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
  33 #include "command.h"
  34
  35 /* Variables */
  36 static char *progname;
  37 int opt_no_sessiond;
  38 char *opt_sessiond_path;
  39
  40 char *opt_relayd_path;
  41
  42 enum {
  43         OPT_RELAYD_PATH,
  44         OPT_SESSION_PATH,
  45         OPT_DUMP_OPTIONS,
  46         OPT_DUMP_COMMANDS,
  47 };
  48
  49 /* Getopt options. No first level command. */
  50 static struct option long_options[] = {
  51         {"version",          0, NULL, 'V'},
  52         {"help",             0, NULL, 'h'},
  53         {"group",            1, NULL, 'g'},
  54         {"verbose",          0, NULL, 'v'},
  55         {"quiet",            0, NULL, 'q'},
  56         {"mi",               1, NULL, 'm'},
  57         {"no-sessiond",      0, NULL, 'n'},
  58         {"sessiond-path",    1, NULL, OPT_SESSION_PATH},
  59         {"relayd-path",      1, NULL, OPT_RELAYD_PATH},
  60         {"list-options",     0, NULL, OPT_DUMP_OPTIONS},
  61         {"list-commands",    0, NULL, OPT_DUMP_COMMANDS},
  62         {NULL, 0, NULL, 0}
  63 };
  64
  65 /* First level command */
  66 static struct cmd_struct commands[] =  {
  67         { "list", cmd_list},
  68         { "create", cmd_create},
  69         { "destroy", cmd_destroy},
  70         { "start", cmd_start},
  71         { "stop", cmd_stop},
  72         { "enable-event", cmd_enable_events},
  73         { "disable-event", cmd_disable_events},
  74         { "enable-channel", cmd_enable_channels},
  75         { "disable-channel", cmd_disable_channels},
  76         { "add-context", cmd_add_context},
  77         { "set-session", cmd_set_session},
  78         { "version", cmd_version},
  79         { "calibrate", cmd_calibrate},
  80         { "view", cmd_view},
  81         { "snapshot", cmd_snapshot},
  82         { "save", cmd_save},
  83         { "load", cmd_load},
  84         { "track", cmd_track},
  85         { "untrack", cmd_untrack},
  86         { NULL, NULL}   /* Array closure */
  87 };
  88
  89 static void usage(FILE *ofp)
  90 {
  91         fprintf(ofp, "LTTng Trace Control " VERSION " - " VERSION_NAME "%s\n\n",
  92                 GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION);
  93         fprintf(ofp, "usage: lttng [OPTIONS] <COMMAND> [<ARGS>]\n");
  94         fprintf(ofp, "\n");
  95         fprintf(ofp, "Options:\n");
  96         fprintf(ofp, "  -V, --version              Show version\n");
  97         fprintf(ofp, "  -h, --help                 Show this help\n");
  98         fprintf(ofp, "      --list-options         Simple listing of lttng options\n");
  99         fprintf(ofp, "      --list-commands        Simple listing of lttng commands\n");
 100         fprintf(ofp, "  -v, --verbose              Increase verbosity\n");
 101         fprintf(ofp, "  -q, --quiet                Quiet mode\n");
 102         fprintf(ofp, "  -m, --mi TYPE              Machine Interface mode.\n");
 103         fprintf(ofp, "                                 Type: xml\n");
 104         fprintf(ofp, "  -g, --group NAME           Unix tracing group name. (default: tracing)\n");
 105         fprintf(ofp, "  -n, --no-sessiond          Don't spawn a session daemon\n");
 106         fprintf(ofp, "      --sessiond-path PATH   Session daemon full path\n");
 107         fprintf(ofp, "      --relayd-path PATH     Relayd daemon full path\n");
 108         fprintf(ofp, "\n");
 109         fprintf(ofp, "Commands:\n");
 110         fprintf(ofp, "    add-context       Add context to event and/or channel\n");
 111         fprintf(ofp, "    calibrate         Quantify LTTng overhead\n");
 112         fprintf(ofp, "    create            Create tracing session\n");
 113         fprintf(ofp, "    destroy           Tear down tracing session\n");
 114         fprintf(ofp, "    enable-channel    Enable tracing channel\n");
 115         fprintf(ofp, "    enable-event      Enable tracing event\n");
 116         fprintf(ofp, "    disable-channel   Disable tracing channel\n");
 117         fprintf(ofp, "    disable-event     Disable tracing event\n");
 118         fprintf(ofp, "    list              List possible tracing options\n");
 119         fprintf(ofp, "    set-session       Set current session name\n");
 120         fprintf(ofp, "    snapshot          Snapshot buffers of current session name\n");
 121         fprintf(ofp, "    start             Start tracing\n");
 122         fprintf(ofp, "    stop              Stop tracing\n");
 123         fprintf(ofp, "    version           Show version information\n");
 124         fprintf(ofp, "    view              Start trace viewer\n");
 125         fprintf(ofp, "    save              Save session configuration\n");
 126         fprintf(ofp, "    load              Load session configuration\n");
 127         fprintf(ofp, "    track             Track specific system resources\n");
 128         fprintf(ofp, "    untrack           Untrack specific system resources\n");
 129         fprintf(ofp, "\n");
 130         fprintf(ofp, "Each command also has its own -h, --help option.\n");
 131         fprintf(ofp, "\n");
 132         fprintf(ofp, "Please see the lttng(1) man page for full documentation.\n");
 133         fprintf(ofp, "See http://lttng.org for updates, bug reports and news.\n");
 134 }
 135
 136 static void version(FILE *ofp)
 137 {
 138         fprintf(ofp, "%s (LTTng Trace Control) " VERSION" - " VERSION_NAME "%s\n",
 139                         progname,
 140                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION);
 141 }
 142
 143 /*
 144  * Find the MI output type enum from a string. This function is for the support
 145  * of machine interface output.
 146  */
 147 static int mi_output_type(const char *output_type)
 148 {
 149         int ret = 0;
 150
 151         if (!strncasecmp("xml", output_type, 3)) {
 152                 ret = LTTNG_MI_XML;
 153         } else {
 154                 /* Invalid output format */
 155                 ERR("MI output format not supported");
 156                 ret = -LTTNG_ERR_MI_OUTPUT_TYPE;
 157         }
 158
 159         return ret;
 160 }
 161
 162 /*
 163  *  list_options
 164  *
 165  *  List options line by line. This is mostly for bash auto completion and to
 166  *  avoid difficult parsing.
 167  */
 168 static void list_options(FILE *ofp)
 169 {
 170         int i = 0;
 171         struct option *option = NULL;
 172
 173         option = &long_options[i];
 174         while (option->name != NULL) {
 175                 fprintf(ofp, "--%s\n", option->name);
 176
 177                 if (isprint(option->val)) {
 178                         fprintf(ofp, "-%c\n", option->val);
 179                 }
 180
 181                 i++;
 182                 option = &long_options[i];
 183         }
 184 }
 185
 186 /*
 187  * clean_exit
 188  */
 189 static void clean_exit(int code)
 190 {
 191         DBG("Clean exit");
 192         exit(code);
 193 }
 194
 195 /*
 196  *  sighandler
 197  *
 198  *  Signal handler for the daemon
 199  */
 200 static void sighandler(int sig)
 201 {
 202         switch (sig) {
 203                 case SIGTERM:
 204                         DBG("SIGTERM caught");
 205                         clean_exit(EXIT_FAILURE);
 206                         break;
 207                 default:
 208                         DBG("Unknown signal %d caught", sig);
 209                         break;
 210         }
 211
 212         return;
 213 }
 214
 215 /*
 216  *  set_signal_handler
 217  *
 218  *  Setup signal handler for SIGCHLD and SIGTERM.
 219  */
 220 static int set_signal_handler(void)
 221 {
 222         int ret = 0;
 223         struct sigaction sa;
 224         sigset_t sigset;
 225
 226         if ((ret = sigemptyset(&sigset)) < 0) {
 227                 PERROR("sigemptyset");
 228                 goto end;
 229         }
 230
 231         sa.sa_handler = sighandler;
 232         sa.sa_mask = sigset;
 233         sa.sa_flags = 0;
 234
 235         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 236                 PERROR("sigaction");
 237                 goto end;
 238         }
 239
 240 end:
 241         return ret;
 242 }
 243
 244 /*
 245  *  handle_command
 246  *
 247  *  Handle the full argv list of a first level command. Will find the command
 248  *  in the global commands array and call the function callback associated.
 249  *
 250  *  If command not found, return -1
 251  *  else, return function command error code.
 252  */
 253 static int handle_command(int argc, char **argv)
 254 {
 255         int i = 0, ret;
 256         struct cmd_struct *cmd;
 257
 258         if (*argv == NULL) {
 259                 ret = CMD_SUCCESS;
 260                 goto end;
 261         }
 262
 263         cmd = &commands[i];
 264         while (cmd->func != NULL) {
 265                 /* Find command */
 266                 if (strcmp(argv[0], cmd->name) == 0) {
 267                         ret = cmd->func(argc, (const char**) argv);
 268                         goto end;
 269                 }
 270                 i++;
 271                 cmd = &commands[i];
 272         }
 273
 274         /* Command not found */
 275         ret = CMD_UNDEFINED;
 276
 277 end:
 278         return ret;
 279 }
 280
 281 /*
 282  * Parse command line arguments.
 283  *
 284  * Return 0 if OK, else -1
 285  */
 286 static int parse_args(int argc, char **argv)
 287 {
 288         int opt, ret;
 289         char *user;
 290
 291         if (lttng_is_setuid_setgid()) {
 292                 ERR("'%s' is not allowed to be executed as a setuid/setgid binary for security reasons. Aborting.", argv[0]);
 293                 clean_exit(EXIT_FAILURE);
 294         }
 295
 296         if (argc < 2) {
 297                 usage(stderr);
 298                 clean_exit(EXIT_FAILURE);
 299         }
 300
 301         while ((opt = getopt_long(argc, argv, "+Vhnvqg:m:", long_options, NULL)) != -1) {
 302                 switch (opt) {
 303                 case 'V':
 304                         version(stdout);
 305                         ret = 0;
 306                         goto end;
 307                 case 'h':
 308                         usage(stdout);
 309                         ret = 0;
 310                         goto end;
 311                 case 'v':
 312                         /* There is only 3 possible level of verbosity. (-vvv) */
 313                         if (lttng_opt_verbose < 3) {
 314                                 lttng_opt_verbose += 1;
 315                         }
 316                         break;
 317                 case 'q':
 318                         lttng_opt_quiet = 1;
 319                         break;
 320                 case 'm':
 321                         lttng_opt_mi = mi_output_type(optarg);
 322                         if (lttng_opt_mi < 0) {
 323                                 ret = lttng_opt_mi;
 324                                 goto error;
 325                         }
 326                         break;
 327                 case 'g':
 328                         lttng_set_tracing_group(optarg);
 329                         break;
 330                 case 'n':
 331                         opt_no_sessiond = 1;
 332                         break;
 333                 case OPT_SESSION_PATH:
 334                         opt_sessiond_path = strdup(optarg);
 335                         if (!opt_sessiond_path) {
 336                                 ret = -1;
 337                                 goto error;
 338                         }
 339                         break;
 340                 case OPT_RELAYD_PATH:
 341                         opt_relayd_path = strdup(optarg);
 342                         if (!opt_relayd_path) {
 343                                 ret = -1;
 344                                 goto error;
 345                         }
 346                         break;
 347                 case OPT_DUMP_OPTIONS:
 348                         list_options(stdout);
 349                         ret = 0;
 350                         goto end;
 351                 case OPT_DUMP_COMMANDS:
 352                         list_commands(commands, stdout);
 353                         ret = 0;
 354                         goto end;
 355                 default:
 356                         usage(stderr);
 357                         ret = 1;
 358                         goto error;
 359                 }
 360         }
 361
 362         /* If both options are specified, quiet wins */
 363         if (lttng_opt_verbose && lttng_opt_quiet) {
 364                 lttng_opt_verbose = 0;
 365         }
 366
 367         /* No leftovers, print usage and quit */
 368         if ((argc - optind) == 0) {
 369                 usage(stderr);
 370                 ret = 1;
 371                 goto error;
 372         }
 373
 374         /* For Mathieu Desnoyers a.k.a. Dr. Tracing */
 375         user = getenv("USER");
 376         if (user != NULL && ((strncmp(progname, "drtrace", 7) == 0 ||
 377                                         strncmp("compudj", user, 7) == 0))) {
 378                 MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n", 27,1,33,27,0);
 379         }
 380         /* Thanks Mathieu */
 381
 382         /*
 383          * Handle leftovers which is a first level command with the trailing
 384          * options.
 385          */
 386         ret = handle_command(argc - optind, argv + optind);
 387         switch (ret) {
 388         case CMD_WARNING:
 389                 WARN("Some command(s) went wrong");
 390                 break;
 391         case CMD_ERROR:
 392                 ERR("Command error");
 393                 break;
 394         case CMD_UNDEFINED:
 395                 ERR("Undefined command");
 396                 break;
 397         case CMD_FATAL:
 398                 ERR("Fatal error");
 399                 break;
 400         case CMD_UNSUPPORTED:
 401                 ERR("Unsupported command");
 402                 break;
 403         case -1:
 404                 usage(stderr);
 405                 ret = 1;
 406                 break;
 407         case 0:
 408                 break;
 409         default:
 410                 if (ret < 0) {
 411                         ret = -ret;
 412                 }
 413                 break;
 414         }
 415
 416 end:
 417 error:
 418         return ret;
 419 }
 420
 421
 422 /*
 423  *  main
 424  */
 425 int main(int argc, char *argv[])
 426 {
 427         int ret;
 428
 429         progname = argv[0] ? argv[0] : "lttng";
 430
 431         ret = set_signal_handler();
 432         if (ret < 0) {
 433                 clean_exit(ret);
 434         }
 435
 436         ret = parse_args(argc, argv);
 437         if (ret != 0) {
 438                 clean_exit(ret);
 439         }
 440
 441         return 0;
 442 }