#!/usr/bin/perl -w
use Net::DNS;

sub getRRVal($) {
    my $rr = shift;
    my $retVal = '';
    if ($rr->type eq 'A' or $rr->type eq 'AAAA') {
	$retVal = $rr->address;
    } elsif ($rr->type eq 'CNAME') {
	$retVal = $rr->cname;
    } elsif ($rr->type eq 'NS') {
	$retVal = $rr->nsdname;
    } elsif ($rr->type eq 'MX') {
	$retVal = $rr->exchange; # preference
    } elsif ($rr->type eq 'TXT') {
	$retVal = $rr->txtdata;
    }
    return $retVal;
}

my $resNS  = Net::DNS::Resolver->new;
$resNS->nameservers("ns.fjfi.cvut.cz");
my $resBR  = Net::DNS::Resolver->new;
$resBR->nameservers("beta.fjfi.cvut.cz");

my @zone = $resNS->axfr("fjfi.cvut.cz");

foreach $rr (@zone) {
    my $name = $rr->name;
    my $type = $rr->type;
    my $pkNS = $resNS->query($name, $type);
    my $pkBR = $resBR->query($name, $type);
    if (defined($pkNS) and defined($pkBR)) {
	# both defined
	my @rrNS = $pkNS->answer;
	my @rrBR = $pkBR->answer;
	foreach my $rrNS (@rrNS) {
	    my $valNS = getRRVal($rrNS);
	    if ($valNS ne '') {
		print "DEBUG: valNS - " . $valNS . "\n";
		my $ok = 0;
		foreach my $rrBR (@rrBR) {
		    my $valBR = getRRVal($rrBR);
		    print "DEBUG: valBR - " . $valBR . ($valBR eq $valNS) . "\n";
		    if ($valBR ne '' and $valBR eq $valNS) {
			$ok = 1;
		    }
		}
		print "ERROR: $name ($type) different: $valNS is not in BR\n" if $ok == 0;
	    }
	}
	foreach my $rrNS (@rrBR) {
	    my $valNS = getRRVal($rrNS);
	    if ($valNS ne '') {
		print "DEBUG: valNS - " . $valNS . "\n";
		my $ok = 0;
		foreach my $rrBR (@rrNS) {
		    my $valBR = getRRVal($rrBR);
		    print "DEBUG: valBR - " . $valBR . ($valBR eq $valNS) . "\n";
		    if ($valBR ne '' and $valBR eq $valNS) {
			$ok = 1;
		    }
		}
		print "ERROR: $name ($type) different: $valNS is not in NS\n" if $ok == 0;
	    }
	}
    } elsif (defined($pkNS) or defined($pkBR)) {
	# one undef...
	print "ERROR: $name ($type) defined only in ";
	print "NS" if defined($pkNS);
	print "BR" if defined($pkBR);
	print "\n";
    } else {
	# both undef?
	print "ERROR: check error for $name (both undef?)\n";
    }
}