# RBN-Telnet-Filter/Server
#
# Connects to the Reverse Beacon Network telnet feed (or any other Skimmer
# telnet feed, if desired) and provides a telnet server which only distributes
# filtered spots.
#
# Originally developed for the FOC Marathon 2011, but it may be useful for all
# kind of clubs or contests, that's why I released the source code into the
# public domain. Feel free to do whatever you want with it.
#
# Contact: Fabian Kurz, DJ1YFK <fabian@fkurz.net>
# URL:     http://fkurz.net/ham/stuff.html?rbnfilter
#
# members.txt = plain text file with all calls that are not filtered out
#
# Before you use this, make sure you set your callsign here:

$mycall = "N0CALL";

# This program should run on all machines that have a reasonably recent version
# of Perl installed. 

use strict;
use warnings;
use threads;
use threads::shared;
use Thread::Queue;
use IO::Socket::INET;
use Net::Telnet ();

$| =  1;

my $listener = IO::Socket::INET->new(
		LocalPort => 7300,
		Listen => 32768,
		Reuse => 1,
		Timeout => 172800) 
	|| die "Cannot create socket\n"; 

my $client;
my $client_num = 0;

my @thr;
my @thr_cmd;
my @dat : shared;

my %callhash : shared;
my %callcount;

# Calls that will pass the spot filter
open CALLS, "members.txt";
while (my $a = <CALLS>) {
	chomp($a);
	$callhash{$a} = 1;
}
close CALLS;

open STAT, "spotstats.txt";
<STAT>;
while (my $a = <STAT>) {
	my @tmp = split(/\s+/, $a);
	$callcount{$tmp[0]} = $tmp[1];
}
close STAT;

# This thread connects to the RBN and receives / redistributes spots
my $feedthread = threads->new(\&rbn);

my $line : shared;
while (1)  {
	$client = $listener->accept;
	$client_num++;
	push(@dat, Thread::Queue->new);
	$thr[$client_num] = threads->create(\&start_thread_out, $client, $client_num);
	$thr_cmd[$client_num] = threads->create(\&start_thread_in, $client, $client_num);
}


sub start_thread_out {
	threads->self->detach();
	my ($client, $client_num) = @_;
	my $command;
	print "thread out created for client $client_num\n";
	print $client "Callsign: ";
	my $clientcall;
	$client->recv($clientcall, 700000);
	$clientcall = uc($clientcall);
	$clientcall =~ s/[^a-zA-Z0-9-]//g;
	print $client "Hello $clientcall !\r\n\r\n";
	print $client "Welcome to the filtered RBN feed of FUBAR ARC.\r\n";
	print $client "http://fkurz.net/ham/stuff.html#rbnfilter\r\n\r\n";
	print "User: $clientcall\n";
	open LOG, ">>log";
	my $date = `date`;
	print LOG "$date $clientcall\n";
	close LOG;
	while (1) {
		my $data = $dat[$client_num-1]->dequeue;
		if ($client->connected) {
			print $client $data;
		}
		else {
			print "Client $client_num disappeared\n";
			open LOG, ">>log";
			my $date = `date`;
			print LOG "$date $clientcall OUT\n";
			close LOG;
			last;
		}
	}
}

sub start_thread_in {
	threads->self->detach();
	my ($client, $client_num) = @_;
	my $command;
	print "thread in created for client $client_num\n";
	my $cmd;
	while (1) {
		sleep 1;
		$client->recv($cmd, 700000);
		if ($cmd =~ /set\/member ([a-z0-9\/]+)/i) {
			my $newcall = uc($1);
			open LOG, ">>members.txt";
			print LOG "$newcall\n";
			close LOG;
			print $client "Added $newcall to the member database.\r\n";
			$callhash{$newcall} = 1;
		}
	}
	print "input dead $client_num\n";
}



sub rbn {
	threads->self->detach();
	my @lines;
	print "rbn: connecting\n";
	my $t = new Net::Telnet (Timeout => 30, Port => 7000, Prompt => '/./');
	$t->open("telnet.reversebeacon.net");
	$t->print("$mycall\n");
	$t->print("set/nobell\n");
	print @lines;

	while (1) {
		$line = $t->getline(Timeout => 1000);
		if (!$line) {
			print "RBN feed died!\n";
			exit;
	 	}

		next unless ($line =~ /^DX/);

		my $c = substr($line, 28, 10);
		$c =~ s#[^A-Z0-9/]##g;

		if ($callhash{$c}) {
			print "Member:\n";
			$callcount{$c}++;
			save_callcount();
			foreach (@dat) {
				$_->enqueue($line."\r");
			}
		}
		print $line;
	 }

}



sub save_callcount () {
	open STAT, ">spotstats.txt";
	print STAT "RBN statistics (started 2011-02-22 22:00z)\r\n";
	foreach (sort keys %callcount) {
			if ($callcount{$_}) {
				print STAT "$_ \t $callcount{$_}\r\n";
			}
	}
	close STAT;
}