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