Set up anonymous FTP upload on Oracle Linux

Just because this took a little longer than I expected, here’s a quick howto for setting up an anonymous FTP drop-off on Oracle Linux, which I use as a simple way to transfer files out of my Virtual Machines.

Install vsftpd

$ sudo yum -y install vsftpd

Configure iptables

As FTP is a more complicated protocol than most, there is a special netfilter module required in order to correctly keep track of connections.

# You will perhaps want to change the insert number here.
$ sudo iptables -I INPUT 4 -m state --state NEW -p tcp --dport 21 -j ACCEPT
$ sudo /etc/init.d/iptables save

Add nf_conntrack_ftp to IPTABLES_MODULES

$ sudo vi /etc/sysconfig/iptables-config

Then load the module rather than reboot

$ sudo modprobe nf_conntrack_ftp

Create /incoming

Create /incoming area and ensure it has the correct file permissions and SELinux context. This is the bit which had me stumped for a little while, as I didn’t know about allow_ftpd_anon_write, and while I normally just disable SELinux, I do also like to know how things should work (and be able to write about them!):

$ sudo mkdir /var/ftp/incoming
$ sudo chown ftp:ftp /var/ftp/incoming

# This allows anonymous users to upload, but not see what''s in the directory
$ sudo chmod 750 /var/ftp/incoming

$ sudo chcon -u system_u -t public_content_rw_t /var/ftp/incoming
$ sudo setsebool allow_ftpd_anon_write=1

Configure vsftpd

$ sudo vi /etc/vsftpd/vsftpd.conf

anon_upload_enable=YES

Startup

Finally, enable and start vsftpd:

$ sudo chkconfig vsftpd on
$ sudo /etc/init.d/vsftpd start

And that’s it, you should now be able to FTP as anonymous and upload files into /incoming.

All blog posts