lttctl/lttctl.c

   1 /* lttctl
   2  *
   3  * Linux Trace Toolkit Control
   4  *
   5  * Small program that controls LTTng through liblttctl.
   6  *
   7  * Copyright 2008 FUJITSU
   8  *      Zhao Lei <zhaolei@cn.fujitsu.com>
   9  *      Gui Jianfeng <guijianfeng@cn.fujitsu.com>
  10  * Copyright 2009-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along
  23  * with this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include <config.h>
  29 #endif
  30
  31 #include <liblttctl/lttctl.h>
  32 #include <errno.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <sys/wait.h>
  36 #include <unistd.h>
  37 #include <string.h>
  38 #include <limits.h>
  39 #define _GNU_SOURCE
  40 #include <getopt.h>
  41
  42 #define OPT_MAX                 (1024)
  43 #define OPT_NAMELEN             (256)
  44 #define OPT_VALSTRINGLEN        (256)
  45
  46 enum opt_type {
  47         CHANNEL,
  48 };
  49
  50 struct channel_option {
  51         char chan_name[OPT_NAMELEN];
  52         int enable;
  53         int overwrite;
  54         int bufnum;
  55         int bufsize;
  56         int switch_timer;
  57 };
  58
  59 struct lttctl_option {
  60         union {
  61                 struct channel_option chan_opt;
  62         } opt_mode;
  63         enum opt_type type;
  64         struct lttctl_option *next;
  65 };
  66
  67 struct lttctl_option *opt_head, *last_opt;
  68
  69 static int opt_create;
  70 static int opt_destroy;
  71 static int opt_start;
  72 static int opt_pause;
  73 static int opt_help;
  74 static const char *opt_transport;
  75 static const char *opt_write;
  76 static int opt_append;
  77 static unsigned int opt_dump_threads;
  78 static char channel_root_default[PATH_MAX];
  79 static const char *opt_channel_root;
  80 static const char *opt_tracename;
  81
  82 /* Args :
  83  *
  84  */
  85 static void show_arguments(void)
  86 {
  87         printf("Linux Trace Toolkit Trace Control " VERSION"\n");
  88         printf("\n");
  89         printf("Usage: lttctl [OPTION]... [TRACENAME]\n");
  90         printf("\n");
  91         printf("Examples:\n");
  92         printf("  lttctl -c trace1                 "
  93                 "# Create a trace named trace1.\n");
  94         printf("  lttctl -s trace1                 "
  95                 "# start a trace named trace1.\n");
  96         printf("  lttctl -p trace1                 "
  97                 "# pause a trace named trace1.\n");
  98         printf("  lttctl -d trace1                 "
  99                 "# Destroy a trace named trace1.\n");
 100         printf("  lttctl -C -w /tmp/trace1 trace1  "
 101                 "# Create a trace named trace1, start it and\n"
 102                 "                                   "
 103                 "# write non-overwrite channels' data to\n"
 104                 "                                   "
 105                 "# /tmp/trace1, debugfs must be mounted for\n"
 106                 "                                   "
 107                 "# auto-find\n");
 108         printf("  lttctl -D -w /tmp/trace1 trace1  "
 109                 "# Pause and destroy a trace named trace1 and\n"
 110                 "                                   "
 111                 "# write overwrite channels' data to\n"
 112                 "                                   "
 113                 "# /tmp/trace1, debugfs must be mounted for\n"
 114                 "                                   "
 115                 "# auto-find\n");
 116         printf("\n");
 117         printf(" Basic options:\n");
 118         printf("  -c, --create\n");
 119         printf("        Create a trace.\n");
 120         printf("  -d, --destroy\n");
 121         printf("        Destroy a trace.\n");
 122         printf("  -s, --start\n");
 123         printf("        Start a trace.\n");
 124         printf("  -p, --pause\n");
 125         printf("        Pause a trace.\n");
 126         printf("  -h, --help\n");
 127         printf("        Show this help.\n");
 128         printf("\n");
 129         printf(" Advanced options:\n");
 130         printf("  --transport TRANSPORT\n");
 131         printf("        Set trace's transport. (ex. relay-locked or relay)\n");
 132         printf("  -o, --option OPTION\n");
 133         printf("        Set options, following operations are supported:\n");
 134         printf("        channel.<channelname>.enable=\n");
 135         printf("        channel.<channelname>.overwrite=\n");
 136         printf("        channel.<channelname>.bufnum=\n");
 137         printf("        channel.<channelname>.bufsize= (in bytes, rounded to "
 138                "next power of 2)\n");
 139         printf("        <channelname> can be set to all for all channels\n");
 140         printf("        channel.<channelname>.switch_timer= (timer interval in "
 141                "ms)\n");
 142         printf("\n");
 143         printf(" Integration options:\n");
 144         printf("  -C, --create_start\n");
 145         printf("        Create and start a trace.\n");
 146         printf("  -D, --pause_destroy\n");
 147         printf("        Pause and destroy a trace.\n");
 148         printf("  -w, --write PATH\n");
 149         printf("        Path for write trace datas.\n");
 150         printf("        For -c, -C, -d, -D options\n");
 151         printf("  -a, --append\n");
 152         printf("        Append to trace, For -w option\n");
 153         printf("  -n, --dump_threads NUMBER\n");
 154         printf("        Number of lttd threads, For -w option\n");
 155         printf("  --channel_root PATH\n");
 156         printf("        Set channels root path, For -w option."
 157                 " (ex. /mnt/debugfs/ltt)\n");
 158         printf("\n");
 159         printf(" Environment variables:\n");
 160         printf("  LTT_DAEMON\n");
 161         printf("       Complete path to the lttd binary (needs to be\n");
 162         printf("       specified if different than package build prefix).\n");
 163         printf("\n");
 164 }
 165
 166 /*
 167  * Separate option name to 3 fields
 168  * Ex:
 169  *  Input: name = channel.cpu.bufsize
 170  *  Output: name1 = channel
 171  *          name2 = cpu
 172  *          name3 = bufsize
 173  *  Ret: 0 on success
 174  *       1 on fail
 175  *
 176  * Note:
 177  *  Make sure that name1~3 longer than OPT_NAMELEN.
 178  *  name1~3 can be NULL to discard value
 179  *
 180  */
 181 static int separate_opt(const char *name, char *name1, char *name2, char *name3)
 182 {
 183         char *p;
 184
 185         if (!name)
 186                 return 1;
 187
 188         /* segment1 */
 189         p = strchr(name, '.');
 190         if (!p)
 191                 return 1;
 192         if (p - name >= OPT_NAMELEN)
 193                 return 1;
 194         if (name1) {
 195                 memcpy(name1, name, p - name);
 196                 name1[p - name] = 0;
 197         }
 198         name = p + 1;
 199
 200         /* segment2 */
 201         p = strchr(name, '.');
 202         if (!p)
 203                 return 1;
 204         if (p - name >= OPT_NAMELEN)
 205                 return 1;
 206         if (name2) {
 207                 memcpy(name2, name, p - name);
 208                 name2[p - name] = 0;
 209         }
 210         name = p + 1;
 211
 212         /* segment3 */
 213         if (strlen(name) >= OPT_NAMELEN)
 214                 return 1;
 215         if (name3)
 216                 strcpy(name3, name);
 217
 218         return 0;
 219 }
 220
 221 static void init_channel_opt(struct channel_option *opt, char *opt_name)
 222 {
 223         if (opt && opt_name) {
 224                 opt->enable = -1;
 225                 opt->overwrite = -1;
 226                 opt->bufnum = -1;
 227                 opt->bufsize = -1;
 228                 opt->switch_timer = -1;
 229                 strcpy(opt->chan_name, opt_name);
 230         }
 231 }
 232
 233 static struct lttctl_option *find_insert_channel_opt(char *opt_name)
 234 {
 235         struct lttctl_option *iter, *new_opt;
 236
 237         if (!opt_head) {
 238                 opt_head = (struct lttctl_option *)malloc(sizeof(struct lttctl_option));
 239                 init_channel_opt(&opt_head->opt_mode.chan_opt, opt_name);
 240                 opt_head->type = CHANNEL;
 241                 opt_head->next = NULL;
 242                 last_opt = opt_head;
 243                 return opt_head;
 244         }
 245
 246         for (iter = opt_head; iter; iter = iter->next) {
 247                 if (iter->type != CHANNEL)
 248                         continue;
 249                 if (!strcmp(iter->opt_mode.chan_opt.chan_name, opt_name))
 250                         return iter;
 251         }
 252
 253         new_opt = (struct lttctl_option *)malloc(sizeof(struct lttctl_option));
 254         init_channel_opt(&new_opt->opt_mode.chan_opt, opt_name);
 255         new_opt->type = CHANNEL;
 256         new_opt->next = NULL;
 257         last_opt->next = new_opt;
 258         last_opt = new_opt;
 259         return new_opt;
 260 }
 261
 262 int set_channel_opt(struct channel_option *opt, char *opt_name, char *opt_valstr)
 263 {
 264         int opt_val, ret;
 265
 266         if (!strcmp("enable", opt_name)) {
 267                 if (opt_valstr[1] != 0) {
 268                         return -EINVAL;
 269                 }
 270                 if (opt_valstr[0] == 'Y' || opt_valstr[0] == 'y'
 271                     || opt_valstr[0] == '1')
 272                         opt_val = 1;
 273                 else if (opt_valstr[0] == 'N' || opt_valstr[0] == 'n'
 274                          || opt_valstr[0] == '0')
 275                         opt_val = 0;
 276                 else {
 277                         return -EINVAL;
 278                 }
 279
 280                 opt->enable = opt_val;
 281                 return 0;
 282         } else if (!strcmp("overwrite", opt_name)) {
 283                 if (opt_valstr[1] != 0) {
 284                         return -EINVAL;
 285                 }
 286                 if (opt_valstr[0] == 'Y' || opt_valstr[0] == 'y'
 287                     || opt_valstr[0] == '1')
 288                         opt_val = 1;
 289                 else if (opt_valstr[0] == 'N' || opt_valstr[0] == 'n'
 290                          || opt_valstr[0] == '0')
 291                         opt_val = 0;
 292                 else {
 293                         return -EINVAL;
 294                 }
 295
 296                 opt->overwrite = opt_val;
 297                 return 0;
 298
 299         } else if (!strcmp("bufnum", opt_name)) {
 300                 ret = sscanf(opt_valstr, "%d", &opt_val);
 301                 if (ret != 1 || opt_val < 0) {
 302                         return -EINVAL;
 303                 }
 304
 305                 opt->bufnum = opt_val;
 306                 return 0;
 307         } else if (!strcmp("bufsize", opt_name)) {
 308                 ret = sscanf(opt_valstr, "%d", &opt_val);
 309                 if (ret != 1 || opt_val < 0) {
 310                         return -EINVAL;
 311                 }
 312
 313                 opt->bufsize = opt_val;
 314                 return 0;
 315         } else if (!strcmp("switch_timer", opt_name)) {
 316                 ret = sscanf(opt_valstr, "%d", &opt_val);
 317                 if (ret != 1 || opt_val < 0) {
 318                         return -EINVAL;
 319                 }
 320
 321                 opt->switch_timer = opt_val;
 322                 return 0;
 323         } else {
 324                 return -EINVAL;
 325         }
 326
 327 }
 328
 329 static int parst_opt(const char *optarg)
 330 {
 331         int ret;
 332         char opt_name[OPT_NAMELEN * 3];
 333         char opt_valstr[OPT_VALSTRINGLEN];
 334         char *p;
 335
 336         char name1[OPT_NAMELEN];
 337         char name2[OPT_NAMELEN];
 338         char name3[OPT_NAMELEN];
 339
 340         int opt_intval;
 341         int opt_val;
 342         unsigned int opt_uintval;
 343         struct lttctl_option *opt;
 344
 345         if (!optarg) {
 346                 fprintf(stderr, "Option empty\n");
 347                 return -EINVAL;
 348         }
 349
 350         /* Get option name and val_str */
 351         p = strchr(optarg, '=');
 352         if (!p) {
 353                 fprintf(stderr, "Option format error: %s\n", optarg);
 354                 return -EINVAL;
 355         }
 356
 357         if (p - optarg >= sizeof(opt_name)/sizeof(opt_name[0])) {
 358                 fprintf(stderr, "Option name too long: %s\n", optarg);
 359                 return -EINVAL;
 360         }
 361
 362         if (strlen(p+1) >= OPT_VALSTRINGLEN) {
 363                 fprintf(stderr, "Option value too long: %s\n", optarg);
 364                 return -EINVAL;
 365         }
 366
 367         memcpy(opt_name, optarg, p - optarg);
 368         opt_name[p - optarg] = 0;
 369         strcpy(opt_valstr, p+1);
 370
 371         /* separate option name into 3 fields */
 372         ret = separate_opt(opt_name, name1, name2, name3);
 373         if (ret != 0) {
 374                 fprintf(stderr, "Option name error1: %s\n", optarg);
 375                 return -EINVAL;
 376         }
 377
 378         if (!strcmp("channel", name1)) {
 379                 opt = find_insert_channel_opt(name2);
 380                 if ((ret = set_channel_opt(&opt->opt_mode.chan_opt,
 381                                            name3, opt_valstr) != 0)) {
 382                         fprintf(stderr, "Option name error2: %s\n", optarg);
 383                         return ret;
 384                 }
 385         } else {
 386                 fprintf(stderr, "Option name error3: %s\n", optarg);
 387                 return -EINVAL;
 388         }
 389
 390         return 0;
 391 }
 392
 393 /* parse_arguments
 394  *
 395  * Parses the command line arguments.
 396  *
 397  * Returns -1 if the arguments were correct, but doesn't ask for program
 398  * continuation. Returns EINVAL if the arguments are incorrect, or 0 if OK.
 399  */
 400 static int parse_arguments(int argc, char **argv)
 401 {
 402         int ret = 0;
 403
 404         static struct option longopts[] = {
 405                 {"create",              no_argument,            NULL,   'c'},
 406                 {"destroy",             no_argument,            NULL,   'd'},
 407                 {"start",               no_argument,            NULL,   's'},
 408                 {"pause",               no_argument,            NULL,   'p'},
 409                 {"help",                no_argument,            NULL,   'h'},
 410                 {"transport",           required_argument,      NULL,   2},
 411                 {"option",              required_argument,      NULL,   'o'},
 412                 {"create_start",        no_argument,            NULL,   'C'},
 413                 {"pause_destroy",       no_argument,            NULL,   'D'},
 414                 {"write",               required_argument,      NULL,   'w'},
 415                 {"append",              no_argument,            NULL,   'a'},
 416                 {"dump_threads",        required_argument,      NULL,   'n'},
 417                 {"channel_root",        required_argument,      NULL,   3},
 418                 { NULL,                 0,                      NULL,   0 },
 419         };
 420
 421         /*
 422          * Enable all channels in default
 423          * To make novice users happy
 424          */
 425         parst_opt("channel.all.enable=1");
 426
 427         opterr = 1; /* Print error message on getopt_long */
 428         while (1) {
 429                 int c;
 430                 c = getopt_long(argc, argv, "cdspho:CDw:an:", longopts, NULL);
 431                 if (-1 == c) {
 432                         /* parse end */
 433                         break;
 434                 }
 435                 switch (c) {
 436                 case 'c':
 437                         opt_create = 1;
 438                         break;
 439                 case 'd':
 440                         opt_destroy = 1;
 441                         break;
 442                 case 's':
 443                         opt_start = 1;
 444                         break;
 445                 case 'p':
 446                         opt_pause = 1;
 447                         break;
 448                 case 'h':
 449                         opt_help = 1;
 450                         break;
 451                 case 2:
 452                         if (!opt_transport) {
 453                                 opt_transport = optarg;
 454                         } else {
 455                                 fprintf(stderr,
 456                                         "Please specify only 1 transport\n");
 457                                 return -EINVAL;
 458                         }
 459                         break;
 460                 case 'o':
 461                         ret = parst_opt(optarg);
 462                         if (ret)
 463                                 return ret;
 464                         break;
 465                 case 'C':
 466                         opt_create = 1;
 467                         opt_start = 1;
 468                         break;
 469                 case 'D':
 470                         opt_pause = 1;
 471                         opt_destroy = 1;
 472                         break;
 473                 case 'w':
 474                         if (!opt_write) {
 475                                 opt_write = optarg;
 476                         } else {
 477                                 fprintf(stderr,
 478                                         "Please specify only 1 write dir\n");
 479                                 return -EINVAL;
 480                         }
 481                         break;
 482                 case 'a':
 483                         opt_append = 1;
 484                         break;
 485                 case 'n':
 486                         if (opt_dump_threads) {
 487                                 fprintf(stderr,
 488                                         "Please specify only 1 dump threads\n");
 489                                 return -EINVAL;
 490                         }
 491
 492                         ret = sscanf(optarg, "%u", &opt_dump_threads);
 493                         if (ret != 1) {
 494                                 fprintf(stderr,
 495                                         "Dump threads not positive number\n");
 496                                 return -EINVAL;
 497                         }
 498                         break;
 499                 case 3:
 500                         if (!opt_channel_root) {
 501                                 opt_channel_root = optarg;
 502                         } else {
 503                                 fprintf(stderr,
 504                                         "Please specify only 1 channel root\n");
 505                                 return -EINVAL;
 506                         }
 507                         break;
 508                 case '?':
 509                         return -EINVAL;
 510                 default:
 511                         break;
 512                 };
 513         };
 514
 515         /* Don't check args when user needs help */
 516         if (opt_help)
 517                 return 0;
 518
 519         /* Get tracename */
 520         if (optind < argc - 1) {
 521                 fprintf(stderr, "Please specify only 1 trace name\n");
 522                 return -EINVAL;
 523         }
 524         if (optind > argc - 1) {
 525                 fprintf(stderr, "Please specify trace name\n");
 526                 return -EINVAL;
 527         }
 528         opt_tracename = argv[optind];
 529
 530         /*
 531          * Check arguments
 532          */
 533         if (!opt_create && !opt_start && !opt_destroy && !opt_pause) {
 534                 fprintf(stderr,
 535                         "Please specify a option of "
 536                         "create, destroy, start, or pause\n");
 537                 return -EINVAL;
 538         }
 539
 540         if ((opt_create || opt_start) && (opt_destroy || opt_pause)) {
 541                 fprintf(stderr,
 542                         "Create and start conflict with destroy and pause\n");
 543                 return -EINVAL;
 544         }
 545
 546         if (opt_create) {
 547                 if (!opt_transport)
 548                         opt_transport = "relay";
 549         }
 550
 551         if (opt_transport) {
 552                 if (!opt_create) {
 553                         fprintf(stderr,
 554                                 "Transport option must be combine with create"
 555                                 " option\n");
 556                         return -EINVAL;
 557                 }
 558         }
 559
 560         if (opt_write) {
 561                 if (!opt_create && !opt_destroy) {
 562                         fprintf(stderr,
 563                                 "Write option must be combine with create or"
 564                                 " destroy option\n");
 565                         return -EINVAL;
 566                 }
 567
 568                 if (!opt_channel_root)
 569                         if (getdebugfsmntdir(channel_root_default) == 0) {
 570                                 strcat(channel_root_default, "/ltt");
 571                                 opt_channel_root = channel_root_default;
 572                         } else {
 573                                 fprintf(stderr,
 574                                         "Channel_root is necessary for -w"
 575                                         " option, but neither --channel_root"
 576                                         " option\n"
 577                                         "specified, nor debugfs's mount dir"
 578                                         " found, mount debugfs also failed\n");
 579                                 return -EINVAL;
 580                         }
 581
 582                 if (opt_dump_threads == 0)
 583                         opt_dump_threads = 1;
 584         }
 585
 586         if (opt_append) {
 587                 if (!opt_write) {
 588                         fprintf(stderr,
 589                                 "Append option must be combine with write"
 590                                 " option\n");
 591                         return -EINVAL;
 592                 }
 593         }
 594
 595         if (opt_dump_threads) {
 596                 if (!opt_write) {
 597                         fprintf(stderr,
 598                                 "Dump_threads option must be combine with write"
 599                                 " option\n");
 600                         return -EINVAL;
 601                 }
 602         }
 603
 604         if (opt_channel_root) {
 605                 if (!opt_write) {
 606                         fprintf(stderr,
 607                                 "Channel_root option must be combine with write"
 608                                 " option\n");
 609                         return -EINVAL;
 610                 }
 611         }
 612
 613         return 0;
 614 }
 615
 616 static void show_info(void)
 617 {
 618         printf("Linux Trace Toolkit Trace Control " VERSION"\n");
 619         printf("\n");
 620         if (opt_tracename != NULL) {
 621                 printf("Controlling trace : %s\n", opt_tracename);
 622                 printf("\n");
 623         }
 624 }
 625
 626 static int lttctl_channel_setup(struct channel_option *opt)
 627 {
 628         int ret;
 629
 630         if (opt->enable != -1) {
 631                 if ((ret = lttctl_set_channel_enable(opt_tracename,
 632                                                      opt->chan_name,
 633                                                      opt->enable)) != 0)
 634                         return ret;
 635         }
 636         if (opt->overwrite != -1) {
 637                 if ((ret = lttctl_set_channel_overwrite(opt_tracename,
 638                                                         opt->chan_name,
 639                                                         opt->overwrite)) != 0)
 640                         return ret;
 641         }
 642         if (opt->bufnum != -1) {
 643                 if ((ret = lttctl_set_channel_subbuf_num(opt_tracename,
 644                                                          opt->chan_name,
 645                                                          opt->bufnum)) != 0)
 646                         return ret;
 647         }
 648         if (opt->bufsize != -1) {
 649                 if ((ret = lttctl_set_channel_subbuf_size(opt_tracename,
 650                                                           opt->chan_name,
 651                                                           opt->bufsize)) != 0)
 652                         return ret;
 653         }
 654         if (opt->switch_timer != -1) {
 655                 if ((ret = lttctl_set_channel_switch_timer(opt_tracename,
 656                                 opt->chan_name, opt->switch_timer)) != 0)
 657                         return ret;
 658         }
 659
 660         return 0;
 661 }
 662
 663 static int lttctl_create_trace(void)
 664 {
 665         int ret;
 666         int i;
 667         struct lttctl_option *opt;
 668
 669         ret = lttctl_setup_trace(opt_tracename);
 670         if (ret)
 671                 goto setup_trace_fail;
 672
 673         for (opt = opt_head; opt; opt = opt->next) {
 674                 if (opt->type != CHANNEL)
 675                         continue;
 676                 ret = lttctl_channel_setup(&opt->opt_mode.chan_opt);
 677                 if (ret)
 678                         goto set_option_fail;;
 679         }
 680
 681         ret = lttctl_set_trans(opt_tracename, opt_transport);
 682         if (ret)
 683                 goto set_option_fail;
 684
 685         ret = lttctl_alloc_trace(opt_tracename);
 686         if (ret)
 687                 goto alloc_trace_fail;
 688
 689         return 0;
 690
 691 alloc_trace_fail:
 692 set_option_fail:
 693         lttctl_destroy_trace(opt_tracename);
 694 setup_trace_fail:
 695         return ret;
 696 }
 697
 698 /*
 699  * Start a lttd daemon to write trace data
 700  * Dump overwrite channels on overwrite!=0
 701  * Dump normal(non-overwrite) channels on overwrite=0
 702  *
 703  * When called for overwrite mode, wait for lttd to return, so we are sure that
 704  * trace session teardown is not executed before lttd can grab the buffer data.
 705  *
 706  * ret: 0 on success
 707  *      !0 on fail
 708  */
 709 static int lttctl_daemon(int overwrite)
 710 {
 711         pid_t pid;
 712         int status;
 713
 714         pid = fork();
 715         if (pid < 0) {
 716                 perror("Error in forking for lttd daemon");
 717                 return errno;
 718         }
 719
 720         if (pid == 0) {
 721                 /* child */
 722                 char *argv[16];
 723                 int argc = 0;
 724                 char channel_path[PATH_MAX];
 725                 char thread_num[16];
 726
 727                 /* prog path */
 728                 argv[argc] = getenv("LTT_DAEMON");
 729                 if (argv[argc] == NULL)
 730                         argv[argc] = PACKAGE_BIN_DIR "/lttd";
 731                 argc++;
 732
 733                 /* -t option */
 734                 argv[argc] = "-t";
 735                 argc++;
 736                 /*
 737                  * we allow modify of opt_write's content in new process
 738                  * for get rid of warning of assign char * to const char *
 739                  */
 740                 argv[argc] = (char *)opt_write;
 741                 argc++;
 742
 743                 /* -c option */
 744                 strcpy(channel_path, opt_channel_root);
 745                 strcat(channel_path, "/");
 746                 strcat(channel_path, opt_tracename);
 747                 argv[argc] = "-c";
 748                 argc++;
 749                 argv[argc] = channel_path;
 750                 argc++;
 751
 752                 /* -N option */
 753                 sprintf(thread_num, "%u", opt_dump_threads);
 754                 argv[argc] = "-N";
 755                 argc++;
 756                 argv[argc] = thread_num;
 757                 argc++;
 758
 759                 /* -a option */
 760                 if (opt_append) {
 761                         argv[argc] = "-a";
 762                         argc++;
 763                 }
 764
 765                 /* -d option */
 766                 argv[argc] = "-d";
 767                 argc++;
 768
 769                 /* overwrite option */
 770                 if (overwrite) {
 771                         argv[argc] = "-f";
 772                         argc++;
 773                 } else {
 774                         argv[argc] = "-n";
 775                         argc++;
 776                 }
 777
 778                 argv[argc] = NULL;
 779
 780                 execvp(argv[0], argv);
 781
 782                 perror("Error in executing the lttd daemon");
 783                 exit(errno);
 784         }
 785
 786         /* parent */
 787         if (waitpid(pid, &status, 0) == -1) {
 788                 perror("Error in waitpid\n");
 789                 return errno;
 790         }
 791
 792         if (!WIFEXITED(status)) {
 793                 fprintf(stderr, "lttd process interrupted\n");
 794                 return status;
 795         }
 796
 797         if (WEXITSTATUS(status))
 798                 fprintf(stderr, "lttd process running failed\n");
 799
 800         /*
 801          * FIXME
 802          * This is a temporary hack to ensure that the lttd daemon grabs
 803          * handles on the debugfs buffer files before we destroy the trace
 804          * session. Properly handling this will imply separating the "flush"
 805          * from the "destroy" operation at kernel-level in LTTng.
 806          */
 807         if (overwrite)
 808                 sleep(2);
 809
 810         return WEXITSTATUS(status);
 811 }
 812
 813 int main(int argc, char **argv)
 814 {
 815         int ret;
 816
 817         ret = parse_arguments(argc, argv);
 818         /* If user needs show help, we disregard other options */
 819         if (opt_help) {
 820                 show_arguments();
 821                 return 0;
 822         }
 823
 824         /* exit program if arguments wrong */
 825         if (ret)
 826                 return 1;
 827
 828         show_info();
 829
 830         ret = lttctl_init();
 831         if (ret != 0)
 832                 return ret;
 833
 834         if (opt_create) {
 835                 printf("lttctl: Creating trace\n");
 836                 ret = lttctl_create_trace();
 837                 if (ret)
 838                         goto op_fail;
 839
 840                 if (opt_write) {
 841                         printf("lttctl: Forking lttd\n");
 842                         ret = lttctl_daemon(0);
 843                         if (ret)
 844                                 goto op_fail;
 845                 }
 846         }
 847
 848         if (opt_start) {
 849                 printf("lttctl: Starting trace\n");
 850                 ret = lttctl_start(opt_tracename);
 851                 if (ret)
 852                         goto op_fail;
 853         }
 854
 855         if (opt_pause) {
 856                 printf("lttctl: Pausing trace\n");
 857                 ret = lttctl_pause(opt_tracename);
 858                 if (ret)
 859                         goto op_fail;
 860         }
 861
 862         if (opt_destroy) {
 863                 if (opt_write) {
 864                         printf("lttctl: Forking lttd\n");
 865                         ret = lttctl_daemon(1);
 866                         if (ret)
 867                                 goto op_fail;
 868                 }
 869
 870                 printf("lttctl: Destroying trace\n");
 871                 ret = lttctl_destroy_trace(opt_tracename);
 872                 if (ret)
 873                         goto op_fail;
 874         }
 875
 876 op_fail:
 877         lttctl_destroy();
 878
 879         return ret;
 880 }