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