mirror of https://github.com/fail2ban/fail2ban
350 lines
11 KiB
Perl
Executable File
350 lines
11 KiB
Perl
Executable File
#!/usr/bin/perl
|
|
|
|
# -------------------------------------------------------
|
|
# -=- <check_fail2ban> -=-
|
|
# -------------------------------------------------------
|
|
#
|
|
# Description : This plugin checks if the fail2ban server is running
|
|
# and how many IPs are currently banned.
|
|
#
|
|
#
|
|
# inspired by the work of Sebastian Mueller - http://www.elchtest.eu
|
|
#
|
|
#
|
|
# Version : 0.1
|
|
# -------------------------------------------------------
|
|
# In :
|
|
# - see the How to use section
|
|
#
|
|
# Out :
|
|
# - only print on the standard output
|
|
#
|
|
# Features :
|
|
# - perfdata output
|
|
# - works with only a specific jail
|
|
#
|
|
# Fix Me/Todo :
|
|
# - too many things ;) but let me know what do you think about it
|
|
#
|
|
# ####################################################################
|
|
|
|
# ####################################################################
|
|
# GPL v2
|
|
# This program is free software; you can redistribute it and/or
|
|
# modify it under the terms of the GNU General Public License
|
|
# as published by the Free Software Foundation; either version 2
|
|
# of the License, or (at your option) any later version.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program; if not, write to the Free Software
|
|
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
# ####################################################################
|
|
|
|
# ####################################################################
|
|
# How to use :
|
|
# ------------
|
|
#
|
|
# Just have to run the following command:
|
|
# $ ./check_fail2ban --help
|
|
#
|
|
# If you need to use this script with NRPE you just have to do the
|
|
# following steps:
|
|
#
|
|
# 1 allow your user to run the script with the sudo rights. Just add
|
|
# something like that in your /etc/sudoers (use visudo) :
|
|
# nagios ALL=(ALL) NOPASSWD: /<path-to>/check_fail2ban
|
|
#
|
|
# 2 then just add this kind of line in your NRPE config file :
|
|
# command[check_fail2ban]=/usr/bin/sudo /<path-to>/check_fail2ban
|
|
#
|
|
# 3 don't forget to restart your NRPE daemon
|
|
#
|
|
#
|
|
# /!\ be careful to let no one able to update the check_fail2ban ;)
|
|
# ------------------------------------------------------------------------------
|
|
#
|
|
# ####################################################################
|
|
|
|
# ####################################################################
|
|
# Changelog :
|
|
# -----------
|
|
#
|
|
# --------------------------------------------------------------------
|
|
# Date:12/03/2013 Version:0.1 Author:Erwan Ben Souiden
|
|
# >> creation
|
|
# ####################################################################
|
|
|
|
# ####################################################################
|
|
# Don't touch anything under this line!
|
|
# You shall not pass - Gandalf is watching you
|
|
# ####################################################################
|
|
|
|
use strict;
|
|
use warnings;
|
|
use Getopt::Long qw(:config no_ignore_case);
|
|
|
|
# Generic variables
|
|
# -----------------
|
|
my $version = '0.1';
|
|
my $author = 'Erwan Labynocle Ben Souiden';
|
|
my $a_mail = 'erwan@aleikoum.net';
|
|
my $script_name = 'check_fail2ban';
|
|
my $verbose_value = 0;
|
|
my $version_value = 0;
|
|
my $more_value = 0;
|
|
my $help_value = 0;
|
|
my $perfdata_value = 0;
|
|
my %ERRORS=('OK'=>0,'WARNING'=>1,'CRITICAL'=>2,'UNKNOWN'=>3,'DEPENDENT'=>4);
|
|
|
|
# Plugin default variables
|
|
# ------------------------
|
|
my $display = 'CHECK FAIL2BAN ACTIVITY';
|
|
my ($critical,$warning) = (2,1);
|
|
my $fail2ban_client_path = '/usr/bin/fail2ban-client';
|
|
my $fail2ban_socket = '';
|
|
my $jail_specific = '';
|
|
my $jail_name = '';
|
|
|
|
GetOptions (
|
|
'P=s' => \ $fail2ban_client_path,
|
|
'path-fail2ban_client=s' => \ $fail2ban_client_path,
|
|
'j=s' => \ $jail_specific,
|
|
'jail=s' => \ $jail_specific,
|
|
'w=i' => \ $warning,
|
|
'warning=i' => \ $warning,
|
|
'socket=s' => \ $fail2ban_socket,
|
|
'S=s' => \ $fail2ban_socket,
|
|
'c=i' => \ $critical,
|
|
'critical=i' => \ $critical,
|
|
'V' => \ $version_value,
|
|
'version' => \ $version_value,
|
|
'h' => \ $help_value,
|
|
'H' => \ $help_value,
|
|
'help' => \ $help_value,
|
|
'display=s' => \ $display,
|
|
'D=s' => \ $display,
|
|
'perfdata' => \ $perfdata_value,
|
|
'p' => \ $perfdata_value,
|
|
'v' => \ $verbose_value,
|
|
'verbose' => \ $verbose_value
|
|
);
|
|
|
|
print_usage() if ($help_value);
|
|
print_version() if ($version_value);
|
|
|
|
|
|
# Syntax check of your specified options
|
|
# --------------------------------------
|
|
|
|
print "DEBUG : fail2ban_client_path: $fail2ban_client_path\n" if ($verbose_value);
|
|
if (($fail2ban_client_path eq "")) {
|
|
print $display.'- one or more following arguments are missing: fail2ban_client_path'."\n";
|
|
exit $ERRORS{"UNKNOWN"};
|
|
}
|
|
|
|
if(! -x $fail2ban_client_path) {
|
|
print $display.' - '.$fail2ban_client_path.' is not executable by you'."\n";
|
|
exit $ERRORS{"UNKNOWN"};
|
|
}
|
|
print "DEBUG : $fail2ban_client_path exists and is executable\n" if ($verbose_value);
|
|
|
|
my $fail2ban_cmd = $fail2ban_client_path;
|
|
$fail2ban_cmd .= " -s $fail2ban_socket" if ($fail2ban_socket);
|
|
|
|
print "DEBUG : final fail2ban command: $fail2ban_cmd\n" if ($verbose_value);
|
|
|
|
print "DEBUG : warning threshold : $warning, critical threshold : $critical\n" if ($verbose_value);
|
|
if (($critical < 0) or ($warning < 0) or ($critical < $warning)) {
|
|
print $display.' - the thresholds must be integers and the critical threshold higher or equal than the warning threshold'."\n";
|
|
exit $ERRORS{"UNKNOWN"};
|
|
}
|
|
|
|
# Core script
|
|
# -----------
|
|
my ($how_many_jail,$how_many_banned,$return_print,$perf_print,$plugstate) = (0,0,"","","OK");
|
|
|
|
|
|
### Test the connection to the fail2ban server
|
|
my @command_output = `$fail2ban_cmd ping`;
|
|
my $return_code = $?;
|
|
if ($return_code) {
|
|
print $display.'CRITICAL - non-zero exit code during testing fail2ban-client ping, check if the server is running and if you have the good permissions';
|
|
exit $ERRORS{"CRITICAL"};
|
|
}
|
|
else {
|
|
print "DEBUG : it seems the connection with the fail2ban server is ok\n" if ($verbose_value);
|
|
}
|
|
|
|
|
|
### Only if you specify one jail
|
|
if ($jail_specific) {
|
|
my $current_ban_number = currently_ban("$fail2ban_cmd","$jail_specific");
|
|
if ($current_ban_number == -1) {
|
|
print $display.' - CRITICAL - impossible to retrieve info about the jail '.$jail_specific;
|
|
exit $ERRORS{"CRITICAL"};
|
|
}
|
|
else {
|
|
$how_many_banned = int($current_ban_number);
|
|
$return_print = $how_many_banned.' current banned IP(s) for the specific jail '.$jail_specific;
|
|
$perf_print .= "$current_ban_number " if ($perfdata_value);
|
|
}
|
|
}
|
|
### To analyze all the jail
|
|
else {
|
|
# Retrieve the jails list
|
|
my @jail_list = obtain_jail_list("$fail2ban_cmd");
|
|
if ($jail_list[0] eq "-1") {
|
|
print $display.' - CRITICAL - impossible to retrieve the jail list'."\n";
|
|
exit $ERRORS{"CRITICAL"};
|
|
}
|
|
|
|
foreach (@jail_list) {
|
|
$how_many_jail ++;
|
|
|
|
my $jail_name = $_;
|
|
$jail_name =~ tr/ //ds;
|
|
|
|
my $current_ban_number = currently_ban("$fail2ban_cmd","$jail_name");
|
|
if ($current_ban_number == -1) {
|
|
print "DEBUG : problem to parse the current banned IPs for jail $jail_name\n" if ($verbose_value);
|
|
}
|
|
else {
|
|
print "DEBUG : the jail $jail_name has currently $current_ban_number banned IPs\n" if ($verbose_value);
|
|
$how_many_banned += int($current_ban_number);
|
|
$perf_print .= "$jail_name.currentBannedIP=$current_ban_number " if ($perfdata_value);
|
|
}
|
|
}
|
|
$return_print = $how_many_jail.' detected jails with '.$how_many_banned.' current banned IP(s)';
|
|
}
|
|
|
|
### Final
|
|
$plugstate = "CRITICAL" if ($how_many_banned >= $critical);
|
|
$plugstate = "WARNING" if (($how_many_banned >= $warning) && ($how_many_banned < $critical));
|
|
|
|
$return_print = $display." - ".$plugstate." - ".$return_print;
|
|
$return_print .= " | $perf_print" if ($perfdata_value);
|
|
|
|
print $return_print;
|
|
exit $ERRORS{"$plugstate"};
|
|
|
|
|
|
# ####################################################################
|
|
# function 1 : display the help
|
|
# -----------------------------
|
|
sub print_usage {
|
|
print <<EOT;
|
|
$script_name version $version by $author
|
|
|
|
This plugin checks if the fail2ban server is running and how many IPs are currently banned.
|
|
You can use this plugin to monitor all the jails or just a specific jail.
|
|
|
|
Usage: /<path-to>/$script_name [-p] [-D "$display"] [-v] [-c 2] [-w 1] [-s /<path-to>/socket] [-P /usr/bin/fail2ban-client]
|
|
|
|
Options:
|
|
-h, --help
|
|
Print detailed help screen
|
|
-V, --version
|
|
Print version information
|
|
-D, --display=STRING
|
|
To modify the output display
|
|
default is "CHECK FAIL2BAN ACTIVITY"
|
|
-P, --path-fail2ban_client=STRING
|
|
Specify the path to the tw_cli binary
|
|
default value is /usr/bin/fail2ban-client
|
|
-c, --critical=INT
|
|
Specify a critical threshold
|
|
default is 2
|
|
-w, --warning=INT
|
|
Specify a warning threshold
|
|
default is 1
|
|
-s, --socket=STRING
|
|
Specify a socket path
|
|
default is unset
|
|
-p, --perfdata
|
|
If you want to activate the perfdata output
|
|
-v, --verbose
|
|
Show details for command-line debugging (Nagios may truncate the output)
|
|
|
|
Send email to $a_mail if you have questions
|
|
regarding use of this software. To submit patches or suggest improvements,
|
|
send email to $a_mail
|
|
This plugin has been created by $author
|
|
|
|
Hope you will enjoy it ;)
|
|
|
|
Remember :
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License
|
|
as published by the Free Software Foundation; either version 2
|
|
of the License, or (at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
|
|
EOT
|
|
exit $ERRORS{"UNKNOWN"};
|
|
}
|
|
|
|
# function 2 : display version information
|
|
# ----------------------------------------
|
|
sub print_version {
|
|
print <<EOT;
|
|
$script_name version $version
|
|
EOT
|
|
exit $ERRORS{"UNKNOWN"};
|
|
}
|
|
|
|
# function 3 : return the jail list
|
|
# ---------------------------------
|
|
sub obtain_jail_list {
|
|
my ($fail2ban_client_path) = @_;
|
|
|
|
my @command_output = `$fail2ban_client_path status`;
|
|
my $return_code = $?;
|
|
if ($return_code) {
|
|
return -1;
|
|
}
|
|
|
|
my @jail_list;
|
|
foreach (@command_output) {
|
|
if ($_=~/^.*Jail list:\t+(.*)/) {
|
|
print "DEBUG : jails list: $1\n" if ($verbose_value);
|
|
@jail_list = split(/,/, $1);
|
|
}
|
|
}
|
|
|
|
return @jail_list;
|
|
}
|
|
|
|
# function 4 : return how many IP are currently ban for a given jail
|
|
# ------------------------------------------------------------------
|
|
sub currently_ban {
|
|
my ($fail2ban_client_path,$jail_name) = @_;
|
|
|
|
my @command_output = `$fail2ban_client_path status $jail_name`;
|
|
my $return_code = $?;
|
|
if ($return_code) {
|
|
return -1;
|
|
}
|
|
|
|
foreach (@command_output) {
|
|
if ($_=~/^.*Currently banned:\t+(.*)/) {
|
|
my $current_count = $1;
|
|
$current_count =~ tr/ //ds;
|
|
return $current_count;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|