#!/usr/bin/perl
#===============================================================================
#
#         FILE:  gosa-server
#
#        USAGE:  gosa-si-client
#
#  DESCRIPTION:
#
#      OPTIONS:  ---
# REQUIREMENTS:  libnetaddr-ip-perl
#         BUGS:  ---
#        NOTES:
#       AUTHOR:   (Andreas Rettenberger), <rettenberger@gonicus.de>
#      COMPANY:
#      VERSION:  1.0
#      CREATED:  12.09.2007 08:54:41 CEST
#     REVISION:  ---
#===============================================================================

use strict;
use warnings;
use Getopt::Long;
use Config::IniFiles;
use POSIX;

use POE qw(Component::Server::TCP);
use IO::Socket::INET;
use NetAddr::IP;
use Data::Dumper;
use Crypt::Rijndael;
use GOSA::GosaSupportDaemon;
use Digest::MD5  qw(md5_hex);
use MIME::Base64;
use XML::Simple;
#use Fcntl;
#use Sys::Syslog qw( :DEFAULT setlogsock);
#use File::Spec;
#use Cwd;

my $event_dir = "/usr/lib/gosa-si/client/events";
use lib "/usr/lib/gosa-si/client/events";



my ($cfg_file, %cfg_defaults, $foreground, $verbose, $pid_file, $procid, $pid, $log_file);
my ($server_ip, $server_port, $server_key, $server_timeout, $server_domain);
my ($client_ip, $client_port, $ldap_enabled, $ldap_config, $pam_config, $nss_config);

# default variables
my $server_address;
my @servers;
my $client_address;
my $client_mac_address;
my $xml;
my $default_server_key;
my $event_hash;

%cfg_defaults = (
"general" =>
    {"log_file" => [\$log_file, "/var/run/".$0.".log"],
    "pid_file" => [\$pid_file, "/var/run/".$0.".pid"],
    },
"client" => 
    {"client_port" => [\$client_port, "20083"],
     "client_ip" => [\$client_ip, "0.0.0.0"],
     "ldap" => [\$ldap_enabled, 1],
     "ldap_config" => [\$ldap_config, "/etc/ldap/ldap.conf"],
     "pam_config" => [\$pam_config, "/etc/pam_ldap.conf"],
     "nss_config" => [\$nss_config, "/etc/libnss_ldap.conf"],
    },
"server" =>
    {"server_ip" => [\$server_ip, "127.0.0.1"],
    "server_port" => [\$server_port, "20081"],
    "server_key" => [\$server_key, ""],
    "server_timeout" => [\$server_timeout, 10],
    "server_domain" => [\$server_domain, ""],
    },

);


#=== FUNCTIONS = functions =====================================================

#===  FUNCTION  ================================================================
#         NAME: check_cmdline_param
#   PARAMETERS: 
#      RETURNS:  
#  DESCRIPTION: 
#===============================================================================
sub check_cmdline_param () {
    my $err_config;
    my $err_counter = 0;
	if(not defined($cfg_file)) {
		$cfg_file = "/etc/gosa-si/client.conf";
		if(! -r $cfg_file) {
			$err_config = "please specify a config file";
			$err_counter += 1;
		}
    }
    if( $err_counter > 0 ) {
        &usage( "", 1 );
        if( defined( $err_config)) { print STDERR "$err_config\n"}
        print STDERR "\n";
        exit( -1 );
    }
}


#===  FUNCTION  ================================================================
#         NAME:  read_configfile
#   PARAMETERS:  cfg_file - string - 
#      RETURNS:  
#  DESCRIPTION: 
#===============================================================================
sub read_configfile {
    my $cfg;
    if( defined( $cfg_file) && ( length($cfg_file) > 0 )) {
        if( -r $cfg_file ) {
            $cfg = Config::IniFiles->new( -file => $cfg_file );
        } else {
            print STDERR "Couldn't read config file!";
        }
    } else {
        $cfg = Config::IniFiles->new() ;
    }
    foreach my $section (keys %cfg_defaults) {
        foreach my $param (keys %{$cfg_defaults{ $section }}) {
            my $pinfo = $cfg_defaults{ $section }{ $param };
            ${@$pinfo[ 0 ]} = $cfg->val( $section, $param, @$pinfo[ 1 ] );
        }
    }
}


#===  FUNCTION  ================================================================
#         NAME: check_pid
#   PARAMETERS:
#      RETURNS:
#  DESCRIPTION:
#===============================================================================
sub check_pid {
    $pid = -1;
    # Check, if we are already running
    if( open(LOCK_FILE, "<$pid_file") ) {
        $pid = <LOCK_FILE>;
        if( defined $pid ) {
            chomp( $pid );
            if( -f "/proc/$pid/stat" ) {
                my($stat) = `cat /proc/$pid/stat` =~ m/$pid \((.+)\).*/;
                if( $0 eq $stat ) {
                    close( LOCK_FILE );
                    exit -1;
                }
            }
        }
        close( LOCK_FILE );
        unlink( $pid_file );
    }

    # create a syslog msg if it is not to possible to open PID file
    if (not sysopen(LOCK_FILE, $pid_file, O_WRONLY|O_CREAT|O_EXCL, 0644)) {
        my($msg) = "Couldn't obtain lockfile '$pid_file' ";
        if (open(LOCK_FILE, '<', $pid_file)
                && ($pid = <LOCK_FILE>))
        {
            chomp($pid);
            $msg .= "(PID $pid)\n";
        } else {
            $msg .= "(unable to read PID)\n";
        }
        if( ! ($foreground) ) {
            openlog( $0, "cons,pid", "daemon" );
            syslog( "warning", $msg );
            closelog();
        }
        else {
            print( STDERR " $msg " );
        }
        exit( -1 );
    }
}


#===  FUNCTION  ================================================================
#         NAME:  logging
#   PARAMETERS:  level - string - default 'info' 
#                msg - string - 
#                facility - string - default 'LOG_DAEMON' 
#      RETURNS:  
#  DESCRIPTION: 
#===============================================================================
sub daemon_log {
    # log into log_file
    my( $msg, $level ) = @_;
    if(not defined $msg) { return }
    if(not defined $level) { $level = 1 }
    if(defined $log_file){
        open(LOG_HANDLE, ">>$log_file");
        if(not defined open( LOG_HANDLE, ">>$log_file" )) {
            print STDERR "cannot open $log_file: $!";
            return }
            chomp($msg);
            if($level <= $verbose){
                my ($seconds, $minutes, $hours, $monthday, $month,
                        $year, $weekday, $yearday, $sommertime) = localtime(time);
                $hours = $hours < 10 ? $hours = "0".$hours : $hours;
                $minutes = $minutes < 10 ? $minutes = "0".$minutes : $minutes;
                $seconds = $seconds < 10 ? $seconds = "0".$seconds : $seconds;
                my @monthnames = ("Jan", "Feb", "Mar", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");
                $month = $monthnames[$month];
                $monthday = $monthday < 10 ? $monthday = "0".$monthday : $monthday;
                $year+=1900;
                my $name = $0;
                $name =~ s/\.\///;

                my $log_msg = "$month $monthday $hours:$minutes:$seconds $name $msg\n";
                print LOG_HANDLE $log_msg;
                if( $foreground ) { 
                    print STDERR $log_msg;
                }
            }
        close( LOG_HANDLE );
    }
#log into syslog
#    my ($msg, $level, $facility) = @_;
#    if(not defined $msg) {return}
#    if(not defined $level) {$level = "info"}
#    if(not defined $facility) {$facility = "LOG_DAEMON"}
#    openlog($0, "pid,cons,", $facility);
#    syslog($level, $msg);
#    closelog;
#    return;
}


#===  FUNCTION  ================================================================
#         NAME:  get_interfaces 
#   PARAMETERS:  none
#      RETURNS:  (list of interfaces) 
#  DESCRIPTION:  Uses proc fs (/proc/net/dev) to get list of interfaces.
#===============================================================================
sub get_interfaces {
    my @result;
    my $PROC_NET_DEV= ('/proc/net/dev');

    open(PROC_NET_DEV, "<$PROC_NET_DEV")
        or die "Could not open $PROC_NET_DEV";

    my @ifs = <PROC_NET_DEV>;

    close(PROC_NET_DEV);

    # Eat first two line
    shift @ifs;
    shift @ifs;

    chomp @ifs;
    foreach my $line(@ifs) {
        my $if= (split /:/, $line)[0];
        $if =~ s/^\s+//;
        push @result, $if;
    }

    return @result;
}

#===  FUNCTION  ================================================================
#         NAME:  get_mac 
#   PARAMETERS:  interface name (i.e. eth0)
#      RETURNS:  (mac address) 
#  DESCRIPTION:  Uses ioctl to get mac address directly from system.
#===============================================================================
sub get_mac {
    my $ifreq= shift;
    my $result;
    if ($ifreq && length($ifreq) > 0) { 
        if($ifreq eq "all") {
            if(defined($server_ip)) {
                $result = &get_local_mac_for_remote_ip($server_ip);
            } else {
                $result = "00:00:00:00:00:00";
            }
        } else {
            my $SIOCGIFHWADDR= 0x8927;     # man 2 ioctl_list

                # A configured MAC Address should always override a guessed value
                if ($client_mac_address and length($client_mac_address) > 0) {
                    $result= $client_mac_address;
                }

            socket SOCKET, PF_INET, SOCK_DGRAM, getprotobyname('ip')
                or die "socket: $!";

            if(ioctl SOCKET, $SIOCGIFHWADDR, $ifreq) {
                my ($if, $mac)= unpack 'h36 H12', $ifreq;

                if (length($mac) > 0) {
                    $mac=~ m/^([0-9a-f][0-9a-f])([0-9a-f][0-9a-f])([0-9a-f][0-9a-f])([0-9a-f][0-9a-f])([0-9a-f][0-9a-f])([0-9a-f][0-9a-f])$/;
                    $mac= sprintf("%s:%s:%s:%s:%s:%s", $1, $2, $3, $4, $5, $6);
                    $result = $mac;
                }
            }
        }
    }
    return $result;
}


#===  FUNCTION  ================================================================
#         NAME:  get_interface_for_ip
#   PARAMETERS:  ip address (i.e. 192.168.0.1)
#      RETURNS:  array: list of interfaces if ip=0.0.0.0, matching interface if found, undef else
#  DESCRIPTION:  Uses proc fs (/proc/net/dev) to get list of interfaces.
#===============================================================================
sub get_interface_for_ip {
    my $result;
    my $ip= shift;
    if ($ip && length($ip) > 0) {
        my @ifs= &get_interfaces();
        if($ip eq "0.0.0.0") {
            $result = "all";
        } else {
            foreach (@ifs) {
                my $if=$_;
                if(get_ip($if) eq $ip) {
                    $result = $if;
                    last;
                }
            }       
        }
    }       
    return $result;
}


#===  FUNCTION  ================================================================
#         NAME:  get_ip 
#   PARAMETERS:  interface name (i.e. eth0)
#      RETURNS:  (ip address) 
#  DESCRIPTION:  Uses ioctl to get ip address directly from system.
#===============================================================================
sub get_ip {
    my $ifreq= shift;
    my $result= "";
    my $SIOCGIFADDR= 0x8915;       # man 2 ioctl_list
        my $proto= getprotobyname('ip');

    socket SOCKET, PF_INET, SOCK_DGRAM, $proto
        or die "socket: $!";

    if(ioctl SOCKET, $SIOCGIFADDR, $ifreq) {
        my ($if, $sin)    = unpack 'a16 a16', $ifreq;
        my ($port, $addr) = sockaddr_in $sin;
        my $ip            = inet_ntoa $addr;

        if ($ip && length($ip) > 0) {
            $result = $ip;
        }
    }

    return $result;
}


#===  FUNCTION  ================================================================
#         NAME:  get_local_mac_for_remote_ip
#   PARAMETERS:  none (takes server_ip from global variable)
#      RETURNS:  (ip address from interface that is used for communication) 
#  DESCRIPTION:  Uses ioctl to get routing table from system, checks which entry
#                matches (defaultroute last).
#===============================================================================
sub get_local_mac_for_remote_ip {
    my $ifreq= shift;
    my $result= "00:00:00:00:00:00";
    my $PROC_NET_ROUTE= ('/proc/net/route');

    open(PROC_NET_ROUTE, "<$PROC_NET_ROUTE")
        or die "Could not open $PROC_NET_ROUTE";

    my @ifs = <PROC_NET_ROUTE>;

    close(PROC_NET_ROUTE);

    # Eat header line
    shift @ifs;
    chomp @ifs;
    foreach my $line(@ifs) {
        my ($Iface,$Destination,$Gateway,$Flags,$RefCnt,$Use,$Metric,$Mask,$MTU,$Window,$IRTT)=split(/\s/, $line);
        my $destination;
        my $mask;
        my ($d,$c,$b,$a)=unpack('a2 a2 a2 a2', $Destination);
        $destination= sprintf("%d.%d.%d.%d", hex($a), hex($b), hex($c), hex($d));
        ($d,$c,$b,$a)=unpack('a2 a2 a2 a2', $Mask);
        $mask= sprintf("%d.%d.%d.%d", hex($a), hex($b), hex($c), hex($d));
        if(new NetAddr::IP($server_ip)->within(new NetAddr::IP($destination, $mask))) {
            # destination matches route, save mac and exit
            $result= &get_mac($Iface);
            last;
        }
    }


    return $result;
}


sub create_passwd {
    my $new_passwd = "";
    for(my $i=0; $i<31; $i++) {
        $new_passwd .= ("a".."z","A".."Z",0..9)[int(rand(62))]
    }

    return $new_passwd;
}


sub get_server_addresses {
    my $domain= shift;
    my @result;
    my $dig_cmd= 'dig +nocomments srv _gosad._tcp.'.$domain;

    my $output= `$dig_cmd 2>&1`;
    open (PIPE, "$dig_cmd 2>&1 |");
    while(<PIPE>) {
        chomp $_;
        # If it's not a comment
        if($_ =~ m/^[^;]/) {
            my @matches= split /\s+/;

            # Push hostname with port
            if($matches[3] eq 'SRV') {
                push @result, $matches[7].':'.$matches[6];
            } elsif ($matches[3] eq 'A') {
                my $i=0;

                # Substitute the hostname with the ip address of the matching A record
                foreach my $host (@result) {
                    if ((split /\:/, $host)[0] eq $matches[0]) {
                        $result[$i]= $matches[4].':'.(split /\:/, $host)[1];
                    }
                    $i++;
                }
            }
        }
    }
    close(PIPE);
    return @result;
}


##===  FUNCTION  ================================================================
##         NAME:  create_ciphering
##   PARAMETERS:  passwd - string - used to create ciphering
##      RETURNS:  cipher - object
##  DESCRIPTION:  creates a Crypt::Rijndael::MODE_CBC object with passwd as key
##===============================================================================
#sub create_ciphering {
#    my ($passwd) = @_;
#    $passwd = substr(md5_hex("$passwd") x 32, 0, 32);
#    my $iv = substr(md5_hex('GONICUS GmbH'),0, 16);
#
#    #daemon_log("iv: $iv", 7);
#    #daemon_log("key: $passwd", 7);
#    my $my_cipher = Crypt::Rijndael->new($passwd , Crypt::Rijndael::MODE_CBC());
#    $my_cipher->set_iv($iv);
#    return $my_cipher;
#}
#
#
#sub create_ciphering {
#    my ($passwd) = @_;
#    $passwd = substr(md5_hex("$passwd") x 32, 0, 32);
#    my $iv = substr(md5_hex('GONICUS GmbH'),0, 16);
#    my $my_cipher = Crypt::Rijndael->new($passwd , Crypt::Rijndael::MODE_CBC());
#    $my_cipher->set_iv($iv);
#    return $my_cipher;
#}
#
#
#sub encrypt_msg {
#    my ($msg, $key) = @_;
#    my $my_cipher = &create_ciphering($key);
#    {
#      use bytes;
#      $msg = "\0"x(16-length($msg)%16).$msg;
#    }
#    $msg = $my_cipher->encrypt($msg);
#    chomp($msg = &encode_base64($msg));
#    # there are no newlines allowed inside msg
#    $msg=~ s/\n//g;
#    return $msg;
#}
#
#
#sub decrypt_msg {
#    my ($msg, $key) = @_ ;
#    $msg = &decode_base64($msg);
#    my $my_cipher = &create_ciphering($key);
#    $msg = $my_cipher->decrypt($msg); 
#    $msg =~ s/\0*//g;
#    return $msg;
#}


#===  FUNCTION  ================================================================
#         NAME:  send_msg_hash2address
#   PARAMETERS:  msg_hash - hash - xml_hash created with function create_xml_hash
#                PeerAddr string - socket address to send msg
#                PeerPort string - socket port, if not included in socket address
#      RETURNS:  nothing
#  DESCRIPTION:  ????
#===============================================================================
sub send_msg_hash2address {
    my ($msg_hash, $address, $passwd) = @_ ;

    # fetch header for logging
    my $header = @{$msg_hash->{header}}[0];  

    # generate xml string
    my $msg_xml = &create_xml_string($msg_hash);
    
    # encrypt xml msg
    my $crypted_msg = &encrypt_msg($msg_xml, $passwd);

    # opensocket
    my $socket = &open_socket($address);
    if(not defined $socket){
        daemon_log("cannot send '$header'-msg to $address , server not reachable", 5);
        return 1;
    }
    
    # send xml msg
    print $socket $crypted_msg."\n";
    
    close $socket;

    daemon_log("send '$header'-msg to $address", 1);
    daemon_log("message:\n$msg_xml", 8);
    return 0;
}


sub open_socket {
    my ($PeerAddr, $PeerPort) = @_ ;
    if(defined($PeerPort)){
        $PeerAddr = $PeerAddr.":".$PeerPort;
    }
    my $socket;
    $socket = new IO::Socket::INET(PeerAddr => $PeerAddr,
            Porto => "tcp",
            Type => SOCK_STREAM,
            Timeout => 5,
            );
    if(not defined $socket) {
        return;
    }
    &daemon_log("open_socket: $PeerAddr", 7);
    return $socket;
}


#===  FUNCTION  ================================================================
#         NAME:  register_at_server
#   PARAMETERS:  
#      RETURNS:  
#  DESCRIPTION:  
#===============================================================================
sub register_at_gosa_si_server {

    # create new passwd and ciphering object for client-server communication
    $server_key = &create_passwd();

#    # detect all client accepted events
#    opendir(DIR, $event_dir) 
#        or daemon_log("cannot find directory $event_dir!\ngosa-si-client starts without any accepting events!", 1);
#    my $file_name;
#    my @events_list = ();
#    my $events;
#    while(defined($file_name = readdir(DIR))){
#        if ($file_name eq "." || $file_name eq "..") {
#            next;
#        }
#        push(@events_list, $file_name);
#    }
#    if( 0 == @events_list ) {
#        $events = "none";
#    }
#    else {  
#        $events = join(",", @events_list);
#    }
#    daemon_log("events found for gosa-si-client: $events", 1);
    my $events = join( ", ", keys %{$event_hash} );

    
    while(1) {

        # fetch first gosa-si-server from @servers
        my $server = shift(@servers);

        if( !$server ) {
            daemon_log("no gosa-si-server left in list of servers", 1);
            exit(1)
        }

        # create registration msg
        my $register_hash = &create_xml_hash("here_i_am", $client_address, $server);
        &add_content2xml_hash($register_hash, "new_passwd", $server_key);
        &add_content2xml_hash($register_hash, "mac_address", $client_mac_address);
        &add_content2xml_hash($register_hash, "events", $events);

        # send xml hash to server with general server passwd
        my $res = &send_msg_hash2address($register_hash, $server, $default_server_key);
        if( $res == 1 ) {
            next;
        }

        last;
    }
    
    

#    my ($rout, $wout, $reg_server);
#    foreach my $server (@servers) {
#
#        # create msg hash
#        my $register_hash = &create_xml_hash("here_i_am", $client_address, $server);
#        &add_content2xml_hash($register_hash, "new_passwd", $new_server_key);
#        &add_content2xml_hash($register_hash, "mac_address", $client_mac_address);
#        &add_content2xml_hash($register_hash, "events", $events);
#
#        # send xml hash to server with general server passwd
#        my $answer = &send_msg_hash2address($register_hash, $server, $server_passwd);
# 
#        if ($answer != 0) { next; }
#       
#        # waiting for response
#        daemon_log("waiting for response...\n", 5);
#        my $nf = select($rout=$rbits, $wout=$wbits, undef, $server_timeout);
#
#        # something is coming in
#        if(vec $rout, fileno $input_socket, 1) {
#            my $crypted_msg;
#            my $client = $input_socket->accept();
#            my $other_end = getpeername($client);
#            if(not defined $other_end) {
#                daemon_log("client cannot be identified: $!\n");
#            } else {
#                my ($port, $iaddr) = unpack_sockaddr_in($other_end);
#                my $actual_ip = inet_ntoa($iaddr);
#                daemon_log("\naccept client from $actual_ip\n", 5);
#                my $in_msg = &read_from_socket($client);
#                if(defined $in_msg){
#                    chomp($in_msg);
#                    $crypted_msg = $in_msg;
#                } else {
#                    daemon_log("cannot read from $actual_ip\n", 5);
#                }
#            }
#            close($client);
#            
#            # validate acknowledge msg from server
#            $new_server_cipher = &create_ciphering($new_server_passwd);
#            my $msg_hash;
#            eval {
#                my $decrypted_msg = &decrypt_msg($crypted_msg, $new_server_cipher);
#                daemon_log("decrypted register msg: $decrypted_msg", 5);
#                $msg_hash = $xml->XMLin($decrypted_msg, ForceArray=>1);
#            };
#            if($@) {
#                daemon_log("ERROR: do not understand the incoming message:" , 5);  
#                daemon_log("$@", 7); 
#            } else {
#                my $header = @{$msg_hash->{header}}[0];
#                if($header eq "registered") {
#                    $reg_server = $server;
#                    last;
#                } elsif($header eq "denied") {
#                    my $reason = (&get_content_from_xml_hash($msg_hash, "denied"))[0];
#                    daemon_log("registration at $server denied: $reason", 1);
#                } else {
#                    daemon_log("cannot register at $server", 1);
#                }
#            }
#        }
#        # if no answer arrive, try next server in list
#
#    }
#    
#    if(defined $reg_server) {
#        daemon_log("registered at $reg_server", 1);
#    } else {
#        daemon_log("cannot register at any server", 1);
#        daemon_log("exiting!!!", 1);
#        exit(1);
#    }
#
#    # update the global available variables
#    $server_address = $reg_server;
#    $server_passwd = $new_server_passwd;
#    $server_cipher = $new_server_cipher;
    return;
}



sub check_key_and_xml_validity {
    my ($crypted_msg, $module_key) = @_;
#print STDERR "crypted_msg:$crypted_msg\n";
#print STDERR "modul_key:$module_key\n";

    my $msg;
    my $msg_hash;
    eval{
        $msg = &decrypt_msg($crypted_msg, $module_key);
        &main::daemon_log("decrypted_msg: \n$msg", 8);

        $msg_hash = $xml->XMLin($msg, ForceArray=>1);

        # check header
        my $header_l = $msg_hash->{'header'};
        if( 1 != @{$header_l} ) {
            die'header error';
        }
        my $header = @{$header_l}[0];
        if( 0 == length $header) {
            die 'header error';
        }

        # check source
        my $source_l = $msg_hash->{'source'};
        if( 1 != @{$source_l} ) {
            die'source error';
        }
        my $source = @{$source_l}[0];
        if( 0 == length $source) {
            die 'source error';
        }

        # check target
        my $target_l = $msg_hash->{'target'};
        if( 1 != @{$target_l} ) {
            die'target error';
        }
        my $target = @{$target_l}[0];
        if( 0 == length $target) {
            die 'target error';
        }

    };
    if($@) {
        &main::daemon_log("WARNING: do not understand the message:", 5);
        &main::daemon_log("$@", 8);
    }

    return ($msg, $msg_hash);
}


sub import_events {
    if (not -e $event_dir) {
        daemon_log("ERROR: cannot find directory or directory is not readable: $event_dir", 1);   
    }
    opendir (DIR, $event_dir) or die "ERROR while loading gosa-si-events from directory $event_dir : $!\n";

    while (defined (my $event = readdir (DIR))) {
        if( $event eq "." || $event eq ".." ) { next; }    

        eval{ require $event; };
        if( $@ ) {
            daemon_log("import of event module '$event' failed", 1);
            daemon_log("$@", 8);
            next;
        }

        $event =~ /(\S*?).pm$/;
        my $event_module = $1;
        my $events_l = eval( $1."::get_events()") ;
        foreach my $event_name (@{$events_l}) {
            print "$event_name\n";
            $event_hash->{$event_name} = $event_module;
        }

    }
}


sub server_input {
    my ($heap,$input,$wheel) = @_[HEAP, ARG0, ARG1];
    my $error = 0;
    
    daemon_log("Incoming msg:\n$input\n", 8);

    my ($msg, $msg_hash) = &check_key_and_xml_validity($input, $server_key);
    if( (!$msg) || (!$msg_hash) ) {
        daemon_log("Deciphering of incoming msg failed", 5);
        $error++;
    }

    if( $error == 0 ) {
        #print STDERR "msg:\n$msg\n";
        #print STDERR Dumper($msg_hash);

        my $header = @{$msg_hash->{header}}[0];
        my $source = @{$msg_hash->{source}}[0];
        if ($header eq 'new_ldap_config') { if ($ldap_enabled == 1) {&new_ldap_config($msg_hash)}}
        elsif ($header eq 'ping') { &got_ping($msg_hash) }
        elsif ($header eq 'wake_up') { &execute_event($msg_hash)}
        elsif ($header eq 'new_passwd') { &new_passwd()}
        elsif ($header eq 'compute_hardware') { &compute_hardware() }
        elsif ($header eq 'registered') { daemon_log("gosa-si-client registerd at $source", 1) }
        else { daemon_log("ERROR: no function assigned to msg $header", 5) }

    }
    return;
}

#==== MAIN = main ==============================================================
#  parse commandline options
Getopt::Long::Configure( "bundling" );
GetOptions("h|help" => \&usage,
           "c|config=s" => \$cfg_file,
           "f|foreground" => \$foreground,
           "v|verbose+" => \$verbose,
           );

#  read and set config parameters
&check_cmdline_param ;
&read_configfile;
&check_pid;


# forward error messages to logfile
if ( ! $foreground ) {
	open STDIN, '/dev/null' or die "Can’t read /dev/null: $!";
	open STDOUT, '>>/dev/null' or die "Can't write to /dev/null: $!";
	open STDERR, '>>/dev/null' or die "Can't write to /dev/null: $!";
}

# Just fork, if we are not in foreground mode
if( ! $foreground ) { 
    chdir '/'                 or die "Can't chdir to /: $!";
    $pid = fork;
    setsid                    or die "Can't start a new session: $!";
    umask 0;
} 
else { 
    $pid = $$; 
}

# Do something useful - put our PID into the pid_file
if( 0 != $pid ) {
    open( LOCK_FILE, ">$pid_file" );
    print LOCK_FILE "$pid\n";
    close( LOCK_FILE );
    if( !$foreground ) { 
        exit( 0 ) 
    };
}

daemon_log(" ", 1);
daemon_log("$0 started!", 1);

# delete old DBsqlite lock files
system('rm -f /tmp/gosa_si_lock*gosa-si-client*');


# complete client_address
$client_address = $client_ip.":".$client_port;


# detect own ip and mac address
my $network_interface= &get_interface_for_ip($client_ip);
$client_mac_address= &get_mac($network_interface);
daemon_log("gosa-si-client ip address detected: $client_ip", 1);
daemon_log("gosa-si-client mac address detected: $client_mac_address", 1);


# import events
&import_events();
#eval($event_hash->{'print_hello'}."::print_hello");


# create socket for incoming xml messages
POE::Component::Server::TCP->new(
    Alias => 'gosa-si-client',
	Port => $client_port,
	ClientInput => \&server_input,
);
daemon_log("start socket for incoming xml messages at port '$client_port' ", 1);


# prepare variables
if (defined $server_ip && defined $server_port) {
    $server_address = $server_ip.":".$server_port;
}
$xml = new XML::Simple();
$default_server_key = $server_key;


# find all possible gosa-si-servers in DNS
if (defined $server_domain) {
    my @tmp_servers = &get_server_addresses($server_domain);
    foreach my $server (@tmp_servers) { 
        unshift(@servers, $server); 
    }
}
# add gosa-si-server address from config file at first position of server list
if (defined $server_address) {
    unshift(@servers, $server_address);
}
my $servers_string = join(", ", @servers);
daemon_log("found servers in configuration file and via DNS: $servers_string", 5);


POE::Session->create(
	inline_states => {
		_start => \&register_at_gosa_si_server ,
	}
);

POE::Kernel->run();
exit;