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