/usr/sbin/p0f-analyzer is in amavisd-new 1:2.7.1-2ubuntu3.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
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 | #!/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:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * 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.
# * Neither the name of the author, nor the name of the "Jozef Stefan"
# Institute, nor the names of contributors may be used to endorse or
# promote products derived from this software without specific prior
# written permission.
#
# 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 license above is the new 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);
$VERSION = '1.400';
# Example usage:
# p0f -i bge0 -l 'tcp dst port 25' 2>&1 | p0f-analyzer.pl 2345
#
# In the p0f filter expression above specify an IP address of this host where
# your MTA is listening for incoming mail, in place of host.example.com above.
# Match the UDP port number (like 2345 above) with the port to which a client
# will be sending queries ($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;
}
|