#!/usr/bin/perl
##########################################################################
# $Id: fail2ban 150 2013-06-18 22:19:38Z mtremaine $
##########################################################################
# $Log: fail2ban,v $
#
# Revision 1.6  2014/08/11 16:07:46  yoh
# Patches from Yaroslav Halchenko to match adjusted in 0.9.x lines.
# Also reports now total number of hits (matches) along with Ban:Unban
# and relaxed regular expressions for matching any log level
#
# Revision 1.5  2008/08/18 16:07:46  mike
# Patches from Paul Gear <paul at libertysys.com> -mgt
#
# Revision 1.4  2008/06/30 23:07:51  kirk
# fixed copyright holders for files where I know who they should be
#
# Revision 1.3  2008/03/24 23:31:26  kirk
# added copyright/license notice to each script
#
# 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
#
##########################################################################

########################################################
## Copyright (c) 2008  Yaroslav Halchenko
## Covered under the included MIT/X-Consortium License:
##    http://www.opensource.org/licenses/mit-license.php
## All modifications and contributions by other persons to
## this script are assumed to have been donated to the
## Logwatch project and thus assume the above copyright
## and licensing terms.  If you want to make contributions
## under your own copyright or a different license this
## must be explicitly stated in the contribution an the
## Logwatch project reserves the right to not accept such
## contributions.  If you have made significant
## contributions to this script and want to claim
## copyright please contact logwatch-devel@lists.sourceforge.net.
#########################################################

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 @ActionsErrors = ();
my @CommandsErrors = ();
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
        ($ThisLine =~ /..,... \S+: (Fail2Ban v.* is running|Exiting|Enabled sections:)/) or
        ($ThisLine =~ /\S+\s+rollover performed on/) or
        ($ThisLine =~ /\S+\s+Connected to .* persistent database/) or
        ($ThisLine =~ /\S+\s+Jail '.*' uses .*/) or
        ($ThisLine =~ /\S+\s+Initiated '.*' backend/) or
        ($ThisLine =~ /\S+\s+Jail .* is not a JournalFilter instance/) or
        ($ThisLine =~ /\S+\s+Log rotation detected for/) or
        ($ThisLine =~ /\S+\s+Jail.+(?:stopped|started|uses poller)/) or
        ($ThisLine =~ /\S+\s+Changed logging target to/) or
        ($ThisLine =~ /\S+\s+Creating new jail/) or
        ($ThisLine =~ /..,... \S+\s*: INFO\s+(Set |Socket|Exiting|Gamin|Created|Added|Using)/) or # syntax of 0.7.? fail2ban
        ($ThisLine =~ /..,... \S+: Verbose level is /) or
        ($ThisLine =~ /..,... \S+: Restoring firewall rules/)
       )
   {
      if ( $Debug >= 6 ) {
         print STDERR "DEBUG($DebugCounter): line ignored\n";
      }
   } elsif ( my ($LogLevel,$Service,$Action,$Host) = ($ThisLine =~ m/(WARNING|NOTICE):?\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)"}{$Action}++;
   } elsif ( my ($LogLevel,$Service,$Host) = ($ThisLine =~ m/(INFO|WARNING|NOTICE):?\s+\[?(.*?)[]:]?\sFound[^\.]* (\S+)/)) {
      if ( $Debug >= 6 ) {
         print STDERR "DEBUG($DebugCounter): Found hit for $Service from $Host\n";
      }
      $ServicesBans{$Service}{$Host}{"Hit"}++;
      $ServicesBans{$Service}{"(all)"}{"Hit"}++;
   } elsif ( my ($Service,$Host,$NumFailures) = ($ThisLine =~ m/\S+:\s+(\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/ \S+:\s(.*):\s(\S+)\salready in ban list/)) {
      $ServicesBans{$Service}{$Host}{'AlreadyInTheList'}++;
   } elsif ( my ($Service,$Host) = ($ThisLine =~ m/\S+:?\s+\[?([^[]*?)[]:]?\s+(\S+)\salready banned/)) {
      if ( $Debug >= 6 ) {
         print STDERR "DEBUG($DebugCounter): Found hit for already banned $Host against $Service\n";
      }
      $ServicesBans{$Service}{$Host}{'AlreadyInTheList'}++;
   } elsif ( my ($Service,$Host) = ($ThisLine =~ m/ \S+:\s(.*):\sReBan (\S+)/)) {
      $ServicesBans{$Service}{$Host}{'ReBan'}++;
   } elsif ($ThisLine =~ / ERROR:?\s*(Execution of command )?\'?iptables/) {
      push @ActionsErrors, "$ThisLine\n";
   } elsif ($ThisLine =~ / ERROR\s*Failed to execute.*action/) {
      push @ActionsErrors, "$ThisLine\n";
   } elsif ($ThisLine =~ / WARNING Command \[.*\] has failed. Received/) {
      push @CommandsErrors, "$ThisLine\n";
   } elsif ($ThisLine =~ /ERROR.*returned \d+$/) {
      push @ActionsErrors, "$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:Hits\n");
    foreach my $service (sort {$a cmp $b} keys %ServicesBans) {
        printf("  %-55s [%3d:%d:%-3d]\n", "$service:",
               $ServicesBans{$service}{'(all)'}{'Ban'},
               $ServicesBans{$service}{'(all)'}{'Unban'},
               $ServicesBans{$service}{'(all)'}{'Hit'});
        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:%d:%-3d\n",
                      $name,
                      $ServicesBans{$service}{$ip}{'Ban'},
                      $ServicesBans{$service}{$ip}{'Unban'},
                      $ServicesBans{$service}{$ip}{'Hit'});
               if (($Detail >= 10) and ($ServicesBans{$service}{$ip}{'Failures'}>0)) {
                  print "      Failed ";
                  foreach my $fails (@{$ServicesBans{$service}{$ip}{'Failures'}}) {
                     print " $fails";
                  }
                  print " times\n";
               }
               if ($ServicesBans{$service}{$ip}{'AlreadyInTheList'}>0) {
                  printf("      %d Duplicate Ban attempt(s)\n", $ServicesBans{$service}{$ip}{'AlreadyInTheList'}) ;
               }
               if ($ServicesBans{$service}{$ip}{'ReBan'}>0) {
                  printf("      %d ReBan(s) due to rules reinitilizations\n", $ServicesBans{$service}{$ip}{'ReBan'}) ;
               }
            }
        }
    }
}

if ($Detail>0) {
    if ($#ActionsErrors >= 0) {
       printf("\n%d faulty action invocation(s)", $#ActionsErrors+1);
       if ($Detail > 5) {
          print ":\n";
          print @ActionsErrors ;
       }
    }
    if ($#CommandsErrors >= 0) {
       printf("\n%d faulty command invocation(s) from client(s)", $#CommandsErrors+1);
       if ($Detail > 5) {
          print ":\n";
          print @CommandsErrors ;
       }
    }
    if ($ReInitializations > 0) {
       printf("\n%d fail2ban rules reinitialization(s)", $ReInitializations);
    }
    if ($#OtherList >= 0) {
       print "\n**Unmatched Entries**\n";
       print @OtherList;
    }
}

exit(0);

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