+ return nb_events;
+
+error:
+ /* Return negative value to differentiate return code */
+ return -ret;
+}
+
+/*
+ * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
+ */
+ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
+ struct lttng_event_field **fields)
+{
+ int ret;
+ ssize_t nb_fields = 0;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_UST:
+ nb_fields = ust_app_list_event_fields(fields);
+ if (nb_fields < 0) {
+ ret = LTTNG_ERR_UST_LIST_FAIL;
+ goto error;
+ }
+ break;
+ case LTTNG_DOMAIN_KERNEL:
+ default: /* fall-through */
+ ret = LTTNG_ERR_UND;
+ goto error;
+ }
+
+ return nb_fields;
+
+error:
+ /* Return negative value to differentiate return code */
+ return -ret;
+}
+
+ssize_t cmd_list_syscalls(struct lttng_event **events)
+{
+ return syscall_table_list(events);
+}
+
+/*
+ * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
+ *
+ * Called with session lock held.
+ */
+ssize_t cmd_list_tracker_pids(struct ltt_session *session,
+ enum lttng_domain_type domain, int32_t **pids)
+{
+ int ret;
+ ssize_t nr_pids = 0;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ {
+ struct ltt_kernel_session *ksess;
+
+ ksess = session->kernel_session;
+ nr_pids = kernel_list_tracker_pids(ksess, pids);
+ if (nr_pids < 0) {
+ ret = LTTNG_ERR_KERN_LIST_FAIL;
+ goto error;
+ }
+ break;
+ }
+ case LTTNG_DOMAIN_UST:
+ {
+ struct ltt_ust_session *usess;
+
+ usess = session->ust_session;
+ nr_pids = trace_ust_list_tracker_pids(usess, pids);
+ if (nr_pids < 0) {
+ ret = LTTNG_ERR_UST_LIST_FAIL;
+ goto error;
+ }
+ break;
+ }
+ case LTTNG_DOMAIN_LOG4J:
+ case LTTNG_DOMAIN_JUL:
+ case LTTNG_DOMAIN_PYTHON:
+ default:
+ ret = LTTNG_ERR_UND;
+ goto error;
+ }
+
+ return nr_pids;
+
+error:
+ /* Return negative value to differentiate return code */
+ return -ret;
+}
+
+/*
+ * Command LTTNG_START_TRACE processed by the client thread.
+ *
+ * Called with session mutex held.
+ */
+int cmd_start_trace(struct ltt_session *session)
+{
+ int ret;
+ unsigned long nb_chan = 0;
+ struct ltt_kernel_session *ksession;
+ struct ltt_ust_session *usess;
+
+ assert(session);
+
+ /* Ease our life a bit ;) */
+ ksession = session->kernel_session;
+ usess = session->ust_session;
+
+ /* Is the session already started? */
+ if (session->active) {
+ ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
+ goto error;
+ }
+
+ /*
+ * Starting a session without channel is useless since after that it's not
+ * possible to enable channel thus inform the client.
+ */
+ if (usess && usess->domain_global.channels) {
+ nb_chan += lttng_ht_get_count(usess->domain_global.channels);
+ }
+ if (ksession) {
+ nb_chan += ksession->channel_count;
+ }
+ if (!nb_chan) {
+ ret = LTTNG_ERR_NO_CHANNEL;
+ goto error;
+ }
+
+ /* Kernel tracing */
+ if (ksession != NULL) {
+ ret = start_kernel_session(ksession, kernel_tracer_fd);
+ if (ret != LTTNG_OK) {
+ goto error;
+ }
+ }
+
+ /* Flag session that trace should start automatically */
+ if (usess) {
+ /*
+ * Even though the start trace might fail, flag this session active so
+ * other application coming in are started by default.
+ */
+ usess->active = 1;
+
+ ret = ust_app_start_trace_all(usess);
+ if (ret < 0) {
+ ret = LTTNG_ERR_UST_START_FAIL;
+ goto error;
+ }
+ }
+
+ /* Flag this after a successful start. */
+ session->has_been_started = 1;
+ session->active = 1;
+
+ ret = LTTNG_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_STOP_TRACE processed by the client thread.
+ */
+int cmd_stop_trace(struct ltt_session *session)
+{
+ int ret;
+ struct ltt_kernel_channel *kchan;
+ struct ltt_kernel_session *ksession;
+ struct ltt_ust_session *usess;
+
+ assert(session);
+
+ /* Short cut */
+ ksession = session->kernel_session;
+ usess = session->ust_session;
+
+ /* Session is not active. Skip everythong and inform the client. */
+ if (!session->active) {
+ ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
+ goto error;
+ }
+
+ /* Kernel tracer */
+ if (ksession && ksession->active) {
+ DBG("Stop kernel tracing");
+
+ /* Flush metadata if exist */
+ if (ksession->metadata_stream_fd >= 0) {
+ ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
+ if (ret < 0) {
+ ERR("Kernel metadata flush failed");
+ }
+ }
+
+ /* Flush all buffers before stopping */
+ cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
+ ret = kernel_flush_buffer(kchan);
+ if (ret < 0) {
+ ERR("Kernel flush buffer error");
+ }
+ }
+
+ ret = kernel_stop_session(ksession);
+ if (ret < 0) {
+ ret = LTTNG_ERR_KERN_STOP_FAIL;
+ goto error;
+ }
+
+ kernel_wait_quiescent(kernel_tracer_fd);
+
+ ksession->active = 0;
+ }
+
+ if (usess && usess->active) {
+ /*
+ * Even though the stop trace might fail, flag this session inactive so
+ * other application coming in are not started by default.
+ */
+ usess->active = 0;
+
+ ret = ust_app_stop_trace_all(usess);
+ if (ret < 0) {
+ ret = LTTNG_ERR_UST_STOP_FAIL;
+ goto error;
+ }
+ }
+
+ /* Flag inactive after a successful stop. */
+ session->active = 0;
+ ret = LTTNG_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
+ */
+int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
+ struct lttng_uri *uris)
+{
+ int ret, i;
+ struct ltt_kernel_session *ksess = session->kernel_session;
+ struct ltt_ust_session *usess = session->ust_session;
+
+ assert(session);
+ assert(uris);
+ assert(nb_uri > 0);
+
+ /* Can't set consumer URI if the session is active. */
+ if (session->active) {
+ ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
+ goto error;
+ }
+
+ /* Set the "global" consumer URIs */
+ for (i = 0; i < nb_uri; i++) {
+ ret = add_uri_to_consumer(session->consumer,
+ &uris[i], 0, session->name);
+ if (ret != LTTNG_OK) {
+ goto error;
+ }
+ }
+
+ /* Set UST session URIs */
+ if (session->ust_session) {
+ for (i = 0; i < nb_uri; i++) {
+ ret = add_uri_to_consumer(
+ session->ust_session->consumer,
+ &uris[i], LTTNG_DOMAIN_UST,
+ session->name);
+ if (ret != LTTNG_OK) {
+ goto error;
+ }
+ }
+ }
+
+ /* Set kernel session URIs */
+ if (session->kernel_session) {
+ for (i = 0; i < nb_uri; i++) {
+ ret = add_uri_to_consumer(
+ session->kernel_session->consumer,
+ &uris[i], LTTNG_DOMAIN_KERNEL,
+ session->name);
+ if (ret != LTTNG_OK) {
+ goto error;
+ }
+ }
+ }
+
+ /*
+ * Make sure to set the session in output mode after we set URI since a
+ * session can be created without URL (thus flagged in no output mode).
+ */
+ session->output_traces = 1;
+ if (ksess) {
+ ksess->output_traces = 1;
+ }
+
+ if (usess) {
+ usess->output_traces = 1;
+ }
+
+ /* All good! */
+ ret = LTTNG_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_CREATE_SESSION processed by the client thread.
+ */
+int cmd_create_session_uri(char *name, struct lttng_uri *uris,
+ size_t nb_uri, lttng_sock_cred *creds, unsigned int live_timer)
+{
+ int ret;
+ struct ltt_session *session;
+
+ assert(name);
+ assert(creds);
+
+ /*
+ * Verify if the session already exist
+ *
+ * XXX: There is no need for the session lock list here since the caller
+ * (process_client_msg) is holding it. We might want to change that so a
+ * single command does not lock the entire session list.
+ */
+ session = session_find_by_name(name);
+ if (session != NULL) {
+ ret = LTTNG_ERR_EXIST_SESS;
+ goto find_error;
+ }
+
+ /* Create tracing session in the registry */
+ ret = session_create(name, LTTNG_SOCK_GET_UID_CRED(creds),
+ LTTNG_SOCK_GET_GID_CRED(creds));
+ if (ret != LTTNG_OK) {
+ goto session_error;
+ }
+
+ /*
+ * Get the newly created session pointer back
+ *
+ * XXX: There is no need for the session lock list here since the caller
+ * (process_client_msg) is holding it. We might want to change that so a
+ * single command does not lock the entire session list.
+ */
+ session = session_find_by_name(name);
+ assert(session);
+
+ session->live_timer = live_timer;
+ /* Create default consumer output for the session not yet created. */
+ session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
+ if (session->consumer == NULL) {
+ ret = LTTNG_ERR_FATAL;
+ goto consumer_error;
+ }
+
+ if (uris) {
+ ret = cmd_set_consumer_uri(session, nb_uri, uris);
+ if (ret != LTTNG_OK) {
+ goto consumer_error;
+ }
+ session->output_traces = 1;
+ } else {
+ session->output_traces = 0;
+ DBG2("Session %s created with no output", session->name);
+ }
+
+ session->consumer->enabled = 1;
+
+ return LTTNG_OK;
+
+consumer_error:
+ session_destroy(session);
+session_error:
+find_error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_CREATE_SESSION_SNAPSHOT processed by the client thread.
+ */
+int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
+ size_t nb_uri, lttng_sock_cred *creds)
+{
+ int ret;
+ struct ltt_session *session;
+ struct snapshot_output *new_output = NULL;
+
+ assert(name);
+ assert(creds);
+
+ /*
+ * Create session in no output mode with URIs set to NULL. The uris we've
+ * received are for a default snapshot output if one.
+ */
+ ret = cmd_create_session_uri(name, NULL, 0, creds, 0);
+ if (ret != LTTNG_OK) {
+ goto error;
+ }
+
+ /* Get the newly created session pointer back. This should NEVER fail. */
+ session = session_find_by_name(name);
+ assert(session);
+
+ /* Flag session for snapshot mode. */
+ session->snapshot_mode = 1;
+
+ /* Skip snapshot output creation if no URI is given. */
+ if (nb_uri == 0) {
+ goto end;
+ }
+
+ new_output = snapshot_output_alloc();
+ if (!new_output) {
+ ret = LTTNG_ERR_NOMEM;
+ goto error_snapshot_alloc;
+ }
+
+ ret = snapshot_output_init_with_uri(DEFAULT_SNAPSHOT_MAX_SIZE, NULL,
+ uris, nb_uri, session->consumer, new_output, &session->snapshot);
+ if (ret < 0) {
+ if (ret == -ENOMEM) {
+ ret = LTTNG_ERR_NOMEM;
+ } else {
+ ret = LTTNG_ERR_INVALID;
+ }
+ goto error_snapshot;
+ }
+
+ rcu_read_lock();
+ snapshot_add_output(&session->snapshot, new_output);
+ rcu_read_unlock();
+
+end:
+ return LTTNG_OK;
+
+error_snapshot:
+ snapshot_output_destroy(new_output);
+error_snapshot_alloc:
+ session_destroy(session);
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_DESTROY_SESSION processed by the client thread.
+ *
+ * Called with session lock held.
+ */
+int cmd_destroy_session(struct ltt_session *session, int wpipe)
+{
+ int ret;
+ struct ltt_ust_session *usess;
+ struct ltt_kernel_session *ksess;
+
+ /* Safety net */
+ assert(session);
+
+ usess = session->ust_session;
+ ksess = session->kernel_session;
+
+ /* Clean kernel session teardown */
+ kernel_destroy_session(ksess);
+
+ /* UST session teardown */
+ if (usess) {
+ /* Close any relayd session */
+ consumer_output_send_destroy_relayd(usess->consumer);
+
+ /* Destroy every UST application related to this session. */
+ ret = ust_app_destroy_trace_all(usess);
+ if (ret) {
+ ERR("Error in ust_app_destroy_trace_all");
+ }
+
+ /* Clean up the rest. */
+ trace_ust_destroy_session(usess);
+ }
+
+ /*
+ * Must notify the kernel thread here to update it's poll set in order to
+ * remove the channel(s)' fd just destroyed.
+ */
+ ret = notify_thread_pipe(wpipe);
+ if (ret < 0) {
+ PERROR("write kernel poll pipe");
+ }
+
+ ret = session_destroy(session);
+
+ return ret;
+}
+
+/*
+ * Command LTTNG_CALIBRATE processed by the client thread.
+ */
+int cmd_calibrate(enum lttng_domain_type domain,
+ struct lttng_calibrate *calibrate)
+{
+ int ret;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ {
+ struct lttng_kernel_calibrate kcalibrate;
+
+ switch (calibrate->type) {
+ case LTTNG_CALIBRATE_FUNCTION:
+ default:
+ /* Default and only possible calibrate option. */
+ kcalibrate.type = LTTNG_KERNEL_CALIBRATE_KRETPROBE;
+ break;
+ }
+
+ ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
+ if (ret < 0) {
+ ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ goto error;
+ }
+ break;
+ }
+ case LTTNG_DOMAIN_UST:
+ {
+ struct lttng_ust_calibrate ucalibrate;
+
+ switch (calibrate->type) {
+ case LTTNG_CALIBRATE_FUNCTION:
+ default:
+ /* Default and only possible calibrate option. */
+ ucalibrate.type = LTTNG_UST_CALIBRATE_TRACEPOINT;
+ break;
+ }
+
+ ret = ust_app_calibrate_glb(&ucalibrate);
+ if (ret < 0) {
+ ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
+ goto error;
+ }
+ break;
+ }
+ default:
+ ret = LTTNG_ERR_UND;
+ goto error;
+ }
+
+ ret = LTTNG_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
+ */
+int cmd_register_consumer(struct ltt_session *session,
+ enum lttng_domain_type domain, const char *sock_path,
+ struct consumer_data *cdata)
+{
+ int ret, sock;
+ struct consumer_socket *socket = NULL;
+
+ assert(session);
+ assert(cdata);
+ assert(sock_path);
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ {
+ struct ltt_kernel_session *ksess = session->kernel_session;
+
+ assert(ksess);
+
+ /* Can't register a consumer if there is already one */
+ if (ksess->consumer_fds_sent != 0) {
+ ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+ goto error;
+ }
+
+ sock = lttcomm_connect_unix_sock(sock_path);
+ if (sock < 0) {
+ ret = LTTNG_ERR_CONNECT_FAIL;
+ goto error;
+ }
+ cdata->cmd_sock = sock;
+
+ socket = consumer_allocate_socket(&cdata->cmd_sock);
+ if (socket == NULL) {
+ ret = close(sock);
+ if (ret < 0) {
+ PERROR("close register consumer");
+ }
+ cdata->cmd_sock = -1;
+ ret = LTTNG_ERR_FATAL;
+ goto error;
+ }
+
+ socket->lock = zmalloc(sizeof(pthread_mutex_t));
+ if (socket->lock == NULL) {
+ PERROR("zmalloc pthread mutex");
+ ret = LTTNG_ERR_FATAL;
+ goto error;
+ }
+ pthread_mutex_init(socket->lock, NULL);
+ socket->registered = 1;
+
+ rcu_read_lock();
+ consumer_add_socket(socket, ksess->consumer);
+ rcu_read_unlock();
+
+ pthread_mutex_lock(&cdata->pid_mutex);
+ cdata->pid = -1;
+ pthread_mutex_unlock(&cdata->pid_mutex);
+
+ break;
+ }
+ default:
+ /* TODO: Userspace tracing */
+ ret = LTTNG_ERR_UND;
+ goto error;
+ }
+
+ return LTTNG_OK;
+
+error:
+ if (socket) {
+ consumer_destroy_socket(socket);
+ }
+ return ret;
+}
+
+/*
+ * Command LTTNG_LIST_DOMAINS processed by the client thread.
+ */
+ssize_t cmd_list_domains(struct ltt_session *session,
+ struct lttng_domain **domains)
+{
+ int ret, index = 0;
+ ssize_t nb_dom = 0;
+ struct agent *agt;
+ struct lttng_ht_iter iter;