Prerequisites:
* The ss command is available, kernel is compiled with option CONFIG_INET_DIAG_DESTROY.
* Ufw version is => 0.36 (released in 2018)
* Now using "prepend" instead of "insert" to be able to handle IPv6 addresses correctly. The current action will fail for IPv6 addresses.
* Now application names containing a space should handled correctly, solves https://github.com/fail2ban/fail2ban/pull/1532
* Now closing IPv4 and IPv6 connections (if any) from the ip that is being banned. The current action will leave them open.
Using ss to accomplish this. For this to work the kernel needs to be compiled with the CONFIG_INET_DIAG_DESTROY option.
My system apparently is compiled that way.
On Ubuntu 15.04 the ufw action was not working.
- With empty <application>, receiving errors:
2015-04-24 16:28:35,204 fail2ban.filter [8527]: INFO [sshd] Found 43.255.190.157
2015-04-24 16:28:35,695 fail2ban.actions [8527]: NOTICE [sshd] Ban 43.255.190.157
2015-04-24 16:28:35,802 fail2ban.action [8527]: ERROR [ -n "" ] && app="app " -- stdout: b''
2015-04-24 16:28:35,803 fail2ban.action [8527]: ERROR [ -n "" ] && app="app " -- stderr: b''
2015-04-24 16:28:35,803 fail2ban.action [8527]: ERROR [ -n "" ] && app="app " -- returned 1
- With action = ufw[application=OpenSSH], it was silently not doing
anything (no errors after "Ban x.x.x.x", but no IP addresses in ufw
status).
Re-arranged the bash commands on two lines, and it works with or without
<application>.
Sergey G. Brester