##########################################################################
# $Id: fail2ban,v 1.2 2006/12/15 04:53:59 bjorn Exp $
##########################################################################
# $Log: fail2ban,v $
# Revision 1.2  2006/12/15 04:53:59  bjorn
# Additional filtering, by Willi Mann.
#
# Revision 1.1  2006/05/30 19:04:26  bjorn
# Added fail2ban service, written by Yaroslav Halchenko.
#
# 
# Written by Yaroslav Halchenko <debian@onerussian.com> for fail2ban
#
##########################################################################

use strict;
use Logwatch ':all';

my $Debug = $ENV{'LOGWATCH_DEBUG'} || 0;
my $Detail = $ENV{'LOGWATCH_DETAIL_LEVEL'} || 0;
my $IgnoreHost = $ENV{'sshd_ignore_host'} || "";
my $DebugCounter = 0;
my $ReInitializations = 0;
my @IptablesErrors = ();
my $NotValidIP = 0;		# reported invalid IPs number
my @OtherList = ();

my %ServicesBans = ();

if ( $Debug >= 5 ) {
	print STDERR "\n\nDEBUG: Inside Fail2Ban Filter \n\n";
	$DebugCounter = 1;
}

while (defined(my $ThisLine = <STDIN>)) {
    if ( $Debug >= 5 ) {
	print STDERR "DEBUG($DebugCounter): $ThisLine";
	$DebugCounter++;
    }
    chomp($ThisLine);
    if ( ($ThisLine =~ /..,... DEBUG: /) or
	 ($ThisLine =~ /..,... \S*\s*: DEBUG /) or # syntax of 0.7.? fail2ban
	 ($ThisLine =~ /..,... INFO: (Fail2Ban v.* is running|Exiting|Enabled sections:)/) or
	 ($ThisLine =~ /..,... \S+\s*: INFO\s+(Set |Socket|Exiting|Gamin|Created|Added|Using)/) or # syntax of 0.7.? fail2ban
	 ($ThisLine =~ /..,... WARNING: Verbose level is /) or
	 ($ThisLine =~ /..,... WARNING: Restoring firewall rules/)
	 )
    {
	if ( $Debug >= 6 ) {
	    print STDERR "DEBUG($DebugCounter): line ignored\n";
	}
    } elsif ( my ($Service,$Action,$Host) = ($ThisLine =~ m/WARNING:?\s\[?(.*?)[]:]?\s(Ban|Unban)[^\.]* (\S+)/)) {
	if ( $Debug >= 6 ) {
	    print STDERR "DEBUG($DebugCounter): Found $Action for $Service from $Host\n";
	}
	$ServicesBans{$Service}{$Host}{$Action}++;
	$ServicesBans{$Service}{"(all)"}{$Action}++;
    } elsif ( my ($Service,$Host,$NumFailures) = ($ThisLine =~ m/INFO: (\S+): (.+) has (\d+) login failure\(s\). Banned./)) {
	if ($Debug >= 4) {
	    print STDERR "DEBUG: Found host $Host trying to access $Service - failed $NumFailures times\n";
	}
	push @{$ServicesBans{$Service}{$Host}{'Failures'}}, $NumFailures;
    } elsif ( my ($Service,$Host) = ($ThisLine =~ m/ ERROR:\s(.*):\s(\S+)\salready in ban list/)) {
	$ServicesBans{$Service}{$Host}{'AlreadyInTheList'}++;
    } elsif ( my ($Service,$Host) = ($ThisLine =~ m/ WARNING:\s(.*):\sReBan (\S+)/)) {
	$ServicesBans{$Service}{$Host}{'ReBan'}++;
    } elsif ($ThisLine =~ / ERROR:?\s*(Execution of command )?\'?iptables/) {
	push @IptablesErrors, "$ThisLine\n";
    } elsif (($ThisLine =~ /..,... WARNING: \#\S+ reinitialization of firewalls/) or
	     ($ThisLine =~ / ERROR\s*Invariant check failed. Trying to restore a sane environment/)) {
	$ReInitializations++;
    } elsif ($ThisLine =~ /..,... WARNING:  is not a valid IP address/) {
	# just ignore - this will be fixed within fail2ban and is harmless warning
    }
    else
    {
	# Report any unmatched entries...
	push @OtherList, "$ThisLine\n";
    }
}

###########################################################


if (keys %ServicesBans) {
    printf("\nBanned services with Fail2Ban:				 Bans:Unbans\n");
    foreach my $service (sort {$a cmp $b} keys %ServicesBans) {
	printf("   %-55s [%3d:%-3d]\n", "$service:",
	       $ServicesBans{$service}{'(all)'}{'Ban'},
	       $ServicesBans{$service}{'(all)'}{'Unban'});
	delete $ServicesBans{$service}{'(all)'};
	my $totalSort = TotalCountOrder(%{$ServicesBans{$service}}, \&SortIP);
	if ($Detail >= 5) {
	    foreach my $ip (sort $totalSort keys %{$ServicesBans{$service}}) {
		my $name = LookupIP($ip);
		printf("      %-53s %3d:%-3d\n",
		       $name,
		       $ServicesBans{$service}{$ip}{'Ban'},
		       $ServicesBans{$service}{$ip}{'Unban'});
		if (($Detail >= 10) and ($ServicesBans{$service}{$ip}{'Failures'}>0)) {
		    print "	   Failed ";
		    foreach my $fails (@{$ServicesBans{$service}{$ip}{'Failures'}}) {
			print " $fails";
		    }
		    print " times";
		    printf("\n	   %d Duplicate Ban attempts", $ServicesBans{$service}{$ip}{'AlreadyInTheList'}) ;
		    printf("\n	   %d ReBans due to rules reinitilizations", $ServicesBans{$service}{$ip}{'ReBan'}) ;
		    print "\n";
		}
	    }
	}
    }
}


if ($Detail>0) {
    if ($#IptablesErrors > 0) {
	printf("\n%d faulty iptables invocation(s)", $#IptablesErrors);
	if ($Detail > 5) {
	    print ":\n";
	    print @IptablesErrors ;
	}
    }
    if ($ReInitializations > 0) {
	printf("\n%d fail2ban rules reinitialization(s)", $ReInitializations);
    }
    if ($#OtherList >= 0) {
	print "\n**Unmatched Entries**\n";
	print @OtherList;
    }
}

exit(0);

# vi: shiftwidth=3 tabstop=3 syntax=perl et