diff options
Diffstat (limited to 'lib/MasterServer/UDP')
| -rwxr-xr-x | lib/MasterServer/UDP/BeaconCatcher.pm | 67 | ||||
| -rwxr-xr-x | lib/MasterServer/UDP/BeaconProcessor.pm | 120 |
2 files changed, 187 insertions, 0 deletions
diff --git a/lib/MasterServer/UDP/BeaconCatcher.pm b/lib/MasterServer/UDP/BeaconCatcher.pm new file mode 100755 index 0000000..7fdc630 --- /dev/null +++ b/lib/MasterServer/UDP/BeaconCatcher.pm @@ -0,0 +1,67 @@ + +package MasterServer::UDP::BeaconCatcher; + +use strict; +use warnings; +use AnyEvent::Handle::UDP; +use Socket qw(sockaddr_in inet_ntoa); +use Exporter 'import'; + +our @EXPORT = qw| beacon_catcher on_beacon_receive|; + +## +## Receive UDP beacons according the \heartbeat\7778\gamename\ut\ format +## where "ut" depicts the game and 7778 the query port of the game. +sub beacon_catcher { + my $self = shift; + + # module startup log + $self->log("loader","Loading UDP Beacon Catcher."); + + # UDP server + my $udp_server; + $udp_server = AnyEvent::Handle::UDP->new( + + # Bind to this host and use the port specified in the config file + bind => ['0.0.0.0', $self->{beacon_port}], + + # when datagrams are received + on_recv => sub {$self->on_beacon_receive(@_)}, + ); + + # display that the server is up and listening for beacons + $self->log("ok", "Listening for UT Beacons on port $self->{beacon_port}."); + + # allow object to exist beyond this scope. Objects have ambitions too. + return $udp_server; +} + +## process (new) beacons +sub on_beacon_receive { + # $self, beacon address, handle, packed client address + my ($self, $b, $udp, $pa) = @_; + + # unpack ip from packed client address + my ($port, $iaddr) = sockaddr_in($pa); + my $peer_addr = inet_ntoa($iaddr); + + # if the beacon has a length longer than a certain amount, assume it is + # a fraud or crash attempt + if (length $b > 64) { + # log + $self->log("attack","length exceeded in beacon: $peer_addr:$port sent $b"); + + # truncate and try to continue + $b = substr $b, 0, 64; + } + + # if a heartbeat format was detected... + $self->process_udp_beacon($udp, $pa, $b, $peer_addr, $port) + if ($b =~ m/\\heartbeat\\/ && $b =~ m/\\gamename\\/); + + # or if this is a secure response, verify the response code and add mark it verified + $self->process_udp_validate($b, $peer_addr, $port, undef) + if ($b =~ m/\\validate\\/); +} + +1; diff --git a/lib/MasterServer/UDP/BeaconProcessor.pm b/lib/MasterServer/UDP/BeaconProcessor.pm new file mode 100755 index 0000000..a41905f --- /dev/null +++ b/lib/MasterServer/UDP/BeaconProcessor.pm @@ -0,0 +1,120 @@ + +package MasterServer::UDP::BeaconProcessor; + +use strict; +use warnings; +use Data::Dumper 'Dumper'; +use AnyEvent::Handle::UDP; +use Exporter 'import'; + +our @EXPORT = qw| process_udp_beacon process_udp_validate |; + + +## process beacons that have a \heartbeat\ and \gamename\ format +sub process_udp_beacon { + # $self, handle, packed address, udp data, peer ip address, $port + my ($self, $udp, $pa, $buf, $peer_addr, $port) = @_; + + # received heartbeat in $buf: \heartbeat\7778\gamename\ut\ + my %r; + $buf =~ s/\\([^\\]+)\\([^\\]+)/$r{$1}=$2/eg; + + # check whether the beacon has a gamename that is supported in our list + if (defined $r{gamename} && exists $self->{game}->{lc $r{gamename}}) { + # log the beacon + $self->log("beacon", "$peer_addr:$r{heartbeat} for $r{gamename}"); + + # some games (like bcommander) have a default port and don't send a + # heartbeat port. + if ($r{heartbeat} == 0) { + # assuming a default port exists + if (exists $self->{game}->{lc $r{gamename}}->{port}) { + $r{heartbeat} = $self->{game}->{lc $r{gamename}}->{port}; + } + } + + # + # verify valid server address (ip+port) + if ($self->valid_address($peer_addr,$r{heartbeat})) { + + # generate a new secure string + my $secure = $self->secure_string(); + + # update beacon in serverlist if it already exists, otherwise update + # or add to pending with new secure string. + my $auth = $self->add_beacon($peer_addr, $port, $r{heartbeat}, $r{gamename}, $secure); + + # send secure string back + if ($auth > 0) { + + # verify that this is a legitimate client by sending the "secure" query + $udp->push_send("\\secure\\$secure\\final\\", $pa); + + # log this as a new beacon + $self->log("secure", "challenged new beacon $peer_addr:$port with $secure."); + } + } + + # invalid ip+port combination, like \heartbeat\0\ or local IP + else { + # Log that beacon had incorrect information, such as port 0 or so. Spams log! + $self->log("invalid","$peer_addr:$r{heartbeat} ($r{heartbeat}) had bad information"); + } + } + + # gamename not valid or not found in supportedgames.pl + else { + # log + $self->log("support", "received unknown beacon \"$r{gamename}\" from $peer_addr:$r{heartbeat}"); + } +} + + +## process the received validate query and determine whether the server is allowed in our database +sub process_udp_validate { + # $self, udp data, ip, port + my ($self, $buf, $peer_addr, $port, $heartbeat) = @_; + + # received heartbeat in $b: \validate\string\queryid\99.9\ + my %r; + $buf =~ s/\\([^\\]+)\\([^\\]+)/$r{$1}=$2/eg; + + # get our existing knowledge about this server from the database + # if the heartbeat/queryport known? then use that instead as beacon ports --> may vary after server restarts! + my $pending = (defined $heartbeat) ? $self->get_pending_info($peer_addr, $heartbeat) : $self->get_pending_beacon($peer_addr, $port); + + # if indeed in the pending list, check + if (defined $pending) { + + #determine if it uses any enctype + my $enc = (defined $r{enctype}) ? $r{enctype} : 0; + + # database may not contain the correct gamename (ucc applet, incomplete beacon, change of gameserver) + $pending->[4] = (defined $r{gamename} && exists $self->{game}->{lc $r{gamename}}) ? $r{gamename} : $pending->[4]; + + # verify challenge gamename secure enctype validate_response + my $val = $self->validated_beacon($pending->[4], $pending->[5], $enc, $r{validate}); + + # log challenge results + $self->log("secure", "$peer_addr:$port validated with $val for $pending->[4]"); + + # if validated, add to db + if ($val > 0) { + + # successfully added? ip, query port, gamename + my $sa = $self->add_to_serverlist($pending->[1], $pending->[3], $pending->[4]); + + # remove the entry from pending if successfully added + $self->remove_pending($pending->[0]) if ( $sa >= 0); + + # and set as direct beacon + $self->set_direct_beacon($pending->[1], $pending->[3]); + } + else { + # else failed validation + $self->log("error","beacon $peer_addr:$port failed validation for $pending->[4] (details: $pending->[5] sent, got $r{validate})"); + } + } +} + +1; |