fds

The go-to FirewallD CLI app that doesn't suck.

What is fds?

Firewall management is often a task that you do once at the time of setting up a server. But if you're maintaining a server like a PRO, you are monitoring logs, and blocking malicious users as they come, on a regular basis.

FirewallD is a great firewall software. It has the concepts of zones, sources, and supports IP sets. However, its client app, firewall-cmd is far from user-friendly when it comes to blocking and managing blocked IP addresses. Furthermore, if you also use Cloudflare firewall, you also want to propagate your blocked IP addresses to it for best protection.

fds is the CLI client for FirewallD/Cloudflare, that you'll love to use any day. It is an alternative, client for FirewallD.

Use it for simple or complex banning tasks, instead of firewall-cmd.

Look how simple things are with fds:

fds block <country name>
fds block 1.2.3.4

It makes the task of managing your FirewallD easy and human-friendly.

Installation on CentOS/RHEL 7, 8

sudo yum -y install https://extras.getpagespeed.com/release-latest.rpm
sudo yum -y install fds

What fds can do

The fds is utility program for users of FirewallD. It is a helper to easily perform day-to-day firewall tasks:

• block users of Tor
• block countries
• block arbitrary IP addresses
• block the same over at Cloudflare

Integrations

By default, fds only operates with FirewallD.

To enable Cloudflare integration, run:

fds config

Block Tor

You can block all Tor exit nodes by running:

fds block tor

Note that since these addresses constantly change, you may want to run this command in a cron.

Ban a single IP

fds block 1.2.3.4

This blocks IP address in a proper(©) fashion by ensuring that the IP is in a set named networkblock4, that the set is a source to FirewallD's drop zone. Using IP sets is the corner stone of consistent firewall management!

Ban a country or a continent

fds block <Country Name>
fds block China
fds block Asia

You can list all country names available for blocking by running:

fds list countries

You can list all continents available for blocking by running:

fds list continents

Block using environment variables

You can set an environment variable REMOTE_ADDR with the value of desired block target, instead of supplying it as an argument. The destination block IP set basename can be specified using IPSET environment variable, e.g.:

REMOTE_ADDR=1.2.3.4 IPSET=honeypot fds block

The above command will block the IP 1.2.3.4 by adding it into honeypot4 IP set, which will be created automatically, if it didn't exist.

This is useful when invoking fds as a CGI script for auto-blocking bad actors upon access. See NGINX honeypot – the easiest and fastest way to block bots! for more details.

When fds detects these variables, it run in a CGI mode, meaning that its output will include HTTP headers, e.g.:

Status: 410 Gone
Content-type: text/plain

Adding IP address 1.2.3.4/32 to block set networkblock4
Reloading FirewallD to apply permanent configuration
Breaking connection with 1.2.3.4/32

--no-reload (-nr)

Use this optional flag to prevent FirewallD from being reloaded. This is only useful when adding multiple blocks, as it ensure faster blocking:

fds block 1.2.3.4 --no-reload
fds block 2.3.4.5 --no-reload
fds block Country1 --no-reload
...
fds block Country2

In the above example, we block some IP addresses and a few countries. The last block operation will reload FirewallD and actually apply our ban.

Alternatively, invoke all fds block with --no-reload option and invoke firewall-cmd --reload in the end.

List all blocked networks and countries

The following allows to easily see what is blocked:

fds list blocked

Unblock a country or IP/network

Use fds unblock ... like the following:

fds unblock China
fds unblock 1.2.3.4

Reset all bans

You can quickly remove all blocks (and by that, all IP sets associated with fds):

fds reset

Notes

The fds package automatically installs a cron job that syncs your blocked IP sets daily. So there is no need to do anything to ensure a country (or Tor) stays blocked.

Planned

• declare a CDN of servers and push blocking commands across those server from one place (ansible-like), useful for dynamic blocking from the central server (honeypot)
• drop outbound connections (shortcut to https://cogitantium.blogspot.com/2017/06/how-to-drop-outbound-connections-with.html)

See contributing guide for development setup (if not using packages).

Files

• not in use: /etc/fds.conf (info on currently blocked countries or otherwise small data sets suitable for a single config file)
• not in use: /var/lib/fds: zone files, (state data) + (info on what is currently blocked) (???)
• /var/cache/fds: cachecontrol cache