#!/usr/bin/perl -w
# i (df) wrote this mainly to make sure that the deepdns IPs are configured correctly
# but since it also tells you how long it took to receive a response maybe someone
# would want to use this to see which DNS server would be fastest for them
$|++;
use strict;
use IO::Socket;

# Debian: apt-get install libtime-hires-perl
# RHEL:   yum install perl-Time-HiRes
use Time::HiRes qw( gettimeofday tv_interval);

# Debian: apt-get install libnet-dns-perl
# RHEL:   yum install perl-Net-DNS
use Net::DNS;

# Should already be included in your Perl installation
use Term::ANSIColor qw(:constants);

my (@god, @dammit);
print "Getting DeepDNS IPs...\n";
my @ddns_ips = gethostbyname("public.deepdns.net") or die "Can't resolve public.deepdns.net: $!\n";
@ddns_ips = map { inet_ntoa($_) } @ddns_ips[4 .. $#ddns_ips];
print "Checking regular DNS resolution...\n";
for (@ddns_ips) {
 &check($_,"whoami.cryptostorm.is");
}
print "Checking .onion resolution...\n";
for (@ddns_ips) {
 &check($_,"stormwayszuh4juycoy4kwoww5gvcu2c4tdtpkup667pdwe4qenzwayd.onion");
}
print "Checking .i2p resolution...\n";
for (@ddns_ips) {
 &check($_,"stats.i2p");
}

sub check {
 our $ip = $_[0];
 our $host = $_[1];
 our $message;
 sub timeout {
  print "$ip " . BLINK BOLD RED "timed out when resolving", RESET . " $host\n";
  close($message);
 }
 eval {
  local $SIG{ALRM} = sub { &timeout; };
  alarm 10;
  my $now = [gettimeofday()];
  my ($datagram,$flags);
  my $data = &lookup("$host",$ip);
  if (defined($data)) {
   if ($data =~ /^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/) {
    my $andagain = tv_interval($now)*1000;
    my $ms = sprintf("%d", $andagain);
    # comment out the below line to only show broken things
    print "$ip " . BOLD GREEN "correctly resolved $host", RESET . " and responded in $ms ms\n";
    if ($ms =~ /^[0-9]{3}$/) {
     $ms =~ s/^/0/;
    }
    if ($ms =~ /^[0-9]{2}$/) {
     $ms =~ s/^/00/;
    }
    if ($ms =~ /^[0-9]{1}$/) {
     $ms =~ s/^/000/;
    }
    push(@god,"$ms:$ip");
   }
  }
  alarm 0;
 }
}

sub lookup {
 my ( $hostname, $server ) = @_;
 my $res = new Net::DNS::Resolver;
 $res->nameservers($server);
 my $packet = $res->query($hostname);
 if ( !$packet ) {
  warn "$server responded, " . BLINK BOLD RED "but didn't return any data for $hostname", RESET . "\n";
  return;
 }
 my (@results);
 foreach my $rr ( $packet->answer ) {
  push ( @results, $rr->address );
 }
 return join( ', ', sort @results );
}