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%s\n",
 109                         progname,
 110                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION,
 111                         EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " EXTRA_VERSION_NAME);
 112 }
 113
 114 /*
 115  * Find the MI output type enum from a string. This function is for the support
 116  * of machine interface output.
 117  */
 118 static int mi_output_type(const char *output_type)
 119 {
 120         int ret = 0;
 121
 122         if (!strncasecmp("xml", output_type, 3)) {
 123                 ret = LTTNG_MI_XML;
 124         } else {
 125                 /* Invalid output format */
 126                 ERR("MI output format not supported");
 127                 ret = -LTTNG_ERR_MI_OUTPUT_TYPE;
 128         }
 129
 130         return ret;
 131 }
 132
 133 /*
 134  *  list_options
 135  *
 136  *  List options line by line. This is mostly for bash auto completion and to
 137  *  avoid difficult parsing.
 138  */
 139 static void list_options(FILE *ofp)
 140 {
 141         int i = 0;
 142         struct option *option = NULL;
 143
 144         option = &long_options[i];
 145         while (option->name != NULL) {
 146                 fprintf(ofp, "--%s\n", option->name);
 147
 148                 if (isprint(option->val)) {
 149                         fprintf(ofp, "-%c\n", option->val);
 150                 }
 151
 152                 i++;
 153                 option = &long_options[i];
 154         }
 155 }
 156
 157 /*
 158  * clean_exit
 159  */
 160 static void clean_exit(int code)
 161 {
 162         DBG("Clean exit");
 163         exit(code);
 164 }
 165
 166 /*
 167  *  sighandler
 168  *
 169  *  Signal handler for the daemon
 170  */
 171 static void sighandler(int sig)
 172 {
 173         switch (sig) {
 174                 case SIGTERM:
 175                         DBG("SIGTERM caught");
 176                         clean_exit(EXIT_FAILURE);
 177                         break;
 178                 default:
 179                         DBG("Unknown signal %d caught", sig);
 180                         break;
 181         }
 182
 183         return;
 184 }
 185
 186 /*
 187  *  set_signal_handler
 188  *
 189  *  Setup signal handler for SIGCHLD and SIGTERM.
 190  */
 191 static int set_signal_handler(void)
 192 {
 193         int ret = 0;
 194         struct sigaction sa;
 195         sigset_t sigset;
 196
 197         if ((ret = sigemptyset(&sigset)) < 0) {
 198                 PERROR("sigemptyset");
 199                 goto end;
 200         }
 201
 202         sa.sa_handler = sighandler;
 203         sa.sa_mask = sigset;
 204         sa.sa_flags = 0;
 205
 206         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 207                 PERROR("sigaction");
 208                 goto end;
 209         }
 210
 211 end:
 212         return ret;
 213 }
 214
 215 /*
 216  *  handle_command
 217  *
 218  *  Handle the full argv list of a first level command. Will find the command
 219  *  in the global commands array and call the function callback associated.
 220  *
 221  *  If command not found, return -1
 222  *  else, return function command error code.
 223  */
 224 static int handle_command(int argc, char **argv)
 225 {
 226         int i = 0, ret;
 227         struct cmd_struct *cmd;
 228
 229         if (*argv == NULL) {
 230                 ret = CMD_SUCCESS;
 231                 goto end;
 232         }
 233
 234         /* Special case for help command which needs the commands array */
 235         if (strcmp(argv[0], "help") == 0) {
 236                 ret = cmd_help(argc, (const char**) argv, commands);
 237                 goto end;
 238         }
 239
 240         cmd = &commands[i];
 241         while (cmd->name != NULL) {
 242                 /* Find command */
 243                 if (strcmp(argv[0], cmd->name) == 0) {
 244                         ret = cmd->func(argc, (const char**) argv);
 245                         goto end;
 246                 }
 247                 i++;
 248                 cmd = &commands[i];
 249         }
 250
 251         /* Command not found */
 252         ret = CMD_UNDEFINED;
 253
 254 end:
 255         return ret;
 256 }
 257
 258 static bool command_exists(const char *command)
 259 {
 260         const struct cmd_struct *cmd = commands;
 261         bool exists = false;
 262
 263         while (cmd->name != NULL) {
 264                 if (!strcmp(command, cmd->name)) {
 265                         exists = true;
 266                         goto end;
 267                 }
 268                 cmd++;
 269         }
 270
 271 end:
 272         return exists;
 273 }
 274
 275 static void show_basic_help(void)
 276 {
 277         puts("Usage: lttng [--group=GROUP] [--mi=TYPE] [--no-sessiond | --sessiond-path=PATH]");
 278         puts("             [--quiet | -v | -vv | -vvv] COMMAND [COMMAND OPTIONS]");
 279         puts("");
 280         puts("Available commands:");
 281         puts("");
 282         puts("Tracing sessions:");
 283         puts("  create            " CONFIG_CMD_DESCR_CREATE);
 284         puts("  clear             " CONFIG_CMD_DESCR_CLEAR);
 285         puts("  destroy           " CONFIG_CMD_DESCR_DESTROY);
 286         puts("  load              " CONFIG_CMD_DESCR_LOAD);
 287         puts("  regenerate        " CONFIG_CMD_DESCR_REGENERATE);
 288         puts("  save              " CONFIG_CMD_DESCR_SAVE);
 289         puts("  set-session       " CONFIG_CMD_DESCR_SET_SESSION);
 290         puts("");
 291         puts("Channels:");
 292         puts("  add-context       " CONFIG_CMD_DESCR_ADD_CONTEXT);
 293         puts("  disable-channel   " CONFIG_CMD_DESCR_DISABLE_CHANNEL);
 294         puts("  enable-channel    " CONFIG_CMD_DESCR_ENABLE_CHANNEL);
 295         puts("");
 296         puts("Event rules:");
 297         puts("  disable-event     " CONFIG_CMD_DESCR_DISABLE_EVENT);
 298         puts("  enable-event      " CONFIG_CMD_DESCR_ENABLE_EVENT);
 299         puts("");
 300         puts("Status:");
 301         puts("  list              " CONFIG_CMD_DESCR_LIST);
 302         puts("  status            " CONFIG_CMD_DESCR_STATUS);
 303         puts("");
 304         puts("Control:");
 305         puts("  snapshot          " CONFIG_CMD_DESCR_SNAPSHOT);
 306         puts("  start             " CONFIG_CMD_DESCR_START);
 307         puts("  stop              " CONFIG_CMD_DESCR_STOP);
 308         puts("");
 309         puts("Tracing session rotation:");
 310         puts("  disable-rotation  " CONFIG_CMD_DESCR_DISABLE_ROTATION);
 311         puts("  enable-rotation   " CONFIG_CMD_DESCR_ENABLE_ROTATION);
 312         puts("  rotate            " CONFIG_CMD_DESCR_ROTATE);
 313         puts("");
 314         puts("Resource tracking:");
 315         puts("  track             " CONFIG_CMD_DESCR_TRACK);
 316         puts("  untrack           " CONFIG_CMD_DESCR_UNTRACK);
 317         puts("");
 318         puts("Miscellaneous:");
 319         puts("  help              " CONFIG_CMD_DESCR_HELP);
 320         puts("  version           " CONFIG_CMD_DESCR_VERSION);
 321         puts("  view              " CONFIG_CMD_DESCR_VIEW);
 322         puts("");
 323         puts("Run `lttng help COMMAND` or `lttng COMMAND --help` to get help with");
 324         puts("command COMMAND.");
 325         puts("");
 326         puts("See `man lttng` for more help with the lttng command.");
 327 }
 328
 329 /*
 330  * Parse command line arguments.
 331  *
 332  * Return 0 if OK, else -1
 333  */
 334 static int parse_args(int argc, char **argv)
 335 {
 336         int opt, ret;
 337
 338         if (lttng_is_setuid_setgid()) {
 339                 ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.", argv[0]);
 340                 clean_exit(EXIT_FAILURE);
 341         }
 342
 343         if (argc < 2) {
 344                 show_basic_help();
 345                 clean_exit(EXIT_FAILURE);
 346         }
 347
 348         while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, NULL)) != -1) {
 349                 switch (opt) {
 350                 case 'V':
 351                         version(stdout);
 352                         ret = 0;
 353                         goto end;
 354                 case 'h':
 355                         ret = utils_show_help(1, "lttng", help_msg);
 356                         if (ret) {
 357                                 ERR("Cannot show --help for `lttng`");
 358                                 perror("exec");
 359                         }
 360                         goto end;
 361                 case 'v':
 362                         /* There is only 3 possible level of verbosity. (-vvv) */
 363                         if (lttng_opt_verbose < 3) {
 364                                 lttng_opt_verbose += 1;
 365                         }
 366                         break;
 367                 case 'q':
 368                         lttng_opt_quiet = 1;
 369                         break;
 370                 case 'm':
 371                         lttng_opt_mi = mi_output_type(optarg);
 372                         if (lttng_opt_mi < 0) {
 373                                 ret = lttng_opt_mi;
 374                                 goto error;
 375                         }
 376                         break;
 377                 case 'g':
 378                         lttng_set_tracing_group(optarg);
 379                         break;
 380                 case 'n':
 381                         opt_no_sessiond = 1;
 382                         break;
 383                 case OPT_SESSION_PATH:
 384                         free(opt_sessiond_path);
 385                         opt_sessiond_path = strdup(optarg);
 386                         if (!opt_sessiond_path) {
 387                                 ret = -1;
 388                                 goto error;
 389                         }
 390                         break;
 391                 case OPT_RELAYD_PATH:
 392                         free(opt_relayd_path);
 393                         opt_relayd_path = strdup(optarg);
 394                         if (!opt_relayd_path) {
 395                                 ret = -1;
 396                                 goto error;
 397                         }
 398                         break;
 399                 case OPT_DUMP_OPTIONS:
 400                         list_options(stdout);
 401                         ret = 0;
 402                         goto end;
 403                 case OPT_DUMP_COMMANDS:
 404                         list_commands(commands, stdout);
 405                         ret = 0;
 406                         goto end;
 407                 default:
 408                         ret = 1;
 409                         goto error;
 410                 }
 411         }
 412
 413         /* If both options are specified, quiet wins */
 414         if (lttng_opt_verbose && lttng_opt_quiet) {
 415                 lttng_opt_verbose = 0;
 416         }
 417
 418         /* No leftovers, quit */
 419         if ((argc - optind) == 0) {
 420                 ret = 1;
 421                 goto error;
 422         }
 423
 424         /*
 425          * Handle leftovers which is a first level command with the trailing
 426          * options.
 427          */
 428         ret = handle_command(argc - optind, argv + optind);
 429         switch (ret) {
 430         case CMD_WARNING:
 431         case CMD_ERROR:
 432                 break;
 433         case CMD_UNDEFINED:
 434                 if (!command_exists(*(argv + optind))) {
 435                         MSG("lttng: %s is not an lttng command. See 'lttng --help'.",
 436                                         *(argv + optind));
 437                 } else {
 438                         ERR("Unrecognized argument used with \'%s\' command",
 439                                         *(argv + optind));
 440                 }
 441                 break;
 442         case CMD_FATAL:
 443         case CMD_UNSUPPORTED:
 444                 break;
 445         case -1:
 446                 ret = 1;
 447                 break;
 448         case 0:
 449                 break;
 450         default:
 451                 if (ret < 0) {
 452                         ret = -ret;
 453                 }
 454                 break;
 455         }
 456
 457 end:
 458 error:
 459         return ret;
 460 }
 461
 462
 463 /*
 464  *  main
 465  */
 466 int main(int argc, char *argv[])
 467 {
 468         int ret;
 469
 470         progname = argv[0] ? argv[0] : "lttng";
 471
 472         ret = set_signal_handler();
 473         if (ret < 0) {
 474                 clean_exit(ret);
 475         }
 476
 477         ret = parse_args(argc, argv);
 478         if (ret != 0) {
 479                 clean_exit(ret);
 480         }
 481
 482         return 0;
 483 }