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         { "list", cmd_list},
  69         { "status", cmd_status},
  70         { "create", cmd_create},
  71         { "destroy", cmd_destroy},
  72         { "start", cmd_start},
  73         { "stop", cmd_stop},
  74         { "enable-event", cmd_enable_events},
  75         { "disable-event", cmd_disable_events},
  76         { "enable-channel", cmd_enable_channels},
  77         { "disable-channel", cmd_disable_channels},
  78         { "add-context", cmd_add_context},
  79         { "set-session", cmd_set_session},
  80         { "version", cmd_version},
  81         { "calibrate", cmd_calibrate},
  82         { "view", cmd_view},
  83         { "snapshot", cmd_snapshot},
  84         { "save", cmd_save},
  85         { "load", cmd_load},
  86         { "track", cmd_track},
  87         { "untrack", cmd_untrack},
  88         { "metadata", cmd_metadata},
  89         { "help", NULL},
  90         { NULL, NULL}   /* Array closure */
  91 };
  92
  93 static void version(FILE *ofp)
  94 {
  95         fprintf(ofp, "%s (LTTng Trace Control) " VERSION" - " VERSION_NAME "%s\n",
  96                         progname,
  97                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION);
  98 }
  99
 100 /*
 101  * Find the MI output type enum from a string. This function is for the support
 102  * of machine interface output.
 103  */
 104 static int mi_output_type(const char *output_type)
 105 {
 106         int ret = 0;
 107
 108         if (!strncasecmp("xml", output_type, 3)) {
 109                 ret = LTTNG_MI_XML;
 110         } else {
 111                 /* Invalid output format */
 112                 ERR("MI output format not supported");
 113                 ret = -LTTNG_ERR_MI_OUTPUT_TYPE;
 114         }
 115
 116         return ret;
 117 }
 118
 119 /*
 120  *  list_options
 121  *
 122  *  List options line by line. This is mostly for bash auto completion and to
 123  *  avoid difficult parsing.
 124  */
 125 static void list_options(FILE *ofp)
 126 {
 127         int i = 0;
 128         struct option *option = NULL;
 129
 130         option = &long_options[i];
 131         while (option->name != NULL) {
 132                 fprintf(ofp, "--%s\n", option->name);
 133
 134                 if (isprint(option->val)) {
 135                         fprintf(ofp, "-%c\n", option->val);
 136                 }
 137
 138                 i++;
 139                 option = &long_options[i];
 140         }
 141 }
 142
 143 /*
 144  * clean_exit
 145  */
 146 static void clean_exit(int code)
 147 {
 148         DBG("Clean exit");
 149         exit(code);
 150 }
 151
 152 /*
 153  *  sighandler
 154  *
 155  *  Signal handler for the daemon
 156  */
 157 static void sighandler(int sig)
 158 {
 159         switch (sig) {
 160                 case SIGTERM:
 161                         DBG("SIGTERM caught");
 162                         clean_exit(EXIT_FAILURE);
 163                         break;
 164                 default:
 165                         DBG("Unknown signal %d caught", sig);
 166                         break;
 167         }
 168
 169         return;
 170 }
 171
 172 /*
 173  *  set_signal_handler
 174  *
 175  *  Setup signal handler for SIGCHLD and SIGTERM.
 176  */
 177 static int set_signal_handler(void)
 178 {
 179         int ret = 0;
 180         struct sigaction sa;
 181         sigset_t sigset;
 182
 183         if ((ret = sigemptyset(&sigset)) < 0) {
 184                 PERROR("sigemptyset");
 185                 goto end;
 186         }
 187
 188         sa.sa_handler = sighandler;
 189         sa.sa_mask = sigset;
 190         sa.sa_flags = 0;
 191
 192         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 193                 PERROR("sigaction");
 194                 goto end;
 195         }
 196
 197 end:
 198         return ret;
 199 }
 200
 201 /*
 202  *  handle_command
 203  *
 204  *  Handle the full argv list of a first level command. Will find the command
 205  *  in the global commands array and call the function callback associated.
 206  *
 207  *  If command not found, return -1
 208  *  else, return function command error code.
 209  */
 210 static int handle_command(int argc, char **argv)
 211 {
 212         int i = 0, ret;
 213         struct cmd_struct *cmd;
 214
 215         if (*argv == NULL) {
 216                 ret = CMD_SUCCESS;
 217                 goto end;
 218         }
 219
 220         /* Special case for help command which needs the commands array */
 221         if (strcmp(argv[0], "help") == 0) {
 222                 ret = cmd_help(argc, (const char**) argv, commands);
 223                 goto end;
 224         }
 225
 226         cmd = &commands[i];
 227         while (cmd->name != NULL) {
 228                 /* Find command */
 229                 if (strcmp(argv[0], cmd->name) == 0) {
 230                         ret = cmd->func(argc, (const char**) argv);
 231                         goto end;
 232                 }
 233                 i++;
 234                 cmd = &commands[i];
 235         }
 236
 237         /* Command not found */
 238         ret = CMD_UNDEFINED;
 239
 240 end:
 241         return ret;
 242 }
 243
 244 /*
 245  * Parse command line arguments.
 246  *
 247  * Return 0 if OK, else -1
 248  */
 249 static int parse_args(int argc, char **argv)
 250 {
 251         int opt, ret;
 252         char *user;
 253
 254         if (lttng_is_setuid_setgid()) {
 255                 ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.", argv[0]);
 256                 clean_exit(EXIT_FAILURE);
 257         }
 258
 259         if (argc < 2) {
 260                 clean_exit(EXIT_FAILURE);
 261         }
 262
 263         while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, NULL)) != -1) {
 264                 switch (opt) {
 265                 case 'V':
 266                         version(stdout);
 267                         ret = 0;
 268                         goto end;
 269                 case 'h':
 270                         ret = utils_show_man_page(1, "lttng");
 271
 272                         if (ret) {
 273                                 ERR("Cannot view man page lttng(1)");
 274                                 perror("exec");
 275                         }
 276                         goto end;
 277                 case 'v':
 278                         /* There is only 3 possible level of verbosity. (-vvv) */
 279                         if (lttng_opt_verbose < 3) {
 280                                 lttng_opt_verbose += 1;
 281                         }
 282                         break;
 283                 case 'q':
 284                         lttng_opt_quiet = 1;
 285                         break;
 286                 case 'm':
 287                         lttng_opt_mi = mi_output_type(optarg);
 288                         if (lttng_opt_mi < 0) {
 289                                 ret = lttng_opt_mi;
 290                                 goto error;
 291                         }
 292                         break;
 293                 case 'g':
 294                         lttng_set_tracing_group(optarg);
 295                         break;
 296                 case 'n':
 297                         opt_no_sessiond = 1;
 298                         break;
 299                 case OPT_SESSION_PATH:
 300                         opt_sessiond_path = strdup(optarg);
 301                         if (!opt_sessiond_path) {
 302                                 ret = -1;
 303                                 goto error;
 304                         }
 305                         break;
 306                 case OPT_RELAYD_PATH:
 307                         opt_relayd_path = strdup(optarg);
 308                         if (!opt_relayd_path) {
 309                                 ret = -1;
 310                                 goto error;
 311                         }
 312                         break;
 313                 case OPT_DUMP_OPTIONS:
 314                         list_options(stdout);
 315                         ret = 0;
 316                         goto end;
 317                 case OPT_DUMP_COMMANDS:
 318                         list_commands(commands, stdout);
 319                         ret = 0;
 320                         goto end;
 321                 default:
 322                         ret = 1;
 323                         goto error;
 324                 }
 325         }
 326
 327         /* If both options are specified, quiet wins */
 328         if (lttng_opt_verbose && lttng_opt_quiet) {
 329                 lttng_opt_verbose = 0;
 330         }
 331
 332         /* No leftovers, quit */
 333         if ((argc - optind) == 0) {
 334                 ret = 1;
 335                 goto error;
 336         }
 337
 338         /* For Mathieu Desnoyers a.k.a. Dr. Tracing */
 339         user = getenv("USER");
 340         if (user != NULL && ((strncmp(progname, "drtrace", 7) == 0 ||
 341                                         strncmp("compudj", user, 7) == 0))) {
 342                 MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n", 27,1,33,27,0);
 343         }
 344         /* Thanks Mathieu */
 345
 346         /*
 347          * Handle leftovers which is a first level command with the trailing
 348          * options.
 349          */
 350         ret = handle_command(argc - optind, argv + optind);
 351         switch (ret) {
 352         case CMD_WARNING:
 353                 WARN("Some command(s) went wrong");
 354                 break;
 355         case CMD_ERROR:
 356                 ERR("Command error");
 357                 break;
 358         case CMD_UNDEFINED:
 359                 ERR("Undefined command or invalid arguments");
 360                 break;
 361         case CMD_FATAL:
 362                 ERR("Fatal error");
 363                 break;
 364         case CMD_UNSUPPORTED:
 365                 ERR("Unsupported command");
 366                 break;
 367         case -1:
 368                 ret = 1;
 369                 break;
 370         case 0:
 371                 break;
 372         default:
 373                 if (ret < 0) {
 374                         ret = -ret;
 375                 }
 376                 break;
 377         }
 378
 379 end:
 380 error:
 381         return ret;
 382 }
 383
 384
 385 /*
 386  *  main
 387  */
 388 int main(int argc, char *argv[])
 389 {
 390         int ret;
 391
 392         progname = argv[0] ? argv[0] : "lttng";
 393
 394         ret = set_signal_handler();
 395         if (ret < 0) {
 396                 clean_exit(ret);
 397         }
 398
 399         ret = parse_args(argc, argv);
 400         if (ret != 0) {
 401                 clean_exit(ret);
 402         }
 403
 404         return 0;
 405 }