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 #include "version.h"
  36
  37 static const char *help_msg =
  38 #ifdef LTTNG_EMBED_HELP
  39 #include <lttng.1.h>
  40 #else
  41 NULL
  42 #endif
  43 ;
  44
  45 /* Variables */
  46 static char *progname;
  47 int opt_no_sessiond;
  48 char *opt_sessiond_path;
  49
  50 char *opt_relayd_path;
  51
  52 enum {
  53         OPT_RELAYD_PATH,
  54         OPT_SESSION_PATH,
  55         OPT_DUMP_OPTIONS,
  56         OPT_DUMP_COMMANDS,
  57 };
  58
  59 /* Getopt options. No first level command. */
  60 static struct option long_options[] = {
  61         {"version",          0, NULL, 'V'},
  62         {"help",             0, NULL, 'h'},
  63         {"group",            1, NULL, 'g'},
  64         {"verbose",          0, NULL, 'v'},
  65         {"quiet",            0, NULL, 'q'},
  66         {"mi",               1, NULL, 'm'},
  67         {"no-sessiond",      0, NULL, 'n'},
  68         {"sessiond-path",    1, NULL, OPT_SESSION_PATH},
  69         {"relayd-path",      1, NULL, OPT_RELAYD_PATH},
  70         {"list-options",     0, NULL, OPT_DUMP_OPTIONS},
  71         {"list-commands",    0, NULL, OPT_DUMP_COMMANDS},
  72         {NULL, 0, NULL, 0}
  73 };
  74
  75 /* First level command */
  76 static struct cmd_struct commands[] =  {
  77         { "add-context", cmd_add_context},
  78         { "create", cmd_create},
  79         { "destroy", cmd_destroy},
  80         { "disable-channel", cmd_disable_channels},
  81         { "disable-event", cmd_disable_events},
  82         { "enable-channel", cmd_enable_channels},
  83         { "enable-event", cmd_enable_events},
  84         { "help", NULL},
  85         { "list", cmd_list},
  86         { "load", cmd_load},
  87         { "metadata", cmd_metadata},
  88         { "regenerate", cmd_regenerate},
  89         { "rotate", cmd_rotate},
  90         { "enable-rotation", cmd_enable_rotation},
  91         { "disable-rotation", cmd_disable_rotation},
  92         { "save", cmd_save},
  93         { "set-session", cmd_set_session},
  94         { "snapshot", cmd_snapshot},
  95         { "start", cmd_start},
  96         { "status", cmd_status},
  97         { "stop", cmd_stop},
  98         { "track", cmd_track},
  99         { "untrack", cmd_untrack},
 100         { "version", cmd_version},
 101         { "view", cmd_view},
 102         { NULL, NULL}   /* Array closure */
 103 };
 104
 105 static void version(FILE *ofp)
 106 {
 107         fprintf(ofp, "%s (LTTng Trace Control) " VERSION" - " VERSION_NAME "%s\n",
 108                         progname,
 109                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION);
 110 }
 111
 112 /*
 113  * Find the MI output type enum from a string. This function is for the support
 114  * of machine interface output.
 115  */
 116 static int mi_output_type(const char *output_type)
 117 {
 118         int ret = 0;
 119
 120         if (!strncasecmp("xml", output_type, 3)) {
 121                 ret = LTTNG_MI_XML;
 122         } else {
 123                 /* Invalid output format */
 124                 ERR("MI output format not supported");
 125                 ret = -LTTNG_ERR_MI_OUTPUT_TYPE;
 126         }
 127
 128         return ret;
 129 }
 130
 131 /*
 132  *  list_options
 133  *
 134  *  List options line by line. This is mostly for bash auto completion and to
 135  *  avoid difficult parsing.
 136  */
 137 static void list_options(FILE *ofp)
 138 {
 139         int i = 0;
 140         struct option *option = NULL;
 141
 142         option = &long_options[i];
 143         while (option->name != NULL) {
 144                 fprintf(ofp, "--%s\n", option->name);
 145
 146                 if (isprint(option->val)) {
 147                         fprintf(ofp, "-%c\n", option->val);
 148                 }
 149
 150                 i++;
 151                 option = &long_options[i];
 152         }
 153 }
 154
 155 /*
 156  * clean_exit
 157  */
 158 static void clean_exit(int code)
 159 {
 160         DBG("Clean exit");
 161         exit(code);
 162 }
 163
 164 /*
 165  *  sighandler
 166  *
 167  *  Signal handler for the daemon
 168  */
 169 static void sighandler(int sig)
 170 {
 171         switch (sig) {
 172                 case SIGTERM:
 173                         DBG("SIGTERM caught");
 174                         clean_exit(EXIT_FAILURE);
 175                         break;
 176                 default:
 177                         DBG("Unknown signal %d caught", sig);
 178                         break;
 179         }
 180
 181         return;
 182 }
 183
 184 /*
 185  *  set_signal_handler
 186  *
 187  *  Setup signal handler for SIGCHLD and SIGTERM.
 188  */
 189 static int set_signal_handler(void)
 190 {
 191         int ret = 0;
 192         struct sigaction sa;
 193         sigset_t sigset;
 194
 195         if ((ret = sigemptyset(&sigset)) < 0) {
 196                 PERROR("sigemptyset");
 197                 goto end;
 198         }
 199
 200         sa.sa_handler = sighandler;
 201         sa.sa_mask = sigset;
 202         sa.sa_flags = 0;
 203
 204         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 205                 PERROR("sigaction");
 206                 goto end;
 207         }
 208
 209 end:
 210         return ret;
 211 }
 212
 213 /*
 214  *  handle_command
 215  *
 216  *  Handle the full argv list of a first level command. Will find the command
 217  *  in the global commands array and call the function callback associated.
 218  *
 219  *  If command not found, return -1
 220  *  else, return function command error code.
 221  */
 222 static int handle_command(int argc, char **argv)
 223 {
 224         int i = 0, ret;
 225         struct cmd_struct *cmd;
 226
 227         if (*argv == NULL) {
 228                 ret = CMD_SUCCESS;
 229                 goto end;
 230         }
 231
 232         /* Special case for help command which needs the commands array */
 233         if (strcmp(argv[0], "help") == 0) {
 234                 ret = cmd_help(argc, (const char**) argv, commands);
 235                 goto end;
 236         }
 237
 238         cmd = &commands[i];
 239         while (cmd->name != NULL) {
 240                 /* Find command */
 241                 if (strcmp(argv[0], cmd->name) == 0) {
 242                         ret = cmd->func(argc, (const char**) argv);
 243                         goto end;
 244                 }
 245                 i++;
 246                 cmd = &commands[i];
 247         }
 248
 249         /* Command not found */
 250         ret = CMD_UNDEFINED;
 251
 252 end:
 253         return ret;
 254 }
 255
 256 static bool command_exists(const char *command)
 257 {
 258         const struct cmd_struct *cmd = commands;
 259         bool exists = false;
 260
 261         while (cmd->name != NULL) {
 262                 if (!strcmp(command, cmd->name)) {
 263                         exists = true;
 264                         goto end;
 265                 }
 266                 cmd++;
 267         }
 268
 269 end:
 270         return exists;
 271 }
 272
 273 static void show_basic_help(void)
 274 {
 275         puts("Usage: lttng [--group=GROUP] [--mi=TYPE] [--no-sessiond | --sessiond-path=PATH]");
 276         puts("             [--quiet | -v | -vv | -vvv] COMMAND [COMMAND OPTIONS]");
 277         puts("");
 278         puts("Available commands:");
 279         puts("");
 280         puts("Tracing sessions:");
 281         puts("  create            " CONFIG_CMD_DESCR_CREATE);
 282         puts("  destroy           " CONFIG_CMD_DESCR_DESTROY);
 283         puts("  load              " CONFIG_CMD_DESCR_LOAD);
 284         puts("  regenerate        " CONFIG_CMD_DESCR_REGENERATE);
 285         puts("  save              " CONFIG_CMD_DESCR_SAVE);
 286         puts("  set-session       " CONFIG_CMD_DESCR_SET_SESSION);
 287         puts("");
 288         puts("Channels:");
 289         puts("  add-context       " CONFIG_CMD_DESCR_ADD_CONTEXT);
 290         puts("  disable-channel   " CONFIG_CMD_DESCR_DISABLE_CHANNEL);
 291         puts("  enable-channel    " CONFIG_CMD_DESCR_ENABLE_CHANNEL);
 292         puts("");
 293         puts("Event rules:");
 294         puts("  disable-event     " CONFIG_CMD_DESCR_DISABLE_EVENT);
 295         puts("  enable-event      " CONFIG_CMD_DESCR_ENABLE_EVENT);
 296         puts("");
 297         puts("Status:");
 298         puts("  list              " CONFIG_CMD_DESCR_LIST);
 299         puts("  status            " CONFIG_CMD_DESCR_STATUS);
 300         puts("");
 301         puts("Control:");
 302         puts("  snapshot          " CONFIG_CMD_DESCR_SNAPSHOT);
 303         puts("  start             " CONFIG_CMD_DESCR_START);
 304         puts("  stop              " CONFIG_CMD_DESCR_STOP);
 305         puts("");
 306         puts("Tracing session rotation:");
 307         puts("  disable-rotation  " CONFIG_CMD_DESCR_DISABLE_ROTATION);
 308         puts("  enable-rotation   " CONFIG_CMD_DESCR_ENABLE_ROTATION);
 309         puts("  rotate            " CONFIG_CMD_DESCR_ROTATE);
 310         puts("");
 311         puts("Resource tracking:");
 312         puts("  track             " CONFIG_CMD_DESCR_TRACK);
 313         puts("  untrack           " CONFIG_CMD_DESCR_UNTRACK);
 314         puts("");
 315         puts("Miscellaneous:");
 316         puts("  help              " CONFIG_CMD_DESCR_HELP);
 317         puts("  version           " CONFIG_CMD_DESCR_VERSION);
 318         puts("  view              " CONFIG_CMD_DESCR_VIEW);
 319         puts("");
 320         puts("Run `lttng help COMMAND` or `lttng COMMAND --help` to get help with");
 321         puts("command COMMAND.");
 322         puts("");
 323         puts("See `man lttng` for more help with the lttng command.");
 324 }
 325
 326 /*
 327  * Parse command line arguments.
 328  *
 329  * Return 0 if OK, else -1
 330  */
 331 static int parse_args(int argc, char **argv)
 332 {
 333         int opt, ret;
 334
 335         if (lttng_is_setuid_setgid()) {
 336                 ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.", argv[0]);
 337                 clean_exit(EXIT_FAILURE);
 338         }
 339
 340         if (argc < 2) {
 341                 show_basic_help();
 342                 clean_exit(EXIT_FAILURE);
 343         }
 344
 345         while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, NULL)) != -1) {
 346                 switch (opt) {
 347                 case 'V':
 348                         version(stdout);
 349                         ret = 0;
 350                         goto end;
 351                 case 'h':
 352                         ret = utils_show_help(1, "lttng", help_msg);
 353                         if (ret) {
 354                                 ERR("Cannot show --help for `lttng`");
 355                                 perror("exec");
 356                         }
 357                         goto end;
 358                 case 'v':
 359                         /* There is only 3 possible level of verbosity. (-vvv) */
 360                         if (lttng_opt_verbose < 3) {
 361                                 lttng_opt_verbose += 1;
 362                         }
 363                         break;
 364                 case 'q':
 365                         lttng_opt_quiet = 1;
 366                         break;
 367                 case 'm':
 368                         lttng_opt_mi = mi_output_type(optarg);
 369                         if (lttng_opt_mi < 0) {
 370                                 ret = lttng_opt_mi;
 371                                 goto error;
 372                         }
 373                         break;
 374                 case 'g':
 375                         lttng_set_tracing_group(optarg);
 376                         break;
 377                 case 'n':
 378                         opt_no_sessiond = 1;
 379                         break;
 380                 case OPT_SESSION_PATH:
 381                         free(opt_sessiond_path);
 382                         opt_sessiond_path = strdup(optarg);
 383                         if (!opt_sessiond_path) {
 384                                 ret = -1;
 385                                 goto error;
 386                         }
 387                         break;
 388                 case OPT_RELAYD_PATH:
 389                         free(opt_relayd_path);
 390                         opt_relayd_path = strdup(optarg);
 391                         if (!opt_relayd_path) {
 392                                 ret = -1;
 393                                 goto error;
 394                         }
 395                         break;
 396                 case OPT_DUMP_OPTIONS:
 397                         list_options(stdout);
 398                         ret = 0;
 399                         goto end;
 400                 case OPT_DUMP_COMMANDS:
 401                         list_commands(commands, stdout);
 402                         ret = 0;
 403                         goto end;
 404                 default:
 405                         ret = 1;
 406                         goto error;
 407                 }
 408         }
 409
 410         /* If both options are specified, quiet wins */
 411         if (lttng_opt_verbose && lttng_opt_quiet) {
 412                 lttng_opt_verbose = 0;
 413         }
 414
 415         /* No leftovers, quit */
 416         if ((argc - optind) == 0) {
 417                 ret = 1;
 418                 goto error;
 419         }
 420
 421         /*
 422          * Handle leftovers which is a first level command with the trailing
 423          * options.
 424          */
 425         ret = handle_command(argc - optind, argv + optind);
 426         switch (ret) {
 427         case CMD_WARNING:
 428         case CMD_ERROR:
 429                 break;
 430         case CMD_UNDEFINED:
 431                 if (!command_exists(*(argv + optind))) {
 432                         MSG("lttng: %s is not an lttng command. See 'lttng --help'.",
 433                                         *(argv + optind));
 434                 } else {
 435                         ERR("Unrecognized argument used with \'%s\' command",
 436                                         *(argv + optind));
 437                 }
 438                 break;
 439         case CMD_FATAL:
 440         case CMD_UNSUPPORTED:
 441                 break;
 442         case -1:
 443                 ret = 1;
 444                 break;
 445         case 0:
 446                 break;
 447         default:
 448                 if (ret < 0) {
 449                         ret = -ret;
 450                 }
 451                 break;
 452         }
 453
 454 end:
 455 error:
 456         return ret;
 457 }
 458
 459
 460 /*
 461  *  main
 462  */
 463 int main(int argc, char *argv[])
 464 {
 465         int ret;
 466
 467         progname = argv[0] ? argv[0] : "lttng";
 468
 469         ret = set_signal_handler();
 470         if (ret < 0) {
 471                 clean_exit(ret);
 472         }
 473
 474         ret = parse_args(argc, argv);
 475         if (ret != 0) {
 476                 clean_exit(ret);
 477         }
 478
 479         return 0;
 480 }