+ 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);