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