| 1 | /* |
| 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include "lttng/action/action.h" |
| 9 | #include "lttng/trigger/trigger-internal.h" |
| 10 | #define _LGPL_SOURCE |
| 11 | #include <urcu.h> |
| 12 | #include <urcu/rculfhash.h> |
| 13 | |
| 14 | #include <common/defaults.h> |
| 15 | #include <common/error.h> |
| 16 | #include <common/futex.h> |
| 17 | #include <common/unix.h> |
| 18 | #include <common/dynamic-buffer.h> |
| 19 | #include <common/hashtable/utils.h> |
| 20 | #include <common/sessiond-comm/sessiond-comm.h> |
| 21 | #include <common/macros.h> |
| 22 | #include <lttng/condition/condition.h> |
| 23 | #include <lttng/action/action-internal.h> |
| 24 | #include <lttng/notification/notification-internal.h> |
| 25 | #include <lttng/condition/condition-internal.h> |
| 26 | #include <lttng/condition/buffer-usage-internal.h> |
| 27 | #include <lttng/condition/session-consumed-size-internal.h> |
| 28 | #include <lttng/condition/session-rotation-internal.h> |
| 29 | #include <lttng/notification/channel-internal.h> |
| 30 | #include <lttng/trigger/trigger-internal.h> |
| 31 | |
| 32 | #include <time.h> |
| 33 | #include <unistd.h> |
| 34 | #include <assert.h> |
| 35 | #include <inttypes.h> |
| 36 | #include <fcntl.h> |
| 37 | |
| 38 | #include "notification-thread.h" |
| 39 | #include "notification-thread-events.h" |
| 40 | #include "notification-thread-commands.h" |
| 41 | #include "lttng-sessiond.h" |
| 42 | #include "kernel.h" |
| 43 | |
| 44 | #define CLIENT_POLL_MASK_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP) |
| 45 | #define CLIENT_POLL_MASK_IN_OUT (CLIENT_POLL_MASK_IN | LPOLLOUT) |
| 46 | |
| 47 | enum lttng_object_type { |
| 48 | LTTNG_OBJECT_TYPE_UNKNOWN, |
| 49 | LTTNG_OBJECT_TYPE_NONE, |
| 50 | LTTNG_OBJECT_TYPE_CHANNEL, |
| 51 | LTTNG_OBJECT_TYPE_SESSION, |
| 52 | }; |
| 53 | |
| 54 | struct lttng_trigger_list_element { |
| 55 | /* No ownership of the trigger object is assumed. */ |
| 56 | struct lttng_trigger *trigger; |
| 57 | struct cds_list_head node; |
| 58 | }; |
| 59 | |
| 60 | struct lttng_channel_trigger_list { |
| 61 | struct channel_key channel_key; |
| 62 | /* List of struct lttng_trigger_list_element. */ |
| 63 | struct cds_list_head list; |
| 64 | /* Node in the channel_triggers_ht */ |
| 65 | struct cds_lfht_node channel_triggers_ht_node; |
| 66 | /* call_rcu delayed reclaim. */ |
| 67 | struct rcu_head rcu_node; |
| 68 | }; |
| 69 | |
| 70 | /* |
| 71 | * List of triggers applying to a given session. |
| 72 | * |
| 73 | * See: |
| 74 | * - lttng_session_trigger_list_create() |
| 75 | * - lttng_session_trigger_list_build() |
| 76 | * - lttng_session_trigger_list_destroy() |
| 77 | * - lttng_session_trigger_list_add() |
| 78 | */ |
| 79 | struct lttng_session_trigger_list { |
| 80 | /* |
| 81 | * Not owned by this; points to the session_info structure's |
| 82 | * session name. |
| 83 | */ |
| 84 | const char *session_name; |
| 85 | /* List of struct lttng_trigger_list_element. */ |
| 86 | struct cds_list_head list; |
| 87 | /* Node in the session_triggers_ht */ |
| 88 | struct cds_lfht_node session_triggers_ht_node; |
| 89 | /* |
| 90 | * Weak reference to the notification system's session triggers |
| 91 | * hashtable. |
| 92 | * |
| 93 | * The session trigger list structure structure is owned by |
| 94 | * the session's session_info. |
| 95 | * |
| 96 | * The session_info is kept alive the the channel_infos holding a |
| 97 | * reference to it (reference counting). When those channels are |
| 98 | * destroyed (at runtime or on teardown), the reference they hold |
| 99 | * to the session_info are released. On destruction of session_info, |
| 100 | * session_info_destroy() will remove the list of triggers applying |
| 101 | * to this session from the notification system's state. |
| 102 | * |
| 103 | * This implies that the session_triggers_ht must be destroyed |
| 104 | * after the channels. |
| 105 | */ |
| 106 | struct cds_lfht *session_triggers_ht; |
| 107 | /* Used for delayed RCU reclaim. */ |
| 108 | struct rcu_head rcu_node; |
| 109 | }; |
| 110 | |
| 111 | struct lttng_trigger_ht_element { |
| 112 | struct lttng_trigger *trigger; |
| 113 | struct cds_lfht_node node; |
| 114 | struct cds_lfht_node node_by_name_uid; |
| 115 | /* call_rcu delayed reclaim. */ |
| 116 | struct rcu_head rcu_node; |
| 117 | }; |
| 118 | |
| 119 | struct lttng_condition_list_element { |
| 120 | struct lttng_condition *condition; |
| 121 | struct cds_list_head node; |
| 122 | }; |
| 123 | |
| 124 | struct channel_state_sample { |
| 125 | struct channel_key key; |
| 126 | struct cds_lfht_node channel_state_ht_node; |
| 127 | uint64_t highest_usage; |
| 128 | uint64_t lowest_usage; |
| 129 | uint64_t channel_total_consumed; |
| 130 | /* call_rcu delayed reclaim. */ |
| 131 | struct rcu_head rcu_node; |
| 132 | }; |
| 133 | |
| 134 | static unsigned long hash_channel_key(struct channel_key *key); |
| 135 | static int evaluate_buffer_condition(const struct lttng_condition *condition, |
| 136 | struct lttng_evaluation **evaluation, |
| 137 | const struct notification_thread_state *state, |
| 138 | const struct channel_state_sample *previous_sample, |
| 139 | const struct channel_state_sample *latest_sample, |
| 140 | uint64_t previous_session_consumed_total, |
| 141 | uint64_t latest_session_consumed_total, |
| 142 | struct channel_info *channel_info); |
| 143 | static |
| 144 | int send_evaluation_to_clients(const struct lttng_trigger *trigger, |
| 145 | const struct lttng_evaluation *evaluation, |
| 146 | struct notification_client_list *client_list, |
| 147 | struct notification_thread_state *state, |
| 148 | uid_t channel_uid, gid_t channel_gid); |
| 149 | |
| 150 | |
| 151 | /* session_info API */ |
| 152 | static |
| 153 | void session_info_destroy(void *_data); |
| 154 | static |
| 155 | void session_info_get(struct session_info *session_info); |
| 156 | static |
| 157 | void session_info_put(struct session_info *session_info); |
| 158 | static |
| 159 | struct session_info *session_info_create(const char *name, |
| 160 | uid_t uid, gid_t gid, |
| 161 | struct lttng_session_trigger_list *trigger_list, |
| 162 | struct cds_lfht *sessions_ht); |
| 163 | static |
| 164 | void session_info_add_channel(struct session_info *session_info, |
| 165 | struct channel_info *channel_info); |
| 166 | static |
| 167 | void session_info_remove_channel(struct session_info *session_info, |
| 168 | struct channel_info *channel_info); |
| 169 | |
| 170 | /* lttng_session_trigger_list API */ |
| 171 | static |
| 172 | struct lttng_session_trigger_list *lttng_session_trigger_list_create( |
| 173 | const char *session_name, |
| 174 | struct cds_lfht *session_triggers_ht); |
| 175 | static |
| 176 | struct lttng_session_trigger_list *lttng_session_trigger_list_build( |
| 177 | const struct notification_thread_state *state, |
| 178 | const char *session_name); |
| 179 | static |
| 180 | void lttng_session_trigger_list_destroy( |
| 181 | struct lttng_session_trigger_list *list); |
| 182 | static |
| 183 | int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list, |
| 184 | struct lttng_trigger *trigger); |
| 185 | |
| 186 | static |
| 187 | int client_handle_transmission_status( |
| 188 | struct notification_client *client, |
| 189 | enum client_transmission_status transmission_status, |
| 190 | struct notification_thread_state *state); |
| 191 | |
| 192 | static |
| 193 | void free_lttng_trigger_ht_element_rcu(struct rcu_head *node); |
| 194 | |
| 195 | static |
| 196 | int match_client_socket(struct cds_lfht_node *node, const void *key) |
| 197 | { |
| 198 | /* This double-cast is intended to supress pointer-to-cast warning. */ |
| 199 | const int socket = (int) (intptr_t) key; |
| 200 | const struct notification_client *client = caa_container_of(node, |
| 201 | struct notification_client, client_socket_ht_node); |
| 202 | |
| 203 | return client->socket == socket; |
| 204 | } |
| 205 | |
| 206 | static |
| 207 | int match_client_id(struct cds_lfht_node *node, const void *key) |
| 208 | { |
| 209 | /* This double-cast is intended to supress pointer-to-cast warning. */ |
| 210 | const notification_client_id id = *((notification_client_id *) key); |
| 211 | const struct notification_client *client = caa_container_of( |
| 212 | node, struct notification_client, client_id_ht_node); |
| 213 | |
| 214 | return client->id == id; |
| 215 | } |
| 216 | |
| 217 | static |
| 218 | int match_channel_trigger_list(struct cds_lfht_node *node, const void *key) |
| 219 | { |
| 220 | struct channel_key *channel_key = (struct channel_key *) key; |
| 221 | struct lttng_channel_trigger_list *trigger_list; |
| 222 | |
| 223 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 224 | channel_triggers_ht_node); |
| 225 | |
| 226 | return !!((channel_key->key == trigger_list->channel_key.key) && |
| 227 | (channel_key->domain == trigger_list->channel_key.domain)); |
| 228 | } |
| 229 | |
| 230 | static |
| 231 | int match_session_trigger_list(struct cds_lfht_node *node, const void *key) |
| 232 | { |
| 233 | const char *session_name = (const char *) key; |
| 234 | struct lttng_session_trigger_list *trigger_list; |
| 235 | |
| 236 | trigger_list = caa_container_of(node, struct lttng_session_trigger_list, |
| 237 | session_triggers_ht_node); |
| 238 | |
| 239 | return !!(strcmp(trigger_list->session_name, session_name) == 0); |
| 240 | } |
| 241 | |
| 242 | static |
| 243 | int match_channel_state_sample(struct cds_lfht_node *node, const void *key) |
| 244 | { |
| 245 | struct channel_key *channel_key = (struct channel_key *) key; |
| 246 | struct channel_state_sample *sample; |
| 247 | |
| 248 | sample = caa_container_of(node, struct channel_state_sample, |
| 249 | channel_state_ht_node); |
| 250 | |
| 251 | return !!((channel_key->key == sample->key.key) && |
| 252 | (channel_key->domain == sample->key.domain)); |
| 253 | } |
| 254 | |
| 255 | static |
| 256 | int match_channel_info(struct cds_lfht_node *node, const void *key) |
| 257 | { |
| 258 | struct channel_key *channel_key = (struct channel_key *) key; |
| 259 | struct channel_info *channel_info; |
| 260 | |
| 261 | channel_info = caa_container_of(node, struct channel_info, |
| 262 | channels_ht_node); |
| 263 | |
| 264 | return !!((channel_key->key == channel_info->key.key) && |
| 265 | (channel_key->domain == channel_info->key.domain)); |
| 266 | } |
| 267 | |
| 268 | static |
| 269 | int match_trigger(struct cds_lfht_node *node, const void *key) |
| 270 | { |
| 271 | struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; |
| 272 | struct lttng_trigger_ht_element *trigger_ht_element; |
| 273 | |
| 274 | trigger_ht_element = caa_container_of(node, struct lttng_trigger_ht_element, |
| 275 | node); |
| 276 | |
| 277 | return !!lttng_trigger_is_equal(trigger_key, trigger_ht_element->trigger); |
| 278 | } |
| 279 | |
| 280 | static |
| 281 | int match_client_list_condition(struct cds_lfht_node *node, const void *key) |
| 282 | { |
| 283 | struct lttng_condition *condition_key = (struct lttng_condition *) key; |
| 284 | struct notification_client_list *client_list; |
| 285 | const struct lttng_condition *condition; |
| 286 | |
| 287 | assert(condition_key); |
| 288 | |
| 289 | client_list = caa_container_of(node, struct notification_client_list, |
| 290 | notification_trigger_clients_ht_node); |
| 291 | condition = lttng_trigger_get_const_condition(client_list->trigger); |
| 292 | |
| 293 | return !!lttng_condition_is_equal(condition_key, condition); |
| 294 | } |
| 295 | |
| 296 | static |
| 297 | int match_session(struct cds_lfht_node *node, const void *key) |
| 298 | { |
| 299 | const char *name = key; |
| 300 | struct session_info *session_info = caa_container_of( |
| 301 | node, struct session_info, sessions_ht_node); |
| 302 | |
| 303 | return !strcmp(session_info->name, name); |
| 304 | } |
| 305 | |
| 306 | /* |
| 307 | * Match trigger based on name and credentials only. |
| 308 | * Name duplication is NOT allowed for the same uid. |
| 309 | */ |
| 310 | static |
| 311 | int match_trigger_by_name_uid(struct cds_lfht_node *node, |
| 312 | const void *key) |
| 313 | { |
| 314 | bool match = false; |
| 315 | const char *name; |
| 316 | const char *key_name; |
| 317 | enum lttng_trigger_status status; |
| 318 | const struct lttng_credentials *key_creds; |
| 319 | const struct lttng_credentials *node_creds; |
| 320 | const struct lttng_trigger *trigger_key = |
| 321 | (const struct lttng_trigger *) key; |
| 322 | const struct lttng_trigger_ht_element *trigger_ht_element = |
| 323 | caa_container_of(node, |
| 324 | struct lttng_trigger_ht_element, |
| 325 | node_by_name_uid); |
| 326 | |
| 327 | status = lttng_trigger_get_name(trigger_ht_element->trigger, &name); |
| 328 | assert(status == LTTNG_TRIGGER_STATUS_OK); |
| 329 | |
| 330 | status = lttng_trigger_get_name(trigger_key, &key_name); |
| 331 | assert(status == LTTNG_TRIGGER_STATUS_OK); |
| 332 | |
| 333 | /* Compare the names. */ |
| 334 | if (strcmp(name, key_name) != 0) { |
| 335 | goto end; |
| 336 | } |
| 337 | |
| 338 | /* Compare the owners' UIDs. */ |
| 339 | key_creds = lttng_trigger_get_credentials(trigger_key); |
| 340 | node_creds = lttng_trigger_get_credentials(trigger_ht_element->trigger); |
| 341 | |
| 342 | match = lttng_credentials_is_equal_uid(key_creds, node_creds); |
| 343 | |
| 344 | end: |
| 345 | return match; |
| 346 | } |
| 347 | |
| 348 | /* |
| 349 | * Hash trigger based on name and credentials only. |
| 350 | */ |
| 351 | static |
| 352 | unsigned long hash_trigger_by_name_uid(const struct lttng_trigger *trigger) |
| 353 | { |
| 354 | unsigned long hash = 0; |
| 355 | const struct lttng_credentials *trigger_creds; |
| 356 | const char *trigger_name; |
| 357 | enum lttng_trigger_status status; |
| 358 | |
| 359 | status = lttng_trigger_get_name(trigger, &trigger_name); |
| 360 | if (status == LTTNG_TRIGGER_STATUS_OK) { |
| 361 | hash = hash_key_str(trigger_name, lttng_ht_seed); |
| 362 | } |
| 363 | |
| 364 | trigger_creds = lttng_trigger_get_credentials(trigger); |
| 365 | hash ^= hash_key_ulong((void *) (unsigned long) LTTNG_OPTIONAL_GET(trigger_creds->uid), |
| 366 | lttng_ht_seed); |
| 367 | |
| 368 | return hash; |
| 369 | } |
| 370 | |
| 371 | static |
| 372 | unsigned long lttng_condition_buffer_usage_hash( |
| 373 | const struct lttng_condition *_condition) |
| 374 | { |
| 375 | unsigned long hash; |
| 376 | unsigned long condition_type; |
| 377 | struct lttng_condition_buffer_usage *condition; |
| 378 | |
| 379 | condition = container_of(_condition, |
| 380 | struct lttng_condition_buffer_usage, parent); |
| 381 | |
| 382 | condition_type = (unsigned long) condition->parent.type; |
| 383 | hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); |
| 384 | if (condition->session_name) { |
| 385 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); |
| 386 | } |
| 387 | if (condition->channel_name) { |
| 388 | hash ^= hash_key_str(condition->channel_name, lttng_ht_seed); |
| 389 | } |
| 390 | if (condition->domain.set) { |
| 391 | hash ^= hash_key_ulong( |
| 392 | (void *) condition->domain.type, |
| 393 | lttng_ht_seed); |
| 394 | } |
| 395 | if (condition->threshold_ratio.set) { |
| 396 | uint64_t val; |
| 397 | |
| 398 | val = condition->threshold_ratio.value * (double) UINT32_MAX; |
| 399 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 400 | } else if (condition->threshold_bytes.set) { |
| 401 | uint64_t val; |
| 402 | |
| 403 | val = condition->threshold_bytes.value; |
| 404 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 405 | } |
| 406 | return hash; |
| 407 | } |
| 408 | |
| 409 | static |
| 410 | unsigned long lttng_condition_session_consumed_size_hash( |
| 411 | const struct lttng_condition *_condition) |
| 412 | { |
| 413 | unsigned long hash; |
| 414 | unsigned long condition_type = |
| 415 | (unsigned long) LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE; |
| 416 | struct lttng_condition_session_consumed_size *condition; |
| 417 | uint64_t val; |
| 418 | |
| 419 | condition = container_of(_condition, |
| 420 | struct lttng_condition_session_consumed_size, parent); |
| 421 | |
| 422 | hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); |
| 423 | if (condition->session_name) { |
| 424 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); |
| 425 | } |
| 426 | val = condition->consumed_threshold_bytes.value; |
| 427 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 428 | return hash; |
| 429 | } |
| 430 | |
| 431 | static |
| 432 | unsigned long lttng_condition_session_rotation_hash( |
| 433 | const struct lttng_condition *_condition) |
| 434 | { |
| 435 | unsigned long hash, condition_type; |
| 436 | struct lttng_condition_session_rotation *condition; |
| 437 | |
| 438 | condition = container_of(_condition, |
| 439 | struct lttng_condition_session_rotation, parent); |
| 440 | condition_type = (unsigned long) condition->parent.type; |
| 441 | hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); |
| 442 | assert(condition->session_name); |
| 443 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); |
| 444 | return hash; |
| 445 | } |
| 446 | |
| 447 | /* |
| 448 | * The lttng_condition hashing code is kept in this file (rather than |
| 449 | * condition.c) since it makes use of GPLv2 code (hashtable utils), which we |
| 450 | * don't want to link in liblttng-ctl. |
| 451 | */ |
| 452 | static |
| 453 | unsigned long lttng_condition_hash(const struct lttng_condition *condition) |
| 454 | { |
| 455 | switch (condition->type) { |
| 456 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 457 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 458 | return lttng_condition_buffer_usage_hash(condition); |
| 459 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 460 | return lttng_condition_session_consumed_size_hash(condition); |
| 461 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 462 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 463 | return lttng_condition_session_rotation_hash(condition); |
| 464 | default: |
| 465 | ERR("[notification-thread] Unexpected condition type caught"); |
| 466 | abort(); |
| 467 | } |
| 468 | } |
| 469 | |
| 470 | static |
| 471 | unsigned long hash_channel_key(struct channel_key *key) |
| 472 | { |
| 473 | unsigned long key_hash = hash_key_u64(&key->key, lttng_ht_seed); |
| 474 | unsigned long domain_hash = hash_key_ulong( |
| 475 | (void *) (unsigned long) key->domain, lttng_ht_seed); |
| 476 | |
| 477 | return key_hash ^ domain_hash; |
| 478 | } |
| 479 | |
| 480 | static |
| 481 | unsigned long hash_client_socket(int socket) |
| 482 | { |
| 483 | return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed); |
| 484 | } |
| 485 | |
| 486 | static |
| 487 | unsigned long hash_client_id(notification_client_id id) |
| 488 | { |
| 489 | return hash_key_u64(&id, lttng_ht_seed); |
| 490 | } |
| 491 | |
| 492 | /* |
| 493 | * Get the type of object to which a given condition applies. Bindings let |
| 494 | * the notification system evaluate a trigger's condition when a given |
| 495 | * object's state is updated. |
| 496 | * |
| 497 | * For instance, a condition bound to a channel will be evaluated everytime |
| 498 | * the channel's state is changed by a channel monitoring sample. |
| 499 | */ |
| 500 | static |
| 501 | enum lttng_object_type get_condition_binding_object( |
| 502 | const struct lttng_condition *condition) |
| 503 | { |
| 504 | switch (lttng_condition_get_type(condition)) { |
| 505 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 506 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 507 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 508 | return LTTNG_OBJECT_TYPE_CHANNEL; |
| 509 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 510 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 511 | return LTTNG_OBJECT_TYPE_SESSION; |
| 512 | default: |
| 513 | return LTTNG_OBJECT_TYPE_UNKNOWN; |
| 514 | } |
| 515 | } |
| 516 | |
| 517 | static |
| 518 | void free_channel_info_rcu(struct rcu_head *node) |
| 519 | { |
| 520 | free(caa_container_of(node, struct channel_info, rcu_node)); |
| 521 | } |
| 522 | |
| 523 | static |
| 524 | void channel_info_destroy(struct channel_info *channel_info) |
| 525 | { |
| 526 | if (!channel_info) { |
| 527 | return; |
| 528 | } |
| 529 | |
| 530 | if (channel_info->session_info) { |
| 531 | session_info_remove_channel(channel_info->session_info, |
| 532 | channel_info); |
| 533 | session_info_put(channel_info->session_info); |
| 534 | } |
| 535 | if (channel_info->name) { |
| 536 | free(channel_info->name); |
| 537 | } |
| 538 | call_rcu(&channel_info->rcu_node, free_channel_info_rcu); |
| 539 | } |
| 540 | |
| 541 | static |
| 542 | void free_session_info_rcu(struct rcu_head *node) |
| 543 | { |
| 544 | free(caa_container_of(node, struct session_info, rcu_node)); |
| 545 | } |
| 546 | |
| 547 | /* Don't call directly, use the ref-counting mechanism. */ |
| 548 | static |
| 549 | void session_info_destroy(void *_data) |
| 550 | { |
| 551 | struct session_info *session_info = _data; |
| 552 | int ret; |
| 553 | |
| 554 | assert(session_info); |
| 555 | if (session_info->channel_infos_ht) { |
| 556 | ret = cds_lfht_destroy(session_info->channel_infos_ht, NULL); |
| 557 | if (ret) { |
| 558 | ERR("[notification-thread] Failed to destroy channel information hash table"); |
| 559 | } |
| 560 | } |
| 561 | lttng_session_trigger_list_destroy(session_info->trigger_list); |
| 562 | |
| 563 | rcu_read_lock(); |
| 564 | cds_lfht_del(session_info->sessions_ht, |
| 565 | &session_info->sessions_ht_node); |
| 566 | rcu_read_unlock(); |
| 567 | free(session_info->name); |
| 568 | call_rcu(&session_info->rcu_node, free_session_info_rcu); |
| 569 | } |
| 570 | |
| 571 | static |
| 572 | void session_info_get(struct session_info *session_info) |
| 573 | { |
| 574 | if (!session_info) { |
| 575 | return; |
| 576 | } |
| 577 | lttng_ref_get(&session_info->ref); |
| 578 | } |
| 579 | |
| 580 | static |
| 581 | void session_info_put(struct session_info *session_info) |
| 582 | { |
| 583 | if (!session_info) { |
| 584 | return; |
| 585 | } |
| 586 | lttng_ref_put(&session_info->ref); |
| 587 | } |
| 588 | |
| 589 | static |
| 590 | struct session_info *session_info_create(const char *name, uid_t uid, gid_t gid, |
| 591 | struct lttng_session_trigger_list *trigger_list, |
| 592 | struct cds_lfht *sessions_ht) |
| 593 | { |
| 594 | struct session_info *session_info; |
| 595 | |
| 596 | assert(name); |
| 597 | |
| 598 | session_info = zmalloc(sizeof(*session_info)); |
| 599 | if (!session_info) { |
| 600 | goto end; |
| 601 | } |
| 602 | lttng_ref_init(&session_info->ref, session_info_destroy); |
| 603 | |
| 604 | session_info->channel_infos_ht = cds_lfht_new(DEFAULT_HT_SIZE, |
| 605 | 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 606 | if (!session_info->channel_infos_ht) { |
| 607 | goto error; |
| 608 | } |
| 609 | |
| 610 | cds_lfht_node_init(&session_info->sessions_ht_node); |
| 611 | session_info->name = strdup(name); |
| 612 | if (!session_info->name) { |
| 613 | goto error; |
| 614 | } |
| 615 | session_info->uid = uid; |
| 616 | session_info->gid = gid; |
| 617 | session_info->trigger_list = trigger_list; |
| 618 | session_info->sessions_ht = sessions_ht; |
| 619 | end: |
| 620 | return session_info; |
| 621 | error: |
| 622 | session_info_put(session_info); |
| 623 | return NULL; |
| 624 | } |
| 625 | |
| 626 | static |
| 627 | void session_info_add_channel(struct session_info *session_info, |
| 628 | struct channel_info *channel_info) |
| 629 | { |
| 630 | rcu_read_lock(); |
| 631 | cds_lfht_add(session_info->channel_infos_ht, |
| 632 | hash_channel_key(&channel_info->key), |
| 633 | &channel_info->session_info_channels_ht_node); |
| 634 | rcu_read_unlock(); |
| 635 | } |
| 636 | |
| 637 | static |
| 638 | void session_info_remove_channel(struct session_info *session_info, |
| 639 | struct channel_info *channel_info) |
| 640 | { |
| 641 | rcu_read_lock(); |
| 642 | cds_lfht_del(session_info->channel_infos_ht, |
| 643 | &channel_info->session_info_channels_ht_node); |
| 644 | rcu_read_unlock(); |
| 645 | } |
| 646 | |
| 647 | static |
| 648 | struct channel_info *channel_info_create(const char *channel_name, |
| 649 | struct channel_key *channel_key, uint64_t channel_capacity, |
| 650 | struct session_info *session_info) |
| 651 | { |
| 652 | struct channel_info *channel_info = zmalloc(sizeof(*channel_info)); |
| 653 | |
| 654 | if (!channel_info) { |
| 655 | goto end; |
| 656 | } |
| 657 | |
| 658 | cds_lfht_node_init(&channel_info->channels_ht_node); |
| 659 | cds_lfht_node_init(&channel_info->session_info_channels_ht_node); |
| 660 | memcpy(&channel_info->key, channel_key, sizeof(*channel_key)); |
| 661 | channel_info->capacity = channel_capacity; |
| 662 | |
| 663 | channel_info->name = strdup(channel_name); |
| 664 | if (!channel_info->name) { |
| 665 | goto error; |
| 666 | } |
| 667 | |
| 668 | /* |
| 669 | * Set the references between session and channel infos: |
| 670 | * - channel_info holds a strong reference to session_info |
| 671 | * - session_info holds a weak reference to channel_info |
| 672 | */ |
| 673 | session_info_get(session_info); |
| 674 | session_info_add_channel(session_info, channel_info); |
| 675 | channel_info->session_info = session_info; |
| 676 | end: |
| 677 | return channel_info; |
| 678 | error: |
| 679 | channel_info_destroy(channel_info); |
| 680 | return NULL; |
| 681 | } |
| 682 | |
| 683 | LTTNG_HIDDEN |
| 684 | bool notification_client_list_get(struct notification_client_list *list) |
| 685 | { |
| 686 | return urcu_ref_get_unless_zero(&list->ref); |
| 687 | } |
| 688 | |
| 689 | static |
| 690 | void free_notification_client_list_rcu(struct rcu_head *node) |
| 691 | { |
| 692 | free(caa_container_of(node, struct notification_client_list, |
| 693 | rcu_node)); |
| 694 | } |
| 695 | |
| 696 | static |
| 697 | void notification_client_list_release(struct urcu_ref *list_ref) |
| 698 | { |
| 699 | struct notification_client_list *list = |
| 700 | container_of(list_ref, typeof(*list), ref); |
| 701 | struct notification_client_list_element *client_list_element, *tmp; |
| 702 | |
| 703 | if (list->notification_trigger_clients_ht) { |
| 704 | rcu_read_lock(); |
| 705 | cds_lfht_del(list->notification_trigger_clients_ht, |
| 706 | &list->notification_trigger_clients_ht_node); |
| 707 | rcu_read_unlock(); |
| 708 | list->notification_trigger_clients_ht = NULL; |
| 709 | } |
| 710 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 711 | &list->list, node) { |
| 712 | free(client_list_element); |
| 713 | } |
| 714 | pthread_mutex_destroy(&list->lock); |
| 715 | call_rcu(&list->rcu_node, free_notification_client_list_rcu); |
| 716 | } |
| 717 | |
| 718 | static |
| 719 | struct notification_client_list *notification_client_list_create( |
| 720 | const struct lttng_trigger *trigger) |
| 721 | { |
| 722 | struct notification_client_list *client_list = |
| 723 | zmalloc(sizeof(*client_list)); |
| 724 | |
| 725 | if (!client_list) { |
| 726 | goto error; |
| 727 | } |
| 728 | pthread_mutex_init(&client_list->lock, NULL); |
| 729 | urcu_ref_init(&client_list->ref); |
| 730 | cds_lfht_node_init(&client_list->notification_trigger_clients_ht_node); |
| 731 | CDS_INIT_LIST_HEAD(&client_list->list); |
| 732 | client_list->trigger = trigger; |
| 733 | error: |
| 734 | return client_list; |
| 735 | } |
| 736 | |
| 737 | static |
| 738 | void publish_notification_client_list( |
| 739 | struct notification_thread_state *state, |
| 740 | struct notification_client_list *list) |
| 741 | { |
| 742 | const struct lttng_condition *condition = |
| 743 | lttng_trigger_get_const_condition(list->trigger); |
| 744 | |
| 745 | assert(!list->notification_trigger_clients_ht); |
| 746 | notification_client_list_get(list); |
| 747 | |
| 748 | list->notification_trigger_clients_ht = |
| 749 | state->notification_trigger_clients_ht; |
| 750 | |
| 751 | rcu_read_lock(); |
| 752 | cds_lfht_add(state->notification_trigger_clients_ht, |
| 753 | lttng_condition_hash(condition), |
| 754 | &list->notification_trigger_clients_ht_node); |
| 755 | rcu_read_unlock(); |
| 756 | } |
| 757 | |
| 758 | LTTNG_HIDDEN |
| 759 | void notification_client_list_put(struct notification_client_list *list) |
| 760 | { |
| 761 | if (!list) { |
| 762 | return; |
| 763 | } |
| 764 | return urcu_ref_put(&list->ref, notification_client_list_release); |
| 765 | } |
| 766 | |
| 767 | /* Provides a reference to the returned list. */ |
| 768 | static |
| 769 | struct notification_client_list *get_client_list_from_condition( |
| 770 | struct notification_thread_state *state, |
| 771 | const struct lttng_condition *condition) |
| 772 | { |
| 773 | struct cds_lfht_node *node; |
| 774 | struct cds_lfht_iter iter; |
| 775 | struct notification_client_list *list = NULL; |
| 776 | |
| 777 | rcu_read_lock(); |
| 778 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 779 | lttng_condition_hash(condition), |
| 780 | match_client_list_condition, |
| 781 | condition, |
| 782 | &iter); |
| 783 | node = cds_lfht_iter_get_node(&iter); |
| 784 | if (node) { |
| 785 | list = container_of(node, struct notification_client_list, |
| 786 | notification_trigger_clients_ht_node); |
| 787 | list = notification_client_list_get(list) ? list : NULL; |
| 788 | } |
| 789 | |
| 790 | rcu_read_unlock(); |
| 791 | return list; |
| 792 | } |
| 793 | |
| 794 | static |
| 795 | int evaluate_channel_condition_for_client( |
| 796 | const struct lttng_condition *condition, |
| 797 | struct notification_thread_state *state, |
| 798 | struct lttng_evaluation **evaluation, |
| 799 | uid_t *session_uid, gid_t *session_gid) |
| 800 | { |
| 801 | int ret; |
| 802 | struct cds_lfht_iter iter; |
| 803 | struct cds_lfht_node *node; |
| 804 | struct channel_info *channel_info = NULL; |
| 805 | struct channel_key *channel_key = NULL; |
| 806 | struct channel_state_sample *last_sample = NULL; |
| 807 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
| 808 | |
| 809 | rcu_read_lock(); |
| 810 | |
| 811 | /* Find the channel associated with the condition. */ |
| 812 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, |
| 813 | channel_trigger_list, channel_triggers_ht_node) { |
| 814 | struct lttng_trigger_list_element *element; |
| 815 | |
| 816 | cds_list_for_each_entry(element, &channel_trigger_list->list, node) { |
| 817 | const struct lttng_condition *current_condition = |
| 818 | lttng_trigger_get_const_condition( |
| 819 | element->trigger); |
| 820 | |
| 821 | assert(current_condition); |
| 822 | if (!lttng_condition_is_equal(condition, |
| 823 | current_condition)) { |
| 824 | continue; |
| 825 | } |
| 826 | |
| 827 | /* Found the trigger, save the channel key. */ |
| 828 | channel_key = &channel_trigger_list->channel_key; |
| 829 | break; |
| 830 | } |
| 831 | if (channel_key) { |
| 832 | /* The channel key was found stop iteration. */ |
| 833 | break; |
| 834 | } |
| 835 | } |
| 836 | |
| 837 | if (!channel_key){ |
| 838 | /* No channel found; normal exit. */ |
| 839 | DBG("[notification-thread] No known channel associated with newly subscribed-to condition"); |
| 840 | ret = 0; |
| 841 | goto end; |
| 842 | } |
| 843 | |
| 844 | /* Fetch channel info for the matching channel. */ |
| 845 | cds_lfht_lookup(state->channels_ht, |
| 846 | hash_channel_key(channel_key), |
| 847 | match_channel_info, |
| 848 | channel_key, |
| 849 | &iter); |
| 850 | node = cds_lfht_iter_get_node(&iter); |
| 851 | assert(node); |
| 852 | channel_info = caa_container_of(node, struct channel_info, |
| 853 | channels_ht_node); |
| 854 | |
| 855 | /* Retrieve the channel's last sample, if it exists. */ |
| 856 | cds_lfht_lookup(state->channel_state_ht, |
| 857 | hash_channel_key(channel_key), |
| 858 | match_channel_state_sample, |
| 859 | channel_key, |
| 860 | &iter); |
| 861 | node = cds_lfht_iter_get_node(&iter); |
| 862 | if (node) { |
| 863 | last_sample = caa_container_of(node, |
| 864 | struct channel_state_sample, |
| 865 | channel_state_ht_node); |
| 866 | } else { |
| 867 | /* Nothing to evaluate, no sample was ever taken. Normal exit */ |
| 868 | DBG("[notification-thread] No channel sample associated with newly subscribed-to condition"); |
| 869 | ret = 0; |
| 870 | goto end; |
| 871 | } |
| 872 | |
| 873 | ret = evaluate_buffer_condition(condition, evaluation, state, |
| 874 | NULL, last_sample, |
| 875 | 0, channel_info->session_info->consumed_data_size, |
| 876 | channel_info); |
| 877 | if (ret) { |
| 878 | WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition"); |
| 879 | goto end; |
| 880 | } |
| 881 | |
| 882 | *session_uid = channel_info->session_info->uid; |
| 883 | *session_gid = channel_info->session_info->gid; |
| 884 | end: |
| 885 | rcu_read_unlock(); |
| 886 | return ret; |
| 887 | } |
| 888 | |
| 889 | static |
| 890 | const char *get_condition_session_name(const struct lttng_condition *condition) |
| 891 | { |
| 892 | const char *session_name = NULL; |
| 893 | enum lttng_condition_status status; |
| 894 | |
| 895 | switch (lttng_condition_get_type(condition)) { |
| 896 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 897 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 898 | status = lttng_condition_buffer_usage_get_session_name( |
| 899 | condition, &session_name); |
| 900 | break; |
| 901 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 902 | status = lttng_condition_session_consumed_size_get_session_name( |
| 903 | condition, &session_name); |
| 904 | break; |
| 905 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 906 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 907 | status = lttng_condition_session_rotation_get_session_name( |
| 908 | condition, &session_name); |
| 909 | break; |
| 910 | default: |
| 911 | abort(); |
| 912 | } |
| 913 | if (status != LTTNG_CONDITION_STATUS_OK) { |
| 914 | ERR("[notification-thread] Failed to retrieve session rotation condition's session name"); |
| 915 | goto end; |
| 916 | } |
| 917 | end: |
| 918 | return session_name; |
| 919 | } |
| 920 | |
| 921 | static |
| 922 | int evaluate_session_condition_for_client( |
| 923 | const struct lttng_condition *condition, |
| 924 | struct notification_thread_state *state, |
| 925 | struct lttng_evaluation **evaluation, |
| 926 | uid_t *session_uid, gid_t *session_gid) |
| 927 | { |
| 928 | int ret; |
| 929 | struct cds_lfht_iter iter; |
| 930 | struct cds_lfht_node *node; |
| 931 | const char *session_name; |
| 932 | struct session_info *session_info = NULL; |
| 933 | |
| 934 | rcu_read_lock(); |
| 935 | session_name = get_condition_session_name(condition); |
| 936 | |
| 937 | /* Find the session associated with the trigger. */ |
| 938 | cds_lfht_lookup(state->sessions_ht, |
| 939 | hash_key_str(session_name, lttng_ht_seed), |
| 940 | match_session, |
| 941 | session_name, |
| 942 | &iter); |
| 943 | node = cds_lfht_iter_get_node(&iter); |
| 944 | if (!node) { |
| 945 | DBG("[notification-thread] No known session matching name \"%s\"", |
| 946 | session_name); |
| 947 | ret = 0; |
| 948 | goto end; |
| 949 | } |
| 950 | |
| 951 | session_info = caa_container_of(node, struct session_info, |
| 952 | sessions_ht_node); |
| 953 | session_info_get(session_info); |
| 954 | |
| 955 | /* |
| 956 | * Evaluation is performed in-line here since only one type of |
| 957 | * session-bound condition is handled for the moment. |
| 958 | */ |
| 959 | switch (lttng_condition_get_type(condition)) { |
| 960 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 961 | if (!session_info->rotation.ongoing) { |
| 962 | ret = 0; |
| 963 | goto end_session_put; |
| 964 | } |
| 965 | |
| 966 | *evaluation = lttng_evaluation_session_rotation_ongoing_create( |
| 967 | session_info->rotation.id); |
| 968 | if (!*evaluation) { |
| 969 | /* Fatal error. */ |
| 970 | ERR("[notification-thread] Failed to create session rotation ongoing evaluation for session \"%s\"", |
| 971 | session_info->name); |
| 972 | ret = -1; |
| 973 | goto end_session_put; |
| 974 | } |
| 975 | ret = 0; |
| 976 | break; |
| 977 | default: |
| 978 | ret = 0; |
| 979 | goto end_session_put; |
| 980 | } |
| 981 | |
| 982 | *session_uid = session_info->uid; |
| 983 | *session_gid = session_info->gid; |
| 984 | |
| 985 | end_session_put: |
| 986 | session_info_put(session_info); |
| 987 | end: |
| 988 | rcu_read_unlock(); |
| 989 | return ret; |
| 990 | } |
| 991 | |
| 992 | static |
| 993 | int evaluate_condition_for_client(const struct lttng_trigger *trigger, |
| 994 | const struct lttng_condition *condition, |
| 995 | struct notification_client *client, |
| 996 | struct notification_thread_state *state) |
| 997 | { |
| 998 | int ret; |
| 999 | struct lttng_evaluation *evaluation = NULL; |
| 1000 | struct notification_client_list client_list = { |
| 1001 | .lock = PTHREAD_MUTEX_INITIALIZER, |
| 1002 | }; |
| 1003 | struct notification_client_list_element client_list_element = { 0 }; |
| 1004 | uid_t object_uid = 0; |
| 1005 | gid_t object_gid = 0; |
| 1006 | |
| 1007 | assert(trigger); |
| 1008 | assert(condition); |
| 1009 | assert(client); |
| 1010 | assert(state); |
| 1011 | |
| 1012 | switch (get_condition_binding_object(condition)) { |
| 1013 | case LTTNG_OBJECT_TYPE_SESSION: |
| 1014 | ret = evaluate_session_condition_for_client(condition, state, |
| 1015 | &evaluation, &object_uid, &object_gid); |
| 1016 | break; |
| 1017 | case LTTNG_OBJECT_TYPE_CHANNEL: |
| 1018 | ret = evaluate_channel_condition_for_client(condition, state, |
| 1019 | &evaluation, &object_uid, &object_gid); |
| 1020 | break; |
| 1021 | case LTTNG_OBJECT_TYPE_NONE: |
| 1022 | ret = 0; |
| 1023 | goto end; |
| 1024 | case LTTNG_OBJECT_TYPE_UNKNOWN: |
| 1025 | default: |
| 1026 | ret = -1; |
| 1027 | goto end; |
| 1028 | } |
| 1029 | if (ret) { |
| 1030 | /* Fatal error. */ |
| 1031 | goto end; |
| 1032 | } |
| 1033 | if (!evaluation) { |
| 1034 | /* Evaluation yielded nothing. Normal exit. */ |
| 1035 | DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client"); |
| 1036 | ret = 0; |
| 1037 | goto end; |
| 1038 | } |
| 1039 | |
| 1040 | /* |
| 1041 | * Create a temporary client list with the client currently |
| 1042 | * subscribing. |
| 1043 | */ |
| 1044 | cds_lfht_node_init(&client_list.notification_trigger_clients_ht_node); |
| 1045 | CDS_INIT_LIST_HEAD(&client_list.list); |
| 1046 | client_list.trigger = trigger; |
| 1047 | |
| 1048 | CDS_INIT_LIST_HEAD(&client_list_element.node); |
| 1049 | client_list_element.client = client; |
| 1050 | cds_list_add(&client_list_element.node, &client_list.list); |
| 1051 | |
| 1052 | /* Send evaluation result to the newly-subscribed client. */ |
| 1053 | DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client"); |
| 1054 | ret = send_evaluation_to_clients(trigger, evaluation, &client_list, |
| 1055 | state, object_uid, object_gid); |
| 1056 | |
| 1057 | end: |
| 1058 | return ret; |
| 1059 | } |
| 1060 | |
| 1061 | static |
| 1062 | int notification_thread_client_subscribe(struct notification_client *client, |
| 1063 | struct lttng_condition *condition, |
| 1064 | struct notification_thread_state *state, |
| 1065 | enum lttng_notification_channel_status *_status) |
| 1066 | { |
| 1067 | int ret = 0; |
| 1068 | struct notification_client_list *client_list = NULL; |
| 1069 | struct lttng_condition_list_element *condition_list_element = NULL; |
| 1070 | struct notification_client_list_element *client_list_element = NULL; |
| 1071 | enum lttng_notification_channel_status status = |
| 1072 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 1073 | |
| 1074 | /* |
| 1075 | * Ensure that the client has not already subscribed to this condition |
| 1076 | * before. |
| 1077 | */ |
| 1078 | cds_list_for_each_entry(condition_list_element, &client->condition_list, node) { |
| 1079 | if (lttng_condition_is_equal(condition_list_element->condition, |
| 1080 | condition)) { |
| 1081 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED; |
| 1082 | goto end; |
| 1083 | } |
| 1084 | } |
| 1085 | |
| 1086 | condition_list_element = zmalloc(sizeof(*condition_list_element)); |
| 1087 | if (!condition_list_element) { |
| 1088 | ret = -1; |
| 1089 | goto error; |
| 1090 | } |
| 1091 | client_list_element = zmalloc(sizeof(*client_list_element)); |
| 1092 | if (!client_list_element) { |
| 1093 | ret = -1; |
| 1094 | goto error; |
| 1095 | } |
| 1096 | |
| 1097 | /* |
| 1098 | * Add the newly-subscribed condition to the client's subscription list. |
| 1099 | */ |
| 1100 | CDS_INIT_LIST_HEAD(&condition_list_element->node); |
| 1101 | condition_list_element->condition = condition; |
| 1102 | cds_list_add(&condition_list_element->node, &client->condition_list); |
| 1103 | |
| 1104 | client_list = get_client_list_from_condition(state, condition); |
| 1105 | if (!client_list) { |
| 1106 | /* |
| 1107 | * No notification-emiting trigger registered with this |
| 1108 | * condition. We don't evaluate the condition right away |
| 1109 | * since this trigger is not registered yet. |
| 1110 | */ |
| 1111 | free(client_list_element); |
| 1112 | goto end; |
| 1113 | } |
| 1114 | |
| 1115 | /* |
| 1116 | * The condition to which the client just subscribed is evaluated |
| 1117 | * at this point so that conditions that are already TRUE result |
| 1118 | * in a notification being sent out. |
| 1119 | * |
| 1120 | * The client_list's trigger is used without locking the list itself. |
| 1121 | * This is correct since the list doesn't own the trigger and the |
| 1122 | * object is immutable. |
| 1123 | */ |
| 1124 | if (evaluate_condition_for_client(client_list->trigger, condition, |
| 1125 | client, state)) { |
| 1126 | WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); |
| 1127 | ret = -1; |
| 1128 | free(client_list_element); |
| 1129 | goto end; |
| 1130 | } |
| 1131 | |
| 1132 | /* |
| 1133 | * Add the client to the list of clients interested in a given trigger |
| 1134 | * if a "notification" trigger with a corresponding condition was |
| 1135 | * added prior. |
| 1136 | */ |
| 1137 | client_list_element->client = client; |
| 1138 | CDS_INIT_LIST_HEAD(&client_list_element->node); |
| 1139 | |
| 1140 | pthread_mutex_lock(&client_list->lock); |
| 1141 | cds_list_add(&client_list_element->node, &client_list->list); |
| 1142 | pthread_mutex_unlock(&client_list->lock); |
| 1143 | end: |
| 1144 | if (_status) { |
| 1145 | *_status = status; |
| 1146 | } |
| 1147 | if (client_list) { |
| 1148 | notification_client_list_put(client_list); |
| 1149 | } |
| 1150 | return ret; |
| 1151 | error: |
| 1152 | free(condition_list_element); |
| 1153 | free(client_list_element); |
| 1154 | return ret; |
| 1155 | } |
| 1156 | |
| 1157 | static |
| 1158 | int notification_thread_client_unsubscribe( |
| 1159 | struct notification_client *client, |
| 1160 | struct lttng_condition *condition, |
| 1161 | struct notification_thread_state *state, |
| 1162 | enum lttng_notification_channel_status *_status) |
| 1163 | { |
| 1164 | struct notification_client_list *client_list; |
| 1165 | struct lttng_condition_list_element *condition_list_element, |
| 1166 | *condition_tmp; |
| 1167 | struct notification_client_list_element *client_list_element, |
| 1168 | *client_tmp; |
| 1169 | bool condition_found = false; |
| 1170 | enum lttng_notification_channel_status status = |
| 1171 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 1172 | |
| 1173 | /* Remove the condition from the client's condition list. */ |
| 1174 | cds_list_for_each_entry_safe(condition_list_element, condition_tmp, |
| 1175 | &client->condition_list, node) { |
| 1176 | if (!lttng_condition_is_equal(condition_list_element->condition, |
| 1177 | condition)) { |
| 1178 | continue; |
| 1179 | } |
| 1180 | |
| 1181 | cds_list_del(&condition_list_element->node); |
| 1182 | /* |
| 1183 | * The caller may be iterating on the client's conditions to |
| 1184 | * tear down a client's connection. In this case, the condition |
| 1185 | * will be destroyed at the end. |
| 1186 | */ |
| 1187 | if (condition != condition_list_element->condition) { |
| 1188 | lttng_condition_destroy( |
| 1189 | condition_list_element->condition); |
| 1190 | } |
| 1191 | free(condition_list_element); |
| 1192 | condition_found = true; |
| 1193 | break; |
| 1194 | } |
| 1195 | |
| 1196 | if (!condition_found) { |
| 1197 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION; |
| 1198 | goto end; |
| 1199 | } |
| 1200 | |
| 1201 | /* |
| 1202 | * Remove the client from the list of clients interested the trigger |
| 1203 | * matching the condition. |
| 1204 | */ |
| 1205 | client_list = get_client_list_from_condition(state, condition); |
| 1206 | if (!client_list) { |
| 1207 | goto end; |
| 1208 | } |
| 1209 | |
| 1210 | pthread_mutex_lock(&client_list->lock); |
| 1211 | cds_list_for_each_entry_safe(client_list_element, client_tmp, |
| 1212 | &client_list->list, node) { |
| 1213 | if (client_list_element->client->id != client->id) { |
| 1214 | continue; |
| 1215 | } |
| 1216 | cds_list_del(&client_list_element->node); |
| 1217 | free(client_list_element); |
| 1218 | break; |
| 1219 | } |
| 1220 | pthread_mutex_unlock(&client_list->lock); |
| 1221 | notification_client_list_put(client_list); |
| 1222 | client_list = NULL; |
| 1223 | end: |
| 1224 | lttng_condition_destroy(condition); |
| 1225 | if (_status) { |
| 1226 | *_status = status; |
| 1227 | } |
| 1228 | return 0; |
| 1229 | } |
| 1230 | |
| 1231 | static |
| 1232 | void free_notification_client_rcu(struct rcu_head *node) |
| 1233 | { |
| 1234 | free(caa_container_of(node, struct notification_client, rcu_node)); |
| 1235 | } |
| 1236 | |
| 1237 | static |
| 1238 | void notification_client_destroy(struct notification_client *client, |
| 1239 | struct notification_thread_state *state) |
| 1240 | { |
| 1241 | if (!client) { |
| 1242 | return; |
| 1243 | } |
| 1244 | |
| 1245 | /* |
| 1246 | * The client object is not reachable by other threads, no need to lock |
| 1247 | * the client here. |
| 1248 | */ |
| 1249 | if (client->socket >= 0) { |
| 1250 | (void) lttcomm_close_unix_sock(client->socket); |
| 1251 | client->socket = -1; |
| 1252 | } |
| 1253 | client->communication.active = false; |
| 1254 | lttng_payload_reset(&client->communication.inbound.payload); |
| 1255 | lttng_payload_reset(&client->communication.outbound.payload); |
| 1256 | pthread_mutex_destroy(&client->lock); |
| 1257 | call_rcu(&client->rcu_node, free_notification_client_rcu); |
| 1258 | } |
| 1259 | |
| 1260 | /* |
| 1261 | * Call with rcu_read_lock held (and hold for the lifetime of the returned |
| 1262 | * client pointer). |
| 1263 | */ |
| 1264 | static |
| 1265 | struct notification_client *get_client_from_socket(int socket, |
| 1266 | struct notification_thread_state *state) |
| 1267 | { |
| 1268 | struct cds_lfht_iter iter; |
| 1269 | struct cds_lfht_node *node; |
| 1270 | struct notification_client *client = NULL; |
| 1271 | |
| 1272 | cds_lfht_lookup(state->client_socket_ht, |
| 1273 | hash_client_socket(socket), |
| 1274 | match_client_socket, |
| 1275 | (void *) (unsigned long) socket, |
| 1276 | &iter); |
| 1277 | node = cds_lfht_iter_get_node(&iter); |
| 1278 | if (!node) { |
| 1279 | goto end; |
| 1280 | } |
| 1281 | |
| 1282 | client = caa_container_of(node, struct notification_client, |
| 1283 | client_socket_ht_node); |
| 1284 | end: |
| 1285 | return client; |
| 1286 | } |
| 1287 | |
| 1288 | /* |
| 1289 | * Call with rcu_read_lock held (and hold for the lifetime of the returned |
| 1290 | * client pointer). |
| 1291 | */ |
| 1292 | static |
| 1293 | struct notification_client *get_client_from_id(notification_client_id id, |
| 1294 | struct notification_thread_state *state) |
| 1295 | { |
| 1296 | struct cds_lfht_iter iter; |
| 1297 | struct cds_lfht_node *node; |
| 1298 | struct notification_client *client = NULL; |
| 1299 | |
| 1300 | cds_lfht_lookup(state->client_id_ht, |
| 1301 | hash_client_id(id), |
| 1302 | match_client_id, |
| 1303 | &id, |
| 1304 | &iter); |
| 1305 | node = cds_lfht_iter_get_node(&iter); |
| 1306 | if (!node) { |
| 1307 | goto end; |
| 1308 | } |
| 1309 | |
| 1310 | client = caa_container_of(node, struct notification_client, |
| 1311 | client_id_ht_node); |
| 1312 | end: |
| 1313 | return client; |
| 1314 | } |
| 1315 | |
| 1316 | static |
| 1317 | bool buffer_usage_condition_applies_to_channel( |
| 1318 | const struct lttng_condition *condition, |
| 1319 | const struct channel_info *channel_info) |
| 1320 | { |
| 1321 | enum lttng_condition_status status; |
| 1322 | enum lttng_domain_type condition_domain; |
| 1323 | const char *condition_session_name = NULL; |
| 1324 | const char *condition_channel_name = NULL; |
| 1325 | |
| 1326 | status = lttng_condition_buffer_usage_get_domain_type(condition, |
| 1327 | &condition_domain); |
| 1328 | assert(status == LTTNG_CONDITION_STATUS_OK); |
| 1329 | if (channel_info->key.domain != condition_domain) { |
| 1330 | goto fail; |
| 1331 | } |
| 1332 | |
| 1333 | status = lttng_condition_buffer_usage_get_session_name( |
| 1334 | condition, &condition_session_name); |
| 1335 | assert((status == LTTNG_CONDITION_STATUS_OK) && condition_session_name); |
| 1336 | |
| 1337 | status = lttng_condition_buffer_usage_get_channel_name( |
| 1338 | condition, &condition_channel_name); |
| 1339 | assert((status == LTTNG_CONDITION_STATUS_OK) && condition_channel_name); |
| 1340 | |
| 1341 | if (strcmp(channel_info->session_info->name, condition_session_name)) { |
| 1342 | goto fail; |
| 1343 | } |
| 1344 | if (strcmp(channel_info->name, condition_channel_name)) { |
| 1345 | goto fail; |
| 1346 | } |
| 1347 | |
| 1348 | return true; |
| 1349 | fail: |
| 1350 | return false; |
| 1351 | } |
| 1352 | |
| 1353 | static |
| 1354 | bool session_consumed_size_condition_applies_to_channel( |
| 1355 | const struct lttng_condition *condition, |
| 1356 | const struct channel_info *channel_info) |
| 1357 | { |
| 1358 | enum lttng_condition_status status; |
| 1359 | const char *condition_session_name = NULL; |
| 1360 | |
| 1361 | status = lttng_condition_session_consumed_size_get_session_name( |
| 1362 | condition, &condition_session_name); |
| 1363 | assert((status == LTTNG_CONDITION_STATUS_OK) && condition_session_name); |
| 1364 | |
| 1365 | if (strcmp(channel_info->session_info->name, condition_session_name)) { |
| 1366 | goto fail; |
| 1367 | } |
| 1368 | |
| 1369 | return true; |
| 1370 | fail: |
| 1371 | return false; |
| 1372 | } |
| 1373 | |
| 1374 | static |
| 1375 | bool trigger_applies_to_channel(const struct lttng_trigger *trigger, |
| 1376 | const struct channel_info *channel_info) |
| 1377 | { |
| 1378 | const struct lttng_condition *condition; |
| 1379 | bool trigger_applies; |
| 1380 | |
| 1381 | condition = lttng_trigger_get_const_condition(trigger); |
| 1382 | if (!condition) { |
| 1383 | goto fail; |
| 1384 | } |
| 1385 | |
| 1386 | switch (lttng_condition_get_type(condition)) { |
| 1387 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 1388 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 1389 | trigger_applies = buffer_usage_condition_applies_to_channel( |
| 1390 | condition, channel_info); |
| 1391 | break; |
| 1392 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 1393 | trigger_applies = session_consumed_size_condition_applies_to_channel( |
| 1394 | condition, channel_info); |
| 1395 | break; |
| 1396 | default: |
| 1397 | goto fail; |
| 1398 | } |
| 1399 | |
| 1400 | return trigger_applies; |
| 1401 | fail: |
| 1402 | return false; |
| 1403 | } |
| 1404 | |
| 1405 | static |
| 1406 | bool trigger_applies_to_client(struct lttng_trigger *trigger, |
| 1407 | struct notification_client *client) |
| 1408 | { |
| 1409 | bool applies = false; |
| 1410 | struct lttng_condition_list_element *condition_list_element; |
| 1411 | |
| 1412 | cds_list_for_each_entry(condition_list_element, &client->condition_list, |
| 1413 | node) { |
| 1414 | applies = lttng_condition_is_equal( |
| 1415 | condition_list_element->condition, |
| 1416 | lttng_trigger_get_condition(trigger)); |
| 1417 | if (applies) { |
| 1418 | break; |
| 1419 | } |
| 1420 | } |
| 1421 | return applies; |
| 1422 | } |
| 1423 | |
| 1424 | /* Must be called with RCU read lock held. */ |
| 1425 | static |
| 1426 | struct lttng_session_trigger_list *get_session_trigger_list( |
| 1427 | struct notification_thread_state *state, |
| 1428 | const char *session_name) |
| 1429 | { |
| 1430 | struct lttng_session_trigger_list *list = NULL; |
| 1431 | struct cds_lfht_node *node; |
| 1432 | struct cds_lfht_iter iter; |
| 1433 | |
| 1434 | cds_lfht_lookup(state->session_triggers_ht, |
| 1435 | hash_key_str(session_name, lttng_ht_seed), |
| 1436 | match_session_trigger_list, |
| 1437 | session_name, |
| 1438 | &iter); |
| 1439 | node = cds_lfht_iter_get_node(&iter); |
| 1440 | if (!node) { |
| 1441 | /* |
| 1442 | * Not an error, the list of triggers applying to that session |
| 1443 | * will be initialized when the session is created. |
| 1444 | */ |
| 1445 | DBG("[notification-thread] No trigger list found for session \"%s\" as it is not yet known to the notification system", |
| 1446 | session_name); |
| 1447 | goto end; |
| 1448 | } |
| 1449 | |
| 1450 | list = caa_container_of(node, |
| 1451 | struct lttng_session_trigger_list, |
| 1452 | session_triggers_ht_node); |
| 1453 | end: |
| 1454 | return list; |
| 1455 | } |
| 1456 | |
| 1457 | /* |
| 1458 | * Allocate an empty lttng_session_trigger_list for the session named |
| 1459 | * 'session_name'. |
| 1460 | * |
| 1461 | * No ownership of 'session_name' is assumed by the session trigger list. |
| 1462 | * It is the caller's responsability to ensure the session name is alive |
| 1463 | * for as long as this list is. |
| 1464 | */ |
| 1465 | static |
| 1466 | struct lttng_session_trigger_list *lttng_session_trigger_list_create( |
| 1467 | const char *session_name, |
| 1468 | struct cds_lfht *session_triggers_ht) |
| 1469 | { |
| 1470 | struct lttng_session_trigger_list *list; |
| 1471 | |
| 1472 | list = zmalloc(sizeof(*list)); |
| 1473 | if (!list) { |
| 1474 | goto end; |
| 1475 | } |
| 1476 | list->session_name = session_name; |
| 1477 | CDS_INIT_LIST_HEAD(&list->list); |
| 1478 | cds_lfht_node_init(&list->session_triggers_ht_node); |
| 1479 | list->session_triggers_ht = session_triggers_ht; |
| 1480 | |
| 1481 | rcu_read_lock(); |
| 1482 | /* Publish the list through the session_triggers_ht. */ |
| 1483 | cds_lfht_add(session_triggers_ht, |
| 1484 | hash_key_str(session_name, lttng_ht_seed), |
| 1485 | &list->session_triggers_ht_node); |
| 1486 | rcu_read_unlock(); |
| 1487 | end: |
| 1488 | return list; |
| 1489 | } |
| 1490 | |
| 1491 | static |
| 1492 | void free_session_trigger_list_rcu(struct rcu_head *node) |
| 1493 | { |
| 1494 | free(caa_container_of(node, struct lttng_session_trigger_list, |
| 1495 | rcu_node)); |
| 1496 | } |
| 1497 | |
| 1498 | static |
| 1499 | void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list *list) |
| 1500 | { |
| 1501 | struct lttng_trigger_list_element *trigger_list_element, *tmp; |
| 1502 | |
| 1503 | /* Empty the list element by element, and then free the list itself. */ |
| 1504 | cds_list_for_each_entry_safe(trigger_list_element, tmp, |
| 1505 | &list->list, node) { |
| 1506 | cds_list_del(&trigger_list_element->node); |
| 1507 | free(trigger_list_element); |
| 1508 | } |
| 1509 | rcu_read_lock(); |
| 1510 | /* Unpublish the list from the session_triggers_ht. */ |
| 1511 | cds_lfht_del(list->session_triggers_ht, |
| 1512 | &list->session_triggers_ht_node); |
| 1513 | rcu_read_unlock(); |
| 1514 | call_rcu(&list->rcu_node, free_session_trigger_list_rcu); |
| 1515 | } |
| 1516 | |
| 1517 | static |
| 1518 | int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list, |
| 1519 | struct lttng_trigger *trigger) |
| 1520 | { |
| 1521 | int ret = 0; |
| 1522 | struct lttng_trigger_list_element *new_element = |
| 1523 | zmalloc(sizeof(*new_element)); |
| 1524 | |
| 1525 | if (!new_element) { |
| 1526 | ret = -1; |
| 1527 | goto end; |
| 1528 | } |
| 1529 | CDS_INIT_LIST_HEAD(&new_element->node); |
| 1530 | new_element->trigger = trigger; |
| 1531 | cds_list_add(&new_element->node, &list->list); |
| 1532 | end: |
| 1533 | return ret; |
| 1534 | } |
| 1535 | |
| 1536 | static |
| 1537 | bool trigger_applies_to_session(const struct lttng_trigger *trigger, |
| 1538 | const char *session_name) |
| 1539 | { |
| 1540 | bool applies = false; |
| 1541 | const struct lttng_condition *condition; |
| 1542 | |
| 1543 | condition = lttng_trigger_get_const_condition(trigger); |
| 1544 | switch (lttng_condition_get_type(condition)) { |
| 1545 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 1546 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 1547 | { |
| 1548 | enum lttng_condition_status condition_status; |
| 1549 | const char *condition_session_name; |
| 1550 | |
| 1551 | condition_status = lttng_condition_session_rotation_get_session_name( |
| 1552 | condition, &condition_session_name); |
| 1553 | if (condition_status != LTTNG_CONDITION_STATUS_OK) { |
| 1554 | ERR("[notification-thread] Failed to retrieve session rotation condition's session name"); |
| 1555 | goto end; |
| 1556 | } |
| 1557 | |
| 1558 | assert(condition_session_name); |
| 1559 | applies = !strcmp(condition_session_name, session_name); |
| 1560 | break; |
| 1561 | } |
| 1562 | default: |
| 1563 | goto end; |
| 1564 | } |
| 1565 | end: |
| 1566 | return applies; |
| 1567 | } |
| 1568 | |
| 1569 | /* |
| 1570 | * Allocate and initialize an lttng_session_trigger_list which contains |
| 1571 | * all triggers that apply to the session named 'session_name'. |
| 1572 | * |
| 1573 | * No ownership of 'session_name' is assumed by the session trigger list. |
| 1574 | * It is the caller's responsability to ensure the session name is alive |
| 1575 | * for as long as this list is. |
| 1576 | */ |
| 1577 | static |
| 1578 | struct lttng_session_trigger_list *lttng_session_trigger_list_build( |
| 1579 | const struct notification_thread_state *state, |
| 1580 | const char *session_name) |
| 1581 | { |
| 1582 | int trigger_count = 0; |
| 1583 | struct lttng_session_trigger_list *session_trigger_list = NULL; |
| 1584 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1585 | struct cds_lfht_iter iter; |
| 1586 | |
| 1587 | session_trigger_list = lttng_session_trigger_list_create(session_name, |
| 1588 | state->session_triggers_ht); |
| 1589 | |
| 1590 | /* Add all triggers applying to the session named 'session_name'. */ |
| 1591 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 1592 | node) { |
| 1593 | int ret; |
| 1594 | |
| 1595 | if (!trigger_applies_to_session(trigger_ht_element->trigger, |
| 1596 | session_name)) { |
| 1597 | continue; |
| 1598 | } |
| 1599 | |
| 1600 | ret = lttng_session_trigger_list_add(session_trigger_list, |
| 1601 | trigger_ht_element->trigger); |
| 1602 | if (ret) { |
| 1603 | goto error; |
| 1604 | } |
| 1605 | |
| 1606 | trigger_count++; |
| 1607 | } |
| 1608 | |
| 1609 | DBG("[notification-thread] Found %i triggers that apply to newly created session", |
| 1610 | trigger_count); |
| 1611 | return session_trigger_list; |
| 1612 | error: |
| 1613 | lttng_session_trigger_list_destroy(session_trigger_list); |
| 1614 | return NULL; |
| 1615 | } |
| 1616 | |
| 1617 | static |
| 1618 | struct session_info *find_or_create_session_info( |
| 1619 | struct notification_thread_state *state, |
| 1620 | const char *name, uid_t uid, gid_t gid) |
| 1621 | { |
| 1622 | struct session_info *session = NULL; |
| 1623 | struct cds_lfht_node *node; |
| 1624 | struct cds_lfht_iter iter; |
| 1625 | struct lttng_session_trigger_list *trigger_list; |
| 1626 | |
| 1627 | rcu_read_lock(); |
| 1628 | cds_lfht_lookup(state->sessions_ht, |
| 1629 | hash_key_str(name, lttng_ht_seed), |
| 1630 | match_session, |
| 1631 | name, |
| 1632 | &iter); |
| 1633 | node = cds_lfht_iter_get_node(&iter); |
| 1634 | if (node) { |
| 1635 | DBG("[notification-thread] Found session info of session \"%s\" (uid = %i, gid = %i)", |
| 1636 | name, uid, gid); |
| 1637 | session = caa_container_of(node, struct session_info, |
| 1638 | sessions_ht_node); |
| 1639 | assert(session->uid == uid); |
| 1640 | assert(session->gid == gid); |
| 1641 | session_info_get(session); |
| 1642 | goto end; |
| 1643 | } |
| 1644 | |
| 1645 | trigger_list = lttng_session_trigger_list_build(state, name); |
| 1646 | if (!trigger_list) { |
| 1647 | goto error; |
| 1648 | } |
| 1649 | |
| 1650 | session = session_info_create(name, uid, gid, trigger_list, |
| 1651 | state->sessions_ht); |
| 1652 | if (!session) { |
| 1653 | ERR("[notification-thread] Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)", |
| 1654 | name, uid, gid); |
| 1655 | lttng_session_trigger_list_destroy(trigger_list); |
| 1656 | goto error; |
| 1657 | } |
| 1658 | trigger_list = NULL; |
| 1659 | |
| 1660 | cds_lfht_add(state->sessions_ht, hash_key_str(name, lttng_ht_seed), |
| 1661 | &session->sessions_ht_node); |
| 1662 | end: |
| 1663 | rcu_read_unlock(); |
| 1664 | return session; |
| 1665 | error: |
| 1666 | rcu_read_unlock(); |
| 1667 | session_info_put(session); |
| 1668 | return NULL; |
| 1669 | } |
| 1670 | |
| 1671 | static |
| 1672 | int handle_notification_thread_command_add_channel( |
| 1673 | struct notification_thread_state *state, |
| 1674 | const char *session_name, uid_t session_uid, gid_t session_gid, |
| 1675 | const char *channel_name, enum lttng_domain_type channel_domain, |
| 1676 | uint64_t channel_key_int, uint64_t channel_capacity, |
| 1677 | enum lttng_error_code *cmd_result) |
| 1678 | { |
| 1679 | struct cds_list_head trigger_list; |
| 1680 | struct channel_info *new_channel_info = NULL; |
| 1681 | struct channel_key channel_key = { |
| 1682 | .key = channel_key_int, |
| 1683 | .domain = channel_domain, |
| 1684 | }; |
| 1685 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
| 1686 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1687 | int trigger_count = 0; |
| 1688 | struct cds_lfht_iter iter; |
| 1689 | struct session_info *session_info = NULL; |
| 1690 | |
| 1691 | DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", |
| 1692 | channel_name, session_name, channel_key_int, |
| 1693 | channel_domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); |
| 1694 | |
| 1695 | CDS_INIT_LIST_HEAD(&trigger_list); |
| 1696 | |
| 1697 | session_info = find_or_create_session_info(state, session_name, |
| 1698 | session_uid, session_gid); |
| 1699 | if (!session_info) { |
| 1700 | /* Allocation error or an internal error occurred. */ |
| 1701 | goto error; |
| 1702 | } |
| 1703 | |
| 1704 | new_channel_info = channel_info_create(channel_name, &channel_key, |
| 1705 | channel_capacity, session_info); |
| 1706 | if (!new_channel_info) { |
| 1707 | goto error; |
| 1708 | } |
| 1709 | |
| 1710 | rcu_read_lock(); |
| 1711 | /* Build a list of all triggers applying to the new channel. */ |
| 1712 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 1713 | node) { |
| 1714 | struct lttng_trigger_list_element *new_element; |
| 1715 | |
| 1716 | if (!trigger_applies_to_channel(trigger_ht_element->trigger, |
| 1717 | new_channel_info)) { |
| 1718 | continue; |
| 1719 | } |
| 1720 | |
| 1721 | new_element = zmalloc(sizeof(*new_element)); |
| 1722 | if (!new_element) { |
| 1723 | rcu_read_unlock(); |
| 1724 | goto error; |
| 1725 | } |
| 1726 | CDS_INIT_LIST_HEAD(&new_element->node); |
| 1727 | new_element->trigger = trigger_ht_element->trigger; |
| 1728 | cds_list_add(&new_element->node, &trigger_list); |
| 1729 | trigger_count++; |
| 1730 | } |
| 1731 | rcu_read_unlock(); |
| 1732 | |
| 1733 | DBG("[notification-thread] Found %i triggers that apply to newly added channel", |
| 1734 | trigger_count); |
| 1735 | channel_trigger_list = zmalloc(sizeof(*channel_trigger_list)); |
| 1736 | if (!channel_trigger_list) { |
| 1737 | goto error; |
| 1738 | } |
| 1739 | channel_trigger_list->channel_key = new_channel_info->key; |
| 1740 | CDS_INIT_LIST_HEAD(&channel_trigger_list->list); |
| 1741 | cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node); |
| 1742 | cds_list_splice(&trigger_list, &channel_trigger_list->list); |
| 1743 | |
| 1744 | rcu_read_lock(); |
| 1745 | /* Add channel to the channel_ht which owns the channel_infos. */ |
| 1746 | cds_lfht_add(state->channels_ht, |
| 1747 | hash_channel_key(&new_channel_info->key), |
| 1748 | &new_channel_info->channels_ht_node); |
| 1749 | /* |
| 1750 | * Add the list of triggers associated with this channel to the |
| 1751 | * channel_triggers_ht. |
| 1752 | */ |
| 1753 | cds_lfht_add(state->channel_triggers_ht, |
| 1754 | hash_channel_key(&new_channel_info->key), |
| 1755 | &channel_trigger_list->channel_triggers_ht_node); |
| 1756 | rcu_read_unlock(); |
| 1757 | session_info_put(session_info); |
| 1758 | *cmd_result = LTTNG_OK; |
| 1759 | return 0; |
| 1760 | error: |
| 1761 | channel_info_destroy(new_channel_info); |
| 1762 | session_info_put(session_info); |
| 1763 | return 1; |
| 1764 | } |
| 1765 | |
| 1766 | static |
| 1767 | void free_channel_trigger_list_rcu(struct rcu_head *node) |
| 1768 | { |
| 1769 | free(caa_container_of(node, struct lttng_channel_trigger_list, |
| 1770 | rcu_node)); |
| 1771 | } |
| 1772 | |
| 1773 | static |
| 1774 | void free_channel_state_sample_rcu(struct rcu_head *node) |
| 1775 | { |
| 1776 | free(caa_container_of(node, struct channel_state_sample, |
| 1777 | rcu_node)); |
| 1778 | } |
| 1779 | |
| 1780 | static |
| 1781 | int handle_notification_thread_command_remove_channel( |
| 1782 | struct notification_thread_state *state, |
| 1783 | uint64_t channel_key, enum lttng_domain_type domain, |
| 1784 | enum lttng_error_code *cmd_result) |
| 1785 | { |
| 1786 | struct cds_lfht_node *node; |
| 1787 | struct cds_lfht_iter iter; |
| 1788 | struct lttng_channel_trigger_list *trigger_list; |
| 1789 | struct lttng_trigger_list_element *trigger_list_element, *tmp; |
| 1790 | struct channel_key key = { .key = channel_key, .domain = domain }; |
| 1791 | struct channel_info *channel_info; |
| 1792 | |
| 1793 | DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", |
| 1794 | channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); |
| 1795 | |
| 1796 | rcu_read_lock(); |
| 1797 | |
| 1798 | cds_lfht_lookup(state->channel_triggers_ht, |
| 1799 | hash_channel_key(&key), |
| 1800 | match_channel_trigger_list, |
| 1801 | &key, |
| 1802 | &iter); |
| 1803 | node = cds_lfht_iter_get_node(&iter); |
| 1804 | /* |
| 1805 | * There is a severe internal error if we are being asked to remove a |
| 1806 | * channel that doesn't exist. |
| 1807 | */ |
| 1808 | if (!node) { |
| 1809 | ERR("[notification-thread] Channel being removed is unknown to the notification thread"); |
| 1810 | goto end; |
| 1811 | } |
| 1812 | |
| 1813 | /* Free the list of triggers associated with this channel. */ |
| 1814 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 1815 | channel_triggers_ht_node); |
| 1816 | cds_list_for_each_entry_safe(trigger_list_element, tmp, |
| 1817 | &trigger_list->list, node) { |
| 1818 | cds_list_del(&trigger_list_element->node); |
| 1819 | free(trigger_list_element); |
| 1820 | } |
| 1821 | cds_lfht_del(state->channel_triggers_ht, node); |
| 1822 | call_rcu(&trigger_list->rcu_node, free_channel_trigger_list_rcu); |
| 1823 | |
| 1824 | /* Free sampled channel state. */ |
| 1825 | cds_lfht_lookup(state->channel_state_ht, |
| 1826 | hash_channel_key(&key), |
| 1827 | match_channel_state_sample, |
| 1828 | &key, |
| 1829 | &iter); |
| 1830 | node = cds_lfht_iter_get_node(&iter); |
| 1831 | /* |
| 1832 | * This is expected to be NULL if the channel is destroyed before we |
| 1833 | * received a sample. |
| 1834 | */ |
| 1835 | if (node) { |
| 1836 | struct channel_state_sample *sample = caa_container_of(node, |
| 1837 | struct channel_state_sample, |
| 1838 | channel_state_ht_node); |
| 1839 | |
| 1840 | cds_lfht_del(state->channel_state_ht, node); |
| 1841 | call_rcu(&sample->rcu_node, free_channel_state_sample_rcu); |
| 1842 | } |
| 1843 | |
| 1844 | /* Remove the channel from the channels_ht and free it. */ |
| 1845 | cds_lfht_lookup(state->channels_ht, |
| 1846 | hash_channel_key(&key), |
| 1847 | match_channel_info, |
| 1848 | &key, |
| 1849 | &iter); |
| 1850 | node = cds_lfht_iter_get_node(&iter); |
| 1851 | assert(node); |
| 1852 | channel_info = caa_container_of(node, struct channel_info, |
| 1853 | channels_ht_node); |
| 1854 | cds_lfht_del(state->channels_ht, node); |
| 1855 | channel_info_destroy(channel_info); |
| 1856 | end: |
| 1857 | rcu_read_unlock(); |
| 1858 | *cmd_result = LTTNG_OK; |
| 1859 | return 0; |
| 1860 | } |
| 1861 | |
| 1862 | static |
| 1863 | int handle_notification_thread_command_session_rotation( |
| 1864 | struct notification_thread_state *state, |
| 1865 | enum notification_thread_command_type cmd_type, |
| 1866 | const char *session_name, uid_t session_uid, gid_t session_gid, |
| 1867 | uint64_t trace_archive_chunk_id, |
| 1868 | struct lttng_trace_archive_location *location, |
| 1869 | enum lttng_error_code *_cmd_result) |
| 1870 | { |
| 1871 | int ret = 0; |
| 1872 | enum lttng_error_code cmd_result = LTTNG_OK; |
| 1873 | struct lttng_session_trigger_list *trigger_list; |
| 1874 | struct lttng_trigger_list_element *trigger_list_element; |
| 1875 | struct session_info *session_info; |
| 1876 | const struct lttng_credentials session_creds = { |
| 1877 | .uid = LTTNG_OPTIONAL_INIT_VALUE(session_uid), |
| 1878 | .gid = LTTNG_OPTIONAL_INIT_VALUE(session_gid), |
| 1879 | }; |
| 1880 | |
| 1881 | rcu_read_lock(); |
| 1882 | |
| 1883 | session_info = find_or_create_session_info(state, session_name, |
| 1884 | session_uid, session_gid); |
| 1885 | if (!session_info) { |
| 1886 | /* Allocation error or an internal error occurred. */ |
| 1887 | ret = -1; |
| 1888 | cmd_result = LTTNG_ERR_NOMEM; |
| 1889 | goto end; |
| 1890 | } |
| 1891 | |
| 1892 | session_info->rotation.ongoing = |
| 1893 | cmd_type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING; |
| 1894 | session_info->rotation.id = trace_archive_chunk_id; |
| 1895 | trigger_list = get_session_trigger_list(state, session_name); |
| 1896 | if (!trigger_list) { |
| 1897 | DBG("[notification-thread] No triggers applying to session \"%s\" found", |
| 1898 | session_name); |
| 1899 | goto end; |
| 1900 | } |
| 1901 | |
| 1902 | cds_list_for_each_entry(trigger_list_element, &trigger_list->list, |
| 1903 | node) { |
| 1904 | const struct lttng_condition *condition; |
| 1905 | struct lttng_trigger *trigger; |
| 1906 | struct notification_client_list *client_list; |
| 1907 | struct lttng_evaluation *evaluation = NULL; |
| 1908 | enum lttng_condition_type condition_type; |
| 1909 | enum action_executor_status executor_status; |
| 1910 | |
| 1911 | trigger = trigger_list_element->trigger; |
| 1912 | condition = lttng_trigger_get_const_condition(trigger); |
| 1913 | assert(condition); |
| 1914 | condition_type = lttng_condition_get_type(condition); |
| 1915 | |
| 1916 | if (condition_type == LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING && |
| 1917 | cmd_type != NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING) { |
| 1918 | continue; |
| 1919 | } else if (condition_type == LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED && |
| 1920 | cmd_type != NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED) { |
| 1921 | continue; |
| 1922 | } |
| 1923 | |
| 1924 | client_list = get_client_list_from_condition(state, condition); |
| 1925 | if (cmd_type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING) { |
| 1926 | evaluation = lttng_evaluation_session_rotation_ongoing_create( |
| 1927 | trace_archive_chunk_id); |
| 1928 | } else { |
| 1929 | evaluation = lttng_evaluation_session_rotation_completed_create( |
| 1930 | trace_archive_chunk_id, location); |
| 1931 | } |
| 1932 | |
| 1933 | if (!evaluation) { |
| 1934 | /* Internal error */ |
| 1935 | ret = -1; |
| 1936 | cmd_result = LTTNG_ERR_UNK; |
| 1937 | goto put_list; |
| 1938 | } |
| 1939 | |
| 1940 | /* |
| 1941 | * Ownership of `evaluation` transferred to the action executor |
| 1942 | * no matter the result. |
| 1943 | */ |
| 1944 | executor_status = action_executor_enqueue(state->executor, |
| 1945 | trigger, evaluation, &session_creds, |
| 1946 | client_list); |
| 1947 | evaluation = NULL; |
| 1948 | switch (executor_status) { |
| 1949 | case ACTION_EXECUTOR_STATUS_OK: |
| 1950 | break; |
| 1951 | case ACTION_EXECUTOR_STATUS_ERROR: |
| 1952 | case ACTION_EXECUTOR_STATUS_INVALID: |
| 1953 | /* |
| 1954 | * TODO Add trigger identification (name/id) when |
| 1955 | * it is added to the API. |
| 1956 | */ |
| 1957 | ERR("Fatal error occurred while enqueuing action associated with session rotation trigger"); |
| 1958 | ret = -1; |
| 1959 | goto put_list; |
| 1960 | case ACTION_EXECUTOR_STATUS_OVERFLOW: |
| 1961 | /* |
| 1962 | * TODO Add trigger identification (name/id) when |
| 1963 | * it is added to the API. |
| 1964 | * |
| 1965 | * Not a fatal error. |
| 1966 | */ |
| 1967 | WARN("No space left when enqueuing action associated with session rotation trigger"); |
| 1968 | ret = 0; |
| 1969 | goto put_list; |
| 1970 | default: |
| 1971 | abort(); |
| 1972 | } |
| 1973 | |
| 1974 | put_list: |
| 1975 | notification_client_list_put(client_list); |
| 1976 | if (caa_unlikely(ret)) { |
| 1977 | break; |
| 1978 | } |
| 1979 | } |
| 1980 | end: |
| 1981 | session_info_put(session_info); |
| 1982 | *_cmd_result = cmd_result; |
| 1983 | rcu_read_unlock(); |
| 1984 | return ret; |
| 1985 | } |
| 1986 | |
| 1987 | static int handle_notification_thread_command_list_triggers( |
| 1988 | struct notification_thread_handle *handle, |
| 1989 | struct notification_thread_state *state, |
| 1990 | uid_t client_uid, |
| 1991 | struct lttng_triggers **triggers, |
| 1992 | enum lttng_error_code *_cmd_result) |
| 1993 | { |
| 1994 | int ret = 0; |
| 1995 | enum lttng_error_code cmd_result = LTTNG_OK; |
| 1996 | struct cds_lfht_iter iter; |
| 1997 | struct lttng_trigger_ht_element *trigger_ht_element; |
| 1998 | struct lttng_triggers *local_triggers = NULL; |
| 1999 | const struct lttng_credentials *creds; |
| 2000 | |
| 2001 | rcu_read_lock(); |
| 2002 | |
| 2003 | local_triggers = lttng_triggers_create(); |
| 2004 | if (!local_triggers) { |
| 2005 | /* Not a fatal error. */ |
| 2006 | cmd_result = LTTNG_ERR_NOMEM; |
| 2007 | goto end; |
| 2008 | } |
| 2009 | |
| 2010 | cds_lfht_for_each_entry(state->triggers_ht, &iter, |
| 2011 | trigger_ht_element, node) { |
| 2012 | /* |
| 2013 | * Only return the triggers to which the client has access. |
| 2014 | * The root user has visibility over all triggers. |
| 2015 | */ |
| 2016 | creds = lttng_trigger_get_credentials(trigger_ht_element->trigger); |
| 2017 | if (client_uid != lttng_credentials_get_uid(creds) && client_uid != 0) { |
| 2018 | continue; |
| 2019 | } |
| 2020 | |
| 2021 | ret = lttng_triggers_add(local_triggers, |
| 2022 | trigger_ht_element->trigger); |
| 2023 | if (ret < 0) { |
| 2024 | /* Not a fatal error. */ |
| 2025 | ret = 0; |
| 2026 | cmd_result = LTTNG_ERR_NOMEM; |
| 2027 | goto end; |
| 2028 | } |
| 2029 | } |
| 2030 | |
| 2031 | /* Transferring ownership to the caller. */ |
| 2032 | *triggers = local_triggers; |
| 2033 | local_triggers = NULL; |
| 2034 | |
| 2035 | end: |
| 2036 | rcu_read_unlock(); |
| 2037 | lttng_triggers_destroy(local_triggers); |
| 2038 | *_cmd_result = cmd_result; |
| 2039 | return ret; |
| 2040 | } |
| 2041 | |
| 2042 | static |
| 2043 | int condition_is_supported(struct lttng_condition *condition) |
| 2044 | { |
| 2045 | int ret; |
| 2046 | |
| 2047 | switch (lttng_condition_get_type(condition)) { |
| 2048 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 2049 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 2050 | { |
| 2051 | enum lttng_domain_type domain; |
| 2052 | |
| 2053 | ret = lttng_condition_buffer_usage_get_domain_type(condition, |
| 2054 | &domain); |
| 2055 | if (ret) { |
| 2056 | ret = -1; |
| 2057 | goto end; |
| 2058 | } |
| 2059 | |
| 2060 | if (domain != LTTNG_DOMAIN_KERNEL) { |
| 2061 | ret = 1; |
| 2062 | goto end; |
| 2063 | } |
| 2064 | |
| 2065 | /* |
| 2066 | * Older kernel tracers don't expose the API to monitor their |
| 2067 | * buffers. Therefore, we reject triggers that require that |
| 2068 | * mechanism to be available to be evaluated. |
| 2069 | */ |
| 2070 | ret = kernel_supports_ring_buffer_snapshot_sample_positions(); |
| 2071 | break; |
| 2072 | } |
| 2073 | default: |
| 2074 | ret = 1; |
| 2075 | } |
| 2076 | end: |
| 2077 | return ret; |
| 2078 | } |
| 2079 | |
| 2080 | /* Must be called with RCU read lock held. */ |
| 2081 | static |
| 2082 | int bind_trigger_to_matching_session(struct lttng_trigger *trigger, |
| 2083 | struct notification_thread_state *state) |
| 2084 | { |
| 2085 | int ret = 0; |
| 2086 | const struct lttng_condition *condition; |
| 2087 | const char *session_name; |
| 2088 | struct lttng_session_trigger_list *trigger_list; |
| 2089 | |
| 2090 | condition = lttng_trigger_get_const_condition(trigger); |
| 2091 | switch (lttng_condition_get_type(condition)) { |
| 2092 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 2093 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 2094 | { |
| 2095 | enum lttng_condition_status status; |
| 2096 | |
| 2097 | status = lttng_condition_session_rotation_get_session_name( |
| 2098 | condition, &session_name); |
| 2099 | if (status != LTTNG_CONDITION_STATUS_OK) { |
| 2100 | ERR("[notification-thread] Failed to bind trigger to session: unable to get 'session_rotation' condition's session name"); |
| 2101 | ret = -1; |
| 2102 | goto end; |
| 2103 | } |
| 2104 | break; |
| 2105 | } |
| 2106 | default: |
| 2107 | ret = -1; |
| 2108 | goto end; |
| 2109 | } |
| 2110 | |
| 2111 | trigger_list = get_session_trigger_list(state, session_name); |
| 2112 | if (!trigger_list) { |
| 2113 | DBG("[notification-thread] Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system", |
| 2114 | session_name); |
| 2115 | goto end; |
| 2116 | |
| 2117 | } |
| 2118 | |
| 2119 | DBG("[notification-thread] Newly registered trigger bound to session \"%s\"", |
| 2120 | session_name); |
| 2121 | ret = lttng_session_trigger_list_add(trigger_list, trigger); |
| 2122 | end: |
| 2123 | return ret; |
| 2124 | } |
| 2125 | |
| 2126 | /* Must be called with RCU read lock held. */ |
| 2127 | static |
| 2128 | int bind_trigger_to_matching_channels(struct lttng_trigger *trigger, |
| 2129 | struct notification_thread_state *state) |
| 2130 | { |
| 2131 | int ret = 0; |
| 2132 | struct cds_lfht_node *node; |
| 2133 | struct cds_lfht_iter iter; |
| 2134 | struct channel_info *channel; |
| 2135 | |
| 2136 | cds_lfht_for_each_entry(state->channels_ht, &iter, channel, |
| 2137 | channels_ht_node) { |
| 2138 | struct lttng_trigger_list_element *trigger_list_element; |
| 2139 | struct lttng_channel_trigger_list *trigger_list; |
| 2140 | struct cds_lfht_iter lookup_iter; |
| 2141 | |
| 2142 | if (!trigger_applies_to_channel(trigger, channel)) { |
| 2143 | continue; |
| 2144 | } |
| 2145 | |
| 2146 | cds_lfht_lookup(state->channel_triggers_ht, |
| 2147 | hash_channel_key(&channel->key), |
| 2148 | match_channel_trigger_list, |
| 2149 | &channel->key, |
| 2150 | &lookup_iter); |
| 2151 | node = cds_lfht_iter_get_node(&lookup_iter); |
| 2152 | assert(node); |
| 2153 | trigger_list = caa_container_of(node, |
| 2154 | struct lttng_channel_trigger_list, |
| 2155 | channel_triggers_ht_node); |
| 2156 | |
| 2157 | trigger_list_element = zmalloc(sizeof(*trigger_list_element)); |
| 2158 | if (!trigger_list_element) { |
| 2159 | ret = -1; |
| 2160 | goto end; |
| 2161 | } |
| 2162 | CDS_INIT_LIST_HEAD(&trigger_list_element->node); |
| 2163 | trigger_list_element->trigger = trigger; |
| 2164 | cds_list_add(&trigger_list_element->node, &trigger_list->list); |
| 2165 | DBG("[notification-thread] Newly registered trigger bound to channel \"%s\"", |
| 2166 | channel->name); |
| 2167 | } |
| 2168 | end: |
| 2169 | return ret; |
| 2170 | } |
| 2171 | |
| 2172 | static |
| 2173 | bool is_trigger_action_notify(const struct lttng_trigger *trigger) |
| 2174 | { |
| 2175 | bool is_notify = false; |
| 2176 | unsigned int i, count; |
| 2177 | enum lttng_action_status action_status; |
| 2178 | const struct lttng_action *action = |
| 2179 | lttng_trigger_get_const_action(trigger); |
| 2180 | enum lttng_action_type action_type; |
| 2181 | |
| 2182 | assert(action); |
| 2183 | action_type = lttng_action_get_type(action); |
| 2184 | if (action_type == LTTNG_ACTION_TYPE_NOTIFY) { |
| 2185 | is_notify = true; |
| 2186 | goto end; |
| 2187 | } else if (action_type != LTTNG_ACTION_TYPE_GROUP) { |
| 2188 | goto end; |
| 2189 | } |
| 2190 | |
| 2191 | action_status = lttng_action_group_get_count(action, &count); |
| 2192 | assert(action_status == LTTNG_ACTION_STATUS_OK); |
| 2193 | |
| 2194 | for (i = 0; i < count; i++) { |
| 2195 | const struct lttng_action *inner_action = |
| 2196 | lttng_action_group_get_at_index( |
| 2197 | action, i); |
| 2198 | |
| 2199 | action_type = lttng_action_get_type(inner_action); |
| 2200 | if (action_type == LTTNG_ACTION_TYPE_NOTIFY) { |
| 2201 | is_notify = true; |
| 2202 | goto end; |
| 2203 | } |
| 2204 | } |
| 2205 | |
| 2206 | end: |
| 2207 | return is_notify; |
| 2208 | } |
| 2209 | |
| 2210 | static bool trigger_name_taken(struct notification_thread_state *state, |
| 2211 | const struct lttng_trigger *trigger) |
| 2212 | { |
| 2213 | struct cds_lfht_iter iter; |
| 2214 | |
| 2215 | /* |
| 2216 | * No duplicata is allowed in the triggers_by_name_uid_ht. |
| 2217 | * The match is done against the trigger name and uid. |
| 2218 | */ |
| 2219 | cds_lfht_lookup(state->triggers_by_name_uid_ht, |
| 2220 | hash_trigger_by_name_uid(trigger), |
| 2221 | match_trigger_by_name_uid, |
| 2222 | trigger, |
| 2223 | &iter); |
| 2224 | return !!cds_lfht_iter_get_node(&iter); |
| 2225 | } |
| 2226 | |
| 2227 | static |
| 2228 | enum lttng_error_code generate_trigger_name( |
| 2229 | struct notification_thread_state *state, |
| 2230 | struct lttng_trigger *trigger, const char **name) |
| 2231 | { |
| 2232 | enum lttng_error_code ret_code = LTTNG_OK; |
| 2233 | bool taken = false; |
| 2234 | enum lttng_trigger_status status; |
| 2235 | |
| 2236 | do { |
| 2237 | const int ret = lttng_trigger_generate_name(trigger, |
| 2238 | state->trigger_id.name_offset++); |
| 2239 | if (ret) { |
| 2240 | /* The only reason this can fail right now. */ |
| 2241 | ret_code = LTTNG_ERR_NOMEM; |
| 2242 | break; |
| 2243 | } |
| 2244 | |
| 2245 | status = lttng_trigger_get_name(trigger, name); |
| 2246 | assert(status == LTTNG_TRIGGER_STATUS_OK); |
| 2247 | |
| 2248 | taken = trigger_name_taken(state, trigger); |
| 2249 | } while (taken || state->trigger_id.name_offset == UINT64_MAX); |
| 2250 | |
| 2251 | return ret_code; |
| 2252 | } |
| 2253 | |
| 2254 | /* |
| 2255 | * FIXME A client's credentials are not checked when registering a trigger. |
| 2256 | * |
| 2257 | * The effects of this are benign since: |
| 2258 | * - The client will succeed in registering the trigger, as it is valid, |
| 2259 | * - The trigger will, internally, be bound to the channel/session, |
| 2260 | * - The notifications will not be sent since the client's credentials |
| 2261 | * are checked against the channel at that moment. |
| 2262 | * |
| 2263 | * If this function returns a non-zero value, it means something is |
| 2264 | * fundamentally broken and the whole subsystem/thread will be torn down. |
| 2265 | * |
| 2266 | * If a non-fatal error occurs, just set the cmd_result to the appropriate |
| 2267 | * error code. |
| 2268 | */ |
| 2269 | static |
| 2270 | int handle_notification_thread_command_register_trigger( |
| 2271 | struct notification_thread_state *state, |
| 2272 | struct lttng_trigger *trigger, |
| 2273 | enum lttng_error_code *cmd_result) |
| 2274 | { |
| 2275 | int ret = 0; |
| 2276 | struct lttng_condition *condition; |
| 2277 | struct notification_client *client; |
| 2278 | struct notification_client_list *client_list = NULL; |
| 2279 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 2280 | struct notification_client_list_element *client_list_element; |
| 2281 | struct cds_lfht_node *node; |
| 2282 | struct cds_lfht_iter iter; |
| 2283 | const char* trigger_name; |
| 2284 | bool free_trigger = true; |
| 2285 | struct lttng_evaluation *evaluation = NULL; |
| 2286 | struct lttng_credentials object_creds; |
| 2287 | uid_t object_uid; |
| 2288 | gid_t object_gid; |
| 2289 | enum action_executor_status executor_status; |
| 2290 | const uint64_t trigger_tracer_token = |
| 2291 | state->trigger_id.next_tracer_token++; |
| 2292 | |
| 2293 | rcu_read_lock(); |
| 2294 | |
| 2295 | /* Set the trigger's tracer token. */ |
| 2296 | lttng_trigger_set_tracer_token(trigger, trigger_tracer_token); |
| 2297 | |
| 2298 | if (lttng_trigger_get_name(trigger, &trigger_name) == |
| 2299 | LTTNG_TRIGGER_STATUS_UNSET) { |
| 2300 | const enum lttng_error_code ret_code = generate_trigger_name( |
| 2301 | state, trigger, &trigger_name); |
| 2302 | |
| 2303 | if (ret_code != LTTNG_OK) { |
| 2304 | /* Fatal error. */ |
| 2305 | ret = -1; |
| 2306 | *cmd_result = ret_code; |
| 2307 | goto error; |
| 2308 | } |
| 2309 | } else if (trigger_name_taken(state, trigger)) { |
| 2310 | /* Not a fatal error. */ |
| 2311 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; |
| 2312 | ret = 0; |
| 2313 | goto error; |
| 2314 | } |
| 2315 | |
| 2316 | condition = lttng_trigger_get_condition(trigger); |
| 2317 | assert(condition); |
| 2318 | |
| 2319 | ret = condition_is_supported(condition); |
| 2320 | if (ret < 0) { |
| 2321 | goto error; |
| 2322 | } else if (ret == 0) { |
| 2323 | *cmd_result = LTTNG_ERR_NOT_SUPPORTED; |
| 2324 | goto error; |
| 2325 | } else { |
| 2326 | /* Feature is supported, continue. */ |
| 2327 | ret = 0; |
| 2328 | } |
| 2329 | |
| 2330 | trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); |
| 2331 | if (!trigger_ht_element) { |
| 2332 | ret = -1; |
| 2333 | goto error; |
| 2334 | } |
| 2335 | |
| 2336 | /* Add trigger to the trigger_ht. */ |
| 2337 | cds_lfht_node_init(&trigger_ht_element->node); |
| 2338 | cds_lfht_node_init(&trigger_ht_element->node_by_name_uid); |
| 2339 | trigger_ht_element->trigger = trigger; |
| 2340 | |
| 2341 | node = cds_lfht_add_unique(state->triggers_ht, |
| 2342 | lttng_condition_hash(condition), |
| 2343 | match_trigger, |
| 2344 | trigger, |
| 2345 | &trigger_ht_element->node); |
| 2346 | if (node != &trigger_ht_element->node) { |
| 2347 | /* Not a fatal error, simply report it to the client. */ |
| 2348 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; |
| 2349 | goto error_free_ht_element; |
| 2350 | } |
| 2351 | |
| 2352 | node = cds_lfht_add_unique(state->triggers_by_name_uid_ht, |
| 2353 | hash_trigger_by_name_uid(trigger), |
| 2354 | match_trigger_by_name_uid, |
| 2355 | trigger, |
| 2356 | &trigger_ht_element->node_by_name_uid); |
| 2357 | if (node != &trigger_ht_element->node_by_name_uid) { |
| 2358 | /* Not a fatal error, simply report it to the client. */ |
| 2359 | cds_lfht_del(state->triggers_ht, &trigger_ht_element->node); |
| 2360 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; |
| 2361 | goto error_free_ht_element; |
| 2362 | } |
| 2363 | |
| 2364 | /* |
| 2365 | * Ownership of the trigger and of its wrapper was transfered to |
| 2366 | * the triggers_ht. |
| 2367 | */ |
| 2368 | trigger_ht_element = NULL; |
| 2369 | free_trigger = false; |
| 2370 | |
| 2371 | /* |
| 2372 | * The rest only applies to triggers that have a "notify" action. |
| 2373 | * It is not skipped as this is the only action type currently |
| 2374 | * supported. |
| 2375 | */ |
| 2376 | if (is_trigger_action_notify(trigger)) { |
| 2377 | client_list = notification_client_list_create(trigger); |
| 2378 | if (!client_list) { |
| 2379 | ret = -1; |
| 2380 | goto error_free_ht_element; |
| 2381 | } |
| 2382 | |
| 2383 | /* Build a list of clients to which this new trigger applies. */ |
| 2384 | cds_lfht_for_each_entry (state->client_socket_ht, &iter, client, |
| 2385 | client_socket_ht_node) { |
| 2386 | if (!trigger_applies_to_client(trigger, client)) { |
| 2387 | continue; |
| 2388 | } |
| 2389 | |
| 2390 | client_list_element = |
| 2391 | zmalloc(sizeof(*client_list_element)); |
| 2392 | if (!client_list_element) { |
| 2393 | ret = -1; |
| 2394 | goto error_put_client_list; |
| 2395 | } |
| 2396 | |
| 2397 | CDS_INIT_LIST_HEAD(&client_list_element->node); |
| 2398 | client_list_element->client = client; |
| 2399 | cds_list_add(&client_list_element->node, |
| 2400 | &client_list->list); |
| 2401 | } |
| 2402 | |
| 2403 | /* |
| 2404 | * Client list ownership transferred to the |
| 2405 | * notification_trigger_clients_ht. |
| 2406 | */ |
| 2407 | publish_notification_client_list(state, client_list); |
| 2408 | } |
| 2409 | |
| 2410 | switch (get_condition_binding_object(condition)) { |
| 2411 | case LTTNG_OBJECT_TYPE_SESSION: |
| 2412 | /* Add the trigger to the list if it matches a known session. */ |
| 2413 | ret = bind_trigger_to_matching_session(trigger, state); |
| 2414 | if (ret) { |
| 2415 | goto error_put_client_list; |
| 2416 | } |
| 2417 | break; |
| 2418 | case LTTNG_OBJECT_TYPE_CHANNEL: |
| 2419 | /* |
| 2420 | * Add the trigger to list of triggers bound to the channels |
| 2421 | * currently known. |
| 2422 | */ |
| 2423 | ret = bind_trigger_to_matching_channels(trigger, state); |
| 2424 | if (ret) { |
| 2425 | goto error_put_client_list; |
| 2426 | } |
| 2427 | break; |
| 2428 | case LTTNG_OBJECT_TYPE_NONE: |
| 2429 | break; |
| 2430 | default: |
| 2431 | ERR("Unknown object type on which to bind a newly registered trigger was encountered"); |
| 2432 | ret = -1; |
| 2433 | goto error_put_client_list; |
| 2434 | } |
| 2435 | |
| 2436 | /* |
| 2437 | * The new trigger's condition must be evaluated against the current |
| 2438 | * state. |
| 2439 | * |
| 2440 | * In the case of `notify` action, nothing preventing clients from |
| 2441 | * subscribing to a condition before the corresponding trigger is |
| 2442 | * registered, we have to evaluate this new condition right away. |
| 2443 | * |
| 2444 | * At some point, we were waiting for the next "evaluation" (e.g. on |
| 2445 | * reception of a channel sample) to evaluate this new condition, but |
| 2446 | * that was broken. |
| 2447 | * |
| 2448 | * The reason it was broken is that waiting for the next sample |
| 2449 | * does not allow us to properly handle transitions for edge-triggered |
| 2450 | * conditions. |
| 2451 | * |
| 2452 | * Consider this example: when we handle a new channel sample, we |
| 2453 | * evaluate each conditions twice: once with the previous state, and |
| 2454 | * again with the newest state. We then use those two results to |
| 2455 | * determine whether a state change happened: a condition was false and |
| 2456 | * became true. If a state change happened, we have to notify clients. |
| 2457 | * |
| 2458 | * Now, if a client subscribes to a given notification and registers |
| 2459 | * a trigger *after* that subscription, we have to make sure the |
| 2460 | * condition is evaluated at this point while considering only the |
| 2461 | * current state. Otherwise, the next evaluation cycle may only see |
| 2462 | * that the evaluations remain the same (true for samples n-1 and n) and |
| 2463 | * the client will never know that the condition has been met. |
| 2464 | */ |
| 2465 | switch (get_condition_binding_object(condition)) { |
| 2466 | case LTTNG_OBJECT_TYPE_SESSION: |
| 2467 | ret = evaluate_session_condition_for_client(condition, state, |
| 2468 | &evaluation, &object_uid, |
| 2469 | &object_gid); |
| 2470 | break; |
| 2471 | case LTTNG_OBJECT_TYPE_CHANNEL: |
| 2472 | ret = evaluate_channel_condition_for_client(condition, state, |
| 2473 | &evaluation, &object_uid, |
| 2474 | &object_gid); |
| 2475 | break; |
| 2476 | case LTTNG_OBJECT_TYPE_NONE: |
| 2477 | ret = 0; |
| 2478 | break; |
| 2479 | case LTTNG_OBJECT_TYPE_UNKNOWN: |
| 2480 | default: |
| 2481 | ret = -1; |
| 2482 | break; |
| 2483 | } |
| 2484 | |
| 2485 | if (ret) { |
| 2486 | /* Fatal error. */ |
| 2487 | goto error_put_client_list; |
| 2488 | } |
| 2489 | |
| 2490 | LTTNG_OPTIONAL_SET(&object_creds.uid, object_uid); |
| 2491 | LTTNG_OPTIONAL_SET(&object_creds.gid, object_gid); |
| 2492 | |
| 2493 | DBG("Newly registered trigger's condition evaluated to %s", |
| 2494 | evaluation ? "true" : "false"); |
| 2495 | if (!evaluation) { |
| 2496 | /* Evaluation yielded nothing. Normal exit. */ |
| 2497 | ret = 0; |
| 2498 | goto end; |
| 2499 | } |
| 2500 | |
| 2501 | /* |
| 2502 | * Ownership of `evaluation` transferred to the action executor |
| 2503 | * no matter the result. |
| 2504 | */ |
| 2505 | executor_status = action_executor_enqueue(state->executor, trigger, |
| 2506 | evaluation, &object_creds, client_list); |
| 2507 | evaluation = NULL; |
| 2508 | switch (executor_status) { |
| 2509 | case ACTION_EXECUTOR_STATUS_OK: |
| 2510 | break; |
| 2511 | case ACTION_EXECUTOR_STATUS_ERROR: |
| 2512 | case ACTION_EXECUTOR_STATUS_INVALID: |
| 2513 | /* |
| 2514 | * TODO Add trigger identification (name/id) when |
| 2515 | * it is added to the API. |
| 2516 | */ |
| 2517 | ERR("Fatal error occurred while enqueuing action associated to newly registered trigger"); |
| 2518 | ret = -1; |
| 2519 | goto error_put_client_list; |
| 2520 | case ACTION_EXECUTOR_STATUS_OVERFLOW: |
| 2521 | /* |
| 2522 | * TODO Add trigger identification (name/id) when |
| 2523 | * it is added to the API. |
| 2524 | * |
| 2525 | * Not a fatal error. |
| 2526 | */ |
| 2527 | WARN("No space left when enqueuing action associated to newly registered trigger"); |
| 2528 | ret = 0; |
| 2529 | goto end; |
| 2530 | default: |
| 2531 | abort(); |
| 2532 | } |
| 2533 | |
| 2534 | end: |
| 2535 | *cmd_result = LTTNG_OK; |
| 2536 | DBG("Registered trigger: name = `%s`, tracer token = %" PRIu64, |
| 2537 | trigger_name, trigger_tracer_token); |
| 2538 | |
| 2539 | error_put_client_list: |
| 2540 | notification_client_list_put(client_list); |
| 2541 | |
| 2542 | error_free_ht_element: |
| 2543 | if (trigger_ht_element) { |
| 2544 | /* Delayed removal due to RCU constraint on delete. */ |
| 2545 | call_rcu(&trigger_ht_element->rcu_node, |
| 2546 | free_lttng_trigger_ht_element_rcu); |
| 2547 | } |
| 2548 | |
| 2549 | error: |
| 2550 | if (free_trigger) { |
| 2551 | lttng_trigger_destroy(trigger); |
| 2552 | } |
| 2553 | rcu_read_unlock(); |
| 2554 | return ret; |
| 2555 | } |
| 2556 | |
| 2557 | static |
| 2558 | void free_lttng_trigger_ht_element_rcu(struct rcu_head *node) |
| 2559 | { |
| 2560 | free(caa_container_of(node, struct lttng_trigger_ht_element, |
| 2561 | rcu_node)); |
| 2562 | } |
| 2563 | |
| 2564 | static |
| 2565 | int handle_notification_thread_command_unregister_trigger( |
| 2566 | struct notification_thread_state *state, |
| 2567 | struct lttng_trigger *trigger, |
| 2568 | enum lttng_error_code *_cmd_reply) |
| 2569 | { |
| 2570 | struct cds_lfht_iter iter; |
| 2571 | struct cds_lfht_node *triggers_ht_node; |
| 2572 | struct lttng_channel_trigger_list *trigger_list; |
| 2573 | struct notification_client_list *client_list; |
| 2574 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 2575 | struct lttng_condition *condition = lttng_trigger_get_condition( |
| 2576 | trigger); |
| 2577 | enum lttng_error_code cmd_reply; |
| 2578 | |
| 2579 | rcu_read_lock(); |
| 2580 | |
| 2581 | cds_lfht_lookup(state->triggers_ht, |
| 2582 | lttng_condition_hash(condition), |
| 2583 | match_trigger, |
| 2584 | trigger, |
| 2585 | &iter); |
| 2586 | triggers_ht_node = cds_lfht_iter_get_node(&iter); |
| 2587 | if (!triggers_ht_node) { |
| 2588 | cmd_reply = LTTNG_ERR_TRIGGER_NOT_FOUND; |
| 2589 | goto end; |
| 2590 | } else { |
| 2591 | cmd_reply = LTTNG_OK; |
| 2592 | } |
| 2593 | |
| 2594 | /* Remove trigger from channel_triggers_ht. */ |
| 2595 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list, |
| 2596 | channel_triggers_ht_node) { |
| 2597 | struct lttng_trigger_list_element *trigger_element, *tmp; |
| 2598 | |
| 2599 | cds_list_for_each_entry_safe(trigger_element, tmp, |
| 2600 | &trigger_list->list, node) { |
| 2601 | if (!lttng_trigger_is_equal(trigger, trigger_element->trigger)) { |
| 2602 | continue; |
| 2603 | } |
| 2604 | |
| 2605 | DBG("[notification-thread] Removed trigger from channel_triggers_ht"); |
| 2606 | cds_list_del(&trigger_element->node); |
| 2607 | /* A trigger can only appear once per channel */ |
| 2608 | break; |
| 2609 | } |
| 2610 | } |
| 2611 | |
| 2612 | if (is_trigger_action_notify(trigger)) { |
| 2613 | /* |
| 2614 | * Remove and release the client list from |
| 2615 | * notification_trigger_clients_ht. |
| 2616 | */ |
| 2617 | client_list = get_client_list_from_condition(state, condition); |
| 2618 | assert(client_list); |
| 2619 | |
| 2620 | /* Put new reference and the hashtable's reference. */ |
| 2621 | notification_client_list_put(client_list); |
| 2622 | notification_client_list_put(client_list); |
| 2623 | client_list = NULL; |
| 2624 | } |
| 2625 | |
| 2626 | /* Remove trigger from triggers_ht. */ |
| 2627 | trigger_ht_element = caa_container_of(triggers_ht_node, |
| 2628 | struct lttng_trigger_ht_element, node); |
| 2629 | cds_lfht_del(state->triggers_by_name_uid_ht, &trigger_ht_element->node_by_name_uid); |
| 2630 | cds_lfht_del(state->triggers_ht, triggers_ht_node); |
| 2631 | |
| 2632 | /* Release the ownership of the trigger. */ |
| 2633 | lttng_trigger_destroy(trigger_ht_element->trigger); |
| 2634 | call_rcu(&trigger_ht_element->rcu_node, free_lttng_trigger_ht_element_rcu); |
| 2635 | end: |
| 2636 | rcu_read_unlock(); |
| 2637 | if (_cmd_reply) { |
| 2638 | *_cmd_reply = cmd_reply; |
| 2639 | } |
| 2640 | return 0; |
| 2641 | } |
| 2642 | |
| 2643 | /* Returns 0 on success, 1 on exit requested, negative value on error. */ |
| 2644 | int handle_notification_thread_command( |
| 2645 | struct notification_thread_handle *handle, |
| 2646 | struct notification_thread_state *state) |
| 2647 | { |
| 2648 | int ret; |
| 2649 | uint64_t counter; |
| 2650 | struct notification_thread_command *cmd; |
| 2651 | |
| 2652 | /* Read the event pipe to put it back into a quiescent state. */ |
| 2653 | ret = lttng_read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter, |
| 2654 | sizeof(counter)); |
| 2655 | if (ret != sizeof(counter)) { |
| 2656 | goto error; |
| 2657 | } |
| 2658 | |
| 2659 | pthread_mutex_lock(&handle->cmd_queue.lock); |
| 2660 | cmd = cds_list_first_entry(&handle->cmd_queue.list, |
| 2661 | struct notification_thread_command, cmd_list_node); |
| 2662 | cds_list_del(&cmd->cmd_list_node); |
| 2663 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
| 2664 | switch (cmd->type) { |
| 2665 | case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: |
| 2666 | DBG("[notification-thread] Received register trigger command"); |
| 2667 | ret = handle_notification_thread_command_register_trigger( |
| 2668 | state, cmd->parameters.trigger, |
| 2669 | &cmd->reply_code); |
| 2670 | break; |
| 2671 | case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: |
| 2672 | DBG("[notification-thread] Received unregister trigger command"); |
| 2673 | ret = handle_notification_thread_command_unregister_trigger( |
| 2674 | state, cmd->parameters.trigger, |
| 2675 | &cmd->reply_code); |
| 2676 | break; |
| 2677 | case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: |
| 2678 | DBG("[notification-thread] Received add channel command"); |
| 2679 | ret = handle_notification_thread_command_add_channel( |
| 2680 | state, |
| 2681 | cmd->parameters.add_channel.session.name, |
| 2682 | cmd->parameters.add_channel.session.uid, |
| 2683 | cmd->parameters.add_channel.session.gid, |
| 2684 | cmd->parameters.add_channel.channel.name, |
| 2685 | cmd->parameters.add_channel.channel.domain, |
| 2686 | cmd->parameters.add_channel.channel.key, |
| 2687 | cmd->parameters.add_channel.channel.capacity, |
| 2688 | &cmd->reply_code); |
| 2689 | break; |
| 2690 | case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: |
| 2691 | DBG("[notification-thread] Received remove channel command"); |
| 2692 | ret = handle_notification_thread_command_remove_channel( |
| 2693 | state, cmd->parameters.remove_channel.key, |
| 2694 | cmd->parameters.remove_channel.domain, |
| 2695 | &cmd->reply_code); |
| 2696 | break; |
| 2697 | case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING: |
| 2698 | case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED: |
| 2699 | DBG("[notification-thread] Received session rotation %s command", |
| 2700 | cmd->type == NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING ? |
| 2701 | "ongoing" : "completed"); |
| 2702 | ret = handle_notification_thread_command_session_rotation( |
| 2703 | state, |
| 2704 | cmd->type, |
| 2705 | cmd->parameters.session_rotation.session_name, |
| 2706 | cmd->parameters.session_rotation.uid, |
| 2707 | cmd->parameters.session_rotation.gid, |
| 2708 | cmd->parameters.session_rotation.trace_archive_chunk_id, |
| 2709 | cmd->parameters.session_rotation.location, |
| 2710 | &cmd->reply_code); |
| 2711 | break; |
| 2712 | case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS: |
| 2713 | { |
| 2714 | struct lttng_triggers *triggers = NULL; |
| 2715 | |
| 2716 | ret = handle_notification_thread_command_list_triggers( |
| 2717 | handle, |
| 2718 | state, |
| 2719 | cmd->parameters.list_triggers.uid, |
| 2720 | &triggers, |
| 2721 | &cmd->reply_code); |
| 2722 | cmd->reply.list_triggers.triggers = triggers; |
| 2723 | ret = 0; |
| 2724 | break; |
| 2725 | } |
| 2726 | case NOTIFICATION_COMMAND_TYPE_QUIT: |
| 2727 | DBG("[notification-thread] Received quit command"); |
| 2728 | cmd->reply_code = LTTNG_OK; |
| 2729 | ret = 1; |
| 2730 | goto end; |
| 2731 | case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE: |
| 2732 | { |
| 2733 | const enum client_transmission_status client_status = |
| 2734 | cmd->parameters.client_communication_update |
| 2735 | .status; |
| 2736 | const notification_client_id client_id = |
| 2737 | cmd->parameters.client_communication_update.id; |
| 2738 | struct notification_client *client; |
| 2739 | |
| 2740 | rcu_read_lock(); |
| 2741 | client = get_client_from_id(client_id, state); |
| 2742 | |
| 2743 | if (!client) { |
| 2744 | /* |
| 2745 | * Client error was probably already picked-up by the |
| 2746 | * notification thread or it has disconnected |
| 2747 | * gracefully while this command was queued. |
| 2748 | */ |
| 2749 | DBG("Failed to find notification client to update communication status, client id = %" PRIu64, |
| 2750 | client_id); |
| 2751 | ret = 0; |
| 2752 | } else { |
| 2753 | ret = client_handle_transmission_status( |
| 2754 | client, client_status, state); |
| 2755 | } |
| 2756 | rcu_read_unlock(); |
| 2757 | break; |
| 2758 | } |
| 2759 | default: |
| 2760 | ERR("[notification-thread] Unknown internal command received"); |
| 2761 | goto error_unlock; |
| 2762 | } |
| 2763 | |
| 2764 | if (ret) { |
| 2765 | goto error_unlock; |
| 2766 | } |
| 2767 | end: |
| 2768 | if (cmd->is_async) { |
| 2769 | free(cmd); |
| 2770 | cmd = NULL; |
| 2771 | } else { |
| 2772 | lttng_waiter_wake_up(&cmd->reply_waiter); |
| 2773 | } |
| 2774 | return ret; |
| 2775 | error_unlock: |
| 2776 | /* Wake-up and return a fatal error to the calling thread. */ |
| 2777 | lttng_waiter_wake_up(&cmd->reply_waiter); |
| 2778 | cmd->reply_code = LTTNG_ERR_FATAL; |
| 2779 | error: |
| 2780 | /* Indicate a fatal error to the caller. */ |
| 2781 | return -1; |
| 2782 | } |
| 2783 | |
| 2784 | static |
| 2785 | int socket_set_non_blocking(int socket) |
| 2786 | { |
| 2787 | int ret, flags; |
| 2788 | |
| 2789 | /* Set the pipe as non-blocking. */ |
| 2790 | ret = fcntl(socket, F_GETFL, 0); |
| 2791 | if (ret == -1) { |
| 2792 | PERROR("fcntl get socket flags"); |
| 2793 | goto end; |
| 2794 | } |
| 2795 | flags = ret; |
| 2796 | |
| 2797 | ret = fcntl(socket, F_SETFL, flags | O_NONBLOCK); |
| 2798 | if (ret == -1) { |
| 2799 | PERROR("fcntl set O_NONBLOCK socket flag"); |
| 2800 | goto end; |
| 2801 | } |
| 2802 | DBG("Client socket (fd = %i) set as non-blocking", socket); |
| 2803 | end: |
| 2804 | return ret; |
| 2805 | } |
| 2806 | |
| 2807 | static |
| 2808 | int client_reset_inbound_state(struct notification_client *client) |
| 2809 | { |
| 2810 | int ret; |
| 2811 | |
| 2812 | |
| 2813 | lttng_payload_clear(&client->communication.inbound.payload); |
| 2814 | |
| 2815 | client->communication.inbound.bytes_to_receive = |
| 2816 | sizeof(struct lttng_notification_channel_message); |
| 2817 | client->communication.inbound.msg_type = |
| 2818 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN; |
| 2819 | LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1); |
| 2820 | LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1); |
| 2821 | ret = lttng_dynamic_buffer_set_size( |
| 2822 | &client->communication.inbound.payload.buffer, |
| 2823 | client->communication.inbound.bytes_to_receive); |
| 2824 | |
| 2825 | return ret; |
| 2826 | } |
| 2827 | |
| 2828 | int handle_notification_thread_client_connect( |
| 2829 | struct notification_thread_state *state) |
| 2830 | { |
| 2831 | int ret; |
| 2832 | struct notification_client *client; |
| 2833 | |
| 2834 | DBG("[notification-thread] Handling new notification channel client connection"); |
| 2835 | |
| 2836 | client = zmalloc(sizeof(*client)); |
| 2837 | if (!client) { |
| 2838 | /* Fatal error. */ |
| 2839 | ret = -1; |
| 2840 | goto error; |
| 2841 | } |
| 2842 | |
| 2843 | pthread_mutex_init(&client->lock, NULL); |
| 2844 | client->id = state->next_notification_client_id++; |
| 2845 | CDS_INIT_LIST_HEAD(&client->condition_list); |
| 2846 | lttng_payload_init(&client->communication.inbound.payload); |
| 2847 | lttng_payload_init(&client->communication.outbound.payload); |
| 2848 | client->communication.inbound.expect_creds = true; |
| 2849 | |
| 2850 | ret = client_reset_inbound_state(client); |
| 2851 | if (ret) { |
| 2852 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 2853 | ret = 0; |
| 2854 | goto error; |
| 2855 | } |
| 2856 | |
| 2857 | ret = lttcomm_accept_unix_sock(state->notification_channel_socket); |
| 2858 | if (ret < 0) { |
| 2859 | ERR("[notification-thread] Failed to accept new notification channel client connection"); |
| 2860 | ret = 0; |
| 2861 | goto error; |
| 2862 | } |
| 2863 | |
| 2864 | client->socket = ret; |
| 2865 | |
| 2866 | ret = socket_set_non_blocking(client->socket); |
| 2867 | if (ret) { |
| 2868 | ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking"); |
| 2869 | goto error; |
| 2870 | } |
| 2871 | |
| 2872 | ret = lttcomm_setsockopt_creds_unix_sock(client->socket); |
| 2873 | if (ret < 0) { |
| 2874 | ERR("[notification-thread] Failed to set socket options on new notification channel client socket"); |
| 2875 | ret = 0; |
| 2876 | goto error; |
| 2877 | } |
| 2878 | |
| 2879 | ret = lttng_poll_add(&state->events, client->socket, |
| 2880 | LPOLLIN | LPOLLERR | |
| 2881 | LPOLLHUP | LPOLLRDHUP); |
| 2882 | if (ret < 0) { |
| 2883 | ERR("[notification-thread] Failed to add notification channel client socket to poll set"); |
| 2884 | ret = 0; |
| 2885 | goto error; |
| 2886 | } |
| 2887 | DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", |
| 2888 | client->socket); |
| 2889 | |
| 2890 | rcu_read_lock(); |
| 2891 | cds_lfht_add(state->client_socket_ht, |
| 2892 | hash_client_socket(client->socket), |
| 2893 | &client->client_socket_ht_node); |
| 2894 | cds_lfht_add(state->client_id_ht, |
| 2895 | hash_client_id(client->id), |
| 2896 | &client->client_id_ht_node); |
| 2897 | rcu_read_unlock(); |
| 2898 | |
| 2899 | return ret; |
| 2900 | |
| 2901 | error: |
| 2902 | notification_client_destroy(client, state); |
| 2903 | return ret; |
| 2904 | } |
| 2905 | |
| 2906 | /* |
| 2907 | * RCU read-lock must be held by the caller. |
| 2908 | * Client lock must _not_ be held by the caller. |
| 2909 | */ |
| 2910 | static |
| 2911 | int notification_thread_client_disconnect( |
| 2912 | struct notification_client *client, |
| 2913 | struct notification_thread_state *state) |
| 2914 | { |
| 2915 | int ret; |
| 2916 | struct lttng_condition_list_element *condition_list_element, *tmp; |
| 2917 | |
| 2918 | /* Acquire the client lock to disable its communication atomically. */ |
| 2919 | pthread_mutex_lock(&client->lock); |
| 2920 | client->communication.active = false; |
| 2921 | cds_lfht_del(state->client_socket_ht, &client->client_socket_ht_node); |
| 2922 | cds_lfht_del(state->client_id_ht, &client->client_id_ht_node); |
| 2923 | pthread_mutex_unlock(&client->lock); |
| 2924 | |
| 2925 | ret = lttng_poll_del(&state->events, client->socket); |
| 2926 | if (ret) { |
| 2927 | ERR("[notification-thread] Failed to remove client socket %d from poll set", |
| 2928 | client->socket); |
| 2929 | } |
| 2930 | |
| 2931 | /* Release all conditions to which the client was subscribed. */ |
| 2932 | cds_list_for_each_entry_safe(condition_list_element, tmp, |
| 2933 | &client->condition_list, node) { |
| 2934 | (void) notification_thread_client_unsubscribe(client, |
| 2935 | condition_list_element->condition, state, NULL); |
| 2936 | } |
| 2937 | |
| 2938 | /* |
| 2939 | * Client no longer accessible to other threads (through the |
| 2940 | * client lists). |
| 2941 | */ |
| 2942 | notification_client_destroy(client, state); |
| 2943 | return ret; |
| 2944 | } |
| 2945 | |
| 2946 | int handle_notification_thread_client_disconnect( |
| 2947 | int client_socket, struct notification_thread_state *state) |
| 2948 | { |
| 2949 | int ret = 0; |
| 2950 | struct notification_client *client; |
| 2951 | |
| 2952 | rcu_read_lock(); |
| 2953 | DBG("[notification-thread] Closing client connection (socket fd = %i)", |
| 2954 | client_socket); |
| 2955 | client = get_client_from_socket(client_socket, state); |
| 2956 | if (!client) { |
| 2957 | /* Internal state corruption, fatal error. */ |
| 2958 | ERR("[notification-thread] Unable to find client (socket fd = %i)", |
| 2959 | client_socket); |
| 2960 | ret = -1; |
| 2961 | goto end; |
| 2962 | } |
| 2963 | |
| 2964 | ret = notification_thread_client_disconnect(client, state); |
| 2965 | end: |
| 2966 | rcu_read_unlock(); |
| 2967 | return ret; |
| 2968 | } |
| 2969 | |
| 2970 | int handle_notification_thread_client_disconnect_all( |
| 2971 | struct notification_thread_state *state) |
| 2972 | { |
| 2973 | struct cds_lfht_iter iter; |
| 2974 | struct notification_client *client; |
| 2975 | bool error_encoutered = false; |
| 2976 | |
| 2977 | rcu_read_lock(); |
| 2978 | DBG("[notification-thread] Closing all client connections"); |
| 2979 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, |
| 2980 | client_socket_ht_node) { |
| 2981 | int ret; |
| 2982 | |
| 2983 | ret = notification_thread_client_disconnect( |
| 2984 | client, state); |
| 2985 | if (ret) { |
| 2986 | error_encoutered = true; |
| 2987 | } |
| 2988 | } |
| 2989 | rcu_read_unlock(); |
| 2990 | return error_encoutered ? 1 : 0; |
| 2991 | } |
| 2992 | |
| 2993 | int handle_notification_thread_trigger_unregister_all( |
| 2994 | struct notification_thread_state *state) |
| 2995 | { |
| 2996 | bool error_occurred = false; |
| 2997 | struct cds_lfht_iter iter; |
| 2998 | struct lttng_trigger_ht_element *trigger_ht_element; |
| 2999 | |
| 3000 | rcu_read_lock(); |
| 3001 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 3002 | node) { |
| 3003 | int ret = handle_notification_thread_command_unregister_trigger( |
| 3004 | state, trigger_ht_element->trigger, NULL); |
| 3005 | if (ret) { |
| 3006 | error_occurred = true; |
| 3007 | } |
| 3008 | } |
| 3009 | rcu_read_unlock(); |
| 3010 | return error_occurred ? -1 : 0; |
| 3011 | } |
| 3012 | |
| 3013 | static |
| 3014 | int client_handle_transmission_status( |
| 3015 | struct notification_client *client, |
| 3016 | enum client_transmission_status transmission_status, |
| 3017 | struct notification_thread_state *state) |
| 3018 | { |
| 3019 | int ret = 0; |
| 3020 | |
| 3021 | switch (transmission_status) { |
| 3022 | case CLIENT_TRANSMISSION_STATUS_COMPLETE: |
| 3023 | ret = lttng_poll_mod(&state->events, client->socket, |
| 3024 | CLIENT_POLL_MASK_IN); |
| 3025 | if (ret) { |
| 3026 | goto end; |
| 3027 | } |
| 3028 | |
| 3029 | break; |
| 3030 | case CLIENT_TRANSMISSION_STATUS_QUEUED: |
| 3031 | /* |
| 3032 | * We want to be notified whenever there is buffer space |
| 3033 | * available to send the rest of the payload. |
| 3034 | */ |
| 3035 | ret = lttng_poll_mod(&state->events, client->socket, |
| 3036 | CLIENT_POLL_MASK_IN_OUT); |
| 3037 | if (ret) { |
| 3038 | goto end; |
| 3039 | } |
| 3040 | break; |
| 3041 | case CLIENT_TRANSMISSION_STATUS_FAIL: |
| 3042 | ret = notification_thread_client_disconnect(client, state); |
| 3043 | if (ret) { |
| 3044 | goto end; |
| 3045 | } |
| 3046 | break; |
| 3047 | case CLIENT_TRANSMISSION_STATUS_ERROR: |
| 3048 | ret = -1; |
| 3049 | goto end; |
| 3050 | default: |
| 3051 | abort(); |
| 3052 | } |
| 3053 | end: |
| 3054 | return ret; |
| 3055 | } |
| 3056 | |
| 3057 | /* Client lock must be acquired by caller. */ |
| 3058 | static |
| 3059 | enum client_transmission_status client_flush_outgoing_queue( |
| 3060 | struct notification_client *client) |
| 3061 | { |
| 3062 | ssize_t ret; |
| 3063 | size_t to_send_count; |
| 3064 | enum client_transmission_status status; |
| 3065 | struct lttng_payload_view pv = lttng_payload_view_from_payload( |
| 3066 | &client->communication.outbound.payload, 0, -1); |
| 3067 | const int fds_to_send_count = |
| 3068 | lttng_payload_view_get_fd_handle_count(&pv); |
| 3069 | |
| 3070 | ASSERT_LOCKED(client->lock); |
| 3071 | |
| 3072 | if (!client->communication.active) { |
| 3073 | status = CLIENT_TRANSMISSION_STATUS_FAIL; |
| 3074 | goto end; |
| 3075 | } |
| 3076 | |
| 3077 | if (pv.buffer.size == 0) { |
| 3078 | /* |
| 3079 | * If both data and fds are equal to zero, we are in an invalid |
| 3080 | * state. |
| 3081 | */ |
| 3082 | assert(fds_to_send_count != 0); |
| 3083 | goto send_fds; |
| 3084 | } |
| 3085 | |
| 3086 | /* Send data. */ |
| 3087 | to_send_count = pv.buffer.size; |
| 3088 | DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", |
| 3089 | client->socket); |
| 3090 | |
| 3091 | ret = lttcomm_send_unix_sock_non_block(client->socket, |
| 3092 | pv.buffer.data, |
| 3093 | to_send_count); |
| 3094 | if ((ret >= 0 && ret < to_send_count)) { |
| 3095 | DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", |
| 3096 | client->socket); |
| 3097 | to_send_count -= max(ret, 0); |
| 3098 | |
| 3099 | memmove(client->communication.outbound.payload.buffer.data, |
| 3100 | pv.buffer.data + |
| 3101 | pv.buffer.size - to_send_count, |
| 3102 | to_send_count); |
| 3103 | ret = lttng_dynamic_buffer_set_size( |
| 3104 | &client->communication.outbound.payload.buffer, |
| 3105 | to_send_count); |
| 3106 | if (ret) { |
| 3107 | goto error; |
| 3108 | } |
| 3109 | |
| 3110 | status = CLIENT_TRANSMISSION_STATUS_QUEUED; |
| 3111 | goto end; |
| 3112 | } else if (ret < 0) { |
| 3113 | /* Generic error, disable the client's communication. */ |
| 3114 | ERR("[notification-thread] Failed to flush outgoing queue, disconnecting client (socket fd = %i)", |
| 3115 | client->socket); |
| 3116 | client->communication.active = false; |
| 3117 | status = CLIENT_TRANSMISSION_STATUS_FAIL; |
| 3118 | goto end; |
| 3119 | } else { |
| 3120 | /* |
| 3121 | * No error and flushed the queue completely. |
| 3122 | * |
| 3123 | * The payload buffer size is used later to |
| 3124 | * check if there is notifications queued. So albeit that the |
| 3125 | * direct caller knows that the transmission is complete, we |
| 3126 | * need to set the buffer size to zero. |
| 3127 | */ |
| 3128 | ret = lttng_dynamic_buffer_set_size( |
| 3129 | &client->communication.outbound.payload.buffer, 0); |
| 3130 | if (ret) { |
| 3131 | goto error; |
| 3132 | } |
| 3133 | } |
| 3134 | |
| 3135 | send_fds: |
| 3136 | /* No fds to send, transmission is complete. */ |
| 3137 | if (fds_to_send_count == 0) { |
| 3138 | status = CLIENT_TRANSMISSION_STATUS_COMPLETE; |
| 3139 | goto end; |
| 3140 | } |
| 3141 | |
| 3142 | ret = lttcomm_send_payload_view_fds_unix_sock_non_block( |
| 3143 | client->socket, &pv); |
| 3144 | if (ret < 0) { |
| 3145 | /* Generic error, disable the client's communication. */ |
| 3146 | ERR("[notification-thread] Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)", |
| 3147 | client->socket); |
| 3148 | client->communication.active = false; |
| 3149 | status = CLIENT_TRANSMISSION_STATUS_FAIL; |
| 3150 | goto end; |
| 3151 | } else if (ret == 0) { |
| 3152 | /* Nothing could be sent. */ |
| 3153 | status = CLIENT_TRANSMISSION_STATUS_QUEUED; |
| 3154 | } else { |
| 3155 | /* Fd passing is an all or nothing kind of thing. */ |
| 3156 | status = CLIENT_TRANSMISSION_STATUS_COMPLETE; |
| 3157 | /* |
| 3158 | * The payload _fd_array count is used later to |
| 3159 | * check if there is notifications queued. So although the |
| 3160 | * direct caller knows that the transmission is complete, we |
| 3161 | * need to clear the _fd_array for the queuing check. |
| 3162 | */ |
| 3163 | lttng_dynamic_pointer_array_clear( |
| 3164 | &client->communication.outbound.payload |
| 3165 | ._fd_handles); |
| 3166 | } |
| 3167 | |
| 3168 | end: |
| 3169 | if (status == CLIENT_TRANSMISSION_STATUS_COMPLETE) { |
| 3170 | client->communication.outbound.queued_command_reply = false; |
| 3171 | client->communication.outbound.dropped_notification = false; |
| 3172 | lttng_payload_clear(&client->communication.outbound.payload); |
| 3173 | } |
| 3174 | |
| 3175 | return status; |
| 3176 | error: |
| 3177 | return CLIENT_TRANSMISSION_STATUS_ERROR; |
| 3178 | } |
| 3179 | |
| 3180 | static |
| 3181 | bool client_has_outbound_data_left( |
| 3182 | const struct notification_client *client) |
| 3183 | { |
| 3184 | const struct lttng_payload_view pv = lttng_payload_view_from_payload( |
| 3185 | &client->communication.outbound.payload, 0, -1); |
| 3186 | const bool has_data = pv.buffer.size != 0; |
| 3187 | const bool has_fds = lttng_payload_view_get_fd_handle_count(&pv); |
| 3188 | |
| 3189 | return has_data || has_fds; |
| 3190 | } |
| 3191 | |
| 3192 | /* Client lock must _not_ be held by the caller. */ |
| 3193 | static |
| 3194 | int client_send_command_reply(struct notification_client *client, |
| 3195 | struct notification_thread_state *state, |
| 3196 | enum lttng_notification_channel_status status) |
| 3197 | { |
| 3198 | int ret; |
| 3199 | struct lttng_notification_channel_command_reply reply = { |
| 3200 | .status = (int8_t) status, |
| 3201 | }; |
| 3202 | struct lttng_notification_channel_message msg = { |
| 3203 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY, |
| 3204 | .size = sizeof(reply), |
| 3205 | }; |
| 3206 | char buffer[sizeof(msg) + sizeof(reply)]; |
| 3207 | enum client_transmission_status transmission_status; |
| 3208 | |
| 3209 | memcpy(buffer, &msg, sizeof(msg)); |
| 3210 | memcpy(buffer + sizeof(msg), &reply, sizeof(reply)); |
| 3211 | DBG("[notification-thread] Send command reply (%i)", (int) status); |
| 3212 | |
| 3213 | pthread_mutex_lock(&client->lock); |
| 3214 | if (client->communication.outbound.queued_command_reply) { |
| 3215 | /* Protocol error. */ |
| 3216 | goto error_unlock; |
| 3217 | } |
| 3218 | |
| 3219 | /* Enqueue buffer to outgoing queue and flush it. */ |
| 3220 | ret = lttng_dynamic_buffer_append( |
| 3221 | &client->communication.outbound.payload.buffer, |
| 3222 | buffer, sizeof(buffer)); |
| 3223 | if (ret) { |
| 3224 | goto error_unlock; |
| 3225 | } |
| 3226 | |
| 3227 | transmission_status = client_flush_outgoing_queue(client); |
| 3228 | |
| 3229 | if (client_has_outbound_data_left(client)) { |
| 3230 | /* Queue could not be emptied. */ |
| 3231 | client->communication.outbound.queued_command_reply = true; |
| 3232 | } |
| 3233 | |
| 3234 | pthread_mutex_unlock(&client->lock); |
| 3235 | ret = client_handle_transmission_status( |
| 3236 | client, transmission_status, state); |
| 3237 | if (ret) { |
| 3238 | goto error; |
| 3239 | } |
| 3240 | |
| 3241 | return 0; |
| 3242 | error_unlock: |
| 3243 | pthread_mutex_unlock(&client->lock); |
| 3244 | error: |
| 3245 | return -1; |
| 3246 | } |
| 3247 | |
| 3248 | static |
| 3249 | int client_handle_message_unknown(struct notification_client *client, |
| 3250 | struct notification_thread_state *state) |
| 3251 | { |
| 3252 | int ret; |
| 3253 | /* |
| 3254 | * Receiving message header. The function will be called again |
| 3255 | * once the rest of the message as been received and can be |
| 3256 | * interpreted. |
| 3257 | */ |
| 3258 | const struct lttng_notification_channel_message *msg; |
| 3259 | |
| 3260 | assert(sizeof(*msg) == client->communication.inbound.payload.buffer.size); |
| 3261 | msg = (const struct lttng_notification_channel_message *) |
| 3262 | client->communication.inbound.payload.buffer.data; |
| 3263 | |
| 3264 | if (msg->size == 0 || |
| 3265 | msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { |
| 3266 | ERR("[notification-thread] Invalid notification channel message: length = %u", |
| 3267 | msg->size); |
| 3268 | ret = -1; |
| 3269 | goto end; |
| 3270 | } |
| 3271 | |
| 3272 | switch (msg->type) { |
| 3273 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: |
| 3274 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: |
| 3275 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: |
| 3276 | break; |
| 3277 | default: |
| 3278 | ret = -1; |
| 3279 | ERR("[notification-thread] Invalid notification channel message: unexpected message type"); |
| 3280 | goto end; |
| 3281 | } |
| 3282 | |
| 3283 | client->communication.inbound.bytes_to_receive = msg->size; |
| 3284 | client->communication.inbound.fds_to_receive = msg->fds; |
| 3285 | client->communication.inbound.msg_type = |
| 3286 | (enum lttng_notification_channel_message_type) msg->type; |
| 3287 | ret = lttng_dynamic_buffer_set_size( |
| 3288 | &client->communication.inbound.payload.buffer, msg->size); |
| 3289 | |
| 3290 | /* msg is not valid anymore due to lttng_dynamic_buffer_set_size. */ |
| 3291 | msg = NULL; |
| 3292 | end: |
| 3293 | return ret; |
| 3294 | } |
| 3295 | |
| 3296 | static |
| 3297 | int client_handle_message_handshake(struct notification_client *client, |
| 3298 | struct notification_thread_state *state) |
| 3299 | { |
| 3300 | int ret; |
| 3301 | struct lttng_notification_channel_command_handshake *handshake_client; |
| 3302 | const struct lttng_notification_channel_command_handshake handshake_reply = { |
| 3303 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, |
| 3304 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, |
| 3305 | }; |
| 3306 | const struct lttng_notification_channel_message msg_header = { |
| 3307 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, |
| 3308 | .size = sizeof(handshake_reply), |
| 3309 | }; |
| 3310 | enum lttng_notification_channel_status status = |
| 3311 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 3312 | char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)]; |
| 3313 | |
| 3314 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); |
| 3315 | memcpy(send_buffer + sizeof(msg_header), &handshake_reply, |
| 3316 | sizeof(handshake_reply)); |
| 3317 | |
| 3318 | handshake_client = |
| 3319 | (struct lttng_notification_channel_command_handshake *) |
| 3320 | client->communication.inbound.payload.buffer |
| 3321 | .data; |
| 3322 | client->major = handshake_client->major; |
| 3323 | client->minor = handshake_client->minor; |
| 3324 | if (!client->communication.inbound.creds_received) { |
| 3325 | ERR("[notification-thread] No credentials received from client"); |
| 3326 | ret = -1; |
| 3327 | goto end; |
| 3328 | } |
| 3329 | |
| 3330 | client->uid = LTTNG_SOCK_GET_UID_CRED( |
| 3331 | &client->communication.inbound.creds); |
| 3332 | client->gid = LTTNG_SOCK_GET_GID_CRED( |
| 3333 | &client->communication.inbound.creds); |
| 3334 | DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", |
| 3335 | client->uid, client->gid, (int) client->major, |
| 3336 | (int) client->minor); |
| 3337 | |
| 3338 | if (handshake_client->major != |
| 3339 | LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { |
| 3340 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION; |
| 3341 | } |
| 3342 | |
| 3343 | pthread_mutex_lock(&client->lock); |
| 3344 | /* Outgoing queue will be flushed when the command reply is sent. */ |
| 3345 | ret = lttng_dynamic_buffer_append( |
| 3346 | &client->communication.outbound.payload.buffer, send_buffer, |
| 3347 | sizeof(send_buffer)); |
| 3348 | if (ret) { |
| 3349 | ERR("[notification-thread] Failed to send protocol version to notification channel client"); |
| 3350 | goto end_unlock; |
| 3351 | } |
| 3352 | |
| 3353 | client->validated = true; |
| 3354 | client->communication.active = true; |
| 3355 | pthread_mutex_unlock(&client->lock); |
| 3356 | |
| 3357 | /* Set reception state to receive the next message header. */ |
| 3358 | ret = client_reset_inbound_state(client); |
| 3359 | if (ret) { |
| 3360 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 3361 | goto end; |
| 3362 | } |
| 3363 | |
| 3364 | /* Flushes the outgoing queue. */ |
| 3365 | ret = client_send_command_reply(client, state, status); |
| 3366 | if (ret) { |
| 3367 | ERR("[notification-thread] Failed to send reply to notification channel client"); |
| 3368 | goto end; |
| 3369 | } |
| 3370 | |
| 3371 | goto end; |
| 3372 | end_unlock: |
| 3373 | pthread_mutex_unlock(&client->lock); |
| 3374 | end: |
| 3375 | return ret; |
| 3376 | } |
| 3377 | |
| 3378 | static |
| 3379 | int client_handle_message_subscription( |
| 3380 | struct notification_client *client, |
| 3381 | enum lttng_notification_channel_message_type msg_type, |
| 3382 | struct notification_thread_state *state) |
| 3383 | { |
| 3384 | int ret; |
| 3385 | struct lttng_condition *condition; |
| 3386 | enum lttng_notification_channel_status status = |
| 3387 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 3388 | struct lttng_payload_view condition_view = |
| 3389 | lttng_payload_view_from_payload( |
| 3390 | &client->communication.inbound.payload, |
| 3391 | 0, -1); |
| 3392 | size_t expected_condition_size; |
| 3393 | |
| 3394 | /* |
| 3395 | * No need to lock client to sample the inbound state as the only |
| 3396 | * other thread accessing clients (action executor) only uses the |
| 3397 | * outbound state. |
| 3398 | */ |
| 3399 | expected_condition_size = client->communication.inbound.payload.buffer.size; |
| 3400 | ret = lttng_condition_create_from_payload(&condition_view, &condition); |
| 3401 | if (ret != expected_condition_size) { |
| 3402 | ERR("[notification-thread] Malformed condition received from client"); |
| 3403 | goto end; |
| 3404 | } |
| 3405 | |
| 3406 | if (msg_type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { |
| 3407 | ret = notification_thread_client_subscribe( |
| 3408 | client, condition, state, &status); |
| 3409 | } else { |
| 3410 | ret = notification_thread_client_unsubscribe( |
| 3411 | client, condition, state, &status); |
| 3412 | } |
| 3413 | |
| 3414 | if (ret) { |
| 3415 | goto end; |
| 3416 | } |
| 3417 | |
| 3418 | /* Set reception state to receive the next message header. */ |
| 3419 | ret = client_reset_inbound_state(client); |
| 3420 | if (ret) { |
| 3421 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 3422 | goto end; |
| 3423 | } |
| 3424 | |
| 3425 | ret = client_send_command_reply(client, state, status); |
| 3426 | if (ret) { |
| 3427 | ERR("[notification-thread] Failed to send reply to notification channel client"); |
| 3428 | goto end; |
| 3429 | } |
| 3430 | |
| 3431 | end: |
| 3432 | return ret; |
| 3433 | } |
| 3434 | |
| 3435 | static |
| 3436 | int client_dispatch_message(struct notification_client *client, |
| 3437 | struct notification_thread_state *state) |
| 3438 | { |
| 3439 | int ret = 0; |
| 3440 | |
| 3441 | if (client->communication.inbound.msg_type != |
| 3442 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE && |
| 3443 | client->communication.inbound.msg_type != |
| 3444 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN && |
| 3445 | !client->validated) { |
| 3446 | WARN("[notification-thread] client attempted a command before handshake"); |
| 3447 | ret = -1; |
| 3448 | goto end; |
| 3449 | } |
| 3450 | |
| 3451 | switch (client->communication.inbound.msg_type) { |
| 3452 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN: |
| 3453 | { |
| 3454 | ret = client_handle_message_unknown(client, state); |
| 3455 | break; |
| 3456 | } |
| 3457 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: |
| 3458 | { |
| 3459 | ret = client_handle_message_handshake(client, state); |
| 3460 | break; |
| 3461 | } |
| 3462 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: |
| 3463 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: |
| 3464 | { |
| 3465 | ret = client_handle_message_subscription(client, |
| 3466 | client->communication.inbound.msg_type, state); |
| 3467 | break; |
| 3468 | } |
| 3469 | default: |
| 3470 | abort(); |
| 3471 | } |
| 3472 | end: |
| 3473 | return ret; |
| 3474 | } |
| 3475 | |
| 3476 | /* Incoming data from client. */ |
| 3477 | int handle_notification_thread_client_in( |
| 3478 | struct notification_thread_state *state, int socket) |
| 3479 | { |
| 3480 | int ret = 0; |
| 3481 | struct notification_client *client; |
| 3482 | ssize_t recv_ret; |
| 3483 | size_t offset; |
| 3484 | |
| 3485 | rcu_read_lock(); |
| 3486 | client = get_client_from_socket(socket, state); |
| 3487 | if (!client) { |
| 3488 | /* Internal error, abort. */ |
| 3489 | ret = -1; |
| 3490 | goto end; |
| 3491 | } |
| 3492 | |
| 3493 | offset = client->communication.inbound.payload.buffer.size - |
| 3494 | client->communication.inbound.bytes_to_receive; |
| 3495 | if (client->communication.inbound.expect_creds) { |
| 3496 | recv_ret = lttcomm_recv_creds_unix_sock(socket, |
| 3497 | client->communication.inbound.payload.buffer.data + offset, |
| 3498 | client->communication.inbound.bytes_to_receive, |
| 3499 | &client->communication.inbound.creds); |
| 3500 | if (recv_ret > 0) { |
| 3501 | client->communication.inbound.expect_creds = false; |
| 3502 | client->communication.inbound.creds_received = true; |
| 3503 | } |
| 3504 | } else { |
| 3505 | recv_ret = lttcomm_recv_unix_sock_non_block(socket, |
| 3506 | client->communication.inbound.payload.buffer.data + offset, |
| 3507 | client->communication.inbound.bytes_to_receive); |
| 3508 | } |
| 3509 | if (recv_ret >= 0) { |
| 3510 | client->communication.inbound.bytes_to_receive -= recv_ret; |
| 3511 | } else { |
| 3512 | goto error_disconnect_client; |
| 3513 | } |
| 3514 | |
| 3515 | if (client->communication.inbound.bytes_to_receive != 0) { |
| 3516 | /* Message incomplete wait for more data. */ |
| 3517 | ret = 0; |
| 3518 | goto end; |
| 3519 | } |
| 3520 | |
| 3521 | assert(client->communication.inbound.bytes_to_receive == 0); |
| 3522 | |
| 3523 | /* Receive fds. */ |
| 3524 | if (client->communication.inbound.fds_to_receive != 0) { |
| 3525 | ret = lttcomm_recv_payload_fds_unix_sock_non_block( |
| 3526 | client->socket, |
| 3527 | client->communication.inbound.fds_to_receive, |
| 3528 | &client->communication.inbound.payload); |
| 3529 | if (ret > 0) { |
| 3530 | /* |
| 3531 | * Fds received. non blocking fds passing is all |
| 3532 | * or nothing. |
| 3533 | */ |
| 3534 | ssize_t expected_size; |
| 3535 | |
| 3536 | expected_size = sizeof(int) * |
| 3537 | client->communication.inbound |
| 3538 | .fds_to_receive; |
| 3539 | assert(ret == expected_size); |
| 3540 | client->communication.inbound.fds_to_receive = 0; |
| 3541 | } else if (ret == 0) { |
| 3542 | /* Received nothing. */ |
| 3543 | ret = 0; |
| 3544 | goto end; |
| 3545 | } else { |
| 3546 | goto error_disconnect_client; |
| 3547 | } |
| 3548 | } |
| 3549 | |
| 3550 | /* At this point the message is complete.*/ |
| 3551 | assert(client->communication.inbound.bytes_to_receive == 0 && |
| 3552 | client->communication.inbound.fds_to_receive == 0); |
| 3553 | ret = client_dispatch_message(client, state); |
| 3554 | if (ret) { |
| 3555 | /* |
| 3556 | * Only returns an error if this client must be |
| 3557 | * disconnected. |
| 3558 | */ |
| 3559 | goto error_disconnect_client; |
| 3560 | } |
| 3561 | |
| 3562 | end: |
| 3563 | rcu_read_unlock(); |
| 3564 | return ret; |
| 3565 | |
| 3566 | error_disconnect_client: |
| 3567 | ret = notification_thread_client_disconnect(client, state); |
| 3568 | goto end; |
| 3569 | } |
| 3570 | |
| 3571 | /* Client ready to receive outgoing data. */ |
| 3572 | int handle_notification_thread_client_out( |
| 3573 | struct notification_thread_state *state, int socket) |
| 3574 | { |
| 3575 | int ret; |
| 3576 | struct notification_client *client; |
| 3577 | enum client_transmission_status transmission_status; |
| 3578 | |
| 3579 | rcu_read_lock(); |
| 3580 | client = get_client_from_socket(socket, state); |
| 3581 | if (!client) { |
| 3582 | /* Internal error, abort. */ |
| 3583 | ret = -1; |
| 3584 | goto end; |
| 3585 | } |
| 3586 | |
| 3587 | pthread_mutex_lock(&client->lock); |
| 3588 | transmission_status = client_flush_outgoing_queue(client); |
| 3589 | pthread_mutex_unlock(&client->lock); |
| 3590 | |
| 3591 | ret = client_handle_transmission_status( |
| 3592 | client, transmission_status, state); |
| 3593 | if (ret) { |
| 3594 | goto end; |
| 3595 | } |
| 3596 | end: |
| 3597 | rcu_read_unlock(); |
| 3598 | return ret; |
| 3599 | } |
| 3600 | |
| 3601 | static |
| 3602 | bool evaluate_buffer_usage_condition(const struct lttng_condition *condition, |
| 3603 | const struct channel_state_sample *sample, |
| 3604 | uint64_t buffer_capacity) |
| 3605 | { |
| 3606 | bool result = false; |
| 3607 | uint64_t threshold; |
| 3608 | enum lttng_condition_type condition_type; |
| 3609 | const struct lttng_condition_buffer_usage *use_condition = container_of( |
| 3610 | condition, struct lttng_condition_buffer_usage, |
| 3611 | parent); |
| 3612 | |
| 3613 | if (use_condition->threshold_bytes.set) { |
| 3614 | threshold = use_condition->threshold_bytes.value; |
| 3615 | } else { |
| 3616 | /* |
| 3617 | * Threshold was expressed as a ratio. |
| 3618 | * |
| 3619 | * TODO the threshold (in bytes) of conditions expressed |
| 3620 | * as a ratio of total buffer size could be cached to |
| 3621 | * forego this double-multiplication or it could be performed |
| 3622 | * as fixed-point math. |
| 3623 | * |
| 3624 | * Note that caching should accommodates the case where the |
| 3625 | * condition applies to multiple channels (i.e. don't assume |
| 3626 | * that all channels matching my_chann* have the same size...) |
| 3627 | */ |
| 3628 | threshold = (uint64_t) (use_condition->threshold_ratio.value * |
| 3629 | (double) buffer_capacity); |
| 3630 | } |
| 3631 | |
| 3632 | condition_type = lttng_condition_get_type(condition); |
| 3633 | if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) { |
| 3634 | DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, |
| 3635 | threshold, sample->highest_usage); |
| 3636 | |
| 3637 | /* |
| 3638 | * The low condition should only be triggered once _all_ of the |
| 3639 | * streams in a channel have gone below the "low" threshold. |
| 3640 | */ |
| 3641 | if (sample->highest_usage <= threshold) { |
| 3642 | result = true; |
| 3643 | } |
| 3644 | } else { |
| 3645 | DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, |
| 3646 | threshold, sample->highest_usage); |
| 3647 | |
| 3648 | /* |
| 3649 | * For high buffer usage scenarios, we want to trigger whenever |
| 3650 | * _any_ of the streams has reached the "high" threshold. |
| 3651 | */ |
| 3652 | if (sample->highest_usage >= threshold) { |
| 3653 | result = true; |
| 3654 | } |
| 3655 | } |
| 3656 | |
| 3657 | return result; |
| 3658 | } |
| 3659 | |
| 3660 | static |
| 3661 | bool evaluate_session_consumed_size_condition( |
| 3662 | const struct lttng_condition *condition, |
| 3663 | uint64_t session_consumed_size) |
| 3664 | { |
| 3665 | uint64_t threshold; |
| 3666 | const struct lttng_condition_session_consumed_size *size_condition = |
| 3667 | container_of(condition, |
| 3668 | struct lttng_condition_session_consumed_size, |
| 3669 | parent); |
| 3670 | |
| 3671 | threshold = size_condition->consumed_threshold_bytes.value; |
| 3672 | DBG("[notification-thread] Session consumed size condition being evaluated: threshold = %" PRIu64 ", current size = %" PRIu64, |
| 3673 | threshold, session_consumed_size); |
| 3674 | return session_consumed_size >= threshold; |
| 3675 | } |
| 3676 | |
| 3677 | static |
| 3678 | int evaluate_buffer_condition(const struct lttng_condition *condition, |
| 3679 | struct lttng_evaluation **evaluation, |
| 3680 | const struct notification_thread_state *state, |
| 3681 | const struct channel_state_sample *previous_sample, |
| 3682 | const struct channel_state_sample *latest_sample, |
| 3683 | uint64_t previous_session_consumed_total, |
| 3684 | uint64_t latest_session_consumed_total, |
| 3685 | struct channel_info *channel_info) |
| 3686 | { |
| 3687 | int ret = 0; |
| 3688 | enum lttng_condition_type condition_type; |
| 3689 | const bool previous_sample_available = !!previous_sample; |
| 3690 | bool previous_sample_result = false; |
| 3691 | bool latest_sample_result; |
| 3692 | |
| 3693 | condition_type = lttng_condition_get_type(condition); |
| 3694 | |
| 3695 | switch (condition_type) { |
| 3696 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 3697 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 3698 | if (caa_likely(previous_sample_available)) { |
| 3699 | previous_sample_result = |
| 3700 | evaluate_buffer_usage_condition(condition, |
| 3701 | previous_sample, channel_info->capacity); |
| 3702 | } |
| 3703 | latest_sample_result = evaluate_buffer_usage_condition( |
| 3704 | condition, latest_sample, |
| 3705 | channel_info->capacity); |
| 3706 | break; |
| 3707 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 3708 | if (caa_likely(previous_sample_available)) { |
| 3709 | previous_sample_result = |
| 3710 | evaluate_session_consumed_size_condition( |
| 3711 | condition, |
| 3712 | previous_session_consumed_total); |
| 3713 | } |
| 3714 | latest_sample_result = |
| 3715 | evaluate_session_consumed_size_condition( |
| 3716 | condition, |
| 3717 | latest_session_consumed_total); |
| 3718 | break; |
| 3719 | default: |
| 3720 | /* Unknown condition type; internal error. */ |
| 3721 | abort(); |
| 3722 | } |
| 3723 | |
| 3724 | if (!latest_sample_result || |
| 3725 | (previous_sample_result == latest_sample_result)) { |
| 3726 | /* |
| 3727 | * Only trigger on a condition evaluation transition. |
| 3728 | * |
| 3729 | * NOTE: This edge-triggered logic may not be appropriate for |
| 3730 | * future condition types. |
| 3731 | */ |
| 3732 | goto end; |
| 3733 | } |
| 3734 | |
| 3735 | if (!evaluation || !latest_sample_result) { |
| 3736 | goto end; |
| 3737 | } |
| 3738 | |
| 3739 | switch (condition_type) { |
| 3740 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 3741 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 3742 | *evaluation = lttng_evaluation_buffer_usage_create( |
| 3743 | condition_type, |
| 3744 | latest_sample->highest_usage, |
| 3745 | channel_info->capacity); |
| 3746 | break; |
| 3747 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 3748 | *evaluation = lttng_evaluation_session_consumed_size_create( |
| 3749 | latest_session_consumed_total); |
| 3750 | break; |
| 3751 | default: |
| 3752 | abort(); |
| 3753 | } |
| 3754 | |
| 3755 | if (!*evaluation) { |
| 3756 | ret = -1; |
| 3757 | goto end; |
| 3758 | } |
| 3759 | end: |
| 3760 | return ret; |
| 3761 | } |
| 3762 | |
| 3763 | static |
| 3764 | int client_notification_overflow(struct notification_client *client) |
| 3765 | { |
| 3766 | int ret = 0; |
| 3767 | const struct lttng_notification_channel_message msg = { |
| 3768 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED, |
| 3769 | }; |
| 3770 | |
| 3771 | ASSERT_LOCKED(client->lock); |
| 3772 | |
| 3773 | DBG("Dropping notification addressed to client (socket fd = %i)", |
| 3774 | client->socket); |
| 3775 | if (client->communication.outbound.dropped_notification) { |
| 3776 | /* |
| 3777 | * The client already has a "notification dropped" message |
| 3778 | * in its outgoing queue. Nothing to do since all |
| 3779 | * of those messages are coalesced. |
| 3780 | */ |
| 3781 | goto end; |
| 3782 | } |
| 3783 | |
| 3784 | client->communication.outbound.dropped_notification = true; |
| 3785 | ret = lttng_dynamic_buffer_append( |
| 3786 | &client->communication.outbound.payload.buffer, &msg, |
| 3787 | sizeof(msg)); |
| 3788 | if (ret) { |
| 3789 | PERROR("Failed to enqueue \"dropped notification\" message in client's (socket fd = %i) outgoing queue", |
| 3790 | client->socket); |
| 3791 | } |
| 3792 | end: |
| 3793 | return ret; |
| 3794 | } |
| 3795 | |
| 3796 | static int client_handle_transmission_status_wrapper( |
| 3797 | struct notification_client *client, |
| 3798 | enum client_transmission_status status, |
| 3799 | void *user_data) |
| 3800 | { |
| 3801 | return client_handle_transmission_status(client, status, |
| 3802 | (struct notification_thread_state *) user_data); |
| 3803 | } |
| 3804 | |
| 3805 | static |
| 3806 | int send_evaluation_to_clients(const struct lttng_trigger *trigger, |
| 3807 | const struct lttng_evaluation *evaluation, |
| 3808 | struct notification_client_list* client_list, |
| 3809 | struct notification_thread_state *state, |
| 3810 | uid_t object_uid, gid_t object_gid) |
| 3811 | { |
| 3812 | const struct lttng_credentials creds = { |
| 3813 | .uid = LTTNG_OPTIONAL_INIT_VALUE(object_uid), |
| 3814 | .gid = LTTNG_OPTIONAL_INIT_VALUE(object_gid), |
| 3815 | }; |
| 3816 | |
| 3817 | return notification_client_list_send_evaluation(client_list, |
| 3818 | lttng_trigger_get_const_condition(trigger), evaluation, |
| 3819 | lttng_trigger_get_credentials(trigger), |
| 3820 | &creds, |
| 3821 | client_handle_transmission_status_wrapper, state); |
| 3822 | } |
| 3823 | |
| 3824 | /* |
| 3825 | * Permission checks relative to notification channel clients are performed |
| 3826 | * here. Notice how object, client, and trigger credentials are involved in |
| 3827 | * this check. |
| 3828 | * |
| 3829 | * The `object` credentials are the credentials associated with the "subject" |
| 3830 | * of a condition. For instance, a `rotation completed` condition applies |
| 3831 | * to a session. When that condition is met, it will produce an evaluation |
| 3832 | * against a session. Hence, in this case, the `object` credentials are the |
| 3833 | * credentials of the "subject" session. |
| 3834 | * |
| 3835 | * The `trigger` credentials are the credentials of the user that registered the |
| 3836 | * trigger. |
| 3837 | * |
| 3838 | * The `client` credentials are the credentials of the user that created a given |
| 3839 | * notification channel. |
| 3840 | * |
| 3841 | * In terms of visibility, it is expected that non-privilieged users can only |
| 3842 | * register triggers against "their" objects (their own sessions and |
| 3843 | * applications they are allowed to interact with). They can then open a |
| 3844 | * notification channel and subscribe to notifications associated with those |
| 3845 | * triggers. |
| 3846 | * |
| 3847 | * As for privilieged users, they can register triggers against the objects of |
| 3848 | * other users. They can then subscribe to the notifications associated to their |
| 3849 | * triggers. Privilieged users _can't_ subscribe to the notifications of |
| 3850 | * triggers owned by other users; they must create their own triggers. |
| 3851 | * |
| 3852 | * This is more a concern of usability than security. It would be difficult for |
| 3853 | * a root user reliably subscribe to a specific set of conditions without |
| 3854 | * interference from external users (those could, for instance, unregister |
| 3855 | * their triggers). |
| 3856 | */ |
| 3857 | LTTNG_HIDDEN |
| 3858 | int notification_client_list_send_evaluation( |
| 3859 | struct notification_client_list *client_list, |
| 3860 | const struct lttng_condition *condition, |
| 3861 | const struct lttng_evaluation *evaluation, |
| 3862 | const struct lttng_credentials *trigger_creds, |
| 3863 | const struct lttng_credentials *source_object_creds, |
| 3864 | report_client_transmission_result_cb client_report, |
| 3865 | void *user_data) |
| 3866 | { |
| 3867 | int ret = 0; |
| 3868 | struct lttng_payload msg_payload; |
| 3869 | struct notification_client_list_element *client_list_element, *tmp; |
| 3870 | const struct lttng_notification notification = { |
| 3871 | .condition = (struct lttng_condition *) condition, |
| 3872 | .evaluation = (struct lttng_evaluation *) evaluation, |
| 3873 | }; |
| 3874 | struct lttng_notification_channel_message msg_header = { |
| 3875 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION, |
| 3876 | }; |
| 3877 | |
| 3878 | lttng_payload_init(&msg_payload); |
| 3879 | |
| 3880 | ret = lttng_dynamic_buffer_append(&msg_payload.buffer, &msg_header, |
| 3881 | sizeof(msg_header)); |
| 3882 | if (ret) { |
| 3883 | goto end; |
| 3884 | } |
| 3885 | |
| 3886 | ret = lttng_notification_serialize(¬ification, &msg_payload); |
| 3887 | if (ret) { |
| 3888 | ERR("[notification-thread] Failed to serialize notification"); |
| 3889 | ret = -1; |
| 3890 | goto end; |
| 3891 | } |
| 3892 | |
| 3893 | /* Update payload size. */ |
| 3894 | ((struct lttng_notification_channel_message *) msg_payload.buffer.data) |
| 3895 | ->size = (uint32_t)( |
| 3896 | msg_payload.buffer.size - sizeof(msg_header)); |
| 3897 | |
| 3898 | /* Update the payload number of fds. */ |
| 3899 | { |
| 3900 | const struct lttng_payload_view pv = lttng_payload_view_from_payload( |
| 3901 | &msg_payload, 0, -1); |
| 3902 | |
| 3903 | ((struct lttng_notification_channel_message *) |
| 3904 | msg_payload.buffer.data)->fds = (uint32_t) |
| 3905 | lttng_payload_view_get_fd_handle_count(&pv); |
| 3906 | } |
| 3907 | |
| 3908 | pthread_mutex_lock(&client_list->lock); |
| 3909 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 3910 | &client_list->list, node) { |
| 3911 | enum client_transmission_status transmission_status; |
| 3912 | struct notification_client *client = |
| 3913 | client_list_element->client; |
| 3914 | |
| 3915 | ret = 0; |
| 3916 | pthread_mutex_lock(&client->lock); |
| 3917 | if (!client->communication.active) { |
| 3918 | /* |
| 3919 | * Skip inactive client (protocol error or |
| 3920 | * disconnecting). |
| 3921 | */ |
| 3922 | DBG("Skipping client at it is marked as inactive"); |
| 3923 | goto skip_client; |
| 3924 | } |
| 3925 | |
| 3926 | if (source_object_creds) { |
| 3927 | if (client->uid != lttng_credentials_get_uid(source_object_creds) && |
| 3928 | client->gid != lttng_credentials_get_gid(source_object_creds) && |
| 3929 | client->uid != 0) { |
| 3930 | /* |
| 3931 | * Client is not allowed to monitor this |
| 3932 | * object. |
| 3933 | */ |
| 3934 | DBG("[notification-thread] Skipping client at it does not have the object permission to receive notification for this trigger"); |
| 3935 | goto skip_client; |
| 3936 | } |
| 3937 | } |
| 3938 | |
| 3939 | if (client->uid != lttng_credentials_get_uid(trigger_creds) && client->gid != lttng_credentials_get_gid(trigger_creds)) { |
| 3940 | DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger"); |
| 3941 | goto skip_client; |
| 3942 | } |
| 3943 | |
| 3944 | DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", |
| 3945 | client->socket, msg_payload.buffer.size); |
| 3946 | |
| 3947 | if (client_has_outbound_data_left(client)) { |
| 3948 | /* |
| 3949 | * Outgoing data is already buffered for this client; |
| 3950 | * drop the notification and enqueue a "dropped |
| 3951 | * notification" message if this is the first dropped |
| 3952 | * notification since the socket spilled-over to the |
| 3953 | * queue. |
| 3954 | */ |
| 3955 | ret = client_notification_overflow(client); |
| 3956 | if (ret) { |
| 3957 | /* Fatal error. */ |
| 3958 | goto skip_client; |
| 3959 | } |
| 3960 | } |
| 3961 | |
| 3962 | ret = lttng_payload_copy(&msg_payload, &client->communication.outbound.payload); |
| 3963 | if (ret) { |
| 3964 | /* Fatal error. */ |
| 3965 | goto skip_client; |
| 3966 | } |
| 3967 | |
| 3968 | transmission_status = client_flush_outgoing_queue(client); |
| 3969 | pthread_mutex_unlock(&client->lock); |
| 3970 | ret = client_report(client, transmission_status, user_data); |
| 3971 | if (ret) { |
| 3972 | /* Fatal error. */ |
| 3973 | goto end_unlock_list; |
| 3974 | } |
| 3975 | |
| 3976 | continue; |
| 3977 | |
| 3978 | skip_client: |
| 3979 | pthread_mutex_unlock(&client->lock); |
| 3980 | if (ret) { |
| 3981 | /* Fatal error. */ |
| 3982 | goto end_unlock_list; |
| 3983 | } |
| 3984 | } |
| 3985 | ret = 0; |
| 3986 | |
| 3987 | end_unlock_list: |
| 3988 | pthread_mutex_unlock(&client_list->lock); |
| 3989 | end: |
| 3990 | lttng_payload_reset(&msg_payload); |
| 3991 | return ret; |
| 3992 | } |
| 3993 | |
| 3994 | int handle_notification_thread_channel_sample( |
| 3995 | struct notification_thread_state *state, int pipe, |
| 3996 | enum lttng_domain_type domain) |
| 3997 | { |
| 3998 | int ret = 0; |
| 3999 | struct lttcomm_consumer_channel_monitor_msg sample_msg; |
| 4000 | struct channel_info *channel_info; |
| 4001 | struct cds_lfht_node *node; |
| 4002 | struct cds_lfht_iter iter; |
| 4003 | struct lttng_channel_trigger_list *trigger_list; |
| 4004 | struct lttng_trigger_list_element *trigger_list_element; |
| 4005 | bool previous_sample_available = false; |
| 4006 | struct channel_state_sample previous_sample, latest_sample; |
| 4007 | uint64_t previous_session_consumed_total, latest_session_consumed_total; |
| 4008 | struct lttng_credentials channel_creds; |
| 4009 | |
| 4010 | /* |
| 4011 | * The monitoring pipe only holds messages smaller than PIPE_BUF, |
| 4012 | * ensuring that read/write of sampling messages are atomic. |
| 4013 | */ |
| 4014 | ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg)); |
| 4015 | if (ret != sizeof(sample_msg)) { |
| 4016 | ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)", |
| 4017 | pipe); |
| 4018 | ret = -1; |
| 4019 | goto end; |
| 4020 | } |
| 4021 | |
| 4022 | ret = 0; |
| 4023 | latest_sample.key.key = sample_msg.key; |
| 4024 | latest_sample.key.domain = domain; |
| 4025 | latest_sample.highest_usage = sample_msg.highest; |
| 4026 | latest_sample.lowest_usage = sample_msg.lowest; |
| 4027 | latest_sample.channel_total_consumed = sample_msg.total_consumed; |
| 4028 | |
| 4029 | rcu_read_lock(); |
| 4030 | |
| 4031 | /* Retrieve the channel's informations */ |
| 4032 | cds_lfht_lookup(state->channels_ht, |
| 4033 | hash_channel_key(&latest_sample.key), |
| 4034 | match_channel_info, |
| 4035 | &latest_sample.key, |
| 4036 | &iter); |
| 4037 | node = cds_lfht_iter_get_node(&iter); |
| 4038 | if (caa_unlikely(!node)) { |
| 4039 | /* |
| 4040 | * Not an error since the consumer can push a sample to the pipe |
| 4041 | * and the rest of the session daemon could notify us of the |
| 4042 | * channel's destruction before we get a chance to process that |
| 4043 | * sample. |
| 4044 | */ |
| 4045 | DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", |
| 4046 | latest_sample.key.key, |
| 4047 | domain == LTTNG_DOMAIN_KERNEL ? "kernel" : |
| 4048 | "user space"); |
| 4049 | goto end_unlock; |
| 4050 | } |
| 4051 | channel_info = caa_container_of(node, struct channel_info, |
| 4052 | channels_ht_node); |
| 4053 | DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64", total consumed = %" PRIu64")", |
| 4054 | channel_info->name, |
| 4055 | latest_sample.key.key, |
| 4056 | channel_info->session_info->name, |
| 4057 | latest_sample.highest_usage, |
| 4058 | latest_sample.lowest_usage, |
| 4059 | latest_sample.channel_total_consumed); |
| 4060 | |
| 4061 | previous_session_consumed_total = |
| 4062 | channel_info->session_info->consumed_data_size; |
| 4063 | |
| 4064 | /* Retrieve the channel's last sample, if it exists, and update it. */ |
| 4065 | cds_lfht_lookup(state->channel_state_ht, |
| 4066 | hash_channel_key(&latest_sample.key), |
| 4067 | match_channel_state_sample, |
| 4068 | &latest_sample.key, |
| 4069 | &iter); |
| 4070 | node = cds_lfht_iter_get_node(&iter); |
| 4071 | if (caa_likely(node)) { |
| 4072 | struct channel_state_sample *stored_sample; |
| 4073 | |
| 4074 | /* Update the sample stored. */ |
| 4075 | stored_sample = caa_container_of(node, |
| 4076 | struct channel_state_sample, |
| 4077 | channel_state_ht_node); |
| 4078 | |
| 4079 | memcpy(&previous_sample, stored_sample, |
| 4080 | sizeof(previous_sample)); |
| 4081 | stored_sample->highest_usage = latest_sample.highest_usage; |
| 4082 | stored_sample->lowest_usage = latest_sample.lowest_usage; |
| 4083 | stored_sample->channel_total_consumed = latest_sample.channel_total_consumed; |
| 4084 | previous_sample_available = true; |
| 4085 | |
| 4086 | latest_session_consumed_total = |
| 4087 | previous_session_consumed_total + |
| 4088 | (latest_sample.channel_total_consumed - previous_sample.channel_total_consumed); |
| 4089 | } else { |
| 4090 | /* |
| 4091 | * This is the channel's first sample, allocate space for and |
| 4092 | * store the new sample. |
| 4093 | */ |
| 4094 | struct channel_state_sample *stored_sample; |
| 4095 | |
| 4096 | stored_sample = zmalloc(sizeof(*stored_sample)); |
| 4097 | if (!stored_sample) { |
| 4098 | ret = -1; |
| 4099 | goto end_unlock; |
| 4100 | } |
| 4101 | |
| 4102 | memcpy(stored_sample, &latest_sample, sizeof(*stored_sample)); |
| 4103 | cds_lfht_node_init(&stored_sample->channel_state_ht_node); |
| 4104 | cds_lfht_add(state->channel_state_ht, |
| 4105 | hash_channel_key(&stored_sample->key), |
| 4106 | &stored_sample->channel_state_ht_node); |
| 4107 | |
| 4108 | latest_session_consumed_total = |
| 4109 | previous_session_consumed_total + |
| 4110 | latest_sample.channel_total_consumed; |
| 4111 | } |
| 4112 | |
| 4113 | channel_info->session_info->consumed_data_size = |
| 4114 | latest_session_consumed_total; |
| 4115 | |
| 4116 | /* Find triggers associated with this channel. */ |
| 4117 | cds_lfht_lookup(state->channel_triggers_ht, |
| 4118 | hash_channel_key(&latest_sample.key), |
| 4119 | match_channel_trigger_list, |
| 4120 | &latest_sample.key, |
| 4121 | &iter); |
| 4122 | node = cds_lfht_iter_get_node(&iter); |
| 4123 | if (caa_likely(!node)) { |
| 4124 | goto end_unlock; |
| 4125 | } |
| 4126 | |
| 4127 | channel_creds = (typeof(channel_creds)) { |
| 4128 | .uid = LTTNG_OPTIONAL_INIT_VALUE(channel_info->session_info->uid), |
| 4129 | .gid = LTTNG_OPTIONAL_INIT_VALUE(channel_info->session_info->gid), |
| 4130 | }; |
| 4131 | |
| 4132 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 4133 | channel_triggers_ht_node); |
| 4134 | cds_list_for_each_entry(trigger_list_element, &trigger_list->list, |
| 4135 | node) { |
| 4136 | const struct lttng_condition *condition; |
| 4137 | struct lttng_trigger *trigger; |
| 4138 | struct notification_client_list *client_list = NULL; |
| 4139 | struct lttng_evaluation *evaluation = NULL; |
| 4140 | enum action_executor_status executor_status; |
| 4141 | |
| 4142 | ret = 0; |
| 4143 | trigger = trigger_list_element->trigger; |
| 4144 | condition = lttng_trigger_get_const_condition(trigger); |
| 4145 | assert(condition); |
| 4146 | |
| 4147 | /* |
| 4148 | * Check if any client is subscribed to the result of this |
| 4149 | * evaluation. |
| 4150 | */ |
| 4151 | client_list = get_client_list_from_condition(state, condition); |
| 4152 | |
| 4153 | ret = evaluate_buffer_condition(condition, &evaluation, state, |
| 4154 | previous_sample_available ? &previous_sample : NULL, |
| 4155 | &latest_sample, |
| 4156 | previous_session_consumed_total, |
| 4157 | latest_session_consumed_total, |
| 4158 | channel_info); |
| 4159 | if (caa_unlikely(ret)) { |
| 4160 | goto put_list; |
| 4161 | } |
| 4162 | |
| 4163 | if (caa_likely(!evaluation)) { |
| 4164 | goto put_list; |
| 4165 | } |
| 4166 | |
| 4167 | if (!lttng_trigger_should_fire(trigger)) { |
| 4168 | goto put_list; |
| 4169 | } |
| 4170 | |
| 4171 | lttng_trigger_fire(trigger); |
| 4172 | |
| 4173 | /* |
| 4174 | * Ownership of `evaluation` transferred to the action executor |
| 4175 | * no matter the result. |
| 4176 | */ |
| 4177 | executor_status = action_executor_enqueue(state->executor, |
| 4178 | trigger, evaluation, &channel_creds, |
| 4179 | client_list); |
| 4180 | evaluation = NULL; |
| 4181 | switch (executor_status) { |
| 4182 | case ACTION_EXECUTOR_STATUS_OK: |
| 4183 | break; |
| 4184 | case ACTION_EXECUTOR_STATUS_ERROR: |
| 4185 | case ACTION_EXECUTOR_STATUS_INVALID: |
| 4186 | /* |
| 4187 | * TODO Add trigger identification (name/id) when |
| 4188 | * it is added to the API. |
| 4189 | */ |
| 4190 | ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger"); |
| 4191 | ret = -1; |
| 4192 | goto put_list; |
| 4193 | case ACTION_EXECUTOR_STATUS_OVERFLOW: |
| 4194 | /* |
| 4195 | * TODO Add trigger identification (name/id) when |
| 4196 | * it is added to the API. |
| 4197 | * |
| 4198 | * Not a fatal error. |
| 4199 | */ |
| 4200 | WARN("No space left when enqueuing action associated with buffer-condition trigger"); |
| 4201 | ret = 0; |
| 4202 | goto put_list; |
| 4203 | default: |
| 4204 | abort(); |
| 4205 | } |
| 4206 | |
| 4207 | put_list: |
| 4208 | notification_client_list_put(client_list); |
| 4209 | if (caa_unlikely(ret)) { |
| 4210 | break; |
| 4211 | } |
| 4212 | } |
| 4213 | end_unlock: |
| 4214 | rcu_read_unlock(); |
| 4215 | end: |
| 4216 | return ret; |
| 4217 | } |