sub valid_dotted_quad {
        my $all_valid = 1;
        my @sections;

ARGUMENT:for (@_) {
                next ARGUMENT unless $all_valid;
                next ARGUMENT unless ($all_valid &&= /^\d{1,3}\.\d{1,3}\.\d{1,3}
\.\d{1,3}$/o);
                @sections = split /\./, $_;
                for (@sections) {
                        next ARGUMENT unless ($all_valid &&= ($_ <= 0xFF));
                }
        }

        return $all_valid;
}