Limit user login source

I'm using OwnCloud 9.1
Is there any way to limit user login based on source IP address?
For example, user: admin
I don't need to login as admin from anywhere in the world, I'd like to narrow it to my LAN (192.168.0.0/24)
How can I do this?

The enterprise version has a file-firewall that allows you to limit the ip range. But normally it is limiting the access for certain files, not sure if that is also possible for the login. Would be perhaps a nice option to add, however for owncloud it is only in the enterprise version. If you need such options in an open source version, you can have a look at owncloud-forks.

I'm not sure if it is possible to write a special rule for mod_security or fail2ban.