/usr/include/OpenIPMI/internal/ is in libopenipmi-dev 2.0.16-1.4.
This file is owned by root:root, with mode 0o755.
..
/usr/include/OpenIPMI/internal/ilist.h
/usr/include/OpenIPMI/internal/ipmi_control.h
/usr/include/OpenIPMI/internal/ipmi_domain.h
/usr/include/OpenIPMI/internal/ipmi_entity.h
/usr/include/OpenIPMI/internal/ipmi_event.h
/usr/include/OpenIPMI/internal/ipmi_fru.h
/usr/include/OpenIPMI/internal/ipmi_int.h
/usr/include/OpenIPMI/internal/ipmi_locks.h
/usr/include/OpenIPMI/internal/ipmi_malloc.h
/usr/include/OpenIPMI/internal/ipmi_mc.h
/usr/include/OpenIPMI/internal/ipmi_oem.h
/usr/include/OpenIPMI/internal/ipmi_sel.h
/usr/include/OpenIPMI/internal/ipmi_sensor.h
/usr/include/OpenIPMI/internal/ipmi_utils.h
/usr/include/OpenIPMI/internal/locked_list.h
/usr/include/OpenIPMI/internal/md2.h
/usr/include/OpenIPMI/internal/md5.h
/usr/include/OpenIPMI/internal/opq.h