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