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         { "remove-trigger", cmd_remove_trigger},
  83         { "rotate", cmd_rotate},
  84         { "enable-rotation", cmd_enable_rotation},
  85         { "disable-rotation", cmd_disable_rotation},
  86         { "save", cmd_save},
  87         { "set-session", cmd_set_session},
  88         { "snapshot", cmd_snapshot},
  89         { "start", cmd_start},
  90         { "status", cmd_status},
  91         { "stop", cmd_stop},
  92         { "track", cmd_track},
  93         { "untrack", cmd_untrack},
  94         { "version", cmd_version},
  95         { "view", cmd_view},
  96         { NULL, NULL}   /* Array closure */
  97 };
  98
  99 static void version(FILE *ofp)
 100 {
 101         fprintf(ofp, "%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 = NULL;
 136
 137         option = &long_options[i];
 138         while (option->name != NULL) {
 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 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(void)
 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, NULL)) < 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 == NULL) {
 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 != NULL) {
 235                 /* Find command */
 236                 if (strcmp(argv[0], cmd->name) == 0) {
 237                         ret = cmd->func(argc, (const char**) argv);
 238                         goto end;
 239                 }
 240                 i++;
 241                 cmd = &commands[i];
 242         }
 243
 244         /* Command not found */
 245         ret = CMD_UNDEFINED;
 246
 247 end:
 248         return ret;
 249 }
 250
 251 static bool command_exists(const char *command)
 252 {
 253         const struct cmd_struct *cmd = commands;
 254         bool exists = false;
 255
 256         while (cmd->name != NULL) {
 257                 if (!strcmp(command, cmd->name)) {
 258                         exists = true;
 259                         goto end;
 260                 }
 261                 cmd++;
 262         }
 263
 264 end:
 265         return exists;
 266 }
 267
 268 static void show_basic_help(void)
 269 {
 270         puts("Usage: lttng [--group=GROUP] [--mi=TYPE] [--no-sessiond | --sessiond-path=PATH]");
 271         puts("             [--quiet | -v | -vv | -vvv] COMMAND [COMMAND OPTIONS]");
 272         puts("");
 273         puts("Available commands:");
 274         puts("");
 275         puts("Tracing sessions:");
 276         puts("  create            " CONFIG_CMD_DESCR_CREATE);
 277         puts("  clear             " CONFIG_CMD_DESCR_CLEAR);
 278         puts("  destroy           " CONFIG_CMD_DESCR_DESTROY);
 279         puts("  load              " CONFIG_CMD_DESCR_LOAD);
 280         puts("  regenerate        " CONFIG_CMD_DESCR_REGENERATE);
 281         puts("  save              " CONFIG_CMD_DESCR_SAVE);
 282         puts("  set-session       " CONFIG_CMD_DESCR_SET_SESSION);
 283         puts("");
 284         puts("Channels:");
 285         puts("  add-context       " CONFIG_CMD_DESCR_ADD_CONTEXT);
 286         puts("  disable-channel   " CONFIG_CMD_DESCR_DISABLE_CHANNEL);
 287         puts("  enable-channel    " CONFIG_CMD_DESCR_ENABLE_CHANNEL);
 288         puts("");
 289         puts("Event rules:");
 290         puts("  disable-event     " CONFIG_CMD_DESCR_DISABLE_EVENT);
 291         puts("  enable-event      " CONFIG_CMD_DESCR_ENABLE_EVENT);
 292         puts("");
 293         puts("Status:");
 294         puts("  list              " CONFIG_CMD_DESCR_LIST);
 295         puts("  status            " CONFIG_CMD_DESCR_STATUS);
 296         puts("");
 297         puts("Control:");
 298         puts("  snapshot          " CONFIG_CMD_DESCR_SNAPSHOT);
 299         puts("  start             " CONFIG_CMD_DESCR_START);
 300         puts("  stop              " CONFIG_CMD_DESCR_STOP);
 301         puts("");
 302         puts("Tracing session rotation:");
 303         puts("  disable-rotation  " CONFIG_CMD_DESCR_DISABLE_ROTATION);
 304         puts("  enable-rotation   " CONFIG_CMD_DESCR_ENABLE_ROTATION);
 305         puts("  rotate            " CONFIG_CMD_DESCR_ROTATE);
 306         puts("");
 307         puts("Resource tracking:");
 308         puts("  track             " CONFIG_CMD_DESCR_TRACK);
 309         puts("  untrack           " CONFIG_CMD_DESCR_UNTRACK);
 310         puts("");
 311         puts("Miscellaneous:");
 312         puts("  help              " CONFIG_CMD_DESCR_HELP);
 313         puts("  version           " CONFIG_CMD_DESCR_VERSION);
 314         puts("  view              " CONFIG_CMD_DESCR_VIEW);
 315         puts("");
 316         puts("Run `lttng help COMMAND` or `lttng COMMAND --help` to get help with");
 317         puts("command COMMAND.");
 318         puts("");
 319         puts("See `man lttng` for more help with the lttng command.");
 320 }
 321
 322 /*
 323  * Parse command line arguments.
 324  *
 325  * Return 0 if OK, else -1
 326  */
 327 static int parse_args(int argc, char **argv)
 328 {
 329         int opt, ret;
 330
 331         if (lttng_is_setuid_setgid()) {
 332                 ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.", argv[0]);
 333                 clean_exit(EXIT_FAILURE);
 334         }
 335
 336         if (argc < 2) {
 337                 show_basic_help();
 338                 clean_exit(EXIT_FAILURE);
 339         }
 340
 341         while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, NULL)) != -1) {
 342                 switch (opt) {
 343                 case 'V':
 344                         version(stdout);
 345                         ret = 0;
 346                         goto end;
 347                 case 'h':
 348                         ret = utils_show_help(1, "lttng", help_msg);
 349                         if (ret) {
 350                                 ERR("Cannot show --help for `lttng`");
 351                                 perror("exec");
 352                         }
 353                         goto end;
 354                 case 'v':
 355                         /* There is only 3 possible level of verbosity. (-vvv) */
 356                         if (lttng_opt_verbose < 3) {
 357                                 lttng_opt_verbose += 1;
 358                         }
 359                         break;
 360                 case 'q':
 361                         lttng_opt_quiet = 1;
 362                         break;
 363                 case 'm':
 364                         lttng_opt_mi = mi_output_type(optarg);
 365                         if (lttng_opt_mi < 0) {
 366                                 ret = lttng_opt_mi;
 367                                 goto error;
 368                         }
 369                         break;
 370                 case 'g':
 371                         lttng_set_tracing_group(optarg);
 372                         break;
 373                 case 'n':
 374                         opt_no_sessiond = 1;
 375                         break;
 376                 case OPT_SESSION_PATH:
 377                         free(opt_sessiond_path);
 378                         opt_sessiond_path = strdup(optarg);
 379                         if (!opt_sessiond_path) {
 380                                 ret = -1;
 381                                 goto error;
 382                         }
 383                         break;
 384                 case OPT_RELAYD_PATH:
 385                         free(opt_relayd_path);
 386                         opt_relayd_path = strdup(optarg);
 387                         if (!opt_relayd_path) {
 388                                 ret = -1;
 389                                 goto error;
 390                         }
 391                         break;
 392                 case OPT_DUMP_OPTIONS:
 393                         list_options(stdout);
 394                         ret = 0;
 395                         goto end;
 396                 case OPT_DUMP_COMMANDS:
 397                         list_commands(commands, stdout);
 398                         ret = 0;
 399                         goto end;
 400                 default:
 401                         ret = 1;
 402                         goto error;
 403                 }
 404         }
 405
 406         /* If both options are specified, quiet wins */
 407         if (lttng_opt_verbose && lttng_opt_quiet) {
 408                 lttng_opt_verbose = 0;
 409         }
 410
 411         /* No leftovers, quit */
 412         if ((argc - optind) == 0) {
 413                 ret = 1;
 414                 goto error;
 415         }
 416
 417         /*
 418          * Handle leftovers which is a first level command with the trailing
 419          * options.
 420          */
 421         ret = handle_command(argc - optind, argv + optind);
 422         switch (ret) {
 423         case CMD_WARNING:
 424         case CMD_ERROR:
 425                 break;
 426         case CMD_UNDEFINED:
 427                 if (!command_exists(*(argv + optind))) {
 428                         MSG("lttng: %s is not an lttng command. See 'lttng --help'.",
 429                                         *(argv + optind));
 430                 } else {
 431                         ERR("Unrecognized argument used with \'%s\' command",
 432                                         *(argv + optind));
 433                 }
 434                 break;
 435         case CMD_FATAL:
 436         case CMD_UNSUPPORTED:
 437                 break;
 438         case -1:
 439                 ret = 1;
 440                 break;
 441         case 0:
 442                 break;
 443         default:
 444                 if (ret < 0) {
 445                         ret = -ret;
 446                 }
 447                 break;
 448         }
 449
 450 end:
 451 error:
 452         return ret;
 453 }
 454
 455
 456 /*
 457  *  main
 458  */
 459 int main(int argc, char *argv[])
 460 {
 461         int ret;
 462
 463         progname = argv[0] ? argv[0] : "lttng";
 464
 465         ret = set_signal_handler();
 466         if (ret < 0) {
 467                 clean_exit(ret);
 468         }
 469
 470         ret = parse_args(argc, argv);
 471         if (ret != 0) {
 472                 clean_exit(ret);
 473         }
 474
 475         return 0;
 476 }