src/bin/lttng-relayd/main.c

   1 /*
   2  * Copyright (C) 2012 Julien Desfossez <jdesfossez@efficios.com>
   3  * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
   4  * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  *
   7  * SPDX-License-Identifier: GPL-2.0-only
   8  *
   9  */
  10
  11 #define _LGPL_SOURCE
  12 #include <getopt.h>
  13 #include <grp.h>
  14 #include <limits.h>
  15 #include <pthread.h>
  16 #include <signal.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <sys/mman.h>
  21 #include <sys/mount.h>
  22 #include <sys/resource.h>
  23 #include <sys/socket.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <sys/wait.h>
  27 #include <sys/resource.h>
  28 #include <inttypes.h>
  29 #include <urcu/futex.h>
  30 #include <urcu/uatomic.h>
  31 #include <urcu/rculist.h>
  32 #include <unistd.h>
  33 #include <fcntl.h>
  34 #include <strings.h>
  35 #include <ctype.h>
  36
  37 #include <lttng/lttng.h>
  38 #include <common/common.h>
  39 #include <common/compat/poll.h>
  40 #include <common/compat/socket.h>
  41 #include <common/compat/endian.h>
  42 #include <common/compat/getenv.h>
  43 #include <common/defaults.h>
  44 #include <common/daemonize.h>
  45 #include <common/futex.h>
  46 #include <common/sessiond-comm/sessiond-comm.h>
  47 #include <common/sessiond-comm/inet.h>
  48 #include <common/sessiond-comm/relayd.h>
  49 #include <common/uri.h>
  50 #include <common/utils.h>
  51 #include <common/align.h>
  52 #include <common/config/session-config.h>
  53 #include <common/dynamic-buffer.h>
  54 #include <common/buffer-view.h>
  55 #include <common/string-utils/format.h>
  56 #include <common/fd-tracker/fd-tracker.h>
  57 #include <common/fd-tracker/utils.h>
  58
  59 #include "backward-compatibility-group-by.h"
  60 #include "cmd.h"
  61 #include "connection.h"
  62 #include "ctf-trace.h"
  63 #include "health-relayd.h"
  64 #include "index.h"
  65 #include "live.h"
  66 #include "lttng-relayd.h"
  67 #include "session.h"
  68 #include "sessiond-trace-chunks.h"
  69 #include "stream.h"
  70 #include "tcp_keep_alive.h"
  71 #include "testpoint.h"
  72 #include "tracefile-array.h"
  73 #include "utils.h"
  74 #include "version.h"
  75 #include "viewer-stream.h"
  76
  77 static const char *help_msg =
  78 #ifdef LTTNG_EMBED_HELP
  79 #include <lttng-relayd.8.h>
  80 #else
  81 NULL
  82 #endif
  83 ;
  84
  85 enum relay_connection_status {
  86         RELAY_CONNECTION_STATUS_OK,
  87         /* An error occurred while processing an event on the connection. */
  88         RELAY_CONNECTION_STATUS_ERROR,
  89         /* Connection closed/shutdown cleanly. */
  90         RELAY_CONNECTION_STATUS_CLOSED,
  91 };
  92
  93 /* command line options */
  94 char *opt_output_path, *opt_working_directory;
  95 static int opt_daemon, opt_background, opt_print_version, opt_allow_clear = 1;
  96 enum relay_group_output_by opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_UNKNOWN;
  97
  98 /*
  99  * We need to wait for listener and live listener threads, as well as
 100  * health check thread, before being ready to signal readiness.
 101  */
 102 #define NR_LTTNG_RELAY_READY    3
 103 static int lttng_relay_ready = NR_LTTNG_RELAY_READY;
 104
 105 /* Size of receive buffer. */
 106 #define RECV_DATA_BUFFER_SIZE           65536
 107
 108 static int recv_child_signal;   /* Set to 1 when a SIGUSR1 signal is received. */
 109 static pid_t child_ppid;        /* Internal parent PID use with daemonize. */
 110
 111 static struct lttng_uri *control_uri;
 112 static struct lttng_uri *data_uri;
 113 static struct lttng_uri *live_uri;
 114
 115 const char *progname;
 116
 117 const char *tracing_group_name = DEFAULT_TRACING_GROUP;
 118 static int tracing_group_name_override;
 119
 120 const char * const config_section_name = "relayd";
 121
 122 /*
 123  * Quit pipe for all threads. This permits a single cancellation point
 124  * for all threads when receiving an event on the pipe.
 125  */
 126 int thread_quit_pipe[2] = { -1, -1 };
 127
 128 /*
 129  * This pipe is used to inform the worker thread that a command is queued and
 130  * ready to be processed.
 131  */
 132 static int relay_conn_pipe[2] = { -1, -1 };
 133
 134 /* Shared between threads */
 135 static int dispatch_thread_exit;
 136
 137 static pthread_t listener_thread;
 138 static pthread_t dispatcher_thread;
 139 static pthread_t worker_thread;
 140 static pthread_t health_thread;
 141
 142 /*
 143  * last_relay_stream_id_lock protects last_relay_stream_id increment
 144  * atomicity on 32-bit architectures.
 145  */
 146 static pthread_mutex_t last_relay_stream_id_lock = PTHREAD_MUTEX_INITIALIZER;
 147 static uint64_t last_relay_stream_id;
 148
 149 /*
 150  * Relay command queue.
 151  *
 152  * The relay_thread_listener and relay_thread_dispatcher communicate with this
 153  * queue.
 154  */
 155 static struct relay_conn_queue relay_conn_queue;
 156
 157 /* Cap of file desriptors to be in simultaneous use by the relay daemon. */
 158 static unsigned int lttng_opt_fd_pool_size = -1;
 159
 160 /* Global relay stream hash table. */
 161 struct lttng_ht *relay_streams_ht;
 162
 163 /* Global relay viewer stream hash table. */
 164 struct lttng_ht *viewer_streams_ht;
 165
 166 /* Global relay sessions hash table. */
 167 struct lttng_ht *sessions_ht;
 168
 169 /* Relayd health monitoring */
 170 struct health_app *health_relayd;
 171
 172 struct sessiond_trace_chunk_registry *sessiond_trace_chunk_registry;
 173
 174 /* Global fd tracker. */
 175 struct fd_tracker *the_fd_tracker;
 176
 177 static struct option long_options[] = {
 178         { "control-port", 1, 0, 'C', },
 179         { "data-port", 1, 0, 'D', },
 180         { "live-port", 1, 0, 'L', },
 181         { "daemonize", 0, 0, 'd', },
 182         { "background", 0, 0, 'b', },
 183         { "group", 1, 0, 'g', },
 184         { "fd-pool-size", 1, 0, '\0', },
 185         { "help", 0, 0, 'h', },
 186         { "output", 1, 0, 'o', },
 187         { "verbose", 0, 0, 'v', },
 188         { "config", 1, 0, 'f' },
 189         { "version", 0, 0, 'V' },
 190         { "working-directory", 1, 0, 'w', },
 191         { "group-output-by-session", 0, 0, 's', },
 192         { "group-output-by-host", 0, 0, 'p', },
 193         { "disallow-clear", 0, 0, 'x' },
 194         { NULL, 0, 0, 0, },
 195 };
 196
 197 static const char *config_ignore_options[] = { "help", "config", "version" };
 198
 199 static void print_version(void) {
 200         fprintf(stdout, "%s\n", VERSION);
 201 }
 202
 203 static void relayd_config_log(void)
 204 {
 205         DBG("LTTng-relayd " VERSION " - " VERSION_NAME "%s%s",
 206                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION,
 207                         EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " EXTRA_VERSION_NAME);
 208         if (EXTRA_VERSION_DESCRIPTION[0] != '\0') {
 209                 DBG("LTTng-relayd extra version description:\n\t" EXTRA_VERSION_DESCRIPTION "\n");
 210         }
 211         if (EXTRA_VERSION_PATCHES[0] != '\0') {
 212                 DBG("LTTng-relayd extra patches:\n\t" EXTRA_VERSION_PATCHES "\n");
 213         }
 214 }
 215
 216 /*
 217  * Take an option from the getopt output and set it in the right variable to be
 218  * used later.
 219  *
 220  * Return 0 on success else a negative value.
 221  */
 222 static int set_option(int opt, const char *arg, const char *optname)
 223 {
 224         int ret;
 225
 226         switch (opt) {
 227         case 0:
 228                 if (!strcmp(optname, "fd-pool-size")) {
 229                         unsigned long v;
 230
 231                         errno = 0;
 232                         v = strtoul(arg, NULL, 0);
 233                         if (errno != 0 || !isdigit((unsigned char) arg[0])) {
 234                                 ERR("Wrong value in --fd-pool-size parameter: %s", arg);
 235                                 ret = -1;
 236                                 goto end;
 237                         }
 238                         if (v >= UINT_MAX) {
 239                                 ERR("File descriptor cap overflow in --fd-pool-size parameter: %s", arg);
 240                                 ret = -1;
 241                                 goto end;
 242                         }
 243                         lttng_opt_fd_pool_size = (unsigned int) v;
 244                 } else {
 245                         fprintf(stderr, "unknown option %s", optname);
 246                         if (arg) {
 247                                 fprintf(stderr, " with arg %s\n", arg);
 248                         }
 249                 }
 250                 break;
 251         case 'C':
 252                 if (lttng_is_setuid_setgid()) {
 253                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 254                                 "-C, --control-port");
 255                 } else {
 256                         ret = uri_parse(arg, &control_uri);
 257                         if (ret < 0) {
 258                                 ERR("Invalid control URI specified");
 259                                 goto end;
 260                         }
 261                         if (control_uri->port == 0) {
 262                                 control_uri->port = DEFAULT_NETWORK_CONTROL_PORT;
 263                         }
 264                 }
 265                 break;
 266         case 'D':
 267                 if (lttng_is_setuid_setgid()) {
 268                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 269                                 "-D, -data-port");
 270                 } else {
 271                         ret = uri_parse(arg, &data_uri);
 272                         if (ret < 0) {
 273                                 ERR("Invalid data URI specified");
 274                                 goto end;
 275                         }
 276                         if (data_uri->port == 0) {
 277                                 data_uri->port = DEFAULT_NETWORK_DATA_PORT;
 278                         }
 279                 }
 280                 break;
 281         case 'L':
 282                 if (lttng_is_setuid_setgid()) {
 283                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 284                                 "-L, -live-port");
 285                 } else {
 286                         ret = uri_parse(arg, &live_uri);
 287                         if (ret < 0) {
 288                                 ERR("Invalid live URI specified");
 289                                 goto end;
 290                         }
 291                         if (live_uri->port == 0) {
 292                                 live_uri->port = DEFAULT_NETWORK_VIEWER_PORT;
 293                         }
 294                 }
 295                 break;
 296         case 'd':
 297                 opt_daemon = 1;
 298                 break;
 299         case 'b':
 300                 opt_background = 1;
 301                 break;
 302         case 'g':
 303                 if (lttng_is_setuid_setgid()) {
 304                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 305                                 "-g, --group");
 306                 } else {
 307                         tracing_group_name = strdup(arg);
 308                         if (tracing_group_name == NULL) {
 309                                 ret = -errno;
 310                                 PERROR("strdup");
 311                                 goto end;
 312                         }
 313                         tracing_group_name_override = 1;
 314                 }
 315                 break;
 316         case 'h':
 317                 ret = utils_show_help(8, "lttng-relayd", help_msg);
 318                 if (ret) {
 319                         ERR("Cannot show --help for `lttng-relayd`");
 320                         perror("exec");
 321                 }
 322                 exit(EXIT_FAILURE);
 323         case 'V':
 324                 opt_print_version = 1;
 325                 break;
 326         case 'o':
 327                 if (lttng_is_setuid_setgid()) {
 328                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 329                                 "-o, --output");
 330                 } else {
 331                         ret = asprintf(&opt_output_path, "%s", arg);
 332                         if (ret < 0) {
 333                                 ret = -errno;
 334                                 PERROR("asprintf opt_output_path");
 335                                 goto end;
 336                         }
 337                 }
 338                 break;
 339         case 'w':
 340                 if (lttng_is_setuid_setgid()) {
 341                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 342                                 "-w, --working-directory");
 343                 } else {
 344                         ret = asprintf(&opt_working_directory, "%s", arg);
 345                         if (ret < 0) {
 346                                 ret = -errno;
 347                                 PERROR("asprintf opt_working_directory");
 348                                 goto end;
 349                         }
 350                 }
 351                 break;
 352
 353         case 'v':
 354                 /* Verbose level can increase using multiple -v */
 355                 if (arg) {
 356                         lttng_opt_verbose = config_parse_value(arg);
 357                 } else {
 358                         /* Only 3 level of verbosity (-vvv). */
 359                         if (lttng_opt_verbose < 3) {
 360                                 lttng_opt_verbose += 1;
 361                         }
 362                 }
 363                 break;
 364         case 's':
 365                 if (opt_group_output_by != RELAYD_GROUP_OUTPUT_BY_UNKNOWN) {
 366                         ERR("Cannot set --group-output-by-session, another --group-output-by argument is present");
 367                         exit(EXIT_FAILURE);
 368                 }
 369                 opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_SESSION;
 370                 break;
 371         case 'p':
 372                 if (opt_group_output_by != RELAYD_GROUP_OUTPUT_BY_UNKNOWN) {
 373                         ERR("Cannot set --group-output-by-host, another --group-output-by argument is present");
 374                         exit(EXIT_FAILURE);
 375                 }
 376                 opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_HOST;
 377                 break;
 378         case 'x':
 379                 /* Disallow clear */
 380                 opt_allow_clear = 0;
 381                 break;
 382         default:
 383                 /* Unknown option or other error.
 384                  * Error is printed by getopt, just return */
 385                 ret = -1;
 386                 goto end;
 387         }
 388
 389         /* All good. */
 390         ret = 0;
 391
 392 end:
 393         return ret;
 394 }
 395
 396 /*
 397  * config_entry_handler_cb used to handle options read from a config file.
 398  * See config_entry_handler_cb comment in common/config/session-config.h for the
 399  * return value conventions.
 400  */
 401 static int config_entry_handler(const struct config_entry *entry, void *unused)
 402 {
 403         int ret = 0, i;
 404
 405         if (!entry || !entry->name || !entry->value) {
 406                 ret = -EINVAL;
 407                 goto end;
 408         }
 409
 410         /* Check if the option is to be ignored */
 411         for (i = 0; i < sizeof(config_ignore_options) / sizeof(char *); i++) {
 412                 if (!strcmp(entry->name, config_ignore_options[i])) {
 413                         goto end;
 414                 }
 415         }
 416
 417         for (i = 0; i < (sizeof(long_options) / sizeof(struct option)) - 1; i++) {
 418                 /* Ignore if entry name is not fully matched. */
 419                 if (strcmp(entry->name, long_options[i].name)) {
 420                         continue;
 421                 }
 422
 423                 /*
 424                  * If the option takes no argument on the command line,
 425                  * we have to check if the value is "true". We support
 426                  * non-zero numeric values, true, on and yes.
 427                  */
 428                 if (!long_options[i].has_arg) {
 429                         ret = config_parse_value(entry->value);
 430                         if (ret <= 0) {
 431                                 if (ret) {
 432                                         WARN("Invalid configuration value \"%s\" for option %s",
 433                                                         entry->value, entry->name);
 434                                 }
 435                                 /* False, skip boolean config option. */
 436                                 goto end;
 437                         }
 438                 }
 439
 440                 ret = set_option(long_options[i].val, entry->value, entry->name);
 441                 goto end;
 442         }
 443
 444         WARN("Unrecognized option \"%s\" in daemon configuration file.",
 445                         entry->name);
 446
 447 end:
 448         return ret;
 449 }
 450
 451 static int parse_env_options(void)
 452 {
 453         int ret = 0;
 454         char *value = NULL;
 455
 456         value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_WORKING_DIRECTORY_ENV);
 457         if (value) {
 458                 opt_working_directory = strdup(value);
 459                 if (!opt_working_directory) {
 460                         ERR("Failed to allocate working directory string (\"%s\")",
 461                                         value);
 462                         ret = -1;
 463                 }
 464         }
 465         return ret;
 466 }
 467
 468 static int set_fd_pool_size(void)
 469 {
 470         int ret = 0;
 471         struct rlimit rlimit;
 472
 473         ret = getrlimit(RLIMIT_NOFILE, &rlimit);
 474         if (ret) {
 475                 PERROR("Failed to get file descriptor limit");
 476                 ret = -1;
 477                 goto end;
 478         }
 479
 480         DBG("File descriptor count limits are %" PRIu64 " (soft) and %" PRIu64 " (hard)",
 481                         (uint64_t) rlimit.rlim_cur,
 482                         (uint64_t) rlimit.rlim_max);
 483         if (lttng_opt_fd_pool_size == -1) {
 484                 /* Use default value (soft limit - reserve). */
 485                 if (rlimit.rlim_cur < DEFAULT_RELAYD_MIN_FD_POOL_SIZE) {
 486                         ERR("The process' file number limit is too low (%" PRIu64 "). The process' file number limit must be set to at least %i.",
 487                                         (uint64_t) rlimit.rlim_cur, DEFAULT_RELAYD_MIN_FD_POOL_SIZE);
 488                         ret = -1;
 489                         goto end;
 490                 }
 491                 lttng_opt_fd_pool_size = rlimit.rlim_cur -
 492                                 DEFAULT_RELAYD_FD_POOL_SIZE_RESERVE;
 493                 goto end;
 494         }
 495
 496         if (lttng_opt_fd_pool_size < DEFAULT_RELAYD_MIN_FD_POOL_SIZE) {
 497                 ERR("File descriptor pool size must be set to at least %d",
 498                                 DEFAULT_RELAYD_MIN_FD_POOL_SIZE);
 499                 ret = -1;
 500                 goto end;
 501         }
 502
 503         if (lttng_opt_fd_pool_size > rlimit.rlim_cur) {
 504                 ERR("File descriptor pool size argument (%u) exceeds the process' soft limit (%" PRIu64 ").",
 505                                 lttng_opt_fd_pool_size, (uint64_t) rlimit.rlim_cur);
 506                 ret = -1;
 507                 goto end;
 508         }
 509
 510         DBG("File descriptor pool size argument (%u) adjusted to %u to accommodates transient fd uses",
 511                         lttng_opt_fd_pool_size,
 512                         lttng_opt_fd_pool_size - DEFAULT_RELAYD_FD_POOL_SIZE_RESERVE);
 513         lttng_opt_fd_pool_size -= DEFAULT_RELAYD_FD_POOL_SIZE_RESERVE;
 514 end:
 515         return ret;
 516 }
 517
 518 static int set_options(int argc, char **argv)
 519 {
 520         int c, ret = 0, option_index = 0, retval = 0;
 521         int orig_optopt = optopt, orig_optind = optind;
 522         char *default_address, *optstring;
 523         char *config_path = NULL;
 524
 525         optstring = utils_generate_optstring(long_options,
 526                         sizeof(long_options) / sizeof(struct option));
 527         if (!optstring) {
 528                 retval = -ENOMEM;
 529                 goto exit;
 530         }
 531
 532         /* Check for the --config option */
 533
 534         while ((c = getopt_long(argc, argv, optstring, long_options,
 535                                         &option_index)) != -1) {
 536                 if (c == '?') {
 537                         retval = -EINVAL;
 538                         goto exit;
 539                 } else if (c != 'f') {
 540                         continue;
 541                 }
 542
 543                 if (lttng_is_setuid_setgid()) {
 544                         WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 545                                 "-f, --config");
 546                 } else {
 547                         free(config_path);
 548                         config_path = utils_expand_path(optarg);
 549                         if (!config_path) {
 550                                 ERR("Failed to resolve path: %s", optarg);
 551                         }
 552                 }
 553         }
 554
 555         ret = config_get_section_entries(config_path, config_section_name,
 556                         config_entry_handler, NULL);
 557         if (ret) {
 558                 if (ret > 0) {
 559                         ERR("Invalid configuration option at line %i", ret);
 560                 }
 561                 retval = -1;
 562                 goto exit;
 563         }
 564
 565         /* Reset getopt's global state */
 566         optopt = orig_optopt;
 567         optind = orig_optind;
 568         while (1) {
 569                 c = getopt_long(argc, argv, optstring, long_options, &option_index);
 570                 if (c == -1) {
 571                         break;
 572                 }
 573
 574                 ret = set_option(c, optarg, long_options[option_index].name);
 575                 if (ret < 0) {
 576                         retval = -1;
 577                         goto exit;
 578                 }
 579         }
 580
 581         /* assign default values */
 582         if (control_uri == NULL) {
 583                 ret = asprintf(&default_address,
 584                         "tcp://" DEFAULT_NETWORK_CONTROL_BIND_ADDRESS ":%d",
 585                         DEFAULT_NETWORK_CONTROL_PORT);
 586                 if (ret < 0) {
 587                         PERROR("asprintf default data address");
 588                         retval = -1;
 589                         goto exit;
 590                 }
 591
 592                 ret = uri_parse(default_address, &control_uri);
 593                 free(default_address);
 594                 if (ret < 0) {
 595                         ERR("Invalid control URI specified");
 596                         retval = -1;
 597                         goto exit;
 598                 }
 599         }
 600         if (data_uri == NULL) {
 601                 ret = asprintf(&default_address,
 602                         "tcp://" DEFAULT_NETWORK_DATA_BIND_ADDRESS ":%d",
 603                         DEFAULT_NETWORK_DATA_PORT);
 604                 if (ret < 0) {
 605                         PERROR("asprintf default data address");
 606                         retval = -1;
 607                         goto exit;
 608                 }
 609
 610                 ret = uri_parse(default_address, &data_uri);
 611                 free(default_address);
 612                 if (ret < 0) {
 613                         ERR("Invalid data URI specified");
 614                         retval = -1;
 615                         goto exit;
 616                 }
 617         }
 618         if (live_uri == NULL) {
 619                 ret = asprintf(&default_address,
 620                         "tcp://" DEFAULT_NETWORK_VIEWER_BIND_ADDRESS ":%d",
 621                         DEFAULT_NETWORK_VIEWER_PORT);
 622                 if (ret < 0) {
 623                         PERROR("asprintf default viewer control address");
 624                         retval = -1;
 625                         goto exit;
 626                 }
 627
 628                 ret = uri_parse(default_address, &live_uri);
 629                 free(default_address);
 630                 if (ret < 0) {
 631                         ERR("Invalid viewer control URI specified");
 632                         retval = -1;
 633                         goto exit;
 634                 }
 635         }
 636         ret = set_fd_pool_size();
 637         if (ret) {
 638                 retval = -1;
 639                 goto exit;
 640         }
 641
 642         if (opt_group_output_by == RELAYD_GROUP_OUTPUT_BY_UNKNOWN) {
 643                 opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_HOST;
 644         }
 645         if (opt_allow_clear) {
 646                 /* Check if env variable exists. */
 647                 const char *value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_DISALLOW_CLEAR_ENV);
 648                 if (value) {
 649                         ret = config_parse_value(value);
 650                         if (ret < 0) {
 651                                 ERR("Invalid value for %s specified", DEFAULT_LTTNG_RELAYD_DISALLOW_CLEAR_ENV);
 652                                 retval = -1;
 653                                 goto exit;
 654                         }
 655                         opt_allow_clear = !ret;
 656                 }
 657         }
 658
 659 exit:
 660         free(config_path);
 661         free(optstring);
 662         return retval;
 663 }
 664
 665 static void print_global_objects(void)
 666 {
 667         print_viewer_streams();
 668         print_relay_streams();
 669         print_sessions();
 670 }
 671
 672 static int noop_close(void *data, int *fds)
 673 {
 674         return 0;
 675 }
 676
 677 static void untrack_stdio(void)
 678 {
 679         int fds[] = { fileno(stdout), fileno(stderr) };
 680
 681         /*
 682          * noop_close is used since we don't really want to close
 683          * the stdio output fds; we merely want to stop tracking them.
 684          */
 685         (void) fd_tracker_close_unsuspendable_fd(the_fd_tracker,
 686                         fds, 2, noop_close, NULL);
 687 }
 688
 689 /*
 690  * Cleanup the daemon
 691  */
 692 static void relayd_cleanup(void)
 693 {
 694         print_global_objects();
 695
 696         DBG("Cleaning up");
 697
 698         if (viewer_streams_ht)
 699                 lttng_ht_destroy(viewer_streams_ht);
 700         if (relay_streams_ht)
 701                 lttng_ht_destroy(relay_streams_ht);
 702         if (sessions_ht)
 703                 lttng_ht_destroy(sessions_ht);
 704
 705         free(opt_output_path);
 706         free(opt_working_directory);
 707
 708         if (health_relayd) {
 709                 health_app_destroy(health_relayd);
 710         }
 711         /* Close thread quit pipes */
 712         if (health_quit_pipe[0] != -1) {
 713                 (void) fd_tracker_util_pipe_close(
 714                                 the_fd_tracker, health_quit_pipe);
 715         }
 716         if (thread_quit_pipe[0] != -1) {
 717                 (void) fd_tracker_util_pipe_close(
 718                                 the_fd_tracker, thread_quit_pipe);
 719         }
 720         if (sessiond_trace_chunk_registry) {
 721                 sessiond_trace_chunk_registry_destroy(
 722                                 sessiond_trace_chunk_registry);
 723         }
 724         if (the_fd_tracker) {
 725                 untrack_stdio();
 726                 /*
 727                  * fd_tracker_destroy() will log the contents of the fd-tracker
 728                  * if a leak is detected.
 729                  */
 730                 fd_tracker_destroy(the_fd_tracker);
 731         }
 732
 733         uri_free(control_uri);
 734         uri_free(data_uri);
 735         /* Live URI is freed in the live thread. */
 736
 737         if (tracing_group_name_override) {
 738                 free((void *) tracing_group_name);
 739         }
 740 }
 741
 742 /*
 743  * Write to writable pipe used to notify a thread.
 744  */
 745 static int notify_thread_pipe(int wpipe)
 746 {
 747         ssize_t ret;
 748
 749         ret = lttng_write(wpipe, "!", 1);
 750         if (ret < 1) {
 751                 PERROR("write poll pipe");
 752                 goto end;
 753         }
 754         ret = 0;
 755 end:
 756         return ret;
 757 }
 758
 759 static int notify_health_quit_pipe(int *pipe)
 760 {
 761         ssize_t ret;
 762
 763         ret = lttng_write(pipe[1], "4", 1);
 764         if (ret < 1) {
 765                 PERROR("write relay health quit");
 766                 goto end;
 767         }
 768         ret = 0;
 769 end:
 770         return ret;
 771 }
 772
 773 /*
 774  * Stop all relayd and relayd-live threads.
 775  */
 776 int lttng_relay_stop_threads(void)
 777 {
 778         int retval = 0;
 779
 780         /* Stopping all threads */
 781         DBG("Terminating all threads");
 782         if (notify_thread_pipe(thread_quit_pipe[1])) {
 783                 ERR("write error on thread quit pipe");
 784                 retval = -1;
 785         }
 786
 787         if (notify_health_quit_pipe(health_quit_pipe)) {
 788                 ERR("write error on health quit pipe");
 789         }
 790
 791         /* Dispatch thread */
 792         CMM_STORE_SHARED(dispatch_thread_exit, 1);
 793         futex_nto1_wake(&relay_conn_queue.futex);
 794
 795         if (relayd_live_stop()) {
 796                 ERR("Error stopping live threads");
 797                 retval = -1;
 798         }
 799         return retval;
 800 }
 801
 802 /*
 803  * Signal handler for the daemon
 804  *
 805  * Simply stop all worker threads, leaving main() return gracefully after
 806  * joining all threads and calling cleanup().
 807  */
 808 static void sighandler(int sig)
 809 {
 810         switch (sig) {
 811         case SIGINT:
 812                 DBG("SIGINT caught");
 813                 if (lttng_relay_stop_threads()) {
 814                         ERR("Error stopping threads");
 815                 }
 816                 break;
 817         case SIGTERM:
 818                 DBG("SIGTERM caught");
 819                 if (lttng_relay_stop_threads()) {
 820                         ERR("Error stopping threads");
 821                 }
 822                 break;
 823         case SIGUSR1:
 824                 CMM_STORE_SHARED(recv_child_signal, 1);
 825                 break;
 826         default:
 827                 break;
 828         }
 829 }
 830
 831 /*
 832  * Setup signal handler for :
 833  *              SIGINT, SIGTERM, SIGPIPE
 834  */
 835 static int set_signal_handler(void)
 836 {
 837         int ret = 0;
 838         struct sigaction sa;
 839         sigset_t sigset;
 840
 841         if ((ret = sigemptyset(&sigset)) < 0) {
 842                 PERROR("sigemptyset");
 843                 return ret;
 844         }
 845
 846         sa.sa_mask = sigset;
 847         sa.sa_flags = 0;
 848
 849         sa.sa_handler = sighandler;
 850         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 851                 PERROR("sigaction");
 852                 return ret;
 853         }
 854
 855         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
 856                 PERROR("sigaction");
 857                 return ret;
 858         }
 859
 860         if ((ret = sigaction(SIGUSR1, &sa, NULL)) < 0) {
 861                 PERROR("sigaction");
 862                 return ret;
 863         }
 864
 865         sa.sa_handler = SIG_IGN;
 866         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 867                 PERROR("sigaction");
 868                 return ret;
 869         }
 870
 871         DBG("Signal handler set for SIGTERM, SIGUSR1, SIGPIPE and SIGINT");
 872
 873         return ret;
 874 }
 875
 876 void lttng_relay_notify_ready(void)
 877 {
 878         /* Notify the parent of the fork() process that we are ready. */
 879         if (opt_daemon || opt_background) {
 880                 if (uatomic_sub_return(&lttng_relay_ready, 1) == 0) {
 881                         kill(child_ppid, SIGUSR1);
 882                 }
 883         }
 884 }
 885
 886 /*
 887  * Init thread quit pipe.
 888  *
 889  * Return -1 on error or 0 if all pipes are created.
 890  */
 891 static int init_thread_quit_pipe(void)
 892 {
 893         return fd_tracker_util_pipe_open_cloexec(
 894                         the_fd_tracker, "Quit pipe", thread_quit_pipe);
 895 }
 896
 897 /*
 898  * Init health quit pipe.
 899  *
 900  * Return -1 on error or 0 if all pipes are created.
 901  */
 902 static int init_health_quit_pipe(void)
 903 {
 904         return fd_tracker_util_pipe_open_cloexec(the_fd_tracker,
 905                         "Health quit pipe", health_quit_pipe);
 906 }
 907
 908 /*
 909  * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
 910  */
 911 static int create_named_thread_poll_set(struct lttng_poll_event *events,
 912                 int size, const char *name)
 913 {
 914         int ret;
 915
 916         if (events == NULL || size == 0) {
 917                 ret = -1;
 918                 goto error;
 919         }
 920
 921         ret = fd_tracker_util_poll_create(the_fd_tracker,
 922                         name, events, 1, LTTNG_CLOEXEC);
 923         if (ret) {
 924                 PERROR("Failed to create \"%s\" poll file descriptor", name);
 925                 goto error;
 926         }
 927
 928         /* Add quit pipe */
 929         ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN | LPOLLERR);
 930         if (ret < 0) {
 931                 goto error;
 932         }
 933
 934         return 0;
 935
 936 error:
 937         return ret;
 938 }
 939
 940 /*
 941  * Check if the thread quit pipe was triggered.
 942  *
 943  * Return 1 if it was triggered else 0;
 944  */
 945 static int check_thread_quit_pipe(int fd, uint32_t events)
 946 {
 947         if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
 948                 return 1;
 949         }
 950
 951         return 0;
 952 }
 953
 954 static int create_sock(void *data, int *out_fd)
 955 {
 956         int ret;
 957         struct lttcomm_sock *sock = data;
 958
 959         ret = lttcomm_create_sock(sock);
 960         if (ret < 0) {
 961                 goto end;
 962         }
 963
 964         *out_fd = sock->fd;
 965 end:
 966         return ret;
 967 }
 968
 969 static int close_sock(void *data, int *in_fd)
 970 {
 971         struct lttcomm_sock *sock = data;
 972
 973         return sock->ops->close(sock);
 974 }
 975
 976 static int accept_sock(void *data, int *out_fd)
 977 {
 978         int ret = 0;
 979         /* Socks is an array of in_sock, out_sock. */
 980         struct lttcomm_sock **socks = data;
 981         struct lttcomm_sock *in_sock = socks[0];
 982
 983         socks[1] = in_sock->ops->accept(in_sock);
 984         if (!socks[1]) {
 985                 ret = -1;
 986                 goto end;
 987         }
 988         *out_fd = socks[1]->fd;
 989 end:
 990         return ret;
 991 }
 992
 993 /*
 994  * Create and init socket from uri.
 995  */
 996 static struct lttcomm_sock *relay_socket_create(struct lttng_uri *uri,
 997                 const char *name)
 998 {
 999         int ret, sock_fd;
1000         struct lttcomm_sock *sock = NULL;
1001         char uri_str[PATH_MAX];
1002         char *formated_name = NULL;
1003
1004         sock = lttcomm_alloc_sock_from_uri(uri);
1005         if (sock == NULL) {
1006                 ERR("Allocating socket");
1007                 goto error;
1008         }
1009
1010         /*
1011          * Don't fail to create the socket if the name can't be built as it is
1012          * only used for debugging purposes.
1013          */
1014         ret = uri_to_str_url(uri, uri_str, sizeof(uri_str));
1015         uri_str[sizeof(uri_str) - 1] = '\0';
1016         if (ret >= 0) {
1017                 ret = asprintf(&formated_name, "%s socket @ %s", name,
1018                                 uri_str);
1019                 if (ret < 0) {
1020                         formated_name = NULL;
1021                 }
1022         }
1023
1024         ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker, &sock_fd,
1025                         (const char **) (formated_name ? &formated_name : NULL),
1026                         1, create_sock, sock);
1027         if (ret) {
1028                 PERROR("Failed to open \"%s\" relay socket",
1029                                 formated_name ?: "Unknown");
1030                 goto error;
1031         }
1032         DBG("Listening on %s socket %d", name, sock->fd);
1033
1034         ret = sock->ops->bind(sock);
1035         if (ret < 0) {
1036                 PERROR("Failed to bind socket");
1037                 goto error;
1038         }
1039
1040         ret = sock->ops->listen(sock, -1);
1041         if (ret < 0) {
1042                 goto error;
1043
1044         }
1045
1046         free(formated_name);
1047         return sock;
1048
1049 error:
1050         if (sock) {
1051                 lttcomm_destroy_sock(sock);
1052         }
1053         free(formated_name);
1054         return NULL;
1055 }
1056
1057 static
1058 struct lttcomm_sock *accept_relayd_sock(struct lttcomm_sock *listening_sock,
1059                 const char *name)
1060 {
1061         int out_fd, ret;
1062         struct lttcomm_sock *socks[2] = { listening_sock, NULL };
1063         struct lttcomm_sock *new_sock = NULL;
1064
1065         ret = fd_tracker_open_unsuspendable_fd(
1066                         the_fd_tracker, &out_fd,
1067                         (const char **) &name,
1068                         1, accept_sock, &socks);
1069         if (ret) {
1070                 goto end;
1071         }
1072         new_sock = socks[1];
1073         DBG("%s accepted, socket %d", name, new_sock->fd);
1074 end:
1075         return new_sock;
1076 }
1077
1078 /*
1079  * This thread manages the listening for new connections on the network
1080  */
1081 static void *relay_thread_listener(void *data)
1082 {
1083         int i, ret, pollfd, err = -1;
1084         uint32_t revents, nb_fd;
1085         struct lttng_poll_event events;
1086         struct lttcomm_sock *control_sock, *data_sock;
1087
1088         DBG("[thread] Relay listener started");
1089
1090         rcu_register_thread();
1091         health_register(health_relayd, HEALTH_RELAYD_TYPE_LISTENER);
1092
1093         health_code_update();
1094
1095         control_sock = relay_socket_create(control_uri, "Control listener");
1096         if (!control_sock) {
1097                 goto error_sock_control;
1098         }
1099
1100         data_sock = relay_socket_create(data_uri, "Data listener");
1101         if (!data_sock) {
1102                 goto error_sock_relay;
1103         }
1104
1105         /*
1106          * Pass 3 as size here for the thread quit pipe, control and
1107          * data socket.
1108          */
1109         ret = create_named_thread_poll_set(&events, 3, "Listener thread epoll");
1110         if (ret < 0) {
1111                 goto error_create_poll;
1112         }
1113
1114         /* Add the control socket */
1115         ret = lttng_poll_add(&events, control_sock->fd, LPOLLIN | LPOLLRDHUP);
1116         if (ret < 0) {
1117                 goto error_poll_add;
1118         }
1119
1120         /* Add the data socket */
1121         ret = lttng_poll_add(&events, data_sock->fd, LPOLLIN | LPOLLRDHUP);
1122         if (ret < 0) {
1123                 goto error_poll_add;
1124         }
1125
1126         lttng_relay_notify_ready();
1127
1128         if (testpoint(relayd_thread_listener)) {
1129                 goto error_testpoint;
1130         }
1131
1132         while (1) {
1133                 health_code_update();
1134
1135                 DBG("Listener accepting connections");
1136
1137 restart:
1138                 health_poll_entry();
1139                 ret = lttng_poll_wait(&events, -1);
1140                 health_poll_exit();
1141                 if (ret < 0) {
1142                         /*
1143                          * Restart interrupted system call.
1144                          */
1145                         if (errno == EINTR) {
1146                                 goto restart;
1147                         }
1148                         goto error;
1149                 }
1150
1151                 nb_fd = ret;
1152
1153                 DBG("Relay new connection received");
1154                 for (i = 0; i < nb_fd; i++) {
1155                         health_code_update();
1156
1157                         /* Fetch once the poll data */
1158                         revents = LTTNG_POLL_GETEV(&events, i);
1159                         pollfd = LTTNG_POLL_GETFD(&events, i);
1160
1161                         /* Thread quit pipe has been closed. Killing thread. */
1162                         ret = check_thread_quit_pipe(pollfd, revents);
1163                         if (ret) {
1164                                 err = 0;
1165                                 goto exit;
1166                         }
1167
1168                         if (revents & LPOLLIN) {
1169                                 /*
1170                                  * A new connection is requested, therefore a
1171                                  * sessiond/consumerd connection is allocated in
1172                                  * this thread, enqueued to a global queue and
1173                                  * dequeued (and freed) in the worker thread.
1174                                  */
1175                                 int val = 1;
1176                                 struct relay_connection *new_conn;
1177                                 struct lttcomm_sock *newsock = NULL;
1178                                 enum connection_type type;
1179
1180                                 if (pollfd == data_sock->fd) {
1181                                         type = RELAY_DATA;
1182                                         newsock = accept_relayd_sock(data_sock,
1183                                                         "Data socket to relayd");
1184                                 } else {
1185                                         LTTNG_ASSERT(pollfd == control_sock->fd);
1186                                         type = RELAY_CONTROL;
1187                                         newsock = accept_relayd_sock(control_sock,
1188                                                         "Control socket to relayd");
1189                                 }
1190                                 if (!newsock) {
1191                                         PERROR("accepting sock");
1192                                         goto error;
1193                                 }
1194
1195                                 ret = setsockopt(newsock->fd, SOL_SOCKET, SO_REUSEADDR, &val,
1196                                                 sizeof(val));
1197                                 if (ret < 0) {
1198                                         PERROR("setsockopt inet");
1199                                         lttcomm_destroy_sock(newsock);
1200                                         goto error;
1201                                 }
1202
1203                                 ret = socket_apply_keep_alive_config(newsock->fd);
1204                                 if (ret < 0) {
1205                                         ERR("Failed to apply TCP keep-alive configuration on socket (%i)",
1206                                                         newsock->fd);
1207                                         lttcomm_destroy_sock(newsock);
1208                                         goto error;
1209                                 }
1210
1211                                 new_conn = connection_create(newsock, type);
1212                                 if (!new_conn) {
1213                                         lttcomm_destroy_sock(newsock);
1214                                         goto error;
1215                                 }
1216
1217                                 /* Enqueue request for the dispatcher thread. */
1218                                 cds_wfcq_enqueue(&relay_conn_queue.head, &relay_conn_queue.tail,
1219                                                  &new_conn->qnode);
1220
1221                                 /*
1222                                  * Wake the dispatch queue futex.
1223                                  * Implicit memory barrier with the
1224                                  * exchange in cds_wfcq_enqueue.
1225                                  */
1226                                 futex_nto1_wake(&relay_conn_queue.futex);
1227                         } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1228                                 ERR("socket poll error");
1229                                 goto error;
1230                         } else {
1231                                 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
1232                                 goto error;
1233                         }
1234                 }
1235         }
1236
1237 exit:
1238 error:
1239 error_poll_add:
1240 error_testpoint:
1241         (void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
1242 error_create_poll:
1243         if (data_sock->fd >= 0) {
1244                 int data_sock_fd = data_sock->fd;
1245
1246                 ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker,
1247                                 &data_sock_fd, 1, close_sock,
1248                                 data_sock);
1249                 if (ret) {
1250                         PERROR("Failed to close the data listener socket file descriptor");
1251                 }
1252                 data_sock->fd = -1;
1253         }
1254         lttcomm_destroy_sock(data_sock);
1255 error_sock_relay:
1256         if (control_sock->fd >= 0) {
1257                 int control_sock_fd = control_sock->fd;
1258
1259                 ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker,
1260                                 &control_sock_fd, 1, close_sock,
1261                                 control_sock);
1262                 if (ret) {
1263                         PERROR("Failed to close the control listener socket file descriptor");
1264                 }
1265                 control_sock->fd = -1;
1266         }
1267         lttcomm_destroy_sock(control_sock);
1268 error_sock_control:
1269         if (err) {
1270                 health_error();
1271                 ERR("Health error occurred in %s", __func__);
1272         }
1273         health_unregister(health_relayd);
1274         rcu_unregister_thread();
1275         DBG("Relay listener thread cleanup complete");
1276         lttng_relay_stop_threads();
1277         return NULL;
1278 }
1279
1280 /*
1281  * This thread manages the dispatching of the requests to worker threads
1282  */
1283 static void *relay_thread_dispatcher(void *data)
1284 {
1285         int err = -1;
1286         ssize_t ret;
1287         struct cds_wfcq_node *node;
1288         struct relay_connection *new_conn = NULL;
1289
1290         DBG("[thread] Relay dispatcher started");
1291
1292         health_register(health_relayd, HEALTH_RELAYD_TYPE_DISPATCHER);
1293
1294         if (testpoint(relayd_thread_dispatcher)) {
1295                 goto error_testpoint;
1296         }
1297
1298         health_code_update();
1299
1300         for (;;) {
1301                 health_code_update();
1302
1303                 /* Atomically prepare the queue futex */
1304                 futex_nto1_prepare(&relay_conn_queue.futex);
1305
1306                 if (CMM_LOAD_SHARED(dispatch_thread_exit)) {
1307                         break;
1308                 }
1309
1310                 do {
1311                         health_code_update();
1312
1313                         /* Dequeue commands */
1314                         node = cds_wfcq_dequeue_blocking(&relay_conn_queue.head,
1315                                                          &relay_conn_queue.tail);
1316                         if (node == NULL) {
1317                                 DBG("Woken up but nothing in the relay command queue");
1318                                 /* Continue thread execution */
1319                                 break;
1320                         }
1321                         new_conn = caa_container_of(node, struct relay_connection, qnode);
1322
1323                         DBG("Dispatching request waiting on sock %d", new_conn->sock->fd);
1324
1325                         /*
1326                          * Inform worker thread of the new request. This
1327                          * call is blocking so we can be assured that
1328                          * the data will be read at some point in time
1329                          * or wait to the end of the world :)
1330                          */
1331                         ret = lttng_write(relay_conn_pipe[1], &new_conn, sizeof(new_conn));
1332                         if (ret < 0) {
1333                                 PERROR("write connection pipe");
1334                                 connection_put(new_conn);
1335                                 goto error;
1336                         }
1337                 } while (node != NULL);
1338
1339                 /* Futex wait on queue. Blocking call on futex() */
1340                 health_poll_entry();
1341                 futex_nto1_wait(&relay_conn_queue.futex);
1342                 health_poll_exit();
1343         }
1344
1345         /* Normal exit, no error */
1346         err = 0;
1347
1348 error:
1349 error_testpoint:
1350         if (err) {
1351                 health_error();
1352                 ERR("Health error occurred in %s", __func__);
1353         }
1354         health_unregister(health_relayd);
1355         DBG("Dispatch thread dying");
1356         lttng_relay_stop_threads();
1357         return NULL;
1358 }
1359
1360 static bool session_streams_have_index(const struct relay_session *session)
1361 {
1362         return session->minor >= 4 && !session->snapshot;
1363 }
1364
1365 /*
1366  * Handle the RELAYD_CREATE_SESSION command.
1367  *
1368  * On success, send back the session id or else return a negative value.
1369  */
1370 static int relay_create_session(const struct lttcomm_relayd_hdr *recv_hdr,
1371                 struct relay_connection *conn,
1372                 const struct lttng_buffer_view *payload)
1373 {
1374         int ret = 0;
1375         ssize_t send_ret;
1376         struct relay_session *session = NULL;
1377         struct lttcomm_relayd_create_session_reply_2_11 reply = {};
1378         char session_name[LTTNG_NAME_MAX] = {};
1379         char hostname[LTTNG_HOST_NAME_MAX] = {};
1380         uint32_t live_timer = 0;
1381         bool snapshot = false;
1382         bool session_name_contains_creation_timestamp = false;
1383         /* Left nil for peers < 2.11. */
1384         char base_path[LTTNG_PATH_MAX] = {};
1385         lttng_uuid sessiond_uuid = {};
1386         LTTNG_OPTIONAL(uint64_t) id_sessiond = {};
1387         LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1388         LTTNG_OPTIONAL(time_t) creation_time = {};
1389         struct lttng_dynamic_buffer reply_payload;
1390
1391         lttng_dynamic_buffer_init(&reply_payload);
1392
1393         if (conn->minor < 4) {
1394                 /* From 2.1 to 2.3 */
1395                 ret = 0;
1396         } else if (conn->minor >= 4 && conn->minor < 11) {
1397                 /* From 2.4 to 2.10 */
1398                 ret = cmd_create_session_2_4(payload, session_name,
1399                         hostname, &live_timer, &snapshot);
1400         } else {
1401                 bool has_current_chunk;
1402                 uint64_t current_chunk_id_value;
1403                 time_t creation_time_value;
1404                 uint64_t id_sessiond_value;
1405
1406                 /* From 2.11 to ... */
1407                 ret = cmd_create_session_2_11(payload, session_name, hostname,
1408                                 base_path, &live_timer, &snapshot, &id_sessiond_value,
1409                                 sessiond_uuid, &has_current_chunk,
1410                                 &current_chunk_id_value, &creation_time_value,
1411                                 &session_name_contains_creation_timestamp);
1412                 if (lttng_uuid_is_nil(sessiond_uuid)) {
1413                         /* The nil UUID is reserved for pre-2.11 clients. */
1414                         ERR("Illegal nil UUID announced by peer in create session command");
1415                         ret = -1;
1416                         goto send_reply;
1417                 }
1418                 LTTNG_OPTIONAL_SET(&id_sessiond, id_sessiond_value);
1419                 LTTNG_OPTIONAL_SET(&creation_time, creation_time_value);
1420                 if (has_current_chunk) {
1421                         LTTNG_OPTIONAL_SET(&current_chunk_id,
1422                                         current_chunk_id_value);
1423                 }
1424         }
1425
1426         if (ret < 0) {
1427                 goto send_reply;
1428         }
1429
1430         session = session_create(session_name, hostname, base_path, live_timer,
1431                         snapshot, sessiond_uuid,
1432                         id_sessiond.is_set ? &id_sessiond.value : NULL,
1433                         current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1434                         creation_time.is_set ? &creation_time.value : NULL,
1435                         conn->major, conn->minor,
1436                         session_name_contains_creation_timestamp);
1437         if (!session) {
1438                 ret = -1;
1439                 goto send_reply;
1440         }
1441         LTTNG_ASSERT(!conn->session);
1442         conn->session = session;
1443         DBG("Created session %" PRIu64, session->id);
1444
1445         reply.generic.session_id = htobe64(session->id);
1446
1447 send_reply:
1448         if (ret < 0) {
1449                 reply.generic.ret_code = htobe32(LTTNG_ERR_FATAL);
1450         } else {
1451                 reply.generic.ret_code = htobe32(LTTNG_OK);
1452         }
1453
1454         if (conn->minor < 11) {
1455                 /* From 2.1 to 2.10 */
1456                 ret = lttng_dynamic_buffer_append(&reply_payload,
1457                                 &reply.generic, sizeof(reply.generic));
1458                 if (ret) {
1459                         ERR("Failed to append \"create session\" command reply header to payload buffer");
1460                         ret = -1;
1461                         goto end;
1462                 }
1463         } else {
1464                 const uint32_t output_path_length =
1465                                 session ? strlen(session->output_path) + 1 : 0;
1466
1467                 reply.output_path_length = htobe32(output_path_length);
1468                 ret = lttng_dynamic_buffer_append(
1469                                 &reply_payload, &reply, sizeof(reply));
1470                 if (ret) {
1471                         ERR("Failed to append \"create session\" command reply header to payload buffer");
1472                         goto end;
1473                 }
1474
1475                 if (output_path_length) {
1476                         ret = lttng_dynamic_buffer_append(&reply_payload,
1477                                         session->output_path,
1478                                         output_path_length);
1479                         if (ret) {
1480                                 ERR("Failed to append \"create session\" command reply path to payload buffer");
1481                                 goto end;
1482                         }
1483                 }
1484         }
1485
1486         send_ret = conn->sock->ops->sendmsg(conn->sock, reply_payload.data,
1487                         reply_payload.size, 0);
1488         if (send_ret < (ssize_t) reply_payload.size) {
1489                 ERR("Failed to send \"create session\" command reply of %zu bytes (ret = %zd)",
1490                                 reply_payload.size, send_ret);
1491                 ret = -1;
1492         }
1493 end:
1494         if (ret < 0 && session) {
1495                 session_put(session);
1496         }
1497         lttng_dynamic_buffer_reset(&reply_payload);
1498         return ret;
1499 }
1500
1501 /*
1502  * When we have received all the streams and the metadata for a channel,
1503  * we make them visible to the viewer threads.
1504  */
1505 static void publish_connection_local_streams(struct relay_connection *conn)
1506 {
1507         struct relay_stream *stream;
1508         struct relay_session *session = conn->session;
1509
1510         /*
1511          * We publish all streams belonging to a session atomically wrt
1512          * session lock.
1513          */
1514         pthread_mutex_lock(&session->lock);
1515         rcu_read_lock();
1516         cds_list_for_each_entry_rcu(stream, &session->recv_list,
1517                         recv_node) {
1518                 stream_publish(stream);
1519         }
1520         rcu_read_unlock();
1521
1522         /*
1523          * Inform the viewer that there are new streams in the session.
1524          */
1525         if (session->viewer_attached) {
1526                 uatomic_set(&session->new_streams, 1);
1527         }
1528         pthread_mutex_unlock(&session->lock);
1529 }
1530
1531 static int conform_channel_path(char *channel_path)
1532 {
1533         int ret = 0;
1534
1535         if (strstr("../", channel_path)) {
1536                 ERR("Refusing channel path as it walks up the path hierarchy: \"%s\"",
1537                                 channel_path);
1538                 ret = -1;
1539                 goto end;
1540         }
1541
1542         if (*channel_path == '/') {
1543                 const size_t len = strlen(channel_path);
1544
1545                 /*
1546                  * Channel paths from peers prior to 2.11 are expressed as an
1547                  * absolute path that is, in reality, relative to the relay
1548                  * daemon's output directory. Remove the leading slash so it
1549                  * is correctly interpreted as a relative path later on.
1550                  *
1551                  * len (and not len - 1) is used to copy the trailing NULL.
1552                  */
1553                 bcopy(channel_path + 1, channel_path, len);
1554         }
1555 end:
1556         return ret;
1557 }
1558
1559 /*
1560  * relay_add_stream: allocate a new stream for a session
1561  */
1562 static int relay_add_stream(const struct lttcomm_relayd_hdr *recv_hdr,
1563                 struct relay_connection *conn,
1564                 const struct lttng_buffer_view *payload)
1565 {
1566         int ret;
1567         ssize_t send_ret;
1568         struct relay_session *session = conn->session;
1569         struct relay_stream *stream = NULL;
1570         struct lttcomm_relayd_status_stream reply;
1571         struct ctf_trace *trace = NULL;
1572         uint64_t stream_handle = -1ULL;
1573         char *path_name = NULL, *channel_name = NULL;
1574         uint64_t tracefile_size = 0, tracefile_count = 0;
1575         LTTNG_OPTIONAL(uint64_t) stream_chunk_id = {};
1576
1577         if (!session || !conn->version_check_done) {
1578                 ERR("Trying to add a stream before version check");
1579                 ret = -1;
1580                 goto end_no_session;
1581         }
1582
1583         if (session->minor == 1) {
1584                 /* For 2.1 */
1585                 ret = cmd_recv_stream_2_1(payload, &path_name,
1586                         &channel_name);
1587         } else if (session->minor > 1 && session->minor < 11) {
1588                 /* From 2.2 to 2.10 */
1589                 ret = cmd_recv_stream_2_2(payload, &path_name,
1590                         &channel_name, &tracefile_size, &tracefile_count);
1591         } else {
1592                 /* From 2.11 to ... */
1593                 ret = cmd_recv_stream_2_11(payload, &path_name,
1594                         &channel_name, &tracefile_size, &tracefile_count,
1595                         &stream_chunk_id.value);
1596                 stream_chunk_id.is_set = true;
1597         }
1598
1599         if (ret < 0) {
1600                 goto send_reply;
1601         }
1602
1603         if (conform_channel_path(path_name)) {
1604                 goto send_reply;
1605         }
1606
1607         /*
1608          * Backward compatibility for --group-output-by-session.
1609          * Prior to lttng 2.11, the complete path is passed by the stream.
1610          * Starting at 2.11, lttng-relayd uses chunk. When dealing with producer
1611          * >=2.11 the chunk is responsible for the output path. When dealing
1612          * with producer < 2.11 the chunk output_path is the root output path
1613          * and the stream carries the complete path (path_name).
1614          * To support --group-output-by-session with older producer (<2.11), we
1615          * need to craft the path based on the stream path.
1616          */
1617         if (opt_group_output_by == RELAYD_GROUP_OUTPUT_BY_SESSION) {
1618                 if (conn->minor < 4) {
1619                         /*
1620                          * From 2.1 to 2.3, the session_name is not passed on
1621                          * the RELAYD_CREATE_SESSION command. The session name
1622                          * is necessary to detect the presence of a base_path
1623                          * inside the stream path. Without it we cannot perform
1624                          * a valid group-output-by-session transformation.
1625                          */
1626                         WARN("Unable to perform a --group-by-session transformation for session %" PRIu64
1627                              " for stream with path \"%s\" as it is produced by a peer using a protocol older than v2.4",
1628                                         session->id, path_name);
1629                 } else if (conn->minor >= 4 && conn->minor < 11) {
1630                         char *group_by_session_path_name;
1631
1632                         LTTNG_ASSERT(session->session_name[0] != '\0');
1633
1634                         group_by_session_path_name =
1635                                         backward_compat_group_by_session(
1636                                                         path_name,
1637                                                         session->session_name,
1638                                                         session->creation_time.value);
1639                         if (!group_by_session_path_name) {
1640                                 ERR("Failed to apply group by session to stream of session %" PRIu64,
1641                                                 session->id);
1642                                 goto send_reply;
1643                         }
1644
1645                         DBG("Transformed session path from \"%s\" to \"%s\" to honor per-session name grouping",
1646                                         path_name, group_by_session_path_name);
1647
1648                         free(path_name);
1649                         path_name = group_by_session_path_name;
1650                 }
1651         }
1652
1653         trace = ctf_trace_get_by_path_or_create(session, path_name);
1654         if (!trace) {
1655                 goto send_reply;
1656         }
1657
1658         /* This stream here has one reference on the trace. */
1659         pthread_mutex_lock(&last_relay_stream_id_lock);
1660         stream_handle = ++last_relay_stream_id;
1661         pthread_mutex_unlock(&last_relay_stream_id_lock);
1662
1663         /* We pass ownership of path_name and channel_name. */
1664         stream = stream_create(trace, stream_handle, path_name,
1665                 channel_name, tracefile_size, tracefile_count);
1666         path_name = NULL;
1667         channel_name = NULL;
1668
1669         /*
1670          * Streams are the owners of their trace. Reference to trace is
1671          * kept within stream_create().
1672          */
1673         ctf_trace_put(trace);
1674
1675 send_reply:
1676         memset(&reply, 0, sizeof(reply));
1677         reply.handle = htobe64(stream_handle);
1678         if (!stream) {
1679                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1680         } else {
1681                 reply.ret_code = htobe32(LTTNG_OK);
1682         }
1683
1684         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
1685                         sizeof(struct lttcomm_relayd_status_stream), 0);
1686         if (send_ret < (ssize_t) sizeof(reply)) {
1687                 ERR("Failed to send \"add stream\" command reply (ret = %zd)",
1688                                 send_ret);
1689                 ret = -1;
1690         }
1691
1692 end_no_session:
1693         free(path_name);
1694         free(channel_name);
1695         return ret;
1696 }
1697
1698 /*
1699  * relay_close_stream: close a specific stream
1700  */
1701 static int relay_close_stream(const struct lttcomm_relayd_hdr *recv_hdr,
1702                 struct relay_connection *conn,
1703                 const struct lttng_buffer_view *payload)
1704 {
1705         int ret;
1706         ssize_t send_ret;
1707         struct relay_session *session = conn->session;
1708         struct lttcomm_relayd_close_stream stream_info;
1709         struct lttcomm_relayd_generic_reply reply;
1710         struct relay_stream *stream;
1711
1712         DBG("Close stream received");
1713
1714         if (!session || !conn->version_check_done) {
1715                 ERR("Trying to close a stream before version check");
1716                 ret = -1;
1717                 goto end_no_session;
1718         }
1719
1720         if (payload->size < sizeof(stream_info)) {
1721                 ERR("Unexpected payload size in \"relay_close_stream\": expected >= %zu bytes, got %zu bytes",
1722                                 sizeof(stream_info), payload->size);
1723                 ret = -1;
1724                 goto end_no_session;
1725         }
1726         memcpy(&stream_info, payload->data, sizeof(stream_info));
1727         stream_info.stream_id = be64toh(stream_info.stream_id);
1728         stream_info.last_net_seq_num = be64toh(stream_info.last_net_seq_num);
1729
1730         stream = stream_get_by_id(stream_info.stream_id);
1731         if (!stream) {
1732                 ret = -1;
1733                 goto end;
1734         }
1735
1736         /*
1737          * Set last_net_seq_num before the close flag. Required by data
1738          * pending check.
1739          */
1740         pthread_mutex_lock(&stream->lock);
1741         stream->last_net_seq_num = stream_info.last_net_seq_num;
1742         pthread_mutex_unlock(&stream->lock);
1743
1744         /*
1745          * This is one of the conditions which may trigger a stream close
1746          * with the others being:
1747          *     1) A close command is received for a stream
1748          *     2) The control connection owning the stream is closed
1749          *     3) We have received all of the stream's data _after_ a close
1750          *        request.
1751          */
1752         try_stream_close(stream);
1753         if (stream->is_metadata) {
1754                 struct relay_viewer_stream *vstream;
1755
1756                 vstream = viewer_stream_get_by_id(stream->stream_handle);
1757                 if (vstream) {
1758                         if (stream->no_new_metadata_notified) {
1759                                 /*
1760                                  * Since all the metadata has been sent to the
1761                                  * viewer and that we have a request to close
1762                                  * its stream, we can safely teardown the
1763                                  * corresponding metadata viewer stream.
1764                                  */
1765                                 viewer_stream_put(vstream);
1766                         }
1767                         /* Put local reference. */
1768                         viewer_stream_put(vstream);
1769                 }
1770         }
1771         stream_put(stream);
1772         ret = 0;
1773
1774 end:
1775         memset(&reply, 0, sizeof(reply));
1776         if (ret < 0) {
1777                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1778         } else {
1779                 reply.ret_code = htobe32(LTTNG_OK);
1780         }
1781         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
1782                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1783         if (send_ret < (ssize_t) sizeof(reply)) {
1784                 ERR("Failed to send \"close stream\" command reply (ret = %zd)",
1785                                 send_ret);
1786                 ret = -1;
1787         }
1788
1789 end_no_session:
1790         return ret;
1791 }
1792
1793 /*
1794  * relay_reset_metadata: reset a metadata stream
1795  */
1796 static
1797 int relay_reset_metadata(const struct lttcomm_relayd_hdr *recv_hdr,
1798                 struct relay_connection *conn,
1799                 const struct lttng_buffer_view *payload)
1800 {
1801         int ret;
1802         ssize_t send_ret;
1803         struct relay_session *session = conn->session;
1804         struct lttcomm_relayd_reset_metadata stream_info;
1805         struct lttcomm_relayd_generic_reply reply;
1806         struct relay_stream *stream;
1807
1808         DBG("Reset metadata received");
1809
1810         if (!session || !conn->version_check_done) {
1811                 ERR("Trying to reset a metadata stream before version check");
1812                 ret = -1;
1813                 goto end_no_session;
1814         }
1815
1816         if (payload->size < sizeof(stream_info)) {
1817                 ERR("Unexpected payload size in \"relay_reset_metadata\": expected >= %zu bytes, got %zu bytes",
1818                                 sizeof(stream_info), payload->size);
1819                 ret = -1;
1820                 goto end_no_session;
1821         }
1822         memcpy(&stream_info, payload->data, sizeof(stream_info));
1823         stream_info.stream_id = be64toh(stream_info.stream_id);
1824         stream_info.version = be64toh(stream_info.version);
1825
1826         DBG("Update metadata to version %" PRIu64, stream_info.version);
1827
1828         /* Unsupported for live sessions for now. */
1829         if (session->live_timer != 0) {
1830                 ret = -1;
1831                 goto end;
1832         }
1833
1834         stream = stream_get_by_id(stream_info.stream_id);
1835         if (!stream) {
1836                 ret = -1;
1837                 goto end;
1838         }
1839         pthread_mutex_lock(&stream->lock);
1840         if (!stream->is_metadata) {
1841                 ret = -1;
1842                 goto end_unlock;
1843         }
1844
1845         ret = stream_reset_file(stream);
1846         if (ret < 0) {
1847                 ERR("Failed to reset metadata stream %" PRIu64
1848                                 ": stream_path = %s, channel = %s",
1849                                 stream->stream_handle, stream->path_name,
1850                                 stream->channel_name);
1851                 goto end_unlock;
1852         }
1853 end_unlock:
1854         pthread_mutex_unlock(&stream->lock);
1855         stream_put(stream);
1856
1857 end:
1858         memset(&reply, 0, sizeof(reply));
1859         if (ret < 0) {
1860                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1861         } else {
1862                 reply.ret_code = htobe32(LTTNG_OK);
1863         }
1864         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
1865                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1866         if (send_ret < (ssize_t) sizeof(reply)) {
1867                 ERR("Failed to send \"reset metadata\" command reply (ret = %zd)",
1868                                 send_ret);
1869                 ret = -1;
1870         }
1871
1872 end_no_session:
1873         return ret;
1874 }
1875
1876 /*
1877  * relay_unknown_command: send -1 if received unknown command
1878  */
1879 static void relay_unknown_command(struct relay_connection *conn)
1880 {
1881         struct lttcomm_relayd_generic_reply reply;
1882         ssize_t send_ret;
1883
1884         memset(&reply, 0, sizeof(reply));
1885         reply.ret_code = htobe32(LTTNG_ERR_UNK);
1886         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
1887         if (send_ret < sizeof(reply)) {
1888                 ERR("Failed to send \"unknown command\" command reply (ret = %zd)", send_ret);
1889         }
1890 }
1891
1892 /*
1893  * relay_start: send an acknowledgment to the client to tell if we are
1894  * ready to receive data. We are ready if a session is established.
1895  */
1896 static int relay_start(const struct lttcomm_relayd_hdr *recv_hdr,
1897                 struct relay_connection *conn,
1898                 const struct lttng_buffer_view *payload)
1899 {
1900         int ret = 0;
1901         ssize_t send_ret;
1902         struct lttcomm_relayd_generic_reply reply;
1903         struct relay_session *session = conn->session;
1904
1905         if (!session) {
1906                 DBG("Trying to start the streaming without a session established");
1907                 ret = htobe32(LTTNG_ERR_UNK);
1908         }
1909
1910         memset(&reply, 0, sizeof(reply));
1911         reply.ret_code = htobe32(LTTNG_OK);
1912         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
1913                         sizeof(reply), 0);
1914         if (send_ret < (ssize_t) sizeof(reply)) {
1915                 ERR("Failed to send \"relay_start\" command reply (ret = %zd)",
1916                                 send_ret);
1917                 ret = -1;
1918         }
1919
1920         return ret;
1921 }
1922
1923 /*
1924  * relay_recv_metadata: receive the metadata for the session.
1925  */
1926 static int relay_recv_metadata(const struct lttcomm_relayd_hdr *recv_hdr,
1927                 struct relay_connection *conn,
1928                 const struct lttng_buffer_view *payload)
1929 {
1930         int ret = 0;
1931         struct relay_session *session = conn->session;
1932         struct lttcomm_relayd_metadata_payload metadata_payload_header;
1933         struct relay_stream *metadata_stream;
1934         uint64_t metadata_payload_size;
1935         struct lttng_buffer_view packet_view;
1936
1937         if (!session) {
1938                 ERR("Metadata sent before version check");
1939                 ret = -1;
1940                 goto end;
1941         }
1942
1943         if (recv_hdr->data_size < sizeof(struct lttcomm_relayd_metadata_payload)) {
1944                 ERR("Incorrect data size");
1945                 ret = -1;
1946                 goto end;
1947         }
1948         metadata_payload_size = recv_hdr->data_size -
1949                         sizeof(struct lttcomm_relayd_metadata_payload);
1950
1951         memcpy(&metadata_payload_header, payload->data,
1952                         sizeof(metadata_payload_header));
1953         metadata_payload_header.stream_id = be64toh(
1954                         metadata_payload_header.stream_id);
1955         metadata_payload_header.padding_size = be32toh(
1956                         metadata_payload_header.padding_size);
1957
1958         metadata_stream = stream_get_by_id(metadata_payload_header.stream_id);
1959         if (!metadata_stream) {
1960                 ret = -1;
1961                 goto end;
1962         }
1963
1964         packet_view = lttng_buffer_view_from_view(payload,
1965                         sizeof(metadata_payload_header), metadata_payload_size);
1966         if (!lttng_buffer_view_is_valid(&packet_view)) {
1967                 ERR("Invalid metadata packet length announced by header");
1968                 ret = -1;
1969                 goto end_put;
1970         }
1971
1972         pthread_mutex_lock(&metadata_stream->lock);
1973         ret = stream_write(metadata_stream, &packet_view,
1974                         metadata_payload_header.padding_size);
1975         pthread_mutex_unlock(&metadata_stream->lock);
1976         if (ret){
1977                 ret = -1;
1978                 goto end_put;
1979         }
1980 end_put:
1981         stream_put(metadata_stream);
1982 end:
1983         return ret;
1984 }
1985
1986 /*
1987  * relay_send_version: send relayd version number
1988  */
1989 static int relay_send_version(const struct lttcomm_relayd_hdr *recv_hdr,
1990                 struct relay_connection *conn,
1991                 const struct lttng_buffer_view *payload)
1992 {
1993         int ret;
1994         ssize_t send_ret;
1995         struct lttcomm_relayd_version reply, msg;
1996         bool compatible = true;
1997
1998         conn->version_check_done = true;
1999
2000         /* Get version from the other side. */
2001         if (payload->size < sizeof(msg)) {
2002                 ERR("Unexpected payload size in \"relay_send_version\": expected >= %zu bytes, got %zu bytes",
2003                                 sizeof(msg), payload->size);
2004                 ret = -1;
2005                 goto end;
2006         }
2007
2008         memcpy(&msg, payload->data, sizeof(msg));
2009         msg.major = be32toh(msg.major);
2010         msg.minor = be32toh(msg.minor);
2011
2012         memset(&reply, 0, sizeof(reply));
2013         reply.major = RELAYD_VERSION_COMM_MAJOR;
2014         reply.minor = RELAYD_VERSION_COMM_MINOR;
2015
2016         /* Major versions must be the same */
2017         if (reply.major != msg.major) {
2018                 DBG("Incompatible major versions (%u vs %u), deleting session",
2019                                 reply.major, msg.major);
2020                 compatible = false;
2021         }
2022
2023         conn->major = reply.major;
2024         /* We adapt to the lowest compatible version */
2025         if (reply.minor <= msg.minor) {
2026                 conn->minor = reply.minor;
2027         } else {
2028                 conn->minor = msg.minor;
2029         }
2030
2031         reply.major = htobe32(reply.major);
2032         reply.minor = htobe32(reply.minor);
2033         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
2034                         sizeof(reply), 0);
2035         if (send_ret < (ssize_t) sizeof(reply)) {
2036                 ERR("Failed to send \"send version\" command reply (ret = %zd)",
2037                                 send_ret);
2038                 ret = -1;
2039                 goto end;
2040         } else {
2041                 ret = 0;
2042         }
2043
2044         if (!compatible) {
2045                 ret = -1;
2046                 goto end;
2047         }
2048
2049         DBG("Version check done using protocol %u.%u", conn->major,
2050                         conn->minor);
2051
2052 end:
2053         return ret;
2054 }
2055
2056 /*
2057  * Check for data pending for a given stream id from the session daemon.
2058  */
2059 static int relay_data_pending(const struct lttcomm_relayd_hdr *recv_hdr,
2060                 struct relay_connection *conn,
2061                 const struct lttng_buffer_view *payload)
2062 {
2063         struct relay_session *session = conn->session;
2064         struct lttcomm_relayd_data_pending msg;
2065         struct lttcomm_relayd_generic_reply reply;
2066         struct relay_stream *stream;
2067         ssize_t send_ret;
2068         int ret;
2069         uint64_t stream_seq;
2070
2071         DBG("Data pending command received");
2072
2073         if (!session || !conn->version_check_done) {
2074                 ERR("Trying to check for data before version check");
2075                 ret = -1;
2076                 goto end_no_session;
2077         }
2078
2079         if (payload->size < sizeof(msg)) {
2080                 ERR("Unexpected payload size in \"relay_data_pending\": expected >= %zu bytes, got %zu bytes",
2081                                 sizeof(msg), payload->size);
2082                 ret = -1;
2083                 goto end_no_session;
2084         }
2085         memcpy(&msg, payload->data, sizeof(msg));
2086         msg.stream_id = be64toh(msg.stream_id);
2087         msg.last_net_seq_num = be64toh(msg.last_net_seq_num);
2088
2089         stream = stream_get_by_id(msg.stream_id);
2090         if (stream == NULL) {
2091                 ret = -1;
2092                 goto end;
2093         }
2094
2095         pthread_mutex_lock(&stream->lock);
2096
2097         if (session_streams_have_index(session)) {
2098                 /*
2099                  * Ensure that both the index and stream data have been
2100                  * flushed up to the requested point.
2101                  */
2102                 stream_seq = min(stream->prev_data_seq, stream->prev_index_seq);
2103         } else {
2104                 stream_seq = stream->prev_data_seq;
2105         }
2106         DBG("Data pending for stream id %" PRIu64 ": prev_data_seq %" PRIu64
2107                         ", prev_index_seq %" PRIu64
2108                         ", and last_seq %" PRIu64, msg.stream_id,
2109                         stream->prev_data_seq, stream->prev_index_seq,
2110                         msg.last_net_seq_num);
2111
2112         /* Avoid wrapping issue */
2113         if (((int64_t) (stream_seq - msg.last_net_seq_num)) >= 0) {
2114                 /* Data has in fact been written and is NOT pending */
2115                 ret = 0;
2116         } else {
2117                 /* Data still being streamed thus pending */
2118                 ret = 1;
2119         }
2120
2121         stream->data_pending_check_done = true;
2122         pthread_mutex_unlock(&stream->lock);
2123
2124         stream_put(stream);
2125 end:
2126
2127         memset(&reply, 0, sizeof(reply));
2128         reply.ret_code = htobe32(ret);
2129         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2130         if (send_ret < (ssize_t) sizeof(reply)) {
2131                 ERR("Failed to send \"data pending\" command reply (ret = %zd)",
2132                                 send_ret);
2133                 ret = -1;
2134         }
2135
2136 end_no_session:
2137         return ret;
2138 }
2139
2140 /*
2141  * Wait for the control socket to reach a quiescent state.
2142  *
2143  * Note that for now, when receiving this command from the session
2144  * daemon, this means that every subsequent commands or data received on
2145  * the control socket has been handled. So, this is why we simply return
2146  * OK here.
2147  */
2148 static int relay_quiescent_control(const struct lttcomm_relayd_hdr *recv_hdr,
2149                 struct relay_connection *conn,
2150                 const struct lttng_buffer_view *payload)
2151 {
2152         int ret;
2153         ssize_t send_ret;
2154         struct relay_stream *stream;
2155         struct lttcomm_relayd_quiescent_control msg;
2156         struct lttcomm_relayd_generic_reply reply;
2157
2158         DBG("Checking quiescent state on control socket");
2159
2160         if (!conn->session || !conn->version_check_done) {
2161                 ERR("Trying to check for data before version check");
2162                 ret = -1;
2163                 goto end_no_session;
2164         }
2165
2166         if (payload->size < sizeof(msg)) {
2167                 ERR("Unexpected payload size in \"relay_quiescent_control\": expected >= %zu bytes, got %zu bytes",
2168                                 sizeof(msg), payload->size);
2169                 ret = -1;
2170                 goto end_no_session;
2171         }
2172         memcpy(&msg, payload->data, sizeof(msg));
2173         msg.stream_id = be64toh(msg.stream_id);
2174
2175         stream = stream_get_by_id(msg.stream_id);
2176         if (!stream) {
2177                 goto reply;
2178         }
2179         pthread_mutex_lock(&stream->lock);
2180         stream->data_pending_check_done = true;
2181         pthread_mutex_unlock(&stream->lock);
2182
2183         DBG("Relay quiescent control pending flag set to %" PRIu64, msg.stream_id);
2184         stream_put(stream);
2185 reply:
2186         memset(&reply, 0, sizeof(reply));
2187         reply.ret_code = htobe32(LTTNG_OK);
2188         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2189         if (send_ret < (ssize_t) sizeof(reply)) {
2190                 ERR("Failed to send \"quiescent control\" command reply (ret = %zd)",
2191                                 send_ret);
2192                 ret = -1;
2193         } else {
2194                 ret = 0;
2195         }
2196
2197 end_no_session:
2198         return ret;
2199 }
2200
2201 /*
2202  * Initialize a data pending command. This means that a consumer is about
2203  * to ask for data pending for each stream it holds. Simply iterate over
2204  * all streams of a session and set the data_pending_check_done flag.
2205  *
2206  * This command returns to the client a LTTNG_OK code.
2207  */
2208 static int relay_begin_data_pending(const struct lttcomm_relayd_hdr *recv_hdr,
2209                 struct relay_connection *conn,
2210                 const struct lttng_buffer_view *payload)
2211 {
2212         int ret;
2213         ssize_t send_ret;
2214         struct lttng_ht_iter iter;
2215         struct lttcomm_relayd_begin_data_pending msg;
2216         struct lttcomm_relayd_generic_reply reply;
2217         struct relay_stream *stream;
2218
2219         LTTNG_ASSERT(recv_hdr);
2220         LTTNG_ASSERT(conn);
2221
2222         DBG("Init streams for data pending");
2223
2224         if (!conn->session || !conn->version_check_done) {
2225                 ERR("Trying to check for data before version check");
2226                 ret = -1;
2227                 goto end_no_session;
2228         }
2229
2230         if (payload->size < sizeof(msg)) {
2231                 ERR("Unexpected payload size in \"relay_begin_data_pending\": expected >= %zu bytes, got %zu bytes",
2232                                 sizeof(msg), payload->size);
2233                 ret = -1;
2234                 goto end_no_session;
2235         }
2236         memcpy(&msg, payload->data, sizeof(msg));
2237         msg.session_id = be64toh(msg.session_id);
2238
2239         /*
2240          * Iterate over all streams to set the begin data pending flag.
2241          * For now, the streams are indexed by stream handle so we have
2242          * to iterate over all streams to find the one associated with
2243          * the right session_id.
2244          */
2245         rcu_read_lock();
2246         cds_lfht_for_each_entry(relay_streams_ht->ht, &iter.iter, stream,
2247                         node.node) {
2248                 if (!stream_get(stream)) {
2249                         continue;
2250                 }
2251                 if (stream->trace->session->id == msg.session_id) {
2252                         pthread_mutex_lock(&stream->lock);
2253                         stream->data_pending_check_done = false;
2254                         pthread_mutex_unlock(&stream->lock);
2255                         DBG("Set begin data pending flag to stream %" PRIu64,
2256                                         stream->stream_handle);
2257                 }
2258                 stream_put(stream);
2259         }
2260         rcu_read_unlock();
2261
2262         memset(&reply, 0, sizeof(reply));
2263         /* All good, send back reply. */
2264         reply.ret_code = htobe32(LTTNG_OK);
2265
2266         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2267         if (send_ret < (ssize_t) sizeof(reply)) {
2268                 ERR("Failed to send \"begin data pending\" command reply (ret = %zd)",
2269                         send_ret);
2270                 ret = -1;
2271         } else {
2272                 ret = 0;
2273         }
2274
2275 end_no_session:
2276         return ret;
2277 }
2278
2279 /*
2280  * End data pending command. This will check, for a given session id, if
2281  * each stream associated with it has its data_pending_check_done flag
2282  * set. If not, this means that the client lost track of the stream but
2283  * the data is still being streamed on our side. In this case, we inform
2284  * the client that data is in flight.
2285  *
2286  * Return to the client if there is data in flight or not with a ret_code.
2287  */
2288 static int relay_end_data_pending(const struct lttcomm_relayd_hdr *recv_hdr,
2289                 struct relay_connection *conn,
2290                 const struct lttng_buffer_view *payload)
2291 {
2292         int ret;
2293         ssize_t send_ret;
2294         struct lttng_ht_iter iter;
2295         struct lttcomm_relayd_end_data_pending msg;
2296         struct lttcomm_relayd_generic_reply reply;
2297         struct relay_stream *stream;
2298         uint32_t is_data_inflight = 0;
2299
2300         DBG("End data pending command");
2301
2302         if (!conn->session || !conn->version_check_done) {
2303                 ERR("Trying to check for data before version check");
2304                 ret = -1;
2305                 goto end_no_session;
2306         }
2307
2308         if (payload->size < sizeof(msg)) {
2309                 ERR("Unexpected payload size in \"relay_end_data_pending\": expected >= %zu bytes, got %zu bytes",
2310                                 sizeof(msg), payload->size);
2311                 ret = -1;
2312                 goto end_no_session;
2313         }
2314         memcpy(&msg, payload->data, sizeof(msg));
2315         msg.session_id = be64toh(msg.session_id);
2316
2317         /*
2318          * Iterate over all streams to see if the begin data pending
2319          * flag is set.
2320          */
2321         rcu_read_lock();
2322         cds_lfht_for_each_entry(relay_streams_ht->ht, &iter.iter, stream,
2323                         node.node) {
2324                 if (!stream_get(stream)) {
2325                         continue;
2326                 }
2327                 if (stream->trace->session->id != msg.session_id) {
2328                         stream_put(stream);
2329                         continue;
2330                 }
2331                 pthread_mutex_lock(&stream->lock);
2332                 if (!stream->data_pending_check_done) {
2333                         uint64_t stream_seq;
2334
2335                         if (session_streams_have_index(conn->session)) {
2336                                 /*
2337                                  * Ensure that both the index and stream data have been
2338                                  * flushed up to the requested point.
2339                                  */
2340                                 stream_seq = min(stream->prev_data_seq, stream->prev_index_seq);
2341                         } else {
2342                                 stream_seq = stream->prev_data_seq;
2343                         }
2344                         if (!stream->closed || !(((int64_t) (stream_seq - stream->last_net_seq_num)) >= 0)) {
2345                                 is_data_inflight = 1;
2346                                 DBG("Data is still in flight for stream %" PRIu64,
2347                                                 stream->stream_handle);
2348                                 pthread_mutex_unlock(&stream->lock);
2349                                 stream_put(stream);
2350                                 break;
2351                         }
2352                 }
2353                 pthread_mutex_unlock(&stream->lock);
2354                 stream_put(stream);
2355         }
2356         rcu_read_unlock();
2357
2358         memset(&reply, 0, sizeof(reply));
2359         /* All good, send back reply. */
2360         reply.ret_code = htobe32(is_data_inflight);
2361
2362         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2363         if (send_ret < (ssize_t) sizeof(reply)) {
2364                 ERR("Failed to send \"end data pending\" command reply (ret = %zd)",
2365                         send_ret);
2366                 ret = -1;
2367         } else {
2368                 ret = 0;
2369         }
2370
2371 end_no_session:
2372         return ret;
2373 }
2374
2375 /*
2376  * Receive an index for a specific stream.
2377  *
2378  * Return 0 on success else a negative value.
2379  */
2380 static int relay_recv_index(const struct lttcomm_relayd_hdr *recv_hdr,
2381                 struct relay_connection *conn,
2382                 const struct lttng_buffer_view *payload)
2383 {
2384         int ret;
2385         ssize_t send_ret;
2386         struct relay_session *session = conn->session;
2387         struct lttcomm_relayd_index index_info;
2388         struct lttcomm_relayd_generic_reply reply;
2389         struct relay_stream *stream;
2390         size_t msg_len;
2391
2392         LTTNG_ASSERT(conn);
2393
2394         DBG("Relay receiving index");
2395
2396         if (!session || !conn->version_check_done) {
2397                 ERR("Trying to close a stream before version check");
2398                 ret = -1;
2399                 goto end_no_session;
2400         }
2401
2402         msg_len = lttcomm_relayd_index_len(
2403                         lttng_to_index_major(conn->major, conn->minor),
2404                         lttng_to_index_minor(conn->major, conn->minor));
2405         if (payload->size < msg_len) {
2406                 ERR("Unexpected payload size in \"relay_recv_index\": expected >= %zu bytes, got %zu bytes",
2407                                 msg_len, payload->size);
2408                 ret = -1;
2409                 goto end_no_session;
2410         }
2411         memcpy(&index_info, payload->data, msg_len);
2412         index_info.relay_stream_id = be64toh(index_info.relay_stream_id);
2413         index_info.net_seq_num = be64toh(index_info.net_seq_num);
2414         index_info.packet_size = be64toh(index_info.packet_size);
2415         index_info.content_size = be64toh(index_info.content_size);
2416         index_info.timestamp_begin = be64toh(index_info.timestamp_begin);
2417         index_info.timestamp_end = be64toh(index_info.timestamp_end);
2418         index_info.events_discarded = be64toh(index_info.events_discarded);
2419         index_info.stream_id = be64toh(index_info.stream_id);
2420
2421         if (conn->minor >= 8) {
2422                 index_info.stream_instance_id =
2423                                 be64toh(index_info.stream_instance_id);
2424                 index_info.packet_seq_num = be64toh(index_info.packet_seq_num);
2425         } else {
2426                 index_info.stream_instance_id = -1ULL;
2427                 index_info.packet_seq_num = -1ULL;
2428         }
2429
2430         stream = stream_get_by_id(index_info.relay_stream_id);
2431         if (!stream) {
2432                 ERR("stream_get_by_id not found");
2433                 ret = -1;
2434                 goto end;
2435         }
2436
2437         pthread_mutex_lock(&stream->lock);
2438         ret = stream_add_index(stream, &index_info);
2439         pthread_mutex_unlock(&stream->lock);
2440         if (ret) {
2441                 goto end_stream_put;
2442         }
2443
2444 end_stream_put:
2445         stream_put(stream);
2446 end:
2447         memset(&reply, 0, sizeof(reply));
2448         if (ret < 0) {
2449                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
2450         } else {
2451                 reply.ret_code = htobe32(LTTNG_OK);
2452         }
2453         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2454         if (send_ret < (ssize_t) sizeof(reply)) {
2455                 ERR("Failed to send \"recv index\" command reply (ret = %zd)", send_ret);
2456                 ret = -1;
2457         }
2458
2459 end_no_session:
2460         return ret;
2461 }
2462
2463 /*
2464  * Receive the streams_sent message.
2465  *
2466  * Return 0 on success else a negative value.
2467  */
2468 static int relay_streams_sent(const struct lttcomm_relayd_hdr *recv_hdr,
2469                 struct relay_connection *conn,
2470                 const struct lttng_buffer_view *payload)
2471 {
2472         int ret;
2473         ssize_t send_ret;
2474         struct lttcomm_relayd_generic_reply reply;
2475
2476         LTTNG_ASSERT(conn);
2477
2478         DBG("Relay receiving streams_sent");
2479
2480         if (!conn->session || !conn->version_check_done) {
2481                 ERR("Trying to close a stream before version check");
2482                 ret = -1;
2483                 goto end_no_session;
2484         }
2485
2486         /*
2487          * Publish every pending stream in the connection recv list which are
2488          * now ready to be used by the viewer.
2489          */
2490         publish_connection_local_streams(conn);
2491
2492         memset(&reply, 0, sizeof(reply));
2493         reply.ret_code = htobe32(LTTNG_OK);
2494         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply, sizeof(reply), 0);
2495         if (send_ret < (ssize_t) sizeof(reply)) {
2496                 ERR("Failed to send \"streams sent\" command reply (ret = %zd)",
2497                         send_ret);
2498                 ret = -1;
2499         } else {
2500                 /* Success. */
2501                 ret = 0;
2502         }
2503
2504 end_no_session:
2505         return ret;
2506 }
2507
2508 /*
2509  * relay_rotate_session_stream: rotate a stream to a new tracefile for the
2510  * session rotation feature (not the tracefile rotation feature).
2511  */
2512 static int relay_rotate_session_streams(
2513                 const struct lttcomm_relayd_hdr *recv_hdr,
2514                 struct relay_connection *conn,
2515                 const struct lttng_buffer_view *payload)
2516 {
2517         int ret = 0;
2518         uint32_t i;
2519         ssize_t send_ret;
2520         enum lttng_error_code reply_code = LTTNG_ERR_UNK;
2521         struct relay_session *session = conn->session;
2522         struct lttcomm_relayd_rotate_streams rotate_streams;
2523         struct lttcomm_relayd_generic_reply reply = {};
2524         struct relay_stream *stream = NULL;
2525         const size_t header_len = sizeof(struct lttcomm_relayd_rotate_streams);
2526         struct lttng_trace_chunk *next_trace_chunk = NULL;
2527         struct lttng_buffer_view stream_positions;
2528         char chunk_id_buf[MAX_INT_DEC_LEN(uint64_t)];
2529         const char *chunk_id_str = "none";
2530
2531         if (!session || !conn->version_check_done) {
2532                 ERR("Trying to rotate a stream before version check");
2533                 ret = -1;
2534                 goto end_no_reply;
2535         }
2536
2537         if (session->major == 2 && session->minor < 11) {
2538                 ERR("Unsupported feature before 2.11");
2539                 ret = -1;
2540                 goto end_no_reply;
2541         }
2542
2543         if (payload->size < header_len) {
2544                 ERR("Unexpected payload size in \"relay_rotate_session_stream\": expected >= %zu bytes, got %zu bytes",
2545                                 header_len, payload->size);
2546                 ret = -1;
2547                 goto end_no_reply;
2548         }
2549
2550         memcpy(&rotate_streams, payload->data, header_len);
2551
2552         /* Convert header to host endianness. */
2553         rotate_streams = (typeof(rotate_streams)) {
2554                 .stream_count = be32toh(rotate_streams.stream_count),
2555                 .new_chunk_id = (typeof(rotate_streams.new_chunk_id)) {
2556                         .is_set = !!rotate_streams.new_chunk_id.is_set,
2557                         .value = be64toh(rotate_streams.new_chunk_id.value),
2558                 }
2559         };
2560
2561         if (rotate_streams.new_chunk_id.is_set) {
2562                 /*
2563                  * Retrieve the trace chunk the stream must transition to. As
2564                  * per the protocol, this chunk should have been created
2565                  * before this command is received.
2566                  */
2567                 next_trace_chunk = sessiond_trace_chunk_registry_get_chunk(
2568                                 sessiond_trace_chunk_registry,
2569                                 session->sessiond_uuid, session->id,
2570                                 rotate_streams.new_chunk_id.value);
2571                 if (!next_trace_chunk) {
2572                         char uuid_str[LTTNG_UUID_STR_LEN];
2573
2574                         lttng_uuid_to_str(session->sessiond_uuid, uuid_str);
2575                         ERR("Unknown next trace chunk in ROTATE_STREAMS command: sessiond_uuid = {%s}, session_id = %" PRIu64
2576                                         ", trace_chunk_id = %" PRIu64,
2577                                         uuid_str, session->id,
2578                                         rotate_streams.new_chunk_id.value);
2579                         reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2580                         ret = -1;
2581                         goto end;
2582                 }
2583
2584                 ret = snprintf(chunk_id_buf, sizeof(chunk_id_buf), "%" PRIu64,
2585                                 rotate_streams.new_chunk_id.value);
2586                 if (ret < 0 || ret >= sizeof(chunk_id_buf)) {
2587                         chunk_id_str = "formatting error";
2588                 } else {
2589                         chunk_id_str = chunk_id_buf;
2590                 }
2591         }
2592
2593         DBG("Rotate %" PRIu32 " streams of session \"%s\" to chunk \"%s\"",
2594                         rotate_streams.stream_count, session->session_name,
2595                         chunk_id_str);
2596
2597         stream_positions = lttng_buffer_view_from_view(payload,
2598                         sizeof(rotate_streams), -1);
2599         if (!stream_positions.data ||
2600                         stream_positions.size <
2601                                         (rotate_streams.stream_count *
2602                                                         sizeof(struct lttcomm_relayd_stream_rotation_position))) {
2603                 reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2604                 ret = -1;
2605                 goto end;
2606         }
2607
2608         for (i = 0; i < rotate_streams.stream_count; i++) {
2609                 struct lttcomm_relayd_stream_rotation_position *position_comm =
2610                                 &((typeof(position_comm)) stream_positions.data)[i];
2611                 const struct lttcomm_relayd_stream_rotation_position pos = {
2612                         .stream_id = be64toh(position_comm->stream_id),
2613                         .rotate_at_seq_num = be64toh(
2614                                         position_comm->rotate_at_seq_num),
2615                 };
2616
2617                 stream = stream_get_by_id(pos.stream_id);
2618                 if (!stream) {
2619                         reply_code = LTTNG_ERR_INVALID;
2620                         ret = -1;
2621                         goto end;
2622                 }
2623
2624                 pthread_mutex_lock(&stream->lock);
2625                 ret = stream_set_pending_rotation(stream, next_trace_chunk,
2626                                 pos.rotate_at_seq_num);
2627                 pthread_mutex_unlock(&stream->lock);
2628                 if (ret) {
2629                         reply_code = LTTNG_ERR_FILE_CREATION_ERROR;
2630                         goto end;
2631                 }
2632
2633                 stream_put(stream);
2634                 stream = NULL;
2635         }
2636
2637         reply_code = LTTNG_OK;
2638         ret = 0;
2639 end:
2640         if (stream) {
2641                 stream_put(stream);
2642         }
2643
2644         reply.ret_code = htobe32((uint32_t) reply_code);
2645         send_ret = conn->sock->ops->sendmsg(conn->sock, &reply,
2646                         sizeof(struct lttcomm_relayd_generic_reply), 0);
2647         if (send_ret < (ssize_t) sizeof(reply)) {
2648                 ERR("Failed to send \"rotate session stream\" command reply (ret = %zd)",
2649                                 send_ret);
2650                 ret = -1;
2651         }
2652 end_no_reply:
2653         lttng_trace_chunk_put(next_trace_chunk);
2654         return ret;
2655 }
2656
2657
2658
2659 /*
2660  * relay_create_trace_chunk: create a new trace chunk
2661  */
2662 static int relay_create_trace_chunk(const struct lttcomm_relayd_hdr *recv_hdr,
2663                 struct relay_connection *conn,
2664                 const struct lttng_buffer_view *payload)
2665 {
2666         int ret = 0;
2667         ssize_t send_ret;
2668         struct relay_session *session = conn->session;
2669         struct lttcomm_relayd_create_trace_chunk *msg;
2670         struct lttcomm_relayd_generic_reply reply = {};
2671         struct lttng_buffer_view header_view;
2672         struct lttng_trace_chunk *chunk = NULL, *published_chunk = NULL;
2673         enum lttng_error_code reply_code = LTTNG_OK;
2674         enum lttng_trace_chunk_status chunk_status;
2675         const char *new_path;
2676
2677         if (!session || !conn->version_check_done) {
2678                 ERR("Trying to create a trace chunk before version check");
2679                 ret = -1;
2680                 goto end_no_reply;
2681         }
2682
2683         if (session->major == 2 && session->minor < 11) {
2684                 ERR("Chunk creation command is unsupported before 2.11");
2685                 ret = -1;
2686                 goto end_no_reply;
2687         }
2688
2689         header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
2690         if (!lttng_buffer_view_is_valid(&header_view)) {
2691                 ERR("Failed to receive payload of chunk creation command");
2692                 ret = -1;
2693                 goto end_no_reply;
2694         }
2695
2696         /* Convert to host endianness. */
2697         msg = (typeof(msg)) header_view.data;
2698         msg->chunk_id = be64toh(msg->chunk_id);
2699         msg->creation_timestamp = be64toh(msg->creation_timestamp);
2700         msg->override_name_length = be32toh(msg->override_name_length);
2701
2702         if (session->current_trace_chunk &&
2703                         !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
2704                 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
2705                                         DEFAULT_CHUNK_TMP_OLD_DIRECTORY);
2706                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2707                         ERR("Failed to rename old chunk");
2708                         ret = -1;
2709                         reply_code = LTTNG_ERR_UNK;
2710                         goto end;
2711                 }
2712         }
2713         session->ongoing_rotation = true;
2714         if (!session->current_trace_chunk) {
2715                 if (!session->has_rotated) {
2716                         new_path = "";
2717                 } else {
2718                         new_path = NULL;
2719                 }
2720         } else {
2721                 new_path = DEFAULT_CHUNK_TMP_NEW_DIRECTORY;
2722         }
2723         chunk = lttng_trace_chunk_create(
2724                         msg->chunk_id, msg->creation_timestamp, new_path);
2725         if (!chunk) {
2726                 ERR("Failed to create trace chunk in trace chunk creation command");
2727                 ret = -1;
2728                 reply_code = LTTNG_ERR_NOMEM;
2729                 goto end;
2730         }
2731         lttng_trace_chunk_set_fd_tracker(chunk, the_fd_tracker);
2732
2733         if (msg->override_name_length) {
2734                 const char *name;
2735                 const struct lttng_buffer_view chunk_name_view =
2736                                 lttng_buffer_view_from_view(payload,
2737                                                 sizeof(*msg),
2738                                                 msg->override_name_length);
2739
2740                 if (!lttng_buffer_view_is_valid(&chunk_name_view)) {
2741                         ERR("Invalid payload of chunk creation command (protocol error): buffer too short for expected name length");
2742                         ret = -1;
2743                         reply_code = LTTNG_ERR_INVALID;
2744                         goto end;
2745                 }
2746
2747                 name = chunk_name_view.data;
2748                 if (name[msg->override_name_length - 1]) {
2749                         ERR("Invalid payload of chunk creation command (protocol error): name is not null-terminated");
2750                         ret = -1;
2751                         reply_code = LTTNG_ERR_INVALID;
2752                         goto end;
2753                 }
2754
2755                 chunk_status = lttng_trace_chunk_override_name(
2756                                 chunk, chunk_name_view.data);
2757                 switch (chunk_status) {
2758                 case LTTNG_TRACE_CHUNK_STATUS_OK:
2759                         break;
2760                 case LTTNG_TRACE_CHUNK_STATUS_INVALID_ARGUMENT:
2761                         ERR("Failed to set the name of new trace chunk in trace chunk creation command (invalid name)");
2762                         reply_code = LTTNG_ERR_INVALID;
2763                         ret = -1;
2764                         goto end;
2765                 default:
2766                         ERR("Failed to set the name of new trace chunk in trace chunk creation command (unknown error)");
2767                         reply_code = LTTNG_ERR_UNK;
2768                         ret = -1;
2769                         goto end;
2770                 }
2771         }
2772
2773         chunk_status = lttng_trace_chunk_set_credentials_current_user(chunk);
2774         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2775                 reply_code = LTTNG_ERR_UNK;
2776                 ret = -1;
2777                 goto end;
2778         }
2779
2780         LTTNG_ASSERT(conn->session->output_directory);
2781         chunk_status = lttng_trace_chunk_set_as_owner(chunk,
2782                         conn->session->output_directory);
2783         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2784                 reply_code = LTTNG_ERR_UNK;
2785                 ret = -1;
2786                 goto end;
2787         }
2788
2789         published_chunk = sessiond_trace_chunk_registry_publish_chunk(
2790                         sessiond_trace_chunk_registry,
2791                         conn->session->sessiond_uuid,
2792                         conn->session->id,
2793                         chunk);
2794         if (!published_chunk) {
2795                 char uuid_str[LTTNG_UUID_STR_LEN];
2796
2797                 lttng_uuid_to_str(conn->session->sessiond_uuid, uuid_str);
2798                 ERR("Failed to publish chunk: sessiond_uuid = %s, session_id = %" PRIu64 ", chunk_id = %" PRIu64,
2799                                 uuid_str,
2800                                 conn->session->id,
2801                                 msg->chunk_id);
2802                 ret = -1;
2803                 reply_code = LTTNG_ERR_NOMEM;
2804                 goto end;
2805         }
2806
2807         pthread_mutex_lock(&conn->session->lock);
2808         if (conn->session->pending_closure_trace_chunk) {
2809                 /*
2810                  * Invalid; this means a second create_trace_chunk command was
2811                  * received before a close_trace_chunk.
2812                  */
2813                 ERR("Invalid trace chunk close command received; a trace chunk is already waiting for a trace chunk close command");
2814                 reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2815                 ret = -1;
2816                 goto end_unlock_session;
2817         }
2818         conn->session->pending_closure_trace_chunk =
2819                         conn->session->current_trace_chunk;
2820         conn->session->current_trace_chunk = published_chunk;
2821         published_chunk = NULL;
2822         if (!conn->session->pending_closure_trace_chunk) {
2823                 session->ongoing_rotation = false;
2824         }
2825 end_unlock_session:
2826         pthread_mutex_unlock(&conn->session->lock);
2827 end:
2828         reply.ret_code = htobe32((uint32_t) reply_code);
2829         send_ret = conn->sock->ops->sendmsg(conn->sock,
2830                         &reply,
2831                         sizeof(struct lttcomm_relayd_generic_reply),
2832                         0);
2833         if (send_ret < (ssize_t) sizeof(reply)) {
2834                 ERR("Failed to send \"create trace chunk\" command reply (ret = %zd)",
2835                                 send_ret);
2836                 ret = -1;
2837         }
2838 end_no_reply:
2839         lttng_trace_chunk_put(chunk);
2840         lttng_trace_chunk_put(published_chunk);
2841         return ret;
2842 }
2843
2844 /*
2845  * relay_close_trace_chunk: close a trace chunk
2846  */
2847 static int relay_close_trace_chunk(const struct lttcomm_relayd_hdr *recv_hdr,
2848                 struct relay_connection *conn,
2849                 const struct lttng_buffer_view *payload)
2850 {
2851         int ret = 0, buf_ret;
2852         ssize_t send_ret;
2853         struct relay_session *session = conn->session;
2854         struct lttcomm_relayd_close_trace_chunk *msg;
2855         struct lttcomm_relayd_close_trace_chunk_reply reply = {};
2856         struct lttng_buffer_view header_view;
2857         struct lttng_trace_chunk *chunk = NULL;
2858         enum lttng_error_code reply_code = LTTNG_OK;
2859         enum lttng_trace_chunk_status chunk_status;
2860         uint64_t chunk_id;
2861         LTTNG_OPTIONAL(enum lttng_trace_chunk_command_type) close_command = {};
2862         time_t close_timestamp;
2863         char closed_trace_chunk_path[LTTNG_PATH_MAX];
2864         size_t path_length = 0;
2865         const char *chunk_name = NULL;
2866         struct lttng_dynamic_buffer reply_payload;
2867         const char *new_path;
2868
2869         lttng_dynamic_buffer_init(&reply_payload);
2870
2871         if (!session || !conn->version_check_done) {
2872                 ERR("Trying to close a trace chunk before version check");
2873                 ret = -1;
2874                 goto end_no_reply;
2875         }
2876
2877         if (session->major == 2 && session->minor < 11) {
2878                 ERR("Chunk close command is unsupported before 2.11");
2879                 ret = -1;
2880                 goto end_no_reply;
2881         }
2882
2883         header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
2884         if (!lttng_buffer_view_is_valid(&header_view)) {
2885                 ERR("Failed to receive payload of chunk close command");
2886                 ret = -1;
2887                 goto end_no_reply;
2888         }
2889
2890         /* Convert to host endianness. */
2891         msg = (typeof(msg)) header_view.data;
2892         chunk_id = be64toh(msg->chunk_id);
2893         close_timestamp = (time_t) be64toh(msg->close_timestamp);
2894         close_command = (typeof(close_command)){
2895                 .value = be32toh(msg->close_command.value),
2896                 .is_set = msg->close_command.is_set,
2897         };
2898
2899         chunk = sessiond_trace_chunk_registry_get_chunk(
2900                         sessiond_trace_chunk_registry,
2901                         conn->session->sessiond_uuid,
2902                         conn->session->id,
2903                         chunk_id);
2904         if (!chunk) {
2905                 char uuid_str[LTTNG_UUID_STR_LEN];
2906
2907                 lttng_uuid_to_str(conn->session->sessiond_uuid, uuid_str);
2908                 ERR("Failed to find chunk to close: sessiond_uuid = %s, session_id = %" PRIu64 ", chunk_id = %" PRIu64,
2909                                 uuid_str,
2910                                 conn->session->id,
2911                                 msg->chunk_id);
2912                 ret = -1;
2913                 reply_code = LTTNG_ERR_NOMEM;
2914                 goto end;
2915         }
2916
2917         pthread_mutex_lock(&session->lock);
2918         if (close_command.is_set &&
2919                         close_command.value == LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE) {
2920                 /*
2921                  * Clear command. It is a protocol error to ask for a
2922                  * clear on a relay which does not allow it. Querying
2923                  * the configuration allows figuring out whether
2924                  * clearing is allowed before doing the clear.
2925                  */
2926                 if (!opt_allow_clear) {
2927                         ret = -1;
2928                         reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2929                         goto end_unlock_session;
2930                 }
2931         }
2932         if (session->pending_closure_trace_chunk &&
2933                         session->pending_closure_trace_chunk != chunk) {
2934                 ERR("Trace chunk close command for session \"%s\" does not target the trace chunk pending closure",
2935                                 session->session_name);
2936                 reply_code = LTTNG_ERR_INVALID_PROTOCOL;
2937                 ret = -1;
2938                 goto end_unlock_session;
2939         }
2940
2941         if (session->current_trace_chunk && session->current_trace_chunk != chunk &&
2942                         !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
2943                 if (close_command.is_set &&
2944                                 close_command.value == LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE &&
2945                                 !session->has_rotated) {
2946                         /* New chunk stays in session output directory. */
2947                         new_path = "";
2948                 } else {
2949                         /* Use chunk name for new chunk. */
2950                         new_path = NULL;
2951                 }
2952                 /* Rename new chunk path. */
2953                 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
2954                                 new_path);
2955                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2956                         ret = -1;
2957                         goto end_unlock_session;
2958                 }
2959                 session->ongoing_rotation = false;
2960         }
2961         if ((!close_command.is_set ||
2962                         close_command.value == LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION) &&
2963                         !lttng_trace_chunk_get_name_overridden(chunk)) {
2964                 const char *old_path;
2965
2966                 if (!session->has_rotated) {
2967                         old_path = "";
2968                 } else {
2969                         old_path = NULL;
2970                 }
2971                 /* We need to move back the .tmp_old_chunk to its rightful place. */
2972                 chunk_status = lttng_trace_chunk_rename_path(chunk, old_path);
2973                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2974                         ret = -1;
2975                         goto end_unlock_session;
2976                 }
2977         }
2978         chunk_status = lttng_trace_chunk_set_close_timestamp(
2979                         chunk, close_timestamp);
2980         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2981                 ERR("Failed to set trace chunk close timestamp");
2982                 ret = -1;
2983                 reply_code = LTTNG_ERR_UNK;
2984                 goto end_unlock_session;
2985         }
2986
2987         if (close_command.is_set) {
2988                 chunk_status = lttng_trace_chunk_set_close_command(
2989                                 chunk, close_command.value);
2990                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2991                         ret = -1;
2992                         reply_code = LTTNG_ERR_INVALID;
2993                         goto end_unlock_session;
2994                 }
2995         }
2996         chunk_status = lttng_trace_chunk_get_name(chunk, &chunk_name, NULL);
2997         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
2998                 ERR("Failed to get chunk name");
2999                 ret = -1;
3000                 reply_code = LTTNG_ERR_UNK;
3001                 goto end_unlock_session;
3002         }
3003         if (!session->has_rotated && !session->snapshot) {
3004                 ret = lttng_strncpy(closed_trace_chunk_path,
3005                                 session->output_path,
3006                                 sizeof(closed_trace_chunk_path));
3007                 if (ret) {
3008                         ERR("Failed to send trace chunk path: path length of %zu bytes exceeds the maximal allowed length of %zu bytes",
3009                                         strlen(session->output_path),
3010                                         sizeof(closed_trace_chunk_path));
3011                         reply_code = LTTNG_ERR_NOMEM;
3012                         ret = -1;
3013                         goto end_unlock_session;
3014                 }
3015         } else {
3016                 if (session->snapshot) {
3017                         ret = snprintf(closed_trace_chunk_path,
3018                                         sizeof(closed_trace_chunk_path),
3019                                         "%s/%s", session->output_path,
3020                                         chunk_name);
3021                 } else {
3022                         ret = snprintf(closed_trace_chunk_path,
3023                                         sizeof(closed_trace_chunk_path),
3024                                         "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY
3025                                         "/%s",
3026                                         session->output_path, chunk_name);
3027                 }
3028                 if (ret < 0 || ret == sizeof(closed_trace_chunk_path)) {
3029                         ERR("Failed to format closed trace chunk resulting path");
3030                         reply_code = ret < 0 ? LTTNG_ERR_UNK : LTTNG_ERR_NOMEM;
3031                         ret = -1;
3032                         goto end_unlock_session;
3033                 }
3034         }
3035         if (close_command.is_set &&
3036                         close_command.value == LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED) {
3037                 session->has_rotated = true;
3038         }
3039         DBG("Reply chunk path on close: %s", closed_trace_chunk_path);
3040         path_length = strlen(closed_trace_chunk_path) + 1;
3041         if (path_length > UINT32_MAX) {
3042                 ERR("Closed trace chunk path exceeds the maximal length allowed by the protocol");
3043                 ret = -1;
3044                 reply_code = LTTNG_ERR_INVALID_PROTOCOL;
3045                 goto end_unlock_session;
3046         }
3047
3048         if (session->current_trace_chunk == chunk) {
3049                 /*
3050                  * After a trace chunk close command, no new streams
3051                  * referencing the chunk may be created. Hence, on the
3052                  * event that no new trace chunk have been created for
3053                  * the session, the reference to the current trace chunk
3054                  * is released in order to allow it to be reclaimed when
3055                  * the last stream releases its reference to it.
3056                  */
3057                 lttng_trace_chunk_put(session->current_trace_chunk);
3058                 session->current_trace_chunk = NULL;
3059         }
3060         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
3061         session->pending_closure_trace_chunk = NULL;
3062 end_unlock_session:
3063         pthread_mutex_unlock(&session->lock);
3064
3065 end:
3066         reply.generic.ret_code = htobe32((uint32_t) reply_code);
3067         reply.path_length = htobe32((uint32_t) path_length);
3068         buf_ret = lttng_dynamic_buffer_append(
3069                         &reply_payload, &reply, sizeof(reply));
3070         if (buf_ret) {
3071                 ERR("Failed to append \"close trace chunk\" command reply header to payload buffer");
3072                 goto end_no_reply;
3073         }
3074
3075         if (reply_code == LTTNG_OK) {
3076                 buf_ret = lttng_dynamic_buffer_append(&reply_payload,
3077                                 closed_trace_chunk_path, path_length);
3078                 if (buf_ret) {
3079                         ERR("Failed to append \"close trace chunk\" command reply path to payload buffer");
3080                         goto end_no_reply;
3081                 }
3082         }
3083
3084         send_ret = conn->sock->ops->sendmsg(conn->sock,
3085                         reply_payload.data,
3086                         reply_payload.size,
3087                         0);
3088         if (send_ret < reply_payload.size) {
3089                 ERR("Failed to send \"close trace chunk\" command reply of %zu bytes (ret = %zd)",
3090                                 reply_payload.size, send_ret);
3091                 ret = -1;
3092                 goto end_no_reply;
3093         }
3094 end_no_reply:
3095         lttng_trace_chunk_put(chunk);
3096         lttng_dynamic_buffer_reset(&reply_payload);
3097         return ret;
3098 }
3099
3100 /*
3101  * relay_trace_chunk_exists: check if a trace chunk exists
3102  */
3103 static int relay_trace_chunk_exists(const struct lttcomm_relayd_hdr *recv_hdr,
3104                 struct relay_connection *conn,
3105                 const struct lttng_buffer_view *payload)
3106 {
3107         int ret = 0;
3108         ssize_t send_ret;
3109         struct relay_session *session = conn->session;
3110         struct lttcomm_relayd_trace_chunk_exists *msg;
3111         struct lttcomm_relayd_trace_chunk_exists_reply reply = {};
3112         struct lttng_buffer_view header_view;
3113         uint64_t chunk_id;
3114         bool chunk_exists;
3115
3116         if (!session || !conn->version_check_done) {
3117                 ERR("Trying to check for the existance of a trace chunk before version check");
3118                 ret = -1;
3119                 goto end_no_reply;
3120         }
3121
3122         if (session->major == 2 && session->minor < 11) {
3123                 ERR("Chunk exists command is unsupported before 2.11");
3124                 ret = -1;
3125                 goto end_no_reply;
3126         }
3127
3128         header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
3129         if (!lttng_buffer_view_is_valid(&header_view)) {
3130                 ERR("Failed to receive payload of chunk exists command");
3131                 ret = -1;
3132                 goto end_no_reply;
3133         }
3134
3135         /* Convert to host endianness. */
3136         msg = (typeof(msg)) header_view.data;
3137         chunk_id = be64toh(msg->chunk_id);
3138
3139         ret = sessiond_trace_chunk_registry_chunk_exists(
3140                         sessiond_trace_chunk_registry,
3141                         conn->session->sessiond_uuid,
3142                         conn->session->id,
3143                         chunk_id, &chunk_exists);
3144         /*
3145          * If ret is not 0, send the reply and report the error to the caller.
3146          * It is a protocol (or internal) error and the session/connection
3147          * should be torn down.
3148          */
3149         reply = (typeof(reply)){
3150                 .generic.ret_code = htobe32((uint32_t)
3151                         (ret == 0 ? LTTNG_OK : LTTNG_ERR_INVALID_PROTOCOL)),
3152                 .trace_chunk_exists = ret == 0 ? chunk_exists : 0,
3153         };
3154         send_ret = conn->sock->ops->sendmsg(
3155                         conn->sock, &reply, sizeof(reply), 0);
3156         if (send_ret < (ssize_t) sizeof(reply)) {
3157                 ERR("Failed to send \"create trace chunk\" command reply (ret = %zd)",
3158                                 send_ret);
3159                 ret = -1;
3160         }
3161 end_no_reply:
3162         return ret;
3163 }
3164
3165 /*
3166  * relay_get_configuration: query whether feature is available
3167  */
3168 static int relay_get_configuration(const struct lttcomm_relayd_hdr *recv_hdr,
3169                 struct relay_connection *conn,
3170                 const struct lttng_buffer_view *payload)
3171 {
3172         int ret = 0;
3173         ssize_t send_ret;
3174         struct lttcomm_relayd_get_configuration *msg;
3175         struct lttcomm_relayd_get_configuration_reply reply = {};
3176         struct lttng_buffer_view header_view;
3177         uint64_t query_flags = 0;
3178         uint64_t result_flags = 0;
3179
3180         header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
3181         if (!lttng_buffer_view_is_valid(&header_view)) {
3182                 ERR("Failed to receive payload of chunk close command");
3183                 ret = -1;
3184                 goto end_no_reply;
3185         }
3186
3187         /* Convert to host endianness. */
3188         msg = (typeof(msg)) header_view.data;
3189         query_flags = be64toh(msg->query_flags);
3190
3191         if (query_flags) {
3192                 ret = LTTNG_ERR_INVALID_PROTOCOL;
3193                 goto reply;
3194         }
3195         if (opt_allow_clear) {
3196                 result_flags |= LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED;
3197         }
3198         ret = 0;
3199 reply:
3200         reply = (typeof(reply)){
3201                 .generic.ret_code = htobe32((uint32_t)
3202                         (ret == 0 ? LTTNG_OK : LTTNG_ERR_INVALID_PROTOCOL)),
3203                 .relayd_configuration_flags = htobe64(result_flags),
3204         };
3205         send_ret = conn->sock->ops->sendmsg(
3206                         conn->sock, &reply, sizeof(reply), 0);
3207         if (send_ret < (ssize_t) sizeof(reply)) {
3208                 ERR("Failed to send \"get configuration\" command reply (ret = %zd)",
3209                                 send_ret);
3210                 ret = -1;
3211         }
3212 end_no_reply:
3213         return ret;
3214 }
3215
3216 #define DBG_CMD(cmd_name, conn) \
3217                 DBG3("Processing \"%s\" command for socket %i", cmd_name, conn->sock->fd);
3218
3219 static int relay_process_control_command(struct relay_connection *conn,
3220                 const struct lttcomm_relayd_hdr *header,
3221                 const struct lttng_buffer_view *payload)
3222 {
3223         int ret = 0;
3224
3225         switch (header->cmd) {
3226         case RELAYD_CREATE_SESSION:
3227                 DBG_CMD("RELAYD_CREATE_SESSION", conn);
3228                 ret = relay_create_session(header, conn, payload);
3229                 break;
3230         case RELAYD_ADD_STREAM:
3231                 DBG_CMD("RELAYD_ADD_STREAM", conn);
3232                 ret = relay_add_stream(header, conn, payload);
3233                 break;
3234         case RELAYD_START_DATA:
3235                 DBG_CMD("RELAYD_START_DATA", conn);
3236                 ret = relay_start(header, conn, payload);
3237                 break;
3238         case RELAYD_SEND_METADATA:
3239                 DBG_CMD("RELAYD_SEND_METADATA", conn);
3240                 ret = relay_recv_metadata(header, conn, payload);
3241                 break;
3242         case RELAYD_VERSION:
3243                 DBG_CMD("RELAYD_VERSION", conn);
3244                 ret = relay_send_version(header, conn, payload);
3245                 break;
3246         case RELAYD_CLOSE_STREAM:
3247                 DBG_CMD("RELAYD_CLOSE_STREAM", conn);
3248                 ret = relay_close_stream(header, conn, payload);
3249                 break;
3250         case RELAYD_DATA_PENDING:
3251                 DBG_CMD("RELAYD_DATA_PENDING", conn);
3252                 ret = relay_data_pending(header, conn, payload);
3253                 break;
3254         case RELAYD_QUIESCENT_CONTROL:
3255                 DBG_CMD("RELAYD_QUIESCENT_CONTROL", conn);
3256                 ret = relay_quiescent_control(header, conn, payload);
3257                 break;
3258         case RELAYD_BEGIN_DATA_PENDING:
3259                 DBG_CMD("RELAYD_BEGIN_DATA_PENDING", conn);
3260                 ret = relay_begin_data_pending(header, conn, payload);
3261                 break;
3262         case RELAYD_END_DATA_PENDING:
3263                 DBG_CMD("RELAYD_END_DATA_PENDING", conn);
3264                 ret = relay_end_data_pending(header, conn, payload);
3265                 break;
3266         case RELAYD_SEND_INDEX:
3267                 DBG_CMD("RELAYD_SEND_INDEX", conn);
3268                 ret = relay_recv_index(header, conn, payload);
3269                 break;
3270         case RELAYD_STREAMS_SENT:
3271                 DBG_CMD("RELAYD_STREAMS_SENT", conn);
3272                 ret = relay_streams_sent(header, conn, payload);
3273                 break;
3274         case RELAYD_RESET_METADATA:
3275                 DBG_CMD("RELAYD_RESET_METADATA", conn);
3276                 ret = relay_reset_metadata(header, conn, payload);
3277                 break;
3278         case RELAYD_ROTATE_STREAMS:
3279                 DBG_CMD("RELAYD_ROTATE_STREAMS", conn);
3280                 ret = relay_rotate_session_streams(header, conn, payload);
3281                 break;
3282         case RELAYD_CREATE_TRACE_CHUNK:
3283                 DBG_CMD("RELAYD_CREATE_TRACE_CHUNK", conn);
3284                 ret = relay_create_trace_chunk(header, conn, payload);
3285                 break;
3286         case RELAYD_CLOSE_TRACE_CHUNK:
3287                 DBG_CMD("RELAYD_CLOSE_TRACE_CHUNK", conn);
3288                 ret = relay_close_trace_chunk(header, conn, payload);
3289                 break;
3290         case RELAYD_TRACE_CHUNK_EXISTS:
3291                 DBG_CMD("RELAYD_TRACE_CHUNK_EXISTS", conn);
3292                 ret = relay_trace_chunk_exists(header, conn, payload);
3293                 break;
3294         case RELAYD_GET_CONFIGURATION:
3295                 DBG_CMD("RELAYD_GET_CONFIGURATION", conn);
3296                 ret = relay_get_configuration(header, conn, payload);
3297                 break;
3298         case RELAYD_UPDATE_SYNC_INFO:
3299         default:
3300                 ERR("Received unknown command (%u)", header->cmd);
3301                 relay_unknown_command(conn);
3302                 ret = -1;
3303                 goto end;
3304         }
3305
3306 end:
3307         return ret;
3308 }
3309
3310 static enum relay_connection_status relay_process_control_receive_payload(
3311                 struct relay_connection *conn)
3312 {
3313         int ret = 0;
3314         enum relay_connection_status status = RELAY_CONNECTION_STATUS_OK;
3315         struct lttng_dynamic_buffer *reception_buffer =
3316                         &conn->protocol.ctrl.reception_buffer;
3317         struct ctrl_connection_state_receive_payload *state =
3318                         &conn->protocol.ctrl.state.receive_payload;
3319         struct lttng_buffer_view payload_view;
3320
3321         if (state->left_to_receive == 0) {
3322                 /* Short-circuit for payload-less commands. */
3323                 goto reception_complete;
3324         }
3325
3326         ret = conn->sock->ops->recvmsg(conn->sock,
3327                         reception_buffer->data + state->received,
3328                         state->left_to_receive, MSG_DONTWAIT);
3329         if (ret < 0) {
3330                 if (errno != EAGAIN && errno != EWOULDBLOCK) {
3331                         PERROR("Unable to receive command payload on sock %d",
3332                                         conn->sock->fd);
3333                         status = RELAY_CONNECTION_STATUS_ERROR;
3334                 }
3335                 goto end;
3336         } else if (ret == 0) {
3337                 DBG("Socket %d performed an orderly shutdown (received EOF)", conn->sock->fd);
3338                 status = RELAY_CONNECTION_STATUS_CLOSED;
3339                 goto end;
3340         }
3341
3342         LTTNG_ASSERT(ret > 0);
3343         LTTNG_ASSERT(ret <= state->left_to_receive);
3344
3345         state->left_to_receive -= ret;
3346         state->received += ret;
3347
3348         if (state->left_to_receive > 0) {
3349                 /*
3350                  * Can't transition to the protocol's next state, wait to
3351                  * receive the rest of the header.
3352                  */
3353                 DBG3("Partial reception of control connection protocol payload (received %" PRIu64 " bytes, %" PRIu64 " bytes left to receive, fd = %i)",
3354                                 state->received, state->left_to_receive,
3355                                 conn->sock->fd);
3356                 goto end;
3357         }
3358
3359 reception_complete:
3360         DBG("Done receiving control command payload: fd = %i, payload size = %" PRIu64 " bytes",
3361                         conn->sock->fd, state->received);
3362         /*
3363          * The payload required to process the command has been received.
3364          * A view to the reception buffer is forwarded to the various
3365          * commands and the state of the control is reset on success.
3366          *
3367          * Commands are responsible for sending their reply to the peer.
3368          */
3369         payload_view = lttng_buffer_view_from_dynamic_buffer(reception_buffer,
3370                         0, -1);
3371         ret = relay_process_control_command(conn,
3372                         &state->header, &payload_view);
3373         if (ret < 0) {
3374                 status = RELAY_CONNECTION_STATUS_ERROR;
3375                 goto end;
3376         }
3377
3378         ret = connection_reset_protocol_state(conn);
3379         if (ret) {
3380                 status = RELAY_CONNECTION_STATUS_ERROR;
3381         }
3382 end:
3383         return status;
3384 }
3385
3386 static enum relay_connection_status relay_process_control_receive_header(
3387                 struct relay_connection *conn)
3388 {
3389         int ret = 0;
3390         enum relay_connection_status status = RELAY_CONNECTION_STATUS_OK;
3391         struct lttcomm_relayd_hdr header;
3392         struct lttng_dynamic_buffer *reception_buffer =
3393                         &conn->protocol.ctrl.reception_buffer;
3394         struct ctrl_connection_state_receive_header *state =
3395                         &conn->protocol.ctrl.state.receive_header;
3396
3397         LTTNG_ASSERT(state->left_to_receive != 0);
3398
3399         ret = conn->sock->ops->recvmsg(conn->sock,
3400                         reception_buffer->data + state->received,
3401                         state->left_to_receive, MSG_DONTWAIT);
3402         if (ret < 0) {
3403                 if (errno != EAGAIN && errno != EWOULDBLOCK) {
3404                         PERROR("Unable to receive control command header on sock %d",
3405                                         conn->sock->fd);
3406                         status = RELAY_CONNECTION_STATUS_ERROR;
3407                 }
3408                 goto end;
3409         } else if (ret == 0) {
3410                 DBG("Socket %d performed an orderly shutdown (received EOF)", conn->sock->fd);
3411                 status = RELAY_CONNECTION_STATUS_CLOSED;
3412                 goto end;
3413         }
3414
3415         LTTNG_ASSERT(ret > 0);
3416         LTTNG_ASSERT(ret <= state->left_to_receive);
3417
3418         state->left_to_receive -= ret;
3419         state->received += ret;
3420
3421         if (state->left_to_receive > 0) {
3422                 /*
3423                  * Can't transition to the protocol's next state, wait to
3424                  * receive the rest of the header.
3425                  */
3426                 DBG3("Partial reception of control connection protocol header (received %" PRIu64 " bytes, %" PRIu64 " bytes left to receive, fd = %i)",
3427                                 state->received, state->left_to_receive,
3428                                 conn->sock->fd);
3429                 goto end;
3430         }
3431
3432         /* Transition to next state: receiving the command's payload. */
3433         conn->protocol.ctrl.state_id =
3434                         CTRL_CONNECTION_STATE_RECEIVE_PAYLOAD;
3435         memcpy(&header, reception_buffer->data, sizeof(header));
3436         header.circuit_id = be64toh(header.circuit_id);
3437         header.data_size = be64toh(header.data_size);
3438         header.cmd = be32toh(header.cmd);
3439         header.cmd_version = be32toh(header.cmd_version);
3440         memcpy(&conn->protocol.ctrl.state.receive_payload.header,
3441                         &header, sizeof(header));
3442
3443         DBG("Done receiving control command header: fd = %i, cmd = %" PRIu32 ", cmd_version = %" PRIu32 ", payload size = %" PRIu64 " bytes",
3444                         conn->sock->fd, header.cmd, header.cmd_version,
3445                         header.data_size);
3446
3447         if (header.data_size > DEFAULT_NETWORK_RELAYD_CTRL_MAX_PAYLOAD_SIZE) {
3448                 ERR("Command header indicates a payload (%" PRIu64 " bytes) that exceeds the maximal payload size allowed on a control connection.",
3449                                 header.data_size);
3450                 status = RELAY_CONNECTION_STATUS_ERROR;
3451                 goto end;
3452         }
3453
3454         conn->protocol.ctrl.state.receive_payload.left_to_receive =
3455                         header.data_size;
3456         conn->protocol.ctrl.state.receive_payload.received = 0;
3457         ret = lttng_dynamic_buffer_set_size(reception_buffer,
3458                         header.data_size);
3459         if (ret) {
3460                 status = RELAY_CONNECTION_STATUS_ERROR;
3461                 goto end;
3462         }
3463
3464         if (header.data_size == 0) {
3465                 /*
3466                  * Manually invoke the next state as the poll loop
3467                  * will not wake-up to allow us to proceed further.
3468                  */
3469                 status = relay_process_control_receive_payload(conn);
3470         }
3471 end:
3472         return status;
3473 }
3474
3475 /*
3476  * Process the commands received on the control socket
3477  */
3478 static enum relay_connection_status relay_process_control(
3479                 struct relay_connection *conn)
3480 {
3481         enum relay_connection_status status;
3482
3483         switch (conn->protocol.ctrl.state_id) {
3484         case CTRL_CONNECTION_STATE_RECEIVE_HEADER:
3485                 status = relay_process_control_receive_header(conn);
3486                 break;
3487         case CTRL_CONNECTION_STATE_RECEIVE_PAYLOAD:
3488                 status = relay_process_control_receive_payload(conn);
3489                 break;
3490         default:
3491                 ERR("Unknown control connection protocol state encountered.");
3492                 abort();
3493         }
3494
3495         return status;
3496 }
3497
3498 static enum relay_connection_status relay_process_data_receive_header(
3499                 struct relay_connection *conn)
3500 {
3501         int ret;
3502         enum relay_connection_status status = RELAY_CONNECTION_STATUS_OK;
3503         struct data_connection_state_receive_header *state =
3504                         &conn->protocol.data.state.receive_header;
3505         struct lttcomm_relayd_data_hdr header;
3506         struct relay_stream *stream;
3507
3508         LTTNG_ASSERT(state->left_to_receive != 0);
3509
3510         ret = conn->sock->ops->recvmsg(conn->sock,
3511                         state->header_reception_buffer + state->received,
3512                         state->left_to_receive, MSG_DONTWAIT);
3513         if (ret < 0) {
3514                 if (errno != EAGAIN && errno != EWOULDBLOCK) {
3515                         PERROR("Unable to receive data header on sock %d", conn->sock->fd);
3516                         status = RELAY_CONNECTION_STATUS_ERROR;
3517                 }
3518                 goto end;
3519         } else if (ret == 0) {
3520                 /* Orderly shutdown. Not necessary to print an error. */
3521                 DBG("Socket %d performed an orderly shutdown (received EOF)", conn->sock->fd);
3522                 status = RELAY_CONNECTION_STATUS_CLOSED;
3523                 goto end;
3524         }
3525
3526         LTTNG_ASSERT(ret > 0);
3527         LTTNG_ASSERT(ret <= state->left_to_receive);
3528
3529         state->left_to_receive -= ret;
3530         state->received += ret;
3531
3532         if (state->left_to_receive > 0) {
3533                 /*
3534                  * Can't transition to the protocol's next state, wait to
3535                  * receive the rest of the header.
3536                  */
3537                 DBG3("Partial reception of data connection header (received %" PRIu64 " bytes, %" PRIu64 " bytes left to receive, fd = %i)",
3538                                 state->received, state->left_to_receive,
3539                                 conn->sock->fd);
3540                 goto end;
3541         }
3542
3543         /* Transition to next state: receiving the payload. */
3544         conn->protocol.data.state_id = DATA_CONNECTION_STATE_RECEIVE_PAYLOAD;
3545
3546         memcpy(&header, state->header_reception_buffer, sizeof(header));
3547         header.circuit_id = be64toh(header.circuit_id);
3548         header.stream_id = be64toh(header.stream_id);
3549         header.data_size = be32toh(header.data_size);
3550         header.net_seq_num = be64toh(header.net_seq_num);
3551         header.padding_size = be32toh(header.padding_size);
3552         memcpy(&conn->protocol.data.state.receive_payload.header, &header, sizeof(header));
3553
3554         conn->protocol.data.state.receive_payload.left_to_receive =
3555                         header.data_size;
3556         conn->protocol.data.state.receive_payload.received = 0;
3557         conn->protocol.data.state.receive_payload.rotate_index = false;
3558
3559         DBG("Received data connection header on fd %i: circuit_id = %" PRIu64 ", stream_id = %" PRIu64 ", data_size = %" PRIu32 ", net_seq_num = %" PRIu64 ", padding_size = %" PRIu32,
3560                         conn->sock->fd, header.circuit_id,
3561                         header.stream_id, header.data_size,
3562                         header.net_seq_num, header.padding_size);
3563
3564         stream = stream_get_by_id(header.stream_id);
3565         if (!stream) {
3566                 DBG("relay_process_data_receive_payload: Cannot find stream %" PRIu64,
3567                                 header.stream_id);
3568                 /* Protocol error. */
3569                 status = RELAY_CONNECTION_STATUS_ERROR;
3570                 goto end;
3571         }
3572
3573         pthread_mutex_lock(&stream->lock);
3574         /* Prepare stream for the reception of a new packet. */
3575         ret = stream_init_packet(stream, header.data_size,
3576                         &conn->protocol.data.state.receive_payload.rotate_index);
3577         pthread_mutex_unlock(&stream->lock);
3578         if (ret) {
3579                 ERR("Failed to rotate stream output file");
3580                 status = RELAY_CONNECTION_STATUS_ERROR;
3581                 goto end_stream_unlock;
3582         }
3583
3584 end_stream_unlock:
3585         stream_put(stream);
3586 end:
3587         return status;
3588 }
3589
3590 static enum relay_connection_status relay_process_data_receive_payload(
3591                 struct relay_connection *conn)
3592 {
3593         int ret;
3594         enum relay_connection_status status = RELAY_CONNECTION_STATUS_OK;
3595         struct relay_stream *stream;
3596         struct data_connection_state_receive_payload *state =
3597                         &conn->protocol.data.state.receive_payload;
3598         const size_t chunk_size = RECV_DATA_BUFFER_SIZE;
3599         char data_buffer[chunk_size];
3600         bool partial_recv = false;
3601         bool new_stream = false, close_requested = false, index_flushed = false;
3602         uint64_t left_to_receive = state->left_to_receive;
3603         struct relay_session *session;
3604
3605         DBG3("Receiving data for stream id %" PRIu64 " seqnum %" PRIu64 ", %" PRIu64" bytes received, %" PRIu64 " bytes left to receive",
3606                         state->header.stream_id, state->header.net_seq_num,
3607                         state->received, left_to_receive);
3608
3609         stream = stream_get_by_id(state->header.stream_id);
3610         if (!stream) {
3611                 /* Protocol error. */
3612                 ERR("relay_process_data_receive_payload: cannot find stream %" PRIu64,
3613                                 state->header.stream_id);
3614                 status = RELAY_CONNECTION_STATUS_ERROR;
3615                 goto end;
3616         }
3617
3618         pthread_mutex_lock(&stream->lock);
3619         session = stream->trace->session;
3620         if (!conn->session) {
3621                 ret = connection_set_session(conn, session);
3622                 if (ret) {
3623                         status = RELAY_CONNECTION_STATUS_ERROR;
3624                         goto end_stream_unlock;
3625                 }
3626         }
3627
3628         /*
3629          * The size of the "chunk" received on any iteration is bounded by:
3630          *   - the data left to receive,
3631          *   - the data immediately available on the socket,
3632          *   - the on-stack data buffer
3633          */
3634         while (left_to_receive > 0 && !partial_recv) {
3635                 size_t recv_size = min(left_to_receive, chunk_size);
3636                 struct lttng_buffer_view packet_chunk;
3637
3638                 ret = conn->sock->ops->recvmsg(conn->sock, data_buffer,
3639                                 recv_size, MSG_DONTWAIT);
3640                 if (ret < 0) {
3641                         if (errno != EAGAIN && errno != EWOULDBLOCK) {
3642                                 PERROR("Socket %d error", conn->sock->fd);
3643                                 status = RELAY_CONNECTION_STATUS_ERROR;
3644                         }
3645                         goto end_stream_unlock;
3646                 } else if (ret == 0) {
3647                         /* No more data ready to be consumed on socket. */
3648                         DBG3("No more data ready for consumption on data socket of stream id %" PRIu64,
3649                                         state->header.stream_id);
3650                         status = RELAY_CONNECTION_STATUS_CLOSED;
3651                         break;
3652                 } else if (ret < (int) recv_size) {
3653                         /*
3654                          * All the data available on the socket has been
3655                          * consumed.
3656                          */
3657                         partial_recv = true;
3658                         recv_size = ret;
3659                 }
3660
3661                 packet_chunk = lttng_buffer_view_init(data_buffer,
3662                                 0, recv_size);
3663                 LTTNG_ASSERT(packet_chunk.data);
3664
3665                 ret = stream_write(stream, &packet_chunk, 0);
3666                 if (ret) {
3667                         ERR("Relay error writing data to file");
3668                         status = RELAY_CONNECTION_STATUS_ERROR;
3669                         goto end_stream_unlock;
3670                 }
3671
3672                 left_to_receive -= recv_size;
3673                 state->received += recv_size;
3674                 state->left_to_receive = left_to_receive;
3675         }
3676
3677         if (state->left_to_receive > 0) {
3678                 /*
3679                  * Did not receive all the data expected, wait for more data to
3680                  * become available on the socket.
3681                  */
3682                 DBG3("Partial receive on data connection of stream id %" PRIu64 ", %" PRIu64 " bytes received, %" PRIu64 " bytes left to receive",
3683                                 state->header.stream_id, state->received,
3684                                 state->left_to_receive);
3685                 goto end_stream_unlock;
3686         }
3687
3688         ret = stream_write(stream, NULL, state->header.padding_size);
3689         if (ret) {
3690                 status = RELAY_CONNECTION_STATUS_ERROR;
3691                 goto end_stream_unlock;
3692         }
3693
3694         if (session_streams_have_index(session)) {
3695                 ret = stream_update_index(stream, state->header.net_seq_num,
3696                                 state->rotate_index, &index_flushed,
3697                                 state->header.data_size + state->header.padding_size);
3698                 if (ret < 0) {
3699                         ERR("Failed to update index: stream %" PRIu64 " net_seq_num %" PRIu64 " ret %d",
3700                                         stream->stream_handle,
3701                                         state->header.net_seq_num, ret);
3702                         status = RELAY_CONNECTION_STATUS_ERROR;
3703                         goto end_stream_unlock;
3704                 }
3705         }
3706
3707         if (stream->prev_data_seq == -1ULL) {
3708                 new_stream = true;
3709         }
3710
3711         ret = stream_complete_packet(stream, state->header.data_size +
3712                         state->header.padding_size, state->header.net_seq_num,
3713                         index_flushed);
3714         if (ret) {
3715                 status = RELAY_CONNECTION_STATUS_ERROR;
3716                 goto end_stream_unlock;
3717         }
3718
3719         /*
3720          * Resetting the protocol state (to RECEIVE_HEADER) will trash the
3721          * contents of *state which are aliased (union) to the same location as
3722          * the new state. Don't use it beyond this point.
3723          */
3724         connection_reset_protocol_state(conn);
3725         state = NULL;
3726
3727 end_stream_unlock:
3728         close_requested = stream->close_requested;
3729         pthread_mutex_unlock(&stream->lock);
3730         if (close_requested && left_to_receive == 0) {
3731                 try_stream_close(stream);
3732         }
3733
3734         if (new_stream) {
3735                 pthread_mutex_lock(&session->lock);
3736                 uatomic_set(&session->new_streams, 1);
3737                 pthread_mutex_unlock(&session->lock);
3738         }
3739
3740         stream_put(stream);
3741 end:
3742         return status;
3743 }
3744
3745 /*
3746  * relay_process_data: Process the data received on the data socket
3747  */
3748 static enum relay_connection_status relay_process_data(
3749                 struct relay_connection *conn)
3750 {
3751         enum relay_connection_status status;
3752
3753         switch (conn->protocol.data.state_id) {
3754         case DATA_CONNECTION_STATE_RECEIVE_HEADER:
3755                 status = relay_process_data_receive_header(conn);
3756                 break;
3757         case DATA_CONNECTION_STATE_RECEIVE_PAYLOAD:
3758                 status = relay_process_data_receive_payload(conn);
3759                 break;
3760         default:
3761                 ERR("Unexpected data connection communication state.");
3762                 abort();
3763         }
3764
3765         return status;
3766 }
3767
3768 static void cleanup_connection_pollfd(struct lttng_poll_event *events, int pollfd)
3769 {
3770         int ret;
3771
3772         (void) lttng_poll_del(events, pollfd);
3773
3774         ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker, &pollfd, 1,
3775                         fd_tracker_util_close_fd, NULL);
3776         if (ret < 0) {
3777                 ERR("Closing pollfd %d", pollfd);
3778         }
3779 }
3780
3781 static void relay_thread_close_connection(struct lttng_poll_event *events,
3782                 int pollfd, struct relay_connection *conn)
3783 {
3784         const char *type_str;
3785
3786         switch (conn->type) {
3787         case RELAY_DATA:
3788                 type_str = "Data";
3789                 break;
3790         case RELAY_CONTROL:
3791                 type_str = "Control";
3792                 break;
3793         case RELAY_VIEWER_COMMAND:
3794                 type_str = "Viewer Command";
3795                 break;
3796         case RELAY_VIEWER_NOTIFICATION:
3797                 type_str = "Viewer Notification";
3798                 break;
3799         default:
3800                 type_str = "Unknown";
3801         }
3802         cleanup_connection_pollfd(events, pollfd);
3803         connection_put(conn);
3804         DBG("%s connection closed with %d", type_str, pollfd);
3805 }
3806
3807 /*
3808  * This thread does the actual work
3809  */
3810 static void *relay_thread_worker(void *data)
3811 {
3812         int ret, err = -1, last_seen_data_fd = -1;
3813         uint32_t nb_fd;
3814         struct lttng_poll_event events;
3815         struct lttng_ht *relay_connections_ht;
3816         struct lttng_ht_iter iter;
3817         struct relay_connection *destroy_conn = NULL;
3818
3819         DBG("[thread] Relay worker started");
3820
3821         rcu_register_thread();
3822
3823         health_register(health_relayd, HEALTH_RELAYD_TYPE_WORKER);
3824
3825         if (testpoint(relayd_thread_worker)) {
3826                 goto error_testpoint;
3827         }
3828
3829         health_code_update();
3830
3831         /* table of connections indexed on socket */
3832         relay_connections_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
3833         if (!relay_connections_ht) {
3834                 goto relay_connections_ht_error;
3835         }
3836
3837         ret = create_named_thread_poll_set(&events, 2, "Worker thread epoll");
3838         if (ret < 0) {
3839                 goto error_poll_create;
3840         }
3841
3842         ret = lttng_poll_add(&events, relay_conn_pipe[0], LPOLLIN | LPOLLRDHUP);
3843         if (ret < 0) {
3844                 goto error;
3845         }
3846
3847 restart:
3848         while (1) {
3849                 int idx = -1, i, seen_control = 0, last_notdel_data_fd = -1;
3850
3851                 health_code_update();
3852
3853                 /* Infinite blocking call, waiting for transmission */
3854                 DBG3("Relayd worker thread polling...");
3855                 health_poll_entry();
3856                 ret = lttng_poll_wait(&events, -1);
3857                 health_poll_exit();
3858                 if (ret < 0) {
3859                         /*
3860                          * Restart interrupted system call.
3861                          */
3862                         if (errno == EINTR) {
3863                                 goto restart;
3864                         }
3865                         goto error;
3866                 }
3867
3868                 nb_fd = ret;
3869
3870                 /*
3871                  * Process control. The control connection is
3872                  * prioritized so we don't starve it with high
3873                  * throughput tracing data on the data connection.
3874                  */
3875                 for (i = 0; i < nb_fd; i++) {
3876                         /* Fetch once the poll data */
3877                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
3878                         int pollfd = LTTNG_POLL_GETFD(&events, i);
3879
3880                         health_code_update();
3881
3882                         /* Thread quit pipe has been closed. Killing thread. */
3883                         ret = check_thread_quit_pipe(pollfd, revents);
3884                         if (ret) {
3885                                 err = 0;
3886                                 goto exit;
3887                         }
3888
3889                         /* Inspect the relay conn pipe for new connection */
3890                         if (pollfd == relay_conn_pipe[0]) {
3891                                 if (revents & LPOLLIN) {
3892                                         struct relay_connection *conn;
3893
3894                                         ret = lttng_read(relay_conn_pipe[0], &conn, sizeof(conn));
3895                                         if (ret < 0) {
3896                                                 goto error;
3897                                         }
3898                                         ret = lttng_poll_add(&events,
3899                                                         conn->sock->fd,
3900                                                         LPOLLIN | LPOLLRDHUP);
3901                                         if (ret) {
3902                                                 ERR("Failed to add new connection file descriptor to poll set");
3903                                                 goto error;
3904                                         }
3905                                         connection_ht_add(relay_connections_ht, conn);
3906                                         DBG("Connection socket %d added", conn->sock->fd);
3907                                 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3908                                         ERR("Relay connection pipe error");
3909                                         goto error;
3910                                 } else {
3911                                         ERR("Unexpected poll events %u for sock %d", revents, pollfd);
3912                                         goto error;
3913                                 }
3914                         } else {
3915                                 struct relay_connection *ctrl_conn;
3916
3917                                 ctrl_conn = connection_get_by_sock(relay_connections_ht, pollfd);
3918                                 /* If not found, there is a synchronization issue. */
3919                                 LTTNG_ASSERT(ctrl_conn);
3920
3921                                 if (ctrl_conn->type == RELAY_DATA) {
3922                                         if (revents & LPOLLIN) {
3923                                                 /*
3924                                                  * Flag the last seen data fd not deleted. It will be
3925                                                  * used as the last seen fd if any fd gets deleted in
3926                                                  * this first loop.
3927                                                  */
3928                                                 last_notdel_data_fd = pollfd;
3929                                         }
3930                                         goto put_ctrl_connection;
3931                                 }
3932                                 LTTNG_ASSERT(ctrl_conn->type == RELAY_CONTROL);
3933
3934                                 if (revents & LPOLLIN) {
3935                                         enum relay_connection_status status;
3936
3937                                         status = relay_process_control(ctrl_conn);
3938                                         if (status != RELAY_CONNECTION_STATUS_OK) {
3939                                                 /*
3940                                                  * On socket error flag the session as aborted to force
3941                                                  * the cleanup of its stream otherwise it can leak
3942                                                  * during the lifetime of the relayd.
3943                                                  *
3944                                                  * This prevents situations in which streams can be
3945                                                  * left opened because an index was received, the
3946                                                  * control connection is closed, and the data
3947                                                  * connection is closed (uncleanly) before the packet's
3948                                                  * data provided.
3949                                                  *
3950                                                  * Since the control connection encountered an error,
3951                                                  * it is okay to be conservative and close the
3952                                                  * session right now as we can't rely on the protocol
3953                                                  * being respected anymore.
3954                                                  */
3955                                                 if (status == RELAY_CONNECTION_STATUS_ERROR) {
3956                                                         session_abort(ctrl_conn->session);
3957                                                 }
3958
3959                                                 /* Clear the connection on error or close. */
3960                                                 relay_thread_close_connection(&events,
3961                                                                 pollfd,
3962                                                                 ctrl_conn);
3963                                         }
3964                                         seen_control = 1;
3965                                 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3966                                         relay_thread_close_connection(&events,
3967                                                         pollfd, ctrl_conn);
3968                                         if (last_seen_data_fd == pollfd) {
3969                                                 last_seen_data_fd = last_notdel_data_fd;
3970                                         }
3971                                 } else {
3972                                         ERR("Unexpected poll events %u for control sock %d",
3973                                                         revents, pollfd);
3974                                         connection_put(ctrl_conn);
3975                                         goto error;
3976                                 }
3977                         put_ctrl_connection:
3978                                 connection_put(ctrl_conn);
3979                         }
3980                 }
3981
3982                 /*
3983                  * The last loop handled a control request, go back to poll to make
3984                  * sure we prioritise the control socket.
3985                  */
3986                 if (seen_control) {
3987                         continue;
3988                 }
3989
3990                 if (last_seen_data_fd >= 0) {
3991                         for (i = 0; i < nb_fd; i++) {
3992                                 int pollfd = LTTNG_POLL_GETFD(&events, i);
3993
3994                                 health_code_update();
3995
3996                                 if (last_seen_data_fd == pollfd) {
3997                                         idx = i;
3998                                         break;
3999                                 }
4000                         }
4001                 }
4002
4003                 /* Process data connection. */
4004                 for (i = idx + 1; i < nb_fd; i++) {
4005                         /* Fetch the poll data. */
4006                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
4007                         int pollfd = LTTNG_POLL_GETFD(&events, i);
4008                         struct relay_connection *data_conn;
4009
4010                         health_code_update();
4011
4012                         if (!revents) {
4013                                 /* No activity for this FD (poll implementation). */
4014                                 continue;
4015                         }
4016
4017                         /* Skip the command pipe. It's handled in the first loop. */
4018                         if (pollfd == relay_conn_pipe[0]) {
4019                                 continue;
4020                         }
4021
4022                         data_conn = connection_get_by_sock(relay_connections_ht, pollfd);
4023                         if (!data_conn) {
4024                                 /* Skip it. Might be removed before. */
4025                                 continue;
4026                         }
4027                         if (data_conn->type == RELAY_CONTROL) {
4028                                 goto put_data_connection;
4029                         }
4030                         LTTNG_ASSERT(data_conn->type == RELAY_DATA);
4031
4032                         if (revents & LPOLLIN) {
4033                                 enum relay_connection_status status;
4034
4035                                 status = relay_process_data(data_conn);
4036                                 /* Connection closed or error. */
4037                                 if (status != RELAY_CONNECTION_STATUS_OK) {
4038                                         /*
4039                                          * On socket error flag the session as aborted to force
4040                                          * the cleanup of its stream otherwise it can leak
4041                                          * during the lifetime of the relayd.
4042                                          *
4043                                          * This prevents situations in which streams can be
4044                                          * left opened because an index was received, the
4045                                          * control connection is closed, and the data
4046                                          * connection is closed (uncleanly) before the packet's
4047                                          * data provided.
4048                                          *
4049                                          * Since the data connection encountered an error,
4050                                          * it is okay to be conservative and close the
4051                                          * session right now as we can't rely on the protocol
4052                                          * being respected anymore.
4053                                          */
4054                                         if (status == RELAY_CONNECTION_STATUS_ERROR) {
4055                                                 session_abort(data_conn->session);
4056                                         }
4057                                         relay_thread_close_connection(&events, pollfd,
4058                                                         data_conn);
4059                                         /*
4060                                          * Every goto restart call sets the last seen fd where
4061                                          * here we don't really care since we gracefully
4062                                          * continue the loop after the connection is deleted.
4063                                          */
4064                                 } else {
4065                                         /* Keep last seen port. */
4066                                         last_seen_data_fd = pollfd;
4067                                         connection_put(data_conn);
4068                                         goto restart;
4069                                 }
4070                         } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
4071                                 relay_thread_close_connection(&events, pollfd,
4072                                                 data_conn);
4073                         } else {
4074                                 ERR("Unknown poll events %u for data sock %d",
4075                                                 revents, pollfd);
4076                         }
4077                 put_data_connection:
4078                         connection_put(data_conn);
4079                 }
4080                 last_seen_data_fd = -1;
4081         }
4082
4083         /* Normal exit, no error */
4084         ret = 0;
4085
4086 exit:
4087 error:
4088         /* Cleanup remaining connection object. */
4089         rcu_read_lock();
4090         cds_lfht_for_each_entry(relay_connections_ht->ht, &iter.iter,
4091                         destroy_conn,
4092                         sock_n.node) {
4093                 health_code_update();
4094
4095                 session_abort(destroy_conn->session);
4096
4097                 /*
4098                  * No need to grab another ref, because we own
4099                  * destroy_conn.
4100                  */
4101                 relay_thread_close_connection(&events, destroy_conn->sock->fd,
4102                                 destroy_conn);
4103         }
4104         rcu_read_unlock();
4105
4106         (void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
4107 error_poll_create:
4108         lttng_ht_destroy(relay_connections_ht);
4109 relay_connections_ht_error:
4110         /* Close relay conn pipes */
4111         (void) fd_tracker_util_pipe_close(the_fd_tracker,
4112                         relay_conn_pipe);
4113         if (err) {
4114                 DBG("Thread exited with error");
4115         }
4116         DBG("Worker thread cleanup complete");
4117 error_testpoint:
4118         if (err) {
4119                 health_error();
4120                 ERR("Health error occurred in %s", __func__);
4121         }
4122         health_unregister(health_relayd);
4123         rcu_unregister_thread();
4124         lttng_relay_stop_threads();
4125         return NULL;
4126 }
4127
4128 /*
4129  * Create the relay command pipe to wake thread_manage_apps.
4130  * Closed in cleanup().
4131  */
4132 static int create_relay_conn_pipe(void)
4133 {
4134         return fd_tracker_util_pipe_open_cloexec(the_fd_tracker,
4135                         "Relayd connection pipe", relay_conn_pipe);
4136 }
4137
4138 static int stdio_open(void *data, int *fds)
4139 {
4140         fds[0] = fileno(stdout);
4141         fds[1] = fileno(stderr);
4142         return 0;
4143 }
4144
4145 static int track_stdio(void)
4146 {
4147         int fds[2];
4148         const char *names[] = { "stdout", "stderr" };
4149
4150         return fd_tracker_open_unsuspendable_fd(the_fd_tracker, fds,
4151                         names, 2, stdio_open, NULL);
4152 }
4153
4154 /*
4155  * main
4156  */
4157 int main(int argc, char **argv)
4158 {
4159         bool thread_is_rcu_registered = false;
4160         int ret = 0, retval = 0;
4161         void *status;
4162         char *unlinked_file_directory_path = NULL, *output_path = NULL;
4163
4164         /* Parse environment variables */
4165         ret = parse_env_options();
4166         if (ret) {
4167                 retval = -1;
4168                 goto exit_options;
4169         }
4170
4171         /*
4172          * Parse arguments.
4173          * Command line arguments overwrite environment.
4174          */
4175         progname = argv[0];
4176         if (set_options(argc, argv)) {
4177                 retval = -1;
4178                 goto exit_options;
4179         }
4180
4181         if (set_signal_handler()) {
4182                 retval = -1;
4183                 goto exit_options;
4184         }
4185
4186         relayd_config_log();
4187
4188         if (opt_print_version) {
4189                 print_version();
4190                 retval = 0;
4191                 goto exit_options;
4192         }
4193
4194         ret = fclose(stdin);
4195         if (ret) {
4196                 PERROR("Failed to close stdin");
4197                 goto exit_options;
4198         }
4199
4200         DBG("Clear command %s", opt_allow_clear ? "allowed" : "disallowed");
4201
4202         /* Try to create directory if -o, --output is specified. */
4203         if (opt_output_path) {
4204                 if (*opt_output_path != '/') {
4205                         ERR("Please specify an absolute path for -o, --output PATH");
4206                         retval = -1;
4207                         goto exit_options;
4208                 }
4209
4210                 ret = utils_mkdir_recursive(opt_output_path, S_IRWXU | S_IRWXG,
4211                                 -1, -1);
4212                 if (ret < 0) {
4213                         ERR("Unable to create %s", opt_output_path);
4214                         retval = -1;
4215                         goto exit_options;
4216                 }
4217         }
4218
4219         /* Daemonize */
4220         if (opt_daemon || opt_background) {
4221                 ret = lttng_daemonize(&child_ppid, &recv_child_signal,
4222                         !opt_background);
4223                 if (ret < 0) {
4224                         retval = -1;
4225                         goto exit_options;
4226                 }
4227         }
4228
4229         if (opt_working_directory) {
4230                 ret = utils_change_working_directory(opt_working_directory);
4231                 if (ret) {
4232                         /* All errors are already logged. */
4233                         goto exit_options;
4234                 }
4235         }
4236
4237         sessiond_trace_chunk_registry = sessiond_trace_chunk_registry_create();
4238         if (!sessiond_trace_chunk_registry) {
4239                 ERR("Failed to initialize session daemon trace chunk registry");
4240                 retval = -1;
4241                 goto exit_options;
4242         }
4243
4244         /*
4245          * The RCU thread registration (and use, through the fd-tracker's
4246          * creation) is done after the daemonization to allow us to not
4247          * deal with liburcu's fork() management as the call RCU needs to
4248          * be restored.
4249          */
4250         rcu_register_thread();
4251         thread_is_rcu_registered = true;
4252
4253         output_path = create_output_path("");
4254         if (!output_path) {
4255                 ERR("Failed to get output path");
4256                 retval = -1;
4257                 goto exit_options;
4258         }
4259         ret = asprintf(&unlinked_file_directory_path, "%s/%s", output_path,
4260                         DEFAULT_UNLINKED_FILES_DIRECTORY);
4261         free(output_path);
4262         if (ret < 0) {
4263                 ERR("Failed to format unlinked file directory path");
4264                 retval = -1;
4265                 goto exit_options;
4266         }
4267         the_fd_tracker = fd_tracker_create(
4268                         unlinked_file_directory_path, lttng_opt_fd_pool_size);
4269         free(unlinked_file_directory_path);
4270         if (!the_fd_tracker) {
4271                 retval = -1;
4272                 goto exit_options;
4273         }
4274
4275         ret = track_stdio();
4276         if (ret) {
4277                 retval = -1;
4278                 goto exit_options;
4279         }
4280
4281         /* Initialize thread health monitoring */
4282         health_relayd = health_app_create(NR_HEALTH_RELAYD_TYPES);
4283         if (!health_relayd) {
4284                 PERROR("health_app_create error");
4285                 retval = -1;
4286                 goto exit_options;
4287         }
4288
4289         /* Create thread quit pipe */
4290         if (init_thread_quit_pipe()) {
4291                 retval = -1;
4292                 goto exit_options;
4293         }
4294
4295         /* Setup the thread apps communication pipe. */
4296         if (create_relay_conn_pipe()) {
4297                 retval = -1;
4298                 goto exit_options;
4299         }
4300
4301         /* Init relay command queue. */
4302         cds_wfcq_init(&relay_conn_queue.head, &relay_conn_queue.tail);
4303
4304         /* Initialize communication library */
4305         lttcomm_init();
4306         lttcomm_inet_init();
4307
4308         /* tables of sessions indexed by session ID */
4309         sessions_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
4310         if (!sessions_ht) {
4311                 retval = -1;
4312                 goto exit_options;
4313         }
4314
4315         /* tables of streams indexed by stream ID */
4316         relay_streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
4317         if (!relay_streams_ht) {
4318                 retval = -1;
4319                 goto exit_options;
4320         }
4321
4322         /* tables of streams indexed by stream ID */
4323         viewer_streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
4324         if (!viewer_streams_ht) {
4325                 retval = -1;
4326                 goto exit_options;
4327         }
4328
4329         ret = init_health_quit_pipe();
4330         if (ret) {
4331                 retval = -1;
4332                 goto exit_options;
4333         }
4334
4335         /* Create thread to manage the client socket */
4336         ret = pthread_create(&health_thread, default_pthread_attr(),
4337                         thread_manage_health, (void *) NULL);
4338         if (ret) {
4339                 errno = ret;
4340                 PERROR("pthread_create health");
4341                 retval = -1;
4342                 goto exit_options;
4343         }
4344
4345         /* Setup the dispatcher thread */
4346         ret = pthread_create(&dispatcher_thread, default_pthread_attr(),
4347                         relay_thread_dispatcher, (void *) NULL);
4348         if (ret) {
4349                 errno = ret;
4350                 PERROR("pthread_create dispatcher");
4351                 retval = -1;
4352                 goto exit_dispatcher_thread;
4353         }
4354
4355         /* Setup the worker thread */
4356         ret = pthread_create(&worker_thread, default_pthread_attr(),
4357                         relay_thread_worker, NULL);
4358         if (ret) {
4359                 errno = ret;
4360                 PERROR("pthread_create worker");
4361                 retval = -1;
4362                 goto exit_worker_thread;
4363         }
4364
4365         /* Setup the listener thread */
4366         ret = pthread_create(&listener_thread, default_pthread_attr(),
4367                         relay_thread_listener, (void *) NULL);
4368         if (ret) {
4369                 errno = ret;
4370                 PERROR("pthread_create listener");
4371                 retval = -1;
4372                 goto exit_listener_thread;
4373         }
4374
4375         ret = relayd_live_create(live_uri);
4376         if (ret) {
4377                 ERR("Starting live viewer threads");
4378                 retval = -1;
4379                 goto exit_live;
4380         }
4381
4382         /*
4383          * This is where we start awaiting program completion (e.g. through
4384          * signal that asks threads to teardown).
4385          */
4386
4387         ret = relayd_live_join();
4388         if (ret) {
4389                 retval = -1;
4390         }
4391 exit_live:
4392
4393         ret = pthread_join(listener_thread, &status);
4394         if (ret) {
4395                 errno = ret;
4396                 PERROR("pthread_join listener_thread");
4397                 retval = -1;
4398         }
4399
4400 exit_listener_thread:
4401         ret = pthread_join(worker_thread, &status);
4402         if (ret) {
4403                 errno = ret;
4404                 PERROR("pthread_join worker_thread");
4405                 retval = -1;
4406         }
4407
4408 exit_worker_thread:
4409         ret = pthread_join(dispatcher_thread, &status);
4410         if (ret) {
4411                 errno = ret;
4412                 PERROR("pthread_join dispatcher_thread");
4413                 retval = -1;
4414         }
4415 exit_dispatcher_thread:
4416
4417         ret = pthread_join(health_thread, &status);
4418         if (ret) {
4419                 errno = ret;
4420                 PERROR("pthread_join health_thread");
4421                 retval = -1;
4422         }
4423 exit_options:
4424         /*
4425          * Wait for all pending call_rcu work to complete before tearing
4426          * down data structures. call_rcu worker may be trying to
4427          * perform lookups in those structures.
4428          */
4429         rcu_barrier();
4430         relayd_cleanup();
4431
4432         /* Ensure all prior call_rcu are done. */
4433         rcu_barrier();
4434
4435         if (thread_is_rcu_registered) {
4436                 rcu_unregister_thread();
4437         }
4438
4439         if (!retval) {
4440                 exit(EXIT_SUCCESS);
4441         } else {
4442                 exit(EXIT_FAILURE);
4443         }
4444 }