receive UDP beacons, validate them and store with country indicator

1 files changed, 67 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;