| 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 <errno.h> |
| 21 | #include <fcntl.h> |
| 22 | #include <getopt.h> |
| 23 | #include <grp.h> |
| 24 | #include <limits.h> |
| 25 | #include <stdio.h> |
| 26 | #include <stdlib.h> |
| 27 | #include <string.h> |
| 28 | #include <sys/stat.h> |
| 29 | #include <sys/types.h> |
| 30 | #include <sys/wait.h> |
| 31 | #include <unistd.h> |
| 32 | |
| 33 | #include <lttng/lttng.h> |
| 34 | |
| 35 | #include "lttngerr.h" |
| 36 | #include "options.h" |
| 37 | |
| 38 | /* Variables */ |
| 39 | static char *progname; |
| 40 | static char *session_name; |
| 41 | static uuid_t current_uuid; |
| 42 | static int auto_session; |
| 43 | static int auto_trace; |
| 44 | |
| 45 | /* Prototypes */ |
| 46 | static int process_client_opt(void); |
| 47 | static int process_opt_list_apps(void); |
| 48 | static int process_opt_list_sessions(void); |
| 49 | static int process_opt_list_traces(void); |
| 50 | static int process_opt_kernel_list_events(void); |
| 51 | static int process_opt_create_session(void); |
| 52 | static int process_kernel_create_trace(void); |
| 53 | static int process_opt_kernel_event(void); |
| 54 | static int process_kernel_start_trace(void); |
| 55 | static int set_session_uuid(void); |
| 56 | static void sighandler(int sig); |
| 57 | static int set_signal_handler(void); |
| 58 | static int validate_options(void); |
| 59 | static char *get_cmdline_by_pid(pid_t pid); |
| 60 | static void set_opt_session_info(void); |
| 61 | |
| 62 | /* |
| 63 | * start_client |
| 64 | * |
| 65 | * Process client request from the command line |
| 66 | * options. Every tracing action is done by the |
| 67 | * liblttngctl API. |
| 68 | */ |
| 69 | static int process_client_opt(void) |
| 70 | { |
| 71 | int ret; |
| 72 | |
| 73 | set_opt_session_info(); |
| 74 | |
| 75 | if (opt_list_apps) { |
| 76 | ret = process_opt_list_apps(); |
| 77 | if (ret < 0) { |
| 78 | goto end; |
| 79 | } |
| 80 | goto error; |
| 81 | } |
| 82 | |
| 83 | if (opt_list_session) { |
| 84 | ret = process_opt_list_sessions(); |
| 85 | if (ret < 0) { |
| 86 | goto end; |
| 87 | } |
| 88 | goto error; |
| 89 | } |
| 90 | |
| 91 | if (opt_list_events) { |
| 92 | if (opt_trace_kernel) { |
| 93 | ret = process_opt_kernel_list_events(); |
| 94 | if (ret < 0) { |
| 95 | goto end; |
| 96 | } |
| 97 | } else if (opt_trace_pid != 0) { |
| 98 | // TODO |
| 99 | } |
| 100 | goto error; |
| 101 | } |
| 102 | |
| 103 | /* Session creation or auto session set on */ |
| 104 | if (auto_session || opt_create_session) { |
| 105 | DBG("Creating a new session"); |
| 106 | ret = process_opt_create_session(); |
| 107 | if (ret < 0) { |
| 108 | goto end; |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | ret = set_session_uuid(); |
| 113 | if (ret < 0) { |
| 114 | ERR("Session %s not found", opt_session_name); |
| 115 | goto error; |
| 116 | } |
| 117 | |
| 118 | if (opt_destroy_session) { |
| 119 | ret = lttng_destroy_session(¤t_uuid); |
| 120 | if (ret < 0) { |
| 121 | goto end; |
| 122 | } |
| 123 | MSG("Session %s destroyed.", opt_session_name); |
| 124 | } |
| 125 | |
| 126 | if (opt_list_traces) { |
| 127 | ret = process_opt_list_traces(); |
| 128 | if (ret < 0) { |
| 129 | goto end; |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * Action on traces (kernel or/and userspace). |
| 135 | */ |
| 136 | |
| 137 | if (opt_trace_kernel) { |
| 138 | if (auto_trace || opt_create_trace) { |
| 139 | DBG("Creating a kernel trace"); |
| 140 | ret = process_kernel_create_trace(); |
| 141 | if (ret < 0) { |
| 142 | goto end; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | if (opt_event_list != NULL || opt_enable_all_event) { |
| 147 | ret = process_opt_kernel_event(); |
| 148 | if (ret < 0) { |
| 149 | goto end; |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | if (auto_trace || opt_start_trace) { |
| 154 | DBG("Starting kernel tracing"); |
| 155 | ret = process_kernel_start_trace(); |
| 156 | if (ret < 0) { |
| 157 | goto end; |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | if (opt_stop_trace) { |
| 162 | DBG("Stopping kernel tracing"); |
| 163 | ret = lttng_kernel_stop_tracing(); |
| 164 | if (ret < 0) { |
| 165 | goto end; |
| 166 | } |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | if (opt_trace_pid != 0) { |
| 171 | if (auto_trace || opt_create_trace) { |
| 172 | DBG("Create a userspace trace for pid %d", opt_trace_pid); |
| 173 | ret = lttng_ust_create_trace(opt_trace_pid); |
| 174 | if (ret < 0) { |
| 175 | goto end; |
| 176 | } |
| 177 | MSG("Trace created successfully!"); |
| 178 | } |
| 179 | |
| 180 | if (auto_trace || opt_start_trace) { |
| 181 | DBG("Start trace for pid %d", opt_trace_pid); |
| 182 | ret = lttng_ust_start_trace(opt_trace_pid); |
| 183 | if (ret < 0) { |
| 184 | goto end; |
| 185 | } |
| 186 | MSG("Trace started successfully!"); |
| 187 | } else if (opt_stop_trace) { |
| 188 | DBG("Stop trace for pid %d", opt_trace_pid); |
| 189 | ret = lttng_ust_stop_trace(opt_trace_pid); |
| 190 | if (ret < 0) { |
| 191 | goto end; |
| 192 | } |
| 193 | MSG("Trace stopped successfully!"); |
| 194 | } |
| 195 | |
| 196 | } |
| 197 | |
| 198 | return 0; |
| 199 | |
| 200 | end: |
| 201 | ERR("%s", lttng_get_readable_code(ret)); |
| 202 | error: /* fall through */ |
| 203 | return ret; |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * process_kernel_start_trace |
| 208 | * |
| 209 | * Start a kernel trace. |
| 210 | */ |
| 211 | static int process_kernel_start_trace(void) |
| 212 | { |
| 213 | int ret; |
| 214 | |
| 215 | ret = lttng_kernel_create_stream(); |
| 216 | if (ret < 0) { |
| 217 | goto error; |
| 218 | } |
| 219 | |
| 220 | ret = lttng_kernel_start_tracing(); |
| 221 | if (ret < 0) { |
| 222 | goto error; |
| 223 | } |
| 224 | |
| 225 | MSG("Kernel tracing started"); |
| 226 | |
| 227 | return 0; |
| 228 | |
| 229 | error: |
| 230 | return ret; |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | * process_kernel_create_trace |
| 235 | * |
| 236 | * Create a kernel trace. |
| 237 | */ |
| 238 | static int process_kernel_create_trace(void) |
| 239 | { |
| 240 | int ret; |
| 241 | |
| 242 | /* Setup kernel session */ |
| 243 | ret = lttng_kernel_create_session(); |
| 244 | if (ret < 0) { |
| 245 | goto error; |
| 246 | } |
| 247 | |
| 248 | /* Create an empty channel (with no event) */ |
| 249 | ret = lttng_kernel_create_channel(); |
| 250 | if (ret < 0) { |
| 251 | goto error; |
| 252 | } |
| 253 | |
| 254 | /* Opening metadata for session */ |
| 255 | ret = lttng_kernel_open_metadata(); |
| 256 | if (ret < 0) { |
| 257 | goto error; |
| 258 | } |
| 259 | |
| 260 | return 0; |
| 261 | |
| 262 | error: |
| 263 | return ret; |
| 264 | } |
| 265 | |
| 266 | /* |
| 267 | * process_opt_kernel_list_events |
| 268 | * |
| 269 | * Ask for all trace events in the kernel and pretty print them. |
| 270 | */ |
| 271 | static int process_opt_kernel_list_events(void) |
| 272 | { |
| 273 | int ret, pos, size; |
| 274 | char *event_list, *event, *ptr; |
| 275 | |
| 276 | DBG("Getting all tracing events"); |
| 277 | |
| 278 | ret = lttng_kernel_list_events(&event_list); |
| 279 | if (ret < 0) { |
| 280 | ERR("Unable to list events."); |
| 281 | return ret; |
| 282 | } |
| 283 | |
| 284 | MSG("Kernel tracepoints:\n-------------"); |
| 285 | |
| 286 | ptr = event_list; |
| 287 | while ((size = sscanf(ptr, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) { |
| 288 | MSG(" - %s", event); |
| 289 | /* Move pointer to the next line */ |
| 290 | ptr += pos + 1; |
| 291 | free(event); |
| 292 | } |
| 293 | |
| 294 | free(event_list); |
| 295 | |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | /* |
| 300 | * process_opt_kernel_event |
| 301 | * |
| 302 | * Enable kernel event from the command line list given. |
| 303 | */ |
| 304 | static int process_opt_kernel_event(void) |
| 305 | { |
| 306 | int ret; |
| 307 | char *event_name; |
| 308 | |
| 309 | if (opt_enable_all_event) { |
| 310 | ret = lttng_kernel_enable_event(NULL); |
| 311 | if (ret < 0) { |
| 312 | ERR("%s", lttng_get_readable_code(ret)); |
| 313 | } else { |
| 314 | MSG("All kernel event enabled"); |
| 315 | } |
| 316 | |
| 317 | goto end; |
| 318 | } |
| 319 | |
| 320 | event_name = strtok(opt_event_list, ","); |
| 321 | while (event_name != NULL) { |
| 322 | DBG("Enabling kernel event %s", event_name); |
| 323 | ret = lttng_kernel_enable_event(event_name); |
| 324 | if (ret < 0) { |
| 325 | ERR("%s %s", lttng_get_readable_code(ret), event_name); |
| 326 | } else { |
| 327 | MSG("Kernel event %s enabled.", event_name); |
| 328 | } |
| 329 | /* Next event */ |
| 330 | event_name = strtok(NULL, ","); |
| 331 | } |
| 332 | |
| 333 | end: |
| 334 | return 0; |
| 335 | } |
| 336 | |
| 337 | /* |
| 338 | * set_opt_session_info |
| 339 | * |
| 340 | * Setup session_name, current_uuid, short_str_uuid and |
| 341 | * long_str_uuid using the command line options. |
| 342 | */ |
| 343 | static void set_opt_session_info(void) |
| 344 | { |
| 345 | if (opt_session_name != NULL) { |
| 346 | session_name = strndup(opt_session_name, NAME_MAX); |
| 347 | DBG("Session name set to %s", session_name); |
| 348 | } |
| 349 | } |
| 350 | |
| 351 | /* |
| 352 | * set_session_uuid |
| 353 | * |
| 354 | * Set current session uuid to the current flow of command(s) using the |
| 355 | * session_name. |
| 356 | */ |
| 357 | static int set_session_uuid(void) |
| 358 | { |
| 359 | int ret, count, i, found = 0; |
| 360 | struct lttng_session *sessions; |
| 361 | |
| 362 | if (!uuid_is_null(current_uuid)) { |
| 363 | lttng_set_current_session_uuid(¤t_uuid); |
| 364 | goto end; |
| 365 | } |
| 366 | |
| 367 | count = lttng_list_sessions(&sessions); |
| 368 | if (count < 0) { |
| 369 | ret = count; |
| 370 | goto error; |
| 371 | } |
| 372 | |
| 373 | for (i = 0; i < count; i++) { |
| 374 | if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) { |
| 375 | lttng_set_current_session_uuid(&sessions[i].uuid); |
| 376 | uuid_copy(current_uuid, sessions[i].uuid); |
| 377 | found = 1; |
| 378 | break; |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | free(sessions); |
| 383 | |
| 384 | if (!found) { |
| 385 | return -1; |
| 386 | } |
| 387 | |
| 388 | end: |
| 389 | DBG("Session UUID set"); |
| 390 | return 0; |
| 391 | |
| 392 | error: |
| 393 | return ret; |
| 394 | } |
| 395 | |
| 396 | /* |
| 397 | * process_opt_list_traces |
| 398 | * |
| 399 | * Get list of all traces for a specific session uuid. |
| 400 | */ |
| 401 | static int process_opt_list_traces(void) |
| 402 | { |
| 403 | int ret, i; |
| 404 | struct lttng_trace *traces; |
| 405 | |
| 406 | ret = lttng_list_traces(¤t_uuid, &traces); |
| 407 | DBG("Number of traces to list %d", ret); |
| 408 | if (ret < 0) { |
| 409 | goto error; |
| 410 | } |
| 411 | |
| 412 | /* No traces */ |
| 413 | if (ret == 0) { |
| 414 | MSG("No traces found."); |
| 415 | goto error; |
| 416 | } |
| 417 | |
| 418 | MSG("Userspace traces:"); |
| 419 | for (i = 0; i < ret; i++) { |
| 420 | if (traces[i].type == USERSPACE) { |
| 421 | MSG("\t%d) %s (pid: %d): %s", |
| 422 | i, traces[i].name, traces[i].pid, |
| 423 | get_cmdline_by_pid(traces[i].pid)); |
| 424 | } else { |
| 425 | break; |
| 426 | } |
| 427 | } |
| 428 | |
| 429 | MSG("Kernel traces:"); |
| 430 | for (;i < ret; i++) { |
| 431 | if (traces[i].type == KERNEL) { |
| 432 | MSG("\t%d) %s", i, traces[i].name); |
| 433 | } |
| 434 | } |
| 435 | |
| 436 | free(traces); |
| 437 | |
| 438 | error: |
| 439 | return ret; |
| 440 | } |
| 441 | |
| 442 | /* |
| 443 | * process_opt_create_session |
| 444 | * |
| 445 | * Create a new session using the name pass |
| 446 | * to the command line. |
| 447 | */ |
| 448 | static int process_opt_create_session(void) |
| 449 | { |
| 450 | int ret; |
| 451 | char name[NAME_MAX]; |
| 452 | time_t rawtime; |
| 453 | struct tm *timeinfo; |
| 454 | |
| 455 | /* Auto session name creation */ |
| 456 | if (opt_session_name == NULL) { |
| 457 | time(&rawtime); |
| 458 | timeinfo = localtime(&rawtime); |
| 459 | strftime(name, sizeof(name), "auto-%Y%m%d-%H%M%S", timeinfo); |
| 460 | session_name = strndup(name, sizeof(name)); |
| 461 | DBG("Auto session name set to %s", session_name); |
| 462 | } |
| 463 | |
| 464 | ret = lttng_create_session(session_name); |
| 465 | if (ret < 0) { |
| 466 | goto error; |
| 467 | } |
| 468 | |
| 469 | MSG("Session created: %s", session_name); |
| 470 | |
| 471 | error: |
| 472 | return ret; |
| 473 | } |
| 474 | |
| 475 | /* |
| 476 | * process_opt_list_sessions |
| 477 | * |
| 478 | * Get the list of available sessions from |
| 479 | * the session daemon and print it to user. |
| 480 | */ |
| 481 | static int process_opt_list_sessions(void) |
| 482 | { |
| 483 | int ret, count, i; |
| 484 | struct lttng_session *sessions; |
| 485 | |
| 486 | count = lttng_list_sessions(&sessions); |
| 487 | DBG("Session count %d", count); |
| 488 | if (count < 0) { |
| 489 | ret = count; |
| 490 | goto error; |
| 491 | } |
| 492 | |
| 493 | MSG("Available sessions (UUIDs):"); |
| 494 | for (i = 0; i < count; i++) { |
| 495 | MSG(" %d) %s", i+1, sessions[i].name); |
| 496 | } |
| 497 | |
| 498 | free(sessions); |
| 499 | MSG("\nTo select a session, use -s, --session UUID."); |
| 500 | |
| 501 | return 0; |
| 502 | |
| 503 | error: |
| 504 | return ret; |
| 505 | } |
| 506 | |
| 507 | /* |
| 508 | * process_opt_list_apps |
| 509 | * |
| 510 | * Get the UST traceable pid list and print |
| 511 | * them to the user. |
| 512 | */ |
| 513 | static int process_opt_list_apps(void) |
| 514 | { |
| 515 | int i, ret, count; |
| 516 | pid_t *pids; |
| 517 | char *cmdline; |
| 518 | |
| 519 | count = lttng_ust_list_apps(&pids); |
| 520 | if (count < 0) { |
| 521 | ret = count; |
| 522 | goto error; |
| 523 | } |
| 524 | |
| 525 | MSG("LTTng UST traceable application [name (pid)]:"); |
| 526 | for (i=0; i < count; i++) { |
| 527 | cmdline = get_cmdline_by_pid(pids[i]); |
| 528 | if (cmdline == NULL) { |
| 529 | MSG("\t(not running) (%d)", pids[i]); |
| 530 | continue; |
| 531 | } |
| 532 | MSG("\t%s (%d)", cmdline, pids[i]); |
| 533 | free(cmdline); |
| 534 | } |
| 535 | |
| 536 | /* Allocated by lttng_ust_list_apps() */ |
| 537 | free(pids); |
| 538 | |
| 539 | return 0; |
| 540 | |
| 541 | error: |
| 542 | return ret; |
| 543 | } |
| 544 | |
| 545 | /* |
| 546 | * get_cmdline_by_pid |
| 547 | * |
| 548 | * Get command line from /proc for a specific pid. |
| 549 | * |
| 550 | * On success, return an allocated string pointer pointing to |
| 551 | * the proc cmdline. |
| 552 | * On error, return NULL. |
| 553 | */ |
| 554 | static char *get_cmdline_by_pid(pid_t pid) |
| 555 | { |
| 556 | int ret; |
| 557 | FILE *fp; |
| 558 | char *cmdline = NULL; |
| 559 | char path[24]; /* Can't go bigger than /proc/65535/cmdline */ |
| 560 | |
| 561 | snprintf(path, sizeof(path), "/proc/%d/cmdline", pid); |
| 562 | fp = fopen(path, "r"); |
| 563 | if (fp == NULL) { |
| 564 | goto end; |
| 565 | } |
| 566 | |
| 567 | /* Caller must free() *cmdline */ |
| 568 | cmdline = malloc(PATH_MAX); |
| 569 | ret = fread(cmdline, 1, PATH_MAX, fp); |
| 570 | fclose(fp); |
| 571 | |
| 572 | end: |
| 573 | return cmdline; |
| 574 | } |
| 575 | |
| 576 | /* |
| 577 | * validate_options |
| 578 | * |
| 579 | * Make sure that all options passed to the command line are compatible with |
| 580 | * each others. |
| 581 | * |
| 582 | * On error, return -1 |
| 583 | * On success, return 0 |
| 584 | */ |
| 585 | static int validate_options(void) |
| 586 | { |
| 587 | /* If listing options, jump validation */ |
| 588 | if (opt_list_apps || opt_list_session) { |
| 589 | goto end; |
| 590 | } |
| 591 | /* Conflicting command */ |
| 592 | if (opt_start_trace && opt_stop_trace) { |
| 593 | ERR("Can't use --start and --stop together."); |
| 594 | goto error; |
| 595 | /* If no PID specified and trace_kernel is off */ |
| 596 | } else if ((opt_trace_pid == 0 && !opt_trace_kernel) && |
| 597 | (opt_create_trace || opt_start_trace || opt_stop_trace || opt_destroy_trace)) { |
| 598 | ERR("Please specify for which tracer (-k or -p PID)."); |
| 599 | goto error; |
| 600 | /* List traces, we need a session name */ |
| 601 | } else if (opt_list_traces && opt_session_name == NULL) { |
| 602 | ERR("Can't use -t without -s, --session option."); |
| 603 | goto error; |
| 604 | /* Can't set event for both kernel and userspace at the same time */ |
| 605 | } else if (opt_event_list != NULL && (opt_trace_kernel && opt_trace_pid)) { |
| 606 | ERR("Please don't use --event for both kernel and userspace.\nOne at a time to enable events."); |
| 607 | goto error; |
| 608 | /* Don't need a trace name for kernel tracig */ |
| 609 | } else if (opt_trace_name != NULL && opt_trace_kernel) { |
| 610 | ERR("For action on a kernel trace, please don't specify a trace name."); |
| 611 | goto error; |
| 612 | } else if (opt_destroy_trace && opt_session_name == NULL) { |
| 613 | ERR("Please specify a session in order to destroy a trace"); |
| 614 | goto error; |
| 615 | } else if (opt_create_trace || opt_destroy_trace) { |
| 616 | /* Both kernel and user-space are denied for these options */ |
| 617 | if (opt_trace_pid != 0 && opt_trace_kernel) { |
| 618 | ERR("Kernel and user-space trace creation and destruction can't be used together."); |
| 619 | goto error; |
| 620 | /* Need a trace name for user-space tracing */ |
| 621 | } else if (opt_trace_name == NULL && opt_trace_pid != 0) { |
| 622 | ERR("Please specify a trace name for user-space tracing"); |
| 623 | goto error; |
| 624 | } |
| 625 | } else if (opt_stop_trace && opt_trace_pid != 0 && opt_trace_name == NULL) { |
| 626 | ERR("Please specify a trace name for user-space tracing"); |
| 627 | goto error; |
| 628 | } else if (opt_stop_trace && opt_session_name == NULL) { |
| 629 | ERR("Please specify a session to stop tracing"); |
| 630 | goto error; |
| 631 | } |
| 632 | |
| 633 | /* If start trace, auto start tracing */ |
| 634 | if (opt_start_trace || opt_event_list != NULL || opt_enable_all_event) { |
| 635 | DBG("Requesting auto tracing"); |
| 636 | auto_trace = 1; |
| 637 | } |
| 638 | |
| 639 | /* If no session, auto create one */ |
| 640 | if (opt_session_name == NULL) { |
| 641 | DBG("Requesting an auto session creation"); |
| 642 | auto_session = 1; |
| 643 | } |
| 644 | |
| 645 | end: |
| 646 | return 0; |
| 647 | |
| 648 | error: |
| 649 | return -1; |
| 650 | } |
| 651 | |
| 652 | /* |
| 653 | * spawn_sessiond |
| 654 | * |
| 655 | * Spawn a session daemon by forking and execv. |
| 656 | */ |
| 657 | static int spawn_sessiond(char *pathname) |
| 658 | { |
| 659 | int ret = 0; |
| 660 | pid_t pid; |
| 661 | |
| 662 | MSG("Spawning session daemon"); |
| 663 | pid = fork(); |
| 664 | if (pid == 0) { |
| 665 | /* |
| 666 | * Spawn session daemon and tell |
| 667 | * it to signal us when ready. |
| 668 | */ |
| 669 | execlp(pathname, "ltt-sessiond", "--sig-parent", "--quiet", NULL); |
| 670 | /* execlp only returns if error happened */ |
| 671 | if (errno == ENOENT) { |
| 672 | ERR("No session daemon found. Use --sessiond-path."); |
| 673 | } else { |
| 674 | perror("execlp"); |
| 675 | } |
| 676 | kill(getppid(), SIGTERM); /* unpause parent */ |
| 677 | exit(EXIT_FAILURE); |
| 678 | } else if (pid > 0) { |
| 679 | /* Wait for ltt-sessiond to start */ |
| 680 | pause(); |
| 681 | goto end; |
| 682 | } else { |
| 683 | perror("fork"); |
| 684 | ret = -1; |
| 685 | goto end; |
| 686 | } |
| 687 | |
| 688 | end: |
| 689 | return ret; |
| 690 | } |
| 691 | |
| 692 | /* |
| 693 | * check_ltt_sessiond |
| 694 | * |
| 695 | * Check if the session daemon is available using |
| 696 | * the liblttngctl API for the check. If not, try to |
| 697 | * spawn a daemon. |
| 698 | */ |
| 699 | static int check_ltt_sessiond(void) |
| 700 | { |
| 701 | int ret; |
| 702 | char *pathname = NULL, *alloc_pathname = NULL; |
| 703 | |
| 704 | ret = lttng_session_daemon_alive(); |
| 705 | if (ret == 0) { /* not alive */ |
| 706 | /* Try command line option path */ |
| 707 | if (opt_sessiond_path != NULL) { |
| 708 | ret = access(opt_sessiond_path, F_OK | X_OK); |
| 709 | if (ret < 0) { |
| 710 | ERR("No such file: %s", opt_sessiond_path); |
| 711 | goto end; |
| 712 | } |
| 713 | pathname = opt_sessiond_path; |
| 714 | } else { |
| 715 | /* Try LTTNG_SESSIOND_PATH env variable */ |
| 716 | pathname = getenv(LTTNG_SESSIOND_PATH_ENV); |
| 717 | } |
| 718 | |
| 719 | /* Let's rock and roll */ |
| 720 | if (pathname == NULL) { |
| 721 | ret = asprintf(&alloc_pathname, "ltt-sessiond"); |
| 722 | if (ret < 0) { |
| 723 | goto end; |
| 724 | } |
| 725 | pathname = alloc_pathname; |
| 726 | } |
| 727 | |
| 728 | ret = spawn_sessiond(pathname); |
| 729 | free(alloc_pathname); |
| 730 | if (ret < 0) { |
| 731 | ERR("Problem occurs when starting %s", pathname); |
| 732 | goto end; |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | end: |
| 737 | return ret; |
| 738 | } |
| 739 | |
| 740 | /* |
| 741 | * set_signal_handler |
| 742 | * |
| 743 | * Setup signal handler for SIGCHLD and SIGTERM. |
| 744 | */ |
| 745 | static int set_signal_handler(void) |
| 746 | { |
| 747 | int ret = 0; |
| 748 | struct sigaction sa; |
| 749 | sigset_t sigset; |
| 750 | |
| 751 | if ((ret = sigemptyset(&sigset)) < 0) { |
| 752 | perror("sigemptyset"); |
| 753 | goto end; |
| 754 | } |
| 755 | |
| 756 | sa.sa_handler = sighandler; |
| 757 | sa.sa_mask = sigset; |
| 758 | sa.sa_flags = 0; |
| 759 | if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) { |
| 760 | perror("sigaction"); |
| 761 | goto end; |
| 762 | } |
| 763 | |
| 764 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { |
| 765 | perror("sigaction"); |
| 766 | goto end; |
| 767 | } |
| 768 | |
| 769 | end: |
| 770 | return ret; |
| 771 | } |
| 772 | |
| 773 | /* |
| 774 | * sighandler |
| 775 | * |
| 776 | * Signal handler for the daemon |
| 777 | */ |
| 778 | static void sighandler(int sig) |
| 779 | { |
| 780 | switch (sig) { |
| 781 | case SIGTERM: |
| 782 | DBG("SIGTERM catched"); |
| 783 | clean_exit(EXIT_FAILURE); |
| 784 | break; |
| 785 | case SIGCHLD: |
| 786 | /* Notify is done */ |
| 787 | DBG("SIGCHLD catched"); |
| 788 | break; |
| 789 | default: |
| 790 | DBG("Unknown signal %d catched", sig); |
| 791 | break; |
| 792 | } |
| 793 | |
| 794 | return; |
| 795 | } |
| 796 | |
| 797 | /* |
| 798 | * clean_exit |
| 799 | */ |
| 800 | void clean_exit(int code) |
| 801 | { |
| 802 | DBG("Clean exit"); |
| 803 | if (session_name) { |
| 804 | free(session_name); |
| 805 | } |
| 806 | |
| 807 | exit(code); |
| 808 | } |
| 809 | |
| 810 | /* |
| 811 | * main |
| 812 | */ |
| 813 | int main(int argc, char *argv[]) |
| 814 | { |
| 815 | int ret; |
| 816 | |
| 817 | progname = argv[0] ? argv[0] : "lttng"; |
| 818 | |
| 819 | /* For Mathieu Desnoyers aka Dr Tracing */ |
| 820 | if (strncmp(progname, "drtrace", 7) == 0) { |
| 821 | MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n\n", 27,1,33,27,0); |
| 822 | } |
| 823 | |
| 824 | ret = parse_args(argc, (const char **) argv); |
| 825 | if (ret < 0) { |
| 826 | clean_exit(EXIT_FAILURE); |
| 827 | } |
| 828 | |
| 829 | ret = validate_options(); |
| 830 | if (ret < 0) { |
| 831 | return EXIT_FAILURE; |
| 832 | } |
| 833 | |
| 834 | ret = set_signal_handler(); |
| 835 | if (ret < 0) { |
| 836 | clean_exit(ret); |
| 837 | } |
| 838 | |
| 839 | if (opt_tracing_group != NULL) { |
| 840 | DBG("Set tracing group to '%s'", opt_tracing_group); |
| 841 | lttng_set_tracing_group(opt_tracing_group); |
| 842 | } |
| 843 | |
| 844 | /* If ask for kernel tracing, need root perms */ |
| 845 | if (opt_trace_kernel) { |
| 846 | DBG("Kernel tracing activated"); |
| 847 | if (getuid() != 0) { |
| 848 | ERR("%s must be setuid root", progname); |
| 849 | clean_exit(-EPERM); |
| 850 | } |
| 851 | } |
| 852 | |
| 853 | /* Check if the lttng session daemon is running. |
| 854 | * If no, a daemon will be spawned. |
| 855 | */ |
| 856 | if (opt_no_sessiond == 0 && (check_ltt_sessiond() < 0)) { |
| 857 | clean_exit(EXIT_FAILURE); |
| 858 | } |
| 859 | |
| 860 | ret = process_client_opt(); |
| 861 | if (ret < 0) { |
| 862 | clean_exit(ret); |
| 863 | } |
| 864 | |
| 865 | clean_exit(0); |
| 866 | |
| 867 | return 0; |
| 868 | } |