src/bin/lttng/commands/create.cpp

   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 <common/compat/time.hpp>
  11 #include <ctype.h>
  12 #include <functional>
  13 #include <popt.h>
  14 #include <signal.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <sys/stat.h>
  19 #include <sys/types.h>
  20 #include <sys/wait.h>
  21 #include <unistd.h>
  22 #include <unordered_map>
  23
  24 #include <common/mi-lttng.hpp>
  25
  26 #include "../command.hpp"
  27 #include "../utils.hpp"
  28
  29 #include <common/defaults.hpp>
  30 #include <common/sessiond-comm/sessiond-comm.hpp>
  31 #include <common/uri.hpp>
  32 #include <common/utils.hpp>
  33 #include <common/path.hpp>
  34 #include <lttng/lttng.h>
  35
  36 static char *opt_output_path;
  37 static char *opt_session_name;
  38 static char *opt_url;
  39 static char *opt_ctrl_url;
  40 static char *opt_data_url;
  41 static char *opt_shm_path;
  42 static char *opt_trace_format;
  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         {"trace-format",    0, POPT_ARG_STRING, &opt_trace_format, 0, 0, 0},
  82         {0, 0, 0, 0, 0, 0, 0}
  83 };
  84
  85 /*
  86  * Retrieve the created session and mi output it based on provided argument
  87  * This is currently a summary of what was pretty printed and is subject to
  88  * enhancements.
  89  */
  90 static int mi_created_session(const char *session_name)
  91 {
  92         int ret, i, count, found;
  93         struct lttng_session *sessions;
  94
  95         /* session_name should not be null */
  96         LTTNG_ASSERT(session_name);
  97         LTTNG_ASSERT(writer);
  98
  99         count = lttng_list_sessions(&sessions);
 100         if (count < 0) {
 101                 ret = count;
 102                 ERR("%s", lttng_strerror(ret));
 103                 goto error;
 104         }
 105
 106         if (count == 0) {
 107                 ERR("Error session creation failed: session %s not found", session_name);
 108                 ret = -LTTNG_ERR_SESS_NOT_FOUND;
 109                 goto end;
 110         }
 111
 112         found = 0;
 113         for (i = 0; i < count; i++) {
 114                 if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 115                         found = 1;
 116                         ret = mi_lttng_session(writer, &sessions[i], 0);
 117                         if (ret) {
 118                                 goto error;
 119                         }
 120                         break;
 121                 }
 122         }
 123
 124         if (!found) {
 125                 ret = -LTTNG_ERR_SESS_NOT_FOUND;
 126         } else {
 127                 ret = CMD_SUCCESS;
 128         }
 129
 130 error:
 131         free(sessions);
 132 end:
 133         return ret;
 134 }
 135
 136 static
 137 struct lttng_session_descriptor *create_session_descriptor(void)
 138 {
 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                 int ret;
 151
 152                 output_type = OUTPUT_LOCAL;
 153                 expanded_output_path = utils_expand_path(opt_output_path);
 154                 if (!expanded_output_path) {
 155                         ERR("Failed to expand output path.");
 156                         goto end;
 157                 }
 158                 ret = lttng_strncpy(local_output_path, expanded_output_path,
 159                                 sizeof(local_output_path));
 160                 free(expanded_output_path);
 161                 if (ret) {
 162                         ERR("Output path exceeds the maximal supported length (%zu bytes)",
 163                                         sizeof(local_output_path));
 164                         goto end;
 165                 }
 166         } else if (opt_url || opt_ctrl_url) {
 167                 int ret;
 168
 169                 uri_str1 = opt_ctrl_url ? opt_ctrl_url : opt_url;
 170                 uri_str2 = opt_data_url;
 171
 172                 uri_count = uri_parse_str_urls(uri_str1, uri_str2, &uris);
 173                 if (uri_count != 1 && uri_count != 2) {
 174                         ERR("Unrecognized URL format.");
 175                         goto end;
 176                 }
 177
 178                 switch (uri_count) {
 179                 case 1:
 180                         output_type = OUTPUT_LOCAL;
 181                         if (uris[0].dtype != LTTNG_DST_PATH) {
 182                                 ERR("Unrecognized URL format.");
 183                                 goto end;
 184                         }
 185                         ret = lttng_strncpy(local_output_path, uris[0].dst.path,
 186                                         sizeof(local_output_path));
 187                         if (ret) {
 188                                 ERR("Output path exceeds the maximal supported length (%zu bytes)",
 189                                                 sizeof(local_output_path));
 190                         }
 191                         break;
 192                 case 2:
 193                         output_type = OUTPUT_NETWORK;
 194                         break;
 195                 default:
 196                         /* Already checked. */
 197                         abort();
 198                 }
 199         } else {
 200                 output_type = OUTPUT_UNSPECIFIED;
 201         }
 202
 203         if (opt_snapshot) {
 204                 /* Snapshot session. */
 205                 switch (output_type) {
 206                 case OUTPUT_UNSPECIFIED:
 207                 case OUTPUT_LOCAL:
 208                         descriptor = lttng_session_descriptor_snapshot_local_create(
 209                                         opt_session_name,
 210                                         output_type == OUTPUT_LOCAL ?
 211                                                 local_output_path : NULL);
 212                         break;
 213                 case OUTPUT_NONE:
 214                         descriptor = lttng_session_descriptor_snapshot_create(
 215                                         opt_session_name);
 216                         break;
 217                 case OUTPUT_NETWORK:
 218                         descriptor = lttng_session_descriptor_snapshot_network_create(
 219                                         opt_session_name, uri_str1, uri_str2);
 220                         break;
 221                 default:
 222                         abort();
 223                 }
 224         } else if (opt_live_timer) {
 225                 /* Live session. */
 226                 if (output_type != OUTPUT_UNSPECIFIED &&
 227                                 output_type != OUTPUT_NETWORK) {
 228                         ERR("Unsupported output type specified for live session.");
 229                         goto end;
 230                 }
 231                 descriptor = lttng_session_descriptor_live_network_create(
 232                                 opt_session_name, uri_str1, uri_str2,
 233                                 opt_live_timer);
 234         } else {
 235                 /* Regular session. */
 236                 switch (output_type) {
 237                 case OUTPUT_UNSPECIFIED:
 238                 case OUTPUT_LOCAL:
 239                         descriptor = lttng_session_descriptor_local_create(
 240                                         opt_session_name,
 241                                         output_type == OUTPUT_LOCAL ?
 242                                                 local_output_path : NULL);
 243                         break;
 244                 case OUTPUT_NONE:
 245                         descriptor = lttng_session_descriptor_create(
 246                                         opt_session_name);
 247                         break;
 248                 case OUTPUT_NETWORK:
 249                         descriptor = lttng_session_descriptor_network_create(
 250                                         opt_session_name, uri_str1, uri_str2);
 251                         break;
 252                 default:
 253                         abort();
 254                 }
 255         }
 256         if (!descriptor) {
 257                 ERR("Failed to initialize session creation command.");
 258         } else {
 259                 /*
 260                  * Auto-launch the relay daemon when a live session
 261                  * is created using default URLs.
 262                  */
 263                 if (!opt_url && !opt_ctrl_url && !opt_data_url &&
 264                                 opt_live_timer && !check_relayd()) {
 265                         int ret;
 266                         const char *pathname = opt_relayd_path ? :
 267                                         INSTALL_BIN_PATH "/lttng-relayd";
 268
 269                         ret = spawn_relayd(pathname, 0);
 270                         if (ret < 0) {
 271                                 goto error;
 272                         }
 273                 }
 274         }
 275
 276         if (opt_trace_format) {
 277                 std::unordered_map<std::string,
 278                                 std::function<struct lttng_trace_format_descriptor *()>>
 279                                 factory = {
 280                                                 {"ctf1", lttng_trace_format_ctf_1_descriptor_create},
 281                                                 {"ctf2", lttng_trace_format_ctf_2_descriptor_create},
 282                                 };
 283
 284                 lttng_session_descriptor_status status;
 285                 lttng_trace_format_descriptor *trace_format_descriptor = nullptr;
 286                 std::string s_trace_format(opt_trace_format);
 287
 288                 auto it = factory.find(s_trace_format);
 289
 290                 if (it == factory.end()) {
 291                         ERR("Unknown trace format");
 292                         goto error;
 293                 }
 294
 295                 trace_format_descriptor = it->second();
 296                 if (trace_format_descriptor == nullptr) {
 297                         ERR("Failed to create trace format descriptor for trace format %s",
 298                                         opt_trace_format);
 299                         goto error;
 300                 }
 301
 302                 status = lttng_session_descriptor_set_trace_format_descriptor(
 303                                 descriptor, trace_format_descriptor);
 304                 lttng_trace_format_descriptor_destroy(trace_format_descriptor);
 305                 if (status != LTTNG_SESSION_DESCRIPTOR_STATUS_OK) {
 306                         ERR("Failed to set trace format descriptor");
 307                         goto error;
 308                 }
 309         }
 310 end:
 311         free(uris);
 312         return descriptor;
 313 error:
 314         lttng_session_descriptor_destroy(descriptor);
 315         descriptor = NULL;
 316         goto end;
 317 }
 318
 319 /*
 320  *  Create a tracing session.
 321  *  If no name is specified, a default name is generated.
 322  *
 323  *  Returns one of the CMD_* result constants.
 324  */
 325 static int create_session(void)
 326 {
 327         int ret, i;
 328         char shm_path[LTTNG_PATH_MAX] = {};
 329         struct lttng_session_descriptor *session_descriptor = NULL;
 330         enum lttng_session_descriptor_status descriptor_status;
 331         enum lttng_error_code ret_code;
 332         struct lttng_session *sessions = NULL;
 333         const struct lttng_session *created_session = NULL;
 334         const char *created_session_name;
 335
 336         /* Validate options. */
 337         if (opt_session_name) {
 338                 if (strlen(opt_session_name) > NAME_MAX) {
 339                         ERR("Session name too long. Length must be lower or equal to %d",
 340                                         NAME_MAX);
 341                         ret = CMD_ERROR;
 342                         goto error;
 343                 }
 344                 /*
 345                  * Check if the session name begins with "auto-" or is exactly "auto".
 346                  * Both are reserved for the default session name. See bug #449 to
 347                  * understand why we need to check both here.
 348                  */
 349                 if ((strncmp(opt_session_name, DEFAULT_SESSION_NAME "-",
 350                                         strlen(DEFAULT_SESSION_NAME) + 1) == 0) ||
 351                                 (strncmp(opt_session_name, DEFAULT_SESSION_NAME,
 352                                         strlen(DEFAULT_SESSION_NAME)) == 0 &&
 353                                 strlen(opt_session_name) == strlen(DEFAULT_SESSION_NAME))) {
 354                         ERR("%s is a reserved keyword for default session(s)",
 355                                         DEFAULT_SESSION_NAME);
 356                         ret = CMD_ERROR;
 357                         goto error;
 358                 }
 359         }
 360
 361         if (opt_snapshot && opt_live_timer) {
 362                 ERR("Snapshot and live modes are mutually exclusive.");
 363                 ret = CMD_ERROR;
 364                 goto error;
 365         }
 366
 367         if ((!opt_ctrl_url && opt_data_url) || (opt_ctrl_url && !opt_data_url)) {
 368                 ERR("Both control and data URLs must be specified.");
 369                 ret = CMD_ERROR;
 370                 goto error;
 371         }
 372
 373         session_descriptor = create_session_descriptor();
 374         if (!session_descriptor) {
 375                 ret = CMD_ERROR;
 376                 goto error;
 377         }
 378         ret_code = lttng_create_session_ext(session_descriptor);
 379         if (ret_code != LTTNG_OK) {
 380                 ERR("%s", lttng_strerror(-ret_code));
 381                 ret = CMD_ERROR;
 382                 goto error;
 383         }
 384
 385         descriptor_status = lttng_session_descriptor_get_session_name(
 386                 session_descriptor, &created_session_name);
 387         if (descriptor_status != LTTNG_SESSION_DESCRIPTOR_STATUS_OK) {
 388                 ERR("Failed to obtain created session name");
 389                 ret = CMD_ERROR;
 390                 goto error;
 391         }
 392
 393         ret = lttng_list_sessions(&sessions);
 394         if (ret < 0) {
 395                 ERR("Failed to fetch properties of created session: %s",
 396                                 lttng_strerror(ret));
 397                 ret = CMD_ERROR;
 398                 goto error;
 399         }
 400         for (i = 0; i < ret; i++) {
 401                 if (!strcmp(created_session_name, sessions[i].name)) {
 402                         created_session = &sessions[i];
 403                         break;
 404                 }
 405         }
 406         if (!created_session) {
 407                 ERR("Failed to fetch properties of created session");
 408                 ret = CMD_ERROR;
 409                 goto error;
 410         }
 411
 412         if (opt_shm_path) {
 413                 char datetime_suffix[17] = {};
 414
 415                 /*
 416                  * An auto-generated session name already includes the creation
 417                  * timestamp.
 418                  */
 419                 if (opt_session_name) {
 420                         uint64_t creation_time;
 421                         struct tm *timeinfo;
 422                         time_t creation_time_t;
 423                         size_t strftime_ret;
 424
 425                         ret_code = lttng_session_get_creation_time(
 426                                         created_session,
 427                                         &creation_time);
 428                         if (ret_code != LTTNG_OK) {
 429                                 ERR("%s", lttng_strerror(-ret_code));
 430                                 ret = CMD_ERROR;
 431                                 goto error;
 432                         }
 433                         creation_time_t = (time_t) creation_time;
 434                         timeinfo = localtime(&creation_time_t);
 435                         if (!timeinfo) {
 436                                 PERROR("Failed to interpret session creation time");
 437                                 ret = CMD_ERROR;
 438                                 goto error;
 439                         }
 440                         strftime_ret = strftime(datetime_suffix,
 441                                         sizeof(datetime_suffix),
 442                                         "-%Y%m%d-%H%M%S", timeinfo);
 443                         if (strftime_ret == 0) {
 444                                 ERR("Failed to format session creation time.");
 445                                 ret = CMD_ERROR;
 446                                 goto error;
 447                         }
 448                 }
 449
 450                 ret = snprintf(shm_path, sizeof(shm_path),
 451                                 "%s/%s%s", opt_shm_path, created_session_name,
 452                                 datetime_suffix);
 453                 if (ret < 0 || ret >= sizeof(shm_path)) {
 454                         ERR("Failed to format the shared memory path.");
 455                         ret = CMD_ERROR;
 456                         goto error;
 457                 }
 458                 ret = lttng_set_session_shm_path(created_session_name,
 459                                 shm_path);
 460                 if (ret < 0) {
 461                         lttng_destroy_session(created_session_name);
 462                         ret = CMD_ERROR;
 463                         goto error;
 464                 }
 465         }
 466
 467         if (opt_snapshot) {
 468                 MSG("Snapshot session %s created.", created_session_name);
 469         } else if (opt_live_timer) {
 470                 MSG("Live session %s created.", created_session_name);
 471         } else {
 472                 MSG("Session %s created.", created_session_name);
 473         }
 474
 475         if (*created_session->path && !opt_snapshot) {
 476                 MSG("Traces will be output to %s", created_session->path);
 477
 478                 if (opt_live_timer) {
 479                         MSG("Live timer interval set to %u %s", opt_live_timer,
 480                                         USEC_UNIT);
 481                 }
 482         } else if (opt_snapshot) {
 483                 struct lttng_snapshot_output_list *list;
 484                 struct lttng_snapshot_output *iter;
 485                 char snapshot_url[LTTNG_PATH_MAX] = {};
 486
 487                 ret = lttng_snapshot_list_output(created_session_name, &list);
 488                 if (ret < 0) {
 489                         ERR("Failed to list snapshot outputs.");
 490                         ret = CMD_ERROR;
 491                         goto error;
 492                 }
 493
 494                 while ((iter = lttng_snapshot_output_list_get_next(list))) {
 495                         const char *url = NULL;
 496
 497                         url = lttng_snapshot_output_get_ctrl_url(
 498                                         iter);
 499                         ret = lttng_strncpy(snapshot_url, url,
 500                                         sizeof(snapshot_url));
 501                         if (ret) {
 502                                 snapshot_url[0] = '\0';
 503                                 ERR("Failed to retrieve snapshot output destination");
 504                         }
 505                         break;
 506                 }
 507                 lttng_snapshot_output_list_destroy(list);
 508
 509                 if (*snapshot_url) {
 510                         MSG("Default snapshot output set to %s",
 511                                         snapshot_url);
 512                 }
 513                 MSG("Every channel enabled for this session will be set to mmap output and default to overwrite mode.");
 514         }
 515         if (opt_shm_path) {
 516                 MSG("Shared memory path set to %s", shm_path);
 517         }
 518
 519         /* Mi output */
 520         if (lttng_opt_mi) {
 521                 ret = mi_created_session(created_session_name);
 522                 if (ret) {
 523                         ret = CMD_ERROR;
 524                         goto error;
 525                 }
 526         }
 527
 528         /* Init lttng session config */
 529         ret = config_init(created_session_name);
 530         if (ret < 0) {
 531                 ret = CMD_ERROR;
 532                 goto error;
 533         }
 534
 535         ret = CMD_SUCCESS;
 536 error:
 537         lttng_session_descriptor_destroy(session_descriptor);
 538         free(sessions);
 539         return ret;
 540 }
 541
 542 /*
 543  *  spawn_sessiond
 544  *
 545  *  Spawn a session daemon by forking and execv.
 546  */
 547 static int spawn_sessiond(const char *pathname)
 548 {
 549         int ret = 0;
 550         pid_t pid;
 551
 552         MSG("Spawning a session daemon");
 553         pid = fork();
 554         if (pid == 0) {
 555                 /*
 556                  * Spawn session daemon in daemon mode.
 557                  */
 558                 execlp(pathname, "lttng-sessiond",
 559                                 "--daemonize", NULL);
 560                 /* execlp only returns if error happened */
 561                 if (errno == ENOENT) {
 562                         ERR("No session daemon found. Use --sessiond-path.");
 563                 } else {
 564                         PERROR("execlp");
 565                 }
 566                 kill(getppid(), SIGTERM);       /* wake parent */
 567                 exit(EXIT_FAILURE);
 568         } else if (pid > 0) {
 569                 /*
 570                  * In daemon mode (--daemonize), sessiond only exits when
 571                  * it's ready to accept commands.
 572                  */
 573                 for (;;) {
 574                         int status;
 575                         pid_t wait_pid_ret = waitpid(pid, &status, 0);
 576
 577                         if (wait_pid_ret < 0) {
 578                                 if (errno == EINTR) {
 579                                         continue;
 580                                 }
 581                                 PERROR("waitpid");
 582                                 ret = -errno;
 583                                 goto end;
 584                         }
 585
 586                         if (WIFSIGNALED(status)) {
 587                                 ERR("Session daemon was killed by signal %d",
 588                                                 WTERMSIG(status));
 589                                 ret = -1;
 590                                 goto end;
 591                         } else if (WIFEXITED(status)) {
 592                                 DBG("Session daemon terminated normally (exit status: %d)",
 593                                                 WEXITSTATUS(status));
 594
 595                                 if (WEXITSTATUS(status) != 0) {
 596                                         ERR("Session daemon terminated with an error (exit status: %d)",
 597                                                         WEXITSTATUS(status));
 598                                         ret = -1;
 599                                         goto end;
 600                                 }
 601                                 break;
 602                         }
 603                 }
 604
 605                 goto end;
 606         } else {
 607                 PERROR("fork");
 608                 ret = -1;
 609                 goto end;
 610         }
 611
 612 end:
 613         return ret;
 614 }
 615
 616 /*
 617  *  launch_sessiond
 618  *
 619  *  Check if the session daemon is available using
 620  *  the liblttngctl API for the check. If not, try to
 621  *  spawn a daemon.
 622  */
 623 static int launch_sessiond(void)
 624 {
 625         int ret;
 626         const char *pathname = NULL;
 627
 628         ret = lttng_session_daemon_alive();
 629         if (ret) {
 630                 /* Sessiond is alive, not an error */
 631                 ret = 0;
 632                 goto end;
 633         }
 634
 635         /* Try command line option path */
 636         pathname = opt_sessiond_path;
 637
 638         /* Try LTTNG_SESSIOND_PATH env variable */
 639         if (pathname == NULL) {
 640                 pathname = getenv(DEFAULT_SESSIOND_PATH_ENV);
 641         }
 642
 643         /* Try with configured path */
 644         if (pathname == NULL) {
 645                 if (CONFIG_SESSIOND_BIN[0] != '\0') {
 646                         pathname = CONFIG_SESSIOND_BIN;
 647                 }
 648         }
 649
 650         /* Try the default path */
 651         if (pathname == NULL) {
 652                 pathname = INSTALL_BIN_PATH "/lttng-sessiond";
 653         }
 654
 655         DBG("Session daemon binary path: %s", pathname);
 656
 657         /* Check existence and permissions */
 658         ret = access(pathname, F_OK | X_OK);
 659         if (ret < 0) {
 660                 ERR("No such file or access denied: %s", pathname);
 661                 goto end;
 662         }
 663
 664         ret = spawn_sessiond(pathname);
 665 end:
 666         if (ret) {
 667                 ERR("Problem occurred while launching session daemon (%s)",
 668                                 pathname);
 669         }
 670         return ret;
 671 }
 672
 673 static
 674 int validate_url_option_combination(void)
 675 {
 676         int ret = 0;
 677         int used_count = 0;
 678
 679         used_count += !!opt_url;
 680         used_count += !!opt_output_path;
 681         used_count += (opt_data_url || opt_ctrl_url);
 682         if (used_count > 1) {
 683                 ERR("Only one of the --set-url, --ctrl-url/data-url, or --output options may be used at once.");
 684                 ret = -1;
 685         }
 686
 687         return ret;
 688 }
 689
 690 /*
 691  *  The 'create <options>' first level command
 692  *
 693  *  Returns one of the CMD_* result constants.
 694  */
 695 int cmd_create(int argc, const char **argv)
 696 {
 697         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 698         char *opt_arg = NULL;
 699         const char *leftover = NULL;
 700         static poptContext pc;
 701
 702         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 703         poptReadDefaultConfig(pc, 0);
 704
 705         while ((opt = poptGetNextOpt(pc)) != -1) {
 706                 switch (opt) {
 707                 case OPT_HELP:
 708                         SHOW_HELP();
 709                         goto end;
 710                 case OPT_LIST_OPTIONS:
 711                         list_cmd_options(stdout, long_options);
 712                         goto end;
 713                 case OPT_LIVE_TIMER:
 714                 {
 715                         uint64_t v;
 716
 717                         errno = 0;
 718                         if (opt_arg) {
 719                                 free(opt_arg);
 720                                 opt_arg = nullptr;
 721                         }
 722
 723                         opt_arg = poptGetOptArg(pc);
 724                         if (!opt_arg) {
 725                                 /* Set up default values. */
 726                                 opt_live_timer = (uint32_t) DEFAULT_LTTNG_LIVE_TIMER;
 727                                 DBG("Session live timer interval set to default value %d",
 728                                                 opt_live_timer);
 729                                 break;
 730                         }
 731
 732                         if (utils_parse_time_suffix(opt_arg, &v) < 0) {
 733                                 ERR("Wrong value for --live parameter: %s", opt_arg);
 734                                 ret = CMD_ERROR;
 735                                 goto end;
 736                         }
 737
 738                         if (v != (uint32_t) v) {
 739                                 ERR("32-bit overflow in --live parameter: %s", opt_arg);
 740                                 ret = CMD_ERROR;
 741                                 goto end;
 742                         }
 743
 744                         if (v == 0) {
 745                                 ERR("Live timer interval must be greater than zero");
 746                                 ret = CMD_ERROR;
 747                                 goto end;
 748                         }
 749
 750                         opt_live_timer = (uint32_t) v;
 751                         DBG("Session live timer interval set to %d", opt_live_timer);
 752                         break;
 753                 }
 754                 default:
 755                         ret = CMD_UNDEFINED;
 756                         goto end;
 757                 }
 758         }
 759
 760         if (opt_no_consumer) {
 761                 MSG("The option --no-consumer is obsolete. Use --no-output now.");
 762                 ret = CMD_WARNING;
 763                 goto end;
 764         }
 765
 766         ret = validate_url_option_combination();
 767         if (ret) {
 768                 ret = CMD_ERROR;
 769                 goto end;
 770         }
 771
 772         /* Spawn a session daemon if needed */
 773         if (!opt_no_sessiond) {
 774                 ret = launch_sessiond();
 775                 if (ret) {
 776                         ret = CMD_ERROR;
 777                         goto end;
 778                 }
 779         }
 780
 781         /* MI initialization */
 782         if (lttng_opt_mi) {
 783                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 784                 if (!writer) {
 785                         ret = -LTTNG_ERR_NOMEM;
 786                         goto end;
 787                 }
 788
 789                 /* Open command element */
 790                 ret = mi_lttng_writer_command_open(writer,
 791                                 mi_lttng_element_command_create);
 792                 if (ret) {
 793                         ret = CMD_ERROR;
 794                         goto end;
 795                 }
 796
 797                 /* Open output element */
 798                 ret = mi_lttng_writer_open_element(writer,
 799                                 mi_lttng_element_command_output);
 800                 if (ret) {
 801                         ret = CMD_ERROR;
 802                         goto end;
 803                 }
 804         }
 805         opt_session_name = (char*) poptGetArg(pc);
 806
 807         leftover = poptGetArg(pc);
 808         if (leftover) {
 809                 ERR("Unknown argument: %s", leftover);
 810                 ret = CMD_ERROR;
 811                 goto end;
 812         }
 813
 814         command_ret = create_session();
 815         if (command_ret) {
 816                 success = 0;
 817         }
 818
 819         if (lttng_opt_mi) {
 820                 /* Close  output element */
 821                 ret = mi_lttng_writer_close_element(writer);
 822                 if (ret) {
 823                         ret = CMD_ERROR;
 824                         goto end;
 825                 }
 826
 827                 /* Success ? */
 828                 ret = mi_lttng_writer_write_element_bool(writer,
 829                                 mi_lttng_element_command_success, success);
 830                 if (ret) {
 831                         ret = CMD_ERROR;
 832                         goto end;
 833                 }
 834
 835                 /* Command element close */
 836                 ret = mi_lttng_writer_command_close(writer);
 837                 if (ret) {
 838                         ret = CMD_ERROR;
 839                         goto end;
 840                 }
 841         }
 842
 843 end:
 844         /* Mi clean-up */
 845         if (writer && mi_lttng_writer_destroy(writer)) {
 846                 /* Preserve original error code */
 847                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 848         }
 849
 850         /* Overwrite ret if an error occurred in create_session() */
 851         ret = command_ret ? command_ret : ret;
 852
 853         free(opt_arg);
 854         poptFreeContext(pc);
 855         return ret;
 856 }