+ int ret;
+ pid_t pid;
+
+ DBG("Spawning kconsumerd");
+
+ pid = fork();
+ if (pid == 0) {
+ /*
+ * Exec kconsumerd.
+ */
+ execlp("kconsumerd", "kconsumerd", "--verbose", NULL);
+ if (errno != 0) {
+ perror("kernel start consumer exec");
+ }
+ exit(EXIT_FAILURE);
+ } else if (pid > 0) {
+ ret = pid;
+ goto error;
+ } else {
+ perror("kernel start consumer fork");
+ ret = -errno;
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * start_kconsumerd
+ *
+ * Spawn the kconsumerd daemon and session daemon thread.
+ */
+static int start_kconsumerd(void)
+{
+ int ret;
+
+ pthread_mutex_lock(&kconsumerd_pid_mutex);
+ if (kconsumerd_pid != 0) {
+ goto end;
+ }
+
+ ret = spawn_kconsumerd();
+ if (ret < 0) {
+ ERR("Spawning kconsumerd failed");
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+ goto error;
+ }
+
+ /* Setting up the global kconsumerd_pid */
+ kconsumerd_pid = ret;
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+
+ DBG("Kconsumerd pid %d", ret);
+
+ DBG("Spawning kconsumerd thread");
+ ret = spawn_kconsumerd_thread();
+ if (ret < 0) {
+ ERR("Fatal error spawning kconsumerd thread");
+ goto error;
+ }
+
+end:
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * send_kconsumerd_fds
+ *
+ * Send all stream fds of the kernel session to the consumer.
+ */
+static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session)
+{
+ int ret;
+ size_t nb_fd;
+ struct ltt_kernel_stream *stream;
+ struct ltt_kernel_channel *chan;
+ struct lttcomm_kconsumerd_header lkh;
+ struct lttcomm_kconsumerd_msg lkm;
+
+ nb_fd = session->stream_count_global;
+
+ /* Setup header */
+ lkh.payload_size = (nb_fd + 1) * sizeof(struct lttcomm_kconsumerd_msg);
+ lkh.cmd_type = ADD_STREAM;
+
+ DBG("Sending kconsumerd header");
+
+ ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
+ if (ret < 0) {
+ perror("send kconsumerd header");
+ goto error;
+ }
+
+ DBG("Sending metadata stream fd");
+
+ /* Send metadata stream fd first */
+ lkm.fd = session->metadata_stream_fd;
+ lkm.state = ACTIVE_FD;
+ lkm.max_sb_size = session->metadata->conf->subbuf_size;
+ strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
+
+ ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
+ if (ret < 0) {
+ perror("send kconsumerd fd");
+ goto error;
+ }
+
+ cds_list_for_each_entry(chan, &session->channel_list.head, list) {
+ cds_list_for_each_entry(stream, &chan->stream_list.head, list) {
+ lkm.fd = stream->fd;
+ lkm.state = stream->state;
+ lkm.max_sb_size = chan->channel->subbuf_size;
+ strncpy(lkm.path_name, stream->pathname, PATH_MAX);
+
+ DBG("Sending fd %d to kconsumerd", lkm.fd);
+
+ ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
+ if (ret < 0) {
+ perror("send kconsumerd fd");
+ goto error;
+ }
+ }
+ }
+
+ DBG("Kconsumerd fds sent");
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * create_trace_dir
+ *
+ * Create the trace output directory.
+ */
+static int create_trace_dir(struct ltt_kernel_session *session)
+{
+ int ret;
+ struct ltt_kernel_channel *chan;
+
+ /* Create all channel directories */
+ cds_list_for_each_entry(chan, &session->channel_list.head, list) {
+ DBG("Creating trace directory at %s", chan->pathname);
+ // TODO: recursive create dir
+ ret = mkdir(chan->pathname, S_IRWXU | S_IRWXG );
+ if (ret < 0) {
+ if (ret != EEXIST) {
+ perror("mkdir trace path");
+ ret = -errno;
+ goto error;
+ }
+ }
+ }
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * init_kernel_tracer
+ *
+ * Setup necessary data for kernel tracer action.
+ */
+static void init_kernel_tracer(void)
+{
+ /* Set the global kernel tracer fd */
+ kernel_tracer_fd = open(DEFAULT_KERNEL_TRACER_PATH, O_RDWR);
+ if (kernel_tracer_fd < 0) {
+ WARN("No kernel tracer available");
+ kernel_tracer_fd = 0;
+ }
+
+ DBG("Kernel tracer fd %d", kernel_tracer_fd);
+}
+
+/*
+ * process_client_msg
+ *
+ * Process the command requested by the lttng client within the command
+ * context structure. This function make sure that the return structure (llm)
+ * is set and ready for transmission before returning.
+ *
+ * Return any error encountered or 0 for success.
+ */
+static int process_client_msg(struct command_ctx *cmd_ctx)
+{
+ int ret;
+
+ DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
+
+ /* Check command that needs a session */
+ switch (cmd_ctx->lsm->cmd_type) {
+ case LTTNG_CREATE_SESSION:
+ case LTTNG_LIST_SESSIONS:
+ case KERNEL_LIST_EVENTS:
+ case UST_LIST_APPS:
+ break;
+ default:
+ cmd_ctx->session = find_session_by_uuid(cmd_ctx->lsm->session_uuid);
+ if (cmd_ctx->session == NULL) {
+ ret = LTTCOMM_SELECT_SESS;
+ goto error;
+ }
+ break;
+ }
+
+ /* Check command for kernel tracing */
+ switch (cmd_ctx->lsm->cmd_type) {
+ case KERNEL_CREATE_SESSION:
+ case KERNEL_CREATE_CHANNEL:
+ case KERNEL_CREATE_STREAM:
+ case KERNEL_DISABLE_EVENT:
+ case KERNEL_ENABLE_EVENT:
+ case KERNEL_LIST_EVENTS:
+ case KERNEL_OPEN_METADATA:
+ case KERNEL_START_TRACE:
+ case KERNEL_STOP_TRACE:
+ /* Kernel tracer check */
+ if (kernel_tracer_fd == 0) {
+ init_kernel_tracer();
+ if (kernel_tracer_fd == 0) {
+ ret = LTTCOMM_KERN_NA;
+ goto error;
+ }
+ }
+ break;
+ }
+
+ /* Connect to ust apps if available pid */
+ if (cmd_ctx->lsm->pid > 0) {
+ /* Connect to app using ustctl API */
+ cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid);
+ if (cmd_ctx->ust_sock < 0) {
+ ret = LTTCOMM_NO_TRACEABLE;
+ goto error;
+ }
+ }
+
+ /* Process by command type */
+ switch (cmd_ctx->lsm->cmd_type) {
+ case KERNEL_CREATE_SESSION:
+ {
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ ret = start_kconsumerd();
+ if (ret < 0) {
+ goto error;
+ }
+
+ DBG("Creating kernel session");
+
+ ret = kernel_create_session(cmd_ctx->session, kernel_tracer_fd);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_SESS_FAIL;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case KERNEL_CREATE_CHANNEL:
+ {
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ DBG("Creating kernel channel");
+
+ ret = kernel_create_channel(cmd_ctx->session->kernel_session);
+
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_CHAN_FAIL;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case KERNEL_ENABLE_EVENT:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ DBG("Enabling kernel event %s", cmd_ctx->lsm->u.event.event_name);
+
+ ret = kernel_enable_event(cmd_ctx->session->kernel_session, cmd_ctx->lsm->u.event.event_name);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_ENABLE_FAIL;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case KERNEL_ENABLE_ALL_EVENT:
+ {
+ int pos, size;
+ char *event_list, *event, *ptr;
+
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ DBG("Enabling all kernel event");
+
+ size = kernel_list_events(kernel_tracer_fd, &event_list);
+ if (size < 0) {
+ ret = LTTCOMM_KERN_LIST_FAIL;
+ goto error;
+ }
+
+ ptr = event_list;
+ while ((size = sscanf(ptr, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
+ /* Enable each single event */
+ ret = kernel_enable_event(cmd_ctx->session->kernel_session, event);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_ENABLE_FAIL;
+ goto error;
+ }
+ /* Move pointer to the next line */
+ ptr += pos + 1;
+ free(event);
+ }
+
+ free(event_list);
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case KERNEL_LIST_EVENTS:
+ {
+ char *event_list;
+ ssize_t size;
+
+ size = kernel_list_events(kernel_tracer_fd, &event_list);
+ if (size < 0) {
+ ret = LTTCOMM_KERN_LIST_FAIL;
+ goto error;
+ }
+
+ /*
+ * Setup lttng message with payload size set to the event list size in
+ * bytes and then copy list into the llm payload.
+ */
+ ret = setup_lttng_msg(cmd_ctx, size);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Copy event list into message payload */
+ memcpy(cmd_ctx->llm->payload, event_list, size);
+
+ free(event_list);
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case KERNEL_OPEN_METADATA:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ DBG("Open kernel metadata");
+
+ ret = kernel_open_metadata(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_META_FAIL;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case KERNEL_CREATE_STREAM:
+ {
+ struct ltt_kernel_channel *chan;
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ DBG("Creating kernel stream");
+
+ ret = kernel_create_metadata_stream(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ERR("Kernel create metadata stream failed");
+ ret = LTTCOMM_KERN_STREAM_FAIL;
+ goto error;
+ }
+
+ /* For each channel */
+ cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
+ ret = kernel_create_channel_stream(chan);
+ if (ret < 0) {
+ ERR("Kernel create channel stream failed");
+ ret = LTTCOMM_KERN_STREAM_FAIL;
+ goto error;
+ }
+ /* Update the stream global counter */
+ cmd_ctx->session->kernel_session->stream_count_global += ret;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case KERNEL_START_TRACE:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ DBG("Start kernel tracing");
+
+ ret = create_trace_dir(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ if (ret == -EEXIST) {
+ ret = LTTCOMM_KERN_DIR_EXIST;
+ } else {
+ ret = LTTCOMM_KERN_DIR_FAIL;
+ goto error;
+ }
+ }
+
+ ret = kernel_start_session(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ERR("Kernel start session failed");
+ ret = LTTCOMM_KERN_START_FAIL;
+ goto error;
+ }
+
+ ret = send_kconsumerd_fds(kconsumerd_cmd_sock, cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ERR("Send kconsumerd fds failed");
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case KERNEL_STOP_TRACE:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ if (cmd_ctx->session->kernel_session == NULL) {
+ ret = LTTCOMM_KERN_NO_SESSION;
+ goto error;
+ }
+
+ DBG("Stop kernel tracing");
+
+ ret = kernel_stop_session(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ERR("Kernel stop session failed");
+ ret = LTTCOMM_KERN_STOP_FAIL;
+ goto error;
+ }
+
+ /* Clean kernel session teardown */
+ teardown_kernel_session(cmd_ctx->session);
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_CREATE_SESSION:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ ret = create_session(cmd_ctx->lsm->session_name, &cmd_ctx->llm->session_uuid);
+ if (ret < 0) {
+ if (ret == -1) {
+ ret = LTTCOMM_EXIST_SESS;
+ } else {
+ ret = LTTCOMM_FATAL;
+ }
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_DESTROY_SESSION:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ ret = destroy_session(&cmd_ctx->lsm->session_uuid);
+ if (ret < 0) {
+ ret = LTTCOMM_NO_SESS;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_LIST_TRACES:
+ {
+ unsigned int trace_count;
+
+ trace_count = get_trace_count_per_session(cmd_ctx->session);
+ if (trace_count == 0) {
+ ret = LTTCOMM_NO_TRACE;
+ goto error;
+ }
+
+ ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ get_traces_per_session(cmd_ctx->session,
+ (struct lttng_trace *)(cmd_ctx->llm->payload));
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case UST_CREATE_TRACE:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ ret = ust_create_trace(cmd_ctx);
+ if (ret < 0) {
+ goto setup_error;
+ }
+ break;
+ }
+ case UST_LIST_APPS:
+ {
+ unsigned int app_count;
+
+ app_count = get_app_count();
+ DBG("Traceable application count : %d", app_count);
+ if (app_count == 0) {
+ ret = LTTCOMM_NO_APPS;
+ goto error;
+ }
+
+ ret = setup_lttng_msg(cmd_ctx, sizeof(pid_t) * app_count);
+ if (ret < 0) {
+ goto setup_error;
+ }