src/bin/lttng-sessiond/notification-thread.c

   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 <lttng/trigger/trigger.h>
  20 #include <lttng/notification/channel-internal.h>
  21 #include <lttng/notification/notification-internal.h>
  22 #include <lttng/condition/condition-internal.h>
  23 #include <lttng/condition/buffer-usage-internal.h>
  24 #include <common/error.h>
  25 #include <common/config/session-config.h>
  26 #include <common/defaults.h>
  27 #include <common/utils.h>
  28 #include <common/align.h>
  29 #include <common/time.h>
  30 #include <sys/eventfd.h>
  31 #include <sys/stat.h>
  32 #include <time.h>
  33 #include <signal.h>
  34
  35 #include "notification-thread.h"
  36 #include "notification-thread-events.h"
  37 #include "notification-thread-commands.h"
  38 #include "lttng-sessiond.h"
  39 #include "health-sessiond.h"
  40
  41 #include <urcu.h>
  42 #include <urcu/list.h>
  43 #include <urcu/rculfhash.h>
  44
  45 /*
  46  * Destroy the thread data previously created by the init function.
  47  */
  48 void notification_thread_handle_destroy(
  49                 struct notification_thread_handle *handle)
  50 {
  51         int ret;
  52
  53         if (!handle) {
  54                 goto end;
  55         }
  56
  57         assert(cds_list_empty(&handle->cmd_queue.list));
  58         pthread_mutex_destroy(&handle->cmd_queue.lock);
  59
  60         if (handle->cmd_queue.event_pipe) {
  61                 lttng_pipe_destroy(handle->cmd_queue.event_pipe);
  62         }
  63         if (handle->channel_monitoring_pipes.ust32_consumer >= 0) {
  64                 ret = close(handle->channel_monitoring_pipes.ust32_consumer);
  65                 if (ret) {
  66                         PERROR("close 32-bit consumer channel monitoring pipe");
  67                 }
  68         }
  69         if (handle->channel_monitoring_pipes.ust64_consumer >= 0) {
  70                 ret = close(handle->channel_monitoring_pipes.ust64_consumer);
  71                 if (ret) {
  72                         PERROR("close 64-bit consumer channel monitoring pipe");
  73                 }
  74         }
  75         if (handle->channel_monitoring_pipes.kernel_consumer >= 0) {
  76                 ret = close(handle->channel_monitoring_pipes.kernel_consumer);
  77                 if (ret) {
  78                         PERROR("close kernel consumer channel monitoring pipe");
  79                 }
  80         }
  81 end:
  82         free(handle);
  83 }
  84
  85 struct notification_thread_handle *notification_thread_handle_create(
  86                 struct lttng_pipe *ust32_channel_monitor_pipe,
  87                 struct lttng_pipe *ust64_channel_monitor_pipe,
  88                 struct lttng_pipe *kernel_channel_monitor_pipe)
  89 {
  90         int ret;
  91         struct notification_thread_handle *handle;
  92         struct lttng_pipe *event_pipe = NULL;
  93
  94         handle = zmalloc(sizeof(*handle));
  95         if (!handle) {
  96                 goto end;
  97         }
  98
  99         event_pipe = lttng_pipe_open(FD_CLOEXEC);
 100         if (!event_pipe) {
 101                 ERR("event_pipe creation");
 102                 goto error;
 103         }
 104
 105         handle->cmd_queue.event_pipe = event_pipe;
 106         event_pipe = NULL;
 107
 108         CDS_INIT_LIST_HEAD(&handle->cmd_queue.list);
 109         ret = pthread_mutex_init(&handle->cmd_queue.lock, NULL);
 110         if (ret) {
 111                 goto error;
 112         }
 113
 114         if (ust32_channel_monitor_pipe) {
 115                 handle->channel_monitoring_pipes.ust32_consumer =
 116                                 lttng_pipe_release_readfd(
 117                                         ust32_channel_monitor_pipe);
 118                 if (handle->channel_monitoring_pipes.ust32_consumer < 0) {
 119                         goto error;
 120                 }
 121         } else {
 122                 handle->channel_monitoring_pipes.ust32_consumer = -1;
 123         }
 124         if (ust64_channel_monitor_pipe) {
 125                 handle->channel_monitoring_pipes.ust64_consumer =
 126                                 lttng_pipe_release_readfd(
 127                                         ust64_channel_monitor_pipe);
 128                 if (handle->channel_monitoring_pipes.ust64_consumer < 0) {
 129                         goto error;
 130                 }
 131         } else {
 132                 handle->channel_monitoring_pipes.ust64_consumer = -1;
 133         }
 134         if (kernel_channel_monitor_pipe) {
 135                 handle->channel_monitoring_pipes.kernel_consumer =
 136                                 lttng_pipe_release_readfd(
 137                                         kernel_channel_monitor_pipe);
 138                 if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
 139                         goto error;
 140                 }
 141         } else {
 142                 handle->channel_monitoring_pipes.kernel_consumer = -1;
 143         }
 144 end:
 145         return handle;
 146 error:
 147         lttng_pipe_destroy(event_pipe);
 148         notification_thread_handle_destroy(handle);
 149         return NULL;
 150 }
 151
 152 static
 153 char *get_notification_channel_sock_path(void)
 154 {
 155         int ret;
 156         bool is_root = !getuid();
 157         char *sock_path;
 158
 159         sock_path = zmalloc(LTTNG_PATH_MAX);
 160         if (!sock_path) {
 161                 goto error;
 162         }
 163
 164         if (is_root) {
 165                 ret = snprintf(sock_path, LTTNG_PATH_MAX,
 166                                 DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK);
 167                 if (ret < 0) {
 168                         goto error;
 169                 }
 170         } else {
 171                 char *home_path = utils_get_home_dir();
 172
 173                 if (!home_path) {
 174                         ERR("Can't get HOME directory for socket creation");
 175                         goto error;
 176                 }
 177
 178                 ret = snprintf(sock_path, LTTNG_PATH_MAX,
 179                                 DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK,
 180                                 home_path);
 181                 if (ret < 0) {
 182                         goto error;
 183                 }
 184         }
 185
 186         return sock_path;
 187 error:
 188         free(sock_path);
 189         return NULL;
 190 }
 191
 192 static
 193 void notification_channel_socket_destroy(int fd)
 194 {
 195         int ret;
 196         char *sock_path = get_notification_channel_sock_path();
 197
 198         DBG("[notification-thread] Destroying notification channel socket");
 199
 200         if (sock_path) {
 201                 ret = unlink(sock_path);
 202                 free(sock_path);
 203                 if (ret < 0) {
 204                         PERROR("unlink notification channel socket");
 205                 }
 206         }
 207
 208         ret = close(fd);
 209         if (ret) {
 210                 PERROR("close notification channel socket");
 211         }
 212 }
 213
 214 static
 215 int notification_channel_socket_create(void)
 216 {
 217         int fd = -1, ret;
 218         char *sock_path = get_notification_channel_sock_path();
 219
 220         DBG("[notification-thread] Creating notification channel UNIX socket at %s",
 221                         sock_path);
 222
 223         ret = lttcomm_create_unix_sock(sock_path);
 224         if (ret < 0) {
 225                 ERR("[notification-thread] Failed to create notification socket");
 226                 goto error;
 227         }
 228         fd = ret;
 229
 230         ret = chmod(sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 231         if (ret < 0) {
 232                 ERR("Set file permissions failed: %s", sock_path);
 233                 PERROR("chmod notification channel socket");
 234                 goto error;
 235         }
 236
 237         if (getuid() == 0) {
 238                 ret = chown(sock_path, 0,
 239                                 utils_get_group_id(config.tracing_group_name.value));
 240                 if (ret) {
 241                         ERR("Failed to set the notification channel socket's group");
 242                         ret = -1;
 243                         goto error;
 244                 }
 245         }
 246
 247         DBG("[notification-thread] Notification channel UNIX socket created (fd = %i)",
 248                         fd);
 249         free(sock_path);
 250         return fd;
 251 error:
 252         if (fd >= 0 && close(fd) < 0) {
 253                 PERROR("close notification channel socket");
 254         }
 255         free(sock_path);
 256         return ret;
 257 }
 258
 259 static
 260 int init_poll_set(struct lttng_poll_event *poll_set,
 261                 struct notification_thread_handle *handle,
 262                 int notification_channel_socket)
 263 {
 264         int ret;
 265
 266         /*
 267          * Create pollset with size 5:
 268          *      - notification channel socket (listen for new connections),
 269          *      - command queue event fd (internal sessiond commands),
 270          *      - consumerd (32-bit user space) channel monitor pipe,
 271          *      - consumerd (64-bit user space) channel monitor pipe,
 272          *      - consumerd (kernel) channel monitor pipe.
 273          */
 274         ret = lttng_poll_create(poll_set, 5, LTTNG_CLOEXEC);
 275         if (ret < 0) {
 276                 goto end;
 277         }
 278
 279         ret = lttng_poll_add(poll_set, notification_channel_socket,
 280                         LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
 281         if (ret < 0) {
 282                 ERR("[notification-thread] Failed to add notification channel socket to pollset");
 283                 goto error;
 284         }
 285         ret = lttng_poll_add(poll_set, lttng_pipe_get_readfd(handle->cmd_queue.event_pipe),
 286                         LPOLLIN | LPOLLERR);
 287         if (ret < 0) {
 288                 ERR("[notification-thread] Failed to add notification command queue event fd to pollset");
 289                 goto error;
 290         }
 291         ret = lttng_poll_add(poll_set,
 292                         handle->channel_monitoring_pipes.ust32_consumer,
 293                         LPOLLIN | LPOLLERR);
 294         if (ret < 0) {
 295                 ERR("[notification-thread] Failed to add ust-32 channel monitoring pipe fd to pollset");
 296                 goto error;
 297         }
 298         ret = lttng_poll_add(poll_set,
 299                         handle->channel_monitoring_pipes.ust64_consumer,
 300                         LPOLLIN | LPOLLERR);
 301         if (ret < 0) {
 302                 ERR("[notification-thread] Failed to add ust-64 channel monitoring pipe fd to pollset");
 303                 goto error;
 304         }
 305         if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
 306                 goto end;
 307         }
 308         ret = lttng_poll_add(poll_set,
 309                         handle->channel_monitoring_pipes.kernel_consumer,
 310                         LPOLLIN | LPOLLERR);
 311         if (ret < 0) {
 312                 ERR("[notification-thread] Failed to add kernel channel monitoring pipe fd to pollset");
 313                 goto error;
 314         }
 315 end:
 316         return ret;
 317 error:
 318         lttng_poll_clean(poll_set);
 319         return ret;
 320 }
 321
 322 static
 323 void fini_thread_state(struct notification_thread_state *state)
 324 {
 325         int ret;
 326
 327         if (state->client_socket_ht) {
 328                 ret = handle_notification_thread_client_disconnect_all(state);
 329                 assert(!ret);
 330                 ret = cds_lfht_destroy(state->client_socket_ht, NULL);
 331                 assert(!ret);
 332         }
 333         if (state->triggers_ht) {
 334                 ret = handle_notification_thread_trigger_unregister_all(state);
 335                 assert(!ret);
 336                 ret = cds_lfht_destroy(state->triggers_ht, NULL);
 337                 assert(!ret);
 338         }
 339         if (state->channel_triggers_ht) {
 340                 ret = cds_lfht_destroy(state->channel_triggers_ht, NULL);
 341                 assert(!ret);
 342         }
 343         if (state->channel_state_ht) {
 344                 ret = cds_lfht_destroy(state->channel_state_ht, NULL);
 345                 assert(!ret);
 346         }
 347         if (state->notification_trigger_clients_ht) {
 348                 ret = cds_lfht_destroy(state->notification_trigger_clients_ht,
 349                                 NULL);
 350                 assert(!ret);
 351         }
 352         if (state->channels_ht) {
 353                 ret = cds_lfht_destroy(state->channels_ht, NULL);
 354                 assert(!ret);
 355         }
 356         if (state->sessions_ht) {
 357                 ret = cds_lfht_destroy(state->sessions_ht, NULL);
 358                 assert(!ret);
 359         }
 360         if (state->notification_channel_socket >= 0) {
 361                 notification_channel_socket_destroy(
 362                                 state->notification_channel_socket);
 363         }
 364         lttng_poll_clean(&state->events);
 365 }
 366
 367 static
 368 int init_thread_state(struct notification_thread_handle *handle,
 369                 struct notification_thread_state *state)
 370 {
 371         int ret;
 372
 373         memset(state, 0, sizeof(*state));
 374         state->notification_channel_socket = -1;
 375         lttng_poll_init(&state->events);
 376
 377         ret = notification_channel_socket_create();
 378         if (ret < 0) {
 379                 goto end;
 380         }
 381         state->notification_channel_socket = ret;
 382
 383         ret = init_poll_set(&state->events, handle,
 384                         state->notification_channel_socket);
 385         if (ret) {
 386                 goto end;
 387         }
 388
 389         DBG("[notification-thread] Listening on notification channel socket");
 390         ret = lttcomm_listen_unix_sock(state->notification_channel_socket);
 391         if (ret < 0) {
 392                 ERR("[notification-thread] Listen failed on notification channel socket");
 393                 goto error;
 394         }
 395
 396         state->client_socket_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
 397                         CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
 398         if (!state->client_socket_ht) {
 399                 goto error;
 400         }
 401
 402         state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
 403                         CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
 404         if (!state->channel_triggers_ht) {
 405                 goto error;
 406         }
 407
 408         state->channel_state_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
 409                         CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
 410         if (!state->channel_state_ht) {
 411                 goto error;
 412         }
 413
 414         state->notification_trigger_clients_ht = cds_lfht_new(DEFAULT_HT_SIZE,
 415                         1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
 416         if (!state->notification_trigger_clients_ht) {
 417                 goto error;
 418         }
 419
 420         state->channels_ht = cds_lfht_new(DEFAULT_HT_SIZE,
 421                         1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
 422         if (!state->channels_ht) {
 423                 goto error;
 424         }
 425         state->sessions_ht = cds_lfht_new(DEFAULT_HT_SIZE,
 426                         1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
 427         if (!state->sessions_ht) {
 428                 goto error;
 429         }
 430         state->triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE,
 431                         1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
 432         if (!state->triggers_ht) {
 433                 goto error;
 434         }
 435 end:
 436         return 0;
 437 error:
 438         fini_thread_state(state);
 439         return -1;
 440 }
 441
 442 static
 443 int handle_channel_monitoring_pipe(int fd, uint32_t revents,
 444                 struct notification_thread_handle *handle,
 445                 struct notification_thread_state *state)
 446 {
 447         int ret = 0;
 448         enum lttng_domain_type domain;
 449
 450         if (fd == handle->channel_monitoring_pipes.ust32_consumer ||
 451                         fd == handle->channel_monitoring_pipes.ust64_consumer) {
 452                 domain = LTTNG_DOMAIN_UST;
 453         } else if (fd == handle->channel_monitoring_pipes.kernel_consumer) {
 454                 domain = LTTNG_DOMAIN_KERNEL;
 455         } else {
 456                 abort();
 457         }
 458
 459         if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 460                 ret = lttng_poll_del(&state->events, fd);
 461                 if (ret) {
 462                         ERR("[notification-thread] Failed to remove consumer monitoring pipe from poll set");
 463                 }
 464                 goto end;
 465         }
 466
 467         ret = handle_notification_thread_channel_sample(
 468                         state, fd, domain);
 469         if (ret) {
 470                 ERR("[notification-thread] Consumer sample handling error occurred");
 471                 ret = -1;
 472                 goto end;
 473         }
 474 end:
 475         return ret;
 476 }
 477
 478 /*
 479  * This thread services notification channel clients and commands received
 480  * from various lttng-sessiond components over a command queue.
 481  */
 482 void *thread_notification(void *data)
 483 {
 484         int ret;
 485         struct notification_thread_handle *handle = data;
 486         struct notification_thread_state state;
 487
 488         DBG("[notification-thread] Started notification thread");
 489
 490         if (!handle) {
 491                 ERR("[notification-thread] Invalid thread context provided");
 492                 goto end;
 493         }
 494
 495         rcu_register_thread();
 496         rcu_thread_online();
 497
 498         health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
 499         health_code_update();
 500
 501         ret = init_thread_state(handle, &state);
 502         if (ret) {
 503                 goto end;
 504         }
 505
 506         /* Ready to handle client connections. */
 507         sessiond_notify_ready();
 508
 509         while (true) {
 510                 int fd_count, i;
 511
 512                 health_poll_entry();
 513                 DBG("[notification-thread] Entering poll wait");
 514                 ret = lttng_poll_wait(&state.events, -1);
 515                 DBG("[notification-thread] Poll wait returned (%i)", ret);
 516                 health_poll_exit();
 517                 if (ret < 0) {
 518                         /*
 519                          * Restart interrupted system call.
 520                          */
 521                         if (errno == EINTR) {
 522                                 continue;
 523                         }
 524                         ERR("[notification-thread] Error encountered during lttng_poll_wait (%i)", ret);
 525                         goto error;
 526                 }
 527
 528                 fd_count = ret;
 529                 for (i = 0; i < fd_count; i++) {
 530                         int fd = LTTNG_POLL_GETFD(&state.events, i);
 531                         uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);
 532
 533                         if (!revents) {
 534                                 continue;
 535                         }
 536                         DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents);
 537
 538                         if (fd == state.notification_channel_socket) {
 539                                 if (revents & LPOLLIN) {
 540                                         ret = handle_notification_thread_client_connect(
 541                                                         &state);
 542                                         if (ret < 0) {
 543                                                 goto error;
 544                                         }
 545                                 } else if (revents &
 546                                                 (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 547                                         ERR("[notification-thread] Notification socket poll error");
 548                                         goto error;
 549                                 } else {
 550                                         ERR("[notification-thread] Unexpected poll events %u for notification socket %i", revents, fd);
 551                                         goto error;
 552                                 }
 553                         } else if (fd == lttng_pipe_get_readfd(handle->cmd_queue.event_pipe)) {
 554                                 ret = handle_notification_thread_command(handle,
 555                                                 &state);
 556                                 if (ret < 0) {
 557                                         DBG("[notification-thread] Error encountered while servicing command queue");
 558                                         goto error;
 559                                 } else if (ret > 0) {
 560                                         goto exit;
 561                                 }
 562                         } else if (fd == handle->channel_monitoring_pipes.ust32_consumer ||
 563                                         fd == handle->channel_monitoring_pipes.ust64_consumer ||
 564                                         fd == handle->channel_monitoring_pipes.kernel_consumer) {
 565                                 ret = handle_channel_monitoring_pipe(fd,
 566                                                 revents, handle, &state);
 567                                 if (ret) {
 568                                         goto error;
 569                                 }
 570                         } else {
 571                                 /* Activity on a client's socket. */
 572                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 573                                         /*
 574                                          * It doesn't matter if a command was
 575                                          * pending on the client socket at this
 576                                          * point since it now has no way to
 577                                          * receive the notifications to which
 578                                          * it was subscribing or unsubscribing.
 579                                          */
 580                                         ret = handle_notification_thread_client_disconnect(
 581                                                         fd, &state);
 582                                         if (ret) {
 583                                                 goto error;
 584                                         }
 585                                 } else {
 586                                         if (revents & LPOLLIN) {
 587                                                 ret = handle_notification_thread_client_in(
 588                                                         &state, fd);
 589                                                 if (ret) {
 590                                                         goto error;
 591                                                 }
 592                                         }
 593
 594                                         if (revents & LPOLLOUT) {
 595                                                 ret = handle_notification_thread_client_out(
 596                                                         &state, fd);
 597                                                 if (ret) {
 598                                                         goto error;
 599                                                 }
 600                                         }
 601                                 }
 602                         }
 603                 }
 604         }
 605 exit:
 606 error:
 607         fini_thread_state(&state);
 608         health_unregister(health_sessiond);
 609         rcu_thread_offline();
 610         rcu_unregister_thread();
 611 end:
 612         return NULL;
 613 }