Di seguito riporto il file di configurazione del server FTP "ProFTPD" a me ideale:
# /etc/proftpd/proftpd.conf — This is a basic ProFTPD configuration file.
# To really apply changes reload proftpd after modifications.
# Includes DSO modules
Include /etc/proftpd/modules.conf
# Set off to disable IPv6 support which is annoying on IPv4 only boxes.
UseIPv6 off
ServerName "Debian"
ServerType standalone
DeferWelcome off
MultilineRFC2228 on
DefaultServer on
ShowSymlinks on
TimeoutNoTransfer 600
TimeoutStalled 600
TimeoutIdle 1200
DisplayLogin welcome.msg
DisplayFirstChdir .message
ListOptions "-l"
DenyFilter \*.*/
# Port 21 is the standard FTP port.
Port 21
# PassivePorts 49152 65534
# To prevent DoS attacks, set the maximum number of child processes
# to 30. Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd)
MaxInstances 30
# Set the user and group that the server normally runs at.
User proftpd
Group ftp
DefaultRoot ~
# Umask 022 is a good standard umask to prevent new files and dirs
# (second parm) from being group and world writable.
Umask 022 022
# Normally, we want files to be overwriteable.
AllowOverwrite on
# PersistentPasswd off
# Be warned: use of this directive impacts CPU average load!
# Uncomment this if you like to see progress and transfer rate with ftpwho
# in downloads. That is not needed for uploads rates.
# UseSendFile off
TransferLog /var/log/proftpd/xferlog
SystemLog /var/log/proftpd/proftpd.log
<IfModule mod_tls.c>
TLSEngine off
</IfModule>
<IfModule mod_quota.c>
QuotaEngine on
</IfModule>
<IfModule mod_ratio.c>
Ratios on
</IfModule>
# Delay engine reduces impact of the so-called Timing Attack described in
# http://security.lss.hr/index.php?page=details&ID=LSS-2004-10-02
# It is on by default.
<IfModule mod_delay.c>
DelayEngine on
</IfModule>
<IfModule mod_ctrls.c>
ControlsEngine on
ControlsMaxClients 2
ControlsLog /var/log/proftpd/controls.log
ControlsInterval 5
ControlsSocket /var/run/proftpd/proftpd.sock
</IfModule>
<IfModule mod_ctrls_admin.c>
AdminControlsEngine on
</IfModule>
# A basic anonymous configuration, no upload directories.
# <Anonymous ~ftp>
# User ftp
# Group nogroup
# # We want clients to be able to login with "anonymous" as well as "ftp"
# UserAlias anonymous ftp
# # Cosmetic changes, all files belongs to ftp user
# DirFakeUser on ftp
# DirFakeGroup on ftp
#
# RequireValidShell off
#
# # Limit the maximum number of anonymous logins
# MaxClients 10
#
# # We want 'welcome.msg' displayed at login, and '.message' displayed
# # in each newly chdired directory.
# DisplayLogin welcome.msg
# DisplayFirstChdir .message
#
# # Limit WRITE everywhere in the anonymous chroot
# <Directory *>
# <Limit WRITE>
# DenyAll
# </Limit>
# </Directory>
#
# # Uncomment this if you're brave.
# # <Directory incoming>
# # # Umask 022 is a good standard umask to prevent new files and dirs
# # # (second parm) from being group and world writable.
# # Umask 022 022
# # <Limit READ WRITE>
# # DenyAll
# # </Limit>
# # <Limit STOR>
# # AllowAll
# # </Limit>
# # </Directory>
#
# </Anonymous>
In definitiva è il file di configurazione originale installando proftpd via apt-get con qualche piccola modifica per adattarlo alle mie esigenze. Una di queste è la direttiva DefaultRoot ~ che consente di vincolare l'accesso FTP degli utenti alla sola cartella (e sottocartelle) a loro assegnata di default.
Scritto da: Stefano