Function writeIPv6

test/common/dns.js:167–182

(ip)

}

function writeIPv6(ip) {
  const parts = ip.replace(/^:|:$/g, '').split(':');
  const buf = Buffer.alloc(16);

  let offset = 0;
  for (const part of parts) {
    if (part === '') {
      offset += 16 - 2 * (parts.length - 1);
    } else {
      buf.writeUInt16BE(parseInt(part, 16), offset);
      offset += 2;
    }
  }

  return buf;
}

function writeDomainName(domain) {
  return Buffer.concat(domain.split('.').map((label) => {