lttng-sessiond/main.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the Free
   7  * Software Foundation; only version 2 of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <fcntl.h>
  21 #include <getopt.h>
  22 #include <grp.h>
  23 #include <limits.h>
  24 #include <pthread.h>
  25 #include <semaphore.h>
  26 #include <signal.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <sys/mman.h>
  31 #include <sys/mount.h>
  32 #include <sys/resource.h>
  33 #include <sys/socket.h>
  34 #include <sys/stat.h>
  35 #include <sys/types.h>
  36 #include <sys/wait.h>
  37 #include <urcu/futex.h>
  38 #include <unistd.h>
  39 #include <config.h>
  40
  41 #include <lttng-consumerd.h>
  42 #include <lttng-sessiond-comm.h>
  43 #include <lttng/lttng-consumer.h>
  44
  45 #include <lttngerr.h>
  46
  47 #include "channel.h"
  48 #include "compat/poll.h"
  49 #include "context.h"
  50 #include "event.h"
  51 #include "futex.h"
  52 #include "hashtable.h"
  53 #include "kernel-ctl.h"
  54 #include "lttng-sessiond.h"
  55 #include "shm.h"
  56 #include "ust-app.h"
  57 #include "ust-ctl.h"
  58 #include "utils.h"
  59
  60 struct consumer_data {
  61         enum lttng_consumer_type type;
  62
  63         pthread_t thread;       /* Worker thread interacting with the consumer */
  64         sem_t sem;
  65
  66         /* Mutex to control consumerd pid assignation */
  67         pthread_mutex_t pid_mutex;
  68         pid_t pid;
  69
  70         int err_sock;
  71         int cmd_sock;
  72
  73         /* consumer error and command Unix socket path */
  74         char err_unix_sock_path[PATH_MAX];
  75         char cmd_unix_sock_path[PATH_MAX];
  76 };
  77
  78 /* Const values */
  79 const char default_home_dir[] = DEFAULT_HOME_DIR;
  80 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
  81 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
  82 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
  83
  84 /* Variables */
  85 int opt_verbose;    /* Not static for lttngerr.h */
  86 int opt_verbose_consumer;    /* Not static for lttngerr.h */
  87 int opt_quiet;      /* Not static for lttngerr.h */
  88
  89 const char *progname;
  90 const char *opt_tracing_group;
  91 static int opt_sig_parent;
  92 static int opt_daemon;
  93 static int is_root;                     /* Set to 1 if the daemon is running as root */
  94 static pid_t ppid;          /* Parent PID for --sig-parent option */
  95
  96 /* Consumer daemon specific control data */
  97 static struct consumer_data kconsumer_data = {
  98         .type = LTTNG_CONSUMER_KERNEL,
  99 };
 100 static struct consumer_data ustconsumer_data = {
 101         .type = LTTNG_CONSUMER_UST,
 102 };
 103
 104 static int dispatch_thread_exit;
 105
 106 /* Global application Unix socket path */
 107 static char apps_unix_sock_path[PATH_MAX];
 108 /* Global client Unix socket path */
 109 static char client_unix_sock_path[PATH_MAX];
 110 /* global wait shm path for UST */
 111 static char wait_shm_path[PATH_MAX];
 112
 113 /* Sockets and FDs */
 114 static int client_sock;
 115 static int apps_sock;
 116 static int kernel_tracer_fd;
 117 static int kernel_poll_pipe[2];
 118
 119 /*
 120  * Quit pipe for all threads. This permits a single cancellation point
 121  * for all threads when receiving an event on the pipe.
 122  */
 123 static int thread_quit_pipe[2];
 124
 125 /*
 126  * This pipe is used to inform the thread managing application communication
 127  * that a command is queued and ready to be processed.
 128  */
 129 static int apps_cmd_pipe[2];
 130
 131 /* Pthread, Mutexes and Semaphores */
 132 static pthread_t apps_thread;
 133 static pthread_t reg_apps_thread;
 134 static pthread_t client_thread;
 135 static pthread_t kernel_thread;
 136 static pthread_t dispatch_thread;
 137
 138
 139 /*
 140  * UST registration command queue. This queue is tied with a futex and uses a N
 141  * wakers / 1 waiter implemented and detailed in futex.c/.h
 142  *
 143  * The thread_manage_apps and thread_dispatch_ust_registration interact with
 144  * this queue and the wait/wake scheme.
 145  */
 146 static struct ust_cmd_queue ust_cmd_queue;
 147
 148 /*
 149  * Pointer initialized before thread creation.
 150  *
 151  * This points to the tracing session list containing the session count and a
 152  * mutex lock. The lock MUST be taken if you iterate over the list. The lock
 153  * MUST NOT be taken if you call a public function in session.c.
 154  *
 155  * The lock is nested inside the structure: session_list_ptr->lock. Please use
 156  * session_lock_list and session_unlock_list for lock acquisition.
 157  */
 158 static struct ltt_session_list *session_list_ptr;
 159
 160 /*
 161  * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
 162  */
 163 static int create_thread_poll_set(struct lttng_poll_event *events,
 164                 unsigned int size)
 165 {
 166         int ret;
 167
 168         if (events == NULL || size == 0) {
 169                 ret = -1;
 170                 goto error;
 171         }
 172
 173         ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
 174         if (ret < 0) {
 175                 goto error;
 176         }
 177
 178         /* Add quit pipe */
 179         ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
 180         if (ret < 0) {
 181                 goto error;
 182         }
 183
 184         return 0;
 185
 186 error:
 187         return ret;
 188 }
 189
 190 /*
 191  * Check if the thread quit pipe was triggered.
 192  *
 193  * Return 1 if it was triggered else 0;
 194  */
 195 static int check_thread_quit_pipe(int fd, uint32_t events)
 196 {
 197         if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
 198                 return 1;
 199         }
 200
 201         return 0;
 202 }
 203
 204 /*
 205  * Remove modules in reverse load order.
 206  */
 207 static int modprobe_remove_kernel_modules(void)
 208 {
 209         int ret = 0, i;
 210         char modprobe[256];
 211
 212         for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
 213                 ret = snprintf(modprobe, sizeof(modprobe),
 214                                 "/sbin/modprobe -r -q %s",
 215                                 kernel_modules_list[i].name);
 216                 if (ret < 0) {
 217                         perror("snprintf modprobe -r");
 218                         goto error;
 219                 }
 220                 modprobe[sizeof(modprobe) - 1] = '\0';
 221                 ret = system(modprobe);
 222                 if (ret == -1) {
 223                         ERR("Unable to launch modprobe -r for module %s",
 224                                         kernel_modules_list[i].name);
 225                 } else if (kernel_modules_list[i].required
 226                                 && WEXITSTATUS(ret) != 0) {
 227                         ERR("Unable to remove module %s",
 228                                         kernel_modules_list[i].name);
 229                 } else {
 230                         DBG("Modprobe removal successful %s",
 231                                         kernel_modules_list[i].name);
 232                 }
 233         }
 234
 235 error:
 236         return ret;
 237 }
 238
 239 /*
 240  * Return group ID of the tracing group or -1 if not found.
 241  */
 242 static gid_t allowed_group(void)
 243 {
 244         struct group *grp;
 245
 246         if (opt_tracing_group) {
 247                 grp = getgrnam(opt_tracing_group);
 248         } else {
 249                 grp = getgrnam(default_tracing_group);
 250         }
 251         if (!grp) {
 252                 return -1;
 253         } else {
 254                 return grp->gr_gid;
 255         }
 256 }
 257
 258 /*
 259  * Init thread quit pipe.
 260  *
 261  * Return -1 on error or 0 if all pipes are created.
 262  */
 263 static int init_thread_quit_pipe(void)
 264 {
 265         int ret;
 266
 267         ret = pipe2(thread_quit_pipe, O_CLOEXEC);
 268         if (ret < 0) {
 269                 perror("thread quit pipe");
 270                 goto error;
 271         }
 272
 273 error:
 274         return ret;
 275 }
 276
 277 /*
 278  * Complete teardown of a kernel session. This free all data structure related
 279  * to a kernel session and update counter.
 280  */
 281 static void teardown_kernel_session(struct ltt_session *session)
 282 {
 283         if (session->kernel_session != NULL) {
 284                 DBG("Tearing down kernel session");
 285
 286                 /*
 287                  * If a custom kernel consumer was registered, close the socket before
 288                  * tearing down the complete kernel session structure
 289                  */
 290                 if (session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
 291                         lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
 292                 }
 293
 294                 trace_kernel_destroy_session(session->kernel_session);
 295                 /* Extra precaution */
 296                 session->kernel_session = NULL;
 297         }
 298 }
 299
 300 /*
 301  * Complete teardown of all UST sessions. This will free everything on his path
 302  * and destroy the core essence of all ust sessions :)
 303  */
 304 static void teardown_ust_session(struct ltt_session *session)
 305 {
 306         DBG("Tearing down UST session(s)");
 307
 308         trace_ust_destroy_session(session->ust_session);
 309 }
 310
 311 /*
 312  * Stop all threads by closing the thread quit pipe.
 313  */
 314 static void stop_threads(void)
 315 {
 316         int ret;
 317
 318         /* Stopping all threads */
 319         DBG("Terminating all threads");
 320         ret = notify_thread_pipe(thread_quit_pipe[1]);
 321         if (ret < 0) {
 322                 ERR("write error on thread quit pipe");
 323         }
 324
 325         /* Dispatch thread */
 326         dispatch_thread_exit = 1;
 327         futex_nto1_wake(&ust_cmd_queue.futex);
 328 }
 329
 330 /*
 331  * Cleanup the daemon
 332  */
 333 static void cleanup(void)
 334 {
 335         int ret;
 336         char *cmd;
 337         struct ltt_session *sess, *stmp;
 338
 339         DBG("Cleaning up");
 340
 341         /* <fun> */
 342         MSG("%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
 343                 "Matthew, BEET driven development works!%c[%dm",
 344                 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
 345         /* </fun> */
 346
 347         if (is_root) {
 348                 DBG("Removing %s directory", LTTNG_RUNDIR);
 349                 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
 350                 if (ret < 0) {
 351                         ERR("asprintf failed. Something is really wrong!");
 352                 }
 353
 354                 /* Remove lttng run directory */
 355                 ret = system(cmd);
 356                 if (ret < 0) {
 357                         ERR("Unable to clean " LTTNG_RUNDIR);
 358                 }
 359         }
 360
 361         DBG("Cleaning up all session");
 362
 363         /* Destroy session list mutex */
 364         if (session_list_ptr != NULL) {
 365                 pthread_mutex_destroy(&session_list_ptr->lock);
 366
 367                 /* Cleanup ALL session */
 368                 cds_list_for_each_entry_safe(sess, stmp,
 369                                 &session_list_ptr->head, list) {
 370                         teardown_kernel_session(sess);
 371                         teardown_ust_session(sess);
 372                         free(sess);
 373                 }
 374         }
 375
 376         DBG("Closing all UST sockets");
 377         ust_app_clean_list();
 378
 379         pthread_mutex_destroy(&kconsumer_data.pid_mutex);
 380
 381         DBG("Closing kernel fd");
 382         close(kernel_tracer_fd);
 383
 384         if (is_root) {
 385                 DBG("Unloading kernel modules");
 386                 modprobe_remove_kernel_modules();
 387         }
 388
 389         close(thread_quit_pipe[0]);
 390         close(thread_quit_pipe[1]);
 391 }
 392
 393 /*
 394  * Send data on a unix socket using the liblttsessiondcomm API.
 395  *
 396  * Return lttcomm error code.
 397  */
 398 static int send_unix_sock(int sock, void *buf, size_t len)
 399 {
 400         /* Check valid length */
 401         if (len <= 0) {
 402                 return -1;
 403         }
 404
 405         return lttcomm_send_unix_sock(sock, buf, len);
 406 }
 407
 408 /*
 409  * Free memory of a command context structure.
 410  */
 411 static void clean_command_ctx(struct command_ctx **cmd_ctx)
 412 {
 413         DBG("Clean command context structure");
 414         if (*cmd_ctx) {
 415                 if ((*cmd_ctx)->llm) {
 416                         free((*cmd_ctx)->llm);
 417                 }
 418                 if ((*cmd_ctx)->lsm) {
 419                         free((*cmd_ctx)->lsm);
 420                 }
 421                 free(*cmd_ctx);
 422                 *cmd_ctx = NULL;
 423         }
 424 }
 425
 426 /*
 427  * Send all stream fds of kernel channel to the consumer.
 428  */
 429 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
 430                 int sock, struct ltt_kernel_channel *channel)
 431 {
 432         int ret;
 433         struct ltt_kernel_stream *stream;
 434         struct lttcomm_consumer_msg lkm;
 435
 436         DBG("Sending streams of channel %s to kernel consumer",
 437                         channel->channel->name);
 438
 439         /* Send channel */
 440         lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
 441         lkm.u.channel.channel_key = channel->fd;
 442         lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
 443         lkm.u.channel.mmap_len = 0;     /* for kernel */
 444         DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
 445         ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
 446         if (ret < 0) {
 447                 perror("send consumer channel");
 448                 goto error;
 449         }
 450
 451         /* Send streams */
 452         cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
 453                 if (!stream->fd) {
 454                         continue;
 455                 }
 456                 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
 457                 lkm.u.stream.channel_key = channel->fd;
 458                 lkm.u.stream.stream_key = stream->fd;
 459                 lkm.u.stream.state = stream->state;
 460                 lkm.u.stream.output = channel->channel->attr.output;
 461                 lkm.u.stream.mmap_len = 0;      /* for kernel */
 462                 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
 463                 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
 464                 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
 465                 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
 466                 if (ret < 0) {
 467                         perror("send consumer stream");
 468                         goto error;
 469                 }
 470                 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
 471                 if (ret < 0) {
 472                         perror("send consumer stream ancillary data");
 473                         goto error;
 474                 }
 475         }
 476
 477         DBG("consumer channel streams sent");
 478
 479         return 0;
 480
 481 error:
 482         return ret;
 483 }
 484
 485 /*
 486  * Send all stream fds of the kernel session to the consumer.
 487  */
 488 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
 489                 struct ltt_kernel_session *session)
 490 {
 491         int ret;
 492         struct ltt_kernel_channel *chan;
 493         struct lttcomm_consumer_msg lkm;
 494         int sock = session->consumer_fd;
 495
 496         DBG("Sending metadata stream fd");
 497
 498         /* Extra protection. It's NOT supposed to be set to 0 at this point */
 499         if (session->consumer_fd == 0) {
 500                 session->consumer_fd = consumer_data->cmd_sock;
 501         }
 502
 503         if (session->metadata_stream_fd != 0) {
 504                 /* Send metadata channel fd */
 505                 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
 506                 lkm.u.channel.channel_key = session->metadata->fd;
 507                 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
 508                 lkm.u.channel.mmap_len = 0;     /* for kernel */
 509                 DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
 510                 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
 511                 if (ret < 0) {
 512                         perror("send consumer channel");
 513                         goto error;
 514                 }
 515
 516                 /* Send metadata stream fd */
 517                 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
 518                 lkm.u.stream.channel_key = session->metadata->fd;
 519                 lkm.u.stream.stream_key = session->metadata_stream_fd;
 520                 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
 521                 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 522                 lkm.u.stream.mmap_len = 0;      /* for kernel */
 523                 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
 524                 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
 525                 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
 526                 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
 527                 if (ret < 0) {
 528                         perror("send consumer stream");
 529                         goto error;
 530                 }
 531                 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
 532                 if (ret < 0) {
 533                         perror("send consumer stream");
 534                         goto error;
 535                 }
 536         }
 537
 538         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
 539                 ret = send_kconsumer_channel_streams(consumer_data, sock, chan);
 540                 if (ret < 0) {
 541                         goto error;
 542                 }
 543         }
 544
 545         DBG("consumer fds (metadata and channel streams) sent");
 546
 547         return 0;
 548
 549 error:
 550         return ret;
 551 }
 552
 553 /*
 554  * Notify UST applications using the shm mmap futex.
 555  */
 556 static int notify_ust_apps(int active)
 557 {
 558         char *wait_shm_mmap;
 559
 560         DBG("Notifying applications of session daemon state: %d", active);
 561
 562         /* See shm.c for this call implying mmap, shm and futex calls */
 563         wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
 564         if (wait_shm_mmap == NULL) {
 565                 goto error;
 566         }
 567
 568         /* Wake waiting process */
 569         futex_wait_update((int32_t *) wait_shm_mmap, active);
 570
 571         /* Apps notified successfully */
 572         return 0;
 573
 574 error:
 575         return -1;
 576 }
 577
 578 /*
 579  * Setup the outgoing data buffer for the response (llm) by allocating the
 580  * right amount of memory and copying the original information from the lsm
 581  * structure.
 582  *
 583  * Return total size of the buffer pointed by buf.
 584  */
 585 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
 586 {
 587         int ret, buf_size;
 588
 589         buf_size = size;
 590
 591         cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
 592         if (cmd_ctx->llm == NULL) {
 593                 perror("malloc");
 594                 ret = -ENOMEM;
 595                 goto error;
 596         }
 597
 598         /* Copy common data */
 599         cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
 600         cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
 601
 602         cmd_ctx->llm->data_size = size;
 603         cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
 604
 605         return buf_size;
 606
 607 error:
 608         return ret;
 609 }
 610
 611 /*
 612  * Update the kernel poll set of all channel fd available over all tracing
 613  * session. Add the wakeup pipe at the end of the set.
 614  */
 615 static int update_kernel_poll(struct lttng_poll_event *events)
 616 {
 617         int ret;
 618         struct ltt_session *session;
 619         struct ltt_kernel_channel *channel;
 620
 621         DBG("Updating kernel poll set");
 622
 623         session_lock_list();
 624         cds_list_for_each_entry(session, &session_list_ptr->head, list) {
 625                 session_lock(session);
 626                 if (session->kernel_session == NULL) {
 627                         session_unlock(session);
 628                         continue;
 629                 }
 630
 631                 cds_list_for_each_entry(channel,
 632                                 &session->kernel_session->channel_list.head, list) {
 633                         /* Add channel fd to the kernel poll set */
 634                         ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
 635                         if (ret < 0) {
 636                                 session_unlock(session);
 637                                 goto error;
 638                         }
 639                         DBG("Channel fd %d added to kernel set", channel->fd);
 640                 }
 641                 session_unlock(session);
 642         }
 643         session_unlock_list();
 644
 645         return 0;
 646
 647 error:
 648         session_unlock_list();
 649         return -1;
 650 }
 651
 652 /*
 653  * Find the channel fd from 'fd' over all tracing session. When found, check
 654  * for new channel stream and send those stream fds to the kernel consumer.
 655  *
 656  * Useful for CPU hotplug feature.
 657  */
 658 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
 659 {
 660         int ret = 0;
 661         struct ltt_session *session;
 662         struct ltt_kernel_channel *channel;
 663
 664         DBG("Updating kernel streams for channel fd %d", fd);
 665
 666         session_lock_list();
 667         cds_list_for_each_entry(session, &session_list_ptr->head, list) {
 668                 session_lock(session);
 669                 if (session->kernel_session == NULL) {
 670                         session_unlock(session);
 671                         continue;
 672                 }
 673
 674                 /* This is not suppose to be 0 but this is an extra security check */
 675                 if (session->kernel_session->consumer_fd == 0) {
 676                         session->kernel_session->consumer_fd = consumer_data->cmd_sock;
 677                 }
 678
 679                 cds_list_for_each_entry(channel,
 680                                 &session->kernel_session->channel_list.head, list) {
 681                         if (channel->fd == fd) {
 682                                 DBG("Channel found, updating kernel streams");
 683                                 ret = kernel_open_channel_stream(channel);
 684                                 if (ret < 0) {
 685                                         goto error;
 686                                 }
 687
 688                                 /*
 689                                  * Have we already sent fds to the consumer? If yes, it means
 690                                  * that tracing is started so it is safe to send our updated
 691                                  * stream fds.
 692                                  */
 693                                 if (session->kernel_session->consumer_fds_sent == 1) {
 694                                         ret = send_kconsumer_channel_streams(consumer_data,
 695                                                         session->kernel_session->consumer_fd, channel);
 696                                         if (ret < 0) {
 697                                                 goto error;
 698                                         }
 699                                 }
 700                                 goto error;
 701                         }
 702                 }
 703                 session_unlock(session);
 704         }
 705         session_unlock_list();
 706         return ret;
 707
 708 error:
 709         session_unlock(session);
 710         session_unlock_list();
 711         return ret;
 712 }
 713
 714 /*
 715  * For each tracing session, update newly registered apps.
 716  */
 717 static void update_ust_app(int app_sock)
 718 {
 719         struct ltt_session *sess, *stmp;
 720
 721         /* For all tracing session(s) */
 722         cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
 723                 ust_app_global_update(sess->ust_session, app_sock);
 724         }
 725 }
 726
 727 /*
 728  * This thread manage event coming from the kernel.
 729  *
 730  * Features supported in this thread:
 731  *    -) CPU Hotplug
 732  */
 733 static void *thread_manage_kernel(void *data)
 734 {
 735         int ret, i, pollfd, update_poll_flag = 1;
 736         uint32_t revents, nb_fd;
 737         char tmp;
 738         struct lttng_poll_event events;
 739
 740         DBG("Thread manage kernel started");
 741
 742         ret = create_thread_poll_set(&events, 2);
 743         if (ret < 0) {
 744                 goto error;
 745         }
 746
 747         ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
 748         if (ret < 0) {
 749                 goto error;
 750         }
 751
 752         while (1) {
 753                 if (update_poll_flag == 1) {
 754                         /*
 755                          * Reset number of fd in the poll set. Always 2 since there is the thread
 756                          * quit pipe and the kernel pipe.
 757                          */
 758                         events.nb_fd = 2;
 759
 760                         ret = update_kernel_poll(&events);
 761                         if (ret < 0) {
 762                                 goto error;
 763                         }
 764                         update_poll_flag = 0;
 765                 }
 766
 767                 nb_fd = LTTNG_POLL_GETNB(&events);
 768
 769                 DBG("Thread kernel polling on %d fds", nb_fd);
 770
 771                 /* Zeroed the poll events */
 772                 lttng_poll_reset(&events);
 773
 774                 /* Poll infinite value of time */
 775                 ret = lttng_poll_wait(&events, -1);
 776                 if (ret < 0) {
 777                         goto error;
 778                 } else if (ret == 0) {
 779                         /* Should not happen since timeout is infinite */
 780                         ERR("Return value of poll is 0 with an infinite timeout.\n"
 781                                 "This should not have happened! Continuing...");
 782                         continue;
 783                 }
 784
 785                 for (i = 0; i < nb_fd; i++) {
 786                         /* Fetch once the poll data */
 787                         revents = LTTNG_POLL_GETEV(&events, i);
 788                         pollfd = LTTNG_POLL_GETFD(&events, i);
 789
 790                         /* Thread quit pipe has been closed. Killing thread. */
 791                         ret = check_thread_quit_pipe(pollfd, revents);
 792                         if (ret) {
 793                                 goto error;
 794                         }
 795
 796                         /* Check for data on kernel pipe */
 797                         if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
 798                                 ret = read(kernel_poll_pipe[0], &tmp, 1);
 799                                 update_poll_flag = 1;
 800                                 continue;
 801                         } else {
 802                                 /*
 803                                  * New CPU detected by the kernel. Adding kernel stream to
 804                                  * kernel session and updating the kernel consumer
 805                                  */
 806                                 if (revents & LPOLLIN) {
 807                                         ret = update_kernel_stream(&kconsumer_data, pollfd);
 808                                         if (ret < 0) {
 809                                                 continue;
 810                                         }
 811                                         break;
 812                                         /*
 813                                          * TODO: We might want to handle the LPOLLERR | LPOLLHUP
 814                                          * and unregister kernel stream at this point.
 815                                          */
 816                                 }
 817                         }
 818                 }
 819         }
 820
 821 error:
 822         DBG("Kernel thread dying");
 823         close(kernel_poll_pipe[0]);
 824         close(kernel_poll_pipe[1]);
 825
 826         lttng_poll_clean(&events);
 827
 828         return NULL;
 829 }
 830
 831 /*
 832  * This thread manage the consumer error sent back to the session daemon.
 833  */
 834 static void *thread_manage_consumer(void *data)
 835 {
 836         int sock = 0, i, ret, pollfd;
 837         uint32_t revents, nb_fd;
 838         enum lttcomm_return_code code;
 839         struct lttng_poll_event events;
 840         struct consumer_data *consumer_data = data;
 841
 842         DBG("[thread] Manage consumer started");
 843
 844         ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
 845         if (ret < 0) {
 846                 goto error;
 847         }
 848
 849         /*
 850          * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
 851          * Nothing more will be added to this poll set.
 852          */
 853         ret = create_thread_poll_set(&events, 2);
 854         if (ret < 0) {
 855                 goto error;
 856         }
 857
 858         ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
 859         if (ret < 0) {
 860                 goto error;
 861         }
 862
 863         nb_fd = LTTNG_POLL_GETNB(&events);
 864
 865         /* Inifinite blocking call, waiting for transmission */
 866         ret = lttng_poll_wait(&events, -1);
 867         if (ret < 0) {
 868                 goto error;
 869         }
 870
 871         for (i = 0; i < nb_fd; i++) {
 872                 /* Fetch once the poll data */
 873                 revents = LTTNG_POLL_GETEV(&events, i);
 874                 pollfd = LTTNG_POLL_GETFD(&events, i);
 875
 876                 /* Thread quit pipe has been closed. Killing thread. */
 877                 ret = check_thread_quit_pipe(pollfd, revents);
 878                 if (ret) {
 879                         goto error;
 880                 }
 881
 882                 /* Event on the registration socket */
 883                 if (pollfd == consumer_data->err_sock) {
 884                         if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 885                                 ERR("consumer err socket poll error");
 886                                 goto error;
 887                         }
 888                 }
 889         }
 890
 891         sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
 892         if (sock < 0) {
 893                 goto error;
 894         }
 895
 896         DBG2("Receiving code from consumer err_sock");
 897
 898         /* Getting status code from kconsumerd */
 899         ret = lttcomm_recv_unix_sock(sock, &code,
 900                         sizeof(enum lttcomm_return_code));
 901         if (ret <= 0) {
 902                 goto error;
 903         }
 904
 905         if (code == CONSUMERD_COMMAND_SOCK_READY) {
 906                 consumer_data->cmd_sock =
 907                         lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
 908                 if (consumer_data->cmd_sock < 0) {
 909                         sem_post(&consumer_data->sem);
 910                         PERROR("consumer connect");
 911                         goto error;
 912                 }
 913                 /* Signal condition to tell that the kconsumerd is ready */
 914                 sem_post(&consumer_data->sem);
 915                 DBG("consumer command socket ready");
 916         } else {
 917                 ERR("consumer error when waiting for SOCK_READY : %s",
 918                                 lttcomm_get_readable_code(-code));
 919                 goto error;
 920         }
 921
 922         /* Remove the kconsumerd error sock since we've established a connexion */
 923         ret = lttng_poll_del(&events, consumer_data->err_sock);
 924         if (ret < 0) {
 925                 goto error;
 926         }
 927
 928         ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
 929         if (ret < 0) {
 930                 goto error;
 931         }
 932
 933         /* Update number of fd */
 934         nb_fd = LTTNG_POLL_GETNB(&events);
 935
 936         /* Inifinite blocking call, waiting for transmission */
 937         ret = lttng_poll_wait(&events, -1);
 938         if (ret < 0) {
 939                 goto error;
 940         }
 941
 942         for (i = 0; i < nb_fd; i++) {
 943                 /* Fetch once the poll data */
 944                 revents = LTTNG_POLL_GETEV(&events, i);
 945                 pollfd = LTTNG_POLL_GETFD(&events, i);
 946
 947                 /* Thread quit pipe has been closed. Killing thread. */
 948                 ret = check_thread_quit_pipe(pollfd, revents);
 949                 if (ret) {
 950                         goto error;
 951                 }
 952
 953                 /* Event on the kconsumerd socket */
 954                 if (pollfd == sock) {
 955                         if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 956                                 ERR("consumer err socket second poll error");
 957                                 goto error;
 958                         }
 959                 }
 960         }
 961
 962         /* Wait for any kconsumerd error */
 963         ret = lttcomm_recv_unix_sock(sock, &code,
 964                         sizeof(enum lttcomm_return_code));
 965         if (ret <= 0) {
 966                 ERR("consumer closed the command socket");
 967                 goto error;
 968         }
 969
 970         ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
 971
 972 error:
 973         DBG("consumer thread dying");
 974         close(consumer_data->err_sock);
 975         close(consumer_data->cmd_sock);
 976         close(sock);
 977
 978         unlink(consumer_data->err_unix_sock_path);
 979         unlink(consumer_data->cmd_unix_sock_path);
 980         consumer_data->pid = 0;
 981
 982         lttng_poll_clean(&events);
 983
 984         return NULL;
 985 }
 986
 987 /*
 988  * This thread manage application communication.
 989  */
 990 static void *thread_manage_apps(void *data)
 991 {
 992         int i, ret, pollfd;
 993         uint32_t revents, nb_fd;
 994         struct ust_command ust_cmd;
 995         struct lttng_poll_event events;
 996
 997         DBG("[thread] Manage application started");
 998
 999         rcu_register_thread();
1000         rcu_thread_online();
1001
1002         ret = create_thread_poll_set(&events, 2);
1003         if (ret < 0) {
1004                 goto error;
1005         }
1006
1007         ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1008         if (ret < 0) {
1009                 goto error;
1010         }
1011
1012         while (1) {
1013                 /* Zeroed the events structure */
1014                 lttng_poll_reset(&events);
1015
1016                 nb_fd = LTTNG_POLL_GETNB(&events);
1017
1018                 DBG("Apps thread polling on %d fds", nb_fd);
1019
1020                 /* Inifinite blocking call, waiting for transmission */
1021                 ret = lttng_poll_wait(&events, -1);
1022                 if (ret < 0) {
1023                         goto error;
1024                 }
1025
1026                 for (i = 0; i < nb_fd; i++) {
1027                         /* Fetch once the poll data */
1028                         revents = LTTNG_POLL_GETEV(&events, i);
1029                         pollfd = LTTNG_POLL_GETFD(&events, i);
1030
1031                         /* Thread quit pipe has been closed. Killing thread. */
1032                         ret = check_thread_quit_pipe(pollfd, revents);
1033                         if (ret) {
1034                                 goto error;
1035                         }
1036
1037                         /* Inspect the apps cmd pipe */
1038                         if (pollfd == apps_cmd_pipe[0]) {
1039                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1040                                         ERR("Apps command pipe error");
1041                                         goto error;
1042                                 } else if (revents & LPOLLIN) {
1043                                         /* Empty pipe */
1044                                         ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1045                                         if (ret < 0 || ret < sizeof(ust_cmd)) {
1046                                                 perror("read apps cmd pipe");
1047                                                 goto error;
1048                                         }
1049
1050                                         /* Register applicaton to the session daemon */
1051                                         ret = ust_app_register(&ust_cmd.reg_msg,
1052                                                         ust_cmd.sock);
1053                                         if (ret < 0) {
1054                                                 /* Only critical ENOMEM error can be returned here */
1055                                                 goto error;
1056                                         }
1057
1058                                         ret = ustctl_register_done(ust_cmd.sock);
1059                                         if (ret < 0) {
1060                                                 /*
1061                                                  * If the registration is not possible, we simply
1062                                                  * unregister the apps and continue
1063                                                  */
1064                                                 ust_app_unregister(ust_cmd.sock);
1065                                         } else {
1066                                                 /*
1067                                                  * We just need here to monitor the close of the UST
1068                                                  * socket and poll set monitor those by default.
1069                                                  */
1070                                                 ret = lttng_poll_add(&events, ust_cmd.sock, 0);
1071                                                 if (ret < 0) {
1072                                                         goto error;
1073                                                 }
1074
1075                                                 DBG("Apps with sock %d added to poll set",
1076                                                                 ust_cmd.sock);
1077                                         }
1078
1079                                         /*
1080                                          * Add channel(s) and event(s) to newly registered apps
1081                                          * from lttng global UST domain.
1082                                          */
1083                                         update_ust_app(ust_cmd.sock);
1084                                         break;
1085                                 }
1086                         } else {
1087                                 /*
1088                                  * At this point, we know that a registered application made
1089                                  * the event at poll_wait.
1090                                  */
1091                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1092                                         /* Removing from the poll set */
1093                                         ret = lttng_poll_del(&events, pollfd);
1094                                         if (ret < 0) {
1095                                                 goto error;
1096                                         }
1097
1098                                         /* Socket closed */
1099                                         ust_app_unregister(pollfd);
1100                                         break;
1101                                 }
1102                         }
1103                 }
1104         }
1105
1106 error:
1107         DBG("Application communication apps dying");
1108         close(apps_cmd_pipe[0]);
1109         close(apps_cmd_pipe[1]);
1110
1111         lttng_poll_clean(&events);
1112
1113         rcu_thread_offline();
1114         rcu_unregister_thread();
1115         return NULL;
1116 }
1117
1118 /*
1119  * Dispatch request from the registration threads to the application
1120  * communication thread.
1121  */
1122 static void *thread_dispatch_ust_registration(void *data)
1123 {
1124         int ret;
1125         struct cds_wfq_node *node;
1126         struct ust_command *ust_cmd = NULL;
1127
1128         DBG("[thread] Dispatch UST command started");
1129
1130         while (!dispatch_thread_exit) {
1131                 /* Atomically prepare the queue futex */
1132                 futex_nto1_prepare(&ust_cmd_queue.futex);
1133
1134                 do {
1135                         /* Dequeue command for registration */
1136                         node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1137                         if (node == NULL) {
1138                                 DBG("Woken up but nothing in the UST command queue");
1139                                 /* Continue thread execution */
1140                                 break;
1141                         }
1142
1143                         ust_cmd = caa_container_of(node, struct ust_command, node);
1144
1145                         DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1146                                         " gid:%d sock:%d name:%s (version %d.%d)",
1147                                         ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1148                                         ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1149                                         ust_cmd->sock, ust_cmd->reg_msg.name,
1150                                         ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1151                         /*
1152                          * Inform apps thread of the new application registration. This
1153                          * call is blocking so we can be assured that the data will be read
1154                          * at some point in time or wait to the end of the world :)
1155                          */
1156                         ret = write(apps_cmd_pipe[1], ust_cmd,
1157                                         sizeof(struct ust_command));
1158                         if (ret < 0) {
1159                                 perror("write apps cmd pipe");
1160                                 if (errno == EBADF) {
1161                                         /*
1162                                          * We can't inform the application thread to process
1163                                          * registration. We will exit or else application
1164                                          * registration will not occur and tracing will never
1165                                          * start.
1166                                          */
1167                                         goto error;
1168                                 }
1169                         }
1170                         free(ust_cmd);
1171                 } while (node != NULL);
1172
1173                 /* Futex wait on queue. Blocking call on futex() */
1174                 futex_nto1_wait(&ust_cmd_queue.futex);
1175         }
1176
1177 error:
1178         DBG("Dispatch thread dying");
1179         return NULL;
1180 }
1181
1182 /*
1183  * This thread manage application registration.
1184  */
1185 static void *thread_registration_apps(void *data)
1186 {
1187         int sock = 0, i, ret, pollfd;
1188         uint32_t revents, nb_fd;
1189         struct lttng_poll_event events;
1190         /*
1191          * Get allocated in this thread, enqueued to a global queue, dequeued and
1192          * freed in the manage apps thread.
1193          */
1194         struct ust_command *ust_cmd = NULL;
1195
1196         DBG("[thread] Manage application registration started");
1197
1198         ret = lttcomm_listen_unix_sock(apps_sock);
1199         if (ret < 0) {
1200                 goto error;
1201         }
1202
1203         /*
1204          * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1205          * more will be added to this poll set.
1206          */
1207         ret = create_thread_poll_set(&events, 2);
1208         if (ret < 0) {
1209                 goto error;
1210         }
1211
1212         /* Add the application registration socket */
1213         ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1214         if (ret < 0) {
1215                 goto error;
1216         }
1217
1218         /* Notify all applications to register */
1219         ret = notify_ust_apps(1);
1220         if (ret < 0) {
1221                 ERR("Failed to notify applications or create the wait shared memory.\n"
1222                         "Execution continues but there might be problem for already\n"
1223                         "running applications that wishes to register.");
1224         }
1225
1226         while (1) {
1227                 DBG("Accepting application registration");
1228
1229                 nb_fd = LTTNG_POLL_GETNB(&events);
1230
1231                 /* Inifinite blocking call, waiting for transmission */
1232                 ret = lttng_poll_wait(&events, -1);
1233                 if (ret < 0) {
1234                         goto error;
1235                 }
1236
1237                 for (i = 0; i < nb_fd; i++) {
1238                         /* Fetch once the poll data */
1239                         revents = LTTNG_POLL_GETEV(&events, i);
1240                         pollfd = LTTNG_POLL_GETFD(&events, i);
1241
1242                         /* Thread quit pipe has been closed. Killing thread. */
1243                         ret = check_thread_quit_pipe(pollfd, revents);
1244                         if (ret) {
1245                                 goto error;
1246                         }
1247
1248                         /* Event on the registration socket */
1249                         if (pollfd == apps_sock) {
1250                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1251                                         ERR("Register apps socket poll error");
1252                                         goto error;
1253                                 } else if (revents & LPOLLIN) {
1254                                         sock = lttcomm_accept_unix_sock(apps_sock);
1255                                         if (sock < 0) {
1256                                                 goto error;
1257                                         }
1258
1259                                         /* Create UST registration command for enqueuing */
1260                                         ust_cmd = malloc(sizeof(struct ust_command));
1261                                         if (ust_cmd == NULL) {
1262                                                 perror("ust command malloc");
1263                                                 goto error;
1264                                         }
1265
1266                                         /*
1267                                          * Using message-based transmissions to ensure we don't
1268                                          * have to deal with partially received messages.
1269                                          */
1270                                         ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1271                                                         sizeof(struct ust_register_msg));
1272                                         if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1273                                                 if (ret < 0) {
1274                                                         perror("lttcomm_recv_unix_sock register apps");
1275                                                 } else {
1276                                                         ERR("Wrong size received on apps register");
1277                                                 }
1278                                                 free(ust_cmd);
1279                                                 close(sock);
1280                                                 continue;
1281                                         }
1282
1283                                         ust_cmd->sock = sock;
1284
1285                                         DBG("UST registration received with pid:%d ppid:%d uid:%d"
1286                                                         " gid:%d sock:%d name:%s (version %d.%d)",
1287                                                         ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1288                                                         ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1289                                                         ust_cmd->sock, ust_cmd->reg_msg.name,
1290                                                         ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1291
1292                                         /*
1293                                          * Lock free enqueue the registration request. The red pill
1294                                          * has been taken! This apps will be part of the *system*.
1295                                          */
1296                                         cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1297
1298                                         /*
1299                                          * Wake the registration queue futex. Implicit memory
1300                                          * barrier with the exchange in cds_wfq_enqueue.
1301                                          */
1302                                         futex_nto1_wake(&ust_cmd_queue.futex);
1303                                 }
1304                         }
1305                 }
1306         }
1307
1308 error:
1309         DBG("UST Registration thread dying");
1310
1311         /* Notify that the registration thread is gone */
1312         notify_ust_apps(0);
1313
1314         close(apps_sock);
1315         close(sock);
1316         unlink(apps_unix_sock_path);
1317
1318         lttng_poll_clean(&events);
1319
1320         return NULL;
1321 }
1322
1323 /*
1324  * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1325  * exec or it will fails.
1326  */
1327 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1328 {
1329         int ret;
1330         struct timespec timeout;
1331
1332         timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1333         timeout.tv_nsec = 0;
1334
1335         /* Setup semaphore */
1336         ret = sem_init(&consumer_data->sem, 0, 0);
1337         if (ret < 0) {
1338                 PERROR("sem_init consumer semaphore");
1339                 goto error;
1340         }
1341
1342         ret = pthread_create(&consumer_data->thread, NULL,
1343                         thread_manage_consumer, consumer_data);
1344         if (ret != 0) {
1345                 PERROR("pthread_create consumer");
1346                 ret = -1;
1347                 goto error;
1348         }
1349
1350         /* Get time for sem_timedwait absolute timeout */
1351         ret = clock_gettime(CLOCK_REALTIME, &timeout);
1352         if (ret < 0) {
1353                 PERROR("clock_gettime spawn consumer");
1354                 /* Infinite wait for the kconsumerd thread to be ready */
1355                 ret = sem_wait(&consumer_data->sem);
1356         } else {
1357                 /* Normal timeout if the gettime was successful */
1358                 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1359                 ret = sem_timedwait(&consumer_data->sem, &timeout);
1360         }
1361
1362         if (ret < 0) {
1363                 if (errno == ETIMEDOUT) {
1364                         /*
1365                          * Call has timed out so we kill the kconsumerd_thread and return
1366                          * an error.
1367                          */
1368                         ERR("The consumer thread was never ready. Killing it");
1369                         ret = pthread_cancel(consumer_data->thread);
1370                         if (ret < 0) {
1371                                 PERROR("pthread_cancel consumer thread");
1372                         }
1373                 } else {
1374                         PERROR("semaphore wait failed consumer thread");
1375                 }
1376                 goto error;
1377         }
1378
1379         pthread_mutex_lock(&consumer_data->pid_mutex);
1380         if (consumer_data->pid == 0) {
1381                 ERR("Kconsumerd did not start");
1382                 pthread_mutex_unlock(&consumer_data->pid_mutex);
1383                 goto error;
1384         }
1385         pthread_mutex_unlock(&consumer_data->pid_mutex);
1386
1387         return 0;
1388
1389 error:
1390         return ret;
1391 }
1392
1393 /*
1394  * Join consumer thread
1395  */
1396 static int join_consumer_thread(struct consumer_data *consumer_data)
1397 {
1398         void *status;
1399         int ret;
1400
1401         if (consumer_data->pid != 0) {
1402                 ret = kill(consumer_data->pid, SIGTERM);
1403                 if (ret) {
1404                         ERR("Error killing consumer daemon");
1405                         return ret;
1406                 }
1407                 return pthread_join(consumer_data->thread, &status);
1408         } else {
1409                 return 0;
1410         }
1411 }
1412
1413 /*
1414  * Fork and exec a consumer daemon (consumerd).
1415  *
1416  * Return pid if successful else -1.
1417  */
1418 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1419 {
1420         int ret;
1421         pid_t pid;
1422         const char *verbosity;
1423
1424         DBG("Spawning consumerd");
1425
1426         pid = fork();
1427         if (pid == 0) {
1428                 /*
1429                  * Exec consumerd.
1430                  */
1431                 if (opt_verbose > 1 || opt_verbose_consumer) {
1432                         verbosity = "--verbose";
1433                 } else {
1434                         verbosity = "--quiet";
1435                 }
1436                 switch (consumer_data->type) {
1437                 case LTTNG_CONSUMER_KERNEL:
1438                         execl(INSTALL_BIN_PATH "/lttng-consumerd",
1439                                         "lttng-consumerd", verbosity, "-k", NULL);
1440                         break;
1441                 case LTTNG_CONSUMER_UST:
1442                         execl(INSTALL_BIN_PATH "/lttng-consumerd",
1443                                         "lttng-consumerd", verbosity, "-u", NULL);
1444                         break;
1445                 default:
1446                         perror("unknown consumer type");
1447                         exit(EXIT_FAILURE);
1448                 }
1449                 if (errno != 0) {
1450                         perror("kernel start consumer exec");
1451                 }
1452                 exit(EXIT_FAILURE);
1453         } else if (pid > 0) {
1454                 ret = pid;
1455         } else {
1456                 perror("start consumer fork");
1457                 ret = -errno;
1458         }
1459         return ret;
1460 }
1461
1462 /*
1463  * Spawn the consumerd daemon and session daemon thread.
1464  */
1465 static int start_consumerd(struct consumer_data *consumer_data)
1466 {
1467         int ret;
1468
1469         pthread_mutex_lock(&consumer_data->pid_mutex);
1470         if (consumer_data->pid != 0) {
1471                 pthread_mutex_unlock(&consumer_data->pid_mutex);
1472                 goto end;
1473         }
1474
1475         ret = spawn_consumerd(consumer_data);
1476         if (ret < 0) {
1477                 ERR("Spawning consumerd failed");
1478                 pthread_mutex_unlock(&consumer_data->pid_mutex);
1479                 goto error;
1480         }
1481
1482         /* Setting up the consumer_data pid */
1483         consumer_data->pid = ret;
1484         DBG2("Consumer pid %d", consumer_data->pid);
1485         pthread_mutex_unlock(&consumer_data->pid_mutex);
1486
1487         DBG2("Spawning consumer control thread");
1488         ret = spawn_consumer_thread(consumer_data);
1489         if (ret < 0) {
1490                 ERR("Fatal error spawning consumer control thread");
1491                 goto error;
1492         }
1493
1494 end:
1495         return 0;
1496
1497 error:
1498         return ret;
1499 }
1500
1501 /*
1502  * modprobe_kernel_modules
1503  */
1504 static int modprobe_kernel_modules(void)
1505 {
1506         int ret = 0, i;
1507         char modprobe[256];
1508
1509         for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
1510                 ret = snprintf(modprobe, sizeof(modprobe),
1511                         "/sbin/modprobe %s%s",
1512                         kernel_modules_list[i].required ? "" : "-q ",
1513                         kernel_modules_list[i].name);
1514                 if (ret < 0) {
1515                         perror("snprintf modprobe");
1516                         goto error;
1517                 }
1518                 modprobe[sizeof(modprobe) - 1] = '\0';
1519                 ret = system(modprobe);
1520                 if (ret == -1) {
1521                         ERR("Unable to launch modprobe for module %s",
1522                                 kernel_modules_list[i].name);
1523                 } else if (kernel_modules_list[i].required
1524                                 && WEXITSTATUS(ret) != 0) {
1525                         ERR("Unable to load module %s",
1526                                 kernel_modules_list[i].name);
1527                 } else {
1528                         DBG("Modprobe successfully %s",
1529                                 kernel_modules_list[i].name);
1530                 }
1531         }
1532
1533 error:
1534         return ret;
1535 }
1536
1537 /*
1538  * mount_debugfs
1539  */
1540 static int mount_debugfs(char *path)
1541 {
1542         int ret;
1543         char *type = "debugfs";
1544
1545         ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
1546         if (ret < 0) {
1547                 PERROR("Cannot create debugfs path");
1548                 goto error;
1549         }
1550
1551         ret = mount(type, path, type, 0, NULL);
1552         if (ret < 0) {
1553                 PERROR("Cannot mount debugfs");
1554                 goto error;
1555         }
1556
1557         DBG("Mounted debugfs successfully at %s", path);
1558
1559 error:
1560         return ret;
1561 }
1562
1563 /*
1564  * Setup necessary data for kernel tracer action.
1565  */
1566 static void init_kernel_tracer(void)
1567 {
1568         int ret;
1569         char *proc_mounts = "/proc/mounts";
1570         char line[256];
1571         char *debugfs_path = NULL, *lttng_path = NULL;
1572         FILE *fp;
1573
1574         /* Detect debugfs */
1575         fp = fopen(proc_mounts, "r");
1576         if (fp == NULL) {
1577                 ERR("Unable to probe %s", proc_mounts);
1578                 goto error;
1579         }
1580
1581         while (fgets(line, sizeof(line), fp) != NULL) {
1582                 if (strstr(line, "debugfs") != NULL) {
1583                         /* Remove first string */
1584                         strtok(line, " ");
1585                         /* Dup string here so we can reuse line later on */
1586                         debugfs_path = strdup(strtok(NULL, " "));
1587                         DBG("Got debugfs path : %s", debugfs_path);
1588                         break;
1589                 }
1590         }
1591
1592         fclose(fp);
1593
1594         /* Mount debugfs if needded */
1595         if (debugfs_path == NULL) {
1596                 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1597                 if (ret < 0) {
1598                         perror("asprintf debugfs path");
1599                         goto error;
1600                 }
1601                 ret = mount_debugfs(debugfs_path);
1602                 if (ret < 0) {
1603                         perror("Cannot mount debugfs");
1604                         goto error;
1605                 }
1606         }
1607
1608         /* Modprobe lttng kernel modules */
1609         ret = modprobe_kernel_modules();
1610         if (ret < 0) {
1611                 goto error;
1612         }
1613
1614         /* Setup lttng kernel path */
1615         ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1616         if (ret < 0) {
1617                 perror("asprintf lttng path");
1618                 goto error;
1619         }
1620
1621         /* Open debugfs lttng */
1622         kernel_tracer_fd = open(lttng_path, O_RDWR);
1623         if (kernel_tracer_fd < 0) {
1624                 DBG("Failed to open %s", lttng_path);
1625                 goto error;
1626         }
1627
1628         free(lttng_path);
1629         free(debugfs_path);
1630         DBG("Kernel tracer fd %d", kernel_tracer_fd);
1631         return;
1632
1633 error:
1634         if (lttng_path) {
1635                 free(lttng_path);
1636         }
1637         if (debugfs_path) {
1638                 free(debugfs_path);
1639         }
1640         WARN("No kernel tracer available");
1641         kernel_tracer_fd = 0;
1642         return;
1643 }
1644
1645 /*
1646  * Init tracing by creating trace directory and sending fds kernel consumer.
1647  */
1648 static int init_kernel_tracing(struct ltt_kernel_session *session)
1649 {
1650         int ret = 0;
1651
1652         if (session->consumer_fds_sent == 0) {
1653                 /*
1654                  * Assign default kernel consumer socket if no consumer assigned to the
1655                  * kernel session. At this point, it's NOT suppose to be 0 but this is
1656                  * an extra security check.
1657                  */
1658                 if (session->consumer_fd == 0) {
1659                         session->consumer_fd = kconsumer_data.cmd_sock;
1660                 }
1661
1662                 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1663                 if (ret < 0) {
1664                         ret = LTTCOMM_KERN_CONSUMER_FAIL;
1665                         goto error;
1666                 }
1667
1668                 session->consumer_fds_sent = 1;
1669         }
1670
1671 error:
1672         return ret;
1673 }
1674
1675 /*
1676  * Create an UST session and add it to the session ust list.
1677  */
1678 static int create_ust_session(struct ltt_session *session,
1679                 struct lttng_domain *domain)
1680 {
1681         int ret;
1682         unsigned int uid;
1683         struct ltt_ust_session *lus = NULL;
1684
1685         switch (domain->type) {
1686         case LTTNG_DOMAIN_UST:
1687                 break;
1688         default:
1689                 ret = LTTCOMM_UNKNOWN_DOMAIN;
1690                 goto error;
1691         }
1692
1693         DBG("Creating UST session");
1694
1695         session_lock_list();
1696         uid = session_list_ptr->count;
1697         session_unlock_list();
1698
1699         lus = trace_ust_create_session(session->path, uid, domain);
1700         if (lus == NULL) {
1701                 ret = LTTCOMM_UST_SESS_FAIL;
1702                 goto error;
1703         }
1704
1705         ret = mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
1706                         geteuid(), allowed_group());
1707         if (ret < 0) {
1708                 if (ret != -EEXIST) {
1709                         ERR("Trace directory creation error");
1710                         ret = LTTCOMM_UST_SESS_FAIL;
1711                         goto error;
1712                 }
1713         }
1714
1715         /* The domain type dictate different actions on session creation */
1716         switch (domain->type) {
1717         case LTTNG_DOMAIN_UST:
1718                 /* No ustctl for the global UST domain */
1719                 break;
1720         default:
1721                 ERR("Unknown UST domain on create session %d", domain->type);
1722                 goto error;
1723         }
1724         session->ust_session = lus;
1725
1726         return LTTCOMM_OK;
1727
1728 error:
1729         free(lus);
1730         return ret;
1731 }
1732
1733 /*
1734  * Create a kernel tracer session then create the default channel.
1735  */
1736 static int create_kernel_session(struct ltt_session *session)
1737 {
1738         int ret;
1739
1740         DBG("Creating kernel session");
1741
1742         ret = kernel_create_session(session, kernel_tracer_fd);
1743         if (ret < 0) {
1744                 ret = LTTCOMM_KERN_SESS_FAIL;
1745                 goto error;
1746         }
1747
1748         /* Set kernel consumer socket fd */
1749         if (kconsumer_data.cmd_sock) {
1750                 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
1751         }
1752
1753         ret = mkdir_recursive(session->kernel_session->trace_path,
1754                         S_IRWXU | S_IRWXG, geteuid(), allowed_group());
1755         if (ret < 0) {
1756                 if (ret != -EEXIST) {
1757                         ERR("Trace directory creation error");
1758                         goto error;
1759                 }
1760         }
1761
1762 error:
1763         return ret;
1764 }
1765
1766 /*
1767  * Using the session list, filled a lttng_session array to send back to the
1768  * client for session listing.
1769  *
1770  * The session list lock MUST be acquired before calling this function. Use
1771  * session_lock_list() and session_unlock_list().
1772  */
1773 static void list_lttng_sessions(struct lttng_session *sessions)
1774 {
1775         int i = 0;
1776         struct ltt_session *session;
1777
1778         DBG("Getting all available session");
1779         /*
1780          * Iterate over session list and append data after the control struct in
1781          * the buffer.
1782          */
1783         cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1784                 strncpy(sessions[i].path, session->path, PATH_MAX);
1785                 sessions[i].path[PATH_MAX - 1] = '\0';
1786                 strncpy(sessions[i].name, session->name, NAME_MAX);
1787                 sessions[i].name[NAME_MAX - 1] = '\0';
1788                 i++;
1789         }
1790 }
1791
1792 /*
1793  * Fill lttng_channel array of all channels.
1794  */
1795 static void list_lttng_channels(struct ltt_session *session,
1796                 struct lttng_channel *channels)
1797 {
1798         int i = 0;
1799         struct ltt_kernel_channel *kchan;
1800
1801         DBG("Listing channels for session %s", session->name);
1802
1803         /* Kernel channels */
1804         if (session->kernel_session != NULL) {
1805                 cds_list_for_each_entry(kchan,
1806                                 &session->kernel_session->channel_list.head, list) {
1807                         /* Copy lttng_channel struct to array */
1808                         memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1809                         channels[i].enabled = kchan->enabled;
1810                         i++;
1811                 }
1812         }
1813
1814         /* TODO: Missing UST listing */
1815 }
1816
1817 /*
1818  * Fill lttng_event array of all events in the channel.
1819  */
1820 static void list_lttng_events(struct ltt_kernel_channel *kchan,
1821                 struct lttng_event *events)
1822 {
1823         /*
1824          * TODO: This is ONLY kernel. Need UST support.
1825          */
1826         int i = 0;
1827         struct ltt_kernel_event *event;
1828
1829         DBG("Listing events for channel %s", kchan->channel->name);
1830
1831         /* Kernel channels */
1832         cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1833                 strncpy(events[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1834                 events[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1835                 events[i].enabled = event->enabled;
1836                 switch (event->event->instrumentation) {
1837                         case LTTNG_KERNEL_TRACEPOINT:
1838                                 events[i].type = LTTNG_EVENT_TRACEPOINT;
1839                                 break;
1840                         case LTTNG_KERNEL_KPROBE:
1841                         case LTTNG_KERNEL_KRETPROBE:
1842                                 events[i].type = LTTNG_EVENT_PROBE;
1843                                 memcpy(&events[i].attr.probe, &event->event->u.kprobe,
1844                                                 sizeof(struct lttng_kernel_kprobe));
1845                                 break;
1846                         case LTTNG_KERNEL_FUNCTION:
1847                                 events[i].type = LTTNG_EVENT_FUNCTION;
1848                                 memcpy(&events[i].attr.ftrace, &event->event->u.ftrace,
1849                                                 sizeof(struct lttng_kernel_function));
1850                                 break;
1851                         case LTTNG_KERNEL_NOOP:
1852                                 events[i].type = LTTNG_EVENT_NOOP;
1853                                 break;
1854                         case LTTNG_KERNEL_SYSCALL:
1855                                 events[i].type = LTTNG_EVENT_SYSCALL;
1856                                 break;
1857                         case LTTNG_KERNEL_ALL:
1858                                 assert(0);
1859                                 break;
1860                 }
1861                 i++;
1862         }
1863 }
1864
1865 /*
1866  * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1867  */
1868 static int cmd_disable_channel(struct ltt_session *session,
1869                 int domain, char *channel_name)
1870 {
1871         int ret;
1872
1873         switch (domain) {
1874                 case LTTNG_DOMAIN_KERNEL:
1875                         ret = channel_kernel_disable(session->kernel_session,
1876                                         channel_name);
1877                         if (ret != LTTCOMM_OK) {
1878                                 goto error;
1879                         }
1880
1881                         kernel_wait_quiescent(kernel_tracer_fd);
1882                         break;
1883                 case LTTNG_DOMAIN_UST_PID:
1884                         break;
1885                 default:
1886                         ret = LTTCOMM_UNKNOWN_DOMAIN;
1887                         goto error;
1888         }
1889
1890         ret = LTTCOMM_OK;
1891
1892 error:
1893         return ret;
1894 }
1895
1896 /*
1897  * Copy channel from attributes and set it in the application channel list.
1898  */
1899 /*
1900 static int copy_ust_channel_to_app(struct ltt_ust_session *usess,
1901                 struct lttng_channel *attr, struct ust_app *app)
1902 {
1903         int ret;
1904         struct ltt_ust_channel *uchan, *new_chan;
1905
1906         uchan = trace_ust_get_channel_by_key(usess->channels, attr->name);
1907         if (uchan == NULL) {
1908                 ret = LTTCOMM_FATAL;
1909                 goto error;
1910         }
1911
1912         new_chan = trace_ust_create_channel(attr, usess->path);
1913         if (new_chan == NULL) {
1914                 PERROR("malloc ltt_ust_channel");
1915                 ret = LTTCOMM_FATAL;
1916                 goto error;
1917         }
1918
1919         ret = channel_ust_copy(new_chan, uchan);
1920         if (ret < 0) {
1921                 ret = LTTCOMM_FATAL;
1922                 goto error;
1923         }
1924
1925 error:
1926         return ret;
1927 }
1928 */
1929
1930 /*
1931  * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1932  */
1933 static int cmd_enable_channel(struct ltt_session *session,
1934                 struct lttng_domain *domain, struct lttng_channel *attr)
1935 {
1936         int ret;
1937         struct ltt_ust_session *usess = session->ust_session;
1938
1939         DBG("Enabling channel %s for session %s", session->name, attr->name);
1940
1941         switch (domain->type) {
1942         case LTTNG_DOMAIN_KERNEL:
1943         {
1944                 struct ltt_kernel_channel *kchan;
1945
1946                 kchan = trace_kernel_get_channel_by_name(attr->name,
1947                                 session->kernel_session);
1948                 if (kchan == NULL) {
1949                         ret = channel_kernel_create(session->kernel_session,
1950                                         attr, kernel_poll_pipe[1]);
1951                 } else {
1952                         ret = channel_kernel_enable(session->kernel_session, kchan);
1953                 }
1954
1955                 if (ret != LTTCOMM_OK) {
1956                         goto error;
1957                 }
1958
1959                 kernel_wait_quiescent(kernel_tracer_fd);
1960                 break;
1961         }
1962         case LTTNG_DOMAIN_UST:
1963         {
1964                 struct ltt_ust_channel *uchan;
1965
1966                 DBG2("Enabling channel for LTTNG_DOMAIN_UST");
1967
1968                 /* Get channel in global UST domain HT */
1969                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1970                                 attr->name);
1971                 if (uchan == NULL) {
1972                         uchan = trace_ust_create_channel(attr, usess->pathname);
1973                         if (uchan == NULL) {
1974                                 ret = LTTCOMM_UST_CHAN_FAIL;
1975                                 goto error;
1976                         }
1977                         rcu_read_lock();
1978                         hashtable_add_unique(usess->domain_global.channels, &uchan->node);
1979                         rcu_read_unlock();
1980                         DBG2("UST channel %s added to global domain HT", attr->name);
1981                 } else {
1982                         ret = LTTCOMM_UST_CHAN_EXIST;
1983                         goto error;
1984                 }
1985
1986                 ret = ust_app_add_channel(usess, uchan);
1987                 if (ret != LTTCOMM_OK) {
1988                         goto error;
1989                 }
1990
1991                 break;
1992         }
1993         case LTTNG_DOMAIN_UST_PID:
1994         {
1995                 /*
1996                 int sock;
1997                 struct ltt_ust_channel *uchan;
1998                 struct ltt_ust_session *usess;
1999                 struct ust_app *app;
2000
2001                 usess = trace_ust_get_session_by_pid(&session->ust_session_list,
2002                                 domain->attr.pid);
2003                 if (usess == NULL) {
2004                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2005                         goto error;
2006                 }
2007
2008                 app = ust_app_get_by_pid(domain->attr.pid);
2009                 if (app == NULL) {
2010                         ret = LTTCOMM_APP_NOT_FOUND;
2011                         goto error;
2012                 }
2013                 sock = app->sock;
2014
2015                 uchan = trace_ust_get_channel_by_name(attr->name, usess);
2016                 if (uchan == NULL) {
2017                         ret = channel_ust_create(usess, attr, sock);
2018                 } else {
2019                         ret = channel_ust_enable(usess, uchan, sock);
2020                 }
2021
2022                 if (ret != LTTCOMM_OK) {
2023                         goto error;
2024                 }
2025
2026                 ret = copy_ust_channel_to_app(usess, attr, app);
2027                 if (ret != LTTCOMM_OK) {
2028                         goto error;
2029                 }
2030
2031                 DBG("UST channel %s created for app sock %d with pid %d",
2032                                 attr->name, app->sock, domain->attr.pid);
2033                 */
2034                 ret = LTTCOMM_NOT_IMPLEMENTED;
2035                 goto error;
2036         }
2037         default:
2038                 ret = LTTCOMM_UNKNOWN_DOMAIN;
2039                 goto error;
2040         }
2041
2042         ret = LTTCOMM_OK;
2043
2044 error:
2045         return ret;
2046 }
2047
2048 /*
2049  * Command LTTNG_DISABLE_EVENT processed by the client thread.
2050  */
2051 static int cmd_disable_event(struct ltt_session *session, int domain,
2052                 char *channel_name, char *event_name)
2053 {
2054         int ret;
2055
2056         switch (domain) {
2057         case LTTNG_DOMAIN_KERNEL:
2058         {
2059                 struct ltt_kernel_channel *kchan;
2060
2061                 kchan = trace_kernel_get_channel_by_name(channel_name,
2062                                 session->kernel_session);
2063                 if (kchan == NULL) {
2064                         ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2065                         goto error;
2066                 }
2067
2068                 ret = event_kernel_disable_tracepoint(session->kernel_session, kchan, event_name);
2069                 if (ret != LTTCOMM_OK) {
2070                         goto error;
2071                 }
2072
2073                 kernel_wait_quiescent(kernel_tracer_fd);
2074                 break;
2075         }
2076         case LTTNG_DOMAIN_UST:
2077         case LTTNG_DOMAIN_UST_EXEC_NAME:
2078         case LTTNG_DOMAIN_UST_PID:
2079         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2080         default:
2081                 /* TODO: Other UST domains */
2082                 ret = LTTCOMM_NOT_IMPLEMENTED;
2083                 goto error;
2084         }
2085
2086         ret = LTTCOMM_OK;
2087
2088 error:
2089         return ret;
2090 }
2091
2092 /*
2093  * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2094  */
2095 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2096                 char *channel_name)
2097 {
2098         int ret;
2099         struct ltt_kernel_channel *kchan;
2100
2101         switch (domain) {
2102         case LTTNG_DOMAIN_KERNEL:
2103                 kchan = trace_kernel_get_channel_by_name(channel_name,
2104                                 session->kernel_session);
2105                 if (kchan == NULL) {
2106                         ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2107                         goto error;
2108                 }
2109
2110                 ret = event_kernel_disable_all(session->kernel_session, kchan);
2111                 if (ret != LTTCOMM_OK) {
2112                         goto error;
2113                 }
2114
2115                 kernel_wait_quiescent(kernel_tracer_fd);
2116                 break;
2117         default:
2118                 /* TODO: Userspace tracing */
2119                 ret = LTTCOMM_NOT_IMPLEMENTED;
2120                 goto error;
2121         }
2122
2123         ret = LTTCOMM_OK;
2124
2125 error:
2126         return ret;
2127 }
2128
2129 /*
2130  * Command LTTNG_ADD_CONTEXT processed by the client thread.
2131  */
2132 static int cmd_add_context(struct ltt_session *session, int domain,
2133                 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2134 {
2135         int ret;
2136
2137         switch (domain) {
2138         case LTTNG_DOMAIN_KERNEL:
2139                 /* Add kernel context to kernel tracer */
2140                 ret = context_kernel_add(session->kernel_session, ctx,
2141                                 event_name, channel_name);
2142                 if (ret != LTTCOMM_OK) {
2143                         goto error;
2144                 }
2145                 break;
2146         case LTTNG_DOMAIN_UST:
2147         {
2148                 /*
2149                 struct ltt_ust_session *usess;
2150
2151                 cds_list_for_each_entry(usess, &session->ust_session_list.head, list) {
2152                         ret = context_ust_add(usess, ctx,
2153                                         event_name, channel_name, domain);
2154                         if (ret != LTTCOMM_OK) {
2155                                 goto error;
2156                         }
2157                 }
2158                 break;
2159                 */
2160         }
2161         default:
2162                 /* TODO: UST other domains */
2163                 ret = LTTCOMM_NOT_IMPLEMENTED;
2164                 goto error;
2165         }
2166
2167         ret = LTTCOMM_OK;
2168
2169 error:
2170         return ret;
2171 }
2172
2173 /*
2174  * Command LTTNG_ENABLE_EVENT processed by the client thread.
2175  */
2176 static int cmd_enable_event(struct ltt_session *session, int domain,
2177                 char *channel_name, struct lttng_event *event)
2178 {
2179         int ret;
2180         struct lttng_channel *attr;
2181         struct ltt_ust_session *usess = session->ust_session;
2182
2183         switch (domain) {
2184         case LTTNG_DOMAIN_KERNEL:
2185         {
2186                 struct ltt_kernel_channel *kchan;
2187
2188                 kchan = trace_kernel_get_channel_by_name(channel_name,
2189                                 session->kernel_session);
2190                 if (kchan == NULL) {
2191                         attr = channel_new_default_attr(domain);
2192                         if (attr == NULL) {
2193                                 ret = LTTCOMM_FATAL;
2194                                 goto error;
2195                         }
2196                         snprintf(attr->name, NAME_MAX, "%s", channel_name);
2197
2198                         /* This call will notify the kernel thread */
2199                         ret = channel_kernel_create(session->kernel_session,
2200                                         attr, kernel_poll_pipe[1]);
2201                         if (ret != LTTCOMM_OK) {
2202                                 goto error;
2203                         }
2204                 }
2205
2206                 /* Get the newly created kernel channel pointer */
2207                 kchan = trace_kernel_get_channel_by_name(channel_name,
2208                                 session->kernel_session);
2209                 if (kchan == NULL) {
2210                         /* This sould not happen... */
2211                         ret = LTTCOMM_FATAL;
2212                         goto error;
2213                 }
2214
2215                 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2216                                 event);
2217                 if (ret != LTTCOMM_OK) {
2218                         goto error;
2219                 }
2220
2221                 kernel_wait_quiescent(kernel_tracer_fd);
2222                 break;
2223         }
2224         case LTTNG_DOMAIN_UST:
2225         {
2226                 struct ltt_ust_channel *uchan;
2227                 struct ltt_ust_event *uevent;
2228
2229                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2230                                 channel_name);
2231                 if (uchan == NULL) {
2232                         /* TODO: Create default channel */
2233                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2234                         goto error;
2235                 }
2236
2237                 uevent = trace_ust_find_event_by_name(uchan->events, event->name);
2238                 if (uevent == NULL) {
2239                         uevent = trace_ust_create_event(event);
2240                         if (uevent == NULL) {
2241                                 ret = LTTCOMM_FATAL;
2242                                 goto error;
2243                         }
2244                 }
2245
2246                 ret = ust_app_add_event(usess, uchan, uevent);
2247                 if (ret < 0) {
2248                         ret = LTTCOMM_UST_ENABLE_FAIL;
2249                         goto error;
2250                 }
2251
2252                 rcu_read_lock();
2253                 hashtable_add_unique(uchan->events, &uevent->node);
2254                 rcu_read_unlock();
2255                 break;
2256         }
2257         case LTTNG_DOMAIN_UST_EXEC_NAME:
2258         case LTTNG_DOMAIN_UST_PID:
2259         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2260         default:
2261                 ret = LTTCOMM_NOT_IMPLEMENTED;
2262                 goto error;
2263         }
2264
2265         ret = LTTCOMM_OK;
2266
2267 error:
2268         return ret;
2269 }
2270
2271 /*
2272  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2273  */
2274 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2275                 char *channel_name, int event_type)
2276 {
2277         int ret;
2278         struct ltt_kernel_channel *kchan;
2279
2280         switch (domain) {
2281         case LTTNG_DOMAIN_KERNEL:
2282                 kchan = trace_kernel_get_channel_by_name(channel_name,
2283                                 session->kernel_session);
2284                 if (kchan == NULL) {
2285                         /* This call will notify the kernel thread */
2286                         ret = channel_kernel_create(session->kernel_session, NULL,
2287                                         kernel_poll_pipe[1]);
2288                         if (ret != LTTCOMM_OK) {
2289                                 goto error;
2290                         }
2291                 }
2292
2293                 /* Get the newly created kernel channel pointer */
2294                 kchan = trace_kernel_get_channel_by_name(channel_name,
2295                                 session->kernel_session);
2296                 if (kchan == NULL) {
2297                         /* This sould not happen... */
2298                         ret = LTTCOMM_FATAL;
2299                         goto error;
2300                 }
2301
2302                 switch (event_type) {
2303                 case LTTNG_KERNEL_SYSCALL:
2304                         ret = event_kernel_enable_all_syscalls(session->kernel_session,
2305                                         kchan, kernel_tracer_fd);
2306                         break;
2307                 case LTTNG_KERNEL_TRACEPOINT:
2308                         /*
2309                          * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2310                          * events already registered to the channel.
2311                          */
2312                         ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2313                                         kchan, kernel_tracer_fd);
2314                         break;
2315                 case LTTNG_KERNEL_ALL:
2316                         /* Enable syscalls and tracepoints */
2317                         ret = event_kernel_enable_all(session->kernel_session,
2318                                         kchan, kernel_tracer_fd);
2319                         break;
2320                 default:
2321                         ret = LTTCOMM_KERN_ENABLE_FAIL;
2322                         goto error;
2323                 }
2324                 if (ret != LTTCOMM_OK) {
2325                         goto error;
2326                 }
2327
2328                 kernel_wait_quiescent(kernel_tracer_fd);
2329                 break;
2330         default:
2331                 /* TODO: Userspace tracing */
2332                 ret = LTTCOMM_NOT_IMPLEMENTED;
2333                 goto error;
2334         }
2335
2336         ret = LTTCOMM_OK;
2337
2338 error:
2339         return ret;
2340 }
2341
2342 /*
2343  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2344  */
2345 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2346 {
2347         int ret;
2348         ssize_t nb_events = 0;
2349
2350         switch (domain) {
2351         case LTTNG_DOMAIN_KERNEL:
2352                 nb_events = kernel_list_events(kernel_tracer_fd, events);
2353                 if (nb_events < 0) {
2354                         ret = LTTCOMM_KERN_LIST_FAIL;
2355                         goto error;
2356                 }
2357                 break;
2358         default:
2359                 /* TODO: Userspace listing */
2360                 ret = LTTCOMM_NOT_IMPLEMENTED;
2361                 goto error;
2362         }
2363
2364         return nb_events;
2365
2366 error:
2367         /* Return negative value to differentiate return code */
2368         return -ret;
2369 }
2370
2371 /*
2372  * Command LTTNG_START_TRACE processed by the client thread.
2373  */
2374 static int cmd_start_trace(struct ltt_session *session)
2375 {
2376         int ret;
2377         struct ltt_kernel_session *ksession;
2378         struct ltt_ust_session *usess = session->ust_session;
2379
2380         /* Short cut */
2381         ksession = session->kernel_session;
2382
2383         /* Kernel tracing */
2384         if (ksession != NULL) {
2385                 struct ltt_kernel_channel *kchan;
2386
2387                 /* Open kernel metadata */
2388                 if (ksession->metadata == NULL) {
2389                         ret = kernel_open_metadata(ksession, ksession->trace_path);
2390                         if (ret < 0) {
2391                                 ret = LTTCOMM_KERN_META_FAIL;
2392                                 goto error;
2393                         }
2394                 }
2395
2396                 /* Open kernel metadata stream */
2397                 if (ksession->metadata_stream_fd == 0) {
2398                         ret = kernel_open_metadata_stream(ksession);
2399                         if (ret < 0) {
2400                                 ERR("Kernel create metadata stream failed");
2401                                 ret = LTTCOMM_KERN_STREAM_FAIL;
2402                                 goto error;
2403                         }
2404                 }
2405
2406                 /* For each channel */
2407                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2408                         if (kchan->stream_count == 0) {
2409                                 ret = kernel_open_channel_stream(kchan);
2410                                 if (ret < 0) {
2411                                         ret = LTTCOMM_KERN_STREAM_FAIL;
2412                                         goto error;
2413                                 }
2414                                 /* Update the stream global counter */
2415                                 ksession->stream_count_global += ret;
2416                         }
2417                 }
2418
2419                 /* Setup kernel consumer socket and send fds to it */
2420                 ret = init_kernel_tracing(ksession);
2421                 if (ret < 0) {
2422                         ret = LTTCOMM_KERN_START_FAIL;
2423                         goto error;
2424                 }
2425
2426                 /* This start the kernel tracing */
2427                 ret = kernel_start_session(ksession);
2428                 if (ret < 0) {
2429                         ret = LTTCOMM_KERN_START_FAIL;
2430                         goto error;
2431                 }
2432
2433                 /* Quiescent wait after starting trace */
2434                 kernel_wait_quiescent(kernel_tracer_fd);
2435         }
2436
2437         /* Flag session that trace should start automatically */
2438         usess->start_trace = 1;
2439
2440         ret = ust_app_start_trace(usess);
2441         if (ret < 0) {
2442                 ret = LTTCOMM_UST_START_FAIL;
2443                 goto error;
2444         }
2445
2446         ret = LTTCOMM_OK;
2447
2448 error:
2449         return ret;
2450 }
2451
2452 /*
2453  * Command LTTNG_STOP_TRACE processed by the client thread.
2454  */
2455 static int cmd_stop_trace(struct ltt_session *session)
2456 {
2457         int ret;
2458         struct ltt_kernel_channel *kchan;
2459         struct ltt_kernel_session *ksession;
2460         //struct ltt_ust_session *usess;
2461         //struct ltt_ust_channel *ustchan;
2462
2463         /* Short cut */
2464         ksession = session->kernel_session;
2465
2466         /* Kernel tracer */
2467         if (ksession != NULL) {
2468                 DBG("Stop kernel tracing");
2469
2470                 /* Flush all buffers before stopping */
2471                 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2472                 if (ret < 0) {
2473                         ERR("Kernel metadata flush failed");
2474                 }
2475
2476                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2477                         ret = kernel_flush_buffer(kchan);
2478                         if (ret < 0) {
2479                                 ERR("Kernel flush buffer error");
2480                         }
2481                 }
2482
2483                 ret = kernel_stop_session(ksession);
2484                 if (ret < 0) {
2485                         ret = LTTCOMM_KERN_STOP_FAIL;
2486                         goto error;
2487                 }
2488
2489                 kernel_wait_quiescent(kernel_tracer_fd);
2490         }
2491
2492 #ifdef DISABLE
2493         /* Stop each UST session */
2494         DBG("Stop UST tracing");
2495         cds_list_for_each_entry(usess, &session->ust_session_list.head, list) {
2496                 /* Flush all buffers before stopping */
2497                 ret = ustctl_flush_buffer(usess->sock, usess->metadata->obj);
2498                 if (ret < 0) {
2499                         ERR("UST metadata flush failed");
2500                 }
2501
2502                 cds_list_for_each_entry(ustchan, &usess->channels.head, list) {
2503                         ret = ustctl_flush_buffer(usess->sock, ustchan->obj);
2504                         if (ret < 0) {
2505                                 ERR("UST flush buffer error");
2506                         }
2507                 }
2508
2509                 ret = ustctl_stop_session(usess->sock, usess->handle);
2510                 if (ret < 0) {
2511                         ret = LTTCOMM_KERN_STOP_FAIL;
2512                         goto error;
2513                 }
2514
2515                 ustctl_wait_quiescent(usess->sock);
2516         }
2517 #endif
2518
2519         ret = LTTCOMM_OK;
2520
2521 error:
2522         return ret;
2523 }
2524
2525 /*
2526  * Command LTTNG_CREATE_SESSION processed by the client thread.
2527  */
2528 static int cmd_create_session(char *name, char *path)
2529 {
2530         int ret;
2531
2532         ret = session_create(name, path);
2533         if (ret != LTTCOMM_OK) {
2534                 goto error;
2535         }
2536
2537         ret = LTTCOMM_OK;
2538
2539 error:
2540         return ret;
2541 }
2542
2543 /*
2544  * Command LTTNG_DESTROY_SESSION processed by the client thread.
2545  */
2546 static int cmd_destroy_session(struct ltt_session *session, char *name)
2547 {
2548         int ret;
2549
2550         /* Clean kernel session teardown */
2551         teardown_kernel_session(session);
2552
2553         /*
2554          * Must notify the kernel thread here to update it's poll setin order
2555          * to remove the channel(s)' fd just destroyed.
2556          */
2557         ret = notify_thread_pipe(kernel_poll_pipe[1]);
2558         if (ret < 0) {
2559                 perror("write kernel poll pipe");
2560         }
2561
2562         ret = session_destroy(session);
2563
2564         return ret;
2565 }
2566
2567 /*
2568  * Command LTTNG_CALIBRATE processed by the client thread.
2569  */
2570 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
2571 {
2572         int ret;
2573
2574         switch (domain) {
2575         case LTTNG_DOMAIN_KERNEL:
2576         {
2577                 struct lttng_kernel_calibrate kcalibrate;
2578
2579                 kcalibrate.type = calibrate->type;
2580                 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2581                 if (ret < 0) {
2582                         ret = LTTCOMM_KERN_ENABLE_FAIL;
2583                         goto error;
2584                 }
2585                 break;
2586         }
2587         default:
2588                 /* TODO: Userspace tracing */
2589                 ret = LTTCOMM_NOT_IMPLEMENTED;
2590                 goto error;
2591         }
2592
2593         ret = LTTCOMM_OK;
2594
2595 error:
2596         return ret;
2597 }
2598
2599 /*
2600  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
2601  */
2602 static int cmd_register_consumer(struct ltt_session *session, int domain,
2603                 char *sock_path)
2604 {
2605         int ret, sock;
2606
2607         switch (domain) {
2608         case LTTNG_DOMAIN_KERNEL:
2609                 /* Can't register a consumer if there is already one */
2610                 if (session->kernel_session->consumer_fd != 0) {
2611                         ret = LTTCOMM_KERN_CONSUMER_FAIL;
2612                         goto error;
2613                 }
2614
2615                 sock = lttcomm_connect_unix_sock(sock_path);
2616                 if (sock < 0) {
2617                         ret = LTTCOMM_CONNECT_FAIL;
2618                         goto error;
2619                 }
2620
2621                 session->kernel_session->consumer_fd = sock;
2622                 break;
2623         default:
2624                 /* TODO: Userspace tracing */
2625                 ret = LTTCOMM_NOT_IMPLEMENTED;
2626                 goto error;
2627         }
2628
2629         ret = LTTCOMM_OK;
2630
2631 error:
2632         return ret;
2633 }
2634
2635 /*
2636  * Command LTTNG_LIST_DOMAINS processed by the client thread.
2637  */
2638 static ssize_t cmd_list_domains(struct ltt_session *session,
2639                 struct lttng_domain **domains)
2640 {
2641         int ret;
2642         ssize_t nb_dom = 0;
2643
2644         if (session->kernel_session != NULL) {
2645                 nb_dom++;
2646         }
2647
2648         /* TODO: User-space tracer domain support */
2649
2650         *domains = malloc(nb_dom * sizeof(struct lttng_domain));
2651         if (*domains == NULL) {
2652                 ret = -LTTCOMM_FATAL;
2653                 goto error;
2654         }
2655
2656         (*domains)[0].type = LTTNG_DOMAIN_KERNEL;
2657
2658         return nb_dom;
2659
2660 error:
2661         return ret;
2662 }
2663
2664 /*
2665  * Command LTTNG_LIST_CHANNELS processed by the client thread.
2666  */
2667 static ssize_t cmd_list_channels(struct ltt_session *session,
2668                 struct lttng_channel **channels)
2669 {
2670         int ret;
2671         ssize_t nb_chan = 0;
2672
2673         if (session->kernel_session != NULL) {
2674                 nb_chan += session->kernel_session->channel_count;
2675         }
2676
2677         *channels = malloc(nb_chan * sizeof(struct lttng_channel));
2678         if (*channels == NULL) {
2679                 ret = -LTTCOMM_FATAL;
2680                 goto error;
2681         }
2682
2683         list_lttng_channels(session, *channels);
2684
2685         /* TODO UST support */
2686
2687         return nb_chan;
2688
2689 error:
2690         return ret;
2691 }
2692
2693 /*
2694  * Command LTTNG_LIST_EVENTS processed by the client thread.
2695  */
2696 static ssize_t cmd_list_events(struct ltt_session *session,
2697                 char *channel_name, struct lttng_event **events)
2698 {
2699         int ret;
2700         ssize_t nb_event = 0;
2701         struct ltt_kernel_channel *kchan = NULL;
2702
2703         if (session->kernel_session != NULL) {
2704                 kchan = trace_kernel_get_channel_by_name(channel_name,
2705                                 session->kernel_session);
2706                 if (kchan == NULL) {
2707                         ret = -LTTCOMM_KERN_CHAN_NOT_FOUND;
2708                         goto error;
2709                 }
2710                 nb_event += kchan->event_count;
2711         }
2712
2713         *events = malloc(nb_event * sizeof(struct lttng_event));
2714         if (*events == NULL) {
2715                 ret = -LTTCOMM_FATAL;
2716                 goto error;
2717         }
2718
2719         list_lttng_events(kchan, *events);
2720
2721         /* TODO: User-space tracer support */
2722
2723         return nb_event;
2724
2725 error:
2726         return ret;
2727 }
2728
2729 /*
2730  * Process the command requested by the lttng client within the command
2731  * context structure. This function make sure that the return structure (llm)
2732  * is set and ready for transmission before returning.
2733  *
2734  * Return any error encountered or 0 for success.
2735  */
2736 static int process_client_msg(struct command_ctx *cmd_ctx)
2737 {
2738         int ret = LTTCOMM_OK;
2739         int need_tracing_session = 1;
2740
2741         DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
2742
2743         /*
2744          * Check for command that don't needs to allocate a returned payload. We do
2745          * this here so we don't have to make the call for no payload at each
2746          * command.
2747          */
2748         switch(cmd_ctx->lsm->cmd_type) {
2749         case LTTNG_LIST_SESSIONS:
2750         case LTTNG_LIST_TRACEPOINTS:
2751         case LTTNG_LIST_DOMAINS:
2752         case LTTNG_LIST_CHANNELS:
2753         case LTTNG_LIST_EVENTS:
2754                 break;
2755         default:
2756                 /* Setup lttng message with no payload */
2757                 ret = setup_lttng_msg(cmd_ctx, 0);
2758                 if (ret < 0) {
2759                         /* This label does not try to unlock the session */
2760                         goto init_setup_error;
2761                 }
2762         }
2763
2764         /* Commands that DO NOT need a session. */
2765         switch (cmd_ctx->lsm->cmd_type) {
2766         case LTTNG_CALIBRATE:
2767         case LTTNG_CREATE_SESSION:
2768         case LTTNG_LIST_SESSIONS:
2769         case LTTNG_LIST_TRACEPOINTS:
2770                 need_tracing_session = 0;
2771                 break;
2772         default:
2773                 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
2774                 session_lock_list();
2775                 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
2776                 session_unlock_list();
2777                 if (cmd_ctx->session == NULL) {
2778                         if (cmd_ctx->lsm->session.name != NULL) {
2779                                 ret = LTTCOMM_SESS_NOT_FOUND;
2780                         } else {
2781                                 /* If no session name specified */
2782                                 ret = LTTCOMM_SELECT_SESS;
2783                         }
2784                         goto error;
2785                 } else {
2786                         /* Acquire lock for the session */
2787                         session_lock(cmd_ctx->session);
2788                 }
2789                 break;
2790         }
2791
2792         /*
2793          * Check domain type for specific "pre-action".
2794          */
2795         switch (cmd_ctx->lsm->domain.type) {
2796         case LTTNG_DOMAIN_KERNEL:
2797                 /* Kernel tracer check */
2798                 if (kernel_tracer_fd == 0) {
2799                         /* Basically, load kernel tracer modules */
2800                         init_kernel_tracer();
2801                         if (kernel_tracer_fd == 0) {
2802                                 ret = LTTCOMM_KERN_NA;
2803                                 goto error;
2804                         }
2805                 }
2806
2807                 /* Need a session for kernel command */
2808                 if (need_tracing_session) {
2809                         if (cmd_ctx->session->kernel_session == NULL) {
2810                                 ret = create_kernel_session(cmd_ctx->session);
2811                                 if (ret < 0) {
2812                                         ret = LTTCOMM_KERN_SESS_FAIL;
2813                                         goto error;
2814                                 }
2815                         }
2816
2817                         /* Start the kernel consumer daemon */
2818                         pthread_mutex_lock(&kconsumer_data.pid_mutex);
2819                         if (kconsumer_data.pid == 0 &&
2820                                         cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
2821                                 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
2822                                 ret = start_consumerd(&kconsumer_data);
2823                                 if (ret < 0) {
2824                                         ret = LTTCOMM_KERN_CONSUMER_FAIL;
2825                                         goto error;
2826                                 }
2827                         }
2828                         pthread_mutex_unlock(&kconsumer_data.pid_mutex);
2829                 }
2830                 break;
2831         case LTTNG_DOMAIN_UST:
2832         {
2833                 if (need_tracing_session) {
2834                         if (cmd_ctx->session->ust_session == NULL) {
2835                                 ret = create_ust_session(cmd_ctx->session,
2836                                                 &cmd_ctx->lsm->domain);
2837                                 if (ret != LTTCOMM_OK) {
2838                                         goto error;
2839                                 }
2840                         }
2841                         /* Start the kernel consumer daemon */
2842                         pthread_mutex_lock(&ustconsumer_data.pid_mutex);
2843                         if (ustconsumer_data.pid == 0 &&
2844                                         cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
2845                                 pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
2846                                 ret = start_consumerd(&ustconsumer_data);
2847                                 if (ret < 0) {
2848                                         ret = LTTCOMM_KERN_CONSUMER_FAIL;
2849                                         goto error;
2850                                 }
2851
2852                                 cmd_ctx->session->ust_session->consumer_fd =
2853                                         ustconsumer_data.cmd_sock;
2854                         }
2855                         pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
2856                 }
2857                 break;
2858         }
2859         default:
2860                 break;
2861         }
2862
2863         /* Process by command type */
2864         switch (cmd_ctx->lsm->cmd_type) {
2865         case LTTNG_ADD_CONTEXT:
2866         {
2867                 ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
2868                                 cmd_ctx->lsm->u.context.channel_name,
2869                                 cmd_ctx->lsm->u.context.event_name,
2870                                 &cmd_ctx->lsm->u.context.ctx);
2871                 break;
2872         }
2873         case LTTNG_DISABLE_CHANNEL:
2874         {
2875                 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
2876                                 cmd_ctx->lsm->u.disable.channel_name);
2877                 break;
2878         }
2879         case LTTNG_DISABLE_EVENT:
2880         {
2881                 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
2882                                 cmd_ctx->lsm->u.disable.channel_name,
2883                                 cmd_ctx->lsm->u.disable.name);
2884                 ret = LTTCOMM_OK;
2885                 break;
2886         }
2887         case LTTNG_DISABLE_ALL_EVENT:
2888         {
2889                 DBG("Disabling all events");
2890
2891                 ret = cmd_disable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
2892                                 cmd_ctx->lsm->u.disable.channel_name);
2893                 break;
2894         }
2895         case LTTNG_ENABLE_CHANNEL:
2896         {
2897                 ret = cmd_enable_channel(cmd_ctx->session, &cmd_ctx->lsm->domain,
2898                                 &cmd_ctx->lsm->u.channel.chan);
2899                 break;
2900         }
2901         case LTTNG_ENABLE_EVENT:
2902         {
2903                 ret = cmd_enable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
2904                                 cmd_ctx->lsm->u.enable.channel_name,
2905                                 &cmd_ctx->lsm->u.enable.event);
2906                 break;
2907         }
2908         case LTTNG_ENABLE_ALL_EVENT:
2909         {
2910                 DBG("Enabling all events");
2911
2912                 ret = cmd_enable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
2913                                 cmd_ctx->lsm->u.enable.channel_name,
2914                                 cmd_ctx->lsm->u.enable.event.type);
2915                 break;
2916         }
2917         case LTTNG_LIST_TRACEPOINTS:
2918         {
2919                 struct lttng_event *events;
2920                 ssize_t nb_events;
2921
2922                 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
2923                 if (nb_events < 0) {
2924                         ret = -nb_events;
2925                         goto error;
2926                 }
2927
2928                 /*
2929                  * Setup lttng message with payload size set to the event list size in
2930                  * bytes and then copy list into the llm payload.
2931                  */
2932                 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
2933                 if (ret < 0) {
2934                         free(events);
2935                         goto setup_error;
2936                 }
2937
2938                 /* Copy event list into message payload */
2939                 memcpy(cmd_ctx->llm->payload, events,
2940                                 sizeof(struct lttng_event) * nb_events);
2941
2942                 free(events);
2943
2944                 ret = LTTCOMM_OK;
2945                 break;
2946         }
2947         case LTTNG_START_TRACE:
2948         {
2949                 ret = cmd_start_trace(cmd_ctx->session);
2950                 break;
2951         }
2952         case LTTNG_STOP_TRACE:
2953         {
2954                 ret = cmd_stop_trace(cmd_ctx->session);
2955                 break;
2956         }
2957         case LTTNG_CREATE_SESSION:
2958         {
2959                 ret = cmd_create_session(cmd_ctx->lsm->session.name,
2960                                 cmd_ctx->lsm->session.path);
2961                 break;
2962         }
2963         case LTTNG_DESTROY_SESSION:
2964         {
2965                 ret = cmd_destroy_session(cmd_ctx->session,
2966                                 cmd_ctx->lsm->session.name);
2967                 break;
2968         }
2969         case LTTNG_LIST_DOMAINS:
2970         {
2971                 ssize_t nb_dom;
2972                 struct lttng_domain *domains;
2973
2974                 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
2975                 if (nb_dom < 0) {
2976                         ret = -nb_dom;
2977                         goto error;
2978                 }
2979
2980                 ret = setup_lttng_msg(cmd_ctx, nb_dom * sizeof(struct lttng_domain));
2981                 if (ret < 0) {
2982                         goto setup_error;
2983                 }
2984
2985                 /* Copy event list into message payload */
2986                 memcpy(cmd_ctx->llm->payload, domains,
2987                                 nb_dom * sizeof(struct lttng_domain));
2988
2989                 free(domains);
2990
2991                 ret = LTTCOMM_OK;
2992                 break;
2993         }
2994         case LTTNG_LIST_CHANNELS:
2995         {
2996                 size_t nb_chan;
2997                 struct lttng_channel *channels;
2998
2999                 nb_chan = cmd_list_channels(cmd_ctx->session, &channels);
3000                 if (nb_chan < 0) {
3001                         ret = -nb_chan;
3002                         goto error;
3003                 }
3004
3005                 ret = setup_lttng_msg(cmd_ctx, nb_chan * sizeof(struct lttng_channel));
3006                 if (ret < 0) {
3007                         goto setup_error;
3008                 }
3009
3010                 /* Copy event list into message payload */
3011                 memcpy(cmd_ctx->llm->payload, channels,
3012                                 nb_chan * sizeof(struct lttng_channel));
3013
3014                 free(channels);
3015
3016                 ret = LTTCOMM_OK;
3017                 break;
3018         }
3019         case LTTNG_LIST_EVENTS:
3020         {
3021                 size_t nb_event;
3022                 struct lttng_event *events = NULL;
3023
3024                 nb_event = cmd_list_events(cmd_ctx->session,
3025                                 cmd_ctx->lsm->u.list.channel_name, &events);
3026                 if (nb_event < 0) {
3027                         ret = -nb_event;
3028                         goto error;
3029                 }
3030
3031                 ret = setup_lttng_msg(cmd_ctx, nb_event * sizeof(struct lttng_event));
3032                 if (ret < 0) {
3033                         goto setup_error;
3034                 }
3035
3036                 /* Copy event list into message payload */
3037                 memcpy(cmd_ctx->llm->payload, events,
3038                                 nb_event * sizeof(struct lttng_event));
3039
3040                 free(events);
3041
3042                 ret = LTTCOMM_OK;
3043                 break;
3044         }
3045         case LTTNG_LIST_SESSIONS:
3046         {
3047                 session_lock_list();
3048
3049                 if (session_list_ptr->count == 0) {
3050                         ret = LTTCOMM_NO_SESSION;
3051                         session_unlock_list();
3052                         goto error;
3053                 }
3054
3055                 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
3056                                 session_list_ptr->count);
3057                 if (ret < 0) {
3058                         session_unlock_list();
3059                         goto setup_error;
3060                 }
3061
3062                 /* Filled the session array */
3063                 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
3064
3065                 session_unlock_list();
3066
3067                 ret = LTTCOMM_OK;
3068                 break;
3069         }
3070         case LTTNG_CALIBRATE:
3071         {
3072                 ret = cmd_calibrate(cmd_ctx->lsm->domain.type,
3073                                 &cmd_ctx->lsm->u.calibrate);
3074                 break;
3075         }
3076         case LTTNG_REGISTER_CONSUMER:
3077         {
3078                 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3079                                 cmd_ctx->lsm->u.reg.path);
3080                 break;
3081         }
3082         default:
3083                 ret = LTTCOMM_UND;
3084                 break;
3085         }
3086
3087 error:
3088         if (cmd_ctx->llm == NULL) {
3089                 DBG("Missing llm structure. Allocating one.");
3090                 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
3091                         goto setup_error;
3092                 }
3093         }
3094         /* Set return code */
3095         cmd_ctx->llm->ret_code = ret;
3096 setup_error:
3097         if (cmd_ctx->session) {
3098                 session_unlock(cmd_ctx->session);
3099         }
3100 init_setup_error:
3101         return ret;
3102 }
3103
3104 /*
3105  * This thread manage all clients request using the unix client socket for
3106  * communication.
3107  */
3108 static void *thread_manage_clients(void *data)
3109 {
3110         int sock = 0, ret, i, pollfd;
3111         uint32_t revents, nb_fd;
3112         struct command_ctx *cmd_ctx = NULL;
3113         struct lttng_poll_event events;
3114
3115         DBG("[thread] Manage client started");
3116
3117         rcu_register_thread();
3118
3119         ret = lttcomm_listen_unix_sock(client_sock);
3120         if (ret < 0) {
3121                 goto error;
3122         }
3123
3124         /*
3125          * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
3126          * more will be added to this poll set.
3127          */
3128         ret = create_thread_poll_set(&events, 2);
3129         if (ret < 0) {
3130                 goto error;
3131         }
3132
3133         /* Add the application registration socket */
3134         ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
3135         if (ret < 0) {
3136                 goto error;
3137         }
3138
3139         /*
3140          * Notify parent pid that we are ready to accept command for client side.
3141          */
3142         if (opt_sig_parent) {
3143                 kill(ppid, SIGCHLD);
3144         }
3145
3146         while (1) {
3147                 DBG("Accepting client command ...");
3148
3149                 nb_fd = LTTNG_POLL_GETNB(&events);
3150
3151                 /* Inifinite blocking call, waiting for transmission */
3152                 ret = lttng_poll_wait(&events, -1);
3153                 if (ret < 0) {
3154                         goto error;
3155                 }
3156
3157                 for (i = 0; i < nb_fd; i++) {
3158                         /* Fetch once the poll data */
3159                         revents = LTTNG_POLL_GETEV(&events, i);
3160                         pollfd = LTTNG_POLL_GETFD(&events, i);
3161
3162                         /* Thread quit pipe has been closed. Killing thread. */
3163                         ret = check_thread_quit_pipe(pollfd, revents);
3164                         if (ret) {
3165                                 goto error;
3166                         }
3167
3168                         /* Event on the registration socket */
3169                         if (pollfd == client_sock) {
3170                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3171                                         ERR("Client socket poll error");
3172                                         goto error;
3173                                 }
3174                         }
3175                 }
3176
3177                 DBG("Wait for client response");
3178
3179                 sock = lttcomm_accept_unix_sock(client_sock);
3180                 if (sock < 0) {
3181                         goto error;
3182                 }
3183
3184                 /* Allocate context command to process the client request */
3185                 cmd_ctx = malloc(sizeof(struct command_ctx));
3186                 if (cmd_ctx == NULL) {
3187                         perror("malloc cmd_ctx");
3188                         goto error;
3189                 }
3190
3191                 /* Allocate data buffer for reception */
3192                 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
3193                 if (cmd_ctx->lsm == NULL) {
3194                         perror("malloc cmd_ctx->lsm");
3195                         goto error;
3196                 }
3197
3198                 cmd_ctx->llm = NULL;
3199                 cmd_ctx->session = NULL;
3200
3201                 /*
3202                  * Data is received from the lttng client. The struct
3203                  * lttcomm_session_msg (lsm) contains the command and data request of
3204                  * the client.
3205                  */
3206                 DBG("Receiving data from client ...");
3207                 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm,
3208                                 sizeof(struct lttcomm_session_msg));
3209                 if (ret <= 0) {
3210                         DBG("Nothing recv() from client... continuing");
3211                         close(sock);
3212                         free(cmd_ctx);
3213                         continue;
3214                 }
3215
3216                 // TODO: Validate cmd_ctx including sanity check for
3217                 // security purpose.
3218
3219                 rcu_thread_online();
3220                 /*
3221                  * This function dispatch the work to the kernel or userspace tracer
3222                  * libs and fill the lttcomm_lttng_msg data structure of all the needed
3223                  * informations for the client. The command context struct contains
3224                  * everything this function may needs.
3225                  */
3226                 ret = process_client_msg(cmd_ctx);
3227                 rcu_thread_offline();
3228                 if (ret < 0) {
3229                         /*
3230                          * TODO: Inform client somehow of the fatal error. At
3231                          * this point, ret < 0 means that a malloc failed
3232                          * (ENOMEM). Error detected but still accept command.
3233                          */
3234                         clean_command_ctx(&cmd_ctx);
3235                         continue;
3236                 }
3237
3238                 DBG("Sending response (size: %d, retcode: %s)",
3239                                 cmd_ctx->lttng_msg_size,
3240                                 lttng_strerror(-cmd_ctx->llm->ret_code));
3241                 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
3242                 if (ret < 0) {
3243                         ERR("Failed to send data back to client");
3244                 }
3245
3246                 clean_command_ctx(&cmd_ctx);
3247
3248                 /* End of transmission */
3249                 close(sock);
3250         }
3251
3252 error:
3253         DBG("Client thread dying");
3254         unlink(client_unix_sock_path);
3255         close(client_sock);
3256         close(sock);
3257
3258         lttng_poll_clean(&events);
3259         clean_command_ctx(&cmd_ctx);
3260
3261         rcu_unregister_thread();
3262         return NULL;
3263 }
3264
3265
3266 /*
3267  * usage function on stderr
3268  */
3269 static void usage(void)
3270 {
3271         fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
3272         fprintf(stderr, "  -h, --help                         Display this usage.\n");
3273         fprintf(stderr, "  -c, --client-sock PATH             Specify path for the client unix socket\n");
3274         fprintf(stderr, "  -a, --apps-sock PATH               Specify path for apps unix socket\n");
3275         fprintf(stderr, "      --kconsumerd-err-sock PATH     Specify path for the kernel consumer error socket\n");
3276         fprintf(stderr, "      --kconsumerd-cmd-sock PATH     Specify path for the kernel consumer command socket\n");
3277         fprintf(stderr, "      --ustconsumerd-err-sock PATH   Specify path for the UST consumer error socket\n");
3278         fprintf(stderr, "      --ustconsumerd-cmd-sock PATH   Specify path for the UST consumer command socket\n");
3279         fprintf(stderr, "  -d, --daemonize                    Start as a daemon.\n");
3280         fprintf(stderr, "  -g, --group NAME                   Specify the tracing group name. (default: tracing)\n");
3281         fprintf(stderr, "  -V, --version                      Show version number.\n");
3282         fprintf(stderr, "  -S, --sig-parent                   Send SIGCHLD to parent pid to notify readiness.\n");
3283         fprintf(stderr, "  -q, --quiet                        No output at all.\n");
3284         fprintf(stderr, "  -v, --verbose                      Verbose mode. Activate DBG() macro.\n");
3285         fprintf(stderr, "      --verbose-consumer             Verbose mode for consumer. Activate DBG() macro.\n");
3286 }
3287
3288 /*
3289  * daemon argument parsing
3290  */
3291 static int parse_args(int argc, char **argv)
3292 {
3293         int c;
3294
3295         static struct option long_options[] = {
3296                 { "client-sock", 1, 0, 'c' },
3297                 { "apps-sock", 1, 0, 'a' },
3298                 { "kconsumerd-cmd-sock", 1, 0, 'C' },
3299                 { "kconsumerd-err-sock", 1, 0, 'E' },
3300                 { "ustconsumerd-cmd-sock", 1, 0, 'D' },
3301                 { "ustconsumerd-err-sock", 1, 0, 'F' },
3302                 { "daemonize", 0, 0, 'd' },
3303                 { "sig-parent", 0, 0, 'S' },
3304                 { "help", 0, 0, 'h' },
3305                 { "group", 1, 0, 'g' },
3306                 { "version", 0, 0, 'V' },
3307                 { "quiet", 0, 0, 'q' },
3308                 { "verbose", 0, 0, 'v' },
3309                 { "verbose-consumer", 0, 0, 'Z' },
3310                 { NULL, 0, 0, 0 }
3311         };
3312
3313         while (1) {
3314                 int option_index = 0;
3315                 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:C:E:D:F:Z",
3316                                 long_options, &option_index);
3317                 if (c == -1) {
3318                         break;
3319                 }
3320
3321                 switch (c) {
3322                 case 0:
3323                         fprintf(stderr, "option %s", long_options[option_index].name);
3324                         if (optarg) {
3325                                 fprintf(stderr, " with arg %s\n", optarg);
3326                         }
3327                         break;
3328                 case 'c':
3329                         snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
3330                         break;
3331                 case 'a':
3332                         snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
3333                         break;
3334                 case 'd':
3335                         opt_daemon = 1;
3336                         break;
3337                 case 'g':
3338                         opt_tracing_group = strdup(optarg);
3339                         break;
3340                 case 'h':
3341                         usage();
3342                         exit(EXIT_FAILURE);
3343                 case 'V':
3344                         fprintf(stdout, "%s\n", VERSION);
3345                         exit(EXIT_SUCCESS);
3346                 case 'S':
3347                         opt_sig_parent = 1;
3348                         break;
3349                 case 'E':
3350                         snprintf(kconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
3351                         break;
3352                 case 'C':
3353                         snprintf(kconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
3354                         break;
3355                 case 'F':
3356                         snprintf(ustconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
3357                         break;
3358                 case 'D':
3359                         snprintf(ustconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
3360                         break;
3361                 case 'q':
3362                         opt_quiet = 1;
3363                         break;
3364                 case 'v':
3365                         /* Verbose level can increase using multiple -v */
3366                         opt_verbose += 1;
3367                         break;
3368                 case 'Z':
3369                         opt_verbose_consumer += 1;
3370                         break;
3371                 default:
3372                         /* Unknown option or other error.
3373                          * Error is printed by getopt, just return */
3374                         return -1;
3375                 }
3376         }
3377
3378         return 0;
3379 }
3380
3381 /*
3382  * Creates the two needed socket by the daemon.
3383  *          apps_sock - The communication socket for all UST apps.
3384  *          client_sock - The communication of the cli tool (lttng).
3385  */
3386 static int init_daemon_socket(void)
3387 {
3388         int ret = 0;
3389         mode_t old_umask;
3390
3391         old_umask = umask(0);
3392
3393         /* Create client tool unix socket */
3394         client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
3395         if (client_sock < 0) {
3396                 ERR("Create unix sock failed: %s", client_unix_sock_path);
3397                 ret = -1;
3398                 goto end;
3399         }
3400
3401         /* File permission MUST be 660 */
3402         ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3403         if (ret < 0) {
3404                 ERR("Set file permissions failed: %s", client_unix_sock_path);
3405                 perror("chmod");
3406                 goto end;
3407         }
3408
3409         /* Create the application unix socket */
3410         apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
3411         if (apps_sock < 0) {
3412                 ERR("Create unix sock failed: %s", apps_unix_sock_path);
3413                 ret = -1;
3414                 goto end;
3415         }
3416
3417         /* File permission MUST be 666 */
3418         ret = chmod(apps_unix_sock_path,
3419                         S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
3420         if (ret < 0) {
3421                 ERR("Set file permissions failed: %s", apps_unix_sock_path);
3422                 perror("chmod");
3423                 goto end;
3424         }
3425
3426 end:
3427         umask(old_umask);
3428         return ret;
3429 }
3430
3431 /*
3432  * Check if the global socket is available, and if a daemon is answering at the
3433  * other side. If yes, error is returned.
3434  */
3435 static int check_existing_daemon(void)
3436 {
3437         if (access(client_unix_sock_path, F_OK) < 0 &&
3438                         access(apps_unix_sock_path, F_OK) < 0) {
3439                 return 0;
3440         }
3441
3442         /* Is there anybody out there ? */
3443         if (lttng_session_daemon_alive()) {
3444                 return -EEXIST;
3445         } else {
3446                 return 0;
3447         }
3448 }
3449
3450 /*
3451  * Set the tracing group gid onto the client socket.
3452  *
3453  * Race window between mkdir and chown is OK because we are going from more
3454  * permissive (root.root) to les permissive (root.tracing).
3455  */
3456 static int set_permissions(void)
3457 {
3458         int ret;
3459         gid_t gid;
3460
3461         gid = allowed_group();
3462         if (gid < 0) {
3463                 if (is_root) {
3464                         WARN("No tracing group detected");
3465                         ret = 0;
3466                 } else {
3467                         ERR("Missing tracing group. Aborting execution.");
3468                         ret = -1;
3469                 }
3470                 goto end;
3471         }
3472
3473         /* Set lttng run dir */
3474         ret = chown(LTTNG_RUNDIR, 0, gid);
3475         if (ret < 0) {
3476                 ERR("Unable to set group on " LTTNG_RUNDIR);
3477                 perror("chown");
3478         }
3479
3480         /* lttng client socket path */
3481         ret = chown(client_unix_sock_path, 0, gid);
3482         if (ret < 0) {
3483                 ERR("Unable to set group on %s", client_unix_sock_path);
3484                 perror("chown");
3485         }
3486
3487         /* kconsumer error socket path */
3488         ret = chown(kconsumer_data.err_unix_sock_path, 0, gid);
3489         if (ret < 0) {
3490                 ERR("Unable to set group on %s", kconsumer_data.err_unix_sock_path);
3491                 perror("chown");
3492         }
3493
3494         /* ustconsumer error socket path */
3495         ret = chown(ustconsumer_data.err_unix_sock_path, 0, gid);
3496         if (ret < 0) {
3497                 ERR("Unable to set group on %s", ustconsumer_data.err_unix_sock_path);
3498                 perror("chown");
3499         }
3500
3501         DBG("All permissions are set");
3502
3503 end:
3504         return ret;
3505 }
3506
3507 /*
3508  * Create the pipe used to wake up the kernel thread.
3509  */
3510 static int create_kernel_poll_pipe(void)
3511 {
3512         return pipe2(kernel_poll_pipe, O_CLOEXEC);
3513 }
3514
3515 /*
3516  * Create the application command pipe to wake thread_manage_apps.
3517  */
3518 static int create_apps_cmd_pipe(void)
3519 {
3520         return pipe2(apps_cmd_pipe, O_CLOEXEC);
3521 }
3522
3523 /*
3524  * Create the lttng run directory needed for all global sockets and pipe.
3525  */
3526 static int create_lttng_rundir(void)
3527 {
3528         int ret;
3529
3530         ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
3531         if (ret < 0) {
3532                 if (errno != EEXIST) {
3533                         ERR("Unable to create " LTTNG_RUNDIR);
3534                         goto error;
3535                 } else {
3536                         ret = 0;
3537                 }
3538         }
3539
3540 error:
3541         return ret;
3542 }
3543
3544 /*
3545  * Setup sockets and directory needed by the kconsumerd communication with the
3546  * session daemon.
3547  */
3548 static int set_consumer_sockets(struct consumer_data *consumer_data)
3549 {
3550         int ret;
3551         const char *path = consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3552                         KCONSUMERD_PATH : USTCONSUMERD_PATH;
3553
3554         if (strlen(consumer_data->err_unix_sock_path) == 0) {
3555                 snprintf(consumer_data->err_unix_sock_path, PATH_MAX,
3556                         consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3557                                 KCONSUMERD_ERR_SOCK_PATH :
3558                                 USTCONSUMERD_ERR_SOCK_PATH);
3559         }
3560
3561         if (strlen(consumer_data->cmd_unix_sock_path) == 0) {
3562                 snprintf(consumer_data->cmd_unix_sock_path, PATH_MAX,
3563                         consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3564                                 KCONSUMERD_CMD_SOCK_PATH :
3565                                 USTCONSUMERD_CMD_SOCK_PATH);
3566         }
3567
3568         ret = mkdir(path, S_IRWXU | S_IRWXG);
3569         if (ret < 0) {
3570                 if (errno != EEXIST) {
3571                         ERR("Failed to create %s", path);
3572                         goto error;
3573                 }
3574                 ret = 0;
3575         }
3576
3577         /* Create the kconsumerd error unix socket */
3578         consumer_data->err_sock =
3579                 lttcomm_create_unix_sock(consumer_data->err_unix_sock_path);
3580         if (consumer_data->err_sock < 0) {
3581                 ERR("Create unix sock failed: %s", consumer_data->err_unix_sock_path);
3582                 ret = -1;
3583                 goto error;
3584         }
3585
3586         /* File permission MUST be 660 */
3587         ret = chmod(consumer_data->err_unix_sock_path,
3588                         S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3589         if (ret < 0) {
3590                 ERR("Set file permissions failed: %s", consumer_data->err_unix_sock_path);
3591                 perror("chmod");
3592                 goto error;
3593         }
3594
3595 error:
3596         return ret;
3597 }
3598
3599 /*
3600  * Signal handler for the daemon
3601  *
3602  * Simply stop all worker threads, leaving main() return gracefully after
3603  * joining all threads and calling cleanup().
3604  */
3605 static void sighandler(int sig)
3606 {
3607         switch (sig) {
3608         case SIGPIPE:
3609                 DBG("SIGPIPE catched");
3610                 return;
3611         case SIGINT:
3612                 DBG("SIGINT catched");
3613                 stop_threads();
3614                 break;
3615         case SIGTERM:
3616                 DBG("SIGTERM catched");
3617                 stop_threads();
3618                 break;
3619         default:
3620                 break;
3621         }
3622 }
3623
3624 /*
3625  * Setup signal handler for :
3626  *              SIGINT, SIGTERM, SIGPIPE
3627  */
3628 static int set_signal_handler(void)
3629 {
3630         int ret = 0;
3631         struct sigaction sa;
3632         sigset_t sigset;
3633
3634         if ((ret = sigemptyset(&sigset)) < 0) {
3635                 perror("sigemptyset");
3636                 return ret;
3637         }
3638
3639         sa.sa_handler = sighandler;
3640         sa.sa_mask = sigset;
3641         sa.sa_flags = 0;
3642         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
3643                 perror("sigaction");
3644                 return ret;
3645         }
3646
3647         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
3648                 perror("sigaction");
3649                 return ret;
3650         }
3651
3652         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
3653                 perror("sigaction");
3654                 return ret;
3655         }
3656
3657         DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
3658
3659         return ret;
3660 }
3661
3662 /*
3663  * Set open files limit to unlimited. This daemon can open a large number of
3664  * file descriptors in order to consumer multiple kernel traces.
3665  */
3666 static void set_ulimit(void)
3667 {
3668         int ret;
3669         struct rlimit lim;
3670
3671         /* The kernel does not allowed an infinite limit for open files */
3672         lim.rlim_cur = 65535;
3673         lim.rlim_max = 65535;
3674
3675         ret = setrlimit(RLIMIT_NOFILE, &lim);
3676         if (ret < 0) {
3677                 perror("failed to set open files limit");
3678         }
3679 }
3680
3681 /*
3682  * main
3683  */
3684 int main(int argc, char **argv)
3685 {
3686         int ret = 0;
3687         void *status;
3688         const char *home_path;
3689
3690         rcu_register_thread();
3691
3692         /* Create thread quit pipe */
3693         if ((ret = init_thread_quit_pipe()) < 0) {
3694                 goto error;
3695         }
3696
3697         /* Parse arguments */
3698         progname = argv[0];
3699         if ((ret = parse_args(argc, argv) < 0)) {
3700                 goto error;
3701         }
3702
3703         /* Daemonize */
3704         if (opt_daemon) {
3705                 ret = daemon(0, 0);
3706                 if (ret < 0) {
3707                         perror("daemon");
3708                         goto error;
3709                 }
3710         }
3711
3712         /* Check if daemon is UID = 0 */
3713         is_root = !getuid();
3714
3715         if (is_root) {
3716                 ret = create_lttng_rundir();
3717                 if (ret < 0) {
3718                         goto error;
3719                 }
3720
3721                 if (strlen(apps_unix_sock_path) == 0) {
3722                         snprintf(apps_unix_sock_path, PATH_MAX,
3723                                         DEFAULT_GLOBAL_APPS_UNIX_SOCK);
3724                 }
3725
3726                 if (strlen(client_unix_sock_path) == 0) {
3727                         snprintf(client_unix_sock_path, PATH_MAX,
3728                                         DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
3729                 }
3730
3731                 /* Set global SHM for ust */
3732                 if (strlen(wait_shm_path) == 0) {
3733                         snprintf(wait_shm_path, PATH_MAX,
3734                                         DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH);
3735                 }
3736         } else {
3737                 home_path = get_home_dir();
3738                 if (home_path == NULL) {
3739                         /* TODO: Add --socket PATH option */
3740                         ERR("Can't get HOME directory for sockets creation.");
3741                         ret = -EPERM;
3742                         goto error;
3743                 }
3744
3745                 if (strlen(apps_unix_sock_path) == 0) {
3746                         snprintf(apps_unix_sock_path, PATH_MAX,
3747                                         DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
3748                 }
3749
3750                 /* Set the cli tool unix socket path */
3751                 if (strlen(client_unix_sock_path) == 0) {
3752                         snprintf(client_unix_sock_path, PATH_MAX,
3753                                         DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
3754                 }
3755
3756                 /* Set global SHM for ust */
3757                 if (strlen(wait_shm_path) == 0) {
3758                         snprintf(wait_shm_path, PATH_MAX,
3759                                         DEFAULT_HOME_APPS_WAIT_SHM_PATH, geteuid());
3760                 }
3761         }
3762
3763         DBG("Client socket path %s", client_unix_sock_path);
3764         DBG("Application socket path %s", apps_unix_sock_path);
3765
3766         /*
3767          * See if daemon already exist.
3768          */
3769         if ((ret = check_existing_daemon()) < 0) {
3770                 ERR("Already running daemon.\n");
3771                 /*
3772                  * We do not goto exit because we must not cleanup()
3773                  * because a daemon is already running.
3774                  */
3775                 goto error;
3776         }
3777
3778         /* After this point, we can safely call cleanup() with "goto exit" */
3779
3780         /*
3781          * These actions must be executed as root. We do that *after* setting up
3782          * the sockets path because we MUST make the check for another daemon using
3783          * those paths *before* trying to set the kernel consumer sockets and init
3784          * kernel tracer.
3785          */
3786         if (is_root) {
3787                 ret = set_consumer_sockets(&kconsumer_data);
3788                 if (ret < 0) {
3789                         goto exit;
3790                 }
3791
3792                 ret = set_consumer_sockets(&ustconsumer_data);
3793                 if (ret < 0) {
3794                         goto exit;
3795                 }
3796                 /* Setup kernel tracer */
3797                 init_kernel_tracer();
3798
3799                 /* Set ulimit for open files */
3800                 set_ulimit();
3801         }
3802
3803         if ((ret = set_signal_handler()) < 0) {
3804                 goto exit;
3805         }
3806
3807         /* Setup the needed unix socket */
3808         if ((ret = init_daemon_socket()) < 0) {
3809                 goto exit;
3810         }
3811
3812         /* Set credentials to socket */
3813         if (is_root && ((ret = set_permissions()) < 0)) {
3814                 goto exit;
3815         }
3816
3817         /* Get parent pid if -S, --sig-parent is specified. */
3818         if (opt_sig_parent) {
3819                 ppid = getppid();
3820         }
3821
3822         /* Setup the kernel pipe for waking up the kernel thread */
3823         if ((ret = create_kernel_poll_pipe()) < 0) {
3824                 goto exit;
3825         }
3826
3827         /* Setup the thread apps communication pipe. */
3828         if ((ret = create_apps_cmd_pipe()) < 0) {
3829                 goto exit;
3830         }
3831
3832         /* Init UST command queue. */
3833         cds_wfq_init(&ust_cmd_queue.queue);
3834
3835         /* Init UST app hash table */
3836         ust_app_ht_alloc();
3837
3838         /*
3839          * Get session list pointer. This pointer MUST NOT be free(). This list is
3840          * statically declared in session.c
3841          */
3842         session_list_ptr = session_get_list();
3843
3844         /* Set up max poll set size */
3845         lttng_poll_set_max_size();
3846
3847         /* Create thread to manage the client socket */
3848         ret = pthread_create(&client_thread, NULL,
3849                         thread_manage_clients, (void *) NULL);
3850         if (ret != 0) {
3851                 perror("pthread_create clients");
3852                 goto exit_client;
3853         }
3854
3855         /* Create thread to dispatch registration */
3856         ret = pthread_create(&dispatch_thread, NULL,
3857                         thread_dispatch_ust_registration, (void *) NULL);
3858         if (ret != 0) {
3859                 perror("pthread_create dispatch");
3860                 goto exit_dispatch;
3861         }
3862
3863         /* Create thread to manage application registration. */
3864         ret = pthread_create(&reg_apps_thread, NULL,
3865                         thread_registration_apps, (void *) NULL);
3866         if (ret != 0) {
3867                 perror("pthread_create registration");
3868                 goto exit_reg_apps;
3869         }
3870
3871         /* Create thread to manage application socket */
3872         ret = pthread_create(&apps_thread, NULL,
3873                         thread_manage_apps, (void *) NULL);
3874         if (ret != 0) {
3875                 perror("pthread_create apps");
3876                 goto exit_apps;
3877         }
3878
3879         /* Create kernel thread to manage kernel event */
3880         ret = pthread_create(&kernel_thread, NULL,
3881                         thread_manage_kernel, (void *) NULL);
3882         if (ret != 0) {
3883                 perror("pthread_create kernel");
3884                 goto exit_kernel;
3885         }
3886
3887         ret = pthread_join(kernel_thread, &status);
3888         if (ret != 0) {
3889                 perror("pthread_join");
3890                 goto error;     /* join error, exit without cleanup */
3891         }
3892
3893 exit_kernel:
3894         ret = pthread_join(apps_thread, &status);
3895         if (ret != 0) {
3896                 perror("pthread_join");
3897                 goto error;     /* join error, exit without cleanup */
3898         }
3899
3900 exit_apps:
3901         ret = pthread_join(reg_apps_thread, &status);
3902         if (ret != 0) {
3903                 perror("pthread_join");
3904                 goto error;     /* join error, exit without cleanup */
3905         }
3906
3907 exit_reg_apps:
3908         ret = pthread_join(dispatch_thread, &status);
3909         if (ret != 0) {
3910                 perror("pthread_join");
3911                 goto error;     /* join error, exit without cleanup */
3912         }
3913
3914 exit_dispatch:
3915         ret = pthread_join(client_thread, &status);
3916         if (ret != 0) {
3917                 perror("pthread_join");
3918                 goto error;     /* join error, exit without cleanup */
3919         }
3920
3921         ret = join_consumer_thread(&kconsumer_data);
3922         if (ret != 0) {
3923                 perror("join_consumer");
3924                 goto error;     /* join error, exit without cleanup */
3925         }
3926
3927 exit_client:
3928 exit:
3929         /*
3930          * cleanup() is called when no other thread is running.
3931          */
3932         rcu_thread_online();
3933         cleanup();
3934         rcu_thread_offline();
3935         rcu_unregister_thread();
3936         if (!ret)
3937                 exit(EXIT_SUCCESS);
3938 error:
3939         exit(EXIT_FAILURE);
3940 }