File: p0f-analyzer.pl-old

package info (click to toggle)
amavisd-new 1%3A2.11.0-6.1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 12,432 kB
  • sloc: perl: 33,770; sh: 523; sql: 158; makefile: 8
file content (269 lines) | stat: -rwxr-xr-x 11,264 bytes parent folder | download | duplicates (5)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
#!/usr/bin/perl -T

#------------------------------------------------------------------------------
# This is p0f-analyzer.pl, a program to continuously read log reports from p0f
# utility, keep results in cache for a couple of minutes, and answer queries
# over UDP from some program (like amavisd-new) about collected data.
#
# Author: Mark Martinec <Mark.Martinec@ijs.si>
#
# Copyright (c) 2006, Mark Martinec
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright notice,
#    this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# The views and conclusions contained in the software and documentation are
# those of the authors and should not be interpreted as representing official
# policies, either expressed or implied, of the Jozef Stefan Institute.

# (the above license is the 2-clause BSD license, also known as
#  a "Simplified BSD License", and pertains to this program only)
#
# Patches and problem reports are welcome.
# The latest version of this program is available at:
#   http://www.ijs.si/software/amavisd/
#------------------------------------------------------------------------------

  use strict;
  use re 'taint';
  use Errno qw(EAGAIN EINTR);
  use Socket;
  use vars qw($VERSION);
  $VERSION = '1.401';

# Example usage:
#   p0f -i bge0 -l 'tcp dst port 25' 2>&1 | p0f-analyzer.pl 2345
#
# In the p0f filter expression above specify an IP address of this host where
# your MTA is listening for incoming mail, in place of host.example.com above.
# Match the UDP port number (like 2345 above) with the port to which a client
# will be sending queries ($os_fingerprint_method in amavisd.conf).

  # argument should be a free UDP port where queries will be accepted on
  $ARGV[0] =~ /^[0-9]+\z/  or die <<'EOD';
Specify a valid UDP port as an argument.

Usage:
  p0f-analyzer.pl <udp-port>

Example usage:
  p0f -l 'tcp dst port 25' 2>&1 | p0f-analyzer.pl 2345
EOD

  my($port) = untaint($ARGV[0]);

# my($bind_addr) = '0.0.0.0';       # bind to all IPv4 interfaces
  my($bind_addr) = '127.0.0.1';     # bind just to a loopback interface

  my(@inet_acl) = qw( 127.0.0.1 );  # list of IP addresses from which queries
                                    # will be accepted, others are ignored
  my($retention_time) = 10*60;    # time to keep collected information in cache
  my($debug) = 0;                   # nonzero enables log messages to STDERR

  do_log(1, "p0f-analyzer version %s starting", $VERSION);
  do_log(1, "listening on UDP port %s, allowed queries from: %s",
            $port, join(", ",@inet_acl));
  socket(S, PF_INET, SOCK_DGRAM, getprotobyname('udp')) or die "socket: $!";

  my($packed_addr);
  $packed_addr = inet_aton($bind_addr)
    or die "inet_aton: bad IP address [$bind_addr]: $!";
  bind(S, sockaddr_in($port,$packed_addr))
    or die "binding to [$bind_addr] failed: $!";
  my($fn_sock) = fileno(S); my($fn_stdin) = fileno(STDIN);
  my($rin,$rout); $rin = '';
  vec($rin,$fn_sock,1) = 1; vec($rin,$fn_stdin,1) = 1;
  my(%src); my($cnt_since_cleanup) = 0;
  binmode(STDIN)  or die "Can't set STDIN binmode: $!";
  for (;;) {
    my($nfound,$timeleft) = select($rout=$rin, undef, undef, undef);
    my($now) = time;
    if (vec($rout,$fn_sock,1)) {
      my($port,$iaddr,$paddr,$clientaddr); my($inbuf);
      $paddr = recv(S,$inbuf,64,0);
      if (!defined($paddr)) {
        if ($!==EAGAIN || $!==EINTR) {
          # false alarm, nothing can be read
        } else {
          die "recv: $!";
        }
      } else {
        ($port,$iaddr) = sockaddr_in($paddr)  if $paddr ne '';
        $clientaddr = inet_ntoa($iaddr)  if defined $iaddr;
        if (!defined($clientaddr)) {
          do_log(1, "query from unknown client");
        } elsif (!grep {$_ eq $clientaddr} @inet_acl) {
          do_log(1, "query from non-approved client: %s:%s",$clientaddr,$port);
        } elsif ($port < 1024 || $port == 2049 || $port > 65535) {
          do_log(1, "query from questionable port: %s:%s",  $clientaddr,$port);
        } elsif ($inbuf !~ /^([^ ]+) (.*)$/s) {
          do_log(1, "invalid query syntax from %s:%s", $clientaddr,$port);
        } else {
          my($query,$nonce) = ($1,$2);  my($src_ip,$src_port);
          if ($query =~ /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\z/s) {
            $src_ip = $query; $src_port = 0;  # old style query
          } elsif ($query =~ /^ \[ ([^\]]*) \] (?: : (\d{1,5}) )? \z/xs) {
            $src_ip = $1; $src_port = $2;
            if ($src_ip =~ /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\z/) {
              # IPv4
            } elsif ($src_ip =~ /^
                       (?: (?: IPv6: )? 0{0,4} (?: : 0{0,4} ){1,4} : FFFF : )?
                       ( \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3} )\z/xsi) {
              $src_ip = $1;  # IPv4-mapped IPv6 address, alternative dec, form
            } elsif ($src_ip =~ /^ (?: IPv6: )?
                                   [0-9a-f]{0,4} (?: : [0-9a-f]{0,4} ){2,7}
                                 \z/xsi) {
              $src_ip =~ s/^IPv6://i;
            } elsif ($src_ip =~ /^ (?: IPv6: )?
                                   [0-9a-f]{0,4} (?: : [0-9a-f]{0,4} ){2,5} :
                                   \d{1,3} (?: \. \d{1,3} ){3} \z/xsi) {
              $src_ip =~ s/^IPv6://i;
            } else { undef $src_ip }
          }
          $src_port = 0  if !defined($src_port);
          if (length($nonce) > 1024) {
            do_log(1, "invalid query from %s:%s, nonce too long: %d chrs",
                      $clientaddr,$port,length($nonce));
          } elsif ($nonce !~ /^([\040-\177].*)\z/s) {
            do_log(1, "invalid query from %s:%s, forbidden char in nonce",
                      $clientaddr,$port);
          } elsif (!defined($src_ip) || $src_port > 65535) {
            do_log(1, "invalid query from %s:%s, bad IP address or port: %s",
                      $clientaddr,$port,$query);
          } else {
            do_log(1, "query from  %s:%s: %s", $clientaddr,$port,$inbuf);
            my($resp) = '';
            if (exists($src{$src_ip})) {
              if ($src_port > 0) {  # source port known, must match exactly
                $resp = $src{"[$src_ip]:$src_port"}{d}
                  if exists $src{"[$src_ip]:$src_port"};
              } else {  # source port not known, find the closest match
                for my $e (@{$src{$src_ip}}) {
                  if ($resp eq '') { $resp = $e->{d} }
                  elsif ($e->{d} eq $resp) {}
                  else {  # keep the longest common string head
                    my($j);  my($resp_l) = length($resp);
                    for ($j=0; $j<$resp_l; $j++)
                      { last  if substr($e->{d},$j,1) ne substr($resp,$j,1) }
                    if ($j < $resp_l) {
#                     do_log(1, "TRUNCATED to %d: %s %s => /%s/",
#                               $j, $resp, $e->{d}, substr($resp,0,$j));
                      $resp = substr($resp,0,$j);
                    }
                  }
                  last;
                }
              }
            }
            $resp = $query.' '.$nonce.' '.$resp;
            do_log(1, "response to %s:%s: %s", $clientaddr,$port,$resp);
            defined(send(S, $resp."\015\012", 0, $paddr)) or die "send: $!";
          }
        }
      }
    }
    if (vec($rout,$fn_stdin,1)) {
      $cnt_since_cleanup++; my($line); $! = 0;
      my($nbytes) = sysread(STDIN,$line,1024);
      if (!defined($nbytes)) {
        if ($!==EAGAIN || $!==EINTR) {
          # false alarm, nothing can be read
        } else {
          die "Read: $!";
        }
      } elsif ($nbytes < 1) {  # sysread returns 0 at eof
        last;  # eof
      } else {
        chomp($line);
        local($1,$2,$3,$4,$5,$6);
        $line =~ /^(\d+\.\d+\.\d+\.\d+):(\d+)[ -]*(.*)
                   \ ->\ (\d+\.\d+\.\d+\.\d+):(\d+)\s*(.*)$/x or next;
        my($src_ip,$src_port,$src_t,$dst_ip,$dst_port,$src_d) =
          ($1,$2,$3,$4,$5,$6);
        my($descr) = "$src_t, $src_d";
        my($entry) = { t=>$now, p=>$src_port, c=>1, d=>$descr };
        $src{"[$src_ip]:$src_port"} = $entry;
        if (!exists($src{$src_ip})) {
          do_log(2, "first: [%s]:%s %.70s", $src_ip,$src_port,$descr);
          $src{$src_ip} = [ $entry ];
        } else {
          my($found) = 0;
          for my $e (@{$src{$src_ip}}) {
            if ($e->{d} eq $descr) {
              $e->{c}++; $e->{p} = '*'; $e->{t} = $now, $found = 1;
              do_log(2, "deja-vu: [%s]:%s, cnt=%d %.70s",
                        $src_ip,$src_port,$e->{c},$descr);
              last;
            }
          }
          if (!$found) {
            push(@{$src{$src_ip}}, $entry);
            do_log(2, "stored: [%s]:%d %.70s", $src_ip,$src_port,$descr);
          }
        }
      }
      if ($cnt_since_cleanup > 50) {
        for my $k (keys %src) {
          if (ref($src{$k}) ne 'ARRAY') {
            if ($src{$k}{t} + $retention_time < $now) {
              do_log(2, "EXPIRED: %s, age = %d s", $k, $now - $src{$k}{t});
              delete $src{$k};
            }
          } else {
            my(@kept) = grep { $_->{t} + $retention_time >= $now } @{$src{$k}};
            if (!@kept) {
              do_log(2, "EXPIRED: %s, age = %d s", $k, $now - $src{$k}[0]{t});
              delete $src{$k};
            } elsif (@kept != @{$src{$k}}) {
              do_log(2, "SHRUNK: %s, %d -> %d",
                        $k, scalar(@{$src{$k}}), scalar(@kept));
              @{$src{$k}} = @kept;
            }
          }
        }
        $cnt_since_cleanup = 0;
      }
    }
  }
  do_log(1, "normal termination");
  exit 0;

# Return untainted copy of a string (argument can be a string or a string ref)
sub untaint($) {
  no re 'taint';
  my($str);
  if (defined($_[0])) {
    local($1); # avoid Perl taint bug: tainted global $1 propagates taintedness
    $str = $1  if (ref($_[0]) ? ${$_[0]} : $_[0]) =~ /^(.*)\z/s;
  }
  $str;
}

# write log entry
sub do_log($$;@) {
  my($level,$errmsg,@args) = @_;
  if ($level <= $debug) {
    $errmsg = sprintf($errmsg,@args)  if @args;
    print STDERR $errmsg,"\n";
  }
  1;
}