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)
 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
 134         /* Send command */
 135         ret = send_command(rsock, RELAYD_CREATE_SESSION, &msg, sizeof(msg), 0);
 136         if (ret < 0) {
 137                 goto error;
 138         }
 139
 140 error:
 141         return ret;
 142 }
 143
 144 /*
 145  * RELAYD_CREATE_SESSION from 2.1 to 2.3.
 146  */
 147 static int relayd_create_session_2_1(struct lttcomm_relayd_sock *rsock,
 148                 uint64_t *session_id)
 149 {
 150         int ret;
 151
 152         /* Send command */
 153         ret = send_command(rsock, RELAYD_CREATE_SESSION, NULL, 0, 0);
 154         if (ret < 0) {
 155                 goto error;
 156         }
 157
 158 error:
 159         return ret;
 160 }
 161
 162 /*
 163  * Send a RELAYD_CREATE_SESSION command to the relayd with the given socket and
 164  * set session_id of the relayd if we have a successful reply from the relayd.
 165  *
 166  * On success, return 0 else a negative value which is either an errno error or
 167  * a lttng error code from the relayd.
 168  */
 169 int relayd_create_session(struct lttcomm_relayd_sock *rsock, uint64_t *session_id,
 170                 char *session_name, char *hostname, int session_live_timer)
 171 {
 172         int ret;
 173         struct lttcomm_relayd_status_session reply;
 174
 175         assert(rsock);
 176         assert(session_id);
 177
 178         DBG("Relayd create session");
 179
 180         switch(rsock->minor) {
 181                 case 1:
 182                 case 2:
 183                 case 3:
 184                         ret = relayd_create_session_2_1(rsock, session_id);
 185                 case 4:
 186                 default:
 187                         ret = relayd_create_session_2_4(rsock, session_id,
 188                                         session_name, hostname,
 189                                         session_live_timer);
 190         }
 191
 192         if (ret < 0) {
 193                 goto error;
 194         }
 195
 196         /* Receive response */
 197         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 198         if (ret < 0) {
 199                 goto error;
 200         }
 201
 202         reply.session_id = be64toh(reply.session_id);
 203         reply.ret_code = be32toh(reply.ret_code);
 204
 205         /* Return session id or negative ret code. */
 206         if (reply.ret_code != LTTNG_OK) {
 207                 ret = -1;
 208                 ERR("Relayd create session replied error %d", reply.ret_code);
 209                 goto error;
 210         } else {
 211                 ret = 0;
 212                 *session_id = reply.session_id;
 213         }
 214
 215         DBG("Relayd session created with id %" PRIu64, reply.session_id);
 216
 217 error:
 218         return ret;
 219 }
 220
 221 /*
 222  * Add stream on the relayd and assign stream handle to the stream_id argument.
 223  *
 224  * On success return 0 else return ret_code negative value.
 225  */
 226 int relayd_add_stream(struct lttcomm_relayd_sock *rsock, const char *channel_name,
 227                 const char *pathname, uint64_t *stream_id,
 228                 uint64_t tracefile_size, uint64_t tracefile_count)
 229 {
 230         int ret;
 231         struct lttcomm_relayd_add_stream msg;
 232         struct lttcomm_relayd_add_stream_2_2 msg_2_2;
 233         struct lttcomm_relayd_status_stream reply;
 234
 235         /* Code flow error. Safety net. */
 236         assert(rsock);
 237         assert(channel_name);
 238         assert(pathname);
 239
 240         DBG("Relayd adding stream for channel name %s", channel_name);
 241
 242         /* Compat with relayd 2.1 */
 243         if (rsock->minor == 1) {
 244                 strncpy(msg.channel_name, channel_name, sizeof(msg.channel_name));
 245                 strncpy(msg.pathname, pathname, sizeof(msg.pathname));
 246
 247                 /* Send command */
 248                 ret = send_command(rsock, RELAYD_ADD_STREAM, (void *) &msg, sizeof(msg), 0);
 249                 if (ret < 0) {
 250                         goto error;
 251                 }
 252         } else {
 253                 /* Compat with relayd 2.2+ */
 254                 strncpy(msg_2_2.channel_name, channel_name, sizeof(msg_2_2.channel_name));
 255                 strncpy(msg_2_2.pathname, pathname, sizeof(msg_2_2.pathname));
 256                 msg_2_2.tracefile_size = htobe64(tracefile_size);
 257                 msg_2_2.tracefile_count = htobe64(tracefile_count);
 258
 259                 /* Send command */
 260                 ret = send_command(rsock, RELAYD_ADD_STREAM, (void *) &msg_2_2, sizeof(msg_2_2), 0);
 261                 if (ret < 0) {
 262                         goto error;
 263                 }
 264         }
 265
 266         /* Waiting for reply */
 267         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 268         if (ret < 0) {
 269                 goto error;
 270         }
 271
 272         /* Back to host bytes order. */
 273         reply.handle = be64toh(reply.handle);
 274         reply.ret_code = be32toh(reply.ret_code);
 275
 276         /* Return session id or negative ret code. */
 277         if (reply.ret_code != LTTNG_OK) {
 278                 ret = -1;
 279                 ERR("Relayd add stream replied error %d", reply.ret_code);
 280         } else {
 281                 /* Success */
 282                 ret = 0;
 283                 *stream_id = reply.handle;
 284         }
 285
 286         DBG("Relayd stream added successfully with handle %" PRIu64,
 287                 reply.handle);
 288
 289 error:
 290         return ret;
 291 }
 292
 293 /*
 294  * Check version numbers on the relayd.
 295  * If major versions are compatible, we assign minor_to_use to the
 296  * minor version of the procotol we are going to use for this session.
 297  *
 298  * Return 0 if compatible else negative value.
 299  */
 300 int relayd_version_check(struct lttcomm_relayd_sock *rsock)
 301 {
 302         int ret;
 303         struct lttcomm_relayd_version msg;
 304
 305         /* Code flow error. Safety net. */
 306         assert(rsock);
 307
 308         DBG("Relayd version check for major.minor %u.%u", rsock->major,
 309                         rsock->minor);
 310
 311         /* Prepare network byte order before transmission. */
 312         msg.major = htobe32(rsock->major);
 313         msg.minor = htobe32(rsock->minor);
 314
 315         /* Send command */
 316         ret = send_command(rsock, RELAYD_VERSION, (void *) &msg, sizeof(msg), 0);
 317         if (ret < 0) {
 318                 goto error;
 319         }
 320
 321         /* Receive response */
 322         ret = recv_reply(rsock, (void *) &msg, sizeof(msg));
 323         if (ret < 0) {
 324                 goto error;
 325         }
 326
 327         /* Set back to host bytes order */
 328         msg.major = be32toh(msg.major);
 329         msg.minor = be32toh(msg.minor);
 330
 331         /*
 332          * Only validate the major version. If the other side is higher,
 333          * communication is not possible. Only major version equal can talk to each
 334          * other. If the minor version differs, the lowest version is used by both
 335          * sides.
 336          */
 337         if (msg.major != rsock->major) {
 338                 /* Not compatible */
 339                 ret = -1;
 340                 DBG2("Relayd version is NOT compatible. Relayd version %u != %u (us)",
 341                                 msg.major, rsock->major);
 342                 goto error;
 343         }
 344
 345         /*
 346          * If the relayd's minor version is higher, it will adapt to our version so
 347          * we can continue to use the latest relayd communication data structure.
 348          * If the received minor version is higher, the relayd should adapt to us.
 349          */
 350         if (rsock->minor > msg.minor) {
 351                 rsock->minor = msg.minor;
 352         }
 353
 354         /* Version number compatible */
 355         DBG2("Relayd version is compatible, using protocol version %u.%u",
 356                         rsock->major, rsock->minor);
 357         ret = 0;
 358
 359 error:
 360         return ret;
 361 }
 362
 363 /*
 364  * Add stream on the relayd and assign stream handle to the stream_id argument.
 365  *
 366  * On success return 0 else return ret_code negative value.
 367  */
 368 int relayd_send_metadata(struct lttcomm_relayd_sock *rsock, size_t len)
 369 {
 370         int ret;
 371
 372         /* Code flow error. Safety net. */
 373         assert(rsock);
 374
 375         DBG("Relayd sending metadata of size %zu", len);
 376
 377         /* Send command */
 378         ret = send_command(rsock, RELAYD_SEND_METADATA, NULL, len, 0);
 379         if (ret < 0) {
 380                 goto error;
 381         }
 382
 383         DBG2("Relayd metadata added successfully");
 384
 385         /*
 386          * After that call, the metadata data MUST be sent to the relayd so the
 387          * receive size on the other end matches the len of the metadata packet
 388          * header. This is why we don't wait for a reply here.
 389          */
 390
 391 error:
 392         return ret;
 393 }
 394
 395 /*
 396  * Connect to relay daemon with an allocated lttcomm_relayd_sock.
 397  */
 398 int relayd_connect(struct lttcomm_relayd_sock *rsock)
 399 {
 400         /* Code flow error. Safety net. */
 401         assert(rsock);
 402
 403         if (!rsock->sock.ops) {
 404                 /*
 405                  * Attempting a connect on a non-initialized socket.
 406                  */
 407                 return -ECONNRESET;
 408         }
 409
 410         DBG3("Relayd connect ...");
 411
 412         return rsock->sock.ops->connect(&rsock->sock);
 413 }
 414
 415 /*
 416  * Close relayd socket with an allocated lttcomm_relayd_sock.
 417  *
 418  * If no socket operations are found, simply return 0 meaning that everything
 419  * is fine. Without operations, the socket can not possibly be opened or used.
 420  * This is possible if the socket was allocated but not created. However, the
 421  * caller could simply use it to store a valid file descriptor for instance
 422  * passed over a Unix socket and call this to cleanup but still without a valid
 423  * ops pointer.
 424  *
 425  * Return the close returned value. On error, a negative value is usually
 426  * returned back from close(2).
 427  */
 428 int relayd_close(struct lttcomm_relayd_sock *rsock)
 429 {
 430         int ret;
 431
 432         /* Code flow error. Safety net. */
 433         assert(rsock);
 434
 435         /* An invalid fd is fine, return success. */
 436         if (rsock->sock.fd < 0) {
 437                 ret = 0;
 438                 goto end;
 439         }
 440
 441         DBG3("Relayd closing socket %d", rsock->sock.fd);
 442
 443         if (rsock->sock.ops) {
 444                 ret = rsock->sock.ops->close(&rsock->sock);
 445         } else {
 446                 /* Default call if no specific ops found. */
 447                 ret = close(rsock->sock.fd);
 448                 if (ret < 0) {
 449                         PERROR("relayd_close default close");
 450                 }
 451         }
 452         rsock->sock.fd = -1;
 453
 454 end:
 455         return ret;
 456 }
 457
 458 /*
 459  * Send data header structure to the relayd.
 460  */
 461 int relayd_send_data_hdr(struct lttcomm_relayd_sock *rsock,
 462                 struct lttcomm_relayd_data_hdr *hdr, size_t size)
 463 {
 464         int ret;
 465
 466         /* Code flow error. Safety net. */
 467         assert(rsock);
 468         assert(hdr);
 469
 470         if (rsock->sock.fd < 0) {
 471                 return -ECONNRESET;
 472         }
 473
 474         DBG3("Relayd sending data header of size %zu", size);
 475
 476         /* Again, safety net */
 477         if (size == 0) {
 478                 size = sizeof(struct lttcomm_relayd_data_hdr);
 479         }
 480
 481         /* Only send data header. */
 482         ret = rsock->sock.ops->sendmsg(&rsock->sock, hdr, size, 0);
 483         if (ret < 0) {
 484                 ret = -errno;
 485                 goto error;
 486         }
 487
 488         /*
 489          * The data MUST be sent right after that command for the receive on the
 490          * other end to match the size in the header.
 491          */
 492
 493 error:
 494         return ret;
 495 }
 496
 497 /*
 498  * Send close stream command to the relayd.
 499  */
 500 int relayd_send_close_stream(struct lttcomm_relayd_sock *rsock, uint64_t stream_id,
 501                 uint64_t last_net_seq_num)
 502 {
 503         int ret;
 504         struct lttcomm_relayd_close_stream msg;
 505         struct lttcomm_relayd_generic_reply reply;
 506
 507         /* Code flow error. Safety net. */
 508         assert(rsock);
 509
 510         DBG("Relayd closing stream id %" PRIu64, stream_id);
 511
 512         msg.stream_id = htobe64(stream_id);
 513         msg.last_net_seq_num = htobe64(last_net_seq_num);
 514
 515         /* Send command */
 516         ret = send_command(rsock, RELAYD_CLOSE_STREAM, (void *) &msg, sizeof(msg), 0);
 517         if (ret < 0) {
 518                 goto error;
 519         }
 520
 521         /* Receive response */
 522         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 523         if (ret < 0) {
 524                 goto error;
 525         }
 526
 527         reply.ret_code = be32toh(reply.ret_code);
 528
 529         /* Return session id or negative ret code. */
 530         if (reply.ret_code != LTTNG_OK) {
 531                 ret = -1;
 532                 ERR("Relayd close stream replied error %d", reply.ret_code);
 533         } else {
 534                 /* Success */
 535                 ret = 0;
 536         }
 537
 538         DBG("Relayd close stream id %" PRIu64 " successfully", stream_id);
 539
 540 error:
 541         return ret;
 542 }
 543
 544 /*
 545  * Check for data availability for a given stream id.
 546  *
 547  * Return 0 if NOT pending, 1 if so and a negative value on error.
 548  */
 549 int relayd_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t stream_id,
 550                 uint64_t last_net_seq_num)
 551 {
 552         int ret;
 553         struct lttcomm_relayd_data_pending msg;
 554         struct lttcomm_relayd_generic_reply reply;
 555
 556         /* Code flow error. Safety net. */
 557         assert(rsock);
 558
 559         DBG("Relayd data pending for stream id %" PRIu64, stream_id);
 560
 561         msg.stream_id = htobe64(stream_id);
 562         msg.last_net_seq_num = htobe64(last_net_seq_num);
 563
 564         /* Send command */
 565         ret = send_command(rsock, RELAYD_DATA_PENDING, (void *) &msg,
 566                         sizeof(msg), 0);
 567         if (ret < 0) {
 568                 goto error;
 569         }
 570
 571         /* Receive response */
 572         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 573         if (ret < 0) {
 574                 goto error;
 575         }
 576
 577         reply.ret_code = be32toh(reply.ret_code);
 578
 579         /* Return session id or negative ret code. */
 580         if (reply.ret_code >= LTTNG_OK) {
 581                 ERR("Relayd data pending replied error %d", reply.ret_code);
 582         }
 583
 584         /* At this point, the ret code is either 1 or 0 */
 585         ret = reply.ret_code;
 586
 587         DBG("Relayd data is %s pending for stream id %" PRIu64,
 588                         ret == 1 ? "" : "NOT", stream_id);
 589
 590 error:
 591         return ret;
 592 }
 593
 594 /*
 595  * Check on the relayd side for a quiescent state on the control socket.
 596  */
 597 int relayd_quiescent_control(struct lttcomm_relayd_sock *rsock,
 598                 uint64_t metadata_stream_id)
 599 {
 600         int ret;
 601         struct lttcomm_relayd_quiescent_control msg;
 602         struct lttcomm_relayd_generic_reply reply;
 603
 604         /* Code flow error. Safety net. */
 605         assert(rsock);
 606
 607         DBG("Relayd checking quiescent control state");
 608
 609         msg.stream_id = htobe64(metadata_stream_id);
 610
 611         /* Send command */
 612         ret = send_command(rsock, RELAYD_QUIESCENT_CONTROL, &msg, sizeof(msg), 0);
 613         if (ret < 0) {
 614                 goto error;
 615         }
 616
 617         /* Receive response */
 618         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 619         if (ret < 0) {
 620                 goto error;
 621         }
 622
 623         reply.ret_code = be32toh(reply.ret_code);
 624
 625         /* Return session id or negative ret code. */
 626         if (reply.ret_code != LTTNG_OK) {
 627                 ret = -1;
 628                 ERR("Relayd quiescent control replied error %d", reply.ret_code);
 629                 goto error;
 630         }
 631
 632         /* Control socket is quiescent */
 633         return 0;
 634
 635 error:
 636         return ret;
 637 }
 638
 639 /*
 640  * Begin a data pending command for a specific session id.
 641  */
 642 int relayd_begin_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t id)
 643 {
 644         int ret;
 645         struct lttcomm_relayd_begin_data_pending msg;
 646         struct lttcomm_relayd_generic_reply reply;
 647
 648         /* Code flow error. Safety net. */
 649         assert(rsock);
 650
 651         DBG("Relayd begin data pending");
 652
 653         msg.session_id = htobe64(id);
 654
 655         /* Send command */
 656         ret = send_command(rsock, RELAYD_BEGIN_DATA_PENDING, &msg, sizeof(msg), 0);
 657         if (ret < 0) {
 658                 goto error;
 659         }
 660
 661         /* Receive response */
 662         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 663         if (ret < 0) {
 664                 goto error;
 665         }
 666
 667         reply.ret_code = be32toh(reply.ret_code);
 668
 669         /* Return session id or negative ret code. */
 670         if (reply.ret_code != LTTNG_OK) {
 671                 ret = -1;
 672                 ERR("Relayd begin data pending replied error %d", reply.ret_code);
 673                 goto error;
 674         }
 675
 676         return 0;
 677
 678 error:
 679         return ret;
 680 }
 681
 682 /*
 683  * End a data pending command for a specific session id.
 684  *
 685  * Return 0 on success and set is_data_inflight to 0 if no data is being
 686  * streamed or 1 if it is the case.
 687  */
 688 int relayd_end_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t id,
 689                 unsigned int *is_data_inflight)
 690 {
 691         int ret;
 692         struct lttcomm_relayd_end_data_pending msg;
 693         struct lttcomm_relayd_generic_reply reply;
 694
 695         /* Code flow error. Safety net. */
 696         assert(rsock);
 697
 698         DBG("Relayd end data pending");
 699
 700         msg.session_id = htobe64(id);
 701
 702         /* Send command */
 703         ret = send_command(rsock, RELAYD_END_DATA_PENDING, &msg, sizeof(msg), 0);
 704         if (ret < 0) {
 705                 goto error;
 706         }
 707
 708         /* Receive response */
 709         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 710         if (ret < 0) {
 711                 goto error;
 712         }
 713
 714         reply.ret_code = be32toh(reply.ret_code);
 715         if (reply.ret_code < 0) {
 716                 ret = reply.ret_code;
 717                 goto error;
 718         }
 719
 720         *is_data_inflight = reply.ret_code;
 721
 722         DBG("Relayd end data pending is data inflight: %d", reply.ret_code);
 723
 724         return 0;
 725
 726 error:
 727         return ret;
 728 }
 729
 730 /*
 731  * Send index to the relayd.
 732  */
 733 int relayd_send_index(struct lttcomm_relayd_sock *rsock,
 734                 struct lttng_packet_index *index, uint64_t relay_stream_id,
 735                 uint64_t net_seq_num)
 736 {
 737         int ret;
 738         struct lttcomm_relayd_index msg;
 739         struct lttcomm_relayd_generic_reply reply;
 740
 741         /* Code flow error. Safety net. */
 742         assert(rsock);
 743
 744         if (rsock->minor < 4) {
 745                 DBG("Not sending indexes before protocol 2.4");
 746                 ret = 0;
 747                 goto error;
 748         }
 749
 750         DBG("Relayd sending index for stream ID %" PRIu64, relay_stream_id);
 751
 752         msg.relay_stream_id = htobe64(relay_stream_id);
 753         msg.net_seq_num = htobe64(net_seq_num);
 754
 755         /* The index is already in big endian. */
 756         msg.packet_size = index->packet_size;
 757         msg.content_size = index->content_size;
 758         msg.timestamp_begin = index->timestamp_begin;
 759         msg.timestamp_end = index->timestamp_end;
 760         msg.events_discarded = index->events_discarded;
 761         msg.stream_id = index->stream_id;
 762
 763         /* Send command */
 764         ret = send_command(rsock, RELAYD_SEND_INDEX, &msg, sizeof(msg), 0);
 765         if (ret < 0) {
 766                 goto error;
 767         }
 768
 769         /* Receive response */
 770         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 771         if (ret < 0) {
 772                 goto error;
 773         }
 774
 775         reply.ret_code = be32toh(reply.ret_code);
 776
 777         /* Return session id or negative ret code. */
 778         if (reply.ret_code != LTTNG_OK) {
 779                 ret = -1;
 780                 ERR("Relayd send index replied error %d", reply.ret_code);
 781         } else {
 782                 /* Success */
 783                 ret = 0;
 784         }
 785
 786 error:
 787         return ret;
 788 }