if (!comp_cls_name) {
 361                 BT_LOGW_STR("Invalid parameter: component class name is NULL.");
 362                 goto end;
 363         }
 364
 365         BT_LOGD("Finding named plugin and component class in standard directories and built-in plugins: "
 366                 "plugin-name=\"%s\", comp-class-name=\"%s\"",
 367                 plugin_name, comp_cls_name);
 368         plugin = bt_plugin_find(plugin_name);
 369         if (!plugin) {
 370                 BT_LOGD_STR("Plugin not found.");
 371                 goto end;
 372         }
 373
 374         comp_cls = bt_plugin_get_component_class_by_name_and_type(
 375                 plugin, comp_cls_name, comp_cls_type);
 376         if (!comp_cls) {
 377                 BT_LOGD("Component class not found in plugin: "
 378                         "plugin-addr=%p, plugin-path=\"%s\"",
 379                         plugin, bt_plugin_get_path(plugin));
 380         }
 381
 382 end:
 383         bt_put(plugin);
 384         return comp_cls;
 385 }
 386
 387 static struct {
 388         pthread_mutex_t lock;
 389         struct bt_plugin_set *plugin_set;
 390         bt_bool recurse;
 391 } append_all_from_dir_info = {
 392         .lock = PTHREAD_MUTEX_INITIALIZER
 393 };
 394
 395 static
 396 int nftw_append_all_from_dir(const char *file, const struct stat *sb, int flag,
 397                 struct FTW *s)
 398 {
 399         int ret = 0;
 400         const char *name = file + s->base;
 401
 402         /* Check for recursion */
 403         if (!append_all_from_dir_info.recurse && s->level > 1) {
 404                 goto end;
 405         }
 406
 407         switch (flag) {
 408         case FTW_F:
 409                 if (name[0] == '.') {
 410                         /* Skip hidden files */
 411                         BT_LOGV("Skipping hidden file: path=\"%s\"", file);
 412                         goto end;
 413                 }
 414                 struct bt_plugin_set *plugins_from_file =
 415                         bt_plugin_create_all_from_file(file);
 416
 417                 if (plugins_from_file) {
 418                         size_t j;
 419
 420                         for (j = 0; j < plugins_from_file->plugins->len; j++) {
 421                                 struct bt_plugin *plugin =
 422                                         g_ptr_array_index(plugins_from_file->plugins, j);
 423
 424                                 BT_LOGD("Adding plugin to plugin set: "
 425                                         "plugin-path=\"%s\", plugin-addr=%p, plugin-name=\"%s\"",
 426                                         file, plugin, bt_plugin_get_name(plugin));
 427                                 bt_plugin_set_add_plugin(append_all_from_dir_info.plugin_set, plugin);
 428                         }
 429
 430                         bt_put(plugins_from_file);
 431                 }
 432                 break;
 433         case FTW_DNR:
 434                 /* Continue to next file / directory. */
 435                 BT_LOGW("Cannot enter directory: continuing: path=\"%s\"", file);
 436                 break;
 437         case FTW_NS:
 438                 /* Continue to next file / directory. */
 439                 BT_LOGD("Cannot get file information: continuing: path=\"%s\"", file);
 440                 break;
 441         }
 442
 443 end:
 444         return ret;
 445 }
 446
 447 static
 448 enum bt_plugin_status bt_plugin_create_append_all_from_dir(
 449                 struct bt_plugin_set *plugin_set, const char *path,
 450                 bt_bool recurse)
 451 {
 452         int nftw_flags = FTW_PHYS;
 453         size_t path_len;
 454         enum bt_plugin_status ret = BT_PLUGIN_STATUS_OK;
 455
 456         if (!path) {
 457                 BT_LOGW_STR("Invalid parameter: path is NULL.");
 458                 ret = BT_PLUGIN_STATUS_ERROR;
 459                 goto end;
 460         }
 461
 462         path_len = strlen(path);
 463         if (path_len >= PATH_MAX) {
 464                 BT_LOGW("Invalid parameter: path length is too large: "
 465                         "path-length=%zu", path_len);
 466                 ret = BT_PLUGIN_STATUS_ERROR;
 467                 goto end;
 468         }
 469
 470         pthread_mutex_lock(&append_all_from_dir_info.lock);
 471
 472         append_all_from_dir_info.plugin_set = plugin_set;
 473         append_all_from_dir_info.recurse = recurse;
 474         ret = nftw(path, nftw_append_all_from_dir,
 475                 APPEND_ALL_FROM_DIR_NFDOPEN_MAX, nftw_flags);
 476
 477         pthread_mutex_unlock(&append_all_from_dir_info.lock);
 478
 479         if (ret != 0) {
 480                 BT_LOGW("Cannot open directory: %s: path=\"%s\", errno=%d",
 481                         strerror(errno), path, errno);
 482                 ret = BT_PLUGIN_STATUS_ERROR;
 483         }
 484
 485 end:
 486         return ret;
 487 }
 488
 489 struct bt_plugin_set *bt_plugin_create_all_from_dir(const char *path,
 490                 bt_bool recurse)
 491 {
 492         struct bt_plugin_set *plugin_set;
 493         enum bt_plugin_status status;
 494
 495         BT_LOGD("Creating all plugins in directory: path=\"%s\", recurse=%d",
 496                 path, recurse);
 497         plugin_set = bt_plugin_set_create();
 498         if (!plugin_set) {
 499                 BT_LOGE_STR("Cannot create empty plugin set.");
 500                 goto error;
 501         }
 502
 503         /* Append found plugins to array */
 504         status = bt_plugin_create_append_all_from_dir(plugin_set, path,
 505                 recurse);
 506         if (status < 0) {
 507                 BT_LOGW("Cannot append plugins found in directory: "
 508                         "path=\"%s\", status=%s",
 509                         path, bt_plugin_status_string(status));
 510                 goto error;
 511         }
 512
 513         BT_LOGD("Created %u plugins from directory: count=%u, path=\"%s\"",
 514                 plugin_set->plugins->len, plugin_set->plugins->len, path);
 515         goto end;
 516
 517 error:
 518         BT_PUT(plugin_set);
 519
 520 end:
 521         return plugin_set;
 522 }
 523
 524 const char *bt_plugin_get_name(struct bt_plugin *plugin)
 525 {
 526         const char *val = NULL;
 527
 528         if (!plugin) {
 529                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 530                 goto end;
 531         }
 532
 533         if (plugin->info.name_set) {
 534                 val = plugin->info.name->str;
 535         }
 536
 537 end:
 538         return val;
 539 }
 540
 541 const char *bt_plugin_get_author(struct bt_plugin *plugin)
 542 {
 543         const char *val = NULL;
 544
 545         if (!plugin) {
 546                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 547                 goto end;
 548         }
 549
 550         if (plugin->info.author_set) {
 551                 val = plugin->info.author->str;
 552         }
 553
 554 end:
 555         return val;
 556 }
 557
 558 const char *bt_plugin_get_license(struct bt_plugin *plugin)
 559 {
 560         const char *val = NULL;
 561
 562         if (!plugin) {
 563                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 564                 goto end;
 565         }
 566
 567         if (plugin->info.license_set) {
 568                 val = plugin->info.license->str;
 569         }
 570
 571 end:
 572         return val;
 573 }
 574
 575 const char *bt_plugin_get_path(struct bt_plugin *plugin)
 576 {
 577         const char *val = NULL;
 578
 579         if (!plugin) {
 580                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 581                 goto end;
 582         }
 583
 584         if (plugin->info.path_set) {
 585                 val = plugin->info.path->str;
 586         }
 587
 588 end:
 589         return val;
 590 }
 591
 592 const char *bt_plugin_get_description(struct bt_plugin *plugin)
 593 {
 594         const char *val = NULL;
 595
 596         if (!plugin) {
 597                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 598                 goto end;
 599         }
 600
 601         if (plugin->info.description_set) {
 602                 val = plugin->info.description->str;
 603         }
 604
 605 end:
 606         return val;
 607 }
 608
 609 enum bt_plugin_status bt_plugin_get_version(struct bt_plugin *plugin,
 610                 unsigned int *major, unsigned int *minor, unsigned int *patch,
 611                 const char **extra)
 612 {
 613         enum bt_plugin_status status = BT_PLUGIN_STATUS_OK;
 614
 615         if (!plugin) {
 616                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 617                 status = BT_PLUGIN_STATUS_ERROR;
 618                 goto end;
 619         }
 620
 621         if (!plugin->info.version_set) {
 622                 BT_LOGV("Plugin's version is not set: addr=%p", plugin);
 623                 status = BT_PLUGIN_STATUS_ERROR;
 624                 goto end;
 625         }
 626
 627         if (major) {
 628                 *major = plugin->info.version.major;
 629         }
 630
 631         if (minor) {
 632                 *minor = plugin->info.version.minor;
 633         }
 634
 635         if (patch) {
 636                 *patch = plugin->info.version.patch;
 637         }
 638
 639         if (extra) {
 640                 *extra = plugin->info.version.extra->str;
 641         }
 642
 643 end:
 644         return status;
 645 }
 646
 647 int64_t bt_plugin_get_component_class_count(struct bt_plugin *plugin)
 648 {
 649         return plugin ? plugin->comp_classes->len : (int64_t) -1;
 650 }
 651
 652 struct bt_component_class *bt_plugin_get_component_class_by_index(
 653                 struct bt_plugin *plugin, uint64_t index)
 654 {
 655         struct bt_component_class *comp_class = NULL;
 656
 657         if (!plugin) {
 658                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 659                 goto error;
 660         }
 661
 662         if (index >= plugin->comp_classes->len) {
 663                 BT_LOGW("Invalid parameter: index is out of bounds: "
 664                         "addr=%p, index=%" PRIu64 ", count=%u",
 665                         plugin, index, plugin->comp_classes->len);
 666                 goto error;
 667         }
 668
 669         comp_class = g_ptr_array_index(plugin->comp_classes, index);
 670         bt_get(comp_class);
 671         goto end;
 672
 673 error:
 674         BT_PUT(comp_class);
 675
 676 end:
 677         return comp_class;
 678 }
 679
 680 struct bt_component_class *bt_plugin_get_component_class_by_name_and_type(
 681                 struct bt_plugin *plugin, const char *name,
 682                 enum bt_component_class_type type)
 683 {
 684         struct bt_component_class *comp_class = NULL;
 685         size_t i;
 686
 687         if (!plugin) {
 688                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 689                 goto error;
 690         }
 691
 692         if (!name) {
 693                 BT_LOGW_STR("Invalid parameter: name is NULL.");
 694                 goto error;
 695         }
 696
 697         for (i = 0; i < plugin->comp_classes->len; i++) {
 698                 struct bt_component_class *comp_class_candidate =
 699                         g_ptr_array_index(plugin->comp_classes, i);
 700                 const char *comp_class_cand_name =
 701                         bt_component_class_get_name(comp_class_candidate);
 702                 enum bt_component_class_type comp_class_cand_type =
 703                         bt_component_class_get_type(comp_class_candidate);
 704
 705                 assert(comp_class_cand_name);
 706                 assert(comp_class_cand_type >= 0);
 707
 708                 if (strcmp(name, comp_class_cand_name) == 0 &&
 709                                 comp_class_cand_type == type) {
 710                         comp_class = bt_get(comp_class_candidate);
 711                         break;
 712                 }
 713         }
 714
 715         goto end;
 716
 717 error:
 718         BT_PUT(comp_class);
 719
 720 end:
 721         return comp_class;
 722 }
 723
 724 enum bt_plugin_status bt_plugin_add_component_class(
 725         struct bt_plugin *plugin, struct bt_component_class *comp_class)
 726 {
 727         enum bt_plugin_status status = BT_PLUGIN_STATUS_OK;
 728         struct bt_component_class *comp_class_dup = NULL;
 729         int comp_class_index = -1;
 730
 731         if (!plugin) {
 732                 BT_LOGW_STR("Invalid parameter: plugin is NULL.");
 733                 goto error;
 734         }
 735
 736         if (!comp_class) {
 737                 BT_LOGW_STR("Invalid parameter: component class is NULL.");
 738                 goto error;
 739         }
 740
 741         if (plugin->frozen) {
 742                 BT_LOGW("Invalid parameter: plugin is frozen: "
 743                         "addr=%p, name=\"%s\"", plugin,
 744                         bt_plugin_get_name(plugin));
 745                 goto error;
 746         }
 747
 748         /* Check for duplicate */
 749         comp_class_dup = bt_plugin_get_component_class_by_name_and_type(plugin,
 750                 bt_component_class_get_name(comp_class),
 751                 bt_component_class_get_type(comp_class));
 752         if (comp_class_dup) {
 753                 BT_LOGW("Invalid parameter: a component class with this name and type already exists in the plugin: "
 754                         "plugin-addr=%p, plugin-name=\"%s\", plugin-path=\"%s\", "
 755                         "comp-class-name=\"%s\", comp-class-type=%s",
 756                         plugin, bt_plugin_get_name(plugin),
 757                         bt_plugin_get_path(plugin),
 758                         bt_component_class_get_name(comp_class),
 759                         bt_component_class_type_string(
 760                                 bt_component_class_get_type(comp_class)));
 761                 goto error;
 762         }
 763
 764         /* Add new component class */
 765         comp_class_index = plugin->comp_classes->len;
 766         g_ptr_array_add(plugin->comp_classes, bt_get(comp_class));
 767
 768         /* Special case for a shared object plugin */
 769         if (plugin->type == BT_PLUGIN_TYPE_SO) {
 770                 bt_plugin_so_on_add_component_class(plugin, comp_class);
 771         }
 772
 773         BT_LOGD("Added component class to plugin: "
 774                 "plugin-addr=%p, plugin-name=\"%s\", plugin-path=\"%s\", "
 775                 "comp-class-addr=%p, comp-class-name=\"%s\", comp-class-type=%s",
 776                 plugin, bt_plugin_get_name(plugin),
 777                 bt_plugin_get_path(plugin),
 778                 comp_class,
 779                 bt_component_class_get_name(comp_class),
 780                 bt_component_class_type_string(
 781                         bt_component_class_get_type(comp_class)));
 782         goto end;
 783
 784 error:
 785         /* Remove entry from plugin's component classes (if added) */
 786         if (comp_class_index >= 0) {
 787                 g_ptr_array_remove_index(plugin->comp_classes,
 788                         comp_class_index);
 789         }
 790
 791         status = BT_PLUGIN_STATUS_ERROR;
 792
 793 end:
 794         bt_put(comp_class_dup);
 795         return status;
 796 }