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. It must be accessed with the relayd_net_seq_idx_lock
  42  * held.
  43  */
  44 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
  45 static uint64_t relayd_net_seq_idx;
  46
  47 /*
  48  * Create a session path used by list_lttng_sessions for the case that the
  49  * session consumer is on the network.
  50  */
  51 static int build_network_session_path(char *dst, size_t size,
  52                 struct ltt_session *session)
  53 {
  54         int ret, kdata_port, udata_port;
  55         struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
  56         char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
  57
  58         assert(session);
  59         assert(dst);
  60
  61         memset(tmp_urls, 0, sizeof(tmp_urls));
  62         memset(tmp_uurl, 0, sizeof(tmp_uurl));
  63
  64         kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
  65
  66         if (session->kernel_session && session->kernel_session->consumer) {
  67                 kuri = &session->kernel_session->consumer->dst.net.control;
  68                 kdata_port = session->kernel_session->consumer->dst.net.data.port;
  69         }
  70
  71         if (session->ust_session && session->ust_session->consumer) {
  72                 uuri = &session->ust_session->consumer->dst.net.control;
  73                 udata_port = session->ust_session->consumer->dst.net.data.port;
  74         }
  75
  76         if (uuri == NULL && kuri == NULL) {
  77                 uri = &session->consumer->dst.net.control;
  78                 kdata_port = session->consumer->dst.net.data.port;
  79         } else if (kuri && uuri) {
  80                 ret = uri_compare(kuri, uuri);
  81                 if (ret) {
  82                         /* Not Equal */
  83                         uri = kuri;
  84                         /* Build uuri URL string */
  85                         ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
  86                         if (ret < 0) {
  87                                 goto error;
  88                         }
  89                 } else {
  90                         uri = kuri;
  91                 }
  92         } else if (kuri && uuri == NULL) {
  93                 uri = kuri;
  94         } else if (uuri && kuri == NULL) {
  95                 uri = uuri;
  96         }
  97
  98         ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
  99         if (ret < 0) {
 100                 goto error;
 101         }
 102
 103         /*
 104          * Do we have a UST url set. If yes, this means we have both kernel and UST
 105          * to print.
 106          */
 107         if (*tmp_uurl != '\0') {
 108                 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
 109                                 tmp_urls, kdata_port, tmp_uurl, udata_port);
 110         } else {
 111                 int dport;
 112                 if (kuri) {
 113                         dport = kdata_port;
 114                 } else {
 115                         /* No kernel URI, use the UST port. */
 116                         dport = udata_port;
 117                 }
 118                 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
 119         }
 120
 121 error:
 122         return ret;
 123 }
 124
 125 /*
 126  * Fill lttng_channel array of all channels.
 127  */
 128 static void list_lttng_channels(int domain, struct ltt_session *session,
 129                 struct lttng_channel *channels)
 130 {
 131         int i = 0;
 132         struct ltt_kernel_channel *kchan;
 133
 134         DBG("Listing channels for session %s", session->name);
 135
 136         switch (domain) {
 137         case LTTNG_DOMAIN_KERNEL:
 138                 /* Kernel channels */
 139                 if (session->kernel_session != NULL) {
 140                         cds_list_for_each_entry(kchan,
 141                                         &session->kernel_session->channel_list.head, list) {
 142                                 /* Copy lttng_channel struct to array */
 143                                 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
 144                                 channels[i].enabled = kchan->enabled;
 145                                 i++;
 146                         }
 147                 }
 148                 break;
 149         case LTTNG_DOMAIN_UST:
 150         {
 151                 struct lttng_ht_iter iter;
 152                 struct ltt_ust_channel *uchan;
 153
 154                 rcu_read_lock();
 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                 rcu_read_unlock();
 175                 break;
 176         }
 177         default:
 178                 break;
 179         }
 180 }
 181
 182 /*
 183  * Create a list of ust global domain events.
 184  */
 185 static int list_lttng_ust_global_events(char *channel_name,
 186                 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
 187 {
 188         int i = 0, ret = 0;
 189         unsigned int nb_event = 0;
 190         struct lttng_ht_iter iter;
 191         struct lttng_ht_node_str *node;
 192         struct ltt_ust_channel *uchan;
 193         struct ltt_ust_event *uevent;
 194         struct lttng_event *tmp;
 195
 196         DBG("Listing UST global events for channel %s", channel_name);
 197
 198         rcu_read_lock();
 199
 200         lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
 201         node = lttng_ht_iter_get_node_str(&iter);
 202         if (node == NULL) {
 203                 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 204                 goto error;
 205         }
 206
 207         uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
 208
 209         nb_event += lttng_ht_get_count(uchan->events);
 210
 211         if (nb_event == 0) {
 212                 ret = nb_event;
 213                 goto error;
 214         }
 215
 216         DBG3("Listing UST global %d events", nb_event);
 217
 218         tmp = zmalloc(nb_event * sizeof(struct lttng_event));
 219         if (tmp == NULL) {
 220                 ret = LTTNG_ERR_FATAL;
 221                 goto error;
 222         }
 223
 224         cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
 225                 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
 226                 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 227                 tmp[i].enabled = uevent->enabled;
 228
 229                 switch (uevent->attr.instrumentation) {
 230                 case LTTNG_UST_TRACEPOINT:
 231                         tmp[i].type = LTTNG_EVENT_TRACEPOINT;
 232                         break;
 233                 case LTTNG_UST_PROBE:
 234                         tmp[i].type = LTTNG_EVENT_PROBE;
 235                         break;
 236                 case LTTNG_UST_FUNCTION:
 237                         tmp[i].type = LTTNG_EVENT_FUNCTION;
 238                         break;
 239                 }
 240
 241                 tmp[i].loglevel = uevent->attr.loglevel;
 242                 switch (uevent->attr.loglevel_type) {
 243                 case LTTNG_UST_LOGLEVEL_ALL:
 244                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 245                         break;
 246                 case LTTNG_UST_LOGLEVEL_RANGE:
 247                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 248                         break;
 249                 case LTTNG_UST_LOGLEVEL_SINGLE:
 250                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 251                         break;
 252                 }
 253                 if (uevent->filter) {
 254                         tmp[i].filter = 1;
 255                 }
 256                 i++;
 257         }
 258
 259         ret = nb_event;
 260         *events = tmp;
 261
 262 error:
 263         rcu_read_unlock();
 264         return ret;
 265 }
 266
 267 /*
 268  * Fill lttng_event array of all kernel events in the channel.
 269  */
 270 static int list_lttng_kernel_events(char *channel_name,
 271                 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
 272 {
 273         int i = 0, ret;
 274         unsigned int nb_event;
 275         struct ltt_kernel_event *event;
 276         struct ltt_kernel_channel *kchan;
 277
 278         kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
 279         if (kchan == NULL) {
 280                 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 281                 goto error;
 282         }
 283
 284         nb_event = kchan->event_count;
 285
 286         DBG("Listing events for channel %s", kchan->channel->name);
 287
 288         if (nb_event == 0) {
 289                 goto end;
 290         }
 291
 292         *events = zmalloc(nb_event * sizeof(struct lttng_event));
 293         if (*events == NULL) {
 294                 ret = LTTNG_ERR_FATAL;
 295                 goto error;
 296         }
 297
 298         /* Kernel channels */
 299         cds_list_for_each_entry(event, &kchan->events_list.head , list) {
 300                 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
 301                 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 302                 (*events)[i].enabled = event->enabled;
 303
 304                 switch (event->event->instrumentation) {
 305                 case LTTNG_KERNEL_TRACEPOINT:
 306                         (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
 307                         break;
 308                 case LTTNG_KERNEL_KPROBE:
 309                 case LTTNG_KERNEL_KRETPROBE:
 310                         (*events)[i].type = LTTNG_EVENT_PROBE;
 311                         memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
 312                                         sizeof(struct lttng_kernel_kprobe));
 313                         break;
 314                 case LTTNG_KERNEL_FUNCTION:
 315                         (*events)[i].type = LTTNG_EVENT_FUNCTION;
 316                         memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
 317                                         sizeof(struct lttng_kernel_function));
 318                         break;
 319                 case LTTNG_KERNEL_NOOP:
 320                         (*events)[i].type = LTTNG_EVENT_NOOP;
 321                         break;
 322                 case LTTNG_KERNEL_SYSCALL:
 323                         (*events)[i].type = LTTNG_EVENT_SYSCALL;
 324                         break;
 325                 case LTTNG_KERNEL_ALL:
 326                         assert(0);
 327                         break;
 328                 }
 329                 i++;
 330         }
 331
 332 end:
 333         return nb_event;
 334
 335 error:
 336         /* Negate the error code to differentiate the size from an error */
 337         return -ret;
 338 }
 339
 340 /*
 341  * Add URI so the consumer output object. Set the correct path depending on the
 342  * domain adding the default trace directory.
 343  */
 344 static int add_uri_to_consumer(struct consumer_output *consumer,
 345                 struct lttng_uri *uri, int domain, const char *session_name)
 346 {
 347         int ret = LTTNG_OK;
 348         const char *default_trace_dir;
 349
 350         assert(uri);
 351
 352         if (consumer == NULL) {
 353                 DBG("No consumer detected. Don't add URI. Stopping.");
 354                 ret = LTTNG_ERR_NO_CONSUMER;
 355                 goto error;
 356         }
 357
 358         switch (domain) {
 359         case LTTNG_DOMAIN_KERNEL:
 360                 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
 361                 break;
 362         case LTTNG_DOMAIN_UST:
 363                 default_trace_dir = DEFAULT_UST_TRACE_DIR;
 364                 break;
 365         default:
 366                 /*
 367                  * This case is possible is we try to add the URI to the global tracing
 368                  * session consumer object which in this case there is no subdir.
 369                  */
 370                 default_trace_dir = "";
 371         }
 372
 373         switch (uri->dtype) {
 374         case LTTNG_DST_IPV4:
 375         case LTTNG_DST_IPV6:
 376                 DBG2("Setting network URI to consumer");
 377
 378                 consumer->type = CONSUMER_DST_NET;
 379
 380                 if ((uri->stype == LTTNG_STREAM_CONTROL &&
 381                                 consumer->dst.net.control_isset) ||
 382                                 (uri->stype == LTTNG_STREAM_DATA &&
 383                                 consumer->dst.net.data_isset)) {
 384                         ret = LTTNG_ERR_URL_EXIST;
 385                         goto error;
 386                 }
 387
 388                 /* Set URI into consumer output object */
 389                 ret = consumer_set_network_uri(consumer, uri);
 390                 if (ret < 0) {
 391                         ret = LTTNG_ERR_FATAL;
 392                         goto error;
 393                 } else if (ret == 1) {
 394                         /*
 395                          * URI was the same in the consumer so we do not append the subdir
 396                          * again so to not duplicate output dir.
 397                          */
 398                         goto error;
 399                 }
 400
 401                 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
 402                         ret = consumer_set_subdir(consumer, session_name);
 403                         if (ret < 0) {
 404                                 ret = LTTNG_ERR_FATAL;
 405                                 goto error;
 406                         }
 407                 }
 408
 409                 if (uri->stype == LTTNG_STREAM_CONTROL) {
 410                         /* On a new subdir, reappend the default trace dir. */
 411                         strncat(consumer->subdir, default_trace_dir,
 412                                         sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
 413                         DBG3("Append domain trace name to subdir %s", consumer->subdir);
 414                 }
 415
 416                 break;
 417         case LTTNG_DST_PATH:
 418                 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
 419                 memset(consumer->dst.trace_path, 0,
 420                                 sizeof(consumer->dst.trace_path));
 421                 strncpy(consumer->dst.trace_path, uri->dst.path,
 422                                 sizeof(consumer->dst.trace_path));
 423                 /* Append default trace dir */
 424                 strncat(consumer->dst.trace_path, default_trace_dir,
 425                                 sizeof(consumer->dst.trace_path) -
 426                                 strlen(consumer->dst.trace_path) - 1);
 427                 /* Flag consumer as local. */
 428                 consumer->type = CONSUMER_DST_LOCAL;
 429                 break;
 430         }
 431
 432 error:
 433         return ret;
 434 }
 435
 436 /*
 437  * Init tracing by creating trace directory and sending fds kernel consumer.
 438  */
 439 static int init_kernel_tracing(struct ltt_kernel_session *session)
 440 {
 441         int ret = 0;
 442         struct lttng_ht_iter iter;
 443         struct consumer_socket *socket;
 444
 445         assert(session);
 446
 447         rcu_read_lock();
 448
 449         if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
 450                 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
 451                                 socket, node.node) {
 452                         /* Code flow error */
 453                         assert(socket->fd >= 0);
 454
 455                         pthread_mutex_lock(socket->lock);
 456                         ret = kernel_consumer_send_session(socket, session);
 457                         pthread_mutex_unlock(socket->lock);
 458                         if (ret < 0) {
 459                                 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 460                                 goto error;
 461                         }
 462                 }
 463         }
 464
 465 error:
 466         rcu_read_unlock();
 467         return ret;
 468 }
 469
 470 /*
 471  * Create a socket to the relayd using the URI.
 472  *
 473  * On success, the relayd_sock pointer is set to the created socket.
 474  * Else, it's stays untouched and a lttcomm error code is returned.
 475  */
 476 static int create_connect_relayd(struct consumer_output *output,
 477                 const char *session_name, struct lttng_uri *uri,
 478                 struct lttcomm_sock **relayd_sock)
 479 {
 480         int ret;
 481         struct lttcomm_sock *sock;
 482
 483         /* Create socket object from URI */
 484         sock = lttcomm_alloc_sock_from_uri(uri);
 485         if (sock == NULL) {
 486                 ret = LTTNG_ERR_FATAL;
 487                 goto error;
 488         }
 489
 490         ret = lttcomm_create_sock(sock);
 491         if (ret < 0) {
 492                 ret = LTTNG_ERR_FATAL;
 493                 goto error;
 494         }
 495
 496         /*
 497          * Connect to relayd so we can proceed with a session creation. This call
 498          * can possibly block for an arbitrary amount of time to set the health
 499          * state to be in poll execution.
 500          */
 501         health_poll_entry();
 502         ret = relayd_connect(sock);
 503         health_poll_exit();
 504         if (ret < 0) {
 505                 ERR("Unable to reach lttng-relayd");
 506                 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
 507                 goto free_sock;
 508         }
 509
 510         /* Create socket for control stream. */
 511         if (uri->stype == LTTNG_STREAM_CONTROL) {
 512                 DBG3("Creating relayd stream socket from URI");
 513
 514                 /* Check relayd version */
 515                 ret = relayd_version_check(sock, RELAYD_VERSION_COMM_MAJOR,
 516                                 RELAYD_VERSION_COMM_MINOR);
 517                 if (ret < 0) {
 518                         ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
 519                         goto close_sock;
 520                 }
 521         } else if (uri->stype == LTTNG_STREAM_DATA) {
 522                 DBG3("Creating relayd data socket from URI");
 523         } else {
 524                 /* Command is not valid */
 525                 ERR("Relayd invalid stream type: %d", uri->stype);
 526                 ret = LTTNG_ERR_INVALID;
 527                 goto close_sock;
 528         }
 529
 530         *relayd_sock = sock;
 531
 532         return LTTNG_OK;
 533
 534 close_sock:
 535         if (sock) {
 536                 (void) relayd_close(sock);
 537         }
 538 free_sock:
 539         if (sock) {
 540                 lttcomm_destroy_sock(sock);
 541         }
 542 error:
 543         return ret;
 544 }
 545
 546 /*
 547  * Connect to the relayd using URI and send the socket to the right consumer.
 548  */
 549 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
 550                 struct lttng_uri *relayd_uri, struct consumer_output *consumer,
 551                 struct consumer_socket *consumer_sock)
 552 {
 553         int ret;
 554         struct lttcomm_sock *sock = NULL;
 555
 556         /* Connect to relayd and make version check if uri is the control. */
 557         ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
 558         if (ret != LTTNG_OK) {
 559                 goto close_sock;
 560         }
 561
 562         /* If the control socket is connected, network session is ready */
 563         if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
 564                 session->net_handle = 1;
 565         }
 566
 567         /* Set the network sequence index if not set. */
 568         if (consumer->net_seq_index == (uint64_t) -1ULL) {
 569                 pthread_mutex_lock(&relayd_net_seq_idx_lock);
 570                 /*
 571                  * Increment net_seq_idx because we are about to transfer the
 572                  * new relayd socket to the consumer.
 573                  * Assign unique key so the consumer can match streams.
 574                  */
 575                 consumer->net_seq_index = ++relayd_net_seq_idx;
 576                 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
 577         }
 578
 579         /* Send relayd socket to consumer. */
 580         ret = consumer_send_relayd_socket(consumer_sock, sock,
 581                         consumer, relayd_uri->stype, session->id);
 582         if (ret < 0) {
 583                 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
 584                 goto close_sock;
 585         }
 586
 587         /* Flag that the corresponding socket was sent. */
 588         if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
 589                 consumer_sock->control_sock_sent = 1;
 590         } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
 591                 consumer_sock->data_sock_sent = 1;
 592         }
 593
 594         ret = LTTNG_OK;
 595
 596         /*
 597          * Close socket which was dup on the consumer side. The session daemon does
 598          * NOT keep track of the relayd socket(s) once transfer to the consumer.
 599          */
 600
 601 close_sock:
 602         if (sock) {
 603                 (void) relayd_close(sock);
 604                 lttcomm_destroy_sock(sock);
 605         }
 606
 607         if (ret != LTTNG_OK) {
 608                 /*
 609                  * On error, nullify the consumer sequence index so streams are not
 610                  * associated with it once sent to the consumer.
 611                  */
 612                 uatomic_set(&consumer->net_seq_index, -1);
 613         }
 614
 615         return ret;
 616 }
 617
 618 /*
 619  * Send both relayd sockets to a specific consumer and domain.  This is a
 620  * helper function to facilitate sending the information to the consumer for a
 621  * session.
 622  */
 623 static int send_consumer_relayd_sockets(int domain,
 624                 struct ltt_session *session, struct consumer_output *consumer,
 625                 struct consumer_socket *sock)
 626 {
 627         int ret = LTTNG_OK;
 628
 629         assert(session);
 630         assert(consumer);
 631
 632         /* Sending control relayd socket. */
 633         if (!sock->control_sock_sent) {
 634                 ret = send_consumer_relayd_socket(domain, session,
 635                                 &consumer->dst.net.control, consumer, sock);
 636                 if (ret != LTTNG_OK) {
 637                         goto error;
 638                 }
 639         }
 640
 641         /* Sending data relayd socket. */
 642         if (!sock->data_sock_sent) {
 643                 ret = send_consumer_relayd_socket(domain, session,
 644                                 &consumer->dst.net.data, consumer, sock);
 645                 if (ret != LTTNG_OK) {
 646                         goto error;
 647                 }
 648         }
 649
 650 error:
 651         return ret;
 652 }
 653
 654 /*
 655  * Setup relayd connections for a tracing session. First creates the socket to
 656  * the relayd and send them to the right domain consumer. Consumer type MUST be
 657  * network.
 658  */
 659 int cmd_setup_relayd(struct ltt_session *session)
 660 {
 661         int ret = LTTNG_OK;
 662         struct ltt_ust_session *usess;
 663         struct ltt_kernel_session *ksess;
 664         struct consumer_socket *socket;
 665         struct lttng_ht_iter iter;
 666
 667         assert(session);
 668
 669         usess = session->ust_session;
 670         ksess = session->kernel_session;
 671
 672         DBG("Setting relayd for session %s", session->name);
 673
 674         rcu_read_lock();
 675
 676         if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 677                         && usess->consumer->enabled) {
 678                 /* For each consumer socket, send relayd sockets */
 679                 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
 680                                 socket, node.node) {
 681                         /* Code flow error */
 682                         assert(socket->fd >= 0);
 683
 684                         pthread_mutex_lock(socket->lock);
 685                         ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
 686                                         usess->consumer, socket);
 687                         pthread_mutex_unlock(socket->lock);
 688                         if (ret != LTTNG_OK) {
 689                                 goto error;
 690                         }
 691                 }
 692         }
 693
 694         if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
 695                         && ksess->consumer->enabled) {
 696                 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
 697                                 socket, node.node) {
 698                         /* Code flow error */
 699                         assert(socket->fd >= 0);
 700
 701                         pthread_mutex_lock(socket->lock);
 702                         ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
 703                                         ksess->consumer, socket);
 704                         pthread_mutex_unlock(socket->lock);
 705                         if (ret != LTTNG_OK) {
 706                                 goto error;
 707                         }
 708                 }
 709         }
 710
 711 error:
 712         rcu_read_unlock();
 713         return ret;
 714 }
 715
 716 /*
 717  * Start a kernel session by opening all necessary streams.
 718  */
 719 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
 720 {
 721         int ret;
 722         struct ltt_kernel_channel *kchan;
 723
 724         /* Open kernel metadata */
 725         if (ksess->metadata == NULL) {
 726                 ret = kernel_open_metadata(ksess);
 727                 if (ret < 0) {
 728                         ret = LTTNG_ERR_KERN_META_FAIL;
 729                         goto error;
 730                 }
 731         }
 732
 733         /* Open kernel metadata stream */
 734         if (ksess->metadata_stream_fd < 0) {
 735                 ret = kernel_open_metadata_stream(ksess);
 736                 if (ret < 0) {
 737                         ERR("Kernel create metadata stream failed");
 738                         ret = LTTNG_ERR_KERN_STREAM_FAIL;
 739                         goto error;
 740                 }
 741         }
 742
 743         /* For each channel */
 744         cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
 745                 if (kchan->stream_count == 0) {
 746                         ret = kernel_open_channel_stream(kchan);
 747                         if (ret < 0) {
 748                                 ret = LTTNG_ERR_KERN_STREAM_FAIL;
 749                                 goto error;
 750                         }
 751                         /* Update the stream global counter */
 752                         ksess->stream_count_global += ret;
 753                 }
 754         }
 755
 756         /* Setup kernel consumer socket and send fds to it */
 757         ret = init_kernel_tracing(ksess);
 758         if (ret < 0) {
 759                 ret = LTTNG_ERR_KERN_START_FAIL;
 760                 goto error;
 761         }
 762
 763         /* This start the kernel tracing */
 764         ret = kernel_start_session(ksess);
 765         if (ret < 0) {
 766                 ret = LTTNG_ERR_KERN_START_FAIL;
 767                 goto error;
 768         }
 769
 770         /* Quiescent wait after starting trace */
 771         kernel_wait_quiescent(kernel_tracer_fd);
 772
 773         ksess->started = 1;
 774
 775         ret = LTTNG_OK;
 776
 777 error:
 778         return ret;
 779 }
 780
 781 /*
 782  * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
 783  */
 784 int cmd_disable_channel(struct ltt_session *session, int domain,
 785                 char *channel_name)
 786 {
 787         int ret;
 788         struct ltt_ust_session *usess;
 789
 790         usess = session->ust_session;
 791
 792         rcu_read_lock();
 793
 794         switch (domain) {
 795         case LTTNG_DOMAIN_KERNEL:
 796         {
 797                 ret = channel_kernel_disable(session->kernel_session,
 798                                 channel_name);
 799                 if (ret != LTTNG_OK) {
 800                         goto error;
 801                 }
 802
 803                 kernel_wait_quiescent(kernel_tracer_fd);
 804                 break;
 805         }
 806         case LTTNG_DOMAIN_UST:
 807         {
 808                 struct ltt_ust_channel *uchan;
 809                 struct lttng_ht *chan_ht;
 810
 811                 chan_ht = usess->domain_global.channels;
 812
 813                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 814                 if (uchan == NULL) {
 815                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 816                         goto error;
 817                 }
 818
 819                 ret = channel_ust_disable(usess, domain, uchan);
 820                 if (ret != LTTNG_OK) {
 821                         goto error;
 822                 }
 823                 break;
 824         }
 825 #if 0
 826         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 827         case LTTNG_DOMAIN_UST_EXEC_NAME:
 828         case LTTNG_DOMAIN_UST_PID:
 829 #endif
 830         default:
 831                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 832                 goto error;
 833         }
 834
 835         ret = LTTNG_OK;
 836
 837 error:
 838         rcu_read_unlock();
 839         return ret;
 840 }
 841
 842 /*
 843  * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
 844  *
 845  * The wpipe arguments is used as a notifier for the kernel thread.
 846  */
 847 int cmd_enable_channel(struct ltt_session *session,
 848                 int domain, struct lttng_channel *attr, int wpipe)
 849 {
 850         int ret;
 851         struct ltt_ust_session *usess = session->ust_session;
 852         struct lttng_ht *chan_ht;
 853
 854         assert(session);
 855         assert(attr);
 856
 857         DBG("Enabling channel %s for session %s", attr->name, session->name);
 858
 859         rcu_read_lock();
 860
 861         switch (domain) {
 862         case LTTNG_DOMAIN_KERNEL:
 863         {
 864                 struct ltt_kernel_channel *kchan;
 865
 866                 kchan = trace_kernel_get_channel_by_name(attr->name,
 867                                 session->kernel_session);
 868                 if (kchan == NULL) {
 869                         ret = channel_kernel_create(session->kernel_session, attr, wpipe);
 870                 } else {
 871                         ret = channel_kernel_enable(session->kernel_session, kchan);
 872                 }
 873
 874                 if (ret != LTTNG_OK) {
 875                         goto error;
 876                 }
 877
 878                 kernel_wait_quiescent(kernel_tracer_fd);
 879
 880                 /*
 881                  * If the session was previously started, start as well this newly
 882                  * created kernel session so the events/channels enabled *after* the
 883                  * start actually work.
 884                  */
 885                 if (session->started && !session->kernel_session->started) {
 886                         ret = start_kernel_session(session->kernel_session, wpipe);
 887                         if (ret != LTTNG_OK) {
 888                                 goto error;
 889                         }
 890                 }
 891                 break;
 892         }
 893         case LTTNG_DOMAIN_UST:
 894         {
 895                 struct ltt_ust_channel *uchan;
 896
 897                 chan_ht = usess->domain_global.channels;
 898
 899                 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
 900                 if (uchan == NULL) {
 901                         ret = channel_ust_create(usess, domain, attr);
 902                 } else {
 903                         ret = channel_ust_enable(usess, domain, uchan);
 904                 }
 905
 906                 /* Start the UST session if the session was already started. */
 907                 if (session->started && !usess->start_trace) {
 908                         ret = ust_app_start_trace_all(usess);
 909                         if (ret < 0) {
 910                                 ret = LTTNG_ERR_UST_START_FAIL;
 911                                 goto error;
 912                         }
 913                         ret = LTTNG_OK;
 914                         usess->start_trace = 1;
 915                 }
 916                 break;
 917         }
 918 #if 0
 919         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 920         case LTTNG_DOMAIN_UST_EXEC_NAME:
 921         case LTTNG_DOMAIN_UST_PID:
 922 #endif
 923         default:
 924                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 925                 goto error;
 926         }
 927
 928 error:
 929         rcu_read_unlock();
 930         return ret;
 931 }
 932
 933
 934 /*
 935  * Command LTTNG_DISABLE_EVENT processed by the client thread.
 936  */
 937 int cmd_disable_event(struct ltt_session *session, int domain,
 938                 char *channel_name, char *event_name)
 939 {
 940         int ret;
 941
 942         rcu_read_lock();
 943
 944         switch (domain) {
 945         case LTTNG_DOMAIN_KERNEL:
 946         {
 947                 struct ltt_kernel_channel *kchan;
 948                 struct ltt_kernel_session *ksess;
 949
 950                 ksess = session->kernel_session;
 951
 952                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 953                 if (kchan == NULL) {
 954                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 955                         goto error;
 956                 }
 957
 958                 ret = event_kernel_disable_tracepoint(kchan, event_name);
 959                 if (ret != LTTNG_OK) {
 960                         goto error;
 961                 }
 962
 963                 kernel_wait_quiescent(kernel_tracer_fd);
 964                 break;
 965         }
 966         case LTTNG_DOMAIN_UST:
 967         {
 968                 struct ltt_ust_channel *uchan;
 969                 struct ltt_ust_session *usess;
 970
 971                 usess = session->ust_session;
 972
 973                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 974                                 channel_name);
 975                 if (uchan == NULL) {
 976                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 977                         goto error;
 978                 }
 979
 980                 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
 981                 if (ret != LTTNG_OK) {
 982                         goto error;
 983                 }
 984
 985                 DBG3("Disable UST event %s in channel %s completed", event_name,
 986                                 channel_name);
 987                 break;
 988         }
 989 #if 0
 990         case LTTNG_DOMAIN_UST_EXEC_NAME:
 991         case LTTNG_DOMAIN_UST_PID:
 992         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 993 #endif
 994         default:
 995                 ret = LTTNG_ERR_UND;
 996                 goto error;
 997         }
 998
 999         ret = LTTNG_OK;
1000
1001 error:
1002         rcu_read_unlock();
1003         return ret;
1004 }
1005
1006 /*
1007  * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
1008  */
1009 int cmd_disable_event_all(struct ltt_session *session, int domain,
1010                 char *channel_name)
1011 {
1012         int ret;
1013
1014         rcu_read_lock();
1015
1016         switch (domain) {
1017         case LTTNG_DOMAIN_KERNEL:
1018         {
1019                 struct ltt_kernel_session *ksess;
1020                 struct ltt_kernel_channel *kchan;
1021
1022                 ksess = session->kernel_session;
1023
1024                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1025                 if (kchan == NULL) {
1026                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1027                         goto error;
1028                 }
1029
1030                 ret = event_kernel_disable_all(kchan);
1031                 if (ret != LTTNG_OK) {
1032                         goto error;
1033                 }
1034
1035                 kernel_wait_quiescent(kernel_tracer_fd);
1036                 break;
1037         }
1038         case LTTNG_DOMAIN_UST:
1039         {
1040                 struct ltt_ust_session *usess;
1041                 struct ltt_ust_channel *uchan;
1042
1043                 usess = session->ust_session;
1044
1045                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1046                                 channel_name);
1047                 if (uchan == NULL) {
1048                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1049                         goto error;
1050                 }
1051
1052                 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
1053                 if (ret != 0) {
1054                         goto error;
1055                 }
1056
1057                 DBG3("Disable all UST events in channel %s completed", channel_name);
1058
1059                 break;
1060         }
1061 #if 0
1062         case LTTNG_DOMAIN_UST_EXEC_NAME:
1063         case LTTNG_DOMAIN_UST_PID:
1064         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1065 #endif
1066         default:
1067                 ret = LTTNG_ERR_UND;
1068                 goto error;
1069         }
1070
1071         ret = LTTNG_OK;
1072
1073 error:
1074         rcu_read_unlock();
1075         return ret;
1076 }
1077
1078 /*
1079  * Command LTTNG_ADD_CONTEXT processed by the client thread.
1080  */
1081 int cmd_add_context(struct ltt_session *session, int domain,
1082                 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1083 {
1084         int ret;
1085
1086         switch (domain) {
1087         case LTTNG_DOMAIN_KERNEL:
1088                 assert(session->kernel_session);
1089
1090                 if (session->kernel_session->channel_count == 0) {
1091                         /* Create default channel */
1092                         ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1093                         if (ret != LTTNG_OK) {
1094                                 goto error;
1095                         }
1096                 }
1097
1098                 /* Add kernel context to kernel tracer */
1099                 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1100                 if (ret != LTTNG_OK) {
1101                         goto error;
1102                 }
1103                 break;
1104         case LTTNG_DOMAIN_UST:
1105         {
1106                 struct ltt_ust_session *usess = session->ust_session;
1107                 assert(usess);
1108
1109                 unsigned int chan_count =
1110                         lttng_ht_get_count(usess->domain_global.channels);
1111                 if (chan_count == 0) {
1112                         struct lttng_channel *attr;
1113                         /* Create default channel */
1114                         attr = channel_new_default_attr(domain);
1115                         if (attr == NULL) {
1116                                 ret = LTTNG_ERR_FATAL;
1117                                 goto error;
1118                         }
1119
1120                         ret = channel_ust_create(usess, domain, attr);
1121                         if (ret != LTTNG_OK) {
1122                                 free(attr);
1123                                 goto error;
1124                         }
1125                         free(attr);
1126                 }
1127
1128                 ret = context_ust_add(usess, domain, ctx, channel_name);
1129                 if (ret != LTTNG_OK) {
1130                         goto error;
1131                 }
1132                 break;
1133         }
1134 #if 0
1135         case LTTNG_DOMAIN_UST_EXEC_NAME:
1136         case LTTNG_DOMAIN_UST_PID:
1137         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1138 #endif
1139         default:
1140                 ret = LTTNG_ERR_UND;
1141                 goto error;
1142         }
1143
1144         ret = LTTNG_OK;
1145
1146 error:
1147         return ret;
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,
1155                 struct lttng_filter_bytecode *filter, int wpipe)
1156 {
1157         int ret, channel_created = 0;
1158         struct lttng_channel *attr;
1159
1160         assert(session);
1161         assert(event);
1162         assert(channel_name);
1163
1164         rcu_read_lock();
1165
1166         switch (domain) {
1167         case LTTNG_DOMAIN_KERNEL:
1168         {
1169                 struct ltt_kernel_channel *kchan;
1170
1171                 kchan = trace_kernel_get_channel_by_name(channel_name,
1172                                 session->kernel_session);
1173                 if (kchan == NULL) {
1174                         attr = channel_new_default_attr(domain);
1175                         if (attr == NULL) {
1176                                 ret = LTTNG_ERR_FATAL;
1177                                 goto error;
1178                         }
1179                         strncpy(attr->name, channel_name, sizeof(attr->name));
1180
1181                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1182                         if (ret != LTTNG_OK) {
1183                                 free(attr);
1184                                 goto error;
1185                         }
1186                         free(attr);
1187
1188                         channel_created = 1;
1189                 }
1190
1191                 /* Get the newly created kernel channel pointer */
1192                 kchan = trace_kernel_get_channel_by_name(channel_name,
1193                                 session->kernel_session);
1194                 if (kchan == NULL) {
1195                         /* This sould not happen... */
1196                         ret = LTTNG_ERR_FATAL;
1197                         goto error;
1198                 }
1199
1200                 ret = event_kernel_enable_tracepoint(kchan, event);
1201                 if (ret != LTTNG_OK) {
1202                         if (channel_created) {
1203                                 /* Let's not leak a useless channel. */
1204                                 kernel_destroy_channel(kchan);
1205                         }
1206                         goto error;
1207                 }
1208
1209                 kernel_wait_quiescent(kernel_tracer_fd);
1210                 break;
1211         }
1212         case LTTNG_DOMAIN_UST:
1213         {
1214                 struct ltt_ust_channel *uchan;
1215                 struct ltt_ust_session *usess = session->ust_session;
1216
1217                 assert(usess);
1218
1219                 /* Get channel from global UST domain */
1220                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1221                                 channel_name);
1222                 if (uchan == NULL) {
1223                         /* Create default channel */
1224                         attr = channel_new_default_attr(domain);
1225                         if (attr == NULL) {
1226                                 ret = LTTNG_ERR_FATAL;
1227                                 goto error;
1228                         }
1229                         strncpy(attr->name, channel_name, sizeof(attr->name));
1230
1231                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1232                         if (ret != LTTNG_OK) {
1233                                 free(attr);
1234                                 goto error;
1235                         }
1236                         free(attr);
1237
1238                         /* Get the newly created channel reference back */
1239                         uchan = trace_ust_find_channel_by_name(
1240                                         usess->domain_global.channels, channel_name);
1241                         assert(uchan);
1242                 }
1243
1244                 /* At this point, the session and channel exist on the tracer */
1245                 ret = event_ust_enable_tracepoint(usess, domain, uchan, event, filter);
1246                 if (ret != LTTNG_OK) {
1247                         goto error;
1248                 }
1249                 break;
1250         }
1251 #if 0
1252         case LTTNG_DOMAIN_UST_EXEC_NAME:
1253         case LTTNG_DOMAIN_UST_PID:
1254         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1255 #endif
1256         default:
1257                 ret = LTTNG_ERR_UND;
1258                 goto error;
1259         }
1260
1261         ret = LTTNG_OK;
1262
1263 error:
1264         rcu_read_unlock();
1265         return ret;
1266 }
1267
1268 /*
1269  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1270  */
1271 int cmd_enable_event_all(struct ltt_session *session, int domain,
1272                 char *channel_name, int event_type,
1273                 struct lttng_filter_bytecode *filter, int wpipe)
1274 {
1275         int ret;
1276         struct lttng_channel *attr;
1277
1278         assert(session);
1279         assert(channel_name);
1280
1281         rcu_read_lock();
1282
1283         switch (domain) {
1284         case LTTNG_DOMAIN_KERNEL:
1285         {
1286                 struct ltt_kernel_channel *kchan;
1287
1288                 assert(session->kernel_session);
1289
1290                 kchan = trace_kernel_get_channel_by_name(channel_name,
1291                                 session->kernel_session);
1292                 if (kchan == NULL) {
1293                         /* Create default channel */
1294                         attr = channel_new_default_attr(domain);
1295                         if (attr == NULL) {
1296                                 ret = LTTNG_ERR_FATAL;
1297                                 goto error;
1298                         }
1299                         strncpy(attr->name, channel_name, sizeof(attr->name));
1300
1301                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1302                         if (ret != LTTNG_OK) {
1303                                 free(attr);
1304                                 goto error;
1305                         }
1306                         free(attr);
1307
1308                         /* Get the newly created kernel channel pointer */
1309                         kchan = trace_kernel_get_channel_by_name(channel_name,
1310                                         session->kernel_session);
1311                         assert(kchan);
1312                 }
1313
1314                 switch (event_type) {
1315                 case LTTNG_EVENT_SYSCALL:
1316                         ret = event_kernel_enable_all_syscalls(kchan, kernel_tracer_fd);
1317                         break;
1318                 case LTTNG_EVENT_TRACEPOINT:
1319                         /*
1320                          * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1321                          * events already registered to the channel.
1322                          */
1323                         ret = event_kernel_enable_all_tracepoints(kchan, kernel_tracer_fd);
1324                         break;
1325                 case LTTNG_EVENT_ALL:
1326                         /* Enable syscalls and tracepoints */
1327                         ret = event_kernel_enable_all(kchan, kernel_tracer_fd);
1328                         break;
1329                 default:
1330                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1331                         goto error;
1332                 }
1333
1334                 /* Manage return value */
1335                 if (ret != LTTNG_OK) {
1336                         /*
1337                          * On error, cmd_enable_channel call will take care of destroying
1338                          * the created channel if it was needed.
1339                          */
1340                         goto error;
1341                 }
1342
1343                 kernel_wait_quiescent(kernel_tracer_fd);
1344                 break;
1345         }
1346         case LTTNG_DOMAIN_UST:
1347         {
1348                 struct ltt_ust_channel *uchan;
1349                 struct ltt_ust_session *usess = session->ust_session;
1350
1351                 assert(usess);
1352
1353                 /* Get channel from global UST domain */
1354                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1355                                 channel_name);
1356                 if (uchan == NULL) {
1357                         /* Create default channel */
1358                         attr = channel_new_default_attr(domain);
1359                         if (attr == NULL) {
1360                                 ret = LTTNG_ERR_FATAL;
1361                                 goto error;
1362                         }
1363                         strncpy(attr->name, channel_name, sizeof(attr->name));
1364
1365                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1366                         if (ret != LTTNG_OK) {
1367                                 free(attr);
1368                                 goto error;
1369                         }
1370                         free(attr);
1371
1372                         /* Get the newly created channel reference back */
1373                         uchan = trace_ust_find_channel_by_name(
1374                                         usess->domain_global.channels, channel_name);
1375                         assert(uchan);
1376                 }
1377
1378                 /* At this point, the session and channel exist on the tracer */
1379
1380                 switch (event_type) {
1381                 case LTTNG_EVENT_ALL:
1382                 case LTTNG_EVENT_TRACEPOINT:
1383                         ret = event_ust_enable_all_tracepoints(usess, domain, uchan,
1384                                         filter);
1385                         if (ret != LTTNG_OK) {
1386                                 goto error;
1387                         }
1388                         break;
1389                 default:
1390                         ret = LTTNG_ERR_UST_ENABLE_FAIL;
1391                         goto error;
1392                 }
1393
1394                 /* Manage return value */
1395                 if (ret != LTTNG_OK) {
1396                         goto error;
1397                 }
1398
1399                 break;
1400         }
1401 #if 0
1402         case LTTNG_DOMAIN_UST_EXEC_NAME:
1403         case LTTNG_DOMAIN_UST_PID:
1404         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1405 #endif
1406         default:
1407                 ret = LTTNG_ERR_UND;
1408                 goto error;
1409         }
1410
1411         ret = LTTNG_OK;
1412
1413 error:
1414         rcu_read_unlock();
1415         return ret;
1416 }
1417
1418
1419 /*
1420  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1421  */
1422 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1423 {
1424         int ret;
1425         ssize_t nb_events = 0;
1426
1427         switch (domain) {
1428         case LTTNG_DOMAIN_KERNEL:
1429                 nb_events = kernel_list_events(kernel_tracer_fd, events);
1430                 if (nb_events < 0) {
1431                         ret = LTTNG_ERR_KERN_LIST_FAIL;
1432                         goto error;
1433                 }
1434                 break;
1435         case LTTNG_DOMAIN_UST:
1436                 nb_events = ust_app_list_events(events);
1437                 if (nb_events < 0) {
1438                         ret = LTTNG_ERR_UST_LIST_FAIL;
1439                         goto error;
1440                 }
1441                 break;
1442         default:
1443                 ret = LTTNG_ERR_UND;
1444                 goto error;
1445         }
1446
1447         return nb_events;
1448
1449 error:
1450         /* Return negative value to differentiate return code */
1451         return -ret;
1452 }
1453
1454 /*
1455  * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1456  */
1457 ssize_t cmd_list_tracepoint_fields(int domain,
1458                 struct lttng_event_field **fields)
1459 {
1460         int ret;
1461         ssize_t nb_fields = 0;
1462
1463         switch (domain) {
1464         case LTTNG_DOMAIN_UST:
1465                 nb_fields = ust_app_list_event_fields(fields);
1466                 if (nb_fields < 0) {
1467                         ret = LTTNG_ERR_UST_LIST_FAIL;
1468                         goto error;
1469                 }
1470                 break;
1471         case LTTNG_DOMAIN_KERNEL:
1472         default:        /* fall-through */
1473                 ret = LTTNG_ERR_UND;
1474                 goto error;
1475         }
1476
1477         return nb_fields;
1478
1479 error:
1480         /* Return negative value to differentiate return code */
1481         return -ret;
1482 }
1483
1484 /*
1485  * Command LTTNG_START_TRACE processed by the client thread.
1486  */
1487 int cmd_start_trace(struct ltt_session *session)
1488 {
1489         int ret;
1490         struct ltt_kernel_session *ksession;
1491         struct ltt_ust_session *usess;
1492
1493         assert(session);
1494
1495         /* Ease our life a bit ;) */
1496         ksession = session->kernel_session;
1497         usess = session->ust_session;
1498
1499         if (session->enabled) {
1500                 /* Already started. */
1501                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1502                 goto error;
1503         }
1504
1505         session->enabled = 1;
1506
1507         /* Kernel tracing */
1508         if (ksession != NULL) {
1509                 ret = start_kernel_session(ksession, kernel_tracer_fd);
1510                 if (ret != LTTNG_OK) {
1511                         goto error;
1512                 }
1513         }
1514
1515         /* Flag session that trace should start automatically */
1516         if (usess) {
1517                 usess->start_trace = 1;
1518
1519                 ret = ust_app_start_trace_all(usess);
1520                 if (ret < 0) {
1521                         ret = LTTNG_ERR_UST_START_FAIL;
1522                         goto error;
1523                 }
1524         }
1525
1526         session->started = 1;
1527
1528         ret = LTTNG_OK;
1529
1530 error:
1531         return ret;
1532 }
1533
1534 /*
1535  * Command LTTNG_STOP_TRACE processed by the client thread.
1536  */
1537 int cmd_stop_trace(struct ltt_session *session)
1538 {
1539         int ret;
1540         struct ltt_kernel_channel *kchan;
1541         struct ltt_kernel_session *ksession;
1542         struct ltt_ust_session *usess;
1543
1544         assert(session);
1545
1546         /* Short cut */
1547         ksession = session->kernel_session;
1548         usess = session->ust_session;
1549
1550         if (!session->enabled) {
1551                 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
1552                 goto error;
1553         }
1554
1555         session->enabled = 0;
1556
1557         /* Kernel tracer */
1558         if (ksession) {
1559                 DBG("Stop kernel tracing");
1560
1561                 /* Flush metadata if exist */
1562                 if (ksession->metadata_stream_fd >= 0) {
1563                         ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1564                         if (ret < 0) {
1565                                 ERR("Kernel metadata flush failed");
1566                         }
1567                 }
1568
1569                 /* Flush all buffers before stopping */
1570                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1571                         ret = kernel_flush_buffer(kchan);
1572                         if (ret < 0) {
1573                                 ERR("Kernel flush buffer error");
1574                         }
1575                 }
1576
1577                 ret = kernel_stop_session(ksession);
1578                 if (ret < 0) {
1579                         ret = LTTNG_ERR_KERN_STOP_FAIL;
1580                         goto error;
1581                 }
1582
1583                 kernel_wait_quiescent(kernel_tracer_fd);
1584
1585                 ksession->started = 0;
1586         }
1587
1588         if (usess) {
1589                 usess->start_trace = 0;
1590
1591                 ret = ust_app_stop_trace_all(usess);
1592                 if (ret < 0) {
1593                         ret = LTTNG_ERR_UST_STOP_FAIL;
1594                         goto error;
1595                 }
1596         }
1597
1598         session->started = 0;
1599
1600         ret = LTTNG_OK;
1601
1602 error:
1603         return ret;
1604 }
1605
1606 /*
1607  * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1608  */
1609 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1610                 size_t nb_uri, struct lttng_uri *uris)
1611 {
1612         int ret, i;
1613         struct ltt_kernel_session *ksess = session->kernel_session;
1614         struct ltt_ust_session *usess = session->ust_session;
1615         struct consumer_output *consumer = NULL;
1616
1617         assert(session);
1618         assert(uris);
1619         assert(nb_uri > 0);
1620
1621         /* Can't enable consumer after session started. */
1622         if (session->enabled) {
1623                 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1624                 goto error;
1625         }
1626
1627         /*
1628          * This case switch makes sure the domain session has a temporary consumer
1629          * so the URL can be set.
1630          */
1631         switch (domain) {
1632         case 0:
1633                 /* Code flow error. A session MUST always have a consumer object */
1634                 assert(session->consumer);
1635                 /*
1636                  * The URL will be added to the tracing session consumer instead of a
1637                  * specific domain consumer.
1638                  */
1639                 consumer = session->consumer;
1640                 break;
1641         case LTTNG_DOMAIN_KERNEL:
1642                 /* Code flow error if we don't have a kernel session here. */
1643                 assert(ksess);
1644                 assert(ksess->consumer);
1645                 consumer = ksess->consumer;
1646                 break;
1647         case LTTNG_DOMAIN_UST:
1648                 /* Code flow error if we don't have a kernel session here. */
1649                 assert(usess);
1650                 assert(usess->consumer);
1651                 consumer = usess->consumer;
1652                 break;
1653         }
1654
1655         for (i = 0; i < nb_uri; i++) {
1656                 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1657                 if (ret < 0) {
1658                         goto error;
1659                 }
1660         }
1661
1662         /* All good! */
1663         ret = LTTNG_OK;
1664
1665 error:
1666         return ret;
1667 }
1668
1669 /*
1670  * Command LTTNG_CREATE_SESSION processed by the client thread.
1671  */
1672 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1673                 size_t nb_uri, lttng_sock_cred *creds)
1674 {
1675         int ret;
1676         char *path = NULL;
1677         struct ltt_session *session;
1678
1679         assert(name);
1680
1681         /* No URIs is not possible. */
1682         if (uris == NULL) {
1683                 ret = LTTNG_ERR_SESSION_FAIL;
1684                 goto session_error;
1685         }
1686
1687         /*
1688          * Verify if the session already exist
1689          *
1690          * XXX: There is no need for the session lock list here since the caller
1691          * (process_client_msg) is holding it. We might want to change that so a
1692          * single command does not lock the entire session list.
1693          */
1694         session = session_find_by_name(name);
1695         if (session != NULL) {
1696                 ret = LTTNG_ERR_EXIST_SESS;
1697                 goto find_error;
1698         }
1699
1700         /* Create tracing session in the registry */
1701         ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1702                         LTTNG_SOCK_GET_GID_CRED(creds));
1703         if (ret != LTTNG_OK) {
1704                 goto session_error;
1705         }
1706
1707         /*
1708          * Get the newly created session pointer back
1709          *
1710          * XXX: There is no need for the session lock list here since the caller
1711          * (process_client_msg) is holding it. We might want to change that so a
1712          * single command does not lock the entire session list.
1713          */
1714         session = session_find_by_name(name);
1715         assert(session);
1716
1717         /* Create default consumer output for the session not yet created. */
1718         session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1719         if (session->consumer == NULL) {
1720                 ret = LTTNG_ERR_FATAL;
1721                 goto consumer_error;
1722         }
1723
1724         ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1725         if (ret != LTTNG_OK) {
1726                 goto consumer_error;
1727         }
1728
1729         session->consumer->enabled = 1;
1730
1731         return LTTNG_OK;
1732
1733 consumer_error:
1734         session_destroy(session);
1735 session_error:
1736 find_error:
1737         return ret;
1738 }
1739
1740 /*
1741  * Command LTTNG_DESTROY_SESSION processed by the client thread.
1742  */
1743 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1744 {
1745         int ret;
1746         struct ltt_ust_session *usess;
1747         struct ltt_kernel_session *ksess;
1748
1749         /* Safety net */
1750         assert(session);
1751
1752         usess = session->ust_session;
1753         ksess = session->kernel_session;
1754
1755         /* Clean kernel session teardown */
1756         kernel_destroy_session(ksess);
1757
1758         /* UST session teardown */
1759         if (usess) {
1760                 /* Close any relayd session */
1761                 consumer_output_send_destroy_relayd(usess->consumer);
1762
1763                 /* Destroy every UST application related to this session. */
1764                 ret = ust_app_destroy_trace_all(usess);
1765                 if (ret) {
1766                         ERR("Error in ust_app_destroy_trace_all");
1767                 }
1768
1769                 /* Clean up the rest. */
1770                 trace_ust_destroy_session(usess);
1771         }
1772
1773         /*
1774          * Must notify the kernel thread here to update it's poll set in order to
1775          * remove the channel(s)' fd just destroyed.
1776          */
1777         ret = notify_thread_pipe(wpipe);
1778         if (ret < 0) {
1779                 PERROR("write kernel poll pipe");
1780         }
1781
1782         ret = session_destroy(session);
1783
1784         return ret;
1785 }
1786
1787 /*
1788  * Command LTTNG_CALIBRATE processed by the client thread.
1789  */
1790 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1791 {
1792         int ret;
1793
1794         switch (domain) {
1795         case LTTNG_DOMAIN_KERNEL:
1796         {
1797                 struct lttng_kernel_calibrate kcalibrate;
1798
1799                 kcalibrate.type = calibrate->type;
1800                 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1801                 if (ret < 0) {
1802                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1803                         goto error;
1804                 }
1805                 break;
1806         }
1807         case LTTNG_DOMAIN_UST:
1808         {
1809                 struct lttng_ust_calibrate ucalibrate;
1810
1811                 ucalibrate.type = calibrate->type;
1812                 ret = ust_app_calibrate_glb(&ucalibrate);
1813                 if (ret < 0) {
1814                         ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
1815                         goto error;
1816                 }
1817                 break;
1818         }
1819         default:
1820                 ret = LTTNG_ERR_UND;
1821                 goto error;
1822         }
1823
1824         ret = LTTNG_OK;
1825
1826 error:
1827         return ret;
1828 }
1829
1830 /*
1831  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1832  */
1833 int cmd_register_consumer(struct ltt_session *session, int domain,
1834                 const char *sock_path, struct consumer_data *cdata)
1835 {
1836         int ret, sock;
1837         struct consumer_socket *socket;
1838
1839         assert(session);
1840         assert(cdata);
1841         assert(sock_path);
1842
1843         switch (domain) {
1844         case LTTNG_DOMAIN_KERNEL:
1845         {
1846                 struct ltt_kernel_session *ksess = session->kernel_session;
1847
1848                 assert(ksess);
1849
1850                 /* Can't register a consumer if there is already one */
1851                 if (ksess->consumer_fds_sent != 0) {
1852                         ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1853                         goto error;
1854                 }
1855
1856                 sock = lttcomm_connect_unix_sock(sock_path);
1857                 if (sock < 0) {
1858                         ret = LTTNG_ERR_CONNECT_FAIL;
1859                         goto error;
1860                 }
1861
1862                 socket = consumer_allocate_socket(sock);
1863                 if (socket == NULL) {
1864                         ret = close(sock);
1865                         if (ret < 0) {
1866                                 PERROR("close register consumer");
1867                         }
1868                         ret = LTTNG_ERR_FATAL;
1869                         goto error;
1870                 }
1871
1872                 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1873                 if (socket->lock == NULL) {
1874                         PERROR("zmalloc pthread mutex");
1875                         ret = LTTNG_ERR_FATAL;
1876                         goto error;
1877                 }
1878                 pthread_mutex_init(socket->lock, NULL);
1879                 socket->registered = 1;
1880
1881                 rcu_read_lock();
1882                 consumer_add_socket(socket, ksess->consumer);
1883                 rcu_read_unlock();
1884
1885                 pthread_mutex_lock(&cdata->pid_mutex);
1886                 cdata->pid = -1;
1887                 pthread_mutex_unlock(&cdata->pid_mutex);
1888
1889                 break;
1890         }
1891         default:
1892                 /* TODO: Userspace tracing */
1893                 ret = LTTNG_ERR_UND;
1894                 goto error;
1895         }
1896
1897         ret = LTTNG_OK;
1898
1899 error:
1900         return ret;
1901 }
1902
1903 /*
1904  * Command LTTNG_LIST_DOMAINS processed by the client thread.
1905  */
1906 ssize_t cmd_list_domains(struct ltt_session *session,
1907                 struct lttng_domain **domains)
1908 {
1909         int ret, index = 0;
1910         ssize_t nb_dom = 0;
1911
1912         if (session->kernel_session != NULL) {
1913                 DBG3("Listing domains found kernel domain");
1914                 nb_dom++;
1915         }
1916
1917         if (session->ust_session != NULL) {
1918                 DBG3("Listing domains found UST global domain");
1919                 nb_dom++;
1920         }
1921
1922         *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1923         if (*domains == NULL) {
1924                 ret = LTTNG_ERR_FATAL;
1925                 goto error;
1926         }
1927
1928         if (session->kernel_session != NULL) {
1929                 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1930                 index++;
1931         }
1932
1933         if (session->ust_session != NULL) {
1934                 (*domains)[index].type = LTTNG_DOMAIN_UST;
1935                 index++;
1936         }
1937
1938         return nb_dom;
1939
1940 error:
1941         /* Return negative value to differentiate return code */
1942         return -ret;
1943 }
1944
1945
1946 /*
1947  * Command LTTNG_LIST_CHANNELS processed by the client thread.
1948  */
1949 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
1950                 struct lttng_channel **channels)
1951 {
1952         int ret;
1953         ssize_t nb_chan = 0;
1954
1955         switch (domain) {
1956         case LTTNG_DOMAIN_KERNEL:
1957                 if (session->kernel_session != NULL) {
1958                         nb_chan = session->kernel_session->channel_count;
1959                 }
1960                 DBG3("Number of kernel channels %zd", nb_chan);
1961                 if (nb_chan <= 0) {
1962                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1963                 }
1964                 break;
1965         case LTTNG_DOMAIN_UST:
1966                 if (session->ust_session != NULL) {
1967                         nb_chan = lttng_ht_get_count(
1968                                         session->ust_session->domain_global.channels);
1969                 }
1970                 DBG3("Number of UST global channels %zd", nb_chan);
1971                 if (nb_chan <= 0) {
1972                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1973                 }
1974                 break;
1975         default:
1976                 *channels = NULL;
1977                 ret = LTTNG_ERR_UND;
1978                 goto error;
1979         }
1980
1981         if (nb_chan > 0) {
1982                 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
1983                 if (*channels == NULL) {
1984                         ret = LTTNG_ERR_FATAL;
1985                         goto error;
1986                 }
1987
1988                 list_lttng_channels(domain, session, *channels);
1989         } else {
1990                 *channels = NULL;
1991                 /* Ret value was set in the domain switch case */
1992                 goto error;
1993         }
1994
1995         return nb_chan;
1996
1997 error:
1998         /* Return negative value to differentiate return code */
1999         return -ret;
2000 }
2001
2002 /*
2003  * Command LTTNG_LIST_EVENTS processed by the client thread.
2004  */
2005 ssize_t cmd_list_events(int domain, struct ltt_session *session,
2006                 char *channel_name, struct lttng_event **events)
2007 {
2008         int ret = 0;
2009         ssize_t nb_event = 0;
2010
2011         switch (domain) {
2012         case LTTNG_DOMAIN_KERNEL:
2013                 if (session->kernel_session != NULL) {
2014                         nb_event = list_lttng_kernel_events(channel_name,
2015                                         session->kernel_session, events);
2016                 }
2017                 break;
2018         case LTTNG_DOMAIN_UST:
2019         {
2020                 if (session->ust_session != NULL) {
2021                         nb_event = list_lttng_ust_global_events(channel_name,
2022                                         &session->ust_session->domain_global, events);
2023                 }
2024                 break;
2025         }
2026         default:
2027                 ret = LTTNG_ERR_UND;
2028                 goto error;
2029         }
2030
2031         return nb_event;
2032
2033 error:
2034         /* Return negative value to differentiate return code */
2035         return -ret;
2036 }
2037
2038 /*
2039  * Using the session list, filled a lttng_session array to send back to the
2040  * client for session listing.
2041  *
2042  * The session list lock MUST be acquired before calling this function. Use
2043  * session_lock_list() and session_unlock_list().
2044  */
2045 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2046                 gid_t gid)
2047 {
2048         int ret;
2049         unsigned int i = 0;
2050         struct ltt_session *session;
2051         struct ltt_session_list *list = session_get_list();
2052
2053         DBG("Getting all available session for UID %d GID %d",
2054                         uid, gid);
2055         /*
2056          * Iterate over session list and append data after the control struct in
2057          * the buffer.
2058          */
2059         cds_list_for_each_entry(session, &list->head, list) {
2060                 /*
2061                  * Only list the sessions the user can control.
2062                  */
2063                 if (!session_access_ok(session, uid, gid)) {
2064                         continue;
2065                 }
2066
2067                 struct ltt_kernel_session *ksess = session->kernel_session;
2068                 struct ltt_ust_session *usess = session->ust_session;
2069
2070                 if (session->consumer->type == CONSUMER_DST_NET ||
2071                                 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2072                                 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2073                         ret = build_network_session_path(sessions[i].path,
2074                                         sizeof(session[i].path), session);
2075                 } else {
2076                         ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2077                                         session->consumer->dst.trace_path);
2078                 }
2079                 if (ret < 0) {
2080                         PERROR("snprintf session path");
2081                         continue;
2082                 }
2083
2084                 strncpy(sessions[i].name, session->name, NAME_MAX);
2085                 sessions[i].name[NAME_MAX - 1] = '\0';
2086                 sessions[i].enabled = session->enabled;
2087                 i++;
2088         }
2089 }
2090
2091 /*
2092  * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
2093  * ready for trace analysis (or anykind of reader) or else 1 for pending data.
2094  */
2095 int cmd_data_pending(struct ltt_session *session)
2096 {
2097         int ret;
2098         struct ltt_kernel_session *ksess = session->kernel_session;
2099         struct ltt_ust_session *usess = session->ust_session;
2100
2101         assert(session);
2102
2103         /* Session MUST be stopped to ask for data availability. */
2104         if (session->enabled) {
2105                 ret = LTTNG_ERR_SESSION_STARTED;
2106                 goto error;
2107         }
2108
2109         if (ksess && ksess->consumer) {
2110                 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
2111                 if (ret == 1) {
2112                         /* Data is still being extracted for the kernel. */
2113                         goto error;
2114                 }
2115         }
2116
2117         if (usess && usess->consumer) {
2118                 ret = consumer_is_data_pending(usess->id, usess->consumer);
2119                 if (ret == 1) {
2120                         /* Data is still being extracted for the kernel. */
2121                         goto error;
2122                 }
2123         }
2124
2125         /* Data is ready to be read by a viewer */
2126         ret = 0;
2127
2128 error:
2129         return ret;
2130 }
2131
2132 /*
2133  * Init command subsystem.
2134  */
2135 void cmd_init(void)
2136 {
2137         /*
2138          * Set network sequence index to 1 for streams to match a relayd
2139          * socket on the consumer side.
2140          */
2141         pthread_mutex_lock(&relayd_net_seq_idx_lock);
2142         relayd_net_seq_idx = 1;
2143         pthread_mutex_unlock(&relayd_net_seq_idx_lock);
2144
2145         DBG("Command subsystem initialized");
2146 }