| 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 | |
| 172 | static |
| 173 | void session_info_destroy(void *_data); |
| 174 | static |
| 175 | void session_info_get(struct session_info *session_info); |
| 176 | static |
| 177 | void session_info_put(struct session_info *session_info); |
| 178 | static |
| 179 | struct session_info *session_info_create(const char *name, |
| 180 | uid_t uid, gid_t gid); |
| 181 | static |
| 182 | void session_info_add_channel(struct session_info *session_info, |
| 183 | struct channel_info *channel_info); |
| 184 | static |
| 185 | void session_info_remove_channel(struct session_info *session_info, |
| 186 | struct channel_info *channel_info); |
| 187 | |
| 188 | static |
| 189 | int match_client(struct cds_lfht_node *node, const void *key) |
| 190 | { |
| 191 | /* This double-cast is intended to supress pointer-to-cast warning. */ |
| 192 | int socket = (int) (intptr_t) key; |
| 193 | struct notification_client *client; |
| 194 | |
| 195 | client = caa_container_of(node, struct notification_client, |
| 196 | client_socket_ht_node); |
| 197 | |
| 198 | return !!(client->socket == socket); |
| 199 | } |
| 200 | |
| 201 | static |
| 202 | int match_channel_trigger_list(struct cds_lfht_node *node, const void *key) |
| 203 | { |
| 204 | struct channel_key *channel_key = (struct channel_key *) key; |
| 205 | struct lttng_channel_trigger_list *trigger_list; |
| 206 | |
| 207 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 208 | channel_triggers_ht_node); |
| 209 | |
| 210 | return !!((channel_key->key == trigger_list->channel_key.key) && |
| 211 | (channel_key->domain == trigger_list->channel_key.domain)); |
| 212 | } |
| 213 | |
| 214 | static |
| 215 | int match_channel_state_sample(struct cds_lfht_node *node, const void *key) |
| 216 | { |
| 217 | struct channel_key *channel_key = (struct channel_key *) key; |
| 218 | struct channel_state_sample *sample; |
| 219 | |
| 220 | sample = caa_container_of(node, struct channel_state_sample, |
| 221 | channel_state_ht_node); |
| 222 | |
| 223 | return !!((channel_key->key == sample->key.key) && |
| 224 | (channel_key->domain == sample->key.domain)); |
| 225 | } |
| 226 | |
| 227 | static |
| 228 | int match_channel_info(struct cds_lfht_node *node, const void *key) |
| 229 | { |
| 230 | struct channel_key *channel_key = (struct channel_key *) key; |
| 231 | struct channel_info *channel_info; |
| 232 | |
| 233 | channel_info = caa_container_of(node, struct channel_info, |
| 234 | channels_ht_node); |
| 235 | |
| 236 | return !!((channel_key->key == channel_info->key.key) && |
| 237 | (channel_key->domain == channel_info->key.domain)); |
| 238 | } |
| 239 | |
| 240 | static |
| 241 | int match_condition(struct cds_lfht_node *node, const void *key) |
| 242 | { |
| 243 | struct lttng_condition *condition_key = (struct lttng_condition *) key; |
| 244 | struct lttng_trigger_ht_element *trigger; |
| 245 | struct lttng_condition *condition; |
| 246 | |
| 247 | trigger = caa_container_of(node, struct lttng_trigger_ht_element, |
| 248 | node); |
| 249 | condition = lttng_trigger_get_condition(trigger->trigger); |
| 250 | assert(condition); |
| 251 | |
| 252 | return !!lttng_condition_is_equal(condition_key, condition); |
| 253 | } |
| 254 | |
| 255 | static |
| 256 | int match_client_list(struct cds_lfht_node *node, const void *key) |
| 257 | { |
| 258 | struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; |
| 259 | struct notification_client_list *client_list; |
| 260 | struct lttng_condition *condition; |
| 261 | struct lttng_condition *condition_key = lttng_trigger_get_condition( |
| 262 | trigger_key); |
| 263 | |
| 264 | assert(condition_key); |
| 265 | |
| 266 | client_list = caa_container_of(node, struct notification_client_list, |
| 267 | notification_trigger_ht_node); |
| 268 | condition = lttng_trigger_get_condition(client_list->trigger); |
| 269 | |
| 270 | return !!lttng_condition_is_equal(condition_key, condition); |
| 271 | } |
| 272 | |
| 273 | static |
| 274 | int match_client_list_condition(struct cds_lfht_node *node, const void *key) |
| 275 | { |
| 276 | struct lttng_condition *condition_key = (struct lttng_condition *) key; |
| 277 | struct notification_client_list *client_list; |
| 278 | struct lttng_condition *condition; |
| 279 | |
| 280 | assert(condition_key); |
| 281 | |
| 282 | client_list = caa_container_of(node, struct notification_client_list, |
| 283 | notification_trigger_ht_node); |
| 284 | condition = lttng_trigger_get_condition(client_list->trigger); |
| 285 | |
| 286 | return !!lttng_condition_is_equal(condition_key, condition); |
| 287 | } |
| 288 | |
| 289 | static |
| 290 | unsigned long lttng_condition_buffer_usage_hash( |
| 291 | struct lttng_condition *_condition) |
| 292 | { |
| 293 | unsigned long hash = 0; |
| 294 | struct lttng_condition_buffer_usage *condition; |
| 295 | |
| 296 | condition = container_of(_condition, |
| 297 | struct lttng_condition_buffer_usage, parent); |
| 298 | |
| 299 | if (condition->session_name) { |
| 300 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); |
| 301 | } |
| 302 | if (condition->channel_name) { |
| 303 | hash ^= hash_key_str(condition->channel_name, lttng_ht_seed); |
| 304 | } |
| 305 | if (condition->domain.set) { |
| 306 | hash ^= hash_key_ulong( |
| 307 | (void *) condition->domain.type, |
| 308 | lttng_ht_seed); |
| 309 | } |
| 310 | if (condition->threshold_ratio.set) { |
| 311 | uint64_t val; |
| 312 | |
| 313 | val = condition->threshold_ratio.value * (double) UINT32_MAX; |
| 314 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 315 | } else if (condition->threshold_bytes.set) { |
| 316 | uint64_t val; |
| 317 | |
| 318 | val = condition->threshold_bytes.value; |
| 319 | hash ^= hash_key_u64(&val, lttng_ht_seed); |
| 320 | } |
| 321 | return hash; |
| 322 | } |
| 323 | |
| 324 | /* |
| 325 | * The lttng_condition hashing code is kept in this file (rather than |
| 326 | * condition.c) since it makes use of GPLv2 code (hashtable utils), which we |
| 327 | * don't want to link in liblttng-ctl. |
| 328 | */ |
| 329 | static |
| 330 | unsigned long lttng_condition_hash(struct lttng_condition *condition) |
| 331 | { |
| 332 | switch (condition->type) { |
| 333 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 334 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 335 | return lttng_condition_buffer_usage_hash(condition); |
| 336 | default: |
| 337 | ERR("[notification-thread] Unexpected condition type caught"); |
| 338 | abort(); |
| 339 | } |
| 340 | } |
| 341 | |
| 342 | static |
| 343 | unsigned long hash_channel_key(struct channel_key *key) |
| 344 | { |
| 345 | unsigned long key_hash = hash_key_u64(&key->key, lttng_ht_seed); |
| 346 | unsigned long domain_hash = hash_key_ulong( |
| 347 | (void *) (unsigned long) key->domain, lttng_ht_seed); |
| 348 | |
| 349 | return key_hash ^ domain_hash; |
| 350 | } |
| 351 | |
| 352 | static |
| 353 | void channel_info_destroy(struct channel_info *channel_info) |
| 354 | { |
| 355 | if (!channel_info) { |
| 356 | return; |
| 357 | } |
| 358 | |
| 359 | if (channel_info->session_info) { |
| 360 | session_info_remove_channel(channel_info->session_info, |
| 361 | channel_info); |
| 362 | session_info_put(channel_info->session_info); |
| 363 | } |
| 364 | if (channel_info->name) { |
| 365 | free(channel_info->name); |
| 366 | } |
| 367 | free(channel_info); |
| 368 | } |
| 369 | |
| 370 | /* Don't call directly, use the ref-counting mechanism. */ |
| 371 | static |
| 372 | void session_info_destroy(void *_data) |
| 373 | { |
| 374 | struct session_info *session_info = _data; |
| 375 | |
| 376 | assert(session_info); |
| 377 | if (session_info->channel_infos_ht) { |
| 378 | cds_lfht_destroy(session_info->channel_infos_ht, NULL); |
| 379 | } |
| 380 | free(session_info->name); |
| 381 | free(session_info); |
| 382 | } |
| 383 | |
| 384 | static |
| 385 | void session_info_get(struct session_info *session_info) |
| 386 | { |
| 387 | if (!session_info) { |
| 388 | return; |
| 389 | } |
| 390 | lttng_ref_get(&session_info->ref); |
| 391 | } |
| 392 | |
| 393 | static |
| 394 | void session_info_put(struct session_info *session_info) |
| 395 | { |
| 396 | if (!session_info) { |
| 397 | return; |
| 398 | } |
| 399 | lttng_ref_put(&session_info->ref); |
| 400 | } |
| 401 | |
| 402 | static |
| 403 | struct session_info *session_info_create(const char *name, uid_t uid, gid_t gid) |
| 404 | { |
| 405 | struct session_info *session_info; |
| 406 | |
| 407 | assert(name); |
| 408 | |
| 409 | session_info = zmalloc(sizeof(*session_info)); |
| 410 | if (!session_info) { |
| 411 | goto end; |
| 412 | } |
| 413 | lttng_ref_init(&session_info->ref, session_info_destroy); |
| 414 | |
| 415 | session_info->channel_infos_ht = cds_lfht_new(DEFAULT_HT_SIZE, |
| 416 | 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 417 | if (!session_info->channel_infos_ht) { |
| 418 | goto error; |
| 419 | } |
| 420 | |
| 421 | cds_lfht_node_init(&session_info->sessions_ht_node); |
| 422 | session_info->name = strdup(name); |
| 423 | if (!session_info->name) { |
| 424 | goto error; |
| 425 | } |
| 426 | session_info->uid = uid; |
| 427 | session_info->gid = gid; |
| 428 | end: |
| 429 | return session_info; |
| 430 | error: |
| 431 | session_info_put(session_info); |
| 432 | return NULL; |
| 433 | } |
| 434 | |
| 435 | static |
| 436 | void session_info_add_channel(struct session_info *session_info, |
| 437 | struct channel_info *channel_info) |
| 438 | { |
| 439 | rcu_read_lock(); |
| 440 | cds_lfht_add(session_info->channel_infos_ht, |
| 441 | hash_channel_key(&channel_info->key), |
| 442 | &channel_info->session_info_channels_ht_node); |
| 443 | rcu_read_unlock(); |
| 444 | } |
| 445 | |
| 446 | static |
| 447 | void session_info_remove_channel(struct session_info *session_info, |
| 448 | struct channel_info *channel_info) |
| 449 | { |
| 450 | rcu_read_lock(); |
| 451 | cds_lfht_del(session_info->channel_infos_ht, |
| 452 | &channel_info->session_info_channels_ht_node); |
| 453 | rcu_read_unlock(); |
| 454 | } |
| 455 | |
| 456 | static |
| 457 | struct channel_info *channel_info_create(const char *channel_name, |
| 458 | struct channel_key *channel_key, uint64_t channel_capacity, |
| 459 | struct session_info *session_info) |
| 460 | { |
| 461 | struct channel_info *channel_info = zmalloc(sizeof(*channel_info)); |
| 462 | |
| 463 | if (!channel_info) { |
| 464 | goto end; |
| 465 | } |
| 466 | |
| 467 | cds_lfht_node_init(&channel_info->channels_ht_node); |
| 468 | cds_lfht_node_init(&channel_info->session_info_channels_ht_node); |
| 469 | memcpy(&channel_info->key, channel_key, sizeof(*channel_key)); |
| 470 | channel_info->capacity = channel_capacity; |
| 471 | |
| 472 | channel_info->name = strdup(channel_name); |
| 473 | if (!channel_info->name) { |
| 474 | goto error; |
| 475 | } |
| 476 | |
| 477 | /* |
| 478 | * Set the references between session and channel infos: |
| 479 | * - channel_info holds a strong reference to session_info |
| 480 | * - session_info holds a weak reference to channel_info |
| 481 | */ |
| 482 | session_info_get(session_info); |
| 483 | session_info_add_channel(session_info, channel_info); |
| 484 | channel_info->session_info = session_info; |
| 485 | end: |
| 486 | return channel_info; |
| 487 | error: |
| 488 | channel_info_destroy(channel_info); |
| 489 | return NULL; |
| 490 | } |
| 491 | |
| 492 | /* This function must be called with the RCU read lock held. */ |
| 493 | static |
| 494 | int evaluate_condition_for_client(struct lttng_trigger *trigger, |
| 495 | struct lttng_condition *condition, |
| 496 | struct notification_client *client, |
| 497 | struct notification_thread_state *state) |
| 498 | { |
| 499 | int ret; |
| 500 | struct cds_lfht_iter iter; |
| 501 | struct cds_lfht_node *node; |
| 502 | struct channel_info *channel_info = NULL; |
| 503 | struct channel_key *channel_key = NULL; |
| 504 | struct channel_state_sample *last_sample = NULL; |
| 505 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
| 506 | struct lttng_evaluation *evaluation = NULL; |
| 507 | struct notification_client_list client_list = { 0 }; |
| 508 | struct notification_client_list_element client_list_element = { 0 }; |
| 509 | |
| 510 | assert(trigger); |
| 511 | assert(condition); |
| 512 | assert(client); |
| 513 | assert(state); |
| 514 | |
| 515 | /* Find the channel associated with the trigger. */ |
| 516 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, |
| 517 | channel_trigger_list , channel_triggers_ht_node) { |
| 518 | struct lttng_trigger_list_element *element; |
| 519 | |
| 520 | cds_list_for_each_entry(element, &channel_trigger_list->list, node) { |
| 521 | struct lttng_condition *current_condition = |
| 522 | lttng_trigger_get_condition( |
| 523 | element->trigger); |
| 524 | |
| 525 | assert(current_condition); |
| 526 | if (!lttng_condition_is_equal(condition, |
| 527 | current_condition)) { |
| 528 | continue; |
| 529 | } |
| 530 | |
| 531 | /* Found the trigger, save the channel key. */ |
| 532 | channel_key = &channel_trigger_list->channel_key; |
| 533 | break; |
| 534 | } |
| 535 | if (channel_key) { |
| 536 | /* The channel key was found stop iteration. */ |
| 537 | break; |
| 538 | } |
| 539 | } |
| 540 | |
| 541 | if (!channel_key){ |
| 542 | /* No channel found; normal exit. */ |
| 543 | DBG("[notification-thread] No channel associated with newly subscribed-to condition"); |
| 544 | ret = 0; |
| 545 | goto end; |
| 546 | } |
| 547 | |
| 548 | /* Fetch channel info for the matching channel. */ |
| 549 | cds_lfht_lookup(state->channels_ht, |
| 550 | hash_channel_key(channel_key), |
| 551 | match_channel_info, |
| 552 | channel_key, |
| 553 | &iter); |
| 554 | node = cds_lfht_iter_get_node(&iter); |
| 555 | assert(node); |
| 556 | channel_info = caa_container_of(node, struct channel_info, |
| 557 | channels_ht_node); |
| 558 | |
| 559 | /* Retrieve the channel's last sample, if it exists. */ |
| 560 | cds_lfht_lookup(state->channel_state_ht, |
| 561 | hash_channel_key(channel_key), |
| 562 | match_channel_state_sample, |
| 563 | channel_key, |
| 564 | &iter); |
| 565 | node = cds_lfht_iter_get_node(&iter); |
| 566 | if (node) { |
| 567 | last_sample = caa_container_of(node, |
| 568 | struct channel_state_sample, |
| 569 | channel_state_ht_node); |
| 570 | } else { |
| 571 | /* Nothing to evaluate, no sample was ever taken. Normal exit */ |
| 572 | DBG("[notification-thread] No channel sample associated with newly subscribed-to condition"); |
| 573 | ret = 0; |
| 574 | goto end; |
| 575 | } |
| 576 | |
| 577 | ret = evaluate_condition(condition, &evaluation, state, NULL, |
| 578 | last_sample, channel_info->capacity); |
| 579 | if (ret) { |
| 580 | WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition"); |
| 581 | goto end; |
| 582 | } |
| 583 | |
| 584 | if (!evaluation) { |
| 585 | /* Evaluation yielded nothing. Normal exit. */ |
| 586 | DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client"); |
| 587 | ret = 0; |
| 588 | goto end; |
| 589 | } |
| 590 | |
| 591 | /* |
| 592 | * Create a temporary client list with the client currently |
| 593 | * subscribing. |
| 594 | */ |
| 595 | cds_lfht_node_init(&client_list.notification_trigger_ht_node); |
| 596 | CDS_INIT_LIST_HEAD(&client_list.list); |
| 597 | client_list.trigger = trigger; |
| 598 | |
| 599 | CDS_INIT_LIST_HEAD(&client_list_element.node); |
| 600 | client_list_element.client = client; |
| 601 | cds_list_add(&client_list_element.node, &client_list.list); |
| 602 | |
| 603 | /* Send evaluation result to the newly-subscribed client. */ |
| 604 | DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client"); |
| 605 | ret = send_evaluation_to_clients(trigger, evaluation, &client_list, |
| 606 | state, channel_info->session_info->uid, |
| 607 | channel_info->session_info->gid); |
| 608 | |
| 609 | end: |
| 610 | return ret; |
| 611 | } |
| 612 | |
| 613 | static |
| 614 | int notification_thread_client_subscribe(struct notification_client *client, |
| 615 | struct lttng_condition *condition, |
| 616 | struct notification_thread_state *state, |
| 617 | enum lttng_notification_channel_status *_status) |
| 618 | { |
| 619 | int ret = 0; |
| 620 | struct cds_lfht_iter iter; |
| 621 | struct cds_lfht_node *node; |
| 622 | struct notification_client_list *client_list; |
| 623 | struct lttng_condition_list_element *condition_list_element = NULL; |
| 624 | struct notification_client_list_element *client_list_element = NULL; |
| 625 | enum lttng_notification_channel_status status = |
| 626 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 627 | |
| 628 | /* |
| 629 | * Ensure that the client has not already subscribed to this condition |
| 630 | * before. |
| 631 | */ |
| 632 | cds_list_for_each_entry(condition_list_element, &client->condition_list, node) { |
| 633 | if (lttng_condition_is_equal(condition_list_element->condition, |
| 634 | condition)) { |
| 635 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED; |
| 636 | goto end; |
| 637 | } |
| 638 | } |
| 639 | |
| 640 | condition_list_element = zmalloc(sizeof(*condition_list_element)); |
| 641 | if (!condition_list_element) { |
| 642 | ret = -1; |
| 643 | goto error; |
| 644 | } |
| 645 | client_list_element = zmalloc(sizeof(*client_list_element)); |
| 646 | if (!client_list_element) { |
| 647 | ret = -1; |
| 648 | goto error; |
| 649 | } |
| 650 | |
| 651 | rcu_read_lock(); |
| 652 | |
| 653 | /* |
| 654 | * Add the newly-subscribed condition to the client's subscription list. |
| 655 | */ |
| 656 | CDS_INIT_LIST_HEAD(&condition_list_element->node); |
| 657 | condition_list_element->condition = condition; |
| 658 | cds_list_add(&condition_list_element->node, &client->condition_list); |
| 659 | |
| 660 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 661 | lttng_condition_hash(condition), |
| 662 | match_client_list_condition, |
| 663 | condition, |
| 664 | &iter); |
| 665 | node = cds_lfht_iter_get_node(&iter); |
| 666 | if (!node) { |
| 667 | /* |
| 668 | * No notification-emiting trigger registered with this |
| 669 | * condition. We don't evaluate the condition right away |
| 670 | * since this trigger is not registered yet. |
| 671 | */ |
| 672 | free(client_list_element); |
| 673 | goto end_unlock; |
| 674 | } |
| 675 | |
| 676 | client_list = caa_container_of(node, struct notification_client_list, |
| 677 | notification_trigger_ht_node); |
| 678 | /* |
| 679 | * The condition to which the client just subscribed is evaluated |
| 680 | * at this point so that conditions that are already TRUE result |
| 681 | * in a notification being sent out. |
| 682 | */ |
| 683 | if (evaluate_condition_for_client(client_list->trigger, condition, |
| 684 | client, state)) { |
| 685 | WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); |
| 686 | ret = -1; |
| 687 | goto end_unlock; |
| 688 | } |
| 689 | |
| 690 | /* |
| 691 | * Add the client to the list of clients interested in a given trigger |
| 692 | * if a "notification" trigger with a corresponding condition was |
| 693 | * added prior. |
| 694 | */ |
| 695 | client_list_element->client = client; |
| 696 | CDS_INIT_LIST_HEAD(&client_list_element->node); |
| 697 | cds_list_add(&client_list_element->node, &client_list->list); |
| 698 | end_unlock: |
| 699 | rcu_read_unlock(); |
| 700 | end: |
| 701 | if (_status) { |
| 702 | *_status = status; |
| 703 | } |
| 704 | return ret; |
| 705 | error: |
| 706 | free(condition_list_element); |
| 707 | free(client_list_element); |
| 708 | return ret; |
| 709 | } |
| 710 | |
| 711 | static |
| 712 | int notification_thread_client_unsubscribe( |
| 713 | struct notification_client *client, |
| 714 | struct lttng_condition *condition, |
| 715 | struct notification_thread_state *state, |
| 716 | enum lttng_notification_channel_status *_status) |
| 717 | { |
| 718 | struct cds_lfht_iter iter; |
| 719 | struct cds_lfht_node *node; |
| 720 | struct notification_client_list *client_list; |
| 721 | struct lttng_condition_list_element *condition_list_element, |
| 722 | *condition_tmp; |
| 723 | struct notification_client_list_element *client_list_element, |
| 724 | *client_tmp; |
| 725 | bool condition_found = false; |
| 726 | enum lttng_notification_channel_status status = |
| 727 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 728 | |
| 729 | /* Remove the condition from the client's condition list. */ |
| 730 | cds_list_for_each_entry_safe(condition_list_element, condition_tmp, |
| 731 | &client->condition_list, node) { |
| 732 | if (!lttng_condition_is_equal(condition_list_element->condition, |
| 733 | condition)) { |
| 734 | continue; |
| 735 | } |
| 736 | |
| 737 | cds_list_del(&condition_list_element->node); |
| 738 | /* |
| 739 | * The caller may be iterating on the client's conditions to |
| 740 | * tear down a client's connection. In this case, the condition |
| 741 | * will be destroyed at the end. |
| 742 | */ |
| 743 | if (condition != condition_list_element->condition) { |
| 744 | lttng_condition_destroy( |
| 745 | condition_list_element->condition); |
| 746 | } |
| 747 | free(condition_list_element); |
| 748 | condition_found = true; |
| 749 | break; |
| 750 | } |
| 751 | |
| 752 | if (!condition_found) { |
| 753 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION; |
| 754 | goto end; |
| 755 | } |
| 756 | |
| 757 | /* |
| 758 | * Remove the client from the list of clients interested the trigger |
| 759 | * matching the condition. |
| 760 | */ |
| 761 | rcu_read_lock(); |
| 762 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 763 | lttng_condition_hash(condition), |
| 764 | match_client_list_condition, |
| 765 | condition, |
| 766 | &iter); |
| 767 | node = cds_lfht_iter_get_node(&iter); |
| 768 | if (!node) { |
| 769 | goto end_unlock; |
| 770 | } |
| 771 | |
| 772 | client_list = caa_container_of(node, struct notification_client_list, |
| 773 | notification_trigger_ht_node); |
| 774 | cds_list_for_each_entry_safe(client_list_element, client_tmp, |
| 775 | &client_list->list, node) { |
| 776 | if (client_list_element->client->socket != client->socket) { |
| 777 | continue; |
| 778 | } |
| 779 | cds_list_del(&client_list_element->node); |
| 780 | free(client_list_element); |
| 781 | break; |
| 782 | } |
| 783 | end_unlock: |
| 784 | rcu_read_unlock(); |
| 785 | end: |
| 786 | lttng_condition_destroy(condition); |
| 787 | if (_status) { |
| 788 | *_status = status; |
| 789 | } |
| 790 | return 0; |
| 791 | } |
| 792 | |
| 793 | static |
| 794 | void notification_client_destroy(struct notification_client *client, |
| 795 | struct notification_thread_state *state) |
| 796 | { |
| 797 | struct lttng_condition_list_element *condition_list_element, *tmp; |
| 798 | |
| 799 | if (!client) { |
| 800 | return; |
| 801 | } |
| 802 | |
| 803 | /* Release all conditions to which the client was subscribed. */ |
| 804 | cds_list_for_each_entry_safe(condition_list_element, tmp, |
| 805 | &client->condition_list, node) { |
| 806 | (void) notification_thread_client_unsubscribe(client, |
| 807 | condition_list_element->condition, state, NULL); |
| 808 | } |
| 809 | |
| 810 | if (client->socket >= 0) { |
| 811 | (void) lttcomm_close_unix_sock(client->socket); |
| 812 | } |
| 813 | lttng_dynamic_buffer_reset(&client->communication.inbound.buffer); |
| 814 | lttng_dynamic_buffer_reset(&client->communication.outbound.buffer); |
| 815 | free(client); |
| 816 | } |
| 817 | |
| 818 | /* |
| 819 | * Call with rcu_read_lock held (and hold for the lifetime of the returned |
| 820 | * client pointer). |
| 821 | */ |
| 822 | static |
| 823 | struct notification_client *get_client_from_socket(int socket, |
| 824 | struct notification_thread_state *state) |
| 825 | { |
| 826 | struct cds_lfht_iter iter; |
| 827 | struct cds_lfht_node *node; |
| 828 | struct notification_client *client = NULL; |
| 829 | |
| 830 | cds_lfht_lookup(state->client_socket_ht, |
| 831 | hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed), |
| 832 | match_client, |
| 833 | (void *) (unsigned long) socket, |
| 834 | &iter); |
| 835 | node = cds_lfht_iter_get_node(&iter); |
| 836 | if (!node) { |
| 837 | goto end; |
| 838 | } |
| 839 | |
| 840 | client = caa_container_of(node, struct notification_client, |
| 841 | client_socket_ht_node); |
| 842 | end: |
| 843 | return client; |
| 844 | } |
| 845 | |
| 846 | static |
| 847 | bool trigger_applies_to_channel(struct lttng_trigger *trigger, |
| 848 | struct channel_info *channel_info) |
| 849 | { |
| 850 | enum lttng_condition_status status; |
| 851 | struct lttng_condition *condition; |
| 852 | const char *trigger_session_name = NULL; |
| 853 | const char *trigger_channel_name = NULL; |
| 854 | enum lttng_domain_type trigger_domain; |
| 855 | |
| 856 | condition = lttng_trigger_get_condition(trigger); |
| 857 | if (!condition) { |
| 858 | goto fail; |
| 859 | } |
| 860 | |
| 861 | switch (lttng_condition_get_type(condition)) { |
| 862 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 863 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 864 | break; |
| 865 | default: |
| 866 | goto fail; |
| 867 | } |
| 868 | |
| 869 | status = lttng_condition_buffer_usage_get_domain_type(condition, |
| 870 | &trigger_domain); |
| 871 | assert(status == LTTNG_CONDITION_STATUS_OK); |
| 872 | if (channel_info->key.domain != trigger_domain) { |
| 873 | goto fail; |
| 874 | } |
| 875 | |
| 876 | status = lttng_condition_buffer_usage_get_session_name( |
| 877 | condition, &trigger_session_name); |
| 878 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_session_name); |
| 879 | |
| 880 | status = lttng_condition_buffer_usage_get_channel_name( |
| 881 | condition, &trigger_channel_name); |
| 882 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_channel_name); |
| 883 | |
| 884 | if (strcmp(channel_info->session_info->name, trigger_session_name)) { |
| 885 | goto fail; |
| 886 | } |
| 887 | if (strcmp(channel_info->name, trigger_channel_name)) { |
| 888 | goto fail; |
| 889 | } |
| 890 | |
| 891 | return true; |
| 892 | fail: |
| 893 | return false; |
| 894 | } |
| 895 | |
| 896 | static |
| 897 | bool trigger_applies_to_client(struct lttng_trigger *trigger, |
| 898 | struct notification_client *client) |
| 899 | { |
| 900 | bool applies = false; |
| 901 | struct lttng_condition_list_element *condition_list_element; |
| 902 | |
| 903 | cds_list_for_each_entry(condition_list_element, &client->condition_list, |
| 904 | node) { |
| 905 | applies = lttng_condition_is_equal( |
| 906 | condition_list_element->condition, |
| 907 | lttng_trigger_get_condition(trigger)); |
| 908 | if (applies) { |
| 909 | break; |
| 910 | } |
| 911 | } |
| 912 | return applies; |
| 913 | } |
| 914 | |
| 915 | static |
| 916 | int match_session(struct cds_lfht_node *node, const void *key) |
| 917 | { |
| 918 | const char *name = key; |
| 919 | struct session_info *session_info = caa_container_of( |
| 920 | node, struct session_info, sessions_ht_node); |
| 921 | |
| 922 | return !strcmp(session_info->name, name); |
| 923 | } |
| 924 | |
| 925 | static |
| 926 | struct session_info *find_or_create_session_info( |
| 927 | struct notification_thread_state *state, |
| 928 | const char *name, uid_t uid, gid_t gid) |
| 929 | { |
| 930 | struct session_info *session = NULL; |
| 931 | struct cds_lfht_node *node; |
| 932 | struct cds_lfht_iter iter; |
| 933 | |
| 934 | rcu_read_lock(); |
| 935 | cds_lfht_lookup(state->sessions_ht, |
| 936 | hash_key_str(name, lttng_ht_seed), |
| 937 | match_session, |
| 938 | name, |
| 939 | &iter); |
| 940 | node = cds_lfht_iter_get_node(&iter); |
| 941 | if (node) { |
| 942 | DBG("[notification-thread] Found session info of session \"%s\" (uid = %i, gid = %i)", |
| 943 | name, uid, gid); |
| 944 | session = caa_container_of(node, struct session_info, |
| 945 | sessions_ht_node); |
| 946 | assert(session->uid == uid); |
| 947 | assert(session->gid == gid); |
| 948 | goto end; |
| 949 | } |
| 950 | |
| 951 | session = session_info_create(name, uid, gid); |
| 952 | if (!session) { |
| 953 | ERR("[notification-thread] Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)", |
| 954 | name, uid, gid); |
| 955 | goto end; |
| 956 | } |
| 957 | end: |
| 958 | rcu_read_unlock(); |
| 959 | return session; |
| 960 | } |
| 961 | |
| 962 | static |
| 963 | int handle_notification_thread_command_add_channel( |
| 964 | struct notification_thread_state *state, |
| 965 | const char *session_name, uid_t session_uid, gid_t session_gid, |
| 966 | const char *channel_name, enum lttng_domain_type channel_domain, |
| 967 | uint64_t channel_key_int, uint64_t channel_capacity, |
| 968 | enum lttng_error_code *cmd_result) |
| 969 | { |
| 970 | struct cds_list_head trigger_list; |
| 971 | struct channel_info *new_channel_info = NULL; |
| 972 | struct channel_key channel_key = { |
| 973 | .key = channel_key_int, |
| 974 | .domain = channel_domain, |
| 975 | }; |
| 976 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
| 977 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 978 | int trigger_count = 0; |
| 979 | struct cds_lfht_iter iter; |
| 980 | struct session_info *session_info = NULL; |
| 981 | |
| 982 | DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", |
| 983 | channel_name, session_name, channel_key_int, |
| 984 | channel_domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); |
| 985 | |
| 986 | CDS_INIT_LIST_HEAD(&trigger_list); |
| 987 | |
| 988 | session_info = find_or_create_session_info(state, session_name, |
| 989 | session_uid, session_gid); |
| 990 | if (!session_info) { |
| 991 | /* Allocation error or an internal error occured. */ |
| 992 | goto error; |
| 993 | } |
| 994 | |
| 995 | new_channel_info = channel_info_create(channel_name, &channel_key, |
| 996 | channel_capacity, session_info); |
| 997 | if (!new_channel_info) { |
| 998 | goto error; |
| 999 | } |
| 1000 | |
| 1001 | /* Build a list of all triggers applying to the new channel. */ |
| 1002 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 1003 | node) { |
| 1004 | struct lttng_trigger_list_element *new_element; |
| 1005 | |
| 1006 | if (!trigger_applies_to_channel(trigger_ht_element->trigger, |
| 1007 | new_channel_info)) { |
| 1008 | continue; |
| 1009 | } |
| 1010 | |
| 1011 | new_element = zmalloc(sizeof(*new_element)); |
| 1012 | if (!new_element) { |
| 1013 | goto error; |
| 1014 | } |
| 1015 | CDS_INIT_LIST_HEAD(&new_element->node); |
| 1016 | new_element->trigger = trigger_ht_element->trigger; |
| 1017 | cds_list_add(&new_element->node, &trigger_list); |
| 1018 | trigger_count++; |
| 1019 | } |
| 1020 | |
| 1021 | DBG("[notification-thread] Found %i triggers that apply to newly added channel", |
| 1022 | trigger_count); |
| 1023 | channel_trigger_list = zmalloc(sizeof(*channel_trigger_list)); |
| 1024 | if (!channel_trigger_list) { |
| 1025 | goto error; |
| 1026 | } |
| 1027 | channel_trigger_list->channel_key = new_channel_info->key; |
| 1028 | CDS_INIT_LIST_HEAD(&channel_trigger_list->list); |
| 1029 | cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node); |
| 1030 | cds_list_splice(&trigger_list, &channel_trigger_list->list); |
| 1031 | |
| 1032 | rcu_read_lock(); |
| 1033 | /* Add channel to the channel_ht which owns the channel_infos. */ |
| 1034 | cds_lfht_add(state->channels_ht, |
| 1035 | hash_channel_key(&new_channel_info->key), |
| 1036 | &new_channel_info->channels_ht_node); |
| 1037 | /* |
| 1038 | * Add the list of triggers associated with this channel to the |
| 1039 | * channel_triggers_ht. |
| 1040 | */ |
| 1041 | cds_lfht_add(state->channel_triggers_ht, |
| 1042 | hash_channel_key(&new_channel_info->key), |
| 1043 | &channel_trigger_list->channel_triggers_ht_node); |
| 1044 | rcu_read_unlock(); |
| 1045 | *cmd_result = LTTNG_OK; |
| 1046 | return 0; |
| 1047 | error: |
| 1048 | channel_info_destroy(new_channel_info); |
| 1049 | session_info_put(session_info); |
| 1050 | return 1; |
| 1051 | } |
| 1052 | |
| 1053 | static |
| 1054 | int handle_notification_thread_command_remove_channel( |
| 1055 | struct notification_thread_state *state, |
| 1056 | uint64_t channel_key, enum lttng_domain_type domain, |
| 1057 | enum lttng_error_code *cmd_result) |
| 1058 | { |
| 1059 | struct cds_lfht_node *node; |
| 1060 | struct cds_lfht_iter iter; |
| 1061 | struct lttng_channel_trigger_list *trigger_list; |
| 1062 | struct lttng_trigger_list_element *trigger_list_element, *tmp; |
| 1063 | struct channel_key key = { .key = channel_key, .domain = domain }; |
| 1064 | struct channel_info *channel_info; |
| 1065 | |
| 1066 | DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", |
| 1067 | channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); |
| 1068 | |
| 1069 | rcu_read_lock(); |
| 1070 | |
| 1071 | cds_lfht_lookup(state->channel_triggers_ht, |
| 1072 | hash_channel_key(&key), |
| 1073 | match_channel_trigger_list, |
| 1074 | &key, |
| 1075 | &iter); |
| 1076 | node = cds_lfht_iter_get_node(&iter); |
| 1077 | /* |
| 1078 | * There is a severe internal error if we are being asked to remove a |
| 1079 | * channel that doesn't exist. |
| 1080 | */ |
| 1081 | if (!node) { |
| 1082 | ERR("[notification-thread] Channel being removed is unknown to the notification thread"); |
| 1083 | goto end; |
| 1084 | } |
| 1085 | |
| 1086 | /* Free the list of triggers associated with this channel. */ |
| 1087 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 1088 | channel_triggers_ht_node); |
| 1089 | cds_list_for_each_entry_safe(trigger_list_element, tmp, |
| 1090 | &trigger_list->list, node) { |
| 1091 | cds_list_del(&trigger_list_element->node); |
| 1092 | free(trigger_list_element); |
| 1093 | } |
| 1094 | cds_lfht_del(state->channel_triggers_ht, node); |
| 1095 | free(trigger_list); |
| 1096 | |
| 1097 | /* Free sampled channel state. */ |
| 1098 | cds_lfht_lookup(state->channel_state_ht, |
| 1099 | hash_channel_key(&key), |
| 1100 | match_channel_state_sample, |
| 1101 | &key, |
| 1102 | &iter); |
| 1103 | node = cds_lfht_iter_get_node(&iter); |
| 1104 | /* |
| 1105 | * This is expected to be NULL if the channel is destroyed before we |
| 1106 | * received a sample. |
| 1107 | */ |
| 1108 | if (node) { |
| 1109 | struct channel_state_sample *sample = caa_container_of(node, |
| 1110 | struct channel_state_sample, |
| 1111 | channel_state_ht_node); |
| 1112 | |
| 1113 | cds_lfht_del(state->channel_state_ht, node); |
| 1114 | free(sample); |
| 1115 | } |
| 1116 | |
| 1117 | /* Remove the channel from the channels_ht and free it. */ |
| 1118 | cds_lfht_lookup(state->channels_ht, |
| 1119 | hash_channel_key(&key), |
| 1120 | match_channel_info, |
| 1121 | &key, |
| 1122 | &iter); |
| 1123 | node = cds_lfht_iter_get_node(&iter); |
| 1124 | assert(node); |
| 1125 | channel_info = caa_container_of(node, struct channel_info, |
| 1126 | channels_ht_node); |
| 1127 | cds_lfht_del(state->channels_ht, node); |
| 1128 | channel_info_destroy(channel_info); |
| 1129 | end: |
| 1130 | rcu_read_unlock(); |
| 1131 | *cmd_result = LTTNG_OK; |
| 1132 | return 0; |
| 1133 | } |
| 1134 | |
| 1135 | static |
| 1136 | int condition_is_supported(struct lttng_condition *condition) |
| 1137 | { |
| 1138 | int ret; |
| 1139 | |
| 1140 | switch (lttng_condition_get_type(condition)) { |
| 1141 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: |
| 1142 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: |
| 1143 | { |
| 1144 | enum lttng_domain_type domain; |
| 1145 | |
| 1146 | ret = lttng_condition_buffer_usage_get_domain_type(condition, |
| 1147 | &domain); |
| 1148 | if (ret) { |
| 1149 | ret = -1; |
| 1150 | goto end; |
| 1151 | } |
| 1152 | |
| 1153 | if (domain != LTTNG_DOMAIN_KERNEL) { |
| 1154 | ret = 1; |
| 1155 | goto end; |
| 1156 | } |
| 1157 | |
| 1158 | /* |
| 1159 | * Older kernel tracers don't expose the API to monitor their |
| 1160 | * buffers. Therefore, we reject triggers that require that |
| 1161 | * mechanism to be available to be evaluated. |
| 1162 | */ |
| 1163 | ret = kernel_supports_ring_buffer_snapshot_sample_positions( |
| 1164 | kernel_tracer_fd); |
| 1165 | break; |
| 1166 | } |
| 1167 | default: |
| 1168 | ret = 1; |
| 1169 | } |
| 1170 | end: |
| 1171 | return ret; |
| 1172 | } |
| 1173 | |
| 1174 | /* |
| 1175 | * FIXME A client's credentials are not checked when registering a trigger, nor |
| 1176 | * are they stored alongside with the trigger. |
| 1177 | * |
| 1178 | * The effects of this are benign since: |
| 1179 | * - The client will succeed in registering the trigger, as it is valid, |
| 1180 | * - The trigger will, internally, be bound to the channel, |
| 1181 | * - The notifications will not be sent since the client's credentials |
| 1182 | * are checked against the channel at that moment. |
| 1183 | * |
| 1184 | * If this function returns a non-zero value, it means something is |
| 1185 | * fundamentally broken and the whole subsystem/thread will be torn down. |
| 1186 | * |
| 1187 | * If a non-fatal error occurs, just set the cmd_result to the appropriate |
| 1188 | * error code. |
| 1189 | */ |
| 1190 | static |
| 1191 | int handle_notification_thread_command_register_trigger( |
| 1192 | struct notification_thread_state *state, |
| 1193 | struct lttng_trigger *trigger, |
| 1194 | enum lttng_error_code *cmd_result) |
| 1195 | { |
| 1196 | int ret = 0; |
| 1197 | struct lttng_condition *condition; |
| 1198 | struct notification_client *client; |
| 1199 | struct notification_client_list *client_list = NULL; |
| 1200 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1201 | struct notification_client_list_element *client_list_element, *tmp; |
| 1202 | struct cds_lfht_node *node; |
| 1203 | struct cds_lfht_iter iter; |
| 1204 | struct channel_info *channel; |
| 1205 | bool free_trigger = true; |
| 1206 | |
| 1207 | rcu_read_lock(); |
| 1208 | |
| 1209 | condition = lttng_trigger_get_condition(trigger); |
| 1210 | assert(condition); |
| 1211 | |
| 1212 | ret = condition_is_supported(condition); |
| 1213 | if (ret < 0) { |
| 1214 | goto error; |
| 1215 | } else if (ret == 0) { |
| 1216 | *cmd_result = LTTNG_ERR_NOT_SUPPORTED; |
| 1217 | goto error; |
| 1218 | } else { |
| 1219 | /* Feature is supported, continue. */ |
| 1220 | ret = 0; |
| 1221 | } |
| 1222 | |
| 1223 | trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); |
| 1224 | if (!trigger_ht_element) { |
| 1225 | ret = -1; |
| 1226 | goto error; |
| 1227 | } |
| 1228 | |
| 1229 | /* Add trigger to the trigger_ht. */ |
| 1230 | cds_lfht_node_init(&trigger_ht_element->node); |
| 1231 | trigger_ht_element->trigger = trigger; |
| 1232 | |
| 1233 | node = cds_lfht_add_unique(state->triggers_ht, |
| 1234 | lttng_condition_hash(condition), |
| 1235 | match_condition, |
| 1236 | condition, |
| 1237 | &trigger_ht_element->node); |
| 1238 | if (node != &trigger_ht_element->node) { |
| 1239 | /* Not a fatal error, simply report it to the client. */ |
| 1240 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; |
| 1241 | goto error_free_ht_element; |
| 1242 | } |
| 1243 | |
| 1244 | /* |
| 1245 | * Ownership of the trigger and of its wrapper was transfered to |
| 1246 | * the triggers_ht. |
| 1247 | */ |
| 1248 | trigger_ht_element = NULL; |
| 1249 | free_trigger = false; |
| 1250 | |
| 1251 | /* |
| 1252 | * The rest only applies to triggers that have a "notify" action. |
| 1253 | * It is not skipped as this is the only action type currently |
| 1254 | * supported. |
| 1255 | */ |
| 1256 | client_list = zmalloc(sizeof(*client_list)); |
| 1257 | if (!client_list) { |
| 1258 | ret = -1; |
| 1259 | goto error_free_ht_element; |
| 1260 | } |
| 1261 | cds_lfht_node_init(&client_list->notification_trigger_ht_node); |
| 1262 | CDS_INIT_LIST_HEAD(&client_list->list); |
| 1263 | client_list->trigger = trigger; |
| 1264 | |
| 1265 | /* Build a list of clients to which this new trigger applies. */ |
| 1266 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, |
| 1267 | client_socket_ht_node) { |
| 1268 | if (!trigger_applies_to_client(trigger, client)) { |
| 1269 | continue; |
| 1270 | } |
| 1271 | |
| 1272 | client_list_element = zmalloc(sizeof(*client_list_element)); |
| 1273 | if (!client_list_element) { |
| 1274 | ret = -1; |
| 1275 | goto error_free_client_list; |
| 1276 | } |
| 1277 | CDS_INIT_LIST_HEAD(&client_list_element->node); |
| 1278 | client_list_element->client = client; |
| 1279 | cds_list_add(&client_list_element->node, &client_list->list); |
| 1280 | } |
| 1281 | |
| 1282 | cds_lfht_add(state->notification_trigger_clients_ht, |
| 1283 | lttng_condition_hash(condition), |
| 1284 | &client_list->notification_trigger_ht_node); |
| 1285 | |
| 1286 | /* |
| 1287 | * Add the trigger to list of triggers bound to the channels currently |
| 1288 | * known. |
| 1289 | */ |
| 1290 | cds_lfht_for_each_entry(state->channels_ht, &iter, channel, |
| 1291 | channels_ht_node) { |
| 1292 | struct lttng_trigger_list_element *trigger_list_element; |
| 1293 | struct lttng_channel_trigger_list *trigger_list; |
| 1294 | |
| 1295 | if (!trigger_applies_to_channel(trigger, channel)) { |
| 1296 | continue; |
| 1297 | } |
| 1298 | |
| 1299 | cds_lfht_lookup(state->channel_triggers_ht, |
| 1300 | hash_channel_key(&channel->key), |
| 1301 | match_channel_trigger_list, |
| 1302 | &channel->key, |
| 1303 | &iter); |
| 1304 | node = cds_lfht_iter_get_node(&iter); |
| 1305 | assert(node); |
| 1306 | trigger_list = caa_container_of(node, |
| 1307 | struct lttng_channel_trigger_list, |
| 1308 | channel_triggers_ht_node); |
| 1309 | |
| 1310 | trigger_list_element = zmalloc(sizeof(*trigger_list_element)); |
| 1311 | if (!trigger_list_element) { |
| 1312 | ret = -1; |
| 1313 | goto error_free_client_list; |
| 1314 | } |
| 1315 | CDS_INIT_LIST_HEAD(&trigger_list_element->node); |
| 1316 | trigger_list_element->trigger = trigger; |
| 1317 | cds_list_add(&trigger_list_element->node, &trigger_list->list); |
| 1318 | |
| 1319 | /* A trigger can only apply to one channel. */ |
| 1320 | break; |
| 1321 | } |
| 1322 | |
| 1323 | /* |
| 1324 | * Since there is nothing preventing clients from subscribing to a |
| 1325 | * condition before the corresponding trigger is registered, we have |
| 1326 | * to evaluate this new condition right away. |
| 1327 | * |
| 1328 | * At some point, we were waiting for the next "evaluation" (e.g. on |
| 1329 | * reception of a channel sample) to evaluate this new condition, but |
| 1330 | * that was broken. |
| 1331 | * |
| 1332 | * The reason it was broken is that waiting for the next sample |
| 1333 | * does not allow us to properly handle transitions for edge-triggered |
| 1334 | * conditions. |
| 1335 | * |
| 1336 | * Consider this example: when we handle a new channel sample, we |
| 1337 | * evaluate each conditions twice: once with the previous state, and |
| 1338 | * again with the newest state. We then use those two results to |
| 1339 | * determine whether a state change happened: a condition was false and |
| 1340 | * became true. If a state change happened, we have to notify clients. |
| 1341 | * |
| 1342 | * Now, if a client subscribes to a given notification and registers |
| 1343 | * a trigger *after* that subscription, we have to make sure the |
| 1344 | * condition is evaluated at this point while considering only the |
| 1345 | * current state. Otherwise, the next evaluation cycle may only see |
| 1346 | * that the evaluations remain the same (true for samples n-1 and n) and |
| 1347 | * the client will never know that the condition has been met. |
| 1348 | */ |
| 1349 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 1350 | &client_list->list, node) { |
| 1351 | ret = evaluate_condition_for_client(trigger, condition, |
| 1352 | client_list_element->client, state); |
| 1353 | if (ret) { |
| 1354 | goto error_free_client_list; |
| 1355 | } |
| 1356 | } |
| 1357 | |
| 1358 | /* |
| 1359 | * Client list ownership transferred to the |
| 1360 | * notification_trigger_clients_ht. |
| 1361 | */ |
| 1362 | client_list = NULL; |
| 1363 | |
| 1364 | *cmd_result = LTTNG_OK; |
| 1365 | error_free_client_list: |
| 1366 | if (client_list) { |
| 1367 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 1368 | &client_list->list, node) { |
| 1369 | free(client_list_element); |
| 1370 | } |
| 1371 | free(client_list); |
| 1372 | } |
| 1373 | error_free_ht_element: |
| 1374 | free(trigger_ht_element); |
| 1375 | error: |
| 1376 | if (free_trigger) { |
| 1377 | struct lttng_action *action = lttng_trigger_get_action(trigger); |
| 1378 | |
| 1379 | lttng_condition_destroy(condition); |
| 1380 | lttng_action_destroy(action); |
| 1381 | lttng_trigger_destroy(trigger); |
| 1382 | } |
| 1383 | rcu_read_unlock(); |
| 1384 | return ret; |
| 1385 | } |
| 1386 | |
| 1387 | static |
| 1388 | int handle_notification_thread_command_unregister_trigger( |
| 1389 | struct notification_thread_state *state, |
| 1390 | struct lttng_trigger *trigger, |
| 1391 | enum lttng_error_code *_cmd_reply) |
| 1392 | { |
| 1393 | struct cds_lfht_iter iter; |
| 1394 | struct cds_lfht_node *node, *triggers_ht_node; |
| 1395 | struct lttng_channel_trigger_list *trigger_list; |
| 1396 | struct notification_client_list *client_list; |
| 1397 | struct notification_client_list_element *client_list_element, *tmp; |
| 1398 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; |
| 1399 | struct lttng_condition *condition = lttng_trigger_get_condition( |
| 1400 | trigger); |
| 1401 | struct lttng_action *action; |
| 1402 | enum lttng_error_code cmd_reply; |
| 1403 | |
| 1404 | rcu_read_lock(); |
| 1405 | |
| 1406 | cds_lfht_lookup(state->triggers_ht, |
| 1407 | lttng_condition_hash(condition), |
| 1408 | match_condition, |
| 1409 | condition, |
| 1410 | &iter); |
| 1411 | triggers_ht_node = cds_lfht_iter_get_node(&iter); |
| 1412 | if (!triggers_ht_node) { |
| 1413 | cmd_reply = LTTNG_ERR_TRIGGER_NOT_FOUND; |
| 1414 | goto end; |
| 1415 | } else { |
| 1416 | cmd_reply = LTTNG_OK; |
| 1417 | } |
| 1418 | |
| 1419 | /* Remove trigger from channel_triggers_ht. */ |
| 1420 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list, |
| 1421 | channel_triggers_ht_node) { |
| 1422 | struct lttng_trigger_list_element *trigger_element, *tmp; |
| 1423 | |
| 1424 | cds_list_for_each_entry_safe(trigger_element, tmp, |
| 1425 | &trigger_list->list, node) { |
| 1426 | struct lttng_condition *current_condition = |
| 1427 | lttng_trigger_get_condition( |
| 1428 | trigger_element->trigger); |
| 1429 | |
| 1430 | assert(current_condition); |
| 1431 | if (!lttng_condition_is_equal(condition, |
| 1432 | current_condition)) { |
| 1433 | continue; |
| 1434 | } |
| 1435 | |
| 1436 | DBG("[notification-thread] Removed trigger from channel_triggers_ht"); |
| 1437 | cds_list_del(&trigger_element->node); |
| 1438 | /* A trigger can only appear once per channel */ |
| 1439 | break; |
| 1440 | } |
| 1441 | } |
| 1442 | |
| 1443 | /* |
| 1444 | * Remove and release the client list from |
| 1445 | * notification_trigger_clients_ht. |
| 1446 | */ |
| 1447 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 1448 | lttng_condition_hash(condition), |
| 1449 | match_client_list, |
| 1450 | trigger, |
| 1451 | &iter); |
| 1452 | node = cds_lfht_iter_get_node(&iter); |
| 1453 | assert(node); |
| 1454 | client_list = caa_container_of(node, struct notification_client_list, |
| 1455 | notification_trigger_ht_node); |
| 1456 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 1457 | &client_list->list, node) { |
| 1458 | free(client_list_element); |
| 1459 | } |
| 1460 | cds_lfht_del(state->notification_trigger_clients_ht, node); |
| 1461 | free(client_list); |
| 1462 | |
| 1463 | /* Remove trigger from triggers_ht. */ |
| 1464 | trigger_ht_element = caa_container_of(triggers_ht_node, |
| 1465 | struct lttng_trigger_ht_element, node); |
| 1466 | cds_lfht_del(state->triggers_ht, triggers_ht_node); |
| 1467 | |
| 1468 | condition = lttng_trigger_get_condition(trigger_ht_element->trigger); |
| 1469 | lttng_condition_destroy(condition); |
| 1470 | action = lttng_trigger_get_action(trigger_ht_element->trigger); |
| 1471 | lttng_action_destroy(action); |
| 1472 | lttng_trigger_destroy(trigger_ht_element->trigger); |
| 1473 | free(trigger_ht_element); |
| 1474 | end: |
| 1475 | rcu_read_unlock(); |
| 1476 | if (_cmd_reply) { |
| 1477 | *_cmd_reply = cmd_reply; |
| 1478 | } |
| 1479 | return 0; |
| 1480 | } |
| 1481 | |
| 1482 | /* Returns 0 on success, 1 on exit requested, negative value on error. */ |
| 1483 | int handle_notification_thread_command( |
| 1484 | struct notification_thread_handle *handle, |
| 1485 | struct notification_thread_state *state) |
| 1486 | { |
| 1487 | int ret; |
| 1488 | uint64_t counter; |
| 1489 | struct notification_thread_command *cmd; |
| 1490 | |
| 1491 | /* Read the event pipe to put it back into a quiescent state. */ |
| 1492 | ret = read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter, |
| 1493 | sizeof(counter)); |
| 1494 | if (ret == -1) { |
| 1495 | goto error; |
| 1496 | } |
| 1497 | |
| 1498 | pthread_mutex_lock(&handle->cmd_queue.lock); |
| 1499 | cmd = cds_list_first_entry(&handle->cmd_queue.list, |
| 1500 | struct notification_thread_command, cmd_list_node); |
| 1501 | switch (cmd->type) { |
| 1502 | case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: |
| 1503 | DBG("[notification-thread] Received register trigger command"); |
| 1504 | ret = handle_notification_thread_command_register_trigger( |
| 1505 | state, cmd->parameters.trigger, |
| 1506 | &cmd->reply_code); |
| 1507 | break; |
| 1508 | case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: |
| 1509 | DBG("[notification-thread] Received unregister trigger command"); |
| 1510 | ret = handle_notification_thread_command_unregister_trigger( |
| 1511 | state, cmd->parameters.trigger, |
| 1512 | &cmd->reply_code); |
| 1513 | break; |
| 1514 | case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: |
| 1515 | DBG("[notification-thread] Received add channel command"); |
| 1516 | ret = handle_notification_thread_command_add_channel( |
| 1517 | state, |
| 1518 | cmd->parameters.add_channel.session.name, |
| 1519 | cmd->parameters.add_channel.session.uid, |
| 1520 | cmd->parameters.add_channel.session.gid, |
| 1521 | cmd->parameters.add_channel.channel.name, |
| 1522 | cmd->parameters.add_channel.channel.domain, |
| 1523 | cmd->parameters.add_channel.channel.key, |
| 1524 | cmd->parameters.add_channel.channel.capacity, |
| 1525 | &cmd->reply_code); |
| 1526 | break; |
| 1527 | case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: |
| 1528 | DBG("[notification-thread] Received remove channel command"); |
| 1529 | ret = handle_notification_thread_command_remove_channel( |
| 1530 | state, cmd->parameters.remove_channel.key, |
| 1531 | cmd->parameters.remove_channel.domain, |
| 1532 | &cmd->reply_code); |
| 1533 | break; |
| 1534 | case NOTIFICATION_COMMAND_TYPE_QUIT: |
| 1535 | DBG("[notification-thread] Received quit command"); |
| 1536 | cmd->reply_code = LTTNG_OK; |
| 1537 | ret = 1; |
| 1538 | goto end; |
| 1539 | default: |
| 1540 | ERR("[notification-thread] Unknown internal command received"); |
| 1541 | goto error_unlock; |
| 1542 | } |
| 1543 | |
| 1544 | if (ret) { |
| 1545 | goto error_unlock; |
| 1546 | } |
| 1547 | end: |
| 1548 | cds_list_del(&cmd->cmd_list_node); |
| 1549 | lttng_waiter_wake_up(&cmd->reply_waiter); |
| 1550 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
| 1551 | return ret; |
| 1552 | error_unlock: |
| 1553 | /* Wake-up and return a fatal error to the calling thread. */ |
| 1554 | lttng_waiter_wake_up(&cmd->reply_waiter); |
| 1555 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
| 1556 | cmd->reply_code = LTTNG_ERR_FATAL; |
| 1557 | error: |
| 1558 | /* Indicate a fatal error to the caller. */ |
| 1559 | return -1; |
| 1560 | } |
| 1561 | |
| 1562 | static |
| 1563 | unsigned long hash_client_socket(int socket) |
| 1564 | { |
| 1565 | return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed); |
| 1566 | } |
| 1567 | |
| 1568 | static |
| 1569 | int socket_set_non_blocking(int socket) |
| 1570 | { |
| 1571 | int ret, flags; |
| 1572 | |
| 1573 | /* Set the pipe as non-blocking. */ |
| 1574 | ret = fcntl(socket, F_GETFL, 0); |
| 1575 | if (ret == -1) { |
| 1576 | PERROR("fcntl get socket flags"); |
| 1577 | goto end; |
| 1578 | } |
| 1579 | flags = ret; |
| 1580 | |
| 1581 | ret = fcntl(socket, F_SETFL, flags | O_NONBLOCK); |
| 1582 | if (ret == -1) { |
| 1583 | PERROR("fcntl set O_NONBLOCK socket flag"); |
| 1584 | goto end; |
| 1585 | } |
| 1586 | DBG("Client socket (fd = %i) set as non-blocking", socket); |
| 1587 | end: |
| 1588 | return ret; |
| 1589 | } |
| 1590 | |
| 1591 | static |
| 1592 | int client_reset_inbound_state(struct notification_client *client) |
| 1593 | { |
| 1594 | int ret; |
| 1595 | |
| 1596 | ret = lttng_dynamic_buffer_set_size( |
| 1597 | &client->communication.inbound.buffer, 0); |
| 1598 | assert(!ret); |
| 1599 | |
| 1600 | client->communication.inbound.bytes_to_receive = |
| 1601 | sizeof(struct lttng_notification_channel_message); |
| 1602 | client->communication.inbound.msg_type = |
| 1603 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN; |
| 1604 | LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1); |
| 1605 | LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1); |
| 1606 | ret = lttng_dynamic_buffer_set_size( |
| 1607 | &client->communication.inbound.buffer, |
| 1608 | client->communication.inbound.bytes_to_receive); |
| 1609 | return ret; |
| 1610 | } |
| 1611 | |
| 1612 | int handle_notification_thread_client_connect( |
| 1613 | struct notification_thread_state *state) |
| 1614 | { |
| 1615 | int ret; |
| 1616 | struct notification_client *client; |
| 1617 | |
| 1618 | DBG("[notification-thread] Handling new notification channel client connection"); |
| 1619 | |
| 1620 | client = zmalloc(sizeof(*client)); |
| 1621 | if (!client) { |
| 1622 | /* Fatal error. */ |
| 1623 | ret = -1; |
| 1624 | goto error; |
| 1625 | } |
| 1626 | CDS_INIT_LIST_HEAD(&client->condition_list); |
| 1627 | lttng_dynamic_buffer_init(&client->communication.inbound.buffer); |
| 1628 | lttng_dynamic_buffer_init(&client->communication.outbound.buffer); |
| 1629 | client->communication.inbound.expect_creds = true; |
| 1630 | ret = client_reset_inbound_state(client); |
| 1631 | if (ret) { |
| 1632 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 1633 | ret = 0; |
| 1634 | goto error; |
| 1635 | } |
| 1636 | |
| 1637 | ret = lttcomm_accept_unix_sock(state->notification_channel_socket); |
| 1638 | if (ret < 0) { |
| 1639 | ERR("[notification-thread] Failed to accept new notification channel client connection"); |
| 1640 | ret = 0; |
| 1641 | goto error; |
| 1642 | } |
| 1643 | |
| 1644 | client->socket = ret; |
| 1645 | |
| 1646 | ret = socket_set_non_blocking(client->socket); |
| 1647 | if (ret) { |
| 1648 | ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking"); |
| 1649 | goto error; |
| 1650 | } |
| 1651 | |
| 1652 | ret = lttcomm_setsockopt_creds_unix_sock(client->socket); |
| 1653 | if (ret < 0) { |
| 1654 | ERR("[notification-thread] Failed to set socket options on new notification channel client socket"); |
| 1655 | ret = 0; |
| 1656 | goto error; |
| 1657 | } |
| 1658 | |
| 1659 | ret = lttng_poll_add(&state->events, client->socket, |
| 1660 | LPOLLIN | LPOLLERR | |
| 1661 | LPOLLHUP | LPOLLRDHUP); |
| 1662 | if (ret < 0) { |
| 1663 | ERR("[notification-thread] Failed to add notification channel client socket to poll set"); |
| 1664 | ret = 0; |
| 1665 | goto error; |
| 1666 | } |
| 1667 | DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", |
| 1668 | client->socket); |
| 1669 | |
| 1670 | rcu_read_lock(); |
| 1671 | cds_lfht_add(state->client_socket_ht, |
| 1672 | hash_client_socket(client->socket), |
| 1673 | &client->client_socket_ht_node); |
| 1674 | rcu_read_unlock(); |
| 1675 | |
| 1676 | return ret; |
| 1677 | error: |
| 1678 | notification_client_destroy(client, state); |
| 1679 | return ret; |
| 1680 | } |
| 1681 | |
| 1682 | int handle_notification_thread_client_disconnect( |
| 1683 | int client_socket, |
| 1684 | struct notification_thread_state *state) |
| 1685 | { |
| 1686 | int ret = 0; |
| 1687 | struct notification_client *client; |
| 1688 | |
| 1689 | rcu_read_lock(); |
| 1690 | DBG("[notification-thread] Closing client connection (socket fd = %i)", |
| 1691 | client_socket); |
| 1692 | client = get_client_from_socket(client_socket, state); |
| 1693 | if (!client) { |
| 1694 | /* Internal state corruption, fatal error. */ |
| 1695 | ERR("[notification-thread] Unable to find client (socket fd = %i)", |
| 1696 | client_socket); |
| 1697 | ret = -1; |
| 1698 | goto end; |
| 1699 | } |
| 1700 | |
| 1701 | ret = lttng_poll_del(&state->events, client_socket); |
| 1702 | if (ret) { |
| 1703 | ERR("[notification-thread] Failed to remove client socket from poll set"); |
| 1704 | } |
| 1705 | cds_lfht_del(state->client_socket_ht, |
| 1706 | &client->client_socket_ht_node); |
| 1707 | notification_client_destroy(client, state); |
| 1708 | end: |
| 1709 | rcu_read_unlock(); |
| 1710 | return ret; |
| 1711 | } |
| 1712 | |
| 1713 | int handle_notification_thread_client_disconnect_all( |
| 1714 | struct notification_thread_state *state) |
| 1715 | { |
| 1716 | struct cds_lfht_iter iter; |
| 1717 | struct notification_client *client; |
| 1718 | bool error_encoutered = false; |
| 1719 | |
| 1720 | rcu_read_lock(); |
| 1721 | DBG("[notification-thread] Closing all client connections"); |
| 1722 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, |
| 1723 | client_socket_ht_node) { |
| 1724 | int ret; |
| 1725 | |
| 1726 | ret = handle_notification_thread_client_disconnect( |
| 1727 | client->socket, state); |
| 1728 | if (ret) { |
| 1729 | error_encoutered = true; |
| 1730 | } |
| 1731 | } |
| 1732 | rcu_read_unlock(); |
| 1733 | return error_encoutered ? 1 : 0; |
| 1734 | } |
| 1735 | |
| 1736 | int handle_notification_thread_trigger_unregister_all( |
| 1737 | struct notification_thread_state *state) |
| 1738 | { |
| 1739 | bool error_occurred = false; |
| 1740 | struct cds_lfht_iter iter; |
| 1741 | struct lttng_trigger_ht_element *trigger_ht_element; |
| 1742 | |
| 1743 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, |
| 1744 | node) { |
| 1745 | int ret = handle_notification_thread_command_unregister_trigger( |
| 1746 | state, trigger_ht_element->trigger, NULL); |
| 1747 | if (ret) { |
| 1748 | error_occurred = true; |
| 1749 | } |
| 1750 | } |
| 1751 | return error_occurred ? -1 : 0; |
| 1752 | } |
| 1753 | |
| 1754 | static |
| 1755 | int client_flush_outgoing_queue(struct notification_client *client, |
| 1756 | struct notification_thread_state *state) |
| 1757 | { |
| 1758 | ssize_t ret; |
| 1759 | size_t to_send_count; |
| 1760 | |
| 1761 | assert(client->communication.outbound.buffer.size != 0); |
| 1762 | to_send_count = client->communication.outbound.buffer.size; |
| 1763 | DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", |
| 1764 | client->socket); |
| 1765 | |
| 1766 | ret = lttcomm_send_unix_sock_non_block(client->socket, |
| 1767 | client->communication.outbound.buffer.data, |
| 1768 | to_send_count); |
| 1769 | if ((ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) || |
| 1770 | (ret > 0 && ret < to_send_count)) { |
| 1771 | DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", |
| 1772 | client->socket); |
| 1773 | to_send_count -= max(ret, 0); |
| 1774 | |
| 1775 | memcpy(client->communication.outbound.buffer.data, |
| 1776 | client->communication.outbound.buffer.data + |
| 1777 | client->communication.outbound.buffer.size - to_send_count, |
| 1778 | to_send_count); |
| 1779 | ret = lttng_dynamic_buffer_set_size( |
| 1780 | &client->communication.outbound.buffer, |
| 1781 | to_send_count); |
| 1782 | if (ret) { |
| 1783 | goto error; |
| 1784 | } |
| 1785 | |
| 1786 | /* |
| 1787 | * We want to be notified whenever there is buffer space |
| 1788 | * available to send the rest of the payload. |
| 1789 | */ |
| 1790 | ret = lttng_poll_mod(&state->events, client->socket, |
| 1791 | CLIENT_POLL_MASK_IN_OUT); |
| 1792 | if (ret) { |
| 1793 | goto error; |
| 1794 | } |
| 1795 | } else if (ret < 0) { |
| 1796 | /* Generic error, disconnect the client. */ |
| 1797 | ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)", |
| 1798 | client->socket); |
| 1799 | ret = handle_notification_thread_client_disconnect( |
| 1800 | client->socket, state); |
| 1801 | if (ret) { |
| 1802 | goto error; |
| 1803 | } |
| 1804 | } else { |
| 1805 | /* No error and flushed the queue completely. */ |
| 1806 | ret = lttng_dynamic_buffer_set_size( |
| 1807 | &client->communication.outbound.buffer, 0); |
| 1808 | if (ret) { |
| 1809 | goto error; |
| 1810 | } |
| 1811 | ret = lttng_poll_mod(&state->events, client->socket, |
| 1812 | CLIENT_POLL_MASK_IN); |
| 1813 | if (ret) { |
| 1814 | goto error; |
| 1815 | } |
| 1816 | |
| 1817 | client->communication.outbound.queued_command_reply = false; |
| 1818 | client->communication.outbound.dropped_notification = false; |
| 1819 | } |
| 1820 | |
| 1821 | return 0; |
| 1822 | error: |
| 1823 | return -1; |
| 1824 | } |
| 1825 | |
| 1826 | static |
| 1827 | int client_send_command_reply(struct notification_client *client, |
| 1828 | struct notification_thread_state *state, |
| 1829 | enum lttng_notification_channel_status status) |
| 1830 | { |
| 1831 | int ret; |
| 1832 | struct lttng_notification_channel_command_reply reply = { |
| 1833 | .status = (int8_t) status, |
| 1834 | }; |
| 1835 | struct lttng_notification_channel_message msg = { |
| 1836 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY, |
| 1837 | .size = sizeof(reply), |
| 1838 | }; |
| 1839 | char buffer[sizeof(msg) + sizeof(reply)]; |
| 1840 | |
| 1841 | if (client->communication.outbound.queued_command_reply) { |
| 1842 | /* Protocol error. */ |
| 1843 | goto error; |
| 1844 | } |
| 1845 | |
| 1846 | memcpy(buffer, &msg, sizeof(msg)); |
| 1847 | memcpy(buffer + sizeof(msg), &reply, sizeof(reply)); |
| 1848 | DBG("[notification-thread] Send command reply (%i)", (int) status); |
| 1849 | |
| 1850 | /* Enqueue buffer to outgoing queue and flush it. */ |
| 1851 | ret = lttng_dynamic_buffer_append( |
| 1852 | &client->communication.outbound.buffer, |
| 1853 | buffer, sizeof(buffer)); |
| 1854 | if (ret) { |
| 1855 | goto error; |
| 1856 | } |
| 1857 | |
| 1858 | ret = client_flush_outgoing_queue(client, state); |
| 1859 | if (ret) { |
| 1860 | goto error; |
| 1861 | } |
| 1862 | |
| 1863 | if (client->communication.outbound.buffer.size != 0) { |
| 1864 | /* Queue could not be emptied. */ |
| 1865 | client->communication.outbound.queued_command_reply = true; |
| 1866 | } |
| 1867 | |
| 1868 | return 0; |
| 1869 | error: |
| 1870 | return -1; |
| 1871 | } |
| 1872 | |
| 1873 | static |
| 1874 | int client_dispatch_message(struct notification_client *client, |
| 1875 | struct notification_thread_state *state) |
| 1876 | { |
| 1877 | int ret = 0; |
| 1878 | |
| 1879 | if (client->communication.inbound.msg_type != |
| 1880 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE && |
| 1881 | client->communication.inbound.msg_type != |
| 1882 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN && |
| 1883 | !client->validated) { |
| 1884 | WARN("[notification-thread] client attempted a command before handshake"); |
| 1885 | ret = -1; |
| 1886 | goto end; |
| 1887 | } |
| 1888 | |
| 1889 | switch (client->communication.inbound.msg_type) { |
| 1890 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN: |
| 1891 | { |
| 1892 | /* |
| 1893 | * Receiving message header. The function will be called again |
| 1894 | * once the rest of the message as been received and can be |
| 1895 | * interpreted. |
| 1896 | */ |
| 1897 | const struct lttng_notification_channel_message *msg; |
| 1898 | |
| 1899 | assert(sizeof(*msg) == |
| 1900 | client->communication.inbound.buffer.size); |
| 1901 | msg = (const struct lttng_notification_channel_message *) |
| 1902 | client->communication.inbound.buffer.data; |
| 1903 | |
| 1904 | if (msg->size == 0 || msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { |
| 1905 | ERR("[notification-thread] Invalid notification channel message: length = %u", msg->size); |
| 1906 | ret = -1; |
| 1907 | goto end; |
| 1908 | } |
| 1909 | |
| 1910 | switch (msg->type) { |
| 1911 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: |
| 1912 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: |
| 1913 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: |
| 1914 | break; |
| 1915 | default: |
| 1916 | ret = -1; |
| 1917 | ERR("[notification-thread] Invalid notification channel message: unexpected message type"); |
| 1918 | goto end; |
| 1919 | } |
| 1920 | |
| 1921 | client->communication.inbound.bytes_to_receive = msg->size; |
| 1922 | client->communication.inbound.msg_type = |
| 1923 | (enum lttng_notification_channel_message_type) msg->type; |
| 1924 | ret = lttng_dynamic_buffer_set_size( |
| 1925 | &client->communication.inbound.buffer, msg->size); |
| 1926 | if (ret) { |
| 1927 | goto end; |
| 1928 | } |
| 1929 | break; |
| 1930 | } |
| 1931 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: |
| 1932 | { |
| 1933 | struct lttng_notification_channel_command_handshake *handshake_client; |
| 1934 | struct lttng_notification_channel_command_handshake handshake_reply = { |
| 1935 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, |
| 1936 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, |
| 1937 | }; |
| 1938 | struct lttng_notification_channel_message msg_header = { |
| 1939 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, |
| 1940 | .size = sizeof(handshake_reply), |
| 1941 | }; |
| 1942 | enum lttng_notification_channel_status status = |
| 1943 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 1944 | char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)]; |
| 1945 | |
| 1946 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); |
| 1947 | memcpy(send_buffer + sizeof(msg_header), &handshake_reply, |
| 1948 | sizeof(handshake_reply)); |
| 1949 | |
| 1950 | handshake_client = |
| 1951 | (struct lttng_notification_channel_command_handshake *) |
| 1952 | client->communication.inbound.buffer.data; |
| 1953 | client->major = handshake_client->major; |
| 1954 | client->minor = handshake_client->minor; |
| 1955 | if (!client->communication.inbound.creds_received) { |
| 1956 | ERR("[notification-thread] No credentials received from client"); |
| 1957 | ret = -1; |
| 1958 | goto end; |
| 1959 | } |
| 1960 | |
| 1961 | client->uid = LTTNG_SOCK_GET_UID_CRED( |
| 1962 | &client->communication.inbound.creds); |
| 1963 | client->gid = LTTNG_SOCK_GET_GID_CRED( |
| 1964 | &client->communication.inbound.creds); |
| 1965 | DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", |
| 1966 | client->uid, client->gid, (int) client->major, |
| 1967 | (int) client->minor); |
| 1968 | |
| 1969 | if (handshake_client->major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { |
| 1970 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION; |
| 1971 | } |
| 1972 | |
| 1973 | ret = lttng_dynamic_buffer_append(&client->communication.outbound.buffer, |
| 1974 | send_buffer, sizeof(send_buffer)); |
| 1975 | if (ret) { |
| 1976 | ERR("[notification-thread] Failed to send protocol version to notification channel client"); |
| 1977 | goto end; |
| 1978 | } |
| 1979 | |
| 1980 | ret = client_flush_outgoing_queue(client, state); |
| 1981 | if (ret) { |
| 1982 | goto end; |
| 1983 | } |
| 1984 | |
| 1985 | ret = client_send_command_reply(client, state, status); |
| 1986 | if (ret) { |
| 1987 | ERR("[notification-thread] Failed to send reply to notification channel client"); |
| 1988 | goto end; |
| 1989 | } |
| 1990 | |
| 1991 | /* Set reception state to receive the next message header. */ |
| 1992 | ret = client_reset_inbound_state(client); |
| 1993 | if (ret) { |
| 1994 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 1995 | goto end; |
| 1996 | } |
| 1997 | client->validated = true; |
| 1998 | break; |
| 1999 | } |
| 2000 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: |
| 2001 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: |
| 2002 | { |
| 2003 | struct lttng_condition *condition; |
| 2004 | enum lttng_notification_channel_status status = |
| 2005 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; |
| 2006 | const struct lttng_buffer_view condition_view = |
| 2007 | lttng_buffer_view_from_dynamic_buffer( |
| 2008 | &client->communication.inbound.buffer, |
| 2009 | 0, -1); |
| 2010 | size_t expected_condition_size = |
| 2011 | client->communication.inbound.buffer.size; |
| 2012 | |
| 2013 | ret = lttng_condition_create_from_buffer(&condition_view, |
| 2014 | &condition); |
| 2015 | if (ret != expected_condition_size) { |
| 2016 | ERR("[notification-thread] Malformed condition received from client"); |
| 2017 | goto end; |
| 2018 | } |
| 2019 | |
| 2020 | if (client->communication.inbound.msg_type == |
| 2021 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { |
| 2022 | ret = notification_thread_client_subscribe(client, |
| 2023 | condition, state, &status); |
| 2024 | } else { |
| 2025 | ret = notification_thread_client_unsubscribe(client, |
| 2026 | condition, state, &status); |
| 2027 | } |
| 2028 | if (ret) { |
| 2029 | goto end; |
| 2030 | } |
| 2031 | |
| 2032 | ret = client_send_command_reply(client, state, status); |
| 2033 | if (ret) { |
| 2034 | ERR("[notification-thread] Failed to send reply to notification channel client"); |
| 2035 | goto end; |
| 2036 | } |
| 2037 | |
| 2038 | /* Set reception state to receive the next message header. */ |
| 2039 | ret = client_reset_inbound_state(client); |
| 2040 | if (ret) { |
| 2041 | ERR("[notification-thread] Failed to reset client communication's inbound state"); |
| 2042 | goto end; |
| 2043 | } |
| 2044 | break; |
| 2045 | } |
| 2046 | default: |
| 2047 | abort(); |
| 2048 | } |
| 2049 | end: |
| 2050 | return ret; |
| 2051 | } |
| 2052 | |
| 2053 | /* Incoming data from client. */ |
| 2054 | int handle_notification_thread_client_in( |
| 2055 | struct notification_thread_state *state, int socket) |
| 2056 | { |
| 2057 | int ret = 0; |
| 2058 | struct notification_client *client; |
| 2059 | ssize_t recv_ret; |
| 2060 | size_t offset; |
| 2061 | |
| 2062 | client = get_client_from_socket(socket, state); |
| 2063 | if (!client) { |
| 2064 | /* Internal error, abort. */ |
| 2065 | ret = -1; |
| 2066 | goto end; |
| 2067 | } |
| 2068 | |
| 2069 | offset = client->communication.inbound.buffer.size - |
| 2070 | client->communication.inbound.bytes_to_receive; |
| 2071 | if (client->communication.inbound.expect_creds) { |
| 2072 | recv_ret = lttcomm_recv_creds_unix_sock(socket, |
| 2073 | client->communication.inbound.buffer.data + offset, |
| 2074 | client->communication.inbound.bytes_to_receive, |
| 2075 | &client->communication.inbound.creds); |
| 2076 | if (recv_ret > 0) { |
| 2077 | client->communication.inbound.expect_creds = false; |
| 2078 | client->communication.inbound.creds_received = true; |
| 2079 | } |
| 2080 | } else { |
| 2081 | recv_ret = lttcomm_recv_unix_sock_non_block(socket, |
| 2082 | client->communication.inbound.buffer.data + offset, |
| 2083 | client->communication.inbound.bytes_to_receive); |
| 2084 | } |
| 2085 | if (recv_ret < 0) { |
| 2086 | goto error_disconnect_client; |
| 2087 | } |
| 2088 | |
| 2089 | client->communication.inbound.bytes_to_receive -= recv_ret; |
| 2090 | if (client->communication.inbound.bytes_to_receive == 0) { |
| 2091 | ret = client_dispatch_message(client, state); |
| 2092 | if (ret) { |
| 2093 | /* |
| 2094 | * Only returns an error if this client must be |
| 2095 | * disconnected. |
| 2096 | */ |
| 2097 | goto error_disconnect_client; |
| 2098 | } |
| 2099 | } else { |
| 2100 | goto end; |
| 2101 | } |
| 2102 | end: |
| 2103 | return ret; |
| 2104 | error_disconnect_client: |
| 2105 | ret = handle_notification_thread_client_disconnect(socket, state); |
| 2106 | return ret; |
| 2107 | } |
| 2108 | |
| 2109 | /* Client ready to receive outgoing data. */ |
| 2110 | int handle_notification_thread_client_out( |
| 2111 | struct notification_thread_state *state, int socket) |
| 2112 | { |
| 2113 | int ret; |
| 2114 | struct notification_client *client; |
| 2115 | |
| 2116 | client = get_client_from_socket(socket, state); |
| 2117 | if (!client) { |
| 2118 | /* Internal error, abort. */ |
| 2119 | ret = -1; |
| 2120 | goto end; |
| 2121 | } |
| 2122 | |
| 2123 | ret = client_flush_outgoing_queue(client, state); |
| 2124 | if (ret) { |
| 2125 | goto end; |
| 2126 | } |
| 2127 | end: |
| 2128 | return ret; |
| 2129 | } |
| 2130 | |
| 2131 | static |
| 2132 | bool evaluate_buffer_usage_condition(struct lttng_condition *condition, |
| 2133 | struct channel_state_sample *sample, uint64_t buffer_capacity) |
| 2134 | { |
| 2135 | bool result = false; |
| 2136 | uint64_t threshold; |
| 2137 | enum lttng_condition_type condition_type; |
| 2138 | struct lttng_condition_buffer_usage *use_condition = container_of( |
| 2139 | condition, struct lttng_condition_buffer_usage, |
| 2140 | parent); |
| 2141 | |
| 2142 | if (!sample) { |
| 2143 | goto end; |
| 2144 | } |
| 2145 | |
| 2146 | if (use_condition->threshold_bytes.set) { |
| 2147 | threshold = use_condition->threshold_bytes.value; |
| 2148 | } else { |
| 2149 | /* |
| 2150 | * Threshold was expressed as a ratio. |
| 2151 | * |
| 2152 | * TODO the threshold (in bytes) of conditions expressed |
| 2153 | * as a ratio of total buffer size could be cached to |
| 2154 | * forego this double-multiplication or it could be performed |
| 2155 | * as fixed-point math. |
| 2156 | * |
| 2157 | * Note that caching should accomodate the case where the |
| 2158 | * condition applies to multiple channels (i.e. don't assume |
| 2159 | * that all channels matching my_chann* have the same size...) |
| 2160 | */ |
| 2161 | threshold = (uint64_t) (use_condition->threshold_ratio.value * |
| 2162 | (double) buffer_capacity); |
| 2163 | } |
| 2164 | |
| 2165 | condition_type = lttng_condition_get_type(condition); |
| 2166 | if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) { |
| 2167 | DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, |
| 2168 | threshold, sample->highest_usage); |
| 2169 | |
| 2170 | /* |
| 2171 | * The low condition should only be triggered once _all_ of the |
| 2172 | * streams in a channel have gone below the "low" threshold. |
| 2173 | */ |
| 2174 | if (sample->highest_usage <= threshold) { |
| 2175 | result = true; |
| 2176 | } |
| 2177 | } else { |
| 2178 | DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, |
| 2179 | threshold, sample->highest_usage); |
| 2180 | |
| 2181 | /* |
| 2182 | * For high buffer usage scenarios, we want to trigger whenever |
| 2183 | * _any_ of the streams has reached the "high" threshold. |
| 2184 | */ |
| 2185 | if (sample->highest_usage >= threshold) { |
| 2186 | result = true; |
| 2187 | } |
| 2188 | } |
| 2189 | end: |
| 2190 | return result; |
| 2191 | } |
| 2192 | |
| 2193 | static |
| 2194 | int evaluate_condition(struct lttng_condition *condition, |
| 2195 | struct lttng_evaluation **evaluation, |
| 2196 | struct notification_thread_state *state, |
| 2197 | struct channel_state_sample *previous_sample, |
| 2198 | struct channel_state_sample *latest_sample, |
| 2199 | uint64_t buffer_capacity) |
| 2200 | { |
| 2201 | int ret = 0; |
| 2202 | enum lttng_condition_type condition_type; |
| 2203 | bool previous_sample_result; |
| 2204 | bool latest_sample_result; |
| 2205 | |
| 2206 | condition_type = lttng_condition_get_type(condition); |
| 2207 | /* No other condition type supported for the moment. */ |
| 2208 | assert(condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW || |
| 2209 | condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH); |
| 2210 | |
| 2211 | previous_sample_result = evaluate_buffer_usage_condition(condition, |
| 2212 | previous_sample, buffer_capacity); |
| 2213 | latest_sample_result = evaluate_buffer_usage_condition(condition, |
| 2214 | latest_sample, buffer_capacity); |
| 2215 | |
| 2216 | if (!latest_sample_result || |
| 2217 | (previous_sample_result == latest_sample_result)) { |
| 2218 | /* |
| 2219 | * Only trigger on a condition evaluation transition. |
| 2220 | * |
| 2221 | * NOTE: This edge-triggered logic may not be appropriate for |
| 2222 | * future condition types. |
| 2223 | */ |
| 2224 | goto end; |
| 2225 | } |
| 2226 | |
| 2227 | if (evaluation && latest_sample_result) { |
| 2228 | *evaluation = lttng_evaluation_buffer_usage_create( |
| 2229 | condition_type, |
| 2230 | latest_sample->highest_usage, |
| 2231 | buffer_capacity); |
| 2232 | if (!*evaluation) { |
| 2233 | ret = -1; |
| 2234 | goto end; |
| 2235 | } |
| 2236 | } |
| 2237 | end: |
| 2238 | return ret; |
| 2239 | } |
| 2240 | |
| 2241 | static |
| 2242 | int client_enqueue_dropped_notification(struct notification_client *client, |
| 2243 | struct notification_thread_state *state) |
| 2244 | { |
| 2245 | int ret; |
| 2246 | struct lttng_notification_channel_message msg = { |
| 2247 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED, |
| 2248 | .size = 0, |
| 2249 | }; |
| 2250 | |
| 2251 | ret = lttng_dynamic_buffer_append( |
| 2252 | &client->communication.outbound.buffer, &msg, |
| 2253 | sizeof(msg)); |
| 2254 | return ret; |
| 2255 | } |
| 2256 | |
| 2257 | static |
| 2258 | int send_evaluation_to_clients(struct lttng_trigger *trigger, |
| 2259 | struct lttng_evaluation *evaluation, |
| 2260 | struct notification_client_list* client_list, |
| 2261 | struct notification_thread_state *state, |
| 2262 | uid_t channel_uid, gid_t channel_gid) |
| 2263 | { |
| 2264 | int ret = 0; |
| 2265 | struct lttng_dynamic_buffer msg_buffer; |
| 2266 | struct notification_client_list_element *client_list_element, *tmp; |
| 2267 | struct lttng_notification *notification; |
| 2268 | struct lttng_condition *condition; |
| 2269 | ssize_t expected_notification_size, notification_size; |
| 2270 | struct lttng_notification_channel_message msg; |
| 2271 | |
| 2272 | lttng_dynamic_buffer_init(&msg_buffer); |
| 2273 | |
| 2274 | condition = lttng_trigger_get_condition(trigger); |
| 2275 | assert(condition); |
| 2276 | |
| 2277 | notification = lttng_notification_create(condition, evaluation); |
| 2278 | if (!notification) { |
| 2279 | ret = -1; |
| 2280 | goto end; |
| 2281 | } |
| 2282 | |
| 2283 | expected_notification_size = lttng_notification_serialize(notification, |
| 2284 | NULL); |
| 2285 | if (expected_notification_size < 0) { |
| 2286 | ERR("[notification-thread] Failed to get size of serialized notification"); |
| 2287 | ret = -1; |
| 2288 | goto end; |
| 2289 | } |
| 2290 | |
| 2291 | msg.type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION; |
| 2292 | msg.size = (uint32_t) expected_notification_size; |
| 2293 | ret = lttng_dynamic_buffer_append(&msg_buffer, &msg, sizeof(msg)); |
| 2294 | if (ret) { |
| 2295 | goto end; |
| 2296 | } |
| 2297 | |
| 2298 | ret = lttng_dynamic_buffer_set_size(&msg_buffer, |
| 2299 | msg_buffer.size + expected_notification_size); |
| 2300 | if (ret) { |
| 2301 | goto end; |
| 2302 | } |
| 2303 | |
| 2304 | notification_size = lttng_notification_serialize(notification, |
| 2305 | msg_buffer.data + sizeof(msg)); |
| 2306 | if (notification_size != expected_notification_size) { |
| 2307 | ERR("[notification-thread] Failed to serialize notification"); |
| 2308 | ret = -1; |
| 2309 | goto end; |
| 2310 | } |
| 2311 | |
| 2312 | cds_list_for_each_entry_safe(client_list_element, tmp, |
| 2313 | &client_list->list, node) { |
| 2314 | struct notification_client *client = |
| 2315 | client_list_element->client; |
| 2316 | |
| 2317 | if (client->uid != channel_uid && client->gid != channel_gid && |
| 2318 | client->uid != 0) { |
| 2319 | /* Client is not allowed to monitor this channel. */ |
| 2320 | DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this channel"); |
| 2321 | continue; |
| 2322 | } |
| 2323 | |
| 2324 | DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", |
| 2325 | client->socket, msg_buffer.size); |
| 2326 | if (client->communication.outbound.buffer.size) { |
| 2327 | /* |
| 2328 | * Outgoing data is already buffered for this client; |
| 2329 | * drop the notification and enqueue a "dropped |
| 2330 | * notification" message if this is the first dropped |
| 2331 | * notification since the socket spilled-over to the |
| 2332 | * queue. |
| 2333 | */ |
| 2334 | DBG("[notification-thread] Dropping notification addressed to client (socket fd = %i)", |
| 2335 | client->socket); |
| 2336 | if (!client->communication.outbound.dropped_notification) { |
| 2337 | client->communication.outbound.dropped_notification = true; |
| 2338 | ret = client_enqueue_dropped_notification( |
| 2339 | client, state); |
| 2340 | if (ret) { |
| 2341 | goto end; |
| 2342 | } |
| 2343 | } |
| 2344 | continue; |
| 2345 | } |
| 2346 | |
| 2347 | ret = lttng_dynamic_buffer_append_buffer( |
| 2348 | &client->communication.outbound.buffer, |
| 2349 | &msg_buffer); |
| 2350 | if (ret) { |
| 2351 | goto end; |
| 2352 | } |
| 2353 | |
| 2354 | ret = client_flush_outgoing_queue(client, state); |
| 2355 | if (ret) { |
| 2356 | goto end; |
| 2357 | } |
| 2358 | } |
| 2359 | ret = 0; |
| 2360 | end: |
| 2361 | lttng_notification_destroy(notification); |
| 2362 | lttng_dynamic_buffer_reset(&msg_buffer); |
| 2363 | return ret; |
| 2364 | } |
| 2365 | |
| 2366 | int handle_notification_thread_channel_sample( |
| 2367 | struct notification_thread_state *state, int pipe, |
| 2368 | enum lttng_domain_type domain) |
| 2369 | { |
| 2370 | int ret = 0; |
| 2371 | struct lttcomm_consumer_channel_monitor_msg sample_msg; |
| 2372 | struct channel_state_sample previous_sample, latest_sample; |
| 2373 | struct channel_info *channel_info; |
| 2374 | struct cds_lfht_node *node; |
| 2375 | struct cds_lfht_iter iter; |
| 2376 | struct lttng_channel_trigger_list *trigger_list; |
| 2377 | struct lttng_trigger_list_element *trigger_list_element; |
| 2378 | bool previous_sample_available = false; |
| 2379 | |
| 2380 | /* |
| 2381 | * The monitoring pipe only holds messages smaller than PIPE_BUF, |
| 2382 | * ensuring that read/write of sampling messages are atomic. |
| 2383 | */ |
| 2384 | ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg)); |
| 2385 | if (ret != sizeof(sample_msg)) { |
| 2386 | ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)", |
| 2387 | pipe); |
| 2388 | ret = -1; |
| 2389 | goto end; |
| 2390 | } |
| 2391 | |
| 2392 | ret = 0; |
| 2393 | latest_sample.key.key = sample_msg.key; |
| 2394 | latest_sample.key.domain = domain; |
| 2395 | latest_sample.highest_usage = sample_msg.highest; |
| 2396 | latest_sample.lowest_usage = sample_msg.lowest; |
| 2397 | |
| 2398 | rcu_read_lock(); |
| 2399 | |
| 2400 | /* Retrieve the channel's informations */ |
| 2401 | cds_lfht_lookup(state->channels_ht, |
| 2402 | hash_channel_key(&latest_sample.key), |
| 2403 | match_channel_info, |
| 2404 | &latest_sample.key, |
| 2405 | &iter); |
| 2406 | node = cds_lfht_iter_get_node(&iter); |
| 2407 | if (caa_unlikely(!node)) { |
| 2408 | /* |
| 2409 | * Not an error since the consumer can push a sample to the pipe |
| 2410 | * and the rest of the session daemon could notify us of the |
| 2411 | * channel's destruction before we get a chance to process that |
| 2412 | * sample. |
| 2413 | */ |
| 2414 | DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", |
| 2415 | latest_sample.key.key, |
| 2416 | domain == LTTNG_DOMAIN_KERNEL ? "kernel" : |
| 2417 | "user space"); |
| 2418 | goto end_unlock; |
| 2419 | } |
| 2420 | channel_info = caa_container_of(node, struct channel_info, |
| 2421 | channels_ht_node); |
| 2422 | DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64")", |
| 2423 | channel_info->name, |
| 2424 | latest_sample.key.key, |
| 2425 | channel_info->session_info->name, |
| 2426 | latest_sample.highest_usage, |
| 2427 | latest_sample.lowest_usage); |
| 2428 | |
| 2429 | /* Retrieve the channel's last sample, if it exists, and update it. */ |
| 2430 | cds_lfht_lookup(state->channel_state_ht, |
| 2431 | hash_channel_key(&latest_sample.key), |
| 2432 | match_channel_state_sample, |
| 2433 | &latest_sample.key, |
| 2434 | &iter); |
| 2435 | node = cds_lfht_iter_get_node(&iter); |
| 2436 | if (caa_likely(node)) { |
| 2437 | struct channel_state_sample *stored_sample; |
| 2438 | |
| 2439 | /* Update the sample stored. */ |
| 2440 | stored_sample = caa_container_of(node, |
| 2441 | struct channel_state_sample, |
| 2442 | channel_state_ht_node); |
| 2443 | memcpy(&previous_sample, stored_sample, |
| 2444 | sizeof(previous_sample)); |
| 2445 | stored_sample->highest_usage = latest_sample.highest_usage; |
| 2446 | stored_sample->lowest_usage = latest_sample.lowest_usage; |
| 2447 | previous_sample_available = true; |
| 2448 | } else { |
| 2449 | /* |
| 2450 | * This is the channel's first sample, allocate space for and |
| 2451 | * store the new sample. |
| 2452 | */ |
| 2453 | struct channel_state_sample *stored_sample; |
| 2454 | |
| 2455 | stored_sample = zmalloc(sizeof(*stored_sample)); |
| 2456 | if (!stored_sample) { |
| 2457 | ret = -1; |
| 2458 | goto end_unlock; |
| 2459 | } |
| 2460 | |
| 2461 | memcpy(stored_sample, &latest_sample, sizeof(*stored_sample)); |
| 2462 | cds_lfht_node_init(&stored_sample->channel_state_ht_node); |
| 2463 | cds_lfht_add(state->channel_state_ht, |
| 2464 | hash_channel_key(&stored_sample->key), |
| 2465 | &stored_sample->channel_state_ht_node); |
| 2466 | } |
| 2467 | |
| 2468 | /* Find triggers associated with this channel. */ |
| 2469 | cds_lfht_lookup(state->channel_triggers_ht, |
| 2470 | hash_channel_key(&latest_sample.key), |
| 2471 | match_channel_trigger_list, |
| 2472 | &latest_sample.key, |
| 2473 | &iter); |
| 2474 | node = cds_lfht_iter_get_node(&iter); |
| 2475 | if (caa_likely(!node)) { |
| 2476 | goto end_unlock; |
| 2477 | } |
| 2478 | |
| 2479 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, |
| 2480 | channel_triggers_ht_node); |
| 2481 | cds_list_for_each_entry(trigger_list_element, &trigger_list->list, |
| 2482 | node) { |
| 2483 | struct lttng_condition *condition; |
| 2484 | struct lttng_action *action; |
| 2485 | struct lttng_trigger *trigger; |
| 2486 | struct notification_client_list *client_list; |
| 2487 | struct lttng_evaluation *evaluation = NULL; |
| 2488 | |
| 2489 | trigger = trigger_list_element->trigger; |
| 2490 | condition = lttng_trigger_get_condition(trigger); |
| 2491 | assert(condition); |
| 2492 | action = lttng_trigger_get_action(trigger); |
| 2493 | |
| 2494 | /* Notify actions are the only type currently supported. */ |
| 2495 | assert(lttng_action_get_type(action) == |
| 2496 | LTTNG_ACTION_TYPE_NOTIFY); |
| 2497 | |
| 2498 | /* |
| 2499 | * Check if any client is subscribed to the result of this |
| 2500 | * evaluation. |
| 2501 | */ |
| 2502 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
| 2503 | lttng_condition_hash(condition), |
| 2504 | match_client_list, |
| 2505 | trigger, |
| 2506 | &iter); |
| 2507 | node = cds_lfht_iter_get_node(&iter); |
| 2508 | assert(node); |
| 2509 | |
| 2510 | client_list = caa_container_of(node, |
| 2511 | struct notification_client_list, |
| 2512 | notification_trigger_ht_node); |
| 2513 | if (cds_list_empty(&client_list->list)) { |
| 2514 | /* |
| 2515 | * No clients interested in the evaluation's result, |
| 2516 | * skip it. |
| 2517 | */ |
| 2518 | continue; |
| 2519 | } |
| 2520 | |
| 2521 | ret = evaluate_condition(condition, &evaluation, state, |
| 2522 | previous_sample_available ? &previous_sample : NULL, |
| 2523 | &latest_sample, channel_info->capacity); |
| 2524 | if (ret) { |
| 2525 | goto end_unlock; |
| 2526 | } |
| 2527 | |
| 2528 | if (!evaluation) { |
| 2529 | continue; |
| 2530 | } |
| 2531 | |
| 2532 | /* Dispatch evaluation result to all clients. */ |
| 2533 | ret = send_evaluation_to_clients(trigger_list_element->trigger, |
| 2534 | evaluation, client_list, state, |
| 2535 | channel_info->session_info->uid, |
| 2536 | channel_info->session_info->gid); |
| 2537 | lttng_evaluation_destroy(evaluation); |
| 2538 | if (caa_unlikely(ret)) { |
| 2539 | goto end_unlock; |
| 2540 | } |
| 2541 | } |
| 2542 | end_unlock: |
| 2543 | rcu_read_unlock(); |
| 2544 | end: |
| 2545 | return ret; |
| 2546 | } |