/usr/include/ is in libosip2-dev 4.0.0-3ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/osipparser2/
/usr/include/osipparser2/osip_parser.h
/usr/include/osipparser2/osip_body.h
/usr/include/osipparser2/osip_uri.h
/usr/include/osipparser2/sdp_message.h
/usr/include/osipparser2/osip_const.h
/usr/include/osipparser2/osip_port.h
/usr/include/osipparser2/headers/
/usr/include/osipparser2/headers/osip_alert_info.h
/usr/include/osipparser2/headers/osip_authentication_info.h
/usr/include/osipparser2/headers/osip_www_authenticate.h
/usr/include/osipparser2/headers/osip_contact.h
/usr/include/osipparser2/headers/osip_accept_language.h
/usr/include/osipparser2/headers/osip_from.h
/usr/include/osipparser2/headers/osip_via.h
/usr/include/osipparser2/headers/osip_proxy_authorization.h
/usr/include/osipparser2/headers/osip_mime_version.h
/usr/include/osipparser2/headers/osip_cseq.h
/usr/include/osipparser2/headers/osip_error_info.h
/usr/include/osipparser2/headers/osip_route.h
/usr/include/osipparser2/headers/osip_call_info.h
/usr/include/osipparser2/headers/osip_accept.h
/usr/include/osipparser2/headers/osip_to.h
/usr/include/osipparser2/headers/osip_content_disposition.h
/usr/include/osipparser2/headers/osip_accept_encoding.h
/usr/include/osipparser2/headers/osip_content_length.h
/usr/include/osipparser2/headers/osip_content_type.h
/usr/include/osipparser2/headers/osip_allow.h
/usr/include/osipparser2/headers/osip_proxy_authentication_info.h
/usr/include/osipparser2/headers/osip_call_id.h
/usr/include/osipparser2/headers/osip_authorization.h
/usr/include/osipparser2/headers/osip_proxy_authenticate.h
/usr/include/osipparser2/headers/osip_content_encoding.h
/usr/include/osipparser2/headers/osip_header.h
/usr/include/osipparser2/headers/osip_record_route.h
/usr/include/osipparser2/osip_md5.h
/usr/include/osipparser2/osip_message.h
/usr/include/osipparser2/osip_list.h
/usr/include/osipparser2/osip_headers.h
/usr/include/osip2/
/usr/include/osip2/osip_mt.h
/usr/include/osip2/osip_dialog.h
/usr/include/osip2/osip_time.h
/usr/include/osip2/osip_condv.h
/usr/include/osip2/osip_fifo.h
/usr/include/osip2/osip.h