src/lib/plugin/plugin.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   5  * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   6  */
   7
   8 #define BT_LOG_TAG "LIB/PLUGIN"
   9 #include "lib/logging.h"
  10
  11 #include "common/assert.h"
  12 #include "lib/assert-cond.h"
  13 #include "common/macros.h"
  14 #include "compat/compiler.h"
  15 #include "compat/limits.h"
  16 #include "common/common.h"
  17 #include <babeltrace2/plugin/plugin-loading.h>
  18 #include <babeltrace2/graph/component-class.h>
  19 #include <babeltrace2/error-reporting.h>
  20 #include "lib/graph/component-class.h"
  21 #include <babeltrace2/types.h>
  22 #include <glib.h>
  23 #include <unistd.h>
  24 #include <stdbool.h>
  25 #include <stdlib.h>
  26 #include <stdint.h>
  27 #include <sys/stat.h>
  28 #include <ftw.h>
  29 #include <pthread.h>
  30
  31 #include "plugin.h"
  32 #include "plugin-so.h"
  33 #include "lib/func-status.h"
  34
  35 #define PYTHON_PLUGIN_PROVIDER_FILENAME "babeltrace2-python-plugin-provider." G_MODULE_SUFFIX
  36 #define PYTHON_PLUGIN_PROVIDER_DIR      BABELTRACE_PLUGIN_PROVIDERS_DIR
  37 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME bt_plugin_python_create_all_from_file
  38 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR     G_STRINGIFY(PYTHON_PLUGIN_PROVIDER_SYM_NAME)
  39
  40 #define APPEND_ALL_FROM_DIR_NFDOPEN_MAX 8
  41
  42 /* Declare here to make sure definition in both ifdef branches are in sync. */
  43 static
  44 int init_python_plugin_provider(void);
  45 typedef int (*create_all_from_file_sym_type)(
  46                 const char *path,
  47                 bool fail_on_load_error,
  48                 struct bt_plugin_set **plugin_set_out);
  49
  50 #ifdef BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT
  51 #include <plugin/python-plugin-provider.h>
  52
  53 static
  54 create_all_from_file_sym_type
  55         bt_plugin_python_create_all_from_file_sym =
  56                         bt_plugin_python_create_all_from_file;
  57
  58 static
  59 int init_python_plugin_provider(void)
  60 {
  61 }
  62 #else /* BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT */
  63 static GModule *python_plugin_provider_module;
  64
  65 static
  66 create_all_from_file_sym_type bt_plugin_python_create_all_from_file_sym;
  67
  68 static
  69 int init_python_plugin_provider(void) {
  70         int status = BT_FUNC_STATUS_OK;
  71         const char *provider_dir_envvar;
  72         static const char * const provider_dir_envvar_name = "LIBBABELTRACE2_PLUGIN_PROVIDER_DIR";
  73         char *provider_path = NULL;
  74
  75         if (bt_plugin_python_create_all_from_file_sym) {
  76                 goto end;
  77         }
  78
  79         BT_LOGI_STR("Loading Python plugin provider module.");
  80
  81         provider_dir_envvar = getenv(provider_dir_envvar_name);
  82         if (provider_dir_envvar) {
  83                 provider_path = g_build_filename(provider_dir_envvar,
  84                         PYTHON_PLUGIN_PROVIDER_FILENAME, NULL);
  85                 BT_LOGI("Using `%s` environment variable to find the Python "
  86                         "plugin provider: path=\"%s\"", provider_dir_envvar_name,
  87                         provider_path);
  88         } else {
  89                 provider_path = g_build_filename(PYTHON_PLUGIN_PROVIDER_DIR,
  90                         PYTHON_PLUGIN_PROVIDER_FILENAME, NULL);
  91                 BT_LOGI("Using default path (`%s` environment variable is not "
  92                         "set) to find the Python plugin provider: path=\"%s\"",
  93                         provider_dir_envvar_name, provider_path);
  94         }
  95
  96         python_plugin_provider_module = g_module_open(provider_path, 0);
  97         if (!python_plugin_provider_module) {
  98                 /*
  99                  * This is not an error. The whole point of having an
 100                  * external Python plugin provider is that it can be
 101                  * missing and the Babeltrace library still works.
 102                  */
 103                 BT_LOGI("Cannot open `%s`: %s: continuing without Python plugin support.",
 104                         provider_path, g_module_error());
 105                 goto end;
 106         }
 107
 108         if (!g_module_symbol(python_plugin_provider_module,
 109                         PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR,
 110                         (gpointer) &bt_plugin_python_create_all_from_file_sym)) {
 111                 /*
 112                  * This is an error because, since we found the Python
 113                  * plugin provider shared object, we expect this symbol
 114                  * to exist.
 115                  */
 116                 BT_LIB_LOGE_APPEND_CAUSE(
 117                         "Cannot find the Python plugin provider loading symbol: "
 118                         "%s: continuing without Python plugin support: "
 119                         "file=\"%s\", symbol=\"%s\"",
 120                         g_module_error(),
 121                         provider_path,
 122                         PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR);
 123                 status = BT_FUNC_STATUS_ERROR;
 124                 goto end;
 125         }
 126
 127         BT_LOGI("Loaded Python plugin provider module: addr=%p",
 128                 python_plugin_provider_module);
 129
 130 end:
 131         g_free(provider_path);
 132
 133         return status;
 134 }
 135
 136 __attribute__((destructor)) static
 137 void fini_python_plugin_provider(void) {
 138         if (python_plugin_provider_module) {
 139                 BT_LOGI("Unloading Python plugin provider module.");
 140
 141                 if (!g_module_close(python_plugin_provider_module)) {
 142                         /*
 143                          * This occurs when the library is finalized: do
 144                          * NOT append an error cause.
 145                          */
 146                         BT_LOGE("Failed to close the Python plugin provider module: %s.",
 147                                 g_module_error());
 148                 }
 149
 150                 python_plugin_provider_module = NULL;
 151         }
 152 }
 153 #endif
 154
 155 BT_EXPORT
 156 uint64_t bt_plugin_set_get_plugin_count(const struct bt_plugin_set *plugin_set)
 157 {
 158         BT_ASSERT_PRE_DEV_PLUGIN_SET_NON_NULL(plugin_set);
 159         return (uint64_t) plugin_set->plugins->len;
 160 }
 161
 162 BT_EXPORT
 163 const struct bt_plugin *bt_plugin_set_borrow_plugin_by_index_const(
 164                 const struct bt_plugin_set *plugin_set, uint64_t index)
 165 {
 166         BT_ASSERT_PRE_DEV_PLUGIN_SET_NON_NULL(plugin_set);
 167         BT_ASSERT_PRE_DEV_VALID_INDEX(index, plugin_set->plugins->len);
 168         return g_ptr_array_index(plugin_set->plugins, index);
 169 }
 170
 171 BT_EXPORT
 172 enum bt_plugin_find_all_from_static_status bt_plugin_find_all_from_static(
 173                 bt_bool fail_on_load_error,
 174                 const struct bt_plugin_set **plugin_set_out)
 175 {
 176         BT_ASSERT_PRE_NO_ERROR();
 177
 178         /* bt_plugin_so_create_all_from_static() logs errors */
 179         return bt_plugin_so_create_all_from_static(fail_on_load_error,
 180                 (void *) plugin_set_out);
 181 }
 182
 183 BT_EXPORT
 184 enum bt_plugin_find_all_from_file_status bt_plugin_find_all_from_file(
 185                 const char *path, bt_bool fail_on_load_error,
 186                 const struct bt_plugin_set **plugin_set_out)
 187 {
 188         enum bt_plugin_find_all_from_file_status status;
 189
 190         BT_ASSERT_PRE_NO_ERROR();
 191         BT_ASSERT_PRE_NON_NULL("path", path, "Path");
 192         BT_ASSERT_PRE_PLUGIN_SET_OUT_NON_NULL(plugin_set_out);
 193         BT_LOGI("Creating plugins from file: path=\"%s\"", path);
 194
 195         /* Try shared object plugins */
 196         status = bt_plugin_so_create_all_from_file(path, fail_on_load_error,
 197                 (void *) plugin_set_out);
 198         if (status == BT_FUNC_STATUS_OK) {
 199                 BT_ASSERT(*plugin_set_out);
 200                 BT_ASSERT((*plugin_set_out)->plugins->len > 0);
 201                 goto end;
 202         } else if (status < 0) {
 203                 BT_ASSERT(!*plugin_set_out);
 204                 goto end;
 205         }
 206
 207         BT_ASSERT(status == BT_FUNC_STATUS_NOT_FOUND);
 208         BT_ASSERT(!*plugin_set_out);
 209
 210         /* Try Python plugins if support is available */
 211         status = init_python_plugin_provider();
 212         if (status < 0) {
 213                 /* init_python_plugin_provider() logs errors */
 214                 goto end;
 215         }
 216
 217         BT_ASSERT(status == BT_FUNC_STATUS_OK);
 218         status = BT_FUNC_STATUS_NOT_FOUND;
 219
 220         if (bt_plugin_python_create_all_from_file_sym) {
 221                 /* Python plugin provider exists */
 222                 status = bt_plugin_python_create_all_from_file_sym(path,
 223                         fail_on_load_error, (void *) plugin_set_out);
 224                 if (status == BT_FUNC_STATUS_OK) {
 225                         BT_ASSERT(*plugin_set_out);
 226                         BT_ASSERT((*plugin_set_out)->plugins->len > 0);
 227                         goto end;
 228                 } else if (status < 0) {
 229                         /*
 230                          * bt_plugin_python_create_all_from_file_sym()
 231                          * handles `fail_on_load_error` itself, so this
 232                          * is a "real" error.
 233                          */
 234                         BT_ASSERT(!*plugin_set_out);
 235                         goto end;
 236                 }
 237
 238                 BT_ASSERT(status == BT_FUNC_STATUS_NOT_FOUND);
 239                 BT_ASSERT(!*plugin_set_out);
 240         }
 241
 242 end:
 243         if (status == BT_FUNC_STATUS_OK) {
 244                 BT_LOGI("Created %u plugins from file: "
 245                         "path=\"%s\", count=%u, plugin-set-addr=%p",
 246                         (*plugin_set_out)->plugins->len, path,
 247                         (*plugin_set_out)->plugins->len,
 248                         *plugin_set_out);
 249         } else if (status == BT_FUNC_STATUS_NOT_FOUND) {
 250                 BT_LOGI("Found no plugins in file: path=\"%s\"", path);
 251         }
 252
 253         return status;
 254 }
 255
 256 static
 257 void destroy_gstring(void *data)
 258 {
 259         g_string_free(data, TRUE);
 260 }
 261
 262 BT_EXPORT
 263 enum bt_plugin_find_all_status bt_plugin_find_all(bt_bool find_in_std_env_var,
 264                 bt_bool find_in_user_dir, bt_bool find_in_sys_dir,
 265                 bt_bool find_in_static, bt_bool fail_on_load_error,
 266                 const struct bt_plugin_set **plugin_set_out)
 267 {
 268         char *home_plugin_dir = NULL;
 269         const struct bt_plugin_set *plugin_set = NULL;
 270         GPtrArray *dirs = NULL;
 271         int ret;
 272         int status = BT_FUNC_STATUS_OK;
 273         uint64_t dir_i, plugin_i;
 274
 275         BT_ASSERT_PRE_NO_ERROR();
 276         BT_ASSERT_PRE_PLUGIN_SET_OUT_NON_NULL(plugin_set_out);
 277         BT_LOGI("Finding all plugins in standard directories and built-in plugins: "
 278                 "find-in-std-env-var=%d, find-in-user-dir=%d, "
 279                 "find-in-sys-dir=%d, find-in-static=%d",
 280                 find_in_std_env_var, find_in_user_dir, find_in_sys_dir,
 281                 find_in_static);
 282         dirs = g_ptr_array_new_with_free_func((GDestroyNotify) destroy_gstring);
 283         if (!dirs) {
 284                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray.");
 285                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 286                 goto end;
 287         }
 288
 289         *plugin_set_out = bt_plugin_set_create();
 290         if (!*plugin_set_out) {
 291                 BT_LIB_LOGE_APPEND_CAUSE("Cannot create empty plugin set.");
 292                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 293                 goto end;
 294         }
 295
 296         /*
 297          * Search order is:
 298          *
 299          * 1. `BABELTRACE_PLUGIN_PATH` environment variable
 300          *    (colon-separated list of directories)
 301          * 2. `~/.local/lib/babeltrace2/plugins`
 302          * 3. Default system directory for Babeltrace plugins, usually
 303          *    `/usr/lib/babeltrace2/plugins` or
 304          *    `/usr/local/lib/babeltrace2/plugins` if installed locally
 305          * 4. Built-in plugins (static)
 306          *
 307          * Directories are searched non-recursively.
 308          */
 309         if (find_in_std_env_var) {
 310                 const char *envvar = getenv("BABELTRACE_PLUGIN_PATH");
 311
 312                 if (envvar) {
 313                         ret = bt_common_append_plugin_path_dirs(envvar, dirs);
 314                         if (ret) {
 315                                 BT_LIB_LOGE_APPEND_CAUSE(
 316                                         "Failed to append plugin path to array of directories.");
 317                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 318                                 goto end;
 319                         }
 320                 }
 321         }
 322
 323         if (find_in_user_dir) {
 324                 home_plugin_dir = bt_common_get_home_plugin_path(
 325                         BT_LOG_OUTPUT_LEVEL);
 326                 if (home_plugin_dir) {
 327                         GString *home_plugin_dir_str = g_string_new(
 328                                 home_plugin_dir);
 329
 330                         if (!home_plugin_dir_str) {
 331                                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GString.");
 332                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 333                                 goto end;
 334                         }
 335
 336                         g_ptr_array_add(dirs, home_plugin_dir_str);
 337                 }
 338         }
 339
 340         if (find_in_sys_dir) {
 341                 const char *system_plugin_dir =
 342                         bt_common_get_system_plugin_path();
 343
 344                 if (system_plugin_dir) {
 345                         GString *system_plugin_dir_str =
 346                                 g_string_new(system_plugin_dir);
 347
 348                         if (!system_plugin_dir_str) {
 349                                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GString.");
 350                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 351                                 goto end;
 352                         }
 353
 354                         g_ptr_array_add(dirs, system_plugin_dir_str);
 355                 }
 356         }
 357
 358         for (dir_i = 0; dir_i < dirs->len; dir_i++) {
 359                 GString *dir = dirs->pdata[dir_i];
 360
 361                 BT_OBJECT_PUT_REF_AND_RESET(plugin_set);
 362
 363                 /*
 364                  * Skip this if the directory does not exist because
 365                  * bt_plugin_find_all_from_dir() would log a warning.
 366                  */
 367                 if (!g_file_test(dir->str, G_FILE_TEST_IS_DIR)) {
 368                         BT_LOGI("Skipping nonexistent directory path: "
 369                                 "path=\"%s\"", dir->str);
 370                         continue;
 371                 }
 372
 373                 /* bt_plugin_find_all_from_dir() logs details/errors */
 374                 status = bt_plugin_find_all_from_dir(dir->str, BT_FALSE,
 375                         fail_on_load_error, &plugin_set);
 376                 if (status < 0) {
 377                         BT_ASSERT(!plugin_set);
 378                         goto end;
 379                 } else if (status == BT_FUNC_STATUS_NOT_FOUND) {
 380                         BT_ASSERT(!plugin_set);
 381                         BT_LOGI("No plugins found in directory: path=\"%s\"",
 382                                 dir->str);
 383                         continue;
 384                 }
 385
 386                 BT_ASSERT(status == BT_FUNC_STATUS_OK);
 387                 BT_ASSERT(plugin_set);
 388                 BT_LOGI("Found plugins in directory: path=\"%s\", count=%u",
 389                         dir->str, plugin_set->plugins->len);
 390
 391                 for (plugin_i = 0; plugin_i < plugin_set->plugins->len;
 392                                 plugin_i++) {
 393                         bt_plugin_set_add_plugin((void *) *plugin_set_out,
 394                                 plugin_set->plugins->pdata[plugin_i]);
 395                 }
 396         }
 397
 398         if (find_in_static) {
 399                 BT_OBJECT_PUT_REF_AND_RESET(plugin_set);
 400                 status = bt_plugin_find_all_from_static(fail_on_load_error,
 401                         &plugin_set);
 402                 if (status < 0) {
 403                         BT_ASSERT(!plugin_set);
 404                         goto end;
 405                 } else if (status == BT_FUNC_STATUS_NOT_FOUND) {
 406                         BT_ASSERT(!plugin_set);
 407                         BT_LOGI_STR("No plugins found in built-in plugins.");
 408                         goto end;
 409                 }
 410
 411                 BT_ASSERT(status == BT_FUNC_STATUS_OK);
 412                 BT_ASSERT(plugin_set);
 413                 BT_LOGI("Found built-in plugins: count=%u",
 414                         plugin_set->plugins->len);
 415
 416                 for (plugin_i = 0; plugin_i < plugin_set->plugins->len;
 417                                 plugin_i++) {
 418                         bt_plugin_set_add_plugin((void *) *plugin_set_out,
 419                                 plugin_set->plugins->pdata[plugin_i]);
 420                 }
 421         }
 422
 423 end:
 424         free(home_plugin_dir);
 425         bt_object_put_ref(plugin_set);
 426
 427         if (dirs) {
 428                 g_ptr_array_free(dirs, TRUE);
 429         }
 430
 431         if (status < 0) {
 432                 BT_OBJECT_PUT_REF_AND_RESET(*plugin_set_out);
 433         } else {
 434                 BT_ASSERT(*plugin_set_out);
 435
 436                 if ((*plugin_set_out)->plugins->len > 0) {
 437                         BT_LOGI("Found plugins in standard directories and built-in plugins: "
 438                                 "count=%u", (*plugin_set_out)->plugins->len);
 439                         status = BT_FUNC_STATUS_OK;
 440                 } else {
 441                         BT_LOGI_STR("No plugins found in standard directories and built-in plugins.");
 442                         status = BT_FUNC_STATUS_NOT_FOUND;
 443                         BT_OBJECT_PUT_REF_AND_RESET(*plugin_set_out);
 444                 }
 445         }
 446
 447         return status;
 448 }
 449
 450 BT_EXPORT
 451 enum bt_plugin_find_status bt_plugin_find(const char *plugin_name,
 452                 bt_bool find_in_std_env_var, bt_bool find_in_user_dir,
 453                 bt_bool find_in_sys_dir, bt_bool find_in_static,
 454                 bt_bool fail_on_load_error, const struct bt_plugin **plugin_out)
 455 {
 456         enum bt_plugin_find_status status;
 457         const struct bt_plugin_set *plugin_set = NULL;
 458         uint64_t i;
 459
 460         BT_ASSERT_PRE_NO_ERROR();
 461         BT_ASSERT_PRE_NAME_NON_NULL(plugin_name);
 462         BT_ASSERT_PRE_PLUGIN_OUT_NON_NULL(plugin_out);
 463         BT_LOGI("Finding named plugin in standard directories and built-in plugins: "
 464                 "name=\"%s\", find-in-std-env-var=%d, find-in-user-dir=%d, "
 465                 "find-in-sys-dir=%d, find-in-static=%d",
 466                 plugin_name, find_in_std_env_var, find_in_user_dir,
 467                 find_in_sys_dir, find_in_static);
 468         status = (enum bt_plugin_find_status) bt_plugin_find_all(find_in_std_env_var, find_in_user_dir,
 469                 find_in_sys_dir, find_in_static, fail_on_load_error,
 470                 &plugin_set);
 471         if (status != BT_FUNC_STATUS_OK) {
 472                 BT_ASSERT(!plugin_set);
 473                 goto end;
 474         }
 475
 476         BT_ASSERT(plugin_set);
 477
 478         for (i = 0; i < plugin_set->plugins->len; i++) {
 479                 const struct bt_plugin *plugin = plugin_set->plugins->pdata[i];
 480
 481                 if (strcmp(plugin->info.name->str, plugin_name) == 0) {
 482                         *plugin_out = plugin;
 483                         bt_object_get_ref_no_null_check(*plugin_out);
 484                         goto end;
 485                 }
 486         }
 487
 488         status = BT_FUNC_STATUS_NOT_FOUND;
 489
 490 end:
 491         if (status == BT_FUNC_STATUS_OK) {
 492                 BT_ASSERT(*plugin_out);
 493                 BT_LIB_LOGI("Found plugin in standard directories and built-in plugins: "
 494                         "%!+l", *plugin_out);
 495         } else if (status == BT_FUNC_STATUS_NOT_FOUND) {
 496                 BT_LOGI("No plugin found in standard directories and built-in plugins: "
 497                         "name=\"%s\"", plugin_name);
 498         }
 499
 500         bt_plugin_set_put_ref(plugin_set);
 501
 502         return status;
 503 }
 504
 505 static struct {
 506         pthread_mutex_t lock;
 507         struct bt_plugin_set *plugin_set;
 508         bool recurse;
 509         bool fail_on_load_error;
 510         int status;
 511 } append_all_from_dir_info = {
 512         .lock = PTHREAD_MUTEX_INITIALIZER
 513 };
 514
 515 static
 516 int nftw_append_all_from_dir(const char *file,
 517                 const struct stat *sb __attribute__((unused)),
 518                 int flag, struct FTW *s)
 519 {
 520         int ret = 0;
 521         const char *name = file + s->base;
 522
 523         /* Check for recursion */
 524         if (!append_all_from_dir_info.recurse && s->level > 1) {
 525                 goto end;
 526         }
 527
 528         switch (flag) {
 529         case FTW_F:
 530         {
 531                 const struct bt_plugin_set *plugins_from_file = NULL;
 532
 533                 if (name[0] == '.') {
 534                         /* Skip hidden files */
 535                         BT_LOGI("Skipping hidden file: path=\"%s\"", file);
 536                         goto end;
 537                 }
 538
 539                 append_all_from_dir_info.status =
 540                         bt_plugin_find_all_from_file(file,
 541                                 append_all_from_dir_info.fail_on_load_error,
 542                                 &plugins_from_file);
 543                 if (append_all_from_dir_info.status == BT_FUNC_STATUS_OK) {
 544                         size_t j;
 545
 546                         BT_ASSERT(plugins_from_file);
 547
 548                         for (j = 0; j < plugins_from_file->plugins->len; j++) {
 549                                 struct bt_plugin *plugin =
 550                                         g_ptr_array_index(plugins_from_file->plugins, j);
 551
 552                                 BT_LIB_LOGI("Adding plugin to plugin set: "
 553                                         "plugin-path=\"%s\", %![plugin-]+l",
 554                                         file, plugin);
 555                                 bt_plugin_set_add_plugin(
 556                                         append_all_from_dir_info.plugin_set,
 557                                         plugin);
 558                         }
 559
 560                         bt_object_put_ref(plugins_from_file);
 561                         goto end;
 562                 } else if (append_all_from_dir_info.status < 0) {
 563                         /* bt_plugin_find_all_from_file() logs errors */
 564                         BT_ASSERT(!plugins_from_file);
 565                         ret = -1;
 566                         goto end;
 567                 }
 568
 569                 /*
 570                  * Not found in this file: this is no an error; continue
 571                  * walking the directories.
 572                  */
 573                 BT_ASSERT(!plugins_from_file);
 574                 BT_ASSERT(append_all_from_dir_info.status ==
 575                         BT_FUNC_STATUS_NOT_FOUND);
 576                 break;
 577         }
 578         case FTW_DNR:
 579                 /* Continue to next file / directory. */
 580                 BT_LOGI("Cannot enter directory: continuing: path=\"%s\"", file);
 581                 break;
 582         case FTW_NS:
 583                 /* Continue to next file / directory. */
 584                 BT_LOGI("Cannot get file information: continuing: path=\"%s\"", file);
 585                 break;
 586         }
 587
 588 end:
 589         return ret;
 590 }
 591
 592 static
 593 int bt_plugin_create_append_all_from_dir(struct bt_plugin_set *plugin_set,
 594                 const char *path, bt_bool recurse, bt_bool fail_on_load_error)
 595 {
 596         int nftw_flags = FTW_PHYS;
 597         int ret;
 598         int status;
 599         struct stat sb;
 600
 601         BT_ASSERT(plugin_set);
 602         BT_ASSERT(path);
 603         BT_ASSERT(strlen(path) < PATH_MAX);
 604
 605         /*
 606          * Make sure that path exists and is accessible.
 607          * This is necessary since Cygwin implementation of nftw() is not POSIX
 608          * compliant. Cygwin nftw() implementation does not fail on non-existent
 609          * path with ENOENT. Instead, it flags the directory as FTW_NS. FTW_NS during
 610          * nftw_append_all_from_dir is not treated as an error since we are
 611          * traversing the tree for plugin discovery.
 612          */
 613         if (stat(path, &sb)) {
 614                 BT_LOGW_ERRNO("Cannot open directory",
 615                         ": path=\"%s\", recurse=%d",
 616                         path, recurse);
 617                 (void) BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_UNKNOWN(
 618                         BT_LIB_LOG_LIBBABELTRACE2_NAME,
 619                         "Cannot open directory: path=\"%s\", recurse=%d",
 620                         path, recurse);
 621                 status = BT_FUNC_STATUS_ERROR;
 622                 goto end;
 623         }
 624
 625         pthread_mutex_lock(&append_all_from_dir_info.lock);
 626         append_all_from_dir_info.plugin_set = plugin_set;
 627         append_all_from_dir_info.recurse = recurse;
 628         append_all_from_dir_info.status = BT_FUNC_STATUS_OK;
 629         append_all_from_dir_info.fail_on_load_error = fail_on_load_error;
 630         ret = nftw(path, nftw_append_all_from_dir,
 631                 APPEND_ALL_FROM_DIR_NFDOPEN_MAX, nftw_flags);
 632         append_all_from_dir_info.plugin_set = NULL;
 633         status = append_all_from_dir_info.status;
 634         pthread_mutex_unlock(&append_all_from_dir_info.lock);
 635         if (ret) {
 636                 BT_LIB_LOGW_APPEND_CAUSE("Failed to walk directory",
 637                         ": path=\"%s\", recurse=%d",
 638                         path, recurse);
 639                 status = BT_FUNC_STATUS_ERROR;
 640                 goto end;
 641         }
 642
 643         if (status == BT_FUNC_STATUS_NOT_FOUND) {
 644                 /*
 645                  * We're just appending in this function; even if
 646                  * nothing was found, it's still okay from the caller's
 647                  * perspective.
 648                  */
 649                 status = BT_FUNC_STATUS_OK;
 650         }
 651
 652 end:
 653         return status;
 654 }
 655
 656 BT_EXPORT
 657 enum bt_plugin_find_all_from_dir_status bt_plugin_find_all_from_dir(
 658                 const char *path, bt_bool recurse, bt_bool fail_on_load_error,
 659                 const struct bt_plugin_set **plugin_set_out)
 660 {
 661         enum bt_plugin_find_all_from_dir_status status =
 662                 BT_FUNC_STATUS_OK;
 663
 664         BT_ASSERT_PRE_NO_ERROR();
 665         BT_ASSERT_PRE_PLUGIN_SET_OUT_NON_NULL(plugin_set_out);
 666         BT_LOGI("Creating all plugins in directory: path=\"%s\", recurse=%d",
 667                 path, recurse);
 668         *plugin_set_out = bt_plugin_set_create();
 669         if (!*plugin_set_out) {
 670                 BT_LIB_LOGE_APPEND_CAUSE("Cannot create empty plugin set.");
 671                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 672                 goto error;
 673         }
 674
 675         /*
 676          * Append found plugins to array (never returns
 677          * `BT_FUNC_STATUS_NOT_FOUND`)
 678          */
 679         status = bt_plugin_create_append_all_from_dir((void *) *plugin_set_out,
 680                 path, recurse, fail_on_load_error);
 681         if (status < 0) {
 682                 /*
 683                  * bt_plugin_create_append_all_from_dir() handles
 684                  * `fail_on_load_error`, so this is a "real" error.
 685                  */
 686                 BT_LIB_LOGE_APPEND_CAUSE(
 687                         "Cannot append plugins found in directory: "
 688                         "path=\"%s\", status=%s",
 689                         path, bt_common_func_status_string(status));
 690                 goto error;
 691         }
 692
 693         BT_ASSERT(status == BT_FUNC_STATUS_OK);
 694
 695         if ((*plugin_set_out)->plugins->len == 0) {
 696                 /* Nothing was appended: not found */
 697                 BT_LOGI("No plugins found in directory: path=\"%s\"", path);
 698                 status = BT_FUNC_STATUS_NOT_FOUND;
 699                 goto error;
 700         }
 701
 702         BT_LOGI("Created %u plugins from directory: count=%u, path=\"%s\"",
 703                 (*plugin_set_out)->plugins->len,
 704                 (*plugin_set_out)->plugins->len, path);
 705         goto end;
 706
 707 error:
 708         BT_ASSERT(status != BT_FUNC_STATUS_OK);
 709         BT_OBJECT_PUT_REF_AND_RESET(*plugin_set_out);
 710
 711 end:
 712         return status;
 713 }
 714
 715 BT_EXPORT
 716 const char *bt_plugin_get_name(const struct bt_plugin *plugin)
 717 {
 718         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 719         return plugin->info.name_set ? plugin->info.name->str : NULL;
 720 }
 721
 722 BT_EXPORT
 723 const char *bt_plugin_get_author(const struct bt_plugin *plugin)
 724 {
 725         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 726         return plugin->info.author_set ? plugin->info.author->str : NULL;
 727 }
 728
 729 BT_EXPORT
 730 const char *bt_plugin_get_license(const struct bt_plugin *plugin)
 731 {
 732         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 733         return plugin->info.license_set ? plugin->info.license->str : NULL;
 734 }
 735
 736 BT_EXPORT
 737 const char *bt_plugin_get_path(const struct bt_plugin *plugin)
 738 {
 739         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 740         return plugin->info.path_set ? plugin->info.path->str : NULL;
 741 }
 742
 743 BT_EXPORT
 744 const char *bt_plugin_get_description(const struct bt_plugin *plugin)
 745 {
 746         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 747         return plugin->info.description_set ?
 748                 plugin->info.description->str : NULL;
 749 }
 750
 751 BT_EXPORT
 752 enum bt_property_availability bt_plugin_get_version(const struct bt_plugin *plugin,
 753                 unsigned int *major, unsigned int *minor, unsigned int *patch,
 754                 const char **extra)
 755 {
 756         enum bt_property_availability avail =
 757                 BT_PROPERTY_AVAILABILITY_AVAILABLE;
 758
 759         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 760
 761         if (!plugin->info.version_set) {
 762                 BT_LIB_LOGD("Plugin's version is not set: %!+l", plugin);
 763                 avail = BT_PROPERTY_AVAILABILITY_NOT_AVAILABLE;
 764                 goto end;
 765         }
 766
 767         if (major) {
 768                 *major = plugin->info.version.major;
 769         }
 770
 771         if (minor) {
 772                 *minor = plugin->info.version.minor;
 773         }
 774
 775         if (patch) {
 776                 *patch = plugin->info.version.patch;
 777         }
 778
 779         if (extra) {
 780                 *extra = plugin->info.version.extra->str;
 781         }
 782
 783 end:
 784         return avail;
 785 }
 786
 787 BT_EXPORT
 788 uint64_t bt_plugin_get_source_component_class_count(const struct bt_plugin *plugin)
 789 {
 790         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 791         return (uint64_t) plugin->src_comp_classes->len;
 792 }
 793
 794 BT_EXPORT
 795 uint64_t bt_plugin_get_filter_component_class_count(const struct bt_plugin *plugin)
 796 {
 797         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 798         return (uint64_t) plugin->flt_comp_classes->len;
 799 }
 800
 801 BT_EXPORT
 802 uint64_t bt_plugin_get_sink_component_class_count(const struct bt_plugin *plugin)
 803 {
 804         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 805         return (uint64_t) plugin->sink_comp_classes->len;
 806 }
 807
 808 static inline
 809 struct bt_component_class *borrow_component_class_by_index(
 810                 const struct bt_plugin *plugin, GPtrArray *comp_classes,
 811                 uint64_t index)
 812 {
 813         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 814         BT_ASSERT_PRE_DEV_VALID_INDEX(index, comp_classes->len);
 815         return g_ptr_array_index(comp_classes, index);
 816 }
 817
 818 BT_EXPORT
 819 const struct bt_component_class_source *
 820 bt_plugin_borrow_source_component_class_by_index_const(
 821                 const struct bt_plugin *plugin, uint64_t index)
 822 {
 823         return (const void *) borrow_component_class_by_index(plugin,
 824                 plugin->src_comp_classes, index);
 825 }
 826
 827 BT_EXPORT
 828 const struct bt_component_class_filter *
 829 bt_plugin_borrow_filter_component_class_by_index_const(
 830                 const struct bt_plugin *plugin, uint64_t index)
 831 {
 832         return (const void *) borrow_component_class_by_index(plugin,
 833                 plugin->flt_comp_classes, index);
 834 }
 835
 836 BT_EXPORT
 837 const struct bt_component_class_sink *
 838 bt_plugin_borrow_sink_component_class_by_index_const(
 839                 const struct bt_plugin *plugin, uint64_t index)
 840 {
 841         return (const void *) borrow_component_class_by_index(plugin,
 842                 plugin->sink_comp_classes, index);
 843 }
 844
 845 static inline
 846 struct bt_component_class *borrow_component_class_by_name(
 847                 const struct bt_plugin *plugin, GPtrArray *comp_classes,
 848                 const char *name)
 849 {
 850         struct bt_component_class *comp_class = NULL;
 851         size_t i;
 852
 853         BT_ASSERT_PRE_DEV_PLUGIN_NON_NULL(plugin);
 854         BT_ASSERT_PRE_DEV_NAME_NON_NULL(name);
 855
 856         for (i = 0; i < comp_classes->len; i++) {
 857                 struct bt_component_class *comp_class_candidate =
 858                         g_ptr_array_index(comp_classes, i);
 859                 const char *comp_class_cand_name =
 860                         bt_component_class_get_name(comp_class_candidate);
 861
 862                 BT_ASSERT_DBG(comp_class_cand_name);
 863
 864                 if (strcmp(name, comp_class_cand_name) == 0) {
 865                         comp_class = comp_class_candidate;
 866                         break;
 867                 }
 868         }
 869
 870         return comp_class;
 871 }
 872
 873 BT_EXPORT
 874 const struct bt_component_class_source *
 875 bt_plugin_borrow_source_component_class_by_name_const(
 876                 const struct bt_plugin *plugin, const char *name)
 877 {
 878         return (const void *) borrow_component_class_by_name(plugin,
 879                 plugin->src_comp_classes, name);
 880 }
 881
 882 BT_EXPORT
 883 const struct bt_component_class_filter *
 884 bt_plugin_borrow_filter_component_class_by_name_const(
 885                 const struct bt_plugin *plugin, const char *name)
 886 {
 887         return (const void *) borrow_component_class_by_name(plugin,
 888                 plugin->flt_comp_classes, name);
 889 }
 890
 891 BT_EXPORT
 892 const struct bt_component_class_sink *
 893 bt_plugin_borrow_sink_component_class_by_name_const(
 894                 const struct bt_plugin *plugin, const char *name)
 895 {
 896         return (const void *) borrow_component_class_by_name(plugin,
 897                 plugin->sink_comp_classes, name);
 898 }
 899
 900 BT_EXPORT
 901 void bt_plugin_get_ref(const struct bt_plugin *plugin)
 902 {
 903         bt_object_get_ref(plugin);
 904 }
 905
 906 BT_EXPORT
 907 void bt_plugin_put_ref(const struct bt_plugin *plugin)
 908 {
 909         bt_object_put_ref(plugin);
 910 }
 911
 912 BT_EXPORT
 913 void bt_plugin_set_get_ref(const struct bt_plugin_set *plugin_set)
 914 {
 915         bt_object_get_ref(plugin_set);
 916 }
 917
 918 BT_EXPORT
 919 void bt_plugin_set_put_ref(const struct bt_plugin_set *plugin_set)
 920 {
 921         bt_object_put_ref(plugin_set);
 922 }