nslu:ftp_server

Set up VSFTP

Download and install the VSFTPD package and XINETD package

# ipkg install vsftpd
Package vsftpd (2.0.6-2) installed in root is up to date.
Nothing to be done
# ipkg install xinetd
Package xinetd (2.3.14-7) installed in root is up to date.
Nothing to be done
#

Make a jailed user for outside access. We will poke a hole through our firewall to allow external FTP access.

adduser -h /home/ftpuser ftpuser
passwd ftpuser

Designate this user as a JAILED user. /opt/etc/vsftpd.chroot_list

ftpuser

/opt/etc/vsftpd.conf

# Example config file /opt/etc/vsftpd.conf
#
# The default compiled in settings are fairly paranoid. This sample file
# loosens things up a bit, to make the ftp daemon more usable.
# Please see vsftpd.conf.5 for all compiled in defaults.
#
# READ THIS: This example file is NOT an exhaustive list of vsftpd options.
# Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's
# capabilities.
#
# Allow anonymous FTP? (Beware - allowed by default if you comment this out).
anonymous_enable=NO
#
# Uncomment this to allow local users to log in.
local_enable=YES
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES
#
# Default umask for local users is 077. You may wish to change this to 022,
# if your users expect that (022 is used by most other ftpd's)
local_umask=022
#
# Uncomment this to allow the anonymous FTP user to upload files. This only
# has an effect if the above global write enable is activated. Also, you will
# obviously need to create a directory writable by the FTP user.
#anon_upload_enable=YES
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES
#
# Activate directory messages - messages given to remote users when they
# go into a certain directory.
dirmessage_enable=YES
#
# Activate logging of uploads/downloads.
xferlog_enable=YES
#
# Make sure PORT transfer connections originate from port 20 (ftp-data).
connect_from_port_20=YES
#
# If you want, you can arrange for uploaded anonymous files to be owned by
# a different user. Note! Using "root" for uploaded files is not
# recommended!
#chown_uploads=YES
#chown_username=whoever
#
# You may override where the log file goes if you like. The default is shown
# below.
vsftpd_log_file=/opt/var/log/vsftpd.log
#
# If you want, you can have your log file in standard ftpd xferlog format
#xferlog_std_format=YES
#
# You may change the default value for timing out an idle session.
#idle_session_timeout=600
#
# You may change the default value for timing out a data connection.
#data_connection_timeout=120
#
# It is recommended that you define on your system a unique user which the
# ftp server can use as a totally isolated and unprivileged user.
nopriv_user=ftp
#
# Enable this and the server will recognise asynchronous ABOR requests. Not
# recommended for security (the code is non-trivial). Not enabling it,
# however, may confuse older FTP clients.
#async_abor_enable=YES
#
# By default the server will pretend to allow ASCII mode but in fact ignore
# the request. Turn on the below options to have the server actually do ASCII
# mangling on files when in ASCII mode.
# Beware that turning on ascii_download_enable enables malicious remote parties
# to consume your I/O resources, by issuing the command "SIZE /big/file" in
# ASCII mode.
# These ASCII options are split into upload and download because you may wish
# to enable ASCII uploads (to prevent uploaded scripts etc. from breaking),
# without the DoS risk of SIZE and ASCII downloads. ASCII mangling should be
# on the client anyway..
#ascii_upload_enable=YES
#ascii_download_enable=YES
#
# You may fully customise the login banner string:
ftpd_banner=Welcome to the NSLU2 vsftp daemon.
#
# You may specify a file of disallowed anonymous e-mail addresses. Apparently
# useful for combatting certain DoS attacks.
#deny_email_enable=YES
# (default follows)
#banned_email_file=/opt/etc/vsftpd.banned_emails
#
# You may specify an explicit list of local users to chroot() to their home
# directory. If chroot_local_user is YES, then this list becomes a list of
# users to NOT chroot().
chroot_list_enable=YES
# (default follows)
chroot_list_file=/opt/etc/vsftpd.chroot_list
#
# You may activate the "-R" option to the builtin ls. This is disabled by
# default to avoid remote users being able to cause excessive I/O on large
# sites. However, some broken FTP clients such as "ncftp" and "mirror" assume
# the presence of the "-R" option, so there is a strong case for enabling it.
ls_recurse_enable=YES

Allow the XINETD super service to start-up FTP daemons for us.

/opt/etc/xinetd.d

service ftp
{
socket_type = stream
wait = no
user = root
server = /opt/sbin/vsftpd
server_args = /opt/etc/vsftpd.conf
nice = 10
disable = no
only_from = 0.0.0.0/0
}

Update: After having this configuration running and open to big bad internet I noticed a number of repeated attempts to hack into my FTP server. So I restricted it to only those networks where I know people may be accessing it from. It could be more restrictive but this seems to have done the trick for the moment.

#only_from = 0.0.0.0/0
only_from += .btcentralplus.com
only_from += .btopenworld.com
only_from += .virginmedia.com
only_from += .ntl.com
only_from += .optusnet.com.au
only_from += .bigpond.com.au
# and Locally too.
only_from += 192.168.1.0/24
  • nslu/ftp_server.txt
  • Last modified: 2009/11/27 17:54
  • by 127.0.0.1