| 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 as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <getopt.h> |
| 21 | #include <signal.h> |
| 22 | #include <stdio.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <unistd.h> |
| 26 | |
| 27 | #include <lttng/lttng.h> |
| 28 | |
| 29 | #include "cmd.h" |
| 30 | #include "conf.h" |
| 31 | #include "lttngerr.h" |
| 32 | |
| 33 | /* Variables */ |
| 34 | static char *progname; |
| 35 | |
| 36 | int opt_quiet; |
| 37 | int opt_verbose; |
| 38 | static int opt_no_sessiond; |
| 39 | static char *opt_sessiond_path; |
| 40 | |
| 41 | enum { |
| 42 | OPT_NO_SESSIOND, |
| 43 | OPT_SESSION_PATH, |
| 44 | }; |
| 45 | |
| 46 | /* Getopt options. No first level command. */ |
| 47 | static struct option long_options[] = { |
| 48 | {"help", 0, NULL, 'h'}, |
| 49 | {"group", 1, NULL, 'g'}, |
| 50 | {"verbose", 0, NULL, 'v'}, |
| 51 | {"quiet", 0, NULL, 'q'}, |
| 52 | {"no-sessiond", 0, NULL, OPT_NO_SESSIOND}, |
| 53 | {"sessiond-path", 1, NULL, OPT_SESSION_PATH}, |
| 54 | {NULL, 0, NULL, 0} |
| 55 | }; |
| 56 | |
| 57 | /* First level command */ |
| 58 | static struct cmd_struct commands[] = { |
| 59 | { "list", cmd_list}, |
| 60 | { "create", cmd_create}, |
| 61 | { "destroy", cmd_destroy}, |
| 62 | { "add-channel", cmd_add_channel}, |
| 63 | { "start", cmd_start}, |
| 64 | { "stop", cmd_stop}, |
| 65 | { "enable-event", cmd_enable_events}, |
| 66 | { "disable-event", cmd_disable_events}, |
| 67 | { "enable-channel", cmd_enable_channels}, |
| 68 | { NULL, NULL} /* Array closure */ |
| 69 | }; |
| 70 | |
| 71 | static void usage(FILE *ofp) |
| 72 | { |
| 73 | fprintf(ofp, "LTTng Trace Control " VERSION"\n\n"); |
| 74 | fprintf(ofp, "usage: lttng [options] <command>\n"); |
| 75 | fprintf(ofp, "\n"); |
| 76 | fprintf(ofp, "Options:\n"); |
| 77 | fprintf(ofp, " -h, --help Show this help\n"); |
| 78 | fprintf(ofp, " -g, --group NAME Unix tracing group name. (default: tracing)\n"); |
| 79 | fprintf(ofp, " -v, --verbose Verbose mode\n"); |
| 80 | fprintf(ofp, " -q, --quiet Quiet mode\n"); |
| 81 | fprintf(ofp, " --no-sessiond Don't spawn a session daemon\n"); |
| 82 | fprintf(ofp, " --sessiond-path Session daemon full path\n"); |
| 83 | fprintf(ofp, "\n"); |
| 84 | fprintf(ofp, "Commands:\n"); |
| 85 | fprintf(ofp, " add-channel Add channel to tracer\n"); |
| 86 | fprintf(ofp, " create Create tracing session\n"); |
| 87 | fprintf(ofp, " destroy Teardown tracing session\n"); |
| 88 | fprintf(ofp, " enable-event Enable tracing event\n"); |
| 89 | fprintf(ofp, " enable-channel Enable tracing channel\n"); |
| 90 | fprintf(ofp, " disable-event Disable tracing event\n"); |
| 91 | fprintf(ofp, " list List possible tracing options\n"); |
| 92 | fprintf(ofp, " start Start tracing\n"); |
| 93 | fprintf(ofp, " stop Stop tracing\n"); |
| 94 | fprintf(ofp, " version Show version information\n"); |
| 95 | fprintf(ofp, "\n"); |
| 96 | fprintf(ofp, "Please see the lttng(1) man page for full documentation.\n"); |
| 97 | fprintf(ofp, "See http://lttng.org for updates, bug reports and news.\n"); |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * clean_exit |
| 102 | */ |
| 103 | static void clean_exit(int code) |
| 104 | { |
| 105 | DBG("Clean exit"); |
| 106 | exit(code); |
| 107 | } |
| 108 | |
| 109 | /* |
| 110 | * sighandler |
| 111 | * |
| 112 | * Signal handler for the daemon |
| 113 | */ |
| 114 | static void sighandler(int sig) |
| 115 | { |
| 116 | switch (sig) { |
| 117 | case SIGTERM: |
| 118 | DBG("SIGTERM catched"); |
| 119 | clean_exit(EXIT_FAILURE); |
| 120 | break; |
| 121 | case SIGCHLD: |
| 122 | /* Notify is done */ |
| 123 | DBG("SIGCHLD catched"); |
| 124 | break; |
| 125 | default: |
| 126 | DBG("Unknown signal %d catched", sig); |
| 127 | break; |
| 128 | } |
| 129 | |
| 130 | return; |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * set_signal_handler |
| 135 | * |
| 136 | * Setup signal handler for SIGCHLD and SIGTERM. |
| 137 | */ |
| 138 | static int set_signal_handler(void) |
| 139 | { |
| 140 | int ret = 0; |
| 141 | struct sigaction sa; |
| 142 | sigset_t sigset; |
| 143 | |
| 144 | if ((ret = sigemptyset(&sigset)) < 0) { |
| 145 | perror("sigemptyset"); |
| 146 | goto end; |
| 147 | } |
| 148 | |
| 149 | sa.sa_handler = sighandler; |
| 150 | sa.sa_mask = sigset; |
| 151 | sa.sa_flags = 0; |
| 152 | if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) { |
| 153 | perror("sigaction"); |
| 154 | goto end; |
| 155 | } |
| 156 | |
| 157 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { |
| 158 | perror("sigaction"); |
| 159 | goto end; |
| 160 | } |
| 161 | |
| 162 | end: |
| 163 | return ret; |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * handle_command |
| 168 | * |
| 169 | * Handle the full argv list of a first level command. Will find the command |
| 170 | * in the global commands array and call the function callback associated. |
| 171 | * |
| 172 | * If command not found, return -1 |
| 173 | * else, return function command error code. |
| 174 | */ |
| 175 | static int handle_command(int argc, char **argv) |
| 176 | { |
| 177 | int i = 0, ret; |
| 178 | struct cmd_struct *cmd; |
| 179 | |
| 180 | if (*argv == NULL) { |
| 181 | ret = CMD_SUCCESS; |
| 182 | goto end; |
| 183 | } |
| 184 | |
| 185 | cmd = &commands[i]; |
| 186 | while (cmd->func != NULL) { |
| 187 | /* Find command */ |
| 188 | if (strcmp(argv[0], cmd->name) == 0) { |
| 189 | ret = cmd->func(argc, (const char**) argv); |
| 190 | switch (ret) { |
| 191 | case CMD_ERROR: |
| 192 | ERR("Command error"); |
| 193 | break; |
| 194 | case CMD_NOT_IMPLEMENTED: |
| 195 | ERR("Options not implemented"); |
| 196 | break; |
| 197 | case CMD_UNDEFINED: |
| 198 | ERR("Undefined command"); |
| 199 | break; |
| 200 | case CMD_FATAL: |
| 201 | ERR("Fatal error"); |
| 202 | break; |
| 203 | } |
| 204 | goto end; |
| 205 | } |
| 206 | i++; |
| 207 | cmd = &commands[i]; |
| 208 | } |
| 209 | |
| 210 | /* Command not found */ |
| 211 | ret = -1; |
| 212 | |
| 213 | end: |
| 214 | return ret; |
| 215 | } |
| 216 | |
| 217 | /* |
| 218 | * spawn_sessiond |
| 219 | * |
| 220 | * Spawn a session daemon by forking and execv. |
| 221 | */ |
| 222 | static int spawn_sessiond(char *pathname) |
| 223 | { |
| 224 | int ret = 0; |
| 225 | pid_t pid; |
| 226 | |
| 227 | MSG("Spawning a session daemon"); |
| 228 | pid = fork(); |
| 229 | if (pid == 0) { |
| 230 | /* |
| 231 | * Spawn session daemon and tell |
| 232 | * it to signal us when ready. |
| 233 | */ |
| 234 | execlp(pathname, "ltt-sessiond", "--sig-parent", "--quiet", NULL); |
| 235 | /* execlp only returns if error happened */ |
| 236 | if (errno == ENOENT) { |
| 237 | ERR("No session daemon found. Use --sessiond-path."); |
| 238 | } else { |
| 239 | perror("execlp"); |
| 240 | } |
| 241 | kill(getppid(), SIGTERM); /* unpause parent */ |
| 242 | exit(EXIT_FAILURE); |
| 243 | } else if (pid > 0) { |
| 244 | /* Wait for ltt-sessiond to start */ |
| 245 | pause(); |
| 246 | goto end; |
| 247 | } else { |
| 248 | perror("fork"); |
| 249 | ret = -1; |
| 250 | goto end; |
| 251 | } |
| 252 | |
| 253 | end: |
| 254 | return ret; |
| 255 | } |
| 256 | |
| 257 | /* |
| 258 | * check_sessiond |
| 259 | * |
| 260 | * Check if the session daemon is available using |
| 261 | * the liblttngctl API for the check. If not, try to |
| 262 | * spawn a daemon. |
| 263 | */ |
| 264 | static int check_sessiond(void) |
| 265 | { |
| 266 | int ret; |
| 267 | char *pathname = NULL, *alloc_pathname = NULL; |
| 268 | |
| 269 | ret = lttng_session_daemon_alive(); |
| 270 | if (ret == 0) { /* not alive */ |
| 271 | /* Try command line option path */ |
| 272 | if (opt_sessiond_path != NULL) { |
| 273 | ret = access(opt_sessiond_path, F_OK | X_OK); |
| 274 | if (ret < 0) { |
| 275 | ERR("No such file: %s", opt_sessiond_path); |
| 276 | goto end; |
| 277 | } |
| 278 | pathname = opt_sessiond_path; |
| 279 | } else { |
| 280 | /* Try LTTNG_SESSIOND_PATH env variable */ |
| 281 | pathname = getenv(LTTNG_SESSIOND_PATH_ENV); |
| 282 | } |
| 283 | |
| 284 | /* Let's rock and roll */ |
| 285 | if (pathname == NULL) { |
| 286 | ret = asprintf(&alloc_pathname, "ltt-sessiond"); |
| 287 | if (ret < 0) { |
| 288 | goto end; |
| 289 | } |
| 290 | pathname = alloc_pathname; |
| 291 | } |
| 292 | |
| 293 | ret = spawn_sessiond(pathname); |
| 294 | free(alloc_pathname); |
| 295 | if (ret < 0) { |
| 296 | ERR("Problem occurs when starting %s", pathname); |
| 297 | goto end; |
| 298 | } |
| 299 | } |
| 300 | |
| 301 | end: |
| 302 | return ret; |
| 303 | } |
| 304 | |
| 305 | /* |
| 306 | * parse_args |
| 307 | * |
| 308 | * Parse command line arguments. |
| 309 | * Return 0 if OK, else -1 |
| 310 | */ |
| 311 | static int parse_args(int argc, char **argv) |
| 312 | { |
| 313 | int opt, ret; |
| 314 | |
| 315 | if (argc < 2) { |
| 316 | usage(stderr); |
| 317 | clean_exit(EXIT_FAILURE); |
| 318 | } |
| 319 | |
| 320 | while ((opt = getopt_long(argc, argv, "+hvqg:", long_options, NULL)) != -1) { |
| 321 | switch (opt) { |
| 322 | case 'h': |
| 323 | usage(stderr); |
| 324 | goto error; |
| 325 | case 'v': |
| 326 | opt_verbose = 1; |
| 327 | break; |
| 328 | case 'q': |
| 329 | opt_quiet = 1; |
| 330 | break; |
| 331 | case 'g': |
| 332 | lttng_set_tracing_group(optarg); |
| 333 | break; |
| 334 | case OPT_NO_SESSIOND: |
| 335 | opt_no_sessiond = 1; |
| 336 | break; |
| 337 | case OPT_SESSION_PATH: |
| 338 | opt_sessiond_path = strdup(optarg); |
| 339 | break; |
| 340 | default: |
| 341 | usage(stderr); |
| 342 | goto error; |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | /* If both options are specified, quiet wins */ |
| 347 | if (opt_verbose && opt_quiet) { |
| 348 | opt_verbose = 0; |
| 349 | } |
| 350 | |
| 351 | /* Spawn session daemon if needed */ |
| 352 | if (opt_no_sessiond == 0 && (check_sessiond() < 0)) { |
| 353 | goto error; |
| 354 | } |
| 355 | |
| 356 | /* No leftovers, print usage and quit */ |
| 357 | if ((argc - optind) == 0) { |
| 358 | usage(stderr); |
| 359 | goto error; |
| 360 | } |
| 361 | |
| 362 | /* |
| 363 | * Handle leftovers which is a first level command with the trailing |
| 364 | * options. |
| 365 | */ |
| 366 | ret = handle_command(argc - optind, argv + optind); |
| 367 | if (ret < 0) { |
| 368 | if (ret == -1) { |
| 369 | usage(stderr); |
| 370 | goto error; |
| 371 | } else { |
| 372 | ERR("%s", lttng_get_readable_code(ret)); |
| 373 | } |
| 374 | } |
| 375 | |
| 376 | return ret; |
| 377 | |
| 378 | error: |
| 379 | return -1; |
| 380 | } |
| 381 | |
| 382 | |
| 383 | /* |
| 384 | * main |
| 385 | */ |
| 386 | int main(int argc, char *argv[]) |
| 387 | { |
| 388 | int ret; |
| 389 | |
| 390 | progname = argv[0] ? argv[0] : "lttng"; |
| 391 | |
| 392 | /* For Mathieu Desnoyers aka Dr Tracing */ |
| 393 | if (strncmp(progname, "drtrace", 7) == 0) { |
| 394 | MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n\n", 27,1,33,27,0); |
| 395 | } |
| 396 | |
| 397 | ret = set_signal_handler(); |
| 398 | if (ret < 0) { |
| 399 | clean_exit(ret); |
| 400 | } |
| 401 | |
| 402 | ret = parse_args(argc, argv); |
| 403 | clean_exit(ret); |
| 404 | |
| 405 | return 0; |
| 406 | } |