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                 ret = CMD_ERROR;
 350                 goto end;
 351         }
 352
 353         ret = add_output(argv[1]);
 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                 ret = CMD_ERROR;
 367                 goto end;
 368         }
 369
 370         errno = 0;
 371         id = strtol(argv[1], &name, 10);
 372         if (id == 0 && (errno == 0 || errno == EINVAL)) {
 373                 ret = del_output(UINT32_MAX, name);
 374         } else if (errno == 0 && *name == '\0') {
 375                 ret = del_output(id, NULL);
 376         } else {
 377                 ERR("Argument %s not recognized", argv[1]);
 378                 ret = -1;
 379                 goto end;
 380         }
 381
 382 end:
 383         return ret;
 384 }
 385
 386 static int cmd_list_output(int argc, const char **argv)
 387 {
 388         int ret;
 389
 390         ret = list_output();
 391
 392         return ret;
 393 }
 394
 395 /*
 396  * Do a snapshot record with the URL if one is given.
 397  */
 398 static int record(const char *url)
 399 {
 400         int ret;
 401         struct lttng_snapshot_output *output = NULL;
 402
 403         output = create_output_from_args(url);
 404         if (!output) {
 405                 ret = CMD_FATAL;
 406                 goto error;
 407         }
 408
 409         ret = lttng_snapshot_record(current_session_name, output, 0);
 410         if (ret < 0) {
 411                 if (ret == -LTTNG_ERR_MAX_SIZE_INVALID) {
 412                         ERR("Invalid snapshot size. Cannot fit at least one packet per stream.");
 413                 }
 414                 goto error;
 415         }
 416
 417         MSG("Snapshot recorded successfully for session %s", current_session_name);
 418
 419         if (url) {
 420                 MSG("Snapshot written at: %s", url);
 421         } else if (opt_ctrl_url) {
 422                 MSG("Snapshot written to ctrl: %s, data: %s", opt_ctrl_url,
 423                                 opt_data_url);
 424         }
 425
 426         if (lttng_opt_mi) {
 427                 ret = mi_lttng_snapshot_record(writer, current_session_name, url,
 428                                 opt_ctrl_url, opt_data_url);
 429                 if (ret) {
 430                         ret = CMD_ERROR;
 431                 }
 432         }
 433
 434 error:
 435         lttng_snapshot_output_destroy(output);
 436         return ret;
 437 }
 438
 439 static int cmd_record(int argc, const char **argv)
 440 {
 441         int ret;
 442
 443         if (argc == 2) {
 444                 ret = record(argv[1]);
 445         } else {
 446                 ret = record(NULL);
 447         }
 448
 449         return ret;
 450 }
 451
 452 static enum cmd_error_code handle_command(const char **argv)
 453 {
 454         int mi_ret, i = 0, argc;
 455         enum cmd_error_code cmd_ret;
 456         struct cmd_struct *cmd;
 457
 458         if (!argv) {
 459                 ERR("No action specified for snapshot command.");
 460                 cmd_ret = CMD_ERROR;
 461                 goto end;
 462         }
 463
 464         if ((!opt_ctrl_url && opt_data_url) ||
 465                         (opt_ctrl_url && !opt_data_url)) {
 466                 ERR("URLs must be specified for both data and control");
 467                 cmd_ret = CMD_ERROR;
 468                 goto end;
 469         }
 470
 471         argc = count_arguments(argv);
 472         /* popt should have passed NULL if no arguments are present. */
 473         assert(argc > 0);
 474
 475         cmd = &actions[i];
 476         while (cmd->func != NULL) {
 477                 /* Find command */
 478                 if (strcmp(argv[0], cmd->name) == 0) {
 479                         int result;
 480
 481                         if (lttng_opt_mi) {
 482                                 /* Action element */
 483                                 mi_ret = mi_lttng_writer_open_element(writer,
 484                                                 mi_lttng_element_command_action);
 485                                 if (mi_ret) {
 486                                         cmd_ret = CMD_ERROR;
 487                                         goto end;
 488                                 }
 489
 490                                 /* Name of the action */
 491                                 mi_ret = mi_lttng_writer_write_element_string(writer,
 492                                                 config_element_name, argv[0]);
 493                                 if (mi_ret) {
 494                                         cmd_ret = CMD_ERROR;
 495                                         goto end;
 496                                 }
 497
 498                                 /* Open output element */
 499                                 mi_ret = mi_lttng_writer_open_element(writer,
 500                                                 mi_lttng_element_command_output);
 501                                 if (mi_ret) {
 502                                         cmd_ret = CMD_ERROR;
 503                                         goto end;
 504                                 }
 505                         }
 506
 507                         result = cmd->func(argc, argv);
 508                         if (result) {
 509                                 switch (-result) {
 510                                 case LTTNG_ERR_SNAPSHOT_NODATA:
 511                                         WARN("%s", lttng_strerror(result));
 512
 513                                         /*  A warning is fine since the user has no control on
 514                                          *  whether or not applications (or the kernel) have
 515                                          *  produced any event between the start of the tracing
 516                                          *  session and the recording of the snapshot. MI wise
 517                                          *  the command is not a success since nothing was
 518                                          *  recorded.
 519                                          */
 520                                         cmd_ret = CMD_SUCCESS;
 521                                         break;
 522                                 default:
 523                                         ERR("%s", lttng_strerror(result));
 524                                         cmd_ret = CMD_ERROR;
 525                                         break;
 526                                 }
 527                         } else {
 528                                 cmd_ret = CMD_SUCCESS;
 529                         }
 530
 531
 532                         if (lttng_opt_mi) {
 533                                 /* Close output and action element */
 534                                 mi_ret = mi_lttng_close_multi_element(writer, 2);
 535                                 if (mi_ret) {
 536                                         cmd_ret = CMD_ERROR;
 537                                         goto end;
 538                                 }
 539                         }
 540                         goto end;
 541                 }
 542                 i++;
 543                 cmd = &actions[i];
 544         }
 545
 546         cmd_ret = CMD_UNDEFINED;
 547
 548 end:
 549         return cmd_ret;
 550 }
 551 /*
 552  * The 'snapshot <cmd> <options>' first level command
 553  */
 554 int cmd_snapshot(int argc, const char **argv)
 555 {
 556         int opt;
 557         int mi_ret;
 558         enum cmd_error_code cmd_ret = CMD_SUCCESS;
 559         char *session_name = NULL;
 560         static poptContext pc;
 561
 562         pc = poptGetContext(NULL, argc, argv, snapshot_opts, 0);
 563         poptReadDefaultConfig(pc, 0);
 564
 565         /* Mi check */
 566         if (lttng_opt_mi) {
 567                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 568                 if (!writer) {
 569                         cmd_ret = CMD_ERROR;
 570                         goto end;
 571                 }
 572
 573                 /* Open command element */
 574                 mi_ret = mi_lttng_writer_command_open(writer,
 575                                 mi_lttng_element_command_snapshot);
 576                 if (mi_ret) {
 577                         cmd_ret = CMD_ERROR;
 578                         goto end;
 579                 }
 580
 581                 /* Open output element */
 582                 mi_ret = mi_lttng_writer_open_element(writer,
 583                                 mi_lttng_element_command_output);
 584                 if (mi_ret) {
 585                         cmd_ret = CMD_ERROR;
 586                         goto end;
 587                 }
 588         }
 589
 590         while ((opt = poptGetNextOpt(pc)) != -1) {
 591                 switch (opt) {
 592                 case OPT_HELP:
 593                 {
 594                         int ret;
 595
 596                         /* SHOW_HELP assigns to ret. */
 597                         SHOW_HELP();
 598                         cmd_ret = ret;
 599                         goto end;
 600                 }
 601                 case OPT_LIST_OPTIONS:
 602                         list_cmd_options(stdout, snapshot_opts);
 603                         goto end;
 604                 case OPT_LIST_COMMANDS:
 605                         list_commands(actions, stdout);
 606                         goto end;
 607                 case OPT_MAX_SIZE:
 608                 {
 609                         uint64_t val;
 610                         const char *opt = poptGetOptArg(pc);
 611
 612                         if (utils_parse_size_suffix((char *) opt, &val) < 0) {
 613                                 ERR("Unable to handle max-size value %s", opt);
 614                                 cmd_ret = CMD_ERROR;
 615                                 goto end;
 616                         }
 617
 618                         opt_max_size = val;
 619
 620                         break;
 621                 }
 622                 default:
 623                         cmd_ret = CMD_UNDEFINED;
 624                         goto end;
 625                 }
 626         }
 627
 628         if (!opt_session_name) {
 629                 session_name = get_session_name();
 630                 if (session_name == NULL) {
 631                         cmd_ret = CMD_ERROR;
 632                         goto end;
 633                 }
 634                 current_session_name = session_name;
 635         } else {
 636                 current_session_name = opt_session_name;
 637         }
 638
 639         cmd_ret = handle_command(poptGetArgs(pc));
 640
 641         if (lttng_opt_mi) {
 642                 /* Close output element */
 643                 mi_ret = mi_lttng_writer_close_element(writer);
 644                 if (mi_ret) {
 645                         cmd_ret = CMD_ERROR;
 646                         goto end;
 647                 }
 648
 649                 /* Success ? */
 650                 mi_ret = mi_lttng_writer_write_element_bool(writer,
 651                                 mi_lttng_element_command_success,
 652                                 cmd_ret == CMD_SUCCESS);
 653                 if (mi_ret) {
 654                         cmd_ret = CMD_ERROR;
 655                         goto end;
 656                 }
 657
 658                 /* Command element close */
 659                 mi_ret = mi_lttng_writer_command_close(writer);
 660                 if (mi_ret) {
 661                         cmd_ret = CMD_ERROR;
 662                         goto end;
 663                 }
 664         }
 665
 666 end:
 667         /* Mi clean-up */
 668         if (writer && mi_lttng_writer_destroy(writer)) {
 669                 cmd_ret = CMD_ERROR;
 670         }
 671
 672         if (!opt_session_name) {
 673                 free(session_name);
 674         }
 675
 676         poptFreeContext(pc);
 677         return cmd_ret;
 678 }