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, 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                 struct consumer_socket *consumer_sock)
 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_sock, sock,
 561                         consumer, relayd_uri->stype, session->id);
 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,
 597                 struct consumer_socket *sock)
 598 {
 599         int ret = LTTNG_OK;
 600
 601         assert(session);
 602         assert(consumer);
 603
 604         /* Sending control relayd socket. */
 605         if (!consumer->dst.net.control_sock_sent) {
 606                 ret = send_consumer_relayd_socket(domain, session,
 607                                 &consumer->dst.net.control, consumer, sock);
 608                 if (ret != LTTNG_OK) {
 609                         goto error;
 610                 }
 611         }
 612
 613         /* Sending data relayd socket. */
 614         if (!consumer->dst.net.data_sock_sent) {
 615                 ret = send_consumer_relayd_socket(domain, session,
 616                                 &consumer->dst.net.data, consumer, sock);
 617                 if (ret != LTTNG_OK) {
 618                         goto error;
 619                 }
 620         }
 621
 622 error:
 623         return ret;
 624 }
 625
 626 /*
 627  * Setup relayd connections for a tracing session. First creates the socket to
 628  * the relayd and send them to the right domain consumer. Consumer type MUST be
 629  * network.
 630  */
 631 static int setup_relayd(struct ltt_session *session)
 632 {
 633         int ret = LTTNG_OK;
 634         struct ltt_ust_session *usess;
 635         struct ltt_kernel_session *ksess;
 636         struct consumer_socket *socket;
 637         struct lttng_ht_iter iter;
 638
 639         assert(session);
 640
 641         usess = session->ust_session;
 642         ksess = session->kernel_session;
 643
 644         DBG2("Setting relayd for session %s", session->name);
 645
 646         if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 647                         && usess->consumer->enabled) {
 648                 /* For each consumer socket, send relayd sockets */
 649                 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
 650                                 socket, node.node) {
 651                         /* Code flow error */
 652                         assert(socket->fd >= 0);
 653
 654                         pthread_mutex_lock(socket->lock);
 655                         ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
 656                                         usess->consumer, socket);
 657                         pthread_mutex_unlock(socket->lock);
 658                         if (ret != LTTNG_OK) {
 659                                 goto error;
 660                         }
 661                 }
 662         }
 663
 664         if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
 665                         && ksess->consumer->enabled) {
 666                 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
 667                                 socket, node.node) {
 668                         /* Code flow error */
 669                         assert(socket->fd >= 0);
 670
 671                         pthread_mutex_lock(socket->lock);
 672                         ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
 673                                         ksess->consumer, socket);
 674                         pthread_mutex_unlock(socket->lock);
 675                         if (ret != LTTNG_OK) {
 676                                 goto error;
 677                         }
 678                 }
 679         }
 680
 681 error:
 682         return ret;
 683 }
 684
 685 /*
 686  * Start a kernel session by opening all necessary streams.
 687  */
 688 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
 689 {
 690         int ret;
 691         struct ltt_kernel_channel *kchan;
 692
 693         /* Open kernel metadata */
 694         if (ksess->metadata == NULL) {
 695                 ret = kernel_open_metadata(ksess);
 696                 if (ret < 0) {
 697                         ret = LTTNG_ERR_KERN_META_FAIL;
 698                         goto error;
 699                 }
 700         }
 701
 702         /* Open kernel metadata stream */
 703         if (ksess->metadata_stream_fd < 0) {
 704                 ret = kernel_open_metadata_stream(ksess);
 705                 if (ret < 0) {
 706                         ERR("Kernel create metadata stream failed");
 707                         ret = LTTNG_ERR_KERN_STREAM_FAIL;
 708                         goto error;
 709                 }
 710         }
 711
 712         /* For each channel */
 713         cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
 714                 if (kchan->stream_count == 0) {
 715                         ret = kernel_open_channel_stream(kchan);
 716                         if (ret < 0) {
 717                                 ret = LTTNG_ERR_KERN_STREAM_FAIL;
 718                                 goto error;
 719                         }
 720                         /* Update the stream global counter */
 721                         ksess->stream_count_global += ret;
 722                 }
 723         }
 724
 725         /* Setup kernel consumer socket and send fds to it */
 726         ret = init_kernel_tracing(ksess);
 727         if (ret < 0) {
 728                 ret = LTTNG_ERR_KERN_START_FAIL;
 729                 goto error;
 730         }
 731
 732         /* This start the kernel tracing */
 733         ret = kernel_start_session(ksess);
 734         if (ret < 0) {
 735                 ret = LTTNG_ERR_KERN_START_FAIL;
 736                 goto error;
 737         }
 738
 739         /* Quiescent wait after starting trace */
 740         kernel_wait_quiescent(kernel_tracer_fd);
 741
 742         ksess->started = 1;
 743
 744         ret = LTTNG_OK;
 745
 746 error:
 747         return ret;
 748 }
 749
 750 /*
 751  * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
 752  */
 753 int cmd_disable_channel(struct ltt_session *session, int domain,
 754                 char *channel_name)
 755 {
 756         int ret;
 757         struct ltt_ust_session *usess;
 758
 759         usess = session->ust_session;
 760
 761         switch (domain) {
 762         case LTTNG_DOMAIN_KERNEL:
 763         {
 764                 ret = channel_kernel_disable(session->kernel_session,
 765                                 channel_name);
 766                 if (ret != LTTNG_OK) {
 767                         goto error;
 768                 }
 769
 770                 kernel_wait_quiescent(kernel_tracer_fd);
 771                 break;
 772         }
 773         case LTTNG_DOMAIN_UST:
 774         {
 775                 struct ltt_ust_channel *uchan;
 776                 struct lttng_ht *chan_ht;
 777
 778                 chan_ht = usess->domain_global.channels;
 779
 780                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 781                 if (uchan == NULL) {
 782                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 783                         goto error;
 784                 }
 785
 786                 ret = channel_ust_disable(usess, domain, uchan);
 787                 if (ret != LTTNG_OK) {
 788                         goto error;
 789                 }
 790                 break;
 791         }
 792 #if 0
 793         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 794         case LTTNG_DOMAIN_UST_EXEC_NAME:
 795         case LTTNG_DOMAIN_UST_PID:
 796 #endif
 797         default:
 798                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 799                 goto error;
 800         }
 801
 802         ret = LTTNG_OK;
 803
 804 error:
 805         return ret;
 806 }
 807
 808 /*
 809  * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
 810  *
 811  * The wpipe arguments is used as a notifier for the kernel thread.
 812  */
 813 int cmd_enable_channel(struct ltt_session *session,
 814                 int domain, struct lttng_channel *attr, int wpipe)
 815 {
 816         int ret;
 817         struct ltt_ust_session *usess = session->ust_session;
 818         struct lttng_ht *chan_ht;
 819
 820         assert(session);
 821         assert(attr);
 822
 823         DBG("Enabling channel %s for session %s", attr->name, session->name);
 824
 825         switch (domain) {
 826         case LTTNG_DOMAIN_KERNEL:
 827         {
 828                 struct ltt_kernel_channel *kchan;
 829
 830                 kchan = trace_kernel_get_channel_by_name(attr->name,
 831                                 session->kernel_session);
 832                 if (kchan == NULL) {
 833                         ret = channel_kernel_create(session->kernel_session, attr, wpipe);
 834                 } else {
 835                         ret = channel_kernel_enable(session->kernel_session, kchan);
 836                 }
 837
 838                 if (ret != LTTNG_OK) {
 839                         goto error;
 840                 }
 841
 842                 kernel_wait_quiescent(kernel_tracer_fd);
 843
 844                 /*
 845                  * If the session was previously started, start as well this newly
 846                  * created kernel session so the events/channels enabled *after* the
 847                  * start actually work.
 848                  */
 849                 if (session->started && !session->kernel_session->started) {
 850                         ret = start_kernel_session(session->kernel_session, wpipe);
 851                         if (ret != LTTNG_OK) {
 852                                 goto error;
 853                         }
 854                 }
 855                 break;
 856         }
 857         case LTTNG_DOMAIN_UST:
 858         {
 859                 struct ltt_ust_channel *uchan;
 860
 861                 chan_ht = usess->domain_global.channels;
 862
 863                 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
 864                 if (uchan == NULL) {
 865                         ret = channel_ust_create(usess, domain, attr);
 866                 } else {
 867                         ret = channel_ust_enable(usess, domain, uchan);
 868                 }
 869
 870                 /* Start the UST session if the session was already started. */
 871                 if (session->started && !usess->start_trace) {
 872                         ret = ust_app_start_trace_all(usess);
 873                         if (ret < 0) {
 874                                 ret = LTTNG_ERR_UST_START_FAIL;
 875                                 goto error;
 876                         }
 877                         ret = LTTNG_OK;
 878                         usess->start_trace = 1;
 879                 }
 880                 break;
 881         }
 882 #if 0
 883         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 884         case LTTNG_DOMAIN_UST_EXEC_NAME:
 885         case LTTNG_DOMAIN_UST_PID:
 886 #endif
 887         default:
 888                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 889                 goto error;
 890         }
 891
 892 error:
 893         return ret;
 894 }
 895
 896
 897 /*
 898  * Command LTTNG_DISABLE_EVENT processed by the client thread.
 899  */
 900 int cmd_disable_event(struct ltt_session *session, int domain,
 901                 char *channel_name, char *event_name)
 902 {
 903         int ret;
 904
 905         switch (domain) {
 906         case LTTNG_DOMAIN_KERNEL:
 907         {
 908                 struct ltt_kernel_channel *kchan;
 909                 struct ltt_kernel_session *ksess;
 910
 911                 ksess = session->kernel_session;
 912
 913                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 914                 if (kchan == NULL) {
 915                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 916                         goto error;
 917                 }
 918
 919                 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
 920                 if (ret != LTTNG_OK) {
 921                         goto error;
 922                 }
 923
 924                 kernel_wait_quiescent(kernel_tracer_fd);
 925                 break;
 926         }
 927         case LTTNG_DOMAIN_UST:
 928         {
 929                 struct ltt_ust_channel *uchan;
 930                 struct ltt_ust_session *usess;
 931
 932                 usess = session->ust_session;
 933
 934                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 935                                 channel_name);
 936                 if (uchan == NULL) {
 937                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 938                         goto error;
 939                 }
 940
 941                 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
 942                 if (ret != LTTNG_OK) {
 943                         goto error;
 944                 }
 945
 946                 DBG3("Disable UST event %s in channel %s completed", event_name,
 947                                 channel_name);
 948                 break;
 949         }
 950 #if 0
 951         case LTTNG_DOMAIN_UST_EXEC_NAME:
 952         case LTTNG_DOMAIN_UST_PID:
 953         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 954 #endif
 955         default:
 956                 ret = LTTNG_ERR_UND;
 957                 goto error;
 958         }
 959
 960         ret = LTTNG_OK;
 961
 962 error:
 963         return ret;
 964 }
 965
 966 /*
 967  * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
 968  */
 969 int cmd_disable_event_all(struct ltt_session *session, int domain,
 970                 char *channel_name)
 971 {
 972         int ret;
 973
 974         switch (domain) {
 975         case LTTNG_DOMAIN_KERNEL:
 976         {
 977                 struct ltt_kernel_session *ksess;
 978                 struct ltt_kernel_channel *kchan;
 979
 980                 ksess = session->kernel_session;
 981
 982                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 983                 if (kchan == NULL) {
 984                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 985                         goto error;
 986                 }
 987
 988                 ret = event_kernel_disable_all(ksess, kchan);
 989                 if (ret != LTTNG_OK) {
 990                         goto error;
 991                 }
 992
 993                 kernel_wait_quiescent(kernel_tracer_fd);
 994                 break;
 995         }
 996         case LTTNG_DOMAIN_UST:
 997         {
 998                 struct ltt_ust_session *usess;
 999                 struct ltt_ust_channel *uchan;
1000
1001                 usess = session->ust_session;
1002
1003                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1004                                 channel_name);
1005                 if (uchan == NULL) {
1006                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1007                         goto error;
1008                 }
1009
1010                 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
1011                 if (ret != 0) {
1012                         goto error;
1013                 }
1014
1015                 DBG3("Disable all UST events in channel %s completed", channel_name);
1016
1017                 break;
1018         }
1019 #if 0
1020         case LTTNG_DOMAIN_UST_EXEC_NAME:
1021         case LTTNG_DOMAIN_UST_PID:
1022         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1023 #endif
1024         default:
1025                 ret = LTTNG_ERR_UND;
1026                 goto error;
1027         }
1028
1029         ret = LTTNG_OK;
1030
1031 error:
1032         return ret;
1033 }
1034
1035 /*
1036  * Command LTTNG_ADD_CONTEXT processed by the client thread.
1037  */
1038 int cmd_add_context(struct ltt_session *session, int domain,
1039                 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1040 {
1041         int ret;
1042
1043         switch (domain) {
1044         case LTTNG_DOMAIN_KERNEL:
1045                 assert(session->kernel_session);
1046
1047                 if (session->kernel_session->channel_count == 0) {
1048                         /* Create default channel */
1049                         ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1050                         if (ret != LTTNG_OK) {
1051                                 goto error;
1052                         }
1053                 }
1054
1055                 /* Add kernel context to kernel tracer */
1056                 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1057                 if (ret != LTTNG_OK) {
1058                         goto error;
1059                 }
1060                 break;
1061         case LTTNG_DOMAIN_UST:
1062         {
1063                 struct ltt_ust_session *usess = session->ust_session;
1064                 assert(usess);
1065
1066                 unsigned int chan_count =
1067                         lttng_ht_get_count(usess->domain_global.channels);
1068                 if (chan_count == 0) {
1069                         struct lttng_channel *attr;
1070                         /* Create default channel */
1071                         attr = channel_new_default_attr(domain);
1072                         if (attr == NULL) {
1073                                 ret = LTTNG_ERR_FATAL;
1074                                 goto error;
1075                         }
1076
1077                         ret = channel_ust_create(usess, domain, attr);
1078                         if (ret != LTTNG_OK) {
1079                                 free(attr);
1080                                 goto error;
1081                         }
1082                         free(attr);
1083                 }
1084
1085                 ret = context_ust_add(usess, domain, ctx, channel_name);
1086                 if (ret != LTTNG_OK) {
1087                         goto error;
1088                 }
1089                 break;
1090         }
1091 #if 0
1092         case LTTNG_DOMAIN_UST_EXEC_NAME:
1093         case LTTNG_DOMAIN_UST_PID:
1094         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1095 #endif
1096         default:
1097                 ret = LTTNG_ERR_UND;
1098                 goto error;
1099         }
1100
1101         ret = LTTNG_OK;
1102
1103 error:
1104         return ret;
1105 }
1106
1107 /*
1108  * Command LTTNG_ENABLE_EVENT processed by the client thread.
1109  */
1110 int cmd_enable_event(struct ltt_session *session, int domain,
1111                 char *channel_name, struct lttng_event *event,
1112                 struct lttng_filter_bytecode *filter, int wpipe)
1113 {
1114         int ret, channel_created = 0;
1115         struct lttng_channel *attr;
1116
1117         assert(session);
1118         assert(event);
1119         assert(channel_name);
1120
1121         switch (domain) {
1122         case LTTNG_DOMAIN_KERNEL:
1123         {
1124                 struct ltt_kernel_channel *kchan;
1125
1126                 kchan = trace_kernel_get_channel_by_name(channel_name,
1127                                 session->kernel_session);
1128                 if (kchan == NULL) {
1129                         attr = channel_new_default_attr(domain);
1130                         if (attr == NULL) {
1131                                 ret = LTTNG_ERR_FATAL;
1132                                 goto error;
1133                         }
1134                         strncpy(attr->name, channel_name, sizeof(attr->name));
1135
1136                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1137                         if (ret != LTTNG_OK) {
1138                                 free(attr);
1139                                 goto error;
1140                         }
1141                         free(attr);
1142
1143                         channel_created = 1;
1144                 }
1145
1146                 /* Get the newly created kernel channel pointer */
1147                 kchan = trace_kernel_get_channel_by_name(channel_name,
1148                                 session->kernel_session);
1149                 if (kchan == NULL) {
1150                         /* This sould not happen... */
1151                         ret = LTTNG_ERR_FATAL;
1152                         goto error;
1153                 }
1154
1155                 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
1156                                 event);
1157                 if (ret != LTTNG_OK) {
1158                         if (channel_created) {
1159                                 /* Let's not leak a useless channel. */
1160                                 kernel_destroy_channel(kchan);
1161                         }
1162                         goto error;
1163                 }
1164
1165                 kernel_wait_quiescent(kernel_tracer_fd);
1166                 break;
1167         }
1168         case LTTNG_DOMAIN_UST:
1169         {
1170                 struct ltt_ust_channel *uchan;
1171                 struct ltt_ust_session *usess = session->ust_session;
1172
1173                 assert(usess);
1174
1175                 /* Get channel from global UST domain */
1176                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1177                                 channel_name);
1178                 if (uchan == NULL) {
1179                         /* Create default channel */
1180                         attr = channel_new_default_attr(domain);
1181                         if (attr == NULL) {
1182                                 ret = LTTNG_ERR_FATAL;
1183                                 goto error;
1184                         }
1185                         strncpy(attr->name, channel_name, sizeof(attr->name));
1186
1187                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1188                         if (ret != LTTNG_OK) {
1189                                 free(attr);
1190                                 goto error;
1191                         }
1192                         free(attr);
1193
1194                         /* Get the newly created channel reference back */
1195                         uchan = trace_ust_find_channel_by_name(
1196                                         usess->domain_global.channels, channel_name);
1197                         assert(uchan);
1198                 }
1199
1200                 /* At this point, the session and channel exist on the tracer */
1201                 ret = event_ust_enable_tracepoint(usess, domain, uchan, event, filter);
1202                 if (ret != LTTNG_OK) {
1203                         goto error;
1204                 }
1205                 break;
1206         }
1207 #if 0
1208         case LTTNG_DOMAIN_UST_EXEC_NAME:
1209         case LTTNG_DOMAIN_UST_PID:
1210         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1211 #endif
1212         default:
1213                 ret = LTTNG_ERR_UND;
1214                 goto error;
1215         }
1216
1217         ret = LTTNG_OK;
1218
1219 error:
1220         return ret;
1221 }
1222
1223 /*
1224  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1225  */
1226 int cmd_enable_event_all(struct ltt_session *session, int domain,
1227                 char *channel_name, int event_type,
1228                 struct lttng_filter_bytecode *filter, int wpipe)
1229 {
1230         int ret;
1231         struct lttng_channel *attr;
1232
1233         assert(session);
1234         assert(channel_name);
1235
1236         switch (domain) {
1237         case LTTNG_DOMAIN_KERNEL:
1238         {
1239                 struct ltt_kernel_channel *kchan;
1240
1241                 assert(session->kernel_session);
1242
1243                 kchan = trace_kernel_get_channel_by_name(channel_name,
1244                                 session->kernel_session);
1245                 if (kchan == NULL) {
1246                         /* Create default channel */
1247                         attr = channel_new_default_attr(domain);
1248                         if (attr == NULL) {
1249                                 ret = LTTNG_ERR_FATAL;
1250                                 goto error;
1251                         }
1252                         strncpy(attr->name, channel_name, sizeof(attr->name));
1253
1254                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1255                         if (ret != LTTNG_OK) {
1256                                 free(attr);
1257                                 goto error;
1258                         }
1259                         free(attr);
1260
1261                         /* Get the newly created kernel channel pointer */
1262                         kchan = trace_kernel_get_channel_by_name(channel_name,
1263                                         session->kernel_session);
1264                         assert(kchan);
1265                 }
1266
1267                 switch (event_type) {
1268                 case LTTNG_EVENT_SYSCALL:
1269                         ret = event_kernel_enable_all_syscalls(session->kernel_session,
1270                                         kchan, kernel_tracer_fd);
1271                         break;
1272                 case LTTNG_EVENT_TRACEPOINT:
1273                         /*
1274                          * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1275                          * events already registered to the channel.
1276                          */
1277                         ret = event_kernel_enable_all_tracepoints(session->kernel_session,
1278                                         kchan, kernel_tracer_fd);
1279                         break;
1280                 case LTTNG_EVENT_ALL:
1281                         /* Enable syscalls and tracepoints */
1282                         ret = event_kernel_enable_all(session->kernel_session,
1283                                         kchan, kernel_tracer_fd);
1284                         break;
1285                 default:
1286                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1287                         goto error;
1288                 }
1289
1290                 /* Manage return value */
1291                 if (ret != LTTNG_OK) {
1292                         /*
1293                          * On error, cmd_enable_channel call will take care of destroying
1294                          * the created channel if it was needed.
1295                          */
1296                         goto error;
1297                 }
1298
1299                 kernel_wait_quiescent(kernel_tracer_fd);
1300                 break;
1301         }
1302         case LTTNG_DOMAIN_UST:
1303         {
1304                 struct ltt_ust_channel *uchan;
1305                 struct ltt_ust_session *usess = session->ust_session;
1306
1307                 assert(usess);
1308
1309                 /* Get channel from global UST domain */
1310                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1311                                 channel_name);
1312                 if (uchan == NULL) {
1313                         /* Create default channel */
1314                         attr = channel_new_default_attr(domain);
1315                         if (attr == NULL) {
1316                                 ret = LTTNG_ERR_FATAL;
1317                                 goto error;
1318                         }
1319                         strncpy(attr->name, channel_name, sizeof(attr->name));
1320
1321                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1322                         if (ret != LTTNG_OK) {
1323                                 free(attr);
1324                                 goto error;
1325                         }
1326                         free(attr);
1327
1328                         /* Get the newly created channel reference back */
1329                         uchan = trace_ust_find_channel_by_name(
1330                                         usess->domain_global.channels, channel_name);
1331                         assert(uchan);
1332                 }
1333
1334                 /* At this point, the session and channel exist on the tracer */
1335
1336                 switch (event_type) {
1337                 case LTTNG_EVENT_ALL:
1338                 case LTTNG_EVENT_TRACEPOINT:
1339                         ret = event_ust_enable_all_tracepoints(usess, domain, uchan,
1340                                         filter);
1341                         if (ret != LTTNG_OK) {
1342                                 goto error;
1343                         }
1344                         break;
1345                 default:
1346                         ret = LTTNG_ERR_UST_ENABLE_FAIL;
1347                         goto error;
1348                 }
1349
1350                 /* Manage return value */
1351                 if (ret != LTTNG_OK) {
1352                         goto error;
1353                 }
1354
1355                 break;
1356         }
1357 #if 0
1358         case LTTNG_DOMAIN_UST_EXEC_NAME:
1359         case LTTNG_DOMAIN_UST_PID:
1360         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1361 #endif
1362         default:
1363                 ret = LTTNG_ERR_UND;
1364                 goto error;
1365         }
1366
1367         ret = LTTNG_OK;
1368
1369 error:
1370         return ret;
1371 }
1372
1373
1374 /*
1375  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1376  */
1377 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1378 {
1379         int ret;
1380         ssize_t nb_events = 0;
1381
1382         switch (domain) {
1383         case LTTNG_DOMAIN_KERNEL:
1384                 nb_events = kernel_list_events(kernel_tracer_fd, events);
1385                 if (nb_events < 0) {
1386                         ret = LTTNG_ERR_KERN_LIST_FAIL;
1387                         goto error;
1388                 }
1389                 break;
1390         case LTTNG_DOMAIN_UST:
1391                 nb_events = ust_app_list_events(events);
1392                 if (nb_events < 0) {
1393                         ret = LTTNG_ERR_UST_LIST_FAIL;
1394                         goto error;
1395                 }
1396                 break;
1397         default:
1398                 ret = LTTNG_ERR_UND;
1399                 goto error;
1400         }
1401
1402         return nb_events;
1403
1404 error:
1405         /* Return negative value to differentiate return code */
1406         return -ret;
1407 }
1408
1409 /*
1410  * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1411  */
1412 ssize_t cmd_list_tracepoint_fields(int domain,
1413                 struct lttng_event_field **fields)
1414 {
1415         int ret;
1416         ssize_t nb_fields = 0;
1417
1418         switch (domain) {
1419         case LTTNG_DOMAIN_UST:
1420                 nb_fields = ust_app_list_event_fields(fields);
1421                 if (nb_fields < 0) {
1422                         ret = LTTNG_ERR_UST_LIST_FAIL;
1423                         goto error;
1424                 }
1425                 break;
1426         case LTTNG_DOMAIN_KERNEL:
1427         default:        /* fall-through */
1428                 ret = LTTNG_ERR_UND;
1429                 goto error;
1430         }
1431
1432         return nb_fields;
1433
1434 error:
1435         /* Return negative value to differentiate return code */
1436         return -ret;
1437 }
1438
1439 /*
1440  * Command LTTNG_START_TRACE processed by the client thread.
1441  */
1442 int cmd_start_trace(struct ltt_session *session)
1443 {
1444         int ret;
1445         struct ltt_kernel_session *ksession;
1446         struct ltt_ust_session *usess;
1447
1448         assert(session);
1449
1450         /* Ease our life a bit ;) */
1451         ksession = session->kernel_session;
1452         usess = session->ust_session;
1453
1454         if (session->enabled) {
1455                 /* Already started. */
1456                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1457                 goto error;
1458         }
1459
1460         session->enabled = 1;
1461
1462         ret = setup_relayd(session);
1463         if (ret != LTTNG_OK) {
1464                 ERR("Error setting up relayd for session %s", session->name);
1465                 goto error;
1466         }
1467
1468         /* Kernel tracing */
1469         if (ksession != NULL) {
1470                 ret = start_kernel_session(ksession, kernel_tracer_fd);
1471                 if (ret != LTTNG_OK) {
1472                         goto error;
1473                 }
1474         }
1475
1476         /* Flag session that trace should start automatically */
1477         if (usess) {
1478                 usess->start_trace = 1;
1479
1480                 ret = ust_app_start_trace_all(usess);
1481                 if (ret < 0) {
1482                         ret = LTTNG_ERR_UST_START_FAIL;
1483                         goto error;
1484                 }
1485         }
1486
1487         session->started = 1;
1488
1489         ret = LTTNG_OK;
1490
1491 error:
1492         return ret;
1493 }
1494
1495 /*
1496  * Command LTTNG_STOP_TRACE processed by the client thread.
1497  */
1498 int cmd_stop_trace(struct ltt_session *session)
1499 {
1500         int ret;
1501         struct ltt_kernel_channel *kchan;
1502         struct ltt_kernel_session *ksession;
1503         struct ltt_ust_session *usess;
1504
1505         assert(session);
1506
1507         /* Short cut */
1508         ksession = session->kernel_session;
1509         usess = session->ust_session;
1510
1511         if (!session->enabled) {
1512                 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
1513                 goto error;
1514         }
1515
1516         session->enabled = 0;
1517
1518         /* Kernel tracer */
1519         if (ksession) {
1520                 DBG("Stop kernel tracing");
1521
1522                 /* Flush metadata if exist */
1523                 if (ksession->metadata_stream_fd >= 0) {
1524                         ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1525                         if (ret < 0) {
1526                                 ERR("Kernel metadata flush failed");
1527                         }
1528                 }
1529
1530                 /* Flush all buffers before stopping */
1531                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1532                         ret = kernel_flush_buffer(kchan);
1533                         if (ret < 0) {
1534                                 ERR("Kernel flush buffer error");
1535                         }
1536                 }
1537
1538                 ret = kernel_stop_session(ksession);
1539                 if (ret < 0) {
1540                         ret = LTTNG_ERR_KERN_STOP_FAIL;
1541                         goto error;
1542                 }
1543
1544                 kernel_wait_quiescent(kernel_tracer_fd);
1545
1546                 ksession->started = 0;
1547         }
1548
1549         if (usess) {
1550                 usess->start_trace = 0;
1551
1552                 ret = ust_app_stop_trace_all(usess);
1553                 if (ret < 0) {
1554                         ret = LTTNG_ERR_UST_STOP_FAIL;
1555                         goto error;
1556                 }
1557         }
1558
1559         session->started = 0;
1560
1561         ret = LTTNG_OK;
1562
1563 error:
1564         return ret;
1565 }
1566
1567 /*
1568  * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1569  */
1570 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1571                 size_t nb_uri, struct lttng_uri *uris)
1572 {
1573         int ret, i;
1574         struct ltt_kernel_session *ksess = session->kernel_session;
1575         struct ltt_ust_session *usess = session->ust_session;
1576         struct consumer_output *consumer = NULL;
1577
1578         assert(session);
1579         assert(uris);
1580         assert(nb_uri > 0);
1581
1582         /* Can't enable consumer after session started. */
1583         if (session->enabled) {
1584                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1585                 goto error;
1586         }
1587
1588         /*
1589          * This case switch makes sure the domain session has a temporary consumer
1590          * so the URL can be set.
1591          */
1592         switch (domain) {
1593         case 0:
1594                 /* Code flow error. A session MUST always have a consumer object */
1595                 assert(session->consumer);
1596                 /*
1597                  * The URL will be added to the tracing session consumer instead of a
1598                  * specific domain consumer.
1599                  */
1600                 consumer = session->consumer;
1601                 break;
1602         case LTTNG_DOMAIN_KERNEL:
1603                 /* Code flow error if we don't have a kernel session here. */
1604                 assert(ksess);
1605
1606                 /* Create consumer output if none exists */
1607                 consumer = ksess->tmp_consumer;
1608                 if (consumer == NULL) {
1609                         consumer = consumer_copy_output(ksess->consumer);
1610                         if (consumer == NULL) {
1611                                 ret = LTTNG_ERR_FATAL;
1612                                 goto error;
1613                         }
1614                         /* Trash the consumer subdir, we are about to set a new one. */
1615                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1616                         ksess->tmp_consumer = consumer;
1617                 }
1618
1619                 break;
1620         case LTTNG_DOMAIN_UST:
1621                 /* Code flow error if we don't have a kernel session here. */
1622                 assert(usess);
1623
1624                 /* Create consumer output if none exists */
1625                 consumer = usess->tmp_consumer;
1626                 if (consumer == NULL) {
1627                         consumer = consumer_copy_output(usess->consumer);
1628                         if (consumer == NULL) {
1629                                 ret = LTTNG_ERR_FATAL;
1630                                 goto error;
1631                         }
1632                         /* Trash the consumer subdir, we are about to set a new one. */
1633                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1634                         usess->tmp_consumer = consumer;
1635                 }
1636
1637                 break;
1638         }
1639
1640         for (i = 0; i < nb_uri; i++) {
1641                 struct consumer_socket *socket;
1642                 struct lttng_ht_iter iter;
1643
1644                 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1645                 if (ret < 0) {
1646                         goto error;
1647                 }
1648
1649                 /*
1650                  * Don't send relayd socket if URI is NOT remote or if the relayd
1651                  * socket for the session was already sent.
1652                  */
1653                 if (uris[i].dtype == LTTNG_DST_PATH ||
1654                                 (uris[i].stype == LTTNG_STREAM_CONTROL &&
1655                                 consumer->dst.net.control_sock_sent) ||
1656                                 (uris[i].stype == LTTNG_STREAM_DATA &&
1657                                 consumer->dst.net.data_sock_sent)) {
1658                         continue;
1659                 }
1660
1661                 /* Try to send relayd URI to the consumer if exist. */
1662                 rcu_read_lock();
1663                 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
1664                                 socket, node.node) {
1665
1666                         /* A socket in the HT should never have a negative fd */
1667                         assert(socket->fd >= 0);
1668
1669                         pthread_mutex_lock(socket->lock);
1670                         ret = send_consumer_relayd_socket(domain, session, &uris[i],
1671                                         consumer, socket);
1672                         pthread_mutex_unlock(socket->lock);
1673                         if (ret != LTTNG_OK) {
1674                                 rcu_read_unlock();
1675                                 goto error;
1676                         }
1677                 }
1678                 rcu_read_unlock();
1679         }
1680
1681         /* All good! */
1682         ret = LTTNG_OK;
1683
1684 error:
1685         return ret;
1686 }
1687
1688 /*
1689  * Command LTTNG_CREATE_SESSION processed by the client thread.
1690  */
1691 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1692                 size_t nb_uri, lttng_sock_cred *creds)
1693 {
1694         int ret;
1695         char *path = NULL;
1696         struct ltt_session *session;
1697
1698         assert(name);
1699
1700         /*
1701          * Verify if the session already exist
1702          *
1703          * XXX: There is no need for the session lock list here since the caller
1704          * (process_client_msg) is holding it. We might want to change that so a
1705          * single command does not lock the entire session list.
1706          */
1707         session = session_find_by_name(name);
1708         if (session != NULL) {
1709                 ret = LTTNG_ERR_EXIST_SESS;
1710                 goto find_error;
1711         }
1712
1713         /* Create tracing session in the registry */
1714         ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1715                         LTTNG_SOCK_GET_GID_CRED(creds));
1716         if (ret != LTTNG_OK) {
1717                 goto session_error;
1718         }
1719
1720         /*
1721          * Get the newly created session pointer back
1722          *
1723          * XXX: There is no need for the session lock list here since the caller
1724          * (process_client_msg) is holding it. We might want to change that so a
1725          * single command does not lock the entire session list.
1726          */
1727         session = session_find_by_name(name);
1728         assert(session);
1729
1730         /* Create default consumer output for the session not yet created. */
1731         session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1732         if (session->consumer == NULL) {
1733                 ret = LTTNG_ERR_FATAL;
1734                 goto consumer_error;
1735         }
1736
1737         /*
1738          * This means that the lttng_create_session call was called with the _path_
1739          * argument set to NULL.
1740          */
1741         if (uris == NULL) {
1742                 /*
1743                  * At this point, we'll skip the consumer URI setup and create a
1744                  * session with a NULL path which will flag the session to NOT spawn a
1745                  * consumer.
1746                  */
1747                 DBG("Create session %s with NO uri, skipping consumer setup", name);
1748                 goto end;
1749         }
1750
1751         session->start_consumer = 1;
1752
1753         ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1754         if (ret != LTTNG_OK) {
1755                 goto consumer_error;
1756         }
1757
1758         session->consumer->enabled = 1;
1759
1760 end:
1761         return LTTNG_OK;
1762
1763 consumer_error:
1764         session_destroy(session);
1765 session_error:
1766 find_error:
1767         return ret;
1768 }
1769
1770 /*
1771  * Command LTTNG_DESTROY_SESSION processed by the client thread.
1772  */
1773 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1774 {
1775         int ret;
1776         struct ltt_ust_session *usess;
1777         struct ltt_kernel_session *ksess;
1778
1779         /* Safety net */
1780         assert(session);
1781
1782         usess = session->ust_session;
1783         ksess = session->kernel_session;
1784
1785         /* Clean kernel session teardown */
1786         kernel_destroy_session(ksess);
1787
1788         /* UST session teardown */
1789         if (usess) {
1790                 /* Close any relayd session */
1791                 consumer_output_send_destroy_relayd(usess->consumer);
1792
1793                 /* Destroy every UST application related to this session. */
1794                 ret = ust_app_destroy_trace_all(usess);
1795                 if (ret) {
1796                         ERR("Error in ust_app_destroy_trace_all");
1797                 }
1798
1799                 /* Clean up the rest. */
1800                 trace_ust_destroy_session(usess);
1801         }
1802
1803         /*
1804          * Must notify the kernel thread here to update it's poll set in order to
1805          * remove the channel(s)' fd just destroyed.
1806          */
1807         ret = notify_thread_pipe(wpipe);
1808         if (ret < 0) {
1809                 PERROR("write kernel poll pipe");
1810         }
1811
1812         ret = session_destroy(session);
1813
1814         return ret;
1815 }
1816
1817 /*
1818  * Command LTTNG_CALIBRATE processed by the client thread.
1819  */
1820 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1821 {
1822         int ret;
1823
1824         switch (domain) {
1825         case LTTNG_DOMAIN_KERNEL:
1826         {
1827                 struct lttng_kernel_calibrate kcalibrate;
1828
1829                 kcalibrate.type = calibrate->type;
1830                 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1831                 if (ret < 0) {
1832                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1833                         goto error;
1834                 }
1835                 break;
1836         }
1837         case LTTNG_DOMAIN_UST:
1838         {
1839                 struct lttng_ust_calibrate ucalibrate;
1840
1841                 ucalibrate.type = calibrate->type;
1842                 ret = ust_app_calibrate_glb(&ucalibrate);
1843                 if (ret < 0) {
1844                         ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
1845                         goto error;
1846                 }
1847                 break;
1848         }
1849         default:
1850                 ret = LTTNG_ERR_UND;
1851                 goto error;
1852         }
1853
1854         ret = LTTNG_OK;
1855
1856 error:
1857         return ret;
1858 }
1859
1860 /*
1861  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1862  */
1863 int cmd_register_consumer(struct ltt_session *session, int domain,
1864                 const char *sock_path, struct consumer_data *cdata)
1865 {
1866         int ret, sock;
1867         struct consumer_socket *socket;
1868
1869         assert(session);
1870         assert(cdata);
1871         assert(sock_path);
1872
1873         switch (domain) {
1874         case LTTNG_DOMAIN_KERNEL:
1875         {
1876                 struct ltt_kernel_session *ksess = session->kernel_session;
1877
1878                 assert(ksess);
1879
1880                 /* Can't register a consumer if there is already one */
1881                 if (ksess->consumer_fds_sent != 0) {
1882                         ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1883                         goto error;
1884                 }
1885
1886                 sock = lttcomm_connect_unix_sock(sock_path);
1887                 if (sock < 0) {
1888                         ret = LTTNG_ERR_CONNECT_FAIL;
1889                         goto error;
1890                 }
1891
1892                 socket = consumer_allocate_socket(sock);
1893                 if (socket == NULL) {
1894                         ret = close(sock);
1895                         if (ret < 0) {
1896                                 PERROR("close register consumer");
1897                         }
1898                         ret = LTTNG_ERR_FATAL;
1899                         goto error;
1900                 }
1901
1902                 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1903                 if (socket->lock == NULL) {
1904                         PERROR("zmalloc pthread mutex");
1905                         ret = LTTNG_ERR_FATAL;
1906                         goto error;
1907                 }
1908                 pthread_mutex_init(socket->lock, NULL);
1909                 socket->registered = 1;
1910
1911                 rcu_read_lock();
1912                 consumer_add_socket(socket, ksess->consumer);
1913                 rcu_read_unlock();
1914
1915                 pthread_mutex_lock(&cdata->pid_mutex);
1916                 cdata->pid = -1;
1917                 pthread_mutex_unlock(&cdata->pid_mutex);
1918
1919                 break;
1920         }
1921         default:
1922                 /* TODO: Userspace tracing */
1923                 ret = LTTNG_ERR_UND;
1924                 goto error;
1925         }
1926
1927         ret = LTTNG_OK;
1928
1929 error:
1930         return ret;
1931 }
1932
1933 /*
1934  * Command LTTNG_LIST_DOMAINS processed by the client thread.
1935  */
1936 ssize_t cmd_list_domains(struct ltt_session *session,
1937                 struct lttng_domain **domains)
1938 {
1939         int ret, index = 0;
1940         ssize_t nb_dom = 0;
1941
1942         if (session->kernel_session != NULL) {
1943                 DBG3("Listing domains found kernel domain");
1944                 nb_dom++;
1945         }
1946
1947         if (session->ust_session != NULL) {
1948                 DBG3("Listing domains found UST global domain");
1949                 nb_dom++;
1950         }
1951
1952         *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1953         if (*domains == NULL) {
1954                 ret = LTTNG_ERR_FATAL;
1955                 goto error;
1956         }
1957
1958         if (session->kernel_session != NULL) {
1959                 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1960                 index++;
1961         }
1962
1963         if (session->ust_session != NULL) {
1964                 (*domains)[index].type = LTTNG_DOMAIN_UST;
1965                 index++;
1966         }
1967
1968         return nb_dom;
1969
1970 error:
1971         /* Return negative value to differentiate return code */
1972         return -ret;
1973 }
1974
1975
1976 /*
1977  * Command LTTNG_LIST_CHANNELS processed by the client thread.
1978  */
1979 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
1980                 struct lttng_channel **channels)
1981 {
1982         int ret;
1983         ssize_t nb_chan = 0;
1984
1985         switch (domain) {
1986         case LTTNG_DOMAIN_KERNEL:
1987                 if (session->kernel_session != NULL) {
1988                         nb_chan = session->kernel_session->channel_count;
1989                 }
1990                 DBG3("Number of kernel channels %zd", nb_chan);
1991                 if (nb_chan <= 0) {
1992                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1993                 }
1994                 break;
1995         case LTTNG_DOMAIN_UST:
1996                 if (session->ust_session != NULL) {
1997                         nb_chan = lttng_ht_get_count(
1998                                         session->ust_session->domain_global.channels);
1999                 }
2000                 DBG3("Number of UST global channels %zd", nb_chan);
2001                 if (nb_chan <= 0) {
2002                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2003                 }
2004                 break;
2005         default:
2006                 *channels = NULL;
2007                 ret = LTTNG_ERR_UND;
2008                 goto error;
2009         }
2010
2011         if (nb_chan > 0) {
2012                 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2013                 if (*channels == NULL) {
2014                         ret = LTTNG_ERR_FATAL;
2015                         goto error;
2016                 }
2017
2018                 list_lttng_channels(domain, session, *channels);
2019         } else {
2020                 *channels = NULL;
2021                 /* Ret value was set in the domain switch case */
2022                 goto error;
2023         }
2024
2025         return nb_chan;
2026
2027 error:
2028         /* Return negative value to differentiate return code */
2029         return -ret;
2030 }
2031
2032 /*
2033  * Command LTTNG_LIST_EVENTS processed by the client thread.
2034  */
2035 ssize_t cmd_list_events(int domain, struct ltt_session *session,
2036                 char *channel_name, struct lttng_event **events)
2037 {
2038         int ret = 0;
2039         ssize_t nb_event = 0;
2040
2041         switch (domain) {
2042         case LTTNG_DOMAIN_KERNEL:
2043                 if (session->kernel_session != NULL) {
2044                         nb_event = list_lttng_kernel_events(channel_name,
2045                                         session->kernel_session, events);
2046                 }
2047                 break;
2048         case LTTNG_DOMAIN_UST:
2049         {
2050                 if (session->ust_session != NULL) {
2051                         nb_event = list_lttng_ust_global_events(channel_name,
2052                                         &session->ust_session->domain_global, events);
2053                 }
2054                 break;
2055         }
2056         default:
2057                 ret = LTTNG_ERR_UND;
2058                 goto error;
2059         }
2060
2061         return nb_event;
2062
2063 error:
2064         /* Return negative value to differentiate return code */
2065         return -ret;
2066 }
2067
2068 /*
2069  * Using the session list, filled a lttng_session array to send back to the
2070  * client for session listing.
2071  *
2072  * The session list lock MUST be acquired before calling this function. Use
2073  * session_lock_list() and session_unlock_list().
2074  */
2075 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2076                 gid_t gid)
2077 {
2078         int ret;
2079         unsigned int i = 0;
2080         struct ltt_session *session;
2081         struct ltt_session_list *list = session_get_list();
2082
2083         DBG("Getting all available session for UID %d GID %d",
2084                         uid, gid);
2085         /*
2086          * Iterate over session list and append data after the control struct in
2087          * the buffer.
2088          */
2089         cds_list_for_each_entry(session, &list->head, list) {
2090                 /*
2091                  * Only list the sessions the user can control.
2092                  */
2093                 if (!session_access_ok(session, uid, gid)) {
2094                         continue;
2095                 }
2096
2097                 struct ltt_kernel_session *ksess = session->kernel_session;
2098                 struct ltt_ust_session *usess = session->ust_session;
2099
2100                 if (session->consumer->type == CONSUMER_DST_NET ||
2101                                 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2102                                 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2103                         ret = build_network_session_path(sessions[i].path,
2104                                         sizeof(session[i].path), session);
2105                 } else {
2106                         ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2107                                         session->consumer->dst.trace_path);
2108                 }
2109                 if (ret < 0) {
2110                         PERROR("snprintf session path");
2111                         continue;
2112                 }
2113
2114                 strncpy(sessions[i].name, session->name, NAME_MAX);
2115                 sessions[i].name[NAME_MAX - 1] = '\0';
2116                 sessions[i].enabled = session->enabled;
2117                 i++;
2118         }
2119 }
2120
2121 /*
2122  * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2123  */
2124 int cmd_disable_consumer(int domain, struct ltt_session *session)
2125 {
2126         int ret;
2127         struct ltt_kernel_session *ksess = session->kernel_session;
2128         struct ltt_ust_session *usess = session->ust_session;
2129         struct consumer_output *consumer;
2130
2131         assert(session);
2132
2133         if (session->enabled) {
2134                 /* Can't disable consumer on an already started session */
2135                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2136                 goto error;
2137         }
2138
2139         if (!session->start_consumer) {
2140                 ret = LTTNG_ERR_NO_CONSUMER;
2141                 goto error;
2142         }
2143
2144         switch (domain) {
2145         case 0:
2146                 DBG("Disable tracing session %s consumer", session->name);
2147                 consumer = session->consumer;
2148                 break;
2149         case LTTNG_DOMAIN_KERNEL:
2150                 /* Code flow error if we don't have a kernel session here. */
2151                 assert(ksess);
2152
2153                 DBG("Disabling kernel consumer");
2154                 consumer = ksess->consumer;
2155
2156                 break;
2157         case LTTNG_DOMAIN_UST:
2158                 /* Code flow error if we don't have a UST session here. */
2159                 assert(usess);
2160
2161                 DBG("Disabling UST consumer");
2162                 consumer = usess->consumer;
2163
2164                 break;
2165         default:
2166                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
2167                 goto error;
2168         }
2169
2170         if (consumer) {
2171                 consumer->enabled = 0;
2172                 /* Success at this point */
2173                 ret = LTTNG_OK;
2174         } else {
2175                 ret = LTTNG_ERR_NO_CONSUMER;
2176         }
2177
2178 error:
2179         return ret;
2180 }
2181
2182 /*
2183  * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2184  */
2185 int cmd_enable_consumer(int domain, struct ltt_session *session)
2186 {
2187         int ret;
2188         struct ltt_kernel_session *ksess = session->kernel_session;
2189         struct ltt_ust_session *usess = session->ust_session;
2190         struct consumer_output *consumer = NULL;
2191
2192         assert(session);
2193
2194         /* Can't enable consumer after session started. */
2195         if (session->enabled) {
2196                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2197                 goto error;
2198         }
2199
2200         switch (domain) {
2201         case 0:
2202                 assert(session->consumer);
2203                 consumer = session->consumer;
2204                 break;
2205         case LTTNG_DOMAIN_KERNEL:
2206                 /* Code flow error if we don't have a kernel session here. */
2207                 assert(ksess);
2208
2209                 /*
2210                  * Check if we have already sent fds to the consumer. In that case,
2211                  * the enable-consumer command can't be used because a start trace
2212                  * had previously occured.
2213                  */
2214                 if (ksess->consumer_fds_sent) {
2215                         ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2216                         goto error;
2217                 }
2218
2219                 consumer = ksess->tmp_consumer;
2220                 if (consumer == NULL) {
2221                         ret = LTTNG_OK;
2222                         /* No temp. consumer output exists. Using the current one. */
2223                         DBG3("No temporary consumer. Using default");
2224                         consumer = ksess->consumer;
2225                         goto error;
2226                 }
2227
2228                 switch (consumer->type) {
2229                 case CONSUMER_DST_LOCAL:
2230                         DBG2("Consumer output is local. Creating directory(ies)");
2231
2232                         /* Create directory(ies) */
2233                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2234                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2235                         if (ret < 0) {
2236                                 if (ret != -EEXIST) {
2237                                         ERR("Trace directory creation error");
2238                                         ret = LTTNG_ERR_FATAL;
2239                                         goto error;
2240                                 }
2241                         }
2242                         break;
2243                 case CONSUMER_DST_NET:
2244                         DBG2("Consumer output is network. Validating URIs");
2245                         /* Validate if we have both control and data path set. */
2246                         if (!consumer->dst.net.control_isset) {
2247                                 ret = LTTNG_ERR_URL_CTRL_MISS;
2248                                 goto error;
2249                         }
2250
2251                         if (!consumer->dst.net.data_isset) {
2252                                 ret = LTTNG_ERR_URL_DATA_MISS;
2253                                 goto error;
2254                         }
2255
2256                         /* Check established network session state */
2257                         if (session->net_handle == 0) {
2258                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2259                                 ERR("Session network handle is not set on enable-consumer");
2260                                 goto error;
2261                         }
2262
2263                         break;
2264                 }
2265
2266                 /*
2267                  * @session-lock
2268                  * This is race free for now since the session lock is acquired before
2269                  * ending up in this function. No other threads can access this kernel
2270                  * session without this lock hence freeing the consumer output object
2271                  * is valid.
2272                  */
2273                 rcu_read_lock();
2274                 /* Destroy current consumer. We are about to replace it */
2275                 consumer_destroy_output(ksess->consumer);
2276                 rcu_read_unlock();
2277                 ksess->consumer = consumer;
2278                 ksess->tmp_consumer = NULL;
2279
2280                 break;
2281         case LTTNG_DOMAIN_UST:
2282                 /* Code flow error if we don't have a UST session here. */
2283                 assert(usess);
2284
2285                 /*
2286                  * Check if we have already sent fds to the consumer. In that case,
2287                  * the enable-consumer command can't be used because a start trace
2288                  * had previously occured.
2289                  */
2290                 if (usess->start_trace) {
2291                         ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2292                         goto error;
2293                 }
2294
2295                 consumer = usess->tmp_consumer;
2296                 if (consumer == NULL) {
2297                         ret = LTTNG_OK;
2298                         /* No temp. consumer output exists. Using the current one. */
2299                         DBG3("No temporary consumer. Using default");
2300                         consumer = usess->consumer;
2301                         goto error;
2302                 }
2303
2304                 switch (consumer->type) {
2305                 case CONSUMER_DST_LOCAL:
2306                         DBG2("Consumer output is local. Creating directory(ies)");
2307
2308                         /* Create directory(ies) */
2309                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2310                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2311                         if (ret < 0) {
2312                                 if (ret != -EEXIST) {
2313                                         ERR("Trace directory creation error");
2314                                         ret = LTTNG_ERR_FATAL;
2315                                         goto error;
2316                                 }
2317                         }
2318                         break;
2319                 case CONSUMER_DST_NET:
2320                         DBG2("Consumer output is network. Validating URIs");
2321                         /* Validate if we have both control and data path set. */
2322                         if (!consumer->dst.net.control_isset) {
2323                                 ret = LTTNG_ERR_URL_CTRL_MISS;
2324                                 goto error;
2325                         }
2326
2327                         if (!consumer->dst.net.data_isset) {
2328                                 ret = LTTNG_ERR_URL_DATA_MISS;
2329                                 goto error;
2330                         }
2331
2332                         /* Check established network session state */
2333                         if (session->net_handle == 0) {
2334                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2335                                 DBG2("Session network handle is not set on enable-consumer");
2336                                 goto error;
2337                         }
2338
2339                         if (consumer->net_seq_index == -1) {
2340                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2341                                 DBG2("Network index is not set on the consumer");
2342                                 goto error;
2343                         }
2344
2345                         break;
2346                 }
2347
2348                 /*
2349                  * @session-lock
2350                  * This is race free for now since the session lock is acquired before
2351                  * ending up in this function. No other threads can access this kernel
2352                  * session without this lock hence freeing the consumer output object
2353                  * is valid.
2354                  */
2355                 rcu_read_lock();
2356                 /* Destroy current consumer. We are about to replace it */
2357                 consumer_destroy_output(usess->consumer);
2358                 rcu_read_unlock();
2359                 usess->consumer = consumer;
2360                 usess->tmp_consumer = NULL;
2361
2362                 break;
2363         }
2364
2365         session->start_consumer = 1;
2366
2367         /* Enable it */
2368         if (consumer) {
2369                 consumer->enabled = 1;
2370                 /* Success at this point */
2371                 ret = LTTNG_OK;
2372         } else {
2373                 /* Should not really happend... */
2374                 ret = LTTNG_ERR_NO_CONSUMER;
2375         }
2376
2377 error:
2378         return ret;
2379 }
2380
2381 /*
2382  * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
2383  * ready for trace analysis (or anykind of reader) or else 1 for pending data.
2384  */
2385 int cmd_data_pending(struct ltt_session *session)
2386 {
2387         int ret;
2388         struct ltt_kernel_session *ksess = session->kernel_session;
2389         struct ltt_ust_session *usess = session->ust_session;
2390
2391         assert(session);
2392
2393         /* Session MUST be stopped to ask for data availability. */
2394         if (session->enabled) {
2395                 ret = LTTNG_ERR_SESSION_STARTED;
2396                 goto error;
2397         }
2398
2399         if (ksess && ksess->consumer) {
2400                 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
2401                 if (ret == 1) {
2402                         /* Data is still being extracted for the kernel. */
2403                         goto error;
2404                 }
2405         }
2406
2407         if (usess && usess->consumer) {
2408                 ret = consumer_is_data_pending(usess->id, usess->consumer);
2409                 if (ret == 1) {
2410                         /* Data is still being extracted for the kernel. */
2411                         goto error;
2412                 }
2413         }
2414
2415         /* Data is ready to be read by a viewer */
2416         ret = 0;
2417
2418 error:
2419         return ret;
2420 }
2421
2422 /*
2423  * Init command subsystem.
2424  */
2425 void cmd_init(void)
2426 {
2427         /*
2428          * Set network sequence index to 1 for streams to match a relayd socket on
2429          * the consumer side.
2430          */
2431         uatomic_set(&relayd_net_seq_idx, 1);
2432
2433         DBG("Command subsystem initialized");
2434 }