diff options
Diffstat (limited to 'examples/historical/mbd/mbd.pl')
| -rw-r--r-- | examples/historical/mbd/mbd.pl | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/examples/historical/mbd/mbd.pl b/examples/historical/mbd/mbd.pl new file mode 100644 index 0000000..065e76c --- /dev/null +++ b/examples/historical/mbd/mbd.pl @@ -0,0 +1,254 @@ +#! /usr/bin/perl +use strict; +use warnings; +use Socket; +use Net::CIDR; +use Net::RawIP; +use Time::HiRes; +require './access_list.pl'; +require './nets.pl'; +require './survey.pl'; +require './mbd.pm'; +use lib '../include'; +use nms; +use strict; +use warnings; + +# Mark packets with DSCP CS7 +my $tos = 56; + +my ($dbh, $q); + +sub fhbits { + my $bits = 0; + for my $fh (@_) { + vec($bits, fileno($fh), 1) = 1; + } + return $bits; +} + +# used for rate limiting +my %last_sent = (); + +# for own surveying +my %active_surveys = (); +my %last_survey = (); + +my %cidrcache = (); +sub cache_cidrlookup { + my ($addr, $net) = @_; + my $key = $addr . " " . $net; + + if (!exists($cidrcache{$key})) { + $cidrcache{$key} = Net::CIDR::cidrlookup($addr, $net); + } + return $cidrcache{$key}; +} + +my %rangecache = (); +sub cache_cidrrange { + my ($net) = @_; + + if (!exists($rangecache{$net})) { + ($rangecache{$net}) = Net::CIDR::cidr2range($net); + } + + return $rangecache{$net}; +} + +open LOG, ">>", "mbd.log"; + +my @ports = ( mbd::find_all_ports() , $Config::survey_port_low .. $Config::survey_port_high ); + +# Open a socket for each port +my @socks = (); +my $udp = getprotobyname("udp"); +for my $p (@ports) { + my $sock; + socket($sock, PF_INET, SOCK_DGRAM, $udp); + bind($sock, sockaddr_in($p, INADDR_ANY)); + push @socks, $sock; +} + +my $sendsock = Net::RawIP->new({udp => {}}); + +print "Listening on " . scalar @ports . " ports.\n"; + +# Main loop +while (1) { + my $rin = fhbits(@socks); + my $rout; + + my $nfound = select($rout=$rin, undef, undef, undef); + my $now = [Time::HiRes::gettimeofday]; + + # First of all, close any surveys that are due. + for my $sport (keys %active_surveys) { + my $age = Time::HiRes::tv_interval($active_surveys{$sport}{start}, $now); + if ($age > $Config::survey_time && $active_surveys{$sport}{active}) { + my $hexdump = join(' ', map { sprintf "0x%02x", ord($_) } (split //, $active_surveys{$sport}{data})); + print "Survey ($hexdump) for '" . $Config::access_list[$active_surveys{$sport}{entry}]->{name} . "'/" . + $active_surveys{$sport}{dport} . ": " . $active_surveys{$sport}{num} . " active servers.\n"; + $active_surveys{$sport}{active} = 0; + + # (re)connect to the database if needed + if (!defined($dbh) || !$dbh->ping) { + $dbh = nms::db_connect(); + $q = $dbh->prepare("INSERT INTO mbd_log (ts,game,port,description,active_servers) VALUES (CURRENT_TIMESTAMP,?,?,?,?)") + or die "Couldn't prepare query"; + } + $q->execute($active_surveys{$sport}{entry}, $active_surveys{$sport}{dport}, $Config::access_list[$active_surveys{$sport}{entry}]->{name}, $active_surveys{$sport}{num}); + } + if ($age > $Config::survey_time * 3.0) { + delete $active_surveys{$sport}; + } + } + + for my $sock (@socks) { + next unless (vec($rout, fileno($sock), 1) == 1); + + my $data; + my $addr = recv($sock, $data, 8192, 0); # jumbo broadcast! :-P + my ($sport, $saddr) = sockaddr_in($addr); + my ($dport, $daddr) = sockaddr_in(getsockname($sock)); + my $size = length($data); + + # Check if this is a survey reply + if ($dport >= $Config::survey_port_low && $dport <= $Config::survey_port_high) { + if (!exists($active_surveys{$dport})) { + print "WARNING: Unknown survey port $dport, ignoring\n"; + next; + } + if (!$active_surveys{$dport}{active}) { + # remains + next; + } + + ++$active_surveys{$dport}{num}; + + next; + } + + # Rate limiting + if (exists($last_sent{$saddr}{$dport})) { + my $elapsed = Time::HiRes::tv_interval($last_sent{$saddr}{$dport}, $now); + if ($elapsed < 1.0) { + print LOG "$dport $size 2\n"; + print inet_ntoa($saddr), ", $dport, $size bytes => rate-limited ($elapsed secs since last)\n"; + next; + } + } + + # We don't get the packet's destination address, but I guess this should do... + # Check against the ACL. + my $pass = 0; + my $entry = -1; + for my $rule (@Config::access_list) { + ++$entry; + + next unless (mbd::match_ranges($dport, $rule->{'ports'})); + next unless (mbd::match_ranges($size, $rule->{'sizes'})); + + if ($rule->{'filter'}) { + next unless ($rule->{'filter'}($data)); + } + + $pass = 1; + last; + } + + print LOG "$dport $size $pass\n"; + + if (!$pass) { + print inet_ntoa($saddr), ", $dport, $size bytes => filtered\n"; + next; + } + + $last_sent{$saddr}{$dport} = $now; + + # The packet is OK! Do we already have a recent enough survey + # for this port, or should we use this packet? + my $survey = 1; + if (exists($last_survey{$entry . "/" . $dport})) { + my $age = Time::HiRes::tv_interval($last_survey{$entry . "/" . $dport}, $now); + if ($age < $Config::survey_freq) { + $survey = 0; + } + } + + # New survey; find an unused port + my $survey_sport; + if ($survey) { + for my $port ($Config::survey_port_low..$Config::survey_port_high) { + if (!exists($active_surveys{$port})) { + $survey_sport = $port; + + $active_surveys{$port} = { + start => $now, + active => 1, + dport => $dport, + entry => $entry, + num => 0, + data => $data, + }; + $last_survey{$entry . "/" . $dport} = $now; + + last; + } + } + + if (!defined($survey_sport)) { + print "WARNING: no free survey source ports, not surveying.\n"; + $survey = 0; + } + } + + my $num_nets = 0; + for my $net (@Config::networks) { + my ($range) = cache_cidrrange($net); + $range =~ /-(.*?)$/; + my $broadcast = $1; + + if ($survey) { + $sendsock->set({ + ip => { + saddr => $Config::survey_ip, + daddr => $broadcast, + tos => $tos + }, + udp => { + source => $survey_sport, + dest => $dport, + data => $data + } + }); + $sendsock->send; + } + + next if (cache_cidrlookup(inet_ntoa($saddr), $net)); + + $sendsock->set({ + ip => { + saddr => inet_ntoa($saddr), + daddr => $broadcast, + tos => $tos + }, + udp => { + source => $sport, + dest => $dport, + data => $data + } + }); + $sendsock->send; + + ++$num_nets; + } + + if ($survey) { + print inet_ntoa($saddr), ", $dport, $size bytes => ($num_nets networks) [+survey from port $survey_sport]\n"; + } else { + print inet_ntoa($saddr), ", $dport, $size bytes => ($num_nets networks)\n"; + } + } +} + |