/usr/include/ is in libsmbclient-raw-dev 4.0.0~alpha18.dfsg1-4ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/samba-4.0/
/usr/include/samba-4.0/gen_ndr/
/usr/include/samba-4.0/gen_ndr/drsblobs.h
/usr/include/samba-4.0/gen_ndr/drsuapi.h
/usr/include/samba-4.0/gen_ndr/ndr_drsblobs.h
/usr/include/samba-4.0/gen_ndr/ndr_drsuapi.h
/usr/include/samba-4.0/ndr/
/usr/include/samba-4.0/ndr/ndr_drsblobs.h
/usr/include/samba-4.0/ndr/ndr_drsuapi.h
/usr/include/samba-4.0/read_smb.h
/usr/include/samba-4.0/smb2_constants.h
/usr/include/samba-4.0/smb2_create_blob.h
/usr/include/samba-4.0/smb2_signing.h
/usr/include/samba-4.0/smb_cli.h
/usr/include/samba-4.0/smb_cliraw.h
/usr/include/samba-4.0/smb_common.h
/usr/include/samba-4.0/smb_constants.h
/usr/include/samba-4.0/smb_raw.h
/usr/include/samba-4.0/smb_raw_interfaces.h
/usr/include/samba-4.0/smb_raw_signing.h
/usr/include/samba-4.0/smb_raw_trans2.h
/usr/include/samba-4.0/smb_request.h
/usr/include/samba-4.0/smb_seal.h
/usr/include/samba-4.0/smb_signing.h
/usr/include/samba-4.0/smb_unix_ext.h
/usr/include/samba-4.0/smb_util.h