src/bin/lttng/lttng.c

   1 /*
   2  * Copyright (c)  2011 David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  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 #include <ctype.h>
  28
  29 #include <lttng/lttng.h>
  30 #include <common/error.h>
  31 #include <common/compat/getenv.h>
  32 #include <common/utils.h>
  33
  34 #include "command.h"
  35
  36 static const char *help_msg =
  37 #ifdef LTTNG_EMBED_HELP
  38 #include <lttng.1.h>
  39 #else
  40 NULL
  41 #endif
  42 ;
  43
  44 /* Variables */
  45 static char *progname;
  46 int opt_no_sessiond;
  47 char *opt_sessiond_path;
  48
  49 char *opt_relayd_path;
  50
  51 enum {
  52         OPT_RELAYD_PATH,
  53         OPT_SESSION_PATH,
  54         OPT_DUMP_OPTIONS,
  55         OPT_DUMP_COMMANDS,
  56 };
  57
  58 /* Getopt options. No first level command. */
  59 static struct option long_options[] = {
  60         {"version",          0, NULL, 'V'},
  61         {"help",             0, NULL, 'h'},
  62         {"group",            1, NULL, 'g'},
  63         {"verbose",          0, NULL, 'v'},
  64         {"quiet",            0, NULL, 'q'},
  65         {"mi",               1, NULL, 'm'},
  66         {"no-sessiond",      0, NULL, 'n'},
  67         {"sessiond-path",    1, NULL, OPT_SESSION_PATH},
  68         {"relayd-path",      1, NULL, OPT_RELAYD_PATH},
  69         {"list-options",     0, NULL, OPT_DUMP_OPTIONS},
  70         {"list-commands",    0, NULL, OPT_DUMP_COMMANDS},
  71         {NULL, 0, NULL, 0}
  72 };
  73
  74 /* First level command */
  75 static struct cmd_struct commands[] =  {
  76         { "add-context", cmd_add_context},
  77         { "create", cmd_create},
  78         { "destroy", cmd_destroy},
  79         { "disable-channel", cmd_disable_channels},
  80         { "disable-event", cmd_disable_events},
  81         { "enable-channel", cmd_enable_channels},
  82         { "enable-event", cmd_enable_events},
  83         { "help", NULL},
  84         { "list", cmd_list},
  85         { "load", cmd_load},
  86         { "metadata", cmd_metadata},
  87         { "regenerate", cmd_regenerate},
  88         { "save", cmd_save},
  89         { "set-session", cmd_set_session},
  90         { "snapshot", cmd_snapshot},
  91         { "start", cmd_start},
  92         { "status", cmd_status},
  93         { "stop", cmd_stop},
  94         { "track", cmd_track},
  95         { "untrack", cmd_untrack},
  96         { "version", cmd_version},
  97         { "view", cmd_view},
  98         { NULL, NULL}   /* Array closure */
  99 };
 100
 101 static void version(FILE *ofp)
 102 {
 103         fprintf(ofp, "%s (LTTng Trace Control) " VERSION" - " VERSION_NAME "%s\n",
 104                         progname,
 105                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION);
 106 }
 107
 108 /*
 109  * Find the MI output type enum from a string. This function is for the support
 110  * of machine interface output.
 111  */
 112 static int mi_output_type(const char *output_type)
 113 {
 114         int ret = 0;
 115
 116         if (!strncasecmp("xml", output_type, 3)) {
 117                 ret = LTTNG_MI_XML;
 118         } else {
 119                 /* Invalid output format */
 120                 ERR("MI output format not supported");
 121                 ret = -LTTNG_ERR_MI_OUTPUT_TYPE;
 122         }
 123
 124         return ret;
 125 }
 126
 127 /*
 128  *  list_options
 129  *
 130  *  List options line by line. This is mostly for bash auto completion and to
 131  *  avoid difficult parsing.
 132  */
 133 static void list_options(FILE *ofp)
 134 {
 135         int i = 0;
 136         struct option *option = NULL;
 137
 138         option = &long_options[i];
 139         while (option->name != NULL) {
 140                 fprintf(ofp, "--%s\n", option->name);
 141
 142                 if (isprint(option->val)) {
 143                         fprintf(ofp, "-%c\n", option->val);
 144                 }
 145
 146                 i++;
 147                 option = &long_options[i];
 148         }
 149 }
 150
 151 /*
 152  * clean_exit
 153  */
 154 static void clean_exit(int code)
 155 {
 156         DBG("Clean exit");
 157         exit(code);
 158 }
 159
 160 /*
 161  *  sighandler
 162  *
 163  *  Signal handler for the daemon
 164  */
 165 static void sighandler(int sig)
 166 {
 167         switch (sig) {
 168                 case SIGTERM:
 169                         DBG("SIGTERM caught");
 170                         clean_exit(EXIT_FAILURE);
 171                         break;
 172                 default:
 173                         DBG("Unknown signal %d caught", sig);
 174                         break;
 175         }
 176
 177         return;
 178 }
 179
 180 /*
 181  *  set_signal_handler
 182  *
 183  *  Setup signal handler for SIGCHLD and SIGTERM.
 184  */
 185 static int set_signal_handler(void)
 186 {
 187         int ret = 0;
 188         struct sigaction sa;
 189         sigset_t sigset;
 190
 191         if ((ret = sigemptyset(&sigset)) < 0) {
 192                 PERROR("sigemptyset");
 193                 goto end;
 194         }
 195
 196         sa.sa_handler = sighandler;
 197         sa.sa_mask = sigset;
 198         sa.sa_flags = 0;
 199
 200         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 201                 PERROR("sigaction");
 202                 goto end;
 203         }
 204
 205 end:
 206         return ret;
 207 }
 208
 209 /*
 210  *  handle_command
 211  *
 212  *  Handle the full argv list of a first level command. Will find the command
 213  *  in the global commands array and call the function callback associated.
 214  *
 215  *  If command not found, return -1
 216  *  else, return function command error code.
 217  */
 218 static int handle_command(int argc, char **argv)
 219 {
 220         int i = 0, ret;
 221         struct cmd_struct *cmd;
 222
 223         if (*argv == NULL) {
 224                 ret = CMD_SUCCESS;
 225                 goto end;
 226         }
 227
 228         /* Special case for help command which needs the commands array */
 229         if (strcmp(argv[0], "help") == 0) {
 230                 ret = cmd_help(argc, (const char**) argv, commands);
 231                 goto end;
 232         }
 233
 234         cmd = &commands[i];
 235         while (cmd->name != NULL) {
 236                 /* Find command */
 237                 if (strcmp(argv[0], cmd->name) == 0) {
 238                         ret = cmd->func(argc, (const char**) argv);
 239                         goto end;
 240                 }
 241                 i++;
 242                 cmd = &commands[i];
 243         }
 244
 245         /* Command not found */
 246         ret = CMD_UNDEFINED;
 247
 248 end:
 249         return ret;
 250 }
 251
 252 static void show_basic_help(void)
 253 {
 254         puts("Usage: lttng [--group=GROUP] [--mi=TYPE] [--no-sessiond | --sessiond-path=PATH]");
 255         puts("             [--quiet | -v | -vv | -vvv] COMMAND [COMMAND OPTIONS]");
 256         puts("");
 257         puts("Available commands:");
 258         puts("");
 259         puts("Tracing sessions:");
 260         puts("  create            " CONFIG_CMD_DESCR_CREATE);
 261         puts("  destroy           " CONFIG_CMD_DESCR_DESTROY);
 262         puts("  load              " CONFIG_CMD_DESCR_LOAD);
 263         puts("  regenerate        " CONFIG_CMD_DESCR_REGENERATE);
 264         puts("  save              " CONFIG_CMD_DESCR_SAVE);
 265         puts("  set-session       " CONFIG_CMD_DESCR_SET_SESSION);
 266         puts("");
 267         puts("Channels:");
 268         puts("  add-context       " CONFIG_CMD_DESCR_ADD_CONTEXT);
 269         puts("  disable-channel   " CONFIG_CMD_DESCR_DISABLE_CHANNEL);
 270         puts("  enable-channel    " CONFIG_CMD_DESCR_ENABLE_CHANNEL);
 271         puts("");
 272         puts("Event rules:");
 273         puts("  disable-event     " CONFIG_CMD_DESCR_DISABLE_EVENT);
 274         puts("  enable-event      " CONFIG_CMD_DESCR_ENABLE_EVENT);
 275         puts("");
 276         puts("Status:");
 277         puts("  list              " CONFIG_CMD_DESCR_LIST);
 278         puts("  status            " CONFIG_CMD_DESCR_STATUS);
 279         puts("");
 280         puts("Control:");
 281         puts("  snapshot          " CONFIG_CMD_DESCR_SNAPSHOT);
 282         puts("  start             " CONFIG_CMD_DESCR_START);
 283         puts("  stop              " CONFIG_CMD_DESCR_STOP);
 284         puts("");
 285         puts("Resource tracking:");
 286         puts("  track             " CONFIG_CMD_DESCR_TRACK);
 287         puts("  untrack           " CONFIG_CMD_DESCR_UNTRACK);
 288         puts("");
 289         puts("Miscellaneous:");
 290         puts("  help              " CONFIG_CMD_DESCR_HELP);
 291         puts("  version           " CONFIG_CMD_DESCR_VERSION);
 292         puts("  view              " CONFIG_CMD_DESCR_VIEW);
 293         puts("");
 294         puts("Run `lttng help COMMAND` or `lttng COMMAND --help` to get help with");
 295         puts("command COMMAND.");
 296         puts("");
 297         puts("See `man lttng` for more help with the lttng command.");
 298 }
 299
 300 /*
 301  * Parse command line arguments.
 302  *
 303  * Return 0 if OK, else -1
 304  */
 305 static int parse_args(int argc, char **argv)
 306 {
 307         int opt, ret;
 308
 309         if (lttng_is_setuid_setgid()) {
 310                 ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.", argv[0]);
 311                 clean_exit(EXIT_FAILURE);
 312         }
 313
 314         if (argc < 2) {
 315                 show_basic_help();
 316                 clean_exit(EXIT_FAILURE);
 317         }
 318
 319         while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, NULL)) != -1) {
 320                 switch (opt) {
 321                 case 'V':
 322                         version(stdout);
 323                         ret = 0;
 324                         goto end;
 325                 case 'h':
 326                         ret = utils_show_help(1, "lttng", help_msg);
 327                         if (ret) {
 328                                 ERR("Cannot show --help for `lttng`");
 329                                 perror("exec");
 330                         }
 331                         goto end;
 332                 case 'v':
 333                         /* There is only 3 possible level of verbosity. (-vvv) */
 334                         if (lttng_opt_verbose < 3) {
 335                                 lttng_opt_verbose += 1;
 336                         }
 337                         break;
 338                 case 'q':
 339                         lttng_opt_quiet = 1;
 340                         break;
 341                 case 'm':
 342                         lttng_opt_mi = mi_output_type(optarg);
 343                         if (lttng_opt_mi < 0) {
 344                                 ret = lttng_opt_mi;
 345                                 goto error;
 346                         }
 347                         break;
 348                 case 'g':
 349                         lttng_set_tracing_group(optarg);
 350                         break;
 351                 case 'n':
 352                         opt_no_sessiond = 1;
 353                         break;
 354                 case OPT_SESSION_PATH:
 355                         free(opt_sessiond_path);
 356                         opt_sessiond_path = strdup(optarg);
 357                         if (!opt_sessiond_path) {
 358                                 ret = -1;
 359                                 goto error;
 360                         }
 361                         break;
 362                 case OPT_RELAYD_PATH:
 363                         free(opt_relayd_path);
 364                         opt_relayd_path = strdup(optarg);
 365                         if (!opt_relayd_path) {
 366                                 ret = -1;
 367                                 goto error;
 368                         }
 369                         break;
 370                 case OPT_DUMP_OPTIONS:
 371                         list_options(stdout);
 372                         ret = 0;
 373                         goto end;
 374                 case OPT_DUMP_COMMANDS:
 375                         list_commands(commands, stdout);
 376                         ret = 0;
 377                         goto end;
 378                 default:
 379                         ret = 1;
 380                         goto error;
 381                 }
 382         }
 383
 384         /* If both options are specified, quiet wins */
 385         if (lttng_opt_verbose && lttng_opt_quiet) {
 386                 lttng_opt_verbose = 0;
 387         }
 388
 389         /* No leftovers, quit */
 390         if ((argc - optind) == 0) {
 391                 ret = 1;
 392                 goto error;
 393         }
 394
 395         /*
 396          * Handle leftovers which is a first level command with the trailing
 397          * options.
 398          */
 399         ret = handle_command(argc - optind, argv + optind);
 400         switch (ret) {
 401         case CMD_WARNING:
 402                 WARN("Some command(s) went wrong");
 403                 break;
 404         case CMD_ERROR:
 405                 ERR("Command error");
 406                 break;
 407         case CMD_UNDEFINED:
 408                 ERR("Undefined command or invalid arguments");
 409                 break;
 410         case CMD_FATAL:
 411                 ERR("Fatal error");
 412                 break;
 413         case CMD_UNSUPPORTED:
 414                 ERR("Unsupported command");
 415                 break;
 416         case -1:
 417                 ret = 1;
 418                 break;
 419         case 0:
 420                 break;
 421         default:
 422                 if (ret < 0) {
 423                         ret = -ret;
 424                 }
 425                 break;
 426         }
 427
 428 end:
 429 error:
 430         return ret;
 431 }
 432
 433
 434 /*
 435  *  main
 436  */
 437 int main(int argc, char *argv[])
 438 {
 439         int ret;
 440
 441         progname = argv[0] ? argv[0] : "lttng";
 442
 443         ret = set_signal_handler();
 444         if (ret < 0) {
 445                 clean_exit(ret);
 446         }
 447
 448         ret = parse_args(argc, argv);
 449         if (ret != 0) {
 450                 clean_exit(ret);
 451         }
 452
 453         return 0;
 454 }