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 _GNU_SOURCE
  19 #define _LGPL_SOURCE
  20 #include <getopt.h>
  21 #include <signal.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/types.h>
  26 #include <sys/wait.h>
  27 #include <unistd.h>
  28 #include <config.h>
  29 #include <ctype.h>
  30
  31 #include <lttng/lttng.h>
  32 #include <common/error.h>
  33 #include <common/compat/getenv.h>
  34
  35 #include "command.h"
  36
  37 /* Variables */
  38 static char *progname;
  39 int opt_no_sessiond;
  40 char *opt_sessiond_path;
  41
  42 char *opt_relayd_path;
  43
  44 enum {
  45         OPT_RELAYD_PATH,
  46         OPT_SESSION_PATH,
  47         OPT_DUMP_OPTIONS,
  48         OPT_DUMP_COMMANDS,
  49 };
  50
  51 /* Getopt options. No first level command. */
  52 static struct option long_options[] = {
  53         {"version",          0, NULL, 'V'},
  54         {"help",             0, NULL, 'h'},
  55         {"group",            1, NULL, 'g'},
  56         {"verbose",          0, NULL, 'v'},
  57         {"quiet",            0, NULL, 'q'},
  58         {"mi",               1, NULL, 'm'},
  59         {"no-sessiond",      0, NULL, 'n'},
  60         {"sessiond-path",    1, NULL, OPT_SESSION_PATH},
  61         {"relayd-path",      1, NULL, OPT_RELAYD_PATH},
  62         {"list-options",     0, NULL, OPT_DUMP_OPTIONS},
  63         {"list-commands",    0, NULL, OPT_DUMP_COMMANDS},
  64         {NULL, 0, NULL, 0}
  65 };
  66
  67 /* First level command */
  68 static struct cmd_struct commands[] =  {
  69         { "list", cmd_list},
  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         { NULL, NULL}   /* Array closure */
  89 };
  90
  91 static void usage(FILE *ofp)
  92 {
  93         fprintf(ofp, "LTTng Trace Control " VERSION " - " VERSION_NAME "%s\n\n",
  94                 GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION);
  95         fprintf(ofp, "usage: lttng [OPTIONS] <COMMAND> [<ARGS>]\n");
  96         fprintf(ofp, "\n");
  97         fprintf(ofp, "Options:\n");
  98         fprintf(ofp, "  -V, --version              Show version\n");
  99         fprintf(ofp, "  -h, --help                 Show this help\n");
 100         fprintf(ofp, "      --list-options         Simple listing of lttng options\n");
 101         fprintf(ofp, "      --list-commands        Simple listing of lttng commands\n");
 102         fprintf(ofp, "  -v, --verbose              Increase verbosity\n");
 103         fprintf(ofp, "  -q, --quiet                Quiet mode\n");
 104         fprintf(ofp, "  -m, --mi TYPE              Machine Interface mode.\n");
 105         fprintf(ofp, "                                 Type: xml\n");
 106         fprintf(ofp, "  -g, --group NAME           Unix tracing group name. (default: tracing)\n");
 107         fprintf(ofp, "  -n, --no-sessiond          Don't spawn a session daemon\n");
 108         fprintf(ofp, "      --sessiond-path PATH   Session daemon full path\n");
 109         fprintf(ofp, "      --relayd-path PATH     Relayd daemon full path\n");
 110         fprintf(ofp, "\n");
 111         fprintf(ofp, "Commands:\n");
 112         fprintf(ofp, "    add-context       Add context to event and/or channel\n");
 113         fprintf(ofp, "    calibrate         Quantify LTTng overhead\n");
 114         fprintf(ofp, "    create            Create tracing session\n");
 115         fprintf(ofp, "    destroy           Tear down tracing session\n");
 116         fprintf(ofp, "    enable-channel    Enable tracing channel\n");
 117         fprintf(ofp, "    enable-event      Enable tracing event\n");
 118         fprintf(ofp, "    disable-channel   Disable tracing channel\n");
 119         fprintf(ofp, "    disable-event     Disable tracing event\n");
 120         fprintf(ofp, "    list              List possible tracing options\n");
 121         fprintf(ofp, "    set-session       Set current session name\n");
 122         fprintf(ofp, "    snapshot          Snapshot buffers of current session name\n");
 123         fprintf(ofp, "    start             Start tracing\n");
 124         fprintf(ofp, "    stop              Stop tracing\n");
 125         fprintf(ofp, "    version           Show version information\n");
 126         fprintf(ofp, "    view              Start trace viewer\n");
 127         fprintf(ofp, "    save              Save session configuration\n");
 128         fprintf(ofp, "    load              Load session configuration\n");
 129         fprintf(ofp, "    track             Track specific system resources\n");
 130         fprintf(ofp, "    untrack           Untrack specific system resources\n");
 131         fprintf(ofp, "\n");
 132         fprintf(ofp, "Each command also has its own -h, --help option.\n");
 133         fprintf(ofp, "\n");
 134         fprintf(ofp, "Please see the lttng(1) man page for full documentation.\n");
 135         fprintf(ofp, "See http://lttng.org for updates, bug reports and news.\n");
 136 }
 137
 138 static void version(FILE *ofp)
 139 {
 140         fprintf(ofp, "%s (LTTng Trace Control) " VERSION" - " VERSION_NAME "%s\n",
 141                         progname,
 142                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION);
 143 }
 144
 145 /*
 146  * Find the MI output type enum from a string. This function is for the support
 147  * of machine interface output.
 148  */
 149 static int mi_output_type(const char *output_type)
 150 {
 151         int ret = 0;
 152
 153         if (!strncasecmp("xml", output_type, 3)) {
 154                 ret = LTTNG_MI_XML;
 155         } else {
 156                 /* Invalid output format */
 157                 ERR("MI output format not supported");
 158                 ret = -LTTNG_ERR_MI_OUTPUT_TYPE;
 159         }
 160
 161         return ret;
 162 }
 163
 164 /*
 165  *  list_options
 166  *
 167  *  List options line by line. This is mostly for bash auto completion and to
 168  *  avoid difficult parsing.
 169  */
 170 static void list_options(FILE *ofp)
 171 {
 172         int i = 0;
 173         struct option *option = NULL;
 174
 175         option = &long_options[i];
 176         while (option->name != NULL) {
 177                 fprintf(ofp, "--%s\n", option->name);
 178
 179                 if (isprint(option->val)) {
 180                         fprintf(ofp, "-%c\n", option->val);
 181                 }
 182
 183                 i++;
 184                 option = &long_options[i];
 185         }
 186 }
 187
 188 /*
 189  * clean_exit
 190  */
 191 static void clean_exit(int code)
 192 {
 193         DBG("Clean exit");
 194         exit(code);
 195 }
 196
 197 /*
 198  *  sighandler
 199  *
 200  *  Signal handler for the daemon
 201  */
 202 static void sighandler(int sig)
 203 {
 204         switch (sig) {
 205                 case SIGTERM:
 206                         DBG("SIGTERM caught");
 207                         clean_exit(EXIT_FAILURE);
 208                         break;
 209                 default:
 210                         DBG("Unknown signal %d caught", sig);
 211                         break;
 212         }
 213
 214         return;
 215 }
 216
 217 /*
 218  *  set_signal_handler
 219  *
 220  *  Setup signal handler for SIGCHLD and SIGTERM.
 221  */
 222 static int set_signal_handler(void)
 223 {
 224         int ret = 0;
 225         struct sigaction sa;
 226         sigset_t sigset;
 227
 228         if ((ret = sigemptyset(&sigset)) < 0) {
 229                 PERROR("sigemptyset");
 230                 goto end;
 231         }
 232
 233         sa.sa_handler = sighandler;
 234         sa.sa_mask = sigset;
 235         sa.sa_flags = 0;
 236
 237         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 238                 PERROR("sigaction");
 239                 goto end;
 240         }
 241
 242 end:
 243         return ret;
 244 }
 245
 246 /*
 247  *  handle_command
 248  *
 249  *  Handle the full argv list of a first level command. Will find the command
 250  *  in the global commands array and call the function callback associated.
 251  *
 252  *  If command not found, return -1
 253  *  else, return function command error code.
 254  */
 255 static int handle_command(int argc, char **argv)
 256 {
 257         int i = 0, ret;
 258         struct cmd_struct *cmd;
 259
 260         if (*argv == NULL) {
 261                 ret = CMD_SUCCESS;
 262                 goto end;
 263         }
 264
 265         cmd = &commands[i];
 266         while (cmd->func != NULL) {
 267                 /* Find command */
 268                 if (strcmp(argv[0], cmd->name) == 0) {
 269                         ret = cmd->func(argc, (const char**) argv);
 270                         goto end;
 271                 }
 272                 i++;
 273                 cmd = &commands[i];
 274         }
 275
 276         /* Command not found */
 277         ret = CMD_UNDEFINED;
 278
 279 end:
 280         return ret;
 281 }
 282
 283 /*
 284  * Parse command line arguments.
 285  *
 286  * Return 0 if OK, else -1
 287  */
 288 static int parse_args(int argc, char **argv)
 289 {
 290         int opt, ret;
 291         char *user;
 292
 293         if (lttng_is_setuid_setgid()) {
 294                 ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.", argv[0]);
 295                 clean_exit(EXIT_FAILURE);
 296         }
 297
 298         if (argc < 2) {
 299                 usage(stderr);
 300                 clean_exit(EXIT_FAILURE);
 301         }
 302
 303         while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, NULL)) != -1) {
 304                 switch (opt) {
 305                 case 'V':
 306                         version(stdout);
 307                         ret = 0;
 308                         goto end;
 309                 case 'h':
 310                         usage(stdout);
 311                         ret = 0;
 312                         goto end;
 313                 case 'v':
 314                         /* There is only 3 possible level of verbosity. (-vvv) */
 315                         if (lttng_opt_verbose < 3) {
 316                                 lttng_opt_verbose += 1;
 317                         }
 318                         break;
 319                 case 'q':
 320                         lttng_opt_quiet = 1;
 321                         break;
 322                 case 'm':
 323                         lttng_opt_mi = mi_output_type(optarg);
 324                         if (lttng_opt_mi < 0) {
 325                                 ret = lttng_opt_mi;
 326                                 goto error;
 327                         }
 328                         break;
 329                 case 'g':
 330                         lttng_set_tracing_group(optarg);
 331                         break;
 332                 case 'n':
 333                         opt_no_sessiond = 1;
 334                         break;
 335                 case OPT_SESSION_PATH:
 336                         opt_sessiond_path = strdup(optarg);
 337                         if (!opt_sessiond_path) {
 338                                 ret = -1;
 339                                 goto error;
 340                         }
 341                         break;
 342                 case OPT_RELAYD_PATH:
 343                         opt_relayd_path = strdup(optarg);
 344                         if (!opt_relayd_path) {
 345                                 ret = -1;
 346                                 goto error;
 347                         }
 348                         break;
 349                 case OPT_DUMP_OPTIONS:
 350                         list_options(stdout);
 351                         ret = 0;
 352                         goto end;
 353                 case OPT_DUMP_COMMANDS:
 354                         list_commands(commands, stdout);
 355                         ret = 0;
 356                         goto end;
 357                 default:
 358                         usage(stderr);
 359                         ret = 1;
 360                         goto error;
 361                 }
 362         }
 363
 364         /* If both options are specified, quiet wins */
 365         if (lttng_opt_verbose && lttng_opt_quiet) {
 366                 lttng_opt_verbose = 0;
 367         }
 368
 369         /* No leftovers, print usage and quit */
 370         if ((argc - optind) == 0) {
 371                 usage(stderr);
 372                 ret = 1;
 373                 goto error;
 374         }
 375
 376         /* For Mathieu Desnoyers a.k.a. Dr. Tracing */
 377         user = getenv("USER");
 378         if (user != NULL && ((strncmp(progname, "drtrace", 7) == 0 ||
 379                                         strncmp("compudj", user, 7) == 0))) {
 380                 MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n", 27,1,33,27,0);
 381         }
 382         /* Thanks Mathieu */
 383
 384         /*
 385          * Handle leftovers which is a first level command with the trailing
 386          * options.
 387          */
 388         ret = handle_command(argc - optind, argv + optind);
 389         switch (ret) {
 390         case CMD_WARNING:
 391                 WARN("Some command(s) went wrong");
 392                 break;
 393         case CMD_ERROR:
 394                 ERR("Command error");
 395                 break;
 396         case CMD_UNDEFINED:
 397                 ERR("Undefined command");
 398                 break;
 399         case CMD_FATAL:
 400                 ERR("Fatal error");
 401                 break;
 402         case CMD_UNSUPPORTED:
 403                 ERR("Unsupported command");
 404                 break;
 405         case -1:
 406                 usage(stderr);
 407                 ret = 1;
 408                 break;
 409         case 0:
 410                 break;
 411         default:
 412                 if (ret < 0) {
 413                         ret = -ret;
 414                 }
 415                 break;
 416         }
 417
 418 end:
 419 error:
 420         return ret;
 421 }
 422
 423
 424 /*
 425  *  main
 426  */
 427 int main(int argc, char *argv[])
 428 {
 429         int ret;
 430
 431         progname = argv[0] ? argv[0] : "lttng";
 432
 433         ret = set_signal_handler();
 434         if (ret < 0) {
 435                 clean_exit(ret);
 436         }
 437
 438         ret = parse_args(argc, argv);
 439         if (ret != 0) {
 440                 clean_exit(ret);
 441         }
 442
 443         return 0;
 444 }