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                 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_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         return status;
 501 }
 502
 503 static struct {
 504         pthread_mutex_t lock;
 505         struct bt_plugin_set *plugin_set;
 506         bool recurse;
 507         bool fail_on_load_error;
 508         int status;
 509 } append_all_from_dir_info = {
 510         .lock = PTHREAD_MUTEX_INITIALIZER
 511 };
 512
 513 static
 514 int nftw_append_all_from_dir(const char *file,
 515                 const struct stat *sb, int flag, struct FTW *s)
 516 {
 517         int ret = 0;
 518         const char *name = file + s->base;
 519
 520         /* Check for recursion */
 521         if (!append_all_from_dir_info.recurse && s->level > 1) {
 522                 goto end;
 523         }
 524
 525         switch (flag) {
 526         case FTW_F:
 527         {
 528                 const struct bt_plugin_set *plugins_from_file = NULL;
 529
 530                 if (name[0] == '.') {
 531                         /* Skip hidden files */
 532                         BT_LOGI("Skipping hidden file: path=\"%s\"", file);
 533                         goto end;
 534                 }
 535
 536                 append_all_from_dir_info.status =
 537                         bt_plugin_find_all_from_file(file,
 538                                 append_all_from_dir_info.fail_on_load_error,
 539                                 &plugins_from_file);
 540                 if (append_all_from_dir_info.status == BT_FUNC_STATUS_OK) {
 541                         size_t j;
 542
 543                         BT_ASSERT(plugins_from_file);
 544
 545                         for (j = 0; j < plugins_from_file->plugins->len; j++) {
 546                                 struct bt_plugin *plugin =
 547                                         g_ptr_array_index(plugins_from_file->plugins, j);
 548
 549                                 BT_LIB_LOGI("Adding plugin to plugin set: "
 550                                         "plugin-path=\"%s\", %![plugin-]+l",
 551                                         file, plugin);
 552                                 bt_plugin_set_add_plugin(
 553                                         append_all_from_dir_info.plugin_set,
 554                                         plugin);
 555                         }
 556
 557                         bt_object_put_ref(plugins_from_file);
 558                         goto end;
 559                 } else if (append_all_from_dir_info.status < 0) {
 560                         /* bt_plugin_find_all_from_file() logs errors */
 561                         BT_ASSERT(!plugins_from_file);
 562                         ret = -1;
 563                         goto end;
 564                 }
 565
 566                 /*
 567                  * Not found in this file: this is no an error; continue
 568                  * walking the directories.
 569                  */
 570                 BT_ASSERT(!plugins_from_file);
 571                 BT_ASSERT(append_all_from_dir_info.status ==
 572                         BT_FUNC_STATUS_NOT_FOUND);
 573                 break;
 574         }
 575         case FTW_DNR:
 576                 /* Continue to next file / directory. */
 577                 BT_LOGI("Cannot enter directory: continuing: path=\"%s\"", file);
 578                 break;
 579         case FTW_NS:
 580                 /* Continue to next file / directory. */
 581                 BT_LOGI("Cannot get file information: continuing: path=\"%s\"", file);
 582                 break;
 583         }
 584
 585 end:
 586         return ret;
 587 }
 588
 589 static
 590 int bt_plugin_create_append_all_from_dir(struct bt_plugin_set *plugin_set,
 591                 const char *path, bt_bool recurse, bt_bool fail_on_load_error)
 592 {
 593         int nftw_flags = FTW_PHYS;
 594         int ret;
 595         int status;
 596         struct stat sb;
 597
 598         BT_ASSERT(plugin_set);
 599         BT_ASSERT(path);
 600         BT_ASSERT(strlen(path) < PATH_MAX);
 601
 602         /*
 603          * Make sure that path exists and is accessible.
 604          * This is necessary since Cygwin implementation of nftw() is not POSIX
 605          * compliant. Cygwin nftw() implementation does not fail on non-existent
 606          * path with ENOENT. Instead, it flags the directory as FTW_NS. FTW_NS during
 607          * nftw_append_all_from_dir is not treated as an error since we are
 608          * traversing the tree for plugin discovery.
 609          */
 610         if (stat(path, &sb)) {
 611                 BT_LOGW_ERRNO("Cannot open directory",
 612                         ": path=\"%s\", recurse=%d",
 613                         path, recurse);
 614                 (void) BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_UNKNOWN(
 615                         "Babeltrace library",
 616                         "Cannot open directory: path=\"%s\", recurse=%d",
 617                         path, recurse);
 618                 status = BT_FUNC_STATUS_ERROR;
 619                 goto end;
 620         }
 621
 622         pthread_mutex_lock(&append_all_from_dir_info.lock);
 623         append_all_from_dir_info.plugin_set = plugin_set;
 624         append_all_from_dir_info.recurse = recurse;
 625         append_all_from_dir_info.status = BT_FUNC_STATUS_OK;
 626         append_all_from_dir_info.fail_on_load_error = fail_on_load_error;
 627         ret = nftw(path, nftw_append_all_from_dir,
 628                 APPEND_ALL_FROM_DIR_NFDOPEN_MAX, nftw_flags);
 629         append_all_from_dir_info.plugin_set = NULL;
 630         status = append_all_from_dir_info.status;
 631         pthread_mutex_unlock(&append_all_from_dir_info.lock);
 632         if (ret) {
 633                 BT_LIB_LOGW_APPEND_CAUSE("Failed to walk directory",
 634                         ": path=\"%s\", recurse=%d",
 635                         path, recurse);
 636                 status = BT_FUNC_STATUS_ERROR;
 637                 goto end;
 638         }
 639
 640         if (status == BT_FUNC_STATUS_NOT_FOUND) {
 641                 /*
 642                  * We're just appending in this function; even if
 643                  * nothing was found, it's still okay from the caller's
 644                  * perspective.
 645                  */
 646                 status = BT_FUNC_STATUS_OK;
 647         }
 648
 649 end:
 650         return status;
 651 }
 652
 653 enum bt_plugin_find_all_from_dir_status bt_plugin_find_all_from_dir(
 654                 const char *path, bt_bool recurse, bt_bool fail_on_load_error,
 655                 const struct bt_plugin_set **plugin_set_out)
 656 {
 657         enum bt_plugin_find_all_from_dir_status status =
 658                 BT_FUNC_STATUS_OK;
 659
 660         BT_ASSERT_PRE_NON_NULL(plugin_set_out, "Plugin set (output)");
 661         BT_LOGI("Creating all plugins in directory: path=\"%s\", recurse=%d",
 662                 path, recurse);
 663         *plugin_set_out = bt_plugin_set_create();
 664         if (!*plugin_set_out) {
 665                 BT_LIB_LOGE_APPEND_CAUSE("Cannot create empty plugin set.");
 666                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 667                 goto error;
 668         }
 669
 670         /*
 671          * Append found plugins to array (never returns
 672          * `BT_FUNC_STATUS_NOT_FOUND`)
 673          */
 674         status = bt_plugin_create_append_all_from_dir((void *) *plugin_set_out,
 675                 path, recurse, fail_on_load_error);
 676         if (status < 0) {
 677                 /*
 678                  * bt_plugin_create_append_all_from_dir() handles
 679                  * `fail_on_load_error`, so this is a "real" error.
 680                  */
 681                 BT_LIB_LOGE_APPEND_CAUSE(
 682                         "Cannot append plugins found in directory: "
 683                         "path=\"%s\", status=%s",
 684                         path, bt_common_func_status_string(status));
 685                 goto error;
 686         }
 687
 688         BT_ASSERT(status == BT_FUNC_STATUS_OK);
 689
 690         if ((*plugin_set_out)->plugins->len == 0) {
 691                 /* Nothing was appended: not found */
 692                 BT_LOGI("No plugins found in directory: path=\"%s\"", path);
 693                 status = BT_FUNC_STATUS_NOT_FOUND;
 694                 goto error;
 695         }
 696
 697         BT_LOGI("Created %u plugins from directory: count=%u, path=\"%s\"",
 698                 (*plugin_set_out)->plugins->len,
 699                 (*plugin_set_out)->plugins->len, path);
 700         goto end;
 701
 702 error:
 703         BT_ASSERT(status != BT_FUNC_STATUS_OK);
 704         BT_OBJECT_PUT_REF_AND_RESET(*plugin_set_out);
 705
 706 end:
 707         return status;
 708 }
 709
 710 const char *bt_plugin_get_name(const struct bt_plugin *plugin)
 711 {
 712         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 713         return plugin->info.name_set ? plugin->info.name->str : NULL;
 714 }
 715
 716 const char *bt_plugin_get_author(const struct bt_plugin *plugin)
 717 {
 718         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 719         return plugin->info.author_set ? plugin->info.author->str : NULL;
 720 }
 721
 722 const char *bt_plugin_get_license(const struct bt_plugin *plugin)
 723 {
 724         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 725         return plugin->info.license_set ? plugin->info.license->str : NULL;
 726 }
 727
 728 const char *bt_plugin_get_path(const struct bt_plugin *plugin)
 729 {
 730         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 731         return plugin->info.path_set ? plugin->info.path->str : NULL;
 732 }
 733
 734 const char *bt_plugin_get_description(const struct bt_plugin *plugin)
 735 {
 736         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 737         return plugin->info.description_set ?
 738                 plugin->info.description->str : NULL;
 739 }
 740
 741 enum bt_property_availability bt_plugin_get_version(const struct bt_plugin *plugin,
 742                 unsigned int *major, unsigned int *minor, unsigned int *patch,
 743                 const char **extra)
 744 {
 745         enum bt_property_availability avail =
 746                 BT_PROPERTY_AVAILABILITY_AVAILABLE;
 747
 748         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 749
 750         if (!plugin->info.version_set) {
 751                 BT_LIB_LOGD("Plugin's version is not set: %!+l", plugin);
 752                 avail = BT_PROPERTY_AVAILABILITY_NOT_AVAILABLE;
 753                 goto end;
 754         }
 755
 756         if (major) {
 757                 *major = plugin->info.version.major;
 758         }
 759
 760         if (minor) {
 761                 *minor = plugin->info.version.minor;
 762         }
 763
 764         if (patch) {
 765                 *patch = plugin->info.version.patch;
 766         }
 767
 768         if (extra) {
 769                 *extra = plugin->info.version.extra->str;
 770         }
 771
 772 end:
 773         return avail;
 774 }
 775
 776 uint64_t bt_plugin_get_source_component_class_count(const struct bt_plugin *plugin)
 777 {
 778         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 779         return (uint64_t) plugin->src_comp_classes->len;
 780 }
 781
 782 uint64_t bt_plugin_get_filter_component_class_count(const struct bt_plugin *plugin)
 783 {
 784         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 785         return (uint64_t) plugin->flt_comp_classes->len;
 786 }
 787
 788 uint64_t bt_plugin_get_sink_component_class_count(const struct bt_plugin *plugin)
 789 {
 790         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 791         return (uint64_t) plugin->sink_comp_classes->len;
 792 }
 793
 794 static inline
 795 struct bt_component_class *borrow_component_class_by_index(
 796                 const struct bt_plugin *plugin, GPtrArray *comp_classes,
 797                 uint64_t index)
 798 {
 799         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 800         BT_ASSERT_PRE_DEV_VALID_INDEX(index, comp_classes->len);
 801         return g_ptr_array_index(comp_classes, index);
 802 }
 803
 804 const struct bt_component_class_source *
 805 bt_plugin_borrow_source_component_class_by_index_const(
 806                 const struct bt_plugin *plugin, uint64_t index)
 807 {
 808         return (const void *) borrow_component_class_by_index(plugin,
 809                 plugin->src_comp_classes, index);
 810 }
 811
 812 const struct bt_component_class_filter *
 813 bt_plugin_borrow_filter_component_class_by_index_const(
 814                 const struct bt_plugin *plugin, uint64_t index)
 815 {
 816         return (const void *) borrow_component_class_by_index(plugin,
 817                 plugin->flt_comp_classes, index);
 818 }
 819
 820 const struct bt_component_class_sink *
 821 bt_plugin_borrow_sink_component_class_by_index_const(
 822                 const struct bt_plugin *plugin, uint64_t index)
 823 {
 824         return (const void *) borrow_component_class_by_index(plugin,
 825                 plugin->sink_comp_classes, index);
 826 }
 827
 828 static inline
 829 struct bt_component_class *borrow_component_class_by_name(
 830                 const struct bt_plugin *plugin, GPtrArray *comp_classes,
 831                 const char *name)
 832 {
 833         struct bt_component_class *comp_class = NULL;
 834         size_t i;
 835
 836         BT_ASSERT_PRE_DEV_NON_NULL(plugin, "Plugin");
 837         BT_ASSERT_PRE_DEV_NON_NULL(name, "Name");
 838
 839         for (i = 0; i < comp_classes->len; i++) {
 840                 struct bt_component_class *comp_class_candidate =
 841                         g_ptr_array_index(comp_classes, i);
 842                 const char *comp_class_cand_name =
 843                         bt_component_class_get_name(comp_class_candidate);
 844
 845                 BT_ASSERT(comp_class_cand_name);
 846
 847                 if (strcmp(name, comp_class_cand_name) == 0) {
 848                         comp_class = comp_class_candidate;
 849                         break;
 850                 }
 851         }
 852
 853         return comp_class;
 854 }
 855
 856 const struct bt_component_class_source *
 857 bt_plugin_borrow_source_component_class_by_name_const(
 858                 const struct bt_plugin *plugin, const char *name)
 859 {
 860         return (const void *) borrow_component_class_by_name(plugin,
 861                 plugin->src_comp_classes, name);
 862 }
 863
 864 const struct bt_component_class_filter *
 865 bt_plugin_borrow_filter_component_class_by_name_const(
 866                 const struct bt_plugin *plugin, const char *name)
 867 {
 868         return (const void *) borrow_component_class_by_name(plugin,
 869                 plugin->flt_comp_classes, name);
 870 }
 871
 872 const struct bt_component_class_sink *
 873 bt_plugin_borrow_sink_component_class_by_name_const(
 874                 const struct bt_plugin *plugin, const char *name)
 875 {
 876         return (const void *) borrow_component_class_by_name(plugin,
 877                 plugin->sink_comp_classes, name);
 878 }
 879
 880 void bt_plugin_get_ref(const struct bt_plugin *plugin)
 881 {
 882         bt_object_get_ref(plugin);
 883 }
 884
 885 void bt_plugin_put_ref(const struct bt_plugin *plugin)
 886 {
 887         bt_object_put_ref(plugin);
 888 }
 889
 890 void bt_plugin_set_get_ref(const struct bt_plugin_set *plugin_set)
 891 {
 892         bt_object_get_ref(plugin_set);
 893 }
 894
 895 void bt_plugin_set_put_ref(const struct bt_plugin_set *plugin_set)
 896 {
 897         bt_object_put_ref(plugin_set);
 898 }