src/bin/lttng-sessiond/cmd.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <assert.h>
  20 #include <urcu/list.h>
  21 #include <urcu/uatomic.h>
  22
  23 #include <common/defaults.h>
  24 #include <common/common.h>
  25 #include <common/sessiond-comm/sessiond-comm.h>
  26 #include <common/relayd/relayd.h>
  27
  28 #include "channel.h"
  29 #include "consumer.h"
  30 #include "event.h"
  31 #include "kernel.h"
  32 #include "kernel-consumer.h"
  33 #include "lttng-sessiond.h"
  34 #include "utils.h"
  35
  36 #include "cmd.h"
  37
  38 /*
  39  * Used to keep a unique index for each relayd socket created where this value
  40  * is associated with streams on the consumer so it can match the right relayd
  41  * to send to.
  42  *
  43  * This value should be incremented atomically for safety purposes and future
  44  * possible concurrent access.
  45  */
  46 static unsigned int relayd_net_seq_idx;
  47
  48 /*
  49  * Create a session path used by list_lttng_sessions for the case that the
  50  * session consumer is on the network.
  51  */
  52 static int build_network_session_path(char *dst, size_t size,
  53                 struct ltt_session *session)
  54 {
  55         int ret, kdata_port, udata_port;
  56         struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
  57         char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
  58
  59         assert(session);
  60         assert(dst);
  61
  62         memset(tmp_urls, 0, sizeof(tmp_urls));
  63         memset(tmp_uurl, 0, sizeof(tmp_uurl));
  64
  65         kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
  66
  67         if (session->kernel_session && session->kernel_session->consumer) {
  68                 kuri = &session->kernel_session->consumer->dst.net.control;
  69                 kdata_port = session->kernel_session->consumer->dst.net.data.port;
  70         }
  71
  72         if (session->ust_session && session->ust_session->consumer) {
  73                 uuri = &session->ust_session->consumer->dst.net.control;
  74                 udata_port = session->ust_session->consumer->dst.net.data.port;
  75         }
  76
  77         if (uuri == NULL && kuri == NULL) {
  78                 uri = &session->consumer->dst.net.control;
  79                 kdata_port = session->consumer->dst.net.data.port;
  80         } else if (kuri && uuri) {
  81                 ret = uri_compare(kuri, uuri);
  82                 if (ret) {
  83                         /* Not Equal */
  84                         uri = kuri;
  85                         /* Build uuri URL string */
  86                         ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
  87                         if (ret < 0) {
  88                                 goto error;
  89                         }
  90                 } else {
  91                         uri = kuri;
  92                 }
  93         } else if (kuri && uuri == NULL) {
  94                 uri = kuri;
  95         } else if (uuri && kuri == NULL) {
  96                 uri = uuri;
  97         }
  98
  99         ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
 100         if (ret < 0) {
 101                 goto error;
 102         }
 103
 104         /*
 105          * Do we have a UST url set. If yes, this means we have both kernel and UST
 106          * to print.
 107          */
 108         if (strlen(tmp_uurl) > 0) {
 109                 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
 110                                 tmp_urls, kdata_port, tmp_uurl, udata_port);
 111         } else {
 112                 int dport;
 113                 if (kuri) {
 114                         dport = kdata_port;
 115                 } else {
 116                         /* No kernel URI, use the UST port. */
 117                         dport = udata_port;
 118                 }
 119                 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
 120         }
 121
 122 error:
 123         return ret;
 124 }
 125
 126 /*
 127  * Fill lttng_channel array of all channels.
 128  */
 129 static void list_lttng_channels(int domain, struct ltt_session *session,
 130                 struct lttng_channel *channels)
 131 {
 132         int i = 0;
 133         struct ltt_kernel_channel *kchan;
 134
 135         DBG("Listing channels for session %s", session->name);
 136
 137         switch (domain) {
 138         case LTTNG_DOMAIN_KERNEL:
 139                 /* Kernel channels */
 140                 if (session->kernel_session != NULL) {
 141                         cds_list_for_each_entry(kchan,
 142                                         &session->kernel_session->channel_list.head, list) {
 143                                 /* Copy lttng_channel struct to array */
 144                                 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
 145                                 channels[i].enabled = kchan->enabled;
 146                                 i++;
 147                         }
 148                 }
 149                 break;
 150         case LTTNG_DOMAIN_UST:
 151         {
 152                 struct lttng_ht_iter iter;
 153                 struct ltt_ust_channel *uchan;
 154
 155                 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
 156                                 &iter.iter, uchan, node.node) {
 157                         strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
 158                         channels[i].attr.overwrite = uchan->attr.overwrite;
 159                         channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
 160                         channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
 161                         channels[i].attr.switch_timer_interval =
 162                                 uchan->attr.switch_timer_interval;
 163                         channels[i].attr.read_timer_interval =
 164                                 uchan->attr.read_timer_interval;
 165                         channels[i].enabled = uchan->enabled;
 166                         switch (uchan->attr.output) {
 167                         case LTTNG_UST_MMAP:
 168                         default:
 169                                 channels[i].attr.output = LTTNG_EVENT_MMAP;
 170                                 break;
 171                         }
 172                         i++;
 173                 }
 174                 break;
 175         }
 176         default:
 177                 break;
 178         }
 179 }
 180
 181 /*
 182  * Create a list of ust global domain events.
 183  */
 184 static int list_lttng_ust_global_events(char *channel_name,
 185                 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
 186 {
 187         int i = 0, ret = 0;
 188         unsigned int nb_event = 0;
 189         struct lttng_ht_iter iter;
 190         struct lttng_ht_node_str *node;
 191         struct ltt_ust_channel *uchan;
 192         struct ltt_ust_event *uevent;
 193         struct lttng_event *tmp;
 194
 195         DBG("Listing UST global events for channel %s", channel_name);
 196
 197         rcu_read_lock();
 198
 199         lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
 200         node = lttng_ht_iter_get_node_str(&iter);
 201         if (node == NULL) {
 202                 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 203                 goto error;
 204         }
 205
 206         uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
 207
 208         nb_event += lttng_ht_get_count(uchan->events);
 209
 210         if (nb_event == 0) {
 211                 ret = nb_event;
 212                 goto error;
 213         }
 214
 215         DBG3("Listing UST global %d events", nb_event);
 216
 217         tmp = zmalloc(nb_event * sizeof(struct lttng_event));
 218         if (tmp == NULL) {
 219                 ret = LTTNG_ERR_FATAL;
 220                 goto error;
 221         }
 222
 223         cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
 224                 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
 225                 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 226                 tmp[i].enabled = uevent->enabled;
 227
 228                 switch (uevent->attr.instrumentation) {
 229                 case LTTNG_UST_TRACEPOINT:
 230                         tmp[i].type = LTTNG_EVENT_TRACEPOINT;
 231                         break;
 232                 case LTTNG_UST_PROBE:
 233                         tmp[i].type = LTTNG_EVENT_PROBE;
 234                         break;
 235                 case LTTNG_UST_FUNCTION:
 236                         tmp[i].type = LTTNG_EVENT_FUNCTION;
 237                         break;
 238                 }
 239
 240                 tmp[i].loglevel = uevent->attr.loglevel;
 241                 switch (uevent->attr.loglevel_type) {
 242                 case LTTNG_UST_LOGLEVEL_ALL:
 243                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 244                         break;
 245                 case LTTNG_UST_LOGLEVEL_RANGE:
 246                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 247                         break;
 248                 case LTTNG_UST_LOGLEVEL_SINGLE:
 249                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 250                         break;
 251                 }
 252                 if (uevent->filter) {
 253                         tmp[i].filter = 1;
 254                 }
 255                 i++;
 256         }
 257
 258         ret = nb_event;
 259         *events = tmp;
 260
 261 error:
 262         rcu_read_unlock();
 263         return ret;
 264 }
 265
 266 /*
 267  * Fill lttng_event array of all kernel events in the channel.
 268  */
 269 static int list_lttng_kernel_events(char *channel_name,
 270                 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
 271 {
 272         int i = 0, ret;
 273         unsigned int nb_event;
 274         struct ltt_kernel_event *event;
 275         struct ltt_kernel_channel *kchan;
 276
 277         kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
 278         if (kchan == NULL) {
 279                 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 280                 goto error;
 281         }
 282
 283         nb_event = kchan->event_count;
 284
 285         DBG("Listing events for channel %s", kchan->channel->name);
 286
 287         if (nb_event == 0) {
 288                 goto end;
 289         }
 290
 291         *events = zmalloc(nb_event * sizeof(struct lttng_event));
 292         if (*events == NULL) {
 293                 ret = LTTNG_ERR_FATAL;
 294                 goto error;
 295         }
 296
 297         /* Kernel channels */
 298         cds_list_for_each_entry(event, &kchan->events_list.head , list) {
 299                 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
 300                 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 301                 (*events)[i].enabled = event->enabled;
 302
 303                 switch (event->event->instrumentation) {
 304                 case LTTNG_KERNEL_TRACEPOINT:
 305                         (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
 306                         break;
 307                 case LTTNG_KERNEL_KPROBE:
 308                 case LTTNG_KERNEL_KRETPROBE:
 309                         (*events)[i].type = LTTNG_EVENT_PROBE;
 310                         memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
 311                                         sizeof(struct lttng_kernel_kprobe));
 312                         break;
 313                 case LTTNG_KERNEL_FUNCTION:
 314                         (*events)[i].type = LTTNG_EVENT_FUNCTION;
 315                         memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
 316                                         sizeof(struct lttng_kernel_function));
 317                         break;
 318                 case LTTNG_KERNEL_NOOP:
 319                         (*events)[i].type = LTTNG_EVENT_NOOP;
 320                         break;
 321                 case LTTNG_KERNEL_SYSCALL:
 322                         (*events)[i].type = LTTNG_EVENT_SYSCALL;
 323                         break;
 324                 case LTTNG_KERNEL_ALL:
 325                         assert(0);
 326                         break;
 327                 }
 328                 i++;
 329         }
 330
 331 end:
 332         return nb_event;
 333
 334 error:
 335         /* Negate the error code to differentiate the size from an error */
 336         return -ret;
 337 }
 338
 339 /*
 340  * Add URI so the consumer output object. Set the correct path depending on the
 341  * domain adding the default trace directory.
 342  */
 343 static int add_uri_to_consumer(struct consumer_output *consumer,
 344                 struct lttng_uri *uri, int domain, const char *session_name)
 345 {
 346         int ret = LTTNG_OK;
 347         const char *default_trace_dir;
 348
 349         assert(uri);
 350
 351         if (consumer == NULL) {
 352                 DBG("No consumer detected. Don't add URI. Stopping.");
 353                 ret = LTTNG_ERR_NO_CONSUMER;
 354                 goto error;
 355         }
 356
 357         switch (domain) {
 358         case LTTNG_DOMAIN_KERNEL:
 359                 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
 360                 break;
 361         case LTTNG_DOMAIN_UST:
 362                 default_trace_dir = DEFAULT_UST_TRACE_DIR;
 363                 break;
 364         default:
 365                 /*
 366                  * This case is possible is we try to add the URI to the global tracing
 367                  * session consumer object which in this case there is no subdir.
 368                  */
 369                 default_trace_dir = "";
 370         }
 371
 372         switch (uri->dtype) {
 373         case LTTNG_DST_IPV4:
 374         case LTTNG_DST_IPV6:
 375                 DBG2("Setting network URI to consumer");
 376
 377                 /* Set URI into consumer output object */
 378                 ret = consumer_set_network_uri(consumer, uri);
 379                 if (ret < 0) {
 380                         ret = LTTNG_ERR_FATAL;
 381                         goto error;
 382                 } else if (ret == 1) {
 383                         /*
 384                          * URI was the same in the consumer so we do not append the subdir
 385                          * again so to not duplicate output dir.
 386                          */
 387                         goto error;
 388                 }
 389
 390                 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
 391                         ret = consumer_set_subdir(consumer, session_name);
 392                         if (ret < 0) {
 393                                 ret = LTTNG_ERR_FATAL;
 394                                 goto error;
 395                         }
 396                 }
 397
 398                 if (uri->stype == LTTNG_STREAM_CONTROL) {
 399                         /* On a new subdir, reappend the default trace dir. */
 400                         strncat(consumer->subdir, default_trace_dir,
 401                                         sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
 402                         DBG3("Append domain trace name to subdir %s", consumer->subdir);
 403                 }
 404
 405                 break;
 406         case LTTNG_DST_PATH:
 407                 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
 408                 memset(consumer->dst.trace_path, 0,
 409                                 sizeof(consumer->dst.trace_path));
 410                 strncpy(consumer->dst.trace_path, uri->dst.path,
 411                                 sizeof(consumer->dst.trace_path));
 412                 /* Append default trace dir */
 413                 strncat(consumer->dst.trace_path, default_trace_dir,
 414                                 sizeof(consumer->dst.trace_path) -
 415                                 strlen(consumer->dst.trace_path) - 1);
 416                 /* Flag consumer as local. */
 417                 consumer->type = CONSUMER_DST_LOCAL;
 418                 break;
 419         }
 420
 421 error:
 422         return ret;
 423 }
 424
 425 /*
 426  * Init tracing by creating trace directory and sending fds kernel consumer.
 427  */
 428 static int init_kernel_tracing(struct ltt_kernel_session *session)
 429 {
 430         int ret = 0;
 431         struct lttng_ht_iter iter;
 432         struct consumer_socket *socket;
 433
 434         assert(session);
 435
 436         if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
 437                 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
 438                                 socket, node.node) {
 439                         /* Code flow error */
 440                         assert(socket->fd >= 0);
 441
 442                         pthread_mutex_lock(socket->lock);
 443                         ret = kernel_consumer_send_session(socket->fd, session);
 444                         pthread_mutex_unlock(socket->lock);
 445                         if (ret < 0) {
 446                                 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 447                                 goto error;
 448                         }
 449                 }
 450         }
 451
 452 error:
 453         return ret;
 454 }
 455
 456 /*
 457  * Create a socket to the relayd using the URI.
 458  *
 459  * On success, the relayd_sock pointer is set to the created socket.
 460  * Else, it's stays untouched and a lttcomm error code is returned.
 461  */
 462 static int create_connect_relayd(struct consumer_output *output,
 463                 const char *session_name, struct lttng_uri *uri,
 464                 struct lttcomm_sock **relayd_sock)
 465 {
 466         int ret;
 467         struct lttcomm_sock *sock;
 468
 469         /* Create socket object from URI */
 470         sock = lttcomm_alloc_sock_from_uri(uri);
 471         if (sock == NULL) {
 472                 ret = LTTNG_ERR_FATAL;
 473                 goto error;
 474         }
 475
 476         ret = lttcomm_create_sock(sock);
 477         if (ret < 0) {
 478                 ret = LTTNG_ERR_FATAL;
 479                 goto error;
 480         }
 481
 482         /* Connect to relayd so we can proceed with a session creation. */
 483         ret = relayd_connect(sock);
 484         if (ret < 0) {
 485                 ERR("Unable to reach lttng-relayd");
 486                 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
 487                 goto free_sock;
 488         }
 489
 490         /* Create socket for control stream. */
 491         if (uri->stype == LTTNG_STREAM_CONTROL) {
 492                 DBG3("Creating relayd stream socket from URI");
 493
 494                 /* Check relayd version */
 495                 ret = relayd_version_check(sock, RELAYD_VERSION_COMM_MAJOR,
 496                                 RELAYD_VERSION_COMM_MINOR);
 497                 if (ret < 0) {
 498                         ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
 499                         goto close_sock;
 500                 }
 501         } else if (uri->stype == LTTNG_STREAM_DATA) {
 502                 DBG3("Creating relayd data socket from URI");
 503         } else {
 504                 /* Command is not valid */
 505                 ERR("Relayd invalid stream type: %d", uri->stype);
 506                 ret = LTTNG_ERR_INVALID;
 507                 goto close_sock;
 508         }
 509
 510         *relayd_sock = sock;
 511
 512         return LTTNG_OK;
 513
 514 close_sock:
 515         if (sock) {
 516                 (void) relayd_close(sock);
 517         }
 518 free_sock:
 519         if (sock) {
 520                 lttcomm_destroy_sock(sock);
 521         }
 522 error:
 523         return ret;
 524 }
 525
 526 /*
 527  * Connect to the relayd using URI and send the socket to the right consumer.
 528  */
 529 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
 530                 struct lttng_uri *relayd_uri, struct consumer_output *consumer,
 531                 int consumer_fd)
 532 {
 533         int ret;
 534         struct lttcomm_sock *sock = NULL;
 535
 536         /* Set the network sequence index if not set. */
 537         if (consumer->net_seq_index == -1) {
 538                 /*
 539                  * Increment net_seq_idx because we are about to transfer the
 540                  * new relayd socket to the consumer.
 541                  */
 542                 uatomic_inc(&relayd_net_seq_idx);
 543                 /* Assign unique key so the consumer can match streams */
 544                 uatomic_set(&consumer->net_seq_index,
 545                                 uatomic_read(&relayd_net_seq_idx));
 546         }
 547
 548         /* Connect to relayd and make version check if uri is the control. */
 549         ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
 550         if (ret != LTTNG_OK) {
 551                 goto close_sock;
 552         }
 553
 554         /* If the control socket is connected, network session is ready */
 555         if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
 556                 session->net_handle = 1;
 557         }
 558
 559         /* Send relayd socket to consumer. */
 560         ret = consumer_send_relayd_socket(consumer_fd, sock,
 561                         consumer, relayd_uri->stype);
 562         if (ret < 0) {
 563                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
 564                 goto close_sock;
 565         }
 566
 567         /* Flag that the corresponding socket was sent. */
 568         if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
 569                 consumer->dst.net.control_sock_sent = 1;
 570         } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
 571                 consumer->dst.net.data_sock_sent = 1;
 572         }
 573
 574         ret = LTTNG_OK;
 575
 576         /*
 577          * Close socket which was dup on the consumer side. The session daemon does
 578          * NOT keep track of the relayd socket(s) once transfer to the consumer.
 579          */
 580
 581 close_sock:
 582         if (sock) {
 583                 (void) relayd_close(sock);
 584                 lttcomm_destroy_sock(sock);
 585         }
 586
 587         return ret;
 588 }
 589
 590 /*
 591  * Send both relayd sockets to a specific consumer and domain.  This is a
 592  * helper function to facilitate sending the information to the consumer for a
 593  * session.
 594  */
 595 static int send_consumer_relayd_sockets(int domain,
 596                 struct ltt_session *session, struct consumer_output *consumer, int fd)
 597 {
 598         int ret = LTTNG_OK;
 599
 600         assert(session);
 601         assert(consumer);
 602
 603         /* Sending control relayd socket. */
 604         if (!consumer->dst.net.control_sock_sent) {
 605                 ret = send_consumer_relayd_socket(domain, session,
 606                                 &consumer->dst.net.control, consumer, fd);
 607                 if (ret != LTTNG_OK) {
 608                         goto error;
 609                 }
 610         }
 611
 612         /* Sending data relayd socket. */
 613         if (!consumer->dst.net.data_sock_sent) {
 614                 ret = send_consumer_relayd_socket(domain, session,
 615                                 &consumer->dst.net.data, consumer, fd);
 616                 if (ret != LTTNG_OK) {
 617                         goto error;
 618                 }
 619         }
 620
 621 error:
 622         return ret;
 623 }
 624
 625 /*
 626  * Setup relayd connections for a tracing session. First creates the socket to
 627  * the relayd and send them to the right domain consumer. Consumer type MUST be
 628  * network.
 629  */
 630 static int setup_relayd(struct ltt_session *session)
 631 {
 632         int ret = LTTNG_OK;
 633         struct ltt_ust_session *usess;
 634         struct ltt_kernel_session *ksess;
 635         struct consumer_socket *socket;
 636         struct lttng_ht_iter iter;
 637
 638         assert(session);
 639
 640         usess = session->ust_session;
 641         ksess = session->kernel_session;
 642
 643         DBG2("Setting relayd for session %s", session->name);
 644
 645         if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 646                         && usess->consumer->enabled) {
 647                 /* For each consumer socket, send relayd sockets */
 648                 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
 649                                 socket, node.node) {
 650                         /* Code flow error */
 651                         assert(socket->fd >= 0);
 652
 653                         pthread_mutex_lock(socket->lock);
 654                         ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
 655                                         usess->consumer, socket->fd);
 656                         pthread_mutex_unlock(socket->lock);
 657                         if (ret != LTTNG_OK) {
 658                                 goto error;
 659                         }
 660                 }
 661         }
 662
 663         if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
 664                         && ksess->consumer->enabled) {
 665                 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
 666                                 socket, node.node) {
 667                         /* Code flow error */
 668                         assert(socket->fd >= 0);
 669
 670                         pthread_mutex_lock(socket->lock);
 671                         ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
 672                                         ksess->consumer, socket->fd);
 673                         pthread_mutex_unlock(socket->lock);
 674                         if (ret != LTTNG_OK) {
 675                                 goto error;
 676                         }
 677                 }
 678         }
 679
 680 error:
 681         return ret;
 682 }
 683
 684 /*
 685  * Start a kernel session by opening all necessary streams.
 686  */
 687 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
 688 {
 689         int ret;
 690         struct ltt_kernel_channel *kchan;
 691
 692         /* Open kernel metadata */
 693         if (ksess->metadata == NULL) {
 694                 ret = kernel_open_metadata(ksess);
 695                 if (ret < 0) {
 696                         ret = LTTNG_ERR_KERN_META_FAIL;
 697                         goto error;
 698                 }
 699         }
 700
 701         /* Open kernel metadata stream */
 702         if (ksess->metadata_stream_fd < 0) {
 703                 ret = kernel_open_metadata_stream(ksess);
 704                 if (ret < 0) {
 705                         ERR("Kernel create metadata stream failed");
 706                         ret = LTTNG_ERR_KERN_STREAM_FAIL;
 707                         goto error;
 708                 }
 709         }
 710
 711         /* For each channel */
 712         cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
 713                 if (kchan->stream_count == 0) {
 714                         ret = kernel_open_channel_stream(kchan);
 715                         if (ret < 0) {
 716                                 ret = LTTNG_ERR_KERN_STREAM_FAIL;
 717                                 goto error;
 718                         }
 719                         /* Update the stream global counter */
 720                         ksess->stream_count_global += ret;
 721                 }
 722         }
 723
 724         /* Setup kernel consumer socket and send fds to it */
 725         ret = init_kernel_tracing(ksess);
 726         if (ret < 0) {
 727                 ret = LTTNG_ERR_KERN_START_FAIL;
 728                 goto error;
 729         }
 730
 731         /* This start the kernel tracing */
 732         ret = kernel_start_session(ksess);
 733         if (ret < 0) {
 734                 ret = LTTNG_ERR_KERN_START_FAIL;
 735                 goto error;
 736         }
 737
 738         /* Quiescent wait after starting trace */
 739         kernel_wait_quiescent(kernel_tracer_fd);
 740
 741         ksess->started = 1;
 742
 743         ret = LTTNG_OK;
 744
 745 error:
 746         return ret;
 747 }
 748
 749 /*
 750  * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
 751  */
 752 int cmd_disable_channel(struct ltt_session *session, int domain,
 753                 char *channel_name)
 754 {
 755         int ret;
 756         struct ltt_ust_session *usess;
 757
 758         usess = session->ust_session;
 759
 760         switch (domain) {
 761         case LTTNG_DOMAIN_KERNEL:
 762         {
 763                 ret = channel_kernel_disable(session->kernel_session,
 764                                 channel_name);
 765                 if (ret != LTTNG_OK) {
 766                         goto error;
 767                 }
 768
 769                 kernel_wait_quiescent(kernel_tracer_fd);
 770                 break;
 771         }
 772         case LTTNG_DOMAIN_UST:
 773         {
 774                 struct ltt_ust_channel *uchan;
 775                 struct lttng_ht *chan_ht;
 776
 777                 chan_ht = usess->domain_global.channels;
 778
 779                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 780                 if (uchan == NULL) {
 781                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 782                         goto error;
 783                 }
 784
 785                 ret = channel_ust_disable(usess, domain, uchan);
 786                 if (ret != LTTNG_OK) {
 787                         goto error;
 788                 }
 789                 break;
 790         }
 791 #if 0
 792         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 793         case LTTNG_DOMAIN_UST_EXEC_NAME:
 794         case LTTNG_DOMAIN_UST_PID:
 795 #endif
 796         default:
 797                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 798                 goto error;
 799         }
 800
 801         ret = LTTNG_OK;
 802
 803 error:
 804         return ret;
 805 }
 806
 807 /*
 808  * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
 809  *
 810  * The wpipe arguments is used as a notifier for the kernel thread.
 811  */
 812 int cmd_enable_channel(struct ltt_session *session,
 813                 int domain, struct lttng_channel *attr, int wpipe)
 814 {
 815         int ret;
 816         struct ltt_ust_session *usess = session->ust_session;
 817         struct lttng_ht *chan_ht;
 818
 819         assert(session);
 820         assert(attr);
 821
 822         DBG("Enabling channel %s for session %s", attr->name, session->name);
 823
 824         switch (domain) {
 825         case LTTNG_DOMAIN_KERNEL:
 826         {
 827                 struct ltt_kernel_channel *kchan;
 828
 829                 kchan = trace_kernel_get_channel_by_name(attr->name,
 830                                 session->kernel_session);
 831                 if (kchan == NULL) {
 832                         ret = channel_kernel_create(session->kernel_session, attr, wpipe);
 833                 } else {
 834                         ret = channel_kernel_enable(session->kernel_session, kchan);
 835                 }
 836
 837                 if (ret != LTTNG_OK) {
 838                         goto error;
 839                 }
 840
 841                 kernel_wait_quiescent(kernel_tracer_fd);
 842
 843                 /*
 844                  * If the session was previously started, start as well this newly
 845                  * created kernel session so the events/channels enabled *after* the
 846                  * start actually work.
 847                  */
 848                 if (session->started && !session->kernel_session->started) {
 849                         ret = start_kernel_session(session->kernel_session, wpipe);
 850                         if (ret != LTTNG_OK) {
 851                                 goto error;
 852                         }
 853                 }
 854                 break;
 855         }
 856         case LTTNG_DOMAIN_UST:
 857         {
 858                 struct ltt_ust_channel *uchan;
 859
 860                 chan_ht = usess->domain_global.channels;
 861
 862                 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
 863                 if (uchan == NULL) {
 864                         ret = channel_ust_create(usess, domain, attr);
 865                 } else {
 866                         ret = channel_ust_enable(usess, domain, uchan);
 867                 }
 868
 869                 /* Start the UST session if the session was already started. */
 870                 if (session->started && !usess->start_trace) {
 871                         ret = ust_app_start_trace_all(usess);
 872                         if (ret < 0) {
 873                                 ret = LTTNG_ERR_UST_START_FAIL;
 874                                 goto error;
 875                         }
 876                         ret = LTTNG_OK;
 877                         usess->start_trace = 1;
 878                 }
 879                 break;
 880         }
 881 #if 0
 882         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 883         case LTTNG_DOMAIN_UST_EXEC_NAME:
 884         case LTTNG_DOMAIN_UST_PID:
 885 #endif
 886         default:
 887                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 888                 goto error;
 889         }
 890
 891 error:
 892         return ret;
 893 }
 894
 895
 896 /*
 897  * Command LTTNG_DISABLE_EVENT processed by the client thread.
 898  */
 899 int cmd_disable_event(struct ltt_session *session, int domain,
 900                 char *channel_name, char *event_name)
 901 {
 902         int ret;
 903
 904         switch (domain) {
 905         case LTTNG_DOMAIN_KERNEL:
 906         {
 907                 struct ltt_kernel_channel *kchan;
 908                 struct ltt_kernel_session *ksess;
 909
 910                 ksess = session->kernel_session;
 911
 912                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 913                 if (kchan == NULL) {
 914                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 915                         goto error;
 916                 }
 917
 918                 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
 919                 if (ret != LTTNG_OK) {
 920                         goto error;
 921                 }
 922
 923                 kernel_wait_quiescent(kernel_tracer_fd);
 924                 break;
 925         }
 926         case LTTNG_DOMAIN_UST:
 927         {
 928                 struct ltt_ust_channel *uchan;
 929                 struct ltt_ust_session *usess;
 930
 931                 usess = session->ust_session;
 932
 933                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 934                                 channel_name);
 935                 if (uchan == NULL) {
 936                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 937                         goto error;
 938                 }
 939
 940                 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
 941                 if (ret != LTTNG_OK) {
 942                         goto error;
 943                 }
 944
 945                 DBG3("Disable UST event %s in channel %s completed", event_name,
 946                                 channel_name);
 947                 break;
 948         }
 949 #if 0
 950         case LTTNG_DOMAIN_UST_EXEC_NAME:
 951         case LTTNG_DOMAIN_UST_PID:
 952         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 953 #endif
 954         default:
 955                 ret = LTTNG_ERR_UND;
 956                 goto error;
 957         }
 958
 959         ret = LTTNG_OK;
 960
 961 error:
 962         return ret;
 963 }
 964
 965 /*
 966  * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
 967  */
 968 int cmd_disable_event_all(struct ltt_session *session, int domain,
 969                 char *channel_name)
 970 {
 971         int ret;
 972
 973         switch (domain) {
 974         case LTTNG_DOMAIN_KERNEL:
 975         {
 976                 struct ltt_kernel_session *ksess;
 977                 struct ltt_kernel_channel *kchan;
 978
 979                 ksess = session->kernel_session;
 980
 981                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 982                 if (kchan == NULL) {
 983                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 984                         goto error;
 985                 }
 986
 987                 ret = event_kernel_disable_all(ksess, kchan);
 988                 if (ret != LTTNG_OK) {
 989                         goto error;
 990                 }
 991
 992                 kernel_wait_quiescent(kernel_tracer_fd);
 993                 break;
 994         }
 995         case LTTNG_DOMAIN_UST:
 996         {
 997                 struct ltt_ust_session *usess;
 998                 struct ltt_ust_channel *uchan;
 999
1000                 usess = session->ust_session;
1001
1002                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1003                                 channel_name);
1004                 if (uchan == NULL) {
1005                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1006                         goto error;
1007                 }
1008
1009                 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
1010                 if (ret != 0) {
1011                         goto error;
1012                 }
1013
1014                 DBG3("Disable all UST events in channel %s completed", channel_name);
1015
1016                 break;
1017         }
1018 #if 0
1019         case LTTNG_DOMAIN_UST_EXEC_NAME:
1020         case LTTNG_DOMAIN_UST_PID:
1021         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1022 #endif
1023         default:
1024                 ret = LTTNG_ERR_UND;
1025                 goto error;
1026         }
1027
1028         ret = LTTNG_OK;
1029
1030 error:
1031         return ret;
1032 }
1033
1034 /*
1035  * Command LTTNG_ADD_CONTEXT processed by the client thread.
1036  */
1037 int cmd_add_context(struct ltt_session *session, int domain,
1038                 char *channel_name, char *event_name, struct lttng_event_context *ctx,
1039                 int kwpipe)
1040 {
1041         int ret;
1042
1043         switch (domain) {
1044         case LTTNG_DOMAIN_KERNEL:
1045                 assert(session->kernel_session);
1046
1047                 if (session->kernel_session->channel_count == 0) {
1048                         /* Create default channel */
1049                         ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1050                         if (ret != LTTNG_OK) {
1051                                 goto error;
1052                         }
1053                 }
1054
1055                 /* Add kernel context to kernel tracer */
1056                 ret = context_kernel_add(session->kernel_session, ctx,
1057                                 event_name, channel_name);
1058                 if (ret != LTTNG_OK) {
1059                         goto error;
1060                 }
1061                 break;
1062         case LTTNG_DOMAIN_UST:
1063         {
1064                 struct ltt_ust_session *usess = session->ust_session;
1065                 assert(usess);
1066
1067                 unsigned int chan_count =
1068                         lttng_ht_get_count(usess->domain_global.channels);
1069                 if (chan_count == 0) {
1070                         struct lttng_channel *attr;
1071                         /* Create default channel */
1072                         attr = channel_new_default_attr(domain);
1073                         if (attr == NULL) {
1074                                 ret = LTTNG_ERR_FATAL;
1075                                 goto error;
1076                         }
1077
1078                         ret = channel_ust_create(usess, domain, attr);
1079                         if (ret != LTTNG_OK) {
1080                                 free(attr);
1081                                 goto error;
1082                         }
1083                         free(attr);
1084                 }
1085
1086
1087                 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
1088                 if (ret != LTTNG_OK) {
1089                         goto error;
1090                 }
1091                 break;
1092         }
1093 #if 0
1094         case LTTNG_DOMAIN_UST_EXEC_NAME:
1095         case LTTNG_DOMAIN_UST_PID:
1096         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1097 #endif
1098         default:
1099                 ret = LTTNG_ERR_UND;
1100                 goto error;
1101         }
1102
1103         ret = LTTNG_OK;
1104
1105 error:
1106         return ret;
1107 }
1108
1109 /*
1110  * Command LTTNG_SET_FILTER processed by the client thread.
1111  */
1112 int cmd_set_filter(struct ltt_session *session, int domain,
1113                 char *channel_name, char *event_name,
1114                 struct lttng_filter_bytecode *bytecode)
1115 {
1116         int ret;
1117
1118         switch (domain) {
1119         case LTTNG_DOMAIN_KERNEL:
1120                 ret = LTTNG_ERR_FATAL;
1121                 break;
1122         case LTTNG_DOMAIN_UST:
1123         {
1124                 struct ltt_ust_session *usess = session->ust_session;
1125
1126                 ret = filter_ust_set(usess, domain, bytecode, event_name, channel_name);
1127                 if (ret != LTTNG_OK) {
1128                         goto error;
1129                 }
1130                 break;
1131         }
1132 #if 0
1133         case LTTNG_DOMAIN_UST_EXEC_NAME:
1134         case LTTNG_DOMAIN_UST_PID:
1135         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1136 #endif
1137         default:
1138                 ret = LTTNG_ERR_UND;
1139                 goto error;
1140         }
1141
1142         ret = LTTNG_OK;
1143
1144 error:
1145         return ret;
1146
1147 }
1148
1149
1150 /*
1151  * Command LTTNG_ENABLE_EVENT processed by the client thread.
1152  */
1153 int cmd_enable_event(struct ltt_session *session, int domain,
1154                 char *channel_name, struct lttng_event *event, int wpipe)
1155 {
1156         int ret;
1157         struct lttng_channel *attr;
1158
1159         assert(session);
1160         assert(event);
1161         assert(channel_name);
1162
1163         switch (domain) {
1164         case LTTNG_DOMAIN_KERNEL:
1165         {
1166                 struct ltt_kernel_channel *kchan;
1167
1168                 kchan = trace_kernel_get_channel_by_name(channel_name,
1169                                 session->kernel_session);
1170                 if (kchan == NULL) {
1171                         attr = channel_new_default_attr(domain);
1172                         if (attr == NULL) {
1173                                 ret = LTTNG_ERR_FATAL;
1174                                 goto error;
1175                         }
1176                         strncpy(attr->name, channel_name, sizeof(attr->name));
1177
1178                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1179                         if (ret != LTTNG_OK) {
1180                                 free(attr);
1181                                 goto error;
1182                         }
1183                         free(attr);
1184                 }
1185
1186                 /* Get the newly created kernel channel pointer */
1187                 kchan = trace_kernel_get_channel_by_name(channel_name,
1188                                 session->kernel_session);
1189                 if (kchan == NULL) {
1190                         /* This sould not happen... */
1191                         ret = LTTNG_ERR_FATAL;
1192                         goto error;
1193                 }
1194
1195                 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
1196                                 event);
1197                 if (ret != LTTNG_OK) {
1198                         goto error;
1199                 }
1200
1201                 kernel_wait_quiescent(kernel_tracer_fd);
1202                 break;
1203         }
1204         case LTTNG_DOMAIN_UST:
1205         {
1206                 struct ltt_ust_channel *uchan;
1207                 struct ltt_ust_session *usess = session->ust_session;
1208
1209                 assert(usess);
1210
1211                 /* Get channel from global UST domain */
1212                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1213                                 channel_name);
1214                 if (uchan == NULL) {
1215                         /* Create default channel */
1216                         attr = channel_new_default_attr(domain);
1217                         if (attr == NULL) {
1218                                 ret = LTTNG_ERR_FATAL;
1219                                 goto error;
1220                         }
1221                         strncpy(attr->name, channel_name, sizeof(attr->name));
1222
1223                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1224                         if (ret != LTTNG_OK) {
1225                                 free(attr);
1226                                 goto error;
1227                         }
1228                         free(attr);
1229
1230                         /* Get the newly created channel reference back */
1231                         uchan = trace_ust_find_channel_by_name(
1232                                         usess->domain_global.channels, channel_name);
1233                         assert(uchan);
1234                 }
1235
1236                 /* At this point, the session and channel exist on the tracer */
1237                 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
1238                 if (ret != LTTNG_OK) {
1239                         goto error;
1240                 }
1241                 break;
1242         }
1243 #if 0
1244         case LTTNG_DOMAIN_UST_EXEC_NAME:
1245         case LTTNG_DOMAIN_UST_PID:
1246         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1247 #endif
1248         default:
1249                 ret = LTTNG_ERR_UND;
1250                 goto error;
1251         }
1252
1253         ret = LTTNG_OK;
1254
1255 error:
1256         return ret;
1257 }
1258
1259 /*
1260  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1261  */
1262 int cmd_enable_event_all(struct ltt_session *session, int domain,
1263                 char *channel_name, int event_type, int wpipe)
1264 {
1265         int ret;
1266         struct lttng_channel *attr;
1267
1268         assert(session);
1269         assert(channel_name);
1270
1271         switch (domain) {
1272         case LTTNG_DOMAIN_KERNEL:
1273         {
1274                 struct ltt_kernel_channel *kchan;
1275
1276                 assert(session->kernel_session);
1277
1278                 kchan = trace_kernel_get_channel_by_name(channel_name,
1279                                 session->kernel_session);
1280                 if (kchan == NULL) {
1281                         /* Create default channel */
1282                         attr = channel_new_default_attr(domain);
1283                         if (attr == NULL) {
1284                                 ret = LTTNG_ERR_FATAL;
1285                                 goto error;
1286                         }
1287                         strncpy(attr->name, channel_name, sizeof(attr->name));
1288
1289                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1290                         if (ret != LTTNG_OK) {
1291                                 free(attr);
1292                                 goto error;
1293                         }
1294                         free(attr);
1295
1296                         /* Get the newly created kernel channel pointer */
1297                         kchan = trace_kernel_get_channel_by_name(channel_name,
1298                                         session->kernel_session);
1299                         assert(kchan);
1300                 }
1301
1302                 switch (event_type) {
1303                 case LTTNG_EVENT_SYSCALL:
1304                         ret = event_kernel_enable_all_syscalls(session->kernel_session,
1305                                         kchan, kernel_tracer_fd);
1306                         break;
1307                 case LTTNG_EVENT_TRACEPOINT:
1308                         /*
1309                          * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1310                          * events already registered to the channel.
1311                          */
1312                         ret = event_kernel_enable_all_tracepoints(session->kernel_session,
1313                                         kchan, kernel_tracer_fd);
1314                         break;
1315                 case LTTNG_EVENT_ALL:
1316                         /* Enable syscalls and tracepoints */
1317                         ret = event_kernel_enable_all(session->kernel_session,
1318                                         kchan, kernel_tracer_fd);
1319                         break;
1320                 default:
1321                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1322                         goto error;
1323                 }
1324
1325                 /* Manage return value */
1326                 if (ret != LTTNG_OK) {
1327                         goto error;
1328                 }
1329
1330                 kernel_wait_quiescent(kernel_tracer_fd);
1331                 break;
1332         }
1333         case LTTNG_DOMAIN_UST:
1334         {
1335                 struct ltt_ust_channel *uchan;
1336                 struct ltt_ust_session *usess = session->ust_session;
1337
1338                 assert(usess);
1339
1340                 /* Get channel from global UST domain */
1341                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1342                                 channel_name);
1343                 if (uchan == NULL) {
1344                         /* Create default channel */
1345                         attr = channel_new_default_attr(domain);
1346                         if (attr == NULL) {
1347                                 ret = LTTNG_ERR_FATAL;
1348                                 goto error;
1349                         }
1350                         strncpy(attr->name, channel_name, sizeof(attr->name));
1351
1352                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1353                         if (ret != LTTNG_OK) {
1354                                 free(attr);
1355                                 goto error;
1356                         }
1357                         free(attr);
1358
1359                         /* Get the newly created channel reference back */
1360                         uchan = trace_ust_find_channel_by_name(
1361                                         usess->domain_global.channels, channel_name);
1362                         assert(uchan);
1363                 }
1364
1365                 /* At this point, the session and channel exist on the tracer */
1366
1367                 switch (event_type) {
1368                 case LTTNG_EVENT_ALL:
1369                 case LTTNG_EVENT_TRACEPOINT:
1370                         ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
1371                         if (ret != LTTNG_OK) {
1372                                 goto error;
1373                         }
1374                         break;
1375                 default:
1376                         ret = LTTNG_ERR_UST_ENABLE_FAIL;
1377                         goto error;
1378                 }
1379
1380                 /* Manage return value */
1381                 if (ret != LTTNG_OK) {
1382                         goto error;
1383                 }
1384
1385                 break;
1386         }
1387 #if 0
1388         case LTTNG_DOMAIN_UST_EXEC_NAME:
1389         case LTTNG_DOMAIN_UST_PID:
1390         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1391 #endif
1392         default:
1393                 ret = LTTNG_ERR_UND;
1394                 goto error;
1395         }
1396
1397         ret = LTTNG_OK;
1398
1399 error:
1400         return ret;
1401 }
1402
1403
1404 /*
1405  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1406  */
1407 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1408 {
1409         int ret;
1410         ssize_t nb_events = 0;
1411
1412         switch (domain) {
1413         case LTTNG_DOMAIN_KERNEL:
1414                 nb_events = kernel_list_events(kernel_tracer_fd, events);
1415                 if (nb_events < 0) {
1416                         ret = LTTNG_ERR_KERN_LIST_FAIL;
1417                         goto error;
1418                 }
1419                 break;
1420         case LTTNG_DOMAIN_UST:
1421                 nb_events = ust_app_list_events(events);
1422                 if (nb_events < 0) {
1423                         ret = LTTNG_ERR_UST_LIST_FAIL;
1424                         goto error;
1425                 }
1426                 break;
1427         default:
1428                 ret = LTTNG_ERR_UND;
1429                 goto error;
1430         }
1431
1432         return nb_events;
1433
1434 error:
1435         /* Return negative value to differentiate return code */
1436         return -ret;
1437 }
1438
1439 /*
1440  * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1441  */
1442 ssize_t cmd_list_tracepoint_fields(int domain,
1443                 struct lttng_event_field **fields)
1444 {
1445         int ret;
1446         ssize_t nb_fields = 0;
1447
1448         switch (domain) {
1449         case LTTNG_DOMAIN_UST:
1450                 nb_fields = ust_app_list_event_fields(fields);
1451                 if (nb_fields < 0) {
1452                         ret = LTTNG_ERR_UST_LIST_FAIL;
1453                         goto error;
1454                 }
1455                 break;
1456         case LTTNG_DOMAIN_KERNEL:
1457         default:        /* fall-through */
1458                 ret = LTTNG_ERR_UND;
1459                 goto error;
1460         }
1461
1462         return nb_fields;
1463
1464 error:
1465         /* Return negative value to differentiate return code */
1466         return -ret;
1467 }
1468
1469 /*
1470  * Command LTTNG_START_TRACE processed by the client thread.
1471  */
1472 int cmd_start_trace(struct ltt_session *session)
1473 {
1474         int ret;
1475         struct ltt_kernel_session *ksession;
1476         struct ltt_ust_session *usess;
1477
1478         assert(session);
1479
1480         /* Ease our life a bit ;) */
1481         ksession = session->kernel_session;
1482         usess = session->ust_session;
1483
1484         if (session->enabled) {
1485                 /* Already started. */
1486                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1487                 goto error;
1488         }
1489
1490         session->enabled = 1;
1491
1492         ret = setup_relayd(session);
1493         if (ret != LTTNG_OK) {
1494                 ERR("Error setting up relayd for session %s", session->name);
1495                 goto error;
1496         }
1497
1498         /* Kernel tracing */
1499         if (ksession != NULL) {
1500                 ret = start_kernel_session(ksession, kernel_tracer_fd);
1501                 if (ret != LTTNG_OK) {
1502                         goto error;
1503                 }
1504         }
1505
1506         /* Flag session that trace should start automatically */
1507         if (usess) {
1508                 usess->start_trace = 1;
1509
1510                 ret = ust_app_start_trace_all(usess);
1511                 if (ret < 0) {
1512                         ret = LTTNG_ERR_UST_START_FAIL;
1513                         goto error;
1514                 }
1515         }
1516
1517         session->started = 1;
1518
1519         ret = LTTNG_OK;
1520
1521 error:
1522         return ret;
1523 }
1524
1525 /*
1526  * Command LTTNG_STOP_TRACE processed by the client thread.
1527  */
1528 int cmd_stop_trace(struct ltt_session *session)
1529 {
1530         int ret;
1531         struct ltt_kernel_channel *kchan;
1532         struct ltt_kernel_session *ksession;
1533         struct ltt_ust_session *usess;
1534
1535         assert(session);
1536
1537         /* Short cut */
1538         ksession = session->kernel_session;
1539         usess = session->ust_session;
1540
1541         if (!session->enabled) {
1542                 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
1543                 goto error;
1544         }
1545
1546         session->enabled = 0;
1547
1548         /* Kernel tracer */
1549         if (ksession) {
1550                 DBG("Stop kernel tracing");
1551
1552                 /* Flush metadata if exist */
1553                 if (ksession->metadata_stream_fd >= 0) {
1554                         ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1555                         if (ret < 0) {
1556                                 ERR("Kernel metadata flush failed");
1557                         }
1558                 }
1559
1560                 /* Flush all buffers before stopping */
1561                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1562                         ret = kernel_flush_buffer(kchan);
1563                         if (ret < 0) {
1564                                 ERR("Kernel flush buffer error");
1565                         }
1566                 }
1567
1568                 ret = kernel_stop_session(ksession);
1569                 if (ret < 0) {
1570                         ret = LTTNG_ERR_KERN_STOP_FAIL;
1571                         goto error;
1572                 }
1573
1574                 kernel_wait_quiescent(kernel_tracer_fd);
1575
1576                 ksession->started = 0;
1577         }
1578
1579         if (usess) {
1580                 usess->start_trace = 0;
1581
1582                 ret = ust_app_stop_trace_all(usess);
1583                 if (ret < 0) {
1584                         ret = LTTNG_ERR_UST_STOP_FAIL;
1585                         goto error;
1586                 }
1587         }
1588
1589         session->started = 0;
1590
1591         ret = LTTNG_OK;
1592
1593 error:
1594         return ret;
1595 }
1596
1597 /*
1598  * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1599  */
1600 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1601                 size_t nb_uri, struct lttng_uri *uris)
1602 {
1603         int ret, i;
1604         struct ltt_kernel_session *ksess = session->kernel_session;
1605         struct ltt_ust_session *usess = session->ust_session;
1606         struct consumer_output *consumer = NULL;
1607
1608         assert(session);
1609         assert(uris);
1610         assert(nb_uri > 0);
1611
1612         /* Can't enable consumer after session started. */
1613         if (session->enabled) {
1614                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1615                 goto error;
1616         }
1617
1618         /*
1619          * This case switch makes sure the domain session has a temporary consumer
1620          * so the URL can be set.
1621          */
1622         switch (domain) {
1623         case 0:
1624                 /* Code flow error. A session MUST always have a consumer object */
1625                 assert(session->consumer);
1626                 /*
1627                  * The URL will be added to the tracing session consumer instead of a
1628                  * specific domain consumer.
1629                  */
1630                 consumer = session->consumer;
1631                 break;
1632         case LTTNG_DOMAIN_KERNEL:
1633                 /* Code flow error if we don't have a kernel session here. */
1634                 assert(ksess);
1635
1636                 /* Create consumer output if none exists */
1637                 consumer = ksess->tmp_consumer;
1638                 if (consumer == NULL) {
1639                         consumer = consumer_copy_output(ksess->consumer);
1640                         if (consumer == NULL) {
1641                                 ret = LTTNG_ERR_FATAL;
1642                                 goto error;
1643                         }
1644                         /* Trash the consumer subdir, we are about to set a new one. */
1645                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1646                         ksess->tmp_consumer = consumer;
1647                 }
1648
1649                 break;
1650         case LTTNG_DOMAIN_UST:
1651                 /* Code flow error if we don't have a kernel session here. */
1652                 assert(usess);
1653
1654                 /* Create consumer output if none exists */
1655                 consumer = usess->tmp_consumer;
1656                 if (consumer == NULL) {
1657                         consumer = consumer_copy_output(usess->consumer);
1658                         if (consumer == NULL) {
1659                                 ret = LTTNG_ERR_FATAL;
1660                                 goto error;
1661                         }
1662                         /* Trash the consumer subdir, we are about to set a new one. */
1663                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1664                         usess->tmp_consumer = consumer;
1665                 }
1666
1667                 break;
1668         }
1669
1670         for (i = 0; i < nb_uri; i++) {
1671                 struct consumer_socket *socket;
1672                 struct lttng_ht_iter iter;
1673
1674                 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1675                 if (ret < 0) {
1676                         goto error;
1677                 }
1678
1679                 /*
1680                  * Don't send relayd socket if URI is NOT remote or if the relayd
1681                  * socket for the session was already sent.
1682                  */
1683                 if (uris[i].dtype == LTTNG_DST_PATH ||
1684                                 (uris[i].stype == LTTNG_STREAM_CONTROL &&
1685                                 consumer->dst.net.control_sock_sent) ||
1686                                 (uris[i].stype == LTTNG_STREAM_DATA &&
1687                                 consumer->dst.net.data_sock_sent)) {
1688                         continue;
1689                 }
1690
1691                 /* Try to send relayd URI to the consumer if exist. */
1692                 rcu_read_lock();
1693                 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
1694                                 socket, node.node) {
1695
1696                         /* A socket in the HT should never have a negative fd */
1697                         assert(socket->fd >= 0);
1698
1699                         pthread_mutex_lock(socket->lock);
1700                         ret = send_consumer_relayd_socket(domain, session, &uris[i],
1701                                         consumer, socket->fd);
1702                         pthread_mutex_unlock(socket->lock);
1703                         if (ret != LTTNG_OK) {
1704                                 rcu_read_unlock();
1705                                 goto error;
1706                         }
1707                 }
1708                 rcu_read_unlock();
1709         }
1710
1711         /* All good! */
1712         ret = LTTNG_OK;
1713
1714 error:
1715         return ret;
1716 }
1717
1718 /*
1719  * Command LTTNG_CREATE_SESSION processed by the client thread.
1720  */
1721 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1722                 size_t nb_uri, lttng_sock_cred *creds)
1723 {
1724         int ret;
1725         char *path = NULL;
1726         struct ltt_session *session;
1727
1728         assert(name);
1729
1730         /*
1731          * Verify if the session already exist
1732          *
1733          * XXX: There is no need for the session lock list here since the caller
1734          * (process_client_msg) is holding it. We might want to change that so a
1735          * single command does not lock the entire session list.
1736          */
1737         session = session_find_by_name(name);
1738         if (session != NULL) {
1739                 ret = LTTNG_ERR_EXIST_SESS;
1740                 goto find_error;
1741         }
1742
1743         /* Create tracing session in the registry */
1744         ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1745                         LTTNG_SOCK_GET_GID_CRED(creds));
1746         if (ret != LTTNG_OK) {
1747                 goto session_error;
1748         }
1749
1750         /*
1751          * Get the newly created session pointer back
1752          *
1753          * XXX: There is no need for the session lock list here since the caller
1754          * (process_client_msg) is holding it. We might want to change that so a
1755          * single command does not lock the entire session list.
1756          */
1757         session = session_find_by_name(name);
1758         assert(session);
1759
1760         /* Create default consumer output for the session not yet created. */
1761         session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1762         if (session->consumer == NULL) {
1763                 ret = LTTNG_ERR_FATAL;
1764                 goto consumer_error;
1765         }
1766
1767         /*
1768          * This means that the lttng_create_session call was called with the _path_
1769          * argument set to NULL.
1770          */
1771         if (uris == NULL) {
1772                 /*
1773                  * At this point, we'll skip the consumer URI setup and create a
1774                  * session with a NULL path which will flag the session to NOT spawn a
1775                  * consumer.
1776                  */
1777                 DBG("Create session %s with NO uri, skipping consumer setup", name);
1778                 goto end;
1779         }
1780
1781         session->start_consumer = 1;
1782
1783         ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1784         if (ret != LTTNG_OK) {
1785                 goto consumer_error;
1786         }
1787
1788         session->consumer->enabled = 1;
1789
1790 end:
1791         return LTTNG_OK;
1792
1793 consumer_error:
1794         session_destroy(session);
1795 session_error:
1796 find_error:
1797         return ret;
1798 }
1799
1800 /*
1801  * Command LTTNG_DESTROY_SESSION processed by the client thread.
1802  */
1803 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1804 {
1805         int ret;
1806         struct ltt_ust_session *usess;
1807         struct ltt_kernel_session *ksess;
1808
1809         /* Safety net */
1810         assert(session);
1811
1812         usess = session->ust_session;
1813         ksess = session->kernel_session;
1814
1815         /* Clean kernel session teardown */
1816         kernel_destroy_session(ksess);
1817
1818         /* UST session teardown */
1819         if (usess) {
1820                 /* Close any relayd session */
1821                 consumer_output_send_destroy_relayd(usess->consumer);
1822
1823                 /* Destroy every UST application related to this session. */
1824                 ret = ust_app_destroy_trace_all(usess);
1825                 if (ret) {
1826                         ERR("Error in ust_app_destroy_trace_all");
1827                 }
1828
1829                 /* Clean up the rest. */
1830                 trace_ust_destroy_session(usess);
1831         }
1832
1833         /*
1834          * Must notify the kernel thread here to update it's poll set in order to
1835          * remove the channel(s)' fd just destroyed.
1836          */
1837         ret = notify_thread_pipe(wpipe);
1838         if (ret < 0) {
1839                 PERROR("write kernel poll pipe");
1840         }
1841
1842         ret = session_destroy(session);
1843
1844         return ret;
1845 }
1846
1847 /*
1848  * Command LTTNG_CALIBRATE processed by the client thread.
1849  */
1850 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1851 {
1852         int ret;
1853
1854         switch (domain) {
1855         case LTTNG_DOMAIN_KERNEL:
1856         {
1857                 struct lttng_kernel_calibrate kcalibrate;
1858
1859                 kcalibrate.type = calibrate->type;
1860                 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1861                 if (ret < 0) {
1862                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1863                         goto error;
1864                 }
1865                 break;
1866         }
1867         case LTTNG_DOMAIN_UST:
1868         {
1869                 struct lttng_ust_calibrate ucalibrate;
1870
1871                 ucalibrate.type = calibrate->type;
1872                 ret = ust_app_calibrate_glb(&ucalibrate);
1873                 if (ret < 0) {
1874                         ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
1875                         goto error;
1876                 }
1877                 break;
1878         }
1879         default:
1880                 ret = LTTNG_ERR_UND;
1881                 goto error;
1882         }
1883
1884         ret = LTTNG_OK;
1885
1886 error:
1887         return ret;
1888 }
1889
1890 /*
1891  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1892  */
1893 int cmd_register_consumer(struct ltt_session *session, int domain,
1894                 const char *sock_path, struct consumer_data *cdata)
1895 {
1896         int ret, sock;
1897         struct consumer_socket *socket;
1898
1899         assert(session);
1900         assert(cdata);
1901         assert(sock_path);
1902
1903         switch (domain) {
1904         case LTTNG_DOMAIN_KERNEL:
1905         {
1906                 struct ltt_kernel_session *ksess = session->kernel_session;
1907
1908                 assert(ksess);
1909
1910                 /* Can't register a consumer if there is already one */
1911                 if (ksess->consumer_fds_sent != 0) {
1912                         ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1913                         goto error;
1914                 }
1915
1916                 sock = lttcomm_connect_unix_sock(sock_path);
1917                 if (sock < 0) {
1918                         ret = LTTNG_ERR_CONNECT_FAIL;
1919                         goto error;
1920                 }
1921
1922                 socket = consumer_allocate_socket(sock);
1923                 if (socket == NULL) {
1924                         ret = LTTNG_ERR_FATAL;
1925                         close(sock);
1926                         goto error;
1927                 }
1928
1929                 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1930                 if (socket->lock == NULL) {
1931                         PERROR("zmalloc pthread mutex");
1932                         ret = LTTNG_ERR_FATAL;
1933                         goto error;
1934                 }
1935                 pthread_mutex_init(socket->lock, NULL);
1936                 socket->registered = 1;
1937
1938                 rcu_read_lock();
1939                 consumer_add_socket(socket, ksess->consumer);
1940                 rcu_read_unlock();
1941
1942                 pthread_mutex_lock(&cdata->pid_mutex);
1943                 cdata->pid = -1;
1944                 pthread_mutex_unlock(&cdata->pid_mutex);
1945
1946                 break;
1947         }
1948         default:
1949                 /* TODO: Userspace tracing */
1950                 ret = LTTNG_ERR_UND;
1951                 goto error;
1952         }
1953
1954         ret = LTTNG_OK;
1955
1956 error:
1957         return ret;
1958 }
1959
1960 /*
1961  * Command LTTNG_LIST_DOMAINS processed by the client thread.
1962  */
1963 ssize_t cmd_list_domains(struct ltt_session *session,
1964                 struct lttng_domain **domains)
1965 {
1966         int ret, index = 0;
1967         ssize_t nb_dom = 0;
1968
1969         if (session->kernel_session != NULL) {
1970                 DBG3("Listing domains found kernel domain");
1971                 nb_dom++;
1972         }
1973
1974         if (session->ust_session != NULL) {
1975                 DBG3("Listing domains found UST global domain");
1976                 nb_dom++;
1977         }
1978
1979         *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1980         if (*domains == NULL) {
1981                 ret = LTTNG_ERR_FATAL;
1982                 goto error;
1983         }
1984
1985         if (session->kernel_session != NULL) {
1986                 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1987                 index++;
1988         }
1989
1990         if (session->ust_session != NULL) {
1991                 (*domains)[index].type = LTTNG_DOMAIN_UST;
1992                 index++;
1993         }
1994
1995         return nb_dom;
1996
1997 error:
1998         /* Return negative value to differentiate return code */
1999         return -ret;
2000 }
2001
2002
2003 /*
2004  * Command LTTNG_LIST_CHANNELS processed by the client thread.
2005  */
2006 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
2007                 struct lttng_channel **channels)
2008 {
2009         int ret;
2010         ssize_t nb_chan = 0;
2011
2012         switch (domain) {
2013         case LTTNG_DOMAIN_KERNEL:
2014                 if (session->kernel_session != NULL) {
2015                         nb_chan = session->kernel_session->channel_count;
2016                 }
2017                 DBG3("Number of kernel channels %zd", nb_chan);
2018                 if (nb_chan <= 0) {
2019                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
2020                 }
2021                 break;
2022         case LTTNG_DOMAIN_UST:
2023                 if (session->ust_session != NULL) {
2024                         nb_chan = lttng_ht_get_count(
2025                                         session->ust_session->domain_global.channels);
2026                 }
2027                 DBG3("Number of UST global channels %zd", nb_chan);
2028                 if (nb_chan <= 0) {
2029                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2030                 }
2031                 break;
2032         default:
2033                 *channels = NULL;
2034                 ret = LTTNG_ERR_UND;
2035                 goto error;
2036         }
2037
2038         if (nb_chan > 0) {
2039                 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2040                 if (*channels == NULL) {
2041                         ret = LTTNG_ERR_FATAL;
2042                         goto error;
2043                 }
2044
2045                 list_lttng_channels(domain, session, *channels);
2046         } else {
2047                 *channels = NULL;
2048                 /* Ret value was set in the domain switch case */
2049                 goto error;
2050         }
2051
2052         return nb_chan;
2053
2054 error:
2055         /* Return negative value to differentiate return code */
2056         return -ret;
2057 }
2058
2059 /*
2060  * Command LTTNG_LIST_EVENTS processed by the client thread.
2061  */
2062 ssize_t cmd_list_events(int domain, struct ltt_session *session,
2063                 char *channel_name, struct lttng_event **events)
2064 {
2065         int ret = 0;
2066         ssize_t nb_event = 0;
2067
2068         switch (domain) {
2069         case LTTNG_DOMAIN_KERNEL:
2070                 if (session->kernel_session != NULL) {
2071                         nb_event = list_lttng_kernel_events(channel_name,
2072                                         session->kernel_session, events);
2073                 }
2074                 break;
2075         case LTTNG_DOMAIN_UST:
2076         {
2077                 if (session->ust_session != NULL) {
2078                         nb_event = list_lttng_ust_global_events(channel_name,
2079                                         &session->ust_session->domain_global, events);
2080                 }
2081                 break;
2082         }
2083         default:
2084                 ret = LTTNG_ERR_UND;
2085                 goto error;
2086         }
2087
2088         return nb_event;
2089
2090 error:
2091         /* Return negative value to differentiate return code */
2092         return -ret;
2093 }
2094
2095 /*
2096  * Using the session list, filled a lttng_session array to send back to the
2097  * client for session listing.
2098  *
2099  * The session list lock MUST be acquired before calling this function. Use
2100  * session_lock_list() and session_unlock_list().
2101  */
2102 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2103                 gid_t gid)
2104 {
2105         int ret;
2106         unsigned int i = 0;
2107         struct ltt_session *session;
2108         struct ltt_session_list *list = session_get_list();
2109
2110         DBG("Getting all available session for UID %d GID %d",
2111                         uid, gid);
2112         /*
2113          * Iterate over session list and append data after the control struct in
2114          * the buffer.
2115          */
2116         cds_list_for_each_entry(session, &list->head, list) {
2117                 /*
2118                  * Only list the sessions the user can control.
2119                  */
2120                 if (!session_access_ok(session, uid, gid)) {
2121                         continue;
2122                 }
2123
2124                 struct ltt_kernel_session *ksess = session->kernel_session;
2125                 struct ltt_ust_session *usess = session->ust_session;
2126
2127                 if (session->consumer->type == CONSUMER_DST_NET ||
2128                                 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2129                                 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2130                         ret = build_network_session_path(sessions[i].path,
2131                                         sizeof(session[i].path), session);
2132                 } else {
2133                         ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2134                                         session->consumer->dst.trace_path);
2135                 }
2136                 if (ret < 0) {
2137                         PERROR("snprintf session path");
2138                         continue;
2139                 }
2140
2141                 strncpy(sessions[i].name, session->name, NAME_MAX);
2142                 sessions[i].name[NAME_MAX - 1] = '\0';
2143                 sessions[i].enabled = session->enabled;
2144                 i++;
2145         }
2146 }
2147
2148 /*
2149  * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2150  */
2151 int cmd_disable_consumer(int domain, struct ltt_session *session)
2152 {
2153         int ret;
2154         struct ltt_kernel_session *ksess = session->kernel_session;
2155         struct ltt_ust_session *usess = session->ust_session;
2156         struct consumer_output *consumer;
2157
2158         assert(session);
2159
2160         if (session->enabled) {
2161                 /* Can't disable consumer on an already started session */
2162                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2163                 goto error;
2164         }
2165
2166         if (!session->start_consumer) {
2167                 ret = LTTNG_ERR_NO_CONSUMER;
2168                 goto error;
2169         }
2170
2171         switch (domain) {
2172         case 0:
2173                 DBG("Disable tracing session %s consumer", session->name);
2174                 consumer = session->consumer;
2175                 break;
2176         case LTTNG_DOMAIN_KERNEL:
2177                 /* Code flow error if we don't have a kernel session here. */
2178                 assert(ksess);
2179
2180                 DBG("Disabling kernel consumer");
2181                 consumer = ksess->consumer;
2182
2183                 break;
2184         case LTTNG_DOMAIN_UST:
2185                 /* Code flow error if we don't have a UST session here. */
2186                 assert(usess);
2187
2188                 DBG("Disabling UST consumer");
2189                 consumer = usess->consumer;
2190
2191                 break;
2192         default:
2193                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
2194                 goto error;
2195         }
2196
2197         if (consumer) {
2198                 consumer->enabled = 0;
2199                 /* Success at this point */
2200                 ret = LTTNG_OK;
2201         } else {
2202                 ret = LTTNG_ERR_NO_CONSUMER;
2203         }
2204
2205 error:
2206         return ret;
2207 }
2208
2209 /*
2210  * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2211  */
2212 int cmd_enable_consumer(int domain, struct ltt_session *session)
2213 {
2214         int ret;
2215         struct ltt_kernel_session *ksess = session->kernel_session;
2216         struct ltt_ust_session *usess = session->ust_session;
2217         struct consumer_output *consumer = NULL;
2218
2219         assert(session);
2220
2221         /* Can't enable consumer after session started. */
2222         if (session->enabled) {
2223                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2224                 goto error;
2225         }
2226
2227         switch (domain) {
2228         case 0:
2229                 assert(session->consumer);
2230                 consumer = session->consumer;
2231                 break;
2232         case LTTNG_DOMAIN_KERNEL:
2233                 /* Code flow error if we don't have a kernel session here. */
2234                 assert(ksess);
2235
2236                 /*
2237                  * Check if we have already sent fds to the consumer. In that case,
2238                  * the enable-consumer command can't be used because a start trace
2239                  * had previously occured.
2240                  */
2241                 if (ksess->consumer_fds_sent) {
2242                         ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2243                         goto error;
2244                 }
2245
2246                 consumer = ksess->tmp_consumer;
2247                 if (consumer == NULL) {
2248                         ret = LTTNG_OK;
2249                         /* No temp. consumer output exists. Using the current one. */
2250                         DBG3("No temporary consumer. Using default");
2251                         consumer = ksess->consumer;
2252                         goto error;
2253                 }
2254
2255                 switch (consumer->type) {
2256                 case CONSUMER_DST_LOCAL:
2257                         DBG2("Consumer output is local. Creating directory(ies)");
2258
2259                         /* Create directory(ies) */
2260                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2261                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2262                         if (ret < 0) {
2263                                 if (ret != -EEXIST) {
2264                                         ERR("Trace directory creation error");
2265                                         ret = LTTNG_ERR_FATAL;
2266                                         goto error;
2267                                 }
2268                         }
2269                         break;
2270                 case CONSUMER_DST_NET:
2271                         DBG2("Consumer output is network. Validating URIs");
2272                         /* Validate if we have both control and data path set. */
2273                         if (!consumer->dst.net.control_isset) {
2274                                 ret = LTTNG_ERR_URL_CTRL_MISS;
2275                                 goto error;
2276                         }
2277
2278                         if (!consumer->dst.net.data_isset) {
2279                                 ret = LTTNG_ERR_URL_DATA_MISS;
2280                                 goto error;
2281                         }
2282
2283                         /* Check established network session state */
2284                         if (session->net_handle == 0) {
2285                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2286                                 ERR("Session network handle is not set on enable-consumer");
2287                                 goto error;
2288                         }
2289
2290                         break;
2291                 }
2292
2293                 /*
2294                  * @session-lock
2295                  * This is race free for now since the session lock is acquired before
2296                  * ending up in this function. No other threads can access this kernel
2297                  * session without this lock hence freeing the consumer output object
2298                  * is valid.
2299                  */
2300                 rcu_read_lock();
2301                 /* Destroy current consumer. We are about to replace it */
2302                 consumer_destroy_output(ksess->consumer);
2303                 rcu_read_unlock();
2304                 ksess->consumer = consumer;
2305                 ksess->tmp_consumer = NULL;
2306
2307                 break;
2308         case LTTNG_DOMAIN_UST:
2309                 /* Code flow error if we don't have a UST session here. */
2310                 assert(usess);
2311
2312                 /*
2313                  * Check if we have already sent fds to the consumer. In that case,
2314                  * the enable-consumer command can't be used because a start trace
2315                  * had previously occured.
2316                  */
2317                 if (usess->start_trace) {
2318                         ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2319                         goto error;
2320                 }
2321
2322                 consumer = usess->tmp_consumer;
2323                 if (consumer == NULL) {
2324                         ret = LTTNG_OK;
2325                         /* No temp. consumer output exists. Using the current one. */
2326                         DBG3("No temporary consumer. Using default");
2327                         consumer = usess->consumer;
2328                         goto error;
2329                 }
2330
2331                 switch (consumer->type) {
2332                 case CONSUMER_DST_LOCAL:
2333                         DBG2("Consumer output is local. Creating directory(ies)");
2334
2335                         /* Create directory(ies) */
2336                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2337                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2338                         if (ret < 0) {
2339                                 if (ret != -EEXIST) {
2340                                         ERR("Trace directory creation error");
2341                                         ret = LTTNG_ERR_FATAL;
2342                                         goto error;
2343                                 }
2344                         }
2345                         break;
2346                 case CONSUMER_DST_NET:
2347                         DBG2("Consumer output is network. Validating URIs");
2348                         /* Validate if we have both control and data path set. */
2349                         if (!consumer->dst.net.control_isset) {
2350                                 ret = LTTNG_ERR_URL_CTRL_MISS;
2351                                 goto error;
2352                         }
2353
2354                         if (!consumer->dst.net.data_isset) {
2355                                 ret = LTTNG_ERR_URL_DATA_MISS;
2356                                 goto error;
2357                         }
2358
2359                         /* Check established network session state */
2360                         if (session->net_handle == 0) {
2361                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2362                                 DBG2("Session network handle is not set on enable-consumer");
2363                                 goto error;
2364                         }
2365
2366                         if (consumer->net_seq_index == -1) {
2367                                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2368                                 DBG2("Network index is not set on the consumer");
2369                                 goto error;
2370                         }
2371
2372                         break;
2373                 }
2374
2375                 /*
2376                  * @session-lock
2377                  * This is race free for now since the session lock is acquired before
2378                  * ending up in this function. No other threads can access this kernel
2379                  * session without this lock hence freeing the consumer output object
2380                  * is valid.
2381                  */
2382                 rcu_read_lock();
2383                 /* Destroy current consumer. We are about to replace it */
2384                 consumer_destroy_output(usess->consumer);
2385                 rcu_read_unlock();
2386                 usess->consumer = consumer;
2387                 usess->tmp_consumer = NULL;
2388
2389                 break;
2390         }
2391
2392         session->start_consumer = 1;
2393
2394         /* Enable it */
2395         if (consumer) {
2396                 consumer->enabled = 1;
2397                 /* Success at this point */
2398                 ret = LTTNG_OK;
2399         } else {
2400                 /* Should not really happend... */
2401                 ret = LTTNG_ERR_NO_CONSUMER;
2402         }
2403
2404 error:
2405         return ret;
2406 }
2407
2408 /*
2409  * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
2410  * ready for trace analysis (or anykind of reader) or else 1 for pending data.
2411  */
2412 int cmd_data_pending(struct ltt_session *session)
2413 {
2414         int ret;
2415         struct ltt_kernel_session *ksess = session->kernel_session;
2416         struct ltt_ust_session *usess = session->ust_session;
2417
2418         assert(session);
2419
2420         /* Session MUST be stopped to ask for data availability. */
2421         if (session->enabled) {
2422                 ret = LTTNG_ERR_SESSION_STARTED;
2423                 goto error;
2424         }
2425
2426         if (ksess && ksess->consumer) {
2427                 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
2428                 if (ret == 1) {
2429                         /* Data is still being extracted for the kernel. */
2430                         goto error;
2431                 }
2432         }
2433
2434         if (usess && usess->consumer) {
2435                 ret = consumer_is_data_pending(usess->id, usess->consumer);
2436                 if (ret == 1) {
2437                         /* Data is still being extracted for the kernel. */
2438                         goto error;
2439                 }
2440         }
2441
2442         /* Data is ready to be read by a viewer */
2443         ret = 0;
2444
2445 error:
2446         return ret;
2447 }
2448
2449 /*
2450  * Init command subsystem.
2451  */
2452 void cmd_init(void)
2453 {
2454         /*
2455          * Set network sequence index to 1 for streams to match a relayd socket on
2456          * the consumer side.
2457          */
2458         uatomic_set(&relayd_net_seq_idx, 1);
2459
2460         DBG("Command subsystem initialized");
2461 }