#!/bin/perl

package PerlSvc;

use strict;
#no strict 'refs';
use Net::IP::AddrRanges;
use Sys::HostAddr;

my $VPNStoppCmdLine="";
my $service = 'VPNConnect';
my $configfile = 'c:\VPNConnect\VPNConnect.conf';
my $delay = 30;
my @CONF;
my $LOG;

my @options = ('config=s' => \$configfile );

# turn on autoflush
$|=1;

(my $progname = $0) =~ s/.*?([^\\]+?)(\.\w+)$/$1/;
our(%Config,$Verbose);

#open FH, "<$configfile";
#@CONF=<FH>;
#close FH;
#Main();

sub get_options {
    require Getopt::Long;
    my @options = @_;
    my $usage = pop @options;
    $SIG{__WARN__} = sub { print "$usage\n$_[0]"; exit 1 };
    Getopt::Long::GetOptions(@options);
    $SIG{__WARN__} = 'DEFAULT';
}
sub configure {
    %Config = (ServiceName => "$service",
	       DisplayName => "$service",
	       Parameters  => "--config $configfile",
	       Description => "Automatically connect to given VPN Gateway");
}
sub Startup {
    get_options(@options, <<__USAGE__);
Try `$progname --help` to get a list of valid options.
__USAGE__

    #Log("\n$Config{DisplayName} starting at: ".localtime);
    open FH, "<$configfile";
    @CONF=<FH>;
    close FH;
    while (ContinueRun($delay)) {
	Main();
    }
    DLog("$service and connection stopped");
    ServiceStopp();
    #Log("$Config{DisplayName} stopped at: ".localtime);
}
sub Install {
    #get_options('name=s' => \$service, @options, <<__USAGE__);
    get_options(@options, <<__INSTALL__);
Valid --install suboptions are:

  auto       automatically start service
  --config   config file name                 [$configfile]

For example:

  $progname --install auto --config configfile

__INSTALL__

    configure();
}
sub Help {
    print <<__HELP__;

Automatically connects to VPN Gateway given in configfile

Install it as a service:

    $progname --install auto --config configfile
    net start $service

You can pause and resume the service with:

    net pause $service
    net continue $service

To remove the service from your system, stop und uninstall it:

    net stop $service
    $progname --remove

configfile defaults to c:\\VPNConnect\\VPNConnect.conf
__HELP__

    # Don't display standard PerlSvc help text
    $Verbose = 0;
}
sub Pause {
    #Log("$Config{ServiceName} is about to pause at ".localtime);
}
sub Continue {
    #Log("$Config{ServiceName} is continuing at ".localtime);
}
sub Remove {
	get_options('service=s' => \$service, <<__REMOVE__);
No valid --remove suboptions

For example:

  $progname --remove
__REMOVE__
    $Config{ServiceName} = "$service";
    $Config{DisplayName} = "$service";
}
sub Main {
    my @LocalSubnets;
    my $LogPath;
	my $VPNClientPath;
    my $VPNProfile;
    my $VPNXauthUser;
    my $VPNXauthPassword;
    my $VPNStatusCmdLine;
    my $VPNStatus;
    my $VPNStatusString;
    my $VPNStartCmdLine;
    
    foreach my $line (@CONF) {
        chomp $line;
        next if ($line =~ /^#/);
        my($k,$v) = split (/=/,$line);
	if ($k eq "LocalSubnet") { push @LocalSubnets,$v; }
	if ($k eq "LogPath") { $LogPath = $v; }
	if ($k eq "VPNClientPath") { $VPNClientPath = $v; }
	if ($k eq "VPNProfile") { $VPNProfile = $v; }
	if ($k eq "VPNXauthUser") { $VPNXauthUser = $v; }
	if ($k eq "VPNXauthPassword") { $VPNXauthPassword = $v; }
	if ($k eq "VPNStatusCmdLine") { $VPNStatusCmdLine = $v; }
	if ($k eq "VPNStatus") { $VPNStatus = $v; }
	if ($k eq "VPNStatusString") { $VPNStatusString = $v; }
	if ($k eq "VPNStartCmdLine") { $VPNStartCmdLine = $v; }
	if ($k eq "VPNStoppCmdLine") { $VPNStoppCmdLine = $v; }
    }
    $LOG=$LogPath;
    # Variablen in Commandlinestrings ersetzen
    my @Vars = qw /VPNProfile VPNXauthUser VPNXauthPassword/;

    foreach my $v (@Vars) {
	my $a;
	$a=$VPNProfile       if ($v eq "VPNProfile");
	$a=$VPNXauthUser     if ($v eq "VPNXauthUser");
	$a=$VPNXauthPassword if ($v eq "VPNXauthPassword");
		
	$VPNStatusCmdLine =~ s/\$$v/$a/;
	$VPNStartCmdLine  =~ s/\$$v/$a/;
	$VPNStoppCmdLine  =~ s/\$$v/$a/;
    }
    # lokale adresse ermitteln
    my $sysaddr = Sys::HostAddr->new();
    my $ip;
    my $noiperr=eval {
	$ip = $sysaddr->main_ip('route');
	};
    if ($noiperr) {
	# in einem netz in LocalSubnets?
	my $ranges = Net::IP::AddrRanges->new();
	$ranges->add(@LocalSubnets);
	if (!$ranges->find($ip)) {
	    # nein
	    # vpn status abfragen
		    chdir($VPNClientPath);
		    my @ret=`$VPNStatusCmdLine`;
	    # Statusmeldung durchlaufen
	    my $found=0;
	    foreach (@ret) {
		# und nach Suchstring suchen
		if ($_ =~ /$VPNStatusString/) {
		    # gefunden!
		    $found=1;
		}
	    }
	    # Suchstring gefunden?
	    my $connected;
	    if ($found == 1) {
		# ja
		$connected = 1 if ($VPNStatus == 1); # Suchstring zeigt aufgebaute Verbindung an
		$connected = 0 if ($VPNStatus == 0); # Suchstring zeigt abgebaute Verbindung an
		if (!$connected) {
			    # verbindung nicht hergestellt, aufbauen!
			    DLog("Connection start");
			    `$VPNStartCmdLine`;
		}
		else {
			    # verbunden!
		}
	    }
	}
	else {
	    DLog("In range, no connection will be built");
	}
    }
    else {
	DLog ("No IP found");
    }
}
sub ServiceStopp {
    `$VPNStoppCmdLine`;
}
sub DLog {
    my $path="$LOG"."vpnconnect.debug.log";
    open FH, ">>$path";
    print FH "$_[0]\n";
    close FH;
}