#!/usr/bin/perl
#
# nshunter.pl
#
# Suche den schnellsten DNS-Server vor Ort
#

use strict;
use warnings;

my $tmp_file         = './tmp.txt';
my $dns_list_file    = './dns.txt';
my $quick_test_file  = './quick.txt';

my $test_clock       = 0.15;

my ( $handle, $list, $hash, $ax, $i, $j );

sub delay {
    select( undef, undef, undef, shift );
}

print "\nDNS-SERVERLISTE ONLINE AKTUALISIEREN...\n";

system( qq[wget -nv https://www.ungefiltert-surfen.de/nameserver/ch.txt -O $tmp_file] );
system( qq[cat $tmp_file > $dns_list_file] );
system( qq[echo >> $dns_list_file] );
system( qq[wget -nv https://www.ungefiltert-surfen.de/nameserver/de.txt -O $tmp_file] );
system( qq[cat $tmp_file >> $dns_list_file] );
system( qq[echo >> $dns_list_file] );
system( qq[wget -nv https://www.ungefiltert-surfen.de/nameserver/at.txt -O $tmp_file] );
system( qq[cat $tmp_file >> $dns_list_file] );
system( qq[echo >> $dns_list_file] );
system( qq[rm -f $tmp_file] );

open ( $ax, "<", $dns_list_file );
@$list = <$ax>;
close ( $ax );
chomp ( @$list );

# IPv6 kicken
@$list = grep( /.*\..*/, @$list );

# doppelte IP's kicken
%$hash = map { $_, [] } @$list;
@$list = keys( %$hash );

#######
# QUICKTEST FOR ALL SERVERS
###########################

$i = $#$list + 1;
$j = 1;

print "QUICKTEST BEI $i DNS-SERVERN DURCHFÜHREN...\n";

system ( qq[rm -f $quick_test_file] );

for ( @$list ){
    print "Teste DNS-Server $j von $i: $_\n";
    system( qq[./nsquick.pl $_ www.google.com >> $quick_test_file &] );

    $j++;

    last if $j>30; # test
    delay( $test_clock );
}

do {
    delay( $test_clock * 2 );
    my $ax = qx[ps ax | grep nsquick.pl | grep -v grep];
    $list = [ split( /\n/, $ax ) ];
    $i = $#$list + 1;
    print "Warte auf $i DNS-Server...\n";
} while ( $i );

#!/usr/bin/perl
#
# nsquick.pl:
#
# DNS-Server-Schnelltest
#

use strict;
use warnings;
use Data::Dump qw /dump/;

my $dns  = shift @ARGV;
my $dom  = shift @ARGV;
my $out;

sub dig {
    my $dns     = shift;
    my $query   = shift;
    my $timeout = shift;
    my $tries   = shift;

    my $status = 'ERROR';
    my $qtime  = '---';

    my $in     = qx[dig \@$dns $query +time=$timeout +tries=$tries];

    my @list = split( /\n/, $in );

    for ( @list ) {
        $status = 'NOCONN' if $_ =~ /;; connection timed out;/;
        $status = $1       if $_ =~ /.*status: (.*), .*/;
        $qtime  = $1       if $_ =~ /^;; Query time: (.*) msec.*/;
    }

    return "$dns;;$status;;$qtime";
}

push @$out, dig( $dns, $dom, 4, 1 );
push @$out, dig( $dns, $dom, 4, 1 );

print "$_\n" for @answers;