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         /*
 105          * Do we have a UST url set. If yes, this means we have both kernel and UST
 106          * to print.
 107          */
 108         if (strlen(tmp_uurl) > 0) {
 109                 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
 110                                 tmp_urls, kdata_port, tmp_uurl, udata_port);
 111         } else {
 112                 int dport;
 113                 if (kuri) {
 114                         dport = kdata_port;
 115                 } else {
 116                         /* No kernel URI, use the UST port. */
 117                         dport = udata_port;
 118                 }
 119                 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
 120         }
 121
 122 error:
 123         return ret;
 124 }
 125
 126 /*
 127  * Fill lttng_channel array of all channels.
 128  */
 129 static void list_lttng_channels(int domain, struct ltt_session *session,
 130                 struct lttng_channel *channels)
 131 {
 132         int i = 0;
 133         struct ltt_kernel_channel *kchan;
 134
 135         DBG("Listing channels for session %s", session->name);
 136
 137         switch (domain) {
 138         case LTTNG_DOMAIN_KERNEL:
 139                 /* Kernel channels */
 140                 if (session->kernel_session != NULL) {
 141                         cds_list_for_each_entry(kchan,
 142                                         &session->kernel_session->channel_list.head, list) {
 143                                 /* Copy lttng_channel struct to array */
 144                                 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
 145                                 channels[i].enabled = kchan->enabled;
 146                                 i++;
 147                         }
 148                 }
 149                 break;
 150         case LTTNG_DOMAIN_UST:
 151         {
 152                 struct lttng_ht_iter iter;
 153                 struct ltt_ust_channel *uchan;
 154
 155                 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
 156                                 &iter.iter, uchan, node.node) {
 157                         strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
 158                         channels[i].attr.overwrite = uchan->attr.overwrite;
 159                         channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
 160                         channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
 161                         channels[i].attr.switch_timer_interval =
 162                                 uchan->attr.switch_timer_interval;
 163                         channels[i].attr.read_timer_interval =
 164                                 uchan->attr.read_timer_interval;
 165                         channels[i].enabled = uchan->enabled;
 166                         switch (uchan->attr.output) {
 167                         case LTTNG_UST_MMAP:
 168                         default:
 169                                 channels[i].attr.output = LTTNG_EVENT_MMAP;
 170                                 break;
 171                         }
 172                         i++;
 173                 }
 174                 break;
 175         }
 176         default:
 177                 break;
 178         }
 179 }
 180
 181 /*
 182  * Create a list of ust global domain events.
 183  */
 184 static int list_lttng_ust_global_events(char *channel_name,
 185                 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
 186 {
 187         int i = 0, ret = 0;
 188         unsigned int nb_event = 0;
 189         struct lttng_ht_iter iter;
 190         struct lttng_ht_node_str *node;
 191         struct ltt_ust_channel *uchan;
 192         struct ltt_ust_event *uevent;
 193         struct lttng_event *tmp;
 194
 195         DBG("Listing UST global events for channel %s", channel_name);
 196
 197         rcu_read_lock();
 198
 199         lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
 200         node = lttng_ht_iter_get_node_str(&iter);
 201         if (node == NULL) {
 202                 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 203                 goto error;
 204         }
 205
 206         uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
 207
 208         nb_event += lttng_ht_get_count(uchan->events);
 209
 210         if (nb_event == 0) {
 211                 ret = nb_event;
 212                 goto error;
 213         }
 214
 215         DBG3("Listing UST global %d events", nb_event);
 216
 217         tmp = zmalloc(nb_event * sizeof(struct lttng_event));
 218         if (tmp == NULL) {
 219                 ret = LTTNG_ERR_FATAL;
 220                 goto error;
 221         }
 222
 223         cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
 224                 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
 225                 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 226                 tmp[i].enabled = uevent->enabled;
 227
 228                 switch (uevent->attr.instrumentation) {
 229                 case LTTNG_UST_TRACEPOINT:
 230                         tmp[i].type = LTTNG_EVENT_TRACEPOINT;
 231                         break;
 232                 case LTTNG_UST_PROBE:
 233                         tmp[i].type = LTTNG_EVENT_PROBE;
 234                         break;
 235                 case LTTNG_UST_FUNCTION:
 236                         tmp[i].type = LTTNG_EVENT_FUNCTION;
 237                         break;
 238                 }
 239
 240                 tmp[i].loglevel = uevent->attr.loglevel;
 241                 switch (uevent->attr.loglevel_type) {
 242                 case LTTNG_UST_LOGLEVEL_ALL:
 243                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 244                         break;
 245                 case LTTNG_UST_LOGLEVEL_RANGE:
 246                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 247                         break;
 248                 case LTTNG_UST_LOGLEVEL_SINGLE:
 249                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 250                         break;
 251                 }
 252                 if (uevent->filter) {
 253                         tmp[i].filter = 1;
 254                 }
 255                 i++;
 256         }
 257
 258         ret = nb_event;
 259         *events = tmp;
 260
 261 error:
 262         rcu_read_unlock();
 263         return ret;
 264 }
 265
 266 /*
 267  * Fill lttng_event array of all kernel events in the channel.
 268  */
 269 static int list_lttng_kernel_events(char *channel_name,
 270                 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
 271 {
 272         int i = 0, ret;
 273         unsigned int nb_event;
 274         struct ltt_kernel_event *event;
 275         struct ltt_kernel_channel *kchan;
 276
 277         kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
 278         if (kchan == NULL) {
 279                 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 280                 goto error;
 281         }
 282
 283         nb_event = kchan->event_count;
 284
 285         DBG("Listing events for channel %s", kchan->channel->name);
 286
 287         if (nb_event == 0) {
 288                 goto end;
 289         }
 290
 291         *events = zmalloc(nb_event * sizeof(struct lttng_event));
 292         if (*events == NULL) {
 293                 ret = LTTNG_ERR_FATAL;
 294                 goto error;
 295         }
 296
 297         /* Kernel channels */
 298         cds_list_for_each_entry(event, &kchan->events_list.head , list) {
 299                 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
 300                 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 301                 (*events)[i].enabled = event->enabled;
 302
 303                 switch (event->event->instrumentation) {
 304                 case LTTNG_KERNEL_TRACEPOINT:
 305                         (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
 306                         break;
 307                 case LTTNG_KERNEL_KPROBE:
 308                 case LTTNG_KERNEL_KRETPROBE:
 309                         (*events)[i].type = LTTNG_EVENT_PROBE;
 310                         memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
 311                                         sizeof(struct lttng_kernel_kprobe));
 312                         break;
 313                 case LTTNG_KERNEL_FUNCTION:
 314                         (*events)[i].type = LTTNG_EVENT_FUNCTION;
 315                         memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
 316                                         sizeof(struct lttng_kernel_function));
 317                         break;
 318                 case LTTNG_KERNEL_NOOP:
 319                         (*events)[i].type = LTTNG_EVENT_NOOP;
 320                         break;
 321                 case LTTNG_KERNEL_SYSCALL:
 322                         (*events)[i].type = LTTNG_EVENT_SYSCALL;
 323                         break;
 324                 case LTTNG_KERNEL_ALL:
 325                         assert(0);
 326                         break;
 327                 }
 328                 i++;
 329         }
 330
 331 end:
 332         return nb_event;
 333
 334 error:
 335         /* Negate the error code to differentiate the size from an error */
 336         return -ret;
 337 }
 338
 339 /*
 340  * Add URI so the consumer output object. Set the correct path depending on the
 341  * domain adding the default trace directory.
 342  */
 343 static int add_uri_to_consumer(struct consumer_output *consumer,
 344                 struct lttng_uri *uri, int domain, const char *session_name)
 345 {
 346         int ret = LTTNG_OK;
 347         const char *default_trace_dir;
 348
 349         assert(uri);
 350
 351         if (consumer == NULL) {
 352                 DBG("No consumer detected. Don't add URI. Stopping.");
 353                 ret = LTTNG_ERR_NO_CONSUMER;
 354                 goto error;
 355         }
 356
 357         switch (domain) {
 358         case LTTNG_DOMAIN_KERNEL:
 359                 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
 360                 break;
 361         case LTTNG_DOMAIN_UST:
 362                 default_trace_dir = DEFAULT_UST_TRACE_DIR;
 363                 break;
 364         default:
 365                 /*
 366                  * This case is possible is we try to add the URI to the global tracing
 367                  * session consumer object which in this case there is no subdir.
 368                  */
 369                 default_trace_dir = "";
 370         }
 371
 372         switch (uri->dtype) {
 373         case LTTNG_DST_IPV4:
 374         case LTTNG_DST_IPV6:
 375                 DBG2("Setting network URI to consumer");
 376
 377                 /* Set URI into consumer output object */
 378                 ret = consumer_set_network_uri(consumer, uri);
 379                 if (ret < 0) {
 380                         ret = LTTNG_ERR_FATAL;
 381                         goto error;
 382                 } else if (ret == 1) {
 383                         /*
 384                          * URI was the same in the consumer so we do not append the subdir
 385                          * again so to not duplicate output dir.
 386                          */
 387                         goto error;
 388                 }
 389
 390                 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
 391                         ret = consumer_set_subdir(consumer, session_name);
 392                         if (ret < 0) {
 393                                 ret = LTTNG_ERR_FATAL;
 394                                 goto error;
 395                         }
 396                 }
 397
 398                 if (uri->stype == LTTNG_STREAM_CONTROL) {
 399                         /* On a new subdir, reappend the default trace dir. */
 400                         strncat(consumer->subdir, default_trace_dir,
 401                                         sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
 402                         DBG3("Append domain trace name to subdir %s", consumer->subdir);
 403                 }
 404
 405                 break;
 406         case LTTNG_DST_PATH:
 407                 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
 408                 memset(consumer->dst.trace_path, 0,
 409                                 sizeof(consumer->dst.trace_path));
 410                 strncpy(consumer->dst.trace_path, uri->dst.path,
 411                                 sizeof(consumer->dst.trace_path));
 412                 /* Append default trace dir */
 413                 strncat(consumer->dst.trace_path, default_trace_dir,
 414                                 sizeof(consumer->dst.trace_path) -
 415                                 strlen(consumer->dst.trace_path) - 1);
 416                 /* Flag consumer as local. */
 417                 consumer->type = CONSUMER_DST_LOCAL;
 418                 break;
 419         }
 420
 421 error:
 422         return ret;
 423 }
 424
 425 /*
 426  * Init tracing by creating trace directory and sending fds kernel consumer.
 427  */
 428 static int init_kernel_tracing(struct ltt_kernel_session *session)
 429 {
 430         int ret = 0;
 431         struct lttng_ht_iter iter;
 432         struct consumer_socket *socket;
 433
 434         assert(session);
 435
 436         if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
 437                 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
 438                                 socket, node.node) {
 439                         /* Code flow error */
 440                         assert(socket->fd >= 0);
 441
 442                         pthread_mutex_lock(socket->lock);
 443                         ret = kernel_consumer_send_session(socket->fd, session);
 444                         pthread_mutex_unlock(socket->lock);
 445                         if (ret < 0) {
 446                                 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 447                                 goto error;
 448                         }
 449                 }
 450         }
 451
 452 error:
 453         return ret;
 454 }
 455
 456 /*
 457  * Create a socket to the relayd using the URI.
 458  *
 459  * On success, the relayd_sock pointer is set to the created socket.
 460  * Else, it's stays untouched and a lttcomm error code is returned.
 461  */
 462 static int create_connect_relayd(struct consumer_output *output,
 463                 const char *session_name, struct lttng_uri *uri,
 464                 struct lttcomm_sock **relayd_sock)
 465 {
 466         int ret;
 467         struct lttcomm_sock *sock;
 468
 469         /* Create socket object from URI */
 470         sock = lttcomm_alloc_sock_from_uri(uri);
 471         if (sock == NULL) {
 472                 ret = LTTNG_ERR_FATAL;
 473                 goto error;
 474         }
 475
 476         ret = lttcomm_create_sock(sock);
 477         if (ret < 0) {
 478                 ret = LTTNG_ERR_FATAL;
 479                 goto error;
 480         }
 481
 482         /* Connect to relayd so we can proceed with a session creation. */
 483         ret = relayd_connect(sock);
 484         if (ret < 0) {
 485                 ERR("Unable to reach lttng-relayd");
 486                 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
 487                 goto free_sock;
 488         }
 489
 490         /* Create socket for control stream. */
 491         if (uri->stype == LTTNG_STREAM_CONTROL) {
 492                 DBG3("Creating relayd stream socket from URI");
 493
 494                 /* Check relayd version */
 495                 ret = relayd_version_check(sock, RELAYD_VERSION_COMM_MAJOR,
 496                                 RELAYD_VERSION_COMM_MINOR);
 497                 if (ret < 0) {
 498                         ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
 499                         goto close_sock;
 500                 }
 501         } else if (uri->stype == LTTNG_STREAM_DATA) {
 502                 DBG3("Creating relayd data socket from URI");
 503         } else {
 504                 /* Command is not valid */
 505                 ERR("Relayd invalid stream type: %d", uri->stype);
 506                 ret = LTTNG_ERR_INVALID;
 507                 goto close_sock;
 508         }
 509
 510         *relayd_sock = sock;
 511
 512         return LTTNG_OK;
 513
 514 close_sock:
 515         if (sock) {
 516                 (void) relayd_close(sock);
 517         }
 518 free_sock:
 519         if (sock) {
 520                 lttcomm_destroy_sock(sock);
 521         }
 522 error:
 523         return ret;
 524 }
 525
 526 /*
 527  * Connect to the relayd using URI and send the socket to the right consumer.
 528  */
 529 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
 530                 struct lttng_uri *relayd_uri, struct consumer_output *consumer,
 531                 int consumer_fd)
 532 {
 533         int ret;
 534         struct lttcomm_sock *sock = NULL;
 535
 536         /* Set the network sequence index if not set. */
 537         if (consumer->net_seq_index == -1) {
 538                 /*
 539                  * Increment net_seq_idx because we are about to transfer the
 540                  * new relayd socket to the consumer.
 541                  */
 542                 uatomic_inc(&relayd_net_seq_idx);
 543                 /* Assign unique key so the consumer can match streams */
 544                 uatomic_set(&consumer->net_seq_index,
 545                                 uatomic_read(&relayd_net_seq_idx));
 546         }
 547
 548         /* Connect to relayd and make version check if uri is the control. */
 549         ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
 550         if (ret != LTTNG_OK) {
 551                 goto close_sock;
 552         }
 553
 554         /* If the control socket is connected, network session is ready */
 555         if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
 556                 session->net_handle = 1;
 557         }
 558
 559         /* Send relayd socket to consumer. */
 560         ret = consumer_send_relayd_socket(consumer_fd, sock,
 561                         consumer, relayd_uri->stype);
 562         if (ret < 0) {
 563                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
 564                 goto close_sock;
 565         }
 566
 567         /* Flag that the corresponding socket was sent. */
 568         if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
 569                 consumer->dst.net.control_sock_sent = 1;
 570         } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
 571                 consumer->dst.net.data_sock_sent = 1;
 572         }
 573
 574         ret = LTTNG_OK;
 575
 576         /*
 577          * Close socket which was dup on the consumer side. The session daemon does
 578          * NOT keep track of the relayd socket(s) once transfer to the consumer.
 579          */
 580
 581 close_sock:
 582         if (sock) {
 583                 (void) relayd_close(sock);
 584                 lttcomm_destroy_sock(sock);
 585         }
 586
 587         return ret;
 588 }
 589
 590 /*
 591  * Send both relayd sockets to a specific consumer and domain.  This is a
 592  * helper function to facilitate sending the information to the consumer for a
 593  * session.
 594  */
 595 static int send_consumer_relayd_sockets(int domain,
 596                 struct ltt_session *session, struct consumer_output *consumer, int fd)
 597 {
 598         int ret = LTTNG_OK;
 599
 600         assert(session);
 601         assert(consumer);
 602
 603         /* Sending control relayd socket. */
 604         if (!consumer->dst.net.control_sock_sent) {
 605                 ret = send_consumer_relayd_socket(domain, session,
 606                                 &consumer->dst.net.control, consumer, fd);
 607                 if (ret != LTTNG_OK) {
 608                         goto error;
 609                 }
 610         }
 611
 612         /* Sending data relayd socket. */
 613         if (!consumer->dst.net.data_sock_sent) {
 614                 ret = send_consumer_relayd_socket(domain, session,
 615                                 &consumer->dst.net.data, consumer, fd);
 616                 if (ret != LTTNG_OK) {
 617                         goto error;
 618                 }
 619         }
 620
 621 error:
 622         return ret;
 623 }
 624
 625 /*
 626  * Setup relayd connections for a tracing session. First creates the socket to
 627  * the relayd and send them to the right domain consumer. Consumer type MUST be
 628  * network.
 629  */
 630 static int setup_relayd(struct ltt_session *session)
 631 {
 632         int ret = LTTNG_OK;
 633         struct ltt_ust_session *usess;
 634         struct ltt_kernel_session *ksess;
 635         struct consumer_socket *socket;
 636         struct lttng_ht_iter iter;
 637
 638         assert(session);
 639
 640         usess = session->ust_session;
 641         ksess = session->kernel_session;
 642
 643         DBG2("Setting relayd for session %s", session->name);
 644
 645         if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 646                         && usess->consumer->enabled) {
 647                 /* For each consumer socket, send relayd sockets */
 648                 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
 649                                 socket, node.node) {
 650                         /* Code flow error */
 651                         assert(socket->fd >= 0);
 652
 653                         pthread_mutex_lock(socket->lock);
 654                         ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
 655                                         usess->consumer, socket->fd);
 656                         pthread_mutex_unlock(socket->lock);
 657                         if (ret != LTTNG_OK) {
 658                                 goto error;
 659                         }
 660                 }
 661         }
 662
 663         if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
 664                         && ksess->consumer->enabled) {
 665                 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
 666                                 socket, node.node) {
 667                         /* Code flow error */
 668                         assert(socket->fd >= 0);
 669
 670                         pthread_mutex_lock(socket->lock);
 671                         ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
 672                                         ksess->consumer, socket->fd);
 673                         pthread_mutex_unlock(socket->lock);
 674                         if (ret != LTTNG_OK) {
 675                                 goto error;
 676                         }
 677                 }
 678         }
 679
 680 error:
 681         return ret;
 682 }
 683
 684 /*
 685  * Start a kernel session by opening all necessary streams.
 686  */
 687 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
 688 {
 689         int ret;
 690         struct ltt_kernel_channel *kchan;
 691
 692         /* Open kernel metadata */
 693         if (ksess->metadata == NULL) {
 694                 ret = kernel_open_metadata(ksess);
 695                 if (ret < 0) {
 696                         ret = LTTNG_ERR_KERN_META_FAIL;
 697                         goto error;
 698                 }
 699         }
 700
 701         /* Open kernel metadata stream */
 702         if (ksess->metadata_stream_fd < 0) {
 703                 ret = kernel_open_metadata_stream(ksess);
 704                 if (ret < 0) {
 705                         ERR("Kernel create metadata stream failed");
 706                         ret = LTTNG_ERR_KERN_STREAM_FAIL;
 707                         goto error;
 708                 }
 709         }
 710
 711         /* For each channel */
 712         cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
 713                 if (kchan->stream_count == 0) {
 714                         ret = kernel_open_channel_stream(kchan);
 715                         if (ret < 0) {
 716                                 ret = LTTNG_ERR_KERN_STREAM_FAIL;
 717                                 goto error;
 718                         }
 719                         /* Update the stream global counter */
 720                         ksess->stream_count_global += ret;
 721                 }
 722         }
 723
 724         /* Setup kernel consumer socket and send fds to it */
 725         ret = init_kernel_tracing(ksess);
 726         if (ret < 0) {
 727                 ret = LTTNG_ERR_KERN_START_FAIL;
 728                 goto error;
 729         }
 730
 731         /* This start the kernel tracing */
 732         ret = kernel_start_session(ksess);
 733         if (ret < 0) {
 734                 ret = LTTNG_ERR_KERN_START_FAIL;
 735                 goto error;
 736         }
 737
 738         /* Quiescent wait after starting trace */
 739         kernel_wait_quiescent(kernel_tracer_fd);
 740
 741         ksess->started = 1;
 742
 743         ret = LTTNG_OK;
 744
 745 error:
 746         return ret;
 747 }
 748
 749 /*
 750  * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
 751  */
 752 int cmd_disable_channel(struct ltt_session *session, int domain,
 753                 char *channel_name)
 754 {
 755         int ret;
 756         struct ltt_ust_session *usess;
 757
 758         usess = session->ust_session;
 759
 760         switch (domain) {
 761         case LTTNG_DOMAIN_KERNEL:
 762         {
 763                 ret = channel_kernel_disable(session->kernel_session,
 764                                 channel_name);
 765                 if (ret != LTTNG_OK) {
 766                         goto error;
 767                 }
 768
 769                 kernel_wait_quiescent(kernel_tracer_fd);
 770                 break;
 771         }
 772         case LTTNG_DOMAIN_UST:
 773         {
 774                 struct ltt_ust_channel *uchan;
 775                 struct lttng_ht *chan_ht;
 776
 777                 chan_ht = usess->domain_global.channels;
 778
 779                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 780                 if (uchan == NULL) {
 781                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 782                         goto error;
 783                 }
 784
 785                 ret = channel_ust_disable(usess, domain, uchan);
 786                 if (ret != LTTNG_OK) {
 787                         goto error;
 788                 }
 789                 break;
 790         }
 791 #if 0
 792         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 793         case LTTNG_DOMAIN_UST_EXEC_NAME:
 794         case LTTNG_DOMAIN_UST_PID:
 795 #endif
 796         default:
 797                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 798                 goto error;
 799         }
 800
 801         ret = LTTNG_OK;
 802
 803 error:
 804         return ret;
 805 }
 806
 807 /*
 808  * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
 809  *
 810  * The wpipe arguments is used as a notifier for the kernel thread.
 811  */
 812 int cmd_enable_channel(struct ltt_session *session,
 813                 int domain, struct lttng_channel *attr, int wpipe)
 814 {
 815         int ret;
 816         struct ltt_ust_session *usess = session->ust_session;
 817         struct lttng_ht *chan_ht;
 818
 819         assert(session);
 820         assert(attr);
 821
 822         DBG("Enabling channel %s for session %s", attr->name, session->name);
 823
 824         switch (domain) {
 825         case LTTNG_DOMAIN_KERNEL:
 826         {
 827                 struct ltt_kernel_channel *kchan;
 828
 829                 kchan = trace_kernel_get_channel_by_name(attr->name,
 830                                 session->kernel_session);
 831                 if (kchan == NULL) {
 832                         ret = channel_kernel_create(session->kernel_session, attr, wpipe);
 833                 } else {
 834                         ret = channel_kernel_enable(session->kernel_session, kchan);
 835                 }
 836
 837                 if (ret != LTTNG_OK) {
 838                         goto error;
 839                 }
 840
 841                 kernel_wait_quiescent(kernel_tracer_fd);
 842
 843                 /*
 844                  * If the session was previously started, start as well this newly
 845                  * created kernel session so the events/channels enabled *after* the
 846                  * start actually work.
 847                  */
 848                 if (session->started && !session->kernel_session->started) {
 849                         ret = start_kernel_session(session->kernel_session, wpipe);
 850                         if (ret != LTTNG_OK) {
 851                                 goto error;
 852                         }
 853                 }
 854                 break;
 855         }
 856         case LTTNG_DOMAIN_UST:
 857         {
 858                 struct ltt_ust_channel *uchan;
 859
 860                 chan_ht = usess->domain_global.channels;
 861
 862                 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
 863                 if (uchan == NULL) {
 864                         ret = channel_ust_create(usess, domain, attr);
 865                 } else {
 866                         ret = channel_ust_enable(usess, domain, uchan);
 867                 }
 868
 869                 /* Start the UST session if the session was already started. */
 870                 if (session->started && !usess->start_trace) {
 871                         ret = ust_app_start_trace_all(usess);
 872                         if (ret < 0) {
 873                                 ret = LTTNG_ERR_UST_START_FAIL;
 874                                 goto error;
 875                         }
 876                         ret = LTTNG_OK;
 877                         usess->start_trace = 1;
 878                 }
 879                 break;
 880         }
 881 #if 0
 882         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 883         case LTTNG_DOMAIN_UST_EXEC_NAME:
 884         case LTTNG_DOMAIN_UST_PID:
 885 #endif
 886         default:
 887                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 888                 goto error;
 889         }
 890
 891 error:
 892         return ret;
 893 }
 894
 895
 896 /*
 897  * Command LTTNG_DISABLE_EVENT processed by the client thread.
 898  */
 899 int cmd_disable_event(struct ltt_session *session, int domain,
 900                 char *channel_name, char *event_name)
 901 {
 902         int ret;
 903
 904         switch (domain) {
 905         case LTTNG_DOMAIN_KERNEL:
 906         {
 907                 struct ltt_kernel_channel *kchan;
 908                 struct ltt_kernel_session *ksess;
 909
 910                 ksess = session->kernel_session;
 911
 912                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 913                 if (kchan == NULL) {
 914                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 915                         goto error;
 916                 }
 917
 918                 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
 919                 if (ret != LTTNG_OK) {
 920                         goto error;
 921                 }
 922
 923                 kernel_wait_quiescent(kernel_tracer_fd);
 924                 break;
 925         }
 926         case LTTNG_DOMAIN_UST:
 927         {
 928                 struct ltt_ust_channel *uchan;
 929                 struct ltt_ust_session *usess;
 930
 931                 usess = session->ust_session;
 932
 933                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 934                                 channel_name);
 935                 if (uchan == NULL) {
 936                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 937                         goto error;
 938                 }
 939
 940                 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
 941                 if (ret != LTTNG_OK) {
 942                         goto error;
 943                 }
 944
 945                 DBG3("Disable UST event %s in channel %s completed", event_name,
 946                                 channel_name);
 947                 break;
 948         }
 949 #if 0
 950         case LTTNG_DOMAIN_UST_EXEC_NAME:
 951         case LTTNG_DOMAIN_UST_PID:
 952         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 953 #endif
 954         default:
 955                 ret = LTTNG_ERR_UND;
 956                 goto error;
 957         }
 958
 959         ret = LTTNG_OK;
 960
 961 error:
 962         return ret;
 963 }
 964
 965 /*
 966  * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
 967  */
 968 int cmd_disable_event_all(struct ltt_session *session, int domain,
 969                 char *channel_name)
 970 {
 971         int ret;
 972
 973         switch (domain) {
 974         case LTTNG_DOMAIN_KERNEL:
 975         {
 976                 struct ltt_kernel_session *ksess;
 977                 struct ltt_kernel_channel *kchan;
 978
 979                 ksess = session->kernel_session;
 980
 981                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 982                 if (kchan == NULL) {
 983                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 984                         goto error;
 985                 }
 986
 987                 ret = event_kernel_disable_all(ksess, kchan);
 988                 if (ret != LTTNG_OK) {
 989                         goto error;
 990                 }
 991
 992                 kernel_wait_quiescent(kernel_tracer_fd);
 993                 break;
 994         }
 995         case LTTNG_DOMAIN_UST:
 996         {
 997                 struct ltt_ust_session *usess;
 998                 struct ltt_ust_channel *uchan;
 999
1000                 usess = session->ust_session;
1001
1002                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1003                                 channel_name);
1004                 if (uchan == NULL) {
1005                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1006                         goto error;
1007                 }
1008
1009                 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
1010                 if (ret != 0) {
1011                         goto error;
1012                 }
1013
1014                 DBG3("Disable all UST events in channel %s completed", channel_name);
1015
1016                 break;
1017         }
1018 #if 0
1019         case LTTNG_DOMAIN_UST_EXEC_NAME:
1020         case LTTNG_DOMAIN_UST_PID:
1021         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1022 #endif
1023         default:
1024                 ret = LTTNG_ERR_UND;
1025                 goto error;
1026         }
1027
1028         ret = LTTNG_OK;
1029
1030 error:
1031         return ret;
1032 }
1033
1034 /*
1035  * Command LTTNG_ADD_CONTEXT processed by the client thread.
1036  */
1037 int cmd_add_context(struct ltt_session *session, int domain,
1038                 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1039 {
1040         int ret;
1041
1042         switch (domain) {
1043         case LTTNG_DOMAIN_KERNEL:
1044                 assert(session->kernel_session);
1045
1046                 if (session->kernel_session->channel_count == 0) {
1047                         /* Create default channel */
1048                         ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1049                         if (ret != LTTNG_OK) {
1050                                 goto error;
1051                         }
1052                 }
1053
1054                 /* Add kernel context to kernel tracer */
1055                 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1056                 if (ret != LTTNG_OK) {
1057                         goto error;
1058                 }
1059                 break;
1060         case LTTNG_DOMAIN_UST:
1061         {
1062                 struct ltt_ust_session *usess = session->ust_session;
1063                 assert(usess);
1064
1065                 unsigned int chan_count =
1066                         lttng_ht_get_count(usess->domain_global.channels);
1067                 if (chan_count == 0) {
1068                         struct lttng_channel *attr;
1069                         /* Create default channel */
1070                         attr = channel_new_default_attr(domain);
1071                         if (attr == NULL) {
1072                                 ret = LTTNG_ERR_FATAL;
1073                                 goto error;
1074                         }
1075
1076                         ret = channel_ust_create(usess, domain, attr);
1077                         if (ret != LTTNG_OK) {
1078                                 free(attr);
1079                                 goto error;
1080                         }
1081                         free(attr);
1082                 }
1083
1084                 ret = context_ust_add(usess, domain, ctx, channel_name);
1085                 if (ret != LTTNG_OK) {
1086                         goto error;
1087                 }
1088                 break;
1089         }
1090 #if 0
1091         case LTTNG_DOMAIN_UST_EXEC_NAME:
1092         case LTTNG_DOMAIN_UST_PID:
1093         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1094 #endif
1095         default:
1096                 ret = LTTNG_ERR_UND;
1097                 goto error;
1098         }
1099
1100         ret = LTTNG_OK;
1101
1102 error:
1103         return ret;
1104 }
1105
1106 /*
1107  * Command LTTNG_SET_FILTER processed by the client thread.
1108  */
1109 int cmd_set_filter(struct ltt_session *session, int domain,
1110                 char *channel_name, struct lttng_event *event,
1111                 struct lttng_filter_bytecode *bytecode)
1112 {
1113         int ret;
1114
1115         switch (domain) {
1116         case LTTNG_DOMAIN_KERNEL:
1117                 ret = LTTNG_ERR_FATAL;
1118                 break;
1119         case LTTNG_DOMAIN_UST:
1120         {
1121                 struct ltt_ust_session *usess = session->ust_session;
1122
1123                 ret = filter_ust_set(usess, domain, bytecode, event, channel_name);
1124                 if (ret != LTTNG_OK) {
1125                         goto error;
1126                 }
1127                 break;
1128         }
1129 #if 0
1130         case LTTNG_DOMAIN_UST_EXEC_NAME:
1131         case LTTNG_DOMAIN_UST_PID:
1132         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1133 #endif
1134         default:
1135                 ret = LTTNG_ERR_UND;
1136                 goto error;
1137         }
1138
1139         ret = LTTNG_OK;
1140
1141 error:
1142         return ret;
1143
1144 }
1145
1146
1147 /*
1148  * Command LTTNG_ENABLE_EVENT processed by the client thread.
1149  */
1150 int cmd_enable_event(struct ltt_session *session, int domain,
1151                 char *channel_name, struct lttng_event *event, int wpipe)
1152 {
1153         int ret;
1154         struct lttng_channel *attr;
1155
1156         assert(session);
1157         assert(event);
1158         assert(channel_name);
1159
1160         switch (domain) {
1161         case LTTNG_DOMAIN_KERNEL:
1162         {
1163                 struct ltt_kernel_channel *kchan;
1164
1165                 kchan = trace_kernel_get_channel_by_name(channel_name,
1166                                 session->kernel_session);
1167                 if (kchan == NULL) {
1168                         attr = channel_new_default_attr(domain);
1169                         if (attr == NULL) {
1170                                 ret = LTTNG_ERR_FATAL;
1171                                 goto error;
1172                         }
1173                         strncpy(attr->name, channel_name, sizeof(attr->name));
1174
1175                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1176                         if (ret != LTTNG_OK) {
1177                                 free(attr);
1178                                 goto error;
1179                         }
1180                         free(attr);
1181                 }
1182
1183                 /* Get the newly created kernel channel pointer */
1184                 kchan = trace_kernel_get_channel_by_name(channel_name,
1185                                 session->kernel_session);
1186                 if (kchan == NULL) {
1187                         /* This sould not happen... */
1188                         ret = LTTNG_ERR_FATAL;
1189                         goto error;
1190                 }
1191
1192                 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
1193                                 event);
1194                 if (ret != LTTNG_OK) {
1195                         goto error;
1196                 }
1197
1198                 kernel_wait_quiescent(kernel_tracer_fd);
1199                 break;
1200         }
1201         case LTTNG_DOMAIN_UST:
1202         {
1203                 struct ltt_ust_channel *uchan;
1204                 struct ltt_ust_session *usess = session->ust_session;
1205
1206                 assert(usess);
1207
1208                 /* Get channel from global UST domain */
1209                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1210                                 channel_name);
1211                 if (uchan == NULL) {
1212                         /* Create default channel */
1213                         attr = channel_new_default_attr(domain);
1214                         if (attr == NULL) {
1215                                 ret = LTTNG_ERR_FATAL;
1216                                 goto error;
1217                         }
1218                         strncpy(attr->name, channel_name, sizeof(attr->name));
1219
1220                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1221                         if (ret != LTTNG_OK) {
1222                                 free(attr);
1223                                 goto error;
1224                         }
1225                         free(attr);
1226
1227                         /* Get the newly created channel reference back */
1228                         uchan = trace_ust_find_channel_by_name(
1229                                         usess->domain_global.channels, channel_name);
1230                         assert(uchan);
1231                 }
1232
1233                 /* At this point, the session and channel exist on the tracer */
1234                 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
1235                 if (ret != LTTNG_OK) {
1236                         goto error;
1237                 }
1238                 break;
1239         }
1240 #if 0
1241         case LTTNG_DOMAIN_UST_EXEC_NAME:
1242         case LTTNG_DOMAIN_UST_PID:
1243         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1244 #endif
1245         default:
1246                 ret = LTTNG_ERR_UND;
1247                 goto error;
1248         }
1249
1250         ret = LTTNG_OK;
1251
1252 error:
1253         return ret;
1254 }
1255
1256 /*
1257  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1258  */
1259 int cmd_enable_event_all(struct ltt_session *session, int domain,
1260                 char *channel_name, int event_type, int wpipe)
1261 {
1262         int ret;
1263         struct lttng_channel *attr;
1264
1265         assert(session);
1266         assert(channel_name);
1267
1268         switch (domain) {
1269         case LTTNG_DOMAIN_KERNEL:
1270         {
1271                 struct ltt_kernel_channel *kchan;
1272
1273                 assert(session->kernel_session);
1274
1275                 kchan = trace_kernel_get_channel_by_name(channel_name,
1276                                 session->kernel_session);
1277                 if (kchan == NULL) {
1278                         /* Create default channel */
1279                         attr = channel_new_default_attr(domain);
1280                         if (attr == NULL) {
1281                                 ret = LTTNG_ERR_FATAL;
1282                                 goto error;
1283                         }
1284                         strncpy(attr->name, channel_name, sizeof(attr->name));
1285
1286                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1287                         if (ret != LTTNG_OK) {
1288                                 free(attr);
1289                                 goto error;
1290                         }
1291                         free(attr);
1292
1293                         /* Get the newly created kernel channel pointer */
1294                         kchan = trace_kernel_get_channel_by_name(channel_name,
1295                                         session->kernel_session);
1296                         assert(kchan);
1297                 }
1298
1299                 switch (event_type) {
1300                 case LTTNG_EVENT_SYSCALL:
1301                         ret = event_kernel_enable_all_syscalls(session->kernel_session,
1302                                         kchan, kernel_tracer_fd);
1303                         break;
1304                 case LTTNG_EVENT_TRACEPOINT:
1305                         /*
1306                          * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1307                          * events already registered to the channel.
1308                          */
1309                         ret = event_kernel_enable_all_tracepoints(session->kernel_session,
1310                                         kchan, kernel_tracer_fd);
1311                         break;
1312                 case LTTNG_EVENT_ALL:
1313                         /* Enable syscalls and tracepoints */
1314                         ret = event_kernel_enable_all(session->kernel_session,
1315                                         kchan, kernel_tracer_fd);
1316                         break;
1317                 default:
1318                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1319                         goto error;
1320                 }
1321
1322                 /* Manage return value */
1323                 if (ret != LTTNG_OK) {
1324                         goto error;
1325                 }
1326
1327                 kernel_wait_quiescent(kernel_tracer_fd);
1328                 break;
1329         }
1330         case LTTNG_DOMAIN_UST:
1331         {
1332                 struct ltt_ust_channel *uchan;
1333                 struct ltt_ust_session *usess = session->ust_session;
1334
1335                 assert(usess);
1336
1337                 /* Get channel from global UST domain */
1338                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1339                                 channel_name);
1340                 if (uchan == NULL) {
1341                         /* Create default channel */
1342                         attr = channel_new_default_attr(domain);
1343                         if (attr == NULL) {
1344                                 ret = LTTNG_ERR_FATAL;
1345                                 goto error;
1346                         }
1347                         strncpy(attr->name, channel_name, sizeof(attr->name));
1348
1349                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1350                         if (ret != LTTNG_OK) {
1351                                 free(attr);
1352                                 goto error;
1353                         }
1354                         free(attr);
1355
1356                         /* Get the newly created channel reference back */
1357                         uchan = trace_ust_find_channel_by_name(
1358                                         usess->domain_global.channels, channel_name);
1359                         assert(uchan);
1360                 }
1361
1362                 /* At this point, the session and channel exist on the tracer */
1363
1364                 switch (event_type) {
1365                 case LTTNG_EVENT_ALL:
1366                 case LTTNG_EVENT_TRACEPOINT:
1367                         ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
1368                         if (ret != LTTNG_OK) {
1369                                 goto error;
1370                         }
1371                         break;
1372                 default:
1373                         ret = LTTNG_ERR_UST_ENABLE_FAIL;
1374                         goto error;
1375                 }
1376
1377                 /* Manage return value */
1378                 if (ret != LTTNG_OK) {
1379                         goto error;
1380                 }
1381
1382                 break;
1383         }
1384 #if 0
1385         case LTTNG_DOMAIN_UST_EXEC_NAME:
1386         case LTTNG_DOMAIN_UST_PID:
1387         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1388 #endif
1389         default:
1390                 ret = LTTNG_ERR_UND;
1391                 goto error;
1392         }
1393
1394         ret = LTTNG_OK;
1395
1396 error:
1397         return ret;
1398 }
1399
1400
1401 /*
1402  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1403  */
1404 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1405 {
1406         int ret;
1407         ssize_t nb_events = 0;
1408
1409         switch (domain) {
1410         case LTTNG_DOMAIN_KERNEL:
1411                 nb_events = kernel_list_events(kernel_tracer_fd, events);
1412                 if (nb_events < 0) {
1413                         ret = LTTNG_ERR_KERN_LIST_FAIL;
1414                         goto error;
1415                 }
1416                 break;
1417         case LTTNG_DOMAIN_UST:
1418                 nb_events = ust_app_list_events(events);
1419                 if (nb_events < 0) {
1420                         ret = LTTNG_ERR_UST_LIST_FAIL;
1421                         goto error;
1422                 }
1423                 break;
1424         default:
1425                 ret = LTTNG_ERR_UND;
1426                 goto error;
1427         }
1428
1429         return nb_events;
1430
1431 error:
1432         /* Return negative value to differentiate return code */
1433         return -ret;
1434 }
1435
1436 /*
1437  * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1438  */
1439 ssize_t cmd_list_tracepoint_fields(int domain,
1440                 struct lttng_event_field **fields)
1441 {
1442         int ret;
1443         ssize_t nb_fields = 0;
1444
1445         switch (domain) {
1446         case LTTNG_DOMAIN_UST:
1447                 nb_fields = ust_app_list_event_fields(fields);
1448                 if (nb_fields < 0) {
1449                         ret = LTTNG_ERR_UST_LIST_FAIL;
1450                         goto error;
1451                 }
1452                 break;
1453         case LTTNG_DOMAIN_KERNEL:
1454         default:        /* fall-through */
1455                 ret = LTTNG_ERR_UND;
1456                 goto error;
1457         }
1458
1459         return nb_fields;
1460
1461 error:
1462         /* Return negative value to differentiate return code */
1463         return -ret;
1464 }
1465
1466 /*
1467  * Command LTTNG_START_TRACE processed by the client thread.
1468  */
1469 int cmd_start_trace(struct ltt_session *session)
1470 {
1471         int ret;
1472         struct ltt_kernel_session *ksession;
1473         struct ltt_ust_session *usess;
1474
1475         assert(session);
1476
1477         /* Ease our life a bit ;) */
1478         ksession = session->kernel_session;
1479         usess = session->ust_session;
1480
1481         if (session->enabled) {
1482                 /* Already started. */
1483                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1484                 goto error;
1485         }
1486
1487         session->enabled = 1;
1488
1489         ret = setup_relayd(session);
1490         if (ret != LTTNG_OK) {
1491                 ERR("Error setting up relayd for session %s", session->name);
1492                 goto error;
1493         }
1494
1495         /* Kernel tracing */
1496         if (ksession != NULL) {
1497                 ret = start_kernel_session(ksession, kernel_tracer_fd);
1498                 if (ret != LTTNG_OK) {
1499                         goto error;
1500                 }
1501         }
1502
1503         /* Flag session that trace should start automatically */
1504         if (usess) {
1505                 usess->start_trace = 1;
1506
1507                 ret = ust_app_start_trace_all(usess);
1508                 if (ret < 0) {
1509                         ret = LTTNG_ERR_UST_START_FAIL;
1510                         goto error;
1511                 }
1512         }
1513
1514         session->started = 1;
1515
1516         ret = LTTNG_OK;
1517
1518 error:
1519         return ret;
1520 }
1521
1522 /*
1523  * Command LTTNG_STOP_TRACE processed by the client thread.
1524  */
1525 int cmd_stop_trace(struct ltt_session *session)
1526 {
1527         int ret;
1528         struct ltt_kernel_channel *kchan;
1529         struct ltt_kernel_session *ksession;
1530         struct ltt_ust_session *usess;
1531
1532         assert(session);
1533
1534         /* Short cut */
1535         ksession = session->kernel_session;
1536         usess = session->ust_session;
1537
1538         if (!session->enabled) {
1539                 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
1540                 goto error;
1541         }
1542
1543         session->enabled = 0;
1544
1545         /* Kernel tracer */
1546         if (ksession) {
1547                 DBG("Stop kernel tracing");
1548
1549                 /* Flush metadata if exist */
1550                 if (ksession->metadata_stream_fd >= 0) {
1551                         ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1552                         if (ret < 0) {
1553                                 ERR("Kernel metadata flush failed");
1554                         }
1555                 }
1556
1557                 /* Flush all buffers before stopping */
1558                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1559                         ret = kernel_flush_buffer(kchan);
1560                         if (ret < 0) {
1561                                 ERR("Kernel flush buffer error");
1562                         }
1563                 }
1564
1565                 ret = kernel_stop_session(ksession);
1566                 if (ret < 0) {
1567                         ret = LTTNG_ERR_KERN_STOP_FAIL;
1568                         goto error;
1569                 }
1570
1571                 kernel_wait_quiescent(kernel_tracer_fd);
1572
1573                 ksession->started = 0;
1574         }
1575
1576         if (usess) {
1577                 usess->start_trace = 0;
1578
1579                 ret = ust_app_stop_trace_all(usess);
1580                 if (ret < 0) {
1581                         ret = LTTNG_ERR_UST_STOP_FAIL;
1582                         goto error;
1583                 }
1584         }
1585
1586         session->started = 0;
1587
1588         ret = LTTNG_OK;
1589
1590 error:
1591         return ret;
1592 }
1593
1594 /*
1595  * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1596  */
1597 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1598                 size_t nb_uri, struct lttng_uri *uris)
1599 {
1600         int ret, i;
1601         struct ltt_kernel_session *ksess = session->kernel_session;
1602         struct ltt_ust_session *usess = session->ust_session;
1603         struct consumer_output *consumer = NULL;
1604
1605         assert(session);
1606         assert(uris);
1607         assert(nb_uri > 0);
1608
1609         /* Can't enable consumer after session started. */
1610         if (session->enabled) {
1611                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1612                 goto error;
1613         }
1614
1615         /*
1616          * This case switch makes sure the domain session has a temporary consumer
1617          * so the URL can be set.
1618          */
1619         switch (domain) {
1620         case 0:
1621                 /* Code flow error. A session MUST always have a consumer object */
1622                 assert(session->consumer);
1623                 /*
1624                  * The URL will be added to the tracing session consumer instead of a
1625                  * specific domain consumer.
1626                  */
1627                 consumer = session->consumer;
1628                 break;
1629         case LTTNG_DOMAIN_KERNEL:
1630                 /* Code flow error if we don't have a kernel session here. */
1631                 assert(ksess);
1632
1633                 /* Create consumer output if none exists */
1634                 consumer = ksess->tmp_consumer;
1635                 if (consumer == NULL) {
1636                         consumer = consumer_copy_output(ksess->consumer);
1637                         if (consumer == NULL) {
1638                                 ret = LTTNG_ERR_FATAL;
1639                                 goto error;
1640                         }
1641                         /* Trash the consumer subdir, we are about to set a new one. */
1642                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1643                         ksess->tmp_consumer = consumer;
1644                 }
1645
1646                 break;
1647         case LTTNG_DOMAIN_UST:
1648                 /* Code flow error if we don't have a kernel session here. */
1649                 assert(usess);
1650
1651                 /* Create consumer output if none exists */
1652                 consumer = usess->tmp_consumer;
1653                 if (consumer == NULL) {
1654                         consumer = consumer_copy_output(usess->consumer);
1655                         if (consumer == NULL) {
1656                                 ret = LTTNG_ERR_FATAL;
1657                                 goto error;
1658                         }
1659                         /* Trash the consumer subdir, we are about to set a new one. */
1660                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1661                         usess->tmp_consumer = consumer;
1662                 }
1663
1664                 break;
1665         }
1666
1667         for (i = 0; i < nb_uri; i++) {
1668                 struct consumer_socket *socket;
1669                 struct lttng_ht_iter iter;
1670
1671                 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1672                 if (ret < 0) {
1673                         goto error;
1674                 }
1675
1676                 /*
1677                  * Don't send relayd socket if URI is NOT remote or if the relayd
1678                  * socket for the session was already sent.
1679                  */
1680                 if (uris[i].dtype == LTTNG_DST_PATH ||
1681                                 (uris[i].stype == LTTNG_STREAM_CONTROL &&
1682                                 consumer->dst.net.control_sock_sent) ||
1683                                 (uris[i].stype == LTTNG_STREAM_DATA &&
1684                                 consumer->dst.net.data_sock_sent)) {
1685                         continue;
1686                 }
1687
1688                 /* Try to send relayd URI to the consumer if exist. */
1689                 rcu_read_lock();
1690                 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
1691                                 socket, node.node) {
1692
1693                         /* A socket in the HT should never have a negative fd */
1694                         assert(socket->fd >= 0);
1695
1696                         pthread_mutex_lock(socket->lock);
1697                         ret = send_consumer_relayd_socket(domain, session, &uris[i],
1698                                         consumer, socket->fd);
1699                         pthread_mutex_unlock(socket->lock);
1700                         if (ret != LTTNG_OK) {
1701                                 rcu_read_unlock();
1702                                 goto error;
1703                         }
1704                 }
1705                 rcu_read_unlock();
1706         }
1707
1708         /* All good! */
1709         ret = LTTNG_OK;
1710
1711 error:
1712         return ret;
1713 }
1714
1715 /*
1716  * Command LTTNG_CREATE_SESSION processed by the client thread.
1717  */
1718 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1719                 size_t nb_uri, lttng_sock_cred *creds)
1720 {
1721         int ret;
1722         char *path = NULL;
1723         struct ltt_session *session;
1724
1725         assert(name);
1726
1727         /*
1728          * Verify if the session already exist
1729          *
1730          * XXX: There is no need for the session lock list here since the caller
1731          * (process_client_msg) is holding it. We might want to change that so a
1732          * single command does not lock the entire session list.
1733          */
1734         session = session_find_by_name(name);
1735         if (session != NULL) {
1736                 ret = LTTNG_ERR_EXIST_SESS;
1737                 goto find_error;
1738         }
1739
1740         /* Create tracing session in the registry */
1741         ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1742                         LTTNG_SOCK_GET_GID_CRED(creds));
1743         if (ret != LTTNG_OK) {
1744                 goto session_error;
1745         }
1746
1747         /*
1748          * Get the newly created session pointer back
1749          *
1750          * XXX: There is no need for the session lock list here since the caller
1751          * (process_client_msg) is holding it. We might want to change that so a
1752          * single command does not lock the entire session list.
1753          */
1754         session = session_find_by_name(name);
1755         assert(session);
1756
1757         /* Create default consumer output for the session not yet created. */
1758         session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1759         if (session->consumer == NULL) {
1760                 ret = LTTNG_ERR_FATAL;
1761                 goto consumer_error;
1762         }
1763
1764         /*
1765          * This means that the lttng_create_session call was called with the _path_
1766          * argument set to NULL.
1767          */
1768         if (uris == NULL) {
1769                 /*
1770                  * At this point, we'll skip the consumer URI setup and create a
1771                  * session with a NULL path which will flag the session to NOT spawn a
1772                  * consumer.
1773                  */
1774                 DBG("Create session %s with NO uri, skipping consumer setup", name);
1775                 goto end;
1776         }
1777
1778         session->start_consumer = 1;
1779
1780         ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1781         if (ret != LTTNG_OK) {
1782                 goto consumer_error;
1783         }
1784
1785         session->consumer->enabled = 1;
1786
1787 end:
1788         return LTTNG_OK;
1789
1790 consumer_error:
1791         session_destroy(session);
1792 session_error:
1793 find_error:
1794         return ret;
1795 }
1796
1797 /*
1798  * Command LTTNG_DESTROY_SESSION processed by the client thread.
1799  */
1800 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1801 {
1802         int ret;
1803         struct ltt_ust_session *usess;
1804         struct ltt_kernel_session *ksess;
1805
1806         /* Safety net */
1807         assert(session);
1808
1809         usess = session->ust_session;
1810         ksess = session->kernel_session;
1811
1812         /* Clean kernel session teardown */
1813         kernel_destroy_session(ksess);
1814
1815         /* UST session teardown */
1816         if (usess) {
1817                 /* Close any relayd session */
1818                 consumer_output_send_destroy_relayd(usess->consumer);
1819
1820                 /* Destroy every UST application related to this session. */
1821                 ret = ust_app_destroy_trace_all(usess);
1822                 if (ret) {
1823                         ERR("Error in ust_app_destroy_trace_all");
1824                 }
1825
1826                 /* Clean up the rest. */
1827                 trace_ust_destroy_session(usess);
1828         }
1829
1830         /*
1831          * Must notify the kernel thread here to update it's poll set in order to
1832          * remove the channel(s)' fd just destroyed.
1833          */
1834         ret = notify_thread_pipe(wpipe);
1835         if (ret < 0) {
1836                 PERROR("write kernel poll pipe");
1837         }
1838
1839         ret = session_destroy(session);
1840
1841         return ret;
1842 }
1843
1844 /*
1845  * Command LTTNG_CALIBRATE processed by the client thread.
1846  */
1847 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1848 {
1849         int ret;
1850
1851         switch (domain) {
1852         case LTTNG_DOMAIN_KERNEL:
1853         {
1854                 struct lttng_kernel_calibrate kcalibrate;
1855
1856                 kcalibrate.type = calibrate->type;
1857                 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1858                 if (ret < 0) {
1859                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1860                         goto error;
1861                 }
1862                 break;
1863         }
1864         case LTTNG_DOMAIN_UST:
1865         {
1866                 struct lttng_ust_calibrate ucalibrate;
1867
1868                 ucalibrate.type = calibrate->type;
1869                 ret = ust_app_calibrate_glb(&ucalibrate);
1870                 if (ret < 0) {
1871                         ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
1872                         goto error;
1873                 }
1874                 break;
1875         }
1876         default:
1877                 ret = LTTNG_ERR_UND;
1878                 goto error;
1879         }
1880
1881         ret = LTTNG_OK;
1882
1883 error:
1884         return ret;
1885 }
1886
1887 /*
1888  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1889  */
1890 int cmd_register_consumer(struct ltt_session *session, int domain,
1891                 const char *sock_path, struct consumer_data *cdata)
1892 {
1893         int ret, sock;
1894         struct consumer_socket *socket;
1895
1896         assert(session);
1897         assert(cdata);
1898         assert(sock_path);
1899
1900         switch (domain) {
1901         case LTTNG_DOMAIN_KERNEL:
1902         {
1903                 struct ltt_kernel_session *ksess = session->kernel_session;
1904
1905                 assert(ksess);
1906
1907                 /* Can't register a consumer if there is already one */
1908                 if (ksess->consumer_fds_sent != 0) {
1909                         ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1910                         goto error;
1911                 }
1912
1913                 sock = lttcomm_connect_unix_sock(sock_path);
1914                 if (sock < 0) {
1915                         ret = LTTNG_ERR_CONNECT_FAIL;
1916                         goto error;
1917                 }
1918
1919                 socket = consumer_allocate_socket(sock);
1920                 if (socket == NULL) {
1921                         ret = LTTNG_ERR_FATAL;
1922                         close(sock);
1923                         goto error;
1924                 }
1925
1926                 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1927                 if (socket->lock == NULL) {
1928                         PERROR("zmalloc pthread mutex");
1929                         ret = LTTNG_ERR_FATAL;
1930                         goto error;
1931                 }
1932                 pthread_mutex_init(socket->lock, NULL);
1933                 socket->registered = 1;
1934
1935                 rcu_read_lock();
1936                 consumer_add_socket(socket, ksess->consumer);
1937                 rcu_read_unlock();
1938
1939                 pthread_mutex_lock(&cdata->pid_mutex);
1940                 cdata->pid = -1;
1941                 pthread_mutex_unlock(&cdata->pid_mutex);
1942
1943                 break;
1944         }
1945         default:
1946                 /* TODO: Userspace tracing */
1947                 ret = LTTNG_ERR_UND;
1948                 goto error;
1949         }
1950
1951         ret = LTTNG_OK;
1952
1953 error:
1954         return ret;
1955 }
1956
1957 /*
1958  * Command LTTNG_LIST_DOMAINS processed by the client thread.
1959  */
1960 ssize_t cmd_list_domains(struct ltt_session *session,
1961                 struct lttng_domain **domains)
1962 {
1963         int ret, index = 0;
1964         ssize_t nb_dom = 0;
1965
1966         if (session->kernel_session != NULL) {
1967                 DBG3("Listing domains found kernel domain");
1968                 nb_dom++;
1969         }
1970
1971         if (session->ust_session != NULL) {
1972                 DBG3("Listing domains found UST global domain");
1973                 nb_dom++;
1974         }
1975
1976         *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1977         if (*domains == NULL) {
1978                 ret = LTTNG_ERR_FATAL;
1979                 goto error;
1980         }
1981
1982         if (session->kernel_session != NULL) {
1983                 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1984                 index++;
1985         }
1986
1987         if (session->ust_session != NULL) {
1988                 (*domains)[index].type = LTTNG_DOMAIN_UST;
1989                 index++;
1990         }
1991
1992         return nb_dom;
1993
1994 error:
1995         /* Return negative value to differentiate return code */
1996         return -ret;
1997 }
1998
1999
2000 /*
2001  * Command LTTNG_LIST_CHANNELS processed by the client thread.
2002  */
2003 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
2004                 struct lttng_channel **channels)
2005 {
2006         int ret;
2007         ssize_t nb_chan = 0;
2008
2009         switch (domain) {
2010         case LTTNG_DOMAIN_KERNEL:
2011                 if (session->kernel_session != NULL) {
2012                         nb_chan = session->kernel_session->channel_count;
2013                 }
2014                 DBG3("Number of kernel channels %zd", nb_chan);
2015                 if (nb_chan <= 0) {
2016                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
2017                 }
2018                 break;
2019         case LTTNG_DOMAIN_UST:
2020                 if (session->ust_session != NULL) {
2021                         nb_chan = lttng_ht_get_count(
2022                                         session->ust_session->domain_global.channels);
2023                 }
2024                 DBG3("Number of UST global channels %zd", nb_chan);
2025                 if (nb_chan <= 0) {
2026                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2027                 }
2028                 break;
2029         default:
2030                 *channels = NULL;
2031                 ret = LTTNG_ERR_UND;
2032                 goto error;
2033         }
2034
2035         if (nb_chan > 0) {
2036                 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2037                 if (*channels == NULL) {
2038                         ret = LTTNG_ERR_FATAL;
2039                         goto error;
2040                 }
2041
2042                 list_lttng_channels(domain, session, *channels);
2043         } else {
2044                 *channels = NULL;
2045                 /* Ret value was set in the domain switch case */
2046                 goto error;
2047         }
2048
2049         return nb_chan;
2050
2051 error:
2052         /* Return negative value to differentiate return code */
2053         return -ret;
2054 }
2055
2056 /*
2057  * Command LTTNG_LIST_EVENTS processed by the client thread.
2058  */
2059 ssize_t cmd_list_events(int domain, struct ltt_session *session,
2060                 char *channel_name, struct lttng_event **events)
2061 {
2062         int ret = 0;
2063         ssize_t nb_event = 0;
2064
2065         switch (domain) {
2066         case LTTNG_DOMAIN_KERNEL:
2067                 if (session->kernel_session != NULL) {
2068                         nb_event = list_lttng_kernel_events(channel_name,
2069                                         session->kernel_session, events);
2070                 }
2071                 break;
2072         case LTTNG_DOMAIN_UST:
2073         {
2074                 if (session->ust_session != NULL) {
2075                         nb_event = list_lttng_ust_global_events(channel_name,
2076                                         &session->ust_session->domain_global, events);
2077                 }
2078                 break;
2079         }
2080         default:
2081                 ret = LTTNG_ERR_UND;
2082                 goto error;
2083         }
2084
2085         return nb_event;
2086
2087 error:
2088         /* Return negative value to differentiate return code */
2089         return -ret;
2090 }
2091
2092 /*
2093  * Using the session list, filled a lttng_session array to send back to the
2094  * client for session listing.
2095  *
2096  * The session list lock MUST be acquired before calling this function. Use
2097  * session_lock_list() and session_unlock_list().
2098  */
2099 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2100                 gid_t gid)
2101 {
2102         int ret;
2103         unsigned int i = 0;
2104         struct ltt_session *session;
2105         struct ltt_session_list *list = session_get_list();
2106
2107         DBG("Getting all available session for UID %d GID %d",
2108                         uid, gid);
2109         /*
2110          * Iterate over session list and append data after the control struct in
2111          * the buffer.
2112          */
2113         cds_list_for_each_entry(session, &list->head, list) {
2114                 /*
2115                  * Only list the sessions the user can control.
2116                  */
2117                 if (!session_access_ok(session, uid, gid)) {
2118                         continue;
2119                 }
2120
2121                 struct ltt_kernel_session *ksess = session->kernel_session;
2122                 struct ltt_ust_session *usess = session->ust_session;
2123
2124                 if (session->consumer->type == CONSUMER_DST_NET ||
2125                                 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2126                                 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2127                         ret = build_network_session_path(sessions[i].path,
2128                                         sizeof(session[i].path), session);
2129                 } else {
2130                         ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2131                                         session->consumer->dst.trace_path);
2132                 }
2133                 if (ret < 0) {
2134                         PERROR("snprintf session path");
2135                         continue;
2136                 }
2137
2138                 strncpy(sessions[i].name, session->name, NAME_MAX);
2139                 sessions[i].name[NAME_MAX - 1] = '\0';
2140                 sessions[i].enabled = session->enabled;
2141                 i++;
2142         }
2143 }
2144
2145 /*
2146  * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2147  */
2148 int cmd_disable_consumer(int domain, struct ltt_session *session)
2149 {
2150         int ret;
2151         struct ltt_kernel_session *ksess = session->kernel_session;
2152         struct ltt_ust_session *usess = session->ust_session;
2153         struct consumer_output *consumer;
2154
2155         assert(session);
2156
2157         if (session->enabled) {
2158                 /* Can't disable consumer on an already started session */
2159                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2160                 goto error;
2161         }
2162
2163         if (!session->start_consumer) {
2164                 ret = LTTNG_ERR_NO_CONSUMER;
2165                 goto error;
2166         }
2167
2168         switch (domain) {
2169         case 0:
2170                 DBG("Disable tracing session %s consumer", session->name);
2171                 consumer = session->consumer;
2172                 break;
2173         case LTTNG_DOMAIN_KERNEL:
2174                 /* Code flow error if we don't have a kernel session here. */
2175                 assert(ksess);
2176
2177                 DBG("Disabling kernel consumer");
2178                 consumer = ksess->consumer;
2179
2180                 break;
2181         case LTTNG_DOMAIN_UST:
2182                 /* Code flow error if we don't have a UST session here. */
2183                 assert(usess);
2184
2185                 DBG("Disabling UST consumer");
2186                 consumer = usess->consumer;
2187
2188                 break;
2189         default:
2190                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
2191                 goto error;
2192         }
2193
2194         if (consumer) {
2195                 consumer->enabled = 0;
2196                 /* Success at this point */
2197                 ret = LTTNG_OK;
2198         } else {
2199                 ret = LTTNG_ERR_NO_CONSUMER;
2200         }
2201
2202 error:
2203         return ret;
2204 }
2205
2206 /*
2207  * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2208  */
2209 int cmd_enable_consumer(int domain, struct ltt_session *session)
2210 {
2211         int ret;
2212         struct ltt_kernel_session *ksess = session->kernel_session;
2213         struct ltt_ust_session *usess = session->ust_session;
2214         struct consumer_output *consumer = NULL;
2215
2216         assert(session);
2217
2218         /* Can't enable consumer after session started. */
2219         if (session->enabled) {
2220                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2221                 goto error;
2222         }
2223
2224         switch (domain) {
2225         case 0:
2226                 assert(session->consumer);
2227                 consumer = session->consumer;
2228                 break;
2229         case LTTNG_DOMAIN_KERNEL:
2230                 /* Code flow error if we don't have a kernel session here. */
2231                 assert(ksess);
2232
2233                 /*
2234                  * Check if we have already sent fds to the consumer. In that case,
2235                  * the enable-consumer command can't be used because a start trace
2236                  * had previously occured.
2237                  */
2238                 if (ksess->consumer_fds_sent) {
2239                         ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2240                         goto error;
2241                 }
2242
2243                 consumer = ksess->tmp_consumer;
2244                 if (consumer == NULL) {
2245                         ret = LTTNG_OK;
2246                         /* No temp. consumer output exists. Using the current one. */
2247                         DBG3("No temporary consumer. Using default");
2248                         consumer = ksess->consumer;
2249                         goto error;
2250                 }
2251
2252                 switch (consumer->type) {
2253                 case CONSUMER_DST_LOCAL:
2254                         DBG2("Consumer output is local. Creating directory(ies)");
2255
2256                         /* Create directory(ies) */
2257                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2258                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2259                         if (ret < 0) {
2260                                 if (ret != -EEXIST) {
2261                                         ERR("Trace directory creation error");
2262                                         ret = LTTNG_ERR_FATAL;
2263                                         goto error;
2264                                 }
2265                         }
2266                         break;
2267                 case CONSUMER_DST_NET:
2268                         DBG2("Consumer output is network. Validating URIs");
2269                         /* Validate if we have both control and data path set. */
2270                         if (!consumer->dst.net.control_isset) {
2271                                 ret = LTTNG_ERR_URL_CTRL_MISS;
2272                                 goto error;
2273                         }
2274
2275                         if (!consumer->dst.net.data_isset) {
2276                                 ret = LTTNG_ERR_URL_DATA_MISS;
2277                                 goto error;
2278                         }
2279
2280                         /* Check established network session state */
2281                         if (session->net_handle == 0) {
2282                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2283                                 ERR("Session network handle is not set on enable-consumer");
2284                                 goto error;
2285                         }
2286
2287                         break;
2288                 }
2289
2290                 /*
2291                  * @session-lock
2292                  * This is race free for now since the session lock is acquired before
2293                  * ending up in this function. No other threads can access this kernel
2294                  * session without this lock hence freeing the consumer output object
2295                  * is valid.
2296                  */
2297                 rcu_read_lock();
2298                 /* Destroy current consumer. We are about to replace it */
2299                 consumer_destroy_output(ksess->consumer);
2300                 rcu_read_unlock();
2301                 ksess->consumer = consumer;
2302                 ksess->tmp_consumer = NULL;
2303
2304                 break;
2305         case LTTNG_DOMAIN_UST:
2306                 /* Code flow error if we don't have a UST session here. */
2307                 assert(usess);
2308
2309                 /*
2310                  * Check if we have already sent fds to the consumer. In that case,
2311                  * the enable-consumer command can't be used because a start trace
2312                  * had previously occured.
2313                  */
2314                 if (usess->start_trace) {
2315                         ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2316                         goto error;
2317                 }
2318
2319                 consumer = usess->tmp_consumer;
2320                 if (consumer == NULL) {
2321                         ret = LTTNG_OK;
2322                         /* No temp. consumer output exists. Using the current one. */
2323                         DBG3("No temporary consumer. Using default");
2324                         consumer = usess->consumer;
2325                         goto error;
2326                 }
2327
2328                 switch (consumer->type) {
2329                 case CONSUMER_DST_LOCAL:
2330                         DBG2("Consumer output is local. Creating directory(ies)");
2331
2332                         /* Create directory(ies) */
2333                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2334                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2335                         if (ret < 0) {
2336                                 if (ret != -EEXIST) {
2337                                         ERR("Trace directory creation error");
2338                                         ret = LTTNG_ERR_FATAL;
2339                                         goto error;
2340                                 }
2341                         }
2342                         break;
2343                 case CONSUMER_DST_NET:
2344                         DBG2("Consumer output is network. Validating URIs");
2345                         /* Validate if we have both control and data path set. */
2346                         if (!consumer->dst.net.control_isset) {
2347                                 ret = LTTNG_ERR_URL_CTRL_MISS;
2348                                 goto error;
2349                         }
2350
2351                         if (!consumer->dst.net.data_isset) {
2352                                 ret = LTTNG_ERR_URL_DATA_MISS;
2353                                 goto error;
2354                         }
2355
2356                         /* Check established network session state */
2357                         if (session->net_handle == 0) {
2358                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2359                                 DBG2("Session network handle is not set on enable-consumer");
2360                                 goto error;
2361                         }
2362
2363                         if (consumer->net_seq_index == -1) {
2364                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2365                                 DBG2("Network index is not set on the consumer");
2366                                 goto error;
2367                         }
2368
2369                         break;
2370                 }
2371
2372                 /*
2373                  * @session-lock
2374                  * This is race free for now since the session lock is acquired before
2375                  * ending up in this function. No other threads can access this kernel
2376                  * session without this lock hence freeing the consumer output object
2377                  * is valid.
2378                  */
2379                 rcu_read_lock();
2380                 /* Destroy current consumer. We are about to replace it */
2381                 consumer_destroy_output(usess->consumer);
2382                 rcu_read_unlock();
2383                 usess->consumer = consumer;
2384                 usess->tmp_consumer = NULL;
2385
2386                 break;
2387         }
2388
2389         session->start_consumer = 1;
2390
2391         /* Enable it */
2392         if (consumer) {
2393                 consumer->enabled = 1;
2394                 /* Success at this point */
2395                 ret = LTTNG_OK;
2396         } else {
2397                 /* Should not really happend... */
2398                 ret = LTTNG_ERR_NO_CONSUMER;
2399         }
2400
2401 error:
2402         return ret;
2403 }
2404
2405 /*
2406  * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
2407  * ready for trace analysis (or anykind of reader) or else 1 for pending data.
2408  */
2409 int cmd_data_pending(struct ltt_session *session)
2410 {
2411         int ret;
2412         struct ltt_kernel_session *ksess = session->kernel_session;
2413         struct ltt_ust_session *usess = session->ust_session;
2414
2415         assert(session);
2416
2417         /* Session MUST be stopped to ask for data availability. */
2418         if (session->enabled) {
2419                 ret = LTTNG_ERR_SESSION_STARTED;
2420                 goto error;
2421         }
2422
2423         if (ksess && ksess->consumer) {
2424                 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
2425                 if (ret == 1) {
2426                         /* Data is still being extracted for the kernel. */
2427                         goto error;
2428                 }
2429         }
2430
2431         if (usess && usess->consumer) {
2432                 ret = consumer_is_data_pending(usess->id, usess->consumer);
2433                 if (ret == 1) {
2434                         /* Data is still being extracted for the kernel. */
2435                         goto error;
2436                 }
2437         }
2438
2439         /* Data is ready to be read by a viewer */
2440         ret = 0;
2441
2442 error:
2443         return ret;
2444 }
2445
2446 /*
2447  * Init command subsystem.
2448  */
2449 void cmd_init(void)
2450 {
2451         /*
2452          * Set network sequence index to 1 for streams to match a relayd socket on
2453          * the consumer side.
2454          */
2455         uatomic_set(&relayd_net_seq_idx, 1);
2456
2457         DBG("Command subsystem initialized");
2458 }