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                 if (lttng_snapshot_output_get_maxsize(s_iter)) {
 183                         MSG("%s[%" PRIu32 "] %s: %s (max size: %" PRIu64 " bytes)", indent4,
 184                                         lttng_snapshot_output_get_id(s_iter),
 185                                         lttng_snapshot_output_get_name(s_iter),
 186                                         lttng_snapshot_output_get_ctrl_url(s_iter),
 187                                         lttng_snapshot_output_get_maxsize(s_iter));
 188                 } else {
 189                         MSG("%s[%" PRIu32 "] %s: %s", indent4,
 190                                         lttng_snapshot_output_get_id(s_iter),
 191                                         lttng_snapshot_output_get_name(s_iter),
 192                                         lttng_snapshot_output_get_ctrl_url(s_iter));
 193                 }
 194                 output_seen = 1;
 195                 if (lttng_opt_mi) {
 196                         ret = mi_lttng_snapshot_list_output(writer, s_iter);
 197                         if (ret) {
 198                                 ret = CMD_ERROR;
 199                                 goto end;
 200                         }
 201                 }
 202         }
 203
 204         if (lttng_opt_mi) {
 205                 /* Close snapshot snapshots element */
 206                 ret = mi_lttng_writer_close_element(writer);
 207                 if (ret) {
 208                         ret = CMD_ERROR;
 209                         goto end;
 210                 }
 211
 212                 /* Close snapshot session element */
 213                 ret = mi_lttng_writer_close_element(writer);
 214                 if (ret) {
 215                         ret = CMD_ERROR;
 216                 }
 217         }
 218 end:
 219         lttng_snapshot_output_list_destroy(list);
 220
 221         if (!output_seen) {
 222                 MSG("%sNone", indent4);
 223         }
 224
 225 error:
 226         return ret;
 227 }
 228
 229 /*
 230  * Delete output by ID.
 231  */
 232 static int del_output(uint32_t id, const char *name)
 233 {
 234         int ret;
 235         struct lttng_snapshot_output *output = NULL;
 236
 237         output = lttng_snapshot_output_create();
 238         if (!output) {
 239                 ret = CMD_FATAL;
 240                 goto error;
 241         }
 242
 243         if (name) {
 244                 ret = lttng_snapshot_output_set_name(name, output);
 245         } else if (id != UINT32_MAX) {
 246                 ret = lttng_snapshot_output_set_id(id, output);
 247         } else {
 248                 ret = CMD_ERROR;
 249                 goto error;
 250         }
 251         if (ret < 0) {
 252                 ret = CMD_FATAL;
 253                 goto error;
 254         }
 255
 256         ret = lttng_snapshot_del_output(current_session_name, output);
 257         if (ret < 0) {
 258                 goto error;
 259         }
 260
 261         if (id != UINT32_MAX) {
 262                 MSG("Snapshot output id %" PRIu32 " successfully deleted for session %s",
 263                                 id, current_session_name);
 264         } else {
 265                 MSG("Snapshot output %s successfully deleted for session %s",
 266                                 name, current_session_name);
 267         }
 268
 269         if (lttng_opt_mi) {
 270                 ret = mi_lttng_snapshot_del_output(writer, id, name,
 271                                 current_session_name);
 272                 if (ret) {
 273                         ret = CMD_ERROR;
 274                 }
 275         }
 276
 277 error:
 278         lttng_snapshot_output_destroy(output);
 279         return ret;
 280 }
 281
 282 /*
 283  * Add output from the user URL.
 284  */
 285 static int add_output(const char *url)
 286 {
 287         int ret;
 288         struct lttng_snapshot_output *output = NULL;
 289         char name[NAME_MAX];
 290         const char *n_ptr;
 291
 292         if (!url && (!opt_data_url || !opt_ctrl_url)) {
 293                 ret = CMD_ERROR;
 294                 goto error;
 295         }
 296
 297         output = create_output_from_args(url);
 298         if (!output) {
 299                 ret = CMD_FATAL;
 300                 goto error;
 301         }
 302
 303         /* This call, if successful, populates the id of the output object. */
 304         ret = lttng_snapshot_add_output(current_session_name, output);
 305         if (ret < 0) {
 306                 goto error;
 307         }
 308
 309         n_ptr = lttng_snapshot_output_get_name(output);
 310         if (*n_ptr == '\0') {
 311                 int pret;
 312                 pret = snprintf(name, sizeof(name), DEFAULT_SNAPSHOT_NAME "-%" PRIu32,
 313                                 lttng_snapshot_output_get_id(output));
 314                 if (pret < 0) {
 315                         PERROR("snprintf add output name");
 316                 }
 317                 n_ptr = name;
 318         }
 319
 320         MSG("Snapshot output successfully added for session %s",
 321                         current_session_name);
 322         if (opt_max_size) {
 323                 MSG("  [%" PRIu32 "] %s: %s (max size: %" PRIu64 " bytes)",
 324                                 lttng_snapshot_output_get_id(output), n_ptr,
 325                                 lttng_snapshot_output_get_ctrl_url(output),
 326                                 lttng_snapshot_output_get_maxsize(output));
 327         } else {
 328                 MSG("  [%" PRIu32 "] %s: %s",
 329                                 lttng_snapshot_output_get_id(output), n_ptr,
 330                                 lttng_snapshot_output_get_ctrl_url(output));
 331         }
 332         if (lttng_opt_mi) {
 333                 ret = mi_lttng_snapshot_add_output(writer, current_session_name,
 334                                 n_ptr, output);
 335                 if (ret) {
 336                         ret = CMD_ERROR;
 337                 }
 338         }
 339 error:
 340         lttng_snapshot_output_destroy(output);
 341         return ret;
 342 }
 343
 344 static int cmd_add_output(int argc, const char **argv)
 345 {
 346         int ret;
 347
 348         if (argc < 2 && (!opt_data_url || !opt_ctrl_url)) {
 349                 ERR("An output destination must be specified to add a snapshot output.");
 350                 ret = CMD_ERROR;
 351                 goto end;
 352         }
 353
 354         ret = add_output(argv[1]);
 355         if (ret < 0) {
 356                 switch (-ret) {
 357                 case LTTNG_ERR_SNAPSHOT_UNSUPPORTED:
 358                         ERR("Session \"%s\" contains a channel that is incompatible with the snapshot functionality.\nMake sure all channels are configured in 'mmap' output mode.",
 359                                         current_session_name);
 360                         ret = CMD_ERROR;
 361                         break;
 362                 default:
 363                         break;
 364                 }
 365         }
 366
 367 end:
 368         return ret;
 369 }
 370
 371 static int cmd_del_output(int argc, const char **argv)
 372 {
 373         int ret;
 374         char *name;
 375         long id;
 376
 377         if (argc < 2) {
 378                 ret = CMD_ERROR;
 379                 goto end;
 380         }
 381
 382         errno = 0;
 383         id = strtol(argv[1], &name, 10);
 384         if (id == 0 && (errno == 0 || errno == EINVAL)) {
 385                 ret = del_output(UINT32_MAX, name);
 386         } else if (errno == 0 && *name == '\0') {
 387                 ret = del_output(id, NULL);
 388         } else {
 389                 ERR("Argument %s not recognized", argv[1]);
 390                 ret = -1;
 391                 goto end;
 392         }
 393
 394 end:
 395         return ret;
 396 }
 397
 398 static int cmd_list_output(int argc, const char **argv)
 399 {
 400         int ret;
 401
 402         ret = list_output();
 403
 404         return ret;
 405 }
 406
 407 /*
 408  * Do a snapshot record with the URL if one is given.
 409  */
 410 static int record(const char *url)
 411 {
 412         int ret;
 413         struct lttng_snapshot_output *output = NULL;
 414
 415         output = create_output_from_args(url);
 416         if (!output) {
 417                 ret = CMD_FATAL;
 418                 goto error;
 419         }
 420
 421         ret = lttng_snapshot_record(current_session_name, output, 0);
 422         if (ret < 0) {
 423                 if (ret == -LTTNG_ERR_MAX_SIZE_INVALID) {
 424                         ERR("Invalid snapshot size. Cannot fit at least one packet per stream.");
 425                 }
 426                 goto error;
 427         }
 428
 429         MSG("Snapshot recorded successfully for session %s", current_session_name);
 430
 431         if (url) {
 432                 MSG("Snapshot written at: %s", url);
 433         } else if (opt_ctrl_url) {
 434                 MSG("Snapshot written to ctrl: %s, data: %s", opt_ctrl_url,
 435                                 opt_data_url);
 436         }
 437
 438         if (lttng_opt_mi) {
 439                 ret = mi_lttng_snapshot_record(writer, current_session_name, url,
 440                                 opt_ctrl_url, opt_data_url);
 441                 if (ret) {
 442                         ret = CMD_ERROR;
 443                 }
 444         }
 445
 446 error:
 447         lttng_snapshot_output_destroy(output);
 448         return ret;
 449 }
 450
 451 static int cmd_record(int argc, const char **argv)
 452 {
 453         int ret;
 454
 455         if (argc == 2) {
 456                 ret = record(argv[1]);
 457         } else {
 458                 ret = record(NULL);
 459         }
 460
 461         return ret;
 462 }
 463
 464 static enum cmd_error_code handle_command(const char **argv)
 465 {
 466         int mi_ret, i = 0, argc;
 467         enum cmd_error_code cmd_ret;
 468         struct cmd_struct *cmd;
 469
 470         if (!argv) {
 471                 ERR("No action specified for snapshot command.");
 472                 cmd_ret = CMD_ERROR;
 473                 goto end;
 474         }
 475
 476         if ((!opt_ctrl_url && opt_data_url) ||
 477                         (opt_ctrl_url && !opt_data_url)) {
 478                 ERR("URLs must be specified for both data and control");
 479                 cmd_ret = CMD_ERROR;
 480                 goto end;
 481         }
 482
 483         argc = count_arguments(argv);
 484         /* popt should have passed NULL if no arguments are present. */
 485         assert(argc > 0);
 486
 487         cmd = &actions[i];
 488         while (cmd->func != NULL) {
 489                 /* Find command */
 490                 if (strcmp(argv[0], cmd->name) == 0) {
 491                         int result;
 492
 493                         if (lttng_opt_mi) {
 494                                 /* Action element */
 495                                 mi_ret = mi_lttng_writer_open_element(writer,
 496                                                 mi_lttng_element_command_action);
 497                                 if (mi_ret) {
 498                                         cmd_ret = CMD_ERROR;
 499                                         goto end;
 500                                 }
 501
 502                                 /* Name of the action */
 503                                 mi_ret = mi_lttng_writer_write_element_string(writer,
 504                                                 config_element_name, argv[0]);
 505                                 if (mi_ret) {
 506                                         cmd_ret = CMD_ERROR;
 507                                         goto end;
 508                                 }
 509
 510                                 /* Open output element */
 511                                 mi_ret = mi_lttng_writer_open_element(writer,
 512                                                 mi_lttng_element_command_output);
 513                                 if (mi_ret) {
 514                                         cmd_ret = CMD_ERROR;
 515                                         goto end;
 516                                 }
 517                         }
 518
 519                         result = cmd->func(argc, argv);
 520                         if (result) {
 521                                 switch (result) {
 522                                 case CMD_ERROR:
 523                                 case CMD_UNDEFINED:
 524                                 case CMD_FATAL:
 525                                 case CMD_WARNING:
 526                                 case CMD_UNSUPPORTED:
 527                                         /*
 528                                          * Sub-commands mix lttng_error_codes
 529                                          * and cmd_error_codes. This should be
 530                                          * cleaned-up, but in the meantime this
 531                                          * hack works since the values of the
 532                                          * two enums do not intersect.
 533                                          */
 534                                         cmd_ret = result;
 535                                         break;
 536                                 case -LTTNG_ERR_SNAPSHOT_NODATA:
 537                                         WARN("%s", lttng_strerror(result));
 538
 539                                         /*  A warning is fine since the user has no control on
 540                                          *  whether or not applications (or the kernel) have
 541                                          *  produced any event between the start of the tracing
 542                                          *  session and the recording of the snapshot. MI wise
 543                                          *  the command is not a success since nothing was
 544                                          *  recorded.
 545                                          */
 546                                         cmd_ret = CMD_SUCCESS;
 547                                         break;
 548                                 default:
 549                                         ERR("%s", lttng_strerror(result));
 550                                         cmd_ret = CMD_ERROR;
 551                                         break;
 552                                 }
 553                         } else {
 554                                 cmd_ret = CMD_SUCCESS;
 555                         }
 556
 557
 558                         if (lttng_opt_mi) {
 559                                 /* Close output and action element */
 560                                 mi_ret = mi_lttng_close_multi_element(writer, 2);
 561                                 if (mi_ret) {
 562                                         cmd_ret = CMD_ERROR;
 563                                         goto end;
 564                                 }
 565                         }
 566                         goto end;
 567                 }
 568                 i++;
 569                 cmd = &actions[i];
 570         }
 571
 572         cmd_ret = CMD_UNDEFINED;
 573
 574 end:
 575         return cmd_ret;
 576 }
 577 /*
 578  * The 'snapshot <cmd> <options>' first level command
 579  */
 580 int cmd_snapshot(int argc, const char **argv)
 581 {
 582         int opt;
 583         int mi_ret;
 584         enum cmd_error_code cmd_ret = CMD_SUCCESS;
 585         char *session_name = NULL;
 586         static poptContext pc;
 587
 588         pc = poptGetContext(NULL, argc, argv, snapshot_opts, 0);
 589         poptReadDefaultConfig(pc, 0);
 590
 591         /* Mi check */
 592         if (lttng_opt_mi) {
 593                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 594                 if (!writer) {
 595                         cmd_ret = CMD_ERROR;
 596                         goto end;
 597                 }
 598
 599                 /* Open command element */
 600                 mi_ret = mi_lttng_writer_command_open(writer,
 601                                 mi_lttng_element_command_snapshot);
 602                 if (mi_ret) {
 603                         cmd_ret = CMD_ERROR;
 604                         goto end;
 605                 }
 606
 607                 /* Open output element */
 608                 mi_ret = mi_lttng_writer_open_element(writer,
 609                                 mi_lttng_element_command_output);
 610                 if (mi_ret) {
 611                         cmd_ret = CMD_ERROR;
 612                         goto end;
 613                 }
 614         }
 615
 616         while ((opt = poptGetNextOpt(pc)) != -1) {
 617                 switch (opt) {
 618                 case OPT_HELP:
 619                 {
 620                         int ret;
 621
 622                         /* SHOW_HELP assigns to ret. */
 623                         SHOW_HELP();
 624                         cmd_ret = ret;
 625                         goto end;
 626                 }
 627                 case OPT_LIST_OPTIONS:
 628                         list_cmd_options(stdout, snapshot_opts);
 629                         goto end;
 630                 case OPT_LIST_COMMANDS:
 631                         list_commands(actions, stdout);
 632                         goto end;
 633                 case OPT_MAX_SIZE:
 634                 {
 635                         uint64_t val;
 636                         const char *opt = poptGetOptArg(pc);
 637
 638                         if (utils_parse_size_suffix((char *) opt, &val) < 0) {
 639                                 ERR("Unable to handle max-size value %s", opt);
 640                                 cmd_ret = CMD_ERROR;
 641                                 goto end;
 642                         }
 643
 644                         opt_max_size = val;
 645
 646                         break;
 647                 }
 648                 default:
 649                         cmd_ret = CMD_UNDEFINED;
 650                         goto end;
 651                 }
 652         }
 653
 654         if (!opt_session_name) {
 655                 session_name = get_session_name();
 656                 if (session_name == NULL) {
 657                         cmd_ret = CMD_ERROR;
 658                         goto end;
 659                 }
 660                 current_session_name = session_name;
 661         } else {
 662                 current_session_name = opt_session_name;
 663         }
 664
 665         cmd_ret = handle_command(poptGetArgs(pc));
 666
 667         if (lttng_opt_mi) {
 668                 /* Close output element */
 669                 mi_ret = mi_lttng_writer_close_element(writer);
 670                 if (mi_ret) {
 671                         cmd_ret = CMD_ERROR;
 672                         goto end;
 673                 }
 674
 675                 /* Success ? */
 676                 mi_ret = mi_lttng_writer_write_element_bool(writer,
 677                                 mi_lttng_element_command_success,
 678                                 cmd_ret == CMD_SUCCESS);
 679                 if (mi_ret) {
 680                         cmd_ret = CMD_ERROR;
 681                         goto end;
 682                 }
 683
 684                 /* Command element close */
 685                 mi_ret = mi_lttng_writer_command_close(writer);
 686                 if (mi_ret) {
 687                         cmd_ret = CMD_ERROR;
 688                         goto end;
 689                 }
 690         }
 691
 692 end:
 693         /* Mi clean-up */
 694         if (writer && mi_lttng_writer_destroy(writer)) {
 695                 cmd_ret = CMD_ERROR;
 696         }
 697
 698         if (!opt_session_name) {
 699                 free(session_name);
 700         }
 701
 702         poptFreeContext(pc);
 703         return cmd_ret;
 704 }