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