src/bin/lttng/commands/enable_channels.cpp

   1 /*
   2  * Copyright (C) 2011 EfficiOS Inc.
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include "../command.hpp"
  10 #include "../utils.hpp"
  11
  12 #include <common/mi-lttng.hpp>
  13 #include <common/sessiond-comm/sessiond-comm.hpp>
  14 #include <common/lttng-kernel.hpp>
  15 #include <common/utils.hpp>
  16
  17 #include <lttng/domain-internal.hpp>
  18
  19 #include <ctype.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
  29 static struct lttng_channel chan_opts;
  30 static int opt_kernel;
  31 static char *opt_session_name;
  32 static int opt_userspace;
  33 static char *opt_output;
  34 static int opt_buffer_uid;
  35 static int opt_buffer_pid;
  36 static int opt_buffer_global;
  37 static struct {
  38         bool set;
  39         uint64_t interval;
  40 } opt_monitor_timer;
  41 static struct {
  42         bool set;
  43         int64_t value;
  44 } opt_blocking_timeout;
  45
  46 static struct mi_writer *writer;
  47
  48 #ifdef LTTNG_EMBED_HELP
  49 static const char help_msg[] =
  50 #include <lttng-enable-channel.1.h>
  51         ;
  52 #endif
  53
  54 enum {
  55         OPT_HELP = 1,
  56         OPT_DISCARD,
  57         OPT_OVERWRITE,
  58         OPT_SUBBUF_SIZE,
  59         OPT_NUM_SUBBUF,
  60         OPT_SWITCH_TIMER,
  61         OPT_MONITOR_TIMER,
  62         OPT_READ_TIMER,
  63         OPT_USERSPACE,
  64         OPT_LIST_OPTIONS,
  65         OPT_TRACEFILE_SIZE,
  66         OPT_TRACEFILE_COUNT,
  67         OPT_BLOCKING_TIMEOUT,
  68 };
  69
  70 static struct lttng_handle *handle;
  71
  72 const char *output_mmap = "mmap";
  73 const char *output_splice = "splice";
  74
  75 static struct poptOption long_options[] = {
  76         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  77         { "help", 'h', POPT_ARG_NONE, nullptr, OPT_HELP, nullptr, nullptr },
  78         { "session", 's', POPT_ARG_STRING, &opt_session_name, 0, nullptr, nullptr },
  79         { "kernel", 'k', POPT_ARG_VAL, &opt_kernel, 1, nullptr, nullptr },
  80         { "userspace", 'u', POPT_ARG_NONE, nullptr, OPT_USERSPACE, nullptr, nullptr },
  81         { "discard", 0, POPT_ARG_NONE, nullptr, OPT_DISCARD, nullptr, nullptr },
  82         { "overwrite", 0, POPT_ARG_NONE, nullptr, OPT_OVERWRITE, nullptr, nullptr },
  83         { "subbuf-size", 0, POPT_ARG_STRING, nullptr, OPT_SUBBUF_SIZE, nullptr, nullptr },
  84         { "num-subbuf", 0, POPT_ARG_INT, nullptr, OPT_NUM_SUBBUF, nullptr, nullptr },
  85         { "switch-timer", 0, POPT_ARG_INT, nullptr, OPT_SWITCH_TIMER, nullptr, nullptr },
  86         { "monitor-timer", 0, POPT_ARG_INT, nullptr, OPT_MONITOR_TIMER, nullptr, nullptr },
  87         { "read-timer", 0, POPT_ARG_INT, nullptr, OPT_READ_TIMER, nullptr, nullptr },
  88         { "list-options", 0, POPT_ARG_NONE, nullptr, OPT_LIST_OPTIONS, nullptr, nullptr },
  89         { "output", 0, POPT_ARG_STRING, &opt_output, 0, nullptr, nullptr },
  90         { "buffers-uid", 0, POPT_ARG_VAL, &opt_buffer_uid, 1, nullptr, nullptr },
  91         { "buffers-pid", 0, POPT_ARG_VAL, &opt_buffer_pid, 1, nullptr, nullptr },
  92         { "buffers-global", 0, POPT_ARG_VAL, &opt_buffer_global, 1, nullptr, nullptr },
  93         { "tracefile-size", 'C', POPT_ARG_INT, nullptr, OPT_TRACEFILE_SIZE, nullptr, nullptr },
  94         { "tracefile-count", 'W', POPT_ARG_INT, nullptr, OPT_TRACEFILE_COUNT, nullptr, nullptr },
  95         { "blocking-timeout", 0, POPT_ARG_INT, nullptr, OPT_BLOCKING_TIMEOUT, nullptr, nullptr },
  96         { nullptr, 0, 0, nullptr, 0, nullptr, nullptr }
  97 };
  98
  99 /*
 100  * Set default attributes depending on those already defined from the command
 101  * line.
 102  */
 103 static void set_default_attr(struct lttng_domain *dom)
 104 {
 105         struct lttng_channel_attr default_attr;
 106
 107         memset(&default_attr, 0, sizeof(default_attr));
 108
 109         /* Set attributes */
 110         lttng_channel_set_default_attr(dom, &default_attr);
 111
 112         if (chan_opts.attr.overwrite == -1) {
 113                 chan_opts.attr.overwrite = default_attr.overwrite;
 114         }
 115         if (chan_opts.attr.subbuf_size == -1) {
 116                 chan_opts.attr.subbuf_size = default_attr.subbuf_size;
 117         }
 118         if (chan_opts.attr.num_subbuf == -1) {
 119                 chan_opts.attr.num_subbuf = default_attr.num_subbuf;
 120         }
 121         if (chan_opts.attr.switch_timer_interval == -1) {
 122                 chan_opts.attr.switch_timer_interval = default_attr.switch_timer_interval;
 123         }
 124         if (chan_opts.attr.read_timer_interval == -1) {
 125                 chan_opts.attr.read_timer_interval = default_attr.read_timer_interval;
 126         }
 127         if ((int) chan_opts.attr.output == -1) {
 128                 chan_opts.attr.output = default_attr.output;
 129         }
 130         if (chan_opts.attr.tracefile_count == -1) {
 131                 chan_opts.attr.tracefile_count = default_attr.tracefile_count;
 132         }
 133         if (chan_opts.attr.tracefile_size == -1) {
 134                 chan_opts.attr.tracefile_size = default_attr.tracefile_size;
 135         }
 136 }
 137
 138 /*
 139  * Adding channel using the lttng API.
 140  */
 141 static int enable_channel(char *session_name, char *channel_list)
 142 {
 143         struct lttng_channel *channel = nullptr;
 144         int ret = CMD_SUCCESS, warn = 0, error = 0, success = 0;
 145         enum lttng_kernel_tracer_status kernel_tracer_status;
 146         char *channel_name;
 147         struct lttng_domain dom;
 148
 149         memset(&dom, 0, sizeof(dom));
 150
 151         /* Validate options. */
 152         if (opt_kernel) {
 153                 if (opt_blocking_timeout.set) {
 154                         ERR("Retry timeout option not supported for kernel domain (-k)");
 155                         ret = CMD_ERROR;
 156                         goto error;
 157                 }
 158         }
 159
 160         /* Create lttng domain */
 161         if (opt_kernel) {
 162                 dom.type = LTTNG_DOMAIN_KERNEL;
 163                 dom.buf_type = LTTNG_BUFFER_GLOBAL;
 164                 if (opt_buffer_uid || opt_buffer_pid) {
 165                         ERR("Buffer type not supported for domain -k");
 166                         ret = CMD_ERROR;
 167                         goto error;
 168                 }
 169         } else if (opt_userspace) {
 170                 dom.type = LTTNG_DOMAIN_UST;
 171                 if (opt_buffer_pid) {
 172                         dom.buf_type = LTTNG_BUFFER_PER_PID;
 173                 } else {
 174                         if (opt_buffer_global) {
 175                                 ERR("Buffer type not supported for domain -u");
 176                                 ret = CMD_ERROR;
 177                                 goto error;
 178                         }
 179                         dom.buf_type = LTTNG_BUFFER_PER_UID;
 180                 }
 181         } else {
 182                 /* Checked by the caller. */
 183                 abort();
 184         }
 185
 186         set_default_attr(&dom);
 187
 188         if (chan_opts.attr.tracefile_size == 0 && chan_opts.attr.tracefile_count) {
 189                 ERR("Missing option --tracefile-size. "
 190                     "A file count without a size won't do anything.");
 191                 ret = CMD_ERROR;
 192                 goto error;
 193         }
 194
 195         if ((chan_opts.attr.tracefile_size > 0) &&
 196             (chan_opts.attr.tracefile_size < chan_opts.attr.subbuf_size)) {
 197                 WARN("Tracefile size rounded up from (%" PRIu64 ") to subbuffer size (%" PRIu64 ")",
 198                      chan_opts.attr.tracefile_size,
 199                      chan_opts.attr.subbuf_size);
 200                 chan_opts.attr.tracefile_size = chan_opts.attr.subbuf_size;
 201         }
 202
 203         /* Setting channel output */
 204         if (opt_output) {
 205                 if (!strncmp(output_mmap, opt_output, strlen(output_mmap))) {
 206                         chan_opts.attr.output = LTTNG_EVENT_MMAP;
 207                 } else if (!strncmp(output_splice, opt_output, strlen(output_splice))) {
 208                         chan_opts.attr.output = LTTNG_EVENT_SPLICE;
 209                 } else {
 210                         ERR("Unknown output type %s. Possible values are: %s, %s\n",
 211                             opt_output,
 212                             output_mmap,
 213                             output_splice);
 214                         ret = CMD_ERROR;
 215                         goto error;
 216                 }
 217         }
 218
 219         handle = lttng_create_handle(session_name, &dom);
 220         if (handle == nullptr) {
 221                 ret = -1;
 222                 goto error;
 223         }
 224
 225         /* Mi open channels element */
 226         if (lttng_opt_mi) {
 227                 LTTNG_ASSERT(writer);
 228                 ret = mi_lttng_channels_open(writer);
 229                 if (ret) {
 230                         ret = CMD_ERROR;
 231                         goto error;
 232                 }
 233         }
 234
 235         /* Strip channel list (format: chan1,chan2,...) */
 236         channel_name = strtok(channel_list, ",");
 237         while (channel_name != nullptr) {
 238                 void *extended_ptr;
 239
 240                 /* Validate channel name's length */
 241                 if (strlen(channel_name) >= sizeof(chan_opts.name)) {
 242                         ERR("Channel name is too long (max. %zu characters)",
 243                             sizeof(chan_opts.name) - 1);
 244                         error = 1;
 245                         goto skip_enable;
 246                 }
 247
 248                 /*
 249                  * A dynamically-allocated channel is used in order to allow
 250                  * the configuration of extended attributes (post-2.9).
 251                  */
 252                 channel = lttng_channel_create(&dom);
 253                 if (!channel) {
 254                         ERR("Unable to create channel object");
 255                         error = 1;
 256                         goto error;
 257                 }
 258
 259                 /* Copy channel name */
 260                 strcpy(channel->name, channel_name);
 261                 channel->enabled = 1;
 262                 extended_ptr = channel->attr.extended.ptr;
 263                 memcpy(&channel->attr, &chan_opts.attr, sizeof(chan_opts.attr));
 264                 channel->attr.extended.ptr = extended_ptr;
 265                 if (opt_monitor_timer.set) {
 266                         ret = lttng_channel_set_monitor_timer_interval(channel,
 267                                                                        opt_monitor_timer.interval);
 268                         if (ret) {
 269                                 ERR("Failed to set the channel's monitor timer interval");
 270                                 error = 1;
 271                                 goto error;
 272                         }
 273                 }
 274                 if (opt_blocking_timeout.set) {
 275                         ret = lttng_channel_set_blocking_timeout(channel,
 276                                                                  opt_blocking_timeout.value);
 277                         if (ret) {
 278                                 ERR("Failed to set the channel's blocking timeout");
 279                                 error = 1;
 280                                 goto error;
 281                         }
 282                 }
 283
 284                 DBG("Enabling channel %s", channel_name);
 285
 286                 ret = lttng_enable_channel(handle, channel);
 287                 if (ret < 0) {
 288                         success = 0;
 289                         switch (-ret) {
 290                         case LTTNG_ERR_KERN_CHAN_EXIST:
 291                         case LTTNG_ERR_UST_CHAN_EXIST:
 292                         case LTTNG_ERR_CHAN_EXIST:
 293                                 WARN("Channel %s: %s (session %s)",
 294                                      channel_name,
 295                                      lttng_strerror(ret),
 296                                      session_name);
 297                                 warn = 1;
 298                                 break;
 299                         case LTTNG_ERR_INVALID_CHANNEL_NAME:
 300                                 ERR("Invalid channel name: \"%s\". "
 301                                     "Channel names may not start with '.', and "
 302                                     "may not contain '/'.",
 303                                     channel_name);
 304                                 error = 1;
 305                                 break;
 306                         default:
 307                                 ERR("Channel %s: %s (session %s)",
 308                                     channel_name,
 309                                     lttng_strerror(ret),
 310                                     session_name);
 311                                 error = 1;
 312                                 break;
 313                         }
 314                         /*
 315                          * Ask the sessiond for the more details on the status of the kernel tracer.
 316                          */
 317                         ret = lttng_get_kernel_tracer_status(&kernel_tracer_status);
 318                         if (ret < 0) {
 319                                 ERR("Failed to get kernel tracer status: %s", lttng_strerror(ret));
 320                         } else {
 321                                 switch (kernel_tracer_status) {
 322                                 case LTTNG_KERNEL_TRACER_STATUS_INITIALIZED:
 323                                         break;
 324                                 case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_UNKNOWN:
 325                                         MSG("\tKernel module loading failed");
 326                                         break;
 327                                 case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_MISSING:
 328                                         MSG("\tMissing one or more required kernel modules");
 329                                         break;
 330                                 case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_SIGNATURE:
 331                                         MSG("\tKernel module signature error prevented loading of one or more required kernel modules");
 332                                         break;
 333                                 case LTTNG_KERNEL_TRACER_STATUS_ERR_NEED_ROOT:
 334                                         MSG("\tlttng-sessiond isn't running as root");
 335                                         break;
 336                                 case LTTNG_KERNEL_TRACER_STATUS_ERR_NOTIFIER:
 337                                         MSG("\tFailed to setup notifiers");
 338                                         break;
 339                                 case LTTNG_KERNEL_TRACER_STATUS_ERR_OPEN_PROC_LTTNG:
 340                                         MSG("\tlttng-sessiond failed to open proc lttng");
 341                                         break;
 342                                 case LTTNG_KERNEL_TRACER_STATUS_ERR_VERSION_MISMATCH:
 343                                         MSG("\tVersion mismatch between kernel tracer and kernel tracer ABI");
 344                                         break;
 345                                 default:
 346                                         MSG("\tUnknown kernel tracer status (%d)", kernel_tracer_status);
 347                                         break;
 348                                 }
 349                                 MSG("\tConsult lttng-sessiond logs for more information");
 350                         }
 351                 } else {
 352                         MSG("%s channel %s enabled for session %s",
 353                             lttng_domain_type_str(dom.type),
 354                             channel_name,
 355                             session_name);
 356                         success = 1;
 357                 }
 358
 359         skip_enable:
 360                 if (lttng_opt_mi) {
 361                         /* Mi print the channel element and leave it open */
 362                         ret = mi_lttng_channel(writer, channel, 1);
 363                         if (ret) {
 364                                 ret = CMD_ERROR;
 365                                 goto error;
 366                         }
 367
 368                         /* Individual Success ? */
 369                         ret = mi_lttng_writer_write_element_bool(
 370                                 writer, mi_lttng_element_command_success, success);
 371                         if (ret) {
 372                                 ret = CMD_ERROR;
 373                                 goto error;
 374                         }
 375
 376                         /* Close channel element */
 377                         ret = mi_lttng_writer_close_element(writer);
 378                         if (ret) {
 379                                 ret = CMD_ERROR;
 380                                 goto error;
 381                         }
 382                 }
 383
 384                 /* Next channel */
 385                 channel_name = strtok(nullptr, ",");
 386                 lttng_channel_destroy(channel);
 387                 channel = nullptr;
 388         }
 389
 390         if (lttng_opt_mi) {
 391                 /* Close channels element */
 392                 ret = mi_lttng_writer_close_element(writer);
 393                 if (ret) {
 394                         ret = CMD_ERROR;
 395                         goto error;
 396                 }
 397         }
 398
 399         ret = CMD_SUCCESS;
 400
 401 error:
 402         if (channel) {
 403                 lttng_channel_destroy(channel);
 404         }
 405         /* If more important error happen bypass the warning */
 406         if (!ret && warn) {
 407                 ret = CMD_WARNING;
 408         }
 409         /* If more important error happen bypass the warning */
 410         if (!ret && error) {
 411                 ret = CMD_ERROR;
 412         }
 413
 414         lttng_destroy_handle(handle);
 415
 416         return ret;
 417 }
 418
 419 /*
 420  * Default value for channel configuration.
 421  */
 422 static void init_channel_config()
 423 {
 424         /*
 425          * Put -1 everywhere so we can identify those set by the command line and
 426          * those needed to be set by the default values.
 427          */
 428         memset(&chan_opts.attr, -1, sizeof(chan_opts.attr));
 429         chan_opts.attr.extended.ptr = nullptr;
 430 }
 431
 432 /*
 433  * Add channel to trace session
 434  */
 435 int cmd_enable_channels(int argc, const char **argv)
 436 {
 437         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 438         static poptContext pc;
 439         char *session_name = nullptr;
 440         char *channel_list = nullptr;
 441         char *opt_arg = nullptr;
 442         const char *arg_channel_list = nullptr;
 443         const char *leftover = nullptr;
 444
 445         init_channel_config();
 446
 447         pc = poptGetContext(nullptr, argc, argv, long_options, 0);
 448         poptReadDefaultConfig(pc, 0);
 449
 450         while ((opt = poptGetNextOpt(pc)) != -1) {
 451                 switch (opt) {
 452                 case OPT_HELP:
 453                         SHOW_HELP();
 454                         goto end;
 455                 case OPT_DISCARD:
 456                         chan_opts.attr.overwrite = 0;
 457                         DBG("Channel set to discard");
 458                         break;
 459                 case OPT_OVERWRITE:
 460                         chan_opts.attr.overwrite = 1;
 461                         DBG("Channel set to overwrite");
 462                         break;
 463                 case OPT_SUBBUF_SIZE:
 464                 {
 465                         uint64_t rounded_size;
 466                         int order;
 467
 468                         /* Parse the size */
 469                         opt_arg = poptGetOptArg(pc);
 470                         if (utils_parse_size_suffix(opt_arg, &chan_opts.attr.subbuf_size) < 0 ||
 471                             !chan_opts.attr.subbuf_size) {
 472                                 ERR("Wrong value in --subbuf-size parameter: %s", opt_arg);
 473                                 ret = CMD_ERROR;
 474                                 goto end;
 475                         }
 476
 477                         order = get_count_order_u64(chan_opts.attr.subbuf_size);
 478                         LTTNG_ASSERT(order >= 0);
 479                         rounded_size = 1ULL << order;
 480                         if (rounded_size < chan_opts.attr.subbuf_size) {
 481                                 ERR("The subbuf size (%" PRIu64 ") is rounded and overflows!",
 482                                     chan_opts.attr.subbuf_size);
 483                                 ret = CMD_ERROR;
 484                                 goto end;
 485                         }
 486
 487                         if (rounded_size != chan_opts.attr.subbuf_size) {
 488                                 WARN("The subbuf size (%" PRIu64
 489                                      ") is rounded to the next power of 2 (%" PRIu64 ")",
 490                                      chan_opts.attr.subbuf_size,
 491                                      rounded_size);
 492                                 chan_opts.attr.subbuf_size = rounded_size;
 493                         }
 494
 495                         /* Should now be power of 2 */
 496                         LTTNG_ASSERT(
 497                                 !((chan_opts.attr.subbuf_size - 1) & chan_opts.attr.subbuf_size));
 498
 499                         DBG("Channel subbuf size set to %" PRIu64, chan_opts.attr.subbuf_size);
 500                         break;
 501                 }
 502                 case OPT_NUM_SUBBUF:
 503                 {
 504                         uint64_t rounded_size;
 505                         int order;
 506
 507                         errno = 0;
 508                         opt_arg = poptGetOptArg(pc);
 509                         chan_opts.attr.num_subbuf = strtoull(opt_arg, nullptr, 0);
 510                         if (errno != 0 || !chan_opts.attr.num_subbuf || !isdigit(opt_arg[0])) {
 511                                 ERR("Wrong value in --num-subbuf parameter: %s", opt_arg);
 512                                 ret = CMD_ERROR;
 513                                 goto end;
 514                         }
 515
 516                         order = get_count_order_u64(chan_opts.attr.num_subbuf);
 517                         LTTNG_ASSERT(order >= 0);
 518                         rounded_size = 1ULL << order;
 519                         if (rounded_size < chan_opts.attr.num_subbuf) {
 520                                 ERR("The number of subbuffers (%" PRIu64
 521                                     ") is rounded and overflows!",
 522                                     chan_opts.attr.num_subbuf);
 523                                 ret = CMD_ERROR;
 524                                 goto end;
 525                         }
 526
 527                         if (rounded_size != chan_opts.attr.num_subbuf) {
 528                                 WARN("The number of subbuffers (%" PRIu64
 529                                      ") is rounded to the next power of 2 (%" PRIu64 ")",
 530                                      chan_opts.attr.num_subbuf,
 531                                      rounded_size);
 532                                 chan_opts.attr.num_subbuf = rounded_size;
 533                         }
 534
 535                         /* Should now be power of 2 */
 536                         LTTNG_ASSERT(
 537                                 !((chan_opts.attr.num_subbuf - 1) & chan_opts.attr.num_subbuf));
 538
 539                         DBG("Channel subbuf num set to %" PRIu64, chan_opts.attr.num_subbuf);
 540                         break;
 541                 }
 542                 case OPT_SWITCH_TIMER:
 543                 {
 544                         uint64_t v;
 545
 546                         errno = 0;
 547                         opt_arg = poptGetOptArg(pc);
 548
 549                         if (utils_parse_time_suffix(opt_arg, &v) < 0) {
 550                                 ERR("Wrong value for --switch-timer parameter: %s", opt_arg);
 551                                 ret = CMD_ERROR;
 552                                 goto end;
 553                         }
 554
 555                         if (v != (uint32_t) v) {
 556                                 ERR("32-bit overflow in --switch-timer parameter: %s", opt_arg);
 557                                 ret = CMD_ERROR;
 558                                 goto end;
 559                         }
 560                         chan_opts.attr.switch_timer_interval = (uint32_t) v;
 561                         DBG("Channel switch timer interval set to %d %s",
 562                             chan_opts.attr.switch_timer_interval,
 563                             USEC_UNIT);
 564                         break;
 565                 }
 566                 case OPT_READ_TIMER:
 567                 {
 568                         uint64_t v;
 569
 570                         errno = 0;
 571                         opt_arg = poptGetOptArg(pc);
 572
 573                         if (utils_parse_time_suffix(opt_arg, &v) < 0) {
 574                                 ERR("Wrong value for --read-timer parameter: %s", opt_arg);
 575                                 ret = CMD_ERROR;
 576                                 goto end;
 577                         }
 578
 579                         if (v != (uint32_t) v) {
 580                                 ERR("32-bit overflow in --read-timer parameter: %s", opt_arg);
 581                                 ret = CMD_ERROR;
 582                                 goto end;
 583                         }
 584                         chan_opts.attr.read_timer_interval = (uint32_t) v;
 585                         DBG("Channel read timer interval set to %d %s",
 586                             chan_opts.attr.read_timer_interval,
 587                             USEC_UNIT);
 588                         break;
 589                 }
 590                 case OPT_MONITOR_TIMER:
 591                 {
 592                         uint64_t v;
 593
 594                         errno = 0;
 595                         opt_arg = poptGetOptArg(pc);
 596
 597                         if (utils_parse_time_suffix(opt_arg, &v) < 0) {
 598                                 ERR("Wrong value for --monitor-timer parameter: %s", opt_arg);
 599                                 ret = CMD_ERROR;
 600                                 goto end;
 601                         }
 602                         opt_monitor_timer.interval = (uint64_t) v;
 603                         opt_monitor_timer.set = true;
 604                         DBG("Channel monitor timer interval set to %" PRIu64 " %s",
 605                             opt_monitor_timer.interval,
 606                             USEC_UNIT);
 607                         break;
 608                 }
 609                 case OPT_BLOCKING_TIMEOUT:
 610                 {
 611                         uint64_t v;
 612                         long long v_msec;
 613
 614                         errno = 0;
 615                         opt_arg = poptGetOptArg(pc);
 616
 617                         if (strcmp(opt_arg, "inf") == 0) {
 618                                 opt_blocking_timeout.value = (int64_t) -1;
 619                                 opt_blocking_timeout.set = true;
 620                                 DBG("Channel blocking timeout set to infinity");
 621                                 break;
 622                         }
 623
 624                         if (utils_parse_time_suffix(opt_arg, &v) < 0) {
 625                                 ERR("Wrong value for --blocking-timeout parameter: %s", opt_arg);
 626                                 ret = CMD_ERROR;
 627                                 goto end;
 628                         }
 629
 630                         /*
 631                          * While LTTng-UST and LTTng-tools will accept a
 632                          * blocking timeout expressed in µs, the current
 633                          * tracer implementation relies on poll() which
 634                          * takes an "int timeout" parameter expressed in
 635                          * msec.
 636                          *
 637                          * Since the error reporting from the tracer is
 638                          * not precise, we perform this check here to
 639                          * provide a helpful error message in case of
 640                          * overflow.
 641                          *
 642                          * The setter (liblttng-ctl) also performs an
 643                          * equivalent check.
 644                          */
 645                         v_msec = v / 1000;
 646                         if (v_msec != (int32_t) v_msec) {
 647                                 ERR("32-bit milliseconds overflow in --blocking-timeout parameter: %s",
 648                                     opt_arg);
 649                                 ret = CMD_ERROR;
 650                                 goto end;
 651                         }
 652
 653                         opt_blocking_timeout.value = (int64_t) v;
 654                         opt_blocking_timeout.set = true;
 655                         DBG("Channel blocking timeout set to %" PRId64 " %s%s",
 656                             opt_blocking_timeout.value,
 657                             USEC_UNIT,
 658                             opt_blocking_timeout.value == 0 ? " (non-blocking)" : "");
 659                         break;
 660                 }
 661                 case OPT_USERSPACE:
 662                         opt_userspace = 1;
 663                         break;
 664                 case OPT_TRACEFILE_SIZE:
 665                         opt_arg = poptGetOptArg(pc);
 666                         if (utils_parse_size_suffix(opt_arg, &chan_opts.attr.tracefile_size) < 0) {
 667                                 ERR("Wrong value in --tracefile-size parameter: %s", opt_arg);
 668                                 ret = CMD_ERROR;
 669                                 goto end;
 670                         }
 671                         DBG("Maximum tracefile size set to %" PRIu64,
 672                             chan_opts.attr.tracefile_size);
 673                         break;
 674                 case OPT_TRACEFILE_COUNT:
 675                 {
 676                         unsigned long v;
 677
 678                         errno = 0;
 679                         opt_arg = poptGetOptArg(pc);
 680                         v = strtoul(opt_arg, nullptr, 0);
 681                         if (errno != 0 || !isdigit(opt_arg[0])) {
 682                                 ERR("Wrong value in --tracefile-count parameter: %s", opt_arg);
 683                                 ret = CMD_ERROR;
 684                                 goto end;
 685                         }
 686                         if (v != (uint32_t) v) {
 687                                 ERR("32-bit overflow in --tracefile-count parameter: %s", opt_arg);
 688                                 ret = CMD_ERROR;
 689                                 goto end;
 690                         }
 691                         chan_opts.attr.tracefile_count = (uint32_t) v;
 692                         DBG("Maximum tracefile count set to %" PRIu64,
 693                             chan_opts.attr.tracefile_count);
 694                         break;
 695                 }
 696                 case OPT_LIST_OPTIONS:
 697                         list_cmd_options(stdout, long_options);
 698                         goto end;
 699                 default:
 700                         ret = CMD_UNDEFINED;
 701                         goto end;
 702                 }
 703
 704                 if (opt_arg) {
 705                         free(opt_arg);
 706                         opt_arg = nullptr;
 707                 }
 708         }
 709
 710         ret = print_missing_or_multiple_domains(opt_kernel + opt_userspace, false);
 711         if (ret) {
 712                 ret = CMD_ERROR;
 713                 goto end;
 714         }
 715
 716         if (chan_opts.attr.overwrite == 1 && opt_blocking_timeout.set &&
 717             opt_blocking_timeout.value != 0) {
 718                 ERR("You cannot specify --overwrite and --blocking-timeout=N, "
 719                     "where N is different than 0");
 720                 ret = CMD_ERROR;
 721                 goto end;
 722         }
 723
 724         /* Mi check */
 725         if (lttng_opt_mi) {
 726                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 727                 if (!writer) {
 728                         ret = -LTTNG_ERR_NOMEM;
 729                         goto end;
 730                 }
 731
 732                 /* Open command element */
 733                 ret = mi_lttng_writer_command_open(writer,
 734                                                    mi_lttng_element_command_enable_channels);
 735                 if (ret) {
 736                         ret = CMD_ERROR;
 737                         goto end;
 738                 }
 739
 740                 /* Open output element */
 741                 ret = mi_lttng_writer_open_element(writer, mi_lttng_element_command_output);
 742                 if (ret) {
 743                         ret = CMD_ERROR;
 744                         goto end;
 745                 }
 746         }
 747
 748         arg_channel_list = poptGetArg(pc);
 749         if (arg_channel_list == nullptr) {
 750                 ERR("Missing channel name.");
 751                 ret = CMD_ERROR;
 752                 success = 0;
 753                 goto mi_closing;
 754         }
 755
 756         channel_list = strdup(arg_channel_list);
 757         if (channel_list == nullptr) {
 758                 PERROR("Failed to copy channel name");
 759                 ret = CMD_ERROR;
 760                 success = 0;
 761                 goto mi_closing;
 762         }
 763
 764         leftover = poptGetArg(pc);
 765         if (leftover) {
 766                 ERR("Unknown argument: %s", leftover);
 767                 ret = CMD_ERROR;
 768                 success = 0;
 769                 goto mi_closing;
 770         }
 771
 772         if (!opt_session_name) {
 773                 session_name = get_session_name();
 774                 if (session_name == nullptr) {
 775                         command_ret = CMD_ERROR;
 776                         success = 0;
 777                         goto mi_closing;
 778                 }
 779         } else {
 780                 session_name = opt_session_name;
 781         }
 782
 783         command_ret = enable_channel(session_name, channel_list);
 784         if (command_ret) {
 785                 success = 0;
 786         }
 787
 788 mi_closing:
 789         /* Mi closing */
 790         if (lttng_opt_mi) {
 791                 /* Close  output element */
 792                 ret = mi_lttng_writer_close_element(writer);
 793                 if (ret) {
 794                         goto end;
 795                 }
 796
 797                 /* Success ? */
 798                 ret = mi_lttng_writer_write_element_bool(
 799                         writer, mi_lttng_element_command_success, success);
 800                 if (ret) {
 801                         goto end;
 802                 }
 803
 804                 /* Command element close */
 805                 ret = mi_lttng_writer_command_close(writer);
 806                 if (ret) {
 807                         goto end;
 808                 }
 809         }
 810
 811 end:
 812         /* Mi clean-up */
 813         if (writer && mi_lttng_writer_destroy(writer)) {
 814                 /* Preserve original error code */
 815                 ret = ret ? ret : LTTNG_ERR_MI_IO_FAIL;
 816         }
 817
 818         if (!opt_session_name && session_name) {
 819                 free(session_name);
 820         }
 821
 822         free(channel_list);
 823
 824         /* Overwrite ret if an error occurred when enable_channel */
 825         ret = command_ret ? command_ret : ret;
 826         poptFreeContext(pc);
 827         free(opt_arg);
 828         return ret;
 829 }