src/bin/lttng-sessiond/cmd.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <assert.h>
  20 #include <urcu/list.h>
  21 #include <urcu/uatomic.h>
  22
  23 #include <common/defaults.h>
  24 #include <common/common.h>
  25 #include <common/sessiond-comm/sessiond-comm.h>
  26 #include <common/relayd/relayd.h>
  27
  28 #include "channel.h"
  29 #include "consumer.h"
  30 #include "event.h"
  31 #include "kernel.h"
  32 #include "kernel-consumer.h"
  33 #include "lttng-sessiond.h"
  34 #include "utils.h"
  35
  36 #include "cmd.h"
  37
  38 /*
  39  * Used to keep a unique index for each relayd socket created where this value
  40  * is associated with streams on the consumer so it can match the right relayd
  41  * to send to.
  42  *
  43  * This value should be incremented atomically for safety purposes and future
  44  * possible concurrent access.
  45  */
  46 static unsigned int relayd_net_seq_idx;
  47
  48 /*
  49  * Create a session path used by list_lttng_sessions for the case that the
  50  * session consumer is on the network.
  51  */
  52 static int build_network_session_path(char *dst, size_t size,
  53                 struct ltt_session *session)
  54 {
  55         int ret, kdata_port, udata_port;
  56         struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
  57         char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
  58
  59         assert(session);
  60         assert(dst);
  61
  62         memset(tmp_urls, 0, sizeof(tmp_urls));
  63         memset(tmp_uurl, 0, sizeof(tmp_uurl));
  64
  65         kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
  66
  67         if (session->kernel_session && session->kernel_session->consumer) {
  68                 kuri = &session->kernel_session->consumer->dst.net.control;
  69                 kdata_port = session->kernel_session->consumer->dst.net.data.port;
  70         }
  71
  72         if (session->ust_session && session->ust_session->consumer) {
  73                 uuri = &session->ust_session->consumer->dst.net.control;
  74                 udata_port = session->ust_session->consumer->dst.net.data.port;
  75         }
  76
  77         if (uuri == NULL && kuri == NULL) {
  78                 uri = &session->consumer->dst.net.control;
  79                 kdata_port = session->consumer->dst.net.data.port;
  80         } else if (kuri && uuri) {
  81                 ret = uri_compare(kuri, uuri);
  82                 if (ret) {
  83                         /* Not Equal */
  84                         uri = kuri;
  85                         /* Build uuri URL string */
  86                         ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
  87                         if (ret < 0) {
  88                                 goto error;
  89                         }
  90                 } else {
  91                         uri = kuri;
  92                 }
  93         } else if (kuri && uuri == NULL) {
  94                 uri = kuri;
  95         } else if (uuri && kuri == NULL) {
  96                 uri = uuri;
  97         }
  98
  99         ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
 100         if (ret < 0) {
 101                 goto error;
 102         }
 103
 104         if (strlen(tmp_uurl) > 0) {
 105                 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
 106                                 tmp_urls, kdata_port, tmp_uurl, udata_port);
 107         } else {
 108                 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, kdata_port);
 109         }
 110
 111 error:
 112         return ret;
 113 }
 114
 115 /*
 116  * Fill lttng_channel array of all channels.
 117  */
 118 static void list_lttng_channels(int domain, struct ltt_session *session,
 119                 struct lttng_channel *channels)
 120 {
 121         int i = 0;
 122         struct ltt_kernel_channel *kchan;
 123
 124         DBG("Listing channels for session %s", session->name);
 125
 126         switch (domain) {
 127         case LTTNG_DOMAIN_KERNEL:
 128                 /* Kernel channels */
 129                 if (session->kernel_session != NULL) {
 130                         cds_list_for_each_entry(kchan,
 131                                         &session->kernel_session->channel_list.head, list) {
 132                                 /* Copy lttng_channel struct to array */
 133                                 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
 134                                 channels[i].enabled = kchan->enabled;
 135                                 i++;
 136                         }
 137                 }
 138                 break;
 139         case LTTNG_DOMAIN_UST:
 140         {
 141                 struct lttng_ht_iter iter;
 142                 struct ltt_ust_channel *uchan;
 143
 144                 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
 145                                 &iter.iter, uchan, node.node) {
 146                         strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
 147                         channels[i].attr.overwrite = uchan->attr.overwrite;
 148                         channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
 149                         channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
 150                         channels[i].attr.switch_timer_interval =
 151                                 uchan->attr.switch_timer_interval;
 152                         channels[i].attr.read_timer_interval =
 153                                 uchan->attr.read_timer_interval;
 154                         channels[i].enabled = uchan->enabled;
 155                         switch (uchan->attr.output) {
 156                         case LTTNG_UST_MMAP:
 157                         default:
 158                                 channels[i].attr.output = LTTNG_EVENT_MMAP;
 159                                 break;
 160                         }
 161                         i++;
 162                 }
 163                 break;
 164         }
 165         default:
 166                 break;
 167         }
 168 }
 169
 170 /*
 171  * Create a list of ust global domain events.
 172  */
 173 static int list_lttng_ust_global_events(char *channel_name,
 174                 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
 175 {
 176         int i = 0, ret = 0;
 177         unsigned int nb_event = 0;
 178         struct lttng_ht_iter iter;
 179         struct lttng_ht_node_str *node;
 180         struct ltt_ust_channel *uchan;
 181         struct ltt_ust_event *uevent;
 182         struct lttng_event *tmp;
 183
 184         DBG("Listing UST global events for channel %s", channel_name);
 185
 186         rcu_read_lock();
 187
 188         lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
 189         node = lttng_ht_iter_get_node_str(&iter);
 190         if (node == NULL) {
 191                 ret = -LTTCOMM_UST_CHAN_NOT_FOUND;
 192                 goto error;
 193         }
 194
 195         uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
 196
 197         nb_event += lttng_ht_get_count(uchan->events);
 198
 199         if (nb_event == 0) {
 200                 ret = nb_event;
 201                 goto error;
 202         }
 203
 204         DBG3("Listing UST global %d events", nb_event);
 205
 206         tmp = zmalloc(nb_event * sizeof(struct lttng_event));
 207         if (tmp == NULL) {
 208                 ret = -LTTCOMM_FATAL;
 209                 goto error;
 210         }
 211
 212         cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
 213                 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
 214                 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 215                 tmp[i].enabled = uevent->enabled;
 216
 217                 switch (uevent->attr.instrumentation) {
 218                 case LTTNG_UST_TRACEPOINT:
 219                         tmp[i].type = LTTNG_EVENT_TRACEPOINT;
 220                         break;
 221                 case LTTNG_UST_PROBE:
 222                         tmp[i].type = LTTNG_EVENT_PROBE;
 223                         break;
 224                 case LTTNG_UST_FUNCTION:
 225                         tmp[i].type = LTTNG_EVENT_FUNCTION;
 226                         break;
 227                 }
 228
 229                 tmp[i].loglevel = uevent->attr.loglevel;
 230                 switch (uevent->attr.loglevel_type) {
 231                 case LTTNG_UST_LOGLEVEL_ALL:
 232                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 233                         break;
 234                 case LTTNG_UST_LOGLEVEL_RANGE:
 235                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 236                         break;
 237                 case LTTNG_UST_LOGLEVEL_SINGLE:
 238                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 239                         break;
 240                 }
 241                 if (uevent->filter) {
 242                         tmp[i].filter = 1;
 243                 }
 244                 i++;
 245         }
 246
 247         ret = nb_event;
 248         *events = tmp;
 249
 250 error:
 251         rcu_read_unlock();
 252         return ret;
 253 }
 254
 255 /*
 256  * Fill lttng_event array of all kernel events in the channel.
 257  */
 258 static int list_lttng_kernel_events(char *channel_name,
 259                 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
 260 {
 261         int i = 0, ret;
 262         unsigned int nb_event;
 263         struct ltt_kernel_event *event;
 264         struct ltt_kernel_channel *kchan;
 265
 266         kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
 267         if (kchan == NULL) {
 268                 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
 269                 goto error;
 270         }
 271
 272         nb_event = kchan->event_count;
 273
 274         DBG("Listing events for channel %s", kchan->channel->name);
 275
 276         if (nb_event == 0) {
 277                 ret = nb_event;
 278                 goto error;
 279         }
 280
 281         *events = zmalloc(nb_event * sizeof(struct lttng_event));
 282         if (*events == NULL) {
 283                 ret = LTTCOMM_FATAL;
 284                 goto error;
 285         }
 286
 287         /* Kernel channels */
 288         cds_list_for_each_entry(event, &kchan->events_list.head , list) {
 289                 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
 290                 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 291                 (*events)[i].enabled = event->enabled;
 292
 293                 switch (event->event->instrumentation) {
 294                 case LTTNG_KERNEL_TRACEPOINT:
 295                         (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
 296                         break;
 297                 case LTTNG_KERNEL_KPROBE:
 298                 case LTTNG_KERNEL_KRETPROBE:
 299                         (*events)[i].type = LTTNG_EVENT_PROBE;
 300                         memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
 301                                         sizeof(struct lttng_kernel_kprobe));
 302                         break;
 303                 case LTTNG_KERNEL_FUNCTION:
 304                         (*events)[i].type = LTTNG_EVENT_FUNCTION;
 305                         memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
 306                                         sizeof(struct lttng_kernel_function));
 307                         break;
 308                 case LTTNG_KERNEL_NOOP:
 309                         (*events)[i].type = LTTNG_EVENT_NOOP;
 310                         break;
 311                 case LTTNG_KERNEL_SYSCALL:
 312                         (*events)[i].type = LTTNG_EVENT_SYSCALL;
 313                         break;
 314                 case LTTNG_KERNEL_ALL:
 315                         assert(0);
 316                         break;
 317                 }
 318                 i++;
 319         }
 320
 321         return nb_event;
 322
 323 error:
 324         return ret;
 325 }
 326
 327 /*
 328  * Add URI so the consumer output object. Set the correct path depending on the
 329  * domain adding the default trace directory.
 330  */
 331 static int add_uri_to_consumer(struct consumer_output *consumer,
 332                 struct lttng_uri *uri, int domain, const char *session_name)
 333 {
 334         int ret = LTTCOMM_OK;
 335         const char *default_trace_dir;
 336
 337         assert(uri);
 338
 339         if (consumer == NULL) {
 340                 DBG("No consumer detected. Don't add URI. Stopping.");
 341                 ret = LTTCOMM_NO_CONSUMER;
 342                 goto error;
 343         }
 344
 345         switch (domain) {
 346         case LTTNG_DOMAIN_KERNEL:
 347                 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
 348                 break;
 349         case LTTNG_DOMAIN_UST:
 350                 default_trace_dir = DEFAULT_UST_TRACE_DIR;
 351                 break;
 352         default:
 353                 /*
 354                  * This case is possible is we try to add the URI to the global tracing
 355                  * session consumer object which in this case there is no subdir.
 356                  */
 357                 default_trace_dir = "";
 358         }
 359
 360         switch (uri->dtype) {
 361         case LTTNG_DST_IPV4:
 362         case LTTNG_DST_IPV6:
 363                 DBG2("Setting network URI to consumer");
 364
 365                 /* Set URI into consumer output object */
 366                 ret = consumer_set_network_uri(consumer, uri);
 367                 if (ret < 0) {
 368                         ret = LTTCOMM_FATAL;
 369                         goto error;
 370                 } else if (ret == 1) {
 371                         /*
 372                          * URI was the same in the consumer so we do not append the subdir
 373                          * again so to not duplicate output dir.
 374                          */
 375                         goto error;
 376                 }
 377
 378                 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
 379                         ret = consumer_set_subdir(consumer, session_name);
 380                         if (ret < 0) {
 381                                 ret = LTTCOMM_FATAL;
 382                                 goto error;
 383                         }
 384                 }
 385
 386                 if (uri->stype == LTTNG_STREAM_CONTROL) {
 387                         /* On a new subdir, reappend the default trace dir. */
 388                         strncat(consumer->subdir, default_trace_dir, sizeof(consumer->subdir));
 389                         DBG3("Append domain trace name to subdir %s", consumer->subdir);
 390                 }
 391
 392                 break;
 393         case LTTNG_DST_PATH:
 394                 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
 395                 memset(consumer->dst.trace_path, 0,
 396                                 sizeof(consumer->dst.trace_path));
 397                 strncpy(consumer->dst.trace_path, uri->dst.path,
 398                                 sizeof(consumer->dst.trace_path));
 399                 /* Append default trace dir */
 400                 strncat(consumer->dst.trace_path, default_trace_dir,
 401                                 sizeof(consumer->dst.trace_path));
 402                 /* Flag consumer as local. */
 403                 consumer->type = CONSUMER_DST_LOCAL;
 404                 break;
 405         }
 406
 407 error:
 408         return ret;
 409 }
 410
 411 /*
 412  * Init tracing by creating trace directory and sending fds kernel consumer.
 413  */
 414 static int init_kernel_tracing(struct ltt_kernel_session *session)
 415 {
 416         int ret = 0;
 417         struct lttng_ht_iter iter;
 418         struct consumer_socket *socket;
 419
 420         assert(session);
 421
 422         if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
 423                 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
 424                                 socket, node.node) {
 425                         /* Code flow error */
 426                         assert(socket->fd >= 0);
 427
 428                         pthread_mutex_lock(socket->lock);
 429                         ret = kernel_consumer_send_session(socket->fd, session);
 430                         pthread_mutex_unlock(socket->lock);
 431                         if (ret < 0) {
 432                                 ret = LTTCOMM_KERN_CONSUMER_FAIL;
 433                                 goto error;
 434                         }
 435                 }
 436         }
 437
 438 error:
 439         return ret;
 440 }
 441
 442 /*
 443  * Create a socket to the relayd using the URI.
 444  *
 445  * On success, the relayd_sock pointer is set to the created socket.
 446  * Else, it's stays untouched and a lttcomm error code is returned.
 447  */
 448 static int create_connect_relayd(struct consumer_output *output,
 449                 const char *session_name, struct lttng_uri *uri,
 450                 struct lttcomm_sock **relayd_sock)
 451 {
 452         int ret;
 453         struct lttcomm_sock *sock;
 454
 455         /* Create socket object from URI */
 456         sock = lttcomm_alloc_sock_from_uri(uri);
 457         if (sock == NULL) {
 458                 ret = LTTCOMM_FATAL;
 459                 goto error;
 460         }
 461
 462         ret = lttcomm_create_sock(sock);
 463         if (ret < 0) {
 464                 ret = LTTCOMM_FATAL;
 465                 goto error;
 466         }
 467
 468         /* Connect to relayd so we can proceed with a session creation. */
 469         ret = relayd_connect(sock);
 470         if (ret < 0) {
 471                 ERR("Unable to reach lttng-relayd");
 472                 ret = LTTCOMM_RELAYD_SESSION_FAIL;
 473                 goto free_sock;
 474         }
 475
 476         /* Create socket for control stream. */
 477         if (uri->stype == LTTNG_STREAM_CONTROL) {
 478                 DBG3("Creating relayd stream socket from URI");
 479
 480                 /* Check relayd version */
 481                 ret = relayd_version_check(sock, RELAYD_VERSION_COMM_MAJOR,
 482                                 RELAYD_VERSION_COMM_MINOR);
 483                 if (ret < 0) {
 484                         ret = LTTCOMM_RELAYD_VERSION_FAIL;
 485                         goto close_sock;
 486                 }
 487         } else if (uri->stype == LTTNG_STREAM_DATA) {
 488                 DBG3("Creating relayd data socket from URI");
 489         } else {
 490                 /* Command is not valid */
 491                 ERR("Relayd invalid stream type: %d", uri->stype);
 492                 ret = LTTCOMM_INVALID;
 493                 goto close_sock;
 494         }
 495
 496         *relayd_sock = sock;
 497
 498         return LTTCOMM_OK;
 499
 500 close_sock:
 501         if (sock) {
 502                 (void) relayd_close(sock);
 503         }
 504 free_sock:
 505         if (sock) {
 506                 lttcomm_destroy_sock(sock);
 507         }
 508 error:
 509         return ret;
 510 }
 511
 512 /*
 513  * Connect to the relayd using URI and send the socket to the right consumer.
 514  */
 515 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
 516                 struct lttng_uri *relayd_uri, struct consumer_output *consumer,
 517                 int consumer_fd)
 518 {
 519         int ret;
 520         struct lttcomm_sock *sock = NULL;
 521
 522         /* Set the network sequence index if not set. */
 523         if (consumer->net_seq_index == -1) {
 524                 /*
 525                  * Increment net_seq_idx because we are about to transfer the
 526                  * new relayd socket to the consumer.
 527                  */
 528                 uatomic_inc(&relayd_net_seq_idx);
 529                 /* Assign unique key so the consumer can match streams */
 530                 uatomic_set(&consumer->net_seq_index,
 531                                 uatomic_read(&relayd_net_seq_idx));
 532         }
 533
 534         /* Connect to relayd and make version check if uri is the control. */
 535         ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
 536         if (ret != LTTCOMM_OK) {
 537                 goto close_sock;
 538         }
 539
 540         /* If the control socket is connected, network session is ready */
 541         if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
 542                 session->net_handle = 1;
 543         }
 544
 545         /* Send relayd socket to consumer. */
 546         ret = consumer_send_relayd_socket(consumer_fd, sock,
 547                         consumer, relayd_uri->stype);
 548         if (ret < 0) {
 549                 ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
 550                 goto close_sock;
 551         }
 552
 553         ret = LTTCOMM_OK;
 554
 555         /*
 556          * Close socket which was dup on the consumer side. The session daemon does
 557          * NOT keep track of the relayd socket(s) once transfer to the consumer.
 558          */
 559
 560 close_sock:
 561         if (sock) {
 562                 (void) relayd_close(sock);
 563                 lttcomm_destroy_sock(sock);
 564         }
 565
 566         return ret;
 567 }
 568
 569 /*
 570  * Send both relayd sockets to a specific consumer and domain.  This is a
 571  * helper function to facilitate sending the information to the consumer for a
 572  * session.
 573  */
 574 static int send_consumer_relayd_sockets(int domain,
 575                 struct ltt_session *session, struct consumer_output *consumer, int fd)
 576 {
 577         int ret;
 578
 579         assert(session);
 580         assert(consumer);
 581
 582         /* Don't resend the sockets to the consumer. */
 583         if (consumer->dst.net.relayd_socks_sent) {
 584                 ret = LTTCOMM_OK;
 585                 goto error;
 586         }
 587
 588         /* Sending control relayd socket. */
 589         ret = send_consumer_relayd_socket(domain, session,
 590                         &consumer->dst.net.control, consumer, fd);
 591         if (ret != LTTCOMM_OK) {
 592                 goto error;
 593         }
 594
 595         /* Sending data relayd socket. */
 596         ret = send_consumer_relayd_socket(domain, session,
 597                         &consumer->dst.net.data, consumer, fd);
 598         if (ret != LTTCOMM_OK) {
 599                 goto error;
 600         }
 601
 602         /* Flag that all relayd sockets were sent to the consumer. */
 603         consumer->dst.net.relayd_socks_sent = 1;
 604
 605 error:
 606         return ret;
 607 }
 608
 609 /*
 610  * Setup relayd connections for a tracing session. First creates the socket to
 611  * the relayd and send them to the right domain consumer. Consumer type MUST be
 612  * network.
 613  */
 614 static int setup_relayd(struct ltt_session *session)
 615 {
 616         int ret = LTTCOMM_OK;
 617         struct ltt_ust_session *usess;
 618         struct ltt_kernel_session *ksess;
 619         struct consumer_socket *socket;
 620         struct lttng_ht_iter iter;
 621
 622         assert(session);
 623
 624         usess = session->ust_session;
 625         ksess = session->kernel_session;
 626
 627         DBG2("Setting relayd for session %s", session->name);
 628
 629         if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 630                         && usess->consumer->enabled) {
 631                 /* For each consumer socket, send relayd sockets */
 632                 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
 633                                 socket, node.node) {
 634                         /* Code flow error */
 635                         assert(socket->fd >= 0);
 636
 637                         pthread_mutex_lock(socket->lock);
 638                         send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
 639                                         usess->consumer, socket->fd);
 640                         pthread_mutex_unlock(socket->lock);
 641                         if (ret != LTTCOMM_OK) {
 642                                 goto error;
 643                         }
 644                 }
 645         }
 646
 647         if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
 648                         && ksess->consumer->enabled) {
 649                 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
 650                                 socket, node.node) {
 651                         /* Code flow error */
 652                         assert(socket->fd >= 0);
 653
 654                         pthread_mutex_lock(socket->lock);
 655                         send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
 656                                         ksess->consumer, socket->fd);
 657                         pthread_mutex_unlock(socket->lock);
 658                         if (ret != LTTCOMM_OK) {
 659                                 goto error;
 660                         }
 661                 }
 662         }
 663
 664 error:
 665         return ret;
 666 }
 667
 668 /*
 669  * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
 670  */
 671 int cmd_disable_channel(struct ltt_session *session, int domain,
 672                 char *channel_name)
 673 {
 674         int ret;
 675         struct ltt_ust_session *usess;
 676
 677         usess = session->ust_session;
 678
 679         switch (domain) {
 680         case LTTNG_DOMAIN_KERNEL:
 681         {
 682                 ret = channel_kernel_disable(session->kernel_session,
 683                                 channel_name);
 684                 if (ret != LTTCOMM_OK) {
 685                         goto error;
 686                 }
 687
 688                 kernel_wait_quiescent(kernel_tracer_fd);
 689                 break;
 690         }
 691         case LTTNG_DOMAIN_UST:
 692         {
 693                 struct ltt_ust_channel *uchan;
 694                 struct lttng_ht *chan_ht;
 695
 696                 chan_ht = usess->domain_global.channels;
 697
 698                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 699                 if (uchan == NULL) {
 700                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
 701                         goto error;
 702                 }
 703
 704                 ret = channel_ust_disable(usess, domain, uchan);
 705                 if (ret != LTTCOMM_OK) {
 706                         goto error;
 707                 }
 708                 break;
 709         }
 710 #if 0
 711         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 712         case LTTNG_DOMAIN_UST_EXEC_NAME:
 713         case LTTNG_DOMAIN_UST_PID:
 714 #endif
 715         default:
 716                 ret = LTTCOMM_UNKNOWN_DOMAIN;
 717                 goto error;
 718         }
 719
 720         ret = LTTCOMM_OK;
 721
 722 error:
 723         return ret;
 724 }
 725
 726 /*
 727  * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
 728  *
 729  * The wpipe arguments is used as a notifier for the kernel thread.
 730  */
 731 int cmd_enable_channel(struct ltt_session *session,
 732                 int domain, struct lttng_channel *attr, int wpipe)
 733 {
 734         int ret;
 735         struct ltt_ust_session *usess = session->ust_session;
 736         struct lttng_ht *chan_ht;
 737
 738         assert(session);
 739         assert(attr);
 740
 741         DBG("Enabling channel %s for session %s", attr->name, session->name);
 742
 743         switch (domain) {
 744         case LTTNG_DOMAIN_KERNEL:
 745         {
 746                 struct ltt_kernel_channel *kchan;
 747
 748                 /* Mandatory for a kernel channel. */
 749                 assert(wpipe > 0);
 750
 751                 kchan = trace_kernel_get_channel_by_name(attr->name,
 752                                 session->kernel_session);
 753                 if (kchan == NULL) {
 754                         ret = channel_kernel_create(session->kernel_session, attr, wpipe);
 755                 } else {
 756                         ret = channel_kernel_enable(session->kernel_session, kchan);
 757                 }
 758
 759                 if (ret != LTTCOMM_OK) {
 760                         goto error;
 761                 }
 762
 763                 kernel_wait_quiescent(kernel_tracer_fd);
 764                 break;
 765         }
 766         case LTTNG_DOMAIN_UST:
 767         {
 768                 struct ltt_ust_channel *uchan;
 769
 770                 chan_ht = usess->domain_global.channels;
 771
 772                 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
 773                 if (uchan == NULL) {
 774                         ret = channel_ust_create(usess, domain, attr);
 775                 } else {
 776                         ret = channel_ust_enable(usess, domain, uchan);
 777                 }
 778                 break;
 779         }
 780 #if 0
 781         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 782         case LTTNG_DOMAIN_UST_EXEC_NAME:
 783         case LTTNG_DOMAIN_UST_PID:
 784 #endif
 785         default:
 786                 ret = LTTCOMM_UNKNOWN_DOMAIN;
 787                 goto error;
 788         }
 789
 790 error:
 791         return ret;
 792 }
 793
 794
 795 /*
 796  * Command LTTNG_DISABLE_EVENT processed by the client thread.
 797  */
 798 int cmd_disable_event(struct ltt_session *session, int domain,
 799                 char *channel_name, char *event_name)
 800 {
 801         int ret;
 802
 803         switch (domain) {
 804         case LTTNG_DOMAIN_KERNEL:
 805         {
 806                 struct ltt_kernel_channel *kchan;
 807                 struct ltt_kernel_session *ksess;
 808
 809                 ksess = session->kernel_session;
 810
 811                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 812                 if (kchan == NULL) {
 813                         ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
 814                         goto error;
 815                 }
 816
 817                 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
 818                 if (ret != LTTCOMM_OK) {
 819                         goto error;
 820                 }
 821
 822                 kernel_wait_quiescent(kernel_tracer_fd);
 823                 break;
 824         }
 825         case LTTNG_DOMAIN_UST:
 826         {
 827                 struct ltt_ust_channel *uchan;
 828                 struct ltt_ust_session *usess;
 829
 830                 usess = session->ust_session;
 831
 832                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 833                                 channel_name);
 834                 if (uchan == NULL) {
 835                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
 836                         goto error;
 837                 }
 838
 839                 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
 840                 if (ret != LTTCOMM_OK) {
 841                         goto error;
 842                 }
 843
 844                 DBG3("Disable UST event %s in channel %s completed", event_name,
 845                                 channel_name);
 846                 break;
 847         }
 848 #if 0
 849         case LTTNG_DOMAIN_UST_EXEC_NAME:
 850         case LTTNG_DOMAIN_UST_PID:
 851         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 852 #endif
 853         default:
 854                 ret = LTTCOMM_UND;
 855                 goto error;
 856         }
 857
 858         ret = LTTCOMM_OK;
 859
 860 error:
 861         return ret;
 862 }
 863
 864 /*
 865  * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
 866  */
 867 int cmd_disable_event_all(struct ltt_session *session, int domain,
 868                 char *channel_name)
 869 {
 870         int ret;
 871
 872         switch (domain) {
 873         case LTTNG_DOMAIN_KERNEL:
 874         {
 875                 struct ltt_kernel_session *ksess;
 876                 struct ltt_kernel_channel *kchan;
 877
 878                 ksess = session->kernel_session;
 879
 880                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 881                 if (kchan == NULL) {
 882                         ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
 883                         goto error;
 884                 }
 885
 886                 ret = event_kernel_disable_all(ksess, kchan);
 887                 if (ret != LTTCOMM_OK) {
 888                         goto error;
 889                 }
 890
 891                 kernel_wait_quiescent(kernel_tracer_fd);
 892                 break;
 893         }
 894         case LTTNG_DOMAIN_UST:
 895         {
 896                 struct ltt_ust_session *usess;
 897                 struct ltt_ust_channel *uchan;
 898
 899                 usess = session->ust_session;
 900
 901                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 902                                 channel_name);
 903                 if (uchan == NULL) {
 904                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
 905                         goto error;
 906                 }
 907
 908                 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
 909                 if (ret != 0) {
 910                         goto error;
 911                 }
 912
 913                 DBG3("Disable all UST events in channel %s completed", channel_name);
 914
 915                 break;
 916         }
 917 #if 0
 918         case LTTNG_DOMAIN_UST_EXEC_NAME:
 919         case LTTNG_DOMAIN_UST_PID:
 920         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 921 #endif
 922         default:
 923                 ret = LTTCOMM_UND;
 924                 goto error;
 925         }
 926
 927         ret = LTTCOMM_OK;
 928
 929 error:
 930         return ret;
 931 }
 932
 933 /*
 934  * Command LTTNG_ADD_CONTEXT processed by the client thread.
 935  */
 936 int cmd_add_context(struct ltt_session *session, int domain,
 937                 char *channel_name, char *event_name, struct lttng_event_context *ctx)
 938 {
 939         int ret;
 940
 941         switch (domain) {
 942         case LTTNG_DOMAIN_KERNEL:
 943                 /* Add kernel context to kernel tracer */
 944                 ret = context_kernel_add(session->kernel_session, ctx,
 945                                 event_name, channel_name);
 946                 if (ret != LTTCOMM_OK) {
 947                         goto error;
 948                 }
 949                 break;
 950         case LTTNG_DOMAIN_UST:
 951         {
 952                 struct ltt_ust_session *usess = session->ust_session;
 953
 954                 assert(usess);
 955
 956                 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
 957                 if (ret != LTTCOMM_OK) {
 958                         goto error;
 959                 }
 960                 break;
 961         }
 962 #if 0
 963         case LTTNG_DOMAIN_UST_EXEC_NAME:
 964         case LTTNG_DOMAIN_UST_PID:
 965         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 966 #endif
 967         default:
 968                 ret = LTTCOMM_UND;
 969                 goto error;
 970         }
 971
 972         ret = LTTCOMM_OK;
 973
 974 error:
 975         return ret;
 976 }
 977
 978 /*
 979  * Command LTTNG_SET_FILTER processed by the client thread.
 980  */
 981 int cmd_set_filter(struct ltt_session *session, int domain,
 982                 char *channel_name, char *event_name,
 983                 struct lttng_filter_bytecode *bytecode)
 984 {
 985         int ret;
 986
 987         switch (domain) {
 988         case LTTNG_DOMAIN_KERNEL:
 989                 ret = LTTCOMM_FATAL;
 990                 break;
 991         case LTTNG_DOMAIN_UST:
 992         {
 993                 struct ltt_ust_session *usess = session->ust_session;
 994
 995                 ret = filter_ust_set(usess, domain, bytecode, event_name, channel_name);
 996                 if (ret != LTTCOMM_OK) {
 997                         goto error;
 998                 }
 999                 break;
1000         }
1001 #if 0
1002         case LTTNG_DOMAIN_UST_EXEC_NAME:
1003         case LTTNG_DOMAIN_UST_PID:
1004         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1005 #endif
1006         default:
1007                 ret = LTTCOMM_UND;
1008                 goto error;
1009         }
1010
1011         ret = LTTCOMM_OK;
1012
1013 error:
1014         return ret;
1015
1016 }
1017
1018
1019 /*
1020  * Command LTTNG_ENABLE_EVENT processed by the client thread.
1021  */
1022 int cmd_enable_event(struct ltt_session *session, int domain,
1023                 char *channel_name, struct lttng_event *event, int wpipe)
1024 {
1025         int ret;
1026         struct lttng_channel *attr;
1027
1028         assert(session);
1029         assert(event);
1030         assert(channel_name);
1031
1032         switch (domain) {
1033         case LTTNG_DOMAIN_KERNEL:
1034         {
1035                 struct ltt_kernel_channel *kchan;
1036
1037                 kchan = trace_kernel_get_channel_by_name(channel_name,
1038                                 session->kernel_session);
1039                 if (kchan == NULL) {
1040                         attr = channel_new_default_attr(domain);
1041                         if (attr == NULL) {
1042                                 ret = LTTCOMM_FATAL;
1043                                 goto error;
1044                         }
1045                         strncpy(attr->name, channel_name, sizeof(attr->name));
1046
1047                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1048                         if (ret != LTTCOMM_OK) {
1049                                 free(attr);
1050                                 goto error;
1051                         }
1052                         free(attr);
1053                 }
1054
1055                 /* Get the newly created kernel channel pointer */
1056                 kchan = trace_kernel_get_channel_by_name(channel_name,
1057                                 session->kernel_session);
1058                 if (kchan == NULL) {
1059                         /* This sould not happen... */
1060                         ret = LTTCOMM_FATAL;
1061                         goto error;
1062                 }
1063
1064                 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
1065                                 event);
1066                 if (ret != LTTCOMM_OK) {
1067                         goto error;
1068                 }
1069
1070                 kernel_wait_quiescent(kernel_tracer_fd);
1071                 break;
1072         }
1073         case LTTNG_DOMAIN_UST:
1074         {
1075                 struct ltt_ust_channel *uchan;
1076                 struct ltt_ust_session *usess = session->ust_session;
1077
1078                 assert(usess);
1079
1080                 /* Get channel from global UST domain */
1081                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1082                                 channel_name);
1083                 if (uchan == NULL) {
1084                         /* Create default channel */
1085                         attr = channel_new_default_attr(domain);
1086                         if (attr == NULL) {
1087                                 ret = LTTCOMM_FATAL;
1088                                 goto error;
1089                         }
1090                         strncpy(attr->name, channel_name, sizeof(attr->name));
1091
1092                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1093                         if (ret != LTTCOMM_OK) {
1094                                 free(attr);
1095                                 goto error;
1096                         }
1097                         free(attr);
1098
1099                         /* Get the newly created channel reference back */
1100                         uchan = trace_ust_find_channel_by_name(
1101                                         usess->domain_global.channels, channel_name);
1102                         assert(uchan);
1103                 }
1104
1105                 /* At this point, the session and channel exist on the tracer */
1106                 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
1107                 if (ret != LTTCOMM_OK) {
1108                         goto error;
1109                 }
1110                 break;
1111         }
1112 #if 0
1113         case LTTNG_DOMAIN_UST_EXEC_NAME:
1114         case LTTNG_DOMAIN_UST_PID:
1115         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1116 #endif
1117         default:
1118                 ret = LTTCOMM_UND;
1119                 goto error;
1120         }
1121
1122         ret = LTTCOMM_OK;
1123
1124 error:
1125         return ret;
1126 }
1127
1128 /*
1129  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1130  */
1131 int cmd_enable_event_all(struct ltt_session *session, int domain,
1132                 char *channel_name, int event_type, int wpipe)
1133 {
1134         int ret;
1135         struct lttng_channel *attr;
1136
1137         assert(session);
1138         assert(channel_name);
1139
1140         switch (domain) {
1141         case LTTNG_DOMAIN_KERNEL:
1142         {
1143                 struct ltt_kernel_channel *kchan;
1144
1145                 assert(session->kernel_session);
1146
1147                 kchan = trace_kernel_get_channel_by_name(channel_name,
1148                                 session->kernel_session);
1149                 if (kchan == NULL) {
1150                         /* Create default channel */
1151                         attr = channel_new_default_attr(domain);
1152                         if (attr == NULL) {
1153                                 ret = LTTCOMM_FATAL;
1154                                 goto error;
1155                         }
1156                         strncpy(attr->name, channel_name, sizeof(attr->name));
1157
1158                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1159                         if (ret != LTTCOMM_OK) {
1160                                 free(attr);
1161                                 goto error;
1162                         }
1163                         free(attr);
1164
1165                         /* Get the newly created kernel channel pointer */
1166                         kchan = trace_kernel_get_channel_by_name(channel_name,
1167                                         session->kernel_session);
1168                         assert(kchan);
1169                 }
1170
1171                 switch (event_type) {
1172                 case LTTNG_EVENT_SYSCALL:
1173                         ret = event_kernel_enable_all_syscalls(session->kernel_session,
1174                                         kchan, kernel_tracer_fd);
1175                         break;
1176                 case LTTNG_EVENT_TRACEPOINT:
1177                         /*
1178                          * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1179                          * events already registered to the channel.
1180                          */
1181                         ret = event_kernel_enable_all_tracepoints(session->kernel_session,
1182                                         kchan, kernel_tracer_fd);
1183                         break;
1184                 case LTTNG_EVENT_ALL:
1185                         /* Enable syscalls and tracepoints */
1186                         ret = event_kernel_enable_all(session->kernel_session,
1187                                         kchan, kernel_tracer_fd);
1188                         break;
1189                 default:
1190                         ret = LTTCOMM_KERN_ENABLE_FAIL;
1191                         goto error;
1192                 }
1193
1194                 /* Manage return value */
1195                 if (ret != LTTCOMM_OK) {
1196                         goto error;
1197                 }
1198
1199                 kernel_wait_quiescent(kernel_tracer_fd);
1200                 break;
1201         }
1202         case LTTNG_DOMAIN_UST:
1203         {
1204                 struct ltt_ust_channel *uchan;
1205                 struct ltt_ust_session *usess = session->ust_session;
1206
1207                 assert(usess);
1208
1209                 /* Get channel from global UST domain */
1210                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1211                                 channel_name);
1212                 if (uchan == NULL) {
1213                         /* Create default channel */
1214                         attr = channel_new_default_attr(domain);
1215                         if (attr == NULL) {
1216                                 ret = LTTCOMM_FATAL;
1217                                 goto error;
1218                         }
1219                         strncpy(attr->name, channel_name, sizeof(attr->name));
1220
1221                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1222                         if (ret != LTTCOMM_OK) {
1223                                 free(attr);
1224                                 goto error;
1225                         }
1226                         free(attr);
1227
1228                         /* Get the newly created channel reference back */
1229                         uchan = trace_ust_find_channel_by_name(
1230                                         usess->domain_global.channels, channel_name);
1231                         assert(uchan);
1232                 }
1233
1234                 /* At this point, the session and channel exist on the tracer */
1235
1236                 switch (event_type) {
1237                 case LTTNG_EVENT_ALL:
1238                 case LTTNG_EVENT_TRACEPOINT:
1239                         ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
1240                         if (ret != LTTCOMM_OK) {
1241                                 goto error;
1242                         }
1243                         break;
1244                 default:
1245                         ret = LTTCOMM_UST_ENABLE_FAIL;
1246                         goto error;
1247                 }
1248
1249                 /* Manage return value */
1250                 if (ret != LTTCOMM_OK) {
1251                         goto error;
1252                 }
1253
1254                 break;
1255         }
1256 #if 0
1257         case LTTNG_DOMAIN_UST_EXEC_NAME:
1258         case LTTNG_DOMAIN_UST_PID:
1259         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1260 #endif
1261         default:
1262                 ret = LTTCOMM_UND;
1263                 goto error;
1264         }
1265
1266         ret = LTTCOMM_OK;
1267
1268 error:
1269         return ret;
1270 }
1271
1272
1273 /*
1274  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1275  */
1276 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1277 {
1278         int ret;
1279         ssize_t nb_events = 0;
1280
1281         switch (domain) {
1282         case LTTNG_DOMAIN_KERNEL:
1283                 nb_events = kernel_list_events(kernel_tracer_fd, events);
1284                 if (nb_events < 0) {
1285                         ret = LTTCOMM_KERN_LIST_FAIL;
1286                         goto error;
1287                 }
1288                 break;
1289         case LTTNG_DOMAIN_UST:
1290                 nb_events = ust_app_list_events(events);
1291                 if (nb_events < 0) {
1292                         ret = LTTCOMM_UST_LIST_FAIL;
1293                         goto error;
1294                 }
1295                 break;
1296         default:
1297                 ret = LTTCOMM_UND;
1298                 goto error;
1299         }
1300
1301         return nb_events;
1302
1303 error:
1304         /* Return negative value to differentiate return code */
1305         return -ret;
1306 }
1307
1308 /*
1309  * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1310  */
1311 ssize_t cmd_list_tracepoint_fields(int domain,
1312                 struct lttng_event_field **fields)
1313 {
1314         int ret;
1315         ssize_t nb_fields = 0;
1316
1317         switch (domain) {
1318         case LTTNG_DOMAIN_UST:
1319                 nb_fields = ust_app_list_event_fields(fields);
1320                 if (nb_fields < 0) {
1321                         ret = LTTCOMM_UST_LIST_FAIL;
1322                         goto error;
1323                 }
1324                 break;
1325         case LTTNG_DOMAIN_KERNEL:
1326         default:        /* fall-through */
1327                 ret = LTTCOMM_UND;
1328                 goto error;
1329         }
1330
1331         return nb_fields;
1332
1333 error:
1334         /* Return negative value to differentiate return code */
1335         return -ret;
1336 }
1337
1338 /*
1339  * Command LTTNG_START_TRACE processed by the client thread.
1340  */
1341 int cmd_start_trace(struct ltt_session *session)
1342 {
1343         int ret;
1344         struct ltt_kernel_session *ksession;
1345         struct ltt_ust_session *usess;
1346         struct ltt_kernel_channel *kchan;
1347
1348         assert(session);
1349
1350         /* Ease our life a bit ;) */
1351         ksession = session->kernel_session;
1352         usess = session->ust_session;
1353
1354         if (session->enabled) {
1355                 /* Already started. */
1356                 ret = LTTCOMM_TRACE_ALREADY_STARTED;
1357                 goto error;
1358         }
1359
1360         session->enabled = 1;
1361
1362         ret = setup_relayd(session);
1363         if (ret != LTTCOMM_OK) {
1364                 ERR("Error setting up relayd for session %s", session->name);
1365                 goto error;
1366         }
1367
1368         /* Kernel tracing */
1369         if (ksession != NULL) {
1370                 /* Open kernel metadata */
1371                 if (ksession->metadata == NULL) {
1372                         ret = kernel_open_metadata(ksession);
1373                         if (ret < 0) {
1374                                 ret = LTTCOMM_KERN_META_FAIL;
1375                                 goto error;
1376                         }
1377                 }
1378
1379                 /* Open kernel metadata stream */
1380                 if (ksession->metadata_stream_fd < 0) {
1381                         ret = kernel_open_metadata_stream(ksession);
1382                         if (ret < 0) {
1383                                 ERR("Kernel create metadata stream failed");
1384                                 ret = LTTCOMM_KERN_STREAM_FAIL;
1385                                 goto error;
1386                         }
1387                 }
1388
1389                 /* For each channel */
1390                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1391                         if (kchan->stream_count == 0) {
1392                                 ret = kernel_open_channel_stream(kchan);
1393                                 if (ret < 0) {
1394                                         ret = LTTCOMM_KERN_STREAM_FAIL;
1395                                         goto error;
1396                                 }
1397                                 /* Update the stream global counter */
1398                                 ksession->stream_count_global += ret;
1399                         }
1400                 }
1401
1402                 /* Setup kernel consumer socket and send fds to it */
1403                 ret = init_kernel_tracing(ksession);
1404                 if (ret < 0) {
1405                         ret = LTTCOMM_KERN_START_FAIL;
1406                         goto error;
1407                 }
1408
1409                 /* This start the kernel tracing */
1410                 ret = kernel_start_session(ksession);
1411                 if (ret < 0) {
1412                         ret = LTTCOMM_KERN_START_FAIL;
1413                         goto error;
1414                 }
1415
1416                 /* Quiescent wait after starting trace */
1417                 kernel_wait_quiescent(kernel_tracer_fd);
1418         }
1419
1420         /* Flag session that trace should start automatically */
1421         if (usess) {
1422                 usess->start_trace = 1;
1423
1424                 ret = ust_app_start_trace_all(usess);
1425                 if (ret < 0) {
1426                         ret = LTTCOMM_UST_START_FAIL;
1427                         goto error;
1428                 }
1429         }
1430
1431         ret = LTTCOMM_OK;
1432
1433 error:
1434         return ret;
1435 }
1436
1437 /*
1438  * Command LTTNG_STOP_TRACE processed by the client thread.
1439  */
1440 int cmd_stop_trace(struct ltt_session *session)
1441 {
1442         int ret;
1443         struct ltt_kernel_channel *kchan;
1444         struct ltt_kernel_session *ksession;
1445         struct ltt_ust_session *usess;
1446
1447         assert(session);
1448
1449         /* Short cut */
1450         ksession = session->kernel_session;
1451         usess = session->ust_session;
1452
1453         if (!session->enabled) {
1454                 ret = LTTCOMM_TRACE_ALREADY_STOPPED;
1455                 goto error;
1456         }
1457
1458         session->enabled = 0;
1459
1460         /* Kernel tracer */
1461         if (ksession) {
1462                 DBG("Stop kernel tracing");
1463
1464                 /* Flush metadata if exist */
1465                 if (ksession->metadata_stream_fd >= 0) {
1466                         ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1467                         if (ret < 0) {
1468                                 ERR("Kernel metadata flush failed");
1469                         }
1470                 }
1471
1472                 /* Flush all buffers before stopping */
1473                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1474                         ret = kernel_flush_buffer(kchan);
1475                         if (ret < 0) {
1476                                 ERR("Kernel flush buffer error");
1477                         }
1478                 }
1479
1480                 ret = kernel_stop_session(ksession);
1481                 if (ret < 0) {
1482                         ret = LTTCOMM_KERN_STOP_FAIL;
1483                         goto error;
1484                 }
1485
1486                 kernel_wait_quiescent(kernel_tracer_fd);
1487         }
1488
1489         if (usess) {
1490                 usess->start_trace = 0;
1491
1492                 ret = ust_app_stop_trace_all(usess);
1493                 if (ret < 0) {
1494                         ret = LTTCOMM_UST_STOP_FAIL;
1495                         goto error;
1496                 }
1497         }
1498
1499         ret = LTTCOMM_OK;
1500
1501 error:
1502         return ret;
1503 }
1504
1505 /*
1506  * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1507  */
1508 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1509                 size_t nb_uri, struct lttng_uri *uris)
1510 {
1511         int ret, i;
1512         struct ltt_kernel_session *ksess = session->kernel_session;
1513         struct ltt_ust_session *usess = session->ust_session;
1514         struct consumer_output *consumer = NULL;
1515
1516         assert(session);
1517         assert(uris);
1518         assert(nb_uri > 0);
1519
1520         /* Can't enable consumer after session started. */
1521         if (session->enabled) {
1522                 ret = LTTCOMM_TRACE_ALREADY_STARTED;
1523                 goto error;
1524         }
1525
1526         if (!session->start_consumer) {
1527                 ret = LTTCOMM_NO_CONSUMER;
1528                 goto error;
1529         }
1530
1531         /*
1532          * This case switch makes sure the domain session has a temporary consumer
1533          * so the URL can be set.
1534          */
1535         switch (domain) {
1536         case 0:
1537                 /* Code flow error. A session MUST always have a consumer object */
1538                 assert(session->consumer);
1539                 /*
1540                  * The URL will be added to the tracing session consumer instead of a
1541                  * specific domain consumer.
1542                  */
1543                 consumer = session->consumer;
1544                 break;
1545         case LTTNG_DOMAIN_KERNEL:
1546                 /* Code flow error if we don't have a kernel session here. */
1547                 assert(ksess);
1548
1549                 /* Create consumer output if none exists */
1550                 consumer = ksess->tmp_consumer;
1551                 if (consumer == NULL) {
1552                         consumer = consumer_copy_output(ksess->consumer);
1553                         if (consumer == NULL) {
1554                                 ret = LTTCOMM_FATAL;
1555                                 goto error;
1556                         }
1557                         /* Trash the consumer subdir, we are about to set a new one. */
1558                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1559                         ksess->tmp_consumer = consumer;
1560                 }
1561
1562                 break;
1563         case LTTNG_DOMAIN_UST:
1564                 /* Code flow error if we don't have a kernel session here. */
1565                 assert(usess);
1566
1567                 /* Create consumer output if none exists */
1568                 consumer = usess->tmp_consumer;
1569                 if (consumer == NULL) {
1570                         consumer = consumer_copy_output(usess->consumer);
1571                         if (consumer == NULL) {
1572                                 ret = LTTCOMM_FATAL;
1573                                 goto error;
1574                         }
1575                         /* Trash the consumer subdir, we are about to set a new one. */
1576                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1577                         usess->tmp_consumer = consumer;
1578                 }
1579
1580                 break;
1581         }
1582
1583         for (i = 0; i < nb_uri; i++) {
1584                 struct consumer_socket *socket;
1585                 struct lttng_ht_iter iter;
1586
1587                 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1588                 if (ret < 0) {
1589                         goto error;
1590                 }
1591
1592                 /*
1593                  * Don't send relayd socket if URI is NOT remote or if the relayd
1594                  * sockets for the session are already sent.
1595                  */
1596                 if (uris[i].dtype == LTTNG_DST_PATH ||
1597                                 consumer->dst.net.relayd_socks_sent) {
1598                         continue;
1599                 }
1600
1601                 /* Try to send relayd URI to the consumer if exist. */
1602                 rcu_read_lock();
1603                 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
1604                                 socket, node.node) {
1605
1606                         /* A socket in the HT should never have a negative fd */
1607                         assert(socket->fd >= 0);
1608
1609                         pthread_mutex_lock(socket->lock);
1610                         ret = send_consumer_relayd_socket(domain, session, &uris[i],
1611                                         consumer, socket->fd);
1612                         pthread_mutex_unlock(socket->lock);
1613                         if (ret != LTTCOMM_OK) {
1614                                 rcu_read_unlock();
1615                                 goto error;
1616                         }
1617                 }
1618                 rcu_read_unlock();
1619         }
1620
1621         /* All good! */
1622         ret = LTTCOMM_OK;
1623
1624 error:
1625         return ret;
1626 }
1627
1628 /*
1629  * Command LTTNG_CREATE_SESSION processed by the client thread.
1630  */
1631 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1632                 size_t nb_uri, lttng_sock_cred *creds)
1633 {
1634         int ret;
1635         char *path = NULL;
1636         struct ltt_session *session;
1637
1638         assert(name);
1639
1640         /*
1641          * Verify if the session already exist
1642          *
1643          * XXX: There is no need for the session lock list here since the caller
1644          * (process_client_msg) is holding it. We might want to change that so a
1645          * single command does not lock the entire session list.
1646          */
1647         session = session_find_by_name(name);
1648         if (session != NULL) {
1649                 ret = LTTCOMM_EXIST_SESS;
1650                 goto find_error;
1651         }
1652
1653         /* Create tracing session in the registry */
1654         ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1655                         LTTNG_SOCK_GET_GID_CRED(creds));
1656         if (ret != LTTCOMM_OK) {
1657                 goto session_error;
1658         }
1659
1660         /*
1661          * Get the newly created session pointer back
1662          *
1663          * XXX: There is no need for the session lock list here since the caller
1664          * (process_client_msg) is holding it. We might want to change that so a
1665          * single command does not lock the entire session list.
1666          */
1667         session = session_find_by_name(name);
1668         assert(session);
1669
1670         /* Create default consumer output for the session not yet created. */
1671         session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1672         if (session->consumer == NULL) {
1673                 ret = LTTCOMM_FATAL;
1674                 goto consumer_error;
1675         }
1676
1677         /*
1678          * This means that the lttng_create_session call was called with the _path_
1679          * argument set to NULL.
1680          */
1681         if (uris == NULL) {
1682                 /*
1683                  * At this point, we'll skip the consumer URI setup and create a
1684                  * session with a NULL path which will flag the session to NOT spawn a
1685                  * consumer.
1686                  */
1687                 DBG("Create session %s with NO uri, skipping consumer setup", name);
1688                 goto end;
1689         }
1690
1691         session->start_consumer = 1;
1692
1693         ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1694         if (ret != LTTCOMM_OK) {
1695                 goto consumer_error;
1696         }
1697
1698         session->consumer->enabled = 1;
1699
1700 end:
1701         return LTTCOMM_OK;
1702
1703 consumer_error:
1704         session_destroy(session);
1705 session_error:
1706 find_error:
1707         return ret;
1708 }
1709
1710 /*
1711  * Command LTTNG_DESTROY_SESSION processed by the client thread.
1712  */
1713 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1714 {
1715         int ret;
1716         struct ltt_ust_session *usess;
1717         struct ltt_kernel_session *ksess;
1718
1719         /* Safety net */
1720         assert(session);
1721
1722         usess = session->ust_session;
1723         ksess = session->kernel_session;
1724
1725         /* Clean kernel session teardown */
1726         kernel_destroy_session(ksess);
1727
1728         /* UST session teardown */
1729         if (usess) {
1730                 /* Close any relayd session */
1731                 consumer_output_send_destroy_relayd(usess->consumer);
1732
1733                 /* Destroy every UST application related to this session. */
1734                 ret = ust_app_destroy_trace_all(usess);
1735                 if (ret) {
1736                         ERR("Error in ust_app_destroy_trace_all");
1737                 }
1738
1739                 /* Clean up the rest. */
1740                 trace_ust_destroy_session(usess);
1741         }
1742
1743         /*
1744          * Must notify the kernel thread here to update it's poll set in order to
1745          * remove the channel(s)' fd just destroyed.
1746          */
1747         ret = notify_thread_pipe(wpipe);
1748         if (ret < 0) {
1749                 PERROR("write kernel poll pipe");
1750         }
1751
1752         ret = session_destroy(session);
1753
1754         return ret;
1755 }
1756
1757 /*
1758  * Command LTTNG_CALIBRATE processed by the client thread.
1759  */
1760 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1761 {
1762         int ret;
1763
1764         switch (domain) {
1765         case LTTNG_DOMAIN_KERNEL:
1766         {
1767                 struct lttng_kernel_calibrate kcalibrate;
1768
1769                 kcalibrate.type = calibrate->type;
1770                 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1771                 if (ret < 0) {
1772                         ret = LTTCOMM_KERN_ENABLE_FAIL;
1773                         goto error;
1774                 }
1775                 break;
1776         }
1777         case LTTNG_DOMAIN_UST:
1778         {
1779                 struct lttng_ust_calibrate ucalibrate;
1780
1781                 ucalibrate.type = calibrate->type;
1782                 ret = ust_app_calibrate_glb(&ucalibrate);
1783                 if (ret < 0) {
1784                         ret = LTTCOMM_UST_CALIBRATE_FAIL;
1785                         goto error;
1786                 }
1787                 break;
1788         }
1789         default:
1790                 ret = LTTCOMM_UND;
1791                 goto error;
1792         }
1793
1794         ret = LTTCOMM_OK;
1795
1796 error:
1797         return ret;
1798 }
1799
1800 /*
1801  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1802  */
1803 int cmd_register_consumer(struct ltt_session *session, int domain,
1804                 const char *sock_path, struct consumer_data *cdata)
1805 {
1806         int ret, sock;
1807         struct consumer_socket *socket;
1808
1809         assert(session);
1810         assert(cdata);
1811         assert(sock_path);
1812
1813         switch (domain) {
1814         case LTTNG_DOMAIN_KERNEL:
1815         {
1816                 struct ltt_kernel_session *ksess = session->kernel_session;
1817
1818                 assert(ksess);
1819
1820                 /* Can't register a consumer if there is already one */
1821                 if (ksess->consumer_fds_sent != 0) {
1822                         ret = LTTCOMM_KERN_CONSUMER_FAIL;
1823                         goto error;
1824                 }
1825
1826                 sock = lttcomm_connect_unix_sock(sock_path);
1827                 if (sock < 0) {
1828                         ret = LTTCOMM_CONNECT_FAIL;
1829                         goto error;
1830                 }
1831
1832                 socket = consumer_allocate_socket(sock);
1833                 if (socket == NULL) {
1834                         ret = LTTCOMM_FATAL;
1835                         close(sock);
1836                         goto error;
1837                 }
1838
1839                 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1840                 if (socket->lock == NULL) {
1841                         PERROR("zmalloc pthread mutex");
1842                         ret = LTTCOMM_FATAL;
1843                         goto error;
1844                 }
1845                 pthread_mutex_init(socket->lock, NULL);
1846                 socket->registered = 1;
1847
1848                 rcu_read_lock();
1849                 consumer_add_socket(socket, ksess->consumer);
1850                 rcu_read_unlock();
1851
1852                 pthread_mutex_lock(&cdata->pid_mutex);
1853                 cdata->pid = -1;
1854                 pthread_mutex_unlock(&cdata->pid_mutex);
1855
1856                 break;
1857         }
1858         default:
1859                 /* TODO: Userspace tracing */
1860                 ret = LTTCOMM_UND;
1861                 goto error;
1862         }
1863
1864         ret = LTTCOMM_OK;
1865
1866 error:
1867         return ret;
1868 }
1869
1870 /*
1871  * Command LTTNG_LIST_DOMAINS processed by the client thread.
1872  */
1873 ssize_t cmd_list_domains(struct ltt_session *session,
1874                 struct lttng_domain **domains)
1875 {
1876         int ret, index = 0;
1877         ssize_t nb_dom = 0;
1878
1879         if (session->kernel_session != NULL) {
1880                 DBG3("Listing domains found kernel domain");
1881                 nb_dom++;
1882         }
1883
1884         if (session->ust_session != NULL) {
1885                 DBG3("Listing domains found UST global domain");
1886                 nb_dom++;
1887         }
1888
1889         *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1890         if (*domains == NULL) {
1891                 ret = -LTTCOMM_FATAL;
1892                 goto error;
1893         }
1894
1895         if (session->kernel_session != NULL) {
1896                 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1897                 index++;
1898         }
1899
1900         if (session->ust_session != NULL) {
1901                 (*domains)[index].type = LTTNG_DOMAIN_UST;
1902                 index++;
1903         }
1904
1905         return nb_dom;
1906
1907 error:
1908         return ret;
1909 }
1910
1911
1912 /*
1913  * Command LTTNG_LIST_CHANNELS processed by the client thread.
1914  */
1915 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
1916                 struct lttng_channel **channels)
1917 {
1918         int ret;
1919         ssize_t nb_chan = 0;
1920
1921         switch (domain) {
1922         case LTTNG_DOMAIN_KERNEL:
1923                 if (session->kernel_session != NULL) {
1924                         nb_chan = session->kernel_session->channel_count;
1925                 }
1926                 DBG3("Number of kernel channels %zd", nb_chan);
1927                 break;
1928         case LTTNG_DOMAIN_UST:
1929                 if (session->ust_session != NULL) {
1930                         nb_chan = lttng_ht_get_count(
1931                                         session->ust_session->domain_global.channels);
1932                 }
1933                 DBG3("Number of UST global channels %zd", nb_chan);
1934                 break;
1935         default:
1936                 *channels = NULL;
1937                 ret = -LTTCOMM_UND;
1938                 goto error;
1939         }
1940
1941         if (nb_chan > 0) {
1942                 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
1943                 if (*channels == NULL) {
1944                         ret = -LTTCOMM_FATAL;
1945                         goto error;
1946                 }
1947
1948                 list_lttng_channels(domain, session, *channels);
1949         } else {
1950                 *channels = NULL;
1951         }
1952
1953         return nb_chan;
1954
1955 error:
1956         return ret;
1957 }
1958
1959 /*
1960  * Command LTTNG_LIST_EVENTS processed by the client thread.
1961  */
1962 ssize_t cmd_list_events(int domain, struct ltt_session *session,
1963                 char *channel_name, struct lttng_event **events)
1964 {
1965         int ret = 0;
1966         ssize_t nb_event = 0;
1967
1968         switch (domain) {
1969         case LTTNG_DOMAIN_KERNEL:
1970                 if (session->kernel_session != NULL) {
1971                         nb_event = list_lttng_kernel_events(channel_name,
1972                                         session->kernel_session, events);
1973                 }
1974                 break;
1975         case LTTNG_DOMAIN_UST:
1976         {
1977                 if (session->ust_session != NULL) {
1978                         nb_event = list_lttng_ust_global_events(channel_name,
1979                                         &session->ust_session->domain_global, events);
1980                 }
1981                 break;
1982         }
1983         default:
1984                 ret = -LTTCOMM_UND;
1985                 goto error;
1986         }
1987
1988         ret = nb_event;
1989
1990 error:
1991         return ret;
1992 }
1993
1994 /*
1995  * Using the session list, filled a lttng_session array to send back to the
1996  * client for session listing.
1997  *
1998  * The session list lock MUST be acquired before calling this function. Use
1999  * session_lock_list() and session_unlock_list().
2000  */
2001 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2002                 gid_t gid)
2003 {
2004         int ret;
2005         unsigned int i = 0;
2006         struct ltt_session *session;
2007         struct ltt_session_list *list = session_get_list();
2008
2009         DBG("Getting all available session for UID %d GID %d",
2010                         uid, gid);
2011         /*
2012          * Iterate over session list and append data after the control struct in
2013          * the buffer.
2014          */
2015         cds_list_for_each_entry(session, &list->head, list) {
2016                 /*
2017                  * Only list the sessions the user can control.
2018                  */
2019                 if (!session_access_ok(session, uid, gid)) {
2020                         continue;
2021                 }
2022
2023                 struct ltt_kernel_session *ksess = session->kernel_session;
2024                 struct ltt_ust_session *usess = session->ust_session;
2025
2026                 if (session->consumer->type == CONSUMER_DST_NET ||
2027                                 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2028                                 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2029                         ret = build_network_session_path(sessions[i].path,
2030                                         sizeof(session[i].path), session);
2031                 } else {
2032                         ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2033                                         session->consumer->dst.trace_path);
2034                 }
2035                 if (ret < 0) {
2036                         PERROR("snprintf session path");
2037                         continue;
2038                 }
2039
2040                 strncpy(sessions[i].name, session->name, NAME_MAX);
2041                 sessions[i].name[NAME_MAX - 1] = '\0';
2042                 sessions[i].enabled = session->enabled;
2043                 i++;
2044         }
2045 }
2046
2047 /*
2048  * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2049  */
2050 int cmd_disable_consumer(int domain, struct ltt_session *session)
2051 {
2052         int ret;
2053         struct ltt_kernel_session *ksess = session->kernel_session;
2054         struct ltt_ust_session *usess = session->ust_session;
2055         struct consumer_output *consumer;
2056
2057         assert(session);
2058
2059         if (session->enabled) {
2060                 /* Can't disable consumer on an already started session */
2061                 ret = LTTCOMM_TRACE_ALREADY_STARTED;
2062                 goto error;
2063         }
2064
2065         if (!session->start_consumer) {
2066                 ret = LTTCOMM_NO_CONSUMER;
2067                 goto error;
2068         }
2069
2070         switch (domain) {
2071         case 0:
2072                 DBG("Disable tracing session %s consumer", session->name);
2073                 consumer = session->consumer;
2074                 break;
2075         case LTTNG_DOMAIN_KERNEL:
2076                 /* Code flow error if we don't have a kernel session here. */
2077                 assert(ksess);
2078
2079                 DBG("Disabling kernel consumer");
2080                 consumer = ksess->consumer;
2081
2082                 break;
2083         case LTTNG_DOMAIN_UST:
2084                 /* Code flow error if we don't have a UST session here. */
2085                 assert(usess);
2086
2087                 DBG("Disabling UST consumer");
2088                 consumer = usess->consumer;
2089
2090                 break;
2091         default:
2092                 ret = LTTCOMM_UNKNOWN_DOMAIN;
2093                 goto error;
2094         }
2095
2096         if (consumer) {
2097                 consumer->enabled = 0;
2098                 /* Success at this point */
2099                 ret = LTTCOMM_OK;
2100         } else {
2101                 ret = LTTCOMM_NO_CONSUMER;
2102         }
2103
2104 error:
2105         return ret;
2106 }
2107
2108 /*
2109  * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2110  */
2111 int cmd_enable_consumer(int domain, struct ltt_session *session)
2112 {
2113         int ret;
2114         struct ltt_kernel_session *ksess = session->kernel_session;
2115         struct ltt_ust_session *usess = session->ust_session;
2116         struct consumer_output *consumer = NULL;
2117
2118         assert(session);
2119
2120         /* Can't enable consumer after session started. */
2121         if (session->enabled) {
2122                 ret = LTTCOMM_TRACE_ALREADY_STARTED;
2123                 goto error;
2124         }
2125
2126         if (!session->start_consumer) {
2127                 ret = LTTCOMM_NO_CONSUMER;
2128                 goto error;
2129         }
2130
2131         switch (domain) {
2132         case 0:
2133                 assert(session->consumer);
2134                 consumer = session->consumer;
2135                 break;
2136         case LTTNG_DOMAIN_KERNEL:
2137                 /* Code flow error if we don't have a kernel session here. */
2138                 assert(ksess);
2139
2140                 /*
2141                  * Check if we have already sent fds to the consumer. In that case,
2142                  * the enable-consumer command can't be used because a start trace
2143                  * had previously occured.
2144                  */
2145                 if (ksess->consumer_fds_sent) {
2146                         ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2147                         goto error;
2148                 }
2149
2150                 consumer = ksess->tmp_consumer;
2151                 if (consumer == NULL) {
2152                         ret = LTTCOMM_OK;
2153                         /* No temp. consumer output exists. Using the current one. */
2154                         DBG3("No temporary consumer. Using default");
2155                         consumer = ksess->consumer;
2156                         goto error;
2157                 }
2158
2159                 switch (consumer->type) {
2160                 case CONSUMER_DST_LOCAL:
2161                         DBG2("Consumer output is local. Creating directory(ies)");
2162
2163                         /* Create directory(ies) */
2164                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2165                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2166                         if (ret < 0) {
2167                                 if (ret != -EEXIST) {
2168                                         ERR("Trace directory creation error");
2169                                         ret = LTTCOMM_FATAL;
2170                                         goto error;
2171                                 }
2172                         }
2173                         break;
2174                 case CONSUMER_DST_NET:
2175                         DBG2("Consumer output is network. Validating URIs");
2176                         /* Validate if we have both control and data path set. */
2177                         if (!consumer->dst.net.control_isset) {
2178                                 ret = LTTCOMM_URL_CTRL_MISS;
2179                                 goto error;
2180                         }
2181
2182                         if (!consumer->dst.net.data_isset) {
2183                                 ret = LTTCOMM_URL_DATA_MISS;
2184                                 goto error;
2185                         }
2186
2187                         /* Check established network session state */
2188                         if (session->net_handle == 0) {
2189                                 ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2190                                 ERR("Session network handle is not set on enable-consumer");
2191                                 goto error;
2192                         }
2193
2194                         break;
2195                 }
2196
2197                 /* Append default kernel trace dir to subdir */
2198                 strncat(ksess->consumer->subdir, DEFAULT_KERNEL_TRACE_DIR,
2199                                 sizeof(ksess->consumer->subdir));
2200
2201                 /*
2202                  * @session-lock
2203                  * This is race free for now since the session lock is acquired before
2204                  * ending up in this function. No other threads can access this kernel
2205                  * session without this lock hence freeing the consumer output object
2206                  * is valid.
2207                  */
2208                 rcu_read_lock();
2209                 consumer_destroy_output(ksess->consumer);
2210                 rcu_read_unlock();
2211                 ksess->consumer = consumer;
2212                 ksess->tmp_consumer = NULL;
2213
2214                 break;
2215         case LTTNG_DOMAIN_UST:
2216                 /* Code flow error if we don't have a UST session here. */
2217                 assert(usess);
2218
2219                 /*
2220                  * Check if we have already sent fds to the consumer. In that case,
2221                  * the enable-consumer command can't be used because a start trace
2222                  * had previously occured.
2223                  */
2224                 if (usess->start_trace) {
2225                         ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2226                         goto error;
2227                 }
2228
2229                 consumer = usess->tmp_consumer;
2230                 if (consumer == NULL) {
2231                         ret = LTTCOMM_OK;
2232                         /* No temp. consumer output exists. Using the current one. */
2233                         DBG3("No temporary consumer. Using default");
2234                         consumer = usess->consumer;
2235                         goto error;
2236                 }
2237
2238                 switch (consumer->type) {
2239                 case CONSUMER_DST_LOCAL:
2240                         DBG2("Consumer output is local. Creating directory(ies)");
2241
2242                         /* Create directory(ies) */
2243                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2244                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2245                         if (ret < 0) {
2246                                 if (ret != -EEXIST) {
2247                                         ERR("Trace directory creation error");
2248                                         ret = LTTCOMM_FATAL;
2249                                         goto error;
2250                                 }
2251                         }
2252                         break;
2253                 case CONSUMER_DST_NET:
2254                         DBG2("Consumer output is network. Validating URIs");
2255                         /* Validate if we have both control and data path set. */
2256                         if (!consumer->dst.net.control_isset) {
2257                                 ret = LTTCOMM_URL_CTRL_MISS;
2258                                 goto error;
2259                         }
2260
2261                         if (!consumer->dst.net.data_isset) {
2262                                 ret = LTTCOMM_URL_DATA_MISS;
2263                                 goto error;
2264                         }
2265
2266                         /* Check established network session state */
2267                         if (session->net_handle == 0) {
2268                                 ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2269                                 DBG2("Session network handle is not set on enable-consumer");
2270                                 goto error;
2271                         }
2272
2273                         if (consumer->net_seq_index == -1) {
2274                                 ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2275                                 DBG2("Network index is not set on the consumer");
2276                                 goto error;
2277                         }
2278
2279                         break;
2280                 }
2281
2282                 /* Append default kernel trace dir to subdir */
2283                 strncat(usess->consumer->subdir, DEFAULT_UST_TRACE_DIR,
2284                                 sizeof(usess->consumer->subdir));
2285
2286                 /*
2287                  * @session-lock
2288                  * This is race free for now since the session lock is acquired before
2289                  * ending up in this function. No other threads can access this kernel
2290                  * session without this lock hence freeing the consumer output object
2291                  * is valid.
2292                  */
2293                 rcu_read_lock();
2294                 consumer_destroy_output(usess->consumer);
2295                 rcu_read_unlock();
2296                 usess->consumer = consumer;
2297                 usess->tmp_consumer = NULL;
2298
2299                 break;
2300         }
2301
2302         /* Enable it */
2303         if (consumer) {
2304                 consumer->enabled = 1;
2305                 /* Success at this point */
2306                 ret = LTTCOMM_OK;
2307         } else {
2308                 /* Should not really happend... */
2309                 ret = LTTCOMM_NO_CONSUMER;
2310         }
2311
2312 error:
2313         return ret;
2314 }
2315
2316 /*
2317  * Init command subsystem.
2318  */
2319 void cmd_init(void)
2320 {
2321         /*
2322          * Set network sequence index to 1 for streams to match a relayd socket on
2323          * the consumer side.
2324          */
2325         uatomic_set(&relayd_net_seq_idx, 1);
2326
2327         DBG("Command subsystem initialized");
2328 }