src/lib/plugin/plugin.c

   1 /*
   2  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   3  * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #define BT_LOG_TAG "LIB/PLUGIN"
  27 #include "lib/logging.h"
  28
  29 #include "common/assert.h"
  30 #include "lib/assert-pre.h"
  31 #include "common/macros.h"
  32 #include "compat/compiler.h"
  33 #include "common/common.h"
  34 #include <babeltrace2/plugin/plugin-const.h>
  35 #include <babeltrace2/graph/component-class-const.h>
  36 #include <babeltrace2/current-thread.h>
  37 #include "lib/graph/component-class.h"
  38 #include <babeltrace2/types.h>
  39 #include <glib.h>
  40 #include <unistd.h>
  41 #include <stdlib.h>
  42 #include <stdint.h>
  43 #include <inttypes.h>
  44 #include <sys/stat.h>
  45 #include <ftw.h>
  46 #include <pthread.h>
  47
  48 #include "plugin.h"
  49 #include "plugin-so.h"
  50 #include "lib/func-status.h"
  51
  52 #define PYTHON_PLUGIN_PROVIDER_FILENAME "babeltrace2-python-plugin-provider." G_MODULE_SUFFIX
  53 #define PYTHON_PLUGIN_PROVIDER_DIR      BABELTRACE_PLUGIN_PROVIDERS_DIR
  54 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME bt_plugin_python_create_all_from_file
  55 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR     G_STRINGIFY(PYTHON_PLUGIN_PROVIDER_SYM_NAME)
  56
  57 #define APPEND_ALL_FROM_DIR_NFDOPEN_MAX 8
  58
  59 #ifdef BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT
  60 #include <plugin/python-plugin-provider.h>
  61
  62 static
  63 int (*bt_plugin_python_create_all_from_file_sym)(
  64                 const char *path, bool fail_on_load_error,
  65                 struct bt_plugin_set **plugin_set_out) =
  66         bt_plugin_python_create_all_from_file;
  67
  68 static
  69 enum bt_plugin_status init_python_plugin_provider(void)
  70 {
  71 }
  72 #else /* BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT */
  73 static GModule *python_plugin_provider_module;
  74
  75 static
  76 int (*bt_plugin_python_create_all_from_file_sym)(
  77                 const char *path, bool fail_on_load_error,
  78                  struct bt_plugin_set **plugin_set_out);
  79
  80 static
  81 int init_python_plugin_provider(void) {
  82         int status = BT_FUNC_STATUS_OK;
  83         const char *provider_dir_envvar;
  84         static const char * const provider_dir_envvar_name = "LIBBABELTRACE2_PLUGIN_PROVIDER_DIR";
  85         char *provider_path = NULL;
  86
  87         if (bt_plugin_python_create_all_from_file_sym) {
  88                 goto end;
  89         }
  90
  91         BT_LOGI_STR("Loading Python plugin provider module.");
  92
  93         provider_dir_envvar = getenv(provider_dir_envvar_name);
  94         if (provider_dir_envvar) {
  95                 provider_path = g_build_filename(provider_dir_envvar,
  96                         PYTHON_PLUGIN_PROVIDER_FILENAME, NULL);
  97                 BT_LOGI("Using `%s` environment variable to find the Python "
  98                         "plugin provider: path=\"%s\"", provider_dir_envvar_name,
  99                         provider_path);
 100         } else {
 101                 provider_path = g_build_filename(PYTHON_PLUGIN_PROVIDER_DIR,
 102                         PYTHON_PLUGIN_PROVIDER_FILENAME, NULL);
 103                 BT_LOGI("Using default path (`%s` environment variable is not "
 104                         "set) to find the Python plugin provider: path=\"%s\"",
 105                         provider_dir_envvar_name, provider_path);
 106         }
 107
 108         python_plugin_provider_module = g_module_open(provider_path, 0);
 109         if (!python_plugin_provider_module) {
 110                 /*
 111                  * This is not an error. The whole point of having an
 112                  * external Python plugin provider is that it can be
 113                  * missing and the Babeltrace library still works.
 114                  */
 115                 BT_LOGI("Cannot open `%s`: %s: continuing without Python plugin support.",
 116                         provider_path, g_module_error());
 117                 goto end;
 118         }
 119
 120         if (!g_module_symbol(python_plugin_provider_module,
 121                         PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR,
 122                         (gpointer) &bt_plugin_python_create_all_from_file_sym)) {
 123                 /*
 124                  * This is an error because, since we found the Python
 125                  * plugin provider shared object, we expect this symbol
 126                  * to exist.
 127                  */
 128                 BT_LIB_LOGE_APPEND_CAUSE(
 129                         "Cannot find the Python plugin provider loading symbol: "
 130                         "%s: continuing without Python plugin support: "
 131                         "file=\"%s\", symbol=\"%s\"",
 132                         g_module_error(),
 133                         provider_path,
 134                         PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR);
 135                 status = BT_FUNC_STATUS_ERROR;
 136                 goto end;
 137         }
 138
 139         BT_LOGI("Loaded Python plugin provider module: addr=%p",
 140                 python_plugin_provider_module);
 141
 142 end:
 143         g_free(provider_path);
 144
 145         return status;
 146 }
 147
 148 __attribute__((destructor)) static
 149 void fini_python_plugin_provider(void) {
 150         if (python_plugin_provider_module) {
 151                 BT_LOGI("Unloading Python plugin provider module.");
 152
 153                 if (!g_module_close(python_plugin_provider_module)) {
 154                         /*
 155                          * This occurs when the library is finalized: do
 156                          * NOT append an error cause.
 157                          */
 158                         BT_LOGE("Failed to close the Python plugin provider module: %s.",
 159                                 g_module_error());
 160                 }
 161
 162                 python_plugin_provider_module = NULL;
 163         }
 164 }
 165 #endif
 166
 167 uint64_t bt_plugin_set_get_plugin_count(const struct bt_plugin_set *plugin_set)
 168 {
 169         BT_ASSERT_PRE_DEV_NON_NULL(plugin_set, "Plugin set");
 170         return (uint64_t) plugin_set->plugins->len;
 171 }
 172
 173 const struct bt_plugin *bt_plugin_set_borrow_plugin_by_index_const(
 174                 const struct bt_plugin_set *plugin_set, uint64_t index)
 175 {
 176         BT_ASSERT_PRE_DEV_NON_NULL(plugin_set, "Plugin set");
 177         BT_ASSERT_PRE_DEV_VALID_INDEX(index, plugin_set->plugins->len);
 178         return g_ptr_array_index(plugin_set->plugins, index);
 179 }
 180
 181 enum bt_plugin_find_all_from_static_status bt_plugin_find_all_from_static(
 182                 bt_bool fail_on_load_error,
 183                 const struct bt_plugin_set **plugin_set_out)
 184 {
 185         /* bt_plugin_so_create_all_from_static() logs errors */
 186         return bt_plugin_so_create_all_from_static(fail_on_load_error,
 187                 (void *) plugin_set_out);
 188 }
 189
 190 enum bt_plugin_find_all_from_file_status bt_plugin_find_all_from_file(
 191                 const char *path, bt_bool fail_on_load_error,
 192                 const struct bt_plugin_set **plugin_set_out)
 193 {
 194         enum bt_plugin_find_all_from_file_status status;
 195
 196         BT_ASSERT_PRE_NON_NULL(path, "Path");
 197         BT_ASSERT_PRE_NON_NULL(path, "Plugin set (output)");
 198         BT_LOGI("Creating plugins from file: path=\"%s\"", path);
 199
 200         /* Try shared object plugins */
 201         status = bt_plugin_so_create_all_from_file(path, fail_on_load_error,
 202                 (void *) plugin_set_out);
 203         if (status == BT_FUNC_STATUS_OK) {
 204                 BT_ASSERT(*plugin_set_out);
 205                 BT_ASSERT((*plugin_set_out)->plugins->len > 0);
 206                 goto end;
 207         } else if (status < 0) {
 208                 BT_ASSERT(!*plugin_set_out);
 209                 goto end;
 210         }
 211
 212         BT_ASSERT(status == BT_FUNC_STATUS_NOT_FOUND);
 213         BT_ASSERT(!*plugin_set_out);
 214
 215         /* Try Python plugins if support is available */
 216         status = init_python_plugin_provider();
 217         if (status < 0) {
 218                 /* init_python_plugin_provider() logs errors */
 219                 goto end;
 220         }
 221
 222         BT_ASSERT(status == BT_FUNC_STATUS_OK);
 223         status = BT_FUNC_STATUS_NOT_FOUND;
 224
 225         if (bt_plugin_python_create_all_from_file_sym) {
 226                 /* Python plugin provider exists */
 227                 status = bt_plugin_python_create_all_from_file_sym(path,
 228                         fail_on_load_error, (void *) plugin_set_out);
 229                 if (status == BT_FUNC_STATUS_OK) {
 230                         BT_ASSERT(*plugin_set_out);
 231                         BT_ASSERT((*plugin_set_out)->plugins->len > 0);
 232                         goto end;
 233                 } else if (status < 0) {
 234                         /*
 235                          * bt_plugin_python_create_all_from_file_sym()
 236                          * handles `fail_on_load_error` itself, so this
 237                          * is a "real" error.
 238                          */
 239                         BT_ASSERT(!*plugin_set_out);
 240                         goto end;
 241                 }
 242
 243                 BT_ASSERT(status == BT_FUNC_STATUS_NOT_FOUND);
 244                 BT_ASSERT(!*plugin_set_out);
 245         }
 246
 247 end:
 248         if (status == BT_FUNC_STATUS_OK) {
 249                 BT_LOGI("Created %u plugins from file: "
 250                         "path=\"%s\", count=%u, plugin-set-addr=%p",
 251                         (*plugin_set_out)->plugins->len, path,
 252                         (*plugin_set_out)->plugins->len,
 253                         *plugin_set_out);
 254         } else if (status == BT_FUNC_STATUS_NOT_FOUND) {
 255                 BT_LOGI("Found no plugins in file: path=\"%s\"", path);
 256         }
 257
 258         return status;
 259 }
 260
 261 static
 262 void destroy_gstring(void *data)
 263 {
 264         g_string_free(data, TRUE);
 265 }
 266
 267 enum bt_plugin_find_all_status bt_plugin_find_all(bt_bool find_in_std_env_var,
 268                 bt_bool find_in_user_dir, bt_bool find_in_sys_dir,
 269                 bt_bool find_in_static, bt_bool fail_on_load_error,
 270                 const struct bt_plugin_set **plugin_set_out)
 271 {
 272         char *home_plugin_dir = NULL;
 273         const struct bt_plugin_set *plugin_set = NULL;
 274         GPtrArray *dirs = NULL;
 275         int ret;
 276         int status = BT_FUNC_STATUS_OK;
 277         uint64_t dir_i, plugin_i;
 278
 279         BT_ASSERT_PRE_NON_NULL(plugin_set_out, "Plugin set (output)");
 280         BT_LOGI("Finding all plugins in standard directories and built-in plugins: "
 281                 "find-in-std-env-var=%d, find-in-user-dir=%d, "
 282                 "find-in-sys-dir=%d, find-in-static=%d",
 283                 find_in_std_env_var, find_in_user_dir, find_in_sys_dir,
 284                 find_in_static);
 285         dirs = g_ptr_array_new_with_free_func((GDestroyNotify) destroy_gstring);
 286         if (!dirs) {
 287                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray.");
 288                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 289                 goto end;
 290         }
 291
 292         *plugin_set_out = bt_plugin_set_create();
 293         if (!*plugin_set_out) {
 294                 BT_LIB_LOGE_APPEND_CAUSE("Cannot create empty plugin set.");
 295                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 296                 goto end;
 297         }
 298
 299         /*
 300          * Search order is:
 301          *
 302          * 1. `BABELTRACE_PLUGIN_PATH` environment variable
 303          *    (colon-separated list of directories)
 304          * 2. `~/.local/lib/babeltrace2/plugins`
 305          * 3. Default system directory for Babeltrace plugins, usually
 306          *    `/usr/lib/babeltrace2/plugins` or
 307          *    `/usr/local/lib/babeltrace2/plugins` if installed locally
 308          * 4. Built-in plugins (static)
 309          *
 310          * Directories are searched non-recursively.
 311          */
 312         if (find_in_std_env_var) {
 313                 const char *envvar = getenv("BABELTRACE_PLUGIN_PATH");
 314
 315                 if (envvar) {
 316                         ret = bt_common_append_plugin_path_dirs(envvar, dirs);
 317                         if (ret) {
 318                                 BT_LIB_LOGE_APPEND_CAUSE(
 319                                         "Failed to append plugin path to array of directories.");
 320                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 321                                 goto end;
 322                         }
 323                 }
 324         }
 325
 326         if (find_in_user_dir) {
 327                 home_plugin_dir = bt_common_get_home_plugin_path(
 328                         BT_LOG_OUTPUT_LEVEL);
 329                 if (home_plugin_dir) {
 330                         GString *home_plugin_dir_str = g_string_new(
 331                                 home_plugin_dir);
 332
 333                         if (!home_plugin_dir_str) {
 334                                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GString.");
 335                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 336                                 goto end;
 337                         }
 338
 339                         g_ptr_array_add(dirs, home_plugin_dir_str);
 340                 }
 341         }
 342
 343         if (find_in_sys_dir) {
 344                 const char *system_plugin_dir =
 345                         bt_common_get_system_plugin_path();
 346
 347                 if (system_plugin_dir) {
 348                         GString *system_plugin_dir_str =
 349                                 g_string_new(system_plugin_dir);
 350
 351                         if (!system_plugin_dir_str) {
 352                                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GString.");
 353                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 354                                 goto end;
 355                         }
 356
 357                         g_ptr_array_add(dirs, system_plugin_dir_str);
 358                 }
 359         }
 360
 361         for (dir_i = 0; dir_i < dirs->len; dir_i++) {
 362                 GString *dir = dirs->pdata[dir_i];
 363
 364                 BT_OBJECT_PUT_REF_AND_RESET(plugin_set);
 365
 366                 /*
 367                  * Skip this if the directory does not exist because
 368                  * bt_plugin_find_all_from_dir() would log a warning.
 369                  */
 370                 if (!g_file_test(dir->str, G_FILE_TEST_IS_DIR)) {
 371                         BT_LOGI("Skipping nonexistent directory path: "
 372                                 "path=\"%s\"", dir->str);
 373                         continue;
 374                 }
 375
 376                 /* bt_plugin_find_all_from_dir() logs details/errors */
 377                 status = bt_plugin_find_all_from_dir(dir->str, BT_FALSE,
 378                         fail_on_load_error, &plugin_set);
 379                 if (status < 0) {
 380                         BT_ASSERT(!plugin_set);
 381                         goto end;
 382                 } else if (status == BT_FUNC_STATUS_NOT_FOUND) {
 383                         BT_ASSERT(!plugin_set);
 384                         BT_LOGI("No plugins found in directory: path=\"%s\"",
 385                                 dir->str);
 386                         continue;
 387                 }
 388
 389                 BT_ASSERT(status == BT_FUNC_STATUS_OK);
 390                 BT_ASSERT(plugin_set);
 391                 BT_LOGI("Found plugins in directory: path=\"%s\", count=%u",
 392                         dir->str, plugin_set->plugins->len);
 393
 394                 for (plugin_i = 0; plugin_i < plugin_set->plugins->len;
 395                                 plugin_i++) {
 396                         bt_plugin_set_add_plugin((void *) *plugin_set_out,
 397                                 plugin_set->plugins->pdata[plugin_i]);
 398                 }
 399         }
 400
 401         if (find_in_static) {
 402                 BT_OBJECT_PUT_REF_AND_RESET(plugin_set);
 403                 status = bt_plugin_find_all_from_static(fail_on_load_error,
 404                         &plugin_set);
 405                 if (status < 0) {
 406                         BT_ASSERT(!plugin_set);
 407                         goto end;
 408                 } else if (status == BT_FUNC_STATUS_NOT_FOUND) {
 409                         BT_ASSERT(!plugin_set);
 410                         BT_LOGI_STR("No plugins found in built-in plugins.");
 411                         goto end;
 412                 }
 413
 414                 BT_ASSERT(status == BT_FUNC_STATUS_OK);
 415                 BT_ASSERT(plugin_set);
 416                 BT_LOGI("Found built-in plugins: count=%u",
 417                         plugin_set->plugins->len);
 418
 419                 for (plugin_i = 0; plugin_i < plugin_set->plugins->len;
 420                                 plugin_i++) {
 421                         bt_plugin_set_add_plugin((void *) *plugin_set_out,
 422                                 plugin_set->plugins->pdata[plugin_i]);
 423                 }
 424         }
 425
 426 end:
 427         free(home_plugin_dir);
 428         bt_object_put_ref(plugin_set);
 429
 430         if (dirs) {
 431                 g_ptr_array_free(dirs, TRUE);
 432         }
 433
 434         if (status < 0) {
 435                 BT_OBJECT_PUT_REF_AND_RESET(*plugin_set_out);
 436         } else {
 437                 BT_ASSERT(*plugin_set_out);
 438
 439                 if ((*plugin_set_out)->plugins->len > 0) {
 440                         BT_LOGI("Found plugins in standard directories and built-in plugins: "
 441                                 "count=%u", (*plugin_set_out)->plugins->len);
 442                         status = BT_FUNC_STATUS_OK;
 443                 } else {
 444                         BT_LOGI_STR("No plugins found in standard directories and built-in plugins.");
 445                         status = BT_FUNC_STATUS_NOT_FOUND;
 446                         BT_OBJECT_PUT_REF_AND_RESET(*plugin_set_out);
 447                 }
 448         }
 449
 450         return status;
 451 }
 452
 453 enum bt_plugin_find_status bt_plugin_find(const char *plugin_name,
 454                 bt_bool find_in_std_env_var, bt_bool find_in_user_dir,
 455                 bt_bool find_in_sys_dir, bt_bool find_in_static,
 456                 bt_bool fail_on_load_error, const struct bt_plugin **plugin_out)
 457 {
 458         enum bt_plugin_find_status status;
 459         const struct bt_plugin_set *plugin_set = NULL;
 460         uint64_t i;
 461
 462         BT_ASSERT_PRE_NON_NULL(plugin_name, "Name");
 463         BT_ASSERT_PRE_NON_NULL(plugin_out, "Plugin (output)");
 464         BT_LOGI("Finding named plugin in standard directories and built-in plugins: "
 465                 "name=\"%s\", find-in-std-env-var=%d, find-in-user-dir=%d, "
 466                 "find-in-sys-dir=%d, find-in-static=%d",
 467                 plugin_name, find_in_std_env_var, find_in_user_dir,
 468                 find_in_sys_dir, find_in_static);
 469         status = (enum bt_plugin_find_status) bt_plugin_find_all(find_in_std_env_var, find_in_user_dir,
 470                 find_in_sys_dir, find_in_static, fail_on_load_error,
 471                 &plugin_set);
 472         if (status != BT_FUNC_STATUS_OK) {
 473                 BT_ASSERT(!plugin_set);
 474                 goto end;
 475         }
 476
 477         BT_ASSERT(plugin_set);
 478
 479         for (i = 0; i < plugin_set->plugins->len; i++) {
 480                 const struct bt_plugin *plugin = plugin_set->plugins->pdata[i];
 481
 482                 if (strcmp(plugin->info.name->str, plugin_name) == 0) {
 483                         *plugin_out = plugin;
 484                         bt_object_get_ref_no_null_check(*plugin_out);
 485                         goto end;
 486                 }
 487         }
 488
 489         status = BT_FUNC_STATUS_NOT_FOUND;
 490
 491 end:
 492         if (status == BT_FUNC_STATUS_OK) {
 493                 BT_ASSERT(*plugin_out);
 494                 BT_LIB_LOGI("Found plugin in standard directories and built-in plugins: "
 495                         "%!+l", *plugin_out);
 496         } else if (status == BT_FUNC_STATUS_NOT_FOUND) {
 497                 BT_LOGI("No plugin found in standard directories and built-in plugins: "
 498                         "name=\"%s\"", plugin_name);
 499         }
 500
 501         bt_plugin_set_put_ref(plugin_set);
 502
 503         return status;
 504 }
 505
 506 static struct {
 507         pthread_mutex_t lock;
 508         struct bt_plugin_set *plugin_set;
 509         bool recurse;
 510         bool fail_on_load_error;
 511         int status;
 512 } append_all_from_dir_info = {
 513         .lock = PTHREAD_MUTEX_INITIALIZER
 514 };
 515
 516 static
 517 int nftw_append_all_from_dir(const char *file,
 518                 const struct stat *sb, 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                         "Babeltrace library",
 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 enum bt_plugin_find_all_from_dir_status bt_plugin_find_all_from_dir(
 657                 const char *path, bt_bool recurse, bt_bool fail_on_load_error,
 658                 const struct bt_plugin_set **plugin_set_out)
 659 {
 660         enum bt_plugin_find_all_from_dir_status status =
 661                 BT_FUNC_STATUS_OK;
 662
 663         BT_ASSERT_PRE_NON_NULL(plugin_set_out, "Plugin set (output)");
 664         BT_LOGI("Creating all plugins in directory: path=\"%s\", recurse=%d",
 665                 path, recurse);
 666         *plugin_set_out = bt_plugin_set_create();
 667         if (!*plugin_set_out) {
 668                 BT_LIB_LOGE_APPEND_CAUSE("Cannot create empty plugin set.");
 669                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 670                 goto error;
 671         }
 672
 673         /*
 674          * Append found plugins to array (never returns
 675          * `BT_FUNC_STATUS_NOT_FOUND`)
 676          */
 677         status = bt_plugin_create_append_all_from_dir((void *) *plugin_set_out,
 678                 path, recurse, fail_on_load_error);
 679         if (status < 0) {
 680                 /*
 681                  * bt_plugin_create_append_all_from_dir() handles
 682                  * `fail_on_load_error`, so this is a "real" error.
 683                  */
 684                 BT_LIB_LOGE_APPEND_CAUSE(
 685                         "Cannot append plugins found in directory: "
 686                         "path=\"%s\", status=%s",
 687                         path, bt_common_func_status_string(status));
 688                 goto error;
 689         }
 690
 691         BT_ASSERT(status == BT_FUNC_STATUS_OK);
 692
 693         if ((*plugin_set_out)->plugins->len == 0) {
 694                 /* Nothing was appended: not found */
 695                 BT_LOGI("No plugins found in directory: path=\"%s\"", path);
 696                 status = BT_FUNC_STATUS_NOT_FOUND;
 697                 goto error;
 698         }
 699
 700         BT_LOGI("Created %u plugins from directory: count=%u, path=\"%s\"",
 701                 (*plugin_set_out)->plugins->len,
 702                 (*plugin_set_out)->plugins->len, path);
 703         goto end;
 704
 705 error:
 706         BT_ASSERT(status != BT_FUNC_STATUS_OK);
 707         BT_OBJECT_PUT_REF_AND_RESET(*plugin_set_out);
 708
 709 end:
 710         return status;
 711 }
 712
 713 const char *bt_plugin_get_name(const struct bt_plugin *plugin)
 714 {
 715         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 716         return plugin->info.name_set ? plugin->info.name->str : NULL;
 717 }
 718
 719 const char *bt_plugin_get_author(const struct bt_plugin *plugin)
 720 {
 721         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 722         return plugin->info.author_set ? plugin->info.author->str : NULL;
 723 }
 724
 725 const char *bt_plugin_get_license(const struct bt_plugin *plugin)
 726 {
 727         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 728         return plugin->info.license_set ? plugin->info.license->str : NULL;
 729 }
 730
 731 const char *bt_plugin_get_path(const struct bt_plugin *plugin)
 732 {
 733         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 734         return plugin->info.path_set ? plugin->info.path->str : NULL;
 735 }
 736
 737 const char *bt_plugin_get_description(const struct bt_plugin *plugin)
 738 {
 739         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 740         return plugin->info.description_set ?
 741                 plugin->info.description->str : NULL;
 742 }
 743
 744 enum bt_property_availability bt_plugin_get_version(const struct bt_plugin *plugin,
 745                 unsigned int *major, unsigned int *minor, unsigned int *patch,
 746                 const char **extra)
 747 {
 748         enum bt_property_availability avail =
 749                 BT_PROPERTY_AVAILABILITY_AVAILABLE;
 750
 751         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 752
 753         if (!plugin->info.version_set) {
 754                 BT_LIB_LOGD("Plugin's version is not set: %!+l", plugin);
 755                 avail = BT_PROPERTY_AVAILABILITY_NOT_AVAILABLE;
 756                 goto end;
 757         }
 758
 759         if (major) {
 760                 *major = plugin->info.version.major;
 761         }
 762
 763         if (minor) {
 764                 *minor = plugin->info.version.minor;
 765         }
 766
 767         if (patch) {
 768                 *patch = plugin->info.version.patch;
 769         }
 770
 771         if (extra) {
 772                 *extra = plugin->info.version.extra->str;
 773         }
 774
 775 end:
 776         return avail;
 777 }
 778
 779 uint64_t bt_plugin_get_source_component_class_count(const struct bt_plugin *plugin)
 780 {
 781         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 782         return (uint64_t) plugin->src_comp_classes->len;
 783 }
 784
 785 uint64_t bt_plugin_get_filter_component_class_count(const struct bt_plugin *plugin)
 786 {
 787         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 788         return (uint64_t) plugin->flt_comp_classes->len;
 789 }
 790
 791 uint64_t bt_plugin_get_sink_component_class_count(const struct bt_plugin *plugin)
 792 {
 793         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 794         return (uint64_t) plugin->sink_comp_classes->len;
 795 }
 796
 797 static inline
 798 struct bt_component_class *borrow_component_class_by_index(
 799                 const struct bt_plugin *plugin, GPtrArray *comp_classes,
 800                 uint64_t index)
 801 {
 802         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 803         BT_ASSERT_PRE_DEV_VALID_INDEX(index, comp_classes->len);
 804         return g_ptr_array_index(comp_classes, index);
 805 }
 806
 807 const struct bt_component_class_source *
 808 bt_plugin_borrow_source_component_class_by_index_const(
 809                 const struct bt_plugin *plugin, uint64_t index)
 810 {
 811         return (const void *) borrow_component_class_by_index(plugin,
 812                 plugin->src_comp_classes, index);
 813 }
 814
 815 const struct bt_component_class_filter *
 816 bt_plugin_borrow_filter_component_class_by_index_const(
 817                 const struct bt_plugin *plugin, uint64_t index)
 818 {
 819         return (const void *) borrow_component_class_by_index(plugin,
 820                 plugin->flt_comp_classes, index);
 821 }
 822
 823 const struct bt_component_class_sink *
 824 bt_plugin_borrow_sink_component_class_by_index_const(
 825                 const struct bt_plugin *plugin, uint64_t index)
 826 {
 827         return (const void *) borrow_component_class_by_index(plugin,
 828                 plugin->sink_comp_classes, index);
 829 }
 830
 831 static inline
 832 struct bt_component_class *borrow_component_class_by_name(
 833                 const struct bt_plugin *plugin, GPtrArray *comp_classes,
 834                 const char *name)
 835 {
 836         struct bt_component_class *comp_class = NULL;
 837         size_t i;
 838
 839         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 840         BT_ASSERT_PRE_DEV_NON_NULL(name, "Name");
 841
 842         for (i = 0; i < comp_classes->len; i++) {
 843                 struct bt_component_class *comp_class_candidate =
 844                         g_ptr_array_index(comp_classes, i);
 845                 const char *comp_class_cand_name =
 846                         bt_component_class_get_name(comp_class_candidate);
 847
 848                 BT_ASSERT_DBG(comp_class_cand_name);
 849
 850                 if (strcmp(name, comp_class_cand_name) == 0) {
 851                         comp_class = comp_class_candidate;
 852                         break;
 853                 }
 854         }
 855
 856         return comp_class;
 857 }
 858
 859 const struct bt_component_class_source *
 860 bt_plugin_borrow_source_component_class_by_name_const(
 861                 const struct bt_plugin *plugin, const char *name)
 862 {
 863         return (const void *) borrow_component_class_by_name(plugin,
 864                 plugin->src_comp_classes, name);
 865 }
 866
 867 const struct bt_component_class_filter *
 868 bt_plugin_borrow_filter_component_class_by_name_const(
 869                 const struct bt_plugin *plugin, const char *name)
 870 {
 871         return (const void *) borrow_component_class_by_name(plugin,
 872                 plugin->flt_comp_classes, name);
 873 }
 874
 875 const struct bt_component_class_sink *
 876 bt_plugin_borrow_sink_component_class_by_name_const(
 877                 const struct bt_plugin *plugin, const char *name)
 878 {
 879         return (const void *) borrow_component_class_by_name(plugin,
 880                 plugin->sink_comp_classes, name);
 881 }
 882
 883 void bt_plugin_get_ref(const struct bt_plugin *plugin)
 884 {
 885         bt_object_get_ref(plugin);
 886 }
 887
 888 void bt_plugin_put_ref(const struct bt_plugin *plugin)
 889 {
 890         bt_object_put_ref(plugin);
 891 }
 892
 893 void bt_plugin_set_get_ref(const struct bt_plugin_set *plugin_set)
 894 {
 895         bt_object_get_ref(plugin_set);
 896 }
 897
 898 void bt_plugin_set_put_ref(const struct bt_plugin_set *plugin_set)
 899 {
 900         bt_object_put_ref(plugin_set);
 901 }