src/bin/lttng/commands/create.c

   1 /*
   2  * Copyright (C) 2011 EfficiOS Inc.
   3  * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #define _LGPL_SOURCE
  10 #include <assert.h>
  11 #include <ctype.h>
  12 #include <popt.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <sys/stat.h>
  17 #include <sys/types.h>
  18 #include <common/compat/time.h>
  19 #include <unistd.h>
  20 #include <signal.h>
  21 #include <sys/wait.h>
  22
  23 #include <common/mi-lttng.h>
  24
  25 #include "../command.h"
  26 #include "../utils.h"
  27
  28 #include <common/defaults.h>
  29 #include <common/sessiond-comm/sessiond-comm.h>
  30 #include <common/uri.h>
  31 #include <common/utils.h>
  32 #include <lttng/snapshot.h>
  33 #include <lttng/session-descriptor.h>
  34 #include <common/path.h>
  35 #include <lttng/lttng.h>
  36
  37 static char *opt_output_path;
  38 static char *opt_session_name;
  39 static char *opt_url;
  40 static char *opt_ctrl_url;
  41 static char *opt_data_url;
  42 static char *opt_shm_path;
  43 static int opt_no_consumer;
  44 static int opt_no_output;
  45 static int opt_snapshot;
  46 static uint32_t opt_live_timer;
  47
  48 #ifdef LTTNG_EMBED_HELP
  49 static const char help_msg[] =
  50 #include <lttng-create.1.h>
  51 ;
  52 #endif
  53
  54 enum {
  55         OPT_HELP = 1,
  56         OPT_LIST_OPTIONS,
  57         OPT_LIVE_TIMER,
  58 };
  59
  60 enum output_type {
  61         OUTPUT_NONE,
  62         OUTPUT_LOCAL,
  63         OUTPUT_NETWORK,
  64         OUTPUT_UNSPECIFIED,
  65 };
  66
  67 static struct mi_writer *writer;
  68 static struct poptOption long_options[] = {
  69         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  70         {"help", 'h', POPT_ARG_NONE, NULL, OPT_HELP, NULL, NULL},
  71         {"output", 'o', POPT_ARG_STRING, &opt_output_path, 0, NULL, NULL},
  72         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  73         {"set-url",        'U', POPT_ARG_STRING, &opt_url, 0, 0, 0},
  74         {"ctrl-url",       'C', POPT_ARG_STRING, &opt_ctrl_url, 0, 0, 0},
  75         {"data-url",       'D', POPT_ARG_STRING, &opt_data_url, 0, 0, 0},
  76         {"no-output",       0, POPT_ARG_VAL, &opt_no_output, 1, 0, 0},
  77         {"no-consumer",     0, POPT_ARG_VAL, &opt_no_consumer, 1, 0, 0},
  78         {"snapshot",        0, POPT_ARG_VAL, &opt_snapshot, 1, 0, 0},
  79         {"live",            0, POPT_ARG_INT | POPT_ARGFLAG_OPTIONAL, 0, OPT_LIVE_TIMER, 0, 0},
  80         {"shm-path",        0, POPT_ARG_STRING, &opt_shm_path, 0, 0, 0},
  81         {0, 0, 0, 0, 0, 0, 0}
  82 };
  83
  84 /*
  85  * Retrieve the created session and mi output it based on provided argument
  86  * This is currently a summary of what was pretty printed and is subject to
  87  * enhancements.
  88  */
  89 static int mi_created_session(const char *session_name)
  90 {
  91         int ret, i, count, found;
  92         struct lttng_session *sessions;
  93
  94         /* session_name should not be null */
  95         assert(session_name);
  96         assert(writer);
  97
  98         count = lttng_list_sessions(&sessions);
  99         if (count < 0) {
 100                 ret = count;
 101                 ERR("%s", lttng_strerror(ret));
 102                 goto error;
 103         }
 104
 105         if (count == 0) {
 106                 ERR("Error session creation failed: session %s not found", session_name);
 107                 ret = -LTTNG_ERR_SESS_NOT_FOUND;
 108                 goto end;
 109         }
 110
 111         found = 0;
 112         for (i = 0; i < count; i++) {
 113                 if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 114                         found = 1;
 115                         ret = mi_lttng_session(writer, &sessions[i], 0);
 116                         if (ret) {
 117                                 goto error;
 118                         }
 119                         break;
 120                 }
 121         }
 122
 123         if (!found) {
 124                 ret = -LTTNG_ERR_SESS_NOT_FOUND;
 125         } else {
 126                 ret = CMD_SUCCESS;
 127         }
 128
 129 error:
 130         free(sessions);
 131 end:
 132         return ret;
 133 }
 134
 135 static
 136 struct lttng_session_descriptor *create_session_descriptor(void)
 137 {
 138         int ret;
 139         ssize_t uri_count;
 140         enum output_type output_type;
 141         struct lttng_uri *uris = NULL;
 142         struct lttng_session_descriptor *descriptor = NULL;
 143         const char *uri_str1 = NULL, *uri_str2 = NULL;
 144         char local_output_path[LTTNG_PATH_MAX] = {};
 145
 146         if (opt_no_output) {
 147                 output_type = OUTPUT_NONE;
 148         } else if (opt_output_path) {
 149                 char *expanded_output_path;
 150
 151                 output_type = OUTPUT_LOCAL;
 152                 expanded_output_path = utils_expand_path(opt_output_path);
 153                 if (!expanded_output_path) {
 154                         ERR("Failed to expand output path.");
 155                         goto end;
 156                 }
 157                 ret = lttng_strncpy(local_output_path, expanded_output_path,
 158                                 sizeof(local_output_path));
 159                 free(expanded_output_path);
 160                 if (ret) {
 161                         ERR("Output path exceeds the maximal supported length (%zu bytes)",
 162                                         sizeof(local_output_path));
 163                         goto end;
 164                 }
 165         } else if (opt_url || opt_ctrl_url) {
 166                 uri_str1 = opt_ctrl_url ? opt_ctrl_url : opt_url;
 167                 uri_str2 = opt_data_url;
 168
 169                 uri_count = uri_parse_str_urls(uri_str1, uri_str2, &uris);
 170                 if (uri_count != 1 && uri_count != 2) {
 171                         ERR("Unrecognized URL format.");
 172                         goto end;
 173                 }
 174
 175                 switch (uri_count) {
 176                 case 1:
 177                         output_type = OUTPUT_LOCAL;
 178                         if (uris[0].dtype != LTTNG_DST_PATH) {
 179                                 ERR("Unrecognized URL format.");
 180                                 goto end;
 181                         }
 182                         ret = lttng_strncpy(local_output_path, uris[0].dst.path,
 183                                         sizeof(local_output_path));
 184                         if (ret) {
 185                                 ERR("Output path exceeds the maximal supported length (%zu bytes)",
 186                                                 sizeof(local_output_path));
 187                         }
 188                         break;
 189                 case 2:
 190                         output_type = OUTPUT_NETWORK;
 191                         break;
 192                 default:
 193                         /* Already checked. */
 194                         abort();
 195                 }
 196         } else {
 197                 output_type = OUTPUT_UNSPECIFIED;
 198         }
 199
 200         if (opt_snapshot) {
 201                 /* Snapshot session. */
 202                 switch (output_type) {
 203                 case OUTPUT_UNSPECIFIED:
 204                 case OUTPUT_LOCAL:
 205                         descriptor = lttng_session_descriptor_snapshot_local_create(
 206                                         opt_session_name,
 207                                         output_type == OUTPUT_LOCAL ?
 208                                                 local_output_path : NULL);
 209                         break;
 210                 case OUTPUT_NONE:
 211                         descriptor = lttng_session_descriptor_snapshot_create(
 212                                         opt_session_name);
 213                         break;
 214                 case OUTPUT_NETWORK:
 215                         descriptor = lttng_session_descriptor_snapshot_network_create(
 216                                         opt_session_name, uri_str1, uri_str2);
 217                         break;
 218                 default:
 219                         abort();
 220                 }
 221         } else if (opt_live_timer) {
 222                 /* Live session. */
 223                 if (output_type != OUTPUT_UNSPECIFIED &&
 224                                 output_type != OUTPUT_NETWORK) {
 225                         ERR("Unsupported output type specified for live session.");
 226                         goto end;
 227                 }
 228                 descriptor = lttng_session_descriptor_live_network_create(
 229                                 opt_session_name, uri_str1, uri_str2,
 230                                 opt_live_timer);
 231         } else {
 232                 /* Regular session. */
 233                 switch (output_type) {
 234                 case OUTPUT_UNSPECIFIED:
 235                 case OUTPUT_LOCAL:
 236                         descriptor = lttng_session_descriptor_local_create(
 237                                         opt_session_name,
 238                                         output_type == OUTPUT_LOCAL ?
 239                                                 local_output_path : NULL);
 240                         break;
 241                 case OUTPUT_NONE:
 242                         descriptor = lttng_session_descriptor_create(
 243                                         opt_session_name);
 244                         break;
 245                 case OUTPUT_NETWORK:
 246                         descriptor = lttng_session_descriptor_network_create(
 247                                         opt_session_name, uri_str1, uri_str2);
 248                         break;
 249                 default:
 250                         abort();
 251                 }
 252         }
 253         if (!descriptor) {
 254                 ERR("Failed to initialize session creation command.");
 255         } else {
 256                 /*
 257                  * Auto-launch the relay daemon when a live session
 258                  * is created using default URLs.
 259                  */
 260                 if (!opt_url && !opt_ctrl_url && !opt_data_url &&
 261                                 opt_live_timer && !check_relayd()) {
 262                         int ret;
 263                         const char *pathname = opt_relayd_path ? :
 264                                         INSTALL_BIN_PATH "/lttng-relayd";
 265
 266                         ret = spawn_relayd(pathname, 0);
 267                         if (ret < 0) {
 268                                 lttng_session_descriptor_destroy(descriptor);
 269                                 descriptor = NULL;
 270                         }
 271                 }
 272         }
 273 end:
 274         free(uris);
 275         return descriptor;
 276 }
 277
 278 /*
 279  *  Create a tracing session.
 280  *  If no name is specified, a default name is generated.
 281  *
 282  *  Returns one of the CMD_* result constants.
 283  */
 284 static int create_session(void)
 285 {
 286         int ret, i;
 287         char shm_path[LTTNG_PATH_MAX] = {};
 288         struct lttng_session_descriptor *session_descriptor = NULL;
 289         enum lttng_session_descriptor_status descriptor_status;
 290         enum lttng_error_code ret_code;
 291         struct lttng_session *sessions = NULL;
 292         const struct lttng_session *created_session = NULL;
 293         const char *created_session_name;
 294
 295         /* Validate options. */
 296         if (opt_session_name) {
 297                 if (strlen(opt_session_name) > NAME_MAX) {
 298                         ERR("Session name too long. Length must be lower or equal to %d",
 299                                         NAME_MAX);
 300                         ret = CMD_ERROR;
 301                         goto error;
 302                 }
 303                 /*
 304                  * Check if the session name begins with "auto-" or is exactly "auto".
 305                  * Both are reserved for the default session name. See bug #449 to
 306                  * understand why we need to check both here.
 307                  */
 308                 if ((strncmp(opt_session_name, DEFAULT_SESSION_NAME "-",
 309                                         strlen(DEFAULT_SESSION_NAME) + 1) == 0) ||
 310                                 (strncmp(opt_session_name, DEFAULT_SESSION_NAME,
 311                                         strlen(DEFAULT_SESSION_NAME)) == 0 &&
 312                                 strlen(opt_session_name) == strlen(DEFAULT_SESSION_NAME))) {
 313                         ERR("%s is a reserved keyword for default session(s)",
 314                                         DEFAULT_SESSION_NAME);
 315                         ret = CMD_ERROR;
 316                         goto error;
 317                 }
 318         }
 319
 320         if (opt_snapshot && opt_live_timer) {
 321                 ERR("Snapshot and live modes are mutually exclusive.");
 322                 ret = CMD_ERROR;
 323                 goto error;
 324         }
 325
 326         if ((!opt_ctrl_url && opt_data_url) || (opt_ctrl_url && !opt_data_url)) {
 327                 ERR("Both control and data URLs must be specified.");
 328                 ret = CMD_ERROR;
 329                 goto error;
 330         }
 331
 332         session_descriptor = create_session_descriptor();
 333         if (!session_descriptor) {
 334                 ret = CMD_ERROR;
 335                 goto error;
 336         }
 337         ret_code = lttng_create_session_ext(session_descriptor);
 338         if (ret_code != LTTNG_OK) {
 339                 ERR("%s", lttng_strerror(-ret_code));
 340                 ret = CMD_ERROR;
 341                 goto error;
 342         }
 343
 344         descriptor_status = lttng_session_descriptor_get_session_name(
 345                 session_descriptor, &created_session_name);
 346         if (descriptor_status != LTTNG_SESSION_DESCRIPTOR_STATUS_OK) {
 347                 ERR("Failed to obtain created session name");
 348                 ret = CMD_ERROR;
 349                 goto error;
 350         }
 351
 352         ret = lttng_list_sessions(&sessions);
 353         if (ret < 0) {
 354                 ERR("Failed to fetch properties of created session: %s",
 355                                 lttng_strerror(ret));
 356                 ret = CMD_ERROR;
 357                 goto error;
 358         }
 359         for (i = 0; i < ret; i++) {
 360                 if (!strcmp(created_session_name, sessions[i].name)) {
 361                         created_session = &sessions[i];
 362                         break;
 363                 }
 364         }
 365         if (!created_session) {
 366                 ERR("Failed to fetch properties of created session");
 367                 ret = CMD_ERROR;
 368                 goto error;
 369         }
 370
 371         if (opt_shm_path) {
 372                 char datetime_suffix[17] = {};
 373
 374                 /*
 375                  * An auto-generated session name already includes the creation
 376                  * timestamp.
 377                  */
 378                 if (opt_session_name) {
 379                         uint64_t creation_time;
 380                         struct tm *timeinfo;
 381                         time_t creation_time_t;
 382                         size_t strftime_ret;
 383
 384                         ret_code = lttng_session_get_creation_time(
 385                                         created_session,
 386                                         &creation_time);
 387                         if (ret_code != LTTNG_OK) {
 388                                 ERR("%s", lttng_strerror(-ret_code));
 389                                 ret = CMD_ERROR;
 390                                 goto error;
 391                         }
 392                         creation_time_t = (time_t) creation_time;
 393                         timeinfo = localtime(&creation_time_t);
 394                         if (!timeinfo) {
 395                                 PERROR("Failed to interpret session creation time");
 396                                 ret = CMD_ERROR;
 397                                 goto error;
 398                         }
 399                         strftime_ret = strftime(datetime_suffix,
 400                                         sizeof(datetime_suffix),
 401                                         "-%Y%m%d-%H%M%S", timeinfo);
 402                         if (strftime_ret == 0) {
 403                                 ERR("Failed to format session creation time.");
 404                                 ret = CMD_ERROR;
 405                                 goto error;
 406                         }
 407                 }
 408
 409                 ret = snprintf(shm_path, sizeof(shm_path),
 410                                 "%s/%s%s", opt_shm_path, created_session_name,
 411                                 datetime_suffix);
 412                 if (ret < 0 || ret >= sizeof(shm_path)) {
 413                         ERR("Failed to format the shared memory path.");
 414                         ret = CMD_ERROR;
 415                         goto error;
 416                 }
 417                 ret = lttng_set_session_shm_path(created_session_name,
 418                                 shm_path);
 419                 if (ret < 0) {
 420                         lttng_destroy_session(created_session_name);
 421                         ret = CMD_ERROR;
 422                         goto error;
 423                 }
 424         }
 425
 426         if (opt_snapshot) {
 427                 MSG("Snapshot session %s created.", created_session_name);
 428         } else if (opt_live_timer) {
 429                 MSG("Live session %s created.", created_session_name);
 430         } else {
 431                 MSG("Session %s created.", created_session_name);
 432         }
 433
 434         if (*created_session->path && !opt_snapshot) {
 435                 MSG("Traces will be output to %s", created_session->path);
 436
 437                 if (opt_live_timer) {
 438                         MSG("Live timer interval set to %u %s", opt_live_timer,
 439                                         USEC_UNIT);
 440                 }
 441         } else if (opt_snapshot) {
 442                 struct lttng_snapshot_output_list *list;
 443                 struct lttng_snapshot_output *iter;
 444                 char snapshot_url[LTTNG_PATH_MAX] = {};
 445
 446                 ret = lttng_snapshot_list_output(created_session_name, &list);
 447                 if (ret < 0) {
 448                         ERR("Failed to list snapshot outputs.");
 449                         ret = CMD_ERROR;
 450                         goto error;
 451                 }
 452
 453                 while ((iter = lttng_snapshot_output_list_get_next(list))) {
 454                         const char *url = NULL;
 455
 456                         url = lttng_snapshot_output_get_ctrl_url(
 457                                         iter);
 458                         ret = lttng_strncpy(snapshot_url, url,
 459                                         sizeof(snapshot_url));
 460                         if (ret) {
 461                                 snapshot_url[0] = '\0';
 462                                 ERR("Failed to retrieve snapshot output destination");
 463                         }
 464                         break;
 465                 }
 466                 lttng_snapshot_output_list_destroy(list);
 467
 468                 if (*snapshot_url) {
 469                         MSG("Default snapshot output set to %s",
 470                                         snapshot_url);
 471                 }
 472                 MSG("Every channel enabled for this session will be set to mmap output and default to overwrite mode.");
 473         }
 474         if (opt_shm_path) {
 475                 MSG("Shared memory path set to %s", shm_path);
 476         }
 477
 478         /* Mi output */
 479         if (lttng_opt_mi) {
 480                 ret = mi_created_session(created_session_name);
 481                 if (ret) {
 482                         ret = CMD_ERROR;
 483                         goto error;
 484                 }
 485         }
 486
 487         /* Init lttng session config */
 488         ret = config_init(created_session_name);
 489         if (ret < 0) {
 490                 ret = CMD_ERROR;
 491                 goto error;
 492         }
 493
 494         ret = CMD_SUCCESS;
 495 error:
 496         lttng_session_descriptor_destroy(session_descriptor);
 497         free(sessions);
 498         return ret;
 499 }
 500
 501 /*
 502  *  spawn_sessiond
 503  *
 504  *  Spawn a session daemon by forking and execv.
 505  */
 506 static int spawn_sessiond(const char *pathname)
 507 {
 508         int ret = 0;
 509         pid_t pid;
 510
 511         MSG("Spawning a session daemon");
 512         pid = fork();
 513         if (pid == 0) {
 514                 /*
 515                  * Spawn session daemon in daemon mode.
 516                  */
 517                 execlp(pathname, "lttng-sessiond",
 518                                 "--daemonize", NULL);
 519                 /* execlp only returns if error happened */
 520                 if (errno == ENOENT) {
 521                         ERR("No session daemon found. Use --sessiond-path.");
 522                 } else {
 523                         PERROR("execlp");
 524                 }
 525                 kill(getppid(), SIGTERM);       /* wake parent */
 526                 exit(EXIT_FAILURE);
 527         } else if (pid > 0) {
 528                 /*
 529                  * In daemon mode (--daemonize), sessiond only exits when
 530                  * it's ready to accept commands.
 531                  */
 532                 for (;;) {
 533                         int status;
 534                         pid_t wait_pid_ret = waitpid(pid, &status, 0);
 535
 536                         if (wait_pid_ret < 0) {
 537                                 if (errno == EINTR) {
 538                                         continue;
 539                                 }
 540                                 PERROR("waitpid");
 541                                 ret = -errno;
 542                                 goto end;
 543                         }
 544
 545                         if (WIFSIGNALED(status)) {
 546                                 ERR("Session daemon was killed by signal %d",
 547                                                 WTERMSIG(status));
 548                                 ret = -1;
 549                                 goto end;
 550                         } else if (WIFEXITED(status)) {
 551                                 DBG("Session daemon terminated normally (exit status: %d)",
 552                                                 WEXITSTATUS(status));
 553
 554                                 if (WEXITSTATUS(status) != 0) {
 555                                         ERR("Session daemon terminated with an error (exit status: %d)",
 556                                                         WEXITSTATUS(status));
 557                                         ret = -1;
 558                                         goto end;
 559                                 }
 560                                 break;
 561                         }
 562                 }
 563
 564                 goto end;
 565         } else {
 566                 PERROR("fork");
 567                 ret = -1;
 568                 goto end;
 569         }
 570
 571 end:
 572         return ret;
 573 }
 574
 575 /*
 576  *  launch_sessiond
 577  *
 578  *  Check if the session daemon is available using
 579  *  the liblttngctl API for the check. If not, try to
 580  *  spawn a daemon.
 581  */
 582 static int launch_sessiond(void)
 583 {
 584         int ret;
 585         const char *pathname = NULL;
 586
 587         ret = lttng_session_daemon_alive();
 588         if (ret) {
 589                 /* Sessiond is alive, not an error */
 590                 ret = 0;
 591                 goto end;
 592         }
 593
 594         /* Try command line option path */
 595         pathname = opt_sessiond_path;
 596
 597         /* Try LTTNG_SESSIOND_PATH env variable */
 598         if (pathname == NULL) {
 599                 pathname = getenv(DEFAULT_SESSIOND_PATH_ENV);
 600         }
 601
 602         /* Try with configured path */
 603         if (pathname == NULL) {
 604                 if (CONFIG_SESSIOND_BIN[0] != '\0') {
 605                         pathname = CONFIG_SESSIOND_BIN;
 606                 }
 607         }
 608
 609         /* Try the default path */
 610         if (pathname == NULL) {
 611                 pathname = INSTALL_BIN_PATH "/lttng-sessiond";
 612         }
 613
 614         DBG("Session daemon binary path: %s", pathname);
 615
 616         /* Check existence and permissions */
 617         ret = access(pathname, F_OK | X_OK);
 618         if (ret < 0) {
 619                 ERR("No such file or access denied: %s", pathname);
 620                 goto end;
 621         }
 622
 623         ret = spawn_sessiond(pathname);
 624 end:
 625         if (ret) {
 626                 ERR("Problem occurred while launching session daemon (%s)",
 627                                 pathname);
 628         }
 629         return ret;
 630 }
 631
 632 static
 633 int validate_url_option_combination(void)
 634 {
 635         int ret = 0;
 636         int used_count = 0;
 637
 638         used_count += !!opt_url;
 639         used_count += !!opt_output_path;
 640         used_count += (opt_data_url || opt_ctrl_url);
 641         if (used_count > 1) {
 642                 ERR("Only one of the --set-url, --ctrl-url/data-url, or --output options may be used at once.");
 643                 ret = -1;
 644         }
 645
 646         return ret;
 647 }
 648
 649 /*
 650  *  The 'create <options>' first level command
 651  *
 652  *  Returns one of the CMD_* result constants.
 653  */
 654 int cmd_create(int argc, const char **argv)
 655 {
 656         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 657         char *opt_arg = NULL;
 658         const char *leftover = NULL;
 659         static poptContext pc;
 660
 661         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 662         poptReadDefaultConfig(pc, 0);
 663
 664         while ((opt = poptGetNextOpt(pc)) != -1) {
 665                 switch (opt) {
 666                 case OPT_HELP:
 667                         SHOW_HELP();
 668                         goto end;
 669                 case OPT_LIST_OPTIONS:
 670                         list_cmd_options(stdout, long_options);
 671                         goto end;
 672                 case OPT_LIVE_TIMER:
 673                 {
 674                         uint64_t v;
 675
 676                         errno = 0;
 677                         opt_arg = poptGetOptArg(pc);
 678                         if (!opt_arg) {
 679                                 /* Set up default values. */
 680                                 opt_live_timer = (uint32_t) DEFAULT_LTTNG_LIVE_TIMER;
 681                                 DBG("Session live timer interval set to default value %d",
 682                                                 opt_live_timer);
 683                                 break;
 684                         }
 685
 686                         if (utils_parse_time_suffix(opt_arg, &v) < 0) {
 687                                 ERR("Wrong value for --live parameter: %s", opt_arg);
 688                                 ret = CMD_ERROR;
 689                                 goto end;
 690                         }
 691
 692                         if (v != (uint32_t) v) {
 693                                 ERR("32-bit overflow in --live parameter: %s", opt_arg);
 694                                 ret = CMD_ERROR;
 695                                 goto end;
 696                         }
 697
 698                         if (v == 0) {
 699                                 ERR("Live timer interval must be greater than zero");
 700                                 ret = CMD_ERROR;
 701                                 goto end;
 702                         }
 703
 704                         opt_live_timer = (uint32_t) v;
 705                         DBG("Session live timer interval set to %d", opt_live_timer);
 706                         break;
 707                 }
 708                 default:
 709                         ret = CMD_UNDEFINED;
 710                         goto end;
 711                 }
 712         }
 713
 714         if (opt_no_consumer) {
 715                 MSG("The option --no-consumer is obsolete. Use --no-output now.");
 716                 ret = CMD_WARNING;
 717                 goto end;
 718         }
 719
 720         ret = validate_url_option_combination();
 721         if (ret) {
 722                 ret = CMD_ERROR;
 723                 goto end;
 724         }
 725
 726         /* Spawn a session daemon if needed */
 727         if (!opt_no_sessiond) {
 728                 ret = launch_sessiond();
 729                 if (ret) {
 730                         ret = CMD_ERROR;
 731                         goto end;
 732                 }
 733         }
 734
 735         /* MI initialization */
 736         if (lttng_opt_mi) {
 737                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 738                 if (!writer) {
 739                         ret = -LTTNG_ERR_NOMEM;
 740                         goto end;
 741                 }
 742
 743                 /* Open command element */
 744                 ret = mi_lttng_writer_command_open(writer,
 745                                 mi_lttng_element_command_create);
 746                 if (ret) {
 747                         ret = CMD_ERROR;
 748                         goto end;
 749                 }
 750
 751                 /* Open output element */
 752                 ret = mi_lttng_writer_open_element(writer,
 753                                 mi_lttng_element_command_output);
 754                 if (ret) {
 755                         ret = CMD_ERROR;
 756                         goto end;
 757                 }
 758         }
 759         opt_session_name = (char*) poptGetArg(pc);
 760
 761         leftover = poptGetArg(pc);
 762         if (leftover) {
 763                 ERR("Unknown argument: %s", leftover);
 764                 ret = CMD_ERROR;
 765                 goto end;
 766         }
 767
 768         command_ret = create_session();
 769         if (command_ret) {
 770                 success = 0;
 771         }
 772
 773         if (lttng_opt_mi) {
 774                 /* Close  output element */
 775                 ret = mi_lttng_writer_close_element(writer);
 776                 if (ret) {
 777                         ret = CMD_ERROR;
 778                         goto end;
 779                 }
 780
 781                 /* Success ? */
 782                 ret = mi_lttng_writer_write_element_bool(writer,
 783                                 mi_lttng_element_command_success, success);
 784                 if (ret) {
 785                         ret = CMD_ERROR;
 786                         goto end;
 787                 }
 788
 789                 /* Command element close */
 790                 ret = mi_lttng_writer_command_close(writer);
 791                 if (ret) {
 792                         ret = CMD_ERROR;
 793                         goto end;
 794                 }
 795         }
 796
 797 end:
 798         /* Mi clean-up */
 799         if (writer && mi_lttng_writer_destroy(writer)) {
 800                 /* Preserve original error code */
 801                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 802         }
 803
 804         /* Overwrite ret if an error occurred in create_session() */
 805         ret = command_ret ? command_ret : ret;
 806
 807         poptFreeContext(pc);
 808         return ret;
 809 }