dns-flood-detector/dns_flood_collector.pl

158 lines
3.6 KiB
Perl
Executable file

#!/usr/bin/perl
use strict;
use threads;
use threads::shared;
use Sys::Syslog;
use Data::Dumper;
use Getopt::Long;
use POSIX;
use IO::Socket::Multicast;
use JSON;
# Native Maxmind library - http://www.maxmind.com/download/geoip/api/perl/
# requires: http://www.maxmind.com/app/c
use Geo::IP;
# set these to the same port and multicast (or unicast) address as the detector
use constant GROUP => '226.1.1.2';
use constant PORT => '2000';
my %ipc_source :shared;
my %ipc_customer :shared;
my $time_to_die :shared = 0;
my $debug;
my $foreground=0;
# determines how often you want to aggregage and write-out stats dumps
my $interval = 60;
# you can get the binary format GeoLiteCity.dat from Maxmind
# http://www.maxmind.com/app/geolitecity
my $gi = Geo::IP->open("/usr/local/GeoLiteCity.dat",GEOIP_MEMORY_CACHE | GEOIP_CHECK_CACHE);
# adjust this to the path where you want to keep the
sub PATH {'/tmp/'}
$|=1;
GetOptions(
"debug" => \$debug,
"foreground" => \$foreground,
"interval=s" => \$interval,
);
main();
exit();
sub main() {
# daemonize unless running in foreground
unless ($foreground){
daemonize();
}
# prepare data acquisition thread
threads->new(\&get_data);
while (! $time_to_die ) {
# record time started to help evenly space runs
my $start_run = time();
my $next_run = $start_run + $interval;
# de-serialize latest copy of source address structure
# execute this in a isolated scope so that lock goes out of scope
{
my $source_distance;
# lock data structure to prevent other thread from updating it
lock(%ipc_source);
# open coordinates file for graph generation
open(CRDS, ">".PATH."/coords.txt.tmp");
# calculate great circle distance between each source IP and local POP
foreach my $key (keys %ipc_source) {
eval {
my $r = $gi->record_by_addr($key);
# write raw entry to coordinates file
print CRDS $key.",".$ipc_source{$key}.",".$r->latitude.",".$r->longitude."\n";
};
if ($@) {
print CRDS $key.",".$ipc_source{$key}.",0,0\n";
}
}
# close coordinate file
close CRDS;
system("mv ".PATH."/coords.txt.tmp ".PATH."/coords.txt");
# clean out structure for next sample period
%ipc_source = ();
}
# sleep to make the interval
while((my $time_left = ($next_run - time())) > 0) {
sleep($time_left);
}
}
threads->join();
return;
}
# fetch data from UDP multicast
sub get_data() {
# set up our multicast listener
# note: this will receive unicast fine too
my $sock = IO::Socket::Multicast->new(LocalPort=>PORT,ReuseAddr=>1);
$sock->mcast_add(GROUP) || die "Couldn't set group: $!\n";
while ( ! $time_to_die ) {
my $data;
next unless $sock->recv($data,1500);
# decode JSON
eval {
my $obj = decode_json $data;
print Dumper $obj;
foreach my $ip (keys %{$obj->{data}}) {
my $count = $obj->{data}->{$ip};
lock(%ipc_source);
$ipc_source{$ip}+=$count;
}
};
}
# done!
threads->exit();
}
# daemonize application
sub daemonize {
chdir '/' or die "Can't chdir to /: $!";
open STDIN, '/dev/null' or die "Can't read /dev/null: $!";
open STDOUT, '>/dev/null';
# fork and exit parent
my $pid = fork();
exit if $pid;
die "Couldn't fork: $!" unless defined ($pid);
POSIX::setsid() || die ("$0 can't start a new session: $!");
open STDERR, '>&STDOUT' or die "Can't dup stdout: $!";
# signal handlers
$SIG{KILL} = \&handler;
}
sub handler {
$time_to_die = 1;
}