src/bin/lttng/commands/snapshot.cpp

   1 /*
   2  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include "../command.hpp"
  10
  11 #include <common/mi-lttng.hpp>
  12 #include <common/utils.hpp>
  13
  14 #include <lttng/lttng.h>
  15
  16 #include <inttypes.h>
  17 #include <popt.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <sys/stat.h>
  22 #include <sys/types.h>
  23 #include <unistd.h>
  24
  25 static const char *opt_session_name;
  26 static const char *opt_output_name;
  27 static const char *opt_data_url;
  28 static const char *opt_ctrl_url;
  29 static const char *current_session_name;
  30 static uint64_t opt_max_size;
  31
  32 /* Stub for the cmd struct actions. */
  33 static int cmd_add_output(int argc, const char **argv);
  34 static int cmd_del_output(int argc, const char **argv);
  35 static int cmd_list_output(int argc, const char **argv);
  36 static int cmd_record(int argc, const char **argv);
  37
  38 static const char *indent4 = "    ";
  39
  40 #ifdef LTTNG_EMBED_HELP
  41 static const char help_msg[] =
  42 #include <lttng-snapshot.1.h>
  43         ;
  44 #endif
  45
  46 enum {
  47         OPT_HELP = 1,
  48         OPT_LIST_OPTIONS,
  49         OPT_MAX_SIZE,
  50         OPT_LIST_COMMANDS,
  51 };
  52
  53 static struct mi_writer *writer;
  54
  55 static struct poptOption snapshot_opts[] = {
  56         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  57         { "help", 'h', POPT_ARG_NONE, nullptr, OPT_HELP, nullptr, nullptr },
  58         { "session", 's', POPT_ARG_STRING, &opt_session_name, 0, nullptr, nullptr },
  59         { "ctrl-url", 'C', POPT_ARG_STRING, &opt_ctrl_url, 0, nullptr, nullptr },
  60         { "data-url", 'D', POPT_ARG_STRING, &opt_data_url, 0, nullptr, nullptr },
  61         { "name", 'n', POPT_ARG_STRING, &opt_output_name, 0, nullptr, nullptr },
  62         { "max-size", 'm', POPT_ARG_STRING, nullptr, OPT_MAX_SIZE, nullptr, nullptr },
  63         { "list-options", 0, POPT_ARG_NONE, nullptr, OPT_LIST_OPTIONS, nullptr, nullptr },
  64         { "list-commands", 0, POPT_ARG_NONE, nullptr, OPT_LIST_COMMANDS, nullptr, nullptr },
  65         { nullptr, 0, 0, nullptr, 0, nullptr, nullptr }
  66 };
  67
  68 static struct cmd_struct actions[] = {
  69         { "add-output", cmd_add_output },
  70         { "del-output", cmd_del_output },
  71         { "list-output", cmd_list_output },
  72         { "record", cmd_record },
  73         { nullptr, nullptr } /* Array closure */
  74 };
  75
  76 /*
  77  * Count and return the number of arguments in argv.
  78  */
  79 static int count_arguments(const char **argv)
  80 {
  81         int i = 0;
  82
  83         LTTNG_ASSERT(argv);
  84
  85         while (argv[i] != nullptr) {
  86                 i++;
  87         }
  88
  89         return i;
  90 }
  91
  92 /*
  93  * Create a snapshot output object from arguments using the given URL.
  94  *
  95  * Return a newly allocated object or NULL on error.
  96  */
  97 static struct lttng_snapshot_output *create_output_from_args(const char *url)
  98 {
  99         int ret = 0;
 100         struct lttng_snapshot_output *output = nullptr;
 101
 102         output = lttng_snapshot_output_create();
 103         if (!output) {
 104                 goto error_create;
 105         }
 106
 107         if (url) {
 108                 ret = lttng_snapshot_output_set_ctrl_url(url, output);
 109                 if (ret < 0) {
 110                         goto error;
 111                 }
 112         } else if (opt_ctrl_url) {
 113                 ret = lttng_snapshot_output_set_ctrl_url(opt_ctrl_url, output);
 114                 if (ret < 0) {
 115                         goto error;
 116                 }
 117         }
 118
 119         if (opt_data_url) {
 120                 ret = lttng_snapshot_output_set_data_url(opt_data_url, output);
 121                 if (ret < 0) {
 122                         goto error;
 123                 }
 124         }
 125
 126         if (opt_max_size) {
 127                 ret = lttng_snapshot_output_set_size(opt_max_size, output);
 128                 if (ret < 0) {
 129                         goto error;
 130                 }
 131         }
 132
 133         if (opt_output_name) {
 134                 ret = lttng_snapshot_output_set_name(opt_output_name, output);
 135                 if (ret < 0) {
 136                         goto error;
 137                 }
 138         }
 139
 140         return output;
 141
 142 error:
 143         lttng_snapshot_output_destroy(output);
 144 error_create:
 145         return nullptr;
 146 }
 147
 148 static int list_output()
 149 {
 150         int ret, output_seen = 0;
 151         struct lttng_snapshot_output *s_iter;
 152         struct lttng_snapshot_output_list *list;
 153
 154         ret = lttng_snapshot_list_output(current_session_name, &list);
 155         if (ret < 0) {
 156                 goto error;
 157         }
 158
 159         MSG("Snapshot output list for session %s", current_session_name);
 160
 161         if (lttng_opt_mi) {
 162                 ret = mi_lttng_snapshot_output_session_name(writer, current_session_name);
 163                 if (ret) {
 164                         ret = CMD_ERROR;
 165                         goto end;
 166                 }
 167         }
 168
 169         while ((s_iter = lttng_snapshot_output_list_get_next(list)) != nullptr) {
 170                 if (lttng_snapshot_output_get_maxsize(s_iter)) {
 171                         MSG("%s[%" PRIu32 "] %s: %s (max size: %" PRIu64 " bytes)",
 172                             indent4,
 173                             lttng_snapshot_output_get_id(s_iter),
 174                             lttng_snapshot_output_get_name(s_iter),
 175                             lttng_snapshot_output_get_ctrl_url(s_iter),
 176                             lttng_snapshot_output_get_maxsize(s_iter));
 177                 } else {
 178                         MSG("%s[%" PRIu32 "] %s: %s",
 179                             indent4,
 180                             lttng_snapshot_output_get_id(s_iter),
 181                             lttng_snapshot_output_get_name(s_iter),
 182                             lttng_snapshot_output_get_ctrl_url(s_iter));
 183                 }
 184                 output_seen = 1;
 185                 if (lttng_opt_mi) {
 186                         ret = mi_lttng_snapshot_list_output(writer, s_iter);
 187                         if (ret) {
 188                                 ret = CMD_ERROR;
 189                                 goto end;
 190                         }
 191                 }
 192         }
 193
 194         if (lttng_opt_mi) {
 195                 /* Close snapshot snapshots element */
 196                 ret = mi_lttng_writer_close_element(writer);
 197                 if (ret) {
 198                         ret = CMD_ERROR;
 199                         goto end;
 200                 }
 201
 202                 /* Close snapshot session element */
 203                 ret = mi_lttng_writer_close_element(writer);
 204                 if (ret) {
 205                         ret = CMD_ERROR;
 206                 }
 207         }
 208 end:
 209         lttng_snapshot_output_list_destroy(list);
 210
 211         if (!output_seen) {
 212                 MSG("%sNone", indent4);
 213         }
 214
 215 error:
 216         return ret;
 217 }
 218
 219 /*
 220  * Delete output by ID.
 221  */
 222 static int del_output(uint32_t id, const char *name)
 223 {
 224         int ret;
 225         struct lttng_snapshot_output *output = nullptr;
 226
 227         output = lttng_snapshot_output_create();
 228         if (!output) {
 229                 ret = CMD_FATAL;
 230                 goto error;
 231         }
 232
 233         if (name) {
 234                 ret = lttng_snapshot_output_set_name(name, output);
 235         } else if (id != UINT32_MAX) {
 236                 ret = lttng_snapshot_output_set_id(id, output);
 237         } else {
 238                 ret = CMD_ERROR;
 239                 goto error;
 240         }
 241         if (ret < 0) {
 242                 ret = CMD_FATAL;
 243                 goto error;
 244         }
 245
 246         ret = lttng_snapshot_del_output(current_session_name, output);
 247         if (ret < 0) {
 248                 goto error;
 249         }
 250
 251         if (id != UINT32_MAX) {
 252                 MSG("Snapshot output id %" PRIu32 " successfully deleted for session %s",
 253                     id,
 254                     current_session_name);
 255         } else {
 256                 MSG("Snapshot output %s successfully deleted for session %s",
 257                     name,
 258                     current_session_name);
 259         }
 260
 261         if (lttng_opt_mi) {
 262                 ret = mi_lttng_snapshot_del_output(writer, id, name, current_session_name);
 263                 if (ret) {
 264                         ret = CMD_ERROR;
 265                 }
 266         }
 267
 268 error:
 269         lttng_snapshot_output_destroy(output);
 270         return ret;
 271 }
 272
 273 /*
 274  * Add output from the user URL.
 275  */
 276 static int add_output(const char *url)
 277 {
 278         int ret;
 279         struct lttng_snapshot_output *output = nullptr;
 280         char name[NAME_MAX];
 281         const char *n_ptr;
 282
 283         if (!url && (!opt_data_url || !opt_ctrl_url)) {
 284                 ret = CMD_ERROR;
 285                 goto error;
 286         }
 287
 288         output = create_output_from_args(url);
 289         if (!output) {
 290                 ret = CMD_FATAL;
 291                 goto error;
 292         }
 293
 294         /* This call, if successful, populates the id of the output object. */
 295         ret = lttng_snapshot_add_output(current_session_name, output);
 296         if (ret < 0) {
 297                 goto error;
 298         }
 299
 300         n_ptr = lttng_snapshot_output_get_name(output);
 301         if (*n_ptr == '\0') {
 302                 int pret;
 303                 pret = snprintf(name,
 304                                 sizeof(name),
 305                                 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", current_session_name);
 314         if (opt_max_size) {
 315                 MSG("  [%" PRIu32 "] %s: %s (max size: %" PRIu64 " bytes)",
 316                     lttng_snapshot_output_get_id(output),
 317                     n_ptr,
 318                     lttng_snapshot_output_get_ctrl_url(output),
 319                     lttng_snapshot_output_get_maxsize(output));
 320         } else {
 321                 MSG("  [%" PRIu32 "] %s: %s",
 322                     lttng_snapshot_output_get_id(output),
 323                     n_ptr,
 324                     lttng_snapshot_output_get_ctrl_url(output));
 325         }
 326         if (lttng_opt_mi) {
 327                 ret = mi_lttng_snapshot_add_output(writer, current_session_name, n_ptr, output);
 328                 if (ret) {
 329                         ret = CMD_ERROR;
 330                 }
 331         }
 332 error:
 333         lttng_snapshot_output_destroy(output);
 334         return ret;
 335 }
 336
 337 static int cmd_add_output(int argc, const char **argv)
 338 {
 339         int ret;
 340
 341         if (argc < 2 && (!opt_data_url || !opt_ctrl_url)) {
 342                 ERR("An output destination must be specified to add a snapshot output.");
 343                 ret = CMD_ERROR;
 344                 goto end;
 345         }
 346
 347         ret = add_output(argv[1]);
 348         if (ret < 0) {
 349                 switch (-ret) {
 350                 case LTTNG_ERR_SNAPSHOT_UNSUPPORTED:
 351                         ERR("Session \"%s\" contains a channel that is incompatible with the snapshot functionality.\nMake sure all channels are configured in 'mmap' output mode.",
 352                             current_session_name);
 353                         ret = CMD_ERROR;
 354                         break;
 355                 default:
 356                         break;
 357                 }
 358         }
 359
 360 end:
 361         return ret;
 362 }
 363
 364 static int cmd_del_output(int argc, const char **argv)
 365 {
 366         int ret;
 367         char *name;
 368         long id;
 369
 370         if (argc < 2) {
 371                 ERR("A snapshot output name or id must be provided to delete a snapshot output.");
 372                 ret = CMD_ERROR;
 373                 goto end;
 374         }
 375
 376         errno = 0;
 377         id = strtol(argv[1], &name, 10);
 378         if (id == 0 && (errno == 0 || errno == EINVAL)) {
 379                 ret = del_output(UINT32_MAX, name);
 380         } else if (errno == 0 && *name == '\0') {
 381                 ret = del_output(id, nullptr);
 382         } else {
 383                 ERR("Argument %s not recognized", argv[1]);
 384                 ret = -1;
 385                 goto end;
 386         }
 387
 388 end:
 389         return ret;
 390 }
 391
 392 static int cmd_list_output(int argc __attribute__((unused)),
 393                            const char **argv __attribute__((unused)))
 394 {
 395         int ret;
 396
 397         ret = list_output();
 398
 399         return ret;
 400 }
 401
 402 /*
 403  * Do a snapshot record with the URL if one is given.
 404  */
 405 static int record(const char *url)
 406 {
 407         int ret;
 408         struct lttng_snapshot_output *output = nullptr;
 409
 410         output = create_output_from_args(url);
 411         if (!output) {
 412                 ret = CMD_FATAL;
 413                 goto error;
 414         }
 415
 416         ret = lttng_snapshot_record(current_session_name, output, 0);
 417         if (ret < 0) {
 418                 if (ret == -LTTNG_ERR_MAX_SIZE_INVALID) {
 419                         ERR("Invalid snapshot size. Cannot fit at least one packet per stream.");
 420                 }
 421                 goto error;
 422         }
 423
 424         MSG("Snapshot recorded successfully for session %s", current_session_name);
 425
 426         if (url) {
 427                 MSG("Snapshot written at: %s", url);
 428         } else if (opt_ctrl_url) {
 429                 MSG("Snapshot written to ctrl: %s, data: %s", opt_ctrl_url, opt_data_url);
 430         }
 431
 432         if (lttng_opt_mi) {
 433                 ret = mi_lttng_snapshot_record(writer, url, opt_ctrl_url, opt_data_url);
 434                 if (ret) {
 435                         ret = CMD_ERROR;
 436                 }
 437         }
 438
 439 error:
 440         lttng_snapshot_output_destroy(output);
 441         return ret;
 442 }
 443
 444 static int cmd_record(int argc, const char **argv)
 445 {
 446         int ret;
 447
 448         if (argc == 2) {
 449                 ret = record(argv[1]);
 450         } else {
 451                 ret = record(nullptr);
 452         }
 453
 454         return ret;
 455 }
 456
 457 static enum cmd_error_code handle_command(const char **argv)
 458 {
 459         int mi_ret, i = 0, argc;
 460         enum cmd_error_code cmd_ret;
 461         struct cmd_struct *cmd;
 462
 463         if (!argv) {
 464                 ERR("No action specified for snapshot command.");
 465                 cmd_ret = CMD_ERROR;
 466                 goto end;
 467         }
 468
 469         if ((!opt_ctrl_url && opt_data_url) || (opt_ctrl_url && !opt_data_url)) {
 470                 ERR("URLs must be specified for both data and control");
 471                 cmd_ret = CMD_ERROR;
 472                 goto end;
 473         }
 474
 475         argc = count_arguments(argv);
 476         /* popt should have passed NULL if no arguments are present. */
 477         LTTNG_ASSERT(argc > 0);
 478
 479         cmd = &actions[i];
 480         while (cmd->func != nullptr) {
 481                 /* Find command */
 482                 if (strcmp(argv[0], cmd->name) == 0) {
 483                         int result;
 484
 485                         if (lttng_opt_mi) {
 486                                 /* Action element */
 487                                 mi_ret = mi_lttng_writer_open_element(
 488                                         writer, mi_lttng_element_command_action);
 489                                 if (mi_ret) {
 490                                         cmd_ret = CMD_ERROR;
 491                                         goto end;
 492                                 }
 493
 494                                 /* Name of the action */
 495                                 mi_ret = mi_lttng_writer_write_element_string(
 496                                         writer, config_element_name, argv[0]);
 497                                 if (mi_ret) {
 498                                         cmd_ret = CMD_ERROR;
 499                                         goto end;
 500                                 }
 501
 502                                 /* Open output element */
 503                                 mi_ret = mi_lttng_writer_open_element(
 504                                         writer, mi_lttng_element_command_output);
 505                                 if (mi_ret) {
 506                                         cmd_ret = CMD_ERROR;
 507                                         goto end;
 508                                 }
 509                         }
 510
 511                         result = cmd->func(argc, argv);
 512                         if (result) {
 513                                 switch (result) {
 514                                 case CMD_ERROR:
 515                                 case CMD_UNDEFINED:
 516                                 case CMD_FATAL:
 517                                 case CMD_WARNING:
 518                                 case CMD_UNSUPPORTED:
 519                                         /*
 520                                          * Sub-commands mix lttng_error_codes
 521                                          * and cmd_error_codes. This should be
 522                                          * cleaned-up, but in the meantime this
 523                                          * hack works since the values of the
 524                                          * two enums do not intersect.
 525                                          */
 526                                         cmd_ret = (cmd_error_code) result;
 527                                         break;
 528                                 case -LTTNG_ERR_SNAPSHOT_NODATA:
 529                                         WARN("%s", lttng_strerror(result));
 530
 531                                         /*  A warning is fine since the user has no control on
 532                                          *  whether or not applications (or the kernel) have
 533                                          *  produced any event between the start of the tracing
 534                                          *  session and the recording of the snapshot. MI wise
 535                                          *  the command is not a success since nothing was
 536                                          *  recorded.
 537                                          */
 538                                         cmd_ret = CMD_SUCCESS;
 539                                         break;
 540                                 default:
 541                                         ERR("%s", lttng_strerror(result));
 542                                         cmd_ret = CMD_ERROR;
 543                                         break;
 544                                 }
 545                         } else {
 546                                 cmd_ret = CMD_SUCCESS;
 547                         }
 548
 549                         if (lttng_opt_mi) {
 550                                 /* Close output and action element */
 551                                 mi_ret = mi_lttng_close_multi_element(writer, 2);
 552                                 if (mi_ret) {
 553                                         cmd_ret = CMD_ERROR;
 554                                         goto end;
 555                                 }
 556                         }
 557                         goto end;
 558                 }
 559                 i++;
 560                 cmd = &actions[i];
 561         }
 562
 563         cmd_ret = CMD_UNDEFINED;
 564
 565 end:
 566         return cmd_ret;
 567 }
 568 /*
 569  * The 'snapshot <cmd> <options>' first level command
 570  */
 571 int cmd_snapshot(int argc, const char **argv)
 572 {
 573         int opt;
 574         int mi_ret;
 575         enum cmd_error_code cmd_ret = CMD_SUCCESS;
 576         char *session_name = nullptr;
 577         static poptContext pc;
 578
 579         pc = poptGetContext(nullptr, argc, argv, snapshot_opts, 0);
 580         poptReadDefaultConfig(pc, 0);
 581
 582         /* Mi check */
 583         if (lttng_opt_mi) {
 584                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 585                 if (!writer) {
 586                         cmd_ret = CMD_ERROR;
 587                         goto end;
 588                 }
 589
 590                 /* Open command element */
 591                 mi_ret = mi_lttng_writer_command_open(writer, mi_lttng_element_command_snapshot);
 592                 if (mi_ret) {
 593                         cmd_ret = CMD_ERROR;
 594                         goto end;
 595                 }
 596
 597                 /* Open output element */
 598                 mi_ret = mi_lttng_writer_open_element(writer, mi_lttng_element_command_output);
 599                 if (mi_ret) {
 600                         cmd_ret = CMD_ERROR;
 601                         goto end;
 602                 }
 603         }
 604
 605         while ((opt = poptGetNextOpt(pc)) != -1) {
 606                 switch (opt) {
 607                 case OPT_HELP:
 608                 {
 609                         int ret;
 610
 611                         /* SHOW_HELP assigns to ret. */
 612                         SHOW_HELP();
 613                         cmd_ret = (cmd_error_code) ret;
 614                         goto end;
 615                 }
 616                 case OPT_LIST_OPTIONS:
 617                         list_cmd_options(stdout, snapshot_opts);
 618                         goto end;
 619                 case OPT_LIST_COMMANDS:
 620                         list_commands(actions, stdout);
 621                         goto end;
 622                 case OPT_MAX_SIZE:
 623                 {
 624                         uint64_t val;
 625                         char *max_size_arg = poptGetOptArg(pc);
 626                         const int parse_ret = utils_parse_size_suffix((char *) max_size_arg, &val);
 627
 628                         if (parse_ret < 0) {
 629                                 ERR("Unable to handle max-size value %s", max_size_arg);
 630                                 cmd_ret = CMD_ERROR;
 631                                 free(max_size_arg);
 632                                 goto end;
 633                         }
 634
 635                         opt_max_size = val;
 636                         free(max_size_arg);
 637                         break;
 638                 }
 639                 default:
 640                         cmd_ret = CMD_UNDEFINED;
 641                         goto end;
 642                 }
 643         }
 644
 645         if (!opt_session_name) {
 646                 session_name = get_session_name();
 647                 if (session_name == nullptr) {
 648                         cmd_ret = CMD_ERROR;
 649                         goto end;
 650                 }
 651                 current_session_name = session_name;
 652         } else {
 653                 current_session_name = opt_session_name;
 654         }
 655
 656         cmd_ret = handle_command(poptGetArgs(pc));
 657
 658         if (lttng_opt_mi) {
 659                 /* Close output element */
 660                 mi_ret = mi_lttng_writer_close_element(writer);
 661                 if (mi_ret) {
 662                         cmd_ret = CMD_ERROR;
 663                         goto end;
 664                 }
 665
 666                 /* Success ? */
 667                 mi_ret = mi_lttng_writer_write_element_bool(
 668                         writer, mi_lttng_element_command_success, cmd_ret == CMD_SUCCESS);
 669                 if (mi_ret) {
 670                         cmd_ret = CMD_ERROR;
 671                         goto end;
 672                 }
 673
 674                 /* Command element close */
 675                 mi_ret = mi_lttng_writer_command_close(writer);
 676                 if (mi_ret) {
 677                         cmd_ret = CMD_ERROR;
 678                         goto end;
 679                 }
 680         }
 681
 682 end:
 683         /* Mi clean-up */
 684         if (writer && mi_lttng_writer_destroy(writer)) {
 685                 cmd_ret = CMD_ERROR;
 686         }
 687
 688         if (!opt_session_name) {
 689                 free(session_name);
 690         }
 691
 692         poptFreeContext(pc);
 693         return cmd_ret;
 694 }