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  * The consumer socket lock must be held by the caller.
 736  */
 737 int consumer_send_fds(struct consumer_socket *sock, int *fds, size_t nb_fd)
 738 {
 739         int ret;
 740
 741         assert(fds);
 742         assert(sock);
 743         assert(nb_fd > 0);
 744         assert(pthread_mutex_trylock(sock->lock) == EBUSY);
 745
 746         ret = lttcomm_send_fds_unix_sock(*sock->fd_ptr, fds, nb_fd);
 747         if (ret < 0) {
 748                 /* The above call will print a PERROR on error. */
 749                 DBG("Error when sending consumer fds on sock %d", *sock->fd_ptr);
 750                 goto error;
 751         }
 752
 753         ret = consumer_recv_status_reply(sock);
 754
 755 error:
 756         return ret;
 757 }
 758
 759 /*
 760  * Consumer send communication message structure to consumer.
 761  *
 762  * The consumer socket lock must be held by the caller.
 763  */
 764 int consumer_send_msg(struct consumer_socket *sock,
 765                 struct lttcomm_consumer_msg *msg)
 766 {
 767         int ret;
 768
 769         assert(msg);
 770         assert(sock);
 771         assert(pthread_mutex_trylock(sock->lock) == EBUSY);
 772
 773         ret = consumer_socket_send(sock, msg, sizeof(struct lttcomm_consumer_msg));
 774         if (ret < 0) {
 775                 goto error;
 776         }
 777
 778         ret = consumer_recv_status_reply(sock);
 779
 780 error:
 781         return ret;
 782 }
 783
 784 /*
 785  * Consumer send channel communication message structure to consumer.
 786  *
 787  * The consumer socket lock must be held by the caller.
 788  */
 789 int consumer_send_channel(struct consumer_socket *sock,
 790                 struct lttcomm_consumer_msg *msg)
 791 {
 792         int ret;
 793
 794         assert(msg);
 795         assert(sock);
 796
 797         ret = consumer_send_msg(sock, msg);
 798         if (ret < 0) {
 799                 goto error;
 800         }
 801
 802 error:
 803         return ret;
 804 }
 805
 806 /*
 807  * Populate the given consumer msg structure with the ask_channel command
 808  * information.
 809  */
 810 void consumer_init_ask_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 811                 uint64_t subbuf_size,
 812                 uint64_t num_subbuf,
 813                 int overwrite,
 814                 unsigned int switch_timer_interval,
 815                 unsigned int read_timer_interval,
 816                 unsigned int live_timer_interval,
 817                 bool is_in_live_session,
 818                 int output,
 819                 int type,
 820                 uint64_t session_id,
 821                 const char *pathname,
 822                 const char *name,
 823                 uid_t uid,
 824                 gid_t gid,
 825                 uint64_t relayd_id,
 826                 uint64_t key,
 827                 unsigned char *uuid,
 828                 uint32_t chan_id,
 829                 uint64_t tracefile_size,
 830                 uint64_t tracefile_count,
 831                 uint64_t session_id_per_pid,
 832                 unsigned int monitor,
 833                 uint32_t ust_app_uid,
 834                 const char *root_shm_path,
 835                 const char *shm_path)
 836 {
 837         assert(msg);
 838
 839         /* Zeroed structure */
 840         memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
 841
 842         msg->cmd_type = LTTNG_CONSUMER_ASK_CHANNEL_CREATION;
 843         msg->u.ask_channel.subbuf_size = subbuf_size;
 844         msg->u.ask_channel.num_subbuf = num_subbuf ;
 845         msg->u.ask_channel.overwrite = overwrite;
 846         msg->u.ask_channel.switch_timer_interval = switch_timer_interval;
 847         msg->u.ask_channel.read_timer_interval = read_timer_interval;
 848         msg->u.ask_channel.live_timer_interval = live_timer_interval;
 849         msg->u.ask_channel.is_live = is_in_live_session;
 850         msg->u.ask_channel.output = output;
 851         msg->u.ask_channel.type = type;
 852         msg->u.ask_channel.session_id = session_id;
 853         msg->u.ask_channel.session_id_per_pid = session_id_per_pid;
 854         msg->u.ask_channel.uid = uid;
 855         msg->u.ask_channel.gid = gid;
 856         msg->u.ask_channel.relayd_id = relayd_id;
 857         msg->u.ask_channel.key = key;
 858         msg->u.ask_channel.chan_id = chan_id;
 859         msg->u.ask_channel.tracefile_size = tracefile_size;
 860         msg->u.ask_channel.tracefile_count = tracefile_count;
 861         msg->u.ask_channel.monitor = monitor;
 862         msg->u.ask_channel.ust_app_uid = ust_app_uid;
 863
 864         memcpy(msg->u.ask_channel.uuid, uuid, sizeof(msg->u.ask_channel.uuid));
 865
 866         if (pathname) {
 867                 strncpy(msg->u.ask_channel.pathname, pathname,
 868                                 sizeof(msg->u.ask_channel.pathname));
 869                 msg->u.ask_channel.pathname[sizeof(msg->u.ask_channel.pathname)-1] = '\0';
 870         }
 871
 872         strncpy(msg->u.ask_channel.name, name, sizeof(msg->u.ask_channel.name));
 873         msg->u.ask_channel.name[sizeof(msg->u.ask_channel.name) - 1] = '\0';
 874
 875         if (root_shm_path) {
 876                 strncpy(msg->u.ask_channel.root_shm_path, root_shm_path,
 877                         sizeof(msg->u.ask_channel.root_shm_path));
 878                 msg->u.ask_channel.root_shm_path[sizeof(msg->u.ask_channel.root_shm_path) - 1] = '\0';
 879         }
 880         if (shm_path) {
 881                 strncpy(msg->u.ask_channel.shm_path, shm_path,
 882                         sizeof(msg->u.ask_channel.shm_path));
 883                 msg->u.ask_channel.shm_path[sizeof(msg->u.ask_channel.shm_path) - 1] = '\0';
 884         }
 885 }
 886
 887 /*
 888  * Init channel communication message structure.
 889  */
 890 void consumer_init_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 891                 enum lttng_consumer_command cmd,
 892                 uint64_t channel_key,
 893                 uint64_t session_id,
 894                 const char *pathname,
 895                 uid_t uid,
 896                 gid_t gid,
 897                 uint64_t relayd_id,
 898                 const char *name,
 899                 unsigned int nb_init_streams,
 900                 enum lttng_event_output output,
 901                 int type,
 902                 uint64_t tracefile_size,
 903                 uint64_t tracefile_count,
 904                 unsigned int monitor,
 905                 unsigned int live_timer_interval,
 906                 bool is_in_live_session)
 907 {
 908         assert(msg);
 909
 910         /* Zeroed structure */
 911         memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
 912
 913         /* Send channel */
 914         msg->cmd_type = cmd;
 915         msg->u.channel.channel_key = channel_key;
 916         msg->u.channel.session_id = session_id;
 917         msg->u.channel.uid = uid;
 918         msg->u.channel.gid = gid;
 919         msg->u.channel.relayd_id = relayd_id;
 920         msg->u.channel.nb_init_streams = nb_init_streams;
 921         msg->u.channel.output = output;
 922         msg->u.channel.type = type;
 923         msg->u.channel.tracefile_size = tracefile_size;
 924         msg->u.channel.tracefile_count = tracefile_count;
 925         msg->u.channel.monitor = monitor;
 926         msg->u.channel.live_timer_interval = live_timer_interval;
 927         msg->u.channel.is_live = is_in_live_session;
 928
 929         strncpy(msg->u.channel.pathname, pathname,
 930                         sizeof(msg->u.channel.pathname));
 931         msg->u.channel.pathname[sizeof(msg->u.channel.pathname) - 1] = '\0';
 932
 933         strncpy(msg->u.channel.name, name, sizeof(msg->u.channel.name));
 934         msg->u.channel.name[sizeof(msg->u.channel.name) - 1] = '\0';
 935 }
 936
 937 /*
 938  * Init stream communication message structure.
 939  */
 940 void consumer_init_stream_comm_msg(struct lttcomm_consumer_msg *msg,
 941                 enum lttng_consumer_command cmd,
 942                 uint64_t channel_key,
 943                 uint64_t stream_key,
 944                 int cpu)
 945 {
 946         assert(msg);
 947
 948         memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
 949
 950         msg->cmd_type = cmd;
 951         msg->u.stream.channel_key = channel_key;
 952         msg->u.stream.stream_key = stream_key;
 953         msg->u.stream.cpu = cpu;
 954 }
 955
 956 void consumer_init_streams_sent_comm_msg(struct lttcomm_consumer_msg *msg,
 957                 enum lttng_consumer_command cmd,
 958                 uint64_t channel_key, uint64_t net_seq_idx)
 959 {
 960         assert(msg);
 961
 962         memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
 963
 964         msg->cmd_type = cmd;
 965         msg->u.sent_streams.channel_key = channel_key;
 966         msg->u.sent_streams.net_seq_idx = net_seq_idx;
 967 }
 968
 969 /*
 970  * Send stream communication structure to the consumer.
 971  */
 972 int consumer_send_stream(struct consumer_socket *sock,
 973                 struct consumer_output *dst, struct lttcomm_consumer_msg *msg,
 974                 int *fds, size_t nb_fd)
 975 {
 976         int ret;
 977
 978         assert(msg);
 979         assert(dst);
 980         assert(sock);
 981         assert(fds);
 982
 983         ret = consumer_send_msg(sock, msg);
 984         if (ret < 0) {
 985                 goto error;
 986         }
 987
 988         ret = consumer_send_fds(sock, fds, nb_fd);
 989         if (ret < 0) {
 990                 goto error;
 991         }
 992
 993 error:
 994         return ret;
 995 }
 996
 997 /*
 998  * Send relayd socket to consumer associated with a session name.
 999  *
1000  * The consumer socket lock must be held by the caller.
1001  *
1002  * On success return positive value. On error, negative value.
1003  */
1004 int consumer_send_relayd_socket(struct consumer_socket *consumer_sock,
1005                 struct lttcomm_relayd_sock *rsock, struct consumer_output *consumer,
1006                 enum lttng_stream_type type, uint64_t session_id,
1007                 char *session_name, char *hostname, int session_live_timer)
1008 {
1009         int ret;
1010         struct lttcomm_consumer_msg msg;
1011
1012         /* Code flow error. Safety net. */
1013         assert(rsock);
1014         assert(consumer);
1015         assert(consumer_sock);
1016
1017         memset(&msg, 0, sizeof(msg));
1018         /* Bail out if consumer is disabled */
1019         if (!consumer->enabled) {
1020                 ret = LTTNG_OK;
1021                 goto error;
1022         }
1023
1024         if (type == LTTNG_STREAM_CONTROL) {
1025                 ret = relayd_create_session(rsock,
1026                                 &msg.u.relayd_sock.relayd_session_id,
1027                                 session_name, hostname, session_live_timer,
1028                                 consumer->snapshot);
1029                 if (ret < 0) {
1030                         /* Close the control socket. */
1031                         (void) relayd_close(rsock);
1032                         goto error;
1033                 }
1034         }
1035
1036         msg.cmd_type = LTTNG_CONSUMER_ADD_RELAYD_SOCKET;
1037         /*
1038          * Assign network consumer output index using the temporary consumer since
1039          * this call should only be made from within a set_consumer_uri() function
1040          * call in the session daemon.
1041          */
1042         msg.u.relayd_sock.net_index = consumer->net_seq_index;
1043         msg.u.relayd_sock.type = type;
1044         msg.u.relayd_sock.session_id = session_id;
1045         memcpy(&msg.u.relayd_sock.sock, rsock, sizeof(msg.u.relayd_sock.sock));
1046
1047         DBG3("Sending relayd sock info to consumer on %d", *consumer_sock->fd_ptr);
1048         ret = consumer_send_msg(consumer_sock, &msg);
1049         if (ret < 0) {
1050                 goto error;
1051         }
1052
1053         DBG3("Sending relayd socket file descriptor to consumer");
1054         ret = consumer_send_fds(consumer_sock, &rsock->sock.fd, 1);
1055         if (ret < 0) {
1056                 goto error;
1057         }
1058
1059         DBG2("Consumer relayd socket sent");
1060
1061 error:
1062         return ret;
1063 }
1064
1065 /*
1066  * Set consumer subdirectory using the session name and a generated datetime if
1067  * needed. This is appended to the current subdirectory.
1068  */
1069 int consumer_set_subdir(struct consumer_output *consumer,
1070                 const char *session_name)
1071 {
1072         int ret = 0;
1073         unsigned int have_default_name = 0;
1074         char datetime[16], tmp_path[PATH_MAX];
1075         time_t rawtime;
1076         struct tm *timeinfo;
1077
1078         assert(consumer);
1079         assert(session_name);
1080
1081         memset(tmp_path, 0, sizeof(tmp_path));
1082
1083         /* Flag if we have a default session. */
1084         if (strncmp(session_name, DEFAULT_SESSION_NAME "-",
1085                                 strlen(DEFAULT_SESSION_NAME) + 1) == 0) {
1086                 have_default_name = 1;
1087         } else {
1088                 /* Get date and time for session path */
1089                 time(&rawtime);
1090                 timeinfo = localtime(&rawtime);
1091                 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1092         }
1093
1094         if (have_default_name) {
1095                 ret = snprintf(tmp_path, sizeof(tmp_path),
1096                                 "%s/%s", consumer->subdir, session_name);
1097         } else {
1098                 ret = snprintf(tmp_path, sizeof(tmp_path),
1099                                 "%s/%s-%s/", consumer->subdir, session_name, datetime);
1100         }
1101         if (ret < 0) {
1102                 PERROR("snprintf session name date");
1103                 goto error;
1104         }
1105
1106         if (lttng_strncpy(consumer->subdir, tmp_path,
1107                         sizeof(consumer->subdir))) {
1108                 ret = -EINVAL;
1109                 goto error;
1110         }
1111         DBG2("Consumer subdir set to %s", consumer->subdir);
1112
1113 error:
1114         return ret;
1115 }
1116
1117 /*
1118  * Ask the consumer if the data is pending for the specific session id.
1119  * Returns 1 if data is pending, 0 otherwise, or < 0 on error.
1120  */
1121 int consumer_is_data_pending(uint64_t session_id,
1122                 struct consumer_output *consumer)
1123 {
1124         int ret;
1125         int32_t ret_code = 0;  /* Default is that the data is NOT pending */
1126         struct consumer_socket *socket;
1127         struct lttng_ht_iter iter;
1128         struct lttcomm_consumer_msg msg;
1129
1130         assert(consumer);
1131
1132         DBG3("Consumer data pending for id %" PRIu64, session_id);
1133
1134         memset(&msg, 0, sizeof(msg));
1135         msg.cmd_type = LTTNG_CONSUMER_DATA_PENDING;
1136         msg.u.data_pending.session_id = session_id;
1137
1138         /* Send command for each consumer */
1139         rcu_read_lock();
1140         cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
1141                         node.node) {
1142                 pthread_mutex_lock(socket->lock);
1143                 ret = consumer_socket_send(socket, &msg, sizeof(msg));
1144                 if (ret < 0) {
1145                         pthread_mutex_unlock(socket->lock);
1146                         goto error_unlock;
1147                 }
1148
1149                 /*
1150                  * No need for a recv reply status because the answer to the command is
1151                  * the reply status message.
1152                  */
1153
1154                 ret = consumer_socket_recv(socket, &ret_code, sizeof(ret_code));
1155                 if (ret < 0) {
1156                         pthread_mutex_unlock(socket->lock);
1157                         goto error_unlock;
1158                 }
1159                 pthread_mutex_unlock(socket->lock);
1160
1161                 if (ret_code == 1) {
1162                         break;
1163                 }
1164         }
1165         rcu_read_unlock();
1166
1167         DBG("Consumer data is %s pending for session id %" PRIu64,
1168                         ret_code == 1 ? "" : "NOT", session_id);
1169         return ret_code;
1170
1171 error_unlock:
1172         rcu_read_unlock();
1173         return -1;
1174 }
1175
1176 /*
1177  * Send a flush command to consumer using the given channel key.
1178  *
1179  * Return 0 on success else a negative value.
1180  */
1181 int consumer_flush_channel(struct consumer_socket *socket, uint64_t key)
1182 {
1183         int ret;
1184         struct lttcomm_consumer_msg msg;
1185
1186         assert(socket);
1187
1188         DBG2("Consumer flush channel key %" PRIu64, key);
1189
1190         memset(&msg, 0, sizeof(msg));
1191         msg.cmd_type = LTTNG_CONSUMER_FLUSH_CHANNEL;
1192         msg.u.flush_channel.key = key;
1193
1194         pthread_mutex_lock(socket->lock);
1195         health_code_update();
1196
1197         ret = consumer_send_msg(socket, &msg);
1198         if (ret < 0) {
1199                 goto end;
1200         }
1201
1202 end:
1203         health_code_update();
1204         pthread_mutex_unlock(socket->lock);
1205         return ret;
1206 }
1207
1208 /*
1209  * Send a clear quiescent command to consumer using the given channel key.
1210  *
1211  * Return 0 on success else a negative value.
1212  */
1213 int consumer_clear_quiescent_channel(struct consumer_socket *socket, uint64_t key)
1214 {
1215         int ret;
1216         struct lttcomm_consumer_msg msg;
1217
1218         assert(socket);
1219
1220         DBG2("Consumer clear quiescent channel key %" PRIu64, key);
1221
1222         memset(&msg, 0, sizeof(msg));
1223         msg.cmd_type = LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL;
1224         msg.u.clear_quiescent_channel.key = key;
1225
1226         pthread_mutex_lock(socket->lock);
1227         health_code_update();
1228
1229         ret = consumer_send_msg(socket, &msg);
1230         if (ret < 0) {
1231                 goto end;
1232         }
1233
1234 end:
1235         health_code_update();
1236         pthread_mutex_unlock(socket->lock);
1237         return ret;
1238 }
1239
1240 /*
1241  * Send a close metadata command to consumer using the given channel key.
1242  * Called with registry lock held.
1243  *
1244  * Return 0 on success else a negative value.
1245  */
1246 int consumer_close_metadata(struct consumer_socket *socket,
1247                 uint64_t metadata_key)
1248 {
1249         int ret;
1250         struct lttcomm_consumer_msg msg;
1251
1252         assert(socket);
1253
1254         DBG2("Consumer close metadata channel key %" PRIu64, metadata_key);
1255
1256         memset(&msg, 0, sizeof(msg));
1257         msg.cmd_type = LTTNG_CONSUMER_CLOSE_METADATA;
1258         msg.u.close_metadata.key = metadata_key;
1259
1260         pthread_mutex_lock(socket->lock);
1261         health_code_update();
1262
1263         ret = consumer_send_msg(socket, &msg);
1264         if (ret < 0) {
1265                 goto end;
1266         }
1267
1268 end:
1269         health_code_update();
1270         pthread_mutex_unlock(socket->lock);
1271         return ret;
1272 }
1273
1274 /*
1275  * Send a setup metdata command to consumer using the given channel key.
1276  *
1277  * Return 0 on success else a negative value.
1278  */
1279 int consumer_setup_metadata(struct consumer_socket *socket,
1280                 uint64_t metadata_key)
1281 {
1282         int ret;
1283         struct lttcomm_consumer_msg msg;
1284
1285         assert(socket);
1286
1287         DBG2("Consumer setup metadata channel key %" PRIu64, metadata_key);
1288
1289         memset(&msg, 0, sizeof(msg));
1290         msg.cmd_type = LTTNG_CONSUMER_SETUP_METADATA;
1291         msg.u.setup_metadata.key = metadata_key;
1292
1293         pthread_mutex_lock(socket->lock);
1294         health_code_update();
1295
1296         ret = consumer_send_msg(socket, &msg);
1297         if (ret < 0) {
1298                 goto end;
1299         }
1300
1301 end:
1302         health_code_update();
1303         pthread_mutex_unlock(socket->lock);
1304         return ret;
1305 }
1306
1307 /*
1308  * Send metadata string to consumer.
1309  * RCU read-side lock must be held to guarantee existence of socket.
1310  *
1311  * Return 0 on success else a negative value.
1312  */
1313 int consumer_push_metadata(struct consumer_socket *socket,
1314                 uint64_t metadata_key, char *metadata_str, size_t len,
1315                 size_t target_offset, uint64_t version)
1316 {
1317         int ret;
1318         struct lttcomm_consumer_msg msg;
1319
1320         assert(socket);
1321
1322         DBG2("Consumer push metadata to consumer socket %d", *socket->fd_ptr);
1323
1324         pthread_mutex_lock(socket->lock);
1325
1326         memset(&msg, 0, sizeof(msg));
1327         msg.cmd_type = LTTNG_CONSUMER_PUSH_METADATA;
1328         msg.u.push_metadata.key = metadata_key;
1329         msg.u.push_metadata.target_offset = target_offset;
1330         msg.u.push_metadata.len = len;
1331         msg.u.push_metadata.version = version;
1332
1333         health_code_update();
1334         ret = consumer_send_msg(socket, &msg);
1335         if (ret < 0 || len == 0) {
1336                 goto end;
1337         }
1338
1339         DBG3("Consumer pushing metadata on sock %d of len %zu", *socket->fd_ptr,
1340                         len);
1341
1342         ret = consumer_socket_send(socket, metadata_str, len);
1343         if (ret < 0) {
1344                 goto end;
1345         }
1346
1347         health_code_update();
1348         ret = consumer_recv_status_reply(socket);
1349         if (ret < 0) {
1350                 goto end;
1351         }
1352
1353 end:
1354         pthread_mutex_unlock(socket->lock);
1355         health_code_update();
1356         return ret;
1357 }
1358
1359 /*
1360  * Ask the consumer to snapshot a specific channel using the key.
1361  *
1362  * Return 0 on success or else a negative error.
1363  */
1364 int consumer_snapshot_channel(struct consumer_socket *socket, uint64_t key,
1365                 struct snapshot_output *output, int metadata, uid_t uid, gid_t gid,
1366                 const char *session_path, int wait, uint64_t nb_packets_per_stream)
1367 {
1368         int ret;
1369         struct lttcomm_consumer_msg msg;
1370
1371         assert(socket);
1372         assert(output);
1373         assert(output->consumer);
1374
1375         DBG("Consumer snapshot channel key %" PRIu64, key);
1376
1377         memset(&msg, 0, sizeof(msg));
1378         msg.cmd_type = LTTNG_CONSUMER_SNAPSHOT_CHANNEL;
1379         msg.u.snapshot_channel.key = key;
1380         msg.u.snapshot_channel.nb_packets_per_stream = nb_packets_per_stream;
1381         msg.u.snapshot_channel.metadata = metadata;
1382
1383         if (output->consumer->type == CONSUMER_DST_NET) {
1384                 msg.u.snapshot_channel.relayd_id = output->consumer->net_seq_index;
1385                 msg.u.snapshot_channel.use_relayd = 1;
1386                 ret = snprintf(msg.u.snapshot_channel.pathname,
1387                                 sizeof(msg.u.snapshot_channel.pathname),
1388                                 "%s/%s-%s-%" PRIu64 "%s", output->consumer->subdir,
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         } else {
1396                 ret = snprintf(msg.u.snapshot_channel.pathname,
1397                                 sizeof(msg.u.snapshot_channel.pathname),
1398                                 "%s/%s-%s-%" PRIu64 "%s", output->consumer->dst.trace_path,
1399                                 output->name, output->datetime, output->nb_snapshot,
1400                                 session_path);
1401                 if (ret < 0) {
1402                         ret = -LTTNG_ERR_NOMEM;
1403                         goto error;
1404                 }
1405                 msg.u.snapshot_channel.relayd_id = (uint64_t) -1ULL;
1406
1407                 /* Create directory. Ignore if exist. */
1408                 ret = run_as_mkdir_recursive(msg.u.snapshot_channel.pathname,
1409                                 S_IRWXU | S_IRWXG, uid, gid);
1410                 if (ret < 0) {
1411                         if (errno != EEXIST) {
1412                                 ERR("Trace directory creation error");
1413                                 goto error;
1414                         }
1415                 }
1416         }
1417
1418         health_code_update();
1419         pthread_mutex_lock(socket->lock);
1420         ret = consumer_send_msg(socket, &msg);
1421         pthread_mutex_unlock(socket->lock);
1422         if (ret < 0) {
1423                 goto error;
1424         }
1425
1426 error:
1427         health_code_update();
1428         return ret;
1429 }
1430
1431 /*
1432  * Ask the consumer the number of discarded events for a channel.
1433  */
1434 int consumer_get_discarded_events(uint64_t session_id, uint64_t channel_key,
1435                 struct consumer_output *consumer, uint64_t *discarded)
1436 {
1437         int ret;
1438         struct consumer_socket *socket;
1439         struct lttng_ht_iter iter;
1440         struct lttcomm_consumer_msg msg;
1441
1442         assert(consumer);
1443
1444         DBG3("Consumer discarded events id %" PRIu64, session_id);
1445
1446         memset(&msg, 0, sizeof(msg));
1447         msg.cmd_type = LTTNG_CONSUMER_DISCARDED_EVENTS;
1448         msg.u.discarded_events.session_id = session_id;
1449         msg.u.discarded_events.channel_key = channel_key;
1450
1451         *discarded = 0;
1452
1453         /* Send command for each consumer */
1454         rcu_read_lock();
1455         cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
1456                         node.node) {
1457                 uint64_t consumer_discarded = 0;
1458                 pthread_mutex_lock(socket->lock);
1459                 ret = consumer_socket_send(socket, &msg, sizeof(msg));
1460                 if (ret < 0) {
1461                         pthread_mutex_unlock(socket->lock);
1462                         goto end;
1463                 }
1464
1465                 /*
1466                  * No need for a recv reply status because the answer to the
1467                  * command is the reply status message.
1468                  */
1469                 ret = consumer_socket_recv(socket, &consumer_discarded,
1470                                 sizeof(consumer_discarded));
1471                 if (ret < 0) {
1472                         ERR("get discarded events");
1473                         pthread_mutex_unlock(socket->lock);
1474                         goto end;
1475                 }
1476                 pthread_mutex_unlock(socket->lock);
1477                 *discarded += consumer_discarded;
1478         }
1479         ret = 0;
1480         DBG("Consumer discarded %" PRIu64 " events in session id %" PRIu64,
1481                         *discarded, session_id);
1482
1483 end:
1484         rcu_read_unlock();
1485         return ret;
1486 }
1487
1488 /*
1489  * Ask the consumer the number of lost packets for a channel.
1490  */
1491 int consumer_get_lost_packets(uint64_t session_id, uint64_t channel_key,
1492                 struct consumer_output *consumer, uint64_t *lost)
1493 {
1494         int ret;
1495         struct consumer_socket *socket;
1496         struct lttng_ht_iter iter;
1497         struct lttcomm_consumer_msg msg;
1498
1499         assert(consumer);
1500
1501         DBG3("Consumer lost packets id %" PRIu64, session_id);
1502
1503         memset(&msg, 0, sizeof(msg));
1504         msg.cmd_type = LTTNG_CONSUMER_LOST_PACKETS;
1505         msg.u.lost_packets.session_id = session_id;
1506         msg.u.lost_packets.channel_key = channel_key;
1507
1508         *lost = 0;
1509
1510         /* Send command for each consumer */
1511         rcu_read_lock();
1512         cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
1513                         node.node) {
1514                 uint64_t consumer_lost = 0;
1515                 pthread_mutex_lock(socket->lock);
1516                 ret = consumer_socket_send(socket, &msg, sizeof(msg));
1517                 if (ret < 0) {
1518                         pthread_mutex_unlock(socket->lock);
1519                         goto end;
1520                 }
1521
1522                 /*
1523                  * No need for a recv reply status because the answer to the
1524                  * command is the reply status message.
1525                  */
1526                 ret = consumer_socket_recv(socket, &consumer_lost,
1527                                 sizeof(consumer_lost));
1528                 if (ret < 0) {
1529                         ERR("get lost packets");
1530                         pthread_mutex_unlock(socket->lock);
1531                         goto end;
1532                 }
1533                 pthread_mutex_unlock(socket->lock);
1534                 *lost += consumer_lost;
1535         }
1536         ret = 0;
1537         DBG("Consumer lost %" PRIu64 " packets in session id %" PRIu64,
1538                         *lost, session_id);
1539
1540 end:
1541         rcu_read_unlock();
1542         return ret;
1543 }