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