dfui_fe_receive
dfui_fe_receive(c, &msgtype, &payload);
dfui_fe_receive(c, &msgtype, &payload);
if (!dfui_fe_receive(c, &msgtype, &v)) {
dfui_err_t dfui_fe_receive(struct dfui_connection *, char *, void **);
dfui_fe_receive(cp, &msgtype, &payload);