+/*
+ * Connect to the LTTng session daemon.
+ *
+ * On success, return 0. On error, return -1.
+ */
+static int connect_sessiond(void)
+{
+ int ret;
+
+ ret = set_session_daemon_path();
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* Connect to the sesssion daemon */
+ ret = lttcomm_connect_unix_sock(sessiond_sock_path);
+ if (ret < 0) {
+ return ret;
+ }
+
+ sessiond_socket = ret;
+ connected = 1;
+
+ return 0;
+}
+
+/*
+ * Clean disconnect the session daemon.
+ */
+static int disconnect_sessiond(void)
+{
+ int ret = 0;
+
+ if (connected) {
+ ret = lttcomm_close_unix_sock(sessiond_socket);
+ sessiond_socket = 0;
+ connected = 0;
+ }
+
+ return ret;
+}
+
+/*
+ * ask_sessiond
+ *
+ * Ask the session daemon a specific command and put the data into buf.
+ *
+ * Return size of data (only payload, not header).
+ */
+static int ask_sessiond(enum lttcomm_sessiond_command lct, void **buf)
+{
+ int ret;
+ size_t size;
+ void *data = NULL;
+
+ ret = connect_sessiond();
+ if (ret < 0) {
+ goto end;
+ }
+
+ lsm.cmd_type = lct;
+
+ /* Send command to session daemon */
+ ret = send_data_sessiond();
+ if (ret < 0) {
+ goto end;
+ }
+
+ /* Get header from data transmission */
+ ret = recv_data_sessiond(&llm, sizeof(llm));
+ if (ret < 0) {
+ goto end;
+ }
+
+ /* Check error code if OK */
+ if (llm.ret_code != LTTCOMM_OK) {
+ ret = -llm.ret_code;
+ goto end;
+ }
+
+ size = llm.data_size;
+ if (size == 0) {
+ goto end;
+ }
+
+ data = (void*) malloc(size);
+
+ /* Get payload data */
+ ret = recv_data_sessiond(data, size);
+ if (ret < 0) {
+ free(data);
+ goto end;
+ }
+
+ *buf = data;
+ ret = size;
+
+end:
+ disconnect_sessiond();
+ return ret;
+}
+