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(ksess, 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(ksess, 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(session->kernel_session, kchan,
1164                                 event);
1165                 if (ret != LTTNG_OK) {
1166                         if (channel_created) {
1167                                 /* Let's not leak a useless channel. */
1168                                 kernel_destroy_channel(kchan);
1169                         }
1170                         goto error;
1171                 }
1172
1173                 kernel_wait_quiescent(kernel_tracer_fd);
1174                 break;
1175         }
1176         case LTTNG_DOMAIN_UST:
1177         {
1178                 struct ltt_ust_channel *uchan;
1179                 struct ltt_ust_session *usess = session->ust_session;
1180
1181                 assert(usess);
1182
1183                 /* Get channel from global UST domain */
1184                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1185                                 channel_name);
1186                 if (uchan == NULL) {
1187                         /* Create default channel */
1188                         attr = channel_new_default_attr(domain);
1189                         if (attr == NULL) {
1190                                 ret = LTTNG_ERR_FATAL;
1191                                 goto error;
1192                         }
1193                         strncpy(attr->name, channel_name, sizeof(attr->name));
1194
1195                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1196                         if (ret != LTTNG_OK) {
1197                                 free(attr);
1198                                 goto error;
1199                         }
1200                         free(attr);
1201
1202                         /* Get the newly created channel reference back */
1203                         uchan = trace_ust_find_channel_by_name(
1204                                         usess->domain_global.channels, channel_name);
1205                         assert(uchan);
1206                 }
1207
1208                 /* At this point, the session and channel exist on the tracer */
1209                 ret = event_ust_enable_tracepoint(usess, domain, uchan, event, filter);
1210                 if (ret != LTTNG_OK) {
1211                         goto error;
1212                 }
1213                 break;
1214         }
1215 #if 0
1216         case LTTNG_DOMAIN_UST_EXEC_NAME:
1217         case LTTNG_DOMAIN_UST_PID:
1218         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1219 #endif
1220         default:
1221                 ret = LTTNG_ERR_UND;
1222                 goto error;
1223         }
1224
1225         ret = LTTNG_OK;
1226
1227 error:
1228         return ret;
1229 }
1230
1231 /*
1232  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1233  */
1234 int cmd_enable_event_all(struct ltt_session *session, int domain,
1235                 char *channel_name, int event_type,
1236                 struct lttng_filter_bytecode *filter, int wpipe)
1237 {
1238         int ret;
1239         struct lttng_channel *attr;
1240
1241         assert(session);
1242         assert(channel_name);
1243
1244         switch (domain) {
1245         case LTTNG_DOMAIN_KERNEL:
1246         {
1247                 struct ltt_kernel_channel *kchan;
1248
1249                 assert(session->kernel_session);
1250
1251                 kchan = trace_kernel_get_channel_by_name(channel_name,
1252                                 session->kernel_session);
1253                 if (kchan == NULL) {
1254                         /* Create default channel */
1255                         attr = channel_new_default_attr(domain);
1256                         if (attr == NULL) {
1257                                 ret = LTTNG_ERR_FATAL;
1258                                 goto error;
1259                         }
1260                         strncpy(attr->name, channel_name, sizeof(attr->name));
1261
1262                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1263                         if (ret != LTTNG_OK) {
1264                                 free(attr);
1265                                 goto error;
1266                         }
1267                         free(attr);
1268
1269                         /* Get the newly created kernel channel pointer */
1270                         kchan = trace_kernel_get_channel_by_name(channel_name,
1271                                         session->kernel_session);
1272                         assert(kchan);
1273                 }
1274
1275                 switch (event_type) {
1276                 case LTTNG_EVENT_SYSCALL:
1277                         ret = event_kernel_enable_all_syscalls(session->kernel_session,
1278                                         kchan, kernel_tracer_fd);
1279                         break;
1280                 case LTTNG_EVENT_TRACEPOINT:
1281                         /*
1282                          * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1283                          * events already registered to the channel.
1284                          */
1285                         ret = event_kernel_enable_all_tracepoints(session->kernel_session,
1286                                         kchan, kernel_tracer_fd);
1287                         break;
1288                 case LTTNG_EVENT_ALL:
1289                         /* Enable syscalls and tracepoints */
1290                         ret = event_kernel_enable_all(session->kernel_session,
1291                                         kchan, kernel_tracer_fd);
1292                         break;
1293                 default:
1294                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1295                         goto error;
1296                 }
1297
1298                 /* Manage return value */
1299                 if (ret != LTTNG_OK) {
1300                         /*
1301                          * On error, cmd_enable_channel call will take care of destroying
1302                          * the created channel if it was needed.
1303                          */
1304                         goto error;
1305                 }
1306
1307                 kernel_wait_quiescent(kernel_tracer_fd);
1308                 break;
1309         }
1310         case LTTNG_DOMAIN_UST:
1311         {
1312                 struct ltt_ust_channel *uchan;
1313                 struct ltt_ust_session *usess = session->ust_session;
1314
1315                 assert(usess);
1316
1317                 /* Get channel from global UST domain */
1318                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1319                                 channel_name);
1320                 if (uchan == NULL) {
1321                         /* Create default channel */
1322                         attr = channel_new_default_attr(domain);
1323                         if (attr == NULL) {
1324                                 ret = LTTNG_ERR_FATAL;
1325                                 goto error;
1326                         }
1327                         strncpy(attr->name, channel_name, sizeof(attr->name));
1328
1329                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1330                         if (ret != LTTNG_OK) {
1331                                 free(attr);
1332                                 goto error;
1333                         }
1334                         free(attr);
1335
1336                         /* Get the newly created channel reference back */
1337                         uchan = trace_ust_find_channel_by_name(
1338                                         usess->domain_global.channels, channel_name);
1339                         assert(uchan);
1340                 }
1341
1342                 /* At this point, the session and channel exist on the tracer */
1343
1344                 switch (event_type) {
1345                 case LTTNG_EVENT_ALL:
1346                 case LTTNG_EVENT_TRACEPOINT:
1347                         ret = event_ust_enable_all_tracepoints(usess, domain, uchan,
1348                                         filter);
1349                         if (ret != LTTNG_OK) {
1350                                 goto error;
1351                         }
1352                         break;
1353                 default:
1354                         ret = LTTNG_ERR_UST_ENABLE_FAIL;
1355                         goto error;
1356                 }
1357
1358                 /* Manage return value */
1359                 if (ret != LTTNG_OK) {
1360                         goto error;
1361                 }
1362
1363                 break;
1364         }
1365 #if 0
1366         case LTTNG_DOMAIN_UST_EXEC_NAME:
1367         case LTTNG_DOMAIN_UST_PID:
1368         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1369 #endif
1370         default:
1371                 ret = LTTNG_ERR_UND;
1372                 goto error;
1373         }
1374
1375         ret = LTTNG_OK;
1376
1377 error:
1378         return ret;
1379 }
1380
1381
1382 /*
1383  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1384  */
1385 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1386 {
1387         int ret;
1388         ssize_t nb_events = 0;
1389
1390         switch (domain) {
1391         case LTTNG_DOMAIN_KERNEL:
1392                 nb_events = kernel_list_events(kernel_tracer_fd, events);
1393                 if (nb_events < 0) {
1394                         ret = LTTNG_ERR_KERN_LIST_FAIL;
1395                         goto error;
1396                 }
1397                 break;
1398         case LTTNG_DOMAIN_UST:
1399                 nb_events = ust_app_list_events(events);
1400                 if (nb_events < 0) {
1401                         ret = LTTNG_ERR_UST_LIST_FAIL;
1402                         goto error;
1403                 }
1404                 break;
1405         default:
1406                 ret = LTTNG_ERR_UND;
1407                 goto error;
1408         }
1409
1410         return nb_events;
1411
1412 error:
1413         /* Return negative value to differentiate return code */
1414         return -ret;
1415 }
1416
1417 /*
1418  * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1419  */
1420 ssize_t cmd_list_tracepoint_fields(int domain,
1421                 struct lttng_event_field **fields)
1422 {
1423         int ret;
1424         ssize_t nb_fields = 0;
1425
1426         switch (domain) {
1427         case LTTNG_DOMAIN_UST:
1428                 nb_fields = ust_app_list_event_fields(fields);
1429                 if (nb_fields < 0) {
1430                         ret = LTTNG_ERR_UST_LIST_FAIL;
1431                         goto error;
1432                 }
1433                 break;
1434         case LTTNG_DOMAIN_KERNEL:
1435         default:        /* fall-through */
1436                 ret = LTTNG_ERR_UND;
1437                 goto error;
1438         }
1439
1440         return nb_fields;
1441
1442 error:
1443         /* Return negative value to differentiate return code */
1444         return -ret;
1445 }
1446
1447 /*
1448  * Command LTTNG_START_TRACE processed by the client thread.
1449  */
1450 int cmd_start_trace(struct ltt_session *session)
1451 {
1452         int ret;
1453         struct ltt_kernel_session *ksession;
1454         struct ltt_ust_session *usess;
1455
1456         assert(session);
1457
1458         /* Ease our life a bit ;) */
1459         ksession = session->kernel_session;
1460         usess = session->ust_session;
1461
1462         if (session->enabled) {
1463                 /* Already started. */
1464                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1465                 goto error;
1466         }
1467
1468         session->enabled = 1;
1469
1470         ret = setup_relayd(session);
1471         if (ret != LTTNG_OK) {
1472                 ERR("Error setting up relayd for session %s", session->name);
1473                 goto error;
1474         }
1475
1476         /* Kernel tracing */
1477         if (ksession != NULL) {
1478                 ret = start_kernel_session(ksession, kernel_tracer_fd);
1479                 if (ret != LTTNG_OK) {
1480                         goto error;
1481                 }
1482         }
1483
1484         /* Flag session that trace should start automatically */
1485         if (usess) {
1486                 usess->start_trace = 1;
1487
1488                 ret = ust_app_start_trace_all(usess);
1489                 if (ret < 0) {
1490                         ret = LTTNG_ERR_UST_START_FAIL;
1491                         goto error;
1492                 }
1493         }
1494
1495         session->started = 1;
1496
1497         ret = LTTNG_OK;
1498
1499 error:
1500         return ret;
1501 }
1502
1503 /*
1504  * Command LTTNG_STOP_TRACE processed by the client thread.
1505  */
1506 int cmd_stop_trace(struct ltt_session *session)
1507 {
1508         int ret;
1509         struct ltt_kernel_channel *kchan;
1510         struct ltt_kernel_session *ksession;
1511         struct ltt_ust_session *usess;
1512
1513         assert(session);
1514
1515         /* Short cut */
1516         ksession = session->kernel_session;
1517         usess = session->ust_session;
1518
1519         if (!session->enabled) {
1520                 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
1521                 goto error;
1522         }
1523
1524         session->enabled = 0;
1525
1526         /* Kernel tracer */
1527         if (ksession) {
1528                 DBG("Stop kernel tracing");
1529
1530                 /* Flush metadata if exist */
1531                 if (ksession->metadata_stream_fd >= 0) {
1532                         ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1533                         if (ret < 0) {
1534                                 ERR("Kernel metadata flush failed");
1535                         }
1536                 }
1537
1538                 /* Flush all buffers before stopping */
1539                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1540                         ret = kernel_flush_buffer(kchan);
1541                         if (ret < 0) {
1542                                 ERR("Kernel flush buffer error");
1543                         }
1544                 }
1545
1546                 ret = kernel_stop_session(ksession);
1547                 if (ret < 0) {
1548                         ret = LTTNG_ERR_KERN_STOP_FAIL;
1549                         goto error;
1550                 }
1551
1552                 kernel_wait_quiescent(kernel_tracer_fd);
1553
1554                 ksession->started = 0;
1555         }
1556
1557         if (usess) {
1558                 usess->start_trace = 0;
1559
1560                 ret = ust_app_stop_trace_all(usess);
1561                 if (ret < 0) {
1562                         ret = LTTNG_ERR_UST_STOP_FAIL;
1563                         goto error;
1564                 }
1565         }
1566
1567         session->started = 0;
1568
1569         ret = LTTNG_OK;
1570
1571 error:
1572         return ret;
1573 }
1574
1575 /*
1576  * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1577  */
1578 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1579                 size_t nb_uri, struct lttng_uri *uris)
1580 {
1581         int ret, i;
1582         struct ltt_kernel_session *ksess = session->kernel_session;
1583         struct ltt_ust_session *usess = session->ust_session;
1584         struct consumer_output *consumer = NULL;
1585
1586         assert(session);
1587         assert(uris);
1588         assert(nb_uri > 0);
1589
1590         /* Can't enable consumer after session started. */
1591         if (session->enabled) {
1592                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1593                 goto error;
1594         }
1595
1596         /*
1597          * This case switch makes sure the domain session has a temporary consumer
1598          * so the URL can be set.
1599          */
1600         switch (domain) {
1601         case 0:
1602                 /* Code flow error. A session MUST always have a consumer object */
1603                 assert(session->consumer);
1604                 /*
1605                  * The URL will be added to the tracing session consumer instead of a
1606                  * specific domain consumer.
1607                  */
1608                 consumer = session->consumer;
1609                 break;
1610         case LTTNG_DOMAIN_KERNEL:
1611                 /* Code flow error if we don't have a kernel session here. */
1612                 assert(ksess);
1613
1614                 /* Create consumer output if none exists */
1615                 consumer = ksess->tmp_consumer;
1616                 if (consumer == NULL) {
1617                         consumer = consumer_copy_output(ksess->consumer);
1618                         if (consumer == NULL) {
1619                                 ret = LTTNG_ERR_FATAL;
1620                                 goto error;
1621                         }
1622                         /* Trash the consumer subdir, we are about to set a new one. */
1623                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1624                         ksess->tmp_consumer = consumer;
1625                 }
1626
1627                 break;
1628         case LTTNG_DOMAIN_UST:
1629                 /* Code flow error if we don't have a kernel session here. */
1630                 assert(usess);
1631
1632                 /* Create consumer output if none exists */
1633                 consumer = usess->tmp_consumer;
1634                 if (consumer == NULL) {
1635                         consumer = consumer_copy_output(usess->consumer);
1636                         if (consumer == NULL) {
1637                                 ret = LTTNG_ERR_FATAL;
1638                                 goto error;
1639                         }
1640                         /* Trash the consumer subdir, we are about to set a new one. */
1641                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1642                         usess->tmp_consumer = consumer;
1643                 }
1644
1645                 break;
1646         }
1647
1648         for (i = 0; i < nb_uri; i++) {
1649                 struct consumer_socket *socket;
1650                 struct lttng_ht_iter iter;
1651
1652                 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1653                 if (ret < 0) {
1654                         goto error;
1655                 }
1656
1657                 /*
1658                  * Don't send relayd socket if URI is NOT remote or if the relayd
1659                  * socket for the session was already sent.
1660                  */
1661                 if (uris[i].dtype == LTTNG_DST_PATH ||
1662                                 (uris[i].stype == LTTNG_STREAM_CONTROL &&
1663                                 consumer->dst.net.control_sock_sent) ||
1664                                 (uris[i].stype == LTTNG_STREAM_DATA &&
1665                                 consumer->dst.net.data_sock_sent)) {
1666                         continue;
1667                 }
1668
1669                 /* Try to send relayd URI to the consumer if exist. */
1670                 rcu_read_lock();
1671                 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
1672                                 socket, node.node) {
1673
1674                         /* A socket in the HT should never have a negative fd */
1675                         assert(socket->fd >= 0);
1676
1677                         pthread_mutex_lock(socket->lock);
1678                         ret = send_consumer_relayd_socket(domain, session, &uris[i],
1679                                         consumer, socket);
1680                         pthread_mutex_unlock(socket->lock);
1681                         if (ret != LTTNG_OK) {
1682                                 rcu_read_unlock();
1683                                 goto error;
1684                         }
1685                 }
1686                 rcu_read_unlock();
1687         }
1688
1689         /* All good! */
1690         ret = LTTNG_OK;
1691
1692 error:
1693         return ret;
1694 }
1695
1696 /*
1697  * Command LTTNG_CREATE_SESSION processed by the client thread.
1698  */
1699 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1700                 size_t nb_uri, lttng_sock_cred *creds)
1701 {
1702         int ret;
1703         char *path = NULL;
1704         struct ltt_session *session;
1705
1706         assert(name);
1707
1708         /*
1709          * Verify if the session already exist
1710          *
1711          * XXX: There is no need for the session lock list here since the caller
1712          * (process_client_msg) is holding it. We might want to change that so a
1713          * single command does not lock the entire session list.
1714          */
1715         session = session_find_by_name(name);
1716         if (session != NULL) {
1717                 ret = LTTNG_ERR_EXIST_SESS;
1718                 goto find_error;
1719         }
1720
1721         /* Create tracing session in the registry */
1722         ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1723                         LTTNG_SOCK_GET_GID_CRED(creds));
1724         if (ret != LTTNG_OK) {
1725                 goto session_error;
1726         }
1727
1728         /*
1729          * Get the newly created session pointer back
1730          *
1731          * XXX: There is no need for the session lock list here since the caller
1732          * (process_client_msg) is holding it. We might want to change that so a
1733          * single command does not lock the entire session list.
1734          */
1735         session = session_find_by_name(name);
1736         assert(session);
1737
1738         /* Create default consumer output for the session not yet created. */
1739         session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1740         if (session->consumer == NULL) {
1741                 ret = LTTNG_ERR_FATAL;
1742                 goto consumer_error;
1743         }
1744
1745         /*
1746          * This means that the lttng_create_session call was called with the _path_
1747          * argument set to NULL.
1748          */
1749         if (uris == NULL) {
1750                 /*
1751                  * At this point, we'll skip the consumer URI setup and create a
1752                  * session with a NULL path which will flag the session to NOT spawn a
1753                  * consumer.
1754                  */
1755                 DBG("Create session %s with NO uri, skipping consumer setup", name);
1756                 goto end;
1757         }
1758
1759         session->start_consumer = 1;
1760
1761         ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1762         if (ret != LTTNG_OK) {
1763                 goto consumer_error;
1764         }
1765
1766         session->consumer->enabled = 1;
1767
1768 end:
1769         return LTTNG_OK;
1770
1771 consumer_error:
1772         session_destroy(session);
1773 session_error:
1774 find_error:
1775         return ret;
1776 }
1777
1778 /*
1779  * Command LTTNG_DESTROY_SESSION processed by the client thread.
1780  */
1781 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1782 {
1783         int ret;
1784         struct ltt_ust_session *usess;
1785         struct ltt_kernel_session *ksess;
1786
1787         /* Safety net */
1788         assert(session);
1789
1790         usess = session->ust_session;
1791         ksess = session->kernel_session;
1792
1793         /* Clean kernel session teardown */
1794         kernel_destroy_session(ksess);
1795
1796         /* UST session teardown */
1797         if (usess) {
1798                 /* Close any relayd session */
1799                 consumer_output_send_destroy_relayd(usess->consumer);
1800
1801                 /* Destroy every UST application related to this session. */
1802                 ret = ust_app_destroy_trace_all(usess);
1803                 if (ret) {
1804                         ERR("Error in ust_app_destroy_trace_all");
1805                 }
1806
1807                 /* Clean up the rest. */
1808                 trace_ust_destroy_session(usess);
1809         }
1810
1811         /*
1812          * Must notify the kernel thread here to update it's poll set in order to
1813          * remove the channel(s)' fd just destroyed.
1814          */
1815         ret = notify_thread_pipe(wpipe);
1816         if (ret < 0) {
1817                 PERROR("write kernel poll pipe");
1818         }
1819
1820         ret = session_destroy(session);
1821
1822         return ret;
1823 }
1824
1825 /*
1826  * Command LTTNG_CALIBRATE processed by the client thread.
1827  */
1828 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1829 {
1830         int ret;
1831
1832         switch (domain) {
1833         case LTTNG_DOMAIN_KERNEL:
1834         {
1835                 struct lttng_kernel_calibrate kcalibrate;
1836
1837                 kcalibrate.type = calibrate->type;
1838                 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1839                 if (ret < 0) {
1840                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1841                         goto error;
1842                 }
1843                 break;
1844         }
1845         case LTTNG_DOMAIN_UST:
1846         {
1847                 struct lttng_ust_calibrate ucalibrate;
1848
1849                 ucalibrate.type = calibrate->type;
1850                 ret = ust_app_calibrate_glb(&ucalibrate);
1851                 if (ret < 0) {
1852                         ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
1853                         goto error;
1854                 }
1855                 break;
1856         }
1857         default:
1858                 ret = LTTNG_ERR_UND;
1859                 goto error;
1860         }
1861
1862         ret = LTTNG_OK;
1863
1864 error:
1865         return ret;
1866 }
1867
1868 /*
1869  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1870  */
1871 int cmd_register_consumer(struct ltt_session *session, int domain,
1872                 const char *sock_path, struct consumer_data *cdata)
1873 {
1874         int ret, sock;
1875         struct consumer_socket *socket;
1876
1877         assert(session);
1878         assert(cdata);
1879         assert(sock_path);
1880
1881         switch (domain) {
1882         case LTTNG_DOMAIN_KERNEL:
1883         {
1884                 struct ltt_kernel_session *ksess = session->kernel_session;
1885
1886                 assert(ksess);
1887
1888                 /* Can't register a consumer if there is already one */
1889                 if (ksess->consumer_fds_sent != 0) {
1890                         ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1891                         goto error;
1892                 }
1893
1894                 sock = lttcomm_connect_unix_sock(sock_path);
1895                 if (sock < 0) {
1896                         ret = LTTNG_ERR_CONNECT_FAIL;
1897                         goto error;
1898                 }
1899
1900                 socket = consumer_allocate_socket(sock);
1901                 if (socket == NULL) {
1902                         ret = close(sock);
1903                         if (ret < 0) {
1904                                 PERROR("close register consumer");
1905                         }
1906                         ret = LTTNG_ERR_FATAL;
1907                         goto error;
1908                 }
1909
1910                 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1911                 if (socket->lock == NULL) {
1912                         PERROR("zmalloc pthread mutex");
1913                         ret = LTTNG_ERR_FATAL;
1914                         goto error;
1915                 }
1916                 pthread_mutex_init(socket->lock, NULL);
1917                 socket->registered = 1;
1918
1919                 rcu_read_lock();
1920                 consumer_add_socket(socket, ksess->consumer);
1921                 rcu_read_unlock();
1922
1923                 pthread_mutex_lock(&cdata->pid_mutex);
1924                 cdata->pid = -1;
1925                 pthread_mutex_unlock(&cdata->pid_mutex);
1926
1927                 break;
1928         }
1929         default:
1930                 /* TODO: Userspace tracing */
1931                 ret = LTTNG_ERR_UND;
1932                 goto error;
1933         }
1934
1935         ret = LTTNG_OK;
1936
1937 error:
1938         return ret;
1939 }
1940
1941 /*
1942  * Command LTTNG_LIST_DOMAINS processed by the client thread.
1943  */
1944 ssize_t cmd_list_domains(struct ltt_session *session,
1945                 struct lttng_domain **domains)
1946 {
1947         int ret, index = 0;
1948         ssize_t nb_dom = 0;
1949
1950         if (session->kernel_session != NULL) {
1951                 DBG3("Listing domains found kernel domain");
1952                 nb_dom++;
1953         }
1954
1955         if (session->ust_session != NULL) {
1956                 DBG3("Listing domains found UST global domain");
1957                 nb_dom++;
1958         }
1959
1960         *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1961         if (*domains == NULL) {
1962                 ret = LTTNG_ERR_FATAL;
1963                 goto error;
1964         }
1965
1966         if (session->kernel_session != NULL) {
1967                 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1968                 index++;
1969         }
1970
1971         if (session->ust_session != NULL) {
1972                 (*domains)[index].type = LTTNG_DOMAIN_UST;
1973                 index++;
1974         }
1975
1976         return nb_dom;
1977
1978 error:
1979         /* Return negative value to differentiate return code */
1980         return -ret;
1981 }
1982
1983
1984 /*
1985  * Command LTTNG_LIST_CHANNELS processed by the client thread.
1986  */
1987 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
1988                 struct lttng_channel **channels)
1989 {
1990         int ret;
1991         ssize_t nb_chan = 0;
1992
1993         switch (domain) {
1994         case LTTNG_DOMAIN_KERNEL:
1995                 if (session->kernel_session != NULL) {
1996                         nb_chan = session->kernel_session->channel_count;
1997                 }
1998                 DBG3("Number of kernel channels %zd", nb_chan);
1999                 if (nb_chan <= 0) {
2000                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
2001                 }
2002                 break;
2003         case LTTNG_DOMAIN_UST:
2004                 if (session->ust_session != NULL) {
2005                         nb_chan = lttng_ht_get_count(
2006                                         session->ust_session->domain_global.channels);
2007                 }
2008                 DBG3("Number of UST global channels %zd", nb_chan);
2009                 if (nb_chan <= 0) {
2010                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2011                 }
2012                 break;
2013         default:
2014                 *channels = NULL;
2015                 ret = LTTNG_ERR_UND;
2016                 goto error;
2017         }
2018
2019         if (nb_chan > 0) {
2020                 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2021                 if (*channels == NULL) {
2022                         ret = LTTNG_ERR_FATAL;
2023                         goto error;
2024                 }
2025
2026                 list_lttng_channels(domain, session, *channels);
2027         } else {
2028                 *channels = NULL;
2029                 /* Ret value was set in the domain switch case */
2030                 goto error;
2031         }
2032
2033         return nb_chan;
2034
2035 error:
2036         /* Return negative value to differentiate return code */
2037         return -ret;
2038 }
2039
2040 /*
2041  * Command LTTNG_LIST_EVENTS processed by the client thread.
2042  */
2043 ssize_t cmd_list_events(int domain, struct ltt_session *session,
2044                 char *channel_name, struct lttng_event **events)
2045 {
2046         int ret = 0;
2047         ssize_t nb_event = 0;
2048
2049         switch (domain) {
2050         case LTTNG_DOMAIN_KERNEL:
2051                 if (session->kernel_session != NULL) {
2052                         nb_event = list_lttng_kernel_events(channel_name,
2053                                         session->kernel_session, events);
2054                 }
2055                 break;
2056         case LTTNG_DOMAIN_UST:
2057         {
2058                 if (session->ust_session != NULL) {
2059                         nb_event = list_lttng_ust_global_events(channel_name,
2060                                         &session->ust_session->domain_global, events);
2061                 }
2062                 break;
2063         }
2064         default:
2065                 ret = LTTNG_ERR_UND;
2066                 goto error;
2067         }
2068
2069         return nb_event;
2070
2071 error:
2072         /* Return negative value to differentiate return code */
2073         return -ret;
2074 }
2075
2076 /*
2077  * Using the session list, filled a lttng_session array to send back to the
2078  * client for session listing.
2079  *
2080  * The session list lock MUST be acquired before calling this function. Use
2081  * session_lock_list() and session_unlock_list().
2082  */
2083 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2084                 gid_t gid)
2085 {
2086         int ret;
2087         unsigned int i = 0;
2088         struct ltt_session *session;
2089         struct ltt_session_list *list = session_get_list();
2090
2091         DBG("Getting all available session for UID %d GID %d",
2092                         uid, gid);
2093         /*
2094          * Iterate over session list and append data after the control struct in
2095          * the buffer.
2096          */
2097         cds_list_for_each_entry(session, &list->head, list) {
2098                 /*
2099                  * Only list the sessions the user can control.
2100                  */
2101                 if (!session_access_ok(session, uid, gid)) {
2102                         continue;
2103                 }
2104
2105                 struct ltt_kernel_session *ksess = session->kernel_session;
2106                 struct ltt_ust_session *usess = session->ust_session;
2107
2108                 if (session->consumer->type == CONSUMER_DST_NET ||
2109                                 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2110                                 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2111                         ret = build_network_session_path(sessions[i].path,
2112                                         sizeof(session[i].path), session);
2113                 } else {
2114                         ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2115                                         session->consumer->dst.trace_path);
2116                 }
2117                 if (ret < 0) {
2118                         PERROR("snprintf session path");
2119                         continue;
2120                 }
2121
2122                 strncpy(sessions[i].name, session->name, NAME_MAX);
2123                 sessions[i].name[NAME_MAX - 1] = '\0';
2124                 sessions[i].enabled = session->enabled;
2125                 i++;
2126         }
2127 }
2128
2129 /*
2130  * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2131  */
2132 int cmd_disable_consumer(int domain, struct ltt_session *session)
2133 {
2134         int ret;
2135         struct ltt_kernel_session *ksess = session->kernel_session;
2136         struct ltt_ust_session *usess = session->ust_session;
2137         struct consumer_output *consumer;
2138
2139         assert(session);
2140
2141         if (session->enabled) {
2142                 /* Can't disable consumer on an already started session */
2143                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2144                 goto error;
2145         }
2146
2147         if (!session->start_consumer) {
2148                 ret = LTTNG_ERR_NO_CONSUMER;
2149                 goto error;
2150         }
2151
2152         switch (domain) {
2153         case 0:
2154                 DBG("Disable tracing session %s consumer", session->name);
2155                 consumer = session->consumer;
2156                 break;
2157         case LTTNG_DOMAIN_KERNEL:
2158                 /* Code flow error if we don't have a kernel session here. */
2159                 assert(ksess);
2160
2161                 DBG("Disabling kernel consumer");
2162                 consumer = ksess->consumer;
2163
2164                 break;
2165         case LTTNG_DOMAIN_UST:
2166                 /* Code flow error if we don't have a UST session here. */
2167                 assert(usess);
2168
2169                 DBG("Disabling UST consumer");
2170                 consumer = usess->consumer;
2171
2172                 break;
2173         default:
2174                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
2175                 goto error;
2176         }
2177
2178         if (consumer) {
2179                 consumer->enabled = 0;
2180                 /* Success at this point */
2181                 ret = LTTNG_OK;
2182         } else {
2183                 ret = LTTNG_ERR_NO_CONSUMER;
2184         }
2185
2186 error:
2187         return ret;
2188 }
2189
2190 /*
2191  * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2192  */
2193 int cmd_enable_consumer(int domain, struct ltt_session *session)
2194 {
2195         int ret;
2196         struct ltt_kernel_session *ksess = session->kernel_session;
2197         struct ltt_ust_session *usess = session->ust_session;
2198         struct consumer_output *consumer = NULL;
2199
2200         assert(session);
2201
2202         /* Can't enable consumer after session started. */
2203         if (session->enabled) {
2204                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2205                 goto error;
2206         }
2207
2208         switch (domain) {
2209         case 0:
2210                 assert(session->consumer);
2211                 consumer = session->consumer;
2212                 break;
2213         case LTTNG_DOMAIN_KERNEL:
2214                 /* Code flow error if we don't have a kernel session here. */
2215                 assert(ksess);
2216
2217                 /*
2218                  * Check if we have already sent fds to the consumer. In that case,
2219                  * the enable-consumer command can't be used because a start trace
2220                  * had previously occured.
2221                  */
2222                 if (ksess->consumer_fds_sent) {
2223                         ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2224                         goto error;
2225                 }
2226
2227                 consumer = ksess->tmp_consumer;
2228                 if (consumer == NULL) {
2229                         ret = LTTNG_OK;
2230                         /* No temp. consumer output exists. Using the current one. */
2231                         DBG3("No temporary consumer. Using default");
2232                         consumer = ksess->consumer;
2233                         goto error;
2234                 }
2235
2236                 switch (consumer->type) {
2237                 case CONSUMER_DST_LOCAL:
2238                         DBG2("Consumer output is local. Creating directory(ies)");
2239
2240                         /* Create directory(ies) */
2241                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2242                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2243                         if (ret < 0) {
2244                                 if (ret != -EEXIST) {
2245                                         ERR("Trace directory creation error");
2246                                         ret = LTTNG_ERR_FATAL;
2247                                         goto error;
2248                                 }
2249                         }
2250                         break;
2251                 case CONSUMER_DST_NET:
2252                         DBG2("Consumer output is network. Validating URIs");
2253                         /* Validate if we have both control and data path set. */
2254                         if (!consumer->dst.net.control_isset) {
2255                                 ret = LTTNG_ERR_URL_CTRL_MISS;
2256                                 goto error;
2257                         }
2258
2259                         if (!consumer->dst.net.data_isset) {
2260                                 ret = LTTNG_ERR_URL_DATA_MISS;
2261                                 goto error;
2262                         }
2263
2264                         /* Check established network session state */
2265                         if (session->net_handle == 0) {
2266                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2267                                 ERR("Session network handle is not set on enable-consumer");
2268                                 goto error;
2269                         }
2270
2271                         break;
2272                 }
2273
2274                 /*
2275                  * @session-lock
2276                  * This is race free for now since the session lock is acquired before
2277                  * ending up in this function. No other threads can access this kernel
2278                  * session without this lock hence freeing the consumer output object
2279                  * is valid.
2280                  */
2281                 rcu_read_lock();
2282                 /* Destroy current consumer. We are about to replace it */
2283                 consumer_destroy_output(ksess->consumer);
2284                 rcu_read_unlock();
2285                 ksess->consumer = consumer;
2286                 ksess->tmp_consumer = NULL;
2287
2288                 break;
2289         case LTTNG_DOMAIN_UST:
2290                 /* Code flow error if we don't have a UST session here. */
2291                 assert(usess);
2292
2293                 /*
2294                  * Check if we have already sent fds to the consumer. In that case,
2295                  * the enable-consumer command can't be used because a start trace
2296                  * had previously occured.
2297                  */
2298                 if (usess->start_trace) {
2299                         ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2300                         goto error;
2301                 }
2302
2303                 consumer = usess->tmp_consumer;
2304                 if (consumer == NULL) {
2305                         ret = LTTNG_OK;
2306                         /* No temp. consumer output exists. Using the current one. */
2307                         DBG3("No temporary consumer. Using default");
2308                         consumer = usess->consumer;
2309                         goto error;
2310                 }
2311
2312                 switch (consumer->type) {
2313                 case CONSUMER_DST_LOCAL:
2314                         DBG2("Consumer output is local. Creating directory(ies)");
2315
2316                         /* Create directory(ies) */
2317                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2318                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2319                         if (ret < 0) {
2320                                 if (ret != -EEXIST) {
2321                                         ERR("Trace directory creation error");
2322                                         ret = LTTNG_ERR_FATAL;
2323                                         goto error;
2324                                 }
2325                         }
2326                         break;
2327                 case CONSUMER_DST_NET:
2328                         DBG2("Consumer output is network. Validating URIs");
2329                         /* Validate if we have both control and data path set. */
2330                         if (!consumer->dst.net.control_isset) {
2331                                 ret = LTTNG_ERR_URL_CTRL_MISS;
2332                                 goto error;
2333                         }
2334
2335                         if (!consumer->dst.net.data_isset) {
2336                                 ret = LTTNG_ERR_URL_DATA_MISS;
2337                                 goto error;
2338                         }
2339
2340                         /* Check established network session state */
2341                         if (session->net_handle == 0) {
2342                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2343                                 DBG2("Session network handle is not set on enable-consumer");
2344                                 goto error;
2345                         }
2346
2347                         if (consumer->net_seq_index == -1) {
2348                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2349                                 DBG2("Network index is not set on the consumer");
2350                                 goto error;
2351                         }
2352
2353                         break;
2354                 }
2355
2356                 /*
2357                  * @session-lock
2358                  * This is race free for now since the session lock is acquired before
2359                  * ending up in this function. No other threads can access this kernel
2360                  * session without this lock hence freeing the consumer output object
2361                  * is valid.
2362                  */
2363                 rcu_read_lock();
2364                 /* Destroy current consumer. We are about to replace it */
2365                 consumer_destroy_output(usess->consumer);
2366                 rcu_read_unlock();
2367                 usess->consumer = consumer;
2368                 usess->tmp_consumer = NULL;
2369
2370                 break;
2371         }
2372
2373         session->start_consumer = 1;
2374
2375         /* Enable it */
2376         if (consumer) {
2377                 consumer->enabled = 1;
2378                 /* Success at this point */
2379                 ret = LTTNG_OK;
2380         } else {
2381                 /* Should not really happend... */
2382                 ret = LTTNG_ERR_NO_CONSUMER;
2383         }
2384
2385 error:
2386         return ret;
2387 }
2388
2389 /*
2390  * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
2391  * ready for trace analysis (or anykind of reader) or else 1 for pending data.
2392  */
2393 int cmd_data_pending(struct ltt_session *session)
2394 {
2395         int ret;
2396         struct ltt_kernel_session *ksess = session->kernel_session;
2397         struct ltt_ust_session *usess = session->ust_session;
2398
2399         assert(session);
2400
2401         /* Session MUST be stopped to ask for data availability. */
2402         if (session->enabled) {
2403                 ret = LTTNG_ERR_SESSION_STARTED;
2404                 goto error;
2405         }
2406
2407         if (ksess && ksess->consumer) {
2408                 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
2409                 if (ret == 1) {
2410                         /* Data is still being extracted for the kernel. */
2411                         goto error;
2412                 }
2413         }
2414
2415         if (usess && usess->consumer) {
2416                 ret = consumer_is_data_pending(usess->id, usess->consumer);
2417                 if (ret == 1) {
2418                         /* Data is still being extracted for the kernel. */
2419                         goto error;
2420                 }
2421         }
2422
2423         /* Data is ready to be read by a viewer */
2424         ret = 0;
2425
2426 error:
2427         return ret;
2428 }
2429
2430 /*
2431  * Init command subsystem.
2432  */
2433 void cmd_init(void)
2434 {
2435         /*
2436          * Set network sequence index to 1 for streams to match a relayd socket on
2437          * the consumer side.
2438          */
2439         uatomic_set(&relayd_net_seq_idx, 1);
2440
2441         DBG("Command subsystem initialized");
2442 }