#!/usr/bin/perl
#
# extremely basic sniffer with Net::Pcap - Tikiman
#


use Net::Pcap;

$err = '';

$device = Net::Pcap::lookupdev(\$err);
$cap_descrip = Net::Pcap::open_live($device,2000,0,1000,\$err);
Net::Pcap::loop($cap_descrip, 100, \&read_func , "test" );


sub read_func {
	my($data, $header, $packet) = @_;	
#	while(($key,$val) = each %$header) {
#	    print "$key - $val\n";
#	}

	($smac,$tmac,$type) = unpack('H12 H12 H4',$packet);
	
	if ($type == "0806") {
	    print "ARP packet: Source - $smac | Target - $tmac\n";
	} elsif ($type == "0800") {
	    $packet = substr($packet,14,9999);
	    ($verihl,$tos,$len,
	     $id, $flags,
	     $ttl, $proto, $checksum,
	     $sourceip,
	     $destip) = unpack('H2 B8 n 
                                 n n 
                                 C C H4 
                                 A4 A4',$packet);
	    $data = substr($packet,40,999);

	    print "IP Protocol - $proto\n";
	    print "Source IP - " . join('.',unpack('C4',$sourceip)) . "\n";
	    print "Dest IP - " . join('.',unpack('C4',$destip)) . "\n";
	    print "Data - $data\n";
	}

#	binDebug($packet);
#	hexDebug($packet);

}





sub binDebug {
    my $data = shift;
    my $counter = 1;
    print "Binary Octet Dump:\n";
    for (my $i = 0;$i < length($data);$i += 4) {
	print "$counter: " . 
	    join(' ',unpack('B8 B8 B8 B8',substr($data,$i,4))) . "\n";
	$counter++;
    }
}



sub hexDebug {
    my $data = shift;
    my $counter = 1;
    print "Hex Dump:\n";
    for (my $i = 0;$i < length($data);$i += 4) {
	print "$counter: " . 
	    join(' ',unpack('H2 H2 H2 H2',substr($data,$i,4))) . "\n";
	$counter++;
    }
}