src/bin/lttng-sessiond/consumer.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 _LGPL_SOURCE
  19 #include <assert.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <inttypes.h>
  27
  28 #include <common/common.h>
  29 #include <common/defaults.h>
  30 #include <common/uri.h>
  31 #include <common/relayd/relayd.h>
  32
  33 #include "consumer.h"
  34 #include "health-sessiond.h"
  35 #include "ust-app.h"
  36 #include "utils.h"
  37
  38 /*
  39  * Send a data payload using a given consumer socket of size len.
  40  *
  41  * The consumer socket lock MUST be acquired before calling this since this
  42  * function can change the fd value.
  43  *
  44  * Return 0 on success else a negative value on error.
  45  */
  46 int consumer_socket_send(struct consumer_socket *socket, void *msg, size_t len)
  47 {
  48         int fd;
  49         ssize_t size;
  50
  51         assert(socket);
  52         assert(socket->fd_ptr);
  53         assert(msg);
  54
  55         /* Consumer socket is invalid. Stopping. */
  56         fd = *socket->fd_ptr;
  57         if (fd < 0) {
  58                 goto error;
  59         }
  60
  61         size = lttcomm_send_unix_sock(fd, msg, len);
  62         if (size < 0) {
  63                 /* The above call will print a PERROR on error. */
  64                 DBG("Error when sending data to consumer on sock %d", fd);
  65                 /*
  66                  * At this point, the socket is not usable anymore thus closing it and
  67                  * setting the file descriptor to -1 so it is not reused.
  68                  */
  69
  70                 /* This call will PERROR on error. */
  71                 (void) lttcomm_close_unix_sock(fd);
  72                 *socket->fd_ptr = -1;
  73                 goto error;
  74         }
  75
  76         return 0;
  77
  78 error:
  79         return -1;
  80 }
  81
  82 /*
  83  * Receive a data payload using a given consumer socket of size len.
  84  *
  85  * The consumer socket lock MUST be acquired before calling this since this
  86  * function can change the fd value.
  87  *
  88  * Return 0 on success else a negative value on error.
  89  */
  90 int consumer_socket_recv(struct consumer_socket *socket, void *msg, size_t len)
  91 {
  92         int fd;
  93         ssize_t size;
  94
  95         assert(socket);
  96         assert(socket->fd_ptr);
  97         assert(msg);
  98
  99         /* Consumer socket is invalid. Stopping. */
 100         fd = *socket->fd_ptr;
 101         if (fd < 0) {
 102                 goto error;
 103         }
 104
 105         size = lttcomm_recv_unix_sock(fd, msg, len);
 106         if (size <= 0) {
 107                 /* The above call will print a PERROR on error. */
 108                 DBG("Error when receiving data from the consumer socket %d", fd);
 109                 /*
 110                  * At this point, the socket is not usable anymore thus closing it and
 111                  * setting the file descriptor to -1 so it is not reused.
 112                  */
 113
 114                 /* This call will PERROR on error. */
 115                 (void) lttcomm_close_unix_sock(fd);
 116                 *socket->fd_ptr = -1;
 117                 goto error;
 118         }
 119
 120         return 0;
 121
 122 error:
 123         return -1;
 124 }
 125
 126 /*
 127  * Receive a reply command status message from the consumer. Consumer socket
 128  * lock MUST be acquired before calling this function.
 129  *
 130  * Return 0 on success, -1 on recv error or a negative lttng error code which
 131  * was possibly returned by the consumer.
 132  */
 133 int consumer_recv_status_reply(struct consumer_socket *sock)
 134 {
 135         int ret;
 136         struct lttcomm_consumer_status_msg reply;
 137
 138         assert(sock);
 139
 140         ret = consumer_socket_recv(sock, &reply, sizeof(reply));
 141         if (ret < 0) {
 142                 goto end;
 143         }
 144
 145         if (reply.ret_code == LTTCOMM_CONSUMERD_SUCCESS) {
 146                 /* All good. */
 147                 ret = 0;
 148         } else {
 149                 ret = -reply.ret_code;
 150                 DBG("Consumer ret code %d", ret);
 151         }
 152
 153 end:
 154         return ret;
 155 }
 156
 157 /*
 158  * Once the ASK_CHANNEL command is sent to the consumer, the channel
 159  * information are sent back. This call receives that data and populates key
 160  * and stream_count.
 161  *
 162  * On success return 0 and both key and stream_count are set. On error, a
 163  * negative value is sent back and both parameters are untouched.
 164  */
 165 int consumer_recv_status_channel(struct consumer_socket *sock,
 166                 uint64_t *key, unsigned int *stream_count)
 167 {
 168         int ret;
 169         struct lttcomm_consumer_status_channel reply;
 170
 171         assert(sock);
 172         assert(stream_count);
 173         assert(key);
 174
 175         ret = consumer_socket_recv(sock, &reply, sizeof(reply));
 176         if (ret < 0) {
 177                 goto end;
 178         }
 179
 180         /* An error is possible so don't touch the key and stream_count. */
 181         if (reply.ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
 182                 ret = -1;
 183                 goto end;
 184         }
 185
 186         *key = reply.key;
 187         *stream_count = reply.stream_count;
 188         ret = 0;
 189
 190 end:
 191         return ret;
 192 }
 193
 194 /*
 195  * Send destroy relayd command to consumer.
 196  *
 197  * On success return positive value. On error, negative value.
 198  */
 199 int consumer_send_destroy_relayd(struct consumer_socket *sock,
 200                 struct consumer_output *consumer)
 201 {
 202         int ret;
 203         struct lttcomm_consumer_msg msg;
 204
 205         assert(consumer);
 206         assert(sock);
 207
 208         DBG2("Sending destroy relayd command to consumer sock %d", *sock->fd_ptr);
 209
 210         memset(&msg, 0, sizeof(msg));
 211         msg.cmd_type = LTTNG_CONSUMER_DESTROY_RELAYD;
 212         msg.u.destroy_relayd.net_seq_idx = consumer->net_seq_index;
 213
 214         pthread_mutex_lock(sock->lock);
 215         ret = consumer_socket_send(sock, &msg, sizeof(msg));
 216         if (ret < 0) {
 217                 goto error;
 218         }
 219
 220         /* Don't check the return value. The caller will do it. */
 221         ret = consumer_recv_status_reply(sock);
 222
 223         DBG2("Consumer send destroy relayd command done");
 224
 225 error:
 226         pthread_mutex_unlock(sock->lock);
 227         return ret;
 228 }
 229
 230 /*
 231  * For each consumer socket in the consumer output object, send a destroy
 232  * relayd command.
 233  */
 234 void consumer_output_send_destroy_relayd(struct consumer_output *consumer)
 235 {
 236         struct lttng_ht_iter iter;
 237         struct consumer_socket *socket;
 238
 239         assert(consumer);
 240
 241         /* Destroy any relayd connection */
 242         if (consumer->type == CONSUMER_DST_NET) {
 243                 rcu_read_lock();
 244                 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
 245                                 node.node) {
 246                         int ret;
 247
 248                         /* Send destroy relayd command */
 249                         ret = consumer_send_destroy_relayd(socket, consumer);
 250                         if (ret < 0) {
 251                                 DBG("Unable to send destroy relayd command to consumer");
 252                                 /* Continue since we MUST delete everything at this point. */
 253                         }
 254                 }
 255                 rcu_read_unlock();
 256         }
 257 }
 258
 259 /*
 260  * From a consumer_data structure, allocate and add a consumer socket to the
 261  * consumer output.
 262  *
 263  * Return 0 on success, else negative value on error
 264  */
 265 int consumer_create_socket(struct consumer_data *data,
 266                 struct consumer_output *output)
 267 {
 268         int ret = 0;
 269         struct consumer_socket *socket;
 270
 271         assert(data);
 272
 273         if (output == NULL || data->cmd_sock < 0) {
 274                 /*
 275                  * Not an error. Possible there is simply not spawned consumer or it's
 276                  * disabled for the tracing session asking the socket.
 277                  */
 278                 goto error;
 279         }
 280
 281         rcu_read_lock();
 282         socket = consumer_find_socket(data->cmd_sock, output);
 283         rcu_read_unlock();
 284         if (socket == NULL) {
 285                 socket = consumer_allocate_socket(&data->cmd_sock);
 286                 if (socket == NULL) {
 287                         ret = -1;
 288                         goto error;
 289                 }
 290
 291                 socket->registered = 0;
 292                 socket->lock = &data->lock;
 293                 rcu_read_lock();
 294                 consumer_add_socket(socket, output);
 295                 rcu_read_unlock();
 296         }
 297
 298         socket->type = data->type;
 299
 300         DBG3("Consumer socket created (fd: %d) and added to output",
 301                         data->cmd_sock);
 302
 303 error:
 304         return ret;
 305 }
 306
 307 /*
 308  * Return the consumer socket from the given consumer output with the right
 309  * bitness. On error, returns NULL.
 310  *
 311  * The caller MUST acquire a rcu read side lock and keep it until the socket
 312  * object reference is not needed anymore.
 313  */
 314 struct consumer_socket *consumer_find_socket_by_bitness(int bits,
 315                 struct consumer_output *consumer)
 316 {
 317         int consumer_fd;
 318         struct consumer_socket *socket = NULL;
 319
 320         switch (bits) {
 321         case 64:
 322                 consumer_fd = uatomic_read(&ust_consumerd64_fd);
 323                 break;
 324         case 32:
 325                 consumer_fd = uatomic_read(&ust_consumerd32_fd);
 326                 break;
 327         default:
 328                 assert(0);
 329                 goto end;
 330         }
 331
 332         socket = consumer_find_socket(consumer_fd, consumer);
 333         if (!socket) {
 334                 ERR("Consumer socket fd %d not found in consumer obj %p",
 335                                 consumer_fd, consumer);
 336         }
 337
 338 end:
 339         return socket;
 340 }
 341
 342 /*
 343  * Find a consumer_socket in a consumer_output hashtable. Read side lock must
 344  * be acquired before calling this function and across use of the
 345  * returned consumer_socket.
 346  */
 347 struct consumer_socket *consumer_find_socket(int key,
 348                 struct consumer_output *consumer)
 349 {
 350         struct lttng_ht_iter iter;
 351         struct lttng_ht_node_ulong *node;
 352         struct consumer_socket *socket = NULL;
 353
 354         /* Negative keys are lookup failures */
 355         if (key < 0 || consumer == NULL) {
 356                 return NULL;
 357         }
 358
 359         lttng_ht_lookup(consumer->socks, (void *)((unsigned long) key),
 360                         &iter);
 361         node = lttng_ht_iter_get_node_ulong(&iter);
 362         if (node != NULL) {
 363                 socket = caa_container_of(node, struct consumer_socket, node);
 364         }
 365
 366         return socket;
 367 }
 368
 369 /*
 370  * Allocate a new consumer_socket and return the pointer.
 371  */
 372 struct consumer_socket *consumer_allocate_socket(int *fd)
 373 {
 374         struct consumer_socket *socket = NULL;
 375
 376         assert(fd);
 377
 378         socket = zmalloc(sizeof(struct consumer_socket));
 379         if (socket == NULL) {
 380                 PERROR("zmalloc consumer socket");
 381                 goto error;
 382         }
 383
 384         socket->fd_ptr = fd;
 385         lttng_ht_node_init_ulong(&socket->node, *fd);
 386
 387 error:
 388         return socket;
 389 }
 390
 391 /*
 392  * Add consumer socket to consumer output object. Read side lock must be
 393  * acquired before calling this function.
 394  */
 395 void consumer_add_socket(struct consumer_socket *sock,
 396                 struct consumer_output *consumer)
 397 {
 398         assert(sock);
 399         assert(consumer);
 400
 401         lttng_ht_add_unique_ulong(consumer->socks, &sock->node);
 402 }
 403
 404 /*
 405  * Delte consumer socket to consumer output object. Read side lock must be
 406  * acquired before calling this function.
 407  */
 408 void consumer_del_socket(struct consumer_socket *sock,
 409                 struct consumer_output *consumer)
 410 {
 411         int ret;
 412         struct lttng_ht_iter iter;
 413
 414         assert(sock);
 415         assert(consumer);
 416
 417         iter.iter.node = &sock->node.node;
 418         ret = lttng_ht_del(consumer->socks, &iter);
 419         assert(!ret);
 420 }
 421
 422 /*
 423  * RCU destroy call function.
 424  */
 425 static void destroy_socket_rcu(struct rcu_head *head)
 426 {
 427         struct lttng_ht_node_ulong *node =
 428                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 429         struct consumer_socket *socket =
 430                 caa_container_of(node, struct consumer_socket, node);
 431
 432         free(socket);
 433 }
 434
 435 /*
 436  * Destroy and free socket pointer in a call RCU. Read side lock must be
 437  * acquired before calling this function.
 438  */
 439 void consumer_destroy_socket(struct consumer_socket *sock)
 440 {
 441         assert(sock);
 442
 443         /*
 444          * We DO NOT close the file descriptor here since it is global to the
 445          * session daemon and is closed only if the consumer dies or a custom
 446          * consumer was registered,
 447          */
 448         if (sock->registered) {
 449                 DBG3("Consumer socket was registered. Closing fd %d", *sock->fd_ptr);
 450                 lttcomm_close_unix_sock(*sock->fd_ptr);
 451         }
 452
 453         call_rcu(&sock->node.head, destroy_socket_rcu);
 454 }
 455
 456 /*
 457  * Allocate and assign data to a consumer_output object.
 458  *
 459  * Return pointer to structure.
 460  */
 461 struct consumer_output *consumer_create_output(enum consumer_dst_type type)
 462 {
 463         struct consumer_output *output = NULL;
 464
 465         output = zmalloc(sizeof(struct consumer_output));
 466         if (output == NULL) {
 467                 PERROR("zmalloc consumer_output");
 468                 goto error;
 469         }
 470
 471         /* By default, consumer output is enabled */
 472         output->enabled = 1;
 473         output->type = type;
 474         output->net_seq_index = (uint64_t) -1ULL;
 475         urcu_ref_init(&output->ref);
 476
 477         output->socks = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 478
 479 error:
 480         return output;
 481 }
 482
 483 /*
 484  * Iterate over the consumer output socket hash table and destroy them. The
 485  * socket file descriptor are only closed if the consumer output was
 486  * registered meaning it's an external consumer.
 487  */
 488 void consumer_destroy_output_sockets(struct consumer_output *obj)
 489 {
 490         struct lttng_ht_iter iter;
 491         struct consumer_socket *socket;
 492
 493         if (!obj->socks) {
 494                 return;
 495         }
 496
 497         rcu_read_lock();
 498         cds_lfht_for_each_entry(obj->socks->ht, &iter.iter, socket, node.node) {
 499                 consumer_del_socket(socket, obj);
 500                 consumer_destroy_socket(socket);
 501         }
 502         rcu_read_unlock();
 503 }
 504
 505 /*
 506  * Delete the consumer_output object from the list and free the ptr.
 507  *
 508  * Should *NOT* be called with RCU read-side lock held.
 509  */
 510 static void consumer_release_output(struct urcu_ref *ref)
 511 {
 512         struct consumer_output *obj =
 513                 caa_container_of(ref, struct consumer_output, ref);
 514
 515         consumer_destroy_output_sockets(obj);
 516
 517         if (obj->socks) {
 518                 /* Finally destroy HT */
 519                 ht_cleanup_push(obj->socks);
 520         }
 521
 522         free(obj);
 523 }
 524
 525 /*
 526  * Get the consumer_output object.
 527  */
 528 void consumer_output_get(struct consumer_output *obj)
 529 {
 530         urcu_ref_get(&obj->ref);
 531 }
 532
 533 /*
 534  * Put the consumer_output object.
 535  *
 536  * Should *NOT* be called with RCU read-side lock held.
 537  */
 538 void consumer_output_put(struct consumer_output *obj)
 539 {
 540         if (!obj) {
 541                 return;
 542         }
 543         urcu_ref_put(&obj->ref, consumer_release_output);
 544 }
 545
 546 /*
 547  * Copy consumer output and returned the newly allocated copy.
 548  *
 549  * Should *NOT* be called with RCU read-side lock held.
 550  */
 551 struct consumer_output *consumer_copy_output(struct consumer_output *obj)
 552 {
 553         int ret;
 554         struct consumer_output *output;
 555
 556         assert(obj);
 557
 558         output = consumer_create_output(obj->type);
 559         if (output == NULL) {
 560                 goto end;
 561         }
 562         output->enabled = obj->enabled;
 563         output->net_seq_index = obj->net_seq_index;
 564         memcpy(output->subdir, obj->subdir, PATH_MAX);
 565         output->snapshot = obj->snapshot;
 566         output->relay_major_version = obj->relay_major_version;
 567         output->relay_minor_version = obj->relay_minor_version;
 568         memcpy(&output->dst, &obj->dst, sizeof(output->dst));
 569         ret = consumer_copy_sockets(output, obj);
 570         if (ret < 0) {
 571                 goto error_put;
 572         }
 573 end:
 574         return output;
 575
 576 error_put:
 577         consumer_output_put(output);
 578         return NULL;
 579 }
 580
 581 /*
 582  * Copy consumer sockets from src to dst.
 583  *
 584  * Return 0 on success or else a negative value.
 585  */
 586 int consumer_copy_sockets(struct consumer_output *dst,
 587                 struct consumer_output *src)
 588 {
 589         int ret = 0;
 590         struct lttng_ht_iter iter;
 591         struct consumer_socket *socket, *copy_sock;
 592
 593         assert(dst);
 594         assert(src);
 595
 596         rcu_read_lock();
 597         cds_lfht_for_each_entry(src->socks->ht, &iter.iter, socket, node.node) {
 598                 /* Ignore socket that are already there. */
 599                 copy_sock = consumer_find_socket(*socket->fd_ptr, dst);
 600                 if (copy_sock) {
 601                         continue;
 602                 }
 603
 604                 /* Create new socket object. */
 605                 copy_sock = consumer_allocate_socket(socket->fd_ptr);
 606                 if (copy_sock == NULL) {
 607                         rcu_read_unlock();
 608                         ret = -ENOMEM;
 609                         goto error;
 610                 }
 611
 612                 copy_sock->registered = socket->registered;
 613                 /*
 614                  * This is valid because this lock is shared accross all consumer
 615                  * object being the global lock of the consumer data structure of the
 616                  * session daemon.
 617                  */
 618                 copy_sock->lock = socket->lock;
 619                 consumer_add_socket(copy_sock, dst);
 620         }
 621         rcu_read_unlock();
 622
 623 error:
 624         return ret;
 625 }
 626
 627 /*
 628  * Set network URI to the consumer output object.
 629  *
 630  * Return 0 on success. Return 1 if the URI were equal. Else, negative value on
 631  * error.
 632  */
 633 int consumer_set_network_uri(struct consumer_output *obj,
 634                 struct lttng_uri *uri)
 635 {
 636         int ret;
 637         char tmp_path[PATH_MAX];
 638         char hostname[HOST_NAME_MAX];
 639         struct lttng_uri *dst_uri = NULL;
 640
 641         /* Code flow error safety net. */
 642         assert(obj);
 643         assert(uri);
 644
 645         switch (uri->stype) {
 646         case LTTNG_STREAM_CONTROL:
 647                 dst_uri = &obj->dst.net.control;
 648                 obj->dst.net.control_isset = 1;
 649                 if (uri->port == 0) {
 650                         /* Assign default port. */
 651                         uri->port = DEFAULT_NETWORK_CONTROL_PORT;
 652                 } else {
 653                         if (obj->dst.net.data_isset && uri->port ==
 654                                         obj->dst.net.data.port) {
 655                                 ret = -LTTNG_ERR_INVALID;
 656                                 goto error;
 657                         }
 658                 }
 659                 DBG3("Consumer control URI set with port %d", uri->port);
 660                 break;
 661         case LTTNG_STREAM_DATA:
 662                 dst_uri = &obj->dst.net.data;
 663                 obj->dst.net.data_isset = 1;
 664                 if (uri->port == 0) {
 665                         /* Assign default port. */
 666                         uri->port = DEFAULT_NETWORK_DATA_PORT;
 667                 } else {
 668                         if (obj->dst.net.control_isset && uri->port ==
 669                                         obj->dst.net.control.port) {
 670                                 ret = -LTTNG_ERR_INVALID;
 671                                 goto error;
 672                         }
 673                 }
 674                 DBG3("Consumer data URI set with port %d", uri->port);
 675                 break;
 676         default:
 677                 ERR("Set network uri type unknown %d", uri->stype);
 678                 ret = -LTTNG_ERR_INVALID;
 679                 goto error;
 680         }
 681
 682         ret = uri_compare(dst_uri, uri);
 683         if (!ret) {
 684                 /* Same URI, don't touch it and return success. */
 685                 DBG3("URI network compare are the same");
 686                 goto equal;
 687         }
 688
 689         /* URIs were not equal, replacing it. */
 690         memset(dst_uri, 0, sizeof(struct lttng_uri));
 691         memcpy(dst_uri, uri, sizeof(struct lttng_uri));
 692         obj->type = CONSUMER_DST_NET;
 693
 694         /* Handle subdir and add hostname in front. */
 695         if (dst_uri->stype == LTTNG_STREAM_CONTROL) {
 696                 /* Get hostname to append it in the pathname */
 697                 ret = gethostname(hostname, sizeof(hostname));
 698                 if (ret < 0) {
 699                         PERROR("gethostname. Fallback on default localhost");
 700                         strncpy(hostname, "localhost", sizeof(hostname));
 701                 }
 702                 hostname[sizeof(hostname) - 1] = '\0';
 703
 704                 /* Setup consumer subdir if none present in the control URI */
 705                 if (strlen(dst_uri->subdir) == 0) {
 706                         ret = snprintf(tmp_path, sizeof(tmp_path), "%s/%s",
 707                                         hostname, obj->subdir);
 708                 } else {
 709                         ret = snprintf(tmp_path, sizeof(tmp_path), "%s/%s",
 710                                         hostname, dst_uri->subdir);
 711                 }
 712                 if (ret < 0) {
 713                         PERROR("snprintf set consumer uri subdir");
 714                         ret = -LTTNG_ERR_NOMEM;
 715                         goto error;
 716                 }
 717
 718                 if (lttng_strncpy(obj->subdir, tmp_path, sizeof(obj->subdir))) {
 719                         ret = -LTTNG_ERR_INVALID;
 720                         goto error;
 721                 }
 722                 DBG3("Consumer set network uri subdir path %s", tmp_path);
 723         }
 724
 725         return 0;
 726 equal:
 727         return 1;
 728 error:
 729         return ret;
 730 }
 731
 732 /*
 733  * Send file descriptor to consumer via sock.
 734  */
 735 int consumer_send_fds(struct consumer_socket *sock, int *fds, size_t nb_fd)
 736 {
 737         int ret;
 738
 739         assert(fds);
 740         assert(sock);
 741         assert(nb_fd > 0);
 742         assert(pthread_mutex_trylock(sock->lock) == EBUSY);
 743
 744         ret = lttcomm_send_fds_unix_sock(*sock->fd_ptr, fds, nb_fd);
 745         if (ret < 0) {
 746                 /* The above call will print a PERROR on error. */
 747                 DBG("Error when sending consumer fds on sock %d", *sock->fd_ptr);
 748                 goto error;
 749         }
 750
 751         ret = consumer_recv_status_reply(sock);
 752
 753 error:
 754         return ret;
 755 }
 756
 757 /*
 758  * Consumer send communication message structure to consumer.
 759  */
 760 int consumer_send_msg(struct consumer_socket *sock,
 761                 struct lttcomm_consumer_msg *msg)
 762 {
 763         int ret;
 764
 765         assert(msg);
 766         assert(sock);
 767         assert(pthread_mutex_trylock(sock->lock) == EBUSY);
 768
 769         ret = consumer_socket_send(sock, msg, sizeof(struct lttcomm_consumer_msg));
 770         if (ret < 0) {
 771                 goto error;
 772         }
 773
 774         ret = consumer_recv_status_reply(sock);
 775
 776 error:
 777         return ret;
 778 }
 779
 780 /*
 781  * Consumer send channel communication message structure to consumer.
 782  */
 783 int consumer_send_channel(struct consumer_socket *sock,
 784                 struct lttcomm_consumer_msg *msg)
 785 {
 786         int ret;
 787
 788         assert(msg);
 789         assert(sock);
 790
 791         ret = consumer_send_msg(sock, msg);
 792         if (ret < 0) {
 793                 goto error;
 794         }
 795
 796 error:
 797         return ret;
 798 }
 799
 800 /*
 801  * Populate the given consumer msg structure with the ask_channel command
 802  * information.
 803  */
 804 void consumer_init_ask_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 805                 uint64_t subbuf_size,
 806                 uint64_t num_subbuf,
 807                 int overwrite,
 808                 unsigned int switch_timer_interval,
 809                 unsigned int read_timer_interval,
 810                 unsigned int live_timer_interval,
 811                 int output,
 812                 int type,
 813                 uint64_t session_id,
 814                 const char *pathname,
 815                 const char *name,
 816                 uid_t uid,
 817                 gid_t gid,
 818                 uint64_t relayd_id,
 819                 uint64_t key,
 820                 unsigned char *uuid,
 821                 uint32_t chan_id,
 822                 uint64_t tracefile_size,
 823                 uint64_t tracefile_count,
 824                 uint64_t session_id_per_pid,
 825                 unsigned int monitor,
 826                 uint32_t ust_app_uid,
 827                 const char *root_shm_path,
 828                 const char *shm_path)
 829 {
 830         assert(msg);
 831
 832         /* Zeroed structure */
 833         memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
 834
 835         msg->cmd_type = LTTNG_CONSUMER_ASK_CHANNEL_CREATION;
 836         msg->u.ask_channel.subbuf_size = subbuf_size;
 837         msg->u.ask_channel.num_subbuf = num_subbuf ;
 838         msg->u.ask_channel.overwrite = overwrite;
 839         msg->u.ask_channel.switch_timer_interval = switch_timer_interval;
 840         msg->u.ask_channel.read_timer_interval = read_timer_interval;
 841         msg->u.ask_channel.live_timer_interval = live_timer_interval;
 842         msg->u.ask_channel.output = output;
 843         msg->u.ask_channel.type = type;
 844         msg->u.ask_channel.session_id = session_id;
 845         msg->u.ask_channel.session_id_per_pid = session_id_per_pid;
 846         msg->u.ask_channel.uid = uid;
 847         msg->u.ask_channel.gid = gid;
 848         msg->u.ask_channel.relayd_id = relayd_id;
 849         msg->u.ask_channel.key = key;
 850         msg->u.ask_channel.chan_id = chan_id;
 851         msg->u.ask_channel.tracefile_size = tracefile_size;
 852         msg->u.ask_channel.tracefile_count = tracefile_count;
 853         msg->u.ask_channel.monitor = monitor;
 854         msg->u.ask_channel.ust_app_uid = ust_app_uid;
 855
 856         memcpy(msg->u.ask_channel.uuid, uuid, sizeof(msg->u.ask_channel.uuid));
 857
 858         if (pathname) {
 859                 strncpy(msg->u.ask_channel.pathname, pathname,
 860                                 sizeof(msg->u.ask_channel.pathname));
 861                 msg->u.ask_channel.pathname[sizeof(msg->u.ask_channel.pathname)-1] = '\0';
 862         }
 863
 864         strncpy(msg->u.ask_channel.name, name, sizeof(msg->u.ask_channel.name));
 865         msg->u.ask_channel.name[sizeof(msg->u.ask_channel.name) - 1] = '\0';
 866
 867         if (root_shm_path) {
 868                 strncpy(msg->u.ask_channel.root_shm_path, root_shm_path,
 869                         sizeof(msg->u.ask_channel.root_shm_path));
 870                 msg->u.ask_channel.root_shm_path[sizeof(msg->u.ask_channel.root_shm_path) - 1] = '\0';
 871         }
 872         if (shm_path) {
 873                 strncpy(msg->u.ask_channel.shm_path, shm_path,
 874                         sizeof(msg->u.ask_channel.shm_path));
 875                 msg->u.ask_channel.shm_path[sizeof(msg->u.ask_channel.shm_path) - 1] = '\0';
 876         }
 877 }
 878
 879 /*
 880  * Init channel communication message structure.
 881  */
 882 void consumer_init_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 883                 enum lttng_consumer_command cmd,
 884                 uint64_t channel_key,
 885                 uint64_t session_id,
 886                 const char *pathname,
 887                 uid_t uid,
 888                 gid_t gid,
 889                 uint64_t relayd_id,
 890                 const char *name,
 891                 unsigned int nb_init_streams,
 892                 enum lttng_event_output output,
 893                 int type,
 894                 uint64_t tracefile_size,
 895                 uint64_t tracefile_count,
 896                 unsigned int monitor,
 897                 unsigned int live_timer_interval)
 898 {
 899         assert(msg);
 900
 901         /* Zeroed structure */
 902         memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
 903
 904         /* Send channel */
 905         msg->cmd_type = cmd;
 906         msg->u.channel.channel_key = channel_key;
 907         msg->u.channel.session_id = session_id;
 908         msg->u.channel.uid = uid;
 909         msg->u.channel.gid = gid;
 910         msg->u.channel.relayd_id = relayd_id;
 911         msg->u.channel.nb_init_streams = nb_init_streams;
 912         msg->u.channel.output = output;
 913         msg->u.channel.type = type;
 914         msg->u.channel.tracefile_size = tracefile_size;
 915         msg->u.channel.tracefile_count = tracefile_count;
 916         msg->u.channel.monitor = monitor;
 917         msg->u.channel.live_timer_interval = live_timer_interval;
 918
 919         strncpy(msg->u.channel.pathname, pathname,
 920                         sizeof(msg->u.channel.pathname));
 921         msg->u.channel.pathname[sizeof(msg->u.channel.pathname) - 1] = '\0';
 922
 923         strncpy(msg->u.channel.name, name, sizeof(msg->u.channel.name));
 924         msg->u.channel.name[sizeof(msg->u.channel.name) - 1] = '\0';
 925 }
 926
 927 /*
 928  * Init stream communication message structure.
 929  */
 930 void consumer_init_stream_comm_msg(struct lttcomm_consumer_msg *msg,
 931                 enum lttng_consumer_command cmd,
 932                 uint64_t channel_key,
 933                 uint64_t stream_key,
 934                 int cpu)
 935 {
 936         assert(msg);
 937
 938         memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
 939
 940         msg->cmd_type = cmd;
 941         msg->u.stream.channel_key = channel_key;
 942         msg->u.stream.stream_key = stream_key;
 943         msg->u.stream.cpu = cpu;
 944 }
 945
 946 void consumer_init_streams_sent_comm_msg(struct lttcomm_consumer_msg *msg,
 947                 enum lttng_consumer_command cmd,
 948                 uint64_t channel_key, uint64_t net_seq_idx)
 949 {
 950         assert(msg);
 951
 952         memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
 953
 954         msg->cmd_type = cmd;
 955         msg->u.sent_streams.channel_key = channel_key;
 956         msg->u.sent_streams.net_seq_idx = net_seq_idx;
 957 }
 958
 959 /*
 960  * Send stream communication structure to the consumer.
 961  */
 962 int consumer_send_stream(struct consumer_socket *sock,
 963                 struct consumer_output *dst, struct lttcomm_consumer_msg *msg,
 964                 int *fds, size_t nb_fd)
 965 {
 966         int ret;
 967
 968         assert(msg);
 969         assert(dst);
 970         assert(sock);
 971         assert(fds);
 972
 973         ret = consumer_send_msg(sock, msg);
 974         if (ret < 0) {
 975                 goto error;
 976         }
 977
 978         ret = consumer_send_fds(sock, fds, nb_fd);
 979         if (ret < 0) {
 980                 goto error;
 981         }
 982
 983 error:
 984         return ret;
 985 }
 986
 987 /*
 988  * Send relayd socket to consumer associated with a session name.
 989  *
 990  * The consumer socket lock must be held by the caller.
 991  *
 992  * On success return positive value. On error, negative value.
 993  */
 994 int consumer_send_relayd_socket(struct consumer_socket *consumer_sock,
 995                 struct lttcomm_relayd_sock *rsock, struct consumer_output *consumer,
 996                 enum lttng_stream_type type, uint64_t session_id,
 997                 char *session_name, char *hostname, int session_live_timer)
 998 {
 999         int ret;
1000         struct lttcomm_consumer_msg msg;
1001
1002         /* Code flow error. Safety net. */
1003         assert(rsock);
1004         assert(consumer);
1005         assert(consumer_sock);
1006
1007         memset(&msg, 0, sizeof(msg));
1008         /* Bail out if consumer is disabled */
1009         if (!consumer->enabled) {
1010                 ret = LTTNG_OK;
1011                 goto error;
1012         }
1013
1014         if (type == LTTNG_STREAM_CONTROL) {
1015                 ret = relayd_create_session(rsock,
1016                                 &msg.u.relayd_sock.relayd_session_id,
1017                                 session_name, hostname, session_live_timer,
1018                                 consumer->snapshot);
1019                 if (ret < 0) {
1020                         /* Close the control socket. */
1021                         (void) relayd_close(rsock);
1022                         goto error;
1023                 }
1024         }
1025
1026         msg.cmd_type = LTTNG_CONSUMER_ADD_RELAYD_SOCKET;
1027         /*
1028          * Assign network consumer output index using the temporary consumer since
1029          * this call should only be made from within a set_consumer_uri() function
1030          * call in the session daemon.
1031          */
1032         msg.u.relayd_sock.net_index = consumer->net_seq_index;
1033         msg.u.relayd_sock.type = type;
1034         msg.u.relayd_sock.session_id = session_id;
1035         memcpy(&msg.u.relayd_sock.sock, rsock, sizeof(msg.u.relayd_sock.sock));
1036
1037         DBG3("Sending relayd sock info to consumer on %d", *consumer_sock->fd_ptr);
1038         ret = consumer_send_msg(consumer_sock, &msg);
1039         if (ret < 0) {
1040                 goto error;
1041         }
1042
1043         DBG3("Sending relayd socket file descriptor to consumer");
1044         ret = consumer_send_fds(consumer_sock, &rsock->sock.fd, 1);
1045         if (ret < 0) {
1046                 goto error;
1047         }
1048
1049         DBG2("Consumer relayd socket sent");
1050
1051 error:
1052         return ret;
1053 }
1054
1055 /*
1056  * Set consumer subdirectory using the session name and a generated datetime if
1057  * needed. This is appended to the current subdirectory.
1058  */
1059 int consumer_set_subdir(struct consumer_output *consumer,
1060                 const char *session_name)
1061 {
1062         int ret = 0;
1063         unsigned int have_default_name = 0;
1064         char datetime[16], tmp_path[PATH_MAX];
1065         time_t rawtime;
1066         struct tm *timeinfo;
1067
1068         assert(consumer);
1069         assert(session_name);
1070
1071         memset(tmp_path, 0, sizeof(tmp_path));
1072
1073         /* Flag if we have a default session. */
1074         if (strncmp(session_name, DEFAULT_SESSION_NAME "-",
1075                                 strlen(DEFAULT_SESSION_NAME) + 1) == 0) {
1076                 have_default_name = 1;
1077         } else {
1078                 /* Get date and time for session path */
1079                 time(&rawtime);
1080                 timeinfo = localtime(&rawtime);
1081                 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1082         }
1083
1084         if (have_default_name) {
1085                 ret = snprintf(tmp_path, sizeof(tmp_path),
1086                                 "%s/%s", consumer->subdir, session_name);
1087         } else {
1088                 ret = snprintf(tmp_path, sizeof(tmp_path),
1089                                 "%s/%s-%s/", consumer->subdir, session_name, datetime);
1090         }
1091         if (ret < 0) {
1092                 PERROR("snprintf session name date");
1093                 goto error;
1094         }
1095
1096         if (lttng_strncpy(consumer->subdir, tmp_path,
1097                         sizeof(consumer->subdir))) {
1098                 ret = -EINVAL;
1099                 goto error;
1100         }
1101         DBG2("Consumer subdir set to %s", consumer->subdir);
1102
1103 error:
1104         return ret;
1105 }
1106
1107 /*
1108  * Ask the consumer if the data is pending for the specific session id.
1109  * Returns 1 if data is pending, 0 otherwise, or < 0 on error.
1110  */
1111 int consumer_is_data_pending(uint64_t session_id,
1112                 struct consumer_output *consumer)
1113 {
1114         int ret;
1115         int32_t ret_code = 0;  /* Default is that the data is NOT pending */
1116         struct consumer_socket *socket;
1117         struct lttng_ht_iter iter;
1118         struct lttcomm_consumer_msg msg;
1119
1120         assert(consumer);
1121
1122         DBG3("Consumer data pending for id %" PRIu64, session_id);
1123
1124         memset(&msg, 0, sizeof(msg));
1125         msg.cmd_type = LTTNG_CONSUMER_DATA_PENDING;
1126         msg.u.data_pending.session_id = session_id;
1127
1128         /* Send command for each consumer */
1129         rcu_read_lock();
1130         cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
1131                         node.node) {
1132                 pthread_mutex_lock(socket->lock);
1133                 ret = consumer_socket_send(socket, &msg, sizeof(msg));
1134                 if (ret < 0) {
1135                         pthread_mutex_unlock(socket->lock);
1136                         goto error_unlock;
1137                 }
1138
1139                 /*
1140                  * No need for a recv reply status because the answer to the command is
1141                  * the reply status message.
1142                  */
1143
1144                 ret = consumer_socket_recv(socket, &ret_code, sizeof(ret_code));
1145                 if (ret < 0) {
1146                         pthread_mutex_unlock(socket->lock);
1147                         goto error_unlock;
1148                 }
1149                 pthread_mutex_unlock(socket->lock);
1150
1151                 if (ret_code == 1) {
1152                         break;
1153                 }
1154         }
1155         rcu_read_unlock();
1156
1157         DBG("Consumer data is %s pending for session id %" PRIu64,
1158                         ret_code == 1 ? "" : "NOT", session_id);
1159         return ret_code;
1160
1161 error_unlock:
1162         rcu_read_unlock();
1163         return -1;
1164 }
1165
1166 /*
1167  * Send a flush command to consumer using the given channel key.
1168  *
1169  * Return 0 on success else a negative value.
1170  */
1171 int consumer_flush_channel(struct consumer_socket *socket, uint64_t key)
1172 {
1173         int ret;
1174         struct lttcomm_consumer_msg msg;
1175
1176         assert(socket);
1177
1178         DBG2("Consumer flush channel key %" PRIu64, key);
1179
1180         memset(&msg, 0, sizeof(msg));
1181         msg.cmd_type = LTTNG_CONSUMER_FLUSH_CHANNEL;
1182         msg.u.flush_channel.key = key;
1183
1184         pthread_mutex_lock(socket->lock);
1185         health_code_update();
1186
1187         ret = consumer_send_msg(socket, &msg);
1188         if (ret < 0) {
1189                 goto end;
1190         }
1191
1192 end:
1193         health_code_update();
1194         pthread_mutex_unlock(socket->lock);
1195         return ret;
1196 }
1197
1198 /*
1199  * Send a clear quiescent command to consumer using the given channel key.
1200  *
1201  * Return 0 on success else a negative value.
1202  */
1203 int consumer_clear_quiescent_channel(struct consumer_socket *socket, uint64_t key)
1204 {
1205         int ret;
1206         struct lttcomm_consumer_msg msg;
1207
1208         assert(socket);
1209
1210         DBG2("Consumer clear quiescent channel key %" PRIu64, key);
1211
1212         memset(&msg, 0, sizeof(msg));
1213         msg.cmd_type = LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL;
1214         msg.u.clear_quiescent_channel.key = key;
1215
1216         pthread_mutex_lock(socket->lock);
1217         health_code_update();
1218
1219         ret = consumer_send_msg(socket, &msg);
1220         if (ret < 0) {
1221                 goto end;
1222         }
1223
1224 end:
1225         health_code_update();
1226         pthread_mutex_unlock(socket->lock);
1227         return ret;
1228 }
1229
1230 /*
1231  * Send a close metadata command to consumer using the given channel key.
1232  * Called with registry lock held.
1233  *
1234  * Return 0 on success else a negative value.
1235  */
1236 int consumer_close_metadata(struct consumer_socket *socket,
1237                 uint64_t metadata_key)
1238 {
1239         int ret;
1240         struct lttcomm_consumer_msg msg;
1241
1242         assert(socket);
1243
1244         DBG2("Consumer close metadata channel key %" PRIu64, metadata_key);
1245
1246         memset(&msg, 0, sizeof(msg));
1247         msg.cmd_type = LTTNG_CONSUMER_CLOSE_METADATA;
1248         msg.u.close_metadata.key = metadata_key;
1249
1250         pthread_mutex_lock(socket->lock);
1251         health_code_update();
1252
1253         ret = consumer_send_msg(socket, &msg);
1254         if (ret < 0) {
1255                 goto end;
1256         }
1257
1258 end:
1259         health_code_update();
1260         pthread_mutex_unlock(socket->lock);
1261         return ret;
1262 }
1263
1264 /*
1265  * Send a setup metdata command to consumer using the given channel key.
1266  *
1267  * Return 0 on success else a negative value.
1268  */
1269 int consumer_setup_metadata(struct consumer_socket *socket,
1270                 uint64_t metadata_key)
1271 {
1272         int ret;
1273         struct lttcomm_consumer_msg msg;
1274
1275         assert(socket);
1276
1277         DBG2("Consumer setup metadata channel key %" PRIu64, metadata_key);
1278
1279         memset(&msg, 0, sizeof(msg));
1280         msg.cmd_type = LTTNG_CONSUMER_SETUP_METADATA;
1281         msg.u.setup_metadata.key = metadata_key;
1282
1283         pthread_mutex_lock(socket->lock);
1284         health_code_update();
1285
1286         ret = consumer_send_msg(socket, &msg);
1287         if (ret < 0) {
1288                 goto end;
1289         }
1290
1291 end:
1292         health_code_update();
1293         pthread_mutex_unlock(socket->lock);
1294         return ret;
1295 }
1296
1297 /*
1298  * Send metadata string to consumer.
1299  * RCU read-side lock must be held to guarantee existence of socket.
1300  *
1301  * Return 0 on success else a negative value.
1302  */
1303 int consumer_push_metadata(struct consumer_socket *socket,
1304                 uint64_t metadata_key, char *metadata_str, size_t len,
1305                 size_t target_offset, uint64_t version)
1306 {
1307         int ret;
1308         struct lttcomm_consumer_msg msg;
1309
1310         assert(socket);
1311
1312         DBG2("Consumer push metadata to consumer socket %d", *socket->fd_ptr);
1313
1314         pthread_mutex_lock(socket->lock);
1315
1316         memset(&msg, 0, sizeof(msg));
1317         msg.cmd_type = LTTNG_CONSUMER_PUSH_METADATA;
1318         msg.u.push_metadata.key = metadata_key;
1319         msg.u.push_metadata.target_offset = target_offset;
1320         msg.u.push_metadata.len = len;
1321         msg.u.push_metadata.version = version;
1322
1323         health_code_update();
1324         ret = consumer_send_msg(socket, &msg);
1325         if (ret < 0 || len == 0) {
1326                 goto end;
1327         }
1328
1329         DBG3("Consumer pushing metadata on sock %d of len %zu", *socket->fd_ptr,
1330                         len);
1331
1332         ret = consumer_socket_send(socket, metadata_str, len);
1333         if (ret < 0) {
1334                 goto end;
1335         }
1336
1337         health_code_update();
1338         ret = consumer_recv_status_reply(socket);
1339         if (ret < 0) {
1340                 goto end;
1341         }
1342
1343 end:
1344         pthread_mutex_unlock(socket->lock);
1345         health_code_update();
1346         return ret;
1347 }
1348
1349 /*
1350  * Ask the consumer to snapshot a specific channel using the key.
1351  *
1352  * Return 0 on success or else a negative error.
1353  */
1354 int consumer_snapshot_channel(struct consumer_socket *socket, uint64_t key,
1355                 struct snapshot_output *output, int metadata, uid_t uid, gid_t gid,
1356                 const char *session_path, int wait, uint64_t nb_packets_per_stream)
1357 {
1358         int ret;
1359         struct lttcomm_consumer_msg msg;
1360
1361         assert(socket);
1362         assert(output);
1363         assert(output->consumer);
1364
1365         DBG("Consumer snapshot channel key %" PRIu64, key);
1366
1367         memset(&msg, 0, sizeof(msg));
1368         msg.cmd_type = LTTNG_CONSUMER_SNAPSHOT_CHANNEL;
1369         msg.u.snapshot_channel.key = key;
1370         msg.u.snapshot_channel.nb_packets_per_stream = nb_packets_per_stream;
1371         msg.u.snapshot_channel.metadata = metadata;
1372
1373         if (output->consumer->type == CONSUMER_DST_NET) {
1374                 msg.u.snapshot_channel.relayd_id = output->consumer->net_seq_index;
1375                 msg.u.snapshot_channel.use_relayd = 1;
1376                 ret = snprintf(msg.u.snapshot_channel.pathname,
1377                                 sizeof(msg.u.snapshot_channel.pathname),
1378                                 "%s/%s-%s-%" PRIu64 "%s", output->consumer->subdir,
1379                                 output->name, output->datetime, output->nb_snapshot,
1380                                 session_path);
1381                 if (ret < 0) {
1382                         ret = -LTTNG_ERR_NOMEM;
1383                         goto error;
1384                 }
1385         } else {
1386                 ret = snprintf(msg.u.snapshot_channel.pathname,
1387                                 sizeof(msg.u.snapshot_channel.pathname),
1388                                 "%s/%s-%s-%" PRIu64 "%s", output->consumer->dst.trace_path,
1389                                 output->name, output->datetime, output->nb_snapshot,
1390                                 session_path);
1391                 if (ret < 0) {
1392                         ret = -LTTNG_ERR_NOMEM;
1393                         goto error;
1394                 }
1395                 msg.u.snapshot_channel.relayd_id = (uint64_t) -1ULL;
1396
1397                 /* Create directory. Ignore if exist. */
1398                 ret = run_as_mkdir_recursive(msg.u.snapshot_channel.pathname,
1399                                 S_IRWXU | S_IRWXG, uid, gid);
1400                 if (ret < 0) {
1401                         if (errno != EEXIST) {
1402                                 ERR("Trace directory creation error");
1403                                 goto error;
1404                         }
1405                 }
1406         }
1407
1408         health_code_update();
1409         ret = consumer_send_msg(socket, &msg);
1410         if (ret < 0) {
1411                 goto error;
1412         }
1413
1414 error:
1415         health_code_update();
1416         return ret;
1417 }
1418
1419 /*
1420  * Ask the consumer the number of discarded events for a channel.
1421  */
1422 int consumer_get_discarded_events(uint64_t session_id, uint64_t channel_key,
1423                 struct consumer_output *consumer, uint64_t *discarded)
1424 {
1425         int ret;
1426         struct consumer_socket *socket;
1427         struct lttng_ht_iter iter;
1428         struct lttcomm_consumer_msg msg;
1429
1430         assert(consumer);
1431
1432         DBG3("Consumer discarded events id %" PRIu64, session_id);
1433
1434         memset(&msg, 0, sizeof(msg));
1435         msg.cmd_type = LTTNG_CONSUMER_DISCARDED_EVENTS;
1436         msg.u.discarded_events.session_id = session_id;
1437         msg.u.discarded_events.channel_key = channel_key;
1438
1439         *discarded = 0;
1440
1441         /* Send command for each consumer */
1442         rcu_read_lock();
1443         cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
1444                         node.node) {
1445                 uint64_t consumer_discarded = 0;
1446                 pthread_mutex_lock(socket->lock);
1447                 ret = consumer_socket_send(socket, &msg, sizeof(msg));
1448                 if (ret < 0) {
1449                         pthread_mutex_unlock(socket->lock);
1450                         goto end;
1451                 }
1452
1453                 /*
1454                  * No need for a recv reply status because the answer to the
1455                  * command is the reply status message.
1456                  */
1457                 ret = consumer_socket_recv(socket, &consumer_discarded,
1458                                 sizeof(consumer_discarded));
1459                 if (ret < 0) {
1460                         ERR("get discarded events");
1461                         pthread_mutex_unlock(socket->lock);
1462                         goto end;
1463                 }
1464                 pthread_mutex_unlock(socket->lock);
1465                 *discarded += consumer_discarded;
1466         }
1467         ret = 0;
1468         DBG("Consumer discarded %" PRIu64 " events in session id %" PRIu64,
1469                         *discarded, session_id);
1470
1471 end:
1472         rcu_read_unlock();
1473         return ret;
1474 }
1475
1476 /*
1477  * Ask the consumer the number of lost packets for a channel.
1478  */
1479 int consumer_get_lost_packets(uint64_t session_id, uint64_t channel_key,
1480                 struct consumer_output *consumer, uint64_t *lost)
1481 {
1482         int ret;
1483         struct consumer_socket *socket;
1484         struct lttng_ht_iter iter;
1485         struct lttcomm_consumer_msg msg;
1486
1487         assert(consumer);
1488
1489         DBG3("Consumer lost packets id %" PRIu64, session_id);
1490
1491         memset(&msg, 0, sizeof(msg));
1492         msg.cmd_type = LTTNG_CONSUMER_LOST_PACKETS;
1493         msg.u.lost_packets.session_id = session_id;
1494         msg.u.lost_packets.channel_key = channel_key;
1495
1496         *lost = 0;
1497
1498         /* Send command for each consumer */
1499         rcu_read_lock();
1500         cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
1501                         node.node) {
1502                 uint64_t consumer_lost = 0;
1503                 pthread_mutex_lock(socket->lock);
1504                 ret = consumer_socket_send(socket, &msg, sizeof(msg));
1505                 if (ret < 0) {
1506                         pthread_mutex_unlock(socket->lock);
1507                         goto end;
1508                 }
1509
1510                 /*
1511                  * No need for a recv reply status because the answer to the
1512                  * command is the reply status message.
1513                  */
1514                 ret = consumer_socket_recv(socket, &consumer_lost,
1515                                 sizeof(consumer_lost));
1516                 if (ret < 0) {
1517                         ERR("get lost packets");
1518                         pthread_mutex_unlock(socket->lock);
1519                         goto end;
1520                 }
1521                 pthread_mutex_unlock(socket->lock);
1522                 *lost += consumer_lost;
1523         }
1524         ret = 0;
1525         DBG("Consumer lost %" PRIu64 " packets in session id %" PRIu64,
1526                         *lost, session_id);
1527
1528 end:
1529         rcu_read_unlock();
1530         return ret;
1531 }