| 1 | /* |
| 2 | * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License, version 2 only, as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 11 | * more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along with |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #define _LGPL_SOURCE |
| 19 | #include <urcu.h> |
| 20 | #include <urcu/rculfhash.h> |
| 21 | |
| 22 | #include <common/defaults.h> |
| 23 | #include <common/error.h> |
| 24 | #include <common/futex.h> |
| 25 | #include <common/unix.h> |
| 26 | #include <common/dynamic-buffer.h> |
| 27 | #include <common/hashtable/utils.h> |
| 28 | #include <common/sessiond-comm/sessiond-comm.h> |
| 29 | #include <common/macros.h> |
| 30 | #include <lttng/condition/condition.h> |
| 31 | #include <lttng/action/action-internal.h> |
| 32 | #include <lttng/notification/notification-internal.h> |
| 33 | #include <lttng/condition/condition-internal.h> |
| 34 | #include <lttng/condition/buffer-usage-internal.h> |
| 35 | #include <lttng/condition/session-consumed-size-internal.h> |
| 36 | #include <lttng/condition/session-rotation-internal.h> |
| 37 | #include <lttng/notification/channel-internal.h> |
| 38 | |
| 39 | #include <time.h> |
| 40 | #include <unistd.h> |
| 41 | #include <assert.h> |
| 42 | #include <inttypes.h> |
| 43 | #include <fcntl.h> |
| 44 | |
| 45 | #include "notification-thread.h" |
| 46 | #include "notification-thread-events.h" |
| 47 | #include "notification-thread-commands.h" |
| 48 | #include "lttng-sessiond.h" |
| 49 | #include "kernel.h" |
| 50 | |
| 51 | #define CLIENT_POLL_MASK_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP) |
| 52 | #define CLIENT_POLL_MASK_IN_OUT (CLIENT_POLL_MASK_IN | LPOLLOUT) |
| 53 | |
| 54 | enum lttng_object_type { |
| 55 | LTTNG_OBJECT_TYPE_UNKNOWN, |
| 56 | LTTNG_OBJECT_TYPE_NONE, |
| 57 | LTTNG_OBJECT_TYPE_CHANNEL, |
| 58 | LTTNG_OBJECT_TYPE_SESSION, |
| 59 | }; |
| 60 | |
| 61 | struct lttng_trigger_list_element { |
| 62 | /* No ownership of the trigger object is assumed. */ |
| 63 | const struct lttng_trigger *trigger; |
| 64 | struct cds_list_head node; |
| 65 | }; |
| 66 | |
| 67 | struct lttng_channel_trigger_list { |
| 68 | struct channel_key channel_key; |
| 69 | /* List of struct lttng_trigger_list_element. */ |
| 70 | struct cds_list_head list; |
| 71 | /* Node in the channel_triggers_ht */ |
| 72 | struct cds_lfht_node channel_triggers_ht_node; |
| 73 | }; |
| 74 | |
| 75 | /* |
| 76 | * List of triggers applying to a given session. |
| 77 | * |
| 78 | * See: |
| 79 | * - lttng_session_trigger_list_create() |
| 80 | * - lttng_session_trigger_list_build() |
| 81 | * - lttng_session_trigger_list_destroy() |
| 82 | * - lttng_session_trigger_list_add() |
| 83 | */ |
| 84 | struct lttng_session_trigger_list { |
| 85 | /* |
| 86 | * Not owned by this; points to the session_info structure's |
| 87 | * session name. |
| 88 | */ |
| 89 | const char *session_name; |
| 90 | /* List of struct lttng_trigger_list_element. */ |
| 91 | struct cds_list_head list; |
| 92 | /* Node in the session_triggers_ht */ |
| 93 | struct cds_lfht_node session_triggers_ht_node; |
| 94 | /* |
| 95 | * Weak reference to the notification system's session triggers |
| 96 | * hashtable. |
| 97 | * |
| 98 | * The session trigger list structure structure is owned by |
| 99 | * the session's session_info. |
| 100 | * |
| 101 | * The session_info is kept alive the the channel_infos holding a |
| 102 | * reference to it (reference counting). When those channels are |
| 103 | * destroyed (at runtime or on teardown), the reference they hold |
| 104 | * to the session_info are released. On destruction of session_info, |
| 105 | * session_info_destroy() will remove the list of triggers applying |
| 106 | * to this session from the notification system's state. |
| 107 | * |
| 108 | * This implies that the session_triggers_ht must be destroyed |
| 109 | * after the channels. |
| 110 | */ |
| 111 | struct cds_lfht *session_triggers_ht; |
| 112 | /* Used for delayed RCU reclaim. */ |
| 113 | struct rcu_head rcu_node; |
| 114 | }; |
| 115 | |
| 116 | struct lttng_trigger_ht_element { |
| 117 | struct lttng_trigger *trigger; |
| 118 | struct cds_lfht_node node; |
| 119 | }; |
| 120 | |
| 121 | struct lttng_condition_list_element { |
| 122 | struct lttng_condition *condition; |
| 123 | struct cds_list_head node; |
| 124 | }; |
| 125 | |
| 126 | struct notification_client_list_element { |
| 127 | struct notification_client *client; |
| 128 | struct cds_list_head node; |
| 129 | }; |
| 130 | |
| 131 | struct notification_client_list { |
| 132 | struct lttng_trigger *trigger; |
| 133 | struct cds_list_head list; |
| 134 | struct cds_lfht_node notification_trigger_ht_node; |
| 135 | }; |
| 136 | |
| 137 | struct notification_client { |
| 138 | int socket; |
| 139 | /* Client protocol version. */ |
| 140 | uint8_t major, minor; |
| 141 | uid_t uid; |
| 142 | gid_t gid; |
| 143 | /* |
| 144 | * Indicates if the credentials and versions of the client have been |
| 145 | * checked. |
| 146 | */ |
| 147 | bool validated; |
| 148 | /* |
| 149 | * Conditions to which the client's notification channel is subscribed. |
| 150 | * List of struct lttng_condition_list_node. The condition member is |
| 151 | * owned by the client. |
| 152 | */ |
| 153 | struct cds_list_head condition_list; |
| 154 | struct cds_lfht_node client_socket_ht_node; |
| 155 | struct { |
| 156 | struct { |
| 157 | /* |
| 158 | * During the reception of a message, the reception |
| 159 | * buffers' "size" is set to contain the current |
| 160 | * message's complete payload. |
| 161 | */ |
| 162 | struct lttng_dynamic_buffer buffer; |
| 163 | /* Bytes left to receive for the current message. */ |
| 164 | size_t bytes_to_receive; |
| 165 | /* Type of the message being received. */ |
| 166 | enum lttng_notification_channel_message_type msg_type; |
| 167 | /* |
| 168 | * Indicates whether or not credentials are expected |
| 169 | * from the client. |
| 170 | */ |
| 171 | bool expect_creds; |
| 172 | /* |
| 173 | * Indicates whether or not credentials were received |
| 174 | * from the client. |
| 175 | */ |
| 176 | bool creds_received; |
| 177 | /* Only used during credentials reception. */ |
| 178 | lttng_sock_cred creds; |
| 179 | } inbound; |
| 180 | struct { |
| 181 | /* |
| 182 | * Indicates whether or not a notification addressed to |
| 183 | * this client was dropped because a command reply was |
| 184 | * already buffered. |
| 185 | * |
| 186 | * A notification is dropped whenever the buffer is not |
| 187 | * empty. |
| 188 | */ |
| 189 | bool dropped_notification; |
| 190 | /* |
| 191 | * Indicates whether or not a command reply is already |
| 192 | * buffered. In this case, it means that the client is |
| 193 | * not consuming command replies before emitting a new |
| 194 | * one. This could be caused by a protocol error or a |
| 195 | * misbehaving/malicious client. |
| 196 | */ |
| 197 | bool queued_command_reply; |
| 198 | struct lttng_dynamic_buffer buffer; |
| 199 | } outbound; |
| 200 | } communication; |
| 201 | }; |
| 202 | |
| 203 | struct channel_state_sample { |
| 204 | struct channel_key key; |
| 205 | struct cds_lfht_node channel_state_ht_node; |
| 206 | uint64_t highest_usage; |
| 207 | uint64_t lowest_usage; |
| 208 | uint64_t channel_total_consumed; |
| 209 | }; |
| 210 | |
| 211 | static unsigned long hash_channel_key(struct channel_key *key); |
| 212 | static int evaluate_condition(const struct lttng_condition *condition, |
| 213 | struct lttng_evaluation **evaluation, |
| 214 | const struct notification_thread_state *state, |
| 215 | const struct channel_state_sample *previous_sample, |
| 216 | const struct channel_state_sample *latest_sample, |
| 217 | uint64_t previous_session_consumed_total, |
| 218 | uint64_t latest_session_consumed_total, |
| 219 | struct channel_info *channel_info); |
| 220 | static |
| 221 | int send_evaluation_to_clients(const struct lttng_trigger *trigger, |
| 222 | const struct lttng_evaluation *evaluation, |
| 223 | struct notification_client_list *client_list, |
| 224 | struct notification_thread_state *state, |
| 225 | uid_t channel_uid, gid_t channel_gid); |
| 226 | |
| 227 | |
| 228 | /* session_info API */ |
| 229 | static |
| 230 | void session_info_destroy(void *_data); |
| 231 | static |
| 232 | void session_info_get(struct session_info *session_info); |
| 233 | static |
| 234 | void session_info_put(struct session_info *session_info); |
| 235 | static |
| 236 | struct session_info *session_info_create(const char *name, |
| 237 | uid_t uid, gid_t gid, |
| 238 | struct lttng_session_trigger_list *trigger_list, |
| 239 | struct cds_lfht *sessions_ht); |
| 240 | static |
| 241 | void session_info_add_channel(struct session_info *session_info, |
| 242 | struct channel_info *channel_info); |
| 243 | static |
| 244 | void session_info_remove_channel(struct session_info *session_info, |
| 245 | struct channel_info *channel_info); |
| 246 | |
| 247 | /* lttng_session_trigger_list API */ |
| 248 | static |
| 249 | struct lttng_session_trigger_list *lttng_session_trigger_list_create( |
| 250 | const char *session_name, |
| 251 | struct cds_lfht *session_triggers_ht); |
| 252 | static |
| 253 | struct lttng_session_trigger_list *lttng_session_trigger_list_build( |
| 254 | const struct notification_thread_state *state, |
| 255 | const char *session_name); |
| 256 | static |
| 257 | void lttng_session_trigger_list_destroy( |
| 258 | struct lttng_session_trigger_list *list); |
| 259 | static |
| 260 | int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list, |
| 261 | const struct lttng_trigger *trigger); |
| 262 | |
| 263 | |
| 264 | static |
| 265 | int match_client(struct cds_lfht_node *node, const void *key) |
| 266 | { |
| 267 | /* This double-cast is intended to supress pointer-to-cast warning. */ |
| 268 | int socket = (int) (intptr_t) key; |
| 269 | struct notification_client *client; |
| 270 | |
| 271 | client = caa_container_of(node, struct notification_client, |
| 272 | client_socket_ht_node); |
| 273 | |
| 274 | return !!(client->socket == socket); |
| 275 | } |
| 276 | |
| 277 | static |
| 278 | int match_channel_trigger_list(struct cds_lfht_node *node, const void *key) |
| 279 | { |
| 280 | struct channel_key *channel_key = (struct channel_key *) key; |
| 281 | struct lttng_channel_trigger_list *trigger_list; |
| 282 | |
| 283 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 284 | channel_triggers_ht_node); |
| 285 | |
| 286 | return !!((channel_key->key == trigger_list->channel_key.key) && |
| 287 | (channel_key->domain == trigger_list->channel_key.domain)); |
| 288 | } |
| 289 | |
| 290 | static |
| 291 | int match_session_trigger_list(struct cds_lfht_node *node, const void *key) |
| 292 | { |
| 293 | const char *session_name = (const char *) key; |
| 294 | struct lttng_session_trigger_list *trigger_list; |
| 295 | |
| 296 | trigger_list = caa_container_of(node, struct lttng_session_trigger_list, |
| 297 | session_triggers_ht_node); |
| 298 | |
| 299 | return !!(strcmp(trigger_list->session_name, session_name) == 0); |
| 300 | } |
| 301 | |
| 302 | static |
| 303 | int match_channel_state_sample(struct cds_lfht_node *node, const void *key) |
| 304 | { |
| 305 | struct channel_key *channel_key = (struct channel_key *) key; |
| 306 | struct channel_state_sample *sample; |
| 307 | |
| 308 | sample = caa_container_of(node, struct channel_state_sample, |
| 309 | channel_state_ht_node); |
| 310 | |
| 311 | return !!((channel_key->key == sample->key.key) && |
| 312 | (channel_key->domain == sample->key.domain)); |
| 313 | } |
| 314 | |
| 315 | static |
| 316 | int match_channel_info(struct cds_lfht_node *node, const void *key) |
| 317 | { |
| 318 | struct channel_key *channel_key = (struct channel_key *) key; |
| 319 | struct channel_info *channel_info; |
| 320 | |
| 321 | channel_info = caa_container_of(node, struct channel_info, |
| 322 | channels_ht_node); |
| 323 | |
| 324 | return !!((channel_key->key == channel_info->key.key) && |
| 325 | (channel_key->domain == channel_info->key.domain)); |
| 326 | } |
| 327 | |
| 328 | static |
| 329 | int match_condition(struct cds_lfht_node *node, const void *key) |
| 330 | { |
| 331 | struct lttng_condition *condition_key = (struct lttng_condition *) key; |
| 332 | struct lttng_trigger_ht_element *trigger; |
| 333 | struct lttng_condition *condition; |
| 334 | |
| 335 | trigger = caa_container_of(node, struct lttng_trigger_ht_element, |
| 336 | node); |
| 337 | condition = lttng_trigger_get_condition(trigger->trigger); |
| 338 | assert(condition); |
| 339 | |
| 340 | return !!lttng_condition_is_equal(condition_key, condition); |
| 341 | } |
| 342 | |
| 343 | static |
| 344 | int match_client_list(struct cds_lfht_node *node, const void *key) |
| 345 | { |
| 346 | struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; |
| 347 | struct notification_client_list *client_list; |
| 348 | struct lttng_condition *condition; |
| 349 | struct lttng_condition *condition_key = lttng_trigger_get_condition( |
| 350 | trigger_key); |
| 351 | |
| 352 | assert(condition_key); |
| 353 | |
| 354 | client_list = caa_container_of(node, struct notification_client_list, |
| 355 | notification_trigger_ht_node); |
| 356 | condition = lttng_trigger_get_condition(client_list->trigger); |
| 357 | |
| 358 | return !!lttng_condition_is_equal(condition_key, condition); |
| 359 | } |
| 360 | |
| 361 | static |
| 362 | int match_client_list_condition(struct cds_lfht_node *node, const void *key) |
| 363 | { |
| 364 | struct lttng_condition *condition_key = (struct lttng_condition *) key; |
| 365 | struct notification_client_list *client_list; |
| 366 | struct lttng_condition *condition; |
| 367 | |
| 368 | assert(condition_key); |
| 369 | |
| 370 | client_list = caa_container_of(node, struct notification_client_list, |
| 371 | notification_trigger_ht_node); |
| 372 | condition = lttng_trigger_get_condition(client_list->trigger); |
| 373 | |
| 374 | return !!lttng_condition_is_equal(condition_key, condition); |
| 375 | } |
| 376 | |
| 377 | static |
| 378 | unsigned long lttng_condition_buffer_usage_hash( |
| 379 | const struct lttng_condition *_condition) |
| 380 | { |
| 381 | unsigned long hash; |
| 382 | unsigned long condition_type; |
| 383 | struct lttng_condition_buffer_usage *condition; |
| 384 | |
| 385 | condition = container_of(_condition, |
| 386 | struct lttng_condition_buffer_usage, parent); |
| 387 | |
| 388 | condition_type = (unsigned long) condition->parent.type; |
| 389 | hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); |
| 390 | if (condition->session_name) { |
| 391 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); |
| 392 | } |
| 393 | if (condition->channel_name) { |
| 394 | hash ^= hash_key_str(condition->channel_name, lttng_ht_seed); |
| 395 | } |
| 396 | if (condition->domain.set) { |
| 397 | hash ^= hash_key_ulong( |
| 398 | (void *) condition->domain.type, |
| 399 | lttng_ht_seed); |
| 400 | } |
| 401 | if (condition->threshold_ratio.set) { |
| 402 | uint64_t val; |
| 403 | |
| 404 | val = condition->threshold_ratio.value * (double) UINT32_MAX; |
| 405 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 406 | } else if (condition->threshold_bytes.set) { |
| 407 | uint64_t val; |
| 408 | |
| 409 | val = condition->threshold_bytes.value; |
| 410 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 411 | } |
| 412 | return hash; |
| 413 | } |
| 414 | |
| 415 | static |
| 416 | unsigned long lttng_condition_session_consumed_size_hash( |
| 417 | const struct lttng_condition *_condition) |
| 418 | { |
| 419 | unsigned long hash; |
| 420 | unsigned long condition_type = |
| 421 | (unsigned long) LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE; |
| 422 | struct lttng_condition_session_consumed_size *condition; |
| 423 | uint64_t val; |
| 424 | |
| 425 | condition = container_of(_condition, |
| 426 | struct lttng_condition_session_consumed_size, parent); |
| 427 | |
| 428 | hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); |
| 429 | if (condition->session_name) { |
| 430 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); |
| 431 | } |
| 432 | val = condition->consumed_threshold_bytes.value; |
| 433 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 434 | return hash; |
| 435 | } |
| 436 | |
| 437 | static |
| 438 | unsigned long lttng_condition_session_rotation_hash( |
| 439 | const struct lttng_condition *_condition) |
| 440 | { |
| 441 | unsigned long hash, condition_type; |
| 442 | struct lttng_condition_session_rotation *condition; |
| 443 | |
| 444 | condition = container_of(_condition, |
| 445 | struct lttng_condition_session_rotation, parent); |
| 446 | condition_type = (unsigned long) condition->parent.type; |
| 447 | hash = hash_key_ulong((void *) condition_type, lttng_ht_seed); |
| 448 | assert(condition->session_name); |
| 449 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); |
| 450 | return hash; |
| 451 | } |
| 452 | |
| 453 | /* |
| 454 | * The lttng_condition hashing code is kept in this file (rather than |
| 455 | * condition.c) since it makes use of GPLv2 code (hashtable utils), which we |
| 456 | * don't want to link in liblttng-ctl. |
| 457 | */ |
| 458 | static |
| 459 | unsigned long lttng_condition_hash(const struct lttng_condition *condition) |
| 460 | { |
| 461 | switch (condition->type) { |
| 462 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 463 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 464 | return lttng_condition_buffer_usage_hash(condition); |
| 465 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 466 | return lttng_condition_session_consumed_size_hash(condition); |
| 467 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 468 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 469 | return lttng_condition_session_rotation_hash(condition); |
| 470 | default: |
| 471 | ERR("[notification-thread] Unexpected condition type caught"); |
| 472 | abort(); |
| 473 | } |
| 474 | } |
| 475 | |
| 476 | static |
| 477 | unsigned long hash_channel_key(struct channel_key *key) |
| 478 | { |
| 479 | unsigned long key_hash = hash_key_u64(&key->key, lttng_ht_seed); |
| 480 | unsigned long domain_hash = hash_key_ulong( |
| 481 | (void *) (unsigned long) key->domain, lttng_ht_seed); |
| 482 | |
| 483 | return key_hash ^ domain_hash; |
| 484 | } |
| 485 | |
| 486 | static |
| 487 | void channel_info_destroy(struct channel_info *channel_info) |
| 488 | { |
| 489 | if (!channel_info) { |
| 490 | return; |
| 491 | } |
| 492 | |
| 493 | if (channel_info->session_info) { |
| 494 | session_info_remove_channel(channel_info->session_info, |
| 495 | channel_info); |
| 496 | session_info_put(channel_info->session_info); |
| 497 | } |
| 498 | if (channel_info->name) { |
| 499 | free(channel_info->name); |
| 500 | } |
| 501 | free(channel_info); |
| 502 | } |
| 503 | |
| 504 | /* Don't call directly, use the ref-counting mechanism. */ |
| 505 | static |
| 506 | void session_info_destroy(void *_data) |
| 507 | { |
| 508 | struct session_info *session_info = _data; |
| 509 | int ret; |
| 510 | |
| 511 | assert(session_info); |
| 512 | if (session_info->channel_infos_ht) { |
| 513 | ret = cds_lfht_destroy(session_info->channel_infos_ht, NULL); |
| 514 | if (ret) { |
| 515 | ERR("[notification-thread] Failed to destroy channel information hash table"); |
| 516 | } |
| 517 | } |
| 518 | lttng_session_trigger_list_destroy(session_info->trigger_list); |
| 519 | |
| 520 | rcu_read_lock(); |
| 521 | cds_lfht_del(session_info->sessions_ht, |
| 522 | &session_info->sessions_ht_node); |
| 523 | rcu_read_unlock(); |
| 524 | free(session_info->name); |
| 525 | free(session_info); |
| 526 | } |
| 527 | |
| 528 | static |
| 529 | void session_info_get(struct session_info *session_info) |
| 530 | { |
| 531 | if (!session_info) { |
| 532 | return; |
| 533 | } |
| 534 | lttng_ref_get(&session_info->ref); |
| 535 | } |
| 536 | |
| 537 | static |
| 538 | void session_info_put(struct session_info *session_info) |
| 539 | { |
| 540 | if (!session_info) { |
| 541 | return; |
| 542 | } |
| 543 | lttng_ref_put(&session_info->ref); |
| 544 | } |
| 545 | |
| 546 | static |
| 547 | struct session_info *session_info_create(const char *name, uid_t uid, gid_t gid, |
| 548 | struct lttng_session_trigger_list *trigger_list, |
| 549 | struct cds_lfht *sessions_ht) |
| 550 | { |
| 551 | struct session_info *session_info; |
| 552 | |
| 553 | assert(name); |
| 554 | |
| 555 | session_info = zmalloc(sizeof(*session_info)); |
| 556 | if (!session_info) { |
| 557 | goto end; |
| 558 | } |
| 559 | lttng_ref_init(&session_info->ref, session_info_destroy); |
| 560 | |
| 561 | session_info->channel_infos_ht = cds_lfht_new(DEFAULT_HT_SIZE, |
| 562 | 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 563 | if (!session_info->channel_infos_ht) { |
| 564 | goto error; |
| 565 | } |
| 566 | |
| 567 | cds_lfht_node_init(&session_info->sessions_ht_node); |
| 568 | session_info->name = strdup(name); |
| 569 | if (!session_info->name) { |
| 570 | goto error; |
| 571 | } |
| 572 | session_info->uid = uid; |
| 573 | session_info->gid = gid; |
| 574 | session_info->trigger_list = trigger_list; |
| 575 | session_info->sessions_ht = sessions_ht; |
| 576 | end: |
| 577 | return session_info; |
| 578 | error: |
| 579 | session_info_put(session_info); |
| 580 | return NULL; |
| 581 | } |
| 582 | |
| 583 | static |
| 584 | void session_info_add_channel(struct session_info *session_info, |
| 585 | struct channel_info *channel_info) |
| 586 | { |
| 587 | rcu_read_lock(); |
| 588 | cds_lfht_add(session_info->channel_infos_ht, |
| 589 | hash_channel_key(&channel_info->key), |
| 590 | &channel_info->session_info_channels_ht_node); |
| 591 | rcu_read_unlock(); |
| 592 | } |
| 593 | |
| 594 | static |
| 595 | void session_info_remove_channel(struct session_info *session_info, |
| 596 | struct channel_info *channel_info) |
| 597 | { |
| 598 | rcu_read_lock(); |
| 599 | cds_lfht_del(session_info->channel_infos_ht, |
| 600 | &channel_info->session_info_channels_ht_node); |
| 601 | rcu_read_unlock(); |
| 602 | } |
| 603 | |
| 604 | static |
| 605 | struct channel_info *channel_info_create(const char *channel_name, |
| 606 | struct channel_key *channel_key, uint64_t channel_capacity, |
| 607 | struct session_info *session_info) |
| 608 | { |
| 609 | struct channel_info *channel_info = zmalloc(sizeof(*channel_info)); |
| 610 | |
| 611 | if (!channel_info) { |
| 612 | goto end; |
| 613 | } |
| 614 | |
| 615 | cds_lfht_node_init(&channel_info->channels_ht_node); |
| 616 | cds_lfht_node_init(&channel_info->session_info_channels_ht_node); |
| 617 | memcpy(&channel_info->key, channel_key, sizeof(*channel_key)); |
| 618 | channel_info->capacity = channel_capacity; |
| 619 | |
| 620 | channel_info->name = strdup(channel_name); |
| 621 | if (!channel_info->name) { |
| 622 | goto error; |
| 623 | } |
| 624 | |
| 625 | /* |
| 626 | * Set the references between session and channel infos: |
| 627 | * - channel_info holds a strong reference to session_info |
| 628 | * - session_info holds a weak reference to channel_info |
| 629 | */ |
| 630 | session_info_get(session_info); |
| 631 | session_info_add_channel(session_info, channel_info); |
| 632 | channel_info->session_info = session_info; |
| 633 | end: |
| 634 | return channel_info; |
| 635 | error: |
| 636 | channel_info_destroy(channel_info); |
| 637 | return NULL; |
| 638 | } |
| 639 | |
| 640 | /* This function must be called with the RCU read lock held. */ |
| 641 | static |
| 642 | int evaluate_condition_for_client(struct lttng_trigger *trigger, |
| 643 | struct lttng_condition *condition, |
| 644 | struct notification_client *client, |
| 645 | struct notification_thread_state *state) |
| 646 | { |
| 647 | int ret; |
| 648 | struct cds_lfht_iter iter; |
| 649 | struct cds_lfht_node *node; |
| 650 | struct channel_info *channel_info = NULL; |
| 651 | struct channel_key *channel_key = NULL; |
| 652 | struct channel_state_sample *last_sample = NULL; |
| 653 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
| 654 | struct lttng_evaluation *evaluation = NULL; |
| 655 | struct notification_client_list client_list = { 0 }; |
| 656 | struct notification_client_list_element client_list_element = { 0 }; |
| 657 | |
| 658 | assert(trigger); |
| 659 | assert(condition); |
| 660 | assert(client); |
| 661 | assert(state); |
| 662 | |
| 663 | /* Find the channel associated with the trigger. */ |
| 664 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, |
| 665 | channel_trigger_list , channel_triggers_ht_node) { |
| 666 | struct lttng_trigger_list_element *element; |
| 667 | |
| 668 | cds_list_for_each_entry(element, &channel_trigger_list->list, node) { |
| 669 | const struct lttng_condition *current_condition = |
| 670 | lttng_trigger_get_const_condition( |
| 671 | element->trigger); |
| 672 | |
| 673 | assert(current_condition); |
| 674 | if (!lttng_condition_is_equal(condition, |
| 675 | current_condition)) { |
| 676 | continue; |
| 677 | } |
| 678 | |
| 679 | /* Found the trigger, save the channel key. */ |
| 680 | channel_key = &channel_trigger_list->channel_key; |
| 681 | break; |
| 682 | } |
| 683 | if (channel_key) { |
| 684 | /* The channel key was found stop iteration. */ |
| 685 | break; |
| 686 | } |
| 687 | } |
| 688 | |
| 689 | if (!channel_key){ |
| 690 | /* No channel found; normal exit. */ |
| 691 | DBG("[notification-thread] No channel associated with newly subscribed-to condition"); |
| 692 | ret = 0; |
| 693 | goto end; |
| 694 | } |
| 695 | |
| 696 | /* Fetch channel info for the matching channel. */ |
| 697 | cds_lfht_lookup(state->channels_ht, |
| 698 | hash_channel_key(channel_key), |
| 699 | match_channel_info, |
| 700 | channel_key, |
| 701 | &iter); |
| 702 | node = cds_lfht_iter_get_node(&iter); |
| 703 | assert(node); |
| 704 | channel_info = caa_container_of(node, struct channel_info, |
| 705 | channels_ht_node); |
| 706 | |
| 707 | /* Retrieve the channel's last sample, if it exists. */ |
| 708 | cds_lfht_lookup(state->channel_state_ht, |
| 709 | hash_channel_key(channel_key), |
| 710 | match_channel_state_sample, |
| 711 | channel_key, |
| 712 | &iter); |
| 713 | node = cds_lfht_iter_get_node(&iter); |
| 714 | if (node) { |
| 715 | last_sample = caa_container_of(node, |
| 716 | struct channel_state_sample, |
| 717 | channel_state_ht_node); |
| 718 | } else { |
| 719 | /* Nothing to evaluate, no sample was ever taken. Normal exit */ |
| 720 | DBG("[notification-thread] No channel sample associated with newly subscribed-to condition"); |
| 721 | ret = 0; |
| 722 | goto end; |
| 723 | } |
| 724 | |
| 725 | ret = evaluate_condition(condition, &evaluation, state, |
| 726 | NULL, last_sample, |
| 727 | 0, channel_info->session_info->consumed_data_size, |
| 728 | channel_info); |
| 729 | if (ret) { |
| 730 | WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition"); |
| 731 | goto end; |
| 732 | } |
| 733 | |
| 734 | if (!evaluation) { |
| 735 | /* Evaluation yielded nothing. Normal exit. */ |
| 736 | DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client"); |
| 737 | ret = 0; |
| 738 | goto end; |
| 739 | } |
| 740 | |
| 741 | /* |
| 742 | * Create a temporary client list with the client currently |
| 743 | * subscribing. |
| 744 | */ |
| 745 | cds_lfht_node_init(&client_list.notification_trigger_ht_node); |
| 746 | CDS_INIT_LIST_HEAD(&client_list.list); |
| 747 | client_list.trigger = trigger; |
| 748 | |
| 749 | CDS_INIT_LIST_HEAD(&client_list_element.node); |
| 750 | client_list_element.client = client; |
| 751 | cds_list_add(&client_list_element.node, &client_list.list); |
| 752 | |
| 753 | /* Send evaluation result to the newly-subscribed client. */ |
| 754 | DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client"); |
| 755 | ret = send_evaluation_to_clients(trigger, evaluation, &client_list, |
| 756 | state, channel_info->session_info->uid, |
| 757 | channel_info->session_info->gid); |
| 758 | |
| 759 | end: |
| 760 | return ret; |
| 761 | } |
| 762 | |
| 763 | static |
| 764 | int notification_thread_client_subscribe(struct notification_client *client, |
| 765 | struct lttng_condition *condition, |
| 766 | struct notification_thread_state *state, |
| 767 | enum lttng_notification_channel_status *_status) |
| 768 | { |
| 769 | int ret = 0; |
| 770 | struct cds_lfht_iter iter; |
| 771 | struct cds_lfht_node *node; |
| 772 | struct notification_client_list *client_list; |
| 773 | struct lttng_condition_list_element *condition_list_element = NULL; |
| 774 | struct notification_client_list_element *client_list_element = NULL; |
| 775 | enum lttng_notification_channel_status status = |
| 776 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 777 | |
| 778 | /* |
| 779 | * Ensure that the client has not already subscribed to this condition |
| 780 | * before. |
| 781 | */ |
| 782 | cds_list_for_each_entry(condition_list_element, &client->condition_list, node) { |
| 783 | if (lttng_condition_is_equal(condition_list_element->condition, |
| 784 | condition)) { |
| 785 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED; |
| 786 | goto end; |
| 787 | } |
| 788 | } |
| 789 | |
| 790 | condition_list_element = zmalloc(sizeof(*condition_list_element)); |
| 791 | if (!condition_list_element) { |
| 792 | ret = -1; |
| 793 | goto error; |
| 794 | } |
| 795 | client_list_element = zmalloc(sizeof(*client_list_element)); |
| 796 | if (!client_list_element) { |
| 797 | ret = -1; |
| 798 | goto error; |
| 799 | } |
| 800 | |
| 801 | rcu_read_lock(); |
| 802 | |
| 803 | /* |
| 804 | * Add the newly-subscribed condition to the client's subscription list. |
| 805 | */ |
| 806 | CDS_INIT_LIST_HEAD(&condition_list_element->node); |
| 807 | condition_list_element->condition = condition; |
| 808 | cds_list_add(&condition_list_element->node, &client->condition_list); |
| 809 | |
| 810 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 811 | lttng_condition_hash(condition), |
| 812 | match_client_list_condition, |
| 813 | condition, |
| 814 | &iter); |
| 815 | node = cds_lfht_iter_get_node(&iter); |
| 816 | if (!node) { |
| 817 | /* |
| 818 | * No notification-emiting trigger registered with this |
| 819 | * condition. We don't evaluate the condition right away |
| 820 | * since this trigger is not registered yet. |
| 821 | */ |
| 822 | free(client_list_element); |
| 823 | goto end_unlock; |
| 824 | } |
| 825 | |
| 826 | client_list = caa_container_of(node, struct notification_client_list, |
| 827 | notification_trigger_ht_node); |
| 828 | /* |
| 829 | * The condition to which the client just subscribed is evaluated |
| 830 | * at this point so that conditions that are already TRUE result |
| 831 | * in a notification being sent out. |
| 832 | */ |
| 833 | if (evaluate_condition_for_client(client_list->trigger, condition, |
| 834 | client, state)) { |
| 835 | WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); |
| 836 | ret = -1; |
| 837 | free(client_list_element); |
| 838 | goto end_unlock; |
| 839 | } |
| 840 | |
| 841 | /* |
| 842 | * Add the client to the list of clients interested in a given trigger |
| 843 | * if a "notification" trigger with a corresponding condition was |
| 844 | * added prior. |
| 845 | */ |
| 846 | client_list_element->client = client; |
| 847 | CDS_INIT_LIST_HEAD(&client_list_element->node); |
| 848 | cds_list_add(&client_list_element->node, &client_list->list); |
| 849 | end_unlock: |
| 850 | rcu_read_unlock(); |
| 851 | end: |
| 852 | if (_status) { |
| 853 | *_status = status; |
| 854 | } |
| 855 | return ret; |
| 856 | error: |
| 857 | free(condition_list_element); |
| 858 | free(client_list_element); |
| 859 | return ret; |
| 860 | } |
| 861 | |
| 862 | static |
| 863 | int notification_thread_client_unsubscribe( |
| 864 | struct notification_client *client, |
| 865 | struct lttng_condition *condition, |
| 866 | struct notification_thread_state *state, |
| 867 | enum lttng_notification_channel_status *_status) |
| 868 | { |
| 869 | struct cds_lfht_iter iter; |
| 870 | struct cds_lfht_node *node; |
| 871 | struct notification_client_list *client_list; |
| 872 | struct lttng_condition_list_element *condition_list_element, |
| 873 | *condition_tmp; |
| 874 | struct notification_client_list_element *client_list_element, |
| 875 | *client_tmp; |
| 876 | bool condition_found = false; |
| 877 | enum lttng_notification_channel_status status = |
| 878 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 879 | |
| 880 | /* Remove the condition from the client's condition list. */ |
| 881 | cds_list_for_each_entry_safe(condition_list_element, condition_tmp, |
| 882 | &client->condition_list, node) { |
| 883 | if (!lttng_condition_is_equal(condition_list_element->condition, |
| 884 | condition)) { |
| 885 | continue; |
| 886 | } |
| 887 | |
| 888 | cds_list_del(&condition_list_element->node); |
| 889 | /* |
| 890 | * The caller may be iterating on the client's conditions to |
| 891 | * tear down a client's connection. In this case, the condition |
| 892 | * will be destroyed at the end. |
| 893 | */ |
| 894 | if (condition != condition_list_element->condition) { |
| 895 | lttng_condition_destroy( |
| 896 | condition_list_element->condition); |
| 897 | } |
| 898 | free(condition_list_element); |
| 899 | condition_found = true; |
| 900 | break; |
| 901 | } |
| 902 | |
| 903 | if (!condition_found) { |
| 904 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION; |
| 905 | goto end; |
| 906 | } |
| 907 | |
| 908 | /* |
| 909 | * Remove the client from the list of clients interested the trigger |
| 910 | * matching the condition. |
| 911 | */ |
| 912 | rcu_read_lock(); |
| 913 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 914 | lttng_condition_hash(condition), |
| 915 | match_client_list_condition, |
| 916 | condition, |
| 917 | &iter); |
| 918 | node = cds_lfht_iter_get_node(&iter); |
| 919 | if (!node) { |
| 920 | goto end_unlock; |
| 921 | } |
| 922 | |
| 923 | client_list = caa_container_of(node, struct notification_client_list, |
| 924 | notification_trigger_ht_node); |
| 925 | cds_list_for_each_entry_safe(client_list_element, client_tmp, |
| 926 | &client_list->list, node) { |
| 927 | if (client_list_element->client->socket != client->socket) { |
| 928 | continue; |
| 929 | } |
| 930 | cds_list_del(&client_list_element->node); |
| 931 | free(client_list_element); |
| 932 | break; |
| 933 | } |
| 934 | end_unlock: |
| 935 | rcu_read_unlock(); |
| 936 | end: |
| 937 | lttng_condition_destroy(condition); |
| 938 | if (_status) { |
| 939 | *_status = status; |
| 940 | } |
| 941 | return 0; |
| 942 | } |
| 943 | |
| 944 | static |
| 945 | void notification_client_destroy(struct notification_client *client, |
| 946 | struct notification_thread_state *state) |
| 947 | { |
| 948 | struct lttng_condition_list_element *condition_list_element, *tmp; |
| 949 | |
| 950 | if (!client) { |
| 951 | return; |
| 952 | } |
| 953 | |
| 954 | /* Release all conditions to which the client was subscribed. */ |
| 955 | cds_list_for_each_entry_safe(condition_list_element, tmp, |
| 956 | &client->condition_list, node) { |
| 957 | (void) notification_thread_client_unsubscribe(client, |
| 958 | condition_list_element->condition, state, NULL); |
| 959 | } |
| 960 | |
| 961 | if (client->socket >= 0) { |
| 962 | (void) lttcomm_close_unix_sock(client->socket); |
| 963 | } |
| 964 | lttng_dynamic_buffer_reset(&client->communication.inbound.buffer); |
| 965 | lttng_dynamic_buffer_reset(&client->communication.outbound.buffer); |
| 966 | free(client); |
| 967 | } |
| 968 | |
| 969 | /* |
| 970 | * Call with rcu_read_lock held (and hold for the lifetime of the returned |
| 971 | * client pointer). |
| 972 | */ |
| 973 | static |
| 974 | struct notification_client *get_client_from_socket(int socket, |
| 975 | struct notification_thread_state *state) |
| 976 | { |
| 977 | struct cds_lfht_iter iter; |
| 978 | struct cds_lfht_node *node; |
| 979 | struct notification_client *client = NULL; |
| 980 | |
| 981 | cds_lfht_lookup(state->client_socket_ht, |
| 982 | hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed), |
| 983 | match_client, |
| 984 | (void *) (unsigned long) socket, |
| 985 | &iter); |
| 986 | node = cds_lfht_iter_get_node(&iter); |
| 987 | if (!node) { |
| 988 | goto end; |
| 989 | } |
| 990 | |
| 991 | client = caa_container_of(node, struct notification_client, |
| 992 | client_socket_ht_node); |
| 993 | end: |
| 994 | return client; |
| 995 | } |
| 996 | |
| 997 | static |
| 998 | bool buffer_usage_condition_applies_to_channel( |
| 999 | const struct lttng_condition *condition, |
| 1000 | const struct channel_info *channel_info) |
| 1001 | { |
| 1002 | enum lttng_condition_status status; |
| 1003 | enum lttng_domain_type condition_domain; |
| 1004 | const char *condition_session_name = NULL; |
| 1005 | const char *condition_channel_name = NULL; |
| 1006 | |
| 1007 | status = lttng_condition_buffer_usage_get_domain_type(condition, |
| 1008 | &condition_domain); |
| 1009 | assert(status == LTTNG_CONDITION_STATUS_OK); |
| 1010 | if (channel_info->key.domain != condition_domain) { |
| 1011 | goto fail; |
| 1012 | } |
| 1013 | |
| 1014 | status = lttng_condition_buffer_usage_get_session_name( |
| 1015 | condition, &condition_session_name); |
| 1016 | assert((status == LTTNG_CONDITION_STATUS_OK) && condition_session_name); |
| 1017 | |
| 1018 | status = lttng_condition_buffer_usage_get_channel_name( |
| 1019 | condition, &condition_channel_name); |
| 1020 | assert((status == LTTNG_CONDITION_STATUS_OK) && condition_channel_name); |
| 1021 | |
| 1022 | if (strcmp(channel_info->session_info->name, condition_session_name)) { |
| 1023 | goto fail; |
| 1024 | } |
| 1025 | if (strcmp(channel_info->name, condition_channel_name)) { |
| 1026 | goto fail; |
| 1027 | } |
| 1028 | |
| 1029 | return true; |
| 1030 | fail: |
| 1031 | return false; |
| 1032 | } |
| 1033 | |
| 1034 | static |
| 1035 | bool session_consumed_size_condition_applies_to_channel( |
| 1036 | const struct lttng_condition *condition, |
| 1037 | const struct channel_info *channel_info) |
| 1038 | { |
| 1039 | enum lttng_condition_status status; |
| 1040 | const char *condition_session_name = NULL; |
| 1041 | |
| 1042 | status = lttng_condition_session_consumed_size_get_session_name( |
| 1043 | condition, &condition_session_name); |
| 1044 | assert((status == LTTNG_CONDITION_STATUS_OK) && condition_session_name); |
| 1045 | |
| 1046 | if (strcmp(channel_info->session_info->name, condition_session_name)) { |
| 1047 | goto fail; |
| 1048 | } |
| 1049 | |
| 1050 | return true; |
| 1051 | fail: |
| 1052 | return false; |
| 1053 | } |
| 1054 | |
| 1055 | /* |
| 1056 | * Get the type of object to which a given trigger applies. Binding lets |
| 1057 | * the notification system evaluate a trigger's condition when a given |
| 1058 | * object's state is updated. |
| 1059 | * |
| 1060 | * For instance, a condition bound to a channel will be evaluated everytime |
| 1061 | * the channel's state is changed by a channel monitoring sample. |
| 1062 | */ |
| 1063 | static |
| 1064 | enum lttng_object_type get_trigger_binding_object( |
| 1065 | const struct lttng_trigger *trigger) |
| 1066 | { |
| 1067 | const struct lttng_condition *condition; |
| 1068 | |
| 1069 | condition = lttng_trigger_get_const_condition(trigger); |
| 1070 | switch (lttng_condition_get_type(condition)) { |
| 1071 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 1072 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 1073 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 1074 | return LTTNG_OBJECT_TYPE_CHANNEL; |
| 1075 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 1076 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 1077 | return LTTNG_OBJECT_TYPE_SESSION; |
| 1078 | default: |
| 1079 | return LTTNG_OBJECT_TYPE_UNKNOWN; |
| 1080 | } |
| 1081 | } |
| 1082 | |
| 1083 | static |
| 1084 | bool trigger_applies_to_channel(const struct lttng_trigger *trigger, |
| 1085 | const struct channel_info *channel_info) |
| 1086 | { |
| 1087 | const struct lttng_condition *condition; |
| 1088 | bool trigger_applies; |
| 1089 | |
| 1090 | condition = lttng_trigger_get_const_condition(trigger); |
| 1091 | if (!condition) { |
| 1092 | goto fail; |
| 1093 | } |
| 1094 | |
| 1095 | switch (lttng_condition_get_type(condition)) { |
| 1096 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 1097 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 1098 | trigger_applies = buffer_usage_condition_applies_to_channel( |
| 1099 | condition, channel_info); |
| 1100 | break; |
| 1101 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 1102 | trigger_applies = session_consumed_size_condition_applies_to_channel( |
| 1103 | condition, channel_info); |
| 1104 | break; |
| 1105 | default: |
| 1106 | goto fail; |
| 1107 | } |
| 1108 | |
| 1109 | return trigger_applies; |
| 1110 | fail: |
| 1111 | return false; |
| 1112 | } |
| 1113 | |
| 1114 | static |
| 1115 | bool trigger_applies_to_client(struct lttng_trigger *trigger, |
| 1116 | struct notification_client *client) |
| 1117 | { |
| 1118 | bool applies = false; |
| 1119 | struct lttng_condition_list_element *condition_list_element; |
| 1120 | |
| 1121 | cds_list_for_each_entry(condition_list_element, &client->condition_list, |
| 1122 | node) { |
| 1123 | applies = lttng_condition_is_equal( |
| 1124 | condition_list_element->condition, |
| 1125 | lttng_trigger_get_condition(trigger)); |
| 1126 | if (applies) { |
| 1127 | break; |
| 1128 | } |
| 1129 | } |
| 1130 | return applies; |
| 1131 | } |
| 1132 | |
| 1133 | static |
| 1134 | int match_session(struct cds_lfht_node *node, const void *key) |
| 1135 | { |
| 1136 | const char *name = key; |
| 1137 | struct session_info *session_info = caa_container_of( |
| 1138 | node, struct session_info, sessions_ht_node); |
| 1139 | |
| 1140 | return !strcmp(session_info->name, name); |
| 1141 | } |
| 1142 | |
| 1143 | /* |
| 1144 | * Allocate an empty lttng_session_trigger_list for the session named |
| 1145 | * 'session_name'. |
| 1146 | * |
| 1147 | * No ownership of 'session_name' is assumed by the session trigger list. |
| 1148 | * It is the caller's responsability to ensure the session name is alive |
| 1149 | * for as long as this list is. |
| 1150 | */ |
| 1151 | static |
| 1152 | struct lttng_session_trigger_list *lttng_session_trigger_list_create( |
| 1153 | const char *session_name, |
| 1154 | struct cds_lfht *session_triggers_ht) |
| 1155 | { |
| 1156 | struct lttng_session_trigger_list *list; |
| 1157 | |
| 1158 | list = zmalloc(sizeof(*list)); |
| 1159 | if (!list) { |
| 1160 | goto end; |
| 1161 | } |
| 1162 | list->session_name = session_name; |
| 1163 | CDS_INIT_LIST_HEAD(&list->list); |
| 1164 | cds_lfht_node_init(&list->session_triggers_ht_node); |
| 1165 | list->session_triggers_ht = session_triggers_ht; |
| 1166 | |
| 1167 | rcu_read_lock(); |
| 1168 | /* Publish the list through the session_triggers_ht. */ |
| 1169 | cds_lfht_add(session_triggers_ht, |
| 1170 | hash_key_str(session_name, lttng_ht_seed), |
| 1171 | &list->session_triggers_ht_node); |
| 1172 | rcu_read_unlock(); |
| 1173 | end: |
| 1174 | return list; |
| 1175 | } |
| 1176 | |
| 1177 | static |
| 1178 | void free_session_trigger_list_rcu(struct rcu_head *node) |
| 1179 | { |
| 1180 | free(caa_container_of(node, struct lttng_session_trigger_list, |
| 1181 | rcu_node)); |
| 1182 | } |
| 1183 | |
| 1184 | static |
| 1185 | void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list *list) |
| 1186 | { |
| 1187 | struct lttng_trigger_list_element *trigger_list_element, *tmp; |
| 1188 | |
| 1189 | /* Empty the list element by element, and then free the list itself. */ |
| 1190 | cds_list_for_each_entry_safe(trigger_list_element, tmp, |
| 1191 | &list->list, node) { |
| 1192 | cds_list_del(&trigger_list_element->node); |
| 1193 | free(trigger_list_element); |
| 1194 | } |
| 1195 | rcu_read_lock(); |
| 1196 | /* Unpublish the list from the session_triggers_ht. */ |
| 1197 | cds_lfht_del(list->session_triggers_ht, |
| 1198 | &list->session_triggers_ht_node); |
| 1199 | rcu_read_unlock(); |
| 1200 | call_rcu(&list->rcu_node, free_session_trigger_list_rcu); |
| 1201 | } |
| 1202 | |
| 1203 | static |
| 1204 | int lttng_session_trigger_list_add(struct lttng_session_trigger_list *list, |
| 1205 | const struct lttng_trigger *trigger) |
| 1206 | { |
| 1207 | int ret = 0; |
| 1208 | struct lttng_trigger_list_element *new_element = |
| 1209 | zmalloc(sizeof(*new_element)); |
| 1210 | |
| 1211 | if (!new_element) { |
| 1212 | ret = -1; |
| 1213 | goto end; |
| 1214 | } |
| 1215 | CDS_INIT_LIST_HEAD(&new_element->node); |
| 1216 | new_element->trigger = trigger; |
| 1217 | cds_list_add(&new_element->node, &list->list); |
| 1218 | end: |
| 1219 | return ret; |
| 1220 | } |
| 1221 | |
| 1222 | static |
| 1223 | bool trigger_applies_to_session(const struct lttng_trigger *trigger, |
| 1224 | const char *session_name) |
| 1225 | { |
| 1226 | bool applies = false; |
| 1227 | const struct lttng_condition *condition; |
| 1228 | |
| 1229 | condition = lttng_trigger_get_const_condition(trigger); |
| 1230 | switch (lttng_condition_get_type(condition)) { |
| 1231 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 1232 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 1233 | { |
| 1234 | enum lttng_condition_status condition_status; |
| 1235 | const char *condition_session_name; |
| 1236 | |
| 1237 | condition_status = lttng_condition_session_rotation_get_session_name( |
| 1238 | condition, &condition_session_name); |
| 1239 | if (condition_status != LTTNG_CONDITION_STATUS_OK) { |
| 1240 | ERR("[notification-thread] Failed to retrieve session rotation condition's session name"); |
| 1241 | goto end; |
| 1242 | } |
| 1243 | |
| 1244 | assert(condition_session_name); |
| 1245 | applies = !strcmp(condition_session_name, session_name); |
| 1246 | break; |
| 1247 | } |
| 1248 | default: |
| 1249 | goto end; |
| 1250 | } |
| 1251 | end: |
| 1252 | return applies; |
| 1253 | } |
| 1254 | |
| 1255 | /* |
| 1256 | * Allocate and initialize an lttng_session_trigger_list which contains |
| 1257 | * all triggers that apply to the session named 'session_name'. |
| 1258 | * |
| 1259 | * No ownership of 'session_name' is assumed by the session trigger list. |
| 1260 | * It is the caller's responsability to ensure the session name is alive |
| 1261 | * for as long as this list is. |
| 1262 | */ |
| 1263 | static |
| 1264 | struct lttng_session_trigger_list *lttng_session_trigger_list_build( |
| 1265 | const struct notification_thread_state *state, |
| 1266 | const char *session_name) |
| 1267 | { |
| 1268 | int trigger_count = 0; |
| 1269 | struct lttng_session_trigger_list *session_trigger_list = NULL; |
| 1270 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1271 | struct cds_lfht_iter iter; |
| 1272 | |
| 1273 | session_trigger_list = lttng_session_trigger_list_create(session_name, |
| 1274 | state->session_triggers_ht); |
| 1275 | |
| 1276 | /* Add all triggers applying to the session named 'session_name'. */ |
| 1277 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 1278 | node) { |
| 1279 | int ret; |
| 1280 | |
| 1281 | if (!trigger_applies_to_session(trigger_ht_element->trigger, |
| 1282 | session_name)) { |
| 1283 | continue; |
| 1284 | } |
| 1285 | |
| 1286 | ret = lttng_session_trigger_list_add(session_trigger_list, |
| 1287 | trigger_ht_element->trigger); |
| 1288 | if (ret) { |
| 1289 | goto error; |
| 1290 | } |
| 1291 | |
| 1292 | trigger_count++; |
| 1293 | } |
| 1294 | |
| 1295 | DBG("[notification-thread] Found %i triggers that apply to newly created session", |
| 1296 | trigger_count); |
| 1297 | return session_trigger_list; |
| 1298 | error: |
| 1299 | lttng_session_trigger_list_destroy(session_trigger_list); |
| 1300 | return NULL; |
| 1301 | } |
| 1302 | |
| 1303 | static |
| 1304 | struct session_info *find_or_create_session_info( |
| 1305 | struct notification_thread_state *state, |
| 1306 | const char *name, uid_t uid, gid_t gid) |
| 1307 | { |
| 1308 | struct session_info *session = NULL; |
| 1309 | struct cds_lfht_node *node; |
| 1310 | struct cds_lfht_iter iter; |
| 1311 | struct lttng_session_trigger_list *trigger_list; |
| 1312 | |
| 1313 | rcu_read_lock(); |
| 1314 | cds_lfht_lookup(state->sessions_ht, |
| 1315 | hash_key_str(name, lttng_ht_seed), |
| 1316 | match_session, |
| 1317 | name, |
| 1318 | &iter); |
| 1319 | node = cds_lfht_iter_get_node(&iter); |
| 1320 | if (node) { |
| 1321 | DBG("[notification-thread] Found session info of session \"%s\" (uid = %i, gid = %i)", |
| 1322 | name, uid, gid); |
| 1323 | session = caa_container_of(node, struct session_info, |
| 1324 | sessions_ht_node); |
| 1325 | assert(session->uid == uid); |
| 1326 | assert(session->gid == gid); |
| 1327 | session_info_get(session); |
| 1328 | goto end; |
| 1329 | } |
| 1330 | |
| 1331 | trigger_list = lttng_session_trigger_list_build(state, name); |
| 1332 | if (!trigger_list) { |
| 1333 | goto error; |
| 1334 | } |
| 1335 | |
| 1336 | session = session_info_create(name, uid, gid, trigger_list, |
| 1337 | state->sessions_ht); |
| 1338 | if (!session) { |
| 1339 | ERR("[notification-thread] Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)", |
| 1340 | name, uid, gid); |
| 1341 | goto error; |
| 1342 | } |
| 1343 | trigger_list = NULL; |
| 1344 | |
| 1345 | cds_lfht_add(state->sessions_ht, hash_key_str(name, lttng_ht_seed), |
| 1346 | &session->sessions_ht_node); |
| 1347 | end: |
| 1348 | rcu_read_unlock(); |
| 1349 | return session; |
| 1350 | error: |
| 1351 | rcu_read_unlock(); |
| 1352 | session_info_put(session); |
| 1353 | return NULL; |
| 1354 | } |
| 1355 | |
| 1356 | static |
| 1357 | int handle_notification_thread_command_add_channel( |
| 1358 | struct notification_thread_state *state, |
| 1359 | const char *session_name, uid_t session_uid, gid_t session_gid, |
| 1360 | const char *channel_name, enum lttng_domain_type channel_domain, |
| 1361 | uint64_t channel_key_int, uint64_t channel_capacity, |
| 1362 | enum lttng_error_code *cmd_result) |
| 1363 | { |
| 1364 | struct cds_list_head trigger_list; |
| 1365 | struct channel_info *new_channel_info = NULL; |
| 1366 | struct channel_key channel_key = { |
| 1367 | .key = channel_key_int, |
| 1368 | .domain = channel_domain, |
| 1369 | }; |
| 1370 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
| 1371 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1372 | int trigger_count = 0; |
| 1373 | struct cds_lfht_iter iter; |
| 1374 | struct session_info *session_info = NULL; |
| 1375 | |
| 1376 | DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", |
| 1377 | channel_name, session_name, channel_key_int, |
| 1378 | channel_domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); |
| 1379 | |
| 1380 | CDS_INIT_LIST_HEAD(&trigger_list); |
| 1381 | |
| 1382 | session_info = find_or_create_session_info(state, session_name, |
| 1383 | session_uid, session_gid); |
| 1384 | if (!session_info) { |
| 1385 | /* Allocation error or an internal error occured. */ |
| 1386 | goto error; |
| 1387 | } |
| 1388 | |
| 1389 | new_channel_info = channel_info_create(channel_name, &channel_key, |
| 1390 | channel_capacity, session_info); |
| 1391 | if (!new_channel_info) { |
| 1392 | goto error; |
| 1393 | } |
| 1394 | |
| 1395 | /* Build a list of all triggers applying to the new channel. */ |
| 1396 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 1397 | node) { |
| 1398 | struct lttng_trigger_list_element *new_element; |
| 1399 | |
| 1400 | if (!trigger_applies_to_channel(trigger_ht_element->trigger, |
| 1401 | new_channel_info)) { |
| 1402 | continue; |
| 1403 | } |
| 1404 | |
| 1405 | new_element = zmalloc(sizeof(*new_element)); |
| 1406 | if (!new_element) { |
| 1407 | goto error; |
| 1408 | } |
| 1409 | CDS_INIT_LIST_HEAD(&new_element->node); |
| 1410 | new_element->trigger = trigger_ht_element->trigger; |
| 1411 | cds_list_add(&new_element->node, &trigger_list); |
| 1412 | trigger_count++; |
| 1413 | } |
| 1414 | |
| 1415 | DBG("[notification-thread] Found %i triggers that apply to newly added channel", |
| 1416 | trigger_count); |
| 1417 | channel_trigger_list = zmalloc(sizeof(*channel_trigger_list)); |
| 1418 | if (!channel_trigger_list) { |
| 1419 | goto error; |
| 1420 | } |
| 1421 | channel_trigger_list->channel_key = new_channel_info->key; |
| 1422 | CDS_INIT_LIST_HEAD(&channel_trigger_list->list); |
| 1423 | cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node); |
| 1424 | cds_list_splice(&trigger_list, &channel_trigger_list->list); |
| 1425 | |
| 1426 | rcu_read_lock(); |
| 1427 | /* Add channel to the channel_ht which owns the channel_infos. */ |
| 1428 | cds_lfht_add(state->channels_ht, |
| 1429 | hash_channel_key(&new_channel_info->key), |
| 1430 | &new_channel_info->channels_ht_node); |
| 1431 | /* |
| 1432 | * Add the list of triggers associated with this channel to the |
| 1433 | * channel_triggers_ht. |
| 1434 | */ |
| 1435 | cds_lfht_add(state->channel_triggers_ht, |
| 1436 | hash_channel_key(&new_channel_info->key), |
| 1437 | &channel_trigger_list->channel_triggers_ht_node); |
| 1438 | rcu_read_unlock(); |
| 1439 | session_info_put(session_info); |
| 1440 | *cmd_result = LTTNG_OK; |
| 1441 | return 0; |
| 1442 | error: |
| 1443 | channel_info_destroy(new_channel_info); |
| 1444 | session_info_put(session_info); |
| 1445 | return 1; |
| 1446 | } |
| 1447 | |
| 1448 | static |
| 1449 | int handle_notification_thread_command_remove_channel( |
| 1450 | struct notification_thread_state *state, |
| 1451 | uint64_t channel_key, enum lttng_domain_type domain, |
| 1452 | enum lttng_error_code *cmd_result) |
| 1453 | { |
| 1454 | struct cds_lfht_node *node; |
| 1455 | struct cds_lfht_iter iter; |
| 1456 | struct lttng_channel_trigger_list *trigger_list; |
| 1457 | struct lttng_trigger_list_element *trigger_list_element, *tmp; |
| 1458 | struct channel_key key = { .key = channel_key, .domain = domain }; |
| 1459 | struct channel_info *channel_info; |
| 1460 | |
| 1461 | DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", |
| 1462 | channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); |
| 1463 | |
| 1464 | rcu_read_lock(); |
| 1465 | |
| 1466 | cds_lfht_lookup(state->channel_triggers_ht, |
| 1467 | hash_channel_key(&key), |
| 1468 | match_channel_trigger_list, |
| 1469 | &key, |
| 1470 | &iter); |
| 1471 | node = cds_lfht_iter_get_node(&iter); |
| 1472 | /* |
| 1473 | * There is a severe internal error if we are being asked to remove a |
| 1474 | * channel that doesn't exist. |
| 1475 | */ |
| 1476 | if (!node) { |
| 1477 | ERR("[notification-thread] Channel being removed is unknown to the notification thread"); |
| 1478 | goto end; |
| 1479 | } |
| 1480 | |
| 1481 | /* Free the list of triggers associated with this channel. */ |
| 1482 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 1483 | channel_triggers_ht_node); |
| 1484 | cds_list_for_each_entry_safe(trigger_list_element, tmp, |
| 1485 | &trigger_list->list, node) { |
| 1486 | cds_list_del(&trigger_list_element->node); |
| 1487 | free(trigger_list_element); |
| 1488 | } |
| 1489 | cds_lfht_del(state->channel_triggers_ht, node); |
| 1490 | free(trigger_list); |
| 1491 | |
| 1492 | /* Free sampled channel state. */ |
| 1493 | cds_lfht_lookup(state->channel_state_ht, |
| 1494 | hash_channel_key(&key), |
| 1495 | match_channel_state_sample, |
| 1496 | &key, |
| 1497 | &iter); |
| 1498 | node = cds_lfht_iter_get_node(&iter); |
| 1499 | /* |
| 1500 | * This is expected to be NULL if the channel is destroyed before we |
| 1501 | * received a sample. |
| 1502 | */ |
| 1503 | if (node) { |
| 1504 | struct channel_state_sample *sample = caa_container_of(node, |
| 1505 | struct channel_state_sample, |
| 1506 | channel_state_ht_node); |
| 1507 | |
| 1508 | cds_lfht_del(state->channel_state_ht, node); |
| 1509 | free(sample); |
| 1510 | } |
| 1511 | |
| 1512 | /* Remove the channel from the channels_ht and free it. */ |
| 1513 | cds_lfht_lookup(state->channels_ht, |
| 1514 | hash_channel_key(&key), |
| 1515 | match_channel_info, |
| 1516 | &key, |
| 1517 | &iter); |
| 1518 | node = cds_lfht_iter_get_node(&iter); |
| 1519 | assert(node); |
| 1520 | channel_info = caa_container_of(node, struct channel_info, |
| 1521 | channels_ht_node); |
| 1522 | cds_lfht_del(state->channels_ht, node); |
| 1523 | channel_info_destroy(channel_info); |
| 1524 | end: |
| 1525 | rcu_read_unlock(); |
| 1526 | *cmd_result = LTTNG_OK; |
| 1527 | return 0; |
| 1528 | } |
| 1529 | |
| 1530 | static |
| 1531 | int condition_is_supported(struct lttng_condition *condition) |
| 1532 | { |
| 1533 | int ret; |
| 1534 | |
| 1535 | switch (lttng_condition_get_type(condition)) { |
| 1536 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 1537 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 1538 | { |
| 1539 | enum lttng_domain_type domain; |
| 1540 | |
| 1541 | ret = lttng_condition_buffer_usage_get_domain_type(condition, |
| 1542 | &domain); |
| 1543 | if (ret) { |
| 1544 | ret = -1; |
| 1545 | goto end; |
| 1546 | } |
| 1547 | |
| 1548 | if (domain != LTTNG_DOMAIN_KERNEL) { |
| 1549 | ret = 1; |
| 1550 | goto end; |
| 1551 | } |
| 1552 | |
| 1553 | /* |
| 1554 | * Older kernel tracers don't expose the API to monitor their |
| 1555 | * buffers. Therefore, we reject triggers that require that |
| 1556 | * mechanism to be available to be evaluated. |
| 1557 | */ |
| 1558 | ret = kernel_supports_ring_buffer_snapshot_sample_positions( |
| 1559 | kernel_tracer_fd); |
| 1560 | break; |
| 1561 | } |
| 1562 | default: |
| 1563 | ret = 1; |
| 1564 | } |
| 1565 | end: |
| 1566 | return ret; |
| 1567 | } |
| 1568 | |
| 1569 | /* Must be called with RCU read lock held. */ |
| 1570 | static |
| 1571 | int bind_trigger_to_matching_session(const struct lttng_trigger *trigger, |
| 1572 | struct notification_thread_state *state) |
| 1573 | { |
| 1574 | int ret = 0; |
| 1575 | struct cds_lfht_node *node; |
| 1576 | struct cds_lfht_iter iter; |
| 1577 | const struct lttng_condition *condition; |
| 1578 | const char *session_name; |
| 1579 | struct lttng_session_trigger_list *trigger_list; |
| 1580 | |
| 1581 | condition = lttng_trigger_get_const_condition(trigger); |
| 1582 | switch (lttng_condition_get_type(condition)) { |
| 1583 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING: |
| 1584 | case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED: |
| 1585 | { |
| 1586 | enum lttng_condition_status status; |
| 1587 | |
| 1588 | status = lttng_condition_session_rotation_get_session_name( |
| 1589 | condition, &session_name); |
| 1590 | if (status != LTTNG_CONDITION_STATUS_OK) { |
| 1591 | ERR("[notification-thread] Failed to bind trigger to session: unable to get 'session_rotation' condition's session name"); |
| 1592 | ret = -1; |
| 1593 | goto end; |
| 1594 | } |
| 1595 | break; |
| 1596 | } |
| 1597 | default: |
| 1598 | ret = -1; |
| 1599 | goto end; |
| 1600 | } |
| 1601 | |
| 1602 | cds_lfht_lookup(state->session_triggers_ht, |
| 1603 | hash_key_str(session_name, lttng_ht_seed), |
| 1604 | match_session_trigger_list, |
| 1605 | session_name, |
| 1606 | &iter); |
| 1607 | node = cds_lfht_iter_get_node(&iter); |
| 1608 | if (!node) { |
| 1609 | /* |
| 1610 | * Not an error, the list of triggers applying to that session |
| 1611 | * will be initialized when the session is created. |
| 1612 | */ |
| 1613 | DBG("[notification-thread] Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system", |
| 1614 | session_name); |
| 1615 | goto end; |
| 1616 | } |
| 1617 | |
| 1618 | trigger_list = caa_container_of(node, |
| 1619 | struct lttng_session_trigger_list, |
| 1620 | session_triggers_ht_node); |
| 1621 | |
| 1622 | DBG("[notification-thread] Newly registered trigger bound to session \"%s\"", |
| 1623 | session_name); |
| 1624 | ret = lttng_session_trigger_list_add(trigger_list, trigger); |
| 1625 | end: |
| 1626 | return ret; |
| 1627 | } |
| 1628 | |
| 1629 | /* Must be called with RCU read lock held. */ |
| 1630 | static |
| 1631 | int bind_trigger_to_matching_channels(const struct lttng_trigger *trigger, |
| 1632 | struct notification_thread_state *state) |
| 1633 | { |
| 1634 | int ret = 0; |
| 1635 | struct cds_lfht_node *node; |
| 1636 | struct cds_lfht_iter iter; |
| 1637 | struct channel_info *channel; |
| 1638 | |
| 1639 | cds_lfht_for_each_entry(state->channels_ht, &iter, channel, |
| 1640 | channels_ht_node) { |
| 1641 | struct lttng_trigger_list_element *trigger_list_element; |
| 1642 | struct lttng_channel_trigger_list *trigger_list; |
| 1643 | |
| 1644 | if (!trigger_applies_to_channel(trigger, channel)) { |
| 1645 | continue; |
| 1646 | } |
| 1647 | |
| 1648 | cds_lfht_lookup(state->channel_triggers_ht, |
| 1649 | hash_channel_key(&channel->key), |
| 1650 | match_channel_trigger_list, |
| 1651 | &channel->key, |
| 1652 | &iter); |
| 1653 | node = cds_lfht_iter_get_node(&iter); |
| 1654 | assert(node); |
| 1655 | trigger_list = caa_container_of(node, |
| 1656 | struct lttng_channel_trigger_list, |
| 1657 | channel_triggers_ht_node); |
| 1658 | |
| 1659 | trigger_list_element = zmalloc(sizeof(*trigger_list_element)); |
| 1660 | if (!trigger_list_element) { |
| 1661 | ret = -1; |
| 1662 | goto end; |
| 1663 | } |
| 1664 | CDS_INIT_LIST_HEAD(&trigger_list_element->node); |
| 1665 | trigger_list_element->trigger = trigger; |
| 1666 | cds_list_add(&trigger_list_element->node, &trigger_list->list); |
| 1667 | DBG("[notification-thread] Newly registered trigger bound to channel \"%s\"", |
| 1668 | channel->name); |
| 1669 | } |
| 1670 | end: |
| 1671 | return ret; |
| 1672 | } |
| 1673 | |
| 1674 | /* |
| 1675 | * FIXME A client's credentials are not checked when registering a trigger, nor |
| 1676 | * are they stored alongside with the trigger. |
| 1677 | * |
| 1678 | * The effects of this are benign since: |
| 1679 | * - The client will succeed in registering the trigger, as it is valid, |
| 1680 | * - The trigger will, internally, be bound to the channel/session, |
| 1681 | * - The notifications will not be sent since the client's credentials |
| 1682 | * are checked against the channel at that moment. |
| 1683 | * |
| 1684 | * If this function returns a non-zero value, it means something is |
| 1685 | * fundamentally broken and the whole subsystem/thread will be torn down. |
| 1686 | * |
| 1687 | * If a non-fatal error occurs, just set the cmd_result to the appropriate |
| 1688 | * error code. |
| 1689 | */ |
| 1690 | static |
| 1691 | int handle_notification_thread_command_register_trigger( |
| 1692 | struct notification_thread_state *state, |
| 1693 | struct lttng_trigger *trigger, |
| 1694 | enum lttng_error_code *cmd_result) |
| 1695 | { |
| 1696 | int ret = 0; |
| 1697 | struct lttng_condition *condition; |
| 1698 | struct notification_client *client; |
| 1699 | struct notification_client_list *client_list = NULL; |
| 1700 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1701 | struct notification_client_list_element *client_list_element, *tmp; |
| 1702 | struct cds_lfht_node *node; |
| 1703 | struct cds_lfht_iter iter; |
| 1704 | bool free_trigger = true; |
| 1705 | |
| 1706 | rcu_read_lock(); |
| 1707 | |
| 1708 | condition = lttng_trigger_get_condition(trigger); |
| 1709 | assert(condition); |
| 1710 | |
| 1711 | ret = condition_is_supported(condition); |
| 1712 | if (ret < 0) { |
| 1713 | goto error; |
| 1714 | } else if (ret == 0) { |
| 1715 | *cmd_result = LTTNG_ERR_NOT_SUPPORTED; |
| 1716 | goto error; |
| 1717 | } else { |
| 1718 | /* Feature is supported, continue. */ |
| 1719 | ret = 0; |
| 1720 | } |
| 1721 | |
| 1722 | trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); |
| 1723 | if (!trigger_ht_element) { |
| 1724 | ret = -1; |
| 1725 | goto error; |
| 1726 | } |
| 1727 | |
| 1728 | /* Add trigger to the trigger_ht. */ |
| 1729 | cds_lfht_node_init(&trigger_ht_element->node); |
| 1730 | trigger_ht_element->trigger = trigger; |
| 1731 | |
| 1732 | node = cds_lfht_add_unique(state->triggers_ht, |
| 1733 | lttng_condition_hash(condition), |
| 1734 | match_condition, |
| 1735 | condition, |
| 1736 | &trigger_ht_element->node); |
| 1737 | if (node != &trigger_ht_element->node) { |
| 1738 | /* Not a fatal error, simply report it to the client. */ |
| 1739 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; |
| 1740 | goto error_free_ht_element; |
| 1741 | } |
| 1742 | |
| 1743 | /* |
| 1744 | * Ownership of the trigger and of its wrapper was transfered to |
| 1745 | * the triggers_ht. |
| 1746 | */ |
| 1747 | trigger_ht_element = NULL; |
| 1748 | free_trigger = false; |
| 1749 | |
| 1750 | /* |
| 1751 | * The rest only applies to triggers that have a "notify" action. |
| 1752 | * It is not skipped as this is the only action type currently |
| 1753 | * supported. |
| 1754 | */ |
| 1755 | client_list = zmalloc(sizeof(*client_list)); |
| 1756 | if (!client_list) { |
| 1757 | ret = -1; |
| 1758 | goto error_free_ht_element; |
| 1759 | } |
| 1760 | cds_lfht_node_init(&client_list->notification_trigger_ht_node); |
| 1761 | CDS_INIT_LIST_HEAD(&client_list->list); |
| 1762 | client_list->trigger = trigger; |
| 1763 | |
| 1764 | /* Build a list of clients to which this new trigger applies. */ |
| 1765 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, |
| 1766 | client_socket_ht_node) { |
| 1767 | if (!trigger_applies_to_client(trigger, client)) { |
| 1768 | continue; |
| 1769 | } |
| 1770 | |
| 1771 | client_list_element = zmalloc(sizeof(*client_list_element)); |
| 1772 | if (!client_list_element) { |
| 1773 | ret = -1; |
| 1774 | goto error_free_client_list; |
| 1775 | } |
| 1776 | CDS_INIT_LIST_HEAD(&client_list_element->node); |
| 1777 | client_list_element->client = client; |
| 1778 | cds_list_add(&client_list_element->node, &client_list->list); |
| 1779 | } |
| 1780 | |
| 1781 | cds_lfht_add(state->notification_trigger_clients_ht, |
| 1782 | lttng_condition_hash(condition), |
| 1783 | &client_list->notification_trigger_ht_node); |
| 1784 | |
| 1785 | switch (get_trigger_binding_object(trigger)) { |
| 1786 | case LTTNG_OBJECT_TYPE_SESSION: |
| 1787 | /* Add the trigger to the list if it matches a known session. */ |
| 1788 | ret = bind_trigger_to_matching_session(trigger, state); |
| 1789 | if (ret) { |
| 1790 | goto error_free_client_list; |
| 1791 | } |
| 1792 | case LTTNG_OBJECT_TYPE_CHANNEL: |
| 1793 | /* |
| 1794 | * Add the trigger to list of triggers bound to the channels |
| 1795 | * currently known. |
| 1796 | */ |
| 1797 | ret = bind_trigger_to_matching_channels(trigger, state); |
| 1798 | if (ret) { |
| 1799 | goto error_free_client_list; |
| 1800 | } |
| 1801 | break; |
| 1802 | case LTTNG_OBJECT_TYPE_NONE: |
| 1803 | break; |
| 1804 | default: |
| 1805 | ERR("[notification-thread] Unknown object type on which to bind a newly registered trigger was encountered"); |
| 1806 | ret = -1; |
| 1807 | goto error_free_client_list; |
| 1808 | } |
| 1809 | |
| 1810 | /* |
| 1811 | * Since there is nothing preventing clients from subscribing to a |
| 1812 | * condition before the corresponding trigger is registered, we have |
| 1813 | * to evaluate this new condition right away. |
| 1814 | * |
| 1815 | * At some point, we were waiting for the next "evaluation" (e.g. on |
| 1816 | * reception of a channel sample) to evaluate this new condition, but |
| 1817 | * that was broken. |
| 1818 | * |
| 1819 | * The reason it was broken is that waiting for the next sample |
| 1820 | * does not allow us to properly handle transitions for edge-triggered |
| 1821 | * conditions. |
| 1822 | * |
| 1823 | * Consider this example: when we handle a new channel sample, we |
| 1824 | * evaluate each conditions twice: once with the previous state, and |
| 1825 | * again with the newest state. We then use those two results to |
| 1826 | * determine whether a state change happened: a condition was false and |
| 1827 | * became true. If a state change happened, we have to notify clients. |
| 1828 | * |
| 1829 | * Now, if a client subscribes to a given notification and registers |
| 1830 | * a trigger *after* that subscription, we have to make sure the |
| 1831 | * condition is evaluated at this point while considering only the |
| 1832 | * current state. Otherwise, the next evaluation cycle may only see |
| 1833 | * that the evaluations remain the same (true for samples n-1 and n) and |
| 1834 | * the client will never know that the condition has been met. |
| 1835 | */ |
| 1836 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 1837 | &client_list->list, node) { |
| 1838 | ret = evaluate_condition_for_client(trigger, condition, |
| 1839 | client_list_element->client, state); |
| 1840 | if (ret) { |
| 1841 | goto error_free_client_list; |
| 1842 | } |
| 1843 | } |
| 1844 | |
| 1845 | /* |
| 1846 | * Client list ownership transferred to the |
| 1847 | * notification_trigger_clients_ht. |
| 1848 | */ |
| 1849 | client_list = NULL; |
| 1850 | |
| 1851 | *cmd_result = LTTNG_OK; |
| 1852 | error_free_client_list: |
| 1853 | if (client_list) { |
| 1854 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 1855 | &client_list->list, node) { |
| 1856 | free(client_list_element); |
| 1857 | } |
| 1858 | free(client_list); |
| 1859 | } |
| 1860 | error_free_ht_element: |
| 1861 | free(trigger_ht_element); |
| 1862 | error: |
| 1863 | if (free_trigger) { |
| 1864 | struct lttng_action *action = lttng_trigger_get_action(trigger); |
| 1865 | |
| 1866 | lttng_condition_destroy(condition); |
| 1867 | lttng_action_destroy(action); |
| 1868 | lttng_trigger_destroy(trigger); |
| 1869 | } |
| 1870 | rcu_read_unlock(); |
| 1871 | return ret; |
| 1872 | } |
| 1873 | |
| 1874 | static |
| 1875 | int handle_notification_thread_command_unregister_trigger( |
| 1876 | struct notification_thread_state *state, |
| 1877 | struct lttng_trigger *trigger, |
| 1878 | enum lttng_error_code *_cmd_reply) |
| 1879 | { |
| 1880 | struct cds_lfht_iter iter; |
| 1881 | struct cds_lfht_node *node, *triggers_ht_node; |
| 1882 | struct lttng_channel_trigger_list *trigger_list; |
| 1883 | struct notification_client_list *client_list; |
| 1884 | struct notification_client_list_element *client_list_element, *tmp; |
| 1885 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1886 | struct lttng_condition *condition = lttng_trigger_get_condition( |
| 1887 | trigger); |
| 1888 | struct lttng_action *action; |
| 1889 | enum lttng_error_code cmd_reply; |
| 1890 | |
| 1891 | rcu_read_lock(); |
| 1892 | |
| 1893 | cds_lfht_lookup(state->triggers_ht, |
| 1894 | lttng_condition_hash(condition), |
| 1895 | match_condition, |
| 1896 | condition, |
| 1897 | &iter); |
| 1898 | triggers_ht_node = cds_lfht_iter_get_node(&iter); |
| 1899 | if (!triggers_ht_node) { |
| 1900 | cmd_reply = LTTNG_ERR_TRIGGER_NOT_FOUND; |
| 1901 | goto end; |
| 1902 | } else { |
| 1903 | cmd_reply = LTTNG_OK; |
| 1904 | } |
| 1905 | |
| 1906 | /* Remove trigger from channel_triggers_ht. */ |
| 1907 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list, |
| 1908 | channel_triggers_ht_node) { |
| 1909 | struct lttng_trigger_list_element *trigger_element, *tmp; |
| 1910 | |
| 1911 | cds_list_for_each_entry_safe(trigger_element, tmp, |
| 1912 | &trigger_list->list, node) { |
| 1913 | const struct lttng_condition *current_condition = |
| 1914 | lttng_trigger_get_const_condition( |
| 1915 | trigger_element->trigger); |
| 1916 | |
| 1917 | assert(current_condition); |
| 1918 | if (!lttng_condition_is_equal(condition, |
| 1919 | current_condition)) { |
| 1920 | continue; |
| 1921 | } |
| 1922 | |
| 1923 | DBG("[notification-thread] Removed trigger from channel_triggers_ht"); |
| 1924 | cds_list_del(&trigger_element->node); |
| 1925 | /* A trigger can only appear once per channel */ |
| 1926 | break; |
| 1927 | } |
| 1928 | } |
| 1929 | |
| 1930 | /* |
| 1931 | * Remove and release the client list from |
| 1932 | * notification_trigger_clients_ht. |
| 1933 | */ |
| 1934 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 1935 | lttng_condition_hash(condition), |
| 1936 | match_client_list, |
| 1937 | trigger, |
| 1938 | &iter); |
| 1939 | node = cds_lfht_iter_get_node(&iter); |
| 1940 | assert(node); |
| 1941 | client_list = caa_container_of(node, struct notification_client_list, |
| 1942 | notification_trigger_ht_node); |
| 1943 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 1944 | &client_list->list, node) { |
| 1945 | free(client_list_element); |
| 1946 | } |
| 1947 | cds_lfht_del(state->notification_trigger_clients_ht, node); |
| 1948 | free(client_list); |
| 1949 | |
| 1950 | /* Remove trigger from triggers_ht. */ |
| 1951 | trigger_ht_element = caa_container_of(triggers_ht_node, |
| 1952 | struct lttng_trigger_ht_element, node); |
| 1953 | cds_lfht_del(state->triggers_ht, triggers_ht_node); |
| 1954 | |
| 1955 | condition = lttng_trigger_get_condition(trigger_ht_element->trigger); |
| 1956 | lttng_condition_destroy(condition); |
| 1957 | action = lttng_trigger_get_action(trigger_ht_element->trigger); |
| 1958 | lttng_action_destroy(action); |
| 1959 | lttng_trigger_destroy(trigger_ht_element->trigger); |
| 1960 | free(trigger_ht_element); |
| 1961 | end: |
| 1962 | rcu_read_unlock(); |
| 1963 | if (_cmd_reply) { |
| 1964 | *_cmd_reply = cmd_reply; |
| 1965 | } |
| 1966 | return 0; |
| 1967 | } |
| 1968 | |
| 1969 | /* Returns 0 on success, 1 on exit requested, negative value on error. */ |
| 1970 | int handle_notification_thread_command( |
| 1971 | struct notification_thread_handle *handle, |
| 1972 | struct notification_thread_state *state) |
| 1973 | { |
| 1974 | int ret; |
| 1975 | uint64_t counter; |
| 1976 | struct notification_thread_command *cmd; |
| 1977 | |
| 1978 | /* Read the event pipe to put it back into a quiescent state. */ |
| 1979 | ret = read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter, |
| 1980 | sizeof(counter)); |
| 1981 | if (ret == -1) { |
| 1982 | goto error; |
| 1983 | } |
| 1984 | |
| 1985 | pthread_mutex_lock(&handle->cmd_queue.lock); |
| 1986 | cmd = cds_list_first_entry(&handle->cmd_queue.list, |
| 1987 | struct notification_thread_command, cmd_list_node); |
| 1988 | switch (cmd->type) { |
| 1989 | case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: |
| 1990 | DBG("[notification-thread] Received register trigger command"); |
| 1991 | ret = handle_notification_thread_command_register_trigger( |
| 1992 | state, cmd->parameters.trigger, |
| 1993 | &cmd->reply_code); |
| 1994 | break; |
| 1995 | case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: |
| 1996 | DBG("[notification-thread] Received unregister trigger command"); |
| 1997 | ret = handle_notification_thread_command_unregister_trigger( |
| 1998 | state, cmd->parameters.trigger, |
| 1999 | &cmd->reply_code); |
| 2000 | break; |
| 2001 | case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: |
| 2002 | DBG("[notification-thread] Received add channel command"); |
| 2003 | ret = handle_notification_thread_command_add_channel( |
| 2004 | state, |
| 2005 | cmd->parameters.add_channel.session.name, |
| 2006 | cmd->parameters.add_channel.session.uid, |
| 2007 | cmd->parameters.add_channel.session.gid, |
| 2008 | cmd->parameters.add_channel.channel.name, |
| 2009 | cmd->parameters.add_channel.channel.domain, |
| 2010 | cmd->parameters.add_channel.channel.key, |
| 2011 | cmd->parameters.add_channel.channel.capacity, |
| 2012 | &cmd->reply_code); |
| 2013 | break; |
| 2014 | case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: |
| 2015 | DBG("[notification-thread] Received remove channel command"); |
| 2016 | ret = handle_notification_thread_command_remove_channel( |
| 2017 | state, cmd->parameters.remove_channel.key, |
| 2018 | cmd->parameters.remove_channel.domain, |
| 2019 | &cmd->reply_code); |
| 2020 | break; |
| 2021 | case NOTIFICATION_COMMAND_TYPE_QUIT: |
| 2022 | DBG("[notification-thread] Received quit command"); |
| 2023 | cmd->reply_code = LTTNG_OK; |
| 2024 | ret = 1; |
| 2025 | goto end; |
| 2026 | default: |
| 2027 | ERR("[notification-thread] Unknown internal command received"); |
| 2028 | goto error_unlock; |
| 2029 | } |
| 2030 | |
| 2031 | if (ret) { |
| 2032 | goto error_unlock; |
| 2033 | } |
| 2034 | end: |
| 2035 | cds_list_del(&cmd->cmd_list_node); |
| 2036 | lttng_waiter_wake_up(&cmd->reply_waiter); |
| 2037 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
| 2038 | return ret; |
| 2039 | error_unlock: |
| 2040 | /* Wake-up and return a fatal error to the calling thread. */ |
| 2041 | lttng_waiter_wake_up(&cmd->reply_waiter); |
| 2042 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
| 2043 | cmd->reply_code = LTTNG_ERR_FATAL; |
| 2044 | error: |
| 2045 | /* Indicate a fatal error to the caller. */ |
| 2046 | return -1; |
| 2047 | } |
| 2048 | |
| 2049 | static |
| 2050 | unsigned long hash_client_socket(int socket) |
| 2051 | { |
| 2052 | return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed); |
| 2053 | } |
| 2054 | |
| 2055 | static |
| 2056 | int socket_set_non_blocking(int socket) |
| 2057 | { |
| 2058 | int ret, flags; |
| 2059 | |
| 2060 | /* Set the pipe as non-blocking. */ |
| 2061 | ret = fcntl(socket, F_GETFL, 0); |
| 2062 | if (ret == -1) { |
| 2063 | PERROR("fcntl get socket flags"); |
| 2064 | goto end; |
| 2065 | } |
| 2066 | flags = ret; |
| 2067 | |
| 2068 | ret = fcntl(socket, F_SETFL, flags | O_NONBLOCK); |
| 2069 | if (ret == -1) { |
| 2070 | PERROR("fcntl set O_NONBLOCK socket flag"); |
| 2071 | goto end; |
| 2072 | } |
| 2073 | DBG("Client socket (fd = %i) set as non-blocking", socket); |
| 2074 | end: |
| 2075 | return ret; |
| 2076 | } |
| 2077 | |
| 2078 | static |
| 2079 | int client_reset_inbound_state(struct notification_client *client) |
| 2080 | { |
| 2081 | int ret; |
| 2082 | |
| 2083 | ret = lttng_dynamic_buffer_set_size( |
| 2084 | &client->communication.inbound.buffer, 0); |
| 2085 | assert(!ret); |
| 2086 | |
| 2087 | client->communication.inbound.bytes_to_receive = |
| 2088 | sizeof(struct lttng_notification_channel_message); |
| 2089 | client->communication.inbound.msg_type = |
| 2090 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN; |
| 2091 | LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1); |
| 2092 | LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1); |
| 2093 | ret = lttng_dynamic_buffer_set_size( |
| 2094 | &client->communication.inbound.buffer, |
| 2095 | client->communication.inbound.bytes_to_receive); |
| 2096 | return ret; |
| 2097 | } |
| 2098 | |
| 2099 | int handle_notification_thread_client_connect( |
| 2100 | struct notification_thread_state *state) |
| 2101 | { |
| 2102 | int ret; |
| 2103 | struct notification_client *client; |
| 2104 | |
| 2105 | DBG("[notification-thread] Handling new notification channel client connection"); |
| 2106 | |
| 2107 | client = zmalloc(sizeof(*client)); |
| 2108 | if (!client) { |
| 2109 | /* Fatal error. */ |
| 2110 | ret = -1; |
| 2111 | goto error; |
| 2112 | } |
| 2113 | CDS_INIT_LIST_HEAD(&client->condition_list); |
| 2114 | lttng_dynamic_buffer_init(&client->communication.inbound.buffer); |
| 2115 | lttng_dynamic_buffer_init(&client->communication.outbound.buffer); |
| 2116 | client->communication.inbound.expect_creds = true; |
| 2117 | ret = client_reset_inbound_state(client); |
| 2118 | if (ret) { |
| 2119 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 2120 | ret = 0; |
| 2121 | goto error; |
| 2122 | } |
| 2123 | |
| 2124 | ret = lttcomm_accept_unix_sock(state->notification_channel_socket); |
| 2125 | if (ret < 0) { |
| 2126 | ERR("[notification-thread] Failed to accept new notification channel client connection"); |
| 2127 | ret = 0; |
| 2128 | goto error; |
| 2129 | } |
| 2130 | |
| 2131 | client->socket = ret; |
| 2132 | |
| 2133 | ret = socket_set_non_blocking(client->socket); |
| 2134 | if (ret) { |
| 2135 | ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking"); |
| 2136 | goto error; |
| 2137 | } |
| 2138 | |
| 2139 | ret = lttcomm_setsockopt_creds_unix_sock(client->socket); |
| 2140 | if (ret < 0) { |
| 2141 | ERR("[notification-thread] Failed to set socket options on new notification channel client socket"); |
| 2142 | ret = 0; |
| 2143 | goto error; |
| 2144 | } |
| 2145 | |
| 2146 | ret = lttng_poll_add(&state->events, client->socket, |
| 2147 | LPOLLIN | LPOLLERR | |
| 2148 | LPOLLHUP | LPOLLRDHUP); |
| 2149 | if (ret < 0) { |
| 2150 | ERR("[notification-thread] Failed to add notification channel client socket to poll set"); |
| 2151 | ret = 0; |
| 2152 | goto error; |
| 2153 | } |
| 2154 | DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", |
| 2155 | client->socket); |
| 2156 | |
| 2157 | rcu_read_lock(); |
| 2158 | cds_lfht_add(state->client_socket_ht, |
| 2159 | hash_client_socket(client->socket), |
| 2160 | &client->client_socket_ht_node); |
| 2161 | rcu_read_unlock(); |
| 2162 | |
| 2163 | return ret; |
| 2164 | error: |
| 2165 | notification_client_destroy(client, state); |
| 2166 | return ret; |
| 2167 | } |
| 2168 | |
| 2169 | int handle_notification_thread_client_disconnect( |
| 2170 | int client_socket, |
| 2171 | struct notification_thread_state *state) |
| 2172 | { |
| 2173 | int ret = 0; |
| 2174 | struct notification_client *client; |
| 2175 | |
| 2176 | rcu_read_lock(); |
| 2177 | DBG("[notification-thread] Closing client connection (socket fd = %i)", |
| 2178 | client_socket); |
| 2179 | client = get_client_from_socket(client_socket, state); |
| 2180 | if (!client) { |
| 2181 | /* Internal state corruption, fatal error. */ |
| 2182 | ERR("[notification-thread] Unable to find client (socket fd = %i)", |
| 2183 | client_socket); |
| 2184 | ret = -1; |
| 2185 | goto end; |
| 2186 | } |
| 2187 | |
| 2188 | ret = lttng_poll_del(&state->events, client_socket); |
| 2189 | if (ret) { |
| 2190 | ERR("[notification-thread] Failed to remove client socket from poll set"); |
| 2191 | } |
| 2192 | cds_lfht_del(state->client_socket_ht, |
| 2193 | &client->client_socket_ht_node); |
| 2194 | notification_client_destroy(client, state); |
| 2195 | end: |
| 2196 | rcu_read_unlock(); |
| 2197 | return ret; |
| 2198 | } |
| 2199 | |
| 2200 | int handle_notification_thread_client_disconnect_all( |
| 2201 | struct notification_thread_state *state) |
| 2202 | { |
| 2203 | struct cds_lfht_iter iter; |
| 2204 | struct notification_client *client; |
| 2205 | bool error_encoutered = false; |
| 2206 | |
| 2207 | rcu_read_lock(); |
| 2208 | DBG("[notification-thread] Closing all client connections"); |
| 2209 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, |
| 2210 | client_socket_ht_node) { |
| 2211 | int ret; |
| 2212 | |
| 2213 | ret = handle_notification_thread_client_disconnect( |
| 2214 | client->socket, state); |
| 2215 | if (ret) { |
| 2216 | error_encoutered = true; |
| 2217 | } |
| 2218 | } |
| 2219 | rcu_read_unlock(); |
| 2220 | return error_encoutered ? 1 : 0; |
| 2221 | } |
| 2222 | |
| 2223 | int handle_notification_thread_trigger_unregister_all( |
| 2224 | struct notification_thread_state *state) |
| 2225 | { |
| 2226 | bool error_occurred = false; |
| 2227 | struct cds_lfht_iter iter; |
| 2228 | struct lttng_trigger_ht_element *trigger_ht_element; |
| 2229 | |
| 2230 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 2231 | node) { |
| 2232 | int ret = handle_notification_thread_command_unregister_trigger( |
| 2233 | state, trigger_ht_element->trigger, NULL); |
| 2234 | if (ret) { |
| 2235 | error_occurred = true; |
| 2236 | } |
| 2237 | } |
| 2238 | return error_occurred ? -1 : 0; |
| 2239 | } |
| 2240 | |
| 2241 | static |
| 2242 | int client_flush_outgoing_queue(struct notification_client *client, |
| 2243 | struct notification_thread_state *state) |
| 2244 | { |
| 2245 | ssize_t ret; |
| 2246 | size_t to_send_count; |
| 2247 | |
| 2248 | assert(client->communication.outbound.buffer.size != 0); |
| 2249 | to_send_count = client->communication.outbound.buffer.size; |
| 2250 | DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", |
| 2251 | client->socket); |
| 2252 | |
| 2253 | ret = lttcomm_send_unix_sock_non_block(client->socket, |
| 2254 | client->communication.outbound.buffer.data, |
| 2255 | to_send_count); |
| 2256 | if ((ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) || |
| 2257 | (ret > 0 && ret < to_send_count)) { |
| 2258 | DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", |
| 2259 | client->socket); |
| 2260 | to_send_count -= max(ret, 0); |
| 2261 | |
| 2262 | memcpy(client->communication.outbound.buffer.data, |
| 2263 | client->communication.outbound.buffer.data + |
| 2264 | client->communication.outbound.buffer.size - to_send_count, |
| 2265 | to_send_count); |
| 2266 | ret = lttng_dynamic_buffer_set_size( |
| 2267 | &client->communication.outbound.buffer, |
| 2268 | to_send_count); |
| 2269 | if (ret) { |
| 2270 | goto error; |
| 2271 | } |
| 2272 | |
| 2273 | /* |
| 2274 | * We want to be notified whenever there is buffer space |
| 2275 | * available to send the rest of the payload. |
| 2276 | */ |
| 2277 | ret = lttng_poll_mod(&state->events, client->socket, |
| 2278 | CLIENT_POLL_MASK_IN_OUT); |
| 2279 | if (ret) { |
| 2280 | goto error; |
| 2281 | } |
| 2282 | } else if (ret < 0) { |
| 2283 | /* Generic error, disconnect the client. */ |
| 2284 | ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)", |
| 2285 | client->socket); |
| 2286 | ret = handle_notification_thread_client_disconnect( |
| 2287 | client->socket, state); |
| 2288 | if (ret) { |
| 2289 | goto error; |
| 2290 | } |
| 2291 | } else { |
| 2292 | /* No error and flushed the queue completely. */ |
| 2293 | ret = lttng_dynamic_buffer_set_size( |
| 2294 | &client->communication.outbound.buffer, 0); |
| 2295 | if (ret) { |
| 2296 | goto error; |
| 2297 | } |
| 2298 | ret = lttng_poll_mod(&state->events, client->socket, |
| 2299 | CLIENT_POLL_MASK_IN); |
| 2300 | if (ret) { |
| 2301 | goto error; |
| 2302 | } |
| 2303 | |
| 2304 | client->communication.outbound.queued_command_reply = false; |
| 2305 | client->communication.outbound.dropped_notification = false; |
| 2306 | } |
| 2307 | |
| 2308 | return 0; |
| 2309 | error: |
| 2310 | return -1; |
| 2311 | } |
| 2312 | |
| 2313 | static |
| 2314 | int client_send_command_reply(struct notification_client *client, |
| 2315 | struct notification_thread_state *state, |
| 2316 | enum lttng_notification_channel_status status) |
| 2317 | { |
| 2318 | int ret; |
| 2319 | struct lttng_notification_channel_command_reply reply = { |
| 2320 | .status = (int8_t) status, |
| 2321 | }; |
| 2322 | struct lttng_notification_channel_message msg = { |
| 2323 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY, |
| 2324 | .size = sizeof(reply), |
| 2325 | }; |
| 2326 | char buffer[sizeof(msg) + sizeof(reply)]; |
| 2327 | |
| 2328 | if (client->communication.outbound.queued_command_reply) { |
| 2329 | /* Protocol error. */ |
| 2330 | goto error; |
| 2331 | } |
| 2332 | |
| 2333 | memcpy(buffer, &msg, sizeof(msg)); |
| 2334 | memcpy(buffer + sizeof(msg), &reply, sizeof(reply)); |
| 2335 | DBG("[notification-thread] Send command reply (%i)", (int) status); |
| 2336 | |
| 2337 | /* Enqueue buffer to outgoing queue and flush it. */ |
| 2338 | ret = lttng_dynamic_buffer_append( |
| 2339 | &client->communication.outbound.buffer, |
| 2340 | buffer, sizeof(buffer)); |
| 2341 | if (ret) { |
| 2342 | goto error; |
| 2343 | } |
| 2344 | |
| 2345 | ret = client_flush_outgoing_queue(client, state); |
| 2346 | if (ret) { |
| 2347 | goto error; |
| 2348 | } |
| 2349 | |
| 2350 | if (client->communication.outbound.buffer.size != 0) { |
| 2351 | /* Queue could not be emptied. */ |
| 2352 | client->communication.outbound.queued_command_reply = true; |
| 2353 | } |
| 2354 | |
| 2355 | return 0; |
| 2356 | error: |
| 2357 | return -1; |
| 2358 | } |
| 2359 | |
| 2360 | static |
| 2361 | int client_dispatch_message(struct notification_client *client, |
| 2362 | struct notification_thread_state *state) |
| 2363 | { |
| 2364 | int ret = 0; |
| 2365 | |
| 2366 | if (client->communication.inbound.msg_type != |
| 2367 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE && |
| 2368 | client->communication.inbound.msg_type != |
| 2369 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN && |
| 2370 | !client->validated) { |
| 2371 | WARN("[notification-thread] client attempted a command before handshake"); |
| 2372 | ret = -1; |
| 2373 | goto end; |
| 2374 | } |
| 2375 | |
| 2376 | switch (client->communication.inbound.msg_type) { |
| 2377 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN: |
| 2378 | { |
| 2379 | /* |
| 2380 | * Receiving message header. The function will be called again |
| 2381 | * once the rest of the message as been received and can be |
| 2382 | * interpreted. |
| 2383 | */ |
| 2384 | const struct lttng_notification_channel_message *msg; |
| 2385 | |
| 2386 | assert(sizeof(*msg) == |
| 2387 | client->communication.inbound.buffer.size); |
| 2388 | msg = (const struct lttng_notification_channel_message *) |
| 2389 | client->communication.inbound.buffer.data; |
| 2390 | |
| 2391 | if (msg->size == 0 || msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { |
| 2392 | ERR("[notification-thread] Invalid notification channel message: length = %u", msg->size); |
| 2393 | ret = -1; |
| 2394 | goto end; |
| 2395 | } |
| 2396 | |
| 2397 | switch (msg->type) { |
| 2398 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: |
| 2399 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: |
| 2400 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: |
| 2401 | break; |
| 2402 | default: |
| 2403 | ret = -1; |
| 2404 | ERR("[notification-thread] Invalid notification channel message: unexpected message type"); |
| 2405 | goto end; |
| 2406 | } |
| 2407 | |
| 2408 | client->communication.inbound.bytes_to_receive = msg->size; |
| 2409 | client->communication.inbound.msg_type = |
| 2410 | (enum lttng_notification_channel_message_type) msg->type; |
| 2411 | ret = lttng_dynamic_buffer_set_size( |
| 2412 | &client->communication.inbound.buffer, msg->size); |
| 2413 | if (ret) { |
| 2414 | goto end; |
| 2415 | } |
| 2416 | break; |
| 2417 | } |
| 2418 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: |
| 2419 | { |
| 2420 | struct lttng_notification_channel_command_handshake *handshake_client; |
| 2421 | struct lttng_notification_channel_command_handshake handshake_reply = { |
| 2422 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, |
| 2423 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, |
| 2424 | }; |
| 2425 | struct lttng_notification_channel_message msg_header = { |
| 2426 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, |
| 2427 | .size = sizeof(handshake_reply), |
| 2428 | }; |
| 2429 | enum lttng_notification_channel_status status = |
| 2430 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 2431 | char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)]; |
| 2432 | |
| 2433 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); |
| 2434 | memcpy(send_buffer + sizeof(msg_header), &handshake_reply, |
| 2435 | sizeof(handshake_reply)); |
| 2436 | |
| 2437 | handshake_client = |
| 2438 | (struct lttng_notification_channel_command_handshake *) |
| 2439 | client->communication.inbound.buffer.data; |
| 2440 | client->major = handshake_client->major; |
| 2441 | client->minor = handshake_client->minor; |
| 2442 | if (!client->communication.inbound.creds_received) { |
| 2443 | ERR("[notification-thread] No credentials received from client"); |
| 2444 | ret = -1; |
| 2445 | goto end; |
| 2446 | } |
| 2447 | |
| 2448 | client->uid = LTTNG_SOCK_GET_UID_CRED( |
| 2449 | &client->communication.inbound.creds); |
| 2450 | client->gid = LTTNG_SOCK_GET_GID_CRED( |
| 2451 | &client->communication.inbound.creds); |
| 2452 | DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", |
| 2453 | client->uid, client->gid, (int) client->major, |
| 2454 | (int) client->minor); |
| 2455 | |
| 2456 | if (handshake_client->major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { |
| 2457 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION; |
| 2458 | } |
| 2459 | |
| 2460 | ret = lttng_dynamic_buffer_append(&client->communication.outbound.buffer, |
| 2461 | send_buffer, sizeof(send_buffer)); |
| 2462 | if (ret) { |
| 2463 | ERR("[notification-thread] Failed to send protocol version to notification channel client"); |
| 2464 | goto end; |
| 2465 | } |
| 2466 | |
| 2467 | ret = client_flush_outgoing_queue(client, state); |
| 2468 | if (ret) { |
| 2469 | goto end; |
| 2470 | } |
| 2471 | |
| 2472 | ret = client_send_command_reply(client, state, status); |
| 2473 | if (ret) { |
| 2474 | ERR("[notification-thread] Failed to send reply to notification channel client"); |
| 2475 | goto end; |
| 2476 | } |
| 2477 | |
| 2478 | /* Set reception state to receive the next message header. */ |
| 2479 | ret = client_reset_inbound_state(client); |
| 2480 | if (ret) { |
| 2481 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 2482 | goto end; |
| 2483 | } |
| 2484 | client->validated = true; |
| 2485 | break; |
| 2486 | } |
| 2487 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: |
| 2488 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: |
| 2489 | { |
| 2490 | struct lttng_condition *condition; |
| 2491 | enum lttng_notification_channel_status status = |
| 2492 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 2493 | const struct lttng_buffer_view condition_view = |
| 2494 | lttng_buffer_view_from_dynamic_buffer( |
| 2495 | &client->communication.inbound.buffer, |
| 2496 | 0, -1); |
| 2497 | size_t expected_condition_size = |
| 2498 | client->communication.inbound.buffer.size; |
| 2499 | |
| 2500 | ret = lttng_condition_create_from_buffer(&condition_view, |
| 2501 | &condition); |
| 2502 | if (ret != expected_condition_size) { |
| 2503 | ERR("[notification-thread] Malformed condition received from client"); |
| 2504 | goto end; |
| 2505 | } |
| 2506 | |
| 2507 | if (client->communication.inbound.msg_type == |
| 2508 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { |
| 2509 | ret = notification_thread_client_subscribe(client, |
| 2510 | condition, state, &status); |
| 2511 | } else { |
| 2512 | ret = notification_thread_client_unsubscribe(client, |
| 2513 | condition, state, &status); |
| 2514 | } |
| 2515 | if (ret) { |
| 2516 | goto end; |
| 2517 | } |
| 2518 | |
| 2519 | ret = client_send_command_reply(client, state, status); |
| 2520 | if (ret) { |
| 2521 | ERR("[notification-thread] Failed to send reply to notification channel client"); |
| 2522 | goto end; |
| 2523 | } |
| 2524 | |
| 2525 | /* Set reception state to receive the next message header. */ |
| 2526 | ret = client_reset_inbound_state(client); |
| 2527 | if (ret) { |
| 2528 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 2529 | goto end; |
| 2530 | } |
| 2531 | break; |
| 2532 | } |
| 2533 | default: |
| 2534 | abort(); |
| 2535 | } |
| 2536 | end: |
| 2537 | return ret; |
| 2538 | } |
| 2539 | |
| 2540 | /* Incoming data from client. */ |
| 2541 | int handle_notification_thread_client_in( |
| 2542 | struct notification_thread_state *state, int socket) |
| 2543 | { |
| 2544 | int ret = 0; |
| 2545 | struct notification_client *client; |
| 2546 | ssize_t recv_ret; |
| 2547 | size_t offset; |
| 2548 | |
| 2549 | client = get_client_from_socket(socket, state); |
| 2550 | if (!client) { |
| 2551 | /* Internal error, abort. */ |
| 2552 | ret = -1; |
| 2553 | goto end; |
| 2554 | } |
| 2555 | |
| 2556 | offset = client->communication.inbound.buffer.size - |
| 2557 | client->communication.inbound.bytes_to_receive; |
| 2558 | if (client->communication.inbound.expect_creds) { |
| 2559 | recv_ret = lttcomm_recv_creds_unix_sock(socket, |
| 2560 | client->communication.inbound.buffer.data + offset, |
| 2561 | client->communication.inbound.bytes_to_receive, |
| 2562 | &client->communication.inbound.creds); |
| 2563 | if (recv_ret > 0) { |
| 2564 | client->communication.inbound.expect_creds = false; |
| 2565 | client->communication.inbound.creds_received = true; |
| 2566 | } |
| 2567 | } else { |
| 2568 | recv_ret = lttcomm_recv_unix_sock_non_block(socket, |
| 2569 | client->communication.inbound.buffer.data + offset, |
| 2570 | client->communication.inbound.bytes_to_receive); |
| 2571 | } |
| 2572 | if (recv_ret < 0) { |
| 2573 | goto error_disconnect_client; |
| 2574 | } |
| 2575 | |
| 2576 | client->communication.inbound.bytes_to_receive -= recv_ret; |
| 2577 | if (client->communication.inbound.bytes_to_receive == 0) { |
| 2578 | ret = client_dispatch_message(client, state); |
| 2579 | if (ret) { |
| 2580 | /* |
| 2581 | * Only returns an error if this client must be |
| 2582 | * disconnected. |
| 2583 | */ |
| 2584 | goto error_disconnect_client; |
| 2585 | } |
| 2586 | } else { |
| 2587 | goto end; |
| 2588 | } |
| 2589 | end: |
| 2590 | return ret; |
| 2591 | error_disconnect_client: |
| 2592 | ret = handle_notification_thread_client_disconnect(socket, state); |
| 2593 | return ret; |
| 2594 | } |
| 2595 | |
| 2596 | /* Client ready to receive outgoing data. */ |
| 2597 | int handle_notification_thread_client_out( |
| 2598 | struct notification_thread_state *state, int socket) |
| 2599 | { |
| 2600 | int ret; |
| 2601 | struct notification_client *client; |
| 2602 | |
| 2603 | client = get_client_from_socket(socket, state); |
| 2604 | if (!client) { |
| 2605 | /* Internal error, abort. */ |
| 2606 | ret = -1; |
| 2607 | goto end; |
| 2608 | } |
| 2609 | |
| 2610 | ret = client_flush_outgoing_queue(client, state); |
| 2611 | if (ret) { |
| 2612 | goto end; |
| 2613 | } |
| 2614 | end: |
| 2615 | return ret; |
| 2616 | } |
| 2617 | |
| 2618 | static |
| 2619 | bool evaluate_buffer_usage_condition(const struct lttng_condition *condition, |
| 2620 | const struct channel_state_sample *sample, |
| 2621 | uint64_t buffer_capacity) |
| 2622 | { |
| 2623 | bool result = false; |
| 2624 | uint64_t threshold; |
| 2625 | enum lttng_condition_type condition_type; |
| 2626 | const struct lttng_condition_buffer_usage *use_condition = container_of( |
| 2627 | condition, struct lttng_condition_buffer_usage, |
| 2628 | parent); |
| 2629 | |
| 2630 | if (use_condition->threshold_bytes.set) { |
| 2631 | threshold = use_condition->threshold_bytes.value; |
| 2632 | } else { |
| 2633 | /* |
| 2634 | * Threshold was expressed as a ratio. |
| 2635 | * |
| 2636 | * TODO the threshold (in bytes) of conditions expressed |
| 2637 | * as a ratio of total buffer size could be cached to |
| 2638 | * forego this double-multiplication or it could be performed |
| 2639 | * as fixed-point math. |
| 2640 | * |
| 2641 | * Note that caching should accomodate the case where the |
| 2642 | * condition applies to multiple channels (i.e. don't assume |
| 2643 | * that all channels matching my_chann* have the same size...) |
| 2644 | */ |
| 2645 | threshold = (uint64_t) (use_condition->threshold_ratio.value * |
| 2646 | (double) buffer_capacity); |
| 2647 | } |
| 2648 | |
| 2649 | condition_type = lttng_condition_get_type(condition); |
| 2650 | if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) { |
| 2651 | DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, |
| 2652 | threshold, sample->highest_usage); |
| 2653 | |
| 2654 | /* |
| 2655 | * The low condition should only be triggered once _all_ of the |
| 2656 | * streams in a channel have gone below the "low" threshold. |
| 2657 | */ |
| 2658 | if (sample->highest_usage <= threshold) { |
| 2659 | result = true; |
| 2660 | } |
| 2661 | } else { |
| 2662 | DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, |
| 2663 | threshold, sample->highest_usage); |
| 2664 | |
| 2665 | /* |
| 2666 | * For high buffer usage scenarios, we want to trigger whenever |
| 2667 | * _any_ of the streams has reached the "high" threshold. |
| 2668 | */ |
| 2669 | if (sample->highest_usage >= threshold) { |
| 2670 | result = true; |
| 2671 | } |
| 2672 | } |
| 2673 | |
| 2674 | return result; |
| 2675 | } |
| 2676 | |
| 2677 | static |
| 2678 | bool evaluate_session_consumed_size_condition( |
| 2679 | const struct lttng_condition *condition, |
| 2680 | uint64_t session_consumed_size) |
| 2681 | { |
| 2682 | uint64_t threshold; |
| 2683 | const struct lttng_condition_session_consumed_size *size_condition = |
| 2684 | container_of(condition, |
| 2685 | struct lttng_condition_session_consumed_size, |
| 2686 | parent); |
| 2687 | |
| 2688 | threshold = size_condition->consumed_threshold_bytes.value; |
| 2689 | DBG("[notification-thread] Session consumed size condition being evaluated: threshold = %" PRIu64 ", current size = %" PRIu64, |
| 2690 | threshold, session_consumed_size); |
| 2691 | return session_consumed_size >= threshold; |
| 2692 | } |
| 2693 | |
| 2694 | static |
| 2695 | int evaluate_condition(const struct lttng_condition *condition, |
| 2696 | struct lttng_evaluation **evaluation, |
| 2697 | const struct notification_thread_state *state, |
| 2698 | const struct channel_state_sample *previous_sample, |
| 2699 | const struct channel_state_sample *latest_sample, |
| 2700 | uint64_t previous_session_consumed_total, |
| 2701 | uint64_t latest_session_consumed_total, |
| 2702 | struct channel_info *channel_info) |
| 2703 | { |
| 2704 | int ret = 0; |
| 2705 | enum lttng_condition_type condition_type; |
| 2706 | const bool previous_sample_available = !!previous_sample; |
| 2707 | bool previous_sample_result = false; |
| 2708 | bool latest_sample_result; |
| 2709 | |
| 2710 | condition_type = lttng_condition_get_type(condition); |
| 2711 | |
| 2712 | switch (condition_type) { |
| 2713 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 2714 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 2715 | if (caa_likely(previous_sample_available)) { |
| 2716 | previous_sample_result = |
| 2717 | evaluate_buffer_usage_condition(condition, |
| 2718 | previous_sample, channel_info->capacity); |
| 2719 | } |
| 2720 | latest_sample_result = evaluate_buffer_usage_condition( |
| 2721 | condition, latest_sample, |
| 2722 | channel_info->capacity); |
| 2723 | break; |
| 2724 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 2725 | if (caa_likely(previous_sample_available)) { |
| 2726 | previous_sample_result = |
| 2727 | evaluate_session_consumed_size_condition( |
| 2728 | condition, |
| 2729 | previous_session_consumed_total); |
| 2730 | } |
| 2731 | latest_sample_result = |
| 2732 | evaluate_session_consumed_size_condition( |
| 2733 | condition, |
| 2734 | latest_session_consumed_total); |
| 2735 | break; |
| 2736 | default: |
| 2737 | /* Unknown condition type; internal error. */ |
| 2738 | abort(); |
| 2739 | } |
| 2740 | |
| 2741 | if (!latest_sample_result || |
| 2742 | (previous_sample_result == latest_sample_result)) { |
| 2743 | /* |
| 2744 | * Only trigger on a condition evaluation transition. |
| 2745 | * |
| 2746 | * NOTE: This edge-triggered logic may not be appropriate for |
| 2747 | * future condition types. |
| 2748 | */ |
| 2749 | goto end; |
| 2750 | } |
| 2751 | |
| 2752 | if (!evaluation || !latest_sample_result) { |
| 2753 | goto end; |
| 2754 | } |
| 2755 | |
| 2756 | switch (condition_type) { |
| 2757 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 2758 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 2759 | *evaluation = lttng_evaluation_buffer_usage_create( |
| 2760 | condition_type, |
| 2761 | latest_sample->highest_usage, |
| 2762 | channel_info->capacity); |
| 2763 | break; |
| 2764 | case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE: |
| 2765 | *evaluation = lttng_evaluation_session_consumed_size_create( |
| 2766 | latest_session_consumed_total); |
| 2767 | break; |
| 2768 | default: |
| 2769 | abort(); |
| 2770 | } |
| 2771 | |
| 2772 | if (!*evaluation) { |
| 2773 | ret = -1; |
| 2774 | goto end; |
| 2775 | } |
| 2776 | end: |
| 2777 | return ret; |
| 2778 | } |
| 2779 | |
| 2780 | static |
| 2781 | int client_enqueue_dropped_notification(struct notification_client *client, |
| 2782 | struct notification_thread_state *state) |
| 2783 | { |
| 2784 | int ret; |
| 2785 | struct lttng_notification_channel_message msg = { |
| 2786 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED, |
| 2787 | .size = 0, |
| 2788 | }; |
| 2789 | |
| 2790 | ret = lttng_dynamic_buffer_append( |
| 2791 | &client->communication.outbound.buffer, &msg, |
| 2792 | sizeof(msg)); |
| 2793 | return ret; |
| 2794 | } |
| 2795 | |
| 2796 | static |
| 2797 | int send_evaluation_to_clients(const struct lttng_trigger *trigger, |
| 2798 | const struct lttng_evaluation *evaluation, |
| 2799 | struct notification_client_list* client_list, |
| 2800 | struct notification_thread_state *state, |
| 2801 | uid_t channel_uid, gid_t channel_gid) |
| 2802 | { |
| 2803 | int ret = 0; |
| 2804 | struct lttng_dynamic_buffer msg_buffer; |
| 2805 | struct notification_client_list_element *client_list_element, *tmp; |
| 2806 | const struct lttng_notification notification = { |
| 2807 | .condition = (struct lttng_condition *) lttng_trigger_get_const_condition(trigger), |
| 2808 | .evaluation = (struct lttng_evaluation *) evaluation, |
| 2809 | }; |
| 2810 | struct lttng_notification_channel_message msg_header = { |
| 2811 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION, |
| 2812 | }; |
| 2813 | |
| 2814 | lttng_dynamic_buffer_init(&msg_buffer); |
| 2815 | |
| 2816 | ret = lttng_dynamic_buffer_append(&msg_buffer, &msg_header, |
| 2817 | sizeof(msg_header)); |
| 2818 | if (ret) { |
| 2819 | goto end; |
| 2820 | } |
| 2821 | |
| 2822 | ret = lttng_notification_serialize(¬ification, &msg_buffer); |
| 2823 | if (ret) { |
| 2824 | ERR("[notification-thread] Failed to serialize notification"); |
| 2825 | ret = -1; |
| 2826 | goto end; |
| 2827 | } |
| 2828 | |
| 2829 | /* Update payload size. */ |
| 2830 | ((struct lttng_notification_channel_message * ) msg_buffer.data)->size = |
| 2831 | (uint32_t) (msg_buffer.size - sizeof(msg_header)); |
| 2832 | |
| 2833 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 2834 | &client_list->list, node) { |
| 2835 | struct notification_client *client = |
| 2836 | client_list_element->client; |
| 2837 | |
| 2838 | if (client->uid != channel_uid && client->gid != channel_gid && |
| 2839 | client->uid != 0) { |
| 2840 | /* Client is not allowed to monitor this channel. */ |
| 2841 | DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this channel"); |
| 2842 | continue; |
| 2843 | } |
| 2844 | |
| 2845 | DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", |
| 2846 | client->socket, msg_buffer.size); |
| 2847 | if (client->communication.outbound.buffer.size) { |
| 2848 | /* |
| 2849 | * Outgoing data is already buffered for this client; |
| 2850 | * drop the notification and enqueue a "dropped |
| 2851 | * notification" message if this is the first dropped |
| 2852 | * notification since the socket spilled-over to the |
| 2853 | * queue. |
| 2854 | */ |
| 2855 | DBG("[notification-thread] Dropping notification addressed to client (socket fd = %i)", |
| 2856 | client->socket); |
| 2857 | if (!client->communication.outbound.dropped_notification) { |
| 2858 | client->communication.outbound.dropped_notification = true; |
| 2859 | ret = client_enqueue_dropped_notification( |
| 2860 | client, state); |
| 2861 | if (ret) { |
| 2862 | goto end; |
| 2863 | } |
| 2864 | } |
| 2865 | continue; |
| 2866 | } |
| 2867 | |
| 2868 | ret = lttng_dynamic_buffer_append_buffer( |
| 2869 | &client->communication.outbound.buffer, |
| 2870 | &msg_buffer); |
| 2871 | if (ret) { |
| 2872 | goto end; |
| 2873 | } |
| 2874 | |
| 2875 | ret = client_flush_outgoing_queue(client, state); |
| 2876 | if (ret) { |
| 2877 | goto end; |
| 2878 | } |
| 2879 | } |
| 2880 | ret = 0; |
| 2881 | end: |
| 2882 | lttng_dynamic_buffer_reset(&msg_buffer); |
| 2883 | return ret; |
| 2884 | } |
| 2885 | |
| 2886 | int handle_notification_thread_channel_sample( |
| 2887 | struct notification_thread_state *state, int pipe, |
| 2888 | enum lttng_domain_type domain) |
| 2889 | { |
| 2890 | int ret = 0; |
| 2891 | struct lttcomm_consumer_channel_monitor_msg sample_msg; |
| 2892 | struct channel_info *channel_info; |
| 2893 | struct cds_lfht_node *node; |
| 2894 | struct cds_lfht_iter iter; |
| 2895 | struct lttng_channel_trigger_list *trigger_list; |
| 2896 | struct lttng_trigger_list_element *trigger_list_element; |
| 2897 | bool previous_sample_available = false; |
| 2898 | struct channel_state_sample previous_sample, latest_sample; |
| 2899 | uint64_t previous_session_consumed_total, latest_session_consumed_total; |
| 2900 | |
| 2901 | /* |
| 2902 | * The monitoring pipe only holds messages smaller than PIPE_BUF, |
| 2903 | * ensuring that read/write of sampling messages are atomic. |
| 2904 | */ |
| 2905 | ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg)); |
| 2906 | if (ret != sizeof(sample_msg)) { |
| 2907 | ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)", |
| 2908 | pipe); |
| 2909 | ret = -1; |
| 2910 | goto end; |
| 2911 | } |
| 2912 | |
| 2913 | ret = 0; |
| 2914 | latest_sample.key.key = sample_msg.key; |
| 2915 | latest_sample.key.domain = domain; |
| 2916 | latest_sample.highest_usage = sample_msg.highest; |
| 2917 | latest_sample.lowest_usage = sample_msg.lowest; |
| 2918 | latest_sample.channel_total_consumed = sample_msg.total_consumed; |
| 2919 | |
| 2920 | rcu_read_lock(); |
| 2921 | |
| 2922 | /* Retrieve the channel's informations */ |
| 2923 | cds_lfht_lookup(state->channels_ht, |
| 2924 | hash_channel_key(&latest_sample.key), |
| 2925 | match_channel_info, |
| 2926 | &latest_sample.key, |
| 2927 | &iter); |
| 2928 | node = cds_lfht_iter_get_node(&iter); |
| 2929 | if (caa_unlikely(!node)) { |
| 2930 | /* |
| 2931 | * Not an error since the consumer can push a sample to the pipe |
| 2932 | * and the rest of the session daemon could notify us of the |
| 2933 | * channel's destruction before we get a chance to process that |
| 2934 | * sample. |
| 2935 | */ |
| 2936 | DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", |
| 2937 | latest_sample.key.key, |
| 2938 | domain == LTTNG_DOMAIN_KERNEL ? "kernel" : |
| 2939 | "user space"); |
| 2940 | goto end_unlock; |
| 2941 | } |
| 2942 | channel_info = caa_container_of(node, struct channel_info, |
| 2943 | channels_ht_node); |
| 2944 | DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64", total consumed = %" PRIu64")", |
| 2945 | channel_info->name, |
| 2946 | latest_sample.key.key, |
| 2947 | channel_info->session_info->name, |
| 2948 | latest_sample.highest_usage, |
| 2949 | latest_sample.lowest_usage, |
| 2950 | latest_sample.channel_total_consumed); |
| 2951 | |
| 2952 | previous_session_consumed_total = |
| 2953 | channel_info->session_info->consumed_data_size; |
| 2954 | |
| 2955 | /* Retrieve the channel's last sample, if it exists, and update it. */ |
| 2956 | cds_lfht_lookup(state->channel_state_ht, |
| 2957 | hash_channel_key(&latest_sample.key), |
| 2958 | match_channel_state_sample, |
| 2959 | &latest_sample.key, |
| 2960 | &iter); |
| 2961 | node = cds_lfht_iter_get_node(&iter); |
| 2962 | if (caa_likely(node)) { |
| 2963 | struct channel_state_sample *stored_sample; |
| 2964 | |
| 2965 | /* Update the sample stored. */ |
| 2966 | stored_sample = caa_container_of(node, |
| 2967 | struct channel_state_sample, |
| 2968 | channel_state_ht_node); |
| 2969 | |
| 2970 | memcpy(&previous_sample, stored_sample, |
| 2971 | sizeof(previous_sample)); |
| 2972 | stored_sample->highest_usage = latest_sample.highest_usage; |
| 2973 | stored_sample->lowest_usage = latest_sample.lowest_usage; |
| 2974 | stored_sample->channel_total_consumed = latest_sample.channel_total_consumed; |
| 2975 | previous_sample_available = true; |
| 2976 | |
| 2977 | latest_session_consumed_total = |
| 2978 | previous_session_consumed_total + |
| 2979 | (latest_sample.channel_total_consumed - previous_sample.channel_total_consumed); |
| 2980 | } else { |
| 2981 | /* |
| 2982 | * This is the channel's first sample, allocate space for and |
| 2983 | * store the new sample. |
| 2984 | */ |
| 2985 | struct channel_state_sample *stored_sample; |
| 2986 | |
| 2987 | stored_sample = zmalloc(sizeof(*stored_sample)); |
| 2988 | if (!stored_sample) { |
| 2989 | ret = -1; |
| 2990 | goto end_unlock; |
| 2991 | } |
| 2992 | |
| 2993 | memcpy(stored_sample, &latest_sample, sizeof(*stored_sample)); |
| 2994 | cds_lfht_node_init(&stored_sample->channel_state_ht_node); |
| 2995 | cds_lfht_add(state->channel_state_ht, |
| 2996 | hash_channel_key(&stored_sample->key), |
| 2997 | &stored_sample->channel_state_ht_node); |
| 2998 | |
| 2999 | latest_session_consumed_total = |
| 3000 | previous_session_consumed_total + |
| 3001 | latest_sample.channel_total_consumed; |
| 3002 | } |
| 3003 | |
| 3004 | channel_info->session_info->consumed_data_size = |
| 3005 | latest_session_consumed_total; |
| 3006 | |
| 3007 | /* Find triggers associated with this channel. */ |
| 3008 | cds_lfht_lookup(state->channel_triggers_ht, |
| 3009 | hash_channel_key(&latest_sample.key), |
| 3010 | match_channel_trigger_list, |
| 3011 | &latest_sample.key, |
| 3012 | &iter); |
| 3013 | node = cds_lfht_iter_get_node(&iter); |
| 3014 | if (caa_likely(!node)) { |
| 3015 | goto end_unlock; |
| 3016 | } |
| 3017 | |
| 3018 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 3019 | channel_triggers_ht_node); |
| 3020 | cds_list_for_each_entry(trigger_list_element, &trigger_list->list, |
| 3021 | node) { |
| 3022 | const struct lttng_condition *condition; |
| 3023 | const struct lttng_action *action; |
| 3024 | const struct lttng_trigger *trigger; |
| 3025 | struct notification_client_list *client_list; |
| 3026 | struct lttng_evaluation *evaluation = NULL; |
| 3027 | |
| 3028 | trigger = trigger_list_element->trigger; |
| 3029 | condition = lttng_trigger_get_const_condition(trigger); |
| 3030 | assert(condition); |
| 3031 | action = lttng_trigger_get_const_action(trigger); |
| 3032 | |
| 3033 | /* Notify actions are the only type currently supported. */ |
| 3034 | assert(lttng_action_get_type_const(action) == |
| 3035 | LTTNG_ACTION_TYPE_NOTIFY); |
| 3036 | |
| 3037 | /* |
| 3038 | * Check if any client is subscribed to the result of this |
| 3039 | * evaluation. |
| 3040 | */ |
| 3041 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 3042 | lttng_condition_hash(condition), |
| 3043 | match_client_list, |
| 3044 | trigger, |
| 3045 | &iter); |
| 3046 | node = cds_lfht_iter_get_node(&iter); |
| 3047 | assert(node); |
| 3048 | |
| 3049 | client_list = caa_container_of(node, |
| 3050 | struct notification_client_list, |
| 3051 | notification_trigger_ht_node); |
| 3052 | if (cds_list_empty(&client_list->list)) { |
| 3053 | /* |
| 3054 | * No clients interested in the evaluation's result, |
| 3055 | * skip it. |
| 3056 | */ |
| 3057 | continue; |
| 3058 | } |
| 3059 | |
| 3060 | ret = evaluate_condition(condition, &evaluation, state, |
| 3061 | previous_sample_available ? &previous_sample : NULL, |
| 3062 | &latest_sample, |
| 3063 | previous_session_consumed_total, |
| 3064 | latest_session_consumed_total, |
| 3065 | channel_info); |
| 3066 | if (caa_unlikely(ret)) { |
| 3067 | goto end_unlock; |
| 3068 | } |
| 3069 | |
| 3070 | if (caa_likely(!evaluation)) { |
| 3071 | continue; |
| 3072 | } |
| 3073 | |
| 3074 | /* Dispatch evaluation result to all clients. */ |
| 3075 | ret = send_evaluation_to_clients(trigger_list_element->trigger, |
| 3076 | evaluation, client_list, state, |
| 3077 | channel_info->session_info->uid, |
| 3078 | channel_info->session_info->gid); |
| 3079 | lttng_evaluation_destroy(evaluation); |
| 3080 | if (caa_unlikely(ret)) { |
| 3081 | goto end_unlock; |
| 3082 | } |
| 3083 | } |
| 3084 | end_unlock: |
| 3085 | rcu_read_unlock(); |
| 3086 | end: |
| 3087 | return ret; |
| 3088 | } |