src/bin/lttng/commands/snapshot.c

   1 /*
   2  * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <assert.h>
  20 #include <inttypes.h>
  21 #include <popt.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/stat.h>
  26 #include <sys/types.h>
  27 #include <unistd.h>
  28 #include <assert.h>
  29
  30 #include <common/utils.h>
  31 #include <common/mi-lttng.h>
  32 #include <lttng/snapshot.h>
  33
  34 #include "../command.h"
  35
  36 static const char *opt_session_name;
  37 static const char *opt_output_name;
  38 static const char *opt_data_url;
  39 static const char *opt_ctrl_url;
  40 static const char *current_session_name;
  41 static uint64_t opt_max_size;
  42
  43 /* Stub for the cmd struct actions. */
  44 static int cmd_add_output(int argc, const char **argv);
  45 static int cmd_del_output(int argc, const char **argv);
  46 static int cmd_list_output(int argc, const char **argv);
  47 static int cmd_record(int argc, const char **argv);
  48
  49 static const char *indent4 = "    ";
  50
  51 #ifdef LTTNG_EMBED_HELP
  52 static const char help_msg[] =
  53 #include <lttng-snapshot.1.h>
  54 ;
  55 #endif
  56
  57 enum {
  58         OPT_HELP = 1,
  59         OPT_LIST_OPTIONS,
  60         OPT_MAX_SIZE,
  61         OPT_LIST_COMMANDS,
  62 };
  63
  64 static struct mi_writer *writer;
  65
  66 static struct poptOption snapshot_opts[] = {
  67         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  68         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  69         {"session",      's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  70         {"ctrl-url",     'C', POPT_ARG_STRING, &opt_ctrl_url, 0, 0, 0},
  71         {"data-url",     'D', POPT_ARG_STRING, &opt_data_url, 0, 0, 0},
  72         {"name",         'n', POPT_ARG_STRING, &opt_output_name, 0, 0, 0},
  73         {"max-size",     'm', POPT_ARG_STRING, 0, OPT_MAX_SIZE, 0, 0},
  74         {"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  75         {"list-commands",  0, POPT_ARG_NONE, NULL, OPT_LIST_COMMANDS},
  76         {0, 0, 0, 0, 0, 0, 0}
  77 };
  78
  79 static struct cmd_struct actions[] = {
  80         { "add-output", cmd_add_output },
  81         { "del-output", cmd_del_output },
  82         { "list-output", cmd_list_output },
  83         { "record", cmd_record },
  84         { NULL, NULL }  /* Array closure */
  85 };
  86
  87 /*
  88  * Count and return the number of arguments in argv.
  89  */
  90 static int count_arguments(const char **argv)
  91 {
  92         int i = 0;
  93
  94         assert(argv);
  95
  96         while (argv[i] != NULL) {
  97                 i++;
  98         }
  99
 100         return i;
 101 }
 102
 103 /*
 104  * Create a snapshot output object from arguments using the given URL.
 105  *
 106  * Return a newly allocated object or NULL on error.
 107  */
 108 static struct lttng_snapshot_output *create_output_from_args(const char *url)
 109 {
 110         int ret = 0;
 111         struct lttng_snapshot_output *output = NULL;
 112
 113         output = lttng_snapshot_output_create();
 114         if (!output) {
 115                 goto error_create;
 116         }
 117
 118         if (url) {
 119                 ret = lttng_snapshot_output_set_ctrl_url(url, output);
 120                 if (ret < 0) {
 121                         goto error;
 122                 }
 123         } else if (opt_ctrl_url) {
 124                 ret = lttng_snapshot_output_set_ctrl_url(opt_ctrl_url, output);
 125                 if (ret < 0) {
 126                         goto error;
 127                 }
 128         }
 129
 130         if (opt_data_url) {
 131                 ret = lttng_snapshot_output_set_data_url(opt_data_url, output);
 132                 if (ret < 0) {
 133                         goto error;
 134                 }
 135         }
 136
 137         if (opt_max_size) {
 138                 ret = lttng_snapshot_output_set_size(opt_max_size, output);
 139                 if (ret < 0) {
 140                         goto error;
 141                 }
 142         }
 143
 144         if (opt_output_name) {
 145                 ret = lttng_snapshot_output_set_name(opt_output_name, output);
 146                 if (ret < 0) {
 147                         goto error;
 148                 }
 149         }
 150
 151         return output;
 152
 153 error:
 154         lttng_snapshot_output_destroy(output);
 155 error_create:
 156         return NULL;
 157 }
 158
 159 static int list_output(void)
 160 {
 161         int ret, output_seen = 0;
 162         struct lttng_snapshot_output *s_iter;
 163         struct lttng_snapshot_output_list *list;
 164
 165         ret = lttng_snapshot_list_output(current_session_name, &list);
 166         if (ret < 0) {
 167                 goto error;
 168         }
 169
 170         MSG("Snapshot output list for session %s", current_session_name);
 171
 172         if (lttng_opt_mi) {
 173                 ret = mi_lttng_snapshot_output_session_name(writer,
 174                                 current_session_name);
 175                 if (ret) {
 176                         ret = CMD_ERROR;
 177                         goto end;
 178                 }
 179         }
 180
 181         while ((s_iter = lttng_snapshot_output_list_get_next(list)) != NULL) {
 182                 MSG("%s[%" PRIu32 "] %s: %s (max-size: %" PRId64 ")", indent4,
 183                                 lttng_snapshot_output_get_id(s_iter),
 184                                 lttng_snapshot_output_get_name(s_iter),
 185                                 lttng_snapshot_output_get_ctrl_url(s_iter),
 186                                 lttng_snapshot_output_get_maxsize(s_iter));
 187                 output_seen = 1;
 188                 if (lttng_opt_mi) {
 189                         ret = mi_lttng_snapshot_list_output(writer, s_iter);
 190                         if (ret) {
 191                                 ret = CMD_ERROR;
 192                                 goto end;
 193                         }
 194                 }
 195         }
 196
 197         if (lttng_opt_mi) {
 198                 /* Close snapshot snapshots element */
 199                 ret = mi_lttng_writer_close_element(writer);
 200                 if (ret) {
 201                         ret = CMD_ERROR;
 202                         goto end;
 203                 }
 204
 205                 /* Close snapshot session element */
 206                 ret = mi_lttng_writer_close_element(writer);
 207                 if (ret) {
 208                         ret = CMD_ERROR;
 209                 }
 210         }
 211 end:
 212         lttng_snapshot_output_list_destroy(list);
 213
 214         if (!output_seen) {
 215                 MSG("%sNone", indent4);
 216         }
 217
 218 error:
 219         return ret;
 220 }
 221
 222 /*
 223  * Delete output by ID.
 224  */
 225 static int del_output(uint32_t id, const char *name)
 226 {
 227         int ret;
 228         struct lttng_snapshot_output *output = NULL;
 229
 230         output = lttng_snapshot_output_create();
 231         if (!output) {
 232                 ret = CMD_FATAL;
 233                 goto error;
 234         }
 235
 236         if (name) {
 237                 ret = lttng_snapshot_output_set_name(name, output);
 238         } else if (id != UINT32_MAX) {
 239                 ret = lttng_snapshot_output_set_id(id, output);
 240         } else {
 241                 ret = CMD_ERROR;
 242                 goto error;
 243         }
 244         if (ret < 0) {
 245                 ret = CMD_FATAL;
 246                 goto error;
 247         }
 248
 249         ret = lttng_snapshot_del_output(current_session_name, output);
 250         if (ret < 0) {
 251                 goto error;
 252         }
 253
 254         if (id != UINT32_MAX) {
 255                 MSG("Snapshot output id %" PRIu32 " successfully deleted for session %s",
 256                                 id, current_session_name);
 257         } else {
 258                 MSG("Snapshot output %s successfully deleted for session %s",
 259                                 name, current_session_name);
 260         }
 261
 262         if (lttng_opt_mi) {
 263                 ret = mi_lttng_snapshot_del_output(writer, id, name,
 264                                 current_session_name);
 265                 if (ret) {
 266                         ret = CMD_ERROR;
 267                 }
 268         }
 269
 270 error:
 271         lttng_snapshot_output_destroy(output);
 272         return ret;
 273 }
 274
 275 /*
 276  * Add output from the user URL.
 277  */
 278 static int add_output(const char *url)
 279 {
 280         int ret;
 281         struct lttng_snapshot_output *output = NULL;
 282         char name[NAME_MAX];
 283         const char *n_ptr;
 284
 285         if (!url && (!opt_data_url || !opt_ctrl_url)) {
 286                 ret = CMD_ERROR;
 287                 goto error;
 288         }
 289
 290         output = create_output_from_args(url);
 291         if (!output) {
 292                 ret = CMD_FATAL;
 293                 goto error;
 294         }
 295
 296         /* This call, if successful, populates the id of the output object. */
 297         ret = lttng_snapshot_add_output(current_session_name, output);
 298         if (ret < 0) {
 299                 goto error;
 300         }
 301
 302         n_ptr = lttng_snapshot_output_get_name(output);
 303         if (*n_ptr == '\0') {
 304                 int pret;
 305                 pret = snprintf(name, sizeof(name), DEFAULT_SNAPSHOT_NAME "-%" PRIu32,
 306                                 lttng_snapshot_output_get_id(output));
 307                 if (pret < 0) {
 308                         PERROR("snprintf add output name");
 309                 }
 310                 n_ptr = name;
 311         }
 312
 313         MSG("Snapshot output successfully added for session %s",
 314                         current_session_name);
 315         MSG("  [%" PRIu32 "] %s: %s (max-size: %" PRId64 ")",
 316                         lttng_snapshot_output_get_id(output), n_ptr,
 317                         lttng_snapshot_output_get_ctrl_url(output),
 318                         lttng_snapshot_output_get_maxsize(output));
 319         if (lttng_opt_mi) {
 320                 ret = mi_lttng_snapshot_add_output(writer, current_session_name,
 321                                 n_ptr, output);
 322                 if (ret) {
 323                         ret = CMD_ERROR;
 324                 }
 325         }
 326 error:
 327         lttng_snapshot_output_destroy(output);
 328         return ret;
 329 }
 330
 331 static int cmd_add_output(int argc, const char **argv)
 332 {
 333         int ret;
 334
 335         if (argc < 2 && (!opt_data_url || !opt_ctrl_url)) {
 336                 ret = CMD_ERROR;
 337                 goto end;
 338         }
 339
 340         ret = add_output(argv[1]);
 341
 342 end:
 343         return ret;
 344 }
 345
 346 static int cmd_del_output(int argc, const char **argv)
 347 {
 348         int ret;
 349         char *name;
 350         long id;
 351
 352         if (argc < 2) {
 353                 ret = CMD_ERROR;
 354                 goto end;
 355         }
 356
 357         errno = 0;
 358         id = strtol(argv[1], &name, 10);
 359         if (id == 0 && (errno == 0 || errno == EINVAL)) {
 360                 ret = del_output(UINT32_MAX, name);
 361         } else if (errno == 0 && *name == '\0') {
 362                 ret = del_output(id, NULL);
 363         } else {
 364                 ERR("Argument %s not recognized", argv[1]);
 365                 ret = -1;
 366                 goto end;
 367         }
 368
 369 end:
 370         return ret;
 371 }
 372
 373 static int cmd_list_output(int argc, const char **argv)
 374 {
 375         int ret;
 376
 377         ret = list_output();
 378
 379         return ret;
 380 }
 381
 382 /*
 383  * Do a snapshot record with the URL if one is given.
 384  */
 385 static int record(const char *url)
 386 {
 387         int ret;
 388         struct lttng_snapshot_output *output = NULL;
 389
 390         output = create_output_from_args(url);
 391         if (!output) {
 392                 ret = CMD_FATAL;
 393                 goto error;
 394         }
 395
 396         ret = lttng_snapshot_record(current_session_name, output, 0);
 397         if (ret < 0) {
 398                 if (ret == -LTTNG_ERR_MAX_SIZE_INVALID) {
 399                         ERR("Invalid snapshot size. Cannot fit at least one packet per stream.");
 400                 }
 401                 goto error;
 402         }
 403
 404         MSG("Snapshot recorded successfully for session %s", current_session_name);
 405
 406         if (url) {
 407                 MSG("Snapshot written at: %s", url);
 408         } else if (opt_ctrl_url) {
 409                 MSG("Snapshot written to ctrl: %s, data: %s", opt_ctrl_url,
 410                                 opt_data_url);
 411         }
 412
 413         if (lttng_opt_mi) {
 414                 ret = mi_lttng_snapshot_record(writer, current_session_name, url,
 415                                 opt_ctrl_url, opt_data_url);
 416                 if (ret) {
 417                         ret = CMD_ERROR;
 418                 }
 419         }
 420
 421 error:
 422         lttng_snapshot_output_destroy(output);
 423         return ret;
 424 }
 425
 426 static int cmd_record(int argc, const char **argv)
 427 {
 428         int ret;
 429
 430         if (argc == 2) {
 431                 ret = record(argv[1]);
 432         } else {
 433                 ret = record(NULL);
 434         }
 435
 436         return ret;
 437 }
 438
 439 static int handle_command(const char **argv)
 440 {
 441         int ret = CMD_SUCCESS, i = 0, argc, command_ret =  CMD_SUCCESS;
 442         struct cmd_struct *cmd;
 443
 444         if (argv == NULL || (!opt_ctrl_url && opt_data_url) ||
 445                         (opt_ctrl_url && !opt_data_url)) {
 446                 command_ret = CMD_ERROR;
 447                 goto end;
 448         }
 449
 450         argc = count_arguments(argv);
 451
 452         cmd = &actions[i];
 453         while (cmd->func != NULL) {
 454                 /* Find command */
 455                 if (strcmp(argv[0], cmd->name) == 0) {
 456                         if (lttng_opt_mi) {
 457                                 /* Action element */
 458                                 ret = mi_lttng_writer_open_element(writer,
 459                                                 mi_lttng_element_command_action);
 460                                 if (ret) {
 461                                         ret = CMD_ERROR;
 462                                         goto end;
 463                                 }
 464
 465                                 /* Name of the action */
 466                                 ret = mi_lttng_writer_write_element_string(writer,
 467                                                 config_element_name, argv[0]);
 468                                 if (ret) {
 469                                         ret = CMD_ERROR;
 470                                         goto end;
 471                                 }
 472
 473                                 /* Open output element */
 474                                 ret = mi_lttng_writer_open_element(writer,
 475                                                 mi_lttng_element_command_output);
 476                                 if (ret) {
 477                                         ret = CMD_ERROR;
 478                                         goto end;
 479                                 }
 480                         }
 481
 482                         command_ret = cmd->func(argc, argv);
 483
 484                         if (lttng_opt_mi) {
 485                                 /* Close output and action element */
 486                                 ret = mi_lttng_close_multi_element(writer, 2);
 487                                 if (ret) {
 488                                         ret = CMD_ERROR;
 489                                         goto end;
 490                                 }
 491                         }
 492                         goto end;
 493                 }
 494                 i++;
 495                 cmd = &actions[i];
 496         }
 497
 498         ret = CMD_UNDEFINED;
 499
 500 end:
 501         /* Overwrite ret if an error occurred in cmd->func() */
 502         ret = command_ret ? command_ret : ret;
 503         return ret;
 504 }
 505 /*
 506  * The 'snapshot <cmd> <options>' first level command
 507  */
 508 int cmd_snapshot(int argc, const char **argv)
 509 {
 510         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 511         char *session_name = NULL;
 512         static poptContext pc;
 513
 514         pc = poptGetContext(NULL, argc, argv, snapshot_opts, 0);
 515         poptReadDefaultConfig(pc, 0);
 516
 517         /* Mi check */
 518         if (lttng_opt_mi) {
 519                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 520                 if (!writer) {
 521                         ret = -LTTNG_ERR_NOMEM;
 522                         goto end;
 523                 }
 524
 525                 /* Open command element */
 526                 ret = mi_lttng_writer_command_open(writer,
 527                                 mi_lttng_element_command_snapshot);
 528                 if (ret) {
 529                         ret = CMD_ERROR;
 530                         goto end;
 531                 }
 532
 533                 /* Open output element */
 534                 ret = mi_lttng_writer_open_element(writer,
 535                                 mi_lttng_element_command_output);
 536                 if (ret) {
 537                         ret = CMD_ERROR;
 538                         goto end;
 539                 }
 540         }
 541
 542         while ((opt = poptGetNextOpt(pc)) != -1) {
 543                 switch (opt) {
 544                 case OPT_HELP:
 545                         SHOW_HELP();
 546                         goto end;
 547                 case OPT_LIST_OPTIONS:
 548                         list_cmd_options(stdout, snapshot_opts);
 549                         goto end;
 550                 case OPT_LIST_COMMANDS:
 551                         list_commands(actions, stdout);
 552                         goto end;
 553                 case OPT_MAX_SIZE:
 554                 {
 555                         uint64_t val;
 556                         const char *opt = poptGetOptArg(pc);
 557
 558                         if (utils_parse_size_suffix((char *) opt, &val) < 0) {
 559                                 ERR("Unable to handle max-size value %s", opt);
 560                                 ret = CMD_ERROR;
 561                                 goto end;
 562                         }
 563
 564                         opt_max_size = val;
 565
 566                         break;
 567                 }
 568                 default:
 569                         ret = CMD_UNDEFINED;
 570                         goto end;
 571                 }
 572         }
 573
 574         if (!opt_session_name) {
 575                 session_name = get_session_name();
 576                 if (session_name == NULL) {
 577                         ret = CMD_ERROR;
 578                         goto end;
 579                 }
 580                 current_session_name = session_name;
 581         } else {
 582                 current_session_name = opt_session_name;
 583         }
 584
 585         command_ret = handle_command(poptGetArgs(pc));
 586         if (command_ret) {
 587                 switch (-command_ret) {
 588                 case LTTNG_ERR_SNAPSHOT_NODATA:
 589                         WARN("%s", lttng_strerror(command_ret));
 590
 591                         /*  A warning is fine since the user has no control on
 592                          *  whether or not applications (or the kernel) have
 593                          *  produced any event between the start of the tracing
 594                          *  session and the recording of the snapshot. MI wise
 595                          *  the command is not a success since nothing was
 596                          *  recorded.
 597                          */
 598                         command_ret = 0;
 599                         break;
 600                 default:
 601                         ERR("%s", lttng_strerror(command_ret));
 602                         break;
 603                 }
 604                 success = 0;
 605         }
 606
 607         if (lttng_opt_mi) {
 608                 /* Close output element */
 609                 ret = mi_lttng_writer_close_element(writer);
 610                 if (ret) {
 611                         ret = CMD_ERROR;
 612                         goto end;
 613                 }
 614
 615                 /* Success ? */
 616                 ret = mi_lttng_writer_write_element_bool(writer,
 617                                 mi_lttng_element_command_success, success);
 618                 if (ret) {
 619                         ret = CMD_ERROR;
 620                         goto end;
 621                 }
 622
 623                 /* Command element close */
 624                 ret = mi_lttng_writer_command_close(writer);
 625                 if (ret) {
 626                         ret = CMD_ERROR;
 627                         goto end;
 628                 }
 629         }
 630
 631 end:
 632         /* Mi clean-up */
 633         if (writer && mi_lttng_writer_destroy(writer)) {
 634                 /* Preserve original error code */
 635                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 636         }
 637
 638         if (!opt_session_name) {
 639                 free(session_name);
 640         }
 641
 642         /* Overwrite ret if an error occurred during handle_command */
 643         ret = command_ret ? command_ret : ret;
 644         poptFreeContext(pc);
 645         return ret;
 646 }