vsftpd via xinetd on debian

## make users, directory structure, etc.

 useradd ftpsecure -g users

 mkdir /srv/ftp/data
 mkdir /srv/ftp/data/alle 
 mkdir /srv/ftp/data/sta

 chown -R :users /srv/ftp/data/alle
 chmod g+w /srv/ftp/data/alle

 chown -R sts:users /srv/ftp/data/sts

# ls /srv/ftp
# [drwxr-xr-x root users]  /srv/ftp/data
#   [drwxr-xr-x sts users]  /srv/ftp/data/sts
#   [drwxrwxr-x root users]  /srv/ftp/data/alle

vsftpd.conf

 ### /etc/vsftpd.conf 

 listen=NO
 listen_ipv6=NO

 anonymous_enable=NO

 local_enable=YES
 write_enable=YES
 local_umask=022

 dirmessage_enable=YES
 use_localtime=YES

 connect_from_port_20=YES

 xferlog_enable=YES
 xferlog_file=/var/log/vsftpd.log
 xferlog_std_format=YES

 idle_session_timeout=600
 data_connection_timeout=120

 chroot_local_user=YES
 ls_recurse_enable=YES

 local_root=/srv/ftp/data
 secure_chroot_dir=/var/run/vsftpd/empty

 pam_service_name=vsftpd
 rsa_cert_file=/etc/ssl/private/vsftpd.pem

xinet.d-ftp

 ### /etc/xinetd.d/ftp
 service ftp
 {
   socket_type = stream
   wait = no
   user = root
   server = /usr/sbin/vsftpd
   log_on_success += HOST DURATION
   log_on_failure += HOST
   disable = no
  }

see also: https://www.linuxnet.ch/automatic-tunnels-with-xinetd-and-netcat/ (because it's fun)