contrib/ipfilter/perl/logfilter.pl

   1 #!perl.exe
   2
   3 # Author: Chris Grant
   4 # Copyright 1999, Codetalker Communications, Inc.
   5 #
   6 # This script takes a firewall log and breaks it into several
   7 # different files. Each file is named based on the service that
   8 # runs on the port that was recognized in log line. After
   9 # this script has run, you should end up with several files.
  10 # Of course you will have the original log file and then files
  11 # such as web.log, telnet.log, pop3.log, imap.log, backorifice.log,
  12 # netbus.log, and unknown.log.
  13 #
  14 # The number of entries in unknown.log should be minimal. The
  15 # mappings of the port numbers and file names are stored in the bottom
  16 # of this file in the data section. Simply look at the ports being hit,
  17 # find out what these ports do, and add them to the data section.
  18 #
  19 # You may be wondering why I haven't simply parsed RFC1700 to come up
  20 # with a list of port numbers and files. The reason is that I don't
  21 # believe reading firewall logs should be all that automated. You
  22 # should be familiar with what probes are hitting your system. By
  23 # manually adding entries to the data section this ensures that I
  24 # have at least educated myself about what this protocol is, what
  25 # the potential exposure is, and why you might be seeing this traffic.
  26
  27 %icmp = ();
  28 %udp = ();
  29 %tcp = ();
  30 %openfiles = ();
  31 $TIDBITSFILE = "unknown.log";
  32
  33 # Read the ports data from the end of this file and build the three hashes
  34 while (<DATA>) {
  35     chomp;                                # trim the newline
  36     s/#.*//;                              # no comments
  37     s/^\s+//;                             # no leading white
  38     s/\s+$//;                             # no trailing white
  39     next unless length;                   # anything left?
  40     $_ = lc;                              # switch to lowercase
  41     ($proto, $identifier, $filename) = m/(\S+)\s+(\S+)\s+(\S+)/;
  42     SWITCH: {
  43         if ($proto =~ m/^icmp$/) { $icmp{$identifier} = $filename; last SWITCH; };
  44         if ($proto =~ m/^udp$/) { $udp{$identifier} = $filename; last SWITCH; };
  45         if ($proto =~ m/^tcp$/) { $tcp{$identifier} = $filename; last SWITCH; };
  46         die "An unknown protocol listed in the proto defs\n$_\n";
  47     }
  48 }
  49
  50 $filename = shift;
  51 unless (defined($filename)) { die "Usage: logfilter.pl <log file>\n"; }
  52 open(LOGFILE, $filename) || die "Could not open the firewall log file.\n";
  53 $openfiles{$filename} = "LOGFILE";
  54
  55 $linenum = 0;
  56 while($line = <LOGFILE>) {
  57
  58     chomp($line);
  59     $linenum++;
  60
  61     # determine the protocol - send to unknown.log if not found
  62     SWITCH: {
  63
  64         ($line =~ m /\sicmp\s/) && do {
  65
  66             #
  67             # ICMP Protocol
  68             #
  69             # Extract the icmp packet information specifying the type.
  70             #
  71             # Note: Must check for ICMP first because this may be an ICMP reply
  72             #       to a TCP or UDP connection (eg Port Unreachable).
  73
  74             ($icmptype) = $line =~ m/icmp (\d+)\/\d+/;
  75
  76             $filename = $TIDBITSFILE;
  77             $filename = $icmp{$icmptype} if (defined($icmp{$icmptype}));
  78
  79             last SWITCH;
  80           };
  81
  82         ($line =~ m /\stcp\s/) && do {
  83
  84             #
  85             # TCP Protocol
  86             #
  87             # extract the source and destination ports and compare them to
  88             # known ports in the tcp hash. For the first match, place this
  89             # line in the file specified by the tcp hash. Ignore one of the
  90             # port matches if both ports happen to be known services.
  91
  92             ($sport, $dport) = $line =~ m/\d+\.\d+\.\d+\.\d+,(\d+) -> \d+\.\d+\.\d+\.\d+,(\d+)/;
  93             #print "$line\n" unless (defined($sport) && defined($dport));
  94
  95             $filename = $TIDBITSFILE;
  96             $filename = $tcp{$sport} if (defined($tcp{$sport}));
  97             $filename = $tcp{$dport} if (defined($tcp{$dport}));
  98
  99             last SWITCH;
 100           };
 101
 102         ($line =~ m /\sudp\s/) && do {
 103
 104             #
 105             # UDP Protocol - same procedure as with TCP, different hash
 106             #
 107
 108             ($sport, $dport) = $line =~ m/\d+\.\d+\.\d+\.\d+,(\d+) -> \d+\.\d+\.\d+\.\d+,(\d+)/;
 109
 110             $filename = $TIDBITSFILE;
 111             $filename = $udp{$sport} if (defined($udp{$sport}));
 112             $filename = $udp{$dport} if (defined($udp{$dport}));
 113
 114             last SWITCH;
 115           };
 116
 117         #
 118         # The default case is that the protocol was unknown
 119         #
 120         $filename = $TIDBITSFILE;
 121     }
 122
 123     #
 124     # write the line to the appropriate file as determined above
 125     #
 126     # check for filename in the openfiles hash. if it exists then write
 127     # to the given handle. otherwise open a handle to the file and add
 128     # it to the hash of open files.
 129
 130     if (defined($openfiles{$filename})) {
 131         $handle = $openfiles{$filename};
 132     } else {
 133         $handle = "HANDLE" . keys %openfiles;
 134         open ($handle, ">>".$filename) || die "Couldn't open|create the file $filename";
 135         $openfiles{$filename} = $handle;
 136     }
 137     print $handle "#$linenum\t $line\n";
 138
 139 }
 140
 141 # close all open file handles
 142
 143 foreach $key (keys %openfiles) {
 144     close($openfiles{$key});
 145 }
 146
 147 close(LOGFILE);
 148
 149 __DATA__
 150 icmp    3         destunreach.log
 151 icmp    8         ping.log
 152 icmp    9         router.log
 153 icmp    10        router.log
 154 icmp    11        ttl.log
 155 tcp     23        telnet.log
 156 tcp     25        smtp.log
 157 udp     25        smtp.log
 158 udp     53        dns.log
 159 tcp     80        http.log
 160 tcp     110       pop3.log
 161 tcp     111       rpc.log
 162 udp     111       rpc.log
 163 tcp     137       netbios.log
 164 udp     137       netbios.log
 165 tcp     143       imap.log
 166 udp     161       snmp.log
 167 udp     370       backweb.log
 168 udp     371       backweb.log
 169 tcp     443       https.log
 170 udp     443       https.log
 171 udp     512       syslog.log
 172 tcp     635       nfs.log           # NFS mount services
 173 udp     635       nfs.log           # NFS mount services
 174 tcp     1080      socks.log
 175 udp     1080      socks.log
 176 tcp     6112      games.log         # Battle net
 177 tcp     6667      irc.log
 178 tcp     7070      realaudio.log
 179 tcp     8080      http.log
 180 tcp     12345     netbus.log
 181 udp     31337     backorifice.log