src/bin/lttng/lttng.c

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