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 <inttypes.h>
  10 #include <popt.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <sys/stat.h>
  15 #include <sys/types.h>
  16 #include <unistd.h>
  17
  18 #include <common/utils.hpp>
  19 #include <common/mi-lttng.hpp>
  20 #include <lttng/lttng.h>
  21
  22 #include "../command.hpp"
  23
  24 static const char *opt_session_name;
  25 static const char *opt_output_name;
  26 static const char *opt_data_url;
  27 static const char *opt_ctrl_url;
  28 static const char *current_session_name;
  29 static uint64_t opt_max_size;
  30
  31 /* Stub for the cmd struct actions. */
  32 static int cmd_add_output(int argc, const char **argv);
  33 static int cmd_del_output(int argc, const char **argv);
  34 static int cmd_list_output(int argc, const char **argv);
  35 static int cmd_record(int argc, const char **argv);
  36
  37 static const char *indent4 = "    ";
  38
  39 #ifdef LTTNG_EMBED_HELP
  40 static const char help_msg[] =
  41 #include <lttng-snapshot.1.h>
  42 ;
  43 #endif
  44
  45 enum {
  46         OPT_HELP = 1,
  47         OPT_LIST_OPTIONS,
  48         OPT_MAX_SIZE,
  49         OPT_LIST_COMMANDS,
  50 };
  51
  52 static struct mi_writer *writer;
  53
  54 static struct poptOption snapshot_opts[] = {
  55         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  56         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  57         {"session",      's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  58         {"ctrl-url",     'C', POPT_ARG_STRING, &opt_ctrl_url, 0, 0, 0},
  59         {"data-url",     'D', POPT_ARG_STRING, &opt_data_url, 0, 0, 0},
  60         {"name",         'n', POPT_ARG_STRING, &opt_output_name, 0, 0, 0},
  61         {"max-size",     'm', POPT_ARG_STRING, 0, OPT_MAX_SIZE, 0, 0},
  62         {"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  63         {"list-commands",  0, POPT_ARG_NONE, NULL, OPT_LIST_COMMANDS, NULL, NULL},
  64         {0, 0, 0, 0, 0, 0, 0}
  65 };
  66
  67 static struct cmd_struct actions[] = {
  68         { "add-output", cmd_add_output },
  69         { "del-output", cmd_del_output },
  70         { "list-output", cmd_list_output },
  71         { "record", cmd_record },
  72         { NULL, NULL }  /* Array closure */
  73 };
  74
  75 /*
  76  * Count and return the number of arguments in argv.
  77  */
  78 static int count_arguments(const char **argv)
  79 {
  80         int i = 0;
  81
  82         LTTNG_ASSERT(argv);
  83
  84         while (argv[i] != NULL) {
  85                 i++;
  86         }
  87
  88         return i;
  89 }
  90
  91 /*
  92  * Create a snapshot output object from arguments using the given URL.
  93  *
  94  * Return a newly allocated object or NULL on error.
  95  */
  96 static struct lttng_snapshot_output *create_output_from_args(const char *url)
  97 {
  98         int ret = 0;
  99         struct lttng_snapshot_output *output = NULL;
 100
 101         output = lttng_snapshot_output_create();
 102         if (!output) {
 103                 goto error_create;
 104         }
 105
 106         if (url) {
 107                 ret = lttng_snapshot_output_set_ctrl_url(url, output);
 108                 if (ret < 0) {
 109                         goto error;
 110                 }
 111         } else if (opt_ctrl_url) {
 112                 ret = lttng_snapshot_output_set_ctrl_url(opt_ctrl_url, output);
 113                 if (ret < 0) {
 114                         goto error;
 115                 }
 116         }
 117
 118         if (opt_data_url) {
 119                 ret = lttng_snapshot_output_set_data_url(opt_data_url, output);
 120                 if (ret < 0) {
 121                         goto error;
 122                 }
 123         }
 124
 125         if (opt_max_size) {
 126                 ret = lttng_snapshot_output_set_size(opt_max_size, output);
 127                 if (ret < 0) {
 128                         goto error;
 129                 }
 130         }
 131
 132         if (opt_output_name) {
 133                 ret = lttng_snapshot_output_set_name(opt_output_name, output);
 134                 if (ret < 0) {
 135                         goto error;
 136                 }
 137         }
 138
 139         return output;
 140
 141 error:
 142         lttng_snapshot_output_destroy(output);
 143 error_create:
 144         return NULL;
 145 }
 146
 147 static int list_output(void)
 148 {
 149         int ret, output_seen = 0;
 150         struct lttng_snapshot_output *s_iter;
 151         struct lttng_snapshot_output_list *list;
 152
 153         ret = lttng_snapshot_list_output(current_session_name, &list);
 154         if (ret < 0) {
 155                 goto error;
 156         }
 157
 158         MSG("Snapshot output list for session %s", current_session_name);
 159
 160         if (lttng_opt_mi) {
 161                 ret = mi_lttng_snapshot_output_session_name(writer,
 162                                 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)) != NULL) {
 170                 if (lttng_snapshot_output_get_maxsize(s_iter)) {
 171                         MSG("%s[%" PRIu32 "] %s: %s (max size: %" PRIu64 " bytes)", indent4,
 172                                         lttng_snapshot_output_get_id(s_iter),
 173                                         lttng_snapshot_output_get_name(s_iter),
 174                                         lttng_snapshot_output_get_ctrl_url(s_iter),
 175                                         lttng_snapshot_output_get_maxsize(s_iter));
 176                 } else {
 177                         MSG("%s[%" PRIu32 "] %s: %s", indent4,
 178                                         lttng_snapshot_output_get_id(s_iter),
 179                                         lttng_snapshot_output_get_name(s_iter),
 180                                         lttng_snapshot_output_get_ctrl_url(s_iter));
 181                 }
 182                 output_seen = 1;
 183                 if (lttng_opt_mi) {
 184                         ret = mi_lttng_snapshot_list_output(writer, s_iter);
 185                         if (ret) {
 186                                 ret = CMD_ERROR;
 187                                 goto end;
 188                         }
 189                 }
 190         }
 191
 192         if (lttng_opt_mi) {
 193                 /* Close snapshot snapshots element */
 194                 ret = mi_lttng_writer_close_element(writer);
 195                 if (ret) {
 196                         ret = CMD_ERROR;
 197                         goto end;
 198                 }
 199
 200                 /* Close snapshot session element */
 201                 ret = mi_lttng_writer_close_element(writer);
 202                 if (ret) {
 203                         ret = CMD_ERROR;
 204                 }
 205         }
 206 end:
 207         lttng_snapshot_output_list_destroy(list);
 208
 209         if (!output_seen) {
 210                 MSG("%sNone", indent4);
 211         }
 212
 213 error:
 214         return ret;
 215 }
 216
 217 /*
 218  * Delete output by ID.
 219  */
 220 static int del_output(uint32_t id, const char *name)
 221 {
 222         int ret;
 223         struct lttng_snapshot_output *output = NULL;
 224
 225         output = lttng_snapshot_output_create();
 226         if (!output) {
 227                 ret = CMD_FATAL;
 228                 goto error;
 229         }
 230
 231         if (name) {
 232                 ret = lttng_snapshot_output_set_name(name, output);
 233         } else if (id != UINT32_MAX) {
 234                 ret = lttng_snapshot_output_set_id(id, output);
 235         } else {
 236                 ret = CMD_ERROR;
 237                 goto error;
 238         }
 239         if (ret < 0) {
 240                 ret = CMD_FATAL;
 241                 goto error;
 242         }
 243
 244         ret = lttng_snapshot_del_output(current_session_name, output);
 245         if (ret < 0) {
 246                 goto error;
 247         }
 248
 249         if (id != UINT32_MAX) {
 250                 MSG("Snapshot output id %" PRIu32 " successfully deleted for session %s",
 251                                 id, current_session_name);
 252         } else {
 253                 MSG("Snapshot output %s successfully deleted for session %s",
 254                                 name, current_session_name);
 255         }
 256
 257         if (lttng_opt_mi) {
 258                 ret = mi_lttng_snapshot_del_output(writer, id, name,
 259                                 current_session_name);
 260                 if (ret) {
 261                         ret = CMD_ERROR;
 262                 }
 263         }
 264
 265 error:
 266         lttng_snapshot_output_destroy(output);
 267         return ret;
 268 }
 269
 270 /*
 271  * Add output from the user URL.
 272  */
 273 static int add_output(const char *url)
 274 {
 275         int ret;
 276         struct lttng_snapshot_output *output = NULL;
 277         char name[NAME_MAX];
 278         const char *n_ptr;
 279
 280         if (!url && (!opt_data_url || !opt_ctrl_url)) {
 281                 ret = CMD_ERROR;
 282                 goto error;
 283         }
 284
 285         output = create_output_from_args(url);
 286         if (!output) {
 287                 ret = CMD_FATAL;
 288                 goto error;
 289         }
 290
 291         /* This call, if successful, populates the id of the output object. */
 292         ret = lttng_snapshot_add_output(current_session_name, output);
 293         if (ret < 0) {
 294                 goto error;
 295         }
 296
 297         n_ptr = lttng_snapshot_output_get_name(output);
 298         if (*n_ptr == '\0') {
 299                 int pret;
 300                 pret = snprintf(name, sizeof(name), DEFAULT_SNAPSHOT_NAME "-%" PRIu32,
 301                                 lttng_snapshot_output_get_id(output));
 302                 if (pret < 0) {
 303                         PERROR("snprintf add output name");
 304                 }
 305                 n_ptr = name;
 306         }
 307
 308         MSG("Snapshot output successfully added for session %s",
 309                         current_session_name);
 310         if (opt_max_size) {
 311                 MSG("  [%" PRIu32 "] %s: %s (max size: %" PRIu64 " bytes)",
 312                                 lttng_snapshot_output_get_id(output), n_ptr,
 313                                 lttng_snapshot_output_get_ctrl_url(output),
 314                                 lttng_snapshot_output_get_maxsize(output));
 315         } else {
 316                 MSG("  [%" PRIu32 "] %s: %s",
 317                                 lttng_snapshot_output_get_id(output), n_ptr,
 318                                 lttng_snapshot_output_get_ctrl_url(output));
 319         }
 320         if (lttng_opt_mi) {
 321                 ret = mi_lttng_snapshot_add_output(writer, current_session_name,
 322                                 n_ptr, output);
 323                 if (ret) {
 324                         ret = CMD_ERROR;
 325                 }
 326         }
 327 error:
 328         lttng_snapshot_output_destroy(output);
 329         return ret;
 330 }
 331
 332 static int cmd_add_output(int argc, const char **argv)
 333 {
 334         int ret;
 335
 336         if (argc < 2 && (!opt_data_url || !opt_ctrl_url)) {
 337                 ERR("An output destination must be specified to add a snapshot output.");
 338                 ret = CMD_ERROR;
 339                 goto end;
 340         }
 341
 342         ret = add_output(argv[1]);
 343         if (ret < 0) {
 344                 switch (-ret) {
 345                 case LTTNG_ERR_SNAPSHOT_UNSUPPORTED:
 346                         ERR("Session \"%s\" contains a channel that is incompatible with the snapshot functionality.\nMake sure all channels are configured in 'mmap' output mode.",
 347                                         current_session_name);
 348                         ret = CMD_ERROR;
 349                         break;
 350                 default:
 351                         break;
 352                 }
 353         }
 354
 355 end:
 356         return ret;
 357 }
 358
 359 static int cmd_del_output(int argc, const char **argv)
 360 {
 361         int ret;
 362         char *name;
 363         long id;
 364
 365         if (argc < 2) {
 366                 ERR("A snapshot output name or id must be provided to delete a snapshot output.");
 367                 ret = CMD_ERROR;
 368                 goto end;
 369         }
 370
 371         errno = 0;
 372         id = strtol(argv[1], &name, 10);
 373         if (id == 0 && (errno == 0 || errno == EINVAL)) {
 374                 ret = del_output(UINT32_MAX, name);
 375         } else if (errno == 0 && *name == '\0') {
 376                 ret = del_output(id, NULL);
 377         } else {
 378                 ERR("Argument %s not recognized", argv[1]);
 379                 ret = -1;
 380                 goto end;
 381         }
 382
 383 end:
 384         return ret;
 385 }
 386
 387 static int cmd_list_output(int argc __attribute__((unused)),
 388                 const char **argv __attribute__((unused)))
 389 {
 390         int ret;
 391
 392         ret = list_output();
 393
 394         return ret;
 395 }
 396
 397 /*
 398  * Do a snapshot record with the URL if one is given.
 399  */
 400 static int record(const char *url)
 401 {
 402         int ret;
 403         struct lttng_snapshot_output *output = NULL;
 404
 405         output = create_output_from_args(url);
 406         if (!output) {
 407                 ret = CMD_FATAL;
 408                 goto error;
 409         }
 410
 411         ret = lttng_snapshot_record(current_session_name, output, 0);
 412         if (ret < 0) {
 413                 if (ret == -LTTNG_ERR_MAX_SIZE_INVALID) {
 414                         ERR("Invalid snapshot size. Cannot fit at least one packet per stream.");
 415                 }
 416                 goto error;
 417         }
 418
 419         MSG("Snapshot recorded successfully for session %s", current_session_name);
 420
 421         if (url) {
 422                 MSG("Snapshot written at: %s", url);
 423         } else if (opt_ctrl_url) {
 424                 MSG("Snapshot written to ctrl: %s, data: %s", opt_ctrl_url,
 425                                 opt_data_url);
 426         }
 427
 428         if (lttng_opt_mi) {
 429                 ret = mi_lttng_snapshot_record(writer, url, opt_ctrl_url,
 430                                 opt_data_url);
 431                 if (ret) {
 432                         ret = CMD_ERROR;
 433                 }
 434         }
 435
 436 error:
 437         lttng_snapshot_output_destroy(output);
 438         return ret;
 439 }
 440
 441 static int cmd_record(int argc, const char **argv)
 442 {
 443         int ret;
 444
 445         if (argc == 2) {
 446                 ret = record(argv[1]);
 447         } else {
 448                 ret = record(NULL);
 449         }
 450
 451         return ret;
 452 }
 453
 454 static enum cmd_error_code handle_command(const char **argv)
 455 {
 456         int mi_ret, i = 0, argc;
 457         enum cmd_error_code cmd_ret;
 458         struct cmd_struct *cmd;
 459
 460         if (!argv) {
 461                 ERR("No action specified for snapshot command.");
 462                 cmd_ret = CMD_ERROR;
 463                 goto end;
 464         }
 465
 466         if ((!opt_ctrl_url && opt_data_url) ||
 467                         (opt_ctrl_url && !opt_data_url)) {
 468                 ERR("URLs must be specified for both data and control");
 469                 cmd_ret = CMD_ERROR;
 470                 goto end;
 471         }
 472
 473         argc = count_arguments(argv);
 474         /* popt should have passed NULL if no arguments are present. */
 475         LTTNG_ASSERT(argc > 0);
 476
 477         cmd = &actions[i];
 478         while (cmd->func != NULL) {
 479                 /* Find command */
 480                 if (strcmp(argv[0], cmd->name) == 0) {
 481                         int result;
 482
 483                         if (lttng_opt_mi) {
 484                                 /* Action element */
 485                                 mi_ret = mi_lttng_writer_open_element(writer,
 486                                                 mi_lttng_element_command_action);
 487                                 if (mi_ret) {
 488                                         cmd_ret = CMD_ERROR;
 489                                         goto end;
 490                                 }
 491
 492                                 /* Name of the action */
 493                                 mi_ret = mi_lttng_writer_write_element_string(writer,
 494                                                 config_element_name, argv[0]);
 495                                 if (mi_ret) {
 496                                         cmd_ret = CMD_ERROR;
 497                                         goto end;
 498                                 }
 499
 500                                 /* Open output element */
 501                                 mi_ret = mi_lttng_writer_open_element(writer,
 502                                                 mi_lttng_element_command_output);
 503                                 if (mi_ret) {
 504                                         cmd_ret = CMD_ERROR;
 505                                         goto end;
 506                                 }
 507                         }
 508
 509                         result = cmd->func(argc, argv);
 510                         if (result) {
 511                                 switch (result) {
 512                                 case CMD_ERROR:
 513                                 case CMD_UNDEFINED:
 514                                 case CMD_FATAL:
 515                                 case CMD_WARNING:
 516                                 case CMD_UNSUPPORTED:
 517                                         /*
 518                                          * Sub-commands mix lttng_error_codes
 519                                          * and cmd_error_codes. This should be
 520                                          * cleaned-up, but in the meantime this
 521                                          * hack works since the values of the
 522                                          * two enums do not intersect.
 523                                          */
 524                                         cmd_ret = (cmd_error_code) result;
 525                                         break;
 526                                 case -LTTNG_ERR_SNAPSHOT_NODATA:
 527                                         WARN("%s", lttng_strerror(result));
 528
 529                                         /*  A warning is fine since the user has no control on
 530                                          *  whether or not applications (or the kernel) have
 531                                          *  produced any event between the start of the tracing
 532                                          *  session and the recording of the snapshot. MI wise
 533                                          *  the command is not a success since nothing was
 534                                          *  recorded.
 535                                          */
 536                                         cmd_ret = CMD_SUCCESS;
 537                                         break;
 538                                 default:
 539                                         ERR("%s", lttng_strerror(result));
 540                                         cmd_ret = CMD_ERROR;
 541                                         break;
 542                                 }
 543                         } else {
 544                                 cmd_ret = CMD_SUCCESS;
 545                         }
 546
 547
 548                         if (lttng_opt_mi) {
 549                                 /* Close output and action element */
 550                                 mi_ret = mi_lttng_close_multi_element(writer, 2);
 551                                 if (mi_ret) {
 552                                         cmd_ret = CMD_ERROR;
 553                                         goto end;
 554                                 }
 555                         }
 556                         goto end;
 557                 }
 558                 i++;
 559                 cmd = &actions[i];
 560         }
 561
 562         cmd_ret = CMD_UNDEFINED;
 563
 564 end:
 565         return cmd_ret;
 566 }
 567 /*
 568  * The 'snapshot <cmd> <options>' first level command
 569  */
 570 int cmd_snapshot(int argc, const char **argv)
 571 {
 572         int opt;
 573         int mi_ret;
 574         enum cmd_error_code cmd_ret = CMD_SUCCESS;
 575         char *session_name = NULL;
 576         static poptContext pc;
 577
 578         pc = poptGetContext(NULL, argc, argv, snapshot_opts, 0);
 579         poptReadDefaultConfig(pc, 0);
 580
 581         /* Mi check */
 582         if (lttng_opt_mi) {
 583                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 584                 if (!writer) {
 585                         cmd_ret = CMD_ERROR;
 586                         goto end;
 587                 }
 588
 589                 /* Open command element */
 590                 mi_ret = mi_lttng_writer_command_open(writer,
 591                                 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,
 599                                 mi_lttng_element_command_output);
 600                 if (mi_ret) {
 601                         cmd_ret = CMD_ERROR;
 602                         goto end;
 603                 }
 604         }
 605
 606         while ((opt = poptGetNextOpt(pc)) != -1) {
 607                 switch (opt) {
 608                 case OPT_HELP:
 609                 {
 610                         int ret;
 611
 612                         /* SHOW_HELP assigns to ret. */
 613                         SHOW_HELP();
 614                         cmd_ret = (cmd_error_code) ret;
 615                         goto end;
 616                 }
 617                 case OPT_LIST_OPTIONS:
 618                         list_cmd_options(stdout, snapshot_opts);
 619                         goto end;
 620                 case OPT_LIST_COMMANDS:
 621                         list_commands(actions, stdout);
 622                         goto end;
 623                 case OPT_MAX_SIZE:
 624                 {
 625                         uint64_t val;
 626                         char *max_size_arg = poptGetOptArg(pc);
 627                         const int parse_ret = utils_parse_size_suffix(
 628                                         (char *) max_size_arg, &val);
 629
 630                         free(max_size_arg);
 631                         if (parse_ret < 0) {
 632                                 ERR("Unable to handle max-size value %s",
 633                                                 max_size_arg);
 634                                 cmd_ret = CMD_ERROR;
 635                                 goto end;
 636                         }
 637
 638                         opt_max_size = val;
 639
 640                         break;
 641                 }
 642                 default:
 643                         cmd_ret = CMD_UNDEFINED;
 644                         goto end;
 645                 }
 646         }
 647
 648         if (!opt_session_name) {
 649                 session_name = get_session_name();
 650                 if (session_name == NULL) {
 651                         cmd_ret = CMD_ERROR;
 652                         goto end;
 653                 }
 654                 current_session_name = session_name;
 655         } else {
 656                 current_session_name = opt_session_name;
 657         }
 658
 659         cmd_ret = handle_command(poptGetArgs(pc));
 660
 661         if (lttng_opt_mi) {
 662                 /* Close output element */
 663                 mi_ret = mi_lttng_writer_close_element(writer);
 664                 if (mi_ret) {
 665                         cmd_ret = CMD_ERROR;
 666                         goto end;
 667                 }
 668
 669                 /* Success ? */
 670                 mi_ret = mi_lttng_writer_write_element_bool(writer,
 671                                 mi_lttng_element_command_success,
 672                                 cmd_ret == CMD_SUCCESS);
 673                 if (mi_ret) {
 674                         cmd_ret = CMD_ERROR;
 675                         goto end;
 676                 }
 677
 678                 /* Command element close */
 679                 mi_ret = mi_lttng_writer_command_close(writer);
 680                 if (mi_ret) {
 681                         cmd_ret = CMD_ERROR;
 682                         goto end;
 683                 }
 684         }
 685
 686 end:
 687         /* Mi clean-up */
 688         if (writer && mi_lttng_writer_destroy(writer)) {
 689                 cmd_ret = CMD_ERROR;
 690         }
 691
 692         if (!opt_session_name) {
 693                 free(session_name);
 694         }
 695
 696         poptFreeContext(pc);
 697         return cmd_ret;
 698 }