src/bin/lttng-relayd/main.c

   1 /*
   2  * Copyright (C) 2012 Julien Desfossez <jdesfossez@efficios.com>
   3  * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
   4  * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  *
   7  * SPDX-License-Identifier: GPL-2.0-only
   8  *
   9  */
  10
  11 #define _LGPL_SOURCE
  12 #include <getopt.h>
  13 #include <grp.h>
  14 #include <limits.h>
  15 #include <pthread.h>
  16 #include <signal.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <sys/mman.h>
  21 #include <sys/mount.h>
  22 #include <sys/resource.h>
  23 #include <sys/socket.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <sys/wait.h>
  27 #include <sys/resource.h>
  28 #include <inttypes.h>
  29 #include <urcu/futex.h>
  30 #include <urcu/uatomic.h>
  31 #include <urcu/rculist.h>
  32 #include <unistd.h>
  33 #include <fcntl.h>
  34 #include <strings.h>
  35 #include <ctype.h>
  36
  37 #include <lttng/lttng.h>
  38 #include <common/common.h>
  39 #include <common/compat/poll.h>
  40 #include <common/compat/socket.h>
  41 #include <common/compat/endian.h>
  42 #include <common/compat/getenv.h>
  43 #include <common/defaults.h>
  44 #include <common/daemonize.h>
  45 #include <common/futex.h>
  46 #include <common/sessiond-comm/sessiond-comm.h>
  47 #include <common/sessiond-comm/inet.h>
  48 #include <common/sessiond-comm/relayd.h>
  49 #include <common/uri.h>
  50 #include <common/utils.h>
  51 #include <common/align.h>
  52 #include <common/config/session-config.h>
  53 #include <common/dynamic-buffer.h>
  54 #include <common/buffer-view.h>
  55 #include <common/string-utils/format.h>
  56 #include <common/fd-tracker/fd-tracker.h>
  57 #include <common/fd-tracker/utils.h>
  58
  59 #include "backward-compatibility-group-by.h"
  60 #include "cmd.h"
  61 #include "connection.h"
  62 #include "ctf-trace.h"
  63 #include "health-relayd.h"
  64 #include "index.h"
  65 #include "live.h"
  66 #include "lttng-relayd.h"
  67 #include "session.h"
  68 #include "sessiond-trace-chunks.h"
  69 #include "stream.h"
  70 #include "tcp_keep_alive.h"
  71 #include "testpoint.h"
  72 #include "tracefile-array.h"
  73 #include "utils.h"
  74 #include "version.h"
  75 #include "viewer-stream.h"
  76
  77 static const char *help_msg =
  78 #ifdef LTTNG_EMBED_HELP
  79 #include <lttng-relayd.8.h>
  80 #else
  81 NULL
  82 #endif
  83 ;
  84
  85 enum relay_connection_status {
  86         RELAY_CONNECTION_STATUS_OK,
  87         /* An error occurred while processing an event on the connection. */
  88         RELAY_CONNECTION_STATUS_ERROR,
  89         /* Connection closed/shutdown cleanly. */
  90         RELAY_CONNECTION_STATUS_CLOSED,
  91 };
  92
  93 /* command line options */
  94 char *opt_output_path, *opt_working_directory;
  95 static int opt_daemon, opt_background, opt_print_version, opt_allow_clear = 1;
  96 enum relay_group_output_by opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_UNKNOWN;
  97
  98 /*
  99  * We need to wait for listener and live listener threads, as well as
 100  * health check thread, before being ready to signal readiness.
 101  */
 102 #define NR_LTTNG_RELAY_READY    3
 103 static int lttng_relay_ready = NR_LTTNG_RELAY_READY;
 104
 105 /* Size of receive buffer. */
 106 #define RECV_DATA_BUFFER_SIZE           65536
 107
 108 static int recv_child_signal;   /* Set to 1 when a SIGUSR1 signal is received. */
 109 static pid_t child_ppid;        /* Internal parent PID use with daemonize. */
 110
 111 static struct lttng_uri *control_uri;
 112 static struct lttng_uri *data_uri;
 113 static struct lttng_uri *live_uri;
 114
 115 const char *progname;
 116
 117 const char *tracing_group_name = DEFAULT_TRACING_GROUP;
 118 static int tracing_group_name_override;
 119
 120 const char * const config_section_name = "relayd";
 121
 122 /*
 123  * Quit pipe for all threads. This permits a single cancellation point
 124  * for all threads when receiving an event on the pipe.
 125  */
 126 int thread_quit_pipe[2] = { -1, -1 };
 127
 128 /*
 129  * This pipe is used to inform the worker thread that a command is queued and
 130  * ready to be processed.
 131  */
 132 static int relay_conn_pipe[2] = { -1, -1 };
 133
 134 /* Shared between threads */
 135 static int dispatch_thread_exit;
 136
 137 static pthread_t listener_thread;
 138 static pthread_t dispatcher_thread;
 139 static pthread_t worker_thread;
 140 static pthread_t health_thread;
 141
 142 /*
 143  * last_relay_stream_id_lock protects last_relay_stream_id increment
 144  * atomicity on 32-bit architectures.
 145  */
 146 static pthread_mutex_t last_relay_stream_id_lock = PTHREAD_MUTEX_INITIALIZER;
 147 static uint64_t last_relay_stream_id;
 148
 149 /*
 150  * Relay command queue.
 151  *
 152  * The relay_thread_listener and relay_thread_dispatcher communicate with this
 153  * queue.
 154  */
 155 static struct relay_conn_queue relay_conn_queue;
 156
 157 /* Cap of file desriptors to be in simultaneous use by the relay daemon. */
 158 static unsigned int lttng_opt_fd_pool_size = -1;
 159
 160 /* Global relay stream hash table. */
 161 struct lttng_ht *relay_streams_ht;
 162
 163 /* Global relay viewer stream hash table. */
 164 struct lttng_ht *viewer_streams_ht;
 165
 166 /* Global relay sessions hash table. */
 167 struct lttng_ht *sessions_ht;
 168
 169 /* Relayd health monitoring */
 170 struct health_app *health_relayd;
 171
 172 struct sessiond_trace_chunk_registry *sessiond_trace_chunk_registry;
 173
 174 /* Global fd tracker. */
 175 struct fd_tracker *the_fd_tracker;
 176
 177 static struct option long_options[] = {
 178         { "control-port", 1, 0, 'C', },
 179         { "data-port", 1, 0, 'D', },
 180         { "live-port", 1, 0, 'L', },
 181         { "daemonize", 0, 0, 'd', },
 182         { "background", 0, 0, 'b', },
 183         { "group", 1, 0, 'g', },
 184         { "fd-pool-size", 1, 0, '\0', },
 185         { "help", 0, 0, 'h', },
 186         { "output", 1, 0, 'o', },
 187         { "verbose", 0, 0, 'v', },
 188         { "config", 1, 0, 'f' },
 189         { "version", 0, 0, 'V' },
 190         { "working-directory", 1, 0, 'w', },
 191         { "group-output-by-session", 0, 0, 's', },
 192         { "group-output-by-host", 0, 0, 'p', },
 193         { "disallow-clear", 0, 0, 'x' },
 194         { NULL, 0, 0, 0, },
 195 };
 196
 197 static const char *config_ignore_options[] = { "help", "config", "version" };
 198
 199 static void print_version(void) {
 200         fprintf(stdout, "%s\n", VERSION);
 201 }
 202
 203 static void relayd_config_log(void)
 204 {
 205         DBG("LTTng-relayd " VERSION " - " VERSION_NAME "%s%s",
 206                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION,
 207                         EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " EXTRA_VERSION_NAME);
 208         if (EXTRA_VERSION_DESCRIPTION[0] != '\0') {
 209                 DBG("LTTng-relayd extra version description:\n\t" EXTRA_VERSION_DESCRIPTION "\n");
 210         }
 211         if (EXTRA_VERSION_PATCHES[0] != '\0') {
 212                 DBG("LTTng-relayd extra patches:\n\t" EXTRA_VERSION_PATCHES "\n");
 213         }
 214 }
 215
 216 /*
 217  * Take an option from the getopt output and set it in the right variable to be
 218  * used later.
 219  *
 220  * Return 0 on success else a negative value.
 221  */
 222 static int set_option(int opt, const char *arg, const char *optname)
 223 {
 224         int ret;
 225
 226         switch (opt) {
 227         case 0:
 228                 if (!strcmp(optname, "fd-pool-size")) {
 229                         unsigned long v;
 230
 231                         errno = 0;
 232                         v = strtoul(arg, NULL, 0);
 233                         if (errno != 0 || !isdigit((unsigned char) arg[0])) {
 234                                 ERR("Wrong value in --fd-pool-size parameter: %s", arg);
 235                                 ret = -1;
 236                                 goto end;
 237                         }
 238                         if (v >= UINT_MAX) {
 239                                 ERR("File descriptor cap overflow in --fd-pool-size parameter: %s", arg);
 240                                 ret = -1;
 241                                 goto end;
 242                         }
 243                         lttng_opt_fd_pool_size = (unsigned int) v;
 244                 } else {
 245                         fprintf(stderr, "unknown option %s", optname);
 246                         if (arg) {
 247                                 fprintf(stderr, " with arg %s\n", arg);
 248                         }
 249                 }
 250                 break;
 251         case 'C':
 252                 if (lttng_is_setuid_setgid()) {
 253                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 254                                 "-C, --control-port");
 255                 } else {
 256                         ret = uri_parse(arg, &control_uri);
 257                         if (ret < 0) {
 258                                 ERR("Invalid control URI specified");
 259                                 goto end;
 260                         }
 261                         if (control_uri->port == 0) {
 262                                 control_uri->port = DEFAULT_NETWORK_CONTROL_PORT;
 263                         }
 264                 }
 265                 break;
 266         case 'D':
 267                 if (lttng_is_setuid_setgid()) {
 268                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 269                                 "-D, -data-port");
 270                 } else {
 271                         ret = uri_parse(arg, &data_uri);
 272                         if (ret < 0) {
 273                                 ERR("Invalid data URI specified");
 274                                 goto end;
 275                         }
 276                         if (data_uri->port == 0) {
 277                                 data_uri->port = DEFAULT_NETWORK_DATA_PORT;
 278                         }
 279                 }
 280                 break;
 281         case 'L':
 282                 if (lttng_is_setuid_setgid()) {
 283                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 284                                 "-L, -live-port");
 285                 } else {
 286                         ret = uri_parse(arg, &live_uri);
 287                         if (ret < 0) {
 288                                 ERR("Invalid live URI specified");
 289                                 goto end;
 290                         }
 291                         if (live_uri->port == 0) {
 292                                 live_uri->port = DEFAULT_NETWORK_VIEWER_PORT;
 293                         }
 294                 }
 295                 break;
 296         case 'd':
 297                 opt_daemon = 1;
 298                 break;
 299         case 'b':
 300                 opt_background = 1;
 301                 break;
 302         case 'g':
 303                 if (lttng_is_setuid_setgid()) {
 304                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 305                                 "-g, --group");
 306                 } else {
 307                         tracing_group_name = strdup(arg);
 308                         if (tracing_group_name == NULL) {
 309                                 ret = -errno;
 310                                 PERROR("strdup");
 311                                 goto end;
 312                         }
 313                         tracing_group_name_override = 1;
 314                 }
 315                 break;
 316         case 'h':
 317                 ret = utils_show_help(8, "lttng-relayd", help_msg);
 318                 if (ret) {
 319                         ERR("Cannot show --help for `lttng-relayd`");
 320                         perror("exec");
 321                 }
 322                 exit(EXIT_FAILURE);
 323         case 'V':
 324                 opt_print_version = 1;
 325                 break;
 326         case 'o':
 327                 if (lttng_is_setuid_setgid()) {
 328                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 329                                 "-o, --output");
 330                 } else {
 331                         ret = asprintf(&opt_output_path, "%s", arg);
 332                         if (ret < 0) {
 333                                 ret = -errno;
 334                                 PERROR("asprintf opt_output_path");
 335                                 goto end;
 336                         }
 337                 }
 338                 break;
 339         case 'w':
 340                 if (lttng_is_setuid_setgid()) {
 341                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 342                                 "-w, --working-directory");
 343                 } else {
 344                         ret = asprintf(&opt_working_directory, "%s", arg);
 345                         if (ret < 0) {
 346                                 ret = -errno;
 347                                 PERROR("asprintf opt_working_directory");
 348                                 goto end;
 349                         }
 350                 }
 351                 break;
 352
 353         case 'v':
 354                 /* Verbose level can increase using multiple -v */
 355                 if (arg) {
 356                         lttng_opt_verbose = config_parse_value(arg);
 357                 } else {
 358                         /* Only 3 level of verbosity (-vvv). */
 359                         if (lttng_opt_verbose < 3) {
 360                                 lttng_opt_verbose += 1;
 361                         }
 362                 }
 363                 break;
 364         case 's':
 365                 if (opt_group_output_by != RELAYD_GROUP_OUTPUT_BY_UNKNOWN) {
 366                         ERR("Cannot set --group-output-by-session, another --group-output-by argument is present");
 367                         exit(EXIT_FAILURE);
 368                 }
 369                 opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_SESSION;
 370                 break;
 371         case 'p':
 372                 if (opt_group_output_by != RELAYD_GROUP_OUTPUT_BY_UNKNOWN) {
 373                         ERR("Cannot set --group-output-by-host, another --group-output-by argument is present");
 374                         exit(EXIT_FAILURE);
 375                 }
 376                 opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_HOST;
 377                 break;
 378         case 'x':
 379                 /* Disallow clear */
 380                 opt_allow_clear = 0;
 381                 break;
 382         default:
 383                 /* Unknown option or other error.
 384                  * Error is printed by getopt, just return */
 385                 ret = -1;
 386                 goto end;
 387         }
 388
 389         /* All good. */
 390         ret = 0;
 391
 392 end:
 393         return ret;
 394 }
 395
 396 /*
 397  * config_entry_handler_cb used to handle options read from a config file.
 398  * See config_entry_handler_cb comment in common/config/session-config.h for the
 399  * return value conventions.
 400  */
 401 static int config_entry_handler(const struct config_entry *entry, void *unused)
 402 {
 403         int ret = 0, i;
 404
 405         if (!entry || !entry->name || !entry->value) {
 406                 ret = -EINVAL;
 407                 goto end;
 408         }
 409
 410         /* Check if the option is to be ignored */
 411         for (i = 0; i < sizeof(config_ignore_options) / sizeof(char *); i++) {
 412                 if (!strcmp(entry->name, config_ignore_options[i])) {
 413                         goto end;
 414                 }
 415         }
 416
 417         for (i = 0; i < (sizeof(long_options) / sizeof(struct option)) - 1; i++) {
 418                 /* Ignore if entry name is not fully matched. */
 419                 if (strcmp(entry->name, long_options[i].name)) {
 420                         continue;
 421                 }
 422
 423                 /*
 424                  * If the option takes no argument on the command line,
 425                  * we have to check if the value is "true". We support
 426                  * non-zero numeric values, true, on and yes.
 427                  */
 428                 if (!long_options[i].has_arg) {
 429                         ret = config_parse_value(entry->value);
 430                         if (ret <= 0) {
 431                                 if (ret) {
 432                                         WARN("Invalid configuration value \"%s\" for option %s",
 433                                                         entry->value, entry->name);
 434                                 }
 435                                 /* False, skip boolean config option. */
 436                                 goto end;
 437                         }
 438                 }
 439
 440                 ret = set_option(long_options[i].val, entry->value, entry->name);
 441                 goto end;
 442         }
 443
 444         WARN("Unrecognized option \"%s\" in daemon configuration file.",
 445                         entry->name);
 446
 447 end:
 448         return ret;
 449 }
 450
 451 static int parse_env_options(void)
 452 {
 453         int ret = 0;
 454         char *value = NULL;
 455
 456         value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_WORKING_DIRECTORY_ENV);
 457         if (value) {
 458                 opt_working_directory = strdup(value);
 459                 if (!opt_working_directory) {
 460                         ERR("Failed to allocate working directory string (\"%s\")",
 461                                         value);
 462                         ret = -1;
 463                 }
 464         }
 465         return ret;
 466 }
 467
 468 static int set_fd_pool_size(void)
 469 {
 470         int ret = 0;
 471         struct rlimit rlimit;
 472
 473         ret = getrlimit(RLIMIT_NOFILE, &rlimit);
 474         if (ret) {
 475                 PERROR("Failed to get file descriptor limit");
 476                 ret = -1;
 477                 goto end;
 478         }
 479
 480         DBG("File descriptor count limits are %" PRIu64 " (soft) and %" PRIu64 " (hard)",
 481                         (uint64_t) rlimit.rlim_cur,
 482                         (uint64_t) rlimit.rlim_max);
 483         if (lttng_opt_fd_pool_size == -1) {
 484                 /* Use default value (soft limit - reserve). */
 485                 if (rlimit.rlim_cur < DEFAULT_RELAYD_MIN_FD_POOL_SIZE) {
 486                         ERR("The process' file number limit is too low (%" PRIu64 "). The process' file number limit must be set to at least %i.",
 487                                         (uint64_t) rlimit.rlim_cur, DEFAULT_RELAYD_MIN_FD_POOL_SIZE);
 488                         ret = -1;
 489                         goto end;
 490                 }
 491                 lttng_opt_fd_pool_size = rlimit.rlim_cur -
 492                                 DEFAULT_RELAYD_FD_POOL_SIZE_RESERVE;
 493                 goto end;
 494         }
 495
 496         if (lttng_opt_fd_pool_size < DEFAULT_RELAYD_MIN_FD_POOL_SIZE) {
 497                 ERR("File descriptor pool size must be set to at least %d",
 498                                 DEFAULT_RELAYD_MIN_FD_POOL_SIZE);
 499                 ret = -1;
 500                 goto end;
 501         }
 502
 503         if (lttng_opt_fd_pool_size > rlimit.rlim_cur) {
 504                 ERR("File descriptor pool size argument (%u) exceeds the process' soft limit (%" PRIu64 ").",
 505                                 lttng_opt_fd_pool_size, (uint64_t) rlimit.rlim_cur);
 506                 ret = -1;
 507                 goto end;
 508         }
 509
 510         DBG("File descriptor pool size argument (%u) adjusted to %u to accommodates transient fd uses",
 511                         lttng_opt_fd_pool_size,
 512                         lttng_opt_fd_pool_size - DEFAULT_RELAYD_FD_POOL_SIZE_RESERVE);
 513         lttng_opt_fd_pool_size -= DEFAULT_RELAYD_FD_POOL_SIZE_RESERVE;
 514 end:
 515         return ret;
 516 }
 517
 518 static int set_options(int argc, char **argv)
 519 {
 520         int c, ret = 0, option_index = 0, retval = 0;
 521         int orig_optopt = optopt, orig_optind = optind;
 522         char *default_address, *optstring;
 523         const char *config_path = NULL;
 524
 525         optstring = utils_generate_optstring(long_options,
 526                         sizeof(long_options) / sizeof(struct option));
 527         if (!optstring) {
 528                 retval = -ENOMEM;
 529                 goto exit;
 530         }
 531
 532         /* Check for the --config option */
 533
 534         while ((c = getopt_long(argc, argv, optstring, long_options,
 535                                         &option_index)) != -1) {
 536                 if (c == '?') {
 537                         retval = -EINVAL;
 538                         goto exit;
 539                 } else if (c != 'f') {
 540                         continue;
 541                 }
 542
 543                 if (lttng_is_setuid_setgid()) {
 544                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 545                                 "-f, --config");
 546                 } else {
 547                         config_path = utils_expand_path(optarg);
 548                         if (!config_path) {
 549                                 ERR("Failed to resolve path: %s", optarg);
 550                         }
 551                 }
 552         }
 553
 554         ret = config_get_section_entries(config_path, config_section_name,
 555                         config_entry_handler, NULL);
 556         if (ret) {
 557                 if (ret > 0) {
 558                         ERR("Invalid configuration option at line %i", ret);
 559                 }
 560                 retval = -1;
 561                 goto exit;
 562         }
 563
 564         /* Reset getopt's global state */
 565         optopt = orig_optopt;
 566         optind = orig_optind;
 567         while (1) {
 568                 c = getopt_long(argc, argv, optstring, long_options, &option_index);
 569                 if (c == -1) {
 570                         break;
 571                 }
 572
 573                 ret = set_option(c, optarg, long_options[option_index].name);
 574                 if (ret < 0) {
 575                         retval = -1;
 576                         goto exit;
 577                 }
 578         }
 579
 580         /* assign default values */
 581         if (control_uri == NULL) {
 582                 ret = asprintf(&default_address,
 583                         "tcp://" DEFAULT_NETWORK_CONTROL_BIND_ADDRESS ":%d",
 584                         DEFAULT_NETWORK_CONTROL_PORT);
 585                 if (ret < 0) {
 586                         PERROR("asprintf default data address");
 587                         retval = -1;
 588                         goto exit;
 589                 }
 590
 591                 ret = uri_parse(default_address, &control_uri);
 592                 free(default_address);
 593                 if (ret < 0) {
 594                         ERR("Invalid control URI specified");
 595                         retval = -1;
 596                         goto exit;
 597                 }
 598         }
 599         if (data_uri == NULL) {
 600                 ret = asprintf(&default_address,
 601                         "tcp://" DEFAULT_NETWORK_DATA_BIND_ADDRESS ":%d",
 602                         DEFAULT_NETWORK_DATA_PORT);
 603                 if (ret < 0) {
 604                         PERROR("asprintf default data address");
 605                         retval = -1;
 606                         goto exit;
 607                 }
 608
 609                 ret = uri_parse(default_address, &data_uri);
 610                 free(default_address);
 611                 if (ret < 0) {
 612                         ERR("Invalid data URI specified");
 613                         retval = -1;
 614                         goto exit;
 615                 }
 616         }
 617         if (live_uri == NULL) {
 618                 ret = asprintf(&default_address,
 619                         "tcp://" DEFAULT_NETWORK_VIEWER_BIND_ADDRESS ":%d",
 620                         DEFAULT_NETWORK_VIEWER_PORT);
 621                 if (ret < 0) {
 622                         PERROR("asprintf default viewer control address");
 623                         retval = -1;
 624                         goto exit;
 625                 }
 626
 627                 ret = uri_parse(default_address, &live_uri);
 628                 free(default_address);
 629                 if (ret < 0) {
 630                         ERR("Invalid viewer control URI specified");
 631                         retval = -1;
 632                         goto exit;
 633                 }
 634         }
 635         ret = set_fd_pool_size();
 636         if (ret) {
 637                 retval = -1;
 638                 goto exit;
 639         }
 640
 641         if (opt_group_output_by == RELAYD_GROUP_OUTPUT_BY_UNKNOWN) {
 642                 opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_HOST;
 643         }
 644         if (opt_allow_clear) {
 645                 /* Check if env variable exists. */
 646                 const char *value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_DISALLOW_CLEAR_ENV);
 647                 if (value) {
 648                         ret = config_parse_value(value);
 649                         if (ret < 0) {
 650                                 ERR("Invalid value for %s specified", DEFAULT_LTTNG_RELAYD_DISALLOW_CLEAR_ENV);
 651                                 retval = -1;
 652                                 goto exit;
 653                         }
 654                         opt_allow_clear = !ret;
 655                 }
 656         }
 657
 658 exit:
 659         free(optstring);
 660         return retval;
 661 }
 662
 663 static void print_global_objects(void)
 664 {
 665         print_viewer_streams();
 666         print_relay_streams();
 667         print_sessions();
 668 }
 669
 670 static int noop_close(void *data, int *fds)
 671 {
 672         return 0;
 673 }
 674
 675 static void untrack_stdio(void)
 676 {
 677         int fds[] = { fileno(stdout), fileno(stderr) };
 678
 679         /*
 680          * noop_close is used since we don't really want to close
 681          * the stdio output fds; we merely want to stop tracking them.
 682          */
 683         (void) fd_tracker_close_unsuspendable_fd(the_fd_tracker,
 684                         fds, 2, noop_close, NULL);
 685 }
 686
 687 /*
 688  * Cleanup the daemon
 689  */
 690 static void relayd_cleanup(void)
 691 {
 692         print_global_objects();
 693
 694         DBG("Cleaning up");
 695
 696         if (viewer_streams_ht)
 697                 lttng_ht_destroy(viewer_streams_ht);
 698         if (relay_streams_ht)
 699                 lttng_ht_destroy(relay_streams_ht);
 700         if (sessions_ht)
 701                 lttng_ht_destroy(sessions_ht);
 702
 703         free(opt_output_path);
 704         free(opt_working_directory);
 705
 706         if (health_relayd) {
 707                 health_app_destroy(health_relayd);
 708         }
 709         /* Close thread quit pipes */
 710         if (health_quit_pipe[0] != -1) {
 711                 (void) fd_tracker_util_pipe_close(
 712                                 the_fd_tracker, health_quit_pipe);
 713         }
 714         if (thread_quit_pipe[0] != -1) {
 715                 (void) fd_tracker_util_pipe_close(
 716                                 the_fd_tracker, thread_quit_pipe);
 717         }
 718         if (sessiond_trace_chunk_registry) {
 719                 sessiond_trace_chunk_registry_destroy(
 720                                 sessiond_trace_chunk_registry);
 721         }
 722         if (the_fd_tracker) {
 723                 untrack_stdio();
 724                 /*
 725                  * fd_tracker_destroy() will log the contents of the fd-tracker
 726                  * if a leak is detected.
 727                  */
 728                 fd_tracker_destroy(the_fd_tracker);
 729         }
 730
 731         uri_free(control_uri);
 732         uri_free(data_uri);
 733         /* Live URI is freed in the live thread. */
 734
 735         if (tracing_group_name_override) {
 736                 free((void *) tracing_group_name);
 737         }
 738 }
 739
 740 /*
 741  * Write to writable pipe used to notify a thread.
 742  */
 743 static int notify_thread_pipe(int wpipe)
 744 {
 745         ssize_t ret;
 746
 747         ret = lttng_write(wpipe, "!", 1);
 748         if (ret < 1) {
 749                 PERROR("write poll pipe");
 750                 goto end;
 751         }
 752         ret = 0;
 753 end:
 754         return ret;
 755 }
 756
 757 static int notify_health_quit_pipe(int *pipe)
 758 {
 759         ssize_t ret;
 760
 761         ret = lttng_write(pipe[1], "4", 1);
 762         if (ret < 1) {
 763                 PERROR("write relay health quit");
 764                 goto end;
 765         }
 766         ret = 0;
 767 end:
 768         return ret;
 769 }
 770
 771 /*
 772  * Stop all relayd and relayd-live threads.
 773  */
 774 int lttng_relay_stop_threads(void)
 775 {
 776         int retval = 0;
 777
 778         /* Stopping all threads */
 779         DBG("Terminating all threads");
 780         if (notify_thread_pipe(thread_quit_pipe[1])) {
 781                 ERR("write error on thread quit pipe");
 782                 retval = -1;
 783         }
 784
 785         if (notify_health_quit_pipe(health_quit_pipe)) {
 786                 ERR("write error on health quit pipe");
 787         }
 788
 789         /* Dispatch thread */
 790         CMM_STORE_SHARED(dispatch_thread_exit, 1);
 791         futex_nto1_wake(&relay_conn_queue.futex);
 792
 793         if (relayd_live_stop()) {
 794                 ERR("Error stopping live threads");
 795                 retval = -1;
 796         }
 797         return retval;
 798 }
 799
 800 /*
 801  * Signal handler for the daemon
 802  *
 803  * Simply stop all worker threads, leaving main() return gracefully after
 804  * joining all threads and calling cleanup().
 805  */
 806 static void sighandler(int sig)
 807 {
 808         switch (sig) {
 809         case SIGINT:
 810                 DBG("SIGINT caught");
 811                 if (lttng_relay_stop_threads()) {
 812                         ERR("Error stopping threads");
 813                 }
 814                 break;
 815         case SIGTERM:
 816                 DBG("SIGTERM caught");
 817                 if (lttng_relay_stop_threads()) {
 818                         ERR("Error stopping threads");
 819                 }
 820                 break;
 821         case SIGUSR1:
 822                 CMM_STORE_SHARED(recv_child_signal, 1);
 823                 break;
 824         default:
 825                 break;
 826         }
 827 }
 828
 829 /*
 830  * Setup signal handler for :
 831  *              SIGINT, SIGTERM, SIGPIPE
 832  */
 833 static int set_signal_handler(void)
 834 {
 835         int ret = 0;
 836         struct sigaction sa;
 837         sigset_t sigset;
 838
 839         if ((ret = sigemptyset(&sigset)) < 0) {
 840                 PERROR("sigemptyset");
 841                 return ret;
 842         }
 843
 844         sa.sa_mask = sigset;
 845         sa.sa_flags = 0;
 846
 847         sa.sa_handler = sighandler;
 848         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 849                 PERROR("sigaction");
 850                 return ret;
 851         }
 852
 853         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
 854                 PERROR("sigaction");
 855                 return ret;
 856         }
 857
 858         if ((ret = sigaction(SIGUSR1, &sa, NULL)) < 0) {
 859                 PERROR("sigaction");
 860                 return ret;
 861         }
 862
 863         sa.sa_handler = SIG_IGN;
 864         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 865                 PERROR("sigaction");
 866                 return ret;
 867         }
 868
 869         DBG("Signal handler set for SIGTERM, SIGUSR1, SIGPIPE and SIGINT");
 870
 871         return ret;
 872 }
 873
 874 void lttng_relay_notify_ready(void)
 875 {
 876         /* Notify the parent of the fork() process that we are ready. */
 877         if (opt_daemon || opt_background) {
 878                 if (uatomic_sub_return(&lttng_relay_ready, 1) == 0) {
 879                         kill(child_ppid, SIGUSR1);
 880                 }
 881         }
 882 }
 883
 884 /*
 885  * Init thread quit pipe.
 886  *
 887  * Return -1 on error or 0 if all pipes are created.
 888  */
 889 static int init_thread_quit_pipe(void)
 890 {
 891         return fd_tracker_util_pipe_open_cloexec(
 892                         the_fd_tracker, "Quit pipe", thread_quit_pipe);
 893 }
 894
 895 /*
 896  * Init health quit pipe.
 897  *
 898  * Return -1 on error or 0 if all pipes are created.
 899  */
 900 static int init_health_quit_pipe(void)
 901 {
 902         return fd_tracker_util_pipe_open_cloexec(the_fd_tracker,
 903                         "Health quit pipe", health_quit_pipe);
 904 }
 905
 906 /*
 907  * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
 908  */
 909 static int create_named_thread_poll_set(struct lttng_poll_event *events,
 910                 int size, const char *name)
 911 {
 912         int ret;
 913
 914         if (events == NULL || size == 0) {
 915                 ret = -1;
 916                 goto error;
 917         }
 918
 919         ret = fd_tracker_util_poll_create(the_fd_tracker,
 920                         name, events, 1, LTTNG_CLOEXEC);
 921         if (ret) {
 922                 PERROR("Failed to create \"%s\" poll file descriptor", name);
 923                 goto error;
 924         }
 925
 926         /* Add quit pipe */
 927         ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN | LPOLLERR);
 928         if (ret < 0) {
 929                 goto error;
 930         }
 931
 932         return 0;
 933
 934 error:
 935         return ret;
 936 }
 937
 938 /*
 939  * Check if the thread quit pipe was triggered.
 940  *
 941  * Return 1 if it was triggered else 0;
 942  */
 943 static int check_thread_quit_pipe(int fd, uint32_t events)
 944 {
 945         if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
 946                 return 1;
 947         }
 948
 949         return 0;
 950 }
 951
 952 static int create_sock(void *data, int *out_fd)
 953 {
 954         int ret;
 955         struct lttcomm_sock *sock = data;
 956
 957         ret = lttcomm_create_sock(sock);
 958         if (ret < 0) {
 959                 goto end;
 960         }
 961
 962         *out_fd = sock->fd;
 963 end:
 964         return ret;
 965 }
 966
 967 static int close_sock(void *data, int *in_fd)
 968 {
 969         struct lttcomm_sock *sock = data;
 970
 971         return sock->ops->close(sock);
 972 }
 973
 974 static int accept_sock(void *data, int *out_fd)
 975 {
 976         int ret = 0;
 977         /* Socks is an array of in_sock, out_sock. */
 978         struct lttcomm_sock **socks = data;
 979         struct lttcomm_sock *in_sock = socks[0];
 980
 981         socks[1] = in_sock->ops->accept(in_sock);
 982         if (!socks[1]) {
 983                 ret = -1;
 984                 goto end;
 985         }
 986         *out_fd = socks[1]->fd;
 987 end:
 988         return ret;
 989 }
 990
 991 /*
 992  * Create and init socket from uri.
 993  */
 994 static struct lttcomm_sock *relay_socket_create(struct lttng_uri *uri,
 995                 const char *name)
 996 {
 997         int ret, sock_fd;
 998         struct lttcomm_sock *sock = NULL;
 999         char uri_str[PATH_MAX];
1000         char *formated_name = NULL;
1001
1002         sock = lttcomm_alloc_sock_from_uri(uri);
1003         if (sock == NULL) {
1004                 ERR("Allocating socket");
1005                 goto error;
1006         }
1007
1008         /*
1009          * Don't fail to create the socket if the name can't be built as it is
1010          * only used for debugging purposes.
1011          */
1012         ret = uri_to_str_url(uri, uri_str, sizeof(uri_str));
1013         uri_str[sizeof(uri_str) - 1] = '\0';
1014         if (ret >= 0) {
1015                 ret = asprintf(&formated_name, "%s socket @ %s", name,
1016                                 uri_str);
1017                 if (ret < 0) {
1018                         formated_name = NULL;
1019                 }
1020         }
1021
1022         ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker, &sock_fd,
1023                         (const char **) (formated_name ? &formated_name : NULL),
1024                         1, create_sock, sock);
1025         if (ret) {
1026                 PERROR("Failed to open \"%s\" relay socket",
1027                                 formated_name ?: "Unknown");
1028                 goto error;
1029         }
1030         DBG("Listening on %s socket %d", name, sock->fd);
1031
1032         ret = sock->ops->bind(sock);
1033         if (ret < 0) {
1034                 PERROR("Failed to bind socket");
1035                 goto error;
1036         }
1037
1038         ret = sock->ops->listen(sock, -1);
1039         if (ret < 0) {
1040                 goto error;
1041
1042         }
1043
1044         free(formated_name);
1045         return sock;
1046
1047 error:
1048         if (sock) {
1049                 lttcomm_destroy_sock(sock);
1050         }
1051         free(formated_name);
1052         return NULL;
1053 }
1054
1055 static
1056 struct lttcomm_sock *accept_relayd_sock(struct lttcomm_sock *listening_sock,
1057                 const char *name)
1058 {
1059         int out_fd, ret;
1060         struct lttcomm_sock *socks[2] = { listening_sock, NULL };
1061         struct lttcomm_sock *new_sock = NULL;
1062
1063         ret = fd_tracker_open_unsuspendable_fd(
1064                         the_fd_tracker, &out_fd,
1065                         (const char **) &name,
1066                         1, accept_sock, &socks);
1067         if (ret) {
1068                 goto end;
1069         }
1070         new_sock = socks[1];
1071         DBG("%s accepted, socket %d", name, new_sock->fd);
1072 end:
1073         return new_sock;
1074 }
1075
1076 /*
1077  * This thread manages the listening for new connections on the network
1078  */
1079 static void *relay_thread_listener(void *data)
1080 {
1081         int i, ret, pollfd, err = -1;
1082         uint32_t revents, nb_fd;
1083         struct lttng_poll_event events;
1084         struct lttcomm_sock *control_sock, *data_sock;
1085
1086         DBG("[thread] Relay listener started");
1087
1088         rcu_register_thread();
1089         health_register(health_relayd, HEALTH_RELAYD_TYPE_LISTENER);
1090
1091         health_code_update();
1092
1093         control_sock = relay_socket_create(control_uri, "Control listener");
1094         if (!control_sock) {
1095                 goto error_sock_control;
1096         }
1097
1098         data_sock = relay_socket_create(data_uri, "Data listener");
1099         if (!data_sock) {
1100                 goto error_sock_relay;
1101         }
1102
1103         /*
1104          * Pass 3 as size here for the thread quit pipe, control and
1105          * data socket.
1106          */
1107         ret = create_named_thread_poll_set(&events, 3, "Listener thread epoll");
1108         if (ret < 0) {
1109                 goto error_create_poll;
1110         }
1111
1112         /* Add the control socket */
1113         ret = lttng_poll_add(&events, control_sock->fd, LPOLLIN | LPOLLRDHUP);
1114         if (ret < 0) {
1115                 goto error_poll_add;
1116         }
1117
1118         /* Add the data socket */
1119         ret = lttng_poll_add(&events, data_sock->fd, LPOLLIN | LPOLLRDHUP);
1120         if (ret < 0) {
1121                 goto error_poll_add;
1122         }
1123
1124         lttng_relay_notify_ready();
1125
1126         if (testpoint(relayd_thread_listener)) {
1127                 goto error_testpoint;
1128         }
1129
1130         while (1) {
1131                 health_code_update();
1132
1133                 DBG("Listener accepting connections");
1134
1135 restart:
1136                 health_poll_entry();
1137                 ret = lttng_poll_wait(&events, -1);
1138                 health_poll_exit();
1139                 if (ret < 0) {
1140                         /*
1141                          * Restart interrupted system call.
1142                          */
1143                         if (errno == EINTR) {
1144                                 goto restart;
1145                         }
1146                         goto error;
1147                 }
1148
1149                 nb_fd = ret;
1150
1151                 DBG("Relay new connection received");
1152                 for (i = 0; i < nb_fd; i++) {
1153                         health_code_update();
1154
1155                         /* Fetch once the poll data */
1156                         revents = LTTNG_POLL_GETEV(&events, i);
1157                         pollfd = LTTNG_POLL_GETFD(&events, i);
1158
1159                         /* Thread quit pipe has been closed. Killing thread. */
1160                         ret = check_thread_quit_pipe(pollfd, revents);
1161                         if (ret) {
1162                                 err = 0;
1163                                 goto exit;
1164                         }
1165
1166                         if (revents & LPOLLIN) {
1167                                 /*
1168                                  * A new connection is requested, therefore a
1169                                  * sessiond/consumerd connection is allocated in
1170                                  * this thread, enqueued to a global queue and
1171                                  * dequeued (and freed) in the worker thread.
1172                                  */
1173                                 int val = 1;
1174                                 struct relay_connection *new_conn;
1175                                 struct lttcomm_sock *newsock = NULL;
1176                                 enum connection_type type;
1177
1178                                 if (pollfd == data_sock->fd) {
1179                                         type = RELAY_DATA;
1180                                         newsock = accept_relayd_sock(data_sock,
1181                                                         "Data socket to relayd");
1182                                 } else {
1183                                         assert(pollfd == control_sock->fd);
1184                                         type = RELAY_CONTROL;
1185                                         newsock = accept_relayd_sock(control_sock,
1186                                                         "Control socket to relayd");
1187                                 }
1188                                 if (!newsock) {
1189                                         PERROR("accepting sock");
1190                                         goto error;
1191                                 }
1192
1193                                 ret = setsockopt(newsock->fd, SOL_SOCKET, SO_REUSEADDR, &val,
1194                                                 sizeof(val));
1195                                 if (ret < 0) {
1196                                         PERROR("setsockopt inet");
1197                                         lttcomm_destroy_sock(newsock);
1198                                         goto error;
1199                                 }
1200
1201                                 ret = socket_apply_keep_alive_config(newsock->fd);
1202                                 if (ret < 0) {
1203                                         ERR("Failed to apply TCP keep-alive configuration on socket (%i)",
1204                                                         newsock->fd);
1205                                         lttcomm_destroy_sock(newsock);
1206                                         goto error;
1207                                 }
1208
1209                                 new_conn = connection_create(newsock, type);
1210                                 if (!new_conn) {
1211                                         lttcomm_destroy_sock(newsock);
1212                                         goto error;
1213                                 }
1214
1215                                 /* Enqueue request for the dispatcher thread. */
1216                                 cds_wfcq_enqueue(&relay_conn_queue.head, &relay_conn_queue.tail,
1217                                                  &new_conn->qnode);
1218
1219                                 /*
1220                                  * Wake the dispatch queue futex.
1221                                  * Implicit memory barrier with the
1222                                  * exchange in cds_wfcq_enqueue.
1223                                  */
1224                                 futex_nto1_wake(&relay_conn_queue.futex);
1225                         } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1226                                 ERR("socket poll error");
1227                                 goto error;
1228                         } else {
1229                                 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
1230                                 goto error;
1231                         }
1232                 }
1233         }
1234
1235 exit:
1236 error:
1237 error_poll_add:
1238 error_testpoint:
1239         (void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
1240 error_create_poll:
1241         if (data_sock->fd >= 0) {
1242                 int data_sock_fd = data_sock->fd;
1243
1244                 ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker,
1245                                 &data_sock_fd, 1, close_sock,
1246                                 data_sock);
1247                 if (ret) {
1248                         PERROR("Failed to close the data listener socket file descriptor");
1249                 }
1250                 data_sock->fd = -1;
1251         }
1252         lttcomm_destroy_sock(data_sock);
1253 error_sock_relay:
1254         if (control_sock->fd >= 0) {
1255                 int control_sock_fd = control_sock->fd;
1256
1257                 ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker,
1258                                 &control_sock_fd, 1, close_sock,
1259                                 control_sock);
1260                 if (ret) {
1261                         PERROR("Failed to close the control listener socket file descriptor");
1262                 }
1263                 control_sock->fd = -1;
1264         }
1265         lttcomm_destroy_sock(control_sock);
1266 error_sock_control:
1267         if (err) {
1268                 health_error();
1269                 ERR("Health error occurred in %s", __func__);
1270         }
1271         health_unregister(health_relayd);
1272         rcu_unregister_thread();
1273         DBG("Relay listener thread cleanup complete");
1274         lttng_relay_stop_threads();
1275         return NULL;
1276 }
1277
1278 /*
1279  * This thread manages the dispatching of the requests to worker threads
1280  */
1281 static void *relay_thread_dispatcher(void *data)
1282 {
1283         int err = -1;
1284         ssize_t ret;
1285         struct cds_wfcq_node *node;
1286         struct relay_connection *new_conn = NULL;
1287
1288         DBG("[thread] Relay dispatcher started");
1289
1290         health_register(health_relayd, HEALTH_RELAYD_TYPE_DISPATCHER);
1291
1292         if (testpoint(relayd_thread_dispatcher)) {
1293                 goto error_testpoint;
1294         }
1295
1296         health_code_update();
1297
1298         for (;;) {
1299                 health_code_update();
1300
1301                 /* Atomically prepare the queue futex */
1302                 futex_nto1_prepare(&relay_conn_queue.futex);
1303
1304                 if (CMM_LOAD_SHARED(dispatch_thread_exit)) {
1305                         break;
1306                 }
1307
1308                 do {
1309                         health_code_update();
1310
1311                         /* Dequeue commands */
1312                         node = cds_wfcq_dequeue_blocking(&relay_conn_queue.head,
1313                                                          &relay_conn_queue.tail);
1314                         if (node == NULL) {
1315                                 DBG("Woken up but nothing in the relay command queue");
1316                                 /* Continue thread execution */
1317                                 break;
1318                         }
1319                         new_conn = caa_container_of(node, struct relay_connection, qnode);
1320
1321                         DBG("Dispatching request waiting on sock %d", new_conn->sock->fd);
1322
1323                         /*
1324                          * Inform worker thread of the new request. This
1325                          * call is blocking so we can be assured that
1326                          * the data will be read at some point in time
1327                          * or wait to the end of the world :)
1328                          */
1329                         ret = lttng_write(relay_conn_pipe[1], &new_conn, sizeof(new_conn));
1330                         if (ret < 0) {
1331                                 PERROR("write connection pipe");
1332                                 connection_put(new_conn);
1333                                 goto error;
1334                         }
1335                 } while (node != NULL);
1336
1337                 /* Futex wait on queue. Blocking call on futex() */
1338                 health_poll_entry();
1339                 futex_nto1_wait(&relay_conn_queue.futex);
1340                 health_poll_exit();
1341         }
1342
1343         /* Normal exit, no error */
1344         err = 0;
1345
1346 error:
1347 error_testpoint:
1348         if (err) {
1349                 health_error();
1350                 ERR("Health error occurred in %s", __func__);
1351         }
1352         health_unregister(health_relayd);
1353         DBG("Dispatch thread dying");
1354         lttng_relay_stop_threads();
1355         return NULL;
1356 }
1357
1358 static bool session_streams_have_index(const struct relay_session *session)
1359 {
1360         return session->minor >= 4 && !session->snapshot;
1361 }
1362
1363 /*
1364  * Handle the RELAYD_CREATE_SESSION command.
1365  *
1366  * On success, send back the session id or else return a negative value.
1367  */
1368 static int relay_create_session(const struct lttcomm_relayd_hdr *recv_hdr,
1369                 struct relay_connection *conn,
1370                 const struct lttng_buffer_view *payload)
1371 {
1372         int ret = 0;
1373         ssize_t send_ret;
1374         struct relay_session *session = NULL;
1375         struct lttcomm_relayd_create_session_reply_2_11 reply = {};
1376         char session_name[LTTNG_NAME_MAX] = {};
1377         char hostname[LTTNG_HOST_NAME_MAX] = {};
1378         uint32_t live_timer = 0;
1379         bool snapshot = false;
1380         bool session_name_contains_creation_timestamp = false;
1381         /* Left nil for peers < 2.11. */
1382         char base_path[LTTNG_PATH_MAX] = {};
1383         lttng_uuid sessiond_uuid = {};
1384         LTTNG_OPTIONAL(uint64_t) id_sessiond = {};
1385         LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1386         LTTNG_OPTIONAL(time_t) creation_time = {};
1387         struct lttng_dynamic_buffer reply_payload;
1388
1389         lttng_dynamic_buffer_init(&reply_payload);
1390
1391         if (conn->minor < 4) {
1392                 /* From 2.1 to 2.3 */
1393                 ret = 0;
1394         } else if (conn->minor >= 4 && conn->minor < 11) {
1395                 /* From 2.4 to 2.10 */
1396                 ret = cmd_create_session_2_4(payload, session_name,
1397                         hostname, &live_timer, &snapshot);
1398         } else {
1399                 bool has_current_chunk;
1400                 uint64_t current_chunk_id_value;
1401                 time_t creation_time_value;
1402                 uint64_t id_sessiond_value;
1403
1404                 /* From 2.11 to ... */
1405                 ret = cmd_create_session_2_11(payload, session_name, hostname,
1406                                 base_path, &live_timer, &snapshot, &id_sessiond_value,
1407                                 sessiond_uuid, &has_current_chunk,
1408                                 &current_chunk_id_value, &creation_time_value,
1409                                 &session_name_contains_creation_timestamp);
1410                 if (lttng_uuid_is_nil(sessiond_uuid)) {
1411                         /* The nil UUID is reserved for pre-2.11 clients. */
1412                         ERR("Illegal nil UUID announced by peer in create session command");
1413                         ret = -1;
1414                         goto send_reply;
1415                 }
1416                 LTTNG_OPTIONAL_SET(&id_sessiond, id_sessiond_value);
1417                 LTTNG_OPTIONAL_SET(&creation_time, creation_time_value);
1418                 if (has_current_chunk) {
1419                         LTTNG_OPTIONAL_SET(&current_chunk_id,
1420                                         current_chunk_id_value);
1421                 }
1422         }
1423
1424         if (ret < 0) {
1425                 goto send_reply;
1426         }
1427
1428         session = session_create(session_name, hostname, base_path, live_timer,
1429                         snapshot, sessiond_uuid,
1430                         id_sessiond.is_set ? &id_sessiond.value : NULL,
1431                         current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1432                         creation_time.is_set ? &creation_time.value : NULL,
1433                         conn->major, conn->minor,
1434                         session_name_contains_creation_timestamp);
1435         if (!session) {
1436                 ret = -1;
1437                 goto send_reply;
1438         }
1439         assert(!conn->session);
1440         conn->session = session;
1441         DBG("Created session %" PRIu64, session->id);
1442
1443         reply.generic.session_id = htobe64(session->id);
1444
1445 send_reply:
1446         if (ret < 0) {
1447                 reply.generic.ret_code = htobe32(LTTNG_ERR_FATAL);
1448         } else {
1449                 reply.generic.ret_code = htobe32(LTTNG_OK);
1450         }
1451
1452         if (conn->minor < 11) {
1453                 /* From 2.1 to 2.10 */
1454                 ret = lttng_dynamic_buffer_append(&reply_payload,
1455                                 &reply.generic, sizeof(reply.generic));
1456                 if (ret) {
1457                         ERR("Failed to append \"create session\" command reply header to payload buffer");
1458                         ret = -1;
1459                         goto end;
1460                 }
1461         } else {
1462                 const uint32_t output_path_length =
1463                                 session ? strlen(session->output_path) + 1 : 0;
1464
1465                 reply.output_path_length = htobe32(output_path_length);
1466                 ret = lttng_dynamic_buffer_append(
1467                                 &reply_payload, &reply, sizeof(reply));
1468                 if (ret) {
1469                         ERR("Failed to append \"create session\" command reply header to payload buffer");
1470                         goto end;
1471                 }
1472
1473                 if (output_path_length) {
1474                         ret = lttng_dynamic_buffer_append(&reply_payload,
1475                                         session->output_path,
1476                                         output_path_length);
1477                         if (ret) {
1478                                 ERR("Failed to append \"create session\" command reply path to payload buffer");
1479                                 goto end;
1480                         }
1481                 }
1482         }
1483
1484         send_ret = conn->sock->ops->sendmsg(conn->sock, reply_payload.data,
1485                         reply_payload.size, 0);
1486         if (send_ret < (ssize_t) reply_payload.size) {
1487                 ERR("Failed to send \"create session\" command reply of %zu bytes (ret = %zd)",
1488                                 reply_payload.size, send_ret);
1489                 ret = -1;
1490         }
1491 end:
1492         if (ret < 0 && session) {
1493                 session_put(session);
1494         }
1495         lttng_dynamic_buffer_reset(&reply_payload);
1496         return ret;
1497 }
1498
1499 /*
1500  * When we have received all the streams and the metadata for a channel,
1501  * we make them visible to the viewer threads.
1502  */
1503 static void publish_connection_local_streams(struct relay_connection *conn)
1504 {
1505         struct relay_stream *stream;
1506         struct relay_session *session = conn->session;
1507
1508         /*
1509          * We publish all streams belonging to a session atomically wrt
1510          * session lock.
1511          */
1512         pthread_mutex_lock(&session->lock);
1513         rcu_read_lock();
1514         cds_list_for_each_entry_rcu(stream, &session->recv_list,
1515                         recv_node) {
1516                 stream_publish(stream);
1517         }
1518         rcu_read_unlock();
1519
1520         /*
1521          * Inform the viewer that there are new streams in the session.
1522          */
1523         if (session->viewer_attached) {
1524                 uatomic_set(&session->new_streams, 1);
1525         }
1526         pthread_mutex_unlock(&session->lock);
1527 }
1528
1529 static int conform_channel_path(char *channel_path)
1530 {
1531         int ret = 0;
1532
1533         if (strstr("../", channel_path)) {
1534                 ERR("Refusing channel path as it walks up the path hierarchy: \"%s\"",
1535                                 channel_path);
1536                 ret = -1;
1537                 goto end;
1538         }
1539
1540         if (*channel_path == '/') {
1541                 const size_t len = strlen(channel_path);
1542
1543                 /*
1544                  * Channel paths from peers prior to 2.11 are expressed as an
1545                  * absolute path that is, in reality, relative to the relay
1546                  * daemon's output directory. Remove the leading slash so it
1547                  * is correctly interpreted as a relative path later on.
1548                  *
1549                  * len (and not len - 1) is used to copy the trailing NULL.
1550                  */
1551                 bcopy(channel_path + 1, channel_path, len);
1552         }
1553 end:
1554         return ret;
1555 }
1556
1557 /*
1558  * relay_add_stream: allocate a new stream for a session
1559  */
1560 static int relay_add_stream(const struct lttcomm_relayd_hdr *recv_hdr,
1561                 struct relay_connection *conn,
1562                 const struct lttng_buffer_view *payload)
1563 {
1564         int ret;
1565         ssize_t send_ret;
1566         struct relay_session *session = conn->session;
1567         struct relay_stream *stream = NULL;
1568         struct lttcomm_relayd_status_stream reply;
1569         struct ctf_trace *trace = NULL;
1570         uint64_t stream_handle = -1ULL;
1571         char *path_name = NULL, *channel_name = NULL;
1572         uint64_t tracefile_size = 0, tracefile_count = 0;
1573         LTTNG_OPTIONAL(uint64_t) stream_chunk_id = {};
1574
1575         if (!session || !conn->version_check_done) {
1576                 ERR("Trying to add a stream before version check");
1577                 ret = -1;
1578                 goto end_no_session;
1579         }
1580
1581         if (session->minor == 1) {
1582                 /* For 2.1 */
1583                 ret = cmd_recv_stream_2_1(payload, &path_name,
1584                         &channel_name);
1585         } else if (session->minor > 1 && session->minor < 11) {
1586                 /* From 2.2 to 2.10 */
1587                 ret = cmd_recv_stream_2_2(payload, &path_name,
1588                         &channel_name, &tracefile_size, &tracefile_count);
1589         } else {
1590                 /* From 2.11 to ... */
1591                 ret = cmd_recv_stream_2_11(payload, &path_name,
1592                         &channel_name, &tracefile_size, &tracefile_count,
1593                         &stream_chunk_id.value);
1594                 stream_chunk_id.is_set = true;
1595         }
1596
1597         if (ret < 0) {
1598                 goto send_reply;
1599         }
1600
1601         if (conform_channel_path(path_name)) {
1602                 goto send_reply;
1603         }
1604
1605         /*
1606          * Backward compatibility for --group-output-by-session.
1607          * Prior to lttng 2.11, the complete path is passed by the stream.
1608          * Starting at 2.11, lttng-relayd uses chunk. When dealing with producer
1609          * >=2.11 the chunk is responsible for the output path. When dealing
1610          * with producer < 2.11 the chunk output_path is the root output path
1611          * and the stream carries the complete path (path_name).
1612          * To support --group-output-by-session with older producer (<2.11), we
1613          * need to craft the path based on the stream path.
1614          */
1615         if (opt_group_output_by == RELAYD_GROUP_OUTPUT_BY_SESSION) {
1616                 if (conn->minor < 4) {
1617                         /*
1618                          * From 2.1 to 2.3, the session_name is not passed on
1619                          * the RELAYD_CREATE_SESSION command. The session name
1620                          * is necessary to detect the presence of a base_path
1621                          * inside the stream path. Without it we cannot perform
1622                          * a valid group-output-by-session transformation.
1623                          */
1624                         WARN("Unable to perform a --group-by-session transformation for session %" PRIu64
1625                              " for stream with path \"%s\" as it is produced by a peer using a protocol older than v2.4",
1626                                         session->id, path_name);
1627                 } else if (conn->minor >= 4 && conn->minor < 11) {
1628                         char *group_by_session_path_name;
1629
1630                         assert(session->session_name[0] != '\0');
1631
1632                         group_by_session_path_name =
1633                                         backward_compat_group_by_session(
1634                                                         path_name,
1635                                                         session->session_name,
1636                                                         session->creation_time.value);
1637                         if (!group_by_session_path_name) {
1638                                 ERR("Failed to apply group by session to stream of session %" PRIu64,
1639                                                 session->id);
1640                                 goto send_reply;
1641                         }
1642
1643                         DBG("Transformed session path from \"%s\" to \"%s\" to honor per-session name grouping",
1644                                         path_name, group_by_session_path_name);
1645
1646                         free(path_name);
1647                         path_name = group_by_session_path_name;
1648                 }
1649         }
1650
1651         trace = ctf_trace_get_by_path_or_create(session, path_name);
1652         if (!trace) {
1653                 goto send_reply;
1654         }
1655
1656         /* This stream here has one reference on the trace. */
1657         pthread_mutex_lock(&last_relay_stream_id_lock);
1658         stream_handle = ++last_relay_stream_id;
1659         pthread_mutex_unlock(&last_relay_stream_id_lock);
1660
1661         /* We pass ownership of path_name and channel_name. */
1662         stream = stream_create(trace, stream_handle, path_name,
1663                 channel_name, tracefile_size, tracefile_count);
1664         path_name = NULL;
1665         channel_name = NULL;
1666
1667         /*
1668          * Streams are the owners of their trace. Reference to trace is
1669          * kept within stream_create().
1670          */
1671         ctf_trace_put(trace);
1672
1673 send_reply:
1674         memset(&reply, 0, sizeof(reply));
1675         reply.handle = htobe64(stream_handle);
1676         if (!stream) {
1677                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1678         } else {
1679                 reply.ret_code = htobe32(LTTNG_OK);
1680         }
1681
1682         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
1683                         sizeof(struct lttcomm_relayd_status_stream), 0);
1684         if (send_ret < (ssize_t) sizeof(reply)) {
1685                 ERR("Failed to send \"add stream\" command reply (ret = %zd)",
1686                                 send_ret);
1687                 ret = -1;
1688         }
1689
1690 end_no_session:
1691         free(path_name);
1692         free(channel_name);
1693         return ret;
1694 }
1695
1696 /*
1697  * relay_close_stream: close a specific stream
1698  */
1699 static int relay_close_stream(const struct lttcomm_relayd_hdr *recv_hdr,
1700                 struct relay_connection *conn,
1701                 const struct lttng_buffer_view *payload)
1702 {
1703         int ret;
1704         ssize_t send_ret;
1705         struct relay_session *session = conn->session;
1706         struct lttcomm_relayd_close_stream stream_info;
1707         struct lttcomm_relayd_generic_reply reply;
1708         struct relay_stream *stream;
1709
1710         DBG("Close stream received");
1711
1712         if (!session || !conn->version_check_done) {
1713                 ERR("Trying to close a stream before version check");
1714                 ret = -1;
1715                 goto end_no_session;
1716         }
1717
1718         if (payload->size < sizeof(stream_info)) {
1719                 ERR("Unexpected payload size in \"relay_close_stream\": expected >= %zu bytes, got %zu bytes",
1720                                 sizeof(stream_info), payload->size);
1721                 ret = -1;
1722                 goto end_no_session;
1723         }
1724         memcpy(&stream_info, payload->data, sizeof(stream_info));
1725         stream_info.stream_id = be64toh(stream_info.stream_id);
1726         stream_info.last_net_seq_num = be64toh(stream_info.last_net_seq_num);
1727
1728         stream = stream_get_by_id(stream_info.stream_id);
1729         if (!stream) {
1730                 ret = -1;
1731                 goto end;
1732         }
1733
1734         /*
1735          * Set last_net_seq_num before the close flag. Required by data
1736          * pending check.
1737          */
1738         pthread_mutex_lock(&stream->lock);
1739         stream->last_net_seq_num = stream_info.last_net_seq_num;
1740         pthread_mutex_unlock(&stream->lock);
1741
1742         /*
1743          * This is one of the conditions which may trigger a stream close
1744          * with the others being:
1745          *     1) A close command is received for a stream
1746          *     2) The control connection owning the stream is closed
1747          *     3) We have received all of the stream's data _after_ a close
1748          *        request.
1749          */
1750         try_stream_close(stream);
1751         if (stream->is_metadata) {
1752                 struct relay_viewer_stream *vstream;
1753
1754                 vstream = viewer_stream_get_by_id(stream->stream_handle);
1755                 if (vstream) {
1756                         if (stream->no_new_metadata_notified) {
1757                                 /*
1758                                  * Since all the metadata has been sent to the
1759                                  * viewer and that we have a request to close
1760                                  * its stream, we can safely teardown the
1761                                  * corresponding metadata viewer stream.
1762                                  */
1763                                 viewer_stream_put(vstream);
1764                         }
1765                         /* Put local reference. */
1766                         viewer_stream_put(vstream);
1767                 }
1768         }
1769         stream_put(stream);
1770         ret = 0;
1771
1772 end:
1773         memset(&reply, 0, sizeof(reply));
1774         if (ret < 0) {
1775                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1776         } else {
1777                 reply.ret_code = htobe32(LTTNG_OK);
1778         }
1779         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
1780                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1781         if (send_ret < (ssize_t) sizeof(reply)) {
1782                 ERR("Failed to send \"close stream\" command reply (ret = %zd)",
1783                                 send_ret);
1784                 ret = -1;
1785         }
1786
1787 end_no_session:
1788         return ret;
1789 }
1790
1791 /*
1792  * relay_reset_metadata: reset a metadata stream
1793  */
1794 static
1795 int relay_reset_metadata(const struct lttcomm_relayd_hdr *recv_hdr,
1796                 struct relay_connection *conn,
1797                 const struct lttng_buffer_view *payload)
1798 {
1799         int ret;
1800         ssize_t send_ret;
1801         struct relay_session *session = conn->session;
1802         struct lttcomm_relayd_reset_metadata stream_info;
1803         struct lttcomm_relayd_generic_reply reply;
1804         struct relay_stream *stream;
1805
1806         DBG("Reset metadata received");
1807
1808         if (!session || !conn->version_check_done) {
1809                 ERR("Trying to reset a metadata stream before version check");
1810                 ret = -1;
1811                 goto end_no_session;
1812         }
1813
1814         if (payload->size < sizeof(stream_info)) {
1815                 ERR("Unexpected payload size in \"relay_reset_metadata\": expected >= %zu bytes, got %zu bytes",
1816                                 sizeof(stream_info), payload->size);
1817                 ret = -1;
1818                 goto end_no_session;
1819         }
1820         memcpy(&stream_info, payload->data, sizeof(stream_info));
1821         stream_info.stream_id = be64toh(stream_info.stream_id);
1822         stream_info.version = be64toh(stream_info.version);
1823
1824         DBG("Update metadata to version %" PRIu64, stream_info.version);
1825
1826         /* Unsupported for live sessions for now. */
1827         if (session->live_timer != 0) {
1828                 ret = -1;
1829                 goto end;
1830         }
1831
1832         stream = stream_get_by_id(stream_info.stream_id);
1833         if (!stream) {
1834                 ret = -1;
1835                 goto end;
1836         }
1837         pthread_mutex_lock(&stream->lock);
1838         if (!stream->is_metadata) {
1839                 ret = -1;
1840                 goto end_unlock;
1841         }
1842
1843         ret = stream_reset_file(stream);
1844         if (ret < 0) {
1845                 ERR("Failed to reset metadata stream %" PRIu64
1846                                 ": stream_path = %s, channel = %s",
1847                                 stream->stream_handle, stream->path_name,
1848                                 stream->channel_name);
1849                 goto end_unlock;
1850         }
1851 end_unlock:
1852         pthread_mutex_unlock(&stream->lock);
1853         stream_put(stream);
1854
1855 end:
1856         memset(&reply, 0, sizeof(reply));
1857         if (ret < 0) {
1858                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1859         } else {
1860                 reply.ret_code = htobe32(LTTNG_OK);
1861         }
1862         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
1863                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1864         if (send_ret < (ssize_t) sizeof(reply)) {
1865                 ERR("Failed to send \"reset metadata\" command reply (ret = %zd)",
1866                                 send_ret);
1867                 ret = -1;
1868         }
1869
1870 end_no_session:
1871         return ret;
1872 }
1873
1874 /*
1875  * relay_unknown_command: send -1 if received unknown command
1876  */
1877 static void relay_unknown_command(struct relay_connection *conn)
1878 {
1879         struct lttcomm_relayd_generic_reply reply;
1880         ssize_t send_ret;
1881
1882         memset(&reply, 0, sizeof(reply));
1883         reply.ret_code = htobe32(LTTNG_ERR_UNK);
1884         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
1885         if (send_ret < sizeof(reply)) {
1886                 ERR("Failed to send \"unknown command\" command reply (ret = %zd)", send_ret);
1887         }
1888 }
1889
1890 /*
1891  * relay_start: send an acknowledgment to the client to tell if we are
1892  * ready to receive data. We are ready if a session is established.
1893  */
1894 static int relay_start(const struct lttcomm_relayd_hdr *recv_hdr,
1895                 struct relay_connection *conn,
1896                 const struct lttng_buffer_view *payload)
1897 {
1898         int ret = 0;
1899         ssize_t send_ret;
1900         struct lttcomm_relayd_generic_reply reply;
1901         struct relay_session *session = conn->session;
1902
1903         if (!session) {
1904                 DBG("Trying to start the streaming without a session established");
1905                 ret = htobe32(LTTNG_ERR_UNK);
1906         }
1907
1908         memset(&reply, 0, sizeof(reply));
1909         reply.ret_code = htobe32(LTTNG_OK);
1910         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
1911                         sizeof(reply), 0);
1912         if (send_ret < (ssize_t) sizeof(reply)) {
1913                 ERR("Failed to send \"relay_start\" command reply (ret = %zd)",
1914                                 send_ret);
1915                 ret = -1;
1916         }
1917
1918         return ret;
1919 }
1920
1921 /*
1922  * relay_recv_metadata: receive the metadata for the session.
1923  */
1924 static int relay_recv_metadata(const struct lttcomm_relayd_hdr *recv_hdr,
1925                 struct relay_connection *conn,
1926                 const struct lttng_buffer_view *payload)
1927 {
1928         int ret = 0;
1929         struct relay_session *session = conn->session;
1930         struct lttcomm_relayd_metadata_payload metadata_payload_header;
1931         struct relay_stream *metadata_stream;
1932         uint64_t metadata_payload_size;
1933         struct lttng_buffer_view packet_view;
1934
1935         if (!session) {
1936                 ERR("Metadata sent before version check");
1937                 ret = -1;
1938                 goto end;
1939         }
1940
1941         if (recv_hdr->data_size < sizeof(struct lttcomm_relayd_metadata_payload)) {
1942                 ERR("Incorrect data size");
1943                 ret = -1;
1944                 goto end;
1945         }
1946         metadata_payload_size = recv_hdr->data_size -
1947                         sizeof(struct lttcomm_relayd_metadata_payload);
1948
1949         memcpy(&metadata_payload_header, payload->data,
1950                         sizeof(metadata_payload_header));
1951         metadata_payload_header.stream_id = be64toh(
1952                         metadata_payload_header.stream_id);
1953         metadata_payload_header.padding_size = be32toh(
1954                         metadata_payload_header.padding_size);
1955
1956         metadata_stream = stream_get_by_id(metadata_payload_header.stream_id);
1957         if (!metadata_stream) {
1958                 ret = -1;
1959                 goto end;
1960         }
1961
1962         packet_view = lttng_buffer_view_from_view(payload,
1963                         sizeof(metadata_payload_header), metadata_payload_size);
1964         if (!packet_view.data) {
1965                 ERR("Invalid metadata packet length announced by header");
1966                 ret = -1;
1967                 goto end_put;
1968         }
1969
1970         pthread_mutex_lock(&metadata_stream->lock);
1971         ret = stream_write(metadata_stream, &packet_view,
1972                         metadata_payload_header.padding_size);
1973         pthread_mutex_unlock(&metadata_stream->lock);
1974         if (ret){
1975                 ret = -1;
1976                 goto end_put;
1977         }
1978 end_put:
1979         stream_put(metadata_stream);
1980 end:
1981         return ret;
1982 }
1983
1984 /*
1985  * relay_send_version: send relayd version number
1986  */
1987 static int relay_send_version(const struct lttcomm_relayd_hdr *recv_hdr,
1988                 struct relay_connection *conn,
1989                 const struct lttng_buffer_view *payload)
1990 {
1991         int ret;
1992         ssize_t send_ret;
1993         struct lttcomm_relayd_version reply, msg;
1994         bool compatible = true;
1995
1996         conn->version_check_done = true;
1997
1998         /* Get version from the other side. */
1999         if (payload->size < sizeof(msg)) {
2000                 ERR("Unexpected payload size in \"relay_send_version\": expected >= %zu bytes, got %zu bytes",
2001                                 sizeof(msg), payload->size);
2002                 ret = -1;
2003                 goto end;
2004         }
2005
2006         memcpy(&msg, payload->data, sizeof(msg));
2007         msg.major = be32toh(msg.major);
2008         msg.minor = be32toh(msg.minor);
2009
2010         memset(&reply, 0, sizeof(reply));
2011         reply.major = RELAYD_VERSION_COMM_MAJOR;
2012         reply.minor = RELAYD_VERSION_COMM_MINOR;
2013
2014         /* Major versions must be the same */
2015         if (reply.major != msg.major) {
2016                 DBG("Incompatible major versions (%u vs %u), deleting session",
2017                                 reply.major, msg.major);
2018                 compatible = false;
2019         }
2020
2021         conn->major = reply.major;
2022         /* We adapt to the lowest compatible version */
2023         if (reply.minor <= msg.minor) {
2024                 conn->minor = reply.minor;
2025         } else {
2026                 conn->minor = msg.minor;
2027         }
2028
2029         reply.major = htobe32(reply.major);
2030         reply.minor = htobe32(reply.minor);
2031         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
2032                         sizeof(reply), 0);
2033         if (send_ret < (ssize_t) sizeof(reply)) {
2034                 ERR("Failed to send \"send version\" command reply (ret = %zd)",
2035                                 send_ret);
2036                 ret = -1;
2037                 goto end;
2038         } else {
2039                 ret = 0;
2040         }
2041
2042         if (!compatible) {
2043                 ret = -1;
2044                 goto end;
2045         }
2046
2047         DBG("Version check done using protocol %u.%u", conn->major,
2048                         conn->minor);
2049
2050 end:
2051         return ret;
2052 }
2053
2054 /*
2055  * Check for data pending for a given stream id from the session daemon.
2056  */
2057 static int relay_data_pending(const struct lttcomm_relayd_hdr *recv_hdr,
2058                 struct relay_connection *conn,
2059                 const struct lttng_buffer_view *payload)
2060 {
2061         struct relay_session *session = conn->session;
2062         struct lttcomm_relayd_data_pending msg;
2063         struct lttcomm_relayd_generic_reply reply;
2064         struct relay_stream *stream;
2065         ssize_t send_ret;
2066         int ret;
2067         uint64_t stream_seq;
2068
2069         DBG("Data pending command received");
2070
2071         if (!session || !conn->version_check_done) {
2072                 ERR("Trying to check for data before version check");
2073                 ret = -1;
2074                 goto end_no_session;
2075         }
2076
2077         if (payload->size < sizeof(msg)) {
2078                 ERR("Unexpected payload size in \"relay_data_pending\": expected >= %zu bytes, got %zu bytes",
2079                                 sizeof(msg), payload->size);
2080                 ret = -1;
2081                 goto end_no_session;
2082         }
2083         memcpy(&msg, payload->data, sizeof(msg));
2084         msg.stream_id = be64toh(msg.stream_id);
2085         msg.last_net_seq_num = be64toh(msg.last_net_seq_num);
2086
2087         stream = stream_get_by_id(msg.stream_id);
2088         if (stream == NULL) {
2089                 ret = -1;
2090                 goto end;
2091         }
2092
2093         pthread_mutex_lock(&stream->lock);
2094
2095         if (session_streams_have_index(session)) {
2096                 /*
2097                  * Ensure that both the index and stream data have been
2098                  * flushed up to the requested point.
2099                  */
2100                 stream_seq = min(stream->prev_data_seq, stream->prev_index_seq);
2101         } else {
2102                 stream_seq = stream->prev_data_seq;
2103         }
2104         DBG("Data pending for stream id %" PRIu64 ": prev_data_seq %" PRIu64
2105                         ", prev_index_seq %" PRIu64
2106                         ", and last_seq %" PRIu64, msg.stream_id,
2107                         stream->prev_data_seq, stream->prev_index_seq,
2108                         msg.last_net_seq_num);
2109
2110         /* Avoid wrapping issue */
2111         if (((int64_t) (stream_seq - msg.last_net_seq_num)) >= 0) {
2112                 /* Data has in fact been written and is NOT pending */
2113                 ret = 0;
2114         } else {
2115                 /* Data still being streamed thus pending */
2116                 ret = 1;
2117         }
2118
2119         stream->data_pending_check_done = true;
2120         pthread_mutex_unlock(&stream->lock);
2121
2122         stream_put(stream);
2123 end:
2124
2125         memset(&reply, 0, sizeof(reply));
2126         reply.ret_code = htobe32(ret);
2127         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2128         if (send_ret < (ssize_t) sizeof(reply)) {
2129                 ERR("Failed to send \"data pending\" command reply (ret = %zd)",
2130                                 send_ret);
2131                 ret = -1;
2132         }
2133
2134 end_no_session:
2135         return ret;
2136 }
2137
2138 /*
2139  * Wait for the control socket to reach a quiescent state.
2140  *
2141  * Note that for now, when receiving this command from the session
2142  * daemon, this means that every subsequent commands or data received on
2143  * the control socket has been handled. So, this is why we simply return
2144  * OK here.
2145  */
2146 static int relay_quiescent_control(const struct lttcomm_relayd_hdr *recv_hdr,
2147                 struct relay_connection *conn,
2148                 const struct lttng_buffer_view *payload)
2149 {
2150         int ret;
2151         ssize_t send_ret;
2152         struct relay_stream *stream;
2153         struct lttcomm_relayd_quiescent_control msg;
2154         struct lttcomm_relayd_generic_reply reply;
2155
2156         DBG("Checking quiescent state on control socket");
2157
2158         if (!conn->session || !conn->version_check_done) {
2159                 ERR("Trying to check for data before version check");
2160                 ret = -1;
2161                 goto end_no_session;
2162         }
2163
2164         if (payload->size < sizeof(msg)) {
2165                 ERR("Unexpected payload size in \"relay_quiescent_control\": expected >= %zu bytes, got %zu bytes",
2166                                 sizeof(msg), payload->size);
2167                 ret = -1;
2168                 goto end_no_session;
2169         }
2170         memcpy(&msg, payload->data, sizeof(msg));
2171         msg.stream_id = be64toh(msg.stream_id);
2172
2173         stream = stream_get_by_id(msg.stream_id);
2174         if (!stream) {
2175                 goto reply;
2176         }
2177         pthread_mutex_lock(&stream->lock);
2178         stream->data_pending_check_done = true;
2179         pthread_mutex_unlock(&stream->lock);
2180
2181         DBG("Relay quiescent control pending flag set to %" PRIu64, msg.stream_id);
2182         stream_put(stream);
2183 reply:
2184         memset(&reply, 0, sizeof(reply));
2185         reply.ret_code = htobe32(LTTNG_OK);
2186         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2187         if (send_ret < (ssize_t) sizeof(reply)) {
2188                 ERR("Failed to send \"quiescent control\" command reply (ret = %zd)",
2189                                 send_ret);
2190                 ret = -1;
2191         } else {
2192                 ret = 0;
2193         }
2194
2195 end_no_session:
2196         return ret;
2197 }
2198
2199 /*
2200  * Initialize a data pending command. This means that a consumer is about
2201  * to ask for data pending for each stream it holds. Simply iterate over
2202  * all streams of a session and set the data_pending_check_done flag.
2203  *
2204  * This command returns to the client a LTTNG_OK code.
2205  */
2206 static int relay_begin_data_pending(const struct lttcomm_relayd_hdr *recv_hdr,
2207                 struct relay_connection *conn,
2208                 const struct lttng_buffer_view *payload)
2209 {
2210         int ret;
2211         ssize_t send_ret;
2212         struct lttng_ht_iter iter;
2213         struct lttcomm_relayd_begin_data_pending msg;
2214         struct lttcomm_relayd_generic_reply reply;
2215         struct relay_stream *stream;
2216
2217         assert(recv_hdr);
2218         assert(conn);
2219
2220         DBG("Init streams for data pending");
2221
2222         if (!conn->session || !conn->version_check_done) {
2223                 ERR("Trying to check for data before version check");
2224                 ret = -1;
2225                 goto end_no_session;
2226         }
2227
2228         if (payload->size < sizeof(msg)) {
2229                 ERR("Unexpected payload size in \"relay_begin_data_pending\": expected >= %zu bytes, got %zu bytes",
2230                                 sizeof(msg), payload->size);
2231                 ret = -1;
2232                 goto end_no_session;
2233         }
2234         memcpy(&msg, payload->data, sizeof(msg));
2235         msg.session_id = be64toh(msg.session_id);
2236
2237         /*
2238          * Iterate over all streams to set the begin data pending flag.
2239          * For now, the streams are indexed by stream handle so we have
2240          * to iterate over all streams to find the one associated with
2241          * the right session_id.
2242          */
2243         rcu_read_lock();
2244         cds_lfht_for_each_entry(relay_streams_ht->ht, &iter.iter, stream,
2245                         node.node) {
2246                 if (!stream_get(stream)) {
2247                         continue;
2248                 }
2249                 if (stream->trace->session->id == msg.session_id) {
2250                         pthread_mutex_lock(&stream->lock);
2251                         stream->data_pending_check_done = false;
2252                         pthread_mutex_unlock(&stream->lock);
2253                         DBG("Set begin data pending flag to stream %" PRIu64,
2254                                         stream->stream_handle);
2255                 }
2256                 stream_put(stream);
2257         }
2258         rcu_read_unlock();
2259
2260         memset(&reply, 0, sizeof(reply));
2261         /* All good, send back reply. */
2262         reply.ret_code = htobe32(LTTNG_OK);
2263
2264         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2265         if (send_ret < (ssize_t) sizeof(reply)) {
2266                 ERR("Failed to send \"begin data pending\" command reply (ret = %zd)",
2267                         send_ret);
2268                 ret = -1;
2269         } else {
2270                 ret = 0;
2271         }
2272
2273 end_no_session:
2274         return ret;
2275 }
2276
2277 /*
2278  * End data pending command. This will check, for a given session id, if
2279  * each stream associated with it has its data_pending_check_done flag
2280  * set. If not, this means that the client lost track of the stream but
2281  * the data is still being streamed on our side. In this case, we inform
2282  * the client that data is in flight.
2283  *
2284  * Return to the client if there is data in flight or not with a ret_code.
2285  */
2286 static int relay_end_data_pending(const struct lttcomm_relayd_hdr *recv_hdr,
2287                 struct relay_connection *conn,
2288                 const struct lttng_buffer_view *payload)
2289 {
2290         int ret;
2291         ssize_t send_ret;
2292         struct lttng_ht_iter iter;
2293         struct lttcomm_relayd_end_data_pending msg;
2294         struct lttcomm_relayd_generic_reply reply;
2295         struct relay_stream *stream;
2296         uint32_t is_data_inflight = 0;
2297
2298         DBG("End data pending command");
2299
2300         if (!conn->session || !conn->version_check_done) {
2301                 ERR("Trying to check for data before version check");
2302                 ret = -1;
2303                 goto end_no_session;
2304         }
2305
2306         if (payload->size < sizeof(msg)) {
2307                 ERR("Unexpected payload size in \"relay_end_data_pending\": expected >= %zu bytes, got %zu bytes",
2308                                 sizeof(msg), payload->size);
2309                 ret = -1;
2310                 goto end_no_session;
2311         }
2312         memcpy(&msg, payload->data, sizeof(msg));
2313         msg.session_id = be64toh(msg.session_id);
2314
2315         /*
2316          * Iterate over all streams to see if the begin data pending
2317          * flag is set.
2318          */
2319         rcu_read_lock();
2320         cds_lfht_for_each_entry(relay_streams_ht->ht, &iter.iter, stream,
2321                         node.node) {
2322                 if (!stream_get(stream)) {
2323                         continue;
2324                 }
2325                 if (stream->trace->session->id != msg.session_id) {
2326                         stream_put(stream);
2327                         continue;
2328                 }
2329                 pthread_mutex_lock(&stream->lock);
2330                 if (!stream->data_pending_check_done) {
2331                         uint64_t stream_seq;
2332
2333                         if (session_streams_have_index(conn->session)) {
2334                                 /*
2335                                  * Ensure that both the index and stream data have been
2336                                  * flushed up to the requested point.
2337                                  */
2338                                 stream_seq = min(stream->prev_data_seq, stream->prev_index_seq);
2339                         } else {
2340                                 stream_seq = stream->prev_data_seq;
2341                         }
2342                         if (!stream->closed || !(((int64_t) (stream_seq - stream->last_net_seq_num)) >= 0)) {
2343                                 is_data_inflight = 1;
2344                                 DBG("Data is still in flight for stream %" PRIu64,
2345                                                 stream->stream_handle);
2346                                 pthread_mutex_unlock(&stream->lock);
2347                                 stream_put(stream);
2348                                 break;
2349                         }
2350                 }
2351                 pthread_mutex_unlock(&stream->lock);
2352                 stream_put(stream);
2353         }
2354         rcu_read_unlock();
2355
2356         memset(&reply, 0, sizeof(reply));
2357         /* All good, send back reply. */
2358         reply.ret_code = htobe32(is_data_inflight);
2359
2360         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2361         if (send_ret < (ssize_t) sizeof(reply)) {
2362                 ERR("Failed to send \"end data pending\" command reply (ret = %zd)",
2363                         send_ret);
2364                 ret = -1;
2365         } else {
2366                 ret = 0;
2367         }
2368
2369 end_no_session:
2370         return ret;
2371 }
2372
2373 /*
2374  * Receive an index for a specific stream.
2375  *
2376  * Return 0 on success else a negative value.
2377  */
2378 static int relay_recv_index(const struct lttcomm_relayd_hdr *recv_hdr,
2379                 struct relay_connection *conn,
2380                 const struct lttng_buffer_view *payload)
2381 {
2382         int ret;
2383         ssize_t send_ret;
2384         struct relay_session *session = conn->session;
2385         struct lttcomm_relayd_index index_info;
2386         struct lttcomm_relayd_generic_reply reply;
2387         struct relay_stream *stream;
2388         size_t msg_len;
2389
2390         assert(conn);
2391
2392         DBG("Relay receiving index");
2393
2394         if (!session || !conn->version_check_done) {
2395                 ERR("Trying to close a stream before version check");
2396                 ret = -1;
2397                 goto end_no_session;
2398         }
2399
2400         msg_len = lttcomm_relayd_index_len(
2401                         lttng_to_index_major(conn->major, conn->minor),
2402                         lttng_to_index_minor(conn->major, conn->minor));
2403         if (payload->size < msg_len) {
2404                 ERR("Unexpected payload size in \"relay_recv_index\": expected >= %zu bytes, got %zu bytes",
2405                                 msg_len, payload->size);
2406                 ret = -1;
2407                 goto end_no_session;
2408         }
2409         memcpy(&index_info, payload->data, msg_len);
2410         index_info.relay_stream_id = be64toh(index_info.relay_stream_id);
2411         index_info.net_seq_num = be64toh(index_info.net_seq_num);
2412         index_info.packet_size = be64toh(index_info.packet_size);
2413         index_info.content_size = be64toh(index_info.content_size);
2414         index_info.timestamp_begin = be64toh(index_info.timestamp_begin);
2415         index_info.timestamp_end = be64toh(index_info.timestamp_end);
2416         index_info.events_discarded = be64toh(index_info.events_discarded);
2417         index_info.stream_id = be64toh(index_info.stream_id);
2418
2419         if (conn->minor >= 8) {
2420                 index_info.stream_instance_id =
2421                                 be64toh(index_info.stream_instance_id);
2422                 index_info.packet_seq_num = be64toh(index_info.packet_seq_num);
2423         } else {
2424                 index_info.stream_instance_id = -1ULL;
2425                 index_info.packet_seq_num = -1ULL;
2426         }
2427
2428         stream = stream_get_by_id(index_info.relay_stream_id);
2429         if (!stream) {
2430                 ERR("stream_get_by_id not found");
2431                 ret = -1;
2432                 goto end;
2433         }
2434
2435         pthread_mutex_lock(&stream->lock);
2436         ret = stream_add_index(stream, &index_info);
2437         pthread_mutex_unlock(&stream->lock);
2438         if (ret) {
2439                 goto end_stream_put;
2440         }
2441
2442 end_stream_put:
2443         stream_put(stream);
2444 end:
2445         memset(&reply, 0, sizeof(reply));
2446         if (ret < 0) {
2447                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
2448         } else {
2449                 reply.ret_code = htobe32(LTTNG_OK);
2450         }
2451         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2452         if (send_ret < (ssize_t) sizeof(reply)) {
2453                 ERR("Failed to send \"recv index\" command reply (ret = %zd)", send_ret);
2454                 ret = -1;
2455         }
2456
2457 end_no_session:
2458         return ret;
2459 }
2460
2461 /*
2462  * Receive the streams_sent message.
2463  *
2464  * Return 0 on success else a negative value.
2465  */
2466 static int relay_streams_sent(const struct lttcomm_relayd_hdr *recv_hdr,
2467                 struct relay_connection *conn,
2468                 const struct lttng_buffer_view *payload)
2469 {
2470         int ret;
2471         ssize_t send_ret;
2472         struct lttcomm_relayd_generic_reply reply;
2473
2474         assert(conn);
2475
2476         DBG("Relay receiving streams_sent");
2477
2478         if (!conn->session || !conn->version_check_done) {
2479                 ERR("Trying to close a stream before version check");
2480                 ret = -1;
2481                 goto end_no_session;
2482         }
2483
2484         /*
2485          * Publish every pending stream in the connection recv list which are
2486          * now ready to be used by the viewer.
2487          */
2488         publish_connection_local_streams(conn);
2489
2490         memset(&reply, 0, sizeof(reply));
2491         reply.ret_code = htobe32(LTTNG_OK);
2492         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2493         if (send_ret < (ssize_t) sizeof(reply)) {
2494                 ERR("Failed to send \"streams sent\" command reply (ret = %zd)",
2495                         send_ret);
2496                 ret = -1;
2497         } else {
2498                 /* Success. */
2499                 ret = 0;
2500         }
2501
2502 end_no_session:
2503         return ret;
2504 }
2505
2506 /*
2507  * relay_rotate_session_stream: rotate a stream to a new tracefile for the
2508  * session rotation feature (not the tracefile rotation feature).
2509  */
2510 static int relay_rotate_session_streams(
2511                 const struct lttcomm_relayd_hdr *recv_hdr,
2512                 struct relay_connection *conn,
2513                 const struct lttng_buffer_view *payload)
2514 {
2515         int ret = 0;
2516         uint32_t i;
2517         ssize_t send_ret;
2518         enum lttng_error_code reply_code = LTTNG_ERR_UNK;
2519         struct relay_session *session = conn->session;
2520         struct lttcomm_relayd_rotate_streams rotate_streams;
2521         struct lttcomm_relayd_generic_reply reply = {};
2522         struct relay_stream *stream = NULL;
2523         const size_t header_len = sizeof(struct lttcomm_relayd_rotate_streams);
2524         struct lttng_trace_chunk *next_trace_chunk = NULL;
2525         struct lttng_buffer_view stream_positions;
2526         char chunk_id_buf[MAX_INT_DEC_LEN(uint64_t)];
2527         const char *chunk_id_str = "none";
2528
2529         if (!session || !conn->version_check_done) {
2530                 ERR("Trying to rotate a stream before version check");
2531                 ret = -1;
2532                 goto end_no_reply;
2533         }
2534
2535         if (session->major == 2 && session->minor < 11) {
2536                 ERR("Unsupported feature before 2.11");
2537                 ret = -1;
2538                 goto end_no_reply;
2539         }
2540
2541         if (payload->size < header_len) {
2542                 ERR("Unexpected payload size in \"relay_rotate_session_stream\": expected >= %zu bytes, got %zu bytes",
2543                                 header_len, payload->size);
2544                 ret = -1;
2545                 goto end_no_reply;
2546         }
2547
2548         memcpy(&rotate_streams, payload->data, header_len);
2549
2550         /* Convert header to host endianness. */
2551         rotate_streams = (typeof(rotate_streams)) {
2552                 .stream_count = be32toh(rotate_streams.stream_count),
2553                 .new_chunk_id = (typeof(rotate_streams.new_chunk_id)) {
2554                         .is_set = !!rotate_streams.new_chunk_id.is_set,
2555                         .value = be64toh(rotate_streams.new_chunk_id.value),
2556                 }
2557         };
2558
2559         if (rotate_streams.new_chunk_id.is_set) {
2560                 /*
2561                  * Retrieve the trace chunk the stream must transition to. As
2562                  * per the protocol, this chunk should have been created
2563                  * before this command is received.
2564                  */
2565                 next_trace_chunk = sessiond_trace_chunk_registry_get_chunk(
2566                                 sessiond_trace_chunk_registry,
2567                                 session->sessiond_uuid, session->id,
2568                                 rotate_streams.new_chunk_id.value);
2569                 if (!next_trace_chunk) {
2570                         char uuid_str[LTTNG_UUID_STR_LEN];
2571
2572                         lttng_uuid_to_str(session->sessiond_uuid, uuid_str);
2573                         ERR("Unknown next trace chunk in ROTATE_STREAMS command: sessiond_uuid = {%s}, session_id = %" PRIu64
2574                                         ", trace_chunk_id = %" PRIu64,
2575                                         uuid_str, session->id,
2576                                         rotate_streams.new_chunk_id.value);
2577                         reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2578                         ret = -1;
2579                         goto end;
2580                 }
2581
2582                 ret = snprintf(chunk_id_buf, sizeof(chunk_id_buf), "%" PRIu64,
2583                                 rotate_streams.new_chunk_id.value);
2584                 if (ret < 0 || ret >= sizeof(chunk_id_buf)) {
2585                         chunk_id_str = "formatting error";
2586                 } else {
2587                         chunk_id_str = chunk_id_buf;
2588                 }
2589         }
2590
2591         DBG("Rotate %" PRIu32 " streams of session \"%s\" to chunk \"%s\"",
2592                         rotate_streams.stream_count, session->session_name,
2593                         chunk_id_str);
2594
2595         stream_positions = lttng_buffer_view_from_view(payload,
2596                         sizeof(rotate_streams), -1);
2597         if (!stream_positions.data ||
2598                         stream_positions.size <
2599                                         (rotate_streams.stream_count *
2600                                                         sizeof(struct lttcomm_relayd_stream_rotation_position))) {
2601                 reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2602                 ret = -1;
2603                 goto end;
2604         }
2605
2606         for (i = 0; i < rotate_streams.stream_count; i++) {
2607                 struct lttcomm_relayd_stream_rotation_position *position_comm =
2608                                 &((typeof(position_comm)) stream_positions.data)[i];
2609                 const struct lttcomm_relayd_stream_rotation_position pos = {
2610                         .stream_id = be64toh(position_comm->stream_id),
2611                         .rotate_at_seq_num = be64toh(
2612                                         position_comm->rotate_at_seq_num),
2613                 };
2614
2615                 stream = stream_get_by_id(pos.stream_id);
2616                 if (!stream) {
2617                         reply_code = LTTNG_ERR_INVALID;
2618                         ret = -1;
2619                         goto end;
2620                 }
2621
2622                 pthread_mutex_lock(&stream->lock);
2623                 ret = stream_set_pending_rotation(stream, next_trace_chunk,
2624                                 pos.rotate_at_seq_num);
2625                 pthread_mutex_unlock(&stream->lock);
2626                 if (ret) {
2627                         reply_code = LTTNG_ERR_FILE_CREATION_ERROR;
2628                         goto end;
2629                 }
2630
2631                 stream_put(stream);
2632                 stream = NULL;
2633         }
2634
2635         reply_code = LTTNG_OK;
2636         ret = 0;
2637 end:
2638         if (stream) {
2639                 stream_put(stream);
2640         }
2641
2642         reply.ret_code = htobe32((uint32_t) reply_code);
2643         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
2644                         sizeof(struct lttcomm_relayd_generic_reply), 0);
2645         if (send_ret < (ssize_t) sizeof(reply)) {
2646                 ERR("Failed to send \"rotate session stream\" command reply (ret = %zd)",
2647                                 send_ret);
2648                 ret = -1;
2649         }
2650 end_no_reply:
2651         lttng_trace_chunk_put(next_trace_chunk);
2652         return ret;
2653 }
2654
2655
2656
2657 /*
2658  * relay_create_trace_chunk: create a new trace chunk
2659  */
2660 static int relay_create_trace_chunk(const struct lttcomm_relayd_hdr *recv_hdr,
2661                 struct relay_connection *conn,
2662                 const struct lttng_buffer_view *payload)
2663 {
2664         int ret = 0;
2665         ssize_t send_ret;
2666         struct relay_session *session = conn->session;
2667         struct lttcomm_relayd_create_trace_chunk *msg;
2668         struct lttcomm_relayd_generic_reply reply = {};
2669         struct lttng_buffer_view header_view;
2670         struct lttng_buffer_view chunk_name_view;
2671         struct lttng_trace_chunk *chunk = NULL, *published_chunk = NULL;
2672         enum lttng_error_code reply_code = LTTNG_OK;
2673         enum lttng_trace_chunk_status chunk_status;
2674         const char *new_path;
2675
2676         if (!session || !conn->version_check_done) {
2677                 ERR("Trying to create a trace chunk before version check");
2678                 ret = -1;
2679                 goto end_no_reply;
2680         }
2681
2682         if (session->major == 2 && session->minor < 11) {
2683                 ERR("Chunk creation command is unsupported before 2.11");
2684                 ret = -1;
2685                 goto end_no_reply;
2686         }
2687
2688         header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
2689         if (!header_view.data) {
2690                 ERR("Failed to receive payload of chunk creation command");
2691                 ret = -1;
2692                 goto end_no_reply;
2693         }
2694
2695         /* Convert to host endianness. */
2696         msg = (typeof(msg)) header_view.data;
2697         msg->chunk_id = be64toh(msg->chunk_id);
2698         msg->creation_timestamp = be64toh(msg->creation_timestamp);
2699         msg->override_name_length = be32toh(msg->override_name_length);
2700
2701         if (session->current_trace_chunk &&
2702                         !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
2703                 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
2704                                         DEFAULT_CHUNK_TMP_OLD_DIRECTORY);
2705                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2706                         ERR("Failed to rename old chunk");
2707                         ret = -1;
2708                         reply_code = LTTNG_ERR_UNK;
2709                         goto end;
2710                 }
2711         }
2712         session->ongoing_rotation = true;
2713         if (!session->current_trace_chunk) {
2714                 if (!session->has_rotated) {
2715                         new_path = "";
2716                 } else {
2717                         new_path = NULL;
2718                 }
2719         } else {
2720                 new_path = DEFAULT_CHUNK_TMP_NEW_DIRECTORY;
2721         }
2722         chunk = lttng_trace_chunk_create(
2723                         msg->chunk_id, msg->creation_timestamp, new_path);
2724         if (!chunk) {
2725                 ERR("Failed to create trace chunk in trace chunk creation command");
2726                 ret = -1;
2727                 reply_code = LTTNG_ERR_NOMEM;
2728                 goto end;
2729         }
2730         lttng_trace_chunk_set_fd_tracker(chunk, the_fd_tracker);
2731
2732         if (msg->override_name_length) {
2733                 const char *name;
2734
2735                 chunk_name_view = lttng_buffer_view_from_view(payload,
2736                                 sizeof(*msg),
2737                                 msg->override_name_length);
2738                 name = chunk_name_view.data;
2739                 if (!name || name[msg->override_name_length - 1]) {
2740                         ERR("Failed to receive payload of chunk creation command");
2741                         ret = -1;
2742                         reply_code = LTTNG_ERR_INVALID;
2743                         goto end;
2744                 }
2745
2746                 chunk_status = lttng_trace_chunk_override_name(
2747                                 chunk, chunk_name_view.data);
2748                 switch (chunk_status) {
2749                 case LTTNG_TRACE_CHUNK_STATUS_OK:
2750                         break;
2751                 case LTTNG_TRACE_CHUNK_STATUS_INVALID_ARGUMENT:
2752                         ERR("Failed to set the name of new trace chunk in trace chunk creation command (invalid name)");
2753                         reply_code = LTTNG_ERR_INVALID;
2754                         ret = -1;
2755                         goto end;
2756                 default:
2757                         ERR("Failed to set the name of new trace chunk in trace chunk creation command (unknown error)");
2758                         reply_code = LTTNG_ERR_UNK;
2759                         ret = -1;
2760                         goto end;
2761                 }
2762         }
2763
2764         chunk_status = lttng_trace_chunk_set_credentials_current_user(chunk);
2765         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2766                 reply_code = LTTNG_ERR_UNK;
2767                 ret = -1;
2768                 goto end;
2769         }
2770
2771         assert(conn->session->output_directory);
2772         chunk_status = lttng_trace_chunk_set_as_owner(chunk,
2773                         conn->session->output_directory);
2774         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2775                 reply_code = LTTNG_ERR_UNK;
2776                 ret = -1;
2777                 goto end;
2778         }
2779
2780         published_chunk = sessiond_trace_chunk_registry_publish_chunk(
2781                         sessiond_trace_chunk_registry,
2782                         conn->session->sessiond_uuid,
2783                         conn->session->id,
2784                         chunk);
2785         if (!published_chunk) {
2786                 char uuid_str[LTTNG_UUID_STR_LEN];
2787
2788                 lttng_uuid_to_str(conn->session->sessiond_uuid, uuid_str);
2789                 ERR("Failed to publish chunk: sessiond_uuid = %s, session_id = %" PRIu64 ", chunk_id = %" PRIu64,
2790                                 uuid_str,
2791                                 conn->session->id,
2792                                 msg->chunk_id);
2793                 ret = -1;
2794                 reply_code = LTTNG_ERR_NOMEM;
2795                 goto end;
2796         }
2797
2798         pthread_mutex_lock(&conn->session->lock);
2799         if (conn->session->pending_closure_trace_chunk) {
2800                 /*
2801                  * Invalid; this means a second create_trace_chunk command was
2802                  * received before a close_trace_chunk.
2803                  */
2804                 ERR("Invalid trace chunk close command received; a trace chunk is already waiting for a trace chunk close command");
2805                 reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2806                 ret = -1;
2807                 goto end_unlock_session;
2808         }
2809         conn->session->pending_closure_trace_chunk =
2810                         conn->session->current_trace_chunk;
2811         conn->session->current_trace_chunk = published_chunk;
2812         published_chunk = NULL;
2813         if (!conn->session->pending_closure_trace_chunk) {
2814                 session->ongoing_rotation = false;
2815         }
2816 end_unlock_session:
2817         pthread_mutex_unlock(&conn->session->lock);
2818 end:
2819         reply.ret_code = htobe32((uint32_t) reply_code);
2820         send_ret = conn->sock->ops->sendmsg(conn->sock,
2821                         &reply,
2822                         sizeof(struct lttcomm_relayd_generic_reply),
2823                         0);
2824         if (send_ret < (ssize_t) sizeof(reply)) {
2825                 ERR("Failed to send \"create trace chunk\" command reply (ret = %zd)",
2826                                 send_ret);
2827                 ret = -1;
2828         }
2829 end_no_reply:
2830         lttng_trace_chunk_put(chunk);
2831         lttng_trace_chunk_put(published_chunk);
2832         return ret;
2833 }
2834
2835 /*
2836  * relay_close_trace_chunk: close a trace chunk
2837  */
2838 static int relay_close_trace_chunk(const struct lttcomm_relayd_hdr *recv_hdr,
2839                 struct relay_connection *conn,
2840                 const struct lttng_buffer_view *payload)
2841 {
2842         int ret = 0, buf_ret;
2843         ssize_t send_ret;
2844         struct relay_session *session = conn->session;
2845         struct lttcomm_relayd_close_trace_chunk *msg;
2846         struct lttcomm_relayd_close_trace_chunk_reply reply = {};
2847         struct lttng_buffer_view header_view;
2848         struct lttng_trace_chunk *chunk = NULL;
2849         enum lttng_error_code reply_code = LTTNG_OK;
2850         enum lttng_trace_chunk_status chunk_status;
2851         uint64_t chunk_id;
2852         LTTNG_OPTIONAL(enum lttng_trace_chunk_command_type) close_command = {};
2853         time_t close_timestamp;
2854         char closed_trace_chunk_path[LTTNG_PATH_MAX];
2855         size_t path_length = 0;
2856         const char *chunk_name = NULL;
2857         struct lttng_dynamic_buffer reply_payload;
2858         const char *new_path;
2859
2860         lttng_dynamic_buffer_init(&reply_payload);
2861
2862         if (!session || !conn->version_check_done) {
2863                 ERR("Trying to close a trace chunk before version check");
2864                 ret = -1;
2865                 goto end_no_reply;
2866         }
2867
2868         if (session->major == 2 && session->minor < 11) {
2869                 ERR("Chunk close command is unsupported before 2.11");
2870                 ret = -1;
2871                 goto end_no_reply;
2872         }
2873
2874         header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
2875         if (!header_view.data) {
2876                 ERR("Failed to receive payload of chunk close command");
2877                 ret = -1;
2878                 goto end_no_reply;
2879         }
2880
2881         /* Convert to host endianness. */
2882         msg = (typeof(msg)) header_view.data;
2883         chunk_id = be64toh(msg->chunk_id);
2884         close_timestamp = (time_t) be64toh(msg->close_timestamp);
2885         close_command = (typeof(close_command)){
2886                 .value = be32toh(msg->close_command.value),
2887                 .is_set = msg->close_command.is_set,
2888         };
2889
2890         chunk = sessiond_trace_chunk_registry_get_chunk(
2891                         sessiond_trace_chunk_registry,
2892                         conn->session->sessiond_uuid,
2893                         conn->session->id,
2894                         chunk_id);
2895         if (!chunk) {
2896                 char uuid_str[LTTNG_UUID_STR_LEN];
2897
2898                 lttng_uuid_to_str(conn->session->sessiond_uuid, uuid_str);
2899                 ERR("Failed to find chunk to close: sessiond_uuid = %s, session_id = %" PRIu64 ", chunk_id = %" PRIu64,
2900                                 uuid_str,
2901                                 conn->session->id,
2902                                 msg->chunk_id);
2903                 ret = -1;
2904                 reply_code = LTTNG_ERR_NOMEM;
2905                 goto end;
2906         }
2907
2908         pthread_mutex_lock(&session->lock);
2909         if (close_command.is_set &&
2910                         close_command.value == LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE) {
2911                 /*
2912                  * Clear command. It is a protocol error to ask for a
2913                  * clear on a relay which does not allow it. Querying
2914                  * the configuration allows figuring out whether
2915                  * clearing is allowed before doing the clear.
2916                  */
2917                 if (!opt_allow_clear) {
2918                         ret = -1;
2919                         reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2920                         goto end_unlock_session;
2921                 }
2922         }
2923         if (session->pending_closure_trace_chunk &&
2924                         session->pending_closure_trace_chunk != chunk) {
2925                 ERR("Trace chunk close command for session \"%s\" does not target the trace chunk pending closure",
2926                                 session->session_name);
2927                 reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2928                 ret = -1;
2929                 goto end_unlock_session;
2930         }
2931
2932         if (session->current_trace_chunk && session->current_trace_chunk != chunk &&
2933                         !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
2934                 if (close_command.is_set &&
2935                                 close_command.value == LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE &&
2936                                 !session->has_rotated) {
2937                         /* New chunk stays in session output directory. */
2938                         new_path = "";
2939                 } else {
2940                         /* Use chunk name for new chunk. */
2941                         new_path = NULL;
2942                 }
2943                 /* Rename new chunk path. */
2944                 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
2945                                 new_path);
2946                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2947                         ret = -1;
2948                         goto end_unlock_session;
2949                 }
2950                 session->ongoing_rotation = false;
2951         }
2952         if ((!close_command.is_set ||
2953                         close_command.value == LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION) &&
2954                         !lttng_trace_chunk_get_name_overridden(chunk)) {
2955                 const char *old_path;
2956
2957                 if (!session->has_rotated) {
2958                         old_path = "";
2959                 } else {
2960                         old_path = NULL;
2961                 }
2962                 /* We need to move back the .tmp_old_chunk to its rightful place. */
2963                 chunk_status = lttng_trace_chunk_rename_path(chunk, old_path);
2964                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2965                         ret = -1;
2966                         goto end_unlock_session;
2967                 }
2968         }
2969         chunk_status = lttng_trace_chunk_set_close_timestamp(
2970                         chunk, close_timestamp);
2971         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2972                 ERR("Failed to set trace chunk close timestamp");
2973                 ret = -1;
2974                 reply_code = LTTNG_ERR_UNK;
2975                 goto end_unlock_session;
2976         }
2977
2978         if (close_command.is_set) {
2979                 chunk_status = lttng_trace_chunk_set_close_command(
2980                                 chunk, close_command.value);
2981                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2982                         ret = -1;
2983                         reply_code = LTTNG_ERR_INVALID;
2984                         goto end_unlock_session;
2985                 }
2986         }
2987         chunk_status = lttng_trace_chunk_get_name(chunk, &chunk_name, NULL);
2988         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2989                 ERR("Failed to get chunk name");
2990                 ret = -1;
2991                 reply_code = LTTNG_ERR_UNK;
2992                 goto end_unlock_session;
2993         }
2994         if (!session->has_rotated && !session->snapshot) {
2995                 ret = lttng_strncpy(closed_trace_chunk_path,
2996                                 session->output_path,
2997                                 sizeof(closed_trace_chunk_path));
2998                 if (ret) {
2999                         ERR("Failed to send trace chunk path: path length of %zu bytes exceeds the maximal allowed length of %zu bytes",
3000                                         strlen(session->output_path),
3001                                         sizeof(closed_trace_chunk_path));
3002                         reply_code = LTTNG_ERR_NOMEM;
3003                         ret = -1;
3004                         goto end_unlock_session;
3005                 }
3006         } else {
3007                 if (session->snapshot) {
3008                         ret = snprintf(closed_trace_chunk_path,
3009                                         sizeof(closed_trace_chunk_path),
3010                                         "%s/%s", session->output_path,
3011                                         chunk_name);
3012                 } else {
3013                         ret = snprintf(closed_trace_chunk_path,
3014                                         sizeof(closed_trace_chunk_path),
3015                                         "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY
3016                                         "/%s",
3017                                         session->output_path, chunk_name);
3018                 }
3019                 if (ret < 0 || ret == sizeof(closed_trace_chunk_path)) {
3020                         ERR("Failed to format closed trace chunk resulting path");
3021                         reply_code = ret < 0 ? LTTNG_ERR_UNK : LTTNG_ERR_NOMEM;
3022                         ret = -1;
3023                         goto end_unlock_session;
3024                 }
3025         }
3026         if (close_command.is_set &&
3027                         close_command.value == LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED) {
3028                 session->has_rotated = true;
3029         }
3030         DBG("Reply chunk path on close: %s", closed_trace_chunk_path);
3031         path_length = strlen(closed_trace_chunk_path) + 1;
3032         if (path_length > UINT32_MAX) {
3033                 ERR("Closed trace chunk path exceeds the maximal length allowed by the protocol");
3034                 ret = -1;
3035                 reply_code = LTTNG_ERR_INVALID_PROTOCOL;
3036                 goto end_unlock_session;
3037         }
3038
3039         if (session->current_trace_chunk == chunk) {
3040                 /*
3041                  * After a trace chunk close command, no new streams
3042                  * referencing the chunk may be created. Hence, on the
3043                  * event that no new trace chunk have been created for
3044                  * the session, the reference to the current trace chunk
3045                  * is released in order to allow it to be reclaimed when
3046                  * the last stream releases its reference to it.
3047                  */
3048                 lttng_trace_chunk_put(session->current_trace_chunk);
3049                 session->current_trace_chunk = NULL;
3050         }
3051         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
3052         session->pending_closure_trace_chunk = NULL;
3053 end_unlock_session:
3054         pthread_mutex_unlock(&session->lock);
3055
3056 end:
3057         reply.generic.ret_code = htobe32((uint32_t) reply_code);
3058         reply.path_length = htobe32((uint32_t) path_length);
3059         buf_ret = lttng_dynamic_buffer_append(
3060                         &reply_payload, &reply, sizeof(reply));
3061         if (buf_ret) {
3062                 ERR("Failed to append \"close trace chunk\" command reply header to payload buffer");
3063                 goto end_no_reply;
3064         }
3065
3066         if (reply_code == LTTNG_OK) {
3067                 buf_ret = lttng_dynamic_buffer_append(&reply_payload,
3068                                 closed_trace_chunk_path, path_length);
3069                 if (buf_ret) {
3070                         ERR("Failed to append \"close trace chunk\" command reply path to payload buffer");
3071                         goto end_no_reply;
3072                 }
3073         }
3074
3075         send_ret = conn->sock->ops->sendmsg(conn->sock,
3076                         reply_payload.data,
3077                         reply_payload.size,
3078                         0);
3079         if (send_ret < reply_payload.size) {
3080                 ERR("Failed to send \"close trace chunk\" command reply of %zu bytes (ret = %zd)",
3081                                 reply_payload.size, send_ret);
3082                 ret = -1;
3083                 goto end_no_reply;
3084         }
3085 end_no_reply:
3086         lttng_trace_chunk_put(chunk);
3087         lttng_dynamic_buffer_reset(&reply_payload);
3088         return ret;
3089 }
3090
3091 /*
3092  * relay_trace_chunk_exists: check if a trace chunk exists
3093  */
3094 static int relay_trace_chunk_exists(const struct lttcomm_relayd_hdr *recv_hdr,
3095                 struct relay_connection *conn,
3096                 const struct lttng_buffer_view *payload)
3097 {
3098         int ret = 0;
3099         ssize_t send_ret;
3100         struct relay_session *session = conn->session;
3101         struct lttcomm_relayd_trace_chunk_exists *msg;
3102         struct lttcomm_relayd_trace_chunk_exists_reply reply = {};
3103         struct lttng_buffer_view header_view;
3104         uint64_t chunk_id;
3105         bool chunk_exists;
3106
3107         if (!session || !conn->version_check_done) {
3108                 ERR("Trying to close a trace chunk before version check");
3109                 ret = -1;
3110                 goto end_no_reply;
3111         }
3112
3113         if (session->major == 2 && session->minor < 11) {
3114                 ERR("Chunk close command is unsupported before 2.11");
3115                 ret = -1;
3116                 goto end_no_reply;
3117         }
3118
3119         header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
3120         if (!header_view.data) {
3121                 ERR("Failed to receive payload of chunk close command");
3122                 ret = -1;
3123                 goto end_no_reply;
3124         }
3125
3126         /* Convert to host endianness. */
3127         msg = (typeof(msg)) header_view.data;
3128         chunk_id = be64toh(msg->chunk_id);
3129
3130         ret = sessiond_trace_chunk_registry_chunk_exists(
3131                         sessiond_trace_chunk_registry,
3132                         conn->session->sessiond_uuid,
3133                         conn->session->id,
3134                         chunk_id, &chunk_exists);
3135         /*
3136          * If ret is not 0, send the reply and report the error to the caller.
3137          * It is a protocol (or internal) error and the session/connection
3138          * should be torn down.
3139          */
3140         reply = (typeof(reply)){
3141                 .generic.ret_code = htobe32((uint32_t)
3142                         (ret == 0 ? LTTNG_OK : LTTNG_ERR_INVALID_PROTOCOL)),
3143                 .trace_chunk_exists = ret == 0 ? chunk_exists : 0,
3144         };
3145         send_ret = conn->sock->ops->sendmsg(
3146                         conn->sock, &reply, sizeof(reply), 0);
3147         if (send_ret < (ssize_t) sizeof(reply)) {
3148                 ERR("Failed to send \"create trace chunk\" command reply (ret = %zd)",
3149                                 send_ret);
3150                 ret = -1;
3151         }
3152 end_no_reply:
3153         return ret;
3154 }
3155
3156 /*
3157  * relay_get_configuration: query whether feature is available
3158  */
3159 static int relay_get_configuration(const struct lttcomm_relayd_hdr *recv_hdr,
3160                 struct relay_connection *conn,
3161                 const struct lttng_buffer_view *payload)
3162 {
3163         int ret = 0;
3164         ssize_t send_ret;
3165         struct lttcomm_relayd_get_configuration *msg;
3166         struct lttcomm_relayd_get_configuration_reply reply = {};
3167         struct lttng_buffer_view header_view;
3168         uint64_t query_flags = 0;
3169         uint64_t result_flags = 0;
3170
3171         header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
3172         if (!header_view.data) {
3173                 ERR("Failed to receive payload of chunk close command");
3174                 ret = -1;
3175                 goto end_no_reply;
3176         }
3177
3178         /* Convert to host endianness. */
3179         msg = (typeof(msg)) header_view.data;
3180         query_flags = be64toh(msg->query_flags);
3181
3182         if (query_flags) {
3183                 ret = LTTNG_ERR_INVALID_PROTOCOL;
3184                 goto reply;
3185         }
3186         if (opt_allow_clear) {
3187                 result_flags |= LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED;
3188         }
3189         ret = 0;
3190 reply:
3191         reply = (typeof(reply)){
3192                 .generic.ret_code = htobe32((uint32_t)
3193                         (ret == 0 ? LTTNG_OK : LTTNG_ERR_INVALID_PROTOCOL)),
3194                 .relayd_configuration_flags = htobe64(result_flags),
3195         };
3196         send_ret = conn->sock->ops->sendmsg(
3197                         conn->sock, &reply, sizeof(reply), 0);
3198         if (send_ret < (ssize_t) sizeof(reply)) {
3199                 ERR("Failed to send \"get configuration\" command reply (ret = %zd)",
3200                                 send_ret);
3201                 ret = -1;
3202         }
3203 end_no_reply:
3204         return ret;
3205 }
3206
3207 #define DBG_CMD(cmd_name, conn) \
3208                 DBG3("Processing \"%s\" command for socket %i", cmd_name, conn->sock->fd);
3209
3210 static int relay_process_control_command(struct relay_connection *conn,
3211                 const struct lttcomm_relayd_hdr *header,
3212                 const struct lttng_buffer_view *payload)
3213 {
3214         int ret = 0;
3215
3216         switch (header->cmd) {
3217         case RELAYD_CREATE_SESSION:
3218                 DBG_CMD("RELAYD_CREATE_SESSION", conn);
3219                 ret = relay_create_session(header, conn, payload);
3220                 break;
3221         case RELAYD_ADD_STREAM:
3222                 DBG_CMD("RELAYD_ADD_STREAM", conn);
3223                 ret = relay_add_stream(header, conn, payload);
3224                 break;
3225         case RELAYD_START_DATA:
3226                 DBG_CMD("RELAYD_START_DATA", conn);
3227                 ret = relay_start(header, conn, payload);
3228                 break;
3229         case RELAYD_SEND_METADATA:
3230                 DBG_CMD("RELAYD_SEND_METADATA", conn);
3231                 ret = relay_recv_metadata(header, conn, payload);
3232                 break;
3233         case RELAYD_VERSION:
3234                 DBG_CMD("RELAYD_VERSION", conn);
3235                 ret = relay_send_version(header, conn, payload);
3236                 break;
3237         case RELAYD_CLOSE_STREAM:
3238                 DBG_CMD("RELAYD_CLOSE_STREAM", conn);
3239                 ret = relay_close_stream(header, conn, payload);
3240                 break;
3241         case RELAYD_DATA_PENDING:
3242                 DBG_CMD("RELAYD_DATA_PENDING", conn);
3243                 ret = relay_data_pending(header, conn, payload);
3244                 break;
3245         case RELAYD_QUIESCENT_CONTROL:
3246                 DBG_CMD("RELAYD_QUIESCENT_CONTROL", conn);
3247                 ret = relay_quiescent_control(header, conn, payload);
3248                 break;
3249         case RELAYD_BEGIN_DATA_PENDING:
3250                 DBG_CMD("RELAYD_BEGIN_DATA_PENDING", conn);
3251                 ret = relay_begin_data_pending(header, conn, payload);
3252                 break;
3253         case RELAYD_END_DATA_PENDING:
3254                 DBG_CMD("RELAYD_END_DATA_PENDING", conn);
3255                 ret = relay_end_data_pending(header, conn, payload);
3256                 break;
3257         case RELAYD_SEND_INDEX:
3258                 DBG_CMD("RELAYD_SEND_INDEX", conn);
3259                 ret = relay_recv_index(header, conn, payload);
3260                 break;
3261         case RELAYD_STREAMS_SENT:
3262                 DBG_CMD("RELAYD_STREAMS_SENT", conn);
3263                 ret = relay_streams_sent(header, conn, payload);
3264                 break;
3265         case RELAYD_RESET_METADATA:
3266                 DBG_CMD("RELAYD_RESET_METADATA", conn);
3267                 ret = relay_reset_metadata(header, conn, payload);
3268                 break;
3269         case RELAYD_ROTATE_STREAMS:
3270                 DBG_CMD("RELAYD_ROTATE_STREAMS", conn);
3271                 ret = relay_rotate_session_streams(header, conn, payload);
3272                 break;
3273         case RELAYD_CREATE_TRACE_CHUNK:
3274                 DBG_CMD("RELAYD_CREATE_TRACE_CHUNK", conn);
3275                 ret = relay_create_trace_chunk(header, conn, payload);
3276                 break;
3277         case RELAYD_CLOSE_TRACE_CHUNK:
3278                 DBG_CMD("RELAYD_CLOSE_TRACE_CHUNK", conn);
3279                 ret = relay_close_trace_chunk(header, conn, payload);
3280                 break;
3281         case RELAYD_TRACE_CHUNK_EXISTS:
3282                 DBG_CMD("RELAYD_TRACE_CHUNK_EXISTS", conn);
3283                 ret = relay_trace_chunk_exists(header, conn, payload);
3284                 break;
3285         case RELAYD_GET_CONFIGURATION:
3286                 DBG_CMD("RELAYD_GET_CONFIGURATION", conn);
3287                 ret = relay_get_configuration(header, conn, payload);
3288                 break;
3289         case RELAYD_UPDATE_SYNC_INFO:
3290         default:
3291                 ERR("Received unknown command (%u)", header->cmd);
3292                 relay_unknown_command(conn);
3293                 ret = -1;
3294                 goto end;
3295         }
3296
3297 end:
3298         return ret;
3299 }
3300
3301 static enum relay_connection_status relay_process_control_receive_payload(
3302                 struct relay_connection *conn)
3303 {
3304         int ret = 0;
3305         enum relay_connection_status status = RELAY_CONNECTION_STATUS_OK;
3306         struct lttng_dynamic_buffer *reception_buffer =
3307                         &conn->protocol.ctrl.reception_buffer;
3308         struct ctrl_connection_state_receive_payload *state =
3309                         &conn->protocol.ctrl.state.receive_payload;
3310         struct lttng_buffer_view payload_view;
3311
3312         if (state->left_to_receive == 0) {
3313                 /* Short-circuit for payload-less commands. */
3314                 goto reception_complete;
3315         }
3316
3317         ret = conn->sock->ops->recvmsg(conn->sock,
3318                         reception_buffer->data + state->received,
3319                         state->left_to_receive, MSG_DONTWAIT);
3320         if (ret < 0) {
3321                 if (errno != EAGAIN && errno != EWOULDBLOCK) {
3322                         PERROR("Unable to receive command payload on sock %d",
3323                                         conn->sock->fd);
3324                         status = RELAY_CONNECTION_STATUS_ERROR;
3325                 }
3326                 goto end;
3327         } else if (ret == 0) {
3328                 DBG("Socket %d performed an orderly shutdown (received EOF)", conn->sock->fd);
3329                 status = RELAY_CONNECTION_STATUS_CLOSED;
3330                 goto end;
3331         }
3332
3333         assert(ret > 0);
3334         assert(ret <= state->left_to_receive);
3335
3336         state->left_to_receive -= ret;
3337         state->received += ret;
3338
3339         if (state->left_to_receive > 0) {
3340                 /*
3341                  * Can't transition to the protocol's next state, wait to
3342                  * receive the rest of the header.
3343                  */
3344                 DBG3("Partial reception of control connection protocol payload (received %" PRIu64 " bytes, %" PRIu64 " bytes left to receive, fd = %i)",
3345                                 state->received, state->left_to_receive,
3346                                 conn->sock->fd);
3347                 goto end;
3348         }
3349
3350 reception_complete:
3351         DBG("Done receiving control command payload: fd = %i, payload size = %" PRIu64 " bytes",
3352                         conn->sock->fd, state->received);
3353         /*
3354          * The payload required to process the command has been received.
3355          * A view to the reception buffer is forwarded to the various
3356          * commands and the state of the control is reset on success.
3357          *
3358          * Commands are responsible for sending their reply to the peer.
3359          */
3360         payload_view = lttng_buffer_view_from_dynamic_buffer(reception_buffer,
3361                         0, -1);
3362         ret = relay_process_control_command(conn,
3363                         &state->header, &payload_view);
3364         if (ret < 0) {
3365                 status = RELAY_CONNECTION_STATUS_ERROR;
3366                 goto end;
3367         }
3368
3369         ret = connection_reset_protocol_state(conn);
3370         if (ret) {
3371                 status = RELAY_CONNECTION_STATUS_ERROR;
3372         }
3373 end:
3374         return status;
3375 }
3376
3377 static enum relay_connection_status relay_process_control_receive_header(
3378                 struct relay_connection *conn)
3379 {
3380         int ret = 0;
3381         enum relay_connection_status status = RELAY_CONNECTION_STATUS_OK;
3382         struct lttcomm_relayd_hdr header;
3383         struct lttng_dynamic_buffer *reception_buffer =
3384                         &conn->protocol.ctrl.reception_buffer;
3385         struct ctrl_connection_state_receive_header *state =
3386                         &conn->protocol.ctrl.state.receive_header;
3387
3388         assert(state->left_to_receive != 0);
3389
3390         ret = conn->sock->ops->recvmsg(conn->sock,
3391                         reception_buffer->data + state->received,
3392                         state->left_to_receive, MSG_DONTWAIT);
3393         if (ret < 0) {
3394                 if (errno != EAGAIN && errno != EWOULDBLOCK) {
3395                         PERROR("Unable to receive control command header on sock %d",
3396                                         conn->sock->fd);
3397                         status = RELAY_CONNECTION_STATUS_ERROR;
3398                 }
3399                 goto end;
3400         } else if (ret == 0) {
3401                 DBG("Socket %d performed an orderly shutdown (received EOF)", conn->sock->fd);
3402                 status = RELAY_CONNECTION_STATUS_CLOSED;
3403                 goto end;
3404         }
3405
3406         assert(ret > 0);
3407         assert(ret <= state->left_to_receive);
3408
3409         state->left_to_receive -= ret;
3410         state->received += ret;
3411
3412         if (state->left_to_receive > 0) {
3413                 /*
3414                  * Can't transition to the protocol's next state, wait to
3415                  * receive the rest of the header.
3416                  */
3417                 DBG3("Partial reception of control connection protocol header (received %" PRIu64 " bytes, %" PRIu64 " bytes left to receive, fd = %i)",
3418                                 state->received, state->left_to_receive,
3419                                 conn->sock->fd);
3420                 goto end;
3421         }
3422
3423         /* Transition to next state: receiving the command's payload. */
3424         conn->protocol.ctrl.state_id =
3425                         CTRL_CONNECTION_STATE_RECEIVE_PAYLOAD;
3426         memcpy(&header, reception_buffer->data, sizeof(header));
3427         header.circuit_id = be64toh(header.circuit_id);
3428         header.data_size = be64toh(header.data_size);
3429         header.cmd = be32toh(header.cmd);
3430         header.cmd_version = be32toh(header.cmd_version);
3431         memcpy(&conn->protocol.ctrl.state.receive_payload.header,
3432                         &header, sizeof(header));
3433
3434         DBG("Done receiving control command header: fd = %i, cmd = %" PRIu32 ", cmd_version = %" PRIu32 ", payload size = %" PRIu64 " bytes",
3435                         conn->sock->fd, header.cmd, header.cmd_version,
3436                         header.data_size);
3437
3438         if (header.data_size > DEFAULT_NETWORK_RELAYD_CTRL_MAX_PAYLOAD_SIZE) {
3439                 ERR("Command header indicates a payload (%" PRIu64 " bytes) that exceeds the maximal payload size allowed on a control connection.",
3440                                 header.data_size);
3441                 status = RELAY_CONNECTION_STATUS_ERROR;
3442                 goto end;
3443         }
3444
3445         conn->protocol.ctrl.state.receive_payload.left_to_receive =
3446                         header.data_size;
3447         conn->protocol.ctrl.state.receive_payload.received = 0;
3448         ret = lttng_dynamic_buffer_set_size(reception_buffer,
3449                         header.data_size);
3450         if (ret) {
3451                 status = RELAY_CONNECTION_STATUS_ERROR;
3452                 goto end;
3453         }
3454
3455         if (header.data_size == 0) {
3456                 /*
3457                  * Manually invoke the next state as the poll loop
3458                  * will not wake-up to allow us to proceed further.
3459                  */
3460                 status = relay_process_control_receive_payload(conn);
3461         }
3462 end:
3463         return status;
3464 }
3465
3466 /*
3467  * Process the commands received on the control socket
3468  */
3469 static enum relay_connection_status relay_process_control(
3470                 struct relay_connection *conn)
3471 {
3472         enum relay_connection_status status;
3473
3474         switch (conn->protocol.ctrl.state_id) {
3475         case CTRL_CONNECTION_STATE_RECEIVE_HEADER:
3476                 status = relay_process_control_receive_header(conn);
3477                 break;
3478         case CTRL_CONNECTION_STATE_RECEIVE_PAYLOAD:
3479                 status = relay_process_control_receive_payload(conn);
3480                 break;
3481         default:
3482                 ERR("Unknown control connection protocol state encountered.");
3483                 abort();
3484         }
3485
3486         return status;
3487 }
3488
3489 static enum relay_connection_status relay_process_data_receive_header(
3490                 struct relay_connection *conn)
3491 {
3492         int ret;
3493         enum relay_connection_status status = RELAY_CONNECTION_STATUS_OK;
3494         struct data_connection_state_receive_header *state =
3495                         &conn->protocol.data.state.receive_header;
3496         struct lttcomm_relayd_data_hdr header;
3497         struct relay_stream *stream;
3498
3499         assert(state->left_to_receive != 0);
3500
3501         ret = conn->sock->ops->recvmsg(conn->sock,
3502                         state->header_reception_buffer + state->received,
3503                         state->left_to_receive, MSG_DONTWAIT);
3504         if (ret < 0) {
3505                 if (errno != EAGAIN && errno != EWOULDBLOCK) {
3506                         PERROR("Unable to receive data header on sock %d", conn->sock->fd);
3507                         status = RELAY_CONNECTION_STATUS_ERROR;
3508                 }
3509                 goto end;
3510         } else if (ret == 0) {
3511                 /* Orderly shutdown. Not necessary to print an error. */
3512                 DBG("Socket %d performed an orderly shutdown (received EOF)", conn->sock->fd);
3513                 status = RELAY_CONNECTION_STATUS_CLOSED;
3514                 goto end;
3515         }
3516
3517         assert(ret > 0);
3518         assert(ret <= state->left_to_receive);
3519
3520         state->left_to_receive -= ret;
3521         state->received += ret;
3522
3523         if (state->left_to_receive > 0) {
3524                 /*
3525                  * Can't transition to the protocol's next state, wait to
3526                  * receive the rest of the header.
3527                  */
3528                 DBG3("Partial reception of data connection header (received %" PRIu64 " bytes, %" PRIu64 " bytes left to receive, fd = %i)",
3529                                 state->received, state->left_to_receive,
3530                                 conn->sock->fd);
3531                 goto end;
3532         }
3533
3534         /* Transition to next state: receiving the payload. */
3535         conn->protocol.data.state_id = DATA_CONNECTION_STATE_RECEIVE_PAYLOAD;
3536
3537         memcpy(&header, state->header_reception_buffer, sizeof(header));
3538         header.circuit_id = be64toh(header.circuit_id);
3539         header.stream_id = be64toh(header.stream_id);
3540         header.data_size = be32toh(header.data_size);
3541         header.net_seq_num = be64toh(header.net_seq_num);
3542         header.padding_size = be32toh(header.padding_size);
3543         memcpy(&conn->protocol.data.state.receive_payload.header, &header, sizeof(header));
3544
3545         conn->protocol.data.state.receive_payload.left_to_receive =
3546                         header.data_size;
3547         conn->protocol.data.state.receive_payload.received = 0;
3548         conn->protocol.data.state.receive_payload.rotate_index = false;
3549
3550         DBG("Received data connection header on fd %i: circuit_id = %" PRIu64 ", stream_id = %" PRIu64 ", data_size = %" PRIu32 ", net_seq_num = %" PRIu64 ", padding_size = %" PRIu32,
3551                         conn->sock->fd, header.circuit_id,
3552                         header.stream_id, header.data_size,
3553                         header.net_seq_num, header.padding_size);
3554
3555         stream = stream_get_by_id(header.stream_id);
3556         if (!stream) {
3557                 DBG("relay_process_data_receive_payload: Cannot find stream %" PRIu64,
3558                                 header.stream_id);
3559                 /* Protocol error. */
3560                 status = RELAY_CONNECTION_STATUS_ERROR;
3561                 goto end;
3562         }
3563
3564         pthread_mutex_lock(&stream->lock);
3565         /* Prepare stream for the reception of a new packet. */
3566         ret = stream_init_packet(stream, header.data_size,
3567                         &conn->protocol.data.state.receive_payload.rotate_index);
3568         pthread_mutex_unlock(&stream->lock);
3569         if (ret) {
3570                 ERR("Failed to rotate stream output file");
3571                 status = RELAY_CONNECTION_STATUS_ERROR;
3572                 goto end_stream_unlock;
3573         }
3574
3575 end_stream_unlock:
3576         stream_put(stream);
3577 end:
3578         return status;
3579 }
3580
3581 static enum relay_connection_status relay_process_data_receive_payload(
3582                 struct relay_connection *conn)
3583 {
3584         int ret;
3585         enum relay_connection_status status = RELAY_CONNECTION_STATUS_OK;
3586         struct relay_stream *stream;
3587         struct data_connection_state_receive_payload *state =
3588                         &conn->protocol.data.state.receive_payload;
3589         const size_t chunk_size = RECV_DATA_BUFFER_SIZE;
3590         char data_buffer[chunk_size];
3591         bool partial_recv = false;
3592         bool new_stream = false, close_requested = false, index_flushed = false;
3593         uint64_t left_to_receive = state->left_to_receive;
3594         struct relay_session *session;
3595
3596         DBG3("Receiving data for stream id %" PRIu64 " seqnum %" PRIu64 ", %" PRIu64" bytes received, %" PRIu64 " bytes left to receive",
3597                         state->header.stream_id, state->header.net_seq_num,
3598                         state->received, left_to_receive);
3599
3600         stream = stream_get_by_id(state->header.stream_id);
3601         if (!stream) {
3602                 /* Protocol error. */
3603                 ERR("relay_process_data_receive_payload: cannot find stream %" PRIu64,
3604                                 state->header.stream_id);
3605                 status = RELAY_CONNECTION_STATUS_ERROR;
3606                 goto end;
3607         }
3608
3609         pthread_mutex_lock(&stream->lock);
3610         session = stream->trace->session;
3611         if (!conn->session) {
3612                 ret = connection_set_session(conn, session);
3613                 if (ret) {
3614                         status = RELAY_CONNECTION_STATUS_ERROR;
3615                         goto end_stream_unlock;
3616                 }
3617         }
3618
3619         /*
3620          * The size of the "chunk" received on any iteration is bounded by:
3621          *   - the data left to receive,
3622          *   - the data immediately available on the socket,
3623          *   - the on-stack data buffer
3624          */
3625         while (left_to_receive > 0 && !partial_recv) {
3626                 size_t recv_size = min(left_to_receive, chunk_size);
3627                 struct lttng_buffer_view packet_chunk;
3628
3629                 ret = conn->sock->ops->recvmsg(conn->sock, data_buffer,
3630                                 recv_size, MSG_DONTWAIT);
3631                 if (ret < 0) {
3632                         if (errno != EAGAIN && errno != EWOULDBLOCK) {
3633                                 PERROR("Socket %d error", conn->sock->fd);
3634                                 status = RELAY_CONNECTION_STATUS_ERROR;
3635                         }
3636                         goto end_stream_unlock;
3637                 } else if (ret == 0) {
3638                         /* No more data ready to be consumed on socket. */
3639                         DBG3("No more data ready for consumption on data socket of stream id %" PRIu64,
3640                                         state->header.stream_id);
3641                         status = RELAY_CONNECTION_STATUS_CLOSED;
3642                         break;
3643                 } else if (ret < (int) recv_size) {
3644                         /*
3645                          * All the data available on the socket has been
3646                          * consumed.
3647                          */
3648                         partial_recv = true;
3649                         recv_size = ret;
3650                 }
3651
3652                 packet_chunk = lttng_buffer_view_init(data_buffer,
3653                                 0, recv_size);
3654                 assert(packet_chunk.data);
3655
3656                 ret = stream_write(stream, &packet_chunk, 0);
3657                 if (ret) {
3658                         ERR("Relay error writing data to file");
3659                         status = RELAY_CONNECTION_STATUS_ERROR;
3660                         goto end_stream_unlock;
3661                 }
3662
3663                 left_to_receive -= recv_size;
3664                 state->received += recv_size;
3665                 state->left_to_receive = left_to_receive;
3666         }
3667
3668         if (state->left_to_receive > 0) {
3669                 /*
3670                  * Did not receive all the data expected, wait for more data to
3671                  * become available on the socket.
3672                  */
3673                 DBG3("Partial receive on data connection of stream id %" PRIu64 ", %" PRIu64 " bytes received, %" PRIu64 " bytes left to receive",
3674                                 state->header.stream_id, state->received,
3675                                 state->left_to_receive);
3676                 goto end_stream_unlock;
3677         }
3678
3679         ret = stream_write(stream, NULL, state->header.padding_size);
3680         if (ret) {
3681                 status = RELAY_CONNECTION_STATUS_ERROR;
3682                 goto end_stream_unlock;
3683         }
3684
3685         if (session_streams_have_index(session)) {
3686                 ret = stream_update_index(stream, state->header.net_seq_num,
3687                                 state->rotate_index, &index_flushed,
3688                                 state->header.data_size + state->header.padding_size);
3689                 if (ret < 0) {
3690                         ERR("Failed to update index: stream %" PRIu64 " net_seq_num %" PRIu64 " ret %d",
3691                                         stream->stream_handle,
3692                                         state->header.net_seq_num, ret);
3693                         status = RELAY_CONNECTION_STATUS_ERROR;
3694                         goto end_stream_unlock;
3695                 }
3696         }
3697
3698         if (stream->prev_data_seq == -1ULL) {
3699                 new_stream = true;
3700         }
3701
3702         ret = stream_complete_packet(stream, state->header.data_size +
3703                         state->header.padding_size, state->header.net_seq_num,
3704                         index_flushed);
3705         if (ret) {
3706                 status = RELAY_CONNECTION_STATUS_ERROR;
3707                 goto end_stream_unlock;
3708         }
3709
3710         /*
3711          * Resetting the protocol state (to RECEIVE_HEADER) will trash the
3712          * contents of *state which are aliased (union) to the same location as
3713          * the new state. Don't use it beyond this point.
3714          */
3715         connection_reset_protocol_state(conn);
3716         state = NULL;
3717
3718 end_stream_unlock:
3719         close_requested = stream->close_requested;
3720         pthread_mutex_unlock(&stream->lock);
3721         if (close_requested && left_to_receive == 0) {
3722                 try_stream_close(stream);
3723         }
3724
3725         if (new_stream) {
3726                 pthread_mutex_lock(&session->lock);
3727                 uatomic_set(&session->new_streams, 1);
3728                 pthread_mutex_unlock(&session->lock);
3729         }
3730
3731         stream_put(stream);
3732 end:
3733         return status;
3734 }
3735
3736 /*
3737  * relay_process_data: Process the data received on the data socket
3738  */
3739 static enum relay_connection_status relay_process_data(
3740                 struct relay_connection *conn)
3741 {
3742         enum relay_connection_status status;
3743
3744         switch (conn->protocol.data.state_id) {
3745         case DATA_CONNECTION_STATE_RECEIVE_HEADER:
3746                 status = relay_process_data_receive_header(conn);
3747                 break;
3748         case DATA_CONNECTION_STATE_RECEIVE_PAYLOAD:
3749                 status = relay_process_data_receive_payload(conn);
3750                 break;
3751         default:
3752                 ERR("Unexpected data connection communication state.");
3753                 abort();
3754         }
3755
3756         return status;
3757 }
3758
3759 static void cleanup_connection_pollfd(struct lttng_poll_event *events, int pollfd)
3760 {
3761         int ret;
3762
3763         (void) lttng_poll_del(events, pollfd);
3764
3765         ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker, &pollfd, 1,
3766                         fd_tracker_util_close_fd, NULL);
3767         if (ret < 0) {
3768                 ERR("Closing pollfd %d", pollfd);
3769         }
3770 }
3771
3772 static void relay_thread_close_connection(struct lttng_poll_event *events,
3773                 int pollfd, struct relay_connection *conn)
3774 {
3775         const char *type_str;
3776
3777         switch (conn->type) {
3778         case RELAY_DATA:
3779                 type_str = "Data";
3780                 break;
3781         case RELAY_CONTROL:
3782                 type_str = "Control";
3783                 break;
3784         case RELAY_VIEWER_COMMAND:
3785                 type_str = "Viewer Command";
3786                 break;
3787         case RELAY_VIEWER_NOTIFICATION:
3788                 type_str = "Viewer Notification";
3789                 break;
3790         default:
3791                 type_str = "Unknown";
3792         }
3793         cleanup_connection_pollfd(events, pollfd);
3794         connection_put(conn);
3795         DBG("%s connection closed with %d", type_str, pollfd);
3796 }
3797
3798 /*
3799  * This thread does the actual work
3800  */
3801 static void *relay_thread_worker(void *data)
3802 {
3803         int ret, err = -1, last_seen_data_fd = -1;
3804         uint32_t nb_fd;
3805         struct lttng_poll_event events;
3806         struct lttng_ht *relay_connections_ht;
3807         struct lttng_ht_iter iter;
3808         struct relay_connection *destroy_conn = NULL;
3809
3810         DBG("[thread] Relay worker started");
3811
3812         rcu_register_thread();
3813
3814         health_register(health_relayd, HEALTH_RELAYD_TYPE_WORKER);
3815
3816         if (testpoint(relayd_thread_worker)) {
3817                 goto error_testpoint;
3818         }
3819
3820         health_code_update();
3821
3822         /* table of connections indexed on socket */
3823         relay_connections_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3824         if (!relay_connections_ht) {
3825                 goto relay_connections_ht_error;
3826         }
3827
3828         ret = create_named_thread_poll_set(&events, 2, "Worker thread epoll");
3829         if (ret < 0) {
3830                 goto error_poll_create;
3831         }
3832
3833         ret = lttng_poll_add(&events, relay_conn_pipe[0], LPOLLIN | LPOLLRDHUP);
3834         if (ret < 0) {
3835                 goto error;
3836         }
3837
3838 restart:
3839         while (1) {
3840                 int idx = -1, i, seen_control = 0, last_notdel_data_fd = -1;
3841
3842                 health_code_update();
3843
3844                 /* Infinite blocking call, waiting for transmission */
3845                 DBG3("Relayd worker thread polling...");
3846                 health_poll_entry();
3847                 ret = lttng_poll_wait(&events, -1);
3848                 health_poll_exit();
3849                 if (ret < 0) {
3850                         /*
3851                          * Restart interrupted system call.
3852                          */
3853                         if (errno == EINTR) {
3854                                 goto restart;
3855                         }
3856                         goto error;
3857                 }
3858
3859                 nb_fd = ret;
3860
3861                 /*
3862                  * Process control. The control connection is
3863                  * prioritized so we don't starve it with high
3864                  * throughput tracing data on the data connection.
3865                  */
3866                 for (i = 0; i < nb_fd; i++) {
3867                         /* Fetch once the poll data */
3868                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
3869                         int pollfd = LTTNG_POLL_GETFD(&events, i);
3870
3871                         health_code_update();
3872
3873                         /* Thread quit pipe has been closed. Killing thread. */
3874                         ret = check_thread_quit_pipe(pollfd, revents);
3875                         if (ret) {
3876                                 err = 0;
3877                                 goto exit;
3878                         }
3879
3880                         /* Inspect the relay conn pipe for new connection */
3881                         if (pollfd == relay_conn_pipe[0]) {
3882                                 if (revents & LPOLLIN) {
3883                                         struct relay_connection *conn;
3884
3885                                         ret = lttng_read(relay_conn_pipe[0], &conn, sizeof(conn));
3886                                         if (ret < 0) {
3887                                                 goto error;
3888                                         }
3889                                         ret = lttng_poll_add(&events,
3890                                                         conn->sock->fd,
3891                                                         LPOLLIN | LPOLLRDHUP);
3892                                         if (ret) {
3893                                                 ERR("Failed to add new connection file descriptor to poll set");
3894                                                 goto error;
3895                                         }
3896                                         connection_ht_add(relay_connections_ht, conn);
3897                                         DBG("Connection socket %d added", conn->sock->fd);
3898                                 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3899                                         ERR("Relay connection pipe error");
3900                                         goto error;
3901                                 } else {
3902                                         ERR("Unexpected poll events %u for sock %d", revents, pollfd);
3903                                         goto error;
3904                                 }
3905                         } else {
3906                                 struct relay_connection *ctrl_conn;
3907
3908                                 ctrl_conn = connection_get_by_sock(relay_connections_ht, pollfd);
3909                                 /* If not found, there is a synchronization issue. */
3910                                 assert(ctrl_conn);
3911
3912                                 if (ctrl_conn->type == RELAY_DATA) {
3913                                         if (revents & LPOLLIN) {
3914                                                 /*
3915                                                  * Flag the last seen data fd not deleted. It will be
3916                                                  * used as the last seen fd if any fd gets deleted in
3917                                                  * this first loop.
3918                                                  */
3919                                                 last_notdel_data_fd = pollfd;
3920                                         }
3921                                         goto put_ctrl_connection;
3922                                 }
3923                                 assert(ctrl_conn->type == RELAY_CONTROL);
3924
3925                                 if (revents & LPOLLIN) {
3926                                         enum relay_connection_status status;
3927
3928                                         status = relay_process_control(ctrl_conn);
3929                                         if (status != RELAY_CONNECTION_STATUS_OK) {
3930                                                 /*
3931                                                  * On socket error flag the session as aborted to force
3932                                                  * the cleanup of its stream otherwise it can leak
3933                                                  * during the lifetime of the relayd.
3934                                                  *
3935                                                  * This prevents situations in which streams can be
3936                                                  * left opened because an index was received, the
3937                                                  * control connection is closed, and the data
3938                                                  * connection is closed (uncleanly) before the packet's
3939                                                  * data provided.
3940                                                  *
3941                                                  * Since the control connection encountered an error,
3942                                                  * it is okay to be conservative and close the
3943                                                  * session right now as we can't rely on the protocol
3944                                                  * being respected anymore.
3945                                                  */
3946                                                 if (status == RELAY_CONNECTION_STATUS_ERROR) {
3947                                                         session_abort(ctrl_conn->session);
3948                                                 }
3949
3950                                                 /* Clear the connection on error or close. */
3951                                                 relay_thread_close_connection(&events,
3952                                                                 pollfd,
3953                                                                 ctrl_conn);
3954                                         }
3955                                         seen_control = 1;
3956                                 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3957                                         relay_thread_close_connection(&events,
3958                                                         pollfd, ctrl_conn);
3959                                         if (last_seen_data_fd == pollfd) {
3960                                                 last_seen_data_fd = last_notdel_data_fd;
3961                                         }
3962                                 } else {
3963                                         ERR("Unexpected poll events %u for control sock %d",
3964                                                         revents, pollfd);
3965                                         connection_put(ctrl_conn);
3966                                         goto error;
3967                                 }
3968                         put_ctrl_connection:
3969                                 connection_put(ctrl_conn);
3970                         }
3971                 }
3972
3973                 /*
3974                  * The last loop handled a control request, go back to poll to make
3975                  * sure we prioritise the control socket.
3976                  */
3977                 if (seen_control) {
3978                         continue;
3979                 }
3980
3981                 if (last_seen_data_fd >= 0) {
3982                         for (i = 0; i < nb_fd; i++) {
3983                                 int pollfd = LTTNG_POLL_GETFD(&events, i);
3984
3985                                 health_code_update();
3986
3987                                 if (last_seen_data_fd == pollfd) {
3988                                         idx = i;
3989                                         break;
3990                                 }
3991                         }
3992                 }
3993
3994                 /* Process data connection. */
3995                 for (i = idx + 1; i < nb_fd; i++) {
3996                         /* Fetch the poll data. */
3997                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
3998                         int pollfd = LTTNG_POLL_GETFD(&events, i);
3999                         struct relay_connection *data_conn;
4000
4001                         health_code_update();
4002
4003                         if (!revents) {
4004                                 /* No activity for this FD (poll implementation). */
4005                                 continue;
4006                         }
4007
4008                         /* Skip the command pipe. It's handled in the first loop. */
4009                         if (pollfd == relay_conn_pipe[0]) {
4010                                 continue;
4011                         }
4012
4013                         data_conn = connection_get_by_sock(relay_connections_ht, pollfd);
4014                         if (!data_conn) {
4015                                 /* Skip it. Might be removed before. */
4016                                 continue;
4017                         }
4018                         if (data_conn->type == RELAY_CONTROL) {
4019                                 goto put_data_connection;
4020                         }
4021                         assert(data_conn->type == RELAY_DATA);
4022
4023                         if (revents & LPOLLIN) {
4024                                 enum relay_connection_status status;
4025
4026                                 status = relay_process_data(data_conn);
4027                                 /* Connection closed or error. */
4028                                 if (status != RELAY_CONNECTION_STATUS_OK) {
4029                                         /*
4030                                          * On socket error flag the session as aborted to force
4031                                          * the cleanup of its stream otherwise it can leak
4032                                          * during the lifetime of the relayd.
4033                                          *
4034                                          * This prevents situations in which streams can be
4035                                          * left opened because an index was received, the
4036                                          * control connection is closed, and the data
4037                                          * connection is closed (uncleanly) before the packet's
4038                                          * data provided.
4039                                          *
4040                                          * Since the data connection encountered an error,
4041                                          * it is okay to be conservative and close the
4042                                          * session right now as we can't rely on the protocol
4043                                          * being respected anymore.
4044                                          */
4045                                         if (status == RELAY_CONNECTION_STATUS_ERROR) {
4046                                                 session_abort(data_conn->session);
4047                                         }
4048                                         relay_thread_close_connection(&events, pollfd,
4049                                                         data_conn);
4050                                         /*
4051                                          * Every goto restart call sets the last seen fd where
4052                                          * here we don't really care since we gracefully
4053                                          * continue the loop after the connection is deleted.
4054                                          */
4055                                 } else {
4056                                         /* Keep last seen port. */
4057                                         last_seen_data_fd = pollfd;
4058                                         connection_put(data_conn);
4059                                         goto restart;
4060                                 }
4061                         } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
4062                                 relay_thread_close_connection(&events, pollfd,
4063                                                 data_conn);
4064                         } else {
4065                                 ERR("Unknown poll events %u for data sock %d",
4066                                                 revents, pollfd);
4067                         }
4068                 put_data_connection:
4069                         connection_put(data_conn);
4070                 }
4071                 last_seen_data_fd = -1;
4072         }
4073
4074         /* Normal exit, no error */
4075         ret = 0;
4076
4077 exit:
4078 error:
4079         /* Cleanup remaining connection object. */
4080         rcu_read_lock();
4081         cds_lfht_for_each_entry(relay_connections_ht->ht, &iter.iter,
4082                         destroy_conn,
4083                         sock_n.node) {
4084                 health_code_update();
4085
4086                 session_abort(destroy_conn->session);
4087
4088                 /*
4089                  * No need to grab another ref, because we own
4090                  * destroy_conn.
4091                  */
4092                 relay_thread_close_connection(&events, destroy_conn->sock->fd,
4093                                 destroy_conn);
4094         }
4095         rcu_read_unlock();
4096
4097         (void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
4098 error_poll_create:
4099         lttng_ht_destroy(relay_connections_ht);
4100 relay_connections_ht_error:
4101         /* Close relay conn pipes */
4102         (void) fd_tracker_util_pipe_close(the_fd_tracker,
4103                         relay_conn_pipe);
4104         if (err) {
4105                 DBG("Thread exited with error");
4106         }
4107         DBG("Worker thread cleanup complete");
4108 error_testpoint:
4109         if (err) {
4110                 health_error();
4111                 ERR("Health error occurred in %s", __func__);
4112         }
4113         health_unregister(health_relayd);
4114         rcu_unregister_thread();
4115         lttng_relay_stop_threads();
4116         return NULL;
4117 }
4118
4119 /*
4120  * Create the relay command pipe to wake thread_manage_apps.
4121  * Closed in cleanup().
4122  */
4123 static int create_relay_conn_pipe(void)
4124 {
4125         return fd_tracker_util_pipe_open_cloexec(the_fd_tracker,
4126                         "Relayd connection pipe", relay_conn_pipe);
4127 }
4128
4129 static int stdio_open(void *data, int *fds)
4130 {
4131         fds[0] = fileno(stdout);
4132         fds[1] = fileno(stderr);
4133         return 0;
4134 }
4135
4136 static int track_stdio(void)
4137 {
4138         int fds[2];
4139         const char *names[] = { "stdout", "stderr" };
4140
4141         return fd_tracker_open_unsuspendable_fd(the_fd_tracker, fds,
4142                         names, 2, stdio_open, NULL);
4143 }
4144
4145 /*
4146  * main
4147  */
4148 int main(int argc, char **argv)
4149 {
4150         bool thread_is_rcu_registered = false;
4151         int ret = 0, retval = 0;
4152         void *status;
4153         char *unlinked_file_directory_path = NULL, *output_path = NULL;
4154
4155         /* Parse environment variables */
4156         ret = parse_env_options();
4157         if (ret) {
4158                 retval = -1;
4159                 goto exit_options;
4160         }
4161
4162         /*
4163          * Parse arguments.
4164          * Command line arguments overwrite environment.
4165          */
4166         progname = argv[0];
4167         if (set_options(argc, argv)) {
4168                 retval = -1;
4169                 goto exit_options;
4170         }
4171
4172         if (set_signal_handler()) {
4173                 retval = -1;
4174                 goto exit_options;
4175         }
4176
4177         relayd_config_log();
4178
4179         if (opt_print_version) {
4180                 print_version();
4181                 retval = 0;
4182                 goto exit_options;
4183         }
4184
4185         ret = fclose(stdin);
4186         if (ret) {
4187                 PERROR("Failed to close stdin");
4188                 goto exit_options;
4189         }
4190
4191         DBG("Clear command %s", opt_allow_clear ? "allowed" : "disallowed");
4192
4193         /* Try to create directory if -o, --output is specified. */
4194         if (opt_output_path) {
4195                 if (*opt_output_path != '/') {
4196                         ERR("Please specify an absolute path for -o, --output PATH");
4197                         retval = -1;
4198                         goto exit_options;
4199                 }
4200
4201                 ret = utils_mkdir_recursive(opt_output_path, S_IRWXU | S_IRWXG,
4202                                 -1, -1);
4203                 if (ret < 0) {
4204                         ERR("Unable to create %s", opt_output_path);
4205                         retval = -1;
4206                         goto exit_options;
4207                 }
4208         }
4209
4210         /* Daemonize */
4211         if (opt_daemon || opt_background) {
4212                 ret = lttng_daemonize(&child_ppid, &recv_child_signal,
4213                         !opt_background);
4214                 if (ret < 0) {
4215                         retval = -1;
4216                         goto exit_options;
4217                 }
4218         }
4219
4220         if (opt_working_directory) {
4221                 ret = utils_change_working_directory(opt_working_directory);
4222                 if (ret) {
4223                         /* All errors are already logged. */
4224                         goto exit_options;
4225                 }
4226         }
4227
4228         sessiond_trace_chunk_registry = sessiond_trace_chunk_registry_create();
4229         if (!sessiond_trace_chunk_registry) {
4230                 ERR("Failed to initialize session daemon trace chunk registry");
4231                 retval = -1;
4232                 goto exit_options;
4233         }
4234
4235         /*
4236          * The RCU thread registration (and use, through the fd-tracker's
4237          * creation) is done after the daemonization to allow us to not
4238          * deal with liburcu's fork() management as the call RCU needs to
4239          * be restored.
4240          */
4241         rcu_register_thread();
4242         thread_is_rcu_registered = true;
4243
4244         output_path = create_output_path("");
4245         if (!output_path) {
4246                 ERR("Failed to get output path");
4247                 retval = -1;
4248                 goto exit_options;
4249         }
4250         ret = asprintf(&unlinked_file_directory_path, "%s/%s", output_path,
4251                         DEFAULT_UNLINKED_FILES_DIRECTORY);
4252         free(output_path);
4253         if (ret < 0) {
4254                 ERR("Failed to format unlinked file directory path");
4255                 retval = -1;
4256                 goto exit_options;
4257         }
4258         the_fd_tracker = fd_tracker_create(
4259                         unlinked_file_directory_path, lttng_opt_fd_pool_size);
4260         free(unlinked_file_directory_path);
4261         if (!the_fd_tracker) {
4262                 retval = -1;
4263                 goto exit_options;
4264         }
4265
4266         ret = track_stdio();
4267         if (ret) {
4268                 retval = -1;
4269                 goto exit_options;
4270         }
4271
4272         /* Initialize thread health monitoring */
4273         health_relayd = health_app_create(NR_HEALTH_RELAYD_TYPES);
4274         if (!health_relayd) {
4275                 PERROR("health_app_create error");
4276                 retval = -1;
4277                 goto exit_options;
4278         }
4279
4280         /* Create thread quit pipe */
4281         if (init_thread_quit_pipe()) {
4282                 retval = -1;
4283                 goto exit_options;
4284         }
4285
4286         /* Setup the thread apps communication pipe. */
4287         if (create_relay_conn_pipe()) {
4288                 retval = -1;
4289                 goto exit_options;
4290         }
4291
4292         /* Init relay command queue. */
4293         cds_wfcq_init(&relay_conn_queue.head, &relay_conn_queue.tail);
4294
4295         /* Initialize communication library */
4296         lttcomm_init();
4297         lttcomm_inet_init();
4298
4299         /* tables of sessions indexed by session ID */
4300         sessions_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
4301         if (!sessions_ht) {
4302                 retval = -1;
4303                 goto exit_options;
4304         }
4305
4306         /* tables of streams indexed by stream ID */
4307         relay_streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
4308         if (!relay_streams_ht) {
4309                 retval = -1;
4310                 goto exit_options;
4311         }
4312
4313         /* tables of streams indexed by stream ID */
4314         viewer_streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
4315         if (!viewer_streams_ht) {
4316                 retval = -1;
4317                 goto exit_options;
4318         }
4319
4320         ret = init_health_quit_pipe();
4321         if (ret) {
4322                 retval = -1;
4323                 goto exit_options;
4324         }
4325
4326         /* Create thread to manage the client socket */
4327         ret = pthread_create(&health_thread, default_pthread_attr(),
4328                         thread_manage_health, (void *) NULL);
4329         if (ret) {
4330                 errno = ret;
4331                 PERROR("pthread_create health");
4332                 retval = -1;
4333                 goto exit_options;
4334         }
4335
4336         /* Setup the dispatcher thread */
4337         ret = pthread_create(&dispatcher_thread, default_pthread_attr(),
4338                         relay_thread_dispatcher, (void *) NULL);
4339         if (ret) {
4340                 errno = ret;
4341                 PERROR("pthread_create dispatcher");
4342                 retval = -1;
4343                 goto exit_dispatcher_thread;
4344         }
4345
4346         /* Setup the worker thread */
4347         ret = pthread_create(&worker_thread, default_pthread_attr(),
4348                         relay_thread_worker, NULL);
4349         if (ret) {
4350                 errno = ret;
4351                 PERROR("pthread_create worker");
4352                 retval = -1;
4353                 goto exit_worker_thread;
4354         }
4355
4356         /* Setup the listener thread */
4357         ret = pthread_create(&listener_thread, default_pthread_attr(),
4358                         relay_thread_listener, (void *) NULL);
4359         if (ret) {
4360                 errno = ret;
4361                 PERROR("pthread_create listener");
4362                 retval = -1;
4363                 goto exit_listener_thread;
4364         }
4365
4366         ret = relayd_live_create(live_uri);
4367         if (ret) {
4368                 ERR("Starting live viewer threads");
4369                 retval = -1;
4370                 goto exit_live;
4371         }
4372
4373         /*
4374          * This is where we start awaiting program completion (e.g. through
4375          * signal that asks threads to teardown).
4376          */
4377
4378         ret = relayd_live_join();
4379         if (ret) {
4380                 retval = -1;
4381         }
4382 exit_live:
4383
4384         ret = pthread_join(listener_thread, &status);
4385         if (ret) {
4386                 errno = ret;
4387                 PERROR("pthread_join listener_thread");
4388                 retval = -1;
4389         }
4390
4391 exit_listener_thread:
4392         ret = pthread_join(worker_thread, &status);
4393         if (ret) {
4394                 errno = ret;
4395                 PERROR("pthread_join worker_thread");
4396                 retval = -1;
4397         }
4398
4399 exit_worker_thread:
4400         ret = pthread_join(dispatcher_thread, &status);
4401         if (ret) {
4402                 errno = ret;
4403                 PERROR("pthread_join dispatcher_thread");
4404                 retval = -1;
4405         }
4406 exit_dispatcher_thread:
4407
4408         ret = pthread_join(health_thread, &status);
4409         if (ret) {
4410                 errno = ret;
4411                 PERROR("pthread_join health_thread");
4412                 retval = -1;
4413         }
4414 exit_options:
4415         /*
4416          * Wait for all pending call_rcu work to complete before tearing
4417          * down data structures. call_rcu worker may be trying to
4418          * perform lookups in those structures.
4419          */
4420         rcu_barrier();
4421         relayd_cleanup();
4422
4423         /* Ensure all prior call_rcu are done. */
4424         rcu_barrier();
4425
4426         if (thread_is_rcu_registered) {
4427                 rcu_unregister_thread();
4428         }
4429
4430         if (!retval) {
4431                 exit(EXIT_SUCCESS);
4432         } else {
4433                 exit(EXIT_FAILURE);
4434         }
4435 }