src/common/relayd/relayd.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <assert.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <inttypes.h>
  25
  26 #include <common/common.h>
  27 #include <common/defaults.h>
  28 #include <common/sessiond-comm/relayd.h>
  29 #include <common/index/lttng-index.h>
  30
  31 #include "relayd.h"
  32
  33 /*
  34  * Send command. Fill up the header and append the data.
  35  */
  36 static int send_command(struct lttcomm_relayd_sock *rsock,
  37                 enum lttcomm_relayd_command cmd, void *data, size_t size,
  38                 int flags)
  39 {
  40         int ret;
  41         struct lttcomm_relayd_hdr header;
  42         char *buf;
  43         uint64_t buf_size = sizeof(header);
  44
  45         if (rsock->sock.fd < 0) {
  46                 return -ECONNRESET;
  47         }
  48
  49         if (data) {
  50                 buf_size += size;
  51         }
  52
  53         buf = zmalloc(buf_size);
  54         if (buf == NULL) {
  55                 PERROR("zmalloc relayd send command buf");
  56                 ret = -1;
  57                 goto alloc_error;
  58         }
  59
  60         header.cmd = htobe32(cmd);
  61         header.data_size = htobe64(size);
  62
  63         /* Zeroed for now since not used. */
  64         header.cmd_version = 0;
  65         header.circuit_id = 0;
  66
  67         /* Prepare buffer to send. */
  68         memcpy(buf, &header, sizeof(header));
  69         if (data) {
  70                 memcpy(buf + sizeof(header), data, size);
  71         }
  72
  73         ret = rsock->sock.ops->sendmsg(&rsock->sock, buf, buf_size, flags);
  74         if (ret < 0) {
  75                 ret = -errno;
  76                 goto error;
  77         }
  78
  79         DBG3("Relayd sending command %d of size %" PRIu64, cmd, buf_size);
  80
  81 error:
  82         free(buf);
  83 alloc_error:
  84         return ret;
  85 }
  86
  87 /*
  88  * Receive reply data on socket. This MUST be call after send_command or else
  89  * could result in unexpected behavior(s).
  90  */
  91 static int recv_reply(struct lttcomm_relayd_sock *rsock, void *data, size_t size)
  92 {
  93         int ret;
  94
  95         if (rsock->sock.fd < 0) {
  96                 return -ECONNRESET;
  97         }
  98
  99         DBG3("Relayd waiting for reply of size %zu", size);
 100
 101         ret = rsock->sock.ops->recvmsg(&rsock->sock, data, size, 0);
 102         if (ret <= 0 || ret != size) {
 103                 if (ret == 0) {
 104                         /* Orderly shutdown. */
 105                         DBG("Socket %d has performed an orderly shutdown", rsock->sock.fd);
 106                 } else {
 107                         DBG("Receiving reply failed on sock %d for size %zu with ret %d",
 108                                         rsock->sock.fd, size, ret);
 109                 }
 110                 /* Always return -1 here and the caller can use errno. */
 111                 ret = -1;
 112                 goto error;
 113         }
 114
 115 error:
 116         return ret;
 117 }
 118
 119 /*
 120  * Starting at 2.4, RELAYD_CREATE_SESSION takes additional parameters to
 121  * support the live reading capability.
 122  */
 123 static int relayd_create_session_2_4(struct lttcomm_relayd_sock *rsock,
 124                 uint64_t *session_id, char *session_name, char *hostname,
 125                 int session_live_timer, unsigned int snapshot)
 126 {
 127         int ret;
 128         struct lttcomm_relayd_create_session_2_4 msg;
 129
 130         strncpy(msg.session_name, session_name, sizeof(msg.session_name));
 131         strncpy(msg.hostname, hostname, sizeof(msg.hostname));
 132         msg.live_timer = htobe32(session_live_timer);
 133         msg.snapshot = htobe32(snapshot);
 134
 135         /* Send command */
 136         ret = send_command(rsock, RELAYD_CREATE_SESSION, &msg, sizeof(msg), 0);
 137         if (ret < 0) {
 138                 goto error;
 139         }
 140
 141 error:
 142         return ret;
 143 }
 144
 145 /*
 146  * RELAYD_CREATE_SESSION from 2.1 to 2.3.
 147  */
 148 static int relayd_create_session_2_1(struct lttcomm_relayd_sock *rsock,
 149                 uint64_t *session_id)
 150 {
 151         int ret;
 152
 153         /* Send command */
 154         ret = send_command(rsock, RELAYD_CREATE_SESSION, NULL, 0, 0);
 155         if (ret < 0) {
 156                 goto error;
 157         }
 158
 159 error:
 160         return ret;
 161 }
 162
 163 /*
 164  * Send a RELAYD_CREATE_SESSION command to the relayd with the given socket and
 165  * set session_id of the relayd if we have a successful reply from the relayd.
 166  *
 167  * On success, return 0 else a negative value which is either an errno error or
 168  * a lttng error code from the relayd.
 169  */
 170 int relayd_create_session(struct lttcomm_relayd_sock *rsock, uint64_t *session_id,
 171                 char *session_name, char *hostname, int session_live_timer,
 172                 unsigned int snapshot)
 173 {
 174         int ret;
 175         struct lttcomm_relayd_status_session reply;
 176
 177         assert(rsock);
 178         assert(session_id);
 179
 180         DBG("Relayd create session");
 181
 182         switch(rsock->minor) {
 183                 case 1:
 184                 case 2:
 185                 case 3:
 186                         ret = relayd_create_session_2_1(rsock, session_id);
 187                         break;
 188                 case 4:
 189                 default:
 190                         ret = relayd_create_session_2_4(rsock, session_id, session_name,
 191                                         hostname, session_live_timer, snapshot);
 192                         break;
 193         }
 194
 195         if (ret < 0) {
 196                 goto error;
 197         }
 198
 199         /* Receive response */
 200         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 201         if (ret < 0) {
 202                 goto error;
 203         }
 204
 205         reply.session_id = be64toh(reply.session_id);
 206         reply.ret_code = be32toh(reply.ret_code);
 207
 208         /* Return session id or negative ret code. */
 209         if (reply.ret_code != LTTNG_OK) {
 210                 ret = -1;
 211                 ERR("Relayd create session replied error %d", reply.ret_code);
 212                 goto error;
 213         } else {
 214                 ret = 0;
 215                 *session_id = reply.session_id;
 216         }
 217
 218         DBG("Relayd session created with id %" PRIu64, reply.session_id);
 219
 220 error:
 221         return ret;
 222 }
 223
 224 /*
 225  * Add stream on the relayd and assign stream handle to the stream_id argument.
 226  *
 227  * On success return 0 else return ret_code negative value.
 228  */
 229 int relayd_add_stream(struct lttcomm_relayd_sock *rsock, const char *channel_name,
 230                 const char *pathname, uint64_t *stream_id,
 231                 uint64_t tracefile_size, uint64_t tracefile_count)
 232 {
 233         int ret;
 234         struct lttcomm_relayd_add_stream msg;
 235         struct lttcomm_relayd_add_stream_2_2 msg_2_2;
 236         struct lttcomm_relayd_status_stream reply;
 237
 238         /* Code flow error. Safety net. */
 239         assert(rsock);
 240         assert(channel_name);
 241         assert(pathname);
 242
 243         DBG("Relayd adding stream for channel name %s", channel_name);
 244
 245         /* Compat with relayd 2.1 */
 246         if (rsock->minor == 1) {
 247                 strncpy(msg.channel_name, channel_name, sizeof(msg.channel_name));
 248                 strncpy(msg.pathname, pathname, sizeof(msg.pathname));
 249
 250                 /* Send command */
 251                 ret = send_command(rsock, RELAYD_ADD_STREAM, (void *) &msg, sizeof(msg), 0);
 252                 if (ret < 0) {
 253                         goto error;
 254                 }
 255         } else {
 256                 /* Compat with relayd 2.2+ */
 257                 strncpy(msg_2_2.channel_name, channel_name, sizeof(msg_2_2.channel_name));
 258                 strncpy(msg_2_2.pathname, pathname, sizeof(msg_2_2.pathname));
 259                 msg_2_2.tracefile_size = htobe64(tracefile_size);
 260                 msg_2_2.tracefile_count = htobe64(tracefile_count);
 261
 262                 /* Send command */
 263                 ret = send_command(rsock, RELAYD_ADD_STREAM, (void *) &msg_2_2, sizeof(msg_2_2), 0);
 264                 if (ret < 0) {
 265                         goto error;
 266                 }
 267         }
 268
 269         /* Waiting for reply */
 270         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 271         if (ret < 0) {
 272                 goto error;
 273         }
 274
 275         /* Back to host bytes order. */
 276         reply.handle = be64toh(reply.handle);
 277         reply.ret_code = be32toh(reply.ret_code);
 278
 279         /* Return session id or negative ret code. */
 280         if (reply.ret_code != LTTNG_OK) {
 281                 ret = -1;
 282                 ERR("Relayd add stream replied error %d", reply.ret_code);
 283         } else {
 284                 /* Success */
 285                 ret = 0;
 286                 *stream_id = reply.handle;
 287         }
 288
 289         DBG("Relayd stream added successfully with handle %" PRIu64,
 290                 reply.handle);
 291
 292 error:
 293         return ret;
 294 }
 295
 296 /*
 297  * Check version numbers on the relayd.
 298  * If major versions are compatible, we assign minor_to_use to the
 299  * minor version of the procotol we are going to use for this session.
 300  *
 301  * Return 0 if compatible else negative value.
 302  */
 303 int relayd_version_check(struct lttcomm_relayd_sock *rsock)
 304 {
 305         int ret;
 306         struct lttcomm_relayd_version msg;
 307
 308         /* Code flow error. Safety net. */
 309         assert(rsock);
 310
 311         DBG("Relayd version check for major.minor %u.%u", rsock->major,
 312                         rsock->minor);
 313
 314         /* Prepare network byte order before transmission. */
 315         msg.major = htobe32(rsock->major);
 316         msg.minor = htobe32(rsock->minor);
 317
 318         /* Send command */
 319         ret = send_command(rsock, RELAYD_VERSION, (void *) &msg, sizeof(msg), 0);
 320         if (ret < 0) {
 321                 goto error;
 322         }
 323
 324         /* Receive response */
 325         ret = recv_reply(rsock, (void *) &msg, sizeof(msg));
 326         if (ret < 0) {
 327                 goto error;
 328         }
 329
 330         /* Set back to host bytes order */
 331         msg.major = be32toh(msg.major);
 332         msg.minor = be32toh(msg.minor);
 333
 334         /*
 335          * Only validate the major version. If the other side is higher,
 336          * communication is not possible. Only major version equal can talk to each
 337          * other. If the minor version differs, the lowest version is used by both
 338          * sides.
 339          */
 340         if (msg.major != rsock->major) {
 341                 /* Not compatible */
 342                 ret = -1;
 343                 DBG2("Relayd version is NOT compatible. Relayd version %u != %u (us)",
 344                                 msg.major, rsock->major);
 345                 goto error;
 346         }
 347
 348         /*
 349          * If the relayd's minor version is higher, it will adapt to our version so
 350          * we can continue to use the latest relayd communication data structure.
 351          * If the received minor version is higher, the relayd should adapt to us.
 352          */
 353         if (rsock->minor > msg.minor) {
 354                 rsock->minor = msg.minor;
 355         }
 356
 357         /* Version number compatible */
 358         DBG2("Relayd version is compatible, using protocol version %u.%u",
 359                         rsock->major, rsock->minor);
 360         ret = 0;
 361
 362 error:
 363         return ret;
 364 }
 365
 366 /*
 367  * Add stream on the relayd and assign stream handle to the stream_id argument.
 368  *
 369  * On success return 0 else return ret_code negative value.
 370  */
 371 int relayd_send_metadata(struct lttcomm_relayd_sock *rsock, size_t len)
 372 {
 373         int ret;
 374
 375         /* Code flow error. Safety net. */
 376         assert(rsock);
 377
 378         DBG("Relayd sending metadata of size %zu", len);
 379
 380         /* Send command */
 381         ret = send_command(rsock, RELAYD_SEND_METADATA, NULL, len, 0);
 382         if (ret < 0) {
 383                 goto error;
 384         }
 385
 386         DBG2("Relayd metadata added successfully");
 387
 388         /*
 389          * After that call, the metadata data MUST be sent to the relayd so the
 390          * receive size on the other end matches the len of the metadata packet
 391          * header. This is why we don't wait for a reply here.
 392          */
 393
 394 error:
 395         return ret;
 396 }
 397
 398 /*
 399  * Connect to relay daemon with an allocated lttcomm_relayd_sock.
 400  */
 401 int relayd_connect(struct lttcomm_relayd_sock *rsock)
 402 {
 403         /* Code flow error. Safety net. */
 404         assert(rsock);
 405
 406         if (!rsock->sock.ops) {
 407                 /*
 408                  * Attempting a connect on a non-initialized socket.
 409                  */
 410                 return -ECONNRESET;
 411         }
 412
 413         DBG3("Relayd connect ...");
 414
 415         return rsock->sock.ops->connect(&rsock->sock);
 416 }
 417
 418 /*
 419  * Close relayd socket with an allocated lttcomm_relayd_sock.
 420  *
 421  * If no socket operations are found, simply return 0 meaning that everything
 422  * is fine. Without operations, the socket can not possibly be opened or used.
 423  * This is possible if the socket was allocated but not created. However, the
 424  * caller could simply use it to store a valid file descriptor for instance
 425  * passed over a Unix socket and call this to cleanup but still without a valid
 426  * ops pointer.
 427  *
 428  * Return the close returned value. On error, a negative value is usually
 429  * returned back from close(2).
 430  */
 431 int relayd_close(struct lttcomm_relayd_sock *rsock)
 432 {
 433         int ret;
 434
 435         /* Code flow error. Safety net. */
 436         assert(rsock);
 437
 438         /* An invalid fd is fine, return success. */
 439         if (rsock->sock.fd < 0) {
 440                 ret = 0;
 441                 goto end;
 442         }
 443
 444         DBG3("Relayd closing socket %d", rsock->sock.fd);
 445
 446         if (rsock->sock.ops) {
 447                 ret = rsock->sock.ops->close(&rsock->sock);
 448         } else {
 449                 /* Default call if no specific ops found. */
 450                 ret = close(rsock->sock.fd);
 451                 if (ret < 0) {
 452                         PERROR("relayd_close default close");
 453                 }
 454         }
 455         rsock->sock.fd = -1;
 456
 457 end:
 458         return ret;
 459 }
 460
 461 /*
 462  * Send data header structure to the relayd.
 463  */
 464 int relayd_send_data_hdr(struct lttcomm_relayd_sock *rsock,
 465                 struct lttcomm_relayd_data_hdr *hdr, size_t size)
 466 {
 467         int ret;
 468
 469         /* Code flow error. Safety net. */
 470         assert(rsock);
 471         assert(hdr);
 472
 473         if (rsock->sock.fd < 0) {
 474                 return -ECONNRESET;
 475         }
 476
 477         DBG3("Relayd sending data header of size %zu", size);
 478
 479         /* Again, safety net */
 480         if (size == 0) {
 481                 size = sizeof(struct lttcomm_relayd_data_hdr);
 482         }
 483
 484         /* Only send data header. */
 485         ret = rsock->sock.ops->sendmsg(&rsock->sock, hdr, size, 0);
 486         if (ret < 0) {
 487                 ret = -errno;
 488                 goto error;
 489         }
 490
 491         /*
 492          * The data MUST be sent right after that command for the receive on the
 493          * other end to match the size in the header.
 494          */
 495
 496 error:
 497         return ret;
 498 }
 499
 500 /*
 501  * Send close stream command to the relayd.
 502  */
 503 int relayd_send_close_stream(struct lttcomm_relayd_sock *rsock, uint64_t stream_id,
 504                 uint64_t last_net_seq_num)
 505 {
 506         int ret;
 507         struct lttcomm_relayd_close_stream msg;
 508         struct lttcomm_relayd_generic_reply reply;
 509
 510         /* Code flow error. Safety net. */
 511         assert(rsock);
 512
 513         DBG("Relayd closing stream id %" PRIu64, stream_id);
 514
 515         msg.stream_id = htobe64(stream_id);
 516         msg.last_net_seq_num = htobe64(last_net_seq_num);
 517
 518         /* Send command */
 519         ret = send_command(rsock, RELAYD_CLOSE_STREAM, (void *) &msg, sizeof(msg), 0);
 520         if (ret < 0) {
 521                 goto error;
 522         }
 523
 524         /* Receive response */
 525         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 526         if (ret < 0) {
 527                 goto error;
 528         }
 529
 530         reply.ret_code = be32toh(reply.ret_code);
 531
 532         /* Return session id or negative ret code. */
 533         if (reply.ret_code != LTTNG_OK) {
 534                 ret = -1;
 535                 ERR("Relayd close stream replied error %d", reply.ret_code);
 536         } else {
 537                 /* Success */
 538                 ret = 0;
 539         }
 540
 541         DBG("Relayd close stream id %" PRIu64 " successfully", stream_id);
 542
 543 error:
 544         return ret;
 545 }
 546
 547 /*
 548  * Check for data availability for a given stream id.
 549  *
 550  * Return 0 if NOT pending, 1 if so and a negative value on error.
 551  */
 552 int relayd_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t stream_id,
 553                 uint64_t last_net_seq_num)
 554 {
 555         int ret;
 556         struct lttcomm_relayd_data_pending msg;
 557         struct lttcomm_relayd_generic_reply reply;
 558
 559         /* Code flow error. Safety net. */
 560         assert(rsock);
 561
 562         DBG("Relayd data pending for stream id %" PRIu64, stream_id);
 563
 564         msg.stream_id = htobe64(stream_id);
 565         msg.last_net_seq_num = htobe64(last_net_seq_num);
 566
 567         /* Send command */
 568         ret = send_command(rsock, RELAYD_DATA_PENDING, (void *) &msg,
 569                         sizeof(msg), 0);
 570         if (ret < 0) {
 571                 goto error;
 572         }
 573
 574         /* Receive response */
 575         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 576         if (ret < 0) {
 577                 goto error;
 578         }
 579
 580         reply.ret_code = be32toh(reply.ret_code);
 581
 582         /* Return session id or negative ret code. */
 583         if (reply.ret_code >= LTTNG_OK) {
 584                 ERR("Relayd data pending replied error %d", reply.ret_code);
 585         }
 586
 587         /* At this point, the ret code is either 1 or 0 */
 588         ret = reply.ret_code;
 589
 590         DBG("Relayd data is %s pending for stream id %" PRIu64,
 591                         ret == 1 ? "" : "NOT", stream_id);
 592
 593 error:
 594         return ret;
 595 }
 596
 597 /*
 598  * Check on the relayd side for a quiescent state on the control socket.
 599  */
 600 int relayd_quiescent_control(struct lttcomm_relayd_sock *rsock,
 601                 uint64_t metadata_stream_id)
 602 {
 603         int ret;
 604         struct lttcomm_relayd_quiescent_control msg;
 605         struct lttcomm_relayd_generic_reply reply;
 606
 607         /* Code flow error. Safety net. */
 608         assert(rsock);
 609
 610         DBG("Relayd checking quiescent control state");
 611
 612         msg.stream_id = htobe64(metadata_stream_id);
 613
 614         /* Send command */
 615         ret = send_command(rsock, RELAYD_QUIESCENT_CONTROL, &msg, sizeof(msg), 0);
 616         if (ret < 0) {
 617                 goto error;
 618         }
 619
 620         /* Receive response */
 621         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 622         if (ret < 0) {
 623                 goto error;
 624         }
 625
 626         reply.ret_code = be32toh(reply.ret_code);
 627
 628         /* Return session id or negative ret code. */
 629         if (reply.ret_code != LTTNG_OK) {
 630                 ret = -1;
 631                 ERR("Relayd quiescent control replied error %d", reply.ret_code);
 632                 goto error;
 633         }
 634
 635         /* Control socket is quiescent */
 636         return 0;
 637
 638 error:
 639         return ret;
 640 }
 641
 642 /*
 643  * Begin a data pending command for a specific session id.
 644  */
 645 int relayd_begin_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t id)
 646 {
 647         int ret;
 648         struct lttcomm_relayd_begin_data_pending msg;
 649         struct lttcomm_relayd_generic_reply reply;
 650
 651         /* Code flow error. Safety net. */
 652         assert(rsock);
 653
 654         DBG("Relayd begin data pending");
 655
 656         msg.session_id = htobe64(id);
 657
 658         /* Send command */
 659         ret = send_command(rsock, RELAYD_BEGIN_DATA_PENDING, &msg, sizeof(msg), 0);
 660         if (ret < 0) {
 661                 goto error;
 662         }
 663
 664         /* Receive response */
 665         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 666         if (ret < 0) {
 667                 goto error;
 668         }
 669
 670         reply.ret_code = be32toh(reply.ret_code);
 671
 672         /* Return session id or negative ret code. */
 673         if (reply.ret_code != LTTNG_OK) {
 674                 ret = -1;
 675                 ERR("Relayd begin data pending replied error %d", reply.ret_code);
 676                 goto error;
 677         }
 678
 679         return 0;
 680
 681 error:
 682         return ret;
 683 }
 684
 685 /*
 686  * End a data pending command for a specific session id.
 687  *
 688  * Return 0 on success and set is_data_inflight to 0 if no data is being
 689  * streamed or 1 if it is the case.
 690  */
 691 int relayd_end_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t id,
 692                 unsigned int *is_data_inflight)
 693 {
 694         int ret, recv_ret;
 695         struct lttcomm_relayd_end_data_pending msg;
 696         struct lttcomm_relayd_generic_reply reply;
 697
 698         /* Code flow error. Safety net. */
 699         assert(rsock);
 700
 701         DBG("Relayd end data pending");
 702
 703         msg.session_id = htobe64(id);
 704
 705         /* Send command */
 706         ret = send_command(rsock, RELAYD_END_DATA_PENDING, &msg, sizeof(msg), 0);
 707         if (ret < 0) {
 708                 goto error;
 709         }
 710
 711         /* Receive response */
 712         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 713         if (ret < 0) {
 714                 goto error;
 715         }
 716
 717         recv_ret = be32toh(reply.ret_code);
 718         if (recv_ret < 0) {
 719                 ret = recv_ret;
 720                 goto error;
 721         }
 722
 723         *is_data_inflight = recv_ret;
 724
 725         DBG("Relayd end data pending is data inflight: %d", recv_ret);
 726
 727         return 0;
 728
 729 error:
 730         return ret;
 731 }
 732
 733 /*
 734  * Send index to the relayd.
 735  */
 736 int relayd_send_index(struct lttcomm_relayd_sock *rsock,
 737                 struct lttng_packet_index *index, uint64_t relay_stream_id,
 738                 uint64_t net_seq_num)
 739 {
 740         int ret;
 741         struct lttcomm_relayd_index msg;
 742         struct lttcomm_relayd_generic_reply reply;
 743
 744         /* Code flow error. Safety net. */
 745         assert(rsock);
 746
 747         if (rsock->minor < 4) {
 748                 DBG("Not sending indexes before protocol 2.4");
 749                 ret = 0;
 750                 goto error;
 751         }
 752
 753         DBG("Relayd sending index for stream ID %" PRIu64, relay_stream_id);
 754
 755         msg.relay_stream_id = htobe64(relay_stream_id);
 756         msg.net_seq_num = htobe64(net_seq_num);
 757
 758         /* The index is already in big endian. */
 759         msg.packet_size = index->packet_size;
 760         msg.content_size = index->content_size;
 761         msg.timestamp_begin = index->timestamp_begin;
 762         msg.timestamp_end = index->timestamp_end;
 763         msg.events_discarded = index->events_discarded;
 764         msg.stream_id = index->stream_id;
 765
 766         /* Send command */
 767         ret = send_command(rsock, RELAYD_SEND_INDEX, &msg, sizeof(msg), 0);
 768         if (ret < 0) {
 769                 goto error;
 770         }
 771
 772         /* Receive response */
 773         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 774         if (ret < 0) {
 775                 goto error;
 776         }
 777
 778         reply.ret_code = be32toh(reply.ret_code);
 779
 780         /* Return session id or negative ret code. */
 781         if (reply.ret_code != LTTNG_OK) {
 782                 ret = -1;
 783                 ERR("Relayd send index replied error %d", reply.ret_code);
 784         } else {
 785                 /* Success */
 786                 ret = 0;
 787         }
 788
 789 error:
 790         return ret;
 791 }