| 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.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/notification/channel-internal.h> |
| 36 | |
| 37 | #include <time.h> |
| 38 | #include <unistd.h> |
| 39 | #include <assert.h> |
| 40 | #include <inttypes.h> |
| 41 | #include <fcntl.h> |
| 42 | |
| 43 | #include "notification-thread.h" |
| 44 | #include "notification-thread-events.h" |
| 45 | #include "notification-thread-commands.h" |
| 46 | #include "lttng-sessiond.h" |
| 47 | #include "kernel.h" |
| 48 | |
| 49 | #define CLIENT_POLL_MASK_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP) |
| 50 | #define CLIENT_POLL_MASK_IN_OUT (CLIENT_POLL_MASK_IN | LPOLLOUT) |
| 51 | |
| 52 | struct lttng_trigger_list_element { |
| 53 | struct lttng_trigger *trigger; |
| 54 | struct cds_list_head node; |
| 55 | }; |
| 56 | |
| 57 | struct lttng_channel_trigger_list { |
| 58 | struct channel_key channel_key; |
| 59 | struct cds_list_head list; |
| 60 | struct cds_lfht_node channel_triggers_ht_node; |
| 61 | }; |
| 62 | |
| 63 | struct lttng_trigger_ht_element { |
| 64 | struct lttng_trigger *trigger; |
| 65 | struct cds_lfht_node node; |
| 66 | }; |
| 67 | |
| 68 | struct lttng_condition_list_element { |
| 69 | struct lttng_condition *condition; |
| 70 | struct cds_list_head node; |
| 71 | }; |
| 72 | |
| 73 | struct notification_client_list_element { |
| 74 | struct notification_client *client; |
| 75 | struct cds_list_head node; |
| 76 | }; |
| 77 | |
| 78 | struct notification_client_list { |
| 79 | struct lttng_trigger *trigger; |
| 80 | struct cds_list_head list; |
| 81 | struct cds_lfht_node notification_trigger_ht_node; |
| 82 | }; |
| 83 | |
| 84 | struct notification_client { |
| 85 | int socket; |
| 86 | /* Client protocol version. */ |
| 87 | uint8_t major, minor; |
| 88 | uid_t uid; |
| 89 | gid_t gid; |
| 90 | /* |
| 91 | * Indicates if the credentials and versions of the client have been |
| 92 | * checked. |
| 93 | */ |
| 94 | bool validated; |
| 95 | /* |
| 96 | * Conditions to which the client's notification channel is subscribed. |
| 97 | * List of struct lttng_condition_list_node. The condition member is |
| 98 | * owned by the client. |
| 99 | */ |
| 100 | struct cds_list_head condition_list; |
| 101 | struct cds_lfht_node client_socket_ht_node; |
| 102 | struct { |
| 103 | struct { |
| 104 | /* |
| 105 | * During the reception of a message, the reception |
| 106 | * buffers' "size" is set to contain the current |
| 107 | * message's complete payload. |
| 108 | */ |
| 109 | struct lttng_dynamic_buffer buffer; |
| 110 | /* Bytes left to receive for the current message. */ |
| 111 | size_t bytes_to_receive; |
| 112 | /* Type of the message being received. */ |
| 113 | enum lttng_notification_channel_message_type msg_type; |
| 114 | /* |
| 115 | * Indicates whether or not credentials are expected |
| 116 | * from the client. |
| 117 | */ |
| 118 | bool expect_creds; |
| 119 | /* |
| 120 | * Indicates whether or not credentials were received |
| 121 | * from the client. |
| 122 | */ |
| 123 | bool creds_received; |
| 124 | /* Only used during credentials reception. */ |
| 125 | lttng_sock_cred creds; |
| 126 | } inbound; |
| 127 | struct { |
| 128 | /* |
| 129 | * Indicates whether or not a notification addressed to |
| 130 | * this client was dropped because a command reply was |
| 131 | * already buffered. |
| 132 | * |
| 133 | * A notification is dropped whenever the buffer is not |
| 134 | * empty. |
| 135 | */ |
| 136 | bool dropped_notification; |
| 137 | /* |
| 138 | * Indicates whether or not a command reply is already |
| 139 | * buffered. In this case, it means that the client is |
| 140 | * not consuming command replies before emitting a new |
| 141 | * one. This could be caused by a protocol error or a |
| 142 | * misbehaving/malicious client. |
| 143 | */ |
| 144 | bool queued_command_reply; |
| 145 | struct lttng_dynamic_buffer buffer; |
| 146 | } outbound; |
| 147 | } communication; |
| 148 | }; |
| 149 | |
| 150 | struct channel_state_sample { |
| 151 | struct channel_key key; |
| 152 | struct cds_lfht_node channel_state_ht_node; |
| 153 | uint64_t highest_usage; |
| 154 | uint64_t lowest_usage; |
| 155 | }; |
| 156 | |
| 157 | static unsigned long hash_channel_key(struct channel_key *key); |
| 158 | static int evaluate_condition(struct lttng_condition *condition, |
| 159 | struct lttng_evaluation **evaluation, |
| 160 | struct notification_thread_state *state, |
| 161 | struct channel_state_sample *previous_sample, |
| 162 | struct channel_state_sample *latest_sample, |
| 163 | uint64_t buffer_capacity); |
| 164 | static |
| 165 | int send_evaluation_to_clients(struct lttng_trigger *trigger, |
| 166 | struct lttng_evaluation *evaluation, |
| 167 | struct notification_client_list *client_list, |
| 168 | struct notification_thread_state *state, |
| 169 | uid_t channel_uid, gid_t channel_gid); |
| 170 | |
| 171 | static |
| 172 | int match_client(struct cds_lfht_node *node, const void *key) |
| 173 | { |
| 174 | /* This double-cast is intended to supress pointer-to-cast warning. */ |
| 175 | int socket = (int) (intptr_t) key; |
| 176 | struct notification_client *client; |
| 177 | |
| 178 | client = caa_container_of(node, struct notification_client, |
| 179 | client_socket_ht_node); |
| 180 | |
| 181 | return !!(client->socket == socket); |
| 182 | } |
| 183 | |
| 184 | static |
| 185 | int match_channel_trigger_list(struct cds_lfht_node *node, const void *key) |
| 186 | { |
| 187 | struct channel_key *channel_key = (struct channel_key *) key; |
| 188 | struct lttng_channel_trigger_list *trigger_list; |
| 189 | |
| 190 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 191 | channel_triggers_ht_node); |
| 192 | |
| 193 | return !!((channel_key->key == trigger_list->channel_key.key) && |
| 194 | (channel_key->domain == trigger_list->channel_key.domain)); |
| 195 | } |
| 196 | |
| 197 | static |
| 198 | int match_channel_state_sample(struct cds_lfht_node *node, const void *key) |
| 199 | { |
| 200 | struct channel_key *channel_key = (struct channel_key *) key; |
| 201 | struct channel_state_sample *sample; |
| 202 | |
| 203 | sample = caa_container_of(node, struct channel_state_sample, |
| 204 | channel_state_ht_node); |
| 205 | |
| 206 | return !!((channel_key->key == sample->key.key) && |
| 207 | (channel_key->domain == sample->key.domain)); |
| 208 | } |
| 209 | |
| 210 | static |
| 211 | int match_channel_info(struct cds_lfht_node *node, const void *key) |
| 212 | { |
| 213 | struct channel_key *channel_key = (struct channel_key *) key; |
| 214 | struct channel_info *channel_info; |
| 215 | |
| 216 | channel_info = caa_container_of(node, struct channel_info, |
| 217 | channels_ht_node); |
| 218 | |
| 219 | return !!((channel_key->key == channel_info->key.key) && |
| 220 | (channel_key->domain == channel_info->key.domain)); |
| 221 | } |
| 222 | |
| 223 | static |
| 224 | int match_condition(struct cds_lfht_node *node, const void *key) |
| 225 | { |
| 226 | struct lttng_condition *condition_key = (struct lttng_condition *) key; |
| 227 | struct lttng_trigger_ht_element *trigger; |
| 228 | struct lttng_condition *condition; |
| 229 | |
| 230 | trigger = caa_container_of(node, struct lttng_trigger_ht_element, |
| 231 | node); |
| 232 | condition = lttng_trigger_get_condition(trigger->trigger); |
| 233 | assert(condition); |
| 234 | |
| 235 | return !!lttng_condition_is_equal(condition_key, condition); |
| 236 | } |
| 237 | |
| 238 | static |
| 239 | int match_client_list(struct cds_lfht_node *node, const void *key) |
| 240 | { |
| 241 | struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; |
| 242 | struct notification_client_list *client_list; |
| 243 | struct lttng_condition *condition; |
| 244 | struct lttng_condition *condition_key = lttng_trigger_get_condition( |
| 245 | trigger_key); |
| 246 | |
| 247 | assert(condition_key); |
| 248 | |
| 249 | client_list = caa_container_of(node, struct notification_client_list, |
| 250 | notification_trigger_ht_node); |
| 251 | condition = lttng_trigger_get_condition(client_list->trigger); |
| 252 | |
| 253 | return !!lttng_condition_is_equal(condition_key, condition); |
| 254 | } |
| 255 | |
| 256 | static |
| 257 | int match_client_list_condition(struct cds_lfht_node *node, const void *key) |
| 258 | { |
| 259 | struct lttng_condition *condition_key = (struct lttng_condition *) key; |
| 260 | struct notification_client_list *client_list; |
| 261 | struct lttng_condition *condition; |
| 262 | |
| 263 | assert(condition_key); |
| 264 | |
| 265 | client_list = caa_container_of(node, struct notification_client_list, |
| 266 | notification_trigger_ht_node); |
| 267 | condition = lttng_trigger_get_condition(client_list->trigger); |
| 268 | |
| 269 | return !!lttng_condition_is_equal(condition_key, condition); |
| 270 | } |
| 271 | |
| 272 | static |
| 273 | unsigned long lttng_condition_buffer_usage_hash( |
| 274 | struct lttng_condition *_condition) |
| 275 | { |
| 276 | unsigned long hash = 0; |
| 277 | struct lttng_condition_buffer_usage *condition; |
| 278 | |
| 279 | condition = container_of(_condition, |
| 280 | struct lttng_condition_buffer_usage, parent); |
| 281 | |
| 282 | if (condition->session_name) { |
| 283 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); |
| 284 | } |
| 285 | if (condition->channel_name) { |
| 286 | hash ^= hash_key_str(condition->channel_name, lttng_ht_seed); |
| 287 | } |
| 288 | if (condition->domain.set) { |
| 289 | hash ^= hash_key_ulong( |
| 290 | (void *) condition->domain.type, |
| 291 | lttng_ht_seed); |
| 292 | } |
| 293 | if (condition->threshold_ratio.set) { |
| 294 | uint64_t val; |
| 295 | |
| 296 | val = condition->threshold_ratio.value * (double) UINT32_MAX; |
| 297 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 298 | } else if (condition->threshold_ratio.set) { |
| 299 | uint64_t val; |
| 300 | |
| 301 | val = condition->threshold_bytes.value; |
| 302 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 303 | } |
| 304 | return hash; |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * The lttng_condition hashing code is kept in this file (rather than |
| 309 | * condition.c) since it makes use of GPLv2 code (hashtable utils), which we |
| 310 | * don't want to link in liblttng-ctl. |
| 311 | */ |
| 312 | static |
| 313 | unsigned long lttng_condition_hash(struct lttng_condition *condition) |
| 314 | { |
| 315 | switch (condition->type) { |
| 316 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 317 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 318 | return lttng_condition_buffer_usage_hash(condition); |
| 319 | default: |
| 320 | ERR("[notification-thread] Unexpected condition type caught"); |
| 321 | abort(); |
| 322 | } |
| 323 | } |
| 324 | |
| 325 | static |
| 326 | unsigned long hash_channel_key(struct channel_key *key) |
| 327 | { |
| 328 | unsigned long key_hash = hash_key_u64(&key->key, lttng_ht_seed); |
| 329 | unsigned long domain_hash = hash_key_ulong( |
| 330 | (void *) (unsigned long) key->domain, lttng_ht_seed); |
| 331 | |
| 332 | return key_hash ^ domain_hash; |
| 333 | } |
| 334 | |
| 335 | static |
| 336 | void channel_info_destroy(struct channel_info *channel_info) |
| 337 | { |
| 338 | if (!channel_info) { |
| 339 | return; |
| 340 | } |
| 341 | |
| 342 | if (channel_info->session_name) { |
| 343 | free(channel_info->session_name); |
| 344 | } |
| 345 | if (channel_info->channel_name) { |
| 346 | free(channel_info->channel_name); |
| 347 | } |
| 348 | free(channel_info); |
| 349 | } |
| 350 | |
| 351 | static |
| 352 | struct channel_info *channel_info_copy(struct channel_info *channel_info) |
| 353 | { |
| 354 | struct channel_info *copy = zmalloc(sizeof(*channel_info)); |
| 355 | |
| 356 | assert(channel_info); |
| 357 | assert(channel_info->session_name); |
| 358 | assert(channel_info->channel_name); |
| 359 | |
| 360 | if (!copy) { |
| 361 | goto end; |
| 362 | } |
| 363 | |
| 364 | memcpy(copy, channel_info, sizeof(*channel_info)); |
| 365 | copy->session_name = NULL; |
| 366 | copy->channel_name = NULL; |
| 367 | |
| 368 | copy->session_name = strdup(channel_info->session_name); |
| 369 | if (!copy->session_name) { |
| 370 | goto error; |
| 371 | } |
| 372 | copy->channel_name = strdup(channel_info->channel_name); |
| 373 | if (!copy->channel_name) { |
| 374 | goto error; |
| 375 | } |
| 376 | cds_lfht_node_init(&channel_info->channels_ht_node); |
| 377 | end: |
| 378 | return copy; |
| 379 | error: |
| 380 | channel_info_destroy(copy); |
| 381 | return NULL; |
| 382 | } |
| 383 | |
| 384 | /* This function must be called with the RCU read lock held. */ |
| 385 | static |
| 386 | int evaluate_condition_for_client(struct lttng_trigger *trigger, |
| 387 | struct lttng_condition *condition, |
| 388 | struct notification_client *client, |
| 389 | struct notification_thread_state *state) |
| 390 | { |
| 391 | int ret; |
| 392 | struct cds_lfht_iter iter; |
| 393 | struct cds_lfht_node *node; |
| 394 | struct channel_info *channel_info = NULL; |
| 395 | struct channel_key *channel_key = NULL; |
| 396 | struct channel_state_sample *last_sample = NULL; |
| 397 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
| 398 | struct lttng_evaluation *evaluation = NULL; |
| 399 | struct notification_client_list client_list = { 0 }; |
| 400 | struct notification_client_list_element client_list_element = { 0 }; |
| 401 | |
| 402 | assert(trigger); |
| 403 | assert(condition); |
| 404 | assert(client); |
| 405 | assert(state); |
| 406 | |
| 407 | /* Find the channel associated with the trigger. */ |
| 408 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, |
| 409 | channel_trigger_list , channel_triggers_ht_node) { |
| 410 | struct lttng_trigger_list_element *element; |
| 411 | |
| 412 | cds_list_for_each_entry(element, &channel_trigger_list->list, node) { |
| 413 | struct lttng_condition *current_condition = |
| 414 | lttng_trigger_get_condition( |
| 415 | element->trigger); |
| 416 | |
| 417 | assert(current_condition); |
| 418 | if (!lttng_condition_is_equal(condition, |
| 419 | current_condition)) { |
| 420 | continue; |
| 421 | } |
| 422 | |
| 423 | /* Found the trigger, save the channel key. */ |
| 424 | channel_key = &channel_trigger_list->channel_key; |
| 425 | break; |
| 426 | } |
| 427 | if (channel_key) { |
| 428 | /* The channel key was found stop iteration. */ |
| 429 | break; |
| 430 | } |
| 431 | } |
| 432 | |
| 433 | if (!channel_key){ |
| 434 | /* No channel found; normal exit. */ |
| 435 | DBG("[notification-thread] No channel associated with newly subscribed-to condition"); |
| 436 | ret = 0; |
| 437 | goto end; |
| 438 | } |
| 439 | |
| 440 | /* Fetch channel info for the matching channel. */ |
| 441 | cds_lfht_lookup(state->channels_ht, |
| 442 | hash_channel_key(channel_key), |
| 443 | match_channel_info, |
| 444 | channel_key, |
| 445 | &iter); |
| 446 | node = cds_lfht_iter_get_node(&iter); |
| 447 | assert(node); |
| 448 | channel_info = caa_container_of(node, struct channel_info, |
| 449 | channels_ht_node); |
| 450 | |
| 451 | /* Retrieve the channel's last sample, if it exists. */ |
| 452 | cds_lfht_lookup(state->channel_state_ht, |
| 453 | hash_channel_key(channel_key), |
| 454 | match_channel_state_sample, |
| 455 | channel_key, |
| 456 | &iter); |
| 457 | node = cds_lfht_iter_get_node(&iter); |
| 458 | if (node) { |
| 459 | last_sample = caa_container_of(node, |
| 460 | struct channel_state_sample, |
| 461 | channel_state_ht_node); |
| 462 | } else { |
| 463 | /* Nothing to evaluate, no sample was ever taken. Normal exit */ |
| 464 | DBG("[notification-thread] No channel sample associated with newly subscribed-to condition"); |
| 465 | ret = 0; |
| 466 | goto end; |
| 467 | } |
| 468 | |
| 469 | ret = evaluate_condition(condition, &evaluation, state, NULL, |
| 470 | last_sample, channel_info->capacity); |
| 471 | if (ret) { |
| 472 | WARN("[notification-thread] Fatal error occured while evaluating a newly subscribed-to condition"); |
| 473 | goto end; |
| 474 | } |
| 475 | |
| 476 | if (!evaluation) { |
| 477 | /* Evaluation yielded nothing. Normal exit. */ |
| 478 | DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client"); |
| 479 | ret = 0; |
| 480 | goto end; |
| 481 | } |
| 482 | |
| 483 | /* |
| 484 | * Create a temporary client list with the client currently |
| 485 | * subscribing. |
| 486 | */ |
| 487 | cds_lfht_node_init(&client_list.notification_trigger_ht_node); |
| 488 | CDS_INIT_LIST_HEAD(&client_list.list); |
| 489 | client_list.trigger = trigger; |
| 490 | |
| 491 | CDS_INIT_LIST_HEAD(&client_list_element.node); |
| 492 | client_list_element.client = client; |
| 493 | cds_list_add(&client_list_element.node, &client_list.list); |
| 494 | |
| 495 | /* Send evaluation result to the newly-subscribed client. */ |
| 496 | DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client"); |
| 497 | ret = send_evaluation_to_clients(trigger, evaluation, &client_list, |
| 498 | state, channel_info->uid, channel_info->gid); |
| 499 | |
| 500 | end: |
| 501 | return ret; |
| 502 | } |
| 503 | |
| 504 | static |
| 505 | int notification_thread_client_subscribe(struct notification_client *client, |
| 506 | struct lttng_condition *condition, |
| 507 | struct notification_thread_state *state, |
| 508 | enum lttng_notification_channel_status *_status) |
| 509 | { |
| 510 | int ret = 0; |
| 511 | struct cds_lfht_iter iter; |
| 512 | struct cds_lfht_node *node; |
| 513 | struct notification_client_list *client_list; |
| 514 | struct lttng_condition_list_element *condition_list_element = NULL; |
| 515 | struct notification_client_list_element *client_list_element = NULL; |
| 516 | enum lttng_notification_channel_status status = |
| 517 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 518 | |
| 519 | /* |
| 520 | * Ensure that the client has not already subscribed to this condition |
| 521 | * before. |
| 522 | */ |
| 523 | cds_list_for_each_entry(condition_list_element, &client->condition_list, node) { |
| 524 | if (lttng_condition_is_equal(condition_list_element->condition, |
| 525 | condition)) { |
| 526 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED; |
| 527 | goto end; |
| 528 | } |
| 529 | } |
| 530 | |
| 531 | condition_list_element = zmalloc(sizeof(*condition_list_element)); |
| 532 | if (!condition_list_element) { |
| 533 | ret = -1; |
| 534 | goto error; |
| 535 | } |
| 536 | client_list_element = zmalloc(sizeof(*client_list_element)); |
| 537 | if (!client_list_element) { |
| 538 | ret = -1; |
| 539 | goto error; |
| 540 | } |
| 541 | |
| 542 | rcu_read_lock(); |
| 543 | |
| 544 | /* |
| 545 | * Add the newly-subscribed condition to the client's subscription list. |
| 546 | */ |
| 547 | CDS_INIT_LIST_HEAD(&condition_list_element->node); |
| 548 | condition_list_element->condition = condition; |
| 549 | cds_list_add(&condition_list_element->node, &client->condition_list); |
| 550 | |
| 551 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 552 | lttng_condition_hash(condition), |
| 553 | match_client_list_condition, |
| 554 | condition, |
| 555 | &iter); |
| 556 | node = cds_lfht_iter_get_node(&iter); |
| 557 | if (!node) { |
| 558 | free(client_list_element); |
| 559 | goto end_unlock; |
| 560 | } |
| 561 | |
| 562 | client_list = caa_container_of(node, struct notification_client_list, |
| 563 | notification_trigger_ht_node); |
| 564 | if (evaluate_condition_for_client(client_list->trigger, condition, |
| 565 | client, state)) { |
| 566 | WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); |
| 567 | ret = -1; |
| 568 | goto end_unlock; |
| 569 | } |
| 570 | |
| 571 | /* |
| 572 | * Add the client to the list of clients interested in a given trigger |
| 573 | * if a "notification" trigger with a corresponding condition was |
| 574 | * added prior. |
| 575 | */ |
| 576 | client_list_element->client = client; |
| 577 | CDS_INIT_LIST_HEAD(&client_list_element->node); |
| 578 | cds_list_add(&client_list_element->node, &client_list->list); |
| 579 | end_unlock: |
| 580 | rcu_read_unlock(); |
| 581 | end: |
| 582 | if (_status) { |
| 583 | *_status = status; |
| 584 | } |
| 585 | return ret; |
| 586 | error: |
| 587 | free(condition_list_element); |
| 588 | free(client_list_element); |
| 589 | return ret; |
| 590 | } |
| 591 | |
| 592 | static |
| 593 | int notification_thread_client_unsubscribe( |
| 594 | struct notification_client *client, |
| 595 | struct lttng_condition *condition, |
| 596 | struct notification_thread_state *state, |
| 597 | enum lttng_notification_channel_status *_status) |
| 598 | { |
| 599 | struct cds_lfht_iter iter; |
| 600 | struct cds_lfht_node *node; |
| 601 | struct notification_client_list *client_list; |
| 602 | struct lttng_condition_list_element *condition_list_element, |
| 603 | *condition_tmp; |
| 604 | struct notification_client_list_element *client_list_element, |
| 605 | *client_tmp; |
| 606 | bool condition_found = false; |
| 607 | enum lttng_notification_channel_status status = |
| 608 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 609 | |
| 610 | /* Remove the condition from the client's condition list. */ |
| 611 | cds_list_for_each_entry_safe(condition_list_element, condition_tmp, |
| 612 | &client->condition_list, node) { |
| 613 | if (!lttng_condition_is_equal(condition_list_element->condition, |
| 614 | condition)) { |
| 615 | continue; |
| 616 | } |
| 617 | |
| 618 | cds_list_del(&condition_list_element->node); |
| 619 | /* |
| 620 | * The caller may be iterating on the client's conditions to |
| 621 | * tear down a client's connection. In this case, the condition |
| 622 | * will be destroyed at the end. |
| 623 | */ |
| 624 | if (condition != condition_list_element->condition) { |
| 625 | lttng_condition_destroy( |
| 626 | condition_list_element->condition); |
| 627 | } |
| 628 | free(condition_list_element); |
| 629 | condition_found = true; |
| 630 | break; |
| 631 | } |
| 632 | |
| 633 | if (!condition_found) { |
| 634 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION; |
| 635 | goto end; |
| 636 | } |
| 637 | |
| 638 | /* |
| 639 | * Remove the client from the list of clients interested the trigger |
| 640 | * matching the condition. |
| 641 | */ |
| 642 | rcu_read_lock(); |
| 643 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 644 | lttng_condition_hash(condition), |
| 645 | match_client_list_condition, |
| 646 | condition, |
| 647 | &iter); |
| 648 | node = cds_lfht_iter_get_node(&iter); |
| 649 | if (!node) { |
| 650 | goto end_unlock; |
| 651 | } |
| 652 | |
| 653 | client_list = caa_container_of(node, struct notification_client_list, |
| 654 | notification_trigger_ht_node); |
| 655 | cds_list_for_each_entry_safe(client_list_element, client_tmp, |
| 656 | &client_list->list, node) { |
| 657 | if (client_list_element->client->socket != client->socket) { |
| 658 | continue; |
| 659 | } |
| 660 | cds_list_del(&client_list_element->node); |
| 661 | free(client_list_element); |
| 662 | break; |
| 663 | } |
| 664 | end_unlock: |
| 665 | rcu_read_unlock(); |
| 666 | end: |
| 667 | lttng_condition_destroy(condition); |
| 668 | if (_status) { |
| 669 | *_status = status; |
| 670 | } |
| 671 | return 0; |
| 672 | } |
| 673 | |
| 674 | static |
| 675 | void notification_client_destroy(struct notification_client *client, |
| 676 | struct notification_thread_state *state) |
| 677 | { |
| 678 | struct lttng_condition_list_element *condition_list_element, *tmp; |
| 679 | |
| 680 | if (!client) { |
| 681 | return; |
| 682 | } |
| 683 | |
| 684 | /* Release all conditions to which the client was subscribed. */ |
| 685 | cds_list_for_each_entry_safe(condition_list_element, tmp, |
| 686 | &client->condition_list, node) { |
| 687 | (void) notification_thread_client_unsubscribe(client, |
| 688 | condition_list_element->condition, state, NULL); |
| 689 | } |
| 690 | |
| 691 | if (client->socket >= 0) { |
| 692 | (void) lttcomm_close_unix_sock(client->socket); |
| 693 | } |
| 694 | lttng_dynamic_buffer_reset(&client->communication.inbound.buffer); |
| 695 | lttng_dynamic_buffer_reset(&client->communication.outbound.buffer); |
| 696 | free(client); |
| 697 | } |
| 698 | |
| 699 | /* |
| 700 | * Call with rcu_read_lock held (and hold for the lifetime of the returned |
| 701 | * client pointer). |
| 702 | */ |
| 703 | static |
| 704 | struct notification_client *get_client_from_socket(int socket, |
| 705 | struct notification_thread_state *state) |
| 706 | { |
| 707 | struct cds_lfht_iter iter; |
| 708 | struct cds_lfht_node *node; |
| 709 | struct notification_client *client = NULL; |
| 710 | |
| 711 | cds_lfht_lookup(state->client_socket_ht, |
| 712 | hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed), |
| 713 | match_client, |
| 714 | (void *) (unsigned long) socket, |
| 715 | &iter); |
| 716 | node = cds_lfht_iter_get_node(&iter); |
| 717 | if (!node) { |
| 718 | goto end; |
| 719 | } |
| 720 | |
| 721 | client = caa_container_of(node, struct notification_client, |
| 722 | client_socket_ht_node); |
| 723 | end: |
| 724 | return client; |
| 725 | } |
| 726 | |
| 727 | static |
| 728 | bool trigger_applies_to_channel(struct lttng_trigger *trigger, |
| 729 | struct channel_info *info) |
| 730 | { |
| 731 | enum lttng_condition_status status; |
| 732 | struct lttng_condition *condition; |
| 733 | const char *trigger_session_name = NULL; |
| 734 | const char *trigger_channel_name = NULL; |
| 735 | enum lttng_domain_type trigger_domain; |
| 736 | |
| 737 | condition = lttng_trigger_get_condition(trigger); |
| 738 | if (!condition) { |
| 739 | goto fail; |
| 740 | } |
| 741 | |
| 742 | switch (lttng_condition_get_type(condition)) { |
| 743 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 744 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 745 | break; |
| 746 | default: |
| 747 | goto fail; |
| 748 | } |
| 749 | |
| 750 | status = lttng_condition_buffer_usage_get_domain_type(condition, |
| 751 | &trigger_domain); |
| 752 | assert(status == LTTNG_CONDITION_STATUS_OK); |
| 753 | if (info->key.domain != trigger_domain) { |
| 754 | goto fail; |
| 755 | } |
| 756 | |
| 757 | status = lttng_condition_buffer_usage_get_session_name( |
| 758 | condition, &trigger_session_name); |
| 759 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_session_name); |
| 760 | |
| 761 | status = lttng_condition_buffer_usage_get_channel_name( |
| 762 | condition, &trigger_channel_name); |
| 763 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_channel_name); |
| 764 | |
| 765 | if (strcmp(info->session_name, trigger_session_name)) { |
| 766 | goto fail; |
| 767 | } |
| 768 | if (strcmp(info->channel_name, trigger_channel_name)) { |
| 769 | goto fail; |
| 770 | } |
| 771 | |
| 772 | return true; |
| 773 | fail: |
| 774 | return false; |
| 775 | } |
| 776 | |
| 777 | static |
| 778 | bool trigger_applies_to_client(struct lttng_trigger *trigger, |
| 779 | struct notification_client *client) |
| 780 | { |
| 781 | bool applies = false; |
| 782 | struct lttng_condition_list_element *condition_list_element; |
| 783 | |
| 784 | cds_list_for_each_entry(condition_list_element, &client->condition_list, |
| 785 | node) { |
| 786 | applies = lttng_condition_is_equal( |
| 787 | condition_list_element->condition, |
| 788 | lttng_trigger_get_condition(trigger)); |
| 789 | if (applies) { |
| 790 | break; |
| 791 | } |
| 792 | } |
| 793 | return applies; |
| 794 | } |
| 795 | |
| 796 | static |
| 797 | int handle_notification_thread_command_add_channel( |
| 798 | struct notification_thread_state *state, |
| 799 | struct channel_info *channel_info, |
| 800 | enum lttng_error_code *cmd_result) |
| 801 | { |
| 802 | struct cds_list_head trigger_list; |
| 803 | struct channel_info *new_channel_info; |
| 804 | struct channel_key *channel_key; |
| 805 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
| 806 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 807 | int trigger_count = 0; |
| 808 | struct cds_lfht_iter iter; |
| 809 | |
| 810 | DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", |
| 811 | channel_info->channel_name, channel_info->session_name, |
| 812 | channel_info->key.key, channel_info->key.domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); |
| 813 | |
| 814 | CDS_INIT_LIST_HEAD(&trigger_list); |
| 815 | |
| 816 | new_channel_info = channel_info_copy(channel_info); |
| 817 | if (!new_channel_info) { |
| 818 | goto error; |
| 819 | } |
| 820 | |
| 821 | channel_key = &new_channel_info->key; |
| 822 | |
| 823 | /* Build a list of all triggers applying to the new channel. */ |
| 824 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 825 | node) { |
| 826 | struct lttng_trigger_list_element *new_element; |
| 827 | |
| 828 | if (!trigger_applies_to_channel(trigger_ht_element->trigger, |
| 829 | channel_info)) { |
| 830 | continue; |
| 831 | } |
| 832 | |
| 833 | new_element = zmalloc(sizeof(*new_element)); |
| 834 | if (!new_element) { |
| 835 | goto error; |
| 836 | } |
| 837 | CDS_INIT_LIST_HEAD(&new_element->node); |
| 838 | new_element->trigger = trigger_ht_element->trigger; |
| 839 | cds_list_add(&new_element->node, &trigger_list); |
| 840 | trigger_count++; |
| 841 | } |
| 842 | |
| 843 | DBG("[notification-thread] Found %i triggers that apply to newly added channel", |
| 844 | trigger_count); |
| 845 | channel_trigger_list = zmalloc(sizeof(*channel_trigger_list)); |
| 846 | if (!channel_trigger_list) { |
| 847 | goto error; |
| 848 | } |
| 849 | channel_trigger_list->channel_key = *channel_key; |
| 850 | CDS_INIT_LIST_HEAD(&channel_trigger_list->list); |
| 851 | cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node); |
| 852 | cds_list_splice(&trigger_list, &channel_trigger_list->list); |
| 853 | |
| 854 | rcu_read_lock(); |
| 855 | /* Add channel to the channel_ht which owns the channel_infos. */ |
| 856 | cds_lfht_add(state->channels_ht, |
| 857 | hash_channel_key(channel_key), |
| 858 | &new_channel_info->channels_ht_node); |
| 859 | /* |
| 860 | * Add the list of triggers associated with this channel to the |
| 861 | * channel_triggers_ht. |
| 862 | */ |
| 863 | cds_lfht_add(state->channel_triggers_ht, |
| 864 | hash_channel_key(channel_key), |
| 865 | &channel_trigger_list->channel_triggers_ht_node); |
| 866 | rcu_read_unlock(); |
| 867 | *cmd_result = LTTNG_OK; |
| 868 | return 0; |
| 869 | error: |
| 870 | /* Empty trigger list */ |
| 871 | channel_info_destroy(new_channel_info); |
| 872 | return 1; |
| 873 | } |
| 874 | |
| 875 | static |
| 876 | int handle_notification_thread_command_remove_channel( |
| 877 | struct notification_thread_state *state, |
| 878 | uint64_t channel_key, enum lttng_domain_type domain, |
| 879 | enum lttng_error_code *cmd_result) |
| 880 | { |
| 881 | struct cds_lfht_node *node; |
| 882 | struct cds_lfht_iter iter; |
| 883 | struct lttng_channel_trigger_list *trigger_list; |
| 884 | struct lttng_trigger_list_element *trigger_list_element, *tmp; |
| 885 | struct channel_key key = { .key = channel_key, .domain = domain }; |
| 886 | struct channel_info *channel_info; |
| 887 | |
| 888 | DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", |
| 889 | channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); |
| 890 | |
| 891 | rcu_read_lock(); |
| 892 | |
| 893 | cds_lfht_lookup(state->channel_triggers_ht, |
| 894 | hash_channel_key(&key), |
| 895 | match_channel_trigger_list, |
| 896 | &key, |
| 897 | &iter); |
| 898 | node = cds_lfht_iter_get_node(&iter); |
| 899 | /* |
| 900 | * There is a severe internal error if we are being asked to remove a |
| 901 | * channel that doesn't exist. |
| 902 | */ |
| 903 | if (!node) { |
| 904 | ERR("[notification-thread] Channel being removed is unknown to the notification thread"); |
| 905 | goto end; |
| 906 | } |
| 907 | |
| 908 | /* Free the list of triggers associated with this channel. */ |
| 909 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 910 | channel_triggers_ht_node); |
| 911 | cds_list_for_each_entry_safe(trigger_list_element, tmp, |
| 912 | &trigger_list->list, node) { |
| 913 | cds_list_del(&trigger_list_element->node); |
| 914 | free(trigger_list_element); |
| 915 | } |
| 916 | cds_lfht_del(state->channel_triggers_ht, node); |
| 917 | free(trigger_list); |
| 918 | |
| 919 | /* Free sampled channel state. */ |
| 920 | cds_lfht_lookup(state->channel_state_ht, |
| 921 | hash_channel_key(&key), |
| 922 | match_channel_state_sample, |
| 923 | &key, |
| 924 | &iter); |
| 925 | node = cds_lfht_iter_get_node(&iter); |
| 926 | /* |
| 927 | * This is expected to be NULL if the channel is destroyed before we |
| 928 | * received a sample. |
| 929 | */ |
| 930 | if (node) { |
| 931 | struct channel_state_sample *sample = caa_container_of(node, |
| 932 | struct channel_state_sample, |
| 933 | channel_state_ht_node); |
| 934 | |
| 935 | cds_lfht_del(state->channel_state_ht, node); |
| 936 | free(sample); |
| 937 | } |
| 938 | |
| 939 | /* Remove the channel from the channels_ht and free it. */ |
| 940 | cds_lfht_lookup(state->channels_ht, |
| 941 | hash_channel_key(&key), |
| 942 | match_channel_info, |
| 943 | &key, |
| 944 | &iter); |
| 945 | node = cds_lfht_iter_get_node(&iter); |
| 946 | assert(node); |
| 947 | channel_info = caa_container_of(node, struct channel_info, |
| 948 | channels_ht_node); |
| 949 | cds_lfht_del(state->channels_ht, node); |
| 950 | channel_info_destroy(channel_info); |
| 951 | end: |
| 952 | rcu_read_unlock(); |
| 953 | *cmd_result = LTTNG_OK; |
| 954 | return 0; |
| 955 | } |
| 956 | |
| 957 | static |
| 958 | int condition_is_supported(struct lttng_condition *condition) |
| 959 | { |
| 960 | int ret; |
| 961 | |
| 962 | switch (lttng_condition_get_type(condition)) { |
| 963 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 964 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 965 | { |
| 966 | enum lttng_domain_type domain; |
| 967 | |
| 968 | ret = lttng_condition_buffer_usage_get_domain_type(condition, |
| 969 | &domain); |
| 970 | if (ret) { |
| 971 | ret = -1; |
| 972 | goto end; |
| 973 | } |
| 974 | |
| 975 | if (domain != LTTNG_DOMAIN_KERNEL) { |
| 976 | ret = 1; |
| 977 | goto end; |
| 978 | } |
| 979 | |
| 980 | /* |
| 981 | * Older kernel tracers don't expose the API to monitor their |
| 982 | * buffers. Therefore, we reject triggers that require that |
| 983 | * mechanism to be available to be evaluated. |
| 984 | */ |
| 985 | ret = kernel_supports_ring_buffer_snapshot_sample_positions( |
| 986 | kernel_tracer_fd); |
| 987 | break; |
| 988 | } |
| 989 | default: |
| 990 | ret = 1; |
| 991 | } |
| 992 | end: |
| 993 | return ret; |
| 994 | } |
| 995 | |
| 996 | /* |
| 997 | * FIXME A client's credentials are not checked when registering a trigger, nor |
| 998 | * are they stored alongside with the trigger. |
| 999 | * |
| 1000 | * The effects of this are benign since: |
| 1001 | * - The client will succeed in registering the trigger, as it is valid, |
| 1002 | * - The trigger will, internally, be bound to the channel, |
| 1003 | * - The notifications will not be sent since the client's credentials |
| 1004 | * are checked against the channel at that moment. |
| 1005 | * |
| 1006 | * If this function returns a non-zero value, it means something is |
| 1007 | * fundamentally and the whole subsystem/thread will be torn down. |
| 1008 | * |
| 1009 | * If a non-fatal error occurs, just set the cmd_result to the appropriate |
| 1010 | * error code. |
| 1011 | */ |
| 1012 | static |
| 1013 | int handle_notification_thread_command_register_trigger( |
| 1014 | struct notification_thread_state *state, |
| 1015 | struct lttng_trigger *trigger, |
| 1016 | enum lttng_error_code *cmd_result) |
| 1017 | { |
| 1018 | int ret = 0; |
| 1019 | struct lttng_condition *condition; |
| 1020 | struct notification_client *client; |
| 1021 | struct notification_client_list *client_list = NULL; |
| 1022 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1023 | struct notification_client_list_element *client_list_element, *tmp; |
| 1024 | struct cds_lfht_node *node; |
| 1025 | struct cds_lfht_iter iter; |
| 1026 | struct channel_info *channel; |
| 1027 | bool free_trigger = true; |
| 1028 | |
| 1029 | rcu_read_lock(); |
| 1030 | |
| 1031 | condition = lttng_trigger_get_condition(trigger); |
| 1032 | assert(condition); |
| 1033 | |
| 1034 | ret = condition_is_supported(condition); |
| 1035 | if (ret < 0) { |
| 1036 | goto error; |
| 1037 | } else if (ret == 0) { |
| 1038 | *cmd_result = LTTNG_ERR_NOT_SUPPORTED; |
| 1039 | goto error; |
| 1040 | } else { |
| 1041 | /* Feature is supported, continue. */ |
| 1042 | ret = 0; |
| 1043 | } |
| 1044 | |
| 1045 | trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); |
| 1046 | if (!trigger_ht_element) { |
| 1047 | ret = -1; |
| 1048 | goto error; |
| 1049 | } |
| 1050 | |
| 1051 | /* Add trigger to the trigger_ht. */ |
| 1052 | cds_lfht_node_init(&trigger_ht_element->node); |
| 1053 | trigger_ht_element->trigger = trigger; |
| 1054 | |
| 1055 | node = cds_lfht_add_unique(state->triggers_ht, |
| 1056 | lttng_condition_hash(condition), |
| 1057 | match_condition, |
| 1058 | condition, |
| 1059 | &trigger_ht_element->node); |
| 1060 | if (node != &trigger_ht_element->node) { |
| 1061 | /* Not a fatal error, simply report it to the client. */ |
| 1062 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; |
| 1063 | goto error_free_ht_element; |
| 1064 | } |
| 1065 | |
| 1066 | /* |
| 1067 | * Ownership of the trigger and of its wrapper was transfered to |
| 1068 | * the triggers_ht. |
| 1069 | */ |
| 1070 | trigger_ht_element = NULL; |
| 1071 | free_trigger = false; |
| 1072 | |
| 1073 | /* |
| 1074 | * The rest only applies to triggers that have a "notify" action. |
| 1075 | * It is not skipped as this is the only action type currently |
| 1076 | * supported. |
| 1077 | */ |
| 1078 | client_list = zmalloc(sizeof(*client_list)); |
| 1079 | if (!client_list) { |
| 1080 | ret = -1; |
| 1081 | goto error_free_ht_element; |
| 1082 | } |
| 1083 | cds_lfht_node_init(&client_list->notification_trigger_ht_node); |
| 1084 | CDS_INIT_LIST_HEAD(&client_list->list); |
| 1085 | client_list->trigger = trigger; |
| 1086 | |
| 1087 | /* Build a list of clients to which this new trigger applies. */ |
| 1088 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, |
| 1089 | client_socket_ht_node) { |
| 1090 | if (!trigger_applies_to_client(trigger, client)) { |
| 1091 | continue; |
| 1092 | } |
| 1093 | |
| 1094 | client_list_element = zmalloc(sizeof(*client_list_element)); |
| 1095 | if (!client_list_element) { |
| 1096 | ret = -1; |
| 1097 | goto error_free_client_list; |
| 1098 | } |
| 1099 | CDS_INIT_LIST_HEAD(&client_list_element->node); |
| 1100 | client_list_element->client = client; |
| 1101 | cds_list_add(&client_list_element->node, &client_list->list); |
| 1102 | } |
| 1103 | |
| 1104 | cds_lfht_add(state->notification_trigger_clients_ht, |
| 1105 | lttng_condition_hash(condition), |
| 1106 | &client_list->notification_trigger_ht_node); |
| 1107 | /* |
| 1108 | * Client list ownership transferred to the |
| 1109 | * notification_trigger_clients_ht. |
| 1110 | */ |
| 1111 | client_list = NULL; |
| 1112 | |
| 1113 | /* |
| 1114 | * Add the trigger to list of triggers bound to the channels currently |
| 1115 | * known. |
| 1116 | */ |
| 1117 | cds_lfht_for_each_entry(state->channels_ht, &iter, channel, |
| 1118 | channels_ht_node) { |
| 1119 | struct lttng_trigger_list_element *trigger_list_element; |
| 1120 | struct lttng_channel_trigger_list *trigger_list; |
| 1121 | |
| 1122 | if (!trigger_applies_to_channel(trigger, channel)) { |
| 1123 | continue; |
| 1124 | } |
| 1125 | |
| 1126 | cds_lfht_lookup(state->channel_triggers_ht, |
| 1127 | hash_channel_key(&channel->key), |
| 1128 | match_channel_trigger_list, |
| 1129 | &channel->key, |
| 1130 | &iter); |
| 1131 | node = cds_lfht_iter_get_node(&iter); |
| 1132 | assert(node); |
| 1133 | trigger_list = caa_container_of(node, |
| 1134 | struct lttng_channel_trigger_list, |
| 1135 | channel_triggers_ht_node); |
| 1136 | |
| 1137 | trigger_list_element = zmalloc(sizeof(*trigger_list_element)); |
| 1138 | if (!trigger_list_element) { |
| 1139 | ret = -1; |
| 1140 | goto error_free_client_list; |
| 1141 | } |
| 1142 | CDS_INIT_LIST_HEAD(&trigger_list_element->node); |
| 1143 | trigger_list_element->trigger = trigger; |
| 1144 | cds_list_add(&trigger_list_element->node, &trigger_list->list); |
| 1145 | |
| 1146 | /* A trigger can only apply to one channel. */ |
| 1147 | break; |
| 1148 | } |
| 1149 | |
| 1150 | *cmd_result = LTTNG_OK; |
| 1151 | error_free_client_list: |
| 1152 | if (client_list) { |
| 1153 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 1154 | &client_list->list, node) { |
| 1155 | free(client_list_element); |
| 1156 | } |
| 1157 | free(client_list); |
| 1158 | } |
| 1159 | error_free_ht_element: |
| 1160 | free(trigger_ht_element); |
| 1161 | error: |
| 1162 | if (free_trigger) { |
| 1163 | struct lttng_action *action = lttng_trigger_get_action(trigger); |
| 1164 | |
| 1165 | lttng_condition_destroy(condition); |
| 1166 | lttng_action_destroy(action); |
| 1167 | lttng_trigger_destroy(trigger); |
| 1168 | } |
| 1169 | rcu_read_unlock(); |
| 1170 | return ret; |
| 1171 | } |
| 1172 | |
| 1173 | static |
| 1174 | int handle_notification_thread_command_unregister_trigger( |
| 1175 | struct notification_thread_state *state, |
| 1176 | struct lttng_trigger *trigger, |
| 1177 | enum lttng_error_code *_cmd_reply) |
| 1178 | { |
| 1179 | struct cds_lfht_iter iter; |
| 1180 | struct cds_lfht_node *node, *triggers_ht_node; |
| 1181 | struct lttng_channel_trigger_list *trigger_list; |
| 1182 | struct notification_client_list *client_list; |
| 1183 | struct notification_client_list_element *client_list_element, *tmp; |
| 1184 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1185 | struct lttng_condition *condition = lttng_trigger_get_condition( |
| 1186 | trigger); |
| 1187 | struct lttng_action *action; |
| 1188 | enum lttng_error_code cmd_reply; |
| 1189 | |
| 1190 | rcu_read_lock(); |
| 1191 | |
| 1192 | cds_lfht_lookup(state->triggers_ht, |
| 1193 | lttng_condition_hash(condition), |
| 1194 | match_condition, |
| 1195 | condition, |
| 1196 | &iter); |
| 1197 | triggers_ht_node = cds_lfht_iter_get_node(&iter); |
| 1198 | if (!triggers_ht_node) { |
| 1199 | cmd_reply = LTTNG_ERR_TRIGGER_NOT_FOUND; |
| 1200 | goto end; |
| 1201 | } else { |
| 1202 | cmd_reply = LTTNG_OK; |
| 1203 | } |
| 1204 | |
| 1205 | /* Remove trigger from channel_triggers_ht. */ |
| 1206 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list, |
| 1207 | channel_triggers_ht_node) { |
| 1208 | struct lttng_trigger_list_element *trigger_element, *tmp; |
| 1209 | |
| 1210 | cds_list_for_each_entry_safe(trigger_element, tmp, |
| 1211 | &trigger_list->list, node) { |
| 1212 | struct lttng_condition *current_condition = |
| 1213 | lttng_trigger_get_condition( |
| 1214 | trigger_element->trigger); |
| 1215 | |
| 1216 | assert(current_condition); |
| 1217 | if (!lttng_condition_is_equal(condition, |
| 1218 | current_condition)) { |
| 1219 | continue; |
| 1220 | } |
| 1221 | |
| 1222 | DBG("[notification-thread] Removed trigger from channel_triggers_ht"); |
| 1223 | cds_list_del(&trigger_element->node); |
| 1224 | /* A trigger can only appear once per channel */ |
| 1225 | break; |
| 1226 | } |
| 1227 | } |
| 1228 | |
| 1229 | /* |
| 1230 | * Remove and release the client list from |
| 1231 | * notification_trigger_clients_ht. |
| 1232 | */ |
| 1233 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 1234 | lttng_condition_hash(condition), |
| 1235 | match_client_list, |
| 1236 | trigger, |
| 1237 | &iter); |
| 1238 | node = cds_lfht_iter_get_node(&iter); |
| 1239 | assert(node); |
| 1240 | client_list = caa_container_of(node, struct notification_client_list, |
| 1241 | notification_trigger_ht_node); |
| 1242 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 1243 | &client_list->list, node) { |
| 1244 | free(client_list_element); |
| 1245 | } |
| 1246 | cds_lfht_del(state->notification_trigger_clients_ht, node); |
| 1247 | free(client_list); |
| 1248 | |
| 1249 | /* Remove trigger from triggers_ht. */ |
| 1250 | trigger_ht_element = caa_container_of(triggers_ht_node, |
| 1251 | struct lttng_trigger_ht_element, node); |
| 1252 | cds_lfht_del(state->triggers_ht, triggers_ht_node); |
| 1253 | |
| 1254 | condition = lttng_trigger_get_condition(trigger_ht_element->trigger); |
| 1255 | lttng_condition_destroy(condition); |
| 1256 | action = lttng_trigger_get_action(trigger_ht_element->trigger); |
| 1257 | lttng_action_destroy(action); |
| 1258 | lttng_trigger_destroy(trigger_ht_element->trigger); |
| 1259 | free(trigger_ht_element); |
| 1260 | end: |
| 1261 | rcu_read_unlock(); |
| 1262 | if (_cmd_reply) { |
| 1263 | *_cmd_reply = cmd_reply; |
| 1264 | } |
| 1265 | return 0; |
| 1266 | } |
| 1267 | |
| 1268 | /* Returns 0 on success, 1 on exit requested, negative value on error. */ |
| 1269 | int handle_notification_thread_command( |
| 1270 | struct notification_thread_handle *handle, |
| 1271 | struct notification_thread_state *state) |
| 1272 | { |
| 1273 | int ret; |
| 1274 | uint64_t counter; |
| 1275 | struct notification_thread_command *cmd; |
| 1276 | |
| 1277 | /* Read event_fd to put it back into a quiescent state. */ |
| 1278 | ret = read(handle->cmd_queue.event_fd, &counter, sizeof(counter)); |
| 1279 | if (ret == -1) { |
| 1280 | goto error; |
| 1281 | } |
| 1282 | |
| 1283 | pthread_mutex_lock(&handle->cmd_queue.lock); |
| 1284 | cmd = cds_list_first_entry(&handle->cmd_queue.list, |
| 1285 | struct notification_thread_command, cmd_list_node); |
| 1286 | switch (cmd->type) { |
| 1287 | case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: |
| 1288 | DBG("[notification-thread] Received register trigger command"); |
| 1289 | ret = handle_notification_thread_command_register_trigger( |
| 1290 | state, cmd->parameters.trigger, |
| 1291 | &cmd->reply_code); |
| 1292 | break; |
| 1293 | case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: |
| 1294 | DBG("[notification-thread] Received unregister trigger command"); |
| 1295 | ret = handle_notification_thread_command_unregister_trigger( |
| 1296 | state, cmd->parameters.trigger, |
| 1297 | &cmd->reply_code); |
| 1298 | break; |
| 1299 | case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: |
| 1300 | DBG("[notification-thread] Received add channel command"); |
| 1301 | ret = handle_notification_thread_command_add_channel( |
| 1302 | state, &cmd->parameters.add_channel, |
| 1303 | &cmd->reply_code); |
| 1304 | break; |
| 1305 | case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: |
| 1306 | DBG("[notification-thread] Received remove channel command"); |
| 1307 | ret = handle_notification_thread_command_remove_channel( |
| 1308 | state, cmd->parameters.remove_channel.key, |
| 1309 | cmd->parameters.remove_channel.domain, |
| 1310 | &cmd->reply_code); |
| 1311 | break; |
| 1312 | case NOTIFICATION_COMMAND_TYPE_QUIT: |
| 1313 | DBG("[notification-thread] Received quit command"); |
| 1314 | cmd->reply_code = LTTNG_OK; |
| 1315 | ret = 1; |
| 1316 | goto end; |
| 1317 | default: |
| 1318 | ERR("[notification-thread] Unknown internal command received"); |
| 1319 | goto error_unlock; |
| 1320 | } |
| 1321 | |
| 1322 | if (ret) { |
| 1323 | goto error_unlock; |
| 1324 | } |
| 1325 | end: |
| 1326 | cds_list_del(&cmd->cmd_list_node); |
| 1327 | lttng_waiter_wake_up(&cmd->reply_waiter); |
| 1328 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
| 1329 | return ret; |
| 1330 | error_unlock: |
| 1331 | /* Wake-up and return a fatal error to the calling thread. */ |
| 1332 | lttng_waiter_wake_up(&cmd->reply_waiter); |
| 1333 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
| 1334 | cmd->reply_code = LTTNG_ERR_FATAL; |
| 1335 | error: |
| 1336 | /* Indicate a fatal error to the caller. */ |
| 1337 | return -1; |
| 1338 | } |
| 1339 | |
| 1340 | static |
| 1341 | unsigned long hash_client_socket(int socket) |
| 1342 | { |
| 1343 | return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed); |
| 1344 | } |
| 1345 | |
| 1346 | static |
| 1347 | int socket_set_non_blocking(int socket) |
| 1348 | { |
| 1349 | int ret, flags; |
| 1350 | |
| 1351 | /* Set the pipe as non-blocking. */ |
| 1352 | ret = fcntl(socket, F_GETFL, 0); |
| 1353 | if (ret == -1) { |
| 1354 | PERROR("fcntl get socket flags"); |
| 1355 | goto end; |
| 1356 | } |
| 1357 | flags = ret; |
| 1358 | |
| 1359 | ret = fcntl(socket, F_SETFL, flags | O_NONBLOCK); |
| 1360 | if (ret == -1) { |
| 1361 | PERROR("fcntl set O_NONBLOCK socket flag"); |
| 1362 | goto end; |
| 1363 | } |
| 1364 | DBG("Client socket (fd = %i) set as non-blocking", socket); |
| 1365 | end: |
| 1366 | return ret; |
| 1367 | } |
| 1368 | |
| 1369 | static |
| 1370 | int client_reset_inbound_state(struct notification_client *client) |
| 1371 | { |
| 1372 | int ret; |
| 1373 | |
| 1374 | ret = lttng_dynamic_buffer_set_size( |
| 1375 | &client->communication.inbound.buffer, 0); |
| 1376 | assert(!ret); |
| 1377 | |
| 1378 | client->communication.inbound.bytes_to_receive = |
| 1379 | sizeof(struct lttng_notification_channel_message); |
| 1380 | client->communication.inbound.msg_type = |
| 1381 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN; |
| 1382 | LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1); |
| 1383 | LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1); |
| 1384 | ret = lttng_dynamic_buffer_set_size( |
| 1385 | &client->communication.inbound.buffer, |
| 1386 | client->communication.inbound.bytes_to_receive); |
| 1387 | return ret; |
| 1388 | } |
| 1389 | |
| 1390 | int handle_notification_thread_client_connect( |
| 1391 | struct notification_thread_state *state) |
| 1392 | { |
| 1393 | int ret; |
| 1394 | struct notification_client *client; |
| 1395 | |
| 1396 | DBG("[notification-thread] Handling new notification channel client connection"); |
| 1397 | |
| 1398 | client = zmalloc(sizeof(*client)); |
| 1399 | if (!client) { |
| 1400 | /* Fatal error. */ |
| 1401 | ret = -1; |
| 1402 | goto error; |
| 1403 | } |
| 1404 | CDS_INIT_LIST_HEAD(&client->condition_list); |
| 1405 | lttng_dynamic_buffer_init(&client->communication.inbound.buffer); |
| 1406 | lttng_dynamic_buffer_init(&client->communication.outbound.buffer); |
| 1407 | client->communication.inbound.expect_creds = true; |
| 1408 | ret = client_reset_inbound_state(client); |
| 1409 | if (ret) { |
| 1410 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 1411 | ret = 0; |
| 1412 | goto error; |
| 1413 | } |
| 1414 | |
| 1415 | ret = lttcomm_accept_unix_sock(state->notification_channel_socket); |
| 1416 | if (ret < 0) { |
| 1417 | ERR("[notification-thread] Failed to accept new notification channel client connection"); |
| 1418 | ret = 0; |
| 1419 | goto error; |
| 1420 | } |
| 1421 | |
| 1422 | client->socket = ret; |
| 1423 | |
| 1424 | ret = socket_set_non_blocking(client->socket); |
| 1425 | if (ret) { |
| 1426 | ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking"); |
| 1427 | goto error; |
| 1428 | } |
| 1429 | |
| 1430 | ret = lttcomm_setsockopt_creds_unix_sock(client->socket); |
| 1431 | if (ret < 0) { |
| 1432 | ERR("[notification-thread] Failed to set socket options on new notification channel client socket"); |
| 1433 | ret = 0; |
| 1434 | goto error; |
| 1435 | } |
| 1436 | |
| 1437 | ret = lttng_poll_add(&state->events, client->socket, |
| 1438 | LPOLLIN | LPOLLERR | |
| 1439 | LPOLLHUP | LPOLLRDHUP); |
| 1440 | if (ret < 0) { |
| 1441 | ERR("[notification-thread] Failed to add notification channel client socket to poll set"); |
| 1442 | ret = 0; |
| 1443 | goto error; |
| 1444 | } |
| 1445 | DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", |
| 1446 | client->socket); |
| 1447 | |
| 1448 | rcu_read_lock(); |
| 1449 | cds_lfht_add(state->client_socket_ht, |
| 1450 | hash_client_socket(client->socket), |
| 1451 | &client->client_socket_ht_node); |
| 1452 | rcu_read_unlock(); |
| 1453 | |
| 1454 | return ret; |
| 1455 | error: |
| 1456 | notification_client_destroy(client, state); |
| 1457 | return ret; |
| 1458 | } |
| 1459 | |
| 1460 | int handle_notification_thread_client_disconnect( |
| 1461 | int client_socket, |
| 1462 | struct notification_thread_state *state) |
| 1463 | { |
| 1464 | int ret = 0; |
| 1465 | struct notification_client *client; |
| 1466 | |
| 1467 | rcu_read_lock(); |
| 1468 | DBG("[notification-thread] Closing client connection (socket fd = %i)", |
| 1469 | client_socket); |
| 1470 | client = get_client_from_socket(client_socket, state); |
| 1471 | if (!client) { |
| 1472 | /* Internal state corruption, fatal error. */ |
| 1473 | ERR("[notification-thread] Unable to find client (socket fd = %i)", |
| 1474 | client_socket); |
| 1475 | ret = -1; |
| 1476 | goto end; |
| 1477 | } |
| 1478 | |
| 1479 | ret = lttng_poll_del(&state->events, client_socket); |
| 1480 | if (ret) { |
| 1481 | ERR("[notification-thread] Failed to remove client socket from poll set"); |
| 1482 | } |
| 1483 | cds_lfht_del(state->client_socket_ht, |
| 1484 | &client->client_socket_ht_node); |
| 1485 | notification_client_destroy(client, state); |
| 1486 | end: |
| 1487 | rcu_read_unlock(); |
| 1488 | return ret; |
| 1489 | } |
| 1490 | |
| 1491 | int handle_notification_thread_client_disconnect_all( |
| 1492 | struct notification_thread_state *state) |
| 1493 | { |
| 1494 | struct cds_lfht_iter iter; |
| 1495 | struct notification_client *client; |
| 1496 | bool error_encoutered = false; |
| 1497 | |
| 1498 | rcu_read_lock(); |
| 1499 | DBG("[notification-thread] Closing all client connections"); |
| 1500 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, |
| 1501 | client_socket_ht_node) { |
| 1502 | int ret; |
| 1503 | |
| 1504 | ret = handle_notification_thread_client_disconnect( |
| 1505 | client->socket, state); |
| 1506 | if (ret) { |
| 1507 | error_encoutered = true; |
| 1508 | } |
| 1509 | } |
| 1510 | rcu_read_unlock(); |
| 1511 | return error_encoutered ? 1 : 0; |
| 1512 | } |
| 1513 | |
| 1514 | int handle_notification_thread_trigger_unregister_all( |
| 1515 | struct notification_thread_state *state) |
| 1516 | { |
| 1517 | bool error_occurred = false; |
| 1518 | struct cds_lfht_iter iter; |
| 1519 | struct lttng_trigger_ht_element *trigger_ht_element; |
| 1520 | |
| 1521 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 1522 | node) { |
| 1523 | int ret = handle_notification_thread_command_unregister_trigger( |
| 1524 | state, trigger_ht_element->trigger, NULL); |
| 1525 | if (ret) { |
| 1526 | error_occurred = true; |
| 1527 | } |
| 1528 | } |
| 1529 | return error_occurred ? -1 : 0; |
| 1530 | } |
| 1531 | |
| 1532 | static |
| 1533 | int client_flush_outgoing_queue(struct notification_client *client, |
| 1534 | struct notification_thread_state *state) |
| 1535 | { |
| 1536 | ssize_t ret; |
| 1537 | size_t to_send_count; |
| 1538 | |
| 1539 | assert(client->communication.outbound.buffer.size != 0); |
| 1540 | to_send_count = client->communication.outbound.buffer.size; |
| 1541 | DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", |
| 1542 | client->socket); |
| 1543 | |
| 1544 | ret = lttcomm_send_unix_sock_non_block(client->socket, |
| 1545 | client->communication.outbound.buffer.data, |
| 1546 | to_send_count); |
| 1547 | if ((ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) || |
| 1548 | (ret > 0 && ret < to_send_count)) { |
| 1549 | DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", |
| 1550 | client->socket); |
| 1551 | to_send_count -= max(ret, 0); |
| 1552 | |
| 1553 | memcpy(client->communication.outbound.buffer.data, |
| 1554 | client->communication.outbound.buffer.data + |
| 1555 | client->communication.outbound.buffer.size - to_send_count, |
| 1556 | to_send_count); |
| 1557 | ret = lttng_dynamic_buffer_set_size( |
| 1558 | &client->communication.outbound.buffer, |
| 1559 | to_send_count); |
| 1560 | if (ret) { |
| 1561 | goto error; |
| 1562 | } |
| 1563 | |
| 1564 | /* |
| 1565 | * We want to be notified whenever there is buffer space |
| 1566 | * available to send the rest of the payload. |
| 1567 | */ |
| 1568 | ret = lttng_poll_mod(&state->events, client->socket, |
| 1569 | CLIENT_POLL_MASK_IN_OUT); |
| 1570 | if (ret) { |
| 1571 | goto error; |
| 1572 | } |
| 1573 | } else if (ret < 0) { |
| 1574 | /* Generic error, disconnect the client. */ |
| 1575 | ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)", |
| 1576 | client->socket); |
| 1577 | ret = handle_notification_thread_client_disconnect( |
| 1578 | client->socket, state); |
| 1579 | if (ret) { |
| 1580 | goto error; |
| 1581 | } |
| 1582 | } else { |
| 1583 | /* No error and flushed the queue completely. */ |
| 1584 | ret = lttng_dynamic_buffer_set_size( |
| 1585 | &client->communication.outbound.buffer, 0); |
| 1586 | if (ret) { |
| 1587 | goto error; |
| 1588 | } |
| 1589 | ret = lttng_poll_mod(&state->events, client->socket, |
| 1590 | CLIENT_POLL_MASK_IN); |
| 1591 | if (ret) { |
| 1592 | goto error; |
| 1593 | } |
| 1594 | |
| 1595 | client->communication.outbound.queued_command_reply = false; |
| 1596 | client->communication.outbound.dropped_notification = false; |
| 1597 | } |
| 1598 | |
| 1599 | return 0; |
| 1600 | error: |
| 1601 | return -1; |
| 1602 | } |
| 1603 | |
| 1604 | static |
| 1605 | int client_send_command_reply(struct notification_client *client, |
| 1606 | struct notification_thread_state *state, |
| 1607 | enum lttng_notification_channel_status status) |
| 1608 | { |
| 1609 | int ret; |
| 1610 | struct lttng_notification_channel_command_reply reply = { |
| 1611 | .status = (int8_t) status, |
| 1612 | }; |
| 1613 | struct lttng_notification_channel_message msg = { |
| 1614 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY, |
| 1615 | .size = sizeof(reply), |
| 1616 | }; |
| 1617 | char buffer[sizeof(msg) + sizeof(reply)]; |
| 1618 | |
| 1619 | if (client->communication.outbound.queued_command_reply) { |
| 1620 | /* Protocol error. */ |
| 1621 | goto error; |
| 1622 | } |
| 1623 | |
| 1624 | memcpy(buffer, &msg, sizeof(msg)); |
| 1625 | memcpy(buffer + sizeof(msg), &reply, sizeof(reply)); |
| 1626 | DBG("[notification-thread] Send command reply (%i)", (int) status); |
| 1627 | |
| 1628 | /* Enqueue buffer to outgoing queue and flush it. */ |
| 1629 | ret = lttng_dynamic_buffer_append( |
| 1630 | &client->communication.outbound.buffer, |
| 1631 | buffer, sizeof(buffer)); |
| 1632 | if (ret) { |
| 1633 | goto error; |
| 1634 | } |
| 1635 | |
| 1636 | ret = client_flush_outgoing_queue(client, state); |
| 1637 | if (ret) { |
| 1638 | goto error; |
| 1639 | } |
| 1640 | |
| 1641 | if (client->communication.outbound.buffer.size != 0) { |
| 1642 | /* Queue could not be emptied. */ |
| 1643 | client->communication.outbound.queued_command_reply = true; |
| 1644 | } |
| 1645 | |
| 1646 | return 0; |
| 1647 | error: |
| 1648 | return -1; |
| 1649 | } |
| 1650 | |
| 1651 | static |
| 1652 | int client_dispatch_message(struct notification_client *client, |
| 1653 | struct notification_thread_state *state) |
| 1654 | { |
| 1655 | int ret = 0; |
| 1656 | |
| 1657 | if (client->communication.inbound.msg_type != |
| 1658 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE && |
| 1659 | client->communication.inbound.msg_type != |
| 1660 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN && |
| 1661 | !client->validated) { |
| 1662 | WARN("[notification-thread] client attempted a command before handshake"); |
| 1663 | ret = -1; |
| 1664 | goto end; |
| 1665 | } |
| 1666 | |
| 1667 | switch (client->communication.inbound.msg_type) { |
| 1668 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN: |
| 1669 | { |
| 1670 | /* |
| 1671 | * Receiving message header. The function will be called again |
| 1672 | * once the rest of the message as been received and can be |
| 1673 | * interpreted. |
| 1674 | */ |
| 1675 | const struct lttng_notification_channel_message *msg; |
| 1676 | |
| 1677 | assert(sizeof(*msg) == |
| 1678 | client->communication.inbound.buffer.size); |
| 1679 | msg = (const struct lttng_notification_channel_message *) |
| 1680 | client->communication.inbound.buffer.data; |
| 1681 | |
| 1682 | if (msg->size == 0 || msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { |
| 1683 | ERR("[notification-thread] Invalid notification channel message: length = %u", msg->size); |
| 1684 | ret = -1; |
| 1685 | goto end; |
| 1686 | } |
| 1687 | |
| 1688 | switch (msg->type) { |
| 1689 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: |
| 1690 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: |
| 1691 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: |
| 1692 | break; |
| 1693 | default: |
| 1694 | ret = -1; |
| 1695 | ERR("[notification-thread] Invalid notification channel message: unexpected message type"); |
| 1696 | goto end; |
| 1697 | } |
| 1698 | |
| 1699 | client->communication.inbound.bytes_to_receive = msg->size; |
| 1700 | client->communication.inbound.msg_type = |
| 1701 | (enum lttng_notification_channel_message_type) msg->type; |
| 1702 | ret = lttng_dynamic_buffer_set_size( |
| 1703 | &client->communication.inbound.buffer, msg->size); |
| 1704 | if (ret) { |
| 1705 | goto end; |
| 1706 | } |
| 1707 | break; |
| 1708 | } |
| 1709 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: |
| 1710 | { |
| 1711 | struct lttng_notification_channel_command_handshake *handshake_client; |
| 1712 | struct lttng_notification_channel_command_handshake handshake_reply = { |
| 1713 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, |
| 1714 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, |
| 1715 | }; |
| 1716 | struct lttng_notification_channel_message msg_header = { |
| 1717 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, |
| 1718 | .size = sizeof(handshake_reply), |
| 1719 | }; |
| 1720 | enum lttng_notification_channel_status status = |
| 1721 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 1722 | char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)]; |
| 1723 | |
| 1724 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); |
| 1725 | memcpy(send_buffer + sizeof(msg_header), &handshake_reply, |
| 1726 | sizeof(handshake_reply)); |
| 1727 | |
| 1728 | handshake_client = |
| 1729 | (struct lttng_notification_channel_command_handshake *) |
| 1730 | client->communication.inbound.buffer.data; |
| 1731 | client->major = handshake_client->major; |
| 1732 | client->minor = handshake_client->minor; |
| 1733 | if (!client->communication.inbound.creds_received) { |
| 1734 | ERR("[notification-thread] No credentials received from client"); |
| 1735 | ret = -1; |
| 1736 | goto end; |
| 1737 | } |
| 1738 | |
| 1739 | client->uid = LTTNG_SOCK_GET_UID_CRED( |
| 1740 | &client->communication.inbound.creds); |
| 1741 | client->gid = LTTNG_SOCK_GET_GID_CRED( |
| 1742 | &client->communication.inbound.creds); |
| 1743 | DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", |
| 1744 | client->uid, client->gid, (int) client->major, |
| 1745 | (int) client->minor); |
| 1746 | |
| 1747 | if (handshake_client->major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { |
| 1748 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION; |
| 1749 | } |
| 1750 | |
| 1751 | ret = lttng_dynamic_buffer_append(&client->communication.outbound.buffer, |
| 1752 | send_buffer, sizeof(send_buffer)); |
| 1753 | if (ret) { |
| 1754 | ERR("[notification-thread] Failed to send protocol version to notification channel client"); |
| 1755 | goto end; |
| 1756 | } |
| 1757 | |
| 1758 | ret = client_flush_outgoing_queue(client, state); |
| 1759 | if (ret) { |
| 1760 | goto end; |
| 1761 | } |
| 1762 | |
| 1763 | ret = client_send_command_reply(client, state, status); |
| 1764 | if (ret) { |
| 1765 | ERR("[notification-thread] Failed to send reply to notification channel client"); |
| 1766 | goto end; |
| 1767 | } |
| 1768 | |
| 1769 | /* Set reception state to receive the next message header. */ |
| 1770 | ret = client_reset_inbound_state(client); |
| 1771 | if (ret) { |
| 1772 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 1773 | goto end; |
| 1774 | } |
| 1775 | client->validated = true; |
| 1776 | break; |
| 1777 | } |
| 1778 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: |
| 1779 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: |
| 1780 | { |
| 1781 | struct lttng_condition *condition; |
| 1782 | enum lttng_notification_channel_status status = |
| 1783 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 1784 | const struct lttng_buffer_view condition_view = |
| 1785 | lttng_buffer_view_from_dynamic_buffer( |
| 1786 | &client->communication.inbound.buffer, |
| 1787 | 0, -1); |
| 1788 | size_t expected_condition_size = |
| 1789 | client->communication.inbound.buffer.size; |
| 1790 | |
| 1791 | ret = lttng_condition_create_from_buffer(&condition_view, |
| 1792 | &condition); |
| 1793 | if (ret != expected_condition_size) { |
| 1794 | ERR("[notification-thread] Malformed condition received from client"); |
| 1795 | goto end; |
| 1796 | } |
| 1797 | |
| 1798 | if (client->communication.inbound.msg_type == |
| 1799 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { |
| 1800 | /* |
| 1801 | * FIXME The current state should be evaluated on |
| 1802 | * subscription. |
| 1803 | */ |
| 1804 | ret = notification_thread_client_subscribe(client, |
| 1805 | condition, state, &status); |
| 1806 | } else { |
| 1807 | ret = notification_thread_client_unsubscribe(client, |
| 1808 | condition, state, &status); |
| 1809 | } |
| 1810 | if (ret) { |
| 1811 | goto end; |
| 1812 | } |
| 1813 | |
| 1814 | ret = client_send_command_reply(client, state, status); |
| 1815 | if (ret) { |
| 1816 | ERR("[notification-thread] Failed to send reply to notification channel client"); |
| 1817 | goto end; |
| 1818 | } |
| 1819 | |
| 1820 | /* Set reception state to receive the next message header. */ |
| 1821 | ret = client_reset_inbound_state(client); |
| 1822 | if (ret) { |
| 1823 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 1824 | goto end; |
| 1825 | } |
| 1826 | break; |
| 1827 | } |
| 1828 | default: |
| 1829 | abort(); |
| 1830 | } |
| 1831 | end: |
| 1832 | return ret; |
| 1833 | } |
| 1834 | |
| 1835 | /* Incoming data from client. */ |
| 1836 | int handle_notification_thread_client_in( |
| 1837 | struct notification_thread_state *state, int socket) |
| 1838 | { |
| 1839 | int ret = 0; |
| 1840 | struct notification_client *client; |
| 1841 | ssize_t recv_ret; |
| 1842 | size_t offset; |
| 1843 | |
| 1844 | client = get_client_from_socket(socket, state); |
| 1845 | if (!client) { |
| 1846 | /* Internal error, abort. */ |
| 1847 | ret = -1; |
| 1848 | goto end; |
| 1849 | } |
| 1850 | |
| 1851 | offset = client->communication.inbound.buffer.size - |
| 1852 | client->communication.inbound.bytes_to_receive; |
| 1853 | if (client->communication.inbound.expect_creds) { |
| 1854 | recv_ret = lttcomm_recv_creds_unix_sock(socket, |
| 1855 | client->communication.inbound.buffer.data + offset, |
| 1856 | client->communication.inbound.bytes_to_receive, |
| 1857 | &client->communication.inbound.creds); |
| 1858 | if (recv_ret > 0) { |
| 1859 | client->communication.inbound.expect_creds = false; |
| 1860 | client->communication.inbound.creds_received = true; |
| 1861 | } |
| 1862 | } else { |
| 1863 | recv_ret = lttcomm_recv_unix_sock_non_block(socket, |
| 1864 | client->communication.inbound.buffer.data + offset, |
| 1865 | client->communication.inbound.bytes_to_receive); |
| 1866 | } |
| 1867 | if (recv_ret < 0) { |
| 1868 | goto error_disconnect_client; |
| 1869 | } |
| 1870 | |
| 1871 | client->communication.inbound.bytes_to_receive -= recv_ret; |
| 1872 | if (client->communication.inbound.bytes_to_receive == 0) { |
| 1873 | ret = client_dispatch_message(client, state); |
| 1874 | if (ret) { |
| 1875 | /* |
| 1876 | * Only returns an error if this client must be |
| 1877 | * disconnected. |
| 1878 | */ |
| 1879 | goto error_disconnect_client; |
| 1880 | } |
| 1881 | } else { |
| 1882 | goto end; |
| 1883 | } |
| 1884 | end: |
| 1885 | return ret; |
| 1886 | error_disconnect_client: |
| 1887 | ret = handle_notification_thread_client_disconnect(socket, state); |
| 1888 | return ret; |
| 1889 | } |
| 1890 | |
| 1891 | /* Client ready to receive outgoing data. */ |
| 1892 | int handle_notification_thread_client_out( |
| 1893 | struct notification_thread_state *state, int socket) |
| 1894 | { |
| 1895 | int ret; |
| 1896 | struct notification_client *client; |
| 1897 | |
| 1898 | client = get_client_from_socket(socket, state); |
| 1899 | if (!client) { |
| 1900 | /* Internal error, abort. */ |
| 1901 | ret = -1; |
| 1902 | goto end; |
| 1903 | } |
| 1904 | |
| 1905 | ret = client_flush_outgoing_queue(client, state); |
| 1906 | if (ret) { |
| 1907 | goto end; |
| 1908 | } |
| 1909 | end: |
| 1910 | return ret; |
| 1911 | } |
| 1912 | |
| 1913 | static |
| 1914 | bool evaluate_buffer_usage_condition(struct lttng_condition *condition, |
| 1915 | struct channel_state_sample *sample, uint64_t buffer_capacity) |
| 1916 | { |
| 1917 | bool result = false; |
| 1918 | uint64_t threshold; |
| 1919 | enum lttng_condition_type condition_type; |
| 1920 | struct lttng_condition_buffer_usage *use_condition = container_of( |
| 1921 | condition, struct lttng_condition_buffer_usage, |
| 1922 | parent); |
| 1923 | |
| 1924 | if (!sample) { |
| 1925 | goto end; |
| 1926 | } |
| 1927 | |
| 1928 | if (use_condition->threshold_bytes.set) { |
| 1929 | threshold = use_condition->threshold_bytes.value; |
| 1930 | } else { |
| 1931 | /* |
| 1932 | * Threshold was expressed as a ratio. |
| 1933 | * |
| 1934 | * TODO the threshold (in bytes) of conditions expressed |
| 1935 | * as a ratio of total buffer size could be cached to |
| 1936 | * forego this double-multiplication or it could be performed |
| 1937 | * as fixed-point math. |
| 1938 | * |
| 1939 | * Note that caching should accomodate the case where the |
| 1940 | * condition applies to multiple channels (i.e. don't assume |
| 1941 | * that all channels matching my_chann* have the same size...) |
| 1942 | */ |
| 1943 | threshold = (uint64_t) (use_condition->threshold_ratio.value * |
| 1944 | (double) buffer_capacity); |
| 1945 | } |
| 1946 | |
| 1947 | condition_type = lttng_condition_get_type(condition); |
| 1948 | if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) { |
| 1949 | DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, |
| 1950 | threshold, sample->highest_usage); |
| 1951 | |
| 1952 | /* |
| 1953 | * The low condition should only be triggered once _all_ of the |
| 1954 | * streams in a channel have gone below the "low" threshold. |
| 1955 | */ |
| 1956 | if (sample->highest_usage <= threshold) { |
| 1957 | result = true; |
| 1958 | } |
| 1959 | } else { |
| 1960 | DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, |
| 1961 | threshold, sample->highest_usage); |
| 1962 | |
| 1963 | /* |
| 1964 | * For high buffer usage scenarios, we want to trigger whenever |
| 1965 | * _any_ of the streams has reached the "high" threshold. |
| 1966 | */ |
| 1967 | if (sample->highest_usage >= threshold) { |
| 1968 | result = true; |
| 1969 | } |
| 1970 | } |
| 1971 | end: |
| 1972 | return result; |
| 1973 | } |
| 1974 | |
| 1975 | static |
| 1976 | int evaluate_condition(struct lttng_condition *condition, |
| 1977 | struct lttng_evaluation **evaluation, |
| 1978 | struct notification_thread_state *state, |
| 1979 | struct channel_state_sample *previous_sample, |
| 1980 | struct channel_state_sample *latest_sample, |
| 1981 | uint64_t buffer_capacity) |
| 1982 | { |
| 1983 | int ret = 0; |
| 1984 | enum lttng_condition_type condition_type; |
| 1985 | bool previous_sample_result; |
| 1986 | bool latest_sample_result; |
| 1987 | |
| 1988 | condition_type = lttng_condition_get_type(condition); |
| 1989 | /* No other condition type supported for the moment. */ |
| 1990 | assert(condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW || |
| 1991 | condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH); |
| 1992 | |
| 1993 | previous_sample_result = evaluate_buffer_usage_condition(condition, |
| 1994 | previous_sample, buffer_capacity); |
| 1995 | latest_sample_result = evaluate_buffer_usage_condition(condition, |
| 1996 | latest_sample, buffer_capacity); |
| 1997 | |
| 1998 | if (!latest_sample_result || |
| 1999 | (previous_sample_result == latest_sample_result)) { |
| 2000 | /* |
| 2001 | * Only trigger on a condition evaluation transition. |
| 2002 | * |
| 2003 | * NOTE: This edge-triggered logic may not be appropriate for |
| 2004 | * future condition types. |
| 2005 | */ |
| 2006 | goto end; |
| 2007 | } |
| 2008 | |
| 2009 | if (evaluation && latest_sample_result) { |
| 2010 | *evaluation = lttng_evaluation_buffer_usage_create( |
| 2011 | condition_type, |
| 2012 | latest_sample->highest_usage, |
| 2013 | buffer_capacity); |
| 2014 | if (!*evaluation) { |
| 2015 | ret = -1; |
| 2016 | goto end; |
| 2017 | } |
| 2018 | } |
| 2019 | end: |
| 2020 | return ret; |
| 2021 | } |
| 2022 | |
| 2023 | static |
| 2024 | int client_enqueue_dropped_notification(struct notification_client *client, |
| 2025 | struct notification_thread_state *state) |
| 2026 | { |
| 2027 | int ret; |
| 2028 | struct lttng_notification_channel_message msg = { |
| 2029 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED, |
| 2030 | .size = 0, |
| 2031 | }; |
| 2032 | |
| 2033 | ret = lttng_dynamic_buffer_append( |
| 2034 | &client->communication.outbound.buffer, &msg, |
| 2035 | sizeof(msg)); |
| 2036 | return ret; |
| 2037 | } |
| 2038 | |
| 2039 | static |
| 2040 | int send_evaluation_to_clients(struct lttng_trigger *trigger, |
| 2041 | struct lttng_evaluation *evaluation, |
| 2042 | struct notification_client_list* client_list, |
| 2043 | struct notification_thread_state *state, |
| 2044 | uid_t channel_uid, gid_t channel_gid) |
| 2045 | { |
| 2046 | int ret = 0; |
| 2047 | struct lttng_dynamic_buffer msg_buffer; |
| 2048 | struct notification_client_list_element *client_list_element, *tmp; |
| 2049 | struct lttng_notification *notification; |
| 2050 | struct lttng_condition *condition; |
| 2051 | ssize_t expected_notification_size, notification_size; |
| 2052 | struct lttng_notification_channel_message msg; |
| 2053 | |
| 2054 | lttng_dynamic_buffer_init(&msg_buffer); |
| 2055 | |
| 2056 | condition = lttng_trigger_get_condition(trigger); |
| 2057 | assert(condition); |
| 2058 | |
| 2059 | notification = lttng_notification_create(condition, evaluation); |
| 2060 | if (!notification) { |
| 2061 | ret = -1; |
| 2062 | goto end; |
| 2063 | } |
| 2064 | |
| 2065 | expected_notification_size = lttng_notification_serialize(notification, |
| 2066 | NULL); |
| 2067 | if (expected_notification_size < 0) { |
| 2068 | ERR("[notification-thread] Failed to get size of serialized notification"); |
| 2069 | ret = -1; |
| 2070 | goto end; |
| 2071 | } |
| 2072 | |
| 2073 | msg.type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION; |
| 2074 | msg.size = (uint32_t) expected_notification_size; |
| 2075 | ret = lttng_dynamic_buffer_append(&msg_buffer, &msg, sizeof(msg)); |
| 2076 | if (ret) { |
| 2077 | goto end; |
| 2078 | } |
| 2079 | |
| 2080 | ret = lttng_dynamic_buffer_set_size(&msg_buffer, |
| 2081 | msg_buffer.size + expected_notification_size); |
| 2082 | if (ret) { |
| 2083 | goto end; |
| 2084 | } |
| 2085 | |
| 2086 | notification_size = lttng_notification_serialize(notification, |
| 2087 | msg_buffer.data + sizeof(msg)); |
| 2088 | if (notification_size != expected_notification_size) { |
| 2089 | ERR("[notification-thread] Failed to serialize notification"); |
| 2090 | ret = -1; |
| 2091 | goto end; |
| 2092 | } |
| 2093 | |
| 2094 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 2095 | &client_list->list, node) { |
| 2096 | struct notification_client *client = |
| 2097 | client_list_element->client; |
| 2098 | |
| 2099 | if (client->uid != channel_uid && client->gid != channel_gid && |
| 2100 | client->uid != 0) { |
| 2101 | /* Client is not allowed to monitor this channel. */ |
| 2102 | DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this channel"); |
| 2103 | continue; |
| 2104 | } |
| 2105 | |
| 2106 | DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", |
| 2107 | client->socket, msg_buffer.size); |
| 2108 | if (client->communication.outbound.buffer.size) { |
| 2109 | /* |
| 2110 | * Outgoing data is already buffered for this client; |
| 2111 | * drop the notification and enqueue a "dropped |
| 2112 | * notification" message if this is the first dropped |
| 2113 | * notification since the socket spilled-over to the |
| 2114 | * queue. |
| 2115 | */ |
| 2116 | DBG("[notification-thread] Dropping notification addressed to client (socket fd = %i)", |
| 2117 | client->socket); |
| 2118 | if (!client->communication.outbound.dropped_notification) { |
| 2119 | client->communication.outbound.dropped_notification = true; |
| 2120 | ret = client_enqueue_dropped_notification( |
| 2121 | client, state); |
| 2122 | if (ret) { |
| 2123 | goto end; |
| 2124 | } |
| 2125 | } |
| 2126 | continue; |
| 2127 | } |
| 2128 | |
| 2129 | ret = lttng_dynamic_buffer_append_buffer( |
| 2130 | &client->communication.outbound.buffer, |
| 2131 | &msg_buffer); |
| 2132 | if (ret) { |
| 2133 | goto end; |
| 2134 | } |
| 2135 | |
| 2136 | ret = client_flush_outgoing_queue(client, state); |
| 2137 | if (ret) { |
| 2138 | goto end; |
| 2139 | } |
| 2140 | } |
| 2141 | ret = 0; |
| 2142 | end: |
| 2143 | lttng_notification_destroy(notification); |
| 2144 | lttng_dynamic_buffer_reset(&msg_buffer); |
| 2145 | return ret; |
| 2146 | } |
| 2147 | |
| 2148 | int handle_notification_thread_channel_sample( |
| 2149 | struct notification_thread_state *state, int pipe, |
| 2150 | enum lttng_domain_type domain) |
| 2151 | { |
| 2152 | int ret = 0; |
| 2153 | struct lttcomm_consumer_channel_monitor_msg sample_msg; |
| 2154 | struct channel_state_sample previous_sample, latest_sample; |
| 2155 | struct channel_info *channel_info; |
| 2156 | struct cds_lfht_node *node; |
| 2157 | struct cds_lfht_iter iter; |
| 2158 | struct lttng_channel_trigger_list *trigger_list; |
| 2159 | struct lttng_trigger_list_element *trigger_list_element; |
| 2160 | bool previous_sample_available = false; |
| 2161 | |
| 2162 | /* |
| 2163 | * The monitoring pipe only holds messages smaller than PIPE_BUF, |
| 2164 | * ensuring that read/write of sampling messages are atomic. |
| 2165 | */ |
| 2166 | ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg)); |
| 2167 | if (ret != sizeof(sample_msg)) { |
| 2168 | ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)", |
| 2169 | pipe); |
| 2170 | ret = -1; |
| 2171 | goto end; |
| 2172 | } |
| 2173 | |
| 2174 | ret = 0; |
| 2175 | latest_sample.key.key = sample_msg.key; |
| 2176 | latest_sample.key.domain = domain; |
| 2177 | latest_sample.highest_usage = sample_msg.highest; |
| 2178 | latest_sample.lowest_usage = sample_msg.lowest; |
| 2179 | |
| 2180 | rcu_read_lock(); |
| 2181 | |
| 2182 | /* Retrieve the channel's informations */ |
| 2183 | cds_lfht_lookup(state->channels_ht, |
| 2184 | hash_channel_key(&latest_sample.key), |
| 2185 | match_channel_info, |
| 2186 | &latest_sample.key, |
| 2187 | &iter); |
| 2188 | node = cds_lfht_iter_get_node(&iter); |
| 2189 | if (!node) { |
| 2190 | /* |
| 2191 | * Not an error since the consumer can push a sample to the pipe |
| 2192 | * and the rest of the session daemon could notify us of the |
| 2193 | * channel's destruction before we get a chance to process that |
| 2194 | * sample. |
| 2195 | */ |
| 2196 | DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", |
| 2197 | latest_sample.key.key, |
| 2198 | domain == LTTNG_DOMAIN_KERNEL ? "kernel" : |
| 2199 | "user space"); |
| 2200 | goto end_unlock; |
| 2201 | } |
| 2202 | channel_info = caa_container_of(node, struct channel_info, |
| 2203 | channels_ht_node); |
| 2204 | DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64")", |
| 2205 | channel_info->channel_name, |
| 2206 | latest_sample.key.key, |
| 2207 | channel_info->session_name, |
| 2208 | latest_sample.highest_usage, |
| 2209 | latest_sample.lowest_usage); |
| 2210 | |
| 2211 | /* Retrieve the channel's last sample, if it exists, and update it. */ |
| 2212 | cds_lfht_lookup(state->channel_state_ht, |
| 2213 | hash_channel_key(&latest_sample.key), |
| 2214 | match_channel_state_sample, |
| 2215 | &latest_sample.key, |
| 2216 | &iter); |
| 2217 | node = cds_lfht_iter_get_node(&iter); |
| 2218 | if (node) { |
| 2219 | struct channel_state_sample *stored_sample; |
| 2220 | |
| 2221 | /* Update the sample stored. */ |
| 2222 | stored_sample = caa_container_of(node, |
| 2223 | struct channel_state_sample, |
| 2224 | channel_state_ht_node); |
| 2225 | memcpy(&previous_sample, stored_sample, |
| 2226 | sizeof(previous_sample)); |
| 2227 | stored_sample->highest_usage = latest_sample.highest_usage; |
| 2228 | stored_sample->lowest_usage = latest_sample.lowest_usage; |
| 2229 | previous_sample_available = true; |
| 2230 | } else { |
| 2231 | /* |
| 2232 | * This is the channel's first sample, allocate space for and |
| 2233 | * store the new sample. |
| 2234 | */ |
| 2235 | struct channel_state_sample *stored_sample; |
| 2236 | |
| 2237 | stored_sample = zmalloc(sizeof(*stored_sample)); |
| 2238 | if (!stored_sample) { |
| 2239 | ret = -1; |
| 2240 | goto end_unlock; |
| 2241 | } |
| 2242 | |
| 2243 | memcpy(stored_sample, &latest_sample, sizeof(*stored_sample)); |
| 2244 | cds_lfht_node_init(&stored_sample->channel_state_ht_node); |
| 2245 | cds_lfht_add(state->channel_state_ht, |
| 2246 | hash_channel_key(&stored_sample->key), |
| 2247 | &stored_sample->channel_state_ht_node); |
| 2248 | } |
| 2249 | |
| 2250 | /* Find triggers associated with this channel. */ |
| 2251 | cds_lfht_lookup(state->channel_triggers_ht, |
| 2252 | hash_channel_key(&latest_sample.key), |
| 2253 | match_channel_trigger_list, |
| 2254 | &latest_sample.key, |
| 2255 | &iter); |
| 2256 | node = cds_lfht_iter_get_node(&iter); |
| 2257 | if (!node) { |
| 2258 | goto end_unlock; |
| 2259 | } |
| 2260 | |
| 2261 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 2262 | channel_triggers_ht_node); |
| 2263 | cds_list_for_each_entry(trigger_list_element, &trigger_list->list, |
| 2264 | node) { |
| 2265 | struct lttng_condition *condition; |
| 2266 | struct lttng_action *action; |
| 2267 | struct lttng_trigger *trigger; |
| 2268 | struct notification_client_list *client_list; |
| 2269 | struct lttng_evaluation *evaluation = NULL; |
| 2270 | |
| 2271 | trigger = trigger_list_element->trigger; |
| 2272 | condition = lttng_trigger_get_condition(trigger); |
| 2273 | assert(condition); |
| 2274 | action = lttng_trigger_get_action(trigger); |
| 2275 | |
| 2276 | /* Notify actions are the only type currently supported. */ |
| 2277 | assert(lttng_action_get_type(action) == |
| 2278 | LTTNG_ACTION_TYPE_NOTIFY); |
| 2279 | |
| 2280 | /* |
| 2281 | * Check if any client is subscribed to the result of this |
| 2282 | * evaluation. |
| 2283 | */ |
| 2284 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 2285 | lttng_condition_hash(condition), |
| 2286 | match_client_list, |
| 2287 | trigger, |
| 2288 | &iter); |
| 2289 | node = cds_lfht_iter_get_node(&iter); |
| 2290 | assert(node); |
| 2291 | |
| 2292 | client_list = caa_container_of(node, |
| 2293 | struct notification_client_list, |
| 2294 | notification_trigger_ht_node); |
| 2295 | if (cds_list_empty(&client_list->list)) { |
| 2296 | /* |
| 2297 | * No clients interested in the evaluation's result, |
| 2298 | * skip it. |
| 2299 | */ |
| 2300 | continue; |
| 2301 | } |
| 2302 | |
| 2303 | ret = evaluate_condition(condition, &evaluation, state, |
| 2304 | previous_sample_available ? &previous_sample : NULL, |
| 2305 | &latest_sample, channel_info->capacity); |
| 2306 | if (ret) { |
| 2307 | goto end_unlock; |
| 2308 | } |
| 2309 | |
| 2310 | if (!evaluation) { |
| 2311 | continue; |
| 2312 | } |
| 2313 | |
| 2314 | /* Dispatch evaluation result to all clients. */ |
| 2315 | ret = send_evaluation_to_clients(trigger_list_element->trigger, |
| 2316 | evaluation, client_list, state, |
| 2317 | channel_info->uid, channel_info->gid); |
| 2318 | if (ret) { |
| 2319 | goto end_unlock; |
| 2320 | } |
| 2321 | } |
| 2322 | end_unlock: |
| 2323 | rcu_read_unlock(); |
| 2324 | end: |
| 2325 | return ret; |
| 2326 | } |