lib/plugin/plugin.c

   1 /*
   2  * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  * Copyright 2017 Philippe Proulx <pproulx@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 "PLUGIN"
  27 #include <babeltrace/lib-logging-internal.h>
  28
  29 #include <babeltrace/babeltrace-internal.h>
  30 #include <babeltrace/compiler-internal.h>
  31 #include <babeltrace/object.h>
  32 #include <babeltrace/common-internal.h>
  33 #include <babeltrace/plugin/plugin-internal.h>
  34 #include <babeltrace/plugin/plugin-so-internal.h>
  35 #include <babeltrace/graph/component-class.h>
  36 #include <babeltrace/graph/component-class-internal.h>
  37 #include <babeltrace/types.h>
  38 #include <babeltrace/assert-internal.h>
  39 #include <babeltrace/assert-pre-internal.h>
  40 #include <glib.h>
  41 #include <unistd.h>
  42 #include <stdlib.h>
  43 #include <stdint.h>
  44 #include <inttypes.h>
  45 #include <sys/stat.h>
  46 #include <ftw.h>
  47 #include <pthread.h>
  48
  49 #define PYTHON_PLUGIN_PROVIDER_FILENAME "libbabeltrace-python-plugin-provider." G_MODULE_SUFFIX
  50 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME bt_plugin_python_create_all_from_file
  51 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR     TOSTRING(PYTHON_PLUGIN_PROVIDER_SYM_NAME)
  52
  53 #define APPEND_ALL_FROM_DIR_NFDOPEN_MAX 8
  54
  55 #ifdef BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT
  56 #include <babeltrace/plugin/python-plugin-provider-internal.h>
  57
  58 static
  59 struct bt_plugin_set *(*bt_plugin_python_create_all_from_file_sym)(const char *path) =
  60         bt_plugin_python_create_all_from_file;
  61
  62 static
  63 void init_python_plugin_provider(void) {}
  64 #else /* BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT */
  65 static GModule *python_plugin_provider_module;
  66 static
  67 struct bt_plugin_set *(*bt_plugin_python_create_all_from_file_sym)(const char *path);
  68
  69 static
  70 void init_python_plugin_provider(void) {
  71         if (bt_plugin_python_create_all_from_file_sym != NULL) {
  72                 return;
  73         }
  74
  75         BT_LOGD_STR("Loading Python plugin provider module.");
  76         python_plugin_provider_module =
  77                 g_module_open(PYTHON_PLUGIN_PROVIDER_FILENAME, 0);
  78         if (!python_plugin_provider_module) {
  79                 BT_LOGI("Cannot open `%s`: %s: continuing without Python plugin support.",
  80                         PYTHON_PLUGIN_PROVIDER_FILENAME, g_module_error());
  81                 return;
  82         }
  83
  84         if (!g_module_symbol(python_plugin_provider_module,
  85                         PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR,
  86                         (gpointer) &bt_plugin_python_create_all_from_file_sym)) {
  87                 BT_LOGI("Cannot find the Python plugin provider loading symbol: continuing without Python plugin support: "
  88                         "file=\"%s\", symbol=\"%s\"",
  89                         PYTHON_PLUGIN_PROVIDER_FILENAME,
  90                         PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR);
  91                 return;
  92         }
  93
  94         BT_LOGI("Loaded Python plugin provider module: addr=%p",
  95                 python_plugin_provider_module);
  96 }
  97
  98 __attribute__((destructor)) static
  99 void fini_python_plugin_provider(void) {
 100         if (python_plugin_provider_module) {
 101                 BT_LOGD("Unloading Python plugin provider module.");
 102
 103                 if (!g_module_close(python_plugin_provider_module)) {
 104                         BT_LOGE("Failed to close the Python plugin provider module: %s.",
 105                                 g_module_error());
 106                 }
 107
 108                 python_plugin_provider_module = NULL;
 109         }
 110 }
 111 #endif
 112
 113 uint64_t bt_plugin_set_get_plugin_count(struct bt_plugin_set *plugin_set)
 114 {
 115         BT_ASSERT_PRE_NON_NULL(plugin_set, "Plugin set");
 116         return (uint64_t) plugin_set->plugins->len;
 117 }
 118
 119 struct bt_plugin *bt_plugin_set_borrow_plugin_by_index(
 120                 struct bt_plugin_set *plugin_set,
 121                 uint64_t index)
 122 {
 123         BT_ASSERT_PRE_NON_NULL(plugin_set, "Plugin set");
 124         BT_ASSERT_PRE_VALID_INDEX(index, plugin_set->plugins->len);
 125         return g_ptr_array_index(plugin_set->plugins, index);
 126 }
 127
 128 struct bt_plugin_set *bt_plugin_create_all_from_static(void)
 129 {
 130         /* bt_plugin_so_create_all_from_static() logs errors */
 131         return bt_plugin_so_create_all_from_static();
 132 }
 133
 134 struct bt_plugin_set *bt_plugin_create_all_from_file(const char *path)
 135 {
 136         struct bt_plugin_set *plugin_set = NULL;
 137
 138         BT_ASSERT_PRE_NON_NULL(path, "Path");
 139         BT_LOGD("Creating plugins from file: path=\"%s\"", path);
 140
 141         /* Try shared object plugins */
 142         plugin_set = bt_plugin_so_create_all_from_file(path);
 143         if (plugin_set) {
 144                 goto end;
 145         }
 146
 147         /* Try Python plugins if support is available */
 148         init_python_plugin_provider();
 149         if (bt_plugin_python_create_all_from_file_sym) {
 150                 plugin_set = bt_plugin_python_create_all_from_file_sym(path);
 151                 if (plugin_set) {
 152                         goto end;
 153                 }
 154         }
 155
 156 end:
 157         if (plugin_set) {
 158                 BT_LOGD("Created %u plugins from file: "
 159                         "path=\"%s\", count=%u, plugin-set-addr=%p",
 160                         plugin_set->plugins->len, path,
 161                         plugin_set->plugins->len, plugin_set);
 162         } else {
 163                 BT_LOGD("Found no plugins in file: path=\"%s\"", path);
 164         }
 165
 166         return plugin_set;
 167 }
 168
 169 static void destroy_gstring(void *data)
 170 {
 171         g_string_free(data, TRUE);
 172 }
 173
 174 struct bt_plugin *bt_plugin_find(const char *plugin_name)
 175 {
 176         const char *system_plugin_dir;
 177         char *home_plugin_dir = NULL;
 178         const char *envvar;
 179         struct bt_plugin *plugin = NULL;
 180         struct bt_plugin_set *plugin_set = NULL;
 181         GPtrArray *dirs = NULL;
 182         int ret;
 183         size_t i, j;
 184
 185         BT_ASSERT_PRE_NON_NULL(plugin_name, "Name");
 186         BT_LOGD("Finding named plugin in standard directories and built-in plugins: "
 187                 "name=\"%s\"", plugin_name);
 188         dirs = g_ptr_array_new_with_free_func((GDestroyNotify) destroy_gstring);
 189         if (!dirs) {
 190                 BT_LOGE_STR("Failed to allocate a GPtrArray.");
 191                 goto end;
 192         }
 193
 194         /*
 195          * Search order is:
 196          *
 197          * 1. BABELTRACE_PLUGIN_PATH environment variable
 198          *    (colon-separated list of directories)
 199          * 2. ~/.local/lib/babeltrace/plugins
 200          * 3. Default system directory for Babeltrace plugins, usually
 201          *    /usr/lib/babeltrace/plugins or
 202          *    /usr/local/lib/babeltrace/plugins if installed
 203          *    locally
 204          * 4. Built-in plugins (static)
 205          *
 206          * Directories are searched non-recursively.
 207          */
 208         envvar = getenv("BABELTRACE_PLUGIN_PATH");
 209         if (envvar) {
 210                 ret = bt_common_append_plugin_path_dirs(envvar, dirs);
 211                 if (ret) {
 212                         BT_LOGE_STR("Failed to append plugin path to array of directories.");
 213                         goto end;
 214                 }
 215         }
 216
 217         home_plugin_dir = bt_common_get_home_plugin_path();
 218         if (home_plugin_dir) {
 219                 GString *home_plugin_dir_str =
 220                         g_string_new(home_plugin_dir);
 221
 222                 if (!home_plugin_dir_str) {
 223                         BT_LOGE_STR("Failed to allocate a GString.");
 224                         goto end;
 225                 }
 226
 227                 g_ptr_array_add(dirs, home_plugin_dir_str);
 228         }
 229
 230         system_plugin_dir = bt_common_get_system_plugin_path();
 231         if (system_plugin_dir) {
 232                 GString *system_plugin_dir_str =
 233                         g_string_new(system_plugin_dir);
 234
 235                 if (!system_plugin_dir_str) {
 236                         BT_LOGE_STR("Failed to allocate a GString.");
 237                         goto end;
 238                 }
 239
 240                 g_ptr_array_add(dirs, system_plugin_dir_str);
 241         }
 242
 243         for (i = 0; i < dirs->len; i++) {
 244                 GString *dir = g_ptr_array_index(dirs, i);
 245
 246                 BT_OBJECT_PUT_REF_AND_RESET(plugin_set);
 247
 248                 /*
 249                  * Skip this if the directory does not exist because
 250                  * bt_plugin_create_all_from_dir() would log a warning.
 251                  */
 252                 if (!g_file_test(dir->str, G_FILE_TEST_IS_DIR)) {
 253                         BT_LOGV("Skipping nonexistent directory path: "
 254                                 "path=\"%s\"", dir->str);
 255                         continue;
 256                 }
 257
 258                 /* bt_plugin_create_all_from_dir() logs details/errors */
 259                 plugin_set = bt_plugin_create_all_from_dir(dir->str, BT_FALSE);
 260                 if (!plugin_set) {
 261                         BT_LOGD("No plugins found in directory: path=\"%s\"",
 262                                 dir->str);
 263                         continue;
 264                 }
 265
 266                 for (j = 0; j < plugin_set->plugins->len; j++) {
 267                         struct bt_plugin *candidate_plugin =
 268                                 g_ptr_array_index(plugin_set->plugins, j);
 269
 270                         if (strcmp(bt_plugin_get_name(candidate_plugin),
 271                                         plugin_name) == 0) {
 272                                 BT_LOGD("Plugin found in directory: name=\"%s\", path=\"%s\"",
 273                                         plugin_name, dir->str);
 274                                 plugin = bt_object_get_ref(candidate_plugin);
 275                                 goto end;
 276                         }
 277                 }
 278
 279                 BT_LOGD("Plugin not found in directory: name=\"%s\", path=\"%s\"",
 280                         plugin_name, dir->str);
 281         }
 282
 283         bt_object_put_ref(plugin_set);
 284         plugin_set = bt_plugin_create_all_from_static();
 285         if (plugin_set) {
 286                 for (j = 0; j < plugin_set->plugins->len; j++) {
 287                         struct bt_plugin *candidate_plugin =
 288                                 g_ptr_array_index(plugin_set->plugins, j);
 289
 290                         if (strcmp(bt_plugin_get_name(candidate_plugin),
 291                                         plugin_name) == 0) {
 292                                 BT_LOGD("Plugin found in built-in plugins: "
 293                                         "name=\"%s\"", plugin_name);
 294                                 plugin = bt_object_get_ref(candidate_plugin);
 295                                 goto end;
 296                         }
 297                 }
 298         }
 299
 300 end:
 301         free(home_plugin_dir);
 302         bt_object_put_ref(plugin_set);
 303
 304         if (dirs) {
 305                 g_ptr_array_free(dirs, TRUE);
 306         }
 307
 308         if (plugin) {
 309                 BT_LIB_LOGD("Found plugin in standard directories and built-in plugins: "
 310                         "%!+l", plugin);
 311         } else {
 312                 BT_LOGD("No plugin found in standard directories and built-in plugins: "
 313                         "name=\"%s\"", plugin_name);
 314         }
 315
 316         return plugin;
 317 }
 318
 319 static struct {
 320         pthread_mutex_t lock;
 321         struct bt_plugin_set *plugin_set;
 322         bool recurse;
 323 } append_all_from_dir_info = {
 324         .lock = PTHREAD_MUTEX_INITIALIZER
 325 };
 326
 327 static
 328 int nftw_append_all_from_dir(const char *file, const struct stat *sb, int flag,
 329                 struct FTW *s)
 330 {
 331         int ret = 0;
 332         const char *name = file + s->base;
 333
 334         /* Check for recursion */
 335         if (!append_all_from_dir_info.recurse && s->level > 1) {
 336                 goto end;
 337         }
 338
 339         switch (flag) {
 340         case FTW_F:
 341         {
 342                 struct bt_plugin_set *plugins_from_file;
 343
 344                 if (name[0] == '.') {
 345                         /* Skip hidden files */
 346                         BT_LOGV("Skipping hidden file: path=\"%s\"", file);
 347                         goto end;
 348                 }
 349
 350                 plugins_from_file = bt_plugin_create_all_from_file(file);
 351
 352                 if (plugins_from_file) {
 353                         size_t j;
 354
 355                         for (j = 0; j < plugins_from_file->plugins->len; j++) {
 356                                 struct bt_plugin *plugin =
 357                                         g_ptr_array_index(plugins_from_file->plugins, j);
 358
 359                                 BT_LIB_LOGD("Adding plugin to plugin set: "
 360                                         "plugin-path=\"%s\", %![plugin-]+l",
 361                                         file, plugin);
 362                                 bt_plugin_set_add_plugin(append_all_from_dir_info.plugin_set, plugin);
 363                         }
 364
 365                         bt_object_put_ref(plugins_from_file);
 366                 }
 367                 break;
 368         }
 369         case FTW_DNR:
 370                 /* Continue to next file / directory. */
 371                 BT_LOGW("Cannot enter directory: continuing: path=\"%s\"", file);
 372                 break;
 373         case FTW_NS:
 374                 /* Continue to next file / directory. */
 375                 BT_LOGD("Cannot get file information: continuing: path=\"%s\"", file);
 376                 break;
 377         }
 378
 379 end:
 380         return ret;
 381 }
 382
 383 static
 384 enum bt_plugin_status bt_plugin_create_append_all_from_dir(
 385                 struct bt_plugin_set *plugin_set, const char *path,
 386                 bt_bool recurse)
 387 {
 388         int nftw_flags = FTW_PHYS;
 389         enum bt_plugin_status ret = BT_PLUGIN_STATUS_OK;
 390
 391         BT_ASSERT(plugin_set);
 392         BT_ASSERT(path);
 393         BT_ASSERT(strlen(path) < PATH_MAX);
 394         pthread_mutex_lock(&append_all_from_dir_info.lock);
 395         append_all_from_dir_info.plugin_set = plugin_set;
 396         append_all_from_dir_info.recurse = recurse;
 397         ret = nftw(path, nftw_append_all_from_dir,
 398                 APPEND_ALL_FROM_DIR_NFDOPEN_MAX, nftw_flags);
 399         pthread_mutex_unlock(&append_all_from_dir_info.lock);
 400         if (ret != 0) {
 401                 BT_LOGW_ERRNO("Cannot open directory", ": path=\"%s\"", path);
 402                 ret = BT_PLUGIN_STATUS_ERROR;
 403         }
 404
 405         return ret;
 406 }
 407
 408 struct bt_plugin_set *bt_plugin_create_all_from_dir(const char *path,
 409                 bt_bool recurse)
 410 {
 411         struct bt_plugin_set *plugin_set;
 412         enum bt_plugin_status status;
 413
 414         BT_LOGD("Creating all plugins in directory: path=\"%s\", recurse=%d",
 415                 path, recurse);
 416         plugin_set = bt_plugin_set_create();
 417         if (!plugin_set) {
 418                 BT_LOGE_STR("Cannot create empty plugin set.");
 419                 goto error;
 420         }
 421
 422         /* Append found plugins to array */
 423         status = bt_plugin_create_append_all_from_dir(plugin_set, path,
 424                 recurse);
 425         if (status < 0) {
 426                 BT_LOGW("Cannot append plugins found in directory: "
 427                         "path=\"%s\", status=%s",
 428                         path, bt_plugin_status_string(status));
 429                 goto error;
 430         }
 431
 432         BT_LOGD("Created %u plugins from directory: count=%u, path=\"%s\"",
 433                 plugin_set->plugins->len, plugin_set->plugins->len, path);
 434         goto end;
 435
 436 error:
 437         BT_OBJECT_PUT_REF_AND_RESET(plugin_set);
 438
 439 end:
 440         return plugin_set;
 441 }
 442
 443 const char *bt_plugin_get_name(struct bt_plugin *plugin)
 444 {
 445         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 446         return plugin->info.name_set ? plugin->info.name->str : NULL;
 447 }
 448
 449 const char *bt_plugin_get_author(struct bt_plugin *plugin)
 450 {
 451         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 452         return plugin->info.author_set ? plugin->info.author->str : NULL;
 453 }
 454
 455 const char *bt_plugin_get_license(struct bt_plugin *plugin)
 456 {
 457         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 458         return plugin->info.license_set ? plugin->info.license->str : NULL;
 459 }
 460
 461 const char *bt_plugin_get_path(struct bt_plugin *plugin)
 462 {
 463         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 464         return plugin->info.path_set ? plugin->info.path->str : NULL;
 465 }
 466
 467 const char *bt_plugin_get_description(struct bt_plugin *plugin)
 468 {
 469         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 470         return plugin->info.description_set ?
 471                 plugin->info.description->str : NULL;
 472 }
 473
 474 enum bt_property_availability bt_plugin_get_version(struct bt_plugin *plugin,
 475                 unsigned int *major, unsigned int *minor, unsigned int *patch,
 476                 const char **extra)
 477 {
 478         enum bt_property_availability avail =
 479                 BT_PROPERTY_AVAILABILITY_AVAILABLE;
 480
 481         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 482
 483         if (!plugin->info.version_set) {
 484                 BT_LIB_LOGV("Plugin's version is not set: %!+l", plugin);
 485                 avail = BT_PROPERTY_AVAILABILITY_NOT_AVAILABLE;
 486                 goto end;
 487         }
 488
 489         if (major) {
 490                 *major = plugin->info.version.major;
 491         }
 492
 493         if (minor) {
 494                 *minor = plugin->info.version.minor;
 495         }
 496
 497         if (patch) {
 498                 *patch = plugin->info.version.patch;
 499         }
 500
 501         if (extra) {
 502                 *extra = plugin->info.version.extra->str;
 503         }
 504
 505 end:
 506         return avail;
 507 }
 508
 509 uint64_t bt_plugin_get_source_component_class_count(struct bt_plugin *plugin)
 510 {
 511         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 512         return (uint64_t) plugin->src_comp_classes->len;
 513 }
 514
 515 uint64_t bt_plugin_get_filter_component_class_count(struct bt_plugin *plugin)
 516 {
 517         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 518         return (uint64_t) plugin->flt_comp_classes->len;
 519 }
 520
 521 uint64_t bt_plugin_get_sink_component_class_count(struct bt_plugin *plugin)
 522 {
 523         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 524         return (uint64_t) plugin->sink_comp_classes->len;
 525 }
 526
 527 static inline
 528 struct bt_component_class *borrow_component_class_by_index(
 529                 struct bt_plugin *plugin, GPtrArray *comp_classes,
 530                 uint64_t index)
 531 {
 532         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 533         BT_ASSERT_PRE_VALID_INDEX(index, comp_classes->len);
 534         return g_ptr_array_index(comp_classes, index);
 535 }
 536
 537
 538 struct bt_component_class_source *
 539 bt_plugin_borrow_source_component_class_by_index(
 540                 struct bt_plugin *plugin, uint64_t index)
 541 {
 542         return (void *) borrow_component_class_by_index(plugin,
 543                 plugin->src_comp_classes, index);
 544 }
 545
 546 struct bt_component_class_filter *
 547 bt_plugin_borrow_filter_component_class_by_index(
 548                 struct bt_plugin *plugin, uint64_t index)
 549 {
 550         return (void *) borrow_component_class_by_index(plugin,
 551                 plugin->flt_comp_classes, index);
 552 }
 553
 554 struct bt_component_class_sink *
 555 bt_plugin_borrow_sink_component_class_by_index(
 556                 struct bt_plugin *plugin, uint64_t index)
 557 {
 558         return (void *) borrow_component_class_by_index(plugin,
 559                 plugin->sink_comp_classes, index);
 560 }
 561
 562 static inline
 563 struct bt_component_class *borrow_component_class_by_name(
 564                 struct bt_plugin *plugin, GPtrArray *comp_classes,
 565                 const char *name)
 566 {
 567         struct bt_component_class *comp_class = NULL;
 568         size_t i;
 569
 570         BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
 571         BT_ASSERT_PRE_NON_NULL(name, "Name");
 572
 573         for (i = 0; i < comp_classes->len; i++) {
 574                 struct bt_component_class *comp_class_candidate =
 575                         g_ptr_array_index(comp_classes, i);
 576                 const char *comp_class_cand_name =
 577                         bt_component_class_get_name(comp_class_candidate);
 578
 579                 BT_ASSERT(comp_class_cand_name);
 580
 581                 if (strcmp(name, comp_class_cand_name) == 0) {
 582                         comp_class = comp_class_candidate;
 583                         break;
 584                 }
 585         }
 586
 587         return comp_class;
 588 }
 589
 590 struct bt_component_class_source *
 591 bt_plugin_borrow_source_component_class_by_name(struct bt_plugin *plugin,
 592                 const char *name)
 593 {
 594         return (void *) borrow_component_class_by_name(plugin,
 595                 plugin->src_comp_classes, name);
 596 }
 597
 598 struct bt_component_class_filter *
 599 bt_plugin_borrow_filter_component_class_by_name(struct bt_plugin *plugin,
 600                 const char *name)
 601 {
 602         return (void *) borrow_component_class_by_name(plugin,
 603                 plugin->flt_comp_classes, name);
 604 }
 605
 606 struct bt_component_class_sink *
 607 bt_plugin_borrow_sink_component_class_by_name(struct bt_plugin *plugin,
 608                 const char *name)
 609 {
 610         return (void *) borrow_component_class_by_name(plugin,
 611                 plugin->sink_comp_classes, name);
 612 }