liblttngctl/lttngctl.c

   1 /*
   2  * liblttngctl.c
   3  *
   4  * Linux Trace Toolkit Control Library
   5  *
   6  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #define _GNU_SOURCE
  24 #include <grp.h>
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30
  31 #include <lttng-sessiond-comm.h>
  32 #include <lttng-share.h>
  33 #include <lttng/lttng.h>
  34 #include <lttngerr.h>
  35
  36 /* Socket to session daemon for communication */
  37 static int sessiond_socket;
  38 static char sessiond_sock_path[PATH_MAX];
  39
  40 /* Variables */
  41 static char *tracing_group;
  42 static int connected;
  43
  44 /*
  45  * Copy string from src to dst and enforce null terminated byte.
  46  */
  47 static void copy_string(char *dst, const char *src, size_t len)
  48 {
  49         if (src && dst) {
  50                 strncpy(dst, src, len);
  51                 /* Enforce the NULL terminated byte */
  52                 dst[len - 1] = '\0';
  53         } else if (dst) {
  54                 dst[0] = '\0';
  55         }
  56 }
  57
  58 /*
  59  * Copy domain to lttcomm_session_msg domain.
  60  *
  61  * If domain is unknown, default domain will be the kernel.
  62  */
  63 static void copy_lttng_domain(struct lttng_domain *dst, struct lttng_domain *src)
  64 {
  65         if (src && dst) {
  66                 switch (src->type) {
  67                         case LTTNG_DOMAIN_KERNEL:
  68                         case LTTNG_DOMAIN_UST:
  69                         case LTTNG_DOMAIN_UST_EXEC_NAME:
  70                         case LTTNG_DOMAIN_UST_PID:
  71                         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
  72                                 memcpy(dst, src, sizeof(struct lttng_domain));
  73                                 break;
  74                         default:
  75                                 dst->type = LTTNG_DOMAIN_KERNEL;
  76                                 break;
  77                 }
  78         }
  79 }
  80
  81 /*
  82  * Send lttcomm_session_msg to the session daemon.
  83  *
  84  * On success, return 0
  85  * On error, return error code
  86  */
  87 static int send_session_msg(struct lttcomm_session_msg *lsm)
  88 {
  89         int ret;
  90
  91         if (!connected) {
  92                 ret = -ENOTCONN;
  93                 goto end;
  94         }
  95
  96         ret = lttcomm_send_unix_sock(sessiond_socket, lsm,
  97                         sizeof(struct lttcomm_session_msg));
  98
  99 end:
 100         return ret;
 101 }
 102
 103 /*
 104  * Receive data from the sessiond socket.
 105  *
 106  * On success, return 0
 107  * On error, return recv() error code
 108  */
 109 static int recv_data_sessiond(void *buf, size_t len)
 110 {
 111         int ret;
 112
 113         if (!connected) {
 114                 ret = -ENOTCONN;
 115                 goto end;
 116         }
 117
 118         ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
 119
 120 end:
 121         return ret;
 122 }
 123
 124 /*
 125  *  Check if the specified group name exist.
 126  *
 127  *  If yes return 1, else return -1.
 128  */
 129 static int check_tracing_group(const char *grp_name)
 130 {
 131         struct group *grp_tracing;      /* no free(). See getgrnam(3) */
 132         gid_t *grp_list;
 133         int grp_list_size, grp_id, i;
 134         int ret = -1;
 135
 136         /* Get GID of group 'tracing' */
 137         grp_tracing = getgrnam(grp_name);
 138         if (grp_tracing == NULL) {
 139                 /* NULL means not found also. getgrnam(3) */
 140                 if (errno != 0) {
 141                         perror("getgrnam");
 142                 }
 143                 goto end;
 144         }
 145
 146         /* Get number of supplementary group IDs */
 147         grp_list_size = getgroups(0, NULL);
 148         if (grp_list_size < 0) {
 149                 perror("getgroups");
 150                 goto end;
 151         }
 152
 153         /* Alloc group list of the right size */
 154         grp_list = malloc(grp_list_size * sizeof(gid_t));
 155         if (!grp_list) {
 156                 ret = -1;
 157                 goto end;
 158         }
 159         grp_id = getgroups(grp_list_size, grp_list);
 160         if (grp_id < -1) {
 161                 perror("getgroups");
 162                 goto free_list;
 163         }
 164
 165         for (i = 0; i < grp_list_size; i++) {
 166                 if (grp_list[i] == grp_tracing->gr_gid) {
 167                         ret = 1;
 168                         break;
 169                 }
 170         }
 171
 172 free_list:
 173         free(grp_list);
 174
 175 end:
 176         return ret;
 177 }
 178
 179 /*
 180  * Try connect to session daemon with sock_path.
 181  *
 182  * Return 0 on success, else -1
 183  */
 184 static int try_connect_sessiond(const char *sock_path)
 185 {
 186         int ret;
 187
 188         /* If socket exist, we check if the daemon listens for connect. */
 189         ret = access(sock_path, F_OK);
 190         if (ret < 0) {
 191                 /* Not alive */
 192                 return -1;
 193         }
 194
 195         ret = lttcomm_connect_unix_sock(sock_path);
 196         if (ret < 0) {
 197                 /* Not alive */
 198                 return -1;
 199         }
 200
 201         ret = lttcomm_close_unix_sock(ret);
 202         if (ret < 0) {
 203                 perror("lttcomm_close_unix_sock");
 204         }
 205
 206         return 0;
 207 }
 208
 209 /*
 210  * Set sessiond socket path by putting it in the global sessiond_sock_path
 211  * variable.
 212  */
 213 static int set_session_daemon_path(void)
 214 {
 215         int ret;
 216         int in_tgroup = 0;      /* In tracing group */
 217         uid_t uid;
 218
 219         uid = getuid();
 220
 221         if (uid != 0) {
 222                 /* Are we in the tracing group ? */
 223                 in_tgroup = check_tracing_group(tracing_group);
 224         }
 225
 226         if (uid == 0) {
 227                 /* Root */
 228                 copy_string(sessiond_sock_path,
 229                                 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
 230                                 sizeof(sessiond_sock_path));
 231         } else if (in_tgroup) {
 232                 /* Tracing group */
 233                 copy_string(sessiond_sock_path,
 234                                 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
 235                                 sizeof(sessiond_sock_path));
 236
 237                 ret = try_connect_sessiond(sessiond_sock_path);
 238                 if (ret < 0) {
 239                         /* Global session daemon not available */
 240                         if (snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
 241                                                 DEFAULT_HOME_CLIENT_UNIX_SOCK,
 242                                                 getenv("HOME")) < 0) {
 243                                 return -ENOMEM;
 244                         }
 245                 }
 246         } else {
 247                 /* Not in tracing group and not root, default */
 248                 if (snprintf(sessiond_sock_path, PATH_MAX,
 249                                         DEFAULT_HOME_CLIENT_UNIX_SOCK,
 250                                         getenv("HOME")) < 0) {
 251                         return -ENOMEM;
 252                 }
 253         }
 254
 255         return 0;
 256 }
 257
 258 /*
 259  *  Connect to the LTTng session daemon.
 260  *
 261  *  On success, return 0. On error, return -1.
 262  */
 263 static int connect_sessiond(void)
 264 {
 265         int ret;
 266
 267         ret = set_session_daemon_path();
 268         if (ret < 0) {
 269                 return ret;
 270         }
 271
 272         /* Connect to the sesssion daemon */
 273         ret = lttcomm_connect_unix_sock(sessiond_sock_path);
 274         if (ret < 0) {
 275                 return ret;
 276         }
 277
 278         sessiond_socket = ret;
 279         connected = 1;
 280
 281         return 0;
 282 }
 283
 284 /*
 285  *  Clean disconnect the session daemon.
 286  */
 287 static int disconnect_sessiond(void)
 288 {
 289         int ret = 0;
 290
 291         if (connected) {
 292                 ret = lttcomm_close_unix_sock(sessiond_socket);
 293                 sessiond_socket = 0;
 294                 connected = 0;
 295         }
 296
 297         return ret;
 298 }
 299
 300 /*
 301  * Ask the session daemon a specific command and put the data into buf.
 302  *
 303  * Return size of data (only payload, not header).
 304  */
 305 static int ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
 306 {
 307         int ret;
 308         size_t size;
 309         void *data = NULL;
 310         struct lttcomm_lttng_msg llm;
 311
 312         ret = connect_sessiond();
 313         if (ret < 0) {
 314                 goto end;
 315         }
 316
 317         /* Send command to session daemon */
 318         ret = send_session_msg(lsm);
 319         if (ret < 0) {
 320                 goto end;
 321         }
 322
 323         /* Get header from data transmission */
 324         ret = recv_data_sessiond(&llm, sizeof(llm));
 325         if (ret < 0) {
 326                 goto end;
 327         }
 328
 329         /* Check error code if OK */
 330         if (llm.ret_code != LTTCOMM_OK) {
 331                 ret = -llm.ret_code;
 332                 goto end;
 333         }
 334
 335         size = llm.data_size;
 336         if (size == 0) {
 337                 /* If client free with size 0 */
 338                 *buf = NULL;
 339                 ret = 0;
 340                 goto end;
 341         }
 342
 343         data = (void*) malloc(size);
 344
 345         /* Get payload data */
 346         ret = recv_data_sessiond(data, size);
 347         if (ret < 0) {
 348                 free(data);
 349                 goto end;
 350         }
 351
 352         /*
 353          * Extra protection not to dereference a NULL pointer. If buf is NULL at
 354          * this point, an error is returned and data is freed.
 355          */
 356         if (buf == NULL) {
 357                 ret = -1;
 358                 free(data);
 359                 goto end;
 360         }
 361
 362         *buf = data;
 363         ret = size;
 364
 365 end:
 366         disconnect_sessiond();
 367         return ret;
 368 }
 369
 370 /*
 371  * Create lttng handle and return pointer.
 372  */
 373 struct lttng_handle *lttng_create_handle(const char *session_name,
 374                 struct lttng_domain *domain)
 375 {
 376         struct lttng_handle *handle;
 377
 378         handle = malloc(sizeof(struct lttng_handle));
 379         if (handle == NULL) {
 380                 perror("malloc handle");
 381                 goto end;
 382         }
 383
 384         /* Copy session name */
 385         copy_string(handle->session_name, session_name,
 386                         sizeof(handle->session_name));
 387
 388         /* Copy lttng domain */
 389         copy_lttng_domain(&handle->domain, domain);
 390
 391 end:
 392         return handle;
 393 }
 394
 395 /*
 396  * Destroy handle by free(3) the pointer.
 397  */
 398 void lttng_destroy_handle(struct lttng_handle *handle)
 399 {
 400         if (handle) {
 401                 free(handle);
 402         }
 403 }
 404
 405 /*
 406  * Register an outside consumer.
 407  */
 408 int lttng_register_consumer(struct lttng_handle *handle,
 409                 const char *socket_path)
 410 {
 411         struct lttcomm_session_msg lsm;
 412
 413         lsm.cmd_type = LTTNG_REGISTER_CONSUMER;
 414         copy_string(lsm.session.name, handle->session_name,
 415                         sizeof(lsm.session.name));
 416         copy_lttng_domain(&lsm.domain, &handle->domain);
 417
 418         copy_string(lsm.u.reg.path, socket_path, sizeof(lsm.u.reg.path));
 419
 420         return ask_sessiond(&lsm, NULL);
 421 }
 422
 423 /*
 424  *  Start tracing for all trace of the session.
 425  */
 426 int lttng_start_tracing(struct lttng_handle *handle)
 427 {
 428         struct lttcomm_session_msg lsm;
 429
 430         if (!handle) {
 431                 return -1;
 432         }
 433
 434         lsm.cmd_type = LTTNG_START_TRACE;
 435         copy_string(lsm.session.name, handle->session_name,
 436                         sizeof(lsm.session.name));
 437
 438         return ask_sessiond(&lsm, NULL);
 439 }
 440
 441 /*
 442  *  Stop tracing for all trace of the session.
 443  */
 444 int lttng_stop_tracing(struct lttng_handle *handle)
 445 {
 446         struct lttcomm_session_msg lsm;
 447
 448         lsm.cmd_type = LTTNG_STOP_TRACE;
 449         copy_string(lsm.session.name, handle->session_name,
 450                         sizeof(lsm.session.name));
 451
 452         return ask_sessiond(&lsm, NULL);
 453 }
 454
 455 /*
 456  * Add context to event or/and channel.
 457  */
 458 int lttng_add_context(struct lttng_handle *handle,
 459                 struct lttng_event_context *ctx, const char *event_name,
 460                 const char *channel_name)
 461 {
 462         struct lttcomm_session_msg lsm;
 463
 464         if (!handle) {
 465                 return -1;
 466         }
 467
 468         lsm.cmd_type = LTTNG_ADD_CONTEXT;
 469
 470         /* Copy channel name */
 471         copy_string(lsm.u.context.channel_name, channel_name,
 472                         sizeof(lsm.u.context.channel_name));
 473         /* Copy event name */
 474         copy_string(lsm.u.context.event_name, event_name,
 475                         sizeof(lsm.u.context.event_name));
 476
 477         copy_lttng_domain(&lsm.domain, &handle->domain);
 478
 479         if (ctx) {
 480                 memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context));
 481         }
 482
 483         copy_string(lsm.session.name, handle->session_name,
 484                         sizeof(lsm.session.name));
 485
 486         return ask_sessiond(&lsm, NULL);
 487 }
 488
 489 /*
 490  * Enable event
 491  */
 492 int lttng_enable_event(struct lttng_handle *handle,
 493                 struct lttng_event *ev, const char *channel_name)
 494 {
 495         struct lttcomm_session_msg lsm;
 496
 497         if (!handle || ev == NULL) {
 498                 return -1;
 499         }
 500
 501         if (channel_name == NULL) {
 502                 copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME,
 503                                 sizeof(lsm.u.enable.channel_name));
 504         } else {
 505                 copy_string(lsm.u.enable.channel_name, channel_name,
 506                                 sizeof(lsm.u.enable.channel_name));
 507         }
 508
 509         copy_lttng_domain(&lsm.domain, &handle->domain);
 510
 511         if (ev->name[0] != '\0') {
 512                 lsm.cmd_type = LTTNG_ENABLE_EVENT;
 513         } else {
 514                 lsm.cmd_type = LTTNG_ENABLE_ALL_EVENT;
 515         }
 516         memcpy(&lsm.u.enable.event, ev, sizeof(lsm.u.enable.event));
 517
 518         copy_string(lsm.session.name, handle->session_name,
 519                         sizeof(lsm.session.name));
 520
 521         return ask_sessiond(&lsm, NULL);
 522 }
 523
 524 /*
 525  * Disable event of a channel and domain.
 526  */
 527 int lttng_disable_event(struct lttng_handle *handle, const char *name,
 528                 const char *channel_name)
 529 {
 530         struct lttcomm_session_msg lsm;
 531
 532         if (!handle) {
 533                 return -1;
 534         }
 535
 536         if (channel_name) {
 537                 copy_string(lsm.u.disable.channel_name, channel_name,
 538                                 sizeof(lsm.u.disable.channel_name));
 539         } else {
 540                 copy_string(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME,
 541                                 sizeof(lsm.u.disable.channel_name));
 542         }
 543
 544         copy_lttng_domain(&lsm.domain, &handle->domain);
 545
 546         if (name != NULL) {
 547                 copy_string(lsm.u.disable.name, name, sizeof(lsm.u.disable.name));
 548                 lsm.cmd_type = LTTNG_DISABLE_EVENT;
 549         } else {
 550                 lsm.cmd_type = LTTNG_DISABLE_ALL_EVENT;
 551         }
 552
 553         copy_string(lsm.session.name, handle->session_name,
 554                         sizeof(lsm.session.name));
 555
 556         return ask_sessiond(&lsm, NULL);
 557 }
 558
 559 /*
 560  * Enable channel per domain
 561  */
 562 int lttng_enable_channel(struct lttng_handle *handle,
 563                 struct lttng_channel *chan)
 564 {
 565         struct lttcomm_session_msg lsm;
 566
 567         if (!handle) {
 568                 return -1;
 569         }
 570
 571         if (chan) {
 572                 memcpy(&lsm.u.channel.chan, chan, sizeof(lsm.u.channel.chan));
 573         }
 574
 575         lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
 576
 577         copy_lttng_domain(&lsm.domain, &handle->domain);
 578
 579         copy_string(lsm.session.name, handle->session_name,
 580                         sizeof(lsm.session.name));
 581
 582         return ask_sessiond(&lsm, NULL);
 583 }
 584
 585 /*
 586  * All tracing will be stopped for registered events of the channel.
 587  */
 588 int lttng_disable_channel(struct lttng_handle *handle, const char *name)
 589 {
 590         struct lttcomm_session_msg lsm;
 591
 592         if (!handle) {
 593                 return -1;
 594         }
 595
 596         if (name) {
 597                 copy_string(lsm.u.disable.channel_name, name,
 598                                 sizeof(lsm.u.disable.channel_name));
 599         }
 600
 601         lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
 602
 603         copy_lttng_domain(&lsm.domain, &handle->domain);
 604
 605         copy_string(lsm.session.name, handle->session_name,
 606                         sizeof(lsm.session.name));
 607
 608         return ask_sessiond(&lsm, NULL);
 609 }
 610
 611 /*
 612  * List all available tracepoints of domain.
 613  *
 614  * Return the size (bytes) of the list and set the events array.
 615  * On error, return negative value.
 616  */
 617 int lttng_list_tracepoints(struct lttng_handle *handle,
 618                 struct lttng_event **events)
 619 {
 620         int ret;
 621         struct lttcomm_session_msg lsm;
 622
 623         if (!handle) {
 624                 return -1;
 625         }
 626
 627         lsm.cmd_type = LTTNG_LIST_TRACEPOINTS;
 628         copy_lttng_domain(&lsm.domain, &handle->domain);
 629
 630         ret = ask_sessiond(&lsm, (void **) events);
 631         if (ret < 0) {
 632                 return ret;
 633         }
 634
 635         return ret / sizeof(struct lttng_event);
 636 }
 637
 638 /*
 639  *  Return a human readable string of code
 640  */
 641 const char *lttng_strerror(int code)
 642 {
 643         if (code > -LTTCOMM_OK) {
 644                 return "Ended with errors";
 645         }
 646
 647         return lttcomm_get_readable_code(code);
 648 }
 649
 650 /*
 651  *  Create a brand new session using name.
 652  */
 653 int lttng_create_session(const char *name, const char *path)
 654 {
 655         struct lttcomm_session_msg lsm;
 656
 657         lsm.cmd_type = LTTNG_CREATE_SESSION;
 658         copy_string(lsm.session.name, name, sizeof(lsm.session.name));
 659         copy_string(lsm.session.path, path, sizeof(lsm.session.path));
 660
 661         return ask_sessiond(&lsm, NULL);
 662 }
 663
 664 /*
 665  *  Destroy session using name.
 666  */
 667 int lttng_destroy_session(struct lttng_handle *handle)
 668 {
 669         struct lttcomm_session_msg lsm;
 670
 671         if (!handle) {
 672                 return -1;
 673         }
 674
 675         lsm.cmd_type = LTTNG_DESTROY_SESSION;
 676         copy_string(lsm.session.name, handle->session_name,
 677                         sizeof(lsm.session.name));
 678
 679         return ask_sessiond(&lsm, NULL);
 680 }
 681
 682 /*
 683  *  Ask the session daemon for all available sessions.
 684  *
 685  *  Return number of session.
 686  *  On error, return negative value.
 687  */
 688 int lttng_list_sessions(struct lttng_session **sessions)
 689 {
 690         int ret;
 691         struct lttcomm_session_msg lsm;
 692
 693         lsm.cmd_type = LTTNG_LIST_SESSIONS;
 694         ret = ask_sessiond(&lsm, (void**) sessions);
 695         if (ret < 0) {
 696                 return ret;
 697         }
 698
 699         return ret / sizeof(struct lttng_session);
 700 }
 701
 702 /*
 703  * List domain of a session.
 704  */
 705 int lttng_list_domains(struct lttng_handle *handle,
 706                 struct lttng_domain **domains)
 707 {
 708         int ret;
 709         struct lttcomm_session_msg lsm;
 710
 711         if (!handle) {
 712                 return -1;
 713         }
 714
 715         lsm.cmd_type = LTTNG_LIST_DOMAINS;
 716
 717         copy_string(lsm.session.name, handle->session_name,
 718                         sizeof(lsm.session.name));
 719
 720         ret = ask_sessiond(&lsm, (void**) domains);
 721         if (ret < 0) {
 722                 return ret;
 723         }
 724
 725         return ret / sizeof(struct lttng_domain);
 726 }
 727
 728 /*
 729  * List channels of a session
 730  */
 731 int lttng_list_channels(struct lttng_handle *handle,
 732                 struct lttng_channel **channels)
 733 {
 734         int ret;
 735         struct lttcomm_session_msg lsm;
 736
 737         if (!handle) {
 738                 return -1;
 739         }
 740
 741         lsm.cmd_type = LTTNG_LIST_CHANNELS;
 742         copy_string(lsm.session.name, handle->session_name,
 743                         sizeof(lsm.session.name));
 744
 745         copy_lttng_domain(&lsm.domain, &handle->domain);
 746
 747         ret = ask_sessiond(&lsm, (void**) channels);
 748         if (ret < 0) {
 749                 return ret;
 750         }
 751
 752         return ret / sizeof(struct lttng_channel);
 753 }
 754
 755 /*
 756  * List events of a session channel.
 757  */
 758 int lttng_list_events(struct lttng_handle *handle,
 759                 const char *channel_name, struct lttng_event **events)
 760 {
 761         int ret;
 762         struct lttcomm_session_msg lsm;
 763
 764         if (!handle) {
 765                 return -1;
 766         }
 767
 768         lsm.cmd_type = LTTNG_LIST_EVENTS;
 769         copy_string(lsm.session.name, handle->session_name,
 770                         sizeof(lsm.session.name));
 771         copy_string(lsm.u.list.channel_name, channel_name,
 772                         sizeof(lsm.u.list.channel_name));
 773
 774         copy_lttng_domain(&lsm.domain, &handle->domain);
 775
 776         ret = ask_sessiond(&lsm, (void**) events);
 777         if (ret < 0) {
 778                 return ret;
 779         }
 780
 781         return ret / sizeof(struct lttng_event);
 782 }
 783
 784 /*
 785  *  lttng_set_tracing_group
 786  *
 787  *  Set tracing group variable with name. This function
 788  *  allocate memory pointed by tracing_group.
 789  */
 790 int lttng_set_tracing_group(const char *name)
 791 {
 792         if (asprintf(&tracing_group, "%s", name) < 0) {
 793                 return -ENOMEM;
 794         }
 795
 796         return 0;
 797 }
 798
 799 /*
 800  *  lttng_calibrate
 801  */
 802 int lttng_calibrate(struct lttng_handle *handle,
 803                 struct lttng_calibrate *calibrate)
 804 {
 805         struct lttcomm_session_msg lsm;
 806
 807         if (!handle) {
 808                 return -1;
 809         }
 810
 811         lsm.cmd_type = LTTNG_CALIBRATE;
 812         copy_lttng_domain(&lsm.domain, &handle->domain);
 813
 814         memcpy(&lsm.u.calibrate, calibrate, sizeof(lsm.u.calibrate));
 815
 816         return ask_sessiond(&lsm, NULL);
 817 }
 818
 819 /*
 820  * Check if session daemon is alive.
 821  *
 822  * Return 1 if alive or 0 if not.
 823  * On error return -1
 824  */
 825 int lttng_session_daemon_alive(void)
 826 {
 827         int ret;
 828
 829         ret = set_session_daemon_path();
 830         if (ret < 0) {
 831                 /* Error */
 832                 return ret;
 833         }
 834
 835         if (strlen(sessiond_sock_path) == 0) {
 836                 /* No socket path set. Weird error */
 837                 return -1;
 838         }
 839
 840         ret = try_connect_sessiond(sessiond_sock_path);
 841         if (ret < 0) {
 842                 /* Not alive */
 843                 return 0;
 844         }
 845
 846         /* Is alive */
 847         return 1;
 848 }
 849
 850 /*
 851  * lib constructor
 852  */
 853 static void __attribute__((constructor)) init()
 854 {
 855         /* Set default session group */
 856         lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP);
 857 }