CityGuide jam service emulator (incomplete)

cityguide-jam-service-emulator.pl

#!/usr/bin/perl

use IO::Socket;
use IO::Socket::INET;
use Sys::Syslog;
use Sys::Syslog qw(:DEFAULT setlogsock);
use Sys::Syslog qw(:standard :macros);
use Time::Local;

setlogsock("console");
openlog("pbotd", "cons,pid", LOG_USER);


my $sock = new IO::Socket::INET ( LocalHost => '0.0.0.0', LocalPort => '1961', Proto => 'tcp',  Listen => 1, Reuse => 1 ); die "Could not create socket: $!\n" unless $sock;

while (my ($client,$clientaddr) = $sock->accept()) {
 
 write_log("Connected from ".$client->peerhost());
 $pid = fork();
 
 die "Cannot fork: $!" unless defined($pid);
 
 if ($pid == 0) { 
        # Child process
		my $data = '';
		
		# Client protocol detection
		$client->recv($data,4);
		
		my $cproto = $data;
		
		write_log($client->peerhost() . " proto = '$cproto'");
		
		if ($cproto =~ /DK(01|03|04|05)/) {
		 # generating crypto key
		 my $R = int(rand(255));
		 $R = 1 if $R == 0;
		 write_log($client->peerhost() . " crypto key = $R (0x" . sprintf("%02x",$R) . ")");
		 $client->send(pack('c',$R));
		 
		 # getting program signature
		 $client->recv($data,4);
		 
		 # error count
		 my $errorcount = 0;
		 
		 my $progsign = unpack('i',$data);
	 
		 write_log($client->peerhost() . " program sign = ".$progsign . " (0x" . sprintf("%02x",$progsign) .")");
		 
		 $client->recv($data,3);
		 
		 my $loginsign = $data;
		 
		 # validating login signature
		 $errorcount++ if ($loginsign ne pack('ccc',$R^0xFF,$R^0xFF^0x01,$R^0xFF));
		 
		 write_log($client->peerhost() . " login sign = 0x".unpack('H*',$data));
		
		 $client->recv($data,1);
		 
		 my $loginlen = unpack('C',$data)^$R;
		 
		 # validating login length
		 $errorcount++ if ($loginlen == 0);
		 
		 write_log($client->peerhost() . " login length = $loginlen");
		 
		 $client->recv($data, $loginlen * 2);
		 
		 my @logindata = unpack('C*',$data);
		 
		 my $login = '';
		 
		 
		 
		 for (my $i=0 ; $logindata[$i] ; $i++) {
		  my $loginchar = $logindata[$i]^$R;
		  # validating login data
		  $errorcount++ if ($i % 2 == 1 and $logindata[$i] ne $R);
		  $login .= chr($loginchar) if $loginchar != 0;
		 }
		  
		 write_log($client->peerhost() . " login = '$login'");
		 

		$client->recv($data,3);
		 
		my $passsign = $data;
		
		# validating password signature
		$errorcount++ if ($passsign ne pack('ccc',$R^0xFF,$R^0xFF^0x01,$R^0xFF));
		 
		write_log($client->peerhost() . " pass sign = 0x".unpack('H*',$data));
		
		 $client->recv($data,1);
		 
		 my $passlen = unpack('C',$data)^$R;

		 # validating password length
		 $errorcount++ if ($passlen == 0);
		 
		 write_log($client->peerhost() . " pass length = $passlen");
		 
		 
		 $client->recv($data, $passlen * 2);
		 
		 my @passdata = unpack('C*',$data);
		 
		 my $pass = '';
		 
		 for (my $i=0 ; $passdata[$i] ; $i++) {
		  my $passchar = $passdata[$i]^$R;
		  # validating password data
		  $errorcount++ if ($i % 2 == 1 and $passdata[$i] ne $R);
		  $pass .= chr($passchar) if $passchar != 0;
		 }
		  
		 write_log($client->peerhost() . " pass = '$pass'");
		 
		 $client->recv($data,1);
		 
		 my $unknown1 = unpack('C',$data)^$R;
		 
		 write_log($client->peerhost() . " unknown1 = $unknown1 (0x".sprintf('%02x',$unknown1).")");
		 
		 $client->recv($data,1);
		 
		 my $unknown2 = unpack('C',$data)^$R;
		 
		 write_log($client->peerhost() . " unknown2 = $unknown2 (0x".sprintf('%02x',$unknown2).")");
		 
		 $client->recv($data,2);
		 
		 my $logincheck = $data;
		 
		 # final validating login packet
		 $errorcount++ if ($logincheck ne pack('cc',$R,$R));

		 write_log($client->peerhost() . " login check = 0x".unpack('H*',$logincheck));
		 
		 write_log($client->peerhost() . " error counter = ".sprintf('%d',$errorcount));
		 
		 if ($login && $pass && $errorcount == 0) {
			# login successful
			$client->send(pack('S',0x1));
			
			write_log($client->peerhost() . " Client $login authenticated");
			
			# client command processing
			
			 while (1) {
				my $mapname = '';
				
				if ($cproto =~ /DK0[3|4|5]/) {
					$client->recv($data,5);
					my($tmp,$mapnamelen)=unpack('iC', $data);
				
					write_log($client->peerhost() . " map name length = $mapnamelen");
				
					$client->recv($data, $mapnamelen * 2);
				
					my @mapnamedata = unpack('C*',$data);
				
				
				
					for my $mapnamechar (@mapnamedata) {
						$mapname .= chr($mapnamechar) if $mapnamechar != 0;
					}
				
					write_log($client->peerhost() . " map name = $mapname");
				
				}

				my $mapver = 0;
				if ($cproto =~ /DK0[4|5]/) {
				 $client->recv($data,2);
				 $mapver = unpack('S',$data); 
				}

				write_log($client->peerhost() . " map version = " . sprintf('%d', $mapver));
				
				
				
				### temp ###
				my $updatesavailable = 1;
				
				if ($updatesavailable) {
					$client->send(pack('S',0x03)); #updates available
					
					$client->recv($data,2);
					my $clientcmd = unpack('S',$data); 
					
					#temp 
					my $updfilename = '78SPb.jam';
					
					
					
					#got start updates command
					if ($clientcmd == 0x02) {
					
						my $updfilesize = -s $updfilename;
						
						# updsize = size(namelen1)+size(name1)+12 + 4 + updfilesize1 + size(namelen2)+size(name2)+ 12 + 4 + updfilesize2 ...
						my $updsize  = 1 + length($updfilename) + 12 + 4 + $updfilesize;
						
						
						write_log($client->peerhost() . " update filesize = " . sprintf('%d', $updfilesize));
						
						# send summary updates size
						$client->send(pack('I',$updsize));
						
						# send filename length
						$client->send(pack('C',length($updfilename)));
						
						# send update filename
						$client->send(pack('a*',$updfilename));
						
						#send unknown 4-byte data
						$client->send(pack('I',0x8000000a));
						
						
						my ($min,$hour,$mday,$mon,$year) = (gmtime(time))[1,2,3,4,5];
						my $timestamp = timelocal(31,$min,$hour,$mday,$mon,$year);
						
						#send update timestamp
						$client->send(pack('I',$timestamp));
						
						#send unknown 4-byte data
						$client->send(pack('I',0x00000000));
						
						# send update file size
						$client->send(pack('I',$updfilesize));
						
						#send update
						open(UPDFILE, $updfilename);
						while (sysread(UPDFILE, $data, 1)) {
						
						
						 $client->send(pack("C",unpack("C",$data)));
						}
						close(UPDFILE);
						
						$client->recv($data,2);
						$clientcmd = unpack('S',$data); 
						
						$client->send(pack('S',0x05)); #no updates found code
						
						exit(0);
						
					}
					
				
				} else {
					$client->send(pack('S',0x05)); #no updates found code
				}
				
			
			}
			
		 } else {
		    write_log($client->peerhost() . " Authentication failed for $login");
			$client->send(pack('S',0x7)); #auth failure code
		 }
		 
		}
		
		
		
        exit(0);   # Child process exits when it is done.
 } # else 'tis the parent process, which goes back to accept()

}
close($sock);

sub write_log() {
 #syslog('info', $_[0]);
 my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)=localtime(time());
 my $timestamp = sprintf("%02d.%02d.%4d %02d:%02d:%02d",$mday,$mon+1,$year+1900,$hour,$min,$sec);
 
 print "$timestamp pbotd[] " . $_[0] ."\n";
 
}