$title

#!/usr/bin/perl # # nlog dns wrapper # ## require "nlog-config.ph"; umask($umask); my $results; my $ipaddr; printheader("n-log nameserver query results"); print <

Nameserver Query Results

HEADER ; # Filter out shell escapes and such from the query string $ipaddr = $ENV{'QUERY_STRING'}; $results = resolveip($ipaddr); $results =~ s/\/>\;/g; $results =~ s/\n/
/g; print "

\n$results\n";

print "\n";

sub printheader {

($title) = @_;

print <



$title



THEHEADER
;

}

sub resolveip {
    my $results;
    my ($ip) = @_;
    my $binip = gethostbyname($ip);
    my $oip, $nip;
    
    my ($hostname) = gethostbyaddr($binip,AF_INET);
    if ($hostname && $binip && length($binip) == 4) {
        my $newip = gethostbyname($hostname);
        my ($newhost) = gethostbyaddr($newip,AF_INET);
        
        if ($newip ne $binip || $hostname ne $newhost) {
            $results .= "The re-resolved ip addresses do not match:\n";
            if (length($newip) != 4) 
            {
               $results .= "gethostbyname() returned NULL for $hostname (" . inet_ntoa($binip)  . ").\n";   
            } else {
               $results .= inet_ntoa($binip)  . " ($hostname) is not " . inet_ntoa($newip) . " ($newhost)\n";
            }
        } else {
            $results .= "The address $ip resolved to $hostname (" . inet_ntoa($binip) . ")\n";
        }
    } else {
        if ($binip) {
            $results .= "That address (" . inet_ntoa($binip) . ") has no hostname associated with it.\n";
        } else {
            $results .="That address does not exist.\n";
        }
    }
    return $results;
}

exit 0;