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