autoban:: Simple, efficient Ruby "fail2ban"-like script
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/bin/env/ruby | |
# A more efficient and documented autoban.rb | |
# Jamie - index.hm. Released under MIT. | |
# This won't work with binary journal logs - the 'systemd/journal' gem doesn't work universally | |
$ssh_port = 1234 | |
$network = ["127.0.0.0/8", "10.0.0.0/8", "192.168.0.0/16"] | |
require "shellwords" | |
require "etc" | |
require "ipaddr" | |
$network.map! { |n| IPAddr.new(n) } | |
def tail(files) | |
begin | |
# Iterate through the supplied log files, open a descriptor, seek to the end of the file | |
files.map! { |f| File.open(f, "r") }.each { |f| f.seek(0, IO::SEEK_END) } | |
rescue | |
abort "Failed to watch logfiles. Are you running me as root? I need this to run iptables!" | |
end | |
loop do | |
# Watch FDs for changes, yield with every new line that appears | |
select(files, nil, nil, 30)[0].each { |f| line = f.gets; yield line if line.to_s.chomp != "" } | |
end | |
end | |
tail %w(/var/log/secure /var/log/messages) do | line | | |
puts line | |
# Is the error from | |
if result = /(Failed password for (.*)|Invalid user (.*)) from (.*)/.match(line) | |
ip = result[4]; message = "Possible break-in attempt from #{ip} (#{result[3]}#{result[2]})" | |
next unless $network.none? { |i| i == ip } | |
send "system", *%W(ip route add blackhole #{ip}/32) # Get lost | |
end | |
if result = /([0-9a-f\.]*) to ([0-9a-f\.]*) ports/i.match(line) | |
ip = result[1]; message = "Potential port map from IP #{ip}" | |
next unless $network.none? { |i| i == ip } | |
send "system", *%W(/sbin/iptables -I INPUT -s #{ip} -p tcp --dport #{$ssh_port} -j REJECT --reject-with tcp-reset) | |
end | |
system "send_alert", message if message | |
end |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment