+ /* Parse filter expression. */
+ if (filter_expression != NULL || handle->domain.type == LTTNG_DOMAIN_JUL
+ || handle->domain.type == LTTNG_DOMAIN_LOG4J
+ || handle->domain.type == LTTNG_DOMAIN_PYTHON) {
+ if (handle->domain.type == LTTNG_DOMAIN_JUL ||
+ handle->domain.type == LTTNG_DOMAIN_LOG4J ||
+ handle->domain.type == LTTNG_DOMAIN_PYTHON) {
+ char *agent_filter;
+
+ /* Setup agent filter if needed. */
+ agent_filter = set_agent_filter(filter_expression, ev);
+ if (!agent_filter) {
+ if (!filter_expression) {
+ /*
+ * No JUL and no filter, just skip
+ * everything below.
+ */
+ goto serialize;
+ }
+ } else {
+ /*
+ * With an agent filter, the original filter has
+ * been added to it thus replace the filter
+ * expression.
+ */
+ filter_expression = agent_filter;
+ free_filter_expression = 1;
+ }
+ }
+
+ if (strnlen(filter_expression, LTTNG_FILTER_MAX_LEN) ==
+ LTTNG_FILTER_MAX_LEN) {
+ ret = -LTTNG_ERR_FILTER_INVAL;
+ goto error;
+ }
+
+ ret = filter_parser_ctx_create_from_filter_expression(filter_expression, &ctx);
+ if (ret) {
+ goto error;
+ }
+
+ bytecode_len = bytecode_get_len(&ctx->bytecode->b) +
+ sizeof(ctx->bytecode->b);
+ if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
+ ret = -LTTNG_ERR_FILTER_INVAL;
+ goto error;
+ }
+ }
+
+serialize:
+ ret = lttng_event_serialize(ev, exclusion_count, exclusion_list,
+ filter_expression, bytecode_len,
+ (ctx && bytecode_len) ? &ctx->bytecode->b : NULL,
+ &payload);
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* If no channel name, send empty string. */
+ ret = lttng_strncpy(lsm.u.enable.channel_name, channel_name ?: "",
+ sizeof(lsm.u.enable.channel_name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* Domain */
+ COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
+
+ /* Session name */
+ ret = lttng_strncpy(lsm.session.name, handle->session_name,
+ sizeof(lsm.session.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* Length of the serialized event. */
+ lsm.u.enable.length = (uint32_t) payload.buffer.size;
+
+ {
+ struct lttng_payload_view view = lttng_payload_view_from_payload(
+ &payload, 0, -1);
+ int fd_count = lttng_payload_view_get_fd_handle_count(&view);
+ int fd_to_send;
+
+ if (fd_count < 0) {
+ goto error;
+ }
+
+ assert(fd_count == 0 || fd_count == 1);
+ if (fd_count == 1) {
+ struct fd_handle *h =
+ lttng_payload_view_pop_fd_handle(&view);
+
+ if (!h) {
+ goto error;
+ }
+
+ fd_to_send = fd_handle_get_fd(h);
+ fd_handle_put(h);
+ }
+
+ lsm.fd_count = fd_count;
+
+ ret = lttng_ctl_ask_sessiond_fds_varlen(&lsm,
+ fd_count ? &fd_to_send : NULL, fd_count,
+ view.buffer.size ? view.buffer.data : NULL,
+ view.buffer.size, NULL, NULL, 0);
+ }
+
+error:
+ if (filter_expression && ctx) {
+ filter_bytecode_free(ctx);
+ filter_ir_free(ctx);
+ filter_parser_ctx_free(ctx);
+ }
+ if (free_filter_expression) {
+ /*
+ * The filter expression has been replaced and must be freed as
+ * it is not the original filter expression received as a
+ * parameter.
+ */
+ free(filter_expression);
+ }
+ /*
+ * Return directly to the caller and don't ask the sessiond since
+ * something went wrong in the parsing of data above.
+ */
+ lttng_payload_reset(&payload);
+ return ret;
+}
+
+int lttng_disable_event_ext(struct lttng_handle *handle,
+ struct lttng_event *ev, const char *channel_name,
+ const char *original_filter_expression)
+{
+ struct lttcomm_session_msg lsm = { .cmd_type = LTTNG_DISABLE_EVENT };
+ struct lttng_payload payload;
+ int ret = 0;
+ unsigned int free_filter_expression = 0;
+ struct filter_parser_ctx *ctx = NULL;
+ size_t bytecode_len = 0;
+
+ /*
+ * We have either a filter or some exclusions, so we need to set up
+ * a variable-length payload from where to send the data.
+ */
+ lttng_payload_init(&payload);
+
+ /*
+ * Cast as non-const since we may replace the filter expression
+ * by a dynamically allocated string. Otherwise, the original
+ * string is not modified.
+ */
+ char *filter_expression = (char *) original_filter_expression;
+
+ if (handle == NULL || ev == NULL) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /*
+ * Empty filter string will always be rejected by the parser
+ * anyway, so treat this corner-case early to eliminate
+ * lttng_fmemopen error for 0-byte allocation.
+ */
+ if (filter_expression && filter_expression[0] == '\0') {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* Parse filter expression. */
+ if (filter_expression != NULL || handle->domain.type == LTTNG_DOMAIN_JUL
+ || handle->domain.type == LTTNG_DOMAIN_LOG4J
+ || handle->domain.type == LTTNG_DOMAIN_PYTHON) {
+ if (handle->domain.type == LTTNG_DOMAIN_JUL ||
+ handle->domain.type == LTTNG_DOMAIN_LOG4J ||
+ handle->domain.type == LTTNG_DOMAIN_PYTHON) {
+ char *agent_filter;
+
+ /* Setup agent filter if needed. */
+ agent_filter = set_agent_filter(filter_expression, ev);
+ if (!agent_filter) {
+ if (!filter_expression) {
+ /*
+ * No JUL and no filter, just skip
+ * everything below.
+ */
+ goto serialize;
+ }
+ } else {
+ /*
+ * With an agent filter, the original filter has
+ * been added to it thus replace the filter
+ * expression.
+ */
+ filter_expression = agent_filter;
+ free_filter_expression = 1;
+ }
+ }
+
+ if (strnlen(filter_expression, LTTNG_FILTER_MAX_LEN) ==
+ LTTNG_FILTER_MAX_LEN) {
+ ret = -LTTNG_ERR_FILTER_INVAL;
+ goto error;
+ }
+
+ ret = filter_parser_ctx_create_from_filter_expression(filter_expression, &ctx);
+ if (ret) {
+ goto error;
+ }
+
+ bytecode_len = bytecode_get_len(&ctx->bytecode->b) +
+ sizeof(ctx->bytecode->b);
+ if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
+ ret = -LTTNG_ERR_FILTER_INVAL;
+ goto error;
+ }
+ }
+
+serialize:
+ ret = lttng_event_serialize(ev, 0, NULL,
+ filter_expression, bytecode_len,
+ (ctx && bytecode_len) ? &ctx->bytecode->b : NULL,
+ &payload);
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* If no channel name, send empty string. */
+ ret = lttng_strncpy(lsm.u.disable.channel_name, channel_name ?: "",
+ sizeof(lsm.u.disable.channel_name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* Domain */
+ COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
+
+ /* Session name */
+ ret = lttng_strncpy(lsm.session.name, handle->session_name,
+ sizeof(lsm.session.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* Length of the serialized event. */
+ lsm.u.disable.length = (uint32_t) payload.buffer.size;
+
+ {
+ struct lttng_payload_view view = lttng_payload_view_from_payload(
+ &payload, 0, -1);
+ int fd_count = lttng_payload_view_get_fd_handle_count(&view);
+ int fd_to_send;
+
+ if (fd_count < 0) {
+ goto error;
+ }
+
+ assert(fd_count == 0 || fd_count == 1);
+ if (fd_count == 1) {
+ struct fd_handle *h =
+ lttng_payload_view_pop_fd_handle(&view);
+
+ if (!h) {
+ goto error;
+ }
+
+ fd_to_send = fd_handle_get_fd(h);
+ fd_handle_put(h);
+ }
+
+ ret = lttng_ctl_ask_sessiond_fds_varlen(&lsm,
+ fd_count ? &fd_to_send : NULL, fd_count,
+ view.buffer.size ? view.buffer.data : NULL,
+ view.buffer.size, NULL, NULL, 0);
+ }
+
+error:
+ if (filter_expression && ctx) {
+ filter_bytecode_free(ctx);
+ filter_ir_free(ctx);
+ filter_parser_ctx_free(ctx);
+ }
+ if (free_filter_expression) {
+ /*
+ * The filter expression has been replaced and must be freed as
+ * it is not the original filter expression received as a
+ * parameter.
+ */
+ free(filter_expression);
+ }
+ /*
+ * Return directly to the caller and don't ask the sessiond since
+ * something went wrong in the parsing of data above.
+ */
+ lttng_payload_reset(&payload);
+ return ret;
+}
+
+/*
+ * Disable event(s) of a channel and domain.
+ * If no event name is specified, all events are disabled.
+ * If no channel name is specified, the default 'channel0' is used.
+ * Returns size of returned session payload data or a negative error code.
+ */
+int lttng_disable_event(struct lttng_handle *handle, const char *name,
+ const char *channel_name)
+{
+ int ret;
+ struct lttng_event ev;
+
+ memset(&ev, 0, sizeof(ev));
+ ev.loglevel = -1;
+ ev.type = LTTNG_EVENT_ALL;
+ ret = lttng_strncpy(ev.name, name ?: "", sizeof(ev.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ret = lttng_disable_event_ext(handle, &ev, channel_name, NULL);
+end:
+ return ret;
+}
+
+struct lttng_channel *lttng_channel_create(struct lttng_domain *domain)
+{
+ struct lttng_channel *channel = NULL;
+
+ if (!domain) {
+ goto end;
+ }
+
+ /* Validate domain. */
+ switch (domain->type) {
+ case LTTNG_DOMAIN_UST:
+ switch (domain->buf_type) {
+ case LTTNG_BUFFER_PER_UID:
+ case LTTNG_BUFFER_PER_PID:
+ break;
+ default:
+ goto end;
+ }
+ break;
+ case LTTNG_DOMAIN_KERNEL:
+ if (domain->buf_type != LTTNG_BUFFER_GLOBAL) {
+ goto end;
+ }
+ break;
+ default:
+ goto end;
+ }
+
+ channel = lttng_channel_create_internal();
+ if (!channel) {
+ goto end;
+ }
+
+ lttng_channel_set_default_attr(domain, &channel->attr);
+end:
+ return channel;
+}
+
+void lttng_channel_destroy(struct lttng_channel *channel)
+{
+ if (!channel) {
+ return;
+ }
+
+ if (channel->attr.extended.ptr) {
+ free(channel->attr.extended.ptr);
+ }
+ free(channel);
+}
+
+/*
+ * Enable channel per domain
+ * Returns size of returned session payload data or a negative error code.
+ */
+int lttng_enable_channel(struct lttng_handle *handle,
+ struct lttng_channel *in_chan)
+{
+ enum lttng_error_code ret_code;
+ int ret;
+ struct lttng_dynamic_buffer buffer;
+ struct lttcomm_session_msg lsm;
+ uint64_t total_buffer_size_needed_per_cpu = 0;
+ struct lttng_channel *channel = NULL;
+
+ lttng_dynamic_buffer_init(&buffer);
+
+ /* NULL arguments are forbidden. No default values. */
+ if (handle == NULL || in_chan == NULL) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ /*
+ * Verify that the amount of memory required to create the requested
+ * buffer is available on the system at the moment.
+ */
+ if (in_chan->attr.num_subbuf >
+ UINT64_MAX / in_chan->attr.subbuf_size) {
+ /* Overflow */
+ ret = -LTTNG_ERR_OVERFLOW;
+ goto end;
+ }
+
+ total_buffer_size_needed_per_cpu =
+ in_chan->attr.num_subbuf * in_chan->attr.subbuf_size;
+ ret_code = check_enough_available_memory(
+ total_buffer_size_needed_per_cpu);
+ if (ret_code != LTTNG_OK) {
+ ret = -ret_code;
+ goto end;
+ }
+
+ /* Copy the channel for easier manipulation. */
+ channel = lttng_channel_copy(in_chan);
+ if (!channel) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* Populate the channel extended attribute if necessary. */
+ if (!channel->attr.extended.ptr) {
+ struct lttng_channel_extended *extended =
+ (struct lttng_channel_extended *) zmalloc(
+ sizeof(*extended));
+
+ if (!extended) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ lttng_channel_set_default_extended_attr(
+ &handle->domain, extended);
+ channel->attr.extended.ptr = extended;
+ }
+
+ /* Prepare the payload */
+ memset(&lsm, 0, sizeof(lsm));
+
+ lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
+ COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
+
+ ret = lttng_strncpy(lsm.session.name, handle->session_name,
+ sizeof(lsm.session.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ret = lttng_channel_serialize(channel, &buffer);
+ if (ret) {
+ ret = -LTTNG_ERR_FATAL;
+ goto end;
+ }
+
+ lsm.u.channel.length = buffer.size;
+
+ ret = lttng_ctl_ask_sessiond_varlen_no_cmd_header(
+ &lsm, buffer.data, buffer.size, NULL);
+end:
+ lttng_channel_destroy(channel);
+ lttng_dynamic_buffer_reset(&buffer);
+ return ret;
+}
+
+/*
+ * All tracing will be stopped for registered events of the channel.
+ * Returns size of returned session payload data or a negative error code.
+ */
+int lttng_disable_channel(struct lttng_handle *handle, const char *name)
+{
+ int ret;
+ struct lttcomm_session_msg lsm;
+
+ /* Safety check. Both are mandatory. */
+ if (handle == NULL || name == NULL) {
+ return -LTTNG_ERR_INVALID;
+ }
+
+ memset(&lsm, 0, sizeof(lsm));
+
+ lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
+
+ ret = lttng_strncpy(lsm.u.disable.channel_name, name,
+ sizeof(lsm.u.disable.channel_name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
+
+ ret = lttng_strncpy(lsm.session.name, handle->session_name,
+ sizeof(lsm.session.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ret = lttng_ctl_ask_sessiond(&lsm, NULL);
+end:
+ return ret;
+}
+
+/*
+ * Lists all available tracepoints of domain.
+ * Sets the contents of the events array.
+ * Returns the number of lttng_event entries in events;
+ * on error, returns a negative value.
+ */
+int lttng_list_tracepoints(struct lttng_handle *handle,
+ struct lttng_event **events)
+{
+ enum lttng_error_code ret_code;
+ int ret, total_payload_received;
+ char *reception_buffer = NULL;
+ struct lttcomm_session_msg lsm = { .cmd_type = LTTNG_LIST_TRACEPOINTS };
+ struct lttcomm_list_command_header *cmd_header = NULL;
+ size_t cmd_header_len;
+ unsigned int nb_events = 0;
+
+ if (handle == NULL) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
+
+ ret = lttng_ctl_ask_sessiond_fds_varlen(&lsm, NULL, 0, NULL, 0,
+ (void **) &reception_buffer, (void **) &cmd_header,
+ &cmd_header_len);
+ if (ret < 0) {
+ goto end;
+ }
+
+ total_payload_received = ret;
+
+ if (!cmd_header) {
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+
+ if (cmd_header->count > INT_MAX) {
+ ret = -LTTNG_ERR_OVERFLOW;
+ goto end;
+ }
+
+ nb_events = (unsigned int) cmd_header->count;
+
+ {
+ struct lttng_buffer_view events_view =
+ lttng_buffer_view_init(reception_buffer, 0,
+ total_payload_received);
+ struct lttng_payload_view events_payload_view =
+ lttng_payload_view_from_buffer_view(
+ &events_view, 0, -1);
+
+ ret_code = lttng_events_create_and_flatten_from_payload(
+ &events_payload_view, nb_events, events);
+ if (ret_code != LTTNG_OK) {
+ ret = -ret_code;
+ goto end;
+ }
+ }
+
+ ret = (int) nb_events;
+
+end:
+ free(cmd_header);
+ free(reception_buffer);
+ return ret;
+}
+
+/*
+ * Lists all available tracepoint fields of domain.
+ * Sets the contents of the event field array.
+ * Returns the number of lttng_event_field entries in events;
+ * on error, returns a negative value.
+ */
+int lttng_list_tracepoint_fields(struct lttng_handle *handle,
+ struct lttng_event_field **fields)
+{
+ enum lttng_error_code ret_code;
+ int ret;
+ struct lttcomm_session_msg lsm;
+ const struct lttcomm_list_command_header *cmd_header = NULL;
+ unsigned int nb_event_fields = 0;
+ struct lttng_payload reply;
+
+ if (handle == NULL) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ lttng_payload_init(&reply);
+
+ memset(&lsm, 0, sizeof(lsm));
+ lsm.cmd_type = LTTNG_LIST_TRACEPOINT_FIELDS;
+ COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
+
+ {
+ struct lttng_payload_view message_view =
+ lttng_payload_view_init_from_buffer(
+ (const char *) &lsm, 0,
+ sizeof(lsm));
+
+ ret = lttng_ctl_ask_sessiond_payload(&message_view, &reply);
+ if (ret < 0) {
+ goto end;
+ }
+ }
+
+ {
+ const struct lttng_buffer_view cmd_header_view =
+ lttng_buffer_view_from_dynamic_buffer(
+ &reply.buffer, 0, sizeof(*cmd_header));
+
+ if (!lttng_buffer_view_is_valid(&cmd_header_view)) {
+ ret = -LTTNG_ERR_INVALID_PROTOCOL;
+ goto end;
+ }
+
+ cmd_header = (struct lttcomm_list_command_header *)
+ cmd_header_view.data;
+ }
+
+ if (cmd_header->count > INT_MAX) {
+ ret = -LTTNG_ERR_OVERFLOW;
+ goto end;
+ }
+
+ nb_event_fields = cmd_header->count;
+
+ {
+ struct lttng_payload_view reply_view =
+ lttng_payload_view_from_payload(&reply,
+ sizeof(*cmd_header), -1);
+
+ ret_code = lttng_event_fields_create_and_flatten_from_payload(
+ &reply_view, nb_event_fields, fields);
+ if (ret_code != LTTNG_OK) {
+ ret = -ret_code;
+ goto end;
+ }
+ }
+
+ ret = nb_event_fields;
+
+end:
+ return ret;
+}
+
+/*
+ * Lists all available kernel system calls. Allocates and sets the contents of
+ * the events array.
+ *
+ * Returns the number of lttng_event entries in events; on error, returns a
+ * negative value.
+ */
+int lttng_list_syscalls(struct lttng_event **events)
+{
+ enum lttng_error_code ret_code;
+ int ret, total_payload_received;
+ char *reception_buffer = NULL;
+ struct lttcomm_session_msg lsm = {};
+ struct lttcomm_list_command_header *cmd_header = NULL;
+ size_t cmd_header_len;
+ uint32_t nb_events = 0;
+
+ if (!events) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ lsm.cmd_type = LTTNG_LIST_SYSCALLS;
+ /* Force kernel domain for system calls. */
+ lsm.domain.type = LTTNG_DOMAIN_KERNEL;
+
+ ret = lttng_ctl_ask_sessiond_fds_varlen(&lsm, NULL, 0, NULL, 0,
+ (void **) &reception_buffer, (void **) &cmd_header,
+ &cmd_header_len);
+ if (ret < 0) {
+ goto end;
+ }
+ total_payload_received = ret;
+
+ if (!cmd_header) {
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+
+ if (cmd_header->count > INT_MAX) {
+ ret = -LTTNG_ERR_OVERFLOW;
+ goto end;
+ }
+
+ nb_events = (unsigned int) cmd_header->count;
+
+ {
+ const struct lttng_buffer_view events_view =
+ lttng_buffer_view_init(reception_buffer, 0,
+ total_payload_received);
+ struct lttng_payload_view events_payload_view =
+ lttng_payload_view_from_buffer_view(
+ &events_view, 0, -1);
+
+ ret_code = lttng_events_create_and_flatten_from_payload(
+ &events_payload_view, nb_events, events);
+ if (ret_code != LTTNG_OK) {
+ ret = -ret_code;
+ goto end;
+ }
+ }
+
+ ret = (int) nb_events;
+
+end:
+ free(reception_buffer);
+ free(cmd_header);
+ return ret;
+}
+
+/*
+ * Returns a human readable string describing
+ * the error code (a negative value).
+ */
+const char *lttng_strerror(int code)
+{
+ return error_get_str(code);
+}
+
+enum lttng_error_code lttng_create_session_ext(
+ struct lttng_session_descriptor *session_descriptor)
+{
+ enum lttng_error_code ret_code;
+ struct lttcomm_session_msg lsm = {
+ .cmd_type = LTTNG_CREATE_SESSION_EXT,
+ };
+ void *reply = NULL;
+ struct lttng_buffer_view reply_view;
+ int reply_ret;
+ bool sessiond_must_generate_ouput;
+ struct lttng_dynamic_buffer payload;
+ int ret;
+ size_t descriptor_size;
+ struct lttng_session_descriptor *descriptor_reply = NULL;
+
+ lttng_dynamic_buffer_init(&payload);
+ if (!session_descriptor) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ sessiond_must_generate_ouput =
+ !lttng_session_descriptor_is_output_destination_initialized(
+ session_descriptor);
+ if (sessiond_must_generate_ouput) {
+ const char *home_dir = utils_get_home_dir();
+ size_t home_dir_len = home_dir ? strlen(home_dir) + 1 : 0;
+
+ if (!home_dir || home_dir_len > LTTNG_PATH_MAX) {
+ ret_code = LTTNG_ERR_FATAL;
+ goto end;
+ }
+
+ lsm.u.create_session.home_dir_size = (uint16_t) home_dir_len;
+ ret = lttng_dynamic_buffer_append(&payload, home_dir,
+ home_dir_len);
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+
+ descriptor_size = payload.size;
+ ret = lttng_session_descriptor_serialize(session_descriptor,
+ &payload);
+ if (ret) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+ descriptor_size = payload.size - descriptor_size;
+ lsm.u.create_session.session_descriptor_size = descriptor_size;
+
+ /* Command returns a session descriptor on success. */
+ reply_ret = lttng_ctl_ask_sessiond_varlen_no_cmd_header(&lsm, payload.data,
+ payload.size, &reply);
+ if (reply_ret < 0) {
+ ret_code = -reply_ret;
+ goto end;
+ } else if (reply_ret == 0) {
+ /* Socket unexpectedly closed by the session daemon. */
+ ret_code = LTTNG_ERR_FATAL;
+ goto end;
+ }
+
+ reply_view = lttng_buffer_view_init(reply, 0, reply_ret);
+ ret = lttng_session_descriptor_create_from_buffer(&reply_view,
+ &descriptor_reply);
+ if (ret < 0) {
+ ret_code = LTTNG_ERR_FATAL;
+ goto end;
+ }
+ ret_code = LTTNG_OK;
+ lttng_session_descriptor_assign(session_descriptor, descriptor_reply);
+end:
+ free(reply);
+ lttng_dynamic_buffer_reset(&payload);
+ lttng_session_descriptor_destroy(descriptor_reply);
+ return ret_code;
+}
+
+/*
+ * Create a new session using name and url for destination.
+ *
+ * Return 0 on success else a negative LTTng error code.
+ */
+int lttng_create_session(const char *name, const char *url)
+{
+ int ret;
+ ssize_t size;
+ struct lttng_uri *uris = NULL;
+ struct lttng_session_descriptor *descriptor = NULL;
+ enum lttng_error_code ret_code;
+
+ if (!name) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ size = uri_parse_str_urls(url, NULL, &uris);
+ if (size < 0) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ switch (size) {
+ case 0:
+ descriptor = lttng_session_descriptor_create(name);
+ break;
+ case 1:
+ if (uris[0].dtype != LTTNG_DST_PATH) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ descriptor = lttng_session_descriptor_local_create(name,
+ uris[0].dst.path);
+ break;
+ case 2:
+ descriptor = lttng_session_descriptor_network_create(name, url,
+ NULL);
+ break;
+ default:
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ if (!descriptor) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ ret_code = lttng_create_session_ext(descriptor);
+ ret = ret_code == LTTNG_OK ? 0 : -ret_code;
+end:
+ lttng_session_descriptor_destroy(descriptor);
+ free(uris);
+ return ret;
+}
+
+/*
+ * Create a session exclusively used for snapshot.
+ *
+ * Return 0 on success else a negative LTTng error code.
+ */
+int lttng_create_session_snapshot(const char *name, const char *snapshot_url)
+{
+ int ret;
+ enum lttng_error_code ret_code;
+ ssize_t size;
+ struct lttng_uri *uris = NULL;
+ struct lttng_session_descriptor *descriptor = NULL;
+
+ if (!name) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ size = uri_parse_str_urls(snapshot_url, NULL, &uris);
+ if (size < 0) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ /*
+ * If the user does not specify a custom subdir, use the session name.
+ */
+ if (size > 0 && uris[0].dtype != LTTNG_DST_PATH &&
+ strlen(uris[0].subdir) == 0) {
+ ret = snprintf(uris[0].subdir, sizeof(uris[0].subdir), "%s",
+ name);
+ if (ret < 0) {
+ PERROR("Failed to set session name as network destination sub-directory");
+ ret = -LTTNG_ERR_FATAL;
+ goto end;
+ } else if (ret >= sizeof(uris[0].subdir)) {
+ /* Truncated output. */
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ }
+
+ switch (size) {
+ case 0:
+ descriptor = lttng_session_descriptor_snapshot_create(name);
+ break;
+ case 1:
+ if (uris[0].dtype != LTTNG_DST_PATH) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ descriptor = lttng_session_descriptor_snapshot_local_create(
+ name,
+ uris[0].dst.path);
+ break;
+ case 2:
+ descriptor = lttng_session_descriptor_snapshot_network_create(
+ name,
+ snapshot_url,
+ NULL);
+ break;
+ default:
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ if (!descriptor) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ ret_code = lttng_create_session_ext(descriptor);
+ ret = ret_code == LTTNG_OK ? 0 : -ret_code;
+end:
+ lttng_session_descriptor_destroy(descriptor);
+ free(uris);
+ return ret;
+}
+
+/*
+ * Create a session exclusively used for live.
+ *
+ * Return 0 on success else a negative LTTng error code.
+ */
+int lttng_create_session_live(const char *name, const char *url,
+ unsigned int timer_interval)
+{
+ int ret;
+ enum lttng_error_code ret_code;
+ struct lttng_session_descriptor *descriptor = NULL;
+
+ if (!name) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ if (url) {
+ descriptor = lttng_session_descriptor_live_network_create(
+ name, url, NULL, timer_interval);
+ } else {
+ descriptor = lttng_session_descriptor_live_create(
+ name, timer_interval);
+ }
+ if (!descriptor) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+ ret_code = lttng_create_session_ext(descriptor);
+ ret = ret_code == LTTNG_OK ? 0 : -ret_code;
+end:
+ lttng_session_descriptor_destroy(descriptor);
+ return ret;
+}
+
+/*
+ * Stop the session and wait for the data before destroying it
+ *
+ * Return 0 on success else a negative LTTng error code.
+ */
+int lttng_destroy_session(const char *session_name)
+{
+ int ret;
+ enum lttng_error_code ret_code;
+ enum lttng_destruction_handle_status status;
+ struct lttng_destruction_handle *handle = NULL;
+
+ /*
+ * Stop the tracing and wait for the data to be
+ * consumed.
+ */
+ ret = _lttng_stop_tracing(session_name, 1);
+ if (ret && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) {
+ goto end;
+ }
+
+ ret_code = lttng_destroy_session_ext(session_name, &handle);
+ if (ret_code != LTTNG_OK) {
+ ret = (int) -ret_code;
+ goto end;
+ }
+ assert(handle);
+
+ /* Block until the completion of the destruction of the session. */
+ status = lttng_destruction_handle_wait_for_completion(handle, -1);
+ if (status != LTTNG_DESTRUCTION_HANDLE_STATUS_COMPLETED) {
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+
+ status = lttng_destruction_handle_get_result(handle, &ret_code);
+ if (status != LTTNG_DESTRUCTION_HANDLE_STATUS_OK) {
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ ret = ret_code == LTTNG_OK ? 0 : -ret_code;
+end:
+ lttng_destruction_handle_destroy(handle);
+ return ret;
+}
+
+/*
+ * Destroy the session without waiting for the data.
+ */
+int lttng_destroy_session_no_wait(const char *session_name)
+{
+ enum lttng_error_code ret_code;
+
+ ret_code = lttng_destroy_session_ext(session_name, NULL);
+ return ret_code == LTTNG_OK ? 0 : -ret_code;
+}
+
+/*
+ * Ask the session daemon for all available sessions.
+ * Sets the contents of the sessions array.
+ * Returns the number of lttng_session entries in sessions;
+ * on error, returns a negative value.
+ */
+int lttng_list_sessions(struct lttng_session **out_sessions)
+{
+ int ret;
+ struct lttcomm_session_msg lsm;
+ const size_t session_size = sizeof(struct lttng_session) +
+ sizeof(struct lttng_session_extended);
+ size_t session_count, i;
+ struct lttng_session_extended *sessions_extended_begin;
+ struct lttng_session *sessions = NULL;
+
+ memset(&lsm, 0, sizeof(lsm));
+ lsm.cmd_type = LTTNG_LIST_SESSIONS;
+ /*
+ * Initialize out_sessions to NULL so it is initialized when
+ * lttng_list_sessions returns 0, thus allowing *out_sessions to
+ * be subsequently freed.
+ */
+ *out_sessions = NULL;
+ ret = lttng_ctl_ask_sessiond(&lsm, (void**) &sessions);
+ if (ret <= 0) {
+ goto end;
+ }
+ if (!sessions) {
+ ret = -LTTNG_ERR_FATAL;
+ goto end;
+ }
+
+ if (ret % session_size) {
+ ret = -LTTNG_ERR_UNK;
+ free(sessions);
+ goto end;
+ }
+ session_count = (size_t) ret / session_size;
+ sessions_extended_begin = (struct lttng_session_extended *)
+ (&sessions[session_count]);
+
+ /* Set extended session info pointers. */
+ for (i = 0; i < session_count; i++) {
+ struct lttng_session *session = &sessions[i];
+ struct lttng_session_extended *extended =
+ &(sessions_extended_begin[i]);
+
+ session->extended.ptr = extended;
+ }
+
+ ret = (int) session_count;
+ *out_sessions = sessions;
+end:
+ return ret;
+}
+
+enum lttng_error_code lttng_session_get_creation_time(
+ const struct lttng_session *session, uint64_t *creation_time)
+{
+ enum lttng_error_code ret = LTTNG_OK;
+ struct lttng_session_extended *extended;
+
+ if (!session || !creation_time || !session->extended.ptr) {
+ ret = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ extended = session->extended.ptr;
+ if (!extended->creation_time.is_set) {
+ /* Not created on the session daemon yet. */
+ ret = LTTNG_ERR_SESSION_NOT_EXIST;
+ goto end;
+ }
+ *creation_time = extended->creation_time.value;
+end:
+ return ret;
+}
+
+int lttng_set_session_shm_path(const char *session_name,
+ const char *shm_path)
+{
+ int ret;
+ struct lttcomm_session_msg lsm;
+
+ if (session_name == NULL) {
+ return -LTTNG_ERR_INVALID;
+ }
+
+ memset(&lsm, 0, sizeof(lsm));
+ lsm.cmd_type = LTTNG_SET_SESSION_SHM_PATH;
+
+ ret = lttng_strncpy(lsm.session.name, session_name,
+ sizeof(lsm.session.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ret = lttng_strncpy(lsm.u.set_shm_path.shm_path, shm_path ?: "",
+ sizeof(lsm.u.set_shm_path.shm_path));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ret = lttng_ctl_ask_sessiond(&lsm, NULL);
+end:
+ return ret;
+}
+
+/*
+ * Ask the session daemon for all available domains of a session.
+ * Sets the contents of the domains array.
+ * Returns the number of lttng_domain entries in domains;
+ * on error, returns a negative value.
+ */
+int lttng_list_domains(const char *session_name,
+ struct lttng_domain **domains)
+{
+ int ret;
+ struct lttcomm_session_msg lsm;
+
+ if (session_name == NULL) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ memset(&lsm, 0, sizeof(lsm));
+ lsm.cmd_type = LTTNG_LIST_DOMAINS;
+
+ ret = lttng_strncpy(lsm.session.name, session_name,
+ sizeof(lsm.session.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ ret = lttng_ctl_ask_sessiond(&lsm, (void**) domains);
+ if (ret < 0) {
+ goto error;
+ }
+
+ return ret / sizeof(struct lttng_domain);
+error:
+ return ret;
+}
+
+/*
+ * Ask the session daemon for all available channels of a session.
+ * Sets the contents of the channels array.
+ * Returns the number of lttng_channel entries in channels;
+ * on error, returns a negative value.
+ */
+int lttng_list_channels(struct lttng_handle *handle,
+ struct lttng_channel **channels)
+{
+ int ret, total_payload_received;
+ struct lttcomm_session_msg lsm;
+ char *reception_buffer = NULL;
+ size_t cmd_header_len = 0;
+ struct lttcomm_list_command_header *cmd_header = NULL;
+ struct lttng_dynamic_buffer tmp_buffer;
+
+ lttng_dynamic_buffer_init(&tmp_buffer);
+
+ if (handle == NULL) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ memset(&lsm, 0, sizeof(lsm));
+ lsm.cmd_type = LTTNG_LIST_CHANNELS;
+ ret = lttng_strncpy(lsm.session.name, handle->session_name,
+ sizeof(lsm.session.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
+
+ ret = lttng_ctl_ask_sessiond_fds_varlen(&lsm, NULL, 0, NULL, 0,
+ (void **) &reception_buffer, (void **) &cmd_header,
+ &cmd_header_len);
+ if (ret < 0) {
+ goto end;
+ }
+
+ total_payload_received = ret;
+
+ if (cmd_header_len != sizeof(*cmd_header)) {
+ ret = -LTTNG_ERR_FATAL;
+ goto end;
+ }
+
+ if (!cmd_header) {
+ ret = LTTNG_ERR_UNK;
+ goto end;
+ }
+
+ if (cmd_header->count > INT_MAX) {
+ ret = -LTTNG_ERR_OVERFLOW;
+ goto end;
+ }
+
+ {
+ enum lttng_error_code ret_code;
+ const struct lttng_buffer_view events_view =
+ lttng_buffer_view_init(reception_buffer, 0,
+ total_payload_received);
+
+ ret_code = lttng_channels_create_and_flatten_from_buffer(
+ &events_view, cmd_header->count, channels);
+ if (ret_code != LTTNG_OK) {
+ ret = -ret_code;
+ goto end;
+ }
+ }
+
+ ret = (int) cmd_header->count;
+end:
+ free(cmd_header);
+ free(reception_buffer);
+ return ret;
+}
+
+/*
+ * Ask the session daemon for all available events of a session channel.
+ * Sets the contents of the events array.
+ * Returns the number of lttng_event entries in events;
+ * on error, returns a negative value.
+ */
+int lttng_list_events(struct lttng_handle *handle,
+ const char *channel_name, struct lttng_event **events)
+{
+ int ret;
+ struct lttcomm_session_msg lsm = {};
+ struct lttng_payload reply;
+ struct lttng_payload_view lsm_view =
+ lttng_payload_view_init_from_buffer(
+ (const char *) &lsm, 0, sizeof(lsm));
+ unsigned int nb_events = 0;
+
+ /* Safety check. An handle and channel name are mandatory. */
+ if (handle == NULL || channel_name == NULL) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ lttng_payload_init(&reply);
+
+ /* Initialize command parameters. */
+ lsm.cmd_type = LTTNG_LIST_EVENTS;
+ ret = lttng_strncpy(lsm.session.name, handle->session_name,
+ sizeof(lsm.session.name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ret = lttng_strncpy(lsm.u.list.channel_name, channel_name,
+ sizeof(lsm.u.list.channel_name));
+ if (ret) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
+
+ /* Execute command against the session daemon. */
+ ret = lttng_ctl_ask_sessiond_payload(&lsm_view, &reply);
+ if (ret < 0) {
+ goto end;
+ }
+
+ {
+ const struct lttcomm_list_command_header *cmd_reply_header =
+ NULL;
+ const struct lttng_payload_view cmd_reply_header_view =
+ lttng_payload_view_from_payload(&reply, 0,
+ sizeof(*cmd_reply_header));
+
+ if (!lttng_payload_view_is_valid(&cmd_reply_header_view)) {
+ ret = -LTTNG_ERR_INVALID_PROTOCOL;
+ goto end;
+ }
+
+ cmd_reply_header = (const struct lttcomm_list_command_header *)
+ cmd_reply_header_view.buffer
+ .data;
+ if (cmd_reply_header->count > INT_MAX) {
+ ret = -LTTNG_ERR_OVERFLOW;
+ goto end;
+ }
+
+ nb_events = (unsigned int) cmd_reply_header->count;
+ }
+
+ {
+ enum lttng_error_code ret_code;
+ struct lttng_payload_view cmd_reply_payload = lttng_payload_view_from_payload(
+ &reply,
+ sizeof(struct lttcomm_list_command_header), -1);
+
+ ret_code = lttng_events_create_and_flatten_from_payload(
+ &cmd_reply_payload, nb_events, events);
+ if (ret_code != LTTNG_OK) {
+ ret = -((int) ret_code);
+ goto end;
+ }
+ }
+
+ ret = (int) nb_events;
+end:
+ lttng_payload_reset(&reply);
+ return ret;
+}
+
+/*
+ * Sets the tracing_group variable with name.
+ * This function allocates memory pointed to by tracing_group.
+ * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
+ */
+int lttng_set_tracing_group(const char *name)
+{
+ char *new_group;
+ if (name == NULL) {
+ return -LTTNG_ERR_INVALID;
+ }
+
+ if (asprintf(&new_group, "%s", name) < 0) {
+ return -LTTNG_ERR_FATAL;
+ }
+
+ free(tracing_group);
+ tracing_group = new_group;
+ new_group = NULL;
+
+ return 0;
+}
+
+int lttng_calibrate(struct lttng_handle *handle,
+ struct lttng_calibrate *calibrate)
+{
+ /*
+ * This command was removed in LTTng 2.9.
+ */
+ return -LTTNG_ERR_UND;
+}
+
+/*
+ * Set default channel attributes.
+ * If either or both of the arguments are null, attr content is zeroe'd.
+ */
+void lttng_channel_set_default_attr(struct lttng_domain *domain,
+ struct lttng_channel_attr *attr)
+{
+ struct lttng_channel_extended *extended;
+
+ /* Safety check */
+ if (attr == NULL || domain == NULL) {
+ return;
+ }
+
+ /* Save the pointer for later use */
+ extended = (struct lttng_channel_extended *) attr->extended.ptr;
+ memset(attr, 0, sizeof(struct lttng_channel_attr));
+
+ /* Same for all domains. */
+ attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
+ attr->tracefile_size = DEFAULT_CHANNEL_TRACEFILE_SIZE;
+ attr->tracefile_count = DEFAULT_CHANNEL_TRACEFILE_COUNT;
+
+ switch (domain->type) {
+ case LTTNG_DOMAIN_KERNEL:
+ attr->switch_timer_interval =
+ DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
+ attr->read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
+ attr->subbuf_size = default_get_kernel_channel_subbuf_size();
+ attr->num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
+ attr->output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
+ break;
+ case LTTNG_DOMAIN_UST:
+ switch (domain->buf_type) {
+ case LTTNG_BUFFER_PER_UID:
+ attr->subbuf_size = default_get_ust_uid_channel_subbuf_size();
+ attr->num_subbuf = DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM;
+ attr->output = DEFAULT_UST_UID_CHANNEL_OUTPUT;
+ attr->switch_timer_interval =
+ DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER;
+ attr->read_timer_interval =
+ DEFAULT_UST_UID_CHANNEL_READ_TIMER;
+ break;
+ case LTTNG_BUFFER_PER_PID:
+ default:
+ attr->subbuf_size = default_get_ust_pid_channel_subbuf_size();
+ attr->num_subbuf = DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM;
+ attr->output = DEFAULT_UST_PID_CHANNEL_OUTPUT;
+ attr->switch_timer_interval =
+ DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER;
+ attr->read_timer_interval =
+ DEFAULT_UST_PID_CHANNEL_READ_TIMER;
+ break;
+ }
+ default:
+ /* Default behavior: leave set to 0. */
+ break;
+ }
+
+ if (extended) {
+ lttng_channel_set_default_extended_attr(domain, extended);
+ }
+
+ /* Reassign the extended pointer. */
+ attr->extended.ptr = extended;
+}
+
+int lttng_channel_get_discarded_event_count(struct lttng_channel *channel,
+ uint64_t *discarded_events)
+{
+ int ret = 0;
+ struct lttng_channel_extended *chan_ext;
+
+ if (!channel || !discarded_events) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ chan_ext = channel->attr.extended.ptr;
+ if (!chan_ext) {
+ /*
+ * This can happen since the lttng_channel structure is
+ * used for other tasks where this pointer is never set.
+ */
+ *discarded_events = 0;
+ goto end;
+ }
+
+ *discarded_events = chan_ext->discarded_events;
+end:
+ return ret;
+}
+
+int lttng_channel_get_lost_packet_count(struct lttng_channel *channel,
+ uint64_t *lost_packets)
+{
+ int ret = 0;
+ struct lttng_channel_extended *chan_ext;
+
+ if (!channel || !lost_packets) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ chan_ext = channel->attr.extended.ptr;
+ if (!chan_ext) {
+ /*
+ * This can happen since the lttng_channel structure is
+ * used for other tasks where this pointer is never set.
+ */
+ *lost_packets = 0;
+ goto end;
+ }
+
+ *lost_packets = chan_ext->lost_packets;
+end:
+ return ret;
+}
+
+int lttng_channel_get_monitor_timer_interval(struct lttng_channel *chan,
+ uint64_t *monitor_timer_interval)
+{
+ int ret = 0;
+
+ if (!chan || !monitor_timer_interval) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ if (!chan->attr.extended.ptr) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ *monitor_timer_interval = ((struct lttng_channel_extended *)
+ chan->attr.extended.ptr)->monitor_timer_interval;
+end:
+ return ret;
+}
+
+int lttng_channel_set_monitor_timer_interval(struct lttng_channel *chan,
+ uint64_t monitor_timer_interval)
+{
+ int ret = 0;
+
+ if (!chan || !chan->attr.extended.ptr) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ((struct lttng_channel_extended *)
+ chan->attr.extended.ptr)->monitor_timer_interval =
+ monitor_timer_interval;
+end:
+ return ret;
+}
+
+int lttng_channel_get_blocking_timeout(struct lttng_channel *chan,
+ int64_t *blocking_timeout)
+{
+ int ret = 0;
+
+ if (!chan || !blocking_timeout) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ if (!chan->attr.extended.ptr) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ *blocking_timeout = ((struct lttng_channel_extended *)
+ chan->attr.extended.ptr)->blocking_timeout;
+end:
+ return ret;
+}
+
+int lttng_channel_set_blocking_timeout(struct lttng_channel *chan,
+ int64_t blocking_timeout)
+{
+ int ret = 0;
+ int64_t msec_timeout;
+
+ if (!chan || !chan->attr.extended.ptr) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ if (blocking_timeout < 0 && blocking_timeout != -1) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ /*
+ * LTTng-ust's use of poll() to implement this timeout mechanism forces
+ * us to accept a narrower range of values (msecs expressed as a signed
+ * 32-bit integer).
+ */
+ msec_timeout = blocking_timeout / 1000;
+ if (msec_timeout != (int32_t) msec_timeout) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ((struct lttng_channel_extended *)
+ chan->attr.extended.ptr)->blocking_timeout =
+ blocking_timeout;
+end:
+ return ret;
+}
+
+/*
+ * Check if session daemon is alive.
+ *
+ * Return 1 if alive or 0 if not.
+ * On error returns a negative value.
+ */
+int lttng_session_daemon_alive(void)
+{
+ int ret;
+
+ ret = set_session_daemon_path();
+ if (ret < 0) {
+ /* Error. */
+ return ret;
+ }
+
+ if (*sessiond_sock_path == '\0') {
+ /*
+ * No socket path set. Weird error which means the constructor
+ * was not called.
+ */
+ assert(0);