src/bin/lttng/lttng.cpp

   1 /*
   2  * Copyright (C) 2011 EfficiOS Inc.
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include "command.hpp"
  10 #include "version.hpp"
  11
  12 #include <common/compat/getenv.hpp>
  13 #include <common/error.hpp>
  14 #include <common/utils.hpp>
  15
  16 #include <lttng/lttng.h>
  17
  18 #include <ctype.h>
  19 #include <getopt.h>
  20 #include <signal.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/types.h>
  25 #include <sys/wait.h>
  26 #include <unistd.h>
  27
  28 static const char *help_msg =
  29 #ifdef LTTNG_EMBED_HELP
  30 #include <lttng.1.h>
  31 #else
  32         nullptr
  33 #endif
  34         ;
  35
  36 /* Variables */
  37 static const char *progname;
  38 int opt_no_sessiond;
  39 char *opt_sessiond_path;
  40
  41 char *opt_relayd_path;
  42
  43 enum {
  44         OPT_RELAYD_PATH,
  45         OPT_SESSION_PATH,
  46         OPT_DUMP_OPTIONS,
  47         OPT_DUMP_COMMANDS,
  48 };
  49
  50 /* Getopt options. No first level command. */
  51 static struct option long_options[] = { { "version", 0, nullptr, 'V' },
  52                                         { "help", 0, nullptr, 'h' },
  53                                         { "group", 1, nullptr, 'g' },
  54                                         { "verbose", 0, nullptr, 'v' },
  55                                         { "quiet", 0, nullptr, 'q' },
  56                                         { "mi", 1, nullptr, 'm' },
  57                                         { "no-sessiond", 0, nullptr, 'n' },
  58                                         { "sessiond-path", 1, nullptr, OPT_SESSION_PATH },
  59                                         { "relayd-path", 1, nullptr, OPT_RELAYD_PATH },
  60                                         { "list-options", 0, nullptr, OPT_DUMP_OPTIONS },
  61                                         { "list-commands", 0, nullptr, OPT_DUMP_COMMANDS },
  62                                         { nullptr, 0, nullptr, 0 } };
  63
  64 /* First level command */
  65 static struct cmd_struct commands[] = {
  66         { "add-context", cmd_add_context },
  67         { "add-trigger", cmd_add_trigger },
  68         { "create", cmd_create },
  69         { "clear", cmd_clear },
  70         { "destroy", cmd_destroy },
  71         { "disable-channel", cmd_disable_channels },
  72         { "disable-event", cmd_disable_events },
  73         { "enable-channel", cmd_enable_channels },
  74         { "enable-event", cmd_enable_events },
  75         { "help", nullptr },
  76         { "list", cmd_list },
  77         { "list-triggers", cmd_list_triggers },
  78         { "load", cmd_load },
  79         { "metadata", cmd_metadata },
  80         { "regenerate", cmd_regenerate },
  81         { "remove-trigger", cmd_remove_trigger },
  82         { "rotate", cmd_rotate },
  83         { "enable-rotation", cmd_enable_rotation },
  84         { "disable-rotation", cmd_disable_rotation },
  85         { "save", cmd_save },
  86         { "set-session", cmd_set_session },
  87         { "snapshot", cmd_snapshot },
  88         { "start", cmd_start },
  89         { "status", cmd_status },
  90         { "stop", cmd_stop },
  91         { "track", cmd_track },
  92         { "untrack", cmd_untrack },
  93         { "version", cmd_version },
  94         { "view", cmd_view },
  95         { nullptr, nullptr } /* Array closure */
  96 };
  97
  98 static void version(FILE *ofp)
  99 {
 100         fprintf(ofp,
 101                 "%s (LTTng Trace Control) " VERSION " - " VERSION_NAME "%s%s\n",
 102                 progname,
 103                 GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION,
 104                 EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " EXTRA_VERSION_NAME);
 105 }
 106
 107 /*
 108  * Find the MI output type enum from a string. This function is for the support
 109  * of machine interface output.
 110  */
 111 static int mi_output_type(const char *output_type)
 112 {
 113         int ret = 0;
 114
 115         if (!strncasecmp("xml", output_type, 3)) {
 116                 ret = LTTNG_MI_XML;
 117         } else {
 118                 /* Invalid output format */
 119                 ERR("MI output format not supported");
 120                 ret = -LTTNG_ERR_MI_OUTPUT_TYPE;
 121         }
 122
 123         return ret;
 124 }
 125
 126 /*
 127  *  list_options
 128  *
 129  *  List options line by line. This is mostly for bash auto completion and to
 130  *  avoid difficult parsing.
 131  */
 132 static void list_options(FILE *ofp)
 133 {
 134         int i = 0;
 135         struct option *option = nullptr;
 136
 137         option = &long_options[i];
 138         while (option->name != nullptr) {
 139                 fprintf(ofp, "--%s\n", option->name);
 140
 141                 if (isprint(option->val)) {
 142                         fprintf(ofp, "-%c\n", option->val);
 143                 }
 144
 145                 i++;
 146                 option = &long_options[i];
 147         }
 148 }
 149
 150 /*
 151  * clean_exit
 152  */
 153 __attribute__((noreturn)) static void clean_exit(int code)
 154 {
 155         DBG("Clean exit");
 156         exit(code);
 157 }
 158
 159 /*
 160  *  sighandler
 161  *
 162  *  Signal handler for the daemon
 163  */
 164 static void sighandler(int sig)
 165 {
 166         switch (sig) {
 167         case SIGTERM:
 168                 DBG("SIGTERM caught");
 169                 clean_exit(EXIT_FAILURE);
 170                 break;
 171         default:
 172                 DBG("Unknown signal %d caught", sig);
 173                 break;
 174         }
 175
 176         return;
 177 }
 178
 179 /*
 180  *  set_signal_handler
 181  *
 182  *  Setup signal handler for SIGCHLD and SIGTERM.
 183  */
 184 static int set_signal_handler()
 185 {
 186         int ret = 0;
 187         struct sigaction sa;
 188         sigset_t sigset;
 189
 190         if ((ret = sigemptyset(&sigset)) < 0) {
 191                 PERROR("sigemptyset");
 192                 goto end;
 193         }
 194
 195         sa.sa_handler = sighandler;
 196         sa.sa_mask = sigset;
 197         sa.sa_flags = 0;
 198
 199         if ((ret = sigaction(SIGTERM, &sa, nullptr)) < 0) {
 200                 PERROR("sigaction");
 201                 goto end;
 202         }
 203
 204 end:
 205         return ret;
 206 }
 207
 208 /*
 209  *  handle_command
 210  *
 211  *  Handle the full argv list of a first level command. Will find the command
 212  *  in the global commands array and call the function callback associated.
 213  *
 214  *  If command not found, return -1
 215  *  else, return function command error code.
 216  */
 217 static int handle_command(int argc, char **argv)
 218 {
 219         int i = 0, ret;
 220         struct cmd_struct *cmd;
 221
 222         if (*argv == nullptr) {
 223                 ret = CMD_SUCCESS;
 224                 goto end;
 225         }
 226
 227         /* Special case for help command which needs the commands array */
 228         if (strcmp(argv[0], "help") == 0) {
 229                 ret = cmd_help(argc, (const char **) argv, commands);
 230                 goto end;
 231         }
 232
 233         cmd = &commands[i];
 234         while (cmd->name != nullptr) {
 235                 /* Find command */
 236                 if (strcmp(argv[0], cmd->name) == 0) {
 237                         try {
 238                                 ret = cmd->func(argc, (const char **) argv);
 239                         } catch (const std::exception& e) {
 240                                 ERR_FMT("{}", e.what());
 241                                 ret = CMD_ERROR;
 242                         }
 243
 244                         goto end;
 245                 }
 246                 i++;
 247                 cmd = &commands[i];
 248         }
 249
 250         /* Command not found */
 251         ret = CMD_UNDEFINED;
 252
 253 end:
 254         return ret;
 255 }
 256
 257 static bool command_exists(const char *command)
 258 {
 259         const struct cmd_struct *cmd = commands;
 260         bool exists = false;
 261
 262         while (cmd->name != nullptr) {
 263                 if (!strcmp(command, cmd->name)) {
 264                         exists = true;
 265                         goto end;
 266                 }
 267                 cmd++;
 268         }
 269
 270 end:
 271         return exists;
 272 }
 273
 274 static void show_basic_help()
 275 {
 276         puts("Usage: lttng [--group=GROUP] [--mi=TYPE] [--no-sessiond | --sessiond-path=PATH]");
 277         puts("             [--quiet | -v | -vv | -vvv] COMMAND [COMMAND OPTIONS]");
 278         puts("");
 279         puts("Available commands:");
 280         puts("");
 281         puts("Recording sessions:");
 282         puts("  create            " CONFIG_CMD_DESCR_CREATE);
 283         puts("  clear             " CONFIG_CMD_DESCR_CLEAR);
 284         puts("  destroy           " CONFIG_CMD_DESCR_DESTROY);
 285         puts("  load              " CONFIG_CMD_DESCR_LOAD);
 286         puts("  regenerate        " CONFIG_CMD_DESCR_REGENERATE);
 287         puts("  save              " CONFIG_CMD_DESCR_SAVE);
 288         puts("  set-session       " CONFIG_CMD_DESCR_SET_SESSION);
 289         puts("");
 290         puts("Channels:");
 291         puts("  add-context       " CONFIG_CMD_DESCR_ADD_CONTEXT);
 292         puts("  disable-channel   " CONFIG_CMD_DESCR_DISABLE_CHANNEL);
 293         puts("  enable-channel    " CONFIG_CMD_DESCR_ENABLE_CHANNEL);
 294         puts("");
 295         puts("Recording event rules:");
 296         puts("  disable-event     " CONFIG_CMD_DESCR_DISABLE_EVENT);
 297         puts("  enable-event      " CONFIG_CMD_DESCR_ENABLE_EVENT);
 298         puts("");
 299         puts("Status:");
 300         puts("  list              " CONFIG_CMD_DESCR_LIST);
 301         puts("  status            " CONFIG_CMD_DESCR_STATUS);
 302         puts("");
 303         puts("Control:");
 304         puts("  snapshot          " CONFIG_CMD_DESCR_SNAPSHOT);
 305         puts("  start             " CONFIG_CMD_DESCR_START);
 306         puts("  stop              " CONFIG_CMD_DESCR_STOP);
 307         puts("");
 308         puts("Recording session rotation:");
 309         puts("  disable-rotation  " CONFIG_CMD_DESCR_DISABLE_ROTATION);
 310         puts("  enable-rotation   " CONFIG_CMD_DESCR_ENABLE_ROTATION);
 311         puts("  rotate            " CONFIG_CMD_DESCR_ROTATE);
 312         puts("");
 313         puts("Resource tracking:");
 314         puts("  track             " CONFIG_CMD_DESCR_TRACK);
 315         puts("  untrack           " CONFIG_CMD_DESCR_UNTRACK);
 316         puts("");
 317         puts("Triggers:");
 318         puts("  add-trigger       " CONFIG_CMD_DESCR_ADD_TRIGGER);
 319         puts("  remove-trigger    " CONFIG_CMD_DESCR_REMOVE_TRIGGER);
 320         puts("  list-triggers     " CONFIG_CMD_DESCR_LIST_TRIGGERS);
 321         puts("");
 322         puts("Miscellaneous:");
 323         puts("  help              " CONFIG_CMD_DESCR_HELP);
 324         puts("  version           " CONFIG_CMD_DESCR_VERSION);
 325         puts("  view              " CONFIG_CMD_DESCR_VIEW);
 326         puts("");
 327         puts("Run `lttng help COMMAND` or `lttng COMMAND --help` to get help with");
 328         puts("command COMMAND.");
 329         puts("");
 330         puts("See `man lttng` for more help with the lttng command.");
 331 }
 332
 333 /*
 334  * Parse command line arguments.
 335  *
 336  * Return 0 if OK, else -1
 337  */
 338 static int parse_args(int argc, char **argv)
 339 {
 340         int opt, ret;
 341
 342         if (lttng_is_setuid_setgid()) {
 343                 ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.",
 344                     argv[0]);
 345                 clean_exit(EXIT_FAILURE);
 346         }
 347
 348         if (argc < 2) {
 349                 show_basic_help();
 350                 clean_exit(EXIT_FAILURE);
 351         }
 352
 353         while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, nullptr)) != -1) {
 354                 switch (opt) {
 355                 case 'V':
 356                         version(stdout);
 357                         ret = 0;
 358                         goto end;
 359                 case 'h':
 360                         ret = utils_show_help(1, "lttng", help_msg);
 361                         if (ret) {
 362                                 ERR("Cannot show --help for `lttng`");
 363                                 perror("exec");
 364                         }
 365                         goto end;
 366                 case 'v':
 367                         /* There is only 3 possible level of verbosity. (-vvv) */
 368                         if (lttng_opt_verbose < 3) {
 369                                 lttng_opt_verbose += 1;
 370                         }
 371                         break;
 372                 case 'q':
 373                         lttng_opt_quiet = 1;
 374                         break;
 375                 case 'm':
 376                         lttng_opt_mi = mi_output_type(optarg);
 377                         if (lttng_opt_mi < 0) {
 378                                 ret = lttng_opt_mi;
 379                                 goto error;
 380                         }
 381                         break;
 382                 case 'g':
 383                         lttng_set_tracing_group(optarg);
 384                         break;
 385                 case 'n':
 386                         opt_no_sessiond = 1;
 387                         break;
 388                 case OPT_SESSION_PATH:
 389                         free(opt_sessiond_path);
 390                         opt_sessiond_path = strdup(optarg);
 391                         if (!opt_sessiond_path) {
 392                                 ret = -1;
 393                                 goto error;
 394                         }
 395                         break;
 396                 case OPT_RELAYD_PATH:
 397                         free(opt_relayd_path);
 398                         opt_relayd_path = strdup(optarg);
 399                         if (!opt_relayd_path) {
 400                                 ret = -1;
 401                                 goto error;
 402                         }
 403                         break;
 404                 case OPT_DUMP_OPTIONS:
 405                         list_options(stdout);
 406                         ret = 0;
 407                         goto end;
 408                 case OPT_DUMP_COMMANDS:
 409                         list_commands(commands, stdout);
 410                         ret = 0;
 411                         goto end;
 412                 default:
 413                         ret = 1;
 414                         goto error;
 415                 }
 416         }
 417
 418         /* If both options are specified, quiet wins */
 419         if (lttng_opt_verbose && lttng_opt_quiet) {
 420                 lttng_opt_verbose = 0;
 421         }
 422
 423         /* No leftovers, quit */
 424         if ((argc - optind) == 0) {
 425                 ret = 1;
 426                 goto error;
 427         }
 428
 429         /*
 430          * Handle leftovers which is a first level command with the trailing
 431          * options.
 432          */
 433         ret = handle_command(argc - optind, argv + optind);
 434         switch (ret) {
 435         case CMD_WARNING:
 436         case CMD_ERROR:
 437                 break;
 438         case CMD_UNDEFINED:
 439                 if (!command_exists(*(argv + optind))) {
 440                         MSG("lttng: %s is not an lttng command. See 'lttng --help'.",
 441                             *(argv + optind));
 442                 } else {
 443                         ERR("Unrecognized argument used with \'%s\' command", *(argv + optind));
 444                 }
 445                 break;
 446         case CMD_FATAL:
 447         case CMD_UNSUPPORTED:
 448                 break;
 449         case -1:
 450                 ret = 1;
 451                 break;
 452         case 0:
 453                 break;
 454         default:
 455                 if (ret < 0) {
 456                         ret = -ret;
 457                 }
 458                 break;
 459         }
 460
 461 end:
 462 error:
 463         return ret;
 464 }
 465
 466 /*
 467  *  main
 468  */
 469 static int _main(int argc, char *argv[])
 470 {
 471         int ret;
 472
 473         progname = argv[0] ? argv[0] : "lttng";
 474
 475         ret = set_signal_handler();
 476         if (ret < 0) {
 477                 clean_exit(ret);
 478         }
 479
 480         ret = parse_args(argc, argv);
 481         if (ret != 0) {
 482                 clean_exit(ret);
 483         }
 484
 485         return 0;
 486 }
 487
 488 int main(int argc, char **argv)
 489 {
 490         try {
 491                 return _main(argc, argv);
 492         } catch (const std::exception& e) {
 493                 ERR_FMT("Unhandled exception caught by client: %s", e.what());
 494                 abort();
 495         }
 496 }