/usr/include/libndpi-1.4.0/ is in libndpi-dev 1.4.0+svn6932-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libndpi-1.4.0/libndpi/
/usr/include/libndpi-1.4.0/libndpi/linux_compat.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_api.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_credis.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_debug_functions.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_define.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_macros.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_main.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_protocol_history.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_protocols_osdpi.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_public_functions.h
/usr/include/libndpi-1.4.0/libndpi/ndpi_structs.h