src/plugins/text/dmesg/dmesg.c

   1 /*
   2  * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
   3  * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to deal
   7  * in the Software without restriction, including without limitation the rights
   8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9  * copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 #define BT_COMP_LOG_SELF_COMP (dmesg_comp->self_comp)
  25 #define BT_LOG_OUTPUT_LEVEL (dmesg_comp->log_level)
  26 #define BT_LOG_TAG "PLUGIN/SRC.TEXT.DMESG"
  27 #include "plugins/comp-logging.h"
  28
  29 #include <stdbool.h>
  30 #include <string.h>
  31 #include <ctype.h>
  32 #include <stdio.h>
  33 #include "common/common.h"
  34 #include "common/assert.h"
  35 #include <babeltrace2/babeltrace.h>
  36 #include "compat/utc.h"
  37 #include "compat/stdio.h"
  38 #include <glib.h>
  39
  40 #define NSEC_PER_USEC 1000UL
  41 #define NSEC_PER_MSEC 1000000UL
  42 #define NSEC_PER_SEC 1000000000ULL
  43 #define USEC_PER_SEC 1000000UL
  44
  45 struct dmesg_component;
  46
  47 struct dmesg_msg_iter {
  48         struct dmesg_component *dmesg_comp;
  49         bt_self_message_iterator *pc_msg_iter; /* Weak */
  50         char *linebuf;
  51         size_t linebuf_len;
  52         FILE *fp;
  53         bt_message *tmp_event_msg;
  54         uint64_t last_clock_value;
  55
  56         enum {
  57                 STATE_EMIT_STREAM_BEGINNING,
  58                 STATE_EMIT_EVENT,
  59                 STATE_EMIT_STREAM_END,
  60                 STATE_DONE,
  61         } state;
  62 };
  63
  64 struct dmesg_component {
  65         bt_logging_level log_level;
  66
  67         struct {
  68                 GString *path;
  69                 bt_bool read_from_stdin;
  70                 bt_bool no_timestamp;
  71         } params;
  72
  73         bt_self_component_source *self_comp_src;
  74         bt_self_component *self_comp;
  75         bt_trace_class *trace_class;
  76         bt_stream_class *stream_class;
  77         bt_event_class *event_class;
  78         bt_trace *trace;
  79         bt_stream *stream;
  80         bt_clock_class *clock_class;
  81 };
  82
  83 static
  84 bt_field_class *create_event_payload_fc(struct dmesg_component *dmesg_comp,
  85                 bt_trace_class *trace_class)
  86 {
  87         bt_field_class *root_fc = NULL;
  88         bt_field_class *fc = NULL;
  89         int ret;
  90
  91         root_fc = bt_field_class_structure_create(trace_class);
  92         if (!root_fc) {
  93                 BT_COMP_LOGE_STR("Cannot create an empty structure field class object.");
  94                 goto error;
  95         }
  96
  97         fc = bt_field_class_string_create(trace_class);
  98         if (!fc) {
  99                 BT_COMP_LOGE_STR("Cannot create a string field class object.");
 100                 goto error;
 101         }
 102
 103         ret = bt_field_class_structure_append_member(root_fc,
 104                 "str", fc);
 105         if (ret) {
 106                 BT_COMP_LOGE("Cannot add `str` member to structure field class: "
 107                         "ret=%d", ret);
 108                 goto error;
 109         }
 110
 111         goto end;
 112
 113 error:
 114         BT_FIELD_CLASS_PUT_REF_AND_RESET(root_fc);
 115
 116 end:
 117         bt_field_class_put_ref(fc);
 118         return root_fc;
 119 }
 120
 121 static
 122 int create_meta(struct dmesg_component *dmesg_comp, bool has_ts)
 123 {
 124         bt_field_class *fc = NULL;
 125         int ret = 0;
 126
 127         dmesg_comp->trace_class = bt_trace_class_create(dmesg_comp->self_comp);
 128         if (!dmesg_comp->trace_class) {
 129                 BT_COMP_LOGE_STR("Cannot create an empty trace class object.");
 130                 goto error;
 131         }
 132
 133         dmesg_comp->stream_class = bt_stream_class_create(
 134                 dmesg_comp->trace_class);
 135         if (!dmesg_comp->stream_class) {
 136                 BT_COMP_LOGE_STR("Cannot create a stream class object.");
 137                 goto error;
 138         }
 139
 140         if (has_ts) {
 141                 dmesg_comp->clock_class = bt_clock_class_create(
 142                         dmesg_comp->self_comp);
 143                 if (!dmesg_comp->clock_class) {
 144                         BT_COMP_LOGE_STR("Cannot create clock class.");
 145                         goto error;
 146                 }
 147
 148                 /*
 149                  * The `dmesg` timestamp's origin is not the Unix epoch,
 150                  * it's the boot time.
 151                  */
 152                 bt_clock_class_set_origin_is_unix_epoch(dmesg_comp->clock_class,
 153                         BT_FALSE);
 154
 155                 ret = bt_stream_class_set_default_clock_class(
 156                         dmesg_comp->stream_class, dmesg_comp->clock_class);
 157                 if (ret) {
 158                         BT_COMP_LOGE_STR("Cannot set stream class's default clock class.");
 159                         goto error;
 160                 }
 161         }
 162
 163         dmesg_comp->event_class = bt_event_class_create(
 164                 dmesg_comp->stream_class);
 165         if (!dmesg_comp->event_class) {
 166                 BT_COMP_LOGE_STR("Cannot create an event class object.");
 167                 goto error;
 168         }
 169
 170         ret = bt_event_class_set_name(dmesg_comp->event_class, "string");
 171         if (ret) {
 172                 BT_COMP_LOGE_STR("Cannot set event class's name.");
 173                 goto error;
 174         }
 175
 176         fc = create_event_payload_fc(dmesg_comp, dmesg_comp->trace_class);
 177         if (!fc) {
 178                 BT_COMP_LOGE_STR("Cannot create event payload field class.");
 179                 goto error;
 180         }
 181
 182         ret = bt_event_class_set_payload_field_class(dmesg_comp->event_class, fc);
 183         if (ret) {
 184                 BT_COMP_LOGE_STR("Cannot set event class's event payload field class.");
 185                 goto error;
 186         }
 187
 188         goto end;
 189
 190 error:
 191         ret = -1;
 192
 193 end:
 194         bt_field_class_put_ref(fc);
 195         return ret;
 196 }
 197
 198 static
 199 int handle_params(struct dmesg_component *dmesg_comp,
 200                 const bt_value *params)
 201 {
 202         const bt_value *no_timestamp = NULL;
 203         const bt_value *path = NULL;
 204         const char *path_str;
 205         int ret = 0;
 206
 207         no_timestamp = bt_value_map_borrow_entry_value_const(params,
 208                 "no-extract-timestamp");
 209         if (no_timestamp) {
 210                 if (!bt_value_is_bool(no_timestamp)) {
 211                         BT_COMP_LOGE("Expecting a boolean value for the `no-extract-timestamp` parameter: "
 212                                 "type=%s",
 213                                 bt_common_value_type_string(
 214                                         bt_value_get_type(no_timestamp)));
 215                         goto error;
 216                 }
 217
 218                 dmesg_comp->params.no_timestamp =
 219                         bt_value_bool_get(no_timestamp);
 220         }
 221
 222         path = bt_value_map_borrow_entry_value_const(params, "path");
 223         if (path) {
 224                 if (dmesg_comp->params.read_from_stdin) {
 225                         BT_COMP_LOGE_STR("Cannot specify both `read-from-stdin` and `path` parameters.");
 226                         goto error;
 227                 }
 228
 229                 if (!bt_value_is_string(path)) {
 230                         BT_COMP_LOGE("Expecting a string value for the `path` parameter: "
 231                                 "type=%s",
 232                                 bt_common_value_type_string(
 233                                         bt_value_get_type(path)));
 234                         goto error;
 235                 }
 236
 237                 path_str = bt_value_string_get(path);
 238                 g_string_assign(dmesg_comp->params.path, path_str);
 239         } else {
 240                 dmesg_comp->params.read_from_stdin = true;
 241         }
 242
 243         goto end;
 244
 245 error:
 246         ret = -1;
 247
 248 end:
 249         return ret;
 250 }
 251
 252 static
 253 int create_stream_and_trace(struct dmesg_component *dmesg_comp)
 254 {
 255         int ret = 0;
 256         const char *trace_name = NULL;
 257         gchar *basename = NULL;
 258
 259         dmesg_comp->trace = bt_trace_create(dmesg_comp->trace_class);
 260         if (!dmesg_comp->trace) {
 261                 BT_COMP_LOGE_STR("Cannot create trace object.");
 262                 goto error;
 263         }
 264
 265         if (dmesg_comp->params.read_from_stdin) {
 266                 trace_name = "STDIN";
 267         } else {
 268                 basename = g_path_get_basename(dmesg_comp->params.path->str);
 269                 BT_ASSERT(basename);
 270
 271                 if (strcmp(basename, G_DIR_SEPARATOR_S) != 0 &&
 272                                 strcmp(basename, ".") != 0) {
 273                         trace_name = basename;
 274                 }
 275         }
 276
 277         if (trace_name) {
 278                 ret = bt_trace_set_name(dmesg_comp->trace, trace_name);
 279                 if (ret) {
 280                         BT_COMP_LOGE("Cannot set trace's name: name=\"%s\"",
 281                                 trace_name);
 282                         goto error;
 283                 }
 284         }
 285
 286         dmesg_comp->stream = bt_stream_create(dmesg_comp->stream_class,
 287                 dmesg_comp->trace);
 288         if (!dmesg_comp->stream) {
 289                 BT_COMP_LOGE_STR("Cannot create stream object.");
 290                 goto error;
 291         }
 292
 293         goto end;
 294
 295 error:
 296         ret = -1;
 297
 298 end:
 299         g_free(basename);
 300
 301         return ret;
 302 }
 303
 304 static
 305 int try_create_meta_stream(struct dmesg_component *dmesg_comp, bool has_ts)
 306 {
 307         int ret = 0;
 308
 309         if (dmesg_comp->trace) {
 310                 /* Already created */
 311                 goto end;
 312         }
 313
 314         ret = create_meta(dmesg_comp, has_ts);
 315         if (ret) {
 316                 BT_COMP_LOGE("Cannot create metadata objects: dmesg-comp-addr=%p",
 317                         dmesg_comp);
 318                 goto error;
 319         }
 320
 321         ret = create_stream_and_trace(dmesg_comp);
 322         if (ret) {
 323                 BT_COMP_LOGE("Cannot create stream object: "
 324                         "dmesg-comp-addr=%p", dmesg_comp);
 325                 goto error;
 326         }
 327
 328         goto end;
 329
 330 error:
 331         ret = -1;
 332
 333 end:
 334         return ret;
 335 }
 336
 337 static
 338 void destroy_dmesg_component(struct dmesg_component *dmesg_comp)
 339 {
 340         if (!dmesg_comp) {
 341                 return;
 342         }
 343
 344         if (dmesg_comp->params.path) {
 345                 g_string_free(dmesg_comp->params.path, TRUE);
 346         }
 347
 348         bt_trace_put_ref(dmesg_comp->trace);
 349         bt_stream_class_put_ref(dmesg_comp->stream_class);
 350         bt_event_class_put_ref(dmesg_comp->event_class);
 351         bt_stream_put_ref(dmesg_comp->stream);
 352         bt_clock_class_put_ref(dmesg_comp->clock_class);
 353         bt_trace_class_put_ref(dmesg_comp->trace_class);
 354         g_free(dmesg_comp);
 355 }
 356
 357 static
 358 bt_component_class_init_method_status create_port(
 359                 bt_self_component_source *self_comp)
 360 {
 361         bt_component_class_init_method_status status;
 362         bt_self_component_add_port_status add_port_status;
 363
 364         add_port_status = bt_self_component_source_add_output_port(self_comp,
 365                 "out", NULL, NULL);
 366         switch (add_port_status) {
 367         case BT_SELF_COMPONENT_ADD_PORT_STATUS_OK:
 368                 status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_OK;
 369                 break;
 370         case BT_SELF_COMPONENT_ADD_PORT_STATUS_ERROR:
 371                 status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_ERROR;
 372                 break;
 373         case BT_SELF_COMPONENT_ADD_PORT_STATUS_MEMORY_ERROR:
 374                 status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_MEMORY_ERROR;
 375                 break;
 376         default:
 377                 abort();
 378         }
 379
 380         return status;
 381 }
 382
 383 BT_HIDDEN
 384 bt_component_class_init_method_status dmesg_init(
 385                 bt_self_component_source *self_comp_src,
 386                 bt_value *params, void *init_method_data)
 387 {
 388         int ret = 0;
 389         struct dmesg_component *dmesg_comp = g_new0(struct dmesg_component, 1);
 390         bt_component_class_init_method_status status =
 391                 BT_COMPONENT_CLASS_INIT_METHOD_STATUS_OK;
 392         bt_self_component *self_comp =
 393                 bt_self_component_source_as_self_component(self_comp_src);
 394         const bt_component *comp = bt_self_component_as_component(self_comp);
 395         bt_logging_level log_level = bt_component_get_logging_level(comp);
 396
 397         if (!dmesg_comp) {
 398                 /* Implicit log level is not available here */
 399                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_comp,
 400                         "Failed to allocate one dmesg component structure.");
 401                 goto error;
 402         }
 403
 404         dmesg_comp->log_level = log_level;
 405         dmesg_comp->self_comp = self_comp;
 406         dmesg_comp->self_comp_src = self_comp_src;
 407         dmesg_comp->params.path = g_string_new(NULL);
 408         if (!dmesg_comp->params.path) {
 409                 BT_COMP_LOGE_STR("Failed to allocate a GString.");
 410                 goto error;
 411         }
 412
 413         ret = handle_params(dmesg_comp, params);
 414         if (ret) {
 415                 BT_COMP_LOGE("Invalid parameters: comp-addr=%p", self_comp);
 416                 goto error;
 417         }
 418
 419         if (!dmesg_comp->params.read_from_stdin &&
 420                         !g_file_test(dmesg_comp->params.path->str,
 421                         G_FILE_TEST_IS_REGULAR)) {
 422                 BT_COMP_LOGE("Input path is not a regular file: "
 423                         "comp-addr=%p, path=\"%s\"", self_comp,
 424                         dmesg_comp->params.path->str);
 425                 goto error;
 426         }
 427
 428         status = create_port(self_comp_src);
 429         if (status != BT_COMPONENT_CLASS_INIT_METHOD_STATUS_OK) {
 430                 goto error;
 431         }
 432
 433         bt_self_component_set_data(self_comp, dmesg_comp);
 434         BT_COMP_LOGI_STR("Component initialized.");
 435         goto end;
 436
 437 error:
 438         destroy_dmesg_component(dmesg_comp);
 439         bt_self_component_set_data(self_comp, NULL);
 440
 441         if (status >= 0) {
 442                 status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_ERROR;
 443         }
 444
 445 end:
 446         return status;
 447 }
 448
 449 BT_HIDDEN
 450 void dmesg_finalize(bt_self_component_source *self_comp)
 451 {
 452         destroy_dmesg_component(bt_self_component_get_data(
 453                 bt_self_component_source_as_self_component(self_comp)));
 454 }
 455
 456 static
 457 bt_message *create_init_event_msg_from_line(
 458                 struct dmesg_msg_iter *msg_iter,
 459                 const char *line, const char **new_start)
 460 {
 461         bt_event *event;
 462         bt_message *msg = NULL;
 463         bool has_timestamp = false;
 464         unsigned long sec, usec, msec;
 465         unsigned int year, mon, mday, hour, min;
 466         uint64_t ts = 0;
 467         int ret = 0;
 468         struct dmesg_component *dmesg_comp = msg_iter->dmesg_comp;
 469
 470         *new_start = line;
 471
 472         if (dmesg_comp->params.no_timestamp) {
 473                 goto skip_ts;
 474         }
 475
 476         /* Extract time from input line */
 477         if (sscanf(line, "[%lu.%lu] ", &sec, &usec) == 2) {
 478                 ts = (uint64_t) sec * USEC_PER_SEC + (uint64_t) usec;
 479
 480                 /*
 481                  * The clock class we use has a 1 GHz frequency: convert
 482                  * from µs to ns.
 483                  */
 484                 ts *= NSEC_PER_USEC;
 485                 has_timestamp = true;
 486         } else if (sscanf(line, "[%u-%u-%u %u:%u:%lu.%lu] ",
 487                         &year, &mon, &mday, &hour, &min,
 488                         &sec, &msec) == 7) {
 489                 time_t ep_sec;
 490                 struct tm ti;
 491
 492                 memset(&ti, 0, sizeof(ti));
 493                 ti.tm_year = year - 1900;       /* From 1900 */
 494                 ti.tm_mon = mon - 1;            /* 0 to 11 */
 495                 ti.tm_mday = mday;
 496                 ti.tm_hour = hour;
 497                 ti.tm_min = min;
 498                 ti.tm_sec = sec;
 499
 500                 ep_sec = bt_timegm(&ti);
 501                 if (ep_sec != (time_t) -1) {
 502                         ts = (uint64_t) ep_sec * NSEC_PER_SEC
 503                                 + (uint64_t) msec * NSEC_PER_MSEC;
 504                 }
 505
 506                 has_timestamp = true;
 507         }
 508
 509         if (has_timestamp) {
 510                 /* Set new start for the message portion of the line */
 511                 *new_start = strchr(line, ']');
 512                 BT_ASSERT(*new_start);
 513                 (*new_start)++;
 514
 515                 if ((*new_start)[0] == ' ') {
 516                         (*new_start)++;
 517                 }
 518         }
 519
 520 skip_ts:
 521         /*
 522          * At this point, we know if the stream class's event header
 523          * field class should have a timestamp or not, so we can lazily
 524          * create the metadata and stream objects.
 525          */
 526         ret = try_create_meta_stream(dmesg_comp, has_timestamp);
 527         if (ret) {
 528                 /* try_create_meta_stream() logs errors */
 529                 goto error;
 530         }
 531
 532         if (dmesg_comp->clock_class) {
 533                 msg = bt_message_event_create_with_default_clock_snapshot(
 534                         msg_iter->pc_msg_iter,
 535                         dmesg_comp->event_class, dmesg_comp->stream, ts);
 536                 msg_iter->last_clock_value = ts;
 537         } else {
 538                 msg = bt_message_event_create(msg_iter->pc_msg_iter,
 539                         dmesg_comp->event_class, dmesg_comp->stream);
 540         }
 541
 542         if (!msg) {
 543                 BT_COMP_LOGE_STR("Cannot create event message.");
 544                 goto error;
 545         }
 546
 547         event = bt_message_event_borrow_event(msg);
 548         BT_ASSERT(event);
 549         goto end;
 550
 551 error:
 552         BT_MESSAGE_PUT_REF_AND_RESET(msg);
 553
 554 end:
 555         return msg;
 556 }
 557
 558 static
 559 int fill_event_payload_from_line(struct dmesg_component *dmesg_comp,
 560                 const char *line, bt_event *event)
 561 {
 562         bt_field *ep_field = NULL;
 563         bt_field *str_field = NULL;
 564         size_t len;
 565         int ret;
 566
 567         ep_field = bt_event_borrow_payload_field(event);
 568         BT_ASSERT(ep_field);
 569         str_field = bt_field_structure_borrow_member_field_by_index(
 570                 ep_field, 0);
 571         if (!str_field) {
 572                 BT_COMP_LOGE_STR("Cannot borrow `timestamp` field from event payload structure field.");
 573                 goto error;
 574         }
 575
 576         len = strlen(line);
 577         if (line[len - 1] == '\n') {
 578                 /* Do not include the newline character in the payload */
 579                 len--;
 580         }
 581
 582         bt_field_string_clear(str_field);
 583         ret = bt_field_string_append_with_length(str_field, line, len);
 584         if (ret) {
 585                 BT_COMP_LOGE("Cannot append value to string field object: "
 586                         "len=%zu", len);
 587                 goto error;
 588         }
 589
 590         goto end;
 591
 592 error:
 593         ret = -1;
 594
 595 end:
 596         return ret;
 597 }
 598
 599 static
 600 bt_message *create_msg_from_line(
 601                 struct dmesg_msg_iter *dmesg_msg_iter, const char *line)
 602 {
 603         struct dmesg_component *dmesg_comp = dmesg_msg_iter->dmesg_comp;
 604         bt_event *event = NULL;
 605         bt_message *msg = NULL;
 606         const char *new_start;
 607         int ret;
 608
 609         msg = create_init_event_msg_from_line(dmesg_msg_iter,
 610                 line, &new_start);
 611         if (!msg) {
 612                 BT_COMP_LOGE_STR("Cannot create and initialize event message from line.");
 613                 goto error;
 614         }
 615
 616         event = bt_message_event_borrow_event(msg);
 617         BT_ASSERT(event);
 618         ret = fill_event_payload_from_line(dmesg_comp, new_start, event);
 619         if (ret) {
 620                 BT_COMP_LOGE("Cannot fill event payload field from line: "
 621                         "ret=%d", ret);
 622                 goto error;
 623         }
 624
 625         goto end;
 626
 627 error:
 628         BT_MESSAGE_PUT_REF_AND_RESET(msg);
 629
 630 end:
 631         return msg;
 632 }
 633
 634 static
 635 void destroy_dmesg_msg_iter(struct dmesg_msg_iter *dmesg_msg_iter)
 636 {
 637         struct dmesg_component *dmesg_comp = dmesg_msg_iter->dmesg_comp;
 638
 639         if (!dmesg_msg_iter) {
 640                 return;
 641         }
 642
 643         if (dmesg_msg_iter->fp && dmesg_msg_iter->fp != stdin) {
 644                 if (fclose(dmesg_msg_iter->fp)) {
 645                         BT_COMP_LOGE_ERRNO("Cannot close input file", ".");
 646                 }
 647         }
 648
 649         bt_message_put_ref(dmesg_msg_iter->tmp_event_msg);
 650         free(dmesg_msg_iter->linebuf);
 651         g_free(dmesg_msg_iter);
 652 }
 653
 654
 655
 656 BT_HIDDEN
 657 bt_component_class_message_iterator_init_method_status dmesg_msg_iter_init(
 658                 bt_self_message_iterator *self_msg_iter,
 659                 bt_self_component_source *self_comp,
 660                 bt_self_component_port_output *self_port)
 661 {
 662         struct dmesg_component *dmesg_comp = bt_self_component_get_data(
 663                 bt_self_component_source_as_self_component(self_comp));
 664         struct dmesg_msg_iter *dmesg_msg_iter =
 665                 g_new0(struct dmesg_msg_iter, 1);
 666         bt_component_class_message_iterator_init_method_status status =
 667                 BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INIT_METHOD_STATUS_OK;
 668
 669         if (!dmesg_msg_iter) {
 670                 BT_COMP_LOGE_STR("Failed to allocate on dmesg message iterator structure.");
 671                 goto error;
 672         }
 673
 674         BT_ASSERT(dmesg_comp);
 675         dmesg_msg_iter->dmesg_comp = dmesg_comp;
 676         dmesg_msg_iter->pc_msg_iter = self_msg_iter;
 677
 678         if (dmesg_comp->params.read_from_stdin) {
 679                 dmesg_msg_iter->fp = stdin;
 680         } else {
 681                 dmesg_msg_iter->fp = fopen(dmesg_comp->params.path->str, "r");
 682                 if (!dmesg_msg_iter->fp) {
 683                         BT_COMP_LOGE_ERRNO("Cannot open input file in read mode", ": path=\"%s\"",
 684                                 dmesg_comp->params.path->str);
 685                         goto error;
 686                 }
 687         }
 688
 689         bt_self_message_iterator_set_data(self_msg_iter,
 690                 dmesg_msg_iter);
 691         goto end;
 692
 693 error:
 694         destroy_dmesg_msg_iter(dmesg_msg_iter);
 695         bt_self_message_iterator_set_data(self_msg_iter, NULL);
 696         if (status >= 0) {
 697                 status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INIT_METHOD_STATUS_ERROR;
 698         }
 699
 700 end:
 701         return status;
 702 }
 703
 704 BT_HIDDEN
 705 void dmesg_msg_iter_finalize(
 706                 bt_self_message_iterator *priv_msg_iter)
 707 {
 708         destroy_dmesg_msg_iter(bt_self_message_iterator_get_data(
 709                 priv_msg_iter));
 710 }
 711
 712 static
 713 bt_component_class_message_iterator_next_method_status dmesg_msg_iter_next_one(
 714                 struct dmesg_msg_iter *dmesg_msg_iter,
 715                 bt_message **msg)
 716 {
 717         ssize_t len;
 718         struct dmesg_component *dmesg_comp;
 719         bt_component_class_message_iterator_next_method_status status =
 720                 BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
 721
 722         BT_ASSERT(dmesg_msg_iter);
 723         dmesg_comp = dmesg_msg_iter->dmesg_comp;
 724         BT_ASSERT(dmesg_comp);
 725
 726         if (dmesg_msg_iter->state == STATE_DONE) {
 727                 status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_END;
 728                 goto end;
 729         }
 730
 731         if (dmesg_msg_iter->tmp_event_msg ||
 732                         dmesg_msg_iter->state == STATE_EMIT_STREAM_END) {
 733                 goto handle_state;
 734         }
 735
 736         while (true) {
 737                 const char *ch;
 738                 bool only_spaces = true;
 739
 740                 len = bt_getline(&dmesg_msg_iter->linebuf,
 741                         &dmesg_msg_iter->linebuf_len, dmesg_msg_iter->fp);
 742                 if (len < 0) {
 743                         if (errno == EINVAL) {
 744                                 status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
 745                         } else if (errno == ENOMEM) {
 746                                 status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_MEMORY_ERROR;
 747                         } else {
 748                                 if (dmesg_msg_iter->state == STATE_EMIT_STREAM_BEGINNING) {
 749                                         /* Stream did not even begin */
 750                                         status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_END;
 751                                         goto end;
 752                                 } else {
 753                                         /* End stream now */
 754                                         dmesg_msg_iter->state =
 755                                                 STATE_EMIT_STREAM_END;
 756                                         goto handle_state;
 757                                 }
 758                         }
 759
 760                         goto end;
 761                 }
 762
 763                 BT_ASSERT(dmesg_msg_iter->linebuf);
 764
 765                 /* Ignore empty lines, once trimmed */
 766                 for (ch = dmesg_msg_iter->linebuf; *ch != '\0'; ch++) {
 767                         if (!isspace(*ch)) {
 768                                 only_spaces = false;
 769                                 break;
 770                         }
 771                 }
 772
 773                 if (!only_spaces) {
 774                         break;
 775                 }
 776         }
 777
 778         dmesg_msg_iter->tmp_event_msg = create_msg_from_line(
 779                 dmesg_msg_iter, dmesg_msg_iter->linebuf);
 780         if (!dmesg_msg_iter->tmp_event_msg) {
 781                 BT_COMP_LOGE("Cannot create event message from line: "
 782                         "dmesg-comp-addr=%p, line=\"%s\"", dmesg_comp,
 783                         dmesg_msg_iter->linebuf);
 784                 goto end;
 785         }
 786
 787 handle_state:
 788         BT_ASSERT(dmesg_comp->trace);
 789
 790         switch (dmesg_msg_iter->state) {
 791         case STATE_EMIT_STREAM_BEGINNING:
 792                 BT_ASSERT(dmesg_msg_iter->tmp_event_msg);
 793                 *msg = bt_message_stream_beginning_create(
 794                         dmesg_msg_iter->pc_msg_iter, dmesg_comp->stream);
 795                 dmesg_msg_iter->state = STATE_EMIT_EVENT;
 796                 break;
 797         case STATE_EMIT_EVENT:
 798                 BT_ASSERT(dmesg_msg_iter->tmp_event_msg);
 799                 *msg = dmesg_msg_iter->tmp_event_msg;
 800                 dmesg_msg_iter->tmp_event_msg = NULL;
 801                 break;
 802         case STATE_EMIT_STREAM_END:
 803                 *msg = bt_message_stream_end_create(
 804                         dmesg_msg_iter->pc_msg_iter, dmesg_comp->stream);
 805                 dmesg_msg_iter->state = STATE_DONE;
 806                 break;
 807         default:
 808                 break;
 809         }
 810
 811         if (!*msg) {
 812                 BT_COMP_LOGE("Cannot create message: dmesg-comp-addr=%p",
 813                         dmesg_comp);
 814                 status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
 815         }
 816
 817 end:
 818         return status;
 819 }
 820
 821 BT_HIDDEN
 822 bt_component_class_message_iterator_next_method_status dmesg_msg_iter_next(
 823                 bt_self_message_iterator *self_msg_iter,
 824                 bt_message_array_const msgs, uint64_t capacity,
 825                 uint64_t *count)
 826 {
 827         struct dmesg_msg_iter *dmesg_msg_iter =
 828                 bt_self_message_iterator_get_data(
 829                         self_msg_iter);
 830         bt_component_class_message_iterator_next_method_status status =
 831                 BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
 832         uint64_t i = 0;
 833
 834         while (i < capacity &&
 835                         status == BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
 836                 bt_message *priv_msg = NULL;
 837
 838                 status = dmesg_msg_iter_next_one(dmesg_msg_iter,
 839                         &priv_msg);
 840                 msgs[i] = priv_msg;
 841                 if (status == BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
 842                         i++;
 843                 }
 844         }
 845
 846         if (i > 0) {
 847                 /*
 848                  * Even if dmesg_msg_iter_next_one() returned
 849                  * something else than
 850                  * BT_SELF_MESSAGE_ITERATOR_STATUS_OK, we
 851                  * accumulated message objects in the output
 852                  * message array, so we need to return
 853                  * BT_SELF_MESSAGE_ITERATOR_STATUS_OK so that they
 854                  * are transfered to downstream. This other status
 855                  * occurs again the next time muxer_msg_iter_do_next()
 856                  * is called, possibly without any accumulated
 857                  * message, in which case we'll return it.
 858                  */
 859                 *count = i;
 860                 status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
 861         }
 862
 863         return status;
 864 }
 865
 866 BT_HIDDEN
 867 bt_bool dmesg_msg_iter_can_seek_beginning(
 868                 bt_self_message_iterator *self_msg_iter)
 869 {
 870         struct dmesg_msg_iter *dmesg_msg_iter =
 871                 bt_self_message_iterator_get_data(self_msg_iter);
 872
 873         /* Can't seek the beginning of the standard input stream */
 874         return !dmesg_msg_iter->dmesg_comp->params.read_from_stdin;
 875 }
 876
 877 BT_HIDDEN
 878 bt_component_class_message_iterator_seek_beginning_method_status
 879 dmesg_msg_iter_seek_beginning(
 880                 bt_self_message_iterator *self_msg_iter)
 881 {
 882         struct dmesg_msg_iter *dmesg_msg_iter =
 883                 bt_self_message_iterator_get_data(self_msg_iter);
 884
 885         BT_ASSERT(!dmesg_msg_iter->dmesg_comp->params.read_from_stdin);
 886
 887         BT_MESSAGE_PUT_REF_AND_RESET(dmesg_msg_iter->tmp_event_msg);
 888         dmesg_msg_iter->last_clock_value = 0;
 889         dmesg_msg_iter->state = STATE_EMIT_STREAM_BEGINNING;
 890         return BT_COMPONENT_CLASS_MESSAGE_ITERATOR_SEEK_BEGINNING_METHOD_STATUS_OK;
 891 }